Patent ID: 6500447
Filing Date: 2002-12-31
Classification: A01N

Abstract:
A pH-sensitive microcapsule which-comprises a water-immiscible active ingredient contained within a shell wall wherein said shell wall has free carboxylic acid groups incorporated therein, and whereina) the shell wall is selected from the group consisting of a polyamide having free carboxylic acid groups incorporated therein, a polyester having free carboxylic acid groups incorporated therein, a polyamide/polyester copolymer having free carboxylic acid groups incorporated therein and a cross-linked amino resin having free carboxylic acid groups incorporated therein, b) the polyamide shell wall is formed from a polyacid halide and a polyamine, the polyester shell wall is formed from a polyacid halide and a polyol, the polyamide/polyester shell wall is formed from a polyacid halide, a polyamine and a polyol, and the cross-linked amino resin shell wall is formed from a polyacid halide and a water-immiscible amino resin prepolymer, and c) the ratio of acid halide groups to amino and/or hydroxy groups in the polyamide, polyester or polyamide/polyester shell wall is greater than 1:1 and less than about 5:1.