Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A modified conjugated diene polymer and a method for producing the same. A rubber composition using the same. A modified conjugated diene polymer obtained by polymerizing a conjugated diene compound using a catalyst including from (A) an yttrium compound having a bulky ligand represented by general formula (1), (B) an ionic compound formed of a non-coordinating anion and a cation, and (C) an organic metal compound of an element selected from the group consisting of group 2, group 12 and group 13 of the periodic table and modifying the conjugated diene polymer with a carbonyl compound, a method for producing the same, and a rubber composition using the same.

Abstract: Provided are a catalyst for a conjugated diene polymerization capable of 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 using the same, production methods thereof, 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, production methods thereof, a rubber composition for a tire, and a rubber composition for a rubber belt.

Abstract: Disclosed is a process for producing a conjugated diene polymer having a very high content of cis-1,4 structures by using an yttrium compound-containing catalyst that is relatively easy to handle and has a high activity. Specifically disclosed is a process for producing a conjugated diene polymer containing cis-1,4 structures at a ratio of 99% or higher, which is characterized by polymerizing a conjugated diene in the presence of a catalyst produced from (A) a specific yttrium compound, (B) an ionic compound consisting of a non-coordinating anion and a cation, and (C) an organoaluminum compound.

Abstract: 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.

Abstract: Disclosed is a process for producing a conjugated diene polymer having a very high content of cis-1,4 structures by using an yttrium compound-containing catalyst that is relatively easy to handle and has a high activity. Specifically disclosed is a process for producing a conjugated diene polymer containing cis-1,4 structures at a ratio of 99% or higher, which is characterized by polymerizing a conjugated diene in the presence of a catalyst produced from (A) a specific yttrium compound, (B) an ionic compound consisting of a non-coordinating anion and a cation, and (C) an organoaluminum compound.

Abstract: A method for producing a polybutadiene, which comprises subjecting 1,3-butadiene to cis-1,4 polymerization, and subsequently subjecting a resultant in the resulting polymerization system to syndiotactic-1,2 polymerization, the method being characterized in that there is added, after the polymerization, a halogen acid or halogen acid salt.

Abstract: 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.

Abstract: [Subject] 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. [Solution] 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.

Abstract: A method for producing a polybutadiene, which comprises subjecting 1,3-butadiene to cis-1,4 polymerization, and subsequently subjecting a resultant in the resulting polymerization system to syndiotactic-1,2 polymerization, the method being characterized in that there is added, after the polymerization, a halogen acid or halogen acid salt.

Abstract: [Subject] 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. [Solution] 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.

Abstract: Modified polybutadiene having a high-cis and low-trans structure with a moderate 1,2-structure content and exhibiting improved characteristics such as cold flow properties, which is obtained by modifying starting polybutadiene having a Tcp/ML1+4 ratio (Tcp: 5% toluene solution viscosity at 25° C.ML1+4: Mooney viscosity at 100° C.) of 2.5 or more in the presence of a transition metal catalyst.

Abstract: Modified polybutadiene having a high-cis and low-trans structure with a moderate 1,2-structure content and exhibiting improved characteristics such as cold flow properties, which is obtained by modifying starting polybutadiene having a Tcp/ML1+4 ratio (Tcp: 5% toluene solution viscosity at 25° C.ML1+4: Mooney viscosity at 100° C.) of 2.5 or more in the presence of a transition metal catalyst.

Abstract: Modified polybutadiene having a high-cis and low-trans structure with a moderate 1,2-structure content and exhibiting improved characteristics such as cold flow properties, which is obtained by modifying starting polybutadiene having a Tcp/ML1+4 ratio (Tcp: 5% toluene solution viscosity at 25° C.ML1+4: Mooney viscosity at 100° C.) of 2.5 or more in the presence of a transition metal catalyst.

Abstract: The present invention provides a process for the production of a conjugated diene polymer having a controlled microstructure at a high polymerization activity in the presence of a metallocene type complex of compound of transition metal of the group V of the Periodic Table. A novel catalyst is provided comprising (A) a metallocene type complex of a transition metal of the group V of the Periodic Table, (B) an ionic compound of a non-coordinating anion and a cation, (C) an organic metal compound of the groups I to III and (D) water, wherein the molar ratio of (C)/(D) is from 0.66 to 5.

Abstract: A catalyst obtained by contacting (A) a compound of a transition metal of the group V of the Periodic Table represented by formula (I):R.sub.n M(O).sub.m X.sub.p .cndot.L.sub.

Abstract: Rubber-modified, impact-resistant polystyrene resin compositions having a well balanced combination of improved properties such as tensile strength and tensile elongation as well as reactivity with styrene monomers, impact resistance, low-temperature properties, and gloss, comprise dispersed particles of a rubber polymer which satisfies the following: (1) the content of the rubber polymer in the compositions is from 1 to 25% by weight; (2) the rubber polymer is a high-cis high-vinyl polybutadiene comprising from 65 to 95% cis-1,4-structures and from 30 to 4% 1,2-structures; and (3) the relationship between the 1,4-structures and 1,2-structures of the rubber polymer is represented by the following expression (A), wherein the value of .beta. is in the range of 1.0<.beta..ltoreq.1.43;.beta.=P.sub.1,2-,1-4 /(2.times.P.sub.1,2 .times.P.sub.1,4)(A)wherein P.sub.1,2 represents the content of 1,2-structures, P.sub.1,4 represents the content of 1,4-structures, and P.sub.