JPH1025325A - Urethane emulsion and aqueous adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a urethane emulsion not only excellent in water resistance but also excellent in adhesivity to highly uneven adherends by dispersing a specific urethane (pre)polymer and an adhesivity-imparting resin in water. SOLUTION: This urethane elusion is produced by dispersing (A) a self- emulsive urethane polymer and/or a self-emulsifiable urethane prepolymer and (B) an adhesivity-imparting resin in water. The urethane polymer and/or the urethane prepolymer are obtained by reacting (i) a polyisocyanate with (ii) a compound having at least one kind of hydrophilic group selected from an ionic group, a nonionic group and a latent ionic group in the molecular and further having two or more active hydrogen atoms capable of reacting with the isocyanate group and (iii) a compound having a number-average mol.wt. of 6000-50000 and having two or more active hydrogen atoms capable of reacting with the isocyanate group. The component (i) is preferably 1,4-tetramethylene diisocyanate, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a urethane emulsion which can be used for a pressure-sensitive adhesive or an adhesive, a paint or a coating agent, and an aqueous adhesive using the urethane emulsion. The present invention relates to a urethane emulsion and an aqueous adhesive which not only have excellent adhesion but also excellent adhesion to inorganic materials and porous materials.

[0002]

2. Description of the Related Art Solvent-based pressure-sensitive adhesives and adhesives using organic solvents have excellent adhesion and adhesion to an adherend.
And because it is suitable for many uses, it is widely used. However, there are problems such as air pollution due to the volatilization of the organic solvent used, deterioration of the working environment, and the danger of fire. Therefore, in recent years, conversion to pressure-sensitive adhesives and adhesives using water as the solvent has been advanced. Have been.

[0003] However, in general, water-based adhesives have a disadvantage that they have lower water resistance than solvent-based adhesives.
To solve this problem, Japanese Unexamined Patent Publication No. Hei.
Japanese Patent Application Laid-Open Publication No. H11-163,086 discloses a method for producing a self-emulsifiable urethane-based aqueous dispersion obtained by introducing a carboxyl group into a polyurethane chain. Here, a carboxyl group-containing urethane prepolymer is reacted with a basic organic compound such as dimethylethanolamine and an elongating agent such as water and / or diamines in the presence of a solvent and water, and the solvent is removed under reduced pressure. Thus, a self-emulsifiable urethane-based aqueous dispersion is obtained.

However, in the urethane-based aqueous dispersion obtained by the method described in the above-mentioned prior art, since a large number of polar groups such as urethane bonds and urea are present, a three-dimensional structural particle dispersion in which dispersed particles are connected to each other is used. Has become. As a result, since the particles are relatively hard, there is a disadvantage that adhesion and adhesion to materials having large surface irregularities such as inorganic materials and porous materials are low.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide not only excellent water resistance but also adhesion and adhesion to a wide range of adherends such as metals and plastics. An object of the present invention is to provide a urethane emulsion excellent in adhesiveness and adhesiveness to materials having large surface irregularities such as inorganic materials, metals and porous materials, and an aqueous adhesive using the urethane emulsion.

[0006]

According to the first aspect of the present invention, there is provided a urethane emulsion comprising at least one of a polyisocyanate compound (A), an ionic group, a nonionic group and a potential ionic group in a molecule. A compound (B) having at least two kinds of hydrophilic groups and having two or more active hydrogens capable of reacting with an isocyanate group, and having a number average molecular weight of 6000
A self-emulsifying urethane polymer and / or urethane prepolymer comprising a compound (C) having two or more active hydrogens capable of reacting with an isocyanate group, and a tackifier resin in water. It is a urethane emulsion obtained by dispersing.

A water-based adhesive according to a second aspect of the present invention is characterized by containing the urethane emulsion according to the first aspect of the present invention as a main component. Less than,
The details of the urethane emulsion and the aqueous adhesive of the present invention will be described.

[0008] Urethane polymer and urethane prepolymer
-The self-emulsifying urethane polymer and urethane prepolymer used in the present invention are products obtained by reacting the polyisocyanate compound (A), the compound (B), and the compound (C), If necessary, the molecular weight can be increased by a chain extender before, during or after aqueous dispersion.

The polyisocyanate compound (A) is not particularly limited, and an appropriate polyisocyanate compound such as an aliphatic diisocyanate, an aromatic diisocyanate or a triisocyanate can be used.

Examples of the aliphatic diisocyanates include 1,4-tetramethylene diisocyanate, 1,6
-Hexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-
Trimethylhexamethylene diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, dicyclohexylmethane-4,4
'-Diisocyanate, methylcyclohexyl-2,4
-Diisocyanate, methylcyclohexyl-2,6-
Diisocyanate, xylylene diisocyanate, 1,
Examples thereof include 3-bis (isocyanatomethyl) cyclohexane, tetramethylxylylene diisocyanate, and transcyclohexane-1,4-diisocyanate.

The aromatic diisocyanates include, for example, 2,4-toluylene diisocyanate,
Examples thereof include 2,6-toluylene diisocyanate, diphenylmethane-4,4'-diisocyanate, 1,5-naphthene diisocyanate, tolidine diisocyanate, tetraalkyldiphenylmethane diisocyanate, and paraphenylene diisocyanate.

Examples of the above triisocyanates include:
Lysine ester triisocyanate, triphenylmethane triisocyanate, 1,6,11-undecatriisocyanate, 1,8-diisocyanate-4,4-isocyanatomethyloctane, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate And the like.

The above-mentioned polyisocyanate compounds may be used alone or in combination of two or more. The compound (B) having a hydrophilic group having ionic, nonionic or latent ionic properties in the molecule, and further having two or more active hydrogens capable of reacting with isocyanate, is capable of self-forming to the urethane polymer or urethane prepolymer. It is used to provide emulsifying properties.

Examples of the ionic hydrophilic group include a sulfonate group, a carboxylate group and an ammonium group. Examples of the nonionic hydrophilic group include a polyoxyethylene group and a hydroxyl group.

The latent ionic group is a functional group which can be completely or partially changed to an ionic group by adding an appropriate compound before or during the dispersion operation. Specifically, it is preferable to use a free acid group (potentially anionic group) such as a carboxylic acid group or a sulfonic acid group. Specific examples of such compounds include dimethylolpropionic acid, dimethylolbutyric acid, dimethylolvaleric acid, lysine, serine, arginine, 2,4-diaminobenzoic acid, 3,4-diaminobutanesulfonic acid,
3,6-diamino-2-toluenesulfonic acid, 2,6-
Examples thereof include diaminobenzenesulfonic acid and N- (2-aminoethyl) -2-aminoethylsulfonic acid.

Among them, dimethylol alkanoic acid compounds having a structure represented by the following formula, such as dimethylolpropionic acid, dimethylolbutyric acid, and dimethylolvaleric acid, are preferably used.

[0017]

Embedded image

In the general formula (1), R is
It represents an alkyl group having 1 to 20 carbon atoms. The compound (B) having a hydrophilic group and having two or more active hydrogens capable of reacting with isocyanate may be used alone or in combination of two or more.

Compound (B) having the above hydrophilic group and having at least two active hydrogens capable of reacting with isocyanate
Is preferably in the range of 0.1 to 2 mmol per 1 g of the obtained urethane polymer and / or urethane prepolymer. If the amount is less than 0.1 mmol, the hydrophilicity of the urethane polymer and / or urethane prepolymer is insufficient, and it may be difficult to stably disperse the urethane polymer and / or urethane prepolymer in water. If the amount exceeds 2 mmol, the hydrophilicity of the urethane polymer and / or urethane prepolymer becomes too high, and the water resistance of the dried film may decrease.

When a compound having a functional group having latent ionicity is used among the compounds (B), acid groups in the urethane polymer and / or urethane prepolymer are completely or partially neutralized. By using a neutralizing agent, ionicity can be exhibited.

Examples of the neutralizer include, but are not limited to, alkali metal hydroxides such as NaOH and KOH, and tertiary amines such as ammonia, trimethylamine and triethylamine. In particular, it is desirable to use a volatile tertiary amine since it can be removed by being scattered during drying, so that the water resistance of the film does not decrease.

The compound (C) having two or more active hydrogens capable of reacting with isocyanate in the molecule is not particularly limited. For example, polyether polyols such as polypropylene glycol diol and polypropylene glycol triol obtained from polyethylene glycol and polypropylene glycol; dicarboxylic acids such as adipic acid, sebacic acid, itaconic acid, maleic anhydride, terephthalic acid, and isophthalic acid; and ethylene glycol Polyester polyols obtained from glycols such as diethylene glycol, triethylene glycol, 1,4-butanediol, 1,6-hexanediol, tripropylene glycol and neopentyl glycol; polycaprolactone polyol; polytetramethylene ether polyol; polybutadiene Polyol; hydrogenated polybutadiene polyol; polycarbonate polyol; polythioether polyol ; And the like polyacrylate polyols. These compounds may be used alone or in combination of two or more.

The number average molecular weight of the compound (C) is 600
It is necessary to be in the range of 0 to 50,000, but it is more preferably 6,000 or more and 30,000 or less, and further preferably 7000 or more and 30,000 or less. When the number average molecular weight is less than 6,000, the urethane particles become hard, and the adhesion and adhesion to inorganic materials and porous materials are not sufficient. When the number average molecular weight exceeds 50,000, the urethane polymer and / or urethane before water dispersion is used. The viscosity of the prepolymer becomes too high, making it difficult to stably disperse it in water.

Urethane polymer and / or urethane
Synthesis of Repolymer The synthesis of a urethane polymer and / or urethane prepolymer having self-emulsifying properties can be performed by any polymerization method such as bulk polymerization and solution polymerization.
It is preferable that the temperature be in the range of 150 ° C. If the temperature is lower than 50 ° C., the reaction takes a long time. If the temperature exceeds 150 ° C., side reactions such as burette generation may occur.

When solution polymerization is used, the solvent used is, for example, inert to isocyanate groups such as acetone, methyl ethyl ketone, tetrahydrofuran, and methyl acetate, excellent in miscibility with water, and
Those having a boiling point of 00 ° C. or less are preferred. This is because when a solvent having a boiling point higher than 100 ° C. is used, it is difficult to remove only the solvent from the obtained dispersion to the outside in the step after water dispersion.

When synthesizing the self-emulsifying urethane polymer and / or urethane prepolymer, a catalyst such as an amine compound or an organometallic compound may be used to adjust the reaction rate.

Examples of the above amine compound include triethylamine, N, N, N ', N'-tetramethylethylenediamine, tetramethylguanidine, triethylenediamine, dimethylaminoethanol, bis (2-dimethylaminoethyl) ether and the like. Can be mentioned.

Examples of the organometallic compound include tin octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dimaleate, phenylmercuric propionate, and lead octenoate. The above catalysts may be used alone or in combination of two or more.

Tackifying Resin In the urethane emulsion and the aqueous adhesive of the present invention, a tackifying resin is dispersed in water together with the urethane polymer and / or urethane prepolymer having self-emulsifiability. As the tackifier resin, a suitable tackifier resin conventionally used in pressure-sensitive adhesives and the like can be used, for example, gum rosin, tall oil rosin, wood rosin, polymerized rosin, hydrogenated rosin, disproportionated rosin,
Rosin-based resins such as rosin ester, hydrogenated rosin ester, disproportionated rosin ester, rosin-modified phenol resin, and maleic acid-modified rosin resin; terpene resin; phenolic resin; terpene phenolic resin; xylene resin; ketone resin; Resins; aromatic petroleum resins; alicyclic petroleum resins; cumarone resins, styrene resins, and the like.

As the tackifying resin, a xylene resin obtained by a known method from meta-xylene and formaldehyde, and an alkyl-substituted resin such as phenol and para-t-butylphenol can be used to further improve the adhesion and adhesion to metals and the like. A xylene resin modified by a phenol such as a bifunctional phenol, a ketone resin obtained by a known method from a ketone compound such as cyclohexanone or methyl ethyl ketone and formaldehyde, or an alkyl-substituted phenol such as phenol or para-t-butylphenol. A novolak-type phenol resin obtained by reacting a functional phenol or the like with formaldehyde according to a known method in the presence of an acid catalyst,
It is particularly preferable to use an alkylphenol resin or the like. The tackifier resin may be used alone,
More than one species may be used in combination.

The amount of the tackifier resin is from 5 to 200 parts by weight, preferably from 5 to 150 parts by weight, based on 100 parts by weight of the urethane polymer and / or urethane prepolymer. Preferably 1
It is from 0 parts by weight to 100 parts by weight. When the addition amount of the tackifier resin is less than 5 parts by weight, the effect of improving the adhesiveness may not be sufficiently obtained. This is because the ratio of the water-soluble component becomes extremely high, and a stable aqueous dispersion may not be obtained.

The softening point of the tackifying resin is preferably from 60 ° C. to 160 ° C. If the temperature is lower than 60 ° C., the heat resistance of the dried film may be poor,
If the temperature exceeds ℃, the adhesive strength may be reduced.

Preparation of Urethane Emulsion The urethane emulsion according to the present invention can be prepared by mixing the urethane polymer and / or urethane prepolymer with a tackifier resin and dispersing the resulting mixture in water.

As a method for dispersing the above mixture in water,
Acetone method for dispersing an organic solvent solution of polyurethane in water; self-emulsification of a prepolymer having an isocyanate group at the end; and prepolymer mixing method for chain extension; mixture of a prepolymer having a blocked isocyanate group at the end and a chain extender Block isocyanate method of deblocking after dispersing in water and extending the chain; melt dispersing method in which an ionic prepolymer having a burette group is heated and melted and dispersed in water, then methylolated with formaldehyde, and further chain extended. be able to.

When dispersing the urethane polymer and / or urethane prepolymer having the self-emulsifying property in water, acetone or acetone is used so that the viscosity of the urethane polymer and / or urethane prepolymer is 50,000 cps (23 ° C.) or less. It is preferable to adjust the viscosity with a hydrophilic organic solvent such as methyl ethyl ketone, tetrahydrofuran, ethyl acetate, N-methylpyrrolidone. If the viscosity exceeds 50,000 cps, it may aggregate when dispersed in water.

The mixture of the urethane polymer and / or urethane prepolymer having the self-emulsifying property and the tackifying resin must be sufficiently mixed to form a uniform system. If the mixture is non-uniform, it may cause agglomeration when dispersed in water, or the resulting emulsion may have reduced stability and sediment. In such a case, the amount of the hydrophilic organic solvent used may be appropriately adjusted so that the mixture becomes a homogeneous system.

As a method for dispersing a mixture comprising the urethane polymer and / or urethane prepolymer having self-emulsifiability and a tackifying resin in water, for example,
A batch milling method such as a method of gradually adding water to the mixture while applying mechanical shearing force, a method of gradually adding the mixture to water under shearing force, a method using a rotor and a stator, a line mill A continuous method of quantitatively supplying and dispersing water and the above mixture to various continuous emulsifying and dispersing machines such as a system using a static mixer, a system giving vibration, and the like can be adopted.

In the present invention, when the prepolymer having a terminal isocyanate group is dispersed in water, after or simultaneously with the dispersion step, the compound having two active hydrogens capable of reacting with the isocyanate group and / or water is used. Chain extend the urethane prepolymer.

Examples of the compound having two active hydrogens capable of reacting with an isocyanate group used as a chain extender for the urethane prepolymer include ethylenediamine, 1,4-butanediamine and 1,6-hexamethylenediamine. , 3-aminomethyl-3,5,5-trimethylcyclohexylamine, 1,3-bis (aminomethyl)
Cyclohexane, xylylenediamine, piperazine,
2,5-dimethylpiperazine, 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-
Diamino compounds such as dicyclohexylmethanediamine, ethylene glycol, propylene glycol, 1,
Examples thereof include diol compounds such as 4-butanediol and 1,6-hexanediol.

The amount of the compound as a chain extender having two active hydrogens capable of reacting with the isocyanate group is preferably not more than the equivalent of the isocyanate group which is the starting point of the chain extension in the obtained urethane prepolymer. . When the above compound is added as a chain extender exceeding the equivalent of the isocyanate group, the molecular weight of the chain-extended urethane prepolymer may decrease, and the cohesive force of the dried film of the emulsion may decrease.

The compound having two active hydrogens capable of reacting with the isocyanate group has a higher nucleophilicity to the isocyanate group than the water existing as a dispersion medium, and thus has a higher priority than the water existing as a dispersion medium. The reaction will proceed.

The urethane prepolymer is chain-extended by water. In this case, water as a dispersion medium present during the dispersion step also serves as a chain extender. In the chain extension reaction with water, the amine generated by the reaction between the isocyanate group and water in the urethane prepolymer always reacts with a new isocyanate group. It does not exceed the equivalent of isocyanate groups.

A urethane emulsion is prepared as described above. In the synthesis of a urethane polymer and / or urethane prepolymer having self-emulsifiability, when mixing a tackifying resin or when dispersing the mixture in water. After the hydrophilic organic solvent added as necessary is dispersed in water, it can be removed from the system by means such as heating, reduced pressure or reduced pressure heating. If a large amount of these hydrophilic organic solvents remain in the aqueous dispersion, the solvent resistance and heat resistance of the dried film of the aqueous emulsion may be reduced, or the working environment may be deteriorated.

The urethane emulsion of the present invention may further comprise a crosslinking agent, an elastomer, a synthetic resin, an aqueous dispersion of an adhesion-imparting resin, a plasticizer,
Pigments, inorganic fillers, coupling agents, stabilizers, thickeners,
An antifoaming agent, a fungicide, a rust inhibitor and the like may be added.

The addition of the above-mentioned cross-linking agent can further enhance the adhesiveness / adhesion to metals and the like. When one or more selected from sulfonic acid groups and sulfonate groups are used, for example, isocyanate-based, melamine-based, aziridine-based, epoxy-based, oxazoline-based, carbodiimide-based, and metal-based crosslinkers are used. Particularly preferably used are aziridine-based, epoxy-based, isocyanate-based, oxazoline-based, carbodiimide-based, more preferably aziridine-based, epoxy-based, carbodiimide-based ones dissolved in water, those dispersed in water, Or it is self-emulsifying. These can be used alone or in combination of two or more. If the amount of the cross-linking agent is too small, the effect of the addition cannot be sufficiently obtained, and if it is too large, no further effect can be obtained and it becomes uneconomical, so that the obtained urethane prepolymer and / or urethane polymer 100 weight The amount of the crosslinking agent added is 0.5 to 5 parts per part.
0 parts by weight is preferable, and 1 to 30 parts by weight is particularly preferable.

The addition of the above-mentioned elastomer can further enhance the adhesiveness / adhesion to inorganic materials and porous materials. Examples of this elastomer include styrene-butadiene rubber, butadiene rubber, isoprene rubber,
Synthetic rubber such as acrylonitrile-butadiene rubber, chloroprene rubber, butyl rubber, styrene-based thermoplastic elastomer, olefin-based thermoplastic elastomer, urethane-based thermoplastic elastomer, polyester-based thermoplastic elastomer, and natural rubber are exemplified. These can be used alone or in combination of two or more. If the amount of the elastomer is too small, the effect of the addition cannot be sufficiently obtained. If the amount is too large, the adhesiveness / adhesion to metal or the like is reduced.
Alternatively, the amount of the elastomer added is preferably 0.1 to 300 parts by weight per 100 parts by weight of the urethane polymer.

The addition of the above-mentioned synthetic resin can further enhance the adhesiveness / adhesiveness to an inorganic material or a porous material. Examples of the synthetic resin include (meth) acrylic, epoxy and vinyl acetate based resins. , Vinyl acetate-ethylene copolymer system, ethylene-ethyl acrylate copolymer system,
Examples thereof include ethylene- (meth) acrylic acid copolymers, vinyl chlorides, phenoxys, and styrenes. These can be used alone or in combination of two or more. If the amount of the synthetic resin is too small, the effect of the addition cannot be sufficiently obtained, and if the amount is too large, the adhesiveness / adhesiveness to metal or the like is reduced. The amount of the resin added is 0.1 to
300 parts by weight are preferred.

Examples of the plasticizer include phthalic esters such as diethyl phthalate, dibutyl phthalate and dioctyl phthalate; and phosphoric acids such as tributyl phosphate, triphenyl phosphate and tris (β-chloropropyl) phosphate. Esters, fatty acid esters such as butyl oleate, dibutyl adipate, di-n-hexyl adipate, dibutyl sebacate, dihydric alcohol esters such as diethylene glycol dibenzoate, butyl acetyl ricinoleate, tributyl acetyl citrate and the like Oxy acid esters and the like can be mentioned. These can be used alone or in combination of two or more. The amount of the plasticizer to be added is 0.5 to 100 parts by weight of the obtained urethane prepolymer and / or urethane polymer.
-100 parts by weight are preferred.

Examples of the pigment include mica-like iron oxide, lead white, lead white, lead red, graphite, silver vermilion, ultramarine, navy blue, cobalt oxide, titanium dioxide, titanium dioxide-coated mica, strontium chromate, titanium yellow, titanium black Inorganic pigments such as zinc chromate, iron black, molybdenum red, molybdenum white, litharge, and liptone; azo pigments; dyed lakes; organic pigments such as anthraquinone and phthalocyanine; These can be used alone or in combination of two or more. The amount of the pigment to be added may be, per 100 parts by weight of the obtained urethane prepolymer polymer and / or urethane polymer,
0.1 to 200 parts by weight is preferred.

Examples of the inorganic filler include oxides such as silica, alumina, titania, zirconia, zinc oxide, magnesium oxide, and iron oxide; calcium carbonate;
Carbonates such as magnesium carbonate and zinc carbonate, magnesium silicate, calcium silicate, kaolin, clay, talc,
Silicates such as mica, zeolite and sericite, hydroxides such as aluminum hydroxide and magnesium hydroxide, sulfuric acid and sulfites such as calcium sulfate, barium sulfate and calcium sulfite, nitriding such as boron nitride and silicon nitride Substances, titanates such as potassium titanate and barium titanate, and others, water glass, dawsonite, carbon black, silicon carbide and the like. These can be used alone or in combination of two or more. The amount of the inorganic filler to be added is 1 to 100 parts by weight of the obtained urethane prepolymer and / or urethane polymer.
~ 200 parts by weight are preferred.

Examples of the coupling agent include a silane coupling agent, a titanate coupling agent, and a polyphenol compound. Examples of the silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane. Silane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl- γ-
Examples include aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and the like.

Examples of the titanate-based coupling agent include isopropyl triisostearoyl titanate, isopropyl tri-n-dodecylbenzenesulfonyl titanate, tetraoctyl bis (dioctyl phosphite) titanate, bis (dioctyl pyrophosphate) ethylene titanate, isopropyl Trioctanoyl titanate, isopropyl tri (N-aminoethyl-aminoethyl) titanate, isopropyl tri (dioctyl phosphate) titanate and the like can be mentioned.

Examples of the above-mentioned polyphenol compounds include gallic acid, tannic acid, polytannic acid and the like. These coupling agents can be used alone or in combination of two or more. The amount of the coupling agent to be added is 0.1 to 100 parts by weight of the obtained urethane prepolymer and / or urethane polymer.
1 to 20 parts by weight is preferred.

Examples of the stabilizer include an antioxidant, an ultraviolet absorber, and an ultraviolet stabilizer. Examples of the antioxidant include 2,6-di-t-butyl-p-cresol and butylated hydroxy. Anisole, 2,6-di-t-
Monophenols such as butyl-4-ethylphenol,
2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-
Bisphenols such as 6,6-t-butylphenol) and 4,4'-butylidenebis (3-methyl-6-t-butylphenol); and 1,1,3-tris (2-methyl-4-
(Hydroxy-5-t-butylphenyl) butane, 1,
3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl) -4'-hydroxyphenyl) propionate] High molecular phenols such as methane, sulfuric such as 3,3'-dilauryl thiodipropionate, distearyl 3,3'-thiodipropionate, triphenyl phosphite, diphenyl Phosphorus such as isodecyl phosphite, phenyl diisodecyl phosphite, and tris (2,4′-di-t-butylphenyl) phosphite are exemplified.

Examples of the ultraviolet absorber include salicylic acids such as phenyl salicylate and pt-butylphenyl salicylate; 2,4-dihydroxybenzophenone;
-Hydroxy-4-methoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2 '
Benzophenones such as dihydroxy-4,4'-dimethoxybenzophenone, 2- (2'-hydroxy-5 '
-Methylphenyl) benzotriazole, 2- (2'-
Benzotriazoles such as hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2-ethylhexyl-2-cyano-3,3 '
-Diphenyl acrylate, ethyl-2-cyano-3,
Examples include cyanoacrylates such as 3′-diphenylacrylate.

Examples of the ultraviolet stabilizer include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and bis (2,2,6,6-tetramethyl-succinate).
Hindered amines such as 4-piperidyl) and 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-
Benzoate type such as hydroxybenzoate and the like can be mentioned. These stabilizers can be used alone or in combination of two or more. The amount of the stabilizer to be added is preferably 0.01 to 20 parts by weight per 100 parts by weight of the obtained urethane prepolymer and / or urethane polymer.

The method of adding the above-mentioned various additives is not particularly limited. For example, in addition to a method of adding the above-mentioned additives directly or as an aqueous dispersion to a urethane emulsion, a urethane polymer having self-emulsifiability and And / or a method of previously mixing a mixture of a urethane prepolymer and a tackifier resin and dispersing the mixture in water to obtain an aqueous dispersion.

When an aqueous dispersion of a synthetic resin is added among the above-mentioned various additives, adhesion and adhesion to inorganic materials and porous materials, and water resistance are further enhanced.
The addition of a synthetic resin aqueous dispersion is preferred. Further, when a cross-linking agent or an aqueous dispersion of a tackifier resin is added, adhesion and adhesion to metals and the like, water resistance, and heat resistance are further enhanced, and thus the addition of a cross-linking agent is preferable.

The urethane emulsion of the present invention obtained as described above is used in a form having a viscosity of 100,000 cps (23 ° C.) or less and a solid content of 20 to 75% by weight. Adjust to concentration,
It can be applied by a spray, a roll coater, a flow coater or a brush.

Also, the urethane emulsion of the present invention
After the application, drying is performed without forced drying or by forced drying. In order to increase productivity, forced drying is preferable. The drying conditions in this case are preferably a temperature of 30 to 150 ° C. and a drying time of 20 minutes or less.

The aqueous adhesive according to the present invention contains the urethane emulsion as a main component. When used as an adhesive, it is used by applying it to at least one of the adherends to be bonded. The coating amount in this case is preferably in the range of 10 g to 300 g / m ² of solid content per one surface. If it is less than 10 g / m ² , sufficient adhesive strength cannot be obtained, and if it exceeds 300 g / m ² , the drying time will be long. If necessary, at the time of bonding or after bonding, pressure bonding is performed using a roll press, a hydraulic press, a turnbuckle, or the like. 01-200kg /
A compression pressure of cm ² is preferred.

The water-based adhesive according to the present invention contains the above-mentioned urethane emulsion as a main component. The above-mentioned various additives and other appropriate additives conventionally used in water-based adhesives using a urethane emulsion have been used. It can be added as long as the object of the present invention is not hindered.

When the aqueous adhesive according to the present invention is used, the adherend is not particularly limited, but can be used for adherends such as metals, plastics, inorganic materials, wood and paper. Examples of uses of the product include production of doors, partitions, exterior materials, desk top plates, packaging films and sheets for foods, and the like.

The aqueous urethane emulsion according to the first aspect of the present invention has at least one hydrophilic group among ionic groups, nonionic groups and latent ionic groups in the molecule, and When the compound (B) having two or more active hydrogens capable of reacting with an isocyanate group is used, the urethane prepolymer and / or the urethane polymer have a self-emulsifying property, and the number average molecular weight is within the above specific range. Since the compound (C) having two or more active hydrogens capable of reacting with an isocyanate group is used, the soft segment of the urethane emulsion can be easily deformed. Therefore, not only the water resistance is excellent, but also the adhesion and the adhesion to the surface with large unevenness such as an inorganic material or a porous material are effectively enhanced.

[0065]

EXAMPLES Hereinafter, non-limiting examples and comparative examples of the present invention will be described. (Example 1) 100 parts by weight of polypropylene glycol diol having a number average molecular weight of 10,000 (manufactured by Asahi Glass Co., Ltd., trade name: Preminol 4010, OH value = 11) as compound C, 3-isocyanatomethyl-3, as compound A
2,1.4 parts by weight of 5,5-trimethylcyclohexyl isocyanate (trade name: Bestant IPDI, manufactured by Huls Co.), and dimethylolpropionic acid 5.1 as compound B
The boiling point polymerization was carried out while stirring a mixed solution consisting of parts by weight (trade name: DMPA, equivalent ratio of (isocyanate group / hydroxyl group) = 2.0) manufactured by Trimet Technical Products and 31.6 parts by weight of methyl ethyl ketone. This was performed so that the content of isocyanate groups was 2.6% by weight or less. Next, 52.7 parts by weight of methyl ethyl ketone, 3.8 parts by weight of triethylamine as a neutralizing agent, and a novolak-type alkylphenol resin solution (Titanium Chemical Co., Ltd., trade name: 78.0 parts by weight of titanol 1501, softening point 95 ° C., 50% by weight of methyl ethyl ketone solution (solid content: 39.0%)
0 parts by weight).

Next, while vigorously stirring the reaction mixture at room temperature, 310 parts by weight of water was further added, and immediately thereafter, a 20% by weight aqueous solution of ethylenediamine as a chain extender was added.
5 parts by weight (2.7 parts by weight of solid content) was added, and the mixture was further stirred at room temperature for 1 hour.
A 0% by weight aqueous composition was obtained.

Example 2 As compound C, polypropylene glycol diol having a number average molecular weight of 20,000 (manufactured by Asahi Glass Co., Ltd., trade name: Preminol 4019, OH value = 5.
6) 100 parts by weight, as compound A, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (manufactured by Huls, trade name: Bestant IPD)
I) 18.9 parts by weight, 5.0 parts by weight of dimethylolpropionic acid as compound B (trade name: DMPA, manufactured by Trimet Technical Products, equivalent ratio of (isocyanate group / hydroxyl group) = 2.0), and Methyl ethyl ketone 3
The mixed solution consisting of 1.0 part by weight is subjected to boiling point polymerization under stirring so that the content of isocyanate groups becomes 2.3% by weight or less, and 51.6 parts by weight of methyl ethyl ketone for viscosity adjustment. 3.8 parts by weight of triethylamine as a neutralizing agent and 126 parts by weight of a ketone resin solution (trade name: Hilac 111, manufactured by Hitachi Chemical Co., Ltd., softening point of resin = 110 ° C., 50% by weight of methyl ethyl ketone) as a tackifier resin (63.0 parts by weight as a solid content) was added.

Next, while the reaction mixture was vigorously stirred at room temperature, 350 parts by weight of water was added, and immediately thereafter, 12.0 parts by weight of a 20% by weight aqueous solution of ethylenediamine as a chain extender (2.4 parts by solids). Parts by weight), and the mixture was further stirred at room temperature for 1 hour.
% By weight of the aqueous composition was obtained.

Example 3 As compound C, polypropylene glycol triol having a number average molecular weight of 7,000 (manufactured by Asahi Glass Co., Ltd., trade name: Preminol 7005, OH value = 2)
4) 100 parts by weight, as compound A, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (trade name: Bestant IPD manufactured by Huls Co.)
I) 27.4 parts by weight, 5.4 parts by weight of dimethylolpropionic acid as compound B (trade name: DMPA, manufactured by Trimet Technical Products, equivalent ratio of (isocyanate group / hydroxyl group) = 2.0), and Methyl ethyl ketone 3
The mixed solution composed of 3.2 parts by weight was subjected to boiling point polymerization under stirring to adjust the content of isocyanate groups to 3.1% by weight or less, and 55.3 parts by weight of methyl ethyl ketone was added to the system to adjust the viscosity. Parts, 4.1 parts by weight of triethylamine as a neutralizing agent, and a novolak-type alkylphenol resin solution as a tackifying resin (Hitanol 1501, manufactured by Hitachi Chemical Co., Ltd., softening point 95 ° C., 50 parts by weight methyl ethyl ketone solution) 80.0 Parts by weight (4
0.0 parts by weight).

Next, 320 parts by weight of water was added to the above reaction mixture while stirring vigorously at room temperature, and immediately thereafter, 17 parts by weight of a 20% by weight aqueous ethylenediamine solution as a chain extender (3.4 parts by weight in solid content) ) Was added thereto, and the mixture was further stirred at room temperature for 1 hour, and then the pressure was reduced and the solvent was removed to obtain an aqueous composition having a solid content of 40% by weight.

(Example 4) Solid content 4 obtained in Example 1
An aqueous dispersion of an aziridine-based crosslinking agent (trade name: Chemitite DZ-22E, manufactured by Nippon Shokubai Co., Ltd.) was added to an aqueous composition of 0% by weight.
20 parts by weight (solid content: 25% by weight) (solid content: 5.0 parts by weight)
Was added to obtain an aqueous composition having a solid content of 39% by weight.

(Example 5) Solid content 4 obtained in Example 2
0% by weight of an aqueous composition was mixed with a water-soluble epoxy-based crosslinking agent (trade name: Denacol EX-512, manufactured by Nagase Kasei Kogyo Co., Ltd.).
(100% by weight of solid content diluted with water to 50% by weight) 11.4
By weight (5.7 parts by weight of solid content) was added to obtain an aqueous composition having a solid content of 40% by weight.

(Example 6) Solid content 4 obtained in Example 1
An aqueous dispersion of a resole type alkylphenol resin (trade name: HRJ10, manufactured by Nippon Shokubai Co., Ltd.) was added to an aqueous composition of 0% by weight.
416, solid content 53% by weight) 95.3 parts by weight (solid content 5
0.5 part by weight) to obtain an aqueous composition having a solid content of 42% by weight.

(Example 7) Solid content 4 obtained in Example 2
To an aqueous composition of 0% by weight, 158 parts by weight of an acrylic emulsion (manufactured by Asahi Kasei Corporation, trade name: Polytron U-154, solid content: 60% by weight) (solid content: 95.0 parts by weight) was added, and the solid content was 45% by weight. % Of an aqueous composition was obtained.

Comparative Example 1 Polypropylene glycol diol having a number average molecular weight of 2000 (Nissan Uniol D-2000, manufactured by NOF Corporation, OH value = 58)
100 parts by weight, 3-isocyanatomethyl-3,5,5
-43.1 parts by weight of trimethylcyclohexyl isocyanate (manufactured by Huls, trade name: Bestant IPDI),
A mixed solution containing 6.1 parts by weight of dimethylolpropionic acid (manufactured by Trimet Technical Products, trade name: DMPA, equivalent ratio of (isocyanate group / hydroxyl group) = 2.0), and 37.3 parts by weight of methyl ethyl ketone was prepared. The mixture is subjected to boiling point polymerization under stirring so that the isocyanate group content becomes 4.3% by weight or less. To adjust the viscosity of the system, 62.1 parts by weight of methyl ethyl ketone and 4.6 of triethylamine as a neutralizing agent are added. 90.0 parts by weight (solid content: 45.0 parts by weight) of a novolak type alkylphenol resin solution (manufactured by Hitachi Chemical Co., Ltd., trade name: Hitachil 1501, softening point 95 ° C, 50% by weight methyl ethyl ketone solution) were added.

Next, 360 parts by weight of water was added to the above reaction mixture while stirring vigorously at room temperature, and immediately thereafter, 27.5 parts by weight of a 20% by weight aqueous ethylenediamine solution (solid content: 5.5)
After stirring for 1 hour at room temperature, the pressure was reduced and the solvent was removed to obtain an aqueous composition having a solid content of 40% by weight.

Comparative Example 2 100 parts by weight of polypropylene glycol diol having a number average molecular weight of 10,000 (trade name: Preminol 4010, OH value = 11, manufactured by Asahi Glass Co., Ltd.), 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate 21.4 parts by weight (manufactured by Huls, trade name: Bestant IPDI), 5.1 parts by weight of dimethylolpropionic acid (manufactured by Trimet Technical Products, trade name: DMPA, equivalent ratio of (isocyanate group / hydroxyl group) = 2.0), and a mixed solution containing 31.6 parts by weight of methyl ethyl ketone is subjected to boiling point polymerization under stirring, so that the content of isocyanate groups becomes 2.6% by weight or less. 52.7 parts by weight of methyl ethyl ketone and 3.8 parts by weight of triethylamine as a neutralizing agent were added. It was.

Next, 230 parts by weight of water was added to the above reaction mixture while stirring vigorously at room temperature, and immediately thereafter, 13.5 parts by weight of a 20% by weight aqueous ethylenediamine solution (solid content: 2.7%) was added.
After stirring for 1 hour at room temperature, the pressure was reduced and the solvent was removed to obtain an aqueous composition having a solid content of 40% by weight.

(Comparative Example 3) Solid content 4 obtained in Comparative Example 1
An aqueous dispersion of an aziridine-based crosslinking agent (trade name: Chemitite DZ-22E, manufactured by Nippon Shokubai Co., Ltd.) was added to an aqueous composition of 0% by weight.
24 weight parts (solid content: 6.0 weight parts)
Was added to obtain an aqueous composition having a solid content of 39% by weight.

Comparative Example 4 Solid content 4 obtained in Comparative Example 1
An aqueous dispersion of a resole type alkylphenol resin (trade name: HRJ10, manufactured by Nippon Shokubai Co., Ltd.) was added to an aqueous composition of 0% by weight.
416, solid content 53% by weight) 113 parts by weight (solid content 6
0.0 parts by weight) to obtain an aqueous composition having a solid content of 42% by weight.

(Comparative Example 5) Solid content 4 obtained in Comparative Example 1
To an aqueous composition of 0% by weight, 166 parts by weight of an acrylic emulsion (manufactured by Asahi Kasei Corporation, trade name: Polytron U-154, solid content of 60% by weight) (solid content of 100 parts by weight) was added,
An aqueous composition having a solid content of 45% by weight was obtained.

Each of the aqueous compositions obtained in Examples 1 to 7 and Comparative Examples 1 to 5 was tested for normal adhesion to flexible boards and normal adhesion to cold-rolled steel sheets in the following manner. The results are shown in Tables 1 and 2 below.

(1) Adhesion to flexible board in normal state The obtained aqueous composition was applied to a canvas and a flexible board (width 25 mm, length 125 mm, thickness 2.5 mm) by brushing. The coating amount, solid content 100 g / m ² for the canvas was a solid content 60 g / m ² for a flexible board. After applying the aqueous composition, 80
After drying for 4 minutes in a blast drying oven at
At 0 kg / 25 mm, the surfaces of the canvas and the flexible board to which the aqueous composition had been applied were roll-pressed together to prepare test pieces.
After the obtained test piece was cured at 23 ° C. for a week, a 90 ° peel test was performed at 23 ° C. at a pulling speed of 50 mm / min.

(2) Adhesion of Cold Rolled Steel Sheet to Normal Condition The obtained aqueous composition was applied to a canvas and a cold rolled steel sheet (width 25 mm).
(mm, length 125 mm, thickness 0.8 mm) by brush coating. The coating amount is 100 g / m ^{2 of} solid content for canvas, and 6 g of solid content for cold rolled steel sheet.
0 g / m ² . After the canvas and the cold-rolled steel sheet coated with the aqueous composition were dried in an air-drying oven at 80 ° C. for 4 minutes, the coated surface of the canvas and the cold-rolled steel sheet was roll-pressed at a pressure of 60 kg / 25 mm to obtain a test piece. Produced. After curing the obtained test piece at 23 ° C. for one week,
A 90 degree peel test was performed at a pulling speed of mm / min.

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[Table 1]

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[Table 2]

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According to the first aspect of the present invention, the molecule has at least one hydrophilic group among an ionic group, a nonionic group and a latent ionic group, and isocyanate group. The use of the above-mentioned specific compound (B) having two or more active hydrogens capable of reacting with the compound provides self-emulsifiability, a number average molecular weight in the above-mentioned specific range, and an activity capable of reacting with an isocyanate group. Since the compound (C) having two or more hydrogen atoms is used, it is possible to provide a urethane emulsion which is not only excellent in water resistance but also excellent in adhesion and adhesion to an adhered surface having large unevenness. Becomes

According to the second aspect of the present invention, not only the water resistance is excellent as described above, but also the adhesiveness to an uneven surface such as an inorganic material or a porous material is excellent. An aqueous adhesive can be easily provided.

Therefore, according to the present invention, it is possible to provide an adhesive, a pressure-sensitive adhesive, a coating agent, a paint, etc. which are not only excellent in water resistance but are suitable for a wide range of uses, although they are water-based.

Claims (2)

[Claims] 1. A polyisocyanate compound (A) having at least one hydrophilic group among an ionic group, a nonionic group and a potential ionic group in a molecule and capable of reacting with an isocyanate group. The compound (B) having two or more active hydrogens and the compound (C) having a number average molecular weight in the range of 6,000 to 50,000 and having two or more active hydrogens capable of reacting with an isocyanate group have self-emulsifiability. A urethane emulsion obtained by dispersing a urethane polymer and / or urethane prepolymer and a tackifier resin in water. 2. An aqueous adhesive comprising the urethane emulsion according to claim 1 as a main component.