JP5376204B2 - Barrier agent for resin-coated paper, polyethylene laminate coated paper, and silicone release paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new barrier agent forming a barrier layer excellent in any of barrier property, solvent resistance, and water resistance. <P>SOLUTION: Provided is the barrier agent for resin coated paper containing a copolymer neutralized salt (A) obtained by polymerizing a monomer group including a styrene (a1), &alpha;,&beta;-unsaturated dicarboxylic acid (a2), and polyfunctional vinyl monomer (a3). The barrier agent for resin coated paper containing the copolymer neutralized salt (A) and a neutralized salt of carboxymethylcellulose (B) shows an improved barrier performance. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

The present invention relates to a barrier agent used for various resin-coated papers such as polyethylene laminate-coated paper and silicone release paper, as well as polyethylene laminate-coated paper and silicone release paper.

  Paper is used for various purposes, but it may be used as a resin-coated paper whose surface is coated with various resins in consideration of contact with water or oil. Examples of the resin-coated paper include polyethylene laminate coated paper coated with molten polyethylene to impart waterproofness to the paper, and release paper coated with a silicone resin varnish to impart releasability and the like. The former is processed into a paper cup or a paper plate, and the latter is processed into an adhesive label mount.

By the way, since paper is an aggregate of pulp fibers and has many voids, various problems arise when the coating resin cannot be applied uniformly. For example, in the case of polyethylene laminate coated paper, if the polyethylene in the molten state permeates the paper too much, a continuous film of polyethylene cannot be obtained, so that the waterproof property and the like may be impaired. In the case of release paper, if a large amount of solvent (toluene, etc.) in the silicone resin varnish is absorbed by the paper, coating defects such as pinholes will occur in the silicone resin coating, resulting in reduced release properties. There is.

Therefore, a so-called barrier layer is sometimes provided prior to coating the coating resin for the purpose of increasing the barrier property by closing the paper. The barrier agent for constituting the barrier layer is generally roughly classified into an emulsion type and a non-emulsion type (aqueous solution type).

Examples of the emulsion-based barrier agent include a copolymer emulsion obtained by emulsion polymerization of a vinyl monomer in the presence of an alkali neutralized salt of a styrene-maleic acid copolymer and a low molecular weight emulsifier. Is known, and is particularly excellent in barrier properties (solvent resistance) against solvents (see Patent Document 1). However, emulsion-based barrier agents need to generate agglomerates during production or coating, require a large amount of heat to form a film, or increase the coating amount to obtain sufficient barrier properties. There are essential disadvantages. In addition, due to the low molecular weight emulsifier, the water resistance of the barrier layer may be insufficient.

On the other hand, as non-emulsion type barrier agents, various polymers such as polyvinyl alcohol, casein, acrylic copolymer, styrene-maleic anhydride copolymer neutralized salt are known. Among these, a carboxyl group-containing copolymer such as a styrene-maleic anhydride copolymer neutralized salt is particularly inexpensive and is widely used as a barrier agent for the polyethylene laminate coated paper (for example, patents). Reference 2). However, generally, the styrene-maleic anhydride copolymer neutralized salt has insufficient solvent resistance, so that it is difficult to use it as it is, for example, as a barrier agent for the release paper.

For example, various water-soluble polymers (acrylic copolymer, polyacrylamide, etc.) are blended as means for improving the barrier properties, water resistance, solvent resistance, etc. in a balanced manner in both emulsion and non-emulsion barrier agents. In any case, the effect is not sufficient, and there may be a problem in compatibility such as separation over time at room temperature.

JP 2001-262050 A JP 2003-155700 A

The main object of the present invention is to provide a non-emulsion type barrier agent for resin-coated paper, which can form a barrier layer excellent in barrier properties, solvent resistance and water resistance. Another object of the present invention is to provide a non-emulsion-type barrier agent for resin-coated paper, wherein the barrier agent for resin-coated paper is blended with a water-soluble polymer that is compatible with the barrier agent.

As a result of intensive studies, the present inventor has found that an aqueous solution type (that is, a non-emulsion type not using an emulsifier) barrier agent having the following constitution is suitable.

That is, the present invention polymerizes a monomer group including styrenes (a1), α, β unsaturated dicarboxylic acids (a2), and polyfunctional vinyl monomers (a3) in toluene as a chain transfer organic solvent. A barrier agent for resin-coated paper containing a copolymer neutralized salt (A) having a number average molecular weight of 10,000 to 2,000,000 and not containing a carboxymethylcellulose neutralized salt (B) ; styrenes (a1), α , Β-unsaturated dicarboxylic acids (a2), and a monomer group containing a polyfunctional vinyl monomer (a3) are polymerized in toluene as a chain transferable organic solvent and have a number average molecular weight of 10,000 to 2,000,000. polymer neutralized salt (a) and carboxymethylcellulose neutralized salt (B) in a solid weight ratio of 95: 5 to 70: resin coated paper containing in a range of 30 barrier agent;該樹Comprising a coated paper for barrier agent as a barrier layer, a polyethylene laminated coated paper; becomes a barrier agent for the resin-coated paper as a barrier layer, a silicone release paper relates.

According to the barrier agent of the present invention, a barrier layer that is excellent in any of barrier properties, solvent resistance, and water resistance can be formed. In addition, the second barrier agent of the present invention is excellent in compatibility and hardly separates even if stored for a long time. The barrier agent of the present invention is suitable as a barrier agent for various resin-coated papers (polyethylene laminate coated paper, release paper, offset printing paper, gravure printing paper, inkjet printing paper, cup base paper, etc.).

The first barrier agent of the present invention includes styrenes (a1) (hereinafter referred to as component (a1)), α, β unsaturated dicarboxylic acids (a2) (hereinafter referred to as component (a2)), and polyfunctional vinyl monomers. It is characterized by containing a copolymer neutralized salt (A) (hereinafter referred to as component (A)) obtained by polymerizing a monomer group containing (a3) (hereinafter referred to as component (a3)). In addition, the monomer group may contain a copolymerizable monomer other than the components (a1) to (a3) (hereinafter referred to as component (a4)).

  As the component (a1), various known compounds can be used without particular limitation. Specific examples include styrene, α-methyl styrene, t-butyl styrene, dimethyl styrene, acetoxy styrene, hydroxy styrene, vinyl toluene, chlorovinyl toluene, styrene sulfonic acid, α-methyl styrene sulfonic acid, and the like. These can be used alone or in combination of two or more. Among these, styrene is preferable from the viewpoint of water resistance.

As the component (a2), various known compounds can be used without particular limitation. Specifically, for example, maleic anhydride, maleic acid, itaconic acid, fumaric acid, muconic acid, citraconic acid and the like, and alkyl groups having about 1 to 18 carbon atoms (linear, branched, cyclic) Any of which may be used may be an ester obtained by reacting an alcohol having 1), or one kind may be used alone, or two or more kinds may be used in combination. The ester refers to a diester or a monoester. Among these, at least one selected from the group consisting of maleic acid, maleic anhydride, and maleic acid esters is preferable from the viewpoint of the barrier property.

  The component (a2) may be previously neutralized with various neutralizing agents. Examples of the neutralizing agent include alkali metal compounds [sodium hydroxide, potassium hydroxide, etc.], ammonia [ammonia, ammonium carbonate, etc.], aliphatic amines having about 1 to 12 carbon atoms [monomethylamine, dimethylamine, Trimethylamine, monoethylamine, diethylamine, monobutylamine, etc.), alicyclic amines [cyclohexylamine, etc.], aromatic amines [aniline, etc.], etc., and one type may be used alone or two or more types may be used. it can.

The component (a3) is essential for the purpose of introducing a crosslinked structure or a branched structure into the component (A) and improving the barrier property, water resistance and the like. As this (a3) component, various well-known things, especially a 2-4 functional vinyl monomer can be used conveniently. Specifically, bifunctional vinyl monomers [di (meth) acrylates (diol di (meth) acrylates such as 1,6 hexanediol diacrylate, ethylene glycol di (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol] Di (meth) acrylate, alkylene glycol di (meth) acrylate such as diethylene glycol di (meth) acrylate), bis (meth) acrylamides (methylene bis (meth) acrylamide, ethylene bis (meth) acrylamide, hexamethylene bis (meth) acrylamide Etc.), divinyl esters (divinyl adipate, divinyl sebacate, etc.), diallyldimethylammonium, diallyl phthalate, diallyl chlorendate, divinylbenzene, etc.) Vinyl monomers [1,3,5 triacryloylhexahydro 1,3,5 trione, pentaerythritol triacrylate, 1,3,5 triacryloylhexahydro-S-triazine, triallyl isocyanurate, triallylamine, triallyl Trimellitate, N, N-diallylacrylamide, trivinylbenzene, etc.], tetrafunctional vinyl monomer [tetramethylolmethane tetraacrylate, tetraallyl pyromellitate, N, N, N ′, N′-tetraallyl-1,4 Diaminobutane, tetraallylamine salt, tetraallyloxyethane, etc.] and the like. These can be used alone or in combination of two or more.

  As the component (a4), various known compounds can be used without particular limitation. Specifically, for example, α-olefins [1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 1-tetracosene, 1- Triacontene, diisobutylene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, cyclohexene, methylcyclohexene, vinylcyclohexane, 4-vinylcyclohexene, cyclopentene, methylcyclopentene, etc.) (Meth) acrylic acid alkyl esters having an alkyl group having 1 to 18 carbon atoms [methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, ( (Meth) acrylic acid sec-butyl, (meth) acrylic acid tert- Chill, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, (meta ) Octadecenyl acrylate, icosyl (meth) acrylate, docosyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, etc.], hydroxyalkyl (meth) acrylate [(meth) acrylic acid 2- Hydroxymethyl, 2-hydroxyethyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-methacrylic acid (2-) Hydroxybutyl, glycerol mono (meth) acryl Rate, pentaerythritol mono (meth) acrylate, (meth) allyl alcohol, etc.], amide unsaturated monomers [(meth) acrylamide, N-methylol (meth) acrylamide, N-ethyl (meth) acrylamide, N- Butyl (meth) acrylamide, N-octyl (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-2-hydroxyethyl (meth) acrylamide, N, N-dihydroxyethyl (meth) acrylimide, (meth) acrylamide glycolic acid, etc.], aminoalkyl unsaturated monomers [aminoethyl (meth) acrylate, (Meth) acrylic acid Propyl, aminobutyl (meth) acrylate, N-methylaminoethyl (meth) acrylate, N-methylaminopropyl (meth) acrylate, N-methylaminobutyl (meth) acrylate, N (meth) acrylic acid, N-dimethylaminoethyl, N, N-dimethylaminopropyl (meth) acrylate, N, N-dimethylaminobutyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N (meth) acrylic acid , N-diethylaminopropyl, N, N-diethylaminobutyl (meth) acrylate], polyoxyalkylene unsaturated monomers [polyoxyalkylene (meth) acrylic acid esters, polyoxyalkylene glycerin (meth) acrylic Acid esters, polyoxyalkylene monoalkyl (meth) acrylic acid Steal, polyoxyalkylene (meth) allyl ether, polyoxyalkylene glycerin (meth) allyl ether, etc.], sulfonic acid unsaturated monomers [vinyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfone Acid, (meth) allylamide-N-methylsulfonic acid, (meth) acrylamide phenylpropanesulfonic acid, (meth) allylsulfonic acid, sulfoethyl (meth) acrylate, sulfopropyl (meth) acrylate, (meth) acrylic acid sulfo 2-hydroxypropyl and the like], sulfate ester unsaturated monomers [sulfuric ester of hydroxyethyl (meth) acrylate, hydroxypropyl sulfate of (meth) acrylate, polyoxyalkylene sulfate of (meth) acrylate, sulfuric acid (Meth) allyl ester, a And the like, and the like can be used singly or in combination of two or more.

  The use amount of the components (a1) to (a4) is not particularly limited, and can be appropriately determined in consideration of the workability during the production of the component (A), the barrier properties, water resistance, and the like. Specifically, when the total amount of the components (a1) to (a4) is 100% by weight, the component (a1) is usually about 30 to 70% by weight (preferably 40 to 60% by weight), (a2 ) Component is about 70-30% by weight (preferably 60-40% by weight), (a3) component is about 0.01-2% by weight (preferably 0.01-1% by weight), and (a4) component is 0 About 1% by weight.

The manufacturing method of (A) component is not specifically limited, Various well-known methods can be utilized. For example, in the case of the solution polymerization method, first, the components (a1) to (a3) (and the component (a4) as necessary) are added in the presence of a polymerization initiator and a solvent (water or an organic solvent). A copolymer is produced by a radical polymerization reaction at about 80 to 130 ° C. for about 1 to 10 hours. When a neutralized product is used as the component (a2), the copolymer is directly used as the component (A). Otherwise, the obtained copolymer (unneutralized product) is used. (A) component can be obtained by neutralizing the above-mentioned various neutralizing agents, and both methods can be used in combination.

  As the polymerization initiator, various known ones can be used without particular limitation. Specifically, for example, organic peroxide initiators [benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, t-butyl peroxy 2-ethylhexanoate, dicumyl peroxide, lauroyl peroxide Etc.], azo initiators [2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-methylvaleronitrile, etc.], and these in combination with a reducing agent (sodium hydrogen sulfite, etc.) Redox initiators and the like can be mentioned, and these can be used alone or in combination of two or more. Although the usage-amount of a polymerization initiator is not specifically limited, Usually, it is about 0.1 to 10 weight% with respect to the total weight of a monomer group.

  As the organic solvent, various known solvents can be used without particular limitation. Specific examples include water, aromatic hydrocarbon solvents (benzene, toluene, etc.), ketone solvents (acetone, methyl ethyl ketone, etc.), alcohol solvents (n-propyl alcohol, isopropyl alcohol, etc.) and the like. These can be used singly or in combination of two or more. Although the usage-amount of a solvent is not specifically limited, Usually, it is the range from which the solid content concentration of a radical polymerization reaction system will be about 20 to 60 weight%.

In general, a non-crosslinked and / or unbranched copolymer (that is, a linear copolymer) has a relatively high weight average molecular weight when produced in a chain transfer organic solvent. In general, the barrier property tends to be small, and even when such a copolymer is used, sufficient barrier properties cannot be achieved. Here, the “chain transfer organic solvent” refers to a solvent that can serve as a chain carrier in the radical polymerization reaction (chain reaction) among the organic solvents described above (for example, toluene, isopropyl alcohol, etc.). However, (A) component of the present invention, since the copolymer constituting it is as essential constituting the (a3) component in the case where the copolymer is prepared in toluene is chain transfer organic solvents The weight average molecular weight can be maintained to such an extent that a sufficient barrier property can be exhibited.

The number average molecular weight of the resulting component (A) (in terms of polystyrene by gel permeation chromatography), the barrier properties and the like of the viewpoint by Ri 10,000 to 2,000,000, preferably 60,000 to 100,000. Moreover, pH is about 5.0-11.0 normally.

  Further, the Brookfield viscosity of the component (A) is not particularly limited, but is usually 1000 to 5000 mPa.s. s (10% by weight aqueous solution, 25 ° C.), particularly 1500 to 3000 mPa.s. It is preferably s (10% by weight aqueous solution, 25 ° C.). 1000 mPa.s. If it is less than s, the barrier property may be insufficient. Also, 5000 mPa.s. When s is exceeded, it exists in the tendency which becomes difficult to be compatible with the below-mentioned carboxymethylcellulose neutralization salt (B) component. The viscosity measurement was performed using a rotor no. 3 and rotating at 12 rpm.

Second barrier agent of the present invention, the first barrier agent, for the purpose of further improving the barrier property, carboxymethylcellulose neutralized salt (B) (hereinafter, (B) referred to as the component) and, in view of barrier property and the like From a solid content weight ratio of 95: 5 to 70:30 .

The component (B) is not particularly limited, and various known neutralized carboxymethyl cellulose salts can be used. In addition, as the said neutralization salt, alkali metal salts, such as sodium salt, are mentioned, for example. Moreover, the carboxymethyl substitution degree per glucose residue of (B) component is about about 0.25-0.50 normally.

In the present invention, the viscosity (Brookfield viscosity) of the component (B) is not particularly limited, but is usually 1000 to 20000 mPa.s. s (1% by weight aqueous solution, 25 ° C.), particularly 2000 to 15000 mPa.s. It is preferably s (1% by weight aqueous solution, 25 ° C.). The viscosity is 1000 mPa.s. If it is less than s, the barrier property may be insufficient, and 20000 mPa.s. If it exceeds s, the component (A) tends to be difficult to be compatible. The viscosity measurement was performed using a rotor no. 3 and rotating at 6 rpm.

The second barrier agent can be prepared by mixing the component (A) and the component (B) by various known means. The viscosity of the barrier agent itself (Brookfield viscosity) is usually 10 to 300 mPa.s. It is about s (4 weight% aqueous solution, 25 degreeC). The viscosity measurement was performed using a rotor no. 2 and at a rotational speed of 60 rpm.

Although content of the said (A) component in a 2nd barrier agent and (B) component is not specifically limited, From viewpoints, such as barrier property, it is about 95: 5-70: 30 normally by solid content weight ratio. . Moreover, although the total weight% (concentration) of the said (A) component and (B) component in the barrier agent of this invention is not specifically limited, Usually, it is about 0.1 to 10 weight%.

Various known additives can be appropriately used in combination with the barrier agent of the present invention. Specific examples include starch, polyvinyl alcohol, antifoaming agent, anti-slip agent, antiseptic, rust inhibitor, pH adjuster, antioxidant, pigment, dye, lubricant, and the like. Or in combination of two or more.

The barrier agent of the present invention is used for forming barrier layers of various resin-coated papers. Examples of the base material (base paper) forming the resin-coated paper include polyethylene laminate coated paper, release paper, offset printing paper, gravure printing paper, inkjet printing paper, and cup base paper. Examples of the pulp constituting the base material include softwood kraft pulp, hardwood kraft pulp, groundwood pulp, thermomechanical pulp, chemithermomechanical pulp, and deinked pulp. Moreover, when manufacturing this base material, a filler, a size agent, a paper strength improver, a yield improver, a dye, etc. may be used as needed.

The barrier layer can be formed by applying the barrier agent of the present invention to the substrate (base paper) by various known means. Examples of the coating means include a size press, a gate roll coater, and a bar coater. Moreover, the coating amount on paper is not particularly limited, but usually 0.1 to 3 g / m ² as a dry solid content.
The degree is preferably about 0.05 to 0.5 g / m ² .

  The polyethylene laminate coated paper of the present invention is obtained by laminating a barrier layer made of the barrier agent according to the present invention and a polyethylene laminate layer on at least one surface of the substrate. The polyethylene laminate layer can be obtained, for example, by applying the barrier agent according to the present invention to the substrate and drying it, and then melt-coating a polyethylene film.

  Moreover, the silicone release paper of this invention laminates | stacks the barrier layer which consists of the barrier agent based on this invention, and the silicone release layer on the at least one surface of the said base material. The silicone release layer can be obtained, for example, by applying the barrier agent according to the present invention to the substrate and drying it, and then applying a silicone release agent solution (toluene solution or the like).

EXAMPLES Hereinafter, although this invention is demonstrated concretely through an Example, the scope of the present invention is not limited to these Examples. “%” Means% by weight, and “part” means part by weight. The “weight average molecular weight” is determined by gel permeation chromatography (product name “HLC8120GPC”, manufactured by Tosoh Corporation); column names “TSKgelSuperH-RC, TSKgel”
Super HM-L ", manufactured by Tosoh Corporation; developing solvent THF) means a polystyrene equivalent value measured.

Production Example 1
In a flask equipped with a stirrer, condenser, nitrogen inlet tube and thermometer, 444 parts of styrene, 450 parts of maleic anhydride, 5549 parts of toluene, 8.5 parts of divinyl adipate, lauroyl peroxide (trade name) 6.5 parts of “Parroyl L” (manufactured by NOF Corporation) was charged, and a radical polymerization reaction was carried out at 80 to 85 ° C. for 2 hours. After completion of the reaction, 1350 parts of water was added and toluene was distilled off by steam distillation. Next, 2250 parts of water and 342 parts of 25% aqueous ammonia were added to obtain an aqueous solution (solid content concentration 10%) of a copolymer neutralized salt (hereinafter referred to as component (A-1)). The weight average molecular weight of the component (A-1) was 67650, the pH of the aqueous solution was 6.4, and the viscosity was 1440 mPa · s.

Production Example 2
A flask similar to Production Example 1 was charged with 444 parts of styrene, 450 parts of maleic anhydride, 5549 parts of toluene, and 1.57 parts of 57% divinylbenzene. Next, after the temperature of the reaction solution was set to 70 ° C., a mixed solution consisting of 2.68 parts of lauroyl peroxide (trade name “Perroyl L”, manufactured by NOF Corporation) and 60 parts of toluene was charged. After the reaction temperature rose to 100 ° C. or higher due to the heat of polymerization, the mixture was kept for 2 hours to carry out a radical polymerization reaction. After completion of the reaction, 1350 parts of water was added and toluene was distilled off by steam distillation. Subsequently, 2250 parts of water and 342 parts of 25% ammonia water were added to obtain an aqueous solution (solid content concentration 10%) of a copolymer neutralized salt (hereinafter referred to as component (A-2)). The weight average molecular weight of the component (A-2) was 106500, the pH of the aqueous solution was 6.4, and the viscosity was 2200 mPa · s.

Production Example 3
In a flask similar to Production Example 1, 444 parts of styrene, 450 parts of maleic anhydride, 5549 parts of toluene, 6.3 parts of 1,6 hexanediol diacrylate, lauroyl peroxide (trade name “Perroyl L”, 6.5 parts of NOF Corporation) was charged, and a radical polymerization reaction was carried out at 80 ° C. to 85 ° C. for 2 hours. After completion of the reaction, 1350 parts of water was added and toluene was distilled off by steam distillation. Subsequently, 2250 parts of water and 342 parts of 25% ammonia water were added to obtain an aqueous solution (solid content concentration 10%) of a copolymer neutralized salt (hereinafter referred to as component (A-3)). The weight average molecular weight of the component (A-3) was 72750, the pH of the aqueous solution was 6.8, and the viscosity was 1750 mPa · s.

Production Example 4
In a flask similar to Production Example 1, 444 parts of styrene, 360 parts of maleic anhydride, 158 parts of normal butyl monoester maleic anhydride, 5549 parts of toluene, 6.3 parts of 1,6 hexanediol diacrylate, 6.5 parts of lauroyl peroxide (trade name “Perroyl L”, manufactured by NOF Corporation) was charged, and a radical polymerization reaction was performed at 80 ° C. to 85 ° C. for 2 hours. After completion of the reaction, 1350 parts of water was added and toluene was distilled off by steam distillation. Subsequently, 2300 parts of water and 308 parts of 25% ammonia water were added to obtain an aqueous solution (solid content concentration 10%) of a copolymer neutralized salt (hereinafter referred to as component (A-4)). The weight average molecular weight of the component (A-4) was 85000, the pH of the aqueous solution was 6.9, and the viscosity was 2210 mPa · s.

Comparative production example 1
In the same flask as in Production Example 1, 444 parts of styrene, 450 parts of maleic anhydride, 5549 parts of toluene, and 5.9 parts of benzoyl peroxide (trade name “Nyper BW”, manufactured by NOF Corporation) are charged. The radical polymerization reaction was carried out at 80 to 85 ° C. for 2 hours. After completion of the reaction, 1350 parts of water was added and toluene was distilled off by steam distillation. Next, 2250 parts of water and 342 parts of 25% aqueous ammonia were added to obtain an aqueous solution of a non-crosslinked copolymer neutralized salt (hereinafter referred to as component (A), solid content concentration of 10%). The component (a) had a weight average molecular weight of 35400, a pH of 6.8, and a viscosity of 510 mPa · s.

In Table 1, St represents styrene, MA-AH represents maleic anhydride, MA-nB represents normal butyl monoester maleate, ADV represents divinyl adipate, DVB represents divinylbenzene, and 1.6 HDA represents 1,6 hexanediol acrylate. .

As the component (B), carboxymethyl cellulose neutralized salts (B-1) to (B-3) shown in Table 2 were used.

In Table 2, all of Serogen 3H, Serogen BSH6 and Serogen MP980C are carboxymethylcellulose sodium salts manufactured by Daiichi Kogyo Seiyaku Co., Ltd. In addition, these Brookfield viscosities are the same as that of the rotor No. 3 is a value measured at a rotational speed of 12 rpm.

Biscarex HV30 is an alkali thickening acrylic copolymer emulsion (solid content 1.0 wt%, pH 8.9) manufactured by Nichigo Movinyl Co., Ltd. KW-504 is an aqueous polyacrylamide polymer solution (solid content: 1.0% by weight) manufactured by Arakawa Chemical Industries, Ltd. In all cases, the viscosity was measured at 25 ° C., rotor No. 3. Brookfield value measured at 12 rpm.

Examples 1-4
The aqueous solutions (A-1) to (A-4) were used as they were as barrier agents.

Examples 5-20
The component (A-1) and the component (B-1) were mixed at a solid content weight ratio of 90:10 to prepare a barrier agent. Subsequently, the appearance was visually evaluated, and the compatibility was judged according to the following criteria. The combinations shown in Table 3 were also evaluated in the same manner. The results are shown in Table 3.
○: No separation even after standing at 25 ° C. for 1 day ○ Δ: Separation after standing at 25 ° C. for 12 hours.
X: Separated immediately after mixing at 25 ° C

Comparative Examples 1-4
The aqueous solutions of the components (B-1) to (B-3) and the aqueous solution of the component (A) were used as they were as barrier agents.

Comparative Examples 5-7
A barrier agent was prepared by mixing the aqueous solution of the component (A) and the aqueous solution of the component (B-1) so that the solid content weight ratio was 90:10. Moreover, the aqueous solution of the said (A-3) component and the said biscalex HV30 were mixed so that it might become 90:10 by solid content weight ratio, and the barrier agent was prepared. Further, the aqueous solution of the component (A-3) and the KW-504 were mixed in the same manner, and the compatibility was judged. Subsequently, the external appearance was visually evaluated for each, and the compatibility was evaluated based on the above criteria. The results are shown in Table 3.

(Creating coated paper)
Bar coater No. 4 was used for the barrier agent of each Example and Comparative Example on one side of neutral fine base paper (basis weight 92 g / m ² ) and acidic fine uncoated base paper (basis weight 72 g / m ² ). The coating amount was about 0.25 g / m ^{2 in} terms of solid content. Next, the obtained coated paper was dried at 105 ° C. for 1 minute and conditioned in an atmosphere of 23 ° C. and 50% RH for 24 hours to obtain a coated paper for test. Further, other test coated papers were obtained by the combinations shown in Table 3.

(Barrier properties)
About each coated paper for a test, the air permeability was measured according to JISP8117 using the Oken type smoothness air permeability tester. In addition, blank tests were performed on the neutral high-quality base paper and the acidic high-quality base paper itself (Reference Examples 1 and 2). Air permeability is an indicator of barrier properties. The results are shown in Table 3.

(Solvent resistance)
5 μL of toluene was dropped on the coated surface of each test paper, and the time until the liquid completely penetrated was measured. Moreover, the blank test was implemented about neutral quality base paper and acidic quality base paper itself. The results are shown in Table 3.

(water resistant)
5 μL of deionized water was dropped on the coated surface of each test paper. According to the Tappi No 32-2 water absorption test, the time until the liquid droplet completely penetrated was measured. Moreover, the blank test was implemented about neutral quality base paper and acidic quality base paper itself. The results are shown in Table 3.

Claims (8)

Number average obtained by polymerizing a monomer group including styrenes (a1), α, β unsaturated dicarboxylic acids (a2), and polyfunctional vinyl monomers (a3) in toluene as a chain transferable organic solvent A barrier agent for resin-coated paper , which contains a copolymer neutralized salt (A) having a molecular weight of 10,000 to 2,000,000 and does not contain a carboxymethylcellulose neutralized salt (B) . Number average obtained by polymerizing a monomer group including styrenes (a1), α, β unsaturated dicarboxylic acids (a2), and polyfunctional vinyl monomers (a3) in toluene as a chain transferable organic solvent A barrier agent for resin-coated paper containing a copolymer neutralized salt (A) having a molecular weight of 10,000 to 2,000,000 and a carboxymethylcellulose neutralized salt (B) in a range of 95: 5 to 70:30 in terms of solid content weight ratio. The barrier agent for resin-coated paper according to claim 1 or 2 , wherein the α, β-unsaturated dicarboxylic acid (a2) is at least one selected from the group consisting of maleic acid, maleic anhydride, and maleic ester. The barrier agent for resin-coated paper according to any one of claims 1 to 3, wherein the polyfunctional vinyl monomer (a3) is a 2- to 4-functional vinyl monomer. The Brookfield viscosity of the copolymer neutralized salt (A) is 1000 to 5000 mPa.s. It is s (10 weight% aqueous solution, 25 degreeC), The barrier agent for resin coated papers in any one of Claims 1-4 characterized by the above-mentioned. The Brookfield viscosity of the neutralized carboxymethyl cellulose salt (B) is 1000 to 20000 mPa.s. It is s (1 weight% aqueous solution, 25 degreeC), The barrier agent for resin coated papers in any one of Claims 1-5 characterized by the above-mentioned. A polyethylene laminate-coated paper comprising the barrier agent for resin-coated paper according to any one of claims 1 to 6 as a barrier layer. Silicone release paper comprising the barrier agent for resin-coated paper according to any one of claims 1 to 7 as a barrier layer.