聚乙二醇改性环氧丙烯酸阴极电泳涂料用乳液的制备

以聚醚多元醇改性环氧丙烯酸酯为主体树脂制备了阴极电泳涂料用乳液。讨论了聚醚多元醇的种类和用量对改性环氧丙烯酸乳液及其涂膜性能的影响,以及扩链反应温度和时间对环氧基转化率的影响。通过红外光谱(FT-IR)和热重分析(TG)对改性前后的环氧丙烯酸阳离子树脂进行了表征。试验发现,以PEG1000为扩链剂,用量为13%~14%,在90°C下反应4h,制得的改性环氧丙烯酸乳液平均粒径65.49nm,ζ电位58.3mV,乳液黏度0.21Pa.s,常温下放置300d未分层。改性后的阴极电泳涂料漆膜柔韧性为0.5mm,附着力0级,硬度2H,冲击强度50kg.cm,耐水性达到208h,性能明显优于改性前的漆膜。

Preparation of polyethylene glycol modified epoxyacrylic emulsion used for cathodic electrophoretic coating

An emulsion used for cathodic electrophoretic coating was prepared with polyether polyol-modified epoxy acrylate as main resin.The effects of the type and dosage of polyether polyol on the performance of modified epoxyacrylic emulsion and the film prepared thereby,as well as the effects of chain extending reaction temperature and time on the epoxy conversion rate were discussed.The epoxyacrylate cation resins before and after modification were characterized by FT-IR and thermogravimetric analysis.It was found that the modified epoxy-acrylate emulsion prepared with 13%-14% PEG1000 as a chain-extending agent at 90 °C for 4 h has an average particle size of 65.49 nm,Zeta potential 58.3 mV,and viscosity 0.21 Pa.s,and is stable without separation after placing at room temperature for 300 days.The film obtained from the modified cathodic electrophoretic coating features a flexibility 0.5 mm,adhesion strength 0 grade,pencil hardness 2H,impact strength 50 kg.cm,and water resistanceup to 208 h,showing better performance than the unmodified coating.