Patent ID: 7652105

Claim:
A method for producing a hydroxyl-modified ethylene-propylene-nonconjugated diene terpolymer, the method comprising: kneading 100 parts by weight of an ethylene-propylene-nonconjugated diene terpolymer having a Mooney viscosity of 10 to 250 at 100° C. and 0.1 to 20 parts by weight of a peroxide having a hydroperoxy group to prepare a kneaded mixture essentially containing the peroxide and the ethylene-propylene-nonconjugated diene terpolymer, wherein the peroxide has a 10-hour half-life temperature and a 1-minute half-life temperature; and heating the kneaded mixture essentially containing the peroxide and the ethylene-propylene-nonconjugated diene terpolymer at a temperature equal to or exceeding the 10-hour half-life temperature of the peroxide having a hydroperoxy group and not higher than the 1-minute half-life temperature of the peroxide having a hydroperoxy group to introduce hydroxyl groups into the ethylene-propylene-nonconjugated diene terpolymer via hydrogen abstraction.