Agc Inc.

Asahi Glass Company, Limited

Hirofumi Tokunaga

Kazutaka Ono

Akio Koike

Manabu Nishizawa

Motoyuki Hirose

Jun Akiyama

Masaya Kunigita

Tomoyuki Tsujimura

Daisuke Kobayashi

Yasumasa Kato

Atsuyoshi Takenaka

Shunji Inoue

Tetsushi Takiguchi

Taketoshi Taniguchi

Yoshitaka Maeyanagi

An alkali-free glass includes, in mol % in terms of oxides: SiO: 63-69%; AlO: 8-13%; BO: 0.5-4%; MgO: 8-15%; CaO: 4-12%; SrO: 0-4.5%; and BaO: 0-1%. [MgO]/[CaO] is 0.67 to 3.75. A value of Formula (A) is 84 or larger. A value of Formula (B) is 715 or smaller. A value of Formula (C) is 200 or smaller. A value of Formula (D) is 15 or smaller.

Alkali-free glass

An alkali-free glass includes, in mol % in terms of oxides: SiO: 63-75%; AlO:10-16%; BO: larger than 0.5% and 5% or smaller; MgO: 0.1-15%; CaO: 0.1-12%; SrO: 0-8%; and BaO: 0-6%. [MgO]/[CaO] is larger than 1.5. 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 ηof 10dPa·s or higher.

A glass has a density of 2.60 g/cmor lower, a Young's modulus of 88 GPa or more, a strain point of 650 to 720° C., a temperature Tat which a glass viscosity reaches 10dPa·s of 1,320° C. or lower, a glass surface devitrification temperature (T) of T+20° C. or lower, and an average coefficient of thermal expansion of 30×10to 43×10/° C. at 50 to 350° C. The glass contains, as represented by mol % based on oxides, 50 to 80% of SiO, 8 to 20% of AlO, 0 to 0.5% in total of at least one kind of alkali metal oxide selected from the group consisting of LiO, NaO and KO, and 0 to 1% of PO.

Glass

The present invention relates to a glass substrate including a pair of main surfaces and an end surface, and having a surface layer diffusion Sn atom concentration of 2.0×10atomic/cmor more and 1.4×10atomic/cmor less in at least one of the main surfaces, the surface layer diffusion Sn atom concentration being obtained by subtracting an Sn atom concentration of an inside of the glass substrate from an Sn atom concentration of a surface layer of the glass substrate, in which the Sn atom concentration of a surface layer of the glass substrate is defined as an Sn atom concentration at a depth of 0.1 to 0.3 μm from the main surface and the Sn atom concentration of an inside of the glass substrate is defined as an Sn atom concentration at a depth of 9.0 to 9.2 μm from the main surface.

Glass substrate, black matrix substrate, and display panel

An alkali-free glass has a strain point of 650° C. or more, an average coefficient of thermal expansion at 50 to 350° C. of from 30×10to 45×10/° C., and a temperature Tat which a glass viscosity reaches 10dPa·s of from 1,500 to 1,800° C. The alkali-free glass contains, as represented by mol % based on oxides, SiO: from 62 to 70%, AlO: from 9 to 16% BO: from 0 to 12%, MgO: from 3 to 10%, CaO: from 4 to 12%, SrO: from 0 to 6%, and FeO: from 0.001 to 0.04%, provided that MgO+CaO+SrO+BaO is from 12 to 25%. The alkali-free glass has a β-OH value of from 0.35 to 0.85/mm.

An alkali free glass has an average coefficient of thermal expansion at 50 to 350° C. of 30×10to 43×10/° C., a Young's modulus of 88 GPa or more, a strain point of 650 to 725° C., a temperature Tat which a viscosity reaches 10dPa·s of 1,290° C. or lower, a glass surface devitrification temperature (T) of T+20° C. or lower, and a temperature Tat which the viscosity reaches 10dPa·s of 1,680° C. or lower. The alkali free glass contains, as represented by mol % based on oxides, 62 to 67% of SiO, 12.5 to 16.5% of AlO, 0 to 3% of BO, 8 to 13% of MgO, 6 to 12% of CaO, 0.5 to 4% of SrO, and 0 to 0.5% of BaO. MgO+CaO+SrO+BaO is 18 to 22%, and MgO/CaO is 0.8 to 1.33.

An alkali free glass has an average coefficient of thermal expansion at 50 to 350&#xb0; C. of 30&#xd7;10to 43&#xd7;10/&#xb0; C., a Young's modulus of 88 GPa or more, a strain point of 650 to 725&#xb0; C., a temperature Tat which a viscosity reaches 10dPa&#xb7;s of 1,290&#xb0; C. or lower, a glass surface devitrification temperature (T) of T+20&#xb0; C. or lower, and a temperature Tat which the viscosity reaches 10dPa&#xb7;s of 1,680&#xb0; C. or lower. The alkali free glass contains, as represented by mol % based on oxides, 62 to 67% of SiO, 12.5 to 16.5% of AlO, 0 to 3% of BO, 8 to 13% of MgO, 6 to 12% of CaO, 0.5 to 4% of SrO, and 0 to 0.5% of BaO. MgO+CaO+SrO+BaO is 18 to 22%, and MgO/CaO is 0.8 to 1.33.

To provide an alkali-free glass having a high specific elastic modulus, a suitable strain point, a low density, a not too low thermal expansion coefficient, a good clarity and a good solubility. An alkali-free glass, which comprises, as represented by mol % based on oxides, SiO: 62 to 70%, AlO: 11 to 14%, BO: 3 to 6%, MgO: 7 to 10%, CaO: 3 to 9%, SrO: 1 to 5% and BaO: 0 to 1%, wherein [SiO]+0.7[AlO]+1.2[BO]+0.5[MgO]+0.4[CaO]&#x2212;0.25[SrO]&#x2212;0.88[BaO] is at least 85, [SiO]+0.45[AlO]+0.21[BO]&#x2212;0.042[MgO]+0.042[CaO]+0.15[SrO]+0.38[BaO] is from 72 to 75, 0.4[SiO]+0.4[AlO]+0.25[BO]&#x2212;0.7[MgO]&#x2212;0.88[CaO]&#x2212;1.4[SrO]&#x2212;1.7[BaO] is at most 19, the specific modulus is at least 32 MN&#xb7;m/kg, the strain point is from 690 to 710&#xb0; C., the density is at most 2.54 g/cm, the average thermal expansion coefficient at from 50 to 350&#xb0; C. is at least 35&#xd7;10/&#xb0; C., and the temperature Tat which the glass viscosity reaches 10dPa&#xb7;s is from 1,610 to 1,680&#xb0; C.

To provide an alkali-free glass, of which the compaction is low, the strain point is high, and the ultraviolet transmittance is high, and which is easy to melt. An alkali-free glass, which comprises, as represented by mol % based on oxides, wherein MgO+CaO+SrO+BaO is from 12 to 22, and 4.84[FeO]+5.65[NaO]+4.03[KO]+4.55[SnO] is at most 0.55, and of which the compaction is at most 80 ppm.

The present invention relates to an alkali-free glass substrate, in which when two arbitrary sites in one main surface thereof are selected, an absolute value of a difference between a thermal shrinkage ratio in an arbitrary direction at one site and a thermal shrinkage ratio in a direction orthogonal to the arbitrary direction at another site is 2 ppm or less, provided that the thermal shrinkage ratio is calculated by measuring a deformation amount in a measuring direction of the glass substrate between before and after a heat treatment of raising a temperature from normal temperature to 600&#xb0; C. at 100&#xb0; C./hour, holding the glass substrate at 600&#xb0; C. for 80 minutes, and lowering the temperature from 600&#xb0; C. to normal temperature at 100&#xb0; C./hour.

Alkali-free glass substrate and method for manufacturing alkali-free glass substrate

The present invention relates to an alkali-free glass and a method for producing the same. More specifically, the present invention relates to an alkali-free glass suitable as a glass for substrates of various displays such as liquid crystal display, and a method for producing the same. According to the present invention, an alkali-free glass suitable as a glass for display substrates, in which inclusion of bubbles is greatly reduced by virtue of containing a refining agent and suppressing the stirring reboil, is obtained.

Alkali-free glass and method for producing the same

The present invention relates to an alkali-free glass substrate, having a strain point of 680&#xb0; C. or higher, a Young's modulus of 78 GPa or greater, an UV transmittance at a wavelength of 300 nm of from 40% to 85% in terms of 0.5 mm thickness, an in-plane distribution of the UV transmittance at a wavelength of 300 nm in a G6-sized substrate of 1% or less in terms of 0.5 mm thickness, an average cooling rate around the glass transition point obtained according to a rate cooling method of 400&#xb0; C./min or lower, and an in-plane distribution of the average cooling rate of 40&#xb0; C./min or less.

Alkali-free glass substrate and method for producing same

Provided is a non-alkali glass having a strain point of 680&#xb0; C. or higher, having an average thermal expansion coefficient of from 30&#xd7;10/&#xb0; C. to 45&#xd7;10/&#xb0; C. at from 50&#xb0; C. to 350&#xb0; C., containing, indicated by mass % on the basis of oxides: SiO: 54% to 66%, AlO: 10% to 27%, BO: 0.2% to 5.5%, MgO: 0% to 10%, CaO: 0% to 15%, SrO: 0% to 15%, BaO: 0% to 15%, and MgO+CaO+SrO+BaO: 8% to 25%, containing 600 mass ppm or less of NaO, and satisfying a mass ratio (NaO/BO) between NaO and BObeing from 0.001 to 0.3.

Non-alkali glass

The present invention relates to an alkali-free glass having a strain point of from 680 to 735&#xb0; C., an average thermal expansion coefficient at from 50 to 350&#xb0; C. of from 30&#xd7;10to 43&#xd7;10/&#xb0; C., and a specific gravity of 2.60 or less, and containing, indicated by mol % on the basis of oxides, SiO65 to 69%, AlO11.5 to 14%, BO3 to 6.5%, MgO 1 to 5%, CaO 7.5 to 12%, SrO 0 to 1%, BaO 0.5 to 6%, and ZrO0 to 2%.

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Tokyo, Japan

Hirofumi Tokunaga