摘要
为了开发新型绿色环保金属表面前处理技术。以乙烯基聚硅氮烷树脂(OPZ118)和尼龙酸二甲酯配置前处理液,采用浸涂的方式将其涂覆在金属表面,180~230℃下烘烤即得聚硅氮烷转化膜。对前处理液的树脂固化反应机理、聚硅氮烷转化膜的基本性能以及与涂层的适配性进行了研究,结果表明:OPZ118树脂依靠双键交联固化后,其结构中依然富含Si-N活性基团;树脂固化物在去离子水中浸泡20 d,质量增加3.2%,去离子水pH由8升高到12;对浸泡后的树脂固化物进行红外光谱表征发现,N-H的弯曲振动和Si-NH-Si的伸缩振动峰强明显减弱,说明Si-N发生了水解反应;聚硅氮烷转化膜在3.5%NaCl溶液中浸泡72 h后,阻抗值稳定在6×10~7Ω·cm^2,说明转化膜具有优异的阻隔性;当钢板(Q235)表面形成的聚硅氮烷转化膜厚度为2μm时,钢板耐盐雾时间达72 h。金属表面涂覆聚硅氮烷转化膜后不影响环氧、氨基、有机硅等烘烤型涂层的附着力及耐冲击性。因此,聚硅氮烷转化膜不仅具有优异的防腐性能,而且与涂层适配性良好,具有广阔的应用前景。
In order to develop a new and green pretreatment technology for metal surface,the vinyl-containing polysilazane(OPZ118) and dimethyl butanedioate were used to prepare the pretreatment liquid.The OPZ118 resin solution was coated on metal surface by dipcoating process,and then baked at 180-230℃to form a polysilazane conversion film.The resin’ s curing reaction mechanism of the pretreatment liquid,the basic properties of the polysilazane conversion film,and the compatibility of polysilazane conversion film to different coatings were studied.The results showed that the obtained OPZ118 film was still rich in Si-N reactive groups after undergoing C=C addition reaction.The mass gain was 3.2% and the pH of the deionized water changed from 8 to 12 after the cured resin immersed in deionized water for 20 days.The peaks for N-H bending and Si-NH-Si stretching vibrations in FT-IR spectra decreased significantly after immersing treatment,indicating that the hydrolysis reaction of Si-N occurred.The impedance value was stable at 6×10~7 Ω·cm^2 after the film was immersed in 3.5% NaCl solution for 72 hours,indicating that the film has excellent barrier property.The thickness of the film for Q235 steel plate was 2 μm and steel plate’s salt spray resistance up to 72 h.When the coatings were applied to the surface,the polysilazane conversion film provided a good bonding effect,making coatings such as epoxy,amine and polysiloxane based paints have excellent adhesion and impact resistance.The polysilazane conversion film not only provide excellent corrosion resistance,but also the good compatibility,which indicates a promising future for the technology of polysilazane conversion film.
作者
邹铭
周晓龙
黄文文
徐彩虹
张宗波
Zou Ming;Zhou Xiaolong;Huang Wenwen;Xu Caihong;Zhang Zongbo(Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China;School of Chemistry and Chemical Engineering,University of Chemistry Academy of Sciences,Beijing 100049,China)
出处
《涂料工业》
CAS
CSCD
北大核心
2020年第4期19-25,共7页
Paint & Coatings Industry
关键词
前处理
聚硅氮烷
转化膜
阻隔
防腐性能
pretreatment
polysilazane
conversion film
barrier
corrosion resistance
