Abstract: An injection molding apparatus for injection molding a multi-layered article is disclosed. The apparatus comprises; (a) a mold having a cavity block provided with a cavity and a hot runner block, (b) at least a first injection cylinder and a second injection cylinder, (c) a first resin-flow-passage for connecting an inside of the first injection cylinder and the cavity, and (d) a second resin-flow-passage for connecting an inside of the second injection cylinder and the cavity. The injection molding apparatus has a structure in which those portions of the first and second resin-flow-passages which are located within the mold are provided in the hot runner block, and the first resin-flow-passage and the second resin-flow-passage meet with each other in a junction portion upstream to a gate portion opened to the cavity.

Abstract: An ether compound having a specific episulfide structure and a cured resin prepared by using this ether compound.

Abstract: The present invention presents: (1) a starting method that is capable of quickly switching to the reforming process after warming up a catalyst; (2) a fuel supplying apparatus that is capable of maintaining a stable supply of a mixed water-methanol solution while preventing water from freezing in a cold climate, and is also capable of immediately supplying a mixed water-methanol gas that has a composition which is outside of the high-rate reaction region during the starting/stopping operation of the reformer when the control tends to be unstable; (3) a method to quickly cool down a catalyst layer without causing thermal runaway when stopping the operation of the methanol reforming apparatus; and (4) a method to quickly cool down the catalyst layer while preventing thermal runaway from occurring and removing residual fuel when stopping the operation of the methanol reforming apparatus.

Abstract: A cleaning agent for use in producing semiconductor devices. The cleaning agent is an aqueous solution containing (A) a fluorine-containing compound, (B) a salt of boric acid, (C) a water-soluble organic solvent, and optionally, (D) a specific quaternary ammonium salt or (D′) a specific ammonium salt of an organic carboxylic acid or a specific amine salt of an organic carboxylic acid. The polymeric deposit inside and around the via holes and on the side wall of the conductive line pattern formed during the dry etching process can be effectively removed by using the cleaning agent without affecting the dimensions of the via holes and the conductive line pattern.

Abstract: An anti-ferroelectric liquid crystal composition containing a phenyl triester compound of the formula (1), wherein R1 is a linear alkyl group having 6 to 12 carbon atoms, m is an integer of 0 to 3, n is an integer of 1 to 3, and X1 is a hydrogen atom or a fluorine atom, and an anti-ferroelectric liquid crystal compound of the formula (2),  wherein R2 is a linear alkyl group having 6 to 12 carbon atoms, X2 is a hydrogen atom or a fluorine atom, A is —CH3 or —CF3, r is 0 or 1 and C* is an asymmetric carbon, provided that when A is —CH3, r is 0 and p is an integer of 4 to 10, that when A is —CF3 and when r is 0, p is an integer of 6 to 8, and further than when A is —CF3 and when r is 1, q is an integer of 5 to 8 and p is 2 or 4.

Abstract: A polyoxymethylene resin composition comprising: (A) 100 parts by weight of a polyoxymethylene copolymer; (B) 0.01 to 7 parts by weight of an amine-substituted triazine compound; and (C) 0.01 to 5 parts by weight of (C-1) polyethylene glycol having an average molecular weight of 10,000 or more and/or (C-2) modified polyolefin wax having an acidic group with an acid value of 0.5 to 60 mg-KOH/g. According to the present invention, there can be provided a polyoxymethylene resin molded product which has low shrink anisotropy, excellent thermal stability and dimensional stability.

Abstract: A novel ferrielectric liquid crystal compound of the formula (1), wherein R is a linear alkyl group having 6 to 12 carbon atoms, X is a hydrogen atom or a fluorine atom, m is an integer of 1 to 3, n is an integer of 1 to 3, and C* is an asymmetric carbon atom. The ferrielectric liquid crystal compound of the invention characteristically has a ferrielectric phase in a broad temperature range and shows a high speed optical response in spite of a small spontaneous polarization.

Abstract: A composition for a resin comprising (a) a sulfur-containing compound having in one molecule one or more episulfide groups and/or epoxy groups and (b) a compound having in one molecule one or more isocyanate groups and/or thioisocyanate groups. The composition is useful as an optical material such for a plastic lens for glasses, since the composition exhibits an excellent balance between refractivity index and Abbe number and has a high impact resistance.

Abstract: A hydrogenation catalyst for the production of hydrogen peroxide by the hydrogenation of anthraquinones in accordance with a hydrogen peroxide production process utilizing an anthraquinone method. The catalyst includes palladium supported on a carrier. The carrier comprises spherical silica particles, wherein at least 90 wt % of the silica particles have particle diameters of 10 to 100 .mu.m. The silica particles have an average particle diameter of 30 to 60 .mu.m and a pore volume of 0.4 to 1.0 ml/g. The catalyst has desirable activity, strength, service life and selectivity.

Abstract: Provided are an anti-ferroelectric liquid crystal composition consisting essentially of (a) a swallow-tailed compound of the formula (1), (b) an anti-ferroelectric liquid crystal compound of the formula (2), and (c) a phenyl ester compound of the formula (3), and a liquid crystal display device using the composition, ##STR1## The above anti-ferroelectric liquid crystal composition has an anti-ferroelectric phase in a broad temperature range, has a high response time I in the transition from an anti-ferroelectric state to a ferroelectric state and a proper response time II in the transition from a ferroelectric state to an anti-ferroelectric state, and can therefore provide an anti-ferroelectric liquid crystal display device having high display quality.

Abstract: A reflective type optical signal distributor comprising, in a housing (2), a plurality of optical input/output units (3) functioning as input and output terminals for an optical signal, an optical circuit assembly (6) for reflecting and separating the optical signal, and a plurality of guide optical fibers (8) for connecting the plurality of optical signals entering any one of the plurality of optical input/output units (3) and the optical circuit assembly (6), whereby an optical input/output units (3) is substantially equally distributed to all other ones of the plurality of optical input and output units (3), the optical circuit assembly (6) comprising an optical circuit in which a plurality of independent branched optical waveguides (22) merge into a single main optical waveguide (21), a reflective surface (4) formed at an end of the main waveguide (21), and the plurality of guide optical fibers (8) being connected to the corresponding plurality of independent branched optical waveguides (22).

Abstract: A process for preparing a cyclic ester by reacting an .alpha.-hydroxycarboxylic acid or an .alpha.-hydroxycarboxyliclic acid ester with an orthoester. A process for purifying a cyclic ester by containing water and acid as impurities by adding an orthoester to a cyclic ester obtained by reaction of a reaction mixture including an .alpha.-hydrocarboxylic acid or an .alpha.-hydroxycarboxyliclic acid ester. According to the present invention, a high-purity cyclic ester containing small amounts of impurities such as water and an acid component can be provided.

Abstract: There is disclosed a process for producing 3-methyltetrahydrofuran substantially free from any of an alcohol and water which comprises adding an organic solvent capable of forming an azeotropic mixture with an alcohol with an alkyl group having 1 to 3 carbon atoms to a mixed liquid containing 3-methyltetrahydrofuran, the alcohol and/or water as the principal components and, as the case may be, another substance, and distilling the resultant mixture of the mixed liquid and said organic solvent. According to the above process, it is made possible to efficiently separate a mixture of 3-methyltetrahydrofuran and an alcohol and/or water which mixture is difficult to separate with conventional distillation process alone, thereby efficiently producing the objective 3-methyltetrahydrofuran substantially free from any of an alcohol and water.

Abstract: An optical fiber array, wherein a plurality of optical fibers are inserted between a pair of substrates consisting of a first substrate, wherein a parallel groove is formed at one end thereof for accommodating the ends of portions of a plurality of optical fibers where no covering portions are formed, an approximately rectangular groove is formed at the other end thereof for accommodating the portions of said optical fibers where covering portions are formed, and a tapered groove is formed which connects from said parallel groove towards the approximately rectangular groove whilst rectangular groove is formed at said other end thereof for accommodating the portions of said optical fibers where covering portions are formed.

Abstract: There are disclosed a method for replacing a dispersion medium wherein an original slurry comprising solid particles and an original dispersion medium is introduced in a dispersion medium replacement column at the top thereof, a replacing dispersion medium is introduced in the column at the bottom thereof to replace the original dispersion medium with the replacing dispersion medium, the resultant replaced slurry comprising the solid particles and the replacing dispersion medium is taken out from the column at the bottom thereof, and the original dispersion medium is taken out from the column at the top thereof, which method comprises dividing the fluid in the intermediate portion into a plurality of parallel streams, stirring the slurry in the bottom of the column to uniformize the slurry, and controlling the feed rates of the replacing dispersion medium and the replaced slurry to maintain the slurry in the bottom portion of the column at a concentration higher than that of the slurry in the intermediate por

Abstract: There is disclosed a process for producing highly pure terephthalic acid by converting a slurry of terephthalic acid crystals in acetic acid solvent which crystals are obtained by liquid-phase oxidation of p-alkylbenzene, into a slurry thereof in water solvent by mother liquor replacement and then subjecting the latter slurry to a catalytic hydrogenation treatment which process comprises the steps of introducing the slurry of terephthalic acid crystals in acetic acid into a mother liquor replacement column at the top portion; forming an accumulation layer of the terephthalic acid crystals at the bottom portion by the sedimentation of the crystals; feeding replacing water sufficient for the formation of upward rising stream of water to the inside of the column at the bottom portion; and withdrawing the accumulation layer of the crystals from the bottom portion of the column.

Abstract: Stripping and cleaning agent for removing dry-etching photoresist residues, and a method for forming an aluminum based line pattern using the stripping and cleaning agent. The stripping and cleaning agent contains (a) from 5 to 50% by weight of an organocarboxlic ammonium salt or an amine carboxylate, represented by the formula [R.sup.1 ]m[COONH.sub.p (R.sup.2)q]n, where R.sup.1 is hydrogen, or an alkyl or aryl group having from 1 to 18 carbon atoms; R.sup.2 is hydrogen, or an alkyl group having from 1 to 4 carbon atoms; m and n independently are integers of from 1 to 4, p is integer of from 1 to 4, q is integer of from 1 to 3, and p+q=4 and (b) from 0.5 to 15% by weight of a fluorine compound. The inventive method is advantageously applied to treating a dry-etched semiconductor substrate with the stripping and cleaning agent. The semiconductor substrate comprises a semiconductor wafer having thereon a conductive layer containing aluminum.

Abstract: A process for producing 3-methyltetrahydrofuran, wherein in a first step, prussic acid is reacted with methyl methacrylate to produce methyl 3-cyanoisobutyrate. The methyl 3-cyanoisobutyrate is then reacted with water and sulfuric acid to produce a resultant product which is reacted with a C.sub.1 -C.sub.8 aliphatic alcohol to produce a methylsuccinic acid ester. The methylsuccinic acid ester is catalytically hydrogenated to prepare the 3-methyltetrahydrofuran. Alternatively, the methyl 3-cyanoisobutyrate is hydrated to produce methyl 3-carbamoylisobutyrate, which is then reacted with a formic acid ester to form a methylsuccinic acid ester and formamide and the resultant methylsuccinic acid ester is catalytically hydrogenated. The 3-methyltetrahydrofuran is produced in high selectivity and in a commercially advantageous manner from inexpensive reactants. The 3-methyltetrahydrofuran is useful as a commoner for producing polyether glycol, which is utilized as starting raw material for preparing spandex fiber.

Abstract: A process for purification of hydrogen peroxide is provided which comprises contacting an aqueous hydrogen peroxide solution with a chelate resin. According to the process, it is possible to remove impurities in the aqueous hydrogen peroxide solution in high efficiency, and particularly, it is possible to remove iron, aluminum, etc., which are difficult to remove singly by ion exchange resins, up to extremely low concentrations. Highly pure hydrogen peroxide solutions obtained by this invention can suitably used for washing of silicon wafers.

Abstract: A method for producing a copolyamide, which comprises (1) heating either one dicarboxylic acid selected from the group consisting of adipic acid and a mixture containing 40 mol % or more of adipic acid to a temperature higher than the melting point of adipic acid but lower than a temperature lower by 30.degree. C. than the melting point of the resulting copolyamide, (2) dropping a diamine comprising paraxylylene diamine and metaxylylene diamine into the heated dicarboxylic acid before a conversion of the dicarboxylic acid reaches 90 mol %, (3) stopping dropping of the diamine before the conversion of the dicarboxylic acid reaches 90 mol %, and dropping metaxylylene diamine or a diamine mixture of metaxylylene diamine and paraxylylene diamine in place of the diamine until a molar ratio of the total of the diamines to the total of the dicarboxylic acids becomes 0.97 to 1.03, and (4) heating a reaction system to a temperature higher than a temperature lower by 30.degree. C.