车载激光雷达用有机硅RTV密封胶的化学负荷兼容性研究

Study on chemical load compatibility of silicone RTV sealant for vehicle LiDAR

激光雷达所处车载环境会接触大量油脂类溶剂,故将有机硅RTV密封胶与该环境下的常见溶剂进行兼容性试验,研究了不同配方体系在浸泡老化后各项性能的耐受度。研究结果表明:由于交联密度普遍低于聚氨酯、环氧等,有机硅RTV密封胶应做特殊配方设计,以减轻油脂对体系的溶胀效应;同时应参考ISO 16750-5—2018标准中的规定,在不同溶剂、不同温度下,进行不同程度的浸泡以评估其老化状况。耐油型有机硅RTV密封胶的填料体系应尽量选择CaCO等低吸油值或改性为憎油型的体系,以减缓油分子渗入,并谨慎采用气相白炭黑填料。在不考虑硫化后释放出的丁酮肟气味、对金属铜的腐蚀或溶胀聚碳酸酯(PC)等风险的条件下,应优先选择高交联密度的脱肟型配方设计。

The vehicle environment where the LiDAR is located will be exposed to a large amount of grease solvents. Therefore,the compatibility test of silicone RTV sealant and common solvents in this environment was carried out to study the tolerance of various properties of different formulation systems after immersing and aging.The research results showed that since the crosslinking density was generally lower than that of polyurethane and epoxy,the silicone RTV sealant should be specially formulated to reduce the swelling effect of grease on the system.At the same time,according to the provisions of ISO 16750-5—2018 standard,different degrees of immersion in different solvents and at different temperatures were carried out to evaluate the aging condition. The filler system of oil-resistant silicone RTV sealant should try to choose a system with low oil absorption value such as CaCOor modify to lipophobic system to slow down the infiltration of oil molecules,and fumed silica filler should be cautiously used. Under the condition of not considering the risk of butanone oxime odor released after vulcanization,corrosion to metallic copper,or swelling polycarbonate(PC),the formula design of de-ketoxime formulation with high crosslinking density should be preferentially selected.