VERFAHREN ZUR HERSTELLUNG VON GIESSSTÜCKEN AUS METHACRYL-HARZ.

摘要

PCT No. PCT/JP88/01251 Sec. 371 Date Aug. 9, 1990 Sec. 102(e) Date Aug. 9, 1990 PCT Filed Dec. 10, 1988 PCT Pub. No. WO90/06328 PCT Pub. Date Jun. 14, 1990.The present invention is a method for the production of methacrylic type resin molded items which produces methacrylic type resin molded items having excellent mar resistance, weather resistance, heat resistance and the like by contacting (A) a preliminary reaction product obtained by polymerizing a composition composed of a hydrolyzate of an alkoxysilane having a (meth)acryloxy group and silica gel to a reaction ratio of 15 to 60, with (B) a base molding material composed of a (meth)acrylic type partially crosslinked gel polymer obtained by mixing (i) a raw resin material selected from the group consisting of an alkyl methacrylate monomer, mixtures of alpha , beta -ethylenically unsaturated monomers containing an alkyl methacrylate as a main component, and a syrup containing polymers thereof with (ii) a crosslink-polymerizable compound having at least two (meth)acryloyloxy groups in a proportion of from 3 to 100 parts by weight of the crosslink-polymerizable compound per 100 parts by weight of the raw resin, and partially polymerizing them in the presence of a polymerization initiator until a gel fraction of from 15 to 50% is reached, when the polymerization is stopped, and polymerizing them under conditions where a desired shape is given.