| 摘要 |
PURPOSE:To stably produce an elastomer having excellent physical properties even in a state compounded with a large amount of a softening agent by directly supplying a softening agent to a twin-screw extruder through a feeding port different from the feeding ports for a rubber component and a resin component and dynamically heat-treating the composition. CONSTITUTION:The objective composition is composed of (A) 20-80 pts.wt. of a powdery ethylene-propylene copolymer rubber and/or a powdery ethylene- propylene-non-conjugated diene copolymer rubber preferably having a bulk specific gravity of <=0.3, the maximum length of the major dimension of <=10mm or thereabout, the number-average of the major dimension of <=1mm and containing particles having major dimension of <=0.5mm accounting for >=90% of the total number of the particles, (B) 80-20 pts.wt. of a polyolefin resin and/or a modified polyolefin resin and (C) 5-200 pts.wt. (preferably 30-200 pts.wt.) of a softener based on 100 pts.wt. of the component A. The objective elastomer can be produced by directly supplying the component C from a feeding port different from those of the components A and B and dynamically heat-treating the components in the twin-screw extruder in the presence of a crosslinking agent, thereby crosslinking the component A. |
