Difficult yellow deformation epoxy denaturation water polyurethane resin

摘要

PURPOSE:The subject composition containing the reaction product of an carboxyl group-containing aqueous polyurethane resin with an epoxy group-containing bisphenol type epoxy compound, having excellent weather resistance and boiling water resistance, and useful for coatings, adhesives, paper-processing agents, etc. CONSTITUTION:The objective composition containing a product obtained by reacting (A) 100 pts.wt. of a carboxyl group-containing aqueous polyurethane resin with (B) 1-30 pts.wt. of an epoxy group-containing bisphenol type epoxy compound. The composition is obtained by dissolving or suspending the mixture of the carboxyl group-containing urethane prepolymer with the bisphenol type epoxy compound in a solvent, imparting the hydrophilicity to the carboxyl group-containing urethane prepolymer and simultaneously reacting the product with a chain-extending agent by a method in which a basic organic compound and the chain-extending agent are dropped, etc., diluting the reaction product with water, removing the water and the solvent under vacuum up to an nonvotatile matter concentration of 30-40%, and further subjecting the remained product to the reaction at 70-80 deg.C for approximately 6hrs.