阅读说明：本技术 化学耐用的不含锂玻璃组合物 (Chemically durable lithium-free glass compositions ) 是由 V·博途 M·J·德内卡 N·T·罗恩罗斯 A·坦迪亚 K·D·瓦尔吉斯 于 2020-04-28 设计创作，主要内容包括：公开了化学耐用的玻璃组合物。在实施方式中,玻璃组合物包含：48摩尔％至61摩尔％SiO-(2)；0摩尔％至1摩尔％Al-(2)O-(3)；7摩尔％至20摩尔％B-(2)O-(3)；9摩尔％至16摩尔％R-(2)O,式中,R-(2)O是玻璃组合物中存在的碱性氧化物的总和；9摩尔％至15摩尔％Na-(2)O；以及8摩尔％至21摩尔％ZnO。玻璃组合物可以基本不含Li-(2)O。RO(摩尔％)<0.5x ZnO(摩尔％),式中,RO是玻璃组合物中的碱土氧化物的总和。玻璃组合物在约20℃至约300℃的温度范围上的平均热膨胀系数是75x 10～(-7)/℃至88x 10～(-7)/℃。玻璃组合物包括小于或等于660℃的软化点。玻璃组合物包括根据ISO 720:1985的等级HGA1或等级HGA2的抗水解性。(Chemically durable glass compositions are disclosed. In an embodiment, a glass composition comprises: 48 to 61 mol% SiO 2 (ii) a 0 mol% to 1 mol% Al 2 O 3 (ii) a7 to 20 mol% B 2 O 3 (ii) a9 to 16 mol% R 2 O, wherein R is 2 O is the sum of the basic oxides present in the glass composition; 9 to 15 mol% Na 2 O; and 8 to 21 mol% ZnO. The glass composition may be substantially free of Li 2 And O. RO (mol%)<0.5XZnO (mol%), wherein RO isThe sum of the alkaline earth oxides in the glass composition. The glass composition has an average coefficient of thermal expansion of 75x10 over a temperature range of about 20 ℃ to about 300 ℃ ‑7 /° c to 88x10 ‑7 V. C. The glass composition includes a softening point less than or equal to 660 ℃. The glass composition comprises a resistance to hydrolysis according to ISO720:1985 of grade HGA1 or grade HGA 2.)

1. A glass composition comprising:

greater than or equal to 48 mol% and less than or equal to 61 mol% SiO₂；

0 mol% or more and 1 mol% or less of Al₂O₃；

Greater than or equal to 7 mol% and less than or equal to 20 mol% B₂O₃；

Greater than or equal to 9 mol% and less than or equal to 16 mol% R₂O, wherein R is₂O is the sum of the basic oxides present in the glass composition;

9 mol% or more and 15 mol% or less of Na₂O; and

greater than or equal to 8 mol% and less than or equal to 21 mol% ZnO, wherein:

the glass composition is substantially free of Li₂O；

RO (mol%) <0.5xZnO (mol%), wherein RO is the sum of alkaline earth oxides MgO, CaO, BaO and SrO present in the glass composition;

the glass composition has an average coefficient of thermal expansion of greater than or equal to 75x10 over a temperature range from about 20 ℃ to about 300 ℃^-788x10 or less per DEG C^-7/℃；

The glass composition comprises a softening point less than or equal to 660 ℃; and

the glass composition comprises a resistance to hydrolysis according to ISO720:1985 of grade HGA1 or grade HGA 2.

2. The glass composition of claim 1, wherein:

SiO₂greater than or equal to 52 mol% and less than or equal to 61 mol%;

B₂O₃greater than or equal to 12 mol% and less than or equal to 17 mol%; and

ZnO is 8 mol% or more and 16 mol% or less.

3. The glass composition of claim 2, wherein Al is₂O₃Greater than or equal to 0.1 mol% and less than or equal to 1.0 mol%.

4. The glass composition of claim 2 or 3, wherein B₂O₃12 mol% or more and 15 mol% or less.

5. The glass composition of any of claims 2-4, wherein R₂O is less than or equal to 15 mol%.

6. The glass composition of any of claims 2-5, wherein Na₂O is 9 mol% or more and 13 mol% or less.

7. The glass composition of any of claims 2-6, wherein ZnO is greater than or equal to 9 mol.% and less than or equal to 15 mol.%.

8. The glass composition of any of claims 2-7, further comprising greater than or equal to 1 mol.% and less than or equal to 5 mol.% K₂O。

9. The glass of any of claims 2 to 7, wherein the glass composition is substantially free of K₂O。

10. The glass composition of any of claims 2-9, wherein RO is less than or equal to 5 mol.%.

11. The glass composition of any of claims 2-10, wherein a total amount of MgO (mol%) + SrO (mol%) is greater than or equal to 0.5 mol% and less than or equal to 4 mol%.

12. The glass composition of any of claims 2-11, further comprising greater than or equal to 0.5 mol% and less than or equal to 2.5 mol% SrO.

13. The glass composition of any of claims 2-11, wherein the glass composition is substantially free of SrO.

14. The glass composition of any of claims 2-13, further comprising greater than or equal to 0.5 mol.% and less than or equal to 2.5 mol.% MgO.

15. The glass composition of any of claims 2-13, wherein the glass composition is substantially free of MgO.

16. The glass composition of any of claims 2-15, wherein the glass composition comprises greater than 0.1 mol% and less than or equal to 1.5 mol% TiO₂And ZrO₂At least one of (1).

17. The glass composition of any of claims 2-16, wherein the glass composition comprises a liquidus viscosity greater than 90 kilopoise (kP).

18. The glass composition of any of claims 2-17, wherein the glass composition has a weight loss of less than or equal to 10mg/cm based on at least one of an alkali test or an acid test²。

19. The glass composition of claim 1, wherein:

SiO₂greater than or equal to 48 mol% and less than or equal to 55 mol%; and

ZnO is not less than 13 mol% and not more than 21 mol%, wherein ZnO (mol%) and R₂The ratio of O (mol%) is 0.75 or more and 2.0 or less.

20. The glass composition of claim 19, wherein Al is₂O₃Greater than or equal to 0.1 mol% and less than or equal to 1.0 mol%.

21. The glass composition of claim 19 or 20, wherein B₂O₃12 mol% or more and 17 mol% or less.

22. The glass composition of any of claims 19-21, further comprising greater than or equal to 1 mol.% and less than or equal to 3 mol.% K₂O。

23. The glass composition of any of claims 19-21, wherein the glass composition is substantially free of K₂O。

24. The glass composition of any of claims 19-23, wherein RO is less than or equal to 10 mol.%.

25. The glass composition of any of claims 19-24, wherein a total amount of MgO (mol%) + SrO (mol%) is greater than or equal to 0.5 mol% and less than or equal to 10 mol%.

26. The glass composition of any of claims 19-25, further comprising greater than or equal to 0.5 mol.% and less than or equal to 5.0 mol.% SrO.

27. The glass composition of any of claims 19-25, wherein the glass composition is substantially free of SrO.

28. The glass composition of any of claims 19-27, further comprising greater than or equal to 0.5 mol.% and less than or equal to 5.0 mol.% MgO.

29. The glass composition of any of claims 19-27, wherein the glass composition is substantially free of MgO.

30. The glass composition of any one of claims 19-29, further comprising greater than or equal to 0.5 mol.% and less than or equal to 5.0 mol.% CaO.

31. The glass composition of any of claims 19-30, wherein the glass composition comprises greater than 0.1 mol% and less than or equal to 1.5 mol% TiO₂And ZrO₂At least one of (1).

32. The glass composition of any of claims 19-31, wherein the glass composition comprises a liquidus viscosity greater than 1 kpoise (kP) and less than or equal to 50 kP.

33. The glass composition of any of claims 19-32, wherein the glass composition has a weight loss of less than or equal to 10mg/cm based on at least one of an alkali test or an acid test²。

34. A glass composition comprising:

greater than or equal to 66 mol% and less than or equal to 74 mol% SiO₂；

3 mol% or more and 7 mol% or less of Al₂O₃；

Greater than or equal to 11 mol% and less than or equal to 23 mol% R₂O, wherein R is₂O is the sum of the basic oxides (mol%) present in the glass composition;

11 mol% or more and 18 mol% or less of Na₂O; and

less than or equal to 3.0 mol% ZnO;

greater than or equal to 2.5 mol% and less than or equal to 5 mol% F₂Wherein:

the glass composition is substantially free of Li₂O；

Glass combinationHas an average coefficient of thermal expansion of greater than or equal to 80x10 over a temperature range of about 20 ℃ to about 300 ℃^-7V. and less than or equal to 92x10^-7/℃；

The glass composition comprises a softening point less than or equal to 680 ℃; and

the glass composition comprises a resistance to hydrolysis according to ISO720:1985 of grade HGA1 or grade HGA 2.

35. The glass composition of claim 34, further comprising greater than or equal to 0.1 mol% and less than or equal to 6 mol% B₂O₃。

36. The glass composition of claim 34 or 35, wherein the glass composition is substantially free of P₂O₅。

37. The glass composition of any of claims 34-36, further comprising greater than or equal to 0.5 mol.% and less than or equal to 4 mol.% K₂O。

38. The glass composition of any of claims 34-37, wherein the glass composition comprises a liquidus viscosity greater than 200 kpoise (kP).

39. The glass composition of any of claims 34-38, wherein the glass composition has a weight loss of less than or equal to 10mg/cm based on at least one of an alkali test or an acid test²。

Technical Field

The present description relates generally to chemically durable glass compositions, and more particularly to chemically durable glass compositions that have good resistance to hydrolysis and that are substantially free of lithium and lithium-containing compounds.

Technical Field

Glass is widely used in a variety of products, from consumer electronics devices to pharmaceutical packaging materials, due to its optical properties, ability to form and maintain a hermetic seal, and/or relative inertness.

As glass continues to be used in a variety of products, there is also a need to provide glass compositions that can be shaped or formed into complex geometries. However, the glass properties of the materials that make them desirable for certain applications may also hinder the ability to form glass into complex 3-dimensional shapes.

Thus, there is a need for alternative glass compositions that are chemically durable and can be easily re-molded from stock form into 3-dimensional shapes.

Background

Disclosure of Invention

According to aspect 1a 1, the glass composition may comprise: greater than or equal to 48 mol% and less than or equal to 61 mol% SiO₂(ii) a 0 mol% or more and 1 mol% or less of Al₂O₃(ii) a Greater than or equal to 7 mol% and less than or equal to 20 mol% B₂O₃(ii) a Greater than or equal to 9 mol% and less than or equal to 16 mol% R₂O, wherein R is₂O is the sum of the basic oxides present in the glass composition; 9 mol% or more and 15 mol% or less of Na₂O; and greater than or equal to 8 mol% and less than or equal to 21 mol% ZnO; wherein: the glass composition is substantially free of Li₂O; RO (mol%)<0.5xZnO (mol%), wherein RO is the sum of the alkaline earth oxides MgO, CaO, BaO and SrO present in the glass composition; the glass composition has an average coefficient of thermal expansion greater than or equal to 75x10 over a temperature range from about 20 ℃ to about 300 ℃^-788x10 or less per DEG C^-7/° c; the glass composition comprises a softening point less than or equal to 660 ℃; and the glass composition comprises a resistance to hydrolysis according to ISO720:1985 of grade HGA1 or grade HGA 2.

A2 nd aspect includes the glass composition according to aspect 1a 1, wherein: SiO 2₂Greater than or equal to 52 mol% and less than or equal to 61 mol%; b is₂O₃Greater than or equal to 12 mol% and less than or equal to 17 mol%; and ZnO is greater than or equal to 8 mol% and less than or equal to 16 mol%.

Aspect 3 includes the glass composition according to aspect 2A 2, wherein Al₂O₃Greater than 0.1 mol% and less than or equal to 1.0 mol%.

The 4 th aspect includes the glass composition according to the 2 nd aspect A2 or the 3 rd aspect A3, wherein Al₂O₃Greater than 0.1 mol% and less than or equal to 0.7 mol%.

The 5 th aspect A5 includes the 2 nd to 4 th aspects A2-A5 glass composition wherein B₂O₃12 mol% or more and 15 mol% or less％。

The 6 th aspect A6 includes the glass composition according to any one of the 2 nd to 5 th aspects A2-A5, wherein R₂O is less than or equal to 15 mol%.

The 7 th aspect A7 includes the glass composition according to any one of the 2 nd to 6 th aspects A2-A6, wherein R₂O is less than or equal to 14 mol%.

The 8 th aspect A8 includes the glass composition according to any one of the 2 nd to 7 th aspects A2-A7, wherein Na₂O is 9 mol% or more and 13 mol% or less.

The 9 th aspect A9 includes the glass composition according to any one of the 2 nd to 8 th aspects A2-A8, wherein Na₂O is 9 mol% or more and 12 mol% or less.

Aspect 10 a10 includes the glass composition according to any one of aspects 2 to 9 a2-a9 wherein the ZnO is greater than or equal to 9 mol% and less than or equal to 15 mol%.

11 th aspect a11 includes a glass composition according to any one of 2 nd to 10 th aspects a2-a10 that includes greater than or equal to 1 mol% and less than or equal to 5 mol% K₂O。

Aspect 12A 12 includes the glass composition according to any one of aspects 2 through 11A 2-A11, further including greater than or equal to 1 mol% and less than or equal to 2.5 mol% K₂O。

Aspect 13A 13 includes the glass composition according to any one of aspects 2 through 12A 2-A12, wherein the glass composition is substantially free of K₂O。

A14 th aspect includes the glass composition according to any one of aspects 2 through 13 a2-a13, wherein RO is less than or equal to 5 mol.%.

The 15 th aspect a15 includes the glass composition according to any one of the 2 nd to 14 th aspects a2-a14 wherein the total amount of MgO (mol%) + SrO (mol%) is greater than or equal to 0.5 mol% and less than or equal to 4 mol%.

Aspect 16 a16 includes a glass composition according to any one of aspects 2 to 15 a2-a15 further including greater than or equal to 0.5 mol% and less than or equal to 2.5 mol% SrO.

Aspect 17 a17 includes a glass composition according to any one of aspects 2 to 16 a2-a16 further including greater than or equal to 0.5 mol% and less than or equal to 2.0 mol% SrO.

Aspect 18 a18 includes a glass composition according to any one of aspects 2 to 17 a2-a17 wherein the glass composition is substantially free of SrO.

Aspect 19 a19 includes the glass composition according to any one of aspects 2-18 a2-a18 further including greater than or equal to 0.5 mol% and less than or equal to 2.5 mol% MgO.

Aspect 20 a20 includes the glass composition according to any one of aspects 2-21 a2-a19 further including greater than or equal to 0.5 mol% and less than or equal to 2.0 mol% MgO.

Aspect 21 a21 includes the glass composition according to any one of aspects 2-20 a2-a20, wherein the glass composition is substantially free of MgO.

Aspect 22A 22 includes the glass composition according to any one of aspects 2 to 21A 2-A21, wherein the glass composition includes greater than 0.1 mol% and less than or equal to 1.5 mol% TiO₂And ZrO₂At least one of (1).

Aspect 23 a23 includes the glass composition according to any one of aspects 2-22 a2-a22, wherein the glass composition includes a liquidus viscosity greater than 90 kilopoise (kP).

Aspect 24 a24 includes the glass composition according to any one of aspects 2-23 a2-a23, wherein the glass composition includes a molding temperature of less than 630 ℃.

The 25 th aspect A25 includes the glass composition according to any one of the 2 nd to 24 th aspects A2-A24, wherein the glass composition has a weight loss of less than or equal to 10mg/cm according to the alkali test²。

Aspect 26A 26 includes a glass composition according to any one of aspects 2 to 25A 2-A25, wherein the weight of the glass composition is according to the acid testLoss less than or equal to 10mg/cm²。

Aspect 27 a27 includes the glass composition of aspect 1, wherein: SiO 2₂Greater than or equal to 48 mol% and less than or equal to 55 mol%; and ZnO is greater than or equal to 13 mol% and less than or equal to 21 mol%; wherein ZnO (mol%) is in contact with R₂The ratio of O (mol%) is 0.75 or more and 2.0 or less.

28 th aspect A28 includes the glass composition according to 27 th aspect A27 wherein the ZnO (mole%) is with R₂The ratio of O (mol%) is 1.0 or more.

The 29 th aspect A29 includes the glass composition according to any one of the 27 th to 28 th aspects A27-A28, wherein SiO₂Greater than or equal to 49 mol% and less than or equal to 52 mol%.

A30 th aspect includes the glass composition according to any one of aspects A27-A29 of 27 th to 29 th, wherein Al₂O₃Greater than 0.1 mol% and less than or equal to 1.0 mol%.

The 31 st aspect includes the glass composition according to any one of the 27 th to 30 th aspects a27-a30, wherein Al₂O₃Greater than 0.1 mol% and less than or equal to 0.7 mol%.

The 32 nd aspect A32 includes the glass composition according to any one of the 27 th to 31 th aspects A27-A31, wherein B₂O₃12 mol% or more and 17 mol% or less.

The 33 rd aspect A33 includes the glass composition according to any one of the 27 th to 32 th aspects A27-A32, wherein B₂O₃Greater than or equal to 14 mol% and less than or equal to 17 mol%.

Aspect 34A 34 includes a glass composition according to any one of aspects 27 to 33A 27-A33, wherein R₂O is less than or equal to 14 mol%.

The 35 th aspect A35 includes the glass composition according to any one of the 27 th to 34 th aspects A27-A34, wherein R₂O is less than or equal to 13 mol%.

The 36 thAspect A36 includes the glass composition according to any one of aspects A27-A35 of 27 to 35, wherein Na₂O is 9 mol% or more and 14 mol% or less.

The 37 th aspect A37 includes the glass composition according to any one of the 27 th to 36 th aspects A27-A36, wherein Na₂O is 10 mol% or more and 13 mol% or less.

The 38 th aspect a38 includes the glass composition according to any one of the 27 th to 37 th aspects a27-a37 wherein the ZnO is greater than or equal to 14 mol% and less than or equal to 20 mol%.

39 th aspect a39 includes the glass composition according to any one of aspects a27-a38 of 27 th through 38 th aspects, wherein the ZnO is greater than or equal to 15 mol% and less than or equal to 20 mol%.

Aspect 40 a40 includes a glass composition according to any one of aspects 27 to 39 a27-a39 including greater than or equal to 1 mol% and less than or equal to 3 mol% K₂O。

41 st aspect A41 includes the glass composition according to any one of aspects A27-A40 of 27 through 40, further including greater than or equal to 1 mol% and less than or equal to 2.5 mol% K₂O。

Aspect 42A 42 includes the glass composition according to any one of aspects 27 to 41A 27-A41, wherein the glass composition is substantially free of K₂O。

Aspect 43A 43 includes the glass composition according to any one of aspects 27 to 42A 27-A42 wherein RO is less than or equal to 10 mol%.

Aspect 44A 44 includes the glass composition according to any one of aspects 27 to 43A 27-A43 wherein RO is less than or equal to 5 mol%.

The 45 th aspect a45 includes the glass composition according to any one of aspects a27-a44 wherein the total amount of MgO (mol%) + SrO (mol%) is greater than or equal to 0.5 mol% and less than or equal to 10 mol%.

A46 th aspect a46 includes the glass composition according to any one of aspects a27-a45 of claims 27 through 45, wherein the total amount of MgO (mol%) + SrO (mol%) is greater than or equal to 0.5 mol% and less than or equal to 5 mol%.

The 47 th aspect a47 includes the glass composition according to any one of aspects a27-a46, where the total amount of MgO (mol%) + SrO (mol%) is greater than or equal to 0.5 mol% and less than or equal to 2 mol%.

Aspect 48 a48 includes a glass composition according to any one of aspects 27 to 47 a27-a47 further including greater than or equal to 0.5 mol% and less than or equal to 5.0 mol% SrO.

Aspect 49 a49 includes a glass composition according to any one of aspects 27 to 48 a27-a48 further including greater than or equal to 0.5 mol% and less than or equal to 2.5 mol% SrO.

Aspect 50A 50 includes a glass composition according to any one of aspects 27 to 49A 27-A49 wherein the glass composition is substantially free of SrO.

The 51 st aspect a51 includes the glass composition according to any one of the 27 th to 50 th aspects a27-a50, further comprising greater than or equal to 0.5 mol% and less than or equal to 5.0 mol% MgO.

Aspect 52 a52 includes the glass composition according to any one of aspects 27-51 a27-a51, further including greater than or equal to 0.5 mol% and less than or equal to 2.5 mol% MgO.

Aspect 53A 53 includes the glass composition according to any one of aspects 27 through 52A 27-A52, wherein the glass composition is substantially free of MgO.

Aspect 54 a54 includes the glass composition according to any one of aspects 27-53 a27-a53 further including greater than or equal to 0.5 mol% and less than or equal to 5.0 mol% CaO.

The 55 th aspect a55 includes the glass composition according to any one of the 27 th to 54 th aspects a27-a54, further including greater than or equal to 0.5 mol% and less than or equal to 2.5 mol% CaO.

56 th aspect A56 includes a glass composition according to any one of aspects A27-A55 from 27 th to 55 th, wherein the glass composition includesContaining more than 0.1 mol% and less than or equal to 1.5 mol% of TiO₂And ZrO₂At least one of (1).

A57 th aspect a57 includes the glass composition according to any one of aspects a27-a56 of 27 through 56, wherein the glass composition includes a liquidus viscosity greater than 1 kilopoise (kP) and less than or equal to 50 kP.

Aspect 58 a58 includes the glass composition according to any one of aspects 27-57 a27-a57, wherein the glass composition includes a molding temperature of less than 620 ℃.

59 th aspect A59 includes the glass composition according to any one of aspects A27-A58 of 27 through 58, wherein the glass composition has a weight loss of less than or equal to 10mg/cm according to the alkali test²。

Aspect 60A 60 includes a glass composition according to any one of aspects 27 to 59A 27-A59, wherein the glass composition has a weight loss of less than or equal to 10mg/cm according to the acid test²。

According to aspect 61 a61, the glass composition comprises: greater than or equal to 66 mol% and less than or equal to 74 mol% SiO₂(ii) a3 mol% or more and 7 mol% or less of Al₂O₃(ii) a Greater than or equal to 11 mol% and less than or equal to 23 mol% R₂O, wherein R is₂O is the sum (mole%) of the basic oxides present in the glass composition; 11 mol% or more and 18 mol% or less of Na₂O; less than or equal to 3.0 mol% ZnO; and greater than or equal to 2.5 mol% and less than or equal to 5 mol% F₂(ii) a Wherein: the glass composition is substantially free of Li₂O; the glass composition has an average coefficient of thermal expansion greater than or equal to 80x10 over a temperature range from about 20 ℃ to about 300 ℃^-7V. and less than or equal to 92x10^-7/° c; the glass composition comprises a softening point less than or equal to 680 ℃; and the glass composition comprises a resistance to hydrolysis according to ISO720:1985 of grade HGA1 or grade HGA 2.

The 62 nd aspect A62 includes the 61 st aspect A61 glass composition wherein the SiO₂Greater than or equal to 70 mol%And 73 mol% or less.

The 63 st aspect A63 includes the glass composition according to any one of the 61 st to 62 th aspects A61-A62, wherein Al₂O₃5 mol% or more and 7 mol% or less.

Aspect 64A 64 includes the glass composition according to any one of aspects 61-63A 61-A63 further comprising greater than or equal to 0.1 mol% and less than or equal to 6 mol% B₂O₃。

The 65 th aspect a65 includes the glass composition according to any one of the 61 st to 64 th aspects a61-a64, further comprising greater than or equal to 0.3 mol% and less than or equal to 3 mol% B₂O₃。

Aspect 66A 66 includes the glass composition according to any one of aspects 61-65A 61-A65, wherein the glass composition is substantially free of P₂O₅。

67 th aspect A67 includes the glass composition according to any one of aspects A61-A66 of 61 th to 66 th aspects, wherein Na₂O is 12 mol% or more and 16 mol% or less.

68 th aspect A68 includes the glass composition according to any one of 61 th to 67 th aspects A61-A67, further comprising greater than or equal to 0.5 mol% and less than or equal to 4 mol% K₂O。

69 th aspect A69 includes the glass composition according to any one of 61 th to 68 th aspects A61-A68, wherein K₂O is 0.75 mol% or more and 1.5 mol% or less.

Aspect 70 a70 includes the glass composition according to any one of aspects 61-69 a61-a69, wherein the glass composition includes a liquidus viscosity greater than 200 kilopoise (kP).

The 71 th aspect a71 includes the glass composition according to any one of the 61 st to 70 th aspects a61-a70, wherein the glass composition includes a molding temperature of less than 620 ℃.

72 th aspect A72 includes a glass composition according to any one of 61 th to 71 th aspects A61-A71, wherein the glass composition is based on an alkaliTest that the glass composition has a weight loss of less than or equal to 10mg/cm²。

73 th aspect A73 includes the glass composition according to any one of 61 th to 72 th aspects A61-A72, wherein the glass composition has a weight loss of less than or equal to 10mg/cm according to the acid test²。

Additional features and advantages of the glass compositions described herein are set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows, the claims, as well as the appended drawings.

It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments described herein and together with the description serve to explain the principles and operations of the claimed subject matter.

Detailed Description

Reference will now be made in detail to various embodiments of chemically durable lithium-free glass compositions. According to one embodiment, a chemically durable glass composition comprises: 48 to 61 mol% SiO₂(ii) a 0 mol% to 1 mol% Al₂O₃(ii) a7 to 20 mol% B₂O₃(ii) a9 to 16 mol% R₂O, wherein R is₂O is the sum of the basic oxides present in the glass composition; 9 to 15 mol% Na₂O; and 8 to 21 mol% ZnO. The glass composition may be substantially free of Li₂And O. The RO content of the glass composition may satisfy the following relationship: RO (mol%)<0.5x ZnO (mol%), wherein RO is the sum of alkaline earth oxides in the glass composition. The glass composition has an average coefficient of thermal expansion of 75x10 over a temperature range of about 20 ℃ to about 300 ℃^-7/° c to 88x10^-7V. C. The glass composition includes a softening point less than or equal to 660 ℃. The glass composition comprises a resistance to hydrolysis according to ISO720:1985 of grade HGA1 or grade HGA 2. Various embodiments of the glass compositions and their properties will now be described in further detail herein with specific reference to illustrative examples.

As used herein, the term "softening point" refers to a viscosity of the glass composition of 1x10^7.6Temperature at poise.

As used herein, the term "annealing point" refers to a viscosity of the glass composition of 1x10¹³Temperature at poise.

As used herein, the terms "strain point" and "T_{Strain of}"means that the viscosity of the glass composition is 3x10¹⁴Temperature at poise.

As used herein, the term "molding temperature" refers to a viscosity of the glass of 1x10^8.8Temperature at poise.

As used herein, the term "liquidus temperature" refers to the maximum temperature at which crystals in a glass melt can coexist in thermodynamic equilibrium with molten glass.

As used herein, the term "liquidus viscosity" refers to the viscosity of the glass at the onset of devitrification (i.e., the liquidus temperature).

As used herein, the term "CTE" refers to the coefficient of thermal expansion of the glass composition over a temperature range of about 20 ℃ to about 300 ℃.

In embodiments of the glass compositions described herein, constituent components (e.g., SiO) unless otherwise specified₂、Al₂O₃Etc.) are specified as mole percent (mol%) based on the oxide.

The terms "free" and "substantially free," when used to describe the concentration of a particular constituent component in a glass composition and/or the absence of the particular constituent component, mean that no constituent component is intentionally added to the glass composition. However, the glass composition may contain trace amounts of this constituent component as a contaminant or in an indeterminate amount, which is less than 0.05 mole percent.

As used herein, the term "chemical durability" refers to the ability of a glass composition to resist degradation when exposed to certain chemical conditions. Specifically, the glass compositions described herein were evaluated for chemical durability in acidic solutions, alkaline solutions, and water. The resistance of Glass to decomposition in water is determined according to ISO720:1985, entitled "Glass- -Hydrolytic resistance of Glass grains at 121degrees C- -Method of test and classification of Glass-Glass particles at 121degrees Celsius- -test Method and classification". The resistance of the glass to decomposition in acid was determined by: a 2.54cm x5.08 inch x 1mm thick sample of the glass composition was immersed in a5 wt% aqueous solution of HCl (95 ℃, for 24 hours) (hereinafter referred to as the acid test). The weight of the sample was measured before and after immersion and the weight loss per unit area (i.e., (initial weight-final weight)/total surface area (cm) was determined²)). The weight loss is less than 10mg/cm²The sample of (a) is considered to be resistant to decomposition in acid. The resistance of the glass to decomposition in alkaline solution was determined by: a 2.54cm x5.08 inch x 1mm thick sample of the glass composition was immersed in a5 wt% aqueous solution of NaOH (95 ℃, for 6 hours) (hereinafter referred to as the alkali test). The weight of the sample was measured before and after immersion and the weight loss per unit area (i.e., (initial weight-final weight)/total surface area (cm) was determined²)). The weight loss is less than 10mg/cm²The sample of (a) is considered to be resistant to decomposition in alkaline solution.

Strain and anneal points were measured according to the beam bending viscosity method, which measures inorganic glasses from 10 according to ASTM C598¹²To 10¹⁴Viscosity of poise as a function of temperature.

The softening point and the molding temperature were measured according to the parallel-set viscometry, which measures the inorganic glass from 10⁷To 10⁹Viscosity as a function of temperature for poise is similar to ASTM C1351M.

The liquidus temperature is measured by the gradient furnace method according to ASTM C829-81.

Ranges can be expressed herein as from "about" another particular value, and/or to the end of a range. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

Directional terminology used herein, such as upper, lower, right, left, front, rear, top, bottom, is for reference only to the accompanying drawings and is not intended to imply absolute orientation.

Unless specifically stated otherwise, any methods described herein should not be construed as requiring that their steps be performed in a particular order, or that any apparatus be specifically oriented. Accordingly, if a method claim does not actually recite an order to be followed by its steps, or any apparatus claim does not actually recite an order or orientation to individual components, or no further limitation to a specific order is explicitly stated in the claims or specification, or a specific order or orientation is recited to components of an apparatus, then no order or orientation should be inferred, in any respect. The same applies to any possible explicative basis not explicitly stated, including: logic for setting steps, operational flows, component orders, or component orientations; general meaning derived from grammatical structures or punctuation; and the number or type of embodiments described in the specification.

As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a" or "an" element includes aspects having two or more such elements, unless the context clearly indicates otherwise.

The glass composition in stock form (e.g., sheet, tube, rod, pear, etc.) may be remolded to form a final glass article having a complex 3-dimensional shape. For example, the glass stock tubing may be re-molded into glass containers for containing liquid products, and the glass sheets may be re-molded to form cover glasses for electronic devices or optical components (e.g., lenses or cones, etc.) that may be integrated into electronic devices, but is not limited thereto. Thus, it is desirable that the glass composition have a relatively low softening point (as well as other relatively low characteristic temperatures, such as strain point, annealing point, and mold point) to facilitate remolding. In particular, the lower performance temperature increases the ease of remoulding the glass composition into the preferred form and also extends the useful life of the mould in contact with the glass. In particular, the lower characteristic temperature of the glass being re-molded reduces the temperature of the re-molding process, which in turn reduces oxidation of the metal parts of the mold and minimizes chemical reactions between the mold and the glass composition.

Can be obtained by, for example, adding Li to the glass₂Lithium in the form of O lowers the characteristic temperature of the glass. However, it has been found that lithium ions in the glass are highly mobile, which may have adverse effects when the glass is used in certain applications. For example, when the final glass article is intended for use in applications requiring contact with a liquid, such as when the glass composition is used to form a pharmaceutical container or package or when the glass composition is used in an optical component in contact with a liquid, highly mobile lithium ions may leach from the glass composition and enter the liquid, or the composition of the liquid deteriorates or otherwise changes. Alternatively or additionally, when the final glass article is used in an application where a coating (e.g., a metalized coating) is applied to the final glass article, lithium ions from the glass composition may migrate into the coating and degrade the coating properties.

Disclosed herein are two glass composition spaces that define glass compositions that can alleviate the above-mentioned problems. In particular, the glass compositions of these composition spaces have good hydrolysis resistance and low characteristic problems, so that the glass compositions can be easily softened and molded into a desired shape.

The composition space A: lithium-free high ZnO glass composition

The glass composition in composition space A contains SiO₂、B₂O₃Alkali oxide (R)₂O) and ZnO, which may provide the glass composition with: lower coefficient of thermal expansion (e.g., less than or equal to 88x10 over a temperature range of about 20 ℃ to about 300 ℃)^-7/° c), a softening point of less than or equal to 660 ℃, and a resistance to hydrolysis according to ISO720:1985 of grade HGA1 or grade HGA 2. Some of these glasses within composition space a may have a liquidus viscosity greater than 90kP so that the glasses are compatible with sheet forming processes (e.g., fusion draw processes, slot draw processes, etc.).

In an embodiment of the glass composition constituting space A, SiO₂Is the largest constituent component of the composition and thus the main constituent of the resulting glass network. That is, SiO₂Is the primary network former. SiO 2₂The chemical durability of the glass is enhanced, and in particular, the resistance of the glass composition to decomposition in acid and the resistance of the glass composition to decomposition in water are enhanced. Therefore, high SiO is generally desired₂And (4) concentration. However, if SiO₂Too high content of (b), the formability of the glass may be reduced because of higher SiO₂The concentration increases the difficulty of melting, softening and molding the glass composition, which in turn negatively affects the formability of the glass. In embodiments of the glass compositions described herein, lower SiO may be included in the glass composition₂In an amount to maintain formability of the glass, and additional constituent components may be added to the glass to compensate for the lower SiO content in the glass₂The amount resulting in a decrease in chemical durability.

In an embodiment, the glass composition constituting space A comprises SiO₂The amount of (c) can be greater than or equal to 48 mole%. SiO 2₂The amount may be less than or equal to 61 mole percent so that the glass may be readily melted and shaped. Thus, in embodiments of the glass composition comprising space A, the glass composition comprises SiO₂The amount of (b) may be greater than or equal to 48 mol% and less than or equal to 61 mol%. In embodiments, the SiO in the glass composition₂The lower limit of the amount of (B) may be: greater than or equal to 48 mole%, greater than or equal to 49 mole%, greater than or equal to 50 mole%, greater than or equal to 51 mole%, greater than or equal to 52 mole%, greater than or equal to 53 mole%, or even greater than or equal to 54 mole%. In embodiments, the SiO in the glass composition₂The upper limit of the amount of (b) may be: less than or equal to 61 mole%, less than or equal to 60 mole%, less than or equal to 59 mole%, less than or equal to 58 mole%, less than or equal to 57 mole%, less than or equal to 56 mole%, less than or equal to 55 mole%, less than or equal to 54 mole%, less than or equal to 53 mole%, or even less than or equal to 52 mole%. It is understood that SiO in the glass composition₂The amount may be in the SiO range described herein₂Any one of the lower limits of (1) and SiO₂Within a range formed by any of the upper limits of (1).

For example, in embodiments, the glass composition constituting space a may include greater than or equal to 48 mol% and less than or equal to 61 mol% SiO₂But is not limited thereto. In embodiments, the glass composition may include greater than or equal to 49 mol% and less than or equal to 61 mol% SiO₂. In embodiments, the glass composition may include greater than or equal to 50 mol% and less than or equal to 61 mol% SiO₂. In embodiments, the glass composition may include greater than or equal to 51 mol% and less than or equal to 61 mol% SiO₂. In embodiments, the glass composition may include greater than or equal to 52 mol% and less than or equal to 61 mol% SiO₂. In embodiments, the glass composition may include greater than or equal to 52 mol% and less than or equal to 61 mol% SiO₂. In embodiments, the glass composition may comprise greater than or equal to 53 mol% and less than or equal to 60 mol% SiO₂. In embodiments, the glass composition may include greater than or equal to 54 mol% and less than or equal to 59 mol% SiO₂. In embodiments, the glass composition may comprise greater than or equal to 48 mol% and less than or equal to 55 mol% SiO₂. In embodiments, the glass composition may comprise greater than or equal to 49 mol% and less than or equal toEqual to 54 mol% SiO₂. In embodiments, the glass composition may include greater than or equal to 49 mol% and less than or equal to 53 mol% SiO₂. In embodiments, the glass composition may include greater than or equal to 49 mol% and less than or equal to 52 mol% SiO₂。

The glass composition constituting the space A may optionally contain Al₂O₃。Al₂O₃Can simultaneously play the roles of a network forming agent and a modifying agent. When contained, Al₂O₃Binding with the alkali oxides in the glass network increases the viscosity of the glass. Al may also be added to the glass composition₂O₃To reduce the amount of B added to the glass composition₂O₃The resulting phase separation. However, Al is added to the glass composition₂O₃It may also increase the softening point and lower the liquidus temperature of the glass, which may negatively affect the formability of the glass composition. Furthermore, if Al is present in the glass composition₂O₃Too high an amount reduces the resistance of the glass composition to acid attack.

In embodiments, the glass composition making up space A may be substantially free of Al₂O₃. In other embodiments, the glass composition making up space A includes Al₂O₃The amount of (c) may be greater than 0 mol% and less than or equal to 1 mol%. In these embodiments, the Al in the glass composition₂O₃The amount may be more than 0.1 mol% to increase the viscosity of the glass and reduce phase separation. Al (Al)₂O₃The amount may be less than or equal to 1 mole percent so as not to render the glass composition less resistant to acid attack and not to adversely affect the softening point and liquidus temperature. Therefore, in the presence of Al₂O₃In the embodiment of the glass composition constituting space A, the glass composition contains Al₂O₃The amount of (b) is generally greater than or equal to 0.1 mol% and less than or equal to 1 mol%. In an embodiment, Al in the glass composition₂O₃The lower limit of the amount of (c) may be: greater than or equal to 0.1 mol%, greater than or equal toEqual to 0.2 mole%, greater than or equal to 0.3 mole%, greater than or equal to 0.4 mole%, or even greater than or equal to 0.5 mole%. In an embodiment, Al in the glass composition₂O₃The upper limit of the amount of (b) may be: less than or equal to 1.0 mole%, less than or equal to 0.9 mole%, less than or equal to 0.8 mole%, or even less than or equal to 0.7 mole%. It is understood that Al in the glass composition₂O₃The amount of (A) can be Al as described herein₂O₃Any one of the lower limits of (1) and Al₂O₃Within a range formed by any of the upper limits of (1).

For example, the glass composition constituting the space A contains Al₂O₃The amount of (b) may be greater than or equal to 0.1 mol% and less than or equal to 1.0 mol%, but is not limited thereto. In an embodiment, Al is present in the glass composition₂O₃The amount of (b) is greater than or equal to 0.1 mol% and less than or equal to 0.9 mol%. In an embodiment, Al is present in the glass composition₂O₃The amount of (b) is greater than or equal to 0.1 mol% and less than or equal to 0.8 mol%. In an embodiment, Al is present in the glass composition₂O₃The amount of (b) is greater than or equal to 0.1 mol% and less than or equal to 0.7 mol%. In an embodiment, Al is present in the glass composition₂O₃The amount of (b) is greater than or equal to 0.2 mol% and less than or equal to 1.0 mol%. In an embodiment, Al is present in the glass composition₂O₃The amount of (b) is greater than or equal to 0.3 mol% and less than or equal to 1.0 mol%. In an embodiment, Al is present in the glass composition₂O₃The amount of (b) is greater than or equal to 0.4 mol% and less than or equal to 1.0 mol%.

Boron oxide (B)₂O₃) Is a glass former that may be added to the glass composition of composition space a to reduce the viscosity of the glass at a given temperature, thereby improving the formability of the glass. In other words, B is added to the glass₂O₃The strain, annealing, softening and molding temperatures of the glass composition are reduced, thereby improving the formability of the glass. Thus, addition of B may be employed₂O₃To compensate for the higher SiO₂A decrease in formability of the glass composition in an amount. However, it was found that if B is present in the glass composition₂O₃Too high, the glass may have a reduced resistance to decomposition in both acid and water. Thus, in embodiments, B is added to the glass composition₂O₃Is limited so as to preserve the chemical durability of the glass composition.

In an embodiment, the glass composition constituting space A comprises B₂O₃Is greater than or equal to 7 mol%, thereby enhancing the formability of the glass composition. B is₂O₃Is less than or equal to 20 mole percent so as not to reduce the resistance of the glass composition to decomposition in acid and water. Thus, in embodiments, the glass composition comprising space A comprises B₂O₃The amount of (b) is generally greater than or equal to 7 mol% and less than or equal to 20 mol%. In an embodiment, B is in the glass composition₂O₃The lower limit of the amount of (c) may be: greater than or equal to 7 mole%, greater than or equal to 8 mole%, greater than or equal to 9 mole%, greater than or equal to 10 mole%, greater than or equal to 11 mole%, greater than or equal to 12 mole%, greater than or equal to 13 mole%, greater than or equal to 14 mole%, or even greater than or equal to 15 mole%. In an embodiment, B in the glass composition₂O₃The upper limit of the amount of (b) may be: less than or equal to 20 mole%, less than or equal to 19 mole%, less than or equal to 18 mole%, less than or equal to 17 mole%, less than or equal to 16 mole%, or even less than or equal to 15 mole%. It is understood that B in the glass composition₂O₃The amount of (A) may be as described by B herein₂O₃Any one of the lower limits of (1) and B₂O₃Within a range formed by any of the upper limits of (1).

For example, the glass composition constituting the space A contains B₂O₃The amount of (c) may be greater than or equal to 7 mol% and less than or equal to 20 mol%, but is not limited thereto. In an embodiment, B in the glass composition₂O₃In an amount of 10 mol% or more and less than or equal to20 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 11 mol% and less than or equal to 20 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 12 mol% and less than or equal to 20 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 12 mol% and less than or equal to 19 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 12 mol% and less than or equal to 19 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 12 mol% and less than or equal to 18 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 12 mol% and less than or equal to 17 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 12 mol% and less than or equal to 16 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 12 mol% and less than or equal to 15 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 13 mol% and less than or equal to 17 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 14 mol% and less than or equal to 17 mol%.

The glass composition constituting space a further contains one or more alkali oxides. In this context, the sum of all basic oxides (in mol%) is expressed as R₂And O. In particular, R₂O is Na present in the glass composition₂O (mol%), K₂O (mol%) and Li₂Sum of O (mol%). Like B₂O₃The alkali oxide helps to increase the softening point and molding temperature of the glass composition, thereby compensating for the higher SiO in the glass composition₂The amount results in an increase in the softening point and molding temperature of the glass composition. It is also possible to include a combination of basic oxides (e.g., two or more basic oxides) in the glass compositionFurther intensifies the softening point and the lowering of the molding temperature, and is called a phenomenon of "mixed alkaline effect". However, it was found that if the amount of basic oxide is too high, the average coefficient of thermal expansion of the glass composition increases to greater than 100x10^-7This may be undesirable per degree centigrade.

In embodiments, the amount of basic oxide (i.e., R) in the glass composition making up space A₂The amount of O) may be greater than or equal to 9 mol% and less than or equal to 16 mol%. In an embodiment, R in the glass composition₂The lower limit of the amount of O may be: greater than or equal to 9 mole%, greater than or equal to 9.5 mole%, greater than or equal to 10 mole%, greater than or equal to 10.5 mole%, greater than or equal to 11 mole%, greater than or equal to 11.5 mole%, greater than or equal to 12 mole%, greater than or equal to 12.5 mole%, or even greater than or equal to 13 mole%. In an embodiment, R in the glass composition₂The upper limit of the amount of O may be: less than or equal to 16.5 mole%, less than or equal to 16 mole%, less than or equal to 15.5 mole%, less than or equal to 15 mole%, less than or equal to 14.5 mole%, or even less than or equal to 14 mole%. It is understood that R in the glass composition₂The amount of O can be in the range of R as described herein₂Any of the lower limits of O and R₂Any of the upper limits of O.

For example, the glass composition constituting space A contains R₂The amount of O may be greater than or equal to 9 mol% and less than or equal to 16 mol%, but is not limited thereto. In an embodiment, R in the glass composition₂The amount of O is greater than or equal to 9 mol% and less than or equal to 15 mol%. In an embodiment, R in the glass composition₂The amount of O is greater than or equal to 9 mol% and less than or equal to 14 mol%. In an embodiment, R in the glass composition₂The amount of O is 9 mol% or more and 13 mol% or less. In an embodiment, R in the glass composition₂The amount of O is 10 mol% or more and 16 mol% or less. In an embodiment, R in the glass composition₂The amount of O is 10 mol% or more and less15 mol% or more. In an embodiment, R in the glass composition₂The amount of O is 10 mol% or more and 14 mol% or less. In an embodiment, R in the glass composition₂The amount of O is 10 mol% or more and 13 mol% or less. In an embodiment, R in the glass composition₂The amount of O is greater than or equal to 11 mol% and less than or equal to 16 mol%. In an embodiment, R in the glass composition₂The amount of O is not less than 11 mol% and not more than 15 mol%. In an embodiment, R in the glass composition₂The amount of O is not less than 11 mol% and not more than 14 mol%. In an embodiment, R in the glass composition₂The amount of O is not less than 11 mol% and not more than 13 mol%.

The basic oxide Li was found₂O has a significant effect on lowering the melting point, softening point and molding temperature of the glass composition, and thus, Li₂O is compensated for by the higher concentration of SiO in the glass composition₂The resulting reduction in formability of the glass composition is effective. However, as noted herein, lithium ions in glass are highly mobile and thus tend to migrate out of the glass. When the glass is coated (e.g., a metal layer, etc.), or when the glass is in contact with a liquid, lithium ions leached from the glass may contaminate or degrade the coating and/or the liquid. Thus, in the embodiments described herein, the glass composition is substantially free of Li₂O (i.e., R)₂O is substantially free of Li₂O)。

In an embodiment of the glass composition constituting the space A, the alkali oxide (R)₂O) comprises Na₂And O. As noted herein, an alkaline oxide (e.g., Na) is added₂O) lowers the softening point and molding temperature of the glass composition, thereby compensating for the higher SiO in the glass composition₂The amount results in an increase in the softening point and molding temperature of the glass composition. However, if Na₂If the amount of O is too high, the thermal expansion coefficient of the glass composition becomes too high, which is not desirable.

In the presence of Na₂In the embodiment of the glass composition of the composition space A of O, Na is present in the glass composition₂The amount of O is greater than or equal to 9 mol% to improve the formability of the glass composition. Na in glass composition₂The amount of O may be less than or equal to 15 mol% so that the thermal expansion coefficient is not undesirably high. Thus, Na in the glass composition₂The amount of O is greater than or equal to 9 mol% and less than or equal to 15 mol%. In an embodiment, Na in the glass composition₂The lower limit of the amount of O may be: greater than or equal to 9 mole%, greater than or equal to 9.5 mole%, greater than or equal to 10 mole%, greater than or equal to 10.5 mole%, or even greater than or equal to 11 mole%. In an embodiment, Na in the glass composition₂The upper limit of the amount of O may be: less than or equal to 15 mole%, less than or equal to 14.5 mole%, less than or equal to 14 mole%, less than or equal to 13.5 mole%, less than or equal to 13 mole%, less than or equal to 12.5 mole%, or even less than or equal to 12 mole%. It is understood that Na in the glass composition₂The amount of O can be Na as described herein₂Any of the lower limits of O and Na₂Any of the upper limits of O.

For example, the glass composition constituting the space A contains Na₂The amount of O may be greater than or equal to 9 mol% and less than or equal to 15 mol%, but is not limited thereto. In an embodiment, Na in the glass composition₂The amount of O is greater than or equal to 9 mol% and less than or equal to 14 mol%. In an embodiment, Na in the glass composition₂The amount of O is 9 mol% or more and 13 mol% or less. In an embodiment, Na in the glass composition₂The amount of O is greater than or equal to 9 mol% and less than or equal to 12 mol%. In an embodiment, Na in the glass composition₂The amount of O is 10 mol% or more and 15 mol% or less. In an embodiment, Na in the glass composition₂The amount of O is 10 mol% or more and 14 mol% or less. In an embodiment, Na in the glass composition₂The amount of O is greater than or equal to 10 molesAnd 13 mol% or less. In an embodiment, Na in the glass composition₂The amount of O is 10 mol% or more and 12 mol% or less.

The alkali oxides in the glass composition constituting space A may optionally include K₂And O. Similar to Na₂O, addition of K₂O lowers the softening point and molding temperature of the glass composition, thereby compensating for the higher SiO in the glass composition₂The amount results in an increase in the softening point and molding temperature of the glass composition. However, if K₂If the amount of O is too high, the thermal expansion coefficient of the glass composition becomes too high, which is not desirable. Therefore, it is desirable to limit K in the glass composition₂The amount of O present.

In embodiments, the glass composition comprising space A may be substantially free of K₂And O. In the presence of a basic oxide comprising K₂In O embodiment, K present in the glass composition₂The amount of O may be greater than 0 mole%, for example: greater than or equal to 0.5 or even 1 mol%, thereby contributing to improved formability of the glass composition. K₂The amount of O is 5 mol% or less so that the thermal expansion coefficient is not undesirably high. Thus, K in the glass composition₂The amount of O may be greater than or equal to 1 mol% and less than or equal to 5 mol%. In an embodiment, K is present in the glass composition₂The lower limit of the amount of O may be: greater than or equal to 0.5 mole%, greater than or equal to 1 mole%, greater than or equal to 1.25 mole%, greater than or equal to 1.5 mole%, greater than or equal to 1.75 mole%, greater than or equal to 2.0 mole%, greater than or equal to 2.25 mole%, greater than or equal to 2.5 mole%, greater than or equal to 2.75 mole%, or even greater than or equal to 3.0 mole%. In an embodiment, K in the glass composition₂The upper limit of the amount of O may be: less than or equal to 5 mole%, less than or equal to 4.75 mole%, less than or equal to 4.5 mole%, less than or equal to 4.25 mole%, less than or equal to 4 mole%, less than or equal to 3.75 mole%, less than or equal to 3.5 mole%, less than or equal to 3.25 mole%, or even less than or equal to 3 mole%. It should be understood thatIn glass composition K₂The amount of O can be in K as described herein₂K and any one of the lower limits of O₂Any of the upper limits of O.

For example, the glass composition constituting space A contains K₂The amount of O may be greater than or equal to 1 mol% to less than or equal to 5 mol%, but is not limited thereto. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 1 mol% and less than or equal to 4.75 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 1 mol% and less than or equal to 4.5 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 1 mol% and less than or equal to 4.25 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 1 mol% and less than or equal to 4 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 1 mol% and less than or equal to 3.75 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 1 mol% and less than or equal to 3.5 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 1 mol% and less than or equal to 3.25 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 1 mol% and less than or equal to 3.0 mol%.

Embodiments of the glass composition making up space a also include ZnO as a primary modifier of the glass composition. The addition of ZnO to the glass composition lowers the softening point and molding temperature of the glass composition, thereby compensating for the higher SiO in the glass composition₂The amount results in an increase in the softening point and molding temperature of the glass composition. It is noteworthy that the addition of ZnO does not increase the average coefficient of thermal expansion of the glass composition as much as some other modifiers (e.g., the basic and/or alkaline earth oxides CaO, BaO, and SrO) over the temperature range of 20 ℃ to 300 ℃. Thus, the benefits of adding ZnO to lower the softening point and molding temperature can be maximized without significantly increasing the average coefficient of thermal expansion of the glass composition. For, ZnO pairThe effect on the glass composition is similar to MgO (e.g., it lowers the softening point and molding temperature of the glass composition without significantly increasing the average coefficient of thermal expansion). However, the addition of ZnO to achieve these properties is advantageous over the addition of MgO because ZnO has a more pronounced effect on the softening point and ZnO promotes nucleation and crystallization in the glass less highly than MgO.

In an embodiment of the glass composition constituting space a, the glass composition includes ZnO in an amount of 8 mol% or more, thereby enhancing the formability of the glass composition. The amount of ZnO is less than or equal to 21 mol% so as not to reduce the liquidus viscosity of the glass composition. Thus, in the embodiments described herein, the glass composition typically includes ZnO in an amount greater than or equal to 8 mol% and less than or equal to 21 mol%. In embodiments, the lower limit of the amount of ZnO in the glass composition may be: greater than or equal to 8 mole%, greater than or equal to 9 mole%, greater than or equal to 10 mole%, greater than or equal to 11 mole%, greater than or equal to 12 mole%, greater than or equal to 13 mole%, greater than or equal to 14 mole%, greater than or equal to 15 mole%, greater than or equal to 16 mole%, greater than or equal to 17 mole%, greater than or equal to 18 mole%, or even greater than or equal to 19 mole%. In embodiments, the upper limit of the amount of ZnO in the glass composition may be: less than or equal to 21 mole%, less than or equal to 20 mole%, less than or equal to 19 mole%, less than or equal to 18 mole%, less than or equal to 17 mole%, less than or equal to 16 mole%, or even less than or equal to 15 mole%. It is to be understood that the amount of ZnO in the glass composition may be within a range formed by any of the lower limits of ZnO and any of the upper limits of ZnO described herein.

For example, the glass composition constituting the space a may include ZnO in an amount of greater than or equal to 7 mol% and less than or equal to 21 mol%, but is not limited thereto. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 13 mol% and less than or equal to 20 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 13 mol% and less than or equal to 20 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 14 mol% and less than or equal to 20 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 15 mol% and less than or equal to 20 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 8 mol% and less than or equal to 19 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 8 mol% and less than or equal to 18 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 8 mol% and less than or equal to 17 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 8 mol% and less than or equal to 16 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 8 mol% and less than or equal to 15 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 9 mol% and less than or equal to 19 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 9 mol% and less than or equal to 18 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 9 mol% and less than or equal to 17 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 9 mol% and less than or equal to 16 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 9 mol% and less than or equal to 15 mol%.

In embodiments of the glass compositions making up space A described herein, the ratio of the amount of ZnO to the total amount of basic oxide in the glass composition (i.e., ZnO (mole%): R₂O (% by mole)) greater than or equal to 0.75 and less than or equal to 2.0, thereby maintaining a low liquidus temperature, softening point and CTE. Glass compositions having a ZnO-RO ratio falling within this range generally have a lower softening temperature and a lower average coefficient of thermal expansion over the temperature range of 20 ℃ to 300 ℃. In an embodiment, ZnO (mole%) R₂The ratio of O (mol%) is 1.0 or more and 2.0 or less. When the ratio exceeds 2, the liquidus temperature may increase, which decreases the liquidus viscosity and glass stability, and thus may no longer be suitable for a down-draw or fusion forming process.

The glass composition constituting space a further contains one or more alkaline earth oxides. The sum of the alkaline earth oxides (in mole%) is expressed herein as RO. Specifically, RO is the sum of MgO (mol%), CaO (mol%), BaO (mol%), and SrO (mol%) present in the glass composition. Alkaline earth oxides may be incorporated into the glass to enhance various properties. For example, the addition of certain alkaline earth oxides can help lower the softening point and molding temperature of the glass composition, thereby compensating for the higher SiO in the glass composition₂The amount results in an increase in the softening point and molding temperature of the glass composition. The addition of certain alkaline earth oxides may also help reduce the tendency of the glass to crystallize. Generally, the addition of alkaline earth oxides does not increase the average coefficient of thermal expansion of the glass composition as much as some other modifying agent (e.g., a basic oxide) over the temperature range of 20 ℃ to 300 ℃. In addition, it was found that smaller alkaline earth oxides do not increase the average coefficient of thermal expansion of the glass composition as much as larger alkaline earth oxides over the temperature range of 20 ℃ to 300 ℃. For example, the increase in the average coefficient of thermal expansion of MgO for the glass composition is less than the increase in the average coefficient of thermal expansion of BaO for the glass composition.

In embodiments of the glass composition making up space a, the amount of alkaline earth oxide in the glass composition (i.e., the amount of RO) is less than half the amount of ZnO in the glass composition (i.e., RO (mole%) <0.5x ZnO (mole%)), so that the glass composition is ZnO-rich relative to alkaline earth oxide, maintaining a low molding temperature and CTE.

In embodiments, the glass composition making up space a may be substantially free of alkaline earth oxides. In embodiments of the glass composition comprising alkaline earth oxide composition space a, the alkaline earth oxide may be present in an amount greater than 0 mole percent, for example: 0.5 mol% or more and 10 mol% or less. In embodiments, the lower limit of the amount of alkaline earth oxide in the glass composition may be: greater than or equal to 0.5 mole%, greater than or equal to 0.75 mole%, greater than or equal to 1.0 mole%, greater than or equal to 1.5 mole%, greater than or equal to 1.75 mole%, greater than or equal to 2.0 mole%, greater than or equal to 2.25 mole%, greater than or equal to 2.5 mole%, greater than or equal to 2.75 mole%, greater than or equal to 3.0 mole%, greater than or equal to 3.25 mole%, greater than or equal to 3.5 mole%, greater than or equal to 3.75 mole%, or even greater than or equal to 4.0 mole%. In embodiments, the upper limit of the amount of alkaline earth oxide in the glass composition may be: less than or equal to 10.0 mole%, less than or equal to 9.5 mole%, less than or equal to 9.0 mole%, less than or equal to 8.5 mole%, less than or equal to 8.0 mole%, less than or equal to 7.5 mole%, or even less than or equal to 7.0 mole%, less than or equal to 6.5 mole%, less than or equal to 6.0 mole%, less than or equal to 5.5 mole%, less than or equal to 5.0 mole%, less than or equal to 4.5 mole%, or even less than or equal to 4.0 mole%. It is to be understood that the amount of alkaline earth oxide in the glass composition can be within a range formed by any of the lower limits of alkaline earth oxides and any of the upper limits of alkaline earth oxides described herein.

For example, the glass composition constituting the space a may contain the alkaline earth oxide in an amount of greater than or equal to 0.5 mol% and less than or equal to 10.0 mol%, but is not limited thereto. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 9.0 mol% of the alkaline earth oxide. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 8.0 mol% of the alkaline earth oxide. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 7.0 mol% of the alkaline earth oxide. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 6.0 mol% of the alkaline earth oxide. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 5.0 mol% of the alkaline earth oxide. In embodiments, the glass composition may include greater than or equal to 0.75 mol% and less than or equal to 5.0 mol% of the alkaline earth oxide. In embodiments, the glass composition may include greater than or equal to 1.0 mol% and less than or equal to 5.0 mol% of the alkaline earth oxide. In embodiments, the glass composition may include greater than or equal to 1.5 mol% and less than or equal to 5.0 mol% of the alkaline earth oxide. In embodiments, the glass composition may include greater than or equal to 1.75 mol% and less than or equal to 5.0 mol% of the alkaline earth oxide. In embodiments, the glass composition may include greater than or equal to 2.0 mol% and less than or equal to 5.0 mol% of the alkaline earth oxide. In embodiments, the glass composition may include greater than or equal to 2.5 mol% and less than or equal to 5.0 mol% of the alkaline earth oxide.

In embodiments of the glass compositions of compositional space a described herein, the alkaline earth oxide in the glass composition may optionally include MgO. In addition to improving the formability and meltability of the glass composition, MgO may also increase the viscosity of the glass and reduce the tendency of the glass to crystallize. Too much MgO tends to cause crystallization in the glass, increases liquidus viscosity and decreases formability.

In embodiments, the glass composition constituting space a may be substantially free of MgO. In embodiments where the glass composition comprises MgO, the amount of MgO may be greater than 0 mol%, for example: 0.5 mol% or more and 5 mol% or less. In embodiments, the lower limit of the amount of MgO in the glass composition may be: greater than 0 mole%, greater than or equal to 0.5 mole%, greater than or equal to 0.75 mole%, greater than or equal to 1.0 mole%, greater than or equal to 1.25 mole%, greater than or equal to 1.5 mole%, greater than or equal to 1.75 mole%, or even greater than or equal to 2 mole%. In embodiments, the upper limit of the amount of MgO in the glass composition may be: less than or equal to 2.5 mole%, less than or equal to 2.25 mole%, or even less than or equal to 2.0 mole%. It is to be understood that the amount of MgO in the glass composition can be within a range formed by any of the lower limits of MgO and any of the upper limits of MgO described herein.

For example, the glass composition constituting the space a may include MgO in an amount of greater than or equal to 0.5 mol% and less than or equal to 5 mol%, but is not limited thereto. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 4.5 mol% MgO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 4.0 mol% MgO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 3.5 mol% MgO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 3.0 mol% MgO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 2.5 mol% MgO.

In the embodiments described herein, the alkaline earth oxide in the glass composition constituting space a may optionally include SrO. In addition to improving the formability and meltability of the glass composition, SrO may also reduce the tendency of the glass to crystallize. Too much SrO changes the liquidus viscosity and may increase the CTE of the glass.

In embodiments, the glass composition making up space a may be substantially free of SrO. In embodiments where the glass composition comprises SrO, the amount of SrO may be greater than 0 mol%, for example: 0.5 mol% or more and 5 mol% or less. In embodiments, the lower limit of the amount of SrO in the glass composition may be: greater than 0 mole%, greater than or equal to 0.5 mole%, greater than or equal to 0.75 mole%, greater than or equal to 1.0 mole%, greater than or equal to 1.25 mole%, greater than or equal to 1.5 mole%, greater than or equal to 1.75 mole%, or even greater than or equal to 2 mole%. In embodiments, the upper limit of the amount of SrO in the glass composition may be: less than or equal to 2.5 mole%, less than or equal to 2.25 mole%, or even less than or equal to 2.0 mole%. It is to be understood that the amount of SrO in the glass composition can be within a range formed by any of the lower limits of SrO and any of the upper limits of SrO described herein.

For example, the glass composition constituting the space a may contain SrO in an amount of 0.5 mol% or more and 5 mol% or less, but is not limited thereto. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 4.5 mol% SrO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 4.0 mol% SrO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 3.5 mol% SrO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 3.0 mol% SrO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 2.5 mol% SrO.

In an embodiment, the total amount of SrO and MgO in the glass composition that makes up space a (i.e., SrO (mol%) + MgO (mol%)) is greater than or equal to 0.5 mol% and less than or equal to 10 mol%. In an embodiment, the total amount of SrO and MgO in the glass composition is greater than or equal to 0.5 mol% and less than or equal to 9 mol%. In an embodiment, the total amount of SrO and MgO in the glass composition is greater than or equal to 0.5 mol% and less than or equal to 8 mol%. In an embodiment, the total amount of SrO and MgO in the glass composition is greater than or equal to 0.5 mol% and less than or equal to 7 mol%. In an embodiment, the total amount of SrO and MgO in the glass composition is greater than or equal to 0.5 mol% and less than or equal to 6 mol%. In an embodiment, the total amount of SrO and MgO in the glass composition is greater than or equal to 0.5 mol% and less than or equal to 5 mol%. In an embodiment, the total amount of SrO and MgO in the glass composition is greater than or equal to 0.5 mol% and less than or equal to 4 mol%. In an embodiment, the total amount of SrO and MgO in the glass composition is greater than or equal to 0.5 mol% and less than or equal to 3 mol%. In an embodiment, the total amount of SrO and MgO in the glass composition is greater than or equal to 0.5 mol% and less than or equal to 2 mol%.

In embodiments of the glass compositions of compositional space a described herein, the alkaline earth oxide in the glass composition may optionally include BaO. In addition to improving the formability and meltability of the glass composition, the addition of small amounts of BaO can also help to lower the liquidus temperature. Too high a BaO concentration tends to undesirably increase the CTE and density of the glass. The increase in density negatively affects formability.

In embodiments, the glass composition constituting space a may be substantially free of BaO. In embodiments where the glass composition comprises BaO, the amount of BaO may be greater than 0 mole percent, for example: 0.5 mol% or more and 5 mol% or less. In embodiments, the lower limit of the amount of BaO in the glass composition may be: greater than 0 mole%, greater than or equal to 0.5 mole%, greater than or equal to 0.75 mole%, greater than or equal to 1.0 mole%, greater than or equal to 1.25 mole%, greater than or equal to 1.5 mole%, greater than or equal to 1.75 mole%, or even greater than or equal to 2 mole%. In embodiments, the upper limit of the amount of BaO in the glass composition may be: less than or equal to 2.5 mole%, less than or equal to 2.25 mole%, or even less than or equal to 2.0 mole%. It is to be understood that the amount of BaO in the glass composition can be within a range formed by any of the lower limits of BaO and any of the upper limits of BaO described herein.

For example, the glass composition constituting the space a may include BaO in an amount of greater than or equal to 0.5 mol% and less than or equal to 5 mol%, but is not limited thereto. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 4.5 mol% BaO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 4.0 mol% BaO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 3.5 mol% BaO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 3.0 mol% BaO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 2.5 mol% BaO.

In embodiments of the glass compositions of compositional space a described herein, the alkaline earth oxide in the glass composition may optionally include CaO. In addition to improving the formability and meltability of the glass composition, CaO, at small amounts, can also lower the liquidus temperature while improving chemical durability and lowering CTE. If the content of CaO is too high (or if the content of MgO + CaO is too high), diopside crystals are formed and the liquidus viscosity is deteriorated.

In embodiments, the glass composition making up space a may be substantially free of CaO. In embodiments where the glass composition includes CaO, the amount of CaO may be greater than 0 mol%, for example: 0.5 mol% or more and 5 mol% or less. In embodiments, the lower limit of the amount of CaO in the glass composition may be: greater than 0 mole%, greater than or equal to 0.5 mole%, greater than or equal to 0.75 mole%, greater than or equal to 1.0 mole%, greater than or equal to 1.25 mole%, greater than or equal to 1.5 mole%, greater than or equal to 1.75 mole%, or even greater than or equal to 2 mole%. In embodiments, the upper limit of the amount of CaO in the glass composition may be: less than or equal to 2.5 mole%, less than or equal to 2.25 mole%, or even less than or equal to 2.0 mole%. It is to be understood that the amount of CaO in the glass composition can be within a range formed by any of the lower limits for CaO and any of the upper limits for CaO described herein.

For example, the glass composition constituting the space a may contain CaO in an amount of greater than or equal to 0.5 mol% and less than or equal to 5 mol%, but is not limited thereto. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 4.5 mol% CaO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 4.0 mol% CaO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 3.5 mol% CaO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 3.0 mol% CaO. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 2.5 mol% CaO.

The glass composition making up space a may also include one or more additional metal oxides to further improve the chemical durability of the glass composition. In particular, the addition of TiO was found₂And ZrO₂Can further increase the chemical durability of the glass composition, resulting in a glass composition having good chemical durability, particularly with respect to the chemical durability of the glass in alkaline solutions. And alsoAddition of TiO was found₂And ZrO₂Advantageously reduces the average coefficient of thermal expansion of the glass composition.

Without wishing to be bound by theory, it is believed that the addition of TiO₂And ZrO₂By strengthening at least one of Al₂O₃The functionality in the glass composition thus improves the properties of the glass. For chemical durability, it is believed that the addition of Al to the glass composition₂O₃The amount of non-bridging oxygen in the glass composition is reduced, which in turn improves the chemical durability of the glass. However, it was found that if Al is present in the glass composition₂O₃Too high an amount reduces the resistance of the glass composition to acid attack. It has now been found that, in addition to Al₂O₃Containing TiO in addition₂And ZrO₂Further reduces the amount of non-bridging oxygen in the glass composition, which in turn further improves the chemical durability of the glass over the addition of Al alone₂O₃What can be achieved.

In embodiments, the glass composition making up space a may optionally comprise TiO₂. It was found that TiO was added to the glass composition₂The resistance of the glass composition to hydrolysis is improved. Including TiO in glass compositions₂In an embodiment of (1), TiO present in the glass composition₂The lower limit of the amount of (c) may be: greater than or equal to 0.1 mole%, greater than or equal to 0.2 mole%, greater than or equal to 0.3 mole%, greater than or equal to 0.4 mole%, greater than or equal to 0.5 mole%, greater than or equal to 0.6 mole%, greater than or equal to 0.7 mole%, greater than or equal to 0.8 mole%, greater than or equal to 0.9 mole%, greater than or equal to 1.0 mole%, or even greater than or equal to 1.25 mole%. In embodiments, TiO in the glass composition₂The upper limit of the amount of (b) may be: less than or equal to 1.5 mole%, less than or equal to 1.25 mole%, or even less than or equal to 1.0 mole%. It is understood that TiO in the glass composition₂The amount may be in the range of TiO as described herein₂Any one of the lower limits of (1) and TiO₂Within a range formed by any of the upper limits of (1).

For example, the glass composition constituting space A contains TiO₂The amount of (b) may be greater than or equal to 0.1 mol% and less than or equal to 1.5 mol%, but is not limited thereto. In embodiments, the glass composition may include greater than or equal to 0.1 mol% and less than or equal to 1.0 mol% TiO₂. In embodiments, the glass composition may include greater than or equal to 0.1 mol% and less than or equal to 0.75 mol% TiO₂. In embodiments, the glass composition may include greater than or equal to 0.1 mol% and less than or equal to 0.5 mol% TiO₂. In embodiments, the glass composition may include greater than or equal to 0.25 mol% and less than or equal to 1.5 mol% TiO₂. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 1.5 mol% TiO₂. In embodiments, the glass composition may include greater than or equal to 0.75 mol% and less than or equal to 1.5 mol% TiO₂. In embodiments, the glass composition may include greater than or equal to 1.0 mol% and less than or equal to 1.5 mol% TiO₂. In embodiments, the glass composition may include greater than or equal to 1.0 mol% and less than or equal to 1.25 mol% TiO₂。

Addition of ZrO to the glass composition constituting space A₂The alkali resistance of the glass composition is improved. Containing ZrO in the glass composition₂In an embodiment of (1), ZrO present in the glass composition₂The lower limit of the amount of (c) may be: greater than or equal to 0.1 mole%, greater than or equal to 0.2 mole%, greater than or equal to 0.3 mole%, greater than or equal to 0.4 mole%, greater than or equal to 0.5 mole%, greater than or equal to 0.6 mole%, greater than or equal to 0.7 mole%, greater than or equal to 0.8 mole%, greater than or equal to 0.9 mole%, greater than or equal to 1.0 mole%, or even greater than or equal to 1.25 mole%. In an embodiment, ZrO in the glass composition₂The upper limit of the amount of (b) may be: less than or equal to 1.5 mole%, less than or equal to 1.25 mole%, or even less than or equal to 1.0 mole%. It is understood that ZrO in the glass composition₂The amount of (b) may be in the range of ZrO described herein₂Any one of the lower limits of (1) and ZrO₂Within a range formed by any of the upper limits of (1).

For example, the glass composition constituting the space A contains ZrO₂The amount of (b) may be greater than or equal to 0.1 mol% and less than or equal to 1.5 mol%, but is not limited thereto. In embodiments, the glass composition may include greater than or equal to 0.1 mol% and less than or equal to 1.0 mol% ZrO₂. In embodiments, the glass composition may include greater than or equal to 0.1 mol% and less than or equal to 0.75 mol% ZrO₂. In embodiments, the glass composition may include greater than or equal to 0.1 mol% and less than or equal to 0.5 mol% ZrO₂. In embodiments, the glass composition may include greater than or equal to 0.25 mol% and less than or equal to 1.5 mol% ZrO₂. In embodiments, the glass composition may include greater than or equal to 0.5 mol% and less than or equal to 1.5 mol% ZrO₂. In embodiments, the glass composition may include greater than or equal to 0.75 mol% and less than or equal to 1.5 mol% ZrO₂. In embodiments, the glass composition may include greater than or equal to 1.0 mol% and less than or equal to 1.5 mol% ZrO₂. In embodiments, the glass composition may include greater than or equal to 1.0 mol% and less than or equal to 1.25 mol% ZrO₂。

Furthermore, as noted above, the glass composition making up space a is chemically durable and resistant to decomposition in acid, base and water as determined by the acid and base tests described herein and the ISO720 standard. The chemical durability of the glass composition makes the glass composition particularly suitable for applications where the glass is in contact with liquids, including but not limited to acidic liquids, alkaline liquids, and water-based liquids.

ISO720 standard measures the glass in pure CO-free₂Resistance to decomposition in water of (1). Briefly, the ISO720 standard protocol employs milled glass particles, which are placed in contact with pure CO-free glass particles₂Is contacted at 121 c and a pressure of 2 atmospheres. The solution was then colorimetrically titrated with dilute HCl to neutral pH. Then titrating to a neutral solutionThe required amount of HCl was converted to an equivalent amount of Na extracted from the glass₂O, and recorded as μ gNa₂A smaller value of O per weight of glass indicates better durability of the glass. The ISO720 standard is divided into separate types. Type HGA1 represents up to 62. mu.g of Na₂O extraction equivalent per gram of test glass; type HGA2 represents Na exceeding 62. mu.g and up to 527. mu.g₂O extraction equivalent per gram of test glass; and type HGA3 represents Na exceeding 527 μ g and up to 930 μ g₂O extraction equivalent per gram of test glass.

As described herein, the resistance of glass to decomposition in acid is determined by: a 2.54cm x5.08 inch x 1mm thick sample of the glass composition was immersed into a5 wt% aqueous solution of HCl (95 ℃, for 24 hours) (hereinafter referred to as the "acid test"). The weight of the sample was measured before and after immersion and the weight loss per unit area (i.e., (initial weight-final weight)/total surface area (cm) was determined²))。

As described herein, the resistance of the glass to decomposition in alkaline solutions was determined by: a 2.54cm x5.08 inch x 1mm thick sample of the glass composition was immersed into a5 wt% aqueous solution of NaOH (95 ℃, for 6 hours) (hereinafter referred to as the "alkali test"). The weight of the sample was measured before and after immersion and the weight loss per unit area (i.e., (initial weight-final weight)/total surface area (cm) was determined²))。

The glass composition constituting space a has a resistance to hydrolysis of ISO720 type HGA2 or type HGA 1. In embodiments, the glass compositions described herein have ISO720 type HGA1 resistance to hydrolysis. In some embodiments, the glass composition making up space a may have less than 10mg/cm after exposure to the acid test²Less than or equal to 1mg/cm²Or even less than or equal to 0.1mg/cm²The weight loss of (c). In some embodiments, the glass composition making up space a may have less than 10mg/cm after exposure to the alkali test²Less than or equal to 5mg/cm²Or even less than or equal to 2mg/cm²The weight loss of (c).

Compositions as described hereinEmbodiments of the glass composition of space a, the glass composition has greater than or equal to 75x10 over a temperature range of 20 ℃ to 300 ℃^-788x10 or less per DEG C^-7Average Coefficient of Thermal Expansion (CTE) at/° C. For example, in embodiments, the glass composition has greater than or equal to 77x10 over a temperature range of 20 ℃ to 300 ℃^-788x10 or less per DEG C^-7Average Coefficient of Thermal Expansion (CTE) at/° C. In an embodiment, the glass composition has greater than or equal to 78x10 over a temperature range of 20 ℃ to 300 ℃^-788x10 or less per DEG C^-7Average Coefficient of Thermal Expansion (CTE) at/° C. In embodiments, the glass composition has greater than or equal to 79x10 over a temperature range of 20 ℃ to 300 ℃^-788x10 or less per DEG C^-7Average Coefficient of Thermal Expansion (CTE) at/° C. In an embodiment, the glass composition has greater than or equal to 80x10 over a temperature range of 20 ℃ to 300 ℃^-788x10 or less per DEG C^-7Average Coefficient of Thermal Expansion (CTE) at/° C. These lower CTE values improve the ability of the glass to withstand thermal cycling or thermal stress conditions compared to glass compositions having higher CTEs.

As described herein, the glass composition has a lower softening point and molding temperature. This improves the ease of remoulding the glass composition from the stock material into its final form. These lower temperatures may also extend the useful life of the mold in contact with the glass, as the lower molding temperatures reduce oxidation of the metal parts of the mold and minimize chemical reactions between the mold and the glass composition.

In embodiments of the glass compositions making up space a described herein, the glass compositions have a softening point less than or equal to 660 ℃. In embodiments, the glass composition has a softening point less than or equal to 650 ℃ or even less than or equal to 640 ℃.

In embodiments of the glass compositions comprising space a described herein, the glass composition has a molding temperature less than or equal to 630 ℃. In embodiments, the glass composition has a molding temperature of less than or equal to 620 ℃, less than or equal to 610 ℃, less than or equal to 600 ℃, or even less than or equal to 590 ℃.

The glass composition making up space a may generally have a strain point greater than or equal to about 400 ℃ and less than or equal to about 550 ℃, or even greater than or equal to about 400 ℃ and less than or equal to about 500 ℃. The glass composition may also have an anneal point of greater than or equal to about 450 ℃ and less than or equal to about 600 ℃, or even greater than or equal to about 500 ℃ and less than or equal to about 550 ℃.

In some embodiments, the glass composition making up space a can have a liquidus viscosity greater than or equal to 90 kilopoise (kP) such that the glass is compatible with sheet forming processes (i.e., fusion draw processes, slot draw processes, and the like). In some other embodiments, the glass composition making up space a may have a liquidus viscosity of less than 90 kilopoise (kP).

Forming a space B: lithium-free low ZnO glass composition with fluorine

The glass composition in composition space B contains SiO₂、Al₂O₃Alkali oxide (R)₂O) and F₂This can provide the glass composition with: lower coefficient of thermal expansion (e.g., less than or equal to 92x10 over a temperature range of about 20 ℃ to about 300 ℃)^-7/° c), a softening point of less than or equal to 680 ℃, and a resistance to hydrolysis according to ISO720:1985 of grade HGA1 or grade HGA 2.

In an embodiment of the glass composition constituting space B, SiO₂Is the largest constituent component of the composition and thus the main constituent of the resulting glass network. That is, SiO₂Is the primary network former. SiO 2₂The chemical durability of the glass is enhanced, and in particular, the resistance of the glass composition to decomposition in acid and the resistance of the glass composition to decomposition in water are enhanced. Therefore, high SiO is generally desired₂And (4) concentration. However, if SiO₂Too high content of (b), the formability of the glass may be reduced because of higher SiO₂The concentration increases the difficulty of softening, molding and melting the glass, which in turn negatively affects the formability of the glass. In the embodiment of the glass composition constituting the space B, the higher SiO may be compensated for by adding other constituent components (e.g., fluorine, etc.) that improve the formability of the glass composition₂The amount results in the properties of the glass composition.

In an embodiment, the glass composition constituting space B contains SiO₂The amount may be greater than or equal to 66 mole percent to provide a chemically durable glass composition. SiO 2₂The amount may be less than or equal to 74 mole percent so that the glass composition may be readily melted and shaped with the addition of other glass modifiers. Thus, in the embodiments described herein, the glass composition comprises SiO₂The amount of (b) may be greater than or equal to 66 mol% and less than or equal to 74 mol%. In embodiments, the SiO in the glass composition₂The lower limit of the amount of (c) may be: greater than or equal to 66 mole%, greater than or equal to 67 mole%, greater than or equal to 68 mole%, greater than or equal to 69 mole%, greater than or equal to 70 mole%, or even greater than or equal to 71 mole%. In embodiments, the SiO in the glass composition₂The upper limit of the amount of (b) may be: less than or equal to 74 mole%, less than or equal to 73 mole%, less than or equal to 72 mole%, or even less than or equal to 71 mole%. It is understood that SiO in the glass composition₂The amount may be in the SiO range described herein₂Any one of the lower limits of (1) and SiO₂Within a range formed by any of the upper limits of (1).

For example, in embodiments, the glass composition constituting space B may include greater than or equal to 66 mol% and less than or equal to 74 mol% SiO₂But is not limited thereto. In embodiments, the glass composition may include greater than or equal to 67 mol% and less than or equal to 74 mol% SiO₂. In embodiments, the glass composition may include greater than or equal to 68 mol% and less than or equal to 74 mol% SiO₂. In embodiments, the glass composition may comprise greater than or equal to 69 mol% and less than or equal to 74 mol% SiO₂. In embodiments, the glass composition may comprise greater than or equal toEqual to 70 mol% and less than or equal to 74 mol% SiO₂. In embodiments, the glass composition may comprise greater than or equal to 70 mol% and less than or equal to 73 mol% SiO₂. In embodiments, the glass composition may include greater than or equal to 70 mol% and less than or equal to 72 mol% SiO₂。

The glass composition constituting the space B may further contain Al₂O₃。Al₂O₃Can simultaneously play the roles of a network forming agent and a modifying agent. Al (Al)₂O₃Binding with the alkali oxides in the glass network increases the viscosity of the glass. Al may also be added to the glass composition₂O₃To reduce the amount of B added to the glass composition₂O₃The resulting phase separation. However, Al is added to the glass composition₂O₃It may also increase the softening point and lower the liquidus temperature of the glass, which may negatively affect the formability of the glass composition. Furthermore, if Al is present in the glass composition₂O₃Too high an amount reduces the resistance of the glass composition to acid attack.

In embodiments, the glass composition may be substantially free of Al₂O₃. In other embodiments, the glass composition comprises Al₂O₃The amount of (c) may be greater than or equal to 3 mol% and less than or equal to 7 mol%. In these embodiments, the Al in the glass composition₂O₃The amount may be greater than 3 mole%. Al (Al)₂O₃The amount may be less than or equal to 7 mole percent so as not to reduce the resistance of the glass composition to acid attack. In an embodiment, Al in the glass composition₂O₃The lower limit of the amount of (c) may be: greater than or equal to 3 mole%, greater than or equal to 3.5 mole%, greater than or equal to 4.0 mole%, greater than or equal to 4.5 mole%, or even greater than or equal to 5.0 mole%. In an embodiment, Al in the glass composition₂O₃The upper limit of the amount of (b) may be: less than or equal to 7.0 mole%, less than or equal to 6.75 mole%, less than or equal to 6.5 mole%, or even less than or equal to 6.25 mole%.It is understood that Al in the glass composition₂O₃The amount of (A) can be Al as described herein₂O₃Any one of the lower limits of (1) and Al₂O₃Within a range formed by any of the upper limits of (1).

For example, the glass composition constituting the space B contains Al₂O₃The amount of (b) may be greater than or equal to 3 mol% and less than or equal to 7.0 mol%, but is not limited thereto. In an embodiment, Al is present in the glass composition₂O₃The amount of (b) is greater than or equal to 3.5 mol% and less than or equal to 7.0 mol%. In an embodiment, Al is present in the glass composition₂O₃The amount of (b) is greater than or equal to 4.0 mol% and less than or equal to 7.0 mol%. In an embodiment, Al is present in the glass composition₂O₃The amount of (b) is greater than or equal to 4.5 mol% and less than or equal to 7.5 mol%. In an embodiment, Al is present in the glass composition₂O₃The amount of (b) is greater than or equal to 5.0 mol% and less than or equal to 7.0 mol%. In an embodiment, Al is present in the glass composition₂O₃The amount of (b) is greater than or equal to 5.5 mol% and less than or equal to 7.0 mol%.

Boron oxide (B)₂O₃) Is a glass former that may be added to the glass composition of composition space B to reduce the viscosity of the glass at a given temperature, thereby improving the formability of the glass. In other words, B is added to the glass₂O₃The strain, annealing, softening and molding temperatures of the glass composition are reduced, thereby improving the formability of the glass. Thus, addition of B may be employed₂O₃To compensate for the higher SiO₂A decrease in formability of the glass composition in an amount. However, it was found that if B is present in the glass composition₂O₃Too high, the glass composition may have a reduced resistance to decomposition in both acid and water. Thus, in embodiments, B is added to the glass composition₂O₃Is limited so as to preserve the chemical durability of the glass composition.

In embodiments, the glass composition making up space B may be substantially free of B₂O₃. In embodiments, the glass composition making up space B may comprise greater than 0 mol% B₂O₃(e.g., greater than or equal to 0.1 mol% B₂O₃) Thereby enhancing the formability of the glass composition. B is₂O₃Is less than or equal to 6 mole percent so as not to reduce the resistance of the glass composition to decomposition in acid and water. In a glass composition containing B₂O₃In an embodiment of (A), the glass composition comprises B₂O₃The amount of (b) is generally greater than or equal to 0.1 mol% and less than or equal to 6 mol%. In an embodiment, B is in the glass composition₂O₃The lower limit of the amount of (c) may be: greater than or equal to 0.1 mole%, greater than or equal to 0.2 mole%, greater than or equal to 0.3 mole%, greater than or equal to 0.4 mole%, greater than or equal to 0.5 mole%, greater than or equal to 0.6 mole%, greater than or equal to 0.7 mole%, greater than or equal to 0.8 mole%, greater than or equal to 0.9 mole%, or even greater than or equal to 1.0 mole%. In an embodiment, B in the glass composition₂O₃The upper limit of the amount of (b) may be: less than or equal to 6 mole%, less than or equal to 5.5 mole%, less than or equal to 5.0 mole%, less than or equal to 4.5 mole%, less than or equal to 4.0 mole%, less than or equal to 3.5 mole%, or even less than or equal to 3.0 mole%. It is understood that B in the glass composition₂O₃The amount of (A) may be as described by B herein₂O₃Any one of the lower limits of (1) and B₂O₃Within a range formed by any of the upper limits of (1).

For example, the glass composition constituting space B contains B₂O₃The amount of (b) may be greater than or equal to 0.1 mol% and less than or equal to 6 mol%, but is not limited thereto. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 0.2 mol% and less than or equal to 6.0 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 0.3 mol% and less than or equal to 6.0 mol%. In an embodiment, B in the glass composition₂O₃Is greater thanOr 0.4 mol% and 6.0 mol% or less. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 0.3 mol% and less than or equal to 5.5 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 0.3 mol% and less than or equal to 5.0 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 0.3 mol% and less than or equal to 4.5 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 0.3 mol% and less than or equal to 4.0 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 0.3 mol% and less than or equal to 3.5 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 0.3 mol% and less than or equal to 3.0 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 0.3 mol% and less than or equal to 2.5 mol%. In an embodiment, B in the glass composition₂O₃The amount of (b) is greater than or equal to 0.3 mol% and less than or equal to 2.0 mol%.

The glass composition constituting the space B further contains one or more alkali oxides. In this context, the sum of all basic oxides (in mol%) is expressed as R₂And O. In particular, R₂O is Na present in the glass composition₂O (mol%), K₂O (mol%) and Li₂Sum of O (mol%). Like B₂O₃The alkali oxide helps to increase the softening point and molding temperature of the glass composition, thereby compensating for the higher SiO in the glass composition₂The amount results in an increase in the softening point and molding temperature of the glass composition. The reduction in softening point and molding temperature, a phenomenon known as "mixed alkali effect", can also be further strengthened by including a combination of alkali oxides (e.g., two or more alkali oxides) in the glass composition. However, it was found that if the amount of the basic oxide is too high, the average thermal expansion coefficient of the glass composition increases to be greater than100x10^-7This is undesirable/° c.

In embodiments, the amount of basic oxide (i.e., R) in the glass composition₂The amount of O) may be greater than or equal to 11 mol% and less than or equal to 23 mol%. In an embodiment, R in the glass composition₂The lower limit of the amount of O may be: greater than or equal to 11 mole%, greater than or equal to 11.5 mole%, greater than or equal to 12 mole%, greater than or equal to 12.5 mole%, greater than or equal to 13 mole%, greater than or equal to 13.5 mole%, greater than or equal to 14 mole%, or even greater than or equal to 14.5 mole%. In an embodiment, R in the glass composition₂The upper limit of the amount of O may be: less than or equal to 23 mole%, less than or equal to 23.5 mole%, less than or equal to 22 mole%, less than or equal to 21.5 mole%, less than or equal to 21 mole%, less than or equal to 20.5 mole%, less than or equal to 20 mole%, less than or equal to 19.5 mole%, less than or equal to 19 mole%, less than or equal to 18.5 mole%, less than or equal to 18 mole%, less than or equal to 17.5 mole%, or even less than or equal to 17 mole%. It is understood that R in the glass composition₂The amount of O can be in the range of R as described herein₂Any of the lower limits of O and R₂Any of the upper limits of O.

For example, the glass composition constituting the space B contains R₂The amount of O may be greater than or equal to 11 mol% and less than or equal to 23 mol%, but is not limited thereto. In an embodiment, R in the glass composition₂The amount of O is not less than 11 mol% and not more than 22 mol%. In an embodiment, R in the glass composition₂The amount of O is not less than 11 mol% and not more than 21 mol%. In an embodiment, R in the glass composition₂The amount of O is not less than 11 mol% and not more than 20 mol%. In an embodiment, the glass composition comprises R₂The amount of O may be greater than or equal to 11 mol% and less than or equal to 19 mol%. In an embodiment, R in the glass composition₂The amount of O is greater than or equal to 11 mol% and less than or equal to 18 mol%. In factIn embodiments, R in the glass composition₂The amount of O is greater than or equal to 11 mol% and less than or equal to 17 mol%. In an embodiment, R in the glass composition₂The amount of O is greater than or equal to 12 mol% and less than or equal to 20 mol%. In an embodiment, the glass composition comprises R₂The amount of O may be greater than or equal to 13 mol% and less than or equal to 20 mol%. In an embodiment, R in the glass composition₂The amount of O is greater than or equal to 14 mol% and less than or equal to 20 mol%. In an embodiment, R in the glass composition₂The amount of O is greater than or equal to 15 mol% and less than or equal to 20 mol%. In an embodiment, R in the glass composition₂The amount of O is greater than or equal to 16 mol% and less than or equal to 20 mol%.

The basic oxide Li was found₂O has a significant effect on lowering the melting point, softening point and molding temperature of the glass composition, thereby compensating for the higher concentration of SiO in the glass composition₂The resulting reduction in formability of the glass composition is effective. However, as noted herein, lithium ions in glass are highly mobile and thus tend to migrate out of the glass. When the glass is coated (e.g., a metal layer, etc.), or when the glass is in contact with a liquid, lithium ions leached from the glass may contaminate or degrade the coating and/or the liquid. Thus, in the embodiments described herein, the glass composition is substantially free of Li₂O (i.e., R)₂O is substantially free of Li₂O)。

In an embodiment of the glass composition constituting the space B, the alkali oxide (R)₂O) comprises Na₂And O. As noted herein, an alkaline oxide (e.g., Na) is added₂O) lowers the softening point and molding temperature of the glass composition, thereby compensating for the higher SiO in the glass composition₂The amount results in an increase in the softening point and molding temperature of the glass composition. However, if Na₂If the amount of O is too high, the thermal expansion coefficient of the glass composition becomes too high, which is not desirable.

In the presence of an alkaline oxide comprising Na₂In the O embodiment, Na is present in the glass composition₂The amount of O may be greater than or equal to 11 mol% to improve the formability of the glass composition. Na in glass composition₂The amount of O may be less than or equal to 18 mol% so that the coefficient of thermal expansion is not undesirably high. Thus, Na in the glass composition₂The amount of O is greater than or equal to 11 mol% and less than or equal to 18 mol%. In an embodiment, Na in the glass composition₂The lower limit of the amount of O may be: greater than or equal to 11 mole%, greater than or equal to 11.5 mole%, greater than or equal to 12 mole%, greater than or equal to 12.5 mole%, greater than or equal to 13 mole%, greater than or equal to 13.5 mole%, greater than or equal to 14 mole%, greater than or equal to 14.5 mole%, or even greater than or equal to 15 mole%. In an embodiment, Na in the glass composition₂The upper limit of the amount of O may be: less than or equal to 18 mole%, less than or equal to 17.5 mole%, less than or equal to 17 mole%, less than or equal to 16.5 mole%, less than or equal to 16 mole%, or even less than or equal to 15.5 mole%. It is understood that Na in the glass composition₂The amount of O can be Na as described herein₂Any of the lower limits of O and Na₂Any of the upper limits of O.

For example, the glass composition constituting the space B contains R₂The amount of O may be greater than or equal to 11 mol% and less than or equal to 18 mol%, but is not limited thereto. In an embodiment, Na in the glass composition₂The amount of O is greater than or equal to 12 mol% and less than or equal to 18 mol%. In an embodiment, Na in the glass composition₂The amount of O is greater than or equal to 13 mol% and less than or equal to 18 mol%. In an embodiment, Na in the glass composition₂The amount of O is greater than or equal to 14 mol% and less than or equal to 18 mol%. In an embodiment, Na in the glass composition₂The amount of O is greater than or equal to 15 mol% and less than or equal to 18 mol%. In an embodiment, Na in the glass composition₂The amount of O is greater than or equal to 12 mol% and less than or equal to 17 mol%. In an embodiment, in the glass compositionNa of (2)₂The amount of O is greater than or equal to 12 mol% and less than or equal to 16 mol%. In an embodiment, Na in the glass composition₂The amount of O is greater than or equal to 13 mol% and less than or equal to 16 mol%.

Basic oxide (R) in glass composition constituting space B₂O) may optionally include K₂And O. Similar to Na₂O, addition of K₂O lowers the softening point and molding temperature of the glass composition, thereby compensating for the higher SiO in the glass composition₂The amount results in an increase in the softening point and molding temperature of the glass composition. However, if K₂If the amount of O is too high, the thermal expansion coefficient of the glass composition becomes too high, which is not desirable. Therefore, it is desirable to limit K in the glass composition₂The amount of O present.

In embodiments, the glass composition comprising space B may be substantially free of K₂And O. In the presence of a basic oxide comprising K₂In O embodiment, K present in the glass composition₂The amount of O may be greater than 0 mole%, for example: greater than or equal to 0.5 mol%, thereby contributing to improved formability of the glass composition. K₂The amount of O is less than or equal to 4 mol% so that the thermal expansion coefficient is not undesirably high. Thus, K in the glass composition₂The amount of O may be greater than or equal to 0.5 mol% and less than or equal to 4 mol%. In an embodiment, K in the glass composition₂The lower limit of the amount of O may be: greater than or equal to 0.5 mole%, greater than or equal to 0.75 mole%, or even greater than or equal to 1.0 mole%. In an embodiment, K in the glass composition₂The upper limit of the amount of O may be: less than or equal to 4 mole%, less than or equal to 3.75 mole%, less than or equal to 3.5 mole%, less than or equal to 3.25 mole%, less than or equal to 3 mole%, less than or equal to 2.75 mole%, less than or equal to 2.5 mole%, less than or equal to 2.25 mole%, less than or equal to 2.0 mole%, less than or equal to 1.75 mole%, or even less than or equal to 1.5 mole%. It is understood that K is the glass composition₂The amount of O can be in K as described herein₂Lower limit of OAny one of (1) and K₂Any of the upper limits of O.

For example, the glass composition constituting the space B contains K₂The amount of O may be greater than or equal to 0.5 mol% to less than or equal to 4 mol%, but is not limited thereto. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 0.75 mol% and less than or equal to 3.75 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 0.75 mol% and less than or equal to 3.5 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 0.75 mol% and less than or equal to 3.25 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 0.75 mol% and less than or equal to 3.0 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 0.75 mol% and less than or equal to 2.75 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 0.75 mol% and less than or equal to 2.5 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 0.75 mol% and less than or equal to 2.25 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 0.75 mol% and less than or equal to 2.0 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 0.75 mol% and less than or equal to 1.75 mol%. In an embodiment, K in the glass composition₂The amount of O is greater than or equal to 0.75 mol% and less than or equal to 1.5 mol%.

The glass composition constituting the space B further contains fluorine (F)₂). The addition of fluorine to the glass composition greatly lowers the softening point and molding temperature of the glass composition, achieving SiO in the glass₂In the glass composition, thereby improving the chemical durability of the glass composition. Thus, addition of F can be employed₂To compensate for the higher SiO₂A decrease in formability of the glass composition in an amount.

In embodiments, the glass composition making up space B may comprise greater than 2.5 mol% F₂(e.g., greater than or equal to 3.0 mol% F₂) Thereby enhancing the formability of the glass composition. F₂Is less than or equal to 5 mole%. If F₂Too high a concentration of (b) may cause the glass to become unstable and crystallize. When Al in the glass₂O₃When insufficient, for F above 5 mol% and even lower₂Concentrations, alkali and alkaline earth fluoride crystals can become problematic, particularly when the glass is reheated above the annealing point. Thus, in embodiments of the glass compositions comprising space B described herein, the glass composition comprises F₂The amount of (b) is generally greater than or equal to 2.5 mol% and less than or equal to 5 mol%. In an embodiment, F in the glass composition₂The lower limit of the amount of (c) may be: greater than or equal to 2.5 mole%, greater than or equal to 2.75 mole%, greater than or equal to 3.0 mole%, or even greater than or equal to 3.25 mole%. In an embodiment, F in the glass composition₂The upper limit of the amount of (b) may be: less than or equal to 5 mole%, less than or equal to 4.75 mole%, less than or equal to 4.5 mole%, less than or equal to 4.25 mole%, less than or equal to 4.0 mole%, less than or equal to 3.75 mole%, or even less than or equal to 3.5 mole%. It is understood that F in the glass composition₂The amount of (A) can be as described by F herein₂Any one of the lower limits of (1) and F₂Within a range formed by any of the upper limits of (1).

For example, the glass composition constituting the space B contains R₂The amount of O may be greater than or equal to 2.5 mol% and less than or equal to 5.0 mol%, but is not limited thereto. In an embodiment, F in the glass composition₂The amount of (b) is greater than or equal to 2.75 mol% and less than or equal to 5.0 mol%. In an embodiment, F in the glass composition₂The amount of (b) is greater than or equal to 3.0 mol% and less than or equal to 5.0 mol%. In an embodiment, F in the glass composition₂The amount of (b) is greater than or equal to 3.25 mol% and less than or equal to 5.0 mol%. In an embodiment, F in the glass composition₂The amount of (b) is greater than or equal to 3.5 mol% and less than or equal to 5.0 mol%. In the embodimentF in glass composition₂The amount of (b) is greater than or equal to 3.75 mol% and less than or equal to 5.0 mol%. In an embodiment, F in the glass composition₂The amount of (b) is greater than or equal to 3.0 mol% and less than or equal to 4.5 mol%. In an embodiment, F in the glass composition₂The amount of (b) is greater than or equal to 3.0 mol% and less than or equal to 4.25 mol%. In an embodiment, F in the glass composition₂The amount of (b) is greater than or equal to 3.0 mol% and less than or equal to 4.0 mol%. In an embodiment, F in the glass composition₂The amount of (b) is greater than or equal to 3.0 mol% and less than or equal to 3.75 mol%.

In an embodiment, the glass composition constituting the space B may optionally include ZnO. The addition of ZnO to the glass composition lowers the softening point and molding temperature of the glass composition, thereby compensating for the higher SiO in the glass composition₂The amount results in an increase in the softening point and molding temperature of the glass composition. It is noteworthy that the addition of ZnO does not increase the average coefficient of thermal expansion of the glass composition as much as some other modifiers (e.g., the basic and/or alkaline earth oxides CaO, BaO, and SrO) over the temperature range of 20 ℃ to 300 ℃. Thus, the benefits of adding ZnO to lower the softening point and molding temperature can be maximized without significantly increasing the average coefficient of thermal expansion of the glass composition.

Embodiments of the glass composition in compositional space B may be substantially free of ZnO. Some embodiments of the glass composition making up space B may include greater than 0 mol% ZnO (e.g., greater than or equal to 0.1 mol% ZnO) to enhance the formability of the glass composition. The concentration of ZnO is less than or equal to 3.0 mol% so as not to reduce the liquidus viscosity of the glass composition. Thus, in embodiments where the glass composition comprises ZnO, the glass composition typically comprises ZnO in an amount greater than or equal to 0.1 mol% and less than or equal to 3.0 mol%. In embodiments, the lower limit of the amount of ZnO in the glass composition may be: greater than or equal to 0.1 mole%, greater than or equal to 0.2 mole%, greater than or equal to 0.3 mole%, greater than or equal to 0.4 mole%, greater than or equal to 0.5 mole%, greater than or equal to 0.6 mole%, greater than or equal to 0.7 mole%, greater than or equal to 0.8 mole%, greater than or equal to 0.9 mole%, or even greater than or equal to 1 mole%. In embodiments, the upper limit of the amount of ZnO in the glass composition may be: less than or equal to 3.0 mole%, less than or equal to 2.75 mole%, less than or equal to 2.5 mole%, less than or equal to 2.25 mole%, or even less than or equal to 2.0 mole%. It is to be understood that the amount of ZnO in the glass composition may be within a range formed by any of the lower limits of ZnO and any of the upper limits of ZnO described herein.

For example, the glass composition constituting the space B may contain ZnO in an amount of greater than or equal to 0.5 mol% and less than or equal to 3.0 mol%, but is not limited thereto. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 0.5 mol% and less than or equal to 2.75 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 0.5 mol% and less than or equal to 2.5 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 0.5 mol% and less than or equal to 2.25 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 0.5 mol% and less than or equal to 2.0 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 0.5 mol% and less than or equal to 1.75 mol%. In an embodiment, the amount of ZnO in the glass composition is greater than or equal to 0.5 mol% and less than or equal to 1.5 mol%.

In embodiments of the glass composition in compositional space B, the glass composition may be substantially free of other constituent components, including but not limited to: alkaline earth oxides (e.g., MgO, CaO, SrO, and BaO), P₂O₅And Fe₂O₃。

Furthermore, as described above, the glass composition constituting space B is chemically durable and resistant to decomposition in acid, alkali and water as determined by the acid and alkali tests described herein and the ISO720 standard. The chemical durability of the glass composition makes the glass composition particularly suitable for applications where the glass is in contact with liquids, including but not limited to acidic liquids, alkaline liquids, and water-based liquids.

The glass composition constituting space B herein has a resistance to hydrolysis of ISO720 type HGA2 or type HGA 1. In embodiments, the glass compositions described herein may have an ISO720 type HGA1 resistance to hydrolysis. In embodiments, the glass composition making up space B may have less than 10mg/cm after exposure to the acid test²Less than or equal to 1mg/cm²Or even less than or equal to 0.1mg/cm²The weight loss of (c). In embodiments, the glass composition making up space B may have less than 10mg/cm after exposure to the alkali test²Less than or equal to 5mg/cm²Or even less than or equal to 2mg/cm²The weight loss of (c).

In embodiments of the glass compositions comprising space B described herein, the glass composition has greater than or equal to 80x10 over a temperature range of 20 ℃ to 300 ℃^-7V. and less than or equal to 92x10^-7Average Coefficient of Thermal Expansion (CTE) at/° C. For example, in embodiments, the glass composition has greater than or equal to 85x10 over a temperature range of 20 ℃ to 300 ℃^-788x10 or less per DEG C^-7Average Coefficient of Thermal Expansion (CTE) at/° C.

As described herein, the glass composition has a lower softening point and molding temperature. This improves the ease of remoulding the glass composition from the stock material into its final form. These lower temperatures may also extend the useful life of the mold in contact with the glass, as the lower molding temperatures reduce oxidation of the metal parts of the mold and minimize chemical reactions between the mold and the glass composition.

In embodiments of the glass compositions making up space B described herein, the glass compositions have a softening point less than or equal to 680 ℃. In embodiments, the glass composition has a softening point less than or equal to 670 ℃ or even less than or equal to 660 ℃.

In embodiments of the glass compositions comprising space B described herein, the glass composition has a molding temperature less than or equal to 620 ℃. In embodiments, the glass composition has a molding temperature of less than or equal to 615 ℃, less than or equal to 610 ℃, or even less than or equal to 605 ℃.

The glass composition making up space B may generally have a strain point greater than or equal to about 400 ℃ and less than or equal to about 500 ℃ or even greater than or equal to about 400 ℃ and less than or equal to about 450 ℃. The glass composition may also have an anneal point of greater than or equal to about 400 ℃ and less than or equal to about 500 ℃, or even greater than or equal to about 450 ℃ and less than or equal to about 500 ℃.

In some embodiments, the glass composition making up space B can have a liquidus viscosity greater than or equal to 90 kilopoise (kP) such that the glass is compatible with sheet forming processes (i.e., fusion draw processes, slot draw processes, and the like).

The glass composition constituting the space a and the space B is formed by: for batches of glass raw materials (e.g., SiO₂、Al₂O₃Powders of alkali oxides, alkaline earth oxides, etc.) are mixed so that the batch of glass raw materials has a desired composition. The glass raw material batch materials are then heated to form a molten glass composition, and subsequently cooled and solidified to form the glass composition. During the curing process (i.e., when the glass composition is plastically deformable), the glass composition can be shaped using standard shaping techniques to shape the glass composition into a desired final form. Alternatively, the glass articles may be formed into stock form, such as sheets or tubes, and subsequently reheated and formed into the desired final form, such as by molding.

Examples

The embodiments described herein are further illustrated by the following examples.

Example 1

A sample of the glass composition from composition space a is melted and formed, and the properties of the sample are measured or modeled (modeled values are indicated by "-"). The results are reported in tables 1A, 1B, 2A and 2B below. The acid consumption for the ISO720 test was recorded as 0.02 moles/L HCl per gram of glass particles tested. Acid weight loss was recorded after exposing the glass samples to the acid test described herein. Alkali weight loss was recorded after exposing the glass samples to the alkali test described herein.

Samples 1-5 of table 1A and samples 6-9 of table 1B have liquidus viscosities greater than 90kP, indicating that the glass compositions of these samples may be compatible with sheet forming processes such as fusion draw processes and slot draw processes. The samples in tables 1A and 1B have a lower softening point of less than 660 ℃ and a lower molding temperature of less than 630 ℃, indicating that these glass compositions can be easily remolded to form glass articles with 3-dimensional shapes, with a low risk of mold oxidation and/or reaction with mold materials. Furthermore, the samples in tables 1A and 1B have a hydrolysis resistance of grade HGA2 or grade HGA1, indicating that these glass compositions do not readily decompose after contact with aqueous solutions, whereby these glasses despite having a low concentration of SiO₂But is chemically durable. The samples in tables 1A and 1B also each have a temperature of less than 88x10 averaged over a temperature range of about 20 ℃ to about 300 ℃^-7Average coefficient of thermal expansion per deg.C.

Without wishing to be bound by theory, it is believed that the properties of the glass compositions identified in tables 1A and 1B are due to the combination of the constituent components in the glass, and in particular, to the content of ZnO relative to other modifiers. More specifically, the addition of ZnO helps to lower the softening point and molding temperature of the glass composition without significantly increasing the average coefficient of thermal expansion. For samples 1-9 in tables 1A and 1B, limiting the ZnO content to less than 16 mol% helps to reduce crystallization of the glass composition and maintain the liquidus viscosity of the glass composition at a level greater than 90 kP. Further, the use of a mixed alkaline earth oxide or alkali oxide mixed with ZnO contributes to lowering the softening point and molding temperature of the glass composition and also contributes to lowering the liquidus temperature of the glass. Specifically, samples 3 and 5 (which did not contain alkaline earth oxides) had higher softening points, molding temperatures, and liquidus temperatures than glass compositions comprising ZnO in combination with alkaline earth oxides. Furthermore, it was found that the addition of ZnO improves the hydrolysis resistance of the glass composition according to ISO 720.

TABLE 1A

TABLE 1B

Samples 11-20 of tables 2A and 2B have lower liquidus viscosities than samples 1-9 of tables 1A and 1B. Specifically, the liquidus viscosity of the samples in tables 2A and 2B is less than 50 kP. These lower liquidus viscosities are believed to be due to the higher levels of ZnO in the samples of tables 2A and 2B. Without wishing to be bound by theory, it is believed that the higher amount of ZnO in these glass compositions results in the formation of zinc silicate (willemite, Zn) in the liquidus phase₂SiO₄). It is believed that the silicozincite phase readily comes out of solution, thereby lowering the liquidus viscosity.

In addition to having a low liquidus viscosity, the samples in tables 2A and 2B also have a lower softening point of less than 660 ℃ and a lower molding temperature of less than 620 ℃, indicating that these glass compositions can be easily re-molded to form glass articles having a 3-dimensional shape, with a low risk of mold oxidation and/or reaction with mold materials. Similar to the liquidus viscosity, it is believed that the lower molding temperatures of these samples relative to the samples in tables 1A and 1B are due at least in part to the higher concentration of ZnO in the samples of tables 2A and 2B.

The samples in tables 2A and 2B had a hydrolysis resistance of grade HGA2 or grade HGA1, indicating that these glass compositionsDecomposition does not readily occur after contact with aqueous solutions, whereby these glasses despite having a low concentration of SiO₂But is chemically durable. For all glass compositions in tables 1A-2B, it is believed that despite having a lower SiO₂The concentration, but improvement in the hydrolysis resistance of the glass is due at least in part to the addition of ZnO to the glass composition.

The samples in tables 2A and 2B also each have a temperature of less than 88x10 averaged over a temperature range of about 20 ℃ to about 300 ℃^-7Average coefficient of thermal expansion per deg.C.

TABLE 2A

TABLE 2B

Example 2

A sample of the glass composition from composition space B is melted and formed, and the properties of the sample are measured or modeled (modeled values are indicated by "-"). The results are shown in table 3 below. The acid consumption for the ISO720 test was recorded as 0.02 moles/L HCl per gram of glass particles tested. Acid weight loss was recorded after exposing the glass samples to the acid test described herein. Alkali weight loss was recorded after exposing the glass samples to the alkali test described herein.

Samples 21-26 of Table 3 have liquidus viscosities greater than 200kP, indicating the glass composition of these samples and sheet forming tools such as fusion draw processes and slot draw processesThe process is compatible. The samples in table 3 have a lower softening point of less than 680 ℃ and a lower molding temperature of less than 620 ℃, indicating that these glass compositions can be easily re-molded to form glass articles with 3-dimensional shapes, with a low risk of mold oxidation and/or reaction with mold materials. Furthermore, the samples in table 3 have a hydrolysis resistance of grade HGA2, indicating that these glass compositions do not readily decompose after contact with aqueous solutions, whereby these glasses despite having a low concentration of SiO₂But is chemically durable. The samples in Table 3 also each have less than 92x10 averaged over a temperature range of about 20 ℃ to about 300 ℃^-7Average coefficient of thermal expansion per deg.C.

While not wishing to be bound by theory, it is believed that the lower softening point and molding temperature of the glass compositions identified in Table 3 are due to the addition of F to the glass compositions₂The result is. Specifically, the glass compositions in Table 3 each have a higher concentration of SiO₂. As described herein, the softening point and molding temperature of the glass composition generally follows that of SiO₂The concentration increases. However, in the samples of table 3, the softening point and molding temperature of the glass composition were maintained at lower values. In particular, despite the significantly higher concentration of SiO₂The molding temperatures for the samples in Table 3 were similar to the glass molding temperatures identified in tables 1A-2B.

TABLE 3

It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus, it is intended that the present description cover the modifications and variations of the various embodiments described herein provided they come within the scope of the appended claims and their equivalents.