Continuous method for preparing silicone dioxide and silicone dioxide product prepared by this method

FIELD: medicine, pharmaceutics.

SUBSTANCE: invention refers to the chemical-pharmaceutical industry and represents a composition of oral care agents involving silicone dioxide particles in an amount of 5 to 50 wt % of the composition weight, wherein the silicone dioxide particles have an oil absorption value to 100 cm3/100 g, a sphericity coefficient (S80) of more than 0.9 and the Brass-Einlener abrasive wear of less than 8.0 mg loss/100,000 revolutions, wherein at least 80% particles of silicone dioxide are shaped from rounded to round.

EFFECT: improving the composition.

13 cl, 6 ex, 13 dwg, 10 tbl

 

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority filing date of February 24, 2010, patent application US 12/711321, the disclosure of which is incorporated by reference in their entirety in this document.

PRIOR art

Precipitated silica can be obtained by adding acidifying agent to the alkali metal silicate deposition of amorphous silicon dioxide. The sediment is usually filtered from the reaction mixture and then washed and dried. Typically, the dried silica is then mechanically pulverized to obtain an acceptable particle size and particle size distribution. On an industrial scale silicon dioxide can be obtained during step a periodic process, including the above-mentioned stage. The equipment required for this process may require a significant capital investment, which often leads to inefficiency of the process, particularly when there is downtime, in which the reagents are not used. However, there are other ways of obtaining silicon dioxide, most of which are difficult to control and zoom, and many, in addition, require large-scale processing stages after receipt of the silicon dioxide

Thus, there is a need for an improved method of producing silicon dioxide, which would have eliminated the above-mentioned disadvantages of the traditional methods for producing silicon dioxide. This and other needs are satisfied by the present invention.

The INVENTION

In this work revealed a continuous method of obtaining a product of silicon dioxide, comprising: (a) a continuous supply of acidifying agent and a silicate of an alkali metal in a loop reaction zone containing a flow of a liquid medium, where at least part of the acidifying agent and a silicate of an alkali metal reacts with the formation of the product of silicon dioxide in a liquid medium loop reaction zone; (b) continuous recirculation of the liquid through the loop reaction zone; and (C) continuous discharging of the loop reaction zone parts of a liquid medium containing the product of silicon dioxide.

Also disclosed particles of silicon dioxide having a coefficient of absorption of up to 100 cm3/100 g, where at least 80% of particles of silicon dioxide have the shape from rounded to rounded, and where particles of silicon dioxide have a coefficient of sphericity (S80) higher than 0.9 and the amount of abrasive wear on the brass-Airliner less than 8.0 mg loss/100,000 revolutions.

Also disclosed particles of silicon dioxide having a particle size of from 3 to mm, the coefficient of absorption above 100 cm3/100 g and the degree of plaque removal (PCR) at 20% load of silicon dioxide of at least 85.

In addition, the disclosed compositions funds for the care of teeth, comprising particles of silicon dioxide in an amount of 5 to 50% by weight of the composition, where particles of silicon dioxide have a coefficient of absorption of up to 10 cm3/100 g, the coefficient of sphericity (S80) higher than 0.9 and the amount of abrasive wear on the brass-Airliner less than 8.0 mg loss/100,000 revolutions; where at least 80% of particles of silicon dioxide have the shape from rounded to rounded.

Also disclosed are compositions of funds for the care of teeth, comprising particles of silicon dioxide in an amount of 5 to 50% by weight of the composition; where the particles of silica have a particle size of from 3 to 15 μm, coefficient of absorption above 100 cm3/100 g and the degree of plaque removal (PCR) at 20% load of silicon dioxide of at least 85.

Advantages of the invention will be partially described in the following section, descriptions, and will partly be obvious from the description or may be learned through practical application of the aspects described below. The advantages, described below, will be realized and attained by means of the elements and combinations which are particularly marked in the attached claims. It should be understood that islogin the e above General description, and following detailed description are provided solely for illustrative and explanatory purposes and are not restrictive.

A BRIEF DESCRIPTION of GRAPHIC MATERIALS

Fig. 1 is an example schematic of a continuous loop reactor.

Fig. 2 is a graph showing scans Horiba particle size for Example 2ND suspension (circles), after spray drying (diamonds) and crushed with a hammer (triangles). For comparison, silicon Dioxide ZEODENT 103 (squares).

Fig. 3A and 3B represent microsemi performed using a scanning electron microscope (SEM), Example 2D, obtained using the disclosed method.

Fig. 4A and 4B are SEM images of Example 2R, obtained using the disclosed method.

Fig. 5A and 5B are SEM images of Example 2E, obtained using the disclosed method.

Fig. 6A and 6B are SEM images for ZEODENT 113 and ZEODENT

165.

Fig. 7 is a SEM picture of Example 2F, obtained using the disclosed method.

Fig. 8 is a graphical depiction coolness of particles.

Fig. 9 is a graphical representation of the calculation of the coefficient of coolness.

DETAILED description of the INVENTION

Before the present compounds, compositions, composite m is materials, products, devices and/or methods are disclosed and described, it should be understood that the aspects described below are not limited to specific compounds, compositions, composite materials, products, devices, processes, or applications, such as, and, of course, may vary. It should also be understood that the terminology used in this context is intended to describe particular aspects and should not be restrictive.

In this description and the claims will be made reference to a number of terms have the following meanings:

In the scope of this description, unless the context requires otherwise, the words "include" or options such as "comprises" or "comprising", will imply the inclusion of a specified unit or stage, or group of units or stages, but not the exclusion of any other unit or stage, or group of units or stages.

It should be noted that as used in this description and the attached claims, the singular forms of "a," "an" and "the" include many objects, if the context requires otherwise. So, for example, reference to "acidifying agent" takes into account a mixture of two or more such agents, and so forth.

"Optional" or "optionally" means that the subsequently described event or circumstance could the t to happen or not to happen, and that the description covers the case where the event or circumstance occurs and instances in which it occurs.

The ranges in this context can be expressed as "about" one particular value and/or to "about" another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, if the quantities are expressed as an approximate value by use of the antecedent "about", it should be understood that the private value forms another aspect. You should also understand that the final value of each of the ranges are significant both in relation to the other end values, and independently from the other end values.

Disclosed are compounds, compositions, and components that can be used for, can be used in conjunction with, can be used in the preparation of either are products of the disclosed methods and compositions. These and other materials are disclosed herein, it is understood that when combinations, subsets, interactions, groups, and so forth of such materials are disclosed that while specific reference of each various individual and aggregate combinations, and the conversion of these soy is ineni may not be fully disclosed, each of them is considered particularly described in this paper. For example, if you disclose and discuss a number of different acidifying agents and alkali metal silicates, considering in particular without exception, all the combination and transformation of acidifying agent and silicate metal, if certain way otherwise indicated. So, if disclosed class of agents a, b and C, as well as class agents D, E and F, and is disclosed as an example of the combination of agents A-D, then even if each is not listed individually, each is considered individually and in the aggregate. So, in this example, each of the combinations a-E, A-F, B-D, b-E, B-F, C-D, C-E and C-F are considered in particular and should be considered disclosed from disclosure of a, b and C; D, E and F; and combinations of example A-D. likewise, any subset or combination of this is also seen in the particular and disclosed. For example, the subgroup a-E, B-F and C-E in particular is considered and should be considered disclosed from disclosure of a, b and C; D, E and F; and combinations of example A-D. This concept applies to all aspects of this disclosure, including, but not limited to list, stage of the method of obtaining and using the disclosed compositions. So, if there are some extra steps that can be performed, it is understood that each of these extra steps which may be performed with any particular embodiment or combination of embodiments disclosed methods, and that each such combination is seen in particular and should be considered disclosed.

A method of obtaining a product of silicon dioxide

According to one aspect, the method of the invention is a continuous process, in which the acidifying agent and a silicate of an alkali metal served continuously in a loop reaction zone containing a flow of a liquid medium; where at least part of the acidifying agent and a silicate of an alkali metal reacts with the formation of the product of silicon dioxide in a liquid medium loop reaction zone. As acidifying agent and a silicate of an alkali metal served continuously in a loop reaction zone, the contents of the loop reaction zone (i.e., fluid) continuously recycle. Product of silicon dioxide is collected, unloading portion of the liquid medium containing the product of silicon dioxide, which, according to one aspect, an equivalent volume of raw materials that are added to the loop reaction zone.

In this context "loop reaction zone" refers to the area inside the reactor, forming a closed loop containing recirculating liquid medium, where the acidifying agent and a silicate of an alkali metal reacts with the formation of the product of silicon dioxide. As will be discussed below, according to one aspect, the hinge Rea the operating area defined by the walls of the continuous path, formed by one or more of the pipe loop reactor. Generally speaking, the liquid medium in a loop reaction zone will vary in composition depending on the stage of the process. Before adding acidifying agent and a silicate of an alkali metal in a liquid medium can contain only water or a suitable aqueous solution or dispersion (suspension). According to one aspect, prior to submitting the acidifying agent and a silicate of an alkali metal in the reaction zone, the liquid medium may contain crystals-crystal seed of silicon dioxide, are used to reduce gelation in a loop reaction zone and contributing to the formation of product of silicon dioxide. In accordance with the private aspect, before adding acidifying agent and a silicate of an alkali metal, if necessary, in a loop reaction zone can first be added and recycled precipitated silicon dioxide, sodium sulfate, sodium silicate and water, and then can be added acidifying agent and a silicate of an alkali metal. As you add to the loop reaction zone acidifying agent and a silicate of an alkali metal in a liquid reaction medium leads to the formation of product of silicon dioxide. Product of silicon dioxide in most cases will be besieged by the product and, therefore, will be dis is ersey phase in the liquid reaction medium. According to one aspect, before collecting the desired product of silicon dioxide crystals-the seed product of silicon dioxide can be removed from the loop reaction zone.

The temperature and pressure of the process can also vary within a wide range depending on the type of the desired product of silicon dioxide. According to one aspect of the method, in the liquid environment keep the temperature from about room temperature up to 130°C. Similarly, can be used with a wide range of pressures. The pressure may vary from atmospheric pressure to elevated pressure. For example, when used in accordance with the method of continuous loop reactor, the reactor may be equipped with a back pressure valve for regulating the pressure inside the reactor in a wide range.

The alkali metal silicate and acidifying agent can be fed into the reaction zone at different speeds. The speed of addition of the alkali metal silicate should normally be such that in the reaction zone was maintained the required concentration of silicate, whereas the speed of adding acidifying agent should be such that in a loop reaction zone maintained the required pH value. According to one aspect, the alkali metal silicate is served in a loop reaction zone with speed on ENISA least 0.5 l/min The maximum speed of addition of the alkali metal silicate may vary within a wide range depending on the volume of the loop reaction zone and the scale of the method of producing silicon dioxide. High speed of addition of the silicate will be required, for example, in the case of very large-scale process, which uses large volumes of reagents. According to one of specific examples, the alkali metal silicate is served with a speed of from 0.5 to 5 l/min, or from 0.5 to 3 l/min

Acidifying agent is usually served in a loop reaction zone at a rate sufficient to maintain a liquid medium pH in the range from 2.5 to 10.5. According to other aspects, the acidifying agent is served in a loop reaction zone at a rate sufficient to maintain a liquid medium pH values ranging from 7.0 to 10, or from 7.0 to 8.5. For example, in accordance with the private aspect, in a liquid medium support pH of about 7.5. The pH of a liquid medium can be controlled with any standard pH electrode. According to some examples, the pH of a liquid medium can be evaluated by direct measurement of the pH of a liquid medium (suspension). In accordance with these examples, the pH of the liquid reaction medium will in most cases vary in the range from 2.5 to 10.5, from 6 to 10 or ot to 8.5.

Liquid medium can be recycled with different speeds depending on conditions in a loop reaction zone, such as the degree of mixing or shear in the reaction zone, and depending on the scale of the production process. In most cases, the fluid recirculates through the loop reaction zone with a speed of at least 15 l/min In accordance with a specific example of a liquid medium may be recycled through the loop reaction zone with a speed of from 15 to 100 l/min, from 30 to 80 l/min, or from 70 to 80 l/min

Can be used a number of acidifying agents, including acids and other agents capable of reacting with the silicate of an alkali metal with the formation of the product of silicon dioxide. Acid or acidifying agent may be a Lewis acid or acid Bronsted, such as a strong mineral acid, e.g. sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid and others. Such acids may be added to the reaction zone in the form of dilute solutions. As an example, in a loop reaction zone as the acidifying agent may be supplied to the sulfuric acid solution with a concentration of from 6 to 35 wt.% and, more preferably, from 10 to 17 wt.%. In accordance with other aspects, as acidifying agent gas may be used, such kaxa 2. Carbon dioxide forms a weak acid (carbonic acid) and, consequently, a weak acid, it may be desirable to maintain in a liquid medium pH above about 8.5.

According to another aspect, the acidifying agent may be selected based on the type of the desired product of silicon dioxide. For example, as the acidifying agent can be used acidic solution of aluminum sulfate, and the resulting product of silicon dioxide is, therefore, a silicate of an alkali metal. As a particular example, aluminum sulfate may be added to sulfuric acid, and the resulting mixture may be used as the acidifying agent.

In accordance with the method of the invention can be used with any suitable alkali metal silicate, including silicates, disilicate metals and the like. Water-soluble potassium silicates and sodium silicates are particularly preferred. Generally, acceptable products of silicon dioxide of the present invention can be obtained using silicates having different molar ratios of alkali metal silicate. In the case of sodium silicate, for example, the molar ratio of NaO2:SiO2will generally vary from 1:1 to 1:3.5, and preferably from about 1:2.4 to :3,4. The silicate of an alkali metal, supplied in a loop reaction zone, preferably served in aqueous solution, similar acidifying agent. A solution of silicate of alkali metal, supplied in a loop reaction zone, as a rule, can contain from about 8 to 35% and, more preferably, from about 8% to 20 wt.% the alkali metal silicate by weight of the total solution of silicate of alkali metal, supplied in a loop reaction zone.

If necessary, as well as to reduce the concentration of alkali metal silicate or acidifying agent in the initial solution before applying the solution to the loop reaction zone it can be added to dilution water and/or dilution water may be added separately in a loop reaction zone and thereafter mixed with the silicate of an alkali metal and/or acidifying agent and any other content of a liquid medium.

As the required amount of acidifying agent and a silicate of an alkali metal is added in a loop reaction zone, the liquid medium will usually be recycled, passing through the zone of recirculation on average at least three times. The number of times that the average fluid recirculates through the loop reaction zone, referred to in this context as "the average number of passes" that Russ is icyhot in accordance with the following equations. The residence time of the product of silicon dioxide in the recirculating loop before discharge is determined by dividing the volume of the reaction system at the speed of adding raw material (the speed of adding alkali metal silicate + the speed of adding acidifying agent). The number of passes/minute can be further calculated by dividing the speed of recycling on the total system. After that, the residence time can be multiplied by the number of passes/minute to obtain the average number of passes.

InpemIstay (min.)=system capacity (l)the total rate of addition of raw materials(l/min)

Knumber of passes/min=the rate of recirculation (l/min)system capacity (l)

InpemIstay (min.)=xthe number of passes(min)=with apedneehandwith alaboutppaboutxaboutd aboutin

Product of silicon dioxide can be recycled so that the average number of passes will be from 3 to 200, or from 10 to 200. In most cases, more than the average number of passes, the more spherical and rounded the result is a product of silicon dioxide. The number of passes in recycling (average number of passes) can, thus, be selected based on the type of the desired product of silicon dioxide.

Product of silicon dioxide can be discharged from the loop reaction zone through different mechanisms. According to one aspect, in the method, as discussed above, use of a continuous loop reactor containing a valve for product recovery of silica from the loop reaction zone. However, it is preferable that the product of silicon dioxide displaced from the loop reaction zone by adding additional fluid into the reaction zone so that a portion of the liquid medium containing the product of silicon dioxide, is discharged from the reaction zone (i.e., overflow occurs the reaction zone). This can be accomplished, according to one aspect, by continuous addition of acidifying agent and/or silicate of an alkali metal in a loop reaction zone as a portion of the liquid medium volumetric the ski is replaced by the volume added acidifying agent and/or silicate of an alkali metal.

In accordance with some aspects of the method, acidifying agent and a silicate of an alkali metal added continuously as the liquid reaction medium and recycle as unload product of silicon dioxide. Thus, according to one aspect, each of the stages of method proceeds continuously and simultaneously. According to another aspect of acidifying agent and a silicate of an alkali metal, each served in a loop reaction zone simultaneously. Acidifying agent and a silicate of an alkali metal is preferably added to the loop response at various points throughout the length of the loop reaction zone. For example, the alkali metal silicate may be added in the loop above acidifying agent, so that when the acidifying agent is fed into the reaction zone, the alkali metal silicate is already present there.

Modification of product structure silicon dioxide can be achieved by changing the temperature, ionic strength, speed adding and energy consumption. As a rule, changes temperature, speed, recirculation and velocities adding acidifying agent/silicate of alkaline metal lead to the greatest changes in the physical characteristics of the products of silicon dioxide. Generally speaking, the more liquid recycle, the greater the residence time of the product dio the sid of silicon in the recirculation loop (less than the speed of the addition), and the higher the temperature, the lower structure (as defined by oil absorption) of the resulting product of silicon dioxide. It was found that changes of pH in a liquid medium to minimize the formation of deposits of silicon dioxide (fouling) inside the loop reaction zone when used pH is less than approximately 9,0.

Product of silicon dioxide can accumulate after discharge from the loop reaction zone in a suitable collection and processed on demand. According to some aspects, the product of the silicon dioxide does not require additional processing (except washing to remove salts, and the like) and can be transported in the form of a wet sludge or, if necessary, can be dried. According to one aspect, for example, the resulting product of silicon dioxide may be dried by spraying in accordance with methods known in the art. Or it can be obtained wet buildup of silicon dioxide, which may re-suspenderbelt and trasportirovanie, and delivered in the form of suspensions or in the form of a filter cake. In most cases the drying product of silicon dioxide, is described in this work can be carried out using any standartmoreprodukt, used for drying of silicon dioxide, for example, can be used in spray drying, drying with the use of nozzles (for example, drying tower or fountain type), drying in a stream of hot air, drying in a rotating drum or drying in an oven or drying in a fluidized layer. The dried product of silicon dioxide should normally contain from 1 to 15 wt.% the humidity. The nature of the reaction product of silicon dioxide and a method of drying known to affect bulk density and throughput of liquid.

According to other aspects, the product of silicon dioxide may be subjected to various treatments depending on the nature of the desired product of silicon dioxide. For example, after the accumulation of a product of silicon dioxide, the pH of the suspension of silicon dioxide can be adjusted, for example reduced through the use of acid, such as sulfuric acid, followed by filtration and washing. According to this example, the product of silicon dioxide may be washed to the desired conductivity, for example, from 1500 to 2000 µs µs, followed by drying, as discussed above.

To further reduce the size of the dried product of silicon dioxide, if required, can be used standard equipment for grinding and crushing. For grinding can be used Molotkova is or pendulum mill in one or more passes, and fine grinding can be obtained using zhidkostnuyu or vostokstrojj mill. The products are crushed to the required size, can be separated from the products of another class size using standard methods of separation, for example by using cyclones, classifiers or vibrating sieve with a suitable mesh size, and the like.

There are also ways to reduce the particle size of the resulting product of silicon dioxide prior to extraction and/or during the synthesis of the product of silicon dioxide affect the size of the dried product or a product in the form of suspension. They include, but are not limited to, the use of the grinding material, the use of equipment with high shear (for example, a pump with a high shear or rotor-stator mixers) or ultrasonic devices, which according to some aspects can be used during the process of obtaining, for example, in the recirculation loop. Reducing the size of particles that are performed for a wet product of silicon dioxide, may be made at any time before drying.

The product silicon dioxide

Using the disclosed method can be obtained in different types of product silicon dioxide, depending on the starting materials and process conditions. According to one aspect, prod the points of silicon dioxide according to the invention have a coefficient of absorption of up to 100 cm 3/100 g According to this aspect, at least 80% of particles of silicon dioxide have the shape from rounded to rounded. These particles of silicon dioxide have a coefficient of sphericity (S80) higher than 0.9 and the amount of abrasive wear on the brass-Airliner less than 8.0 mg loss/100,000 revolutions.

In this context, a "rounded" particles are particles having slightly rounded corners with flat faces and small included angles, almost missing. "Rounded" particles - particles with homogeneous granular convex contour without flat faces, corners or distinct incoming angles.

Determination of the shape of particles of silicon dioxide of the invention as rounded to rounded perform in accordance with the following method. Select a representative sample of particles of silicon dioxide and examined with a scanning electron microscope (SEM). Make snapshots at two different levels of magnification, which are typical for the entire image as a whole. The first picture makes when increasing approximately 200 times and used to assess the homogeneity of the sample. Next, evaluate the next picture SEM with magnification of approximately 20,000 times. Preferably, in the picture were shown the least about 20 particles, it should take care to ensure that the shot from Ajeet the sample as a whole. Particles depicted image is then assessed and classified in accordance with Table 1. At least 80% of the particles of the invention have coefficients of absorption of up to 100 cm3/100 g, can be described as having the shape from rounded to rounded.

Table 1

Characteristic coolness particles

ClassDescription
UnroundedPronounced faces with sharp corners. Clearly marked with large included angles with numerous small included angles.
Bad
roundedStrongly expressed a flat surface with rounded starting the rounding of the corners. Small included angles are smoothed, and large included angles are preserved.
PolyoxetanesSlight flat surface with well-rounded corners. There are several small and slightly rounded incoming angles and large included angles weakly expressed.
RoundedA flat surface is practically absent, all corners are slightly behind rugley. Small included angles no
RoundedFlat surfaces, corners or distinguishable incoming angles are not available, the contours of a homogeneous convex grains.

In order to assist in the description of coolness of the particles, you can use the schematic images of the standard contours, shown in Fig. 8. Particles that are displayed on the enlarged SEM images, is compared with a standard chart of control the roundness of the particles is shown in Fig. 8 and classify accordingly. This method is usually used when studying the processes of sedimentation. As a particular example, the particles depicted in Fig. 3-5, obtained using the disclosed method, were classified on the basis of comparison with Fig. 8, from rounded to rounded by nature, which means that at least 80% of the particles have the shape from rounded to rounded. In contrast, the products of silicon dioxide, is shown in Fig. 6, obtained in the standard periodic process, when compared with Fig. 8 were classified as predominantly unrounded, poorly rounded and polyoxetanes, as you may have noticed planar faces and surfaces, jagged edges.

Particles of silicon dioxide of the invention, with the coefficients of absorption of less than 100 is m 3/100 g, can also be characterized in accordance with the coefficient of roundness. In this context, a "roundness coefficient" is defined as the ratio of the radius of curvature of the corners and edges to the radius of the largest circle inscribed in the particle. The coefficient of roundness can be calculated by the following equation:

KabouteffandCandentKpyglaboutwith atand=(r)/NR

where r is the radius of curvature of each corner, N is the number of corners, a R is the radius of the largest circle inscribed in the particle. Each radius of curvature, r, is calculated and summed. Next, the average value by dividing by the number of angles. Then the obtained value is divided by the radius of the largest inscribed circle, R. This process can be done manually or by using commercially available software for graphical analysis using snapshot SEM with magnification of 20,000 times.

In Fig. 9 r1...r5are the radii of curvature of each of the corners, a R is the radius of the largest circle inscribed in the particle. For example, the grain proper SF is historical forms, having a radius of curvature equal to the average radius of the maximum inscribed circle has a roundness coefficient of 1.0. As the number of faces and surfaces in the particle increases, the numerator in the equation is reduced and the overall roundness of the particles decreases. Roundness is discussed in detail in the "Stratigraphy and Sedimentation (Stratigraphy and sedimentation)," 2thedition, Krumbein and Sloss (1963), incorporated herein by reference for the study of roundness.

According to one aspect, the particles of silica of the invention have a coefficient of absorption of up to 10 cm3/100 g, where at least 80% of particles of silicon dioxide have a coefficient of roundness of at least 0.8 or, more preferably, at least 0,9. Such particles of silicon dioxide have a coefficient of sphericity (S80) higher than 0.9 and the amount of abrasive wear on the brass-Airliner less than 8.0 mg loss/100,000 revolutions. At least 80% of these particles can also be classified by comparison with the contours shown in Fig. 8 as having the shape from rounded to rounded, as noted above. The method of calculation of the coefficient of roundness is the same as shown above, evaluate a representative sample that contains, preferably, at least 20 particles on the image SEM with magnification of 20,000 times.

Particles of silicon dioxide from the retene, having the coefficient of absorption of up to 10 cm3/100 g, also have a coefficient of sphericity (S80at least 0,9. In this context, "S80define and calculate as follows. Picture SEM, magnified 20,000 times, showing a representative sample of the particles of silicon dioxide, import software for working with photos and draw the contour of each particle (two-dimensional). Particles that are close to each other, but not attached to each other, the estimation should be considered as individual particles. Then the contour of the particles fill color and the picture is imported into the software for the description of particles (for example, IMAGE-PRO PLUS from Media Cybernetics, Inc., Bethesda, Maryland), allowing to determine the perimeter and area of the particles. Further, the sphericity of the particles can be calculated by the following equation.

The sphericity=perimeter24πx square,

where the perimeter is the perimeter, as measured by the software, based on the pattern of the contour of the particle, and area is the area measured by the software within the defined perimeter of the particle.

The above calculation is performed for the each particle, which is completely placed on the SEM image. Then the obtained values are sorted by size and the lowest 20% of these quantities drop. The remaining 80% of these average values and get S80. For example, it was found that the coefficient of sphericity (S80for particles, is shown in Fig. 5, of 0.97.

In most cases, was not observed that the particles of silicon dioxide with coefficients of absorption of greater than 100 cm3/100 g have the same high degree of sphericity and roundness, as particles of silicon dioxide, discussed above. However, such particles have the ability to increase the viscosity, as well as provide a very good cleansing properties, entering into the compositions of the means to care for your teeth. Example images of such particles is shown in Fig. 7, representing a snapshot of sample 2F, which will be discussed in Example 2 below.

Thus, according to another aspect, the particles of silica of the invention may have a coefficient of absorption above 100 cm3/100 g of These particles may not have the same roundness and sphericity as particles, discussed above, with the coefficients of absorption of up to 100 cm3/100, However, particles of silicon dioxide having a coefficient of absorption above 100 cm3/100 g, are characterized as having a particle size of from 3 to 15 microns and will be the in most cases possess the degree of plaque removal (PCR) at 20% load of silicon dioxide, at least 85, for example, from 85 to 120.

Particles of silicon dioxide of the invention are also characterized by a number of other properties that will be discussed below. The following typical properties are treated as particles having coefficients of absorption of up to 100 cm3/100 g, and the particles with a coefficient of absorption of greater than 100 cm3/100 g, unless otherwise noted.

The median particle sizes of the silica of the invention was determined at various stages during the process and after or before various stages of processing particles. In this context, the median particle size, average particle size (APS) and D50refers to the particle size for which 50% of the sample is smaller and 50% of the sample size is larger.

According to one aspect, the particles of silicon dioxide of the invention, present in the liquid reaction medium, have a median particle size of from 3 to 10 μm, preferably from 3 to 8 μm and, more preferably, from 4 to 6 μm. In some specific examples the median particle size of silicon dioxide in the liquid reaction medium is from 5 to 6 μm. To determine the median particle size in the liquid reaction medium from recirculating the reaction zone can be taken aliquot sample of the liquid reaction medium, for example, using volumetric displacement, and contained in a liquid the particles b is to be parsed.

After unloading product of silicon dioxide from the loop reaction zone and the drying product of silicon dioxide, but before any of the stages of grinding, the resulting particles of silicon dioxide have a median particle size of from 3 to 25 μm. In some examples, the particles of silica after drying, but before chopping, have a median particle size of from 3 to 15 μm. According to other examples, the particles of silica after drying, but before chopping, have an average particle size of from 4 to 8 microns.

As noted above, to reduce the particle size of the dried silicon dioxide can be used for grinding. For example, after grinding on the Raymond mill or grinding the air flow particles of silicon dioxide in most cases will have a median particle size of from 3 to 10 μm. According to some specific examples, the particle of silicon dioxide after grinding (including grinding at the mill Raymond and/or grinding the air flow) has a size of from 3 to 7 μm, or even from 5 to 7 microns.

In most cases it was observed that the size of the dry particles, the sphericity and roundness of particles were associated with the structure of silicon dioxide. When the lower structure after drying, received a higher percentage rounded/more spherical particles with a small change in particle size distribution of particles in liquid reactio the Noah environment (suspension). With increasing structure level rounded particles more spherical decreased, and the average particle size after drying was increased. Samples with higher structures can be reduced to the size of particles in suspension using light grinding at the mill Raymond. More intensive grinding using Raymond mill and grinding the air flow essentially did the particle size is much smaller than the size of particles in suspension. Grinding products, low structure did not lead to a significant change in particle size. The structure of the particles of silicon dioxide, typically linked with oil absorption. Silicon dioxide with a low structure, thus, has a low oil absorption, whereas silicon dioxide with a high structure has a high oil absorption.

The median particle size was determined when the device is used to measure the scattering of laser radiation Model LA-930 (or LA-300, or equivalent), available from Horiba Instruments, Boothwyn, PA (Botvin, Pennsylvania).

Typically, particles of silicon dioxide of the invention have a narrow particle size distribution of the particles. The particle size distribution of the particles can be estimated on the basis of several parameters, including the coefficient of uniformity coefficient of the curve of the particle size distribution and the symmetry of the distribution. The coefficient of uniformity (Cu defined as D 60/D10. The coefficient of the curve of the particle size distribution (SS) is defined as (D30/(D10× D60)). The symmetry of the peak can also be defined as (D90-D50)/(D50-D10), where the shape factor, equal to 1.0, will fit perfectly symmetrical curve. The coefficients of the homogeneous particles of silicon dioxide typically range from 1.8 to 2.5. The coefficients of the curve of the particle size distribution typically ranges from 0.2 to 0.31, and the values of the shape factor usually ranges from 1.3 to 1.7. According to some specific examples, the symmetry of the peak varies in the range from 1.3 to 1.5, indicating a very symmetrical distribution of the particles of silicon dioxide.

Particles of silicon dioxide of the invention have values of moisture absorption in the range from 57 to 272 cm3water per 100 g of silicon dioxide, although the magnitude of moisture absorption can be increased. The values of moisture absorption is determined using absorptometry "With" viscometer with coaxial cylinders of company C. W. Brabender Instruments, Inc. Approximately 1/3 Cup of silicon dioxide (or silica) are placed in the mixing chamber of absorptometry and stirred at 150 rpm then add water with a speed of 6 ml/min and record the torque required for mixing powder the crustacean leaves substances. As the water is absorbed by the powder, the torque will reach the maximum value, because the powder from unrestricted current powdery substance turns into a paste. The total amount of water added, which gives the maximum torque, then standardize for the amount of water that can be absorbed per 100 g of powder. Since the powder is used as a working weight (not pre-dried), the amount of free moisture powder is used to calculate the "value AbC water adjusted for moisture content in accordance with the following equation:

Andbarbri I water=absorbed water (cm3)+% moisture(100 (g) -% moisture)/100

Absorptometry usually used for determining the oil absorption of the carbon black in accordance with ASTM D 2414, methods b and C, ASTM D 3493.

As mentioned above, according to one aspect, the particles of silica of the invention have coefficients of absorption of up to 10 cm3/100 g, for example from 30 to 100 cm3/100 g, while, according to another aspect, the particles of silicon dioxide have coefficients of absorption above 100 cm3/100 g, for example, varioation more than 100 cm 3/100 g to 150 cm3/100 g In most cases it was observed that the particles of the silicon dioxide of the invention have values of absorption in the range from 30 to 171 cm3(cm3or ml) oil absorbed per 100 g of silicon dioxide.

The coefficients of absorption was determined by the method of grinding with oil (ASTM D281). This method is based on the principle of mixing linseed oil with silicon dioxide by grinding a mixture of linseed oil/silicon dioxide with a spatula on a smooth surface until, until it forms a paste, similar to a thick putty. By measuring the amount of oil required to obtain a pasty mixture which will form the curls at the smear, it is possible to calculate the coefficient of absorption of the silicon dioxide - value, representing the amount of oil required per unit mass of silicon dioxide to saturate the sorption capacity of silicon dioxide. A higher level of absorption indicates a higher structure of silicon dioxide. A low value is an indication that Nicostratus by silicon dioxide. The coefficient of absorption can be determined using the following equation.

Mandwith alaboutemKaboutwith atb=cm 3paboutglaboutyennaboutgaboutmandwith alandweight of silicon dioxide (g)×100=with am3absorbed oil100 g of silicon dioxide

Particles of silicon dioxide of the invention typically have a specific surface area BET (according to the method of brunauer-Emmett-Taylor) in the range from 10 to 425 m2/, According to some particular examples, the particles of silicon dioxide have a BET specific surface in the range from 10 to 300 m2/g and, preferably, from 50 to 350 m2/g Specific surface area BET disclosed particles of silicon dioxide was determined by the method of nitrogen adsorption is carried BET in accordance with the work Brunaur et al., J. Am. Chem. Soc, 60, 309 (1938), which is incorporated herein by reference for the study of the measurement of the specific surface BET.

The specific surface BECOMING (cetyltrimethylammonium bromide) disclose particles of silicon dioxide typically is in the range from 10 to 250 m2/g and, according to some examples, from 50 to 200 m2/g Specific surface BECOMING silicon dioxide is determined by the absorption of BECOMING (cetyltrimethylammonium bromide) surface of silicon dioxide excess is separated by centrifugation and the presence of surface-active electrode spend titrimetrically determination using lauryl sodium. In particular, in a beaker with a capacity of 250 ml containing 100,00 ml solution BECOMING (5.5 g/l), placed approximately 0.5 g of silicon dioxide, stirred for 1 hour using an electric mixing plate, then centrifuged for 30 minutes at a speed of 10000 rpm/min To 5 ml of the clear supernatant liquid in a beaker with a capacity of 100 ml add 1 ml of 10% solution of Triton X-100. The pH is adjusted to 3.0 to 3.5 with 0.1 N HCl solution and the sample is titrated 0,0100 M solution of sodium lauryl when using a surfactant electrode (Brinkmann SUR1501-DL) to establish the equivalence point.

The amount of mercury (Hg), introduced in the disclosed particles of silicon dioxide, typically ranges from 0.5 to 3 ml/g Volume of added mercury or total pore volume (Hg) is determined by the method of mercury porometry when using the apparatus Micromeritics Autopore II 9220. The pore diameters can be calculated by the equation Washburn (Washburn), using wetting angle theta (Θ) equal to 130° and a surface tension gamma equal to 485 Dyne/see Mercury is forced into the voids of the particles depending on the pressure and the volume of mercury introduced in one gram of sample, calculated for each set-point pressure. The total pore volume, in the context of this document, is characterized by the total volume of mercury introduced under pressure the x in the range from vacuum to 60,000 psi (pounds per square inch). Build dependency increases volume (cm3/g) under given pressure value from the radius or diameter of the pores corresponding to increases of pressure setting. The peak on the curve according to the entered amount from the radius or diameter of the pore corresponds to a variant of the distribution of pore size and characterizes the most common size of the pores in the sample. In particular, the size of the sample is brought to 25-75% of the volume of the plunger in powder penetrometer when the volume of the vessel 5 ml and the volume of the plunger equal to about 1.1 ml of Mercury fills the pores at pressures in the range from 1.5 up to 60,000 psi with a 10 second equilibrium times for each of the approximately 103 points in the data set.

An aqueous solution of the particles of the silicon dioxide of the invention will in most cases be the amount of abrasive wear on the brass-Airliner (BEA) less than 10 mg loss per 100,000 revolutions, preferably, less than 8 mg loss per 100,000 revolutions, and, more preferably, less than 5 mg loss per 100,000 revolutions. The value of BEA in most cases will be at least 1. Private range, BEA includes from 1 to 10, 1 to 8, 1 to 7 and 1 to 5 mg loss per 100,000 revolutions.

Testing abrasive wear on the brass-Airliner (BEA) used to determine the hardness of the products of the silicon dioxide of the invention, the detail is on is described in the patent document US 6616916 Karpe et al., which are incorporated herein by reference for the study of abrasive wear testing on BE, this test includes the apparatus for testing the abrasion of Airliner (Einlehner) at-1000, used as follows: (1) brass wire mesh Fourdrinier (Fourdrinier) is weighed and exposed to 10% aqueous suspension of silicon dioxide within a certain period of time; (2) then determine the amount of abrasion in milligrams of weight loss of brass wire sieves Fourdrinier per 100,000 revolutions. The result, measured in mg loss, can be characterized as the amount of abrasive wear on Airliner corresponding to 10% loss of brass.

The brightness level (on the device Technidyne) particles of silicon dioxide typically is in the range from 95 to 100. According to some specific examples, the brightness level (Technidyne) lies in the range from 97 to 100 or even from 98 to 100. To measure white fine powdery silicon dioxide pressed into tablets with a smooth surface and analyzed with the help of the device Technidyne Brightmeter S-5/BC. This device has a two-beam optical system, where the sample light at an angle of 45°, and the reflected light is observed at an angle of 0°. This method conforms to TAPPI test Kzt452 and T and ASTM D985. Powder materials are pressed into tablets size when listello 1 cm under the action of pressure, sufficient to receive the tablets of the surface that is smooth and does not have showered particles or Shine.

Dispersion disclosed particles of silicon dioxide will be in most cases to have a refraction index (RI) is greater than the 1.4. According to some examples, the dispersion of expandable particles of silicon dioxide has a value RI from 1.4 to 1.5. Generally, dispersions are transmittance (%T) in the range from 20 to 75.

To measure the refractive index and the degree of light transmission was preparing a series of uterine solutions of glycerin/water (approximately 10), so that the refractive index of these solutions was in the range of from 1,428 to 1,460. Typically, these uterine solutions will overlap the range from 70 wt.% up to 90 wt.% glycerin in water. To determine the value of RI one or more drops of each standard solution separately inflicted on the fixed plate of the Refractometer (Abbe 60 Refractometer Model 10450). Cover plate secured and fixed in place. Included light source and the Refractometer and read the testimony of the refractive index for each standard solution.

In individual tubes with a capacity of 20 ml was weighed 2.0+/-0,01 ml disclosed product of silicon dioxide was added to 18.0+/-0,01 ml of each of the corresponding mother liquor glycerin/water (dsproducts measured by the oil absorption, in excess of 150, the test used 1.0 g deployable product of silicon dioxide and 19.0 g of the mother liquor glycerol/water). The tube was intensively shaken for formation of a dispersion of silicon dioxide, and then the tubes were removed tube and the tubes were placed in a desiccator, which was evacuated using a vacuum pump (approximately 24 inches RT.V.).

After this dispersion was wearisomely for 120 minutes and were visually evaluated for the detection completeness deaeration."%T at a wavelength of 590 nm (breakers 20 D+) was measured after the specimen temperature was returned to room values (approximately 10 minutes), in accordance with the working instructions of the manufacturer. The value of the %T was measured to disclose product of silicon dioxide by placing aliquot of each dispersion in a quartz cuvette and reading values %T at a wavelength of 590 nm for each sample on a scale of 0-100. The percentage transmittance depending on RI mother solutions were applied to the curve. The value RI of silicon dioxide was determined as the position of the maximum peak on the graph (the y or X value) of the curve representing the dependence of %T from RI. The value of Y (or x-coordinate) maximum peak corresponded to %T.

Particles of silicon dioxide can be filtered and washed with water to reduce the content of sodium sulfate ((s) if the Oh is present) to an acceptable level. Rinsing of the product of the reaction is usually carried out after filtration. The pH-value of the washed precipitate filtered can be adjusted, if necessary, before proceeding to the subsequent stages described in this context. The content of sodium sulfate in the particle of the silica of the invention may be approximately 6%. The content of sodium sulfate was measured conductivity of a suspension of silicon dioxide of known concentration. In particular, in the bowl of mixer Hamilton Beach Mixer, model Number 30, with a capacity of 1 quart, weighed 38 g of the sample in the form of a wet sludge of silicon dioxide was added 140 ml of deionized water. The suspension was stirred for 5 to 7 minutes, after which the suspension was transferred into a measuring cylinder 250 ml cylinder filled with deionized water to the mark of 250 ml using water for rinsing the bowl of the mixer. The sample was mixed by inverting the measuring cylinder (closed) several times. To determine the conductivity of the suspension used a conductivity meter, such as Cole Parmer CON 500 Model #19950-00. The content of sodium sulfate was determined by comparing the conductivity of the sample with a standard curve obtained using known methods to add suspensions with the composition of the sodium sulfate/silicon dioxide.

Composition means to care for teeth

Product dioxide silicon image the shadow is particularly useful for use in compositions of funds for the care of teeth as part of, or just cleaning or abrasive agent. In this context, "composition means to care for teeth" refers to compositions that can be used to maintain the hygiene of the oral cavity, for example, by cleaning the accessible surfaces of the teeth. The composition of the funds for the care of teeth can be a liquid, powdery or pasty.

Typically, the composition of the funds for the care of teeth are composed mostly of water, detergent (cleaning agent), moisture retaining substances, binders, flavours and food additives and fine abrasive (disclosed product of silicon dioxide). Particles of silicon dioxide of the invention, being a part of the compositions of funds for the care of teeth, may be present in amounts from about 5% to 50 wt.%, preferably, from about 10% to 50 wt.% and, more preferably, from about 10% to 35 wt.%. As a particular example, the composition of the funds for the care of teeth may include particles of silicon dioxide in the amount of about 20 wt.%.

The approximate composition of the funds for the care of teeth or composition for cleaning the oral cavity may include any one or more of the following ingredients in any reasonable quantity, for example, in the following amounts (wt.%). The thickening agent on the basis of silicon dioxide in p is evidena following example can be any thickener, known in the art, such as products ZEODENT, as listed below, and/or may include particles of silicon dioxide according to the invention. The abrasive preferably contains particles of silicon dioxide according to the invention in amounts shown in Table 2.

Table 1
The ingredients and relative amounts approximate composition tools to care for your teeth
The approximate composition of treatments for teeth
IngredientNumber, wt.%
Water-retaining substance (substances) (total)5-70
Deionized water5-70
Binder0,5-2,0
Therapeutic agent0,1-2,0
Helatoobrazovatel0,4-10
Thickener0-15
Surfactant0.5 to 15
Abrasive10-50
Sweetener<1,0
Dye<1,0
Aromatic and flavoring<5,0
Preservative<0,5

Disclosed particles of silicon dioxide can be used separately as an abrasive in the composition of the funds for the care of teeth or as an additive or co-abrasive together with other abrasive materials discussed in the context of this document or known in the art. Thus, any number of other standard abrasive additives may be present in the composition of the funds for the care of teeth according to the invention. Other such abrasive particles include, for example, precipitated calcium carbonate (PCC), ground calcium carbonate (GCC, chalk, bentonite, dicalcium phosphate or its dihydrate form, gel silicon dioxide (itself, as well as any patterns), precipitated silicon dioxide, amorphous precipitated silica (by itself, as well as any patterns), perlite, titanium dioxide, dicalcium phosphate, calcium pyrophosphate, aluminum oxide, hydrated aluminum oxide, feces is tikirovanny aluminum oxide, aluminum silicate, insoluble metaphosphate sodium, insoluble metaphosphate potassium, insoluble magnesium carbonate, zirconium silicate, dispersed thermotherapies resin and other appropriate abrasive materials. Such materials may be introduced into the compositions of funds for the care of teeth to give the target composition of the polishing properties.

In addition to the abrasive component, the means to care for their teeth may also contain one or more organoleptic amplifiers. Organoleptic amplifiers include water-retaining substances, sweeteners, surfactants, perfumes and flavorings, dyes and thickeners (also sometimes known as binders, gums or stabilizing agents).

Water-retaining substances used to impart a texture or "mouth texture" means to care for their teeth, and to prevent drying means to care for teeth. Acceptable water-retaining substances include polyethylene glycol (with a range of different molecular masses), propylene glycol, glycerin (glycerol), aritra, xylitol, sorbitol, mannitol, lactic and hydrolysates hydrogenated starch and mix it. According to some specific examples, the hydrophilic substances are present in quantities of from about 20 wt.% up to 50 wt.% from compositionist for the care of teeth, for example, 40%.

Sweeteners can be added to the composition of the funds for the care of teeth (e.g., toothpaste) to give the product a pleasant taste. Acceptable sweeteners include saccharin (saccharin sodium, potassium or calcium), cyclamate (sodium, potassium or calcium salt), Acesulfame K, thaumatin, neohesperidin, dihydrochalcone, ammoniaand glycyrrhizin, dextrose, levulose, sucrose, mannose and glucose.

Surfactants can be used in compositions of funds for the care of teeth according to the invention, in order to make the compositions more cosmetically acceptable. Surfactant is preferably detergent, giving the composition cleansing and foaming ability. Acceptable surface-active substances are safe and effective amount of anionic, cationic, nonionic, zwitter-ionic, and amphoteric betaine surfactants such as sodium lauryl sulfate, dodecylbenzenesulfonate sodium, salts of alkali metals or of ammonium lauroylsarcosinate, myristoleate, palmitoylcarnitine, stearoylethanolamine and oleoresins, polyoxyethylenesorbitan the monostearate, isostearate and laurate, laurylsulphate sodium, N-laurylsarcosine, sodium, Kalieva the salts and salts of ethanolamine N-lauroyl-, N-myristoyl - or N-palmitoylcarnitine, condensates of polyethylene oxide and alkyl phenols, cocamidopropylbetaine, lauramidopropyl, palmitoylation and the like. Sodium lauryl sulfate is the preferred surface-active substance. Surfactant is typically present in the compositions to care for the oral cavity according to the present invention in amounts of from about 0.1 to 15 wt.%, preferably, from about 0.3% to 5 wt.%, as, for example, from about 0.3% to 2.5 wt.%.

In the composition of the funds for the care of teeth can also be added fragrance and flavoring. Acceptable fragrance and flavor additives include, but are not limited to the list integranova oil, oil of peppermint, oil of spearmint, oil of sassafras and clove oil, cinnamon, anethole, menthol, thymol, eugenol, eucalyptol, lemon, orange and other similar fragrances that give a fruity, spicy shades, and so forth. Such aromatic and flavoring typically include a mixture of aldehydes, ketones, esters, phenols, acids, and aliphatic, aromatic and other alcohols.

To improve the aesthetic appearance of the product may be added dyes. Suitable for use dyes include, but are not limited to the list, dyes, od the temporal appropriate regulatory authorities, such as the FDA (Food and Drug Administration and control over the quality of the food and drug administration) and the bodies listed in the European directives on food and pharmaceutical products (European Food and Pharmaceutical Directives), and include pigments such as TiO2and colorants, such as dyes FD&C (food, drug and cosmetic dyes for food, pharmaceutical and cosmetic industry) and D&C dyes, pharmaceutical and cosmetic industries).

Thickeners suitable for use in the compositions of the means to care for the teeth to provide a gel-like structure, giving toothpaste stability against phase separation. Acceptable thickeners include thickening agent on the basis of silicon dioxide; starch; glyceric starch; gums such as gum karaya (gum of sterculia), tragacanth gum, Arabia gum, ghatti gum, gum Arabic, xanthan gum, guar gum and cellulose gum; magnesium aluminosilicate (Wigan); carrageenan; sodium alginate; agar-agar; pectin; gelatin; compounds of cellulose, such as cellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxymethylcellulose, hydroxyethylmethylcellulose, methylcellulose, ethylcellulose and sulfate cellulose; natural and synthetic clays, such as g is charitonia clay; and also this mixture. Standard levels of thickeners or binders comprise from about 0 wt.% up to 15 wt.% the composition of the toothpaste.

Suitable thickeners based on silicon dioxide for use in the composition of toothpaste, for example, include as non-limiting example, amorphous precipitated silica, such as ZEODENT 165. Other preferred (but non-limiting) thickeners based on silicon dioxide are a variety of silicon dioxide ZEODENT 153, 163 and/or 167 and ZEOFREE, 177, and/or 265, all of which are available in the J. M. Huber Corporation.

A therapeutic agent can also be used in compositions for prevention and treatment of dental caries, periodontal diseases and temperature sensitivity. Examples of therapeutic agents not limited to list of sources of fluoride such as sodium fluoride, monitoroff sodium, monitoroff potassium, tin fluoride, potassium fluoride, forcricket sodium, forcricket ammonium and the like; condensed phosphates, such as chetyrehmatchevaya salt pyrophosphoric acid, chetyrehkolka salt pyrophosphoric acid, disodium salt dihydroergosterol acid, trinacria salt monohydrogenphosphate acid; tripolyphosphate, hexametaphosphate, three is metaphosphate and pyrophosphates, such as antimicrobial agents such as triclosan, biguanide, such as alexidine, chlorhexidine and chlorhexidine; enzymes, such as papain, bromelain, glucoamylase, amylase, dextranase, Matanza, lipase, pectinase, tannase and protease; Quaternary ammonium compounds such as benzalkonium chloride (BZK), chloride benzene (BZT), chloride of cetylpyridinium (ALS) and domainbased; metal salts such as zinc citrate, zinc chloride and fluoride tin; yarrow extract and sanguinarine; volatile oils, such as eucalyptol, menthol, thymol and methyl salicylate; aminofluorides; peroxide and the like. A therapeutic agent can be used in the compositions of the means to care for teeth alone or in combination with a therapeutically safe and effective level.

To prevent the growth of bacteria to the compositions of the present invention can also be added preservatives. Acceptable preservatives approved for use in compositions for the care of the oral cavity, such as methylparaben, propylparaben, and sodium benzoate may be added in safe and effective amounts.

Means on care of teeth disclosed herein can also contain a wide range of additional ingredients, such as desensibilization, substances with therapeutic action, the other is the means, preventing caries,

the chelating agents/agents, vitamins, amino acids, proteins, other means, to prevent the appearance of plaque/Tartar, cloud emulsions, antibiotics, encipherment, enzymes, regulators of pH, oxidants, antioxidants and the like.

Composition means to care for your teeth also typically includes a solvent, which is usually water. In most cases, water provides the balance of the composition in addition to the additives mentioned previously. The water is preferably deionized and does not contain impurities. The means to care for their teeth will contain from about 20 wt.% up to 70 wt.% water, for example, from 5 wt.% up to 35 wt.% water, as, for example, 11 wt.%.

A specific example of the disclosed composition the means to care for teeth is a composition comprising 10-50 wt.% disclosed particles of silicon dioxide, glycerin, sorbitol, water, CARBOWAX 600, CEKOL, Terentieva salt pyrophosphoric acid, sodium fluoride, ZEODENT, titanium dioxide, sodium lauryl sulfate, flavor and optional dye.

Composition means to care for the teeth disclosed in this document, can be estimated using a number of measurements. The cleansing properties of compositions of funds for the care of teeth is usually expressed through the degree of removal subn the second RAID ("PCR"). When testing to determine PCR to measure the ability of the composition means to care for your teeth to remove from the tooth of a film of plaque in the fixed conditions of cleaning with a toothbrush. The test for determining PCR as described in "ln Vitro Removal of Stain With Dentifrice (Removal of stains in vitro tool for the care of teeth)" G. K. Stookey, et al., J Dental Res., 61, 1236-9, 1982, which is by reference incorporated into the present work to study the PCR. Typically, compositions for the care of teeth according to the invention have a value of the PCR of at least 85 at load levels of 20%, for example, from about 85 to 107.

Size of abrasive wear of dentin by radioactive method (RDA) for compositions of funds for the care of teeth according to the invention will generally be at least 100, for example, from about 100 to 315. The RDA values for the means to care for the teeth, containing particles of silicon dioxide used in this invention is determined in accordance with the method described in the work Hefferen, Journal of Dental Res., July-August 1976, 55 (4), p.563-573 and described in patent documents U.S. Pat. Nos. 4340583, 4420312 and 4421527 author Wason, each of which are incorporated herein by reference for the study of the measurement of the RDA. The results of both PCR and RDA vary depending on the nature and concentration of the components of the composition means to care for teeth. Velich is by PCR and RDA are dimensionless.

The viscosity of toothpaste (means on care of teeth) disclose compositions funds for the care of teeth varies and can be measured by using a Brookfield viscometer Brookfield Viscometer Model RVT equipped with a Helipath spindle T-F and set to 5 rpm for measurement of viscosity of toothpaste at a temperature of 25°C at three different levels as lowering the spindle through the exposed test sample toothpaste and averaging the results. The viscosity Brookfield expressed in centipoise (SDR).

Continuous loop reactor

The method of the invention, in various aspects, can be carried out using a continuous loop reactor or a tubular reactor. Acceptable continuous loop reactor typically has an inlet for the acidifying agent, the inlet to the alkali metal silicate and an outlet for the product, all are in hydraulic communication with a continuous path defined by one or more pipes. Liquid medium in a continuous path can be recycled through various means, such as a pump located directly in the path. Other components of the continuous loop reactor can include, but are not limited to, a list of heat exchanger in the circuit for the temperature control liquid is Reda, the control valve back pressure to control the pressure and/or a built-in mixer circuit for mixing the contents of the liquid reaction medium.

In Fig. 1 presents an example of a continuous loop reactor 100 includes inlet 110 for acidifying agent for introducing an acidifying agent in a liquid loop reaction zone and the inlet opening 120 for silicate of an alkali metal for the introduction of a silicate of an alkali metal in a loop reaction zone. Loop reaction zone defined by one or more pipes 130, limiting continuous loop. In a continuous loop reactor 100 may also be present and some other components, including the pump 140 to recirculatory liquid medium through one or more pipes 130. During the process according to the invention the pump 140 must have a hydraulic connection with the liquid reaction medium. A continuous loop may also have a hydraulic connection with integrated mixing device 150. In the example shown in Fig. 1, inline mixing device 150 also has a hydraulic communication with the inlet opening for acidifying agent and serves both to facilitate entry acidifying agent in a continuous loop, and for mixing the liquid medium inside the loop reaction zone. what also may be present heat exchanger 160 to control the temperature of a liquid medium in a continuous loop. Heat exchanger 160, thus, is in thermal contact with one or more pipes 130, defining a continuous loop. Because the reaction is continuously added acidifying agent, a silicate of alkaline metal or other liquid, as noted above, fluid will flow from a continuous path and leave a loop reaction zone through an outlet 170 for the product. Then the product is collected. In accordance with the private aspect, the reaction can be equipped with one or more devices for regulating the pressure in hydraulic communication with one or more pipes 130, such as the control valve back pressure (not shown) for regulating the pressure within the loop reactor.

With a loop reactor can be used by any acceptable pump 140. Inline mixing device 150 is used partly to ensure environment with high shear for recirculatory liquid medium, it is preferably an in-line mixer of the rotor/stator type. Examples of suitable rotor/stator mixers include built-in mixers SILVERSON, such as SILVERSON Model 450LS manufactured by the company SILVERSON Machines, Inc.; or mixers, commercially available from the company IKA-Works Inc., Wilmington, N. C. 28405, as well as from the company's Charles Ross and Son Compay, Hauppage, N. Y. 11788, including models of the ME-410/420X and 450X.

DESCRIPTION of embodiments of the INVENTION

The following examples are used to provide professionals in the art a complete disclosure and description of how received and evaluated compounds, compositions, articles, devices and/or methods claimed herein; they are provided solely as an example of the invention and are not intended to limit the scope of what the inventors regard as their invention. Attempts were made to ensure the accuracy of numerical data (e.g., amounts, temperature, and so on), but you should take into account some inaccuracies and errors. Unless otherwise stated, parts are mass parts, the temperature is expressed in PS or corresponds to the ambient temperature, and the pressure is atmospheric or close to atmospheric.

Example 1

Continuous loop reactor

Continuous loop reactor was equipped with a recirculation loop, where the reaction suspension was able to repeatedly circulate before it is unloaded (see Fig. 1). Loop recirculation consists of sections of rigid pipes connected together by sections of flexible hose. The inner diameter of the pipe/hose approximately 1". On one side of the loop was placed pump to compass the AI of the reaction mass, and on the opposite side was installed in-line mixer SILVERSON to provide additional shift efforts, as well as for use as an inlet for the introduction of the acidifying agent. Between the pump and the mixer was set a static mixing heat exchanger (KENICS Model 1-Pilot-HT-EX 32, available from the company Chemineer, Inc., Dayton, Ohio) to provide a means of temperature control during retrieval of silicon dioxide. The discharge pipe located after the inlet for acidifying agent, allows to unload the product depending on the speed with which adding silicate and acidifying agent. The discharge pipe can also be fitted with a valve back pressure, allowing the reactor to operate at temperatures above 100°C. the Pipe for discharging the product can be designed to collect the product in a container for subsequent changes (e.g., for adjustment of pH), or the product can be unloaded directly onto the filter rotor type or filter press. Optional in-line unloading of a product may also be added to the acid in order to avoid regulation of pH after synthesis in the case when the product is obtained at pH values above 7,0.

Example 2

Preparation of product dioxide credit the deposits

Product of silicon dioxide was prepared using a continuous loop reactor described in Example 1. Before the introduction of the acidifying agent and a silicate of an alkali metal in a continuous loop reactor was initially added precipitated silicon dioxide, sodium sulfate, sodium silicate and water and recycled speed 80 l/min In this context it is called the liquid reaction medium, which may be added additional acidifying agent and a silicate of an alkali metal, as noted above. This initial stage was completed to fill the recirculation loop indicative content and concentrations typical load, to thereby minimize the purge time before collecting the desired product of silicon dioxide. It is assumed that this stage also minimizes the gelation in the contents of the loop reactor. However, it should be noted that the acidifying agent and a silicate of an alkali metal can be added directly to the loop reactor, filled only with water without gelling or binding system. Thus, the liquid reaction medium before the introduction of the acidifying agent and a silicate of an alkali metal may include water without crystal seed of silicon dioxide.

Preparing a solution of 1.5 kg ZEODENT 103, 1.34 kg of sodium sulfate, 11,1 l of sodium silicate (2,65 MR, 13,3%) in 20 l of water. the ATEM approximately 15.5 l of this solution was added to the recirculation loop loop reactor and then heated to a temperature of 68°C. Content recycled speed 80 l/min with built-in mixer SILVERSON in the recirculation loop, operating at 60 Hz (3485 rpm). Sodium silicate (2,65 MR, 13.3%) and sulfuric acid (11.4 percent) was added in the loop simultaneously with the feeding speed of silicate of 1.7 l/min and feed rate of acid sufficient to maintain a pH of 9.5. If necessary, the feed rate of the acid was adjusted accordingly to maintain the pH. The acid and the silicate was added under these conditions for 40 minutes to blow the unwanted silicon dioxide from the system before collecting the desired product of silicon dioxide. After 40 minutes, the collection was drained and its contents were unloaded. The acid and the silicate was added continuously as the product of silicon dioxide was collected in the collection under stirring at a speed of 40 rpm, at the same time maintaining the temperature at approximately 60°C (unless otherwise specified, the temperature in the collection was the same as the reaction temperature). After accumulating the required number of product silicon dioxide feed acid and silicate was stopped. The contents of the loop were left to circulate. The pH value of the product of silicon dioxide in the collection was brought to 5.0, manually adding sulfuric acid, then filtered and washed to obtain a conductivity of approximately 1500 µs and then dried.

Of the specimens with 2V on the 2ND received in terms shown in Table 3.

Samples from 2F on 2S were obtained in accordance with example 2A except that at the stage of washing/filtering does not regulate the pH value. Before drying, the pH of the product was brought to 5.5 by adding manually diluted sulphuric acid.

Sample 2J received in accordance with the sample 2F except that the pH was brought to 6.5 before drying.

The 2N sample were obtained using a continuous loop reactor, as described above, except that from the built-in mixer SILVERSON removed the stator.

Table 2
A brief overview of the reaction conditions for samples with 2A through 2S
SampleSulfuric acid (%)Sodium silicate (%)The rate of recirculation (l/min)The average number of passesSilverson, rpmThe speed of adding silicate (l/min)PHthe pace. Retz.(C )
2A11,413,38029 34851,79,568
2B11,413,3431634851,79,570
2K11,413,3802117432,69,558
2C11,413,3802136002,69,558
2D11,413,3802017432,69,593
2ND11,413,38020 34852,69,593
2F11,413,3801934852,67,243
20the 5.76,7802634851,77,568
2Gof 17.019,5802834851,77,568
2L11,413,3721817432,67,233
2M11,413,38029 17431,77,394
2N11,413,3802817431,77,594
2Jof 17.019,5773034851,77,5122
2H11,413,3802817431,75,545
2111,413,3802717431,72,544
2Pof 17.019,52019 34850,567,695
2Qof 17.019,5403734850,567,595
2Rof 17.019,5607134850,568,295
2S11,413,3802934851,77,094

In Table 3 acidifying agent and a silicate of an alkali metal added with the specified speed and maintained at a given percentage of the liquid reaction medium. Acidifying agent was sulfuric acid, and the alkali metal silicate is sodium silicate.

The average number of passes, or the approximate number of times that this particle will move around collecting loops, pre the de than it will unload, can be calculated as follows. The following equation, the time of the product of silicon dioxide in the recirculating loop before discharge is calculated by dividing the volume of the system at the rate of raw material (the speed of adding silicate + the rate of addition of acid. After that, the number of passes/minute can be calculated by dividing the speed of recirculation on the volume of the system. Further, the residence time can be multiplied by the number of passes/minute to obtain the average number of passes.

The residence time (min)=system capacity (l)The total rate of addition of raw materials (l/min)

The number of passes/min=with aKaboutpaboutwith atbpeCandpKylICandand(l/mandn)aboutbbemwith aandwith atems(l)

The residence time (min)× the number of passes(min)=with apedneehandwith alaboutppaboutxaboutdaboutin

Increasing the average number of passes characteristics of sphericity and roundness of the particles is improved.

In most cases, continuous loop reactor could easily support the specified conditions during the reaction. As noted above, the specified rate of silicate feed rate of the acid regulate to obtain the desired pH. After stabilization, the feed rate of the acid in the given conditions can be maintained in continuous operation. Regulation of pH reaches a velocity change of adding acid. Conditions with a pH range from 2.5 to 9.5 and a temperature in the range from 24 to 122°C was studied in a special way, this was not observed any blocking or gelation of the liquid reaction medium.

Example 3

Particles of silicon dioxide, obtained from Example 2

Described products of silicon dioxide, obtained in Example 2. It was found that the particle size of the reaction slurry (particle size in a loop recycling) in most of the studied reaction conditions is, as a rule, will bring the flax 4-8 μm, the majority of samples fell in the range of 4-6 microns. The size of the dry particles and the sphericity/roundness of the particles was directly correlated with the structure of silicon dioxide. When the lower structure after drying, received a higher percentage not agglomerated particles with high sphericity and roundness with a slight change in relation to the particle size distribution of the particles in suspension. With the increasing patterns the level of agglomeration of particles was increased, the sphericity and roundness of particles decreased, and the average particle size during the drying time increased.

Samples with higher structures can be reduced to the size of particles in suspension using light grinding at the mill Raymond. More intensive grinding using Raymond mill and grinding the air flow essentially did the particle size is much smaller than the size of particles in suspension. Grinding products, low structure did not lead to a significant change in particle size. Size distribution of particles of silicon dioxide, obtained using the continuous process, were Gaussian and usually less extensive than in the case of precipitated silica obtained by standard methods. The size of the particles in suspension, after drying, by spraying, after grinding at the mill Raymond and parabolica air, obtained using the continuous loop reactor, are presented in Table 4. For the remaining examples, the samples are not dried silicon dioxide labeled samples after grinding at the mill Raymond - "-2" and the samples after grinding the air flow - "-3." Size distribution of particles for a product of silicon dioxide, obtained using the continuous loop process and using standard processes shown in Fig. 2.

Table 3
The particle size of products of silicon dioxide in suspension, after spray drying and after grinding, obtained using the continuous loop process
SampleAPSb suspension (Horiba median, mm)APS dry particles (Horiba median, mm)APS after grinding at the mill Raymond (Horiba median, mm)APS after grinding the air flow (Horiba median, mm)

SampleAPS suspension (Horiba median, mm)APS dry particles (Horiba median, mm)APS after grinding
the mill, Raymond (Horiba
median, µm)
APS after grinding the air flow (Horiba median, mm)
2A4,88,8--
2Bof 5.410,36,2of 5.4
2C5,312,2of 5.4-
2D4,54,8-5,0
2NDthe 3.85,3-4,4
2F6,418,1the 5.7the 5.7
2G5,19,35,9of 5.4
2H-26,111,7-
21 -19,610,5-
2J4,25,5-4,6
2Kof 5.412,4--
2L8,220,4--
2Mthe 5.78,0--
2Nthe 4.78,0--
20the 4.714,2--
2P-7,2--
2Q5,06,3--
2R 4,3of 5.4--
2S4,67,5--

The reaction conditions described above and shown in Table 3, allowed us to obtain products of silicon dioxide with structures from "low" to "moderately high structures, with coefficients of absorption in most cases in the range from 32 to 171 cm3/100 g AbC Values adjusted moisture absorption of the products obtained silicon dioxide ranged from 57 to 272 cm3/100 g Specific surface BECOMING ranged from 10 to 250 m2/g Specific surface area BET, ranging from 17 to 425, were higher than for typical materials deposited silicon dioxide, obtained using the standard periodic processes. Features for white products of silicon dioxide, obtained using the continuous process, were very good, too, probably due to their high sphericity and roundness. Products of silicon dioxide, obtained using the continuous process disclosed in this document, in most cases, had a brightness level above 96, except for products polucen the x at pH less than 7. Physical properties of products of silicon dioxide, obtained using the disclosed method, are presented in Table 5.

Table 4
Physical properties of samples from a continuous reactor
SampleAbC water (cm3/100g)The oil absorption (cm3/100g)Specific surface area BET (m2/g)The specific surface BECOMING (m2/g)Na2SO4(%)H2O(%)Put the amount of Hg (ml/g)5% PHWhite (Technidyne)
2A-17968232505,236,51,794,697,7
2B-111488207800,747,1 1,818,598,6
2B-210064120520,517,51,308,797,5
2B-310174120660,518,00,828,7of 97.8
2C-1139106353950,357,9to 2.068,998,3
2C-210983178980,357,60,749,096,4
2D-160133290,356,51,138,7of 98.2
2D-3756055280,358,11,098,998,3
2E-17860219320,357,71,167,398,3
2E-37058149280,358,10,997,798,1
2F-12121343831943,97 6,32,857,197,5
2F-21501253761853,666,62,377,496,8
2F-31571302471873,16,92,257,2to 97.1
2G-18754157482,715,01,367,398,8
2G-28153121782,166,01,087,696,6
2G3 7967162682,325,81,107,598,1
2N-12721713612501,18,63,248,5a 94.2
2N-22031583102460,78,32,658,593,2
21-12151603742320,49,03,118,597,2
2I-2192140413219 0,48,93,318,596,8
2J-1573217100,94,20,638,495,4
2K-1140101279980,358,72,158,798,7
L2-12041484252172,97,42,727,396,8
L2-21581251382102,67,21,307,496,7
2M-1766270501,64,61,037,498,0
2M-2795977541,67,21,107,496,8
2N-1755959471,64,61,087,496,7
2N-2665161491,64,00,757,397,0

SampleAbC water (cm3/100 is) The oil absorption (cm3/100g)Specific surface area BET (m2/g)The specific surface BECOMING (m2/g)Na2SO4(%)H2O (%)Put the amount of Hg (ml/g)5% pHWhite (Technidyne)
20-1138101166832,395,82,356,498,5
2P-1675649292,06,50,887,4of 97.8
2Q-1615124161,55,50,718,097,6
2R1 595439211,74,80,667,897,9
2S-1826195381,925,01,227,6of 97.8

Were also evaluated particle size distribution of particles typical batches of particles of silicon dioxide, obtained by the continuous process disclosed here. The results are presented in Table 6. The coefficient of uniformity (Cu) is defined as D60/D10. The coefficient of the curve of the particle size distribution (SS) is defined as (D30/(D10× D60)). The symmetry of the peak is defined as (D90-D50)/(D50-D10), where the magnitude of the symmetry of the peak equal to 1.0, will fit absolutely symmetrical distribution.

Table 6
Properties granulometries the th particle distribution
SampleUniformity coefficientThe coefficient of the curve of the particle size distributionThe peak symmetry
2B-22,470,231,48
2B-32,370,261,60
2C-22,330,261,60
2C-32,430,291,35
2E-22,220,301,43
2F-21,980,23the 1.44
2F-32,200,24the 1.44

Images obtained with a scanning electron microscope, products of silicon dioxide prepared as part of the continuous process disclosed in this document, prodemo is there much more spherical and homogeneous distribution compared to the standard silicon dioxide. The level of sphericity/roundness was significantly higher in the case of products with a low structure, because they did not glomeruli so easily after drying. As increasing the level structure levels of sphericity/roundness and homogeneity of the particles decreased. When comparing products of silicon dioxide, obtained using the continuous loop process, the products produced using traditional periodic way, you can easily see the difference in their sphericity and roundness. Images obtained with a scanning electron microscope, products of silicon dioxide with low, medium and medium-high structure, synthesized by means of a continuous loop reactor, and the products derived from the traditional periodic ways, shown in Fig. 3-6.

Also studied the change to the level shift passed in to the system using the built-in mixer SILVERSON. Regulation of input power from 30 to 60 Hz and remove the stator from the built-in mixer SILVERSON essentially had no effect on the quality of sphericity and roundness of the obtained particles. The average number of passages, however, correlated with sphericity and roundness of the particles. Samples 2P, 2Q and 2R were obtained in the same conditions, except that he changed the rate of recycling (and the average number of passes). It was found that the style 2R, with the highest average number of passes (71) has the high sphericity and roundness of particles compared with samples 2P and 2Q.

Example 4

Particles of silicon dioxide, obtained with different acidifying agents

(i) 4A

Preparing a solution consisting of 1.5 kg ZEODENT 103, 1.34 kg of sodium sulfate, 11,1 l of sodium silicate (2,65 MR, 13,3%) in 20 l of water. Then approximately 15.5 l of this solution was added to the recirculation loop loop reactor described in Example 1 and then heated to a temperature of 50°C. the Contents were recycled with a speed of 78 l/min with a built-in mixer SILVERSON in the recirculation loop, operating at 60 Hz (3485 rpm). Sodium silicate (2,65 MR, 13.3%) and carbon dioxide (99,9%) was added into the loop simultaneously with the feeding speed of the silicate 0.5 l/min and feed rate of carbon dioxide sufficient to maintain the pH of 9.3 (approximate consumption was 47 l/min). If necessary, the flow of carbon dioxide was regulated to maintain the pH. Carbon dioxide and silicate were added under these conditions for 40 minutes to blow the unwanted silicon dioxide from the system before collecting the required material. After 40 minutes, the collection was drained and its contents were unloaded. Carbon dioxide and silicate were added continuously, and the product of silicon dioxide was collected in a container with AC is sevanam with a speed of 40 rpm, at the same time maintaining a temperature of approximately 50°C. After it was collected the required amount of product, the supply of carbon dioxide and silicate was stopped. The contents of the loop were left to circulate. The pH value of the product of silicon dioxide in the collection was brought to 6.0 by adding manually sulfuric acid, then filtered, washed until the conductivity of approximately 1500 µs, dried and crushed, if necessary.

(ii) 4B

Example 4B was carried out in accordance with the method of Example 4A, except that the sodium silicate contained 10 wt.% sodium sulfate, the pH was maintained at 8.5 with an approximate flow rate of carbon dioxide 64 l/min

(iii) 4C

Preparing a solution consisting of 1.5 kg ZEODENT 103, 1.34 kg of sodium sulfate, 11,1 l of sodium silicate (2,65 MR, 13,3%) in 20 l of water. Then approximately 15.5 l of this solution was added to the recirculation loop loop reactor and then heated to a temperature of 43°C. the Contents were recycled at 80 l/min with a built-in mixer SILVERSON in the recirculation loop, operating at 60 Hz (3485 rpm). Sodium silicate (2,65 MR, 13.3%) and sulfuric acid (11.4%) of containing the sodium sulfate with a concentration of 23 g/l, was added in the loop simultaneously with the feeding speed of silicate of 2.55 l/min and feed rate of acid sufficient to maintain the pH of 7,5. When neo is the divergence of the feed rate of the acid was adjusted accordingly to maintain the pH. Acid (containing sodium sulfate and silicate were added under these conditions for 40 minutes to blow the unwanted silicon dioxide from the system before collecting the required material. After 40 minutes, the collection was drained and its contents were unloaded. Acid (containing sodium sulfate) was added continuously until the product is silicon dioxide was collected in a container with stirring at a speed of 40 rpm, at the same time maintaining the temperature of about 45°C. After it was collected the required amount of product, the supply of acid and silicate was stopped. The contents of the loop were left to circulate. Product of silicon dioxide in the collection then filtered and washed until the conductivity of approximately 1500 µs. Before spray drying, the pH is brought to pH 6.0 by adding manually sulphuric acid.

(iv) 4D

Example 4D was carried out in accordance with Example 4, except that the feed rate of the silicate was 1.7 l/min, the pH value was maintained at a level of 7.1, the reaction temperature was 95°C. and the temperature in the collection maintained at about 90°C.

(v) 4E

Example 4 was carried out in accordance with Example 5D, except that the concentration of silicate was 19.5%, used 17% sulfuric acid containing aluminum sulfate with a concentration of 8.5 g/l, the reaction temperature sostavlyala°C, and the pH value was maintained at 7.5.

Table 5
Physical properties of samples of silicon dioxide, obtained in Example 4
ExampleAbC water (cm3/100 g)The oil absorption (cm3/100 g)Specific surface area BET (m2/g)The specific surface BECOMING (m2/g)Na2O4(%)H2O (%)Put the amount of Hg (ml/g)5% PHThe median particle size (microns)White (Technidyne)
4A-1761341931945,68,41,147,76,5of 99.1
4B-1771281619- ---6,4-
4C-21551214241864,0of 5.42,027,15,8to 97.1
4D-1816094452,0a 4.90,787,67,697,4
4E-21191043581643,66,51,287,5the 5.7of 97.8

In addition to sulfuric acid in a continuous loop reactor to obtain a precipitated silicon dioxide can be used additives and other acidifying agents. In examples 4A and 4B as acidifying AG the NTA instead of sulfuric acid used carbon dioxide. This was carried out by gas flow in a continuous loop reactor through a SILVERSON mixer. In the above examples used a smaller feed rate of silicate (0.5 l/min) to ensure that the supplied carbon dioxide sufficient time for the reaction and maintain the desired pH level, because the flow of carbon dioxide was limited. As carbon dioxide produces a weak acid (carbonic acid), used a pH above 8.5. Products of silicon dioxide, obtained in Example 4A, had a high sphericity and roundness that was observed using images (SEM). To obtain a median particle size in the range of 5 to 7 μm did not need grinding using Raymond mill or air flow. In Examples 4C, 4D and 4E as the acidifying agent used a mixture of an aqueous solution of sodium sulfate and sulfuric acid, the physical properties are presented in Table 7.

Example 5

Composition means to care for teeth

Preparing compositions of funds for the care of teeth, including expandable particles of silicon dioxide. Evaluated a number of important properties of the products of silicon dioxide used in the compositions of the means to care for teeth. Size of abrasive wear on Airliner for example particles of silicon dioxide, obtained using the disclosed continuous process, were mean is Ino lower than expected, in the range from 1.8 to 8.1 mg loss/100,000 revolutions. In the case of a standard precipitated product of silicon dioxide with decreasing structure size Airliner usually increase. In the case of products of silicon dioxide is disclosed a continuous process such trends were not observed. The magnitude of Airliner was in accordance with the particle size. Size of abrasive wear Plexiglas to study examples of products of silicon dioxide were also significantly lower than expected, ranging from 3.3 to 8.7.

Values of transmittance (%T) ranged from approximately 20 to 80% when tested 4% sorbitol. The values of refractive index (RI), larger than 1,439 was observed for all the samples. The increase in RI compared to conventional precipitated products of silicon dioxide were probably due to the lower reaction temperatures. The RDA values powders four samples were in the range from approximately 105 to 221, according to test results using the method Hefferren. This test was performed using the dental school of the University of Indiana.

It was also found that a continuous process is useful for producing products of silicon dioxide, is compatible with cationic ingredients such as cetip is redini chloride (CPC). The CDS is a cationic antimicrobial agent used in the compositions of mouthwash for mouth to reduce the formation of dental plaque, Tartar and gum disease. Standard materials of silicon dioxide is usually incompatible with ALS due to the strong interaction between the cationic portion of the molecule CDS and negatively charged surface of the silicon dioxide. To improve the compatibility of the silica with the CDS can be obtained from products of silicon dioxide is very low structure with a reduced free surface for binding with ALS. Getting compatible with CDS products of silicon dioxide using standard periodic processes can be problematic, because to achieve the necessary structures, usually takes more time, and the grinding of such silicon dioxide of high density can lead to low levels of whiteness. Using the disclosed continuous process allows to obtain products of silicon dioxide low structure with good performance and very good brightness level, because to achieve the desired range of particle size is not required grinding with a hammer or air flow. A summary of the tests silicate dental gel are presented in Table 8.

Abrasive and optical data products of silicon dioxide, obtained using the continuous process
SampleAirliner (mg loss/100,000 revolutions)Abrasive wear Plexiglas (loss of gloss)RDA powderRI (at a maximum %T)%T (4% sorbitol)
2A-12,5the 3.82211,44858,8
2B-12,94,5-1,444of 56.4
2B-23,2-1691,43948,2
2B-34,5--1,43946,0
2K-13,5 7,0-1,43964,0
2C-15,25,2-1,43964,4
2D-13,37,8-1,43922,8
2D-3of 5.4--1,43524,4
2E-11,8a 3.91301,43920,0
2E-33,0--1,43526,0
2S-1the 4.78,7-1,43942,8
2F-16,0-- 1,45370,3
2F-24,3-1051,44760,2
2F-34,1--1,44755,8
4C-12,1--1,45380,6

SampleAirliner (mg loss/100,000 revolutions)Abrasive wear Plexiglas (loss of gloss)RDA powderRI (at a maximum %T)%T (4% sorbitol)
4C-23,6--1,45372,3
4C-33,6--1,45373,0
4C-14,2--1,44446,2
20-1a 3.9--1,44470,4
2G-11,8--1,43956,1
2G-22,2--1,43954,2
2G-3the 3.8--1,43954,5
4A-13,6--1,43945,8
2L-12,3----
2L-22,8 ----
2M-15,8----
2M-26,2----
2N-17,5----
2N-27,0----
2J-17,9----
2P-17,1--
2Q-18,1--
2R-15,6--

For the introduction of the toothpaste to test for PCR, RDA and REA (abrasive wear of enamel by radioactive method) chose several samples with structures, covering a range of structures. The samples were put in charge of preparations for the care of teeth with 20% load and at lower load levels, in combination with traditional materials of silicon dioxide. The compositions are presented in Tables 9-12. Some of these samples, as well as a number of other injected in two different compositions for stability evaluation means on care of teeth.

Table 9
Composition toothpaste
ExampleThe series number of songs
5AndInDEFGnI
11,011,011,011,011,011,011,011,011,0
Sorbitol 70,0%40,040,040,040,040,040,040,040,040,0
Deionized water20,020,020,020,020,020,020,020,020,0
CARBOWAX 6003,03,03,03,03,03,03,03,03,0
CEKOL 500 TONS1,21,21,21,21,21,21,21,2
The pyrophosphate is tetranitride0,50,50,50,50,50,50,50,50,5
Saccharin sodium0,20,20,20,20,20,20,20,20,2
Sodium fluoride0,2430,2430,2430,2430,2430,2430,2430,2430,243
Zeodent 1651,51,51,51,51,5 1,51,51,51,5
Zeodent 10320,0-10,0------
Zeodent113-20,010,0---10,010,010,0
2F-2---20,0--10,0--

td align="center" namest="c12" nameend="c14"> 5,0
2B-2----20,0- -10,0-
2E-1-----20,0--10,0
Titanium dioxide0,50,50,50,50,50,50,50,50,5
The sodium lauryl sulfate1,21,21,21,21,21,21,21,21,2
Flavouring flavouring substance0,650,650,650,650,650,650,650,650,65
Only100100100100100100100100100
Table 10
Composition toothpaste
ExampleThe series number of songs
5JToLMN AboutpQ
The glycerine 99,5%11,211,211,211,211,211,211,211,2
Sorbitol 70,0%36,436,436,436,436,436,436,436,4
Deionized water18,818,818,818,818,818,818,8 18,8
CARBOWAX 6003,03,03,03,03,03,03,03,0
CEKOL 20000,30,30,30,30,30,30,30,3
The pyrophosphate is tetranitride0,50,50,50,50,50,50,50,5
Saccharin sodium 0,20,20,20,20,20,20,20,2
Sodium fluoride0,2430,2430,2430,2430,2430,2430,2430,243
Zeodent1657,07,07,07,07,07,07,07,0
Zeodent10320,0-- -------
Zeodent124-20,0------
Zeodent113--20,0-----
2B-2---20,0--- -
2E-1----20,0---
2E-3-----20,0--
2G-1------20,0-
2G-3-- -----20,0
Titanium dioxide0,50,50,50,50,50,50,50,5
Sodium lauryl sulfate1,21,21,21,21,21,21,21,2
Flavouring flavouring substance0,650,650,650,65 0,650,650,650,65
Only100100100100100100100100
Table 7
The composition of toothpaste.
ExampleThe series number of songs
5RSTandVWX
The glycerine 99,5%5,05,05,05,05,05,0
Sorbitol 70,0%57,3657,3657,3657,3657,3657,3657,36
Deionized water11,011,011,011,011,011,011,0
Carbowax 6003,03,03,03,03,03,03,0
Cekol 2000 0,80,80,80,80,80,80,8
Saccharin sodium0,20,20,20,20,20,20,2
Sodium fluoride0,240,240,240,240,240,240,24
Zeodent11320,0----- -
2B-1-20,0-----
2B-2--20,0----

2C-1---20,0---
2C-2----20,0 --
2F-2-----20,0-
4C-2------20,0
1 % solution of blue dye0,20,20,20,20,20,20,2
Sodium lauryl sulfate1,21,21,21,21,21,21,2
Flavouring flavouring substance1,01,01,01,01,01,01,0
Only100100100100100100100
Table 8
Composition toothpaste
ExampleNThe series number of songs
5YZAAABAUADAE
The glycerine 99,5%11,011,011,0 11,011,011,011,0
Sorbitol 70,0%40,040,040,040,040,040,040,0
Deionized water20,020,020,020,020,020,020,0
Carbowax 6003,03,03,03,03,03,03,0
Cekol 500 TONS1,21,21,21,2 1,21,21,2
The pyrophosphate is tetranitride0,50,50,50,50,50,50,5
Saccharin sodium0,20,20,20,20,20,20,2
Sodium fluoride0,2430,2430,2430,2430,2430,2430,243
Zeodent1651,51,51,51,5 1,51,51,5
Zeodent10320,0---...--
Zeodent113---10,015,0--
2G-2-20,0-----
2N-2-----20,015,0
2J-1 --20,010,05,0--
Titanium dioxide0,50,50,50,50,50,50,5
Sodium lauryl sulfate1,21,21,21,21,21,21,2
Flavouring flavouring substance0,650,650,650,650,650,650,65
Only100 100100100100100100

It was found that samples of toothpaste have acceptable aesthetic properties after 6 weeks of incubation at 25°C. after this period of time the value of the availability of fluoride in all cases exceeded 85%. The increase in viscosity products of silicon dioxide, obtained by means of a continuous method of producing silicon dioxide, was similar to silicon dioxide low patterns for all samples except 5W and 5X that were more effective in terms of increasing viscosity than ZEODENT 113.

For a number of products of silicon dioxide was measured value PCR, RDA and REA. For the samples of PCR values ranged from 83 (Example E) to 107 (Example A). At load levels from 10 to 15% of the value of PCR was usually 90-100. The value of RDA funds for the care of teeth ranged from 94 to 315 depending on the structure and the load level of the test silicon dioxide. Example AA, 20% loading of silicon dioxide, obtained in 2J, showed the highest RDA value corresponding to 315. It was a product of silicon dioxide with the lowest structure of all received, and consequently he was the most abrasive. When used in combination with traditional materials of silicon dioxide, such as ZEODENT 113, at load levels in the range from 5 to 10% was observed improvements in cleaning compared using one ZEODENT 113. Were also tested some products of silicon dioxide, obtained using the continuous loop reactor at higher structural levels, it was found that they have a value of PCR similar to the traditional good cleansing materials silicon dioxide (Examples 5 and 5W) and are more effective in terms of increasing the viscosity than the means to care for their teeth, containing 20% load ZEODENT 113 (Example 5). Cleansing properties of products of silicon dioxide with a higher structure, obtained using the continuous loop reactor, characterized by higher values of PCR and RDA than traditional tools for materials of silicon dioxide with a high structure. Products of silicon dioxide Examples and 5W 5X demonstrated bifunctional nature, providing a very good cleaning and at the same time creating a sufficient viscosity increase.

The magnitude of the REA products of silicon dioxide with structures from low to medium, obtained by means of a continuous loop reactor, were below or equal to the magnitude of the REA for ZEODENT 113, indicating that the spherical nature of e which their material may be less abrasive against enamel than the traditional good cleansing materials of silicon dioxide, such as ZEODENT 103.

Table 9
The results of the tests of means on care of teeth for the compositions shown in Tables 7-10
Viscosity after 1 week (JV)Viscosity
after 3 weeks (JV)
Viscosity after 6 weeks (JV)The availability of fluoride in 6 weeks at 25°C (%)
Example25%pHPCRRDAREA
5A-----981567,2
5V---- --5,8
5C-----94129-
5D-----961224,6
5TH-----92133the 4.7
5F-----991745,8
5G----- 88113-
5H-----92125-

tr>
Example25% pHViscosity after 1 week (JV)Viscosity after 3 weeks (JV)Viscosity after 6 weeks (JV)The availability of fluoride in 6 weeks at 25°C (%)PCRRDAREA
5I-----100161-
5J7,531900037000035400093---
To 7,450500060100063100092---
5L7,2997000895000103600091---
5M8,049300053100059100090---
5N7,324100026200030000088---
507,327500029300031900086---
5P7,631700037900038000088---
5Q7,429900031900036200089---
5R6,622200025700026000098---
5S8,2144000156000170000100---
5T8,1currently reported 143,000155000171000100---
5U8,019500020600024200097---
5V8,017500018700019600095---
5W7,628800031700032800093---
5X7,435300038400037000092---
5Y-----100228 -
5Z-----104261-
AA-----107315-
AV-----104290-
5 ° C-------103231-
5AD-----87111-
AE-----8394-

Example 6

Getting silicate of sodium and maniamerica sodium

(i) 6A

Preparing a solution of 1.5 kg ZEODENT 103, 1.34 kg of sodium sulfate, 11,1 l of sodium silicate (3,32 MR, 20,0%) in 20 l of water. Then approximately 15.5 l of this solution was added to the recirculation loop loop reactor described in Example 1 and then heated to a temperature of 60°C. the Contents were recycled at 80 l/min with built-in mixer SILVERSON in the recirculation loop, operating at 60 Hz (3485 rpm). Sodium silicate (3,32 MR, 20.0%) and an aqueous solution of aluminum sulfate (11,4%) was added into the loop at the same time, when the feeding speed of silicate of 1.7 l/min and feed rate of aluminum sulfate sufficient to maintain the pH at 8.5. If necessary, the feed rate of the acid was adjusted accordingly to maintain the pH. The acid and the silicate was added under these conditions for 40 minutes to blow the unwanted silicon dioxide from the system before collecting the required material. After 40 minutes, the collection was drained and its contents were unloaded. Acid and su is that aluminum was added continuously, while the silicate product was collected in a container with stirring at a speed of 40 rpm, at the same time maintaining the temperature at approximately 60°C. After it was collected the required amount of product, the addition of aluminum sulfate and silicate was stopped. The contents of the loop were left to circulate. Then the product of the silicate in the digest was filtered, washed until the conductivity of approximately 1500 µs and dried,

(ii) 6V

Example 6B was carried out in accordance with Example 6A except that the rate of recirculation of 77 l/min, and the reaction temperature was 36°C and in the collection maintained at room temperature. The sample after drying was grinding at the mill Raymond.

(iii) 6S

Example 6 was carried out in accordance with Example 6, except that the apparatus was removed static mixer heat exchanger, and the reaction temperature was 32°C.

(iv) 6D

Example 6D was carried out in accordance with Example 6, except that the concentration of an aqueous solution of aluminum sulfate was 14.5%, feed rate of silicate - 3.4 l/min, and the reaction temperature is 24°C.

(v) 6E

The static mixer heat exchanger is removed from the loop reactor. Preparing a solution consisting of 1.5 kg ZEODENT 103, 1.34 kg of sodium sulfate, 11,1 l of sodium silicate (3,32 MR, 20,0%) in 20 l of water. Priblizitel is but a 15.5 l of this solution was then added to the recirculation loop loop reactor and then heated to a temperature of 39°C. The content was recycled with a speed of 110 l/min with a built-in mixer SILVERSON in the recirculation loop, operating at 60 Hz (3485 rpm). Sodium silicate (3,32 MR, 20,0%), containing magnesium hydroxide at a concentration of 4.5 g/l, and an aqueous solution of aluminum (34,0%) was added into the loop at the same time, when the feeding speed of the silicate 2.5 l/min and a feed rate of the aqueous solution of aluminum sulfate sufficient to maintain the pH to 8.8. If necessary, the feed rate of the aqueous solution of aluminum sulfate was adjusted accordingly to maintain the pH. An aqueous solution of aluminum sulfate and silicate containing magnesium hydroxide, was added in these conditions for up to 25 minutes to blow the unwanted silicon dioxide from the system before collecting the required material. After 25 minutes, the collection was drained and its contents were unloaded. An aqueous solution of aluminum sulfate and silicate containing magnesium hydroxide, was added continuously until the silicate product was collected in a container with stirring at a speed of 40 rpm, at the same time maintaining a temperature of approximately 39°C. After it was collected the required amount of product, the addition of an aqueous solution of aluminum sulfate and silicate containing magnesium hydroxide, stopped. The contents of the loop were left to circulate. The product of silicate in the collection fil is believed, washed to a conductivity of approximately 1500 µs and dried.

Table 10
Physical properties of products of silicon dioxide, obtained in Example 6
ExampleAbC water (cm3/100g)The oil absorption (cm3/100g)Specific surface area BET (m2/g)The specific surface BECOMING (m2/g)Na2SO4(%)H2O (%)Put the amount of Hg (ml/g)5% PHThe average particle size (µm)White (Technidyne)
6A-17968232505,26,51,30the 4.78,897,7
6B-191681981090, 6,50,538,411,799,2
6B-27968180800,17,30,808,4the 5.798,0
6S-19178222930,17,71,167,99,999,3
6C-28360178860,17,41,678,06,6the 98.9
6D-21371222721601,1 8,41,029,66,497,6
6E-1115683691530,310,81,5310,310,798,4
6E-2119682131740,310,20,9610,26,2of 97.8

Examples 6A, 6B, 6C and 6D describe the receipt of silicates of sodium in a continuous loop reactor by neutralizing sodium silicate with an aqueous solution of aluminum sulfate. An aqueous solution of aluminum sulfate was injected into the loop reactor through the in-line mixer SILVERSON. Changing the number of passes used to obtain a range of products, with coefficients of absorption in the range from approximately 60 to 122 cm3/100 g Example 6E describes obtaining maniamerica of by neutralizing sodium silicate NAT is s/magnesium hydroxide with an aqueous solution of aluminum sulfate. The materials obtained in these examples had high values of sphericity and were circular in nature. Materials such as these can be used in paint coatings and in the manufacture of paper.

Various modifications and changes may be made in compounds, composite materials, tools, products, devices, compositions and methods described herein. Other aspects of the compounds, composite materials, tools, products, devices, compositions and methods described herein will be apparent from a consideration of the detailed description and the practical implementation of the compounds, composite materials, tools, products, devices, compositions and methods disclosed herein. This suggests that the detailed description and examples will be considered as illustrative.

1. Particles of silicon dioxide having a coefficient of absorption of up to 100 cm3/100 g, with at least 80% of particles of silicon dioxide have the shape from rounded to rounded, and particles of silicon dioxide have a coefficient of sphericity (S80) more than 0.9, and the amount of abrasive wear on the brass-Airliner less than 8.0 mg loss/100,000 revolutions.

2. Particles of silicon dioxide under item 1, characterized in that the particles of silicon dioxide have a median size of from 3 to 15 μm.

3. Particles of silicon dioxide under item 1, characterized in that the particles of silicon dioxide have a median size of from 3 to 10 microns.

4. Particles of silicon dioxide under item 1, characterized in that the particles of silicon dioxide have a coefficient of absorption of from 30 to 80 cm3/100 g

5. Particles of silicon dioxide under item 1, characterized in that the particle of silicon dioxide has a specific surface according to the method of brunauer-Emmett-Taylor (BET) of from 50 to 350 m2/year

6. The composition of the funds for the care of teeth, comprising particles of silicon dioxide in an amount of 5 to 50% by weight of the composition, where particles of silicon dioxide have a coefficient of absorption of up to 100 cm3/100 g, the coefficient of sphericity (S80) higher than 0.9 and the amount of abrasive wear on the brass-Airliner less than 8.0 mg loss/100,000 revolutions; where at least 80% of particles of silicon dioxide have the shape from rounded to rounded.

7. The composition of the funds for the care of teeth on p. 6, characterized in that the composition comprises one or more water-retaining substance, a solvent, a binder, a therapeutic agent, helatoobrazovatel, thickener other than particles of silicon dioxide, a surfactant, an abrasive, non-particles of silicon dioxide, sweetener, colorant, aromatic and flavoring or preservative.

8. Composition means to care for teeth under item 6, trichomania fact, that particles of silicon dioxide have a median size of from 3 to 15 μm.

9. The composition of the funds for the care of teeth on p. 6, characterized in that the particles of silicon dioxide have a median size of from 3 to 10 microns.

10. The composition of the funds for the care of teeth on p. 6, characterized in that the particles of silicon dioxide have a coefficient of absorption of from 30 to 80 cm3/100 g

11. The composition of the funds for the care of teeth on p. 6, characterized in that the particles of silicon dioxide have a BET specific surface from 50 to 350 m2/year

12. The composition of the funds for the care of teeth on p. 6, characterized in that the composition has an amount of abrasion of dentin by radioactive method (RDA) of at least 100.

13. The composition of the funds for the care of teeth on p. 6, characterized in that the composition has a degree of plaque removal (PCR) at least 85.



 

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2 tbl

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14 cl, 9 ex, 6 dwg

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26 cl, 3 tbl, 3 ex, 1 dwg

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8 ex

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