紫外光固化阴极电泳涂料用丙烯酸树脂的合成及应用

Synthesis and application of acrylic resin for UV-curable cathodic electrophoretic coating

以甲基丙烯酸二甲胺乙酯(DMAEMA)、甲基丙烯酸羟乙酯(HEMA)、丙烯酸异辛酯(EHA)、甲基丙烯酸甲酯(MMA)和苯乙烯(St)为共聚单体制备了阳离子型丙烯酸树脂,再利用含异氰酸根的不饱和单体对其进行接枝改性得到光敏树脂,合成了紫外光(UV)固化阴极电泳涂料。红外光谱表征证明得到了目标产物。考察了电泳工艺对漆膜厚度、闪蒸条件对漆膜性能以及光固化条件对双键转化率的影响,获得了最佳电泳工艺为、闪蒸工艺和固化条件,分别为:电泳电压80V,电泳时间90s;闪蒸温度80°C,闪蒸时间5min;引发剂用量3%(质量分数),固化时间70s。此条件下固化所得漆膜平整、光亮,性能优异。

A cationic urethane acrylic resin applied to UVcurable cathodic electrophoretic coatings was prepared, in which the cationic acrylic resin was synthesized via free radical copolymerization with 2-（dimethylamino）ethyl methacrylate （DMAEMA）, 2-hydroxyethyl methacrylate （HEMA）, 2-ethylhexyl acrylate （EHA）, methyl methacrylate （MMA） and styrene, and the copolymer was modified with a prepolymer of isocyanato-containing unsaturated monomer to obtain a photosensitive urethane acrylate. The FTIR characterization revealed that the target product was obtained. The effects of electrophoresis process on coating thickness, flashing conditions on coating properties and curing conditions on double bond conversion rate were studied. The optimal process conditions were determined as follows： electrophoresis at 80 V for 90 s; flashing at 80 ℃ for 5 min; curing with 3% （mass fraction） initiator for 70 s. The film obtained under the optimal conditions has a smooth and bright appearance as well as good performance.