Development and Application of Low Fogging Values Silicone Sealant Luo Sibin, Zhang Ming, Deng Yumei低雾化值有机硅密封胶的研制及应用 罗思彬，张明，邓玉梅，黄强 （成都硅宝科技股份有限公司 四川成都 610041） 摘要：传统有机硅密封胶在耐候性、柔韧性和耐高低温冲击性等方面具有明显的优势，能够长时间承受180℃左右的高温，已经在车灯密封上得到广泛应用。但是传统有机硅密封胶应用在防雾灯具上时，会破坏防雾涂层的防雾性能，究其原因是基础聚合物中挥发出的 D3~D8等环状硅氧烷和小分子交联剂，凝结在防雾涂层表面，造成防雾涂层亲水性能下降。本文设计合成末端官能化的聚二甲基硅氧烷，以及开发了具有交联剂和偶联剂活性的大分子聚合物，进一步降低密封胶中的挥发份，制备得到的低雾化值有机硅密封胶雾化值≤500ug/g。该产品在防雾灯具的模拟应用测试结果证明防雾涂层的水接触角变化≤15°，不会影响车灯防雾性能；且已经在众多防雾车灯上得到广泛应用，效果良好。
关键词：低雾化值、防雾车灯、有机硅密封胶
Development and Application of Low Fogging Values Silicone Sealant Luo Sibin, Zhang Ming, Deng Yumei, Huang Qiang (Chengdu Guibao Science and Technology Co., Ltd., Chengdu 610041)
Abstract: Traditional silicone sealant has obvious advantages in weatherability, flexibility and impact resistance of high and low temperature, which can withstand high temperature of about 180 ℃ for a long time, and it has been widely used on automotive lighting sealing. However, when the traditional silicone sealant is applied to the anti-fogging lamps, it would destroy the anti-fogging performance of the anti-fogging coating. The reason is that the cyclic siloxane such as D3 ~ D8 and small molecule crosslinking agent volatilized from the base polymer would condense on the surface of the anti-fogging coating, resulting in the decrease of the hydrophilicity of the anti-fogging coating. In this paper, the chain-end modification polydimethylsiloxane was designed and synthesized, and the macromolecular polymer with the activity of crosslinking agent and coupling agent was developed to further reduce the volatile content in the sealant. The fogging value of the prepared silicone sealant with low Fogging Values was less than 500ug/g. The test results show that the change of water contact angle of anti-fogging coating ≤ 15 ° would not affect the anti-fogging performance of lamps, and it has been widely used on many anti-fogging automotive lighting with good effect. Key words: Low Fogging Values, Anti-fogging Automotive Lighting, Silicone Sealant |