| 摘要 |
<p>1468699 Moulding compositions based on unsaturated polyesters E I DU PONT DE NEMOURS & CO 13 Dec 1974 [17 Dec 1973] 54037/74 Heading C3P A moulding composition comprises a fibrous reinforcing material and (a) 19 to 80% by weight of an ethylenically unsaturated polyester (b) 19 to 80% by weight of an ethylenically unsaturated monomer and (c) 1 to 25% by weight of a thermoplastic copolymer soluble in mixtures of (a) and (b) having a molecular weight of 5000 to 300,000 and containing (i) methylmethacrylate units, (ii) ethyl acrylate, n-butyl methacrylate and/or isobutylmethacrylate units and (iii) itaconic anhydride or the percentages of (a), (b) and (c) being based on their total weight. The composition may also contain maleic anhydride units, one or more of an alkaline earth metal oxide or hydroxide, an inert non-fibrous filler and a mould release agent. In the examples a mixture of styrene, a polyester of maleic acid and propylene glycol, a terpolymer of methylmethacrylate, isobutyl methacrylate and maleic or itaconic anhydride, glass fibres, calcium carbonate, zinc stearate and tert. butyl perbenzoate is compression moulded at 300‹ C. and for comparison the terpolymer is omitted or replaced by a copolymer of methylmethacrylate and ethylacrylate or isobutyl acrylate and plus methacrylic acid.</p> |
