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:
Apr. 24, 2001
Filed:
Jan. 07, 2000
Harvey Emerson Atwood, Kingwood, TX (US);
Michael John Modic, Richmond, TX (US);
Barry Collins Moore, Cypress, TX (US);
John Louis Scheve, Marietta, OH (US);
Christine Marie Christian, Vincent, OH (US);
Shell Oil Company, Houston, TX (US);
Abstract
The present invention is a process for producing an anionic block polymer which comprises optionally anionically polymerizing styrene to form a homopolymer block of polystyrene, anionically polymerizing isoprene to form a hompolymer block of polyisoprene, and anionically copolymerizing styrene and isoprene to form a tapered copolymer block wherein the charge rate of both styrene and isoprene is from 15% to 75% by weight of the total tapered block monomer charge per minute and the weight ratio of the styrene to the isoprene is from 0.5:1 to 1.5:1. The process produces a unique polymer containing a tapered polymer block of styrene and isoprene which has a specific taper structure consisting of small segments of variable size of styrene monomers and isoprene monomers.