Patent ID: 8791204
Filing Date: 2014-07-29
Classification: C08F,C08J,C08L,C09D

Abstract:
1. A process for the manufacture of a polymer dispersion comprising the steps of i) providing a mixture comprising from 2 to 60 parts by weight of a first polypropylene polymer having sufficient carboxylic acid and/or carboxylic acid anhydride groups equivalent to an acid value of from 2 to 50 mg KOH/g nv polymer, and from 40 to 98 parts by weight of a second polymer having a molar excess of functional groups capable of reacting with the carboxylic acid and/or carboxylic acid anhydride groups of the polypropylene; 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) causing some of the carboxylic acid and/or carboxylic acid anhydride groups of the polypropylene to react with at least some of the functional groups of the second polymer to form a reaction mixture, under conditions of high shear in an extruder; iv) rapidly cooling the reaction mixture outside the extruder to form a solid product; and v) contacting the solid product with an organic liquid; wherein the organic liquid is chosen to be a good solvent for the second polymer and a poor solvent for the polypropylene polymer whereby a dispersion comprising polypropylene particles in a solution of the second polymer dissolved in the organic liquid is formed.