| 摘要 |
GR-S black rubber is prepared by the copolymerization of 64,4 parts of butadiene and 21,3 parts of styrene in 200 parts of an aqueous emulsion at 5 DEG C. containing a hydroperoxide catalyst, a Redox activator solution, a mercaptan modifier, a rosin soap emulsifier, a small amount of electrolyte, a sequestering agent and a dispersing agent. After 60% conversion of the monomers the reaction is terminated by the addition of a short stop solution containing sodium dimethyl dithiocarbamate. The latex solution is then heated and the unreacted butadiene flashed off and recovered while the unreacted styrene is steam-stripped and recovered. The stripped latex is then treated with 0,002 parts of p-tert.-butyl catechol as antioxidant and an emulsion containing 25 parts of an aromatic oil as oil extender and 50 parts of carbon black. The blended latex is then creamed with an aqueous solution of 10 parts of sodium chloride and coagulated with 2,05 parts of sulphuric acid in aqueous solution. After shredding the rubber crumb is classified as to size and a classified fraction of the particles is then dried.
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