摘要
在含纳米Si O2的乙醇溶液中分别令乙烯基三乙氧基硅烷(KH-151)、N-(β-氨乙基)-γ-氨丙基三甲氧基硅烷(KH-792)、γ-氨丙基三乙氧基硅烷(KH-550)、γ-(2,3-环氧丙氧)丙基三甲氧基硅烷(KH-560)、甲基三甲氧基硅烷(MTMS)水解,然后与不饱和聚酯改性丙烯酸树脂乳液混合,制备了几种硅烷偶联剂/树脂复合钝化液,再涂抹于热浸镀锌钢板上。通过中性盐雾试验、醋酸铅点滴腐蚀试验测其耐蚀性,采用扫描电镜和能谱仪分析膜层的微观结构与元素组成,利用极化曲线和电化学阻抗谱研究其耐蚀机理,并考察了钝化液的室温贮存稳定性,以及钝化膜与环氧底漆/聚氨酯面漆体系的配套性能。结果显示,KH-151/树脂复合钝化液在室温下至少能放置12 d,其所制备的钝化膜表面平整,中性盐雾试验72 h之后的腐蚀面积小于5%,耐醋酸铅点滴腐蚀时间长达7 200 s,与后续漆膜的配套性能可达到含铬钝化膜的水平。
Vinyltriethoxysilane （KH-151）, N-（2-aminoethyl）-3-aminopropyltrimethoxysilane （KH-792）, 3-aminopropyl- triethoxysilane （KH-550）, 3-glycidoxypropyltrimethoxysilane （KH-560） and methyltrimethoxysilane （MTMS） were separately hydrolyzed by being added to an ethanol solution containing nano-SiO2. The resulting hydrolysates were then mixed with unsaturated polyester-modified acrylic resin emulsion to prepare several coupling agent/resin composite passivation solutions, which were then coated on hot-dip galvanized steel sheets. The corrosion resistance of the passivated hot-dip galvanized steel sheets was tested by neutral salt spray test and lead acetate dropping corrosion test. The microstructures and elemental compositions of the passivation films were analyzed by scanning electron microscope and energy-dispersive spectrometer. The anticorrosion mechanism was studied by polarization curve measurement and electrochemical impedance spectroscopy. The stability of the passivation solutions during storage at room temperature and the overcoatability of the passivation films with an epoxy primer/polyurethane topcoat system were examined. The results showed that the KH-151/resin composite passivation solution can be stored at room temperature for at least 12 days and the film obtained therefrom features the following properties： smooth surface, corrosion area less than 5% after neutral salt spray test for 72 h, time to endure lead acetate dropping corrosion up to 7 200 s, and good overcoatability similar to a chromate passivation film.
作者
张琪
伍林
童坤
李泽亚
刘盈
张军锋
舒沙沙
柳家明
饶文昊
ZHANG Qi Wu Lin TONG Kun LI Ze-ya LIU Ying ZHANG Jun-feng SHU Sha-sha LIU Jia-ming RAO Wen-hao(Applied Chemistry Research Institute, Wuhan University of Science and Technology, Wuhan 430081, China)
出处
《电镀与涂饰》
CAS
CSCD
北大核心
2017年第20期1075-1080,共6页
Electroplating & Finishing
关键词
热镀锌钢板
硅烷偶联剂
不饱和聚酯改性丙烯酸树脂
无铬钝化
贮存稳定性
耐蚀性
漆膜配套性
hot-dip galvanized steel sheet
silane coupling agent
unsaturated polyester-modified acrylic resin
chromate-free passivation
storage stability
corrosion resistance
overcoatability
