Aqueous dispersion of polyurethane resins, a method of manufacturing them, coating agents containing them and use thereof

摘要

A method of manufacturing aqueous dipsersion of polyurethane resins free from urea groups and containing ionic groups and suitable for coating agents, with a number average moleculear weight (Mn) of 10,000 to 300,000 and an acid number of 5 to 50, by preparing a polyurethane prepolymer containing OH groups and with an OH number of 5 to 75 and a number average molecular weight (Mn) of 5,000 to 50,000.