VULCANIZING RUBBER MIXTURE FOR FOOD PURPOSE Russian patent published in 1994 - IPC

FIELD: food industry. SUBSTANCE: vulcanizing rubber mixture has, g: cis-1,4-polyisoprene rubber 100; sulfur 2.3-2.5; zinc oxide 3-5; stearic acid 1-2; N-cyclohexyl-2-benzthiazolylsulfenamide 0.6-1.0; chalk 15-25; technical carbon with specific geometrical surface 96-105m²/g 35-45, and p-dimethylaminophenylphosphinic acid hydrochloride monohydrate of the gross formula C₈H₁₅ClNO₃P 0.3-0.5. Optimal vulcanization time at 151 C is 10 min, time before prevulcanization start at 120 C is 18-20 min. Rubber properties: conditional stretch strength is 17.5-18.0 MPa, relative rupture elongation is 475-535%, hardness is 63-65 conditional units, residual compression deformation for 20 days at 90 C is 63-66%. EFFECT: improved sanitary-chemical and toxicological properties at 100 and 110 C. 2 tbl