JPH11140418A - Aqueous adhesive agent composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a two-pack type aqueous adhesive agent composition having a long pot life. SOLUTION: This aqueous adhesive composition is composed of (A) an aqueous dispersion containing a water-soluble resin and/or a water-dispersible resin and at least one kind of a stabilizer, a thickener and a filler and (B) a water- dispersible polyisocyanate composition comprising (1) a hydrophilic polyisocyanate in which 2-50 wt.% of a nonionic hydrophilic group having 1-50 ethylene oxide repeating units is introduced into an aliphatic and/or an alicyclic diisocyanate or a polyisocyanate compound obtained from the diisocyanate and (2) an ionic surfactant substantially not containing water in an amount of 0.5-20 wt.% based on the component 1. The amount of non-volatile components in the component B is 0.5-100 wt.% based on non-volatile components in the component A. The component A and the component B are individually provided and mixed at the using.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-part aqueous adhesive composition comprising an aqueous dispersion and a water-dispersible polyisocyanate composition and having a long pot life.

[0002]

2. Description of the Related Art In recent years, guidelines on volatile organic compounds have become strict, and regulations have already been implemented in the United States and Germany, and it is expected that regulations will be implemented in Japan in the near future. Accordingly, it has been desired to use an aqueous adhesive which has conventionally been obtained by adding an isocyanate to a polymer dissolved in an organic solvent to obtain a property such as adhesiveness to a base material, and the development is proceeding.

Japanese Patent Publication No. 55-7472 proposes a water-dispersible polyisocyanate in which a nonionic hydrophilic group is introduced into a polyisocyanate, and by adding this to a polyester or polyether, an adhesive, a bonding agent or the like can be obtained. It is proposed that it can be used for the agent. In addition, Japanese Unexamined Patent Publication No.
JP-A-291613 and JP-A-62-50373 propose an adhesive composition in which an aqueous emulsion and an aliphatic water-dispersible polyisocyanate composition having only a nonionic hydrophilic group are combined.

However, the conventional water-dispersible polyisocyanate composition described above uses only a nonionic group as a hydrophilic component. When the aqueous adhesive composition is used, the reactivity between the isocyanate group and water is not sufficiently suppressed, and there is a problem that a pot life that can be used practically cannot be achieved.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a two-part type water-based adhesive composition having a long pot life.

[0006]

Means for Solving the Problems The present inventors comprise a water-dispersible polyisocyanate composition obtained by mixing a water-soluble resin or a water-dispersible resin, a nonionic hydrophilic group and an ionic surfactant. The inventor has found that an aqueous adhesive composition can solve the above-mentioned problems, and has completed the present invention based on the findings.

[0007] That is, the present invention provides an aqueous dispersion comprising a water-soluble resin and / or water-dispersible resin as component (A) and an additive containing at least one or more of a stabilizer, a thickener, and a filler. As the component (B), (1) aliphatic and / or alicyclic diisocyanate or a polyisocyanate compound obtained therefrom has a nonionic hydrophilic group composed of 1 to 50 ethylene oxide repeating units,
５０50% by weight of a hydrophilic polyisocyanate introduced,
(2) A water-based adhesive composition comprising a water-dispersible polyisocyanate composition obtained by mixing 0.5 to 20% by weight of an ionic surfactant containing substantially no water with respect to (1). Wherein the nonvolatile component (B) is 0.5 to 100% by weight based on the nonvolatile component (A).
Wherein the component (A) and the component (B) are provided separately, and are configured to be mixed at the time of use.

Hereinafter, the present invention will be described in detail. In the present invention, a water-soluble resin and / or a water-dispersible resin is used as the aqueous dispersion of the component (A). The water-soluble resin is a resin that is soluble in water, and includes, for example, (meth) acrylic acid, styrene, and acryl as at least one kind of (meth) acrylic acid (C1 to C12) alkyl ester as an essential component. (Meth) acrylate resin in which a part or all of carboxylic acid of a copolymer of at least one unsaturated compound selected from unsaturated compounds such as nitrile is neutralized with an alkali component such as sodium hydroxide or ammonia. ,
Phthalic acid, isophthalic acid, terephthalic acid, maleic acid,
At least one polybasic acid selected from polybasic acids such as fumaric acid, succinic acid, adipic acid, sebacic acid and their anhydrides, and (poly) ethylene glycol, (poly) propylene glycol, trimethylolpropane ,
In the process of esterifying at least one polyhydric alcohol selected from polyhydric alcohols such as pentaerythritol and sorbitol, a part or all of the polybasic acid is neutralized with an alkaline component such as sodium hydroxide or ammonia. Polyester resins, aromatic, aliphatic, alicyclic diisocyanates or isocyanate oligomers derived therefrom and polyhydric alcohols such as (poly) ethylene glycol, (poly) propylene glycol, trimethylolpropane, pentaerythritol, sorbitol, or Bishydroxypropionic acid, at least one alcohol compound selected from hydroxycarboxylic acids such as hydroxyacetic acid is subjected to a urethane reaction, and part or all of the carboxylic acid is reacted with an alkali component such as sodium hydroxide or ammonia. Or the like can be mentioned sum polyurethane-based resin.

Further, vinyl acetate is an essential component,
(Meth) acrylic acid (having 1 to 12 carbon atoms) alkyl ester, vinyl acetate based copolymer obtained by neutralizing a part or all of the carboxylic acid of a copolymer of at least one unsaturated compound selected from unsaturated compounds such as styrene Resin, epoxy resin such as condensate of epichlorohydrin and polyhydric phenol, polyethylene oxide alone, or between polyethylene oxide repeating units, or at one or both ends, polypropylene oxide, polytetramethylene oxide, polyneopentyl glycol Polyalkylene oxide polyol-based resin added, polyvinyl alcohol, or synthetic water-soluble polymers represented by compounds in which a part of the hydroxyl group of polyvinyl alcohol is esterified with carboxylic acid, sulfonic acid compound, methyl cellulose, hydro Shi ethylcellulose, natural water-soluble polymers typified by soluble starch, and the like.

The water-dispersible resin includes everything expressed as latex or emulsion. For example, vinylidene chloride is an essential component, and at least one unsaturated compound selected from unsaturated compounds such as acrylonitrile, vinyl chloride, (meth) acrylic acid, and alkyl (meth) acrylate (1 to 12 carbon atoms) is used. Emulsion polymerization into a copolymer, if necessary, a polyvinylidene chloride copolymer neutralized with a carboxylic acid, vinyl chloride as an essential component, acrylonitrile, (meth) acrylic acid, alkyl (meth) acrylate (having 1 to 1 carbon atoms) 12) At least one unsaturated compound selected from unsaturated compounds such as esters is emulsion-polymerized to form a copolymer, and if necessary, a carboxylic acid-neutralized polyvinyl chloride copolymer and vinyl acetate in an aqueous polyvinyl alcohol solution. Vinyl acetate copolymer, aromatic, aliphatic and alicyclic diisocyanates emulsion-polymerized by adding a catalyst Or polyisocyanates derived therefrom and polyhydric alcohols such as (poly) ethylene glycol, (poly) propylene glycol, trimethylolpropane, pentaerythrit, and sorbitol, or hydroxycarboxylic acids such as bishydroxypropionic acid and hydroxyacetic acid. A urethane emulsion obtained by subjecting at least one or more alcohol compounds selected from the above to a urethane reaction and neutralizing a carboxylic acid as required can be mentioned.

Furthermore, at least one of (meth) acrylic acid (C1-12) alkyl ester and (meth) acrylic acid-2-hydroxyethyl ester or (meth) acrylic acid-2-hydroxypropyl ester as a hydroxyl group component. One of the essential components, (meth) acrylic acid,
Acrylic emulsion in which a carboxylic acid of a copolymer of at least one unsaturated compound selected from unsaturated compounds such as styrene is optionally neutralized, vinylidene fluoride, vinyl fluoride, chlorotrifluoroethylene, tetrafluoroethylene , (Meth) acrylic acid (C 1 -C
12) At least one fluorine-containing unsaturated compound such as a fluoroalkyl ester is used as an essential component, and (meth) acrylic acid (C1-12) alkyl ester, (meth)
A fluorinated copolymer emulsion obtained by neutralizing a carboxylic acid of a copolymer of at least one compound selected from acrylic compounds such as acrylic acid, ethyl vinyl ether, hydroxybutyl vinyl ether and styrene as necessary, styrene and butadiene as essential components A styrene-butadiene copolymer latex obtained by neutralizing a carboxylic acid of a copolymer of at least one unsaturated compound selected from unsaturated compounds such as (meth) acrylic acid and acrylonitrile, if necessary; Examples thereof include a polybutadiene copolymer having a group and, if necessary, a carboxyl group neutralized, a urethane acrylic emulsion having the above-mentioned acrylic emulsion and urethane emulsion having a core-shell structure, a natural latex, and the like.

The particle size of the water-dispersible resin is from 0.01 to 1.
0 μm is preferred. If it is less than 0.01 μm, the viscosity of the water-dispersible resin increases, and it may be limited to use at a low non-volatile content. If it exceeds 1.0 μm, the stability of water dispersion of the water-dispersible resin may be deteriorated. Further, the water-soluble resin or the water-dispersible resin used in the component (A) of the present invention does not substantially contain a hydroxyl group. The phrase "substantially free of hydroxyl groups" means that there is no hydroxyl group for the purpose of crosslinking, and the hydroxyl value is 1 mgKOH /
Less than g is desirable. In the present invention, the purpose of adding the water-dispersible polyisocyanate composition, which is the component (B), to the aqueous dispersion, which is the component (A), is to improve the adhesive force to the substrate, This is because it is not for crosslinking between the water-soluble resin or the water-dispersible resin of the component.

In the present invention, at least one of a stabilizer, a thickener and a filler is used in the aqueous dispersion of the component (A). By using a stabilizer, a thickener, or a filler, it is possible to adjust the viscosity to be easy to use as an adhesive. As a stabilizer, for example, halogenated hydrocarbons such as chlorinated paraffin, ethers such as ethylene glycol monobutyl ether, phthalic acid ester, olefinic acid ester, adipic acid ester, azelaic acid ester, stearic acid ester, benzoic acid ester And at least one compound selected from esters such as phosphoric acid ester, trimellitic acid ester, maleic acid ester and fumaric acid ester, cyclic alkylene carbonates, tertiary amines and the like.

Examples of the thickener include wheat flour, cellulose derivatives, alginate, starch, starch derivatives,
At least one compound selected from polyacrylic acid and the like can be used. Examples of the filler include at least one compound selected from quartz powder, quartz sand, silica, barite, calcium carbonate, chalk, dolomite, talc, wood flour, clay, bentonite, starch, and the like.

In the present invention, in addition to the above-mentioned stabilizer, thickener and filler, the aqueous dispersion of the component (A) contains a leveling agent, an anti-gelling agent, a light stabilizer, an antioxidant, and an improvement in heat resistance. Additives such as agents, plasticizers, lubricants, antistatic agents and auxiliaries can be used. In the present invention, examples of the aliphatic and / or alicyclic diisocyanate used in the component (B) include tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, and hydrogenation. Xylene diisocyanate, 1,4-diisocyanate cyclohexane, and the like. Among them, hexamethylene diisocyanate, isophorone diisocyanate and hydrogenated xylene diisocyanate are easily available industrially and are good.

The polyisocyanate compound obtained from the above aliphatic and / or alicyclic diisocyanate includes:
Buret, isocyanurate, urethane,
It has a structure such as uretdione and allophanate. Among the polyisocyanate compounds, those having a buret structure are excellent in adhesiveness, those having an isocyanurate structure are excellent in weather resistance, those having a urethane structure using an alcohol compound having a long side chain are elastic and Those having excellent extensibility and having a uretdione structure or an allophanate structure are characterized by low viscosity.

The hydrophilic polyisocyanate in the present invention refers to a diisocyanate or a polyisocyanate compound into which a nonionic hydrophilic group comprising ethylene oxide repeating units is introduced. The nonionic hydrophilic group composed of an ethylene oxide repeating unit is a compound containing an ethylene oxide repeating unit in a polyalkylene oxide ether alcohol, and in consideration of water dispersion stability, particularly preferred is polyethylene glycol monomethyl ether. .

The number of ethylene oxide repeating units is
1 to 50, preferably 3 to 50, more preferably 5 to 5
40. When the ethylene oxide repeating unit is 50
If it exceeds, the crystallinity of the hydrophilic polyisocyanate becomes high, and the hydrophilic polyisocyanate tends to be solid, which is not preferable. Also,
If it is less than 1, the dispersibility in water is not sufficient. The amount of the hydrophilic group introduced into the hydrophilic polyisocyanate used in the present invention is 2
５０50% by weight. If it is less than 2% by weight, the effect of lowering the interfacial tension is not sufficient, and the water dispersibility cannot be exhibited, which is not preferable. If it exceeds 50% by weight, the hydrophilicity of the water-dispersible polyisocyanate composition is too high, so that the reaction between the isocyanate groups and water during dispersion in water cannot be suppressed, which is not preferable. The term “introduction” as used in the present invention means to react with an isocyanate group contained in a polyisocyanate compound and incorporate it into a polyisocyanate structure. As an introduction method, an aliphatic or alicyclic diisocyanate, or a polyisocyanate compound obtained therefrom and a polyalkylene oxide ether alcohol may be mixed to carry out a usual urethanization reaction.

The water-dispersible polyisocyanate composition used in the present invention means that the above-mentioned hydrophilic polyisocyanate further contains 0.5% of an ionic surfactant substantially containing no water.
-20% by weight. In addition, here, weight% is a ratio with respect to the said hydrophilic polyisocyanate. The term "substantially free of water" as used in the present invention means that the water contained in the mixed ionic surfactant reacts with the isocyanate group to such an extent that foaming, white turbidity and viscosity increase do not occur. For example, it is 1% or less based on the ionic surfactant.

The ionic surfactant is uniquely determined as anionic or cationic depending on the method of neutralizing the aqueous emulsion. That is, it is necessary to use an anionic surfactant when the aqueous emulsion is neutralized with a base, and to use a cationic surfactant when neutralized with an acid. If the aqueous emulsion is not neutralized, either may be used.

Suitable anionic surfactants are carboxylate type, sulfate type, sulfonate type and phosphate type. Examples thereof include ammonium alkylbenzenesulfonate, sodium alkyldisulfate, sodium alkyldiphenylether disulfonate and sodium dialkylsulfosuccinate. And the like.

Suitable cationic surfactants include quaternary ammonium salts, pyridinium salts and imidazolinium salts, such as alkyltrimethylammonium bromide, alkylpyridinium bromide and imidazolinium laurate. When the amount added is 0.5
If the amount is less than 10% by weight, the effect of water dispersion stability due to the mixing of the ionic surfactant is not exhibited, which is not appropriate. If it exceeds 20% by weight, the dispersed particle diameter becomes too small, and the pot life becomes short, which is not preferable.

The key point of the present invention is to use a nonionic hydrophilic group and an ionic surfactant in combination. When a water-dispersible polyisocyanate composition is dispersed in a water-soluble resin or a water-dispersible resin, by forming a protective film of a nonionic hydrophilic group and an ionic surfactant on the surface of a polyisocyanate oil droplet. In addition, the water dispersion stability of the water dispersible polyisocyanate composition and the long pot life are achieved.

On the other hand, the prior art of Japanese Patent Publication No.
JP-A-7472, JP-A-5-222150, JP-A-6-17004, JP-A-7-48429, JP-A-7-113005, and the like use only a nonionic hydrophilic group. When a nonionic hydrophilic group is introduced into a polyisocyanate compound, the interfacial tension is reduced, which is effective for improving the dispersibility in water. However, since the nonionic hydrophilic group has a low protective power against water, water can easily penetrate into the polyisocyanate, the reaction between water and the isocyanate group starts, and the residual ratio of isocyanate decreases in a short time. Therefore, the effect of adding the water-dispersible polyisocyanate composition to the aqueous dispersion, that is, the improvement of the adhesive strength to the substrate or the like is not exhibited in a short time.

Further, if only an ionic surfactant is mixed with a polyisocyanate compound into which a hydrophilic group has not been introduced, the dispersibility in water is inferior, and water such as the water-dispersible polyisocyanate composition used in the present invention may be used. Dispersion stability cannot be achieved. The technical key of the present invention is that a strong ionic protective film is formed on the polyisocyanate oil droplet surface by using an ionic surfactant in combination with a polyisocyanate having a nonionic hydrophilic group introduced therein. This can prevent water from entering the polyisocyanate oil droplets and protect the isocyanate groups in the polyisocyanate oil droplets from water. This can be achieved by the interaction between the nonionic hydrophilic group introduced into the polyisocyanate and the ionic surfactant.

In a system in which a polyisocyanate having only a nonionic hydrophilic group introduced therein is dispersed in water to which an anionic surfactant has been added, the water containing the anionic surfactant is added when forming polyisocyanate oil droplets. Embraced inside the oil droplets, it is not possible to achieve a long pot life. The isocyanate group content in the water-dispersible polyisocyanate composition used in the present invention is preferably from 3 to 25% by weight in a state where the solid content is substantially 100%. When the amount is less than 3% by weight, the amount of the isocyanate group is too small, so that the effect of adding the water-dispersible polyisocyanate composition to the aqueous dispersion, that is, the improvement of the adhesive strength to the substrate may not be exhibited. The isocyanate group content is uniquely determined from the amount of introduction of the hydrophilic group and the molecular weight. Therefore, when a hydrophilic group necessary to have water dispersibility is introduced, the upper limit is necessarily 25% by weight or less. The state of substantially 100% solids in the present invention refers to a state in which the water-dispersible polyisocyanate composition does not substantially contain a volatile component such as a solvent. A state in which a volatile component is 1% or less in the dispersible polyisocyanate.

The viscosity of the water-dispersible polyisocyanate composition is from 50 to 20,000 at a solid content of substantially 100%.
mPa · s (25 ° C.) is preferred. 20000mPa ・
If it exceeds s, dispersion in water may be difficult. Considering the dispersion in water, the lower the viscosity, the better, but 50 mP
If it is less than a · m, it contains a large amount of an aliphatic and / or alicyclic diisocyanate monomer such as hexamethylene diisocyanate or isophorone diisocyanate, and a protective device or the like may be required during handling.

In the present invention, the weight average molecular weight of the water-dispersible polyisocyanate composition is from 350 to 100.
00 is preferred. When a hydrophilic group necessary for expressing water dispersibility is introduced, the weight average molecular weight necessarily becomes 350 or more. If it exceeds 10,000, the viscosity of the water-dispersible polyisocyanate composition becomes high, and dispersion in water may become difficult.

The water-dispersible polyisocyanate composition used in the present invention has a residual ratio of isocyanate groups of 2 when dispersed in water.
Desirably, it is 50% or more at 0 ° C. for 6 hours. 50%
If it is less than 3, when the aqueous adhesive composition is used, the adhesive strength to the substrate or the like will not be sufficiently exhibited in a short time, that is, the pot life tends to be short. The suppression of the reaction between water and the isocyanate group is achieved by the mutual effect of the ionic surfactant component mixed with the introduced hydrophilic component.

The term "water dispersion" as used in the present invention refers to a state in which the water-dispersible polyisocyanate composition is dispersed in water so that the composition becomes O / W type. It is prepared by mechanically stirring using a stick or a hand mixer. The water-dispersible polyisocyanate composition used in the present invention has good water-dispersion stability. The term “water dispersion stability” as used in the present invention refers to the stability of oil droplets of a water-dispersible polyisocyanate composition dispersed in water by the above method in water. The water-dispersible polyisocyanate composition used in the present invention shows no precipitation even when left at 20 ° C. for 8 hours in a water-dispersed state. This is also achieved by the mutual effect of the ionic surfactant mixed with the introduced hydrophilic group component.

In the present invention, the water-dispersible polyisocyanate composition can be used after adding an organic solvent. Since the water-dispersible polyisocyanate composition mixed with an organic solvent has a low viscosity, the water-dispersibility is improved, and the residual ratio of isocyanate groups at the time of water dispersion is increased, and the pot life is prolonged. . In this case, it is desirable that the organic solvent does not have a functional group that reacts with the isocyanate group. It is desirable that the organic solvent be compatible with the water-dispersible polyisocyanate composition.

Examples of such an organic solvent include ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, methoxypropyl acetate, 3-methoxybutyl acetate, 2-ethylbutyl acetate, and 2-ethylhexyl acetate. ,
Ester compounds such as cyclohexyl acetate, methyl propionate, butyl propionate, butyl butyrate, dioctyl adipate, and diisopropyl glutarate; ether compounds such as diisopropyl ether, dibutyl ether, dioxane, and diethoxyethane; 2-pentanone;
Ketone compounds such as pentanone, 2-hexanone, methyl isobutyl ketone 2-heptanone, 4-heptanone, diisobutyl ketone, isophorone, cyclohexanone, and methylcyclohexanone, and aromatic compounds such as benzene, toluene, xylene, ethylbenzene, butylbenzene, and p-cymene And polyethylene glycol dialkyl ether compounds such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether and triethylene glycol dimethyl ether, and polyethylene glycol dicarboxylate compounds such as diethylene glycol diacetate.

In the present invention, the amount of the organic solvent added to the water-dispersible polyisocyanate composition is preferably from 5 to 50% by weight. If the amount is less than 5% by weight, the merits of mixing an organic solvent, that is, the effects of improving water dispersibility and extending the pot life may not be obtained. If it exceeds 50% by weight, the amount of the volatile organic compound in the water-based adhesive composition of the present invention becomes too large.

The aqueous adhesive composition of the present invention is characterized in that the non-volatile component of the component (B) is
It is 0.5 to 100% by weight. If it is less than 0.5% by weight,
The effect of adding the water-dispersible polyisocyanate composition, that is, the improvement of the adhesive strength to the substrate or the like may not be exhibited, which is not preferable. When the content exceeds 100% by weight, the component (B)
It is not preferable because it is dispersed in a W / O type and the pot life may be significantly shortened.

The water-based adhesive composition of the present invention includes, for example,
The water-dispersible polyisocyanate composition of the component (B) is directly added to the aqueous dispersion of the component (A), or O / W
It can be obtained by adding the water-dispersed component (B) so as to form a mold and stirring with a stick or a hand mixer. The water-based adhesive composition containing the component (A) and the component (B) desirably has a pot life of 6 hours or more at 20 ° C. Pot life is the time when a water-dispersible polyisocyanate composition is added to an aqueous dispersion, and when it is used as an adhesive, a time period during which no apparent decrease in adhesive strength to a substrate, etc. is observed, In other words, it means the time until the adhesive strength immediately after the addition of the water-dispersible polyisocyanate composition becomes less than 70%. If it is less than 6 hours, it cannot always be said that it can sufficiently withstand practical use. This long pot life can be achieved by the interaction of ionic surfactants mixed with the introduced nonionic hydrophilic groups.

In the present invention, the water-dispersible polyisocyanate composition and the aqueous adhesive composition may contain, if necessary, a pigment, a dispersion stabilizer, a viscosity modifier, a leveling agent, a light stabilizer, an antioxidant, UV absorbers, fillers, plasticizers,
A lubricant, a curing acceleration catalyst, and the like can be added. The present invention is an aqueous adhesive composition using a polyisocyanate composition. Accordingly, as described in JP-A-51-42751 or JP-A-57-170972,
Excellent performance in adhesive strength, water resistance and thermal stability can be exhibited.

Since the water-dispersible polyisocyanate composition used in the present invention suppresses the reaction between isocyanate groups and water in a water-dispersed state, the aqueous adhesive composition of the present invention achieves a long pot life. I can do it. Therefore, the same or different types of substrates, especially wood,
Suitable for bonding paper, plastic, metal, cloth, leather, inorganic materials (ceramic, asbestos, pottery, cement, etc.). Further, it exhibits excellent performance as a primer when applying a paint to a substrate.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be further described with reference to examples. In addition, the measuring method, the preparation method, etc. are as follows. The isocyanate group content was determined by back titration with hydrochloric acid after neutralizing the isocyanate group with an excess of amine.

The viscosity was measured at 25 ° C. and 60 rpm with a digital viscometer (DVM-B, Tokyo Keiki Co., Ltd.). The weight average molecular weight was determined using gel permeation chromatography (GPC). When the number average molecular weight is less than 2,000 (column: Tosoh Corp. G1000HXL, G2000HXL, G300)
0HXL, carrier: THF, detection method: parallax refractometer, data processor: Tosoh Corporation CP-8000)
When the number average molecular weight is 2,000 or more (column: Tosoh G
2000HXL, G4000HXL, G5000HX
L, carrier: THF, inspection method: parallax refractometer, data processor: Tosoh Corporation Chromatocoder2
Measured in 1).

The aqueous adhesive composition is prepared by adding a predetermined amount of a water-dispersible polyisocyanate composition to an aqueous dispersion,
It was made by stirring at pm for 10 minutes. The adhesive strength was determined by applying a water-based adhesive to wood (beech wood) so as to have a dry film thickness of 30 μm, and allowing the mixture to stand for 10 minutes after application.
Tensile shear strength was measured when left at 20 ° C. and 65% RH for 7 days under a pressure of m ² for 5 seconds.

The evaluation was as follows: ○: 100 to 75 kg / cm ² or more, Δ: 50 to 75 kg / cm ² , ×: 50 kg / cm
² or less.

[0042]

Synthesis Example 1 (Synthesis of water-dispersible polyisocyanate composition) Methoxy polyethylene glycol (MPG-08
1. Ethylene oxide repeating unit = 15.2 units, manufactured by Nippon Emulsifier Co., Ltd.) and sodium dialkyl sulfosuccinate (Newcol 290M, solid content 70%, manufactured by Nippon Emulsifier Co., Ltd.) at a solid content ratio of 2: 1 And water and solvent were removed by vacuum distillation. Bullet type polyisocyanate (Duranate 24A-
100, manufactured by Asahi Kasei Kogyo Co., Ltd.), and 300 g of a mixture of methoxypolyethylene glycol and sodium dialkylsulfosuccinate obtained above were mixed.
The urethanization reaction was performed at 00 ° C. for 4 hours.

The obtained water-dispersible polyisocyanate composition is a pale yellow liquid and has an isocyanate group content of 1
6.6%, weight average molecular weight 1100, viscosity 4100
mPa · s. The residual ratio of the isocyanate group content when the aqueous dispersion was left at 20 ° C. for 6 hours was 93%.
%Met.

[0044]

Synthesis Example 2 (Synthesis of water-dispersible polyisocyanate composition) Methoxy polyethylene glycol (ethylene oxide repeating units = 5.0) and sodium dialkyl sulfosuccinate (Newcol 290M, solid content 70)
%, Manufactured by Japan Emulsifier Co., Ltd.) at a solid content weight ratio of 3: 1, and water and solvent were removed by distillation under reduced pressure. Buret type polyisocyanate (Duranate 24A-100, manufactured by Asahi Kasei Corporation) 1000 g
And 300 g of a mixture of methoxypolyethylene glycol obtained above and sodium dialkylsulfosuccinate
And a urethanization reaction was carried out at 100 ° C. for 4 hours.

The obtained water-dispersible polyisocyanate composition is a pale yellow liquid and has an isocyanate group content of 1
3.4%, weight average molecular weight 1000, viscosity 5200
mPa · s. When the aqueous dispersion was left at 20 ° C. for 6 hours, the residual ratio of the isocyanate group content was 91%.
%Met.

[0046]

Synthesis Example 3 (Synthesis of water-dispersible polyisocyanate composition: used for comparative example) 1000 g of methoxypolyethylene glycol (MPG-081 buret type polyisocyanate (Duranate 24A-100, manufactured by Asahi Kasei Corporation) and methoxypolyethylene glycol ( M
PG081, manufactured by Nippon Emulsifier), and urethanization reaction was carried out at 100 ° C. for 4 hours.

The obtained water-dispersible polyisocyanate composition is a pale yellow liquid and has an isocyanate group content of 1
8.6%, weight average molecular weight 1000, viscosity 2800
mPa · s. When the aqueous dispersion was left at 20 ° C., it foamed after 3 hours, and the residual ratio of the isocyanate group content after 6 hours was 0%.

[0048]

Example 1 100 g of acrylic latex (styrene / methyl methacrylate / n-butyl acrylate / methacrylic acid copolymer, adjusted to pH 6 with ammonia, solid content 36% by weight, acid value 6 mg KOH / g, Tg 28 ° C.) When,
10 g of the water-dispersible polyisocyanate composition synthesized in Synthesis Example 1 was mixed to obtain an aqueous adhesive composition. Table 1 shows the adhesive strength of the obtained water-based adhesive composition immediately after mixing and the adhesive strength 8 hours after mixing.

[0049]

Example 2 Acrylic resin having a solid content of 42% (styrene / methyl methacrylate / n-butyl acrylate copolymer, adjusted to pH 6 with ammonia, solid content of 30% by weight,
100 g of an aqueous solution having an acid value of 10 mg KOH / g) and Synthesis Example 1
5 g of the water-dispersible polyisocyanate composition synthesized in the above was mixed to obtain a water-based adhesive composition. Table 1 shows the adhesive strength of the obtained water-based adhesive composition immediately after mixing and the adhesive strength 8 hours after mixing.

[0050]

Example 3 100 g of acrylic latex (styrene / methyl methacrylate / n-butyl acrylate / methacrylic acid copolymer, adjusted to pH 6 with ammonia, solid content 36% by weight, acid value 6 mg KOH / g, Tg 28 ° C.) When,
10 g of the water-dispersible polyisocyanate composition synthesized in Synthesis Example 2 was mixed to obtain an aqueous adhesive composition. Table 1 shows the adhesive strength of the obtained water-based adhesive composition immediately after mixing and the adhesive strength 8 hours after mixing.

[0051]

Comparative Example 1 100 g of acrylic latex (styrene / methyl methacrylate / n-butyl acrylate / methacrylic acid copolymer, adjusted to pH 6 with ammonia, solid content 36% by weight, acid value 6 mg KOH / g, Tg 28 ° C.) When,
Water-dispersible polyisocyanate composition 10 obtained in Synthesis Example 3
g was mixed to obtain an aqueous adhesive composition. Table 1 shows the adhesive strength of the obtained water-based adhesive composition immediately after mixing and the adhesive strength 8 hours after mixing.

[0052]

[Table 1]

[0053]

The water-dispersible polyisocyanate composition used in the present invention suppresses the reaction between isocyanate groups and water in a water-dispersed state, so that the aqueous adhesive composition of the present invention has a long pot life. Can be achieved. Therefore, the same or different types of substrates, especially wood, paper,
Plastic, metal, cloth, leather, inorganic materials (ceramic,
Suitable for bonding asbestos, pottery, cement, etc.). Further, it exhibits excellent performance as a primer when applying a paint to a substrate.

Claims (1)

[Claims] 1. An aqueous dispersion comprising a water-soluble resin and / or a water-dispersible resin as a component (A) and an additive containing at least one or more of a stabilizer, a thickener, and a filler.
As the component (B), 2 to 50% by weight of a nonionic hydrophilic group composed of 1 to 50 ethylene oxide repeating units is introduced into (1) an aliphatic and / or alicyclic diisocyanate or a polyisocyanate compound obtained therefrom. Water-dispersible polyisocyanate composition obtained by mixing the obtained hydrophilic polyisocyanate and (2) an ionic surfactant containing substantially no water in an amount of 0.5 to 20% by weight based on (1). Wherein the non-volatile component of the component (B) is in the range of 0.5 to 100% by weight with respect to the non-volatile component of the component (A).
Component (A) and component (B) are each provided separately,
A water-based adhesive composition characterized by being mixed at the time of use.