水性封闭异氰酸酯乳液的合成及稳定性研究  

Study on Synthesis and Stability of the Waterborne Blocked Isocyanate Emulsion

作　　者：李阿峰[1] 樊国栋[1] 李会宁 陈华[1] 赵琪[1] 

机构地区：[1]陕西科技大学教育部轻化工助剂化学与技术重点实验室,西安710021 [2]肇庆千江高新材料科技有限公司,广东肇庆526238

出　　处：《涂料工业》2013年第2期18-22,共5页Paint & Coatings Industry

基　　金：陕西省科技攻关项目(2008K07-32);陕西省教育厅重点实验室重点科研计划项目(09JS061);陕西科技大学研究生创新基金资助

摘　　要：采用甲苯二异氰酸酯(TDI)、三羟甲基丙烷(TMP)、二羟甲基丙酸(DMPA)为原料,2-甲基咪唑为封闭剂,三乙胺为中和剂制备了水分散封闭异氰酸酯(WBI)乳液,考察了中和剂和Zeta电位(ζ-电位)对WBI乳液稳定性的影响,探讨了乳液耐电解质能力及其温敏特性对其解封温度及双组分聚氨酯漆膜性能的影响。实验结果表明:用三乙胺作为中和剂时,乳液粒径较小,稳定性及贮存稳定性均较好,最佳中和度为100%。随DMPA用量的增加,乳液的ζ电位绝对值增大,乳液粒径减小、耐电解质能力增强,乳液的稳定性提高。乳液的Zeta电位及粒径受温度影响较小,说明乳液较为稳定。DMPA用量为20%～25%(摩尔分数)较适宜。差示扫描量热法(DSC)分析表征其解封温度为125.6～138.1℃,应用表明此类WBI作为固化剂可以赋予涂料较好的耐水性、耐醇性、硬度及耐冲击性。Waterborne blocked isocyanate emulsion （WBI） was synthesized with toluene 2, 4 - diisocya- nate（ TDI）, trimethylolpropane （TMP）, dimethylol propionic acid （DMPA） as the reactants and 2 -meth- ylimidazole （2 - MI） as blocked agents and triethylamine as nentralizer. The influence of neutralizer and Ze- ta potential on stability of WBI emulsion was studied. The hydrolyte resistance and temperature dependence of emulsion and unblocking temperature of WBI and properties of two - component polyurethane film were discussed. The results showed that when triethylamine （TEA） was used as neutralizer, the emulsion provid- ed good stability and storage stability due to the small particle size. When the neutralization was up to 100% , the stability of emulsion was the best. With the increase of DMPA, the stability of the emulsion was improved. The Zeta potential and particle sized were less influenced by temperature. Suitable mole fraction of DMPA is 20% - 25%. The unblocking temperature was 125.6 ℃ to 137.8 % by DSC test. The WBI could be used as curing agent to provide better water resistance, alcohol resistance, hardness and impact proverties of coatings.

关 键 词：水分散封闭多异氰酸酯 ZETA电位 稳定性 二羟甲基丙酸 粒径 

分 类 号：TQ630.7[化学工程—精细化工]