【作者】 唐林生；

【导师】 杨锦宗； 张淑芬；

【作者基本信息】 大连理工大学 ， 应用化学， 2003， 博士

【摘要】 氨基丙烯酸漆是最重要的工业涂料之一，主要用于涂装汽车及轻工产品。随着我国汽车工业的迅速发展，其市场需求正在迅速增加。可是，传统的溶剂型氨基丙烯酸漆由于使用了大量的有机溶剂而造成了严重的环境污染和资源浪费。为此，国外十分重视该漆的水性化研究。国外早期开发出的氨基丙烯酸水溶胶漆(以羟基丙烯酸水溶胶为成膜树脂)具有良好的漆膜性能，但因施工性能差，有机挥发物含量仍较高，而仅用于涂装罐听外壁。后期开发的氨基丙烯酸乳胶漆(以羟基丙烯酸乳液为成膜树脂)具有良好的施工性，有机挥发物含量较低，但涂膜的平整性、光泽及耐水性较差。 本文对通过添加少量的羟基丙烯酸水溶胶来改善氨基丙烯酸乳胶漆的性能进行了研究。重点考查了水溶胶和乳液及颜料的相容性与乳胶漆性能的关系。实验结果表明：要获得良好的效果，水溶胶和乳液及颜料必须具有良好的相容性；当水溶胶聚合物的亲水性参数I／O为0.9～1.0，分子量Mw为5000～12000时，水溶胶和乳液及颜料的相容性良好；添加该水溶胶可改善氨基丙烯酸乳胶漆的光泽、耐水性和硬度。 探讨了水溶胶的作用机理。原子力显微镜图象证实，加入少量水溶胶能改善颜料在乳胶漆中的分散性，因而可改善乳胶涂膜的平整性和光泽，但乳胶涂膜的光泽不完全决定于颜料的分散及填充乳胶粒之间的孔隙，还与乳液聚合物的分子量有关。乳液聚合物分子量愈小，涂膜光泽愈好。水溶胶聚合物中的羧基对乳液和氨基树脂之间的交联反应具有催化作用。 为了解决氨基丙烯酸乳胶漆易起泡而在漆膜表面留下针孔的问题，提出了微皂乳液聚合的新思路。研究了水溶性羧酸类单体、磺酸类单体和非离子型单体对微皂乳液聚合的稳定化作用，水溶性单体的亲水性与稳定化作用及微皂乳液性能的关系。通过乳胶粒粒度分析及引发聚合速率的测定，探讨了微皂乳液聚合的成核机理。 通过与甲基丙烯酸或丙烯酸和N-羟甲基丙烯酰胺或丙烯酰胺共聚，实现了St-MMA-BA(或-HEA)的微皂乳液聚合，使乳化剂用量从常规乳液聚合的3.5～4.5wt.％降至0.05～0.20 wt.％(占单体的质量分数)，因而显著地降低了乳液的起泡性。该特性有利于解决乳胶漆因涂刷过程中起泡而使涂膜表面出现针孔的问题。 高性能氨基丙烯酸乳胶漆及相关理论研究 微皂乳液聚合的成核机理与常规乳液的相同，仍为胶束成核机理。微皂乳液聚合及产品的稳定性决定于水溶性单体在聚合后能否键合在乳胶粒表面，这取决于水溶性单体的亲水性。为了使水溶性单体键合在乳胶粒表面，水溶性单体的亲水性参数I/O应为3一5。 通过混入少量的轻基丙烯酸水溶胶和采用微皂乳液聚合制得的氨基丙烯酸乳胶漆，漆膜性能接近于水溶胶漆，施工性能良好，如涂膜干燥较快、不易，爆泡、粘度低、施工时的固含量较高，有机挥发物含量低和不易起泡等。更多还原

【Abstract】 Aminoacrylic coatings is of the most important industrial coatings for automobiles and light-industrial products. Its market demand is increasing because of rapid development of automobile industry at home. However, traditional solvent-based aminoacrylic formulations bring about serious environmental pollution and the waste of petroleum resources. Therefore, importance has been attached to developing waterborne coatings abroad. The original aminoacrylic hydrosol coatings have good film properties, but have some disadvantages relating operation property such as slow-drying and popping upon baking, and substantial levels of VOCs(volatile organic compound) . As a consequence, greater attention is being paid to aminoacrylic latex coatings. Although aminoacrylic latex coatings have advantages such as good operation property and lower VOCs emissions, it is difficult to obtain pore-free and glossy smooth film.In this paper, improving performance of the latex coatings by incorporating small amounts of hydroxyl acrylic hydrosols was studied. The relation of the compatibility of the hydrosols with the latexes as well as pigments and the properties of the coatings was investigated. To obtain good results, it is essential that the hydrosols must be compatible with the latex and pigments, which depends on the molecular weight and hydrophilicity of the hydrosol polymers. The hydrosol polymers with Mw of less than 13000 and hydrophilic parameter I/O of 0.9~1.0 are compatile with the latex and pigments. The gloss, hardness and water-resistance of the latex coatings can be improved by incorporating the hydrosols.The action mechanism of the hydrosols was discussed. AFM images confirm that well-designed hydrosols play an important role in dispersing pigments, which contributes to a smooth and glossy film, but the film gloss also relates to other factors such as the molecular weight of the latex polymers and filling of the vacant spaces among latex particles. The latexes with lower molecular weight tend to increase the film gloss. The carboxyl group in the hydrosol polymers has a marked catalysis for the crosslinking reaction between the latexes and amino-resins.5In order to reducing the foaming tendency of latex coatings, which bring about pinpricks on film surfaces, an emulsifier-minor emulsion polymerization technique was studied. The stabilization of water-soluble carboxylic monomers, sulfonic monomers and nonionic monomers, the relations of their hydrophilicity and their stabilization as well as properties of the emulsifier-minor latexes were investigated. The nucleation mechanism of the emulsifier-minor latex particles was discussed by measuring the particle size and the polymerization rate for the seeded stage.The emulsifier-minor emulsion polymerization of MMA-BA-St (or-HEA) can be achieved by the copolymerization with a combination of water-soluble methacrylic acid or acrylic acid and N-hydroxymethyl acrylamide or acrylamide, where the dosage of the emulsifier DSB can be reduced drastically from 35 45wt.% for conventional emulsion polymerization to 0.050.20 wt.% (based on all monomers ), then the foaming capacity of the latexes can be lowered markedly, which is very important to prevent some imperfections on the film surface risen from foaming during operation.The nucleation of the emulsifier-minor latex particles is mainly via micelle nucleation mechanism as same as in conventional emulsion polymerization. The stability of the emulsifier-minor emulsion polymerization and the final latexes depends on if water-soluble monomers can be bound to the particle surface after polymerization, which relies on the hydrophilicity of them. To fix water-soluble monomers on the particle surface, the hydrophilic index I/O of water-soluble monomers should preferably be 35.High performance aminoacrylic latex coatings can be prepared by incorporating small amounts of well-designed hydroxyl acrylic hydrosols and using the emulsifier-minor emulsion polymerization, which have not only good film properties, but also go更多还原