Process for the production of strain-free masses from crossedlinked polymerized methylmethacrylate

Claim 1

A PROCESS FOR THE FORMATION OF THICK MASSES OF VOID-FREE AND STRAIN-FREE SYNTHETIC RESINOUS MATERIAL FROM SMALLER MASSES OF A SWWLLABLE, INSOLUBLE, CROSS-LINKED COPOLYMER OF METHYLMETHACRYLATE AND A COPOLYMERIZABLE CROSS-LINKING AGENT WHICH IS AN ETHYLENICALLY UNSATURATED COMONOMER WHICH IS COPOLYMERIZABLE WITH THE METHACRYLATE COMPOUND AND WHICH CROSS-LINKING AGENT IS SELECTED FROM THE GROUP CONSISTING OF DIVINYL BENZENE, DIVINYL ETHER, DIVINYL SULPHIDE, DIVINYL ACETYLENE, ACRYLIC ANHYDRIDE, METHACRYLIC ANHYDRIDE, CROTONIC ANHYDRIDE, ESTERS OF POLYHDRIC ALCOHOLS WITH ACRYLIC ACID, ALPHA-SUBSTITUTED ACRYLIC ACID AND CROTONIC ACID, AND DIALLYL SEBACATEM WHICH CONSISTS IN SUBJECTS SAID SMALLER MASSES TO AT LEAST ONE CYCLE OF OPERATIONS COMPRISING SWELLING IN A NORMALLY LIQUID POLYMERIZABLE ETHYLENICALLY UNSATURATED COMPOUND SELECTED FROM THE GROUP CONSISTING OF METHYLMETHACRYLATE, BUTYL METHACRYLATE, BUTYL ACRYLATE, AND VINYL ETHYL KETONE AND THEREAFTER POLYMERIZING THE ABSORBED MONOMER BY MEAND OF HEAT.