Styrene butadiene copolymer in primary form.    This copolymer is manufactured by mixing styrene butadiene rubber latex (SBR) with high styrene content resin.    The final product consists of a mixture of styrene butadiene copolymers with a proportion of styrene of 65 % by weight or more.  ,3903 90 90,  Classification is determined by General Rules 1 and 6 for the interpretation of the Combined Nomenclature, Notes 1, 4 and 6 to Chapter 39, Note 4 (a) and 4 (c) to Chapter 40, subheading Note 1 to Chapter 39 and the wording of CN codes 3903, 3903 90 and 3903 90 90.    Styrene butadiene copolymers with a proportion of styrene of 65 % by weight or more do not comply with the definition of synthetic rubbers referred to in Note 4 (a) to Chapter 40 since once these products are vulcanised with sulphur, they do not fulfil the elongation and recovery requirements indicated in that Note.    Therefore the product is to be classified under CN code 3903 90 90 as other styrene polymers.  ,