JP2001002911A - Hydroxyl group-containing aqueous polyurethane resin composition, two-part type aqueous polyurethane composition, and adhesive and coating agent comprising the composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hydroxyl group-containing aqueous polyurethane resin composition capable of providing a two-part type aqueous polyurethane composition having excellent adhesion even to a hardly adhesive plastic substrate and excellent even in film physical properties, the two-part type aqueous polyurethane composition comprising the composition as a principal component and adhesive and a coating agent comprising the two-part type aqueous polyurethane composition. SOLUTION: This hydroxyl group-containing aqueous polyurethane resin composition is obtained by carrying out a chain extending reaction of a neutralized substance of an isocyanate group-terminated prepolymer prepared by reacting (a) an organic polyisocyanate compound with (b) a high-molecular weight polyol containing a dimer diol and (c) a compound having an anionic hydrophilic group and two or more active hydrogens with (e) at least one kind of compound selected from a water-soluble polyamine and hydrazine or derivatives thereof, of without conducting the chain extending reaction, and blocking the terminal isocyanate groups with (d) a primary amine or a secondary amine compound having hydroxyl group. The two-part type aqueous polyurethane composition comprises the hydroxyl group- containing aqueous polyurethane resin composition as a principal component. The adhesive and coating agent comprise the two-part type aqueous polyurethane composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydroxyl group-containing aqueous polyurethane resin composition, a two-pack type aqueous polyurethane composition, and an adhesive and a coating agent containing the composition. More specifically, the present invention has excellent adhesion even to a plastic substrate with poor adhesion, hot water resistance,
Hydroxyl group-containing aqueous polyurethane resin composition that provides a two-part aqueous polyurethane composition having excellent alcohol resistance and abrasion resistance, two-part aqueous polyurethane composition containing the composition as a main component, and two-part aqueous polyurethane composition The present invention relates to an adhesive and a coating agent having excellent adhesion, hot water resistance, alcohol resistance, and abrasion resistance.

[0002]

2. Description of the Related Art Conventionally, organic solvent-based resins have been mainly used in the field of various adhesives, coatings such as paints and printing inks. For reasons such as environmental improvement, it is being replaced by aqueous resins. As aqueous resins for such uses, acrylic resins, polyester resins, polyurethane resins, and the like having a carboxyl group have been studied, and various attempts have been made to make the polyurethane resins water-soluble or water-dispersible. For example, Japanese Patent Publication No. 1-28067 and Japanese Patent Publication No. 28068/1990 disclose a polyurethane resin composition as an aqueous composition containing a polyurethane resin which is quick-drying and has good adhesion to a substrate of a coating. An aqueous composition in which a rosin skeleton is introduced into a polyurethane molecule using a rosin ester as a diol component as a raw material has been proposed. By introducing a rosin skeleton component,
Although the wettability and adhesion to hard-to-adhesive plastic substrates are improved, with a one-part aqueous adhesive, not only sufficient adhesion has yet to be obtained, but also hot water resistance,
There is a problem in abrasion resistance and the like, and applications are limited.
For this reason, there is a demand for an aqueous resin composition having sufficient adhesion to a poorly adherent plastic substrate and having hot water resistance, alcohol resistance and abrasion resistance.

[0003]

DISCLOSURE OF THE INVENTION The present invention relates to a two-component aqueous polyurethane which has excellent adhesion to a poorly adherent plastic substrate and is excellent in hot water resistance, alcohol resistance and abrasion resistance. Hydroxyl group-containing aqueous polyurethane resin composition giving the composition, two-component aqueous polyurethane composition containing the composition as a main component, adhesion, hot water resistance, and alcohol resistance containing the two-component aqueous polyurethane composition The purpose of the present invention is to provide an adhesive and a coating agent having excellent abrasion resistance.

[0004]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that a polyisocyanate compound, a high-molecular-weight polyol containing dimer diol and an anionic hydrophilic group have two The neutralized isocyanate group-terminated prepolymer obtained from the reaction of the compound having the above active hydrogen is chain-extended in water as necessary, and reacted with a primary amine or a secondary amine compound having a hydroxyl group. The two-pack type aqueous polyurethane composition obtained by blending a main agent comprising a hydroxyl group-containing aqueous polyurethane resin composition having a terminal isocyanate group blocked with a curing agent comprising an aqueous polyisocyanate compound has poor adhesion. It has excellent adhesion to plastic substrates, and has excellent hot water resistance, alcohol resistance, and abrasion resistance. And it has led to the completion of the present invention based on this finding. That is, the present invention provides (1) (a)
An organic polyisocyanate compound, (b) a high molecular weight polyol containing 1 to 40% by weight of dimer diol, and (c) an isocyanate group-terminated prepolymer obtained by reacting a compound having two or more active hydrogens with an anionic hydrophilic group. A hydroxyl group-containing aqueous polyurethane resin composition obtained by blocking a terminal isocyanate group with a neutralized product of (d) a primary amine or a secondary amine compound having a hydroxyl group in water, (2) ( a) organic polyisocyanate compound, (b) dimer diol 1 to 40
(E) a water-soluble polyamine; and (c) a neutralized product of an isocyanate group-terminated prepolymer obtained by reacting a high molecular weight polyol containing 2% by weight and a compound having two or more active hydrogens with an anionic hydrophilic group. After a chain extension reaction in water using at least one compound selected from hydrazine or a derivative thereof, or simultaneously with the chain extension reaction,
(D) a hydroxyl group-containing aqueous polyurethane resin composition obtained by blocking a terminal isocyanate group using a primary amine or secondary amine compound having a hydroxyl group, (3) (a) an organic polyisocyanate compound, First (1) which is at least one selected from aliphatic diisocyanate compounds and alicyclic diisocyanate compounds
The hydroxyl group-containing aqueous polyurethane resin composition according to item or (2), wherein (4) (b) the high molecular weight polyol is
The hydroxyl group-containing aqueous polyurethane resin composition according to the above item (1) or (2), which contains at least one of polyester polyol, polycarbonate polyol and polyether polyol as a component other than dimer diol at a ratio of 10 to 94% by weight. (5) (c) In the compound having an anionic hydrophilic group and two or more active hydrogens, the anionic hydrophilic group is a carboxyl group, and the content of the carboxyl group in the hydroxyl group-containing aqueous polyurethane resin is 0.3-2.5% by weight based on the weight of resin
The hydroxyl group-containing aqueous polyurethane resin composition according to item (1) or (2), wherein (6) (d) the primary amine or secondary amine compound having a hydroxyl group is
Monoethanolamine or diethanolamine,
The content of hydroxyl groups in the hydroxyl group-containing aqueous polyurethane resin is 0.1 to 5.0 based on the weight of the resin.
The hydroxyl group-containing aqueous polyurethane resin composition according to the item (1) or (2), which is in terms of (%) by weight, (7) (A) curing comprising a hydroxyl group (OH) as a main ingredient and (B) an aqueous polyisocyanate compound. Isocyanate group (NC
In a two-pack type aqueous polyurethane composition in which the equivalent ratio OH / NCO with O) is 1: 3 to 2: 1, (A)
The main ingredient is (1), (2), (3), (4),
(5) A two-component aqueous polyurethane composition which is the hydroxyl-containing aqueous polyurethane resin composition according to the item (6), or (8) a two-component aqueous polyurethane composition according to the item (7). An adhesive comprising: and (9) a coating composition comprising the two-component aqueous polyurethane composition according to item (7);
Is provided.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The first embodiment of the hydroxyl group-containing aqueous polyurethane resin composition of the present invention comprises (a) an organic polyisocyanate compound and (b) dimer diol
A high molecular weight polyol containing 40% by weight and a neutralized isocyanate group-terminated prepolymer obtained by reacting (c) a compound having two or more active hydrogens with an anionic hydrophilic group are converted into (d) hydroxylated water in water. It is obtained by blocking a terminal isocyanate group using a primary or secondary amine compound having a group. The second embodiment of the hydroxyl group-containing aqueous polyurethane resin composition of the present invention comprises (a) an organic polyisocyanate compound, (b) a high molecular weight polyol containing 1 to 40% by weight of dimer diol, and (c) an anionic hydrophilic group. And a compound having two or more active hydrogens and a neutralized isocyanate group-terminated prepolymer obtained by reacting (e) a water-soluble polyamine and hydrazine or a derivative thereof.
After a chain elongation reaction in water using the species compound, or
It is obtained by simultaneously blocking the terminal isocyanate group with a primary amine or secondary amine compound having a hydroxyl group (d) simultaneously with the chain extension reaction.

The (a) organic polyisocyanate compound used in the present invention is not particularly limited, but an aliphatic isocyanate compound and an alicyclic diisocyanate compound can be suitably used, and isophorone diisocyanate, dicyclohexylmethane diisocyanate, norborane diisocyanate and Hexamethylene diisocyanate can be particularly preferably used. One of these organic polyisocyanate compounds can be used alone, or two or more can be used in combination. The high molecular weight polyol (b) used in the present invention contains 1 to 40% by weight of dimer diol. Dimer diol is
It is a polyol containing diol as a main component obtained by reducing dimer acid. The dimer acid is mainly composed of unsaturated fatty acids having 18 carbon atoms such as oleic acid, linoleic acid, and linoleic acid, drying oil fatty acids, semi-dry oil fatty acids, and lower monoalkyl esters of these fatty acids. And Diels-Alder type bimolecular polymerization. Various types of dimer acids are commercially available, typically 0 to 5% by weight of monocarboxylic acids having 18 carbon atoms, 70 to 98% by weight of dimer acids having 36 carbon atoms and trimers having 54 carbon atoms. Acid 0-30
Some consist of weight percent. In the high molecular weight polyol (b) used in the present invention, if the content of the dimer diol is less than 1% by weight, the adhesion of the two-pack type aqueous polyurethane composition to the poorly adherent plastic substrate is insufficient. Could be. When the content of the dimer diol exceeds 40% by weight, the elasticity and abrasion resistance of the two-pack type aqueous polyurethane composition may be reduced. In consideration of the balance for sufficiently expressing the adhesion by the dimer diol, the content of the dimer diol is preferably 2 to 30% by weight, and more preferably 5 to 20% by weight.

In the (b) high molecular weight polyol used in the present invention, examples of components other than the dimer diol include polyester polyol, polycarbonate polyol, and polyether polyol. As the polyester polyol, for example, polyethylene adipate, polybutylene adipate, polyethylene butylene adipate, polyhexamethylene isophthalate adipate, polyethylene succinate, polybutylene succinate, polyethylene sebacate, polybutylene sebacate, poly-ε-caprolactone diol, Poly-3-methylpentane adipate, a polycondensate of 1,6-hexanediol and dimer acid, a copolycondensate of 1,6-hexanediol, adipic acid and dimer acid,
Examples include polycondensates of nonanediol and dimer acid, polycondensates of ethylene glycol and dimer acid, and copolycondensates of ethylene glycol, adipic acid and dimer acid. Examples of the polycarbonate polyol include polytetramethylene carbonate diol, polyhexamethylene carbonate diol, poly-1,4-cyclohexane dimethylene carbonate diol, and polyhexamethylene-1,4-cyclohexane dimethylene carbonate diol. . As polyether polyols, for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide and propylene oxide,
Examples include a random copolymer and a block copolymer of ethylene oxide and butylene oxide. Furthermore, it is also possible to use a polyether polyester polyol having an ether bond and an ester bond. These polyols other than dimer diol are:
The species can be used alone, or two or more can be used in combination.

In the present invention, (c) the compound having an anionic hydrophilic group and two or more active hydrogens is not particularly limited, but the anionic hydrophilic group is a carboxyl group and the active hydrogen is a hydrogen of a hydroxyl group. Compounds can be suitably used. Such compounds include, for example,
2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid and the like can be mentioned. Further, as such a carboxyl group-containing diol, a diol component obtained by optionally mixing a diol having a carboxyl group and a diol having no carboxyl group, and a dicarboxylic acid such as an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, or an alicyclic dicarboxylic acid. A polyester polyol having a pendant carboxyl group obtained from an acid can also be used. One of these compounds having an anionic hydrophilic group and two or more active hydrogens can be used alone, or two or more can be used in combination. In the present invention, the neutralized product of the isocyanate group-terminated prepolymer is (a) an organic polyisocyanate compound, (b)
After reacting a high molecular weight polyol and (c) a compound having two or more active hydrogens with an anionic hydrophilic group to obtain an isocyanate group-terminated prepolymer, the anionic hydrophilic group can be neutralized, or ( a) an organic polyisocyanate compound, (b) a high molecular weight polyol and (c)
The neutralized anisocyanate-terminated prepolymer can also be directly obtained by reacting the neutralized anionic hydrophilic group with a compound having two or more active hydrogens. There is no particular limitation on the compound used for neutralizing the anionic hydrophilic group, for example, amines such as trimethylamine, triethylamine, tri-n-propylamine, tributylamine, triethanolamine, sodium hydroxide, potassium hydroxide,
Ammonia and the like can be mentioned. In the present invention, the content of the carboxyl group derived from the component (c) in the hydroxyl group-containing aqueous polyurethane resin is preferably 0.3 to 2.5% by weight based on the weight of the resin, and is preferably 0.5 to 2.5% by weight. More preferably, it is about 2.0% by weight.
When the content of the carboxyl group is less than 0.3% by weight,
Emulsification may be difficult, or emulsion stability may be insufficient. When the content of the carboxyl group exceeds 2.5% by weight, the water resistance of the two-pack type aqueous polyurethane composition may be reduced.

In the present invention, when preparing an isocyanate group-terminated prepolymer, a chain extender (f) can be used, if necessary. Examples of the chain extender used include, for example, low molecular weight polyhydric alcohols such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, pentaerythritol and sorbitol, ethylenediamine, propylenediamine, hexamethylene Examples include diamine, diaminocyclohexylmethane, piperazine, 2-methylpiperazine, isophoronediamine, low molecular weight polyamines such as diethylenetriamine and triethylenetetramine. One of these chain extenders can be used alone, or two or more can be used in combination. In the present invention, (a) an organic polyisocyanate compound, (b) a high molecular weight polyol containing 1 to 40% by weight of dimer diol, (c) a compound having an anionic hydrophilic group and two or more active hydrogens, and If necessary, (f) a urethane prepolymer having an isocyanate group at a terminal is produced using a chain extender. The method for producing the isocyanate group-terminated prepolymer is not particularly limited. For example, the reaction is carried out at a reaction temperature of 40 to 150 ° C. by a conventionally known one-shot method (one-stage method) or a multi-stage isocyanate polyaddition reaction method. It can be carried out.
At this time, if necessary, a reaction catalyst such as dibutyltin dilaurate, stannas octoate, dibutyltin-2-ethylhexoate, triethylamine, triethylenediamine, N-methylmorpholine or the like may be used alone or in combination of two or more. Can be added. Further, an organic solvent which does not react with the isocyanate group can be added at the reaction stage or after the completion of the reaction. Examples of such an organic solvent include acetone, methyl ethyl ketone, toluene, tetrahydrofuran, dioxane,
Examples thereof include dimethylformamide and N-methylpyrrolidone.

In a first embodiment of the present invention, the neutralized isocyanate group-terminated prepolymer is converted into a terminal isocyanate group by using (d) a primary or secondary amine compound having a hydroxyl group in water. Block. In the second embodiment of the present invention, the neutralized product of the isocyanate group-terminated prepolymer is subjected to a chain extension reaction in water using at least one compound selected from (e) a water-soluble polyamine and hydrazine or a derivative thereof. Alternatively, at the same time as the chain elongation reaction, (d) the terminal isocyanate group is blocked using a primary amine or secondary amine compound having a hydroxyl group. By blocking the terminal isocyanate group with a primary or secondary amine compound having a hydroxyl group, the hydroxyl group is introduced into the neutralized product of the prepolymer. Examples of (e) a water-soluble polyamine and hydrazine or a derivative thereof used in the chain extension reaction include ethylenediamine, propylenediamine, hexamethylenediamine, diaminocyclohexylmethane, piperazine, 2-methylpiperazine, isophoronediamine, diethylenetriamine, triethylenetetramine,
Examples thereof include hydrazine, amidoamine derived from diprimary amine and monocarboxylic acid, and monoketimine of diprimary amine. One of these compounds can be used alone, or two or more of them can be used in combination. Examples of the (d) primary amine compound having a hydroxyl group used for blocking the terminal isocyanate group include hydroxylamine, monoethanolamine, 3-amino-1-propanol, and 2-amine.
Amino-2-hydroxymethylpropane-1,3-diol, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, N, N-di-2-
Hydroxyethylethylenediamine, N, N-di-2-
Hydroxypropylethylenediamine, N, N-di-2
-Hydroxypropyl propylene diamine and the like. (D) Examples of the secondary amine compound having a hydroxyl group include N-methylethanolamine, diethanolamine, N, N'-di-2-hydroxyethylethylenediamine, and N, N'-di-2-hydroxypropylethylenediamine. , N, N'-di-2-hydroxypropylpropylenediamine and the like. One of these compounds can be used alone, or two or more of them can be used in combination. Among them, monoethanolamine and diethanolamine can be particularly preferably used. In the present invention, the content of the hydroxyl group derived from the component (d) in the hydroxyl group-containing aqueous polyurethane resin is preferably 0.1 to 5.0% by weight based on the weight of the resin, and is preferably 0.5 to 5.0% by weight. More preferably, it is about 3.0% by weight. When the content of the hydroxyl group is less than 0.1% by weight, the coating film obtained from the two-pack type aqueous polyurethane composition may have insufficient crosslink density and insufficient water resistance. When the content of the hydroxyl group exceeds 5.0% by weight, the liquid stability after the two-liquid preparation is reduced, and there is a possibility that use becomes difficult. When an organic solvent is used in the production of the isocyanate group-terminated prepolymer, it is preferable to block the terminal isocyanate group and then remove the organic solvent by, for example, distillation under reduced pressure. When removing the organic solvent, surfactants such as higher fatty acid salts, resin salts, long chain fatty alcohol sulfates, higher alkyl sulfonates, alkyl aryl sulfonates, sulfonated castor oil, sulfosuccinates It is preferable to use an anionic surfactant such as a nonionic surfactant such as a reaction product of ethylene oxide and a long-chain fatty alcohol or a phenol to maintain emulsifying properties.

The two-part polyurethane composition of the present invention comprises:
(A) The hydroxyl group-containing aqueous polyurethane resin composition of the present invention is used as a main component, and (B) an aqueous polyisocyanate compound is used as a curing agent. The aqueous polyisocyanate compound can be obtained by subjecting a raw material polyisocyanate to an addition reaction of a hydrophilic chain having active hydrogen and, in some cases, a lipophilic chain. It has a long service life and is effective as a curing agent for a hydroxyl group-containing aqueous polyurethane resin composition. As the raw material polyisocyanate, for example, aromatic polyisocyanate, aliphatic polyisocyanate,
Alicyclic polyisocyanates can be mentioned. Also, isocyanurate group-containing polyisocyanate obtained from the reaction of these raw material polyisocyanates,
(B) It can be used as a raw material of an aqueous polyisocyanate compound. As the aromatic polyisocyanate,
For example, phenylene diisocyanate, tolylene diisocyanate, xylene diisocyanate, tetramethyl xylene diisocyanate, naphthylene diisocyanate, diphenylmethane diisocyanate and the isomers thereof can be mentioned. As the aliphatic polyisocyanate and alicyclic polyisocyanate, for example,
Examples thereof include 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and norborane diisocyanate. In addition, as the isocyanurate group-containing polyisocyanate, an isocyanate-terminated compound or a reaction of a raw material polyisocyanate by a reaction of a raw material isocyanate and a compound having active hydrogen, for example, a uretdionation reaction, an isocyanuration reaction, a carbodiimidation reaction, An isocyanate modified product by a uretimination reaction or the like can be given. These isocyanate modified products may be prepared by using known uretdionation catalysts, isocyanuration catalysts and the like, usually in the range of 0 to 9
It can be prepared from the starting polyisocyanate at a reaction temperature of 0 ° C. in the absence of solvents or in the presence of inert solvents customary in the urethane industry. Examples of the uretdionation catalyst and the isocyanuration catalyst include tertiary amines, alkyl-substituted ethylene imines, tertiary alkyl phosphines, metal salts of acetylacetone, and metal salts of various organic acids. These catalysts
One kind may be used alone, or two or more kinds may be used in combination. In addition, examples of the inert solvent include toluene, methyl ethyl ketone, and ethyl acetate. As the raw material polyisocyanate, aliphatic polyisocyanate and alicyclic polyisocyanate have good water dispersibility, stability of isocyanate group after water dispersion, non-yellowing, etc., and can be preferably used. A polyisocyanate having an isocyanurate ring having two or more functional groups can be particularly preferably used.

A nonionic compound or an ionic compound can be used as a compound for adding a hydrophilic chain having active hydrogen used for producing an aqueous polyisocyanate compound. Examples of the nonionic compound include polyoxyalkylene ether alcohols and polyoxyalkylene fatty acid esters. The polyoxyalkylene ether alcohol can be produced by adding an alkylene oxide to a monohydric alcohol. As the monohydric alcohol, any of a linear alcohol, a branched alcohol and a cyclic alcohol can be used, and alcohols having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol and n-butanol are preferably used. Can be used. The polyoxyalkylene fatty acid ester can be produced by adding an alkylene oxide to a fatty acid such as acetic acid, propionic acid and butanoic acid. The polyalkylene oxide chain present in the polyoxyalkylene ether alcohol and the polyoxyalkylene fatty acid ester preferably has an addition mole number of the alkylene oxide of 3 to 90, more preferably 5 to 50. Further, the alkylene oxide chain preferably has an ethylene oxide unit content of 70 mol% or more. Examples of the ionic compound include anionic compounds such as fatty acid salts, sulfonates, phosphates, and sulfates, primary amine salts, secondary amine salts, tertiary amine salts, quaternary ammonium salts, and pyridinium. Cationic compounds such as salts,
Examples include amphoteric compounds such as sulfobetaine. Compounds that add a lipophilic chain having active hydrogen optionally used in the production of an aqueous polyisocyanate compound include, for example, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, myristyl alcohol, Examples thereof include higher alcohols having 8 or more carbon atoms, such as pentadecyl alcohol, cetyl alcohol, and cinnamyl alcohol. In addition, fatty acid esters in which the sum of the carbon number of the fatty acid and the alcohol as the raw materials is 8 or more can also be used. In this case, as a fatty acid as a raw material, for example, α-oxypropionic acid, oxysuccinic acid, dioxysuccinic acid, ε-oxypropane-1,2,
3-tricarboxylic acid, α-hydroxybutyric acid, β-hydroxybutyric acid, hydroxystearic acid, ricinoleic acid, ricinoelaidic acid, ricinostearolic acid, salicylic acid, mandelic acid, and the like.Examples of alcohols include: Examples thereof include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, dodecyl alcohol, lauryl alcohol and the like. By dispersing the aqueous polyisocyanate compound in water, the lipophilic chain as described above is present in the vicinity of the isocyanate group, the isocyanate group is sterically protected from water, and the pot life can be extended. it can. The production of the aqueous polyisocyanate compound used in the present invention can be generally performed at 50 to 130 ° C, and if necessary, an inert solvent, a catalyst, and the like can be used.

The aqueous polyisocyanate compound used in the present invention preferably has an equivalent ratio of active hydrogen of the compound for adding a hydrophilic chain of 1 to 30% based on 1 equivalent of isocyanate group of the polyisocyanate used as a raw material. , 8 to 20%. If the content of the hydrophilic chain is too small, the water dispersibility may be poor. If the content of the hydrophilic chain is too large, the affinity between the aqueous polyisocyanate compound and water becomes strong, and the stability of the aqueous polyisocyanate compound in water may be reduced. Further, based on 1 equivalent of isocyanate group of the polyisocyanate used as a raw material, the equivalent ratio of active hydrogen of the compound for adding a lipophilic chain is preferably 0.1 to 25%, and more preferably 2 to 15%. More preferred. If the content of the lipophilic chain is too small, the surface chemical protection of the isocyanate group cannot be sufficiently performed, and the pot life of the aqueous dispersion may be shortened. If the content of the lipophilic chain is too large, the water dispersion stability may be reduced. In the two-pack type aqueous polyurethane composition of the present invention, the equivalent ratio OH / NCO of (A) the hydroxyl group (OH) of the main agent and (B) the isocyanate group (NCO) of the curing agent composed of the aqueous polyisocyanate compound is 1: 3 ~
2: 1. If the equivalent ratio OH / NCO is less than 1: 3, excess isocyanate groups may react with water to generate carbon dioxide gas, which may impair the appearance of the coating film. Equivalent ratio OH
When / NCO exceeds 2: 1, the crosslinking density required for obtaining sufficient adhesive strength is insufficient, and the hydroxyl groups are exposed, so that the water resistance may be reduced.

The two-part aqueous polyurethane composition of the present invention comprises:
As such, it can be used as an adhesive and a coating agent for various plastic substrates, but if necessary, various surfactants such as fluorine-based or acetylene-glycol-based can be added as a leveling agent. Further, n-methylpyrrolidone, propylene glycol monomethyl ether acetate and the like can be added as a solvent. The two-component aqueous polyurethane composition of the present invention itself has durability, weather resistance, light resistance, and excellent resin physical properties with respect to water resistance, but an aqueous oxazoline-based crosslinking agent, an aqueous (poly) carbodiimide-based crosslinking agent, Further excellent water resistance can be imparted by using a crosslinking agent having a reactivity with a carboxyl group such as an aqueous epoxy resin-based crosslinking agent in combination.
The two-part aqueous polyurethane composition of the present invention, an adhesive,
As various coating agents such as paints and printing inks, it can be suitably used for various plastic base materials such as acrylic resins, ABS resins, polycarbonates, polyurethane resins, and epoxy resins. Even in the case of an adhesive plastic substrate, it shows excellent adhesion, and also has important properties for such a composition such as hot water resistance, alcohol resistance, durability, abrasion resistance, washing resistance, and glossiness. Can meet the demands. The reason why the two-pack type aqueous polyurethane composition of the present invention exerts the above-mentioned effects is as follows. In the hydroxyl group-containing aqueous polyurethane resin composition of the base material, wettability to a poorly adherent plastic substrate, effective for adhesion. It is presumed to have a dimer diol component and to form a high crosslinking density that cannot be obtained by a one-pack type with a curing agent.

[0015]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. In the examples and comparative examples, the evaluation of the coating film was performed on the coating film after the heat treatment by the following method. (1) Transparency Judgment is made visually. ◎: very good, ○: good, Δ: normal, ×: poor. (2) Gloss Determined visually. ◎: very good, ○: good, Δ: normal, ×: poor. (3) Adhesion A cellophane adhesive tape (Nichiban Co., Ltd.) was attached to the painted surface, and the appearance of the coating film after rapidly peeling off at an angle of 60 ° was observed, and evaluated according to the following criteria. A: 95% or more of the coating film remains on the film side. ；: 80% or more and less than 95% of the coating film remain on the film side. Δ: 50% or more and less than 80% of the coating film remain on the film side. X: Less than 50% of the coating film remains on the film side. (4) Hot water resistance After immersing the coated film in hot water of 90 ° C. for 3 hours,
The transparency is evaluated according to the following criteria. ◎: very good, ○: good, Δ: normal, ×: poor. (5) Alcohol resistance The coated film is immersed in ethanol at 20 ° C. for 24 hours, visually observed for swelling and peeling abnormality of the coating film, and evaluated according to the following criteria. ◎: very good, ；: good, Δ: slight abnormality was observed, ×: large abnormality was observed.

Example 1 In a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen inlet tube, 100.0 g of polyhexamethylene carbonate diol (average molecular weight: 2,000), 1,0.0 g,
Hexanediol 1.2 g, dimer diol [Toagosei Co., Ltd., Pespol HP-1000, average molecular weight 57
0] 17.1 g, 2,2-dimethylolpropionic acid 6.
After adding 7 g, 0.001 g of dibutyltin dilaurate and 60 g of methyl ethyl ketone and mixing uniformly, 52.4 g of dicyclohexylmethane diisocyanate was added thereto and reacted at 80 ° C. for 2 hours to obtain a free isocyanate group content of 2.1% by weight based on nonvolatile components. A methyl ethyl ketone solution of the prepolymer was obtained. The solution was cooled to 30 ° C., neutralized by adding 5.0 g of triethylamine, and then emulsified and dispersed by gradually adding 350 g of water. A 6.2% by weight aqueous solution of ethylenediamine was added to the emulsified dispersion.
g, and the mixture was stirred for 0.5 hour, and 8.4 g of diethanolamine was further added and stirred for 2 hours. The solvent was removed while the temperature was raised to 60 ° C. over 2 hours under reduced pressure to obtain a hydroxyl group-containing aqueous polyurethane resin composition having a solid content of about 35% by weight. In this composition, the content of carboxyl groups derived from 2,2-dimethylolpropionic acid in the polyurethane resin was 1.2% by weight, and the content of hydroxyl groups was 1.5% by weight. Example 2 In a reactor similar to that used in Example 1, 68.0 polybutylene adipate diol (average molecular weight 1,700) was 68.0.
g, dimer diol [Toagosei Co., Ltd., Pespol HP
-1000, average molecular weight 570] 22.8 g, ethylene glycol 0.6 g, 2,2-dimethylolbutanoic acid 7.
4 g, 0.001 g of dibutyltin dilaurate and 60 g of methyl ethyl ketone were added and mixed uniformly, and 44.6 g of isophorone diisocyanate was added.
The reaction was carried out for an hour to obtain a prepolymer having a free isocyanate group content of 2.5% by weight based on the nonvolatile content in methyl ethyl ketone. The solution was cooled to 30 ° C., neutralized by adding 5.0 g of triethylamine, and then emulsified and dispersed by gradually adding 350 g of water. 1.6 g of a 60% by weight aqueous solution of hydrazine hydrate and 8.4 g of diethanolamine were added to this emulsified dispersion and stirred for 2 hours. The solvent was removed while the temperature was raised to 60 ° C. over 2 hours under reduced pressure to obtain a hydroxyl group-containing aqueous polyurethane resin composition having a solid content of about 35% by weight. The carboxyl group content derived from 2,2-dimethylolbutanoic acid in the polyurethane resin in this composition was 1.5% by weight, and the hydroxyl group content was 1.8% by weight.

Example 3 In the same reactor as used in Example 1, poly-ε-
Caprolactone diol (average molecular weight 2,000) 80.
0 g, polyethylene glycol (average molecular weight: 1,000
0) 10.0 g, 2.7 g of 1,4-butanediol, dimer diol [Toagosei Co., Ltd., Pespol HP-100]
0, average molecular weight 570] 5.7 g, 2,2-dimethylolpropionic acid 6.7 g, dibutyltin dilaurate 0.00
After adding 1 g and 60 g of methyl ethyl ketone and mixing uniformly, 44.6 g of isophorone diisocyanate was added and reacted at 80 ° C. for 2 hours to obtain a prepolymer methyl ethyl ketone solution having a free isocyanate group content of 2.5% by weight based on the nonvolatile content. Was. The solution was cooled to 30 ° C., neutralized by adding 5.0 g of triethylamine, and then emulsified and dispersed by gradually adding 350 g of water. 3.3 g of a 60% by weight aqueous solution of hydrazine hydrate is added to the emulsified dispersion.
Was added and the mixture was stirred for 0.5 hour, and then 4.2 g of diethanolamine was added and the mixture was stirred for 2 hours. The solvent was removed while the temperature was raised to 60 ° C. over 2 hours under reduced pressure to obtain a hydroxyl group-containing aqueous polyurethane resin composition having a solid content of about 35% by weight. In this composition, the content of carboxyl groups derived from 2,2-dimethylolpropionic acid in the polyurethane resin was 1.4% by weight, and the content of hydroxyl groups was 0.9% by weight. Example 4 In the same reactor as used in Example 1, poly-3-
Methylpentane adipate (average molecular weight 2,000) 8
0.0 g, polypropylene glycol (average molecular weight 1.0
00) 10.0 g, ethylene glycol 1.2 g, dimer diol [Toagosei Co., Ltd., Pespol HP-100]
0, average molecular weight 570] 11.4 g, 2,2-dimethylolpropionic acid 6.7 g, dibutyltin dilaurate 0.0
After adding 01 g and 60 g of methyl ethyl ketone and mixing uniformly, 52.4 g of dicyclohexylmethane diisocyanate was added and reacted at 80 ° C. for 2 hours. A methyl ethyl ketone solution of a prepolymer having a free isocyanate group content of 2.4% by weight based on the nonvolatile content was prepared. Obtained. The solution was cooled to 30 ° C., neutralized by adding 5.0 g of triethylamine, and then emulsified and dispersed by gradually adding 350 g of water. 12.6 g of diethanolamine was added to this emulsified dispersion.
, And stirred for 2 hours.
The solvent was removed while the temperature was raised to 0 ° C. to obtain a hydroxyl group-containing aqueous polyurethane resin composition having a solid content of about 35% by weight. 2,2 in the polyurethane resin in this composition
The content of carboxyl groups derived from 2-dimethylolpropionic acid was 1.4% by weight, and the content of hydroxyl groups was 2.
It was 5% by weight.

Comparative Example 1 Polyhexamethylene carbonate diol (average molecular weight: 2,000) was placed in a reactor similar to that used in Example 1.
0) 100.0 g, 4.7 g of 1,6-hexanediol,
6.7 g of 2,2-dimethylolpropionic acid, 0.001 g of dibutyltin dilaurate and 60 of methyl ethyl ketone
g, and uniformly mixed. Then, 52.4 g of dicyclohexylmethane diisocyanate was added and reacted at 80 ° C. for 2 hours to obtain a prepolymer methyl ethyl ketone solution having a free isocyanate group content of 2.3% by weight based on nonvolatile components. The solution was cooled to 30 ° C., neutralized by adding 5.0 g of triethylamine, and then emulsified and dispersed by gradually adding 350 g of water. After adding 18.0 g of a 20% by weight aqueous solution of ethylenediamine to this emulsified dispersion and stirring for 2 hours, the solvent was removed while heating to 60 ° C. over 2 hours under reduced pressure to obtain a solid content of about 35% by weight. Thus, an aqueous polyurethane resin composition was obtained. The carboxyl group content derived from 2,2-dimethylolpropionic acid in the polyurethane resin in this composition was 1.3% by weight. Comparative Example 2 85.0 of polybutylene adipate diol (average molecular weight 1,700) was added to a reactor similar to that used in Example 1.
g, dimer diol [Toagosei Co., Ltd., Pespol HP
-1000, average molecular weight 570] 11.4 g, ethylene glycol 1.2 g, 2,2-dimethylolpropionic acid 6.7 g, dibutyltin dilaurate 0.001 g and methyl ethyl ketone 60 g were added, and after uniform mixing, isophorone diisocyanate 44 was added. After adding 0.6 g, the mixture was reacted at 80 ° C. for 2 hours to obtain a prepolymer having a free isocyanate group content of 2.4% by weight based on the nonvolatile matter in methyl ethyl ketone. The solution was cooled to 30 ° C., neutralized by adding 5.0 g of triethylamine, and then 350 g of water.
Was gradually added to emulsify and disperse, and 5.0 g of a 60% by weight aqueous solution of hydrazine hydrate was added thereto, followed by stirring for 2 hours. The solvent was removed while raising the temperature to 60 ° C. over 2 hours under reduced pressure to obtain an aqueous polyurethane resin composition having a solid content of about 35% by weight. 2,2 in the polyurethane resin in this composition
The carboxyl group content derived from 2-dimethylolpropionic acid was 1.5% by weight. Comparative Example 3 A reaction apparatus similar to that used in Example 1 was charged with poly-ε-
Caprolactone diol (average molecular weight 2,000) 10
0.0 g, polyethylene glycol (average molecular weight: 1,000
0) 10.0 g, 2,2-dimethylolpropionic acid 6.
After adding 7 g, 2.7 g of 1,4-butanediol, 0.001 g of dibutyltin dilaurate and 60 g of methyl ethyl ketone and mixing uniformly, 52.4 g of dicyclohexylmethane diisocyanate was added, and the mixture was reacted at 80 ° C. for 2 hours. A prepolymer having a free isocyanate group content of 2.2% by weight in methyl ethyl ketone was obtained. The solution was cooled to 30 ° C., neutralized by adding 5.0 g of triethylamine, and then emulsified and dispersed by gradually adding 350 g of water. To this emulsified dispersion was added 6.2 g of a 20% by weight aqueous solution of ethylenediamine, and the mixture was stirred for 0.5 hour.
Stirred for hours. The solvent was removed while the temperature was raised to 60 ° C. over 2 hours under reduced pressure to obtain a hydroxyl group-containing aqueous polyurethane resin composition having a solid content of about 35% by weight. The carboxyl group content derived from 2,2-dimethylolpropionic acid in the polyurethane resin in this composition was 1.2% by weight, and the hydroxyl group content was 1.5% by weight.

Example 5 11.3 g of an aqueous polyisocyanate compound [Sumitomo Bayer Urethane Co., Ltd., Bihidur 3100, 17.2% by weight of NCO] containing 100 g of the hydroxyl group-containing aqueous polyurethane resin composition obtained in Example 1 as a main component. Was blended as a curing agent and stirred until uniform to prepare a coating liquid. The equivalent ratio OH / NCO of the hydroxyl group in the main agent and the isocyanate group in the curing agent is 2: 3. This coating solution was applied onto a discharge-treated surface of a biaxially oriented polypropylene film (OPP) having a thickness of 20 μm and subjected to a corona discharge treatment and one surface of a biaxially oriented polyethylene terephthalate film (PET) having a thickness of 11 μm with a bar coater (No. 8), and dried for 5 days at a temperature of 25 ° C. and a relative humidity of 65% using a thermo-hygrostat to obtain a coated film. The coating thickness was 10 μm in each case. The obtained coated film was further heated at 60 ° C. and a relative humidity of 0% with a thermo-hygrostat at 3%.
After heat treatment for an hour, evaluation was performed. Both transparency and gloss were very good. In the adhesion test, all of the coating remained on the film side for the polypropylene film, and 90% of the coating remained on the film side for the polyethylene terephthalate film. In the hot water resistance test, there was no change in the transparency of the coating film. In the alcohol resistance test, there was no change in the appearance of the coating film. Example 6 13.6 g of an aqueous polyisocyanate compound [Sumitomo Bayer Urethane Co., Ltd., Bihidur 3100, NCO 17.2% by weight] was used as a curing agent with 100 g of the hydroxyl group-containing aqueous polyurethane resin composition obtained in Example 2 as a main component. A coating liquid was prepared in the same manner as in Example 5 except that the composition was blended as above, and the coating film was evaluated. In addition, the equivalent ratio OH / of the hydroxyl group in the main agent and the isocyanate group in the curing agent was used.
The NCO is 2: 3. Both transparency and gloss were very good. In the adhesion test, both the polypropylene film and the polyethylene terephthalate film all remained on the film side. In the hot water resistance test, there was no change in the transparency of the coating film. In the alcohol resistance test, there was no change in the appearance of the coating film.

Example 7 6.8 g of an aqueous polyisocyanate compound (Sumitomo Bayer Urethane Co., Ltd., Bihidur 3100, NCO 17.2% by weight) was used as a main component, with 100 g of the hydroxyl group-containing aqueous polyurethane resin composition obtained in Example 3 as a main component. Was prepared in the same manner as in Example 5 except that was added as a curing agent, and the coating film was evaluated. The equivalent ratio OH / N of the hydroxyl group in the main agent and the isocyanate group in the curing agent was used.
CO is 2: 3. Both transparency and gloss were very good. In the adhesion test, 90% of the coating film remained on the film side for the polypropylene film, and 85% of the coating film remained on the film side for the polyethylene terephthalate film. In the hot water resistance test, there was no change in the transparency of the coating film. In the alcohol resistance test, there was no change in the appearance of the coating film. Example 8 18.8 g of an aqueous polyisocyanate compound [Sumitomo Bayer Urethane Co., Ltd., Bihidur 3100, NCO 17.2% by weight] was used as a curing agent, using 100 g of the hydroxyl group-containing aqueous polyurethane resin composition obtained in Example 4 as a main component. A coating liquid was prepared in the same manner as in Example 5 except that the composition was blended as above, and the coating film was evaluated. In addition, the equivalent ratio OH / of the hydroxyl group in the main agent and the isocyanate group in the curing agent was used.
The NCO is 2: 3. Both transparency and gloss were very good. In the adhesion test, all of the coating remained on the film side for the polypropylene film, and 85% of the coating remained on the film side for the polyethylene terephthalate film. In the hot water resistance test, there was no change in the transparency of the coating film. In the alcohol resistance test, there was no change in the appearance of the coating film.

Comparative Example 4 The aqueous polyurethane resin composition obtained in Comparative Example 1 was used as a one-pack type coating liquid, and the corona discharge treated surface of the biaxially stretched polypropylene film and the biaxial A coating film was formed on one side of the stretched polyethylene terephthalate film and evaluated. The transparency was normal, but the gloss was good. In the adhesion test, 35% of the coating film remained on the film side for the polypropylene film, and 20% of the coating film remained on the film side for the polyethylene terephthalate film. In the hot water test, the transparency of the coating film was almost lost. In the alcohol resistance test,
Swelling occurred in various parts of the coating film, and part of the coating film was peeled off. Comparative Example 5 Using the aqueous polyurethane resin composition obtained in Comparative Example 2 as a one-pack type coating liquid, the corona-discharge treated surface of a biaxially stretched polypropylene film and biaxially stretched polyethylene terephthalate in the same manner as in Example 5. An evaluation was performed by forming a coating film on one side of the film. Both transparency and gloss were good. In the adhesion test, 75% of the coating remained on the film side for the polypropylene film, and 40% of the coating remained on the film side for the polyethylene terephthalate film. In the hot water test, the transparency of the coating film was almost lost. In the alcohol resistance test, swelling and peeling were observed in a part of the coating film. Comparative Example 6 Using as a main component 100 g of the hydroxyl group-containing aqueous polyurethane resin composition obtained in Comparative Example 3, 11.3 g of an aqueous polyisocyanate compound [Sumitomo Bayer Urethane Co., Ltd., Bihidur 3100, NCO 17.2% by weight] as a curing agent A coating liquid was prepared in the same manner as in Example 5 except that the composition was blended as above, and the coating film was evaluated. In addition, the equivalent ratio OH / of the hydroxyl group in the main agent and the isocyanate group in the curing agent was used.
The NCO is 2: 3. Both transparency and gloss were good. In the adhesion test, 85% of the coating remained on the film side for the polypropylene film, and 70% of the coating remained on the film side for the polyethylene terephthalate film. In the hot water test, the coating film was slightly cloudy. In the alcohol resistance test, a small part of the coating film peeled off. Examples 5 to 8 and Comparative Examples 4 to
Table 1 shows the results of No. 6.

[0022]

[Table 1]

As shown in Table 1, a coating liquid prepared from a two-pack type polyurethane composition using a curing agent comprising a hydroxyl group-containing aqueous polyurethane resin composition of the present invention and an aqueous polyisocyanate compound was applied. The coatings obtained in Examples 5 to 8 have very good transparency, gloss, hot water resistance, and alcohol resistance, and generally have excellent adhesion to poorly adhesive polypropylene films and polyethylene terephthalate films. Is shown. On the other hand, the coating film of Comparative Example 4 using the aqueous polyurethane resin composition of Comparative Example 1 which did not use dimer diol as a diol component and did not end-block with diethanolamine as a one-pack coating solution, The coating film of Comparative Example 5 in which the aqueous polyurethane resin composition of Comparative Example 2 in which the end blocking was not performed was used as a one-pack type coating liquid did not have very good appearance, and had a poor adhesion to a polypropylene film. Adhesion to polyethylene terephthalate film is poor, and hot water resistance and alcohol resistance are extremely poor. In addition, the coating film of Comparative Example 6 using the hydroxyl group-containing aqueous polyurethane resin composition of Comparative Example 3 in which terminal blocking with diethanolamine was performed but no dimer diol was used also had appearance, adhesion, hot water resistance, and alcohol resistance. Both are somewhat inferior.

[0024]

The two-package aqueous polyurethane composition of the present invention comprises a hydroxyl group-containing aqueous polyurethane resin composition containing dimer diol in the raw material as a main component, and when applied to a poorly adhesive plastic film,
Shows excellent adhesiveness, and shows a hot water resistance by forming a highly cross-linked structure using a curing agent composed of an aqueous polyisocyanate compound. A wide range of development is possible as a water-based paint and water-based ink.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 175/04 C09D 175/04 C09J 175/04 C09J 175/04 (72) Inventor Shinichi Umetani Fukui City, Fukui Prefecture 4-23-1, Bunkyo Nikka Kagaku Co., Ltd. F-term (reference) 4J002 CK02W CK03X CK04X FD140 FD310 GH00 GJ01 4J034 BA03 CB03 CB07 CC03 CC15 CC23 CC26 CC45 CC52 CC54 CD04 DA01 DB03 DB08 DC50 DF01 DF02 DL03 HA02 HC03 HC12 HC17 HC22 HC46 HC52 HC54 HC61 HC71 HC73 HD05 HD07 JA41 JA42 RA07 RA08 4J038 DG051 DG081 DG111 DG121 DG131 DG261 DG271 NA04 NA11 NA14 PC08 4J040 EF061 EF081 EF111 EF121 EF131 EF07 LA09 HC08

Claims (9)

[Claims] (A) an organic polyisocyanate compound,
(B) a high molecular weight polyol containing 1 to 40% by weight of dimer diol and (c) a neutralized product of an isocyanate group-terminated prepolymer obtained by reacting a compound having two or more active hydrogens with an anionic hydrophilic group. A hydroxyl group-containing aqueous polyurethane resin composition obtained by blocking a terminal isocyanate group with a (d) primary amine or secondary amine compound having a hydroxyl group in water. (2) (a) an organic polyisocyanate compound,
(B) a high molecular weight polyol containing 1 to 40% by weight of dimer diol and (c) a neutralized product of an isocyanate group-terminated prepolymer obtained by reacting a compound having two or more active hydrogens with an anionic hydrophilic group. (E) after a chain extension reaction in water using at least one compound selected from a water-soluble polyamine and hydrazine or a derivative thereof, or simultaneously with the chain extension reaction, (d) a primary amine having a hydroxyl group Alternatively, a hydroxyl group-containing aqueous polyurethane resin composition obtained by blocking a terminal isocyanate group using a secondary amine compound. 3. The method according to claim 1, wherein (a) the organic polyisocyanate compound is
The hydroxyl group-containing aqueous polyurethane resin composition according to claim 1 or 2, which is at least one selected from an aliphatic diisocyanate compound and an alicyclic diisocyanate compound. 4. The high molecular weight polyol (b) contains at least one of polyester polyol, polycarbonate polyol and polyether polyol as a component other than dimer diol at a ratio of 10 to 94% by weight. The hydroxyl group-containing aqueous polyurethane resin composition according to the above. 5. The compound (c) having an anionic hydrophilic group and two or more active hydrogens, wherein the anionic hydrophilic group is a carboxyl group and the content of the carboxyl group in the hydroxyl group-containing aqueous polyurethane resin is 3. The composition according to claim 1, wherein the content is 0.3 to 2.5% by weight based on the weight of the resin.
The hydroxyl group-containing aqueous polyurethane resin composition according to the above. 6. The hydroxyl group-containing primary amine or secondary amine compound is monoethanolamine or diethanolamine, and the content of hydroxyl groups in the hydroxyl group-containing aqueous polyurethane resin is as follows: The hydroxyl group-containing aqueous polyurethane resin composition according to claim 1 or 2, wherein the amount is from 0.1 to 5.0% by weight based on the weight. 7. An equivalent ratio OH / NCO of (A) a hydroxyl group (OH) of a main agent and (B) an isocyanate group (NCO) of a curing agent comprising an aqueous polyisocyanate compound.
In the two-pack type aqueous polyurethane composition blended in a ratio of 1: 3 to 2: 1, the main component (A) is defined as claim 1, claim 2,
A two-pack type aqueous polyurethane composition which is the hydroxyl group-containing aqueous polyurethane resin composition according to claim 3, 4, 5, or 6. 8. An adhesive comprising the two-component aqueous polyurethane composition according to claim 7. 9. A coating composition comprising the two-component aqueous polyurethane composition according to claim 7.