JP2017066581A - Manufacturing method of paper and yield improver kit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of paper capable of enhancing fixability of an additive assistant for paper making to a pulp component without deteriorating formation physical property of a resulting paper and capable of reducing added amount of the additive assistant for paper making and a yield improver kit.SOLUTION: The is provided a manufacturing method of paper for paper making by adding an anionic polymer compound after adding a cationic polymer compound to a pulp-containing aqueous slurry, where the anionic polymer compound has viscosity average molecular weight of over 35,000,000 and anionic charge density of 0.6 to 4.0 meq/g. There is provided a yield improver kit containing a first additive containing the cationic polymer compound and a second additive containing the anionic polymer compound.SELECTED DRAWING: None

Description

  The present invention relates to a paper manufacturing method and a yield improving kit, and in particular, improves the fixability of the paper additive to the pulp component without impairing the physical properties of the resulting paper, and the paper additive The present invention relates to a paper manufacturing method and a yield improver kit capable of reducing the amount of addition of.

  In paper production, the yield and drainage are improved in order to improve productivity and operability as paper machine speeds up, and to improve whiteness, opacity, printability and strength of the resulting paper. Additives and fillers for papermaking such as agents, paper strength agents and sizing agents are used.

  For example, a cationic or amphoteric acrylamide copolymer is used as the first step in the papermaking process in order to improve yield, drainage, squeezing and productivity, without impairing the texture of the paper. A paper manufacturing method (Patent Document 1) is proposed in which a yield improver is added and a water-soluble polymer having a molecular weight lower than that of the yield improver is added as the second step. In this method, agglomerates of pulp components (hereinafter referred to as “floc”) can be produced to increase the cohesiveness of the flocs. However, when the shear is applied after passing through the screen, the flocs become too fine and are not suitable. As a result, there is a problem that the uniform shape is obtained, resulting in insufficient yield and loss of texture, and poor fixability of the papermaking additive to the pulp component.

  In recent years, due to environmental problems such as global warming and effective use of resources, the increased blending of used paper and fillers has further increased, making it difficult to demonstrate the effects of paper additive additives. The added amount is seen to increase, and the pitch processing is insufficient, which causes a paper surface defect due to machine contamination. For this reason, not only the improvement of the texture and yield properties but also the fixability of the papermaking additive to the pulp component has become important.

JP 2009-280925 A

  First, the present inventors have added a retention agent containing an ultrahigh molecular weight, low charge density, cationic or anionic polymer compound to a pulp-containing aqueous slurry, thereby improving operability and paper in the papermaking process. The present inventors have found that it is possible to produce a paper having a high content of used paper and filler and uniformly dispersed without impairing the physical properties of the paper. However, the anionic trash and impurities contained in the charge state in the system and various pulps and white water (water recycled in the paper manufacturing process) are not common in all systems, and are additive aids for papermaking, In particular, there was room for improvement in the fixability of paper strength agents and sizing agents to pulp components.

  Therefore, the object of the present invention is to improve the fixability of the paper additive additive to the pulp component without impairing the physical properties of the resulting paper, and to reduce the amount of the paper additive additive added. An object of the present invention is to provide a method for producing a simple paper and a yield improver kit.

  As a result of further earnest studies to solve the above-mentioned problems, the present inventors have a viscosity average molecular weight exceeding 35 million after adding a cationic polymer compound first, and 0.6 to By adding an anionic polymer compound having an anionic charge density of 4.0 meq / g, the fixability of the paper additive additive component to the pulp component is improved, and the amount of the paper additive additive added is reduced. It was found that it was possible to make paper with high quality without deteriorating the physical properties of the texture, and the present invention was completed based on this finding.

  That is, the paper manufacturing method of the present invention is a paper manufacturing method in which a cationic polymer compound is added to a pulp-containing aqueous slurry and then an anionic polymer compound is added, and the anionic polymer is made. The compound has a viscosity average molecular weight exceeding 35 million and an anionic charge density of 0.6 to 4.0 meq / g.

  In the paper manufacturing method of the present invention, the cationic polymer compound preferably has a viscosity average molecular weight of 10 million or less. Furthermore, in the paper manufacturing method of the present invention, the cationic polymer compound preferably has a cationic charge density of 0.4 to 12.0 meq / g.

  The yield improver kit of the present invention is a yield improver kit comprising a first additive containing a cationic polymer compound and a second additive containing an anionic polymer compound, the anionic polymer compound Has a viscosity average molecular weight exceeding 35 million and an anionic charge density of 0.6 to 4.0 meq / g.

  In the yield improver kit of the present invention, the cationic polymer compound preferably has a viscosity average molecular weight of 10 million or less. Furthermore, in the yield improver kit of the present invention, the cationic polymer compound preferably has a cationic charge density of 0.4 to 12.0 meq / g.

  The yield improver kit of the present invention is preferably used after the first additive is added and then the second additive is added.

  According to the present invention, the paper capable of improving the fixability of the papermaking additive to the pulp component and reducing the amount of the papermaking additive added without impairing the physical properties of the resulting paper. The production method and the yield improver kit can be provided.

  Hereinafter, embodiments of the present invention will be described in detail.

  First, the paper manufacturing method of the present invention will be described. The present invention relates to a paper manufacturing method for making paper by adding an anionic polymer compound to a pulp-containing aqueous slurry and then adding an anionic polymer compound, wherein the viscosity of the anionic polymer compound exceeds 35 million. The present invention relates to a method for producing paper having an average molecular weight and an anionic charge density of 0.6 to 4.0 meq / g.

  Here, the viscosity average molecular weight is a viscosity average molecular weight in terms of polyvinyl alcohol measured by an intrinsic viscosity method. Specifically, the intrinsic viscosity is measured and converted using an Ubbelohde viscometer (trade name “Viscometer Ubellode” manufactured by Shibata Kagaku Co., Ltd.).

  The anionic charge density refers to the number of equivalents (meq / g) of anionic charges in the monomer unit constituting the polymer compound. Furthermore, the cation charge density described later refers to the equivalent number (meq / g) of cation charge in the monomer unit constituting the polymer compound. Specifically, in the case of an anionic polymer, methyl glycol chitosan solution (manufactured by Wako Pure Chemical Industries, Ltd., trade name “methyl glycol chitosan solution (N / 200)”) is added, and excess polyvinyl sulfate ( This is a numerical value obtained by colloidal titration using a trade name “Polyvinyl Potassium Sulfate Titration Solution (N / 400)” manufactured by Wako Pure Chemical Industries, Ltd. In the case of a cationic polymer, polyvinyl potassium sulfate (Wako Pure Chemical Industries, Ltd.) The numerical value calculated | required by the colloid titration method using the product name "Polyvinyl potassium sulfate titrant (N / 400)" by the corporation | Co., Ltd. is pointed out.

  Hereinafter, the “cationic polymer compound”, “anionic polymer compound”, and “pulp-containing aqueous slurry” used in the paper manufacturing method of the present invention will be described.

<Cationic polymer compound>
The cationic polymer compound used in the present invention is not particularly limited in its charge density and chemical structure, and any of linear, branched and crosslinked types can be used, but the viscosity average molecular weight is 10 million. It is preferable to adjust to the following. When the viscosity average molecular weight of the cationic polymer compound exceeds 10 million, the cohesive force with respect to the pulp component is low and the pitch may be excessively aggregated. However, if the viscosity average molecular weight is too low, the fixability of pitch to the pulp component may be insufficient. The viscosity average molecular weight of the cationic polymer compound is more preferably in the range of 3 million to 8 million. By adjusting the viscosity average molecular weight of the cationic polymer compound to such a range, the dispersibility of the cationic polymer compound is improved, so that the synergistic effect with the anionic polymer compound used later is further increased, and pitch and The fixability with the additive for papermaking, especially sizing agent and paper strength agent, can be improved.

  The cationic charge density of the cationic polymer compound used in the present invention may be appropriately selected according to various components such as filler and pulp contained in the pulp-containing aqueous slurry, the physical properties of this slurry, etc. It is suitable to adjust to the range of 4 to 12.0 meq / g, preferably 1.0 to 10.0 meq / g, particularly preferably 1.5 to 7.0 meq / g. By adjusting to this range, the addition amount of the anionic polymer compound can be easily adjusted to a desired addition amount. In addition, even when the cationic polymer compound has an anionic group, it is suitable to adjust the cationic charge density to the same range.

  Specific examples of this cationic polymer compound include, for example, polyethyleneimine, dimethyldiallylamine-sulfur dioxide copolymer, polyacrylamide cation-modified product, polyaminoacrylic acid, and cationic monomer having a quaternary ammonium salt residue. Homopolymers or copolymers containing as structural units, epihalohydrin-alkylamine addition polymers and allylamine polymer salts or quaternary ammonium salts, dicyandiamide-formaldehyde-ammonium chloride condensation polymers, etc. A homopolymer or copolymer containing a cationic monomer having an ammonium salt residue as a structural unit is preferred.

  Examples of the cationic monomer having a quaternary ammonium salt residue constituting such a cationic polymer compound include 2- (meth) acryloyloxyethyltrimethylammonium chloride and 2- (meth) acryloyloxyethyldimethylbenzyl. Ammonium chloride, 2- (meth) acryloyloxyethyltriethylammonium chloride, 2- (meth) acryloyloxyethyldiethylbenzylammonium chloride, 3- (meth) acrylamidopropyltrimethylammonium chloride, 3- (meth) acrylamidopropyltriethylammonium chloride, 3- (Meth) acrylamidopropyldimethylbenzylammonium chloride, diallyldimethylammonium chloride, diallyldiethylammonium chloride Lido, 2- (meth) acryloyloxyethyltrimethylammonium sulfate, 2- (meth) acrylamidoethyltrimethylammonium chloride, 2- (meth) acryloyloxyethyltriethylammonium bromide, 3- (meth) acryloyloxypropyldimethylethylammonium chloride, 3-methacryloyloxy-2-hydroxypropyltrimethylammonium chloride, 3-methacryloyloxy-2-hydroxypropylmethyldiethylammonium chloride, 3-methacryloyloxy-2-hydroxypropyltrimethylammonium chloride, 2- (meth) acryloylaminoethyltrimethylammonium Chloride, 3- (meth) acryloylamino-2-hydroxypropyltrimethylan Niumukurorido, 2- (meth) acryloyl-aminoethyl trimethylammonium chloride and the like. Among these, a homopolymer or copolymer using 2- (meth) acryloyloxyethyltrimethylammonium chloride is preferable because the cationic charge density and the viscosity average molecular weight can be easily adjusted to desired values. The term (meth) acryloyl means acryloyl or methacryloyl.

  The cationic polymer compound may be a copolymer of the cationic monomer and a monomer copolymerizable therewith, for example, an ethylenically unsaturated compound. Examples of the ethylenically unsaturated compound constituting the copolymer include ethylenically unsaturated monocarboxylic acids and dicarboxylic acids, (meth) acrylic acid alkyl esters, aromatic vinyl compounds, unsaturated amide compounds, and unsaturated nitriles. Compounds and the like. Examples of such are (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate , Pentyl (meth) acrylate, 2-methylbutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, hexyl (meth) acrylate, ( Examples include 2-hydroxyhexyl (meth) acrylate, styrene, α-methylstyrene, (meth) acrylamide, N, N-dimethylacrylamide, N-methylolacrylamide, (meth) acrylonitrile and the like. Among them, (meth) acrylamide, particularly acrylamide is preferable because it is easily available and polymerization is easily performed. In addition, (meth) acrylic acid, maleic acid, fumaric acid, and itaconic acid are preferable, and (meth) acrylic acid is particularly preferable in that a cationic internal additive such as cationized starch can be efficiently incorporated. The term (meth) acryl means acryl or methacryl.

  When the cationic polymer compound is a copolymer, the content of the cationic monomer unit having a quaternary ammonium salt residue in the cationic polymer compound is preferably in the range of 3 mol% or more and less than 40 mol%. If the content of the cationic monomer unit is less than 3 mol%, it is difficult to obtain a desired cationic charge density, and if it is 40 mol% or more, it is difficult to improve the yield of pulp or filler, and the use of a conventional retention agent is used. It is difficult to reduce the amount. A more preferable blending ratio is in the range of 5 to 30 mol%. Further, when having an anionic monomer unit such as (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, the content of the anionic monomer unit in the copolymer is less than the cationic monomer unit, It is necessary to maintain the cationic nature of the copolymer. Specifically, the value obtained by subtracting the content of the anionic monomer unit from the content of the cationic monomer unit is preferably in the range of 3 mol% or more and less than 40 mol%, more preferably in the range of 5 mol% or more and less than 30 mol%. preferable. If the subtraction value is less than 3 mol%, it is difficult to obtain a desired cationic charge density, and if it is 40 mol% or more, it is difficult to improve the yield of pulp and filler, and it is also difficult to reduce the amount of a conventional retention agent used. .

（式中、Ｒ^１は水素原子または炭素数１〜５のアルキル基、Ｘ^１は塩素原子、臭素原子、硫酸残基、硝酸残基、有機カルボン酸残基または有機スルホン酸残基、ｎは重合度を示す）で表されるものである。 The salt of the allylamine polymer is represented by the following general formula [I],

Wherein R ¹ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, X ¹ is a chlorine atom, bromine atom, sulfuric acid residue, nitric acid residue, organic carboxylic acid residue or organic sulfonic acid residue, n is Represents the degree of polymerization).

In the salt of the allylamine polymer represented by the general formula [I], R ¹ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom, a methyl group, an ethyl group, a propyl group, or an isopropyl group. And X ¹ is a chlorine atom, a bromine atom, a sulfuric acid residue, a nitric acid residue, an organic carboxylic acid residue, or an organic sulfonic acid residue. Examples of allylamine polymer salts include polyallylamine hydrochloride, hydrobromide, sulfate, acetate, propionate, poly N-alkylallylamine, polymethylallylamine hydrochloride, poly Examples include ethylallylamine hydrochloride, polypropylallylamine hydrochloride, polyisopropylallylamine hydrobromide, and the like.

  The method for polymerizing the cationic polymer compound is not particularly limited, and any method such as a solution polymerization method, an emulsion polymerization method, a solid polymerization method and the like can be used. Examples of the polymerization initiator used here include water-soluble azo compounds and peroxides such as hydrogen peroxide, 2,2′-azobis (2-amidinopropane) dihydrochloride, water-soluble inorganic peroxides, and water-soluble compounds. And a combination of a water-soluble inorganic peroxide and an organic peroxide.

  Examples of the water-soluble inorganic peroxide include potassium persulfate and ammonium persulfate. Examples of the water-soluble reducing agent include a reducing agent used as a normal radical redox polymerization catalyst component soluble in water, such as ethylenediaminetetraacetic acid or a sodium salt or potassium salt thereof, and iron, copper, Complex compounds with heavy metals such as chromium, sulfinic acid or its sodium or potassium salt, L-ascorbic acid or its sodium, potassium or calcium salt, ferrous pyrophosphate, ferrous sulfate, ammonium ferrous sulfate Sodium sulfite, acidic sodium sulfite, sodium formaldehyde sulfoxylate and the like.

  On the other hand, examples of water-soluble organic peroxides include cumene hydroperoxide, p-cymene hydroperoxide, tert-butylisopropylbenzene hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, decalin hydroperoxide, tert-amyl hydro And hydroperoxides such as peroxide, tert-butyl hydroperoxide, and isopropyl hydroperoxide.

  In addition, as the emulsifier in this emulsion polymerization, an anionic surfactant or a combination thereof with a nonionic surfactant is usually used. The anionic surfactant or nonionic surfactant can be arbitrarily selected from those used in ordinary emulsion polymerization. Examples of such anionic surfactants include alkyl benzene sulfonate, alkyl sulfonate, alkyl sulfate ester salt, fatty acid metal salt, polyoxyalkyl ether sulfate ester salt, polyoxyethylene carboxylic acid ester sulfate ester salt, Examples thereof include polyoxyethylene alkylphenyl ether sulfate ester salts and succinic acid dialkyl ester sulfonate salts.

  Examples of nonionic surfactants include polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl ether glycerin borate ester, polyoxyethylene A compound having a polyoxyethylene chain in the molecule, such as ethylene alkyl ether phosphate ester, having surface activity and a compound in which the polyoxyethylene chain of the compound is replaced by a copolymer of oxyethylene and oxypropylene, Examples include sorbitan fatty acid ester, glycerin fatty acid ester, and pentaerythritol fatty acid ester.

  When the cationic polymer compound used in the present invention is synthesized by an emulsion polymerization method, for example, an ethylenically unsaturated compound and a cationic monomer are mixed at a predetermined ratio in an aqueous medium containing a polymerization initiator and an emulsifier. In general, by polymerizing at a temperature in the range of 30 to 80 ° C., an emulsion in which desired copolymer fine particles are uniformly dispersed can be obtained. The emulsion obtained by this method can be directly incorporated into the pulp-containing aqueous slurry as the cationic polymer compound of the present invention. If desired, the copolymer can be taken out as a solid by salting out or spray drying. May be added to the cellulose-containing suspension. The branched and crosslinked cationic polymers can be produced by using a polyfunctional compound having two or more reagent groups selected from the group consisting of a double bond, an aldehyde bond, and an epoxy bond in each polymerization method described above. A cross-linking agent constituted by a polyfunctional compound having two or more kinds of reagent groups selected from the group consisting of a branching agent or a double bond, an aldehyde bond or an epoxy bond (this cross-linking agent includes a polyvalent metal salt , An ionic cross-linking agent such as formaldehyde and glyoxal, and a covalent cross-linking agent copolymerizing with the monomer).

  The cationic polymer compound of the present invention may be used alone or in combination of two or more.

<Anionic polymer compound>
The anionic polymer compound used in the present invention is particularly limited to a chemical structure as long as it has a viscosity average molecular weight exceeding 35 million and an anionic charge density of 0.6 to 4.0 meq / g. Any of linear, branched and cross-linked types can be used.

  When the viscosity average molecular weight of the anionic polymer compound of the present invention exceeds 35 million, the synergistic effect with the cationic polymer compound provides a high fixing power of the papermaking additive for pulp components, Yield is also good. In particular, if the viscosity average molecular weight is 38 million or more, fine pulp fibers, fillers, and pitch components do not fall off under screen-like shear after floc formation, improving the yield and preventing paper machine contamination. can do. Moreover, if a viscosity average molecular weight is 80 million or less, it will become a favorable cohesion force and the desired physical property of paper can be obtained. Accordingly, the preferred viscosity average molecular weight of the anionic polymer compound of the present invention is in the range of 38 million to 80 million, and the particularly preferred upper limit of the viscosity average molecular weight is 70 million.

  Usually, it was thought that when a polymer compound having an ultrahigh molecular weight exceeding 35 million was added, the polymer compound was not uniformly dispersed in the pulp-containing aqueous slurry, and the physical properties of the texture were lowered. However, in the present invention, by setting the charge density of the anionic polymer compound in the range of 0.6 to 4.0 meq / g, the anionic polymer compound is uniformly dispersed in the pulp-containing aqueous slurry, and the size is large. Flocks with uniform height can be formed, and the physical properties of the texture are improved.

  That is, by adjusting the charge density of the anionic polymer compound used in the present invention within this range, the polymer compound has a molecular chain so that a good cohesive force can be obtained depending on the charge state in the molecule. Therefore, unlike the conventional polymer compound used as a yield agent, when interacting with the pulp fiber, the yield improvement effect can be exhibited without relying only on the electric charge. Therefore, it can be used regardless of the type of paper obtained, such as acidic paper or neutral paper, and even if the charge density in the pulp-containing aqueous slurry is high, it does not impair the physical properties of the paper and produces paper with a high yield. Can do. If the charge density is 0.6 meq / g or more and 4.0 meq / g or less, the yield, drainage, and physical properties can be improved, and the pitch amount can be reduced. The charge density is preferably in the range of 0.6 meq / g to 3.8 meq / g, particularly preferably 0.8 meq / g to 3.0 meq / g.

  Specific examples of the anionic polymer compound used in the present invention include, for example, a polymer having a water-soluble monomer containing acrylic acid or methacrylic acid as a structural unit, for example, sodium polyacrylate, polysodium methacrylate. And a copolymer of the water-soluble monomer and a structural unit copolymerizable therewith, for example, a structural unit such as acrylamide, methacrylamide, vinyl acetate, acrylonitrile, such as acrylamide-sodium acrylate copolymer, methacryl Examples include amide-sodium acrylate copolymers, and a homopolymer or copolymer containing sodium acrylate as a structural unit as an anionic monomer is particularly preferable.

  When the anionic polymer compound is a copolymer, the content of the water-soluble monomer in the anionic polymer compound is preferably in the range of 3 mol% or more and less than 40 mol%. If the content of the water-soluble monomer is less than this range, an effective anionic polymer compound cannot be obtained, and if it exceeds this range, it is not necessary to make a copolymer. A more preferable blending ratio is in the range of 5 to 30 mol%.

  The polymerization method of the anionic polymer compound of the present invention is not particularly limited, and any method such as a solution polymerization method, an emulsion polymerization method, a solid polymerization method, etc., may be used as in the polymerization method of the cationic polymer compound. Can do.

  The anionic polymer compound of the present invention may be used alone or in combination of two or more.

<Pulp-containing aqueous slurry>
The cationic polymer compound and the anionic polymer compound of the present invention are used by being added to the pulp-containing aqueous slurry. The pulp-containing aqueous slurry contains pulp components that have been conventionally used when producing paper. It does not restrict | limit especially as said pulp component, What was selected from 1 type, or 2 or more types of pulp chosen from mechanical pulp, chemical pulp, waste paper pulp, etc. can be used. Examples of mechanical pulp include groundwood pulp, refiner ground pulp, and thermomechanical pulp (TMP). Examples of the chemical pulp include kraft pulp such as hardwood kraft pulp (LBKP) and softwood kraft pulp (NBKP), sulfide pulp, alkaline pulp and the like. Examples of the used paper pulp include newspapers, pulp made of corrugated cardboard and shredder dust, and DIP subjected to deinking treatment. Although such a used paper pulp utilization rate tends to increase due to an increase in environmental awareness, virgin pulp can also be used in the present invention. Examples of the raw pulp include coniferous trees such as spruce, todomatsu and red pine, and broad-leaved trees such as beech, poplar and hippopotamus.

  The pulp-containing aqueous slurry of the present invention is a concentrated pulp slurry containing about 3 to 5% by mass of a pulp component, and then prepared to a concentration of 0.5 to 2.0% by mass with a diluent such as white water, The pulp component may be adjusted to 0.5 to 2.0 mass% without preparing the concentrated aqueous pulp slurry.

  The pulp-containing aqueous slurry may be added with conventional fillers and paper additive additives that are conventionally used when producing paper. The filler is not particularly limited, but calcium carbonate such as heavy calcium carbonate and light calcium carbonate, titanium oxide, silica, talc, clay, kaolin, magnesium carbonate, barium carbonate, zinc oxide, silicon oxide, aluminum hydroxide And inorganic fillers such as calcium hydroxide, magnesium hydroxide, zinc hydroxide, bentonite and white carbon, and organic fillers such as urea-formalin resin, polystyrene resin, melamine resin, phenol resin and fine hollow particles. A filler can be used individually or in combination of 2 or more types as appropriate. In addition, recycled fillers made from papermaking sludge, deinking floss, etc. can also be used. The addition amount of the filler may be appropriately selected depending on the type of paper to be produced, and is not particularly limited, but is in the range of 1 to 70% by mass with respect to the pulp component.

  Examples of the papermaking additive include a sulfuric acid band, a sizing agent, a paper strength agent, a drainage improver, a coagulant, a pitch control agent, a bulking agent, and a slime control agent.

  Next, the addition amount and addition position of the cationic polymer compound and the anionic polymer compound in the paper production method of the present invention will be described.

  The addition amount of the cationic polymer compound and the anionic polymer compound of the present invention is not particularly limited, but may be less than 1000 ppm for each pulp component. By adding the cationic and anionic polymer compound of the present invention to the pulp-containing slurry under such addition conditions, the physical properties of the pulp can be maintained without causing the pulp components to overcoagulate. The addition amount of the cationic and anionic polymer compound of less than 1000 ppm each means that the addition amount of the cationic and anionic polymer compound added to the pulp-containing aqueous slurry is less than 1000 ppm each with respect to the pulp component. Means that.

  The addition place of the cationic polymer compound and the anionic polymer compound of the present invention is not particularly limited as long as the cationic polymer compound can be added before the anionic polymer compound.

  Examples of the place where the cationic polymer compound of the present invention is added include a filter, a decker, an extractor, a thickener, a refiner, a stock chest, a DDR, a blender, a mixing chest, a machine chest, a seed box, a fan pump, a screen, an inlet, As well as piping connected to them. Among them, the space between the seed box and the fan pump or between the fan pump and the screen is preferable because dispersibility is increased and the pulp component can be uniformly fixed.

  The place where the anionic polymer compound is added is preferably from when the pulp-containing aqueous slurry passes through the seed box until it is fed to the inlet. Among these, before and after the screen, for example, between the fan pump and the screen or between the screen and the inlet is preferable because the interaction with the previously added cationic polymer compound is easy.

  The addition location and addition amount of the cationic and anionic polymer compounds in the paper production method of the present invention can be determined depending on whether the quality of the obtained paper is important or the cost is important. When making paper with an emphasis on the quality of the resulting paper, that is, the physical properties of the texture, the cationic polymer compound and the anionic polymer compound are added to the pulp-containing aqueous slurry before passing through the screen, and the respective concentrations of the polymer compound to the pulp component Is preferably added so as to be less than 1000 ppm, preferably 10 to 800 ppm. When a polymer compound is added at this position, it is easy to control the physical properties of the resulting paper. In addition, when making paper with an emphasis on cost, that is, with an emphasis on yield and reduction of the amount of the polymer compound of the present invention, the cationic polymer compound is added to the pulp-containing slurry after passing through the fan pump, after passing through the screen. It is preferable to add the anionic polymer compound to the pulp-containing aqueous slurry so that the concentration of each of the cation and anion polymer compound is less than 1000 ppm, preferably 10 to 800 ppm with respect to the pulp component. When the cationic and anionic polymer compound is added at this position, high yield is easily obtained although the addition amount is low.

  The addition ratio of the cationic polymer compound and the anionic polymer compound of the present invention may be appropriately selected from 1:99 to 99: 1 by mass ratio, preferably 1: 3 to 3: 1, more preferably Is 1: 2 to 2: 1.

  Next, the yield improver kit of the present invention will be described. The yield improver kit used in the present invention includes a first additive containing a cationic polymer compound and a second additive containing an anionic polymer compound, and the anionic polymer compound Has a viscosity average molecular weight exceeding 35 million and an anionic charge density of 0.6 to 4.0 meq / g.

  As the cationic polymer compound and the anionic polymer compound used in the yield improver kit of the present invention, the cationic polymer compound and the anionic polymer compound used in the paper manufacturing method of the present invention can be used.

  The properties of the first additive and the second additive used in the yield improver kit of the present invention are not particularly limited, and examples thereof include water-in-oil emulsions, powders, and solutions. .

  The type of paper produced by the paper production method and the yield improver kit of the present invention is not particularly limited. For example, coated paper, fine coated paper, high quality paper, medium quality paper, newspaper, PPC paper, liner Examples include base paper, core base paper, and white paperboard. According to the paper manufacturing method and the yield improver kit of the present invention, the sizing degree and paper strength can be improved, which is suitable for the production of high-quality paper and coated base paper.

  The paper manufacturing method and the yield improver kit of the present invention improve the fixability of the papermaking additive to the pulp component without impairing the physical properties of the resulting paper, and the amount of the papermaking additive added In addition, it is also possible to reduce or prevent the pitch component derived from waste paper, an anion trash contained in various pulps and white water, and contamination of the paper machine due to impurities. . Furthermore, if the viscosity average molecular weight of the cationic polymer compound of the present invention is adjusted to 10 million or less, the cationic polymer compound can be continuously added by mixing with dilution water in-line without providing a dissolution tank. . For this reason, only one dissolution tank is required to swell the anionic polymer compound of the present invention, which is advantageous in terms of management and cost as compared with a conventional two-agent yield system using two dissolution tanks. is there.

  Hereinafter, the paper production method and the yield improver kit of the present invention will be specifically described with reference to examples. However, the production method and the yield improver kit of the present invention are not limited to these examples.

(Preparation Example 1: Preparation of first additive A containing cationic polymer compound)
As a cationic polymer compound, a linear structure acrylamide-acryloyloxyethyltrimethylammonium chloride copolymer (“cationic A1 to A7” in the table) having viscosity average molecular weight and cationic charge density shown in Tables 1 to 4 below. A first additive A was prepared. The content ratio of the acrylamide unit and the acryloyloxyethyltrimethylammonium chloride unit in each cationic polymer compound is the molar ratio of each monomer, A-1 is 90:10, A-2 is 80:20, A-3. Was 80:20, A-4 was 70:30, A-5 was 80:20, A-6 was 80:20, and A-7 was 80:20. The viscosity average molecular weight and cation charge density were measured by the following methods.

(Preparation Example 2: Preparation of first additive B containing cationic polymer compound)
As a cationic polymer compound, a linear structure acrylamide-acryloyloxyethyltrimethylammonium chloride-acrylic acid copolymer having a viscosity average molecular weight and a cationic charge density shown in Tables 1 to 4 below (in the table, “cationic B-1 ]) Was used to prepare the first additive B. The content ratio of the acrylamide unit, the acryloyloxyethyltrimethylammonium chloride unit and the acrylic acid unit in the cationic polymer compound was 75: 20: 5 in terms of each monomer. The viscosity average molecular weight and cation charge density were measured by the following methods.

(Preparation Example 3: Preparation of anionic polymer compound-containing second additive)
As an anionic polymer compound, a linear acrylamide-sodium acrylate copolymer having a viscosity average molecular weight and an anionic charge density shown in the following Tables 1 to 4 (“anionic C-1 to C-6” in the table) ) Was used to prepare a second additive. The content ratio of the acrylamide unit and the sodium acrylate unit in each anionic polymer compound is the molar ratio of each monomer, C-1 is 70:30, C-2 is 70:30, and C-3 is 70: 30, C-4 was 70:30, C-5 was 70:30, and C-6 was 70:30. The viscosity average molecular weight and the anion charge density were measured by the following methods.

[Measurement of viscosity average molecular weight]
The viscosity average molecular weight of the polymer compound was determined by measuring the intrinsic viscosity using a Ubbelohde viscometer (trade name “Viscometer Ubbelohde” manufactured by Shibata Kagaku Co., Ltd.) according to the intrinsic viscosity method, and converting it to polyvinyl alcohol.

[Measurement of cation and anion charge density]
The charge density of each cationic polymer compound was measured using a potassium potassium sulfate (trade name “Polyvinyl potassium sulfate titrant (N / 400)” manufactured by Wako Pure Chemical Industries, Ltd.) according to a colloid titration method. The charge density of the anionic polymer compound was determined by adding methyl glycol chitosan solution (trade name “Methyl glycol chitosan solution (N / 200)” manufactured by Wako Pure Chemical Industries, Ltd.) according to colloidal titration, and then adding the excess to polyvinyl sulfate. It measured using potassium (the Wako Pure Chemical Industries Ltd. make, brand name "Polyvinyl potassium sulfate titrant (N / 400)".

Example 1 and Comparative Example 1 (Manufacture and evaluation of coated base paper)
Pulp components (LBKP: DIP = 80: 20) A pulp-containing aqueous slurry having a concentration of 3.2% by mass was diluted with white water to prepare a pulp-containing aqueous slurry for coated base paper having a slurry concentration of 1.0% by mass. A polyacrylamide type paper strength agent is added to this pulp-containing aqueous slurry in an amount of 0.25% by mass with respect to the pulp component, and a britt type dynamic drainage jar tester (equipped with a stirrer having a 40 mesh screen and a turbine blade. Abbreviated as “Britt Jar”), and stirred with a stirrer at 1200 revolutions per minute, 0.5 mass% of sulfuric acid band at 10 second intervals, alkyl ketene dimer sizing agent (AKD) 0.05% by weight, light calcium carbonate as a filler was added in an amount of 6.1% by weight, and the first additive A or B obtained in Preparation Example 1 or 2 was added to the time shown in Table 1 and Table 2. After 10 seconds, the rotation speed was changed to 600 rotations, and the second additive obtained in Preparation Example 3 was added at the times and addition amounts shown in Tables 1 and 2, and 5 seconds and the mixture was stirred. The case where the additive is added 20 seconds after the filler is added is assumed to be added before the screen, and the case where the additive is added 30 seconds after the filler is added, that is, after the rotational speed is changed to 600, is assumed as the post-screen addition. The results obtained are shown in Tables 1 and 2. In addition, the pH of the pulp-containing aqueous slurry (hereinafter referred to as “sample slurry”) after addition of each papermaking additive, filler and additive was adjusted to 7.6. In Example 1-3, the addition amount of the paper strength agent was reduced by 20%. Furthermore, in Example 1-9, the first additive and the second additive were added 10 seconds and 20 seconds after the filler was added (assumed to be added before the screen), respectively. When the additive was added 10 seconds after the filler was added, it was assumed before the fan pump. In Comparative Example 1-6, as shown in the table, an anionic polymer compound was added as the first additive, and a cationic polymer compound was added as the second additive.

[Yield]
100 ml of the sample slurry obtained in each example was added to Whatman No. It filtered using 4 filter papers, the obtained filtrate was dried for 60 minutes at 110 degreeC, and the total yield (%) was calculated | required by measuring the mass after drying. Further, the ash content yield (%) was measured from the ash content when the dried filter paper was heated at 550 ° C. for 2 hours.

[Turbidity]
While stirring the sample slurry obtained in each example with a stirrer, 50 ml was collected from the pilot hole. Suction filtration was performed with 4 filter papers, and the formazine turbidity of the filtrate was measured according to JIS K0101. This turbidity is for evaluating the yield, paper additive additive, filler, and pitch fixability. The smaller this value, the higher the yield, and the paper additive additive, filler, and pitch fixability. Means high.

[Cation requirement]
As in the turbidity measurement, 50 ml of the sample slurry obtained in each example was collected from the pilot hole while stirring with a stirrer. Suction was filtered through 4 filter papers. The amount of cation required for the obtained filtrate was measured with a particle charge meter (trade name “Particle Charge Detector PCD03” manufactured by Mutech). This cation requirement is for evaluating the charge state in the system. If this value is high, it means that a lot of anionic substances are contained in the system.

[Drainage]
500 ml of the sample slurry obtained in each example was placed in a cylindrical container made of acrylic resin having an inner diameter of 50 mm with 100 mesh stretched, and the time until the amount of drainage reached 200 ml was measured using a graduated cylinder.

[Physical properties and fracture length (tensile strength)]
The coated base paper was made using a paper machine (product name “Square Paper Machine”, manufactured by Tozai Seiki Co., Ltd.) so that the basis weight of the sample slurry obtained in each example was 59 g / m ² . The obtained wet paper was pressurized with a press machine at a load of 5.25 kg / cm ^{2 for} 5 minutes, further pressurized for 2 minutes, and then dehydrated. Subsequently, after drying at 95 ° C. for 3 minutes using a rotary dryer, the paper was left to stand at 25 ° C. and a humidity of 55% for 24 hours to obtain a paper for evaluation. The texture index of this paper was measured using a light transmission type optical total (manufactured by MK SYSTEMS, trade name “3D sheet analyzer”), and texture determination was performed according to the following coating base paper standards.
A: 40 or more O: 35 or more and less than 40 Δ: 30 or more and less than 35 ×: Less than 30 Further, the tearing paper (tensile strength) was measured according to the method of JIS P8113.

Example 2 and Comparative Example 2 (quality paper)
Pulp components (LBKP: NBKP = 90: 10) A pulp-containing aqueous slurry having a concentration of 3.2% by mass with pulp was diluted with white water to prepare a pulp-containing aqueous slurry for high-quality paper having a slurry concentration of 1.0% by mass. After adding 0.3% by mass of a polyacrylamide-based paper strength agent to this pulp-containing aqueous slurry and putting it in a brit jar, the mixture is stirred at 1200 rpm with a stirrer at intervals of 10 seconds. In the first addition obtained in Preparation Example 1 or 2, the sulfuric acid band was added in an amount of 0.5% by mass, the rosin sizing agent was 0.4% by mass, and calcium carbonate was added as a filler in an amount of 2.0% by mass. Agent A or B was added at the time and amount shown in Tables 3 and 4 (added before screen), and after 10 seconds, the number of revolutions was changed to 600, and the second additive obtained in Preparation Example 3 Was added (added after the screen) for the time and the amount shown in Tables 3 and 4, and the mixture was further stirred for 15 seconds. The results obtained are shown in Tables 3 and 4. In addition, the pH of the pulp-containing aqueous slurry (sample slurry) after adding each papermaking additive, filler and additive was adjusted to 7.0. In Example 2-3, the amount of sizing agent added was reduced by 20%. In Comparative Example 2-6, as shown in the table, an anionic polymer compound was added as the first additive, and a cationic polymer compound was added as the second additive.
Using the sample slurries obtained in each example, the yield (total yield and ash yield), turbidity, cation requirement, and drainage were evaluated in the same manner as in Example 1. Furthermore, the physical properties and sizing evaluation of the fine paper obtained by papermaking the sample slurry obtained in each example were performed as follows.

[Material properties]
The sample slurry obtained in each example was paper-made using a paper machine (trade name “Square Paper Machine”, manufactured by Tozai Seiki Co., Ltd.) so that the basis weight was 100 g / m ^2. Similarly, evaluation paper was obtained, the texture index was measured, and texture determination was performed according to the following high-quality paper standards.
◎: 35 or more O: 30 or more and less than 35 △: 25 or more and less than 30 ×: Less than 25

[Size]
The sample slurry obtained in each example is put into a square container, and while stirring, the slurry is put into a paper machine (trade name “square paper machine” manufactured by Tozai Seiki Co., Ltd.), and twice with a constant force with a stirring rod. Stir up and down and finally gently stir. Then, the drain valve of the paper machine was opened, a filter paper and one stainless steel plate were placed on a mat (250 mm × 250 mm) formed on a mesh (40 mesh), and dehydrated with a roller. The mat is peeled off from the mesh, sandwiched between filter paper and a stainless steel plate, and pressed ^two times at a time using a press machine at a load of 5.25 kg / cm ² for 5 minutes. Pressed. Then, it was dried for 3 minutes with a drum dryer (drum surface temperature 95 ° C.), and was conditioned all day and night (20 ° C., 55% humidity) to obtain a paper for evaluation. The sizing degree of this paper conforms to the Steecht method (JIS P8122: 2004),
The degree of size was measured.

  As is clear from Tables 1 to 4, in Examples 1 and 2, the turbidity is improved, so that it is understood that the fixability of the paper additive additive and the pitch component to the pulp component and filler is high. Furthermore, in Examples 1 and 2, it can be seen that high yield and drainage are provided without impairing the physical properties of the paper. On the other hand, paying attention to the cation requirement, since excellent results have been obtained in all physical properties, whether the cation requirement is high or low, irrespective of the charge density in the pulp system, the production method of the present invention and It can be seen that the yield improver kit can be applied.

  Tables 1 and 2 also show that Example 1 showed higher drug fixing properties than Comparative Example 1 and paper with excellent physical properties was obtained even when the aqueous slurry contained recycled pulp. ing. In the coated base paper, the texture and tensile strength (breaking length) are particularly important as the paper quality, but a paper having excellent strength is obtained without impairing the physical properties of the texture. In particular, in Example 1-3, high drainage and yield properties were obtained without reducing the paper strength, even though the paper strength agent was reduced by 20% and added.

  Furthermore, Tables 3 and 4 show that Example 2 exhibited a higher drug fixing property than that of Comparative Example 2 with respect to virgin pulp, and a paper having excellent physical properties was obtained. In the fine paper, the texture and the sizing degree are particularly important as the paper quality, but it can be seen that the fine paper obtained in Example 2 is improved in the sizing degree without impairing the texture. In particular, in Example 2-3, although the sizing agent was reduced by 20% and added, high drainage and yield properties were obtained without a decrease in sizing.

Claims (7)

A method for producing a paper for making paper by adding a cationic polymer compound to a pulp-containing aqueous slurry and then adding an anionic polymer compound,
A method for producing paper, wherein the anionic polymer compound has a viscosity average molecular weight exceeding 35 million and an anionic charge density of 0.6 to 4.0 meq / g.   The method for producing paper according to claim 1, wherein the cationic polymer compound has a viscosity average molecular weight of 10 million or less.   The paper manufacturing method according to claim 1 or 2, wherein the cationic polymer compound has a cationic charge density of 0.4 to 12.0 meq / g. A yield improver kit comprising a first additive containing a cationic polymer compound and a second additive containing an anionic polymer compound,
A yield improver kit, wherein the anionic polymer compound has a viscosity average molecular weight exceeding 35 million and an anionic charge density of 0.6 to 4.0 meq / g.   The yield improver kit according to claim 4, wherein the cationic polymer compound has a viscosity average molecular weight of 10 million or less.   The yield improver kit according to claim 4 or 5, wherein the cationic polymer compound has a cationic charge density of 0.4 to 12.0 meq / g.   The yield improver kit according to any one of claims 4 to 6, wherein the second additive is used after the first additive is added.