JPH04189813A - Method for preparing novel polyurethane aqueous dispersion - Google Patents

Abstract

PURPOSE:To prepare the subject dispersion useful as a treating agent for synthetic leather products, adhesives, coatings, paints or ink vehicles by reacting a specific amino acid group-containing polymer with a blocked isocyanate group- containing prepolymer in a state dispersed in water. CONSTITUTION:An amino group-containing polymer obtained by reacting a polyepoxy compound (preferably epichlorohydrin-bisphenol A type epoxy resin) with a polyamine compound (e.g. ethylenediamine or triethylenetetramine) and (B) a blocked isocyanate group-containing prepolymer (preferably a prepolymer having isocyanate groups and carboxyl groups and giving a stable aqueous dispersion) are dispersed in water and reacted with each other to provide the objective dispersion.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is directed to the production of a novel high molecular weight polyurethane aqueous dispersion useful as a vehicle for treating textiles, synthetic leather products, adhesives, coatings, paints, and inks. More specifically, the present invention relates to a method for producing a one-component polyurethane aqueous dispersion using an epoxy resin having at least two or more oxirane rings in the molecule.

(Prior art) In recent years, there has been increasing interest in water-based resins as an alternative to conventional organic solvent-based resins from the viewpoint of pollution and environmental contamination. , for example, JP-B-49-16601, JP-A-47-11938, or Fiber, 27.481 (1
In addition to its use as a treatment agent for artificial leather and fibers, such as those listed in 975), it has been used in a wide range of fields, such as as a vinyl chloride base material, or as an adhesive for plasti and kufilm.

However, the adhesion to the surface of inorganic compounds mainly composed of metals is still insufficient, and epoxy resins have an advantage in this field. For this reason, is an aqueous polyurethane dispersion using an epoxy resin that has both the adhesive properties of an epoxy resin and the excellent mechanical properties of a polyurethane resin being considered? Although it is known that it can be used as a two-component type, due to the polyfunctionality of epoxy resin and the high reactivity of isocyanate groups, it can be used in an aqueous system. A satisfactory liquid has not been obtained.

(Problems to be Solved by the Invention) The present invention provides a method for producing a one-component urethane-epoxy resin that has excellent adhesion to surfaces such as metals, especially inorganic compounds, and has excellent mechanical properties. .

(Means for Solving the Problems) The present invention involves dispersing in water a polymer containing amine 7 groups and a prepolymer containing a protoisomer atom group, which are obtained by reacting a polyepoxy compound and a polyamine compound. , followed by a reaction.

As the polyepoxy compound used in the present invention,
Epoxy resin having at least two or more bull/ran rings in the molecule, for example, shrimp chlorohydrin-bisfuninol A type epoxy represented by / -0-CH, -CH-CH2, \O' Resins, novolac type epoxy resins represented by these, cycloaliphatic epoxy resins represented by these, timer acid-based diglycidyl esters, and organic solvent solutions thereof are exemplified. Particularly preferred is bisphenol A epoxy resin.

In the present invention, an amide 7 group-containing polymer is prepared by reacting the above-mentioned polyepoquine compound with a polyamine compound in excess of the stoichiometric amount. Examples of the polyamine compound used in the present invention include ethylenediamine, 1,
2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2-methylbiperazine, 2,5-dimethylpiperazine, inphorondiamine, 4. 4'-
Synchhexylmethanediamine, 3. 3'-methyl-4,4'-synchrohexylmethanediamine,
Examples include diaminos such as 1.4-cyclohexanediamine; polyamines such as diethylenetriamine, dipropylenetriamine, and triethylenetetramine; hydrazines, and ammonia.8 These may be used alone or in combination.

The reaction between a polyepoxy compound and a polyamine compound usually proceeds relatively quickly with heat generation.

Therefore, it is generally obtained by gradually dropping the polyepoxy compound alone or its organic solvent solution into an organic solvent solution containing the polyamine compound.

In the present invention, a homogeneous solution is prepared by mixing the obtained amino group-containing polymer with a blocked isocyanate group-containing prepolymer.

Blocked isocyanate group-containing prepolymers include prepolymers that have carboxyl groups that are relatively unreactive with isocyanate groups and that can form a salt of carboxyl groups in a sufficient amount to form a stable aqueous dispersion. It may be a polymer and may not contain a carboxyl group. When it has carboxyl groups, a soap-free aqueous polyurethane dispersion can be obtained by forming a salt, and when it does not contain carboxyl groups, it is possible to create a stable aqueous dispersion using an emulsifier aqueous solution.

The blocked isocyanate group-containing prepolymer used in the present invention is produced by reacting a polyol component with an organic diisocyanate compound in excess of the stoichiometric amount, and then reacting the remaining isocyanate groups with an isocyanate blocking agent. preferable. Suitable polyol components are generally linear and have an average molecular weight of 300 to 2.
0,000, preferably 500 to 4,000.

Such compounds may include polyhydroxy compounds containing terminal hydroxyl-, carboxyl-, amino-9- or mercapto-groups, such as polyesters, polyacetals, polyethers, polythioethers, polyamides and polyesteramides. .

Examples of polyester polyols include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-bentanediol, 3-methyl-1,5-bentanediol, 1,6-hexanediol, Neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol (molecular weight 300~
6゜000), dipropylene glycol, tripropylene glycol, bishydroxyethoxy-benzene, 1
, 4-cyclobenzenediol, 1,4-cyclobenzenedimetatool, bisphenol A1 hydrogenated bisphenol A1 hydroquinone and their alkylene oxide adducts and other glycol components, succinic acid, adipic acid, azelaic acid, sebacin Acid, dodecanedicarboxylic acid, maleic anhydride, Fumar L 1.3-cyclobencundicarboxylic acid, 1.4-cyclohedoxanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1.4-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, naphthalic acid, biphenyl dicarboxylic acid, 1,2-bis(phenoloxy)ethane-p, p'-dicarboxylic acid and anhydrides of these dicarboxylic acids or Ester-forming derivatives: In addition to polyesters obtained by dehydration condensation reaction with acid components such as p-hydroquine benzoic acid, p-(2-hydroxy7ethoxy)benzoic acid, and ester-forming derivatives of these hydroxycarboxylic acids, ε -Polyesters obtained by ring-opening polymerization reactions of cyclic ester compounds such as caprolactone and copolyesters thereof can be mentioned.

Examples of the polyether include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hebosanediol, neopentyl glycol, glycerin, Trimethylolethane, trimethylolpropane, sorbitol, sucrose, aconite sugar, trimellitic acid, hemimellitic acid, phosphoric acid, ethylenediamine, diethylenetriamine, triisopropaturamine, pyrogallol, dihydroquine benzoic acid, hydroxyphthalic acid, l.

Ethylene oxide, propylene oxide,
Examples include those obtained by addition polymerization of one or more monomers such as butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, cyclohexylene, etc. by a conventional method.

Examples of polycarbonate polyols include compounds obtained by reacting glycols such as 1,4-butanediol, 1,6-hebosanediol, and diethylene glycol with diphenyl carbonate and phosgene.

Other polyhydroxy compounds containing urethane groups or urea groups, as well as natural polyols, including those optionally modified, such as castor oil and carbohydrates, can also be used. The active hydrogen-containing compound of the present invention having an average molecular weight of 1,300 to 20,000 is prepared by mixing a high molecular weight polyol and a low molecular weight compound having a molecular j of 1,300 or less.
Of course, it is also possible to set it to 0000. Suitable low-molecular weight compounds include compounds containing at least two or more active hydrogens in molecules of 11,300 or less, such as glycol components used as raw materials for polyester polyols;
Examples include polyhydroquine compounds such as glycerin, trimethylolethane, trimethylolpropane, sorbitol, and bentaeryswattol.

Examples of the organic polyisocyanate compound used in the method of the present invention include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-'phenylene diisocyanate, p-phenylene diisocyanate, 4. 4'-phenylmethane diisocyanate, 2. 4"-7 phenylmethane diisocyanate, 2,2"-diphenylmethane diisocyanate, 3
．． 3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3"-dimethoxy-4,4'-
Biphenylene diisocyanate, 3,3'-dichloro-
4,4″-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate , trimethylhexamethylene diisocyanate, 1.
lylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, inphorone diisocyanate, 4. 4'-dicyclohexylmethane diisocyanate, 3,3'-dimethyl-4゜4'
-dicyclohexylmethane diisocyanate and the like.

In order to disperse the prepolymer in water, a salt-forming group that becomes a hydrophilic group is contained in the prepolymer, or an emulsifier is used in combination. A method for introducing a hydrophilic group into a hydrophilic group-containing isocyanate-terminated prepolymer is to use a prepolymer that has at least one active hydrogen in its molecule and contains a carboxyl group, a sulfonic acid group, a sulfonate group, or a repeating unit of ethylene oxide. At least one hydrophilic group-containing compound
It can be obtained by copolymerizing two or more species during the production of a prepolymer. Such hydrophilic group-containing compounds include, for example, 2
-oxyethanesulfonic acid, phenolsulfonic acid, sulfobenzoic acid, sulfoconolyric acid, 5-sulfoisophthalic acid, sulfanilic acid, 1, 3-phenylenediamine-4,6-disulfonic acid, 2. 2. Sulfonic acid-containing compounds such as 4-diaminotoluene-5-sulfonic acid and derivatives thereof or polyester polyols obtained by copolymerizing these; 2,2-dimethylolpropionic acid;
2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid,
Geo-bovine cymaleic acid, 2,6-dio-bovine cybenzoic acid, 3,
Carboxylic acid-containing compounds such as 4-diaminobenzoic acid, derivatives thereof, or polyester polyols obtained by copolymerizing these: Contains at least 30% by weight of repeating units of ethylene oxide, and contains at least one active hydrogen in the polymer. Molecules containing j1300-10
Examples include nonionic group-containing compounds such as polyethylene-polyalkylene copolymers of 1,000 °C, and polyester polyether polyols obtained by copolymerizing these, which can be used alone or in combination, but are preferred hydrophilic compounds in the present invention. The group-containing compound is a carboxyl group-containing compound, a derivative thereof, or a polyester polyol obtained by copolymerizing these. In addition, as an emulsifier to be used in combination, nonionic emulsifiers such as HLB or 16-18 polyoxine ethylene nonylphenol ether, polyoxine ethylene-oxine propylene brosoc copolymer, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, etc. Anionic emulsifiers such as are preferred.

The polyurethane aqueous dispersion in the present invention contains an active hydrogen-containing compound having an active hydrogen atom reactive with at least two isocyanate groups in the molecule and having an average molecular jt of 300 to 20,000, and an active hydrogen-containing compound having an average molecular jt of 11,300 or less. A prepolymer having an isocyanate group at the end is prepared by reacting a hydrophilic group-containing compound with an organic boisocyanate compound. At this time, the amount of the organic polyisonanate compound used is determined by the amount of active hydrogen containing reactive with the isocyanate group. Equivalent ratio of 1°2 to the amount of compound used
2.5, preferably 1.5-2. Used at a rate of 0. Amount of organic polyisocyanate compound used (equivalent ratio)
If it is less than 1.2, the prepolymer tends to thicken significantly, making it difficult to make it water-based, which is not preferable. On the other hand, if it exceeds 2.5, the dispersibility of the final product polyurethane resin in water tends to decrease, which is not preferable.

In the present invention, the thus obtained prepolymer having isocyanate groups at its terminals is then blocked using an isocyanate blocking agent. Conventionally known in/anate blocking agents can be used. Oximes such as formaldoxime, acetaldoxime, propionaldoxime, butyraldoxime, benzaldoxime, acetophenone oxime, methyl ethyl ketoxime, cyclohexanone oxime, phenol, ortho-chlorophenol, meta-cresol, etc. Examples include phenols, lactams such as epsilon-caprolactam, and compounds such as diethyl malonate. Particularly preferred are oximes represented by methyl ethyl ketoxime. Usually a prepolymer with an isocyanate group at the end
Blocking with an anate blocking agent is carried out using a stoichiometric amount or a slight excess of the blocking agent.

The isocyanate group-blocked prepolymer is prepared using an organic compound that is inert to isocyanate groups, such as dioxane, acetone, methyl ethyl ketone, acetonitrile, ethyl acetate, tetrahydrofuran, toluene, or xylene, in order to uniformly carry out the two reactions. A solvent is used. Usually 20 to 10 based on prepolymer solid content
An amount of 0% (wt%) is used. When the amount of organic solvent is less than 20% based on the solid content of the prepolymer, the viscosity of the prepolymer solution tends to become too high and water dispersion becomes difficult, which is not preferable. Furthermore, if the amount of organic solvent is more than 100% based on the solid content of the prepolymer, the water dispersibility will not be improved even if the amount of organic solvent is increased further.
Furthermore, it is uneconomical because the amount of solvent removed increases.

In the present invention, the obtained block German/anate group-containing prepolymer is mixed with the amine 7 group-containing polymer and then dispersed in water. In this case, conventionally known polyamine compounds can also be used in combination within a range that does not impair the effects of the amino group-containing polymer. Examples of such polyamine compounds include ethylenediamine, 1,2-
Propanediamine, 1,6-hemethylenediamine,
Diamines such as piperazine, 25-dimethylpiperazine, inphorondiamine, 4,4'-dinochlorohexylmethanediamine, 3,3''-dimethyl-4,4'-dicyclohexylmethanediamine, I+ 4-cyclohexylsandiamine, etc. ; Polyamines such as diethylenetriamine, dipropylenetriamine, triethylenetetramine;
Examples include hydrazines and acid hydrazides, which may be used alone or in combination.

In the present invention, the amount of the amino group-containing polymer to be used with respect to the blocked isocyanate group-containing prepolymer is the amount of the amine group-containing polymer and other polyamine compound (both of which are used for chain elongation) per equivalent of the blocked isocyanate group of the prepolymer. (used as an agent) or 0. It is limited to a range of 7 to 1.1 equivalent. When the amount of amine groups is within the above range, the strength of the film from the aqueous polyurethane dispersion obtained is high, and the storage stability of the aqueous polyurethane dispersion obtained is also excellent.

The amount of water used to water-disperse the mixed solution of the blocked isocyanate group-containing prepolymer and the amino group-containing polymer is not particularly limited, but the weight ratio of the final polyurethane polymer is water. It is generally preferred that the amount be about 20-40% after dispersion. The mixed liquid may be dispersed in water by adding water dropwise to the mixed liquid to form a phase inversion emulsification, or by dispersing the mixed liquid into well-stirred water. may be dripped. Alternatively, a preferable method is to perform water dispersion while applying mechanical shearing force using a homokenizer, colloid mill, or the like. Furthermore, a method using ultrasonic waves during water dispersion is also preferred. In water dispersion, if the polymer side chain of the blocked isocyanate group-containing prepolymer has carboxyl acid or sulfonic acid groups, an alkali salt can be formed and a soap-type dispersion can be obtained. If there is no such hydrophilic group, an emulsifier is used to disperse the material in water. The thus obtained blocked isocyanate group-containing prepolymer containing an organic solvent and Ami 7
The aqueous dispersion of the mixed solution of the group-containing polymer is then stirred for several hours, preferably at a temperature below 95°C, to carry out the deblocking reaction.

The deblocking reaction varies depending on the type of blocking agent.
It is usually completed in 3 to 5 hours at 70 to 80°C. After the deblocking reaction is completed, in order to remove the contained organic solvent and the produced bloating agent, under reduced pressure conditions,
Azeotropically removed with water.

The polyurethane aqueous dispersion obtained by the method of the present invention is
It has excellent adhesion to metal surfaces, especially inorganic compound surfaces, and excellent mechanical properties.

In addition, it is possible to obtain a good coating film by using spray painting, roll coating, etc. The aqueous polyurethane dispersion produced by the method of the present invention has excellent coating properties, especially on inorganic substances such as metals, and can be used in many applications to which conventional aqueous polyurethane dispersions could not be applied.For example, ink, automobile paint, etc. Vehicles for commercial and household paints, glass plastics, textiles, paper, leather, wood,
It can be used in a wide range of applications, including metal coating, thin film coating on fibers and textiles, surface coating for fur, and various adhesives.

(Examples) Next, the present invention will be further explained by examples. In addition, parts and percentages in the examples are based on weight unless otherwise specified.

Example I A. Prepolymer Preparation In a four-necked flask equipped with a thermometer, stirrer, and reflux condenser, 500 parts of poly(oxypropylene) glycol
Molecular weight: 1,000), 7,241 parts of 7-chlorohexanedimethanol, and 67.1 parts of dimethylolpropionic acid were added, and the mixture was heated at 100° C. for 20 minutes under high vacuum to remove moisture. It was cooled to 75° C. in a dry nitrogen atmosphere and 800 parts of methyl ethyl ketone was added. This solution was further cooled to 30°C and 4°4-diphenylmethane diisocyanate 562.5
Added a section. The mixture was gradually heated using heat generation and maintained at 70°C for 3 hours. The NCO content of the obtained prepolymer was 3.14% and the acid value was 14.0. While maintaining the same temperature, 130.5 parts of methyl ethyl ketoxime was added dropwise.

B. Production of polyamine 615 parts of methyl ethyl ketone was processed into a four-bottle flask equipped with a thermometer, a stirrer, and a reflux condenser, and then 150 parts of 2-methylbiperazine was dissolved, and then heated to 50°C to prepare a bisphenol A type epoxy with epoxy fi515. resin 77
2.5 parts were gradually added over 1 hour. After the addition was completed, the solution was maintained at the same temperature for 2 hours to obtain a Botamine solution with an amine equivalent of 615 (solid content).

C. Production of aqueous polyurethane dispersion The blocked isonoanate group-containing brepolymer solution obtained in A above and the polyamine solution obtained in B above were mixed and stirred so as to be uniform.

Next, 55.6 parts of triethylamine was added, followed by 3 parts of water.
When 200 parts were added dropwise, a milky white aqueous dispersion was obtained. When this aqueous dispersion was heated to 80°C and held for 5 hours, it was observed that the amine value of the aqueous dispersion decreased and the amine in the polyamine disappeared. Thereafter, the solvent was removed under reduced pressure to obtain a stable aqueous polyurethane dispersion having a nonvolatile content of 40.5%, a pH of 7.5, and a viscosity of 650 cps.

The obtained polyurethane aqueous dispersion was applied to an untreated electrogalvanized steel plate to a thickness of 3 μm (dry film thickness), dried at room temperature for 24 hours, and then subjected to a salt spray test. No generation occurred even after 120 hours. No rust was observed and good adhesion was maintained.

Example 2 A. Prepolymer Preparation In an apparatus similar to Example 1, 500 parts of poly(oxytetramethylene) glycol (molecules jll O00), 45 parts of 1,4-butanediol, 26.8 parts of dimethylol were added. Propionic acid was added, and water was removed by heating at 100°C for 20 minutes under high vacuum. It was cooled to 75°C in a dry nitrogen atmosphere and 591 parts of methyl ethyl ketone was added. This solution was further cooled to 30°C and tolylene diisocyanate 315 with an isomer ratio of 2.4-72.6- was 80720.
Added a section. Gradually heat to 70°C using heat generation
It was held for 3 hours.

The obtained prepolymer had an NCO content of 3.18% and an acid value of 7.0. While maintaining the same temperature, add 104.4 parts of methyl ethyl ketoxime! I put it down.

B. Production of polyamine 400 parts of methyl ethyl ketone was added to the same apparatus as in Example 1, and then 475.2 parts of hydrogenated MDA was dissolved.
At 0°C, 360 parts of bisphenol A type epoxy resin having an epoxy equivalent of 300 was gradually added over 1 hour. After the addition is complete, if the temperature is maintained for 2 hours, 1149% of the amine
A polyamine solution of s (per solids content) was obtained.

C. Preparation of aqueous polyurethane dispersion The pronocdoisocyanate group-containing prepolymer solution obtained in A above and the polyamine solution obtained in B above were mixed and stirred so as to be uniform. Next, 20.2 parts of triethylamine was added, and then 2,600 parts of water was added dropwise to obtain a milky white aqueous dispersion. 70% of this aqueous dispersion
When the temperature was raised to °C and maintained for 5 hours, the amine value of the aqueous dispersion decreased and the amine in the polyamine was observed to disappear.

After that, when the solvent was removed under reduced pressure, the nonvolatile content was 41.1%, and the pH was
7.3, a stable aqueous polyurethane dispersion with a viscosity of 830 cps was obtained.

The obtained polyurethane aqueous dispersion was applied to an untreated electrogalvanized steel plate to a thickness of 3 μm (dry film thickness), dried at room temperature for 24 hours, and then subjected to a salt spray test. No generation occurred even after 120 hours. No rust was observed and good adhesion was maintained.

Example 3 A. Prepolymer Preparation In an apparatus similar to Example 1, a polyester polyol with a molecular weight of 2000 made from 1000 parts of 16-hexanediol/neopentyl glycol/adipic acid and 45 parts of 1,4-butanediol were added. and heated at 100'c under high vacuum.
The mixture was heated for 20 minutes to remove moisture. It was cooled to 75°C in a dry nitrogen atmosphere and 1030 parts of methyl ethyl ketone were added. This solution was further cooled to 30°C and 500 parts of 4,4-diphenylmethane diisocyanate was added. The mixture was gradually heated using heat generation and maintained at 70°C for 3 hours. The NGO content of the obtained prepolymer was 3.26% torn. While maintaining the same temperature, 174 parts of methyl ethyl keto beef shim was added dropwise.

B. Production of polyamine 400 parts of methyl ethyl ketone was added to the same apparatus as in Example 1, and then 150 parts of 2-methylpiperazine was dissolved, and then bisphenol A having an epoxy equivalent of 500 was added at 50°C.
500 parts of mold epoxy resin were gradually added over a period of 1 hour. After the addition was completed, the solution was maintained at the same temperature for 2 hours to obtain a polyamine solution having an amine equivalent weight of 325 (per solid content).

C. Production of aqueous polyurethane dispersion The blocked isocyanate group-containing prepolymer solution obtained in A above and the polyamine solution obtained in B above were mixed and stirred to achieve uniformity. Next, polyoxyethylene-polyoxybrobylene block polymer 8
A milky white aqueous dispersion was obtained by adding 3300 parts of water in which 0 part was dissolved and passing it through a colloid mill while stirring. When this aqueous dispersion was heated to 70°C and held for 5 hours, it was observed that the amine value of the aqueous dispersion decreased and the amine in the polyamine disappeared. Thereafter, the solvent was removed under reduced pressure to obtain a stable aqueous polyurethane dispersion having a nonvolatile content of 40.6%, a pH of 7.9, and a viscosity of 440 cps.

The obtained polyurethane aqueous dispersion was applied to an untreated electrogalvanized steel plate to a thickness of 3 μm (dry film thickness), dried at room temperature for 24 hours, and then subjected to a salt spray test. No generation occurred even after 120 hours. No rust was observed and good adhesion was maintained.

Comparative Example 1 A polyurethane aqueous dispersion was obtained under the same conditions as in Example 1 except that 75 parts of 2-methylbiperazine was used as the polyamine aqueous solution of B above. The final polyurethane aqueous dispersion had a solid content of 40.2%, a pH of 7.2, and a viscosity of 2.
It was 50 cps.

The obtained polyurethane aqueous dispersion was applied to an untreated electrogalvanized steel plate to a thickness of 3 μm (dry film thickness) in the same manner as in Example 1, and after drying at room temperature for 24 hours, a salt water spray test was conducted. However, 24 hours later, rust was observed.
After 0 hours, rust was observed on the entire surface of the coated plate.

(Effects of the Invention) The present invention provides an aqueous polyurethane dispersion that has excellent adhesion to the surface of an inorganic compound and can provide a good coating film having excellent mechanical properties.

Claims (1)

[Claims] 1. An aqueous polyurethane dispersion characterized in that an amino group-containing polymer obtained by reacting a polyepoxy compound and a polyamine compound and a blocked isocyanate group-containing prepolymer are dispersed in water and then reacted. Liquid manufacturing method. 2. The method for producing an aqueous polyurethane dispersion according to claim 1, wherein the blocked isocyanate group-containing prepolymer has isocyanate groups and carboxyl groups and forms a stable aqueous dispersion. 3. The method for producing an aqueous polyurethane dispersion according to claim 1 or 2, characterized in that an aqueous emulsifier solution is added to a homogeneous solution of a mixture of an amino group-containing polymer and a blocked isocyanate group-containing prepolymer to emulsify the mixture, followed by reaction. . 4. The method for producing an aqueous polyurethane dispersion according to claim 1, 2 or 3, wherein the blocked isocyanate group-containing prepolymer is obtained using polyoxyethylene glycol monomethyl ether. 5. Claim 1, characterized in that the blocked isocyanate group-containing prepolymer is blocked with an oxime.
, 2, 3 or 4. The method for producing an aqueous polyurethane dispersion according to . 6. The method for producing an aqueous polyurethane dispersion according to claim 1, wherein the polyepoxy compound is a bisphenol A type epoxy resin.