Jay C Sigle

US Patent:

55021298, Mar 26, 1996

Filed:

May 13, 1994

Appl. No.:

8/242648

Inventors:

William L. Hergenrother - Akron OH
W. Novis Smith - Philadelphia PA
Anthony J. Muratore - Elverson PA
Jay C. Sigle - Downingtown PA
Mark T. Nemeth - Exton PA

Assignee:

Bridgestone Corporation - Tokyo
Cyprus Foote Mineral Co. - Malver PA

International Classification:

C08F 458
C07F 722

US Classification:

526176

Abstract:

Solutions of triorganotin lithium are described having low residual concentrations (preferably less than 2,000 ppm) of halide. These are produced by a two-step process. Triorganotin halide is reacted with lithium to produce hexaorgano ditin and a precipitate of lithium halide. The lithium halide precipitate is removed by filtration and/or use of highly concentrated reaction conditions. Then the hexaorgano ditin is further reacted with lithium to form the triorgano substituted tin lithium. The lithium halide is less soluble in hot tetrahydrofuran (THF) and/or more concentrated solutions. THF is a preferred solvent for the reaction. The low-temperature reactions described result in low amounts of inactive and/or undesirable byproducts. These triorganotin lithium compounds are useful as anionic initiators that result in polymers with terminal tin compounds, e. g. , triorganotin, attached to the terminal end of the polymer where initiation occurred.