Provided is a hydrogenated block copolymer, which is a hydrogenation product of a block copolymer including a polymer block (A) containing more than 70 mol % of a structural unit derived from an aromatic vinyl compound and a polymer block (B) containing 30 mol % or more of a structural unit derived from at least one selected from the group consisting of a conjugated diene compound and isobutylene, the hydrogenated block copolymer being satisfied with the following requirements (1) and (2): Requirement (1): the content of the polymer block (A) in the block copolymer is 1 to 30% by mass; and Requirement (2): when the polymer block (B) is regarded as having a structure with a hydrogenation rate of 100 mol %, an average value of a methylene chain length of a main chain of the structural unit derived from at least one selected from the group consisting of a conjugated diene compound and isobutylene is 1.0 to 6.0.

Provided is a hydrogenated block copolymer, which is a hydrogenation product of a block copolymer including a polymer block (A) containing more than 70 mol % of a structural unit derived from an aromatic vinyl compound and a polymer block (B) containing 30 mol % or more of a structural unit derived from at least one selected from the group consisting of a conjugated diene compound and isobutylene, the hydrogenated block copolymer being satisfied with the following requirements (1) and (2): Requirement (1): the content of the polymer block (A) in the block copolymer is 1 to 30% by mass; and Requirement (2): when the polymer block (B) is regarded as having a structure with a hydrogenation rate of 100 mol %, an average value of a methylene chain length of a main chain of the structural unit derived from at least one selected from the group consisting of a conjugated diene compound and isobutylene is 1.0 to 6.0.

Provided is a hydrogenated block copolymer, which is a hydrogenation product of a block copolymer including a polymer block (A) containing more than 70 mol % of a structural unit derived from an aromatic vinyl compound and a polymer block (B) containing 30 mol % or more of a structural unit derived from at least one selected from the group consisting of a conjugated diene compound and isobutylene, the hydrogenated block copolymer being satisfied with the following requirements (1) and (2): Requirement (1): the content of the polymer block (A) in the block copolymer is 1 to 30% by mass; and Requirement (2): when the polymer block (B) is regarded as having a structure with a hydrogenation rate of 100 mol %, an average value of a methylene chain length of a main chain of the structural unit derived from at least one selected from the group consisting of a conjugated diene compound and isobutylene is 1.0 to 6.0.

Polar modifier systems based on a blend of DTHFP, ETE, TMEDA, DMTHFMA and/or functionally similar compounds with BDMAEE and SMT are used to make block copolymers having high levels of pendant vinyl double bond repeat units, which is through highly selective 1,2-bond butadiene addition, low vinylcyclopentane formation, unimodal narrow molecular weight distribution, and a low level of randomized co-monomer repeat units. The block copolymers have very high levels of 1,2-vinyl content and high 3,4-vinyl bond addition of the conjugated diene monomer and low vinylcyclopentane content. The polar modifier systems provide a fast polymerization rate, with a unimodal narrow molecular weight distribution. The polar modifier systems allow operation at a higher temperature than in prior art systems, which reduces cooling requirements.

Polar modifier systems based on a blend of DTHFP, ETE, TMEDA, DMTHFMA and/or functionally similar compounds with BDMAEE and SMT are used to make block copolymers having high levels of pendant vinyl double bond repeat units, which is through highly selective 1,2-bond butadiene addition, low vinylcyclopentane formation, unimodal narrow molecular weight distribution, and a low level of randomized co-monomer repeat units. The block copolymers have very high levels of 1,2-vinyl content and high 3,4-vinyl bond addition of the conjugated diene monomer and low vinylcyclopentane content. The polar modifier systems provide a fast polymerization rate, with a unimodal narrow molecular weight distribution. The polar modifier systems allow operation at a higher temperature than in prior art systems, which reduces cooling requirements.

A nitrile-group-containing copolymer rubber, including 15% by weight or more and less than 28% by weight of α,β-ethylenically unsaturated nitrile monomer units (a), 10 to 50% by weight of α,β-ethylenically unsaturated monocarboxylic acid ester monomer units (b), 22 to 74% by weight of conjugated diene monomer units (c), and 1 to 10% by weight of carboxyl group-containing monomer units (d) and having an iodine value of 120 or less, wherein the conjugated diene monomer units (c) are at least partially hydrogenated, and the proportion of isoprene units in the conjugated diene monomer units (c) is 5% by weight or more and less than 33% by weight.

A nitrile-group-containing copolymer rubber, including 15% by weight or more and less than 28% by weight of α,β-ethylenically unsaturated nitrile monomer units (a), 10 to 50% by weight of α,β-ethylenically unsaturated monocarboxylic acid ester monomer units (b), 22 to 74% by weight of conjugated diene monomer units (c), and 1 to 10% by weight of carboxyl group-containing monomer units (d) and having an iodine value of 120 or less, wherein the conjugated diene monomer units (c) are at least partially hydrogenated, and the proportion of isoprene units in the conjugated diene monomer units (c) is 5% by weight or more and less than 33% by weight.

Provided are a paste for a secondary battery, and method of producing the same, with which it is possible to produce an electrode that can reduce internal resistance of a secondary battery and that can cause the secondary battery to display excellent cycle characteristics. The paste for a secondary battery contains a conductive additive, a polymer, and a dispersion medium. The conductive additive includes one or more carbon nanotubes having a surface base content of not less than 0.01 mmol/g and not more than 0.10 mmol/g and a ratio of surface acid content relative to the surface base content of not less than 0.1 and not more than 1.0.

Provided are a paste for a secondary battery, and method of producing the same, with which it is possible to produce an electrode that can reduce internal resistance of a secondary battery and that can cause the secondary battery to display excellent cycle characteristics. The paste for a secondary battery contains a conductive additive, a polymer, and a dispersion medium. The conductive additive includes one or more carbon nanotubes having a surface base content of not less than 0.01 mmol/g and not more than 0.10 mmol/g and a ratio of surface acid content relative to the surface base content of not less than 0.1 and not more than 1.0.

Provided are: a resin composition containing a rubber (I), a block copolymer (II) and a crosslinking agent (III), wherein the ratio by mass of the rubber (I) to the block copolymer (II), (I)/(II) is 99/1 to 55/45, and the block copolymer (II) is a block copolymer containing a polymer block (A) that contains an aromatic vinyl compound-derived structural unit and a polymer block (B) that contains a farnesene-derived structural unit (b1), and a molded article of the resin composition.