Patents by Inventor Tokuji Sakai

Tokuji Sakai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4954326
    Abstract: A process for producing a crystalline aluminosilicate zeolite characterized by having (a) a silica/alumina mole ratio of from 10 to 100, (b) X-ray lattice distances d shown in Table A of the specification, and (c) a specific n-hexane adsorption, under limited measuring conditions, of at least 0.07 g/g, which comprises maintaining a silica source, an alumina source, and a zeolite selected from zeolites ZSM-5 and zeolites having said characteristics, in an aqueous solution containing 1 to 200 millimoles, per gram of said zeolite, of an alkali metal hydroxide under such temperature, pressure and time conditions as to produce a crystalline aluminosilicate zeolite; and a crystalline aluminosilicate zeolite characterized by having aforesaid properties (a) to (c) and (d) a (2-methylpentane/cyclohexane) adsorption ratio of from 1.1 to 1.6.
    Type: Grant
    Filed: July 12, 1989
    Date of Patent: September 4, 1990
    Assignee: Teijin Petrochemical Industries, Ltd.
    Inventors: Tamio Onodera, Tokuji Sakai, Yasuo Yamasaki, Koji Sumitani
  • Patent number: 4709088
    Abstract: A process for producing 2,6-naphthalenedicarboxylic acid which comprises oxidizing 2,6-diisopropylnaphthalene or its oxidation product as a starting material with molecular oxygen in a reaction medium containing at least 50% by weight of an aliphatic monocarboxylic acid having not more than 3 carbon atoms in the presence of an oxidation catalyst comprising (A) at least one heavy metal element selected from the group consisting of cobalt and manganese, and (B) bromine element, the 2,6-diisopropylnaphthalene and/or its oxidation product being used in a proportion of 0.1 to 5 moles per gram-atom of the heavy metal element of the oxidation catalyst.
    Type: Grant
    Filed: July 15, 1986
    Date of Patent: November 24, 1987
    Assignee: Teijin Petrochemical Industries, Ltd.
    Inventors: Isao Hirose, Tamio Amemiya, Tokuji Sakai
  • Patent number: 4695667
    Abstract: A novel crystalline aluminosilicate zeolite characterized by having a composition of the following general formula expressed in terms of the mole ratios of oxides in the anhydrous statexM.sub.2/n O.Al.sub.2 O.sub.3.ySiO.sub.2wherein M represents at least one cation having a valence of n, x is a number between 0.5 and 4, and y is a number of at least 10, and having a specific X-ray diffraction pattern. Said crystalline aluminosilicate zeolite can be produced by maintaining a mixture of a water-soluble alkali metal compound, an N,N,N,N',N',N'-hexamethyl-1,6-hexane diammonium compound, a compound capable of giving silica under the reaction conditions, a compound capable of giving alumina under the reaction conditions and water, at a temperature of at least 80.degree. C. for a period sufficient to form crystals, and is useful as a catalyst for, for example, transalkylation or alkylation reaction of toluene, isomerization of xylene, isomerization of ethylbenzene to xylenes, etc.
    Type: Grant
    Filed: February 26, 1985
    Date of Patent: September 22, 1987
    Assignee: Teijin Petrochemical Industries, Ltd.
    Inventors: Koji Sumitani, Tokuji Sakai, Yasuo Yamasaki, Tamio Onodera
  • Patent number: 4557919
    Abstract: A process for producing a crystalline zeolite TPZ-12, which comprises maintaining a starting mixture at a temperature of at least 80.degree. C. for a period sufficient to produce zeolite crystals, said starting mixture consisting of(a) a substance capable of yielding silica under the reaction conditions,(b) a water-soluble alkali metal compound,(c) water, and(d) a diammonium compound represented by the following general formula ##STR1## wherein R.sub.1 and R.sub.2 are identical or different and each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, p and q are identical or different and each represents an integer of 4 or 5, n is 4, 5 or 6, and y represents an anion having a valence of m, and additionally, if desired,(e) a substance capable of yielding alumina under the reaction conditions,in the particular quantities.
    Type: Grant
    Filed: April 10, 1984
    Date of Patent: December 10, 1985
    Assignee: Teijin Petrochemical Industries Ltd.
    Inventors: Koji Sumitani, Tokuji Sakai, Yasuo Yamasaki, Tamio Onodera
  • Patent number: 4524055
    Abstract: A novel crystalline aluminosilicate zeolite characterized by having(a) a silica/alumina mole ratio in the range of from 10 to 100,(b) X-ray lattice distances d shown in Table A in the specification, and(c) a (cyclohexane/n-hexane) adsorption ratio of at least 0.7. This crystalline aluminosilicate zeolite is useful, for example, as a catalyst in the isomerization reaction or transalkylation reaction of alkylbenzenes or alkylnaphthalenes, and can be prepared by heating a crystalline aluminosilicate zeolite ZSM-5 having a silica/alumina mole ratio of from 20 to 300 at a temperature between 80.degree. C. and 250.degree. C. in an aqueous solution containing 0.1 to 1 g, per gram of the ZSM-5 zeolite, of an alkali metal hydroxide.
    Type: Grant
    Filed: February 22, 1983
    Date of Patent: June 18, 1985
    Assignee: Teijin Petrochemical Industries Ltd.
    Inventors: Tamio Onodera, Tokuji Sakai, Yasuo Yamasaki, Koji Sumitani
  • Patent number: 4485185
    Abstract: A catalyst composition comprising (i) a crystalline aluminosilicate selected from the group consisting of zeolite ZSM-5, zeolite ZSM-11, zeolite ZSM-12, zeolite ZSM-35 and zeolite ZSM-38 and having a silica/alumina mole ratio of 20 to 1,000; and (ii) at least two metals which are (a) platinum and (b) at least one other metal selected from the group consisting of titanium, chromium, zinc, gallium, germanium, strontium, yttrium, zirconium, molybdenum, palladium, tin, barium, cerium, tungsten, osmium, lead, cadmium, mercury, indium, lanthanum and beryllium. This catalyst composition is useful particularly for the isomerization of aromatic hydrocarbons and reforming of naphtha.
    Type: Grant
    Filed: September 15, 1983
    Date of Patent: November 27, 1984
    Assignee: Teijin Petrochemical Industries, Ltd.
    Inventors: Tamio Onodera, Tokuji Sakai, Yasuo Yamasaki, Koji Sumitani
  • Patent number: 4377718
    Abstract: In a process for producing p-xylene which comprises catalytically methylating toluene with a methylating agent in the gaseous phase, the improvement wherein(a) said methylation is carried out continuously in a multi-stage reaction system consisting of a plurality of separate series-connected fixed catalyst layers without separating the resulting xylenes in an intermediate stage,(b) said toluene is fed together with hydrogen gas into only the first-stage fixed catalyst layer and passed successively through the subsequent fixed catalyst layers, the amount of toluene fed being such that the total weight hourly space velocity of toluene is from 1 to 300 hr.sup.-1,(c) said methylating agent is fed into each of said fixed catalyst layers, if desired together with hydrogen gas, the amount of the methylating agent fed into each catalyst layer being 0.
    Type: Grant
    Filed: July 21, 1981
    Date of Patent: March 22, 1983
    Assignee: Teijin Petrochemical Industries Ltd.
    Inventors: Kimihiko Sato, Tokuji Sakai, Yasuo Yamasaki, Tamio Onodera, Koji Sumitani
  • Patent number: 4331822
    Abstract: In a process for isomerization of xylenes which comprises contactng an aromatic hydrocarbon stock mainly containing xylene isomers not attaining a thermodynamic equilibrium composition with a catalyst composition containing a crystalline aluminosilicate at an elevated temperature in the vapor phase in the presence of hydrogen, the improvement wherein said catalyst composition comprises a crystalline aluminosilicate having a silica/alumina mole ratio of at least 10 and contains at least two metals which are (a) platinum and (b) at least one metal selected from the group consisting of titanium, chromium, zinc, gallium, germanium, strontium, yttrium, zirconium, molybdenum, palladium, tin, barium, cesium, cerium, tungsten, osmium, lead, cadmium, mercury, indium, lanthanum, beryllium, lithium and rubidium.
    Type: Grant
    Filed: March 25, 1980
    Date of Patent: May 25, 1982
    Assignee: Teijin Petrochemical Industries Ltd.
    Inventors: Tamio Onodera, Tokuji Sakai, Yasuo Yamasaki, Koji Sumitani
  • Patent number: 4320242
    Abstract: In a process for dealkylating a hydrocarbon material containing at least one alkyl-substituted aromatic hydrocarbon having bonded to the aromatic ring at least one alkyl group with at least 2 carbon atoms in the gaseous phase in the presence of hydrogen using a hydro-dealkylation catalyst, the improvement wherein (a) said hydro-dealkylation catalyst is composed of a crystalline aluminosilicate having a silica/alumina mole ratio of from 20 to 200 and containing a noble metal selected from platinum, palladium, rhodium and iridium, and (b) said dealkylation is carried out at a temperature of 250.degree. C. to 420.degree. C. and a pressure of not more than 100 psig, thereby selectively removing said alkyl group containing at least 2 carbon atoms from said alkyl-substituted aromatic hydrocarbon.
    Type: Grant
    Filed: February 4, 1980
    Date of Patent: March 16, 1982
    Assignee: Teijin Petrochemical Industries Ltd.
    Inventors: Tamio Onodera, Tokuji Sakai, Yasuo Yamasaki, Koji Sumitani, Minekazu Sueoka
  • Patent number: 4300014
    Abstract: A process for isomerizing xylenes, which comprisescontacting an aromatic hydrocarbon feedstock containing mainly a xylene isomeric mixture containing ethylbenzene with a catalyst of a palladium-containing crystalline aluminosilicate in the vapor phase in the presence of hydrogen to continuously isomerize xylenes and simultaneously de-ethylate the ethylbenzene selectively;interrupting the isomerization reaction;introducing an oxygen-containing gas into a bed of the catalyst in which coke has been deposited during the isomerization reaction, to contact the catalyst with the oxygen-containing gas;burning off the coke deposits on the catalyst with the oxygen-containing gas by gradually increasing the temperature of introduction of the oxygen-containing gas from not more than 200.degree. C. to a temperature in the range of 330.degree. to 390.degree. C. with no part of the catalyst bed exceeding a maximum temperature of 400.degree. C. while controlling the hot spot temperature of the catalyst bed not to exceed 50.
    Type: Grant
    Filed: November 4, 1980
    Date of Patent: November 10, 1981
    Assignee: Teijin Petrochemical Industries Ltd.
    Inventors: Yasuo Yamasaki, Tokuji Sakai, Tamio Onodera, Kiji Sumitani