Abstract: The purpose of the present invention is to provide a propylene-based block copolymer, the deposition thereof on the inner wall of the polymerization vessel having been sufficiently inhibited. The propylene-based block copolymer of the present invention has a flowability evaluation value of 40% or less, the value being calculated with the following equation wherein X (sec) is the number of seconds over which 100 g of the copolymer having ordinary temperature falls from a stainless-steel funnel having an inner diameter of 11.9 mm and Y (sec) is the number of seconds over which 100 g of the copolymer which has been held at 80° C. for 24 hours under a load of 10 kg falls from the funnel having an inner diameter of 11.9 mm. Flowability evaluation value (%)={(Y/X)?1}×100.

Abstract: The purpose of the present invention is to provide a propylene-based block copolymer, the deposition thereof on the inner wall of the polymerization vessel having been sufficiently inhibited. The propylene-based block copolymer of the present invention has a flowability evaluation value of 40% or less, the value being calculated with the following equation wherein X (sec) is the number of seconds over which 100 g of the copolymer having ordinary temperature falls from a stainless-steel funnel having an inner diameter of 11.9 mm and Y (sec) is the number of seconds over which 100 g of the copolymer which has been held at 80° C. for 24 hours under a load of 10 kg falls from the funnel having an inner diameter of 11.9 mm. Flowability evaluation value (%)={(Y/X)?1}×100.

Abstract: The present invention provides an olefin polymerization catalyst, which is free of polyfunctional aromatic compounds and has a large particle diameter, and a solid titanium component (I) which forms the catalyst.

Abstract: A solid titanium catalyst component (I) comprising titanium, magnesium, halogen, a specific cyclic ester compound (a) and a specific cyclic ester compound (b), an olefin polymerization catalyst containing this catalyst component (I), and an olefin polymerization process using this olefin polymerization catalyst are disclosed. According to the solid titanium catalyst component, the olefin polymerization catalyst and the process for preparing an olefin polymer of the invention, an olefin polymer having high stereoregularity and a wide molecular weight distribution can be prepared with high activity, preparation of an olefin polymer excellent not only in molding properties such as high-speed streatchability and high-speed moldability but also in rigidity becomes possible, and besides, production cost can be reduced.

Abstract: Olefin polymer with narrow molecular weight distribution and specific molecular weight, olefin polymer having functional group introduced at terminal, tapered polymer containing segment wherein monomer composition continuously changes in the polymer chain, olefin polymer having different segments bonded to each other, and process for preparing these polymers. The olefin polymers are polymers of C2-20 carbon atom olefins and have a number-average molecular weight of ?500 and Mw/Mn of ?1.5. In syntheses, an olefin of 2-20 carbon atoms is polymerized in the presence of a catalyst comprising a transition metal compound represented by the formula LmMXn wherein M is a transition metal atom of Group 3-11, m is 1-5, n is a number satisfying a valence of M, L is a ligand—coordinated to the central metal M—which contains a heteroatom having no direct bond to the central metal, and X is e.g. halogen or a hydrocarbon.

Abstract: A solid titanium catalyst component (I) comprising titanium, magnesium, halogen, a specific cyclic ester compound (a) and a specific cyclic ester compound (b), an olefin polymerization catalyst containing this catalyst component (I), and an olefin polymerization process using this olefin polymerization catalyst are disclosed. According to the solid titanium catalyst component, the olefin polymerization catalyst and the process for preparing an olefin polymer of the invention, an olefin polymer having high stereoregularity and a wide molecular weight distribution can be prepared with high activity, preparation of an olefin polymer excellent not only in molding properties such as high-speed streatchability and high-speed moldability but also in rigidity becomes possible, and besides, production cost can be reduced.

Abstract: The present invention provides an olefin polymerization catalyst, which is free of polyfunctional aromatic compounds and has a large particle diameter, and a solid titanium component (I) which forms the catalyst.

Abstract: An ethylene (co)polymer of the present invention is a (co)polymer with excellent moldability and mechanical properties and either an ethylene homopolymer or a copolymer of ethylene and an ?-olefin of 4 to 20 carbon atoms. The (co)polymer has methyl branches measured by 13C-NMR less than 0.1 in number per 1,000 carbon atoms and Mw/Mn measured by GPC not lower than 1.8 and lower than 4.5. The (co)polymer is either an ethylene homopolymer or a copolymer of ethylene and an ?-olefin of 3 to 20 carbon atoms. The melt tension (MT) and the swell ratio (SR) satisfy the relation; log(MT)>12.9?7.15×SR; and the intrinsic viscosity ([?]) and the melt flow rate (MFR) satisfy the relation; [?]>1.85×MFR?0.192 in the case of MFR<1 and the relation; [?]>1.85×MFR?0.213 in the case of MFR?1. Such an ethylene (co)polymer can be usable for various molding applications and especially suitable for pipes.

Abstract: The present invention relates to a solid titanium catalyst component containing magnesium, titanium, halogen and a specific ester compound; a catalyst for olefin polymerization containing the solid titanium catalyst component, an organometallic compound catalyst component and an electron donor where necessary; and a polymerization method of an olefin using the catalyst for olefin polymerization. According to the present invention, an olefin polymer having a high Mw/Mn value which is an index of the molecular weight distribution is obtained, even by a single-stage polymerization. Especially an olefin polymer having a high Mz/Mw which is a high content of high molecular weight components is obtained.

Abstract: The present invention provides an olefin polymer having a narrow molecular weight distribution and a specific molecular weight, an olefin polymer having a functional group introduced at the terminal, a tapered polymer containing a segment wherein monomer composition continuously changes in the polymer chain, an olefin polymer having different segments which are bonded to each other, and a process for preparing these polymers. The olefin polymers of the invention are polymers of olefins of 2 to 20 carbon atoms and have a number-average molecular weight of not less than 500 and Mw/Mn of not more than 1.5.

Abstract: An ethylene (co)polymer of the present invention is a (co)polymer with excellent moldability and mechanical properties and either an ethylene homopolymer or a copolymer of ethylene and an ?-olefin of 4 to 20 carbon atoms. The (co)polymer has methyl branches measured by 13C-NMR less than 0.1 in number per 1,000 carbon atoms and Mw/Mn measured by GPC not lower than 1.8 and lower than 4.5. The (co)polymer is either an ethylene homopolymer or a copolymer of ethylene and an ?-olefin of 3 to 20 carbon atoms. The melt tension (MT) and the swell ratio (SR) satisfy the relation; log(MT)>12.9?7.15×SR; and the intrinsic viscosity ([?]) and the melt flow rate (MFR) satisfy the relation; [?]>1.85×MFR?0.192 in the case of MFR<1 and the relation; [?]>1.85×MFR?0.213 in the case of MFR?1. Such an ethylene (co)polymer can be usable for various molding applications and especially suitable for pipes.

Abstract: The present invention provides an olefin polymer having a narrow molecular weight distribution and a specific molecular weight, an olefin polymer having a functional group introduced at the terminal, a tapered polymer containing a segment wherein monomer composition continuously changes in the polymer chain, an olefin polymer having different segments which are bonded to each other, and a process for preparing these polymers. The olefin polymers of the invention are polymers of olefins of 2 to 20 carbon atoms and have a number-average molecular weight of not less than 500 and Mw/Mn of not more than 1.5.

Abstract: An ethylene (co)polymer of the present invention is a (co)polymer with excellent moldability and mechanical properties and either an ethylene homopolymer or a copolymer of ethylene and an ?-olefin of 4 to 20 carbon atoms. The (co)polymer has methyl branches measured by 13C-NMR less than 0.1 in number per 1,000 carbon atoms and Mw/Mn measured by GPC not lower than 1.8 and lower than 4.5. The (co)polymer is either an ethylene homopolymer or a copolymer of ethylene and an ?-olefin of 3 to 20 carbon atoms. The melt tension (MT) and the swell ratio (SR) satisfy the relation; log(MT)>12.9?7.15×SR; and the intrinsic viscosity ([?]) and the melt flow rate (MFR) satisfy the relation; [?]>1.85×MFR?0.192 in the case of MFR?1 and the relation; [?]>1.85×MFR?0.213 in the case of MFR?1. Such an ethylene (co)polymer can be usable for various molding applications and especially suitable for pipes.

Abstract: The present invention provides a novel olefin polymerization catalyst having excellent olefin polymerization activity and, in polymerization with the catalyst comprising a transition metal compound, a polymerization process for preparing a polymer having a low molecular weight with high polymerization activity. The process comprises polymerizing olefin in the presence of an olefin polymerization catalyst comprising (A) a transition metal compound represented by the following [M: a Group 4 or 5 transition metal atom in the Periodic Table, m: 1–4, R1: H, a C1–C5 linear hydrocarbon group, 3- to 5-membered alicyclic hydrocarbon group, bicycloaliphatic hydrocarbon group wherein two alicyclic rings share one or more carbon atoms, R2 to R6: H, a halogen atom, hydrocarbon group etc, X: H, a halogen atom etc, and n is a valence of M], and (B) at least one compound selected from (B-1) an organometallic compound, (B-2) an organoaluminum oxy compound and (B-3) an ionizing ionic compound.

Abstract: An ethylene (co)polymer of the present invention is a (co)polymer with excellent moldability and mechanical properties and either an ethylene homopolymer or a copolymer of ethylene and an ?-olefin of 4 to 20 carbon atoms. The (co)polymer has methyl branches measured by 13C-NMR less than 0.1 in number per 1,000 carbon atoms and Mw/Mn measured by GPC not lower than 1.8 and lower than 4.5. The (co)polymer is either an ethylene homopolymer or a copolymer of ethylene and an ?-olefin of 3 to 20 carbon atoms. The melt tension (MT) and the swell ratio (SR) satisfy the relation; log(MT)>12.9?7.15×SR; and the intrinsic viscosity ([?]) and the melt flow rate (MFR) satisfy the relation; [?]>1.85×MFR?0.192 in the case of MFR<1 and the relation; [?]>1.85×MFR?0.213 in the case of MFR?1. Such an ethylene (co)polymer can be usable for various molding applications and especially suitable for pipes.

Abstract: An ethylene (co)polymer of the present invention is a (co)polymer with excellent moldability and mechanical properties and either an ethylene homopolymer or a copolymer of ethylene and an ?-olefin of 4 to 20 carbon atoms. The (co)polymer has methyl branches measured by 13C-NMR less than 0.1 in number per 1,000 carbon atoms and Mw/Mn measured by GPC not lower than 1.8 and lower than 4.5. The (co)polymer is either an ethylene homopolymer or a copolymer of ethylene and an ?-olefin of 3 to 20 carbon atoms. The melt tension (MT) and the swell ratio (SR) satisfy the relation; log(MT)>12.9?7.15×SR; and the intrinsic viscosity ([?]) and the melt flow rate (MFR) satisfy the relation; [?]>1.85×MFR?0.192 in the case of MFR<1 and the relation; [?]>1.85×MFR?0.213 in the case of MFR?1. Such an ethylene (co)polymer can be usable for various molding applications and especially suitable for pipes.

Abstract: An olefin polymerization catalyst having a high polymerization activity at high temperatures and a process for olefin polymerization using the catalyst are disclosed. The olefin polymerization catalyst comprises a transition metal compound which is represented by the following formula (I) and in which the net charge parameter of the central metal is not more than 2.00: wherein M is a transition metal atom of Group 4 to Group 5 of the periodic table, m is an integer of 1 to 5, Q is —N? or —C(R2)?, A is —O—, —S—, —Se— or —N(R5)—, R1 is an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, R2 to R5 are each a hydrogen atom, a hydrocarbon group, an oxygen-containing group or the like, n is a number satisfying a valence of M, and X is a hydrogen atom, a halogen atom, a hydrocarbon group or the like.

Abstract: The present invention provides an olefin polymer having a narrow molecular weight distribution and a specific molecular weight, an olefin polymer having a functional group introduced at the terminal, a tapered polymer containing a segment wherein monomer composition continuously changes in the polymer chain, an olefin polymer having different segments which are bonded to each other, and a process for preparing these polymers. The olefin polymers of the invention are polymers of olefins of 2 to 20 carbon atoms and have a number-average molecular weight of not less than 500 and Mw/Mn of not more than 1.5.

Abstract: The present invention provides an olefin polymer having a narrow molecular weight distribution and a specific molecular weight, an olefin polymer having a functional group introduced at the terminal, a tapered polymer containing a segment wherein monomer composition continuously changes in the polymer chain, an olefin polymer having different segments which are bonded to each other, and a process for preparing these polymers. The olefin polymers of the invention are polymers of olefins of 2 to 20 carbon atoms and have a number-average molecular weight of not less than 500 and Mw/Mn of not more than 1.5.

Abstract: An olefin polymerization catalyst having an excellent polymerization activity and an olefin polymerization process using the catalyst are disclosed. The olefin polymerization catalyst comprises (A) a transition metal compound represented by, for example, the following formula (I) and optionally (B) at least one compound selected from an organometallic compound, an organoaluminum oxy-compound and a compound which reacts with the transition metal compound (A) to from an ion pair; wherein M is a transition metal atom of Group 3 to Group 11 of the periodic table; m is an integer of 1 to 6; A is —O—, —S—, —Se— or —N(R5)—; D is —C(R7)(R8)—, —Si(R9)(R10)— or the like; Z is —R13 and —R14, ═C(R15)R16, ═NR17 or the like; R1 to R17 are each H, a hydrocarbon group or the like; n is a number satisfying a valence of M; and X is halogen, a hydrocarbon group or the like.

Abstract: A thin film magnetic head comprises a slider and a reading/writing element attached to an end surface of the slider, wherein the reading/writing element is disposed at an end surface in the longitudinal direction of the slider when the longitudinal direction and the width direction are determined on the surface which faces a magnetic recording medium, of the slider, and the slider has a linear groove in the surface opposite the surface which faces the magnetic recording medium, at the intermediate portion in the width direction of the slider and along the longitudinal direction.