Ube Industries, Inc.

Manabu Takahashi

Masahiro Naiki

Atsushi Morikami

Fumio Adachi

Taku Nakamura

The present invention is to provide an aqueous polyurethane resin dispersion in which a polyurethane resin s dispersed in an aqueous medium, wherein the polyurethane resin is obtained by reacting (A) a polyurethane prepolymer which is obtained by reacting (a) a polyisocyanate compound, (b) a polyol compound containing a polycarbonate polyol having a number average molecular weight of 800 to 3500, and (c) an acidic group-containing polyol compound, and (B) a chain extender, being dispersed in an aqueous medium, (B) the chain extender contains a polyamine compound having three or more in total of an amino group(s) and/or an imino group(s) per molecule, and the polyurethane resin has, each based on a solid content, a content of urethane bonds of 5 to 10% by weight, a content of urea bonds of 2 to 7% by weight, a content of carbonate bonds of 15 to 40% by weight, has neither ether bond nor ester bond, has a density of cross-linking points of 1.0&#xd7;10to 1.0&#xd7;10mol/g, an acid value of 12 to 20 mg KOH/g, and a weight average molecular weight of 100,000 or more.

Aqueous polyurethane resin dispersion and coating composition comprising the same

An aqueous polyurethane resin dispersion containing a polyurethane resin obtained by reacting (A) a polyurethane prepolymer obtained by reacting (a) a polyisocyanate compound, (b) at least one polyol compound containing a polycarbonate polyol having a number average molecular weight of 400 to 3000, (c) an acidic group-containing polyol compound, (d) a blocking agent for an isocyanate group, which dissociates at 80 to 180&#xb0; C., and (B) a chain elongating agent having reactivity with the isocyanate group, being dispersed in an aqueous medium, a sum of a content of urethane and urea bondings is 15 to 30% by weight in terms of solid components, a content of carbonate bondings is 8% to &#x3c;15% by weight in terms of solid components, and a content of isocyanate group to which the above-mentioned blocking agent has bound is 0.2 to 3% by weight in terms of solid components as calculated on isocyanate group.

Aqueous polyurethane resin dispersion and process for preparing the same

An aqueous polyurethane resin dispersion containing a polyurethane resin obtained by reacting (A) a polyurethane prepolymer obtained by reacting (a) a polyisocyanate compound, (b) at least one polyol compound containing a polycarbonate polyol having a number average molecular weight of 400 to 3000, (c) an acidic group-containing polyol compound, and (d) a blocking agent for an isocyanate group, which dissociates at 80 to 180&#xb0; C., and (B) a chain elongating agent having reactivity with the isocyanate group, being dispersed in an aqueous medium, a sum of a content of urethane bondings and a content of urea bondings is 7 to 18% by weight of solid components, a content of carbonate bondings is 15 to 40% by weight of solid components, and a content of an isocyanate group to which the above-mentioned blocking agent has bonded is 0.2 to 3% by weight of solid components and calculated on the isocyanate group.

Disclosed is an aqueous polyurethane resin dispersion which comprises a polyurethane resin which is obtained by reacting (A) a polyurethane prepolymer obtained by reacting (a) a polycarbonate polyol having an alicyclic structure in the main chain, (b) an acidic group-containing polyol compound and (d) a polyisocyanate, and (B) a chain-elongating agent, being dispersed in an aqueous medium, a carboxylic acid group content of the above-mentioned (A) polyurethane prepolymer based on a solid component of (A) the polyurethane prepolymer is 2.0 to 13.0% by weight, and a number of a hydroxyl equivalent of a mixture of the above-mentioned (a) polycarbonate polyol having an alicyclic structure in the main chain, the above-mentioned (b) acidic group-containing polyol compound, and, if necessary, (c) a polyol other than (a) and (b) is 70 to 270.

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Ube, Japan

Manabu Takahashi