Patents by Inventor Masatoshi Nakayama
Masatoshi Nakayama 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).
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Patent number: 5068146Abstract: A plasma-polymerized film is formed by depositing and polymerizing a metal element-containing material forming an electrode and a gaseous polymerizable carbon-containing reactant in a plasma atmosphere. The polymerized film contains the metal element Mt and carbon C in an atomic ratio Mt/(C+Mt) of at least 1/100. The polymerized film is prepared under a condition W/(F.M) of at least 10.sup.8 joule/kg wherein W is a power applied for plasma generation in joule/sec., F is a flow rate of the gaseous reactant, and M is the molecular weight of the gaseous reactant, F.M being expressed in kg/sec. Such a polymerized film is advantageously applied as a coating to a surface of a member which constructs or is disposed in a casing in which a tape or disk-shaped medium is received for travel or rotating motion.Type: GrantFiled: March 3, 1989Date of Patent: November 26, 1991Assignee: TDK CorporationInventors: Masatoshi Nakayama, Kunihiro Ueda, Masatoshi Okamura
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Patent number: 4988573Abstract: A plasma-polymerized film covers a surface of a medium related member which constructs or is disposed in a casing in which a tape or disk-shaped recording medium is receiving for travel or rotating motion. The film contains C, F and at least one element of Si, B, P and N. The total content of F and at least one element of Si, B, P, and N ranges from 5 to 40 atom % of the film, and the atomic ratio of (Si+B+P+N)/F ranges from 2/10 to 5/1.Type: GrantFiled: July 13, 1989Date of Patent: January 29, 1991Assignee: TDK CorporationInventors: Masatoshi Nakayama, Kunihiro Ueda, Masatoshi Okamura
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Patent number: 4900622Abstract: A magnetic recording medium comprising a ferromagnetic metal thin film comprised predominantly of cobalt on a substrate is improved in durability and performance by forming the ferromagnetic metal thin film as a multi-layered structure including at least two layers, one or both of which contain an organic polymer. A plasma-polymerized film may be provided as an interlayer between the layers of the metal thin film or as a topcoat.Type: GrantFiled: September 16, 1987Date of Patent: February 13, 1990Assignee: TDK CorporationInventors: Masatoshi Nakayama, Koji Kobayashi, Kunihiro Ueda, Mitsuru Takai, Shigeo Kurose
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Patent number: 4892789Abstract: In a magnetic recording medium comprising a substrate, a ferromagnetic metal thin film formed on the substrate, and a topcoat formed on the thin film, the topcoat comprises a plasma-polymerized film containing carbon and hydrogen with the atomic ratio of carbon to hydrogen being from 1 to 6, and an organic material film deposited on the plasma-polymerized film by evaporation.Type: GrantFiled: December 23, 1985Date of Patent: January 9, 1990Assignee: TDK CorporationInventors: Masatoshi Nakayama, Yasufumi Takasugi, Kunihiro Ueda
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Patent number: 4889767Abstract: In a magnetic recording medium wherein a metal thin film magnetic layer and a topcoat layer of an organic fluorine compound are formed on a nonmagnetic substrate, the surface of the magnetic layer is plasma treated or plasma oxidized, enhancing the bond between the adjoining layers. A protective film of carbon may be disposed between the magnetic layer and the topcoat, with the surface of the protective carbon film plasma treated. Instead, a protective film of plasma-polymerized organometallic compound may be used.Type: GrantFiled: April 23, 1987Date of Patent: December 26, 1989Assignee: TDK CorporationInventors: Kenji Yokoyama, Masatoshi Nakayama, Toru Shimozawa, Kunihiro Ueda, Fumio Maruta
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Patent number: 4880687Abstract: In a magnetic recording medium wherein a metal thin film magnetic layer and an overcoat are formed on a nonmagnetic substrate, durability is improved when the overcoat comprises a plasma-polymerized film and a topcoat of an organic fluorine compound; a plasma-polymerized film, a protective carbon film, and a topcoat of an organic fluorine compound; a plasma-polymerized film containing C, F and H; or a plasma-polymerized organometallic film and a fluorine or silicon-containing topcoat. Oxidation of the upper surface of the magnetic layer with a plasma is also effective.Type: GrantFiled: May 6, 1987Date of Patent: November 14, 1989Assignee: TDK CorporationInventors: Kenji Yokoyama, Masatoshi Nakayama, Toru Shimozawa, Kunihiro Ueda, Fumio Maruta
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Patent number: 4863811Abstract: A magnetic recording medium comprising a substrate and a continuous thin film magnetic layer on the substrate is prevented from curling or cupping by incorporating a polymeric organic compound in the magnetic layer. An organic compound is introduced into the magnetic layer during its formation and polymerized with the aid of plasma or radiation. A topcoat is formed on the magnetic layer by plasma polymerizing an organic compound for further improvement.Type: GrantFiled: May 1, 1987Date of Patent: September 5, 1989Assignee: TDK CorporationInventors: Kunihiro Ueda, Masatoshi Nakayama
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Patent number: 4844978Abstract: In a magnetic recording medium comprising a substrate, a ferromagnetic metal thin film formed on the substrate, and a topcoat formed on the thin film, the topcoat is a plasma-polymerized film containing carbon and hydrogen in an atomic ratio of C/H of from 1 to 6, and having a thickness of 10 to 40 angstroms and a contact angle with water in the range of from 60.degree. to 130.degree..Type: GrantFiled: November 6, 1985Date of Patent: July 4, 1989Assignee: TDK CorporationInventors: Masatoshi Nakayama, Yasufumi Takasugi, Kunihiro Ueda
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Patent number: 4824724Abstract: A magnetic recording medium is provided comprising a non-magnetic substrate, a magnetic metal layer of continuous thin film type deposited on the substrate, and a topcoat film on the magnetic layer. The topcoat film is formed by sputtering or ion plating a fluorocarbon resin so that it consists essentially of carbon and fluorine, and fluorine atoms of the topcoat film are chemically combined with metal atoms of the magnetic layer in proximity to the interface.Type: GrantFiled: May 30, 1986Date of Patent: April 25, 1989Assignee: TDK CorporationInventors: Kunihiro Ueda, Yasufumi Takasugi, Masatoshi Nakayama
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Patent number: 4816341Abstract: In a magnetic recording medium comprising a base film and a magnetic layer formed on the base film, the base film has been plasma treated in an atmosphere consisting essentially of an inorganic gas containing N, H, and optionally O at frequencies in the range of 10 to 200 kHz. A perpendicular magnetizable metal thin film layer can be deposited on the plasma-treated surface of a resin substrate having a heat distortion temperature of at least 150.degree. C. without disturbance on the crystal structure of the layer.Type: GrantFiled: December 23, 1985Date of Patent: March 28, 1989Assignee: TDK CorporationInventors: Masatoshi Nakayama, Haruyuki Morita, Yuichi Kubota, Keiko Tsuchiya
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Patent number: 4816334Abstract: In a magnetic recording medium wherein a metal thin film magnetic layer, a protective film or carbon, and a topcoat layer are formed on a rigid substrate in this order, the topcoat layer is from an organic fluorine compound by gas phase deposition.Type: GrantFiled: April 3, 1987Date of Patent: March 28, 1989Assignee: TDK CorporationInventors: Kenji Yokoyama, Masatoshi Nakayama, Fumio Maruta, Kunihiro Ueda
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Patent number: 4810524Abstract: Inorganic powders are coated with a thin film of an organic polymer formed on the individual particles by plasma polymerization. The film thickness may be not more than 100 .ANG., and the inorganic powders include magnetic ones.Type: GrantFiled: December 2, 1986Date of Patent: March 7, 1989Assignee: TDK CorporationInventors: Masatoshi Nakayama, Haruyuki Morita, Yuichi Kubota
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Patent number: 4780354Abstract: A magnetic recording medium comprising a substrate, a plasma polymerized film, and a magnetic layer is improved in physical and electromagnetic properties when the plasma polymerized film is comprised of carbon, or carbon and at least one optional element selected from hydrogen, nitrogen and oxygen.Type: GrantFiled: February 5, 1987Date of Patent: October 25, 1988Assignee: TDK CorporationInventors: Masatoshi Nakayama, Kunihiro Ueda
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Patent number: 4770924Abstract: In a magnetic recording medium comprising a magnetic layer in the form of predominantly cobalt ferromagnetic metal thin film on a plastic substrate, physical properties like strength and crack resistance as well as electromagnetic properties of the magnetic layer are improved by forming it as a multi-layered structure consisting of at least two layers, wherein the magnetic layer has a specific profile of oxygen concentration. The medium may be provided with a topcoat and/or backcoat layer.Type: GrantFiled: July 2, 1987Date of Patent: September 13, 1988Assignee: TDK CorporationInventors: Mitsuru Takai, Koji Kobayashi, Masatoshi Nakayama, Kunihiro Ueda, Shigeo Kurose
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Patent number: 4749608Abstract: A magnetic recording medium comprising a substrate, a ferromagnetic metal thin film on the substrate, and a topcoat on the thin film exhibits improved strength and durability when the topcoat is comprised of a plasma-polymerized film prepared by activating a gaseous hydrocarbon monomer or a mixture thereof with a carrier gas into a plasma under specific conditions. The plasma-polymerized film consists of carbon and hydrogen in an atomic ratio of C/H of from 1:1 to 6:1 and has a thickness of 3 to 15 .ANG. and a contact angle with water in the range from 60.degree. to 120.degree.. An organic coating may be present on the plasma-polymerized film.Type: GrantFiled: April 22, 1987Date of Patent: June 7, 1988Assignee: TDK CorporationInventors: Masatoshi Nakayama, Yasufumi Takasugi, Kunihiro Ueda
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Patent number: 4745031Abstract: In a magnetic recording medium of the hard disk type comprising a rigid substrate and a magnetic layer formed thereon, the substrate is plasma treated at frequencies in the range of 10 to 200 kHz in an inorganic gas containing O; N and H; and N, H and O.Type: GrantFiled: December 26, 1985Date of Patent: May 17, 1988Assignee: TDK CorporationInventors: Masatoshi Nakayama, Haruyuki Morita, Yuichi Kubota, Keiko Tsuchiya
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Patent number: 4737408Abstract: In a magneto-optical recording medium comprising a perpendicular magnetizable thin film layer formed from an amorphous rare earth metal-transition metal alloy on a substrate with or without an intermediate layer, and a first protective layer formed from a plasma-polymerized film on the magnetizable layer; a second protective layer is formed on the first protective layer by curing a radiation-curable compound coating and/or an undercoat layer of a plasma-polymerized film is formed on the substrate in order to improve the moisture proofness of the magnetic layer. The substrate may be plasma treated to improve adherence. Covering the overall outside surface of the medium with a cured film of a radiation-curable compound ensures best shelf stability.Type: GrantFiled: August 18, 1986Date of Patent: April 12, 1988Assignee: TDK CorporationInventors: Tsuneo Kuwahara, Masatoshi Nakayama, Hideki Hirata
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Patent number: 4734810Abstract: A magnetic recording medium comprising a ferromagnetic metal thin film layer formed on one surface of a flexible non-magnetic substrate and primarily comprising cobalt and oxygen is improved in durability by treating the substrate with a plasma at a frequency of 10 kHz to 200 kHz, and providing the magnetic layer on the surface with protrusions having a height of 30 to 300 .ANG. at an average density of at least 10.sup.5 /a.sup.2 per square millimeter of the surface, provided that the magnetic recording medium is passed for recording/reproducing operation across a magnetic head with a gap having a distance a as expressed n .mu.m.Type: GrantFiled: July 24, 1985Date of Patent: March 29, 1988Assignee: TDK CorporationInventors: Masatoshi Nakayama, Kunihiro Ueda, Yuichi Kubota
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Patent number: 4699847Abstract: In a magnetic recording medium comprising a plastic base film and a magnetic layer, the base film is plasma treated at frequencies in the range of 10 kHz to 200 kHz in an inorganic gas containing at least 5% of oxygen. The magnetic layer is formed on the plasma treated base film by applying a magnetic composition of ferromagnetic fine particles dispersed in a plasticized binder compound comprising a radiation-sensitive modified resin in admixture with a radiation-sensitive modified flexible resin or prepolymer, oligomer or telomer thereof, and exposing the composition to radiation for crosslinking and polymerization.Type: GrantFiled: July 24, 1985Date of Patent: October 13, 1987Assignee: TDK CorporationInventors: Masatoshi Nakayama, Haruyuki Morita, Yuichi Kubota, Keiko Tsuchiya
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Patent number: 4619861Abstract: Magnetic powders have a thin film of a nitrogen- or sulfur-containing organic polymer synthesized on the individual particles by plasma polymerization. The film is not more than 100 .ANG. in thickness.Type: GrantFiled: July 19, 1985Date of Patent: October 28, 1986Assignee: TDK CorporationInventors: Masatoshi Nakayama, Haruyuki Morita, Yuichi Kubota