| 摘要 |
<p>1,174,318. Polyester wire varnish resin. GENERAL ELECTRIC CO. 20 Sept., 1967 [10 Oct., 1966], No. 42753/67. Heading C3R. A polyester wire-varnish resin has its properties improved by refluxing a 35 to 40% solution of the resin for 2-8 hours. The polyester is the reaction product of (a) from 25 to 56 equivalents per cent of isophthalic and/or terephthalic acid or their lower dialkyl esters, (b) from 15 to 46 equivalents per cent of ethylene glycol and (c) from 13 to 44 equivalents per cent of a saturated polyhydric alcohol having at least three hydroxyl groups, e.g. glycerol. The resin solvent is preferably a phenol, a polyalkyl benzene, a high boiling petroleum hydrocarbon or mixtures thereof. The refluxing solution may also contain a polyisocyanate, e.g. a phenol blocked reaction product of trimethylol propane and tolylene diisocyanate.</p> |
