Dimensionally stable fast etching glasses

Patent metadata

Field	Value
Publication number	US-9802857-B2
Application number	US-201615048492-A
Country	US
Kind code	B2
Filing date	Feb 19, 2016
Priority date	Oct 31, 2014
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

Substantially alkali free glasses are disclosed with can be used to produce substrates for flat panel display devices, e.g., active-matrix liquid crystal displays (AMLCDs). The glasses have high annealing temperatures and etch rates. Methods for producing substantially alkali free glasses using a downdraw process (e.g., a fusion process) are also disclosed.

First claim

What is claimed is:

1. A glass comprising in mole percent on an oxide basis:
SiO 2 60-80,
Al 2 O 3 5-20,
B 2 O 3 0-10,
MgO 0-20,
CaO 0-20,
SrO 0-20,
BaO 0-20,
ZnO 0-20:

wherein the glass's composition satisfies the following relationship in which Al 2 O 3 , B 2 O 3 , MgO, CaO, SrO, and BaO are in mole percent:
−54.6147+(2.50004)*(Al 2 O 3 )+(1.3134)*(B 2 O 3 )+(1.84106)*(MgO)+(3.01223)*(CaO)+(3.7248)*(SrO)+(4.13149)*(BaO)≧23;

and wherein the glass has the following properties:
(i) an annealing temperature greater than or equal to 800° C.;
(ii) a Young's modulus greater than or equal to 82 GPa;
(iii) a T 200P less than or equal to 1750° C.;
(iv) a T 350 less than or equal to 1340° C.; and
(v) an average surface roughness as measured by atomic force microscopy of less than 0.5 nm.

2. The glass of claim 1 , wherein the glass's density is less than or equal to 2.7 g/cc and the glass's specific modulus is less than 34.

3. The glass of claim 2 , wherein the glass's specific modulus is between 30 and 34.

4. The glass of claim 1 , wherein the glass's (MgO+CaO+SrO+BaO)/Al 2 O 3 ratio is in the range of 1.0 and 1.6, where Al 2 O 3 , MgO, CaO, SrO, and BaO are in mole percent.

5. The glass of claim 1 , wherein the glass's T 200P is less than or equal to 1700° C.

6. The glass of claim 1 , wherein the glass's T 35kP is less than or equal to 1310° C.

7. The glass of claim 4 , wherein the glass's density <2.7 g/cc, the glass's T(200P)<1750° C., and the glass's T(35kP)<1340° C.

8. The glass of claim 4 , wherein the glass's density <2.7 g/cc, the glass's T(200P)<1750° C., and the glass's T(35kP)>1270° C.

9. The glass of claim 7 or claim 8 , wherein the glass is substantially free of alkalis.

10. The glass of claim 7 or claim 8 , wherein the glass's specific modulus is less than 34.

11. The glass of claim 10 , wherein the glass's specific modulus is between 30 and 34.

12. A liquid crystal display substrate comprising the glass of any of claim 1 or 2 - 8 .

Assignees

• Corning Inc

Inventors

• Bowden Bradley Frederick
• Ellison Adam James
• Kiczenski Timothy James

Classifications

• Y02P40/57

  Improving the yield, e-g- reduction of reject rates · CPC title

• G02F1/133302

  Rigid substrates, e.g. inorganic substrates · CPC title

• C03C4/00

  Compositions for glass with special properties · CPC title

• C03C3/091 Primary

  containing aluminium · CPC title

• C03C3/087

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