| 摘要 |
A process for the production of rigid shaped articles, which may have reinforcing material embedded therein, comprises subjecting to polymerizing conditions a fluid composition having an absolute viscosity of 30 to 3000 centipoises at 0 DEG C. and comprising a dispersion of a finely-divided vinyl chloride homopolymer or copolymer of at least 95 weight per cent vinyl chloride with not more than 5 weight per cent of one or more ethylenically unsaturated compounds in a mixture of a vinyl aromatic hydrocarbon and either (a) a dialkyl fumarate in which each alkyl group contains 2 to 8 carbon atoms, or (b) a cyclohexyl or alkyl ester of acrylic or methacrylic acid in which the alkyl group contains 4 to 12 carbon atoms, said composition having incorporated therein a minor proportion of peroxide polymerization catalyst or initiator. Specified copolymers are copolymers of vinyl chloride with vinyl acetate, vinyl propionate, methyl acrylate, butyl acrylate, methyl methacrylate, lauryl methacrylate and vinylidene chloride. Specified vinyl aromatic hydrocarbons are styrene, the vinyl toluenes, vinyl xylene and ethylvinyl benzene. Specified esters are diethyl, dibutyl, dihexyl and di-2-ethylhexyl fumarates; butyl, hexyl, 2-ethylhexyl, lauryl and cyclohexyl acrylates; and butyl, hexyl, 2-ethylhexyl and cyclohexyl methacrylates. Specified catalysts are benzoyl peroxide, acetyl peroxide, lauroyl peroxide, dicumyl peroxide, #t-butyl perbenzoate, #t-butyl peracetate and di-#t-butyl diperphthalate. The compositions may also comprise pigments, dyes, antioxidants, inhibitors and stabilizers, e.g. dibutyl tin dilaurate, barium/cadmium soaps and organotin mercaptides. The compositions may be used to coat or impregnate reinforcing materials, e.g. mats or sheets of cloth, wood fibres, cotton linters, glass fibres, glass cloth; and then cured by heating to polymerize the monomers to produce reinforced polymeric products. Examples describe the curing in moulds of compositions reinforced with chopped strand fibre glass and comprising polyvinyl chloride, vinyl toluene (mixture of meta and para isomers), dicumyl peroxide and dibutyl tin dilaurate together with (1, 3, 4 and 7) diethyl fumarate; (2) diethyl fumarate, dibutyl fumarate, di-2-ethylhexyl fumarate, butyl acrylate, cyclohexyl acrylate, lauryl acrylate or butyl methacrylate; (5) di-2-ethylhexyl fumarate; or (6) butyl methacrylate. |
