Patent ID: 6310157
Filing Date: 2001-10-30
Classification: C08F,D21H

Abstract:
A branched and wholly water soluble anionic polymer which has been made by conventional reverse phase emulsion polymerization of a water soluble ethylenically unsaturated anionic monomer, branching agent and optionally a water soluble, nonionic, ethylenically unsaturated monomer to form an emulsion,and then substantially dehydrating the emulsion to form a stable dispersion of substantially anhydrous polymer droplets dispersed in oil,and wherein the polymer has(a) intrinsic viscosity above 3 dl/g;(b) tan delta rheological oscillation value at 0.005 Hz of above 0.7 or deionised SLV viscosity number which is at least three times the salted SLV viscosity number of the corresponding polymer made in the absence of branching agent;(c) a saline Brookfield viscosity of at least 2 mPa.s and(d) the branching agent is a polyethylically unsaturated monomer used in an amount of from 1 to 10 ppm molar.