JP5382705B2 - Paper manufacturing method - Google Patents

Description

The present invention relates to a method for producing paper, and more specifically, a vinyl polymerization cationic or amphoteric water-soluble polymer and / or a polycondensation cationic substance having a weight average molecular weight of 1,000 or more and less than 5 million in a papermaking raw material before paper making. After adding (A) and treating the paper defect-generating substance in the papermaking raw material, a vinyl polymerized ionic water-soluble polymer (B) having a charge inclusion ratio of 50% to 90% represented by the following definition: The present invention relates to a paper manufacturing method characterized by adding and making paper.

Various dissolved substances or fine particulate substances exist in papermaking water. Some of these substances are derived during pulp production and others are derived during waste paper manufacture. That is, as derived from pulp production, lignin sulfonate, lignin degradation product, wood extract, cellulose derivative (eg, hemicellulose) and the like. In addition, the sizing agent, dispersant, dye, fluorescent bleaching agent, coating binder, wetting agent, sodium silicate, and the like are derived from the production of used paper. Furthermore, humic acid and calcium components are mixed in industrial water to be introduced.

Of these, soluble or hydrophilic anionic components called anionic trash, namely white pigments, dispersants, modified starches, carboxymethylcellulose, lignin sulfonate, lignin degradation products, hemicellulose, etc. Yield rate and drainage can be improved to a considerable extent by treatment with a conductive polymer substance. However, hydrophobic components that do not dissolve in water, that is, wood extracts, sizing agents, coating binders, and the like have little adverse effects when dispersed as fine colloidal particles in the papermaking raw material. However, these colloids have a low surface charge and are weakly anionic and dissociated or may not be dissociated and are basically unstable substances. Accordingly, the colloid is destroyed and coarsened by an organic or inorganic cationic substance added to suppress temperature, shear, pH, or pitch disturbance. As a result, the surface is sticky, so if the charge is only adjusted, they will be re-attached to the surface of the wire, felt, roller or dryer when they are baked into the paper, and the size will exceed a certain level. When it grows up, it adheres to the paper being manufactured and causes problems such as defects. Further, these hydrophobic components may be treated with a cationic water-soluble polymer substance to coarsen the particle system. In such a case, the above-described obstacles are more noticeably generated, and a treatment agent such as a cationic water-soluble polymer substance may have an adverse effect, so care must be taken.

Various proposals have also been made for drugs for preventing the damage caused by the hydrophobic components. In the bleaching process alkali extraction of pulp production, as a method of removing the pitch in the pulp derived from the raw wood, a copolymer of a water-soluble unsaturated carboxylic acid and a hydrophobic monomer is used as a pulp slurry after bleaching. It is disclosed that it is added before entering the next alkali extraction tower (Patent Document 1). In addition, as a method for preventing troubles caused by various pitches derived from wood or waste paper, polystyrene sulfonic acid (salt) and polyisoprene sulfonic acid (salt) are dissolved in shower water in a place where the pitch easily adheres, It is described that the toner is supplied by a shower, an injection nozzle, a water doctor or the like (Patent Document 2). Further, as a water-soluble polymer having an amidine structural unit, Patent Document 3 discloses a production method synthesized from N-vinylformamide and an acrylonitrile copolymer. However, these drugs are not sufficient to prevent the damage caused by sticky hydrophobic components, and in particular, the problem of requiring reconsideration on the surfaces of wires, felts, rollers or dryers remains. .

The term “pitch” refers to various natural hydrophobic organic resins of low and medium molecular weight, and refers to precipitates during pulp manufacturing and papermaking processes caused by these resins. Pitch refers to fatty acids, resin acids, their insoluble salts, and esters of fatty acids with glycerol (such as triglycerides) and sterols. Hydrophobic fine particles such as sizing agents, waxes and coating binders derived from used paper manufacture are called “sticky”, but may be used without being distinguished from “pitch”. These compounds exhibit temperature-dependent viscosity, tackiness, and cohesive strength to the extent they are characteristic. They may precipitate alone or together with insoluble inorganic salts, fillers, fibers, defoaming ingredients, coating binders, and the like.

As long as these anionic trash, micropitch, and turbidity components are present in the papermaking raw material in a fine state, they are rarely generated as defects in the papermaking, but are agglomerated by stirring, aeration, pH change, and chemical addition. Cause defects.
Various reports have been made on the factors that cause the growth and coarsening of the pitch in the papermaking system to become causative substances. First, the raw material chest, the mixing chest, the machine chest, and the seed box The other is a white water circulation system in which the seed material is diluted with circulating white water to become an inlet, and the white water is further circulated. In other words, it is agglomerated between raw material chests, mixed chests, machine chests, and seed boxes to form particles of a certain size. These slightly coarsened particles do not settle on the pulp fibers in the white water circulation system. It is presumed that the pitch that has been converted into a fine powder or filler becomes a coarse sticky material and becomes stuck on the wet paper in the paper machine to cause a defect.

In the actual papermaking field, in addition to these so-called pitch control agents, a fan pump that dilutes the papermaking raw material with white water using a yield improver that is a high molecular weight water-soluble polymer for the purpose of improving the yield on the wire. Add to the front, before the screen or after passing through the screen. That is, the yield improver is based on the reason that it is a high molecular weight water-soluble polymer. Furthermore, in the conventional yield improvement, the defect-causing substances treated with the pitch control agent may be collected again by agglomeration, which may be a source of defects on the finished paper. In some cases, a crosslinkable water-soluble polymer is used, but the currently used one does not have a very high degree of crosslinking, and the cohesiveness to the papermaking raw material is not much different from that of a non-crosslinkable water-soluble polymer. Examples of applying water-insoluble particles or an emulsion type partially containing water-insoluble particles as a yield improver can be found in Patent Document 4 or Patent Document 5. There are no examples of application as a retention improver.
JP 11-256490 A JP-A-11-189987 JP-A-5-192513 JP-A 63-235596 JP-A 61-293510

The problem of the present invention is to collect the defect-causing substances treated by the pitch control agent again by an agglomeration action, to prevent the occurrence of defects on the formed paper, and even when added to the papermaking raw material after passing through the screen, The papermaking method should be examined in which mixing takes place quickly and formation preparation problems are also good.

As a result of repeated studies to solve the above problems, the present inventor has discovered a manufacturing method as described below. That is, the invention of claim 1 of the present invention provides a vinyl polymerized cationic or amphoteric water-soluble polymer and / or a polycondensed cationic substance having a weight average molecular weight of 1,000 or more and less than 5,000,000 to a papermaking raw material before papermaking. After adding A) and treating the paper defect-generating substance in the papermaking raw material, the vinyl-polymerized ionic water-soluble polymer (B) having a charge inclusion ratio of 50% to 90% represented by the following definition 1) The vinyl polymerized ionic water-soluble polymer (B) contains 5 to 50 mol% of a monomer represented by the following general formula (1) and / or the following general formula (2), and the following general formula ( 3) Manufacture of paper comprising adding a vinyl-polymerized ionic water-soluble polymer (B) prepared by polymerizing a monomer mixture containing 0 to 30 mol% of the monomer represented by 3) Is the method.

Definition 1) a water-soluble cationic polymer and amphoteric a and cationic monomer and an anionic monomer the difference of the body copolymerization ratio is positive water-soluble cationic or amphoteric high content child <br/> charge encapsulation efficiency [ %] = (1−α / β) × 100
α is a titration amount obtained by titrating a water-soluble cationic polymer or an amphoteric water-soluble polymer aqueous solution adjusted to pH 4.0 with acetic acid with a potassium polyvinyl sulfonate aqueous solution. β is a water-soluble cationic polymer or an amphoteric water-soluble polymer aqueous solution adjusted to pH 4.0 with acetic acid, and an aqueous polyvinyl sulfonate potassium solution is used to neutralize the charge of the water-soluble cationic polymer or amphoteric water-soluble polymer. A titration amount obtained by adding a sufficient amount to perform, and then subtracting the titration amount titrated with an aqueous polydiallyldimethylammonium chloride solution from the blank value. Here, the blank value is a titration amount obtained by titrating a potassium polyvinylsulfonate aqueous solution with a polydiallyldimethylammonium chloride aqueous solution when no water-soluble cationic polymer or amphoteric water-soluble polymer aqueous solution was added.

General formula (1)
R ₁ is hydrogen or a methyl group, R ₂ and R ₃ are alkyl groups having 1 to ₃ carbon atoms, or benzyl group, R ₄ is hydrogen, an alkyl group having 1 to 3 carbon atoms, or a benzyl group. But it ’s okay. A represents O or NH, B represents an alkylene group having 2 to 4 carbon atoms, and X ₁ ⁻ represents an anion.

General formula (2)
R ₅ and R _{6 each} represent hydrogen or a methyl group, R ₇ and R ₈ each represent an alkyl group having 1 to 3 carbon atoms or a benzyl group, and X ₂ ⁻ represents an anion.
General formula (3)
R ₉ is hydrogen or CH ₂ COOY ₂ , R ₁₀ is hydrogen, methyl group or COOY ₂ , Q is SO ₃ ⁻ , C ₆ H ₄ SO ₃ ⁻ , CONHC (CH ₃ ) ₂ CH ₂ SO ₃ ⁻ , C ₆ H ₄ COO ⁻ or COO ⁻ , and Y ₁ and Y ₂ each represent hydrogen or a cation.

The invention of claim 2 is characterized in that the vinyl polymerization cationic or amphoteric water-soluble polymer and / or polycondensation cationic substance (A) is one or more selected from the following (a) to (d): The paper manufacturing method according to claim 1, wherein the weight average molecular weight is 1,000 or more and less than 5 million .
(A) Water-soluble copolymer having polyvinylamine and polyvinylamine repeating unit (b) Polyamine / epihalohydrin condensate containing quaternary ammonium base (c) 2-aminoalkylene (meth) acrylate polymer and 2-aminoalkylene Water-soluble copolymer having (meth) acrylate repeating unit (d) Polyethyleneimine modified product containing polyethyleneimine and quaternary ammonium base

In the invention of claim 3, the vinyl polymerized ionic water-soluble polymer (B) contains 5 to 50 mol% of a monomer represented by the following general formula (1) and / or the following general formula (2). Produced by polymerizing a monomer mixture containing 0 to 30 mol% of the monomer represented by the general formula (3) and 0.0005 to 0.0050 mol% of the crosslinkable monomer with respect to the total amount of the monomers. a paper manufacturing method according to claim 1, characterized in that to those were.
General formula (1)
R ₁ is hydrogen or a methyl group, R ₂ and R ₃ are alkyl groups having 1 to ₃ carbon atoms, or benzyl group, R ₄ is hydrogen, an alkyl group having 1 to 3 carbon atoms, or a benzyl group. But it ’s okay. A represents O or NH, B represents an alkylene group having 2 to 4 carbon atoms, and X ₁ ⁻ represents an anion.

General formula (2)
R ₅ and R _{6 each} represent hydrogen or a methyl group, R ₇ and R ₈ each represent an alkyl group having 1 to 3 carbon atoms or a benzyl group, and X ₂ ⁻ represents an anion.
General formula (3)
R ₉ is hydrogen or CH ₂ COOY ₂ , R ₁₀ is hydrogen, methyl group or COOY ₂ , Q is SO ₃ ⁻ , C ₆ H ₄ SO ₃ ⁻ , CONHC (CH ₃ ) ₂ CH ₂ SO ₃ ⁻ , C ₆ H ₄ COO ⁻ or COO ⁻ , and Y ₁ and Y ₂ each represent hydrogen or a cation.

The invention according to claim 4 is the paper manufacturing method according to claim 1, wherein the defect generating substance of the paper is one or more selected from anionic trash, micropitch, and turbidity component.

The invention of claim 5 is characterized in that the vinyl polymerized ionic water-soluble polymer (B) contains 5 to 50 mol% of the monomer represented by the general formula (1) and / or the general formula (2), An aqueous solution of a monomer mixture containing 0 to 30 mol% of the monomer represented by the general formula (3) and 0.0005 to 0.0050 mol% of the crosslinkable monomer based on the total amount of the monomers. A water-in-oil emulsion obtained by emulsifying and polymerizing a water-immiscible organic liquid with a surfactant so as to form a continuous phase as a dispersed phase. The method for producing paper according to 1 or 2.

In other words, in the raw material chest, mixed chest, machine chest, and about 3 to 4% of the raw material system up to the seed box, the obstructive agent that causes defects in the paper in the papermaking raw material becomes particles of a certain size. By adding the water-soluble polymer (A) to the coarsened particles, the coarsening is prevented. Further, after adding white water, by adding the vinyl polymerized ionic water-soluble polymer (B), the slightly coarsened particles are transferred to a papermaking machine without further coarsening, thereby improving the yield on the wire. Achieve.

In the conventional non-crosslinkable water-soluble polymer, since a huge floc as a raw material for paper production is generated, obstacle substances are also coarsened at that time, and these are encapsulated in the huge floc and cause defects after papermaking. On the other hand, a vinyl polymerization type ionic water-soluble polymer having a charge inclusion rate of 50% or more and 90% or less represented by the definition used in the present invention is:
It is a water-soluble polymer with a high degree of cross-linking and exhibits the following characteristic aggregation action.

That is, when the crosslinkable water-soluble polymer is added to the sludge, it adsorbs to the suspended particles and acts as an adhesive between the particles, resulting in aggregation of the particles. At this time, it is presumed that since it is in a “dense packed” molecular form, it binds to the particle surface at multiple points to form a tighter and stronger floc. Bonding at multiple points is excellent in the ability to adsorb to suspended particles, and therefore there is little unadsorbed water-soluble polymer. In addition, the cationic group present inside the molecule in a round shape does not contribute to charge neutralization of the suspended particles, but acts as a molecule with an apparently low degree of cationization, and is redispersed by cationic saturation. Will be less. As a result, a strong flock with a small size is formed, which has a positive effect on the paper texture. In addition, since no giant floc is formed, the obstacle-generating substance is not coarsened, and defects after papermaking are suppressed.

Low molecular weight water-soluble polymers such as polycondensation systems are used to reduce the substances that cause obstacles.
The action is considered to be a coagulation action. “Coagulation” is a little different from the above-mentioned aggregation action, and most of the role is to neutralize the surface charge of hydrophilic substances or particles. Absent. Therefore, depending on the coagulant, large flocs are not generated, and only fine flocs are generated.
The crosslinkable polymer having a charge encapsulation rate of 50% or more and 90% or less used in the present invention has a property close to a particle shape because of its relatively high degree of crosslinking, and is adsorbed on the surface of the obstacle generating substance. Neutralize charge. This is considered to be the same effect as the coagulant as a result. Therefore, in the present invention, the use of a crosslinkable water-soluble polymer having a charge inclusion rate of 50% or more and 90% or less is good not only for yield improvement or formation improvement, but also for control of substances that cause obstacle action. It is thought that it works.

First, the ionic water-soluble polymer (B) having a charge inclusion rate of 50% to 90% will be described. The charge inclusion rate is defined as follows. That is, definition) Water-soluble cationic polymer charge inclusion rate [%] = (1−α / β) × 100
α is a titration amount obtained by titrating a water-soluble cationic polymer adjusted to pH 4.0 with acetic acid with an aqueous potassium polyvinyl sulfonate solution. β is added to a water-soluble cationic polymer aqueous solution adjusted to pH 4.0 with acetic acid in an amount sufficient to neutralize the charge of the water-soluble cationic polymer, and then polydiallyldimethylammonium Titration volume obtained by subtracting the titration volume titrated with an aqueous chloride solution from the blank value. Here, the blank value is a titration amount obtained by titrating a potassium polyvinylsulfonate aqueous solution with a polydiallyldimethylammonium chloride aqueous solution when no water-soluble cationic polymer aqueous solution was added.

That is, it can be said that a water-soluble polymer having a high charge encapsulation rate is a water-soluble polymer with increased crosslinking, and a water-soluble polymer having a low charge encapsulation rate is a water-soluble polymer having little crosslinking. The reason for this is explained as follows. A linear water-soluble polymer has a substantially “stretched” shape in a dilute solution. On the other hand, the crosslinkable water-soluble polymer has a rounded particle shape in the solution, and the ionic group present inside the particle is unlikely to appear on the outside and reacts slowly with the opposite charge. It is thought to happen.

The titration amount α is obtained by dropping a potassium polyvinyl sulfonate aqueous solution having an opposite charge onto a crosslinkable water-soluble cationic polymer as a sample, and then “surface” (particulate surface portion) of the water-soluble cationic polymer. Means that an ionic electrostatic reaction is performed on the ionic group present in

Next, potassium polyvinyl sulfonate having an opposite charge more than the amount sufficient to neutralize the theoretical charge amount of the crosslinkable water-soluble cationic polymer was added, and after sufficient reaction time, excess polyvinyl sulfone was added. Potassium acid is titrated with an aqueous diallyldimethylammonium chloride solution. Separately, the potassium polyvinyl sulfonate solution was titrated with a diallyldimethylammonium chloride aqueous solution without adding a crosslinkable water-soluble cationic polymer, a blank value was obtained, and a crosslinkable water-soluble cationic polymer was added from the blank value. If this is the case, this value is β. The β value is considered to correspond to the theoretical charge amount calculated from the chemical composition of the crosslinkable water-soluble cationic polymer. That is, since a large amount of opposite charges exist with respect to the crosslinkable cationic water-soluble polymer, it is considered that the electrostatic neutralization reaction is performed not only on the surface cationic charges but also on the internal charges. If the degree of crosslinking is high, α is smaller than β, and the (1-α / β) value is larger than 1 and the charge inclusion rate is large (that is, the degree of crosslinking is high).

In the present invention, in order to produce the crosslinkable water-soluble cationic polymer (B) having the charge inclusion rate as described above, the crosslinkable monomer is used as a structural modifier in the total amount of monomers during or after the polymerization. 0.0005 to 0.0050 mol%, preferably 0.0008 to 0.002 mol%. Examples of the crosslinkable monomer include N, N-methylenebis (meth) acrylamide, triallylamine, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and dimethacrylic acid. Acid-1,3-butylene glycol, polyethylene glycol di (meth) acrylate, N-vinyl (meth) acrylamide, N-methylallylacrylamide, glycidyl acrylate, polyethylene glycol diglycidyl ether, acrolein, glyoxal, vinyltrimethoxysilane In this case, the crosslinking agent is more preferably a water-soluble polyvinyl compound, and most preferably N, N-methylenebis (meth) acrylamide. Use of a chain transfer agent such as sodium formate or isopropyl alcohol in combination is also effective as a method for adjusting the crosslinkability.

The cationic monomer used to produce the ionic water-soluble polymer (B) having a charge encapsulation rate of 50% or more and 90% or less is a monomer represented by the following general formula (1) and / or Using the monomer represented by the general formula (2) and the monomer represented by the following general formula (3), 0.0005 to 0.0050 mol% of the crosslinkable monomer is essential with respect to the total amount of monomers. Is a polymerized monomer mixture. Examples of the cationic monomer represented by the general formula (1) include (meth) acryloyloxyalkyl quaternary ammonium salts such as (meth) acryloyloxyethyltrimethylammonium chloride and (meth) acryloyloxyethyldimethylbenzylammonium chloride. (Meth) acryloyloxyalkyl tertiary amine salts such as (meth) acryloyloxy-2-hydroxypropyltrimethylammonium bromide are (meth) acryloyloxyethyldimethylamine sulfate, (meth) acryloyloxypropyldimethylamine hydrochloride, etc. is there. Examples of the (meth) acryloylaminoalkyl quaternary ammonium salt include (meth) acryloylaminopropyltrimethylammonium chloride, (meth) acryloylaminopropyltrimethylammonium methyl sulfate, and the like. Examples of the (meth) acryloylamino (hydroxy) alkyl tertiary amine salt include (meth) acryloylaminoethyldimethylamine hydrochloride.

General formula (1)
R ₁ is hydrogen or a methyl group, R ₂ and R ₃ are alkyl groups having 1 to ₃ carbon atoms, or benzyl group, R ₄ is hydrogen, an alkyl group having 1 to 3 carbon atoms, or a benzyl group. But it ’s okay. A represents O or NH, B represents an alkylene group having 2 to 4 carbon atoms, and X ₁ ⁻ represents an anion.
General formula (2)
R ₅ and R _{6 each} represent hydrogen or a methyl group, R ₇ and R ₈ each represent an alkyl group having 1 to 3 carbon atoms or a benzyl group, and X ₂ ⁻ represents an anion.
General formula (3)
R ₉ is hydrogen or CH ₂ COOY ₂ , R ₁₀ is hydrogen, methyl group or COOY ₂ , Q is SO ₃ ⁻ , C ₆ H ₄ SO ₃ ⁻ , CONHC (CH ₃ ) ₂ CH ₂ SO ₃ ⁻ , C ₆ H ₄ COO ⁻ or COO ⁻ , and Y ₁ and Y ₂ each represent hydrogen or a cation.

Examples of the anionic monomer used for producing the water-soluble amphoteric polymer used in combination include vinyl sulfonic acid, vinyl benzene sulfonic acid or 2-acrylamido 2-methylpropane sulfonic acid, methacrylic acid, acrylic acid, itaconic acid, For example, maleic acid or p-carboxystyrene.

In the case of producing an ionic water-soluble polymer having a charge encapsulation rate of 50% or more and 90% or less, a nonionic monomer may be copolymerized, and examples thereof include the following. That is, acrylamide, N, N-dimethylacrylamide, vinyl acetate, acrylonitrile, methyl acrylate, 2-hydroxyethyl (meth) acrylate, diacetone acrylamide, N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, acryloylmorpholine Etc.

The mol% of the cationic monomer in these ionic water-soluble polymers is 5 to 50 mol%, preferably 10 to 50 mol%, and most preferably 10 to 30 mol%. Further, the mol% of the cationic monomer in the amphoteric polymer is 5 to 50 mol%, preferably 10 to 50 mol%, and most preferably 15 to 30 mol%. The mol% of the anionic monomer is 3 to 30 mol%, preferably 5 to 30 mol%, and most preferably 5 to 20 mol%. The molecular weight is 3 to 30 million in terms of weight average molecular weight, preferably 10 to 30 million, and most preferably 1500 to 30 million.

The product form of the water-soluble cationic polymer or the water-soluble amphoteric polymer in the present invention can be implemented in any form such as powder, water-in-oil emulsion, and aqueous dispersion in salt solution. A polymer obtained by drying a water-in-oil emulsion polymerized in the presence of a crosslinkable monomer as a structural modifier is a crosslinkable water-soluble polymer having excellent performance, and can be said to be the most preferred form.

The crosslinkable water-soluble polymer is preferably obtained by drying a water-in-oil emulsion. Water-in-oil emulsions are ionic monomers, or ionic monomers, copolymerizable monomers, and crosslinkable added in a molar ratio that keeps the water-soluble polymer produced with these monomers. Monomer mixture containing monomer, water, oily substance comprising at least water-immiscible hydrocarbon, at least one surfactant having an amount effective for forming water-in-oil emulsion and HLB Are mixed and vigorously stirred to form a water-in-oil emulsion and polymerize.

Examples of oily substances composed of hydrocarbons used as dispersion media include paraffins, mineral oils such as kerosene, light oil, and middle oil, or hydrocarbon-based synthetics having characteristics such as boiling point and viscosity substantially in the same range as these. An oil or a mixture thereof may be mentioned. As content, it is the range of 20 mass%-50 mass% with respect to the water-in-oil type emulsion whole quantity, Preferably it is the range of 20 mass%-35 mass%.

Examples of at least one surfactant having an amount effective to form a water-in-oil emulsion and HLB are HLB 1-8 nonionic surfactants, specific examples of which include sorbitan monooleate Sorbitan monostearate, sorbitan monopalmitate and the like. The addition amount of these surfactants is 0.5 to 10% by mass, preferably 1 to 5% by mass, based on the total amount of the water-in-oil emulsion.

The water-in-oil emulsion thus polymerized is spray-dried without adding a hydrophilic surfactant called a phase inversion agent, or directly put into a dryer in the emulsion state and dried, and then pulverized into a powder. Since the crosslinkable polymer is easily insolubilized in the drying process, the emulsion is suitable for the production of the crosslinkable polymer because it is relatively easy to dry.

These various polymerizations are carried out under a nitrogen atmosphere, with a polymerization initiator such as 2,
Initiation of water-soluble azo polymerization such as 2'-azobis (amidinopropane) dihydrochloride or 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride A water-soluble redox polymerization initiator such as an agent or a combination of ammonium persulfate and sodium hydrogen sulfite is added, and radical polymerization is performed with or without stirring.

Examples of the vinyl polymerization cationic or amphoteric water-soluble polymer and / or polycondensation cationic substance (A) having a weight average molecular weight of 1,000 or more and less than 5 million are as follows.
(A) Water-soluble copolymer having polyvinylamine and polyvinylamine repeating unit (b) Polyamine / epihalohydrin condensate containing quaternary ammonium base (c) 2-aminoalkylene (meth) acrylate polymer and 2-aminoalkylene Water-soluble copolymer having (meth) acrylate repeating unit (d) Polyethyleneimine modified product containing polyethyleneimine and quaternary ammonium base

The water-soluble copolymer having a polyvinylamine and a polyvinylamine repeating unit (a) will be described. A method for producing a polyvinylamine water-soluble polymer is disclosed in JP-A-6-65329. The water-soluble copolymer having a polyvinylamine and a polyvinylamine repeating unit used in the present invention can be easily obtained by modifying a formyl group in the N-vinylformamide polymer or copolymer. Alternatively, it can be synthesized by subjecting an acrylamide polymer to a Hofmann reaction. That is, in the case of N-vinylformamide polymer, the molar ratio of N-vinylformamide to other copolymerizable monomers is usually a mixture of 20:80 to 95: 5, preferably 40:60 to 95. : 5, particularly preferably a 40:60 to 90:10 mixture in the presence of a radical polymerization initiator.

Since the formyl group is hydrolyzed with an acid or alkali, a part of the copolymerized monomer is also hydrolyzed to generate a carboxyl group in many cases. Therefore, it is convenient when acrylonitrile or the like is copolymerized. Other acrylamide, methyl acrylate, ethyl acrylate, npropyl acrylate, 2-hydroxyethyl acrylate, ethyl methacrylate, npropyl methacrylate, isopropyl methacrylate, nbutyl methacrylate, isobutyl methacrylate, methacrylic acid-sec Examples include butyl and 2-hydroxyethyl methacrylate. Since these monomers generate anionic groups, the molar ratio in the copolymer is preferably less than 20 mol%.

A polymerized or copolymerized N-vinylformamide copolymer can be used as a new vinylamine by modification in the form of a solution or dispersion as it is, or after dilution or dehydration or drying by a known method to form a powder. It can be a copolymer. As the modification method used in this case, any method of modifying the N-vinylformamide copolymer under basic and acidic conditions can be used. As a preferable modification method of the N-vinylformamide copolymer, there are a method of acid hydrolysis in water, a method of acid hydrolysis in a hydrophilic solvent such as alcohol containing water, alcoholysis under acidic conditions, and formyl. Examples thereof include a method of modifying the group while separating it as a formate ester, and particularly preferred is alcoholysis under acidic conditions. By this method, a vinylamine copolymer substantially free of carboxyl groups can be obtained.

As the modifier used for acid modification, any compound that acts on strong acid can be used, for example, hydrochloric acid, bromic acid, hydrofluoric acid, sulfuric acid, nitric acid, phosphoric acid, sulfamine. Examples include acids and alkane sulfonic acids. The usage-amount of modifier | denaturant is suitably selected according to the target modification | denaturation rate from the range of 0.1-2 times mole normally with respect to the formyl group in a polymer. Further, the denaturation reaction is usually carried out at 40 to 100 ° C. The weight average molecular weights of these water-soluble copolymers having polyvinylamine and polyvinylamine repeating units are 1,000 to 5,000,000.

The polyamine / epihalohydrin condensate containing the quaternary ammonium base of (b) is ethylenediamine, diethylenetriamine, triethylenetetramine, pentaethylenehexamine, hexamethylenediamine, dimethylaminoethylamine, dimethylaminopropylamine, hexamethylenediamine, 1,3. -Diaminobutane, hexamethylenediamine and the like. These polyamines may be used in combination with aliphatic monoamines, that is, ammonia, monomethylamine, monoethylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, mono-, di- or tri-ethanolamine. However, when these amines are used in combination, primary or secondary amino groups are hardly formed. That is, in the present invention, it is presumed that the primary or secondary amino group is effective in the adsorption action to the hydrophobic substance. As a result, since the prevention effect of the adhesion-impairing substance that is the gist of the present invention is lowered, the ratio to be used in combination is preferably 30% by mass or less. The polyamine / epihalohydrin condensate may be a product obtained by reacting the above-mentioned polyamine or ammonia and an aliphatic monovalent amine with an epihalohydrin, or first reacting an aliphatic monovalent amine with an epihalohydrin in the first step of the reaction. A product having a quaternary ammonium base, a condensate having reactivity at both ends or at one end, and reacting with a polyamine in the second stage of the reaction to increase the molecular weight may be used. The molecular weight of the polyamine / epihalohydrin condensate is about 1,000 to about 100,000 in terms of weight average molecular weight.

A preferred example of the polyamine / epihalohydrin condensate is a condensate formed by reacting 0.5 mol to 3.0 mol of epihalohydrin with respect to 1 mol of amino group in the polyamine molecule of the following general formula (4). . By reacting at such a ratio, a condensate having a plurality of types of amino groups among primary, secondary, tertiary or quaternary ammonium salt bases can be produced. In addition, it is presumed that the primary or secondary amino group is effective for the adsorption action to the hydrophobic substance. Therefore, it is preferable that active hydrogen is present in the condensate. Therefore, it is preferable to leave the hydrogen atom of the raw material amine by adjusting the ratio of epihalohydrin. Therefore, the condensation produced by reacting 0.5 mol to 1.5 mol of epihalohydrin with 1 mol of amino group in the polyamine molecule, preferably 0.5 mol to 1.5 mol of epihalohydrin with respect to 1 mol of amino group in the polyamine molecule. It is preferable that it is a thing.
General formula (4)
R ₁ and R ₂ are hydrogen or an alkyl group having 1 to 3 carbon atoms, Z is an alkylene group having 2 to 6 carbon atoms, and n is an integer of 1 to 6.

The (c) 2-aminoalkylene (meth) acrylate polymer used in the present invention and the water-soluble copolymer having a 2-aminoalkylene (meth) acrylate repeating unit are an acrylic cation having a primary amino group in the molecule. (Co) polymer. This polymer can be produced by homopolymerization or copolymerization of an acrylic monomer having a primary amino group. As a method for producing a monomer, acid hydrolysis of acryloxyalkyl ketimine or acryloxyalkylaldimine as disclosed in Japanese Patent Publication No. 38-8310, US Patent Publication 3,037,969 (1962), or US Patent It can be taken out in the form of a salt of the corresponding acid by acid hydrolysis of a reaction product of ethyleneimine and (meth) acrylic acid as described in JP-A-3,336,358 (1967). Examples of the monomer include organic acids such as 2-aminoethyl acrylate, 2-aminoethyl methacrylate, 3-aminopropyl acrylate, 2-aminopropyl methacrylate. The salt of inorganic acid can be raised.

Since it is an acrylic monomer, good copolymerization with various monomers is possible. For example, the nonionic monomers (meth) acrylamide, N, N-dimethylacrylamide, vinyl acetate, acrylonitrile, methyl acrylate, 2-hydroxyethyl (meth) acrylate, diacetone acrylamide, N-vinyl pyrrolidone, N -Vinylformamide, N-vinylacetamide, etc. are mentioned, and it is also possible to carry out copolymerization in combination with one or more of nonionic monomers. An example of the most preferred nonionic monomer is acrylamide. It is also possible to copolymerize an anionic monomer, in which case it is amphoteric. Examples of the anionic monomer include bivinyl sulfonic acid, styrene sulfonic acid, acrylamido 2-methylpropane sulfonic acid, acrylic acid, methacrylic acid, itaconic acid, maleic acid and the like. Further, it can be copolymerized with a monomer containing a tertiary amino group or a quaternary ammonium group. Examples of the tertiary amino group-containing monomer include dimethylaminoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylamide. Examples of the quaternary ammonium group-containing monomer include (meth) acryloyloxyethyltrimethylammonium chloride, (meth) acryloyloxy, which is a quaternized product of the tertiary amino group-containing monomer with methyl chloride or benzyl chloride. 2-hydroxypropyltrimethylammonium chloride, (meth) acryloylaminopropyltrimethylammonium chloride, (meth) acryloyloxyethyldimethylbenzylammonium chloride, (meth) acryloyloxy 2-hydroxypropyldimethylbenzylammonium chloride, (meth) And acryloylaminopropyldimethylbenzylammonium chloride. Copolymers comprising these quaternary ammonium group-containing monomers, nonionic monomers, and primary amino group-containing acrylic monomers, which are essential components in the cationic polymer used in the present invention, are also included in the present invention. It can be used in a papermaking method.

The weight average molecular weights of these 2-aminoalkylene (meth) acrylate polymers and water-soluble copolymers having 2-aminoalkylene (meth) acrylate repeating units are 1,000 to 100,000. Further, the product form of the cationic water-soluble polymer used in the present invention is not particularly limited, and any water-in-oil emulsion polymerization method, oil-in-water dispersion polymerization method, salt-in-water dispersion polymerization method, aqueous solution polymerization method, etc. After obtaining a product synthesized by this polymerization method, a cationic water-soluble copolymer suitable for the method of use is obtained.

The water-soluble polymer (d) polyethyleneimine and the polyethyleneimine-modified product used in the present invention are polyethyleneimine or polypropyleneimine, but are practically polyethyleneimine. A molecular weight of 1,000 or more can be used for the purpose of the present invention. That is, it is preferably 1,000 or more and 100,000 or less, and more preferably 10,000 or more and 100,000 or less. Similarly, in the case of a modified polyalkyleneimine, the molecular weight after modification is preferably 1,000 or more and 100,000 or less, and preferably 10,000 or more and 100,000 or less.

As a modification method, for example, polyalkyleneimine modified by crosslinking with epichlorohydrin, ethylene glycol diglycidyl ether or the like can also be used. In addition, in the dimethylamine and epichlorohydrin condensate, if the reaction ratio of epichlorohydrin is excessively charged to about 1.05 to 1.2, a terminal reactive condensate is formed, which is converted into the polyalkyleneimine. If used as a modifier, a polyalkyleneimine-modified product containing a quaternary ammonium base can be produced.

The water-soluble polymer of the present invention is composed of sticky precipitates generated during the pulp manufacturing process described above, that is, pitch, or hydrophobic fine particles such as sizing agents, waxes and coating binders derived from deinked waste paper manufacturing. It is excellent in the effect of reducing the adhesion of the sticky substance such as sticky to the dryer, or the defects on the surface of the finished paper after drying (stains due to the aggregate of the sticky substance). Since the adhesive substance is originally a hydrophobic substance, the primary amino group in the water-soluble polymer according to the present invention, that is, (a) polyvinylamine or (c) 2-aminoalkylene (meth) acrylate polymer, (b It is likely to be adsorbed to hydrophobic substances by the action of primary or secondary amino groups in polyamine / epihalohydrin condensates and (d) primary or secondary amino groups in pothiethyleneimine, and is thought to be effective in preventing hindering action. It is done.

The ion equivalent value of these water-soluble polymers (A) (a) to (d) at pH 3 is 5.0 to 23 meq / g, respectively. The reason why the water-soluble polymer (A) has a high ion equivalent value is mainly to neutralize the surface charge of a substance that causes the generation of paper defects. Therefore, it is preferably 6.0 to 23 meq / g, and more preferably 7.0 to 23 meq / g.

EXAMPLES The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

In the examples, prototypes shown in Tables (1) and (2) below were used.
(Table 1) Water-soluble vinyl polymer and polycondensation cationic substance (A)
AAM; acrylamide, DETA; diethylenetriamine, ECH; epichlorohydrin, DPA; dimethylaminopropylamine,

(Table 2) Vinyl polymerization type ionic water-soluble polymer (B)
DMQ: acryloyloxyethyltrimethylammonium chloride DMC: methacryloyloxyethyltrimethylammonium chloride AAM: acrylamide, AC: acrylic acid,

Defect of paper of the present invention using DIP (deinked waste paper, pH 6.80, dry solid content after filtration with Whatman filter paper No. 41, 4.15% by mass) made from magazine waste paper collected from the site of deinked waste paper The generation suppression method was tested. That is, after adding 0.04% by mass of the vinyl polymerization water-soluble polymer and the polycondensation cationic substance (A) Sample-1 to Sample-6 shown in Table 1 per dry papermaking raw material and stirring for 60 seconds, Diluted with white water (pH 6.65, dry solid content 0.30% by mass) collected from the papermaking field (concentration after dilution 1.0% by mass), vinyl polymerization ionic water-soluble polymer (B) S- 0.02% by mass of 1 was added and stirred for 60 seconds. After that, Whatman filter paper no. The turbidity of the filtrate was measured with HACH 2100P type, and the cation demand of anion trash was measured with BTG PCD-03 type.

The micropitch is measured using a paperman raw material mixed with white water and treated with a water-soluble polymer. The filtrate filtered at 41 was collected on a counting chamber (hemacytometer) having a thickness of 0.2 mm and observed with an optical microscope 1200 times. I took several still images while shifting the focus vertically. The same operation was repeated at five or more different locations on the counting chamber. Using image processing software (Media Cybernetics, inc. IMAGE-PRO PLUS Ver. 5.0), a still image of a microscopic image is captured, and the RGB value range setting is set to an R value (0-190) G value (0-130) B The target particles were extracted by adjusting the value (0-156), and the number of the extracted particles was measured.

Further, the pressure-sensitive adhesive that could agglomerate and become a defect in the formed paper was measured as follows. That is, a papermaking raw material mixed with white water and treated with a water-soluble polymer is filtered for 5 minutes with a circular filter paper having a diameter of 90 mm (holding particles of Whatman No. 41, 20 to 25 μm or more), and the filter paper is peeled off from the raw material after filtration. Use a wet sheet that has been peeled off. The measurement surface is the surface of the peeled wet sheet that does not face the filter paper. The filtration amount is collected by calculating the concentration of the target raw material so that the diameter is 90 mm and the basis weight is 150 g / m ² . The side of the wet sheet that does not face the filter paper is used as a measurement surface, and the wet sheet is attached to a SUS plate, and the above adhesive is transferred to a medium. At this time, a thick filter paper is put on the surface opposite to the surface of the wet sheet attached to the SUS plate (thickness: 0.1 mm), set in a press machine, and pressurized at 410 KPa for 5 minutes.

Next, the SUS plate with the wet sheet attached is set on a rotary dryer and heated at 105 ° C. for 6 minutes. At this time, the SUS plate is set on the cylinder side of the rotary dryer, and the transferred wet sheet side is set on the felt side.

After heating, 20 arbitrary locations on the adhesion surface (90 mm diameter) from the wet sheet on the SUS plate are selected, photographed with a digital camera using a stereomicroscope, and stored in a computer as an image. Then, the target particle | grains were extracted by adjusting the range setting of RGB value using the image processing software similar to the case where a micropitch was measured. The extracted deposits are extracted again under the optimum conditions of size, long / short radius ratio, number of holes, and hole area, and the sticky pitch is discriminated from the fiber content and other deposits. About the extracted particle | grains, the adhesive pitch total area and total number were measured, and it converted per 1 m < ² >. A similar test was conducted for the vinyl polymerized ionic water-soluble polymer (B) S-2 to S-4. The above results are shown in Tables 3 and 4.

(Comparative Example 1)
The same procedure as in Example 1 was performed for vinyl polymerization ionic water-soluble polymer (B) Comparative C-1.
The results are shown in Table 3.

(Comparative Example 2)
The same procedure as in Example 1 was performed for vinyl polymerization type ionic water-soluble polymer (B) Comparative C-2. The results are shown in Table 4.

(Table 3)

(Table 4)

Yield rate measurement test was performed with a Brit dynamic jar tester. Use 200 mesh wire. The raw material used was a newsprint papermaking raw material having a solid content concentration of 1.0% by mass and containing 35.4% as solid for Ash, such as light calcium carbonate. The physical properties of the papermaking raw materials are pH 7.2, Whatman No. The required amount of cation using a PCD-03 model of 41 filter paper filtrate manufactured by Mutech is 0.004 meq / L. It is assumed that after stirring for 20 seconds at a stirring speed of 1500 rpm, 150 ppm of prototypes 1, 3, 3, 5, and 7 of the synthesis examples are added to the solid content of the paper and added after passing through the screen. After stirring for 10 seconds at a stirring speed of 1500 rpm, the filtrate was collected, and ADVANTEC, No. After filtration with two filter papers, SS was measured, and the total yield was measured. Then, the filter paper was ashed at 525 ° C. for 2 hours, and the ash yield was measured. The results are shown in Table 5.

(Comparative Example 4) Using the same papermaking raw material as in Example 1, 200 ppm of Samples 1, 3, 3, 5, 7, and 8 of Synthesis Examples were added to the solid content of the paper. Assuming that it is added before the screen, after stirring for 30 seconds at a stirring speed of 1500 rpm, the filtrate was collected and ADVANTEC, After filtration with two filter papers, SS was measured, and the total yield was measured. Then, the filter paper was ashed at 525 ° C. for 2 hours, and the ash yield was measured. The results are shown in Table 5.

(Comparative Example 5) Using the same papermaking raw material as in Example 1, 150 ppm of Comparative Synthesis Example, Prototype-8, was added to the solid content of the paper, and it was added after passing through the screen. After stirring for 10 seconds, the filtrate was collected and ADVANTEC, No. 4 was collected. After filtration with two filter papers, SS was measured, and the total yield was measured. Then, the filter paper was ashed at 525 ° C. for 2 hours, and the ash yield was measured. The results are shown in Table 5.

(Table 5)

Claims (5)

The paper in the papermaking raw material is prepared by adding a vinyl polymerized cationic or amphoteric water-soluble polymer and / or a polycondensation cationic substance (A) having a weight average molecular weight of 1,000 or more and less than 5 million to the papermaking raw material before paper making. Is a vinyl polymerized ionic water-soluble polymer (B) having a charge inclusion rate of 50% or more and 90% or less represented by the following definition 1) after treating the defect-generating substance : The polymer (B) has a monomer represented by the following general formula (1) and / or the following general formula (2) in an amount of 5 to 50 mol%, and a monomer represented by the following general formula (3) in an amount of 0 to A method for producing paper, comprising adding a vinyl-polymerized ionic water-soluble polymer (B) produced by polymerizing a monomer mixture containing 30 mol% and making paper.

Definition 1) a water-soluble cationic polymer and amphoteric a and cationic monomer and an anionic monomer the difference of the body copolymerization ratio is positive water-soluble cationic or amphoteric high content child <br/> charge encapsulation efficiency [ %] = (1−α / β) × 100
α is a titration amount obtained by titrating a water-soluble cationic polymer or an amphoteric water-soluble polymer aqueous solution adjusted to pH 4.0 with acetic acid with a potassium polyvinyl sulfonate aqueous solution. β is a water-soluble cationic polymer or an amphoteric water-soluble polymer aqueous solution adjusted to pH 4.0 with acetic acid, and an aqueous polyvinyl sulfonate potassium solution is used to neutralize the charge of the water-soluble cationic polymer or amphoteric water-soluble polymer. A titration amount obtained by adding a sufficient amount to perform, and then subtracting the titration amount titrated with an aqueous polydiallyldimethylammonium chloride solution from the blank value. Here, the blank value is a titration amount obtained by titrating a potassium polyvinylsulfonate aqueous solution with a polydiallyldimethylammonium chloride aqueous solution when no water-soluble cationic polymer or amphoteric water-soluble polymer aqueous solution was added.

General formula (1)
R ₁ is hydrogen or a methyl group, R ₂ and R ₃ are alkyl groups having 1 to ₃ carbon atoms, or benzyl group, R ₄ is hydrogen, an alkyl group having 1 to 3 carbon atoms, or a benzyl group. But it ’s okay. A represents O or NH, B represents an alkylene group having 2 to 4 carbon atoms, and X ₁ ⁻ represents an anion.

General formula (2)
R ₅ and R _{6 each} represent hydrogen or a methyl group, R ₇ and R ₈ each represent an alkyl group having 1 to 3 carbon atoms or a benzyl group, and X ₂ ⁻ represents an anion.
General formula (3)
R ₉ is hydrogen or CH ₂ COOY ₂ , R ₁₀ is hydrogen, methyl group or COOY ₂ , Q is SO ₃ ⁻ , C ₆ H ₄ SO ₃ ⁻ , CONHC (CH ₃ ) ₂ CH ₂ SO ₃ ⁻ , C ₆ H ₄ COO ⁻ or COO ⁻ , and Y ₁ and Y ₂ each represent hydrogen or a cation. The vinyl polymerization cationic or amphoteric water-soluble polymer and / or polycondensation cationic substance (A) is at least one selected from the following (a) to (d), and the weight average molecular weight is 1000 or more, The paper manufacturing method according to claim 1, wherein the paper manufacturing method is less than 5 million .
(A) Water-soluble copolymer having polyvinylamine and polyvinylamine repeating unit (b) Polyamine / epihalohydrin condensate containing quaternary ammonium base (c) 2-aminoalkylene (meth) acrylate polymer and 2-aminoalkylene Water-soluble copolymer having (meth) acrylate repeating unit (d) Polyethyleneimine modified product containing polyethyleneimine and quaternary ammonium base In the vinyl polymerization type ionic water-soluble polymer (B), the monomer represented by the following general formula (1) and / or the following general formula (2) is 5 to 50 mol%, and the following general formula (3): It is produced by polymerizing a monomer mixture containing 0 to 30 mol% of the represented monomer and 0.0005 to 0.0050 mol% of the crosslinkable monomer with respect to the total amount of the monomers. The paper manufacturing method according to claim 1, characterized in that:
General formula (1)
R ₁ is hydrogen or a methyl group, R ₂ and R ₃ are alkyl groups having 1 to ₃ carbon atoms, or benzyl group, R ₄ is hydrogen, an alkyl group having 1 to 3 carbon atoms, or a benzyl group. But it ’s okay. A represents O or NH, B represents an alkylene group having 2 to 4 carbon atoms, and X ₁ ⁻ represents an anion.

General formula (2)
R ₅ and R _{6 each} represent hydrogen or a methyl group, R ₇ and R ₈ each represent an alkyl group having 1 to 3 carbon atoms or a benzyl group, and X ₂ ⁻ represents an anion.
General formula (3)
R ₉ is hydrogen or CH ₂ COOY ₂ , R ₁₀ is hydrogen, methyl group or COOY ₂ , Q is SO ₃ ⁻ , C ₆ H ₄ SO ₃ ⁻ , CONHC (CH ₃ ) ₂ CH ₂ SO ₃ ⁻ , C ₆ H ₄ COO ⁻ or COO ⁻ , and Y ₁ and Y ₂ each represent hydrogen or a cation. The paper manufacturing method according to claim 1, wherein the defect-generating substance of the paper is at least one selected from anionic trash, micropitch, and turbidity component. In the vinyl polymerization ionic water-soluble polymer (B), the monomer represented by the general formula (1) and / or the general formula (2) is contained in an amount of 5 to 50 mol%, and the general formula (3). An aqueous solution of a monomer mixture containing 0 to 30 mol% of the represented monomer and 0.0005 to 0.0050 mol% of the crosslinkable monomer with respect to the total amount of the monomer as a dispersed phase, The paper according to claim 1 or 2, wherein the water-in-oil emulsion obtained is dried after the immiscible organic liquid is emulsified and polymerized with a surfactant to form a continuous phase. Manufacturing method.