Abstract: A process for preparing an ultra-high molecular weight polyethylene by the polymerization of ethylene using a catalyst comprising a solid catalyst component and an organometallic compound, characterized in that said solid catalyst component is a product obtained by contacting the following [A] and [B] together:[A] the reaction product of a magnesium dihalide and a titanium compound represented by the general formula Ti(OR).sub.4 wherein R is a hydrocarbon group having 1 to 20 carbon atoms;[B] the reaction product of an aluminum trihalide and a silicon compound represented by the general formula Si(OR').sub.4 wherein R' is a hydrocarbon group having 1 to 20 carbon atoms.

Abstract: Provided is a copolymer having a repeating unit represented by the general formula ##STR1## wherein Ar represents ##STR2## wherein R.sup.1 represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, R.sup.2 represents hydrogen, a hydrocarbon group having 1 to 20 carbon atoms, furyl, pyridyl, chlorophenyl, nitrophenyl or methoxyphenyl, n is 1 or more and an electroactive polymer obtained by doping the above copolymer.

Abstract: A rewritable or repeatedly employable recording medium having a base and a recording layer film provided on said base, characterized in that said recording layer film is formed by a thermotropic cholesteric liquid crystal polyester.

Abstract: A polyethylene resin composition comprising: (A) 50-99.9 parts by weight of an ethylene polymer; and (B) 0.1-50 parts by weight of a modified ethylene-.alpha.-olefin copolymer obtained by fluorinating an ethylene-.alpha.-olefin copolymer having the following properties (i) to (iv), said ethylene-.alpha.-olefin copolymer being prepared by copolymerizing ethylene with an .alpha.-olefin having 3 to 12 carbon atoms in the presence of a catalyst comprising a solid catalyst component and an organoaluminum compound, said catalyst component containing at least magnesium and titanium:______________________________________ (i) Melt index 0.01-100 g/10 min (ii) Density 0.860-0.910 g/cm.sup.3 (iii) Maximum peak tempera- not lower than 100.degree. C. ture (Tm) as measured according to differential scanning calorimetry (DSC) (iv) Boiling n-hexane insolu- not lower than 10 wt.

Abstract: A modified olefinic polymer is obtained by fluorinating an ethylene/.alpha.-olefin copolymer having the following properties (i) to (iv), said ethylene/.alpha.-olefin copolymer being prepared by copolymerizing ethylene and an .alpha.-olefin having 3 to 12 carbon atoms in the presence of a catalyst comprising a solid catalyst component and an organoaluminum compound, said solid catalyst component containing at least magnesium and titanium:(i) Melt index: 0.01-100 g/10 min(ii) Density: 0.860-0.910 g.cm.sup.3(iii) Maximum peak temperature (Tm) as measured according to a differential scanning calorimetry (DSC) should be not lower than 100.degree. C.(iv) Insolubles in boiling n-hexane should be not less than 10% by weight.

Abstract: A polyethylene resin composition comprising (A) 50-99.9 parts by weight of an ethylene polymer and (B) 0.1-50 parts by weight of a modified ethylene polymer obtained by fluorinating an ethylene polymer having a density in the range of larger than 0.910 g/cm.sup.3 and 0.970 g/cm.sup.3 ; said ethylene polymer being prepared by polymerizing ethylene in the presence of a catalyst comprising a catalyst component containing at least one member selected from the group consisting of a titanium compound, vanadium compound and chromium compound, and optionally an organoaluminum compound.

Abstract: A thermoplastic elastomer composition prepared by crosslinking a composition comprising the following components (A), (B) and (C) by using a phenolic curing agent:(A) 30-70 parts by weight of an ethylene/.alpha.-olefin copolymer prepared by copolymerizing ethylene and an .alpha.-olefin having 3 to 12 carbon atoms in the presence of a catalyst comprising a solid component and an organoaluminum compound which solid component contains at least magnesium and titanium, said ethylene/.alpha.-olefin copolymer having the following properties (I) to (IV):______________________________________ (I) Melt index 0.01-100 g/10 min (II) Density 0.860-0.910 g/cm.sup.3 (III) Maximum peak temperature as measured according to a not lower than 100.degree. C. differential scanning calorimetry (DSC) (IV) Insolubles in boiling n-hexane not less than 10 wt.

Abstract: A recording medium having a base and a recording layer provided on said base, said recording layer consisting essentially of a thermotropic cholesteric liquid crystalline glutamate copolymer represented by the following general formula: ##STR1## wherein R.sub.1 is an alkyl, cycloalkyl, aryl or arylalkyl group having not more than 10 carbon atoms, R.sub.2 is an alkyl, cycloalkyl, aryl or arylalkyl group having 6 to 30 carbon atoms, provided R.sub.1 and R.sub.2 are not the same, and m and n are in the relation of 50.ltoreq.m+n.ltoreq.2,000, m/n=80.about.10/20.about.90.

Abstract: A melt spinning apparatus particularly applicable to a multifilament spinning for pitch based carbon fibers. The melt spinning apparatus is provided in which a flow uniforming member is attached to a central part on a spinning side of a spinneret having circularly or concentrically arranged nozzles, the flow uniforming member having a sectional diameter at least 3 mm smaller than the diameter of the innermost row of nozzles and a length not smaller than 2 cm. The apparatus is provided with a cooling means as an outer peripheral portion below a spinning pack having an annular blowing port for blowing a cooling gas toward the spun filaments. A gap is provided between the spinning pack and the cooling means and is sealed with a heat insulator.

Abstract: A process for fabricating a carbon/carbon fiber composite characterized in that one or more kinds of fibers selected from the group consisting of a pitch fiber obtained by spinning a carbonaceous pitch, an infusiblized fiber obtained by subjecting the pitch fiber to an infusiblizing treatment, and a pre-carbonized fiber obtained by subjecting the infusiblized fiber to a pre-carbonizing fiber at 400.degree. to 800.degree. C. in an inert gas atmosphere, are woven, laminated or mix-pulverized together with a pitch-based carbon fiber, and then carbonized under the application of pressure or under pressing.

Abstract: A thermoplastic elastomer composition prepared by partially crosslinking a composition comprising the following components (A), (B) and (C):(A) 30-70 parts by weight of an ethylene/.alpha.-olefin copolymer prepared by copolymerizing ethylene and an .alpha.-olefin having 3 to 12 carbon atoms in the presence of a catalyst comprising a solid component and an organoaluminum compound which solid component contains at least magnesium and titanium, said ethylene/.alpha.-olefin copolymer having the following properties (I) to (IV):______________________________________ (I) Melt index 0.01-100 g/10 min (II) Density 0.860-0.910 g/cm.sup.3 (III) Maximum peak not lower than 100.degree. C. temperature as measured according to a differential scanning calorimetry (DSC) (IV) Insolubles in boiling not less than 10 wt. % n-hexane ______________________________________(B) 70-30 parts by weight of a propylene polymer; and(C) 70-200 parts by weight, based on 100 parts by weight of the components (A) and (B), of an ethylene/.

Abstract: In a process for producing carbon fibers from a carbonaceous pitch, the improvement characterized in that an end portion of infusiblized fiber or carbonized fiber to be first subjected to a carbonizing or graphitizing treatment and that of infusiblized fiber or carbonized fiber to be next subjected to the same treatment are bonded together using a composition comprising (a) at least one member selected from the group consisting of phenolic resins and pitches and (b) graphite powder, and the thus-bonded fibers are fed successively to a carbonizing apparatus or a graphitizing apparatus.

Abstract: A thermoplastic elastomer composition prepared by partially crosslinking a composition comprising the following components (A), (B), (C) and (D):(A) 10-40% by weight of an ethylene/.alpha.-olefin copolymer prepared by copolymerizing ethylene and an .alpha.-olefin having 3 to 12 carbon atoms in the presence of a catalyst comprising a solid component and an organoaluminum compound which solid component contains at least magnesium and titanium, said ethylene/.alpha.-olefin copolymer having the following properties (I) to (IV):(I) Melt index: 0.01-50 g/10 min(II) Density: 0.860-0.910 g/cm.sup.3(III) Maximum peak temperature as measured according to a differential scanning calorimetry (DSC): not lower than 100.degree. C.(IV) Insolubles in boiling n-hexane: not less than 10 wt. %(B) 15-35% by weight of a propylene polymer;(C) 10-40% by weight of an ethylene/.alpha.

Abstract: An ultra-high molecular weight polyethylene powder easily soluble in organic solvents and suitable for use in the preparation of fibers or films having a high strength and a high elastic modulus, said polyethylene powder having an intrinsic viscosity in the range of 5 to 30 dl/g in decalin at 135.degree. C. and being obtained by at least two-step polymerization reactions which are:a first step of polymerizing ethylene in the absence of hydrogen or at a reduced hydrogen concentration, using a catalyst containing a solid catalyst component and an organometallic compound, said solid catalyst component containing at least magnesium and titanium and/or vanadium, to produce 50-99.5 parts by weight, based on 100 parts by weight of a final polyethylene product, of polyethylene having an intrinsic viscosity of 12 to 32 dl/g in decalin at 135.degree. C.; anda second step of polymerizing ethylene at a higher hydrogen concentration that in said first step to produce 50-0.5 parts by weight of polyethylene.

Abstract: A cholesteric liquid crystal polyester consisting essentially of the following structural units (A), (B), (C) and (D): ##STR1##

Abstract: A .gamma.-benzyl glutamate-.gamma.-alkyl glutamate copolymer having the general formula (I) ##STR1## wherein; R is C.sub.10-30 alkyl group, m and n are 50.ltoreq.m+n.ltoreq.2,000 and m/n=80-10/20-90, and benzyl ester unit and alkyl ester unit are either both L-forms or both D-forms.

Abstract: A process for producing a cholesteric liquid crystal polyester film or sheet possessing an ordered planar texture (monodomain structure), which process comprises providing a cholesteric liquid crystal polyester in which 1 to 10 mol % of constituent monomer units are optically active, allowing the cholesteric liquid crystal polyester to be formed in the temperature range of 150.degree. to 350.degree. into a film or sheet having a thickness not larger than 100 .mu.m, and then cooling the film or sheet rapidly.

Abstract: A cholesteric liquid crystal polyester consisting essentially of structural units represented by the following formulae (A), (B) and (C): ##STR1## which is optically active; and ##STR2## wherein X is hydrogen, halogen, or alkyl having not more than four carbon atoms.

Abstract: A crosslinked resin composition obtained by crosslinking a composition comprising (A) 95-10 wt. % of a propylene polymer and (B) 5-90 wt. % of an ethylene/.alpha.-olefin copolymer having the following properties (I) to (iv) and prepared by copolymerizing ethylene with an .alpha.-olefin having 3 to 12 carbon atoms in the presence of a catalyst, said catalyst comprising a solid component and an organoaluminum compound, said solid component containing at least magnesium and titanium:______________________________________ (i) Melt index 0.01-100 g/10 min (ii) Density 0.860-0.910 g/cm.sup.3 (iii) Maximum peak temperature not lower than 100.degree. C. measured according to a differential scanning calorimetry (DSC) (iv) Insolubles in boiling not less than 10 wt.

Abstract: A melt-spinning nozzle in which is disposed an elongated molded piece so as to form a space serving as a melt flow path between the elongated molded piece and the inner wall of the nozzle.