JP2009102555A - Aqueous resin composition and aqueous coating composition containing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous resin composition capable of forming a coating film excellent in water resistance and corrosion resistance and to provide an aqueous coating composition containing this. <P>SOLUTION: The aqueous resin composition is the one in which a polyurethane resin (III) is dispersed in an aqueous medium, which polyurethane resin is the one obtained by the reaction of an epoxy prepolymer (I) having an amino group on the terminal that is obtained by the reaction between a polyepoxy compound (a) and an amino compound (b) and a urethane prepolymer (II) having an isocyanate group on the terminal that is obtained by the reaction between a compound (c) having two or more hydroxyl groups in one molecule and a polyisocyanate compound (d) and in which both or either of the epoxy prepolymer (I) and the urethane prepolymer (II) has a polyoxyalkylene chain in the side chain. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an aqueous resin composition capable of forming a coating film excellent in water resistance and corrosion resistance, and an aqueous coating composition containing the same.

  In recent years, in the fields of paints, inks, adhesives, etc., from the viewpoint of resource saving, environmental hygiene, non-pollution, non-hazardous materials, etc., conversion from organic solvent type compositions to aqueous type compositions has been promoted. . For example, examples of the vehicle used in the aqueous coating composition include resins such as alkyd resins, acrylic resins, polyester resins, polyurethane resins, and epoxy resins. Of these, epoxy resins have been used for a wide range of applications because of their excellent adhesion to various materials. However, when making these epoxy resins water-based, emulsifiers are used, or hydrophilic groups in the resin skeleton are used. In all cases, these properties are sufficiently satisfactory for water-based paint applications, such as reduced corrosion resistance, water resistance, and adhesion to metal materials compared to solvent-based systems. The current situation is that nothing has been obtained.

  As a method for compensating for the deterioration of corrosion resistance and water resistance associated with the aqueousization of such an epoxy resin, for example, a method of introducing a phosphate group having good adhesion to a metal material into an epoxy resin skeleton has been proposed (for example, Patent Documents). 1, Patent Document 2, etc.). However, this method has a limitation that an alcohol solvent or the like cannot be used at the time of synthesis.

  Patent Document 3 proposes a method of using an aqueous epoxy ester resin obtained by modifying an epoxy ester obtained by reacting an unsaturated fatty acid with an epoxy resin with a monomer having a carboxyl group. Although this method shows an improvement in corrosion resistance, it is not sufficient in a field where high corrosion resistance is required.

  Patent Document 4 proposes to use a polyol resin composition obtained by adding a specific isocyanate compound having a polyether structure to an epoxy polyol resin. By using this composition, it is possible to provide a water-based paint that forms a coating film excellent in adhesion, water resistance, corrosion resistance, etc., but there is a problem that gelation tends to occur during the synthesis of the resin.

JP-A-5-14850 JP-A-4-298580 JP 2003-64302 A JP 2004-182867 A

  In view of the above, the present applicant uses a specific epoxy prepolymer and urethane prepolymer as a composite resin via a urea bond, so that the film has excellent film formability and adhesion, and has high corrosion resistance and water resistance. A water-based resin composition capable of forming a liquid was proposed (Japanese Patent Application No. 2006-131198). However, depending on other components added when this aqueous resin composition is used for metal surface coating, the salt stability of the aqueous dispersion may not be obtained.

  The objective of this invention is providing the water-based resin composition which can eliminate the said malfunction, and can form the coating film which has high corrosion resistance and water resistance, and the water-based coating composition containing this.

  The present invention relates to an epoxy prepolymer (I) having an amino group at the terminal obtained by a reaction between a polyepoxy compound (a) and an amine compound (b), and a compound containing two or more hydroxyl groups in one molecule (c ) And a polyisocyanate compound (d), and a polyurethane resin obtained by a reaction with a urethane prepolymer (II) having an isocyanate group at the terminal, the epoxy prepolymer (I) and the urethane prepolymer (II) ), Or an aqueous resin composition characterized in that the polyurethane resin (III) having a polyoxyalkylene chain in the side chain is dispersed in water in an aqueous medium, and It is related with the water-based coating composition containing.

  According to the aqueous resin composition of the present invention, a specific epoxy prepolymer and a urethane prepolymer are combined into a composite resin via a urea bond, and the epoxy prepolymer and the urethane prepolymer are in the side chain of either or any one of them. By providing an oxyalkylene chain, it is possible to form a coating film having excellent salt stability of the aqueous dispersion, excellent film formability and adhesion, and high corrosion resistance and water resistance.

  In the present invention, the epoxy prepolymer (I) has an amino group at the terminal and is obtained by a reaction between the polyepoxy compound (a) and the amine compound (b).

  The polyepoxy compound (a) is a compound having two or more epoxy groups in one molecule, such as bisphenol A, bisphenol F, bisphenol S, hydrogenated bisphenol A, neopentyl glycol, 1,6-hexanediol, etc. Diglycidyl ethers of polyhydric alcohols; glycidyl ether type epoxy resins such as bisphenol A and bisphenol F, hydrogenated bisphenol A type epoxy resins, glycidyl ester type epoxy resins, alicyclic epoxy resins, polyglycol type epoxy resins; A modified epoxy resin obtained by modifying an epoxy resin with at least one modifier selected from alkylphenols and fatty acids; obtained by reacting an alkylphenol or an alkylphenol novolac resin with epichlorohydrin Epoxy group-introduced alkylphenol or alkylphenol novolak type resins; dibasic acid modified epoxy resins, and the like modified epoxy resin dibasic acid and a carboxyl group-containing phenol.

  The amine compound (b) is a compound having a primary amino group, for example, an aliphatic amine such as propylamine, isopropylamine, butylamine, amylamine, hexylamine, octylamine, decylamine, undecylamine, dodecylamine; Aromatic amines such as aniline, o-toluidine, m-toluidine, and p-toluidine; cycloaliphatic amines such as cyclobutylamine, cyclopentylamine, and cyclohexylamine; and methylaminopropylamine and the like. Can do. Further, as the amine compound (b), an alkanolamine can be used when a highly reactive active hydrogen group is left in the resin (III). Examples of the alkanolamine include monoethanolamine and monoisopropanolamine. N-methylethanolamine, N-ethylethanolamine, N-benzylethanolamine, diethanolamine, diisopropanolamine and the like can be used in combination with these as required. Furthermore, aminosilane can be used as the amine compound (b) from the viewpoint of improving the water resistance of the formed coating film. The aminosilane contains an amino group and an alkoxysilyl group in one molecule, and specific examples thereof include, for example, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldisilane. Examples include ethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) aminopropyltrimethoxysilane, and N-β- (aminoethyl) aminopropyltriethoxysilane.

  In the present invention, when the polyoxyalkylene chain is added to the side chain of the epoxy prepolymer (I), a polyoxyalkyleneamine can be used as the amine compound (b). The polyoxyalkyleneamine is not particularly limited as long as it is a compound having a primary amino group and further having a polyoxyalkylene chain, and various compounds can be used. Examples of the polyoxyalkylene chain include a polyoxyethylene chain, a polyoxypropylene chain, a block chain of polyoxyethylene and polyoxypropylene, and the like. The polyoxyalkylene chain preferably has a molecular weight in the range of 100 to 10,000, particularly 200 to 8,000.

  Representative examples of the polyoxyalkyleneamine include, for example, the following general formula (1)

(Wherein R ₁ represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms, R ₂ represents a hydrogen atom or a methyl group, m is an integer of 2 to 220, preferably 5 to 180, and n is 2) An integer of ˜3, preferably 2, wherein m oxyalkylene units (CnH ₂ nO) may be the same or different from each other).

  The production of the epoxy prepolymer (I) is not particularly limited, and a conventionally known method can be adopted, and it is usually performed by heating at 50 to 250 ° C. for 1 to 24 hours. The proportions of the components (a) and (b) can be variously changed, but the equivalent ratio of the epoxy group in the component (a) and the amino group in the component (b) is generally 1: 0.5 to 1 : 2, preferably 1: 0.5 to 1: 0.9.

  In the present invention, the urethane prepolymer (II) is obtained by reacting a compound (c) having an isocyanate group at the terminal and containing two or more hydroxyl groups in one molecule with the polyisocyanate compound (d). .

  The compound (c) has two or more hydroxyl groups in one molecule, and examples thereof include low molecular weight glycols, high molecular weight glycols, polyester polyols, polycarbonate polyols and the like. For example, a low molecular weight glycol can be used in combination with a polyester polyol or a high molecular weight glycol.

  Examples of the low molecular weight glycols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, octanediol, and tricyclodecanedi. There are methylol, cyclohexanedimethanol, hydrogenated bisphenol A and the like, and these may be used alone or in combination of two or more.

  Examples of the high molecular weight glycols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and polycarbonate glycol. Polyester polyols include those obtained by reacting a glycol component with a dicarboxylic acid component. It can manufacture easily by this, and it can manufacture not only by esterification but also by transesterification. Moreover, the polyester diol obtained by ring-opening reaction of cyclic ester compounds, such as (epsilon) -caprolactone, and these cocondensation polyesters can also be included.

  The said compound (c) can contain a bisphenol skeleton containing diol compound as at least one part of the component from the point of the corrosion-resistant improvement of a formation coating film.

  Examples of the bisphenol skeleton-containing diol compound include ethylene oxide and / or propylene oxide adducts of bisphenols. Examples of bisphenols include bisphenol A, bisphenol F, and bisphenol S.

  When the bisphenol skeleton-containing diol compound is used, the content in the compound (c) is 10 to 98% by weight, preferably 50 to 95% by weight.

  In the present invention, when the side chain of the urethane prepolymer (II) has a polyoxyalkylene chain, the compound (c) contains a polyol having a polyoxyalkylene chain in the side chain as at least a part of the component. Is preferred.

  Polyol having a polyoxyalkylene in the side chain is a compound having two or more hydroxyl groups in one molecule and further having a polyoxyalkylene chain, which becomes a side chain when incorporated into a urethane prepolymer. Various compounds can be used without particular limitation as long as a polyoxyalkylene chain can be introduced into the portion. Examples of the polyoxyalkylene chain include a polyoxyethylene chain, a polyoxypropylene chain, a block chain of polyoxyethylene and polyoxypropylene, and the like. The polyoxyalkylene chain preferably has a molecular weight in the range of 100 to 10,000, particularly 200 to 8,000.

  Specific examples of the polyol having a polyoxyalkylene in the side chain include, for example, a reaction product of an acrylate having a polyoxyalkylene chain and a dialkanolamine, a reaction product of glycerin carbonate and a polyoxyalkyleneamine, and the like. Further, it may be a reaction product of glycidol and polyoxyalkyleneamine.

  As an acrylate having a polyoxyalkylene chain, for example, the following formula (2)

(In the formula, R ₃ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, m is an integer of 2 to 220, preferably 5 to 180, and n is an integer of 2 to 3, preferably 2. , Where m oxyalkylene units (CnH ₂ nO) may be the same or different from each other). Specific examples thereof include polyethylene glycol acrylate, polypropylene glycol acrylate, methoxy polyethylene glycol acrylate, and ethoxy polyethylene glycol acrylate.

  Examples of dialkanolamines include diethanolamine and dipropanolamine.

  The acrylate having a polyoxyalkylene chain and the dialkanolamine have a molar ratio of acrylate to amino group of 1: 0.8 to 1: 1.2, preferably 1: 0.95 to 1: 1.05. It is desirable to make it react so that. This reaction is usually performed at a temperature of 25 to 250 ° C, preferably 50 to 160 ° C.

  As said polyoxyalkylene amine, the thing similar to the polyoxyalkylene amine demonstrated in the above-mentioned amine compound (b) can be selected suitably, and can be used. Glycerin carbonate and polyoxyalkyleneamine have a molar ratio of cyclic carbonate group in glycerin carbonate to amino group in polyoxyalkyleneamine of 1: 0.8 to 1: 1.2, preferably 1: 0.95. It is desirable to make it react so that it may become the range of -1: 1.05. This reaction is usually performed at a temperature of 25 to 250 ° C, preferably 50 to 160 ° C.

  Moreover, when making urethane prepolymer (II) anionic in this invention, it is suitable for the said compound (c) to contain a carboxyl group-containing diol as at least one part of the component.

  Examples of carboxyl group-containing diols include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid and polyester polyols or polycondensates thereof. Examples include ether polyols. These can be used in combination with hydroxycarboxylic acids such as 12-hydroxystearic acid, 2,2-dimethyl-3-hydroxypropionic acid and salicylic acid.

  The polyisocyanate compound (d) contains two or more isocyanate groups in one molecule. Specific examples thereof include aliphatic groups such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, and lysine diisocyanate. Polyisocyanates; burette type adducts, isocyanurate cycloadducts of these polyisocyanates; isophorone diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4- (or -2,6-) Diisocyanate, 1,3- (or 1,4-) di (isocyanatomethyl) cyclohexane, 1,4-cyclohexane diisocyanate, 1,3-cyclopentane diisocyanate, 1,2-cyclohex Alicyclic diisocyanates such as diisocyanates; bullet type adducts and isocyanurate cycloadducts of these diisocyanates; xylylene diisocyanate, metaxylylene diisocyanate, tetramethyl xylylene diisocyanate, tolylene diisocyanate, 4, 4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-naphthalene diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether isocyanate, (m- or p-) phenylene diisocyanate, 4,4′-biphenylene diisocyanate, 3,3′-dimethyl-4,4′-biphenylene diisocyanate, bis (4-isocyanatophenyl) sulfone, isopropylidenebis (4-phenyl) Aromatic diisocyanate compounds such as phenyl isocyanate); bullet type adducts of these diisocyanate compounds, isocyanurate cycloadducts; triphenylmethane-4,4 ′, 4 ″ -triisocyanate, 1,3, Three or more isocyanate groups in one molecule such as 5-triisocyanatobenzene, 2,4,6-triisocyanatotoluene, 4,4′-dimethyldiphenylmethane-2,2 ′, 5,5′-tetraisocyanate Polyisocyanates having the following: burette type adducts, isocyanurate cycloadducts of these polyisocyanates; ethylene glycol, propylene glycol, 1,4-butylene glycol, dimethylolpropionic acid, polyalkylene glycol, trimethylolpropane, hexane Trial Urethane adducts obtained by reacting a polyisocyanate compound in an excess ratio of isocyanate groups to hydroxyl groups of polyols; burette type adducts, isocyanurate ring adducts, etc. of these urethanized adducts. it can.

  In the present invention, the urethane prepolymer (II) also has a polyoxyalkylene chain in the side chain of the urethane prepolymer (II) by including the polyisocyanate having a polyoxyalkylene in the side chain as at least a part of the component (d). It is possible. The polyisocyanate having polyoxyalkylene in the side chain is not particularly limited as long as it is a compound having two or more isocyanate groups in one molecule and further having a polyoxyalkylene chain. These compounds can be used.

  In the present invention, when the urethane prepolymer (II) is cationic, a compound (e) containing two or more active hydrogen groups in one molecule and containing a tertiary amino group is used as a production raw material. be able to.

  The compound (e) preferably contains two or more active hydrogen groups in one molecule and a tertiary amino group. For example, a diol compound, a triol compound, or a diamine compound having a tertiary amino group. And triamine compounds. These may be used alone or in combination of two or more.

  Examples of the diol compound having a tertiary amino group include N-methyldiethanolamine, N-ethyldiethanolamine, and N-isobutyldiethanolamine. Examples of the triol compound having a tertiary amino group include triethanolamine. . Examples of the diamine compound having a tertiary amino group include methyliminobispropylamine and butyliminobispropylamine. Examples of the triamine compound having a tertiary amino group include tri (2-aminoethyl) amine. Etc.

  Production of the urethane prepolymer (II) is not particularly limited, and a conventionally known method can be employed. For example, the above-described components (c) and (d) (component (e) as required) are reacted at once. You may make it react, and you may make it react in multistage. The proportions of the above components (c) and (d) (component (e) as required) can be varied, but the equivalent ratio of isocyanate groups to active hydrogen groups in all components is generally 1: 0. It is desirable that the ratio is 9 to 1: 0.5, preferably 1: 0.9 to 1: 0.7. The reaction is usually carried out at a temperature of 40 to 180 ° C, preferably 60 to 130 ° C. In order to promote this reaction, amine catalysts such as triethylamine, N-ethylmorpholine, and triethylenediamine used in ordinary urethanization reactions and tin catalysts such as dibutyltin dilaurate and dioctyltin dilaurate are used as necessary. It may be used.

  In the aqueous resin composition of the present invention, the polyurethane resin (III) obtained by the reaction between the epoxy prepolymer (I) and the urethane prepolymer (II) is dispersed in water in an aqueous medium.

  The reaction between the epoxy prepolymer (I) and the urethane prepolymer (II) is not particularly limited, and a conventionally known method can be adopted. Usually, the reaction is performed by heating at 20 to 80 ° C. for 0.1 to 10 hours. Is called. The use ratio of both can be variously changed, but the equivalent ratio of the amino group in the epoxy prepolymer (I) to the isocyanate group in the urethane prepolymer (II) is 0.01: 1 to 0.9: 1, It is desirable to select it so that it is preferably 0.2: 1 to 0.8: 1. Here, the amino group subjected to the reaction with the isocyanate group is naturally a primary and secondary amino group having active hydrogen.

  The polyurethane resin (III) obtained as described above is dispersed in an aqueous medium. Examples of the aqueous medium include water or a water-organic solvent mixed solution obtained by dissolving water or an organic solvent such as a water-soluble organic solvent. Water dispersion can be carried out by a conventionally known method without particular limitation. For example, when a carboxyl group is introduced into the polyurethane resin (III), a base is added as necessary to neutralize the water, It can be mixed and dispersed by stirring while gradually adding. The base is not particularly limited as long as it can neutralize the carboxyl group, and examples thereof include sodium hydroxide, potassium hydroxide, trimethylamine, dimethylaminoethanol, 2-methyl-2-aminopropanol, triethylamine, and ammonium. It is done. These bases may be neutralized with a carboxyl group in addition to the polyurethane resin (III), or may be neutralized simultaneously with the dispersion by adding it to water as a dispersion medium.

  When a tertiary amino group is introduced into the polyurethane resin (III), a part or all of the tertiary amino group is neutralized with an acid or quaternized with a quaternizing agent. Water dispersion can be performed. Examples of the acid used for neutralization include formic acid, acetic acid, lactic acid, and phosphoric acid. These acids may be neutralized with tertiary amino groups in addition to polyurethane resin (III), or may be neutralized simultaneously with dispersion by adding to water as a dispersion medium.

  Examples of the quaternizing agent include epoxy compounds such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide and epichlorohydrin, sulfates such as dimethyl sulfate, diethyl sulfate and methyl paratoluenesulfonate, methyl chloride, and ethyl. Examples thereof include alkyl halides such as chloride, benzyl chloride, methyl bromide, and ethyl bromide.

  In the present invention, as described above, some or all of the carboxyl groups in the polyurethane resin (III) are neutralized with a base, or some or all of the tertiary amino groups in the polyurethane resin (III) are acidified. Or after quaternization with a quaternizing agent, it may be emulsified and dispersed in water, and at the same time as the dispersion, the chain extension reaction with an aqueous medium may be partially advanced. It can be extended to increase the molecular weight. Examples of the chain extender include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4′-dicyclohexylmethanediamine, and 3,3′-. Diamines such as dimethyl-4,4′-dicyclohexylmethanediamine, 1,4-cyclohexanediamine, polyoxyethylenediamine, polyoxypropylenediamine, amine-terminated polyoxyethylene-polyoxypropylene copolymer; diethylenetriamine, dipropylenetriamine, tri Polyamines such as ethylenetetramine and tetraethylenepentamine; hydroxyethylhydrazine, hydroxyethyldiethylenetriamine, 2-[(2-aminoethyl) amino] ethanol, 3-aminopropanedio Compounds having an amino group and a hydroxyl group, such as Le; hydrazines, acid hydrazides, and the like. These may be used singly or in combination.

  The polyurethane resin (III) may be any one of the epoxy prepolymer (I) and the urethane prepolymer (II) as long as it has a polyoxyalkylene chain in the side chain. It is preferable from the viewpoint of stability. The polyurethane resin (III) has an acid value of 0 to 100 mgKOH / g, preferably 0 to 90 mgKOH / g, or an amine value of 0 to 100 mgKOH / g, preferably 0 to 90 mgKOH / g. Especially in the case of anionic, the acid value is 5 to 100 mgKOH / g, preferably 8 to 80 mgKOH / g, and in the case of cationic, the amine value is 5 to 100 mgKOH / g, preferably 8 to 90 mgKOH / g. It is preferable from the viewpoint of the corrosion resistance of the formed coating film. Further, the polyurethane resin (III) preferably has a hydroxyl value of 20 to 200 mgKOH / g, preferably 30 to 150 mgKOH / g, from the viewpoint of adhesion of the formed coating film, corrosion resistance, and the like.

  The aqueous resin composition of the present invention contains the polyurethane resin (III), and may further contain other water-soluble or water-dispersible resins and curing agents as necessary. Examples of other water-soluble or water-dispersible resins include acrylic resins, alkyd resins, silicon resins, fluorine resins, epoxy resins, urethane resins, and polyester resins. The curing agent can be used without particular limitation as long as it reacts with the crosslinkable functional group in the polyurethane resin (III). For example, (block) polyisocyanate, melamine resin, polyepoxy compound, phenol resin, urea resin, Guanamin resin and the like can be suitably used.

  The aqueous resin composition may further comprise a wetting agent, an antifoaming agent, a plasticizer, a film-forming aid, an organic solvent, a thickener, an antiseptic, an antifungal agent, a pH adjuster, a curing catalyst, a metal, if necessary. Additives such as a dryer, an ultraviolet absorber, an ultraviolet stabilizer, and a surface conditioner can be appropriately selected and contained in combination.

  The present invention also provides an aqueous coating composition comprising the above aqueous resin composition. The aqueous paint composition can be used as a clear paint or as an enamel paint. When used as an enamel paint, a color pigment, a luster pigment, an extender pigment, a rust preventive pigment and the like known in the paint field can be blended as a pigment component.

  The aqueous coating composition may further contain additives such as a pigment dispersant, a surfactant, and a flash last inhibitor, if necessary, alone or in combination of two or more.

The aqueous coating composition of the present invention can be applied to a surface to be coated by a method such as air spray coating, airless spray coating, electrostatic coating, brush coating, roller coating, lysing gun, or universal gun.
The coated surface to which the water-based coating composition can be applied is not particularly limited, and examples thereof include metals such as iron and aluminum; inorganic base materials such as concrete, mortar, slate plate, wood and stone; plastics and the like Examples thereof include a substrate surface such as an organic substrate and a surface-treated surface thereof, and a metal surface and a surface-treated surface thereof are particularly suitable. The water-based coating composition of the present invention can be applied to these coated surfaces as an undercoat, and a known topcoat can be further applied as necessary.

  Hereinafter, the present invention will be described in more detail with reference to examples. “Part” and “%” indicate “part by weight” and “% by weight” unless otherwise specified.

Example 1
Preparation of epoxy prepolymer (I-1) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, in which a bisphenol A type epoxy resin (126 g) having an epoxy equivalent of 450 g / eq, Dissolved in propylene glycol monopropyl ether (54.91 g), and added to this, “Jeffamine M-2070” (manufactured by Huntsman, R ₁ is a methoxy group, a block chain of polyoxyethylene and polyoxypropylene, a number average molecular weight of about 2000) (140 g) was added and reacted at 90 ° C. for 3 hours, then 2-aminoethanol (8.55 g) was added and held at 90 ° C. for 3 hours, and the epoxy group and amino group content (Note 1) was The reaction was continued until it reached about 0.762 to 0.767 mmol / g. Thereafter, methyl ethyl ketone (219.6 g) was added to obtain an epoxy prepolymer (I-1) solution. The resulting epoxy prepolymer (I-1) solution had a solid concentration of 50%.

(Note 1) Epoxy group and amino group content: Followed by the following measurement method.
The sample (g) is weighed in an Erlenmeyer flask, and 40 ml of methyl ethyl ketone is added to dissolve it. If difficult to dissolve, heat to 50 ° C to dissolve. Next, 10 ml of CTAB (cetyltrimethylammonium bromide) solution is added with a total pipette to make it uniform. Subsequently, 0.2 ml of screen indicator is accurately added, titrated with an N / 10 perchloric acid-acetic acid solution, and the end point is reached when pink lasts for about 30 seconds with the last drop. Calculated from the following calculated values. The CTAB solution was dissolved by adding 200 ml of acetic acid to 20 g of CTAB, and further adjusted to a uniform solution by adding 200 ml of methyl ethyl ketone. The screen indicator was 1.5 g of thymol blue in a solution of 0.3 g of alphazulin in 100 ml of glacial acetic acid. Was prepared by mixing a solution prepared by dissolving the solution in 500 ml of methanol.
Formula: E = (AB) × 0.1 × F / S × 0.01 × W
Where E: epoxy group and amino group content (mmol / g)
A: Amount of N / 10 perchloric acid-acetic acid solution used in this test (ml)
B: Amount of N / 10 perchloric acid-acetic acid solution used in the blank test (ml)
Factor of F: N / 10 perchloric acid-acetic acid solution
S: Sample heating residue (%)
W: Sample amount

Preparation of urethane prepolymer (II-1) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, among which "Bisol 3PN" (Note 2) (44.9), "Bisol 6PN "(Note 3) (64.7 g), methyldiethanolamine (20.9 g) was dissolved in N-methylpyrrolidone (45.1 g), and hexamethylene diisocyanate (50.5 g) was added dropwise over 30 minutes. The reaction was carried out at ° C for 1.5 hours. Thereafter, the temperature was raised to 80 ° C., and the reaction was carried out for 2 hours. Isophorone diisocyanate (44.4 g) was added, and the mixture was further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 34 to 41. Thereafter, methyl ethyl ketone (105.1 g) was added to obtain a urethane prepolymer (II-1) solution. The solid content concentration of the obtained urethane prepolymer (II-1) solution was 60.0%, and the amine value of the prepolymer was 43.6 mgKOH / g.

(Note 2) Bisol 3PN: manufactured by Toho Chemical Co., Ltd., propylene oxide modified bisphenol A (propylene oxide modified amount = 3 mol)
(Note 3) Bisol 6PN: manufactured by Toho Chemical Co., Ltd., propylene oxide modified bisphenol A (propylene oxide modified amount = 6 mol)
(Note 4) NCO value: The amount of isocyanate group contained in 1 g of urethane prepolymer was converted to the weight of isocyanate (mg), and was tracked by the following measuring method. In addition, when a tertiary amino group containing compound is included in a manufacturing raw material, the quantity of the tertiary amino group is also converted and contained in the weight of isocyanate.
Sample (g) is correctly weighed into an Erlenmeyer flask, 10 ml of dioxane is added, the dissolved sample is heated to 50 ° C., 10 ml of N / 5 dibutylamine-dioxane solution that has been correctly weighed is added, and the mixture is stirred for 2 minutes. React butylamine. Next, add 2 to 3 drops of bromophenol blue-ethyl alcohol solution and titrate with N / 10 hydrochloric acid solution, and the end point is when the color changes from blue to yellowish green.
Formula N = {0.1 × 42 × (AB) × f} /0.01×S×W} + C
Here, N: NCO value (mg of NCO contained in 1 g of sample)
A: Used to neutralize blank N / 5 dibutylamine-dioxane solution
Amount of N / 10 hydrochloric acid solution (ml)
B: Amount of N / 10 hydrochloric acid solution used for titration of sample (ml)
f: Factor of N / 10 hydrochloric acid solution
S: Sample heating residue (%)
W: Amount of sample (g)
42: Molecular weight of NCO
C: The amount (mol) of the tertiary amino group contained in the sample is the weight of the isocyanate.
Calculated with the following formula using the converted value (mg)
Formula C = {D / M × 42 × 1000} / E
Where D: blended during urethane prepolymer synthesis
Weight of tertiary amino group-containing monomer
M: Blended during urethane prepolymer synthesis
Molecular weight of tertiary amino group-containing monomer
E: Weight of all blended monomers

Preparation of aqueous polyurethane resin dispersion (III-1) Using a device similar to the above, a 60.0% urethane prepolymer (II-1) solution (375.5 g) was kept at 50 ° C. with stirring, A 50% epoxy prepolymer (I-1) solution (392.2 g) was added thereto and stirred for 1 hour. Next, the mixture was cooled to 40 ° C., neutralized with 89% aqueous phosphoric acid solution (8.3 g), deionized water (983.3 g) was added and dispersed, and then the temperature was raised to 70 ° C. and held for 1 hour. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-1) of polyurethane resin. The solid content concentration of this aqueous dispersion was 30.0%, the amine value of the polyurethane resin was 30.0 mgKOH / g, and the hydroxyl value was 60.4 mgKOH / g.

Example 2
Preparation of urethane prepolymer (II-2) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, among which "Bisol 3PN" (Note 2) (65.2g), "Bisol 6PN "(Note 3) (94.0 g), methyldiethanolamine (8.7 g) was dissolved in N-methylpyrrolidone (52.6 g), and hexamethylene diisocyanate (50.5 g) was added dropwise over 30 minutes. The reaction was carried out at ° C for 1.5 hours. Thereafter, the temperature was raised to 80 ° C. and the reaction was carried out for 2 hours, isophorone diisocyanate (44.4 g) was added, and the mixture was further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 29 to 36. Thereafter, methyl ethyl ketone (122.6 g) was added to obtain a urethane prepolymer (II-2) solution. The solid content concentration of the obtained urethane prepolymer (II-2) solution was 60.0%, and the amine value of the prepolymer was 15.6 mgKOH / g.

Preparation of aqueous polyurethane resin dispersion (III-2) Using a device similar to the above, a 60.0% urethane prepolymer (II-2) solution (438 g) was kept at 50 ° C. in a stirred state. A 50% epoxy prepolymer (I-1) solution (392.2 g) was added and stirred for 1 hour. Next, the mixture was cooled to 40 ° C., dimethyl sulfate (15.8 g) was added and reacted for 1 hour, deionized water (1070.8 g) was added and dispersed, and then the temperature was raised to 70 ° C. for 1 hour. Retained. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-2) of polyurethane resin. This aqueous dispersion had a solid content concentration of 30.0% and a hydroxyl value of 55.5 mgKOH / g.

Example 3
Preparation of urethane prepolymer (II-3) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, and terminal methoxypolyethylene glycol monoacrylate (number average molecular weight 1054) (105.4 g), diethanolamine (10.5 g) was added and stirred at 80 ° C. for 15 hours. After confirming that the amine value was 1 or less, a polyethylene glycol-modified diol was obtained.

  Using the same apparatus as above, among them, “Bisol 3PN” (Note 2) (40.2 g), “Bisol 6PN” (Note 3) (57.9 g), Methyldiethanolamine (17.7 g), Polyethylene glycol Modified diol (58.0 g) was dissolved in N-methylpyrrolidone (53.7 g), hexamethylene diisocyanate (50.5 g) was added dropwise over 30 minutes, and the reaction was carried out at 60 ° C. for 1.5 hours. Thereafter, the temperature was raised to 80 ° C., and the reaction was carried out for 2 hours. Isophorone diisocyanate (44.4 g) was added, and the mixture was further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 34 to 41. Thereafter, methyl ethyl ketone (125.3 g) was added to obtain a urethane prepolymer (II-3) solution. The solid content concentration of the obtained urethane prepolymer (II-3) solution was 60.0%, and the amine value of the prepolymer was 41.5 mgKOH / g.

Preparation of aqueous polyurethane resin dispersion (III-3) Using a device similar to the above, a 60.0% urethane prepolymer (II-3) solution (447.6 g) was kept at 50 ° C. with stirring, A 50% epoxy prepolymer (I-1) solution (392.2 g) was added thereto and stirred for 1 hour. Next, the mixture was cooled to 40 ° C., neutralized with 89% aqueous phosphoric acid (9.1 g), dispersed by adding deionized water (1084.2 g), then heated to 70 ° C. and held for 1 hour. Then, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-3) of polyurethane resin. The solid content concentration of this aqueous dispersion was 30.0%, the amine value of the polyurethane resin was 30.0 mgKOH / g, and the hydroxyl value was 54.8 mgKOH / g.

Example 4
Preparation of urethane prepolymer (II-4) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was purged with nitrogen to give Jeffamine M-2070 (200 g), glycerin carbonate (11.8 g). ) And stirred at 100 ° C. for 1 hour. After confirming that the amine value was 1 or less, polyetheramine-modified glycerin carbonate was obtained.
Using the same apparatus as above, among them, “Bisol 3PN” (Note 2) (36.2 g), “Bisol 6PN” (Note 3) (52.2 g), Methyldiethanolamine (23.1 g), the above polyether Amine-modified glycerin carbonate (53.0 g) was dissolved in N-methylpyrrolidone (51.8 g), hexamethylene diisocyanate (50.5 g) was added dropwise over 30 minutes, and the reaction was carried out at 60 ° C. for 1.5 hours. . Thereafter, the temperature was raised to 80 ° C. and the reaction was carried out for 2 hours, isophorone diisocyanate (44.4 g) was added, and the mixture was further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 36 to 43. Thereafter, methyl ethyl ketone (121.0 g) was added to obtain a urethane prepolymer (II-4) solution. The solid content concentration of the obtained urethane prepolymer (II-4) solution was 60.0%, and the amine value of the prepolymer was 41.9 mgKOH / g.

Preparation of aqueous polyurethane resin dispersion (III-4) Using a device similar to the above, a 60.0% urethane prepolymer (II-4) solution (432.0 g) was kept at 50 ° C. in a stirred state. A 50% epoxy prepolymer (I-1) solution (392.2 g) was added thereto and stirred for 1 hour. Next, the mixture was cooled to 40 ° C., neutralized with 89% phosphoric acid aqueous solution (8.9 g), dispersed by adding deionized water (1062.4 g), then heated to 70 ° C. and held for 1 hour. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-4) of polyurethane resin. The solid content concentration of this aqueous dispersion was 30.0%, the amine value of the polyurethane resin was 30.0 mgKOH / g, and the hydroxyl value was 55.9 mgKOH / g.

Example 5
Preparation of urethane prepolymer (II-5) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, among which "Bisol 3PN" (Note 2) (49.9), "Bisol 6PN "(Note 3) (71.9 g) and dimethylolpropionic acid (20.1 g) were dissolved in N-methylpyrrolidone (47.3 g), and hexamethylene diisocyanate (50.5 g) was added dropwise over 30 minutes. The reaction was carried out at 60 ° C. for 1.5 hours. Thereafter, the temperature was raised to 80 ° C. and the reaction was carried out for 2 hours. Isophorone diisocyanate (44.4 g) was added, and further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 34 to 38. Thereafter, methyl ethyl ketone (110.5 g) was added to obtain a urethane prepolymer (II-5) solution. The solid content concentration of the obtained urethane prepolymer (II-5) solution was 60.0%, and the acid value of the prepolymer was 35.5 mgKOH / g.

Preparation of aqueous polyurethane resin dispersion (III-5) Using a device similar to the above, a 60.0% urethane prepolymer (II-5) solution (394.5 g) was kept at 50 ° C. with stirring, A 50% epoxy prepolymer (I-1) solution (392.2 g) was added thereto and stirred for 1 hour. The mixture was then cooled to 40 ° C., neutralized with triethylamine (12.1 g), deionized water (1009.9 g) was added and dispersed, and then the temperature was raised to 70 ° C. and held for 1 hour. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-5) of polyurethane resin. The solid content concentration of this aqueous dispersion was 30.0%, the acid value of the polyurethane resin was 19.4 mgKOH / g, and the hydroxyl value was 58.8 mgKOH / g.

Example 6
Preparation of urethane prepolymer (II-6) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, among which “Bisol 3PN” (Note 2) (37.9 g), “Bisol 6PN "(Note 3) (54.6 g), dimethylolpropionic acid (21.4 g), and the polyethylene glycol-modified diol (58.0 g) prepared in Example 3 were dissolved in N-methylpyrrolidone (53.4 g). Then, hexamethylene diisocyanate (50.5 g) was added dropwise over 30 minutes and reacted at 60 ° C. for 1.5 hours. Thereafter, the temperature was raised to 80 ° C. and the reaction was carried out for 2 hours, isophorone diisocyanate (44.4 g) was added, and the mixture was further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 22 to 26. Thereafter, methyl ethyl ketone (125.3 g) was added to obtain a urethane prepolymer (II-6) solution. The obtained urethane prepolymer (II-6) solution had a solid content concentration of 60.0%, an amine value of the prepolymer of 10.5 mgKOH / g, and an acid value of 33.6 mgKOH / g.

Preparation of aqueous polyurethane resin dispersion (III-6) Using a device similar to the above, a 60.0% urethane prepolymer (II-6) solution (444.6 g) was kept at 50 ° C. with stirring, A 50% epoxy prepolymer (I-1) solution (392.2 g) was added thereto and stirred for 1 hour. Subsequently, it cooled to 40 degreeC, neutralized with triethylamine (12.9g), deionized water (1080g) was added and disperse | distributed, and it heated up at 70 degreeC after that, and hold | maintained for 1 hour. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-6) of a polyurethane resin. The solid content concentration of this aqueous dispersion was 30.0%, the amine value of the polyurethane resin was 12.1 mgKOH / g, the acid value was 19.4 mgKOH / g, and the hydroxyl value was 55.0 mgKOH / g.

Example 7
Preparation of epoxy prepolymer (I-2) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, and an epoxy equivalent of 450 g / eq of bisphenol A type epoxy resin (126 g) was It melt | dissolved in propylene glycol monopropyl ether (109.2g), "Jephamine M-2070" (420g) was added to this, and it was made to react at 90 degreeC for 3 hours. After confirming that the epoxy group and amino group content (Note 1) was about 0.380 to 0.390 mmol / g, methyl ethyl ketone (436.8 g) was added, and the epoxy prepolymer (I-2) solution was added. Obtained. The solid content concentration of the obtained epoxy prepolymer (I-2) solution was 50%.

Preparation of urethane prepolymer (II-7) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, among which “Bisol 3PN” (Note 2) (79.8 g), “Bisol 6PN "(Note 3) (115 g) and dibutyltin dilaurate (0.02 g) were dissolved in N-methylpyrrolidone (57.9 g), hexamethylene diisocyanate (50.5 g) was added dropwise over 30 minutes, For 1.5 hours. Thereafter, the temperature was raised to 80 ° C. and the reaction was carried out for 2 hours, isophorone diisocyanate (44.4 g) was added, and the mixture was further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 27 to 31. Thereafter, methyl ethyl ketone (135.2 g) was added to obtain a urethane prepolymer (II-7) solution. Solid content concentration of the obtained urethane prepolymer (II-7) solution was 60.0%.

Preparation of aqueous polyurethane resin dispersion (III-7) Using a device similar to the above, a 60.0% urethane prepolymer (II-7) solution (482.8 g) was kept at 50 ° C. with stirring, A 50% epoxy prepolymer (I-2) solution (780 g) was added thereto and stirred for 1 hour. Subsequently, it cooled to 40 degreeC, deionized water (1585.9g) was added and disperse | distributed, and it heated up at 70 degreeC after that, and hold | maintained for 1 hour. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-7) of polyurethane resin. The solid content concentration of this aqueous dispersion was 30.0%, and the hydroxyl value of the polyurethane resin was 29.2 mgKOH / g.

Example 8
Preparation of epoxy prepolymer (I-3) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, in which a bisphenol A type epoxy resin (126 g) having an epoxy equivalent of 450 g / eq, Dissolved in propylene glycol monopropyl ether (27.8 g), 2-aminoethanol (12.8 g) was added thereto, and the mixture was held at 85 ° C. for 3 hours. The epoxy group and amino group content (Note 1) was 1. The reaction was continued until it reached about 5 to 1.55 mmol / g. Thereafter, methyl ethyl ketone (111.1 g) was added to obtain an epoxy prepolymer (I-3) solution. The resulting epoxy prepolymer (I-3) solution had a solid concentration of 50%.

Preparation of urethane prepolymer (II-8) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was purged with nitrogen, and "bisol 3PN" (Note 2) (44.9 g) was substituted therein. ), “Bisol 6PN” (Note 3) (64.6 g), methyldiethanolamine (17.9 g), and the polyetheramine-modified glycerin carbonate (53.0 g) prepared in Example 4 above were added to N-methylpyrrolidone (55. 0 g), hexamethylene diisocyanate (50.5 g) was added dropwise over 30 minutes, and the reaction was carried out at 60 ° C. for 1.5 hours. Thereafter, the temperature was raised to 80 ° C. and the reaction was carried out for 2 hours, isophorone diisocyanate (44.4 g) was added, and the mixture was further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 33-40. Thereafter, methyl ethyl ketone (128.4 g) was added to obtain a urethane prepolymer (II-8) solution. The solid content concentration of the obtained urethane prepolymer (II-8) solution was 60.0%, and the amine value of the prepolymer was 30.6 mgKOH / g.

Preparation of aqueous polyurethane resin dispersion (III-8) Using a device similar to the above, a 60.0% urethane prepolymer (II-8) solution (458.6 g) was kept at 50 ° C. with stirring, A 50% epoxy prepolymer (I-3) solution (198.3 g) was added thereto and stirred for 1 hour. Next, the mixture was cooled to 40 ° C., neutralized with 89% phosphoric acid aqueous solution (7.4 g), deionized water (873.5 g) was added and dispersed, and then the temperature was raised to 70 ° C. and held for 1 hour. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-8) of polyurethane resin. The solid content concentration of this aqueous dispersion was 30.0%, the amine value of the polyurethane resin was 30.0 mgKOH / g, and the hydroxyl value was 75.5 mgKOH / g.

Comparative Example 1
A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, among which “Bisol 3PN” (Note 2) (269.8 g), “Bisol 6PN” (Note 3) (388.8 g) ) And methyldiethanolamine (77.2 g) were charged and stirred uniformly, and then hexamethylene diisocyanate (252.0 g) was added dropwise over 30 minutes, followed by reaction at 60 ° C. for 1.5 hours. Thereafter, the temperature was raised to 80 ° C. and the reaction was carried out for 2 hours. After adding methyl ethyl ketone (518.5 g) and dissolving, isophorone diisocyanate (222.0 g) was added and the NCO value (Note 4) was further increased at 80 ° C. for 3 hours. It was made to react until it became about 32-40, and the urethane prepolymer solution was obtained. Next, the mixture was cooled to 40 ° C., neutralized with 89% phosphoric acid (23.8 g), dispersed with deionized water (2246.8 g), heated to 70 ° C. and held for 1 hour. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-9) of polyurethane resin. The solid content concentration of this aqueous dispersion was 35.0%, and the amine value of the polyurethane resin was 30 mgKOH / g.

Comparative Example 2
Preparation of urethane prepolymer (II-9) A four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, among which "Bisol 3PN" (Note 2) (212.3 g), "Bisol 6PN "(Note 3) (305.9 g) and dimethylolpropionic acid (61.1 g) were dissolved in N-methylpyrrolidone (154.2 g), and hexamethylene diisocyanate (191.7 g) was added dropwise over 30 minutes. The reaction was carried out at 60 ° C. for 1.5 hours. Thereafter, the temperature was raised to 80 ° C. and reacted for 2 hours, isophorone diisocyanate (168.7 g) was added, and further reacted at 80 ° C. for 3 hours until the NCO value (Note 4) reached about 25 to 37. Thereafter, methyl ethyl ketone (418 g) was added to obtain a urethane prepolymer (II-9) solution. The obtained urethane prepolymer (II-9) solution had a solid content concentration of 62.2%, and the acid value of the prepolymer was 27.2 mgKOH / g.

Preparation of aqueous dispersion of polyurethane resin (III-10) Using a device similar to the above, a 62.6% urethane prepolymer (II-9) solution (1511 g) was kept at 50C while stirring. A 50% epoxy prepolymer (I-3) solution (753.6 g) was added thereto, and the mixture was stirred for 1 hour. It was then cooled to 40 ° C., neutralized with triethylamine (36.8 g), and deionized water (2392.6 g) was added and dispersed. Into this, diethylenetriamine (9.1 g) diluted with deionized water (91.3 g) was added dropwise over 30 minutes and held at 50 ° C. for 2 hours. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 60 ° C. to obtain an aqueous dispersion (III-10) of polyurethane resin. The solid content concentration of this aqueous dispersion was 35.0%, the acid value of the polyurethane resin was 19.4 mgKOH / g, the amine value was 8.1 mgKOH / g, and the hydroxyl value was 59.1 mgKOH / g.

Performance Evaluation The aqueous dispersion of each polyurethane resin obtained above was subjected to the following performance test and evaluated. The results are shown in Table 1.

Evaluation test method (* 1) Water resistance: Each composition was spray-coated on a steel plate so that the dry film thickness was 25 μm, and dried and heated under the drying conditions described in the table to prepare each test plate. . The obtained test plate was immersed in a constant temperature water bath at 20 ° C. for 7 days, and the state of the coating film was visually observed.

◎: No abnormality ○: Slight swelling and discoloration, but in good condition △: Swelling and discoloration, practically difficult ×: Significant swelling and discoloration

  (* 2) Salt stability: Weigh 100 g of each composition, add the same amount of 10% calcium chloride aqueous solution, and stir for 15 minutes. Thereafter, the mixture is filtered through a 200-mesh silk cloth, and the filtration residue is visually confirmed.

◎: No filtration residue ○: A slight residue remains △: A large amount of residue remains ×: Aggregates simultaneously with addition of aqueous calcium chloride solution

(* 3) Solvent extraction residue: Each composition was applied to a glass plate with a doctor blade to a dry film thickness of 25 μm, dried and heated under the drying conditions described in the table, and then from the glass plate. The dried film was peeled and cut into a size of 4 × 4 cm to obtain a test piece. The obtained test piece was immersed in acetone for 6 hours under reflux conditions. The solvent extraction residue was calculated as follows from the coating weight before and after extraction.
Solvent extraction residue (%) = (weight of membrane after extraction / weight of membrane before extraction) × 100 (%)

  (* 4) Corrosion resistance: Each test plate was prepared in the same manner as the water resistance (* 1), and the obtained test plate was cross-cut with a knife so as to reach the substrate, and this was applied to JIS Z-2371. In accordance with the above, a salt water spray test was conducted for 720 hours, and evaluation was made according to the following criteria based on rust and blister width from knife scratches.

A: Maximum width of rust and blisters is less than 1 mm from the cut part (one side)
○: The maximum width of rust and blisters is 1 mm or more and less than 2 mm from the cut part (one side)
Δ: The maximum width of the rust swelling is 2 mm or more and less than 3 mm (one side) from the cut portion, or blisters are observed on the entire coating surface. ×: The maximum width of rust and swelling is 3 mm or more from the cutting portion on the entire coating surface. Indicates that blistering is occurring

Examples 9-14
Using the aqueous dispersion of polyurethane resin obtained above, aqueous resin compositions shown in Table 2 below were obtained. Each aqueous resin composition was subjected to the performance test and evaluated. The results are shown in Table 2. (Note 5) to (Note 7) in the table are as follows.

(Note 5) Cymel 325: Cytec Industry, methylated melamine resin, solid content 80%
(Note 6) Water-dispersible polyisocyanate: 55 g of methoxypolyethylene glycol having a number average molecular weight of 550 and 504 g of “Takenate D170HN” (trimer of hexamethylene diisocyanate, manufactured by Mitsui Chemical Polyurethane Co., Ltd.) under the condition of 70 ° C. The reaction was continued until 4) reached 218 to obtain a water-dispersible polyisocyanate having a solid content of 100%.

  (Note 7) Block polyisocyanate: DURANATE TPA-100 (manufactured by Asahi Kasei, isocyanurate structure-containing polyisocyanate, number average molecular weight 600, isocyanate content 23.1%) 605 g and ethyl acetate 120 g were added and heated to 100 ° C. Then, 80 g of Oxocol C13 (manufactured by Kyowa Oil Chemical Co., Ltd., structural isomer of tridecanol) was added under a nitrogen stream, and kept at 100 ° C. for 2 hours. Thereafter, 345 g of diethyl malonate and 60 g of ethyl acetate were added and maintained at 60 ° C., then 7.0 g of a 28% methanol solution of sodium methoxide was added under a nitrogen stream, and the mixture was maintained at 60 ° C. for 12 hours. To 605 g of this reaction product, 488 g of 2-ethylhexanol was added, and the temperature was raised to 90 ° C. The solvent was distilled off for about 1.5 hours while maintaining the system temperature at 90 to 110 ° C. under reduced pressure to obtain a block polyisocyanate having a solid content of 100%.

Claims (12)

An epoxy prepolymer (I) having an amino group at the terminal obtained by the reaction of the polyepoxy compound (a) and the amine compound (b);
A polyurethane resin obtained by a reaction with a urethane prepolymer (II) having an isocyanate group at a terminal obtained by a reaction between a compound (c) having two or more hydroxyl groups in one molecule and a polyisocyanate compound (d). And
The polyurethane resin (III) in which the epoxy prepolymer (I) and / or the urethane prepolymer (II) has a polyoxyalkylene chain in the side chain is dispersed in water in an aqueous medium. An aqueous resin composition characterized by the above. The aqueous resin composition according to claim 1, wherein the amine compound (b) contains a polyoxyalkyleneamine as at least a part of its components. Obtained by reacting the epoxy prepolymer (I) such that the equivalent ratio of the epoxy group in the polyepoxy compound (a) to the amino group in the amine compound (b) is 1: 0.5 to 1: 2. The aqueous resin composition according to claim 1. The aqueous resin composition according to claim 1, wherein the compound (c) contains a polyol having a polyoxyalkylene chain in the side chain as at least a part of the component. The polyol having polyoxyalkylene in the side chain is at least one selected from a reaction product of an acrylate having a polyoxyalkylene chain and a dialkanolamine, and a reaction product of glycerin carbonate and a polyoxyalkyleneamine. 4. The aqueous resin composition according to 4. The aqueous resin composition according to claim 1, wherein the compound (c) contains a carboxyl group-containing diol as at least a part of its components. The aqueous resin composition according to claim 1, wherein the urethane prepolymer (II) further comprises a compound (e) containing two or more active hydrogen groups in one molecule and a tertiary amino group as a production raw material. The aqueous resin composition according to claim 1, wherein the urethane prepolymer (II) is obtained by reacting such that the equivalent ratio of isocyanate groups to hydroxyl groups in all components is 1: 0.5 to 1: 0.9. . The polyurethane resin (III) is reacted so that the equivalent ratio of the amino group in the epoxy prepolymer (I) and the isocyanate group in the urethane prepolymer (II) is 0.01: 1 to 0.9: 1. The aqueous resin composition according to claim 1 obtained by An aqueous coating composition comprising the aqueous resin composition according to any one of claims 1 to 9. A method for forming a coating film, comprising applying the aqueous coating composition according to claim 10 to a surface to be coated. A coated article formed by the method of claim 11.