Abstract: Disclosed is a solid titanium catalyst component which is obtained by a process comprising the steps of bringing (a) a liquid magnesium compound into contact with (b) a liquid titanium compound in the presence of (c) an organosilicon compound having no active hydrogen in an amount of 0.25 to 0.35 mol based on 1 mol of the magnesium compound (a), elevating the temperature of the resulting contact product to a temperature of 105 to 115° C. and maintaining the contact product at this temperature. The contact product may be further brought into contact with not more than 0.5 mol of the organosilicon compound having no active hydrogen (c). Also disclosed are an ethylene polymerization catalyst formed from the solid titanium catalyst component and an organometallic compound and an ethylene polymerization process using the catalyst. By the use of the solid titanium catalyst component, ethylene can be polymerized with high activities and an ethylene polymer having excellent particle properties can be prepared.

Abstract: Disclosed is a solid titanium catalyst component which is obtained by a process comprising the steps of bringing (a) a liquid magnesium compound into contact with (b) a liquid titanium compound in the presence of (c) an organosilicon compound having no active hydrogen in an amount of 0.25 to 0.35 mol based on 1 mol of the magnesium compound (a), elevating the temperature of the resulting contact product to a temperature of 105 to 115° C. and maintaining the contact product at this temperature. The contact product may be further brought into contact with not more than 0.5 mol of the organosilicon compound having no active hydrogen (c). Also disclosed are an ethylene polymerization catalyst formed from the solid titanium catalyst component and an organometallic compound and an ethylene polymerization process using the catalyst. By the use of the solid titanium catalyst component, ethylene can be polymerized with high activities and an ethylene polymer having excellent particle properties can be prepared.

Abstract: A multiple disc changer apparatus has an elastic support mechanism for supporting the recording/reproducing unit on a main body of the apparatus and includes a locking mechanism for controlling the elastic support of the elastic support mechanism when a disc is loaded on the recording/reproducing unit by a chucking mechanism.

Abstract: A recording and/or reproducing apparatus for discs includes a housing unit housing a large number of discs, a recording and/or reproducing unit on which one of the discs held within a large number of disc holders provided in the housing unit is selectively loaded, and a transporting mechanism for transporting the disc held within a selected one of the holders of the housing unit to the recording and/or reproducing unit. The disc transporting mechanism detects whether or not the disc is held in the holder. A detection switch is activated when no disc is present in the holder. The housing unit includes a plurality of the holders positioned radially such that the disc surfaces are held upright. The selected disc held in the holder of the disc transporting mechanism is transported by the transporting mechanism in the upright position to the disc reproducing unit and loaded therein.

Abstract: A recording and/or reproducing apparatus for discs including a housing unit housing a large number of discs, a recording and/or reproducing unit on which one of the discs held within a large number of disc holders provided in the housing unit is selectively loaded and a transporting mechanism for transporting the disc held within a pre-set one of the holders of the housing unit to the recording and/or reproducing unit. In the course of transporting the disc, the disc transporting mechanism detects whether or not the disc is held in the holder. The housing unit include a plurality of the holders for radially holding the discs with the disc surfaces being erected upright. The disc held in the holder is transported by the transporting mechanism in the upstanding position as far as the disc reproducing unit and there loaded.

Abstract: This invention is to provide a novel process for the isomerization of a cycloolefin having an endo form to a cycloolefin having an exo form. The resulting isomer mixture has a novel composition, and a random copolymer produced from the above compositionally novel isomer mixture and ethylene has an excellent heat resistance and mechanical strength.

Abstract: In accordance with the present invention, there are provided cycloolefin random copolymers composed of ethylene and cycloolefin and containing substantially no polyethylene, and processes for preparing the same. Optical disc substrates prepared from the above-mentioned copolymers are excellent in transparency and also capable of minimizing the occurence of errors in reading of the discs due to quality of the substrates used therefor.

Abstract: A random copolymer of an .alpha.-olefin having 4 to 12 carbon atoms with an aromatic vinyl monomer containing 50 to 98% by mol of .alpha.-olefin and having a softening point of 40.degree. to 150.degree. C. is useful as a hot-melt adhesive and is excellent in adhesiveness, workability, environmental aging resistances such as thermal aging resistance. The copolymer is combined with 70 to 10% by weight of a tackifier for the whole so that it can be used as a hot-melt adhesive or a heat sealant.

Abstract: A process for the production of a cycloolefin-based random copolymer, which comprises:(A) copolymerizing (a) ethylene and (b) at least one cycloolefin,(B) in the presence of a catalyst comprising a vanadium compound soluble in a mixed solvent described below and an organoaluminum compound.(C) in a mixed solvent comprising (a) a hydrocarbon-based solvent having a solubility parameter (.delta. value) of not less than 7.7 (cal/cm.sup.3).sup.1/2 and (b) a hydrocarbon-based solvent having a solubility parameter (.delta. value) of not more than 7.5 (cal/cm.sup.3).sup.1/2, the mixed solvent having a volume ratio (a)/(b) of 90/10 to 50/50. The said process permits the production of a copolymer in a higher concentration when copolymers having an identical molecular weight to that of conventional copolymers are produced, and permits the production of a copolymer having a higher molecular weight when copolymers are produced in an identical concentration to that of conventional copolymers.

Abstract: This invention is to provide a novel process for the isomerization of a cycloolefin having an endo form to a cycloolefin having an exo form. The resulting isomer mixture has a novel composition, and a random copolymer produced from the above compositionally novel isomer mixture and ethylene has an excellent heat resistance and mechanical strength.

Abstract: There is provided a liquid oxidatively modified ethylenic random copolymer, which is an oxidatively modified product of a liquid ethylenic random coplymer comprising 20 to 80 mol % of ethylene and 80 to 20 mol % of .alpha.-olefin, and has (i) a number average molecular weight (Mn) in the range of from 200 to 10,000, (ii) a molecular weight distribution (Mw/Mn) given as weight average molecular weight (Mw) divided by number average molecular weight (Mn) in the range of up to 4, and (iii) an oxygen content of from 0.1 to 20% by weight, an acid value of from 0.1 to 50, and a saponification value of from 0.1 to 100. It is prepared by contacting a corresponding ethylenic random copolymer with oxygen-containing gas at 100.degree.-250.degree. C.

Abstract: According to the present invention, a zinc-containing solid catalyst prepared by contacting zinc oxide with an organic dicarboxylic acid in the presence of or in the absence of an organic solvent under a mechanical pulverization treatment is provided. The catalyst is in a good pulverized state and exhibits a high catalytic activity for polymerization of carbon dioxide with an epoxide to obtain a polyalkylene carbonate.

Abstract: A reflection-preventive layer composed of a specific polyfluoro(meth)acrylate is formed on one or both of the surfaces of a transparent film of a cellulose derivative. In this reflection-preventive pellicle film, the minimum light transmission in wavelengths of 350 to 450 nm is improved and the average light transmission is improved, and the adhesion of the reflection-preventive layer to the cellulose derivative layer is excellent.

Abstract: An external agent for application to the skin, such as a cosmetic, an ointment or a hair remover, comprises a liquid low-molecular-weight ethylenic copolymer having an ethylene content of 30 to 70 mole %, a number average molecular weight of 150 to 5,000, a Q value, as defined in the specification, of not more than 4, a standard deviation, as defined in the specification, of not more than 3, and a B value, as defined in the specification, of 1.0 to 1.5.

Abstract: There is provided a liquid oxidatively modified ethylenic random copolymer, which is an oxidatively modified product of a liquid ethylenic random copolymer comprising 20 to 80 mol % of ethylene and 80 to 20 mol % of .alpha.-olefin, and has (i) a number average molecular weight (Mn) in the range of from 200 to 10,000, (ii) a molecular weight distribution (Mw/Mn) given as weight average molecular weight (Mw) divided by number average molecular weight (Mn) in the range of up to 4, and (iii) an oxygen content of from 0.1 to 20% by weight, an acid value of from 0.1 to 50, and a saponification value of from 0.1 to 100. It is prepared by contacting a corresponding ethylenic random copolymer with oxygen-containing gas at 100.degree.-250.degree. C.

Abstract: A liquid polymer composition contains:(A) a liquid low molecular weight ethylene-.alpha.-olefin copolymer comprising 30 to 70 mol % of ethylene component units and 30 to 70 mol % of .alpha.-olefin component units, having a number average molecular weight (Mn) in the range of 150 to 10000, with a Q-value (weight average molecular weight/number average molecular weight) of 3 or less, and(B) A high molecular weight polymer which is in an amount of 0.05 to 100 parts by weight based on 100 parts by weight of the liquid low molecular weight polymer (A), having a number average molecular weight (Mn) of 20000 or higher, witha Q-value of 6 or less, and is soluble in the liquid low molecular weight polymer (A), which liquid polymer composition has an excellent viscosity characteristic, lubrication characteristic, and oxidation stability, without denaturation by moisture adsorption, and therefore, is suitable for use as an actuation oil.