Patent ID: 6180180
Filing Date: 2001-01-30
Classification: C08G

Abstract:
An aqueous two-component polyurethane coating composition comprising(I) a component (I) comprising a binder (A) comprising(A1) at least one water-soluble or water-dispersible polyester resin comprising hydroxyl groups and acid groups which can be converted into the corresponding acid anion groups, wherein said resin has an OH number of from 30 to 250 mg of KOH/g and an acid number of from 5 to 150 mg of KOH/g,(A2) at least one water-soluble or water-dispersible polyurethane resin comprising hydroxyl groups and acid groups which can be converted into the corresponding acid anion groups, wherein said resin has an OH number of from 20 to 200 mg of KOH/g and an acid number of from 5 to 150 mg of KOH/g,(A3) a resin having an OH number of from 40 to 200 mg of KOH/g and an acid number of from 5 to 150 mg of KOH/g selected from the group consisting of at least one water-soluble or water-dispersible acrylate copolymer comprising hydroxyl groups and acid groups which can be converted into the corresponding acid anion groups, an acrylated polyester, an acrylated polyurethane, and mixtures thereof, and(A4) optionally, at least one further polymer, and(II) a component comprising a free polyisocyanate component (F1) as crosslinking agent, wherein the mixing ratio of the polyester resin (A1) to the polyurethane resin (A2) is between 95 parts by weight of polyester resin: 5 parts by weight of polyurethane resin and 5 parts by weight of polyester resin: 95 parts by weight of polyurethane resin.