Glass compositions having high thermal and chemical stability and methods of making thereof

• US 10,364,177 B2
• Filed: 05/06/2014
• Issued: 07/30/2019
• Est. Priority Date: 02/10/2006
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Danielson, Paul Stephen, Ellison, Adam James, Venkataraman, Natesan
• Primary Examiner(s): Bolden, Elizabeth A.
• Application Number:
  US14/270,796
• Publication Number:
  US 20140243186A1
• Time in Patent Office: 1,911 Days
• CPC Class Codes: C03B 17/06 Forming glass sheets
• CPC Class Codes: C03B 17/064 by the overflow downdraw fusion process; Isopipes therefor
• CPC Class Codes: C03C 3/091 containing aluminium
• CPC Class Codes: C03C 3/095 containing rare earths

Abstract

Described herein are alkali-free, boroalumino silicate glasses exhibiting desirable physical and chemical properties for use as substrates in flat panel display devices, such as, active matrix liquid crystal displays (AMLCDs). In accordance with certain of its aspects, the glasses possess good dimensional stability as a function of temperature.

Claims

1. An alkali metal-free glass comprising in mole percent on an oxide basis:

2. The glass of claim 1 wherein the glass has a Young'"'"'s modulus to density ratio greater than 30.0 GPa·

cm³/g.

3. The glass of claim 1 wherein the glass has a Young'"'"'s modulus to density ratio greater than 32.2 GPa·

cm³/g.

4. The glass of claim 1 wherein the As₂O₃ and Sb₂O₃ concentrations in the glass are each less than or equal to 0.005 mole percent.

5. The glass of claim 1 wherein the glass has a liquidus viscosity greater than or equal to 150,000 poise.

6. A liquid crystal display substrate comprising the glass of claim 1.

7. A method for producing alkali metal-free glass sheets by a downdraw process comprising selecting, melting, and fining batch materials so that the glass making up the sheets has the composition of claim 1, wherein:

(a) the fining is performed without the use of substantial amounts of arsenic; and

(b) a population of 50 sequential glass sheets produced by the downdraw process from the melted and fined batch materials has an average gaseous inclusion level of less than 0.10 gaseous inclusions/cubic centimeter, where each sheet in the population has a volume of at least 500 cubic centimeters.

8. The method of claim 7 wherein the downdraw process comprises a fusion draw process.

9. The method of claim 7 wherein the glass making up the sheets has a liquidus viscosity greater than or equal to 150,000 poise.

10. The method of claim 7 further comprising using the glass sheets as substrates for liquid crystal displays.