Dark gray, infrared absorbing glass composition and coated glass for privacy glazing

• US 5,393,593 A
• Filed: 10/12/1993
• Issued: 02/28/1995
• Est. Priority Date: 10/25/1990
• Status: Expired due to Term

• Current Assignee: Vitro Flat Glass LLC (Compagnie De Saint-Gobain)
• Original Assignee: PPG Industries Incorporated (Nouryon BV)
• Inventors: Kutilek, Luke A., Longobardo, Anthony V., Heithoff, Robert B., Gulotta, Joseph A., Krumwiede, John F.
• Primary Examiner(s): Robinson, Ellis P.
• Assistant Examiner(s): Speer, Timothy M.
• Application Number:
  US08/133,949
• Time in Patent Office: 504 Days
• Field of Search: 428/926, 428/428, 428/432, 428/212, 428/702, 501/71, 501/904, 501/905
• US Class Current: 428/220
• CPC Class Codes: C03C 1/10 to produce uniformly-coloured transparent products
• CPC Class Codes: C03C 3/087 containing calcium oxide, e.g. common sheet or container glass
• CPC Class Codes: C03C 4/02 for coloured glass
• CPC Class Codes: C03C 4/082 for infrared absorbing glass
• CPC Class Codes: Y10S 501/904 Infrared transmitting or absorbing
• CPC Class Codes: Y10S 501/905 Ultraviolet transmitting or absorbing
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree

Abstract

A neutral, dark gray, soda-lime-silica glass having luminous transmittance less than 35 percent, infrared transmittance less than 20 percent, and total solar energy transmittance less than 22 percent (all at 3.9 millimeter thickness) is produced with colorants consisting essentially of 1.0 to 2.2 percent by weight total iron, at least 0.20 percent FeO, 0.01 to 0.03 percent CoO, and 0.0005 to 0.005 percent Se. The flat glass product having such a composition is particularly suitable for use as privacy glazing. The use of the glass as a substrate for a reflectively coated product is also disclosed. A low transmittance, reflective coated article is disclosed comprising a soda-lime-silica glass substrate having luminous transmittance less than 35 percent, infrared transmittance less than 20 percent, and total solar energy transmittance less than 22 percent (all at 3.9 millimeter thickness) and a metal oxide coating having a luminous reflectance not more than 25 percent from the coated surface, and not more than 8 percent from the uncoated surface. The low transmittance coated glass product is particularly suitable for use as privacy glazing.

Claims

1. A neutral gray colored glass composition having a base glass portion comprising:

space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 66-75 percent by weight Na.sub.2 O 10-20 CaO 5-15 MgO 0-5 Al.sub.2 O.sub.3 0-5 K.sub.2 O 0-5 ______________________________________

and a colorant portion consisting essentially of;

space="preserve" listing-type="tabular">______________________________________ Fe.sub.2 O.sub.3 (total iron) greater than 1.00 and up to 1.7 percent by weight FeO at least 0.27 Se 0.001 up to but less than 0.005 CoO 0.01-0.02 ______________________________________

the glass having a luminous transmittance of no more than 32 percent, and a total solar infrared transmittance of less than 15 percent at a thickness of 3.9 millimeters.

2. The composition of claim 1 wherein the colorant portion includes greater than 1.0 to 1.3 percent by weight total iron expressed as Fe₂ O₃.

3. The composition of claim 1 wherein the FeO concentration is at least 0.30 weight percent.

4. The composition of claim 1 wherein the FeO concentration is at least 0.35 weight percent.

5. The composition of claim 1 wherein the colorant portion is selected so as to yield total solar infrared transmittance less than 13 percent at 3.9 millimeters thickness.

6. The composition of claim 1 wherein the colorant portion is selected so as to yield total solar infrared transmittance less than 10 percent at 3.9 millimeters thickness.

7. The composition of claim 1 wherein the color of the glass is characterized by dominant wavelengths in the range of 485 to 510 nanometers.

8. The composition of claim 7 wherein the color of the glass is characterized by an excitation purity of no higher than 15%.

9. The glass composition of claim 1 wherein the colorant portion is selected so as to yield a total solar energy transmittance of less than 25% at 3.9 mm thickness.

10. The composition as in claim 1 wherein said colorant portion includes 1.15-1.45 wt. % Fe₂ O₃, 0.25-0.40 wt. % FeO, 0.19-0.23 wt. % CoO, and 0.002-0.0035 wt. % Se, and further wherein said composition has a luminous transmittance of no greater than 25%, a total solar infrared transmittance of no greater than 15% and a total solar energy transmittance of no greater than 25% at 3.9 mm thickness.

11. The composition as in claim 10 wherein said colorant portion includes 1.18-1.26 wt. % Fe₂ O₃, 0.28-0.34 wt. % FeO, 0.195-0.215 wt. % CoO, and 0.0022-0.0031 wt. % Se, and further wherein said composition has a luminous transmittance of no greater than 21%, a total solar infrared transmittance of no greater than 12% and a total solar energy transmittance of no greater than 20% at 3.9 mm thickness.

12. An article of manufacture comprising a glass sheet having a base glass portion comprising:

space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 66-75 percent by weight Na.sub.2 O 10-20 CaO 5-15 MgO 0-5 Al.sub.2 O.sub.3 0-5 K.sub.2 O 0-5 ______________________________________

and a colorant portion consisting essentially of;

space="preserve" listing-type="tabular">______________________________________ Fe.sub.2 O.sub.3 (total iron) greater than 1.00 and up to 1.7 percent by weight FeO at least 0.27 Se 0.001 up to but less than 0.005 CoO 0.01-0.02 ______________________________________

the glass having a luminous transmittance of no more than 32percent, and total solar infrared transmittance less than 15 percent at a thickness of 3.9 millimeters.

13. The article of claim 12 wherein the sheet has a thickness of 2 to 10 millimeters.

14. The article of claim 12 wherein the sheet has a thickness of 3 to 6 millimeters.

15. The article of claim 12 wherein a surface portion of the sheet includes at least 0.05 percent by weight SnO₂.

16. The article of claim 12 wherein the luminous transmittance is less than 30 percent at a thickness of 3.9 millimeters.

17. The article of claim 12 wherein the colorant portion includes greater than 1.0 to 1.3 percent by weight total iron expressed as Fe₂ O₃.

18. The article of claim 12 wherein the FeO concentration is at least 0.30 weight percent.

19. The article of claim 12 wherein the FeO concentration is at least 0.35 weight percent.

20. The article of claim 12 wherein the colorant portion is selected so as to yield total solar infrared transmittance less than 13 percent at 3.9 millimeters thickness.

21. The article of claim 12 wherein the colorant portion is selected so as to yield total solar infrared transmittance less than 10 percent at 3.9 millimeters thickness.

22. The article of claim 12 wherein the color of the glass is characterized by dominant wavelengths in the range of 485 to 510 nanometers.

23. The article of claim 22 wherein the color of the glass is characterized by an excitation purity of no higher than 15%.

24. The article of claim 12 wherein the colorant portion is selected so as to yield a total solar energy transmittance of less than 25% at 3.9 mm thickness.

33. The article as in claim 12 wherein said colorant portion includes 1.15-1.45 wt. % Fe₂ O₃, 0.25-0.40 wt. % FeO, 0.19-0.23 wt. % CoO, and 0.002-0.0035 wt. % Se, and further wherein said glass has a luminous transmittance of no greater than 25%, a total solar infrared transmittance of no greater than 15% and a total solar energy transmittance of no greater than 25% at 3.9 mm thickness.

34. The article as in claim 33 wherein said colorant portion includes 1.18-1.26 wt. % Fe₂ O₃, 0.28-0.34 wt. % FeO, 0.195-0.215 wt. % CoO, and 0.0022-0.0031 wt. % Se, and further wherein said glass has a luminous transmittance of no greater than 21%, a total solar infrared transmittance of no greater than 12% and a total solar energy transmittance of no greater than 20% at 3.9 mm thickness.

25. A neutral gray colored glass composition having a base glass portion comprising:

space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 66-75 percent by weight Na.sub.2 O 10-20 CaO 5-15 MgO 0-5 Al.sub.2 O.sub.3 0-5 K.sub.2 O 0-5 ______________________________________

and a colorant portion consisting essentially of;

space="preserve" listing-type="tabular">______________________________________ Fe.sub.2 O.sub.3 (total iron) greater than 1.00 and up to 2.2 percent by weight FeO at least 0.20 Se 0.0005 up to but less than 0.005 CoO 0.010-0.030 ______________________________________

the glass having a luminous transmittance of no more than 35 percent, and a total solar infrared transmittance of less than 20 percent at a thickness of 3.9 millimeters.

26. The composition of claim 25 wherein the colorant portion includes greater than 1.0 to 1.7 percent by weight total iron expressed as Fe₂ O₃.

27. The composition of claim 25 wherein the FeO concentration is at least 0.27 weight percent.

28. The composition of claim 25 wherein the FeO concentration is between 0.27 to 0.50 weight percent.

29. The composition of claim 25 wherein the colorant portion is selected so as to yield total solar infrared transmittance less than 13 percent at 3.9 millimeters thickness.

30. The composition of claim 25 wherein the color of the glass is characterized by dominant wavelengths in the range of 485 to 580 nanometers.

31. The composition of claim 30 wherein the color of the glass is characterized by an excitation purity of no higher than 15%.

32. The glass composition of claim 25 wherein the colorant portion is selected so as to yield a total solar energy transmittance of less than 25% at 3.9 mm thickness.

35. An article of manufacture comprising a glass sheet having a base glass portion comprising:

space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 66-75 percent by weight Na.sub.2 O 10-20 CaO 5-15 MgO 0-5 Al.sub.2 O.sub.3 0-5 K.sub.2 O 0-5 ______________________________________

and a colorant portion consisting essentially of;

space="preserve" listing-type="tabular">______________________________________ Fe.sub.2 O.sub.3 (total iron) greater than 1.00 and up to 2.2 percent by weight FeO at least 0.20 Se 0.0005 up to but less than 0.005 CoO 0.010-0.030 ______________________________________

the glass having a luminous transmittance of no more than 35 percent, and total solar infrared transmittance less than 20 percent at a thickness of 3.9 millimeters.

36. The article of claim 35 wherein the sheet has a thickness of 2 to 10 millimeters.

37. The article of claim 35 wherein a surface portion of the sheet includes at least 0.05 percent by weight SnO₂.

38. The article of claim 35 wherein the luminous transmittance is less than 30 percent at a thickness of 3.9 millimeters.

39. The article of claim 35 wherein the colorant portion includes greater than 1.0 to 1.7 percent by weight total iron expressed as Fe₂ O₃.

40. The article of claim 35 wherein the FeO concentration is at least 0.27 weight percent.

41. The article of claim 35 wherein the FeO concentration is between 0.28 to 0.50 weight percent.

42. The article of claim 41 wherein the Fe₂ O₃ concentration is from greater than 1.0 to 1.2 weight percent.

43. The article of claim 41 wherein the Fe₂ O₃ concentration is from 1.3 to 1.7 weight percent.

44. The article of claim 35 wherein the colorant portion is selected so as to yield total solar infrared transmittance less than 13 percent at 3.9 millimeters thickness.

45. The article of claim 35 wherein the color of the glass is characterized by dominant wavelengths in the range of 485 to 580 nanometers.

46. The article of claim 45 wherein the color of the glass is characterized by an excitation purity of no higher than 15%.

47. The article of claim 35 wherein the colorant portion is selected so as to yield a total solar energy transmittance of less than 25% at 3.9 mm thickness.