Patents by Inventor Mika Yamamoto

Mika Yamamoto 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: 11697695
    Abstract: A polymerizable composition containing: a) a polymerizable compound having one or two or more polymerizable groups and satisfying formula (I): Re(450 nm)/Re(550 nm)<1.0 (I); b) at least one photopolymerization initiator selected from the group consisting of alkylphenone-based compounds, acylphosphine oxide-based compounds, and oxime ester-based compounds; and c) a polymerization inhibitor. An optically anisotropic body, a retardation film, an antireflective film, and a liquid crystal display device that are produced using the polymerizable liquid crystal composition. The polymerizable composition is excellent in solubility and has high storage stability, so that no precipitation of crystals etc. occurs. When a film-shaped polymer is produced by polymerizing the above composition, the unevenness of the surface of the coating film is small while the alignment of the liquid crystal is maintained, and high durability is obtained. Therefore, the polymerizable composition is useful.
    Type: Grant
    Filed: January 12, 2016
    Date of Patent: July 11, 2023
    Assignee: DIC CORPORATION
    Inventors: Kouichi Endo, Toru Ishii, Yasuhiro Kuwana, Kazuaki Hatsusaka, Mika Yamamoto
  • Publication number: 20230112953
    Abstract: A nematic liquid crystal composition having a high ?n and a high ?? in a liquid crystal material that enables greater phase control over electromagnetic waves in the microwave or millimeter wave range, and a liquid crystal element, a sensor, a liquid crystal lens, an optical communication device, and an antenna including the nematic liquid crystal composition. Specifically, a liquid crystal composition containing one or two or more compounds represented by general formula (i) in the specification and one or two or more compounds represented by general formula (ii) in the specification, and having a high ?n and a high ??.
    Type: Application
    Filed: December 10, 2020
    Publication date: April 13, 2023
    Applicant: DIC Corporation
    Inventors: Mika YAMAMOTO, Yoshio AOKI, Hidetoshi NAKATA, Kazunori MARUYAMA, Shinichi HIRATA, Haruki OHISHI, Masahiro HORIGUCHI
  • Patent number: 11186669
    Abstract: The present invention provides a polymerizable composition containing a specific polymerizable compound and a fluorosurfactant having, in its molecule, a pentaerythritol skeleton or a dipentaerythritol skeleton. The invention also provides an optically anisotropic body, a retardation film, an antireflective film, and a liquid crystal display device that are produced using the polymerizable composition of the present invention. The present invention is useful because, when an optically anisotropic body is produced by photo-polymerization of the polymerizable composition, three features including the leveling properties of the surface of the optically anisotropic body, offset onto the substrate, and liquid crystal alignment can be improved simultaneously.
    Type: Grant
    Filed: January 12, 2016
    Date of Patent: November 30, 2021
    Assignee: DIC CORPORATION
    Inventors: Kouichi Endo, Toru Ishii, Yasuhiro Kuwana, Kazuaki Hatsusaka, Mika Yamamoto
  • Patent number: 10479844
    Abstract: The present invention provides a polymerizable composition containing a specific polymerizable compound and a fluorosurfactant having a specific polyoxyalkylene skeleton and having specific molecular weight. The invention also provides an optically anisotropic body, a retardation film, an antireflective film, and a liquid crystal display device that are produced using the polymerizable composition of the present invention. The present invention is useful because, when an optically anisotropic body is produced by photo-polymerization of the polymerizable composition, three features including the leveling properties of the surface of the optically anisotropic body, offset onto the substrate, and liquid crystal alignment can be improved simultaneously.
    Type: Grant
    Filed: January 16, 2019
    Date of Patent: November 19, 2019
    Assignee: DIC CORPORATION
    Inventors: Kouichi Endo, Toru Ishii, Yasuhiro Kuwana, Kazuaki Hatsusaka, Mika Yamamoto
  • Patent number: 10473820
    Abstract: There is provided a compound containing a mesogenic group, which includes a silicon compound at a low concentration, a polymerizable compound containing the mesogenic group, a mixture and a composition using these compounds, a polymerizable mixture having the polymerizable compound, and a polymer, an optically anisotropic body, and a phase difference film using the polymerizable composition. It is possible to obtain the optically anisotropic body and the phase difference film having satisfactory scratch resistance and adhesion, by using the polymerizable composition composed of the compound containing a mesogenic group, which includes a silicon compound at a low concentration.
    Type: Grant
    Filed: December 18, 2014
    Date of Patent: November 12, 2019
    Assignee: DIC CORPORATION
    Inventors: Mika Yamamoto, Yasuhiro Kuwana, Hidetoshi Nakata, Koichi Endou, Kunihiko Kotani, Hiroshi Hasebe, Yoshiyuki Ono
  • Publication number: 20190233565
    Abstract: The present invention provides a polymerizable composition containing a specific polymerizable compound and a fluorosurfactant having, in its molecule, a pentaerythritol skeleton or a dipentaerythritol skeleton. The invention also provides an optically anisotropic body, a retardation film, an antireflective film, and a liquid crystal display device that are produced using the polymerizable composition of the present invention. The present invention is useful because, when an optically anisotropic body is produced by photo-polymerization of the polymerizable composition, three features including the leveling properties of the surface of the optically anisotropic body, offset onto the substrate, and liquid crystal alignment can be improved simultaneously.
    Type: Application
    Filed: January 12, 2016
    Publication date: August 1, 2019
    Applicant: DIC Corporation
    Inventors: Kouichi Endo, Toru Ishii, Yasuhiro Kuwana, Kazuaki Hatsusaka, Mika Yamamoto
  • Publication number: 20190153125
    Abstract: The present invention provides a polymerizable composition containing a specific polymerizable compound and a fluorosurfactant having a specific polyoxyalkylene skeleton and having specific molecular weight. The invention also provides an optically anisotropic body, a retardation film, an antireflective film, and a liquid crystal display device that are produced using the polymerizable composition of the present invention. The present invention is useful because, when an optically anisotropic body is produced by photo-polymerization of the polymerizable composition, three features including the leveling properties of the surface of the optically anisotropic body, offset onto the substrate, and liquid crystal alignment can be improved simultaneously.
    Type: Application
    Filed: January 16, 2019
    Publication date: May 23, 2019
    Applicant: DIC CORPORATION
    Inventors: Kouichi Endo, Toru Ishii, Yasuhiro Kuwana, Kazuaki Hatsusaka, Mika Yamamoto
  • Patent number: 10253125
    Abstract: There is provided a polymerizable liquid crystal composition that enables a film formed through application of the composition and exposure thereof to heat or active energy rays to have an excellent molecular alignment and reduced haze. There is also provided an optically anisotropic body that is produced by using such a polymerizable liquid crystal composition and that has a good transparency. In particular, the present invention provides a polymerizable liquid crystal composition containing a polymerizable haze-reducing agent and a polymerizable liquid crystal compound. Furthermore, the present invention also provides an optically anisotropic body produced by using the polymerizable liquid crystal composition of the present invention.
    Type: Grant
    Filed: June 16, 2015
    Date of Patent: April 9, 2019
    Assignee: DIC CORPORATION
    Inventors: Kouichi Endo, Mika Yamamoto, Kazuaki Hatsusaka
  • Patent number: 10202470
    Abstract: The present invention provides a polymerizable composition containing a specific polymerizable compound and a fluorosurfactant having a specific polyoxyalkylene skeleton and having specific molecular weight. The invention also provides an optically anisotropic body, a retardation film, an antireflective film, and a liquid crystal display device that are produced using the polymerizable composition of the present invention. The present invention is useful because, when an optically anisotropic body is produced by photo-polymerization of the polymerizable composition, three features including the leveling properties of the surface of the optically anisotropic body, offset onto the substrate, and liquid crystal alignment can be improved simultaneously.
    Type: Grant
    Filed: December 17, 2015
    Date of Patent: February 12, 2019
    Assignee: DIC CORPORATION
    Inventors: Kouichi Endo, Toru Ishii, Yasuhiro Kuwana, Kazuaki Hatsusaka, Mika Yamamoto
  • Patent number: 10196568
    Abstract: The present invention provides a method for producing a polymerizable liquid crystal composition which produces films being uncolored and having no cissing and good alignment when applied to a substrate, and also provides a polymerizable liquid crystal composition produced by the method and an optically anisotropic body using the polymerizable liquid crystal composition. Specifically, the present invention provides a method for producing a polymerizable liquid crystal composition, the method comprising a step (I) of preparing a polymerizable solution by mixing at least one polymerizable compound having at least one polymerizable functional group and one or two or more organic solvents and heating and stirring the resultant mixture; and a step (II) of mixing the polymerizable solution with a polymerization initiator, and also provides a polymerizable liquid crystal composition produced by the method and an optically anisotropic body using the polymerizable liquid crystal composition.
    Type: Grant
    Filed: October 7, 2014
    Date of Patent: February 5, 2019
    Assignee: DIC CORPORATION
    Inventors: Koichi Endou, Yasuhiro Kuwana, Hidetoshi Nakata, Mika Yamamoto, Kunihiko Kotani, Hiroshi Hasebe, Yoshiyuki Ono
  • Publication number: 20180327669
    Abstract: An object of the present invention is to provide a powder mixture containing a polymerizable liquid crystal compound, the powder mixture having a low risk of occurrence of fire due to the flammability of solvent, causing no changes in the appearance due to, for example, precipitation or crystallization of the solute during storage at low temperatures, causing no changes in the composition due to evaporation of solvent during long-term storage or leakage of solvent during long-term storage or transportation, being not viscous and having fluidity unlike nematic liquid crystal compositions, and being easily handled. Another object is to provide a nematic liquid crystal composition, a solution composition, cured products, optical films, and display devices that employ the above-described powder mixture.
    Type: Application
    Filed: July 14, 2016
    Publication date: November 15, 2018
    Applicant: DIC Corporation
    Inventors: Kazuaki Hatsusaka, Yasuhiro Kuwana, Kouichi Endo, Toru Ishii, Mika Yamamoto
  • Patent number: 10106738
    Abstract: An object of the present invention is to provide a polymerizable liquid crystal composition with which two characteristics of smoothness of a surface of an anisotropic optical body and orientation properties of liquid crystals can be simultaneously improved, when preparing an anisotropic optical body to be obtained by photopolymerization of the polymerizable liquid crystal composition. Specifically, an object of the present invention is to provide a polymerizable liquid crystal composition containing specific polymerizable compounds and a fluorine-based surfactant. In addition, an anisotropic optical body, a retardation film, an antireflective film, and a liquid crystal display element prepared using the polymerizable liquid crystal composition of the present invention are also provided.
    Type: Grant
    Filed: October 7, 2014
    Date of Patent: October 23, 2018
    Assignee: DIC CORPORATION
    Inventors: Koichi Endou, Yasuhiro Kuwana, Hidetoshi Nakata, Mika Yamamoto, Kazuaki Hatsusaka
  • Publication number: 20180265609
    Abstract: The present invention provides a polymerizable liquid crystal composition including a specific polymerizable compound and a fluorosurfactant having a pentaerythritol skeleton or a dipentaerythritol skeleton in the molecule. In addition, an optically anisotropic body, a phase difference film, an antireflection film, and a liquid crystal display device, which are produced by using the polymerizable liquid crystal composition according to the present invention, are provided. The present invention is useful because three properties, that is, leveling properties of the surface of an optically anisotropic body, offset to a base material, and alignment properties of a liquid crystal can be improved at the same time in the case where the optically anisotropic body is produced by photopolymerizing the polymerizable liquid crystal composition.
    Type: Application
    Filed: January 7, 2016
    Publication date: September 20, 2018
    Applicant: DIC Corporation
    Inventors: Kouichi Endo, Mika Yamamoto, Kazuaki Hatsusaka
  • Publication number: 20180252957
    Abstract: The present invention provides a polymerizable cholesteric liquid crystal composition containing: one or two or more polymerizable liquid crystal compounds (I) having two or more polymerizable functional groups in the molecule; a chiral compound (III); a polymerization initiator (IV); optionally a non-silicon compound (V) having a repeating unit; and optionally one or two or more polymerizable liquid crystal compounds (II) having one polymerizable functional group. An optically anisotropic body formed from a polymerizable liquid crystal composition according to the present invention is also provided.
    Type: Application
    Filed: August 19, 2016
    Publication date: September 6, 2018
    Applicant: DIC Corporation
    Inventors: Mika Yamamoto, Yasuhiro Kuwana, Yoshiyuki Ono
  • Patent number: 9994772
    Abstract: The present invention provides a liquid crystal display device that is free from a reduction in the voltage holding ratio (VHR) of the liquid crystal layer and an increase in ion density (ID) and that enables problems of defective display, such as white spots, uneven alignment, and image-sticking, to be eliminated. In particular, the present invention provides a liquid crystal display device in which a liquid crystal composition containing a liquid crystal compound having a specific structure is used in the liquid crystal layer and in which an optically anisotropic body formed through polymerization of a polymerizable liquid crystal composition containing a specific amount of a polymerizable liquid crystal compound having a specific structure is used as an in-cell retardation layer.
    Type: Grant
    Filed: July 14, 2015
    Date of Patent: June 12, 2018
    Assignee: DIC Corporation
    Inventors: Takeshi Kuriyama, Jouji Kawamura, Mika Yamamoto, Yasuhiro Kuwana
  • Publication number: 20180016502
    Abstract: The present invention provides a polymerizable composition containing: a) a polymerizable compound having one or two or more polymerizable groups and satisfying formula (I) Re(450 nm)/Re(550 nm)<1.0; and??(I) b) an organic solvent having a solubility parameter (SP value) of 8.50 to 11.00 (cal/cm3)0.5, a boiling point of 75 to 180° C., and an evaporation rate index of 20 to 700. The present invention also provides an optically anisotropic body, a retardation film, an antireflective film, and a liquid crystal display device that are produced using the polymerizable composition of the present invention. The polymerizable composition of the present invention is useful because it is excellent in solubility and has high storage stability that prevents the occurrence of precipitation of crystals. When the composition is polymerized to produce a film-shaped polymer, uneven application is less likely to occur while the liquid crystal alignment is maintained.
    Type: Application
    Filed: January 14, 2016
    Publication date: January 18, 2018
    Applicant: DIC Corporation
    Inventors: Kouichi Endo, Toru Ishii, Yasuhiro Kuwana, Kazuaki Hatsusaka, Mika Yamamoto
  • Publication number: 20180002459
    Abstract: The present invention provides a polymerizable composition containing a specific polymerizable compound and a fluorosurfactant having a specific polyoxyalkylene skeleton and having specific molecular weight. The invention also provides an optically anisotropic body, a retardation film, an antireflective film, and a liquid crystal display device that are produced using the polymerizable composition of the present invention. The present invention is useful because, when an optically anisotropic body is produced by photo-polymerization of the polymerizable composition, three features including the leveling properties of the surface of the optically anisotropic body, offset onto the substrate, and liquid crystal alignment can be improved simultaneously.
    Type: Application
    Filed: December 17, 2015
    Publication date: January 4, 2018
    Applicant: DIC Corporation
    Inventors: Kouichi Endo, Toru Ishii, Yasuhiro Kuwana, Kazuaki Hatsusaka, Mika Yamamoto
  • Publication number: 20180002460
    Abstract: The polymerizable composition contains: a) a polymerizable compound having one or two or more polymerizable groups and satisfying formula (I): Re(450 nm)/Re(550 nm)<1.0??(I); b) at least one photopolymerization initiator selected from the group consisting of alkylphenone-based compounds, acylphosphine oxide-based compounds, and oxime ester-based compounds; and c) a polymerization inhibitor. The present invention also provides an optically anisotropic body, a retardation film, an antireflective film, and a liquid crystal display device that are produced using the polymerizable liquid crystal composition. The polymerizable composition of the present invention is excellent in solubility and has high storage stability, so that no precipitation of crystals etc. occurs. When a film-shaped polymer is produced by polymerizing the above composition, the unevenness of the surface of the coating film is small while the alignment of the liquid crystal is maintained, and high durability is obtained.
    Type: Application
    Filed: January 12, 2016
    Publication date: January 4, 2018
    Applicant: DIC Corporation
    Inventors: Kouichi Endo, Toru Ishii, Yasuhiro Kuwana, Kazuaki Hatsusaka, Mika Yamamoto
  • Publication number: 20170355907
    Abstract: The present invention provides a polymerizable liquid crystal composition including a specific polymerizable compound and a fluorosurfactant having specific polyoxyalkylene skeleton and molecular weight. Also, an optically anisotropic body, a phase difference film, an antireflection film, and a liquid crystal display device, which are produced by using the polymerizable liquid crystal composition according to the present invention, are provided. The present invention is useful because three properties, that is, leveling properties of the surface of an optically anisotropic body, offset to a base material, and alignment properties of a liquid crystal can be improved at the same time in the case where the optically anisotropic body is produced by photopolymerizing the polymerizable liquid crystal composition.
    Type: Application
    Filed: December 10, 2015
    Publication date: December 14, 2017
    Applicant: DIC Corporation
    Inventors: Kouichi Endo, Yasuhiro Kuwana, Hidetoshi Nakata, Mika Yamamoto, Kazuaki Hatsusaka
  • Publication number: 20170292075
    Abstract: The present invention provides a polymerizable liquid crystal composition containing at least one polymerizable liquid crystal compound (I) having one polymerizable functional group in its molecule, at least one polymerizable liquid crystal compound (II) having two polymerizable functional groups in its molecule, and at least one compound (III) having tree or more aromatic rings at least one of which is substituted by an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. Also, the present invention provides an optically anisotropic body using the polymerizable liquid crystal composition of the present invention.
    Type: Application
    Filed: September 8, 2015
    Publication date: October 12, 2017
    Applicant: DIC Corporation
    Inventors: Kouichi Endo, Mika Yamamoto, Kazuaki Hatsusaka