Patents by Inventor Takao Tayama

Takao Tayama 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: 7511114
    Abstract: Colored aromatic polycarbonate resin compositions are prepared by dispersing a colorant (b) selected from phthalocyanine-based compounds, anthraquinone-based compounds and ultramarine blue in a polyalkyleneglycol compound (c) having a number-average molecular weight of 62 to 4000 of formula (2): HO—[—CHR1—CHR2—]m—OH??(2) where R1, R2, R3 and R4 are independently hydrogen atoms or alkyl groups, and m is not less than 1. The dispersion is added to an aromatic polycarbonate resin (a) kept in a molten state which has a viscosity-average molecular weight of not less than 16000 and contains a branched constitutional unit of formula (1): in an amount of 0.3 to 0.95 mol % where X is a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, or a divalent connecting group —O—, —S—, —CO—, —SO— and —SO2—.
    Type: Grant
    Filed: November 28, 2006
    Date of Patent: March 31, 2009
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Masaaki Miyamoto, Takao Tayama, Kiyoji Kuma, Eiji Fujimoto
  • Patent number: 7271235
    Abstract: It is to provide a branched aromatic polycarbonate excellent in hue and excellent in melt properties such as melt strength.
    Type: Grant
    Filed: August 5, 2003
    Date of Patent: September 18, 2007
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Masaaki Miyamoto, Takao Tayama
  • Publication number: 20070129471
    Abstract: There is provided an aromatic polycarbonate resin composition which is free from unevenness of color and exhibits a good heat resistance and a good hydrolysis resistance. The aromatic polycarbonate resin composition of the present invention comprises: (a) 100 parts by weight of an aromatic polycarbonate resin having a viscosity-average molecular weight of not less than 16000 and containing a branched constitutional unit in an amount of 0.3 to 0.95 mol % on the basis of a constitutional unit represented by the general formula (1): (wherein X is a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, or a divalent connecting group selected from the group consisting of —O—, —S—, —CO—, —SO— and —SO2—); (b) 0.00001 to 0.
    Type: Application
    Filed: November 28, 2006
    Publication date: June 7, 2007
    Applicant: MITSUBISHI CHEMICAL CORPORATION
    Inventors: Masaaki Miyamoto, Takao Tayama, Kiyoji Kuma, Eiji Fujimoto
  • Patent number: 7084233
    Abstract: A subject for the invention is to provide a branched aromatic polycarbonate which is excellent in hue and in melt characteristics such as melt strength. The invention provides a branched aromatic polycarbonate having a viscosity-average molecular weight of 16,000 or higher obtained by the transesterification method, characterized in that the ratio of the weight-average molecular weight (Mw) to number-average molecular weight (Mn) as measured by gel permeation chromatography and calculated for standard polystyrene (Mw/Mn) is in the range of from 2.8 to 4.5 and that the proportion of the number of moles of all structural units yielded by a rearrangement reaction in the course of melt polymerization reaction to 1 mol of structural units having the framework of an aromatic dihydroxy compound used as a starting material is higher than 0.3 mol % and not higher than 0.95 mol.
    Type: Grant
    Filed: March 31, 2004
    Date of Patent: August 1, 2006
    Assignees: Mitsubishi Chemical Corporation, Mitsubishi Engineering-Plastics Corporation
    Inventors: Masaaki Miyamoto, Takao Tayama, Hiroshi Nakano
  • Patent number: 6884864
    Abstract: The present invention relates to a polycarbonate which can be obtained by a melting method and whose loss angle ? and complex viscosity ?* (Pa·s) measured under the conditions of 250° C. and an angular velocity of 10 rad/s satisfy the following relation (1): 2,500?Tan ?/(?*)?0.
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: April 26, 2005
    Assignee: Mitsubishi Engineering-Plastics Corporation
    Inventors: Tatsuya Masuki, Hiroshi Yoshioka, Takao Tayama, Masaaki Miyamoto
  • Patent number: 6875491
    Abstract: A polycarbonate composition excellent in both antistatic property and coloring matter coatability containing (a) a polycarbonate obtained by an ester exchange process, and (b) a compound having a molecular weight of from 300 to 8,000 and having any of ester bond, carbonate bond, amide bond and urethane bond in its molecule and an aromatic hydrocarbon group substituted by at least one alkyl group at the molecular end thereof, a write once read many optical disc substrate and a write once read many optical disc using the same and a process for the production of a write once read many optical disc are described.
    Type: Grant
    Filed: October 22, 2002
    Date of Patent: April 5, 2005
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Masaaki Miyamoto, Takao Tayama, Ryuji Uchimura, Toshimitsu Inoue, Shigeo Higashi, Masaya Ueda
  • Publication number: 20040260049
    Abstract: A subject for the invention is to provide a branched aromatic polycarbonate which is excellent in hue and in melt characteristics such as melt strength.
    Type: Application
    Filed: March 31, 2004
    Publication date: December 23, 2004
    Applicants: Mitsubishi Chemical Corporation, Mitsubishi Engineering-Plastics Corporation
    Inventors: Masaaki Miyamoto, Takao Tayama, Hiroshi Nakano
  • Patent number: 6730725
    Abstract: The present invention relates to a polycarbonate which can be obtained by a melting method and has a viscosity-average molecular weight of 16000 to 27000, and whose loss angle &dgr; and complex viscosity &eegr;* (Pa·s) measured under the conditions of 250° C. and an angular velocity of 10 rad/s satisfy the following relation (1): 4,700≦Tan &dgr;/(&eegr;*)−0.
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: May 4, 2004
    Assignee: Mitsubishi Engineering-Plastics Corp.
    Inventors: Tatsuya Masuki, Hiroshi Yoshioka, Takao Tayama, Masaaki Miyamoto
  • Publication number: 20040024168
    Abstract: It is to provide a branched aromatic polycarbonate excellent in hue and excellent in melt properties such as melt strength.
    Type: Application
    Filed: August 5, 2003
    Publication date: February 5, 2004
    Applicant: MITSUBISHI CHEMICAL CORPORATION
    Inventors: Masaaki Miyamoto, Takao Tayama
  • Publication number: 20030153720
    Abstract: A polycarbonate composition excellent in both antistatic property and coloring matter coatability containing (a) a polycarbonate obtained by an ester exchange process, and (b) a compound having a molecular weight of from 300 to 8,000 and having any of ester bond, carbonate bond, amide bond and urethane bond in its molecule and an aromatic hydrocarbon group substituted by at least one alkyl group at the molecular end thereof, a write once read many optical disc substrate and a write once read many optical disc using the same and a process for the production of a write once read many optical disc are described.
    Type: Application
    Filed: October 22, 2002
    Publication date: August 14, 2003
    Applicant: MITSUBISHI CHEMICAL CORPORATION
    Inventors: Masaaki Miyamoto, Takao Tayama, Ryuji Uchimura, Toshimitsu Inoue, Shigeo Higashi, Masaya Ueda
  • Publication number: 20030023024
    Abstract: The present invention relates to a polycarbonate which can be obtained by a melting method and whose loss angle &dgr; and complex viscosity &eegr;* (Pa·s) measured under the conditions of 250° C.
    Type: Application
    Filed: April 10, 2002
    Publication date: January 30, 2003
    Applicant: Mitsubishi Engineering-Plastics Corporation
    Inventors: Tatsuya Masuki, Hiroshi Yoshioka, Takao Tayama, Masaaki Miyamoto
  • Publication number: 20020193470
    Abstract: The present invention relates to a polycarbonate which can be obtained by a melting method and has a viscosity-average molecular weight of 16000 to 27000, and whose loss angle &dgr; and complex viscosity &eegr;* (Pa·s) measured under the conditions of 250° C.
    Type: Application
    Filed: April 10, 2002
    Publication date: December 19, 2002
    Inventors: Tatsuya Masuki, Hiroshi Yoshioka, Takao Tayama, Masaaki Miyamoto
  • Patent number: 5519106
    Abstract: A process for preparing an aromatic polycarbonate resin from an aromatic dihydroxy compound and a carbonate diester by transesterification in the presence of a transesterification catalyst comprising; reacting a purified carbonate diester with an aromatic dihydroxy compound in the presence of a transesterification catalyst to form a polycarbonate prepolymer; said carbonate diester containing benzophenone and benzoate ester derivatives having a molecular weight of less than 1,000, each in an amount of 100 ppm or less, said polycarbonate prepolymer having a viscosity average molecular weight of 5,000 to 20,000 at a temperature of 140.degree. to 280.degree. C., the reaction pressure being from 0.1 Torr to normal pressure; polymerizing said prepolymer at a temperature of 240.degree. to 350.degree. C. in a lateral, bi-axial, self-cleaning reactor to obtain an aromatic polycarbonate resin having a viscosity average molecular weight of 15,000 to 60,000.
    Type: Grant
    Filed: January 17, 1995
    Date of Patent: May 21, 1996
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Masahiro Nukui, Takao Tayama, Takeshi Kashiwagi, Masatoshi Kimura, Hidekazu Shoji
  • Patent number: 5455324
    Abstract: Disclosed herein is an aromatic polycarbonate resin containing benzophenone and benzoate ester derivatives which have a molecular weight less than 1,000, each in an amount of 100 ppm or less. Also disclosed is a process for preparing an aromatic polycarbonate resin from an aromatic dihydroxy compound and a carbonate diester in which the benzophenone derivative content is 100 ppm or less by transesterification, comprising preparing a polycarbonate prepolymer having a viscosity average molecular weight of 5,000 to 20,000 using an iminocarboxylic acid or salt thereof as a transesterification catalyst and polymerizing the prepolymer in an extruder.The aromatic polycarbonate is colorless and transparent and is suitable for extrusion molding.
    Type: Grant
    Filed: August 25, 1993
    Date of Patent: October 3, 1995
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Masahiro Nukui, Takao Tayama, Takeshi Kashiwagi, Masatoshi Kimura, Hidekazu Shoji