RUBBER COMPOUND FOR MANUFACTURING UNCURED COILED ROOFING MATERIAL Russian patent published in 2000 - IPC

FIELD: manufacture of building materials. SUBSTANCE: compound is composed, wt. %: rubber crumb, 54-60; colloid silicic acid, 11-13; ethylene, (76-90)-vinyl acetate (24-10) copolymer, 9-11; and divinyl- styrene thermoelastolayer, 19-22. The latter is mixed with copolymer and rubber crumb for 3 min at 50 C in turbine mixer and, after treatment on rolls and on rubber mixer, silicic acid is added. Masticate is calendered at 85-90 C to yield material with conditional tensile strength of 5.0-5.2, relative elongation of 290-320%, of hardness 74-76 conv.un., and number of double bends 900-935. EFFECT: enhanced process efficiency. 2 tbl, 3 ex