一种高性能水性环氧丙烯酸外墙涂料的研究

Study on a High Performance Waterborne Epoxy Acrylic Exterior Paint

为获得一种具有较好耐候性及耐沾污性能的外墙涂料,研究开发了一种环氧丙烯酸外墙涂料,该外墙涂料采用的环氧丙烯酸乳液由核壳乳液聚合法制得,解决了传统纯环氧涂料耐候性差,不能作为外墙涂料使用的问题,又把环氧树脂硬度高,附着力好的优点与丙烯酸酯光泽度高、玻璃化温度可调的优点结合在一起。重点探讨了该外墙涂料的耐候性及耐沾污性能,又将由化学接枝共聚制得的环丙乳液的成膜过程与由物理共混制得的环丙乳液的成膜过程进行了比较。得出的结论是采用由核壳乳液聚合法制得的环氧丙烯酸乳液制备的环氧丙烯酸外墙涂料不仅耐候性好,还能提供优异于纯丙烯酸体系与苯丙体系的硬度与附着力,其清漆膜硬度为4H,附着力为1级,耐水168h无问题。该外墙涂料的PVC为45%时,其漆膜孔隙率低与反射率下降值低,说明此时漆膜具有较好的耐沾污性能,同时漆膜又较为致密。

In order to obtain an external coating having a good weather and stain resistance, an epoxy acrylic exterior paint was developed. The e- poxy acrylic emulsion was employed in this exterior paint which was prepared by core-shell emulsion polymerization method. It solved the problem that the traditional pure epoxy coating could not be used as an exterior paint for its poor weatherability. And it combined high hardness and good ad- hesion of epoxy resin with good glossiness and adjustable glass transition temperature of acrylate. The weather and stain resistance of this exterior paint were discussed. The comparison between two film forming processes was carried out, one epoxy acrylic emulsion was obtained by chemical graft- ing copolymerization and the other one was got by physical blending. It was concluded that the epoxy acrylic exterior paint would have a good weather resistance prepared with the epoxy acrylic emulsion which was synthesized by the core-shell emulsion polymerization, and it could provide a more ex- cellent hardness and adhesion than the pure acrylic and styrene-acrylic system provided. Its varnish film hardness was 4H, adhesion was level 1 and the waterproof ability was about 168h. When the PVC content of this exterior paint was 45%, the film had low porosity and low decline of reflectance, which meant that at this point the film had a good stain resistance and a dense film.