Loading patent…
AssigneeNippon Paint Co., Ltd.
InventorsMitsuo Yamada, Ichiro Kawakami, Hiroyuki Nojiri, Toshiyuki Ishii
Estimating the term…
A cathodic electrodeposition paint containing a cationically modified epoxy resin and a crosslinker dispersed in an acidic aqueous medium is disclosed which contains an auxiliary resin component which is capable of improving the surface smoothness of the cured paint films and which is a reaction product produced by reacting a t-alkylphenol novolac epoxy resin with an amount of an active hydrogen compound sufficient to open all epoxy rings. When the thus produced auxiliary resin has a hydroxyl group, reaction thereof with a lactone or alkylene oxide, to graft a soft segment to the auxiliary resin improves not only the surface smoothness but also the impact strength of the paint films.
In a cathodic electrodeposition paint composition comprising a primary cationically modified epoxy resin and a crosslinker dispersed in an aqueous medium containing a neutralizing acid, the improvement wherein Said epoxy resin is a bisphenol epoxy resin and wherein said paint comprises a cured film surface smoothness improving amount, from 0.5 to 30% of the combined weight of said primary resin and said cross-linker, of an auxiliary resin which is a reaction product produced either by reacting a t-alkylphenol novolac epoxy resin with an amount of a cationic active hydrogen compound or a non-cationic active compound sufficient to open all of the epoxy rings of said epoxy resin, or by first reacting said epoxy resin with an amount of said non-cationic active compound sufficient to open only a portion of said epoxy rings and then with an amount of said cationic active hydrogen compound sufficient to open the remaining epoxy rings.
In a cationic electrodeposition paint composition comprising a primary cationically modified epoxy resin and a crosslinker dispersed in an aqueous medium containing a neutralizing acid, the improvement wherein said epoxy resin is a bispphenol epoxy resin and wherein said paint comprises a cured film surface smoothness and impact strength improving amount, from 0.5 to 30% of the combined weight of said primary resin and said cross-linker of an auxiliary resin which is a reaction product produced by reacting a t-alkylphenol novolac epoxy resin first with an amount of an active hydrogen reactant capable of introducing a cationic group and a hydroxyl group sufficient to open all epoxy rings of said epoxy resin, and then with a lactone or alkylene oxide for grafting a soft segment to the hydroxyl group introduced to the resin molecule.
A cathodic electrodeposition paint composition comprising a primary cationically modified epoxy resin and a crosslinker dispersed in an aqueous medium containing a neutralizing acid, wherein said paint comprises a cured film surface smoothness improving amount, from 0.5 to 30% of the combined weight of said primary resin and said cross-linker, of an auxiliary resin and wherein (A) said epoxy resin is a bisphenol epoxy resin and the auxiliary resin is a reaction product produced either (a) by reacting a t-alkylphenol novolac epoxy resin with an amount of a cationic active hydrogen compound or a non-cationic active compound sufficient to open all of the epoxy rings of said epoxy resin, or (b) by first reacting said novolac epoxy resin with an amount of said non-cationic active compound sufficient to open only a portion of said epoxy rings and then with an amount of said cationic active hydrogen compound sufficient to open the remaining epoxy rings, or (B) said auxiliary resin is produced by first reacting a t-alkylphenol novolac epoxy resin with an amount sufficient to open all of said epoxy rings of an active hydrogen reactant capable of introducing a cationic group and a hydroxy group and then with a lactone or alkylene oxide which introduces a lactone or alkyhlene oxide for grafting a soft segment to the hydroxyl group introduced into the resin molecule.
Dependencies are inferred from the claim text.