| 摘要 |
PROBLEM TO BE SOLVED: To concurrently provide excellent heat resistance and wet heat resistance by applying and printing an insulating paint containing a polyester resin obtained when one or more kinds of aromatic polyvalent carboxylic acids, one or more kinds of bivalent alcohol, one or more kinds of polyhydric (trivalent or above) alcohol, and an epoxy resin having the softening point of 60 deg.C or above react on each other on a conductor. SOLUTION: Terephthalate or dimethyl terephthalate is preferably used for aromatic polyvalent carboxylic acid, they are mixed with divalent carboxylic acid having the five-membered ring imide group to obtain an imide-denatured resin, and the heat resistance of an insulating paint containing it is remarkably improved. An epoxy resin having the heat softening point of 60 deg.C or above is used in view of the flexibility of a polyester resin. The aromatic polyvalent carboxylic acids of 25-60 pts.wt., divalent alcohol of 30-60 pts.wt., and trivalent or above alcohol of 10-30 pts.wt. are blended. The epoxy resin of 15-50 pts.wt. is added to the theoretical value of 100 pts.wt. of the polyester resin thus obtained. |
