A cathodic electrodeposition paint containing a cationically modified epoxy resin and a crosslinker dispersed in an acidic aqueous medium is disclosed. The paint contains an auxiliary resin component capable of improving the surface smoothness of the cured paint films. The auxiliary resin is a reaction product produced by reacting a t-alkylphenol novolac epoxy resin with an active hydrogen compound to open all epoxy rings. When the auxiliary resin has a hydroxyl group introduced by the reaction with the active hydrogen compound, a lactone or alkylene oxide is addition reacted with the hydroxyl group for grafting a soft segment to the auxiliary resin. By grafting a soft segment, the auxiliary resin improves not only the surface smoothness but also the impact strength of the paint films.
                            本发明公开了一种阴极电沉积涂料,它含有阳离子改性环氧
树脂和分散在酸性
水介质中的
交联剂。该涂料含有一种辅助
树脂成分,能够提高固化漆膜的表面平滑度。该辅助
树脂是一种反应产物,通过使 t-烷基
酚新戊酸环氧
树脂与活性氢化合物反应,打开所有环氧环而产生。当辅助
树脂通过与活性氢化合物反应引入羟基时,内酯或环氧亚烷基会与羟基发生加成反应,从而在辅助
树脂上接枝软段。通过接枝软段,辅助
树脂不仅能提高漆膜的表面平滑度,还能提高漆膜的抗冲击强度。