Encapsulated chemicals for use in controlled time release applications

摘要

Water soluble chemicals are encapsulated, for use in controlled time release applications, by forming a first coating of a dry hydrophobic film-forming material or a sparingly soluble material which provides a dry shield on the chemical and then forming a second coating of a porous cross-linked hydrophilic polymer on the first coating to prevent the substantial dissolution of the resulting encapsulated chemical for a period of time.