Styrene-butadiene rubber with high styrene and vinyl content with narrow molecular weight distribution and procedures for its preparation

摘要

A polymer having at least the following characteristics: (a) a styrene block content with more than 6 consecutive styrene units of between 15 and 35 weight percent as measured in the description based on the content of total styrene in the polymer measured using 1H-NMR, following ISO 21561-2005 as indicated in the description; (b) a vinyl content of between 25 and 80 weight percent based on the total amount of polymerized 1,3-butadiene; (c) a styrene content of between 35 and 75 percent by weight based on the total weight of the polymer as measured in the description; and (d) a molecular weight distribution (Mw / Mn) of 1.5 or less measured using size exclusion chromatography based on the polystyrene standards, where the polymer is not according to Example 2 of EP2495267 A1.