车灯用脱醇型RTV-1有机硅密封胶的研制

摘要

Dealcoholized one component room temperature vulcanized ( RTV-1 ) silicone sealant for vehi-cle lamp was prepared with α,ω-dihydroxy polydimethylsiloxane , CaCO 3 , dimethyl silicone oil , cross-linking agent and other additives .Effects of the viscosity of PDMS , the average size and content of fillers , the content of crosslinker and the content and the types of coupling agent were studied .The preferred dealcoholized RTV-1 silicone sealant formulation is that with 107 silicone rubber of 60 ,000 mPa· s viscosity , 100 parts of CaCO 3 with an average size 80 nm, 3wt% cross-linking agent, 0.3wt% self-made urea-based coupling agent .The prepared dealcoholized RTV-1 silicone sealant has TFT of 12 min, extrusion rate of 165 mL/min, vulcanizing speed of 2.3 mm/(24 h), tensile strength of 2.26 MPa, elongation of 388%, shear strength of 1.74 MPa, good adhesive with PC and PP plasma-treated.It meets the requirements of the sealing and assembling of vehi-cle lamp.%以α,ω-二羟基聚二甲基硅氧烷(107硅橡胶)为基础聚合物,碳酸钙为填料,配以增塑剂、 交联剂等制得车灯用脱醇型单组分室温硫化(RTV-1)有机硅密封胶.研究了107硅橡胶黏度、 填料粒径和用量、 交联剂用量、 增粘剂种类和用量对密封胶性能的影响.结果表明,采用50份黏度60000 mPa·s的107硅橡胶,50份平均粒径80 nm的碳酸钙配成基胶,增塑剂用量(占基胶质量)5%,甲基三甲氧基硅烷3%,钛酸酯配合物1%,脲基增粘剂复合物用量0.3%条件下制备的密封胶性能较优,表干时间12 min,挤出速率165 mL/min,深层硫化速度2.3 mm/(24 h),拉伸强度2.26 MPa,拉断伸长率388%,剪切强度1.74 MPa,对聚碳酸酯和经等离子处理的聚丙烯粘接良好,适用于车灯的粘接密封.