Patents by Inventor Takamasa Kawakubo

Takamasa Kawakubo 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: 6139989
    Abstract: A high crystallinity powdery graphite is mixed with an organic binder capable of forming a low crystallinity carbon after firing. A high shearing force is applied to the mixture so that a composition is obtained wherein both the components are dispersed in each other under a mechano-chemical reaction. Then a paste of the composition is extruded so that the high crystallinity graphite is highly oriented. A green extrudate of the composition is fired in an inert atmosphere or a non-oxidation atmosphere at a temperature in a range between 500 and 1,100.degree. C. so that the organic binder contained therein is carbonized and a graphite-carbon carbonaceous composite of an amorphous or random layered structure is obtained, which then is ground and used as a cathode for a lithium ion secondary battery.
    Type: Grant
    Filed: February 21, 1996
    Date of Patent: October 31, 2000
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Takamasa Kawakubo, deceased, Masataka Wakihara, Mori Nagayama
  • Patent number: 5391433
    Abstract: A carbon material for electrodes which is a graphite/glass like carbon composite material having a structure in which the crystals of the graphite are oriented in one direction in the matrix of the glass like carbon so as to possess an electrode reaction activity inherent in the graphite crystals, having a maximum pore diameter of 150 .ANG. or less, and having electrolyte non-penetrative properties substantially corresponding to those of the glass like carbon; and a process for preparing a carbon material for electrodes which comprises the steps of highly dispersing, composing and orienting a graphite fine powder of the sufficiently grown crystals in an organic substance which can leave a glass like and less graphitizable carbon when calcined in a non-oxidizing atmosphere, and then calcining and carbonizing the composition.
    Type: Grant
    Filed: November 4, 1992
    Date of Patent: February 21, 1995
    Assignee: Mitsubishi Pencil Kabushiki Kaisha
    Inventors: Takamasa Kawakubo, Yoshihisa Suda
  • Patent number: 5380422
    Abstract: A working micro-electrode with a reference electrode prepared by coating a working micro-electrode with an insulating material except a working electrode portion, forming a silver layer on the coated surface, and then changing a portion of the silver layer into silver chloride which is the reference electrode; a working micro-electrode with a reference electrode and a counter electrode prepared by coating the working micro-electrode with the reference electrode with an insulating material, and then forming the counter electrode on the surface of the insulating material; and methods for preparing these composite micro-electrodes.Heretofore, even if the working electrode is thinly constituted, the merit of the micro-electrode has not been sufficiently utilized, since the reference electrode and the counter electrode have been thick. However, the present invention can solve this problem and can facilitate experiments in which the micro-electrode is necessary.
    Type: Grant
    Filed: June 29, 1992
    Date of Patent: January 10, 1995
    Assignees: Agency of Industrial Science and Technology, Mitsubishi Pencil Kabushiki Kaisha
    Inventors: Akira Negishi, Hiroko Kaneko, Takamasa Kawakubo, Yoshihisa Suda
  • Patent number: 5376251
    Abstract: A carbon micro-sensor electrode is disclosed which is prepared by impregnating, adsorbing or chemically modifying a pure composite carbon wire having many micropores extending to its surface and interior with a reactant such as an enzyme, a metal complex compound, an organic compound or a metabolite; and a method for preparing this carbon micro-sensor electrode is also disclosed.The above-mentioned electrode can be used for a long period of time, since the reactant is received in the many micropores. Furthermore, after used, the electrode may be cut off to expose a new electrode surface, and this new electrode surface may be coated with a material which does not impede an electrode reaction, whereby the reactant can be prevented from flowing out. Thus, the carbon micro-sensor electrode of the present invention can be repeatedly utilized.
    Type: Grant
    Filed: November 4, 1993
    Date of Patent: December 27, 1994
    Assignees: Agency of Industrial Science and Technology, Mitsubishi Pencil Kabushiki Kaisha
    Inventors: Hiroko Kaneko, Masahiro Yamada, Akira Negishi, Takamasa Kawakubo, Yoshihisa Suda
  • Patent number: 5281319
    Abstract: A carbon micro-sensor electrode is disclosed which is prepared by impregnating, adsorbing or chemically modifying a pure composite carbon wire having many micropores extending to its surface and interior with a reactant such as an enzyme, a metal complex compound, an organic compound or a metabolite; and a method for preparing this carbon micro-sensor electrode is also disclosed.The above-mentioned electrode can be used for a long period of time, since the reactant is received in the many micropores. Furthermore, after used, the electrode may be cut off to expose a new electrode surface, and this new electrode surface may be coated with a material which does not impede an electrode reaction, whereby the reactant can be prevented from flowing out. Thus, the carbon micro-sensor electrode of the present invention can be repeatedly utilized.
    Type: Grant
    Filed: June 29, 1992
    Date of Patent: January 25, 1994
    Assignee: Agency of Industrial Science and Technology
    Inventors: Hiroko Kaneko, Masahiro Yamada, Akira Negishi, Takamasa Kawakubo, Yoshihisa Suda
  • Patent number: 5218757
    Abstract: A tapered carbon microelectrode is produced by extruding an organic material or a composition composed of crystalline carbon fine powder and an organic binder into a thin rod form, carbonizing said rod by calcining to produce a pure carbon thin rod, soaking the resulting thin rod as an anode in an electrolytic solution, gradually pulling up the thin rod while electrochemically oxidizing the tip portion of the thin rod. Then a lead wire is connected with the thick portion of the thin rod followed by coating all the surface except the conically sharp tip portion.The tapered carbon electrode can be used for various electrochemical measurements and scanning tunneling microscope.
    Type: Grant
    Filed: June 25, 1991
    Date of Patent: June 15, 1993
    Assignees: Agency of Industrial Science and Technology, Mitsubishi Pencil Kabushiki Kaisha
    Inventors: Hiroko Kaneko, Masahiro Yamada, Yukifumi Shigematsu, Wataru Mizutani, Akira Negishi, Takamasa Kawakubo, Yoshihisa Suda
  • Patent number: 5171492
    Abstract: An inplant material for a living body hard tissue which is constructed by forming a core of a carbon material having a smooth and high hardness surface, an excellent mechanical strength against bending and compressing strengths, and non-impregnable to blood, lymph or the like and further forming a porous layer having a thickness of 100 microns or larger, preferably 100 microns or large on the surface of the core. This porous structure of the implant material is very important to smoothly and rigidly bond the material to a living body and is devised to produce the state that a collagen fiber newly produced in the boundary between the living body and the implant material is intruded into the porous tissue of the surface of the implant material and mutually interchanged, and a process for producing the same. Thus, the implant material has a smooth and high hardness surface, an excellent mechanical strength against bending and compressing strengths, and being non-impregnable to blood, lymph or the like.
    Type: Grant
    Filed: March 7, 1991
    Date of Patent: December 15, 1992
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Takamasa Kawakubo, Sugiro Ohtani
  • Patent number: 5096519
    Abstract: A process for preparation of a carbon fiber composite reinforced carbonaceous material characterized in that using carbon fibers or the raw material fibers of the carbon fibers as the base material, the surfaces of said base material fibers even to the surface of the single fiber are uniformly and completely coated with dormant mesophase pitch and/or isotropic pitch, and after said base material has been molded, the resulting product is subjected to carbonization treatment or graphitization treatment.
    Type: Grant
    Filed: February 22, 1990
    Date of Patent: March 17, 1992
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Takamasa Kawakubo, Etsuro Oota
  • Patent number: 4950443
    Abstract: A process for producing a carbon product having coarse and dense structures by carbonizing moldings of a mixture of one or more types of organic polymer substance, asphalt pitches, dry distilled pitches to obtain a dense structure carbon by carbonizing in an inert gas atmosphere or with a mixture of fine particle graphite powder as required, and porous organic polymer produced in point contact between the particles by solubilizing the surface layers of the organic polymer particles to obtain coarse structure carbon by sintering in particle state by carbonizing in an inert gas atmosphere, in an inert gas atmosphere after solidification to integrally mold organic liquid composition remaining high carbon residue in a composite composition, and carbonizing the composite composition in an inert gas atmosphere.
    Type: Grant
    Filed: May 9, 1989
    Date of Patent: August 21, 1990
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Takamasa Kawakubo, Mitsuru Yoshida, Yoshihisa Suda
  • Patent number: 4916292
    Abstract: A coiled resistance heating element of carbonaceous or graphite material is disclosed. A simplified process which includes carbonization or graphitization of a coiled strand of an organic material is also disclosed.
    Type: Grant
    Filed: April 14, 1988
    Date of Patent: April 10, 1990
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Takamasa Kawakubo, Mitsuru Yoshida, Yoshihisa Suda
  • Patent number: 4894215
    Abstract: Porous materials of carbon can be manufactured by introducing particles of organic polymer in a vessel of an arbitrary shape, dissolving a particle surface layer to produce point bondings between the particles, thereby producing porous materials of organic polymer, then insolubilizng or infusibilizing it, and further calcining the particles in inert gas atmosphere, thereby obtaining the porous materials of carbon fundamentally as sintered particle materials. Thus, this process permits, essentially without difficult means of managing complicated steps such as impregnating or extracting, facilitated manufacture of porous materials of carbon having a large quantity of continuous pores with ready adjustments of porosity and diameters of the pores and high strength.
    Type: Grant
    Filed: January 7, 1988
    Date of Patent: January 16, 1990
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Takamasa Kawakubo, Mitsuru Yoshida, Yoshihisa Suda
  • Patent number: 4882102
    Abstract: An improved process for producing hard carbonaceous sheets, which comprises uniformly dispersing as a viscous binder in fine carbon powder a mixture of relatively readily polymerizable thermosetting resins such as monomers, prepolymers or low polymers exhibiting high residual carbon yield after calcining; applying mechanical energy to the resultant mixture to induce mechanochemical phenomenon to produce molding paste composition in which said binder is uniformly rigidly bonded physicochemically to the surfaces of the primary particles of the fine powder, molding the composition by a fluid rolling method or a coating method in a film or sheet shape; infusibilizing the resultant molding; and calcining the resultant molding in an inert gas atmosphere. Thus, the hard carbonaceous sheets thus produced have small porosity, high mechanical strength, high elastic modulus, isotropy and uniform thickness of several microns to several mm using widely available and inexpensive manufacturing processes.
    Type: Grant
    Filed: November 2, 1987
    Date of Patent: November 21, 1989
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Takamasa Kawakubo, Mitsuru Yoshida, Yoshihisa Suda
  • Patent number: 4882103
    Abstract: A process for producing a carbon product having coarse and dense portions, the process including producing an integral porous carbon having high strength and uniform porosity distribution with dense structure carbon moldings. The carbon moldings are produced by calcining in an inert gas atmosphere a composite of (a) a green molding, a precarbonized material or a carbide and (b) chlorinated vinyl chloride resin particles, the chlorinated vinyl chloride resin producing, when carbonized in an inert gas atmosphere, a coarse structure. Dense carbon is formed by carbonizing the green molding, precarbonized material or carbide. Thus, the carbon product has coarse and dense portions.
    Type: Grant
    Filed: November 9, 1987
    Date of Patent: November 21, 1989
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Takamasa Kawakubo, Mitsuru Yoshida, Yoshihisa Suda
  • Patent number: 4863649
    Abstract: A process for producing a carbon heat generator is disclosed including the steps of uniformly dispersing one or more types of metal compounds capable of forming a vitreous film upon oxidation in a moldable composition, molding the resultant dispersed composition, precarbonizing the molded composition, and then carbonizing the composition in a nonoxidative atmosphere to form a carbon heat generator having an oxidation preventive glass film. The oxidation of the metal compound exposed on the surface of the molded composition by the use of an oxidative atmosphere forms a vitreous film which prevents oxygen from diffusing in the interior thereof. The film so produced can form a new glass film on a damaged portion by a self-recovery effect if a pinhole or a crack occurs in the glass film. Thus, the process does not cause external appearance and weight differences before and after heat generating.
    Type: Grant
    Filed: January 29, 1988
    Date of Patent: September 5, 1989
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Takamasa Kawakubo, Takao Koyama
  • Patent number: 4412675
    Abstract: A carbon spring composed substantially of carbonaceous carbon or graphite carbon is prepared by shaping an organic linear material to a coiled spring and thereafter heating it to carbonize.
    Type: Grant
    Filed: July 27, 1981
    Date of Patent: November 1, 1983
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventor: Takamasa Kawakubo
  • Patent number: 4374225
    Abstract: A method of fabricating an eraser which contains a main basic material of low crystallizable polyolefin thermoplastic elastomer and normal synthetic rubbers having no hard segment for performing a crosslinking effect, namely, any one or more of chlorinated polyethylene, ethylene-propylene terpolymer, ethylene ethyl acrylate, ethylene-vinyl acetate copolymer, atactic polypropylene, styrene-butadiene rubber, nitrile rubber and the like. The thermoplastic elastomer exhibits similar properties to vulcanized rubber without particular vulcanizing operation and crosslinking reaction. In case that less than 40 parts by weight of the elastomer is contained in the eraser, the composition does not form an eraser, while in case that higher than 100 parts by weight of the elastomer is contained in the eraser, the composition incorporates excessive rubber-like properties.
    Type: Grant
    Filed: October 10, 1980
    Date of Patent: February 15, 1983
    Assignee: Mitsubishi Pencil Co., Ltd.
    Inventors: Takamasa Kawakubo, Kiyosi Hirasawa