Patents Assigned to Nihon Cement Co. Ltd.
  • Patent number: 5834106
    Abstract: A ceramic substrate for a hard disc, a thin film chip capacitor, and hybrid ICs, and a suction carrier for a substrate is constituted by using a titanium oxide or aluminum oxide substrate having an extremely small number of pores having diameters of 3 .mu.m or more on the substrate surface.The substrate is produced by baking highly purified titanium oxide fine powder or highly purified aluminum oxide fine powder in the air, an inert atmosphere or a reducing atmosphere (at 1,100.degree. C. to 1,300.degree. C. for the former and at 1,200.degree. to 1,400.degree. C. for the latter) and HIP treating the baked material.
    Type: Grant
    Filed: November 28, 1994
    Date of Patent: November 10, 1998
    Assignee: Nihon Cement Co., Ltd.
    Inventors: Hideto Kamiaka, Yukio Kishi
  • Patent number: 5770916
    Abstract: A laminated piezoelectric element has a surface electrode formed on a surface of the element and having an area falling within the range from 0.002 mm.sup.2 to 0.2 mm.sup.2, and a first region excluding the surface electrode on the surface on which the surface electrode is formed, and having a level difference (surface roughness) which is less than or equal to 20 .mu.m.
    Type: Grant
    Filed: January 24, 1996
    Date of Patent: June 23, 1998
    Assignees: Canon Kabushiki Kaisha, Nihon Cement Co., Ltd.
    Inventors: Toru Ezaki, Takahiro Yamakawa, Yutaka Maruyama, Nobuyuki Kojima
  • Patent number: 5731251
    Abstract: A titania ceramic body consists of a surface thereof not exceeding 35 pores per square millimeter. The titania ceramic body is made by preparing a titania powder having a purity of at least 99.8 wt % titania and an average particle diameter of 0.5 .mu.m, compacting the powder, sintering a compact at a temperature in the range for 1000.degree. to 1300.degree. C. in air or in a non-air surrounding gas under ordinary pressure to produce a sintered body, hot isostatic pressing treating the sintered body in argon at a temperature of from 800.degree. C. to below temperature carried out in above sintering step under pressure of at least 500 kg/cm2, and then grinding and polishing the hot isostatic pressing treated body.
    Type: Grant
    Filed: November 27, 1996
    Date of Patent: March 24, 1998
    Assignee: Nihon Cement Co., Ltd.
    Inventor: Yukio Kishi
  • Patent number: 5700414
    Abstract: The present invention relates to a heat-insulating panel formed of curly contracted pieces of tapes, for example thermally contracted pieces of magnetic tapes, and a method of manufacturing such a panel. In particular, the present invention concerns a heat-insulating panel which also serves as a concrete form. The heat-insulating panel has excellent strength characteristics such, as bending strength and bending rigidity, and dimensional stability, as well as characteristics of sound absorption, heat-insulation, electrostatic shielding and electromagnetic wave absorption, and is usable for a concrete form when placing concrete during the construction of a building formed of reinforced concrete or steelframe reinforced concrete. The present invention relates also to a method of manufacturing the panel.
    Type: Grant
    Filed: November 3, 1995
    Date of Patent: December 23, 1997
    Assignees: Nihon Cement Co. Ltd., Fuji Kasei Kogyo Kabushiki Kaisha
    Inventors: Yuukou Ishikawa, Noboru Nishimoto, Michio Ootani, Tooru Tanibe, Kazushige Suzuki, Kanesuke Kasahara
  • Patent number: 5669127
    Abstract: In an electro-mechanical energy conversion device which is disclosed, green sheets on which whole surface electrodes for grounding have been printed and green sheets on which 2-divided electrodes have been printed are laminated. The green sheets having the 0.degree. phase and 90.degree. phase on which the 2-divided electrodes have been printed are laminated through the printed sheet on which the whole surface electrode for grounding. After the laminate body was sintered and integrated, it is polarized in a manner such that the polarizing directions in the thickness direction of each layer are opposite between the two divided electrodes which form one pair by using the whole surface electrodes for grounding and the 2-divided electrodes which were printed, thereby constructing the conversion device for the laminated type vibration driven motor.
    Type: Grant
    Filed: November 5, 1996
    Date of Patent: September 23, 1997
    Assignees: Canon Kabushiki Kaisha, Nihon Cement Co, Ltd.
    Inventors: Shigeru Takahashi, Sadakatsu Okura, Toshikatsu Nomura
  • Patent number: 5665663
    Abstract: An oxide ceramic sintered body of a single component having a purity of at least 99% by weight of titania and a surface with a plurality of pores therein not exceeding 100 pores per square millimeter. The sintered ceramic body is made by preparing a raw titania powder having a purity of at least 99% titania by weight and an average maximum particle diameter of 1 .mu.m, compacting the titania powder to produce a compact, sintering the compact at a temperature in the range of about 1000.degree. C. to about 1300.degree. under ordinary pressure in air, or an inert or reducing atmosphere. The sintered ceramic body may be hot isostatic pressure treated below the sintering temperature in an inert atmosphere under a pressure of at least 500 kg/cm.sup.2 to further reduce the number of pores in the surface.
    Type: Grant
    Filed: November 6, 1995
    Date of Patent: September 9, 1997
    Assignee: Nihon Cement Co., Ltd.
    Inventor: Yukio Kishi
  • Patent number: 5650366
    Abstract: A ceramic mirror having a surface flatness of no more than 1 .mu.m and/or a centerline average height of no more than 1 nm as measured by the laser interference method, is made from a titanium oxide powder having an average particle diameter of 0.5 .mu.m and a minimum purity of 99.8% by weight. The mirror also has a maximum amount of irregular reflection of incident light not exceeding 5% when the angle of projection is between 0.degree. and 90.degree. as measured by a colorimeter and is made by the process including forming a titanium oxide powder having a maximum average particle diameter of 0.5 .mu.m and a minimum purity of 99.8 wt. %, compacting the titanium oxide powder by cold isostatic pressing to produce a compact, sintering the compact of titanium oxide powder in air at a temperature of 1000.degree. C.-1300.degree. C. to produce a ceramic body, hot isostatic pressing the ceramic body after the sintering in an inert atmosphere at 800.degree. C.-1500.degree. C. under a minimum pressure of 500 kg/cm.
    Type: Grant
    Filed: January 25, 1996
    Date of Patent: July 22, 1997
    Assignee: Nihon Cement Co., Ltd.
    Inventor: Yukio Kishi
  • Patent number: 5631075
    Abstract: A heat-insulating panel serving also as a concrete frame excellent in bending strength characteristics and dimensional stability and a method of manufacturing the panel. Cut or shredded pieces having lengths of 20 mm or less of magnetic tapes are heated to 100.degree. to 200.degree. C., thus forming contracted pieces of magnetic tapes in curled shapes. The curled contracted pieces of magnetic tapes in an amount of 100 parts by weight are mixed with 10 to 50 parts by weight of a thermosetting resin as a binder, and are compression-molded under a pressure ranging from 2 to 20 kgf/cm.sup.2 at a temperature from 100.degree. to 200.degree. C.
    Type: Grant
    Filed: October 31, 1994
    Date of Patent: May 20, 1997
    Assignees: Nihon Cement Co., Ltd., Fuji Kasei Kogyo Kabushiki Kaisha
    Inventors: Yuukou Ishikawa, Noboru Nishimoto, Michio Ootani, Tooru Tanibe, Kazushige Suzuki, Kanesuke Kasahara
  • Patent number: 5547505
    Abstract: Compositions for low heat cements developed especially for massive concrete works and which exhibit a compressive strength/heat of hydration ratio of at least 7.0 at the age of 13 weeks. One of two inventions provides a powder prepared by mixing CaO, SiO.sub.2, and Al.sub.2 O.sub.3 materials, melting the mixture, quenching the melt, and grinding the quenched matter, the powder being composed mainly of amorphous substances and chemically having a CaO/SiO.sub.2 (molar ratio) of 0.8-1.5 and an Al.sub.2 O.sub.3 content of no more than 10 wt. %. The other invention provides a mixed powder comprising no less than 70 wt. % of a powder and no more than 30 wt. % of an addition (portland cement or the like), the powder being the same as that of the first invention in both predominance of amorphous substances and CaO/SiO.sub.2 (molar ratio) excepting the Al.sub.2 O.sub.3 content which is less than 12 wt. % in the second invention.
    Type: Grant
    Filed: May 25, 1995
    Date of Patent: August 20, 1996
    Assignee: Nihon Cement Co., Ltd.
    Inventors: Kazuya Nakatsu, Takaharu Goto, Toru Higaki, Hideki Endo, Satoru Hirose, Yukinori Yamazaki
  • Patent number: 5492872
    Abstract: A ceramic mirror having a maximum surface flatness of 1 .mu.m and/or a maximum centerline average height of 1 nm as measured by the laser interference method, and a method of manufacturing a ceramic mirror by compacting a titanium oxide powder having an average particle diameter no greater than 1 .mu.m and a purity of at least 99% and then sintering the compact in an ordinary, inert, vacuum, or reducing atmosphere at a temperature between 1000.degree. and 1300.degree. C. The sintering pressure may be a minimum of 50 kg/cm.sup.2. After sintering, the product may be further treated by hot isostatic pressing (HIP) in an Ar atmosphere at 1000.degree. C. and a pressure of 1800 kg/cm.sup.2. The sintered bodies are then surface ground or lapped to produce ceramic mirrors having the above characteristics for use in laser and X-ray apparatuses, cameras, and other precision optical instruments.
    Type: Grant
    Filed: August 1, 1994
    Date of Patent: February 20, 1996
    Assignee: Nihon Cement Co., Ltd.
    Inventor: Yukio Kishi
  • Patent number: 5302329
    Abstract: The present invention is a process for producing .beta.-sialon based sintered bodies having a fracture toughness (K.sub.IC) of at least 6.5 MPam.sup.1/2.The process comprises preparing a feed that consists of 0.5-20 wt % of a sintering aid (e.g. MgO) with an average particle size of no more than 5.0 .mu.m, 3-40 wt % of an additive (e.g. SiC) with an average particle size of no more than 5.0 .mu.m, with the remainder being a .beta.-sialon powder having an average particle size of no more than 2.0 .mu.m, wet mixing the individual feeds to form a slurry, drying the slurry and sintering the dried slurry.
    Type: Grant
    Filed: October 21, 1991
    Date of Patent: April 12, 1994
    Assignee: Nihon Cement Co., Ltd.
    Inventors: Tatsuya Shiogai, Yoshitsugu Nishi, Chitake Yamagishi
  • Patent number: 5209613
    Abstract: A diamond tool which generates little vibrations, can be used in high temperature environments and can be produced with excellent yield has at least a shank portion (2) in contact with a diamond chip (1) and formed from a reaction-sintered silicon carbide material having a thermal expansion coefficient close to that of the diamond chip by using a diamond granule, and a method for producing the diamond tool which comprises contacting a diamond chip with an ingredient layer mixed with a diamond granule and a carbonaceous source, placing a metallic silicon powder on the surface of the layer, and then reaction-sintering it in vacuum or in a non-oxidizing atmosphere by heating, thereby forming a reaction-sintered silicon carbide material having a coefficient of thermal expansion close to that of a diamond chip, at least, in the shank portion at which a diamond chip is in contact.
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: May 11, 1993
    Assignees: Nihon Cement Co. Ltd., Nihon Ceratec Co. Ltd.
    Inventor: Noriyuki Nishio
  • Patent number: 5181961
    Abstract: A low shrinkage cement composition containing at least one compound having the formula:ROHwherein R is an alkyl group having about 4 to 6 carbon atoms or a cycloalkyl group having about 5 to 6 carbon atoms.
    Type: Grant
    Filed: August 29, 1991
    Date of Patent: January 26, 1993
    Assignees: Nihon Cement Co., Ltd., Sanyo Chemical Industries, Ltd.
    Inventors: Yasuhide Umaki, Rokuro Tomita, Fumiaki Hondo, Shigeru Okada
  • Patent number: 4984675
    Abstract: A pair of sorting gates are fixed respectively to a pair of moving shafts that are disposed facing with each other so as to be able to move horizontally along the same straight line, and when a sorting gate is moved horizontally from a retracted position to a forwardly moved position interrupting the moving path of a sorting pin accompanying a forward motion of one of the moving shafts to which is fixed the sorting gate, the moving shaft at the forwardly moved position functions as a stopper member for the other moving shaft that is at the retracted position, and obstructs the forward motion of the moving shaft that is at the retracted position.
    Type: Grant
    Filed: September 27, 1989
    Date of Patent: January 15, 1991
    Assignee: Nihon Cement Co., Ltd.
    Inventors: Keiji Yamabe, Masao Yoshinaga
  • Patent number: 4941561
    Abstract: In an article sorting device equipped with a pair of endless chains that are arranged facing with each other, and are constructed so as to be driven to rotate in the same direction; a plurality of article conveying boards that are mounted on the endless chains in a condition slidable in a direction perpendicular to the direction in which the pair of endless chains are driven, with sorting pins attached to the bottom surface of each of the boards; and a pair of sorting members that enter the moving paths of the sorting pins, and guide the subsequent sorting pins in predetermined directions; the article sorting device characterized in that a downward slanted part is provided at each end part that traverses the moving path of the sorting pin of the sorting members, the upper edges of the slanted parts are formed in a wedge shape, and the lower end parts of the sorting pins that correspond to the slanted parts of the sorting members are formed in a conical form.
    Type: Grant
    Filed: August 28, 1989
    Date of Patent: July 17, 1990
    Assignee: Nihon Cement Co., Ltd.
    Inventors: Keiji Yamabe, Masao Yoshinaga
  • Patent number: 4895814
    Abstract: An alumina silica sintered ceramic that is produced by the normal sintering method and which has bending strength of at least 300 MPa at room temperature and at least 400 MPa at an elevated temperature, for example, 1,300.degree. C. is disclosed.This sintered ceramic is produced by a process comprising the following steps: providing a chiefly amorphous starting powder that consists of 62-73 wt % Al.sub.2 O.sub.3 and correspondingly 38-27 wt % SiO.sub.2 ; calcining this starting powder to make a calcined product that is chiefly composed of a crystalline phase and which contains oxides of an alkali metal and an alkaline earth metal in a total amount of no more than 1,500 ppm; pressing the ground particles of the calcined product into a compact; and sintering the compact at 1,500.degree.-1,750.degree. C. and at atmospheric pressure.
    Type: Grant
    Filed: June 24, 1987
    Date of Patent: January 23, 1990
    Assignees: Agency of Industrial Science and Technology, Mino Yogyo Co., Ltd., Nihon Cement Co., Ltd., Hokko Chemical Industry Co., Ltd.
    Inventors: Shuzo Kanzaki, Hideyo Tabata, Osami Abe, Ohta Shigetoshi, Yamagishi Chitake, Mitachi Senshu
  • Patent number: 4886533
    Abstract: A gas filter that has a simple structure and maintain the sealing effect of sealing members even at a high temperature is disclosed. The gas filter comprises a case with a gas inlet and a gas outlet, a ceramic filter placed in the case, sealing members for sealing gaps between the case and the filter and also for directing gas entering from the gas inlet so as not to bypass the filter before exiting, and an elastic member placed in the case for pressing the sealing members to ensure unfailing sealing.
    Type: Grant
    Filed: September 29, 1988
    Date of Patent: December 12, 1989
    Assignee: Nihon Cement Co., Ltd.
    Inventors: Kimiaki Sakashita, Masaaki Kouno, Hideo Tsukazaki
  • Patent number: 4818511
    Abstract: A process for producing non-oxide compounds such as silicon nitride and silicon carbide by using a multi-stage apparatus constructed of a raw material drier section, a reactor section including a multiplicity of reaction vessels, and a non-oxidizing gas feeder section, is disclosed. The sections are arranged serially in the vertical direction. Raw materials are reacted with one another while fluidizing or bubbling by a hot non-oxidizing gas (argon or nitrogen) occurs in the raw material drier section and reaction vessels.
    Type: Grant
    Filed: July 22, 1987
    Date of Patent: April 4, 1989
    Assignee: Nihon Cement Co., Ltd.
    Inventors: Yoshitsuga Nishi, Kenji Kawasaki, Mutuo Hayashi, Chitake Yamagishi
  • Patent number: 4617059
    Abstract: A demolition agent for brittle materials which is prepared by pulverizing a quick lime clinker including 0.5 to 10.0% by weight of phosphorus components in terms of P.sub.2 O.sub.5.
    Type: Grant
    Filed: April 11, 1985
    Date of Patent: October 14, 1986
    Assignee: Nihon Cement Co., Ltd.
    Inventor: Yukinori Yamazaki
  • Patent number: 4547223
    Abstract: This invention relates to a cement-shrinkage-reducing agent and a cement composition comprising a compound of the general formula RO(AO).sub.n H (in which R represents a C.sub.1-7 alkyl or C.sub.5-6 cycloalkyl radical, A represents one or more C.sub.2-3 alkylene radicals, and n has a value of 1-10) for use in making cement mortar and concrete.
    Type: Grant
    Filed: May 4, 1982
    Date of Patent: October 15, 1985
    Assignee: Nihon Cement Co., Ltd.
    Inventors: Takaharu Goto, Takeshi Sato, Kouzou Sakai, Motohiko Ii