Sodium percarbonate particles, method of their production, their application, detergent compositions, containing them

FIELD: chemistry.

SUBSTANCE: invention relates to sodium percarbonate particles. Essence of invention: described are particles of sodium percarbonate, provided with coating and consisting of main particles of sodium percarbonate, surrounded with at least one layer of coating, possessing long storage stability, expressed as amount of released heat at 40°C, measured after 12-week long storage at temperature 40°C, which constitutes less than 5 mcW/g. Subject of invention also are sodium percarbonate particles, provide with coating and consisting of main particles of sodium percarbonate, surrounded with at least, one layer of coating, possessing long storage stability, expressed as preservation of available oxygen content after 8-week long storage at temperature 55°C, which constitutes at least 70%. Also subject of invention are method of said sodium percarbonate particles production and application of said particles in detergent compositions as bleach, and detergent compositions, containing described sodium percarbonate paprticles.

EFFECT: creation of sodium percarbonate particles possessing increased long storage stability.

14 cl, 2 ex, 4 dwg

 

The present invention relates to particles of percarbonate sodium, have higher stability, especially stability during prolonged storage.

It is well known that percarbonate sodium (or bergerat sodium carbonate) is used as a bleach in detergent compositions intended for Laundry or washing dishes at home. Usually, along with other components, such detergent compositions containing zeolite, which is the main detergent component, enzymes, bleach activators and/or odorants. However, as a result of interaction of percarbonate sodium with other components of the composition during storage and transportation is increasing decomposition and, consequently, reducing bleaching ability. It was suggested several solutions to this problem by introducing between percarbonate sodium and its environment the coating layer. For example, in the patent application great Britain GB 1538893 as one of the components of the coating layer is sodium sulfate, and in international application WO 96/14389 - salt of magnesium. In U.S. patent US 4526698 encouraged to use one of the salts of boric acid. The use of such coating layers have helped to increase the stability of the particles percarbonate sodium in detergent compositions. However, to date, have not received such particles is of percarbonate sodium, which would, even after prolonged storage, possessed properties required for their use in detergent compositions as bleach.

The object of the present invention are new particles percarbonate sodium, having increased in comparison with the known particles percarbonate sodium coated, stability during long-term storage, both individually and as part of the product, providing a long period of storage prior to use. The stability of the particles percarbonate sodium during prolonged storage can be expressed in two different ways.

In accordance with the first method it is defined as the amount of released heat at 40°C, measured after storage of 1 g of the product for 12 weeks at 40°C in a sealed vial volume of 3.5 ml measuring the amount of released heat microcalorimeter method based on the sensor bioactivity (LKB2277 Bio Activity Monitor) the principle of heat flow or heat loss. Measured heat flow between the vial with particles of percarbonate sodium coated and water thermostat with temperature, the obtained value is then compared with the value for the reference material with a known amount of heat released during the reaction.

In accordance with the second method, the stability of particles with long-term x is Anenii is expressed as saving the content of available oxygen after storage of 1 g of the product within 8 weeks at a temperature of 55°C in a sealed vial volume of 3.5 ml This value corresponds to the difference between the content of available oxygen before and after storage, expressed as a percentage of the initial content of available oxygen. The content of available oxygen is measured as described below.

Therefore, the present invention relates to particles of percarbonate sodium with stability during prolonged storage, expressed as the amount of released heat at 40°C, measured (as described above) after storage for 12 weeks at 40°C, which is less than 5 μw/year In particular, the amount of released during long-term storage of heat is less than 4 μw/g, preferably less than 3 μw/g, and most preferably less than 2 μw/year

The present invention also relates to particles percarbonate sodium with stability during prolonged storage, expressed as saving the content of available oxygen after storage (as described above), which is at least 70%. Especially if save content of available oxygen is at least 75%, thus the value of at least 80% is very desirable, and the value of at least 85% is preferred.

Particles percarbonate sodium, which is the object of the present invention, can consist, mainly, of percarbonate the three is. They may contain sodium carbonate in amounts that typically does not exceed 15% of the weight of the core particles and/or additives, which usually does not exceed 2 wt.% As a variant, the core particles percarbonate sodium can contain up to 4 wt.% any salt (e.g. sodium chloride), up to 10 wt.% sodium carbonate and up to 4 wt.% additives. These additives may include stabilizers: inorganic (such as alkaline silicates and soluble silicates of alkaline earth metals), organic (such as polycarboxylate or polyphosphonate - as such, in the form of salts, or in acid form, such as polyaminocarboxylic, such as EDTA (EDTA) or DTPA (DTPA), or polyaminopolycarboxylate, as EDTMPA (EDTMPA), CDTMPA (CDMA), DTPMPA (DTPMPA), or hydroalkylation, as hydroxyethylidenediphosphonic) or mixtures thereof.

Particles percarbonate sodium, which is the object of the present invention typically have an average size of at least 300 μm, in particular at least 400 μm, especially at least 500 μm, values of at least 600 microns are particularly favorable. The average particle size typically less than 1600 μm, especially not more than 1400 μm, values of at most 1000 μm are the most common, for example, not more than 900 microns.

The average particle size is measured using a set of sieves (content is the future, at least 6 sit with the known size of the cells), resulting in a gain of separate fractions, each of which are weighed. The average particle size (MPS) in microns calculated by the formula:

where n is the number of sieves (without pallet), mithe weight fraction of the i-th sieve in %, ki- the size of the cells of the i-th sieve μm. The index i increases with increasing mesh size sieves. The pallet has an index of 0 and the size of the cells ko=0 μm, and m0is the weight of the particles remaining on the pallet after sifting. kn+1=1800 μm and the maximum particle size used in the calculation of the average particle size. It has been found that a typical set of sieves, which you can use to obtain reliable results, the following: n=6; k6=1400 μm; k5=1000 μm; k4=850 microns; k3=600 μm; k2=425 μm; k1=150 ám.

The content of available oxygen in the particles percarbonate sodium, which is the object of the present invention is usually at least to 12.0 wt.%, in particular, at least, of 13.0 wt.%, the content of at least 13.5 wt.% is particularly desirable. The content of available oxygen is usually at most 15.0 wt.%, in particular, most of 14.6 wt.%, for example, at the most, 14.0 wt.% The content of available oxygen is measured by titration with permanganate feces what I'm after dissolution in sulfuric acid (see ISO (international organization for standardization) 1917-1982).

The time of dissolution 90% of the particles percarbonate sodium, which is the object of the present invention typically is at least 0,1 min, in particular at least 0.5 to minutes is Usually the time of dissolution 90% of the particles less than 3 minutes, especially at most 2,5 minutes Time of dissolution 90% of the particles represents the time needed to add in water with a temperature of 15°With particles percarbonate sodium coated at a concentration of 2 g/l, the conductivity value of the solution reached 90% of its final value. This method is a modification of the ISO 3123-1976 for industrial perborates, the only difference is in the height of the stirrer, containing 10 mm from the bottom of the chemical beaker having a volume of 2 l (with an inner diameter of 120 mm).

The volume density of particles percarbonate sodium, which is the object of the present invention is typically at least 0.8 g/cm3in particular at least 0.9 g/cm3. Usually this value does not exceed 1.2 g/cm3especially, at most, 1.1 g/cm3. Bulk density is measured as the sample mass in the cylinder of stainless steel with an inner height and diameter of 86.1 mm after falling asleep sample through a funnel (inner diameter in the upper part 108 mm, signicast 40 mm, height 130 mm), placed at a height of 50 mm above the cylinder.

Abrasion particles percarbonate sodium, which is the object of the present invention, measured according to standard method ISO 5937-1980, typically less than 10%, in particular not more than 8%, particularly, is at most 4%. In most cases, the abrasion is at least 0.05 per cent.

In General, particles percarbonate sodium, which is the object of the present invention, absorb moisture, the amount of which is measured during the test, conducted in a humidity chamber at a relative humidity of 80% and a temperature of 32°C for 24 hours, and ranges from 0.1 to 25% by weight of the sample. This value is changed, in particular from 0.5 to 3% by weight of the sample. Under moisture absorption refers to the extent to which, or the speed with which the product absorbs moisture from the environment. The ability to absorb moisture is measured using the following test: a Petri dish with a diameter of 9 cm with a depth of 1 cm is weighed on scales accurate to four decimal places (get the value of W1). In her place a sample of dry percarbonate sodium (about 5 g), gently shake until smooth across the bottom of the Cup layer of particles and weighed again on the same scale (W2). The sample in the Petri dish kept in a room size of about 2.5 m in height, width and length for 4 hours in an atmosphere with a temperature of 32°C, supported by the heater with thermostat, and the relative humidity is 80%created by introducing fine droplets of water in accordance with the indications of moisture, and weighed on the same scales (W3). From the spray drops of the sample to protect the screen. Water absorption is calculated as follows.

Moisture absorption (g/kg)=1000×(W3-W2)/(W2-W1). Under "dry percarbonate sodium" means percarbonate sodium, which was dried to values of moisture content less than 0.3 wt.% (with halogen dryer METTLER HR73, in which the chilled sample weighing about 7.5 g is placed in an aluminum Cup, continuously weighed and subjected to drying at a temperature of 60°C until its weight becomes constant (maximum weight loss of 1 mg 90 seconds). Drying 2 kg of product can be done, for example, in a fluidized bed dryer having a diameter of 15 cm, 15 to 30 minutes at a temperature of from 50 to 90°C. (e.g. 70°C) and air flow rate from 100 to 150 m3/hour. After standing for 24 hours the sample is weighed within 5 min in ambient conditions (temperature 22°C and a relative humidity of 34%).

Typically, the stability of which is the object of the present invention particles of percarbonate sodium in the detergent composition, expressed as the preservation of the content of available oxygen after storage, is, at the ore, 60%, in particular at least 65%. Expressed this way the stability of the particles in the detergent composition is typically at most 95%, particularly at most 85%. The stability of the particles in the detergent composition is defined as follows: detergent composition is prepared by dry mixing 15 wt.% particles percarbonate sodium coated and 90 wt.% the main detergent composition containing zeolite A (Na), called the basis IECA*in an amount of about 35 wt.%. Samples (50 g) prepared mixture is placed in a cardboard box with a plastic coating, sealed and maintained at a temperature of 32°C and relative humidity 80% for 6 weeks. The content of available oxygen is measured before and after a period of storage in the usual way titration with potassium permanganate, the content of available oxygen after a period of storage is expressed as a percentage of the initial content of available oxygen.

Particles percarbonate sodium, which is the object of the present invention, can be both coated and uncoated. Preferably, they are coated. Particles coated represent the core particles surrounded by at least one coating layer. This means that the surface of core particles percarbonate sodium have been processed at least once, by interacting with a substance or mixture of substances p is offset so what layer of the substance or mixture of substances coating was deposited on the surface of core particles. It is desirable that the coating layer was so uniform and homogeneous as possible, and had on the whole surface of the primary particles of homogeneous chemical structure and homogeneous thickness with a minimum of empty space. The coating layer protects the material of the core particles from contact with the environment, particularly from contact with the present in moisture, which accelerates the decomposition of the basic material.

Substance coating that can be used in the framework of the present invention can be an organic or inorganic substance. Inorganic substances coatings are preferred. Inorganic substances of the coating can contain one or more materials selected from the group comprising salts of alkaline and/or alkaline earth metal (in particular sodium or magnesium), formed mineral or other inorganic acids. Typical examples include sulfates, carbonates, bicarbonates, phosphates and/or polyphosphates, silicates, borates and the corresponding boric acid. Specific examples of mixtures of substances of the coating include a carbonate/silicate, boric acid or borate with sulfate and a combination of (a) sulfate, carbonate, carbonate/sulfate, bicarbonate, who priori acid, borate, boric acid/sulfate or borate/sulfate b) silicate. Preferably, the inorganic coating contains sodium silicate, sodium borate, boric acid, sodium carbonate, sodium sulfate, magnesium sulfate, or one of the mixtures of these substances. Substance coating may also be an actual percarbonate sodium, which is applied in the form of a solution of percarbonate sodium or together solutions of sodium carbonate and hydrogen peroxide.

In the case of coating the coating layer, in addition to at least one of the substances of the coating may also contain small particles of percarbonate sodium, with an average size less than 100 microns. The presence of small particles of percarbonate sodium in the coating layer surrounding the core particles percarbonate sodium, is particularly favorable. Indeed, it was found that by introducing small particles percarbonate sodium in the coating layer, the stability of the particles percarbonate sodium with such coverage during prolonged storage prior to use is particularly high. The presence of small particles of percarbonate sodium in the coating layer can be detected by scanning electron microscopy - x-ray spectral analysis based on the method of energy dispersion, which shows the elemental composition of the material of the coating or small chastisement sodium (but not both), as the presence of magnesium or sulfur. The measurements were carried out using the following equipment: FEI Quanta 200, EDX-System company Edax under the following conditions: deep vacuum, 30 kV.

Figure 1 and 2 presents received by the specified method typical images of particles percarbonate sodium coated, which includes small particles of percarbonate sodium. These figures zone 1 corresponds to a layer of the coating, 2 - a small particle of percarbonate sodium in the coating layer, 3 - core particle.

Small particles percarbonate sodium, which may be present in the coating layer have an average size less than 100 μm, in particular less than 90 μm, especially less than 80 microns, and less than 70 microns give good results. Usually the size of a small particle percarbonate sodium is at least 1 μm, especially at least 5 μm, most often, at least 10 μm. Generally, at least 90 wt.% (in particular, at least 95, especially at least 99) small particles percarbonate sodium have a diameter of less than 250 μm, especially less than 220 μm, most preferably less than 200 microns).

May present small particles percarbonate sodium may not have coverage. Alternatively, they can be coated.

The content of small particles percarbonate sodium in the coating layer, as a rule, is, p is at least 1 wt.%, in particular, at least 5 wt.%, value of at least 10 wt.% are preferred value of about 15 wt.% are the most preferred. The specified content is usually at most 40 wt.%, especially at most 30 wt.%, value of at most 20 wt.% are favorable.

The coating layer present on the particles percarbonate sodium, which is the object of the present invention typically is at least 0.1% of the weight of the particles percarbonate sodium coated, in particular at least 0.5% and most preferably at least 1%. The coating layer, in most cases, is at most 50% of the weight of the particles percarbonate sodium coated, especially at most 35%, and most often, at most, 20%. Values from 0.1 to 50 wt.% give good results.

The present invention also relates to a method of manufacturing the above-described particles percarbonate sodium coated. In particular, two below methods yielded very good results.

The first method which is the object of the present invention

In accordance with the first in a special way, which is the object of the present invention, this method includes the following stages:

(a) a stage of manufacture of the basic particles percarbonate sodium

(b) the stage of drying thus obtained is ω fundamental particles of percarbonate sodium

(c) the stage of applying to the thus obtained dried core particles percarbonate sodium coating, which consists in applying at least one solution or suspension of at least one substance coating and small particles percarbonate sodium with an average size of less than 100 μm in order to obtain particles of percarbonate sodium floor,

(d) the stage of drying, the thus obtained particles percarbonate sodium coated.

The first stage (a) manufacture of basic particles percarbonate sodium can be carried out by any known method of manufacture of the basic particles percarbonate sodium. In accordance with the first variant of stage (a) can be a crystallization from a solution in which the sodium carbonate solution is mixed with hydrogen peroxide solution, and the resulting percarbonate sodium precipitated in the form of fundamental particles of percarbonate sodium, for example, by lowering the temperature and/or adding vasilevousa substances. The basic particles percarbonate sodium is separated from the liquid, for example, by centrifugation or filtration. One example implementation of crystallization from solution is described in international application WO 97/35806 company SOLVAY INTEROX.

In accordance with a second embodiment of stage (a) use the method of granulation in the fluidized bed, in which the solution to the of rbonate sodium and hydrogen peroxide solution is sprayed over the bed using a fluidizing gas layer of the seed crystal percarbonate sodium, on the surface where the reaction occurs between sodium carbonate and hydrogen peroxide, resulting in the seed crystals grow and turn into basic particles percarbonate sodium. One example of the implementation of the granulation in the fluidized bed is described in patent GB 1300855 company SOLVAY.

In accordance with a third variant of stage (a) can be a direct way - reaction of hydrogen peroxide solution with a carbonate and/or bicarbonate. One of the examples of direct methods are described in U.S. patent US 6054066 company SOLVAY INTEROX GmbH.

The basic particles percarbonate sodium obtained in accordance with the first embodiment of stage (a) (crystallization from solution)contain, as a rule, more than 1 wt.% water, whereby the water content is usually about 15 wt.% The basic particles percarbonate sodium obtained in accordance with the second option (granulation in the fluidized bed)contain, as a rule, less than 1.5 wt.% water, in particular less than 1 wt.% water, whereby the water content of at most 0.8 wt.% is the most preferred. The basic particles percarbonate sodium obtained in accordance with the third option (direct method)contain, as a rule, from 0.1 to 25 wt.% water.

The water content of the particles percarbonate sodium is measured within nastoyascheevremya, as follows: the sample is heated, and the amount of released moisture is measured by the method described above METTLER.

Stage of drying (b) of the method which is the object of the present invention, may be separate from stage (a)and be done simultaneously with the stage (a) on the same hardware. If stage (a) is carried out in accordance with the first variant (crystallization from a solution), the stage of drying (b) may be carried out in any reactor such as a fluidized bed dryer, drum dryer, conventional oven or an oven with air circulation. The fluidized bed dryer in which the layer main particles percarbonate sodium oijala upward flow of fluidizing gas (such as air, preferably hot air is preferred. Typically, the temperature ranges from 50 to 210°C., especially from 100 to 160°C.

If stage (a) is carried out in accordance with the second option (granulation in the fluidized bed), the drying is usually carried out in the same reactor with a fluidized bed that is used in stage (a). Drying, therefore, coincides with the implementation of stage (a). Usually the temperature of the fluidizing gas is from 50 to 210°C., especially from 100 to 160°C.

If stage (a) is carried out in accordance with the third option (direct method), the sushi is and can be carried out in any reactor, such as drum dryer, conventional oven, oven with air circulation or a fluidized bed dryer, which may be the same as used in stage (a). Usually the temperature of the fluidizing gas is from 50 to 210°C., especially from 100 to 160°C.

The dried core particles percarbonate sodium obtained in stage (b)contain, as a rule, less than 1.5 wt.% water, in particular less than 1 wt.% water, a water content of at most 0.8 wt.% is the most preferred.

Stage coating (C) of the method which is the object of the present invention may be carried out in any suitable way that allows you to bring in a touch of dried core particles percarbonate sodium, a substance coating and small particles percarbonate sodium with an average particle size less than 100 microns. As the equipment for coating can be used mixer of any type or a reactor with a fluidized bed. The mixer is preferred, especially the mixer drum and the rotating tool, such as stirrers LOEDIGE type.

At the stage (C) the substance of the coating can be used in the form of a solution (preferably aqueous solution or in suspension, or in powder form. The use of the substance coating in powder form is described in international application WO 01/6663 company SOLVAY (joint stock company). The use of the substance coating in the form of a solution is preferred, especially preferred in the form of an aqueous solution.

At the stage (s) in the equipment for coating can be in small particles percarbonate sodium in the form of a powder or suspension. The powdered form is preferred. The powder can be added at the same time as the substance coating, or before him, or after him. It is preferable to add a small particle percarbonate sodium at the same time as the substance of the coating. Small particles percarbonate sodium can be filed in the equipment for coating through the same feeder as the substance of the coating, or through a separate feeder. Flow through separate feed device is preferred.

It is desirable that at the stage (C) the moisture content in the system was minimal, which contributes to the binding of the coating layer surface of the core particles and/or the adhesion of small particles to the surface of core particles, or a layer of the coating. Moisture can be present in the core particles percarbonate sodium. It can also be entered as the solvent in the composition of the aqueous solution or suspension of the substance coating or as a solvent in the composition is a suspension of small particles percarbonate sodium or may be an Addendum is as such. If the coating is carried out in the mixer, the moisture content is usually at least 2% of the weight of the dried core particles percarbonate sodium, in particular, at least 3 wt.%, preferably, at least 5 wt.%. The moisture content can reach up to 30% of the weight of the dried core particles percarbonate sodium, especially up to 20%, in most cases up to 15%. If the coating is carried out in a reactor with a fluidized bed, the moisture content may be lower.

Stage (C) of the method which is the object of the present invention can generally be carried out at a temperature at least 20°C. In most cases the temperature is at most 80°C., especially at most 65°C.

In the particular case of the implementation stage (C) the substance of the coating is percarbonate sodium and applied in the reactor with a fluidized bed on the main surface of the particles by spraying solution percarbonate sodium or simultaneous spraying of solutions of sodium carbonate and hydrogen peroxide. At the same time can also be entered small particles percarbonate sodium of less than 100 microns.

Stage of drying (d) of the method which is the object of the present invention may be implemented in any similar to that described for stage drying (b) conditions. If the article is palladium coating (C) is carried out in a reactor with a fluidized bed, the stage of drying (d), preferably, is carried out simultaneously with the stage of coating (s) in the same reactor with a fluidized bed.

Small particles percarbonate sodium used at the stage of coating (C)can be obtained in various ways.

In the first variant, get them separately, as well as particles of percarbonate sodium. In this case, either they are the end product of this process, or can be obtained by screening of the final product to obtain the required average particle size of less than 100 microns.

In the second variant, which is the preferred embodiment of the method, which is the object of the present invention, small particles of percarbonate sodium is obtained by separation of certain particles generated during implementation of the method which is the object of the present invention, and re-directing them to the stage (s).

In the first version the second version of the method which is the object of the present invention may also include, between stages (b) and (C) and/or after stage (d)at least one stage screening with the aim of separating particles of size less than 600 microns and/or more than 1800 μm, followed by grinding the separated particles to particles with an average size of less than 100 microns and their submission to the step (C). Proseware which can be carried out by any known method, for example, using a sieve with a mesh size of 600 or 1800 μm. Sometimes it is more practical to separate particles smaller than 500 μm, in special cases - less than 300 μm. Possible separation of particles larger than 1500 μm, even more than 1200 μm. Grinding can be done on any grinding equipment, such as a rod mill or a jet mill, for example mill ALPINE 400 CW.

In the second version the second version of the small particles percarbonate sodium receiving, selecting (using a filter, cyclone, or a combination of them) fine fraction, carry out the fluidizing gas used in the fluidized bed dryer, and returning them, if necessary after grinding on the stage of coating (s). In accordance with the second version of stage (b) and/or stage (d) is carried out in a fluidized bed dryer using a fluidizing gas, the fine particles are entrained with gas from the dryer and is directed, if necessary - after grinding, the stage (s).

Of course, these two versions of the second variant can be combined.

Moreover, for the method which is the object of the present invention, favorably, the introduction of at least one additional stage of coating between stages (C) and (d). This is especially useful if additional(s) phase(s) of the coating is(are) in the reactor with a fluidized bed of SL is eat.

Especially preferred embodiment of the method, which is the object of the present invention, is presented in figure 3. In the reactor 1 for the manufacture of basic particles percarbonate sodium serves the original carbonate - channel 2 and the original hydrogen peroxide (preferably, an aqueous solution of hydrogen peroxide) is on channel 3. The reactor 1, preferably, is a reactor for crystallization from solution. The obtained core particles percarbonate sodium is supplied from the reactor 1 through channel 4 in the dryer 5, where they are subjected to drying. Thus obtained dried core particles percarbonate sodium serves on the channel 6 in the screen mesh installation 7, and the sieved particles continue to serve on the channel 8 into the reactor for coating 9. Substance coating served in the reactor for coating 9 on channel 10. Small particles percarbonate sodium fed into the reactor for coating 9 on one or more channels 23, 29, 31 and 39. Further, this scheme is described in detail. Particles percarbonate sodium coated out of the reactor for coating 9 on channel 11 and can be served in a fluidized bed dryer 12, which can also be a second reactor for coating, in which the channel 13 is substance coating (the same as in the first reactor for coating, or other). In W is Roy reactor for coating 12 can also be served - the channels 24, 30, 32 and 40 - small particles, as will be described in detail below. Particles percarbonate sodium coated (optional double) then serves to channel 14 in the screen mesh installation 15. Ready, sifted particles percarbonate sodium coating disposed over the channel 16 as a final product.

In the first variant embodiment of the method, which is the object of the present invention, small particles of percarbonate sodium used at the stage of coating, return to the process stage after drying (b), carried out in the dryer 5, as follows. Dryer 5 in this case is a fluidized bed dryer in which the upward flow of fluidizing gas is fed through the channel 17. The fluidizing gas out of the upper part of the dryer 5 channel 18, bringing with them small particles of percarbonate sodium. These particles are separated from the flow coming out of the dryer 5 channel 18, through the separation device 19. The fluidizing gas exits through the channel 20. Separated thus particles serves on channel 21 in the grinding device (optional) 22, which receive particles of average size less than 100 microns. Then the obtained particles serves on channels 23 and/or 24 in the first and/or second reactor for coating 9 and/or 12.

In the second variant embodiment of the method, which is the object of the present izopet the tion, small particles percarbonate sodium used at the stage of coating the return process after screening units 7 and/or 15. In these settings separate particles smaller than 300 μm and more than 1800 μm. Other particles remain in the process and processed as described below. The separated particles (less than 300 μm and more than 1800 μm) served on channels 25 and/or 26 of the grinding device 27 and/or 28, in which the obtained particles with an average size of less than 100 microns. These small particles are served by channels 29, 30, 31 and/or 32 in the first and/or second reactor for coating 9 and/or 12.

In the third variant embodiment of the method, which is the object of the present invention, small particles of percarbonate sodium used at the stage of coating the return process after the stage of drying (d), carried out in the dryer 12, as follows. Dryer 12 in this case is a fluidized bed dryer in which the upward flow of fluidizing gas is fed through the channel 33. The fluidizing gas out of the upper part of the dryer 12 through the channel 34, bringing with them small particles of percarbonate sodium. These particles are separated from the flow coming from the dryer 12 through the channel 34, by means of the separating device 35. The fluidizing gas exits through the channel 36. Separated thus particles serves to channel 37 in the help is inoe device (optional) 38, which receive particles of average size less than 100 microns. Then the obtained particles serves to channels 39 and/or 40 in the first and/or second reactor for coating 9 and/or 12.

First, second and third variants of embodiment of the method, which is the object of the present invention, can be combined.

The second method which is the object of the present invention

In accordance with the second method, which is the object of the present invention, this method includes the following stages:

(a) a stage of manufacture of the basic particles percarbonate sodium

(b) the United stage of drying and applying to the thus obtained core particles percarbonate sodium coating containing at least one solution or suspension of at least one substance coating and small particles percarbonate sodium with an average size of less than 100 μm, carried out in a reactor with a fluidized bed, with the aim of obtaining particles of percarbonate sodium coated.

Stage (a) and (b) can be carried out in the same conditions as described above for the first method, which is the object of the present invention. Similarly can be entered an additional step of coating.

Particularly preferred variant embodiment of the second method, which is the object of the present invention, not only is n in Fig. 4.

In the reactor 1 for the manufacture of basic particles percarbonate sodium serves the original carbonate (preferably, an aqueous solution of sodium carbonate) - channel 2 and the original hydrogen peroxide (preferably, an aqueous solution of hydrogen peroxide) is on channel 3. The reactor 1, preferably, is a reactor for crystallization from solution. The obtained core particles percarbonate sodium is supplied from the reactor 1 through channel 4 in a reactor with a fluidized bed 5, which simultaneously performs the role of a reactor for coating and drying. The fluidizing gas is fed to the reactor 5 through the channel 6. Substance coating served in a reactor with a fluidized bed 5 on channel 7. Small particles percarbonate sodium fed into the reactor with a fluidized bed 5 through one of the channels 16 and 19, as will be described in detail below. The dried particles percarbonate sodium coated divert from the reactor fluidized bed 5 through the channel 8 and is served in the screen mesh installation 9, which are separated too small and too large particles, and particles with an average size of from 300 to 1600 μm is disposed as an end product on channel 10.

In the first variant embodiment of the second method, which is the object of the present invention, small particles of percarbonate sodium used at the stage of coating the return process after this studienakademie coating as follows. The upward stream of fluidizing gas fed into the reactor with a fluidized bed for coating on channel 6. The fluidizing gas out of the upper part of the reactor 5 through the channel 11, bringing with them small particles of percarbonate sodium coated. These particles are separated from the stream exiting the reactor 5 through the channel 11, through the separation device 12. The fluidizing gas exits through the channel 13. Separated thus particles serves to channel 14 in the grinding device 15 which receive particles with an average size of less than 100 microns. Then the obtained particles through the channel 16 is again fed into the reactor for coating 5.

In the second variant embodiment of the second method, which is the object of the present invention, small particles of percarbonate sodium used at the stage of coating the return process after sieve 9. In this setting, the separated particles of size less than 300 microns, and more than 1800 μm. Other particles remain in the process and processed as described below. The separated particles (less than 300 μm and more than 1800 μm) is available on channel 17 in the grinding device 18, where the obtained particles with an average size of less than 100 microns. These small particles serves to channel 19 into the reactor for coating 5.

The first and second variants of embodiment of the method which is the object of us who Otsego of the invention, can be used simultaneously.

Particles percarbonate sodium coated, which is the object of the present invention, can preferably be used as a bleach in detergent compositions.

The present invention therefore relates also to the use of the above described particles percarbonate sodium coated as bleach in detergent compositions.

The present invention also relates to detergent compositions containing the above particles percarbonate sodium coated. They can also contain basic washing component, zeolite or nucerity (such as phosphate detergent components). Other possible components of detergent formulations can be surface-active substances, substances that prevent re-deposition and promotes suspensioni dirt, bleach activators, fluorescent brighteners, soil release agents, agents to control foaming agents, enzymes, fabric softeners, fragrances, colorants and processing AIDS. Liquid detergent composition can be in the form of powders, granules, tablets and liquids. Powders and granules are preferred bulk density of 0.2 to 1.4 g/cm3.

Example 1

The basic particles percarbonate sodium were obtained from a process of continuous crystallization with the use of what Finance NaCl at a concentration of about 200 g/l as vicalvaro substances. Reactor for crystallization was filled with mother liquor to a temperature of from 15 to 25°C. To it was added solid sodium carbonate to the formation of the saturated solution, and 60% (by weight) aqueous solution of hydrogen peroxide in a small excess. The mixture in the reactor was continuously stirred, its temperature was maintained in the range from 15 to 25°C.

The formed core particles percarbonate sodium is continuously taken out from the reactor into the buffer tank and then fed into the centrifuge periodic action. The particles separated in the centrifuge, was dried in the fluidized bed dryer exhaust gas with a temperature of from 50 to 75°C.

3 kg of the thus obtained core particles percarbonate sodium without coating with an average size of 676 μm and a variation 1,16 were separated by sieving, reversible sieve installation IFA-T model MR 24S600-5-5-5 into two fractions, the boundary between which the selected value 600 microns.

The spread of the distribution of particle sizes was measured by means of a set of 6 sieves described above, resulting in several fractions, each of which was suspended. The variance was calculated by the formula:

where n is the number of sieves (excluding the pallet),

mi- weight fraction on sieve i,%,

ki- mesh size sieve i in microns,

the index i increased the correspondingly with the increase of mesh size sieve.

The pallet is in the set of sieves has index 0, the size of the cells k0=0, and m0is the weight of the particles remaining on the pallet after sifting.

kn+1=1800 μm and represents a maximum particle size into account when calculating the scatter.

MPS - average particle size calculated in accordance with the above description.

The fraction with a particle size less than 600 microns was subjected to grinding in an impact mill type Retsch SK100. After grinding, the average particle size was 23 microns with a range of 2.9.

1750 fraction with a particle size greater than 600 μm and 650 g of crushed core particles were placed in a stirrer with lemasney blades and shear head type Lödige with a cutting tool Tour M5 RMK.

There was added 271,4 g of the solution of the substance coating (containing RUB 171.1 g of the solution of the borate-silicate and 100.3 g of water).

The whole mixture was granulated at a speed of rotation of the cutting tool 150 rpm.

The calculated humidity of the mixture was 7%.

The granular product from the mixer was sent to a laboratory reactor with a fluidized bed for coating and drying type Glatt and subjected to drying at a temperature of exhaust gas 85°C.

At the core particles in the fluidized bed was additionally applied by spraying 181,9 g of the same solution of the substance coating.

Conditions in the reactor with pseudohaje the n layer for coating and drying were as follows:

Spray nozzle:spray solution on
the basic particles from top to bottom
Air spray:
pressure:2.5 bar abs.
temperature:90-105°C
consumption:120±10 m3/h
The temperature of the flue gas
when coating:70-80°C
final drying:to 85°C

Upon reaching the exhaust gas temperature of 85°C. the final product was removed from the reactor and cooled.

The total share of the coating was 6 wt.% the weight of the particles percarbonate sodium coated. The coating layer contained 20 wt.% small particles. The obtained particles percarbonate sodium coated possessed long term stability expressed as the number of emitted at 40°C heat, measured after storage of the product for 12 weeks, amounting to not less than 2 μw/g, and expressed as the preservation of content available is of ikorodu after storage of the product for 8 weeks at a temperature of 55°C, amounting to 88%.

Example 2

Repeated the same steps as in the above example, except that the coating was carried out as follows: 2000 faction fundamental particles of percarbonate sodium is larger than 600 microns was mixed with 500 g of crushed in a LOEDIGE mixer (with a cutting tool material and 320 g of a solution of sulphate and sodium silicate (200 g Na2SO4/50 g SiO2/25 g of Na2O/kg). The formed product from the mixer was sent to a laboratory reactor with a fluidized bed for coating and drying type Glatt and subjected to drying. 1500 g of the particles in the fluidized bed was additionally applied by spraying 272,5 g of the same solution of the substance coating. Conditions in the reactor with a fluidized bed for coating and drying were as follows:

Spray nozzle:spray solution on
the basic particles from top to bottom
Air spray:
pressure:2.5 bar abs.
temperature:90-105°C
consumption:120 m3/h
The temperature of the flue gas:
when coating:70-80°C
final drying:to 85°C

The final product contained the coating layer, the proportion of small particles percarbonate sodium which amounted to 25 wt.% (relative to the weight of the coating layer). The proportion of the coating layer in the final product amounted to 5.7 wt.%. The average particle size in the final product was 1036 microns with a range of 0.79. Figure 1 and 2 presents the images of the particles of the final product, obtained with a scanning electron microscope on the basis of the energy dispersion. Explanations for these images have been given above.

1. Particles percarbonate sodium, provided with a coating consisting of core particles percarbonate sodium, surrounded by at least one coating layer with stability during prolonged storage, expressed as the amount of released heat at 40°C, measured after storage for 12 weeks at 40°C, which is less than 5 μw/year

2. Particles percarbonate sodium, provided with a coating consisting of core particles percarbonate sodium, surrounded by at least one coating layer having stable during long is wound, expressed as saving the content of available oxygen after storage for 8 weeks at a temperature of 55°C, which is at least 70%.

3. Particles according to claim 1 or 2, in which the coating layer is from 0.1 to 50 wt.% particles percarbonate sodium coated.

4. Particles according to claim 1 or 2, in which the substance of the coating is selected from the group including sodium silicate, sodium carbonate, sodium sulfate, magnesium sulfate, sodium borate, boric acid and mixtures thereof.

5. Particles according to claim 1 or 2, having an average size of from 300 to 1600 μm, the coating layer which includes at least one substance coating and small particles percarbonate sodium with an average size of less than 100 microns.

6. Method for the production of particles percarbonate sodium according to claim 1 or 2, having an average size of from 300 to 1600 μm, comprising a step for fundamental particles of percarbonate sodium, followed by a stage of application to the core particles percarbonate sodium, at least one of a solution or suspension of at least one substance coating and small particles percarbonate sodium with an average size of less than 100 μm in order to obtain particles of percarbonate sodium coated.

7. The method according to claim 6, including:
(a) a stage of manufacture of the basic particles percarbonate sodium
(b) a stage of drying the thus obtained core particles percarbonate soda is I,
(c) the stage of applying to the thus obtained dried core particles percarbonate sodium coating, which consists in applying at least one solution or suspension of at least one substance coating and small particles percarbonate sodium with an average size of less than 100 μm in order to obtain particles of percarbonate sodium floor,
(d) the stage of drying, the thus obtained particles percarbonate sodium coated.

8. The method according to claim 7, including additionally between stages (b) and (C) and/or (d)at least one stage of sifting to separate particles with size less than 300 μm and/or more than 1800 μm, followed by grinding the separated particles to particles with an average size of less than 100 μm and the return of these small particles to the step (C).

9. The method according to claim 7 or 8, in which between stages (C) and (d) at least one additional stage of the coating in the fluidized bed.

10. The method according to claim 7 or 8, in which stage (b) and/or stage (d) is carried out in a fluidized bed dryer using siraudeau gas, fine particles of percarbonate sodium, submitted fluidizing gas from the dryer fluidized bed, come back, possibly after grinding, the stage (s).

11. The method according to claim 7 or 8, in which stage (a) is carried out by mixing the solution carbó the ATA sodium with hydrogen peroxide solution and deposition of the resulting percarbonate sodium in the form of fundamental particles of percarbonate sodium.

12. The method according to claim 6, including:
(a) a stage of manufacture of the basic particles percarbonate sodium
(b) the United stage of drying and applying to the thus obtained core particles percarbonate sodium coating containing at least one solution or suspension of at least one substance coating and small particles percarbonate sodium with an average size of less than 100 μm, carried out in a reactor with a fluidized bed, with the aim of obtaining particles of percarbonate sodium coated.

13. The use of particles percarbonate sodium according to any one of claims 1 to 5 as a bleach in detergent compositions.

14. Detergent compositions containing particles of percarbonate sodium according to any one of claims 1 to 5.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention refers to sodium percarbonate particles. According to the invention the coated sodium percarbonate particles possessing the inner shell layer including as basic component at least one inorganic hydrate-forming salt and outer shell layer including alkali metal thiosulphate, alkali-earth metal thiosulphate and/or ammonium thiosulphate are described. The method of such sodium percarbonate particles preparation and application of these particles as bleaching agent in detergents and cleansers are also the subjects of an invention.

EFFECT: increasing of stability of sodium percarbonate particles in detergents and cleansers during storage.

23 cl, 4 dwg, 4 tbl

FIELD: chemistry.

SUBSTANCE: invention concerns chemical bleaches applied in cleansers and detergents. Invention claims sodium percarbonate granules with coating of high storage endurance, including a) core obtained by dispersion granulation in pseudoliquefied layer with sodium percarbonate as main component, b) internal coating layer with non-organic hydrate-forming salt as main component, selected out of group including sodium sulfate, sodium carbonate, sodium bicarbonate, magnesium sulfate and mixes or mixed salts of these compounds, and c) outer coating layer with surfactant containing sulfate or sulfonate groups in the form of alkaline metal, alkaline-earth of ammonium salt, as main component.

EFFECT: enhanced storage endurance, high stability and active oxygen content in percarbonate granules.

22 cl, 1 ex

FIELD: technological process.

SUBSTANCE: invention may be used in all fields of engineering, in which application of disinfectant solutions is required, in particular, in medicine, food industry and others. Method of disinfectant preparation includes supply of water solution of alkaline metal carbonate in anode chamber of diaphragm electrochemical cell with cylindrical coaxial electrodes and coaxial ceramic ultra-filtering diaphragm, supply of fresh water in cathode chamber of the same cell and disinfectant drain from anode chamber. Solution of alkaline metal carbonate and water are supplied in anode and cathode chambers of cell with counter-flow. Process is carried out during current conduction via diaphragm mainly with alkaline metal ions. Disinfectant prepared by treatment of water solution of alkaline metal carbonate with concentration of 0.2-2 g/l in anode chamber of electrochemical diaphragm cell with coaxial electrodes and coaxial ultra-filtering ceramic diaphragm, contains peroxide compounds that are in metastable condition and has pH of 6-7.

EFFECT: invention allows to prepare efficient disinfectant that does not contain chlorine, in required quantity at site of consumption with reduction of costs for its manufacturing and usage.

6 cl, 1 dwg, 4 ex

FIELD: chemical industry; production of sodium percarbonate and other chemical products.

SUBSTANCE: the invention is pertaining to the field of chemical industry and may be used in production of sodium percarbonate (SPC) and other chemical products, where the synthesis process is combined with the synthesized product granulation. The granulated sodium percarbonate is produced by the steady growing-up of the products of interaction of the stabilized water solutions of the soda and hydrogen dioxide on the inoculation particles-granules. To chokes give torrents of The streams of the stabilized water solutions of soda and hydrogen dioxide are fed into the reactors at keeping the time of their interaction from 5 up to 21 sec and concentration of the sodium carbonate and the hydrogen dioxide in the ratio of 1 : 1.45-1.57. The produced reaction mass in the form of a solution is fed into the mixers-granulators, where it is distributed along the surface of the inoculation particles of sodium percarbonate, moisten and saturate them within 12-25 seconds up to achieving the average humidity of 6-12 mass %. Then the wet granules are brought out into the drying room on the gas-distributing grate, on which there is a slotted clearance with the gas-feeding channel, formed as a semi-circled groove on the gas-distribution grate and the upper end of the inclined chute. The feeding of the heated flue-gases is exercised under the gas-distribution grate through the gas duct, in which there is an erected septum being the prolongation of the upper wall of the channel and separating up to 6 % of total volume of the fed flue-gases, which are coming in through the channel with adjustment of the speed of their passage through the slotted clearance into the drying room, where they form a gas curtain in the form of the semi-tabernacle, in which the dried granules are classified according to their flying speeds in such a manner, that granules with the diameter less than the preset dimension, for example 500 microns, are carried out by the two equivolumetric streams formed by splitter made in the form of a triangular prism, to the windows and are def into the mixers-granulators as the recycle for a following cycle of granularity, and the granules with the diameter exceeding the preset lower limit, for example - 500 microns and above, fall through the gaseous curtain and on the inclined chute through the outlet window get into the classifier for the final classification according to the high limit of the preset fractionized composition of the final product, for example 800 microns. From the intermediate part of the classifier the granules the preset fraction are delivered for storage. The production output of the granules of the preset fraction, for example, 500-800 microns, is up to 99 %, the bulk weight is 1093-1138 kg/m3, the contents of the active oxygen is - 13.94-14.1 %, stability is 55.91-56.83 %. The invention allows production of sodium percarbonate with the preset range of the composition of the granules without reduction of productivity of the installation.

EFFECT: the invention ensures production of sodium percarbonate with the preset range of the composition of the granules without reduction of productivity of the installation.

9 cl, 2 tbl, 4 dwg

FIELD: chemical industry; methods and devices for production of sodium percarbonate with a stabilizing coating.

SUBSTANCE: the invention is pertinent to the field of chemical industry, in particular, to the method and the device for production of sodium percarbonate with a stabilizing coating and may be used in the production of the oxygen-containing bleaches made on the basis of sodium percarbonate (SPC), which is also applied as a component of synthetic washing agents (SWA). The initial solutions of hydrogen peroxide and sodium are brought in contact with the recycle made in the form of the SPC granules in the mixer, dry in the boiling layer in the driers, a part of the granules are fed into the classifier for separation by the granules size for separation of the granules of the target fraction, the remaining part of the granules are directed back in the mixer in the capacity of the recycle. The target fraction of the SPC granules is in series collected in the storage containers and subjected to vacuumization. Simultaneously the stabilizing agent is subjected to the vacuumization in the measuring containers. The so treated SPC granules and the solution of the stabilizing agent are brought in contact in the additional mixer first at the residual pressure of no more than 25 kPa with the following heighten of the pressure up to no less than 95 kPa or to the atmospheric pressure and dry in the additional drying machine of the boiling layer. At that the finish product stability achieves to 66.0-72.0 %, consumption of the coating material - to 0.9-2.8 weight/weight %, the contents of the active oxygen - 13.8-14.1 mass %. The technical result is the increased stability of the granulated sodium percarbonate with the stabilizing coating.

EFFECT: the invention ensures the increased stability of the granulated sodium percarbonate with the stabilizing coating.

8 cl, 2 tbl, 2 dwg

FIELD: chemical industry.

SUBSTANCE: proposed method includes delivery of aqueous solution of hydrogen peroxide and soda from reservoirs of 1 and 2 to reactor 3. Reaction mass thus obtained is delivered to double-screw mixer 6 communicated with drier 7. Part of dried granules is returned from drier 7 to mixer 6 and other part is directed to classifier 8; fraction at size of particles from 0.1 to 1.00 mm is directed from intermediate part of said classifier to storage reservoir 9 for target fraction granules. Then, granules are fed to vacuum drier in the scope of no more than 50% of its inner volume. Solution preparation unit 37 is used for preparation of aqueous solution of stabilizing agent- sodium, sodium sulfate, sodium carbonate, sodium silicate or their mixtures. Concentration of stabilizing agent solution is 5-15 mass-% and volume is 0.215-0.235 of volume of granules. Vacuum drier 11 and measuring reservoir 10 are evacuated simultaneously to residual pressure not exceeding 13.33 kPa. Granules are evacuated at heating to 55°C and are mixed with stabilizing agent solution first in vacuum followed by jumpwise rise of pressure to atmospheric level or to excessive pressure of 10 kPa; procedure is continued for 0.5-1.0 min. Then vacuum drying is performed at constant or periodic mixing. Moisture content of finished product doe not exceed 1.05% at stability of 59.93-65.74%.

EFFECT: enhanced efficiency.

12 cl, 1 dwg, 1 tbl

FIELD: food industry; production of oxygen-containing bleaching agents and synthetic detergents.

SUBSTANCE: the invention is intended for a chemical industry and may be used at production of oxygen-containing bleaching agents and synthetic detergents. The method provides, that solid particles of the paroxysmal are exposed to vacuumizing at a residual pressure of no more than 13.33 kPa, mainly at 0.67÷8.5 kPa with simultaneous heating up to 55°C, up to 40÷50° C. Then it is treated with a noble gas at atmospheric or excessive pressure of no more than 10 kPa. The mass share of active oxygen (in mass %) is no less than 14.00, stability of the finished product is no less than 59,92 %.

EFFECT: the invention ensures a high stability of alkali metals peroxisalts.

4 cl, 1 dwg, 1 tbl

FIELD: chemical industry; a method and a device of alkali metals peroxysalts stabilization.

SUBSTANCE: the invention is intended for a chemical industry and may be used at production of oxygen-containing bleaching agents and synthetic detergents. In the vacuum drier 3 supplied with a rake-type rabble 10 and a weight-measuring device 12, the main original material is supplied from a reserve tank 1. Then it is vacuumized simultaneously with the solution of a coating material located in a measuring container 17, connected by lines 21, 22 and 13 with the device of a dryer 3 vacuumizing. Then mix the main original material with the solute of the coating material at a residual pressure of no more than 13.33 kPa. Increase the pressure in the vacuum drier 3 up to the atmospheric pressure or exceeding it by no more than 10 kPa spasmodically by an air supply from a source 28. The produced product is exposed to a vacuum drying up to the required moisture, making control of the moisture content by a change of the weight of the dryer 3 contents with the help of the weight-measuring device 12. Stability of the finished product is 59.0-69.0 %, consumption of the coating material - 0.9-1.8 mass %, the share of the active oxygen - 13.8-14.4 mass %.

EFFECT: the invention ensures production of oxygen-containing bleaching agents and synthetic detergents.

10 cl, 1 dwg, 2 tbl

FIELD: chemical industry.

SUBSTANCE: the invention is intended for a chemical industry and may be used in production of bleaching agents and washing agent, household chemical goods. The reactor (1) is fed with soda ash, for example in the form of a solution, through sleeves(5) and a link (7) and hydrogen peroxide solution through a link (6). The sleeves (5)allow to move the reactor (1) along the auger of the mixer (2). Humid granules of sodium percarbonate produced in the mixer (2) are removed through a connecting pipe (9) into a dryer (3) supplied with a gas-distributing lattice (10). One part of the dried granules through a connecting pipe (8) is fed back into the mixer (2), and other part through link (15) is fed into the qualifier (4). A commercial fraction of sodium percarbonate is removed through link (16) into a pneumatic classifier (20). The fine fraction through link (22) and through the cyclone separator (13) and link (14) is fed back into the mixer. The coarse fractions of sodium percarbonate from the qualifier (4) is fed through link (17) into the grinding machine (18). Crushed sodium percarbonate is mixed with the fine fractions and through the cyclone separator (13) and through link (14) is fed back into the mixer (2). The invention allows to decrease the share of a dust faction down to 0.10 - 0.63 % and losses at drying, to increase the share of active oxygen up to 13.91-14.01 % and stability of the finished product.

EFFECT: the invention ensures reduction of the share of a dust faction up to 0.10 - 0.63 % and losses at drying, an increase of the share of active oxygen up to 13.91-14.01 % and stability of the finished product.

4 cl, 1 dwg, 1 tbl

The invention relates to the chemical industry, in particular to household chemicals, and can be used in the manufacture of percarbonate sodium and other chemical products, where the process of synthesis is combined with granulation synthesized product

FIELD: chemical industry.

SUBSTANCE: the invention is intended for a chemical industry and may be used in production of bleaching agents and washing agent, household chemical goods. The reactor (1) is fed with soda ash, for example in the form of a solution, through sleeves(5) and a link (7) and hydrogen peroxide solution through a link (6). The sleeves (5)allow to move the reactor (1) along the auger of the mixer (2). Humid granules of sodium percarbonate produced in the mixer (2) are removed through a connecting pipe (9) into a dryer (3) supplied with a gas-distributing lattice (10). One part of the dried granules through a connecting pipe (8) is fed back into the mixer (2), and other part through link (15) is fed into the qualifier (4). A commercial fraction of sodium percarbonate is removed through link (16) into a pneumatic classifier (20). The fine fraction through link (22) and through the cyclone separator (13) and link (14) is fed back into the mixer. The coarse fractions of sodium percarbonate from the qualifier (4) is fed through link (17) into the grinding machine (18). Crushed sodium percarbonate is mixed with the fine fractions and through the cyclone separator (13) and through link (14) is fed back into the mixer (2). The invention allows to decrease the share of a dust faction down to 0.10 - 0.63 % and losses at drying, to increase the share of active oxygen up to 13.91-14.01 % and stability of the finished product.

EFFECT: the invention ensures reduction of the share of a dust faction up to 0.10 - 0.63 % and losses at drying, an increase of the share of active oxygen up to 13.91-14.01 % and stability of the finished product.

4 cl, 1 dwg, 1 tbl

FIELD: chemical industry; a method and a device of alkali metals peroxysalts stabilization.

SUBSTANCE: the invention is intended for a chemical industry and may be used at production of oxygen-containing bleaching agents and synthetic detergents. In the vacuum drier 3 supplied with a rake-type rabble 10 and a weight-measuring device 12, the main original material is supplied from a reserve tank 1. Then it is vacuumized simultaneously with the solution of a coating material located in a measuring container 17, connected by lines 21, 22 and 13 with the device of a dryer 3 vacuumizing. Then mix the main original material with the solute of the coating material at a residual pressure of no more than 13.33 kPa. Increase the pressure in the vacuum drier 3 up to the atmospheric pressure or exceeding it by no more than 10 kPa spasmodically by an air supply from a source 28. The produced product is exposed to a vacuum drying up to the required moisture, making control of the moisture content by a change of the weight of the dryer 3 contents with the help of the weight-measuring device 12. Stability of the finished product is 59.0-69.0 %, consumption of the coating material - 0.9-1.8 mass %, the share of the active oxygen - 13.8-14.4 mass %.

EFFECT: the invention ensures production of oxygen-containing bleaching agents and synthetic detergents.

10 cl, 1 dwg, 2 tbl

FIELD: food industry; production of oxygen-containing bleaching agents and synthetic detergents.

SUBSTANCE: the invention is intended for a chemical industry and may be used at production of oxygen-containing bleaching agents and synthetic detergents. The method provides, that solid particles of the paroxysmal are exposed to vacuumizing at a residual pressure of no more than 13.33 kPa, mainly at 0.67÷8.5 kPa with simultaneous heating up to 55°C, up to 40÷50° C. Then it is treated with a noble gas at atmospheric or excessive pressure of no more than 10 kPa. The mass share of active oxygen (in mass %) is no less than 14.00, stability of the finished product is no less than 59,92 %.

EFFECT: the invention ensures a high stability of alkali metals peroxisalts.

4 cl, 1 dwg, 1 tbl

FIELD: chemical industry.

SUBSTANCE: proposed method includes delivery of aqueous solution of hydrogen peroxide and soda from reservoirs of 1 and 2 to reactor 3. Reaction mass thus obtained is delivered to double-screw mixer 6 communicated with drier 7. Part of dried granules is returned from drier 7 to mixer 6 and other part is directed to classifier 8; fraction at size of particles from 0.1 to 1.00 mm is directed from intermediate part of said classifier to storage reservoir 9 for target fraction granules. Then, granules are fed to vacuum drier in the scope of no more than 50% of its inner volume. Solution preparation unit 37 is used for preparation of aqueous solution of stabilizing agent- sodium, sodium sulfate, sodium carbonate, sodium silicate or their mixtures. Concentration of stabilizing agent solution is 5-15 mass-% and volume is 0.215-0.235 of volume of granules. Vacuum drier 11 and measuring reservoir 10 are evacuated simultaneously to residual pressure not exceeding 13.33 kPa. Granules are evacuated at heating to 55°C and are mixed with stabilizing agent solution first in vacuum followed by jumpwise rise of pressure to atmospheric level or to excessive pressure of 10 kPa; procedure is continued for 0.5-1.0 min. Then vacuum drying is performed at constant or periodic mixing. Moisture content of finished product doe not exceed 1.05% at stability of 59.93-65.74%.

EFFECT: enhanced efficiency.

12 cl, 1 dwg, 1 tbl

FIELD: chemical industry; methods and devices for production of sodium percarbonate with a stabilizing coating.

SUBSTANCE: the invention is pertinent to the field of chemical industry, in particular, to the method and the device for production of sodium percarbonate with a stabilizing coating and may be used in the production of the oxygen-containing bleaches made on the basis of sodium percarbonate (SPC), which is also applied as a component of synthetic washing agents (SWA). The initial solutions of hydrogen peroxide and sodium are brought in contact with the recycle made in the form of the SPC granules in the mixer, dry in the boiling layer in the driers, a part of the granules are fed into the classifier for separation by the granules size for separation of the granules of the target fraction, the remaining part of the granules are directed back in the mixer in the capacity of the recycle. The target fraction of the SPC granules is in series collected in the storage containers and subjected to vacuumization. Simultaneously the stabilizing agent is subjected to the vacuumization in the measuring containers. The so treated SPC granules and the solution of the stabilizing agent are brought in contact in the additional mixer first at the residual pressure of no more than 25 kPa with the following heighten of the pressure up to no less than 95 kPa or to the atmospheric pressure and dry in the additional drying machine of the boiling layer. At that the finish product stability achieves to 66.0-72.0 %, consumption of the coating material - to 0.9-2.8 weight/weight %, the contents of the active oxygen - 13.8-14.1 mass %. The technical result is the increased stability of the granulated sodium percarbonate with the stabilizing coating.

EFFECT: the invention ensures the increased stability of the granulated sodium percarbonate with the stabilizing coating.

8 cl, 2 tbl, 2 dwg

FIELD: chemical industry; production of sodium percarbonate and other chemical products.

SUBSTANCE: the invention is pertaining to the field of chemical industry and may be used in production of sodium percarbonate (SPC) and other chemical products, where the synthesis process is combined with the synthesized product granulation. The granulated sodium percarbonate is produced by the steady growing-up of the products of interaction of the stabilized water solutions of the soda and hydrogen dioxide on the inoculation particles-granules. To chokes give torrents of The streams of the stabilized water solutions of soda and hydrogen dioxide are fed into the reactors at keeping the time of their interaction from 5 up to 21 sec and concentration of the sodium carbonate and the hydrogen dioxide in the ratio of 1 : 1.45-1.57. The produced reaction mass in the form of a solution is fed into the mixers-granulators, where it is distributed along the surface of the inoculation particles of sodium percarbonate, moisten and saturate them within 12-25 seconds up to achieving the average humidity of 6-12 mass %. Then the wet granules are brought out into the drying room on the gas-distributing grate, on which there is a slotted clearance with the gas-feeding channel, formed as a semi-circled groove on the gas-distribution grate and the upper end of the inclined chute. The feeding of the heated flue-gases is exercised under the gas-distribution grate through the gas duct, in which there is an erected septum being the prolongation of the upper wall of the channel and separating up to 6 % of total volume of the fed flue-gases, which are coming in through the channel with adjustment of the speed of their passage through the slotted clearance into the drying room, where they form a gas curtain in the form of the semi-tabernacle, in which the dried granules are classified according to their flying speeds in such a manner, that granules with the diameter less than the preset dimension, for example 500 microns, are carried out by the two equivolumetric streams formed by splitter made in the form of a triangular prism, to the windows and are def into the mixers-granulators as the recycle for a following cycle of granularity, and the granules with the diameter exceeding the preset lower limit, for example - 500 microns and above, fall through the gaseous curtain and on the inclined chute through the outlet window get into the classifier for the final classification according to the high limit of the preset fractionized composition of the final product, for example 800 microns. From the intermediate part of the classifier the granules the preset fraction are delivered for storage. The production output of the granules of the preset fraction, for example, 500-800 microns, is up to 99 %, the bulk weight is 1093-1138 kg/m3, the contents of the active oxygen is - 13.94-14.1 %, stability is 55.91-56.83 %. The invention allows production of sodium percarbonate with the preset range of the composition of the granules without reduction of productivity of the installation.

EFFECT: the invention ensures production of sodium percarbonate with the preset range of the composition of the granules without reduction of productivity of the installation.

9 cl, 2 tbl, 4 dwg

FIELD: technological process.

SUBSTANCE: invention may be used in all fields of engineering, in which application of disinfectant solutions is required, in particular, in medicine, food industry and others. Method of disinfectant preparation includes supply of water solution of alkaline metal carbonate in anode chamber of diaphragm electrochemical cell with cylindrical coaxial electrodes and coaxial ceramic ultra-filtering diaphragm, supply of fresh water in cathode chamber of the same cell and disinfectant drain from anode chamber. Solution of alkaline metal carbonate and water are supplied in anode and cathode chambers of cell with counter-flow. Process is carried out during current conduction via diaphragm mainly with alkaline metal ions. Disinfectant prepared by treatment of water solution of alkaline metal carbonate with concentration of 0.2-2 g/l in anode chamber of electrochemical diaphragm cell with coaxial electrodes and coaxial ultra-filtering ceramic diaphragm, contains peroxide compounds that are in metastable condition and has pH of 6-7.

EFFECT: invention allows to prepare efficient disinfectant that does not contain chlorine, in required quantity at site of consumption with reduction of costs for its manufacturing and usage.

6 cl, 1 dwg, 4 ex

FIELD: chemistry.

SUBSTANCE: invention concerns chemical bleaches applied in cleansers and detergents. Invention claims sodium percarbonate granules with coating of high storage endurance, including a) core obtained by dispersion granulation in pseudoliquefied layer with sodium percarbonate as main component, b) internal coating layer with non-organic hydrate-forming salt as main component, selected out of group including sodium sulfate, sodium carbonate, sodium bicarbonate, magnesium sulfate and mixes or mixed salts of these compounds, and c) outer coating layer with surfactant containing sulfate or sulfonate groups in the form of alkaline metal, alkaline-earth of ammonium salt, as main component.

EFFECT: enhanced storage endurance, high stability and active oxygen content in percarbonate granules.

22 cl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention refers to sodium percarbonate particles. According to the invention the coated sodium percarbonate particles possessing the inner shell layer including as basic component at least one inorganic hydrate-forming salt and outer shell layer including alkali metal thiosulphate, alkali-earth metal thiosulphate and/or ammonium thiosulphate are described. The method of such sodium percarbonate particles preparation and application of these particles as bleaching agent in detergents and cleansers are also the subjects of an invention.

EFFECT: increasing of stability of sodium percarbonate particles in detergents and cleansers during storage.

23 cl, 4 dwg, 4 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to sodium percarbonate particles. Essence of invention: described are particles of sodium percarbonate, provided with coating and consisting of main particles of sodium percarbonate, surrounded with at least one layer of coating, possessing long storage stability, expressed as amount of released heat at 40°C, measured after 12-week long storage at temperature 40°C, which constitutes less than 5 mcW/g. Subject of invention also are sodium percarbonate particles, provide with coating and consisting of main particles of sodium percarbonate, surrounded with at least, one layer of coating, possessing long storage stability, expressed as preservation of available oxygen content after 8-week long storage at temperature 55°C, which constitutes at least 70%. Also subject of invention are method of said sodium percarbonate particles production and application of said particles in detergent compositions as bleach, and detergent compositions, containing described sodium percarbonate paprticles.

EFFECT: creation of sodium percarbonate particles possessing increased long storage stability.

14 cl, 2 ex, 4 dwg

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