Patents by Inventor Kohkoku Ri

Kohkoku Ri 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: 7071285
    Abstract: An electrophotographic photoconductor has an electroconductive support, and a photoconductive layer formed thereon containing as an effective component an aromatic polycarbonate resin having a structural unit of formula (2) and a structural unit with charge transporting properties, each of the structural units being contained in an amount of 5 wt. % or more of the total weight of the polycarbonate resin. There is disclosed an aromatic polycarbonate resin having a structural unit of formula (1) and the structural unit of formula (2), with the relationship between the composition ratios being 0<k/(k+j)<1 when the composition ratio of the structural unit (1) is k and that of the structural unit (2) is j, or an aromatic polycarbonate resin having a repeat unit of formula (3). The formulas (1) to (3) are specified in the specification.
    Type: Grant
    Filed: July 1, 2004
    Date of Patent: July 4, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichi Kawamura, Masaomi Sasaki, Kazukiyo Nagai, Kohkoku Ri, Susumu Suzuka, Katsuhiro Morooka
  • Patent number: 6919419
    Abstract: An aromatic block polycarbonate resin is prepared by polymerizing a diphenol compound of formula (2) or (4), a diol compound of formula (1) or (5), and a halogenated carbonyl compound. The diphenol compound of formula (4) is produced by polymerizing the diphenol compound of formula (2) and a halogenated carbonyl compound by solution or interfacial polymerization. An electrophotographic photoconductor has an electroconductive support and a photoconductive layer formed thereon containing the above-mentioned aromatic block polycarbonate resin. An electrophotographic image forming method or apparatus employs the above-mentioned photoconductor. A process cartridge holds therein the photoconductor and at least one of the electrophotographic image forming units.
    Type: Grant
    Filed: January 22, 2003
    Date of Patent: July 19, 2005
    Assignees: Ricoh Company Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Kohkoku Ri, Masaomi Sasaki, Kazukiyo Nagai, Shinichi Kawamura, Susumu Suzuka, Katsuhiro Morooka
  • Publication number: 20050003287
    Abstract: An electrophotographic photoconductor has an electroconductive support, and a photoconductive layer formed thereon containing as an effective component an aromatic polycarbonate resin having a structural unit of formula (2) and a structural unit with charge transporting properties, each of the structural units being contained in an amount of 5 wt. % or more of the total weight of the polycarbonate resin. There is disclosed an aromatic polycarbonate resin having a structural unit of formula (1) and the structural unit of formula (2), with the relationship between the composition ratios being 0<k/(k+j)<1 when the composition ratio of the structural unit (1) is k and that of the structural unit (2) is j, or an aromatic polycarbonate resin having a repeat unit of formula (3). The formulas (1) to (3) are specified in the specification.
    Type: Application
    Filed: July 1, 2004
    Publication date: January 6, 2005
    Applicant: RICOH COMPANY, LTD.
    Inventors: Shinichi Kawamura, Masaomi Sasaki, Kazukiyo Nagai, Kohkoku Ri, Susumu Suzuka, Katsuhiro Morooka
  • Patent number: 6790571
    Abstract: An electrophotographic photoconductor has an electroconductive support, and a photoconductive layer formed thereon containing as an effective component an aromatic polycarbonate resin having a structural unit of formula (2) and a structural unit with charge transporting properties, each of the structural units being contained in an amount of 5 wt. % or more of the total weight of the polycarbonate resin. There is disclosed an aromatic polycarbonate resin having a structural unit of formula (1) and the structural unit of formula (2), with the relationship between the composition ratios being 0<k/(k+j)<1 when the composition ratio of the structural unit (1) is k and that of the structural unit (2) is j, or an aromatic polycarbonate resin having a repeat unit of formula (3). The formulas (1) to (3) are specified in the specification.
    Type: Grant
    Filed: January 22, 2002
    Date of Patent: September 14, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichi Kawamura, Masaomi Sasaki, Kazukiyo Nagai, Kohkoku Ri, Susumu Suzuka, Katsuhiro Morooka
  • Publication number: 20040002574
    Abstract: An aromatic block polycarbonate resin is prepared by polymerizing a diphenol compound of formula (2) or (4), a diol compound of formula (1) or (5), and a halogenated carbonyl compound. The diphenol compound of formula (4) is produced by polymerizing the diphenol compound of formula (2) and a halogenated carbonyl compound by solution or interfacial polymerization. An electrophotographic photoconductor has an electroconductive support and a photoconductive layer formed thereon containing the above-mentioned aromatic block polycarbonate resin. An electrophotographic image forming method or apparatus employs the above-mentioned photoconductor. A process cartridge holds therein the photoconductor and at least one of the electrophotographic image forming units.
    Type: Application
    Filed: January 22, 2003
    Publication date: January 1, 2004
    Applicants: RICOH COMPANY, LTD., Hodogaya Chemical Co., Ltd.
    Inventors: Kohkoku Ri, Masaomi Sasaki, Kazukiyo Nagai, Shinichi Kawamura, Susumu Suzuka, Katsuhiro Morooka
  • Patent number: 6664361
    Abstract: An electrophotographic photoconductor having an electroconductive support, and a photoconductive layer formed thereon and containing an aromatic polycarbonate resin having a structural unit of formula (3) shown in the specification. The polycarbonate resin is produced from a diphenol compound of the formula (1) shown in the specification.
    Type: Grant
    Filed: December 4, 2001
    Date of Patent: December 16, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaomi Sasaki, Shinichi Kawamura, Kazukiyo Nagai, Kohkoku Ri, Katsuhiro Morooka, Susumu Suzuka
  • Patent number: 6576386
    Abstract: An aromatic block polycarbonate resin is prepared by polymerizing a diphenol compound of formula (2) or (4), a dial compound of formula (1) or (5), and a halogenated carbonyl compound. The diphenol compound of formula (4) is produced by polymerizing the diphenol compound of formula (2) and a halogenated carbonyl compound by solution or interfacial polymerization. An electrophotographic photoconductor has an electroconductive support and a photoconductive layer formed thereon containing the above-mentioned aromatic block polycarbonate resin. An electrophotographic image forming method or apparatus employs the above-mentioned photoconductor. A process cartridge holds therein the photoconductor and at least one of the electrophotographic image forming units.
    Type: Grant
    Filed: August 9, 2000
    Date of Patent: June 10, 2003
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical., Ltd.
    Inventors: Kohkoku Ri, Masaomi Sasaki, Kazukiyo Nagai, Shinichi Kawamura, Susumu Suzuka, Katsuhiro Morooka
  • Patent number: 6486293
    Abstract: A method of producing an aromatic polycarbonate resin includes the step of carrying out solution polymerization of a diphenol compound having a triarylamine structure with a diol compound of formula (I): wherein R1 and R2 are each independently a substituted or unsubstituted alkyl croup, a substituted or unsubstituted aryl group, or a halogen atom; a and b are each independently an integer of 0 to 4: and Y is —COO— or in which Z is a substituted or unsubstituted bivalent aliphatic group or a substituted or unsubstituted arylene group. In addition, an electrophotographic photoconductor has an electroconductive support, and a photoconductive layer formed thereon containing as an effective component the above-mentioned aromatic polycarbonate resin prepared by the solution polymerization.
    Type: Grant
    Filed: October 19, 2000
    Date of Patent: November 26, 2002
    Assignee: Ricoh Company, Ltd.
    Inventors: Kohkoku Ri, Masaomi Sasaki, Kazukiyo Nagai, Shinichi Kawamura, Susumu Suzuka, Katsuhiro Morooka
  • Publication number: 20020147278
    Abstract: An electrophotographic photoconductor having an electroconductive support, and a photoconductive layer formed thereon and containing an aromatic polycarbonate resin having a structural unit of formula (3) shown in the specification. The polycarbonate resin is produced from a diphenol compound of the formula (1) shown in the specification.
    Type: Application
    Filed: December 4, 2001
    Publication date: October 10, 2002
    Inventors: Masaomi Sasaki, Shinichi Kawamura, Kazukiyo Nagai, Kohkoku Ri, Katsuhiro Morooka, Susumu Suzuka
  • Patent number: 6444387
    Abstract: An image bearing material including a matrix resin and, within the matrix resin, a core/shell graft copolymer including a core including one or more polymers and a shell including a graft polymer which has a linear chain connected with the core and which is formed from one or more monomers. The image bearing material is preferably used for a surface layer of an electrophotographic photoreceptor, an intermediate transfer medium, and the like image bearing members to improve the abrasion resistance thereof.
    Type: Grant
    Filed: December 22, 2000
    Date of Patent: September 3, 2002
    Assignee: Ricoh Company Limited
    Inventors: Kohkoku Ri, Masaomi Sasaki, Kazukiyo Nagai, Shinichi Kawamura
  • Publication number: 20020098430
    Abstract: An electrophotographic photoconductor has an electroconductive support, and a photoconductive layer formed thereon containing as an effective component an aromatic polycarbonate resin having a structural unit of formula (2) and a structural unit with charge transporting properties, each of the structural units being contained in an amount of 5 wt. % or more of the total weight of the polycarbonate resin. There is disclosed an aromatic polycarbonate resin having a structural unit of formula (1) and the structural unit of formula (2), with the relationship between the composition ratios being 0<k/(k+j)<1 when the composition ratio of the structural unit (1) is k and that of the structural unit (2) is j, or an aromatic polycarbonate resin having a repeat unit of formula (3). The formulas (1) to (3) are specified in the specification.
    Type: Application
    Filed: January 22, 2002
    Publication date: July 25, 2002
    Applicant: RICOH COMPANY, LTD.
    Inventors: Shinichi Kawamura, Masaomi Sasaki, Kazukiyo Nagai, Kohkoku Ri, Susumu Suzuka, Katsuhiro Morooka
  • Patent number: 6303736
    Abstract: An electrophotographic photoconductor has an electroconductive support, and a photoconductive layer which is formed thereon and contains an aromatic polycarbonate resin including at least a structural unit of formula (1): wherein a, b, c and d are each independently an integer of 0 to 4; n is an integer of 0 or 1; and R1, R2, R3 and R4 are each independently a halogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group, and R1, R2, R3 and R4 may each be the same or different when a, b, c and d are each an integer of 2, 3 or 4. Further, there are provided aromatic polycarbonate resins each including the structural unit of formula (1) and a structural unit with charge transporting properties.
    Type: Grant
    Filed: October 11, 2000
    Date of Patent: October 16, 2001
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichi Kawamura, Masaomi Sasaki, Kazukiyo Nagai, Chiaki Tanaka, Kohkoku Ri, Susumu Suzuka, Katsuhiro Morooka
  • Publication number: 20010012594
    Abstract: An image bearing material including a matrix resin and, within the matrix resin, a core/shell graft copolymer including a core including one or more polymers and a shell including a graft polymer which has a linear chain connected with the core and which is formed from one or more monomers. The image bearing material is preferably used for a surface layer of an electrophotographic photoreceptor, an intermediate transfer medium, and the like image bearing members to improve the abrasion resistance thereof.
    Type: Application
    Filed: December 22, 2000
    Publication date: August 9, 2001
    Applicant: Ricoh Company Limited
    Inventors: Kohkoku Ri, Masaomi Sasaki, Kazukiyo Nagai, Shinichi Kawamura
  • Patent number: 6210848
    Abstract: An electrophotographic photoconductor has an electroconductive support and a photoconductive layer formed thereon, a surface top portion of the photoconductor containing a high-molecular charge transport material including a polycarbonate copolymer synthesized from (a) a bisphenol monomer with an ionization potential of 6.0 eV or less, having a positive hole transporting function, and (b) a bisphenol monomer having a substituent at the o-position with respect to at least one hydroxyl group thereof, the substituent being bulkier than a fluorine atom. A process cartridge holds the above-mentioned photoconductor therein, and an electrophotographic image forming apparatus is provided with the above-mentioned photoconductor or process cartridge.
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: April 3, 2001
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazukiyo Nagai, Tetsuro Suzuki, Masaomi Sasaki, Kohkoku Ri, Shinichi Kawamura
  • Patent number: 6187492
    Abstract: A method of producing an aromatic polycarbonate resin includes the step of carrying out solution polymerization of a diphenol compound having a triarylamine structure with a diol compound of formula (I): wherein R1 and R2 are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a halogen atom; a and b are each independently an integer of 0 to 4; and Y is —COO— or in which Z is a substituted or unsubstituted bivalent aliphatic group or a substituted or unsubstituted arylene group.
    Type: Grant
    Filed: July 7, 1999
    Date of Patent: February 13, 2001
    Assignee: Ricoh Company, Ltd.
    Inventors: Kohkoku Ri, Masaomi Sasaki, Kazukiyo Nagai, Shinichi Kawamura, Susumu Suzuka, Katsuhiro Morooka
  • Patent number: 6187494
    Abstract: An electrophotographic photoconductor has an electroconductive support, and a photoconductive layer which is formed thereon and contains an aromatic polycarbonate resin including at least a structural unit of formula (1): wherein a, b, c and d are each independently an integer of 0 to 4; n is an integer of 0 or 1; and R1, R2, R3 and R4 are each independently a halogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group, and R1, R2, R3 and R4 may each be the same or different when a, b, c and d are each an integer of 2, 3 or 4. Further, there are provided aromatic polycarbonate resins each including the structural unit of formula (1) and a structural unit with charge transporting properties.
    Type: Grant
    Filed: July 23, 1999
    Date of Patent: February 13, 2001
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichi Kawamura, Masaomi Sasaki, Kazukiyo Nagai, Chiaki Tanaka, Kohkoku Ri, Susumu Suzuka, Katsuhiro Morooka