摘要： 以低聚物多元醇、异佛尔酮二异氰酸酯(IPDI)为主要原料， 三羟甲基丙烷(TMP)为改性剂，合成了端羟基自乳化阳离子聚氨酯( PU) 树脂，再以封端型六亚甲基二异氰酸酯( HDI) 三聚体为交联剂，与其一同乳化制备电泳树脂，采用电泳工艺制备成膜。 用“原位 FT-IR”跟踪了交联剂的解封过程，研究了电泳涂料的固化过程。同时探究了TMP 的用量、交联剂与 PU 树脂的比例、交联剂的解封温度、电泳工艺参数对漆膜性能的影响。 结果表明:交联剂的解封温度为 100 °C ;TMP 在树脂中的质量分数为 0.50%，—NCO与—OH的物质的量比为 1.5 ∶1，80 °C 烘烤 30 min 后再在 140 °C 下烘烤1 h， 艺 电泳电压为 60 V 时，能得到表观和性能优异的漆膜。

关键词: 电泳涂料, 解封温度, 三羟甲基丙烷, 工艺参数, 漆膜

Abstract:

An cationic polyurethane PU) resin modified with trimethylolpropane( TMP) was synthesized from oligomer polyol, isophorone diisocyanate( IPDI)as raw materials via self-emulsifying method, and further reacted with blocked hexamethylene diisocyanate(HDI) trimer as cross-linking agent to form a film by electrophoresis process. The deblock process of waterborne polyurethane crosslinking agent was detected by in-situ FT-IR, meanwhile, the curing process of electrophoretic coatings was investigated. Effect of the dosage of TMP, molar ratio of resin to cross-linking agent deblock temperature of waterborne polyurethane crosslinking agent and process parameters on the appearance and properties of the film were investigated respectively. It was found that the desirable property and appearance for the film could be obtained under the conditions that the mass fraction of TMP was about 0.50%;the molar ratio of-NCO and-OH was 1 .5: 1; the deblock temperature of waterborne polyurethane crosslinking agent was 100 ℃; the baking temperature and time were 80 ℃/30 min,140℃/1 h; and the electrophoresis voltage was 60 V.

Key words: deblock temperature, trimethylolpropane, process parameters, film