Patents by Inventor Keisuke Takuma
Keisuke Takuma 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: 8888906Abstract: A heat-sensitive color-developing composition containing a hydroxyquinoline compound having a methyl group and an acid anhydride compound represented by general formula (1): wherein ring A represents a substituted or unsubstituted aromatic hydrocarbon ring, and n represents an integer of 1 to 3, and a heat-sensitive recording material containing the composition in a recording layer.Type: GrantFiled: September 13, 2011Date of Patent: November 18, 2014Assignee: Yamamoto Chemicals, Inc.Inventors: Ryoji Yamaguchi, Toshihiro Masaoka, Keisuke Takuma
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Publication number: 20130180430Abstract: [Problem to be Solved] To provide a heat-sensitive recording material having high fastness and a vivid hue. [Solution] A heat-sensitive color-developing composition containing a hydroxyquinoline compound having a methyl group and an acid anhydride compound represented by general formula (1): wherein ring A represents a substituted or unsubstituted aromatic hydrocarbon ring, and n represents an integer of 1 to 3, and a heat-sensitive recording material containing the composition in a recording layer.Type: ApplicationFiled: September 13, 2011Publication date: July 18, 2013Applicant: YAMAMOTO CHEMICALS, INC.Inventors: Ryoji Yamaguchi, Toshihiro Masaoka, Keisuke Takuma
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Publication number: 20040039080Abstract: Disclosed is a dental material comprising a sulfur-containing unsaturated carboxylic acid ester compound having a substituent containing a sulfur atom and at least two (meth)acrylic acid residues through an oxygen atom bonded to a secondary or tertiary carbon atom, specifically, a dental material comprising a polymerizable monomer (A) represented by the following formula (1): 1Type: ApplicationFiled: April 22, 2003Publication date: February 26, 2004Inventors: Narimichi Honda, Akifumi Kasagi, Masatoshi Takagi, Atsuo Otsuji, Keisuke Takuma, Takahiro Fujyama
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Patent number: 6570025Abstract: This invention provides sulfur-containing (meth)acrylic ester compounds each of which is represented by the following formula (1); wherein R1 and R2 each independently represent a hydrogen atom or an alkyl group or may be fused together to form a ring, R3 represents a hydrogen atom or a methyl group, X1 represents an oxygen atom or a sulfur atom, m stands for an integer of from 0 to 3, and n stands for an integer of from 1 to 4, polymerizable compositions comprising the sulfur-containing (meth)acrylic acids, and cured products and optical parts obtained by polymerizing the polymerizable compositions. The sulfur-containing (meth)acrylic ester compounds according to the present invention are very useful, as monomers for photocurable, polymerizable compositions, in applications such as optical materials and dental materials.Type: GrantFiled: January 25, 2002Date of Patent: May 27, 2003Assignee: Mitsui Chemicals, Inc.Inventors: Kenichi Fujii, Atsuo Otsuji, Masao Imai, Kenichi Sugimoto, Tadashi Okuma, Rihoko Suzuki, Keisuke Takuma
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Publication number: 20030085387Abstract: Optical materials with improved heat resistance, especially dopant-type GI POFs with improved heat resistance are provided.Type: ApplicationFiled: January 25, 2002Publication date: May 8, 2003Inventors: Takahiro Fujiyama, Hideo Hama, Atsuo Otsuji, Keisuke Takuma
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Patent number: 6482916Abstract: The present invention provides a dyed molded article obtained by dyeing a polycarbonate molded article having repeating structural units represented by the following formula (1-a): Since the polycarbonate molded article is dyed easily, the present invention has made it possible to provide a lens made of a dyed polycarbonate.Type: GrantFiled: May 25, 2001Date of Patent: November 19, 2002Assignee: Mitsui Chemicals, Inc.Inventors: Keisuke Takuma, Atsuo Otsuji, Kenichi Fujii, Kenichi Sugimoto, Masao Imai, Rihiko Suzuki
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Patent number: 6458908Abstract: A sulfur-containing unsaturated carboxylate compound comprising a sulfur-containing substituent and at least two &agr;,&bgr;-unsaturated carboxylic acid residues, which are each attached to a secondary or tertiary carbon atom via an oxygen atom; a polymerizable composition comprising the sulfur-containing unsaturated carboxylate compound; a cured product prepared by polymerizing the polymerizable composition; an optical component consisting of the cured product; and novel intermediate compounds for preparation of the above carboxylate.Type: GrantFiled: May 31, 2000Date of Patent: October 1, 2002Assignee: Mitsui Chemicals, Inc.Inventors: Masao Imai, Kenichi Sugimoto, Kenichi Fujii, Atsuo Otsuji, Tadashi Ohkuma, Masatoshi Takagi, Rihoko Suzuki, Keisuke Takuma
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Patent number: 6355327Abstract: A novel optical recording medium having at least a recording layer and a reflective layer on a substrate is herein disclosed, wherein at least one dipyrromethene metal chelate compound represented by formula (1) is contained in the recording layer: wherein R1 and R9 are each independently an alkenyl group, an aryl group or a heteroaryl group; R2 to R8 are each independently a hydrogen atom, a halogen atom, or a substituted or unsubstituted alkyl, alkoxy, alkenyl, acyl, alkoxycarbonyl, aralkyl, aryl or heteroaryl group having 20 or less carbon atoms; and M is a transition metal.Type: GrantFiled: October 6, 2000Date of Patent: March 12, 2002Assignees: Mitsui Chemicals, Inc., Yamamoto Chemicals, Inc.Inventors: Tsutami Misawa, Taizo Nishimoto, Hisashi Tsukahara, Akira Ogiso, Kenichi Sugimoto, Kenji Mizoue, Keisuke Takuma, Kenichi Kato, Toshihiro Masaoka, Yojiro Kumagae
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Patent number: 6320020Abstract: A sulfur-containing (thio)ether (co)polymer comprising repetitive structural units represented by general formulas 1 and 2, and an optical element using the (co)polymer: where A and B are bivalent organic group; R1 and R2 are hydrogen or alkyl; X1 to X4 are oxygen or sulfur; Y1 and Y2 are halogen, hydroxy, —OR3 or —SR4, in which R3 is sulfur-containing alkyl, aryl, heterocycle or acyl optionally having a substituent other than SH; and R4 is alkyl, aryl, heterocycle or acyl; provided that —OR3 and/or —SR4 constitute 10 to 100% of the total of Y1+Y2. The (co)polymer exhibits good optical, mechanical and thermal properties and a higher refractive index, and may be prepared in a good productivity. The sulfur-containing (thio)ether (co)polymer is useful for manufacturing a variety of optical elements.Type: GrantFiled: September 3, 1999Date of Patent: November 20, 2001Assignee: Mitsui Chemicals, Inc.Inventors: Keisuke Takuma, Kenichi Sugimoto, Atsuo Otsuji, Rihoko Suzuki, Kenichi Fujii, Masao Imai
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Patent number: 6310147Abstract: An epoxy-resin composition comprising (A) an at least bifunctional epoxy compound and/or an at least bifunctional epoxy resin, (B) an at least bifunctional ester-containing compound and/or an at least bifunctional ester-containing resin as a curing agent, 10 to 100% of whose hydroxy groups are esterified with aliphatic or aromatic acyl groups, and (C) an accelerating agent, the accelerating agent essentially containing a phosphine oxide represented by general formula (1): where R1 to R6 all of which may be the same or not are hydrogen, straight, branched or cyclic alkyl having 1 to 10 carbons or aryl or aralkyl having 6 to 10 carbons.Type: GrantFiled: May 17, 1999Date of Patent: October 30, 2001Assignee: Mitsui Chemicals, Inc.Inventors: Tatsuhiro Urakami, Kenichi Sugimoto, Takuo Tajima, Koutaro Suzuki, Keisuke Takuma, Tadahito Nobori, Usaji Takaki
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Patent number: 6297332Abstract: An epoxy-resin composition comprising (A) an at least bifunctional epoxy compound and/or an at least bifunctional epoxy resin, (B) a curing agent, and (C) an accelerating agent, the accelerating agent essentially containing a phosphine oxide represented by general formula (1); where R1 to R6 all of which may be the same or not are hydrogen, straight, branched or cyclic alkyl having 1 to 10 carbons or aryl or aralkyl having 6 to 10 carbons.Type: GrantFiled: April 22, 1999Date of Patent: October 2, 2001Assignee: Mitsui Chemicals, Inc.Inventors: Tatsuhiro Urakami, Kenichi Sugimoto, Keisuke Takuma, Tadahito Nobori, Usaji Takaki
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Patent number: 6162520Abstract: A novel optical recording medium having at least a recording layer and a reflective layer on a substrate is herein disclosed, wherein at least one dipyrromethene metal chelate compound represented by formula (1) is contained in the recording layer: ##STR1## wherein R.sub.1 and R.sub.9 are each independently an alkenyl group, an aryl group or a heteroaryl group; R.sub.2 to R.sub.8 are each independently a hydrogen atom, a halogen atom, or a substituted or unsubstituted alkyl, alkoxy, alkenyl, acyl, alkoxycarbonyl, aralkyl, aryl or heteroaryl group having 20 or less carbon atoms; and M is a transition metal.Type: GrantFiled: September 8, 1998Date of Patent: December 19, 2000Assignees: Mitsui Chemicals, Inc., Yamamoto Chemicals, Inc.Inventors: Tsutami Misawa, Taizo Nishimoto, Hisashi Tsukahara, Akira Ogiso, Kenichi Sugimoto, Kenji Mizoue, Keisuke Takuma, Kenichi Kato, Toshihiro Masaoka, Yojiro Kumagae
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Patent number: 6130346Abstract: A process for preparing an organic compound, comprising conducting an organic reaction in the presence of a phosphine oxide represented by formula (1); ##STR1## where R.sup.1 is the same or different and each represents a hydrogen or hydrocarbon group with 1 to 10 carbon atoms, and x is the amount of water as a molar ratio which is 0 to 5.0, exhibiting a high catalytic performance especially in an organic reaction involving an alkylene oxide.Type: GrantFiled: April 13, 1999Date of Patent: October 10, 2000Assignee: Mitsui Chemicals, Inc.Inventors: Tadahito Nobori, Takaomi Hayashi, Isao Hara, Shinji Kiyono, Atsushi Shibahara, Katsuhiko Funaki, Tatsuhiro Urakami, Keisuke Takuma, Usaji Takaki
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Patent number: 6106999Abstract: A visible light curable resin composition containing a photocurable resin, a photoreaction initiator and a photosensitizer having the formula (1). The composition has a very high sensitivity to a general-purpose visible light laser, so that a high-speed scanning exposure is possible by the laser, and an extremely fine high resolution can be obtained. In addition, the composition can be used for coating or printing under safelight irradiating conditions and under bright circumstantial conditions without any thickening of the composition, and hence the composition can exert excellent noticeable effects in points of safe operativity, operational efficiency and the stability of products. Formula (1) is as follows: ##STR1## wherein rings X.sub.1 and X.sub.2 are each an optionally substituted pyrrole ring; Y is H, CN, optionally substituted alkyl, aralkyl, aryl, heteroaryl or alkenyl group; and Z.sub.1 and Z.sub.Type: GrantFiled: August 10, 1998Date of Patent: August 22, 2000Assignees: Mitsui Chemicals, Kansai Paint Co., Ltd.Inventors: Akira Ogiso, Tsutami Misawa, Taizo Nishimoto, Hisashi Tsukahara, Keisuke Takuma, Kenichi Sugimoto, Takeshi Tsuda, Genji Imai, Hideo Kogure
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Patent number: 6080833Abstract: A low-birefringent organic optical component comprising a polymer prepared by polymerizing a racemic mixture of the monomer with an asymmetric spiro ring represented by general formula (1) as an essential ingredient; wherein ring A represents a monocyclic or polycyclic organic group, wherein two ring As are mutually bound each other via a spiro bond to form a spiro ring which has a molecular asymmetric structure; n is an integer of 0 to 10; X.sub.1 and Y.sub.1 are binding groups; and Z.sub.1 is a polymerization-active group. The component has excellent transparency, mechanical strength and heat resistance, as well as a low birefringence.Type: GrantFiled: July 17, 1997Date of Patent: June 27, 2000Assignee: Mitsui Chemicals, Inc.Inventors: Atsuo Otsuji, Keisuke Takuma, Rihoko Suzuki, Tatsuhiro Urakami, Toshihiro Motoshima, Wataru Yamashita, Tomomi Yoshimura, Atsushi Shibuya, Yoshihiro Sakata, Hideaki Oikawa, Masahiro Ohta, Masanobu Ajioka, Masatoshi Takagi, Akio Karasawa
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Patent number: 6060606Abstract: An optical recording medium having at least a recording layer and a reflective layer on a substrates, the said recording layer contains a dipyrromethene metal chelate compound obtained from a dipyrromethene compound represented by the general formula (1) and a metal ion: ##STR1## wherein R.sup.1 to R.sup.7 are defined in the specification.Type: GrantFiled: April 14, 1999Date of Patent: May 9, 2000Assignees: Mitsui Chemicals, Inc., Yamamoto Chemicals, Inc.Inventors: Tsutami Misawa, Kenichi Sugimoto, Taizo Nishimoto, Hisashi Tsukahara, Takeshi Tsuda, Keisuke Takuma, Hideki Umehara
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Patent number: 6028161Abstract: A polycarbonate copolymer comprising the repeating structural unit represented by general formula (1-a) and at least one of the repeating structural units represented by general formulas (2-a) and (3-a) is provided.Type: GrantFiled: December 17, 1998Date of Patent: February 22, 2000Assignee: Mitsui Chemicals, Inc.Inventors: Atsuo Otsuji, Rihoko Suzuki, Kenichi Sugimoto, Tatsuhiro Urakami, Keisuke Takuma
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Patent number: 5990261Abstract: A low birefringent organic optical component prepared from a resin consisting essentially of one or more repetitive structural units selected from the group consisting of structures represented by general formula (1); ##STR1## wherein A is either of the groups below. ##STR2## The organic optical component can exhibit excellent transparency, heat resistance and mechanical strength as well as a low birefringence. Also provided is a novel aromatic polyamide with a low permitivity and excellent transparency, processability and thermal stability, besides excellent heat resistance inherent in an aromatic polyamide.Type: GrantFiled: August 26, 1997Date of Patent: November 23, 1999Assignee: Mitsui Chemicals, Inc.Inventors: Wataru Yamashita, Tomomi Yoshimura, Atsushi Shibuya, Yoshihiro Sakata, Hideaki Oikawa, Keisuke Takuma, Masahiro Ohta
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Patent number: 5953857Abstract: A method for controlling plant growth by exposing plants to light passing through a covering material comprising a base material containing a colorant. The type and content of the colorant are chosen to provide a photosynthetically effective photon flux (PPF) transmittance of 50% or greater when light is passed through the covering material, and an A value suitable for the purpose of promoting or retarding the growth of plants irradiated with light transmitted by the covering material, the A value being defined by the following equation:A=R/Frwhere R is the photon flux of red light in the wavelength range of 600 to 700 nm and Fr is the photon flux of far red light in the wavelength range of 700 to 800 nm.Type: GrantFiled: July 3, 1997Date of Patent: September 21, 1999Assignee: Mitsui Chemicals, Inc.Inventors: Ichiro Aiga, Katsusuke Murakami, Shuhei Ikado, Ryu Nakamura, Ryu Oi, Kazuhiro Seino, Keisuke Takuma
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Patent number: 5948593Abstract: An optical recording medium having at least a recording layer and a reflective layer on a substrate. The recording layer contains a dipyrromethene metal chelate compound obtained from a dipyrromethene compound represented by the general formula (1) and a metal ion: ##STR1## wherein R.sup.1 to R.sup.7 are defined in the specification.Type: GrantFiled: July 22, 1997Date of Patent: September 7, 1999Assignees: Mitsui Chemicals, Inc., Yamamoto Chemicals, Inc.Inventors: Tsutami Misawa, Kenichi Sugimoto, Taizo Nishimoto, Hisashi Tsukahara, Takeshi Tsuda, Keisuke Takuma, Hideki Umehara