The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 16, 2014
Filed:
Jul. 07, 2009
Gregory Paul Dado, Chicago, IL (US);
Dale Lee Handlin, Jr., Houston, TX (US);
Carl Lesley Willis, Houston, TX (US);
Gregory Paul Dado, Chicago, IL (US);
Dale Lee Handlin, Jr., Houston, TX (US);
Carl Lesley Willis, Houston, TX (US);
Stepan Company, Northfield, IL (US);
Abstract
Improved methods for preparing sulfonated block polymers with acyl sulfates in non-halogenated aliphatic solvents are provided. The methods include the sulfonation of a precursor block polymer with an acyl sulfate in a reaction mixture further comprising at least one non-halogenated aliphatic solvent to form a sulfonated block polymer, wherein the initial concentration of the precursor block polymer is in the range of from about 0.1 wt % to a concentration that is below the limiting concentration of the precursor block polymer based on the total weight of the reaction mixture. A sulfonation degree of greater than about 1.0 milliequivalent sulfonic acid per gram sulfonated block polymer can be achieved substantially free of polymer precipitation and free of disabling gelation.