新型水性环氧富锌涂料的制备及性能研究

Study onthe Preparation and Performance of Novel Waterborne Epoxy Zinc-Rich Coating

为了满足重防腐蚀领域对涂料耐久性的需要,通过调节环氧富锌涂料中锌粉的比例、添加硅烷偶联剂、优化涂料防沉体系,制备了耐腐蚀性能强、储存稳定性高的水性环氧富锌底漆。研究了该涂料中锌粉、偶联剂、防沉剂3种组分对涂层耐腐蚀性能、附着力及储存稳定性的影响,并将该涂层与环氧中间漆、水性聚氨酯防腐蚀面漆组成了复合涂层体系,分析测试了复合涂层体系的耐中性盐雾腐蚀性能及附着力。结果表明:制备水性环氧富锌底漆的过程中,控制有机膨润土和亲油性气相二氧化硅的含量可提高涂料的储存稳定性,其中锌粉加入量为55.0%(质量分数,下同),防沉剂有机膨润土和气相二氧化硅含量分别为0.8%和1.0%时,涂料的储存稳定性可达10级;硅烷偶联剂加入量为1.5%时,涂层与基体间的结合强度可达到11.3 MPa;该涂料作为底漆与环氧中间漆、水性聚氨酯面漆组成的复合涂层体系,在经过3600 h中性盐雾试验后不剥落,可用于重防腐蚀领域。

In order to meet the requirement of durability in the field of heavy anti-corrosion coating,a waterborne epoxy zinc-rich primer with strong corrosion resistance and high storage stability was prepared by adjusting the proportion of zinc powder in the epoxy zinc-rich coating,adding silane coupling agent and optimizing the coating anti-settling system.The effects of the three components of zinc powder,coupling agent and anti-settling agent on the corrosion resistance,adhesion to the substrate and storage stability were studied systematically.In addition,the prepared coating was combined with epoxy intermediate coating and waterborne polyurethane to constitute a complex coating system,and their neutral salt spray(NSS)corrosion resistance and adhesion of the system were analyzed.Results showed that during the preparation process of epoxy zinc-rich primer,controlling the content of organic bentonite and lipophilic fumed silica could improve the storage stability of the coating.When the amount of zinc powder was 55%(mass fraction,the same below),the contents of anti-settling agent,organic bentonite and fumed silica are 0.8%and 1.0%respectively,the storage stability of the as-obtained coating could reach grade 10;when the content of silane coupling agent was 1.5%,the bonding strength between the coating and the substrate could reach 11.3 MPa.The coating could act as primer then form a composite coating system with epoxy intermediate coating and water-based polyurethane top-coating,which withstood 3600 h NSS corrosion test without peeling,inducing that the coating system could be promisingly used in the field of heavy corrosion protection.