Mar-resistant synthetic resin shaped article

Claim 1

A synthetic resin shaped article having a mar-resistant polymer surface layer integrated with the polymer body, said polymer surface layer consisting essentially of, in polymerized form, a. a compound having a total of at least three acryloxy (CH 2 =CH.CO.O--) and/or methacryloxy (CH 2 =C(CH 3 ).CO.O--) groups in the molecule, said acryloxy and methacryloxy groups being linked with a straight chain aliphatic hydrocarbon residue having not more than 20 carbon atoms or a straight chain aliphatic hydrocarbon residue having at least one ether linkage in the main chain and having not more than 20 carbon atoms and b. at least one copolymerizable mono- or diethylenically unsaturated compound, the ratio by weight of compound (b)/compound (a) being 0/100 to 80/20 when compound (b) is a diethylenically unsaturated compound and 0/100 to 30/70 when compound (b) is a monoethylenically unsaturated compound, and said polymer surface layer having a mar-resistance to an extent such that no appreciable scratches are produced when a 25 mm diameter pad composed of No. 000 steel wool is rotated 100 revolutions at a rate of 40 R.P.M. while being pressed against the shaped article at a load of 1,000 g. and being prepared by completely polymerizing the monomer charge in an air-free atmosphere and in the presence of not greater than 5% by weight of an initiator, said initiator being at least one compound selected from the group consisting of azobisisobutyronitrile, benzoyl peroxide, lauryl peroxide, benzoin and benzoin alkyl ether having at most 4 carbon atoms in the alkyl group, and said polymer body being selected from the group consisting of polymethyl methacrylate, polycarbonate and a copolymer containing at least 70% by weight of units derived from methyl methacrylate.