JP2002003806A - Adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an adhesive which is excellent in bonding strength with water resistance, standing stability, and workability for applying. SOLUTION: The adhesive comprises a vinyl ester resin emulsion, which is prepared by utilizing a vinyl alcohol polymer containing 0.5 mol% or more and 10 mol% and less of ethylene units as a dispersant and incorporating a glycol ether compound on the occasion of the emulsion polymerization to obtain the vinyl ester resin emulsion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive which is excellent in water-resistant adhesive strength and storage stability, and is also excellent in coatability.

[0002]

2. Description of the Related Art Conventionally, polyvinyl alcohol (hereinafter referred to as P
VA may be abbreviated) is an ethylenically unsaturated monomer,
Particularly, it is widely used as a protective colloid for emulsion polymerization of a vinyl ester monomer represented by vinyl acetate, and a vinyl ester aqueous emulsion obtained by emulsion polymerization using this as a protective colloid is for paper and woodwork. It is widely used as various adhesives for plastics and the like. By adjusting the degree of saponification of the PVA-based polymer, the aqueous emulsion used as an adhesive as described above generally has a low viscosity, a viscosity close to a Newtonian flow, and a relatively good water resistance. As a result, it is generally used in various applications because it can provide a product having a high viscosity and relatively low temperature dependence of the emulsion viscosity. As the woodworking adhesive, a higher viscosity emulsion is preferable, and a vinyl ester aqueous emulsion using so-called partially saponified PVA as a protective colloid is widely used. A vinyl ester-based aqueous emulsion using partially saponified PVA as a protective colloid has excellent low-temperature stability and is easily obtained with high viscosity, but has a problem of poor water resistance. On the other hand, vinyl ester-based aqueous emulsions using completely saponified PVA as a protective colloid have a problem that they are excellent in water resistance, but are inferior in low-temperature stability. In order to solve such problems, JP-A-63-46252, JP-A-64-62347 and the like disclose 3-methyl-3-methoxybutanol and water-soluble compounds having an alcoholic OH group. It is proposed to contain
Although water resistance, storage stability and the like have been improved, there is a limit to the conventional partially saponified PVA and completely saponified PVA. Under such circumstances, it has been proposed to use a vinyl alcohol-based polymer containing an ethylene unit as a dispersant (JP-A-11-21529, JP-A-11-21380, JP-A-10-22677).
No. 4, publication No. 4, etc.), and the water resistance and the low-temperature storage stability were greatly improved. However, vinyl alcohol-based polymers containing ethylene units are
Emulsions whose water-solubility has been reduced and the vinyl alcohol-based polymer has been used as a protective colloid are 60 to 80 ° C.
At the time of emulsion polymerization by the method.
If a remarkable increase in the viscosity occurs during emulsion polymerization, stirring may become poor and an emulsion may not be obtained stably. Therefore, it has been necessary to reduce the solid content and adjust so that stirring does not become poor even at high temperatures. For this reason, the resulting emulsion necessarily has a low viscosity, and is currently unsuitable for applications requiring a high viscosity such as an adhesive for woodworking. Also, the obtained emulsion similarly thickens at a high temperature of 40 ° C. or higher,
There was a problem in storage stability at high temperatures. Emulsions containing a vinyl alcohol-based polymer containing ethylene units as protective colloids have excellent low-temperature storage stability. Completely saponified products are used. However, since it is a completely saponified product, the surface activity is lower than that of the conventional partially saponified PVA,
The particle size of the obtained emulsion increases. When the particle diameter is large, when an adhesive containing an emulsion is applied to a base material, the adhesive hardly penetrates, so that there is a problem that the coatability is poor.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an adhesive excellent in water-resistant adhesive strength and storage stability under such circumstances, and further excellent in coating property. It is.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to develop an adhesive having the above-mentioned preferable properties.
The vinyl alcohol polymer contained below as a dispersant,
When emulsion polymerization of vinyl ester resin emulsion,
The present inventors have found that an adhesive characterized by containing a vinyl ester-based resin emulsion obtained by containing a glycol ether compound satisfies the above object, and have completed the present invention.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A vinyl alcohol-based polymer containing 0.5% by mole or more and 10% by mole or less of ethylene units used in the present invention (hereinafter referred to as a low ethylene-modified PVA-based polymer There is no particular limitation on the production method of the above-mentioned compounding, and it can be obtained by saponifying a copolymer of vinyl ester and ethylene by a known method.

[0006] Here, as the vinyl ester,
Examples thereof include vinyl formate, vinyl acetate, vinyl propionate, and vinyl pivalate. In general, vinyl acetate is preferably used.

[0007] The dispersant may be a copolymer of an ethylenically unsaturated monomer copolymerizable within a range not to impair the effects of the present invention. Such ethylenically unsaturated monomers include, for example, propylene, acrylic acid, methacrylic acid, fumaric acid, (anhydrous) maleic acid, (anhydride) itaconic acid, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, trimethyl -(3-acrylamido-3-dimethylpropyl) -ammonium chloride, acrylamido-2-methylpropanesulfonic acid and its sodium salt, ethyl vinyl ether, butyl vinyl ether, N-vinylpyrrolidone, vinyl chloride, vinyl bromide, vinyl fluoride, N-vinyl amides such as vinylidene chloride, vinylidene fluoride, tetrafluoroethylene, sodium vinyl sulfonate, sodium allyl sulfonate, N-vinyl pyrrolidone, N-vinyl formamide, N-vinyl acetamide And the like.
Further, in the presence of a thiol compound such as thiolacetic acid or mercaptopropionic acid, a terminal-modified product obtained by copolymerizing ethylene and a vinyl ester-based monomer such as vinyl acetate and saponifying it can also be used. .

The ethylene content of the low ethylene-modified PVA polymer used as a dispersant in the present invention is 0.5
Mole% or more and 10 mol% or less are essential. If the ethylene content is less than 0.5 mol%, the resulting adhesive may have poor shelf stability at low temperatures, which is inconvenient. This is inconvenient because the water solubility, which is a feature of the above, may decrease. The saponification degree of the low ethylene-modified PVA polymer used in the present invention is not particularly limited, but usually 80 mol% or more, preferably 85 mol%, more preferably 95 mol% or more is used. Can be When the degree of saponification is less than 80 mol%, there is a concern that the water solubility, which is an inherent property of the low ethylene-modified PVA polymer, is reduced. Although the degree of polymerization of the low ethylene-modified PVA polymer is not particularly limited, it is usually 100 to 800.
A range of 0 is used, and 300 to 3000 is more preferably used. When the degree of polymerization is less than 100, the characteristics of the low ethylene-modified PVA-based polymer as a protective colloid are not exhibited, and when it exceeds 8,000, there is a problem in industrial production of the low ethylene-modified PVA-based polymer. There is.

The amount of the low ethylene-modified PVA polymer used is not particularly limited, but may be 0.5 to 15 parts by weight based on 100 parts by weight of the solid content of the vinyl ester resin emulsion.
Parts by weight, preferably 1 to 10 parts by weight, more preferably 1.5 to 7 parts by weight. If the amount of the low ethylene-modified PVA-based polymer is less than 0.5 part by weight, polymerization stability may be reduced. On the other hand, when it exceeds 15 parts by weight, there is a concern that the water-resistant adhesive strength of the obtained adhesive is reduced.

The vinyl ester monomers constituting the dispersoid of the vinyl ester resin emulsion used in the adhesive of the present invention include vinyl formate, vinyl acetate, vinyl propionate and vinyl pivalate. Vinyl is preferably used.

In the present invention, an adhesive obtained by copolymerizing a vinyl ester monomer with ethylene and using an ethylene-vinyl ester resin emulsion is also a preferred embodiment. In this case, the ethylene content of the ethylene-vinyl ester-based resin emulsion is not particularly limited, but usually from 3 to 35% by weight. Preferably,
5 to 30% by weight. When the ethylene content is less than 3% by weight, the effect of introducing the ethylene is small, and the film forming property of the emulsion may be poor. When the ethylene content exceeds 35% by weight, there is a concern that it becomes difficult to produce an ethylene-vinyl ester resin emulsion.

The above dispersoid may be copolymerized with another ethylenically unsaturated monomer or diene monomer which can be copolymerized as long as the effects of the present invention are not impaired. At least one monomer unit selected from ethylenically unsaturated monomers and diene monomers includes olefins such as propylene and isobutylene, and halogenated compounds such as vinyl chloride, vinyl fluoride, vinylidene chloride and vinylidene fluoride. Olefins, acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, acrylates such as 2-hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate,
Methacrylates such as butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, 2-hydroxyethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate and quaternized products thereof, further, acrylamide,
Methacrylamide, N-methylolacrylamide,
N, N'-dimethylacrylamide, acrylamide-2-
Acrylamide monomers such as methylpropanesulfonic acid and its sodium salt, styrene, α-methylstyrene, p-styrenesulfonic acid and sodium, styrene monomers such as potassium salt, and other N-vinylpyrrolidone, Diene monomers such as butadiene, isoprene and chloroprene; furthermore, divinylbenzene, tetraallyloxyethane, N, N'-methylenebis-acrylamide, 2,2'-bis (4-acryloxypolyethoxyphenyl) propane, 1 1,3-butylene glycol diacrylate, 1,5-pentanediol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate Acrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate,
Pentaerythritol tetraacrylate, allyl methacrylate, 1,4-butanediol diacrylate, ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,6-hexanediol dimethacrylate, diethylene glycol dimethacrylate, Triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, trimethylolethane trimethacrylate, trimethylolpropane trimethacrylate, 2,2-bis (4-methacryloxypolyethoxyphenyl) propane, Aluminum methacrylate, zinc methacrylate, calcium methacrylate, methacrylate Magnesium lylate, N,
N'-m-phenylene bismaleimide, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, diallyl chlorendate, polyfunctional monomers such as ethylene glycol diglycidyl ether acrylate and the like. These may be used alone or as a mixture of two or more.

The glycol ether compound used in the adhesive of the present invention includes, for example, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether,
Ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol monopropyl ether, ethylene glycol dipropyl ether, ethylene glycol monobutyl ether, ethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol monoethyl ether, propylene glycol Examples include diethyl ether, propylene glycol monopropyl ether, propylene glycol dipropyl ether, propylene glycol monobutyl ether, and propylene glycol dibutyl ether. Furthermore, diethylene glycol monomethyl ether which is a condensate of ethylene glycol, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, diethylene glycol dihexyl ether, triethylene glycol monomethyl ether, tetraethylene glycol dimethyl ether, pentaethylene glycol diethyl ether, Hexaethylene glycol dipropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol dimethyl ether, tetrapropylene glycol dimethyl ether, hexapropylene glycol dimethyl ether, diethyle Glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, 3-methoxy-1-butanol, 3-methoxy-3-methyl-1-butanol. Among these, a glycol ether compound having a hydroxyl group is preferable, and 3-methoxy-3-methyl-1-butanol is particularly preferably used. As a commercial product, Kuraray Co., Ltd. Solfit may be mentioned. These may be used alone, or two or more kinds may be selected and used in combination.

The amount of the glycol ether compound to be added is not particularly limited, but is 0.5 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the solid content of the vinyl ester resin emulsion. If the addition amount is less than 0.5 part by weight, the particle size of the obtained emulsion becomes large, and the coating property may be deteriorated. On the other hand, if it exceeds 20 parts by weight, there is a concern that the polymerization stability of the vinyl ester-based resin emulsion is reduced.

The average particle size of the vinyl ester resin emulsion used in the adhesive of the present invention is not particularly limited.
Usually, the value measured by the dynamic light scattering method is preferably 1 μm or less, more preferably 0.8 μm or less, and still more preferably 0.5 μm or less. Average particle size is 1μm
If the ratio exceeds the above range, there is a concern that the coatability of the adhesive is reduced. The measurement by the dynamic light scattering method can be performed by, for example, a laser zeta potentiometer ELS-8000 manufactured by Otsuka Electronics Co., Ltd.

The solid content of the adhesive of the present invention is not particularly limited, but is usually 30 to 70% by weight, preferably 50 to 65% by weight.
% By weight. If the solid content is less than 30% by weight, the emulsion may have poor storage stability and may be separated into two phases. If it exceeds 70% by weight, there is a concern that the production of the adhesive becomes difficult.

The method for producing the vinyl ester resin emulsion used for the adhesive of the present invention is not particularly limited, but in a reaction vessel, an aqueous solution of a low ethylene-modified PVA polymer is used as a dispersant, and in the presence of a glycol ether compound, A vinyl ester monomer is added temporarily or continuously, and an azo polymerization initiator, a polymerization initiator such as a peroxide polymerization initiator such as hydrogen peroxide, ammonium persulfate and potassium persulfate are added, and emulsification is performed. Conventional methods of polymerizing may be mentioned. Also,
In the case of an ethylene-vinyl ester-based resin emulsion, a method in which an aqueous solution of a low ethylene-modified PVA-based polymer is used as a dispersant in an autoclave, ethylene is pressed, and emulsion polymerization is performed in the presence of a glycol ether compound. The polymerization initiator may be used in combination with a reducing agent and used in a redox system. In that case, hydrogen peroxide is usually used together with tartaric acid, L-ascorbic acid, Rongalit and the like. Further, ammonium persulfate and potassium persulfate are used together with sodium hydrogen sulfite, sodium hydrogen carbonate and the like.

As the adhesive of the present invention, the emulsion obtained by the above method can be used as it is. However, if necessary, various known emulsions may be added within a range not to impair the effects of the present invention. Can be used. Further, additives commonly used can be added to the adhesive of the present invention. Examples of the additive include organic solvents (aromatics such as toluene and xylene, alcohols,
Ketones, esters, halogen-containing solvents, etc.), plasticizers, precipitation inhibitors, thickeners, flow improvers, preservatives, rust inhibitors, defoamers, fillers, wetting agents, coloring agents, etc. Is mentioned.

The adhesive of the present invention is excellent in water-resistant adhesive strength and shelf stability, and is also excellent in coating properties, so that it can be used for secondary processing (kneading) of flash panels, laminated materials, wood veneers, and plywood. Adhesive for woodwork, woodwork, paper tube,
It is suitably used as an adhesive for bag making, paper for interleaf paper, cardboard, etc., an adhesive for paperwork such as pulp, an adhesive for plywood / PVC, etc.

[0020]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the following Examples and Comparative Examples, “parts” and “%” mean on a weight basis unless otherwise specified.

Example 1 A 1-liter glass polymerization vessel equipped with a reflux condenser, a dropping funnel, a thermometer and a nitrogen inlet was charged with 279.
2 parts, PVA-1 (polymerization degree 1000, saponification degree 99.2)
(Mol%, ethylene unit content: 7 mol%), and 19.5 parts were charged and completely dissolved at 95 ° C. Next, after cooling this PVA aqueous solution, 20.8 parts of 3-methoxy-3-methyl-1-butanol (manufactured by Kuraray Co., Ltd.) was added. While replacing with nitrogen and stirring at 200 rpm, 6
After the temperature was raised to 0 ° C., 4.4 parts of a 10% aqueous solution of tartaric acid and 3 parts of a 5% hydrogen peroxide solution were added in a shot, and 26 parts of vinyl acetate was charged to initiate polymerization. 30 minutes after the start of the polymerization, completion of the initial polymerization was confirmed. A 10% aqueous solution of tartaric acid is added to 0.
After 9 parts and 3 parts of 5% hydrogen peroxide aqueous solution were added by shot, 234 parts of vinyl acetate were continuously added over 2 hours,
After the polymerization was completed, the mixture was cooled. Thereafter, the mixture was filtered using a 60-mesh stainless steel wire mesh. As a result, a polyvinyl acetate emulsion having a solid content of 48% was obtained. The obtained emulsion was diluted to a concentration of 0.2%, and the average particle size was measured (manufactured by Otsuka Electronics Co., Ltd .; Laser Zeta Electrometer ELS-8000). Next, 5 parts of dibutyl phthalate was added to and mixed with 100 parts by weight of this emulsion to obtain an adhesive. This adhesive was evaluated by the following method. Table 1 shows the results. A. Evaluation as an adhesive for woodworking (1) Normal adhesive strength (birch material) The obtained woodworking adhesive was applied to a birch material (straight grain) at 150 g / m2.
2 were applied, bonded together, and pressed under a load of 7 kg / m 2 for 16 hours, then released, and cured at 20 ° C. and 65% RH for 5 days. The normal adhesion strength of this test piece was 20 ° C, 65%
Measured under RH. (2) Hot water adhesive strength (birch material) The obtained woodworking adhesive was applied to a birch material (straight grain) at 150 g / m2.
2 were applied, bonded together and pressed under a load of 7 kg / m2 for 16 hours, then released, and cured at 20 ° C. and 65% RH for 5 days. After curing, it was immersed in warm water at 60 ° C. for 3 hours, and the compressive shear strength was measured in a wet state. (3) Coatability In performing the tests (1) and (2), the coatability of the adhesive to the birch material was evaluated according to the following criteria. The evaluation results are shown by the following: 伸 び The adhesive has good elongation and is easy to apply, 悪 the elongation is a little poor and it is necessary to apply again, × the elongation is bad and aggregates are generated. B. Evaluation as an adhesive for paperwork (4) Ring crush strength Using a processed product obtained by adhering two pieces of base paper for paper tube, JIS-P8126
Was measured at 20 ° C. and 65% RH. (5) Water Resistant Adhesive Strength The obtained paperwork adhesive was applied to kraft paper at 30 g / m2, and bonded and pressed three times with a hand roll. After drying, the obtained processed product is immersed in water at 30 ° C. for 24 hours,
Thereafter, the state of adhesion was observed. The evaluation results were evaluated as follows:
This is indicated by slight paper breakage and X peeling. C. Evaluation of stability of standing viscosity The change in viscosity after 7 days when the adhesive was left at 5 ° C and 60 ° C was observed.

Comparative Example 1 Emulsion polymerization was carried out in the same manner as in Example 1 except that the same amount of ion-exchanged water was used instead of using 3-methoxy-3-methyl-1-butanol used in Example 1. As a result, a polyvinyl acetate emulsion having a solid content of 47.8% was obtained. Evaluation of an adhesive using this emulsion was conducted in Example 1.
Was performed in the same manner as described above. The results are shown in Table 1.

Example 2 279.2 parts of the ion-exchanged water used in Example 1 was added to 207.
Emulsion polymerization was carried out in the same manner as in Example 1 except that 9 parts were used.
A polyvinyl acetate emulsion having a solid content of 55% was obtained. Evaluation of the adhesive using this emulsion was performed in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 Emulsion polymerization was carried out in the same manner as in Example 2 except that the same amount of ion-exchanged water was used instead of using 3-methoxy-3-methyl-1-butanol used in Example 2. However, the system was blocked during the polymerization, and the polymerization could not be stably terminated.

Example 3 A 1-liter glass polymerization vessel equipped with a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet was charged with 251.
8 parts and 15.6 parts of PVA-2 (degree of polymerization 1700, degree of saponification 98 mol%, ethylene unit content 4 mol%) were charged and completely dissolved at 95 ° C. Next, after cooling this PVA aqueous solution, 2.6 parts of 3-methoxy-3-methyl-1-butanol (SOLFIT manufactured by Kuraray Co., Ltd.) was added.
After replacing with nitrogen and stirring at 200 rpm,
Then, 4.4 parts of a 10% aqueous solution of tartaric acid and 3 parts of a 5% aqueous hydrogen peroxide solution were added by shots, and then vinyl acetate was added.
6 parts were charged and polymerization was started. 30 minutes after the start of the polymerization, completion of the initial polymerization was confirmed. After 0.9 parts of a 10% aqueous solution of tartaric acid and 3 parts of a 5% aqueous hydrogen peroxide solution were added in a shot, 234 parts of vinyl acetate were continuously added over 2 hours to complete the polymerization, followed by cooling. Thereafter, the mixture was filtered using a 60-mesh stainless steel wire mesh. As a result, a polyvinyl acetate emulsion having a solid content of 52% was obtained. Evaluation of an adhesive using this emulsion was conducted in Example 1.
Was performed in the same manner as described above. The results are shown in Table 1.

Comparative Example 3 Emulsion polymerization was carried out in the same manner as in Example 3, except that the same amount of ion-exchanged water was used instead of using 3-methoxy-3-methyl-1-butanol used in Example 3. As a result, a polyvinyl acetate emulsion having a solid concentration of 51.8% was obtained. Evaluation of an adhesive using this emulsion was conducted in Example 1.
Was performed in the same manner as described above. The results are shown in Table 1.

Comparative Example 4 Instead of using PVA-2 used in Example 3, PVA-
3 (degree of polymerization 1700, degree of saponification 98.5 mol%;
Emulsion polymerization was carried out in the same manner as in Example 3 except that Kuraray-made PVA-117) was used to obtain a polyvinyl acetate emulsion having a solid content concentration of 52.1%. Evaluation of the adhesive using this emulsion was performed in the same manner as in Example 1. The results are shown in Table 1.

Example 4 72.7 parts of a 5.5% aqueous solution of PVA-1 was placed in a pressure-resistant autoclave equipped with a nitrogen inlet, a thermometer and a stirrer.
After charging 4 parts of methoxy-3-methyl-1-butanol (manufactured by Kuraray Co., Ltd.), the temperature was raised to 60 ° C., and then the atmosphere was replaced with nitrogen. After charging 80 parts of vinyl acetate, ethylene was pressurized to 40 kg / cm ² , and 0.5%
2 parts of an aqueous hydrogen peroxide solution and 0.3 part of a 2% Rongalite aqueous solution were injected under pressure to initiate polymerization. When the residual vinyl acetate concentration became 10%, ethylene was released, ethylene pressure was set to 20 kg / cm ^2, and 0.3 part of a 3% aqueous hydrogen peroxide solution was injected to complete the polymerization. No aggregation during polymerization, excellent polymerization stability, solid content concentration 55%,
An ethylene-vinyl acetate resin emulsion having an ethylene content of 20% by weight was obtained. Evaluation of the adhesive using this emulsion was performed in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 5 Emulsion polymerization was carried out in the same manner as in Example 4 except that the same amount of ion-exchanged water was used instead of using 3-methoxy-3-methyl-1-butanol used in Example 4. However, the system was blocked during the polymerization, and the polymerization could not be stably terminated.

Example 5 In a pressure-resistant autoclave equipped with a nitrogen inlet, a thermometer and a stirrer, 76 parts of a 5% aqueous solution of PVA-2, 3-methoxy-3-methyl-1-butanol (Solfit manufactured by Kuraray Co., Ltd.) ) 0.8 parts was charged, the temperature was raised to 60 ° C, and then the atmosphere was replaced with nitrogen. After charging 80 parts of vinyl acetate, ethylene was pressurized to 30 kg / cm ² , and 2 parts of a 0.5% aqueous hydrogen peroxide solution and 0.3 parts of a 2% Rongalite aqueous solution were injected to initiate polymerization. 10% residual vinyl acetate concentration
At which point ethylene was released and ethylene pressure 20
kg / cm ^2, and 0.3 parts of a 3% aqueous hydrogen peroxide solution was injected under pressure to complete the polymerization. There was no aggregation during the polymerization, the polymerization stability was excellent, and an ethylene-vinyl acetate resin emulsion having a solid content of 53.1% and an ethylene content of 15% by weight was obtained. Evaluation of the adhesive using this emulsion was performed in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 6 Emulsion polymerization was carried out in the same manner as in Example 5 except that the same amount of ion-exchanged water was used instead of using 3-methoxy-3-methyl-1-butanol used in Example 5. An ethylene-vinyl acetate emulsion having a solids concentration of 52.8% and an ethylene content of 15% by weight was obtained. Evaluation of the adhesive using this emulsion was performed in the same manner as in Example 1. The results are shown in Table 1.

Example 6 Instead of using PVA-1 used in Example 1, PVA-
4 (polymerization degree 1000, saponification degree 99 mol%, ethylene unit content 0.5 mol%) emulsion polymerization was carried out in the same manner as in Example 1 to obtain a polyacetic acid having a solid concentration of 48.5%. A vinyl emulsion was obtained. Evaluation of the adhesive using this emulsion was performed in the same manner as in Example 1.
The results are shown in Table 1.

Example 7 Instead of using PVA-1 used in Example 1, PVA-
5 (polymerization degree 500, saponification degree 99 mol%, ethylene unit content 10 mol%) emulsion polymerization was carried out in the same manner as in Example 1 to obtain a polyvinyl acetate system having a solid concentration of 48.2%. An emulsion was obtained. Evaluation of the adhesive using this emulsion was performed in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 7 Instead of using PVA-1 used in Example 1, PVA-
Emulsion polymerization was carried out in the same manner as in Example 1 except that 6 (polymerization degree: 1000, saponification degree: 99.1 mol%, ethylene unit content: 0.2 mol%). A polyvinyl acetate emulsion was obtained. Evaluation of the adhesive using this emulsion was performed in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 8 Instead of using PVA-1 used in Example 1, PVA-
Emulsion polymerization was attempted in the same manner as in Example 1 except that 7 (polymerization degree: 1000, saponification degree: 99.1 mol%, ethylene unit content: 17 mol%). However, in this example, PVA-
When the aqueous solution of No. 7 was prepared, cloudiness was observed, and it was observed that the water solubility was reduced by ethylene modification. Furthermore, when emulsion polymerization was performed, gelation occurred during the polymerization,
A stable emulsion could not be obtained.

[0036]

[Table 1]

PVA-1; degree of polymerization 1000, degree of saponification 99.
2 mol%, ethylene unit content 7 mol% PVA-2; polymerization degree 1700, saponification degree 98 mol%, ethylene unit content 4 mol% PVA-3; polymerization degree 1700, saponification degree 98.5 mol%
(Kuraray Co., Ltd. PVA-117) PVA-4; degree of polymerization 1000, degree of saponification 99 mol%, ethylene unit content 0.5 mol% PVA-5; degree of polymerization 500, degree of saponification 99 mol%, ethylene unit contained Amount 10 mol% PVA-6; degree of polymerization 1000, degree of saponification 99.1 mol%, ethylene unit content 0.2 mol% PVA-7; degree of polymerization 1000, degree of saponification 99.1 mol%, ethylene unit content 17 Mol%

[0038]

The adhesive of the present invention is excellent in water-resistant adhesive strength, shelf stability, and also excellent in coatability, and is therefore suitably used as various adhesives for woodworking, paperwork and the like.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J011 KA15 KA16 KA29 4J040 DD022 DE011 DE021 HB15 JA03 LA07 MA08 MA09 MB03 QA03 4J100 AA02Q AG02P AG03P AG04P CA01 CA04 JA03

Claims (5)

[Claims] An ethylene unit having a content of 0.5 mol% or more,
An adhesive characterized by containing a vinyl ester-based resin emulsion obtained by adding a glycol ether compound when emulsion-polymerizing a vinyl ester-based resin emulsion by using a vinyl alcohol-based polymer containing at most mol% as a dispersant. . 2. The adhesive according to claim 1, wherein the vinyl ester resin emulsion is further obtained by emulsion-copolymerizing ethylene. 3. The adhesive according to claim 1, wherein the glycol ether compound is 3-methoxy-3-methyl-1-butanol. 4. The adhesive according to claim 1, wherein the adhesive is a woodworking adhesive.
3. The adhesive according to 3. 5. The adhesive according to claim 1, wherein the adhesive is a paperwork adhesive.
3. The adhesive according to 3.