Laminated glass article with ion exchangeable core and clad layers having diffusivity contrast and method of making the same

Patent metadata

Field	Value
Publication number	US-2022009204-A1
Application number	US-202117485976-A
Country	US
Kind code	A1
Filing date	Sep 27, 2021
Priority date	Aug 28, 2014
Publication date	Jan 13, 2022
Grant date	—

Abstract

A laminated glass article has a first layer having a first ion exchange diffusivity, D 0 , and a second layer adjacent to the first layer and having a second ion exchange diffusivity, D 1 . D 0 /D 1 is from about 1.2 to about 10, or D 0 /D 1 is from about 0.05 to about 0.95. A method for manufacturing the laminated glass article includes forming a first layer having a first ion exchange diffusivity, D 0 , and forming a second layer adjacent to the first layer and having a second ion exchange diffusivity, D 1 . The laminated glass article can be strengthened by an ion exchange process to form a strengthened laminated glass article having a compressive stress layer with a depth of layer from about 8 μm to about 100 μm.

First claim

What is claimed is:

1 . A method for manufacturing a laminated glass article, comprising:
selecting a first layer based on a first ion exchange diffusivity (D 0 ) of the first layer; selecting a second layer based on a second ion exchange diffusivity (D 1 ) of the second layer, the first and second layers selected such that D 0 /D 1 is from about 1.2 to about 10; and forming the first and second layers adjacent to one another.

2 . The method of claim 1 , wherein the first layer is a core layer and the second layer is a clad layer.

3 . The method of claim 1 , wherein the first layer is a first clad layer and the second layer is a second clad layer.

4 . The method of claim 1 , further comprising strengthening the laminated glass article by an ion exchange process to form a strengthened laminated glass article having a compressive stress layer with a depth of layer from about 8 μm to about 150 μm.

5 . The method of claim 4 , wherein the depth of layer is from about 50 μm to about 150 μm.

6 . The method of claim 4 , wherein the compressive stress layer has a maximum compressive stress from about 300 MPa to about 1000 MPa.

7 . The method of claim 4 , wherein the strengthening the laminated glass article comprises immersing the laminated glass article in a substantially pure molten KNO 3 bath for a duration from about 2 hours to about 16 hours at a temperature from about 370° C. to about 530° C.

8 . The method of claim 7 , wherein the strengthening the laminated glass article comprises immersing the laminated glass article in a second molten KNO 3 bath having an effective mole fraction of K + of less than about 90% for a duration of about 0.2 hours to about 1 hour at a temperature of about 400° C.

9 . The method of claim 1 , wherein a thickness of the laminated glass article is from about 0.075 mm to about 4 mm.

10 . The method of claim 9 , wherein the thickness of the laminated glass article is from about 0.3 mm to about 2 mm.

11 . The method of claim 1 , wherein a thickness of the second layer is from about 3 μm to about 100 μm.

12 . The method of claim 11 , wherein a thickness of the second layer is from about 5 μm to about 50 μm.

13 . The method of claim 1 , wherein a central tension of the laminated glass article is less than a threshold central tension (TCT) calculated using formula (2):
TCT(MPa)=−38.7(MPa/mm)·ln( t )(mm)+48.2(MPa)   [Formula 2],
wherein t represents a thickness of the laminated glass article.

14 . The method of claim 1 , wherein
D 0 /D 1 is from about 5 to about 10, the depth of layer is from about 8 μm to about 80 μm, a maximum compressive stress in a compressive stress layer of the laminated glass article is from about 500 MPa to about 900 MPa, and a central tension of the laminated glass article is less than a threshold central tension (TCT) calculated using formula (2):
TCT(MPa)=−38.7(MPa/mm)·ln( t )(mm)+48.2(MPa)   [Formula 2],

wherein t represents the thickness of the laminated glass article.

Assignees

• Corning Inc

Inventors

• Peng Gaozhu
• Zhou Chunfeng

Classifications

• B32B17/10045

  with at least one intermediate layer consisting of a glass sheet · CPC title

• C03B17/02

  Forming {molten} glass coated with coloured layers; {Forming molten glass of different compositions or layers; Forming molten glass comprising reinforcements or inserts} · CPC title

• C03C21/002

  to perform ion-exchange between alkali ions (C03C21/005 takes precedence) · CPC title

• C03B27/03 Primary

  the liquid being a molten metal or a molten salt · CPC title

• B32B17/10119

  having a composition deviating from the basic composition of soda-lime glass, e.g. borosilicate · CPC title