Patent ID: 6776996
Filing Date: 2004-08-17
Classification: A01N

Abstract:
A process for preparing a coated pesticidal matrix which includes a pesticidal agent which itself is substantially inactivated by ultra-violet radiation, but which when included in said coated matrix retains a significant amount of its original pesticidal activity, which process consists essentially of(a) preparing an aqueous mixture containing said pesticidal agent, a pH-dependent polymer selected from the group consisting of ethyl acrylate/methacrylic acid copolymers, methyl methacrylate/methacrylic acid copolymers, methacrylic acid/methyl acrylate/methyl methacrylate copolymers and mixtures thereof, a base, optionally a plasticizer, optionally an ultraviolet protector, optionally an activity enhancer, optionally a glidant, and water; â€ƒwherein the polymer (1) contains ester groups and free carboxylic acid groups, (2) is partially solubilized due to the action of the base, and (3) has solubilization pH greater than pH 5.5; â€ƒwherein the amount of base added is well below the amount required to fully solubilize the copolymer such that no more than 10% of the free carboxylic acid groups of the copolymer are converted to salts; â€ƒwherein the mixture's pH is less than the polymer's solubilization pH; and (b) drying the mixture to produce a coated pesticidal matrix.