Patents by Inventor Eiichi Tadokoro

Eiichi Tadokoro 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: 4931378
    Abstract: Disclosed is a method for processing a silver halide photographic material having at least one silver halide emulsion layer on a support and containing at least one hydrazine derivative in said silver halide emulsion layer or in another hydrophilic colloid layer with a roller-conveying type automatic developing machine using a dihydroxybenzene developer containing a sulfite preservative in an amount of 0.15 mol/liter or more at pH of 10.5 to 12.3, which method is characterized in that at least the roller which is in contact with both the developer and air, among the rollers of the said developing machine, is continuously rotated at a determined speed during conveyance or processing of the material during a processing phase, and intermittently rotated during a stand-by phase. By the method, the photographic material may be processed stably and rapidly for a long period of time to give an image having a high contrast and a high blackened density.
    Type: Grant
    Filed: December 5, 1988
    Date of Patent: June 5, 1990
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masato Hirano, Eiichi Tadokoro
  • Patent number: 4822672
    Abstract: An abrasive tape comprises a flexible non-magnetic substrate, and an abrasive coating film applied onto the flexible non-magnetic substrate and formed by kneading abrasive grains, a binder and an additive. The binder contains a resin which has, at a side chain, at least one polar group selected from the group consisting of ##STR1## where M represents a hydrogen atom, lithium, sodium, or potassium, M.sub.1 represents a hydrogen atom, lithium, sodium, potassium, or an alkyl group, and M.sub.2 represents a hydrogen atom, lithium, sodium, potassium, or an alkyl group.
    Type: Grant
    Filed: February 27, 1987
    Date of Patent: April 18, 1989
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Nobutaka Yamaguchi, Eiichi Tadokoro, Takahito Miyoshi
  • Patent number: 4764423
    Abstract: An abrasive tape comprises a flexible non-magnetic substrate, and an abrasive coating film applied onto the flexible non-magnetic substrate and formed by kneading an abrasive material, a binder, and a lubricant essentially consisting of a fatty acid, a fatty acid ester, a silicone oil, and a surface active agent.
    Type: Grant
    Filed: October 17, 1986
    Date of Patent: August 16, 1988
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Nobutaka Yamaguchi, Eiichi Tadokoro
  • Patent number: 4758468
    Abstract: The present invention relates to a magnetic recording medium which comprises a non-magnetic support having coated on opposite surfaces thereof a magnetic layer and a backing layer comprising a resin as a binder and non-magnetic particles, wherein the resin binder contains a polyurethane resin, a copolymer of vinylidene chloride and acrylonitrile, and a polyisocyanate compound; the non-magnetic particles contains fine carbon black having an average particle size of 30 to 150 m.mu. and coarse carbon black having an average particle size of 160 to 600 m.mu.; and the mixing weight ratio of the resin binder to the non-magnetic particles is within the range of 0.375:1 to 1:1 by weight. This magnetic recording medium has excellent electromagnetic properties and running durability.
    Type: Grant
    Filed: October 4, 1985
    Date of Patent: July 19, 1988
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masatoshi Takahashi, Katsumi Ryoke, Nobuyoshi Asada, Eiichi Tadokoro
  • Patent number: 4756960
    Abstract: An abrasive tape comprises a flexible non-magnetic substrate, and an abrasive coating film essentially consisting of an abrasive material, a binder and an additive kneaded together and applied onto the flexible non-magnetic substrate. The abrasive material has a Mohs hardness of 6 or higher, and the binder essentially consists of a vinyl chloride-vinyl acetate copolymer, a prepolymer having an isocyanate group at a terminal, and an organic amine.
    Type: Grant
    Filed: October 17, 1986
    Date of Patent: July 12, 1988
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Nobutaka Yamaguchi, Eiichi Tadokoro
  • Patent number: 4752524
    Abstract: An abrasive tape comprises a flexible non-magnetic substrate, and an abrasive coating film applied onto the flexible non-magnetic substrate and formed by kneading an abrasive material and a binder essentially consisting of a vinyl chloride-vinyl acetate-maleic acid copolymer, a polyamide resin and an epoxy resin.
    Type: Grant
    Filed: October 17, 1986
    Date of Patent: June 21, 1988
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Nobutaka Yamaguchi, Eiichi Tadokoro
  • Patent number: 4734325
    Abstract: A magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer being provided on one surface of the support and a backing layer being provided on the surface of the support opposite to said magnetic layer, the backing layer contains binder and non-magnetic particles comprised of (i) corbon black having an average particle size of 0.1 to 1.0 .mu.m and (ii) particles of abrasives having a Mohs' hardness of at least 6 and an average particle size of 1 .mu.m or less, with the non-magnetic particles in said backing layer being used in an amount of 40 to 300 parts by weight per 100 parts by weight of binder.
    Type: Grant
    Filed: October 4, 1985
    Date of Patent: March 29, 1988
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsumi Ryoke, Nobutaka Yamaguchi, Masatoshi Takahashi, Kazuko Hanai, Hideaki Kosha, Eiichi Tadokoro
  • Patent number: 4731278
    Abstract: A magnetic recording medium is described, comprising a magnetic layer containing ferromagnetic fine particles and a binder coated on one side of a non-magnetic support and a backing layer coated on the opposite side of the non-magnetic support, wherein said ferromagnetic fine particles have a cobalt content of from 2 to 10 wt % with respect to the iron oxide content thereof, the content of divalent iron (Fe.sup.2+) of from 1 to 10 wt % with respect to the trivalent iron (Fe.sup.3+) content thereof, and the specific surface area of from 30 to 50 m.sup.2 /g, said binder comprises a copolymer of vinyl chloride-vinyl acetate-maleic acid contained in an amount of 40 wt % or more with respect to the total binder content of the magnetic layer, an abrasive agent having a Mohs hardness of 6 or more is contained in said magnetic layer, and the resulting magnetic tape has a coercive force of from 750 to 900 Oe at 25.degree. C.
    Type: Grant
    Filed: May 13, 1986
    Date of Patent: March 15, 1988
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsumi Ryoke, Masatoshi Takahashi, Eiichi Tadokoro
  • Patent number: 4728569
    Abstract: A magnetic recording medium is described, comprising a magnetic layer coated on one side of a non-magnetic support and a backing layer coated on the opposite side of the non-magnetic support, wherein the backing layer is provided after the magnetic layer has been subjected to calendering treatment and the backing layer comprises (i) non-magnetic particles including carbon black particles having an average particle diameter of from 0.1 to 1 .mu.m and (ii) a binder composition comprising from 50 to 95 wt % of a resin having a 100% modulus at 150 kg/cm.sup.2 or less based on the total weight of the binder composition, and the weight ratio of non-magnetic particles to binder composition contained in the backing layer is from 300/100 to 40/100.
    Type: Grant
    Filed: November 19, 1985
    Date of Patent: March 1, 1988
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsumi Ryoke, Nobutaka Yamaguchi, Masatoshi Takahashi, Kazuko Hanai, Hideaki Kosha, Eiichi Tadokoro
  • Patent number: 4696858
    Abstract: A magnetic recording medium is described, comprising a non-magnetic support having provided thereon a magnetic layer being provided on one surface of the support and a backing layer being provided on the surface of the support opposite to said magnetic layer, the backing layer containing (A) a binder comprised of resin having a 100% modulus of 150 kg/cm.sup.2 or less present in an amount of 50 to 95 wt % based on the total weight amount of binder and (B) non-magnetic particles comprised of (i) carbon black having an average particle size of more than 0.1 .mu.m to 1.0 .mu.m, and (ii) carbon black having an average particle size of 0.01 .mu.m to 0.1 .mu.m in a weight ratio of carbon black (i)/carbon black (ii) of 95/5 to 5/95, with the non-magnetic particles in the backing layer being present in an amount of 40 to 300 parts by weight per 100 parts by weight of the total binder.
    Type: Grant
    Filed: October 18, 1985
    Date of Patent: September 29, 1987
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsumi Ryoke, Nobutaka Yamaguchi, Masatoshi Takahashi, Kazuko Hanai, Hideaki Kosha, Eiichi Tadokoro
  • Patent number: 4693929
    Abstract: A magnetic recording medium comprising a magnetic layer coated on one side of a non-magnetic support and a backing layer coated on the opposite side of the non-magnetic support, wherein the backing layer comprises non-magnetic particles, a binder and silicone having a viscosity of from 1 to 50 CS (centistokes) at 25.degree. C. in an amount of from 0.01 to 3 wt. % based on the non-magnetic particles, wherein the non-magnetic particles contain carbon black in an amount of at least 50 wt. % based on the total amount of the non-magnetic particles, and wherein 25 wt. % or more of the carbon black has an average particle size of from 150 to 1,000 m.mu..
    Type: Grant
    Filed: October 4, 1985
    Date of Patent: September 15, 1987
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsumi Ryoke, Masatoshi Takahashi, Takashi Yoneyama, Yasuo Nishikawa, Eiichi Tadokoro
  • Patent number: 4686139
    Abstract: A magnetic recording medium is described, comprising a non-magnetic support having a magnetic layer and a backing layer which is provided on the surface of the support opposite to the magnetic layer, the backing layer containing (a) non-magnetic particles comprising carbon black having an average particle diameter of 0.1 to 1.0 .mu.m, (b) a binder comprising (i) a resin having 150 kg/cm.sup.2 or less of 100% modulus in an amount of at least 50 wt % based on the total amount of binder, and (ii) a diphenyl methane diisocyanate type hardening agent, with the amount of non-magnetic particles to total contained in the backing layer being 40 to 300 parts by weight of non-magnetic particles per 100 parts by weight of binder.
    Type: Grant
    Filed: September 20, 1985
    Date of Patent: August 11, 1987
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsumi Ryoke, Nobutaka Yamaguchi, Masatoshi Takahashi, Kazuko Hanai, Hideaki Kosha, Eiichi Tadokoro
  • Patent number: 4663217
    Abstract: A magnetic recording medium comprised of a nonmagnetic support base having a magnetic recording layer on one surface thereof and a backing layer on the other surface thereof is disclosed. The backing layer is comprised of (1) carbon black having a particle size in the range of 10 to 150 m.mu., (2) graphite having a particle size of 3.mu. or less, and (3) a curing agent. By utilizing this particular backing layer the resulting recording medium has improved durability with respect to the backing layer and shows a decreased in the number of dropouts and scratches during use.
    Type: Grant
    Filed: August 19, 1985
    Date of Patent: May 5, 1987
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Nobutaka Yamaguchi, Shinobu Iida, Masahiro Utsumi, Norio Nasu, Eiichi Tadokoro
  • Patent number: 4650720
    Abstract: A magnetic recording medium is disclosed which comprises a non-magnetic support having provided thereon a magnetic recording layer and a backing layer on the opposite surface thereof, wherein said magnetic recording layer contains a fatty acid, said backing layer contains a cellulose resin, and said non-magnetic support has a Young's modulus of 7.times.10.sup.10 to 1.times.10.sup.13 dyn/cm.sup.2.
    Type: Grant
    Filed: April 11, 1984
    Date of Patent: March 17, 1987
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Nobutaka Yamaguchi, Takahito Miyoshi, Toshimitu Okutu, Noburo Hibino, Eiichi Tadokoro, Masaaki Fujiyama
  • Patent number: 4649072
    Abstract: A magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer on one side and a backing layer on the other side, wherein the backing layer contains (1) non-magnetic powders containing carbon black having an average particle diameter of from 0.1 to 1 .mu.m; (2) two or more binders wherein (a) at least one of the binders is a resin having a 100% modulus of from 15 to 150 kg/cm.sup.2 in an amount of from 50 to 95 wt % based on the total amount of the binders in the backing layer, and (b) the rest binder(s) is/are a resin other than the resin having a 100% modulus of from 15 to 150 kg/cm.sup.2, and the weight ratio of all the non-magnetic powders to all the binders in the backing layer is from 300:100 to 40:100; and (3) a polyisocyanate in an amount of from 15 to 40 wt % based on the total amount of the binders in the backing layer.
    Type: Grant
    Filed: September 23, 1985
    Date of Patent: March 10, 1987
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsumi Ryoke, Nobutaka Yamaguchi, Masatoshi Takahashi, Kazuko Hanai, Hideaki Kosha, Eiichi Tadokoro
  • Patent number: 4614685
    Abstract: A magnetic recording medium comprised of a non-magnetic support base having a magnetic layer provided thereon is disclosed. The magnetic layer is comprised of carbon black having an average particle size of 30 to 50 m.mu. and an iron oxide which contains Co. The iron oxide containing the Co has a specific surface area of 25 m.sup.2 /g or more. The carbon black and the iron oxide containing the Co are dispersed in a binder. By utilizing the particular type of carbon black in combination with the particular iron oxide containing Co in the magnetic layer it is possible to greatly improve the running characteristics of the magnetic recording medium as well as obtain an improved RF output.
    Type: Grant
    Filed: April 9, 1984
    Date of Patent: September 30, 1986
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsumi Ryoke, Kenichi Masuyama, Eiichi Tadokoro
  • Patent number: 4601946
    Abstract: A magnetic recording medium is disclosed which comprises a non-magnetic support having provided thereon a magnetic recording layer consisting ferromagnetic powder and containing graphite and a fatty acid ester.
    Type: Grant
    Filed: July 26, 1984
    Date of Patent: July 22, 1986
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Shinobu Iida, Nobutaka Yamaguchi, Fumiaki Tsukuda, Masaaki Fujiyama, Eiichi Tadokoro
  • Patent number: 4582754
    Abstract: A magnetic recording medium comprising a support having provided thereon a magnetic recording layer containing (1) a cobalt-containing iron oxide, (2) graphite, and (3) a copolymer of vinyl chloride, vinyl acetate and maleic acid.
    Type: Grant
    Filed: July 26, 1984
    Date of Patent: April 15, 1986
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsumi Ryoke, Shinobu Iida, Masaaki Fujiyama, Eiichi Tadokoro
  • Patent number: 4579778
    Abstract: A magnetic recording medium is disclosed which comprises a non-magnetic support, having a Young's modulus of 7.times.10.sup.10 to 1.times.10.sup.13 dyn/cm.sup.2, having coated on opposite surfaces, a magnetic recording layer comprising ferromagnetic particles and a fatty acid ester and a backing layer comprising a cellulose resin.
    Type: Grant
    Filed: April 25, 1984
    Date of Patent: April 1, 1986
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Nobutaka Yamaguchi, Norio Nasu, Eiichi Tadokoro, Masaaki Fujiyama
  • Patent number: 4552799
    Abstract: A magnetic recording medium comprised of a non-magnetic support base having provided thereon a magnetic recording layer is disclosed. The medium also has position thereon a compound selected from the group consisting of carboxylic acids and carboxylic acid derivatives, the compound being present on an edge portion of the medium. The medium also includes an additional lubricant on the middle part of the medium, the additional lubricant being selected from the group consisting of alphatic acid esters, alphatic acids, silicons and phosphoric acid esters. By utilizing two different types of lubricants on different portions of the medium it is possible to obtain improved lubricating properties and thus improve runnability with respect to the operation of the magnetic recording medium.
    Type: Grant
    Filed: April 23, 1984
    Date of Patent: November 12, 1985
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsumi Ryoke, Shinobu Iida, Masaaki Fujiyama, Eiichi Tadokoro