IMPACT RESISTANT METHACRYLIC RESIN COMPOSITION

摘要

An impact resistant methacrylic resin composition having improved transparency, weatherability and impact resistance comprising a multi-layer graft copolymer and a methacrylic resin is disclosed. The multi-layer graft copolymer is prepared through 3 step polymerizations as follows: in the first step, a semi-soft copolymer is prepared by polymerizing specific amounts of an alkyl methacrylate having an alkyl group with 1 to 4 carbon atoms, styrene and/or its derivative, alkyl acrylate having an alkyl group with 1 to 8 carbon atoms and a specific polyfunctional monomer; in the second step, a soft copolymer containing alkyl acrylates having an alkyl group with 1 to 8 carbon atoms as the main unit is prepared so that the semi-soft copolymer is included in the inner layer of the soft copolymer; and in the third step, a methacrylic polymer or copolymer is prepared by polymerizing monomers main component of which is alkyl methacrylates having an alkyl group with 1 to 4 carbon atoms or a mixture thereof to form an outermost layer. The third step may be divided into two or more steps. The multi-layer methacrylic copolymer thus obtained is compounded with and dispersed in a methacrylic resin the unit of which is methyl methacrylate.