| 摘要 |
<p>1,158,561. Unsaturated polyesters. INSTYTUT TWORZYW SZTUCZNYCH. 12 July, 1966, No. 31187/66. Headings C3P and C3R. [Also in Division D1] An unsaturated polyester is made by reacting together (a) a polyester obtained by partially degrading a polyester of terephthalic acid (or mixture thereof with a minor proportion of another dicarboxylic acid) and a dihydric alcohol and preferably of M.W. below 2000 and (b) a polyester of a dicarboxylic acid other than terephthalic acid and a di- and/or tri-hydric alcohol, at least one of the polyesters containing polymerizable olefinic double bonds. Specified for (a) are products obtained by heating polyethylene terephthalate with ethylene glycol, 1: 2- propylene glycol, 1:3-butylene glycol, diethylene glycol or glycerol and optionally heating the product with a saturated or unsaturated dicarboxylic acid. Specified for (b) are polyesters of maleic anhydride, phthalic anhydride and 1: 2-propylene glycols or 1: 3-butylene glycol and also polyesters derived from succinic or adipic acid. The unsaturated polyesters may be dissolved in a vinyl monomer (e.g. styrene or vinyl toluene) or an allyl or acrylic monomer and the mixture polymerized in the presence of a catalyst (e.g. benzoyl peroxide or M.E.K. peroxide + cobalt naphthenate) and possibly glass fibres.</p> |
