Abstract: A method for preparing a polymodal MWD ethylene-alpha olefin copolymer using at least two catalysts to initiate growth of polymer chains that attain different average molecular weights. The polymodal MWD ethylene copolymer comprises at least two different molecular weight modes each mode having a narrow MWD and at least one of two characteristics (1) an Mw/Mn of less than 2 and (2) Mz/Mw of less than 1.8.

Abstract: Into a material based on a caoutchouc-type or caoutchouc-containing mixture for producing hard rubber, there is incorporated a pre-mix containing high-strength organic fibers and a liquid hardenable plastic material. The high-strength and temperature resistant material thus obtained is particularly suitable for the attenuation of noise in combustion engines when heavy-weight fillers are also added to such material. Engine components like, for example, valve covers, timing gear covers and oil pans can be manufactured from this material.

Abstract: Polymodal MWD ethylene copolymer comprising at least two modes of differing molecular weights. Each mode has at least one of M.sub.w /M.sub.n of less than 2.0, and a M.sub.z /M.sub.w of less than 1.8. The polymodal character of the copolymer is achieved by either (1) withdrawing polymer modes from the reactor from at least one takeoff port, and blending such modes with the reactor effluent, or (2) utilizing at least two catalyst species in the reaction to produce modes of differing molecular weights.

Abstract: Tire treads having(a) low heat buildup under dynamic stress and a low frictional resistance to rolling,(b) adequate damping and accordingly a high wet skid resistance,(c) high abrasion resistance and accordingly high wearing efficiency, are produced from vulcanizable compositions based on an elastomer component containing an isoprene polymer characterized by a high content of recurring units obtained by 1,2- and 3,4-polymerization of isoprene.

Abstract: A rubber composition for an inner liner of a vehicular tire, high in stickiness before vulcanization and in adhesive strength after vulcanization and having good low temperature characteristics so as to effectively suppress crack formation in the inner liner. The rubber composition comprises a rubber component including halogenated butyl rubber ranging from 60 to 100 parts by weight, and diene rubber not more than 40 parts by weight. Tert-butylphenolacetylene resin is blended in a range from 0.5 to 10 parts by weight with 100 parts by weight of the rubber component.

Abstract: A diene polymer composition having improved fracture properties and a small change in the shape of extruded product is disclosed, which comprises at least 5% by weight of a copolymer composed of at least one conjugated diene (component A) having the following general formula: ##STR1## wherein R.sub.1 and R.sub.2 are a hydrogen atom or a methyl group, and 2,3-dimethylbutadiene (component B), said copolymer having a content of cis-1,4-bond of not less than 80%.

Abstract: Rubber compositions for use in tire tread compounds comprise co-vulcanizable blends of high 1,2 (vinyl) content polybutadiene of high molecular weight and high cis-1,4-poly-butadiene of high molecular weight. The blends show a high degree of homogeneity, so that they act effectively as a single polymer, and exhibit a substantial absence of a glass transition temperature. Both of the polymers in the composition should have a relatively high weight average molecular weight. The relative amounts of the two polymers are such as to obtain a 1,2-group content in the blend of from 35-65 percent (i.e. from 35-65 percent of the polymer units are in the 1,2-configuration). The blend may be compounded with conventional compounding ingredients for curing purposes, and optionally with additional polymers as natural rubber and/or SBR. The vulcanizates of the compositions exhibit a superior and unexpected balance of resilience, traction and wear properties.

Abstract: Compositions comprising blends of polyhydroxybutadiene homopolymers and amine terminated polybutadienes useful for the preparation of polyurea and/or polyurethane elastomers, sealants, coatings and binders are disclosed as well as a process for the preparation of the polyurea/polyurethanes.

Abstract: Rubber modified styrene-acrylonitrile polymers (ABS) having three different types of rubber particles. One type is small, usually emulsion-produced particle. The second is a large emulsion-produced particle. The third is a large, mass-produced particle. Such compositions exhibit good combinations of toughness and gloss.

Abstract: Disclosed is a high-performance tire in which a bead filler formed of a rubber composition fills up a space between each turn-up portion of the carcass and a major portion of the carcass and extends to some extent along the carcass toward the tread. The rubber composition is anisotropic such that the elastic modulus in the direction circumferential of the tire is distinctly higher than in the direction radial of the tire. Such anisotropy can be produced by incorporating short fiber of a suitable thermoplastic polymer such as nylon into the rubber composition. This tire provides both improved controllability and a good ride.

Abstract: This invention relates to a method of and devices for impact and vibration damping and, more particularly, to devices composed of an elastoplastic material including the characteristics of damping, heat and pressure dimensional stability, and moisture non absorbency of a blend of polyolefin and conjugated diene butyl rubber which converts impact shock or vibration energy into thermal energy.

Abstract: Novel rubber connectors and other rubber parts for use in human infusion sets and rubber compositions and other rubber parts for use in human infusion sets and products produced thereby, such compositions comprising by weight a major amount of rubber selected from mixtures of natural rubber and synthetic natural rubber, the novel composition further comprising by weight a minor amount of a high density polyolefin and a filler, the composition being capable of being cured with an effective amount of a peroxide curing agent and an activator to achieve cross-linking of the rubber and the high density polyolefin.

Abstract: Solid golf balls are formed from a molding composition comprising (1) a polybutadiene blend of (A) a polybutadiene synthesized using a nickel and/or cobalt base catalyst and having a Mooney viscosity of 70 to 100 with (B) less than 50 parts by weight of a polybutadiene synthesized using a lanthanide rare earth element base catalyst and having a Mooney viscosity of 30 to 90 or (C) 20 to 80 parts by weight of a polybutadiene synthesized using a nickel and/or cobalt base catalyst and having a Mooney viscosity of 20 to 50, the polybutadienes containing at least 40% of cis-1,4 bond, (2) a crosslinking agent such as acrylic and methacrylic acid, (3) an inorganic filler, and (4) an organic peroxide.

Abstract: Rubbery high trans-high vinyl diblock copolymers, blends of rubbery high trans copolymers and rubbery high vinyl polymers, and mixtures (alloys or blends) of said diblock copolymers, high trans copolymers and high vinyl polymers are useful in producing tire treads exhibiting good processibility, good rolling resistance, skid resistance and abrasion resistance. The high trans block or copolymer comprises a copolymer of butadiene-1,3 and styrene and/or isoprene and the high vinyl block or polymer comprises polybutadiene or copolymers of butadiene and styrene and/or isoprene. These di-block copolymers, copolymers and polymers are made by solution polymerization. The diblock copolymer may be made by copolymerizing butadiene and styrene and/or isoprene using a Ba, Ca or Sr alcoholate, R.sub.2 Mg and R.sub.

Abstract: Disclosed is a diene elastomer composition especially suitable as tread rubber of tires which has low rolling resistance and high wet grip in combination. This elastomer composition contains a rubber material comprising an elastomeric polymer component of a butadiene polymer and/or a styrene-butadiene copolymer and a rubbery component. The elastomeric polymer is produced by using an organolithium compound as a polymerization initiator, and has a long chain end concentration (LCEC) of 1.5 or less as defined by the following formula: ##EQU1## wherein .alpha.: total number of terminal groups in long chain molecules per polymer,MW: a value obtained from intrinsic viscosity of the polymer as measured in toluene at 30.degree. C. by the following formulas:MW=70,660 x[.eta.].sup.1.282 for styrene-butadiene copolymer,MW=79,167 x[.eta.].sup.1.443 for butadiene polymer,.beta.i: weight fraction of component i when MW=(MW).sub.i.

Abstract: Elastomeric compositions containing EPDM elastomers are provided, the vulcanizates of which show substantially improved adhesion properties with good dynamic ozone resistance, superior aged fatigue life and high resilience. The EPDM used is of high molecular weight and has a non-conjugated diene content of at least 6 weight percent preferably at least 7.5%. The composition also contains highly unsaturated elastomers, such as natural rubber and polybutadiene, as the additional elastomeric components.

Abstract: A pneumatic tire suitable for running on snow and ice roads is improved by providing tread portion composed of a rubber composition comprising 100 parts by weight of a blend rubber consisting of (A) 50 to 90 parts by weight of at least one rubber selected from the group consisting of natural rubber, polyisoprene rubber, butadiene-styrene copolymer rubber, polybutadiene rubber, butyl rubber and halogenated butyl rubber and (B) 10 to 50 parts by weight of a diene type rubber containing 0 to 25% of styrene group (x) and 0 to 50% of 1,2 vinyl bond group (y), (x) and (y) satisfying the following relationship: ##EQU1## mixed with 40 to 100 parts by weight of carbon black and 0 to 60 parts by weight of a softener and vulcanized.

Abstract: Petroleum resins having a softening point from 10.degree. C. to 80.degree. C. obtained from C.sub.5 olefines and diolefines and one or more monovinyl aromatic compounds which contain from 10 to 30 wt. % of the aromatic are useful as tackifiers for carboxylated styrene butadiene copolymer to produce pressure sensitive additives especially aqueous based adhesive when the resin is in the form of an emulsion which is also claimed.

Abstract: Guayule resin is sulfurized such that it has a high softening point of at least 70.degree. C. The sulfurized guayule resin can be utilized in association with conventional rubbers and the end results in improved properties such as reduced hysteresis loss, increased tensile strength and the like.

Abstract: Rubbery high trans-high vinyl diblock copolymers, blends of rubbery high trans copolymers and rubbery high vinyl polymers, and mixtures (alloys or blends) of said diblock copolymers, high trans copolymers and high vinyl polymers are useful in producing tire treads exhibiting good processibility, good rolling resistance, skid resistance and abrasion resistance. The high trans block or copolymer comprises a copolymer of butadiene-1,3 and styrene and/or isoprene and the high vinyl block or polymer comprises polybutadiene or copolymers of butadiene and styrene and/or isoprene. These di-block copolymers, copolymers and polymers are made by solution polymerization. The diblock copolymer may be made by copolymerizing butadiene and styrene and/or isoprene using a Ba, Ca or Sr alcoholate, R.sub.2 Mg and R.sub.

Abstract: An adhesive composition for filling gaps and sealing joints in engineering assembly comprises a blend of 100 parts by weight of a liquid polybutadiene polymer having an average molecular weight from 1,000 and a viscosity from 2 to 800 dPas at 25.degree. C., at least 40 percent of the unsaturation having a 1,4 configuration, preferably cis 1,4; 5 to 60 parts of powdered sulphur; 2.5 to 70 parts of an organic accelerator or accelerators; and up to 80 percent by weight of an inert filler or fillers. The adhesive composition may also include promoters, dessicants, blowing agents and/or solid rubber, preferably solid polybutadiene.

Abstract: An object of the present invention is to obtain a tennis ball and a core for tennis ball which keeps high values within the ITF standard and besides has excellent durability.That is, the present invention provides a core for tennis ball obtained by vulcanizing a rubber composition containing, in its whole rubber component, 5 to 40 weight % of a 1,2-bond containing polybutadiene and 60 to 95 weight % of a natural rubber and/or high cis-polybutadiene containing not less than 90% of a cis 1,4-bond, and tennis balls obtained therefrom.

Abstract: Pressureless tennis balls which comply with regulations of the International Tennis Federation and produce a satisfactory feel of striking retained over an extended period of play, and which comprises a hollow spherical core made from a rubber composition the rubber component of which contains 5 to 50% by weight of a particular modified polybutadiene containing 5 to 30% by weight of syndiotactic-1,2-polybutadiene and at least 40% by weight of cis-1,4-polybutadiene.

Abstract: A rubber composition for tire tread, comprising natural rubber and/or polyisoprene rubber and polybutadiene rubber, which polybutadiene rubber having a 1,2-bond unit content in the range of 40 to 90 mol % and having a specific functional group contained in the molecular chain thereof.

Abstract: A rubber composition for tire treads, comprising [I] 10 to 70% by weight of a polybutadiene rubber having bonded to a carbon atom of the rubber molecular chain at least 0.1 mole, per mole of the rubber molecular chain, of an atomic grouping represented by the following formula ##STR1## wherein X represents O or S, R.sub.1 and R.sub.2 are identical or different and each represents an amino group or an alkyl-substituted amino group, R.sub.3 and R.sub.4 are identical or different and each represents a substituent other than the above-mentioned, m, p and q each represent O or an integer of at least 1, n represents an integer of at least 1, m+p=0-5, and n+q=1-5,and [II] 90 to 30% by weight of at least one rubber selected from the group consisting of styrene-butadiene copolymer rubber having a bound stryene content of not more than 50% by weight and polyisoprene rubber.

Abstract: Additives for rubber compositions, giving vulcanizates having improved retention of optimum physical properties, are polymeric trithiocarbonates having a structure comprising repeating units of the formula ##STR1## where R is an organic bridging group, e.g. an alkylene group.

Abstract: A rubber composition comprising at least 10% by weight, based on the entire rubber component, of a highly unsaturated polymer rubber having a benzophenone introduced into its molecular chains in an amount of at least 0.1 mole per mole of the rubber molecular chains.

Abstract: A diene rubber composition comprising 25 to 90 parts by weight of at least one high molecular weight diene rubber (A) having an intrinsic viscosity [.eta.] of at least 2.0 and a glass transition point of not lower than -50.degree. C. and 75 to 10 parts by weight of at least one low molecular weight diene rubber (B) having an intrinsic viscosity [.eta.] of 0.01 to 2.0, said composition having an average intrinsic viscosity of at least 1.8.Since this composition has an excellent wet grip and rolling resistance property and moreover has excellent processability, it is employed as tire tread rubber.

Abstract: A pneumatic tire with a sulfur cured elastomeric tread composition comprised of medium vinyl polybutadiene cis 1,4-polyisoprene rubber and styrene/butadiene copolymer rubber.

Abstract: A rubber composition having improved wet skid resistance and rolling resistance is disclosed, which comprises (A) 10-90% by weight of polybutadiene rubber having a content of cis-1,4-bond at least 80% and an average chain length of cis-1,4-bond of not less than 110, and (B) 10-90% by weight of random styrene-butadiene copolymer rubber obtained by copolymerization in the presence of an organic metal catalyst and having a content of bound styrene of not more than 40% by weight and a content of 1,2-bond in total butadiene unit of 30-95%.

Abstract: Treatment of diene rubber with a diketo compound, in which the keto groups are part of a six-carbon hydrocarbon ring containing carbon-to-carbon unsaturation, or a tautomer of the compound, is performed at temperatures above 130.degree. C. Rubber compositions treated in this manner exhibit increased green strength, decreased plasticity, and, when vulcanized, decreased hysteresis.

Abstract: A rubber composition having an improved crack growth resistance is disclosed, which contains 1-40 wt % of granular bodies having an average particle diameter of 5-500 .mu.m, which contain 2-40 wt % of micro short fibers having an average diameter of not more than 1 .mu.m, an average length of 1-30 .mu.m and an aspect ratio of not less than 8 and orientated in uniaxial or biaxial direction, and is random in the orientation axis of the micro short fiber between the granular bodies.

Abstract: A rubber composition for use in tires is disclosed, which comprises 1-30% by weight of a non-crystallizable resinous polymer having Tg of not less than 110.degree. C. and 70-99% by weight of at least one rubber selected from styrene-butadiene copolymer rubber containing not more than 60% by weight of bound styrene, natural rubber, polybutadiene rubber having 1,4-configuration of not less than 80%, polybutadiene rubber having 1,2-configuration of not less than 50%, butyl rubber, halogenated butyl rubber and polyisoprene rubber having cis-1,4-configuration of not less than 90%.

Abstract: Pneumatic tire having circumferential fabric-reinforced rubber belt positioned between its tread and carcass where the rubber of the belt is comprised of medium vinyl polybutadiene, cis 1,4-polyisoprene and optionally, cis 1,4-polybutadiene. The invention is particularly directed to such tire where the medium vinyl polybutadiene rubber of said belt is a copolymer of 1,3-butadiene and a small amount of divinyl benzene.

Abstract: A diene rubber composition comprising as a main rubber component an elastomeric polymer having a glass transition temperature of not less than -50.degree. C. selected from the group consisting of a butadiene homopolymer and a copolymer of butadiene and an aromatic vinyl compound, said elastomeric polymer being one prepared by a solution polymerization method and not less than 40% by weight to less than 65% by weight of the polymer chains thereof being branched polymer chains formed by coupling the polymer molecules with each other with a trifunctional or tetrafunctional coupling agent. The composition has excellent rolling resistance characteristic, wet grip characteristic, processability, tear strength and tackiness, and is suitable particularly for use in the tread portion of tires.

Abstract: Vulcanizable rubber compositions and articles such as tires having improved metal adhesion and metal adhesion retention to brass and brass-plated metallic reinforcement. The improvement comprises substituting at least about 10.0 parts by weight of a halogenated rubber for non-halogenated rubber present in the vulcanizable rubber composition. The non-halogenated rubber can be natural or synthetic or blends thereof. A method for improving the metal adhesion and metal adhesion retention between a vulcanizable rubber and brass or brass-plated metallic reinforcement includes the steps of blending at least about 10.0 parts by weight of a halogenated rubber with up to about 90.0 parts by weight of a vulcanizable rubber essentially free of other halogenated rubber and curing the blend of rubbers with the brass or brass-plated metallic reinforcement embedded therein.

Abstract: A primer composition for use in the bonding of asphalts comprising the reaction product of an elastomer and a terpene resin. The primer composition of this invention can be used in the treatment of substrates to which asphalts are bonded to improve the bonding relationship between the substrate and the asphalt, such as in road-paving applications, roofing applications and the like.

Abstract: A rubber composition having excellent fracture properties and cut growth resistance is disclosed, which consists of 10-95 parts by weight of polybutadiene having a content of cis-1,4 bond of at least 70% and an average chain length of 1,4-sequence of 110-450 and 90-5 parts by weight of at least one diene rubber.

Abstract: A heterogeneous rubber composition having good air impermeability is made by mixing together separate fractions of rubbers and fillers.

Abstract: A process for dielectrically heating and thermoforming a non-polar thermoplastic material by electromagnetic field energy is accomplished by the addition of a polar domain-containing material having at least one nitrile group to the thermoplastic material. Compositions comprising thermoplastic material and a polar domain containing material useful in this process are also described.

Abstract: A rubber composition having improved cut growth resistance, processability and dimensional stability is disclosed, which comprises not less than 20 parts by weight of polyisoprene having a melting point of not less than 10.degree. C. and a content of cis-1,4 bond of not less than 88% and the balance of at least one diene rubber.

Abstract: A rubber material having an excellent grip on ice comprising a mixture of an ordinary rubber and a powdered polymer, said powdered polymer having a maximum of tan .delta. at a temperature in the range of -5.degree. C. to +35.degree. C. when the tan .delta. is measured by a nonresonance, forced vibration apparatus at a frequency of 110 hertz and a heating rate of 2.degree. C./minute.

Abstract: Compositions having improved low temperature impact strength are provided which comprise a mixture of high density polyethylene and polybutadiene. Such compositions may be used for coating of pipes, especially for Arctic-type use conditions or for containers for low temperature use.

Abstract: A soft, fatigue resistant vulcanizate adapted for transmitting load between moving mechanical parts comprising (a) 100 parts by weight of crosslinked elastomer, (b) a fatigue life enhancing amount of substantially internally saturated, substantially linear polymer that (i) is made from monomers consisting essentially of isobutylene, (ii) is a strain crystallizable, elastic solid at 20.degree. C. and (iii) has a viscosity average molecular weight (Flory) above about 1.3 million, (c) about 5-200 parts by weight particulate comprising carbon black, said elastomer being crosslinked with (d) curative in an amount sufficient to crosslink said elastomer, wherein said polymer of (b) is dispersed throughout said elastomer of (a) in a discrete microscopic phase.

Abstract: A rubber composition comprising as main components (1) at least one rubber having a glass transition temperature of from -45.degree. C. to 0.degree. C. and selected from the group consisting of an isoprene-butadiene copolymer rubber and polyisoprene rubber and (2) at least one rubber selected from the group consisting of natural rubber and cis-1,4-polyisoprene rubber having a cis-1,4-linkage content of at least 90 mole %, said composition having a value, defined by the following formula, of at least 10,[(R-53)+(S-100)]wherein R is a rebound (%) measured at 51.degree. C. by a Dunlop Tripso meter for a vulcanized product of said rubber composition, and S, as defined in the specification, is a wet skid resistance index on a road surface defined by ASTM E-303-74 which is determined at 19.degree. C. by a portable skid tester for a vulcanized product of said rubber composition.

Abstract: A radial tire having an under-tread layer between a cap tread and a breaker layer is disclosed. As the material for the cap tread, a rubber composition is employed which contains 0.5 to 1.6 parts by weight of sulfur per 100 parts by weight of starting rubber components consisting of 25 to 75 parts by weight of polybutadidne rubber having 65 to 90 mol % of 1,2-bonding units and 75 to 25 parts by weight of natural rubber and/or polyisoprene rubber, and which has elongation at break of at least 330% at 100.degree. C. A rubber composition containing 1.6 to 10 parts by weight of sulfur per 100 parts by weight of rubber components is used for the under-tread layer.

Abstract: A process is provided for the production of vulcanizates having improved properties wherein polymer (or polymers) is mixed with carbon black in two separate steps such that in one step a major proportion of the carbon black to be used is mixed with polymer and in a second step a zero to minor proportion of the carbon black to be used is mixed with polymer. Such improved vulcanizates may be used, for example, in tires or a variety of mechanical goods.

Abstract: A stabilized polyisoprene composition comprising 100 parts by weight of polyisoprene and 0.15-3.0 parts by weight of a binary system antioxidant consisting of 50-99% by weight of a phosphite type antioxidant represented by the formula, ##STR1## wherein R.sub.1, R.sub.2, and R.sub.3 are same or different aryl groups, and 50-1% by weight of a triazine derivative type antioxidant represented by the formula, ##STR2## wherein X.sub.1, X.sub.2, and X.sub.3, which may be the same or different, are selected from the group consisting of --NH--, --O--, and --S--, and R', R", and R"', which may be the same or different, represent alkyl, or alkyl-substituted or unsubstituted hydroxyphenyl groups. This binary system antioxidant exhibits a synergistic effect on the stabilization of polyisoprene against heat and oxygen.

Abstract: A thermosetting composition in which high vinyl diolefin polymer chosen from among homopolymers of 1,3-butadiene and copolymers of 1,3-butadiene with styrene are admixed with about 15 to about 35 weight percent of the total polymer phase of a normally solid, elastomeric 1,3-butadiene homopolymer having high vinyl and low vinyl segments in a weight ratio of about 60:40 to about 40:60. Preferably the thermosetting composition also contains from about 15 to about 35 weight percent of the total polymeric phase of a normally solid rubbery polymer of isobutylene.

Abstract: A soft, heat and fatigue resistant vulcanizate adapted for transmitting load between moving mechanical parts comprising (a) 100 parts by weight of crosslinked elastomer consisting essentially of (i) natural or synthetic polyisoprene rubber, and (ii) elastomeric polybutadiene made from monomers consisting essentially of butadiene at a weight ratio of (i) to (ii) of about 1:10 to 10:1, (b) about 10-75 parts by weight of substantially internally saturated, substantially linear polymer that (i) is made from monomers consisting essentially of isobutylene, (ii) is a strain crystallizable, elastic solid at 20.degree. C. and (iii) has a viscosity average molecular weight (Flory) above about 1.