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).
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Patent number: 4500355Abstract: 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: GrantFiled: September 28, 1983Date of Patent: February 19, 1985Assignee: Ricoh Company, Ltd.Inventors: Masaru Shimada, Masaomi Sasaki
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Patent number: 4486519Abstract: 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: GrantFiled: June 1, 1983Date of Patent: December 4, 1984Assignee: Ricoh Company, Ltd.Inventor: Masaomi Sasaki
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Patent number: 4454212Abstract: 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: GrantFiled: September 15, 1982Date of Patent: June 12, 1984Assignee: Ricoh Company LimitedInventors: Kiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Masaomi Sasaki
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Patent number: 4439506Abstract: 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: GrantFiled: May 21, 1982Date of Patent: March 27, 1984Assignee: Ricoh Co., Ltd.Inventors: Masafumi Ohta, Masaomi Sasaki
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Patent number: 4426327Abstract: 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: GrantFiled: November 5, 1980Date of Patent: January 17, 1984Assignee: Ricoh Co., Ltd.Inventors: Mitsuru Hashimoto, Masafumi Ohta, Akio Kozima, Kiyoshi Sakai, Masaomi Sasaki
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Patent number: 4390608Abstract: 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: GrantFiled: December 9, 1981Date of Patent: June 28, 1983Assignee: Ricoh Company, Ltd.Inventors: Mitsuru Hashimoto, Masaomi Sasaki, Toshio Fukagai, Tatsuya Katoh, deceased, by Mankichi Katoh, heir
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Patent number: 4365014Abstract: 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: GrantFiled: September 27, 1979Date of Patent: December 21, 1982Assignee: Ricoh Company, LimitedInventors: Kiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Masaomi Sasaki
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Patent number: 4363859Abstract: 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: GrantFiled: October 13, 1978Date of Patent: December 14, 1982Assignee: Ricoh Company, Ltd.Inventors: Masaomi Sasaki, Kyoji Tsutsui
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Patent number: 4349616Abstract: 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: GrantFiled: December 19, 1980Date of Patent: September 14, 1982Assignee: Ricoh Co., Ltd.Inventor: Masaomi Sasaki
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Patent number: 4327020Abstract: 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: GrantFiled: June 11, 1980Date of Patent: April 27, 1982Assignee: Ricoh Company, Ltd.Inventors: Masaomi Sasaki, Masafumi Ohta, Kyoji Tsutsui
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Patent number: 4325871Abstract: 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: GrantFiled: June 11, 1980Date of Patent: April 20, 1982Assignee: Ricoh Company, Ltd.Inventors: Masaomi Sasaki, Mitsuru Hashimoto, Tomiko Kawakami
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Patent number: 4314015Abstract: 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: GrantFiled: December 19, 1980Date of Patent: February 2, 1982Assignee: Ricoh Co., Ltd.Inventors: Mitsuru Hashimoto, Kiyoshi Sakai, Masafumi Ohta, Akio Kozima, Masaomi Sasaki, Kyoji Tsutsui
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Patent number: 4299896Abstract: 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: GrantFiled: July 17, 1978Date of Patent: November 10, 1981Assignee: Ricoh Co., Ltd.Inventors: Mitsuru Hashimoto, Kiyoshi Sakai, Masafumi Ohta, Akio Kozima, Masaomi Sasaki, Kyoji Tsutsui
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Patent number: 4293628Abstract: 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: GrantFiled: January 26, 1978Date of Patent: October 6, 1981Assignee: Ricoh Co., Ltd.Inventors: Mitsuru Hashimoto, Masafumi Ohta, Akio Kozima, Kiyoshi Sakai, Masaomi Sasaki
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Patent number: 4293492Abstract: 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: GrantFiled: May 20, 1980Date of Patent: October 6, 1981Assignee: Ricoh Co., Ltd.Inventors: Masaomi Sasaki, Kiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Kyoji Tsutsui
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Patent number: 4279981Abstract: 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: GrantFiled: April 18, 1978Date of Patent: July 21, 1981Assignee: Ricoh Company, Ltd.Inventors: Masafumi Ohta, Kiyoshi Sakai, Mitsuru Hashimoto, Akio Kozima, Masaomi Sasaki
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Patent number: 4272598Abstract: 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: GrantFiled: April 20, 1978Date of Patent: June 9, 1981Assignee: Ricoh Co., Ltd.Inventors: Masaomi Sasaki, Kiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Akio Kozima
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Patent number: 4268596Abstract: 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: GrantFiled: November 21, 1979Date of Patent: May 19, 1981Assignee: Ricoh Company, Ltd.Inventors: Masaomi Sasaki, Mitsuru Hashimoto, Tomiko Kawakami
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Patent number: 4264695Abstract: 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: GrantFiled: January 28, 1980Date of Patent: April 28, 1981Assignee: Ricoh Co., Ltd.Inventors: Akio Kozima, Mitsuru Hashimoto, Masafumi Ohta, Masaomi Sasaki, Zenjiro Okuno
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Patent number: 4260672Abstract: 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: GrantFiled: July 7, 1978Date of Patent: April 7, 1981Assignee: Ricoh Company, Ltd.Inventors: Masaomi Sasaki, Kiyoshi Sakai, Mitsuru Hashimoto, Masafumi Ohta, Kyoji Tsutsui