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: 5641598
    Abstract: A stilbene compound is disclosed which has the following general formula (I): ##STR1## wherein R.sup.1 and R.sup.2 each stand for hydrogen, an alkyl group or an acyl group and Ar.sup.1 and Ar.sup.2 each stand for a monovalent homocyclic aromatic group. The stilbene compound may be incorporated into a photoconducting layer of an electrophotographic photoconductor as a charge transporting material. A process for the production of the stilbene compound is also disclosed.
    Type: Grant
    Filed: April 5, 1995
    Date of Patent: June 24, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Chiaki Tanaka, Masaomi Sasaki, Tomoyuki Shimada
  • Patent number: 5631404
    Abstract: An electrophotographic photoconductor includes an electroconductive support and a photoconductive layer formed thereon containing a diamine compound represented by formula (I): ##STR1## wherein R.sup.1, R.sup.2, and R.sup.3 each is independently a substituted or unsubstituted alkyl group or aryl group; R.sup.4 is hydrogen, an alkyl group or an alkoxyl group; n is an integer of 1 to 3; and ##STR2## is a substituted or unsubstituted bivalent arylene group or a bivalent heterocyclic group. This diamine compound is useful as a photoconductive material for electrophotographic photoconductors.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: May 20, 1997
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Mitsutoshi Anzai, Yasuo Murakami, Atsushi Takesue, Masaomi Sasaki, Tomoyuki Shimada, Tamotsu Aruga, Masafumi Ohta
  • Patent number: 5623062
    Abstract: An electrophotographic photoconductor is disclosed, which comprises an electroconductive support and a photoconductive layer formed thereon comprising a bisazo pigment having the formula (I) serving as a charge generating material: ##STR1## wherein Ar represents a residual group of a coupler represented by ArH selected from the group consisting of: an aromatic hydrocarbon compound having a hydroxyl group, a heterocyclic compound having a hydroxyl group, an aromatic hydrocarbon compound having an amino group, a heterocyclic compound having an amino group, an aromatic hydrocarbon compound having a hydroxyl group and an amino group, a heterocyclic compound having a hydroxyl group and an amino group, an aliphatic compound having an enolic ketone group, and an aromatic hydrocarbon compound having an enolic ketone group. Further, charge generating materials and novel bisazo pigments for use in the electrophotographic photoconductor are disclosed.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: April 22, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaomi Sasaki, Tomoyuki Shimada
  • Patent number: 5616801
    Abstract: Charge transporting materials having general formula (I): ##STR1## wherein R.sup.1 represents hydrogen; an unsubstituted or substituted alkyl group; an alkoxyl group having 1 to 4 carbon atoms; a thioalkoxyl group having 1 to 4 carbon atoms; an aryloxy group; an aralkyl group; a nitro group; an unsubstituted or substituted aryl group; a halogen; an amino group; an unsubstituted or substituted dialkylamino group; R.sup.2 represents hydrogen; an unsubstituted or substituted alkyl group; an alkoxyl group having 1 to 4 carbon atoms; or a halogen; R.sup.3 represents hydrogen; an alkyl group having 1 to 4 carbon atoms; an alkoxyl group having 1 to 4 carbon atoms; a halogen; a dialkylamino group; an amino group; a thioalkoxyl group having 1 to 4 carbon atoms; an aryloxy group; a methylenedioxy group; an aralkyl group; or an unsubstituted or substituted aryl group; represents R.sup.
    Type: Grant
    Filed: October 25, 1994
    Date of Patent: April 1, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Mitsuru Hashimoto, Tamotsu Aruga
  • Patent number: 5616805
    Abstract: A pyrenylamine derivative having an unsaturated bond formula (I), which can be employed as an organic photoconductive material for use in electrophotography: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, W, l, m, n, j and k are specifically defined in the specification, an aldehyde compound of formula (II), which is an intermediate for preparing the pyrenylamine derivative: ##STR2## and methods of producing the pyrenylamine derivative and the aldehyde compound are disclosed.
    Type: Grant
    Filed: May 11, 1995
    Date of Patent: April 1, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Chiaki Tanaka, Masaomi Sasaki, Tamotsu Aruga, Tomoyuki Shimada, Hiroshi Adachi
  • Patent number: 5608010
    Abstract: An electrophotographic photoconductor is composed of a substrate and a photoconductive layer formed thereon. The photoconductive layer is composed of a polymer including an acrylic acid ester moiety of formula (I) as repeat unit: ##STR1## wherein R.sup.1 represents hydrogen or a methyl group; R.sup.2, R.sup.3, and R.sup.4 each represent an alkyl group having 1 to 4 carbon atoms, a benzyl group, a phenyl group, a phenoxyl group, chlorine or bromine; n is an integer of 1 to 4; m is 0 to 1; and k is 0 or 1.The polymer and the monomer from which the polymer is prepared are synthesized.
    Type: Grant
    Filed: August 7, 1995
    Date of Patent: March 4, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Tamura, Toshio Fukagai, Naoshi Mishima, Masaomi Sasaki
  • Patent number: 5604065
    Abstract: An electrophotographic photoconductor includes an electroconductive substrate, and a photoconductive layer formed thereon containing at least one tertiary amine compound of formula (I) as an effective component: ##STR1## wherein Ar.sup.1 and Ar.sup.3 each is an aryl group which may have a substituent; Ar.sup.2 is a bivalent group of a carbocyclic aromatic compound or a bivalent group of a heterocyclic compound; R.sup.1 is a hydrogen atom, an alkyl group which may have a substituent or an alkoxyl group which may have a substituent; and R.sup.2 is a hydrogen atom, an alkyl group which may have a substituent or an aryl group which may have a substituent. A novel triphenylamine compound for use in the electrophotographic photoconductor is provided.
    Type: Grant
    Filed: September 14, 1995
    Date of Patent: February 18, 1997
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Tamotsu Aruga, Masafumi Ohta, Mitsutoshi Anzai, Akihiro Imai
  • Patent number: 5599995
    Abstract: An electrophotographic photoconductor comprises an electroconductive substrate and a photoconductive layer formed thereon comprising as an effective component at least one pyrenylamine derivative of formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, W, j, k, l, m and n are specifically defined in the specification. Furthermore, a novel pyrenylamine derivative for use in the above electrophotographic photoconductor, an aldehyde compound, which is an intermediate for producing the pyrenylamine derivative, and methods of preparing the pyrenylamine derivative and the aldehyde compound are disclosed.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: February 4, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Chiaki Tanaka, Masaomi Sasaki, Tamotsu Aruga, Tomoyuki Shimada, Hiroshi Adachi
  • Patent number: 5587516
    Abstract: An electrophotographic photoconductor comprises an electroconductive substrate and a photoconductive layer formed thereon comprising as an effective component at least one pyrenylamine derivative of formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, W, j, k, l, m and n are specifically defined in the specification. Furthermore, a novel pyrenylamine derivative for use in the above electrophotographic photoconductor, an aldehyde compound, which is an intermediate for producing the pyrenylamine derivative, and methods of preparing the pyrenylamine derivative and the aldehyde compound are disclosed.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: December 24, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Chiaki Tanaka, Masaomi Sasaki, Tamotsu Aruga, Tomoyuki Shimada, Hiroshi Adachi
  • Patent number: 5578405
    Abstract: An electrophotographic photoconductor includes an electroconductive support and a single-layered photoconductive layer formed thereon, containing a charge transporting material, a binder resin, and a simultaneously pulverized mixture including at least one disazo pigment of formula (1) and at least one trisazo pigment of formula (2), which is obtained by simultaneously pulverizing those azo pigments: ##STR1## wherein R.sup.1 and R.sup.2 each is hydrogen, a halogen atom, trifluoromethyl group, nitro group or cyano group; R.sup.3 is hydrogen, chlorine, fluorine, iodine, bromine, nitro group or cyano group; and Ar.sup.1, Ar.sup.2 and Ar.sup.3 each is a coupler radical, which may be the same or different.
    Type: Grant
    Filed: October 14, 1994
    Date of Patent: November 26, 1996
    Assignee: Ricoh Company
    Inventors: Takaaki Ikegami, Eiji Kurimoto, Takashi Rokutanzono, Katsuichi Ohta, Masaomi Sasaki, Yasuo Suzuki, Kaoru Tadokoro, Megumi Kawahara, Masayuki Koyano
  • Patent number: 5576132
    Abstract: An electrophotographic photoconductor comprises an electroconductive substrate and a photoconductive layer formed thereon comprising as an effective component at least one pyrenylamine derivative of formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, W, j, k, l, m and n are specifically defined in the specification. Furthermore, a novel pyrenylamine derivative for use in the above electrophotographic photoconductor, an aldehyde compound, which is an intermediate for producing the pyrenylamine derivative, and methods of preparing the pyrenylamine derivative and the aldehyde compound are disclosed.
    Type: Grant
    Filed: April 24, 1995
    Date of Patent: November 19, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Chiaki Tanaka, Masaomi Sasaki, Tamotsu Aruga, Tomoyuki Shimada, Hiroshi Adachi
  • Patent number: 5569800
    Abstract: An electrophotographic photoconductor which is composed of an electroconductive support and a photoconductive layer formed thereon comprising a novel pyrene-ring-containing olefin compound having formula [I]: ##STR1## wherein R.sup.1 and R.sup.2 each represent hydrogen or an alkyl group which may have a substituent; Y is an aliphatic hydrocarbon group which may have a substituent, a cyclic hydrocarbon group which may have a substituent, or an aromatic group which may have a substituent; n is an integer of 0 or 1, and m is an integer of 1 to 3, provided that when n is 0, m is 1, R.sup.1 is hydrogen, and Y is an aromatic group with a substituent ##STR2## R.sup.2 and R.sup.3 each represent hydrogen, and Y and R.sup.1 may be bonded to form a ring, a method of synthesizing the pyrene-ring-containing olefin compound and an intermediate therefor are disclosed.
    Type: Grant
    Filed: May 2, 1995
    Date of Patent: October 29, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Tamotsu Aruga, Masaomi Sasaki, Tomoyuki Shimada, Hiroshi Adachi
  • Patent number: 5550293
    Abstract: An electrophotographic photoconductor comprising an electroconductive support, and a photoconductive layer formed thereon comprising at least one tertiary amine compound having a condensed polycyclic hydrocarbon group of formula (I): ##STR1## wherein A.sup.1 and A.sup.2 each independently represent an unsubstituted or substituted alkyl group or aryl group, and Ar represents an unsubstituted or substituted condensed polycyclic hydrocarbon group. Furthermore, novel tertiary amine compounds having a condensed polycyclic hydrocarbon group are disclosed.
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: August 27, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Tamotsu Aruga
  • Patent number: 5547792
    Abstract: An electrophotographic photoconductor having an electroconductive support and a photoconductive layer formed thereon containing as a photoconductive material at least one carbonate compound of formula (I): ##STR1## wherein R.sup.1 and R.sup.2 each is hydrogen, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a condensed polycyclic group; Y is a bivalent arylene group which may have a substituent, ##STR2## in which Ar.sup.1 and Ar.sup.2 each is an arylene group which may have a substituent, R.sup.3 and R.sup.4 each is hydrogen, an alkyl group which may have a substituent or an aryl group which may have a substituent, and l is an integer of 1 or 2; and R.sup.1 and R.sup.2, or R.sup.1 and Y may independently form a ring; X is an alkyl group which may have a substituent or an aryl group which may have a substituent; m is an integer of 0 or 1; and n is an integer of 0 to 6.
    Type: Grant
    Filed: June 15, 1994
    Date of Patent: August 20, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Chiaki Tanaka
  • Patent number: 5492784
    Abstract: A positively-chargeable single-layered type organic electrophotographic photoconductor composed of an electroconductive support and an organic single-layered photoconductive layer containing a charge generating material, an organic positive hole transporting material and an organic acceptor compound which are dispersed in a matrix binder agent, with the relationship of the oxidation potential (E.sub.ox) of the charge generating material.ltoreq.the oxidation potential (E.sub.ox) of the organic positive hole transporting material being satisfied.
    Type: Grant
    Filed: August 6, 1993
    Date of Patent: February 20, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Masao Yoshikawa, Masayuki Shoshi, Tetsuro Suzuki, Masakatsu Shimoda, Kaoru Teramura, Megumi Kawahara, Akio Kojima, Masaomi Sasaki, Masafumi Ohta
  • Patent number: 5489495
    Abstract: An electrophotographic photoconductor includes an electroconductive support and a photoconductive layer formed thereon containing a diamine compound represented by formula (I): ##STR1## wherein R.sup.1, R.sup.2, and R.sup.3 each is independently a substituted or unsubstituted alkyl group or aryl group; R.sup.4 is hydrogen, an alkyl group or an alkoxyl group; n is an integer of 1 to 3; and ##STR2## is a substituted or unsubstituted bivalent arylene group or a bivalent heterocyclic group. This diamine compound is useful as a photoconductive material for electrophotographic photoconductors.
    Type: Grant
    Filed: October 20, 1994
    Date of Patent: February 6, 1996
    Assignees: Richoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Mitsutoshi Anzai, Yasuo Murakami, Atsushi Takesue, Masaomi Sasaki, Tomoyuki Shimada, Tamotsu Aruga, Masafumi Ohta
  • Patent number: 5488137
    Abstract: An electrophotographic photoconductor is composed of a substrate and a photoconductive layer formed thereon. The photoconductive layer is composed of a polymer including an acrylic acid ester moiety of formula (I) as repeat unit: ##STR1## wherein R.sup.1 represents hydrogen or a methyl group; R.sup.2, R.sup.3, and R.sup.4 each represent an alkyl group having 1 to 4 carbon atoms, a benzyl group, a phenyl group, a phenoxyl group, chlorine or bromine; n is an integer of 1 to 4; m is 0 or 1; and k is 0 or 1.The polymer and the monomer from which the polymer is prepared are synthesized.
    Type: Grant
    Filed: March 22, 1994
    Date of Patent: January 30, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Tamura, Toshio Fukagai, Naoshi Mishima, Masaomi Sasaki
  • Patent number: 5488164
    Abstract: An electrophotographic photoconductor comprising an electroconductive support, and a photoconductive layer formed thereon comprising at least one tertiary amine compound having a condensed polycyclic hydrocarbon group of formula (I): ##STR1## wherein A.sup.1 and A.sup.2 each independently represent an unsubstituted or substituted alkyl group or aryl group, and Ar represents an unsubstituted or substituted condensed polycyclic hydrocarbon group. Furthermore, novel tertiary amine compounds having a condensed polycyclic hydrocarbon group are disclosed.
    Type: Grant
    Filed: August 15, 1994
    Date of Patent: January 30, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Tamotsu Aruga
  • Patent number: 5480753
    Abstract: An electrophotographic photoconductor is composed of an electroconductive support, and a photoconductive layer formed thereon which contains as a photoconductive material at least one diamine compound having carbonate groups of formula (I): ##STR1## wherein R.sup.1 and R.sup.2 each is hydrogen, an alkyl group, or an aryl group; R.sup.1 and R.sup.2 may form a ring in combination of N bonded thereto; Y is an arylene group, ##STR2## wherein Ar.sup.1 and Ar.sup.2 each is an arylene group, R.sup.3 and R.sup.4 each is hydrogen, an alkyl group, or an aryl group, and l is an integer of 1 or 2; and R.sup.1 and Y may together form a ring, X is an alkylene group, a dialkylene ether group or an arylene group, --Ar.sup.3 -Z-Ar.sup.4 --, wherein Ar.sup.3 and Ar.sup.4 each is an arylene group; Z is an alkylene group, a dialkylene ether group or a cycloalkylidene group, oxygen, sulfur, a vinylene group, m is an integer of 0 or 1; and n is an integer of 0 to 6.
    Type: Grant
    Filed: July 19, 1994
    Date of Patent: January 2, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Chiaki Tanaka
  • Patent number: 5474868
    Abstract: An electrophotographic photoconductor having an electroconductive support and a photoconductive layer formed thereon containing a charge generating material, a charge transporting material and lignin.
    Type: Grant
    Filed: December 22, 1994
    Date of Patent: December 12, 1995
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Adachi, Masaomi Sasaki, Tamotsu Aruga