A method of manufacturing a sizing dispersion, a sizing dispersion and method of sizing paper

 

(57) Abstract:

Methods and dispersion affect the sizing of paper and can be used in the pulp and paper industry. Sizing suspension liquid reactive adhesives are made by dispersing the reactive adhesive in the form of a pure liquid in the dispersion of bentonite or other anionic material containing microparticles in water. These dispersions can be used for sizing in the mass, for example in the paper manufacturing process with retention of microparticles as anionic phase containing microparticles. They can also be used for surface sizing. 3 S. and 19 C.p. f-crystals, 6 PL.

The invention relates to sizing compositions that can be used for paper sizing in the mass or surface sizing of paper, and relates particularly to a method of manufacturing sized paper using these compositions.

Paper, glued in weight, usually made by injecting water emulsion adhesives in the pulp suspension liquefied feedstock, dewatering the suspension on the grid to form a sheet and then drying the sheet. Paper, the use of the substance and drying the sheet. Often the operation surface sizing is combined with the receiving paper, so that the typical method includes obtaining suspensions of the pulp and liquefied feedstock, dewatering suspensions diluted feedstock on the grid to form a sheet, drying the sheet, coating the dried leaf dispersion adhesive and then re-drying the sheet.

Despite the fact that usually are not reactive adhesives, in many cases it is more preferable to use reactive adhesive as an integral part of the adhesive agent, which is introduced into the pulp or applied to the paper, or to use only reactive adhesive as the adhesive agent.

Because reactive adhesives are not water soluble, they before use must be pre-dispersed, i.e. before the introduction of the liquefied feedstock or before application to the sheet. The resulting dispersion (often more accurately called emulsion) should be sufficiently stable so as not to delaminate before use. The formation of a stable emulsion adhesives in water is usually carried out by emulsification adhesive WA, such as cationic starch. It is believed that the use of cationic polyelectrolyte and/or cationic emulsifying surfactant is advantageous, because it is expected that they will enhance substantively adhesives and cellulose fibers, especially when they are used for sizing paper in bulk.

When emulsifying surfactant is used as the sole emulsifier, i.e., without cationic polyelectrolyte, it is usually necessary to use relatively large quantities of emulsifier for the formation of a stable emulsion, usually up to 7 or 8% of the dry weight of the weight of the adhesive. If you enter a cationic polyelectrolyte, then, can be quite a smaller amount of emulsifier, for example, 2%.

Even if the amount of emulsifying surfactant, which is introduced to improve the education of the emulsion, is small, then even this small amount contributes to poor quality sizing and, therefore, has been put forward many proposals to reduce the amount of emulsifying surfactant in the adhesive agent. However, if if it is not possible to obtain suitable results. Thus, despite the negative impact, in the traditional ways, you should always use a significant amount of surface-active additives to enhance the formation of a stable dispersion or emulsion.

It is therefore desirable to obtain a sizing composition that is stable enough to use and which have no such drawback as the need to include significant amounts of emulsifying surface-active additives.

Sizing emulsions are usually made by homogenization of adhesive in water, possibly with the use of long homogenization. If adhesive at room temperature (20oC) is in the solid state, then usually performed by homogenization at an elevated temperature at which the adhesive is in a molten state. As anhydrite adhesives have a tendency to instability, as a rule, you must perform the homogenization and emulsification anhydrite adhesives in the mill. It is desirable to simplify the manufacture of a sizing composition and, in particular, to reduce the amount of homogenization, which is required when the Oleniy, anhydrite adhesive is subjected to hydrolysis in water, a preliminary emulsification and manufacture of the emulsion prior to its use can lead to hydrolysis and the formation of adhesive binders.

If the emulsion includes an introduction dispersion in liquefied feedstock, the undesirable formation of binders because of the danger of contamination of the grid and because of the danger of contamination of other elements of the machine for processing pulp suspension.

If the emulsion adhesive is used as adhesive agent for surface sizing in the manufacture of the sheet, for example, in the sizing press, then usually it is applied heated (for example, above 40oC), and excess emulsion return for re-processing. Therefore, dispersed adhesive is exposed for a long time to hydrolysis at elevated temperatures and very likely is the formation of binders and other undesirable effects of hydrolysis. Probably for this reason, it is usually assumed that anhydrite adhesives are unsuitable for use in the sizing press.

Therefore, preferably the pens the Finance binders during preparation and use of emulsified adhesive.

There is always a need to improve the performance of sizing, which are obtained by using a sizing composition for surface sizing or sizing in mass. In some cases it is desirable to obtain this improvement in the General plan, for example, receiving a superior (i.e. lower) the value of the Cobb. In other cases, it is desirable to obtain improved sizing from the point of view of any particular use. For example, paper, glued on the surface, can be used for ink-jet printing, in which the black color represents a mixing black, which is obtained by ink-jet printing, and then it is desirable to have the maximum optical density for this mixed black. It is also desirable to be able to improve the performance sizing.

Manufacture of paper, taped in the mass or on the surface, necessarily involves performing a significant number of process stages and the introduction of chemical additives and, therefore, it is desirable to combine two of these supplements in one Supplement, which gives approximately equivalent result or, preferably, even better characteristics than those poku traditionally assumed, what cationic sizing composition will be more substantive paper material, especially when it is used for paper sizing in mass. Thus, the traditional is the inclusion of a cationic polyelectrolyte in a sizing composition that is designed for surface sizing or sizing in mass. However, it is known the use of anionic or non-ionic emulsifying surfactants to obtain anionic or nonionic dispersions or emulsions adhesive agent.

In EP-A-499448 describes how to use restraint systems containing microparticles, in which the reactive adhesive is added in the form of a non-ionic or anionic emulsion in the pulp suspension after flocculation of the suspension when adding a cationic retention means. One of the preferred methods of carrying out the method is to obtain the anhydrous emulsion adhesive, or other adhesive substance by emulsification adhesives using anionic and/or nonionic emulsifying surfactant and the introduction of this emulsion dispersion of bentonite or other anionic materialssee. This implies a mandatory pre-emulsification of adhesive. He also has a drawback consisting in the fact that necessarily introduces emulsifying surface-active additive (followed by the possible deterioration of the characteristics of sizing) and the potential exists for hydrolysis of anhydrous adhesive with the formation of sticky deposits.

Disclosure of other ways to use anionic dispersion of reactive adhesives are presented in WO 96/17127 (published after the priority date of this application). Anionic sizing dispersion is prepared by emulsifying a reactive adhesive, preferably an adhesive substance with ketene dimer) in water to form a dispersion and mixing this dispersion with a Sol of colloidal particles of anionic silica modified with aluminum. Thus, this technology includes traditional pre-emulsification of adhesive in water, then mixing the emulsified adhesive with a Sol of silicon dioxide, modified with aluminum. Obviously, the Sol with the unmodified silicon does not provide required was stabismus, what is the resulting suspension in a single sample was stable for weeks. In this example, the suspension is added to the pulp liquefied feedstock, adding cationic starch. Also mentioned that the sizing dispersion may be added before, between, after, or simultaneously with addition of cationic polymers.

Sizing formulations with anionic the ketene dimer is also disclosed in EP - A - 418015. They are made by emulsification of adhesive dimer of ketene, when it is in the molten state, in water in the presence of an anionic dispersant or emulsifier. It is argued that the density of anionic charge emulsified composition can be increased by adding anionactive component, such as anionic polyacrylamide, anionic starch or colloidal silica. These examples show that in a broad sense, the sizing of the mass with the use of anionic compounds gives the results when measuring liquid sensor) are about the same, or in some cases slightly worse than when using cationic compounds. Moreover, the results show that with increasing current measurement liquid sensor sheets, taped anionic composition containing silica, shows significantly higher (worse) than for the corresponding anionic composition that does not contain silica (examples 11 and 13). Other data (example 19) also shows the worst results under the same conditions.

From U.S. patent 5433776 also known education dimer emulsion of ketene with an emulsifier and various cationic materials, including cationic colloidal silica. It also involves significant use of the emulsifier and is too cationic composition.

Many users believe that anhydrite adhesives provide better characteristics than the adhesive agents dimer of ketene, but the disadvantages are the difficulty associated with processing and hydrolysis. It is desirable that they can be reduced or eliminated.

Preferably, in order to introduce reactive adhesive as the adhesive agent for sizing in the mass or surface sizing at lower needs in the presence of emulsifying surfactants and, therefore, potentially improving sizing properties. It is advisable that you wadera made for this technological process, so in order to minimize the number of required places input additives. Preferably, in order to reduce the risk of hydrolysis, especially for anhydrite adhesive and, consequently, reduce the risk of contamination of the adhesive formations during the sizing in the mass and surface sizing, especially when the return water reactive adhesive to re-process. It is desirable to achieve these goals using simple materials and simple mixing apparatus, so that they could be obtained in the mill in the paper manufacturing process without additional complications.

According to the invention is made of a sizing composition of the reactive adhesive, which is in a liquid state at room temperature, using a method which includes dispersing the reactive adhesive in the form of a pure liquid in the dispersion of the anionic material containing microparticles in water.

The resulting dispersion is a new material and includes a sizing dispersion which is a dispersion in water reactive adhesive (preferably ASA or other anhydrite CL is it from the microparticles, which stabilizes the dispersion. Thus, the dispersion may contain little or no contain emulsifying surfactant.

The invention also provides a method of sizing paper comprising receiving a new dispersion and/or the preparation of a sizing dispersion using a method which includes the above-defined process, and the sizing of this paper sizing dispersion.

The invention includes a method of sizing in the mass, in which the paper is glued in mass by introducing dispersion in the pulp suspension liquefied feedstock and then dewatering the suspension on the grid to form a sheet and drying the sheet.

The invention also includes a method of surface sizing, which comprises applying to paper sizing dispersion prepared by a process comprising the above-defined method.

In the manufacture of a sizing dispersion in the presence of anionic material containing microparticles, you can get the right sizing dispersion, using significantly less emulsifier as is required in the case when the same adhesive on the invention allows to eliminate or reduce the amount of emulsifier and, consequently, provides improved performance sizing.

Using the invention it is possible not only to obtain improved physical stability but also improved chemical stability and, consequently, it is possible to obtain a dispersion anhydrite or other adhesive having less tendency to hydrolysis.

Since the dispersion produced according to the invention contain two essential components (adhesive and a material consisting of microparticles, each of which can positively affect the performance of the resulting implementation of the method of manufacturing paper or coated paper, these dispersions allow you to get favorable results when using a single additive, whereas previously required the introduction of two separate additives.

An additional advantage of these dispersions is that despite the fact that they contain little or no contain an emulsifier, they usually can be produced with the expenditure of less energy homogenization than is necessary for the emulsification of the same adhesive in the same water using conventional emulsifier instead of the material containing the and, must have sufficient stability, which is favourable for sizing. Therefore, it should remain essentially homogeneous no significant separation or stratification within the period of time required to perform the normal processing of dispersion between stages of manufacture and use. Typically, for this reason, it should be stable for at least about a quarter of an hour, and often appropriate to retain the dispersion within an hour to two hours, or sometimes longer before it is used and, therefore, it must be stable during this time. Maintaining the dispersion prior to its use is often an advantage. However, this is irrelevant to the dispersion, which must remain stable during prolonged storage (e.g., more than a week) and this is true for most purposes, when it should be stable and not prone to separation or stratification for at least one hour, and preferably at least five hours.

Reactive adhesive, which is used in the invention must be liquid at room temperature, i.e. at 20oC. Therefore, conventional adhesive box is used an adhesive substance, which is adhesive liquid dimer ketone or, preferably, liquid anhydrous adhesive.

Therefore, the adhesive is preferably an adhesive substance on the basis of liquid dimer ketone, such as an adhesive consisting of a dimer of oleoyl ketone or any conventional adhesive based on anhydride, as most of all of these substances are liquid at room temperature. The preferred anhydrous adhesive is an adhesive of alkenyl succinoyl anhydride (ASA).

Adhesive is supplied by the plant manufacturer, essentially, pure or mixed with emulsifying surface-active agent. In the present invention, the amount of surfactant required for the production of stable dispersions for use in the invention may be significantly less than is required in conventional methods. Thus, in the present invention it is possible to use adhesives that come with a smaller amount of emulsifying surfactants than the normal amount, and it is preferable to use adhesives that ship b is to be want to add to streamline the process of formation of a dispersion may then be selected by the operator of the mill.

Despite the opportunity, according to the invention, to include some amount of surfactant in the dispersion, the presence of surfactants increases the cost and leads to technical problems, such as defective bonding, and therefore, the amount of surfactants is maintained at zero or practically possible low level corresponding to the receiving quite stable dispersion.

In practice, the number of surface-active additives, which is introduced into the dispersion, as a rule, considerably lower than that required for the formation of a stable emulsion in the absence of a material consisting of microparticles, using this surfactant or surfactant mixture. In General, the amount of surfactants is less than half the number required for the manufacture of a stable emulsion of this adhesive in the same water in the absence of a material containing microparticles. For example, if (as is generally the case) must be enabled on mangesto-active compounds, in order to produce a stable emulsion of this adhesive in this water, then, according to the invention the amount of surfactant should be less than 2%. Thus, if a surfactant is present, the selected surfactant and its amount is preferably such that a stable emulsion will not be formed using the same adhesive in the same water, if the amount of this surfactant will be in two times, and preferably 3 or 4 times more.

As a rule, the full amount of surfactant below 2% relative to the weight of the adhesive, and preferably, less than 1%, usually less than 0.5%. The best results are usually obtained in the absence of surfactants.

If a surfactant is present, it usually is chosen from nonionic and anionic surfactants. Thus, a sizing dispersion made according to the invention, generally anionic.

Traditionally, usually considered necessary for sizing the mass to apply adhesive in combination with cationic polyelectrolytes substances for gluing in the mass. However, according to the invention, this is not required and, in fact, this may be undesirable. Therefore, it is preferable that the dispersion is essentially not also contained cationic polyelectrolytes such as cationic starch or a synthetic cationic polymer. As a rule, therefore, the amount of cationic polyelectrolyte is zero, although minor amounts, without effect, can be included and, in fact, it may be in small quantities due to the recirculating circuits in the mill. However, such materials should not use.

Generally, if the dispersion has emulsifying or other additives for reactive adhesives, their number should be sufficient for the manufacture of emulsions of the same adhesive in the same water in the absence of a material containing microparticles, and that would be stable in the sense that it remained stable for several hours. In addition, this number should be sufficient for making such emulsions, which polystability, i.e., such that it splits even within five minutes from the start of production.

When dispel the Itza, have in mind that dispersed adhesive, when it is liquid, not emulsified state and is essentially pure, i.e., does not contain large quantities of surfactants, water or other diluent, but is instead, as a rule, essentially pure material, as originally made, and which, in accordance with the prior art prior to the present invention, normally emulsify in water with the use of emulsifying surfactants. If during the manufacture of the dispersion there is some thinner or other additive, it is desirable that it was a substance that does not degrade significantly the properties of this dispersion.

The method includes dispersing the reactive adhesive in the form of pure liquid dispersion in water anionic material containing microparticles. This dispersion in water of the material containing microparticles, usually prepared in advance and, therefore, the preferred method according to the invention includes the manufacture of a dispersion in water of the material containing microparticles, for example, by mixing the material in water and then disperse ways in which the dispersion in water of the material containing microparticles is formed essentially at the same time, when the reactive adhesive is dispersed in this dispersion. Therefore, for example, a material containing microparticles, reactive adhesive and water can be submitted separately in a dispersive installation so as to form essentially simultaneously dispersion in water of the material containing microparticles and the dispersion in water of reactive adhesives. In the invention does not include the ways in which adhesive is first forms a stable dispersion in water, since the invention primarily involves the use of a material containing microparticles, to ensure the stability of the dispersion. Of course, it is possible to combine pure reactive adhesive and water in a single the initial mixture for submission to the dispersing installation into which the anionic material containing microparticles, as water and an adhesive substance, then, do not form a dispersion (in the absence of a material containing microparticles), and reactive adhesive will dispergirujutsja in water only in the presence of material containing microparticles. However, as a rule, it autoenginuity in her reactive adhesive.

The advantage of the invention lies in the fact that there is no need to expend so much energy on homogenization as is usually required in the manufacture of the reactive dispersion adhesive in water using traditional technologies. Therefore, homogenization is not required, but instead is usually sufficient to perform the mixing. Generally, vigorous mixing, such as in a powerful mixing apparatus with knives, within a reasonably short time (for example, less than 10 minutes and often less than 5 or even 2 minutes) is enough to obtain a satisfactory dispersion.

The amount of material containing microparticles in the finished dispersion, typically in the range of 0.03 to 10% by weight of the dispersion, often from 0.5 to 2% or 3%. Despite the fact that it is enough to add an adhesive substance in the dispersion material containing microparticles, when the variance is required, the output content of the material containing microparticles, it turns out that the best results are obtained by adding adhesive dispersion having a higher concentration of material containing microparticles than the output required concentration, and then the dilution resulting from the about up to 5% of the material, containing microparticles, and this dispersion is then diluted with from 2 to 20 times, often about 10 times to obtain the required content of the solid phase.

Water used in a dispersion, preferably a relatively "soft" because it is easier to get a satisfactory sizing dispersion according to the invention in the absence of or essentially in the absence of emulsifier, when the water is soft than when the water is hard. Therefore, when sizing dispersion is produced in the process carried out in the mill with water, which contains substances that have a negative impact, may require the use of more emulsifying surfactants, than in the case when the impregnation dispersion using a different water.

Used water before its use can be treated using ion exchange softening, but particularly preferably precipitating agent in water, which is used for formation of a dispersion of adhesive and material containing microparticles, preferably in water, which is used for formation of a dispersion material containing microparticles, and in which dataminimum, interacts with salts of rigidity and especially ions of polyvalent metals in the water. The precipitating agent is preferably aminocarbonyl acid, such as acetyl diamine tetraoxane acid or nitrile acetic acid, but in another case it may be precipitating agents: any suitable phosphonic acid, hydroxycarboxylic acid or polycarboxylic acid, which are suitable for the deposition of ions of bivalent and trivalent metals such as calcium, magnesium, iron and aluminum.

The amount of adhesive should be selected based on the quality of the paper and the required degree of sizing. Generally this amount is from 0.1 to 10 parts, often from 0.3 to 3 parts per part of dry weight of the anionic material containing particles. Often the amount of adhesive is at least 1.1 parts to one part of the anionic material. The optimum amount of each substance required to obtain a satisfactorily stable sizing dispersion, can be set through experiments. Typically, the dispersion contains from 0.05 to 2%, typically from 0.07 to 0.3 or 0.5% by weight of adhesive and anionic material containing microparticles, each of the education of the variance (and optionally also as a means of restraint, containing microparticles) may be chosen from those of inorganic and organic materials containing microparticles, which are suitable for use as retaining material containing microparticles. It must be anionic and usually have a maximum particle size less than 3 microns, typically less than 1 μm, at least 90% of the weight.

Preferred materials containing microparticles suitable for use in the invention are swellable clay. Therefore, the preferred material containing microparticles is montmorillonite or spectacula swelling clay. Typically, this swelling clay of this type, which is usually referred to in conversation bentonite. Therefore, a material containing microparticles suitable for inclusion in a sizing dispersion made according to the invention may be bentonite or other swelling clay, commonly used in the manufacture of paper, for example, in the method of manufacturing paper with retention of microparticles Hydrocol (company name), which is described in EP - A - 235893 and EP - A - 335575. Such materials when used can be divided into plates or other structures having Mac less.

Swelling clay preferably is activated in the normal way before use, so that was substituted partially or completely ions of calcium, magnesium or other ions of polyvalent metals that are exposed to sodium ions, potassium or other suitable ions. Therefore, the preferred material containing microparticles for use in the invention is activated bentonite of this type that is commonly used in the methods of making paper Hydrocol and others.

Instead of swelling clays may be used in connection with synthetic silicon dioxide, consisting of microparticles. Preferred materials of this type are the silicic acid Sol, the microgels of polysilicates and microgels of polyaluminosilicate, as described in U.S. patent N 4927498; 4954220; 5176891 or 5279807 and use them in the manufacture of paper is registered under the trademark Particol by Dupont and Allied Colloids. The microgels typically have a surface area of from 1200 to 1700 m2/g or more.

Instead of using these microgels can be used silicic acid sols in which silica particles typically have a surface area in the range from 200 dosage microparticles described in U.S. patent N 4388150 and WO 86/05826, and they are registered under the trademark Composil, and other ways of using silicic acid sols described in EP 308752 and registered under the trademark Positek.

Although it is preferable to use an inorganic material containing microparticles, especially swelling clay or silicon-containing material having a surface area from 200 to 1700 m2/g or more, you can also use organic and polymeric materials containing microparticles, as the material containing microparticles, for example, such materials are described in U.S. patent N 5167766 and 5274055 and used in method with retention of microparticles, registered under the trademark Polyflex. The organic polymer particles may have an average size less than 1 μm, often less than 0.5 microns.

The dispersion can be used for sizing in the mass, additional importance is whether glued the paper on the surface, as if glued on the surface, what adhesive - reactive or non-reactive adhesive.

When the dispersion is used for sizing in the mass, a sizing dispersion, which is added to the n higher and therefore, usually, essentially, does not contain a cationic polyelectrolyte, surfactant or other additives, as all described above.

When sizing dispersion is used for surface sizing, often paper taped in weight and more importance, what with an adhesive made sizing in the mass - reactive or non-reactive adhesive. Sizing dispersion may have other components added to it to use it as a dispersion for surface sizing, for example, a viscosity modifier or coating additives, binders and other materials that are common for a particular coating operation, is introduced into the dispersion before application of the dispersion onto the paper. These materials shall be selected so as to avoid destabilization of the dispersion.

When sizing dispersion is used as an agent for sizing in the mass, it is introduced into the liquefied feedstock in any convenient place and, therefore, may be introduced into the concentrated feedstock, which is then diluted. As a rule, it is added to the liquefied raw materials.

Predpochtitelno dispersion delivers partially or fully retaining material, containing microparticles. Ways to hold microparticles, as is well known, include the introduction of polymer retaining means in the liquefied raw materials and then mixing retaining material containing microparticles, liquefied feedstock, typically, after sufficient grinding to break up the flocs formed by adding a means of restraint. Therefore, a sizing dispersion can be used in any of the above methods with the retention of microparticles or described in the above patents.

Thus, the preferred method according to the invention is the manufacture of paper, taped in mass, using the method with holding the microparticles, and it includes the introduction of polymer retaining means in the pulp and liquefied raw material and then mixing in the slurry, aqueous dispersions of reactive adhesives and anionic material containing microparticles, resulting in a material containing microparticles, acts as a retaining material containing microparticles, and then dewatering of the suspension.

In particular, in the preferred method the proposed soderzhashy microparticles including polymeric retention agent and anionic material containing microparticles, and the method includes the supply of pulp suspension containing polymeric retention agent, then mixing this suspension dispersion, which is made water-based and contains anionic material containing microparticles and a liquid reactive adhesive substance, insoluble in water, dewatering the slurry to form a sheet and drying the sheet, and in this way the dispersion in water contains material containing microparticles, and the reactive adhesive and, in fact, contains no emulsifying additives for reactive adhesives.

In such methods, the dispersion can provide all of the required material containing microparticles or more retaining material containing microparticles may be added simultaneously or sequentially.

In preferred methods, the polymeric retention agent is added to the liquefied feedstock, then the liquefied feedstock is subjected to vigorous turbulence or intensive mixing with knives and then added to the dispersion, and optionally other is eposredstvenno before the pressure box or in it. Although this method can be performed using one of the additive polymer means of restraint, often before adding a material containing microparticles are added to two or more different polymers. For example, cationic coagulant may be added first, followed polymer retention tool. The coagulant may be an inorganic material such as alum, or other polyvalent metal inorganic coagulant or it can be a low molecular weight cationic polymer with a great charge.

In these methods, the retaining means is often cationic, but it can be anionic or non-ionic (and may be amphoteric).

If in this way is a separate addition of microparticles that are used for this material containing microparticles may be the same as the material containing particles included in the dispersion, or may be different from this material. This is usually the same material.

Thus, these variants of the invention have a significant advantage, because the same additive is used for sizing in the mass and to retain the microparticles. Moreover, umesto, and the ability to form a sizing dispersion when, essentially, the absence of emulsifier means that can be received improved sizing.

Suggested sizing dispersion can be introduced into the liquefied raw materials (or concentrated feedstock) and various other methods of making paper, for example, in ways that are based on other restraint systems.

For example, they may be added before the polymer retaining means. Therefore, preferable to other proposed methods, a sizing dispersion is added to the liquefied raw materials (or concentrated feedstock), and polymer retention tool (often cationic), essentially, is added, for example, at the recent high point of a knife or after it. Therefore, a sizing dispersion may be added to the centrifuge, and the retaining means after a centrifuge, for example, on the way to the pressure box or in it.

In other ways, the dispersion may be added in the place known use of bentonite or other material containing microparticles. For example, a sizing dispersion can dobavlyaty used during preview processing for liquefied feedstock or a concentrated source of raw materials, to which is then added, essentially, non-ionic polymeric retention agent or cationic polymeric retention agent or anionic polymeric retention agent. Of particular importance is the case when the feedstock is relatively dirty, and the polymer preferably has a low degree of iannotti, for example, 0-10% by weight of an ionic monomer and from 90 to 100% non-ionic monomer, although can be used and more high molecular weight cationic (or anionic) polymers.

In all the previously described proposed methods that include the use of means of restraint, this material may be cationic starch, but is preferably a synthetic high molecular weight polymer, typically having an internal viscosity (IV) about 4 dl/g. Values CENTURIES here measured by suspended level viscometer at 20oC in 1N sodium chloride with a pH of 7. The value of the CENTURIES, usually about 6 or 8 dl/g. When the polymer is cationic, the size of the CENTURIES, usually in the range from 8 to 18 dl/g, but when the polymer is non-ionic or anionic, then the value of the CENTURIES, usually in the range from 10 to 30 dl/g.

When the polymer retaining means, with the broken off from etileno-unsaturated monomers.

Polymeric retention agent usually represents essentially water-soluble polymer formed by polymerization of water-soluble, atilano unsaturated monomer or mixture of monomers. The polymer can be anionic, nonionic, cationic (including amphoteric) and is selected in accordance with established criteria.

Suitable nonionic monomers include acrylamide. Suitable cationic monomers include diallyl dimethyl ammonium chloride and dialkylaminoalkyl (meth)-acrylates and-acrylamide (usually in the form of Quaternary ammonium salts or salts of additional acids). Dimethylaminoethyl acrylate or methacrylate Quaternary ammonium salt are often especially preferred. Suitable anionic monomer include acrylic acid, methacrylic acid, acrylamide-methyl propane sulfonic acid and other carboxyl and sulfonic monomers.

Preferred anionic and cationic polymers are generally copolymers containing from 3 to 70 weight percent (often from 5 to 50) ionic monomer and from 97 to 30 weight percent of acrylamide or other non-ionic monomer.

Vysokomolekulyarnye the use of low molecular weight polymer with high charge density, it is usually a homopolymer with a recurring cationic groups or a copolymer containing at least 80% by weight cationic monomer and from 0 to 20% by weight of acrylamide or other non-ionic monomer. The cationic groups can be obtained by substitution of any of the above cationic monomer. In another case, a low molecular weight cationic polymer can be condensed polymer, such as dicitionary polymer, a polyamine or a polyethylene Imin. Can be used inorganic coagulants such as alum).

Suggested sizing dispersions can also be used in ways in which restraint system contains phenolsulfonate resin with polyethylene oxide. In these methods, a sizing dispersion may be added at any stage of the method and, therefore, it can be added before or after addition of the polyethylene oxide, but usually after phenolsulfonate resin. Suitable methods of this type are described in EP 693146.

Other suitable methods of making paper, which can be applied to the invention described, for example in EP 235893, U.S. patent N 4927498, 4954220, 5176891, 5279807, 5167766, 5274055 and EP 608986 (including the aforementioned patents).

the selfishness and waste paper. It can be without filler or filler and, therefore, may contain any conventional filler. The invention is of particular value when the suspension contains at least 10% of a filler, for example up to 50%.

Preparation of suspension and the details of the method of manufacturing paper may be conventional except for the introduction of adhesive for gluing in the mass and/or surface sizing as described dispersion. As mentioned in the descriptions of the above-mentioned patents, some of these methods are of particular value when the suspension is contaminated, for example, in the result of long-term reuse of white water and/or use of at least 25% mechanical or polymechanics pulp and/or bleached pulp.

The number of retaining polymer is selected on the basis of generally accepted doses and typically is in the range from 0.01 to 0.5%, often from about 0.03 to 0.1% by weight of dry paper. The amount of material containing microparticles, when the method of retention is the retention of microparticles, typically ranges from 0.03 to 3% of the dry weight of paper.

Cladovei other material, containing microparticles is added per ton of dry weight of paper.

If the invention is used in the manufacture of paper surface sizing, the dispersion can be applied to pre-cast the paper into the form of a sizing composition. This paper can normally manufactured and nakativaetsa into a roll, and then be coated with a sizing dispersion obtained according to the invention and containing optionally other additives.

According to the invention are also ways in which surface sizing is part of the method of manufacturing paper in General, in which the glued paper manufactured using the method, including the introduction of polymer retaining means in the pulp and liquefied feedstock, dehydration liquefied feedstock for forming sheet, drying the sheet, application mentioned aqueous dispersion to dry the sheet and re-drying the sheet.

Thus, a sizing dispersion may be added in the usual manner in the usual place on a paper machine. In practice, the paper is usually manufactured on a paper machine, in which the suspension is fed to the grid via the power is entrusted, paper machine typically includes the size press and the dispersion preferably is served at the size press, and the excess dispersion is separated and fed to reuse. Therefore, the proposed invention includes methods in which the excess dispersion is served warm, for example, at a temperature of approximately 40oC on the sheet, and the excess dispersion is removed and sent for reuse.

Because the normal process of making paper is continuous with the repeated use of excessive sizing composition, therefore, a sizing composition for a long time maintained at an elevated temperature. This temperature is usually at least 50oC and can be up to 70-80oC, often about 60oC. These conditions to the present invention resulted in increased hydrolysis of anhydrous adhesive followed by the formation of sticky deposits, but this invention reduces or eliminates the undesirable formation of sticky deposits. Therefore, for the first time, you can use adhesive ASA or anhydrite adhesives in the sizing press, without significant formation of sticky deposits the AB for surface sizing may be applied to the wet sheet, which is then dried, but usually the sheet completely or partially dried before applying the proposed sizing dispersion. Therefore, when the surface sizing is performed during the manufacture of paper on a paper machine, the sheet is usually dried before applying the proposed sizing dispersion for gluing surface, it has a lower moisture content equal to or approximately equal to the moisture content in the environment. Typically the method includes dehydration liquefied feedstock on the grid, pressing, drying completely or partially, the coating dispersion and then re-drying.

When offered a sizing dispersion is used for surface sizing paper usually glued in mass by introducing liquefied feedstock reactive or non-reactive adhesives. Therefore, non-reactive, or other adhesive substance may be entered in the usual way in the liquefied raw materials (including, optionally in concentrated source raw material from which is formed the liquefied feedstock) or gluing in weight can be made according to the invention.

The paper, which taped the use of restraint systems. Therefore, the entire process typically involves the introduction of polymer retaining means in the pulp and liquefied feedstock, dehydration liquefied feedstock for forming sheet, drying the sheet, applying a water dispersion on the sheet and re-drying the sheet. Polymer retention means can be a single material, which is added to improve retention, or several materials can be used as a restraint system. For example, the restraint system may be a system containing microparticles, as described above. If so, then used the retaining material containing microparticles may be the same as the material containing microparticles, which is present in the dispersion applied to the sheet, or other material containing microparticles. This is usually the same material. Therefore, a sizing dispersion designed for surface sizing, it is preferable to use bentonite or other swelling clay as part of a restraint system containing microparticles, as well as material containing microparticles.

Instead of using restraint systems containing microcast is alimera or mnogochasovoj system, containing ionic polymers with opposite charges. Therefore, the method can include adding a cationic polymer retention means, after which the anionic polymer is holding funds or other anionic organic polymer. If required, the method of retention may include pre-processing, such as bentonite or other material containing microparticles, or a low molecular weight cationic polymer or inorganic coagulant. Any of these methods can also be used when performing the methods of sizing in the mass, for example, as indicated above.

The number of ASA or other adhesives in the proposed sizing dispersion, which is used for surface sizing, usually found in the same range as that specified above for sizing in the mass, usually from 0.05 to 5% adhesive and from 0.05 to 10% of the material containing particles, in relation to total weight of the composition. The total weight of the dry coating, applied during surface sizing, i.e. dry weight of adhesive and material containing particles, and any other added material typically ranges from 0.07 g/m2.

When sweeeee after how it was made, essentially, without additives, as described above.

Apparently, the drying, which is carried out after the surface sizing or sizing in the mass, can affect the quality of the sizing according to the invention, it is possible, by placing adhesive material containing microparticles with which it is associated, the variance and for the next fiber paper. Drying may be conducted at ordinary temperatures.

Advantages from using a sizing dispersions for surface sizing is that it is possible to apply a sizing agent with ASA in the ways in which the earlier application was contraindicated due to excessive instability of adhesive ASA. Other advantages arise from the specific of benefits (for example, in determining the sizing for mixed black with ink-jet printing) and benefits from the presence of adhesive surface coating of bentonite or other coating material containing microparticles. This provides the required properties of the coating and by using the present invention it is possible to obtain these advantages, and benefits from the inclusion of ASA or other liquid adhesives.

Gloval with the surfaces of the particles of adhesive reagent, which are formed in the dispersion. For example, a photographic study preferred the proposed formulations (using anhydrous adhesives, as well as bentonite or other swelling clays), fabricated using soft water, show that most or essentially all surfaces of the particles of adhesive reagent are covered and, obviously, the contact plates swelling clay. However, in compositions that are less satisfactory (such as the compositions, which are stable only marginally and were manufactured using hard water and with the insufficient amount of emulsifier to compensate for stiffness), there is a major adhesive surface of the particles of the reagent that are involved in the interaction with the material containing microparticles, but, obviously, without the formation of ties between these surfaces and the material containing microparticles.

We found that whatever the mechanism, there is close contact between the adhesive reagent and material containing particles, in which a simple extraction of the dispersion with an organic solvent can cause the adhesive agent of the variance is not extraverts and, containing microparticles are those that, as was shown when a photographic study (using an optical microscope), in the proposed methods showed the presence of close links between the material containing microparticles, and adhesive reagent. It is unclear what caused this bond: ionic interactions (possibly with groups affected partially hydrolysis on the surfaces of the particles of adhesive reagent) or due to any other physical interaction.

The following examples.

Example 1. Paper manufactured according to the Hydrocol method, as described in EP - A - 234893, by adding an appropriate number (usually from 300 to 800 g/t) water-soluble cationic polymeric retention means with BB about 6 dl/g, followed by grinding in a conventional paper machine and then adding a water dispersion of activated bentonite. Dry weight of the paper was about 165 g/m2.

Adhesive reagent ASA was emulsified in hard water in the presence of 5% (with respect to the adhesive to the substrate) of the emulsifier to obtain a stable emulsion. Then it was added to the dispersion of the bentonite, the amount of the dosage of 3 kg/t (with respect to Sotovaya the water was soft, the Cobb value is 30.

When the method was repeated using pure (without impurities) adhesive reagent containing 1% surfactant, homogenized directly in the bentonite suspension, the corresponding values Cobb were 30 and 27. It was impossible to produce a stable emulsion of the adhesive reagent ASA that contains this amount of emulsifier in the absence of bentonite or in soft water or hard water. Lower values Cobb show the advantage of the proposed method and in hard water or soft water with fewer emulsifier, than it is required for the formation of a stable emulsion adhesive substances in the water.

When this method was repeated using a sticky substance ASA in the complete absence of surface-active additives, it was difficult to obtain a sufficiently stable dispersion material containing microparticles, and adhesive substances in hard water, but in soft water formed a stable dispersion and the magnitude of the Cobb finished paper was 26. This demonstrates an additional advantage, which concludes in the implementation of the method in the absence of emulsifying surfactants.

the tvii 5% emulsifier, the best results are obtained at low or zero amount of surface-active substances.

Example 2. 0.65 parts pure ASA (without emulsifier or other additives) are mixed in a dispersion of 1 part of activated bentonite in 99 parts of water. If the water dispersion of bentonite hard, you can see that the resulting dispersion has a tendency to oiliness. If the water dispersion of bentonite soft, then the resulting dispersion is less oily. If 0.2 part of sodium salt of EDTA is introduced into the water dispersion of the bentonite before dispersion of bentonite, the resulting dispersion containing the adhesive ASA is very homogeneous and stable, and gives the best performance sizing as a reagent for gluing in the mass or surface sizing.

In each of these experiments the mixing is performed by homogenization in a few seconds in the mixer of Silversea.

Example 3. This is an example of a method similar to that discussed in example 1, except that proposed according to the invention the dispersion was made using ASA and 1% of surface-active additives, homogenis 1).

Example 4. The method performed in example 1 was repeated using pure ASA, emulsified in the bentonite suspension at 4%. Were obtained the results shown in table 2.

Example 5. Pure ASA was dispergirovanija in aqueous bentonite, as in example 1.

In the method, A sizing dispersion was podpisyvalisj in cellulosic feedstock from waste, then, essentially, non-ionic polymer after four inversions. In method B was added to the polymer retaining means, the system reserches, and then added sizing dispersion and mixed using four inversions. In method C, a sizing dispersion was added and mixed using four inversions, but holding the tool was not added.

The results are shown in table 3.

Example 6. In this and other examples with bentonite, the bentonite suspension was ground using a mixer of Silvertone with rotating knife at 1200 rpm (rpm), and ASA was introduced into it and within about 30 seconds continued chopping.

This example reproduces the method according to example 1, using the same dispersion made with the participation of surface-active additives and without it. In method C sistergirls in the presence of 1% surfactant. The results are shown in table 4.

Example 7. In this way 5% portion of the dispersion of bentonite was prepared using demineralized water, and pure ASA then mixed with it, as previously, in the absence of emulsifier.

In the secondary raw materials (obtained from waste paper) was added with simultaneous stirring 100 g/t phenolsulfonate resin, then 100 ppm of polyethylene oxide, then a sizing dispersion containing bentonite and ASA.

The results are shown in table 5.

Example 8. 100 ml of a 0.1% suspension of bentonite in water razulybalas using the emulsifier of Silversea. After 5 seconds was added 1 ml of pure adhesive ASA and the resulting dispersion was reserches for another 30 seconds.

This dispersion was applied to the linerboard, which is not covered had a Cobb value of 60 seconds to about 200 gsm when using the scale K N 7. Treated linerboard were dried on a smooth tumble dryer at 60oC for 4 minutes. Next, the sheet was dried in a dryer at 110oC for 30 minutes. After soaking overnight, the magnitude of the Cobb 60 seconds was 20.0 gsm.

Example 9. Pure ASA was mulgirigala in water containing various amounts of the printing/writing, which was previously glued in mass. Surface sizing when applying the proposed sizing dispersion with ASA provide a material suitable for ink-jet printing. Then, it was subjected to evaluation according to the standard Hewlett Packard mixed black and recorded the minimum optical density for each composition. The results are shown in table 6.

From all these examples it is clear that the best sizing results correspond to the lowest values Cobb and that in table 6 the best quality sizing corresponds to the highest values of optical density.

Therefore, various examples show the benefits of sizing according to the invention and that these benefits are maximized when there is no surfactant.

1. A method of manufacturing a sizing dispersion of reactive adhesives, which is in a liquid state at room temperature, comprising a dispersion of a reactive adhesive in the form of pure liquid dispersion in water anionic material containing microparticles.

2. The method according to p. 1, characterized in that the adhesive is rematerial, containing microparticles are selected from swellable clays, Zola silicate, polysilicate and polyaluminosilicate microgels.

4. The method according to p. 1 or 2, characterized in that as the material containing microparticles using bentonite.

5. The method according to any of the preceding paragraphs, characterized in that the water is soft.

6. The method according to any of the preceding paragraphs, characterized in that the dispersion is made essentially in the absence of cationic materials.

7. The method according to any of the preceding paragraphs, characterized in that the dispersion is made essentially in the absence of additives, selected from cationic polyelectrolytes and surfactants.

8. The method according to p. 7, characterized in that the dispersion is produced in the absence of cationic polyelectrolyte and in the absence of emulsifying surfactants or when less than 2% (by weight of the reactive adhesive) surface-active substances.

9. The method according to p. 8, characterized in that the dispersion is produced in the absence of surfactants or when less than 1% of surface-active washes CLASS="ptx2">

10. The method according to any of the preceding paragraphs, characterized in that it includes obtaining a stable dispersion of anionic material containing microparticles, and then infused in her adhesives.

11. The method according to any of the preceding paragraphs, characterized in that the water Omakaitse using ionoobmennoi processing or dispersion is produced in the presence of precipitating agent.

12. Sizing dispersion containing a dispersion in water of a reactive adhesive, which is in a liquid state at room temperature, and the anionic material containing microparticles, which stabilizes the variance, and the variance, essentially, does not contain the cationic polyelectrolyte and contains no surfactants or contains the surface-active agent is less than 2%, preferably less than 1%.

13. The method of sizing paper comprising manufacturing a sizing dispersion under item 12 in relation to the method according to any one of paragraphs.1 - 11 and the sizing of this paper sizing dispersion.

14. The method according to p. 13, characterized in that the paper can be glued in mass by introducing a dispersion in a dilute suspension of pulp raw material, C is audica fact, that includes the introduction of a dilute suspension of pulp raw material polymer means of restraint, then the mixing aqueous dispersions of reactive adhesives and anionic material containing microparticles in a dilute suspension as retaining material containing microparticles, and then dewatering of the suspension.

16. The method according to p. 15, characterized in that the dispersion that is introduced into a dilute suspension of pulp raw material, manufactured in accordance with the method according to any of paragraphs.7 to 9, or a variance under item 12, variance, essentially, contains no additives, selected from cationic polyelectrolytes and surfactants.

17. The method according to p. 14, characterized in that for the manufacture of sized paper from a pulp suspension use restraint system containing microparticles, which contains polymeric retention agent and anionic material containing microparticles, the method includes obtaining pulp suspension containing polymeric retention agent, then mixing this suspension dispersion which is a dispersion in water and contains animania suspension to form a sheet and drying the sheet, the impregnating dispersion in water includes material containing microparticles, and the reactive adhesive and, in fact, contains no additives, selected from cationic polyelectrolytes and surfactants.

18. The method according to p. 14, characterized in that the dispersion is introduced into the pulp slurry, and then added to the polymer retaining means.

19. The method according to p. 14, characterized in that the suspension is injected phenolsulfonate resin, then polietilenoksidnoy resin as a restraint system, and the dispersion is added to the suspension before or after the addition of polyethylene oxide.

20. The method according to p. 13, wherein the surface sizing of paper is performed by applying to the paper of the variance.

21. The method according to p. 20, wherein the viscosity modifier or coating additive is introduced into the dispersion before application of the dispersion onto the paper.

22. The method according to p. 20 or 21, characterized in that for the manufacture of paper surface sizing method includes the introduction of polymer a means of restraint in a dilute suspension of pulp raw materials, dewatering the slurry to form a sheet, drying the sheet, application referred aq is

 

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