Paper and cardboard manufacture method

FIELD: pulp-and-paper industry, in particular, manufacture of paper and cardboard.

SUBSTANCE: method involves preparing aqueous cellulose pulp; adding holding system into cellulose pulp system; draining pulp through cloth for forming of paper web; drying resultant paper web. Holding system comprises swelling clay having whiteness of at least 70.

EFFECT: increased whiteness of paper and improved filler retention capability.

16 cl, 1 tbl, 20 ex

 

The present invention relates to the manufacture of paper or paperboard according to the method, including the preparation of an aqueous cellulosic suspension, adding to this pulp suspension system retention, draining the suspension on the grid forming the paper web and drying of this paper, the implementation of which the retention system includes a swelling clay. Methods of making paper of this type is well represented in the literature and include, for example, the Hydrocol method (trademark), which provides for the application of bentonite (i.e. anionic swelling clay) as part of the retention system. Such methods are described, for example, in EP-A 235893, US 4913775 and EP-A 707673.

In EP-A 235893 proposed method, the implementation of which is at the stage of shear effects in the fiber for making paper introduced a water-soluble, essentially linear cationic polymer, and then re-flocculation after this stage, the shear effects of the addition of bentonite. The implementation of this method provides enhanced drainage, and good formation and retention. This method, which has found industrial applications due to the company Ciba Specialty Chemicals under the trademark Hydrocol®confirms its effectiveness for over a decade.

It was found that the istemi for the manufacture of paper, in which as part of the retention system used swelling clay, usually provide a significant speed improvement of drainage and retention. Typically, swelling clays include bentonite, sepiolites, attapulgite etc. Bentonites include the General class of clays known as smectites, which include clays such varieties as montmorillonite, saponite, amargosa, nontronite and hectorite. In many cases, the retention system, which include swelling clays, provide a much improved drainage and retention compared even with such other systems of particles, which are used, for example, colloidal silicon dioxide and polysilicon acid.

However, a special problem is holding on the basis of clays is that the paper made with their use suffers from the deterioration in optical properties. Although the inclusion of optical brighteners (Ootb) in the paper manufacturing process, which uses bentonite, can improve the whiteness of paper, often this improvement is insignificant and insufficient for making the most of high quality paper products such as paper with a high degree of whiteness, white indices on Acbp (Association of the pulp and paper industry) over 92, preferably in the range of the 96 to 99 or above. Thus, in order to ensure these high performance white paper retention system on the basis of swelling clays generally considered as unacceptable and, therefore, their applications are avoided.

In WO-A 98/23815 describes an attempt to solve this problem by combining optical Brightener with a suspension of anionic bridging coagulant, such as bentonite, and then infused the combination in a fibrous pulp for making paper. Although using this method has made significant improvements in the degree of whiteness of paper is still there, as was established, the need for even greater increase in whiteness, especially basic white.

When using the system of retention on the basis of clays for the manufacture of paper with only moderate white, optical brighteners (Ootb) must, apparently, be used in high concentrations. However, it was found that during the processes of production of highly filled paper the presence of optical brighteners in high concentrations can have a deteriorating effect on the retention of filler.

While we have made various attempts to improve the efficiency of optical brighteners, still did not create any effective optical Brightener, which can be used compatible with the but with retention on the basis of swelling clays.

Thus, there is still a need to develop ways of improving the whiteness of the paper or cardboard when using the retention system on the basis of swelling clays (e.g. bentonite). Thus, in particular, there is a need to develop a method of making paper, which combines the advantages of high filler contents and retention of fibers and fast drainage, for example, as observed when using systems of retention on the basis of swelling clays, getting paper with high whiteness, especially when using reduced amounts of optical brighteners.

In addition, there is also a need in the manufacture of paper filled with a high degree of whiteness and improved filler retention.

Thus, in accordance with the present invention features a method of making paper or paperboard, including the preparation of an aqueous cellulosic suspension, adding to this pulp suspension system retention, draining the suspension on the grid forming the paper web and drying of this paper, characterized in that the retention system includes a swelling clay, whiteness index which Acbp is at least 70.

Thus, it was found that the overall degree of whiteness of the paper can be the t can be improved by the use of swelling clays with white on Acbp at least 70. As swelling clays can be used, for example, bentonites, sepiolites, attapulgite etc. provided that these clays are white on Acbp at least 70. Bentonites include clay of the General class known as smectites, which include clays such varieties as montmorillonite, saponite, amargosa, nontronite and hectorite. Preferred swellable clay is bentonite.

Test white on Acbp is a standard test method to determine, for example, white fibrous pulp, paper and cardboard, but it can also be applied to swelling clays, such as bentonite. Specific details of this method see, for example, in published Acbp standard test method T 452 on-92 from 1992, entitled Brigtness of pulp, paper and paperboard (direct reflection at a wavelength of 457 nm).

It was found that the swelling clays, such as bentonites, which contain small or minor amounts of impurities of transition metals, peculiar manifestation of white indices on Acbp at least 70. Thus, in particular, when creating the present invention, it was found that white bentonites inherent content of less than 1% impurities of transition metals, which can be, for example, oxides or other connection is through the iron. And Vice versa, as determined by the creation of the present invention, bentonites, which contain much more than 1 wt.% transition metals have white indices significantly below 70. This is especially true for bentonites, which contain up to 10% impurities of transition metals, especially when the impurities include iron oxides or other compounds of iron.

As swelling clays can be used any number of technically available clays which exhibit whiteness index on Acbp at least 70. Swelling clay may represent, for example, sodium bentonite, comprising less than 1% of compounds of transition metals and showing the whiteness index for Acbp 81, which is produced at the plant in Waverly place units GA, USA.

In accordance with all the objects of the invention serves, in addition, a method of manufacturing paper or paperboard, including

the preparation of an aqueous cellulosic suspension, adding to this pulp suspension system retention, draining the suspension on the grid forming the paper web and drying of this paper,

characterized in that the retention system includes a swelling clay, which contains less than 1 wt.% one or more transition metal compounds.

In accordance with both objects, the image is placed swelling clay can be used in combination with other retaining additives as part of a multicomponent system retention. For example, according to one preferred variant of the system, a system of making paper, which further includes a retaining polymer additive. Polymer retention additive can be entered in the pulp suspension simultaneously with the swelling clay, although in the preferred embodiment, the polymeric retention additive and swelling clay is injected sequentially. In a preferred embodiment of the present invention retaining polymer additive is introduced into the cellulosic suspension before the swelling clay. In the preferred method of retaining polymer additive is introduced into the pulp slurry, thereby flocculating the cellulosic suspension, and does not affect the suspension of the shear impact transmission flocculated slurry through one or more shear stages of exposure to selected stages of pumping, mixing and cleaning, followed by the addition of swelling clay to re-flocculation of the pulp suspension. Funds shear processing include, for example, centrifugal pumps and centrifugal sorting, but they could be any other tools used in the process, in which the influence of the shear force.

Stage effects on flocculated suspension shear force required ASU is estolate thus, to break the flakes. Before stage shear effects you can add all the components floculants system, although in the preferred embodiment, at least the last component floculants system is introduced into the pulp slurry at the point of the technological process, after which the drainage from the forming paper web any significant shear effect is absent. Therefore, in a preferred embodiment, the pulp suspension add at least one component floculants system, and then flocculated suspension is subjected to a mechanical shearing treatment, during which the flakes are mechanically destroy, then add at least one component floculants system for re-flocculation of the suspension before drainage.

Polymer retention additive can be derivatisation from any acceptable natural or synthetic polymers. In a suitable embodiment, they may be selected from water-soluble natural polymers and water-soluble synthetic polymers with a characteristic viscosity of at least 1 DL/g Polymer retaining the additive can be, for example, water-soluble starch is selected from cationic starch, amphoteric starch, anionic starch and non-starch is. However, in the preferred embodiment, the polymeric restraint Supplement is synthetic and includes high-molecular polymer, which by nature is ionic. More preferred water-soluble cationic synthetic polymer obtained from one or more ethylene-unsaturated monomers and having a characteristic viscosity at least 4 DL/g

Water-soluble synthetic polymer can be obtained from water-soluble ethylene-unsaturated monomers. Under the water-soluble mean that the monomer has a solubility in water of at least 5 g/100 tubes When the polymer is ionic, it is obtained from at least one water-soluble ionic monomer. Water-soluble polymer may be non-ionic and, thus, received from one or more nonionic monomers such as acrylamide, methacrylamide, 2-hydroxyethylacrylate or N-vinylpyrrolidone. Water-soluble anionic polymers can be obtained from at least one anionic monomer selected from acrylic acid, methacrylic acid and 2-acrylamide-2-methylpropanesulfonic acid. Suitable water-soluble polymeric retention additive is a cationic polymer which may be the floor of the Chan of water soluble ethylene-unsaturated cationic monomer or mixture of monomers, moreover, at least one of the monomers in the mixture is cationic or potentially cationic. In a preferred embodiment, the cationic monomer is selected from diallyldimethylammoniumchloride, acid additive salts and Quaternary ammonium salts or dialkylaminoalkyl(meth)acrylate, or dialkylaminoalkyl(meth)acrylamides. The cationic monomer may be polymerized alone or copolymerization with water-soluble nonionic, katiana active or anionic monomers. Preferred such polymers have characteristic viscosity of at least 3 DL/g, for example, reaching 16 or 18 DL/g, but is usually in the range from 7 or 8 to 14 or 15 DL/g are Particularly preferred cationic polymers include copolymers methylchloride Quaternary ammonium salts dimethylaminoethylacrylate or methacrylate.

Water-soluble cationic polymer may also have a slightly branched structure, which is achieved, for example, the introduction of small quantities of agent education branches, in particular up to 20 miscast./million As a rule, the agents of education branches include any of the agents of education branches, which in this description is defined as acceptable for obtaining a branched anionic polymer. the hat branched polymers can also be obtained by the inclusion in the monomer mixture control degree of polymerization. Control degree of polymerization can be included in the amount of at least 2 miscast./million and can be used up to 200 miscast./million As a rule the content of the control degree of polymerization is in the range from 10 to 50 miscast./million as a regulator of the degree of polymerization can be used any acceptable chemical substance, such as hypophosphite sodium, 2-mercaptoethanol, malic acid or thioglycolate acid. Branched polymers, including the regulator polymerization degree can be obtained with the use of increased quantities of agent education branches, for example up to 100 or 200 miscast./million, assuming the number of control degrees of polymerization are sufficient to guarantee the water solubility of the resulting polymer. Branched cationic water-soluble polymer, as a rule, can be obtained from the water-soluble monomer mixture comprising at least one cationic monomer, at least 10 molar ppm million regulator polymerization degree and less than 20 molar ppm million agent education branches. In a preferred embodiment, the branched water-soluble cationic polymer is characterized by a rheological oscillation value of tan Delta at 0.005 Hz more 07 (determined by the method, in the present description). Branched cationic polymers generally have a characteristic viscosity of at least 3 DL/g As a rule, these polymers may have a characteristic viscosity in the range from 4 or 5 to 18 or 19 DL/g is Preferred polymers have characteristic viscosity in the range from 7 or 8 to about 12 or 13 DL/g

Polymer retention additive can also be an amphoteric polymer in the sense that it includes both anionic and cationic groups. Thus, the amphoteric polymer may be derived from at least one cationic monomer and at least one anionic monomer, and an optional nonionic monomer. Therefore, the amphoteric polymer can be derivative from any of the above anionic, cationic, and an optional nonionic monomers.

Water-soluble polymer retention additives can also be obtained by any convenient method, for example by polymerization in solution, the polymerization in suspension of water in the oil or by polymerization in emulsion of water in oil. In the polymerization in solution form aqueous polymer gels, which in the dried state can be cut and grind with obtaining a powdery product. These polymer may be obtained in the form of a bead suspension polymerization or emulsion polymerization in emulsion of water in oil product in the emulsion or dispersion of water in oil, for example, in accordance with the method presented in EP-A 150933, EP-A 102760 or EP-A 126528.

For the preferred process of making paper proposes a method, in which the cationic polymer is introduced into the cellulosic suspension before retaining polymer additives. In one embodiment, the method cationic polymer that is injected before retaining polymer additive is a low molecular weight cationic coagulant. In a preferred embodiment, the cationic polymer is chosen from the group including polydadmac (polydiallyldimethyl), polyimid, polyamine and dicyandiamide polymers.

A method of manufacturing paper may also include the use of optical Brightener. The optical Brightener may be entered directly in the pulp slurry or alternatively, together with component retention system, for example with swelling clay or polymer retention additive.

The optical Brightener may be deposited on the surface of the formed paper web in the form of a coating pigment. The composition of the coating pigment includes, for example, one or more fillers or pigments, fluorescent optical Brightener (OSF), a binding agent, a rheology modifier, and optionally other chemical agent is. The filler or pigment is usually a white inorganic powder material and may be selected, for example, from the group including calcium carbonate, preferably precipitated calcium carbonate or ground calcium carbonate, kaolin, titanium dioxide and talc. Typically, the amount of filler or pigment is at least 75%, often at least 85 wt.%, in terms of the composition of the coating pigment.

Fluorescent optical brighteners (OSF), also known as optical brighteners (Ootb), increase reflective ability and, thus, the whiteness of the coated sheet. Binder type for fixing the pigment on the paper or paperboard coated, it usually is an adhesive polymeric material in the form of an aqueous latex. The rheological properties of the composition coating pigment typically regulate, so that it was acceptable for this specific purpose.

When performing the present invention an optical bleach (Ootb) or fluorescent optical Brightener (OSF) may be any chemical substance with fluorescent properties, are able to absorb radiation from the ultraviolet part of the spectrum and emit radiation in the visible part of the spectrum. In a preferred embodiment, free the private bleach is stilinovic fluorescent optical Brightener, such as described in GB-A 2026566 and GB-A 2026054, or bastilleday fluorescent optical Brightener, such as described in EP-A 624687. To fluorescent optical brighteners are derivatives diaminodiphenylsulfone acid, tetraaminoanthraquinone acid and its derivatives, tetraaminoanthraquinone acid and its derivatives, as well as tetraaminoanthraquinone acid and its derivatives. In a preferred embodiment, the fluorescent optical brighteners are prepared in the form of water of a concentrated suspension, usually a concentration of at least 30 wt.%, in particular about 60 wt.%.

In another embodiment, the present invention its objects are paper and cardboard, which may be made in accordance with the invention method.

In yet another embodiment of the present invention, its object is a composition comprising a swelling clay with white on Acbp at least 70, and retaining polymer additive. This swelling clay and retaining additive possess such properties, as shown above.

In the preferred embodiment, this composition it is a composition in which the swellable clay is bentonite.

In yet another embodiment, the present image is etenia its object is the use of swelling clay, with white on Acbp at least 70, for manufacturing paper or paperboard.

In another embodiment, the present invention its object is the use of the above compositions for making paper or paperboard.

In another embodiment, the present invention its object is paper or cardboard, which includes swelling clay with white on Acbp at least 70.

In a preferred embodiment of the present invention, its object is the above-described paper or cardboard, which further includes a retaining polymer additive.

In another embodiment, the present invention feature is a pulp suspension comprising a retention system containing swelling clay, which has white on Acbp at least 70.

In a preferred embodiment, the object of the invention is a pulp suspension, additionally comprising a polymeric restraint Supplement.

The invention is illustrated in the following examples.

Example 1

Prepare fibrous mass with bringing its consistence (dry matter content) to 0.78 wt.%, including 37.5 wt.% hardwood, 37.5 wt.% softwood and 25 wt.% precipitated calcium carbonate. In a 500-ml aliquots of this fibrous who assy add a solution of a copolymer of acrylamide with methylchloride Quaternary ammonium salt dimethylaminoethylacrylate (mass ratio of 75/25) with characteristic higher viscosity of 11.0 DL/g with a flow rate of 0.75 lb/ton (375 ppm million) and stirred for 10 C. these aliquots with a flow rate of 4 lb/ton (2000 ppm million) add the bentonite And supplied by the plant in Waverly place, stronge, USA and has white 81. After 10 shear treatment at 1000 rpm fibrous mass is then poured into manual listonline form. From each aliquot of pulp manually in three repeated experiments produce leaves and define whiteness, fluorescence and opacity. For each worksheet calculating the mean value of the two readings. Upon completion of the tests for determining optical properties determine the ash content of the sheet.

Examples 2-4

The experiment of example 1 is repeated with the use of bentonite B, which is technically available bentonite shipped from Texas, USA, and showing the whiteness index 56, bentonite, which is technically available bentonite supplied from the UK, with a value of whiteness 33, and microgel of politicide silicon Particol®™ I (obtained in accordance with example 1 of the application WO-A 98/30753) with a flow rate of 1 lb/ton (500 ppm million).

Examples 5-20

The experiments of examples 1 to 4 is repeated, except that before adding acrylamide copolymer in each aliquot in the supplied form is injected with a flow rate of 10, 20, 30, 40, and 60 lb/t (respectively 5000, 10000, 15000, 20000 and 30,000 ppm million) optical otbelivanie the ü (Ootb) Tinopal® ™ PT Liquid New and gently stirred for 10 min, followed by stirring at 1000 rpm for 10 seconds

The results of the experiments of examples 1 to 20 are shown in table 1.

Table 1
ExampleOotb (lb/t)Bentonite or microgel silicon dioxideThe average total whiteThe average fluorescenceAverage basic white sheetAverage opacityThe average ash content of leaf (%)
10And92,60,092,690,923,4
20Into 91.60,0to 91.690,123,2
30B92,00,092,091,223,1
40Particol I92,50,092,590,123,0
510And96,1the 3.892,390,4a 21.5
610In95,6 the 3.891,890,120,8
710B96,4the 3.892,590,121,3
810Particol I96,6a 3.9of 92.790,121,1
920Andof 97.85,292,689,619,8
1020In97,05,391,7to 89.518,9
1120B97,35,2to 92.189,619,0
1220Particol I98,15,692,588,618,5
1330And98,36,192,2and 88.818,3
1430In97,26,091,289,3of 17.5
1530B97,96,191,888,217,4
1630Particol I of 98.26,2to 92.1of 89.1of 17.0
1740And98,76,6to 92.188,216,9
1840Inof 97.86,5for 91.387,516,1
1940Bof 98.26,6to 91.687,716,0
2040Particol I98,77,091,7of 87.315,5
2160And98,77,4for 91.386,815,0
2260In98,67,5to 91.186,613,9

7,4
ExampleOotb (lb/t)Bentonite or microgel silicon dioxideThe average total whiteThe average fluorescenceAverage basic white sheetAverage opacityThe average ash content of leaf (%)
2360B98.791,485,913,8
2460Particol I99,07,891,285,512,5

General white

Table 1 presents the overall degree of whiteness manually molded sheets made at each concentration Ootb. With increasing added amounts of product Tinopal®™ PT Liquid New white sheets increases. Thus, it can clearly be noted that when using bentonite with high white white sheets increases. You can also see that when using bentonite And requires less Ootb compared with cases of use of bentonites with reduced white. In order to achieve whiteness 98% for bentonite And requires only 20 pounds/ton of Ootb, whereas to achieve the same brightness with the use of bentonites B and C are required, respectively, 40 and 60 pounds/ton of Ootb.

Fluorescence

When testing all bentonites no significant differences in indicators of fluorescence between them is not noted. This indicates that the contribution in the sheet, resulting from Ootb in each case is similar, resulting in the overall degree of whiteness of the sheets varies from white bentonites (as it follows from table 1). A slightly higher importance is placed fluorescence is achieved by the processing of sheets of microgel politicide silicon Particol REF.

Basic white

Table 1 also presents the basic white sheets, i.e. white, not promotable Ootb. These values show that with increasing consumption of Ootb at all tested microparticles basic white is reduced. This is due to the decrease in retention with increasing anionic activity with the addition of product Tinopal. In this experiment, with the aim of studying the differences of white in the ordinary course of bentonite retention for first pass at a constant level is not supported. Due to the reduced retention decreases the content of the COC (precipitated calcium carbonate) sheets, which affects the basic white sheet.

However, the underlying white sheets indicates that the white sheets affects white bentonite. The data in table 1 also show that the leaves with bentonite To have less white than with bentonite B, in which it is lower than that containing bentonite A. When using bentonite And provides the same brightness as in the case of product Particol REF.

Opacity

As mentioned in the basic white sheets, with increasing consumption of Ootb by increasing anionic activity content COC decreases. This weakens the impact of the retention of ash components on the opacity of the sheet, and also white. From table 1 it is obvious that the same with the increase of consumption Ootb opacity decreases. At various microparticles no significant differences opacity is not noted.

Ash leaf

For each sheet, made in the course of this study, to determine the ash content of the sheet. The data in table 1 show that increasing consumption Ootb ash content of the sheet is reduced. This is confirmed by the decrease in retention, basic white sheets and opacity due to increased content of product Tinopal while maintaining the number of retaining additives. These values also show that due to the bentonite And the sheet is held more components of the ash than in other bentonites or product Particol REF.

Thus, in conclusion it can be noted that the use of bentonite with a whiteness index of at least 70 increases the whiteness of the sheets of paper in comparison with leaves formed using other bentonites, with reduced white indices.

Moreover, one can easily notice that when using bentonites with reduced white, to achieve the same white sheets require increased amount of Ootb.

Equivalent to the overall degree of whiteness and increased retention of ash components can be achieved using bentonite with whiteness index on m is Nisha least 70. This means that the leaves of the equivalent white and increased retention of the filler can be manufactured using bentonite with a whiteness index of at least 70.

1. A method of manufacturing paper or paperboard, including the preparation of an aqueous cellulosic suspension, adding to this pulp suspension system retention, draining the suspension on the grid forming the paper web and drying of this paper web, wherein the retention system includes a swelling clay, whiteness index which Acbp is at least 70.

2. The method according to claim 1, wherein the swelling clay is a bentonite.

3. The method according to claim 1 or 2, in which the retention system further includes a polymeric restraint Supplement.

4. The method according to claim 1 or 2, in which the pulp suspension is injected optical Brightener for paper and cardboard.

5. The method according to claim 1 or 2, in which the paper or cardboard contains a filler.

6. The method according to claim 5, in which the filler is chosen from the group comprising precipitated calcium carbonate, ground calcium carbonate, kaolin, titanium dioxide and talc.

7. The method according to claim 1 or 2, characterized in that the retention system includes swelling clay containing less than 1 wt.% one or more transition metal compounds.

8. The paper and the Arton, which can be manufactured according to claims 1-7.

9. Composition, including swelling clay with white on Acbp at least 70, and retaining polymer additive.

10. The composition according to claim 9, in which the swellable clay is a bentonite.

11. Paper or cardboard, comprising a swelling clay with white on Acbp at least 70.

12. Paper or cardboard according to claim 11, additionally comprising a polymeric restraint Supplement.

13. The pulp suspension, comprising a retention system containing swelling clay, which has white on Acbp at least 70.

14. The pulp suspension according to item 13, further comprising retaining polymer additive.



 

Same patents:

FIELD: pulp-and-paper industry, in particular paper or board production.

SUBSTANCE: claimed method includes providing of slurry containing cellulose fiber and at least sizing agent interacting with cellulose. Sizing agent is selected from group containing ketene dimmers and acid anhydrides. Cationic vinyl polymer obtained by additional polymerization, containing aromatic units and anionic vinyl polymer obtained by additional polymerization and having molecular mass from 6000-100000 are introduced into slurry. Then obtained slurry is dehydrated and paper leaf is formed.

EFFECT: increased effectiveness of sizing, dehydration and retention.

11 cl, 3 tbl, 2 ex

FIELD: polymers.

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EFFECT: polymer dispersion of high stability, high active substance content, low cationic charge, and good retention characteristics.

FIELD: paper industry.

SUBSTANCE: aqueous composition includes 0.01 to 45 % by weight of anionic organic polymeric particles and silica-based colloidal anionic particles at weight ratio between them from 20:1 to 1:50. Silica-based colloidal anionic particles are prepared by modifying silica with aluminum or amine. Anionic organic polymeric particles are prepared by polymerization of ethylenically-unsaturated monomers with multifunctional ramification agents and/or multifunctional cross-linking agents. Composition is prepared by combining the two types of particles. Papermaking method comprises adding above-prepared composition to pulp composed of cationic polymer fibers.

EFFECT: imp drying and retention properties of aqueous composition.

16 cl, 4 tbl, 4 ex

FIELD: polymer materials and papermaking industry.

SUBSTANCE: invention relates to aqueous silicon-containing composition containing anionic organic polymer comprising at least one aromatic group and silica-based anionic particles in aggregated form or microgel form. Anionic organic polymer, in particular, contains at least one aromatic group and silica-based anionic particles in amount at least 0.01% of the total mass of composition. Composition contains essentially no sizing substance capable of reacting with cellulose, whereas anionic organic polymer containing at least one aromatic group is not naphthalenesulfonate-formaldehyde condensate. Invention also relates to methods for preparing the composition and to utilization thereof as a substance providing dehydration and retention in paper making process. Invention further relates to a paper making process using aqueous suspension containing cellulose fibers and optionally filler, wherein aqueous silicon-containing composition and at least one charged organic polymer are added to pulp.

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20 cl, 4 tbl, 4 ex

FIELD: pulp-and-paper industry, in particular, sizing of paper with the use of aqueous composition.

SUBSTANCE: method involves producing aqueous composition of cellulose filaments and dehydrating paper web; adding aqueous composition to cellulose suspension, said aqueous composition comprising sizing substance aggregates; producing aqueous composition by mixing in any order before adding into aqueous suspension of aqueous solution containing at least one coagulant and aqueous dispersion containing sizing substance. Zeta-potential of composition is below 20 mV.

EFFECT: increased efficiency and simplified method.

26 cl, 5 tbl, 3 ex

FIELD: paper-and-pulp industry.

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EFFECT: improved retention and drainage allowing manufacture of high-quality cellulose products.

25 cl, 6 tbl, 27 ex

FIELD: inorganic chemistry.

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EFFECT: composition useful in production of cellulose sheet.

23 cl, 17 ex, 18 tbl

The invention relates to aqueous sols on the basis of silicon dioxide, a process for the production of sols on the basis of silicon dioxide and methods of producing paper that sols are used as additives

The invention relates to water solu containing particles on the basis of silicon dioxide, to a method for producing particles on the basis of silicon dioxide and a method for producing paper

The invention relates to a rheology modifiers to achieve the thickening effect, regulating the expiry of water retention and other properties of aqueous systems

FIELD: pulp and paper industry; methods of production of the pigment for manufacture of the cardboard and paper.

SUBSTANCE: the invention is pertaining to the method of production of the pigment for manufacture of the cardboard and paper and may be used in pulp and paper industry at production of the filled paper, the coated paper and the cardboard. Calcium carbonate is treated with aluminum sulfate in the aqueous medium. The treatment is conducted at aluminum sulfate consumption of 25-105 % to the mass of absolutely dry calcium carbonate at the temperature of 80-85°С during 90-180 minutes with production of the suspension containing 25-35 % dry substances in it. The suspension may be additionally dried and to produce the powder. The technical result of the invention is improvement of the pigment quality and expansion of the field of its application.

EFFECT: the invention ensures improvement of the pigment quality and expansion of the field of its application.

2 cl, 2 tbl

FIELD: pulp and paper industry; methods of production of the pigment for manufacture of the cardboard and paper.

SUBSTANCE: the invention is pertaining to the method of production of the pigment for manufacture of the cardboard and paper and may be used in pulp and paper industry at production of the filled paper, the coated paper and the cardboard. Calcium carbonate is treated with aluminum sulfate in the aqueous medium. The treatment is conducted at aluminum sulfate consumption of 25-105 % to the mass of absolutely dry calcium carbonate at the temperature of 80-85°С during 90-180 minutes with production of the suspension containing 25-35 % dry substances in it. The suspension may be additionally dried and to produce the powder. The technical result of the invention is improvement of the pigment quality and expansion of the field of its application.

EFFECT: the invention ensures improvement of the pigment quality and expansion of the field of its application.

2 cl, 2 tbl

FIELD: pulp and paper industry; methods of production of the pigment for manufacture of the cardboard and paper.

SUBSTANCE: the invention is pertaining to the method of production of the pigment for manufacture of the cardboard and paper and may be used in pulp and paper industry at production of the filled paper, the coated paper and the cardboard. Calcium carbonate is treated with aluminum sulfate in the aqueous medium. The treatment is conducted at aluminum sulfate consumption of 25-105 % to the mass of absolutely dry calcium carbonate at the temperature of 80-85°С during 90-180 minutes with production of the suspension containing 25-35 % dry substances in it. At that they use the aqueous medium containing the binding chosen from the group, which includes starch and polyvinyl alcohol in the amount of 0.5-3.0 mass % from the mass of the absolutely dry pigment, and-or the water soluble colorant in the amount of 0.1-0.5 mass % from the mass of the absolutely dry pigment. The suspension is additionally dried and grinded. The technical result of the invention is the improved quality of the pigment as well as expansion of its field of application.

EFFECT: the invention ensures the improved quality of the pigment as well as expansion of its field of application.

2 tbl

FIELD: pulp and paper industry; methods of production of the pigment for manufacture of the cardboard and paper.

SUBSTANCE: the invention is pertaining to the method of production of the pigment for manufacture of the cardboard and paper and may be used in pulp and paper industry at production of the filled paper, the coated paper and the cardboard. Calcium carbonate is treated with aluminum sulfate in the aqueous medium. The treatment is conducted at aluminum sulfate consumption of 25-105 % to the mass of absolutely dry calcium carbonate at the temperature of 80-85°С during 90-180 minutes with production of the suspension containing 25-35 % dry substances in it. At that they use the aqueous medium containing the binding chosen from the group, which includes starch and polyvinyl alcohol in the amount of 0.5-3.0 mass % from the mass of the absolutely dry pigment, and-or the water soluble colorant in the amount of 0.1-0.5 mass % from the mass of the absolutely dry pigment. The suspension is additionally dried and grinded. The technical result of the invention is the improved quality of the pigment as well as expansion of its field of application.

EFFECT: the invention ensures the improved quality of the pigment as well as expansion of its field of application.

2 tbl

FIELD: pulp and paper industry; methods of production of the pigment for manufacture of the cardboard and paper.

SUBSTANCE: the invention is pertaining to the method of production of the pigment for manufacture of the cardboard and paper and may be used in pulp and paper industry at production of the filled paper, the coated paper and the cardboard. Calcium carbonate is treated with aluminum sulfate in the aqueous medium. The treatment is conducted at aluminum sulfate consumption of 25-105 % to the mass of absolutely dry calcium carbonate at the temperature of 80-85°С during 90-180 minutes with production of the suspension containing 25-35 % dry substances in it. At that they use the aqueous medium containing the binding chosen from the group, which includes starch and polyvinyl alcohol in the amount of 0.5-3.0 mass % from the mass of the absolutely dry pigment, and-or the water soluble colorant in the amount of 0.1-0.5 mass % from the mass of the absolutely dry pigment. The suspension is additionally dried and grinded. The technical result of the invention is the improved quality of the pigment as well as expansion of its field of application.

EFFECT: the invention ensures the improved quality of the pigment as well as expansion of its field of application.

2 tbl

FIELD: pulp and paper industry; methods of production of the pigment for manufacture of the cardboard and paper.

SUBSTANCE: the invention is pertaining to the method of production of the pigment for manufacture of the cardboard and paper and may be used in pulp and paper industry at production of the filled paper, the coated paper and the cardboard. Calcium carbonate is treated with aluminum sulfate in the aqueous medium. The treatment is conducted at aluminum sulfate consumption of 25-105 % to the mass of absolutely dry calcium carbonate at the temperature of 80-85°С during 90-180 minutes with production of the suspension containing 25-35 % dry substances in it. At that they use the aqueous medium containing the binding chosen from the group, which includes starch and polyvinyl alcohol in the amount of 0.5-3.0 mass % from the mass of the absolutely dry pigment, and-or the water soluble colorant in the amount of 0.1-0.5 mass % from the mass of the absolutely dry pigment. The suspension is additionally dried and grinded. The technical result of the invention is the improved quality of the pigment as well as expansion of its field of application.

EFFECT: the invention ensures the improved quality of the pigment as well as expansion of its field of application.

2 tbl

FIELD: pulp and paper industry; methods of production of the pigment for manufacture of the cardboard and paper.

SUBSTANCE: the invention is pertaining to the method of production of the pigment for manufacture of the cardboard and paper and may be used in pulp and paper industry at production of the filled paper, the coated paper and the cardboard. Calcium carbonate is treated with aluminum sulfate in the aqueous medium. The treatment is conducted at aluminum sulfate consumption of 25-105 % to the mass of absolutely dry calcium carbonate at the temperature of 80-85°С during 90-180 minutes with production of the suspension containing 25-35 % dry substances in it. At that they use the aqueous medium containing the binding chosen from the group, which includes starch and polyvinyl alcohol in the amount of 0.5-3.0 mass % from the mass of the absolutely dry pigment, and-or the water soluble colorant in the amount of 0.1-0.5 mass % from the mass of the absolutely dry pigment. The suspension is additionally dried and grinded. The technical result of the invention is the improved quality of the pigment as well as expansion of its field of application.

EFFECT: the invention ensures the improved quality of the pigment as well as expansion of its field of application.

2 tbl

FIELD: pulp and paper industry; methods of production of the pigment for manufacture of the cardboard and paper.

SUBSTANCE: the invention is pertaining to the method of production of the pigment for manufacture of the cardboard and paper and may be used in pulp and paper industry at production of the filled paper, the coated paper and the cardboard. Calcium hydroxide suspension is treated with aluminum sulfate solution in the aqueous medium at stirring. The treatment is conducted in the aqueous medium containing the binding in the dissolved state. The binding is chosen from the group, which includes starch and polyvinyl alcohol in the amount of 0.5-5.0 mass % from the mass of the absolutely dry pigment, and-or the colorant in the amount of 0.1-0.5 mass % from the mass of the absolutely dry pigment. The technical result of the invention is the improved quality of the pigment and expansion of its field of application.

EFFECT: the invention ensures the improved quality of the pigment and expansion of the field of its application.

2 tbl

FIELD: pulp and paper industry; methods of production of the pigment for manufacture of the cardboard and paper.

SUBSTANCE: the invention is pertaining to the method of production of the pigment for manufacture of the cardboard and paper and may be used in pulp and paper industry at production of the filled paper, the coated paper and the cardboard. Calcium hydroxide suspension is treated with aluminum sulfate solution in the aqueous medium at stirring. The treatment is conducted in the aqueous medium containing the binding in the dissolved state. The binding is chosen from the group, which includes starch and polyvinyl alcohol in the amount of 0.5-5.0 mass % from the mass of the absolutely dry pigment, and-or the colorant in the amount of 0.1-0.5 mass % from the mass of the absolutely dry pigment. The technical result of the invention is the improved quality of the pigment and expansion of its field of application.

EFFECT: the invention ensures the improved quality of the pigment and expansion of the field of its application.

2 tbl

FIELD: pulp and paper industry; methods of production of the pigment for manufacture of the cardboard and paper.

SUBSTANCE: the invention is pertaining to the method of production of the pigment for manufacture of the cardboard and paper and may be used in pulp and paper industry at production of the filled paper, the coated paper and the cardboard. Calcium hydroxide suspension is treated with aluminum sulfate solution in the aqueous medium at stirring. The treatment is conducted in the aqueous medium containing the binding in the dissolved state. The binding is chosen from the group, which includes starch and polyvinyl alcohol in the amount of 0.5-5.0 mass % from the mass of the absolutely dry pigment, and-or the colorant in the amount of 0.1-0.5 mass % from the mass of the absolutely dry pigment. The technical result of the invention is the improved quality of the pigment and expansion of its field of application.

EFFECT: the invention ensures the improved quality of the pigment and expansion of the field of its application.

2 tbl

FIELD: pulp-and-paper industry, in particular paper or board production.

SUBSTANCE: claimed method includes providing of slurry containing cellulose fiber and at least sizing agent interacting with cellulose. Sizing agent is selected from group containing ketene dimmers and acid anhydrides. Cationic vinyl polymer obtained by additional polymerization, containing aromatic units and anionic vinyl polymer obtained by additional polymerization and having molecular mass from 6000-100000 are introduced into slurry. Then obtained slurry is dehydrated and paper leaf is formed.

EFFECT: increased effectiveness of sizing, dehydration and retention.

11 cl, 3 tbl, 2 ex

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