Abstract: A method for producing conjugated diene rubber is provided, including: a first step of obtaining a conjugated diene polymer chain having an active end by polymerizing a monomer comprising a conjugated diene compound and a vinyl compound having a functional group interactive with silica using a polymerization initiator in an inert solvent; a second step of reacting a siloxane compound with the active end of the conjugated diene polymer chain having the active end; and a third step of reacting a hydrocarbyloxysilane compound with the conjugated diene polymer chain with which the siloxane compound has been reacted that is obtained in the second step.

Abstract: A rubber composition for heavy-load tires including an aromatic vinyl-conjugated diene copolymer having a glass transition temperature (Tg) of ?50° C. or lower and having a functional group interactive with silica; and silica.

Abstract: A conjugated diene polymer containing at least conjugated diene monomer units, wherein the conjugated diene polymer has a molecular weight distribution curve obtained by GPC measurement where three or more peaks are present, and the peak top molecular weight of a finally detected peak (Z) is 80000 to 250000, and a polymer chain corresponding to a maximum peak (L) has a degree of adsorption onto silica of less than 40% where in the molecular weight distribution curve, the last detected peak in the GPC measurement is defined as the finally detected peak (Z), and a peak having the largest peak area among peaks excluding the finally detected peak (Z) is defined as the maximum peak (L).

Abstract: A conjugated diene polymer containing at least conjugated diene monomer units, wherein the conjugated diene polymer contains 95 weight ppm or more of silicon and has an ionic strength index of 75% or less.

Abstract: A conjugated diene-based polymer including at least conjugated diene monomer units, and having a shrinkage factor of high molecular weight molecules of 0.4 to 0.8, a degree of adsorption of high molecular weight molecules onto silica of 75% or less, and a degree of adsorption of medium molecular weight molecules of 40 to 100%.

Abstract: A modified conjugated diene rubber having a modifying structure derived from a siloxane compound at at least one terminal of a polymer chain containing conjugated diene monomer unit and a monomer unit of a vinyl compound having a functional group interactive with silica.

Abstract: A conjugated diene-based rubber including a polymer block (A) containing isoprene monomer unit as the main component and a polymer block (B) containing 1,3-butadiene monomer unit as the main component, wherein at least one of the polymer block (A) and the polymer block (B) contains a unit of a vinyl compound having a functional group interactive with silica, the polymer block (A) has a weight average molecular weight (Mw) in the range of 1,000 to 30,000, and the entire conjugated diene-based rubber has a weight average molecular weight (Mw) in the range of 50,000 to 5,000,000.

Abstract: The conjugated diene-based polymer of the invention comprises an aromatic vinyl unit based on an aromatic vinyl compound and a conjugated diene unit based on a conjugated diene compound, is modified with a compound containing a heteroatom, and has an SP value of 16.80 MPa1/2 to 17.10 MPa12.

Abstract: A conjugated diene copolymer has a covalent bond reversibly dissociated and added by heat, and has at least two peaks in each of curves of molecular weight distributions measured at 40° C. and 60° C. by gel permeation chromatography, wherein a change rate of the proportion of the area of the peak having the lowest molecular weight in measurement at 60° C. to the proportion of the area of the peak having the lowest molecular weight in measurement at 40° C.

Abstract: A rubber composition contains a rubber component, an additive, and a filler, wherein the additive includes a compound including carbon atoms and at least one atomic species selected from the group made of silicon atoms, nitrogen atoms and oxygen atoms; the total number of silicon atoms, nitrogen atoms and oxygen atoms constituting the compound is 0.27 or more and 0.80 or less based on the number of the carbon atoms; the Hansen solubility parameter of the compound satisfies a relationship represented by the following formula (2); and the molecular weight of the compound is 200 or more and 15000 or less. 6?{4(?D1??D2)2+(?P1??P2)2+(?H1??H2)2}0.

Abstract: A method for producing conjugated diene rubber is provided, including: a first step of obtaining a conjugated diene polymer chain having an active end by polymerizing a monomer comprising a conjugated diene compound and a vinyl compound having a functional group interactive with silica using a polymerization initiator in an inert solvent; a second step of reacting a siloxane compound with the active end of the conjugated diene polymer chain having the active end; and a third step of reacting a hydrocarbyloxysilane compound with the conjugated diene polymer chain with which the siloxane compound has been reacted that is obtained in the second step.

Abstract: A modified conjugated diene rubber having a modifying structure derived from a siloxane compound at at least one terminal of a polymer chain containing conjugated diene monomer unit and a monomer unit of a vinyl compound having a functional group interactive with silica.

Abstract: A conjugated diene-based rubber including a polymer block (A) containing isoprene monomer unit as the main component and a polymer block (B) containing 1,3-butadiene monomer unit as the main component, wherein at least one of the polymer block (A) and the polymer block (B) contains a unit of a vinyl compound having a functional group interactive with silica, the polymer block (A) has a weight average molecular weight (Mw) in the range of 1,000 to 30,000, and the entire conjugated diene-based rubber has a weight average molecular weight (Mw) in the range of 50,000 to 5,000,000.

Abstract: The conjugated diene-based polymer of the invention comprises an aromatic vinyl unit based on an aromatic vinyl compound and a conjugated diene unit based on a conjugated diene compound, is modified with a compound containing a heteroatom, and has an SP value of 16.80 MPa1/2 to 17.10 MPa12.