METHOD FOR PREPARING CONJUGATED DIENE COPOLYMER CONJUGATED DIENE COPOLYMER BY PREPARED THE METHOD AND RUBBER COMPOSITION COMPRISING THE COPOLYMER

摘要

The purpose of the present invention is to provide a method of preparing a conjugated diene-based copolymer, which can improve abrasion resistance and viscoelastic properties of a rubber composition comprising a conjugated diene-based copolymer prepared by emulsion polymerization. According to the present invention, the method comprises a step (S10) of performing an emulsion polymerization process of an α-methyl styrene monomer, a conjugated diene-based monomer and a hydroxy alkyl (meth)acrylate monomer, wherein the α-methyl styrene monomer and the conjugated diene-based monomer are added in a batch manner at a time when the emulsion polymerization process has a polymerization conversion ratio of 0%, the hydroxy alkyl (meth)acrylate monomer is separately added over two or more steps at a time when the emulsion polymerization process has a polymerization conversion ratio of 0 to 80%, and 10 to 50 wt% of the α-methyl styrene monomer, 49 to 89 wt% of the conjugated diene-based monomer, and 0.1 to 5 wt% of the hydroxy alkyl (meth)acrylate monomer are added with respect to the total content of the monomers. The present invention also provides a conjugated diene-based copolymer prepared by the method, and a rubber composition comprising the conjugated diene-based copolymer.