低温烘烤型双组分水性聚氨酯涂料

采用溶液聚合法，合成了丙烯酸五元共聚物；将该共聚物中的羧基中和后制成丙烯酸多元醇分散体，将其作为B组分与一种低黏度的多异氰酸酯固化剂(A组分)组成双组分水性聚氨酯涂料。研究发现：引发剂含量、羟基含量、中和度以及A、B两组分混合搅拌方式都对双组分涂膜的性能产生重要影响。当引发剂含量为1％，羟基含量为2．7％，中和度为100％，A、B组分采用机械搅拌混合时所得的涂膜综合性能最好。水性涂料的适用期达到8h，超过相应的溶剂型涂料。

2 K Low Temperature Baking Aqueous Polyurethane Coatings

A pentabasic acrylic copolymer has been prepared by solution polymerization.The carboxylic group in the copolymer is neutralized to form an acrylic polyol dispersion,which is used as component B to react with a low viscosity isocyanate (component A) forming the title 2K aqueous polyurethane coatings.It has shown that the amount of initiator,hydroxyl value,neutralization degree and the mixing approaches of Component A anb B will impart an important effect on the coating film properties.It is found that the coating film will provide the best all round performance when the amount of initiator is 1%,hydroxyl content 2.7%,carboxyl group is fully neutralized,and mechanical mixing approach is used.The pot life is up to 8 h ,which is longer than the similar solvent-based coatings.