HEAT-RESISTANT ADHESIVE LACQUERS AS WIRE COATINGS

摘要

1477395 Polyurethane - esterimides / epoxy resins SCHWEIZERISCHE ISOLA-WERKE 12 Sept 1974 [13 Sept 1973] 39845/74 Headings C3B and C3R Heat curable adhesive lacquers for coating electrically insulated conductors, e.g. wires consist essentially of a mixture of (1) a polyurethane-esterimide having terminal isocyanate groups blocked by a monohydric phenol and being derived from (A) an ester-imide containing OH groups obtained from a dicarboxylic acid of the formula and a polyalcohol of the formula and of the formula in the molar ratios a : (b 1 +b 2 )= 1 : 1À2 to 1 : 2, b 1 : b 2 = 1 : 1 to 10 : 1 and (B) a polyfunctional isocyanate of the formula or a mixture of two or more thereof and the ratio of the hydroxyl groups to the isocyanate groups is from 1 : 1 to 1 : 1À5 and (2) an essentially linear epoxide resin having secondary OH groups and a molecular weight of at least 30,000 in or organic solvent. The epoxide resin is suitably a condensation product of bisphenol A and epichlorohydrin. Wires coated with the adhesive may be formed into a coil and stuck together by heating.