# US 2019/0315652 A1 · Transparent, dyed cook top or hob with improved colored display capability and a method for the manufacturing of such a cook top or hob

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- Number: US 2019/0315652 A1
- Document ID: US20190315652A1
- Status: Published application
- Kind: A1
- Application number: 16/431,133
- Filed: 2019-06-04
- Published: 2019-10-17
- Earliest claimed: 2008-10-07
- Assignees: Schott AG
- Applicants: Schott AG
- Inventors: Friedrich SIEBERS; Ulrich SCHIFFNER; Wolfgang SCHMIDBAUER; Klaus SCHOENBERGER
- Web page: https://patentgrep.com/patent/US20190315652A1

## CPC

- C03C 10/0027: {containing SiO2, Al2O3, Li2O as main constituents}
- 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)
- C03C 3/087: containing calcium oxide, e.g. common sheet or container glass
- C03C 3/095: containing rare earths
- C03C 3/097: containing phosphorus, niobium or tantalum
- C03C 8/02: Frit compositions, i.e. in a powdered or comminuted form
- C03C 8/04: containing zinc
- C03C 10/0009: {containing silica as main constituent}
- F24C 15/10: Tops, e.g. hot plates; Rings (cover lids or splash guards F24C15/12; spillage trays or grooves F24C15/14)
- H05B 3/74: Non-metallic plates {, e.g. vitroceramic, ceramic or glassceramic hobs, also including power or control circuits}
- C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03B: MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- F24C: DOMESTIC STOVES OR RANGES (exclusively for solid fuels F24B); DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
- H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL

## 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

### Claim 1

Transparent, dyed cook top or hob with improved color display capability, consisting of a glass-ceramic comprising high quartz mixed crystals as predominant crystal phase whereby the glass ceramic, except of some unavoidable traces, contains none of the chemical refining agents arsenic oxide and/or antimony, characterized by transmission values of greater than 0.1% within the entire wavelength range of visible light larger than 450 nm, a light transmission in the visible from 0.8 to 2.5% and a transmission in the infrared at 1600 nm of 45-85%, and wherein the glass ceramic comprises Fe2O3 and V2O5, wherein the Fe2O3 content is at least as high as the V2O5 content and thus meet the condition
<Fe2O3/V2O5<8.

### Claim 2 (depends on 1)

Cook top or hob according to claim 1, having 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 light transmission in the visible of 1.0-2.0%.

### Claim 3 (depends on 1)

Cook top or hob according to claim 1 having a maximum Fe2O3 content in the glass ceramic of 0.2 weight % and preferably 0.18 weight %.

### Claim 4 (depends on 1)

Cook top or hob according to claim 1 having a Fe2O3 content of 0.08 to 0.15 weight %.

### Claim 5 (depends on 1)

Cook top or hob according to claim 1 having a V2O5 content of 0.01 to 0.06 weight %.

### Claim 6 (depends on 1)

Cook top or hob according to claim 1 wherein the glass ceramic further comprises TiO2, ZrO2 and SnO2.

### Claim 7 (depends on 6)

Cook top or hob according to claim 6, wherein the SnO2 content is less than 0.6 weight % and/or the content of Fe2O3 is at least 20% of the SnO2 content.

### Claim 8 (depends on 1)

Cook top or hob according to claim 1, wherein the glass ceramic has a water content prior to ceramization of 0.003 to 0.005 mol.

### Claim 9 (depends on 1)

Cook top or hob according to claim 1, wherein the composition of the glass ceramic (in weight % on oxide basis) consists essentially of
Li2O
3.0-4.2
Σ Na2O + K2O
0.2-1.5
MgO
0-1.5
Σ CaO + SrO + BaO
0-4
ZnO
0-2
B2O3
0-2
Al2O3
19-23
SiO2
60-69
TiO2
2.5-4
ZrO2
0.5-2
P2O5
0-3
SnO2
0.1-<0.6
Σ TiO2 + ZrO2 + SnO2
3.8-6
V2O5
0.01-0.06
Fe2O3
0.03-0.2
and
<Fe2O3/V2O5<8.

### Claim 10 (depends on 1)

Cook top or hob according to claim 1, having a composition of the glass ceramic which in weight % on oxide basis contains
CaO
0.2-1
SrO
0.1-1.

### Claim 11 (depends on 1)

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

### Claim 12 (depends on 11)

Cook top or hob according to claim 11, wherein the equilibrium oxygen partial pressure is set by a temperature of the molten glass greater than 1700° C.

### Claim 13 (depends on 12)

Cook top or hob according to claim 12, having a V2O5 content of less than 0.04 weight %, preferably less than 0.03 weight %.

### Claim 14 (depends on 1)

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 selected from blue, green, yellow, orange and white are applied.

### Claim 15

Transparent, dyed cook top or hob with improved color display capability, consisting of a glass-ceramic comprising high quartz mixed crystals as predominant crystal phase whereby the glass ceramic, except of some unavoidable traces, contains none of the chemical refining agents arsenic oxide and/or antimony, characterized by transmission values of greater than 0.1% within the entire wavelength range of visible light larger than 450 nm, a light transmission in the visible from 0.8 to 2.5% and a transmission in the infrared at 1600 nm of 45-85%, and wherein the glass ceramic comprises Fe2O3 and V2O5, wherein the Fe2O3 content is 0.08 to 0.15 weight %.

### Claim 16 (depends on 15)

Cook top or hob according to claim 15, 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 light transmission in the visible of 1.0-2.0%.

### Claim 17 (depends on 15)

Cook top or hob according to claim 15, wherein the Fe2O3 content is at least as high as the V2O5 content and thus meets the condition
<Fe2O3/V2O5<8.

### Claim 18 (depends on 15)

Cook top or hob according to claim 15, characterized in that the glass ceramic further comprises V2O5, TiO2, ZrO2 and SnO2.

### Claim 19 (depends on 18)

Cook top or hob according to claim 18, having a V2O5 content of 0.01 to 0.06 weight %.

### Claim 20 (depends on 18)

Cook top or hob according to claim 18, wherein the SnO2 content is less than 0.6 weight % and/or the content of Fe2O3 is at least 20% of the SnO2 content.

### Claim 21 (depends on 15)

Cook top or hob according to claim 15, wherein the glass ceramic has a water content prior to ceramization of 0.003 to 0.005 mol.

### Claim 22

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 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%, and
wherein the glass ceramic comprises Fe2O3 and V2O5, wherein the Fe2O3 content is at least as high as the V2O5 content and thus meet the condition
<Fe2O3/V2O5<8.

### Claim 23 (depends on 22)

Cook top or hob according to claim 22, having a maximum Fe2O3 content in the glass ceramic of 0.2 weight % and preferably 0.18 weight %.

### Claim 24 (depends on 22)

Cook top or hob according to claim 22, having a Fe2O3 content of 0.08 to 0.15 weight %.

### Claim 25 (depends on 22)

Cook top or hob according to claim 22, characterized by a V2O5 content of 0.01 to 0.06 weight %.

### Claim 26 (depends on 22)

Cook top or hob according to claim 22, wherein the glass ceramic further comprises TiO2, ZrO2 and SnO2.

### Claim 27 (depends on 26)

Cook top or hob according to claim 26, wherein the SnO2 content is less than 0.6 weight % and/or the content of Fe2O3 is at least 20% of the SnO2 content.

### Claim 28 (depends on 22)

Cook top or hob according to claim 22, wherein the glass ceramic has a water content prior to ceramization of 0.003 to 0.005 mol.