| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject composition having excellent dynamic characteristics such as flexing resistance, etc., a long product life, by compounding a sulfur-modified chloroprene rubber with a vulcanization promoter, zinc oxide and magnesium oxide in mixed amounts to satisfy a specific relation. SOLUTION: This composition comprises (A) a sulfur-modified chloroprene rubber with (B) a vulcanization promoter, (C) zinc oxide and (D) magnesium oxide. The mixed amount M0 of the component B is 0.1-5 pts.wt. based on 100 pts.wt. of the component A. The mixed amount M1 of the component C and the mixed amount M2 of the component D are obtained by firstly preparing plural compositions composed of 100 pts.wt. of the component A, M0 pts.wt. of the component B and component C and the component D. When the mixed amount of the component B is m1 pts.wt. and the mixed amount of the component C is m2 pts.wt., coefficients A to F are experimentally determined by a relation of formula I [t(minute) is Mooney scorch time (t35 )] and then the values are determined by using a relation of formula II [t1 is a Mooney scorch time (t35 ) of a base blend 2A decided by ASTM 3190]. |
