Substrate provided with a coating based on a glass flux, glass flux material, and method for coating a glass or glass ceramic substrate

Abstract

A glass flux material for applying an opaque coating is provided. The glass flux material includes at least one pigment and a glass component with the following composition: SiO.sub.2 55-70 mol %, Al.sub.2O.sub.3 2.5-8 mol %, Bi.sub.2O.sub.3 0.5-<4 mol %, B.sub.2O.sub.3 14-27 mol %, with at least 2.5 mol % of at least one oxide of the group Li.sub.2O, Na.sub.2O, and K.sub.2O, wherein the ratio of alkali oxides to aluminum oxide ?R.sub.2O/Al.sub.2O.sub.3 is less than 6.

Claims

1. A coated glass substrate, comprising: a glass substrate having a coefficient of linear thermal expansion ? at 20? C. to 300? C. of up to 5.5*10.sup.?6; and an opaque coating applied to the glass substrate as a glass flux material, the glass flux material including at least one pigment and a glass component, the glass component comprising: SiO.sub.2 58-65 mol %, Al.sub.2O.sub.3 2.5-3.6 mol %, Bi.sub.2O.sub.3 0.5-2 mol %, and B.sub.2O.sub.3 18-25 mol %, with at least 2.5 mol % of at least one oxide of the group Li.sub.2O, Na.sub.2O and K.sub.2O, and a ratio of alkali oxides to aluminum oxide ?R.sub.2O/Al.sub.2O.sub.3 that is greater than 2.1 and less than 6, wherein the glass component has a softening temperature of less than 680? C.

2. The coated glass or glass ceramic substrate as claimed in claim 1, wherein the ratio of alkali oxides to aluminum oxide ?R.sub.2O/Al.sub.2O.sub.3 is greater than 2.1 and less than 4.5.

3. The coated glass or glass ceramic substrate as claimed in claim 1, wherein the glass component comprises: Li.sub.2O 0-15 mol %, Na.sub.2O 0-12 mol %, and K.sub.2O 0-4 mol %.

4. The coated glass or glass ceramic substrate as claimed in claim 1, wherein the glass component further comprises at least one material selected from the group consisting of up to 2 mol % of ZrO.sub.2, up to 2 mol % of TiO.sub.2, up to 3 mol % of alkaline earth metal oxides, up to 3 mol % of ZnO, and combinations thereof.

5. The coated glass or glass ceramic substrate as claimed in claim 1, wherein the glass flux material is provided in form of a paste including a ground glass component, wherein the ground glass component has a particle size distribution with d.sub.50 between 1.2 and 2.5 ?m.

6. The coated glass or glass ceramic substrate as claimed in claim 1, wherein the opaque coating has a thickness of more than 4 ?m.

7. The coated glass or glass ceramic substrate as claimed in claim 1, wherein the coated glass substrate is employed for a use selected from the group consisting of a bullet-proof glass laminate composite, a fireplace window, a pyrolysis oven window, a fire protection glazing, a lamp, and a pharmaceutical packaging.

8. The coated glass or glass ceramic substrate as claimed in claim 1, wherein the glass component comprises at least 2.5 mol % of Li.sub.2O.

9. The coated glass or glass ceramic substrate as claimed in claim 1, wherein the ?R.sub.2O is at least 8 mol %.

10. The coated glass or glass ceramic substrate as claimed in claim 9, wherein the ?R.sub.2O is less than 18 mol %.

11. The coated glass or glass ceramic substrate as claimed in claim 1, wherein the glass flux-based coating has, in L*a*b* color space, an L* value of more than 86 or less than 27, and an a* value of less than 0.05, and a b* value of less than 0.05.

12. The coated glass or glass ceramic substrate as claimed in claim 1, wherein the glass flux-based coating is lead free.

13. A glass flux material for applying an opaque coating, comprising: a paste of at least one pigment and a glass component, the glass component comprising: SiO.sub.2 58-65 mol %, Al.sub.2O.sub.3 2.5-3.6 mol %, Bi.sub.2O.sub.3 0.5-2 mol %, and B.sub.2O.sub.3 18-25 mol %, with at least 2.5 mol % of at least one oxide of the group Li.sub.2O, Na.sub.2O, and K.sub.2O, and a ratio of alkali oxides to aluminum oxide ?R.sub.2O/Al.sub.2O.sub.3 that is greater than 2.1 and less than 6, wherein the glass component is ground and has a particle size distribution with a d50 between 1.2 and 2.5 mm, and wherein the glass component has a softening temperature of less than 680? C.

14. The glass flux material as claimed in claim 13, wherein the glass component comprises at least 2.5 mol % of Li.sub.2O.

15. A coated glass c, comprising: a glass substrate having a coefficient of linear thermal expansion ? at 20? C. to 300? C. of up to 5.5*10.sup.?6/K; and a glass flux-based coating having a coefficient of linear thermal expansion ? at 20? C. to 300? C. of less than 7*10.sup.?6/K, wherein the glass flux-based coating comprises at least one pigment and a glass component, the glass component comprising at least 2.5 mol % of Li.sub.2O, 2.5 to 3.6 mol % of Al.sub.2O.sub.3, 18 to 25 mol % of B.sub.2O.sub.3, and a ratio of alkali oxides to aluminum oxide ?R.sub.2O/Al.sub.2O.sub.3 that is greater than 2.1 and less than 6, and wherein the glass flux-based coating exhibits a transmittance of less than 1% in a wavelength range from 380 to 780 nm.

16. The coated glass or glass ceramic substrate as claimed in claim 15, wherein the transmittance of the glass flux-based coating is less than 0.5%.

17. The coated glass or glass ceramic substrate as claimed in claim 15, wherein the glass flux-based coating comprises pigments with a degree of volume filling from 10 to 60%.

18. The coated glass or glass ceramic substrate as claimed in claim 15, wherein the substrate is curved, at least in portions thereof.

19. The coated glass or glass ceramic substrate as claimed in claim 15, wherein the substrate is a multilayer composite.

20. The coated glass or glass ceramic substrate as claimed in claim 15, wherein the glass flux-based coating has a thickness of more than 5 ?m.

21. The coated glass or glass ceramic substrate as claimed in claim 15, wherein the glass flux-based coating has, in L*a*b* color space, an L* value of more than 86 or less than 28.

22. The coated glass or glass ceramic substrate as claimed in claim 15, wherein the glass flux-based coating has, in L*a*b* color space, an a* value and a b* value of less than 1.

23. A coated glass substrate, comprising: a glass substrate having a coefficient of linear thermal expansion ? at 20? C. to 300? C. of up to 5.5*10.sup.31 6/K; and an opaque coating applied to the glass substrate as a glass flux material, the glass flux material including at least one pigment and a glass component, the glass component comprising: SiO.sub.2 58-65 mol %, Al.sub.2O.sub.3 2.5-3.6 mol %, Bi.sub.2O.sub.3 0.5-2 mol %, B.sub.2O.sub.3 18-25 mol %, and at least 2.5 mol % of an alkali oxide selected from the group consisting of Li.sub.2O, Na.sub.2O, K.sub.2O, and any combinations thereof, wherein the glass component comprises a ratio of the alkali oxide to aluminum oxide that is greater than 2.1 and less than 6, and the glass component comprises a sum of alkali oxides that is at least 8 mol %.

24. The glass flux material as claimed in claim 23, wherein the substrate is made of borosilicate glass.

25. A glass flux material for applying an opaque coating, comprising: a paste of at least one pigment and a glass component, the glass component comprising: SiO.sub.2 58-65 mol %, Al.sub.2O.sub.3 2.5-3.6 mol %, Bi.sub.2O.sub.3 0.5-2 mol %, B.sub.2O.sub.3 18-25 mol %, and with at least 2.5 mol % of at least one oxide of the group Li.sub.2O, Na.sub.2O, and K.sub.2O, and a ratio of alkali oxides to aluminum oxide ?R.sub.2O/Al.sub.2O.sub.3 that is greater than 2.1 and less than 6, wherein the glass component is ground and has a particle size distribution with a d50 between 1.2 and 2.5 ?m, and wherein Na.sub.2O is present in an amount that is less than 5 mol % and/or in an amount that is less than an amount of Al.sub.2O.sub.3.

26. The glass flux material as claimed in claim 25, wherein Na.sub.2O is less than or equal to 1.3 mol %.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 schematically shows a glass substrate of the present disclosure;

(2) FIG. 2 shows the transmission behavior of different coatings.

(3) FIG. 3 is a schematic view of a bullet-proof security glazing of the present disclosure.

(4) FIG. 4 is a schematic sectional view of the sheet illustrated in FIG. 3.

(5) FIG. 5 shows a pharmaceutical packaging having the coating of the invention.

DETAILED DESCRIPTION

(6) FIG. 1 schematically shows a glass substrate 1 made of a borosilicate glass which is provided with a coating 2 in a peripheral area thereof, which visually gives the impression of a frame.

(7) It will be understood that the coating according to the invention is likewise suitable for applying scales, a zone boundary of a cooktop zone, and for applying labels, for example.

(8) FIG. 2 shows the transmission behavior of different coatings.

(9) On the x-axis the wavelength is plotted, and on the y-axis transmittance in percent.

(10) Curve 3 represents the transmittance profile of a commercially available single layer enamel. This is a glaze comprising a glass frit with a high proportion of bismuth oxide and pigments including Cr and Cu components.

(11) It can be seen that for a wavelength range starting at about 450 ?m and above, transmittance is greater than 1% and increases to 2%. Therefore, the coating is not opaque.

(12) Curve 4 represents the coating produced from Example 2 and curve 5 from Example 3 of Table 1 and fired.

(13) As can be seen, for both coatings transmittance is well below 0.5% over the entire range of wavelengths of visible light.

(14) Thus, the coating is opaque.

(15) The invention permits to provide an easily appliable, cost-efficient and opaque enamel coating for glasses having a low thermal expansion coefficient.

(16) FIG. 3 is a schematic view of a bullet-proof security glazing which comprises a substrate 1 consisting of a plurality of glass and/or glass ceramic layers and polymer layers which are laminated to form a composite.

(17) At the peripheral area, the sheet is provided with an opaque coating 2 that forms a frame which covers adhesive seams, for example.

(18) FIG. 4 is a schematic sectional view of the sheet illustrated in FIG. 3. As can be seen, the outer layers of the composite are projecting, and the opaque coating 2 is partially deposited between the panes of the composite and partially on the underside of the composite.

(19) The coating material of the invention exhibits high scratch resistance and does not discolor during autoclaving of the laminate.

(20) FIG. 5 shows a pharmaceutical packaging 6 in the form of a glass ampoule. In this case, the coating of the invention can be used, for example, to apply the mark 7 or a label 8.