Thermally tempered glass element and use thereof

Patent metadata

Field	Value
Publication number	US-RE49895-E
Application number	US-202117526434-A
Country	US
Kind code	E1
Filing date	Nov 15, 2021
Priority date	Nov 26, 2015
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

A thermally tempered glass element is provided made of glass with two opposite faces that are under compressive stress of at least 40 MPa. The glass has a working point at which the glass has a viscosity of 10 4 dPa·s of at most 1350° C. The glass has a viscosity versus temperature profile and a coefficient of thermal expansion versus temperature profile of the glass are such that a variable (750° C.-T 13 )/(CTE Liq -CTEs Sol ) has a value of at most 5*10 6 K 2 . The CTE Liq is a coefficient of linear thermal expansion of the glass above a glass transition temperature T g , the CTE Sol is a coefficient of linear thermal expansion of the glass in a temperature range from 20° C. to 300° C., and the T 13 is a temperature at which the glass has a viscosity of 10 13 dPa·s.

First claim

What is claimed is:

1. A thermally tempered glass element, comprising:
glass with two opposite faces that are under compressive stress of at least 40 MPa,
wherein the glass has a working point at which the glass has a viscosity of 10 4 dPa·s of at most 1350° C.,
wherein the glass has a viscosity versus temperature profile and a coefficient of thermal expansion versus temperature profile of the glass are such that a variable
(750° C.−T 13 )/(CTE Liq −CTE Sol )

has a value of at most 5*10 6 K 2 ,
wherein CTE Liq is a coefficient of linear thermal expansion of the glass above a glass transition temperature T g ,
wherein CTE Sol is a coefficient of linear thermal expansion of the glass in a temperature range from 20° C. to 300° C.,
wherein T 13 is a temperature at which the glass has a viscosity of 10 13 dPa·s, and
wherein the glass has a composition that is free of B 2 O 3 , and
wherein the glass has a chemical resistance H, S, L of at least 2, 3, 3 or better, the chemical resistance being defined as hydrolytic class H according to ISO 719, acid class S according to DIN 12116, and alkali class L according to ISO 695.

2. The glass element of claim 1 , wherein the coefficient of linear thermal expansion CTE Sol is in a range from 3.5*10 −6 K −1 to 6*10 −6 K −1 .

3. The glass element of claim 1 , wherein the coefficient of linear thermal expansion CTE Liq is in a range from 11*10 −6 K −1 to 45*10 −6 K −1 .

4. The glass element of claim 1 , wherein the glass has a density of at least 2.4 grams per cubic centimeter.

5. The glass element of claim 1 , further comprising a coating on at least one of the two opposite faces.

6. The glass element of claim 5 , wherein the coating is a glass flux-based coating.

7. The glass element of claim 5 , wherein the coating has a coefficient of thermal expansion, CTE Coat , is adapted to the coefficient of thermal expansion CTE Sol of the glass so that an absolute value of a difference of thermal expansion coefficients, |ΔCTE|=|CTE Sol −CTE Coat |, is not more than 1 ppm/K.

8. The glass element of claim 7 , wherein the difference is not more than 0.5 ppm/K.

9. The glass element of claim 7 , wherein the difference is not more than 0.3 ppm/K.

10. The glass element of claim 1 , further comprising a thickness between the two faces that is between greater than or equal to 2 mm and less than or equal to 5 mm.

11. The glass element of claim 1 , further comprising a thickness between the two faces that is between greater than or equal to 3 mm and less than or equal to 5 mm.

12. The glass element of claim 1 , wherein the composition, in percent by weight, comprises:

SiO 2
60-80,

Al 2 O 3
 3-15,

Li 2 O
0-5,

Na 2 O
 0-10,

K 2 O
0-6,

MgO
0-8,

CaO
 0-10,

SrO
0-5,

TiO 2
      0-5, and

ZrO 2
0-9.

13. The glass element of claim 12 , wherein the composition further comprises one or more elements selected from a group consisting of refining agents, coloring agents, trace impurities inevitably contained in raw materials, and any combinations thereof, and wherein the one or more elements amount to a total of less than 2 wt %.

14. The glass element of claim 1 , wherein the composition, in percent by weight, comprises:

SiO 2
63-75,

Al 2 O 3
 8-21,

Li 2 O
0-5,

Na 2 O
 0-14,

K 2 O
0-5,

MgO
 0-12,

CaO
 0-18,

SrO
0-5,

TiO 2
      0-5, and

ZrO 2
0-9.

15. The glass element of claim 14 , wherein the composition further comprises one or more elements selected from a group consisting of refining agents, coloring agents, trace impurities inevitably contained in raw materials, and any combinations thereof, and wherein the one or more elements amount to a total of less than 2 wt %.

16. The glass element of claim 1 , wherein the composition, in percent by weight, comprises:

SiO 2
50-70,

Al 2 O 3
 3-25,

Li 2 O
0-8,

Na 2 O
0-7,

K 2 O
0-5,

MgO
0-5,

CaO
0-7,

SrO
0-5,

ZnO
0-3,

TiO 2
0-5,

ZrO 2
      0-5, and

Assignees

• Schott Ag

Inventors

• Schwall Michael
• Mix Christian
• Alkemper Jochen
• Thomas Peter

Classifications

• C03C3/097 Primary

  containing phosphorus, niobium or tantalum · CPC title

• C03B32/02

  Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles {(C03B27/012 takes precedence)} · CPC title

• C03C8/24

  Fusion seal compositions being frit compositions having non-frit additions, i.e. for use as seals between dissimilar materials, e.g. glass and metal; Glass solders · CPC title

• C03C3/087 Primary

  containing calcium oxide, e.g. common sheet or container glass · CPC title

• C03B27/012

  by heat treatment, e.g. for crystallisation; Heat treatment of glass products before tempering by cooling (C03B27/008, C03B27/016 take precedence) · CPC title