| 摘要 |
PURPOSE:A high-melting, isotactic poly-alpha-olefin is dispersed in polyisoprene rubber in microparticles to produce the objective rubber composition showing the same level of tensile strength as conventional vulcanized rubber and improved elasticity, breakage properties and processability. CONSTITUTION:An isotactic poly-alpha-olefin melting at higher than 150 deg.C, preferably polypropylene, is dispersed in a rubber of polyisoprene (more than 90% cis-1,4- unit content) or a rubber mainly containing polyisopresene (more than 50%), preferably a diene rubber, into micro particles of less than 50 micron particle size on the average and the resultant mixture is drawn by the use of rollers in the temperature range from 65 deg.C lower than the melting point of the poly-alpha-olefin to 20 deg.C higher than the melting point. The drawn product is cooled to a usual processing temperature, additives are added, then they are kneaded, vulcanized and formed. When the content of the poly-alpha-olefin is 2-40wt%, preferably 3-25wt%, a vulcanized rubber of high elasticity, tearing resistance and flexural resistance is obtained. |
