Patent ID: 8383735

Claim:
A pre-cursor block copolymer for sulfonation which has the general configuration A-D-B-D-A, (A-D-B)nX, or mixtures thereof, where n is an integer from 2 to about 30, and X is a coupling agent residue and wherein: a. each A block is a polymer block resistant to sulfonation, each D block is a polymer block resistant to sulfonation, and each B block is a polymer block susceptible to sulfonation, said A, D and B blocks containing no significant levels of olefinic unsaturation; b. each A block independently having a number average molecular weight between 1,000 and 60,000, each D block independently having a number average molecular weight between 1,000 and 50,000, and each B block independently having a number average molecular weight between 10,000 and 300,000; c. each A block is a segment of one or more polymerized para-substituted styrene monomers; d. each B block comprises segments of one or more vinyl aromatic monomers selected from polymerized (i) unsubstituted styrene monomers, (ii) ortho-substituted styrene monomers, (iii) meta-substituted styrene monomers, (iv) alpha-methylstyrene, (v) 1,1-diphenylethylene, (vi) 1,2-diphenylethylene and (vii) mixtures thereof; e. each D block is selected from the group consisting of (i) a polymerized or copolymerized conjugated diene selected from isoprene, 1,3-butadiene having a vinyl content prior to hydrogenation of between 20 and 80 mol percent, (ii) a polymerized acrylate monomer, (iii) silicone polymer, (iv) polymerized isobutylene and (v) mixtures thereof, wherein the selected polymers have a glass transition temperature of less than 20° C. and a number average molecular weight of between 1000 and 50,000, wherein any segments containing polymerized 1,3-butadiene or isoprene are subsequently hydrogenated; and f. the mol percent of vinyl aromatic monomers which are unsubstituted styrene monomers, ortho-substituted styrene monomers, meta-substituted styrene monomers, alpha-methylstyrene, 1,1-diphenylethylene and 1,2-diphenylethylene in each B block is between 10 mol percent and 100 mol percent.