Glass ceramic panel with a pleasing black decoration applied with a decorative paint
The black-colored glass ceramic panel has a cooking surface provided with a smooth black decoration by burning in a decorative paint, which contains a colorless zinc-containing glass flux and up to 10 wt. % of a partially coated pigment. The partially coated pigment consists of 20 to 40 wt. % of a black pigment with a grain size of at most 5μ and a grain size distribution characterized by a D 50 <2μ and 60 to 80% by weight of a zinc-free boro-alumino-silicate glass coating the black pigment. The glass flux consists, in wt. %, of Li 2 O, 0-5; Na 2 O, 0-5; K 2 O, <2; ΣLi 2 O+Na 2 O+K 2 O, 1-10; MgO, 0-3; CaO, 0-4; SrO, 0-4; BaO, 0-4; ZnO, >0-4; B 2 O 3 , 15-27; Al 2 O 3 , 10-20; SiO 2 , 43-58; TiO 2 , 0-3; ZrO 2 , Sb 2 O 3 , 0-2; F, 0-3.
1. A decorated glass ceramic panel with a cooking surface, said cooking surface being provided with a black decoration by means of a burned-in decorative paint, wherein said decorative paint is applied to said cooking surface to form said black decoration, said glass ceramic panel has a black color and said decorative paint on the cooking surface contains a colorless zinc-containing glass flux and at least one partially coated pigment;
wherein said at least one partially coated pigment consists of 20 to 40% by weight of a black pigment and 60 to 80% by weight of a zinc-free boro-alumino-silicate glass, said zinc-free boro-alumino-silicate glass coating said black pigment;
wherein said black pigment has a grain size of at most 5μ, and a grain size distribution characterized by a D 50 <2μ and consists of a Cr—Fe—Co—Mn spinel; and
wherein said colorless zinc-containing glass flux consists, in percent by weight, of:
Li 2 O
0-5
Na 2 O
0-5
K 2 O
<2
Σ Li 2 O + Na 2 O + K 2 O
1-10
MgO
0-3
CaO
0-4
SrO
0-4
BaO
0-4
ZnO
0-4
B 2 O 3
15-27
Al 2 O 3
10-20
SiO 2
43-58
TiO 2
0-3
ZrO 2
0-4
Sb 2 O 3
0-2
F
0-3;
wherein said decorative paint consists of said at least one partially coated pigment and said colorless zinc-containing glass flux; and
wherein said decorative paint contains said at least one partially coated pigment in an amount of from 9 to 10 percent by weight.
2. The glass ceramic panel as defined in claim 1 , which has a composition in percent by weight of:
Si 2 O
62-68
Al 2 O 3
19.5-22.5
Li 2 O
3.0-4.0
Na 2 O
0-1.0
K 2 O
0-1.0
BaO
1.5-3.5
CaO
0-1.0
MgO
0-0.5
ZnO
0.5-2.5
TiO 2
1.5-5.0
ZrO 2
0-3.0
MnO 2
0-0.40
Fe 2 O 3
0-0.20
CoO
0-0.30
NiO
0-0.30
V 2 O 5
0-0.80
Cr 2 O 3
0-0.20
F
0-0.20
Sb 2 O 3
0-2.0
As 2 O 3
0-2.0
ΣNa 2 O + K 2 O
0.5-1.5
ΣBaO + CaO
1.5-4.0
ΣTiO 2 + ZrO 2
3.5-5.5
ΣSb 2 O 3 + As 2 O 3
0.5-2.5.
3. The glass ceramic panel as defined in claim 1 , which has a composition in percent by weight of:
Li 2 O
2.5-5.5
Na 2 O
0-3.0
K 2 O
0-3.0
Σ Na 2 O + K 2 O
0-4.0
MgO
0-3.0
CaO
0-2.5
SrO
0-2.0
BaO
0-3.5
ZnO
0-3.5
Al 2 O 3
18-27
SiO 2
52-75
TiO 2
1.2-5.5
ZrO 2
0-3.0
SnO 2
<1.0
Σ TiO 2 + ZrO 2 + SnO 2
2.0-6.0
P 2 O 5
0-8.0
V 2 O 5
0.02-0.6,
and at least one coloring ingredient selected from the group consisting of Cr-, Mn-, Fe-, Co-, Ni-, Se- and Cl-compounds for adjustment and assisting in production of a black color shade.
4. The glass ceramic panel as defined in claim 1 , wherein said at least partially coated pigment comprises 70% by weight of said zinc-free boro-alumino-silicate coating glass and 30% by weight of said black pigment.
5. The glass ceramic panel as defined in claim 1 , wherein the decorative paint is applied in the form of a background texture as a decoration with a roughness R a ≦0.35μ.
6. The glass ceramic panel as defined in claim 1 , wherein said decorative paint has a layer thickness of from 1 to 7μ.
7. The decorated glass ceramic panel as defined in claim 1 , wherein said Cr—Fe—Co—Mn spinel contains 11% chromium (III), 15% Fe (II/III), 20% cobalt (II) and 20% Manganese (II/III) and is resistant to a temperature at which said decorative paint is burned in.
8. A decorated glass ceramic panel with a cooking surface, said cooking surface being provided with a black decoration by means of a burned-in decorative paint, wherein said decorative paint is applied to said cooking surface to form said black decoration, said glass ceramic panel has a black color and said decorative paint on the cooking surface contains 91 percent by weight of a colorless zinc-containing glass flux and 9 percent by weight of at least one partially coated pigment;
wherein said at least one partially coated pigment consists of 20 to 40% by weight of a black pigment and 60 to 80% by weight of a zinc-free boro-alumino-silicate glass, said zinc-free boro-alumino-silicate glass coating said black pigment;
wherein said black pigment has a grain size of at most 5μ and a grain size distribution characterized by a D 50 <2μ and consists of a Cr—Fe—Co—Mn spinel; and
wherein said colorless zinc-containing glass flux consists, in percent by weight, of:
Li 2 O
0-5
Na 2 O
0-5
K 2 O
<2
Σ Li 2 O + Na 2 O + K 2 O
1-10
MgO
0-3
CaO
0-4
SrO
0-4
BaO
0-4
ZnO
0-4
B 2 O 3
15-27
Al 2 O 3
10-20
SiO 2
43-58
TiO 2
0-3
ZrO 2
0-4
Sb 2 O 3
0-2
F
0-3.