Process for the preparation of in situ dispersion of copolymers
AssigneeBridgestone Corporation
InventorJames E. Hall
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Abstract
The present invention relates to a process for the dispersion copolymerization of 35 to 70% by weight of vinyl substituted aromatic monomer and 30 to 65% by weight of conjugated diene monomer comprising carrying out the copolymerization in a reaction mixture containing a liquid aliphatic hydrocarbon dispersing medium, an anionic catalyst system, and an "A" block of a copolymer dispersing agent, the dispersing agent having at least two polymer blocks wherein at least one of the polymer blocks is soluble in the dispersing medium and at least another of the polymer blocks is insoluble in the dispersing medium and is formed in situ.
Claims14
A process for the preparation of a dispersion copolymer by the dispersion copolymerization of 35 to 70% by weight of a vinyl aromatic monomer and 30 to 65% by weight of a conjugated diene monomer comprising carrying out the copolymerization in a hydrocarbon dispersing medium in the presence of a block copolymer dispersing agent having a preformed block and at least one block formed in situ during the copolymerization of the dispersion copolymer and a catalytically effective amount of an anionic initiator, the preformed block being soluble in the dispersing medium and the block formed in situ being insoluble in the dispersing medium.
Dependencies are inferred from the claim text.