Rubbery conjugated diene polymers terminated with hydrocarbyl phosphites
AssigneePhillips Petroleum Company
InventorsCarl A. Uraneck, John E. Burleigh
Life of this patent
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Abstract
Solution polymerized rubbery conjugated diene homopolymers and copolymers with monovinylarenes are terminated with a hydrocarbyl phosphite or thiophosphite. The phosphite terminated polymers, particularly medium-vinyl polybutadiene, can be incorporated in rubber/carbon black/oil tread stock compounds employing up to 65 parts of rubber per 100 parts of polymer and up to 30 parts of oil per 100 parts of polymer for higher resilience, lower hysteresis, and generally higher tensile strength after vulcanization.
Claims29
A rubbery conjugated diene polymer, wherein said diene polymer is a polymer of at least one conjugated diene, or copolymer thereof with at least one monovinylarene wherein the copolymerized conjugated diene content is at least 60 weight percent, characterized by treatment of the polymer in hydrocarbon solution as polymer-alkali metal with at least one mole of trihydrocarbyl phosphite or trihydrocarbyl thiophosphite per g-atom of alkali metal in the polymer such that the resulting said diene polymer contains about 0.005 to 0.3 weight percent phosphorus as P.
An uncured compound comprising (a) a conjugated diene rubber selected from polymers of at least one conjugated diene and copolymers thereof with at least one monovinylarene, wherein said conjugated diene rubber is a trihydrocarbyl phosphite or trihydrocarbyl thiophosphite terminated solution polymerized hydrocarbon conjugated diene rubber solution-polymerized conjugated diene rubber produced by treating in solution a conjugated diene polymer as the polymer-alkali metal, resulting from solution polymerization of a conjugated diene alone or with a monovinylarene with an alkali metal initiator, with at least about one mole of said trihydrocarbyl phosphite or trihydrocarbyl thiophosphite per g-atom of said alkali metal, prior to inactivation of polymer-alkali metal, such that the resulting treated rubber exhibits a phosphorus content as P of about 0.005 to 0.3 weight percent, (b) carbon black, and (c) about 3 to 30 php extender oil.
A process of preparing a phosphorus-containing conjugated diene rubbery polymer, said polymer selected from conjugated diene homopolymers, and copolymers of at least one conjugated diene with at least one monovinylarene in a weight ratio of at least 50:50 to 99:1 conjugated diene:monovinylarene, which comprises contacting said diene polymer as the alkali metal-terminated diene polymer in hydrocarbon solution with at least about one mole per one g-atom of alkali metal in the polymer of a phosphite treating agent selected from the group consisting of trihydrocarbyl phosphites and thiophosphites represented by P(XR).sub.3 wherein P is phosphorus;
- each X is oxygen or sulfur;
- and each R is alkyl, cycloalkyl, or aralkyl, of 1 to 20 carbon atoms, whereby said phosphorus contains conjugated diene rubbery polymer contains about 0.005 to 0.03 weight percent phosphorus.
Dependencies are inferred from the claim text.