| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high rigidity rubber material which can keep high rigidity even in a high temperature region, and has little temperature-dependency across a wide region from normal temperature to a high temperature. <P>SOLUTION: The high rigidity rubber material is an EPDM rubber composition which has a composition as shown below, has a Mooney viscosity of 70-100 at 100°C, and has the rigidity change rate represented by equation (1) as a vulcanized composition. The composition includes: 100 pts.wt. EPDM rubber, 135-180 pts.wt. carbon black, and 55-100 pts.wt. softening agent, wherein the ratio of carbon black/softening agent is 1.8-2.5, the blend amount excluding a vulcanizers and a sulfur compound is 300-400 pts.wt., and the total amount of sulfur is 1.0-2.8 pts.wt. Equation (1) is expressed by [(30% modulus at 100°C/30% modulus at 23°C)-1]×100%≥-10%. <P>COPYRIGHT: (C)2013,JPO&INPIT |
