Laminated glass article with ceramic phase and method of making the article

• US 10,357,945 B2
• Filed: 10/04/2013
• Issued: 07/23/2019
• Est. Priority Date: 10/04/2012
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Beall, George Halsey, Boek, Heather Debra, Venkataraman, Natesan
• Primary Examiner(s): Herring, Lisa L
• Application Number:
  US14/432,415
• Publication Number:
  US 20150251383A1
• Time in Patent Office: 2,118 Days
• Field of Search: None
• CPC Class Codes: B32B 17/06 comprising glass as the main or only constituent of a layer, next to another layer of a specific material
• CPC Class Codes: B32B 2307/558 Impact strength, toughness
• CPC Class Codes: B32B 2457/00 Electrical equipment
• CPC Class Codes: B32B 2457/12 Photovoltaic modules
• CPC Class Codes: B32B 2457/202 LCD, i.e. liquid crystal displays
• CPC Class Codes: B32B 2457/208 Touch screens
• CPC Class Codes: B32B 37/15 with at least one layer being manufactured and immediately laminated before reaching its stable state, e.g. in which a layer is extruded and laminated while in semi-molten state
• CPC Class Codes: B32B 38/0036 Heat treatment for heating or cooling of layers during lamination B32B37/06, B32B37/08
• CPC Class Codes: C03B 17/02 Forming molten glass coated with coloured layers; Forming molten glass of different compositions or layers; Forming molten glass comprising reinforcements or inserts
• CPC Class Codes: C03B 17/064 by the overflow downdraw fusion process; Isopipes therefor
• CPC Class Codes: C03B 17/067 combined with thermal conditioning of the sheets
• CPC Class Codes: C03B 27/012 by heat treatment, e.g. for crystallisation; Heat treatment of glass products before tempering by cooling C03B27/008, C03B27/016 take precedence
• CPC Class Codes: C03B 32/02 Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles C03B27/012 takes precedence
• CPC Class Codes: C03C 10/00 Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition
• CPC Class Codes: C03C 10/0027 containing SiO2, Al2O3, Li2O as main constituents
• CPC Class Codes: C03C 21/002 to perform ion-exchange between alkali ions C03C21/005 takes precedence
• CPC Class Codes: C03C 21/008 in solid phase, e.g. using pastes, powders

Abstract

A method for forming a laminated glass article with a ceramic phase, such as a beta-spodumene phase, located at least at the junctures between a glass core and directly adjacent glass clad layers, and in some embodiments located throughout the laminated glass article. In some embodiments, a method is disclosed herein for forming a beta-spodumene glass-ceramic sheet, or a laminated glass article having a ceramic phase, or a laminated glass article having a beta-spodumene glass-ceramic, is disclosed.

Claims

1. A method for forming a laminated glass article having a ceramic phase, the method comprising:

forming, via fusion draw, a laminate glass sheet having cladding layers formed from a first glass composition rich in a first alkali and a core layer formed from a second glass composition rich in a second alkali, wherein the first alkali is lithium and the second alkali is sodium and the laminate glass sheet comprises diffusive glass layers disposed between the cladding layers and the core layer;

heat treating the laminate glass sheet to exchange ions of the first and second alkalis between the core and cladding layers; and

heat treating the laminate glass sheet a second time to nucleate and grow a ceramic phase in the laminate glass sheet after the heat treating the laminate glass sheet to exchange ions, wherein the ceramic phase is located only in the diffusive glass layers at junctures between the cladding layers and the core layer.

2. The method of claim 1 wherein the laminate glass sheet is heated sufficient to compressively stress at least one of the cladding layers.

3. The method of claim 1 wherein the ceramic phase is a beta-spodumene phase.

4. The method of claim 1 further comprising cutting the laminate glass sheet subsequent to the forming step and prior to the heat treating the laminate glass sheet to nucleate and grow a ceramic phase step.

5. A method for forming a laminated glass article having a ceramic phase, the method comprising:

forming, via fusion draw, a laminate glass sheet having cladding layers formed from a first glass composition rich in a first alkali and a core layer formed from a second glass composition rich in a second alkali, wherein the first alkali is lithium and the second alkali is sodium, the cladding layers have an average cladding coefficient of thermal expansion CTE_clad, the core layer has an average core coefficient of thermal expansion CTE_core, CTE_clad is less than CTE_core, and a differential between CTE_clad and CTE_core is less than 5×

10<sup>−

7</sup>/°

C.;

heat treating the laminate glass sheet to exchange ions of the first and second alkalis between the core and cladding layers; and

heat treating the laminate glass sheet a second time to nucleate and grow a ceramic phase in the laminate glass sheet after the heat treating the laminate glass sheet to exchange ions.

6. The method of claim 5 wherein the laminate glass sheet is heated sufficient to compressively stress at least one of the cladding layers.

7. The method of claim 5 wherein the ceramic phase is a beta-spodumene phase.