Abstract: Tire rubbers which are prepared by anionic polymerization are frequently coupled with a suitable coupling agent, such as a tin halide, to improve desired properties. It has been unexpectedly found that greatly improved properties for tire rubbers, such as lower hysteresis, can be attained by asymmetrically coupling the rubber.

Abstract: The present invention provides a method for producing precursor polymers which decompose to a substantially pure refractory metal carbide or refractory metal boride. The method comprises mixing a transition metal compound with either (a) an organometallic, or (b) a backbone polymer comprising a plurality of unsaturated carbon-carbon bonds. The mixing occurs under conditions effective to form organo-transition metal complexes The organometallic (a), comprises either a borane, a carborane, or an organometallic comprising a metal and at least one unsaturated carbon-carbon bond. When an organometallic (a) is used, the transition metal complexes must be polymerized to form the precursor polymers. When a backbone polymer (b) is used, the transition metal complexes, themselves, comprise the precursor polymers. The refractory metal carbides or metal borides formed upon decomposition of these precursor polymers may be used to make ceramic matrix composites and high temperature coatings.

Abstract: The invention provides a flame-retardant rubber composition which may form a vulcanizate of an elastomer whose deterioration of mechanical strength is little to enjoy excellent mechanical properties, even when a nonhalogenated flame retardant is contained in a high proportion in the composition, and a flame-retardant elastomer obtained therefrom.

Abstract: A processable rubber stock is produced by the preparation of a silica-filled, vulcanized elastomeric compound comprising mixing an elastomer with an amorphous silica filler, a processing aid comprising fatty acid ester of a polyol, optionally an additional mineral filler, and a cure agent. The elastomer is preferably a diene monomer homopolymer or a copolymer of at least one diene and at least one monovinyl aromatic monomer. By effecting vulcanization, a vulcanized elastomeric compound is produced containing good physical properties for use as tread stock for a pneumatic tire.

Abstract: The present invention describes the preparation of copolymers grafted by the so-called “grafting from” method, comprising two steps. In the first step, a polymer of a variable type referred to as poly(M1) is reacted with persistent free radicals of the type diphenyltrialkylsilyloxymethyl to form a reactive polymer poly(M1)F, containing a variable number F of these groups attached to the chain. F represents the average functionality of the reactive polymers and may be predetermined by controlling the ratio of poly(M1) and the free radical generator or TPES. In the second step, poly(M1)F is dissolved in a monomer M2 and then redissociated by heating to temperatures of 110-130° C. to produce the macroradical poly(M1) and the persistent radicals. The macroradical poly(M1) rapidly initiates polymerization whereas the diphenyltrialkylsilyloxymethyl radical stays temporarily on the sideline of the initiation reaction.

Abstract: The invention comprises a vulcanizable composition comprising a sulfur vulcanizable rubber, a sulfur vulcanizing agent, an accelerating agent in an amount effective to accelerate vulcanization and sufficient to not substantially inhibit vulcanization, and an amount effective to improve the hardness stabilization of said rubber upon vulcanization of a pyrimidine derivative. The invention also comprises a method of improving the hardness stabilization of a composition comprising a sulfur vulcanizable rubber.

Abstract: An epoxidized low viscosity polydiene polymer which has the structural formula

Abstract: New sulfur-vulcanizable, silica-reinforced tire rubber compositions and tires and tire parts, vulcanized and unvulcanized, made employing them are made with coupling agent compositions comprising a sulfur-containing norbornanyl silicon compound of the structure [Sy—R]n—SiX4−n wherein each X is chosen from monovalent hydrocarbon groups or hydrolyzable groups; y is 1 to 5 when y is 1 the compound is an episulfide, and when y is 2 to 5 the sulfur atoms form a polysulfide wherein each sulfur atom is bonded to another sulfur atom and the terminal valences of the polysulfide are bonded to vicinal carbon atoms; n is 1, 2 or 3; R is a polyvalent polycycloaliphatic hydrocarbon radical. Tires made with these compositions exhibit a desirable combination of properties, including reduced rolling resistance and road noise and maintained or improved modulus, wet traction and abrasion resistance.

Abstract: The invention relates to a process for the hydrogenation of a polymer composed of diene monomer units and nitrile group containing monomer units in which crosslinks formed as a result of the hydrogenation are broken by adding, before, during or after the hydrogenation, a compound that satisfies the formula R1—N (H) —X (I) or (R1) (R2)C═N—Y (II), where R1 is a hydrogen atom, an alkyl or cycloalkyl group with 1-30 carbon atoms, or an aromatic group with 6-30 carbon atoms and

Abstract: The invention relates to a process for the preparation of hydrophobic-hydrophilic AB block copolymers wherein block A consists of the monomer unit a, which is conjugated diene, and block B consists of the monomer unit b, which is epoxide, and the invention also relates to the AB block copolymer synthesized by the preparation process, as well as to micellar systems made from the AB block copolymer. According to the invention, the AB block copolymer is synthesized in two steps, whereby the first step is the preparation of block A in a nonpolar solvent and the second step is the preparation of block B in a polar solvent.

Abstract: The present invention provides a solid golf ball which attains long flying distance and is superior in hit feeling and durability. The present invention provides a solid golf ball in which at least a portion thereof is made of rubber, wherein the rubber portion is a crosslinked, molded rubber composition comprising a base rubber, a co-crosslinking agent and peroxides, the base rubber comprising a polybutadiene modified with a tin compound and having a cis content of 40% or more.

Abstract: This invention relates to a rubber composition comprised of a combination of cis 1,4-polybutadiene and at least one liquid hydroxyl terminated polyalkylene polymer together with a halogenated copolymer of isobutylene and p-methylstyrene and a minor amount of at least one conjugated diene-based elastomer, preferably cis 1,4-polyisoprene. The rubber composition contains particulate reinforcement as carbon black or as carbon black and silica together with a coupling agent. The invention also relates to a tire having a sidewall of such rubber composition.

Abstract: The invention relates to a process for preparing a composition comprising a vinylaromatic polymer matrix and particles of rubber, which comprises a step of polymerizing at least one vinylaromatic monomer in the presence of a rubber comprising a group which generates a stable free radical. The process makes it possible to obtain morphologies other than salami morphologies, such as the labyrinth, onion or capsule morphology, with the aim, for example, of enhancing the gloss of the high-impact vinylaromatic polymer.

Abstract: The invention provides solid supported anionic catalysts, suitable for gas phase anionic polymerization of conjugated diene monomers, that are useful for anionically producing very high molecular weight branched diene polymers, such as styrene butadiene rubber, polybutadiene rubber, polyisoprene rubber, and the like. The catalysts comprise a metalatable particle, such as a bound rubber, a thermoplastic polymer or a cured elastomer, that is multiply metalated with Group IA alkali metal atoms. The multi-branched diene polymers obtained by gas phase anionic polymerization employing the catalysts exhibit desirable properties, such as an extremely high molecular weight, a controlled molecular weight distribution, Tg and vinyl content, and the ability to readily absorb hydrocarbon solvents and oils. The polymers are easily compounded to form vulcanizable elastomeric compounds and articles, such as tires, that have excellent resistance to wear and tear and exhibit reduced hysteresis properties.

Abstract: A vulcanizate that has improved damping properties where the vulcanizate is prepared by the steps comprising blending a saturated damping additive within a vulcanizable composition of matter, wherein the vulcanizable composition of matter includes a vulcanizable elastomer, and effecting vulcanization of the elastomer.

Abstract: This invention relates to a rubber composition comprised of a combination of cis 1,4-polyisoprene rubber and at least one liquid hydroxyl terminated polyalkylene polymer and to such a composition being sulfur cured. The rubber composition can also contain an additional diene-based elastomer. The rubber composition contains reinforcement as carbon black or as carbon black and/or silica together with a coupling agent. The invention also relates to a tire having a tread of such rubber composition.

Abstract: A polymer composition useful to produce a vulcanizate having improved compound scorch safety is described. The polymer composition includes three components. The first component is a polymer selected from the group comprising nitrile polymers and ethylene polymers. The second component is a salt of a strong base and a weak acid, the salt comprising a metal selected from Group I of the Periodic Table of Elements. The third component is a vulcanization system comprising an inorganic peroxide compound and a sulfur containing compound. The polymer compositions may further comprise optional ingredients such as one or more of: a polycarbodiimide and a filler. Vulcanizates produced from the polymer composition have a surprising and unexpected combination of properties.

Abstract: The present invention provides a process for making functionalized polymers comprising the steps of (a) initiating polymerization of an unsaturated monomer with a lithium initiator having the structure R1R2R3Si—O—A—Li wherein A is a branched or straight chain bridging group having at least two carbon atoms, R1,R2, and R3 are alkyl, alkoxy, aryl, or alkaryl groups having from 1 to 10 carbon atoms, thus producing a functionalized polymer which has a protecting silyl group at one end thereof; and (b) contacting the protected polymer with from 0.5 to 1.1 moles of aqueous fluoroboric acid per mole of polymer at 0 to 50° C. for 1 to 10 minutes, and (c) contacting the resulting solution with water, and (d) recovering a linear or branched deprotected polymer having one or more terminal functional groups.

Abstract: The invention concerns a dispersion powder composition which is redispersible in water and is made from water-insoluble organic polymers, the composition being characterized in that it contains 0.1 to 30% by wt., relative to the weight of the organic polymers, of one ormore silicon compounds which are dispersible in water and which have a boiling point at normal pressure of 160° C., selected from the group comprising the silanes, polysilanes, oligosiloxanes, carbosilanes, polycarbosilanes, carbosiloxanes, polycarbosiloxanes and polysilylenedisiloxanes. The invention also concerns methods for manufacturing such compositions and their use.

Abstract: This invention is an improvement upon the current process for the production of block copolymers, especially hydrogenated block copolymers, of conjugated dienes and/or vinyl aromatic hydrocarbons which comprises anionically polymerizing the monomers in an inert hydrocarbon solvent in the presence of an alkali metal initiator whereby a polymer cement is produced and then contacting the cement with hydrogen under hydrogenation conditions in the presence of a hydrogenation catalyst. This invention and the improvement to the foregoing process comprises reducing the viscosity of the polymer cement by adding to it, preferably prior to hydrogenation (if the polymer is to be hydrogenated), from 2 to 50 % wt of a polar compound. The polar compound must be a poorer solvent for the block copolymer than is the inert hydrocarbon solvent. Preferred polar compounds include diethyl ether, tetrahydrofuran, diethoxyethane, monoglyme, diglyme, diethoxypropane, dioxane ortho-dimethoxybenzene, and the like.