JPH1046130A - Water-based adhesive and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-based adhesive which develops adhesiveness within a short time and has excellent initial tack. SOLUTION: This adhesive is obtained by combining an aqueous polymer emulsion with a water-soluble polymer. The water-soluble polymer contains at least one polymer selected among modified polyvinyl alcohols having cationic groups, Si-containing organic groups, mercapto groups or acyl groups, mucopolysaccharides and polyvinylpyrrolidone. It may be in the form of emulsified polymer particles or a protective colloid or may be a water-soluble polymer added to an emulsion. Its amount of use is about 1-20 pts.wt. per 100 pts.wt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous adhesive excellent in initial adhesiveness capable of exhibiting high adhesive strength in a short time, a method for producing the same, and an adhesive method using the aqueous adhesive.

[0002]

2. Description of the Related Art As an adhesive or a pressure-sensitive adhesive, a solution-type adhesive using an organic solvent as a medium is widely used. However, solution-based adhesives not only cause air pollution and fire,
There are many problems in terms of occupational safety and health and resources. Therefore, conversion to other systems, for example, aqueous emulsion of adhesives and pressure-sensitive adhesives has been actively promoted. Aqueous emulsion-type adhesives and pressure-sensitive adhesives are widely used because the above-mentioned problems of the solution-type adhesives are solved. However, since the medium is water, the drying property is poor, and the expression of the initial adhesive force is extremely slow. There is a fatal problem. In order to improve such drying properties and initial adhesiveness, methods have been proposed in which the solid content in the emulsion is increased, an organic solvent is used in combination, or heat is applied. However, these methods are still ineffective or require special equipment,
Neither is a satisfactory method.

Japanese Patent Publication No. 56-9953 discloses an adhesive composition comprising a water-based adhesive containing rubber latex as a main component and a film-forming aid.
No. 74 discloses an adhesive composition in which a two-part adhesive is formed by combining an emulsion-type aqueous adhesive and an adhesion promoter to exhibit initial adhesiveness. Further, JP-A-59-33372 proposes a method of forming a two-part adhesive by combining an aqueous polymer emulsion containing an unsaturated carboxylic acid and a polyvalent metal salt to exhibit initial adhesiveness. Have been. These methods focus on the aggregation characteristics of the emulsion, for example, salting out caused by the addition of an aqueous solution of a metal salt, or aggregation of the emulsion caused by the addition of an organic solvent or oppositely charged ions. But,
Actually, the situation remarkably differs depending on the kind of the emulsion. For example, depending on the emulsion used in the method, salting out or aggregation may not occur at all, and even if salting out or aggregation occurs, the adhesiveness to the adherend is extremely reduced, and the adhesive function is reduced. May not work.
Further, the drying property may be reduced, and the initial adhesiveness may be significantly reduced. Furthermore, in the method using an adhesion promoter or a polyvalent metal salt, it is necessary to separately apply the emulsion and the adhesion promoter or the polyvalent metal salt to the adherend,
Decrease workability. For this reason, the bonding work efficiency is reduced, and high-speed bonding may not be performed.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a water-based adhesive having a high initial adhesiveness and a method for producing the same.
Another object of the present invention is to provide a bonding method. Another object of the present invention is to provide a water-based adhesive which has not only high stability but also greatly improved initial adhesiveness and can efficiently adhere an adherend with high adhesive force, a method for producing the same, and an adhesive method. Is to do. Still another object of the present invention is to provide a water-based adhesive which can exhibit an initial adhesive force extremely quickly, improve the bonding workability, and improve the coating workability without using special equipment, a method for producing the same, and a bonding method. Is to provide.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, when an aqueous polymer emulsion and a specific water-soluble polymer are combined, the aqueous adhesive becomes extremely short. It was found that a large initial adhesive force was developed in a short time, and the present invention was completed. That is, the aqueous adhesive of the present invention comprises an aqueous polymer emulsion and a modified polyvinyl alcohol containing a cationic group, an organic group having a silicon atom, a mercapto group or an acyl group (hereinafter referred to as “modified polyvinyl alcohol”). ), At least one water-soluble polymer selected from a viscous polysaccharide and polyvinylpyrrolidone. In this aqueous adhesive, the aqueous polymer emulsion has a water-soluble polymer (hereinafter sometimes referred to as a “water-soluble polymer”) as an emulsifier and a vinyl acetate polymer or an acrylic polymer as polymer particles. Aqueous polymer emulsions containing as a polymer may be used. The content of the water-soluble polymer is 10% of the polymer particles (or the total amount of monomers) of the aqueous polymer emulsion.
It is about 1 to 20 parts by weight with respect to 0 parts by weight. Such an aqueous adhesive is prepared by using an adhesive force measuring device (ASM-1 manufactured by Nippon Tobacco Inc.) using kraft paper as a base material after an open time of 0.1 second and a pressing time of 0.1 second. When measured at a shear rate of 300 mm / min, at least 0.04 k
g indicates the maximum adhesive force.

In the method of the present invention, an aqueous adhesive is produced by mixing an aqueous polymer emulsion with at least one water-soluble polymer selected from modified polyvinyl alcohol, a viscous polysaccharide and polyvinylpyrrolidone. it can.

[0007] The method of the present invention also includes a method of bonding an adherend using the aqueous adhesive. In this method, the adherend can be bonded at a high speed of about 20 to 250 m / min.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The aqueous adhesive of the present invention is composed of an aqueous polymer emulsion and a specific water-soluble polymer. In the aqueous polymer emulsion, the water-soluble polymer may constitute at least one of a polymer particle of the emulsion and a polymer emulsifier or a protective colloid. In a preferred embodiment, the water-soluble polymer is used as a polymeric emulsifier or protective colloid in an aqueous polymer emulsion. The aqueous adhesive having such a constitution can greatly improve the initial adhesiveness as compared with the aqueous polymer emulsion alone without impairing the dispersion stability.

[Aqueous Polymer Emulsion] The aqueous adhesive constitutes an emulsion adhesive containing an aqueous polymer emulsion, and the type of resin of the polymer emulsion is not particularly limited as long as it has an adhesive ability. Resin can be used. Examples of the polymer emulsion include vinyl acetate-based polymers [polyvinyl acetate, vinyl acetate-based copolymer] and acrylic polymers [eg, poly (meth) acrylate, methacrylate-acrylate copolymer). Coalescence, methacrylic acid ester-acrylic acid ester copolymer- (meth) acrylic acid copolymer, etc.],
Styrene-based polymers [eg, styrene- (meth) acrylate copolymer, styrene-acrylate- (meth) acrylate copolymer, etc.], olefin-based polymers [eg, polyethylene, ethylene-ethyl acrylate] Copolymer, etc.], vinyl chloride-based polymer [eg, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, etc.], vinylidene chloride-based copolymer [eg, vinylidene chloride-vinyl acetate copolymer, vinylidene chloride- Acrylate copolymers and the like], rubbery polymers [for example, styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, acrylonitrile-butadiene copolymer, polychloroprene, polyisoprene, styrene-
Isoprene copolymer, maleic acid-isoprene copolymer sodium salt, etc.], and an emulsion containing polyurethane as a main component. These polymer emulsions can be used alone or in combination of two or more. Preferred polymer emulsions include aqueous emulsions containing vinyl acetate polymers and acrylic polymers. More specifically, the vinyl acetate-based polymer includes a vinyl acetate homopolymer or a copolymer of vinyl acetate and a copolymerizable vinyl monomer. Examples of the copolymerizable vinyl monomer include olefins (eg, ethylene), acrylates (eg, ethyl acrylate, butyl acrylate, isobutyl acrylate, t-butyl acrylate, and acryl such as 2-ethylhexyl acrylate). Acid C _1-10 alkyl esters, methacrylic acid esters corresponding thereto, and vinyl esters other than vinyl acetate (for example, C ₃₋ such as vinyl propionate, vinyl caprylate, vinyl caproate, vinyl versatate (VeoVa)) ₁₆ such as a fatty acid vinyl esters), maleic or fumaric acid esters (e.g., diethyl maleate, dibutyl maleate, dioctyl maleate, di C _1-10 alkyl esters such as maleic acid, 2-ethylhexyl, and corresponding to these Fumaric acid ester And others. These copolymerizable vinyl monomers can be used alone or in combination of two or more. Specific examples of the vinyl acetate-based polymer include a vinyl acetate homopolymer, a copolymer of vinyl acetate and at least one monomer selected from the above copolymerizable vinyl monomers [for example, ethylene-acetic acid Vinyl copolymer, vinyl acetate- (meth) acrylate copolymer, vinyl acetate-vinyl ester copolymer, vinyl acetate-maleate (or fumarate) copolymer, etc.]. Preferred vinyl acetate polymer emulsions often contain polyvinyl alcohol as an emulsifier.

Acrylic polymers include (meth) acrylic
Or copolymer of methacrylic monomer, (meth) acrylic monomer
And a copolymer of a copolymer and a copolymerizable monomer. (Meta)
As the acrylic monomer, for example, (meth) acrylic
Acid alkyl esters [for example, methyl (meth) acrylate]
, Ethyl (meth) acrylate, butyl (meth) acrylate
Chill, isobutyl (meth) acrylate, (meth) acrylic
T-butyl acrylate, hexyl (meth) acrylate, (meth
(T) Octyl acrylate, 2-ethyl (meth) acrylate
Lumexyl and stearyl (meth) acrylate
T) Acrylic acid C _1-20Alkyl esters etc.], Epoxy
Si group-containing (meth) acrylic monomer [(meth) acrylic
Glycidyl acid]. These monomers
Can be used alone or in combination of two or more. Copolymerizable monomer
The monomer includes, for example, a styrene monomer (such as styrene).
Etc.), vinyl esters (vinyl acetate and the above-mentioned fatty acid vinyl)
Esters), dialkyl maleate and fuma
Dialkyl luate and the like. Acrylic heavy
Coalescence is acrylic acid C_2-10Contains alkyl ester units
Homo- or copolymer [for example, acrylic acid C_2-10Alkyl
Ester homopolymer, methyl methacrylate (and / or
Styrene) -acrylic acid C_2-10Alkyl ester copolymerization
Body etc.] in many cases.

[0011] In the polymer emulsion, the glass transition temperature of the resin particles calculated according to the Tobolsky formula may be, for example, about -30 ° C to 35 ° C, preferably about -20 ° C to 30 ° C. . The average particle size of the resin particles is not particularly limited as long as the adhesiveness is not impaired,
For example, 0.001-5 μm, preferably 0.01-4
μm (for example, about 2 to 3 μm). In the polymer emulsion, the particle size range of the resin particles 0.001 to
About 10 μm (preferably 0.01 to 5 μm, more preferably 0.1 to 5 μm, particularly 0.5 to 5 μm), and an average particle size of 0.01 to 3 μm (preferably 0.05 to 3 μm;
More preferably, it is 0.1 to 3 μm, especially about 1 to 3 μm), and when the polymer particles having a particle size of 0.5 to 3 μm occupy 50 to 95% by volume (preferably 60 to 90% by volume) of the whole. Can exhibit high initial adhesiveness. The solid content concentration of the polymer emulsion is usually about 30 to 60% by weight.

The polymer emulsion may be prepared by a conventional method, for example, by emulsion polymerization of a polymerizable monomer in an aqueous system, or by emulsion dispersion of a polymer.

As the water-soluble polymer (water-soluble polymer),
For example, a modified polyvinyl alcohol (modified polyvinyl alcohol) containing a cationic group, an organic group having a silicon atom, a mercapto group or an acyl group, a viscous polysaccharide [eg, alginic acid or a salt thereof (eg, sodium salt), pectin] Etc.], polyvinyl pyrrolidone, vinyl ether-maleic anhydride copolymer, and the like.
These water-soluble polymers can be used alone or in combination of two or more.

The modified polyvinyl alcohol containing a cationic group can be obtained by saponification of a copolymer of vinyl acetate with a polymerizable monomer having a tertiary or quaternary amino group such as dimethylamino (meth) acrylate. can get. Modified polyvinyl alcohol containing an organic group having a silicon atom is a saponification of a copolymer of a polymerizable compound having a silicon atom such as dimethylpolysiloxane and vinyl acetate, and a silicone compound having a polyvinyl alcohol and a hydrolyzable group. (For example, an alkoxysilane such as dimethoxydimethylsilane). The modified polyvinyl alcohol containing a mercapto group or an acyl group can be obtained, for example, by reacting polyvinyl alcohol with a thiol or an acylating agent.

Examples of the acyl group include an acyl group having about 2 to 10 carbon atoms such as acetyl, propionyl, butyryl, and valeryl groups, and a C _1-6 alkyl-carbonyl-acyl group such as acetoacetyl and acetopropionyl. included. Preferred acyl groups include an acetoacetyl group. The proportion of the cationic group, the organic group having a silicon atom, the mercapto group or the acyl group is, for example, 0.1 to 30 parts by weight, preferably 1 to 30 parts by weight, based on 100 parts by weight of the modified polyvinyl alcohol (or the total amount of the monomers). ~ 20 parts by weight,
More preferably, it is about 5 to 15 parts by weight. Polyvinyl alcohol has a saponification degree of 80 mol% or more (for example,
82-98 mol%, preferably 83-95 mol%, more preferably about 85-92 mol%), and the degree of polymerization 500-
About 3000 polyvinyl alcohols can be used.

Preferred water-soluble polymers include modified polyvinyl alcohol, alginic acid or a salt thereof (such as a sodium salt), pectin, and polyvinylpyrrolidone.

The water-soluble polymer may be used as an emulsifier or a protective colloid during emulsion polymerization or emulsification, or may be added after preparing the emulsion. The amount of the water-soluble polymer used is, for example, 1 to 30 parts by weight (for example, 3 to 27 parts by weight), preferably 100 parts by weight of the polymer particles (or the total amount of the monomers) of the aqueous polymer emulsion. 5-20
Parts by weight, more preferably about 7 to 15 parts by weight.

When the water-soluble polymer is used as an emulsifier or protective colloid in emulsion polymerization or emulsification, the amount of the water-soluble polymer is, for example, 0.5 to 100 parts by weight of the total amount of the monomers. It is about 15 to 15 parts by weight, preferably about 1 to 10 parts by weight, and more preferably about 3 to 8 parts by weight.

The water-soluble polymer can be used in combination with a water-soluble polymer having a hydroxyl group, regardless of whether it is an emulsion preparation step such as emulsion polymerization or the like. Such a water-soluble polymer having a hydroxyl group can be used as an emulsifier or protective colloid in emulsion polymerization or emulsification. The water-soluble polymer having a hydroxyl group, for example,
Examples thereof include polyvinyl alcohol, cellulose derivatives (eg, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose), and polyoxyalkylene glycol. These water-soluble polymers can be used alone or in combination of two or more.

Preferred water-soluble polymers having a hydroxyl group include polyvinyl alcohol. As the polyvinyl alcohol, a saponification degree of 80 mol% or more (for example, 82 to 98 mol%, preferably 83 to 95 mol%,
More preferably about 85 to 92 mol%), and a degree of polymerization of 50.
About 0 to 3000 polyvinyl alcohol can be used. When a water-soluble polymer having a hydroxyl group is used as an emulsifier or protective colloid in emulsion polymerization or emulsification, the amount used can be selected within a range that does not impair the stability and initial adhesion of the emulsion. 0.5 to 7 parts by weight, preferably 1 to 100 parts by weight of the total amount of the monomer
To 5 parts by weight, more preferably about 2 to 4 parts by weight.

For the emulsion polymerization or emulsification, a surfactant may be used together with or without using the water-soluble polymer. As the surfactant, a cationic surfactant or an amphoteric surfactant may be used, but an anionic surfactant and / or a nonionic surfactant are often used. Examples of the anionic surfactant include higher fatty acid salts (eg, C _8-20 fatty acid salts such as sodium octoate, sodium decanoate, sodium laurate, sodium oleate, and sodium stearate), and alkyl sulfates (lauryl). C, such as C _8-20, such as alkyl sulfates), higher alcohol sulfuric ester salts (lauryl alcohol sulfate, oleyl alcohol sulfuric acid ester salts, stearyl alcohol sulfuric acid ester salts such as sodium, sodium oleyl sulfate _8-20
Alcohol sulfates), higher alkyl polyethylene glycol sulfates, α-olefin sulfates, alkylbenzene sulfonates, α-olefin sulfonates, alkane sulfonates, α-sulfofatty acid ester salts (sulfosuccinates, etc.) ) Can be exemplified. Examples of the nonionic surfactant include polyethylene glycol type (higher alcohol-ethylene oxide adduct, alkylphenol-ethylene oxide adduct, fatty acid-ethylene oxide adduct, polyhydric alcohol fatty acid ester-ethylene oxide adduct, polypropylene glycol-). And polyhydric alcohols (eg, fatty acid esters of polyhydric alcohols such as glycerol, polyglycerol, pentaerythritol, sorbitol and sorbitan, polyoxyethylene sorbitan, and sucrose). These surfactants can be used alone or in combination of two or more. Preferred surfactants include at least one surfactant selected from anionic surfactants and nonionic surfactants. The combined use of an anionic surfactant and a nonionic surfactant may improve dispersion stability in some cases. The amount of the surfactant used is, for example, 0.01 to 100 parts by weight of the polymer particles (or the total amount of the monomers) of the aqueous polymer emulsion.
It is about 5 parts by weight, preferably about 0.1 to 3 parts by weight, and more preferably about 0.5 to 2.5 parts by weight.

The surfactant may be previously contained in the polymer emulsion, or may be added when preparing the aqueous adhesive.

[Other components] The aqueous adhesive of the present invention comprises:
If desired, tackifiers (e.g., rosin, rosin ester, dicyclopentadiene resin, petroleum resin, styrene resin, terpene resin, cumarone-indene resin and hydrogenated products thereof), plasticizer [phthalic acid ester (dibutyl Phthalate, dihexyl phthalate, dioctyl phthalate, di-2-ethylhexyl phthalate, etc.), long-chain aliphatic polycarboxylic acid esters (dibutyl apate, di 2-ethylhexyl apate, dibutyl sebacate, etc.), phosphoric acid derivatives (triphenyl phosphate, triphenyl (2-ethylhexyl) phosphate, etc.), polyester, etc.], film-forming aids (cellosolves such as ethyl cellosolve and butyl cellosolve, and carbitols such as methyl carbitol, ethyl carbitol and butyl carbitol). Etc.), an organic solvent (alcohol,
Water-soluble or water-insoluble solvents selected from esters, ketones, ethers and hydrocarbons), fillers, coloring agents, preservatives, defoamers and the like.

The amounts of these components can be selected in accordance with the type of the aqueous polymer emulsion, as long as the film-forming properties, initial adhesiveness and stability of the aqueous adhesive are not impaired.
For example, when the aqueous polymer emulsion is an emulsion having a high glass transition temperature and a small film-forming property at room temperature, such as a polyvinyl acetate emulsion, the amount of the plasticizer used is 100% by weight of the resin component of the aqueous polymer emulsion. The amount is 1 to 50 parts by weight, preferably about 5 to 40 parts by weight based on parts. The amount of the film-forming aid used is 1 to 5 with respect to 100 parts by weight of the copolymer component of the aqueous polymer emulsion.
It may be 0 parts by weight, preferably about 5 to 30 parts by weight. The solid content of the aqueous adhesive of the present invention can be selected within a range that does not impair the initial adhesiveness.
It is about 5% by weight, preferably about 30 to 65% by weight, and more preferably about 40 to 50% by weight.

Such a water-based adhesive is prepared by using a kraft paper as a base material and an adhesive force measuring device (manufactured by Nippon Tobacco Inc., A
Using SM-1), at a temperature of 20 ° C. and a relative humidity of 65% RH,
After an open time of 0.1 second and a pressing time of 0.1 second, when measured at a shear rate of 300 mm / min, the maximum adhesive strength is at least 0.04 kg, preferably 0.05 to 0.5 kg.
(For example, 0.06 to 0.3 kg), and more preferably about 0.07 to 0.5 kg.

The aqueous adhesive of the present invention can be prepared by mixing an aqueous polymer emulsion with the water-soluble polymer. The aqueous adhesive of the present invention exhibits an initial adhesiveness in a very short time and has a high adhesive strength. Therefore, in the method of the present invention, the adherend is adhered using the aqueous adhesive. In particular, in the method of the present invention, the adherend is rapidly (for example, 20 to 2) using the aqueous adhesive.
(50 m / min, preferably 30 to 200 m / min, more preferably about 50 to 200 m / min). Bonding of the adherends can be performed by a conventional method, for example, by applying an aqueous adhesive to at least one of the adherends and bringing the adherends into contact with each other and joining them. The amount of the aqueous adhesive applied to the adherend can be selected according to the solid content concentration of the aqueous adhesive, the type of the adherend, for example, 1 to
100 g / m ^2, preferably from 5 to 70 g / m ^2, still more preferably selected from 10 to 60 g / m ² range of about. The application of the water-based adhesive can be performed by a conventional coating machine (for example, a roll coater, a gravure coater, etc.) in addition to the manual operation. May be promoted.

The aqueous adhesive of the present invention is useful for bonding various adherends (eg, paper, wood, plastic, metal, etc.). In particular, since the initial adhesive force is developed within a very short time and the initial adhesive force is extremely high, the substrate is made of various porous adherends, for example, various paper materials such as cardboard, paperboard, and kraft paper. It is suitable for bonding the body at high speed.

[0028]

Since the aqueous adhesive of the present invention is composed of an aqueous polymer emulsion and a specific water-soluble polymer, a high initial adhesive force is developed within a very short time. Further, not only is the stability high, but also the initial adhesiveness is greatly improved, and the adherend can be efficiently bonded with extremely high adhesive strength. Furthermore, since the expression of the initial adhesive force is extremely fast, the workability of the bonding can be improved, and the workability of the coating can be improved using a conventional apparatus without using any special equipment.

[0029]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. Preparation of Aqueous Polymer Emulsion Preparation Example 1 43.06 parts by weight of deionized water, 0.801 part by weight of sodium alginate, polyvinyl alcohol in a four-necked flask equipped with a thermometer, stirrer, condenser, and dropping funnel 0.801 part by weight (degree of saponification: 88 mol%, degree of polymerization: 1700) was charged and stirred at 80 ° C. for 2 hours to dissolve.

Thereafter, the mixture was cooled to 70 ° C., 5.34 parts by weight of vinyl acetate and 0.01 part by weight of potassium persulfate were added, and the temperature was raised to 80 ° C., followed by 48.06 parts by weight of vinyl acetate and deionized water. 3 parts by weight of water and 0.09 of potassium persulfate
A part by weight aqueous solution was added dropwise over 3 hours. After dropping,
Polymerization was carried out for 2 hours while maintaining the temperature at 80 ° C., and then cooled to room temperature to obtain a solid content of 55.0% by weight and a viscosity of 1180 cps.
(Rotation viscometer, rotor No. 3, rotation speed 30 rpm, temperature 30 ° C.), and an emulsion having a pH of 4.8 was obtained.

Preparation Example 2 In the same apparatus as in Preparation Example 1, 42.57 deionized water was added at room temperature.
3.1 parts by weight of a modified polyvinyl alcohol containing a cationic group (C-506, manufactured by Kuraray Co., Ltd.) was charged and stirred at 80 ° C. for 2 hours to dissolve.

Thereafter, an aqueous solution of 50.00 parts by weight of vinyl acetate, 3 parts by weight of deionized water and 0.1 part by weight of potassium persulfate was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was polymerized for 2 hours while maintaining the temperature at 80 ° C., and then cooled to room temperature.
C), pH 4.0 emulsion was obtained.

Preparation Example 3 In a device similar to that of Preparation Example 1, 42.56 deionized water was added at room temperature.
3.6 parts by weight of an acetoacetyl group-containing modified polyvinyl alcohol (Gosefimer Z-210, manufactured by Nippon Gosei Co., Ltd.) was added, and stirred at 80 ° C. for 2 hours to dissolve.

Thereafter, an aqueous solution of 51.40 parts by weight of vinyl acetate, 3 parts by weight of deionized water and 0.1 part by weight of potassium persulfate was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was polymerized for 2 hours while maintaining the temperature at 80 ° C., and then cooled to room temperature.
C), pH 2.9.

Preparation Example 4 In a device similar to that of Preparation Example 1, 42.56 deionized water was added at room temperature.
2. Modified polyvinyl alcohol containing an organic group having a silicon atom by weight (R-1130, manufactured by Kuraray Co., Ltd.)
One part by weight was charged and stirred at 80 ° C. for 2 hours to dissolve.

Thereafter, an aqueous solution of 51.89 parts by weight of vinyl acetate, 3 parts by weight of deionized water and 0.1 part by weight of potassium persulfate was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was polymerized for 2 hours while maintaining the temperature at 80 ° C., and then cooled to room temperature.
C), pH 4.8.

Preparation Example 5 In the same apparatus as in Preparation Example 1, 43.06 deionized water was added at room temperature.
A part by weight, 3.1 parts by weight of a modified polyvinyl alcohol containing a mercapto group (M-205, manufactured by Kuraray Co., Ltd.) was charged and stirred at 80 ° C. for 2 hours to be dissolved.

Thereafter, an aqueous solution of 51.89 parts by weight of vinyl acetate, 3 parts by weight of deionized water and 0.1 part by weight of potassium persulfate was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was polymerized for 2 hours while maintaining the temperature at 80 ° C., and then cooled to room temperature.
C), pH 4.0 emulsion was obtained.

Preparation Example 6 In a device similar to that of Preparation Example 1, 42.96 of deionized water was added at room temperature.
Parts by weight, polyvinylpyrrolidone (PVP K-90D,
ISP CHEMICAL CORPORATION
0.85 parts by weight) and 0.85 parts by weight of polyvinyl alcohol (88 mol% of saponification degree, polymerization degree 1700) were stirred and dissolved at 80 ° C. for 2 hours.

Thereafter, an aqueous solution of 53.4 parts by weight of vinyl acetate, 3 parts by weight of deionized water and 0.1 part by weight of potassium persulfate was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was polymerized for 2 hours while maintaining the temperature at 80 ° C., and then cooled to room temperature.
C), pH 3.3.

Preparation Example 7 In the same apparatus as in Preparation Example 1, 56.94 of deionized water was added at room temperature.
Parts by weight, 0.80 parts by weight of pectin, and 0.80 parts by weight of polyvinyl alcohol (degree of saponification: 88 mol%, degree of polymerization: 1700) were stirred and dissolved at 80 ° C. for 2 hours.

Thereafter, an aqueous solution of 53.4 parts by weight of vinyl acetate, 3 parts by weight of deionized water and 0.1 part by weight of potassium persulfate was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was polymerized for 2 hours while maintaining the temperature at 80 ° C., and then cooled to room temperature.
C), pH 3.4.

Preparation Example 8 In the same apparatus as in Preparation Example 1, 43.06 deionized water was added at room temperature.
Parts by weight, polyvinyl alcohol (degree of saponification 88 mol%,
(Polymerization degree: 1700) 1.6 parts by weight were charged and stirred at 80 ° C. for 2 hours to dissolve. Thereafter, the mixture is cooled to 70 ° C., 5.34 parts by weight of vinyl acetate and 0.01 part by weight of potassium persulfate are added, and the temperature is raised to 80 ° C., followed by 48.06 parts by weight of vinyl acetate and 3 parts by weight of deionized water. Parts and potassium persulfate 0.0
9 parts by weight of the aqueous solution was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was polymerized for 2 hours while maintaining the temperature at 80 ° C., and then cooled to room temperature to give a solid content of 54.8% by weight and a viscosity of 9000 c
ps (rotational viscometer, rotor No. 4, rotation speed 30 rp)
m, temperature 30 ° C.), and an emulsion having a pH of 4.6 was obtained.

Example 1 100 parts by weight of the emulsion obtained in Preparation Example 1, 26.7 parts by weight of 15% by weight of polyvinyl alcohol (degree of saponification: 88 mol%, degree of polymerization: 1700), dibutyl phthalate 11
By weight, 30.4 parts by weight of prepared water were mixed to prepare an aqueous adhesive.

Example 2 100 parts by weight of the emulsion obtained in Preparation Example 2, 22 parts by weight of 15% by weight polyvinyl alcohol (degree of saponification: 88 mol%, degree of polymerization: 1700), 10 parts by weight of dibutyl phthalate, 37 parts by weight of prepared water Was mixed to prepare an aqueous adhesive.

Example 3 100 parts by weight of the emulsion obtained in Preparation Example 3, 12.0 parts by weight of 15% by weight polyvinyl alcohol (degree of saponification: 88 mol%, degree of polymerization: 1700), 1 part by weight of dibutyl phthalate
0.28 parts by weight and 39.0 parts by weight of prepared water were mixed to prepare an aqueous adhesive.

Example 4 100 parts by weight of the emulsion obtained in Preparation Example 4, 15.6 parts by weight of 15% by weight polyvinyl alcohol (degree of saponification: 88 mol%, degree of polymerization: 1700), dibutyl phthalate 1
0.4 parts by weight and 36.8 parts by weight of prepared water were mixed to prepare an aqueous adhesive.

Example 5 100 parts by weight of the emulsion obtained in Preparation Example 5, 15.6 parts by weight of 15% by weight polyvinyl alcohol (degree of saponification: 88 mol%, degree of polymerization: 1700), dibutyl phthalate 1
0.4 parts by weight and 36.8 parts by weight of prepared water were mixed to prepare an aqueous adhesive.

Example 6 100 parts by weight of the emulsion obtained in Preparation Example 6, 26.7 parts by weight of 15% by weight polyvinyl alcohol (saponification degree: 88 mol%, polymerization degree: 1700), dibutyl phthalate 11
By weight, 30.4 parts by weight of prepared water were mixed to prepare an aqueous adhesive.

Example 7 100 parts by weight of the emulsion obtained in Preparation Example 7, 26.7 parts by weight of 15% by weight polyvinyl alcohol (saponification degree: 88 mol%, polymerization degree: 1700), dibutyl phthalate 11
By weight, 30.4 parts by weight of prepared water were mixed to prepare an aqueous adhesive.

Comparative Example 1 100 parts by weight of the emulsion obtained in Preparation Example 8, 25 parts by weight of 15% by weight polyvinyl alcohol (degree of saponification: 88 mol%, degree of polymerization: 1700), and 25 parts by weight of dibutyl phthalate were mixed, and the mixture was subjected to aqueous bonding. An agent was prepared.

The initial adhesive strengths of the aqueous adhesives obtained in Examples and Comparative Examples were measured by the following method.

An adhesive force measuring device (manufactured by Japan Tobacco Inc.,
The aqueous adhesive was applied at a coating amount of 40 g / m ² to kraft paper having a basis weight of 84 g / m ² as a substrate using ASM-1). After a temperature of 20 ° C., a relative humidity of 65% RH, an open time of 0.1 second and a pressing time of 0.1 second, a shearing speed of 300 m
The adhesive force was measured six times under the condition of m / min, and the average value of the maximum value of the initial adhesive force obtained for each measurement was defined as the initial adhesive force. The measurement results of the initial adhesive strength are shown in the table together with the properties of the aqueous adhesive.

[0054]

[Table 1] As is clear from the table, the aqueous adhesive of the example exhibits higher initial adhesive strength than the aqueous adhesive of the comparative example.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C09J 133/06 JDD C09J 133/06 JDD N10 139/06 JDF 139/06 JDF

Claims (8)

[Claims] 1. An aqueous polymer emulsion and at least one selected from the group consisting of a cationic group, an organic group having a silicon atom, a modified polyvinyl alcohol containing a mercapto group or an acyl group, a viscous polysaccharide, and polyvinylpyrrolidone. A water-based adhesive comprising a water-soluble polymer. 2. The aqueous adhesive according to claim 1, wherein the aqueous polymer emulsion is an emulsion containing a vinyl acetate polymer or an acrylic polymer as polymer particles. 3. The aqueous adhesive according to claim 1, wherein the aqueous polymer emulsion is an aqueous polymer emulsion containing a water-soluble polymer as an emulsifier and a vinyl acetate polymer as polymer particles. 4. The aqueous adhesive according to claim 1, wherein the content of the water-soluble polymer is 1 to 20 parts by weight based on 100 parts by weight of the polymer particles (or the total amount of the monomers) of the aqueous polymer emulsion. Agent. 5. An adhesive force measuring device (Japan Tobacco Inc.)
After making open time 0.1 second and pressing time 0.1 second using kraft paper as a base material by ASM-1), the shear rate is 30.
When measured at 0 mm / min, the maximum adhesive strength is at least 0.1 mm.
The aqueous adhesive according to claim 1, which weighs 04 kg. 6. An aqueous polymer emulsion and at least one selected from the group consisting of a modified polyvinyl alcohol containing a cationic group, an organic group having a silicon atom, a mercapto group or an acyl group, a viscous polysaccharide, and polyvinylpyrrolidone. And a water-soluble polymer. 7. A method for bonding an adherend using the aqueous adhesive according to claim 1. 8. The bonding method according to claim 7, wherein the adherend is bonded at a speed of 20 to 250 m / min.