Transparent, dyed cook top or hob with improved colored display capability and a method for the manufacturing of such a cook top or hob

• US 10,562,807 B2
• Filed: 05/14/2015
• Issued: 02/18/2020
• Est. Priority Date: 10/07/2008
• Status: Active Grant

• Current Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Original Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Inventors: Siebers, Friedrich, Schiffner, Ulrich, Schmidbauer, Wolfgang, Schoenberger, Klaus
• Primary Examiner(s): Group, Karl E
• Application Number:
  US14/711,849
• Publication Number:
  US 20150239771A1
• Time in Patent Office: 1,741 Days
• 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: C03C 10/0009 containing silica as main constituent
• CPC Class Codes: C03C 10/0027 containing SiO2, Al2O3, Li2O as main constituents
• CPC Class Codes: C03C 3/087 containing calcium oxide, e.g. common sheet or container glass
• CPC Class Codes: C03C 3/095 containing rare earths
• CPC Class Codes: C03C 3/097 containing phosphorus, niobium or tantalum
• CPC Class Codes: C03C 8/02 Frit compositions, i.e. in a powdered or comminuted form
• CPC Class Codes: C03C 8/04 containing zinc
• CPC Class Codes: F24C 15/10 Tops, e.g. hot plates; Rings cover lids or splash guards F24C15/12; spillage trays or grooves F24C15/14
• CPC Class Codes: H05B 3/74 Non-metallic plates , e.g. vitroceramic, ceramic or glassceramic hobs, also including power or control circuits

Abstract

Transparent, dyed cook top or hob with improved color display capability, consisting of a glass ceramic with high quartz mixed crystals as predominant crystal phase, whereby the glass-ceramic contains none of the chemical refining agents arsenic oxide and/or antimony, with transmission values of greater than 0.1% in the range of the visible light within the entire wavelength range greater than 450 nm, a light transmission in the visible of 0.8-2.5% and a transmission in the infrared at 1600 nm of 45-85%.

Claims

1. A transparent, dyed cook top or hob with improved color display capability, comprising a glass-ceramic which comprises high quartz mixed crystals as predominant crystal phase whereby the glass ceramic, except as impurities present in amounts less than 500 ppm, contains none of the chemical refining agents arsenic oxide and/or antimony and has a water content prior to ceramization of 0.03 to 0.05 mol/l, and whereby the glass ceramic is characterized by transmission values of

>

0.15% at 450 nm

>

0.15% at 500 nm

>

0.25% at 550 nm

3-9% at 630 nm

50-80% at 1600 nm,

and a visible light transmission of 0.8 to 2.5%,

wherein the composition of the glass ceramic (in weight % on oxide basis) consists essentially of

2. The cook top or hob according to claim 1 characterized by a light transmission in the visible of 1.0-2.0%.

3. The cook top or hob according to claim 1 characterized by a composition of the glass ceramic which in weight % on oxide basis comprises

CaO 0.2-1

SrO 0.1-1.

4. The cook top or hob according to claim 1, having an equilibrium oxygen partial pressure pO₂ of the glass ceramic and/or crystallizable initial glasses of 1 bar at a temperature greater than 1580°

C.

5. The cook top or hob according to claim 4, characterized in that the equilibrium oxygen partial pressure is set by a temperature of the glass melt greater than 1700°

C.

6. The cook top or hob according to claim 4, characterized by a V₂O₅ content of less than 0.04 weight %.

7. The cook top or hob according to claim 1, characterized in that a temperature of the glass melt is greater than 1700°

C., a number of bubbles of less than 5 bubbles/kg of glass is achieved and the glass contains Fe₂O₃ and SnO₂, wherein the Fe₂O₃ content is at least 20 weight % of the SnO₂ content.

8. The cook top or hob according to claim 1, characterized in that instead of or in addition to red displays one or more other color displays are applied and are selected from the group consisting of blue, green, yellow, orange, white and combinations thereof.

9. A transparent, dyed cook top or hob with improved color display capability, comprising a glass-ceramic which comprises high quartz mixed crystals as predominant crystal phase whereby the glass ceramic, except as impurities present in amounts less than 500 ppm, contains none of the chemical refining agents arsenic oxide and/or antimony and has a water content prior to ceramization of 0.03 to 0.05 mol/l, and whereby the glass ceramic is characterized by transmission values of

>

0.15% at 450 nm

>

0.15% at 500 nm

>

0.25% at 550 nm

3-9% at 630 nm

50-80% at 1600 nm,

and a visible light transmission of 0.8 to 2.5%,

having a rapid ceramization ability of a crystallizable initial glass and a composition of the glass-ceramic which, in weight % based on oxide, consists essentially of;

10. The cook top or hob according to claim 9, having an equilibrium oxygen partial pressure pO₂ of the glass ceramic and/or crystallizable initial glasses of 1 bar at a temperature greater than 1580°

C.

11. The cook top or hob according to claim 10, characterized in that the equilibrium oxygen partial pressure is set by a temperature of the glass melt greater than 1700°

C.

12. The cook top or hob according to claim 10, characterized by a V₂O₅ content of less than 0.04 weight %.

13. The cook top or hob according to claim 9, characterized in that a temperature of the glass melt is greater than 1700°

C., a number of bubbles of less than 5 bubbles/kg of glass is achieved and the glass contains Fe₂O₃ and SnO₂, wherein the Fe₂O₃ content is at least 20 weight % of the SnO₂ content.

14. The cook top or hob according to claim 9 characterized in that instead of or in addition to red displays one or more other color displays are applied and are selected from the group consisting of blue, green, yellow, orange, white and combinations thereof.

15. The cook top or hob according to claim 9 characterized by a composition of the glass ceramic which in weight % on oxide basis comprises

CaO 0.2-1

SrO 0.1-1.

16. A transparent, dyed cook top or hob with improved color display capability, comprising a glass-ceramic which comprises high quartz mixed crystals as predominant crystal phase whereby the glass ceramic, except as impurities present in amounts less than 500 ppm, contains none of the chemical refining agents arsenic oxide and/or antimony and has a water content prior to ceramization of 0.03 to 0.05 mol/l, and whereby the glass ceramic is characterized by transmission values of

>

0.15% at 450 nm

>

0.15% at 500 nm

>

0.25% at 550 nm

3-9% at 630 nm

50-80% at 1600 nm,

and a visible light transmission of 0.8 to 2.5%,

having good meltability and devitrification resistance of a crystallizable initial glass with a working temperature V_A less than 1320°

C., an upper devitrification limit of at least 30°

C. below V_A and wherein the glass ceramic comprises in weight % on an oxide basis of;

17. The cook top or hob according to claim 16 having an equilibrium oxygen partial pressure pO₂ of the glass ceramic and/or crystallizable initial glasses of 1 bar at a temperature greater than 1580°

C.

18. The cook top or hob according to claim 17 characterized in that the equilibrium oxygen partial pressure is set by a temperature of the glass melt greater than 1700°

C.

19. The cook top or hob according to claim 18 characterized by a V₂O₅ content of less than 0.04 weight %.

20. The cook top or hob according to claim 17 characterized in that a temperature of the glass melt is greater than 1700°

C., a number of bubbles of less than 5 bubbles/kg of glass is achieved and the glass contains Fe₂O₃ and SnO₂, wherein the Fe₂O₃ content is at least 20 weight % of the SnO₂ content.

21. The cook top or hob according to claim 17 characterized in that instead of or in addition to red displays one or more other color displays are applied and are selected from the group consisting of blue, green, yellow, orange, white and combinations thereof.