Patents by Inventor Hirofumi Io

Hirofumi Io 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: 9128238
    Abstract: Disclosed is an optical material including a cyclic olefin copolymer containing at least a repeating structural unit [A] represented by the general formula (1) and a repeating structural unit [B] represented by the general formula (2) and having a molar ratio [A]/[B] of from 95/5 to 1/99, wherein the absolute value of the ratio ?OB/?F is from 0.001 to 0.250 in which ?OB represents the amount of a change in the absolute value of the orientation birefringence calculated from the phase difference (nm) at a wavelength of 633 nm/film thickness (?m) in a stretched film obtained from the optical material, and ?F represents the amount of a change in the absolute value of the orientation coefficient determined from the dichroic ratio of parallel light intensity I? to perpendicular light intensity I?, each relative to the orientation direction according to Raman spectroscopy.
    Type: Grant
    Filed: April 4, 2011
    Date of Patent: September 8, 2015
    Assignees: MITSUI CHEMICALS, INC., YASUHIRO KOIKE
    Inventors: Tadahiro Sunaga, Takashi Oda, Hirofumi Io, Keisuke Kawashima, Yasuhiro Koike
  • Publication number: 20130030136
    Abstract: Disclosed is an optical material including a cyclic olefin copolymer containing at least a repeating structural unit [A] represented by the general formula (1) and a repeating structural unit [B] represented by the general formula (2) and having a molar ratio [A]/[B] of from 95/5 to 1/99, wherein the absolute value of the ratio ?OB/?F is from 0.001 to 0.250 in which ?OB represents the amount of a change in the absolute value of the orientation birefringence calculated from the phase difference (nm) at a wavelength of 633 nm/film thickness (?m) in a stretched film obtained from the optical material, and ?F represents the amount of a change in the absolute value of the orientation coefficient determined from the dichroic ratio of parallel light intensity I? to perpendicular light intensity I?, each relative to the orientation direction according to Raman spectroscopy.
    Type: Application
    Filed: April 4, 2011
    Publication date: January 31, 2013
    Applicants: MITSUI CHEMICALS, INC.
    Inventors: Tadahiro Sunaga, Takashi Oda, Hirofumi Io, Keisuke Kawashima, Yasuhiro Koike
  • Patent number: 8216766
    Abstract: A polymer having a rate of dissolution in an alkaline developer that increases under the action of acid is provided. The polymer is prepared by reacting a hydrogenated ROMP polymer with an O-alkylating agent in the presence of a base.
    Type: Grant
    Filed: March 25, 2009
    Date of Patent: July 10, 2012
    Assignees: Shin-Etsu Chemical Co., Ltd., Mitsui Chemicals, Inc.
    Inventors: Takeru Watanabe, Takeshi Kinsho, Tomohiro Kobayashi, Tadahiro Sunaga, Yuichi Okawa, Hirofumi Io
  • Publication number: 20090246686
    Abstract: A polymer having a rate of dissolution in an alkaline developer that increases under the action of acid is provided. The polymer is prepared by reacting a hydrogenated ROMP polymer with an O-alkylating agent in the presence of a base.
    Type: Application
    Filed: March 25, 2009
    Publication date: October 1, 2009
    Inventors: Takeru WATANABE, Takeshi Kinsho, Tomohiro Kobayashi, Tadahiro Sunaga, Yuichi Okawa, Hirofumi Io
  • Patent number: 6875819
    Abstract: The present invention is to provide a fluorine-containing polymer having excellent light transmission in the vacuum ultraviolet region of not more than 193 nm, a monomer favorably used for preparing the fluorine-containing polymer, a process for preparing the fluorine-containing polymer, and uses of the fluorine-containing polymer. The fluorine-containing polymer has at least a repeated unit structure represented by the following formula (1) and has an absorption coefficient of not more than 3.0 ?m?1 at 157 nm of ultraviolet rays. wherein R1 to R12 are each fluorine, a fluorine-containing alkyl group of 1 to 20 carbon atoms, or the like; X1 is —CRaRb—, —NRa— or —PRa— (Ra and Rb are each fluorine, a fluorine-containing alkyl group of 1 to 20 carbon atoms, hydrogen, —O—, —S—, an alkyl group of 1 to 20 carbon atoms, or the like); at least one of R1 to R12 and X1 is fluorine or a fluorine-containing group; and n is 0 or an integer of 1 to 3.
    Type: Grant
    Filed: April 25, 2002
    Date of Patent: April 5, 2005
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Tadahiro Sunaga, Hiroshi Kouno, Kazumori Kawamura, Takashi Ochiai, Shigeto Shigematsu, Takashi Nakano, Tomoyuki Morita, Yoshihiro Yamamoto, Hirofumi Io
  • Patent number: 6800720
    Abstract: A hydrogenated ring-opening metathesis polymer which contains at least a structural unit [B] of the following general formula [3] and/or a structural unit [C] of the following general formula [4]: wherein, R8 to R11 and R13 to R16 each independently represent a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, and X2s and X3s are the same or different and represent —O— or —CR122— wherein, R12 represents a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms). One of Y1 and Y2 represents —(C═O)— and the other of Y1 and Y2 represents —CR182— wherein, R18 represents a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms and m and n represent an integer of 0 or 1 to 3.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: October 5, 2004
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Yoshihiro Yamamoto, Tadahiro Sunaga, Tetsuya Hamada, Keiichi Ikeda, Ritsuko Shibahara, Hirofumi Io, Takashi Ochiai
  • Publication number: 20030187168
    Abstract: The present invention is to provide a fluorine-containing polymer having excellent light transmission in the vacuum ultraviolet region of not more than 193 nm, a monomer favorably used for preparing the fluorine-containing polymer, a process for preparing the fluorine-containing polymer, and uses of the fluorine-containing polymer. The fluorine-containing polymer has at least a repeated unit structure represented by the following formula (1) and has an absorption coefficient of not more than 3.0 &mgr;m−1 at 157 nm of ultraviolet rays.
    Type: Application
    Filed: December 27, 2002
    Publication date: October 2, 2003
    Inventors: Tadahiro Sunaga, Hiroshi Kouno, Kazumori Kawamura, Takashi Ochiai, Shigeto Shigematsu, Takashi Nakano, Tomoyuki Morita, Hirofumi Io, Yoshihiro Yamamoto
  • Publication number: 20020165328
    Abstract: 1.
    Type: Application
    Filed: March 28, 2002
    Publication date: November 7, 2002
    Inventors: Yoshihiro Yamamoto, Tadahiro Sunaga, Tetsuya Hamada, Keiichi Ikeda, Ritsuko Shibahara, Hirofumi Io, Takashi Ochiai
  • Patent number: 5198579
    Abstract: A composite oxide catalyst represented by the general formula: Mo-V-P-X-Y (wherein X represents at least one element selected from the group consisting of Sb, Cu, Co, Bi and As; Y represents at least one element selected from the group consisting of K, Rb, Cs and Tl) and a method for preparing methacrylic acid through gas phase catalytic oxidation of methacrolein with molecular oxygen in the presence of the foregoing catalyst are herein disclosed. The catalyst exhibits excellent catalytic activity, selectivity to methacrylic acid, catalytic stability and lifetime.
    Type: Grant
    Filed: November 12, 1991
    Date of Patent: March 30, 1993
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadatoshi Honda, Nobuhiko Horiuchi, Jun Kitagawa, Masami Murakami, Kazunori Kawahara, Hirofumi Io