Macrocyclic polymers having low hysteresis compounded properties
AssigneeBridgestone Corporation
InventorJames E. Hall
Life of this patent
Estimating the term…
Abstract
The present invention provides a method of anionic synthesis of stable macrocyclic polymers that are compounded to form vulcanizable elastomeric compounds exhibiting reduced hysteresis properties. Cyclic organometallic compounds containing divalent metal atoms of Groups IIA and IIB of the Periodic System are employed as initiators of anionic polymerization of conjugated diene, vinyl aromatic and/or triene monomers. Coupling of the living ends of the resulting macrocyclic polymers or copolymers with a coupling agent or a coupling agent that is also a functionalizing agent results in stable macrocyclic polymers with improved hysteresis properties.
Claims25
A vulcanizable elastomeric compound having reduced hysteresis properties, formed by the process of polymerizing at least one unsaturated anionically polymerizable monomer in the presence of an anionic polymerization initiator comprising a cyclic organometallic compound having a divalent metal atom (Mt) and a reactant (Rct) contained in a ring, having the formula ##STR7## where m and n are each at least one, terminating the polymerization with a coupling agent, and adding from about 5 to about 80 parts by weight of a filler selected from the group consisting of silica, carbon black, and mixtures thereof.
A functionalized macrocyclic polymer formed by the process of polymerizing at least one unsaturated anionically polymerizable monomer in the presence of an anionic polymerization initiator comprising a cyclic organometallic compound having a divalent metal atom (Mt) and a reactant (Rct) contained in a ring, having the formula ##STR8## where m and n each represent one or more, and terminating the polymerization with a functionalizing agent, wherein the monomer comprises a diene and polymerization is carried out in the presence of an agent selected from a monomer randomizing agent and a vinyl modifier for increasing the vinyl content of the polymer, and mixtures thereof.
A functionalized macrocyclic polymer formed by the process of polymerizing at least one unsaturated anionically polymerizable monomer in the presence of an anionic polymerization initiator comprising a cyclic organometallic compound having a divalent metal atom (Mt) and a reactant (Rct) contained in a ring, having the formula ##STR9## where m and n each represent one or more, and terminating the polymerization with a functionalizing agent selected from the group consisting of substituted aldimines, substituted ketimines, 4,4'-bis(dimethylamino)-benzophenone, 1,3-dimethyl-2-imidazolidinone, 1-alkyl substituted pyrrolidinones, 1-aryl substituted pyrrolidinones, dimethylamino benzaldehyde, tin tetrachloride, di(C.sub.1 -C.sub.8 alkyl) tin dichloride, tri(C.sub.1 -C.sub.8 alkyl) tin chloride, carbon dioxide, and mixtures of these.
Dependencies are inferred from the claim text.