Patents by Inventor Teiji Kohara

Teiji Kohara 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: 6633722
    Abstract: A light guide plate which is made of a polymeric resin having an alicyclic structure and has recesses for reflection formed on a light reflecting surface, the recesses being so arranged that the density of the recesses increases with the distance from a light source. Each recess is preferably a V-shaped groove each having an angle of 70° to 150° and a depth of 1 &mgr;m to 1000 &mgr;m or a groove which is long and approximately perpendicular to the direction in which light is incident at any position on the light reflection surface.
    Type: Grant
    Filed: October 27, 2000
    Date of Patent: October 14, 2003
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Teiji Kohara, Yuichiro Konishi, Junko Maruyama, Koji Minami, Issei Ishimaru
  • Patent number: 6630234
    Abstract: By using a polymeric film having a dielectric loss tangent of 0.002 or less measured at a frequency in the range of 1 kHz to 1 GHz at a temperature of 25 ° C., heat generation of dielectric loss of capacitors can be reduced and rising of temperature can be inhibited, and, can highly stand the rise of temperature, whereby further miniaturization and increase in capacity of capacitors become possible. Furthermore, the problems in handling that the films are apt to cut or become entangled at the rewinding step can be greatly improved by using polymeric films which are 1 or less in friction coefficient between the films of the same material. Accordingly, the polymeric films are excellent in performance of insulator film, namely, small in dielectric loss tangent, and, moreover, are free from the problems in handling that the films are apt to cut or become entangled at the rewinding step. Furthermore, the polymeric films are suitable for film capacitors.
    Type: Grant
    Filed: December 20, 1999
    Date of Patent: October 7, 2003
    Assignee: Nippo Zeon Co., Ltd.
    Inventors: Hajime Tanisho, Yuichiro Konishi, Teiji Kohara
  • Patent number: 6500899
    Abstract: A molded or formed product obtained by molding or forming a resin composition comprising (A) at least one vinyl cyclic hydrocarbon polymer selected from the group consisting of hydrogenated products of aromatic vinyl polymers, vinylcyclohexene polymers or hydrogenated products thereof, and vinylcyclohexane polymers, and (B) at least one substance selected from the group consisting of compounding additives incompatible with the polymer, organic compounds having at least one alcoholic hydroxyl group and at least one ether linkage, and organic compounds having at least one alcoholic hydroxyl group and at least one ester linkage, wherein the initial light transmittance (a) of the molded or formed product at an optional wavelength within a range of 400 to 800 nm and the light transmittance (b) of the molded or formed product after the molded or formed product is held for 1,000 hours in an atmosphere of 65° C.
    Type: Grant
    Filed: November 21, 2001
    Date of Patent: December 31, 2002
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Teruhiko Suzuki, Tsutomu Nagamune, Teiji Kohara
  • Patent number: 6498215
    Abstract: A molded or formed product obtained by molding or forming a resin composition comprising (A) at least one vinyl cyclic hydrocarbon polymer selected from the group consisting of hydrogenated products of aromatic vinyl polymers, vinylcyclohexene polymers or hydrogenated products thereof, and vinylcyclohexane polymers, and (B) at least one substance selected from the group consisting of compounding additives incompatible with the polymer, organic compounds having at least one alcoholic hydroxyl group and at least one ether linkage, and organic compounds having at least one alcoholic hydroxyl group and at least one ester linkage, wherein the initial light transmittance (a) of the molded or formed product at an optional wavelength within a range of 400 to 800 nm and the light transmittance (b) of the molded or formed product after the molded or formed product is held for 1,000 hours in an atmosphere of 65° C.
    Type: Grant
    Filed: November 21, 2001
    Date of Patent: December 24, 2002
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Teruhiko Suzuki, Tsutomu Nagamune, Teiji Kohara
  • Patent number: 6433102
    Abstract: A hydrogenated product of an aromatic vinyl polymer, wherein the hydrogenation rate of the aromatic rings thereof is at least 97%, a ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is at most 2.0, the weight average molecular weight (Mw) is 100,000 to 300,000, and the content of a component having a molecular weight (M) of at most 10,000 is at most 2% by weight based on the total weight of the polymer; a hydrogenated product of an aromatic vinyl polymer, wherein the content of foreign matter having a particle diameter of at least 0.5 &mgr;m in the hydrogenated polymer is at most 3.0×104 particles/g; and a substrate for information recording media obtained by molding a resin material containing a hydrogenated product of an aromatic vinyl polymer, wherein the hydrogenation rate of the aromatic rings thereof is at least 97%, a :ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is at most 2.
    Type: Grant
    Filed: September 4, 2001
    Date of Patent: August 13, 2002
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Teruhiko Suzuki, Tsutomu Nagamune, Teiji Kohara, Toshihide Murakami, Haruhiko Takahashi
  • Patent number: 6365660
    Abstract: A molded or formed product obtained by molding or forming a resin composition comprising (A) at least one vinyl cyclic hydrocarbon polymer selected from the group consisting of hydrogenated products of aromatic vinyl polymers, vinylcyclohexene polymers or hydrogenated products thereof, and vinylcyclohexane polymers, and (B) at least one substance selected from the group consisting of compounding additives incompatible with the polymer, organic compounds having at least one alcoholic hydroxyl group and at least one ether linkage, and organic compounds having at least one alcoholic hydroxyl group and at least one ester linkage, wherein the initial light transmittance (a) of the molded or formed product at an optional wavelength within a range of 400 to 800 nm and the light transmittance (b) of the molded or formed product after the molded or formed product is held for 1,000 hours in an atmosphere of 65° C.
    Type: Grant
    Filed: January 26, 2000
    Date of Patent: April 2, 2002
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Teruhiko Suzuki, Tsutomu Nagamune, Teiji Kohara
  • Publication number: 20020032264
    Abstract: A molded or formed product obtained by molding or forming a resin composition comprising (A) at least one vinyl cyclic hydrocarbon polymer selected from the group consisting of hydrogenated products of aromatic vinyl polymers, vinylcyclohexene polymers or hydrogenated products thereof, and vinylcyclohexane polymers, and (B) at least one substance selected from the group consisting of compounding additives incompatible with the polymer, organic compounds having at least one alcoholic hydroxyl group and at least one ether linkage, and organic compounds having at least one alcoholic hydroxyl group and at least one ester linkage, wherein the initial light transmittance (a) of the molded or formed product at an optional wavelength within a range of 400 to 800 nm and the light transmittance (b) of the molded or formed product after the molded or formed product is held for 1,000 hours in an atmosphere of 65° C.
    Type: Application
    Filed: November 21, 2001
    Publication date: March 14, 2002
    Inventors: Teruhiko Suzuki, Tsutomu Nagamune, Teiji Kohara
  • Publication number: 20020032265
    Abstract: A molded or formed product obtained by molding or forming a resin composition comprising (A) at least one vinyl cyclic hydrocarbon polymer selected from the group consisting of hydrogenated products of aromatic vinyl polymers, vinylcyclohexene polymers or hydrogenated products thereof, and vinylcyclohexane polymers, and (B) at least one substance selected from the group consisting of compounding additives incompatible with the polymer, organic compounds having at least one alcoholic hydroxyl group and at least one ether linkage, and organic compounds having at least one alcoholic hydroxyl group and at least one ester linkage, wherein the initial light transmittance (a) of the molded or formed product at an optional wavelength within a range of 400 to 800 nm and the light transmittance (b) of the molded or formed product after the molded or formed product is held for 1,000 hours in an atmosphere of 65° C.
    Type: Application
    Filed: November 21, 2001
    Publication date: March 14, 2002
    Inventors: Teruhiko Suzuki, Tsutomu Nagamune, Teiji Kohara
  • Patent number: 6277923
    Abstract: The object of the present invention is to provide a cycloolefin-based polymer with very low content of foreign matters, a molded article obtained by using the cycloolefin-based polymer, and a process for producing the cycloolefin-based polymer. The present invention relates to a cycloolefin-based polymer which has an intrinsic viscosity [&eegr;] of 0.01-20 dl/g as determined in decalin at 80° C. and has a content of foreign matters having a particle diameter of 0.5 &mgr;m or more of 3×104 particles/g or less, a process for producing the cycloolefin-based polymer, and a molded material comprising the cycloolefin-based polymer and a molded article obtained therefrom.
    Type: Grant
    Filed: August 20, 1997
    Date of Patent: August 21, 2001
    Assignee: Nippon Zeon Co., LTD
    Inventors: Teiji Kohara, Toshihide Murakami
  • Patent number: 6066380
    Abstract: A molded thermoplastic resin disc substrate specially adapted for use with floating head type recording/reproduction apparatus is provided. The molded disc substrate has surface smoothness characteristics which are the same or better than are provided with mirror polished aluminum discs. The molded disc substrates include a floating head scanning surface wherein the maximum projection height or maximum surface irregularity is less than about 50 nm to reduce or eliminate damage to either the disc or floating head caused by unwanted collisions between them. In a preferred embodiment, the molded disc substrates are molded from a thermoplastic resin composition containing 10000 particles/gram or less of particles having a particle diameter of 0.5 .mu.m or more. In a preferred embodiment, control of particle size and content is achieved by subjecting the resin molding composition to a sequence of filtering steps using filters of decreasing mesh size.
    Type: Grant
    Filed: October 13, 1998
    Date of Patent: May 23, 2000
    Assignees: Sony Corporation, Nippon Zeon Co., Ltd.
    Inventors: Eiki Oyanagi, Takeshi Sasa, Yasuyuki Imai, Hiroshi Takino, Teiji Kohara, Masayoshi Oshima
  • Patent number: 6030255
    Abstract: An insulator for high frequency connectors which comprises a thermoplastic norbornene resin and has a voltage and standing wave ratio of 1.89 or less even in the high frequency band of 2-3 GHz, and a high frequency connector using the insulator.
    Type: Grant
    Filed: July 23, 1997
    Date of Patent: February 29, 2000
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Yuichiro Konishi, Hajime Tanisho, Yuji Koshima, Teiji Kohara
  • Patent number: 5885505
    Abstract: A molding frame made by molding a thermoplastic norbornene resin which hardly deforms even after repeated use is used for production of electronic part sealed bodies by sealing the electronic devices of integrated circuits such as light emitting diodes, diodes, transistors, LSI devices, IC devices and CCD devices and capacitors, resistors, coils, microswitches and dipswitches with thermosetting resins such as epoxy resins as sealants.
    Type: Grant
    Filed: August 25, 1997
    Date of Patent: March 23, 1999
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Yuji Koushima, Teiji Kohara, Tadao Natsuume
  • Patent number: 5856395
    Abstract: The present invention relates to a resin composition having a high dielectric constant and a low dielectric loss tangent under high frequency conditions and articles obtained therefrom. The resin composition comprises 100 parts by weight of thermoplastic resin and 50-900 parts by weight of ferroelectric material. The formed articles can be used as substrates for a miniaturized antenna or circuit.
    Type: Grant
    Filed: November 20, 1996
    Date of Patent: January 5, 1999
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Hajime Tanisho, Yuji Koshima, Teiji Kohara
  • Patent number: 5725960
    Abstract: A molded article having an adhesion of at least 50 squares per 100 squares in crosscut adhesion test and at least 40 squares per 100 squares even after kept in a warm water of 70.degree. C. for 1 hour, a haze value of 1.0% or less in Taber abrasion test and a pencil hardness of 2H or higher, said molded article being obtained by modifying the surface of a substrate formed of a thermoplastic norbornene resin to have a surface tension of 50 dynes/cm or greater by a treatment such as corona discharge treatment or the like or forming a preliminary primer layer of a modified product obtained by introducing a polar group into a copolymer of a vinyl aromatic compound and a conjugated diene, or the like; forming a primer layer for silicone hard coating agent on the modified surface or the preliminary primer layer, and then forming thereon a silicone hard coat layer, and a method for producing the molded article.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: March 10, 1998
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Yuichiro Konishi, Tohru Hosaka, Mitsushi Tada, Tadao Natsuume, Nobukazu Takahashi, Teiji Kohara
  • Patent number: 5686156
    Abstract: A press-through package obtained by placing objects to be packed, in the accommodating pockets formed by vacuum forming or the like of a sheet made of a thermoplastic norbornene type resin, particularly preferably a hydrogenated product of ring-opening polymerization product of a dicyclopentadiene type monomer, and then closing the openings of pockets of the sheet with another sheet such as metal foil to pack the objects to be packed, which package makes the packed objects clearly visible in the pocket portions, prevents the deterioration of the packed objects by moisture bacause of its excellent water vapor barrier properties, and is good in production efficiency.
    Type: Grant
    Filed: June 26, 1995
    Date of Patent: November 11, 1997
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Toshiyasu Matsui, Tsutomu Hani, Teiji Kohara, Tadao Natsuume
  • Patent number: 5681900
    Abstract: A resin obtained by subjecting a norbornene type monomer having an aromatic ring structure (e.g. 5-phenyl-2-norbornene) to ring-opening polymerization and hydrogenating 95% or more of the unsaturated bonds in the backbone structure of the resulting polymer by the use of a catalyst composed of a combination of a transition metal compound and an alkyl metal compound, while leaving 80% or more of the aromatic ring structures, which resin has not only a high refractive index but also characteristics of a hydrogenated norbornene ring-opening polymerization product, i.e., excellent heat resistance, transparency, low birefringent properties, weather resistance, light resistance, low water absorption properties, moisture resistance, small dielectric constant, small dielectric loss, chemical resistance, etc., said resin being usable in optical materials, medical tools and materials, tools and materials for treating electronic parts, etc.
    Type: Grant
    Filed: January 22, 1996
    Date of Patent: October 28, 1997
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Toshihide Murakami, Teiji Kohara, Tadao Natsuume
  • Patent number: 5665795
    Abstract: A resin composition comprising 30-95 parts by weight of a thermoplastic norbornene resin and 5-70 parts by weight of a spherical inorganic filler having an average particle diameter of 0.05-50 .mu.m; and a precision molding produced therefrom.
    Type: Grant
    Filed: June 26, 1995
    Date of Patent: September 9, 1997
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Yuji Koushima, Teiji Kohara, Tadao Natsuume
  • Patent number: 5599882
    Abstract: The present invention discloses a polycyclic norbornene-based ring-opening polymer which comprises(A) 90-5% by mol of a repeating unit represented by the following formula [I] or the alkyl-substituted derivative thereof, and(B) 10-95% by mol of at least one repeating unit selected from a repeating unit represented by the following formula [II], the alkyl-substituted derivative thereof, a repeating unit represented by the following formula [III], the alkyl-substituted derivative thereof, or the alkylidene-substituted derivative thereof, and which has an intrinsic viscosity [.eta.] of 0.01-20 dl/g as determined in toluene at 25.degree. C., the hydrogenation products thereof, and a process for production thereof ##STR1## wherein ------ denotes a single bond or a double bond.
    Type: Grant
    Filed: February 13, 1990
    Date of Patent: February 4, 1997
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Yoshikatsu Nishi, Masayoshi Ohshima, Teiji Kohara, Toshiyasu Matsui, Tadao Natsuume
  • Patent number: 5585989
    Abstract: Using a thermoplastic norbornene type plastic as a material for the magnetic disc substrate, a magnetic disc substrate having a small deformation and a high modulus of elasticity is prepared. By optimizing the thickness of the substrate, the resonance frequency of the magnetic disc can be elevated to a level higher than the servo band. As a result, a magnetic disc substrate can form a servo mark having a high positional precision, and can carry out tracking with high precision.
    Type: Grant
    Filed: November 23, 1994
    Date of Patent: December 17, 1996
    Assignees: Sony Corporation, Nippon Zeon Co., Ltd.
    Inventors: Miyuki Kuromiya, Hiroshi Takino, Masayoshi Oshima, Teiji Kohara
  • Patent number: 5580934
    Abstract: There are disclosed a polycyclic norbornene or its derivative hydrogenated copolymer which containsa repeating unit represented by the following formula [I] or the alkyl-substituted derivative thereof (A),a repeating unit represented by the following formula [II] or the alkyl-substituted derivative thereof (B) and, as desired,5-85% by mole of at least one repeating unit (C) selected from a repeating unit represented by the following formula [III], the alkyl-substituted derivative thereof, a repeating unit represented by the following formula [IV], the alkyl-substituted derivative and the alkylidene-substituted derivative thereof, and a process for producing the polycyclic norbornene or its derivative ring-opening hydrogenated copolymer ##STR1## wherein ------ represents either a single bond or a double bond.
    Type: Grant
    Filed: June 7, 1990
    Date of Patent: December 3, 1996
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Yoshikatsu Nishi, Masayoshi Oshima, Teiji Kohara, Tadao Natsuume