| 摘要 |
A method for preparing an advanced epoxy cationic resin from an epoxy-based resin containing oxirane groups by converting at least some of the oxirane groups to cationic groups, wherein the improvement is using as the epoxy-based resin a blend of (I) an epoxy-based resin obtained by reacting in the presence of a suitable catalyst (1) a diglycidylether of a polyetherpolyol, such as a condensation product of dipropylene glycol and epichlorohydrin having an epoxy equivalent weight of 185, 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-based resin. Such resin blends can be utilized in cathodic electrodeposition coating systems. Use of the diglycidylether of a polyetherpolyol provides coating compositions with lower viscosity and produces deposition coatings of higher film build than compositions without this component.
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