METHOD OF PRODUCING RUBBER MIXTURE FOR MAKING CAR TYRES Russian patent published in 2013 - IPC C08J3/20 C08L21/00 B01F5/08 

FIELD: chemistry.

SUBSTANCE: rubber mixture is prepared in a rubber mixer in two steps. The first step involves feeding unsaturated rubber, technical carbon, softening agents, protective wax, N-isopropyl-N'-phenyl-n-phenylenediamine, polymerised 2,2,4-trimethyl-1,2-dihydroquinoline, N-cyclohexyl thiophthalimide, zinc oxide, stearic and oleic acid, after which the ingredients are mixed at 80°C for 4-5 minutes with rotor speed of 60 rpm. The second step involves feeding vulcanisation accelerators and mixing at 60°C for 2-3 minutes at rotor speed of 30 rpm. The obtained rubber mixture is subjected to low-frequency mechanical vibrations and then passed through a cascade of series-connected dispersers, after which the treated mixture is vulcanised. Each cascade consists of 2-3 dispersers in form of de Laval nozzles. Pressure drop at each disperser on each cascade is equal to 250000-350000 Pa. The mixture is fed through cascades of dispersers by a pump and the pumping pressure is greater than the total pressure drop at the cascades by 1.2-1.5 times. Sulphur is fed into the critical part of the nozzle of the first disperser of the first cascade, and the mixture in the critical part of the nozzle is accelerated to speed of 8-10 m/s.

EFFECT: invention enables to increase uniformity of distribution of components while improving physical and mechanical properties.