METHOD FOR IMPROVING PHYSICAL AND CHEMICAL CHARACTERISTICS OF STYRENE-BUTADIENE RUBBER AND OBTAINED STYRENE-BUTADIENE RUBBER

摘要

PURPOSE: To improve physical and chemical properties by irradiating electron rays after molding a mixture of a styrene-butadiene copolymer compsn. Sulfur element, an accelerator and a crosslinking agent. ;CONSTITUTION: (A) A styrene-butadiene copolymer compsn., (B) 0.1-0.8 Phr of S, (C) 0-0.5 Phr of an accelerator, (D) 0.05-2 Phr of a multifunctional crosslinking agent (such as 3,9-divinyl-2,4,8,10-tetraoxyspiro-[5,5]-undecane), and if necessary, (E) carbon black, zinc oxide, stearic acid, an anti-ozone agent and an antioxidant, etc., are mixed to obtain a mixture. Then the mixture is introduced into a mold and kept at 138-160°C for 35-120 minutes, to mold a perform. Then, the perform is irradiated with electron rays of 10 MeV on the order of 5-25 Mrad, to obtain the objective rubber. The rubber has a minimum tear strength of 32.14 kg/cm (180 lbs./in.). It can be stored for more than 35 days without any sign of ozone corrosion based on a standard ozone test method [US ASTM-D-1149].;COPYRIGHT: (C)1989,JPO