Patent ID: 9145475
Filing Date: 2015-09-29
Classification: C08J

Abstract:
1. A method for producing a rubber composition containing 5 to 95 parts by weight of natural rubber (NR), 95 to 5 parts by weight of chloroprene rubber (CR) and 20 to 90 parts by weight of carbon black (CB), using a kneading machine, comprising a first step of producing a master batch (M1) containing NR and CB; a second step of producing a master batch (M2) containing CR and CB, and a third step of mixing the M1 and M2 with each other to produce a master batch (M3) containing NR, CR and CB; wherein when the total amount of CB in the rubber composition is regarded as 100% by weight, the amount of CB contained in the M2 is from 40 to 70% by weight, and when the M2 is discharged from the kneading machine after the second step, the actually measured temperature of the rubber composition is from 100 to 130° C.