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: 4500355
    Abstract: An aqueous ink composition for general use and for ink-jet printing which comprises, as its main components at least one dye selected from the group consisting of a cyan azo dye, a megenta azo dye and a yellow azo dye and a humectant.
    Type: Grant
    Filed: September 28, 1983
    Date of Patent: February 19, 1985
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaru Shimada, Masaomi Sasaki
  • Patent number: 4486519
    Abstract: A novel bisazo compound of the formula ##STR1## where n=2 or 3, and A is ##STR2## when n=2, and when n=3, A is the above (a), (b) or (c), and an electrophotographic photoconductor comprising, on an electroconductive support material, a photoconductive layer containing the above bisazo compound, which electrophotographic photoconductor exhibits relatively high photo-sensitivity and usefulness for electrophotographic copying.
    Type: Grant
    Filed: June 1, 1983
    Date of Patent: December 4, 1984
    Assignee: Ricoh Company, Ltd.
    Inventor: Masaomi Sasaki
  • Patent number: 4454212
    Abstract: An electrophotographic photoconductor is prepared by forming a photoconductive layer containing a hydrazone compound therein on an electroconductive support member. The hydrazone compounds represented by the following general formula, are useful as photoconductive materials and as charge transport materials for use in electrophotography: ##STR1## wherein R.sub.1 represents a methyl group, an ethyl group, a 2-hydroxyethyl group, or a 2-chloroethyl group, and R.sub.2 represents a methyl group, an ethyl group, a benzyl group or a phenyl group.
    Type: Grant
    Filed: September 15, 1982
    Date of Patent: June 12, 1984
    Assignee: Ricoh Company Limited
    Inventors: Kiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Masaomi Sasaki
  • Patent number: 4439506
    Abstract: An electrophotographic element comprising an electrically conductive substrate, a charge carrier generating layer and a charge transfer layer superimposed on said substrate, wherein said charge carrier generating layer contains a trisazo compound having the general formula (I): ##STR1## (wherein, Ar represents ##STR2## and said charge transfer layer contains a charge transfer substance having the general formula (II) or (III): ##STR3## (wherein, R.sup.1 represents a hydrogen or halogen atom, R.sup.2 represents hydrogen, an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, a dialkylamino group, or a substituted or non-substituted diaralkylamino group, and R.sup.3 represents hydrogen, an alkyl group or a halogen atom.) ##STR4## (wherein, R.sup.
    Type: Grant
    Filed: May 21, 1982
    Date of Patent: March 27, 1984
    Assignee: Ricoh Co., Ltd.
    Inventors: Masafumi Ohta, Masaomi Sasaki
  • Patent number: 4426327
    Abstract: The present invention provides disazo compounds expressed by the general formula ##STR1## [wherein A represents ##STR2## (wherein R represents alkyl radical, alkoxy radical, nitro radical, dialkylamino radical or halogen, n is 0 or an integer ranging from 1 to 3, and R may be identical or different when n is an integer of 2 or 3)]; a process for the preparation of said compounds; and photosensitive materials having a high sensitivity as well as a high flexibility which comprises a conductive support and a photosensitive layer formed thereon, said photosensitive layer containing a disazo pigment, as an effective ingredient, which is expressed by the general formula ##STR3## [wherein R' represents a member selected from the group consisting of hydrogen, ethyl radical, chloroethyl radical and hydroxyethyl radical, A' represents a member selected from the group consisting of ##STR4## (wherein X represents a member selected from the group consisting of aromatic rings such as benzene ring, naphthalene ring, etc.
    Type: Grant
    Filed: November 5, 1980
    Date of Patent: January 17, 1984
    Assignee: Ricoh Co., Ltd.
    Inventors: Mitsuru Hashimoto, Masafumi Ohta, Akio Kozima, Kiyoshi Sakai, Masaomi Sasaki
  • Patent number: 4390608
    Abstract: A layered electrophotographic photoconductor whose charge generation layer comprises a bisazo pigment selected from the group consisting of the bisazo pigments represented by formula (1) and whose charge transport layer contains a charge transport material selected from the group consisting of anthrancene compounds represented by formula (2) or from the group consisting of distyrylbenzene compounds represented by formula (3) ##STR1##
    Type: Grant
    Filed: December 9, 1981
    Date of Patent: June 28, 1983
    Assignee: Ricoh Company, Ltd.
    Inventors: Mitsuru Hashimoto, Masaomi Sasaki, Toshio Fukagai, Tatsuya Katoh, deceased, by Mankichi Katoh, heir
  • Patent number: 4365014
    Abstract: An electrophotographic photoconductor is prepared by forming a photoconductive layer containing a hydrazone compound therein on an electroconductive support member. The hydrazone compounds represented by the following general formula, are useful as photoconductive materials and as charge transport materials for use in electrophotography: ##STR1## wherein R.sub.1 represents a methyl group, an ethyl group, a 2-hydroxyethyl group, or a 2-chloroethyl group, and R.sub.2 represents a methyl group, an ethyl group, a benzyl group or a phenyl group.
    Type: Grant
    Filed: September 27, 1979
    Date of Patent: December 21, 1982
    Assignee: Ricoh Company, Limited
    Inventors: Kiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Masaomi Sasaki
  • Patent number: 4363859
    Abstract: An electrophotographic photoconductor comprises an electroconductive supporting material and a photoconductive layer containing a charge carrier producing pigment and a charge transporting material therein, which is formed on the electroconductive supporting material. As the charge carrier producing pigment, azo pigments and other materials which are known as the charge carrier producing pigments are employed. As the charge transporting material, anthracene compounds which are represented by the general formula ##STR1## are employed, wherein X represents H (hydrogen) or a halogen atom and R represents an unsubstituted phenyl radical, a substituted phenyl radial having a halogen substituent, a cyano substituent, a lower dialkyl amino substituent with one to four carbon atoms, a lower alkoxyl substituent with one to five carbon atoms, and nitro substituent, a napthyl radical, an anthryl radical, and a carbazoyl radical.
    Type: Grant
    Filed: October 13, 1978
    Date of Patent: December 14, 1982
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaomi Sasaki, Kyoji Tsutsui
  • Patent number: 4349616
    Abstract: An electrophotographic element comprising an electrically conductive substrate and a monolayer or multilayer type photo-sensitive layer, superposed thereon, containing as an effective ingredient a disazo pigment having the general formula (I): ##STR1## wherein Ar.sup.1 and Ar.sup.2 each represent a phenylene group. However, when Ar.sup.1 is 1,4-phenylene group Ar.sup.2 is 1,2- or 1,3-phenylene group; when Ar.sup.1 is 1,3-phenylene group Ar.sup.2 may be any one of 1,2-, 1,3- and 1,4-phenylene groups; and when Ar.sup.1 is 1,2-phenylene group Ar.sup.2 is 1,3-phenylene group. X represents aromatic rings such as benzene ring, naphthalene ring and the like, hetero rings such as indole ring, carbazole ring, benzofuran ring and the like or their substitution products; Ar.sup.
    Type: Grant
    Filed: December 19, 1980
    Date of Patent: September 14, 1982
    Assignee: Ricoh Co., Ltd.
    Inventor: Masaomi Sasaki
  • Patent number: 4327020
    Abstract: Bis-azo compounds represented by the general formula ##STR1## where A represents ##STR2## wherein R represents alkyl, alkoxy, nitro, dialkylamino or halogen, and n represents an integer 0, 1, 2 or 3 and when n is 2 or 3, R represents identical or different substituents selected from the group of alkyl, alkoxy, nitro, dialkylamino and halogen.
    Type: Grant
    Filed: June 11, 1980
    Date of Patent: April 27, 1982
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaomi Sasaki, Masafumi Ohta, Kyoji Tsutsui
  • Patent number: 4325871
    Abstract: A bis-azo compound of the formula ##STR1## wherein A represents ##STR2## wherein R represents alkyl, alkoxy, nitro, dialkylamino or halogen, and n represents an integer 0, 1, 2 or 3 and when n is 2 or 3, R represents identical or different substituents selected from the group of alkyl, alkoxy, nitro, dialkylamino and halogen. The bis-azo compound is useful as a photoconductive material for the preparation of electrophotographic photoconductors.
    Type: Grant
    Filed: June 11, 1980
    Date of Patent: April 20, 1982
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaomi Sasaki, Mitsuru Hashimoto, Tomiko Kawakami
  • Patent number: 4314015
    Abstract: The present invention provides electrophotographic sensitive materials 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 one disazo pigment, as an effective ingredient, which is selected from the group consisting of disazo pigments expressed by the following general formulas I, II, III, and IV, ##STR1## [(wherein A is selected from the group consisting of ##STR2## is 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 is selected from the group consisting of aromatic rings such as benzene ring, naphthalene ring, etc., hetero rings such as dibenzofuran, etc. and their substituents, Ar.sub.2 and Ar.sub.3 are selected from the group consisting of aromatic rings such as benzene ring, naphthalene ring, etc. and their substituents, R.sub.1 and R.
    Type: Grant
    Filed: December 19, 1980
    Date of Patent: February 2, 1982
    Assignee: Ricoh Co., Ltd.
    Inventors: Mitsuru Hashimoto, Kiyoshi Sakai, Masafumi Ohta, Akio Kozima, Masaomi Sasaki, Kyoji Tsutsui
  • Patent number: 4299896
    Abstract: The present invention provides electrophotographic sensitive materials 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 one disazo pigment, as an effective ingredient, which is selected from the group consisting of disazo pigments expressed by the following general formulas I, II, III, and IV, ##STR1##
    Type: Grant
    Filed: July 17, 1978
    Date of Patent: November 10, 1981
    Assignee: Ricoh Co., Ltd.
    Inventors: Mitsuru Hashimoto, Kiyoshi Sakai, Masafumi Ohta, Akio Kozima, Masaomi Sasaki, Kyoji Tsutsui
  • Patent number: 4293628
    Abstract: The present invention provides disazo compounds expressed by the general formula ##STR1## [wherein A represents ##STR2## (wherein R represents alkyl radical, alkoxy radical, nitro radical, dialkylamino radical or halogen, n is 0 or an integer ranging from 1 to 3, and R may be identical or different when n is an integer of 2 or 3)]; a process for the preparation of said compounds; and photosensitive materials having a high sensitivity as well as a high flexibility which comprises a conductive support and a photosensitive layer formed thereon, said photosensitive layer containing a disazo pigment, as an effective ingredient, which is expressed by the general formula ##STR3## [wherein R' represents a member selected from the group consisting of hydrogen, ethyl radical, chloroethyl radical and hydroxyethyl radical, A' represents a member selected from the group consisting of ##STR4## (wherein X represents a member selected from the group consisting of aromatic rings such as benzene ring, naphthalene ring, etc.
    Type: Grant
    Filed: January 26, 1978
    Date of Patent: October 6, 1981
    Assignee: Ricoh Co., Ltd.
    Inventors: Mitsuru Hashimoto, Masafumi Ohta, Akio Kozima, Kiyoshi Sakai, Masaomi Sasaki
  • Patent number: 4293492
    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: May 20, 1980
    Date of Patent: October 6, 1981
    Assignee: Ricoh Co., Ltd.
    Inventors: Masaomi Sasaki, Kiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Kyoji Tsutsui
  • Patent number: 4279981
    Abstract: The present invention provides trisazo compounds expressed by the general formula I ##STR1## [wherein A represents ##STR2## (wherein R represents hydrogen, alkyl radical, alkoxy radical, nitro radical, dialkylamino radical or halogen, and n is an integer of 1, 2 or 3, R may be either identical or different when n is an integer of 2 or 3)]; a process for the preparation of said trisazo compounds; and electrophotographic sensitive materials having a high sensitivity as well as a high flexibility which comprise a conductive support and a photosensitive layer containing a trisazo compound, as an effective ingredient thereof, which is expressed by the general formula II ##STR3## [wherein A' represents ##STR4## (wherein Z represents aromatic rings such as benzene ring, naphthalene ring, etc., hetero rings such as indole ring, carbazole ring, benzofuran ring, etc. or their substituents, Ar.sub.1 represents aromatic rings such as benzene ring, naphthalene ring, etc., hetero rings such as dibenzofuran ring, etc.
    Type: Grant
    Filed: April 18, 1978
    Date of Patent: July 21, 1981
    Assignee: Ricoh Company, Ltd.
    Inventors: Masafumi Ohta, Kiyoshi Sakai, Mitsuru Hashimoto, Akio Kozima, Masaomi Sasaki
  • Patent number: 4272598
    Abstract: The present invention provides disazo compounds expressed by the general formula I ##STR1## [wherein A represents ##STR2## (wherein 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)]; a process for the preparation of said compounds; and electrophotographic sensitive materials 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 ##STR3## [wherein A' represents ##STR4## (wherein X represents aromatic rings such as benzene ring, naphthalene ring, etc., hetero rings such as indole ring, carbazole ring, benzofuran ring, etc. or their substituents, Ar.sub.1 represents aromatic rings such as benzene ring, naphthalene ring, etc.
    Type: Grant
    Filed: April 20, 1978
    Date of Patent: June 9, 1981
    Assignee: Ricoh Co., Ltd.
    Inventors: Masaomi Sasaki, Kiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Akio Kozima
  • Patent number: 4268596
    Abstract: The present invention provides an electrophotographic element which comprises an electroconductive support and a photosensitive layer, formed thereon, which contains some disazo pigment expressed by the general formula ##STR1## [wherein A represents ##STR2## (wherein X represents aromatic ring, hetero ring or substitutes thereof, R.sub.1 represents aromatic ring, hetero ring or substitutes thereof, Ar.sub.2 and Ar.sub.3 represents aromatic ring or substitutes thereof, R.sub.1 and R.sub.3 represents hydrogen, lower alkyl group, phenyl group or substitutes thereof, and R.sub.2 represents lower alkyl group, carboxyl group or esters thereof)].
    Type: Grant
    Filed: November 21, 1979
    Date of Patent: May 19, 1981
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaomi Sasaki, Mitsuru Hashimoto, Tomiko Kawakami
  • Patent number: 4264695
    Abstract: A photosensitive material for use in electrophotography which comprises a conductive support, a first layer consisting essentially of a substance capable of generating a conductive carrier through light absorption and an electron donor or an electron acceptor, and a second layer consisting essentially of an electron acceptor or an electron donor, to wit, a substance constituting the opposite party of the electron donor or the electron acceptor contained in the first layer, said first and second layers being formed in that order on said conductive support.
    Type: Grant
    Filed: January 28, 1980
    Date of Patent: April 28, 1981
    Assignee: Ricoh Co., Ltd.
    Inventors: Akio Kozima, Mitsuru Hashimoto, Masafumi Ohta, Masaomi Sasaki, Zenjiro Okuno
  • Patent number: 4260672
    Abstract: The present invention provides an electrophotographic element of a high sensitivity and a high flexibility comprising an electroconductive support and a photosensitive layer provided thereon and containing as an effective ingredient therein a disazo compound represented by the following general formula: ##STR1## wherein A is a radical selected from the group consisting of: ##STR2## in which X represents a ring selected from the group consisting of aromatic rings such as benzene ring and naphthalene ring, hetero rings such as indole ring, carbazole ring and benzofuran ring, and substituted derivatives thereof; Ar.sub.1 represents a radical selected from the group consisting of aromatic rings such as benzene ring and naphthalene ring, hetero rings such as dibenzofuran ring and substituted derivatives thereof; Ar.sub.2 and Ar.sub.3 represent radicals respectively selected from the group consisting of aromatic rings such as benzene ring and naphthalene ring, and substituted derivatives thereof; R.sub.1 and R.sub.
    Type: Grant
    Filed: July 7, 1978
    Date of Patent: April 7, 1981
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaomi Sasaki, Kiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Kyoji Tsutsui