Shell Oil Comapny

Kraton Polymers U.S. LLC

Exxon Chemical Patents, Inc.

Harvey E Atwood

Carl Lesley Willis

Robert Charles Bening

Robert B Rhodes

Dale Lee Handlin, Jr

Kimberly Ann Johnson

Daniel Earl Goodwin

Craig A Stevens

Pierre Nazareth Tutunjian

Adrie A Van Der Huizen

Grant W Haddix

Mark Hageman

Joy P Cocchiara

Ronald J Hoxmeier

Michael John Modic

John E Gorman

Arthur R Bean

Barry B Moore

Raymond C Tsiang

Nikolaas Jan Van Dijk

Christine Marie Christian

John Louis Scheve

Barry Collins Moore

Adriana Maria Petronella Ros

Marinus Pieter Van Dijk

Gary W Richie, Deceased

Daniel E Goodwin

Pierre N Tutunjian

Lithium-terminated polymers of one or more conjugated dienes and of one or more mono alkenyl arenes are coupled by reaction with an alkoxy silane coupling agent having the formula R&#x2014;Si&#x2014;(OR'), where x is 0 or 1, x+y=4, R and R&#x2032; are the same or different, R is selected from aryl hydrocarbon radicals, linear alkyl hydrocarbon radicals and branched alkyl hydrocarbon radicals, and R&#x2032; is selected from linear and branched alkyl hydrocarbon radicals, such that the resulting polymer composition contains less than about ten weight percent of uncoupled polymer diblock. The polymer compositions are subsequently selectively hydrogenated, and are useful in a variety of compounds and end use applications.

Process for preparing block copolymer and resulting composition

Disclosed is an anionic diinitiator prepared using a diisopropenyl benzene compound and an organo lithium compound having primary polymerization sites. The anionic diinitiators are prepared by admixing a diisopropenyl benzene compound with diethyl ether, ethylene, an organo lithium compound, and a solvent under reaction conditions sufficient to prepare a diinitiator having primary lithium alkyl reactive sites. The diinitiators are particularly useful in preparing block copolymers.

Organo-dilithium compound and process for preparing the same

Anionic polymerization diinitiator and process for preparing same

Disclosed is an improvement to a process for preparing coupled styrenic block copolymers wherein adding from about 0.01 to about 1.5 equivalents of a metal alkyl compound per equivalent of living polymer chain ends to the cement, during or after polymerization, improves coupling efficiencies. The resultant radial styrenic block copolymers have reduced amounts of 5+ arm oligomers which can be very desirable is certain applications, such as the modification of bitumen.

Coupled styrenic block copolymers and process for preparing same

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.

Process for producing specific tapered block copolymers

The present invention includes star polymers which can be used as viscosity index improvers in oil compositions formulated for high performance engines. The star polymers have copolymer arms of hydrogenated polyisoprene and polystyrene with sufficient amounts of polystyrene to be finishable as a polymer crumb.

Star polymer viscosity index improver for oil compositions

A solid, cyclone-finishable polymer which does not exhibit cold flow and provides an unexpected balance of viscosity improving properties for oil compositions is produced by hydrogenating a copolymer comprising a homopolymer block of isoprene connected to a copolymer block of isoprene and a monoalkenyl aromatic hydrocarbon. The amount of the monoalkenyl aromatic hydrocarbon is sufficient to allow cyclone finishing although sufficiently distributed to provide oil compositions having good low temperature viscosity. Prior to hydrogenation, the copolymers have a number average molecular weight between 125,000 and 275,000, preferably 150,000 to 240,000, and a total monoalkenyl aromatic content between 10 and 2 percent by weight, preferably between 7 and 3 percent. The copolymer is hydrogenated to substantially saturate the isoprene and to reduce the size of monoalkenyl aromatic segments in the copolymer block.

Solid viscosity index improvers which provide excellent low temperature

Solid viscosity index improvers which provide excellant low temperature

A method for preparing asymmetric radial polymers wherein the different polymeric arms are contacted sequentially with a nonpolymerizable coupling agent. Contacting of the final step in the process, which frequently but not necessarily always will be the second step in the process, will be carried out in the presence of a polar compound suitable for increasing the amount of vinyl content in a conjugated diolefin polymer during polymerization thereof. The method used narrows the relative arm distribution of the several asymmetric radial polymers produced and significantly increases the amount of total product having the desired ratio of polymeric arms and accomplishes this objective in relatively short reaction time. Any nonpolymerizable coupling agent known in the prior art to be useful in the production of asymmetric radial polymers may be used in the method of this invention but nonpolymerizable coupling agents having from 3 to about 12 functional groups are most effective and nonpolymerizable coupling agents having 2 or 3 functional groups are most preferred. Useful polar compounds are, generally, selected from the group consisting of ethers, tertiary amines, pyridine and pyrolidene compounds.

Method for preparing asymmetric radial polymers

A method for removing a tertiary halide from an olefin hydrocarbon stream which comprises contacting the hydrocarbon stream with activated alumina at a temperature of about -40.degree. to about 120.degree. C.

Isoprene recovery in the butyl rubber process

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Kingwood, TX, United States of America

Harvey E Atwood