| 摘要 |
PURPOSE:To prepare an electrical insulation coating which is soluble in a non- cresol solvent and has a high concentration, by dissolving a specified polyester- amide resin in an organic solvent. CONSTITUTION:A polyester-polyol having an acid value of 20-100 is prepared by esterification, in the presence of an ester exchange catalyst or a polycondensation catalyst, of an organic polycarboxylic acid selected from among organic polycarboxylic acids (anhydrides) and lower alkyl esters thereof with a polyhydric alcohol in the total OH group/total carboxylic group ratio of 1.2-2.5. The polyol is made to react with citric acid in an amount of 5-50mol% of acid components and an organic diamine in an amount of 50-250mol% of citric acid to produce a polyester-amide resin with an acid value of 15-100. The resin is dissolved in a non-cresol solvent containing 50-100% glycol ether solvent of the formula (where R1 is lower alkyl; R2 is H or methyl; n is 1-3) an 0.2-3wt% crosslinking agent (e.g. tetrabutyl titanate) is added to the solution.
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