环氧丙烯酸树脂合成工艺对阴极电沉积涂膜外观的影响

Influence of synthetic technics of epoxy acrylic resin on the appearance of cathodic electrodeposition film

在110℃下、于一定溶剂中以偶氮二异丁腈和过氧化苯甲酰(BPO)为引发剂,引发由甲基丙烯酸甲酯、丙烯酸丁酯、甲基丙烯酸缩水甘油酯和甲基丙烯酸羟乙酯组成的反应体系,并以二乙醇胺为胺化剂、冰醋酸为中和剂合成了可用于阴极电沉积涂料的环氧丙烯酸阳离子树脂。研究了胺化温度、不同胺化工艺、不同醋酸中和工艺、中和温度以及不同pH值对电泳液粒径、电导率和阴极电沉积涂膜外观的影响。结果表明,选择胺化工艺Ⅱ,在90℃下胺化,同时选用冰醋酸在90℃下直接中和,当pH值为5.8左右时,所得的阴极电沉积涂料电泳液的外观呈乳白带蓝、电导率约为0.7ms/cm、槽液粒径约为95nm,所得涂膜厚度超过20μm,涂膜外观均匀、平滑。

At temperature of 110 ℃, the reaction system composed of methyl methacrylate, butyl acrylate, glycidyl methacrylate and hydroxyethacrylate was initiated by initiators of azobisisobutyronitrile and benzoperoxide in certain solvent. And the epoxy acrylic cationic resin applicable to cathodic electrodeposition coating was synthesized by using aminating agent of diethanolamine and neutralizing agent of acetic acid. The influences of aminating temperature, different aminating technicses and acetic acid neutralizing technicses, neutralizing temperature and varied pH values on particle′s diameter, conductivity of electrophoresis bath and appearance of films were studied. The results show that the appearance of electrophoresis bath of cathodic electrodeposition coating is milk-white and bluish, the conductivity is about 0.7 ms/cm and particle′s diameter is about 95 nm by opting aminating technics Ⅱ at 90 ℃ of aminating temperature and with glacial acetic acid direct neutralizing technics at neutralizing temperature of 90 ℃, bath pH value of about 5.8. The film′s thickness is more than 20 μm, and its appearance is even and uniform.