Pigment/frit mixtures
Frits or frit mixtures with pearlescent pigments for materials, such as ceramic glazes, which are stable above 1000° C.
1. A pigment/frit mixture, comprising a mixture of a pearlescent pigment and a frit in the form of particles, wherein the proportion of pearlescent pigment in the mixture is 5-95% by weight and the frit comprises at least 5% by weight of Al 2 O 3 , based on the weight of the frit, wherein the pearlescent pigment is based on a flake substrate and the ratio of the thickness of the flake substrate to the size of the frit particles is from 0.01 to 0.2.
2. The pigment/frit mixture according to claim 1 , wherein the flake substrate is selected from: synthetic mica flakes, natural mica flakes, Al 2 O 3 flakes, SiO 2 flakes, Fe 2 O 3 flakes, B 4 C flakes, TiO 2 flakes, SiC flakes, BN flakes and graphite flakes.
3. The pigment/frit mixture according to claim 1 , wherein the flake substrate is covered with one or more layers of metal oxide(s), metal sulfides, rare-earth metal oxides and/or metal(s) or mixtures thereof.
4. The pigment/frit mixture according to claim 3 , wherein the flake substrate is covered on the surface with one or more layers selected from: TiO 2 , Fe 2 O 3 , ZrO 2 , SnO 2 , TiO 2 /Fe 2 O 3 , Fe 2 TiO 5 , FeTiO 3 , FeOOH, Fe 3 O 4 , Cr 2 O 3 and TiO x , where x=1.50-1.95.
5. The pigment/frit mixture according to claim 1 , wherein the flake substrate has a particle thickness of 0.05-5.0 μm.
6. The pigment/frit mixture according to claim 1 , wherein the frit has a particle size of 1-500 μm.
7. The pigment/frit mixture according to claim 1 , wherein the frit comprises CaO, Na 2 O, K 2 O, BaO, SiO 2 or B 2 O 3 .
8. The pigment/frit mixture according to claim 1 , wherein the frit comprises ≥5% by weight of Al 2 O 3 and ≥50% by weight of SiO 2 , based on the weight of the frit, where the totality of all constituents of the frit is 100%.
9. The pigment/frit mixture according to claim 1 , wherein the pearlescent pigment is selected from pigments having one of the following combinations of substrate and layer(s) thereon:
substrate flake+TiO 2 ;
substrate flake+Fe 2 O 3 ;
substrate flake+Fe 3 O 4 ;
substrate flake+TiO 2 /Fe 2 O 3
substrate flake+FeTiO 3 ;
substrate flake+Fe 2 TiO 5
substrate flake+ZrO 2 ;
substrate flake+ZnO;
substrate flake+SnO 2 ;
substrate flake+Cr 2 O 3 ;
substrate flake+Ce 2 O 3 ;
substrate flake+TiO x (reduced), where x=1.50-1.95;
substrate flake+TiO 2 +Fe 2 O 3 ;
substrate flake+TiO 2 +Fe 3 O 4 ;
substrate flake+Fe 2 O 3 +TiO 2 ;
substrate flake+TiO 2 +SiO 2 +TiO 2 ;
substrate flake+TiO 2 +SnO 2 +TiO 2 ;
substrate flake+TiO 2 +Al 2 O 3 +TiO 2 ;
substrate flake+Fe 2 O 3 +SiO 2 +TiO 2 ;
substrate flake+TiO 2 /Fe 2 O 3 +SiO 2 +TiO 2 ;
substrate flake+TiO 2 /Fe 2 O 3 +SiO 2 +TiO 2 /Fe 2 O 3 ;
substrate flake+TiO 2 /Fe 2 O 3 +SiO 2 +TiO 2 +TiO 2 /Fe 2 O 3 ;
substrate flake+TiO 2 +SiO 2 +TiO 2 /Fe 2 O 3 ;
substrate flake+TiO 2 +SiO 2 ;
substrate flake+TiO 2 +Al 2 O 3 ;
substrate flake+TiO 2 +MgO×SiO 2 +TiO 2 ;
substrate flake+Fe 2 O 3 +MgO×SiO 2 +TiO 2 ;
substrate flake+TiO 2 /Fe 2 O 3 +MgO×SiO 2 +TiO 2 ;
substrate flake+TiO 2 /Fe 2 O 3 +MgO×SiO 2 +TiO 2 /Fe 2 O 3 ;
substrate flake+TiO 2 /Fe 2 O 3 +MgO×SiO 2 +TiO 2 +TiO 2 /Fe 2 O 3 ;
substrate flake+TiO 2 +MgO×SiO 2 +TiO 2 /Fe 2 O 3 ;
substrate flake+SnO 2 +TiO 2 +SiO 2 +SnO 2 +TiO 2 ;
substrate flake+SnO 2 +TiO 2 +SnO 2 +TiO 2 ;
substrate flake+SnO 2 +TiO 2 +Fe 2 O 3 +SiO 2 +SnO 2 +TiO 2 +Fe 2 O 3 ;
substrate flake+Fe 2 O 3 +SnO 2 +TiO 2 ;
substrate flake+Fe 2 O 3 +SnO 2 +Fe 2 O 3 ;
substrate flake+TiO 2 +SnO 2 +TiO 2 ;
substrate flake+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 ;
substrate flake+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3 ;
substrate flake+SnO 2 +TiO 2 +Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3 ;
substrate flake+Fe 2 TiO 5 +SnO 2 +Fe 2 TiO 5 ;
substrate flake+Fe 2 TiO 5 +SiO 2 +Fe 2 TiO 5 .
10. The pigment/frit mixture according to claim 1 , wherein the pearlescent pigment is on a flake substrate and has a first low-refractive-index layer (=LRL) on the flake substrate comprising Al 2 O 3 , SiO 2 , zirconium silicate ZrSiO 4 , mullite 3Al 2 O 3 ×2SiO 2 or 2Al 2 O 3 ×SiO 2 (sintered or fused mullite) or alkaline-earth metal silicate (MSiO 3 , where M=Mg 2+ , Ca 2+ , Sr 2+ or Ba 2+ , or M 2 Si 3 O 8 , where M=Mg 2+ , Ca 2+ , Sr 2+ or Ba 2+ ).
11. The pigment/frit mixture according to claim 10 , wherein the pearlescent pigment is selected from pigments having one of the following combinations of substrate and layer(s) thereon: substrate flake+LRL+TiO 2 ;
substrate flake+LRL+Fe 2 O 3 ;
substrate flake+LRL+Fe 3 O 4 ;
substrate flake+LRL+TiO 2 /Fe 2 O 3 ;
substrate flake+LRL+FeTiO 3 ;
substrate flake+LRL+Fe 2 TiO 5 ;
substrate flake+LRL+ZrO 2 ;
substrate flake+LRL+ZnO;
substrate flake+LRL+SnO 2 ;
substrate flake+LRL+Cr 2 O 3 ;
substrate flake+LRL+Ce 2 O 3 ;
substrate flake+LRL+TiO x (reduced), where x=1.50-1.95;
substrate flake+LRL+TiO 2 +Fe 2 O 3 ;
substrate flake+LRL+TiO 2 +Fe 3 O 4 ;
substrate flake+LRL+Fe 2 O 3 +TiO 2 ;
substrate flake+LRL+TiO 2 +SiO 2 +TiO 2 ;
substrate flake+LRL+TiO 2 +SnO 2 +TiO 2 ;
substrate flake+LRL+TiO 2 +Al 2 O 3 +TiO 2 ;
substrate flake+LRL+Fe 2 O 3 +SiO 2 +TiO 2 ;
substrate flake+LRL+TiO 2 /Fe 2 O 3 +SiO 2 +TiO 2 ;
substrate flake+LRL+TiO 2 /Fe 2 O 3 +SiO 2 +TiO 2 /Fe 2 O 3 ;
substrate flake+LRL+TiO 2 /Fe 2 O 3 +SiO 2 +TiO 2 +TiO 2 /Fe 2 O 3 ;
substrate flake+LRL+TiO 2 +SiO 2 +TiO 2 /Fe 2 O 3 ;
substrate flake+LRL+TiO 2 +SiO 2 ;
substrate flake+LRL+TiO 2 +Al 2 O 3 ;
substrate flake+LRL+TiO 2 +MgO×SiO 2 +TiO 2 ;
substrate flake+LRL+Fe 2 O 3 +MgO×SiO 2 +TiO 2 ;
substrate flake+LRL+TiO 2 /Fe 2 O 3 +MgO×SiO 2 +TiO 2 ;
substrate flake+LRL+TiO 2 /Fe 2 O 3 +MgO×SiO 2 +TiO 2 /Fe 2 O 3 ;
substrate flake+LRL+TiO 2 /Fe 2 O 3 +MgO×SiO 2 +TiO 2 +TiO 2 /Fe 2 O 3 ;
substrate flake+LRL+TiO 2 +MgO×SiO 2 +TiO 2 /Fe 2 O 3 ;
substrate flake+LRL+SnO 2 +TiO 2 +SiO 2 +SnO 2 +TiO 2 ;
substrate flake+LRL+SnO 2 +TiO 2 +SnO 2 +TiO 2 ;
substrate flake+LRL+SnO 2 +TiO 2 +Fe 2 O 3 +SiO 2 +SnO 2 +TiO 2 +Fe 2 O 3 ;
substrate flake+LRL+Fe 2 O 3 +SnO 2 +TiO 2 ;
substrate flake+LRL+Fe 2 O 3 +SnO 2 +Fe 2 O 3 ;
substrate flake+LRL+TiO 2 +SnO 2 +TiO 2 ;
substrate flake+LRL+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 ;
substrate flake+LRL+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3 ;
substrate flake+LRL+SnO 2 +TiO 2 +Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3 ;
substrate flake+LRL+Fe 2 TiO 5 +SnO 2 +Fe 2 TiO 5 ;
substrate flake+LRL+Fe 2 TiO 5 +SiO 2 +Fe 2 TiO 5 .
12. An unfired or fired brick, unfired or fired earthenware, unfired or fired ceramicware or a ceramic glaze, which comprises a pigment/frit mixture according to claim 1 .
13. A decorative tile, which comprises a pigment/frit mixture according to claim 1 .
14. A porcelain glaze, which comprises a pigment/frit mixture according to claim 1 .
15. A composition comprising the pigment/frit mixture according to claim 1 and a dispersant, binder and/or printing oil.
16. A method of making an article which is an unfired or fired brick, unfired or fired earthenware, unfired or fired ceramicware or a ceramic glaze, wherein the article is prepared by firing it to a temperature above 1000° C., wherein, before firing, a pigment/frit mixture according to claim 1 is incorporated into a composition used to prepare the article.
17. The method of claim 16 , wherein the article is a decorative tile.
18. The method of claim 16 , wherein the article is a porcelain glaze.
19. The pigment/frit mixture according to claim 1 , wherein the Al 2 O 3 content in the frit is ≥7% by weight based on the weight of the frit.