Method for producing a ceramizable green glass component, and ceramizable green glass component, and glass ceramic article

Patent metadata

Field	Value
Publication number	US-2016122226-A1
Application number	US-201514926570-A
Country	US
Kind code	A1
Filing date	Oct 29, 2015
Priority date	Oct 29, 2014
Publication date	May 5, 2016
Grant date	—

Abstract

A method for producing ceramizable green glass components provided, as well as apparatus for performing such method and ceramizable green glass components producible by such method. The method is a redrawing process in which a preform is heated, in a deformation zone, to a temperature that enables redrawing of the glass. The deformation zone is particularly small, which permits redrawing of the ceramizable green glass bodies while avoiding ceramization during the redrawing. The method provides plate-like or sheet-like green glass components that have a particularly smooth surface.

First claim

What is claimed is:

1 . A method for producing a glass ceramic article, comprising the steps of:
preparing a glass melt of ceramizable glass; producing, from the glass melt, a ceramizable green glass body as a preform, wherein the preform is substantially unceramized; providing the preform to a redrawing apparatus; heating at least a portion of the preform; redrawing the preform into a ceramizable green glass component, wherein the ceramizable green glass component has a crystalline content of less than 20 vol %.

2 . The method as claimed in claim 1 , wherein the crystalline content is less than 10 vol %.

3 . The method as claimed in claim 1 , wherein the ceramizable green glass component has a crystalline content of less than 2.5 vol %.

4 . The method as claimed in claim 1 , wherein the preform has a plate-like or sheet-like shape with a thickness D, a width B, and a length L, and wherein the green glass component has a plate-like or sheet-like or strip-like shape with a thickness d, a width b, and a length l, and wherein a width-to-thickness ratio changes due to the redrawing.

5 . The method as claimed in claim 4 , wherein the redrawing develops a deformation zone that has a height H of not more than 50*D, the deformation zone being a portion of the preform having a thickness between 0.95*D and 1.05*d.

6 . The method as claimed in claim 5 , wherein the height H is not more than 6*D.

7 . The method as claimed in claim 5 , wherein the redrawing comprises:
advancing the preform at a constant velocity v 1 ; withdrawing the ceramizable green glass component at a constant velocity v 2 ; and maintaining a dwell time of the preform in the deformation zone of less than 10 minutes.

8 . The method as claimed in claim 7 , wherein the dwell time is less than 30 seconds.

9 . The method as claimed in claim 7 , wherein the redrawing comprises:
maintaining a predetermined glass volume of the preform at a temperature above the temperature critical for crystallization for a time of not more than 5 seconds.

10 . The method as claimed in claim 5 , further comprising:
heating the preform to a first temperature below a crystallization temperature and below a softening point of the green glass; and heating the preform to a second temperature above the softening point in the deformation zone.

11 . The method as claimed in claim 1 , wherein the ceramizable glass is selected from the group consisting of barium titanate glass ceramics, lithium aluminum silicate glass ceramics, lithium silicate glass ceramics, magnesium aluminosilicate glass ceramics, zinc aluminosilicate glass ceramics, magnesium silicate glass ceramics, sodium aluminosilicate glass ceramics, potassium aluminosilicate glass ceramics, phosphate glass ceramics, and calcium aluminosilicate glass ceramics.

12 . The method as claimed in claim 1 , wherein the ceramizable glass comprises a composition, in mol %:
SiO 2 5-20; Al 2 O 3 4-15; B 2 O 3 0-5; BaO 20-45; TiO 2 20-60; CaO 0-5; SrO 0-10; CeO 2 0-5; ZrO 2 0-10; La 2 O 3 0-40; MnO 2 0-5; Y 2 O 3 0-5; Nb 2 O 3 0-30; and others <10.

13 . The method as claimed in claim 1 , wherein the ceramizable glass comprises a composition, in mol %:
Al 2 O 3 3-12; BaO 30-45; B 2 O 3 0-5; La 2 O 3 0-5; CeO 2 0-5; SiO 2 5-25; TiO 2 25-42; CaO 0-5; ΣAl 2 O 3 +B 2 O 3 +SiO 2 +P 2 O 5 15-30; ΣTiO 2 +ZrO 2 +Nb 2 O 3 +V 2 O 5 +HfO 2 +Sc 2 O 3 20-50; ΣBaO+CaO+SrO+CeO 2 +RE 2 O 3 30-50; and others <5.

14 . The method as claimed in claim 1 , wherein the ceramizable glass comprises a composition, in mol %:
Al 2 O 3 5-15; BaO 20-30; La 2 O 3 0-10; CeO 2 0-2; SiO 2 5-20; TiO 2 40-60; ZrO 2 5-10; Others: <5; ΣAl 2 O 3 +B 2 O 3 +SiO 2 +P 2 O 5 15-30; ΣTiO 2 +ZrO 2 +Nb 2 O 3 +V 2 O 5 +HfO 2 +Sc 2 O 3 30-55; and ΣBaO+CaO+SrO+CeO 2 +RE 2 O 3 25-40, wherein RE is one or more rare earth elements having atomic numbers selected from the group consisting of 39 and from 57 to 71.

15 . The method as claimed in claim 1 , wherein the ceramizable glass comprises the following components, in % of cations:

Si 4+
45 to 65;

Crystal agonists

Li +
25 to 40;

K +
0 to 8;

Na +
0 to 8;

Crystal antagonists

B 3+
0 to 5;

Al 3+
 0 to 10;

Zn 2+
0 to 4;

Nucleating agents

Ce 3+ /Ce 4+
>0 to 0.3; and

Ag +
 >0 to 0.5.

16 . The method as claimed in claim 1 , wherein the ceramizable green glass component comprises a thickness d of less than 2000 μm.

17 . The method as claimed in claim 1 , wherein the ceramizable green glass component comprises a thickness d of less than less than 10 μm.

18 . The method as claimed in claim 1 , wherein the ceramizable green glass component comprises a thickness-to-width ratio d/b of not more than 1:200.

19 . The method as claimed in claim 1 , wherein the ceramizable green glass component comprises a thickness-to-width ratio d/b of not more than 1:200,000.

20 . The method as claimed in claim 1 , wherein the ceramizable green glass component comprises a surface having at least one section with a fire-polished surface quality of R a ≦20 nm.

21 . The method of claim 1 , further comprising subjecting the ceramizable green glass component to a ceramization process, with or without intermediate processing, after having been cooled to less than 300° C., wherein during the ceramization process the ceramizable green glass component is reheated and ceramized to produce the glass ceramic article.

22 . The method of claim 21 , wherein

Assignees

• Schott Ag

Inventors

• Hunzinger Bernhard
• Moseler Doris
• Büllesfeld Frank
• Lange Ulrich

Classifications

• C03C3/127

  containing TiO2 as glass former · CPC title

• C03B23/037 Primary

  by drawing · CPC title

• C03C3/095

  containing rare earths · CPC title

• C03B32/02

  Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles {(C03B27/012 takes precedence)} · CPC title

• C03B23/047

  by drawing ({C03B23/091} , C03B37/025 takes precedence) · CPC title