Patents by Inventor Masaki Okubo

Masaki Okubo 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: 7709172
    Abstract: The present invention discloses an oxidized mixed cyclic phenol sulfide which is a mixture of the oxidized cyclic phenol sulfide wherein m is 8 and the oxidized cyclic phenol sulfide wherein m is an integer other than 8, the oxidized cyclic phenol sulfide being represented by the following formula (1): wherein R is a straight or branched alkyl group having 1 to 6 carbon atoms, m is an integer from 4 to 9, and n is 1 or 2; or an oxidized cyclic phenol sulfide of formula (1) wherein m is 8. The present invention also discloses a charge control agent which comprises the above sulfide(s) as the active ingredient; and a toner which comprises the charge control agent, a coloring agent and a binder resin. This charge control agent is particularly useful for color toners, and it speeds up charging risetime, and has a high charge amount and charging characteristics excellent in environmental stability. Further, the charge control agent is safe since it does not have any problem with the waste regulations.
    Type: Grant
    Filed: October 10, 2008
    Date of Patent: May 4, 2010
    Assignee: Hodogaya Chemical Co., Ltd.
    Inventors: Masateru Yasumura, Masami Ito, Naohiro Tarumoto, Yoshikazu Aoki, Masafumi Umekawa, Masaki Okubo, Hideyuki Otsuka, Jun Watanabe
  • Publication number: 20090239169
    Abstract: The present invention discloses an oxidized mixed cyclic phenol sulfide which is a mixture of the oxidized cyclic phenol sulfide wherein m is 8 and the oxidized cyclic phenol sulfide wherein m is an integer other than 8, the oxidized cyclic phenol sulfide being represented by the following formula (1): wherein R is a straight or branched alkyl group having 1 to 6 carbon atoms, m is an integer from 4 to 9, and n is 1 or 2; or an oxidized cyclic phenol sulfide of formula (1) wherein m is 8. The present invention also discloses a charge control agent which comprises the above sulfide(s) as the active ingredient; and a toner which comprises the charge control agent, a coloring agent and a binder resin. This charge control agent is particularly useful for color toners, and it speeds up charging risetime, and has a high charge amount and charging characteristics excellent in environmental stability. Further, the charge control agent is safe since it does not have any problem with the waste regulations.
    Type: Application
    Filed: June 9, 2009
    Publication date: September 24, 2009
    Applicant: Hodogaya Chemical Co., Ltd.
    Inventors: Masateru Yasumura, Masami Ito, Naohiro Tarumoto, Yoshikazu Aoki, Masafumi Umekawa, Masaki Okubo, Hideyuki Otsuka, Jun Watanabe
  • Publication number: 20090104554
    Abstract: The present invention provides a modified charge control agent composition exhibiting a high charge-imparting effect, and an electrostatic image developing toner containing such a charge control agent composition and having a high electrostatic charge amount and an environmental stability. A composition comprising a metal compound (A) of aromatic hydroxycarboxylic acid having an aromatic hydroxycarboxylic acid bonded with a metal atom selected from a zirconium atom, a calcium atom, an aluminum atom, a chromium atom, a boron atom and a zinc atom via at least any of ionic bond, covalent bond and coordinate bond; and at least one inorganic pigment (B), wherein the pigment (B) is contained in an amount of from 1 to 20 parts by mass in 100 parts by mass of the composition.
    Type: Application
    Filed: April 16, 2007
    Publication date: April 23, 2009
    Inventors: Hideyuki Otsuka, Masaki Okubo, Osamu Mukudai
  • Publication number: 20090042120
    Abstract: The present invention discloses an oxidized mixed cyclic phenol sulfide which is a mixture of the oxidized cyclic phenol sulfide wherein in is 8 and the oxidized cyclic phenol sulfide wherein m is an integer other than 8, the oxidized cyclic phenol sulfide being represented by the following formula (1): wherein R is a straight or branched alkyl group having 1 to 6 carbon atoms, m is an integer from 4 to 9, and n is 1 or 2; or an oxidized cyclic phenol sulfide of formula (1) wherein m is 8. The present invention also discloses a charge control agent which comprises the above sulfide(s) as the active ingredient; and a toner which comprises the charge control agent, a coloring agent and a binder resin. This charge control agent is particularly useful for color toners, and it speeds up charging risetime, and has a high charge amount and charging characteristics excellent in environmental stability. Further, the charge control agent is safe since it does not have any problem with the waste regulations.
    Type: Application
    Filed: October 10, 2008
    Publication date: February 12, 2009
    Applicant: Hodogaya Chemical Co., Ltd.
    Inventors: Masateru Yasumura, Masami Ito, Naohiro Tarumoto, Yoshikazu Aoki, Masafumi Umekawa, Masaki Okubo, Hideyuki Otsuka, Jun Watanabe
  • Publication number: 20090035678
    Abstract: The present invention discloses a mixed cyclic phenol sulfide which is a mixture of the cyclic phenol sulfide wherein m is 8 and the cyclic phenol sulfide wherein m is an integer other than 8, the cyclic phenol sulfide being represented by the following formula (1): wherein R is a straight or branched alkyl group having 1 to 6 carbon atoms, and m is an integer from 4 to 9; or a cyclic phenol sulfide of formula (1) wherein m is 8. The present invention also discloses a charge control agent which comprises the above sulfide(s) as the active ingredient; and a toner which comprises the charge control agent, a coloring agent and a binder resin. This charge control agent is particularly useful for color toners, and it speeds up charging risetime, and has a high charge amount and charging characteristics excellent in the environmental stability. Further, the charge control agent is safe since it does not have any problem with the waste regulations.
    Type: Application
    Filed: September 29, 2008
    Publication date: February 5, 2009
    Applicant: HODOGAYA CHEMICAL CO., LTD.
    Inventors: Masateru Yasumura, Masami Ito, Naohiro Tarumoto, Yoshikazu Aoki, Masafumi Umekawa, Masaki Okubo, Hideyuki Otsuka, Jun Watanabe
  • Patent number: 7402369
    Abstract: The present invention is to provide a charge controlling agent and negatively chargeable toner that do not contain any toxic metal, are essentially free from the risk of evoking ignition or explosion, and can exhibit a high charge amount and rapid initial increase in charging. The charge controlling agent is a mono azo iron complex compound represented by Formula (1): wherein J represents H, alkali metal, ammonium, or alkyl ammonium, or two or more of those elements in combination.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: July 22, 2008
    Assignee: Hodogaya Chemical Co., Ltd.
    Inventors: Masaki Okubo, Hideyuki Otsuka, Kazuo Nemoto, Masami Ito, Eisuke Yamada
  • Publication number: 20070020547
    Abstract: The present invention is to provide a charge controlling agent and negatively chargeable toner that do not contain any toxic metal, are essentially free from the risk of evoking ignition or explosion, and can exhibit a high charge amount and rapid initial increase in charging. The charge controlling agent is a mono azo iron complex compound represented by Formula (1): wherein J represents H, alkali metal, ammonium, or alkyl ammonium, or two or more of those elements in combination.
    Type: Application
    Filed: September 29, 2006
    Publication date: January 25, 2007
    Inventors: Masaki Okubo, Hideyuki Otsuka, Kazuo Nemoto, Masami Ito, Eisuke Yamada
  • Patent number: 7094512
    Abstract: An electrophotographic printing method which comprises using a charge controlling agent containing a monoazo iron complex compound of the formula (1) as an effective component, wherein A1, A2, B1 and B2 are respectively independently H, an alkyl group or a halogen atom, J is H, an alkali metal, NH4 or an alkylammonium, they may be two or more kinds, X1 and X2 are respectively independently H, an alkyl group or a halogen atom, and Y1 and Y2 are respectively independently H, an alkyl group or an aromatic group which may have a substituent, provided that a case in which A1, A2, B1, B2, X1, X2, Y1, and Y2 are hydrogen at the same time is excluded.
    Type: Grant
    Filed: November 18, 2003
    Date of Patent: August 22, 2006
    Assignee: Hodogaya Chemical Co., Ltd.
    Inventors: Hideyuki Otsuka, Kazuo Nemoto, Shinji Otani, Noriyuki Suzuki, Eisuke Yamada, Masaki Okubo
  • Publication number: 20040191660
    Abstract: An electrophotographic printing method which comprises using a charge controlling agent containing a monoazo iron complex compound of the formula (1) as an effective component, 1
    Type: Application
    Filed: November 18, 2003
    Publication date: September 30, 2004
    Applicant: Hodogaya Chemical Co., Ltd.
    Inventors: Hideyuki Otsuka, Kazuo Nemoto, Shinji Otani, Noriyuki Suzuki, Eisuke Yamada, Masaki Okubo
  • Patent number: 6627368
    Abstract: A toner composition, comprising an organometal complex compound having the formula (1), which has an electroconductivity of at most 110 &mgr;S/cm when dispersed in ion-exchanged water in an amount of 1 wt %: wherein Ar is an aryl group selected from the group consisting of a substituted or unsubstituted phenyl group and a substituted or unsubstituted naphthyl group, X and Y are —S—, —O—, —CO—, —COO—, —NH— or —NR—, wherein R is C1-4 alkyl; K+ is hydrogen ion, lithium ion, sodium ion, potassium ion, ammonium ion, organoammonium or a mixture thereof; m is the number of azo compound groups coordinated to Fe and is 1, 2, 3 or 6; p is the valence of Fe; n is 1, 2 or 4; and q is 0 or an integer, as a component of an electrostatic image developing non-magnetic toner.
    Type: Grant
    Filed: December 6, 2000
    Date of Patent: September 30, 2003
    Assignee: Hodagaya Chemical Co., Ltd.
    Inventors: Masaki Okubo, Hiroshi Nanaumi, Masataka Sawano
  • Publication number: 20010004667
    Abstract: A organic metal complex compound represented by the following formula (1), which has an electroconductivity of at most 110 &mgr;S/cm when dispersed in ion-exchanged water in an amount of 1 wt %: 1
    Type: Application
    Filed: December 6, 2000
    Publication date: June 21, 2001
    Applicant: Hodogaya Chemical Co.,Ltd.
    Inventors: Masaki Okubo, Hiroshi Nanaumi, Masataka Sawano
  • Patent number: 5312707
    Abstract: An electrophotographic photoconductor is composed of an electroconductive substrate and a photoconductive layer formed thereon including a diamine compound of formula (I): ##STR1## wherein R.sup.1 represents an alkyl group having 1 to 4 carbon atoms, or an aryl group; R.sup.2 represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or an alkoxyl group having 1 to 4 carbon atoms; n is an integer of 1 to 3; and ##STR2## represents an arylene group or a bivalent group of a heterocyclic compound. A diamine compound for use in the electrophotographic photoconductor is also disclosed.
    Type: Grant
    Filed: September 30, 1992
    Date of Patent: May 17, 1994
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Masafumi Ota, Masaomi Sasaki, Tamotsu Aruga, Tomoyuki Shimada, Mitsutoshi Anzai, Masaki Okubo