Abstract: Flame retardant molding compounds comprising polymers of methyl methacrylate having an average molecular weight between 1.times.10.sup.5 and 2.times.10.sup.5, which molding compounds contain from 8 to 15 weight percent of at least one chloroalkylphosphoric acid ester of the formula ##STR1## wherein R.sub.1 is alkyl or ##STR2## and R.sub.2 is hydrogen, methyl, ethyl, or chloro-substituted methyl or ethyl.

Abstract: What is disclosed are a method for making a transparent impact-resistant polymer comprising a rubbery phase of grafted polybutadiene and a hard copolymer phase, which polymer is adaptable to use as a molding material, which method comprises:(1) in a first polymerization stage, dissolving a solid polybutadiene rubber in a monomer mixture comprising (a) methyl methacrylate, (b) styrene, and (c) at least one of methyl acrylate or ethyl acrylate to give a solution containing from 3 to 10 percent by weight of said rubber, and then polymerizing the solution using an initiator promoting graft copolymerization and in the presence ab initio of a chain transfer agent until an amount of said monomer mixture which is one to two times the weight of said polybutadiene rubber introduced is converted, said monomers (a), (b), and (c) being present in said monomer mixture in a ratio by weight of (73.+-.5): (22.+-.2); (5.+-.