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EP0469446A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Ultraviolet absorbing green tinted glass

Assignee: PPG Industries Ohio Inc
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Filing: 1991-07-24
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Granted: —
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Expires: 2011-07-24
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Abstract

Abstract A green tinted, ultraviolet absorbing glass is obtained by the addition of colorant to a standard soda-lime-silica base glass composition and a colorant includes less than 0.5 weight percent of cerium oxide (Ce0 2 ), greater than 0.85 weight percent of total iron expressed as Fe 2 0 3 and a ratio of ferric iron expressed as FeO to total iron of less than 0.275. The glass has a low ultraviolet transmittance, viz., no greater than 31 percent over the wavelength range of 300 to 390 nanometers at a reference glass thickness of 3.9 millimeters. An advantage of the glass of this invention over competing ultraviolet absorbing glass is the use of larger amounts of total iron and smaller proportions of iron in the ferrous state to obtain the low ultraviolet transmittance. In this manner, the amounts of cerium oxide which is expensive is reduced.

Inventors

  • 👤 Joseph Anthony Gulotta
  • 👤 Larry John Shelestak

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 02:28
CPC Classifications
C; C03; C03C; C03C4/00; C03C4/08; C03C4/02; C03C3/00; C03C3/04; C03C3/076; C03C3/095; C03C4/085

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 91 words
A green tinted, ultraviolet absorbing glass having a base glass composition comprising: Si0 2 68 - 75 weight% Na 2 0 10-20 CaO 5 - 15 MgO 0-5 A1 2 0 3 0 - K 2 0 0-5 and a colorant portion consisting essentially of: Ce0 2 Less than 0.5 weight % Total iron (as Fe 2 0 3 ) Greater than 0.85 weight % FeO/total iron Less than 0.275 weight percent exhibiting ultraviolet transmittance no greater than 31 percent (300 to 390 nanometers at a reference thickness of 3.9 millimeters.
Claim 2
Dependent Claim 91 words
A green tinted, ultraviolet absorbing glass having a base glass composition comprising: Si0 2 68 - 75 weight% Na 2 0 10-20 CaO 5 - 15 MgO 0-5 A1 2 0 3 0 - K 2 0 0-5 and a colorant portion consisting essentially of: Ce0 2 Less than 0.5 weight % Total iron (as Fe 2 0 3 ) Greater than 0.85 weight % FeO/total iron Less than 0.275 weight percent exhibiting ultraviolet transmittance no greater than 31 percent (300 to 390 nanometers at a reference thickness of 3.9 millimeters.
Claim 3
Dependent Claim 18 words
The glass of claim 1 wherein the glass contains less than 0.4 percent by weight Ce0 2 .
Claim 4
Dependent Claim 24 words
The glass of claim 1 wherein the glass exhibits luminous transmittance (illuminant A) of at least 70 percent at a thickness of 3.9 millimeters.
Claim 5
Dependent Claim 17 words
The glass of claim 1 wherein the glass exhibits a dominant wavelength from 495 to 535 nanometers.
Claim 6
Dependent Claim 25 words
The glass of claim 1 wherein the glass exhibits a total solar energy transmittance less than 45 percent at a reference thickness of 3.9 millimeters.

References Cited (Backward Citations)

US2860059A Cited
US3294556A Cited
EP0297404B1 Cited
WO1991007356A1 Cited
WO1991011402A1 Cited

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