JPH1036798A - Waterborne adhesive and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a waterborne adhesive, capable of manifesting the adhesive strength in a short period and excellent in initial adhesion. SOLUTION: This waterborne adhesive having high initial adhesion is obtained by combining an aqueous polymeric emulsion such as a vinyl acetate- based polymer emulsion with a hydrophobized water-soluble hydroxyethyl cellulose(HEC) and, as necessary, a surfactant such as a nonionic surfactant or an anionic surfactant. The hydrophobized HEC includes the one containing a 4-22C alkyl group or a 6-10C aryl-1 to 4C alkyl group (especially a 12-22C alkyl group) introduced as a hydrophobic group thereinto. The amounts of the respective components are about 0.1-10 pts.wt. hydrophobized HEC and about 0.01-5 pts.wt. surfactant respectively based on 100 pts.wt. resin component in the aqueous polymeric emulsion.

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 made intensive studies to achieve the above object, and as a result, have found that an aqueous polymer emulsion and a hydrophobized water-soluble hydroxyethyl cellulose (hereinafter simply referred to as hydrophobized HEC are sometimes referred to as “hydrophobic HEC”). The present invention has been found to show that a water-based adhesive exhibits a large initial adhesive force in a very short time when a surfactant is used in combination with a surfactant if necessary. Thus, the present invention has been completed. That is, the aqueous adhesive of the present invention contains an aqueous polymer emulsion and hydrophobized water-soluble hydroxyethyl cellulose.
The aqueous polymer emulsion may be an emulsion containing a vinyl acetate polymer or an acrylic polymer, and the hydrophobized HEC may be a C _6-22 alkyl group, a C _6-10 aryl-C _1-4 alkyl group. Hydroxyethylcellulose having at least one hydrophobic group selected from the group consisting of: Further, the aqueous adhesive may include a surfactant, and the surfactant may be at least one selected from an anionic surfactant and a nonionic surfactant. The content of the hydrophobized HEC is about 0.1 to 10 parts by weight based on 100 parts by weight of the resin component of the aqueous polymer emulsion, and the content of the surfactant is 100 parts by weight of the resin component of the aqueous polymer emulsion. 0.01 to 5
It may be about parts by weight. Such an aqueous adhesive is
Adhesion measuring machine (ASM-1 manufactured by Japan Tobacco Inc.)
With kraft paper as the base material, open time 0.1 seconds,
After a pressing time of 0.1 second, it exhibits a maximum adhesion of at least 0.04 kg when measured at a shear rate of 300 mm / min.

In the method of the present invention, an aqueous polymer emulsion, a hydrophobized water-soluble hydroxyethyl cellulose,
A water-based adhesive can be produced by mixing a surfactant, if necessary. The present invention also provides a method for bonding an adherend using an aqueous adhesive composed of the above components.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The aqueous adhesive of the present invention comprises an aqueous polymer emulsion, a hydrophobized HEC, and if necessary, a surfactant. 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-type adhesive containing an aqueous polymer emulsion, and the type of the resin of the polymer emulsion is not particularly limited as long as it has an adhesive ability. 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). Copolymer, methacrylic acid ester-acrylic acid ester copolymer- (meth) acrylic acid copolymer, etc.], styrene-based polymer [for example, styrene- (meth) acrylic acid ester copolymer, styrene-acrylic acid ester- ( (Meth) acrylic acid copolymer, etc.), olefin polymers [eg, polyethylene, ethylene-ethyl acrylate copolymer, etc.], vinyl chloride polymers [eg, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer] Etc.], vinylidene chloride-based copolymers [for example, vinylidene chloride-vinyl acetate copolymer, vinyl chloride A rubbery polymer [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 or the like as a main component. These polymer emulsions can be used alone or in combination of two or more.

[0008] 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 (such as ethylene), acrylates (eg, acrylic acid, ethyl acrylate, butyl acrylate, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate) C _1-10 alkyl esters such as methacrylic acid and methacrylic acid esters corresponding thereto, and vinyl esters other than vinyl acetate (eg, vinyl propionate, vinyl caprylate, vinyl caproate, vinyl versatate (VeoVa ) such as C _3-16 fatty acid vinyl esters, etc.), maleic acid or fumaric acid esters (e.g., diethyl maleate, dibutyl maleate, dioctyl maleate, maleic acid and maleic acid 2-ethylhexyl - mono- or di C _{1- 10} alkyl esters, and this Such as fumaric acid esters) corresponding to can be exemplified. These copolymerizable vinyl monomers can be used alone or in combination of two or more.

The vinyl acetate polymer is a vinyl acetate homopolymer, a copolymer of vinyl acetate and at least one monomer selected from the above-mentioned copolymerizable vinyl monomers [eg, ethylene-vinyl acetate Copolymer, vinyl acetate- (meth) acrylate copolymer, vinyl acetate- (meth) acrylate- (meth) acrylic acid copolymer, vinyl acetate-vinyl ester copolymer, vinyl acetate-maleic acid Ester (or fumaric acid ester) copolymer]. Preferred vinyl acetate polymer emulsions often contain polyvinyl alcohol as an emulsifier. The acrylic polymer includes a homopolymer or a copolymer of a (meth) acrylic monomer, and a copolymer of a (meth) acrylic monomer and a copolymerizable monomer. As the (meth) acrylic monomer, for example, (meth) acrylic acid,
Alkyl (meth) acrylate [for example, methyl (meth) acrylate, ethyl (meth) acrylate,
Butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, (meth)
2-ethylhexyl acrylate, C _1-20 alkyl esters of (meth) acrylic acid such as stearyl (meth) acrylate], hydroxyl group-containing (meth) acrylic monomers [2-hydroxyethyl (meth) acrylate, (Meth) such as 2-hydroxypropyl (meth) acrylate
Acrylic acid-hydroxy C _2-6 alkyl ester] and an epoxy group-containing (meth) acrylic monomer [glycidyl (meth) acrylate]. These monomers can be used alone or in combination of two or more.

The copolymerizable monomers include, for example, styrene monomers (such as styrene), vinyl esters (such as vinyl acetate and the above-mentioned fatty acid vinyl esters), maleic anhydride,
Fumaric acid, maleic acid ester, fumaric acid ester and the like are included. The acrylic polymer is a homo- or copolymer containing an acrylic acid C _2-10 alkyl ester unit [for example,
C _2-10 alkyl acrylate homopolymer, C _2-10 alkyl acrylate- (meth) acrylic acid copolymer, methyl methacrylate (and / or styrene) -C _2-10 alkyl acrylate copolymer A methyl methacrylate (and / or styrene) -C _2-10 alkyl acrylate- (meth) acrylic acid copolymer] in many cases. 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., and 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, and is, for example, 0.001 to 5 μm, preferably 0.01 to 5 μm.
４4 μm (for example, about 2-3 μm). In the polymer emulsion, the particle size range of the resin particles is 0.00
About 1 to 10 μm (preferably 0.01 to 5 μm, more preferably 0.1 to 5 μm, particularly 0.5 to 5 μm),
Average particle size 0.01 to 3 μm (preferably 0.05 to 3 μm
m, more preferably 0.1 to 3 μm, especially 1 to 3 μm
If 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), high initial adhesiveness can be exhibited. The solid content concentration of the polymer emulsion is usually about 30 to 60% by weight.

The polymer emulsion may be prepared by emulsion polymerization or emulsion dispersion. [Hydrophobic HEC] A feature of the present invention is that the initial adhesion is greatly improved by combining the polymer emulsion and the hydrophobized HEC. The hydrophobized HEC can be obtained by reacting alkali cellulose with a halide or an epoxy compound having ethylene oxide and a hydrophobic group, and introducing a hydrophobic group into hydroxyethyl cellulose (HEC). Examples of the hydrophobic group include a butyl group, an isobutyl group, an s-butyl group,
t-butyl group, pentyl group, hexyl group, octyl group,
2-ethylhexyl group, capryl group (decyl group), lauryl group (dodecyl group), myristyl group (tetradecyl group), palmityl group (hexadecyl group), stearyl group (octadecyl group), oleyl group, behenyl group (icosyl group), etc. C _3-10 cycloalkyl groups such as a linear or branched C _4-22 alkyl group, cyclopentyl group, cyclohexyl group and cyclooctyl group; C _6-10 aryl groups such as phenyl and naphthyl groups; benzyl and trityl _C6-10 aryl- _C1-4 such as phenethyl, benzhydryl and the like.
Examples include an alkyl group. A plurality of different types of hydrophobic groups may be introduced into HEC.

Preferred hydrophobic groups include a linear or branched C _6-22 alkyl group (particularly, a C _8-22 alkyl group, especially a C _6-22 alkyl group).
_10-22 alkyl groups), C _6-10 aryl-C _1-4 alkyl groups (ie aralkyl groups, especially phenyl-C _1-2 alkyl groups). Hydrophobized HEC has a hydrophobic group of C
_It is often water-soluble hydroxyethylcellulose into which a _12-22 alkyl group has been introduced. The halide having the hydrophobic group includes a halide corresponding to the hydrophobic group, for example, C _4-20 alkyl chloride, C _3-10 cycloalkyl chloride, _6-10 aryl chloride, C _6-10 aryl-C _1-. Chloride such as _4- alkyl chloride, and corresponding bromide are included. The epoxidized product having a hydrophobic group includes a compound having a reactive epoxy group at an appropriate position of the hydrophobic group, particularly a compound having a reactive epoxy group at a terminal.

The average degree of polymerization of the hydrophobized HEC is, for example, 1
It is about 0 to 1000, preferably about 50 to 900, and more preferably about 100 to 800. In the hydrophobized HEC, the average degree of substitution of the hydroxyethyl group is, for example, 0.1.
It is about 5 to 2.5, preferably about 1.0 to 2.5, more preferably about 1.5 to 2.0, and the content of the hydrophobic group is, for example, 0.1 to 5% by weight, preferably 0 to 5% by weight. It is about 0.5 to 3% by weight, more preferably about 0.7 to 2.5% by weight. The hydrophobized HEC may be added to the polymer emulsion, or may be used as a protective colloid in the step of preparing the polymer emulsion (for example, emulsion polymerization). The hydrophobized HEC can be used in combination with a water-soluble polymer such as polyvinyl alcohol regardless of whether it is an emulsion preparation step such as emulsion polymerization.

The amount of the hydrophobized HEC can be appropriately selected within a range in which the initial adhesion of the polymer emulsion can be improved.
Parts by weight, in terms of solid content, 0.1 to 10 parts by weight,
Preferably 0.5 to 10 parts by weight, more preferably 0.1 to 10 parts by weight.
7 to 10 parts by weight (for example, 1 to 10 parts by weight), especially 0.1 to 10 parts by weight.
It is about 8 to 5 parts by weight (for example, 1 to 2.5 parts by weight). [Surfactant] When the aqueous adhesive further contains a surfactant, not only the stability but also the initial adhesiveness can be further improved. The surfactant is not particularly limited as long as the dispersion stability and initial adhesiveness are not impaired. For example, cationic surfactants [for example, laurylamine hydrochloride, dilaurylamine hydrochloride, lauryldimethylamine hydrochloride, etc. Class-3
Salts of quaternary alkylamines, salts of alkanolamines such as ethanolamine hydrochloride, polyethylene polyamine salts such as ethylenediamine hydrochloride and diethylenetriamine hydrochloride, and quaternary ammonium salts (alkyltrimethylammonium hydrochloride, dialkyldimethylammonium hydrochloride, alkyldimethylbenzyl) Ammonium hydrochloride), morpholine, guanidine, N, N-diethylethylenediamine, aminoethylethanolamine salts and the like], anionic surfactants such as higher fatty acid salts (sodium octanoate, sodium decanoate,
C _8-20 fatty acid salts such as sodium laurate, sodium oil and sodium stearate, etc., alkyl sulfates (C _8-20 alkyl sulfate such as sodium lauryl sulfate, sodium oleyl sulfate, etc.), higher alcohol sulfates (lauryl alcohol sulfate, oleyl alcohol sulfuric acid ester salts, such as C _8-20 alcohol sulfate salts such as stearyl alcohol sulfate), higher alkyl polyethylene glycol sulfates, alpha-olefin sulfates, alkyl benzene sulfonates , Α-olefin sulfonates, alkane sulfonates, α-sulfofatty acid ester salts (such as sulfosuccinate salts), higher alcohol phosphate ester salts, dithiophosphate ester salts, etc.], amphoteric surfactants such as lauri Amino acid methyl hydrochloride, carboxylic acid salt such as lauryl dimethyl betaine,
Imidazoline derivatives etc.], nonionic surfactants [for example, 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, Higher alkylamine-ethylene oxide adducts, fatty acid amide-ethylene oxide adducts, ethylene oxide adducts of fats and oils, polypropylene glycol-ethylene oxide adducts, etc., polyhydric alcohols (glycerol, polyglycerol, pentaerythritol, sorbitol and sorbitan) , Polyoxyethylene sorbitan, fatty acid esters of polyhydric alcohols such as sucrose, alkyl ethers of polyhydric alcohols, alkanolamines Fatty acid amides, etc.), etc.] and the like. These surfactants can be used alone or in combination of two or more.

[0015] 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 surfactant may be previously contained in the polymer emulsion, or may be added when preparing the aqueous adhesive. The amount of surfactant used is
It can be selected within a range that can improve the initial adhesiveness of the polymer emulsion.
0.01 to 5 parts by weight, preferably 0.1 to 5 parts by weight
To about 3 parts by weight, more preferably about 0.2 to 2.5 parts by weight (for example, about 0.2 to 2 parts by weight).

[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), water-soluble polymers [for example,
Polyvinyl alcohol, water-soluble cellulose derivatives (eg, cellulose ethers such as methylcellulose, ethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose and carboxymethylcellulose), water-soluble acrylic resins, etc.], fillers, coloring agents, preservatives, defoamers, etc. May be included.

The amounts of these components can be selected in accordance with the type of the aqueous polymer emulsion, as long as they do not impair the film-forming properties, initial adhesiveness and stability of the aqueous adhesive.
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. Further, the amount of the film-forming aid used may be 1 to 50 parts by weight, preferably about 5 to 30 parts by weight, based on 100 parts by weight of the resin component of the aqueous polymer emulsion.
The solid content concentration of the aqueous adhesive of the present invention can be selected within a range that does not impair the initial adhesiveness. For example, the solid content concentration is 15 to 75% by weight, preferably 30 to 65% by weight, more preferably 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 (A, manufactured by Japan Tobacco Inc., A
Using SM-1), a temperature of 20 ° C., 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 the aqueous polymer emulsion, the hydrophobized HEC, and, if necessary, a surfactant. As described above, a predetermined amount of the hydrophobicized HE
When an aqueous polymer emulsion already containing C and / or a surfactant is used, it is not always necessary to add a hydrophobized HEC and / or a surfactant to the polymer emulsion.

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, using the aqueous adhesive, the adherend is subjected to high-speed (for example, 20 to 250 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, and, for example, 1 to 100.
g / m ^2, preferably 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 water-based 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.

[0021]

Since the aqueous adhesive of the present invention contains an aqueous polymer emulsion, a hydrophobized HEC and, if necessary, a surfactant, a high initial adhesiveness is exhibited within a very short time. Further, not only the stability is high, but also the initial adhesiveness is high, 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.

[0022]

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. Synthesis Example 1 In a four-necked flask equipped with a thermometer, a stirrer, a condenser, and a dropping funnel, 43.06 parts by weight of deionized water at ordinary temperature, polyvinyl alcohol (degree of saponification: 88 mol%, degree of polymerization: 1700)
1.6 parts by weight were charged and dissolved by stirring at 80 ° C. for 2 hours. The temperature 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 further raised to 80 ° C. to obtain 48.06 parts by weight of vinyl acetate.
An aqueous solution in which 0.09 parts by weight of potassium persulfate was dissolved in 3 parts by weight of deionized water 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 900
0 cps (rotational viscometer, rotor No. 4, rotation speed 30)
rpm, temperature 30 ° C.) and pH 4.6.

Synthesis Example 2 Using the same apparatus as in Synthesis Example 1, at room temperature, 46.4 parts by weight of deionized water, 1.92 parts by weight of hydrophobized HEC (trade name "Natrosol Plus 330" manufactured by Aqualon Co., Ltd.) ,
Dissolved at 80 ° C. for 2 hours. Then, vinyl acetate 4
8.00 parts by weight and an aqueous solution obtained by dissolving 0.1 part by weight of hydrogen peroxide in 3 parts by weight of deionized water were added dropwise over 4 hours. After completion of the dropwise addition, the mixture was polymerized for 2 hours while maintaining the temperature at 80 ° C.
By cooling to room temperature, the solid content concentration is 50.17% by weight and the viscosity is 12200 cps (rotational viscometer, rotor N
o. 4, rotation speed 30 rpm, temperature 30 ° C) and pH
An aqueous emulsion of 4.7 was obtained. Example 1 100 parts by weight of the emulsion obtained in Synthesis Example 1, 39.2% by weight, 19.2 parts by weight of hydrophobized HEC (manufactured by Aqualon Co., Ltd., Natrosol Plus 330), and 9 parts by weight of dibutyl phthalate.
6 parts by weight, 1% by weight aqueous solution of sodium laurin sulfate 15
By weight, 13 parts by weight of adjusted water were mixed to prepare an aqueous adhesive.

Example 2 100 parts by weight of the emulsion obtained in Synthesis Example 1, 39.2% by weight, 19.2 parts by weight of hydrophobized HEC (Natrosol Plus 330, manufactured by Aqualon Co., Ltd.), and 9 parts by weight of dibutyl phthalate
6 parts by weight, 15 parts by weight of a 1.7% by weight aqueous solution of sodium laurin sulfate and 15 parts by weight of adjusted water were mixed to prepare an aqueous adhesive. Example 3 100 parts by weight of the emulsion obtained in Synthesis Example 1, 35.6 parts by weight of 3% by weight hydrophobized HEC (Natrosol Plus 330, manufactured by Aqualon Co., Ltd.), dibutyl phthalate 1
An aqueous adhesive was prepared by mixing 0.68 parts by weight and 15 parts by weight of a 0.4% by weight aqueous solution of sodium laurin sulfate.

Example 4 100 parts by weight of the emulsion obtained in Synthesis Example 1, 53.4 parts by weight of 3% by weight hydrophobized HEC (Natrosol Plus 330, manufactured by Aqualon Co., Ltd.), dibutyl phthalate 1
An aqueous adhesive was prepared by mixing 0.68 parts by weight, 15 parts by weight of a 1.3% by weight aqueous solution of sodium laurin sulfate and 29 parts by weight of adjusted water. Example 5 100 parts by weight of the emulsion obtained in Synthesis Example 1, 35.7 parts by weight of 3% by weight hydrophobized HEC (Natrosol Plus 330, manufactured by Aqualon Co., Ltd.), dibutyl phthalate 1
An aqueous adhesive was prepared by mixing 0.68 parts by weight, 15 parts by weight of a 1.3% by weight aqueous solution of sodium decanoate and 17 parts by weight of conditioning water.

Example 6 100 parts by weight of the emulsion obtained in Synthesis Example 1, 35.67 parts by weight of 3% by weight hydrophobized HEC (Natrosol Plus 330, manufactured by Aqualon Co., Ltd.), dibutyl phthalate 1
0.68 parts by weight and 15 parts by weight of a 0.5% by weight aqueous solution of sodium laurate were mixed to prepare an aqueous adhesive. Example 7 100 parts by weight of the emulsion obtained in Synthesis Example 1, 35.67 parts by weight of 3% by weight hydrophobized HEC (Natrosol Plus 330, manufactured by Aqualon Co., Ltd.), dibutyl phthalate 1
An aqueous adhesive was prepared by mixing 0.68 parts by weight and 5.7% by weight of an aqueous solution of sodium octanoate (15 parts by weight).

Example 8 100 parts by weight of the emulsion obtained in Synthesis Example 2, 3% by weight of hydrophobized HEC (Natrosol Plus 330, manufactured by Aqualon Co., Ltd.) 16.13 parts by weight, 9.62 parts by weight of dibutyl phthalate, 15 parts by weight of a 0.7% by weight aqueous solution of sodium laurin sulfate and 15 parts by weight of adjusted water were mixed to prepare an aqueous adhesive. Example 9 100 parts by weight of the emulsion obtained in Synthesis Example 2 and 16.13 parts by weight of 3% by weight hydrophobized HEC (manufactured by Aqualon Co., Ltd., Natrosol Plus 330), 9.62 parts by weight of dibutyl phthalate, 1.1 A 15% by weight aqueous solution of sodium laurin sulfate and 20 parts by weight of adjusted water were mixed to prepare an aqueous adhesive.

Example 10 100 parts by weight of the emulsion obtained in Synthesis Example 1, 35.6 parts by weight of 3% by weight hydrophobized HEC (Natrosol Plus 330, manufactured by Aqualon Co., Ltd.), and 9 parts by weight of dibutyl phthalate
62 parts by weight and 23 parts by weight of conditioning water were mixed to prepare an aqueous adhesive. Comparative Example 1 100 parts by weight of the emulsion obtained in Synthesis Example 1, 25 parts by weight of a 15% by weight aqueous solution of polyvinyl alcohol (degree of saponification: 88 mol%, degree of polymerization: 1700), dibutyl phthalate 2
5 parts by weight were mixed to prepare an aqueous adhesive. And the initial adhesive force of the aqueous adhesive obtained in the Example and the comparative example was measured by the following method.

Adhesion 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. Table 1 shows the measurement results of the initial adhesive strength together with the characteristics of the aqueous adhesive.
And Table 2.

[0030]

[Table 1]

[0031]

[Table 2]

As is clear from Tables 1 and 2, the water-based adhesives of Examples 1 to 10 were different from those of Comparative Examples.
High initial adhesive strength is developed.

Claims (11)

[Claims] 1. An aqueous adhesive comprising an aqueous polymer emulsion and a hydrophobized water-soluble hydroxyethyl cellulose. 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. 3. The hydrophobized hydroxyethylcellulose is a hydroxyethylcellulose into which at least one hydrophobic group selected from a C _6-22 alkyl group and a C _6-10 aryl-C _1-4 alkyl group has been introduced. The aqueous adhesive according to claim 1. 4. The content of the hydrophobized hydroxyethyl cellulose in the resin component 10 of the aqueous polymer emulsion.
The aqueous adhesive according to claim 1, wherein the amount is 0.1 to 10 parts by weight based on 0 part by weight. 5. The aqueous adhesive according to claim 1, further comprising a surfactant. 6. The aqueous adhesive according to claim 6, wherein the surfactant is at least one selected from an anionic surfactant and a nonionic surfactant. 7. A surfactant content of 0.01 to 5 parts by weight per 100 parts by weight of the resin component of the aqueous polymer emulsion.
The aqueous adhesive according to claim 6, which is in parts by weight. 8. An adhesive force measuring machine (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. 9. A vinyl acetate polymer emulsion or an acrylic polymer emulsion, hydroxyethyl cellulose having a C _8-22 alkyl group introduced therein, and at least one selected from an anionic surfactant and a nonionic surfactant. An aqueous adhesive composed of a kind of surfactant. 10. A method for producing an aqueous adhesive, comprising mixing an aqueous polymer emulsion and a hydrophobized water-soluble hydroxyethyl cellulose. 11. A method for adhering an adherend using an aqueous polymer emulsion and an aqueous adhesive composed of hydrophobized water-soluble hydroxyethylcellulose.