Abstract:
A process for simply and inexpensively producing a conjugated diene polymer with a narrow molecular weight distribution and a high cis-bond content at a low cost is provided. The process comprises a polymerization step, wherein a conjugated diene polymer having a cis-1,4-bond content of 98.5 mass % or more and a ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) measured by gel permeation chromatography of 2.5 or less is obtained by carrying out a polymerization reaction in conjugated diene compounds using a catalyst composition containing a rare earth element-containing compound or a reaction product of the rare earth element-containing compound with a Lewis base, an aluminoxane and/or organoaluminum compound, and an iodine-containing compound.
Abstract:
A method for producing a modified conjugated diene polymer includes carrying out a modification reaction that reacts a modifier that includes a specific compound with a conjugated diene polymer having a cis-1,4-bond content of 98.5% or more and possessing an active end to introduce the modifier into the active end of the conjugated diene polymer to obtain a modified conjugated diene polymer. The modified conjugated diene polymer that exhibits excellent wear resistance, excellent mechanical properties, and reduced cold flow can be obtained by the method.
Abstract:
A method for producing a modified conjugated diene polymer includes a step (A) carrying out a primary modification reaction that reacts a heterocumulene compound having two or more specific functional groups with a conjugated diene polymer having a vinyl content of below 10% and a cis-1,4-bond content of 75% or more and possessing an active end to obtain a primary-modified conjugated diene polymer, and a step (B) carrying out a secondary modification reaction that reacts an active hydrogen-containing compound that includes one or more functional groups selected from the group consisting of an amino group, an imino group, a mercapto group, and a hydroxyl group with the primary-modified conjugated diene polymer to obtain a secondary-modified conjugated diene polymer. The method can produce a modified conjugated diene polymer that exhibits low heat build-up (low fuel consumption) and excellent wear resistance.
Abstract:
A process for producing a modified polymer which increases low heat buildup and reinforcing capability of a rubber composition and which has excellent abrasion resistance, mechanical characteristics, and processability; a modified polymer obtained by the process; and a rubber composition using the modified polymer are provided. The process comprises a step of carrying out a modification reaction on the active end of a conjugated diene polymer having a vinyl content of below 10%, a cis-1,4 bond content of 75% or higher, and an active end, using an alkoxysilane compound, and a step of carrying out a condensation reaction in the presence of a condensation accelerator comprising a compound of an element belonging to at least one of the groups 4A (excluding Ti), 2B, 3B, and 5B of the periodic table.
Abstract:
A novel modified conjugated diene polymer is obtained by polymerizing a conjugated diene compound with a specified catalyst consisting of components (a)-(c) and then reacting with at least one specified compound selected from the group consisting of components (d)-(l), and has a content of cis-1,4-bond of not less than 85% and a ratio of weight average molecular weight to number average molecular weight of not more than 4. And also, a rubber composition comprises the modified conjugated diene polymer a rubber ingredient.
Abstract:
A method for producing a modified conjugated diene polymer includes a step (A) carrying out a primary modification reaction that reacts a heterocumulene compound having two or more specific functional groups with a conjugated diene polymer having a vinyl content of below 10% and a cis-1,4-bond content of 75% or more and possessing an active end to obtain a primary-modified conjugated diene polymer, and a step (B) carrying out a secondary modification reaction that reacts an active hydrogen-containing compound that includes one or more functional groups selected from the group consisting of an amino group, an imino group, a mercapto group, and a hydroxyl group with the primary-modified conjugated diene polymer to obtain a secondary-modified conjugated diene polymer. The method can produce a modified conjugated diene polymer that exhibits low heat build-up (low fuel consumption) and excellent wear resistance.
Abstract:
Disclosed are a method for producing a modified conjugated diene polymer improved in quality stability, more enhanced in low heat buildup and reinforcing ability when used in a rubber composition, excellent in wear resistance, mechanical characteristics and processability, and improved in cold flow; and a rubber composition using the same. The method includes a step of modifying an active end of an active end-containing conjugated diene polymer having a cis-1,4-bond content of 75% or more with an alkoxysilane compound containing at least one functional group selected from the group consisting of (a) an epoxy group, (b) an isocyanate group and (c) a carboxyl group, and a step of adding a condensation accelerator to conduct condensation reaction of the alkoxysilane compound (residue) in an aqueous solution having a pH of 9 to 14 and a temperature of 85 to 180° C.
Abstract:
A process for simply and inexpensively producing a conjugated diene polymer with a narrow molecular weight distribution and a high cis-bond content at a low cost is provided. The process comprises a polymerization step, wherein a conjugated diene polymer having a cis-1,4-bond content of 98.5 mass % or more and a ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) measured by gel permeation chromatography of 2.5 or less is obtained by carrying out a polymerization reaction in conjugated diene compounds using a catalyst composition containing a rare earth element-containing compound or a reaction product of the rare earth element-containing compound with a Lewis base, an aluminoxane and/or organoaluminum compound, and an iodine-containing compound.
Abstract:
A method for producing a modified conjugated diene polymer includes a modification step (A) that subjects a conjugated diene polymer having a cis-1,4-bond content of 98.5% or more and possessing an active end to a modification reaction to introduce an alkoxysilane compound having two or more reactive groups including an alkoxysilyl group into the active end of the conjugated diene polymer, and a condensation step (B) that subjects the residue of the alkoxysilane compound introduced into the active end to a condensation reaction in the presence of a condensation catalyst that includes at least one element among the elements of the groups 4A, 2B, 3B, 4B, and 5B in the periodic table. The method can produce a modified conjugated diene polymer that exhibits low heat build-up and excellent wear resistance.
Abstract:
A rubber composition from which a vulcanized rubber suitable for producing, for example, a pneumatic tire having excellent abrasion resistance, breaking strength, rolling resistance, wet skid resistance, and the like can be prepared. The rubber composition comprises a rubber component (A) comprising a diene rubber comprising 20 mass % or more of a modified styrene-butadiene copolymer (a1) and 5 mass % or more of a modified conjugated diene polymer (a2), and a filler (B), wherein the modified conjugated diene polymer (a2) is a conjugated diene polymer obtained by modifying the active terminals of a conjugated diene polymer having a cis-1,4 bond content of 80% or higher, with an alkoxysilane compound, and the filler (B) comprises at least either of 2 to 100 mass parts, relative to 100 mass parts of the rubber component (A), of carbon black (b1) and 30 to 100 mass parts, relative to 100 mass parts of the rubber component (A), of silica (b2).