Patent ID: 9303181
Filing Date: 2016-04-05
CPC Classification: C08F,C08G,C08L,C09D

Claim Text:
1. A process for making polyurethane/acrylic hybrid dispersions comprising the following continuous steps: i) adding at least one polyol consisting of polyether polyols, polyester polyols, polycarbonate polyols, or mixtures thereof into a reactor; ii) adding dimethylolpropionic acid (DMPA) simultaneously with step i), or after step i) but before step iii), as water dispersibility enhancing agent at a temperature of from 115° C. to 140° C. to obtain a homogeneous solution; iii) adding at least one polyisocyanate at a temperature of from 75° C. to 95° C. until NCO content reaches a constant value to prepare a polyurethane prepolymer; iv) adding at least one acrylate monomer, at least one styrenic monomer, or a mixture thereof, as diluent to the polyurethane prepolymer, at a temperature of from 40° C. to 65° C.; v) adding a neutralizing agent; vi) dispersing the polyurethane prepolymer in the presence of the acrylate monomer, and/or the styrenic monomer of step iv); and vii) adding at least one ethylenically unsaturated nonionic monomer, and co-polymerizing it together with the acrylate monomer, and/or the styrenic monomer of step iv), to get the polyurethane/acrylic hybrid dispersion.