JP6799428B2 - Paper manufacturing method and yield improver kit - Google Patents

Description

The present invention relates to a manufacturing method and yield Ri enhancer kit paper, particularly, without impairing the texture properties of the resulting paper, to improve the fixing property of the additive aids for papermaking to the pulp ingredients, additives for the papermaking The present invention relates to a paper manufacturing method and a yield improving agent kit capable of reducing the amount of auxiliary agent added.

In the production of paper, as the speed of the paper machine is increased, the productivity and operability are improved, and the yield agent and drainage are improved in order to improve the whiteness, opacity, printability, strength, etc. of the obtained paper. Additives and fillers for papermaking such as agents, paper strength agents, and sizing agents are used.

For example, in order to improve the yield, drainage, water squeezing, and productivity without impairing the texture of the paper, the first step in the papermaking process is composed of a cationic or amphoteric acrylamide polymer. A method for producing paper (Paper Document 1) has been 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 a second step. With this method, it is possible to create aggregates of pulp components (hereinafter referred to as "flocks") and increase the cohesiveness of these flocs, but the flocs become too fine when they are shared after passing through the screen, which is not possible. There is a problem that the shape becomes uniform, and as a result, the yield is insufficient and the texture may be impaired, or the fixability of the additive aid for papermaking to the pulp component becomes poor.

In recent years, due to environmental problems such as global warming and effective use of resources, the amount of used paper and fillers has been increasing, making it difficult for the additive aids for papermaking to be effective. The amount of addition is increasing, and the pitch processing is insufficient, which causes paper surface defects due to machine stains. Therefore, it is important not only to improve the texture and yield physical properties, but also to fix the additive aid for papermaking to the pulp component.

JP-A-2009-280925

First, the present inventors have added a yield agent containing a cationic or anionic polymer compound having an ultra-high molecular weight and a low charge density to a pulp-containing aqueous slurry to improve the operability in the papermaking process and paper. It has been found that it is possible to produce paper having a high content of used paper and fillers and being uniformly dispersed without impairing the physical properties of the paper. However, the charge state in the system and the anion trash and impurities contained in various pulps and white water (water that is circulated 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, an object of the present invention is to improve the fixability of the additive aid for papermaking to the pulp component and reduce the amount of the additive aid for papermaking without impairing the physical properties of the obtained paper. It is an object of the present invention to provide a method for producing simple paper and a yield improver kit.

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

That is, process for manufacturing paper of the present invention, after the addition of the cationic polymer compound to the pulp-containing aqueous slurry, a process for manufacturing paper to paper by adding anionic polymer compound, wherein the cationic polymer The compound has a viscosity average molecular weight of 10 million or less, the anionic polymer compound has a viscosity average molecular weight of more than 35 million, and has an anion charge density of 0.6 to 4.0 meq / g. It is a feature.

Further , in the method for producing paper of the present invention, it is preferable that the cationic polymer compound has a cationic charge density of 0.4 to 12.0 meq / g.

The yield improving agent kit of the present invention is a yield improving agent kit containing a first additive containing a cationic polymer compound and a second additive containing an anionic polymer compound, and is the above-mentioned cationic polymer compound. There has a viscosity-average molecular weight of 10,000,000, the anionic polymer compound has a viscosity-average molecular weight of greater than 35 million, and possess an anionic charge density of 0.6~4.0meq / g, wherein after addition of the first additive, and is characterized in Rukoto used by addition of the second additive.

Further , in the yield improver kit of the present invention, it is preferable that the cationic polymer compound has a cationic charge density of 0.4 to 12.0 meq / g.

According to the present invention, it is possible to improve the fixability of the additive aid for papermaking to the pulp component and reduce the amount of the additive aid for papermaking without impairing the physical properties of the obtained paper. And a yield improver kit can be provided.

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

First, the method for producing paper of the present invention will be described. The present invention is a method for producing paper in which a cationic polymer compound is added to a pulp-containing aqueous slurry and then an anionic polymer compound is added to make paper, and the anionic polymer compound has a viscosity of more than 35 million. The present invention relates to a method for producing paper having an average molecular weight and an anion charge density of 0.6 to 4.0 meq / g.

Here, the viscosity average molecular weight is a polyvinyl alcohol-equivalent viscosity average molecular weight measured by the ultimate viscosity method. Specifically, it refers to a value obtained by measuring and converting the intrinsic viscosity (intrinsic viscosity) using an Ubbelohde viscometer (manufactured by Shibata Kagaku Co., Ltd., trade name "Viscometer Ubbelohde").

The anion charge density refers to the equivalent number (meq / g) of the anion charge in the monomer unit constituting the polymer compound. Furthermore, the cationic charge density described later refers to the equivalent number (meq / g) of the cationic charges in the monomer unit constituting the polymer compound. Specifically, in the case of an anionic polymer, after adding a methyl glycol chitosan solution (manufactured by Wako Pure Chemical Industries, Ltd., trade name "methyl glycol chitosan solution (N / 200)"), the excess is potassium polyvinyl sulfate (potassium sulfate (N / 200)). Refers to the value obtained by the colloid titration method using the trade name "Polyvinyl Sulfate Titration Solution (N / 400)" manufactured by Wako Pure Chemical Industries, Ltd. In the case of a cationic polymer, polyvinyl sulfate (Wako Pure Chemical Industries, Ltd.) Refers to the numerical value obtained by the colloid titration method using the trade name "Polyvinyl Sulfate Titration Solution (N / 400)" manufactured by Co., Ltd.

Hereinafter, the "cationic polymer compound", the "anionic polymer compound" and the "pulp-containing aqueous slurry" used in the method for producing paper 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 as follows. If the viscosity average molecular weight of the cationic polymer compound exceeds 10 million, the cohesive force to the pulp component is low and the pitch may be over-aggregated. However, if the viscosity average molecular weight is too low, the fixability of the 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 thereafter is further enhanced, and the pitch and pitch are increased. It can improve the fixability with additive aids for paper making, especially sizing agents and paper strength agents.

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

Specific examples of this cationic polymer compound include polyethyleneimine, dimethyldialylamine-sulfur dioxide copolymer, polyacrylamide cation-modified product, polyaminoacrylic acid, and a cationic monomer having a quaternary ammonium salt residue. Examples thereof include homopolymers or copolymers containing, epihalohydrin-alkylamine addition polymers and salts or quaternary ammonium salts of allylamine polymers, and dicyandiamide-formaldehyde-ammonium chloride condensed polymers, and particularly quaternary. A homopolymer or copolymer containing a cationic monomer having an ammonium salt residue as a constituent unit is preferable.

Examples of the cationic monomer having a quaternary ammonium salt residue constituting such a cationic polymer compound include 2- (meth) acryloyloxyethyl trimethylammonium chloride and 2- (meth) acryloyloxyethyl dimethylbenzyl. Ammonium chloride, 2- (meth) acryloyloxyethyl triethylammonium chloride, 2- (meth) acryloyloxyethyl diethylbenzylammonium chloride, 3- (meth) acrylamidepropyltrimethylammonium chloride, 3- (meth) acrylamidepropyltriethylammonium chloride, 3- (Meta) acrylamidepropyldimethylbenzylammonium chloride, diallyldimethylammonium chloride, diallyldiethylammonium chloride, 2- (meth) acryloyloxyethyltrimethylammonium sulfate, 2- (meth) acrylamideethyltrimethylammonium chloride, 2- (meth) Acryloyloxyethyl triethylammonium bromide 3- (meth) acryloyloxypropyldimethylethylammonium chloride 3-methacryloyloxy-2-hydroxypropyltrimethylammonium chloride 3-methacryloyloxy-2-hydroxypropylmethyldiethylammonium chloride 3-methacryloyl Oxy-2-hydroxypropyltrimethylammonium chloride, 2- (meth) acryloylaminoethyltrimethylammonium chloride, 3- (meth) acryloylamino-2-hydroxypropyltrimethylammonium chloride, 2- (meth) acryloylaminoethyltrimethylammonium chloride, etc. Can be mentioned. Among these, homopolymers or copolymers using 2- (meth) acryloyloxyethyltrimethylammonium chloride are preferable because they can easily adjust the cationic charge density and the viscosity average molecular weight 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 this copolymer include ethylenically unsaturated monocarboxylic acids and dicarboxylic acids, (meth) acrylic acid alkyl esters, aromatic vinyl compounds, unsaturated amide compounds and unsaturated nitriles. Examples include compounds. Examples of such are (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, methyl (meth) acrylic acid, ethyl (meth) acrylic acid, butyl (meth) acrylic acid, isobutyl (meth) acrylic acid. , (Pentyl (meth) acrylate, 2-methylbutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, hexyl (meth) acrylate, ( Examples thereof include 2-hydroxyhexyl acrylate, styrene, α-methylstyrene, (meth) acrylamide, N, N-dimethylacrylamide, N-methylolacrylamide, and (meth) acrylonitrile. Among them, (meth) acrylamide, particularly acrylamide, is preferable because it is easily available and polymerization is easily carried out. Further, (meth) acrylic acid, maleic acid, fumaric acid, and itaconic acid are also preferable, and (meth) acrylic acid is particularly preferable, from the viewpoint of efficiently taking in a cationic internal preparation such as cationized starch. The term (meth) acrylic means acrylic or methacrylic.

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 this cationic monomer unit is less than 3 mol%, it is difficult to obtain the desired cationic charge density, and if it is 40 mol% or more, it is difficult to improve the yield of pulp and filler, and the conventional yield agent used is used. It is difficult to reduce the amount. A more preferable blending ratio is in the range of 5 to 30 mol%. Furthermore, when having anionic monomer units such as (meth) acrylic acid, maleic acid, fumaric acid, and itaconic acid, the content of the anionic monomer units in the copolymer is lower than that of the cationic monomer units. 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%, and more preferably in the range of 5 mol% or more and less than 30 mol%. preferable. If this deduction value is less than 3 mol%, it is difficult to obtain the desired cation charge density, and if it is 40 mol% or more, it is difficult to improve the yield of pulp and filler, and it is difficult to reduce the amount of the conventional yield 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 described in the following general formula [I],

(In the formula, R ¹ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, X ¹ is a chlorine atom, a bromine atom, a sulfuric acid residue, a nitrate residue, an organic carboxylic acid residue or an organic sulfonic acid residue, and n is. It is represented by (indicating the degree of polymerization).

The salt of the allylamine polymer represented by the general formula [I] has R ¹ as 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. X ¹ is a chlorine atom, a bromine atom, a sulfuric acid residue, a nitrate residue, an organic carboxylic acid residue, and an organic sulfonic acid residue. Examples of salts of allylamine polymers include polyallylamine hydrochloride, hydrobromide, sulfate, acetate, propionate, and polyN-alkylallylamine salt, polymethylallylamine hydrochloride, poly. Examples thereof include ethylallylamine hydrochloride, polypropylallylamine hydrochloride, polyisopropylallylamine hydrobromide and the like.

The polymerization method of this cationic polymer compound is not particularly limited, and any method such as a solution polymerization method, an emulsion polymerization method, and a solid polymerization method can be used. The polymerization initiator used at this time is a water-soluble azo compound or peroxide, for example, hydrogen peroxide, 2,2'-azobis (2-amidinopropane) dihydrochloride, water-soluble inorganic peroxide, or water-soluble. Examples thereof include a combination of a sex reducing agent and a water-soluble inorganic peroxide or an organic peroxide.

Examples of water-soluble inorganic peroxides include potassium persulfate and ammonium persulfate. Further, as an example of the water-soluble reducing agent, a reducing agent used as a normal radical oxidation-reduction polymerization catalyst component soluble in water, for example, ethylenediamine tetraacetic acid or a sodium salt or potassium salt thereof, or iron, copper, etc. Complex compounds with heavy metals such as chromium, sulfinic acid or its sodium salt or potassium salt, L-ascorbic acid or its sodium salt or potassium salt 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 the water-soluble organic peroxide include cumene hydroperoxide, p-cymen hydroperoxide, tert-butylisopropylbenzene hydroperoxide, diisopropylbenzene hydroperoxide, p-menthan hydroperoxide, decalin hydroperoxide, and tert-amylhydro. Examples thereof include hydroperoxides such as peroxide, tert-butyl hydroperoxide and isopropyl hydroperoxide.

Further, as an emulsifier in this emulsion polymerization, an anionic surfactant or a combination thereof and a nonionic surfactant is usually used. As the anionic surfactant and the nonionic surfactant, any of those used in ordinary emulsion polymerization can be selected and used. Examples of such anionic surfactants include alkylbenzene sulfonates, alkyl sulfonates, alkyl sulfates, metal fatty acid salts, polyoxyalkyl ether sulfates, polyoxyethylene carboxylic acid ester sulfates, Examples thereof include polyoxyethylene alkylphenyl ether sulfate, succinate dialkyl ester sulfonate and the like.

Examples of nonionic surfactants include polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl ether glycerin borate, and polyoxy. Compounds that have a polyoxyethylene chain in the molecule, such as ethylene alkyl ether phosphate, and have a surface-active ability, and compounds in which the polyoxyethylene chain of the compound is replaced by a copolymer of oxyethylene or oxypropylene, Examples thereof 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 in a predetermined ratio in an aqueous medium containing a polymerization initiator and an emulsifier. , Usually, 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 blended into the pulp-containing aqueous slurry as the cationic polymer compound of the present invention, or if desired, the copolymer is taken out as a solid by salting out, spray drying or the like, and this is used. May be blended into a cellulose-containing suspension using. As a method for producing a branched or crosslinked cationic polymer, in each of the above-mentioned polymerization methods, a polyfunctional compound having two or more kinds of reagent groups selected from the group consisting of a double bond, an aldehyde bond or an epoxy bond is used. A cross-linking agent composed of 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). , Formaldehyde, ionic cross-linking agents such as glioxal, and covalent cross-linking agents that copolymerize with monomers) are used for polymerization.

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 of more than 35 million and an anion charge density of 0.6 to 4.0 meq / g. However, any of linear, branched, and crosslinked types can be used.

When the viscosity average molecular weight of the anionic polymer compound of the present invention exceeds 35 million, a high fixing power of the additive aid for papermaking to pulp components and the like can be obtained due to the synergistic effect with the cationic polymer compound. The yield is also good. In particular, when the viscosity average molecular weight is 38 million or more, fine pulp fibers, fillers, and pitch components do not fall off under shearing such as a screen after flock formation, the yield rate is improved, and contamination of the paper machine is prevented. can do. Further, when the viscosity average molecular weight is 80 million or less, the cohesive force is good and the desired physical properties of the paper can be obtained. Therefore, the preferable 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 upper limit of the particularly preferable viscosity average molecular weight is 70 million.

Usually, it has been considered that when a polymer compound having an ultra-high molecular weight exceeding 35 million is added, the polymer compound is not uniformly dispersed in the pulp-containing aqueous slurry, and the physical properties of the texture are deteriorated. 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 has a large size. Flocks with uniform texture 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 such a range, the polymer compound has a molecular chain so that a better cohesive force can be obtained depending on the charge state in the molecule. Since it is spread out, unlike the conventional polymer compounds used as a retention agent, when interacting with pulp fibers, it is possible to exert a yield improvement effect without relying only on electric charge. Therefore, it can be used regardless of the type of paper obtained, such as acid paper or acid-free paper, and even when the charge density in the pulp-containing aqueous slurry is high, the paper can be produced with a high yield without impairing the physical properties of the texture. Can be done. When the charge density is 0.6 meq / g or more and 4.0 meq / g or less, the yield, drainage and physical properties of the texture can be improved, and the pitch amount can be reduced. The preferred charge density is in the range of 0.6 meq / g or more and 3.8 meq / g or less, and particularly preferably 0.8 meq / g or more and 3.0 meq / g or less.

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 constituent unit, for example, sodium polyacrylate or sodium polymethacrylate. And a copolymer of the water-soluble monomer and a constituent unit copolymerizable therewith, for example, a constituent unit such as acrylamide, methacrylicamide, vinyl acetate, acrylonitrile, for example, acrylamide-sodium acrylate copolymer, methacryl. Examples thereof include an amide-sodium acrylate copolymer, and a homopolymer or a copolymer containing sodium acrylate as a constituent 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 form 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, and a solid polymerization method can be used as in the polymerization method of the cationic polymer compound. Can be done.

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 adding them to a pulp-containing aqueous slurry. The pulp-containing aqueous slurry contains pulp components that are conventionally used in the production of paper. The pulp component is not particularly limited, and one selected from one or more kinds of pulp selected from mechanical pulp, chemical pulp, used paper pulp and the like can be used. Examples of mechanical pulp include crushed wood pulp, refiner ground pulp, and thermomechanical pulp (TMP). Examples of the chemical pulp include kraft pulp such as broadleaf kraft pulp (LBKP) and coniferous kraft pulp (NBKP), sulfide pulp, alkaline pulp and the like. Examples of used paper pulp include newspaper, corrugated cardboard, shredder dust and the like as raw materials, and deinked DIP. Although the utilization rate of used paper pulp tends to increase due to an increase in environmental awareness, virgin pulp can also be used in the present invention. Examples of pulp logs include coniferous trees such as spruce, fir, and red pine, and broad-leaved trees such as beech, poplar, and hippopotamus.

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

To the pulp-containing aqueous slurry, a conventional filler or an additive aid for papermaking, which is conventionally used in the production of paper, may be added. The filler is not particularly limited, but is calcium carbonate such as heavy calcium carbonate or light calcium carbonate, titanium oxide, silica, talc, clay, kaolin, magnesium carbonate, barium carbonate, zinc oxide, silicon oxide, aluminum hydroxide. , Inorganic fillers such as calcium hydroxide, magnesium hydroxide, zinc hydroxide, bentonite, white carbon, and organic fillers such as urea-formalin resin, polystyrene resin, melamine resin, phenol resin, and fine hollow particles. The filler may be used alone or in combination of two or more as appropriate. In addition, a recycled filler made from paper sludge, deinking floss, or the like can also be used. The amount of the filler added 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 additive aid for papermaking include a sulfuric acid band, a sizing agent, a paper strength agent, a drainage improver, a coagulant, a pitch control agent, a bulking agent, a slime control agent and the like.

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

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

The place where the cationic polymer compound and the anionic polymer compound of the present invention are added 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, and an inlet. In addition, the piping connected to them can be mentioned. Above all, it is preferable that the space between the seed box and the fan pump or between the fan pump and the screen is improved and can be uniformly fixed by the pulp component.

The place where the anionic polymer compound is added is preferably from the time when the pulp-containing aqueous slurry passes through the seed box until the liquid is sent to the inlet. Of these, the front and back of the screen, for example, between the fan pump and the screen or between the screen and the inlet, are preferable because they easily interact with the previously added cationic polymer compound.

The place and amount of the cationic and anionic polymer compounds added in the method for producing paper of the present invention can also be determined depending on whether the quality of the obtained paper is emphasized or the cost is emphasized. When papermaking is carried out with an emphasis on the quality of the obtained paper, that is, the physical properties of the texture, the concentration of each of the cationic polymer compound and the anionic polymer compound with respect to the pulp component in the pulp-containing aqueous slurry before passing through the screen. Is preferably added so as to be less than 1000 ppm, preferably 10 to 800 ppm. When the polymer compound is added at this position, it is easy to control the physical properties of the obtained paper. Further, when papermaking is carried out with an emphasis on cost, that is, on yield and reduction of the amount of the polymer compound of the present invention added, 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 of the above so that the concentrations of the cationic and anionic polymer compounds are less than 1000 ppm, preferably 10 to 800 ppm with respect to the pulp component. When a cationic or anionic polymer compound is added at this position, a high yield can be easily obtained even with a low addition amount.

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 in terms of mass ratio, but is 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. Is characterized by having a viscosity average molecular weight of more than 35 million and an anion 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 method for producing paper 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 may be any, and are not particularly limited, and examples thereof include water-in-oil emulsions, powders, and solutions. ..

The type of paper produced by the paper manufacturing method and the yield improver kit of the present invention is not particularly limited, and for example, coated paper, finely coated paper, high-quality paper, medium-quality paper, newspaper, PPC paper, and liner. Examples include base paper, core base paper, and white paperboard. According to the paper manufacturing method and the yield improving agent kit of the present invention, the degree of size and the paper strength can be improved, which is suitable for manufacturing 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 texture physical properties of the obtained paper, and the amount of the papermaking additive added. In addition, it is possible to reduce or prevent pitch components derived from used paper, and stains and paper surface defects of the papermaking machine due to anion trash and impurities contained in various pulps and white water. .. 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 in-line with diluted water without providing a dissolution tank. .. Therefore, only one dissolution tank is required for swelling the anionic polymer compound of the present invention, which is more advantageous in terms of management and cost than the conventional two-component retention agent system using two dissolution tanks. is there.

Hereinafter, the paper manufacturing method and the yield improving agent kit of the present invention will be specifically described with reference to Examples, but the manufacturing method and the yield improving agent kit of the present invention are not limited to these Examples.

(Preparation Example 1: Preparation of First Additive A Containing Cationic Polymer Compound)
As the cationic polymer compound, an acrylamide-acrylloyloxyethyl trimethylammonium chloride copolymer having a linear structure having a viscosity average molecular weight and a cationic charge density shown in Tables 1 to 4 below (“cationic A1 to A7” in the table) is used. The first additive A was prepared using. The content ratio of the acrylamide unit and the acryloyloxyethyltrimethylammonium chloride unit in each cationic polymer compound is 90:10 for each monomer, 80:20 for A-2, and 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 the cation charge density were measured by the following methods.

(Preparation Example 2: Preparation of First Additive B Containing Cationic Polymer Compound)
As the cationic polymer compound, an acrylamide-acryloyloxyethyltrimethylammonium chloride-acrylic acid copolymer having a linear structure having a viscosity average molecular weight and a cationic charge density shown in Tables 1 to 4 below (“Cynic B-1” in the table. ”) 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 molar ratio of each monomer. The viscosity average molecular weight and the cation charge density were measured by the following methods.

(Preparation Example 3: Preparation of Second Additive Containing Anionic Polymer Compound)
As an anionic polymer compound, a linear acrylamide-sodium acrylate copolymer having a viscosity average molecular weight and an anion charge density shown in Tables 1 to 4 below (“Anionic C-1 to C-6” in the table”. ) Was used to prepare a second additive. The content ratio of acrylamide unit and 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 ultimate viscosity using an Ubbelohde viscous meter (manufactured by Shibata Kagaku Co., Ltd., trade name "Viscosity Meter Ubbelohde") according to the ultimate viscosity method and converting it into polyvinyl alcohol.

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

Example 1 and Comparative Example 1 (Manufacturing and evaluation of coated base paper)
A pulp-containing aqueous slurry having a pulp component (LBKP: DIP = 80: 20) 3.2% by mass was diluted with white water to prepare a pulp-containing aqueous slurry for coating base paper having a slurry concentration of 1.0% by mass. A polyacrylamide-based paper strength agent was added to this pulp-containing aqueous slurry in an amount of 0.25% by mass based on the pulp components, and a bullet-type dynamic drainage jar tester (equipped with a stirrer equipped with a 40-mesh screen and turbine blades. (Abbreviated as "Brit Jar"), and then stirring at 1200 rpm using a stirrer, 0.5% by mass of the sulfuric acid band at 10-second intervals, alkyl keten dimer-based sizing agent (AKD). In an amount of 0.05% by mass and light calcium carbonate as a filler in an amount of 6.1% by mass, the first additive A or B obtained in Preparation Example 1 or 2 was added in the time shown in Tables 1 and 2. After 10 seconds, the number of rotations was changed to 600, and the second additive obtained in Preparation Example 3 was added at the time and amount shown in Tables 1 and 2, and further. The mixture was stirred for 15 seconds. It is assumed that the case where the additive is added 20 seconds after the addition of the filler is added before the screen, and the case where the additive is added 30 seconds after the addition of the filler, that is, after the rotation speed is changed to 600 rpm, is assumed to be added after the screen. The results obtained are shown in Tables 1 and 2. The pH of the pulp-containing aqueous slurry (hereinafter referred to as "sample slurry") after the addition of each papermaking additive, filler and additive was adjusted to be 7.6. In Examples 1-3, the amount of the paper strength agent added was reduced by 20%. Further, in Example 1-9, the first additive and the second additive were added 10 seconds and 20 seconds after the addition of the filler, respectively (assumed to be added before the screen). When the additive was added 10 seconds after the filler was added, it was assumed that it was before the fan pump. Further, 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 subjected to Whatman No. The total yield (%) was determined by filtering using 4 filter papers, drying the obtained filtrate at 110 ° C. for 60 minutes, and measuring the mass after drying. In addition, 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, and Whatman No. 4 The filtrate was suction-filtered with a filter paper, and the turbidity of formazine was measured by JIS K0101. This turbidity is for evaluating the yield, the additive aid for papermaking, the filler, and the fixability of the pitch. The smaller this value is, the higher the yield is, and the fixing rate of the additive aid for papermaking, the filler, and the pitch is high. It means that it is expensive.

[Cation requirement]
As with the turbidity measurement, 50 ml of the sample slurry obtained in each example was collected from the pilot hole while being stirred with a stirrer, and Whatman No. 4 Suction filtration was performed with filter paper. The cation requirement of the obtained filtrate was measured with a particle charge meter (manufactured by Mutec, trade name "Particle Charge Detector PCD03"). This cation requirement is for evaluating the charge state in the system, and if this value is high, it means that the system contains a large amount of anionic substances.

[Water 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 and covered with 100 mesh, and the time until the amount of filtered water reached 200 ml was measured using a measuring cylinder.

[Physical properties and tear length (tensile strength)]
The sample slurry obtained in each example was used to make a coating base paper using a paper machine (manufactured by Tozai Seiki Co., Ltd., trade name "square paper machine") so that the basis weight 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 pressed for 2 minutes, and then dehydrated. Subsequently, after drying at 95 ° C. for 3 minutes using a rotary dryer, the mixture was left 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 ground total (manufactured by MK SYSTEMS, trade name "3D sheet analyzer"), and the texture was judged according to the following coating base paper standard.
⊚: 40 or more 〇: 35 or more and less than 40 Δ: 30 or more and less than 35 ×: less than 30 The tear length (tensile strength) of the obtained evaluation paper was measured according to the method of JIS P8113.

Example 2 and Comparative Example 2 (Woodfree Paper)
A pulp-containing aqueous slurry having a pulp component (LBKP: NBKP = 90:10) 3.2% by mass was diluted with white water to prepare a pulp-containing aqueous slurry for woodfree paper having a slurry concentration of 1.0% by mass. To this pulp-containing aqueous slurry, 0.3% by mass of a polyacrylamide-based paper strength agent was added to the pulp components, placed in a blit jar, and then stirred at 1200 rpm using a stirrer at 10-second intervals. The first addition obtained in Preparation Example 1 or 2 was carried out by adding 0.5% by mass of a sulfuric acid band, 0.4% by mass of a rosin-based sizing agent, and 2.0% by mass of calcium carbonate as a filler. Agent A or B was added at the time and amount shown in Tables 3 and 4 (addition before the screen), and after 10 seconds had passed, the rotation speed was changed to 600 rotations, and the second additive obtained in Preparation Example 3 was added. Was added (added after the screen) at the time and 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. The pH of the pulp-containing aqueous slurry (sample slurry) after the addition of each papermaking additive, filler and additive was adjusted to 7.0. In Examples 2-3, the amount of the sizing agent added was reduced by 20%. Further, 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 as follows in the same manner as in Example 1. Further, the texture physical properties and the degree of size of the high-quality paper obtained by papermaking the sample slurry obtained in each example were evaluated as follows.

[Physical properties]
The sample slurry obtained in each example was made into high-quality paper using a paper machine (manufactured by Tozai Seiki Co., Ltd., trade name "square paper machine") so that the basis weight was 100 g / m ^2, and the same as in Example 1. In the same manner, a paper for evaluation was obtained, the texture index was measured, and the texture was judged according to the following woodfree paper criteria.
⊚: 35 or more 〇: 30 or more and less than 35 Δ: 25 or more and less than 30 ×: less than 25

[Size degree]
Put the sample slurry obtained in each example into a square container, put the slurry in a paper machine (manufactured by Tozai Seiki Co., Ltd., trade name "square paper machine") while stirring, and use a stirring rod twice with a constant force. Stir up and down, and finally gently. Then, the drain valve of the paper machine was opened, a filter paper and a stainless steel plate were placed on a mat (250 mm × 250 mm) formed on a mesh (40 mesh), and dehydrated by a roller. Peel the mat from the mesh, sandwich it between filter paper and stainless steel plate, press it once with a load of 5.25 kg / cm for ² to 5 minutes using a press machine, and then press it once with the load for 2 minutes. Pressed. Then, it was dried with a drum type dryer (drum surface temperature 95 ° C.) for 3 minutes, and the humidity was adjusted day and night (20 ° C., humidity 55%) to obtain a paper for evaluation. The size of this paper is based on the Stekicht method (JIS P8122: 2004).
The degree of size was measured.

As is clear from Tables 1 to 4, in Examples 1 and 2, since the turbidity is improved, it can be seen that the additive aid for papermaking and the pitch component have high fixability to the pulp component and the filler. Further, it can be seen that in Examples 1 and 2, high yield and drainage are provided without impairing the physical properties of the paper. On the other hand, focusing on the cation requirement, excellent results are obtained in all physical properties regardless of whether the cation requirement is high or low. Therefore, regardless of the charge density in the pulp system, the production method of the present invention and it can be seen that it is possible to apply the yield Ri enhancer kit.

Further, in Tables 1 and 2, it was shown that even if the aqueous slurry contained recycled pulp, Example 1 showed higher drug fixability than Comparative Example 1, and paper having excellent physical properties was obtained. ing. In the coated base paper, the texture and the tensile strength (tear 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 Examples 1-3, although the paper strength agent was added in a reduced amount of 20%, high drainage and yield physical properties were obtained without reducing the paper strength.

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

Claims (4)

A method for producing paper in which a cationic polymer compound is added to a pulp-containing aqueous slurry and then an anionic polymer compound is added to make paper.
The cationic polymer compound has a viscosity average molecular weight of 10 million or less.
A method for producing paper, wherein the anionic polymer compound has a viscosity average molecular weight of more than 35 million and an anion charge density of 0.6 to 4.0 meq / g. Process for manufacturing paper of claim 1 wherein the cationic polymer compound having a cationic charge density of 0.4~12.0meq / g. A yield improver kit containing a first additive containing a cationic polymer compound and a second additive containing an anionic polymer compound.
The cationic polymer compound has a viscosity average molecular weight of 10 million or less.
The anionic polymeric compound has a viscosity-average molecular weight of greater than 35 million, and possess an anionic charge density of 0.6~4.0meq / g,
A yield improver kit characterized in that the first additive is added and then the second additive is added and used . The yield improver kit according to claim 3, wherein the cationic polymer compound has a cationic charge density of 0.4 to 12.0 meq / g.