Patents by Inventor Makoto Kitahara

Makoto Kitahara 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: 4487824
    Abstract: An electrophotographic photosensitive member comprises an electrically conductive substrate and a layer containing a hydrazone compound represented by the following formula (1) and a binder: ##STR1## wherein; R.sub.1 and R.sub.2 each represent alkyl, aralkyl, or aryl, substituted or unsubstituted, or R.sub.1 and R.sub.2 together with the nitrogen atom to which they are attached form a 5- or 6-membered ring; R.sub.3 represents halogen or fluoroalkyl; R.sub.4 and R.sub.6 each represent hydrogen or halogen; R.sub.5 represents hydrogen, alkyl, alkoxyl, or halogen; each of R.sub.7 and R.sub.8 represents alkyl, aralkyl, or aryl, substituted or unsubstituted; and n represents an integer of 0 or 1.
    Type: Grant
    Filed: May 9, 1983
    Date of Patent: December 11, 1984
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazuharu Katagiri, Katsunori Watanabe, Kiyoshi Sakai, Shozo Ishikawa, Makoto Kitahara
  • Patent number: 4485159
    Abstract: In an electrophotographic light-sensitive material comprising at least one electric charge generation layer comprising a charge generating substance and a binder resin therefor and at least one electric charge transport layer on an electrically conductive base, said electrophotographic light-sensitive material is a laminate type electrophotographic light-sensitive material wherein the binder resin for the electric charge generating substance contains at least one polyvinylpyridine resin.
    Type: Grant
    Filed: October 23, 1980
    Date of Patent: November 27, 1984
    Assignee: Copyer Co., Ltd., Canon Inc.
    Inventors: Katsunori Watanabe, Shigeto Ohta, Kiyoshi Sakai, Shozo Ishikawa, Makoto Kitahara
  • Patent number: 4471040
    Abstract: An electrophotographic photosensitive member have a photosensitive layer, said photosensitive layer comprising at least one dis-azo pigment of Formula (I) or Formula (II) shown below: ##STR1## wherein Z represents an oxygen atom, a sulfur atom or >N--A.sub.2, wherein A.sub.2 is a hydrogen atom or a lower alkyl, A.sub.1 a hydrogen atom, a lower alkyl or a halogen atom; Ph.sub.1 an unsubstituted or substituted phenylene group, n an integer of 0 or 1, and B.sub.1 a coupler residue; with proviso that when n is 0, Z is an oxygen atom and A.sub.1 is a hydrogen atom, the case where Ph.sub.1 represents substituted phenyl radicals except for unsubstituted or mono-substituted phenyl radicals with a halogen atom, a lower alkyl or an alkoxy group;and ##STR2## wherein Ph.sub.2 represents an unsubstituted or substituted phenylene group and B.sub.2 a coupler residue.
    Type: Grant
    Filed: September 9, 1981
    Date of Patent: September 11, 1984
    Assignees: Canon Kabushiki Kaisha, Copyer Kabushiki Kaisha
    Inventors: Kazuharu Katagiri, Katsunori Watanabe, Shozo Ishikawa, Makoto Kitahara
  • Patent number: 4419428
    Abstract: An electrophotographic light-sensitive medium is described comprising at least an electrically conductive layer, a charge generation layer and a charge transport layer, the charge generation layer containing a dis-azo compound represented by Formula (1) wherein A represents a single bond, ##STR1## B represents a coupler having aromatic properties; and R represents a group selected from hydrogen, a halogen and a lower alkyl having 1 to 4 carbon atoms.
    Type: Grant
    Filed: May 18, 1981
    Date of Patent: December 6, 1983
    Assignees: Copyer Co., Ltd., Canon Inc.
    Inventors: Kazuharu Katagiri, Shozo Ishikawa, Katsunori Watanabe, Shigeto Ohta, Makoto Kitahara
  • Patent number: 4413045
    Abstract: An electrophotographic photosensitive member is characterized by comprising a charge generation layer containing at least one disazo pigment represented by the following formula [I] and a charge transport layer containing at least one hydrazone compound represented by the following formula [II]: ##STR1## wherein A is a coupler residue, B represents hydrogen, halogen, alkyl, or alkoxy, and n is an integer of 1 to 4; ##STR2## wherein R.sub.1 represents N,N-dialkyl amino, or N,N-diarylamino, or N-alkyl-N-arylamino, or alkoxy or aryloxy, each being substituted or unsubstituted; R.sub.2 and R.sub.3 each represent alkyl, aralkyl, or aryl, each being substituted or unsubstituted, or R.sub.2 and R.sub.3, together with the nitrogen atom which links them, represent nitrogen-containing heterocyclic ring; R.sub.4 represents hydrogen, or alkyl, aralkyl, or aryl, each being substituted or unsubstituted; R.sub.5 represents hydrogen, alkyl, or alkoxy; and l is 0 or 1.
    Type: Grant
    Filed: May 24, 1982
    Date of Patent: November 1, 1983
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shozo Ishikawa, Kazuharu Katagiri, Katsunori Watanabe, Kiyoshi Sakai, Makoto Kitahara
  • Patent number: 4399206
    Abstract: An electrophotographic photosensitive member is characterized by having a photosensitive layer containing at least one disazo pigment represented by the formula ##STR1## wherein Cp represents a coupler residue; B.sub.1, B.sub.2, B.sub.1 ', and B.sub.2 ' independently of one another represent atoms or groups selected from the group consisting of hydrogen, halogen, lower alkyl, lower alkoxy, acylamino, and hydroxyl; and A represents ##STR2## (D.sub.1 and D.sub.
    Type: Grant
    Filed: September 30, 1981
    Date of Patent: August 16, 1983
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazuharu Katagiri, Katsunori Watanabe, Shozo Ishikawa, Makoto Kitahara
  • Patent number: 4399207
    Abstract: An electrophotographic photosensitive member having a layer containing at least one compound represented by the formula ##STR1## wherein X.sub.1 represents a residue necessary for completing a substituted or unsubstituted aromatic hydrocarbon ring; X.sub.2 represents a residue necessary for completing a substituted or unsubstituted heterocyclic ring; R.sub.1, R.sub.2, R.sub.3, and A each represent hydrogen, alkyl, aralkyl, or aryl, substituted or unsubstituted; and m is 0 or 1.
    Type: Grant
    Filed: July 22, 1982
    Date of Patent: August 16, 1983
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kiyoshi Sakai, Minoru Mabuchi, Shozo Ishikawa, Makoto Kitahara
  • Patent number: 4391889
    Abstract: An electrophotographic photosensitive member comprises a layer containing at least one member of the hydrazone compounds of the formula: ##STR1## where R.sub.1, R.sub.2 and R.sub.3 are selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted aralkyl, and substituted or unsubstituted aryl, and R.sub.1 and R.sub.2 can not be simultaneously alkyl; and R.sub.4 is substituted or unsubstituted aryl.
    Type: Grant
    Filed: November 23, 1981
    Date of Patent: July 5, 1983
    Assignee: Canon Kabushiki Kaisha
    Inventors: Minoru Mabuchi, Kiyoshi Sakai, Shozo Ishikawa, Yuji Egashira, Makoto Kitahara
  • Patent number: 4390611
    Abstract: An electrophotographic photosensitive member having a photosensitive layer is characterized in that said photosensitive layer contains azo pigments having at least one of azo groups linked to a coupler residue represented by the following formula [1] or [2]: ##STR1## wherein R.sub.1 and R.sub.3 independently represent hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aralkyl, or substituted or unsubstituted aryl, and R.sub.2 and R.sub.4 independently represent substituted or unsubstituted aryl.
    Type: Grant
    Filed: September 22, 1981
    Date of Patent: June 28, 1983
    Inventors: Shozo Ishikawa, Kazuharu Katagiri, Katsunori Watanabe, Makoto Kitahara
  • Patent number: 4359513
    Abstract: An electrophotographic light-sensitive medium is described comprising a light-sensitive layer containing a dis-azo compound represented by Formula (1) ##STR1## wherein A represents a coupler having aromatic properties.
    Type: Grant
    Filed: February 19, 1981
    Date of Patent: November 16, 1982
    Assignees: Copyer Co., Ltd., Canon Inc.
    Inventors: Kazuharu Katagiri, Katsunori Watanabe, Shigeto Ohta, Shozo Ishikawa, Makoto Kitahara
  • Patent number: 4359515
    Abstract: An electrophotographic light-sensitive medium comprising a light-sensitive layer containing a dis-azo compound represented by Formula (1) ##STR1## wherein A represents a single chemical bond, a divalent hydrocarbon group containing a conjugated double bond, a divalent hydrocarbon group containing a nitrogen atom in a conjugated double bond, or a divalent heterocyclic group which may be condensed with a benzene ring or substituted and forms a conjugated double bond system in combination with the adjacent azomethine groups, and B and B', which may be the same or different, each represents a coupler having aromatic properties.
    Type: Grant
    Filed: February 25, 1981
    Date of Patent: November 16, 1982
    Assignees: Copyer Co., Ltd., Canon Inc.
    Inventors: Kazuharu Katagiri, Katsunori Watanabe, Shigeto Ohta, Shozo Ishikawa, Makoto Kitahara
  • Patent number: 4356243
    Abstract: An electrophotographic light-sensitive medium is described comprising at least an electrically conductive layer, a charge generation layer and a charge transport layer, the charge generation layer containing a dis-azo compound represented by Formula (1) ##STR1## wherein A is a coupler having aromatic properties, and B is a group selected from hydrogen, halogen, lower alkyl having 1 to 4 carbon atoms and lower alkoxy having 1 to 4 carbon atoms.
    Type: Grant
    Filed: February 19, 1981
    Date of Patent: October 26, 1982
    Assignee: Copyer Co., Ltd.
    Inventors: Shozo Ishikawa, Kazuharu Katagiri, Katsunori Watanabe, Shigeto Ohta, Makoto Kitahara
  • Patent number: 4268595
    Abstract: An electrostatic recording material comprising a support having formed thereon a dielectric layer composed of a terpolymer consisting of (a) methacrylic acid, (b) a monomer selected from the group consisting of (1) acrylic acid esters containing at least 4 carbon atoms and (2) methacrylic acid esters containing at least 5 carbon atoms, and (c) a monomer selected from the group consisting of (1) acrylic acid esters containing at least 4 carbon atoms and (2) methacrylic acid esters containing at least 5 carbon atoms, wherein monomer (b) and monomer (c) are different and at least one of the monomers (b) and (c) is an acrylic acid ester containing at least 11 carbon atoms or a methacrylic acid ester containing at least 8 carbon atoms, and a method for producing an electrostatic recording material, which comprises converting such a terpolymer to a water-soluble or water-emulsifiable salt of the terpolymer in which about 20 to 100 mol% of the carboxyl groups present form a salt with ammonia and/or a volatile amine,
    Type: Grant
    Filed: November 5, 1979
    Date of Patent: May 19, 1981
    Assignee: Copyer Co., Ltd.
    Inventors: Kazuharu Katagiri, Shozo Ishikawa, Shigeto Ohta, Makoto Kitahara
  • Patent number: 4097646
    Abstract: An electrostatic recording material, such as a dielectric coated paper and a paper for transfer of an electrostatic image, having a dielectric layer comprising a copolymer which comprises about 15 to 70 mol% of methacrylic acid and about 85 to 30 mol% of a methacrylate or acrylate and which contains free carboxylic acid groups, and a process for producing the electrostatic recording material comprising coating a water-soluble or -emulsifiable ammonium or amine salt of the copolymer on a support and drying the coated support.
    Type: Grant
    Filed: August 18, 1975
    Date of Patent: June 27, 1978
    Assignee: Copyer Co., Ltd.
    Inventors: Makoto Kitahara, Shozo Ishikawa, Kazuharu Katagiri, Tetsuo Arita, Shoji Masubuchi