填料对精密铸造模具硅橡胶使用寿命的影响

Effectof the Fillers on the Work Life of the Mold Making Silicone Rubber

以乙烯基硅油、白炭黑、无机疏水填料、含氢硅油、铂金催化剂、抑制剂等为原料,制得精密铸造模具硅橡胶。研究了填料种类、填料表面处理和填料配比对模具硅橡胶力学性能、存放稳定性、操作性能、尺寸稳定性和模具使用寿命的影响。较佳配方为:黏度5 000 m Pa·s的乙烯基硅油100份、气相法白炭黑15份、沉淀法白炭黑25份、经疏水处理无机填料30份。由此配方制得硅橡胶的力学性能满足模具要求,模具的线收缩率仅0.037%,耐溶剂溶胀性能优异,模具使用寿命与进口模具胶相当,存放1年后力学性能变化较小。

The mold making silicone rubber was prepared with vinyl silicone oil,silica,inorganic filler by hydrophobic treatment,methyl hydro-silicone oil,Pt catalyst and inhibiter as the basic materials. Effects of the filler types,surface treatment on the mechanical properties,storage stability,operating performance,dimensional stability and working life of mold making silicone rubber were studied. The preferred formulation was that 100 parts of vinyl silicone oil with the viscosity of 5000 m Pa·s,15 phr of fumed silica,25 phr of precipitated silica,30 phr of inorganic filler by hydrophobic treatment. The obtained mold making silicone rubber shows a good mechanical properties and long work life. The line shrinkage rate of the mold is only 0. 037%,with excellent solvent swelling resistance,whose mechanical performance changes little after 1 year.