US4156755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lithium containing ion exchange strengthened glass
Assignee: PPG Industries Inc
•
Filing: 1978-04-19
•
Granted: 1979-05-29
•
Expires: 1998-04-19
Abstract
Abstract Glasses having 59-62% by weight SiO 2 , 10-12% Na 2 O, 4-5.5% Li 2 O, 15-23% Al 2 O 3 , and 2-5% ZrO 2 have been found to be excellent for ion exchange strengthening below the strain point by exchanging the lithium ions with larger alkali metal ions such as sodium. Such glasses possess low melting temperatures, wide working ranges, and good chemical durability. The glasses are also free from corrosive volatile components, and sheets of such glasses resist devitrification when subjected to subsequent bending processes.
Inventors
- 👤 Dale W. Rinehart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:38
CPC Classifications
C; C03; C03C; C03C21/00; C03C21/001; C03C21/002; C03C3/00; C03C3/04; C03C3/076; C03C3/083; C03C3/085; C03C3/089; C03C3/091; Y; Y10; Y10T; Y10T428/00; Y10T428/31; Y10T428/315
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
130 words
A glass composition capable of being ion exchange strengthened below its strain point, consisting essentially of, by weight on the oxide basis: 59 to 63% -- SiO 2 10 to 13% -- Na 2 O 4 to 5.5% -- Li 2 O 15 to 23% -- Al 2 O 3 2 to 5% -- ZrO 2 and 0 to 5% total of non-essential components selected from the group consisting of MgO, MnO, TiO 2 , Sb 2 O 3 , As 2 O 3 , K 2 O, PbO, SO 3 , colorants, and mixtures thereof; wherein the sum of the weight percentages of Al 2 O 3 and ZrO 2 is 19 to 25%, and the ratio of Na 2 O to ZrO 2 is from 2.2 to 5.5.
Claim 2
Dependent Claim
130 words
A glass composition capable of being ion exchange strengthened below its strain point, consisting essentially of, by weight on the oxide basis: 59 to 63% -- SiO 2 10 to 13% -- Na 2 O 4 to 5.5% -- Li 2 O 15 to 23% -- Al 2 O 3 2 to 5% -- ZrO 2 and 0 to 5% total of non-essential components selected from the group consisting of MgO, MnO, TiO 2 , Sb 2 O 3 , As 2 O 3 , K 2 O, PbO, SO 3 , colorants, and mixtures thereof; wherein the sum of the weight percentages of Al 2 O 3 and ZrO 2 is 19 to 25%, and the ratio of Na 2 O to ZrO 2 is from 2.2 to 5.5.
Claim 3
Dependent Claim
35 words
The glass of claim 1 wherein at least 98% by weight of the total composition consists of SiO 2 , Na 2 O, Li 2 O, Al 2 O 3 , and ZrO 2 .
Claim 4
Dependent Claim
70 words
The glass of claim 2 wherein the composition consists essentially of, by weight on the oxide basis: 60 to 63% -- SiO 2 10 to 12% -- Na 2 O 4 to 5.5% -- Li 2 O 17 to 19% -- Al 2 O 3 3.5 to 5% -- ZrO 2 wherein the sum of the weight percentages of Al 2 O 3 and ZrO 2 is 21.5 to 24%.
Claim 5
Dependent Claim
166 words
An ion exchange strengthened glass article having a surface portion in compression and an interior portion in tension; the interior portion consisting essentially of, by weight on the oxide basis: 59to 63% -- SiO 2 10 to 13% -- Na 2 O 4 to 5.5% -- Li 2 O 15 to 23% -- Al 2 O 3 2 to 5% -- ZrO 2 and 0 to b 5% total of non-essential components selected from the group consisting of MgO, MnO, TiO 2 , Sb 2 O 3 , As 2 O 3 , K 2 O, PbO, SO 3 , colorants, and mixtures thereof; wherein the sum of the weight percentages of Al 2 O 3 and ZrO 2 is 19 to 25%, and the weight ratio of Na 2 O to ZrO 2 is from 2.2 to 5.5; the surface portion differing from the interior portion in a lower content of Li ions and a greater content of alkali metal ions larger than Li ions.
Claim 6
Dependent Claim
166 words
An ion exchange strengthened glass article having a surface portion in compression and an interior portion in tension; the interior portion consisting essentially of, by weight on the oxide basis: 59to 63% -- SiO 2 10 to 13% -- Na 2 O 4 to 5.5% -- Li 2 O 15 to 23% -- Al 2 O 3 2 to 5% -- ZrO 2 and 0 to b 5% total of non-essential components selected from the group consisting of MgO, MnO, TiO 2 , Sb 2 O 3 , As 2 O 3 , K 2 O, PbO, SO 3 , colorants, and mixtures thereof; wherein the sum of the weight percentages of Al 2 O 3 and ZrO 2 is 19 to 25%, and the weight ratio of Na 2 O to ZrO 2 is from 2.2 to 5.5; the surface portion differing from the interior portion in a lower content of Li ions and a greater content of alkali metal ions larger than Li ions.
Claim 7
Dependent Claim
43 words
The glass article of claim 4 wherein at least 98% by weight of the total composition of the interior portion of the glass consists of SiO 2 , Na 2 O, Li 2 O, Al 2 O 3 , and ZrO 2 .
Claim 8
Dependent Claim
78 words
The glass article of claim 5 wherein the composition of the interior portion of the glass consists essentially of, by weight on the oxide basis: 60 to 63% -- SiO 2 10 to 12% -- Na 2 O 4 to 5.5 -- Li 2 O 17 to 19% -- Al 2 O 3 3.5 to 5% -- ZrO 2 wherein the sum of the weight percentages of Al 2 O 3 and ZrO 2 is 21.5 to 24%.
Claim 9
Dependent Claim
18 words
The glass article of claim 4 wherein the alkali metal ions larger than Li ions include Na ions.
References Cited (Backward Citations)
US3790430A
Cited
US3218220A
Cited
US3533888A
Cited
US3357876A
Cited
US3433611A
Cited
US3485702A
Cited
US3752729A
Cited
US3615320A
Cited
US3529946A
Cited
US4015045A
Cited
US3985535A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-05-28 | 1982-11-27 | 1983-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-28 | 1986-11-27 | 1987-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-28 | 1990-11-27 | 1991-05-29 | $7700.00 | Window Closed / Lapsed |