Patent ID: 7923518
Filing Date: 2011-04-12
Classification: C08C,C08F,C08K,C08L

Abstract:
1. A nitrile rubber which contains repeating units of at least one α,β-unsaturated nitrile and, at least one conjugated diene and (i) has a calcium content of 150 ppm to 1290 ppm, based on the nitrile rubber, and a chlorine content of at least 40 ppm, based on the nitrile rubber, and (ii) contains 2,2,4,6,6-pentamethylheptane-4-thio, 2,4,4,6,6-pentamethylheptane-2-thio, 2,3,4,6,6-pentamethylheptane-2-thio and 2,3,4,6,6-pentamethylheptane-3-thio end groups, wherein the nitrile rubber has a storage stability of not more than 3 Mooney units, said storage stability calculated by the formula (I), where MV1 is the Mooney viscosity of the nitrile rubber and MV2 is the Mooney viscosity of the same nitrile rubber after storage at 100 ° C. for 48 hours.