降低水性双组分聚氨酯清漆起泡性的工艺优化  

Optimization study of foam control in waterborne polyurethane wood coating

作　　者：韦双颖[1,2] 刘雪铃 张彦华[1,2] 

机构地区：[1]东北林业大学材料科学与工程学院 [2]生物质材料科学与技术教育部重点实验室(东北林业大学),哈尔滨150040

出　　处：《林业工程学报》2017年第5期132-137,共6页Journal of Forestry Engineering

基　　金：中央高校基本科研业务费专项资金(2572017CB19);国家林业公益性行业科研专项(201504502);国家自然科学青年基金(312004400)

摘　　要：根据水性双组分聚氨酯(2K WPU)清漆的涂膜起泡来源,通过研究搅拌中心高度变化对预聚物分散效率、主副反应竞争程度及对实木基材表面润湿效果的影响,以优化2K WPU清漆低起泡性涂饰效果。研究结果表明:与搅拌中心始终位于反应体系体积中心的搅拌方式相比,搅拌中心高度由预聚物初始相界面处逐渐升高至反应体系体积中心处的搅拌方式,可有效提高预聚物分散效率,且促进主反应的进行、抑制副反应的发生;在该搅拌方式下共聚后,添加蒸馏水(质量分数2%~10%)、消泡剂Sago1710(质量分数2%)、润湿剂Sago3645(质量分数2%)后的涂料表面张力较小,与实木基材间的浸润功、黏附功和铺展系数较大;涂布量为0.5~1.0 kg/m^2涂装时,涂膜起泡性较低。According to the causes of foam in double-component waterborne polyurethane （2K WPU） wood coating, the effects of 2K WPU varnish were optimized through investigating the influence of the height variation of mixing center on the efficiency of the prepolymer dispersion, the competition degree between main and side effects, and the wet ability on the surface of solid wood. Based on the inhibition of CO2 gas produced during the preparation of coating and the increase of the ability of replacing the gas of solid wood base material surface with coating liquid, this re- search was carried out. Compared with poly hydroxy acrylic ester, the molecular weight of hexamethylene diisocyanate（HDI） is heavier, and the viscosity is higher. In the fixed center mixing dispersion system,there was the fixed center flow vortex motion, the fluid movement rate decreased with the increase of the distance to the center of the mixing place. The movement rate changed with radius is prone to cause the partial pressure of liquid inequality. Thus, the fixed center mixing mode is easier to cause scattered difference with the accumulation of mixing time and increased efficiency. This paper optimized the low blister effect of WPU wood coating. Compared with the mixing center located in the volume center of the reaction system, mixing center height increased at the initial phase interface to the middle of reaction system volume mixing way, which can effectively improve the efficiency of prepolymer dis- persion, promote the main reaction, and inhibit the occurrence of adverse events. After adding 2%-10% （mass per- cent） of distilled water and antifoaming agent Sago 1710 （2% mass percent） or wetting agent Sago 3645 （2% mass percent）, the coating surface tension decreased, and the infiltration between the solid wood base material work, adhe- sion work and the spreading coefficient were improved. When the coating weight was between 0. 5 and 1.0 kg/m2, coating foaming rate was lower.

关 键 词：水性聚氨酯清漆 低起泡性 工艺优化 消泡改性 

分 类 号：TQ639.8[化学工程—精细化工]