Search

US-20260125308-A1 - ALKALI-FREE GLASS

US20260125308A1US 20260125308 A1US20260125308 A1US 20260125308A1US-20260125308-A1

Abstract

An alkali-free glass includes, in mol % in terms of oxides: SiO 2 : 63-75%; Al 2 O 3 :10-16%; B 2 O 3 : 0-5%; MgO: 0.1-15%; CaO: 0.1-12%; SrO: 0-8%; and BaO: 0-6%. [MgO]/[CaO] is 1.5 or smaller. A value of Formula (A) is 82.5 or larger. A value of Formula (B) is 690 or larger and 800 or smaller. A value of Formula (C) is 100 or smaller. A value of Formula (D) is 20 or smaller. The alkali-free glass has a Young's modulus of 83 GPa or larger and a surface devitrification viscosity η c of 10 4.2 dPa·s or higher.

Inventors

  • Hirofumi TOKUNAGA
  • Kazutaka Ono

Assignees

  • AGC Inc.

Dates

Publication Date
20260507
Application Date
20251230
Priority Date
20190207

Claims (20)

  1. 1 . An alkali-free glass, comprising, in mol % in terms of oxides: SiO 2 :63 to 75%; Al 2 O 3 :10 to 16%; B 2 O 3 : 0.1 to 5%; MgO: 0.1 to 15%; CaO: 0.1 to 12%; SrO: 0 to 3%; and BaO: 0 to 6%, wherein: [MgO]/[CaO] is 1.5 or smaller; a value of Formula (A) is 82.5 or larger, Formula (A) being 1.131[SiO 2 ]+1.933[Al 2 O 3 ]+0.362[B 2 O 3 ]+2.049[MgO]+1.751[CaO]+1.471[SrO]+1.039[BaO]−48.25; a value of Formula (B) is in a range of 690 to 800, Formula (B) being 35.59[SiO 2 ]+37.34[Al 2 O 3 ]+24.59[B 2 O 3 ]+31.13[MgO]+31.26[CaO]+30.78[SrO]+31.98[BaO]−2761; a value of Formula (C) is 100 or smaller, Formula (C) being −9.01[SiO 2 ]+36.36[Al 2 O 3 ]+5.7[B 2 O 3 ]+5.13[MgO]+17.25[CaO]+7.65[SrO]+10.58[BaO]; a value of Formula (D) is 14 or smaller, Formula (D) being −0.731[SiO 2 ]+1.461[Al 2 O 3 ]−0.157[B 2 O 3 ]+1.904[MgO]+3.36[CaO]+3.411[SrO]+1.723[BaO]+(−3.318[MgO][CaO]−1.675[MgO][SrO]+1.757[MgO][BaO]+4.72[CaO][SrO]+2.094[CaO][BaO]+1.086[SrO][BaO])/([MgO]+[CaO]+[SrO]+[BaO]); and the alkali-free glass has a Young's modulus of 83 GPa or larger and a surface devitrification viscosity η c of 10 4.2 dPa·s or higher.
  2. 2 . The alkali-free glass according to claim 1 , wherein a value of Formula (E) is in a range of 1.50 to 5.50, Formula (E) being 4.379[SiO 2 ]+5.043[Al 2 O 3 ]+4.805[B 2 O 3 ]+4.828[MgO]+4.968[CaO]+5.051[SrO]+5.159[BaO]−453.
  3. 3 . The alkali-free glass according to claim 1 , wherein the alkali-free glass has a strain point of 690° C. or higher.
  4. 4 . The alkali-free glass according to claim 1 , wherein the alkali-free glass has a density of 2.8 g/cm 3 or lower and an average thermal expansion coefficient in 50 to 350° C. of 30×10 −7 /° C. to 45×10 −7 /° C.
  5. 5 . The alkali-free glass according to claim 1 , wherein the alkali-free glass has a temperature T 2 at which a glass viscosity becomes 10 2 dPa·s of 1800° C. or lower and a temperature T 4 at which the glass viscosity becomes 10 4 dPa·s of 1400° C. or lower.
  6. 6 . The alkali-free glass according to claim 1 , wherein the alkali-free glass has an internal devitrification temperature of 1320° C. or lower.
  7. 7 . The alkali-free glass according to claim 1 , wherein the alkali-free glass has an internal devitrification viscosity η d of 10 4.4 dPa·s or higher.
  8. 8 . The alkali-free glass according to claim 1 , wherein the alkali-free glass has a crystal growth rate of 100 μm/hr or lower.
  9. 9 . The alkali-free glass according to claim 1 , further comprising: at least one selected from the group consisting of Li 2 O, Na 2 O, and K 2 O in an amount of greater than 0% to 0.2% in total in mole % in terms of oxides.
  10. 10 . An alkali-free glass, comprising, in mol % in terms of oxides: SiO 2 : 50 to 80%; Al 2 O 3 :8 to 20%; B 2 O 3 : 0.1 to 5%; MgO: 0.1 to 15%; CaO: 0.1 to 12%; SrO: 0 to 3%; BaO: 0 to 6%, Li 2 O+Na 2 O+K 2 O: 0 to 0.2%; and P 2 O 5 : 0 to 1%, wherein [MgO]/[CaO] is 1.5 or smaller, a value of Formula (A) is 82.5 or larger, Formula (A) being 1.131 [SiO 2 ]+1.933[Al 2 O 3 ]+0.362[B 2 O 3 ]+2.049[MgO]+1.751[CaO]+1.471[SrO]+1.039[BaO]−48.25, a value of Formula (D) is 14 or smaller, Formula (D) being −0.731[SiO 2 ]+1.461[Al 2 O 3 ]−0.157[B 2 O 3 ]+1.904[MgO]+3.36[CaO]+3.411[SrO]+1.723[BaO]+(−3.318[MgO][CaO]−1.675[MgO][SrO]+1.757[MgO][BaO]+4.72[CaO][SrO]+2.094[CaO][BaO]+1.086[SrO][BaO])/([MgO]+[CaO]+[SrO]+[BaO]), and the alkali-free glass has: a Young's modulus of 83 GPa or larger; a strain point of 690° C. or higher; a temperature T 4 at which a glass viscosity becomes 10 4 dPa·s of 1400° C. or lower; a temperature T 2 at which the glass viscosity becomes 10 2 dPa·s of 1800° C. or lower; an internal devitrification temperature of 1320° C. or lower; an internal devitrification viscosity η d of 10 4 dPa·s or higher; a surface devitrification viscosity η c of 10 4.2 dPa·s or higher; a crystal growth rate of 100 μm/hr or lower; a density of 2.8 g/cm 3 or lower; and an average thermal expansion coefficient in 50-350° C. of 30×10 −7 to 45×10 −7 /° C.
  11. 11 . The alkali-free glass according to claim 10 , wherein a value of Formula (B) is in a range of 690 to 800, Formula (B) being 35.59[SiO 2 ]+37.34[Al 2 O 3 ]+24.59[B 2 O 3 ]+31.13[MgO]+31.26[CaO]+30.78[SrO]+31.98[BaO]−2761.
  12. 12 . The alkali-free glass according to claim 10 , wherein a value of Formula (C) is 100 or smaller, Formula (C) being −9.01[SiO 2 ]+36.36[Al 2 O 3 ]+5.7[B 2 O 3 ]+5.13[MgO]+17.25[CaO]+7.65[SrO]+10.58[BaO].
  13. 13 . The alkali-free glass according to claim 10 , wherein a value of Formula (E) is in a range of 1.50 to 5.50, Formula (E) being 4.379[SiO 2 ]+5.043[Al 2 O 3 ]+4.805[B 2 O 3 ]+4.828[MgO]+4.968[CaO]+5.051[SrO]+5.159[BaO]−453.
  14. 14 . The alkali-free glass according to claim 1 , further comprising: F in an amount of greater than 0 mol % to 1.5 mol %.
  15. 15 . The alkali-free glass according to claim 1 , further comprising: SnO 2 in an amount of greater than 0% to 0.5% in mol % in terms of oxides.
  16. 16 . The alkali-free glass according to claim 1 , wherein the alkali-free glass has a glass β-OH value in a range of 0.01 mm −1 to 0.5 mm −1 .
  17. 17 . The alkali-free glass according to claim 1 , wherein the alkali-free glass has an annealing point of 850° C. or lower.
  18. 18 . The alkali-free glass according to claim 1 , wherein the alkali-free glass has a compaction of 150 ppm or smaller when being held at 600° C. for 80 min.
  19. 19 . The alkali-free glass according to claim 1 , wherein the alkali-free glass has an equivalent cooling rate in a range of 5° C./min to 800° C./min.
  20. 20 . The alkali-free glass according to claim 1 , wherein the alkali-free glass has a sludge volume when the glass is subjected to an etching process of 30 ml or smaller.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation of U.S. application Ser. No. 17/396,277, filed Aug. 6, 2021, which is a continuation Application of PCT/JP2020/004848, filed on Feb. 7, 2020, which is based on and claims the benefits of priority to Japanese Applications No. 2019-020257, filed Feb. 7, 2019, No. 2019-051570, filed on Mar. 19, 2019, No. 2019-141422, filed Jul. 31, 2019, No. 2019-186805, filed Oct. 10, 2019, and No. 2020-017691, filed Feb. 5, 2020. The entire contents of each of the above applications are incorporated herein by reference. TECHNICAL FIELD The present invention relates to alkali-free glass that is suitable for substrate glass etc. for various displays, photomasks, support for electronic devices, information recording media, planar antennas, dimming laminates, vehicular window glasses, and acoustic vibration plates, etc. BACKGROUND ART Conventionally, glass that is used for glass plates (glass substrates) for various displays, photomasks, support for electronic device and information recording media, in particular glass used for glass plates on the surfaces of which a thin-film of a metal, an oxide, or the like is to be formed, is required to have the following properties (1) to (4). (1) The glass contains substantially no alkali metal ions. This is because if glass contains alkali metal oxides, alkali metal ions diffuse through the above-described thin film and degrade the film characteristics of the thin film.(2) The strain point is high so that shrinkage (compaction) that accompanies deformation of a glass plate and stabilization of the glass structure occurring when the glass plate is exposed to a high temperature in a thin-film forming process can be minimized.(3) The chemical durability against various chemicals used for formation of a semiconductor is sufficiently high. In particular, the glass is durable against buffered hydrofluoric acid (BHF: a mixed liquid of hydrofluoric acid and ammonium fluoride) for etching of SiOx and SiNx, liquid chemicals containing hydrochloric acid and used for ITO etching, various kinds of acids (nitric acid, sulfuric acid, etc.) used for etching a metal electrode, alkalis of resist peeling liquids, etc.(4) No defects (bubbles, striae, inclusions, pits, scratches, etc.) exist inside or in the surface. In addition to the above requirements, the following requirements (5) to (9) have been imposed further in recent years: (5) Glass itself that is small in specific gravity is desired because displays etc. are required to be reduced in weight.(6) Thickness reduction of glass plates are desired because displays etc. are required to be reduced in weight.(7) High heat resistance is desired because polysilicon (p-Si; high in heat treatment temperature) type liquid crystal displays have come to be manufactured in addition to conventional amorphous silicon (a-Si) type liquid crystal displays. The heat resistance of a-Si is about 350° C. and that of p-Si is 350-550° C.(8) To increase the productivity by increasing the temperature rising and dropping rates in fabrication of a display or the like or to increase the thermal shock resistance, glass that is small in average thermal expansion coefficient is required. On the other hand, in the case where the average thermal expansion coefficient of glass is too small, if the number of processes for forming various films such as a gate metal film and a gate insulating film in manufacturing a display or the like is large, the glass is increased in warp, leading to problems, for example, causing troubles such as occurrence of breaking or a scratch during transport of the display or the like and large deviation of exposure patterns.(9) Furthermore, in recent years, with size increase and thinning of glass substrates, glass having a large specific modulus ((Young's modulus)/density) has been required. To satisfy requirements as described above, various glass compositions have been proposed so far for, for example, glass for a display panel (refer to Patent Literatures 1-4). In recent years, the resolution of electronic displays is further increasing. With the increase in resolution, large-size TVs have a problem that the substrate is increased in warp by formation of various kinds of films (e.g., due to film thickness increase of Cu interconnections). This has increased the need for a substrate that is small in warp and, to fulfill this need, it is necessary to increase the Young's modulus of glass. However, glass having a large Young's modulus as disclosed in Patent Literature 3 or 4 is high in strain point and its devitrification temperature tends to be higher than a temperature T4 at which the glass viscosity becomes 104 dPa·s. This makes it difficult to form glass and it is worried that a resulting increased load on manufacturing facilities may increase the manufacturing cost. CITATION LIST Patent Literature Patent Literature 1: Japanese Patent No. 5702888Patent Literature 2: WO 20