塑料涂料用脲基单体改性羟基苯丙乳液的合成

Synthesis of Hydroxyl Acrylic Emulsion Modified by Urea Monomer and Its Use in Plastic Paints

采用种子乳液半连续工艺法合成了脲基单体改性羟基苯丙乳液,与水性异氰酸酯固化剂配制得双组分水性塑料涂料,用于极性塑料基材的表面涂装。研究了乳化体系、羟基含量、交联单体乙烯基三乙氧基硅烷(AC-75)和脲基单体用量以及n(—NCO)∶n(—OH)比对乳液性能的影响。采用FT-IR、TEM和激光粒度仪等分析手段对苯丙乳液的形貌、粒径、表面官能团及涂膜固化过程进行了表征。结果表明:所制乳液呈现核壳结构、粒子的粒径分布较窄、固化反应完全,且脲基单体用量为2%,AC-75用量为3%,羟基单体用量为10%,n(—NCO)∶n(—OH)为1.3～1.5,可得到附着力、耐醇性、耐水性优异的涂膜,其性能优于市售溶剂型涂料。

The title urea monomer modified hydroxyl Stacrylic emulsion was synthesised via semi - continuous seed emulsion process, which was then mixed with water borne isocyanate curing agent to formu- late a 2K waterborne polyurethane coatings for polar plastic substrates. The effects of emulsification system, the content of hydroxye, crosslinking monomer AC - 75 and urea monomer and the mole ratio of NCO/OH on the properites of the modified emulsion were studied. The morphology and size of the modified emulsion were characterized by SEM and laser particle size analyzer. The structure, surface functional groups and curing process were characterized by FT- IR. The results showed that the styrene- acrylic emulsion had a core - shell structure with narrow size distribution. A film with better adhesion, alcohol resisdance and water resis- dance was obtained at the optimal conditions： urea monomer 2%, AC -75 3% ,OH 10%, the molar ratio of NCO/OH 1.3 to 1.5, which was better than the commereial products.