JP5511537B2 - Water-based polyurethane resin composition and paint using the composition - Google Patents

Description

  The present invention relates to an aqueous polyurethane resin composition, and in particular, an aqueous polyurethane resin composition having excellent chemical resistance such as water resistance, acid resistance, and alkali resistance, a paint containing the aqueous polyurethane resin composition, and the aqueous polyurethane resin. The present invention relates to a coated product obtained by applying a composition to the surface of a plate-like material.

Polyurethane resins are widely used as paints, adhesives, binders, coating agents, and the like because they have wear resistance, adhesiveness, non-tackiness, and rubber elasticity.
However, in recent years, there have been many reports on water-based polyurethane resin compositions from the viewpoint of safety against environmental pollution, occupational health, etc., but water-based polyurethane resin compositions are compared with solvent-based or solvent-free ones. There is a problem that the physical properties such as water resistance, chemical resistance, heat resistance, and tensile properties are inferior.
For example, a paint used for coating a surface-treated steel sheet is required to have chemical resistance such as water resistance, acid resistance, and alkali resistance, but the present water-based polyurethane resin composition is still indispensable. Nothing is known that can satisfy the physical properties.

  Further, a fluoropolymer obtained by reacting a reaction product of a polyfunctional isocyanate and a fluorinated alcohol with a polyoxyalkylene-containing substance has been proposed (Patent Document 1). In addition, the oil repellency is improved, but the adhesion to the steel sheet is not good, and therefore it is not suitable for use as a paint for steel sheet.

  In addition, as a water-based polyurethane resin having improved water resistance, chemical resistance, heat resistance, and the like, a water-based polyurethane resin containing a long-chain alkyl group in the side chain is disclosed. However, when this water-based polyurethane resin is urethanized using a short branched diol as the main chain (Patent Documents 2 to 4), urethane bonds having high cohesive energy are close to each other, so that the generated urethane prepolymer aggregates. In addition, since the viscosity increases, water dispersion becomes difficult.

When a branched diol having a long main chain is used (Patent Document 5), the long-chain alkylene group incorporated in the urethane main chain increases the hydrophobicity and decreases the water dispersibility.
Furthermore, although an aqueous dispersion type polyurethane composition comprising an isocyanurate compound having a long-chain alkyl group, a polyol and water is disclosed (Patent Documents 6 and 7), the water resistance and chemical resistance are not sufficient. .

Japanese National Patent Publication No. 11-511814 JP 2000-007909 A JP 2005-510600 Gazette JP-A-2005-068228 Special table 2004-502000 gazette WO06 / 038466 JP 2009-203316 A

As a result of intensive studies to solve the above-described conventional drawbacks, the present inventors have determined that a urethane prepolymer in which a certain amount of a long-chain alkylene diol compound is incorporated in a urethane resin skeleton is a specific alkylene polyamine compound. A water-based urethane resin composition having excellent chemical resistance such as water resistance, acid resistance, alkali resistance, and adhesion to a base material is obtained by adding a certain amount of an amine compound having an essential component as a chain extender. The present invention has been found.
Accordingly, an object of the present invention is to provide a water-based urethane resin composition that is excellent in water resistance, chemical resistance (acid resistance, alkali resistance), adhesion to a base material, etc. The object is to provide a plate-like coated product obtained by applying a urethane resin.

但し、式（１）中のＲ^１は炭素原子数１〜６のアルキレン基であり、ｎは２〜４の数である。 That is, the present invention is an aqueous polyurethane resin composition containing an aqueous polyurethane resin obtained by reacting a chain extender with a urethane prepolymer obtained by reacting a polyisocyanate and a polyol. 5 to 35 mass% is a long chain alkylene diol compound (a) having 10 to 32 carbon atoms, and the chain extender is a polyalkylene polyamine compound (b) represented by the following general formula (1): And the content of the component (b) is such that the amino group equivalent of the polyalkylene polyamine compound is 0.2 to 1.0 when the equivalent of the amino group in the total chain extender is 1. In addition to the amount of the chain extender, the content of the total chain extender is such that the equivalent of the amino group of the total chain extender is 0.5 to 0.9 with respect to 1 equivalent of the isocyanate group of the urethane prepolymer. An aqueous polyurethane resin composition, a paint containing the aqueous polyurethane resin composition, and a coated product obtained by applying the paint to a plate-like material It is.

However, ^{R 1} in the formula (1) is an alkylene group having 1 to 6 carbon atoms, n is the number of 2-4.

In the water-based polyurethane resin composition, the polyisocyanate is preferably at least one diisocyanate selected from the group consisting of aromatic diisocyanates, alicyclic diisocyanates, and aliphatic diisocyanates. In 1), R ¹ is preferably an ethylene (—CH ₂ CH ₂ —) group and n is preferably 2 or 3.
Moreover, the water-based polyurethane resin composition of the present invention is useful for coating a surface-treated steel sheet.

  By coating the water-based polyurethane resin composition of the present invention particularly on a surface-treated steel sheet, a coated product having a coating film excellent in water resistance and chemical resistance can be obtained.

The aqueous polyurethane resin contained in the aqueous polyurethane resin composition of the present invention is obtained by reacting a chain extender with a urethane prepolymer obtained by reacting a polyisocyanate and a polyol.
The polyisocyanate used for the synthesis of the urethane prepolymer is not particularly limited, and a diisocyanate compound and a polyisocyanate having three or more isocyanate groups can be used.

  Examples of the diisocyanate compound include tolylene diisocyanate, diphenylmethane-4,4′-diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate, 1,5-naphthylene diisocyanate, 3,3′-dimethyldiphenyl-4,4′-diisocyanate. , Aromatic diisocyanates such as dianisidine diisocyanate and tetramethylxylylene diisocyanate; cycloaliphatic such as isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, trans and / or cis-1,4-cyclohexane diisocyanate, norbornene diisocyanate Diisocyanates; 1,6-hexamethylene diisocyanate, 2,2,4 and / or (2,4,4) -trimethylhexamethylene dii Cyanate, aliphatic diisocyanates such as lysine diisocyanate; and mixtures thereof.

  Moreover, as polyisocyanate which has 3 or more isocyanate groups, it is trifunctional or more trifunctional such as triphenylmethane triisocyanate, 1-methylbenzole-2,4,6-triisocyanate, dimethyltriphenylmethane tetraisocyanate, and mixtures thereof. Isocyanates, modified products of these tri- or higher functional isocyanates such as carbodiimide modification, isocyanurate modification, biuret modification, etc., blocked isocyanates blocked with various blocking agents, isocyanurate trimers and biuret trimers of the aforementioned diisocyanates Etc.

Among these, adhesion resistance, weather resistance, and the like excellent in water-based polyurethane resin composition strength can be obtained, as the polyisocyanate, aromatic diisocyanates, the group consisting of cycloaliphatic diisocyanates and aliphatic diisocyanates It is preferable to use at least one diisocyanate selected from the above, and it is particularly preferable to use 1,6-hexamethylene diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, or isophorone diisocyanate as the diisocyanate compound.

The polyol used for the production of the aqueous polyurethane resin composition of the present invention contains a long-chain alkylene diol compound (a) having 10 to 32 carbon atoms as an essential component.
The content of the component (a) needs to be 5 to 35% by mass of the polyol component, preferably 10 to 30% by mass, and more preferably 15 to 25%. If it is less than 5% by mass, the water-based polyurethane resin composition has low water resistance and chemical resistance. If it exceeds 35% by mass, the dispersibility of the urethane prepolymer in water decreases, and the production of the water-based polyurethane resin is reduced. It becomes difficult.

  Examples of the long chain alkylenediol compound having 10 to 32 carbon atoms used as the component (a) include decanediol, undecanediol, dodecanediol, tridecanediol, tetradecanediol, pentadecanediol, hexadecanediol, and heptadecanediol. , Octadecanediol, nonadecanediol, icosanediol, heicosonediol, docosanediol, tricosanediol, tetracosanediol, pentacosanediol, hexacosanediol, heptacosandiol, octacosanediol, nonacosandiol, tria Examples thereof include linear or branched diols such as Contandiol, Hentriacontanediol, and Dotriacontanediol.

  Among these, since a water-based polyurethane resin composition excellent in water resistance and chemical resistance is obtained, the component (a) is preferably a long-chain alkylene diol having 12 to 18 carbon atoms, and 1,12- Particularly preferred is dodecanediol or 1,12-octadecanediol.

  The polyol other than the component (a) is not particularly limited. For example, low-molecular polyols having a number average molecular weight of less than 200, polyether polyols, polyester polyols, polyester polycarbonate polyols, crystalline or non-crystalline. And polycarbonate polyols.

  Examples of the low molecular polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, diethylene glycol, triethylene glycol, 2-butyl-2- Ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1 , 5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanedio Aliphatic diols such as cyclohexanedimethanol, cyclohexanediol, etc .; trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin, polyglycerin, pentaerythritol, dipentaerythritol, tetramethylolpropane, etc. A trihydric or more polyol is mentioned.

Examples of the polyether polyols include 1,2-propanediol, 1,3-propanediol; trimethylolpropane, glycerin, polyglycerin, pentaerythritol, and other low molecular polyols, as well as bisphenol A and ethylenediamine. Examples include ethylene oxide and / or propylene oxide adducts to amine compounds and the like; polytetramethylene ether glycol and the like.
The number average molecular weight of the polyether polyols used in the production of the aqueous polyurethane resin composition of the present invention is preferably 300 to 5,000, particularly preferably 1,000 to 3,000.

  Examples of the polyester polyols include polyols such as the above-described low molecular weight polyols and polyvalent carboxylic acids in an amount less than the stoichiometric amount, or ester-forming derivatives thereof such as esters, anhydrides, and carboxylic acid halides. Examples thereof include polyester polyols obtained by direct esterification reaction or transesterification reaction; and polyester polyols obtained by direct esterification reaction of the polyol and hydroxycarboxylic acid obtained by hydrolytic ring-opening reaction thereof.

  Examples of the polyvalent carboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, 2-methylsuccinic acid, and 2-methyladipine. Fats such as acid, 3-methyladipic acid, 3-methylpentanedioic acid, 2-methyloctanedioic acid, 3,8-dimethyldecanedioic acid, 3,7-dimethyldecanedioic acid, hydrogenated dimer acid, dimer acid Aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; tricarboxylic acids such as trimellitic acid, trimesic acid, and castor oil fatty acid trimer A tetravalent or higher carboxylic acid such as pyromellitic acid.

The ester forming derivative of the polyvalent carboxylic acids, polyvalent carboxylic acids, anhydrides described above, or chlorides, carboxylic acid halides bromide and the like; methyl ester of the polyvalent carboxylic acid, ethyl ester, propyl ester, isopropyl Examples include lower aliphatic esters such as esters, butyl esters, isobutyl esters, and amyl esters.

  Examples of the lactones include lactones such as γ-caprolactone, δ-caprolactone, ε-caprolactone, dimethyl-ε-caprolactone, δ-valerolactone, γ-valerolactone, and γ-butyrolactone.

  Examples of polyester polycarbonate polyols include reaction products obtained by reacting a reaction product of polyester glycol such as polycaprolactone polyol and alkylene carbonate with alkylene carbonate, and a reaction product of ethylene carbonate and polyhydric alcohol with an organic dicarboxylic acid. Is mentioned.

As crystalline or non-crystalline polycarbonate polyols,
Diols such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, polypropylene glycol, and / or polytetramethylene glycol, phosgene, diallyl carbonate (eg diphenyl carbonate) or cyclic carbonate (For example, a reaction product with propylene carbonate).

  The number average molecular weight of the polyester polyols used in the production of the aqueous polyurethane resin composition of the present invention is preferably 300 to 5,000, particularly preferably 500 to 3,000.

The chain extender contains the polyalkylene polyamine compound (b) represented by the general formula (1) as an essential component. R ^{1 in the} general formula (1) is an alkylene group having 1 to 6 carbon atoms, and is preferably an alkylene group having 2 or 3 carbon atoms, particularly an ethylene group, from the viewpoint of water resistance and chemical resistance. It is preferable that
Moreover, n is a number from 2 to 4, and n is preferably 2 or 3 from the viewpoint of water resistance and chemical resistance.

  Examples of the polyalkylpolyamine compound of component (b) include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and dipropylenetriamine. Among these, from the viewpoint of water resistance and chemical resistance, it is preferable to use diethylenetriamine or triethylenetetramine, and it is particularly preferable to use diethylenetriamine.

The compounding amount of the polyalkylene polyamine compound of the component (b) in the chain extender is such that the amino group (-) of the polyalkylene polyamine compound (b) is 1 when the equivalent of the amino group in the total chain extender is 1. NH ₂ or —NH—) is an amount such that the equivalent is 0.2 to 1.0, preferably 0.3 to 0.8, and preferably 0.4 to 0.6. More preferably.
When the equivalent of the amino group of the component (b) is less than 0.2, water resistance and chemical resistance are insufficient.

When producing a water-based urethane resin, the equivalent ratio of the amino group of the total chain extender to the equivalent of the isocyanate group of the urethane prepolymer before the chain extension reaction (-NH _X / -NCO, where X is 1 or 2) is too small. Then, the number average molecular weight of the obtained water-based polyurethane resin becomes relatively low, and not only the coating properties such as coating strength are inferior, but also water resistance and chemical resistance tend to be inferior.
On the other hand, the terminal isocyanate group of the urethane prepolymer in water decreases because it reacts with water and bonds with other isocyanate groups. Therefore, when the equivalent of the amino group of the total chain extender is equal to the equivalent of the isocyanate group, some of the chain extender monomer remains unreacted to whiten the coating or adhere to the substrate. In some cases, the physical properties of the coating film may be reduced.
From such a viewpoint, the blending amount of the total chain extender including the component (b) is equivalent to the equivalent ratio of the amino group of the total chain extender to 1 equivalent of the isocyanate group of the urethane prepolymer before the chain extension reaction (- NH _X / -NCO, wherein X is an amount such that 1 or 2) is 0.5 to 0.9, and preferably 0.6 to 0.8.

In the present invention, in addition to the polyalkylene polyamine (b), one or more other extenders are combined in a range that satisfies the requirements for the blending amount of the component (b) and the blending amount of the extender described above. Can be used.
The chain extender other than the component (b) is not particularly limited, and is appropriately selected from commonly used chain extenders such as low molecular weight polyol compounds and low molecular polyamine compounds having a number average molecular weight of less than 200. Can be used.

  Examples of the low molecular weight polyol compound include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, diethylene glycol, triethylene glycol, and 2-butyl-2-ethyl. -1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1, 5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanedio Aliphatic diols such as cyclohexane dimethanol, cyclohexanediol, etc .; trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin, polyglycerin, pentaerythritol, dipentaerythritol, tetramethylolpropane, etc. And a trivalent or higher polyol.

  Examples of the low-molecular polyamine compound include low-molecular diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, tolylenediamine, piperazine, and 2-methylpiperazine, and polyether diamines such as polyoxypropylenediamine and polyoxyethylenediamine. , Mensenediamine, isophoronediamine, norbornenediamine, aminoethyleminoethanol, bis (4-amino-3-methyldicyclohexyl) methane, diaminodicyclohexylmethane, bis (aminomethyl) cyclohexane, 3,9-bis (3- Aminopropyl) -2,4,8,10-tetraoxaspiro (5,5) undecane and other alicyclic diamines, m-xylenediamine, α- (m / paminophenyl) ethylamine, m-phenyle Aromatic diamines such as diamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiethyldimethyldiphenylmethane, diaminodiethyldiphenylmethane, dimethylthiotoluenediamine, diethyltoluenediamine, α, α'-bis (4-aminophenyl) -p-diisopropylbenzene Polyamines such as succinic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, phthalic acid dihydrazide, hydrated hydrazine, 1,6-hexamethylenebis (N, N-dimethylsemicarbazide), 1,1,1 ', 1'- Examples include hydrazines such as tetramethyl-4,4 ′-(methylene-di-para-phenylene) disemicarbazide and water.

Moreover, in the synthesis | combination of a urethane prepolymer, you may make polyisocyanate and a polyol react in an inert solvent as needed, and add an ionic group introducing agent with a polyisocyanate and a polyol as needed. Further, it may be a terminal isocyanate prepolymer having an ionic group introduced therein.
Further, if necessary, the prepolymer may be dispersed in water containing an ionic group neutralizing agent and / or an emulsifier, and then a chain extender may be added to cause a high molecular weight reaction.

  Suitable examples of the inert solvent include acetone, methyl ethyl ketone, dioxane, tetrahydrofuran, N-methyl-2-pyrrolidone and the like. These solvents are usually used in an amount of 3 to 100 parts by mass with respect to 100 parts by mass of the total amount of the raw materials used for producing the prepolymer. When using a solvent having a boiling point of 100 ° C. or lower as these solvents, it is preferable to synthesize an aqueous polyurethane resin and then remove the solvent by distillation under reduced pressure or the like.

Examples of the ionic group introducing agent include those that introduce an anionic group and those that introduce a cationic group. Examples of those that introduce an anionic group include polyols containing carboxyl groups such as dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolbutyric acid, dimethylolvaleric acid, 1,4-butanediol-2-sulfonic acid, etc. These polyols containing sulfonic acid groups of
Moreover, as what introduce | transduces a cationic group, N-alkyl-N, such as N, N-dialkyl alkanolamines, N-methyl-N, N-diethanolamine, N-butyl-N, N-diethanolamine, for example, N-dialkanolamines and trialkanolamines can be mentioned.

The mixing ratio of the ionic group introducing agent, polyisocyanate and polyol is such that the isocyanate group equivalent of the polyisocyanate is 0.5 to 5 with respect to 1 equivalent of the hydroxyl group of the polyol at the stage of reacting them. It is preferable that the blending is 0.9 to 3.0, particularly 1.0 to 2.0.
Moreover, when using an ionic group introducing agent, it is blended so that the isocyanate group equivalent of the polyisocyanate becomes the above-mentioned equivalent with respect to 1 equivalent of the total amount of the isocyanate reactive group of the ionic group introducing agent and the hydroxyl group of the polyol. To do.

  The amount of the ionic group introducing agent used depends on the type of polyol and polyisocyanate used and the use of an emulsifier, but in a self-emulsifying system using an ionic group introducing agent, an aqueous polyurethane resin is usually used. It is 0.5-50 mass parts with respect to 100 mass parts of all the reaction components to comprise, and it is preferable that it is 1-30 mass parts. If it is less than 0.5 parts by mass, the storage stability is poor, and if it exceeds 50 parts by mass, the water dispersibility of the urethane prepolymer and the physical properties of the urethane coating may be adversely affected.

  Examples of the ionic group neutralizer include an anionic group neutralizer, trialkylamines such as trimethylamine, triethylamine, and tributylamine, N, N-dimethylethanolamine, N, N-dimethylpropanolamine, N, Trialkanols such as N-dipropylethanolamine, N, N-dialkylalkanolamines such as 1-dimethylamino-2-methyl-2-propanol, N-alkyl-N, N-dialkanolamines, and triethanolamine Tertiary amine compounds such as amines; basic compounds such as ammonia, trimethylammonium hydroxide, sodium hydroxide, potassium hydroxide, and lithium hydroxide

  Examples of the neutralizing agent for the cationic group include organic carboxylic acids such as formic acid, acetic acid, lactic acid, succinic acid, glutaric acid and citric acid, organic sulfonic acids such as paratoluenesulfonic acid and alkyl sulfonate, hydrochloric acid and phosphoric acid. In addition to inorganic acids such as nitric acid and sulfonic acid, and epoxy compounds such as epihalohydrin, quaternizing agents such as dialkyl sulfuric acid and alkyl halides may be mentioned.

The amount of these neutralizing agents used is preferably 0.5 to 2.0 equivalents, more preferably 0.8 to 1.5 equivalents, relative to 1 equivalent of the ionic group.
If the amount of the neutralizing agent used is excessive or insufficient, physical properties such as water resistance, strength, and elongation of the coating film obtained from the water-based polyurethane resin may be lowered.

  The emulsifier is not particularly limited, and anionic surfactants, nonionic surfactants, primary amine salts, secondary amine salts, tertiary amine salts, quaternary amine salts, pyridinium salts, and other cationic systems Known surfactants and amphoteric surfactants such as betaine type, sulfate ester type and sulfonic acid type can be used.

  Examples of the anionic surfactant include sodium sulfates such as sodium dodecyl sulfate, potassium dodecyl sulfate, and ammonium dodecyl sulfate; polyoxyethylene ether sulfates such as sodium dodecyl polyglycol ether sulfate and ammonium polyoxyethylene alkyl ether sulfate; sodium Sulfolicinolate; Alkyl sulfonates such as alkali metal salts of sulfonated paraffins and ammonium salts of sulfonated paraffins; Fatty acid salts such as sodium laurate, triethanolamine oleate and tolethanolamine abiates; Alkyl aryl sulfonates such as alkali metal sulfate High alkyl naphthalene sulfonate; naphthalene sulfonic acid formalin condensate; dialkyl sulfosuccinate; polyoxyethylene alkyl sulfate salt; polyoxyethylene alkyl aryl sulfate salt; polyoxyethylene ether phosphate; polyoxyethylene alkyl ether acetate N-acyl amino acid salt; N-acyl methyl taurine salt and the like.

  Examples of the nonionic surfactant include fatty acid partial esters of polyhydric alcohols such as sorbitan monolaurate and sorbitan monooleate; polyoxyethylene glycol fatty acid esters; polyglycerin fatty acid esters; and alcohols having 1 to 18 carbon atoms. Examples include ethylene oxide and / or propylene oxide adduct; ethylene oxide and / or propylene oxide adduct of alkylphenol; ethylene glycol and / or propylene oxide adduct of alkylene glycol and / or alkylene diamine. Examples of the alcohol having 1 to 18 carbon atoms constituting these nonionic surfactants include methanol, ethanol, propanol, 2-propanol, butanol, 2-butanol, tertiary butanol, amyl alcohol, isoamyl alcohol, and tertiary amyl alcohol. Hexanol, octanol, decane alcohol, lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol and the like.

  Examples of the alkylphenol include phenol, methylphenol, 2,4-di-tert-butylphenol, 2,5-di-tert-butylphenol, 3,5-di-tert-butylphenol, 4- (1,3-tetramethylbutyl) phenol, 4-isooctylphenol, 4-nonylphenol, 4-tert-octylphenol, 4-dodecylphenol, 2- (3,5-dimethylheptyl) phenol, 4- (3,5-dimethylheptyl) phenol, naphthol, bisphenol A, bisphenol F etc. are mentioned.

  Examples of the alkylene glycol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1 , 4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, etc. Examples of the alkylene diamine include those in which the alcoholic hydroxyl group of these alkylene glycols is substituted with an amino group. Further, the ethylene oxide and propylene oxide adducts may be random adducts or block adducts.

  Cationic surfactants include tetraalkylammonium compounds such as lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, distearyldimethylammonium chloride, didecyldimethylammonium chloride, laurylbenzyldimethylammonium chloride; pyridines such as alkylpyridinium bromide; Examples thereof include imidazoles such as imidazolinium laurate.

Amphoteric surfactants include coconut oil fatty acid amidopropyl dimethyl acetate betaine, lauryl dimethyl amino acid betaine,
2-alkyl-N-carboxymethyl-N-hydroxymethylimidazolinium betaine, laurylhydroxysulfobetaine, lauroylamidoethylhydroxyethylcarboxymethylbetaine, betaine type such as metal salt of hydroxypropyl phosphate, β-laurylaminopropionic acid Amino acid type such as metal salt, sulfate type and sulfonic acid type.

  The amount of the emulsifier is not particularly limited, but from the viewpoint of physical properties such as water resistance, strength, elongation and the like of a coating film obtained by applying an aqueous polyurethane resin composition, to 100 parts by mass of the polyurethane resin. It is preferable that it is 1-30 mass parts, and it is more preferable that it is especially 5-20 mass parts. If the amount is less than 1 part by mass, sufficient dispersibility may not be obtained. If the amount exceeds 30 parts by mass, the physical properties of the coating film and the like may be deteriorated.

In addition, in the aqueous polyurethane resin composition of the present invention, if necessary, before adding an extender to the urethane prepolymer, a usual crosslinking agent is further blended in order to give the polyurethane molecule a crosslinked structure. Also good.
Suitable crosslinking agents for the aqueous polyurethane resin composition of the present invention include melamine, monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, hexamethylol melamine, methylated methylol melamine, butylated methylol. Examples include melamine and melamine resin. In the present invention, it is preferable to select and use an inexpensive melamine excellent in dispersibility in polyurethane from among these.

  The aqueous polyurethane resin composition of the present invention can be used after appropriately diluted, and the solid content concentration is not particularly limited. From the viewpoints of dispersibility, coating film, and operability for obtaining a molded body, the solid content is preferably 1 to 65% by mass, and more preferably 5 to 40% by mass.

  Moreover, you may add the various additives normally used to the water-based polyurethane resin composition of this invention as needed. Examples of such additives include pigments; dyes; film-forming aids; curing agents; external cross-linking agents; viscosity modifiers; leveling agents; antifoaming agents; anti-gelling agents; Light stabilizers such as hindered amines; antioxidants such as phenolic compounds, phosphorus compounds and sulfur compounds; UV absorbers comprising triazine compounds, benzoate compounds and 2- (2-hydroxyphenyl) benzotriazole compounds Radical scavengers, heat resistance imparting agents, inorganic and organic fillers, plasticizers, lubricants, antistatic agents, reinforcing agents, catalysts, thixotropic agents, antibacterial agents, antifungal agents, anticorrosive agents, and rust inhibitors Is mentioned.

  Further, when the aqueous polyurethane resin composition of the present invention is used for a paint or a coating agent, a silane coupling agent, colloidal silica, tetraalkoxysilane and its condensation polymer that give particularly strong adhesion to the substrate, Chelating agents and epoxy compounds may be used.

  Among the above-mentioned various additives, when the aqueous polyurethane resin composition of the present invention is used for a coating film or coating exposed outdoors, a hindered amine light stabilizer, an ultraviolet absorber, and an antioxidant (phosphorus, phenol) Or sulfur-based antioxidants).

  Examples of the hindered amine light stabilizer include 2,2,6,6-tetramethyl-4-piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, 2,2, 6,6-tetramethyl-4-piperidylbenzoate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate Bis (1-octoxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, 1,2,2,6,6-pentamethyl-4-piperidylmethyl methacrylate, 2,2,6,6- Tetramethyl-4-piperidylmethyl methacrylate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracar Xylate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, bis (2,2,6,6-tetramethyl-4-piperidyl) ) .Bis (tridecyl) -1,2,3,4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) .bis (tridecyl) -1,2,3 4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) -2-butyl-2- (3,5-ditert-butyl-4-hydroxybenzyl) malonate, 1- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinol / diethyl succinate polycondensate, 1,6-bis (2,2,6,6-tetramethyl-4- Piperidi Amino) hexane / dibromoethane polycondensate, 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-morpholino-s-triazine polycondensate 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-tert-octylamino-s-triazine polycondensate, 1,5,8 , 12-tetrakis [2,4-bis (N-butyl-N- (2,2,6,6-tetramethyl-4-piperidyl) amino) -s-triazin-6-yl] -1,5,8 , 12-tetraazadodecane, 1,5,8,12-tetrakis [2,4-bis (N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino) -s -Triazin-6-yl] -1,5,8,1 2-tetraazadodecane, 1,6,11-tris [2,4-bis (N-butyl-N- (2,2,6,6-tetramethyl-4-piperidyl) amino) -s-triazine-6 -Ylamino] undecane, 1,6,11-tris [2,4-bis (N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino) -s-triazine-6 -Ylamino] undecane, 3,9-bis [1,1-dimethyl-2- [tris (2,2,6,6-tetramethyl-4-piperidyloxycarbonyloxy) butylcarbonyloxy] ethyl] -2,4 , 8,10-tetraoxaspiro [5.5] undecane, 3,9-bis [1,1-dimethyl-2- [tris (1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyloxy] ) Butyl Ruboniruokishi] ethyl] -2,4,8,10-spiro [5.5] undecane.

  Examples of the ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5′-methylenebis (2-hydroxy-4-methoxybenzophenone). 2-hydroxybenzophenones such as 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole, 2- (2-hydroxy-3, 5-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3,5 -Dicumylphenyl) benzotriazole, 2,2'-methylenebis (4-th Octyl-6-benzotriazolylphenol), 2- (2-hydroxy-3-tert-butyl-5-carboxyphenyl) benzotriazole polyethylene glycol ester, 2- [2-hydroxy-3- (2-acryloyloxy) Ethyl) -5-methylphenyl] benzotriazole, 2- [2-hydroxy-3- (2-methacryloyloxyethyl) -5-tert-butylphenyl] benzotriazole, 2- [2-hydroxy-3- (2- Methacryloyloxyethyl) -5-tert-octylphenyl] benzotriazole, 2- [2-hydroxy-3- (2-methacryloyloxyethyl) -5-tert-butylphenyl] -5-chlorobenzotriazole, 2- [2 -Hydroxy-5- (2-methacryloyloxyethyl) phenyl] benzene Zotriazole, 2- [2-hydroxy-3-tert-butyl-5- (2-methacryloyloxyethyl) phenyl] benzotriazole, 2- [2-hydroxy-3-tert-amyl-5- (2-methacryloyloxy) Ethyl) phenyl] benzotriazole, 2- [2-hydroxy-3-tert-butyl-5- (3-methacryloyloxypropyl) phenyl] -5-chlorobenzotriazole, 2- [2-hydroxy-4- (2- Methacryloyloxymethyl) phenyl] benzotriazole, 2- [2-hydroxy-4- (3-methacryloyloxy-2-hydroxypropyl) phenyl] benzotriazole, 2- [2-hydroxy-4- (3-methacryloyloxypropyl) 2- (2-hydroxypheny) such as phenyl] benzotriazole B) benzotriazoles; 2- (2-hydroxy-4-methoxyphenyl) -4,6-diphenyl-1,3,5-triazine, 2- (2-hydroxy-4-hexyloxyphenyl) -4,6 -Diphenyl-1,3,5-triazine, 2- (2-hydroxy-4-octoxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [ 2-hydroxy-4- (3-C12-C13 mixed alkoxy-2-hydroxypropoxy) phenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [2- Hydroxy-4- (2-acryloyloxyethoxy) phenyl] -4,6-bis (4-methylphenyl) -1,3,5-triazine, 2- (2,4-dihydroxy-3-allylpheny ) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-hexyloxyphenyl) -1,3 2- (2-hydroxyphenyl) -4,6-diaryl-1,3,5-triazines such as 1,5-triazine; phenyl salicylate, resorcinol monobenzoate, 2,4-di-tert-butylphenyl-3,5 Di-tert-butyl-4-hydroxybenzoate, octyl (3,5-di-tert-butyl-4-hydroxy) benzoate, dodecyl (3,5-di-tert-butyl-4-hydroxy) benzoate, tetradecyl (3,5 -Di-tert-butyl-4-hydroxy) benzoate, hexadecyl (3,5-di-tert-butyl-4-hydroxy) benzoate, octadecyl (3,5-di) Benzoates such as 3 butyl-4-hydroxy) benzoate, behenyl (3,5-ditert-butyl-4-hydroxy) benzoate; 2-ethyl-2′-ethoxyoxanilide, 2-ethoxy-4′-dodecyl Substituted oxanilides such as oxanilide; Cyanoacrylates such as ethyl-α-cyano-β, β-diphenyl acrylate, methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate; various metals Examples include salts or metal chelates, particularly nickel or chromium salts or chelates.

  Examples of the phosphorus antioxidant include triphenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tris (2,5-di-tert-butylphenyl) phosphite, and tris (nonylphenyl). ) Phosphite, tris (dinonylphenyl) phosphite, tris (mono, dimixed nonylphenyl) phosphite, diphenyl acid phosphite, 2,2′-methylenebis (4,6-ditertiarybutylphenyl) octyl phosphite , Diphenyldecyl phosphite, diphenyloctyl phosphite, di (nonylphenyl) pentaerythritol diphosphite, phenyl diisodecyl phosphite, tributyl phosphite, tris (2-ethylhexyl) phosphite, tridecyl phosphite, trilauryl phosphite , Dibutyl acid phosphite, dilauryl acid phosphite, trilauryl trithiophosphite, bis (neopentyl glycol) 1,4-cyclohexanedimethyl diphosphite, bis (2,4-ditert-butylphenyl) pentaerythritol di Phosphite, bis (2,5-ditertiarybutylphenyl) pentaerythritol diphosphite, bis (2,6-ditertiarybutyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4-dicine (Milphenyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tetra (C12-15 mixed alkyl) -4,4′-isopropylidene diphenylphosphite, bis [2,2′-methylenebis (4,6- Diamylphenyl)] Isopropylidene diphenyl phosphite, tetratridecyl 4,4'-butylidenebis (2-tert-butyl-5-methylphenol) diphosphite, hexa (tridecyl) 1,1,3-tris (2-methyl-5-tert 3-butyl-4-hydroxyphenyl) butane triphosphite, tetrakis (2,4-di-tert-butylphenyl) biphenylene diphosphonite, tris (2-[(2,4,7,9-tetrakis-tert-butyldibenzo [ d, f] [1,3,2] dioxaphosphin-6-yl) oxy] ethyl) amine, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, tris (2-[(2,4,8,10-tetrakis tert-butyldibenzo [d, f] [1,3,2] dioxaphospin-6-yl ) Oxy] ethyl) amine, 2- (1,1-dimethylethyl) -6-methyl-4- [3-[[2,4,8,10-trakis (1,1-dimethylethyl) dibenzo [d, f] [1,3,2] dioxaphosphepin-6-yl] oxy] propyl] phenol 2-butyl-2-ethylpropanediol, 2,4,6-tritert-butylphenol monophosphite, etc. It is done.

  Examples of the phenol-based antioxidant include 2,6-ditertiarybutyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-ditertiarybutyl-4- Hydroxyphenyl) propionate, distearyl (3,5-ditertiarybutyl-4-hydroxybenzyl) phosphonate, tridecyl 3,5-ditertiarybutyl-4-hydroxybenzylthioacetate, thiodiethylenebis [(3,5 -Di-tert-butyl-4-hydroxyphenyl) propionate], 4,4'-thiobis (6-tert-butyl-m-cresol), 2-octylthio-4,6-di (3,5-di-tert-butyl) -4-hydroxyphenoxy) -s-triazine, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), bis [3,3- (4-hydroxy-3-tert-butylphenyl) butyric acid] glycol ester, 4,4′-butylidenebis (2,6-ditert-butylphenol), 4,4′-butylidenebis (6-tert-butyl- 3-methylphenol), 2,2′-ethylidenebis (4,6-di-tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, bis [2-tert-butyl-4-methyl-6- (2-hydroxy-3-tert-butyl-5-methylbenzyl) phenyl] terephthalate, 1,3,5-tris (2,6-dimethyl-3-hydroxy -4-tert-butylbenzyl) isocyanurate, 1,3,5-tris (3,5-ditert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tri (3,5-di-tert-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene, 1,3,5-tris [(3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy Ethyl] isocyanurate, tetrakis [methylene-3- (3 ′, 5′-ditert-butyl-4′-hydroxyphenyl) propionate] methane, 2-tert-butyl-4-methyl-6- (2-acroyl) Oxy-3-tert-butyl-5-methylbenzyl) phenol, 3,9-bis [2- (3-tert-butyl-4-hydroxy-5-methylhydrocinnamoyloxy) -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, triethylene glycol bis [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) pro Onato], tocopherol and the like.

  Examples of the sulfur-based antioxidant include dialkylthiodipropionates such as dilauryl, dimyristyl, myristyl stearyl, and distearyl esters of thiodipropionic acid, and pentaerythritol tetra (β-dodecyl mercaptopropionate). Examples include β-alkyl mercaptopropionic esters of polyols.

  Each usage-amount of the said hindered amine light stabilizer, a ultraviolet absorber, and antioxidant shall be 0.001-10 mass parts with respect to 100 mass parts of solid content of the water-based polyurethane resin composition of this invention. Particularly preferred is 0.01 to 5 parts by mass. If the amount is less than 0.001 part by mass, a sufficient addition effect may not be obtained. If the amount is more than 10 parts by mass, the dispersibility and the coating properties may be affected.

  As a method of adding these hindered amine light stabilizers, ultraviolet absorbers and antioxidants, a method of adding to a polyol, a method of adding to a prepolymer, a method of adding to a water phase at the time of water dispersion, and adding after water dispersion Any method may be used, but from the viewpoint of easy operation, a method of adding to the polyol component and a method of adding to the prepolymer are preferred.

Applications of the water-based polyurethane resin composition of the present invention include paints, adhesives, surface modifiers, organic and / or inorganic powder binders, molded articles, and the like.
Specifically, glass fiber sizing agent, thermal paper coating agent, inkjet paper coating agent, printing ink binder agent, steel plate coating agent, agricultural film coating agent, glass, slate, concrete and other inorganic structural material coatings Wood paint, fiber treatment agent, sponge, puff, gloves, condom and the like. Among these, it is preferable to use it as a coating material for paint, wood, paper, fiber, glass, electronic material parts, and steel plates, and it is particularly preferable to use it as a paint for surface-treated steel plates.

  When the aqueous polyurethane resin composition of the present invention is used as a paint, for example, brush coating, roller coating, spray coating, gravure coating, reverse roll coating, air knife coating, bar coating, curtain roll coating, dip coating, rod coating, It can apply | coat to a base material by the method selected suitably, such as a doctor blade coat.

  The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples.

[Production of Urethane Prepolymer (PP-1)]
Obtained from 28 g (0.098 mol) of 1,12-dodecanediol as component (a) and 1,6-hexanediol, adipic acid and isophthalic acid (adipic acid / isophthalic acid mass ratio is 50/50) as other polyols 158 g (0.090 mol) of the obtained polyester polyol (number average molecular weight 1750) and 15.8 g (0.118 mol) of dimethylolpropionic acid, dicyclohexylmethane-4,4′-diisocyanate (hydrogenated MDI) as polyisocyanate 128 g (0.489 mol) was charged to the reaction flask.
The NCO index (NCO / OH equivalent ratio) at this time is 1.6, and the acid value is 20 mgKOH / g.

  Further, 170 g of N-methyl-2-pyrrolidone was added as a solvent and reacted at 90 to 110 ° C. under a nitrogen stream for 2.5 to 3.5 hours, so that NCO% was 3.1% or less. As a result, a urethane prepolymer (PP-1) having a solid content of 66% by mass was obtained.

[Production of Urethane Prepolymers PP-2 to PP-7]
Except for using the compounds shown in Table 1 below, the urethane prepolymer was prepared in the same manner as in the production of the urethane prepolymer PP-1, except that the NCO index (NCO / OH equivalent ratio), acid value, solid content, and other conditions were the same. PP-2 to PP-7 were produced.

[Example 1]
Antifoaming agent (manufactured by ADEKA, B1016) 0.5 g in water 522 g, and triethylamine 10.7 g (0.106 mol) so that the neutralization rate with PP-1 is 1.0. In an aqueous solution obtained by stirring, 450 g of the urethane prepolymer PP-1 was added and stirred at 20 to 40 ° C. for 15 minutes, and then diethylenetriamine / water (1/3) was used as component (b). ) 13.6 g (0.033 mol) of the mixed solution was dropped, and the mixture was stirred at 20 to 40 ° C. for 10 minutes.
Further, 34.4 g (0.050 mol) of an adipic acid dihydrazide / water (1/3) mixed solution was added as another chain extender, and the mixture was stirred at 20 to 40 ° C. for 1 to 2 hours until the NCO group disappeared. An aqueous polyurethane resin composition having a solid content of 30% was obtained.

[Examples 2 to 4]
A water-based polyurethane resin was produced in the same manner as in Example 1 except that the compounds shown in Table 2 below were used, and the solid content, neutralization rate, amount of antifoaming agent, and other conditions were the same.

[Comparative Examples 1 to 7]
A water-based polyurethane resin was produced in the same manner as in Example 1 except that the compounds shown in Table 3 below were used, and the solid content, neutralization rate, amount of antifoaming agent, and other conditions were the same.
In Comparative Example-3, the water dispersibility was poor and the performance evaluation of the coating film could not be performed.

<Performance evaluation>
The water resistance, acid resistance, alkali resistance and adhesion of the coating films of the aqueous polyurethane resin compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 8 were evaluated as follows.
These results are shown in Table 1 or Table 2.

[Create specimen]
Examples 1-5 and Comparative Examples on electrogalvanized steel sheets that were degreased after using an electrogalvanized steel sheet as a substrate and degreasing at 60 ° C. for 5 minutes using a degreasing agent having a pH of 11-13. The water-based polyurethane resin composition obtained by 1-4 was apply | coated by 1 micrometer thickness, and it heat-dried so that the plate temperature of a steel plate might be 75 degreeC in 300 degreeC atmosphere for 4 second, and the test body was created.

[Water resistance test]
Using the test specimen, a water resistant spot test was conducted for 24 hours at 65 ° C./95% relative humidity, and the state of the coating film after the test was visually evaluated according to the following criteria.
5: No abnormality in the coating film.
4: The float of the coating film is 5% or less of the total area.
3: The float of a coating film is 6 to 20% of the total area.
2: The float of the coating film is 21% or more of the total area.
1: The coating film is completely peeled off.

[Acid resistance test]
Using the test body, the state of the coating film after being immersed in a 1% H ₂ SO ₄ aqueous solution (25 ° C.) for 24 hours was visually evaluated according to the following criteria.
5: No abnormality in the coating film.
4: The float of the coating film is 5% or less of the total area.
3: The float of a coating film is 6 to 20% of the total area.
2: The float of the coating film is 21% or more of the total area.
1: The coating film is completely peeled off.

[Alkali resistance test]
Using the test body, the state of the coating film after being immersed in a 1% NaOH aqueous solution (25 ° C.) for 1 hour was visually evaluated according to the following criteria.
5: No abnormality in the coating film.
4: The float of the coating film is 5% or less of the total area.
3: The float of a coating film is 6 to 20% of the total area.
2: The float of the coating film is 21% or more of the total area.
1: The coating film is completely peeled off.

[Adhesion]
A water-based polyurethane resin composition was applied to an untreated electrogalvanized steel sheet to a thickness of 1 μm, and then dried in an atmosphere of 300 ° C. for 15 seconds so that the steel sheet temperature was 150 ° C. Obtained. The coating film of the test piece was cross-cut and the degree of peeling with a tape was evaluated according to the following criteria.
5: No abnormality in the coating film.
4: A slight float (area of 5% or less) is observed in the coating film.
3: A slight float (over 5%, area of 20% or less) is observed in the coating film.
2: Many floats (area over 20%) are observed in the coating film.
1: The coating film is completely peeled off.

From the results of the examples and comparative examples, it was confirmed that only the water-based polyurethane composition of the present invention had good results in all of water resistance, chemical resistance and adhesion.
Further, any one of (a) a mixing ratio of a long-chain alkylene diol compound having 10 to 32 carbon atoms, a mixing ratio of a specific polyalkylene polyamine compound (b) in the chain extender, and a mixing ratio of the chain extender In any case, it was confirmed that the water resistance and the chemical resistance were lowered when the requirements of the present invention were not satisfied.

  Since the water-based polyurethane resin composition of the present invention is water-based, it not only destroys the environment, but also has good workability, and also has a coating film excellent in chemical resistance such as water resistance, acid resistance, and alkali resistance. Since it is formed, it is suitable for producing materials and molded articles having excellent water resistance and chemical resistance by painting on the surface of wood, paper, fiber, glass, electronic material parts, steel plates and the like.

Claims (6)

An aqueous polyurethane resin composition containing an aqueous polyurethane resin obtained by reacting a chain extender with a urethane prepolymer obtained by reacting a polyisocyanate and a polyol, and comprising 5 to 35% by mass of the polyol component Is a long chain alkylene diol compound (a) having 10 to 32 carbon atoms, and the chain extender contains a polyalkylene polyamine compound (b) represented by the following general formula (1), The content of the component (b) is such that the amino group equivalent of the polyalkylene polyamine compound is 0.2 to 1.0 when the equivalent of the amino group in the total chain extender is 1. In addition, the content of the total chain extender is such that the equivalent of the amino group of the total chain extender is 0.5 to 0.9 with respect to 1 equivalent of the isocyanate group of the urethane prepolymer. Characterized the door, aqueous polyurethane resin composition;

However, ^{R 1} in the formula (1) is an alkylene group having 1 to 6 carbon atoms, n is the number of 2-4. The water-based polyurethane resin composition according to claim 1, wherein the polyisocyanate is at least one diisocyanate selected from the group consisting of aromatic diisocyanates, alicyclic diisocyanates, and aliphatic diisocyanates . In the general formula (1), ^{R 1} is ethylene _(-CH 2 CH ₂ -) with a radical, n is 2 or 3, claim 1 or an aqueous polyurethane resin compositions described 2.   A paint comprising the aqueous polyurethane resin composition according to any one of claims 1 to 3.   A coated product obtained by applying the coating material according to claim 4 to a plate-like material.   The coated product according to claim 5, wherein the plate-like material is a surface-treated steel plate.