Particulate aqueous polyurethane dispersion and process for producing the same

摘要

The present invention provides particulate aqueous polyurethane dispersions and a process for producing the same. Two diverse polyols are reacted with two different amount of hydrophilic group-containing dihydric alcohols to obtain a hydrophobic prepolymer and a hydrophilic prepolymer respectively, and the two prepolymers obtained are together dispersed in water. After chain-extending the dispersed prepolymers, core-shell aqueous polyurethane dispersions are produced, wherein the shell is made from the hydrophilic prepolymer and the core is made from the hydrophobic prepolymer. The polyurethane product made from the aqueous polyurethane dispersions of the invention has superior solvent resistance and can be employed in industrial coating or surface treatment of leather or textiles.