Patents Assigned to Tokai Carbon Co., Ltd.
  • Patent number: 5162421
    Abstract: A rubber composition comprising 100 parts by weight of a rubber component and compounded therewith 30 to 100 parts by weight of a carbon black of the category of hard carbon blacks having a nitrogen adsorption specific surface area (N.sub.2 SA) of 58 to 139 m.sup.2 /g, a DBP absorption number of 90 to 150 ml/100 g and having such selective characteristics that the intraaggregate void size, D.sub.p (nm), as measured by mercury porosimetry is equal to or higher than a value calculated by the relational formula [-0.22.times.(N.sub.2 SA)+60.8].
    Type: Grant
    Filed: April 15, 1991
    Date of Patent: November 10, 1992
    Assignee: Tokai Carbon Co., Ltd.
    Inventors: Hitoshi Ue, Yasuharu Yoshii, Shinji Misono
  • Patent number: 5143746
    Abstract: A process for producing a magnetite-coated electrode which comprises kneading an iron oxide powder, water and an organic binder under pressure sufficient to prepare a molded article, baking the molded article in a gas atmosphere mainly composed of a member selected from the group consisting of carbon dioxide and steam to prepare a magnetite sinter having an Fe to 0 ratio of 3:3.7 to 4.0, pulverizing the sinter to prepare a powder, and subjecting a metallic substrate to plasma spray coating, plasma jet spray coating, explosive spray coating and water plasma spray coating by making use of the powder as the spray coating source in a neutral gas atmosphere to form a magnetite coating on the surface of the metallic substrate.
    Type: Grant
    Filed: February 4, 1991
    Date of Patent: September 1, 1992
    Assignee: Tokai Carbon Co., Ltd.
    Inventors: Hideo Inoue, Setsuo Yoshimoto, Sakae Ikegami
  • Patent number: 5120354
    Abstract: A method of disposing of a fiber reinforced aluminum alloy composite, which comprises putting an aluminum alloy composite reinforced with inorganic short fibers into a molten steel in the deoxidizing process for steel production.
    Type: Grant
    Filed: May 7, 1991
    Date of Patent: June 9, 1992
    Assignee: Tokai Carbon Co., Ltd.
    Inventor: Takashi Ichiki
  • Patent number: 5105448
    Abstract: A device for counting the number of very small projections on a surface of an object, which includes a casing therein housing a probe to be scanned in contact with the surface of the object having continuously occurring very small projections, a tip end portion of the probe being projected out of a forward end of the casing; a detecting unit including an acceleration sensor; a comparator for converting electric signals emitted from the detecting unit into pulse signals; a latching device provided with a delay circuit for latching the pulse signals received and maintaining its emitted signals for a certain length of time; and a display device for counting and displaying the output signals from the latching device.
    Type: Grant
    Filed: May 11, 1990
    Date of Patent: April 14, 1992
    Assignee: Tokai Carbon Co., Ltd.
    Inventor: Tarou Kashiwabara
  • Patent number: 5100637
    Abstract: Carbon black for compounding into a tire tread rubber which has a nitrogen adsorption specific surface area (N.sub.2 SA) of 120 to 165 m.sup.2 /g and a dibutyl phthalate absorption of at least 120 ml/100 g which belong to the respective regions of hard grade of carbon black, and has such a value G defined by the following equation (1) as satisfying the following formula (2): ##EQU1## wherein [.DELTA.D.sub.st ] stands for a difference between two equivalent Stokes diameters at two points on the distribution curve of aggregates at which the absorbance is 50% of the maximum absorbance; [D.sub.st ] stands for an equivalent Stokes diameter (nm) at the maximum absorbance of the distribution curve of aggregates; [N.sub.2 SA] stands for a nitrogen adsorption specific surface area (m.sup.
    Type: Grant
    Filed: March 11, 1991
    Date of Patent: March 31, 1992
    Assignee: Tokai Carbon Co., Ltd.
    Inventor: Kiyonari Nakai
  • Patent number: 5069892
    Abstract: The present invention discloses a carbon black having an N.sub.2 SA of 75 to 105 m.sup.2 /g and a compressive DBP absorption of at least 110 ml/100 g and, at the same time, having the following selective characteristic values:true specific gravity.ltoreq.1.9080-0.0016.times.N.sub.2 SA;void diameter of particle aggregates (nm).gtoreq.62.2-0.236.times.N.sub.2 SA; andrange of aggregate size distribution [.DELTA.Dst (nm)].gtoreq.30.6+0.6118.times.Dst.
    Type: Grant
    Filed: October 26, 1990
    Date of Patent: December 3, 1991
    Assignee: Tokai Carbon Co., Ltd.
    Inventor: Kiyonari Nakai
  • Patent number: 5059408
    Abstract: There is disclosed carbon black for a tire tread which has a cetyltrimethylammonium bromide specific surface area (CTAB) of 120 to 160 M.sup.2 /g, a dibutly phthalate absorption number of compressed sample (24M4DBP) of at least 100 to 145 ml/100g, a tinting strength (Tint) of 100 to 150%, and such a value Ma defined by the following equation (1) as to satisfy the relationship expressed by the following formula (2): ##EQU1## wherein N.sub.2 SA is a nitrogen adsorption specific surface area (m.sup.2 /g), and Dst is the equivalent Stokes diameter (nm) at the maximum absorbance of the distribution curve of aggregates determined by the centrifugal classification method, and psMa.gtoreq.1.7-0.005 [CTAB]TM . . . (2).
    Type: Grant
    Filed: October 12, 1989
    Date of Patent: October 22, 1991
    Assignee: Tokai Carbon Co., Ltd.
    Inventor: Masahiko Mito
  • Patent number: 5053278
    Abstract: A granular carbonaceous heat insulator comprising a carbon black pellet the surface of which is coated with a carbon layer having a dense structure is disclosed. This heat insulator is prepared by adhering a binder solution to a carbon black pellet, heating the resulting coating to remove a solvent from the binder solution and, at the same time, to cure the binder, and baking the carbon black pellet coated with the cured binder in a non-oxidizing atmosphere to carbonize the cured binder. Alternatively, the heat insulator is prepared by subjecting a carbon black pellet having specific characteristics to wet granulation in the presence of a binder solution to crush the carbon black pellet and, at the same time, to granulate the crushed pellet, thereby preparing a granulated carbon black pellet, followed by removal of the solvent from the prepared pellet, curing of the binder and baking of the cured binder in the same manner as that described above.
    Type: Grant
    Filed: May 8, 1989
    Date of Patent: October 1, 1991
    Assignee: Tokai Carbon Co., Ltd.
    Inventors: Toshio Nakada, Fumio Takemura, Masao Ishiwata
  • Patent number: 4995999
    Abstract: Magnetic carbon black, a process for preparing the same, and a method of modifying magnetic carbon black are provided. The magnetic carbon black is prepared by process A in which when a hydrocarbon is supplied into a high temperature combustion gas stream formed by combustion of a fuel to prepare carbon black, an organic transition metal compound is supplied together with the hydrocarbon and, at the same time, an oxygen gas is supplied from the circumference of the hydrocarbon, process B in which a transition metal compound is supplied together with a hydrogen gas on the downstream side of the supply position of the hydrocarbon, and process C in which a hydrocarbon is supplied into a high temperature combustion gas stream on both the upstream side and the downstream side and a transition metal compound is supplied from a position between the supply positions of the hydrocarbon.
    Type: Grant
    Filed: May 21, 1990
    Date of Patent: February 26, 1991
    Assignee: Tokai Carbon Co., Ltd.
    Inventors: Toshio Nakada, Fumio Takemura, Yoshihito Sema, Kazuhito Kataoka
  • Patent number: 4973463
    Abstract: The present invention discloses carbon black for a tire tread having a cetyltrimethyl ammonium bromide specific surface area (CTAB) of 120 to 160 m.sup.2 /g, a dibutyl phthalate absorption number of compressed sample (24M4) of 95 to 135 ml/100 g, and a tinting strength (Tint) of 100 to 150% and exhibits an M value defined by the following formula (1) and satisfying the following formula (2): ##EQU1## wherein IA is the iodine adsorption number (mg/g), N.sub.2 SA is the nitrogen adsorption specific surface area (m.sup.2 /g), Dst is the equivalent Stokes diameter (nm) at the maximum absorbance of the distribution curve of aggregates determined by the centrifugal classification method, and .DELTA.Dst is the difference (nm) between two equivalent Stokes diameters at two points on the distribution curve of aggregates at which the absorbance is 50% of the maximum absorbance.
    Type: Grant
    Filed: April 25, 1989
    Date of Patent: November 27, 1990
    Assignee: Tokai Carbon Co., Ltd.
    Inventor: Kiyonari Nakai
  • Patent number: 4929472
    Abstract: Disclosed are surface-coated SiC whiskers, proceses for preparing the same, a ceramic reinforced with the same, and a process for preparing said reinforced ceramic. The surface-coated SiC whiskers are SiC whiskers (I) having a surface coated with a thin carbonaceous layer having a thickness of 7 to 100 .ANG., or SiC whiskers (II) having a surface coated with an Si.sub.3 N.sub.4 layer. The SiC whiskers (I) can be prepared by dispersing SiC whiskers in a homogeneous solution of a thermosetting resin in an organic solvent, separating the whiskers by filtration and drying it, curing the thermosetting resin, and firing the cured thermosetting resin in a non-oxidizing atmoshpere at 800.degree. to 1,600.degree. C. The SiC whiskers (II) can be prepared by dispersing SiC whiskers in a solution of an organosilicon polymer in an organic solvent, separating the whiskers by filtration and drying it, heating the whiskers coated with the organosilicon polymer in a nitriding atmoshpere at 1,200.degree. to 1,600.degree. C.
    Type: Grant
    Filed: May 31, 1988
    Date of Patent: May 29, 1990
    Assignee: Tokai Carbon Co., Ltd.
    Inventors: Kanji Sugihara, Motohiro Yamamoto, Tohru Kida, Minoru Fukazawa
  • Patent number: 4900465
    Abstract: Magnetic carbon black, a process for preparing the same, and a method of modifying magnetic carbon black are provided. The magnetic carbon black is prepared by process A in which when a hydrocarbon is supplied into a high temperature combustion gas stream formed by combustion of a fuel to prepare carbon black, an organic transition metal compound is supplied together with the hydrocarbon and, at the same time, an oxygen gas is supplied from the circumference of the hydrocarbon, process B in which a transition metal compound is supplied together with a hydrogen gas on the downstream side of the supply position of the hydrocarbon, and process C in which a hydrocarbon is supplied into a high temperature combustion gas stream on both the upstream side and the downstream side and a transition metal compound is supplied from a position between the supply positions of the hydrocarbon.
    Type: Grant
    Filed: February 10, 1988
    Date of Patent: February 13, 1990
    Assignee: Tokai Carbon Co., Ltd.
    Inventors: Toshio Nakada, Fumio Takemura, Yoshihito Sema, Kazuhito Kataoka
  • Patent number: 4888215
    Abstract: A granular carbonaceous heat insulator comprising a carbon black pellet the surface of which is coated with a carbon layer having a dense structure is disclosed. This heat insulator is prepared by adhering a binder solution to a carbon black pellet, heating the resulting coating to remove a solvent from the binder solution and, at the same time, to cure the binder, and baking the carbon black pellet coated with the cured binder in a non-oxidizing atmosphere to carbonize the cured binder. Alternatively, the heat insulator is prepared by subjecting a carbon black pellet having specific characteristics to wet granulation in the presence of a binder solution to crush the carbon black pellet and, at the same time, to granulate the crushed pellet, thereby preparing a granulated carbon black pellet, followed by removal of the solvent from the prepared pellet, curing of the binder and baking of the cured binder in the same manner as that described above.
    Type: Grant
    Filed: December 17, 1987
    Date of Patent: December 19, 1989
    Assignee: Tokai Carbon Co., Ltd.
    Inventors: Toshio Nakada, Fumio Takemura, Masao Ishiwata
  • Patent number: 4786677
    Abstract: A rubber composition comprising 35 to 100 parts by weight of a carbon black per 100 parts by weight of a rubber component, the carbon black having a nitrogen adsorption specific surface area (N.sub.2 SA) within a range of 70 to 185 m.sup.2 /g and an aggregate characteristic which shows a first and a second modal diameters in the aggregate equivalent Stokes diameter distribution and has a difference between the two modal diameters L (nm) to be calculated from the following equation (1) which satisfies the following formula (2):L=Dst.sub.2 -Dst.sub.1 (1)20.ltoreq.L.ltoreq.110-0.3 (N.sub.2 SA) (2)wherein Dst.sub.1 and Dst.sub.2 respectively denote the first modal diameter (nm) and the second modal diameter (nm) in the aggregate equivalent Stokes diameter distribution detetermined by a centrifugal classification method.
    Type: Grant
    Filed: December 2, 1987
    Date of Patent: November 22, 1988
    Assignee: The Tokai Carbon Co., Ltd.
    Inventors: Kiyonari Nakai, Masahiko Mito
  • Patent number: 4784695
    Abstract: A carbon black for blending in rubber is disclosed, which has a BET specific surface area (N.sub.2 SA) within a range of 65 to 84 m.sup.2 /g, an a value to be obtained according to the following calculation formula, of at least 270 and a ratio of the BET specific surface area (N.sub.2 SA) to the iodine adsorption number (IA), N.sub.2 SA/AI, within a range of 1.10 to 1.35:a=(24M4DBP).sup.2 .times.(Blackness/IA ).sup.2 .times.(Dst).sup.2 .times.10.sup.
    Type: Grant
    Filed: March 4, 1988
    Date of Patent: November 15, 1988
    Assignee: Tokai Carbon Co., Ltd.
    Inventors: Masahiko Mito, Kiyonari Nakai
  • Patent number: 4690811
    Abstract: The present invention provides a process for preparing silicon carbide whiskers. According to the process, carbon black having the following properties (a) to (c) is blended, as a carbonaceous material, with a silicon source material, and the resulting mixture is heated in a non-oxidizing atmosphere at 1,300.degree. to 1,800.degree. C.(a) Nitrogen adsorption specific surface area: 150 to 500 m.sup.2 /g(b) Dibutyl phthalate absorption: 120 to 200 ml/100 g.(c) Tint strength (%): equal to or below a value calculated according to the following formula:0.3496.times.(nitrogen adsorption specific surface area)-0.2143.times.(dibutyl phthalate absorption)+101.
    Type: Grant
    Filed: November 18, 1985
    Date of Patent: September 1, 1987
    Assignee: Tokai Carbon Co., Ltd.
    Inventors: Tohru Kida, Motohiro Yamamoto
  • Patent number: 4632794
    Abstract: In a process for manufacturing a whisker preform for a composite material, a dispersion of a whisker in water or an organic solvent is passed through a sieve and is filtered, and a residual wet whisker cake is dried, with or without prior compression, to produce a cake having a desired density based upon the relationship between the weight of the whisker in the dispersion and the volume of the residual whisker cake after filtration.
    Type: Grant
    Filed: December 8, 1983
    Date of Patent: December 30, 1986
    Assignee: Tokai Carbon Co., Ltd.
    Inventors: Shigeto Mori, Minoru Fukazawa
  • Patent number: 4548774
    Abstract: The invention provides a method for preparing a SiC whisker-reinforced composite material. A matrix material such as a metal, an alloy or a plastic is introduced into a fibrous base consisting of a SiC whisker sponge-like cake. The resultant structure is compressed into a desired shape as needed. The fibrous base is prepared by heating a mixture of silica gel or ashed rice hulls with a furnace carbon black and an additional amount of NaCl as a space forming agent for forming spaces conducive to whisker growth.
    Type: Grant
    Filed: July 19, 1983
    Date of Patent: October 22, 1985
    Assignee: Tokai Carbon Co., Ltd.
    Inventors: Masaru Akiyama, Jotaro Yamada, Masaya Takahata
  • Patent number: 4500504
    Abstract: The process according to the present invention involves mixing 100 parts by weight of a silica gel, containing 6.0 to 25.0% by weight with respect to a silicon of a water-soluble compound of at least one metal selected from the group consisting of iron, nickel and cobalt, with 110 to 400 parts by weight of furnace carbon black having a structure indicated by a DBP absorption number of 50 ml/100 g or higher, and then reacting the mixture under a non-oxidative atmosphere at a temperature of 1,300.degree. to 1,700.degree. C. to produce silicon carbide whiskers.
    Type: Grant
    Filed: January 25, 1983
    Date of Patent: February 19, 1985
    Assignee: Tokai Carbon Co., Ltd.
    Inventor: Akira Yamamoto
  • Patent number: 4500672
    Abstract: According to this invention, a rubber composition is provided, which comprises 100 parts by weight of a rubber component and 25 to 250 parts by weight of carbon black, which carbon black falls within the property range of an electron-microscopic average particle diameter (dn) of above 31 millimicron, an iodine adsorption number of 35 to 60 mg/g and a dibutyl phthalate absorption number (DBP) of 90 to 150 ml/100 g and further has a selected property such that the Dst mode diameter (m.mu.) is below the value (m.mu.) obtained from the following equation:Dst=2.65.times.dn+0.64.times.DBP-27.
    Type: Grant
    Filed: November 2, 1983
    Date of Patent: February 19, 1985
    Assignee: Tokai Carbon Co., Ltd.
    Inventors: Hiroaki Suzuki, Shinji Misono