核壳乳液的制备及其在耐沾污外墙涂料中的应用

针对普通丙烯酸外墙乳胶涂料耐沾污性不足的缺陷,采用种子乳液聚合技术合成了内软外硬型丙烯酸酯核壳复合乳液和壳层含氟的丙烯酸酯核壳复合乳液.并采用自制乳液配制了外墙乳胶涂料,研究了核壳乳液对外墙涂料耐沾污性的影响.结果表明,与常规均相结构丙烯酸酯乳胶粒子相比,采用上述核壳乳胶粒子制备的外墙乳胶涂料耐沾污性得到大幅度提高.通过在壳层聚合时加入一定量的氟单体,核壳乳液涂膜的表面接触角和疏水性显著提高,漆膜吸水率明显降低,使得涂料的耐沾污性得到显著改善.由于氟组分主要分布于壳层,含量很少就可获得显著改性效果.

Preparation of core-shell emulsion and its application in improving stain resistance of exterior latex paint

In order to overcome the shortcoming of poor stain resistance of ordinary acrylic-based exterior latex paint,soft core/hard shell acrylic composite emulsion and core-shell acrylic composite emulsion with fluoropolymer rich in shell were synthesized by use of seed emulsion polymerization.In addition,exterior latex paint was prepared with the synthesized emulsion,and the influence of core-shell emulsion on the stain resistance of exterior latex paint was studied.The results show that,in comparison with general homogeneous acrylic latex,the stain resistance of exterior latex paint prepared with the core-shell acrylic latex is greatly increased.By adding a small amount of fluorine monomer during the polymerization of shell,the surface contact angle and hydrophobicity of core-shell emulsion film increase greatly,and the water adsorption ratio of paint film decreases evidently,as a result,the stain resistance of paint is significantly improved.Since the fluoropolymer is mainly contained in shell,great modification effect can be achieved with very low dosage.