Patents by Inventor Seishi Yajima

Seishi Yajima 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: 4556526
    Abstract: A process for producing a sintered ceramic body, which comprises heating a semi-inorganic block copolymer at a temperature of from 500.degree. to 2300.degree. C. in an environment of vacuum or inert gases, reducing gases or hydrocarbon gases, said copolymer comprising polycarbosilane blocks having a main-chain skeleton composed mainly of carbosilane units of the formula (Si--CH.sub.2) and zirconoxane units of the formula (Zr--O); and shaping the heated product, and simultaneously with, or after, the shaping of the heated product, sintering the shaped product at a temperature of from 800.degree. C. to 2300.degree. C. in an environment of vacuum or inert gases, reducing gases or hydrocarbon gases; and a sintered ceramic body consisting substantially of Si, Zr and C and optionally of O, said sintered body being composed substantially of(1) an amorphous material consisting substantially of Si, Zr and C and optionally of O, or(2) an aggregate consisting subtantially of ultrafine crystalline particles of .beta.
    Type: Grant
    Filed: March 20, 1981
    Date of Patent: December 3, 1985
    Assignee: UBE Industries, Ltd.
    Inventors: Seishi Yajima, Kiyohito Okamura, Yoshio Hasegawa, Takemi Yamamura
  • Patent number: 4515742
    Abstract: Continuous inorganic fibers consisting substantially of Si, Zr and C and optionally of O, said fibers being composed of (1) an amorphous material consisting substantially of Si, Zr and C and optionally of O, or (2) an aggregate consisting substantially of ultrafine crystalline particles of .beta.-SiC, ZrC, a solid solution of .beta.-SiC and ZrC and ZrC.sub.1-x wherein 0<x<1 and having a particle diameter of not more than 500.ANG., in which amorphous SiO.sub.2 and ZrO.sub.2 sometimes exist in the neighborhood of these ultrafine crystalline particles, or (3) a mixture of said amorphous material (1) and said aggregate (2) of ultrafine crystalline particles. The aforesaid continuous inorganic fibers can be produced by the following steps: a first step of preparing a semi-inorganic block copolymer comprising polycarbosilane blocks having a main chain skeleton composed mainly of carbosilane units of the formula --Si--CH.sub.
    Type: Grant
    Filed: December 15, 1981
    Date of Patent: May 7, 1985
    Assignee: UBE Industires, Ltd.
    Inventors: Seishi Yajima, deceased, Akiko Noda, heir, Kiyohito Okamura, Yoshio Hasegawa, Takemi Yamaura
  • Patent number: 4455414
    Abstract: A process for producing an organometallic copolymer composed of a polycarbosilane portion and a polymetallosiloxane portion crosslinked with each other, which comprises reacting (1) a polycarbosilane having a main chain skeleton composed mainly of carbosilane units of the formula --Si--CH.sub.2 --, with (2) a polymetallosiloxane having a main chain skeleton composed of metalloxane units of the formula --M--O-- wherein M represents Ti or Zr and siloxane units of the formula --Si--O--, in an organic solvent in an inert atmosphere thereby to bond at least some of the silicon atoms of said polycarbosilane to at least some of the metal atoms M and/or silicon atoms of said polymetallosiloxane through an oxygen atom; and the organometallic copolymer obtained by the aforesaid process.
    Type: Grant
    Filed: January 6, 1982
    Date of Patent: June 19, 1984
    Assignee: UBE Industries, Ltd.
    Inventors: Seishi Yajima, Kiyohito Okamura, Yoshio Hasegawa, Takemi Yamamura
  • Patent number: 4399232
    Abstract: Continuous inorganic fibers consisting substantially of Si, Ti and C and optionally of O, said fibers being composed of (1) an amorphous material consisting substantially of Si, Ti and C and optionally of O, or (2) an aggregate consisting substantially of ultrafine crystalline particles of .beta.-SiC, TiC, a solid solution of .beta.-SiC and TiC and TiC.sub.1-x wherein 0<x<1 and having a particle diameter of not more than 500 A, in which amorphous SiO.sub.2 and TiO.sub.2 sometimes exist in the neighborhood of these ultrafine crystalline particles, or (3) a mixture of said amorphous material (1) and said aggregate (2) of ultrafine crystalline particles. The aforesaid continuous inorganic fibers can be produced by the following steps: a first step of preparing a semi-inorganic block copolymer comprising polycarbosilane blocks having a main chain skeleton composed mainly of carbosilane units of the formula --Si-CH.sub.
    Type: Grant
    Filed: May 26, 1982
    Date of Patent: August 16, 1983
    Assignee: UBE Industries, Ltd.
    Inventors: Seishi Yajima, Kiyohito Okamura, Yoshio Hasegawa, Takemi Yamamura
  • Patent number: 4361679
    Abstract: A process for producing a heat-resistant and moisture-resistant polyborometallosiloxane, which comprises adding a metal compound and a compound capable of easily forming a complex with the metal compound to an organoborosiloxane, the metal in said metal compound being at least one member of the group consisting of Ti, Zr, V, P, Al, Fe, Cr, Co, Ni, Ge, Sn, As, Mg, Pb and Sb; and heating the resulting mixture to a temperature of 550.degree. C. or lower to bond the metal atom to the silicon atom and/or the boron atom through an oxygen atom.
    Type: Grant
    Filed: June 30, 1981
    Date of Patent: November 30, 1982
    Assignees: NTN Toyo Bearing Co., Ltd., Seishi Yajima
    Inventors: Seishi Yajima, Kiyohito Okamura, Toetsu Shishido
  • Patent number: 4361691
    Abstract: A process for producing a heat-resistant compound, which comprises adding a diamine to an organic solvent-soluble metallosiloxane compound whose main chain consists of siloxane bonds --Si--O-- and metalloxane bonds --M--O-- wherein M represents at least one element selected from the group consisting of Ti, Zr, V, P, Al, Fe, Cr, Co, Ni, Ge, Sn, As, Mg, Pb and Sb, and heating the mixture to 50.degree. to 450.degree. C. in the presence or absence of an organic solvent.
    Type: Grant
    Filed: May 5, 1981
    Date of Patent: November 30, 1982
    Assignees: NTN Toyo Bearing Co., Ltd., Seishi Yajima
    Inventors: Seishi Yajima, Kiyohito Okamura, Toetsu Shishido
  • Patent number: 4359559
    Abstract: A polymetallocarbosilane having a number average molecular weight of 700 to 100,000 derived from a polycarbosilane having a number average molecular weight of 200 to 10,000 and containing a main-chain skeleton represented mainly by the general formula ##STR1## wherein R represents a hydrogen atom, a lower alkyl group or a phenyl group,and an organometallic compound represented by the general formulaMX.sub.4Wherein M represents Ti or Zr, and X represents an alkoxy group having 1 to 20 carbon atoms, a phenoxy group or an acetylacetoxy group,at least one of the silicon atoms of the polymetallocarbosilane being bonded to the metal atom (M) through an oxygen atom, the ratio of the total number of the structural units --Si--CH.sub.2 -- to the total number of the structural units --M--O-- in the polymetallocarbosilane being in the range of from 2:1 to 200:1; and a process for production thereof.
    Type: Grant
    Filed: November 20, 1980
    Date of Patent: November 16, 1982
    Assignee: UBE Industries, Ltd.
    Inventors: Seishi Yajima, Kiyohito Okamura, Yoshio Hasegawa, Takemi Yamamura
  • Patent number: 4358576
    Abstract: An organometallic polymer of which the main-chain skeleton consists of a Si-CH.sub.2 bond and a V-O bond and which partly contains a vanadiosiloxane bond, the ratio of the number of silicon atoms to that of vanadium atoms being in the range of from 3:1 to 1000:1, the side-chain group directly bonded to the silicon atom being selected from the group consisting of hydrogen, methyl, ethyl and phenyl, and the vanadium atom being bonded to the silicon atom through an oxygen atom with substantially no side-chain organic group present which is directly bonded to the vanadium atom.
    Type: Grant
    Filed: April 15, 1981
    Date of Patent: November 9, 1982
    Assignees: Kurosaki Refractories, Co., Ltd., Seishi Yajima
    Inventors: Seishi Yajima, Kiyohito Okamura, Toetsu Shishido, Kazushige Fukuda
  • Patent number: 4347347
    Abstract: A process for producing an organometallic copolymer composed of a polycarbosilane portion and a polymetallosiloxane portion crosslinked with each other, which comprises reacting (1) a polycarbosilane having a main chain skeleton composed mainly of carbosilane units of the formula --Si-CH.sub.2 --, with (2) a polymetallosiloxane having a main chain skeleton composed of metalloxane units of the formula --M-O-- wherein M represents Ti or Zr and siloxane units of the formula --Si-O--, in an organic solvent in an inert atmosphere thereby to bond at least some of the silicon atoms of said polycarbosilane to at least some of the metal atoms M and/or silicon atoms of said polymetallosiloxane through an oxygen atom; and the organometallic copolymer obtained by the aforesaid process.
    Type: Grant
    Filed: June 18, 1980
    Date of Patent: August 31, 1982
    Assignee: Ube Industries, Ltd.
    Inventors: Seishi Yajima, Kiyohito Okamura, Yoshio Hasegawa, Takemi Yamamura
  • Patent number: 4342712
    Abstract: Continuous inorganic fibers consisting substantially of Si, Ti and C and optionally of O, said fibers being composed of (1) an amorphous material consisting substantially of Si, Ti and C and optionally of O, or (2) an aggregate consisting substantially of ultrafine crystalline particles of .beta.-SiC, TiC, a solid solution of .beta.-SiC and TiC and TiC.sub.1-x wherein 0<x<1 and having a particle diameter of not more than 500 A, in which amorphous SiO.sub.2 and TiO.sub.2 sometimes exist in the neighborhood of these ultrafine crystalline particles, or (3) a mixture of said amorphous material (1) and said aggregate (2) of ultrafine crystalline particles. The aforesaid continuous inorganic fibers can be produced by the following steps: a first step of preparing a semi-inorganic block copolymer comprising polycarbosilane blocks having a main chain skeleton composed mainly of carbosilane units of the formula --Si--CH.sub.
    Type: Grant
    Filed: June 18, 1980
    Date of Patent: August 3, 1982
    Assignee: UBE Industries, Ltd.
    Inventors: Seishi Yajima, Kiyohito Okamura, Yoshio Hasegawa, Takemi Yamamura
  • Patent number: 4336215
    Abstract: A process for producing a sintered ceramic body, which comprises heating a semi-inorganic block copolymer at a temperature of from 500.degree. to 2300.degree. C. in an environment of vacuum or inert gases, reducing gases or hydrocarbon gases, said copolymer comprising polycarbosilane blocks, having a main-chain skeleton composed mainly of carbosilane units of the formula --Si--CH.sub.2 -- and titanoxane units of the formula --Ti--O--; and shaping the heated product, and simultaneously with, or after, the shaping of the heated product, sintering the shaped product at a temperature of from 800.degree. C. to 2300.degree. C. in an environment of vacuum or inert gases, reducing gases or hydrocarbon gases; and a sintered ceramic body consisting substantially of Si, Ti and C and optionally of O, said sintered by being composed substantially of(1) an amorphous material consisting substantially of Si, Ti and C and optionally of O, or(2) an aggregate consisting substantially of ultrafine crystalline particles of .beta.
    Type: Grant
    Filed: November 25, 1980
    Date of Patent: June 22, 1982
    Assignee: Ube Industries, Ltd.
    Inventors: Seishi Yajima, Kiyohito Okamura, Yoshio Hasegawa, Takemi Yamamura
  • Patent number: 4334051
    Abstract: A polyvanadiosiloxane being a polymer of which the main chain skeleton consists of Si-O bonds and V-O bonds, characterized by side chains directly attached to the silicon atom being at least one organic group selected from the group consisting of a lower alkyl group, phenyl group, fluoroalkyl group, nitrile group and vinyl group, the vanadium atom being attached to the silicon atom through the oxygen atom and no organic side chain group directly attached to the vanadium atom being present in substance; and a process for the production of a polyvanadiosiloxane which comprises reacting an oily polysiloxane having the main chain skeleton consisting of units of ##STR1## wherein R.sub.1 and R.sub.2 may be the same or different and stand for a lower alkyl group, phenyl group, fluoroalkyl group, nitrile group or vinyl group, and a vanadium compound by heating at a temperature of 450.degree. C. or less under conditions capable of forming a complex of the vanadium compound.
    Type: Grant
    Filed: November 26, 1980
    Date of Patent: June 8, 1982
    Assignee: Seishi Yajima
    Inventors: Seishi Yajima, Kiyohito Okamura, Toetsu Shishido
  • Patent number: 4289720
    Abstract: A process for producing a thermal-resistant ceramic fired body is disclos As an additive for ceramic powder is used at least one specified organosilicon polymer selected from the group consisting of [I] organopolysiloxanes, [II] organosiloxane copolymers, [III] polycarbosiloxanes and [IV] nitrogen-containing organosilicon polymers.
    Type: Grant
    Filed: March 3, 1980
    Date of Patent: September 15, 1981
    Assignee: The Foundation: The Research Institute for Special Inorganic Materials
    Inventors: Seishi Yajima, Toetsu Shishido, Kiyohito Okamura, Hideo Kayano, Josaburo Hayashi, Hiroshi Kobayashi
  • Patent number: 4283376
    Abstract: A process for producing polycarbosilane partly containing siloxane bonds, which comprises adding 0.01 to 15% by weight of polyborosiloxane having phenyl groups in at least a part of the side chains of Si with its skeletal structure being composed of B, Si and O to a polysilane having the structure ##STR1## wherein n is at least 3, and R.sub.1 and R.sub.2, independently from each other, represent methyl, ethyl, phenyl or hydrogen; and heating the polymer mixture in an atmosphere inert to the reaction thereby to polymerize it. The polycarbosilane is converted into silicon carbide fibers by first preparing a spinning dope; subjecting the dope to a treatment of rendering it infusible under tension or under no tension and firing the treated dope in a vacuum or in an inert atmosphere.
    Type: Grant
    Filed: June 12, 1979
    Date of Patent: August 11, 1981
    Assignee: The Research Institute for The Foundation: Special Inorganic Materials
    Inventors: Seishi Yajima, Kiyohito Okamura, Yoshio Hasegawa
  • Patent number: 4279654
    Abstract: This invention relates to a process for producing crystallized glass having superior mechanical properties and thermal properties, which comprises (1) coating glass in the form of a powder or molded article with an organometallic polymer, said polymer being soluble in an organic solvent and having a skeleton comprising (a) titanoxane linkages --Ti--O-- or zirconoxane linkages --Zr--O-- or both and (b) siloxane linkages --Si--O-- in which most of the silicon atoms have as a side chain at least one organic group selected from alkyl and phenyl groups, and optionally (c) boroxane linkages --B--O-- or aluminoxane linkages --Al--O-- or both; and (2) firing the resulting polymer-coated glass in an oxidizing atmosphere to crystallize at least a part of the glass. This invention also pertains to a process for producing a ceramics-crystallized glass composite article using the aforesaid crystallized glass.
    Type: Grant
    Filed: May 5, 1980
    Date of Patent: July 21, 1981
    Assignee: The Foundation: The Research Institute for Special Inorganic Materials
    Inventors: Seishi Yajima, Kiyohito Okamura, Toetsu Shishido, Yoshio Hasegawa
  • Patent number: 4267211
    Abstract: A process for producing a corrosion-, heat- and oxidation-resistant shaped rticle which comprises coating a shaped article composed of at least one material selected from metals, carbonaceous substances and ceramics with a coating composition comprising a semi-inorganic compound, and heat-treating the coated article, said semi-inorganic compound being at least one polymer selected from the group consisting of polycarbosilanes and polycarbosiloxanes.
    Type: Grant
    Filed: November 8, 1979
    Date of Patent: May 12, 1981
    Assignee: The Foundation: The Research Institute for Special Inorganic Materials
    Inventors: Seishi Yajima, Kiyohito Okamura, Toetsu Shishido, Yoshio Hasegawa
  • Patent number: 4267210
    Abstract: A method for producing a corrosion-, heat- and oxidation-resistant material hich comprises coating a substrate composed of at least one material selected from metals, carbonaceous substances and ceramics with a semi-inorganic compound, and heat-treating the coated substrate; said semi-inorganic compound being either(1) a modified organoborosiloxane compound obtained by reacting an organoborosiloxane compound with at least one organic compound selected from the group consisting of polyhydric aliphatic alcohols, aromatic alcohols, phenols and aromatic carboxylic acid at a temperature of from 250.degree. to 450.degree.
    Type: Grant
    Filed: July 25, 1979
    Date of Patent: May 12, 1981
    Assignee: The Foundation: The Research Institute for Special Inorganic Materials
    Inventors: Seishi Yajima, Kiyohito Okamura, Toetsu Shishido, Yoshio Hasegawa
  • Patent number: 4264361
    Abstract: This invention relates to a heat-resistant composite magnet comprising 2 to 30% by weight of an organic-inorganic compound binder containing boron and silicon and 70 to 98% by weight of the powder of one or more permanent magnets.This invention further relates to a method for producing a heat-resistant composite magnet, which comprises the steps of (a) adding the powder of one or more permanent magnets to a solution of an organic-inorganic compound binder containing boron and silicon dissolved in an organic solvent; (b) evaporating said solvent; (c) molding the resultant permanent magnet powder covered with said binder under a pressure of 0.1 to 5 tons/cm.sup.2 in the presence or in the absence of a magnetic field of 12,000-5,000 oersted, the molded product being heated at 200.degree.-450.degree. C. during the molding or after the molding; and (d) cooling the molded product.
    Type: Grant
    Filed: May 8, 1979
    Date of Patent: April 28, 1981
    Assignees: Mitsubishi Seiko Kabushiki Kaisha, The Foundation: The Research Institute for Special Inorganic Materials
    Inventors: Seishi Yajima, Masaaki Hamano, Yoshio Hasegawa, Kimiyuki Kamino, Takehiro Yamane
  • Patent number: 4248814
    Abstract: A process for producing a heat-resistant ceramic sintered body, which comses preparing polycarbosilane partly containing siloxane bonds by adding 0.01 to 15% by weight of polyborosiloxane containing phenyl groups in at least a part of the side chains of Si and having a skeletal structure composed of B, Si and O to a polysilane having the structure ##STR1## wherein n is at least 3, and R.sub.1 and R.sub.2, independently from each other, represent methyl, ethyl, phenyl or hydrogen, and heating the polymer mixture in an atmosphere inert to the reaction thereby polymerizing it; mixing said polycarbosilane with a ceramic powder composed of at least one member selected from the group consisting of oxides, carbides, nitrides, borides and silicides; shaping the resulting mixture; and simultaneously with, or after, the shaping of the mixture, sintering the mixture at a temperature of from 800.degree. C. to 2,000.degree. C.
    Type: Grant
    Filed: January 23, 1979
    Date of Patent: February 3, 1981
    Assignee: The Foundation: The Research Institute for Special Inorganic Materials
    Inventors: Seishi Yajima, Kiyohito Okamura, Toetsu Shishido
  • Patent number: 4242487
    Abstract: A heat-resistant semi-inorganic compound useful as a material for various at-resistant materials is produced by reacting an organoborosiloxane compound with at least one of aliphatic polyhydric alcohols, aromatic alcohols, phenols and aromatic carboxylic acids at 250.degree. to 450.degree. C. in an inert atmosphere.
    Type: Grant
    Filed: May 1, 1979
    Date of Patent: December 30, 1980
    Assignee: The Foundation: The Research Institute for Special Inorganic Materials
    Inventors: Seishi Yajima, Kiyohito Okamura, Toetsu Shishido, Yoshio Hasegawa