Nickel-free green pigment

1. A nickel-free green pigment comprising a solid solution of first and second mixed metal oxides,

a. the first mixed metal oxide having a [124] spinel structure, comprising

i. at least one element A selected from the group consisting of lithium and sodium,

ii. at least one element B selected from the group consisting of cobalt, zinc, calcium, magnesium, and copper,

iii. at least one element D selected from the group consisting of titanium, manganese, tin and germanium, and

b. the second mixed metal oxide having a [134] spinel structure, comprising

i. at least one element A selected from the group consisting of lithium and sodium,

ii. at least one element C selected from the group consisting of chromium, boron, iron, manganese and aluminum and,

iii. at least one element D selected from the group consisting of titanium, manganese, tin and germanium, and

c. no nickel.

2. The nickel-free green pigment of claim 1 , wherein the first mixed metal oxide has the formula BA(D 3 A)O 8 .

3. The nickel-free green pigment of claim 1 , wherein the second mixed metal oxide has the formula A 2 (C 2 D 2 )O 8 .

4. A paint or coating including the nickel-free green pigment of claim 1 .

5. The paint or coating of claim 1 having a TSR over black of at least 15.

6. A plastic composition including the nickel-free green pigment of claim 1 .

7. The nickel-free green pigment of claim 1 having a reflection of at least 50% over a wavelength range of 800-1100 nm.

8. The nickel-free green pigment of claim 1 having leachable Ni of less than 1 ppm according to DIN EN71/3:2013.

9. A method of making a nickel-free green pigment comprising a solid solution of first and second mixed metal oxides, the method comprising,

a. mixing particles of

i. a first mixed metal oxide having a [124] spinel structure, comprising

1. at least one element A selected from the group consisting of lithium and sodium,

2. at least one element B selected from the group consisting of cobalt, zinc, calcium, magnesium, and copper,

3. at least one element D selected from the group consisting of titanium, manganese, tin and germanium,

4. no nickel

with

ii. a second mixed metal oxide having a [134] spinel structure, comprising

1. at least one element A selected from the group consisting of lithium and sodium,

2. at least one element C selected from the group consisting of chromium, boron, iron, manganese and aluminum, and,

3. at least one element D selected from the group consisting of titanium, manganese, tin and germanium,

4. no nickel,

to form a mixture, and

b. heating the mixture at a temperature of 800-1700° C. for a time of 1 to 1000 minutes to form at least one of particles and agglomerates of a green pigment.

10. The method of claim 9 , further comprising cooling the green pigment to room temperature at a rate of 1-50° C. per minute.

11. The method of claim 9 , further comprising reducing the size of the pigment particles or agglomerates to a D 50 size of 1-10 microns.

12. The method of claim 9 , wherein the first mixed metal oxide has the formula BA(D 3 A)O 8 .

13. The method of claim 9 , wherein the second mixed metal oxide has the formula A 2 (C 2 D 2 )O 8 .

14. A method of imparting a green color to a substrate, comprising,

a. applying to a substrate and

b. firing

a nickel-free green pigment comprising a solid solution of first and second mixed metal oxides,

i. the first mixed metal oxide having a [124] spinel structure, comprising

1. at least one element A selected from the group consisting of lithium and sodium,

2. at least one element B selected from the group consisting of cobalt, zinc, calcium, magnesium, and copper,

3. at least one element D selected from the group consisting of titanium, manganese, tin and germanium, and

4. no nickel,

ii. the second mixed metal oxide having a [134] spinel structure, comprising

1. at least one element A selected from the group consisting of lithium and sodium,

2. at least one element C selected from the group consisting of chromium, boron, iron, manganese and aluminum and,

3. at least one element D selected from the group consisting of titanium, manganese, tin and germanium, and

4. no nickel.

15. The method of claim 14 , wherein the first mixed metal oxide has the formula BA(D 3 A)O 8 .

16. The method of claim 14 , wherein the second mixed metal oxide has the formula A 2 (C 2 D 2 )O 8 .

17. The method of claim 15 , wherein the second mixed metal oxide has the formula A 2 (C 2 D 2 )O 8 .

18. The method of claim 14 , wherein the substrate is selected from the group consisting of paints, curable coatings, inks, plastics, rubbers, ceramics, enamels, and glasses.

19. A method of imparting a green color to a plastic composition, comprising, melt mixing

a. a plastic composition, with

b. a nickel-free green pigment comprising a solid solution of first and second mixed metal oxides,

i. the first mixed metal oxide having a [124] spinel structure, comprising

1. at least one element A selected from the group consisting of lithium and sodium,

2. at least one element B selected from the group consisting of cobalt, zinc, calcium, magnesium, and copper,

3. at least one element D selected from the group consisting of titanium, manganese, tin and germanium, and

4. no nickel,

ii. the second mixed metal oxide having a [134] spinel structure, comprising

1. at least one element A selected from the group consisting of lithium and sodium,

2. at least one element C selected from the group consisting of chromium, boron, iron, manganese and aluminum,

3. at least one element D selected from the group consisting of titanium, manganese, tin and germanium, and

4. no nickel.

20. The method of claim 19 , wherein the first mixed metal oxide has the formula BA(D 3 A)O 8 .

21. The method of claim 19 , wherein the second mixed metal oxide has the formula A 2 (C 2 D 2 )O 8 .

22. The method of claim 20 , wherein the second mixed metal oxide has the formula A 2 (C 2 D 2 )O 8 .