JPH08170063A - Urethane-based aqueous adhesive composition - Google Patents

Abstract

PURPOSE: To obtain an adhesive composition having excellent adhesivity in normal state as well as high heat-resistance and water-resistance. CONSTITUTION: This urethane-based aqueous adhesive composition is produced by adding (A) a compound having >=2 functional groups reactive with carboxyl group to (B) a composition containing a urethane polymer obtained by preparing a homogeneous mixture of (1) a urethane prepolymer having terminal isocyanate group, composed of (a) a compound having two isocyanate groups in one molecule, (b) a straight-chain diol compound having two hydroxyl groups in one molecule and (c) a dimethylol alkanoic acid compound and produced by reacting the components (a) to (c) at ratios in excess of isocyanate group based on hydroxyl group, (2) a tackifier resin, (3) a neutralizing agent and (4) a hydrophilic organic solvent, dispersing the mixture in water and extending the chain of the urethane prepolymer with (i) a diamino compound having two primary and/or secondary amino groups and/or (ii) water after or during the dispersion of the mixture in water.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a urethane-based water-based adhesive composition.

[0002]

2. Description of the Related Art Urethane-based adhesives exhibit excellent adhesiveness to many adherends and are widely used. on the other hand,
Due to the environmental pollution caused by the organic solvent used for urethane adhesives, the deterioration of the working environment, and the risk of fire, development has recently been actively conducted in the field of urethane adhesives considering the conversion to water. ing.

In the conversion of urethane-based adhesives into water-based adhesives, urethane polymers have generally been dispersed in water using an emulsifier. The water absorption reduced the cohesive strength of the adhesive layer, resulting in extremely poor water resistance.

In order to solve such a problem, a self-dispersing urethane polymer having an ionic or latent ionic functional group or a nonionic hydrophilic group in a molecule is dissolved in water without using an emulsifier. Dispersed self-dispersing aqueous urethane dispersions have been proposed. Japanese Unexamined Patent Publication No. 3-21626 discloses a technique of introducing a carboxyl group into a polyurethane chain. In addition, JP-A-1-69682
The publication discloses a urethane-based water-based adhesive composition obtained by blending a self-emulsifying urethane-based water-based adhesive with an aqueous dispersion of a ketone resin.

However, in spite of such improvement of urethane polymer, these adhesives are not sufficient because the tackifying resin itself blended therein contains a large amount of an emulsifier and is dispersed in water. Water resistance was not obtained. Also,
Since the tackifier resin generally uses a resin having a lower molecular weight and a lower softening point than the urethane polymer, the cohesive force of the adhesive layer in the high temperature region is reduced, and the heat resistance is not sufficiently satisfactory. .

As an attempt to improve the water resistance and heat resistance of a urethane-based water-based adhesive containing a tackifying resin, JP-A-5-230364 discloses that a urethane polymer and a tackifying resin are dispersed in water without an emulsifier, and , At least 3
By using a polyfunctional polyol or polyisocyanate represented by a compound having one or more isocyanate groups or at least three isocyanate-reactive groups,
A method of introducing a crosslinked structure into the water dispersion particles is disclosed. However, in this case, since the crosslinked structure is only inside the particles and the crosslinked structure cannot be formed between the particles, the heat resistance has not been sufficiently improved. In addition, since this polymer system uses a polyfunctional component as a raw material, an increase in abnormal viscosity during production and gelation are regarded as problems.

[0007]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide an adhesive composition having excellent heat resistance, water resistance and adhesiveness under normal conditions.

[0008]

The gist of the present invention is to provide a urethane-based aqueous adhesive composition, [1] (a) a compound having two isocyanate groups in the molecule, and (b) two hydroxyl groups in the molecule. Consisting of three components of a linear diol compound having a number of (c) and a dimethylolalkanoic acid compound (c), and having an isocyanate group at the terminal obtained by reacting with a compound having a larger amount of the isocyanate group than the amount of the hydroxyl group. After a uniform mixture of the urethane prepolymer having [2] tackifying resin, [3] neutralizing agent, and [4] hydrophilic organic solvent is dispersed in water or during dispersion in water, [ i) A composition containing a diamino compound having two primary and / or secondary amino groups, and [ii] a urethane polymer obtained by chain-extending the urethane prepolymer with at least one of water. In A), resides in the place where configured by adding a compound having a functional group reactive to the carboxyl group more than (B).

The compound (a) having two isocyanate groups in the molecule used in the present invention is not particularly limited, and examples thereof include 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,
4,4-trimethylhexamethylene diisocyanate,
2,2,4-trimethylhexamethylene diisocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, dicyclohexylmethane-4,4'-diisocyanate, methylcyclohexyl-2,4-diisocyanate, methylcyclohexyl-2, 6-diisocyanate, xylylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, tetramethyl xylylene diisocyanate,
Aliphatic diisocyanates such as transcyclohexane-1,4-diisocyanate; 2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate,
Diphenylmethane-4,4'-diisocyanate, 1,
Examples thereof include aromatic diisocyanates such as 5-naphthene diisocyanate, tolidine diisocyanate, tetraalkyldiphenylmethane diisocyanate, and paraphenylene diisocyanate. These compounds having two isocyanate groups in the molecule may be used alone or as a mixture of two or more kinds.

The linear diol compound having two hydroxyl groups in the molecule (b) used in the present invention is not particularly limited, and examples thereof include polyethylene glycol and polypropylene glycol having a molecular weight of 500 to 10,000. Polyether polyols; dicarboxylic acids such as adipic acid, sebacic acid, itaconic acid, maleic anhydride, terephthalic acid, isophthalic acid and ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, 1,6-hexanediol , Polyester diols obtained from glycols such as tripropylene glycol and neopentyl glycol; polycaprolactone diol, polytetramethylene ether diol, polybutadiene diol, hydrogenated polybutadiene diol, polycarbonate di Lumpur, polythioether diol,
Examples thereof include polyacrylic ester diol. These compounds having two hydroxyl groups in the molecule may be used alone or as a mixture of two or more kinds.

The molecular weight of the linear diol compound (b) having two hydroxyl groups in the molecule is preferably 500 to 10,000 when used alone. If the molecular weight is less than 500, the adhesive film obtained will be too hard and will be 10,000
When it exceeds 0, the viscosity of the obtained prepolymer becomes too high, and the dispersion operation during water dispersion becomes difficult. The molecular weight is preferably 800 to 7,000, more preferably 1
It is 000-5000.

In the present invention, the above-mentioned (b) linear diol compound having two hydroxyl groups in the molecule has the above-mentioned molecular weight of 5
If necessary, a low molecular weight diol compound having a molecular weight of less than 500, for example, ethylene glycol, 1,4-butanediol, 1,6-hexanediol or the like is mixed with 100 to 10,000 to obtain a molecular weight of 500 to 1 It can also be used in the same manner as a linear diol compound having two hydroxyl groups in the molecule.

Since the linear diol compound (b) having two hydroxyl groups in the molecule has the above-mentioned properties, the kind of compound used depending on the purpose of use and the specific application of the product. Can be selected at any time, and the physical properties required for the adhesive such as hardness and adhesiveness can be arbitrarily designed.

The dimethylolalkanoic acid compound (c) used in the present invention is a compound having a structure represented by the following formula, for example, dimethylolpropionic acid, dimethylolbutyric acid, dimethylolvaleric acid, dimethylol, etc. Is mentioned.

[0015]

Embedded image

In the formula, R represents an alkyl group having 1 to 20 carbon atoms.

The addition amount of the above-mentioned (c) dimethylolalkanoic acid compound is preferably about 0.1 to 2.0 mmol per 1 g of the urethane prepolymer obtained. The amount added is
If it is less than 0.1 mmol, the hydrophilicity of the resulting urethane prepolymer is insufficient, and it is difficult to disperse it in water stably. On the other hand, when it exceeds 2.0 millimoles, the hydrophilicity of the urethane prepolymer obtained becomes too large, and the water resistance of the obtained adhesive decreases.

In the present invention, if necessary, the molecular weight is 5
Low molecular weight diol compounds of less than 00 can be used. Examples of such a low molecular weight diol include ethylene glycol, 1,4-butanediol and 1,6-
Hexanediol and the like can be mentioned.

In the present invention, the above (a),
The urethane prepolymer having an isocyanate group at the terminal is synthesized by reacting three components (b) and (c) as essential components with a compounding amount of the isocyanate group larger than the amount of the hydroxyl group described above. The equivalent ratio represented by (equivalent of isocyanate group in component (a)) / [equivalent of hydroxyl group in component (b) + equivalent of hydroxyl group in component (c)] is in the range of 1.1 to 2.0. It is desirable that the compounding ratio be such that

The polymerization reaction of the urethane prepolymer [1] is carried out within the temperature range of 50 to 150 ° C. As the polymerization reaction method, either bulk polymerization or solution polymerization may be used. When the reaction is carried out by solution polymerization,
The solvent used is preferably, for example, a solvent which is inactive to isocyanate groups such as acetone, methyl ethyl ketone, tetrahydrofuran, and methyl acetate, has a high affinity with water, and has a boiling point of 100 ° C. or lower. Boiling point is 10
When a solvent having a temperature higher than 0 ° C. is used, the step of removing only the solvent from the aqueous dispersion outside the system becomes difficult.

Tackifying resin used in the present invention [2]
Is added mainly for improving the adhesion of the obtained adhesive to an adherend, and specifically, is described in Polyurethane Resin Handbook (September 5, 1987, published by Nikkan Kogyo Shimbun) 441. ~ Gum rosin, tall oil rosin, wood rosin, polymerized rosin, hydrogenated rosin, disproportionated rosin, rosin ester, hydrogenated rosin ester, disproportionated rosin ester, rosin-modified phenolic resin, etc. Rosin resin; terpene resin, phenol resin, terpene phenol resin, xylene resin, ketone resin, aliphatic petroleum resin, aromatic petroleum resin, alicyclic petroleum resin, coumarone resin, styrene resin, etc. However, it is not particularly limited as long as it is used as an adhesive.

In the above tackifying resin [2], xylene resin obtained from metaxylene and formaldehyde, xylene resin modified with phenols such as alkyl-substituted bifunctional phenols such as phenol and para-t-butylphenol, cyclohexanone. A ketone resin obtained from formaldehyde and a ketone such as methyl ethyl ketone, a novolac type phenol resin obtained from a formaldehyde and an alkyl-substituted bifunctional phenol such as para-t-butylphenol, and formaldehyde, and an alkylphenol resin are the present invention. Is particularly preferably used in. The tackifying resin [2] may be used alone or as a mixture of two or more kinds. The softening point of the tackifier [2] used is preferably in the range of 60 to 160 ° C.

The addition amount of the tackifying resin [2] is preferably 5 to 200 parts by weight with respect to 100 parts by weight of the urethane polymer. If the addition amount is less than 5 parts by weight, the effect of improving the adhesiveness cannot be sufficiently obtained, and if it exceeds 200 parts by weight, the cohesive force at high temperature is extremely decreased, and the decrease in heat resistance is unavoidable. However, the ratio of the hydrophobic component in the adhesive aqueous dispersion becomes too large, and a stable aqueous dispersion cannot be obtained. It is preferably 5 to 150 parts by weight, and more preferably 10 to 100 parts by weight.

The neutralizing agent [3] used in the present invention is
(C) A compound which is mixed for the purpose of improving the water resistance of the resulting adhesive by completely or partially converting a carboxyl group introduced into a urethane prepolymer by a dimethylolalkanoic acid compound into a carboxylate group. However, for example, ammonia or a volatile tertiary amine such as trimethylamine or triethylamine is preferably used. This is because these neutralizing agents can be removed by scattering during drying, so that the water resistance of the film does not decrease.

Alkali metal salts and non-volatile amines also act as the above-mentioned neutralizing agent, but these substances cannot be scattered and removed outside the system when the adhesive is dried,
Since the water resistance of the dry film of the adhesive may be reduced, care must be taken when using it.

The addition amount of the neutralizing agent [3] is preferably equal to or less than the neutralization equivalent of the dimethylolalkanoic acid compound (c) used. When the addition amount is equal to or more than the neutralization equivalent, the pH value of the adhesive water dispersion is largely biased to the alkali side, and the stability of the adhesive water dispersion is hindered.

Hydrophilic organic solvent used in the present invention [4]
Is preferably a solvent which is inactive to isocyanate groups, has a high affinity for water, and has a boiling point of 100 ° C. or less. Examples of the hydrophilic organic solvent include acetone, methyl ethyl ketone, tetrahydrofuran, methyl acetate and the like.

In the present invention, the above [1] urethane prepolymer having an isocyanate group at the terminal, [2] tackifying resin, [3] neutralizing agent, and [4] hydrophilic organic solvent are uniformly mixed. Disperse the mixture in water. At this time, it is preferable that the viscosity of the mixture of the above four components is adjusted by the addition amount of the hydrophilic organic solvent [4] so as to be 50,000 cps or less. Viscosity of the above mixture is 5000
If it exceeds 0 cps, it may not be uniformly dispersed and may aggregate. Therefore, the mixture of the above four components is
It is necessary to thoroughly mix and make a homogeneous system before dispersing in water. When the mixture is a heterogeneous system, it may aggregate when dispersed in water, or the stability of the resulting water-based adhesive composition may decrease, causing sedimentation. In such a case, the addition amount of the hydrophilic organic solvent is appropriately adjusted so that the mixture becomes a homogeneous system.

As a method for dispersing the above-mentioned four-component mixture in water, a method of gradually adding water to the above-mentioned four-component mixture while applying a mechanical shearing force such as a homomixer or a disper, or the action of the above-mentioned shearing force A batch method such as a method of gradually adding the above-mentioned four-component mixture to the water, a method of quantitatively supplying the above-mentioned four-component mixture and water to various continuous emulsifying dispersers, and the like Is mentioned.

As described above, [1] a urethane prepolymer having an isocyanate group at the terminal, [2] a tackifying resin, [3] a neutralizing agent, and [4] a hydrophilic organic solvent were uniformly mixed. The mixture is dispersed in water. Simultaneously with or after the dispersion step, [i] a diamino compound having two primary and / or secondary amino groups and [ii] water. By at least one of
Chain extension of the urethane prepolymer.

The diamino compound [i] having two primary and / or secondary amino groups used as a chain extender for the urethane prepolymer is not particularly limited, and examples thereof include ethylenediamine and 1,4-butane. Diamine, 1,
6-hexamethylenediamine, 3-aminomethyl-3,
Examples include 5,5-trimethylcyclohexylamine, 1,3-bis (aminomethyl) cyclohexane, xylylenediamine, piperazine and the like.

The addition amount of the diamino compound [i] having two primary and / or secondary amino groups is preferably equal to or less than the equivalent amount of the isocyanate group serving as the origin of chain extension in the urethane prepolymer. If the above-mentioned addition amount exceeds the equivalent amount of the isocyanate group, the molecular weight of the chain-extended urethane polymer becomes small and the cohesive force of the adhesive decreases. Further, since the diamino compound [i] having two primary and / or secondary amino groups has a greater nucleophilicity for isocyanate than water existing as a dispersion medium, it has priority over water existing as a dispersion medium. The reaction proceeds.

A composition (A) containing a urethane polymer is produced as described above. When a urethane prepolymer [1] having an isocyanate group at the terminal is synthesized, a tackifying resin [2] or the like is mixed, or The hydrophilic organic solvent [4], which is added as necessary when water is dispersed in the above mixture, is dispersed in water and then removed outside the water dispersion system by means of heating, reduced pressure or reduced pressure heating. be able to. If a large amount of these hydrophilic organic solvents [4] remain in the water dispersion, the solvent resistance and heat resistance of the dry film of the adhesive are lowered, and the working environment during the bonding work is deteriorated. .

The urethane-based aqueous adhesive composition of the present invention comprises
The composition (A) containing the urethane polymer is added with the compound (B) having two or more functional groups having a reaction activity with respect to a carboxyl group. The compound (B) having two or more functional groups reactive with a carboxyl group in the molecule is, for example, various metals such as isocyanate type, melamine type, aziridine type, epoxy type, oxazoline type and carbodiimide type metals. A chelate type crosslinking agent can be used. In particular, aziridine type, epoxy type,
Isocyanate type, oxazoline type, carbodiimide type, and more preferably, aziridine type, epoxy type and carbodiimide type, which are dissolved or dispersed in water, are preferable. The compound (B) having two or more functional groups having a reactive activity with respect to the carboxyl group may be used alone or in a mixture of two or more.

The aziridine-based crosslinking agent is not particularly limited, and examples thereof include trimethylolpropane-tri-3-.
[(1-aziridinyl) propionate], diphenylmethane-bis-4,4′-N, N′-diethyleneurea, tetramethylolmethane-tri-β-aziridinylpropionate, N, N′-toluene-2, 4-bis-
(1-aziridinecarboxamide), N, N'-hexamethylene-1,6-bis (1-aziridinecarboxamide) and the like.

The epoxy-based cross-linking agent is not particularly limited, and examples thereof include polypropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, resorcin diglycidyl ether, sorbitol polyglycidyl ether. , Sorbitan polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, 1,6-hexanediol diglycidyl ether, and the like. At this time, various known amine-based catalysts such as triethylenediamine, tetramethylethylenediamine, pyridine, and hexamethylenetetramine may be used to enhance the reaction activity of the epoxy-based crosslinking agent.

The above-mentioned carbodiimide type crosslinking agent is represented by the general formula R ¹ -N = C = N-R ² . In the formula, R ¹ and R ² represent hydrogen or an alkyl group, and examples of the alkyl group include a propyl group, a cyclohexyl group, a p-toluoyl group and the like.

The urethane-based water-based adhesive composition of the present invention comprises
In addition to the above, if necessary, a plasticizer, a filler, a thickener,
A defoaming agent, a fungicide, a rust preventive, etc. may be added.

The urethane-based water-based adhesive composition containing the tackifying resin obtained as described above is adjusted to an appropriate viscosity and concentration, and adhered to various adherends by a method such as coating, spraying or impregnating. Can be used for.

[0040]

[Function] The urethane-based water-based adhesive composition of the present invention is
[1] consists of three components: (a) a compound having two isocyanate groups in the molecule, (b) a linear diol compound having two hydroxyl groups in the molecule, and (c) a dimethylolalkanoic acid compound. A urethane prepolymer having an isocyanate group at the end obtained by reacting with a compound having an isocyanate group content higher than the hydroxyl group content, [2] tackifying resin, [3] neutralizing agent, and [4] hydrophilicity At least one of [i] a diamino compound having two primary and / or secondary amino groups and [ii] water after dispersion of a uniform mixture of organic solvents in water or during dispersion in water. 1
By using a linear self-dispersing urethane polymer obtained by chain extension of the above urethane prepolymer, there is no problem of viscosity increase or gelation during the production of an adhesive, and For the first time when used as an agent, the crosslinking agent having reactivity with the carboxyl group in the urethane polymer, the crosslinking reaction between particles of the adhesive proceeds, the water absorption of the coated film becomes small, and,
Since the decrease in cohesive force at high temperatures is small, a coating film having excellent water resistance and heat resistance can be formed.

[0041]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

Example 1 Polypropylene glycol diol (manufactured by NOF CORPORATION, trade name: Nissan Uniol D-2000, OH value: 5)
8, number average molecular weight; 2000) 100 parts by weight, 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate (manufactured by Huls, trade name: Bestanto IPDI) 31.2 parts by weight, and dimethylolpropionic acid 5 Methyl ethyl ketone 34.2 parts by weight (6 parts by weight, manufactured by Trimet Technical Products, trade name: DMPA, (isocyanate group / hydroxyl group) equivalent ratio = 1.5).
The mixed solution consisting of parts by weight is subjected to boiling point polymerization under stirring,
The content of the isocyanate group is 2.3% by weight or less, and 57.0 parts by weight of methyl ethyl ketone for adjusting the viscosity, 4.2 parts by weight of triethylamine as a neutralizing agent, a ketone resin (trade name: manufactured by Hitachi Chemical Co., Ltd .: Hirac 111, softening point 110 ° C, 50% by weight methyl ethyl ketone solution) 8
2 parts by weight (41 parts by weight solids) were added.

Then, 480 parts by weight of water was added to the above reaction mixture under vigorous stirring at room temperature, and immediately after that, 28.0 parts by weight of a 10% by weight ethylenediamine aqueous solution (2.8 parts by weight of solid content) were added. After further stirring for 1 hour at room temperature, the pressure was reduced and the solvent was removed. The solid content of the thus obtained aqueous dispersion was 35% by weight.

An aqueous dispersion of an aziridine-based cross-linking agent (manufactured by Nippon Shokubai Co., Ltd., trade name:
Chemitite DZ22-E, solid content 25% by weight) 21.8
By weight (solid content 5.5 parts by weight) was added to obtain an aqueous adhesive composition.

Example 2 In place of the polypropylene glycol diol of Example 1, 100 parts by weight of polyester diol (manufactured by Nippon Polyurethane Company, trade name: Nipporan N-165, OH value; 58, number average molecular weight; 2000) was used. A urethane polymer aqueous dispersion having a solid content of 35% by weight was obtained in the same manner as in Example 1 except for the above. Then, 5.5 parts by weight of an aziridine-based crosslinking agent (manufactured by Nippon Shokubai Co., Ltd., trade name: Chemitite DZ22-E, trade name: TAZO) was added, and an aqueous adhesive was prepared in the same manner as in Example 1. A composition was obtained.

Example 3 A novolak alkylphenol resin (made by Hitachi Chemical Co., Ltd., trade name: Hitanol 150) was used in place of the ketone resin of Example 1.
1, a softening point of 95 ° C., and a 82 wt part of a 50 wt% methyl ethyl ketone solution) were used to obtain a urethane polymer aqueous dispersion having a solid content of 35 wt% in the same manner as in Example 1. Then, a crosslinking agent was added in the same manner as in Example 1 to obtain an aqueous adhesive composition.

Example 4 Instead of the polypropylene glycol diol of Example 1, a polycarbonate diol (manufactured by Nippon Polyurethane Company, trade name: Nipporan N-982N, OH value; 57,
Number average molecular weight; 2000) 100 parts by weight, dimethylolpropionic acid 5.6 parts by weight to 5.5 parts by weight, xylene resin (trade name: Nikanol HP100, manufactured by Mitsubishi Gas Chemical Co., Inc.) instead of the ketone resin. A urethane polymer aqueous dispersion having a solid content of 35% by weight was obtained in the same manner as in Example 1, except that 82 parts by weight of 115% at 50% by weight methyl ethyl ketone solution) was used. Then, a crosslinking agent was added in the same manner as in Example 1 to obtain an aqueous adhesive composition.

Example 5 A urethane polymer water having a solid content of 35% by weight was prepared in the same manner as in Example 1 except that 82 parts by weight of the novolac alkylphenol resin used in Example 3 was used in place of the ketone resin of Example 1. A dispersion was obtained. Then, instead of the aqueous dispersion of the aziridine crosslinking agent, an epoxy crosslinking agent (manufactured by Nagase Sangyo Co., Ltd., trade name: Denacol EX-810, solid content 10)
(0% by weight) was added to obtain an aqueous adhesive composition in the same manner as in Example 1.

Example 6 Instead of the polypropylene glycol diol of Example 1, polycaprolactone diol (manufactured by Daicel Chemical Industries, Ltd., trade name: Praxel L220AL, OH value; 58,
Number average molecular weight; 2000) Solid content 35 in the same manner as in Example 1 except that 100 parts by weight of the xylene resin used in Example 4 was used instead of the ketone resin.
A wt% urethane polymer water dispersion was obtained. Then, in place of the aqueous dispersion of the aziridine crosslinking agent, a carbodiimide crosslinking agent (manufactured by Union Carbide Co., trade name: Yucarlink XL-25SE, solid content 50% by weight) 11.0 parts by weight (solid content 5.5% by weight) Part) was added and an aqueous adhesive composition was obtained in the same manner as in Example 1.

Example 7 A urethane polymer water having a solid content of 35% by weight was prepared in the same manner as in Example 1 except that 82 parts by weight of the novolak alkylphenol resin used in Example 3 was used in place of the ketone resin of Example 1. A dispersion was obtained. Then, an aqueous dispersion of an aziridine-based crosslinking agent (manufactured by Nippon Shokubai Co., Ltd., trade name: Chemitite D
Z22-E, solid content 25% by weight) 21.8% by weight (solid content 5.5 parts by weight) and epoxy cross-linking agent (Nagase Sangyo Co., Ltd., trade name: Denacol EX-614B, solid content 100).
% By weight) and 0.6 part by weight of triethylenediamine (Wako Pure Chemical Industries, Ltd., reagent, 50% by weight aqueous solution) (solid content: 0.3 parts by weight) were further added in the same manner as in Example 1. An aqueous adhesive composition was obtained.

Example 8 A urethane polymer water having a solid content of 35% by weight was prepared in the same manner as in Example 1 except that 82 parts by weight of the novolak alkylphenol resin used in Example 3 was used in place of the ketone resin of Example 1. A dispersion was obtained. Then, an aqueous dispersion of an aziridine-based crosslinking agent (manufactured by Nippon Shokubai Co., Ltd., trade name: Chemitite D
Z22-E, solid content 25% by weight) 21.8% by weight (solid content 5.5 parts by weight) and epoxy cross-linking agent (manufactured by Nagase Sangyo Co., Ltd., trade name: Denacol EX-313, solid content 100% by weight). 5.5 parts by weight and further 0.6 parts by weight of triethylenediamine (Wako Pure Chemical Industries, Ltd., reagent, 50% by weight aqueous solution) (0.3 parts by weight of solid content) were added, and water-based adhesion was carried out in the same manner as in Example 1. An agent composition was obtained.

Example 9 A urethane polymer water having a solid content of 35% by weight was prepared in the same manner as in Example 1 except that 82 parts by weight of the novolak alkylphenol resin used in Example 3 was used in place of the ketone resin of Example 1. A dispersion was obtained. Then, an aqueous dispersion of an aziridine-based crosslinking agent (manufactured by Nippon Shokubai Co., Ltd., trade name: Chemitite D
Z22-E, solid content 25% by weight) 21.8% by weight (solid content 5.5 parts by weight), and carbodiimide-based cross-linking agent (manufactured by Union Carbide Co., trade name: Yukerlink XL-25S).
E, solid content 50% by weight) 11.0 parts by weight (solid content 5.5
(Parts by weight) was added to obtain an aqueous adhesive composition in the same manner as in Example 1.

Comparative Example 1 The same as Example 1 except that the ketone resin of Example 1 was replaced by 82 parts by weight of the novolak alkylphenol resin used in Examples 3 and 5, and no crosslinking agent was used. By the method, a urethane polymer aqueous dispersion having a solid content of 35% by weight was obtained. This aqueous dispersion was directly used as an aqueous adhesive composition.

Comparative Example 2 A urethane polymer aqueous dispersion having a solid content of 35% by weight was obtained in the same manner as in Example 1 except that 82 parts by weight of the ketone resin of Example 1 was not used. Then, 5.5 parts by weight of the aziridine-based cross-linking agent was added in an amount of 4.3 parts by weight to obtain an aqueous adhesive composition in the same manner as in Example 1.

Comparative Example 3 A solid content of 35% by weight was obtained in the same manner as in Comparative Example 2 except that the aziridine-based crosslinking agent in Comparative Example 2 was not used.
A urethane polymer aqueous dispersion of was obtained. This aqueous dispersion was directly used as an aqueous adhesive composition.

Comparative Example 4 A novolac alkylphenol resin (manufactured by Hitachi Chemical Co., Ltd.) was vigorously stirred in 110 parts by weight of an aqueous solution in which 3.0 parts by weight of a nonionic emulsifier (manufactured by Nippon Emulsifier Co., Ltd., trade name: Newcol 210) was dissolved. Name: Hitanol 150
1. Softening point 95 ° C.) and 140 parts by weight of a mixed solution of methyl ethyl ketone and the like are added dropwise at room temperature to disperse, and then 40
After stirring at ℃, depressurize to remove the solvent, solid content 35
A wt% novolak alkylphenol resin aqueous dispersion was obtained.

117 parts by weight of the above novolak alkylphenol resin aqueous dispersion (41 parts by weight of solid content) was used in Comparative Example 2
A urethane polymer aqueous dispersion obtained in the same manner as in (1) was added to obtain a mixed aqueous dispersion having a solid content of 35% by weight. (However, the amount of the aziridine-based crosslinking agent added is from 4.3 parts by weight to 5.
Replace with 5 parts by weight. )

Comparative Example 5 32.3 parts by weight of 3-isocyanate methyl-3,5,5-trimethylcyclohexylisocyanate of Example 1 was changed to 42.3 parts by weight, and polypropylene glycol diol was replaced with polypropylene glycol triol (Asahi Glass Co., Ltd.). Product name: Exenol 3030, OH number: 5
6, number average molecular weight; 3000, average number of functional groups; 3) 10
0 parts by weight, 5.6 parts by weight of dimethylolpropionic acid to 6.0 parts by weight, and 4.2 parts by weight of triethylamine to 4.2 parts by weight.
6 parts by weight, 2.8 parts by weight of ethylenediamine was changed to 5.7 parts by weight, 82 parts by weight of ketone resin was changed to 87.8 parts by weight, and the boiling point polymerization was performed until the residual isocyanate group became 4.3% by weight or less. A urethane polymer aqueous dispersion having a solid content of 35% by weight was obtained in the same manner as in Example 1 except that the steps were performed. This aqueous dispersion was directly used as an aqueous adhesive composition.

Comparative Example 6 The procedure of Example 1 was repeated except that the ketone resin of Example 1 was replaced with 575 parts by weight of a 50% by weight solution of the methyl ethyl ketone of novolak alkylphenol resin used in Examples 3 and 5 (288 parts by weight of solid content). By the same method as in Example 1, a urethane polymer aqueous dispersion having a solid content of 35% by weight was obtained. Then, 21.8 parts by weight of the aziridine crosslinking agent was changed to 51.6 parts by weight (solid content 12.9 parts by weight), and the crosslinking agent was added in the same manner as in Example 1 to obtain an aqueous adhesive composition.

Comparative Example 7 3-isocyanatomethyl-3,5,5, -of Example 1
31.2 parts by weight of trimethylcyclohexyl isocyanate was added to 42.3 parts by weight, dimethylolpropionic acid and triethylamine were not used, and 4.0 parts by weight of 1,4-butanediol was newly used.
By replacing 5.7 parts by weight with no further ketone,
3. Boiling point polymerization was carried out until the residual isocyanate group was 4.3% by weight or less, and nonionic emulsifier was added to water (manufactured by Nippon Emulsifier Co., Ltd., trade name: Newcol 210).
A urethane polymer aqueous dispersion having a solid content of 35% by weight was obtained in the same manner as in Example 1 except that 4 parts by weight was added. 125.4 parts by weight of the novolak alkylphenol resin aqueous dispersion used in Comparative Example 4 (solid content: 43.9 parts by weight) was added to this aqueous dispersion to prepare an aqueous adhesive composition as it was.

The urethane-based water-based adhesive compositions obtained in Examples 1 to 9 and Comparative Examples 1 to 7 were subjected to the following methods to show the normal-state adhesive strength, water-resistant adhesive strength, heat-resistant adhesive strength, and 80 ° C. peel adhesive strength. Tested in. The test results are shown in Table 1, Table 2 and Table 3.

(1) Normal-state adhesive strength The urethane-based water-based adhesive composition thus obtained was applied to a canvas and a cold-rolled steel plate (width 25 mm, length 125 mm, thickness 2 mm) by brushing to apply the amount of coating and solid content to the canvas. 100 (g /
m ² ), the same 40 (g / m ² ) was applied to the cold-rolled steel sheet, dried for 4 minutes in a blast drying oven at 80 ° C., and the two were roll-pressed at a pressure of 60 kg / 25 mm to give a test piece. Created. After curing the test pieces at 23 ° C for 1 week, 2
A 90 degree peel test was performed at a pulling speed of 50 mm / min at 3 ° C.

(2) Water-resistant adhesive strength After immersing the test piece of the above item in warm water of 40 ° C. for 12 hours,
A 90 degree peel test was performed at 23 ° C. by wiping off water at a pulling speed of 50 mm / min.

(3) Adhesive strength at high temperature The resulting urethane-based aqueous adhesive composition was applied to a 25 mm wide canvas cloth by brush coating to give a coating amount of 100 (g / g) solids.
m ² ), and dried at room temperature for 48 hours. The above adhesives were adhered to each other and hot pressed at a pressure of 10 kg / cm ² for 5 minutes at 80 ° C. to prepare a 25 mm × 25 mm test piece. Attach a weight of 1 kg to the canvas on one side of the above test piece, and
Perform a 180 degree peel creep test in an atmosphere of 00 ° C,
The time until the weight fell was measured.

(4) Peeling Adhesion at 80 ° C. Evaluation of Normal Adhesion A test piece similar to the test piece was left under an atmosphere of 80 ° C. for 5 minutes, and then 50 mm under the same atmosphere.
A 90-degree peel test was performed at a pulling speed of / min.

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[Table 1]

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[Table 2]

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[Table 3]

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EFFECT OF THE INVENTION Since the urethane-based water-based adhesive composition of the present invention has the above-mentioned constitution, it does not cause a large increase in viscosity or gelation during the production of the adhesive and is used as an adhesive. For the first time, the crosslinking reaction between the particles of the adhesive proceeds due to the crosslinking agent that is reactive with the carboxyl group in the urethane polymer, the water absorption of the coated film becomes small, and coagulation at high temperature occurs. Since the decrease in power is small,
A coating film having excellent water resistance and heat resistance can be formed.

Claims (1)

[Claims] 1. [1] (a) A compound having two isocyanate groups in the molecule, (b) a linear diol compound having two hydroxyl groups in the molecule, and (c) a dimethylolalkanoic acid compound. A urethane prepolymer having an isocyanate group at the terminal, which is obtained by reacting with a compounding amount of the above-mentioned hydroxyl groups which is larger than that of the above-mentioned hydroxyl groups, [2] a tackifying resin, [3] a neutralizing agent, And [4] a diorgano compound having two primary amino groups and / or secondary amino groups, after a uniform mixture of the hydrophilic organic solvent is dispersed in water or while being dispersed in water. And (ii) a composition (A) containing a urethane polymer obtained by chain-extending the urethane prepolymer with at least one of water, and a functional group having a reactive activity for a carboxyl group is added to the composition (A). Urethane aqueous adhesive composition characterized by comprising adding a compound having more than a (B).