Patents by Inventor Toshimasa Tokuda

Toshimasa Tokuda 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: 7317067
    Abstract: An object of the present invention is to provide a polycarbonate copolymer having excellent heat resistance and dimensional stability and heat resistant parts comprising the copolymer and suitable for use in various applications. The present invention is a polycarbonate copolymer comprising 5 to 95 mol % of recurring unit (component a) represented by the following general formula (I): and 95 to 5 mol % of recurring unit (component b) represented by the following general formula (II): (wherein Ra to Rd are each independently a hydrogen atom, a hydrocarbon group which may contain an aromatic group having 1 to 9 carbon atoms or a halogen atom, and W is a single bond, a hydrocarbon group which may contain an aromatic group having 1 to 20 carbon atoms or an O, SO, SO2, CO or COO group), and various heat resistant parts comprising the copolymer.
    Type: Grant
    Filed: March 24, 2003
    Date of Patent: January 8, 2008
    Assignee: Teijin Chemicals
    Inventors: Koki Ikeda, Toshimasa Tokuda, Yoshimasa Okamoto, Masato Ando
  • Patent number: 7244804
    Abstract: There are provided a polycarbonate copolymer (A) which has excellent light resistance and heat resistance and comprises an aromatic dihydroxy component comprising 5 to 95 mol % of fluorene-skeleton-containing dihydroxy compound (1) having a specific structure and 95 to 5 mol % of ordinary bisphenol type dihydroxy compound (2), the content of fluorene-9-one in the copolymer being not higher than 15 ppm; and a polycarbonate composition comprising 0.01 to 5 parts by weight of ultraviolet absorber (B) based on 100 parts by weight of the copolymer (A), and the composition comprising the copolymer.
    Type: Grant
    Filed: November 13, 2003
    Date of Patent: July 17, 2007
    Assignee: Teijin Chemicals, Ltd.
    Inventors: Koki Ikeda, Toshimasa Tokuda, Hiroshi Shuto, Manabu Matsui, Toshiyuki Miyake, Kazushi Tando
  • Publication number: 20050119441
    Abstract: An object of the present invention is to provide a polycarbonate copolymer having excellent heat resistance and dimensional stability and heat resistant parts comprising the copolymer and suitable for use in various applications. The present invention is a polycarbonate copolymer comprising 5 to 95 mol % of recurring unit (component a) represented by the following general formula (I): and 95 to 5 mol % of recurring unit (component b) represented by the following general formula (II): (wherein Ra to Rd are each independently a hydrogen atom, a hydrocarbon group which may contain an aromatic group having 1 to 9 carbon atoms or a halogen atom, and W is a single bond, a hydrocarbon group which may contain an aromatic group having 1 to 20 carbon atoms or an O, SO, SO2, CO or COO group), and various heat resistant parts comprising the copolymer.
    Type: Application
    Filed: March 24, 2003
    Publication date: June 2, 2005
    Inventors: Koki Ikeda, Toshimasa Tokuda, Yoshimasa Okamoto, Masato Ando
  • Patent number: 6093784
    Abstract: An electrophotographic photoconductor is composed of an electroconductive support and a photoconductive layer formed thereon, which photoconductive layer includes a polycarbonate resin. Aromatic polycarbonate resins not only for the electrophotographic photoconductor, but also for the materials for liquid display panels, optical cards, optical discs, varieties of films having high transparency and heat resistance, deposited plastic reflecting mirrors, and lenses are disclosed.
    Type: Grant
    Filed: December 22, 1994
    Date of Patent: July 25, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Tamura, Tomoyuki Shimada, Tsutomu Nakajima, Masaomi Sasaki, Toshimasa Tokuda
  • Patent number: 5633060
    Abstract: An optical disk substrate formed substantially of an aromatic polycarbonate from an aromatic dihydroxy component containing at least 20 mol % of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,wherein:(A) the aromatic polycarbonate has a specific viscosity of 0.2 to 0.5,(B) the aromatic polycarbonate shows a water absorption percentage of 0.2 % by weight or less,(C) the aromatic polycarbonate has an oligomer content of 10 % or less, and(D) the number of undissolved particles having a diameter of 0.5 .mu.m or greater is 25,000 pieces or less per g of the polycarbonate resin, and the number of undissolved particles having a diameter of 1 .mu.m or greater is 500 pieces or less per g of the polycarbonate resin, and an optical disk from the above substrate.
    Type: Grant
    Filed: June 16, 1995
    Date of Patent: May 27, 1997
    Assignee: Teijin Chemicals, Ltd.
    Inventors: Toshimasa Tokuda, Kuniyuki Hayashi, Tatsumi Horie
  • Patent number: 5599897
    Abstract: There is provided an aromatic polycarbonate obtained by reacting a carbonate precursor substance with a dihydric phenol comprising mainly 2,2-bis(4-hydroxyphenol)-1,1,1,3,3,3-hexafluoropropane having specific characteristics. This aromatic polycarbonate has the following characteristics. That is, with respect to 5 wt % solution of the aromatic polycarbonate in methylene chloride, after being filtered through a filter having a pore diameter of 0.1 .mu.m, the light transmittance at 400 nm measured by using a quartz cell having an optical path length of 250 mm, is 85% or more in terms of light transmittance per cm of the polymer; and when 0.7 g of the aromatic polycarbonate is dissolved in 100 ml of methylene chloride, the specific viscosity of the thus obtained solution measured at 20.degree. C., is in the range of 0.160 to 0.418.
    Type: Grant
    Filed: May 25, 1995
    Date of Patent: February 4, 1997
    Assignees: Furukawa Electric Co., Ltd., Teijin Chemicals, Ltd.
    Inventors: Masaki Nishiguchi, Toshimasa Tokuda
  • Patent number: 5556904
    Abstract: There is provided an aromatic polycarbonate copolymer obtained by reacting a dihydric phenol component comprising mainly 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane and 9,9-bis(4-hydroxyphenyl)fluorene or 1,1-bis(4-hydroxyphenyl)-1-phenylethane in a prescribed ratio with a carbonate precursor substance. This aromatic polycarbonate copolymer has a specific viscosity in a limited range. The aromatic polycarbonate copolymer is excellent in optical characteristics, transparency, hydrolysis resistance, heat resistance, oxidation resistance, and heat stability and good in moldability, and is suitable for a plastic optical waveguide that is small in transmission loss and excellent in heat resistance.
    Type: Grant
    Filed: January 17, 1995
    Date of Patent: September 17, 1996
    Assignees: The Furukawa Electric Co. Ltd, Teijin Chemicals Ltd.
    Inventors: Masaki Nishiguchi, Toshimasa Tokuda
  • Patent number: 5496913
    Abstract: There is provided an aromatic polycarbonate obtained by reacting a carbonate precursor substance with a dihydric phenol comprising mainly 2,2-bis(4-hydroxyphenol)-1,1,1,3,3,3-hexafluoropropane having specific characteristics. This aromatic polycarbonate has the following characteristics. That is, with respect to 5 wt % solution of the aromatic polycarbonate in methylene chloride, after being filtered through a filter having a pore diameter of 0.1 .mu.m, the light transmittance at 400 nm measured by using a quartz cell having an optical path length of 250 mm, is 85% or more in terms of light transmittance per cm of the polymer; and when 0.7 g of the aromatic polycarbonate is dissolved in 100 ml of methylene chloride, the specific viscosity of the thus obtained solution measured at 20.degree. C., is in the range of 0.160 to 0.418.
    Type: Grant
    Filed: October 25, 1993
    Date of Patent: March 5, 1996
    Assignees: Furukawa Electric Co., Ltd, Teijin Chemicals Ltd.
    Inventors: Masaki Nishiguchi, Toshimasa Tokuda
  • Patent number: 5475786
    Abstract: There is provided an aromatic polycarbonate copolymer obtained by reacting a dihydric phenol component comprising mainly 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane and 9,9-bis(4-hydroxyphenyl)fluorene or 1,1-bis(4-hydroxyphenyl)-1-phenylethane in a prescribed ratio with a carbonate precursor substance. This aromatic polycarbonate copolymer has a specific viscosity in a limited range. The aromatic polycarbonate copolymer is excellent in optical characteristics, transparency, hydrolysis resistance, heat resistance, oxidation resistance, and heat stability and good in moldability, and is suitable for a plastic optical waveguide that is small in transmission loss and excellent in heat resistance.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: December 12, 1995
    Assignees: The Furukawa Electric Co., Ltd., Teijin Chemicals, Ltd.
    Inventors: Masaki Nishiguchi, Toshimasa Tokuda
  • Patent number: 5463013
    Abstract: A modified aromatic polycarbonate resin containing at least one substituted phenyloxy group of the formula (I) in an amount of at least 5 mol % of the total amount of terminals, ##STR1## wherein: X is a halogen atom or a monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms,p is an integer of 0 to 4, and ##STR2## The present invention provide a modified aromatic polycarbonate resin of which the melt fluidity and electric properties are improved without impairing the excellent properties inherent to a polycarbonate resin such as transparency, heat resistance and dimensional stability.
    Type: Grant
    Filed: April 26, 1994
    Date of Patent: October 31, 1995
    Assignee: Teijin Chemicals, Ltd.
    Inventors: Toshimasa Tokuda, Ikkoh Furukawa, Masayoshi Miyauchi
  • Patent number: 5409975
    Abstract: There is provided an aromatic polycarbonate copolymer obtained by reacting a dihydric phenol component comprising mainly 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane and 9,9-bis(4-hydroxyphenyl)fluorene or 1,1-bis(4-hydroxyphenyl)-1-phenylethane in a prescribed ratio with a carbonate precursor substance. This aromatic polycarbonate copolymer has a specific viscosity in a limited range. The aromatic polycarbonate copolymer is excellent in optical characteristics, transparency, hydrolysis resistance, heat resistance, oxidation resistance, and heat stability and good in moldability, and is suitable for a plastic optical waveguide that is small in transmission loss and excellent in heat resistance.
    Type: Grant
    Filed: October 25, 1993
    Date of Patent: April 25, 1995
    Assignees: The Furukawa Electric Co., Ltd., Teijin Chemicals, Ltd.
    Inventors: Masaki Nishiguichi, Toshimasa Tokuda
  • Patent number: 5352759
    Abstract: There is provided a polycarbonate lens having improved transmittance of light with a wavelength of 400 nm. This lens is made of a polycarbonate derived from 1,1-bis(4-hydroxyphenyl)-1-phenylethane, specific viscosity found from a solution of 0.7 g of said polycarbonate in 100 ml of methylene chloride being 0.176 to 0.295, and transmittance of light with a wavelength of 400 nm passing through a 3 mm thick member molded from said polycarbonate being 80% or more.
    Type: Grant
    Filed: February 4, 1993
    Date of Patent: October 4, 1994
    Assignee: Teijin Chemicals, Ltd.
    Inventor: Toshimasa Tokuda
  • Patent number: 4316838
    Abstract: A resin composition having an excellent fire retarding effect is provided which comprises (1) a polycarbonate and (2) as a fire retardant, at least one member of the group consisting of (A) a metal salt of a sulfuric ester of an alcohol, (B) an ether derived from an alkyl alcohol and a phenol and having a metal sulfonate group bonded to the carbon atom of the alkyl group and (C) a polycarbonate having at least one alkali metal sulfonate group bonded to the terminals through alkyl. Addition of a mixture of the component (A) and at least one specified halogen-containing organic compound as the fire retardant to the polycarbonate (1) affords a resin composition having a greater fire retardant effect.
    Type: Grant
    Filed: March 19, 1980
    Date of Patent: February 23, 1982
    Assignee: Teijin Chemicals Ltd.
    Inventor: Toshimasa Tokuda
  • Patent number: 4285855
    Abstract: A resin composition having an excellent fire retarding effect is provided which comprises (1) a polycarbonate and (2) as a fire retardant, at least one member of the group consisting of (A) a metal salt of a sulfuric ester of an alcohol, (B) an ether derived from an alkyl alcohol and a phenol and having a metal sulfonate group bonded to the carbon atom of the alkyl group and (C) a polycarbonate having at least one alkali metal sulfonate group bonded to the terminals through alkyl. Addition of a mixture of the component (A) and at least one specified halogen-containing organic compound as the fire retardant to the polycarbonate (1) affords a resin composition having a greater fire retardant effect.
    Type: Grant
    Filed: March 19, 1980
    Date of Patent: August 25, 1981
    Assignee: Teijin Chemicals Ltd.
    Inventor: Toshimasa Tokuda
  • Patent number: 4222910
    Abstract: A resin composition having an excellent fire retarding effect is provided which comprises (1) a polycarbonate and (2) as a fire retardant, at least one member of the group consisting of (A) a metal salt of a sulfuric ester of an alcohol, (B) an ether derived from an alkyl alcohol and a phenol and having a metal sulfonate group bonded to the carbon atom of the alkyl group and (C) a polycarbonate having at least one alkali metal sulfonate group bonded to the terminals through alkyl. Addition of a mixture of the component (A) and at least one specified halogen-containing organic compound as the fire retardant to the polycarbonate (1) affords a resin composition having a greater fire retardant effect.
    Type: Grant
    Filed: November 7, 1978
    Date of Patent: September 16, 1980
    Assignee: Teijin Chemicals, Ltd.
    Inventor: Toshimasa Tokuda