Process and isomerizing agent for isomerizing partially hydrogenated diene polymers
AssigneeBridgestone/Firestone, Inc.
InventorsWilliam L. Hergenrother, John M. Doshak
Life of this patent
Estimating the term…
Abstract
A process for producing isomerized partially hydrogenated diene polymers containing unsaturation in endo and exo trisubstituted chain configurations while substantially eliminating the unsaturation in the 1,4-trans configuration remaining after hydrogenation, by isomerizing the unsaturation in the presence of a phosphine, borane, or alkali alkoxide isomerizing agent.
Claims10
A process for isomerizing a solution of partially hydrogenated diene polymer containing at least 50 percent by weight of diene monomer contributed units and 0 to 50 percent by weight of ethynically unsaturated monomer contributed units in an inert organic solvent in the presence of a soluble hydrogenation catalyst comprising admixing an isomerizing effective amount of a borane compound having the formula:
- R.sub.1 BR.sub.2 (R.sub.3)
- wherein R.sub.1, R.sub.2 and R.sub.3 are independently selected from the group consisting of H and alkyl, cycloalkyl and aryl groups containing 1 to 20 carbon atoms and combinations thereof;
- to the solution and heating the solution to isomerize the diene monomer contributed units of the partially hydrogenated diene polymer to produce a diene polymer having an unsaturation ratio of at least 3 to 1, said unsaturation ratio being defined as a ratio of a combined total of unsaturation groups in the diene monomer contributed units in an endo and an exo configuration to a combined total of unsaturation groups in the diene monomer contributed units in a 1,4-cis, 1,4-trans and vinyl configuration.
Dependencies are inferred from the claim text.