Patents by Inventor Masaomi Sasaki

Masaomi Sasaki 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: 4251614
    Abstract: The present invention provides disazo compounds expressed by the general formula: ##STR1## [wherein A represents a member selected from the group consisting of ##STR2## (wherein X represents a member selected from the group consisting of aromatic rings such as benzene ring, naphthalene ring, etc., hetero rings such as indole ring, carbazole ring, benzofuran ring, etc. and their substituents, Ar.sub.1 represents a member selected from the group consisting of aromatic rings such as benzene ring, naphthalene ring, etc., hetero rings such as dibenzofuran ring, etc. and their substituents, Ar.sub.2 and Ar.sub.3 represent a member selected from the group consisting of aromatic rings such as benzene ring, naphthalene ring, etc. and their substituents, R.sub.1 and R.sub.3 represent a member selected from the group consisting of hydrogen, lower alkyl radical or phenyl radical and their substituents and R.sub.
    Type: Grant
    Filed: June 30, 1978
    Date of Patent: February 17, 1981
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaomi Sasaki, Kiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Kyoji Tsutsui
  • Patent number: 4251613
    Abstract: The present invention provides disazo compounds expressed by the general formula I ##STR1## a process for the preparation of said compounds; and electrophotographic sensitive material having a high sensitivity as well as a high flexibility which comprise a conductive support and a photosensitive layer formed thereon, said photosensitive layer containing a disazo compound, as an effective ingredient, which is expressed by the general formula II A'--N.dbd.N--Z--N.dbd.N--A'.
    Type: Grant
    Filed: May 22, 1978
    Date of Patent: February 17, 1981
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaomi Sasaki, Kiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Kyoji Tsutsui
  • Patent number: 4247614
    Abstract: The present invention provides an electrophotographic element which comprises some disazo pigment expressed by the general formula ##STR1## [wherein R.sub.1 represents a member selected from the group consisting of hydrogen atom, methyl radical, ethyl radical, methoxy radical, ethoxy radical, chlorine atom, bromine atom, nitro radical, dimethylamino radical, diethylamino radical and phenyl radical; A represents ##STR2## (wherein R.sub.2 represents hydrogen atom or chlorine atom) or ##STR3## and n is an interger of 1 or 2.] as effective component contained in the photosensitive layer thereof.
    Type: Grant
    Filed: November 16, 1979
    Date of Patent: January 27, 1981
    Assignee: Ricoh Co., Ltd.
    Inventors: Masafumi Ohta, Kiyoshi Sakai, Mitsuru Hashimoto, Masaomi Sasaki, Tomiko Kawakami
  • Patent number: 4245021
    Abstract: An electrophotographic element according to the present invention exhibits an exceedingly high sensitivity and it comprises (1) an electroconductive support, a charge producing layer consisting essentially of a charge producing substance and a charge transport layer consisting essentially of a charge transport substance having the following general formula and a binder, the last-mentioned two layers being superposed in that order or vice versa on said support, or (2) an electroconductive support and a photosensitive layer, superposed thereon, and consisting essentially of a charge producing substance, a charge transport substance having said general formula and a binder: ##STR1## (wherein n is an integer of 1 or 2, R.sub.1 stands for hydrogen atom or an alkyl, nitro, dialkylamino, alkoxy, nitrile or carboxylic ester group, and R.sub.2 and R.sub.3 stand for hydrogen or halogen atom or nitro or dialkylamino group respectively).
    Type: Grant
    Filed: February 12, 1979
    Date of Patent: January 13, 1981
    Assignee: Ricoh Co., Ltd.
    Inventors: Takeo Kazami, Kiyoshi Sakai, Mitsuru Hashimoto, Masaomi Sasaki, Kyoji Tsutsui, Masafumi Ohta
  • Patent number: 4242260
    Abstract: The present invention provides disazo compounds expressed by the general formula I ##STR1## wherein A represents ##STR2## in which R represents alkyl radical, alkoxy radical, nitro radical, dialkylamino radical or halogen, n is 0 or an integer of 1, 2 or 3, and R may be either identical or different when n is an integer of 2 or 3. The disazo compounds are useful as photoconductive substances or charge-carrier generating substances in various kinds of electrophotographic elements.
    Type: Grant
    Filed: November 20, 1978
    Date of Patent: December 30, 1980
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaomi Sasaki, Kiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Akio Kozima
  • Patent number: 4192677
    Abstract: 1,3,4-oxadiazole derivative expressed by the general formula ##STR1## wherein R represents alkyl having 1-4 carbon atoms, dialkylamino having 1-4 carbon atoms, diarylamino, phenyl, styryl, halogenophenyl, nitrophenyl, alkylphenyl having 1-4 carbon atoms, alkoxyphenyl having 1-4 carbon atoms, cyanophenyl, carboxylic ester substituted phenyl, dialkylaminophenyl having 1-4 carbon atoms, naphthyl, anthryl, or heterocyclic radical, is a photoconductive substance with high sensitivity and is a compound useful as a constituent of electrophotographic plate.
    Type: Grant
    Filed: November 6, 1978
    Date of Patent: March 11, 1980
    Assignee: Ricoh Co., Ltd.
    Inventors: Mitsuo Okazaki, Akihiro Yamaguchi, Masaomi Sasaki
  • Patent number: 4157913
    Abstract: 1,3,4-OXADIAZOLE DERIVATIVES EXPRESSED BY THE GENERAL FORMULA ##STR1## , wherein R represents cyanophenyl, nitrophenyl, dialkylaminophenyl (wherein alkyl has 1-4 carbon atoms), julolidyl, N-alkylcarbazolyl (wherein alkyl has 1-4 carbon atoms) or ferrocenyl radical, are photoconductive substances possessing high sensitivity and are compounds useful as a constituent of electrophotographic plates.
    Type: Grant
    Filed: December 22, 1977
    Date of Patent: June 12, 1979
    Assignee: Ricoh Co., Ltd.
    Inventors: Mitsuo Okazaki, Akihiro Yamaguchi, Masaomi Sasaki
  • Patent number: 4157914
    Abstract: 1,3,4-OXADIAZOLE DERIVATIVES EXPRESSED BY THE GENERAL FORMULA ##STR1## wherein R represents cyanophenyl, nitrophenyl, dialkylaminophenyl (wherein alkyl has 1-4 carbon atoms), julolidyl, N-alkylcarbazolyl (wherein alkyl has 1-4 carbon atoms) or ferrocenyl radical are photoconductive substances possessing high sensitivity and are compounds useful as a constituent of electrophotographic plates.
    Type: Grant
    Filed: December 22, 1977
    Date of Patent: June 12, 1979
    Assignee: Ricoh Co., Ltd.
    Inventors: Mitsuo Okazaki, Akihiro Yamaguchi, Masaomi Sasaki
  • Patent number: 4141729
    Abstract: 1,3,4-OXADIAZOLE DERIVATIVE EXPRESSED BY THE GENERAL FORMULA ##STR1## wherein R represents alkyl having 1-4 carbon atoms, dialkylamino having 1-4 carbon atoms, diarylamino, phenyl, styryl, halogenophenyl, nitrophenyl, alkylphenyl having 1-4 carbon atoms, alkoxyphenyl having 1-4 carbon atoms, cyanophenyl, carboxylic ester substituted phenyl, dialkylaminophenyl having 1-4 carbon atoms, naphthyl, anthryl, or heterocyclic radical, is a photoconductive substance with high sensitivity and is a compound useful as a constituent of electrophotographic plate.
    Type: Grant
    Filed: May 12, 1977
    Date of Patent: February 27, 1979
    Assignee: Ricoh Company, Ltd.
    Inventors: Mitsuo Okazaki, Akihiro Yamaguchi, Masaomi Sasaki
  • Patent number: 4134761
    Abstract: 3-(-FLUORENYLIDENE)CARBAZOLE DERIVATIVES, PROCESS FOR PREPARING SAME AND ELECTROPHOTOGRAPHIC LIGHT-SENSITIVE MATERIAL CONTAINING 3-(9-FLUORENYLIDENE)CARBAZOLE DERIVATIVES.
    Type: Grant
    Filed: April 7, 1977
    Date of Patent: January 16, 1979
    Assignee: Ricoh Co., Ltd.
    Inventors: Mitsuo Okazaki, Akihiro Yamaguchi, Akio Kozima, Masaomi Sasaki
  • Patent number: 4099970
    Abstract: 1,3,4-Oxadiazle derivatives expressed by the general formula ##STR1## wherein R represents cyanophenyl, nitrophenyl, dialkylaminophenyl (wherein alkyl has 1 - 4 carbon atoms), julolidyl, N-alkylcarbazoyl (wherein alkyl has 1 - 4 carbon atoms) or ferrocenyl radical are photoconductive substances possessing high sensitivity and are compounds useful as a constituent of electrophotographic plates.
    Type: Grant
    Filed: December 22, 1977
    Date of Patent: July 11, 1978
    Assignee: Ricoh Co., Ltd.
    Inventors: Mitsuo Okazaki, Akihiro Yamaguchi, Masaomi Sasaki
  • Patent number: 4091208
    Abstract: .alpha.-(9-Anthryl)-.beta.-(3-carbazolyl)ethylene derivatives, process for preparing same and electrophotographic light-sensitive materials containing .alpha.-(9-anthryl)-.beta.-(3-carbazolyl)ethylene derivative.
    Type: Grant
    Filed: April 7, 1977
    Date of Patent: May 23, 1978
    Assignee: Ricoh Co., Ltd.
    Inventors: Mitsuo Okazaki, Akihiro Yamaguchi, Masaomi Sasaki
  • Patent number: 4088484
    Abstract: 1,3,4-OXADIAZOLE DERIVATIVES EXPRESSED BY THE GENERAL FORMULA ##STR1## wherein R represents cyanophenyl, nitrophenyl, dialkylaminophenyl (wherein alkyl has 1-4 carbon atoms), julolidyl, N-alkylcarbazolyl (wherein alkyl has 1-4 carbon atoms) or ferrocenyl radical, are photoconductive substances possessing high sensitivity and are compounds useful as a constituent of electrophotographic plates.
    Type: Grant
    Filed: April 4, 1977
    Date of Patent: May 9, 1978
    Assignee: Ricoh Co., Ltd.
    Inventors: Mitsuo Okazaki, Akihiro Yamaguchi, Masaomi Sasaki