| 摘要 |
A method for preparing an advanced epoxy cationic resin from an epoxy resin containing oxirane groups by converting at least some of the oxirane groups to cationic groups is improved by using as the epoxy-based resin a blend of (I) an epoxy resin obtained by reacting in the presence of a suitable catalyst (1) a diglycidylether of an aliphatic diol which diol is essentially free of ether oxygen atoms, such as a condensation product of 1,4-butanediol and epichlorohydrin, optionally (2) a diglycidylether of a dihydric phenol, for example a diglycidyl ether of bisphenol A, (3) a dihydric phenol such as bisphenol A, and optionally (4) a capping agent such as p-nonylphenol and (II) a different cationic epoxy resin. Such resin blends can be utilized in cathodic electrodeposition coating systems. Use of the diglycidylether of an aliphatic diol which diol is essentially free of ether oxygen atoms provides coating compositions with lower viscosity and produces deposition coatings of higher film build than compositions without this component.
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