Patents by Inventor Hirofumi TOKUNAGA

Hirofumi TOKUNAGA 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).

  • Publication number: 20150299028
    Abstract: The present invention relates to a non-alkali glass substrate, having a strain point of 685° C. or higher and 750° C. or lower, an average thermal expansion coefficient at 50 to 350° C. of from 35×10?7 to 43×10?7/° C., a specific gravity of from 2.50 to 2.80, a photoelastic constant of 25 nm/MPa/cm or more and less than 29 nm/MPa/cm, and a temperature (T4) at which viscosity reaches 104 dPa·s of 1,250° C. or higher and lower than 1,350° C., and having a prescribed composition.
    Type: Application
    Filed: December 2, 2013
    Publication date: October 22, 2015
    Applicant: ASAHI GLASS COMPANY, LIMITED
    Inventors: Manabu NISHIZAWA, Akio KOIKE, Hirofumi TOKUNAGA
  • Publication number: 20150093561
    Abstract: The present invention relates to an alkali-free glass having a strain point of from 680 to 735° C., an average thermal expansion coefficient at from 50 to 350° C. of from 30×10?7 to 43×10?7/° C., and a specific gravity of 2.60 or less, and containing, indicated by mol % on the basis of oxides, SiO2 65 to 69%, Al2O3 11.5 to 14%, B2O3 3 to 6.5%, MgO 1 to 5%, CaO 7.5 to 12%, SrO 0 to 1%, BaO 0.5 to 6%, and ZrO2 0 to 2%.
    Type: Application
    Filed: December 8, 2014
    Publication date: April 2, 2015
    Applicant: ASAHI GLASS COMPANY, LIMITED
    Inventors: Hirofumi Tokunaga, Manabu Nishizawa, Akio Koike
  • Publication number: 20150087495
    Abstract: The present invention relates to an alkali-free glass having a strain point of 680 to 735° C., an average thermal expansion coefficient at from 50 to 350° C. of from 30×10?7 to 43×10?7/° C., a temperature T2 at which glass viscosity reaches 102 dPa.s of 1,710° C. or lower, and a temperature T4 at which the glass viscosity reaches 104 dPa.s of 1,310° C. or lower, and containing, indicated by mol % on the basis of oxides, SiO2 63 to 74, Al2O3 11.5 to 16, B2O3 exceeding 1.5 to 5, MgO 5.5 to 13, CaO 1.5 to 12, SrO 1.5 to 9, BaO 0 to 1, and ZrO2 0 to 2, in which MgO+CaO+SrO+BaO is from 15.5 to 21, MgO/(MgO+CaO+SrO+BaO) is 0.35 or more, CaO/(MgO+CaO+SrO+BaO) is 0.50 or less, and SrO/(MgO+CaO+SrO+BaO) is 0.50 or less.
    Type: Application
    Filed: December 5, 2014
    Publication date: March 26, 2015
    Applicant: ASAHI GLASS COMPANY, LIMITED
    Inventors: Manabu NISHIZAWA, Hirofumi Tokunaga, Akio Koike
  • Publication number: 20150087494
    Abstract: The present invention relates to an alkali-free glass having a strain point of 710° C. or higher, an average thermal expansion coefficient at from 50 to 350° C. of from 30×10?7 to 43×10?7/° C., a temperature T2 at which glass viscosity reaches 102 dPa·s of 1,710° C. or lower, and a temperature T4 at which the glass viscosity reaches 104 dPa·s of 1,320° C. or lower, containing, indicated by % by mass on the basis of oxides: SiO2 58.5 to 67.5, Al2O3 18 to 24, B2O3 0 to 1.7, MgO 6.0 to 8.5, CaO 3.0 to 8.5, SrO 0.5 to 7.5, BaO 0 to 2.5, and ZrO2 0 to 4.0, containing 0 to 0.35% by mass of Cl, 0.01 to 0.15% by mass of F, and 0.01 to 0.3% by mass of SnO2, and having a ?-OH value of the glass of from 0.15 to 0.60 mm?1.
    Type: Application
    Filed: December 4, 2014
    Publication date: March 26, 2015
    Applicant: ASAHI GLASS COMPANY, LIMITED
    Inventors: Hirofumi TOKUNAGA, Akio Koike, Manabu Nishizawa, Tomoyuki Tsujimura
  • Publication number: 20150072130
    Abstract: The present invention relates to an alkali-free glass substrate with a thickness of 0.4 mm or less, which has been reduced in thickness by 5 ?m or more by a hydrofluoric acid (HF) etching treatment, in which the alkali-free glass substrate contains an alkali-free glass described below, and the alkali-free glass substrate after reduced in thickness has a specific modulus of 32 MNm/kg or more and a photoelastic constant of 31 nm/MPa/cm or less, the alkali-free glass having a strain point of 710° C. or higher, an average thermal expansion coefficient at 50 to 350° C. of from 30×10?7to 43×10?7/° C., a temperature T2 at which a glass viscosity reaches 102 dPa·s of 1710° C. or lower, a temperature T4 at which the glass viscosity reaches 104 dPa·s of 1320° C. or lower.
    Type: Application
    Filed: November 14, 2014
    Publication date: March 12, 2015
    Applicant: ASAHI GLASS COMPANY, LIMITED
    Inventors: Hirofumi TOKUNAGA, Tomoyuki TSUJIMURA, Manabu NISHIZAWA, Akio KOIKE
  • Publication number: 20150045201
    Abstract: The present invention relates to a non-alkali glass having a strain point of 710° C. or higher, an average thermal expansion coefficient at from 50 to 300° C. of from 30×10?7 to 43×10?7/° C., a temperature T2 at which glass viscosity reaches 102 dPa·s of 1,710° C. or lower, a temperature T4 at which the glass viscosity reaches 104 dPa·s of 1,320° C. or lower, containing, indicated by percentage by mass on the basis of oxides, SiO2 58.5 to 67.5, Al2O3 18 to 24, B2O3 0 to 1.7, MgO 6.0 to 8.5, CaO 3.0 to 8.5, SrO 0.5 to 7.5, BaO 0 to 2.5 and ZrO2 0 to 4.0, containing Cl in an amount of from 0.15 to 0.35% by mass, F in an amount of from 0.01 to 0.15% by mass and SO3 in an amount of from 1 to 25 ppm and having a ?-OH value of the glass of from 0.15 to 0.45 mm?1, in which (MgO/40.3)+(CaO/56.1)+(SrO/103.6)+(BaO/153.3) is from 0.27 to 0.35, (MgO/40.3)/((MgO/40.3)+(CaO/56.1)+(SrO/103.6)+(BaO/153.3)) is 0.40 or more, (MgO/40.3)/((MgO/40.3)+(CaO/56.1)) is 0.40 or more, and (MgO/40.3)/((MgO/40.3)+(SrO/103.6)) is 0.
    Type: Application
    Filed: October 27, 2014
    Publication date: February 12, 2015
    Applicant: ASAHI GLASS COMPANY, LIMITED
    Inventors: Hirofumi TOKUNAGA, Shingo Urata, Akio Koike, Manabu Nishizawa, Takashi Enomoto, Tomoyuki Tsujimura
  • Publication number: 20150045203
    Abstract: The present invention relates to a non-alkali glass having a strain point of from 710° C. to lower than 725° C., an average thermal expansion coefficient at from 50 to 300° C. of from 30×107 to 43×10?7/° C., a temperature T2 at which glass viscosity reaches 102dPa.s of 1710° C. or lower, a temperature T4 at which the glass viscosity reaches 104 dPd.s of 1320° C. or lower, and containing, indicated by mol % on the basis of oxides, SiO2 66 to 70, Al2O3 12 to 14, B2O3 exceeding 0 to 1.5, MgO exceeding 9.5 to 13 (or 5 to 9.5), CaO 4 to 9 (or 4 to 11), SrO 0.5 to 4.5, BaO 0 to 0.5 and ZrO 0 to 2.
    Type: Application
    Filed: October 27, 2014
    Publication date: February 12, 2015
    Applicant: ASAHI GLASS COMPANY, LIMITED
    Inventors: Hirofumi TOKUNAGA, Tomoyuki TSUJIMURA, Manabu NISHIZAWA, Akio KOIKE
  • Publication number: 20140366581
    Abstract: The present invention relates to a production method for a non-alkali glass, containing putting glass raw materials in a melting furnace, heating to a temperature of 1,350 to 1,750° C. to prepare a molten glass, and forming the molten glass into a sheet shape by float method, in which the heating in the melting furnace concurrently utilizes heating by combustion flame of burners and electrical heating of the molten glass by heating electrodes arranged so as to be dipped in the molten glass in the melting furnace, and in which when electrical resistivity at 1,350° C. of the molten glass is represented by Rg (?cm) and electrical resistivity at 1,350° C. of a refractory constituting the melting furnace is represented by Rb (?cm), the glass raw materials and the refractory are selected so as to achieve Rb>Rg.
    Type: Application
    Filed: August 27, 2014
    Publication date: December 18, 2014
    Applicant: ASAHI GLASS COMPANY, LIMITED
    Inventors: Hirofumi TOKUNAGA, Akio Koike, Manabu Nishizawa, Tomoyuki Tsujimura
  • Publication number: 20140287905
    Abstract: A method for manufacturing an alkali-free glass includes heating the glass raw material at a temperature of 1,400 to 1,800° C. in a melting furnace to thereby prepare a molten glass, and forming the molten glass into a sheet shape, wherein heating by combustion flame of a burner and electrical heating of the molten glass by a heating electrode arranged so as to be dipped in the molten glass in the melting furnace are used in combination in the heating in the melting furnace, and when an electrical resistivity of the molten glass at 1,400° C. is Rg (?cm) and an electrical resistivity of a refractory constituting the melting furnace at 1,400° C. is Rb (?cm), the glass raw material and the refractory are selected so as to satisfy Rb>Rg.
    Type: Application
    Filed: June 6, 2014
    Publication date: September 25, 2014
    Applicant: ASAHI GLASS COMPANY, LIMITED
    Inventors: Hirofumi TOKUNAGA, Akio Koike, Manabu Nishizawa, Tomoyuki Tsujimura