abstract |
PROBLEM TO BE SOLVED: To provide a carboxylated nitrile group-containing highly saturated copolymer rubber excellent in tensile strength and abrasion resistance, having high adhesion to fibers, and hardly scorching, and a method suitable for producing the same. provide. SOLUTION: A nitrile group-containing highly saturated polymer rubber is masticated using a pressure kneader mixing amount of 75 liters, MS type), and after the rubber temperature rises to 130 ° C., 1.8 parts of maleic anhydride and 2,6-di-tert-butyl-4- 0.5 part of methyl phenol (BHT) is charged into a pressure kneader, kneaded (pre-kneaded), and the rubber temperature is adjusted to 250 ° C. by utilizing the shear heat generated by the kneading. The mixture was further kneaded for 15 minutes to cause an ene-type addition reaction, and an acid equivalent of 1.63 × 10 −2 e. phr, the value of [carboxylic acid anhydride group peak height] / ([carboxylic acid anhydride group peak height] + [carboxyl group peak height]) in infrared absorption analysis was 0.96, Mooney viscosity 65, iodine value 28, methyl ethyl ketone A highly saturated copolymer rubber containing a carboxylated nitrile group having an insoluble content of 0.2% was obtained. |