Patent US2270401A successfully refreshed from Google Patents.
US4792536A
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US
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Transparent infrared absorbing glass and method of making
Assignee: PPG Industries Ohio Inc
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Filing: 1987-06-29
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Granted: 1988-12-20
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Expires: 2007-06-29
Abstract
Abstract A glass product having high visible transmittance, low infrared transmittance, and, optionally, reduced ultraviolet transmittance is produced in a manner compatible with continuous, commercial manufacture of flat glass by employing a moderate amount of iron in the glass composition and controlling reducing conditions to maintain a relatively large portion of the iron in the ferrous state.
Inventors
- 👤 George A. Pecoraro
- 👤 Larry J. Shelestak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:46
CPC Classifications
C; C03; C03C; C03C4/00; C03C4/08; C03C4/082; C03C4/10; C03B; C03B3/00; C03B3/02; C03B5/00; C03B5/04; C03B5/12; C03B5/16; C03B5/18; C03B5/187; C03B5/1875; C03B5/225; C03B5/2252; C03C13/00; C03C3/00; C03C3/04; C03C3/076; C03C3/083; C03C3/085; C03C3/087; C03C4/02; Y; Y02; Y02P; Y02P40/00; Y02P40/50; Y02P40/57
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
146 words
A method of manufacturing soda-lime-silica flat glass in a continuous process including feeding raw materials to a melting operation that includes separate liquefying and refining stages, passing from the melting operation to a flat glass forming operation a continuous stream of molten glass having at least 0.45 percent by weight iron expressed as Fe 2 O 3 , forming the glass into a flat glass product in the forming operation, melting the raw materials in a thin layer in the liquefying stage while controlling oxidation-reduction conditions in that stage and in subsequent stages so as to yield a glass having at least 35 percent of the iron in the ferrous state expressed as FeO and which when formed into a flat glass product of suitable thickness exhibits the combination of luminous transmittance of at least 65 percent and infrared transmittance of no more than 15 percent.
Claim 2
Independent Claim
146 words
A method of manufacturing soda-lime-silica flat glass in a continuous process including feeding raw materials to a melting operation that includes separate liquefying and refining stages, passing from the melting operation to a flat glass forming operation a continuous stream of molten glass having at least 0.45 percent by weight iron expressed as Fe 2 O 3 , forming the glass into a flat glass product in the forming operation, melting the raw materials in a thin layer in the liquefying stage while controlling oxidation-reduction conditions in that stage and in subsequent stages so as to yield a glass having at least 35 percent of the iron in the ferrous state expressed as FeO and which when formed into a flat glass product of suitable thickness exhibits the combination of luminous transmittance of at least 65 percent and infrared transmittance of no more than 15 percent.
Claim 3
Dependent Claim
26 words
The method of claim 1 wherein the glass is provided with a total iron content less than 0.65 percent expressed as Fe 2 O 3 .
Claim 4
Dependent Claim
26 words
The method of claim 1 wherein the oxidation--reduction conditions are controlled so as to provide at least 40 percent of the iron in the ferrous state.
Claim 5
Dependent Claim
25 words
The method of claim 1 wherein the sulfur content of the product glass is less than 0.02 percent by weight expressed as SO 3 .
Claim 6
Dependent Claim
26 words
The method of claim 4 wherein the ratio of iron in the ferrous state to total iron in the product glass is at least 50 percent.
Claim 7
Dependent Claim
25 words
The method of claim 5 wherein the sulfur content of the product glass is less than 0.01 percent by weight expressed as SO 3 .
Claim 8
Dependent Claim
32 words
The method of claim 1 wherein the oxidation-reduction conditions are controlled in the melting operation to yield a glass product having at least 0.23 percent by weight ferrous iron expressed as FeO.
Claim 9
Dependent Claim
18 words
The method of claim 7 wherein fuel-rich combustion is provided in the melting operation to provide reducing conditions.
Claim 10
Dependent Claim
28 words
The method of claim 7 wherein reducing conditions are provided in the melting operation by including carbonaceous material in the raw materials being fed to the melting operation.
Claim 11
Dependent Claim
33 words
The method of claim 1 wherein the raw materials being fed to the melting operation include an iron source in an amount sufficient to yield the desired iron content of the glass product.
Claim 12
Dependent Claim
24 words
The method of claim 10 wherein the iron source included in the raw materials includes a majority of the iron in the ferrous stage.
Claim 13
Dependent Claim
20 words
The method of claim 1 wherein a source of iron is added to molten glass downstream from the melting operation.
Claim 14
Dependent Claim
25 words
The method of claim 12 wherein a substantial portion of the added iron is in a reduced state relative to Fe 2 O 3 .
Claim 15
Dependent Claim
31 words
The method of claim 12 wherein a portion of the product glass iron content is provided by an iron source included in the raw materials being fed to the melting operation.
Claim 16
Dependent Claim
21 words
The method of claim 1 wherein the molten glass is brought into contact with molten metal prior to the forming operation.
Claim 17
Dependent Claim
18 words
The method of claim 15 wherein the molten glass is stirred while in contact with the molten metal.
Claim 18
Dependent Claim
26 words
The method of claim 1 wherein the glass is provided with a total iron content less than 0.60 percent expressed as Fe 2 O 3 .
Claim 19
Dependent Claim
19 words
The method of claim 15 wherein the forming operation includes supporting molten glass on a pool of molten metal.
Claim 20
Dependent Claim
16 words
The method of claim 16 wherein the refining stage includes subjecting molten glass to subatmospheric pressure.
Claim 21
Dependent Claim
25 words
The method of claim 17 wherein the sulfur content of the glass is reduced below 0.02 percent expressed as SO 3 by the refining stage.
Claim 22
Dependent Claim
32 words
The method of claim 7 wherein the oxidation-reduction conditions are controlled in the melting operation to yield a glass product having at least 0.25 percent by weight ferrous iron expressed as FeO.
Claim 23
Dependent Claim
67 words
The method of claim 1 wherein the glass product has a composition consisting essentially of, on a weight basis: 66 to 75% SiO 2 , 12-20% Na 2 O, 7-12% CaO, 0-5% MgO, 0-4% Al 2 O 3 , 0-3% K 2 O, 0-1% Fe 2 O 3 , and 0-1.5% total of CeO 2 , TiO 2 , V 2 O 5 or MoO 3 .
Claim 24
Dependent Claim
112 words
A soda-lime-silica glass article having a composition consisting essentially of, on a weight basis: 66 to 75% SiO 2 , 12-20% Na 2 O, 7-12% CaO, 0-5% MgO, 0-4% Al 2 O 3 , 0-3% K 2 O, 0.45-1% Fe 2 O 3 , 0-1.5% total of CeO 2 , TiO 2 , V 2 O 5 or MoO 3 , at least 50 percent of the iron being in the ferrous state expressed as FeO, less than 0.02 percent by weight sulfur expressed as SO 3 , and exhibiting luminous transmittance of at least 65 percent and total solar infrared transmittance of no more than 15 percent at a selected thickness.
Claim 25
Dependent Claim
112 words
A soda-lime-silica glass article having a composition consisting essentially of, on a weight basis: 66 to 75% SiO 2 , 12-20% Na 2 O, 7-12% CaO, 0-5% MgO, 0-4% Al 2 O 3 , 0-3% K 2 O, 0.45-1% Fe 2 O 3 , 0-1.5% total of CeO 2 , TiO 2 , V 2 O 5 or MoO 3 , at least 50 percent of the iron being in the ferrous state expressed as FeO, less than 0.02 percent by weight sulfur expressed as SO 3 , and exhibiting luminous transmittance of at least 65 percent and total solar infrared transmittance of no more than 15 percent at a selected thickness.
Claim 26
Dependent Claim
25 words
The article of claim 23 wherein the ferrous iron content expressed as FeO, is greater than 0.270 percent by weight of the total glass composition.
Claim 27
Dependent Claim
25 words
The article of claim 24 wherein the ferrous iron content, expressed as FeO, is less than 0.300 percent by weight of the total glass composition.
Claim 28
Dependent Claim
23 words
The article of claim 23 wherein the sulfur content, expressed as SO 3 , is less than 0.01% of the total glass composition.
Claim 29
Dependent Claim
29 words
The article of claim 23 wherein the total iron content, expressed as Fe 2 O 3 , is less than 0.65 percent by weight of the total glass composition.
Claim 30
Dependent Claim
10 words
The article of claim 23 comprising a flat glass sheet.
Claim 31
Dependent Claim
14 words
The article of claim 28 wherein the sheet is 2 to 6 millimeters thick.
Claim 32
Dependent Claim
17 words
The article of claim 28 wherein the sheet has traces of tin oxide in a surface portion.
Claim 33
Dependent Claim
18 words
The method of claim 1 wherein the glass is formed to a thickness of 2 to 6 millimeters.
Claim 34
Dependent Claim
18 words
The method of claim 31 wherein the transmittance properties are exhibited at a product thickness of 5 millimeters.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-12-20 | 1992-06-20 | 1992-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-20 | 1996-06-20 | 1996-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-20 | 2000-06-20 | 2000-12-20 | $7700.00 | Window Closed / Lapsed |