Patents by Inventor Koji Azuma
Koji Azuma 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: 7345098Abstract: A water-based ink comprising an aqueous dispersion of polymer particles made of a water-insoluble vinyl polymer containing a colorant, wherein the water-insoluble vinyl polymer is prepared by polymerizing a monomer composition comprising a specific monomer A such as a monomer A1 represented by the formula (I): wherein R1 is hydrogen or methyl, R2 is hydrogen, alkyl or alkylphenyl, and n is 1 to 30; a monomer having a salt-forming group; and a monomer copolymerizable with the monomer A and the monomer having a salt-forming group. The water-based ink can be suitably used as a water-based ink for inkjet recording and the like.Type: GrantFiled: December 27, 2002Date of Patent: March 18, 2008Assignee: Kao CorporationInventors: Ryuma Mizushima, Isao Tsuru, Koji Azuma, Takehiro Tsutsumi
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Publication number: 20080064786Abstract: The present invention relates to crosslinked core/shell polymer particles containing a pigment which are usable in a water-based ink for ink-jet printing and exhibit excellent optical density and gloss and are prevented from suffering from occurrence of bronzing, wherein the polymer particles each include a core portion and a shell portion which are respectively made of a crosslinked polymer, and a weight ratio of the pigment to the pigment-containing crosslinked core/shell polymer particles [(weight of the pigment/weight of the pigment-containing crosslinked core/shell polymer particles)×100] is from 25 to 75. The present invention further relates to a water dispersion and a water-based ink for ink-jet printing which contain the crosslinked core/shell polymer particles and a process for producing crosslinked polymer particles.Type: ApplicationFiled: September 7, 2007Publication date: March 13, 2008Applicant: Kao CorporationInventors: Nobushige Tanaka, Takehiro Tsutsumi, Koji Azuma
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Publication number: 20070289485Abstract: A water dispersion for inkjet printing which contains polymer particles containing a colorant. The polymer constituting the polymer particles is produced by the copolymerization of a monomer mixture in the presence of a-methylstyrene dimer. The water dispersion for inkjet printing and a water-based ink for inkjet printing containing the water dispersion exhibit excellent jetting properties and a high optical density.Type: ApplicationFiled: October 27, 2005Publication date: December 20, 2007Inventors: Akira Umada, Koji Azuma, Nobushige Tanaka, Nobuyuki Takizawa, Takehiro Tsutsumi
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Patent number: 7244774Abstract: An aqueous dispersion for inkjet recording containing colorant-containing water-insoluble vinyl polymer particles dispersed in water, wherein the water-insoluble vinyl polymer contains a constitutive unit derived from a styrenic macromer (a) which has a polymerizable functional group at one end, wherein the styrenic macromer (a) has a number-average molecular weight of from 1000 to 5000 and a molecular weight distribution (weight-average molecular weight/number-average molecular weight) of from 1.0 to 2.5; and a water-based ink for inkjet recording containing the aqueous dispersion. The aqueous dispersion is capable of realizing a water-based ink for inkjet recording, which has excellent storage stability, a high optical density, and gives a high gloss.Type: GrantFiled: July 21, 2004Date of Patent: July 17, 2007Assignee: Kao CorporationInventors: Nobushige Tanaka, Koji Azuma, Takehiro Tsutsumi
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Publication number: 20060030641Abstract: Provided are a water dispersion for ink-jet printing, wherein it is a water dispersion of water-insoluble graft polymer particles containing a colorant; the above graft polymer contains a principal chain having a constitutional unit derived from a vinyl base monomer and a side chain which is derived from a macromer containing an aromatic ring and having a polymerizable functional group at one end; both of the Log P values of the above principal chain and the above side chain are positive; and a difference between both falls in a specific range, and a water-based ink containing the same. The above water-based ink is excellent in a discharge stability, a storage stability, a heat stability and a water resistance.Type: ApplicationFiled: July 28, 2005Publication date: February 9, 2006Applicant: KAO CORPORATIONInventors: Nobushige Tanaka, Koji Azuma, Takehiro Tsutsumi
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Patent number: 6881988Abstract: A heterojunction bipolar transistor has a raised breakdown voltage and restrains the rising characteristic of IC-VCE characteristic from degrading. The collector region includes first, second, and third collector layers of semiconductor. The first collector layer is made of a doped or undoped semiconductor in such a way as to contact the sub-collector region. The second collector layer is made of a doped or undoped semiconductor having a narrower band gap than the first collector layer in such a way as to contact the base region. The third collector layer has a higher doping concentration than the second collector layer in such a way as to be located between or sandwiched by the first collector layer and the second collector layer.Type: GrantFiled: August 14, 2002Date of Patent: April 19, 2005Assignee: NEC Compound Semiconductor Devices, Ltd.Inventors: Takaki Niwa, Hidenori Shimawaki, Koji Azuma, Naoto Kurosawa
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Publication number: 20050020731Abstract: An aqueous dispersion for inkjet recording containing colorant-containing water-insoluble vinyl polymer particles dispersed in water, wherein the water-insoluble vinyl polymer contains a constitutive unit derived from a styrenic macromer (a) which has a polymerizable functional group at one end, wherein the styrenic macromer (a) has a number-average molecular weight of from 1000 to 5000 and a molecular weight distribution (weight-average molecular weight/number-average molecular weight) of from 1.0 to 2.5; and a water-based ink for inkjet recording containing the aqueous dispersion. The aqueous dispersion is capable of realizing a water-based ink for inkjet recording, which has excellent storage stability, a high optical density, and gives a high gloss.Type: ApplicationFiled: July 21, 2004Publication date: January 27, 2005Applicant: Kao CorporationInventors: Nobushige Tanaka, Koji Azuma, Takehiro Tsutsumi
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Publication number: 20050009977Abstract: The invention provides a process for producing a water dispersion for ink jet recording,which comprises the following steps 1 and 2: (Step 1) a step of obtaining a pigment treated with (a) a water-insoluble vinyl polymer particles by making a pigment and (a) a water-insoluble vinyl polymer particles present in an aqueous solvent and then removing the solvent; and (Step 2) a step of obtaining a water dispersion of a pigment-containing water-insoluble vinyl polymer particles by dispersing a mixture comprising the water-insoluble vinyl polymer particle (a)-treated pigment obtained in step 1, an organic solvent, (b) a water-insoluble vinyl polymer and water and then removing the organic solvent.Type: ApplicationFiled: June 30, 2004Publication date: January 13, 2005Applicant: Kao CorporationInventors: Koji Azuma, Takehiro Tsutsumi, Ryuma Mizushima, Hirotaka Takeno, Toshiya Iwasaki
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Publication number: 20050004262Abstract: The present invention relates to a water dispersion for ink jet recording, comprising water-insoluble vinyl polymer particles containing a colorant, wherein the water-insoluble vinyl polymer is a water-insoluble vinyl polymer obtained by polymerizing a monomer mixture comprising: (A) a monomer represented by the formula (I): wherein R1 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or a phenyl group whose hydrogen atom may be substituted with an alkyl group having 1 to 9 carbon atoms and m denotes a number from 65 to 100; (B) a salt-forming group-containing monomer; and (C) a hydrophobic monomer and the average particle diameter of the water-insoluble vinyl polymer particles containing a colorant is 0.02 to 0.50 ?m.Type: ApplicationFiled: June 25, 2004Publication date: January 6, 2005Applicant: KAO CORPORATIONInventors: Koji Azuma, Takehiro Tsutsumi, Ryuma Mizushima, Isao Tsuru
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Publication number: 20030144378Abstract: A water-based ink comprising an aqueous dispersion of polymer particles made of a water-insoluble vinyl polymer containing a colorant, wherein the water-insoluble vinyl polymer is prepared by polymerizing a monomer composition comprising a specific monomer A such as a monomer A1 represented by the formula (I): 1Type: ApplicationFiled: December 27, 2002Publication date: July 31, 2003Applicant: Kao CorporationInventors: Ryuma Mizushima, Isao Tsuru, Koji Azuma, Takehiro Tsutsumi
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Publication number: 20030136956Abstract: A heterojunction bipolar transistor has a raised breakdown voltage and restrains the rising characteristic of IC-VCE characteristic from degrading. The collector region includes first, second, and third collector layers of semiconductor. The first collector layer is made of a doped or undoped semiconductor in such a way as to contact the sub-collector region. The second collector layer is made of a doped or undoped semiconductor having a narrower band gap than the first collector layer in such a way as to contact the base region. The third collector layer has a higher doping concentration than the second collector layer in such a way as to be located between or sandwiched by the first collector layer and the second collector layer.Type: ApplicationFiled: August 14, 2002Publication date: July 24, 2003Applicant: NEC Compound Semiconductor Devices, Ltd.Inventors: Takaki Niwa, Hidenori Shimawaki, Koji Azuma, Naoto Kurosawa
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Publication number: 20020195620Abstract: A heterojunction bipolar transistor and a protective PIN diode are implemented by two multi-layered compound semiconductor structures epitaxially grown on respective regions of a semi-insulating substrate; the entire upper surface of the base layer is covered with the emitter layer, and the base electrode on the emitter layer projects through the emitter layer into the base layer; although the two multi-layered compound semiconductor structures are covered with a passivation layer, the emitter layer prevents the base layer from direct contact with the passivation layer so that leakage current hardly flows between the base and the emitter.Type: ApplicationFiled: June 5, 2002Publication date: December 26, 2002Applicant: NEC Compound Semiconductor Devices, Ltd.Inventors: Masahiro Tanomura, Hidenori Shimawaki, Takaki Niwa, Koji Azuma, Naoto Kurosawa
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Patent number: 6031019Abstract: Aqueous ink for ink-jet printing comprises an emulsion of fine polymer particles and contains at least one compound selected from an amino acid or a salt thereof and the like.Type: GrantFiled: February 4, 1998Date of Patent: February 29, 2000Assignee: Kao CorporationInventors: Takehiro Tsutsumi, Koji Azuma, Michitaka Sawada, Tadashi Sakuma, Kenji Kaida, Shigemi Wakabayashi, Tetsuya Ueno, Kuniyasu Kawabe
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Patent number: 5998501Abstract: A process for producing an aqueous ink for inkjet printing capable of giving an elevated print density of printed matters, being improved in fixability to the material to be printed, water resistance and improved storage stability and scarcely scorching onto a printer head. This process comprises dissolving a salt-forming group-having polymer and a hydrophobic dye in a water-insoluble organic solvent to obtain a solution, adding water and a neutralizing agent optionally together with a surfactant to the solution to ionize the salt-forming group of the polymer, emulsifying the resulting mixture, and removing out the solvent from the emulsion to obtain an ink containing an aqueous dispersion of the polymer particles in which the dye has been encompassed.Type: GrantFiled: February 2, 1998Date of Patent: December 7, 1999Assignee: Kao CorporationInventors: Tekehiro Tsutsumi, Koji Azuma, Michitaka Sawada
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Patent number: 4272424Abstract: A novel process is proposed for the preparation of vinyl chloride based resins modified with a polymer latex, according to which the latex polymer is absorbed so completely and uniformly on the polyvinyl chloride resin that the effect of the modification of the resin properties is remarkably enhanced along with no adverse effects on the particle size distribution of the resin product and no effluence of the latex into the waste water discharged in the dehydration of the aqueous polymerizate slurry after completion of the polymerization. The process of the invention comprises introducing the modifier polymer latex into the polymerization mixture only when the monomer conversion is in the range from 30 to 95% and introducing an inorganic fine powder such as fume silica, bentonite and diatomaceous earth into the polymerization mixture at the same time as or before the introduction of the modifier polymer latex.Type: GrantFiled: October 12, 1979Date of Patent: June 9, 1981Assignee: Shin-Etsu Chemical Co., Ltd.Inventors: Hajime Kitamura, Kazuhiko Kurimoto, Koji Azuma