A propylene/1-hexene copolymer having i) the content of 1-hexene derived units, measured by C.sup.13-NMR, ranging from 1.5 wt % to 2.5 wt % and the content of propylene derived units ranging from 97.5 to 98.5 wt. %; ii) a melting temperature, measured by DSC, ranging from 148 to 153° C.; iii) an amount of fraction insoluble in xylene at 25° C. higher than 97.0%; and iv) a melt flow rate (MFR), measured according to ISO 1133, 230° C., 2.16 kg, ranging from 35 to 65 g/10 min.

A propylene/1-hexene copolymer having i) the content of 1-hexene derived units, measured by C.sup.13-NMR, ranging from 1.5 wt % to 2.5 wt % and the content of propylene derived units ranging from 97.5 to 98.5 wt. %; ii) a melting temperature, measured by DSC, ranging from 148 to 153° C.; iii) an amount of fraction insoluble in xylene at 25° C. higher than 97.0%; and iv) a melt flow rate (MFR), measured according to ISO 1133, 230° C., 2.16 kg, ranging from 35 to 65 g/10 min.

To provide a modified vinylaromatic copolymer which can be used in production of copolymer rubber and which has reactivity and solubility, and a copolymer rubber material obtained therefrom, which simultaneously has processability, strength, and homogeneity. The modified vinylaromatic copolymer is a copolymer containing a structural unit (a) derived from a divinylaromatic compound and a structural unit (b) derived from a monovinylaromatic compound, wherein the structural unit (a) at least partially includes the following crosslinked structural unit (a1), and a terminal is modified by a modification group having at least one functional group selected from the group consisting of an amino group, a hydroxyl group, and an alkoxysilyl group.

To provide a modified vinylaromatic copolymer which can be used in production of copolymer rubber and which has reactivity and solubility, and a copolymer rubber material obtained therefrom, which simultaneously has processability, strength, and homogeneity. The modified vinylaromatic copolymer is a copolymer containing a structural unit (a) derived from a divinylaromatic compound and a structural unit (b) derived from a monovinylaromatic compound, wherein the structural unit (a) at least partially includes the following crosslinked structural unit (a1), and a terminal is modified by a modification group having at least one functional group selected from the group consisting of an amino group, a hydroxyl group, and an alkoxysilyl group.

To provide a modified vinylaromatic copolymer which can be used in production of copolymer rubber and which has reactivity and solubility, and a copolymer rubber material obtained therefrom, which simultaneously has processability, strength, and homogeneity. The modified vinylaromatic copolymer is a copolymer containing a structural unit (a) derived from a divinylaromatic compound and a structural unit (b) derived from a monovinylaromatic compound, wherein the structural unit (a) at least partially includes the following crosslinked structural unit (a1), and a terminal is modified by a modification group having at least one functional group selected from the group consisting of an amino group, a hydroxyl group, and an alkoxysilyl group.

Embodiments are directed towards a use of a supported gas-phase biphenylphenol polymerization catalyst to make a polymer via a gas-phase polymerization process, wherein the supported gas-phase biphenylphenol polymerization catalyst is made from a gas-phase biphenylphenol polymerization precatalyst of Formula I.

Embodiments are directed towards a use of a supported gas-phase biphenylphenol polymerization catalyst to make a polymer via a gas-phase polymerization process, wherein the supported gas-phase biphenylphenol polymerization catalyst is made from a gas-phase biphenylphenol polymerization precatalyst of Formula I.

The present invention relates to a novel ligand compound, a transition metal compound and a catalyst composition comprising the same. The novel ligand compound and the transition metal compound of the present invention may be useful as a catalyst of polymerization reaction for preparing an olefin-based polymer having a low density.

The present invention relates to a novel ligand compound, a transition metal compound and a catalyst composition comprising the same. The novel ligand compound and the transition metal compound of the present invention may be useful as a catalyst of polymerization reaction for preparing an olefin-based polymer having a low density.

Provided are a pellet-type polyethylene resin composition capable of improving pipe pressure resistance property, dimensional stability, and processability at the same time, and a method of preparing the same.