Technology

The starting materials, Styrene and Butadiene, are dispersed in Water using an emulsifier, and a radical initiator, generally a redox catalyst, is dispersed in water. In order to facilitate decomposition of the peroxide, a reducing agent is added. A chain transfer agent is added. Polymerization is carried out in oil droplets. After reaching 60% monomer conversion the Emulsion SBR product is collected. Anti-aging agents and, if necessary, extender oil are added, and the product is sent to the coagulation process. In order to remove the emulsifier from the system, the crumbs are washed with water and sent to the drying process. In the drying process the crumbs are squeezed-dried in a dryer. After drying, the crumbs are weighed by an automatic weigher and then formed into blocks. After the blocks are collected, they are checked with a metal detector to ensure that no metal is mixed in, and the product is packed.

Source: Yutaka NAGATA, 13^th Mar 2015, Industrial Synthetic Method of the Rubbers - 3. Styrene Butadiene Rubber, The Society of Rubber Science and Technology, Japan.