Abstract: The present invention aims to provide rubber compositions and tires which provide improved overall performance in terms of wet grip performance, dry grip performance, and fuel economy. The present invention relates to a rubber composition having a hardness that reversibly changes with water and satisfying the following relationships (1) and (2): Hardness when dry?Hardness when water-wet?1??(1) wherein each hardness represents the JIS-A hardness at 25° C. of the rubber composition; and tan ? at 70° C. when dry<0.14??(2) wherein the tan ? at 70° C. represents the loss tangent measured at 70° C., an initial strain of 10%, a dynamic strain of 2%, and a frequency of 10 Hz.

Abstract: Disclosed herein are styrene butadiene rubber latex compositions with high solids content and methods for making and using these compositions. The method for making the styrene butadiene rubber latex compositions can include mixing a seed, a styrene, an initiator, a base, a surfactant, and a solvent; adding a first portion of 1,3-butadiene to make a first reaction mixture; heating the first reaction mixture for a first reaction time to make a first styrene butadiene rubber latex; mixing the first styrene butadiene rubber latex, a styrene, a base, an initiator, a surfactant, and a solvent; adding a second portion of 1,3-butadiene to make a second reaction mixture; and heating the second reaction mixture for a second reaction time to make a second styrene butadiene rubber latex, where the second styrene butadiene rubber latex has a solids content higher than that of the first styrene butadiene rubber latex.

Abstract: Disclosed herein are styrene butadiene rubber latex compositions with high solids content and methods for making and using these compositions. The method for making the styrene butadiene rubber latex compositions can include mixing a seed, a styrene, an initiator, a base, a surfactant, and a solvent; adding a first portion of 1,3-butadiene to make a first reaction mixture; heating the first reaction mixture for a first reaction time to make a first styrene butadiene rubber latex; mixing the first styrene butadiene rubber latex, a styrene, a base, an initiator, a surfactant, and a solvent; adding a second portion of 1,3-butadiene to make a second reaction mixture; and heating the second reaction mixture for a second reaction time to make a second styrene butadiene rubber latex, where the second styrene butadiene rubber latex has a solids content higher than that of the first styrene butadiene rubber latex.

Abstract: According to an embodiment of the present invention, provided are hollow particles which have a wall portion containing polyurethane or polyurea, have an internal porous structure, and have a plurality of opening spaces blocked by the wall portion in an outermost portion of the porous structure, and a manufacturing method thereof, and a pore forming material, particles for cosmetics, and a weight reducing material.

Abstract: According to an embodiment of the present invention, provided are hollow particles which have a wall portion containing polyurethane or polyurea, have an internal porous structure, and have a plurality of opening spaces blocked by the wall portion in an outermost portion of the porous structure, and a manufacturing method thereof, and a pore forming material, particles for cosmetics, and a weight reducing material.

Abstract: It has been found that carboxylic acid functionalized high cis-1,4-polybutadiene rubber which is comprised of polybutadiene rubber chains having a cis-1,4-microstructure content of at least 90 percent has much better interaction with metal salts of ?,?-ethylenically unsaturated carboxylic acids, such as zinc diacrylate or zinc dimethacrylate. This results in such rubber compositions being stiff while still exhibiting a lower level of hysteresis. These characteristics are beneficial when used in manufacturing tire apex compositions, in manufacturing golf ball cores, and in a wide variety of other applications. Such rubber compositions can be used as substitutes for thermoplastic elastomers in many applications.

Abstract: A process for the preparation of a diene elastomer modified by a 1,3-dipolar compound is provided. The process comprises a thermomechanical kneading of a mixture of a diene elastomer and of a 1,3-dipolar compound in an internal mixer in order to form a modified diene elastomer, followed by an extrusion of the modified diene elastomer.

Abstract: A clear binder, in divided form, that is solid when cold, and to the different ways in which it is formed. Also, the method for transporting and/or storing and/or handling the binder, as well as to the uses of the binder for road and/or industrial applications.

Abstract: A process for the continuous synthesis of a modified diene elastomer comprising at least one silicon atom directly connected to the elastomer chain is provided. The process comprises polymerization by n reactors r1 to rn, considered to be continuous stirred-tank reactors equipped with an internal stirring system and arranged in series, n varying from 2 to 15. The reactor r1 is fed by an input solution comprising a solvent, one or more monomer(s), an anionic polymerization initiator chosen from lithium amides and a polar agent. The temperature of each reactor varies from 20° C. to 150° C. and is greater than or equal to the temperature of the reactor which immediately precedes it. The living diene elastomer obtained exhibits a polydispersity index varying from 1.1 to 1.7. The process further comprises modification of the living diene elastomer obtained in the preceding stage by a functionalization, coupling or star-branching agent.

Abstract: The present invention is directed to a functionalized elastomer comprising the reaction product of a living anionic elastomeric polymer and a polymerization terminator of formula I where X is Cl, Br, or I; m is an integer from 0 to 2, n is an integer from 1 to 3, with the proviso that n+m=3; R1, R2 are independently C1 to C18 alkyl, aryl, or a combination thereof, or R1, R2 are independently —SiR3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R1 and R2 taken together with their common nitrogen atom and optionally a sulfur or oxygen heteroatom to form a five to eight membered ring; R3 is hydrogen, or C1 to C18 alkyl, aryl, or a combination thereof, or R3 is —SiR3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R3 is -R6-R7, where R6 is C1 to C3 alkanediyl and R7 is selected from the following structures —S—Z, —N(R8)(R9), —O(Y), or Si(OR10)3, where R8 and R9 are independently C1 to C18 alkyl, aryl, or a combination thereof, Y and Z are independently s

Abstract: The present invention is directed to a functionalized elastomer comprising the reaction product of a living anionic elastomeric polymer and a polymerization terminator of formula I where X is Cl, Br, or I; m is an integer from 0 to 2, n is an integer from 1 to 3, with the proviso that n+m=3; R1, R2 are independently C1 to C18 alkyl, aryl, or a combination thereof, or R1, R2 are independently —SiR3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R1 and R2 taken together with their common nitrogen atom and optionally a sulfur or oxygen heteroatom to form a five to eight membered ring; R3 is hydrogen, or C1 to C18 alkyl, aryl, or a combination thereof, or R3 is —SiR3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R3 is —R6—R7, where R6 is C1 to C3 alkanediyl and R7 is selected from the following structures —S—Z, —N(R8)(R9), —O(Y), or Si(OR10)3, where R8 and R9 are independently C1 to C18 alkyl, aryl, or a combination thereof, Y and Z are independently s

Abstract: A process for the continuous synthesis of a diene elastomer is provided. The synthesis is conducted by means of n reactors r1 to rn, considered to be continuous stirred-tank reactors, which are equipped with an internal stirring system. The reactors are arranged in series, n varying from 2 to 15, preferably from 2 to 9. The reactor r1 is fed by an input solution comprising a solvent, one or more monomer(s), an anionic polymerization initiator chosen from lithium amides and a polar agent. The conversion by weight C1 in the first reactor is less than 70%, and the total conversion by weight Cn at the outlet of the reactor rn is greater than or equal to 70%.

Abstract: The invention relates to a sulfur-crosslinkable rubber mixture comprising a rubber blend composed of at least one solution-polymerized diene polymer A of high molecular weight and at least one solution-polymerized polymer B of low molecular weight, wherein at least one of polymers A and B has been functionalized at the chain end and/or along the polymer chain and/or at a coupling site with at least one group selected from epoxy groups, hydroxyl groups, carboxyl groups, silane sulfide groups, amino groups, siloxane groups, organosilicon groups, phthalocyanine groups and amino group-containing alkoxysilyl groups, and as filler at least one silica and/or at least one carbon black in an amount of 25 to 300 phr, wherein the ratio of carbon black to silica in the mixture is 100:0 to 3:97.

Abstract: The invention relates to a rubber blend, to a sulfur-crosslinkable rubber mixture comprising the rubber blend and to a vehicle tire comprising such a rubber mixture. The rubber blend comprises at least one solution-polymerized diene polymer A of high molecular weight and at least one solution-polymerized polymer B of low molecular weight, wherein at least one of polymers A and B has been functionalized at the chain end and/or along the polymer chain and/or at a coupling site with at least one group selected from epoxy groups, hydroxyl groups, carboxyl groups, silane sulfide groups, amino groups, siloxane groups, organosilicon groups, phthalocyanine groups and amino group-containing alkoxysilyl groups and wherein the rubber blend includes 35 to 100 phr (based on the at least one solution-polymerized diene polymer A of high molecular weight), preferably 35 to 70 phr, of the at least one solution-polymerized polymer B of low molecular weight.

Abstract: A thermoplastic composition includes from about 50 wt. % to about 90 wt. % of a polymeric base resin and from about 10 wt. % to about 50 wt. % of a low dielectric constant (Dk)/low dissipation factor (Df) glass fiber component. The low Dk/low Df glass fiber component has a Dk of less than about 5.0 at a frequency of from 1 MHz to 1 GHz and a Df of less than about 0.002 at a frequency of from 1 MHz to 1 GHz. In certain aspects the thermoplastic composition has a Dk that is at least about 0.1 lower than a substantially identical reference composition that does not include the low Dk/low Df glass fiber component.

Abstract: A thermoplastic composition includes from about 50 wt. % to about 90 wt. % of a polymeric base resin and from about 10 wt. % to about 50 wt. % of a low dielectric constant (Dk)/low dissipation factor (Df) glass fiber component. The low Dk/low Df glass fiber component has a Dk of less than about 5.0 at a frequency of from 1 MHz to 1 GHz and a Df of less than about 0.002 at a frequency of from 1 MHz to 1 GHz. In certain aspects the thermoplastic composition has a Dk that is at least about 0.1 lower than a substantially identical reference composition that does not include the low Dk/low Df glass fiber component.

Abstract: Disclosed herein are terminal-functionalized polymers functionalized with silicon-containing functionalizing agents, rubber compositions including the polymers, methods for improving the cold flow resistance of a polymer, methods for improving the filler dispersion of a silica-filled rubber composition, and processes for preparing the terminal-functionalized polymer.

Abstract: The present invention provides a rubber composition excellent in grip performance, durability of grip performance, and abrasion resistance. Also provided is a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition exhibiting a temperature dependence curve of tan ? with a half-width defined by Equation (1) of 45 or less as measured at a strain of 0.1% and a frequency of 10 Hz, the rubber composition having a temperature dependence of hardness defined by Equation (2) of 4.3 or less, the temperature dependence curve having a peak temperature of 10° C. or lower, half-width=(temperature at half-peak height on high temperature side)?(temperature at half-peak height on low temperature side),??Equation (1): temperature dependence of hardness=(hardness index at 0° C.)/(hardness index at 100° C.).

Abstract: A self-inflating tire assembly includes an air tube mounted within a tire sidewall or chafer groove. The air tube is in contacting engagement with opposite angled groove surfaces surrounding the air tube. A segment of the air tube is flattened from an expanded diameter to a flat diameter by bending and compression of the groove in a rolling tire footprint to force air evacuated from the flattened segment along a tube air passageway. A coverstrip overlays and seals the groove and provides an abrasion resistant surface on the exterior of the tire. The coverstrip is made from a vulcanizable rubber composition comprising from 50 to 80 phr of a polybutadiene, from 50 to 20 phr of natural rubber, and from 0.1 to 5 phr of a vulcanization modifier.

Abstract: The invention relates to compositions of cement and concrete having properties of resistance, modulus and expansion which are significantly improved, using an additive for cement based on thermoplastic styrene-butadiene-styrene (SBS) copolymer in cationic latex, when compared with non-modified cement and concrete references.

Abstract: Disclosed are a modified conjugated diene-based polymer represented by a specific Chemical Formula and a method of preparing the same.

Abstract: Provided is a method for producing a rubber composition that includes a rubber component (A) including natural rubber, at least one filler (B) selected from an inorganic filler and carbon black, and a monohydrazide compound (C) supported on a solid. The monohydrazide compound (C) is represented by general formula (I): R—CONHNH2, where R represents an alkyl group having from 1 to 30 carbon atoms, a cycloalkyl group having from 3 to 30 carbon atoms, or an aryl group. The method comprises compounding in an optional preliminary compounding stage and a plurality of compounding stages, and adding the monohydrazide compound (C) supported on the solid and kneading in the preliminary compounding stage and/or a first compounding stage. Also provided is a rubber composition produced with this method.

Abstract: The method is for separation of lignin from original black liquor (BLIN) that has a first precipitation stage (PR) for precipitation of lignin by a first acidification using acidifier AC1, preferably using CO2, at alkaline conditions, then separating a lignin cake with subsequent suspension of the lignin cake in a strong acid in order to leach our metals from the lignin followed by dewatering and obtaining a clean lignin product LP. The process further is improved by intensified hydrolysis of lignin cake such that most of the carbohydrates are broken down to dissolvable monomers that could be separated from the lignin in the filtrate from a filtering stage subsequent to the hydrolysis. The improved hydrolysis could reduce as much as 90% of the carbohydrate content using a moderately increased temperature and increased charge of acidifier while avoiding any larger lignin yield losses.

Abstract: Provided is a method for producing rubber particles with a reduced coagulation tendency. The present invention relates to a method for producing rubber particles with a reduced coagulation tendency, the method including a step of performing protein synthesis in the presence of both rubber particles and a cell-free protein synthesis solution containing an mRNA coding for a rubber elongation factor (REF) family protein to bind the REF family protein to the rubber particles.

Abstract: Vulcanizates with desirable properties can be obtained from compositions incorporating polymers that include hydroxyl group-containing aryl functionalities, silica or other particulate filler(s) that contain or include oxides of silicon and a group or compound that can act to covalently bond the filler particles and the polymer. The group can be provided as a substituent of the filler particle, or a discreet compound can be provided in the composition.

Abstract: The present invention is directed to a functionalized elastomer comprising the reaction product of a living elastomeric polymer and a polymerization terminator of formula I, wherein the functionalized elastomer comprises repeat units of a diene monomer and optionally a vinyl aromatic monomer, and the functionalized elastomer comprises at least 92 percent by weight of cis 1,4 microstructure content based on the weight of the polydiene content of the functionalized elastomer wherein R1 is C1 to C4 linear alkyl, or C1 to C4 branched alkanediyl; X1, X2, X3 are independently O, S, or a group of formula (II) or (III) where R2 is C1 to C18 linear or branched alkyl; Z is R3, —OR4, or —R5—X4; R3, R4 are independently C1 to C18 linear or branched alkyl; R5 is C1 to C18 alkanediyl or dialkyl ether diyl; X4 is halogen or a group of structure IV, V, VI, VII or VIII wherein R6, R7, R8, R9, and R10 are independently H or C1 to C8 alkyl; R11 is C2 to C8 alkanediyl; R12 and R13 are independen

Abstract: Disclosed are a modified conjugated diene-based polymer represented by specific Chemical Formula and a method of preparing the same.

Abstract: A method of making a polymer with stable Mooney viscosity is described. A conjugated diolefin is reacted in a hydrocarbon solvent in the presence of an initiator to form a polymer. After forming the polymer, alkoxysilane terminal functionalizing groups are bonded to the polymer. An alkoxysilane stabilizing agent is then added to the polymer in the presence of hydrocarbon oil. The polymer is then desolvatized, resulting in a polymer with stable Mooney viscosity, even over prolonged periods of time. Compositions and articles containing the polymer are also described.

Abstract: Provided is a thioester modified polymer, wherein a polymer having an intramolecular double bond is modified with at least one of thiocarboxylic acid and dithiocarboxylic acid. The above thioester modified polymer can be manufactured by allowing a polymer having an intramolecular double bond to react with thiocarboxylic acid, dithiocarboxylic acid or a metal salt thereof, and used to be compounded in a diene-based rubber. When this thioester modified polymer is compounded in a diene-based rubber, in particular a silica containing diene-based rubber, tensile strength and breaking elongation, in particular tensile strength and breaking elongation at a high temperature (100° C.), can be improved without decreasing modulus, hardness, exothermicity and the like. Therefore, the rubber composition having excellent thermal resistance and toughness can be effectively used as a rubber compound for forming a cap tread or a side tread of a pneumatic tire.

Abstract: The deposition of graphene is accomplished by various techniques that result in a change of the graphene's solubility in the liquid medium. The solubility change enables the deposition of the graphene onto the substrate. Once the graphene is deposited onto the substrate, the at least partially coated substrate may be separated from the liquid medium. The substrates may then serve as a carrier to deliver the graphene to a desired application.

Abstract: Disclosed are substantially non-carcinogenic bio oil-derived residue compositions produced from the pyrolysis or thermo catalytic conversion of biomass, and their use as solvents in the production of tires.

Abstract: The present invention is directed to a functionalized elastomer comprising the reaction product of a living anionic elastomeric polymer and a polymerization terminator of formula I wherein R1 is C1 to C4 linear alkyl, or C1 to C4 branched alkanediyl; X1, X2, X3 are independently O, S, or a group of formula (II) or (III) where R2 is C1 to C18 linear or branched alkyl; Z is R3, —OR4, or —R5—X4; R3, R4 are independently C1 to C18 linear or branched alkyl; R5 is C1 to C18 alkanediyl or dialkyl ether diyl; X4 is halogen or a group of structure IV, V, VI, VII or VIII wherein R6, R7, R8, R9, and R10 are independently H or C1 to C8 alkyl; R11 is C2 to C8 alkanediyl; R12 and R13 are independently H, aryl or C1 to C8 alkyl; Q is N or a group of structure IX wherein R14 is C1 to C8 alkyl.

Abstract: A method of making a polymer with stable Mooney viscosity is described. A conjugated diolefin is reacted in a hydrocarbon solvent in the presence of an initiator to form a polymer. After forming the polymer, alkoxysilane terminal functionalizing groups are bonded to the polymer. An alkoxysilane stabilizing agent is then added to the polymer in the presence of hydrocarbon oil. The polymer is then desolvatized, resulting in a polymer with stable Mooney viscosity, even over prolonged periods of time. Compositions and articles containing the polymer are also described.

Abstract: The present invention includes a process for producing treated filler that includes (a) treating a slurry that includes untreated filler where the untreated filler has not been previously dried, with a treating composition that includes a treating agent, thereby forming a treated filler slurry, and (b) drying the treated filler slurry to produce treated filler. The treating agent can include a polymer having (i) at least one first group that interacts with the untreated filler and (ii) at least one second group that interacts with a rubber matrix into which the treated filler is incorporated. The present invention also is directed to treated filler prepared by the process, as well as rubber compounding compositions and tires including the treated filler.

Abstract: The invention concerns an olefinically unsaturated radial styrenic block copolymer having the general formula A-B—Y—(B-A)n wherein each A is independently a polymer block composed of at least 90 mol. % of an alkenyl aromatic hydrocarbon, each B is independently a polymer block composed of at least 90 mol. % of one or more conjugated dienes, Y is the remnant of a coupling agent, and n is an integer from 2 to 5. The invention is also an improved vulcanizer-free latex comprising water and the olefinically unsaturated radial styrenic block copolymer. Moreover, the invention concerns a process for preparing articles by coagulation dipping from the improved latex and dipped goods made from such latex.

Abstract: The present invention relates to a pneumonic tire and a rubber composition used in the same, both of which are capable of preventing static charge build-up on a tire surface without degrading various tire performances such as rolling resistance and so on, and particularly to a rubber composition comprising 10 to 30 parts by mass of an ionic liquid and 5 to 95 parts by mass of silica per 100 parts by mass of a rubber component containing at least 50% by mass of styrene-butadiene rubber, as well as a pneumatic tire using such a rubber composition in a tread portion.

Abstract: This invention relates to a method for producing a modified conjugated diene rubber wherein the method involves: (a) a step in which a conjugated diene polymer having an alkali metal or alkaline earth metal active end and obtained by polymerizing a conjugated diene compound or by polymerizing a conjugated diene compound with an aromatic vinyl compounds is reacted with a first alkoxysilane compound which has an alkoxysilyl group having two or more alkoxy groups and has a group protected by a protecting group wherein deprotection is possible to obtain a modified conjugated-diene polymer having an alkoxysilyl group; and (b) a step in which the modified conjugated-diene polymer is reacted with a second alkoxysilane compound which has an alkoxysilyl group.

Abstract: A polymer has at least the following characteristics: (a) a block styrene content containing 4 to 6 styrene units from about 27 to about 50 weight percent based on total styrene content in the polymer; (b) a vinyl content from about 30 to about 80 weight percent based on total amount of polymerized 1,3-butadiene; and (c) a styrene content from about 40 to about 70 weight percent based on total weight of polymer. Processes for the polymerization of such a polymer, compositions containing such a polymer, and articles containing at least one component formed from such a composition are described.

Abstract: An object of the present invention is to provide a relief printing plate precursor for laser engraving that is excellent in rinsing properties for engraving residue and engraving sensitivity and can give a sharp engraved shape. Disclosed is a relief printing plate precursor for laser engraving comprising a relief-forming layer formed of a resin composition for laser engraving, or a crosslinked relief-forming layer obtained by crosslinking the relief-forming layer formed of the resin composition for laser engraving, wherein the resin composition for laser engraving comprises a binder polymer as Component A, and carbon black of which pH is higher than 6 and an average particle size when being dispersed into water is equal to or less than 500 nm as Component B.

Abstract: The present invention is directed to a self-healing rubber composition comprising a functionalized elastomer comprising: a polymeric backbone chain derived from a monomer comprising at least one conjugated diene monomer and optionally at least one vinyl aromatic monomer; and a functional group bonded to the backbone chain, the functional group comprising a multidentate ligand capable of complexing with a metal ion; and a partitioned metal ion. The invention is further directed to a pneumatic tire comprising the self-healing rubber composition.

Abstract: A method for preparing a functionalized polymer, the method comprising the step of reacting a reactive polymer with a functionalizing agent defined by formula I or formula II: or combinations thereof, where R1, R2, and R3 are each independently a divalent organic group, R4 and R5 are each independently a monovalent organic group, a is an integer from 0 to 1, x is an integer from 0 to 2, y is an integer from 1 to 3, x+y=3, and ? is a protected amino group.

Abstract: A coating composition comprising a hardenable film-former and at least 0.5 weight percent of an oxidizing agent sufficient to decolorize a stain on the film-former is disclosed, wherein the oxidizing agent comprises hydrogen peroxide, hypochlorite, and organo-chlorine bleaches and will at least partially decolorize a plurality of stains when applied to the hardened coating, allowed to stand for one hour at room temperature, and evaluated by visual observation of the stain under average overhead fluorescent illumination. The oxidizing agent is not consumed as a catalyst or initiator to polymerize or otherwise cause a reaction in the floor coating before it is applied and before it has hardened. A composition of the invention may include from about 0.8 to about 5 weight percent oxidizing agent and the film-former forms a hardened film resistant to rinsing with tap water.

Abstract: Styrene-acrylic dispersants for use in pigment dispersions have lower viscosities than benchmark formulations such as nitrocellulose, dimer-acid based polyamides, and thermoplastic polyurethanes, prepared under otherwise identical conditions. Lower viscosities allow for the preparation of similarly viscous dispersions and inks with the styrene-acrylics when compared to traditional dispersants, at either (a) lower solvent levels, or if solvent levels are to be maintained, (b) higher pigment and solids loadings.

Abstract: For a tire excellent in strength, low-heat buildup property, wet grip property, and driveability, and a rubber composition and a conjugated diene rubber for the tire, a conjugated diene rubber of the present invention includes 5 wt % or more of a structure that 3 or more conjugated diene polymer chains are bound via a denaturing agent, obtained by reaction of each chain and the agent, each chain being that at least one of terminals is an isoprene block having 70 wt % or more of an isoprene monomer unit, and the other is an active terminal, the agent having, per molecule, at least one of an epoxy group(s) and a hydrocarbyloxysilyl group(s), and being that a total number of the epoxy group(s) and hydrocarbyloxy groups in the hydrocarbyloxysilyl group(s) per molecule is 3 or more.

Abstract: A rubber composition that can be used in applications such as automotive tires and can improve the fuel efficiency performance and driving stability of automobiles and the like, a method for producing a rubber composition, and a tire using the same are provided.

Abstract: The present invention provides a rubber composition comprising, as blended, a rubber component (A), an amino acid derivative (B) and a filler containing an inorganic filler (C), and further containing, as incorporated therein, at least one selected from sulfur and a sulfur compound. The vulcanization rate of the rubber composition is accelerated and the low-heat-generation property thereof is excellent.

Abstract: A conjugated diene rubber of the present invention is prepared from conjugated diene polymer chains, wherein the conjugated diene polymer chains each has an active end at one end and an isoprene block at least at the other end, the isoprene block contains 70 wt % or more isoprene monomer units, and the active ends of at least part of the conjugated diene polymer chains are modified with a compound having a >C?O group as a functional group. This provides (i) a tire that has an excellent strength, excellent low-heat buildup property, and excellent wet grip property and (ii) a rubber composition and a conjugated diene rubber that are suitably used to produce the tire.

Abstract: The present invention related to a method for producing a modified conjugated diene-based polymer, the method comprising a step of reacting a conjugated diene-based polymer with an organometallic compound, and a step of reacting the resulting product and a compound containing a nitrogen atom and a carbonyl group.

Abstract: A polymer having at least the following characteristics: (a) a block styrene content with more than 4 consecutive styrene units from about 40 to about 70 weight percent based on total styrene content in the polymer; (b) a vinyl content from about 25 to about 80 weight percent based on total amount of polymerized 1,3-diene; (c) a styrene content from about 20 to about 75 weight percent based on total weight of polymer; and (d) a molecular weight distribution (Mw/Mn) of 1.5 or less.

Abstract: A polymer having at least the following characteristics: (a) a block styrene content with more than 6 consecutive styrene units from about 15 to about 35 weight percent based on total styrene content in the polymer; (b) a vinyl content from about 25 to about 80 weight percent based on total amount of polymerized 1,3-diene; and (c) a styrene content from about 35 to about 75 weight percent based on total weight of polymer; and (d) a molecular weight distribution (Mw/Mn) of 1.5 or less.