Ube Industries, Inc.

Bridgestone Corporation

Naomi Okamoto

Mitsuharu Anbe

Michinori Suzuki

Masato Murakami

Takashi Wada

Koji Shiba

Kouji Ishiguchi

Takeshi Shoda

Masahiro Tanaka

Mitsuharu Eikyuu

Uchu Mukai

Osamu Kimura

Tetsuji Nakajima

Takashi Kitamura

Suguru Fukazawa

Koji Ohkawa

Jyun Yamashita

Yuta Yamada

Kanou Yuuto

Yuuki Takahashi

Masanobu Kimura

A method for producing a conjugated diene polymer having a high content of cis-1,4-structures with a high activity, a conjugated diene polymer, and a modified conjugated diene polymer. The catalyst for conjugated diene polymerization in the method includes: a non-metallocene type gadolinium compound (A) represented by the general formula (1); an ionic compound (B) formed of a non-coordinating anion and a cation; and an organic metal compound (C) of an element selected from the group consisting of a group 2, a group 12, and a group 13 of the periodic table.

Method of producing a conjugated diene polymer, a modified conjugated diene polymer, and a vinyl cis-polybutadiene composition

A conjugated diene polymer having a high content of cis-1,4-structures with a high activity, a conjugated diene polymer and a modified conjugated diene polymer using the same, a rubber composition for a tire, and a rubber composition for a rubber belt. Described are a catalyst for a conjugated diene polymerization including: a non-metallocene type gadolinium compound (A) represented by the general formula (1); an ionic compound (B) formed of a non-coordinating anion and a cation; and an organic metal compound (C) of an element selected from the group consisting of a group 2, a group 12, and a group 13 of the periodic table, a conjugated diene polymer and a modified conjugated diene polymer obtained using the same, a rubber composition for a tire, and a rubber composition for a rubber belt.

Conjugated diene polymer and modified conjugated diene polymer produced using the same, rubber composition for tire, and rubber composition for rubber belt

A catalyst for a conjugated diene polymerization including a metal compound (A) containing terbium, lanthanum, dysprosium, praseodymium, holmium, erbium, thulium, or gadolinium, an ionic compound (B) consisting of a non-coordinating anion and a cation, and an organic metal compound (C) of an element selected from the groups 2, 12 and 13 of the periodic table; a process for producing a conjugated diene polymer and a modified conjugated diene polymer using the same; a conjugated diene polymer; and a modified conjugated diene polymer.

Catalyst for conjugated diene polymerization, conjugated diene polymer, modified conjugated diene polymer, polybutadiene, and compositions comprising foregoing

The object is to provide a rubber composition for a high-strength golf ball which has a high hardness, high resiliency, excellent processability and improved filler dispersibility, by adjusting each of the Mooney viscosity, the molecular weight distribution and the n value (the rate-dependent index for Mooney viscosity) of a high-cis-polybutadiene rubber using a cobalt catalyst to a value falling within a specific range. The rubber composition comprises 100 parts by weight of a high-cis-polybutadiene synthesized using a cobalt catalyst and 10 to 50 parts by weight of a co-crosslinking agent, wherein the high-cis-polybutadiene satisfies the following requirements (a) to (c): (a) the Mooney viscosity (ML) is 40 to 55; (b) the molecular weight distribution [a weight average molecular weight MW)/a number average molecular weight (Mn)] is 3.0 to 4.2; and (c) the rate-dependent index of Mooney viscosity (n value) is 2.3 to 3.0.

Rubber composition for golf ball and golf ball

A catalyst for polymerization of conjugated diene is provided, which facilitates manufacture of a conjugated diene polymer with a high 1,4-cis structure content, leaves less aluminum residue on polymerization, and has high activity. A method of manufacturing conjugated diene polymers using the catalyst is also provided. A catalyst for polymerization of conjugated diene comprises (A) an yttrium compound; (B) an ionic compound including a non-coordinate anion and a cation; and (C) an organometallic compound including an element selected from the groups 2, 12 and 13 of the periodic table.

Catalyst for polymerization of conjugated diene and method of polymerizing conjugated diene using the catalyst, rubber composition for tires, and rubber composition for golf balls

A process for producing a vinyl-cis-polybutadiene rubber, including mixing (A) vinyl-cis-polybutadiene obtained by (1) a step of adding a cis-1,4-polymerization catalyst obtainable from an organoaluminum compound and a soluble cobalt compound to a mixture containing 1,3-butadiene and a hydrocarbon-based organic solvent as the major components and having an adjusted water content, thereby subjecting the 1,3-butadiene to cis-1,4-polymerization and subsequently, (2) a step of making a catalyst obtainable from a soluble cobalt compound, an organoaluminum compound represented by the general formula, AlR(wherein R represents an alkyl group having from 1 to 6 carbon atoms, a phenyl group, or a cycloalkyl group), and carbon disulfide present in the resulting polymerization reaction mixture, thereby subjecting the 1,3-butadiene to 1,2-polymerization; and (B) cis-polybutadiene obtained by a step of adding the foregoing cis-1,4-polymerization catalyst, thereby subjecting the 1,3-butadiene to cis-1,4-polymerization and a rubber composition containing the resulting rubber.

Process for producing polybutadiene rubber and rubber composition

The rubber composition of the invention includes a rubber composition which is a silica compounded rubber composition for tire containing 100 parts by weight of a rubber component made of (a) from 20 to 80% by weight of a vinyl-cis-polybutadiene rubber containing 1,2-polybutadiene having a melting point of 170&#xb0; C. or higher and a high-molecular substance having at least one unsaturated double bond per a repeating unit and comprising at least one member selected from polyisoprene, crystalline polybutadiene having a melting point of not higher than 150&#xb0; C., liquid polybutadiene and derivatives thereof and (b) from 80 to 20% by weight of a diene-based rubber other than (a); and (c) from 40 to 100 parts by weight of a rubber reinforcing agent containing 40% or more of silica, wherein the 1,2-polybutadiene is dispersed in a short crystalline fiber state and the high-molecular substance is dispersed in a granular state in the cis-polybutadiene rubber which is a matrix component of the subject vinyl-cis-polybutadiene rubber (a); and the short crystalline fiber of the 1,2-polybutadiene is dispersed in particles of the high-molecular substance.

Rubber composition

The invention provides a rubber composition for belt use suitable for industrial rubber belts with less energy loss and excellent durability such resistance to flex crack growth. The rubber composition for belt use comprises (A) 90-5 mass % of a vinyl-cis-polybutadiene rubber including (b) 1-30 mass % of specific syndiotactic 1,2-polybutadiene crystal fibers having an average fiber length of crystal fibers equal to 200 nm or below, an average aspect ratio of 10 or lower, the number of crystal fibers having a fiber length of 200 nm or below equal to 90 or more per 25 &#x3bc;m, and a melting point of 170&#xb0; C. or higher, and (a) 99-70 mass % of a cis-polybutadiene rubber; (B) 10-95 mass % of a diene-based rubber other than (A); and (C) 20-70 parts by mass of a rubber reinforcing agent compounded on the basis of 100 parts by mass of the rubber components (A)+(B), wherein the rubber reinforcing agent (C) contains at least carbon black and silica, wherein the compounding amount of the silica in the rubber reinforcing agent is 70 mass % or less.

Rubber composition for belt use and rubber belt

The invention has an object to provide a rubber composition for tire with improved processability and abrasion resistance. The invention relates to a rubber composition for tire, comprising: (a) 5-90 weight parts of a high cis polybutadiene having a cis structure in a proportion of 95 wt % or higher in a microstructure analysis; (b) 90-5 weight parts of a diene-based rubber other than (a); and (c) 1-100 weight parts of a reinforcing agent blended in 100 weight parts of a rubber component including (a)+(b). The high cis polybutadiene is synthesized using a cobalt-based catalyst and satisfies the requirements of: (i) a Mooney viscosity (ML) of 40-49; (ii) a molecular weight distribution [Weight average molecular weight (Mw)/Number average molecular weight (Mn)] of 3.0-3.9; and (iii) a velocity dependence index (n-value) of the Mooney viscosity of 2.3-3.0.

Rubber composition for tire and tire

A rubber composition comprises a rubber component. The rubber component contains (A) 1-70 weight parts of polybutadiene rubber having a Mooney viscosity (ML) of 35-50 and composed of (a) 1-9 weight % of a boiled n-hexane insoluble fraction having a melting point of 180&#xb0; C. or higher and (b) 99-91 weight % of a boiled n-hexane soluble fraction. The rubber component also contains (B) 99-30 weight parts of diene-based rubber other than (A). A crosslinking coagent (C) is mixed in the rubber component.

Rubber composition and golf ball including the same as rubber base material

A catalyst for polymerization of conjugated diene comprises (A) an yttrium compound; (B) an ionic compound including a non-coordinate anion and a cation; and (C) an organometallic compound including an element selected from the groups 2, 12 and 13 of the periodic table.

Catalyst for polymerization of conjugated diene and method of polymerization conjugated diene using the catalyst, rubber composition for tires, and rubber composition for golf balls

There are disclosed a resin-reinforced elastomer which comprises as principal components, a rubber and a polyolefin having an average particle diameter of at most 1 .mu.m, and in which the rubber and the polyolefin are linked together; a process for producing the resin-reinforced elastomer by melt kneading a polyolefin, a No.1 rubber and a binding agent to prepare a thermoplastic composition, adding a No.2 rubber to the resultant thermoplastic composition and melt kneading the mixture thus formed to disperse the polyolefin in the rubber components; and a pneumatic tire using the resin-reinforced elastomer in its tread. The above resin-reinforced elastomer has a uniform modulus and a low density, is minimized in directionality, and is excellent in tensile strength, fatigue resistance and abrasion resistance.

Resin-reinforced elastomer, process for producing same and pneumatic

A liquid rubber composition including a 1,2-polybutadiene resin component dispersed in the form of fine particles in a liquid rubber component in a weight ratio of 1:100 to 50:100 has a high dispersion stability and a low specific gravity and is useful for forming a cured rubber article having a high elastic modulus and a satisfactory mechanical strength and ultimate elongation.

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Ichihara, Japan

Naomi Okamoto