阴极电泳涂料用高固体分丙烯酸树脂的合成

采用甲基丙烯酸异冰片酯(IBOMA)、甲基丙烯酸二甲胺乙酯(DMAEMA)等(甲基)丙烯酸酯类单体合成阴极电泳涂料用高固体分自交联型丙烯酸树脂。研究发现,引入低表面张力、带非极性多环酯基的IBOMA可降低树脂的黏度,提高合成树脂的固体质量分数到75%甚至更高;当单体的滴加时间控制在3～3 5h,采用m(偶氮二异丁腈)∶m(过氧化苯甲酸叔戊酯)=1∶(0 3～0 5)的混合引发剂,w(混合引发剂)=2%～4%时,能获得相对分子质量大小及分布适宜的水溶性高固体分自交联聚合物;研究聚合物水溶性和涂膜交联性的影响因素发现,w(DMAEMA)=16%、w(甲基丙烯酸羟乙酯)=15%、w(N 丁氧甲基丙烯酰胺)=6%时,树脂的水溶性较佳,涂膜的交联度可达90%;引入了丙烯酸作为共聚物自交联的潜催化剂,差示扫描式量热法(DSC)分析表明,w(丙烯酸)=1%时,可显著降低树脂的固化反应温度。

Synthesis of High Solid Acrylate Resin for Cathodic Electrodeposition Coating

Self-crosslinked acrylic resin for cathodic electrodeposition coating with high solids was synthesized by copolymerization of isobornyl methacrylate(IBOMA),dimethylaminoethyl methacrylate(DMAEMA),hydroxyethyl methacrylate(HEMA),etc.It was found that the viscosity of the acrylic resin decreased and the solid content increased up to 75%( wt ) by using IBOMA.This phenomenon may be explained from the IBOMA characterization of nonpolar polycyclic ester group and low surface tension.Waterborne high solid resin with appropriate molecular weight and distribution was gained by controlling the monomer feeding time in 3～3.5 h,and using 2%～4%( wt ) of the composite initiator of azoisobutyronitrile and tert -amyl peroxy-benzoate in mass ratio of 1∶ (0.3～0.5).The performance study showed that the prepared resin is well water-soluble,and that the crosslinking degree of coating can reach 90% when w (DMAEMA), w (HEMA) and w ( N -butoxymethyl-acrylamide) are 16%,15% and 6% respectively.Acrylic acid was introduced as the potential catalyst,and DSC analysis showed that when its level is 1%( wt ) the crosslinking reaction temperature of the resin can be decreased.