Abstract:
Nuclear fuels, such as uranium trioxide, are prepared by thermal decomposition of a nitrate in a fluidized bed reactor. The fluidized bed reactor for preparing uranium trioxide from uranyl nitrate by thermal decomposition has (a) a rectangularly shaped bed which satisfies the critical safety shape of .sup.235 U, (b) plural holes to supply an aqueous solution of uranyl nitrate into the reactor, (c) at least two reaction rooms divided by barriages, the bottoms of the barriers being capable of being lifted to control their distance from the floor and a mechanism by which uranium trioxide powder is taken out mainly by being overflowed from the top of the barriers through the reaction rooms, (d) heating means inside and outside of the fluidized-bed, and (e) a head structure which is upwardly V-shaped. Continuous operation can be attained with ease, and uranium trioxide can be made efficiently.
Abstract:
An ethylene polymer having small values of Mw/Mn and Mz/Mw, a small proportion of long-chain branches, a high melt tension and a high swell ratio, and a process for preparing the ethylene polymer are disclosed. A solid titanium catalyst component obtained by initially bringing a solid titanium composite which is obtained by the contact of a solid magnesium aluminum composite containing magnesium, halogen, aluminum, and an alkoxy group of 6 or more carbon atoms and/or alcohol of 6 or more carbon atoms with a tetravalent titanium compound into contact with an organometallic compound, and then bringing the resulting product into contact with oxygen is further disclosed. An ethylene polymerization catalyst comprising the above catalyst component and an organometallic compound catalyst component is furthermore disclosed. Therefore, the ethylene polymer is excellent in moldability, and a molded article obtained therefrom is excellent in rigidity and impact resistance and free from poor appearance.
Abstract:
A process for preparing a propylene polymer composition comprising conducting multistage polymerization including a step (a) for preparing a propylene (co)polymer (a) and a step (b) for preparing an ethylene copolymer (b) in the presence of (A) a transition metal compound and (B) a compound activating the transition metal compound (A), in which the steps (a) and (b) may be carried out in any order, and the resulting propylene polymer composition contains the propylene (co)polymer (a) in an amount of 20 to 90% by weight and the ethylene copolymer (b) in an amount of 10 to 80% by weight and has MFR, as measured at 230.degree. C. under a load of 2.16 kg, of 0.01 to 500 g/10 min; and a propylene polymer composition prepared by this process. The process according to the invention can prepare a propylene polymer composition having excellent rigidity, heat resistance and impact resistance.
Abstract:
A multi-layer pipe has an innermost layer formed of a butene polymer composition. At least one other layer is formed of a polyolefin resin composition comprising (A) 95-5 parts by weight of a polyolefin resin, (B) 5-95 parts by weight of a filler, and (C) 0.1-10 parts by weight per 100 parts by weight of components (A) and (B) combined of a modified polyolefin resin. This multi-layer pipe undergoes minimal elongation by heat so that it is free from troubles by thermal deformation even when high temperature fluid is passed therethrough, has high rigidity, and is thus suitable as plumbing for cold and hot water.
Abstract:
A process for producing a polyethylene terephthalate in which the amount of the oligomers, such as cyclic trimer etc., is lower and which causes metal mold staining to occur difficultly. The process comprises an esterification stage in which dicarboxylicacids including mainly terephthalic acid or ester-forming derivatives of such acids are esterified with glycols including mainly ethylene glycol or with ester-forming derivatives of such glycols; a liquid phase polycondensation stage in which the esterified product obtained in the esterification stage is subjected to a polycondensation in a liquid phase containing a polycondensation catalyst and having a content of an alkaline solubilizing agent of 0.4 mole or less per mole of the polycondensation catalyst with heating; a solid phase polycondensation stage in which the polycondensation product obtained in the liquid phase polycondensation stage is heated at a temperature below the melting point of the product in an inert atmosphere; and an aqua-treatment stage in which the polycondensation catalyst is deactivated by contacting the polycondensation product obtained in the solid phase polycondensation stage with water. The polyethylene terephthalate obtained by this process is suitable as the material for containers to be charged with drinks.
Abstract:
A solid titanium catalyst component comprising (a) magnesium, (b) titanium, (c) a halogen, (d) a polyether, (e) a hydrocarbon and (f) an electron donor other than the polyether (d) as essential components is provided. Also a process for preparing a solid titanium catalyst component for olefin polymerization, comprising the steps of contacting a halogenated magnesium compound with a compound selected from the group consisting of an alcohol, an ether and an ester in a hydrocarbon solvent to obtain a magnesium compound solution, contacting the magnesium compound solution with a polyether and contacting the resultant solution with a liquid titanium compound is provided. Further, a catalyst for olefin polymerization comprising the above-mentioned solid titanium catalyst component, an organoaluminum compound catalyst component and an electron donor, and a process for polymerizing an olefin using the catalyst for olefin polymerization are also disclosed. By the use of the catalyst for olefin polymerization, an olefin (co)polymer having uniform particle size, less dust quantity, high bulk density and high stereoregularity can be obtained with excellent polymerization activity.
Abstract:
A process for preparing a propylene polymer composition having excellent rigidity, heat resistance and impact resistance comprising conducting multistage polymerization including a step (a) for preparing a propylene (co)polymer (A), a step (b) for preparing a propylene-olefin copolymer (B) and a step (c) for preparing an ethylene-olefin copolymer (C) in the presence of (I) a transition metal compound and (II) a compound activating the transition metal compound (I), in which the steps (a), (b) and (c) are carried out in any order, each of the second and subsequent stage polymerizations is carried out in the presence of a polymer or polymers obtained by the preceding stage or stages, respectively, and the resulting propylene polymer composition contains the propylene (co)polymer (A) in an amount of 20 to 90% by weight, the propylene-olefin copolymer (B) in an amount of 5 to 75% by weight and the ethylene-olefin copolymer (C) in an amount of 5 to 75% by weight, and has MFR, as measured at 230.degree. C. under a load of 2.16 kg, of 0.01 to 500 g/10 min.
Abstract:
Olefin thermoplastic elastomers which comprise a partially crosslinked thermoplastic elastomer comprising a crystalline polyolefin resin (A), a block copolymer (B) which is composed of a polymer block of styrene or its derivative and a specific isoprene polymer block, and an olefin rubber (C), and thermoplastic elastomer laminates, having a substrate formed from a specific olefin thermoplastic elastomer or a crystalline polyolefin resin and a skin layer formed from the above-mentioned olefin thermoplastic elastomer, which are excellent in mechanical strength, heat resistance, heat aging resistance, weathering resistance and scratch resistance have been provided by the present invention.
Abstract:
This invention relates to a process for polymerizing olefins using a catalyst composed of a transition metal catalyst component, an aluminoxane component and an organoaluminum component. In the process of this invention, the catalyst exhibits excellent polymerization activity with the use of a small amount of the aluminoxane xane. The polymerization process gives olefin polymers having a narrow molecular weight distribution and by the copolymerization of two or more olefins, gives olefin copolymers having a narrow molecular weight distribution and a narrow composition distribution.
Abstract:
A branched polyene compound represented by the formula ##STR1## wherein f is an integer of 1-5; R.sup.1 and R.sup.2 represent hydrogen atoms or alkyl groups of 1-5 carbons; R.sup.3 represents a hydrogen atom or an alkyl group of 1-5 carbons or an alkenyl group represented by the formula ##STR2## wherein n is an integer of 1-5; R.sup.4, R.sup.5 and R.sup.6 represent hydrogen atoms or alkyl groups of 1-5 carbons; all of R.sup.1, R.sup.2, R.sup.3 are not simultaneously hydrogen atoms; and all of R.sup.4, R.sup.5 and R.sup.6 are not simultaneously hydrogen atoms.