Abstract: The object of the present invention is to provide an oxygen isotope concentration method capable of concentrating the stable oxygen isotopes of 17O and 18O which can be carried out using a simple device configuration. The present invention relates to a method for concentrating an oxygen isotope in separated oxygen by irradiating ozone with light, selectively dissociating an isotopomer of ozone containing an oxygen isotope in its molecule into oxygen, followed by dissociating the ozone and separating the formed oxygen from the non-dissociated ozone.

Abstract: An apparatus comprising first to third columns, wherein the outlet of a first column reboiler and the inlet of a second column condenser are connected by a first introduction conduit, and the outlet of a second distillation column reboiler and the inlet of a third column condenser are connected by a second introduction conduit, and additionally the outlet of the second column condenser and the inlet of the first column reboiler are connected by a first return conduit, and the outlet of the third column condenser and the inlet of the second column reboiler are connected by a second return conduit.

Abstract: An apparatus comprising first to third columns, wherein the outlet of a first column reboiler and the inlet of a second column condenser are connected by a first introduction conduit, and the outlet of a second distillation column reboiler and the inlet of a third column condenser are connected by a second introduction conduit, and additionally the outlet of the second column condenser and the inlet of the first column reboiler are connected by a first return conduit, and the outlet of the third column condenser and the inlet of the second column reboiler are connected by a second return conduit.

Abstract: The gas separation and purification process can recover efficiently a valuable gas such as krypton and xenon to be used as an atmospheric gas in a semiconductor manufacturing equipment etc. by means of PSA process. In the process for separating a valuable gas in the form of purified product from a mixed gas, used as a raw gas, containing the valuable gas by means of pressure swing adsorption process, the valuable gas is separated and purified by using as the pressure swing adsorption process a combination of equilibrium pressure swing adsorption process for separating gas components based on the difference in equilibrium adsorption and rate-dependent pressure swing adsorption process for separating the gas components based on the difference in adsorption rates.

Abstract: By using a dephlegmator which conducts distillation concurrently with heat exchange within at least one distillation column, or a portion of one distillation column, of a distillation cascade, the quantity of liquid holdup within the distillation apparatus is reduced and the start-up time is shortened. Consequently, the operational costs associated with startup are reduced, and productivity is improved markedly.

Abstract: There is provided a method and an apparatus for collecting a rare gas, which are capable of effectively collecting the rare gas contained in an exhaust gas exhausted from a rare gas using apparatus such as a plasma apparatus or the like, and moreover capable of securely supplying the rare gas having a predetermined purity to the rare gas using apparatus, and the method for collecting rare gas which comprises collecting a rare gas contained in an exhaust gas exhausted from a rare gas using apparatus operated under decompression, the method comprises the step of collecting the rare gas by separating the rare gas and impurities contained in the exhaust gas via at least two gas separating steps.

Abstract: In an vapor-liquid contactor 4a for flowing down a liquid along the surface of a packing and contacting said liquid with the vapor while ascending the vapor, the improvement being characterized in that said packing is a non-promoting-fluid-dispersion type structured packing A1, A2 in which various types of thin sheets or tubes for determining the flow direction of the above liquid or vapor is laminated and arranged in the perpendicular direction, and said contactor includes at least one fluid distribution unit E1, E2 formed of a rough distribution part C1, C2 to distribute the liquid roughly and a minute distribution part B1, B2 to distribute the liquid minutely and equally.

Abstract: In an vapor-liquid contactor 4a for flowing down a liquid along the surface of a packing and contacting said liquid with the vapor while ascending the vapor, the improvement being characterized in that said packing is a non-promoting-fluid-dispersion type structured packing A1, A2 in which various types of thin sheets or tubes for determining the flow direction of the above liquid or vapor is laminated and arranged in the perpendicular direction, and said contactor includes at least one fluid distribution unit E1, E2 formed of a rough distribution part C1, C2 to distribute the liquid roughly and a minute distribution part B1, B2 to distribute the liquid minutely and equally.

Abstract: The gas separation and purification process can recover efficiently a valuable gas such as krypton and xenon to be used as an atmospheric gas in a semiconductor manufacturing equipment etc. by means of PSA process. In the process for separating a valuable gas in the form of purified product from a mixed gas, used as a raw gas, containing the valuable gas by means of pressure swing adsorption process, the valuable gas is separated and purified by using as the pressure swing adsorption process a combination of equilibrium pressure swing adsorption process for separating gas components based on the difference in equilibrium adsorption and rate-dependent pressure swing adsorption process for separating the gas components based on the difference in adsorption rates.

Abstract: In an vapor-liquid contactor 4a for flowing down a liquid along the surface of a packing and contacting said liquid with the vapor while ascending the vapor, the improvement being characterized in that said packing is a non-promoting-fluid-dispersion type structured packing A1, A2 in which various types of thin sheets or tubes for determining the flow direction of the above liquid or vapor is laminated and arranged in the perpendicular direction, and said contactor includes at least one fluid distribution unit E1, E2 formed of a rough distribution part C1, C2 to distribute the liquid roughly and a minute distribution part B1, B2 to distribute the liquid minutely and equally.

Abstract: A method and apparatus for enrichment of heavy oxygen isotopes is provided wherein an oxygen starting material which contains heavy oxygen isotopes is enriched in at least one of oxygen molecule 16O17O, 16O18O, 17O17O, 17O18O and 18O18O, by means of cryogenic distillation of the oxygen starting material containing heavy oxygen isotopes. In addition, a method and apparatus are provided for further increasing the concentration of at least one of the heavy isotope oxygen molecules by means of conducting isotope scrambling on the above-mentioned plurality of oxygen molecules enriched by means of the above mentioned cryogenic distillation.

Abstract: There is provided a method and an apparatus for collecting a rare gas, which are capable of effectively collecting the rare gas contained in an exhaust gas exhausted from a rare gas using apparatus such as a plasma apparatus or the like, and moreover capable of securely supplying the rare gas having a predetermined purity to the rare gas using apparatus, and the method for collecting rare gas which comprises collecting a rare gas contained in an exhaust gas exhausted from a rare gas using apparatus operated under decompression, the method comprises the step of collecting the rare gas by separating the rare gas and impurities contained in the exhaust gas via at least two gas separating

Abstract: Oxygen starting material, which already contains heavy isotopes of oxygen, is enriched in the heavy isotopes of oxygen by means of cryogenic distillation in an oxygen distillation column system 1A, then water containing a high concentration of the above-mentioned heavy isotopes of oxygen is formed by adding hydrogen to the enriched product and reacting them in a reactor system 3A. This formed water is distilled in the water distillation column system 4A and, thereby, heavy oxygen water enriched in the above-mentioned heavy isotopes of oxygen is produced.

Abstract: Stable isotope atoms present in the form of stable isotope compounds, for example, 13C present in the form of 13CO, are separated by distillation using a distillation column packed orderly with a formed packing, and preferably by distillation using a distillation column packed with a “promoting-fluid-dispersion type” structured packing.

Abstract: An electrophotographic photoreceptor comprising a conductive support and a photosensitive layer which comprises a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material, the charge generation material comprising a phthalocyanine composition (A) which comprises a phthalocyanine, and the charge transport material comprising a benzidine derivative (B) represented by the following general formula (I) ##STR1## wherein each R.sup.1 independently is a halogen atom, an alkyl group, an alkoxy group, an aryl group, a fluoroalkyl group or a fluoroalkoxy group, each R.sup.2 independently is hydrogen atom or an alkyl group, m is an integer of 0 to 5, and when m is an integer of 2 to 5, the groups R.sup.1 are identical with or different from each other, and a coating solution for production of charge transport layers which contains the benzidine derivative (B).

Abstract: Disclosed is a phthalocyanine composition which comprises having clear diffraction peaks at 17.9.degree., 24.0.degree., 26.2.degree. and 27.2.degree. of Bragg angles (2.theta..+-.0.2.degree.) in an X-ray diffraction spectrum with Cu K.alpha., a process for preparing the same, an electrophotographic photoreceptor using the same and a coating solution for forming a charge generation layer containing the same.

Abstract: Polyimides satisfying the requirements (a), (b) and (c) among the requirements described below, polyimides satisfying the requirements (b), (c) and (d), and polyimides satisfying the requirements (a), (b), (c) and (d) are excellent in transparency, isotropy and resistance to cracking (no crack is formed in the formation of a multilayer film, so that the multilayer formation is easy, namely, the polyimides are good in processability) and can give optical parts excellent in optical characteristics:(a) the difference between the refractive index in TE mode and that in TM mode is 0.02 or less,(b) the glass transition temperature (Tg) is 250.degree. C or higher,(c) the optical transmission loss at a wavelength of 0.7 to 1.6 .mu.m is 1 dB/cm or less, and(d) the fluorine content is 22.6% by weight or less.

Abstract: Disclosed is a phthalocyanine composition which comprises having clear diffraction peaks at 17.9.degree., 24.0.degree., 26.2.degree. and 27.2.degree. of Bragg angles (2.theta..+-.0.2.degree.) in an X-ray diffraction spectrum with Cu K.alpha., a process for preparing the same, an electrophotographic photoreceptor using the same and a coating solution for forming a charge generation layer containing the same.

Abstract: There is disclosed a composition for use in the formation of an active light waveguide comprising a fluorinated polyamic acid and an electro-optical material. The active light waveguide is manufactured by subjecting the fluorinated polyamic acid to imide ring closure into a fluorinated polyimide, and orienting the electro-optical material. The active light waveguide fabricated by using the composition for use in the formation of the active light waveguide can provide excellent electro-optical effect. The active light waveguide is extremely thermally stable and suitable to manufacture of electro-optical devices.

Abstract: Disclosed are a phthalocyanine composition having main diffraction peaks at 7.5.degree., 22.5.degree., 24.3.degree., 25.3.degree. and 28.6.degree. of Bragg angles (2.theta..+-.0.2.degree.) in an X-ray powder diffraction spectrum with Cu K.alpha. radiation, a process for preparing the same, an electrophotographic photoreceptor using the same and a coating solution for a charge generation layer containing the same. The composition is made from a mixture of a titanylphthalocyanine and a halogenated group IIIA metal phthalocyanine which has been made amorphous by a strong mineral acid and crystallized from an organic solvent.