Patents by Inventor Norifumi Maeda

Norifumi Maeda 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).

  • Publication number: 20140024793
    Abstract: Provided is a polyester production process which provides the polyester with a suitable molecular weight capable of enduring various mold processings and which can inhibit the polymer from being colored due to side reactions in synthesis. The above polyester production process comprises: an esterification step of carrying out an esterification reaction of ethylene glycol and 2,5-furandicarboxylic acid to form an oligomer and a condensation polymerization step of carrying out a condensation polymerization reaction of the oligomer to produce polyester, wherein the esterification reaction is carried out at 200 to 250° C.
    Type: Application
    Filed: July 19, 2013
    Publication date: January 23, 2014
    Inventors: Toshiaki MATSUO, Masayuki KAMIKAWA, Takeyuki KONDO, Norifumi MAEDA
  • Patent number: 7204962
    Abstract: Polybutylene terephthalate having good heat stability and excellent hydrolysis resistance is continuously produced in a series of a first reactor for reacting an aromatic dicarboxylic acid comprising terephthalic acid as a main ingredient or a derivative thereof with a glycol comprising 1,4-butanediol as a main ingredient, thereby producing an oligomer with an average degree of polymerization of 2.2 to 5, a second reactor for polycondensating the oligomer from the first reactor, thereby preparing a low polymerization product with an average degree of polymerization of 25 to 40, and a third reactor for further polycondensating the low polymerization product from the second reactor, thereby producing a high molecular weight polyester with an average degree of polymerization of 70 to 130, or followed by a fourth reactor for further polycondensing the polyester from the third reactor to an average degree of polymerization of 150 to 200, thereby producing a high molecular weight polyester.
    Type: Grant
    Filed: February 23, 2001
    Date of Patent: April 17, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Hidekazu Nakamoto, Susumu Harada, Norifumi Maeda, Shuji Yamaguchi
  • Patent number: 7179433
    Abstract: An apparatus for continuously producing polybutylene terephthalate, which comprises a first reactor for reacting an aromatic dicarboxylic acid with a glycol, thereby producing an oligomer, a second reactor for polycondensating the oligomer, thereby preparing a low polymerization product, and a third reactor for further polycondensating the low polymerization product, thereby producing a high molecular weight polyester, where the second reactor is a vertical, cylindrical polymerization vessel having a plurality of concentrical partitioned reaction compartments therein, each of the reaction compartments being provided with stirring blades and a heater, and an outlet for volatile matters being provided at the upper part of the vessel. The second reactor contributes to efficient and continuous production of polybutylene terephthalate having a good quality.
    Type: Grant
    Filed: February 26, 2004
    Date of Patent: February 20, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Shuji Yamaguchi, Hidekazu Nakamoto, Susumu Harada, Norifumi Maeda
  • Patent number: 7057007
    Abstract: Polybutylene terephthalate having good heat stability and excellent hydrolysis resistance is continuously produced in a series of a first reactor for reacting an aromatic dicarboxylic acid comprising terephthalic acid as a main ingredient or a derivative thereof with a glycol comprising 1,4-butanediol as a main ingredient, a second reactor for polycondensating the oligomer from the first reactor, and a third reactor for further polycondensating the low polymerization product from the second reactor, or followed by a fourth reactor for further polycondensing the polyester from the third reactor. Another third reactor or a plurality of third reactors can be provided in parallel to the third reactor.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: June 6, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Hidekazu Nakamoto, Susumu Harada, Norifumi Maeda, Shuji Yamaguchi
  • Publication number: 20040166039
    Abstract: An apparatus for continuously producing polybutylene terephthalate, which comprises a first reactor for reacting an aromatic dicarboxylic acid with a glycol, thereby producing an oligomer, a second reactor for polycondensating the oligomer, thereby preparing a low polymerization product, and a third reactor for further polycondensating the low polymerization product, thereby producing a high molecular weight polyester, where the second reactor is a vertical, cylindrical polymerization vessel having a plurality of concentrical partitioned reaction compartments therein, each of the reaction compartments being provided with stirring blades and a heater, and an outlet for volatile matters being provided at the upper part of the vessel. The second reactor contributes to efficient and continuous production of polybutylene terephthalate having a good quality.
    Type: Application
    Filed: February 26, 2004
    Publication date: August 26, 2004
    Inventors: Shuji Yamaguchi, Hidekazu Nakamoto, Susumu Harada, Norifumi Maeda
  • Patent number: 6723826
    Abstract: An apparatus for continuously producing polybutylene terephthalate, which comprises a first reactor for reacting an aromatic dicarboxylic acid with a glycol, thereby producing an oligomer, a second reactor for polycondensating the oligomer, thereby preparing a low polymerization product, and a third reactor for further polycondensating the low polymerization product, thereby producing a high molecular weight polyester, where the second reactor is a vertical, cylindrical polymerization vessel having a plurality of concentrical partitioned reaction compartments therein, each of the reaction compartments being provided with stirring blades and a heater, and an outlet for volatile matters being provided at the upper part of the vessel. The second reactor contributes to efficient and continuous production of polybutylene terephthalate having a good quality.
    Type: Grant
    Filed: May 28, 2003
    Date of Patent: April 20, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Shuji Yamaguchi, Hidekazu Nakamoto, Susumu Harada, Norifumi Maeda
  • Publication number: 20030208030
    Abstract: An apparatus for continuously producing polybutylene terephthalate, which comprises a first reactor for reacting an aromatic dicarboxylic acid with a glycol, thereby producing an oligomer, a second reactor for polycondensating the oligomer, thereby preparing a low polymerization product, and a third reactor for further polycondensating the low polymerization product, thereby producing a high molecular weight polyester, where the second reactor is a vertical, cylindrical polymerization vessel having a plurality of concentrical partitioned reaction compartments therein, each of the reaction compartments being provided with stirring blades and a heater, and an outlet for volatile matters being provided at the upper part of the vessel. The second reactor contributes to efficient and continuous production of polybutylene terephthalate having a good quality.
    Type: Application
    Filed: May 28, 2003
    Publication date: November 6, 2003
    Inventors: Shuji Yamaguchi, Hidekazu Nakamoto, Susumu Harada, Norifumi Maeda
  • Patent number: 6590062
    Abstract: An apparatus for continuously producing polybutylene terephthalate, which comprises a first reactor for reacting an aromatic dicarboxylic acid with a glycol, thereby producing an oligomer, a second reactor for polycondensating the oligomer, thereby preparing a low polymerization product, and a third reactor for further polycondensating the low polymerization product, thereby producing a high molecular weight polyester, where the second reactor is a vertical, cylindrical polymerization vessel having a plurality of concentrical partitioned reaction compartments therein, each of the reaction compartments being provided with stirring blades and a heater, and an outlet for volatile matters being provided at the upper part of the vessel. The second reactor contributes to efficient and continuous production of polybutylene terephthalate having a good quality.
    Type: Grant
    Filed: September 23, 2002
    Date of Patent: July 8, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Shuji Yamaguchi, Hidekazu Nakamoto, Susumu Harada, Norifumi Maeda
  • Publication number: 20030045671
    Abstract: An apparatus for continuously producing polybutylene terephthalate, which comprises a first reactor for reacting an aromatic dicarboxylic acid with a glycol, thereby producing an oligomer, a second reactor for polycondensating the oligomer, thereby preparing a low polymerization product, and a third reactor for further polycondensating the low polymerization product, thereby producing a high molecular weight polyester, where the second reactor is a vertical, cylindrical polymerization vessel having a plurality of concentrical partitioned reaction compartments therein, each of the reaction compartments being provided with stirring blades and a heater, and an outlet for volatile matters being provided at the upper part of the vessel. The second reactor contributes to efficient and continuous production of polybutylene terephthalate having a good quality.
    Type: Application
    Filed: September 23, 2002
    Publication date: March 6, 2003
    Inventors: Shuji Yamaguchi, Hidekazu Nakamoto, Susumu Harada, Norifumi Maeda
  • Patent number: 6458916
    Abstract: An apparatus for continuously producing polybutylene terephthalate, which comprises a first reactor for reacting an aromatic dicarboxylic acid with a glycol, thereby producing an oligomer, a second reactor for polycondensating the oligomer, thereby preparing a low polymerization product, and a third reactor for further polycondensating the low polymerization product, thereby producing a high molecular weight polyester, where the second reactor is a vertical, cylindrical polymerization vessel having a plurality of concentrical partitioned reaction compartments therein, each of the reaction compartments being provided with stirring blades and a heater, and an outlet for volatile matters being provided at the upper part of the vessel. The second reactor contributes to efficient and continuous production of polybutylene terephthalate having a good quality.
    Type: Grant
    Filed: August 29, 2001
    Date of Patent: October 1, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Shuji Yamaguchi, Hidekazu Nakamoto, Susumu Harada, Norifumi Maeda
  • Publication number: 20020128399
    Abstract: Polybutylene terephthalate having good heat stability and excellent hydrolysis resistance is continuously produced in a series of a first reactor for reacting an aromatic dicarboxylic acid comprising terephthalic acid as a main ingredient or a derivative thereof with a glycol comprising 1,4-butanediol as a main ingredient, thereby producing an oligomer with an average degree of polymerization of 2.2 to 5, a second reactor for polycondensating the oligomer from the first reactor, thereby preparing a low polymerization product with an average degree of polymerization of 25 to 40, and a third reactor for further polycondensating the low polymerization product from the second reactor, thereby producing a high molecular weight polyester with an average degree of polymerization of 70 to 130, or followed by a fourth reactor for further polycondensing the polyester from the third reactor to an average degree of polymerization of 150 to 200, thereby producing a high molecular weight polyester.
    Type: Application
    Filed: March 8, 2002
    Publication date: September 12, 2002
    Inventors: Hidekazu Nakamoto, Susumu Harada, Norifumi Maeda, Shuji Yamaguchi
  • Patent number: 6359106
    Abstract: Polybutylene terephthalate having good heat stability and excellent hydrolysis resistance is continuously produced in a series of a first reactor for reacting an aromatic dicarboxylic acid comprising terephthalic acid as a main ingredient or a derivative thereof with a glycol comprising 1,4-butanediol as a main ingredient, thereby producing an oligomer with an average degree of polymerization of 2.2 to 5, a second reactor for polycondensating the oligomer from the first reactor, thereby preparing a low polymerization product with an average degree of polymerization of 25 to 40, and a third reactor for further polycondensating the low polymerization product from the second reactor, thereby producing a high molecular weight polyester with an average degree of polymerization of 70 to 130, or followed by a fourth reactor for further polycondensing the polyester from the third reactor to an average degree of polymerization of 150 to 200, thereby producing a high molecular weight polyester.
    Type: Grant
    Filed: August 22, 2000
    Date of Patent: March 19, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Hidekazu Nakamoto, Susumu Harada, Norifumi Maeda, Shuji Yamaguchi
  • Publication number: 20010031231
    Abstract: Polybutylene terephthalate having good heat stability and excellent hydrolysis resistance is continuously produced in a series of a first reactor for reacting an aromatic dicarboxylic acid comprising terephthalic acid as a main ingredient or a derivative thereof with a glycol comprising 1,4-butanediol as a main ingredient, thereby producing an oligomer with an average degree of polymerization of 2.2 to 5, a second reactor for polycondensating the oligomer from the first reactor, thereby preparing a low polymerization product with an average degree of polymerization of 25 to 40, and a third reactor for further polycondensating the low polymerization product from the second reactor, thereby producing a high molecular weight polyester with an average degree of polymerization of 70 to 130, or followed by a fourth reactor for further polycondensing the polyester from the third reactor to an average degree of polymerization of 150 to 200, thereby producing a high molecular weight polyester.
    Type: Application
    Filed: February 23, 2001
    Publication date: October 18, 2001
    Inventors: Hidekazu Nakamoto, Susumu Harada, Norifumi Maeda, Shuji Yamaguchi