JP6764136B2 - Paper manufacturing method - Google Patents

Description

The present invention relates to a method for producing paper.

When manufacturing textile products such as paper, paperboard, and wood fiber, a sizing agent is used to impart water resistance, ink resistance, bleeding resistance, and the like to these. Examples of such a sizing agent include rosin having a carboxyl group or a rosin-based sizing agent typified by enhanced rosin (maleinized rosin), a ketene dimer-based sizing agent, a substituted cyclic dicarboxylic acid anhydride-based sizing agent, and the like. .. The rosin-based sizing agent itself is difficult to fix on the cellulosic fiber, and is made by using aluminum sulfate in the acidic to neutral region of pH 4.5 to 7.0. In addition, ketene dimer-based sizing agents and substituted cyclic dicarboxylic acid anhydride-based sizing agents are mainly used for papermaking in the neutral region of pH 6.5 to 8.0, because of their ease of use and excellent sizing effect. Ketene dimer-based sizing agents are widely used.

By the way, in the paper industry in recent years, it has been closed due to the reuse of used paper and white water, the reduction of papermaking wastewater, etc., and it is difficult for the size effect to be exhibited due to the influence of metal components and impurities in the papermaking system. .. On the other hand, for example, in a system in which a rosin-based sizing agent is used, a large amount of aluminum sulfate is added, but since an odor derived from hydrogen sulfide is likely to be generated in the papermaking system, aluminum sulfate is used to reduce the environmental load. There is also a movement to reduce the amount of addition. However, in that case, the sizing effect of the rosin-based sizing agent is less likely to appear. Further, in the case of a ketene dimer-based sizing agent, it takes time for the sizing effect to appear, so-called "rising of the sizing effect", and in the case of papermaking in an acidic region, the size effect is caused by hydrolysis of the ketene dimer-based sizing agent. However, there are problems such as not being applicable to a wide range of papermaking systems.

In such an environment, as a technique for improving the size effect of the ketene dimer-based sizing agent, for example, a copolymer obtained by polymerizing a polymerization component containing diallylamine and (meth) acrylamide, and a ketene dimer-based size. A method for producing paper for making paper using an agent is known (Patent Document 1), but diallylamine is expensive and has a problem in terms of balance with the size effect.

Japanese Unexamined Patent Publication No. 2012-214924

It is an object of the present invention to provide a method for producing a paper which exhibits an excellent size effect and can reduce an odor without using a water-soluble aluminum compound in a papermaking system.

In order to solve the above problems, the present inventors have diligently studied chemicals that mainly add a sizing agent to a papermaking system, and have completed the present invention. That is, the present invention relates to the following paper manufacturing method.

A 1.3-valent or tetravalent carboxylic acid (a1), a monovalent aliphatic alcohol (a2-1) having an alkyl group or an alkenyl group having 6 to 22 carbon atoms, and an alkyl having 6 to 22 carbon atoms. Contains a dehydration condensate with at least one compound (a2) selected from the group consisting of aliphatic amines (a2-2) having a group and / or an alkenyl group and / or a salt (A) and an emulsifier (B) thereof. A method for producing paper, comprising a step of adding an emulsion sizing agent for papermaking to a pulp slurry, and not adding a water-soluble aluminum compound (C).

2. 2. The method for producing paper according to item 1 above, wherein the component (B) contains a polymer of a monomer component containing styrenes (b1) and / or (meth) acrylamide (b2).

3. 3. The method for producing paper according to item 1 or 2 above, which further comprises a step of adding a paper strength enhancer (D).

4. The paper of item 3 above, wherein the component (D) is a (meth) acrylamide-based polymer of a monomer component containing (meth) acrylamide (d1), a cationic unsaturated monomer (d2) and an anionic unsaturated monomer (d3). Manufacturing method.

5. The method for producing paper according to the above item 3 or 4, wherein the ratio of the number of amino groups and the number of carboxyl groups in the (meth) acrylamide polymer is (number of amino groups) / (number of carboxyl groups) = 1 to 15.

According to the method for producing paper of the present invention, it is possible to show an excellent size effect and reduce the odor during the papermaking process without adding a water-soluble aluminum compound.

The method for producing paper of the present invention is a monovalent aliphatic having a trivalent or tetravalent carboxylic acid (a1) (hereinafter referred to as a component (a1)) and an alkyl group or an alkenyl group having 6 to 22 carbon atoms. Alcohol (a2-1) (hereinafter referred to as (a2-1) component) and an aliphatic amine (a2-2) having an alkyl group and / or an alkenyl group having 6 to 22 carbon atoms (hereinafter, (a2-2) A dehydration condensate with at least one compound (a2) (hereinafter referred to as (a2) component) selected from the group consisting of (referred to as component) and / or a salt thereof (A) (hereinafter referred to as (A) component), The step includes adding an emulsion sizing agent for papermaking (hereinafter, also simply referred to as “sizing agent”) containing an emulsifier (B) (hereinafter, referred to as a component (B)) and water to a pulp slurry.

The component (a1) is not particularly limited as long as it is a trivalent or tetravalent carboxylic acid, and various known components can be used. For example, citric acid, tricarbaryl acid, t-aconitic acid, trimellitic acid, pyromellitic acid, butanetetracarboxylic acid and the like can be mentioned. The carboxyl group of these trivalent or tetravalent carboxylic acids may be an acid anhydride. Further, the component (a1) may be an ester or amide of a trivalent carboxylic acid or a tetravalent carboxylic acid that can react with the component (a2) by transesterification or amide exchange reaction. These may be used alone or in combination of two or more. Of these, citric acid is preferable because it enhances the size effect and is relatively inexpensive.

The component (a2-1) is not particularly limited as long as it is a monohydric aliphatic alcohol having an alkyl group and / or an alkenyl group having 6 to 22 carbon atoms, and various known ones can be used. The component (a2-1) may be a saturated fatty alcohol or an unsaturated fatty alcohol containing a carbon-carbon unsaturated bond in the molecule.

The saturated fatty alcohol is not particularly limited, and examples thereof include 2-ethylhexyl alcohol, octyl alcohol, lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, and behenyl alcohol. The unsaturated aliphatic alcohol is not particularly limited, and examples thereof include oleyl alcohol. These may be used alone or in combination of two or more. As the component (a2-1), palmityl alcohol, stearyl alcohol and a mixture thereof are preferable from the viewpoint of enhancing the size effect of the sizing agent.

The component (a2-2) is not particularly limited as long as it is an aliphatic amine having an alkyl group and / or an alkenyl group having 6 to 22 carbon atoms, and various known components can be used. As the amine, a primary amine or a secondary amine is preferable. Examples of the primary amine include octylamine, decylamine and stearylamine, and examples of the secondary amine include dioctylamine, didecylamine, distearylamine, di-cured beef tallow amine and dibehenylamine. These may be used alone or in combination of two or more.

As the component (a2), the component (a2-1) or the component (a2-2) may be used alone or in combination. Further, from the viewpoint of increasing the hydrophobicity of the sizing agent and further enhancing the sizing effect, the component (a2-2) is preferable among the components (a2), and distearylamine and di-cured beef tallow amine are more preferable.

The reaction of the component (a1) and the component (a2) can be dehydrated and condensed under the reaction conditions of a reaction of reacting a normal carboxylic acid with an alcohol to esterify, and a reaction of reacting a carboxylic acid with an amine to amidate. .. For example, in consideration of the boiling point of each component, dehydration condensation may be carried out under normal pressure or reduced pressure while stirring at about 110 to 180 ° C. for about 1 to 24 hours. Further, if necessary, a known basic or acidic catalyst or solvent may be used. The reaction may proceed by azeotropic dehydration by using a solvent such as benzene, toluene, or xylene.

The same can be performed even when a lower ester of carboxylic acid or an amide of carboxylic acid is used as a starting material as the component (a1). It is preferable to use a catalyst for transesterification, and examples thereof include di-n-butyltin oxide and p-toluenesulfonic acid.

The amount of the component (a1) and the component (a2) used is usually such that at least one carboxyl group of the component (a1) forms an ester bond and / or an amide bond with the component (a2) and the component (a1) is used. It is preferable to adjust so that at least one carboxyl group remains unreacted. When a trivalent carboxylic acid is used as the component (a1), the hydroxyl group or amino group of the component (a2) has 1 to 2 equivalents with respect to 3 equivalents of the carboxyl group of the component (a1). To do. When a tetravalent carboxylic acid is used as the component (a1), the hydroxyl group or the amino group of the component (a2) has 2 to 3 equivalents with respect to 4 equivalents of the carboxyl group of the component (a1). To do so. The remaining carboxyl group may exist as a carboxyl group or may form a carboxyl group salt. Examples of the carboxyl group salt include alkali metal salts such as sodium and potassium, and ammonium salts such as ammonia, methylamine, and ethanolamine.

The physical properties of the component (A) thus obtained are not particularly limited, and for example, the melting point is usually 100 ° C. or lower, preferably 70 ° C. or lower.

The acid value is not particularly limited, and is usually about 10 to 200 mgKOH / g, preferably about 20 to 150 mgKOH / g. The acid value was measured in accordance with JIS K 0070.

The component (B) is not particularly limited, and various known emulsifiers can be used, and specific examples thereof include nonionic emulsifiers, cationic emulsifiers, anionic emulsifiers, and amphoteric emulsifiers.

The nonionic emulsifier is nonionic and does not have a structure derived from an anionic unsaturated monomer such as a cationic unsaturated monomer and a carboxyl group-containing unsaturated monomer, which will be described later, in the polymer.
The cationic emulsifier has a structure derived from a cationic unsaturated monomer in the polymer. Even if it has a structure derived from an anionic unsaturated monomer, it is included in the cationic emulsifier as long as it is cationic as a whole.
The anionic emulsifier has a structure derived from an anionic unsaturated monomer in the polymer. Even if it has a structure derived from a cationic unsaturated monomer, it is included in the anionic emulsifier as long as it is anionic as a whole.
The amphoteric emulsifier has a structure derived from a cationic unsaturated monomer and an anionic unsaturated monomer in the polymer.

In the present invention, it is preferable to contain a polymer of a monomer component containing styrenes (b1) (hereinafter referred to as (b1) component) and / or (meth) acrylamide (b2) (hereinafter referred to as (b2) component). .. Hereinafter, the polymer will be described.

The component (b1) is not particularly limited, and examples thereof include styrenes such as styrene and α-methylstyrene; and styrene-based monomers having an alkyl group having 1 to 4 carbon atoms in the aromatic ring of the styrenes.

The amount of the component (b1) used is not particularly limited, but is usually about 5 to 80 mol% in terms of molar ratio, where the total of the monomer components forming the component (B) is 100 mol%.

Examples of the component (b2) include acrylamide and methacrylamide.

The amount of the component (b2) used is not particularly limited, but the total of the monomer components constituting the component (B) is 100 mol%, and the molar ratio is preferably about 50 to 90 mol%, preferably about 60 to 85 mol%. Is more preferable.

The other monomer components are not particularly limited, and various known ones can be used. For example, a carboxyl group-containing unsaturated monomer (b3) (hereinafter referred to as (b3) component) and a sulfo group-containing unsaturated monomer (b4) can be used. (Hereinafter referred to as component (b4)), hydrophobic unsaturated monomer (b5) other than component (b1) (hereinafter referred to as component (b5)), polyfunctional unsaturated monomer (b6) (hereinafter referred to as component (b6)) .) Etc. may be used.

The component (b3) is not particularly limited as long as it has a carboxyl group, and examples thereof include (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, and salts thereof. Be done. The salt is not particularly limited, and examples thereof include alkali metal salts such as sodium salt and potassium salt, and ammonium salts such as ammonia, methylamine, and ethanolamine. These may be used alone or in combination of two or more. Of these, itaconic acid or a salt thereof is preferable.

The amount of the component (b3) used is not particularly limited, but from the viewpoint of maintaining excellent emulsifying property, the total of the monomer components forming the component (B) is 100 mol%, and the molar ratio is 2 to 40 mol%. The degree is preferable, and about 3 to 20 mol% is more preferable.

The component (b4) is not particularly limited as long as it has a sulfo group, and is, for example, styrene sulfonic acid, vinyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylic acid. Sulfonic acid-based unsaturated monomers such as sulfoethyl, sulfopropyl (meth) acrylate, (meth) allyl sulfonic acid; sulfate ester of hydroxyethyl (meth) acrylate, sulfate ester of hydroxypropyl (meth) acrylate, (meth) Sulfonic acid ester-based unsaturated monomers such as the sulfate ester of polyoxyalkylene acrylate and the sulfate ester of polyoxyethylene alkyl propenyl ether; the salts thereof and the like can be mentioned. The salt is not particularly limited, and examples thereof include alkali metal salts such as sodium and potassium, amine salts such as ammonium salt, trimethylamine, triethylamine, dimethylamine, diethylamine, monomethylamine, and monoethylamine. These may be used alone or in combination of two or more. Of these, (meth) allylsulfonic acid or a salt thereof is preferable because the weight average molecular weight of the component (B) can be easily adjusted.

The amount of the component (b4) used is not particularly limited, but the component (B) can be used from the viewpoint that the obtained sizing agent is fixed to the raw material pulp and the sizing agent is dissolved and spread on the paper when dried. The total of the monomer components to be formed is 100 mol%, and the molar ratio is preferably about 0.1 to 10 mol%, more preferably about 0.5 to 5 mol%.

The component (b5) is not particularly limited, and for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, Alkyl (meth) acrylates such as cyclohexyl (meth) acrylates having 1 to 20 carbon atoms; carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate; α-olefins having alkyl groups having 6 to 22 carbon atoms; Alkyl vinyl ethers having 1 to 22 carbon atoms in the alkyl group; vinylpyrrolidone and the like can be mentioned. These may be used alone or in combination of two or more. Among them, an alkyl (meth) acrylate having an alkyl group having 1 to 20 carbon atoms is preferable, and an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms is more preferable from the viewpoint of excellent emulsifying property.

The amount of the component (b5) used is not particularly limited, but from the viewpoint of excellent emulsifying property, the total of the monomer components forming the component (B) is 100 mol%, and the molar ratio is about 2 to 30 mol%. It is preferably about 5 to 20 mol%, more preferably about 5 to 20 mol%.

The component (b6) is not particularly limited as long as it is a polyfunctional monomer having two or more radically polymerizable functional groups, and for example, polyfunctional (meth) acrylamide such as methylenebisacrylamide; hexanediol di (meth) acrylate, and the like. 1,9-Nonandiol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, hexaethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, dicyclopentanyldi (meth) acrylate, tri Polyfunctional (meth) acrylates such as methylolpropantri (meth) acrylates, pentaerythritol tri (meth) acrylates, 1,3,5-tri (meth) acryloylhexahydro-1,3,5-triazine; divinylbenzene and the like. Examples include aromatic polyvinyl compounds. These may be used alone or in combination of two or more.

The amount of the component (b6) used is not particularly limited, but is preferably about 0.1 to 5 mol% in terms of molar ratio, with the total of the monomer components forming the component (B) being 100 mol%.

As the monomer forming the component (B) of the present invention, a cationic unsaturated monomer (b7) (hereinafter referred to as the component (b7)) may be further used. The component (b7) refers to a monomer having an unsaturated double bond and a cationic group such as an unsaturated monomer having a tertiary amino group or a quaternary amino group. The amount of the component (b7) used is preferably about 0.1 to 25 mol%, more preferably about 1 to 24 mol%, with the total of the monomer components forming the component (B) as 100 mol%.

Examples of the unsaturated monomer having a tertiary amino group include dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminopropyl (meth) acrylate and the like. Dialkylaminoalkyl (meth) acrylate; Dialkylaminoalkyl (meth) acrylamide such as dimethylaminoethyl (meth) acrylamide, diethylaminoethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, diethylaminopropyl (meth) acrylamide, etc. Be done.

Examples of the unsaturated monomer having a quaternary amino group include those obtained by reacting the unsaturated monomer having a tertiary amino group with a quaternizing agent to quaternize it. It can also be obtained by reacting a quaternizing agent with a polymer obtained by using the unsaturated monomer having a tertiary amino group. Examples of the quaternary agent include conventionally known agents such as oxides, organic halides, dimethyl sulfate, and diethyl sulfate. The oxides are not particularly limited, and examples thereof include alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide; and styrene oxide. The organic halide is not particularly limited, and examples thereof include methyl chloride, ethyl chloride, benzyl chloride, epichlorohydrin, glycidyltrimethylammonium chloride, 3-chloro-2-hydroxyammonium chloride and the like.

Further, as the monomer constituting the component (B) of the present invention, if necessary, a nitrile-based monomer such as (meth) acrylonitrile; hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, Hydroxyl group-containing (meth) acrylates such as glycerin mono (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol mono (meth) acrylate, and (meth) allyl alcohol; polyoxyalkylene (meth) acrylate, polyoxyalkylene glycerin ( Polyoxyalkylene group-containing unsaturated monomers such as meta) acrylate, polyoxyalkylene monoalkyl (meth) acrylate, polyoxyalkylene (meth) allyl ether, and polyoxyalkylene glycerin (meth) allyl ether may be used. The amount of these used is also not particularly limited, and the molar ratio is less than 20 mol%, where the total of the monomer components forming the component (B) is 100 mol%.

As a method for producing the polymer, various known methods such as solution polymerization, emulsion polymerization, and suspension polymerization can be adopted, and the polymer can be easily obtained by polymerizing the monomer components. In the case of solution polymerization, a solvent such as isopropyl alcohol, ethyl alcohol, or methyl isobutyl ketone can be used. The emulsifier used in the emulsion polymerization is not particularly limited, and various surfactants can be used. The surfactant is not particularly limited, and for example, dialkyl sulfosuccinate, alcan sulfonate, α-olefin sulfonate, polyoxyethylene alkyl ether sulfosuccinate salt, polyoxyethylene styrylphenyl ether sulfosuccinate salt. , Naphthalin sulfonic acid formalin condensate, polyoxyethylene alkyl ether sulfate ester salt, polyoxyethylene alkyl phenyl ether sulfate ester salt and other anionic surfactants; polyoxyethylene alkyl ether, polyoxyethylene styrylphenyl ether, polyoxyethylene Nonionic surfactants such as sorbitan fatty acid esters; reactive surfactants in which a vinyl group, an allyl group, or a propenyl group is introduced into these surfactants can be mentioned. Two or more of these surfactants can be used alone or in combination as appropriate. The amount of the surfactant used is usually about 0.1 to 10% by weight with respect to 100% by weight of all the monomer components.

The polymerization initiator used in the polymerization is not particularly limited, and is, for example, persulfate such as ammonium persulfate, potassium persulfate, sodium persulfate; 2,2'-azobis (2-amidinopropane) hydrochloride. The azo-based polymerization initiator and the like can be mentioned. These may be used alone or in combination of two or more. Of these, ammonium persulfate, potassium persulfate, and 2,2'-azobis (2-amidinopropane) hydrochloride are preferable. Further, although optional, a reducing agent may be used in combination in terms of facilitating the generation of radicals of the organic peroxide. Examples of the reducing agent include sulfites such as sodium sulfite; hydrogen sulfites such as sodium hydrogen sulfite; triethanolamine, cuprous sulfate and the like. Further, a known chain transfer agent may be used in combination to adjust the weight average molecular weight of the component (B). The chain transfer agent is not particularly limited, and examples thereof include isopropyl alcohol, carbon tetrachloride, ethylbenzene, isopropylbenzene, cumene, thioglycolic acid ester, alkyl mercaptan, 2,4-diphenyl-4-methyl-1-pentene and the like. Can be mentioned.

Additives such as antioxidants, preservatives, antifoaming agents, and chelating agents may be added to the component (B), if necessary.

The physical properties of the component (B) obtained by the above-mentioned production method are not particularly limited, but for example, the viscosity at a concentration of 25% by weight and a temperature of 25 ° C. is preferably about 50 to 1000 mPa · s.

The content of the component (B) in the emulsion sizing agent for papermaking of the present invention is not particularly limited, but is usually about 5 to 50 parts by weight, preferably 10 to 30 parts by weight, based on the solid content weight of the component (A). Is. If it is less than 5 parts by weight, it is difficult to maintain sufficient emulsifying property, and if it exceeds 50 parts by weight, the content of the component (A) in the sizing agent is reduced, and it is difficult to obtain a sufficient sizing effect.

By using the component (B), the dispersibility of the component (A) in water is stabilized, and a high size effect can be ensured in a wide pH range.

As a method of dispersing the component (A) with the component (B), that is, a method of producing an emulsion sizing agent, either a high-pressure emulsification method or a reversal emulsification method can be adopted. As the dispersion medium, alcohol such as ethanol and isopropanol; water is preferably used from the viewpoint of environmental load, but a mixed solvent of water and an organic solvent may be used.

The organic solvent is not particularly limited as long as it is soluble in water, and for example, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, t-butyl alcohol, and isobutyl alcohol. , N-Hexyl alcohol, n-octyl alcohol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, diacetone alcohol and other alcohols; ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether and other ethers, etc. Can be mentioned. These may be used alone or in combination of two or more. When an organic solvent is contained, the content of the organic solvent is preferably less than 10% by weight.

In the case of the high-pressure emulsification method, the component (A) forming the dispersed phase is melted or dissolved in a solvent such as benzene or toluene, and then the component (B) is added at the above-mentioned usage ratio and hot water is mixed at the same time. After emulsification using a high-pressure emulsifier, an aqueous dispersion can be obtained as it is or by distilling off a solvent. In the case of the inversion method, the solid content (A) and (B) are sufficiently kneaded, and then warm water is gradually added dropwise while stirring under melting, and the phase is inverted to form a solvent and special emulsification. An aqueous dispersion can be obtained without using an apparatus. The solid content concentration of the aqueous dispersion is not particularly limited, but is usually 10 to 50% by weight, and can be diluted with water and used if necessary.

Additives such as antioxidants, preservatives, defoamers, and chelating agents may be added to the papermaking emulsion sizing agent, if necessary.

The physical properties of the emulsion sizing agent for papermaking obtained by the above-mentioned production method are not particularly limited, and for example, the viscosity of a B-type viscometer at a concentration of 30% by weight and a temperature of 25 ° C. is preferably about 10 to 200 mPa · s. Is about 10 to 100 mPa · s. The volume average particle size is usually about 0.3 to 2 μm, preferably about 0.4 to 1.5 μm.

The method for producing paper of the present invention is characterized in that the water-soluble aluminum compound (C) (hereinafter referred to as the component (C)) is not added from the viewpoint of reducing odor. Examples of the component (C) include aluminum sulfate, aluminum chloride, basic aluminum sulfate, basic aluminum chloride, aluminum sulfate, polyaluminum chloride, and polyaluminum hydroxide.

Although the method for producing paper of the present invention is arbitrary, it may include a step of adding a paper strength enhancer (D) (hereinafter referred to as component (D)) from the viewpoint of fixing the sizing agent in the paper at a high level. preferable.

The component (D) is not particularly limited, and for example, starches such as corn starch, tapioca starch, oxidized starch, cationized starch, enzyme-modified starch, inorganic peroxide-modified starch, and amphoteric starch; (meth) acrylamide-based. Examples include polymers.

The ionicity of the component (D) may be cationic, anionic or amphoteric, but amphoterism is preferable from the viewpoint of fixing the sizing agent in the paper at a high level. Further, from the same point of view, an amphoteric (meth) acrylamide polymer (hereinafter, simply referred to as “polymer”) is more preferable.

Examples of the monomer component forming the polymer include (meth) acrylamide (d1) (hereinafter referred to as (d1) component), cationic unsaturated monomer (d2) (hereinafter referred to as (d2) component), and anionic unsaturated monomer. Examples thereof include those containing a saturated monomer (d3) (hereinafter, referred to as a component (d3)).

Examples of the component (d1) include acrylamide and methacrylamide.

The content of the component (d1) is usually about 55 to 97 mol%, preferably about 60 to 95 mol%, more preferably 70 to 90 mol, with the total of all monomer components being 100 mol% in terms of molar ratio. It is about%.

The component (d2) is not particularly limited, and various known components can be used. For example, a secondary amino group-containing unsaturated monomer, a tertiary amino group-containing unsaturated monomer, and 4 of these unsaturated monomers. Examples include graded salts.

Examples of the secondary amino group-containing unsaturated monomer include diallylamine and the like. Examples of the tertiary amino group-containing unsaturated monomer include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylamide, N, Examples thereof include N-diethylaminopropyl (meth) acrylamide. The quaternized salt of these monomers means a quaternized salt obtained by reacting the secondary amino group-containing unsaturated monomer or the tertiary amino group-containing unsaturated monomer with a quaternizing agent, and the like. The salt may be an inorganic acid salt such as a hydrochloride or a sulfate, or an organic acid salt such as an acetate. Examples of the quaternizing agent include methyl chloride, benzyl chloride, dimethyl sulfate, epichlorohydrin and the like. These may be used alone or in combination of two or more. Among these, it is preferable to contain a tertiary amino group-containing unsaturated monomer and / or a quaternized salt of the monomer, and N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth). A benzyl chloride quaternized salt of acrylate is more preferred.

The content of the component (d2) is usually 100 mol% as the total of all the monomer components in a molar ratio from the viewpoint that the component (D) is well fixed in the paper and the sizing agent is highly fixed in the paper. Is about 1 to 20 mol%, preferably about 1 to 17 mol%, and more preferably about 1 to 12 mol%.

The component (d3) is not particularly limited, and various known substances can be used. For example, α, β-unsaturated monocarboxylic acids such as (meth) acrylic acid and crotonic acid; maleic acid and fumaric acid. , Α, β-unsaturated dicarboxylic acids such as itaconic acid, muconic acid and citraconic acid; organic sulfonic acids such as vinyl sulfonic acid and styrene sulfonic acid; sodium salts and potassium salts of these acids can be mentioned. Among these, α, β-unsaturated dicarboxylic acid is preferable, and itaconic acid is more preferable. In addition, these may be used alone or in combination of two or more.

The content of the component (d3) is not particularly limited, and is usually about 1 to 20 mol%, preferably about 1 to 17 mol%, more preferably about 1 to 17 mol%, with the total of all the monomer components being 100 mol% in terms of molar ratio. It is about 1 to 12 mol%.

Further, the monomer group may further contain a crosslinkable unsaturated monomer (d4) (hereinafter, referred to as a component (d4)).

The component (d4) is not particularly limited, and various known components can be used. Specific examples of the component (d4) include crosslinkable unsaturated monomers having an allyl group such as allyl (meth) acrylate, N-allyl (meth) acrylamide, and N, N-diallyl (meth) acrylamide; diethylene glycol mono (diethylene glycol mono (d4). Polyethylene glycol mono (meth) acrylate such as meta) acrylate, triethylene glycol mono (meth) acrylate, tetraethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxypolyethylene glycol mono (meth) acrylate, polytri. Crosslinkable unsaturated monomer having a polyalkylene glycol group such as methylene glycol mono (meth) acrylate, polytetramethylene glycol mono (meth) acrylate, polyethylene glycol propylene glycol mono (meth) acrylate; diacetone acrylamide, N-isopropylacrylamide, Crosslinkable unsaturated monomer having N-substituted amide groups such as 2-acrylamide-2-methylpropanesulfonic acid and salts thereof; N, N-substituted amide groups such as N, N-dimethylacrylamide and N, N-diethylacrylamide. Crosslinkable unsaturated monomer having: divinylbenzene, 1,3,5-triacrylloylhexahydro-1,3,5-triazine, triallyl isocyanurate, triallyl trimellitate, triallylamine, tetramethylolmethanetetraacrylate, Examples thereof include aromatic polyvinyl-based cross-linkable unsaturated monomers such as tetraallyl pyromerylate.

The content of the component (d4) is not particularly limited, and is usually about 0.05 to 5 mol%, preferably 0.07 to 2.5 mol, with the total of all the monomer components as 100 mol% in terms of molar ratio. %, More preferably about 0.1 to 1 mol%.

Further, as the component forming the component (D), a chain transfer agent (d5) (hereinafter, referred to as the component (d5)) may be used. The component (d5) is not particularly limited, and is, for example, mercaptans such as 2-mercaptoethanol and n-dodecyl mercaptan; metharylsulfones such as sodium methallylsulfonate, potassium methallylsulfonate, and ammonium methallylsulfonate. Acid salts; aliphatic alcohols such as ethanol, isopropyl alcohol and pentyl alcohol; α-methylstyrene dimer, carbon tetrachloride, ethylbenzene, isopropylbenzene, cumene, 2,4-diphenyl-4-methyl-1-pentene and the like. Be done. These may be used alone or in combination of two or more. Among them, methallyl sulfonate is preferable, and sodium metharyl sulfonate is more preferable, from the viewpoint of adjusting the weight average molecular weight and viscosity of the component (D).

The content of the component (d5) is not particularly limited, but since the viscosity of the component (D) becomes relatively low even if it has a high molecular weight, the total of all the monomer components is usually 100 mol% in terms of molar ratio. Is about 0.05 to 5 mol%, preferably about 0.1 to 3 mol%, and more preferably about 0.2 to 2 mol%.

Further, the monomer component forming the component (D) contains a component (d6) (hereinafter referred to as (d6) component) other than the components (d1) to (d5) as long as the effect of the present invention is not impaired. Is also good. The component (d6) is not particularly limited, and for example, bis (meth) acrylamides such as methylol (meth) acrylamide, methylenebis (meth) acrylamide, and ethylenebis (meth) acrylamide; ethylene glycol di (meth) acrylate and diethylene glycol. Di (meth) acrylates such as di (meth) acrylates and polyethylene glycol di (meth) acrylates; divinyl esters such as divinyl adipate and divinyl sebacate; epoxy acrylates and urethane acrylates; styrene, α-methylstyrene, Aromatic monomers such as vinyltoluene; alkyls such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate (Meta) acrylate; Examples thereof include carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate. These may be used alone or in combination of two or more.

The content of the component (d6) is not particularly limited, and is preferably less than 5 mol%, more preferably less than 2.5 mol%, with the total of all monomer components being 100 mol% in terms of molar ratio.

The method for producing the component (D) is not particularly limited, and various known polymerization methods such as simultaneous polymerization, drop polymerization, and multi-step polymerization can be adopted. For example, JP2013-234390A and JP2015-052194. Examples thereof include the methods described in the publications. Further, in the polymerization, a polymerization initiator and a solvent can be used.

The polymerization initiator is not particularly limited, and is, for example, a persulfate such as ammonium persulfate, potassium persulfate, sodium persulfate; an azo-based polymerization initiator such as 2,2'-azobis (2-amidinopropane) hydrochloride. And so on. These may be used alone or in combination of two or more. Of these, ammonium persulfate, potassium persulfate, and 2,2'-azobis (2-amidinopropane) hydrochloride are preferable. Further, although optional, a reducing agent may be used in combination in terms of facilitating the generation of radicals of the organic peroxide. Examples of the reducing agent include sulfites such as sodium sulfite; hydrogen sulfites such as sodium hydrogen sulfite; triethanolamine, cuprous sulfate and the like. The amount used is also not particularly limited, and is usually about 0.05 to 2 parts by weight, preferably 0.1 to 0.5 parts by weight, based on a total of 100 parts by weight of the components (d1) to (d6). Degree.

As the solvent, water is usually preferable from the viewpoint that the monomer component is sufficiently dissolved or dispersed and does not adversely affect the polymerization reaction, but a hydrophilic organic solvent such as ethanol or isopropanol may be used in combination. Further, when the monomer component contains a component that is easily hydrolyzed, sulfuric acid or the like may be added.

Additives such as antioxidants, preservatives, antifoaming agents, chelating agents, bow glass, urea, and polysaccharides may be added to the component (D), if necessary.

As for the ratio of the number of amino groups and the number of carboxyl groups in the polymer obtained by the above-mentioned production method, the component (D) forms a polyion complex, the component (D) has a high yield in the paper, and the sizing agent is made high in the paper. Usually, (number of amino groups) / (number of carboxyl groups) = 1 to 15 in order to supplement the fixing.

The number of amino groups is determined according to the following (Formula 1) from the charged weight of the component (d2), the molecular weight (Mw), and the number of amino groups in the component (d2). When a plurality of (d2) components are used, the number of each amino group is calculated and the total value is obtained. The molecular weight (Mw) means "weight average molecular weight" (the same applies hereinafter).
(Equation 1) (Number of amino groups) = [{Weight of component (d2) charged} / {Molecular weight of component (d2) (Mw)}] x {Number of amino groups of component (d2)}

The number of carboxyl groups is determined according to the following (Equation 2) from the charged weight of the component (d3), the molecular weight (Mw), and the number of carboxyl groups in the component (d3). When a plurality of (d3) components are used, the number of each carboxyl group is calculated and the total value is obtained.
(Equation 2) (Number of carboxyl groups) = [{Weight of component (d3) charged} / {Molecular weight of component (d3) (Mw)}] x {Number of carboxyl groups of component (d3)}

From the same viewpoint, the ratio is preferably (amino group number) / (carboxyl group number) = 1 to 12, and more preferably 1 to 10.

The physical properties of the polymer are not particularly limited, and for example, the weight average molecular weight is preferably about 1 million to 8 million, more preferably about 1.5 million to 6 million. The weight average molecular weight is a value measured by a gel permeation chromatography (GPC) method (polyethylene glycol equivalent value).

Further, the viscosity at a concentration of 20% by weight and a temperature of 25 ° C. is preferably about 2,500 to 80,000 mPa · s, more preferably about 5,000 to 60,000 mPa · s.

The method for producing paper of the present invention includes a step of adding an emulsion sizing agent for papermaking containing components (A) and (B) to a pulp slurry.

The amount of the emulsion sizing agent for papermaking is usually 0.01 to 2% by weight, preferably 0.05 to 0.5% by weight, based on the solid content weight of the pulp. By setting the addition amount within the above range, the paper exhibits an excellent size effect.

The type of pulp slurry is not particularly limited, and examples thereof include chemical pulps such as hardwood pulp (LBKP) and softwood pulp (NBKP); mechanical pulps such as GP and TMP; and used paper pulps such as corrugated cardboard. These may be used alone or in combination of two or more.

Further, the method for producing paper of the present invention is also characterized in that the component (C) is not added as described above. When the component (C) is added, sulfate ions are generated in the pulp slurry, and hydrogen ions are combined to form hydrogen sulfide. As a result, odor is generated or the machine is corroded.

In the method for producing paper of the present invention, when the component (D) is added, the amount thereof is not particularly limited, but the sizing agent can be sufficiently fixed to the raw material pulp, so that the solid content weight of the pulp is increased. It is preferably about 0.05 to 4% by weight, more preferably about 0.1 to 2% by weight.

The order in which the component (D) is added to the pulp slurry is not particularly limited, and for example, it can be appropriately selected from the following.
(1) After adding the emulsion sizing agent for papermaking, the component (D) is added.
(2) After adding the component (D), an emulsion sizing agent for papermaking is added.
(3) The emulsion sizing agent for papermaking and the component (D) are added at the same time.
(4) An emulsion sizing agent for papermaking and a mixture of the component (D) are added.

In the present invention, (2) is preferable from the viewpoint of increasing the fixing rate of the emulsion sizing agent for paper making in paper and showing the paper having an excellent sizing effect.

In the method for producing paper of the present invention, a pH adjuster such as sulfuric acid or sodium hydroxide, a wetting paper strength agent, a retention agent, talc, clay, kaolin, titanium dioxide, calcium carbonate and the like are added as necessary. Is also good.

Examples of the paper obtained by the paper manufacturing method of the present invention include coated base paper, newspaper paper, liner, core, paper tube, printing writing paper, foam paper, PPC paper, cup base paper, inkjet paper, heat-sensitive paper and the like. Can be mentioned.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto. Unless otherwise specified, parts and% in Examples and Comparative Examples are based on weight.

(Melting point)
It was measured using differential scanning calorimetry (device name "EXSTAR DSC-6200", manufactured by Seiko Instruments Inc.).

(Acid value)
Measured according to JIS K 0070.

(viscosity)
The viscosity of the sample adjusted to 25 ° C. was measured using a Brookfield type viscometer (manufactured by Toki Sangyo Co., Ltd.).

(Volume average particle size)
The particle size was measured by a particle size measuring device by a laser diffraction / scattering method (device name "LASER DIFFRACTION PARTICLE SIZE ANALYZER SALD-7500 nano", manufactured by SHIMADZU).

(Weight average molecular weight)
The weight average molecular weight was measured under the following measurement conditions by the gel permeation chromatography (GPC) method.
GPC body: HLC-8220GPC manufactured by Tosoh Corporation
Column: 1 guard column PWXL and 2 GMPWXL manufactured by Tosoh Corporation (temperature 40 ° C)
Eluent: 0.5 mol / l acetic acid buffer (0.5 mol / l acetic acid (manufactured by Wako Pure Chemical Industries, Ltd.) + 0.5 mol / l sodium acetate (manufactured by Kishida Chemical Co., Ltd.) aqueous solution, pH about 4.2 )
Flow velocity: 0.8 ml / min Detector:
Viscotec TDA MODEL301 (concentration detector and 90 ° light scattering detector and viscosity detector (temperature 40 ° C)) RALLS method measurement sample: Ions so that the solid content concentration of the component (D) is 0.5% After diluting with exchange water, add an aqueous sodium hydroxide solution until the pH reaches 10 to 12, soak in a hot water bath at 80 ° C. or higher for 1 hour, adjust the pH to 6 to 8 with sulfuric acid, and 0.025% with an eluent. It was diluted with and measured.

Production Example 1-1 (Production of component (A-1))
210 parts (1 mol) of citric acid monohydrate and di-hardened beef amine (trade name "Armin 2HT", Lion Specialty Chemicals) in a reactor equipped with a stirrer, thermometer, reflux condenser and nitrogen introduction tube. 1000 parts (2 mol) of alkyl chain length ratio C16 / C18 = 40/60 manufactured by Co., Ltd. and 1252 parts of toluene were mixed, and the dehydration condensation reaction was continued for 20 hours under reflux of toluene. Toluene was distilled off from this reaction mixture under reduced pressure to obtain a dehydration condensation product (A-1) containing a diamide compound as a main component. The dehydration condensation had a melting point of 52 to 56 ° C. and an acid value of 55.7 mgKOH / g.

Production Example 1-2 (Production of component (A-2))
In the same reactor as in Production Example 1-1, 210 parts (1 mol) of citric acid monohydrate and stearyl alcohol (trade name “NAA-46”, stearyl alcohol / palmityl alcohol = 85/15 (%), 532 parts (2 mol) (manufactured by Nichiyu Co., Ltd.) was mixed, and the produced water was heated to 160 ° C. while being distilled off from the reaction system, and the dehydration condensation reaction was continued at the same temperature for 1.5 hours. The reaction product was cooled to obtain a dehydration condensation product (A-2) containing a diester compound as a main component. The dehydration condensation had a melting point of 48 to 51 ° C. and an acid value of 78.7 mgKOH / g.

Production Example 1-3 (Production of component (A-3))
In the same reactor as in Production Example 1-1, 176 parts (1 mol) of tricarbalyl acid and 532 parts (2 mol) of stearyl alcohol (trade name "NAA-46") were mixed and heated to 160 ° C. The dehydration condensation reaction was continued at temperature for 1.5 hours. The reaction product was cooled to obtain a dehydration condensation product (A-3) containing a diester compound as a main component. The dehydration condensation had a melting point of 48 to 51 ° C. and an acid value of 78.7 mgKOH / g.

Production Example 1-4 (Production of component (A-4))
176 parts (1 mol) of tricarbaryllic acid, 1000 parts (2 mol) of di-cured beef tallow amine (trade name “Armin 2HT”), and 1252 parts of toluene are mixed in the same reactor as in Production Example 1-1, and toluene is used. The reaction was continued for 20 hours under reflux. Toluene was removed from this reaction mixture under reduced pressure to obtain a dehydration condensation product (A-4) containing a diamide compound as a main component. The dehydration condensation had a melting point of 52 to 56 ° C. and an acid value of 53.0 mgKOH / g.

Production Example 1-5 (Production of component (A-5))
In the same reactor as in Production Example 1-1, 174 parts (1 mol) of t-aconitic acid, 1000 parts (2 mol) of di-cured beef tallow amine (trade name “Armin 2HT”), and 1252 parts of toluene were mixed. The reaction was continued for 20 hours under reflux of toluene. Toluene was distilled off from this reaction mixture under reduced pressure to obtain a dehydration condensation product (A-5) containing a diamide compound as a main component. The dehydration condensation had a melting point of 52 to 56 ° C. and an acid value of 53.0 mgKOH / g.

Production Example 2-1 (Production of component (B-1))
Reactor equipped with stirrer, thermometer, reflux condenser and nitrogen introduction tube, acrylamide 293.3 parts (76.9 mol%), itaconic acid 59.3 parts (8.5 mol%), metalyl sulfonic Sodium acid 25.4 parts (3.0 mol%), 2-ethylhexyl acrylate 29.6 parts (3.0 mol%), cyclohexyl methacrylate 77.3 parts (8.6 mol%), ion-exchanged water 711.3 The temperature of the mixture was raised to 50 ° C. under nitrogen gas bubbling with stirring of 784.9 parts of isopropyl alcohol. 11.0 parts of ammonium persulfate (APS) (0.9 mol% based on the total number of moles of polymerization components) was added as a polymerization initiator, the temperature was raised to 80 ° C., and the mixture was held for 180 minutes. Next, isopropyl alcohol was distilled off by blowing steam, and ion-exchanged water was added to obtain an aqueous solution of an emulsifier (B-1) having a solid content concentration of 24% and a viscosity of 1040 mPa · s.

Production Example 2-2 (Production of component (B-2))
4.0 parts of surfactant (Hitenol LA-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (1.0% by weight based on the total weight of the monomers) and hydroxy in the same reactor as in Production Example 2-1. Butyl acrylate 43.7 parts (8.0 mol%), 80% methacrylate 158.5 parts (38.9 mol%), itaconic acid 19.7 parts (4.0 mol%), sodium metalyl sulfonate 31 .7 parts (5.3 mol%), 140.0 parts of styrene (35.5 mol%), 26.4 parts of α-methylstyrene (5.9 mol%), 11.6 parts of butyl acrylate (2.4) Mol%), 1090.0 parts of ion-exchanged water, and 16.0 parts of α-methylstyrene dimer (4.0% by weight of total amount of monomer) as a chain transfer agent, and under nitrogen gas bubbling while stirring this mixed solution. The temperature was raised to 60 ° C. Add 16.0 parts of ammonium persulfate (APS) as a polymerization initiator (total amount of monomer to 4.0% by weight), raise the temperature to 90 ° C., hold for 100 minutes, and then use ammonium persulfate (APS) as a catalyst for post-polymerization. 4.0 parts (1.0% by weight of total amount of monomer) was further added, and the mixture was kept at 90 ° C. for 60 minutes. Next, 146.5 parts of a 48% aqueous sodium hydroxide solution (99 mol% neutralized carboxylic acid groups of methacrylic acid and itaconic acid) was added to neutralize methacrylic acid and itaconic acid, and ion-exchanged water was added to add solid content. An aqueous solution of an emulsifier (B-2) having a concentration of 25.2% and a viscosity of 53 mPa · s was obtained.

Production Example 2-3 (Production of component (B-3))
Hexaethylene glycol diacrylate 31.4 parts (1.5 mol%), acrylamide 287.6 parts (75.4 mol%), itaconic acid 59.3 parts (8) in the same reactor as in Production Example 2-1. .5 mol%), 25.4 parts (3.0 mol%) of sodium methallyl sulfonate, 29.6 parts (3.0 mol%) of 2-ethylhexyl acrylate, 77.3 parts (8.6 mol%) of cyclohexyl methacrylate. %), 711.3 parts of ion-exchanged water, 784.9 parts of isopropyl alcohol, and the temperature was raised to 50 ° C. under nitrogen gas bubbling while stirring the mixed solution. 11.0 parts of ammonium persulfate (APS) (0.9 mol% based on the total number of moles of polymerization components) was added as a polymerization initiator, the temperature was raised to 80 ° C., and the mixture was held for 180 minutes. Next, isopropyl alcohol was distilled off by blowing steam, and ion-exchanged water was added to obtain an aqueous solution of an emulsifier (B-3) having a solid content concentration of 24% and a viscosity of 1040 mPa · s.

Production Example 2-4 (Production of component (B-4))
In the same reactor as in Production Example 2-1: 4.0 parts of surfactant (Hitenol LA-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (1.0% by weight based on the total weight of the monomers), glycerin 43.7 parts (8.0 mol%) of monoacrylate, 122.2 parts (30.0 mol%) of 80% methacrylate, 58.6 parts (11.9 mol%) of itaconic acid, 31 parts of sodium metalylsulfonate .7 parts (5.3 mol%), 143.9 parts of styrene (36.5 mol%), 26.4 parts of α-methylstyrene (5.9 mol%), 11.6 parts of n-butyl acrylate (2) .4 mol%), 1090.0 parts of ion-exchanged water, 16.0 parts of α-methylstyrene dimer (4.0% by weight of total amount of monomer) as a chain transfer agent, and nitrogen gas while stirring this mixed solution. The temperature was raised to 60 ° C. under bubbling. 16.0 parts of ammonium persulfate (APS) (4.0% by weight of total monomer) was added as a polymerization initiator, the temperature was raised to 90 ° C. and held for 100 minutes, and then ammonium persulfate (APS) was used as a catalyst for post-polymerization. 4.0 parts (1.0% by weight of total amount of monomer) was further added, and the mixture was kept at 90 ° C. for another 60 minutes. Next, 146.5 parts of a 48% aqueous sodium hydroxide solution (99 mol% neutralized carboxylic acid groups of methacrylic acid and itaconic acid) was added to neutralize methacrylic acid and itaconic acid, and ion-exchanged water was added to add solid content. An aqueous solution of an emulsifier (B-4) having a concentration of 25.2% and a viscosity of 53 mPa · s was obtained.

Production Example 3-1
180 parts of (A-1) component is heated and melted, then 83.3 parts (solid content: 20.0 parts) of (B-1) component and 403 parts of warm water (80 ° C.) are added and mixed, and high-pressure emulsification is performed. An emulsion sizing agent for papermaking having a solid content concentration of 30% was prepared by emulsification with a machine (device name "APV", manufactured by GAULIN). The composition, viscosity and volume average particle size are shown in Table 1.

Production Example 3-2-3-10
Emulsion sizing agents for papermaking were prepared in the same manner as in Production Example 3-1 with the compositions shown in Table 1.

* 1: The amount of component (B) used is expressed in parts by weight of solid content.

(Component (B))
B-1: Emulsifier of Production Example 2-1 ・ B-2: Emulsifier of Production Example 2-2 ・ B-3: Emulsifier of Production Example 2-3 ・ B-4: Emulsifier of Production Example 2-4

Production Example 4-1 (Production of component (D-1))
A reactor equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas introduction tube and two dropping funnels was charged with 276 parts of ion-exchanged water, oxygen in the reaction system was removed through nitrogen gas, and then up to 90 ° C. It was heated. One dropping funnel contains 196 parts of acrylamide, 4.5 parts of dimethylaminoethyl methacrylate, 13.6 parts of an aqueous solution of benzyl chloride quaternized salt of 60% dimethylaminoethyl methacrylate, and 3.7 parts of itaconic acid. , N, N-Dimethylacrylamide 0.6 parts, sodium metharylsulfonate 3.6 parts, 62.5% sulfuric acid 2.2 parts, and ion-exchanged water 395 parts mixed solution (I) was charged, and pH was adjusted with sulfuric acid. Was adjusted to around 3.0. Further, a mixed solution (II) of 0.3 part of ammonium persulfate and 90 parts of ion-exchanged water was charged into the other dropping funnel. Next, the mixed solutions (I) and (II) were added dropwise from each dropping funnel into the reaction system over about 3 hours. After completion of the dropping, 0.4 part of ammonium persulfate and 10 parts of ion-exchanged water were further added and kept warm for 1 hour, and 95 parts of ion-exchanged water was added to obtain an aqueous solution of the component (D-1). The composition and physical properties are shown in Table 2.

Production Example 4-2-4-12 (Production of components (D-2) to (D-12))
The monomer composition shown in Table 2 was carried out in the same manner as in Production Example 4-1 to obtain aqueous solutions of the components (D-2) to (D-12), respectively.

The abbreviations in Table 2 indicate the following monomers.
AM: Acrylamide DM: N, N-Dimethylaminoethyl methacrylate DML: Benzyl chloride quaternary salt of dimethylaminoethyl methacrylate IA: Itaconic acid DMAA: N, N-dimethylacrylamide SMAS: Sodium methallyl sulfonate

Example 1
Collect an amount of N-UKP / corrugated cardboard waste paper = 20/80 by solid content weight, add tap water in an amount that makes the pulp concentration 2.0% with tap water, and use a beater to add 380 ml Canadian Standard Freeness. I beat it up. The beaten pulp slurry was further diluted with tap water to adjust the pulp concentration to 1.5%. To this pulp slurry, 0.3% of the paper strength enhancer (D-3) was added to the pulp solid content weight, and then 0.2% of the papermaking emulsion sizing agent of Production Example 3-1 was added, and then papermaking was performed. Paper was made by a machine (TAPPI Standard Sheet Machine (square type)) so as to have a basis weight of 80 g / m ² according to JIS P 8222. The papermaking pH at this time was 7.5. Next, the obtained wet paper was dehydrated with a roll press machine under the conditions of a linear pressure of 5.5 kg / cm and a feed rate of 2 m / min, and then dried at a temperature of 80 ° C. for 150 seconds using a rotary dryer. Immediately after drying the obtained paper, humidity is adjusted for 24 hours in a constant temperature and humidity (23 ° C, 50% relative humidity) environment, and humidity is adjusted for 1 week in a high temperature and high humidity (50 ° C, 90% relative humidity) environment. After that, the degree of bump size was measured for 2 minutes. The conditions and results are shown in Table 3.

Examples 2-31, Comparative Examples 1-3
Under the conditions shown in Table 3, the same procedure as in Example 1 was carried out to obtain papers. In Example 31, papermaking was performed by adding 0.2% of the papermaking emulsion sizing agent of Production Example 3-1 and then 0.3% of the paper strength enhancer to the pulp slurry with respect to the pulp solid content weight. did.

(Retention rate)
150 to 200 μg of paper of each Example and Comparative Example was cut out and measured by the pyrolysis gas chromatography-mass spectrometry (PY-GC / MS) method with the following equipment and temperature, and the obtained peak area and the following calibration curve were measured. The fixing rate (%) of the emulsion sizing agent in the paper was determined using a line.
<Device>
-Pyrolysis device: PY-2020D (manufactured by Frontier Lab Co., Ltd.)
-GC / MS body: HP6890 / 5973 (manufactured by Agilent Technologies Co., Ltd.)
-Column: UA-5 (manufactured by Frontier Lab Co., Ltd.)
<Conditions>
The starting temperature was measured at 225 ° C. and the heating rate was measured at 10 ° C./min for 10 minutes.
<Calibration curve>
As a standard sample, paper containing 0.01, 0.10, 0.50% of the emulsion sizing agent of Example 1 with respect to the solid content of the paper was prepared, measured under the above conditions, and the obtained peak area was measured. I asked.

(Odor)
The odor was measured assuming the papermaking process. 500 g of the pulp slurry prepared in Examples 1 to 31 and Comparative Examples 1 to 3 was collected in a DDJ (Dynamic Donelage Jar, 80 mesh), stirred at 600 rpm, and 150 g of filtered water was collected in a mayonnaise bottle from a pilot hole. I put the lid on. The obtained filtered water was allowed to stand in a constant temperature bath at a temperature of 40 ° C. for 5 days, and then the odor was smelled and evaluated according to the following evaluation criteria.
(Evaluation criteria)
○: No odor ×: There is an odor

SPN-811: Anionic rosin emulsion sizing agent (trade name "Size Pine N-811", manufactured by Arakawa Chemical Industry Co., Ltd.)
-SPK-931: Anionic alkyl ketene dimer emulsion sizing agent (trade name "Size Pine K-931", manufactured by Arakawa Chemical Industry Co., Ltd.)

Claims (2)

A trivalent or tetravalent carboxylic acid (a1), a monovalent aliphatic alcohol (a2-1) having an alkyl group or an alkenyl group having 6 to 22 carbon atoms, and an alkyl group having 6 to 22 carbon atoms and / Or for papermaking containing a dehydration condensate with at least one compound (a2) selected from the group consisting of an aliphatic amine (a2-2) having an alkenyl group and / or a salt (A) and an emulsifier (B) thereof. The step of adding the emulsion sizing agent to the pulp slurry was included, and the water-soluble aluminum compound (C) was not added .
Further, it is a (meth) acrylamide-based polymer of a monomer component containing (meth) acrylamide (d1), a cationic unsaturated monomer (d2) and an anionic unsaturated monomer (d3), and is an amino in the (meth) acrylamide-based polymer. A method for producing paper, which comprises a step of adding an amphoteric paper strength enhancer (D) in which the ratio of the number of groups to the number of carboxyl groups is (number of amino groups) / (number of carboxyl groups) = 1 to 15 . The method for producing paper according to claim 1, wherein the component (B) contains a polymer of a monomer component containing styrenes (b1) and / or (meth) acrylamide (b2).