Provided are an ethylene-propylene-diene monomer (EPDM) copolymer and a method of preparing the same. An EPDM copolymer which has more improved miscibility with inorganic fillers such as carbon black, may further facilitate dispersibility in mixing to further decrease the viscosity of a compound composition, and may provide a compound composition having excellent processability and mechanical properties. A method of preparing the same is also provided.

The present invention relates to an olefin-based polymer, which has (1) a density (d) ranging from 0.850 to 0.865 g/cc, (2) a melt index (MI, 190° C., 2.16 kg load conditions) ranging from 0.1 g/10 min to 3.0 g/10 min, and (3) a soluble fraction (SF) of 10 wt % or more at −20° C. in cross-fractionation chromatography (CFC), in which a weight average molecular weight (Mw) of the soluble fraction is in a range of 50,000 g/mol to 500,000 g/mol. The olefin-based polymer according to the present invention exhibits improved anti-blocking properties as a low-density olefin-based polymer.

The present invention relates to an olefin-based polymer, which has (1) a density (d) ranging from 0.850 to 0.865 g/cc, (2) a melt index (MI, 190° C., 2.16 kg load conditions) ranging from 0.1 g/10 min to 3.0 g/10 min, and (3) a soluble fraction (SF) of 10 wt % or more at −20° C. in cross-fractionation chromatography (CFC), in which a weight average molecular weight (Mw) of the soluble fraction is in a range of 50,000 g/mol to 500,000 g/mol. The olefin-based polymer according to the present invention exhibits improved anti-blocking properties as a low-density olefin-based polymer.

A method can be used for manufacturing an ethylene-propylene-diene terpolymer for a fuel cell. A polymerization step includes subjecting an organic chelate compound forming a coordinate bond, a vanadium-based Ziegler-Natta catalyst, an organoaluminum compound, and ethylene, propylene, and diene monomers, together with a solvent, to polymerization in a reactor. A separation step includes recovering residual catalysts and unreacted monomers from the stream discharged from the reactor. An acquisition step includes recovering the solvent from the stream deprived of the residual catalysts and unreacted monomers to acquire the ethylene-propylene-diene terpolymer.

A method can be used for manufacturing an ethylene-propylene-diene terpolymer for a fuel cell. A polymerization step includes subjecting an organic chelate compound forming a coordinate bond, a vanadium-based Ziegler-Natta catalyst, an organoaluminum compound, and ethylene, propylene, and diene monomers, together with a solvent, to polymerization in a reactor. A separation step includes recovering residual catalysts and unreacted monomers from the stream discharged from the reactor. An acquisition step includes recovering the solvent from the stream deprived of the residual catalysts and unreacted monomers to acquire the ethylene-propylene-diene terpolymer.

The purpose of the present invention is to obtain an ethylene⋅α-olefin⋅non-conjugated polyene copolymer that has a low permanent compression set at low temperatures, is flexible, and has an excellent balance of rubber elasticity at low temperatures and tensile strength at normal temperatures. This ethylene-based polymer is an ethylene⋅α-olefin⋅non-conjugated polyene copolymer that includes units derived from ethylene (A), units derived from an α-olefin (B) containing 4-20 carbon atoms, and units derived from a non-conjugated polyene (C) and satisfies (1)-(4). (1) The molar ratio of (A) to (B) is 40/60-90/10, (2) the contained amount of the units derived from (C) is 0.1-6.0 mol %, (3) ML.sub.(1+4)125° C. is 5-100, and (4) the B value is 1.20 or more.

The purpose of the present invention is to obtain an ethylene⋅α-olefin⋅non-conjugated polyene copolymer that has a low permanent compression set at low temperatures, is flexible, and has an excellent balance of rubber elasticity at low temperatures and tensile strength at normal temperatures. This ethylene-based polymer is an ethylene⋅α-olefin⋅non-conjugated polyene copolymer that includes units derived from ethylene (A), units derived from an α-olefin (B) containing 4-20 carbon atoms, and units derived from a non-conjugated polyene (C) and satisfies (1)-(4). (1) The molar ratio of (A) to (B) is 40/60-90/10, (2) the contained amount of the units derived from (C) is 0.1-6.0 mol %, (3) ML.sub.(1+4)125° C. is 5-100, and (4) the B value is 1.20 or more.

The purpose of the present invention is to obtain an ethylene⋅α-olefin⋅non-conjugated polyene copolymer that has a low permanent compression set at low temperatures, is flexible, and has an excellent balance of rubber elasticity at low temperatures and tensile strength at normal temperatures. This ethylene-based polymer is an ethylene⋅α-olefin⋅non-conjugated polyene copolymer that includes units derived from ethylene (A), units derived from an α-olefin (B) containing 4-20 carbon atoms, and units derived from a non-conjugated polyene (C) and satisfies (1)-(4). (1) The molar ratio of (A) to (B) is 40/60-90/10, (2) the contained amount of the units derived from (C) is 0.1-6.0 mol %, (3) ML.sub.(1+4)125° C. is 5-100, and (4) the B value is 1.20 or more.

The present invention provides a crosslinked molded article having a lower compression set; and a method for producing a crosslinked molded article by injection molding, the method enabling shortening of one cycle in injection molding, the method being suitable for obtaining a crosslinked molded article having a lower compression set. The present invention relates to a method for producing a crosslinked molded article, comprising melt-kneading a polymer composition containing a polymer having a terminal double bond, a hydrosilyl group-containing compound (Y) having at least two hydrosilyl groups per molecule, a platinum-based catalyst (Z) for hydrosilicon crosslinking, and a reaction inhibitor (D), subjecting the polymer composition to injection molding in a mold, performing primary crosslinking in the mold, removing the primary-crosslinked molded article from the mold, and then performing secondary crosslinking in a heat medium.

The present invention provides a crosslinked molded article having a lower compression set; and a method for producing a crosslinked molded article by injection molding, the method enabling shortening of one cycle in injection molding, the method being suitable for obtaining a crosslinked molded article having a lower compression set. The present invention relates to a method for producing a crosslinked molded article, comprising melt-kneading a polymer composition containing a polymer having a terminal double bond, a hydrosilyl group-containing compound (Y) having at least two hydrosilyl groups per molecule, a platinum-based catalyst (Z) for hydrosilicon crosslinking, and a reaction inhibitor (D), subjecting the polymer composition to injection molding in a mold, performing primary crosslinking in the mold, removing the primary-crosslinked molded article from the mold, and then performing secondary crosslinking in a heat medium.