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: 6066757
    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: January 20, 1998
    Date of Patent: May 23, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Chiaki Tanaka, Masaomi Sasaki, Tomoyuki Shimada
  • Patent number: 6066428
    Abstract: An electrophotographic photoconductor has an electroconductive support, and a photoconductive layer which is formed on the support and contains as an effective component an aromatic polycarbonate resin having a structural unit of formula (I), or the structural unit of formula (I) and a structural unit of formula (II): ##STR1## wherein Ar.sup.1 to Ar.sup.5, R.sup.1, and X are as specified in the specification.
    Type: Grant
    Filed: June 19, 1998
    Date of Patent: May 23, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Akira Katayama, Masaomi Sasaki, Katsukiyo Nagai, Chiaki Tanaka, Shinichi Kawamura, Tetsuro Suzuki, Susumu Suzuka, Katsuhiro Morooka
  • Patent number: 6045959
    Abstract: An electrophotographic photoconductor includes an electroconductive support, and a photoconductive layer formed thereon containing as an effective component an aromatic polycarbonate resin having a structural unit of formula (I), or in combination with a structural unit of formula (II): ##STR1## wherein R, R.sup.1, and X are as specified in the specification.
    Type: Grant
    Filed: April 15, 1998
    Date of Patent: April 4, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Akira Katayama, Masaomi Sasaki, Katsukiyo Nagai, Chiaki Tanaka, Shinichi Kawamura, Susumu Suzuka, Katsuhiro Morooka
  • Patent number: 6027846
    Abstract: An electrophotographic photoconductor includes an electroconductive support, and a photoconductive layer formed thereon containing as an effective component an aromatic polycarbonate resin having a structural unit of formula (I), two structural units of formulae (I) and (II), or a repeat unit of formula (III): ##STR1## wherein Ar.sup.1 to Ar.sup.7, Y, X, and n are as specified in the specification.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: February 22, 2000
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Masafumi Ohta, Akihiro Imai, Mitsutoshi Anzai, Tamotsu Aruga, Kazukiyo Nagai, Katsuhiro Morooka
  • Patent number: 6018014
    Abstract: An aromatic polycarbonate containing a structural unit of the formula: ##STR1## wherein R.sup.1 is a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, Ar.sup.1 is a substituted or unsubstituted aryl group and Ar.sup.2 and Ar.sup.3 are independently a substituted or unsubstituted arylene group. The aromatic polycarbonate is capable of transferring charges and is used for forming a photosensitive layer of an electrophotographic photosensitive medium.
    Type: Grant
    Filed: April 10, 1998
    Date of Patent: January 25, 2000
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Kazukiyo Nagai, Masaomi Sasaki, Hiroshi Tamura, Tetsuro Suzuki, Tomoyuki Shimada, Chihaya Adachi, Chiaki Tanaka, Nozomu Tamoto, Kouji Kishida, Akira Katayama, Mitsutoshi Anzai, Akihiro Imai
  • Patent number: 5981124
    Abstract: An electrophotographic photoconductor includes an electroconductive support and a photoconductive layer formed thereon which contains a compound having a charge generating moiety and a charge transporting moiety in the molecule thereof. As such a compound for use in the electrophotographic photoconductor, various compounds having a charge generating moiety derived from an azo compound and a charge transporting moiety derived from a triarylamine compound are proposed. Bisazo and trisazo compounds serving as such compounds are also proposed, together with intermediates for producing the bisazo and trisazo compounds.
    Type: Grant
    Filed: November 24, 1995
    Date of Patent: November 9, 1999
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Chiaki Tanaka
  • Patent number: 5976746
    Abstract: An electrophotographic photoconductor has an electroconductive support, and a photoconductive layer which is formed thereon and contains as an effective component an aromatic polycarbonate resin having a structural unit of formula (1), two structural units of formula (1) and (2), or a repeat unit of formula (3): ##STR1## wherein R.sup.1 and R.sup.z Ar.sup.1 to Ar.sup.6, X, Y, s and n are as specified in the specification. The above-mentioned aromatic polycarbonate resin is provided with charge transporting properties.
    Type: Grant
    Filed: June 11, 1998
    Date of Patent: November 2, 1999
    Assignee: Ricoh Company, Ltd.
    Inventors: Chiaki Tanaka, Masaomi Sasaki, Katsukiyo Nagai, Shinichi Kawamura, Susumu Suzuka, Katsuhiro Morooka
  • Patent number: 5942363
    Abstract: An electrophotographic photoconductor includes an electroconductive support, and a photoconductive layer formed thereon containing as an effective component an aromatic polycarbonate resin having a repeat unit of formula (I), or two repeat units of formulae (II) and (III): wherein Ar.sup.1 to Ar.sup.5, X, n, k and j are as specified in the specification.
    Type: Grant
    Filed: December 16, 1996
    Date of Patent: August 24, 1999
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Chiaki Tanaka, Nozomu Tamoto, Masaomi Sasaki, Kazukiyo Nagai, Tomoyuki Shimada, Chihaya Adachi, Akira Katayama, Mitsutoshi Anzai, Katsuhiro Morooka
  • Patent number: 5910561
    Abstract: An electrophotographic photoconductor includes an electroconductive support, and a photoconductive layer formed thereon containing as an effective component an aromatic polycarbonate resin having a repeat unit of formula (I), or two repeat units of formulae (II) and (III): ##STR1## wherein Ar.sup.1 to Ar.sup.6, X, n, k and j are as specified in the specification.
    Type: Grant
    Filed: May 26, 1998
    Date of Patent: June 8, 1999
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Chihaya Adachi, Masaomi Sasaki, Kazukiyo Nagai, Tomoyuki Shimada, Chiaki Tanaka, Nozomu Tamoto, Akira Katayama, Mitsutoshi Anzai, Akihiro Imai, Katsuhiro Morooka
  • Patent number: 5863683
    Abstract: An electrophotographic photoconductor composed of an electroconductive support and a photoconductive layer formed thereon, which contains as a charge generating material an azo pigment subjected to a salt milling process.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: January 26, 1999
    Assignee: Ricoh Company, Ltd.
    Inventors: Katsuichi Ohta, Masaomi Sasaki, Tamotsu Aruga
  • Patent number: 5846680
    Abstract: An electrophotographic photoconductor includes an electroconductive support, and a photoconductive layer formed thereon containing as an effective component an aromatic polycarbonate resin having a repeat unit of formula (I), or two repeat units of formulae (II) and (III): ##STR1## wherein Ar.sup.1 to Ar.sup.6, X, n, k and j are as specified in the specification.
    Type: Grant
    Filed: December 19, 1996
    Date of Patent: December 8, 1998
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Chihaya Adachi, Masaomi Sasaki, Kazukiyo Nagai, Tomoyuki Shimada, Chiaki Tanaka, Nozomu Tamoto, Akira Katayama, Mitsutoshi Anzai, Akihiro Imai, Katsuhiro Morooka
  • Patent number: 5840454
    Abstract: An aromatic polycarbonate containing a structural unit of the formula: ##STR1## wherein R.sup.1 is a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, Ar.sup.1 is a substituted or unsubstituted aryl group and Ar.sup.2 and Ar.sup.3 are independently a substituted or unsubstituted arylene group. The aromatic polycarbonate is capable of transferring charges and is used for forming a photosensitive layer of an electrophotographic photosensitive medium.
    Type: Grant
    Filed: June 20, 1996
    Date of Patent: November 24, 1998
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Kazukiyo Nagai, Masaomi Sasaki, Hiroshi Tamura, Tetsuro Suzuki, Tomoyuki Shimada, Chihaya Adachi, Chiaki Tanaka, Nozomu Tamoto, Kouji Kishida, Akira Katayama, Mitsutoshi Anzai, Akihiro Imai
  • Patent number: 5830980
    Abstract: An electrophotographic photoconductor includes an electroconductive support, and a photoconductive layer formed thereon, containing a novel aromatic polycarbonate resin having a repeat unit of formula (I): ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each is an alkyl group which may have a substituent, or a halogen atom; R.sup.4 is a hydrogen atom, or an alkyl group which may have a substituent; Ar.sup.1 and Ar.sup.2 each is an aromatic hydrocarbon group which may have a substituent; l, m and n each is an integer of 0 to 4; k is an integer of 5 to 5,000; and X is a bivalent aliphatic group, a bivalent cyclic aliphatic group, or ##STR2## in which R.sup.5 and R.sup.6 each is an alkyl group which may have a substituent, a halogen atom, or an aromatic hydrocarbon group; p and q each is an integer of 0 to 4; and r is 0 or 1, and when r is 1, Y is a straight-chain, branched or cyclic alkylene group having 1 to 12 carbon atoms, --O--, --S--, --SO--, --SO.sub.2 --, or --C(O)--.
    Type: Grant
    Filed: October 23, 1997
    Date of Patent: November 3, 1998
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Mitsutoshi Anzai, Akihiro Imai, Masaomi Sasaki, Hiroshi Tamura, Tomoyuki Shimada, Tetsuro Suzuki, Masafumi Ohta
  • Patent number: 5808155
    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 or 0 or 1; and n is an integer of 0 to 6.
    Type: Grant
    Filed: March 6, 1997
    Date of Patent: September 15, 1998
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Chiaki Tanaka
  • Patent number: 5789128
    Abstract: An electrophotographic photoconductor includes an electroconductive support, and a photoconductive layer formed thereon containing as an effective component an aromatic polycarbonate resin having a repeat unit of formula (I), or two repeat units of formulae (II) and (III): ##STR1## wherein Ar.sup.1 to Ar.sup.6, X, n, k and j are as specified in the specification.
    Type: Grant
    Filed: December 16, 1996
    Date of Patent: August 4, 1998
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Chihaya Adachi, Masaomi Sasaki, Kazukiyo Nagai, Tomoyuki Shimada, Chiaki Tanaka, Nozomu Tamoto, Akira Katayama, Mitsutoshi Anzai, Akihiro Imai, Katsuhiro Morooka
  • Patent number: 5747204
    Abstract: An electrophotographic photoconductor includes an electroconductive support, and a photoconductive layer formed thereon, containing a novel aromatic polycarbonate resin having a repeat unit of formula (I): ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each is an alkyl group which may have a substituent, or a halogen atom; R.sup.4 is a hydrogen atom, or an alkyl group which may have a substituent; Ar.sup.1 and Ar.sup.2 each is an aromatic hydrocarbon group which may have a substituent; l, m and n each is an integer of 0 to 4; k is an integer of 5 to 5,000; and X is a bivalent aliphatic group, a bivalent cyclic aliphatic group, or ##STR2## in which R.sup.5 and R.sup.6 each is an alkyl group which may have a substituent, a halogen atom, or an aromatic hydrocarbon group; p and q each is an integer of 0 to 4; and r is 0 or 1, and when r is 1, Y is a straight-chain, branched or cyclic alkylene group having 1 to 12 carbon atoms, --O--, --S--, --SO--, --SO.sub.2 --, or --C(O)--.
    Type: Grant
    Filed: June 18, 1996
    Date of Patent: May 5, 1998
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Mitsutoshi Anzai, Akihiro Imai, Masaomi Sasaki, Hiroshi Tamura, Tomoyuki Shimada, Tetsuro Suzuki, Masafumi Ohta
  • Patent number: 5723243
    Abstract: An electrophotographic photoconductor includes an electroconductive support, and a photoconductive layer formed thereon containing as an effective component an aromatic polycarbonate resin having a repeat unit of formula (I), or two repeat units of formula (II) and formula (III): ##STR1## wherein n, Ar.sup.1, Ar.sup.2, Ar.sup.3, R.sup.1, R.sup.2 and X are as specified in the specification, ##STR2## wherein k and j are also as specified in the specification.
    Type: Grant
    Filed: May 16, 1996
    Date of Patent: March 3, 1998
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Masaomi Sasaki, Hiroshi Tamura, Tomoyuki Shimada, Tetsuro Suzuki, Chiaki Tanaka, Kouji Kishida, Akira Katayama, Kazukiyo Nagai, Chihaya Adachi, Nozomu Tamoto, Mitsutoshi Anzai, Akihiro Imai
  • Patent number: 5672728
    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: July 11, 1996
    Date of Patent: September 30, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Chiaki Tanaka, Masaomi Sasaki, Tamotsu Aruga, Tomoyuki Shimada, Hiroshi Adachi
  • Patent number: 5672756
    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 carboxylic 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 alkoxy 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: July 25, 1996
    Date of Patent: September 30, 1997
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Tamotsu Aruga, Masafumi Ohta, Mitsutoshi Anzai, Akihiro Imai
  • Patent number: 5663407
    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 1 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: April 17, 1995
    Date of Patent: September 2, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Chiaki Tanaka