VAc/Veova型可再分散性乳胶粉的工艺条件研究

以聚乙烯醇(PVA)为保护胶体、过硫酸铵(APS)为引发剂、醋酸乙烯(VAc)和改性单体(Veova)为主要原料,采用种子乳液聚合法制备VAc/Veova乳液;然后以此为母液,采用喷雾干燥法制备可再分散性乳胶粉。结果表明:当保护胶体选择低聚合度不完全皂化的PVA、采用连续滴加法加入引发剂、采用前混工艺加入抗结块剂、干燥塔进口温度为150～200℃和出口温度为80～90℃时,VAc/Veova型可再分散性乳胶粉的主要应用性能满足JG 149—2003标准,并且接近甚至超过国内外同类产品。

Study on process conditions of VAc/Veova re-dispersible latex powder

With polyvinyl alcohol(PVA) as protective colloid,ammonium persulfate(APS) as initiator,vinyl acetate(VAc) and modified monomer(Veova) as main raw materials,the VAc/Veova emulsion was prepared by seed emulsion polymerization.Then the re-dispersible latex powder was prepared by spraying drying method with VAc/Veova emulsion as matrix emulsion.The results showed that the main application properties of VAc/Veova re-dispersible latex powder could meet JG 149—2003 standard,and could approach or exceed the application properties of congeneric products at home and abroad when the protective colloid was a PVA based on incomplete saponification with lower polymerization degree,the initiator was introduced into the system by continuous dropping process,the caking inhibitor was introduced into the system by pre-mixing process,the inlet temperature and outlet temperature of the drying tower were 150-200 ℃ and 80-90 ℃ respectively.