Bridgestone Corporation

Thomas J Lynch

William L Hergenrother

David F Lawson

Jung W Kang

Hideo Takeichi

Jason T Poulton

James Oziomek

A butadiene-type polymer suitable for use as a processing aid in a rubber composition is formed by polymerizing butadiene or other conjugated diene monomers in a solvent, such as hexane, to form a polymer of relatively low molecular weight (around 30-40,000 g/mole). The polymer is coupled with a coupling agent, such as tin tetrachloride, to increase its molecular weight to a level at which conventional desolventizing processes may be used to remove the solvent from the mix. After desolventizing, the polymer is decoupled, by heating, to return the polymer to its original molecular weight.

Process for desolventizing low molecular weight diene polymers

The present invention is directed to a process for the preparation of a gel-free hydrocarbon solution containing a lanthanide rare earth series compound by dissolving or synthesizing a lanthanide compound in an inert hydrocarbon solvent with a Lewis acid in an amount sufficient to prevent formation of highly viscous solutions. The present invention is also directed to the use of the gel-free Ln solutions formed by the recited process as co-catalysts for the polymerization of dienes. The Lewis acid is a group,or,halide or organohalide, or a transition metal halide, excluding aluminum trialkyls.

Use of Lewis acids for the breakdown of gelatinous rare earth compounds in hydrocarbon solutions

The invention provides a catalyst composition, comprising: (a) an organolithium compound; and, (b) an organic acid salt of lanthanide series element; wherein: (1) only components (a) and (b) are required to promote the synthesis of 1,4-trans-polybutadiene; (2) the ratio of component (a) to component (b) is selected to maximize formation of the trans structure of said 1,4-trans-polybutadiene; and, (3) components (a) and (b) are selected for enabling further diblock synthesis. The invention further contemplates a process for using the catalyst to synthesize 1,4-trans-polybutadiene and other polymers and copolymers having trans configuration in the conjugated diene monomer contributed units.

Synthesis of 1,4-trans-polybutadiene using a lanthanide organic acid salt catalyst

The instant invention provides a process for substantially reducing the polymer cement viscosity or reducing the molecular weight distribution of the a conjugated diene polymer synthesized by using a charge of catalytically effective amounts of a rare earth catalyst and an organo magnesium component by adding an organo zinc component to the charge in an amount and under conditions sufficient to reduce the polymer cement viscosity. The invention also contemplates a catalyst compostion for substantially reducing the polymer cement viscosity of a polymer product as well the resultant polymer product.

Organo zinc and rare earth catalyst system in the polymerization of conjugated dienes

Synthesis of 1,4-trans-polybutadiene using a lanthanide organic acid

The reduction of hysteresis in a silica-filled, vulcanized elastomeric compound is produced by mixing diene monomer and optionally monovinyl aromatic monomer with a lithium amine initiator and, optionally, a modifier; effecting polymerization conditions; terminating polymerization with an amino group producing terminator to form an amine functionalized diene elastomer; compounding the amine functionalized diene elastomer with an amorphous silica filler and a vulcanization agent; and, effecting vulcanization. A pneumatic tire tread stock incorporating the vulcanized elastomer compound exhibits decreased rolling resistance in the tire.

Amine-initiated elastomers having hysteresis reducing interaction with

The reduction of hysteresis in a silica-filled, vulcanized elastomeric compound is produced by mixing diene monomer and optionally monovinyl aromatic monomer with a lithium amine initiator and, optionally, a modifier; effecting polymerization conditions; terminating polymerization with an amino group producing terminator to form an amine functionalized diene elastomer; compounding the amine functionalized diene elastomer with an amorphous silica filler and a vulcanization agent; and, effecting vulcanization. A pneumatic tire tread stock incorporating the vulcanized elastomer compound exhibits improved reduced hysteresis, or highly balanced wet traction, rolling resistance, snow/ice traction, and mechanical strength when compounded with silica filler and vulcanized, in the tire.

Composition of cyclic amine-initiated elastomers and amorphous silica

Diene polymers having a high content of trans-1,4 addition and two distinct melting points in the ranges of 30.degree. C. to 60.degree. C. and 70.degree. C. to 130.degree. C. are useful as additives to tire rubbers to improve processability by reducing compound Mooney viscosity and reducing the shrinkage of various compound stocks.

Growing community of inventors

Akron, OH, United States of America

Thomas J Lynch