Patent US4824712A successfully refreshed from Google Patents.
US4824712A
Expired / Lapsed
US
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Treatment of glass to reduce venting during thermal treatment and a glass article made thereby
Assignee: PPG Industries Inc
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Filing: 1985-10-08
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Granted: 1989-04-25
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Expires: 2005-10-08
Abstract
Abstract A method and composition for coating scored regions or holes in glass articles prior to heat treatment in order to maintain residual compressive stresses and reduce venting are disclosed. The method and composition of the present invention utilize silica-containing sols which gel and density and ultimately form glassy films during the heat treatment of the coated glass articles.
Inventors
- 👤 Charlene A. Falleroni
- 👤 Chia-Cheng Lin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:43
CPC Classifications
C; C03; C03B; C03B27/00; C03B27/012; C03C; C03C17/00; C03C17/02; Y; Y02; Y02P; Y02P40/00; Y02P40/50; Y02P40/57; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/24322; Y10T428/24331; Y10T428/24339; Y10T428/24347; Y10T428/31; Y10T428/315
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
90 words
A method of heat treating a glass sheet having a scored region comprising the steps of: a. coating said scored region with a sol composition prepared from an alkoxide and comprising silicon; b. hydrolyzing said alkoxide and polymerizing to form a gel; c. heating said glass sheet to a temperature above its strain point and below its melting point and sufficient to cause said gel to densify; d. maintaining said temperature for a sufficient time to cause said gel to form a glassy coating; and e. cooling said glass sheet.
Claim 2
Independent Claim
90 words
A method of heat treating a glass sheet having a scored region comprising the steps of: a. coating said scored region with a sol composition prepared from an alkoxide and comprising silicon; b. hydrolyzing said alkoxide and polymerizing to form a gel; c. heating said glass sheet to a temperature above its strain point and below its melting point and sufficient to cause said gel to densify; d. maintaining said temperature for a sufficient time to cause said gel to form a glassy coating; and e. cooling said glass sheet.
Claim 3
Dependent Claim
26 words
A method according to claim 1, wherein said sol comprises silicon and at least one metal selected from the group consisting of titanium, boron and sodium.
Claim 4
Dependent Claim
28 words
A method according to claim 2, wherein said coating has a molar ratio of 75 to 80 percent SiO 2 and 10 to 25 percent Na 2 O.
Claim 5
Dependent Claim
37 words
A method according to claim 1, wherein said scored region comprises a hole, having a circumferential wall, extending through the thickness of said glass sheet, and said coating step includes coating said circumferential wall of said hole.
Claim 6
Dependent Claim
27 words
A method according to claim 4, wherein said coating step further includes coating a portion of each surface of said glass sheet immediately adjacent to said hole.
Claim 7
Dependent Claim
25 words
A method according to claim 5, further including the step of shaping said glass sheet to a desired shape between said heating and cooling steps.
Claim 8
Dependent Claim
24 words
The method as in claim 1, wherein the cooling in said cooling step is rapid enough to impart a temper in said glass sheet.
Claim 9
Independent Claim
114 words
A method of heat treating a glass sheet having a scored region comprising the steps of: a. coating said scored region with a sol composition prepared from an alkoxide and comprising silicon and boron; b. hydrolzying said alkoxide and polymerizing to form a gel; c. heating said glass sheet to a temperature above its strain point and below its melting point and sufficient to densify said gel; d. maintaining said temperature for a sufficient time to cause said gel to form a glassy coating; and e. cooling said glass sheet, wherein said coating has a molar ratio of 55 to 80 percent SiO 2 and 20 to 45 percent B 2 O 3 .
Claim 10
Independent Claim
114 words
A method of heat treating a glass sheet having a scored region comprising the steps of: a. coating said scored region with a sol composition prepared from an alkoxide and comprising silicon and boron; b. hydrolzying said alkoxide and polymerizing to form a gel; c. heating said glass sheet to a temperature above its strain point and below its melting point and sufficient to densify said gel; d. maintaining said temperature for a sufficient time to cause said gel to form a glassy coating; and e. cooling said glass sheet, wherein said coating has a molar ratio of 55 to 80 percent SiO 2 and 20 to 45 percent B 2 O 3 .
Claim 11
Independent Claim
122 words
A method of heat treating a glass sheet having a scored region comprising the steps of: a. coating said scored region with a sol composition prepared from an alkoxide and comprising silica and at least one metal selected from the group consisting of titanium, boron and sodium, which sol forms a gel; b. heating said glass sheet to a temperature above its strain point and below its melting point and sufficient to cause said gel to densify; c. maintaining said temperature for a sufficient time to cause said gel to form a glassy coating; and d. cooling said glass sheet, wherein said coating has a molar ratio of 75 to 90 percent SiO 2 and 10 to 25 percent TiO 2 .
Claim 12
Independent Claim
122 words
A method of heat treating a glass sheet having a scored region comprising the steps of: a. coating said scored region with a sol composition prepared from an alkoxide and comprising silica and at least one metal selected from the group consisting of titanium, boron and sodium, which sol forms a gel; b. heating said glass sheet to a temperature above its strain point and below its melting point and sufficient to cause said gel to densify; c. maintaining said temperature for a sufficient time to cause said gel to form a glassy coating; and d. cooling said glass sheet, wherein said coating has a molar ratio of 75 to 90 percent SiO 2 and 10 to 25 percent TiO 2 .
Claim 13
Dependent Claim
41 words
A tempered glass article comprising a glass sheet having at least one hole extending entirely through its thickness, and a sol-gel coating fused to the wall of said hole, wherein said coating comprises SiO 2 and B 2 O 3 .
Claim 14
Dependent Claim
41 words
A tempered glass article comprising a glass sheet having at least one hole extending entirely through its thickness, and a sol-gel coating fused to the wall of said hole, wherein said coating comprises SiO 2 and B 2 O 3 .
Claim 15
Dependent Claim
32 words
A tempered glass article according to claim 10, wherein said coating has molar percentage ranges of 55 to 80 percent SiO 2 and 20 to 45 percent B 2 O 3 .
Claim 16
Dependent Claim
68 words
A tempered glass article comprising a glass sheet having at least one hole extending entirely through its thickness, and a sol-gel coating comprising silica fused to the wall of said hole and coating a portion of each surface of said glass sheet immediately adjacent to said hole, wherein said coating has molar percentages of 75 to 80 percent SiO 2 and 10 to 25 percent Na 2 O.
Claim 17
Dependent Claim
68 words
A tempered glass article comprising a glass sheet having at least one hole extending entirely through its thickness, and a sol-gel coating comprising silica fused to the wall of said hole and coating a portion of each surface of said glass sheet immediately adjacent to said hole, wherein said coating has molar percentages of 75 to 80 percent SiO 2 and 10 to 25 percent Na 2 O.
Claim 18
Dependent Claim
68 words
A tempered glass article comprising a glass sheet having at least one hole extending entirely through its thickness, and a sol-gel coating comprising silica fused to the wall of said hole and coating a portion of each surface of said glass sheet immediately adjacent to said hole, wherein said coating has molar percentages of 75 to 90 percent SiO 2 and 10 to 25 percent TiO 2 .
Claim 19
Dependent Claim
68 words
A tempered glass article comprising a glass sheet having at least one hole extending entirely through its thickness, and a sol-gel coating comprising silica fused to the wall of said hole and coating a portion of each surface of said glass sheet immediately adjacent to said hole, wherein said coating has molar percentages of 75 to 90 percent SiO 2 and 10 to 25 percent TiO 2 .
Claim 20
Independent Claim
98 words
A method of heat treating a glass sheet having a scored region comprising the steps of: coating said scored region with a sol-gel composition comprised essentially of boron and silica compositions and having a viscosity lower than that of said glass sheet; heating said glass sheet to a temperature above its strain point and below its melting point and sufficient to cause said sol-gel to flow over said coated scored region; maintaining said temperature for a sufficient time to allow said sol-gel to flow and fill any imperfections in said coated scored region; and cooling said glass sheet.
Claim 21
Independent Claim
98 words
A method of heat treating a glass sheet having a scored region comprising the steps of: coating said scored region with a sol-gel composition comprised essentially of boron and silica compositions and having a viscosity lower than that of said glass sheet; heating said glass sheet to a temperature above its strain point and below its melting point and sufficient to cause said sol-gel to flow over said coated scored region; maintaining said temperature for a sufficient time to allow said sol-gel to flow and fill any imperfections in said coated scored region; and cooling said glass sheet.
Claim 22
Dependent Claim
30 words
A method according to claim 14, wherein said sol-gel has a molar ratio of 55 to 80 percent SiO 2 and 20 to 45 percent B 2 O 3 .
Claim 23
Dependent Claim
35 words
A tempered glass article comprising a glass sheet having at least one hole extending entirely through its thickness, and a sol-gel coating essentially containing silica and boron compositions bonded to the wall of said hole.
Claim 24
Dependent Claim
35 words
A tempered glass article comprising a glass sheet having at least one hole extending entirely through its thickness, and a sol-gel coating essentially containing silica and boron compositions bonded to the wall of said hole.
Claim 25
Dependent Claim
28 words
A tempered glass article according to claim 16, wherein said coating comprises 55 to 80 percent SiO 2 and 20 to 45 percent B 2 O 3 .
Claim 26
Dependent Claim
27 words
A tempered glass article according to claim 17, wherein said coating comprises SiO 2 and B 2 O 3 in a molar ratio of 75 to 25.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-24 | 1992-10-24 | 1993-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-24 | 1996-10-24 | 1997-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-24 | 2000-10-24 | 2001-04-25 | $7700.00 | Window Closed / Lapsed |