Patents by Inventor Yumi Nakagawa

Yumi Nakagawa 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: 5707601
    Abstract: The present invention relates to a process for preparing zeolites having the MTT crystal structure, such as zeolites SSZ-32 and ZSM-23, using small, neutral amines capable of forming the zeolite, the amine containing (a) only carbon, nitrogen and hydrogen atoms, (b) one primary, secondary or tertiary, but not quaternary, amino group, and (c) a tertiary nitrogen atom, at least one tertiary carbon atom, or a nitrogen atom bonded directly to at least one secondary carbon atom (such as isobutylamine, diisobutylamine, diisopropylamine or trimethylamine), wherein the process is conducted in the absence of a quaternary ammonium compound.
    Type: Grant
    Filed: March 4, 1996
    Date of Patent: January 13, 1998
    Assignee: Chevron U.S.A. Inc.
    Inventor: Yumi Nakagawa
  • Patent number: 5683572
    Abstract: The present invention relates to new crystalline zeolite SSZ-44 prepared by processes for preparing crystalline molecular sieves, particularly large pore zeolites, using a N,N-diethyl-cis-2,6-dimethyl piperidinium cation templating agent.
    Type: Grant
    Filed: August 27, 1996
    Date of Patent: November 4, 1997
    Assignee: Chevron U.S.A. Inc.
    Inventor: Yumi Nakagawa
  • Patent number: 5645812
    Abstract: The present invention relates to a process for preparing the zeolite ZSM-11 using 3,5-dimethylpiperidinium compounds as an organic templating agent, and to the zeolite ZSM-11 in the pure phase form.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: July 8, 1997
    Assignee: Chevron U.S.A. Inc.
    Inventor: Yumi Nakagawa
  • Patent number: 5641393
    Abstract: A crystalline zeolite high-silica SSZ-37 is prepared using a N,N-dimethyl-4-azoniatricyclo [5.2.2.0.sup.(2,6) ] undec-8-ene cation as a template wherein said zeolite is used in hydrocarbon conversion processes.
    Type: Grant
    Filed: August 8, 1995
    Date of Patent: June 24, 1997
    Assignee: Chevron U.S.A. Inc.
    Inventor: Yumi Nakagawa
  • Patent number: 5580540
    Abstract: The present invention relates to new crystalline zeolite SSZ-44 prepared by processes for preparing crystalline molecular sieves, particularly large pore zeolites, using a N,N-diethyl-cis-2,6-dimethyl piperidinium cation templating agent.
    Type: Grant
    Filed: December 1, 1995
    Date of Patent: December 3, 1996
    Assignee: Chevron U.S.A. Inc.
    Inventor: Yumi Nakagawa
  • Patent number: 5501848
    Abstract: Molecular sieves, particularly metalloaluminophosphates are prepared using templates derived from a 4-azonia-tricyclo 5.2.n.0.sup.2,6 !alkene family of compounds. The templates may be prepared in a series of reaction steps which include a Diels-Alder reaction between a diene and a dienophile.
    Type: Grant
    Filed: July 5, 1994
    Date of Patent: March 26, 1996
    Assignee: Chevron U.S.A. Inc.
    Inventor: Yumi Nakagawa
  • Patent number: 5425933
    Abstract: Molecular sieves, particularly zeolites, are prepared using heterobridged aza-polycyclic templates. The templates may be prepared in a series of reaction steps which include a Diels-Alder reaction between a diene and a dienophile.
    Type: Grant
    Filed: February 8, 1994
    Date of Patent: June 20, 1995
    Assignee: Chevron Research and Technology Company, A Division of Chevron U.S.A. Inc.
    Inventor: Yumi Nakagawa
  • Patent number: 5391287
    Abstract: The present invention relates to new crystalline zeolite SSZ-35 prepared by processes for preparing crystalline molecular sieves, particularly large pore zeolites, using conformationally constrained aza-polycyclic ring system templating agents.
    Type: Grant
    Filed: December 1, 1993
    Date of Patent: February 21, 1995
    Assignee: Chevron Research and Technology Company
    Inventor: Yumi Nakagawa
  • Patent number: 5340563
    Abstract: An improved method of synthesizing large pore zeolites is disclosed and claimed. The method comprises preparing a reaction mixture containing a source zeolite on alkali metal, nitrogen containing organic cation, a source of silica, and water, and having the following composition in terms of the mole ratios:______________________________________ M.sup.+ /SiO.sub.2 = 0.01-1.00 OH.sup.- /SiO.sub.2 = 0.15-0.80 H.sub.2 O/SiO.sub.2 = 20-120 Q/SiO.sub.2 = 0.10-1.00 SiO.sub.2 /Y.sub.2 O.sub.3 = Greater Than 8 ______________________________________wherein M.sup.+ is an alkali metal not supplied by the source zeolite, Q is an organic template, and Y is a mixture of aluminum from the source zeolite, wherein said source zeolite contains soda lite substructures having tetrahedra atom densities of less than about 15 TO.sub.2 per 1000 .ANG..sup.3 ; maintaining the reaction mixture at crystallization temperature until crystals are formed; and recovering the crystals.
    Type: Grant
    Filed: June 30, 1992
    Date of Patent: August 23, 1994
    Assignee: Chevron Research and Technology Company
    Inventors: Stacey I. Zones, Yumi Nakagawa
  • Patent number: 5316753
    Abstract: The present invention relates to new crystalline zeolite SSZ-35 prepared by processes for preparing crystalline molecular sieves, particularly large pore zeolites, using conformationally constrained aza-polycyclic ring system templating agents.
    Type: Grant
    Filed: October 9, 1992
    Date of Patent: May 31, 1994
    Assignee: Chevron Research and Technology Company
    Inventor: Yumi Nakagawa
  • Patent number: 5281407
    Abstract: Molecular sieves, particularly zeolites, are prepared using templates derived from a 4-azonia-tricyclo[5.2.n.0.sup.2,6 ]alkene family of compounds. The templates may be prepared in a series of reaction steps which include a Diels-Alder reaction between a diene and a dienophile.
    Type: Grant
    Filed: June 30, 1992
    Date of Patent: January 25, 1994
    Assignee: Chevron Research and Technology Company
    Inventor: Yumi Nakagawa
  • Patent number: 5273736
    Abstract: The present invention relates to a process for preparing crystalline molecular sieves, particularly large pore zeolites, which comprises contacting active sources of one or more oxides selected from the group consisting of monovalent element oxides, divalent element oxides, trivalent element oxides, tetravalent element oxides, and pentavalent element oxides with an organocation templating agent derived from a 9-azabicyclo[3.3.1]nonane.
    Type: Grant
    Filed: October 9, 1992
    Date of Patent: December 28, 1993
    Assignee: Chevron Research and Technology Company
    Inventor: Yumi Nakagawa
  • Patent number: 5271922
    Abstract: The present invention relates to a process for preparing crystalline molecular sieves, particularly large pore zeolites, which comprises contacting active sources of one or more oxides selected from the group consisting of monovalent element oxides, divalent element oxides, trivalent element oxides, tetravalent element oxides, and pentavalent element oxides with an organocation templating agent derived from sparteine.
    Type: Grant
    Filed: October 9, 1992
    Date of Patent: December 21, 1993
    Assignee: Chevron Research and Technology Company
    Inventor: Yumi Nakagawa
  • Patent number: 5271921
    Abstract: The present invention relates to a process for preparing crystalline molecular sieves, particularly large pore zeolites, which comprises contacting active sources of one or more oxides selected from the group consisting of monovalent element oxides, divalent element oxides, trivalent element oxides, tetravalent element oxides, and pentavalent element oxides with an organocation templating agent derived from a 3,7-diazabicyclo[3.3.1]nonane.
    Type: Grant
    Filed: October 9, 1992
    Date of Patent: December 21, 1993
    Assignee: Chevron Research and Technology Company
    Inventor: Yumi Nakagawa
  • Patent number: 5268161
    Abstract: The present invention relates to a process for preparing crystalline molecular sieves, particularly large pore zeolites, which comprises contacting active sources of one or more oxides selected from the group consisting of monovalent element oxides, divalent element oxides, trivalent element oxides, tetravalent element oxides, and pentavalent element oxides with an organocation templating agent derived from 1,3,3,8,8-pentamethyl-3-azoniabicyclo[3.2.1]octane.
    Type: Grant
    Filed: October 9, 1992
    Date of Patent: December 7, 1993
    Assignee: Chevron Research and Technology Company
    Inventor: Yumi Nakagawa
  • Patent number: 5254514
    Abstract: A crystalline zeolite SSZ-37 is prepared using a N,N-dimethyl-4-azoniatricyclo [5.2.2.0.sup.(2,6) ] undec-8-ene cation as a template wherein said zeolite is used in hydrocarbon conversion processes.
    Type: Grant
    Filed: June 30, 1992
    Date of Patent: October 19, 1993
    Assignee: Chevron Research and Technology Company
    Inventor: Yumi Nakagawa
  • Patent number: 5225179
    Abstract: A method for synthesizing molecular sieves is disclosed. The method comprises preparing an aqueous mixture comprising:a) a source zeolite, wherein said source zeolite contains sodalite substructures and has a tetrahedra atom density of less than about 15 TO.sub.2 per 1000 .ANG..sup.3, and wherein said source zeolite has a silica/alumina mole ratio greater than 200; an alkali metal oxide; and an organic template, and wherein said aqueous mixture has a composition in terms of mole ratios of oxides falling within the following ranges:______________________________________ M+/SiO.sub.2 = 0.01-1.00 OH-/SiO.sub.2 = 0.15-0.80 H.sub.2 O/SiO.sub.2 = 20-120 Q/SiO.sub.2 = 0.10-1.00 SiO.sub.2 /Y.sub.2 O.sub.
    Type: Grant
    Filed: August 27, 1992
    Date of Patent: July 6, 1993
    Assignee: Chevron Research and Technology Company
    Inventors: Stacey I. Zones, Yumi Nakagawa