The present invention provides a nitrile group-containing highly saturated copolymer rubber comprising an α,β-ethylenically unsaturated nitrile monomer unit in a content of 15 wt % or more and less than 28 wt %, an α,β-ethylenically unsaturated monocarboxylic acid ester monomer unit (b) in a content of 10 to 50 wt %, and a conjugated diene monomer unit (c) in a content of 22 to 75 wt %, and having an iodine value of 120 or less, wherein the conjugated diene monomer unit (c) is at least partially hydrogenated, and a proportion of an isoprene unit in the conjugated diene monomer unit (c) is 33 wt % or more.

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.

The present invention relates to a hydrocarbon resin production method comprising thermal polymerization under non-catalytic conditions, thereby enabling a narrow molecular weight distribution and the realization of uniform physical properties. Specifically, the present invention relates to a hydrocarbon resin production method and a hydrocarbon resin produced thereby, the method comprising thermal polymerization without a catalyst and an initiator, thereby enabling, by a low polydispersity index, a narrow molecular weight distribution, and thus a hydrocarbon resin having uniform physical properties.

A catalyst composition capable of forming a conjugated diene-based polymer having a narrow molecular weight distribution by being used in polymerization of a conjugated diene-based monomer, a method of preparing the same, a method of preparing a conjugated diene-based polymer using the catalyst composition, and a conjugated diene-based polymer prepared by the method of preparing the polymer are provided. Since the catalyst composition according to the present invention includes a polymer having a number-average molecular weight of 3,000 g/mol to 10,000 g/mol and including a conjugated diene-based monomer-derived unit, the catalyst composition may be used in the polymerization of a conjugated diene-based monomer to prepare a conjugated diene-based polymer having a narrower molecular weight distribution in comparison to a conventional neodymium catalyst composition.

A copolymer of a 1,3-diene and of an olefin selected from the group consisting of α-monoolefins, ethylene and mixtures thereof is provided. The copolymer bears, at one of its chain ends, an alkoxysilyl or silanol function, functional group F.sup.1, and the copolymer is different from a copolymer of a 1,3-diene and a vinylaromatic monomer.

A process to produce a branched ethylene-α-olefin diene elastomer comprising combining a catalyst precursor and an activator with a feed comprising ethylene, C3 to C12 α-olefins, and a dual-polymerizable diene to obtain a branched ethylene-α-olefin diene elastomer; where the catalyst precursor is selected from pyridyldiamide and quinolinyldiamido transition metal complexes. The branched ethylene-α-olefin diene elastomer may comprise within a range from 40 to 80 wt % of ethylene-derived units by weight of the branched ethylene-α-olefin diene elastomer, and 0.1 to 2 wt % of singly-polymerizable diene derived units, 0.1 to 2 wt % of singly-polymerizable diene derived units, and the remainder comprising C3 to C12 α-olefin derived units, wherein the branched ethylene-α-olefin diene elastomer has a weight average molecular weight (M.sub.w) within a range from 100 kg/mole to 300 kg/mole, an average branching index (g′.sub.avg) of 0.9 or more, and a branching index at very high M.sub.w (g′.sub.1000) of less than 0.9.

A process to produce a branched ethylene-α-olefin diene elastomer comprising combining a catalyst precursor and an activator with a feed comprising ethylene, C3 to C12 α-olefins, and a dual-polymerizable diene to obtain a branched ethylene-α-olefin diene elastomer; where the catalyst precursor is selected from pyridyldiamide and quinolinyldiamido transition metal complexes. The branched ethylene-α-olefin diene elastomer may comprise within a range from 40 to 80 wt % of ethylene-derived units by weight of the branched ethylene-α-olefin diene elastomer, and 0.1 to 2 wt % of singly-polymerizable diene derived units, 0.1 to 2 wt % of singly-polymerizable diene derived units, and the remainder comprising C3 to C12 α-olefin derived units, wherein the branched ethylene-α-olefin diene elastomer has a weight average molecular weight (M.sub.w) within a range from 100 kg/mole to 300 kg/mole, an average branching index (g′.sub.avg) of 0.9 or more, and a branching index at very high M.sub.w (g′.sub.1000) of less than 0.9.

The present disclosure relates to a photosensitive composition comprising a photoinitiator and a bismaleimide component, photopolymers comprising the photosensitive composition and their use, especially in electronic devices. The bismaleimide component includes a bismaleimide compound or a bismaleimide oligomer.

The present disclosure relates to a photosensitive composition comprising a photoinitiator and a bismaleimide component, photopolymers comprising the photosensitive composition and their use, especially in electronic devices. The bismaleimide component includes a bismaleimide compound or a bismaleimide oligomer.

The present disclosure relates to a photosensitive composition comprising a photoinitiator and a bismaleimide component, photopolymers comprising the photosensitive composition and their use, especially in electronic devices. The bismaleimide component includes a bismaleimide compound or a bismaleimide oligomer.