JP2006291040A - Aqueous adhesive composition for wet laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous adhesive composition for wet laminate, relating mainly with the wet lamination such as adhesion or the like between paper and aluminum foil, which is excellent in environmental fitness and workability, and which can improve water resistance, heat resistance, freezing resistance, cold resistance, oil resistance and corrosion resistance of a laminate article. <P>SOLUTION: The aqueous adhesive composition for wet laminate comprises the resin composition obtained by carrying out the emulsion polymerization of an unsaturated monomer mixture comprising: a polymerizable unsaturated monomer (a) containing 0.1-5 wt.% hydrolyzable silyl group; a polymerizable unsaturated monomer (b) comtaining 0.1-10 wt.% acid group; a polymerizable unsaturated monomer (c) containing 0.1-10 wt.% epoxy group; and 75-99.7 wt.% other polymerizable unsaturated monomer (d). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a water-based adhesive composition useful mainly for various wet laminations, such as adhesion between paper and aluminum foil, and more specifically, as an adhesive for wet bonding of paper and aluminum foil, to environmental suitability. The present invention relates to a water-based adhesive composition for wet laminating that is excellent and can improve workability, adhesion, water resistance, heat resistance, refrigeration resistance, cold resistance, oil resistance, corrosion resistance and the like of a laminate.

  Aluminum foil has better gas barrier properties, moisture resistance, light-shielding properties, heat resistance, and cold resistance than plastic films, etc., and has excellent metal-specific extensibility and can be made thin, but it can be folded, torn, or scratched. It is easily scratched and rarely used alone. For this reason, it is used by strengthening it by bonding with paper, cellophane, plastic film, and the like. Among them, there are many laminations with paperboard and imitation paper, and they have been used for lunch boxes, confectionery boxes, confectionery dishes, cosmetic boxes, cigarette packaging, and relatively recently for foods such as ice cream lids. As the laminate, one aluminum foil does not permeate water and is difficult to adhere, but the other paper base has good water permeation, and a bonding method using wet lamination is employed exclusively for adhesion.

  Various synthetic resin emulsions such as vinyl acetate resin emulsion, ethylene-vinyl acetate resin emulsion and acrylic and styrene / acrylic copolymer resin emulsions are used as adhesives for wet lamination of aluminum foil and paper.

  The performance required for these adhesives includes initial and normal adhesive strength, water resistance, especially water-resistant adhesive strength, drying furnace temperature after bonding (110 to 120 ° C.), and the heat of printing ink when printing. Heat resistance is required to withstand the drying temperature. For example, as a simple test method for heat resistance, it is required that the paper side of the laminate is heated with a lighter to prevent the adhesion surface from being burned. For example, in applications such as ice cream lids, when the lid is repeatedly opened and closed several times, if an adhesive with low water resistance is used, the aluminum surface easily peels off. In addition, freezer resistance (-10 ° C, left for 24 hours) is also required. Furthermore, when adhering to other adherends, such as for the secondary processing of laminates, it may easily peel off due to the moisture of the adhesive, and the aluminum foil and paper laminating adhesive has strong water resistance. Required (for example, see Non-Patent Document 1).

  In response to the above requirements, an aqueous solution such as casein is added to the various synthetic resin emulsions in particular to impart water resistance and heat resistance. However, casein is a natural product and has the disadvantage of being easily spoiled as well as price fluctuations, and has a problem in the long-term storage stability of the adhesive. In addition, the conventional resins have taken measures for imparting a crosslinked structure by self- and external crosslinking, but the above-mentioned required performance has not been sufficiently satisfied, and there are many problems in storage stability.

"Adhesion applied technology", Japan Technical Library Co., Ltd.

  The object of the present invention is mainly related to wet lamination such as adhesion between paper and aluminum foil, excellent in environmental suitability and workability, water resistance, heat resistance, freezing resistance, cold resistance, oil resistance, corrosion resistance, etc. of the laminate. An object of the present invention is to provide an aqueous adhesive composition for wet laminating that can improve the viscosity.

  As a result of intensive studies to achieve the above object, the present inventors have found that a water-dispersible resin composition containing a resin composition obtained by emulsion polymerization of a monomer mixture having a specific composition can achieve the above object. The present invention has been completed.

  That is, the present invention comprises 0.1 to 5% by weight of a hydrolyzable silyl group-containing polymerizable unsaturated monomer (a), 0.1 to 10% by weight of an acid group-containing polymerizable unsaturated monomer (b), 0% Emulsifying a polymerizable unsaturated monomer mixture comprising 0.1 to 10% by weight of an epoxy group-containing polymerizable unsaturated monomer (c) and 75 to 99.7% by weight of another polymerizable unsaturated monomer (d) An aqueous adhesive composition for wet lamination comprising a resin composition obtained by polymerization is provided.

  Examples of the other polymerizable unsaturated monomer (d) include (meth) acrylic acid alkyl ester (d-1), styrene monomer (d-2), (meth) having 1 to 18 carbon atoms in the alkyl group. ) Acrylonitrile (d-3), amide bond-containing polymerizable unsaturated monomer (d-4), hydroxyl group-containing polymerizable unsaturated monomer (d-5) and polyfunctional vinyl group-containing polymerizable unsaturated monomer (d-6) At least one monomer selected from the group consisting of can be used.

  The aqueous adhesive composition for wet laminate preferably includes a resin composition obtained by emulsion polymerization in the presence of a reactive surfactant.

  The water-based adhesive composition for wet laminate of the present invention is excellent in environmental suitability and workability, and can improve the water resistance, heat resistance, freezing resistance, cold resistance, oil resistance, corrosion resistance and the like of the laminate.

  In the present invention, the water-dispersible resin composition constituting the water-based adhesive composition for wet lamination includes a hydrolyzable silyl group-containing polymerizable unsaturated monomer (a) and an acid group-containing polymerizable unsaturated monomer (b). And a resin composition obtained by emulsion polymerization of a polymerizable unsaturated monomer mixture comprising an epoxy group-containing polymerizable unsaturated monomer (c) and another polymerizable unsaturated monomer (d). .

The hydrolyzable silyl group-containing polymerizable unsaturated monomer (a) is not particularly limited as long as it is an unsaturated monomer having a silyl group in the molecule. For example, γ- (meth) acryloxypropyltrimethoxysilane, γ Alkoxysilyl groups such as (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, and γ- (meth) acryloxypropyltriethoxysilane (C _1-4 alkoxysilyl groups, etc.) Containing a monomer (such as a silyl group-containing acrylic monomer).

  By using these hydrolyzable silyl group-containing polymerizable unsaturated monomers (a) for copolymerization, the affinity with a metal material such as aluminum foil is increased, the adhesion is improved, and the water resistance of the adhesive film is improved. In particular, water-resistant adhesion, heat resistance, and cold resistance are improved.

  The amount of the hydrolyzable silyl group-containing polymerizable unsaturated monomer (a) used is 0.1 to 5% by weight, more preferably 0.3 to 3% by weight, based on the total amount of the unsaturated monomer mixture. It is. When the amount of the monomer (a) used is less than 0.1% by weight, the above characteristics do not appear, and when it is more than 5% by weight, aggregation leads to a decrease in polymerization stability, storage stability and film-forming property.

  As the acid group-containing polymerizable unsaturated monomer (b), for example, an ethylenically unsaturated monomer compound having at least one acid group selected from a carboxyl group, a sulfonic acid group, a phosphoric acid group and the like in the molecule is used. it can. Among the acid group-containing polymerizable unsaturated monomers (b), examples of the carboxyl group-containing polymerizable unsaturated monomers include acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, α-ethylacrylic acid, β-ethylacrylic acid, β-propylacrylic acid, β-isopropylacrylic acid, itaconic acid, maleic anhydride, fumaric acid, β-carboxyethyl acrylate [β-CEA, manufactured by Daicel UC Corporation] and the like can be mentioned. In addition, a carboxyl group-containing polymerizable unsaturated monomer having a long side chain and a low glass transition temperature (Tg) marketed under the trade name “Light Ester HOA-MS” (manufactured by Kyoeisha Chemical Co., Ltd.) can also be used effectively. Examples of the sulfonic acid group-containing ethylenically unsaturated monomer include p-vinylbenzenesulfonic acid, p-acrylamidepropanesulfonic acid, t-butylacrylamidesulfonic acid, and the like. Examples of the phosphoric acid group-containing polymerizable unsaturated monomer include 2-hydroxyethyl (meth) acrylate phosphate monoester, 2-hydroxypropyl (meth) acrylate phosphate monoester, and the like. Ester PM "(manufactured by Kyoeisha Chemical Co., Ltd.) is commercially available. These can be used alone or in combination of two or more. Of these, a carboxyl group-containing polymerizable unsaturated monomer is preferable.

  When the acid group-containing polymerizable unsaturated monomer (b) is used for copolymerization, the stability of the resulting resin emulsion, such as storage stability, mechanical stability, stability against freezing, and the like are improved. Strong adhesion to aluminum foil and paper surface can be obtained.

  The amount of the acid group-containing polymerizable unsaturated monomer (b) used is 0.1 to 10% by weight, more preferably 0.5 to 7% by weight, based on the total amount of the polymerizable unsaturated monomer mixture. is there. When the amount of the monomer (b) used is less than 0.1% by weight, the above-mentioned characteristics such as improvement in stability are not exhibited. When the amount used is more than 10% by weight, the polymerization stability is lowered by aggregation and the water resistance of the film Decreases and the water-resistant adhesive strength is poor.

  The epoxy group-containing polymerizable unsaturated monomer (c) is not particularly limited as long as it is a polymerizable unsaturated monomer having an epoxy group. For example, glycidyl acrylate, glycidyl methacrylate (GMA), glycidyl crotonate, glycidyl allyl ether, β -Glycidyl methacrylate etc. are mentioned. In addition to the above, for example, (3,4-epoxychlorohexyl) methyl methacrylate, 3-epoxychloro-2-hydroxypropyl methacrylate and the like can also be used. These can be used alone or in combination of two or more. Of these, glycidyl methacrylate is preferable.

  By using the epoxy group-containing polymerizable unsaturated monomer (c) for the copolymerization, it reacts with the acid group-containing polymerizable unsaturated monomer (b) to form a crosslinked structure. For this reason, the heat resistance of the adhesive resin film Water resistance and cold resistance are improved, and troubles such as film peeling after laminating under severe conditions in various applications can be prevented.

  The amount of the epoxy group-containing polymerizable unsaturated monomer (c) used is 0.1 to 10% by weight, preferably 0.5 to 7% by weight, based on the total amount of the polymerizable unsaturated monomer mixture. . When the amount of the monomer (c) used is less than 0.1% by weight, the above-mentioned characteristics do not appear, and when it is more than 10% by weight, the polymerization stability, storage stability, film-forming property and adhesiveness are lowered.

  Of the polymerizable unsaturated monomer mixture, a hydrolyzable silyl group-containing polymerizable unsaturated monomer (a), an acid group-containing polymerizable unsaturated monomer (b), and an epoxy group-containing polymerizable unsaturated monomer ( Examples of the other polymerizable unsaturated monomer (d) occupying the remainder of c) include (meth) acrylic acid alkyl ester (d-1) having 1 to 18 carbon atoms in the alkyl group, styrene monomer (d) -2), (meth) acrylonitrile (d-3), amide bond-containing polymerizable unsaturated monomer (d-4), hydroxyl-containing polymerizable unsaturated monomer (d-5), and polyfunctional vinyl group-containing polymerizable unsaturated And monomer (d-6). These monomers can be used alone or in combination of two or more. Hereinafter, the “other polymerizable unsaturated monomer (d)” may be simply referred to as “monomer (d)”.

  Examples of (meth) acrylic acid alkyl ester (d-1) having 1 to 18 carbon atoms in the alkyl group include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth ) N-butyl acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, (meth) acrylic Examples include decyl acid, dodecyl (meth) acrylate, and stearyl (meth) acrylate. These 1 type (s) or 2 or more types are used in combination as appropriate. Of these, alkyl (meth) acrylic acid alkyl ester having 1 to 10 carbon atoms is preferable.

  Examples of the styrene monomer (d-2) include α-methylstyrene, vinyltoluene and the like in addition to styrene. These monomers can be used alone or in combination of two or more.

  (Meth) acrylic acid alkyl ester (d-1) and styrene monomer (d-2) having 1 to 18 carbon atoms in the alkyl group have good film formability, hardness, flexibility, Can impart flexibility.

  When (meth) acrylonitrile (d-3) is used as a copolymerization monomer, a dense and tough film is formed by the orientation and crystallization effect in the resin due to the cyano group in the molecule, and the cohesive strength and heat resistance of the adhesive. Can improve the performance.

  Examples of the amide bond-containing polymerizable unsaturated monomer (d-4) include acrylamide, methacrylamide, α-ethylacrylamide, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, N-methylacrylamide, and N-methylmethacrylate. Examples include amide, N-methylolacrylamide, N-methylolmethacrylamide, methylenebisacrylamide, methylenebismethacrylamide, diacetoneacrylamide, and N-vinylpyrrolidone.

  When the amide bond-containing polymerizable unsaturated monomer (d-4) is used as a copolymerization monomer, it gives Newtonian liquid-like viscosity to the adhesive composition and improves workability such as adhesive leveling and rollability. sell.

  The hydroxyl group-containing polymerizable unsaturated monomer (d-5) is not particularly limited as long as it is an unsaturated monomer having a hydroxyl group. For example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, methacryl Examples thereof include hydroxyl group-containing acrylic monomers such as hydroxypropyl acid, hydroxybutyl acrylate, hydroxybutyl methacrylate, and ε-caprolactone-modified acrylic monomer. These 1 type (s) or 2 or more types are used in combination. As the ε-caprolactone-modified acrylic monomer, trade names “Placcel FA-1”, “Placcel FA-2”, “Placcel FA-3”, “Placcel FA-4”, “Placcel FA” manufactured by Daicel Chemical Industries, Ltd. -5 "," Placcel FM-1 "," Placcel FM-2 "," Placcel FM-3 "," Placcel FM-4 "," Placcel FM-5 "and the like.

  By using the hydroxyl group-containing polymerizable unsaturated monomer (d-5) as a copolymerization component, the hydrophilicity of the film is improved, the wettability to the aluminum foil surface and the paper surface is increased, and the adhesion is improved.

  Examples of the polyfunctional vinyl group-containing polymerizable unsaturated monomer (d-6) include divinylbenzene, ethylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, allyl (meth) ) Divinyl monomers such as acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate; Trivinyl monomers such as pentaerythritol tri (meth) acrylate and trimethylolpropane tri (meth) acrylate; dipentaerythritol Examples thereof include hexavinyl monomers such as hexa (meth) acrylate. These may be used alone or in combination of two or more.

  By using the polyfunctional vinyl group-containing polymerizable unsaturated monomer (d-6) as a copolymerization component, a crosslinked structure is formed inside the emulsion particles, and the hydrolyzable silyl group-containing polymerizable unsaturated monomer (a) and The crosslinkability of the adhesive composition can be further promoted by a synergistic effect with the crosslinked structure of the epoxy group-containing polymerizable unsaturated monomer (c). For this reason, the heat resistance and water resistance of the adhesive resin film are improved, and troubles such as film peeling after lamination under severe conditions in various applications can be prevented.

  As the monomer (d), it is preferable to use at least the (meth) acrylic acid alkyl ester (d-1) in order to obtain good film formability, and in particular, the (meth) acrylic acid alkyl ester (d- It is also preferable to use 1) and a styrene monomer (d-2) in combination. The (meth) acrylic acid alkyl ester (d-1) or the (meth) acrylic acid alkyl ester (d-1) and the styrenic monomer (d-2) together with (meth) acrylonitrile (d-3) , An amide bond-containing polymerizable unsaturated monomer (d-4), a hydroxyl group-containing polymerizable unsaturated monomer (d-5), and a polyfunctional vinyl group-containing polymerizable unsaturated monomer (d-6). Preferably at least one monomer is used.

  The amount of the (meth) acrylic acid alkyl ester (d-1) is, for example, 30 to 100% by weight, preferably 35 to 80% by weight, more preferably 40 to 70% by weight, based on the total amount of the monomer (d). Degree. The amount of the styrene monomer (d-2) is, for example, about 0 to 70% by weight, preferably about 10 to 60% by weight, and more preferably about 15 to 55% by weight with respect to the total amount of the monomer (d). The amount of (meth) acrylonitrile (d-3) is usually 0 to 20% by weight (for example 1 to 20% by weight), preferably 0 to 10% by weight (for example 1) with respect to the total amount of monomer (d). -10 wt%).

  The amount of the amide bond-containing polymerizable unsaturated monomer (d-4) is usually 0 to 10% by weight (for example 0.5 to 10% by weight), preferably 0.5 to 0.5% based on the total amount of the monomer (d). It is about 5% by weight (for example, 1 to 5% by weight). The amount of the hydroxyl group-containing polymerizable unsaturated monomer (d-5) is usually 0.1 to 20% by weight (for example 0.2 to 20% by weight), preferably 0.2%, based on the total amount of the monomer (d). About 10 to 10% by weight (for example, 0.5 to 5% by weight). The amount of the polyfunctional vinyl group-containing polymerizable unsaturated monomer (d-6) is usually from 0 to 5% by weight (for example, from 0.1 to 5% by weight), preferably from 0.005% by weight, based on the total amount of the monomer (d). About 1 to 3% by weight.

  Emulsion polymerization can be carried out by heating the monomer components (a), (b), (c) and (d) in an aqueous liquid with stirring in the presence of a radical polymerization initiator and an emulsifier. The reaction temperature is preferably about 30 to 100 ° C., for example, and the reaction time is preferably about 1 to 10 hours, for example. The reaction temperature may be adjusted by adding the monomer mixed solution or the monomer pre-emulsified solution all at once to a reaction vessel charged with water and an emulsifier (for example, a reactive surfactant) or dropping it for a while.

  As the radical polymerization initiator, known initiators usually used in emulsion polymerization of acrylic resins can be used. Specifically, as a water-soluble free radical polymerization initiator, for example, persulfates such as potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, etc., these oxidizing agents, sodium bisulfite, thio So-called redox initiators composed of a combination with a reducing agent such as sodium sulfate, Rongalite, and ascorbic acid are each used in the form of an aqueous solution.

  As the emulsifier used in the emulsion polymerization of the present invention, any of a non-reactive general emulsifier and a reactive surfactant can be used. Of these, the use of a reactive surfactant is advantageous in terms of adhesive performance.

  The non-reactive general emulsifier is not particularly limited. For example, a hydrocarbon group having 6 or more carbon atoms, carboxylate, sulfonate, sulfate partial ester, phosphate, phosphoric acid. An anionic or nonionic (nonionic) emulsifier is used from a micelle compound having a hydrophilic moiety such as a salt partial ester in the same molecule; a micelle compound having a polyoxyalkylene group in the molecule. Among these, as an anionic emulsifier, alkali metal salt or ammonium salt of sulfuric acid half ester of alkoxyphenols or higher alcohols; alkali metal salt or ammonium salt of alkyl or allyl sulfonate; polyoxyethylene alkylphenyl ether, polyoxyethylene Examples thereof include alkali metal salts or ammonium salts of alkyl ether or polyoxyethylene allyl ether sulfate half ester. Examples of nonionic emulsifiers include polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, and polyoxyethylene allyl ether. These may be used alone or in combination of two or more. These general-purpose anionic and nonionic emulsifiers are used in combination with various anionic and nonionic reactive activators having radical polymerizable unsaturated double bonds in the molecule as described below. The

  The reactive surfactant is not particularly limited, and includes a group containing a reactive group such as a polymerizable unsaturated group, and a group that exhibits a surfactant activity such as a nonionic hydrophilic group or an anionic hydrophilic group. Any reactive surfactant having the following may be used: Examples of the group containing a reactive group such as a polymerizable unsaturated group include a vinyl group, an allyl group, a methacryl group, an allyloxy group, a methallyloxy group, an acryloyl group, a methacryloyl group, an acryloyloxy group, and a methacryloyloxy group. It is done.

  Representative reactive surfactants are represented, for example, by the following formula (1), (2), (3), (4), (5), (6), (7) or (8). Compounds are included.

（式中、Ａ¹は炭素数２〜４の置換若しくは無置換のアルキレン基、Ｒ¹は水素原子又はメチル基、ｋは３〜２０の整数、ｍは２〜１００の整数、Ｍはアルカリ金属又はＮＨ₄を示す）

(In the formula, A ¹ is a substituted or unsubstituted alkylene group having 2 to 4 carbon atoms, R ¹ is a hydrogen atom or a methyl group, k is an integer of 3 to 20, m is an integer of 2 to 100, and M is an alkali metal. or an NH ₄₎

（式中、Ａ²は炭素数２〜４の置換若しくは無置換のアルキレン基、Ｒ²は水素原子又はメチル基、Ｒ³は炭素数７〜２４の炭化水素基又は炭素数７〜２４のアシル基、Ｘは水素原子、又はノニオン系若しくはアニオン系の親水基、ｎは０〜１００の整数を示す）

(In the formula, A ² is a substituted or unsubstituted alkylene group having 2 to 4 carbon atoms, R ² is a hydrogen atom or a methyl group, R ³ is a hydrocarbon group having 7 to 24 carbon atoms or an acyl having 7 to 24 carbon atoms. Group, X represents a hydrogen atom, or a nonionic or anionic hydrophilic group, and n represents an integer of 0 to 100)

（式中、Ａ³は炭素数２〜４の置換若しくは無置換のアルキレン基、Ｒ⁴は炭素数１〜１８の炭化水素基、Ｒ⁵は水素原子又は炭素数１〜１８の炭化水素基、ｐは２〜２００の整数、Ｍはアルカリ金属原子又はＮＨ₄を示す）

(In the formula, A ³ represents a substituted or unsubstituted alkylene group having 2 to ⁴ carbon atoms, R ⁴ represents a hydrocarbon group having 1 to 18 carbon atoms, R ⁵ represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, p is an integer of 2 to 200, M represents an alkali metal atom or NH ₄ )

（式中、Ａ⁴は炭素数２〜４の置換若しくは無置換のアルキレン基、Ｒ⁶は水素原子又はメチル基、Ｒ⁷は水素原子又はアルキル基、ｑは０〜１００の整数、Ｚは水素原子又はＳＯ₃Ｍ、Ｍはアルカリ金属又はＮＨ₄を示す）

(Wherein A ⁴ is a substituted or unsubstituted alkylene group having 2 to ⁴ carbon atoms, R ⁶ is a hydrogen atom or a methyl group, R ⁷ is a hydrogen atom or an alkyl group, q is an integer of 0 to 100, and Z is hydrogen. Atom or SO ₃ M, M represents alkali metal or NH ₄ )

（式中、Ｒ⁸は置換基を有していてもよい炭化水素基、Ｒ⁹は水素原子又はメチル基、Ｍはアルカリ金属又はＮＨ₄を示す）

（式中、Ｒ¹⁰は置換基を有していてもよい炭化水素基、Ｒ¹¹は水素原子又はメチル基、Ｍはアルカリ金属又はＮＨ₄を示す）

(In the formula, R ⁸ represents a hydrocarbon group which may have a substituent, R ⁹ represents a hydrogen atom or a methyl group, and M represents an alkali metal or NH ₄ )

(In the formula, R ¹⁰ is a hydrocarbon group which may have a substituent, R ¹¹ is a hydrogen atom or a methyl group, M is an alkali metal or NH ₄ )

（式中、Φは多官能フェニル基、Ｒ¹²は水素原子又はメチル基、ｒ、ｓは、それぞれ、１〜１００の整数、Ｍはアルカリ金属又はＮＨ₄を示す）

（式中、Ｒ¹³は水素原子又はメチル基、Ｍはアルカリ金属又はＮＨ₄を示す）

(Wherein Φ is a polyfunctional phenyl group, R ¹² is a hydrogen atom or a methyl group, r and s are each an integer of 1 to 100, and M is an alkali metal or NH ₄ )

(Wherein R ¹³ represents a hydrogen atom or a methyl group, M represents an alkali metal or NH ₄ )

In the formula (1), examples of the substituted or unsubstituted alkylene group having 2 to 4 carbon atoms in A ¹ include, for example, ethylene, propylene, trimethylene, tetramethylene group, and halogen atom (fluorine atom, chlorine atom). Etc.), an alkylene group to which a substituent such as a hydroxyl group or an alkoxy group (C _1-4 alkoxy group such as methoxy or ethoxy group) is bonded. Examples of the alkali metal in M include sodium and potassium. m is preferably an integer of about 2 to 50. As the reactive surfactant represented by the formula (1), AQUALON KH series (trade names “AQUALON KH-05”, “AQUALON KH-10”, etc.) manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) are commercially available. ing.

In the formula (2), the substituted or unsubstituted alkylene group having 2 to 4 carbon atoms for A ^2, are the same as those of the substituted or unsubstituted alkylene group having 2 to 4 carbon atoms in the A ^1. Examples of the hydrocarbon group having 7 to 24 carbon atoms in R ³ include alkyl groups such as octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl and octadecyl groups; alkenyl groups such as octenyl and decenyl groups; 4-methylphenyl, Examples thereof include alkylaryl groups such as 4-propylphenyl, 4-octylphenyl, 4-nonylphenyl, 4-decylphenyl, 4-dodecylphenyl, 4-tetradecylphenyl and 4-hexadecylphenyl groups. Examples of the acyl group having 7 to 24 carbon atoms in R ³ include aliphatic, alicyclic or aromatic acyl groups such as octanoyl, nonanoyl, dodecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl and 4-nonylbenzoyl groups. Is mentioned.

（式中、Ａ⁵は炭素数２〜４の置換若しくは無置換のアルキレン基、Ｍはアルカリ金属又はＮＨ₄、ｔは０〜１００の整数を示す）
で表される基が例示される。Ａ⁵における炭素数２〜４の置換若しくは無置換のアルキレン基としては、前記Ａ¹における炭素数２〜４の置換若しくは無置換のアルキレン基と同様のものが挙げられる。Ｍにおけるアルカリ金属としては、例えば、ナトリウム、カリウムなどが挙げられる。ｔは好ましくは０〜３０の整数である。式（２）において、ｎは、好ましくは０〜５０程度の整数である。 Examples of the nonionic or anionic hydrophilic group in X include various groups including a polyoxyalkylene group, a sulfonic acid group, and a carboxyl group. As a representative group, the following formula (9)

(In the formula, A ⁵ represents a substituted or unsubstituted alkylene group having 2 to 4 carbon atoms, M represents an alkali metal or NH ₄ , and t represents an integer of 0 to 100)
The group represented by these is illustrated. Examples of the substituted or unsubstituted alkylene group having 2 to 4 carbon atoms in A ⁵ include the same as the substituted or unsubstituted alkylene group having 2 to 4 carbon atoms in A ¹ . Examples of the alkali metal in M include sodium and potassium. t is preferably an integer of 0 to 30. In the formula (2), n is preferably an integer of about 0-50.

In the formula (3), examples of the substituted or unsubstituted alkylene group having 2 to 4 carbon atoms in A ³ include the same as the substituted or unsubstituted alkylene group having 2 to 4 carbon atoms in A ¹ . Examples of the hydrocarbon group having 1 to 18 carbon atoms in R ⁴ and R ⁵ include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, hexyl, octyl, nonyl, decyl, dodecyl, Alkyl groups such as hexadecyl and octadecyl groups; alkenyl groups such as vinyl, allyl, hexenyl, octenyl, nonenyl and decenyl groups; aralkyl groups such as benzyl, 2-phenylethyl, 3-phenylpropyl and 4-phenylbutyl groups It is done. Among these, a hydrocarbon group having 4 to 18 carbon atoms is particularly preferable. The alkali metal in M is the same as described above. p is preferably an integer of about 2 to 50.

In the formula (4), the substituted or unsubstituted alkylene group having 2 to 4 carbon atoms in A ^4, are the same as those of the substituted or unsubstituted alkylene group having 2 to 4 carbon atoms in the A ^1. Examples of the alkyl group in R ⁷ include about 1 to 20 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, hexyl, octyl, nonyl, decyl, dodecyl, and hexadecyl groups. And the like. q is preferably an integer of about 0 to 50. The alkali metal in M is the same as described above. As the reactive surfactant represented by the formula (4), trade name “Adekaria Soap SR-10” manufactured by Asahi Denka Kogyo Co., Ltd. is commercially available.

In the formulas (5) and (6), examples of the hydrocarbon group which may have a substituent in R ⁸ and R ¹⁰ include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t -Alkyl groups such as butyl, hexyl, octyl, nonyl, decyl, dodecyl, hexadecyl, octadecyl group; alkenyl groups such as vinyl, allyl, hexenyl, octenyl, nonenyl, decenyl groups; cycloalkyl groups such as cyclohexyl groups; phenyl groups, etc. Aryl groups such as benzyl and 2-phenylethyl; or a halogen atom (fluorine atom, chlorine atom, etc.), hydroxyl group, alkoxy group (C _1-4 alkoxy group such as methoxy, ethoxy group, etc.) And hydrocarbons to which substituents such as are bonded. M is the same as described above.

  In the formula (7), M is the same as described above. Each of r and s is preferably an integer of about 1 to 50. In the formula (10), M is the same as described above.

  The reactive surfactant is copolymerized or grafted with the monomer components (a), (b), (c) and (d), and exists as a constituent unit of a high molecular weight polymer after polymerization. For this reason, non-reactive general emulsifiers exist in the low-molecular form in the aqueous phase even after polymerization in the form of free water-soluble materials, and the final cast film of the resin dispersion is therefore water resistant and adhesive. On the other hand, a cast film of a resin dispersion obtained using a reactive surfactant exhibits high water resistance and adhesiveness.

  The amount of the reactive surfactant used in the emulsion polymerization is about 0.3 to 6% by weight based on the total amount of the monomer components (a), (b), (c) and (d). When the amount used is less than 0.3% by weight, the stability of emulsion polymerization is poor, and grit is likely to occur during the polymerization, and the stability of the resin dispersion obtained after the polymerization is poor and the commercial value is poor. It will be a thing. On the other hand, if it exceeds 6% by weight, there is a possibility that the water resistance and adhesiveness may be hindered, and it may be a problem in economy and the like, which is not preferable.

  Emulsion polymerization methods include any one of the following, such as the usual one-stage continuous monomer uniform dropping method, the core-shell polymerization method which is a multistage monomer feed method, and the power feed polymerization method in which the monomer composition fed continuously during the polymerization is changed. Can be legal.

  Thus, the water dispersible resin composition which comprises the adhesive composition of this invention is prepared. The weight average molecular weight of the resin in the resin composition is not particularly limited, but is generally about 20,000 to 500,000, preferably about 40,000 to 400,000.

  You may add additives, such as a basic compound, to a water-dispersible resin composition. Examples of the basic compound include ammonia, various amines, alkali metal salts and the like. By adding the basic compound, part or all of the acid contained in the water-dispersible resin composition is neutralized, and the stability of the water-dispersible resin composition is ensured.

  The resin in the water-dispersible resin composition constituting the aqueous adhesive composition for wet laminate of the present invention includes a structural unit containing a hydrolyzable silyl group, a structural unit containing an acid group, and a structural unit containing an epoxy group. It is out. In the water-based adhesive composition for wet laminates of the present invention, these crosslinkable functional groups form a crosslinked structure at the time of film formation, thereby exhibiting strong adhesion to aluminum foil or paper.

  In the aqueous adhesive composition for wet laminate of the present invention, a film-forming aid such as methyl cellosolve, carbitol, triethylene glycol, texanol may be used. Moreover, you may mix | blend well-known additives, such as an antifoamer, a thickener, a freezing stabilizer, another wetting agent, a pigment, water-soluble resin, a penetration aid, and antiseptic | preservative as needed.

  The aqueous adhesive composition for wet laminating of the present invention can be used as an adhesive for wet laminating for adhering a metal foil such as aluminum foil and a paper surface such as imitation paper or paperboard. By laminating using the adhesive composition of the present invention, the laminate exhibits strong adhesiveness, is provided with resistance to creases, tears and scratches, water resistance and heat resistance, high temperature, high humidity, etc. It does not peel even under harsh conditions.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In the following, “parts” and “%” are all based on weight unless otherwise specified.

（ｋ′は９、１１、Ｍはアルカリ金属又はＮＨ₄を示す）
で表される反応性界面活性剤［商品名「アクアロンＫＨ−１０」、第一工業製薬（株）製］０．５部を仕込み、７５℃に昇温した。別途、次に示すモノマー、乳化剤及び水の混合液を高圧ホモジナイザーを用いて均一に乳化し、モノマー乳化液として滴下ロートに仕込んだ。
（モノマー乳化液）
反応性界面活性剤［式（１０）］ １３部
ＳＭ（スチレン） １３０部
ＭＭＡ（メタクリル酸メチル） ５５部
ＢＡ（アクリル酸ブチル） ２６０部
ＭＡＡ（メタクリル酸） １３部
ＧＭＡ（グリシジルメタアクリレート） ２０部
Ａ−１７４（日本ユニカー（株）製、γ−メタクリロキシプロピルトリメトキシシラン） ５部
水 ２２０部
また、別途次に示す滴下用開始剤水溶液を別の滴下ロートに仕込んだ。
（滴下用開始剤水溶液）
過硫酸アンモニウム １．５部
水 ５０部
次に、前記反応容器内に、前記モノマー乳化液の５％を添加し、７５℃に加熱後、前記滴下用開始剤水溶液の５％を投入し、１０分間プレ重合反応を行った。この間反応容器の内温は自動的に８０℃に上昇した。その後、残りのモノマー乳化液及び滴下用開始剤水溶液を８０℃で３時間かけて一定速度で同反応容器内に滴下した。滴下終了後８０℃に保持して１時間熟成反応を行い、室温に冷却した後、アンモニア水（２５％）５部を反応容器内に投入し、水分散性樹脂組成物を得た。この接着剤組成物は、固形分濃度４８．０％、粘度６２００ｍＰａ・ｓ、ｐＨ８．６であった。 Example 1
In a normal reaction vessel for producing an acrylic resin emulsion equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser, 260 parts of water and the following formula (10) included in the formula (1)

(K ′ is 9, 11 and M is an alkali metal or NH ₄ )
0.5 parts [trade name “AQUALON KH-10”, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.] were charged, and the temperature was raised to 75 ° C. Separately, a mixed liquid of the following monomer, emulsifier and water was uniformly emulsified using a high-pressure homogenizer, and charged into a dropping funnel as a monomer emulsion.
(Monomer emulsion)
Reactive surfactant [Formula (10)] 13 parts SM (styrene) 130 parts MMA (methyl methacrylate) 55 parts BA (butyl acrylate) 260 parts MAA (methacrylic acid) 13 parts GMA (glycidyl methacrylate) 20 parts A-174 (manufactured by Nihon Unicar Co., Ltd., γ-methacryloxypropyltrimethoxysilane) 5 parts Water 220 parts Separately, the following dropping initiator aqueous solution was charged into another dropping funnel.
(Initiator aqueous solution for dripping)
Ammonium persulfate 1.5 parts Water 50 parts Next, 5% of the monomer emulsion is added to the reaction vessel, heated to 75 ° C., and then 5% of the dropping initiator aqueous solution is added for 10 minutes. A prepolymerization reaction was performed. During this time, the internal temperature of the reaction vessel automatically increased to 80 ° C. Thereafter, the remaining monomer emulsion and the dropping initiator aqueous solution were dropped into the reaction vessel at a constant rate at 80 ° C. over 3 hours. After completion of dropping, the mixture was kept at 80 ° C. for 1 hour and cooled to room temperature, and then 5 parts of ammonia water (25%) was added into the reaction vessel to obtain a water-dispersible resin composition. This adhesive composition had a solid content concentration of 48.0%, a viscosity of 6200 mPa · s, and a pH of 8.6.

Example 2
In Example 1, instead of using 130 parts of SM and 55 parts of MMA, the same operation as in Example 1 was carried out except that SM185 part was used to obtain the desired adhesive composition. This adhesive composition had a solid content concentration of 48.1%, a viscosity of 5800 mPa · s, and a pH of 8.5.

Example 3
In Example 1, instead of using 130 parts of SM and 55 parts of MMA, 185 parts of MMA were used in exactly the same manner as in Example 1 to obtain the desired adhesive composition. This adhesive composition had a solid content concentration of 47.9%, a viscosity of 6700 mPa · s, and a pH of 8.7.

Example 4
In Example 1, in place of 55 parts of MMA, 50 parts of MMA and 5 parts of divinylbenzene were used, and the same operation as in Example 1 was performed to obtain a target adhesive composition. This adhesive composition had a solid content concentration of 47.8%, a viscosity of 6100 mPa · s, and a pH of 8.6.

Example 5
In Example 1, instead of the reactive surfactant [trade name “AQUALON KH-10”, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.], the same amount of the following formula (11) contained in the formula (4) Except for using the reactive surfactant [trade name “Adekaria Soap SR-10” manufactured by Asahi Denka Kogyo Co., Ltd.], the same operation as in Example 1 was performed to obtain the desired adhesive composition. .

（式中Ｒ^7'はアルキル基を示す）
この接着剤組成物は、固形分濃度４８．０％、粘度６３００ｍＰａ・ｓ、ｐＨ８．６であった。

(Wherein R ^{7 ′} represents an alkyl group)
This adhesive composition had a solid content concentration of 48.0%, a viscosity of 6300 mPa · s, and a pH of 8.6.

Comparative Example 1
In Example 1, instead of MMA 55 parts and MAA 13 parts, the same operation as Example 1 was performed except that MMA 68 parts was used, but gelation occurred during the reaction, and the desired adhesive composition was not obtained. It was.

Comparative Example 2
In Example 1, in place of 55 parts of MMA and 20 parts of GMA, the same operation as in Example 1 was carried out except that 75 parts of MMA was used to obtain the desired adhesive composition. This adhesive composition had a solid content concentration of 48.0%, a viscosity of 6100 mPa · s, and a pH of 8.7.

Comparative Example 3
In Example 1, instead of 5 parts of MMA 55 parts and A-174 [manufactured by Nippon Unicar Co., Ltd., γ-methacryloxypropyltrimethoxysilane] 5 parts, the same operation as Example 1 was used except that MMA 60 parts was used. The target adhesive composition was obtained. This adhesive composition had a solid content concentration of 48.1%, a viscosity of 6300 mPa · s, and a pH of 8.6.

Comparative Example 4
In Example 1, MMA 55 parts, GMA 20 parts, A-174 (manufactured by Nihon Unicar Co., Ltd., γ-methacryloxypropyltrimethoxysilane) instead of 5 parts was used, except that 80 parts of MMA was used. Thus, the intended adhesive composition was obtained. This adhesive composition had a solid content concentration of 48.1%, a viscosity of 6000 mPa · s, and a pH of 8.6.

Evaluation Test The following evaluation tests were performed on the adhesive compositions obtained in the examples and comparative examples. The results are shown in Table 1.

(1) Production of sample (laminate) Each of the adhesive compositions obtained in Examples and Comparative Examples was coated with a bar coater No. 1 on the glossy surface of an aluminum foil (aluminum foil) having a thickness of 7 μm. The sample was prepared by coating at 3 and bonding to kraft paper [Daiko Paper Co., Ltd.] having a basis weight of 84 g / m ² , drying at 80 ° C. for 30 seconds, and curing at room temperature for 24 hours. The following evaluation test was performed on this laminate sample.

(2) Normal adhesive strength About the sample produced according to the above method, it was also hand-rubbed 10 times, and the peeled state at the interface between the kraft paper and the aluminum foil was visually observed and evaluated according to the following criteria.
○: 100% of the interface between the kraft paper and the aluminum foil is adhered.
Δ: 50% or more and less than 100% of the interface between the kraft paper and the aluminum foil are adhered.
X: An area exceeding 50% or the entire surface of the sample is peeled off.

(3) Water-resistant adhesive strength The sample was immersed in water at 20 ° C. for 24 hours, pulled up and allowed to stand for 24 hours. The peeled state of the aluminum foil was visually observed and evaluated according to the following criteria.
○: No change in appearance such as wrinkles in the sample, and 100% of the kraft paper is bonded to the aluminum foil.
Δ: Wrinkles are generated on the entire surface of the sample, and less than 50% is in a peeled state at the interface between the kraft paper and the aluminum foil.
X: An area of 50% or more or the entire surface of the sample is in a peeled state at the interface between the kraft paper and the aluminum foil.

(4) Heat resistance The appearance of the sample when the lighter was brought close to the paper surface of the sample was visually observed and evaluated according to the following criteria.
○: No blistering or peeling.
(Triangle | delta): A blister and peeling are seen in 1-3 places.
X: 4 or more, or blistering or peeling is seen on the entire surface.

(5) Freezing resistance The sample was left in a freezer at −20 ° C. for 24 hours, and the state after removal was visually observed and evaluated according to the following criteria.
○: No change in appearance such as wrinkles in the sample, and 100% of the kraft paper is bonded to the aluminum foil.
Δ: Wrinkles are generated on the entire surface of the sample, and less than 50% is in a peeled state at the interface between the kraft paper and the aluminum foil.
X: An area of 50% or more or the entire surface of the sample is in a peeled state at the interface between the kraft paper and the aluminum foil.

Claims (3)

  0.1 to 5% by weight of a hydrolyzable silyl group-containing polymerizable unsaturated monomer (a), 0.1 to 10% by weight of an acid group-containing polymerizable unsaturated monomer (b), 0.1 to 10% by weight A resin obtained by emulsion polymerization of a polymerizable unsaturated monomer mixture comprising an epoxy group-containing polymerizable unsaturated monomer (c) and 75 to 99.7% by weight of another polymerizable unsaturated monomer (d) An aqueous adhesive composition for wet lamination comprising the composition.   Other polymerizable unsaturated monomers (d) are (meth) acrylic acid alkyl ester (d-1), styrenic monomer (d-2), (meth) acrylonitrile (alkyl group having 1-18 carbon atoms) d-3), amide bond-containing polymerizable unsaturated monomer (d-4), hydroxyl group-containing polymerizable unsaturated monomer (d-5) and polyfunctional vinyl group-containing polymerizable unsaturated monomer (d-6) The water-based adhesive composition for wet laminating according to claim 1, which is at least one monomer selected from the above. The aqueous adhesive composition for wet lamination according to claim 1, comprising a resin composition obtained by emulsion polymerization in the presence of a reactive surfactant.