Shaped glass laminates and methods for forming the same

Patent metadata

Field	Value
Publication number	US-10954154-B2
Application number	US-201815899689-A
Country	US
Kind code	B2
Filing date	Feb 20, 2018
Priority date	Feb 20, 2017
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

Embodiments of a laminate including a first curved glass substrate comprising a first viscosity (poises) at a temperature of 630° C.; a second curved glass substrate comprising a second viscosity that is greater than the first viscosity at a temperature of 630° C.; and an interlayer disposed between the first curved glass substrate and the second curved glass substrate, are disclosed. In one or more embodiments, the first curved glass substrate exhibits a first sag depth that is within 10% of a second sag depth of the second curved glass substrate. In one or more embodiments, the first glass substrate and the second glass substrate exhibit a shape deviation therebetween of about ±5 mm or less as measured by an optical three-dimensional scanner or exhibit minimal optical distortion. Embodiments of vehicles including such laminates and methods for making such laminates are also disclosed.

First claim

What is claimed is:

1. A laminate comprising:
a first curved glass substrate comprising a first major surface, a second major surface opposing the first major surface, a first thickness defined as a distance between the first major surface and the second major surface, a first sag depth of about 2 mm or greater, and the first curved glass substrate comprising a first viscosity;
a second curved glass substrate comprising a third major surface, a fourth major surface opposing the third major surface, a second thickness defined as a distance between the third major surface and the fourth major surface, a second sag depth of about 2 mm or greater, and the second curved glass substrate comprising a second viscosity that is greater than the first viscosity at a temperature of 630° C.; and
an interlayer disposed between the first curved glass substrate and the second curved glass substrate and adjacent the second major surface and the third major surface,
wherein the first sag depth is within 10% of the second sag depth and a shape deviation between the first glass substrate and the second glass substrate is ±5 mm or less as measured by an optical three-dimensional scanner,
wherein the laminate comprises an effective viscosity that is between the first viscosity and the second viscosity at a temperature (T) in a range from about 500° C. to about 700° C., and is determined by the equation: μeff(T)=((μ1(T)t1)/(t1+t2))+((μ2(T)t2)/(t1+t2)), where μ1(T) is the viscosity of the first curved glass substrate at temperature (T), t1 is the thickness of the first curved glass substrate, μ2(T) is the viscosity of the second curved glass substrate at temperature (T), t2 is the thickness of the second curved glass substrate,
wherein one of or both the first major surface or the fourth major surface exhibits an optical distortion of less than 200 millidiopters as measured by an optical distortion detector using transmission optics according to ASTM 1561, and
wherein the first major surface or the second major surface comprises a membrane tensile stress of less than 7 MPa as measured by a surface stressmeter, according to ASTM C1279.

2. The laminate of claim 1 , wherein, at a temperature of about 630° C., the second viscosity is in a range from about 10 times the first viscosity to about 750 times the first viscosity.

3. The laminate of claim 1 , wherein the second thickness is less than the first thickness.

4. The laminate of claim 1 , wherein the first curved glass substrate comprises a first sag temperature and the second curved glass substrate comprises a second sag temperature that differs from the first sag temperature and wherein a difference between the first sag temperature and the second sag temperature is in a range from about 30° C. to about 150° C.

5. The laminate of claim 1 , wherein the second sag depth is in a range from about 5 mm to about 30 mm.

6. The laminate of claim 1 , wherein the laminate is substantially free of visual distortion as measured by ASTM C1652/C1652M.

7. The laminate of claim 1 , wherein one of or both the first curved glass substrate or the second curved glass substrate comprises a compressive stress region and a central tension region formed by a coefficient of thermal expansion difference between portions of the corresponding curved glass substrate that mechanically strengthens the corresponding curved glass substrate.

8. A vehicle comprising:
a body defining an interior and an opening in communication with the interior;
a complexly-curved laminate disposed in the opening, the complexly-curved laminate comprising:
a first curved glass substrate comprising a first major surface, a second major surface opposing the first major surface, a first thickness defined as a distance between the first major surface and the second major surface, and a first sag depth of about 2 mm or greater, the first curved glass substrate comprising a first viscosity;
a second curved glass substrate comprising a third major surface, a fourth major surface opposing the third major surface, a second thickness defined as a distance between the third major surface and the fourth major surface, a second sag depth of about 2 mm or greater, and the second curved glass substrate comprising a second viscosity that is greater than the first viscosity at a temperature of about 630° C.; and
an interlayer disposed between the first curved glass substrate and the second curved glass substrate and adjacent the second major surface and the third major surface,
wherein the first sag depth is within 10% of the second sag depth and a shape deviation between the first curved glass substrate and the second curved glass substrate is ±5 mm or less as measured by an optical three-dimensional scanner,
wherein the laminate comprises an effective viscosity that is between the first viscosity and the second viscosity at a temperature (T) in a range from about 500° C. to about 700° C., and is determined by the equation: μeff(T)=((μ1(T)t1)/(t1+t2))+((μ2(T)t2)/(t1+t2)), where μ1(T) is the viscosity of the first curved glass substrate at temperature (T), t1 is the thickness of the first curved glass substrate, μ2(T) is the viscosity of the second curved glass substrate at temperature (T), t2 is the thickness of the second curved glass substrate,
wherein one of or both the first major surface or the fourth major surface exhibits an optical distortion of less than 200 millidiopters as measured by an optical distortion detector using transmission optics according to ASTM 1561, and
wherein the first major surface or the second major surface comprises a membrane tensile stress of less than 7 MPa as measured by a surface stressmeter, according to ASTM C1279.

9. The vehicle of claim 8 , wherein, at a temperature of 630° C., the second viscosity is in a range from about 10 times the first viscosity to about 750 times the first viscosity.

10. The vehicle of claim 8 , wherein the second thickness is less than the first thickness.

11. The vehicle of claim 8 , wherein the first curved glass substrate comprises a first sag temperature and the second curved glass substrate comprises a second sag temperature that differs from the first sag temperature.

12. The vehicle of claim 8 , wherein the laminate is substantially free of visual distortion as measured by ASTM C1652/C1652M.

13. The laminate of claim 8 , wherein one of or both the first curved glass substrate or the second curved glass substrate comprises a compressive stress region and a central tension region formed by a coefficient of thermal expansion difference between portions of the corresponding curved glass substrate that mechanically strengthens the corresponding curved glass substrate.

14. A method of forming the curved laminate of claim 1 , the method comprising:
forming a stack comprising a first glass substrate and a second glass substrate, the first glass substrate comprising the first viscosity and a first sag temperature, the second glass substrate comprising the second viscosity greater than the first viscosity at a temperature of 630° C. and a second sag temperature that differs from the first sag temperature; and
heating the stack and co-shaping the stack to form a co-shaped stack, the co-shaped stack comprising the first curved glass substrate having the first sag depth and the second curved glass substrate having the second sag depth, the first curved glass substrate formed from the first glass substrate, and the second curved glass substrate formed from the second glass substrate.

15. The method of claim 14 , wherein one of or both the first curved glass substrate or the second curved gla

Assignees

• Corning Inc

Inventors

• Fredholm Michele Marie-Louise

Classifications

• C03C3/087

  containing calcium oxide, e.g. common sheet or container glass · CPC title

• C03B23/0357

  by suction without blowing, e.g. with vacuum or by venturi effect · CPC title

• C03B23/0252 Primary

  by gravity only, e.g. sagging (C03B23/035 takes precedence) · CPC title

• B60J1/008

  of special shape, e.g. beveled edges, holes for attachment, bent windows, peculiar curvatures such as when being integrally formed with roof, door, etc. · CPC title

• B32B2250/40

  Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA · CPC title