The Goodyear & Tire Rubber Company

George Jalics

Adel Farhan Halasa

Richard G Bauer

Lawson G Wideman

David John Zanzig

Thomas J Botzman

The process of this invention can be utilized to synthesize polymers having a high trans microstructure. The polymers which can be prepared utilizing the procedure of this invention include high trans-1,4-polybutadiene, styrene-isoprene-butadiene terpolymers with high trans-1,4-polybutadiene microstructures, high trans-isoprene-butadiene copolymers, and styrene-butadiene copolymers having high trans-1,4-polybutadiene microstructures. Such polymers can be utilized in tire tread rubber compounds which exhibit improved wear characteristics, tear resistance and low temperature performance characteristics. This invention more specifically reveals a process for synthesizing a high trans polymer which comprises adding (a) at least one organolithium initiator or organomagnesium initiator, (b) an organoaluminum compound, (c) a barium alkoxide, and (d) an organozinc compound to a polymerization medium which is comprised of an organic solvent and at least one conjugated diene monomer.

Trans microstructure directing initiator system

The present invention relates to silica-filled rubber compositions and their method of processing. The rubber compositions contain a mixture of 10 to 150 phr of a particulate precipitated silica having dispersed thereon, from 1 to 20 percent by weight based upon the weight of the silica, of a silane-modified elastomer.

Silica-filled rubber compositions and the processing thereof

The subject invention discloses a process for preparing an initiator which contains a plurality of lithium atoms and which is particularly useful for initiating the polymerization of diolefin monomers into rubbery polymers; said process being comprised of reacting an alkyl lithium compound with an unsaturated hydrocarbon containing allylic, benzylic or aryl hydrogen atoms, wherein said process is conducted in the presence of a member selected from the group consisting of alkali metal alkoxides, alkali metal phenoxides, and chelating tertiary alkyl 1,2-ethylene diamines. After the initiators of this invention have been prepared they can be employed to initiate the polymerization of diolefin monomers into rubbery polymers. They can, of course, also be employed to initiate the copolymerization of diolefin monomers and vinyl aromatic monomers into rubbery polymers. These rubbery polymers can then be used in making tire tread compounds for automobiles and trucks. They offer the advantages of better processability, treadwear characteristics, and abrasion resistance.

Process for preparing a multilithio initiator for improved tire rubbers

The subject invention relates to comb polymers having a halobutyl rubber backbone and to techniques for synthesizing such polymers. The comb polymers of this invention can be thermoplastic elastomers. For instance, halobutyl rubbers having sidechains which are derived from vinyl aromatic monomers are thermoplastic elastomers which can be made by a technique of the subject invention. Such thermoplastic elastomers typically have a chlorobutyl rubber backbone and side chains which are comprised of polystyrene. The subject invention more specifically discloses a process for grafting a lithium terminated vinyl aromatic polymer onto a halobutyl rubber which comprises: (1) capping the lithium terminated vinyl aromatic polymer with a diene monomer to produce a lithium terminated diene capped vinyl aromatic polymer, and (2) reacting the lithium terminated diene capped vinyl aromatic polymer with the halobutyl rubber to produce a halobutyl rubber having vinyl aromatic sidechains grafted thereto.

Comb polymers having a halobutyl rubber backbone

There is disclosed a process for enhancing the rate of cure of a sulfur vulcanizable rubber. Addition of a hydroformylated rubber to a sulfur vulcanizable rubber enhances the rate of cure and concomitantly improves the rubber/filler interaction of the vulcanized rubber.

Enhancing cure rates of rubber

It has been determined that metal salts of certain phenolic type antioxidants act as randomizers in the solution polymerization of conjugated diolefin monomers with copolymerizable vinyl aromatic monomers. These randomizers do not increase the vinyl content of polymers made in polymerizations which utilize them. These randomizers offer a special advantage in that they can be converted into antioxidants after polymerization has been completed in order to provide the polymer produced with stability against oxidation. The present invention specifically relates to a process for preparing a rubbery substantially random copolymer which comprises polymerizing at least one conjugated diolefin monomer with at least one copolymerizable vinyl aromatic monomer in the presence of an organolithium initiator and a randomizing agent having the structural formula ##STR1## wherein M is a metal from Group I of the periodic system, and wherein R.sup.1, R.sup.2, and R.sup.3 can be the same or different and are selected from alkyl groups, aryl groups, and tertiary-alkaryl groups, with the proviso that there is a collective total of at least 12 carbon atoms in R.sup.1, R.sup.2, and R.sup.3.

Randomizers for use in solution polymerizations

Metals from groups I and II are commonly used to catalyze the polymerization of monomers into polymers. The polymers formed in such polymerizations are terminated with the metal used to catalyze the polymerization and are sometimes referred to as living polymers. Such polymers can be crosslinked to produce a polymeric network by utilizing the process of the present invention. More specifically, the present invention discloses a process for endlinking a living polymer comprising reacting the living polymer which is metal terminated with a halogenated silicon containing compound to produce a polymer which is terminated with halogenated silicon moieties; followed by reacting that polymer with a tertiary alcohol to produce a polymer which is terminated with hydroxy silyl moieties. The polymer which is terminated with hydroxy silyl moieties can then be endlinked into a network polymer that contains siloxane linkages by simply heating it.

Siloxane containing network polymer

It has been unexpectedly found that meta-diisopropenyl benzene can be polymerized into poly-m-diisopropenyl benzene with a relatively narrow molecular weight distribution and with only a small degree of crosslinking (gel formation) if done in the presence of at least one alpha-olefin containing from 2 to 12 carbon atoms in tetrahydrofuran (solvent) at low temperatures employing an alkyl lithium initiator. The poly-m-diisopropenyl benzene produced by employing this technique has an isopropenyl moiety on almost every diisopropenyl benzene repeat unit in the polymer. This polymer is particularly useful since its pendant isopropenyl groups can be further reacted with other compounds leading to polymers with various functionalities. This technique can also be employed in the synthesis of copolymers containing repeat units derived from meta-diisopropenyl benzene and one or more other monomers. The copolymers synthesized using the process of this invention contain an essentially quantitative number of unreacted isopropenyl groups on the meta-disisopropenyl benzene repeat units in the polymer chain.

Poly-diisopropenyl benzene synthesis

The green strength of polymers produced by emulsion polymerization processes is improved through the use of carboxyl containing compounds. Specifically, the compounds are half esters of unsaturated dicarboxylic acids wherein the half ester moiety renders the carboxyl containing compound hydrophobic. As a result, carboxylic copolymers can be produced in emulsion polymerizations having a basic (pH.gtoreq.7.0) aqueous medium. Heretofore, use of carboxylic acids in emulsion polymerizations have been limited to acidic mediums.

High green strength emulsion rubbers by the use of half-esters of

Alpha-methyl-p-bromo-styrene prepared by the manipulative steps of brominating poly(.alpha.-methyl-styrene) and subsequently depolymerizing the brominated polymer. The alpha-methyl-p-bromo-styrene has particular utility as a co-monomer for preparing copolymers exhibiting a flame retardancy.

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Akron, OH, United States of America

George Jalics