| 摘要 |
PROBLEM TO BE SOLVED: To provide a rubber composition whose workability, mechanical strengths and durability have been improved so that it is suitable for making an extremely thick rubber product to be used as a support of bridge etc. SOLUTION: The rubber composition is produced by combining a 20 pts.wt. ethylene-vinyl acetate copolymer containing 80 wt% vinyl acetate, 10 pts.wt. mica whose weight average aspect ratio is 30 and weight average flake diameter is 40μm, 30 pts.wt. carbon black, 5 pts.wt. antioxidant, 1 pt.wt. stearic acid, 2.5 pts.wt. sulfur and 0.4 pt.wt. vulcanization accelerator to 100 pts.wt. natural rubber and by vulcanizing the mixture for 10 minutes at 150°C in order to adjust 100%M(kgf/cm<SP>2</SP>) to 24, tensile strength(kgf/cm<SP>2</SP>) to 202, elongation to 575%, durometer-A hardness to 66, shear storage modulus(kgf/cm<SP>2</SP>) to 8.2, tanδto 0.12 and -10°C/20°C G-ratio to 1.3. COPYRIGHT: (C)2004,JPO&NCIPI |
