Patent ID: 9000074
Filing Date: 2015-04-07
Classification: C08J,C08L,C09D,C09J

Abstract:
1. A process for the manufacture of an aqueous polymer dispersion comprising the steps of i) providing a mixture of a first and second polymer each having a viscosity greater than 30 Pa·s at 100 s a) from 1 to 60 parts by weight of a first polymer immiscible in aqueous medium and optionally comprising reactive moieties, and b) from 40 to 99 parts by weight of a second polymer comprising dispersing groups, the polymer being miscible in the aqueous medium and optionally further comprising moieties reactive with the moieties on the first polymer, ii) causing the polymers to melt at a chosen temperature under conditions of high shear in an extruder to form an intimate mixture of the polymers, iii) quench cooling the molten mixture of step ii) outside the extruder to form a solid product, iv) contacting the solid product with the aqueous medium, wherein the aqueous medium dissolves the second polymer but not the first polymer to form a dispersion comprising microparticles of the first polymer in an aqueous solution of the second polymer.