Aqueous polyurethane resin composition and coating material using said composition

Abstract

An aqueous polyurethane resin composition is provided that not only has an excellent finished appearance but also has excellent impact resistance, such as chipping resistance and adhesion. The aqueous polyurethane resin composition comprises at least (a) at least two types of organic diisocyanate compounds and / or polyisocyanate compounds that are different from each other; (b) a polyol compound; (c) an acid group-containing compound comprising at least two types of compounds, wherein the compound containing a carboxyl group as an acid group (carboxyl group-containing compound) and the compound containing a sulfo group as an acid group (sulfo group-containing compound); and (d) a polyurethane resin obtained from a chain extender of a polyamine compound, a diamine compound, a polyol compound and / or an alkanolamine compound having a molecular weight of 400 or less, wherein the aqueous polyurethane resin composition has a viscosity of 500 Pa·s or more and 50,000 Pa·s or less when the polyurethane resin is contained in an amount of 65 weight%.

Description

Technology Field

[0001] The present invention relates to an aqueous polyurethane resin composition having an excellent finished appearance as well as excellent impact resistance, such as chipping resistance, and / or adhesion, and to a painting composition, coating composition, ink composition, or adhesive composition containing said aqueous polyurethane resin composition. Background Technology

[0002] Since aqueous polyurethane resin compositions have excellent adhesion to substrates, wear resistance, impact resistance, and solvent resistance, such aqueous polyurethane resin compositions are widely used as coating materials, inks, adhesives, and various coating agents for paper, plastics, films, metals, rubber, elastomers, textile products, etc. (Patent Literatures 1 to 3). In order to use aqueous polyurethane resin compositions for monocoating or multilayer coating on electrodeposited metal substrates, it is necessary to continuously improve the finished appearance, impact resistance, and adhesion.

[0003] List of cited literature

[0004] Patent Document 1: JP H08-209066 A

[0005] Patent Document 2: JP H07-166093 A

[0006] Patent Document 3: JP 2004-97917 A The problem to be solved

[0007] The object of the present invention is to provide an aqueous polyurethane resin composition having an excellent finished appearance, and additionally to provide an aqueous polyurethane resin composition having excellent impact resistance, such as chipping resistance, and adhesion. means of solving the problem

[0008] As a result of intensive research, the inventors have provided an acid group-containing compound comprising (a) at least two types of organic diisocyanate compounds and / or polyisocyanate compounds that are distinct from each other; (b) a polyol compound; and (c) at least two types of compounds comprising a compound containing a carboxyl group as an acid group (carboxyl group-containing compound) and a compound containing a sulfo group as an acid group (sulfo group-containing compound); and (d) a polyurethane resin obtained from a component comprising a chain extender selected from the group consisting of polyamine compounds, diamine compounds, polyol compounds, and alkanolamine compounds, having a molecular weight of 400 or less, wherein the polyurethane resin is contained in an amount of 65 weight%, if the aqueous polyurethane resin composition has a viscosity of 500 Pa·s or more and 50,000 Pa·s or less, it has been discovered that the aqueous polyurethane resin composition has an excellent finished appearance due to the excellent flow characteristics obtained by controlling the resin viscosity, even after the water volatilizes and the resin particles fuse and solidify (solid content: 65%) following application. Furthermore, the inventors have discovered that by adjusting the components of the aqueous polyurethane resin composition, it is possible to provide a coating film having both excellent adhesion to an electrodeposited film and excellent impact resistance, such as chipping resistance. Thus, the inventors have completed the present invention.

[0009] The present invention provides the following means of solution.

[0010] [1] An aqueous polyurethane resin composition comprising a polyurethane resin obtained from at least the following components (a) to (d):

[0011] (a) at least two types of organic diisocyanate compounds and / or polyisocyanate compounds that are different from each other;

[0012] (b) polyol compound;

[0013] (c) an acidic group-containing compound comprising at least two types of compounds, wherein the compound containing a carboxyl group as an acid group (carboxyl group-containing compound) and the compound containing a sulfo group as an acid group (sulfo group-containing compound); and

[0014] (d) a chain extender selected from the group consisting of polyamine compounds, diamine compounds, polyol compounds and alkanolamine compounds, having a molecular weight of 400 or less,

[0015] Here, when the polyurethane resin is contained in an amount of 65 weight%, the aqueous polyurethane resin composition has a viscosity of 500 Pa·s or more and 50,000 Pa·s or less.

[0016] Water-based polyurethane resin composition.

[0017] [2] An aqueous polyurethane resin composition in which the acidic group-containing compound of component (c) of [1] is a compound having two or more hydroxyl groups or amino groups.

[0018] [3] An aqueous polyurethane resin composition in which at least two types of organic diisocyanate compounds, which are different from each other, are included as component (a) in [1] or [2].

[0019] [4] An aqueous polyurethane resin composition in which, in any one of [1] to [3], the organic diisocyanate compound comprises at least one type of alicyclic diisocyanate compound.

[0020] [5] An aqueous polyurethane resin composition in which, in any one of [1] to [4], at least one type of organic diisocyanate compound is a diisocyanate compound selected from 4,4'-diisocyanatodicyclohexylmethane and isophorone diisocyanate, and the diisocyanate compound is contained in a percentage of 80 mol% or less based on 100 mol% of the organic diisocyanate compound of component (a).

[0021] [6] An aqueous polyurethane resin composition in which, in any one of [1] to [5], the polyol compound of component (b) contains a polyether polyol.

[0022] [7] An aqueous polyurethane resin composition in which, in any one of [1] to [6], component (b) is polytetramethylene glycol polyol.

[0023] [8] An aqueous polyurethane resin composition in which, in any one of [1] to [7], component (b) has an average molecular weight greater than 400 g / mol and less than or equal to 6000 g / mol.

[0024] [9] An aqueous polyurethane resin composition in which the percentage of component (b) contained in the polyurethane resin in any one of [1] to [8] is 60 weight% or more.

[0025]

[10] An aqueous polyurethane resin composition in which, in any one of [1] to [9], component (c) is present in the polyurethane resin in an amount such that the total weight of the carboxyl group-containing compound and the sulfo group-containing compound is 0.2 to 10 weight%, preferably 0.5 to 5 weight%.

[0026]

[11] An aqueous polyurethane resin composition in which, in any one of [1] to

[10] , the ratio of the acid value of the carboxyl group to the total acid value of component (c) is 0.20 to 0.95, more preferably 0.50 to 0.90, and more preferably 0.70 to 0.85.

[0027]

[12] An aqueous polyurethane resin composition in which, in any one of [1] to

[11] , the acid value of the carboxyl group in the polyurethane resin is preferably in the range of 4.5 to 30 mg KOH / g, more preferably in the range of 5 to 25 mg KOH / g, and more preferably in the range of 6 to 22 mg KOH / g.

[0028]

[13] An aqueous polyurethane resin composition in which, in any one of [1] to

[12] , the polyurethane resin is contained in a percentage of 20 to 65 weight percent.

[0029]

[14] A painting composition, coating composition, ink composition or adhesive composition containing an aqueous polyurethane resin composition according to any one of [1] to

[13] . Effects of the invention

[0030] According to the aqueous polyurethane resin composition of the present invention, it is possible to provide an aqueous polyurethane resin composition having an excellent finished appearance, and additionally to provide an aqueous polyurethane resin composition having excellent impact resistance, such as chipping resistance, and adhesion. Specific details for implementing the invention

[0031] The present invention provides an aqueous polyurethane resin composition comprising: (a) at least two types of organic diisocyanate compounds and / or polyisocyanate compounds that are different from each other; (b) a polyol compound; (c) an acid group-containing compound comprising at least two types of compounds, wherein the compound containing a carboxyl group as an acid group (carboxyl group-containing compound) and the compound containing a sulfo group as an acid group (sulfo group-containing compound); and (d) a polyurethane resin obtained from a chain extender selected from the group consisting of polyamine compounds, diamine compounds, polyol compounds and alkanolamine compounds, and having a molecular weight of 400 or less, wherein the aqueous polyurethane resin composition has a viscosity of 500 Pa·s or more and 50,000 Pa·s or less when the polyurethane resin is contained in an amount of 65 weight%.

[0032] [Component (a): Organic diisocyanate compounds and polyisocyanate compounds]

[0033] In the present invention, component (a) is at least two types of organic diisocyanate compounds and / or polyisocyanate compounds that are different from each other.

[0034] The organic diisocyanate compound of component (a) is an organic compound having two free isocyanate groups per molecule, and diisocyanate Y(NCO)2[where Y is C 4-12 Divalent aliphatic hydrocarbon group (= aliphatic diisocyanate compound), C 6-15 Divalent alicyclic hydrocarbon group (= alicyclic diisocyanate compound), C 6-15 divalent aromatic hydrocarbon group (= aromatic diisocyanate compound) or C 7-15 It can be exemplified by the ar aliphatic hydrocarbon group. Examples of these organic diisocyanate compounds include tetramethylene diisocyanate, methylpentamethylene diisocyanate, 1,5-pentamethylene diisocyanate, hexamethylene diisocyanate (= HDI), dodecamethylene diisocyanate, 1,2-bis(isocyanatomethyl)cyclohexane, 1,4-diisocyanatocyclohexane, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (= IPDI, isophorone diisocyanate), 4,4'-diisocyanatodicyclohexylmethane, 4,4'-diisocyanatodicyclohexylpropane-(2,2), 1,4-diisocyanatobenzene, and 2,4-diisocyanatotoluene. It includes 2,6-diisocyanatoluene, 4,4'-diisocyanatodiphenylmethane, 2,2'-diisocyanatodiphenylmethane, 2,4'-diisocyanatodiphenylmethane, tetramethylxylylene diisocyanate, p-xylylene diisocyanate, p-isopropylidene diisocyanate, and 1,5-diisocyanatonaphthalene.

[0035] The organic polyisocyanate compound of component (a) is a polyisocyanate having three or more isocyanate groups per molecule. Such organic polyisocyanate compounds are prepared by the modification of aliphatic, alicyclic, araliphatic, and / or aromatic diisocyanates, for example, composed of at least two types of diisocyanates, and may be exemplified by polyisocyanates having structures of uretdione, isocyanurate, urethane, allophanate, biuret, carbodiimide, iminooxadiazinedione, and / or oxadiazinetrione. Examples of unmodified polyisocyanates having three or more isocyanate groups per molecule include 4-isocyanatomethyl-1,8-octane diisocyanate (nonane triisocyanate).

[0036] Component (a) preferably comprises at least two types of organic diisocyanate compounds that are different from each other.

[0037] In order for the coating film to have high breaking strength and improved durability, the organic diisocyanate compound of component (a) preferably comprises at least one type of alicyclic diisocyanate compound.

[0038] To facilitate reaction control, component (a) preferably comprises at least one type of alicyclic diisocyanate compound selected from 4,4'-diisocyanatodicyclohexylmethane and isophorone diisocyanate.

[0039] Component (a) contains a cycloaliphatic diisocyanate compound in a percentage of preferably 80 mol% or less, more preferably 20 to 70 mol%, and even more preferably 40 to 60 mol%, based on 100 mol% of the organic diisocyanate compound of component (a). Since the cycloaliphatic diisocyanate compound can reduce impact resistance, such as chipping resistance, in some cases if its proportion among the organic diisocyanate compounds is too high, the cycloaliphatic diisocyanate compound is preferably present within the range specified above.

[0040] Component (a) is preferably a combination of alicyclic diisocyanate compounds and aliphatic diisocyanate compounds selected from 4,4'-diisocyanatodicyclohexylmethane, isophorone diisocyanate and mixtures thereof.

[0041] Component (a) is more preferably a combination of a diisocyanate compound selected from 4,4'-diisocyanatodicyclohexylmethane or isophorone diisocyanate and an aliphatic diisocyanate compound, hexamethylene diisocyanate (= HDI).

[0042] The component (a) contained in the polyurethane resin is, in percentage, typically 5 to 30 weight%, preferably 10 to 25 weight%, more preferably 13 to 20 weight%.

[0043] [Component (b): Polyol Compound]

[0044] The polyol compound of component (b) has a molecular weight greater than 400 and has at least two isocyanate-reactive hydroxyl groups. Examples of polyol compounds include polyether polyols, polyester polyols, polycarbonate polyols, polyester polycarbonate polyols, polylactone polyols, polybutadiene polyols, and silicone polyols.

[0045] The preferred component (b) preferably has 2 to 4 hydroxyl groups, particularly preferably 2 to 3, and most preferably 2 hydroxyl groups. Furthermore, the component (b) may also be a mixture of various compounds of this type.

[0046] Examples of polyether polyols include cyclic ether adducts and polyhydric alcohol condensates. Examples of cyclic ethers include styrene oxide, ethylene oxide, propylene oxide, tetrahydrofuran, butylene oxide, and epichlorohydrin, which may be used alone or in combination. Examples of polyhydric alcohols include the aforementioned diols and highly functional polyols, which may be used alone or in combination. For example, a tetrahydrofuran adduct is known as polytetramethylene ether glycol (PTMG).

[0047] Polyester polyols can be produced by adjusting the manufacturing conditions of the polyester and are polyesters having hydroxyl groups at at least both ends of the main chain. Examples of polyester polyols include linear polyester diols and some branched polyester polyols. These can be produced by known methods using aliphatic, alicyclic, or aromatic dicarboxylic acids and diols, and optionally using polycarboxylic acids and / or highly functional polyols.

[0048] Polylactone polyols are homopolymers or copolymers of lactones, which are polylactones prepared to have hydroxyl groups at at least both ends of the main chain.

[0049] Polycarbonate polyol is a polycarbonate having hydroxyl groups at at least both ends of the main chain, produced by adjusting the manufacturing conditions of the polycarbonate.

[0050] Silicone polyols include silicone oils having hydroxyl groups at the ends that have siloxane bonds within the molecule.

[0051] The polyol compound of component (b) preferably includes a polyether polyol.

[0052] When component (b) comprises a polyether polyol, the polyether polyol contained in component (b) is, in percentage, preferably 50 to 100 weight%, more preferably 60 to 100 weight%, and even more preferably 75 to 100 weight%. When the content percentage is 50% or more, the strength is increased. Additionally, an optional component, such as a polycarbonate polyol, may be used in combination, and its content percentage is 50 weight% or less, preferably 40 weight% or less, and even more preferably 25 weight% or less.

[0053] The average molecular weight of the polyol compound of component (b), in particular the average molecular weight of the polytetramethylene glycol polyol, is greater than 400 g / mol and less than or equal to 6000 g / mol, preferably 800 to 5000 g / mol, more preferably 1000 to 4000 g / mol. When the average molecular weight is greater than 400 g / mol, sufficient adhesion of the coating film to the substrate can be obtained. When the average molecular weight is less than or equal to 6000 g / mol, the dispersion stability of the aqueous polyurethane resin composition and / or the finished appearance of the coating film can be improved.

[0054] In terms of the adhesion of the coating film, the component (b) contained in the polyurethane resin is, in percentage, preferably 60% by weight or more, more preferably 65% ​​to 85% by weight, and even more preferably 70% to 85% by weight.

[0055] In this specification, it should be noted that the polyol compound of component (b) excludes the acid group-containing diol compound of component (c).

[0056] [Component (c): Acid group-containing compound]

[0057] The acid group-containing compound of component (c) comprises at least two types of compounds, which are a compound containing a carboxyl group as an acid group (carboxyl group-containing compound) and a compound containing a sulfo group as an acid group (sulfo group-containing compound).

[0058] The acidic group-containing compound of component (c) is preferably a compound having at least two hydroxyl groups or amino groups.

[0059] The combination of a carboxyl group-containing compound and a sulfo group-containing compound for component (c) improves the emulsification / dispersibility of polyurethane resin in water even at low acid values. Furthermore, when the combination is mixed with other emulsion resins, pigments, additives, solvents, etc. and used as a coating material, the mixture has excellent storage stability and is stable at low viscosity despite high solid content.

[0060] Component (c) is present in the polyurethane resin in an amount such that the total weight of the carboxyl group-containing compound and the sulfo group-containing compound is preferably 0.2 to 10 weight%, more preferably 0.5 to 5 weight%. When the amount is 0.2 weight% or more, sufficient water dispersibility is obtained. When the amount is 10 weight% or less, the strength and water resistance of the coating film are improved.

[0061] The ratio of the acid value of the carboxyl group to the total acid value of component (c) is preferably 0.20 to 0.95, more preferably 0.50 to 0.90, and even more preferably 0.70 to 0.85. In this invention, the acid value represents a calculated value (mg KOH / g) expressed as the number of mg of potassium hydroxide required to neutralize the carboxyl group or sulfo group present in the polyurethane resin. The total acid value represents the total sum of the acid values ​​of the carboxyl group and the sulfo group.

[0062] Specific examples of acidic group-containing compounds of component (c) include N-(2-aminoethyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-3-aminopropanesulfonic acid, N-(2-aminoethyl)-3-aminopropanesulfonic acid, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, N,N-bishydroxyethylalanine, 3,4-dihydroxybutanesulfonic acid, 3,6-dihydroxy-2-toluenesulfonic acid, and sodium salts, lithium salts, potassium salts, tertiary amine salts, etc., which are reaction products obtained by the Michael addition of a diamine (e.g., 1,2-ethanediamine or isophorone diamine) and 2 molar amounts of acrylic acid or maleic acid.

[0063] The acid group-containing compound of component (c) is preferably an acid group-containing diol compound having 4 to 12 carbon atoms, such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, N,N-bishydroxyethylglycine, N,N-bishydroxyethylalanine, 3,4-dihydroxybutanesulfonic acid and 3,6-dihydroxy-2-toluenesulfonic acid.

[0064] The acidic group-containing compound of component (c) may be one containing an ionic group, such as dihydroxycarboxylic acid, diaminocarboxylic acid, dihydroxysulfonic acid, diaminosulfonic acid and its salts, or one capable of forming an ionic group. Examples thereof are dimethylolpropionic acid, hydroxypivalic acid, 2-(2-aminoethylamino)ethanesulfonic acid, ethylenediaminepropyl or butylsulfonic acid, 1,2- or 1,3-propylenediamine-β-ethylsulfonic acid, lysine, 3,5-diaminobenzoic acid and its alkali and / or ammonium salts; It includes the adduct of sodium hydrogen sulfate to butene-2-diol-1,4, the propoxylated adduct of polyethersulfone, 2-butenediol and NaHSO3 (German Patent Specification DE-A 24 46 440), and, for example, a structural unit that can be converted into a cationic group, such as N-methyldiethanolamine.

[0065] [Component (d): Polyamine compound, diamine compound, polyol compound and alkanolamine compound as a chain extender]

[0066] Component (d) is a polyamine compound, diamine compound, polyol compound and / or alkanolamine compound as a chain extender, and the molecular weight of these compounds is 400 or less.

[0067] The polyamine compound of component (d) is a polyamine having a total of three or more amino groups and / or imino groups within one molecule. Examples of polyamine compounds include triamine compounds such as diethylenetriamine, bis(2-aminopropyl)amine and bis(3-aminopropyl)amine; tetramine compounds such as triethylenetetramine, tripropylenetetramine, N-(benzyl)triethylenetetramine, N,N"'-(dibenzyl)triethylenetetramine and N-(benzyl)-N"'-(2-ethylhexyl)triethylenetetramine; pentamine compounds such as tetraethylenepentamine and tetrapropylenepentamine; hexamine compounds such as pentaethylenehexamine and pentapropylenehexamine; and polyamine compounds such as polyethyleneimine and polypropyleneimine. In terms of reactivity with the polyurethane prepolymer, the polyamine is preferably a polyamine having two amino groups and one or more imino groups, such as diethylenetriamine, triethylenetetramine, bis(2-aminopropyl)amine, bis(3-aminopropyl)amine, tripropylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, pentaethylenehexamine, or pentapropylenehexamine.

[0068] Examples of diamine compounds of component (d) include hydrazine, 1,2-ethanediamine, 1,4-tetramethylenediamine, 2-methyl-1,5-pentanediamine, 1,6-hexamethylenediamine, 1,4-hexamethylenediamine, 3-aminomethyl-3,5,5-trimethylcyclohexylamine, 1,3-bis(aminomethyl)cyclohexane, xylylenediamine, piperazine, 2,5-dimethylpiperazine, etc.

[0069] The polyol compound of component (d) is a compound having two or more hydroxyl groups. His examples are ethanediol, diethylene glycol, triethylene glycol and tetraethylene glycol, 1,2-propanediol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-dihydroxycyclohexane, 1,4-dimethylcyclohexane, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, neopentyl glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-dihydroxybenzene, It includes 1,3-dihydroxybenzene, 1,2-dihydroxybenzene, 2,2-bis(4-hydroxyphenyl)-propane (bisphenol A), TCD-diol, trimethylolpropane, glycerol, pentaerythritol, and dipentaerythritol.

[0070] Examples of alkanolamine compounds of component (d) include ethanolamine, propanolamine, butylethanolamine, 1-amino-2-methyl-2-propanol, 2-amino-2-methylpropanol, diethanolamine, diisopropanolamine, dimethylaminopropylethanolamine, dipropanolamine, N-methylethanolamine, N-ethylethanolamine, etc.

[0071] As a chain extender of component (d), one type may be used alone, or multiple types may be used in combination.

[0072] The amount of the chain extender of component (d) is preferably less than or equal to the equivalent of the residual isocyanate group that is the source of chain extension in the polyurethane prepolymer, more preferably 0.7 to 0.99 equivalents of the residual isocyanate group. When the amount of the chain extender of component (d) is less than or equal to the equivalent of the residual isocyanate group, preferably 0.99 equivalents or less, the decrease in the molecular weight of the chain-extended polyurethane resin tends to be suppressed, and the strength of the coating film obtained by applying the resulting aqueous polyurethane resin dispersion tends to be improved.

[0073] In addition to component (d), for example, amino polyol compounds, water, etc., may be used as additional chain extenders.

[0074] The aqueous polyurethane resin composition may include monoalcohol and monoamine as additional optional components.

[0075] The amount of monoalcohol and monoamine added is preferably less than 5 weight%, more preferably less than 2 weight%, based on the solid content of the aqueous polyurethane resin.

[0076] [Method for preparing an aqueous polyurethane resin composition]

[0077] The method for preparing an aqueous polyurethane resin composition is not particularly limited, but examples thereof include the following methods.

[0078] A method for preparing an aqueous polyurethane resin composition comprises the steps of: (a) obtaining a polyurethane prepolymer by reacting at least two different types of organic diisocyanate compounds and / or polyisocyanate compounds, (b) a polyol compound, and (c) an acid group-containing compound; neutralizing the acid groups in the polyurethane prepolymer; dispersing the polyurethane prepolymer in an aqueous medium; and (d) obtaining an aqueous polyurethane resin composition comprising a polyurethane resin by reacting the polyurethane prepolymer with a chain extender selected from the group consisting of polyamine compounds, diamine compounds, polyol compounds, and alkanolamine compounds, having a molecular weight of 400 or less.

[0079] In a method for preparing an aqueous polyurethane resin composition, the step of neutralizing acidic groups and the step of dispersing a polyurethane prepolymer in an aqueous medium may be performed separately or together. In a method for preparing an aqueous polyurethane resin composition, the step of reacting a chain extender with a polyurethane prepolymer may be performed after the step of dispersing the polyurethane prepolymer in an aqueous medium or together with the step of dispersing the polyurethane prepolymer in an aqueous medium.

[0080] Each step of the method for preparing an aqueous polyurethane resin composition can be performed under an inert gas atmosphere or in the atmosphere.

[0081] The polyurethane resin composition of the present invention is preferably a dispersion dispersed in an aqueous medium comprising a polyurethane resin. The polyurethane resin composition of the present invention comprises water as at least the aqueous medium and may contain an organic solvent as a co-solvent [ketone-based solvent (e.g., acetone and methyl ethyl ketone), ester-based solvent (e.g., ethyl acetate), ether-based solvent (e.g., tetrahydrofuran), amide-based solvent (e.g., N,N-dimethylformamide and N-methylpyrrolidone), alcohol-based solvent (e.g., isopropyl alcohol), and aromatic hydrocarbon-based solvent (e.g., toluene, etc.)]. The amount of the co-solvent contained in the polyurethane resin composition of the present invention is preferably 10 weight% or less. Furthermore, the proportion of water in the aqueous medium is preferably 40 weight% or more.

[0082] From the perspective of easy handling of the aqueous dispersion, the solid content concentration (content of components other than volatile components) of the aqueous dispersion of the aqueous polyurethane resin obtained in the present invention is preferably 20 to 65 weight%, more preferably 30 to 60 weight%. The solid content concentration can be obtained as follows: about 1 g of the aqueous dispersion is spread thinly on a Petri dish; the aqueous dispersion is accurately weighed; then, the weight is accurately weighed after heating at 130°C for 45 minutes using a circulating constant temperature dryer; and the ratio (percentage) of the residual weight after heating to the weight before heating is calculated.

[0083] Aqueous polyurethane resin compositions may contain a neutralizing agent as an optional component. The neutralizing agent is used to neutralize at least some of the acidic groups of the polyurethane prepolymer and to disperse the polyurethane prepolymer in an aqueous medium. Examples of neutralizing agents include tertiary amine compounds such as trialkylamines including trimethylamine, triethylamine, tributylamine, etc., N,N-dialkylalkanolamines including N,N-dimethylethanolamine, N,N-dimethylpropanolamine, N,N-dipropylethanolamine, 1-dimethylamino-2-methyl-2-propanol, etc., N-alkyl-N,N-dialkanolamines, and trialalkanolamines including triethanolamine; inorganic alkali salts such as potassium hydroxide and sodium hydroxide; and ammonia, etc. These may be used alone or in combination of two or more.

[0084] In terms of workability, the neutralizing agent is preferably an organic amine, more preferably N,N-dimethylethanolamine. The amount of the neutralizing agent is, for example, 0.4 to 1.2 equivalents, preferably 0.6 to 1.0 equivalents, per equivalent of the acidic group retained by the aqueous polyurethane resin composition.

[0085] The aqueous polyurethane resin composition of the present invention has a viscosity of 500 Pa·s or more and 50,000 Pa·s or less when the polyurethane resin is contained in an amount of 65 weight%. When the polyurethane resin is contained in an amount of 80 weight%, the viscosity change rate is 350% or less, preferably 250% or less, and particularly preferably 150% or less. By having the viscosity specified above, the aqueous polyurethane resin composition of the present invention provides a painting composition, a coating composition, an ink composition, and an adhesive composition having an excellent finished appearance.

[0086] In this specification, the viscosity of an aqueous polyurethane resin composition when the solid content is high is measured using a rheometer after adjusting the liquid temperature to 25°C. It should be noted that when the polyurethane resin is contained in an amount of less than 65% by weight in the aqueous polyurethane resin composition, it is possible to measure the viscosity when the polyurethane resin is contained in an amount of 65% by weight or more by adjusting the amount of polyurethane resin contained by evaporating the aqueous medium in the aqueous polyurethane resin composition, for example, using an evaporator.

[0087] [Viscosity change rate]

[0088] In the present invention, "viscosity change rate" represents the change in viscosity when the solid content of the aqueous polyurethane resin composition increases from 65 weight% to 80 weight%, and is determined by the following calculation method. It should be noted that for the viscosity when the solid content is high, the value measured by a rheometer at 25°C is used.

[0089] (Percentage change in viscosity (%)) = {(Viscosity at 80 wt% solid content) - (Viscosity at 65 wt% solid content)} / (Viscosity at 65 wt% solid content) x 100

[0090] The average molecular weight of the polyurethane resin in the aqueous polyurethane resin composition of the present invention is not particularly limited and can be selected within a range that provides excellent dispersibility and a coating film as an aqueous coating material, preferably 5,000 to 500,000, more preferably 10,000 to 100,000. In this specification, the average molecular weight of the polyurethane resin is the weight-average molecular weight measured by gel permeation chromatography, and polystyrene is used as a standard material.

[0091] In the aqueous polyurethane resin composition of the present invention, the acid value of the carboxyl groups in the polyurethane resin is preferably in the range of 4.5 to 30 mg KOH / g, more preferably in the range of 5 to 25 mg KOH / g, and even more preferably in the range of 6 to 22 mg KOH / g. In this specification, the acid value of the resin refers to the number of mg of potassium hydroxide required to neutralize 1 g of resin. The acid value is a value measured according to the indicator titration method of JIS K 1557.

[0092] In the aqueous polyurethane resin composition of the present invention, the hydroxyl value of the polyurethane resin is not particularly limited, but is typically in the range of 1 to 100 mg KOH / g. In this specification, the hydroxyl value of the resin refers to the number of milligrams (mg) of potassium hydroxide corresponding to hydroxyl groups in 1 g of resin. The hydroxyl value is a value measured according to the indicator titration method of Method B of JIS K 1557.

[0093] The aqueous polyurethane resin composition of the present invention may be used alone or in combination with binders, auxiliary agents, and additives known in the field of coating and adhesive technology (in particular, emulsifiers, light stabilizers such as UV absorbers and sterically hindered amines (HALS), antioxidants, fillers, auxiliary agents such as antisettling agents, defoaming agents and / or wetting agents, flow improvers, reactive diluents, plasticizers, neutralizing agents, catalysts, auxiliary solvents and / or thickeners, as well as additives such as pigments, colorants, or matting agents). A tackifier may also be added. Additives may be added to the product of the present invention immediately before processing. However, it is also possible to add at least a portion of the additives before or during the dispersion of the binder.

[0094] [Painting compositions containing water-based polyurethane resin compositions, etc.]

[0095] In addition, the present invention relates to a painting composition, a coating composition, an ink composition, and an adhesive composition containing the aqueous polyurethane resin composition described above.

[0096] In addition to the aqueous polyurethane resin composition, other resins may be added to the painting composition, coating composition, ink composition, and adhesive composition of the present invention.

[0097] Other examples of resins include polyester resin, acrylic resin, polyether resin, polycarbonate resin, polyurethane resin, epoxy resin, alkyd resin, polyolefin resin, vinyl chloride resin, etc. These may be used alone or in combination of two or more types.

[0098] In terms of water dispersibility, another resin preferably has one or more types of hydrophilic groups. The hydrophilic groups include hydroxyl groups, carboxyl groups, sulfo groups, polyethylene glycol groups, etc.

[0099] Polyester resins can typically be manufactured by esterification or transesterification between an acid component and an alcohol component. As the acid component, compounds commonly used as acid components in the manufacture of polyester resins may be used. For example, aliphatic polybasic acids, alicyclic polybasic acids, aromatic polybasic acids, etc., may be used as acid components.

[0100] The acrylic resin is preferably, for example, a hydroxyl group-containing acrylic resin. The hydroxyl group-containing acrylic resin may be prepared by known methods, e.g., a solution polymerization method in an organic solvent or an emulsion polymerization method in water, wherein a hydroxyl group-containing polymerizable unsaturated monomer is copolymerized with another polymerizable unsaturated monomer capable of copolymerizing with the hydroxyl group-containing polymerizable unsaturated monomer.

[0101] Hydroxyl group-containing polymerizable unsaturated monomers are compounds having one or more hydroxyl groups and one or more polymerizable unsaturated bonds within a single molecule. Examples thereof include monoesterified products from (meth)acrylic acid and dihydric alcohols having 2 to 8 carbon atoms, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; ε-caprolactone modified products of these monoesterified products; N-hydroxymethyl (meth)acrylamide; allyl alcohols; (meth)acrylates having a polyoxyethylene chain with a hydroxyl group at the molecular end, etc.

[0102] The hydroxyl group-containing acrylic resin preferably has an anionic functional group. The hydroxyl group-containing acrylic resin having an anionic functional group can be prepared, for example, by using a polymerizable unsaturated monomer having an anionic functional group such as a carboxylic acid group, a sulfonic acid group, or a phosphate group as a type of polymerizable unsaturated monomer.

[0103] Examples of polyether resins include polymers or copolymers having ether bonds, such as polyoxyethylene-based polyethers, polyoxypropylene-based polyethers, polyoxybutylene-based polyethers, and polyethers derived from aromatic polyhydroxy compounds including bisphenol A, bisphenol F, etc.

[0104] Examples of polycarbonate resins include polymers prepared from bisphenol A, 3-methyl-1,5-pentanediol, and 1,6-hexanediol.

[0105] Examples of epoxy resins include resins obtained by the reaction of a bisphenol compound with epichlorohydrin, etc. Examples of bisphenol include bisphenol A and bisphenol F.

[0106] Examples of alkyd resins include alkyd resins obtained by reacting, for example, a polybasic acid such as phthalic acid, terephthalic acid, or succinic acid and a polyhydric alcohol with a modifier such as a fat and oil / fat and oil acid (soybean oil, flaxseed oil, palm oil, stearic acid, etc.) or a natural resin (rosin, succinate, etc.).

[0107] Examples of polyolefin resins include a polyolefin resin obtained by appropriately polymerizing or copolymerizing an olefin-based monomer with another monomer according to a conventional polymerization method, or a resin obtained by applying the polyolefin resin to a water dispersion using an emulsifier, or by appropriately emulsion polymerizing an olefin-based monomer with another monomer. Furthermore, in some cases, a so-called chlorinated polyolefin-modified resin obtained by chlorinating a polyolefin resin may be used.

[0108] Examples of olefin-based monomers include α-olefins such as ethylene, propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-hexene, 1-decene, and 1-dodecene; and conjugated and unconjugated dienes such as butadiene, ethylidene norbornene, dicyclopentadiene, 1,5-hexadiene, and styrene. These monomers may be used alone or in combination of two or more.

[0109] Examples of other monomers copolymerizable with olefin-based monomers include vinyl acetate, vinyl alcohol, maleic acid, citraconic acid, itaconic acid, maleic anhydride, citraconic anhydride, and itaconic anhydride. These monomers may be used alone or in combination of two or more.

[0110] The painting composition, coating composition, ink composition, and adhesive composition of the present invention may further include a curing agent. By including a curing agent, it is possible to improve the durability of a painting film, multilayer painting film, coating film, or printed material obtained using the coating composition, ink composition, or adhesive composition.

[0111] For example, polyisocyanates, blocked polyisocyanates, melamine resins, carbodiimide, oxazoline, aziridine, hydrazine, etc., may be used as curing agents. It should be noted that these curing agents may be used alone or in combination of two or more.

[0112] Polyisocyanates are not particularly limited as long as the polyisocyanate has two or more isocyanate groups in the molecule, and examples thereof include those identical to those exemplified as polyisocyanate compounds (a).

[0113] Blocked polyisocyanates are not particularly limited as long as the blocked polyisocyanate has two or more blocked isocyanate groups within the molecule, and examples thereof include a polyisocyanate compound (a) blocked by a known blocking agent [phenol, secondary or tertiary alcohol, oxime, aliphatic or aromatic secondary amine, phthalate imide, lactam, active methylene compound (malonic acid dialkyl ester, etc.), pyrazole-based compound (pyrazole, 3,5-dimethylpyrazole, etc.), sodium bisulfite, etc.] or a compound obtained by providing hydrophilicity to the polyisocyanate compound (a).

[0114] The melamine resin is not particularly limited, and any commonly used as a curing agent may be used. For example, the melamine resin is preferably an alkyl etherified melamine resin obtained by alkyl etherification, more preferably a melamine resin substituted with methoxy groups and / or butoxy groups. Such melamine resins are those having only methoxy groups, such as Cymel 325, Cymel 327, Cymel 370, and My Coat 723; These include those having both methoxy groups and butoxy groups, such as Cimel 202, Cimel 204, Cimel 211, Cimel 232, Cimel 235, Cimel 236, Cimel 238, Cimel 251, Cimel 254, Cimel 266, Cimel 267, and Cimel 285 (all are trademarks of Nippon Cytec Industries, Ltd.); and those having only butoxy groups, such as MyCoat 506 (trademark of Mitsui-Cytec Ltd.), U-VAN 20N60, and U-VAN 20SE (all are trademarks of Mitsui Chemicals, Inc.). These may be used alone or in combination of two or more. Among these, Simel 211, Simel 251, Simel 285, Simel 325, Simel 327, and Mycot 723 are more preferred.

[0115] Carbodiimide is not particularly limited as long as the carbodiimide is a compound having two or more carbodiimide groups in the molecule. For example, an aliphatic polycarbodiimide [poly(hexamethylenecarbodiimide), etc.], an aliphatic polyisocyanate having 8 to 26 carbon atoms, an aliphatic polyisocyanate having 4 to 22 carbon atoms, an alicyclic polyisocyanate having 8 to 18 carbon atoms, or an ar aliphatic polyisocyanate having 10 to 18 carbon atoms obtained by polymerizing an aromatic polyisocyanate having 8 to 26 carbon atoms, an aliphatic polyisocyanate having 4 to 22 carbon atoms, an alicyclic polycarbodiimide [poly(4,4'-dicyclohexylmethanecarbodiimide), etc.] and an aromatic polycarbodiimide [poly(p-phenylenecarbodiimide), poly(4,4'-diphenylmethanecarbodiimide), poly(diisopropylphenylcarbodiimide), etc.] may be used. "Carbodilite V-01", "Carbodilite V-02", "Carbodilite V-03", "Carbodilite V-04", "Carbodilite V-05", "Carbodilite V-07", "Carbodilite V-09", "Carbodilite E-02", "Carbodilite E-03A", "Carbodilite E-04", etc. manufactured by Nisshinbo Chemical Inc. may be listed as commercially available products.

[0116] Oxazoline is not particularly limited, insofar as oxazoline is a compound having two or more oxazoline groups (oxazoline backbone) within the molecule. Examples thereof include compounds having two or more oxazoline groups, e.g., 2,2'-isopropylidenebis(4-phenyl-2-oxazoline); (co)polymers of polymerizable oxazoline compounds, e.g., 2-isopropenyl-2-oxazoline, 2-vinyl-2-oxazoline, and 2-vinyl-4-methyl-2-oxazoline; It includes copolymers of polymerizable oxazoline compounds and copolymers of copolymer monomers that do not react with oxazoline groups [(meth)acrylic acid esters, e.g., methyl (meth)acrylate, ethyl (meth)acrylate, hydroxyethyl (meth)acrylate and polyethylene glycol (meth)acrylate, (meth)acrylate amide vinyl acetate, styrene, α-methylstyrene sodium styrenesulfonate, etc.]. "Epocros K-2010E", "Epocros K-2020E" and "Epocros WS-500" manufactured by Nippon Shokubai Co., Ltd. may be listed as commercially available products.

[0117] Aziridine is not particularly limited as long as aziridine is a compound having two or more aziridinyl groups in the molecule. Examples thereof include tetramethylolmethane tris(β-aziridinylpropionate) and trimethylolpropane tris(β-aziridinylpropionate).

[0118] Hydrazines include hydrazine and compounds having two or more hydrazine groups (hydrazine backbone) within the molecule [e.g., dicarboxylic acid dihydrazides having 2 to 10 carbon atoms (oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide, etc.) and alkylene dihydrazines having 2 to 10 carbon atoms (ethylene dihydrazine, 1,3-propylene dihydrazine, 1,4-butylene dihydrazine, 1,6-hexylene dihydrazine, etc.)].

[0119] Coloring pigments, extender pigments, and luminous pigments may be added to the painting composition, coating composition, and ink composition of the present invention.

[0120] Examples of coloring pigments include titanium oxide, zinc white, carbon black, molybdenum red, Prussian blue, cobalt blue, azo pigments, phthalocyanine pigments, quinacridone pigments, isoindoline pigments, selenium-based pigments, perylene pigments, etc. It is preferable to use titanium oxide and / or carbon black as coloring pigments. It should be noted that these may be used alone or in combination of two or more types.

[0121] Examples of extender pigments include clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, talc, silica, and alumina white. It is preferable to use barium sulfate and / or talc as extender pigments, and more preferably, barium sulfate is used. It should be noted that these may be used alone or in combination of two or more.

[0122] For example, aluminum, copper, zinc, brass, nickel, aluminum oxide, mica, aluminum oxide coated with titanium oxide or iron oxide, or mica coated with titanium oxide or iron oxide can be used as a luminous pigment.

[0123] The painting composition, coating composition, ink composition, and adhesive composition of the present invention may contain conventional additives, such as thickeners, curing catalysts, ultraviolet absorbers, light stabilizers, defoaming agents, plasticizers, surface conditioners, and antisettling agents, depending on their function or use. It should be noted that these may be used alone or in combination of two or more, or that commercially available products may be used as they are.

[0124] The method for preparing the painting composition, coating composition, ink composition, or adhesive composition of the present invention is not particularly limited, and known manufacturing methods may be adopted. However, the painting composition, coating composition, ink composition, and adhesive composition are suitably prepared by mixing an aqueous polyurethane resin composition with the various resins and additives mentioned above, additionally adding an aqueous medium, and adjusting the viscosity to suit the application method.

[0125] Suitable materials to which the painting composition, coating composition, ink composition, and adhesive composition of the present invention are applied include metallic materials commonly used for automobile bodies or parts, road materials, housing construction materials, etc. (e.g., electrodeposited-coated steel sheets, phosphate-treated steel sheets, galvanized steel sheets, cold-rolled steel sheets, aluminum sheets, stainless steel sheets, zinc phosphate-treated steel sheets, iron phosphate-treated steel sheets, etc.); or plastic materials such as polyurethane, polycarbonate, polybutylene terephthalate, polyamide, polyphenylene oxide, acrylonitrile / butadiene / styrene copolymer (i.e., ABS resin), polypropylene, and unsaturated polyester (generally abbreviated as SMC). However, the present invention is not limited thereto.

[0126] The material may be used as is or applied to surface treatments, such as degreasing or primer painting and / or intermediate painting. These treatments may be performed alone or in combination of two or more.

[0127] In order to repair a multilayer coating film previously applied to a material using the painting composition, coating composition, ink composition, or adhesive composition of the present invention, it is preferable to first apply solvent cleaning or sanding treatment to the portion of the coating film requiring repair, and then apply painting.

[0128] The painting composition, coating composition, ink composition, and adhesive composition of the present invention may be adjusted to have a specific viscosity suitable for conventional coating methods, such as air spray, airless spray, or electrostatic coating, or for obtaining a desired film thickness, before use. For example, to coat a plastic material, the water-based painting composition is preferably adjusted to have about 10 to 40 weight% solid content and about 800 to 5,000 cps / 6 rpm viscosity (measured by a Type B viscometer) by adding deionized water and, if necessary, additives such as thickeners and defoamers before use.

[0129] Although the suitable material mentioned above may be coated as a monocoat of the painting composition, coating composition, ink composition, or adhesive composition of the present invention, an intermediate coating material may be applied on the coating material to which the painting composition, coating composition, ink composition, or adhesive composition of the present invention is applied by the so-called wet-on-wet method or the wet-on-wet method after preheating. Meanwhile, after the coating material of the painting composition, coating composition, ink composition, or adhesive composition of the present invention is applied to the electrodeposition film, a top coating may be performed by the wet-on-wet method or the wet-on-wet method after preheating. Preheating is a method of heating at 40 to 80°C for 5 to 60 minutes, for example, at 80°C for 5 minutes, and is performed by hot air heating, infrared irradiation, etc.

[0130] The dry film thickness of a painting composition, coating composition, ink composition, or adhesive composition used for coating may vary depending on the coating method or requirements, but can typically be about 10 to 50 μm.

[0131] The applied painting composition, coating composition, ink composition, or adhesive composition is subsequently dried by air drying by leaving it at room temperature, completely or incompletely, or by forced drying using hot air drying or an infrared heater, or in some cases, cured completely or incompletely by baking at a temperature of 120°C or lower to obtain an aqueous coating film. In particular, to form an aqueous coating film on a plastic material according to the present invention, it is preferable to obtain an aqueous film by drying by air drying or hot air drying at 40 to 120°C after coating so that the water content is about 25% by weight or less. Alternatively, to repair a multilayer coating film, it is preferable to obtain an aqueous film by drying by air blowing or hot air at 80°C or lower after coating.

[0132] The aqueous polyurethane resin composition of the present invention has excellent fluidity even when the composition has a high solid content, so the coating material using the composition has an excellent finished appearance. Furthermore, the adhesion of the coating film using the composition to a substrate, particularly to an electrodeposited coating film, is excellent, and excellent impact resistance is provided in both single-coating (monocoat) systems and multilayer coating systems. The aqueous polyurethane resin composition of the present invention is suitable as a raw material for an aqueous coating material for coating electrodeposited films.

[0133] Examples

[0134] The present invention will be described in more detail by the following specific examples.

[0135] PolyTHF2000 is a polytetramethylene ether glycol (OH value: 56 mg KOH / g; number average molecular weight: 2000 g / mol) available from BASF AG.

[0136] PolyTHF1000 is polytetramethylene ether glycol (OH value: 112 mg KOH / g; number average molecular weight: 1000 g / mol) available from BASF AG.

[0137] Desmophen 3600Z is a polypropylene oxide polyether polyol (OH value: 56 mg KOH / g; number average molecular weight: 2000 g / mol) available from Sumika Covestro Urethane Company, Limited.

[0138] PolyTHF650 is polytetramethylene ether glycol (OH value: 173 mg KOH / g; number average molecular weight: 650 g / mol) available from BASF AG.

[0139] Desmopene C2202 is a polycarbonate polyol (OH value: 56 mg KOH / g; number average molecular weight: 2000 g / mol) available from Sumika Covestro Urethane Company, Limited.

[0140] Desmopene 2028I is a polyester polyol (OH value: 56 mg KOH / g; number average molecular weight: 2000 g / mol) available from Sumika Covestro Urethane Company, Limited.

[0141] IPDI is isophorone diisocyanate (Desmodur I) available from Sumika Covestro Urethane Company, Limited.

[0142] HDI is hexamethylene diisocyanate (desmodur H), available from Sumika Covestro Urethane Company, Limited.

[0143] W is 4,4'-Diisocyanatodicyclohexylmethane (Desmodur W), which is available from Sumika Covestro Urethane Campani, Limited.

[0144] AAS is sodium 2-[(2-aminoethyl)amino]ethanesulfonate (Product No.: W01COBQV-7243) available from FUJIFILM Wako Pure Chemical Corporation.

[0145] DMPA is dimethylolpropionic acid (Bis-MPA) available from Tokyo Chemical Industry Co., Ltd.

[0146] AAP is sodium 3-[(2-aminoethyl)amino]propionate (Product No.: W01COBQV-3340) available from Fujifilm Wako Pure Chemical Corporation.

[0147] EDA is ethylenediamine (E0077) available from Tokyo Chemical Industry Company, Limited.

[0148] TMP is trimethylolpropane (T0480) available from Tokyo Chemical Industry Company, Limited.

[0149] DEOA is a diethanolamine (S0376) available from Tokyo Chemical Industry Company, Limited.

[0150] DMEA is N,N-dimethylethanolamine (D0649) available from Tokyo Chemical Industry Company, Limited.

[0151] [Method for measuring the general viscosity of water-based polyurethane resin compositions]

[0152] Measurements were performed using a Type B rotational viscometer at 25°C in accordance with JIS Z8803.

[0153] [Method for measuring viscosity when the solid content of an aqueous polyurethane resin composition is high (particularly, in the case where the polyurethane resin is contained in an amount of 65 weight%, the aqueous polyurethane resin composition has a viscosity of 500 Pa·s or more and 50,000 Pa·s or less.)]

[0154] For viscosity when the solid content is high, it is possible to measure the viscosity when the polyurethane resin is contained in an amount of 65 weight% or more by adjusting the amount of polyurethane resin contained by evaporating the aqueous medium in the aqueous polyurethane resin composition, for example, using an evaporator. Viscosity was measured at 25°C using a rheometer (e.g., AR-G2 manufactured by TA Instruments). The measurement conditions used were gap: 0.25 mm; geometry: conical plate type; diameter: 20 mm; cone angle: 0.042 radians; and rotation speed: 0.1 S⁻¹.

[0155] [Method for measuring the average molecular weight of the polyol compound of component (b)]

[0156] For the measurement of the average molecular weight of the polyol compound of component (b), the converted value obtained from a standard polystyrene calibration curve generated in advance using gel permeation chromatography (GPC) was recorded.

[0157] [Method for measuring the average molecular weight of polyurethane resin]

[0158] For the measurement of the average molecular weight of the polyurethane resin, the converted value obtained from a standard polystyrene calibration curve generated in advance using gel permeation chromatography (GPC) was recorded.

[0159] [How to Calculate the Acid Value of Polyurethane Resin]

[0160] The calculated value (mg KOH / g) is expressed as the number of mg of potassium hydroxide required to neutralize the carboxyl or sulfo groups present in the polyurethane resin. The ratio of the acid value of the carboxyl group to the total acid value is calculated by the following formula. The total acid value represents the total sum of the acid values ​​of the carboxyl group and the sulfo group.

[0161] Ratio of the acid value of the carboxyl group to the total acid value = AV [COOH] / (AV [COOH] + AV [SO3H] )

[0162] AV (총) : Total acid value in polyurethane resin (AV [COOH] + AV [SO3H] ).

[0163] AV [COOH] : Acid value derived from carboxyl groups in polyurethane resin

[0164] AV [SO3H] : Acid value derived from sulfonate groups in polyurethane resin

[0165] [Method for Measuring the Hydroxyl Value of Polyurethane Resin]

[0166] The hydroxyl value of the polyurethane resin was measured according to method B of JIS K 1557.

[0167] [Manufacturing Example 1: Water-based Polyurethane Resin Composition Example 1 (PUD No. 1)]

[0168] 4.19 parts by weight of polyTHF1000 (component b1), 19.59 parts by weight of polyTHF2000 (component b2), and 0.69 parts by weight of DMPA (component c) were filled into a reaction vessel equipped with a stirrer and a heating device, and heated to 70°C. Then, a mixture of 2.28 parts by weight of hexamethylene diisocyanate (component a1) and 3.02 parts by weight of isophorone diisocyanate (component a2) was added, and the mixture was stirred at 100 to 115°C until the mixture had a value slightly lower than the theoretical NCO value. The completed prepolymer was dissolved in acetone at 50°C to obtain a solution having a concentration of approximately 40%. Next, after performing a neutralization treatment by adding 0.46 parts by weight of DMEA, a solution of 0.28 parts by weight of ethylenediamine (component d1), 0.31 parts by weight of AAS (component c), and 5.0 parts by weight of deionized water was measured and added. The second stirring time was 15 minutes. Subsequently, dispersion was performed by adding 64.18 parts by weight of deionized water. Then, the solvent was removed by distillation under vacuum to obtain a dispersion having a solid content of 30.82 wt% and a viscosity of 2194 mPa·s (25°C, Type B viscometer, JIS Z8803).

[0169] [Manufacturing Examples 2 to 10 (Aqueous Polyurethane Resin Composition Examples 2 to 10 (PUD No. 2 to 10)) and Aqueous Polyurethane Resin Composition Comparative Examples 1 to 6 (PUD No. 11 to 16)]

[0170] Water-based polyurethane resin compositions No. 2 to 16 were obtained by the same process as the example of preparing water-based polyurethane resin composition (PUD No. 1) with the formulations presented in Table 1 below.

[0171] Table 1 presents the composition of water-based urethane resin compositions and viscosity values ​​at their respective concentrations (unless otherwise specified, values ​​in the table represent parts by weight).

[0172]

[0173]

[0174]

[0175] Setaqua B E270 is a polyester dispersion (OH value: 96 mg KOH / g; number average molecular weight: 1000 g / mol) available from Nuplex Industries Ltd.

[0176] Envirogem AD-01 is a surface conditioner available from Air Products Japan KK.

[0177] TEGO WET 775W is a pigment dispersant available from Evonik Japan Co., Ltd.

[0178] JR-806 is a titanium white available from Teyka Corporation.

[0179] [Pigment Dispersion Paste]

[0180] 11.30 parts by weight of a polyester dispersion Setaqua BE 270 was filled into a stainless steel cylindrical stirring tank equipped with a stirrer, and 25.30 parts by weight of ion-exchanged water were added while stirring. Next, 1.60 parts by weight of a 10% aqueous DMEA solution was added, and 1.60 parts by weight of a pigment dispersant Tego WET 775W was added while stirring. While stirring sufficiently, 1.30 parts by weight of a surface conditioner EnviroGem AD-01 was added. While stirring continued, 58.90 parts by weight of titanium oxide JR-806 were subsequently added, and the mixture was stirred for 15 minutes under sufficient stirring until homogeneous, thereby producing a pigment mill base. The mill base was applied to the pigment dispersion using a paint shaker to produce a pigment dispersion paste for an aqueous primer. This had a non-volatile content of 68.8% and a pigment concentration (PWC) of 85.0%.

[0181] The mixing ratio of the pigment dispersion paste is as shown in Table 2 below.

[0182] [Table 2]

[0183]

[0184] Simel 327 is a melamine resin available from Mitsui-Scitec Limited.

[0185] Bayhydrol A 2770 is an acrylic dispersion available from Sumika Covestro Urethane Company, Limited.

[0186] Byhidule BL 2781 is a blocked isocyanate available from Sumika Covestro Urethane Company, Limited.

[0187] [Preparation of Water-based Painting Composition No. 1]

[0188] 31.1 parts by weight of pigment dispersion paste prepared based on Table 2, 21.8 parts by weight of aqueous polyurethane resin composition No. 1 prepared in Preparation Example 1, 1.6 parts by weight of melamine resin Cimel 327, 19.4 parts by weight of acrylic dispersion Bihydrol A 2770, 21.8 parts by weight of blocked isocyanate Bihydrol BL 2781, and 4.3 parts by weight of deionized water were added and stirred sufficiently to obtain aqueous painting composition No. 1 having a solid content of 47% by weight. Afterwards, in order to obtain a viscosity that enables spray coating, the mixture was adjusted using a No. 4 Ford cup by adding deionized water so that a viscosity of about 40 seconds at 20°C was obtained.

[0189] [Creation of coated plates for evaluation]

[0190] An electrodeposited steel plate was coated with water-based painting composition No. 1 by air-spraying to obtain a dry film thickness of 35 to 40 μm, and baked at 140°C for 30 minutes to obtain a test plate for evaluation.

[0191] Preparation of water-based painting compositions No. 2 to 10 (Examples 2 to 10)

[0192] Water-based painting compositions No. 2 to 10 were prepared by performing the same work as the preparation example of water-based painting composition No. 1 with the formulations presented in Table 3 below, and coated plates for evaluation were produced using the same procedure.

[0193] Water-based painting compositions No. 11 to 16 (Comparative Examples 1 to 6)

[0194] Water-based painting compositions No. 11 to 16 were prepared by performing the same work as the preparation example of water-based painting composition No. 1 with the formulations presented in Table 3 below, and coated plates for evaluation were produced using the same procedure.

[0195] [Test Method]

[0196] [Method for measuring finished appearance]

[0197] A multilayer coating film was produced by vertical coating, and the gloss level of the coating film was measured according to the 60° specular gloss of JIS K-5400 7.6 (1990). A gloss value of 90 or higher indicates that the finished appearance is excellent and is marked with ⊙. Gloss values ​​of 80 or higher and less than 90 are marked with ○, gloss values ​​of 70 or higher and less than 80 are marked with △, and gloss values ​​less than 70 are marked with ×.

[0198] [Method for measuring impact resistance]

[0199] Chipping resistance: A test plate was mounted in the specimen holder of a chipping test device JA-400 (manufactured by Suga Test Instruments Co., Ltd, trademark; chipping test device); 50 g of granite crushed stone of size 7 grain was blown onto the coated surface by compressed air at -20°C with a pressure of 0.441 MPa (4.5 kgf / cm2); and the degree of damage on the coating film caused by the crushed stone was visually observed and evaluated.

[0200] Evaluation: Condition of coating film ○: The size of the damage is small enough to expose the electrodeposited film.

[0201] delete

[0202] △: The damage is small, but the base steel plate is exposed.

[0203] ×: The damage is very large, and the base steel plate is also significantly exposed.

[0204] [Method for Measuring Adhesion]

[0205] A cross-cut adhesion test was performed (100 squares of 1 x 1 mm size, tape peeling).

[0206] ○: Number of remaining squares 100 / 100

[0207] △: Number of remaining squares 95-99 / 100

[0208] ×: Number of remaining squares less than 95 / 100

[0209] The results of each evaluation test are summarized in Table 3 (unless otherwise specified, values ​​in the table represent parts by weight).

[0210]

[0211]

[0212]

[0213] From the results of Table 3, it can be seen that the aqueous painting composition of the present invention has an excellent finished appearance, excellent adhesion to the electrodeposited film, and excellent impact resistance.

[0214] Industrial applicability

[0215] Since the aqueous polyurethane resin composition of the present invention possesses excellent fluidity even when the composition has a high solid content, the coating material using said composition has an excellent finished appearance. Furthermore, the adhesion of the coating film using said composition to a substrate, particularly to an electrodeposited coating film, is excellent, and excellent impact resistance can be provided in both single-coating (monocoat) systems and multilayer coating systems. Therefore, the aqueous polyurethane resin composition of the present invention is suitable as a raw material for an aqueous coating material for coating electrodeposited films.

[0216] According to the present invention, it is possible to obtain an aqueous polyurethane resin composition having excellent adhesion to a finished appearance and an electrodeposited film, as well as impact resistance, which are essential characteristics that conflict with each other. The aqueous polyurethane resin composition of the present invention can be widely used as a raw material for painting compositions, coating compositions, ink compositions, adhesive compositions, etc.

Claims

Claim 1 An aqueous polyurethane resin composition comprising a polyurethane resin obtained from at least the following components (a) to (d): (a) at least two types of organic diisocyanate compounds that are distinct from each other; (b) a polyol compound; (c) an acid group-containing compound comprising at least two types of compounds, wherein the acid group-containing compound is a compound containing a carboxyl group as an acid group (carboxyl group-containing compound) and a compound containing a sulfo group as an acid group (sulfo group-containing compound); and (d) a chain extender selected from the group consisting of polyamine compounds, diamine compounds, polyol compounds and alkanolamine compounds, having a molecular weight of 400 or less, wherein when the polyurethane resin is contained in an amount of 65 wt%, the aqueous polyurethane resin composition has a viscosity of 500 Pa·s or more and 50,000 Pa·s or less, wherein the aqueous polyurethane resin composition has a viscosity change rate of 350% or less, wherein the viscosity change rate is calculated as follows: (Viscosity change rate (%)) = {(Viscosity when solid content is 80 wt%) - (Viscosity when solid content is 65 wt%)} / (Viscosity when solid content is 65 wt%) x 100, wherein viscosity is measured at 25°C, wherein component (a) is a cycloaliphatic selected from 4,4'-diisocyanatodicyclohexylmethane, isophorone diisocyanate and mixtures thereof It is a combination of a diisocyanate compound and an aliphatic diisocyanate compound, wherein the alicyclic diisocyanate compound is contained in a percentage of 80 mol% or less based on 100 mol% of the organic diisocyanate compound of component (a), wherein component (b) is a polytetramethylene glycol polyol, wherein the percentage of component (b) contained in the polyurethane resin is 60 weight% or more, wherein the acid group-containing compound of component (c) is a compound having two or more hydroxyl groups or amino groups, wherein the acid group-containing diol compound of component (c) is excluded from component (b), wherein the total weight of the carboxyl group-containing compound and the sulfo group-containing compound of component (c) is 0.A water-repellent polyurethane resin composition present in a polyurethane resin in an amount of 2 to 10 weight percent. Claim 2 A resin composition according to claim 1, wherein component (a) is a combination of a diisocyanate compound selected from 4,4'-diisocyanatodicyclohexylmethane or isophorone diisocyanate and an aliphatic diisocyanate compound, namely hexamethylene diisocyanate. Claim 3 An aqueous polyurethane resin composition according to claim 1 or 2, wherein component (b) has a number average molecular weight of greater than 400 g / mol and less than or equal to 6000 g / mol. Claim 4 An aqueous polyurethane resin composition according to claim 1 or 2, wherein the ratio of the acid value of the carboxyl group to the total acid value of component (c) is 0.20 to 0.

95. Claim 5 An aqueous polyurethane resin composition according to claim 1 or 2, wherein the acid value of the carboxyl group in the polyurethane resin is in the range of 4.5 to 30 mg KOH / g. Claim 6 An aqueous polyurethane resin composition according to claim 1 or 2, wherein the polyurethane resin is contained in a percentage of 20 to 65 weight percent. Claim 7 A painting composition or coating composition containing an aqueous polyurethane resin composition according to claim 1 or 2. Claim 8 delete Claim 9 delete Claim 10 delete Claim 11 delete Claim 12 delete Claim 13 delete Claim 14 delete

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