Patents by Inventor Yasuo Nishikawa

Yasuo Nishikawa 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: 5164259
    Abstract: A magnetic recording medium comprising a non-magnetic support having a magnetic layer provided thereon, wherein a higher fatty acid hydroxylaluminum salt represented by formula (I) is provided in or on the magnetic layer:(R.sup.1 COO).sub.n Al(OH).sub.3-nwherein R.sup.1 is a hydrocarbon group having from 10 to 26, and n is an integer of 1 or 2. The magnetic recording medium has a low coefficient of friction and good running durability even when used or stored under high-temperature and high humidity conditions.
    Type: Grant
    Filed: April 9, 1991
    Date of Patent: November 17, 1992
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Toshio Ishida, Yasuo Nishikawa, Akira Ushimaru
  • Patent number: 5145738
    Abstract: A magnetic recording medium comprising a non-magnetic support having thereon a magnetic layer comprising ferromagnetic metal powder and a binder, the magnetic layer further comprising carbon black having an average particle diameter of 250 m.mu. or more in an amount of from 1 to 10 parts by weight per 100 parts by weight of the ferromagnetic metal powder, and an ester of tridecyl alcohol with stearic acid and/or an ester of tridecyl alcohol with palmitic acid in an amount of from 5 to 20 parts by weight per 100 parts by weight of the ferromagnetic metal powder.
    Type: Grant
    Filed: March 31, 1989
    Date of Patent: September 8, 1992
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Mikihiko Kato, Yasushi Endo, Toshio Kawamata, Yasuo Nishikawa
  • Patent number: 5126215
    Abstract: A magnetic recording medium comprising a nonmagnetic support having formed thereon a magnetic layer containing ferromagnetic particles dispersed in a binder, wherein the surface of the magnetic layer has pores of (a) at most 50 .ANG. in the average value of pore inlet diameters measured by a nitrogen gas adsorption method and (b) at least 25 .ANG. in the half value width of the frequency distribution curve of the pore inlet diameters.
    Type: Grant
    Filed: April 13, 1989
    Date of Patent: June 30, 1992
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masashi Aonuma, Hiroaki Araki, Hiroshi Hashimoto, Tsutomu Okita, Yasuo Nishikawa
  • Patent number: 5091249
    Abstract: A magnetic recording medium comprising a non-magnetic support having a magnetic layer thereon, wherein the surface of the magnetic layer contains (a) a first fluorinated polyether having an oxo acid group or an oxo acid salt group at one or both terminals thereof, and (b) a second fluorinated polyether having a group selected from a alkoxycarbonyl group, an acyloxy group and a hydroxyl group at one or both terminals thereof, or the polyether (a) and polyether (b) are incorporated into the magnetic layer.
    Type: Grant
    Filed: July 11, 1990
    Date of Patent: February 25, 1992
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Yasuo Nishikawa, Kunihiko Sano
  • Patent number: 5091268
    Abstract: A novel magnetic recording medium is provided comprising a non-magnetic support having provided thereon a magnetic layer comprising a ferromagnetic powder dispersed in a binder, wherein at least one fatty acid amide compound represented by formula (I), at least one fatty acid ester represented by formula (II) and at least one fatty acid ester represented by formula (III) are provided in or on the magnetic layer: ##STR1## wherein R.sup.1 represents a C.sub.13-21 straight-chain saturated hydrocarbon group; ##STR2## wherein R.sup.2 represents a C.sub.12-21 straight-chain or branched saturated or unsaturated hydrocarbon group; and R.sup.3 represents a C.sub.1-10 straight-chain or branched saturated or unsaturated hydrocarbon group; ##STR3## wherein R.sup.4 represents a C.sub.12-21 straight-chain or branched saturated or unsaturated hydrocarbon group; R.sup.5 represents a C.sub.2-3 divalent hydrocarbon group; R.sup.6 represents a C.sub.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: February 25, 1992
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Yasuo Nishikawa, Akira Kasuga, Tsutomu Okita, Masashi Aonuma
  • Patent number: 5091270
    Abstract: A magnetic recording medium is disclosed, which has a magnetic layer on a non-magnetic support, wherein at least a mixture of ester compounds shown by formula (I) obtained by the reaction of a straight chain or branched fatty acid having from 12 to 30 carbon atoms and branched alcohols having from 10 to 32 carbon atoms synthesized by oxo synthesis is retained in or on the magnetic layer: ##STR1## wherein R.sub.1 represents a straight chain or branched alkyl group having from 11 to 29 carbon atoms or a straight chain or branched alkenyl group having from 11 to 29 carbon atoms, and R.sub.2 represents a branched alkyl group having from 10 to 32 carbon atoms. The magnetic recording medium has an excellent running durability in wide ranges of temperature and humidity condition.
    Type: Grant
    Filed: July 21, 1989
    Date of Patent: February 25, 1992
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Takao Ohya, Yasuo Nishikawa, Satoru Hayakawa
  • Patent number: 5089330
    Abstract: An abrasive tape comprises a flexible substrate and an abrasive layer which is overlaid on the flexible substrate and which contains abrasive grains, a binder, and an additive. The additive contains at least one kind of a compound represented by the general formula of ##STR1## where R.sub.1 represents a monovalent hydrocarbon group having six to 30 carbon atoms, or a fluorine-substituted alkyl group having one to 17 carbon atoms, R.sub.2 represents H or a monovalent alkyl group having one to three carbon atoms, X represents either one of ##STR2## where R.sub.3 is C.sub.3 F.sub.7 and n is an integer of 1 to 30.
    Type: Grant
    Filed: January 17, 1991
    Date of Patent: February 18, 1992
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masami Sato, Masaaki Fujiyama, Yasuo Nishikawa, Takashi Iwasaki
  • Patent number: 5082714
    Abstract: The running properties and durability under a wide range of temperature and humidity conditions are improved by the presence of terminally modified polyhexafluoropropylene on a thin ferromagnetic metal film.
    Type: Grant
    Filed: October 7, 1988
    Date of Patent: January 21, 1992
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Akio Yanai, Yasuo Nishikawa
  • Patent number: 5063105
    Abstract: A magnetic recording medium comprising a nonmagnetic support having formed thereon a magnetic layer containing a ferromagnetic fine powder, a binder, and carbon black and formed on the opposite side of the nonmagnetic support to the magnetic layer-carrying side a backing layer containing a binder and carbon black, wherein (i) the Young's modulus of the magnetic layer is from 600 to 1100 kg/mm.sup.2 and the Young's modulus of the backing layer is from 200 to 400 kg/mm.sup.2, or (ii) the surface free energy of the backing layer is at least 1 dyn/cm higher than the surface free energy of the magnetic layer, the gloss of the magnetic layer is at least 150, and the gloss of the backing layer is from 2 to 7.
    Type: Grant
    Filed: January 17, 1990
    Date of Patent: November 5, 1991
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsumi Ryoke, Masatoshi Takahashi, Yasuo Nishikawa
  • Patent number: 5063119
    Abstract: A magnetic recording medium comprising a nonmagnetic support having provided thereon a magnetic layer comprising ferromagnetic particles dispersed in a binder, said magnetic layer having therein or on its surface a fluorine-containing oligomer surfactant which has a side chain having a poly(alkylene oxide) structure, a side chain terminated with a perfluoroalkyl group, and a side chain derived from an ester of acrylic or methacrylic acid with an aliphatic alcohol.
    Type: Grant
    Filed: March 7, 1990
    Date of Patent: November 5, 1991
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Toshio Ishida, Akira Ushimaru, Yasuo Nishikawa
  • Patent number: 5061564
    Abstract: A magnetic recording medium is disclosed, which comprises a non-magnetic support having provided thereon a magnetic layer mainly composed of a ferromagnetic powder and a binder resin comprising (i) a polymer having at least one polar group selected from --SO.sub.3 M.sup.1, --OSO.sub.3 M.sup.1, --COOM.sup.1, ##STR1## wherein M.sup.1 represents a hydrogen atom, Li, Na or NR.sub.4 (wherein R represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkanol group), and M.sup.2 represents a hydrogen atom, Li, Na, an alkyl group, or NR.sub.4 (wherein R has the same significance as defined above); or (ii) a compound having at least one polar group selected from --SO.sub.3 M.sup.3, --COOM.sup.3, and --PO.sub.3 (M.sup.3).sub.2 (wherein M.sup.
    Type: Grant
    Filed: July 21, 1989
    Date of Patent: October 29, 1991
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Takao Ohya, Jun Nakagawa, Satoru Hayakawa, Yasuo Nishikawa, Tsutomu Okita, Hiroshi Hashimoto
  • Patent number: 5053289
    Abstract: A magnetic recording medium comprising a nonmagnetic support having thereon a magnetic layer, wherein an ester compound obtained by condensing a saturated fatty acid having from 6 to 26 carbon atoms and an unsaturated alcohol having from 8 to 26 carbon atoms is present on or in the magnetic layer.
    Type: Grant
    Filed: March 29, 1989
    Date of Patent: October 1, 1991
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Yasuo Nishikawa, Takashi Yoneyama, Kunihiko Sano
  • Patent number: 5051318
    Abstract: A magnetic recording medium is disclosed, which comprises a non-magnetic support having thereon a magnetic layer comprising ferromagnetic particles dispersed in a binder, said magnetic layer containing an organic silicone compound modified with a branched chain saturated fatty acid, and represented by formula (I): ##STR1## wherein R, R', and R" each represents a branched chain saturated hydrocarbon group having 7 to 24 carbon atoms; m represents an integer of 1 to 100; n represents an integer of 0 to 250; m+n.ltoreq.300; and m.gtoreq.n/5.
    Type: Grant
    Filed: October 18, 1999
    Date of Patent: September 24, 1991
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Yasuo Nishikawa, Tsutomu Okita
  • Patent number: 5049448
    Abstract: A magnetic recording medium is disclosed, comprising a nonmagnetic support having thereon a magnetic layer, wherein at least one of ester compounds represented by formula (I) is present in or on the magnetic layer, ##STR1## wherein R.sub.1 represents a straight chain, saturated alkyl group having 6 to 12 carbon atoms, R.sub.2 represents a straight chain, saturated alkyl group having 4 to 10 carbon atoms, and R represents a branched or straight chain alkyl group having 4 to 22 carbon atoms.
    Type: Grant
    Filed: July 24, 1989
    Date of Patent: September 17, 1991
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Takao Ohya, Yasuo Nishikawa, Jun Nakagawa, Fusao Yamanaka, Toshio Kawamata, Tsutomu Okita, Hiroshi Hashimoto, Mikihiko Kato
  • Patent number: 5045351
    Abstract: A process for producing a magnetic recording medium which comprises a step of kneading a ferromagnetic powder with a binder in the presence of a solvent, a step of dispersing the resulting blend with the binder and/or solvent, and a step of coating the resulting magnetic coating composition on a nonmagnetic support followed by drying;Wherein said step of kneading is carried out by kneading a ferromagnetic powder having a particle size of not more than 350 .ANG. with a glycidyl compound and a binder comprising at least a vinyl chloride copolymer having an OH- terminated side chain bonded via an organic group and also having a polar group and/or a solvent; said binder, polyurethane resin, and solvent being used in a total amount of from 40 to 70 parts by weight per 100 parts by weight of said ferromagnetic powder; and wherein said step of dispersing is carried out in the presence of additional polyurethane resin having a polar group and/or solvent.
    Type: Grant
    Filed: October 18, 1989
    Date of Patent: September 3, 1991
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Tsutomu Okita, Yasuo Nishikawa, Hiroshi Hashimoto, Hideomi Watanabe
  • Patent number: 5041336
    Abstract: A magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer comprising a ferromagnetic powder dispersed in a binder,wherein said binder comprises a polymer containing a polar group selected from --SO.sub.3 M, --OSO.sub.3 M, --COOM, ##STR1## where M represents a hydrogen atom, Li, Na, K or NR.sub.4 where R represents a hydrogen atom or an alkyl group, and M' represents a hydrogen atom, Li, Na, K, an alkyl group or NR.sub.4 where R represents a hydrogen atom or an alkyl group, andsaid magnetic layer contains at least one fatty acid ester compound represented by formula (I), at least one fatty acid ester compound represented by formula (II), and at least one fatty acid having from 11 to 35 carbon atoms: ##STR2## wherein R.sup.1 represents a linear or branched chain hydrocarbon group having from 11 to 35 carbon atoms, R.sup.
    Type: Grant
    Filed: September 30, 1988
    Date of Patent: August 20, 1991
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Takao Ohya, Yasuo Nishikawa, Akihiro Matsufuji, Akira Kasuga, Kiyomi Ejiri
  • Patent number: 5030521
    Abstract: A magnetic recording medium comprises a nonmagnetic support and a magnetic recording layer containing a ferromagnetic powder which is provided on the support. The magnetic recording layer contains a binder resin having a acid residue or a salt thereof and a fatty acid ester compound having the formula (I): ##STR1## wherein R is a hydrocarbon group having 11-21 carbon atoms, R.sup.1 is hydrogen atom or a hydrocarbon group having 1-3 carbon atoms, and R.sup.2 and R.sup.3 are the same or different and each is a hydrocarbon group having 1-8 carbon atoms. The total number of carbon atoms contained in R.sup.1, R.sup.2 and R.sup.3 being not less than 3 carbon atoms. Alternatively, the fatty acid ester can be coated on the magnetic layer.
    Type: Grant
    Filed: April 20, 1988
    Date of Patent: July 9, 1991
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Yasuo Nishikawa, Takao Ohya, Hajime Miyatsuka
  • Patent number: 4937098
    Abstract: A method for manufacturing a magnetic recording medium is disclosed, comprising ferromagnetic alloy powders having an average length in the long axis of 0.3 .mu.m or less and a specific surface area (BET Method) of 45 m.sup.2 /g or more, by steps which comprise surface-treating the ferromagnetic alloy powders with at least one triazine thiol compound, dispersing the surface-treated powders in a binder, and then coating the binder containing the surface-treated powders on a nonmagnetic support, wherein the ferromagnetic alloy powders are surface-treated with a triazine thiol compound represented by formula (I) in a condition in which the moisture content of the ferromagnetic alloy powders is 0.5 wt % or less, in a system of substantially excluded moisture: ##STR1## wherein R represents R.sub.1 O--, R.sub.1 S--, R.sub.1 NH--, or R.sub.1 R.sub.2 N--R.sub.1 --, R.sub.1 and R.sub.
    Type: Grant
    Filed: April 20, 1989
    Date of Patent: June 26, 1990
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Yasuo Nishikawa, Mikio Ohno, Masaaki Fujiyama, Tsutomu Okita
  • Patent number: 4906556
    Abstract: An optical recording medium comprising a substrate and a recording layer made of metal and/or semi-metal and on which data can be recorded with a laser beam, wherein a plasma polymerization layer is formed on at least an upper surface of said recording layer.
    Type: Grant
    Filed: July 10, 1989
    Date of Patent: March 6, 1990
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Yasuo Nishikawa, Yonosuke Takahashi
  • Patent number: 4857402
    Abstract: A magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer containing ferromagnetic particles and a binder, wherein the magnetic layer contains at least one lubricating agent selected from the group consisting of a salt of a sulfonic acid and a salt of sulfuric acid ester.
    Type: Grant
    Filed: April 3, 1987
    Date of Patent: August 15, 1989
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Yasuo Nishikawa, Hajime Miyazuka, Nobuo Tsuji