Patent ID: 8445584

Claim:
An aqueous polyurethane resin having a Si atom content of 0.05 to 1.5% by weight in a polyurethane resin obtained by reacting compounds consisting of an isocyanate group-terminated prepolymer which comprises 1 to 15% by weight of a polyoxyethylene group in a side chain branched from the main chain and has two or more isocyanate groups at an end of the main chain, and a chain extender which consists of a compound having two or more active hydrogen groups reactive with the isocyanate group and an alkoxysilyl group, wherein the isocyanate group-terminated prepolymer is obtained by reacting compounds from the group consisting of: a polyisocyanate, one or more non-ionic low molecular weight polyol, a macropolyol, and a compound represented by the following general formula (1), wherein the one or more non-ionic low molecular weight polyol is selected from the group consisting of ethylene glycol, propanediol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexandiol, neopentyl glycol, alkane diol comprising 7 to 22 carbon atoms, diethylene glycol, triethylene glycol, dipropylene glycol, cyclohexane dimethanol, alkane-1,2-diol comprising 17 to 20 carbon atoms, hydrogenated bisphenol-A, 1,4-dihydroxy-2-butene, 2,6-dimethyl-1-octene-3,8-diol, bishydroxyethoxy benzene, xylene bishydroxyethylene terephthalate, glycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy-3-hydroxymethylpentane, 1,2,6-hexanetriol, trimethylolpropane, 2,2-bis(hydroxymethyl)-3-butanol, aliphatic triol comprising 8 to 24 carbon atoms, tetramethylolmethane, D-sorbitol, xylitol, D-mannitol and D-mannite, and the compound having two or more active hydrogen groups and an alkoxysilyl group contained in the chain extender is a compound represented by the following general formula (2), wherein R 1 and R 2 are the same or different from each other, and each represents an alkylene group of 1 to 4 carbon atoms; R 3 represents an aliphatic, alicyclic, or aralkyl hydrocarbon group of 6 to 13 carbon atoms; R 4 represents an alkyl group of 1 to 4 carbon atoms; and n represents an integer of 8 to 50, wherein R 5 and R 6 are the same or different from each other, and each represents an alkyl group of 1 to 4 carbon atoms; R 7 and R 8 are the same or different from each other, and each represents an alkylene group of 1 to 4 carbon atoms; and m represents an integer of 1 to 3.