Patent ID: 8383748
Filing Date: 2013-02-26
Classification: B29C,B29K,C08F

Abstract:
1. Process for the preparation of impact-strengthened cast PMMA sheets comprising the following stages: 1) heating a mixture comprising: to a temperature sufficient to activate the alkoxyamine and polymerize the monomer(s); 2) reactivating the central block B, optionally mixed with the unconsumed monomer(s) from stage 1, in the presence of the monomer(s) intended to form the branches A; 3) adding methylmethacrylate (MMA) and optionally at least one comonomer M which can be copolymerized by the radical route with methyl methacrylate (MMA) and at least one radical initiator to the mixture obtained in stage 2; 4) casting the mixture from stage 3 in a mould and then heating, to form an impact-strengthened cast PMMA sheet, wherein no desolventization step occurs between steps 2) and 3).