Patents by Inventor Kazu Niwa
Kazu Niwa 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: 10691037Abstract: To provide a method for producing a rubber composition which gives a cross-linked rubber which has a low volume resistivity value, which is low in hardness, and which is kept down in contamination of the photoconductor when used as a conductive member. A production method of a rubber composition comprising a step of mixing a polyether rubber which is dissolved in a solvent at 0.1 to 30 wt % of concentration and a liquid ethylenically unsaturated nitrile-conjugated diene copolymer rubber in a solution is provided.Type: GrantFiled: November 14, 2018Date of Patent: June 23, 2020Assignees: ZEON CORPORATION, ZEON CHEMICALS L.P.Inventors: Kazu Niwa, Clark Cable
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Publication number: 20190079426Abstract: To provide a method for producing a rubber composition which gives a cross-linked rubber which has a low volume resistivity value, which is low in hardness, and which is kept down in contamination of the photoconductor when used as a conductive member. A production method of a rubber composition comprising a step of mixing a polyether rubber which is dissolved in a solvent at 0.1 to 30 wt % of concentration and a liquid ethylenically unsaturated nitrile-conjugated diene copolymer rubber in a solution is provided.Type: ApplicationFiled: November 14, 2018Publication date: March 14, 2019Applicants: ZEON CORPORATION, ZEON Chemicals L.P.Inventors: Kazu Niwa, Clark Cable
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Patent number: 9771454Abstract: A method of production of a polyether rubber containing units expressed by the following general formula (1) in 0.1 mol % to less than 30 mol % including reacting a polyether rubber containing epihalohydrin monomer units in 0.1 mol % or more and a nitrogen atom-containing aromatic heterocyclic compound by kneading in the presence of an acid acceptor using an extruder-kneader so as to make at least part of halogen atoms forming the epihalohydrin monomer units be substituted by a group containing a cationic nitrogen-containing aromatic heterocyclic structure is provided. (wherein, in the above general formula (1), A+ is a group containing a cationic nitrogen-containing aromatic heterocyclic structure, where the group containing a cationic nitrogen-containing aromatic heterocyclic structure is bonded with a carbon atom at the “2” position shown in the above general formula (1) through a nitrogen atom forming the cationic nitrogen-containing aromatic heterocyclic structure, and X? is any counter anion.Type: GrantFiled: December 25, 2014Date of Patent: September 26, 2017Assignee: ZEON CORPORATIONInventors: Tomoyuki Narita, Kazu Niwa
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Patent number: 9732188Abstract: A method of production of a polyether rubber containing units expressed by the following general formula (1) in 0.1 mol % to less than 30 mol % including reacting a polyether rubber containing epihalohydrin monomer units in 0.1 mol % or more and a nitrogen atom-containing aromatic heterocyclic compound by kneading in the presence of an acid acceptor using an extruder-kneader so as to make at least part of halogen atoms forming the epihalohydrin monomer units be substituted by a group containing a cationic nitrogen-containing aromatic heterocyclic structure is provided. (wherein, in the above general formula (1), A+ is a group containing a cationic nitrogen-containing aromatic heterocyclic structure, where the group containing a cationic nitrogen-containing aromatic heterocyclic structure is bonded with a carbon atom at the “2” position shown in the above general formula (1) through a nitrogen atom forming the cationic nitrogen-containing aromatic heterocyclic structure, and X? is any counter anion.Type: GrantFiled: December 25, 2014Date of Patent: August 15, 2017Assignee: ZEON CORPORATIONInventors: Tomoyuki Narita, Kazu Niwa
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Publication number: 20170029564Abstract: A method of production of a polyether rubber containing units expressed by the following general formula (1) in 0.1 mol % to less than 30 mol % including reacting a polyether rubber containing epihalohydrin monomer units in 0.1 mol % or more and a nitrogen atom-containing aromatic heterocyclic compound by kneading in the presence of an acid acceptor using an extruder-kneader so as to make at least part of halogen atoms forming the epihalohydrin monomer units be substituted by a group containing a cationic nitrogen-containing aromatic heterocyclic structure is provided. (wherein, in the above general formula (1), A+ is a group containing a cationic nitrogen-containing aromatic heterocyclic structure, where the group containing a cationic nitrogen-containing aromatic heterocyclic structure is bonded with a carbon atom at the “2” position shown in the above general formula (1) through a nitrogen atom forming the cationic nitrogen-containing aromatic heterocyclic structure, and X? is any counter anion.Type: ApplicationFiled: December 25, 2014Publication date: February 2, 2017Applicant: ZEON CORPORATIONInventors: Tomoyuki NARITA, Kazu NIWA
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Publication number: 20140097388Abstract: A method for producing a rubber composition which gives a cross-linked rubber which has a low volume resistivity value, which is low in hardness, and which is kept down in contamination of the photoconductor when used as a conductive member is provided, that is, a production method of a rubber composition comprising a step of mixing a polyether rubber which is dissolved in a solvent at 0.1 to 30 wt % of concentration and a liquid ethylenically unsaturated nitrile-conjugated diene copolymer rubber in a solution is provided.Type: ApplicationFiled: October 3, 2013Publication date: April 10, 2014Applicants: ZEON Chemicals L.P., ZEON CORPORATIONInventors: Kazu NIWA, Clark CABLE
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Patent number: 8092969Abstract: A process for forming a full-color image, wherein the 4 color toners each have an apparent viscosity at 105° C. of 50,000 to 300,000 Pa·s and an apparent viscosity at 130° C. of 3,000 to 30,000 Pa·s, and as a color toner arranged at the outermost layer on a transfer medium among the 4 color toners, a toner, in which a maximum peak or a shoulder peak is present between 105° C. and 130° C. in a temperature-logarithmic melt viscosity graph, is used, and as the other color toners arranged at lower layers than the outermost layer, toners, in which neither the maximum peak nor the shoulder peak is present between 105° C. and 130° C., are used.Type: GrantFiled: March 31, 2008Date of Patent: January 10, 2012Assignee: Zeon CorporationInventor: Kazu Niwa
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Publication number: 20080241719Abstract: A process for forming a full-color image, wherein the 4 color toners each have an apparent viscosity at 105° C. of 50,000 to 300,000 Pa·s and an apparent viscosity at 130° C. of 3,000 to 30,000 Pa·s, and as a color toner arranged at the outermost layer on a transfer medium among the 4 color toners, a toner, in which a maximum peak or a shoulder peak is present between 105° C. and 130° C. in a temperature-logarithmic melt viscosity graph, is used, and as the other color toners arranged at lower layers than the outermost layer, toners, in which neither the maximum peak nor the shoulder peak is present between 105° C. and 130° C., are used.Type: ApplicationFiled: March 31, 2008Publication date: October 2, 2008Applicant: ZEON CORPORATIONInventor: Kazu Niwa
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Patent number: 7422833Abstract: A charge control resin composition for positive or negative charge, which is prepared either by mixing and kneading a charge control resin for positive or negative charge with a colorant, or by mixing and kneading the above combination further with a charge control resin for opposite charge or a charge control resin composition for opposite charge; wherein colorant particles are finely dispersed as desired. The resultant mixture is mixed with a polymerizable monomer to obtain polymerizable monomer composition. Then, the polymerizable monomer composition is dispersed or emulsified in an aqueous dispersion medium containing a dispersion stabilizer, and polymerized to obtain a toner.Type: GrantFiled: September 27, 2001Date of Patent: September 9, 2008Assignee: Zeon CorporationInventors: Kazu Niwa, Fuminari Oyama
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Patent number: 7378207Abstract: The invention relates to a magenta toner having magenta-colored resin particles comprising at least a binder resin and a magenta colorant. The magenta pigment is a magenta pigment composed of a combination of C.I. Pigment Red 31 and C.I. Pigment Red 150.Type: GrantFiled: September 5, 2003Date of Patent: May 27, 2008Assignee: Zeon CorporationInventors: Fuminari Oyama, Kazu Niwa
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Publication number: 20050250033Abstract: The invention relates to a magenta toner having magenta-colored resin particles comprising at least a binder resin and a magenta colorant. The magenta pigment is a magenta pigment composed of a combination of C.I. Pigment Red 31 and C.I. Pigment Red 150.Type: ApplicationFiled: September 5, 2003Publication date: November 10, 2005Inventors: Fuminari Oyama, Kazu Niwa
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Patent number: 6887637Abstract: A toner for electrostatic image development, which comprises a binder resin, a colorant and a charge control resin, wherein the charge control resin is a copolymer composed a vinyl monomer unit and a quaternary ammonium salt group-containing (meth)acrylate monomer unit and has a glass transition temperature of 40 to 75° C., and a production process thereof.Type: GrantFiled: February 13, 2001Date of Patent: May 3, 2005Assignee: Zeon CorporationInventor: Kazu Niwa
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Publication number: 20040013961Abstract: A toner comprising a binder resin, a colorant and a charge control resin for positive and/or negative charge, wherein a number of colorant particles having a length of at least 0.2 mm counted in an area of 100 mm×100 mm of a toner having a thickness of 20 mm, which is prepared by melting the toner, being at most 50.Type: ApplicationFiled: March 21, 2003Publication date: January 22, 2004Inventors: Kazu Niwa, Fuminari Oyama
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Patent number: 6562535Abstract: A toner for development of electrostatic images, comprising at least a binder resin, a colorant and a charge control agent, wherein the charge control agent contains a positive charge control resin (A) composed of a polymer having a weight average molecular weight of 1,000 to 100,000 and a functional group which brings positively charging ability, and a negative charge control resin (B) composed of a polymer having a weight average molecular weight of 1,000 to 100,000 and a functional group which brings negatively charging ability. The toner is excellent in flowability, shelf stability and charge properties, and provides images excellent in image quality.Type: GrantFiled: September 25, 2001Date of Patent: May 13, 2003Assignee: Nippon Zeon Co., Ltd.Inventors: Kojiro Masuo, Shuichi Yokoyama, Takuji Kishimoto, Kazu Niwa
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Publication number: 20030027070Abstract: A toner for electrostatic image development, which comprises a binder resin, a colorant and a charge control resin, wherein the charge control resin is a copolymer composed a vinyl monomer unit and a quaternary ammonium salt group-containing (meth)acrylate monomer unit and has a glass transition temperature of 40 to 75° C., and a production process thereof.Type: ApplicationFiled: August 8, 2002Publication date: February 6, 2003Inventor: Kazu Niwa
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Patent number: 6342328Abstract: A toner for development of electrostatic images, comprising at least a binder resin, a colorant and a charge control agent, wherein the charge control agent is a polar resin composed of a copolymer of a vinyl monomer and SO3X (X=H or alkali metal) group-containing (meth)acrylamide and having an SO3X group-containing (meth)acrylamide unit content of 0.1 to 10 wt. % and a weight average molecular weight of 17,000 to 25,000, and a production process of the toner.Type: GrantFiled: September 5, 2000Date of Patent: January 29, 2002Assignee: Nippon Zeon Co., Ltd.Inventors: Takahiro Takasaki, Kazu Niwa, Kojiro Masuo, Kazuhiro Sato