JPH11247099A - Undercoating agent for release paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an undercoating agent excellent in adhesivity to silicone resins, coatability and in mechanical stability by subjecting an unsaturated monomer to an emulsion polymerization in the presence of a specific water-soluble copolymer as a polymer emulsifier. SOLUTION: This undercoating agent for release paper contains a polymer emulsion obtained by subjecting a hydrophobic nonionic unsaturated monomer such as an alkyl 1-18C (meth)acrylate and a hydrophilic unsaturated monomer to an emulsion polymerization in the presence of a water-soluble copolymer as a polymer emulsifier. The water-soluble copolymer is obtained by copolymerizing 5-60 wt.% of a hydrophobic monomer such as a styrenic compound and/or an alkyl (meth)acrylate, 10-80 wt.% of an anionic unsaturated monomer such as a carboxyl group-containing unsaturated monomer, for example, methacrylic acid, or a sulfonic group-containing unsaturated monomer, for example, styrene sulfonic acid, and 1-50 wt.% of an emulsifier containing a reactive emulsifier as main components, and subsequently neutralizing at least 80% of the anionic groups of the obtained copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an undercoat agent for release paper.

[0002]

2. Description of the Related Art In the production of release paper used in the field relating to adhesives for labels and seals, the mainstream method is to first laminate polyethylene on a base paper and then apply a release solution such as a silicone resin on the base paper. It is. However, due to resource and environmental issues, the need to recycle paper into recycled paper has arisen, and it is desired to convert the polyethylene-based release paper with poor recoverability into easily recoverable release paper. It has become.

As a method for making the release paper easily recoverable, a method of applying an undercoat agent to the base paper instead of laminating polyethylene on the base paper has been proposed. As such an undercoat agent, a water-soluble polymer such as polyvinyl alcohol is widely used. However, since the aqueous solutions of these resins have high viscosities, high-speed coating cannot be performed. Further, the coated surface itself is also inferior in heat shrinkage resistance, and a low concentration coating causes a problem that penetration into the base paper is large and gloss is reduced.

[0004] In recent years, attention has been paid to emulsion-type undercoating agents for these disadvantages. The emulsion type undercoat agent can be applied at a high concentration and a low viscosity, and is extremely excellent in productivity. However, it also has some problems, one of which is that the solvent resistance such as barrier properties is insufficient, so that it is difficult to obtain a stable silicone coating amount and coating film. is there.

[0005]

According to the findings of the present inventors, in particular, when an undercoat layer is formed using a general acrylic copolymer emulsion as an emulsion-type undercoat agent, emulsion synthesis is performed. There is a problem that the low molecular weight emulsifier component used sometimes migrates to the surface of the undercoat layer, and lowers the adhesion to the silicone layer. In addition, in some cases, the silicone resin migrates to the pressure-sensitive adhesive layer under the influence of the decrease in adhesion, which may be one of the causes of a decrease in the adhesive force of the pressure-sensitive adhesive seal.
Furthermore, when an acrylic copolymer emulsion having a composition that satisfies performances such as solvent resistance and adhesion is to be produced at a high concentration, a general low-molecular-weight emulsifier may form aggregates during polymerization. There were also unfavorable points such as occurrence of many occurrences.

The present invention is an undercoat agent having a high solvent resistance required for an undercoat agent for release paper, which has good adhesion to a silicone resin and good stability when synthesizing the undercoat agent. Moreover, an object of the present invention is to provide an undercoat agent for release paper which can be applied at a high concentration and a low viscosity.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, a polymer obtained by polymerizing an unsaturated monomer with a polymer emulsifier having a specific composition shown below. It has been found that an undercoat agent for release paper containing an emulsion can solve all of the above problems. The present invention has been completed based on such new findings.

That is, the present invention provides a water-soluble copolymer containing (A) (1) a hydrophobic unsaturated monomer, (2) an anionic unsaturated monomer, and (3) an emulsifier as main components. And (B) an undercoat agent for release paper containing a polymer emulsion obtained by emulsion polymerization of an unsaturated monomer.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the production of a polymer emulsion used as an undercoat agent for release paper in the present invention, (A) (1) a hydrophobic unsaturated monomer, and (2) an anionic unsaturated monomer. And a water-soluble copolymer obtained by reacting (3) an emulsifier as a main component (hereinafter, referred to as a water-soluble copolymer).
(A) (a water-soluble copolymer) is used as a polymer emulsifier.

(1) As the hydrophobic unsaturated monomer, styrene compounds such as styrene, α-methylstyrene, vinyltoluene and the like; linear or branched α-chain having 6 to 22 carbon atoms;
Olefin; alkyl group having 1 to 18 carbon atoms (meth)
Alkyl acrylate (herein, (meth) acryl means acryl and / or methacryl; hereinafter, the same applies to (meth) acryl); the ester substituent is a 2-hydroxyethyl group , 2
A (meth) acrylic ester having a hydroxyl group in a molecule such as a hydroxyalkyl group such as a hydroxypropyl group; a (meth) acrylic ester having an ester substituent such as a benzyl group or an allyl group; (meth) acrylonitrile;
Vinyl esters such as vinyl acetate and vinyl propionate; and alkyl vinyl ethers having 1 to 22 carbon atoms.

These (1) hydrophobic unsaturated monomers may be used alone or in combination of two or more. Among them, styrene compounds and / or alkyl (meth) acrylates are preferred. Is preferable. In particular, it is preferable to use both a styrene compound and an alkyl (meth) acrylate in terms of excellent viscosity adjustment and mechanical stability of the obtained emulsion. When both are used together, the ratio is based on the weight: styrene compound: alkyl (meth) acrylate = 1:
It is good to be in the range of 2 to 5: 2, preferably 1: 2 to 2: 1.

The alkyl group has 1 to 18 carbon atoms.
The alkyl (meth) acrylate has 1 to 1 carbon atoms
Examples of the alkyl group 18 include straight-chain, branched-chain and cyclic alkyl groups, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl and t-butyl. Group, neopentyl group, n-hexyl group,
Cyclohexyl group, 2-ethylhexyl group, decyl group,
And a palmityl group and a stearyl group. Among these, the case where the alkyl group has 1 to 12 carbon atoms is preferable.

The amount of the (1) hydrophobic unsaturated monomer used is usually 5 to 60% by weight of the water-soluble copolymer (A), preferably 10% by weight at the lower limit and 50% by weight at the upper limit. Preferably, the lower limit is 15% by weight and the upper limit is 40% by weight.
(1) When the amount of the hydrophobic unsaturated monomer used is less than 5% by weight, the particle size of the emulsion obtained is insufficient due to low hydrophobicity and insufficient emulsifiability, resulting in the present invention. The barrier properties of the polymer emulsion tend to decrease.
If it exceeds 60% by weight, the resulting emulsion has insufficient mechanical stability because the hydrophobicity is too strong. When (1) a hydrophobic unsaturated monomer other than a styrene-based compound and / or an alkyl (meth) acrylate is used as the hydrophobic unsaturated monomer, a monomer other than the styrene-based compound or the like is used. The amount of the hydrophobic unsaturated monomer to be used is generally 50% by weight or less, preferably 40% by weight or less, more preferably 20% by weight or less based on the water-soluble copolymer (A).

(2) As the anionic unsaturated monomer,
(Meth) acrylic acid, maleic acid, maleic anhydride, maleic acid half ester, itaconic acid, itaconic acid half ester, citraconic acid, fumaric acid, carboxylic acid group-containing unsaturated monomer such as muconic acid; vinyl sulfonic acid, Sulfonic acid group-containing unsaturated monomers such as styrene sulfonic acid and 2-acrylamido-2-methylpropane sulfonic acid; phosphoric acid group-containing unsaturated monomers such as 2- (meth) acryloyloxyethyl acid phosphate; Alkali metal salts such as sodium salt and potassium salt, alkaline earth metal salts, ammonium salts, salts of organic bases and the like.
Among these anionic unsaturated monomers, as the carboxylic acid group-containing unsaturated monomer, (meth) acrylic acid, maleic acid, maleic anhydride and maleic acid half ester are preferable, and methacrylic acid is particularly preferable. Styrenesulfonic acid is preferred as the sulfonic acid group-containing unsaturated monomer.

The (2) anionic unsaturated monomer may be used alone or in combination of two or more. In the present invention, (A) a water-soluble copolymer is used. In view of the mechanical stability of the resulting emulsion, it is preferable to use the carboxylic acid group-containing unsaturated monomer and the sulfonic acid group-containing unsaturated monomer in combination. The ratio of the carboxylic acid group-containing unsaturated monomer: sulfonic acid group-containing unsaturated monomer = 1: 1 to 6: 1, preferably 3:
It is preferable that the ratio be in the range of 2 to 5: 1.

The amount of the (2) anionic unsaturated monomer used is usually 10 to 80% by weight of (A) the water-soluble copolymer,
Preferably, the lower limit is 20% by weight and the upper limit is 65% by weight, more preferably the lower limit is 30% by weight and the upper limit is 55% by weight. (2) When the amount of the anionic unsaturated monomer used is less than 10% by weight, the hydrophilicity is weak and (A) the viscosity of the water-soluble copolymer increases, and (B) the unsaturated monomer Of the unsaturated monomer (B) tend to form aggregates during the polymerization of the unsaturated monomer, and if it exceeds 80% by weight, the hydrophilicity increases and the emulsifiability is insufficient. The barrier properties of the polymer emulsion of the present invention tend to decrease.

(3) Examples of the emulsifier include anionic emulsifiers such as sodium long-chain α-olefin sulfonate and alkyl diphenyloxyethylene alkyl aryl ether sulfate; polyoxyethylene alkyl ether and polyoxyethylene polyoxypropylene block. Examples include emulsifiers such as polymers, nonionic emulsifiers such as polyoxyethylene alkylphenyl ether, and reactive emulsifiers.

The reactive emulsifier is a surfactant having a hydrophilic group and a hydrophobic group and having a carbon-carbon double bond in the molecule. As the carbon-carbon double bond,
For example, a (meth) allyl group (here, (meth) allyl means allyl and / or methallyl; hereinafter, the same applies to (meth) allyl), 1-propenyl group, 2 Functional groups such as -methyl-1-propenyl group, vinyl group, isopropenyl group and (meth) acryloyl group. Specific examples of the reactive emulsifier include, for example, a polyoxyethylene alkyl ether having at least one functional group in a molecule, a sulfosuccinate salt of a polyoxyethylene alkyl ether having at least one functional group in a molecule, Polyoxyethylene alkyl ether sulfate having at least one functional group in the molecule, polyoxyethylene phenyl ether having at least one functional group in the molecule, polyoxyethylene phenyl ether having at least one functional group in the molecule A sulfosuccinic acid ester salt of oxyethylene phenyl ether, wherein the functional group has at least one
Sulfate salt of polyoxyethylene phenyl ether having at least one functional group in the molecule, polyoxyethylene alkyl phenyl ether having at least one functional group in the molecule, sulfosuccinic acid of polyoxyethylene alkyl phenyl ether having at least one functional group in the molecule Ester salts, sulfate salts of polyoxyethylene alkyl phenyl ether having at least one functional group in the molecule, phosphate salts of polyoxyethylene alkyl phenyl ether having at least one functional group in the molecule, Aliphatic or aromatic carboxylate of polyoxyethylene alkylphenyl ether having at least one group in a molecule, acidic phosphoric acid (meth) acrylate-based emulsifier, rosin glycidyl ester acrylate Things (see JP-A-4-256429), JP 63-23725, JP-Sho 63-2
No. 40931, JP-A-62-104802,
Examples include various emulsifiers described in JP-A-4-50204 and JP-A-4-53802. Further, there can also be mentioned those obtained by replacing polyoxyethylene in the reactive emulsifier with polyoxypropylene or one obtained by block copolymerization or random copolymerization of polyoxyethylene and polyoxypropylene. In the present invention, such a reactive emulsifier can be used without particular limitation.

Commercial products of the above-mentioned (3) reactive emulsifier include, for example, (trade name KAYAMER PM-1, manufactured by Nippon Kayaku Co., Ltd.), (trade name KAYAMER PM-2, manufactured by Nippon Kayaku Co., Ltd.) , (Trade name KAYAMER PM-2
1, Nippon Kayaku Co., Ltd.) (trade name SE-10N, Asahi Denka Kogyo Co., Ltd.), (trade name NE-10, Asahi Denka Kogyo Co., Ltd.), (trade name NE-20, Asahi Denka Kogyo Co., Ltd.
(Product name NE-30, manufactured by Asahi Denka Kogyo Co., Ltd.),
(Trade name New Frontier A229E, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), (trade name New Frontier N-117)
E, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), (trade name: New Frontier N250Z, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), (trade name: Aqualon RN-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), (trade name) Aqualon RN-20, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
(Product name Aqualon RN-50, Daiichi Kogyo Seiyaku Co., Ltd.
(Trade name Aqualon HS-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), (trade name Eminol JS-2, manufactured by Sanyo Chemical Co., Ltd.), (trade name Laterum K-180, Kao Corporation)
And the like.

Among these (3) reactive emulsifiers, in the present invention, the general formula 1:

[0021]

Embedded image

(Wherein R ¹ and R ² are a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, A is a hydrogen atom or a hydrophilic functional group or a salt thereof, and n is an integer of 1 to 200)
It is preferred to use a polyoxyethylene alkylphenyl ether-based reactive emulsifier having an isopropenyl group represented by the following formulas in view of polymerizability and emulsifying property of (A) a water-soluble copolymer. Examples of the hydrocarbon group of R ¹ and R ² include an alkyl group, an alkenyl group, and an aralkenyl group. Examples of the hydrophilic functional group of A include a sulfonic acid group, a phosphoric acid group, a sulfosuccinic acid group, and a sulfosuccinic acid group. Examples thereof include an acid group ester group, and examples of the salt include an alkali metal salt, an alkaline earth metal salt, an ammonium salt, and an organic amine salt. Particularly, A is preferably a hydrogen atom or an ammonium sulfonate group. Commercial products of such a reactive emulsifier include (trade name Aqualon RN-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), (trade name Aqualon RN-20,
(Daiichi Kogyo Seiyaku Co., Ltd.), (trade name: Aqualon RN-5)
0, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

The above (3) emulsifiers can be used alone or in combination of two or more. Further, the water-soluble copolymer (A) which is the polymer emulsifier of the present invention comprises (1)
Since it contains a component obtained by polymerizing a nonionic unsaturated monomer or (2) an anionic unsaturated monomer, it has a lower molecular weight than a case where a polymer emulsion is synthesized using only a normal emulsifier. Although the content is small, (3) the emulsifier further comprises a reactive emulsifier in order to prevent (3) the emulsifier from remaining in a low molecular weight portion in the synthetic polymer protective colloid or polymer emulsion. Preferably, the content of the reactive emulsifier is 100% by weight.
In the case of (1), since a low molecular weight component does not remain, it is more preferable in terms of adhesion between the silicone resin and the undercoat agent.

The amount of the emulsifier (3) used is determined by the emulsifying properties of the polymer emulsifier (A), the water-soluble copolymer, and the emulsifier of the polymer (B). Considering the mechanical stability of the emulsion particles obtained by polymerization, (A) the water-soluble copolymer is usually 1 to 50% by weight, preferably the lower limit is 5% by weight, and the upper limit is 45% by weight, more preferably. The lower limit is 10% by weight and the upper limit is 40% by weight.

In the present invention, if necessary, the above (1) and (2)
And other unsaturated monomers copolymerizable with (3), (A) a water-soluble copolymer without departing from the object of the present invention,
Moreover, it can be used as long as the effect can be maintained. Examples of such unsaturated monomers include vinylpyrrolidone, acrylamide, N, N-dimethylacrylamide and the like. Its usage is
The aqueous solution of the obtained copolymer is in a range that does not deteriorate the coating film performance, and it can be used in combination usually at 30% by weight or less, preferably 20% by weight or less of the water-soluble copolymer (A).

The process for producing the water-soluble copolymer (A) of the present invention may be carried out by a known means, for example, a mixture of the above-mentioned predetermined amount of a monomer such as (1), (2) or (3). And a method in which polymerization is carried out by dropping a polymerization initiator solution, and a method in which polymerization is carried out by divided charging or simultaneous charging. The polymerization temperature is usually about 40 to 150 ° C., and the reaction time is about 2 to 12 hours. Water as the polymerization solvent,
A mixed solution of an organic solvent and water / organic solvent can be used. When an organic solvent is used, the organic solvent is distilled off by steam distillation or vacuum distillation, and then dissolved in water to form an aqueous solution.

The organic solvent used as the polymerization solvent includes alcohols such as ethyl alcohol and propyl alcohol, aromatic hydrocarbons such as benzene and toluene, lower ketones such as acetone and methyl ethyl ketone, ethyl acetate, chloroform, dimethylformamide and the like. Can be used alone or in appropriate combination, and if it is a water-soluble solvent, it can be used in combination with water.

There are no particular restrictions on the type of polymerization initiator, and inorganic peroxides such as hydrogen peroxide, ammonium persulfate and potassium persulfate, and organic peroxides such as benzoyl peroxide, dicumyl peroxide and lauryl peroxide. And azo compounds such as 2,2′-azobisisobutyronitrile and dimethyl-2,2′-azobisisobutyrate. The used amount is usually about 0.01 to 5 parts by weight based on 100 parts by weight of the unsaturated monomer mixture. In addition,
In the case of a radical polymerization initiator, the reaction system may be a redox system using a reducing agent such as sodium hydrogen sulfite and sodium thiosulfate, and dodecyl mercaptan in order to adjust the degree of polymerization during polymerization to obtain a desired viscosity. 2-
Chain transfer agents such as mercaptobenzothiazole, bromotrichloromethane, alpha-methylstyrene dimer and the like can also be used.

Further, the water-soluble copolymer (A) of the present invention comprises:
In order to be solubilized in water, it is preferable that at least 80%, more preferably, the anionic unsaturated monomer is completely neutralized to form a salt. The adjustment of the neutralization ratio can be carried out in advance at the stage of (2) the anionic unsaturated monomer, and can also be carried out after the polymerization of the water-soluble copolymer (A). Examples of the neutralized salt include an ammonium salt, a volatile amine salt, an alkali metal salt and the like.

As the ammonium salt, ammonium salts such as ammonium carbonate and the like can be used in addition to ammonia. Examples of the volatile amine salts include aliphatic, alicyclic or aromatic amine salts having 1 to 12 carbon atoms, similar arylamine salts, alkanolamine salts and the like. Specific examples of the volatile amine include, for example, aliphatic amines such as monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine and monobutylamine, alicyclic amines such as cyclohexylamine, aromatic amines such as aniline, and arylamines And primary and secondary amines such as alkanolamine. In addition, sodium hydroxide, potassium hydroxide and the like can be mentioned as those forming an alkali metal salt.

The weight-average molecular weight of the water-soluble copolymer (A) is usually 1,000 to 1,000,000, preferably the lower limit is 5,000, and the upper limit is 500,000. When the weight average molecular weight is less than 1,000, the obtained polymer emulsion has insufficient barrier properties and mechanical stability. Also,
When the weight average molecule exceeds 1,000,000, (B)
The emulsifying properties of the unsaturated monomer are not sufficient, and aggregates tend to be generated during the polymerization of the unsaturated monomer (B). In addition,
(A) The water-soluble copolymer usually has a viscosity of 10 to 4000 cps (25 ° C.) at a concentration of 20% by weight.

The polymer emulsion used as a main component of the undercoat agent for release paper of the present invention is the above-mentioned (A)
It is obtained by emulsion polymerization of the unsaturated monomer (B) in an aqueous solution containing a water-soluble copolymer.

As the unsaturated monomer (B), nonionic unsaturated monomers, anionic unsaturated monomers, cationic unsaturated monomers and the like can be used. In particular, in the present invention, it is preferable that the unsaturated monomer (B) contains a nonionic unsaturated monomer, and more preferably that the hydrophobic monomer contains a hydrophobic nonionic unsaturated monomer. More preferably, it contains a hydrophobic nonionic unsaturated monomer and a hydrophilic unsaturated monomer.

Nonionic unsaturated monomers include styrene compounds such as styrene, α-methylstyrene and vinyltoluene; linear or branched α-olefins having 6 to 22 carbon atoms; methyl (meth) acrylate Alkyl (meth) acrylate having 1 to 18 carbon atoms in the alkyl group, such as ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, and stearyl (meth) acrylate Esters; (meth) acrylates having a hydroxyl group in the molecule; (meth) acrylates in which the ester substituent is a benzyl group, an allyl group, or the like;
(Meth) acrylamide; (meth) acrylonitrile;
Vinyl esters such as vinyl acetate and vinyl propionate; alkyl vinyl ethers having 1 to 22 carbon atoms such as methyl vinyl ether; epoxy group-containing (meth) acrylates such as glycidyl (meth) acrylate; N-methylol (meth) acrylamide N-substitution of (meta)
Various known compounds such as acrylamides, urethane acrylates, and diphenyl-2 (meth) acryloyloxyphosphate are exemplified.

In the present invention, it is preferable to use a hydrophobic nonionic unsaturated monomer as the nonionic unsaturated monomer. Specifically, (A) in the water-soluble copolymer (A) The compounds exemplified as the hydrophobic unsaturated monomer are exemplified. Among such hydrophobic nonionic unsaturated monomers, alkyl (meth) acrylates having 1 to 18 carbon atoms in the alkyl group, (meth) acrylonitrile, styrene compounds and the like are preferable, and alkyl is particularly preferable. It is an alkyl (meth) acrylate having 1 to 18 carbon atoms and / or (meth) acrylonitrile. In addition, among the alkyl (meth) acrylates having 1 to 18 carbon atoms in the alkyl group, particularly, the alkyl (meth) acrylate having 1 to 8 carbon atoms in the alkyl group, and further, the (meth) acrylate having 4 to 8 carbon atoms ) Acrylic acid alkyl esters are preferred because they can greatly impart flexibility and film forming properties to the undercoat agent for release paper, and can greatly improve the yield of silicone on the paper surface. Examples of the alkyl (meth) acrylate having 4 to 8 carbon atoms in the alkyl group include n-butyl (meth) acrylate and (meth) acrylate.
Iso-butyl acrylate, 2-ethylhexyl (meth) acrylate and the like. Further, an alkyl (meth) acrylate having 1 to 3 carbon atoms in the alkyl group or a styrene-based compound can provide favorable effects on the viscosity, glass transition temperature, and coatability of the obtained polymer emulsion.

In the present invention, as the hydrophobic nonionic unsaturated monomer, in addition to those exemplified above,
Further, the inclusion of a (meth) acrylic acid ester having a hydroxyl group in the molecule improves the water dispersibility during polymerization by introducing a hydrophilic group into the obtained polymer emulsion. This is preferable in that adhesion can be improved by bonding. Having a hydroxyl group in the molecule (meth)
Examples of the acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, and 2-hydroxy-3-phenoxypropyl ( (Meth) acrylate, glycerol mono (meth) acrylate and the like.

Further, in the present invention, in addition to the above-mentioned hydrophobic nonionic unsaturated monomer, a hydrophilic unsaturated monomer is contained, so that the solvent resistance of the undercoat film such as a barrier property can be improved. It is preferred in that respect. Such unsaturated monomers include, for example, hydrophilic nonionic unsaturated monomers and / or
Or an anionic unsaturated monomer.

A preferred example of the hydrophilic nonionic unsaturated monomer is acrylamide. Further, as the anionic unsaturated monomer, the monomers and salts thereof exemplified in (2) the anionic unsaturated monomer which is a component of the water-soluble copolymer (A) can be used. Of these, (meth) acrylic acid is preferred.

The various monomers exemplified as the unsaturated monomer (B) in the present invention can be used alone or in combination of two or more.

The amount of various monomers used in the unsaturated monomer (B) is appropriately determined in consideration of the performance of the obtained polymer emulsion as an undercoat agent for release paper. Preferably, in the unsaturated monomer (B), the hydrophobic nonionic unsaturated monomer is 50 to 100% by weight, more preferably the lower limit is 60% by weight and the upper limit is 90% by weight,
The content of the hydrophilic unsaturated monomer is 0 to 50% by weight, more preferably the lower limit is 10% by weight and the upper limit is 40% by weight. When the (meth) acrylic acid ester having a hydroxyl group in the molecule (hereinafter referred to as (B1) as necessary) is preferably used as the hydrophobic nonionic unsaturated monomer, (B) ) 0-40% by weight of the unsaturated monomer, more preferably 5% by weight as the lower limit and 30% by weight as the upper limit
It is. In this case, also in this case, the hydrophobic nonionic unsaturated monomer other than the (meth) acrylic acid ester having a hydroxyl group in the molecule (hereinafter referred to as (B2) as necessary) is represented by (B) unsaturated monomer. Preferably, it is 20% by weight.
When various components are used in this range, production at a high concentration, stability of the obtained polymer emulsion, coating suitability,
It is preferable in terms of balance such as barrier properties. (B1)
If it exceeds 40% by weight in the unsaturated monomer (B), the stability of the resulting polymer emulsion tends to decrease. Further, when (B2) is less than 20% by weight in the unsaturated monomer (B), or when the hydrophilic unsaturated monomer is (B)
When the content exceeds 50% by weight in the unsaturated monomer, the glass transition temperature of the obtained polymer emulsion becomes high, so that the film forming property and the flexibility of the coating film when the undercoat agent of the present invention is applied are increased. Thus, fine coating irregularities such as pinholes are likely to be generated in the coating film, and the barrier properties of this portion tend to be reduced. When the amount of the anionic unsaturated monomer, which is a hydrophilic unsaturated monomer, exceeds 50% by weight of the unsaturated monomer (B), the undercoat agent of the present invention may be applied to clay or the like. Since the stability at the time of mixing when used in combination with the pigment of the formula (1) tends to decrease, especially when used in combination with clay, the hydrophilic unsaturated monomer may be an anionic unsaturated monomer. It is preferable to suppress the use of the monomer and to use the hydrophilic nonionic unsaturated monomer in view of the stability at the time of mixing the undercoat agent of the present invention with the clay.

As the unsaturated monomer (B), as long as the stability of the polymer emulsion of the present invention is not impaired,
Cationic unsaturated monomers can also be used.

Further, in addition to (B) the unsaturated monomer described above, (a) a monomer having one (meth) allyl group as a carbon-carbon double bond and / or
Or (b) general formula 2: CH ₂ ＣC (R ³ ) -CONR
⁴ (R ⁵ ) (wherein, R ³ is a hydrogen atom or a methyl group;
⁴ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and R ⁵ is a linear or branched alkyl group having 1 to 4 carbon atoms). Acrylamides may be contained. When component (a) and / or component (b) is contained, the viscosity can be reduced by introducing a branched structure as a chain transfer agent, and as a result, high concentration can be achieved, and coating suitability and barrier property can be improved. The performance is improved. In addition, by reducing the viscosity of the polymer emulsion, miscibility with clay can be improved.

(A) As a carbon-carbon double bond, (meth)
A monomer having one allyl group is defined as (meth)
A monomer having only one allyl group and having no carbon-carbon double bond other than the (meth) allyl group. In addition, when there are two or more (meth) allyl groups in the molecule, it is not preferable because gelation occurs and the molecular weight distribution becomes wide. The same applies to a case having another carbon-carbon double bond different from a (meth) allyl group, for example, an acryloyl group. Examples of such a monomer having one (meth) allyl group as a (A) carbon-carbon double bond include:
At least one selected from (meth) allylsulfonic acid, (meth) allylcarboxylic acid and salts thereof and (meth) allyl alcohol can be used. These (A)
Among the components, (meth) allyl sulfonic acid or a salt thereof is preferable in that the obtained polymer emulsion has a high concentration and a low viscosity, and methallyl sulfonic acid or a salt thereof is more preferable in terms of monomer stability. Examples of the salt include an alkali metal salt such as a sodium salt and a potassium salt, an ammonium salt, and the like.

(B) General formula 2: CH ₂ ＣC (R ³ ) -C
ONR ⁴ (R ⁵ ) (wherein, R ³ is a hydrogen atom or a methyl group, R ⁴ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and R ⁵ is a straight chain having 1 to 4 carbon atoms. A linear or branched alkyl group having 1 to 4 carbon atoms for R4 or R5 in the N-substituted (meth) acrylamides represented by a chain or a branched chain alkyl group) Examples include an ethyl group, an isopropyl group and a t-butyl group. Specific examples of the component (b) include N,
N-dimethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide and Nt-butyl (meth) acrylamide And at least one selected from these can be used. Among these components (b), dimethylacrylamide is preferred in terms of copolymerizability and chain transfer.

The components (a) and (b) both attempt to introduce many branched structures into the obtained polymer emulsion by utilizing the chain transfer properties of the components. By using this technique, a branched polymer without gelation can be obtained, and a high-concentration and low-viscosity polymer emulsion can be obtained. Even if a generally known chain transfer agent such as isopropyl alcohol is used in place of the components (a) and (b), a polymer emulsion having a reduced viscosity cannot be obtained. When a crosslinkable vinyl monomer (having at least two double bonds) is used, the polymer emulsion is apt to gel, and it is difficult to produce it at a high concentration.

The amount of component (a) and / or component (b) used is determined in consideration of the performance of the obtained polymer emulsion as an undercoat agent for release paper.
Usually, 0.01 to 100 parts by weight of the (B) unsaturated monomer other than the component (a) and / or the component (b) is used.
It is about 10 parts by weight. The upper limit of the amount of component (a) and / or component (b) used is preferably 5 parts by weight, more preferably 3 parts by weight. The lower limit is preferably 0.05 parts by weight, more preferably 0.1 part by weight.
Parts by weight. When the components (a) and (b) are used together, the total weight is within the above range. (A)
The amount of the component and / or the component (b) used is (B) the unsaturated monomer 1 other than the component (a) and / or the component (b).
If it exceeds about 10 parts by weight with respect to 00 parts by weight, it is difficult to obtain sufficient barrier properties as an undercoat agent for release paper, and it is difficult to obtain a stable polymer emulsion when mixed with clay or the like.

In the present invention, the amounts of (A) the water-soluble copolymer and (B) the unsaturated monomer used are determined in consideration of the performance of the obtained polymer emulsion as an undercoat agent for release paper. decide. Usually, in the total amount of the water-soluble copolymer (A) and the unsaturated monomer (B) used, (A)
The water-soluble copolymer is 0.1 to 10 parts by weight, and the (B) unsaturated monomer is 99.9 to 90 parts by weight.
The lower limit of (A) the water-soluble copolymer is 0.5 parts by weight, the upper limit is 5 parts by weight, and the lower limit of (B) the unsaturated monomer is 95 parts by weight and the upper limit is 99.5 parts by weight. is there.
(A) When the amount of the water-soluble copolymer is less than 0.1 part by weight, a stable emulsion cannot be selected. When the amount exceeds 10 parts by weight, it is difficult to obtain a sufficient barrier property as an undercoat agent for release paper.

The polymer emulsion of the present invention can be obtained by emulsion polymerization of the unsaturated monomer (B) using the water-soluble copolymer (A) as a polymer emulsifier by a known emulsion polymerization method. For example, a method in which water and (A) a water-soluble copolymer are charged into a predetermined reaction vessel, and then (B) an unsaturated monomer is charged and stirred, a radical polymerization initiator is added, and the mixture is heated with stirring. Can be performed.
As another method, for example, water is charged into a predetermined reaction vessel, heated to a predetermined temperature, and then an aqueous solution of (A) a water-soluble copolymer, (B) an unsaturated monomer, and a radical polymerization initiator is prepared. And a continuous dropping method is required. The method of dropping (B) the unsaturated monomer or the radical polymerizable initiator may be any of batch dropping and divided dropping.

In consideration of the stability at the time of the emulsion polymerization, if necessary, the water-soluble copolymer (A), which is a polymer emulsifier,
For example, anionic surfactants such as oleate, laurylate, alkylbenzene sulfonate, dialkyl sulfosuccinate, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl ether, polyoxyethylene phenyl ether, polyoxyethylene alkyl A nonionic surfactant such as allyl ether can also be used in combination. At this time, care should be taken to keep the amount used to a very small amount in order not to cause deterioration with time of the adhesion to the silicone. Further, a relatively low-molecular polymer compound having emulsifying and dispersing ability, for example, polyvinyl alcohol,
And a modified product thereof, polyacrylamide, a polyethylene glycol derivative, a neutralized product of a polycarboxylic acid copolymer,
Casein or the like can be used alone or in combination with the above emulsifier.

Examples of the radical polymerization initiator include a persulfate such as potassium persulfate and ammonium persulfate; a water-soluble radical polymerization initiator such as hydrogen peroxide and an aqueous azo initiator; Redox polymerization initiators in the form of a combination with a reducing agent such as sodium hydrogen sulfite, sodium thiosulfate and the like can be mentioned. The amount of the initiator used is not particularly limited, but is usually about 0.5 to 5 parts by weight based on 100 parts by weight of the monomer mixture. In addition,
In the present invention, a chain transfer agent can be used as needed at the time of polymerization. Examples of the chain transfer agent include those exemplified in the method for producing the water-soluble copolymer (A).

The solid content of the reaction system is usually about 20 to 70% by weight. If the viscosity is low, the solid content concentration is usually preferably higher. In addition, the pH at the time of polymerization is usually preferably in the range of about 2 to 9. The reaction temperature may be within a temperature range for activating the radical polymerization initiator, and is usually 40 to 9
The lower limit is about 60 ° C. or more, and the upper limit is more preferably 90 ° C. or less. Reaction time is usually 30 minutes or more.
It is about 4 hours.

The undercoat agent for release paper of the present invention containing such a polymer emulsion can be used as an undercoat agent for release paper as it is, or can be used by mixing with a pigment such as clay. You can also. Although the mixing ratio with the pigment is not particularly limited, the pigment can be mixed in a solid content ratio of 1000 parts by weight or less with respect to 100 parts by weight of the polymer emulsion. As such pigments, those in which polyvinyl alcohol, starch and the like are blended in advance can also be used.

When the undercoat agent for release paper of the present invention is applied to a backing paper, a crosslinking agent such as glyoxal or a water-soluble zirconium compound is used in combination to improve the adhesion to the silicone resin at high temperature and high humidity. It can be further improved. As a method of applying the undercoat agent for release paper, a wire bar, a blade coater,
An air knife coater, a roll coater or the like can be used, and a known drying device such as an oven or a drum dryer can be used for drying. Furthermore, the film may be subjected to a calendering treatment to prepare a desired smoothness.

[0054]

The undercoat agent for release paper containing the polymer emulsion of the present invention is suitable for easily recoverable release paper, and uses a high molecular weight emulsifier. Its presence is suppressed, so that the adhesiveness with the silicone resin is good over time, and the coating properties and mechanical stability are also excellent. Furthermore, when a reactive emulsifier is used in the polymer emulsifier, components such as a low molecular weight emulsifier do not remain, so that the adhesion to the silicone resin is good over time. The use of a reactive emulsifier in the polymer emulsifier is particularly effective, but the polymer emulsion in the undercoat agent for release paper of the present invention has a low viscosity. Therefore, the undercoat agent for release paper of the present invention can be applied at a high concentration, so that even when various solvent-type or solventless-type silicone resins are applied to the base paper, the paper layer and the undercoat layer are formed. Solvent and silicone resin do not penetrate into it, and the undercoat agent for release paper composed of the polymer emulsion of the present invention has a low viscosity despite its high concentration, so a high coating amount is possible. Excellent operability.

Further, in the monomer mixture, (a) a monomer having one (meth) allyl group as a carbon-carbon double bond and / or (b) a general formula 2: CH ₂ ＣC (R
³ ) —CONR ⁴ (R ⁵ ) (wherein, R ³ is a hydrogen atom or a methyl group, R ⁴ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and R ⁵ is a 1 to 4 carbon atom) 4 represents a straight-chain or branched-chain alkyl group), the chain transfer reaction and the formation of a branched structure can be promoted, and the resulting polymer emulsion is obtained. Can be mixed at a high concentration even with clay, for example, and can impart solvent resistance and flexibility to the clay coat layer.

[0056]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Reference Examples, Examples, and Comparative Examples, but the present invention is not limited to these Examples. In each example, unless otherwise specified, parts are by weight.

Reference Example 1 (Production of (A) water-soluble copolymer) Into a reactor equipped with a stirrer, a reflux condenser, and a nitrogen inlet tube, 300 parts of water was added while introducing nitrogen, and the mixture was heated with stirring. The temperature was raised to 80C. 15 parts of styrene,
15 parts of methyl methacrylate, 30 parts of methacrylic acid, 15 parts of sodium styrenesulfonate, and a polyoxyethylene alkyl phenyl ether-based reactive emulsifier (trade name: Aqualon RN-20, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) And a polymerization initiator solution obtained by dissolving 3 parts of potassium persulfate in 60 parts of water was added dropwise over 3 hours, followed by aging for 2 hours. To complete the reaction. After cooling 4
29 parts of an 8% aqueous sodium hydroxide solution (100 mol% neutralized with respect to methacrylic acid) was added, diluted with water and adjusted so that the solid content of the copolymer became 20%, and the viscosity at 25 ° C. was 25 cps. (BM type viscometer, 60 rpm, 60 ° C.) to obtain an aqueous solution of the water-soluble copolymer (A1).

Reference Examples 2 to 9 ((A) Production of Water-Soluble Copolymer) In Reference Example 1, except that the kind of monomer, composition ratio and neutralization ratio were changed as shown in Table 1, An aqueous solution of a water-soluble copolymer (A2 to A9 in order) was obtained in the same manner as in Example 1. Table 1 shows the properties of the aqueous solution of the obtained water-soluble copolymer.

[0059]

[Table 1]

In Table 1, ST is styrene, MMA is methyl methacrylate, nBA is n-butyl acrylate, AA is acrylic acid, MAA is methacrylic acid, NaSS is sodium styrene sulfonate, and RN-20 is a reactive emulsifier ( Trade name Aqualon RN-10, Daiichi Kogyo Seiyaku Co., Ltd.
HS-20 is a reactive emulsifier (trade name: Aqualon H)
S-20, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and ES-70 represent an alkylphenyl ether sulfate-type emulsifier (trade name: Eleminol ES-70, manufactured by Sanyo Chemical Co., Ltd.) which is not a reactive emulsifier.

Example 1 In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen gas inlet tube, a monomer dropping funnel and a thermometer, 67 parts of water and 7.5 parts of an aqueous solution of a water-soluble copolymer (A1) (solid content As 1.5
Parts) and heated at 70 ° C. under a nitrogen stream, and an aqueous initiator solution consisting of 1 part of ammonium persulfate and 3 parts of water was added at 70 ° C. Subsequently, polymerization was started while dropwise adding a monomer mixture composed of 29 parts of methacrylic acid, 38 parts of n-butyl acrylate, 30 parts of methyl methacrylate, and 3 parts of acrylonitrile, and an aqueous initiator solution composed of 1 part of ammonium persulfate and 17 parts of water. . After the reaction was carried out for 60 minutes so that the polymerization temperature did not exceed 80 ° C., the mixture was neutralized with sodium hydroxide to obtain a target polymer emulsion. The solid concentration of the obtained polymer emulsion was 50% by weight, pH 7.1, 2
The viscosity at 5 ° C. was 900 cps.

Examples 2 to 4, 10 to 12, 16 and 1
7 Polymerization was carried out in the same manner as in Example 1 except that the type, amount and solid content of each of the monomer mixture of component (B) and the emulsifier were changed as shown in Table 2, and various polymerizations were carried out. A combined emulsion was obtained. Tables 2 to 4 show the properties of the obtained polymer emulsion.

Example 5 55 parts of water was charged into a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen gas inlet tube, a monomer dropping funnel and a thermometer, and the temperature was raised under a nitrogen stream.
Aqueous initiator solution consisting of 3 parts water and 3 parts water. Subsequently, 29 parts of acrylamide, 38 parts of n-butyl acrylate,
30 parts of methyl methacrylate, 3 parts of acrylonitrile, 12 parts of water, and an aqueous solution 7.5 of the water-soluble copolymer (A1)
The polymerization was started while dropwise adding a monomer mixed aqueous solution consisting of 1 part (1.5 parts as solid content) and an initiator aqueous solution consisting of 1 part of ammonium persulfate and 17 parts of water. After reacting for 60 minutes so that the polymerization temperature does not exceed 80 ° C,
Neutralized with sodium hydroxide to obtain the desired polymer emulsion. The nonvolatile content of the obtained polymer emulsion is 50
Weight%, pH 7.1, viscosity at 25 ° C. 980 cps
Met.

Examples 6 to 9, 13 to 15, 18 to 20 In Example 5, the type, amount and solid content of each of the component (B) monomer mixture and emulsifier were changed as shown in Table 2. Otherwise, polymerization was carried out in the same manner as in Example 5 to obtain various polymer emulsions. Tables 2 to 4 show the properties of the obtained polymer emulsion.

Comparative Example 1 In Example 1, an alkylphenyl ether sulfate emulsifier (P) was used in place of the water-soluble copolymer (A1).
1) (Trade name Eleminor ES-70, Sanyo Chemical Co., Ltd.)
Polymerization was carried out in the same manner as in Example 1 except that the amount was changed to 5 parts (solid content: 4 parts) to obtain various polymer emulsions.
Table 4 shows the properties of the obtained polymer emulsion.

Comparative Example 2 In Example 2, an alkylphenyl ether sulfate type emulsifier (P) was used in place of the water-soluble copolymer (A1).
1) (Trade name Eleminor ES-70, Sanyo Chemical Co., Ltd.)
Polymerization was carried out in the same manner as in Example 2 except that the amount was changed to 5 parts (4 parts as solid content) to obtain various polymer emulsions.
Table 4 shows the properties of the obtained polymer emulsion.

Comparative Example 3 In Example 5, an alkylphenyl ether sulfate type emulsifier (P) was used in place of the water-soluble copolymer (A1).
1) (Trade name Eleminor ES-70, Sanyo Chemical Co., Ltd.)
Polymerization was carried out in the same manner as in Example 5 except that the amount was changed to 5 parts (4 parts as solid content) to obtain various polymer emulsions.
Table 4 shows the properties of the obtained polymer emulsion.

Comparative Example 4 In Example 6, an alkylphenyl ether sulfate type emulsifier (P) was used in place of the water-soluble copolymer (A1).
1) (Trade name Eleminor ES-70, Sanyo Chemical Co., Ltd.)
Polymerization was carried out in the same manner as in Example 6 except that the amount was changed to 5 parts (4 parts as solid content) to obtain various polymer emulsions.
Table 4 shows the properties of the obtained polymer emulsion.

In Comparative Examples 1 to 4, a large amount of aggregates was observed during the polymerization of the polymer emulsion.

[0070]

[Table 2]

[0071]

[Table 3]

[0072]

[Table 4]

In Tables 2 to 4, 2HEMA is 2-HEMA.
Hydroxyethyl methacrylate, nBA is n-butyl acrylate, MMA is methyl methacrylate, AN is acrylonitrile, AM is acrylamide, MAA is methacrylic acid, SMAS is sodium methallyl sulfonate, SAS
Represents sodium allyl sulfonate, DMAA represents N, N-dimethylacrylamide, and IPAA represents N-isopropylacrylamide. Further, the water-soluble copolymers (A1) to (A
In the description of the amount used in 9), 7.5 parts is 1.5 parts by solid content, and 5 parts is 1 part by solid content.

(Preparation of Sample 1: Clear Coated Paper) A coating solution was prepared by diluting the polymer emulsions obtained in Examples 1 to 20 and Comparative Examples 1 to 4 to 20% by weight, and then solids were adhered. Coating and drying were performed on PPC paper so that the amount was 2-3 g / m2. Using this as a sample, a performance test was performed according to the following method. The results are shown in Tables 5 to 7.

(Preparation of Sample 2: Clay Coated Paper) Example 1
The polymer emulsions obtained in Comparative Examples 1 to 4 and Comparative Examples 1 to 4 and a clay aqueous solution having a concentration of 75% by weight were mixed so that the respective solid content weight ratios were 1: 1. After adding water so that the content was 50% by weight, the mixture was stirred at a high speed with a homodisper and mixed to prepare a coating liquid. This is added to PP so that the solid content is 6 g / m ^2.
Coating and drying were performed on C paper. Using this as a sample, a performance test was performed according to the following method. The results are shown in Table 5
FIG.

(Solvent resistance) Dye (Sudan II)
A toluene solution containing 1% by weight was applied so as to have a concentration of 12 g / m ^2, and after 5 seconds, it was wiped off with a gauze, and the coated surface was visually observed according to the following criteria. Sex "was evaluated.

"Toluene oil repellency" A: Almost no dyeing. Δ: Stained with dye but no strikethrough. ×: Complete strikethrough. When the polymer emulsion has excellent oil repellency, the dye does not easily penetrate into the coating film of the undercoat agent containing the polymer emulsion, so that the coating surface is hardly stained. Therefore, the oil repellency of the undercoat agent itself containing the polymer emulsion can be determined by the degree of dyeing of the coating surface of the polymer emulsion. In addition, the degree of the dyeing is also effective as a criterion for determining the degree of yield on the surface of the undercoat layer when the solvent silicone is applied, and the uniformity and smoothness of the formed silicone layer.

"Toluene barrier property" ：: No strikethrough occurs and no pinholes are generated. Δ: Pinholes are generated. ×: Complete strikethrough. In addition, even if the coating film itself evaluated by the toluene oil repellency has oil repellency, if the film forming property of the undercoat agent is inferior, some places where the barrier property of toluene is inferior occur, and the dye Seeps like a hall. The less underpinning occurs, the more uniform the undercoat layer is formed. The presence or absence of pinholes is also effective as a criterion for determining the uniformity, smoothness, etc. of the silicone layer formed when the solvent silicone is applied.

(Silicone Adhesion) A curing catalyst (trade name Silcole) was added to 100 g of solvent silicone (trade name: Silicone Lease KF-100, manufactured by Arakawa Chemical Industry Co., Ltd.).
ase90B, manufactured by Rhone Poulin Co.)
A solution prepared with toluene at a concentration of 7% by weight was applied to the sample so that the solid content was 1 g / m ^2, and then dried and cured at 130 ° C. for 20 seconds. Then, 20
After leaving for 1 day (condition 1) at 65 ° C. and 65% humidity, 7 days (condition 2) under the same conditions and 7 days at 50 ° C. and 90% humidity (condition 3), the coated surface was rubbed with a finger. The silicone peeling state was evaluated according to the following criteria. ：: Does not peel. Δ: Slightly peeled off. ×: Complete peeling.

(Clay Mixability) The state of the coating liquid prepared by the above method was evaluated according to the following criteria. ：: uniformly dispersed. The viscosity is also stable. Δ: Aggregates are slightly generated. It is slightly thicker. ×: Completely agglomerated.

(Coating Suitability) The clay coating solution prepared by the above method was applied to a Meyer bar coating machine PI-1210F.
The condition at the time of coating with ILMCOATER (manufactured by Tester Sangyo Co., Ltd.) was evaluated according to the following criteria. ：: The bar proceeds smoothly, and a uniform and smooth coated surface is formed. Δ: The bar was slightly caught and it was difficult to obtain a smooth surface. ×: The bar was completely caught and coating was extremely difficult or impossible.

[0082]

[Table 5]

[0083]

[Table 6]

[0084]

[Table 7]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08F 220/54 C08F 220/54 C09D 157/06 C09D 157/06

Claims (13)

[Claims] (A) (1) a hydrophobic unsaturated monomer,
A polymer obtained by emulsion-polymerizing (B) an unsaturated monomer using (2) an anionic unsaturated monomer and (3) a water-soluble copolymer containing an emulsifier as a main component as a polymer emulsifier. An undercoat agent for release paper containing a coalesced emulsion. 2. A method according to claim 1, wherein (A) the water-soluble copolymer comprises (1) 5 to 60% by weight of a hydrophobic unsaturated monomer, (2) 10 to 80% by weight of an anionic unsaturated monomer, and (3) ) Emulsifiers 1-50
2. A copolymer containing 1% by weight as a main component.
The undercoat agent for release paper according to the above. 3. The undercoat agent for release paper according to claim 1, wherein (1) the hydrophobic unsaturated monomer contains a styrene compound and / or an alkyl (meth) acrylate. (2) As the anionic unsaturated monomer,
The undercoat agent for release paper according to any one of claims 1 to 3, comprising a carboxylic acid group-containing unsaturated monomer and a sulfonic acid group-containing unsaturated monomer. 5. The undercoat agent for release paper according to claim 1, wherein (3) the emulsifier contains a reactive emulsifier. 6. The reactive emulsifier represented by the general formula 1: (Wherein, R ¹ and R ² represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, A represents a hydrogen atom or a hydrophilic functional group or a salt thereof, and n represents an integer of 1 to 200). The undercoat agent for a release paper according to claim 5, which is a compound having a low viscosity. 7. The method according to claim 1, wherein (A) at least 80% of the anionic groups of the water-soluble copolymer are neutralized to form a salt.
7. The undercoat agent for release paper according to any one of items 6 to 6. 8. The release according to claim 1, wherein (B) the unsaturated monomer comprises a hydrophobic nonionic unsaturated monomer and a hydrophilic unsaturated monomer. Undercoat agent for paper. 9. The release paper according to claim 8, wherein the hydrophobic nonionic unsaturated monomer is an alkyl (meth) acrylate having 1 to 18 carbon atoms in the alkyl group and / or (meth) acrylonitrile. Undercoat agent. 10. The undercoat agent for release paper according to claim 9, further comprising a (meth) acrylic acid ester having a hydroxyl group in the molecule as the hydrophobic nonionic unsaturated monomer. 11. The release paper according to claim 8, wherein the hydrophilic unsaturated monomer is a hydrophilic nonionic unsaturated monomer and / or an anionic unsaturated monomer. Undercoat agent. 12. A monomer having (B) an unsaturated monomer and further (a) a monomer having one (meth) allyl group as a carbon-carbon double bond and / or (b) a compound represented by the general formula 2: CH
₂ ＣC (R ³ ) -CONR ⁴ (R ⁵ ) (where R ³ is a hydrogen atom or a methyl group, R ⁴ is a hydrogen atom or a carbon atom
A linear or branched alkyl group having 1 to 4 carbon atoms, and R ⁵ represents a linear or branched alkyl group having 1 to 4 carbon atoms). Item 12. An undercoat agent for release paper according to any one of Items 1 to 11. 13. The amount of the water-soluble copolymer (A) used is 0.1.
1 to 10 parts by weight, the amount of the unsaturated monomer (B) used is 99.
The undercoat agent for release paper according to any one of claims 1 to 12, which is 9 to 90 parts by weight.