Papermaking process

FIELD: paper industry.

SUBSTANCE: invention relates to technology of manufacturing paper from aqueous suspension containing cellulose fibers and optional fillers. Process comprises separately adding to suspension cationic processing polymer with one or several aromatic groups and anionic polymer with one or several aromatic groups. The latter is selected from polymers prepared according to stepped molecule growth mechanism, naturally occurring polysaccharides and aromatic polymers and modifications thereof, provided that, if anionic polymer is polymer prepared according to stepped molecule growth mechanism, then it cannot be anionic condensation polymer based on melaminesulfonic acid. Another condition that could be alternatively fulfilled is that anionic polymer is not anionic polystyrenesulfonate or anionic condensation polymer based on melaminesulfonic acid. Suspension is then molded into sheet and dehydrated on screen.

EFFECT: improved dehydration and/or retention during making of paper from all types of fibrous pulps, including those with high content of salts, and increased strength of dry paper.

19 cl, 10 tbl, 11 ex

 

This invention relates to the manufacture of paper and, more specifically, to a method of making paper, in which the fibrous mass in paper production type cationic and anionic polymers having aromatic groups. This method provides improved dewatering and retention.

State of the art in paper production of aqueous suspension containing cellulosic fibres, and optional fillers and additives, called fibrous mass, served in the headbox from which the fibrous mass is pushed on the grid for molding. Water away from the pulp through the mesh for forming such a way that the grid is forming a damp cloth, paper, and canvas additionally dehydrated and dried in the dryer section of the papermaking machine. Water received, usually called circulating water containing finely ground particles, such as finely chopped fibers, fillers and additives in paper manufacturing process usually sent for recycling. In the fibrous mass is usually injected additives that promote dehydration and retention, in order to facilitate the flow of dehydration and increase the efficiency of adsorption of finely ground particles to cellulosic fibers so that they are retained on the fibers. In addition to the level of techniques known to a wide variety of additives, contributing to dehydration and retention, such as anionic, nonionic, kationye and amphoteric organic polymers, anionic and cationic inorganic substances, and many combinations thereof.

Publication of international patent application no WO 99/55964 and WO 99/55965 describe the use of additives that contribute to dehydration and hold containing cationic organic polymer having an aromatic group. Cationic organic polymers can be used individually or in combination with other anionic substances, such as, for example, anionic organic and inorganic condensation polymers, such as sulfonated melamine-formaldehyde resin and particles on the basis of silicon dioxide.

It would be advantageous to be able to provide a method of making paper with improved dewatering and retention. Also, it would be advantageous to be able to get supplements that promote dehydration and hold containing cationic organic polymers and anionic polymers with improved performance characteristics in relation to dewatering and retention.

In accordance with the present invention was found to enhance dewatering and/or retention can be achieved in the use of additives that contribute to dehydration and retention, containing the x cationic organic polymer, having an aromatic group and an anionic polymer having an aromatic group. More specifically, the present invention relates to a method of making paper from an aqueous suspension containing cellulosic fibres, and optional fillers, which comprises adding to the suspension separately cationic organic polymer having an aromatic group and an anionic polymer having an aromatic group, with the anionic polymer is chosen from polymers produced by the mechanism of stepwise growth molecules, polysaccharides and aromatic polymers found in nature, and their modifications, forming and dewatering the suspension on the grid, with the proviso that, if the anionic polymer is chosen from polymers produced by the mechanism of stepwise growth molecules, they will not be anionic condensation polymer based on malminkartano acid. The invention additionally relates to a method of making paper from an aqueous suspension containing cellulosic fibres, and optional fillers, which comprises adding to the suspension separately cationic organic polymer having an aromatic group and an anionic polymer having an aromatic group, forming and dewatering the suspension on the grid, with the proviso that the anionic polymer will not be the anion of the first polystyrenesulfonate or anionic condensation polymer based on malminkartano acid. Thus, the invention relates to a method, further defined in the claims.

The term “additives that promote dehydration and retention in accordance with how it is used in the present description, refers to two or more components, in which case they are added to the aqueous pulp suspension, provide the best course of dehydration and/or retention compared with what would have occurred without the addition of the two or more components.

The present invention allows to improve the dehydration and/or retention in the manufacture of paper of all types of pulp, in particular fibrous masses with high salt content (high conductivity) and colloidal substances and/or methods of making paper with a high degree of closed loop circulating water, that is, the circulation of the circulating water on a large scale and with a limited supply of fresh water. Thus, the present invention makes it possible to increase the speed of the paper machine and the use of lower dosages of additives to obtain the corresponding effect of dehydration and/or retention, which in result leads to the creation of an improved method of making paper and the achievement of economic benefits. This is completed with the invention also offers paper with improved strength in the dry state.

Cationic organic polymer having an aromatic group and corresponding to the present invention, can be obtained from natural or synthetic sources, and it can be linear, branched or cross stitched. The cationic polymer is preferably soluble or dispersible in water. Examples of suitable cationic polymers include cationic polysaccharides, such as starches, guar gums, cellulose, chitina, chitosans, glikana, galactanes, glucans, xanthan gums, pectins, mannans, dextrins, preferably starches and guar gums, and suitable starches include starches from potato, corn, wheat, tapioca, rice, waxy maize, barley and the like; cationic synthetic organic polymers, such as cationic polymers produced by the mechanism of chain growth molecules, such as cationic vinyl polymers obtained by polyprionidae-like polymers based on acrylate, acrylamide, and vinylamine vinylamide, and cationic polymers produced by the mechanism of stepwise growth molecules, such as cationic polyurethanes. Cationic starch and cationic polymers based on acrylamide having an aromatic group, are particularly preferred cationic polymers.

Cationic organic polymer according to the corresponding present invention, has one or more aromatic groups and aromatic groups may be the same or different types. The aromatic group of the cationic organic polymer may be present in the polymer chain (main chain) or in a group substituent that is attached to the polymer chain, preferably a group of the Deputy. Examples of suitable aromatic groups include aryl, aracelio and albarillo group, for example phenyl, fenelonov, naftalina, fenelonov, xylylene, benzyl and phenylethylene; nitrogen-containing aromatic (aryl) groups, for example, pyridine and chinoline, as well as derivatives of these groups, preferably benzyl. Examples of groups having a cationic charge that may be present in the cationic polymer and the monomers used to obtain the cationic polymer include Quaternary ammonium groups, tertiary amino groups and their additive salt of the acid.

In accordance with a preferred implementation of the present invention, a cationic organic polymer having an aromatic group is a polysaccharide described by General structural formula (I):

where R represents the residue of a polysaccharide; And1is a group that adds N to the residue of the polysaccharide, in an appropriate case, the AE chain atoms, including atoms and N atoms and optionally O and/or N, usually alkylenes group containing from 2 to 18, and in an appropriate case, from 2 to 8 carbon atoms, optionally interrupted or substituted by one or more heteroatoms, such as O or N, such as accelerograph or hydroxypropranolol group (-CH2-CH(OH)-CH2-); each of R1and R2represents H or, preferably, a hydrocarbon group, in an appropriate case, alkyl containing from 1 to 3 carbon atoms, preferably from 1 to 2 carbon atoms; Q represents a Deputy containing aromatic group, in a suitable case, phenyl or substituted phenyl group, which may be attached to the nitrogen through alkalinous group, typically containing 1 to 3 carbon atoms, in an appropriate case, from 1 to 2 carbon atoms, and preferably Q is a benzyl group (-CH2-C6H5); n is an integer, typically in the range from approximately 2 to approximately 300,000, in an appropriate case, from 5 to 200,000, and preferably from 6 to 125,000, or alternatively, R1, R2and Q together with N form an aromatic group containing from 5 to 12 carbon atoms; and X-is an anionic counterion, typically a halide, such is chloride. Suitable polysaccharides described General formula (I)include those that were mentioned above. Cationic polysaccharides, corresponding to the present invention can also contain anionic groups, preferably in small quantities. These anionic groups can be introduced into the polysaccharide as a result of chemical treatment, or they may be present in natural polysaccharide.

In accordance with another preferred variant of the present invention, a cationic organic polymer having an aromatic group is a polymer obtained by the mechanism of chain growth molecules. The term “polymer obtained by the mechanism of chain growth molecules,” in accordance with how it is used in the present description, refers to a polymer obtained by chain polymerization, also called polymer obtained by chain reaction, and the polymerization walking on chain reaction, respectively. Examples of suitable polymers produced by the mechanism of chain growth molecules include vinyl polymers obtained by polyprionidae, which are the result of the polymerization of one or more monomers having a vinyl group or relationship with the unsaturation of ethylene type, for example a polymer obtained by polymerization of a cationic monomer or a mixture of a monomial is the moat, containing cationic monomer described by General structural formula (II):

where R3represents N or CH3; each of R1and R2represents H or, preferably, a hydrocarbon group, in an appropriate case, the alkyl containing from 1 to 3 carbon atoms, preferably from 1 to 2 carbon atoms; And2represents O or NH;2represents an alkyl or alkilinity group containing from 2 to 8 carbon atoms, in an appropriate case, from 2 to 4 carbon atoms, or hydroxypropranolol group; Q represents a Deputy containing aromatic group, in a suitable case, phenyl or substituted phenyl group, which may be attached to the nitrogen through alkalinous group, typically containing 1 to 3 carbon atoms, in an appropriate case, from 1 to 2 carbon atoms, and preferably Q is a benzyl group (-CH2-C6H5); and X-is an anionic counterion, typically a halide like chloride.

Examples of suitable monomers described General formula (II)include Quaternary monomers, obtained by processing dialkylaminoalkyl(meth)acrylates, such as dimethylaminoethyl(meth)acrylate, diethylaminoethyl(meth)acrylate and dime aminohydroxylation(meth)acrylate, and dialkylaminoalkyl(meth)acrylamides, such as dimethylaminoethyl(meth)acrylamide, diethylaminoethyl(meth)acrylamide, dimethylaminopropyl(meth)acrylamide and diethylaminopropyl(meth)acrylamide, benzylchloride. Preferred cationic monomers described General formula (I)include Quaternary salt obtained from dimethylaminoethylacrylate and benzylchloride, and the Quaternary salt obtained from dimethylaminoethylmethacrylate and benzylchloride. The monomer described by formula (II)can be copolymerisate with one or more non-ionic, cationic and/or anionic monomers. Suitable copolymerizate non-ionic monomers include (meth)acrylamide; monomers on the basis of acrylamide, such N-alkyl(meth)acrylamide, N,N-dialkyl(meth)acrylamides and dialkylaminoalkyl(meth)acrylamide, monomers, acrylate-based, such dialkylaminoalkyl(meth)acrylates, and vinylamide. Suitable copolymerizate cationic monomers include additive salt of the acid and Quaternary salts, such as dimethylaminoethyl(meth)acrylate and chloride of diallyldimethylammonium. Cationic organic polymer can also contain anionic groups, preferably in small quantities. Suitable copolymerizate anionic monomers include acrylic acid, methacrylic acid and various sulfonated vinyl monomers such as tirolalpin. Preferred copolymerizate monomers include acrylamide and methacrylamide, that is, (meth)acrylamide, and cationic or amphoteric organic polymer preferably is a polymer based on acrylamide.

Cationic vinyl polymers obtained by polyprionidae, corresponding to this invention, can be obtained from a mixture of

monomers, generally containing from 1 to 99% (mole.), in an appropriate case, from 2 to 50% (mol.), and preferably from 5 to 20% (mole.) cationic monomer having an aromatic group, and from 99 to 1% (mol.), in an appropriate case, from 98 to 50% (mole.), and preferably from 95 to 80% (mole.) other copolymerizing monomers, which preferably include acrylamide or methacrylamide ((meth)acrylamide), and in an appropriate case, the mixture of monomers contains from 98 to 50% (mole.), and preferably from 95 to 80% (mole.) (meth)acrylamide, and the sum of the percentages is equal to 100.

Examples of suitable cationic polymers obtained by the mechanism of chain growth molecules relevant for this invention include cationic polyurethanes, which can be obtained from a mixture of monomers containing aromatic isocyanates and/or aromatic alcohols. Examples of suitable aromatic isocyanates include diisocyanates, such as toluylene-2,4 - and -2,6-diisocyanate and difenilmetana-4,4ȃ -diisocyanate. Examples of suitable aromatic alcohols include diatomic alcohols, i.e. diols, such as bisphenol a, phenyldiethanolamine, Montereale glycerin and Montereale of trimethylolpropane. You can also use and monohydroxy aromatic alcohols such as phenol and its derivatives. The mixture of monomers may also contain non-aromatic isocyanates and/or alcohols, usually diisocyanates and diols, for example any of those that are known for their usefulness in obtaining polyurethanes. Examples of suitable monomers containing cationic groups include cationic diols, such as additive salt of the acid and the products of quaternization of N-arcandyalagireeio and N-alkyldiethanolamine, such 1,2-propandiol-3-dimethylamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-propylnitrosamine, N-n-butyldiethanolamine and N-tert-butyldiethanolamine, N-steeringmechanism and N-methyldiphenylamine. The products of quaternization can be obtained from alkylating agents such as methyl chloride, dimethylsulfate, benzylchloride and epichlorohydrin.

Srednevekovaja molecular weight cationic polymer may vary within wide limits depending on, inter alia, on the type of the polymer used, and usually it is at least equal to about 5000, and often at least equal to 10000. More often it is pre Iset 150000, usually exceeds 500000, in an appropriate case exceeds approximately 700000, preferably in excess of about 1000000, and most preferably in excess of about 2000000. The upper limit is not critical; it may be equal to about 200000000, usually 150000000 and in a suitable case 100000000.

Cationic organic polymer can vary the degree of cationic substitution (DSC), varying in a wide range depending, inter alia, on the type of the polymer used; DSCmay be in the range of 0.005 to 1.0, usually from 0.01 to 0.5, in an appropriate case, from 0.02 to 0.3, preferably from 0.025 to 0.2; and the degree of aromatic substitution (DSQmay be in the range of from 0.001 to 0.5, usually from 0.01 to 0.5, in an appropriate case, from 0.02 to 0.3, and preferably from 0.025 to 0.2. In the case of cationic organic polymer will contain anionic groups, then the degree of anionic substitution (DSAmay be in the range from 0 to 0.2, in an appropriate case, from 0 to 0.1, and preferably from 0 to 0.05, and the cationic polymer will generally have a cationic charge. Typically, the charge density of the cationic polymer is in the range from 0.1 to 6.0 mEq./g of dry polymer in a suitable case from 0.2 to 5.0, and preferably from 0.5 to 4.0.

Examples of suitable cationic organic polymer is, having an aromatic group that can be used in accordance with the present invention, include those described in the publications of international applications No. WO 99/55964, WO 99/55965 and WO 99/67310 that, therefore, included in this document as a reference.

Anionic polymers having an aromatic group, corresponding to the present invention can be selected from the polymers produced by the mechanism of stepwise growth molecules, polymers obtained by the mechanism of chain growth molecules, polysaccharides, aromatic polymers found in nature, and their modifications. The term “polymer obtained by the mechanism of stepwise growth molecules,” in accordance with how it is used in the present description, refers to a polymer obtained by stepwise polymerization, also called polymer obtained by stepwise reaction, and the polymerization walking on the speed of the reaction, respectively. Anionic polymer is preferably selected from polymers produced by the mechanism of stepwise growth molecules, polysaccharides and aromatic polymers found in nature, and their modifications, most preferably from polymers produced by the mechanism of stepwise growth of the molecule. Anionic polymers, corresponding to the present invention may be linear, branched or pop the fluvial stitched. Anionic polymer is preferably soluble or dispersible in water. Anionic polymer is preferably organic.

Anionic polymer, corresponding to this invention, has one or more aromatic groups and aromatic groups may be the same or different types. The aromatic group of the anionic polymer may be present in the polymer chain or in a group substituent that is attached to the polymer chain (the main chain). Examples of suitable aromatic groups include aryl, aracelio and albarillo groups and their derivatives, such as phenyl, taillow, naftalina, fenelonov, xylylene, benzyl, phenylethylene and derivatives of these groups. Examples of groups that have anionic charge, which may be present in the anionic polymer and the monomers used in the preparation of the anionic polymer include group bearing an anionic charge, and the acid group bearing an anionic charge when there is a dissolution or dispersion in water, and these groups, herein collectively called anionic groups are groups such as phosphate, phosphonate, sulfate group, a sulfonic acid group, sulfate group, a carboxylic acid group, carboxylate, alkoxide and phenolic groups i.e. the replacement family and nattily. Group carrying anionic charge, usually are salts of alkali metal, alkaline earth metal or ammonia.

Examples of suitable anionic polymers obtained by the mechanism of stepwise growth of the molecules of the present invention include condensation polymers, i.e. polymers obtained by stepwise polycondensation, for example condensation products of an aldehyde, such as formaldehyde, with one or more aromatic compounds containing one or more anionic groups, and optionally other comonomers suitable for polycondensation, such as urea and melamine. Examples of suitable aromatic compounds containing anionic groups include compounds based on benzene and naphthalene containing anionic groups, such as phenolic and naftalie compounds, such as phenol, naphthol, resorcinol and derivatives thereof, aromatic acids and their salts, such as carbolic, phenolic, naftalina and naftolin acid and salt, usually sulfonic acids and sulfonates, such as benzosulfimide acid and sulfonate, cellculture acid and sulfonates, naphtalenesulfonic acid and sulfonate, phenolsulfonic acid and sulfonate. Examples of suitable anionic polymers obtained by the mechanism of stepwise growth of the molecules correspond to their this invention, include anionic condensation polymers on the basis of the benzene and naphthalene, preferably condensation polymers based on naphtalenesulfonic acid and based naphthalenesulfonate.

Examples of other suitable anionic polymers obtained by the mechanism of stepwise growth of the molecules of the present invention include polymers obtained by polyprionidae, i.e. polymers obtained by stepwise polyaddition, for example, anionic polyurethanes, which can be obtained from a mixture of monomers containing aromatic isocyanates and/or aromatic alcohols. Examples of suitable aromatic isocyanates include diisocyanates, such as toluylene-2,4 - and -2,6-diisocyanate and difenilmetana-4,4′-diisocyanate. Examples of suitable aromatic alcohols include diatomic alcohols, i.e. diols, such as bisphenol a, phenyldiethanolamine, Montereale glycerin and Montereale of trimethylolpropane. You can also use and monohydroxy aromatic alcohols such as phenol and its derivatives. The mixture of monomers may also contain non-aromatic isocyanates and/or alcohols, usually diisocyanates and diols, for example any of those that are known for their usefulness in obtaining polyurethanes. Examples of suitable monomers containing anionic groups include the two is present complex monoamine products of the reactions of triolo, for example trimethyloctane, trimethylolpropane and glycerol, dibasic carboxylic acids or their anhydrides, such as succinic acid and anhydride, terephthalic acid and anhydride, such as monocalcium glycerin, Montereale glycerin, monocalcium of trimethylolpropane, Montereale of trimethylolpropane, N,N-bis(hydroxyethyl)glycine, di(hydroxymethyl)propionic acid, N,N-bis(hydroxyethyl)-2-aminoetansulfonovaya acid and the like, optional and usually in combination with a reaction with a base, such as hydroxides of alkali metals and alkaline earth metals, such as sodium hydroxide, ammonia or amine, such as triethylamine, obtaining, thus, the counterion formed alkali metal, alkaline earth metal or ammonium.

Examples of suitable anionic polymers obtained by the mechanism of chain growth molecules relevant for this invention include anionic vinyl polymers obtained by polyprionidae, which is prepared from a mixture of the vinyl monomer or monomers with the unsaturation of ethylene type, containing at least one monomer having an aromatic group and at least one monomer having an anionic group, usually copolymerizing with non-ionic monomers, such as monomers on the basis of acrylate and acrylamide. Por the action of suitable anionic monomers include (meth)acrylic acid and parameningeal (hydroxytrol).

Examples of suitable anionic polysaccharides include starches, guar gums, cellulose, chitina, chitosans, glikana, galactanes, glucans, xanthan gums, pectins, mannans, dextrins, preferably starches, guar gums and cellulose derivatives, and suitable starches include starches from potato, corn, wheat, tapioca, rice, waxy maize and barley, preferably from potatoes. Anionic groups in the polysaccharide may be available from nature and/or introduced as a result of chemical processing. Aromatic groups in the polysaccharide can be entered using chemical methods known at the present level of technology.

Aromatic anionic polymers found in nature, and their modifications, i.e. modified aromatic anionic polymers found in nature, corresponding to the present invention include naturally occurring polyphenolic substances, which are present in wood and organic extracts of the bark of some tree species, and their chemical modification, usually sulfonated modification. The modified polymers can be obtained as a result of such chemical processes, such as sulfite cooking and sulphate cooking. Examples of suitable anionic polymers of this type include polymers based on lignin, before occhialino sulfonated lignins, for example lignosulfonates, sulfate lignin, sulfonated sulfate lignin and tannin extracts.

The mass-average molecular weight anionic polymer may vary within wide limits depending on, inter alia, on the type of the polymer used, and usually it is at least equal to about 500, in an appropriate case, in excess of about 2000, and preferably greater than about 5000. The upper limit is not critical; it may be equal to about 200000000, usually 150000000, in an appropriate case, 100000000, and preferably 10000000.

The anionic polymer can vary the degree of anionic substitution (DSAnd), varying in a wide range depending, inter alia, on the type of the polymer used; DSAndis usually in the range from 0.01 to 2.0, in an appropriate case, from 0.02 to 1.8, and preferably from 0.025 to 1.5; and the degree of aromatic substitution (DSQmay be in the range of from 0.001 to 1.0, usually from 0.01 to 0.8, in an appropriate case, from 0.02 to 0.7, and preferably from 0.025 to 0.5. In that case, if the anionic polymer will contain cationic groups, then the degree of cationic substitution (DSWith) may, for example, be in the range of from 0 to 0.2, in an appropriate case, from 0 to 0.1, and preferably from 0 to 0.05, and the anionic polymer will have anionic C is a number. Usually the density of the anionic charge of the anionic polymer is in the range from 0.1 to 6.0 mEq/g dry polymer, in a suitable case from 0.5 to 5.0, and preferably from 1.0 to 4.0.

Examples of suitable anionic aromatic polymers that can be used in accordance with the present invention, include those described in U.S. patent No. 4070236 and 5755930; and publications of international patent application no WO 95/21295, WO 95/21296, WO 99/67310 and WO 00/49227 that, therefore, included in this document as a reference.

Examples of particularly preferred combinations of anionic and cationic polymers having aromatic groups defined above, which correspond to the present invention include

(i) cationic polysaccharides, preferably cationic starch and anionic polymers produced by the mechanism of stepwise growth of the molecule, in an appropriate case, anionic condensation polymers on the basis of the benzene and naphthalene and anionic polyurethanes, preferably anionic condensation polymers based on naphthalene;

(ii) cationic polysaccharides, preferably cationic starch, and aromatic anionic polymers found in nature, and their modifications, in an appropriate case, anionic polymers on the basis of lignin, preferably sulfonated lignins;

(iii) cationic polymer is, produced by the mechanism of chain growth molecules, in an appropriate case, the cationic vinyl polymers obtained by polyprionidae, preferably cationic polymers based on acrylamide and anionic polymers obtained by step-growth molecules, in an appropriate case, anionic condensation polymers on the basis of the benzene and naphthalene and anionic polyurethanes, preferably anionic condensation polymers based on naphthalene; and

(iv) cationic polymers obtained by chain-growth molecules, in an appropriate case, the cationic vinyl polymers obtained by polyprionidae, preferably cationic polymers based on acrylamide, and aromatic anionic polymers found in nature, and their modifications, in an appropriate case, anionic polymers on the basis of lignin, preferably sulfonated lignins.

Cationic and anionic polymers, corresponding to the present invention, is preferably added to the aqueous suspension containing cellulosic fibers, or fibrous mass separately, and not in the form of a mixture containing the said polymers. Cationic and anionic polymers are preferably added to the fiber at different points. The polymers can be added in any order. Usually in fibrous mass of the first type of cationic polymer and anionic the polymer is added after that, although you can also use the reverse order they were added.

The polymers can be added to be dewatered fibrous mass in amounts which can vary within wide limits depending on, inter alia, on the type of pulp, salt content, type of salts, filler content, type of filler, the insertion point and the like. In General, polymers are added in an amount which provides improved dewatering and/or retention compared with what takes place without adding them, and usually in fibrous mass cationic polymer is added before the addition of the anionic polymer. The cationic polymer is usually added in the amount of at least 0.001%, often at least equal to 0.005% (mass.), calculated on dry substance of the fibrous mass, while the upper limit is usually equal to 3%, and in a suitable case to 2.0% (wt.). Anionic polymer is usually added in the amount of at least 0.001%, often at least equal to 0.005% (mass.), calculated on dry substance of the fibrous mass, while the upper limit is usually equal to 3%, and in an appropriate case, 1.5% (mass.).

The polymers having aromatic groups in accordance with the invention, can be used in combination with additional additives (additive), which have a beneficial effect on the General EC is operating characteristics in relation to dehydration and/or retention, thus, forming additives that promote dehydration and retention, comprising three or more components. Examples of suitable additives to the fibrous mass of this type include anionic substances in the form of microparticles, for example, particles based on silica and clay smectites type, low molecular weight cationic organic polymers, aluminum compounds, anionic vinyl polymers obtained by polyprionidae, and combinations thereof, including compounds and their use is described in the publications of international patent application no WO 99/55964 and WO 99/55965, which are incorporated herein by reference.

Low molecular weight (hereinafter in this document NM) cationic organic polymers that can be used in accordance with this invention include those generally referred to as traps for anionic impurities (ATS). Cationic organic NM-polymer can be obtained from natural or synthetic sources, and preferably is a synthetic NM-polymer. Suitable organic polymers of this type include cationic organic NM-polymers with high charge, such as polyamine, polyamidoamine, polyethyleneamine, Homo - and copolymers based on chloride of diallyldimethylammonium, (meth)acrylamide and (meth)acrylates. Compared with molecular assoication organic polymer, having an aromatic group corresponding to this invention, the molecular weight cationic organic NM-polymer preferably less; in an appropriate case it is equal to at least 2000 and preferably at least 10000. The upper limit of molecular weight is usually equal to approximately 700000, in an appropriate case, around 500,000, and usually about 200,000.

Aluminum compounds that can be used in accordance with this invention include alum, aluminates, aluminium chloride, aluminum nitrate and semi-aluminum compounds such as semi-aluminum chlorides, semi-aluminum sulfate, poly-aluminum alloys compounds containing both chloride and sulphate ions, semi-aluminum silicate-sulphate and mixtures thereof. Semi-aluminum compounds can also contain anions other than chloride ions, for example anions from sulfuric acid, phosphoric acid, organic acids such as citric acid and oxalic acid.

The method of the present invention can be applied to all methods of making paper and for all suspensions of cellulose, and it is particularly suitable for receiving the paper from the pulp, which has a high conductivity. In such cases, the conductivity of the fibrous mass, which dehydrate on the net, usually at least equal to 2.0 MS/cm in an appropriate case, at least a 3.5 MS/cm, and preferably at least 5,0 MSM/see Conductivity can be measured using standard equipment, such as, for example, the device WTW LF 539 supplied by Christian Berner. The values given above, in an appropriate case, determine through measurement of the conductivity of the pulp suspension, which is served in the headbox of the paper machine, or there, or alternatively, conducting measurements of the conductivity of the circulating water resulting from dewatering of the suspension. High conductivity levels indicate a high content of salts (electrolytes), which may have its origin materials used in the formation of the fibrous mass, various additives introduced into the fiber, fresh water, fed to the process, and the like. In addition, the salt content is usually higher in the processes in which on a large scale are recycling recycled water that can lead to the accumulation of significant quantities of salts in the water circulating in the process.

The present invention additionally encompasses methods of making paper, which on a large scale are recycling recycled water or sending it for recycling, i.e. with a high degree of closed loop circulating water, in the example, when one ton of dry made of paper are used from 0 to 30 tons of fresh water, usually less than 20, in an appropriate case, less than 15, preferably less than 10, especially less than 5 tons of fresh water per ton of paper. Recycling recycled water obtained in the process in an appropriate case involves mixing of the circulating water and cellulose fibers and/or optional fillers with education subject to dehydration of the suspension; it preferably involves mixing of the circulating water from a suspension containing cellulosic fibres, and optional fillers, before the suspension will get on the net for molding for dehydration. The circulating water can be mixed with the slurry prior to, in between, simultaneously with or after the introduction of additives that contribute to dehydration and maintain relevant for this invention. Fresh water can be introduced into the process at any stage; for example, it can be mixed with cellulose fibers to form a suspension, and it can be mixed with a concentrated suspension containing cellulosic fibres, for its dilution in order to obtain a diluted suspension to be dewatered before, simultaneously with or after mixing the suspension with circulating water.

Needless to say, that in combination with the polymers thus ejstvujuschij this invention, you can use the optional additives that are commonly used in the manufacture of paper, such as, for example, additions, giving strength in the dry state, additions, giving strength in the wet state, optical brighteners, dyes, sizing agents, such sizing agents based on rosin and sizing agents having reactivity with respect to the cellulose, for example, alkyl - and alkenylamine dimers, alkyl - and alkenylamine multimer and the anhydrides of succinic acid and the like. Suspension of cellulose or fibrous mass may also contain mineral fillers commonly used types, such as, for example, kaolin, white clay, titanium dioxide, natural gypsum, talc and natural and synthetic calcium carbonates such as chalk, ground marble and precipitated chalk.

The method of the present invention is used for the manufacture of paper. The term “paper” in accordance with how it is used in this description, of course, includes not only paper and products from it, but also other products such as sheets or fabrics containing cellulosic fibers, such as, for example, stove and cardboard and products from them. The method can be used in the manufacture of paper from different types of suspensions of fibers, the soda is containing cellulose, and of suspension shall contain in appropriate case, at least 25% (mass.), and preferably at least 50% (mass.) such fibers in the dry substance. The basis of the suspension can be fibers of technical pulp, such as sulphate, sulphite cellulose pulp obtained by cooking using organic solvents, wood pulp, such as thermomechanical pulp, chemi-thermomechanical pulp, refiner pulp and groundwood pulp from hardwood and softwood, and its basis can also be recycled fiber, not necessarily from the pulp after washing off the ink, and mixtures thereof.

This invention is further illustrated by the following examples, which, however, do not intend to limit the invention. Parts and % are mass parts and % (mass.) accordingly, unless otherwise stated.

Example 1.

The cationic polymers used in the tests were purchased on the market or received in accordance with well known techniques. Cationic polysaccharides used in the tests was obtained by the reaction between natural potato starch and quaternization agent in accordance with the General method described in EP - A 0189935 and WO 99/55964. Cation is haunted polymers, used in the tests, here and later in this document also collectively called cationic polymer, from C1 to C3, corresponding to the present invention, and C1 - EUR. to C3 - EUR., intended for comparison purposes, were as follows:

C1: Cationic starch obtained by quaternization of natural potato starch using 3-chloro-2-hydroxypropyltrimethylammonium chloride content of 0.5% n

C2: Cationic starch obtained by quaternization of natural potato starch using 3-chloro-2-hydroxypropyltrimethylammonium chloride content of 0.7% n

C3: Cationic vinyl polymer obtained by polyprionidae of acrylamide (90% (mole.)) and chloride of acrylonitrilebutadiene (10% (mole.)), molecular weight of approximately 6000000.

C1 - EUR.: Cationic starch obtained by quaternization of natural potato starch using 2,3-epoxypropyltrimethylammonium chloride content of 0.8% n

C2 - EUR.: Cationic starch obtained by quaternization of natural potato starch using 2,3-epoxypropyltrimethylammonium chloride content of 0.5% n

C3 - EUR.: Cationic vinyl polymer obtained by polyprionidae of acrylamide (90% (mole.)) and acrylonitrilebutadiene chloride (10% (m is ln.)), molecular weight of approximately 6000000.

Anionic polymers used in the tests were purchased on the market or received in accordance with well known techniques. Anionic polymers used in the tests hereinafter herein also collectively called anionic polymer, from A1 to A8 corresponding to the present invention, and A1 - EUR. to A2 - EUR., intended for comparison purposes, were as follows:

A1: Anionic polycondensation product of formaldehyde and naphthalenesulfonate a molecular weight of approximately 20,000.

A2: Anionic polycondensation product of formaldehyde and naphthalenesulfonate, molecular weight of approximately 110000.

A3: Anionic polycondensation product of formaldehyde and naphthalenesulfonate a molecular weight of about 40,000.

A4: Anionic polycondensation product of formaldehyde and naphthalenesulfonate, molecular weight approximately 210000.

A5: Anionic polyurethane resulting from the reaction of glycerol monostearate and truediscrete with obtaining prepolymer containing terminal isocyanate groups in the reaction which was then introduced dimethylolpropionic acid.

A6: Anionic polyurethane obtained by the reaction of phenyldiethanolamine and truediscrete obtaining f is Calimera, containing terminal isocyanate groups in the reaction which was then introduced dimethylolpropionic acid and N-methyldiethanolamine.

A7: Anionic sulfonated sulfate lignin.

A8: Anionic lignosulfonate.

A1 - Anionic melamine - formaldehyde - EUR.: sulphonate polycondensation product.

A2 - Anionic inorganic condensation - EUR.: the polymer of silicic acid in the form of colloidal particles of silica with a particle size of 5 nm.

Low molecular weight cationic organic polymer, also referred to as PABX which was used in some of the tests could be purchased on the market and can be obtained in accordance with known techniques. ATS was as follows:

ATS: Cationic copolymer of dimethylamine and epichlorohydrin and ethylene diamine with a molecular mass of approximately 50000.

All the polymers used in the form of dilute aqueous solutions of polymers.

Example 2.

Performance in respect of dehydration was assessed using a dynamic analyzer dehydration (DDA), purchased the company Akribi, Sweden, which measures the time of dehydration specified volume of pulp through the mesh when you remove the plugs and vacuum on the other side of the grid, which is the opposite side, which is the fibrous mass.

Standard fibrous mass was obtained from the composition for the manufacture of paper on the basis of 56% (mass.) bleached peroxide TMP/SGW (thermomechanical pulp/ground wood) (80/20), 14% (mass.) bleached sulphate pulp based on wood birch/pine (60/40), ground to 200° CSF (degree of milling on the canadian standard device), and 30% (mass.) white clay. To the fibrous mass was added 25 g/l colloidal fraction, bleach with a paper mill. The volume of the fibrous mass was 800 ml, and the pH was approximately equal to 7. In the fibrous mass was added calcium chloride in order to increase the conductivity of 0.5 MS/see the Obtained fibrous mass was called the standard fibrous mass. To the standard fibrous mass was added an additional amount of calcium chloride in order to obtain a fibrous mass with an average conductivity of 2.0 MS/cm) and a fibrous mass with a high conductivity (5,0 MS/cm).

Fibrous mass was stirred container with partitions with a speed of 1500 revolutions per minute throughout the test, and the addition of chemicals was carried out as follows: (i) adding to the fibrous mass of the cationic polymer, followed by stirring for 30 seconds, ii) adding to the fibrous mass of the anionic polymer, followed by stirring for 15 is of econd, iii) dewatering the fibrous mass with automatic time recording dehydration. If used ATS, the fibrous mass is added to it, and then spent the agitation for 30 seconds before i add the cationic polymer and (ii) to add anionic polymer in accordance with the methodology described above.

Table 1 demonstrates the effect of dehydration (release of water) at various dosages of cationic polymer C1, calculated as the number of dry polymer on the number of systems in the form of a dry fibrous mass, and different dosages of anionic polymers A1 - EUR., A1 and A2, calculated as the number of dry polymer on the number of systems in the form of a dry fibrous mass. Standard fiber used in tests No. 1-5, and fibrous mass with a high conductivity used in tests No. 6-9.

Table 1.
No.DosageDosageTime dehydration [sec].
test.C1 [kg/t].[Kg/t].A1 - EUR.A1A2
130019,019,019,0
2300,5of 17.5of 17.015,5
3301,014,612,612,1
4302,012,89,08,4
5303,09,88,77,2
620026,426,426,4
7202,0a 21.515,7the 15.6
8203,017,614,613,7
9204,015,714,5the 13.4

Example 3.

Retention for first pass was assessed using turbidity meter, carrying out the measurement of the turbidity of the filtrate from the dynamic analyzer dehydration (DDA), recycled water obtained by dewatering the pulp obtained in example 2. The results shown in table 2.

Table 2.
no test.Dosage C1 [kg/t].The dosage As [kg/t].Turbidity [NTU values (unit turbidity)].
   A1 - EUR.A1A2
1300,5564955
2301,0555050
3302,0524748
4303,0504345

Example 4.

Performance in respect of dehydration was assessed using cationic and anionic polymers corresponding to example 1, and the standard fibrous mass and techniques relevant to example 2. The results shown in table 3.

Table 3.
No.DosageDosageTime dehydration [sec].
test.C1 [kg/t].[Kg/t].A1A3A4
10 018,018,018,0
220012,512,512,5
3201,010,910,010,2
4202,010,39,08,9
5204,010,08,78,0

Example 5.

Performance in respect of dehydration was assessed using cationic and anionic polymers corresponding to example 1, and fibrous masses with an average conductivity and techniques relevant to example 2. The results shown in table 4.

10
Table 4.
No.DosageDosageTime dehydration [sec].
test.[Kg/t].A1 [kg/t].C1 - EUR.C1C2
110013,814,611,5
2100,7512,610,67,4
31,512,89,56,6
4103,014,1the 10.17,2

Example 6.

Performance in respect of dehydration was assessed using cationic and anionic polymers corresponding to example 1, and the fibrous mass with a high conductivity and a method corresponding to example 2. The results shown in table 5.

Table 5.
no test.Dosage C1 [kg/t].The dosage As [kg/t].Time dehydration [sec].
   A2 - EUR.A5A6
1200of 31.8of 31.8of 31.8
2201,031,027,528,8
3202,028,022,024,4
4204,023,816,519,5
5206,023,014,0 18,3

Example 7.

Performance in respect of dehydration was assessed using cationic and anionic polymers corresponding to example 1, and the fibrous mass with a high conductivity and a method corresponding to example 2. The results shown in table 6.

Table 6.
No.DosageDosageTime dehydration [sec].
test.C3 [kg/t].[Kg/t].A5A6
12015,815,8
220,2513,813,3
320,513,212,9
420,75the 13.413,1
521,013,513,3

Example 8.

Performance in relation to dewatering and retention was assessed using cationic and anionic polymers corresponding to example 1, and the fibrous mass with a standard conductivity and techniques relevant Primera and 3. The results shown in table 7.

Table 7.

no test.Dosage [kg/t].Dosage A7 [kg/t].Time dehydration /turbidity [s]/ [NTU].
   C2 - EUR.C1
125022,0 / 4923,4 / 43
225222,1 / 5016,3 / 40
325421,2 / 4614,3 / 40

Example 9.

Performance in respect of dehydration was assessed using cationic and anionic polymers and ATS corresponding to example 1, and fibrous masses with an average conductivity and methods, corresponding to example 2. The results shown in table 8.

Table 8.
no test.Dosage ATS [kg/t].Dosage [kg/t].Dosage A7 [kg/t].Time dehydration [sec].
    C3 - EUR.C3/td>
133120,811,0
2331,517,99,3
333214,77,9

Example 10.

Performance in relation to dewatering and retention was assessed using cationic and anionic polymers and ATS corresponding to example 1, and fibrous masses with an average conductivity and methods corresponding to examples 2 and 3. The results shown in table 9.

Table 9.
no test.Dosage ATS [kg/t].Dosage [kg/t].Dosage A8 [kg/t].Time dehydration/turbidity [s]/[NTU].
    C3 - EUR.C3
133221,4/4911,1/40
233317,4/469,3/40
3334the 15.6/488,9/4

Example 11.

Performance in respect of dehydration was assessed using cationic and anionic polymers corresponding to example 1, and the fibrous mass with a standard conductivity and methods, corresponding to example 2. The results shown in table 10.

Table 10.
no test.Dosage [kg/t].Dosage A8 [kg/t].Time dehydration/turbidity [s]/[NTU].
C2 - EUR.C1
125123,0/4720,8/44
225222,6/5019,0/43
325422,8/4918,8/45
425622,6/4916,3/40
525822,1/5015,5/42

1. Method of making paper from an aqueous suspension containing cellulosic fibres, and optional fillers, which comprises adding to the suspension separately cationic organic polymer, there is a corresponding one or more aromatic groups, and anionic polymer having one or more aromatic groups, and anionic polymer is chosen from polymers produced by the mechanism of stepwise growth molecules, polysaccharides and aromatic polymers found in nature, and their modifications, forming and dewatering the suspension on the grid, with the proviso that, if the anionic polymer is a polymer obtained by the mechanism of stepwise growth molecules, they will not be anionic condensation polymer based on malminkartano acid.

2. Method of making paper from an aqueous suspension containing cellulosic fibres, and optional fillers, which comprises adding to the suspension separately cationic organic polymer having one or more aromatic groups, and anionic polymer having one or more aromatic groups, forming and dewatering the suspension on the grid, with the proviso that the anionic polymer will not form anionic polystyrenesulfonate or anionic condensation polymer based on malminkartano acid.

3. The method according to claim 1 or 2, characterized in that the cationic polymer is a cationic polysaccharide.

4. The method according to any one of claims 1 to 3, characterized in that the cationic polymer is a cationic starch.

5. The method according to claim 1 or 2, is great for the present, however, what cationic polymer is a vinyl polymer obtained by polyprionidae.

6. The method according to any one of claims 1, 2 or 5, characterized in that the cationic polymer is a polymer based on acrylamide.

7. The method according to any one of claims 1 to 6, characterized in that the mass-average molecular weight cationic polymer exceeds about 1000000.

8. The method according to any one of claims 1 to 7, characterized in that the cationic polymer has a benzyl group.

9. The method according to any one of claims 1 to 8, characterized in that the anionic polymer is an anionic condensation polymer based on a benzene or on the basis of naphthalene.

10. The method according to any one of claims 1 to 9, characterized in that the anionic polymer is produced from one or more aromatic compounds selected from phenyl, phenol, naphthalene, naphthol, their derivatives and mixtures thereof.

11. The method according to any one of claims 1 to 8, characterized in that the anionic polymer is a polymer-based lignin.

12. The method according to any one of claims 1 to 11, characterized in that the anionic polymer is chosen from extracts of tannin, sulfonated lignins, the condensation polymers based on benzosulfimide acid, condensation polymers based benzosulfimide, condensation polymers based on cellsurvival acid, condensate is the R polymer-based cellsurface, condensation polymers based on naphtalenesulfonic acid, condensation polymers based naphthalenesulfonate, condensation polymers based on phenolsulfonic acid, condensation polymers based on phenolsulfonate and mixtures thereof.

13. The method according to any one of claims 1 to 8, characterized in that the anionic polymer is chosen from anionic polyurethanes.

14. The method according to any one of claims 1 to 13, characterized in that the mass-average molecular weight anionic polymer is in the range from 500 to 1000000.

15. The method according to any one of claims 1 to 14, characterized in that the cationic polymer is added in amounts of 0.005 to 2 wt.% calculated on a dry suspension.

16. The method according to any one of claims 1 to 15, characterized in that the anionic polymer is added in amounts of 0.005 to 1.5 wt.% calculated on a dry suspension.

17. The method according to any one of claims 1 to 16, characterized in that it further includes adding to the suspension a low molecular weight cationic organic polymer.

18. The method according to any one of claims 1 to 17, characterized in that the conductivity of the suspension, at least equal to 2.0 MSM/see

19. The method according to any one of claims 1 to 18, characterized in that it further includes a recirculation of the circulating water and the introduction of from 0 to 30 tons of fresh water per ton of produced paper.

Priorities for the item is meters and features:

16.11.2000 according to claims 1 and 2 except for the sign “provided that, if the anionic polymer is a polymer obtained by the mechanism of stepwise growth is not anionic condensation polymer based on malminkartano acid”, which takes precedence 02.08.2001;

16.11.2000 on PP-10, 13-19;

16.11.2000 indicated in paragraph 12, except sulfonated lignins, which have priority 02.08.2001;

02.08.2001 on item 11.



 

Same patents:

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Papermaking process // 2244776

FIELD: paper industry.

SUBSTANCE: invention relates to technology of manufacturing paper from aqueous suspension containing cellulose fibers and optional fillers. Process comprises separately adding to suspension cationic processing polymer with one or several aromatic groups and anionic polymer with one or several aromatic groups. The latter is selected from polymers prepared according to stepped molecule growth mechanism, naturally occurring polysaccharides and aromatic polymers and modifications thereof, provided that, if anionic polymer is polymer prepared according to stepped molecule growth mechanism, then it cannot be anionic condensation polymer based on melaminesulfonic acid. Another condition that could be alternatively fulfilled is that anionic polymer is not anionic polystyrenesulfonate or anionic condensation polymer based on melaminesulfonic acid. Suspension is then molded into sheet and dehydrated on screen.

EFFECT: improved dehydration and/or retention during making of paper from all types of fibrous pulps, including those with high content of salts, and increased strength of dry paper.

19 cl, 10 tbl, 11 ex

FIELD: mining industry and mechanical engineering.

SUBSTANCE: the invention is dealt with methods of production of a paper, in particular, with its smoothing. The water suspension containing cellulose fibers and optional fillers (i) add the sizing dispersion containing a sizing agent and a polymer including one or several aromatic groups and (ii) a sizing promoter containing a polymer intercalating one or several aromatic groups. Mould and dry the produced suspension. The sizing dispersion and sizing promoter are added to the water suspension separately. The invention ensures improvement of the process of sizing the cellulose fibers having a high conductivity.

EFFECT: the invention ensures improvement of the process of sizing the cellulose fibers having a high conductivity.

41 cl, 6 tbl, 6 ex

FIELD: pulp-and-paper industry.

SUBSTANCE: method involves preparing cellulose suspension; providing flocculation and draining of suspension on netted surface; molding and drying of resultant sheet. Flocculation of suspension is provided by introducing of water-soluble polymer selected from the group consisted of polysaccharide and synthetic polymer with characteristic viscosity of at least 4 deciliter/g. Repeated flocculation procedure is provided by adding of system including silicon-containing material and water-soluble polymer. According to one of versions, silicon-containing material is added before or simultaneously with water-soluble polymer. According to other version, water-soluble polymer is of anionic kind of polymers, which is added before introduction of silicon-containing material.

EFFECT: improved draining and holding procedures facilitating adequate conditions for paper and cardboard molding procedure.

18 cl, 2 tbl, 4 ex

FIELD: paper-and-pulp industry.

SUBSTANCE: process comprises preparation of paper pulp, flocculation of pulp, drainage of pulp on the screen to form sheet, and subsequent drying of sheet. Flocculation involves flocculation system including clay and water-soluble anionic branched polymer. The latter is prepared using water-soluble anionic ethylenically-unsaturated monomer or monomer mixture and ramification-forming agent. Polymer is characterized by intrinsic viscosity above 1.5 dl/g and/or Brookfield viscosity in salt solution above about 2.0 mPa·s, rheological oscillation delta tangent value at 0.005 Hz above 0.7, and/or reduced viscosity in deionized water at least thrice exceeding reduced viscosity in salt solution of corresponding nonbranched polymer obtained in absence of ramification-forming agent.

EFFECT: improved drainage, retention, and formation process.

20 cl, 10 tbl, 8 ex

FIELD: paper-and-pulp industry.

SUBSTANCE: process comprises preparation of paper pulp, flocculation of pulp, drainage of pulp on the screen to form sheet, and subsequent drying of sheet. Flocculation involves flocculation system including water-soluble anionic branched polymer and silicon-containing material. Polymer is prepared using water-soluble anionic ethylenically-unsaturated monomer or monomer mixture and ramification-forming agent. Polymer is characterized by intrinsic viscosity above 1.5 dl/g and/or Brookfield viscosity in salt solution above about 2.0 mPa·s, rheological oscillation delta tangent value at 0.005 Hz above 0.7, and/or reduced viscosity in deionized water at least thrice exceeding reduced viscosity in salt solution of corresponding nonbranched polymer obtained in absence of ramification-forming agent.

EFFECT: improved drainage, retention, and formation process.

14 cl, 1 dwg, 6 tbl, 6 ex

FIELD: paper-and-pulp industry.

SUBSTANCE: : process comprises preparation of paper pulp, flocculation of pulp, shear force-involving mechanical treatment of pulp, second flocculation of pulp, drainage of pulp on the screen to form sheet, and subsequent drying of sheet. Flocculation is carried out by adding water-soluble optionally having intrinsic viscosity above 3 dl/g. Polymer is further characterized by oscillation delta tangent value at 0.005 Hz above 1.1.

EFFECT: improved drainage and retention on moving screen, and formation process.

10 cl, 1 dwg, 4 tbl, 4 ex

FIELD: paper-and-pulp industry.

SUBSTANCE: process comprises manufacturing sized paper in presence of sizing substance and water-soluble amphoteric promoter resin, which is obtained via polymerization of a monomer including at least one polymerizable cationic amine monomer and at least one polymerizable organic acid and wherein molar percentage of cationic amine constitutes at least 25% of monomers in amphoteric promoter resin and molar percentage of organic acid units constitutes at least 25% of monomers in amphoteric promoter resin, while whiteness loss is below 0.5 TAPPI units as compared to whiteness of composition obtained without promoter resin.

EFFECT: improved sizing characteristics due to optical bleacher added and with excellent preservation of whiteness.

3 cl, 12 dwg, 2 tbl, 19 ex

FIELD: paper making.

SUBSTANCE: composition for manufacture of paper has flocculating cationic polymeric retention means, phenol resin, and polyethylene oxide. Cationic polymeric retention means is liquid aqueous cationic polymer dispersion free of solvent and oil phase and having viscosity of from 2,000 to 20,000 mPa˙s at concentration of 1%. Cationic polymeric retention means may be added into composition in conjunction with phenol resin or separately from it at other point. It may be also used for preliminary treatment of filler which is to be further added to composition.

EFFECT: increased extent of retention and dehydration of composition for manufacture of paper, high quality of paper sheets and reduced manufacture costs.

11 cl, 4 dwg, 5 tbl, 3 ex

FIELD: textiles, paper.

SUBSTANCE: method comprises grinding the cellulose to a given degree of fineness and preparing suspensions of the ground cellulose and calcium carbonate. Then, the suspension of calcium carbonate is processed by the modifying agent, the suspensions of fibre and the processed calcium carbonate are mixed to obtain the fibre mass. The fibre mass is added to the sizing component and the auxiliary material to produce paper pulp. The modifying agent is used as nanopowders of oxide or hydroxides of aluminium or their mixtures with its amount of 0.5-2.5% by weight of calcium carbonate. The sizing component is used as alkyl ketene dimer, and the auxiliary material is used as cationic starch in an amount of 0.3-0.4 and 0.5-0.7%, based on dry substance in the paper pulp respectively.

EFFECT: increase in degree of retention of filler.

2 cl, 5 ex, 1 tbl

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