Method for preparing aqueous polyacrylate modified polyurethane dispersions

摘要

A novel method for the preparation of an aqueous polyacrylate modified polyurethane dispersion is disclosed. The preparation method includes three main steps:a) preparation of polyacrylate polymer or copolymer emulsion;b) preparation of polyurethane prepolymer with carboxylic groups and neutralization treatment to the carboxylic groups; andc) dispersion and chain-extension of polyurethane prepolymer by adding the polyacrylate emulsion into the polyurethane prepolymer under vigorous agitation, or other mechanical operation.;The aqueous polyacrylate modified polyurethane dispersion has self-crosslinkability when an unsaturated acetoacetoxy compound is used for the preparation of the polyacrylate emulsion.