Patent ID: 6716951
Filing Date: 2004-04-06
Classification: C08F,G02B

Abstract:
A process for production of methacrylic copolymers, comprising:charging a monomer mixture comprising from 70 to 95% by weight of methyl methacrylate, from 0 to 15% by weight of &agr;-methylstyrene, from 0 to 20% by weight of styrene and from 2 to 15% by weight of maleic anhydride into a polymerizing vessel containing at least one polymeric membrane layer having an oxygen permeability of 1.5Ã—10âˆ’13 (molÂ·mâˆ’2Â·sâˆ’1Â·Paâˆ’1) or below, where when styrene or &agr;-methylstyrene is present the molar ratio of the sum of &agr;-methylstyrene and styrene to maleic anhydride is from 1.0 to 2.5, sealing the polymerizing vessel, and polymerizing the monomer mixture under healing in a gas phase.