Process for preparing bead polymers in aqueous medium containing calcium phosphate and an amino polyacetic acid compound

Claim 1

IN A PROCESS FOR PREPARING A BEAD POLYMER BY POLYMERIZING A MATERIAL COMPRISING AT LEAST ONE SUSPENSIONPOLYMERIZABLE VINYLIDENE MONOMER OF THE GROUP CONSISTING OF METHYL METHACRYLATE, A VINYL ESTER, STYRENE, AN ARMETHYLSTYRENE, A DICHLOROSTYRENE, AND VINYL NAPHTHALENE IN THE PRESENCE OF A FREE RADICAL POLYMERIZATION INITIATOR IN SUSPENSION IN AN AQUEOUS MEDIUM CONTAINING AOBUT 0.15%, BASED ON THE WEIGHT OF THE POLYMERIZABLE MATERIAL, OF A FINELY-DIVIDED CALCIUM PHOSPHATE SUSPENDING AGENT, THE IMPROVEMENT WHICH COMPRISES CONDUTING THE POLYMERIZATION IN THE PRESENCE OF ABOUT 0.5-15%, BASED ON THE WEIGHT OF THE SUSPENDING AGENT, OF AN AMINO POLYACETIC ACID COMPOUND OF THE GROUP CONSISTING OF AMINO POLYACETIC ACIDS AND THE ALKALI METAL SALTS, ALKYLAMINE SALTS, DIALKYLAMINE SALTS, AND ALKYL ESTERS OF AMINO OLYACETIC ACIDS.