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. 07, 1998
Filed:
Aug. 19, 1996
Arie Van Dongen, Amsterdam, NL;
Helmuth Einberger, Amsterdam, NL;
Jeroen Van Westrenen, Amsterdam, NL;
Shell Oil Company, Houston, TX (US);
Abstract
Process for manufacturing block copolymers derived from predominantly styrene and predominantly isoprene, used in the form of an isoprene concentrate obtainable by contacting an isoprene concentrate, obtainable by removal of piperylene from a gasoline pyrrolysis fraction of hydrocarbons having 5 carbon atoms, with finely dispersed alkali metal and/or alkaline earth metal, and separating it from the free and bound metal, said process comprising at least the steps of polymerizing predominantly styrene monomer in an inert non-aromatic hydrocarbon solvent in the presence of a monofunctional organolithium initiator, adding predominantly isoprene monomer in the form of pretreated isoprene concentrate to the polymerization mixture, either adding a coupling agent to couple a predominant part of the living diblock copolymer or adding a second portion of predominantly styrene monomer, and adding a terminating agent.