Electrical insulating powder for providing wire coating
AssigneeMinnesota Mining and Manufacturing Company
InventorCurtis R. Guilbert
Life of this patent
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Abstract
A carboxy-functional curative for epoxy resins comprising the reaction product of trimellitic anhydride and capped epoxy resins, the capped resins comprising a hydantoin diepoxide or a diglycidol ether of bisphenyl A reacted with benzoic acid or phenyl. The curative is used in conjunction with a thermosettable epoxy resin powder composition useful for applying electrically insulating coatings to electrical wire.
Claims10
A carboxy-functional adduct capable of acting as a curative for an epoxy resin comprising the reaction production of:
- (a) the reaction product of an epoxy resin selected from an hydantoin diepoxide and a diglycidyl ether of bisphenol A and, per mole of said epoxy resin, 2 moles of a reactant selected from the group consisting of phenol and benzoic acid;
- and
- (b) 2 moles per mole of said epoxy resin of trimellitic anhydride.
A powder suitable for applying electrically insulating coatings to wire comprising a blend of:
- (a) a polyglycidyl ether of bisphenol A capped with a monobasic aromatic acid or a monobasic aromatic phenol in an amount of from about 1 to about 5 percent by weight of said polyglycidyl ether, said capped polyglycidyl ether having an epoxide equivalent weight of from about 1200 to about 2200 and an epoxide functionality of from about 1.2 to about 1.6;
- and
- (b) a carboxy functional adduct comprising the reaction product of:
- (i) the reaction product of an epoxy resin selected from the group consisting of an hydantoin diepoxide and a diglycidyl ether of bisphenol A and, per mole of said epoxy resin, 2 moles of a reactant selected from the group consisting of phenol and benzoic acid;
- and
- (ii) 2 moles, per mole of said epoxy resin, of trimellitic anhydride;
- said adduct being present at a concentration such that about 0.9 to about 1.5 equivalents of carboxyl groups are present per capped polyglycidyl ether epoxide equivalent.
Dependencies are inferred from the claim text.