| 摘要 |
1,211,817. Unsaturated polyester compositions. SOC ITALIANA RESINE S.p.A. 30 June, 1969 [15 July, 1968], No. 33013/69. Heading C3P. Stable and photochemically hardenable unsaturated polyester compositions comprise: (a) an unsaturated polyester prepared by mixing styrene with a polycondensation product of a hydroxyl number not below 40, formed from a polycarboxylic acid and a polyhydroxylic alcohol, wherein the acid or alcohol contains non-aromatic unsaturation, the polycarboxylic acid being optionally partially replaced by a saturated dicarboxylic acid; (b) a stabilizing system composed of 200 to 800 p.p.m., by weight of the polyester, of an alkyl phosphite or aryl phosphite and 10 to 50 p.p.m., by weight of the polyester, of a copper salt of an organic acid; and (c) 0À1 to 5.0%, by weight of the polyester, of benzoin or a benzoin derivative having an alkyl group of 1 to 8 carbon atoms in the alpha position. In the examples the compositions comprise a polyester derived from propylene glycol, fumaric acid and phthalic acid, styrene, benzoin-bisphenol polyester resin powder, hydroquinone, copper naphthenate solution, triphenyl phosphite and p-tert-butyl catechol and are irradiated with ultra-violet light on a glass plate. |
