Patents by Inventor Kuniichi Yoda
Kuniichi Yoda 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: 4713278Abstract: A magnetic recording medium comprises a light-shielding base in the form of a tape or sheet, and a magnetic layer composed of a magnetic powder of Co-coated .gamma.-Fe.sub.2 O.sub.3 dispersed in a resin binder and applied to the base. The powder has a specific surface area as determined by the BET adsorption method of at least 35 m.sup.2 /g. The light-shielding base portion contiguous to the magnetic layer is a transparent plastic film and the lower base portion is light-shielding. The light-shielding base has a light transmittance of 30% or below. The surface roughness of the base is, in terms of the center-line average surface roughness, 0.012 .mu.m or below.Type: GrantFiled: September 4, 1986Date of Patent: December 15, 1987Assignee: TDK CorporationInventors: Kuniichi Yoda, Eiji Kitaura, Tsutomu Tsunoda, Yoshio Kawakami
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Patent number: 4621018Abstract: A magnetic recording medium comprising a transparent support and a magnetic layer formed on the support, said magnetic layer comprising Co-adsorbed Fe.sub.3 O.sub.4 and Co-adsorbed .gamma.-Fe.sub.2 O.sub.3 in a weight ratio of from 40:60 to 80:20, each of said Co-adsorbed Fe.sub.3 O.sub.4 and Co-adsorbed .gamma.-Fe.sub.2 O.sub.3 having a particle size of at least 25 m.sup.2 /g as a BET value.Type: GrantFiled: February 14, 1985Date of Patent: November 4, 1986Assignee: TDK CorporationInventors: Kuniichi Yoda, Kaoru Kawasaki
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Patent number: 4615949Abstract: A magnetic recording medium comprises a magnetic coating material, or a dispersion of magnetic particles in a resinous binder, and a base to which the coating material is solidly applied, the resinous binder comprising as its ingredients a copolymer composed of vinyl chloride, vinylidene chloride, a vinyl alkylcarboxylate, another monomer copolymerizable with vinyl chloride, and a saponified vinyl alkylcarboxylate and having an OH/CH absorption ratio according to the infrared absorption spectrum of at least 0.2, a polyurethane resin having in its molecule a --SO.sub.3 M group wherein M represents an alkali metal atom, and a polyisocyanate.Type: GrantFiled: July 12, 1985Date of Patent: October 7, 1986Assignee: TDK CorporationInventors: Kuniichi Yoda, Yuji Ishihara, Hitoshi Azegami
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Patent number: 4608315Abstract: A magnetic recording medium comprising a resinous component in which magnetic particles are dispersed and a base to which the dispersion is solidly applied, the resinous component consisting of a copolymer having an OH/CH absorption ratio according to the infrared absorption spectrum of 0.2 or more and made from (A) vinyl chloride, (B) vinylidene chloride, (C) a vinyl alkylcarboxylate, (D) an other monomer copolymerizable with vinyl chloride, and (E) a saponified vinyl alkylcarboxylate, and a rubbery binder. Alternatively, a polyisocyanate is added to the above copolymer.Type: GrantFiled: April 16, 1985Date of Patent: August 26, 1986Assignee: TDK CorporationInventors: Kuniichi Yoda, Yuji Ishihara, Hitoshi Azegami
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Patent number: 4436786Abstract: A magnetic recording medium is provided which has smooth and stable running performances and is free of "squeal" phenomenon, especially in an environment of high temperature and high humidity. A highly viscous silicone oil having a viscosity of 100,000 centistokes or more is incorporated in combination with a higher fatty having a melting point of 44.degree. C. or more into a magnetic coating layer of the magnetic recording medium. Such silicone oil is represented by the general formula: ##STR1## wherein R is CH.sub.3, R' is CH.sub.3, C.sub.6 H.sub.5 or F and n is a number which determines a viscosity thereof. Such higher fatty acid is selected from lauric acid, myristic acid, palmitic acid, stearic acid, arachic acid, behenic acid and the like.Type: GrantFiled: March 31, 1982Date of Patent: March 13, 1984Assignee: TDK Electronics Co., Ltd.Inventors: Takehisa Ohkawa, Kuniichi Yoda
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Patent number: 4416948Abstract: A magnetic recording medium is provided which has smooth and stable running performances and is free of "squeal" phenomenon, especially in an environment of high temperature and high humidity. A highly viscous silicone oil having a viscosity of 100,000 centistokes or more is incorporated in combination with a higher fatty acid glycerine ester composed of a higher fatty acid having a melting point of 44.degree. C. or more and glycerine into a magnetic coating layer of the magnetic recording medium. Such silicone oil is represented by the general formula: ##STR1## wherein R is CH.sub.3, R' is CH.sub.3, C.sub.6 H.sub.5 or F and n is a number which determines a viscosity thereof. Such higher fatty glycerine ester is selected from monoglyceride of myristic acid, monoglyceride of palmitic acid, monoglyceride of stearic acid, monoglyceride of oleic acid and the like.Type: GrantFiled: March 31, 1982Date of Patent: November 22, 1983Assignee: TDK Electronics Co., Ltd.Inventors: Takehisa Ohkawa, Kuniichi Yoda
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Patent number: 4416947Abstract: A magnetic recording medium is provided which has smooth and stable running performances and is free of "squeal" phenomenon, especially in an environment of high temperature and high humidity. A highly viscous silicone oil having a viscosity of 100,000 centistokes or more is incorporated in combination with a higher fatty acid ester composed of a higher fatty having a melting point of 44.degree. C. or more and a monohydric alcohol containing 3 to 8 carbon atoms into a magnetic coating layer of the magnetic recording medium. Such silicone oil is represented by the general formula: ##STR1## wherein R is CH.sub.3, R' is CH.sub.3, C.sub.6 H.sub.5 or F and n is a number which determines a viscosity thereof. Such higher fatty acid ester is selected from butyl myristate, butyl palmitate, propyl stearate, butyl stearate and the like.Type: GrantFiled: March 31, 1982Date of Patent: November 22, 1983Assignee: TDK Electronics Co. Ltd.Inventors: Kuniichi Yoda, Takehisa Ohkawa
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Patent number: 4409300Abstract: A magnetic recording medium is provided which has smooth and stable running performances and is free of "squeal" phenomenon, especially in an environment of high temperature and high humidity. A highly viscous silicone oil having a viscosity of 100,000 centistokes or more is incorporated in combination with a sorbitan fatty acid ester into a magnetic coating layer of the magnetic recording medium. Such silicone oil is represented by the general formula: ##STR1## wherein R is CH.sub.3, R' is CH.sub.3, C.sub.6 H.sub.5 or F and n is a number which determines a viscosity thereof. Such sorbitan fatty acid ester is selected from sorbitan monopalmitate, sorbitan monostearate, sorbitan distearate, sorbitan tristearate, sorbitan monooleate and the like.Type: GrantFiled: March 31, 1982Date of Patent: October 11, 1983Assignee: TDK Electronics Co., Ltd.Inventors: Takehisa Ohkawa, Kuniichi Yoda
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Patent number: 4400435Abstract: A magnetic recording medium comprises a substrate coated with a magnetic layer comprising a magnetic powder and a binder comprising an urethane resin and a vinyl chloride-vinyl acetate-maleic acid copolymer having a content of maleic acid component of at least 1.5%.Type: GrantFiled: July 15, 1981Date of Patent: August 23, 1983Assignee: TDK Electronics Co., Ltd.Inventors: Kuniichi Yoda, Takehisa Ohkawa, Hitoshi Azegami
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Patent number: 4352859Abstract: A magnetic recording medium comprises a substrate coated with a magnetic layer comprising a magnetic powder and a binder comprising an urethane resin or a polyester and a vinyl chloride type copolymer of vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer or vinyl chloride-vinylidene chloride copolymer having a polymerization degree of up to 300.Type: GrantFiled: July 20, 1981Date of Patent: October 5, 1982Assignee: TDK Electronics Co., Ltd.Inventors: Kuniichi Yoda, Takehisa Ohkawa, Hitoshi Azegami