| abstract |
A novel rubbery polymer suitable for use in tire tread formulations is characterized in that the polymer comprises polymer particles which have from 2 to 6 domains, each domain comprising from 100 to about 40 weight percent of at least one C 4 to C 8 conjugated diolefin monomer, from 0 to about 60 weight percent of at least one C 3 3 to C 6 alkenyl nitrile monomer and from 0 to about 60 weight percent of at least one C 8 to C 12 monovinylidene aromatic monomer for a total of 100 weight percent of the domain, the monomer composition and/or molecular weight of one domain of each polymer particle differing from the monomer composition and/or molecular weight of each of the other domains of the polymer particle. A process for the production of the rubbery polymer is provided together with a rubber composition comprising the rubbery polymer and at least one diene-based polymer. |