Colorants comprising tin and rare earth elements

1. A pigment of empirical composition

(TiO 2 ) a (ZnO) b (SnO) c (SnO 2 ) d (REO y ) e (AEO) f (MO) g

wherein

REO y is an oxide in which RE is a transition group 3 metal or a rare earth metal and y varies from 1 to 2,

AEO is an oxide in which AE is an alkaline earth metal, and

MO is an oxide of a metal M which is any other metal, where

0.8≦a≦3;

0.5≦b≦1.3;

0.5≦c≦1.3;

0≦d0.5;

0≦e0.3;

0≦f≦0.3; and

0≦g≦0.1,

and e+f≧0.01.

2. The pigment according to claim 1 , wherein RE is selected from the group consisting of yttrium, lanthanum, cerium and praseodymium and mixtures thereof.

3. The pigment according to claim 1 , wherein AE is selected from the group consisting of calcium, strontium and barium and mixtures thereof.

4. The pigment according to claim 1 , wherein

1.0≦a≦3,

0.7≦b≦1.3, and

0.7≦c≦1.3.

5. The pigment according to claim 1 , wherein f=0.

6. The pigment according to claim 1 , wherein 0.01≦e≦0.3 and 0.01≦f≦0.3.

7. The pigment according to claim 1 , wherein e=0.

8. The pigment according to claim 1 , wherein M is Zr, Al, Si, V, Nb, Mo, W, Sb, Bi or Pb.

9. The pigment according to claim 1 , wherein MO is selected from the group consisting of ZrO 2 , Al 2 O 3 , and SiO 2 .

10. The pigment according to claim 1 , wherein M is selected from the group consisting of Zr, Al and Si.

11. The pigment according to claim 6 , wherein AE is selected from the group consisting of Ca, Sr and Ba.

12. The pigment according to claim 1 , wherein 0.01≦e≦0.3 and f=0.

13. The pigment according to claim 1 , wherein e=0 and 0.01≦f≦0.3.

14. The pigment according to claim 1 , wherein REO y is an oxide represented by REO, RE 2 O 3 , REO 2 , a combination of REO and RE 2 O 3 , or a combination of RE 2 O 3 and REO 2 .

15. A method of producing a pigment according to claim 1 , comprising

mixing TiO 2 , ZnO, SnO, optionally at least one of SnO 2 , RE x O y , AEO and M u O v , or a precursor compound thereof as a dry powder to form a powder mixture,

calcining the powder mixture at temperatures between 800 and 1100° C. under an inert gas atmosphere to form a furnace clinker, and

grinding the resulting furnace clinker.

16. The method according to claim 15 , wherein REO is selected from the group consisting of Y 2 O 3 , La 2 O 3 , CeO 2 and Pr 6 O 11 .

17. A pigment mixture comprising

a) 1% to 90% by weight of a pigment according to claim 1 and

b) 10% to 99% by weight of at least one of an organic or inorganic pigment and a platelet-shaped metallic or oxidic effect pigment.