TWI491782B - Waterborne emulsion type paper for surface sizing agent, surface sizing coating liquid and paper - Google Patents

Description

Surface sizing agent, surface sizing coating liquid and paper for aqueous emulsion type papermaking

The present invention relates to a surface sizing agent, a surface sizing coating liquid and paper for aqueous emulsion type papermaking.

The surface sizing agent for papermaking is a slurry applied to the surface of the paper to impart a sizing effect efficiently. The surface sizing agent for papermaking is used to disperse an alkyl ketene dimer and an alkenyl ketene dimer (hereinafter referred to as AKD) in water to make it cationic. The polymer of the functional group is dispersed in water or the like.

The AKD-based surface sizing agent obtained by dispersing AKD in water has a good sizing effect, but it is quite time-consuming until the sizing effect appears. Further, since the use of the AKD-based surface sizing agent lowers the friction coefficient of the paper, there is a problem that the use is limited. Moreover, since the AKD-based surface sizing agent has a problem in the stability against mechanical shear, there is also agglomeration which occurs when applied to paper, and the agglomerate becomes dirt, and for the manufacture of paper. Problems that cause adverse effects. Thus, in order to solve the problem of mechanical shearing, an AKD-based surface sizing agent of a specific copolymer was used. (Refer to Patent Document 1) However, the stability of the surface sizing agent for mechanical shearing is not sufficient, and the reduction in the friction coefficient cannot be sufficiently suppressed.

Further, as a method for suppressing a decrease in the friction coefficient, there has been proposed a surface sizing agent which controls the zeta potential within a specific range and is used in combination with a water-soluble polymer compound. (Refer to Patent Document 2) According to this method, although the friction coefficient is lowered, the sizing effect is deteriorated by the addition of the water-soluble polymer compound.

[Previous Technical Literature]

(Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. Hei 11-217795

Patent Document 2: Japanese Laid-Open Patent Publication No. 2003-221795

An object of the present invention is to provide a surface sizing agent for papermaking and a surface sizing coating liquid, which have a good sizing effect, and a reduction in the friction coefficient is suppressed, and the condensate generated when applied to paper can be reduced. And, the present invention provides a paper which is excellent in sizing effect.

In order to solve the above problems, the present inventors have conducted research and found that the use of a specific polymer, a water-soluble aluminum compound, an alkyl ketene dimer, and/or an alkenyl ketene dimer can solve the foregoing. Question.

In other words, the present invention relates to an aqueous emulsion type paper surface sizing agent, a surface sizing coating liquid, and a paper, the aqueous emulsion type paper surface sizing agent comprising: a polymer (C) which is made to contain hydrophobic The vinyl monomer (A) of the monomer (a1) is polymerized in the presence of a cationic water-soluble polymer (B); the water-soluble aluminum compound (D); and the alkyl ketene dimer and/or Or an alkenyl ketene dimer (E), the surface sizing coating liquid is such that the surface sizing agent for the aqueous emulsion type paper: starch (F) is a weight ratio of 0.1 to 20:99.9 to 80 ( The surface sizing agent for the aqueous emulsion type paper and the starch (F) are prepared by coating the surface sizing agent for the aqueous emulsion type paper or the surface sizing coating. Get it from the liquid.

According to the present invention, it is possible to provide a surface sizing agent for papermaking which has a good sizing effect and which suppresses a reduction in the friction coefficient and which can reduce coagulum generated when applied to paper.

[Preferred form of implementing the invention]

The present invention relates to a surface sizing agent for aqueous emulsion type paper comprising a polymer (C) (hereinafter referred to as component (C)) which comprises a hydrophobic monomer (a1) (hereinafter referred to as a component) The vinyl monomer (A) (hereinafter referred to as component (A)) of (a1)) is polymerized in the presence of a cationic water-soluble polymer (B) (hereinafter referred to as component (B)); A compound (D) (hereinafter referred to as component (D)); and an alkyl ketene dimer and/or an alkenyl ketene dimer (E) (hereinafter referred to as component (E)).

The characteristic of the component (A) is the component (a1). The component (a1) is not particularly limited as long as it is a hydrophobic radical polymerizable monomer, and a conventional one can be used. In particular, it is preferred to use a radical polymerizable monomer having a solubility in water (20 ° C) of 2% or less. Examples of the component (a1) include styrenes, α-olefins, vinyl esters, N-alkyl (meth) acrylamides, (meth) acrylonitriles, and (meth) acrylates. Dialkyl esters of maleic acid and dialkyl esters of fumaric acid.

Examples of the styrene include styrene, α-methylstyrene, vinyl toluene, methyl tertiary styrene, dimethyl styrene, and ethoxylated styrene. Hydroxystyrene, chlorovinyltoluene, and the like.

The α-olefins may, for example, be 2,4,4-trimethyl-1-pentene, 3-methyl-1-butene, 3-methyl-1-pentene or 4-methyl-1- Pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 1- Tetratetraene, 1-triene, and the like.

Examples of the vinyl esters include vinyl carboxylates having a carbon number of 5 to 10, vinyl propionate, and vinyl acetate.

Examples of the N-alkyl (meth) acrylamide include N,N-dimethyl(meth)acrylamide, N-methyl(meth)acrylamide, and N-ethyl (methyl). ) acrylamide, N-isopropyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, N-dodecyl (meth) acrylamide, N, N- Diisopropyl(meth)acrylamide, N,N-di-tert-butyl(meth)acrylamide, N,N-di-dodecyl(meth)acrylamide, N, N-di-tertiary octyl (meth) acrylamide, N,N-dicyclohexyl (meth) acrylamide, and the like.

The (meth)acrylic acid alkyl ester may, for example, be methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate or (meth)acrylic acid. Isobutyl ester, tertiary butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate, and the like.

These may be used alone or in combination of two or more. Among these, styrene, n-butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethyl (meth)acrylate are used from the viewpoint of sizing effect and emulsion stability. Hexyl ester is preferred.

The component (A) may contain other radical polymerizable monomer (a2) (hereinafter referred to as component (a2)) copolymerized with the component (a1) as needed. The component (a2) is not particularly limited, and a conventional one can be used. Specific examples thereof include (meth)acrylamide, a hydrophilic monomer having a hydroxyl group, a dialkylaminoalkyl (meth)acrylate, and a dialkylaminoalkyl (meth)acrylate. Amine, (meth)acrylic acid, itaconic acid, sodium (meth)allylsulfonate, glycidyl (meth)acrylate, and the like.

The hydrophilic monomer having a hydroxyl group may, for example, be hydroxyethyl (meth)acrylate, hydroxymethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, or (methyl) ) allyl alcohol and the like.

The dialkylaminoalkyl (meth)acrylate may, for example, be dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate or dimethyl (meth)acrylate. Aminopropyl propyl ester, dimethylaminobutyl (meth)acrylate, dipropylaminoethyl (meth)acrylate, dibutylaminoethyl (meth)acrylate, and the like.

The dialkylaminoalkylguanamine (meth)acrylate may, for example, be dimethylaminoethyl(meth)acrylamide, diethylaminoethyl(meth)acrylamide or dimethylamine. Aminopropyl (meth) acrylamide, dimethylaminobutyl (meth) acrylamide, dipropylaminoethyl (meth) acrylamide, dibutylaminoethyl (Methyl) acrylamide and the like.

The content of the component (a1) in the component (A) is not particularly limited, and is usually from about 80 to 100% by weight from the viewpoint of a good sizing effect. Further, the content of the component (a2) in the component (A) is preferably about 10% by weight or less.

The component (B) is not particularly limited as long as it is a water-soluble polymer having a cationic functional group, and a conventional one can be used. Specifically, a cationized starch, a water-soluble polymer obtained by cationically polymerizing a monomer component containing a cationic monomer, a cationized polyvinyl alcohol, or the like can be used. In particular, it is preferred to use a water-soluble polymer obtained by cationically polymerizing a monomer component containing a cationic monomer. In particular, from the viewpoint of the dispersion stability of the component (C) and the sizing effect, the hydrophobic monomer (b1) (hereinafter referred to as the component (b1)) and the dialkylamine (meth)acrylate are used. a cation used after copolymerization of an alkyl ester (b2) (hereinafter referred to as component (b2)) and/or a dialkylaminoalkylguanamine (b3) (hereinafter referred to as component (b3)) The polymer is preferred.

The component (b1) can be used in the same manner as the above component (a1).

The component (b2) may, for example, be N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate or N,N (meth)acrylate. - dimethylaminopropyl ester, N,N-dimethylaminobutyl (meth)acrylate, N,N-dipropylaminoethyl (meth)acrylate, N, (meth)acrylic acid, N-dibutylaminoethyl ester and the like.

The component (b3) may, for example, be N,N-dimethylaminoethyl(meth)acrylamide, N,N-diethylaminoethyl(meth)acrylamide, N,N- Dimethylaminopropyl (meth) acrylamide, N,N-dimethylaminobutyl (meth) acrylamide, N,N-dipropylaminoethyl (meth) propylene Indoleamine, N,N-dibutylaminoethyl (meth) acrylamide, and the like.

These may be used alone or in combination of two or more. Further, when the component (B) is prepared, other radical polymerizable component (b4) (hereinafter referred to as component (b4)) copolymerizable with the components (b1) to (b3) may be used in combination. The component (b4) may, for example, be a sulfonic acid group-containing monomer such as (meth)acrylic acid, (meth)acrylamide or sodium styrenesulfonate.

The amount of the component (b1) to the component (b3) to be used is not particularly limited, and is usually preferably (b1): [(b2) + (b3)] = 20 to 90: 80 to 10% by weight, for the following reasons: The component (C) has good dispersion stability and sizing effect. Further, when the component (b4) is used, the amount thereof is usually preferably 10% by weight or less based on the total amount of the component (b1) to the component (b4).

Component (B) is obtained by polymerizing the above polymerizable component. The polymerization method is not particularly limited, and a conventional method can be employed. When solution polymerization is employed, the solvent may be an aromatic hydrocarbon such as benzene or toluene; a lower ketone such as acetone or methyl ethyl ketone; or an alcohol such as n-propanol or isopropanol. The type of the polymerization initiator is not particularly limited, and a conventional one may be used, and any of the following may be used, for example, 2,2'-azobisisobutyronitrile and 2,2'-azobis-2. An azo compound such as 4-dimethylvaleronitrile; and organic peroxidation such as benzamidine peroxide, cumene hydroperoxide, tertiary butyl hydroperoxide, dicumyl peroxide, and dodecane oxide Other redox catalysts. Further, a chain transfer agent such as an α-methylstyrene dimer, a mercaptan or a secondary alcohol may be used in the polymerization. The conditions of the polymerization reaction are usually carried out at a reaction temperature of about 70 to 140 ° C and a reaction time of about 1 to 10 hours.

The molecular weight of the component (B) thus obtained is not particularly limited, and is usually preferably from 5,000 to 40,000 by weight average molecular weight (value converted by polystyrene obtained by gel permeation chromatography). It is: the dispersion stability of the component (C) and the sizing effect are good. Further, it is preferred to carry out the quaternization of one or all of the amine groups derived from the component (b2) and the component (b3) of the component (B) because the cationicity of the copolymer can be improved and the stability can be improved. Formation of emulsion and sizing performance. The degree of quaternization is preferably at least about 10 mol% of the component (b2) and/or the amine group of the component (b3) present in the copolymer of the component (B), and is about 50 to 100 mol%. good. Conventional materials can be used for the quaternizing agent used in the quaternization. Representative examples include benzyl chloride, methyl chloride, dimethyl sulfate, glycidol, chlorohydrin, allyl chloride, styrene oxide, propylene oxide, or epichlorohydrin. . The quaternization is usually carried out by holding at 50 to 90 ° C for 1 to 4 hours. Further, the quaternization is usually carried out after the preparation of the component (B), or may be carried out before the polymerization.

The component (C) used in the present invention is obtained by polymerizing the component (A) in the presence of the component (B). The polymerization method of the component (A) is not particularly limited, and a conventional method can be employed. The polymerization method is preferably an emulsion polymerization method because the obtained component (C) has good stability.

When the emulsion polymerization is carried out, since the component (B) has a function as an emulsifier, other emulsifiers may not be used, and a conventional emulsifier may be used in combination. Other emulsifiers can use cationic surfactants and nonionic surfactants. As the cationic surfactant, for example, lauryl trimethyl ammonium chloride, cetyltrimethyl ammonium chloride, octadecyl trimethyl ammonium chloride, tetradecyl chloride Base benzyl ammonium, octadecyl dimethyl benzyl ammonium chloride, and the like. These can be obtained from the following products, for example: CATIOGEN H, CATIOGEN L, manufactured by Kadaku Kogyo Co., Ltd.: QUARTAMIN 24P, QUARTAMIN 86P CONC, QUARTAMIN 60W, QUARTAMIN 86W, manufactured by Kao Corporation. Further, as the nonionic surfactant, for example, polyvinyl alcohol, polyoxyethylene ethyl ether, polyoxyethylidene phenyl ether, polyoxyethylidene phenyl ether, polyoxygen can be used. Ethyl sorbitan fatty acid ester may be used, and a nonionic surfactant having a reactive functional group in the molecule may be used, and one type or two or more types may be used alone.

The polymerization initiator used in the emulsion polymerization is not particularly limited, and any conventional one may be used. As the polymerization initiator, any of the following may be used, for example, a persulfate such as potassium persulfate or ammonium persulfate; and a water-soluble azo compound or other redox catalyst. Further, a chain transfer agent such as an α-methylstyrene dimer, a mercaptan or a secondary alcohol may be used in the polymerization. Further, a crosslinking agent may be used, and methylene bis(meth) acrylamide, exoethyl bis(meth) acrylamide, triene propylene, which is a 2 to 4 functional crosslinkable monomer, may be used. Isoisocyanurate, triallylamine, tetramethylolmethane tetraacrylate, tetraallyl pyromellitate, and the like. The emulsion polymerization is usually carried out at a temperature of about 70 to 100 ° C and a reaction time of about 1 to 10 hours.

In addition, the use amount of the component (A) and the component (B) is not particularly limited, and is usually a component (A) in terms of a weight ratio (calculated as a solid component): component (B) = 1:4 to 4 : 1 is better, the reason is: the stability of the component (C), the sizing effect is good.

The component (C) thus obtained is usually composed of the polymer of the component (A) and the component (B). The molecular weight of the component (C) is not particularly limited, and is usually a weight average molecular weight (a value obtained by polystyrene obtained by gel permeation chromatography) of about 50,000 to 500,000, preferably because of sizing effect. good.

The component (D) used in the present invention is not particularly limited, and a conventional one can be used. Specifically, for example, aluminum sulfate such as aluminum sulfate, basic aluminum sulfate or aluminum sulfate, aluminum chloride such as aluminum chloride or basic aluminum chloride, aluminum nitrate, and the like can be used. Among these, aluminum sulfate is particularly preferred because the sizing effect is good.

The component (E) used in the present invention is not particularly limited, and a conventional one can be used. As the component (E), for example, those represented by the general formula (1) can be used:

(wherein R ¹ and R ² are a saturated hydrocarbon group of C8 to C30 or an unsaturated hydrocarbon group of C8 to C30, and R ¹ and R ² may be the same or different). In the formula (1), the hydrocarbon group of R ¹ or R ² is, for example, an alkyl group such as an octyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group or an eicosyl group. Alkyl; octenyl, decenyl, dodecenyl, tetradecenyl, hexadecenyl, octadecyl, eicosyl, etc.; octylphenyl, nonylphenyl, nonylbenzene a substituted phenyl group; a substituted cyclohexyl group such as a fluorenylcyclohexyl group; an aralkyl group such as a phenylethyl group; and the like. Among these, a saturated hydrocarbon group of C10 to C25 and a C10 to C25 unsaturated hydrocarbon group are preferred, and a C14 to C22 saturated hydrocarbon group and a C14 to C22 unsaturated hydrocarbon group are particularly preferred. R ¹ and R ² are not limited to linear hydrocarbons, and may be branched or ring-shaped. Examples of such a component (E) include an octadecyl ketene dimer, a hexadecyl ketene dimer, a tetradecyl ketene dimer, a dodecyl ketene dimer, and the like. . Further, the ketene dimer may be a dimerization of a mixture of different fatty acids. The component (E) can also be emulsified by a known method to prepare an emulsion, and then mixed with the component (C) and the component (D). As the emulsification dispersing agent, for example, a cationized starch, a sodium lignosulfonate or a naphthalenesulfonic acid formalin condensate or the like can be used. The emulsification method of the component (E) is not particularly limited, and it is preferably a forced emulsification using a high-pressure homogenizer.

The amount of the component (C) to the component (E) to be used is not particularly limited, and the content of the component (E) is usually about 5 to 40% by weight, and the total amount of the component (C) and the component (D) is 95 to 60 by weight. The reason is about %, which is because the obtained surface sizing agent for papermaking has good stability and sizing effect. In addition, when the content ratio (solid content by weight) of the component (C) and the component (D) is (C)/(D)=20/80 to 80/20, the mixing with the component (E) can be improved. It is preferred because of its stability and sizing effect.

Further, the sizing agent for papermaking of the present invention may be emulsified by a conventional method after mixing the component (C), the component (D) and the component (E), or the component (C) and the component (D). The aqueous solution and the emulsion of the component (E) are mixed. Further, the order of mixing is not particularly limited.

The surface sizing coating liquid of the present invention is prepared by blending the surface sizing agent and starch (F) for papermaking in a weight ratio of 0.1 to 20:99.9 to 80 (calculated as a solid content) (hereinafter referred to as Ingredients (F)).

The component (F) is not particularly limited, and conventional materials such as oxidized starch, phosphated starch, enzyme modified starch, APS (ammonium persulfate) modified starch, cationized starch, and amphoteric starch can be used.

Further, the surface sizing coating liquid of the present invention may be added with various additives as needed. Examples of the additive include an antifoaming agent, an anti-slip agent, a preservative, a rust preventive, a thickener, a pH adjuster, an antioxidant, a film forming aid, a pigment, a dye, and the like.

By applying the surface sizing agent and the surface sizing coating liquid for papermaking of the present invention to a conventional paper, a paper excellent in sizing effect can be obtained. The paper for applying the surface sizing agent and the surface sizing coating liquid for papermaking of the present invention may, for example, be a newspaper web, a writing paper, a wallpaper, a PPC (Plain Paper Copier) paper, or a spray. Various papers such as ink paper, printing paper, and paperboard such as a liner and a core. The method of coating on the surface of the paper can be carried out by a conventional method. The coating method may be, for example, an impregnation method, a bar coater method, a curtain method, a spray method, a two-roll sizing pressurization method, a gate roller sizing pressurization, a SYM type sizing pressurization, or the like. Wait. Further, the coating amount of the surface coating agent for papermaking is usually about 0.01 to 2 g/m ² (solid content), preferably 0.04 to 1 g/m ² .

[Examples]

Hereinafter, the present invention will be specifically described by way of examples and comparative examples, but the present invention is not limited by the examples. In addition, in each example, unless otherwise indicated, a part and % are a weight basis.

[Synthesis Example 1]

In a flask equipped with a stirrer, a condenser, a dropping funnel, a nitrogen introduction tube, and a thermometer, 70 parts of styrene, 30 parts of dimethylaminoethyl methacrylate, 42.9 parts of isopropyl alcohol, and 2, 2 were fed. 2.5 parts of '-azobisisobutyronitrile, and polymerization was carried out at 80 to 85 ° C for 5 hours while stirring under a nitrogen gas stream. Next, 11.5 parts of acetic acid and 300 parts of water were added. Then, 17.7 parts of epichlorohydrin was added to the obtained copolymer, and the copolymer was subjected to quaternization at 80 ° C for 2 hours to prepare a cationic copolymerization compound, and then a predetermined amount of water was added to obtain a solid content. The concentration was adjusted to 20% to obtain a cationic water-soluble polymer (B1). The viscosity and pH of the obtained cationic water-soluble polymer (B1) are shown in Table 1. Further, the viscosity was added to a 225 mL of a melamine bottle, and the measurement was carried out at 25 ° C using a BM type viscometer (manufactured by TOKIMEC) (the same applies to the following examples).

[Synthesis Examples 2 to 8]

In addition to the type and amount of the monomer used in the synthesis, and the amount of the quaternizing agent using epichlorohydrin used in the fourth-stage synthesis, as shown in Table 1, The reaction was carried out in the same manner as in Synthesis Example 1 to obtain various cationic water-soluble polymers (B2 to B8) having a solid concentration of 20%. The viscosity and pH of the obtained cationic water-soluble polymer (B2 to B8) at 25 ° C are shown in Table 1.

The symbols in the table are as follows.

St: styrene, BA: butyl acrylate, MMA: methyl methacrylate, DMA: N,N-dimethylaminoethyl methacrylate, DMAA: N,N-dimethylaminopropyl propylene Indoleamine, ECH: epichlorohydrin

Further, the amounts used for the components (b1) to (b3) are parts by weight, and the amount of the quaternizing agent used is the molar ratio with respect to the component (b2) or the component (b3).

[Modulation Example 1]

80 parts of an alkyl ketene dimer derived from 65 parts per 35 parts of mixed fatty acid of stearic acid and palmitic acid, and 10% cationized starch paste previously gelatinized at 90 ° C for 1 hour in a beaker (Nitrogen content: 0.5 to 0.6%, oxidized starch is cation-modified by chlorinated propyl propyl trimethylammonium chloride), anionic dispersing agent (formalin condensate of naphthalene sulfonate, Kao) After 5.55 parts of a 40% aqueous solution and 131.3 parts of deionized water, the mixture was heated to 70 to 80 ° C, and pre-dispersed using a homomixer (manufactured by Special Machine Chemical Co., Ltd.), and then at the same temperature at 300 kg/cm. Under the conditions of ² , it was passed through a high-pressure homogenizer (APV, manufactured by GAULIN Co., Ltd.) twice to forcefully disperse it. Then, it was cooled to 25 ° C to obtain a ketene dimer emulsion having a solid concentration of 20%, a pH of 3.4, a viscosity of 10 mPa ‧ and a particle diameter of 0.7 μm.

[Modulation Example 2]

The same procedure was carried out except that the ketene dimer of Preparation Example 1 was changed to a ketene dimer derived from oleic acid, and a solid concentration of 20%, a pH of 3.5, a viscosity of 13 mPa·s, and a particle diameter of 0.6 were obtained. a gamma ketene dimer emulsion.

[Manufacturing Example 1]

Into a flask equipped with a stirrer, a condenser, a dropping funnel, a nitrogen inlet tube, and a thermometer, 125 parts of the cationic water-soluble polymer (B1) obtained in Synthesis Example 1 was added, and styrene as the hydrophobic monomer (A) was added. 50 parts, 50 parts of isobutyl acrylate, 11.1 parts (solid part 3 parts), and 340 parts of water as a cationic surfactant (manufactured by Kao Corporation), and added 2, 2' After 2.5 parts of azobis-2-carboxanylpropane (2,2'-azobis-2-amidinopropane) hydrochloride, the polymerization reaction was carried out at a reaction temperature of 70 ° C for 5 hours. Then, a predetermined amount of water was added to adjust the solid content concentration to 20% to obtain the component (C).

[Manufacturing Examples 2 to 17]

In the same manner as in Production Example 1, except that the types and amounts of the component (a1), the component (a2), and the component (B) were changed in the production example 1, the component (C) was prepared.

The symbols in the table are as follows.

St: styrene, BA: butyl acrylate, IBA: isobutyl acrylate, 2EHA: 2-ethylhexyl acrylate, AN: acrylonitrile, HEMA: hydroxyethyl methacrylate, QUARTAMIN 24P: Kao (share) "QUARTAMIN 24P" (dodecyltrimethylammonium chloride 27% solution)

*1: The weight ratio of the amount used to the hydrophobic monomer (a1) (converted in terms of solid content).

[Example 1]

100 g of the component (C) obtained in Production Example 1 and 100 g of a 20% aqueous solution of ammonium sulfate and 50 g of the AKD emulsion obtained in Preparation Example 1 were mixed to obtain a surface sizing agent for an emulsion type papermaking having a solid content concentration of 20%. The viscosity, pH, and average particle diameter of the obtained surface sizing agent for papermaking at 25 ° C are shown in Table 3.

[Examples 2 to 22]

In the same manner as in Example 1, except that the type and amount of the component (C), the component (D), and the component (E) were changed as shown in Table 1, the emulsion having a solid concentration of 20% was obtained. Surface sizing agent for papermaking. The viscosity, pH, and average particle diameter of the obtained surface sizing agent for papermaking at 25 ° C are shown in Table 3.

[Comparative Example 1]

The surface sizing agent for various papermaking having a solid content concentration of 20% was obtained in the same manner as in Example 1 except that ammonium sulfate was not mixed and the AKD emulsion obtained in Example 1 was prepared. The viscosity, pH, and average particle diameter of the obtained surface sizing agent for papermaking at 25 ° C are shown in Table 3.

[Comparative Examples 2 to 3]

The AKD emulsion obtained in Preparation Example 1 or 2 was used as it is. The viscosity, pH, and average particle diameter of the obtained surface sizing agent for papermaking at 25 ° C are shown in Table 3.

[Comparative Example 4]

The surface sizing agent for various papermaking having a solid content concentration of 20% was obtained in the same manner as in Example 1 except that the AKD emulsion obtained in Preparation Example 1 was not mixed. The viscosity, pH, and average particle diameter of the obtained surface sizing agent for papermaking at 25 ° C are shown in Table 3.

[Comparative Example 5]

The same procedure as in Example 1 was carried out except that ammonium sulfate was not mixed, and various surface sizing agents for papermaking having a solid content concentration of 20% were obtained. However, since thickening was observed after one month of standing, and stability was poor for a long period of time, no evaluation was made.

[Comparative Example 6]

The surface sizing agent for various papermaking having a solid content concentration of 20% was obtained in the same manner as in Example 1 except that the cationic aqueous solution polymer (B1) obtained in Synthesis Example 1 was used instead of the component (C). However, since thickening was observed after one month of standing, and stability was poor for a long period of time, no evaluation was made.

The amount of each component in the table is based on the total of the cationic polymer (C), the water-soluble aluminum compound (D), the alkyl ketene dimer, and/or the alkenyl ketene dimer (E). The weight ratio of the amount (converted in solid form).

(Performance test of surface sizing agent for papermaking)

The coating liquid was prepared by using the surface sizing agents for papermaking of each of Examples 1 to 22 and Comparative Examples 1 to 4, and applied to a neutral upper base paper, an acidic upper base paper, and paperboard according to the following method, and evaluated. performance. The results are shown in Tables 4 to 5.

(modulation of coating liquid)

The coating liquid is obtained by gelatinizing oxidized starch (Prince ACE A, manufactured by Prince Cornstarch Co., Ltd.) to a solid concentration of 15%, and using it to prepare a coating liquid, which provides a performance test, and the coating liquid contains solid content. The sulphurized starch was 7% by weight, and the surface sizing agent for papermaking prepared in Examples and Comparative Examples in the form of solid content was used.

(Stockigt sizing degree)

Stogit sizing (seconds) was measured in accordance with JIS P-8122. A larger value indicates a better sizing degree.

(Inkjet suitability evaluation (feathering test))

The assessment of the fading is performed on the coated paper subjected to the sizing treatment described above, and the line of the vertical intersecting line width is printed in a single color using a Canon inkjet printer PIXUS iP4200, with a naked eye to the outer edge of the line. The exudation was visually evaluated. The person who has no stunner is marked as 6, and the ink is oozing out so that the overall thickness of the line is marked as 1.

(Inkjet suitability evaluation (printing density test))

In the evaluation of the ink-jet suitability, solid printing was performed in a single color using each of the printing papers subjected to the above sizing treatment using a Canon inkjet printer PIXUS iP4200. Next, the concentration of the obtained printed portion was measured using a reflection densitometer (trade name "Gretag D186", manufactured by Gretag Macbeth Co., Ltd.). A larger value indicates a higher printing density.

(Water absorption test [Cobb method])

The bog value (g/m ² ) was measured in accordance with JIS P-8140. The contact time with water is 2 minutes, and the larger the value, the better the sizing degree.

(sliding angle [tilt method])

The static friction coefficient was measured in accordance with the tilt method of JIS P-8147. The smaller the sliding angle, the easier it is to slide.

(The average particle size)

The measurement was carried out by a laser diffraction scattering method using a particle size measuring device LASER DIFFRACTION PARTICLE SIZE ANALYZER SALD-2000J (manufactured by Shimadzu Corporation).

(pH)

The measurement was carried out by adjusting the temperature of the coating liquid to 40 ° C using a glass electrode pH meter (manufactured by Horiba, Ltd.).

(assessed on neutral top quality paper)

A neutral weight 70 g/m ² neutral paper was produced at pH 7.2 using the slurry prepared below.

Slurry preparation: 65 parts of L-BKP (360mL CSF), 35 parts of N-BKP (420mL CSF), 10 parts of calcium carbonate (TamaPearl 121, manufactured by Odomo Industries Co., Ltd.), neutral rosin sizing agent (SIZEPINE NT -78, Arakawa Chemical Industry Co., Ltd.) 0.2 parts, 1 part of aluminum sulfate, 1 part of cationized starch (Cato 3210, manufactured by NSC Japan), retention aid (Polytention 1000, Arakawa Chemical Industry Co., Ltd. ))) 0.03 parts.

On the obtained base paper, a coating liquid prepared by using the surface sizing agent for papermaking of the examples and the comparative examples was applied to both sides using a bar coater, and then passed through a rotary drum dryer at 105 ° C. The coated paper was obtained by drying, and the Stogit sizing degree and the inkjet suitability (fog property) were measured. The results are shown in Table 4. Further, the amount of the starch adhered and the amount of the solid sizing agent adhered to the surface are calculated from the weights before and after the application of the coating liquid.

(assessed on cardboard)

As the base paper, a cardboard base paper having a basis weight of 180 g/m ² was used.

On the base paper, a coating liquid prepared by using the surface sizing agent for papermaking of the examples and the comparative examples was applied to a base paper, and then dried by a rotary drum dryer at 105 ° C to obtain a coating. Cloth paper, measuring the water absorption (both method). The results are shown in Table 5.

Claims (5)

A surface sizing agent for aqueous emulsion type paper comprising: a polymer (C) which comprises a vinyl monomer (A) comprising a hydrophobic monomer (a1) in a cationic water-soluble polymer (B) In the presence of polymerization; a water-soluble aluminum compound (D); and an alkyl ketene dimer and/or an alkenyl ketene dimer (E), wherein: an alkyl ketene dimer and/or The content of the alkenyl ketene dimer (E) is 5 to 40% by weight, and the total amount of the polymer (C) and the water-soluble aluminum compound (D) is 95 to 60% by weight (calculated as solid content), The polymer (C) is obtained by polymerizing a vinyl monomer (A) containing a hydrophobic monomer (a1) in the presence of a cationic water-soluble polymer (B); a polymer (C) and a water-soluble aluminum. The content ratio (solid content by weight) of the compound (D) is (C) / (D) = 20 / 80 to 80 / 20, and the polymer (C) is a vinyl system containing the hydrophobic monomer (a1) The monomer (A) is obtained by polymerization in the presence of a cationic water-soluble polymer (B); and the content of the vinyl monomer (A) and the cationic water-soluble polymer (B) containing the hydrophobic monomer (a1) Ratio, by weight ratio (A): (B) = 1:4 to 4:1 The surface sizing agent for aqueous emulsion type paper according to claim 1, wherein the cationic water-soluble polymer (B) is (b1): [(b2) + (b3)] = 20 to a ratio of 90:80 to 10% by weight, comprising a hydrophobic monomer (b1) and a dialkylaminoalkyl (meth)acrylate (b2) and/or (meth) propylene The acid dialkylaminoalkylguanamine (b3), and some or all of the amine groups derived from the above (b2) and (b3) are subjected to quaternization. The surface sizing agent for aqueous emulsion type paper according to claim 1 or 2, wherein the water-soluble aluminum compound (D) is derived from aluminum sulfate, aluminum chloride, aluminum nitrate, and alkali. At least one selected from the group consisting of aluminum sulfate, basic aluminum chloride, aluminum sulfate, and the like. A surface sizing coating liquid which is formulated in such a manner that the surface sizing agent for starch making: starch (F) is in a weight ratio of 0.1 to 20:99.9 to 80 (calculated as solid content) The surface sizing agent for aqueous emulsion type paper according to any one of the items 1 to 3, and the starch (F). A surface sizing agent for aqueous emulsion type paper according to any one of claims 1 to 3, or a surface sizing coating liquid according to item 4 of the patent application; Got it.