Metallic ink composition and writing instrument containing same
Metallic ink compositions for use in capillary-action markers are provided. More particularly, a metallic ink composition includes an organic solvent, a metallic pigment, and a resin component.
1. An ink composition comprising:
(a) an organic solvent;
(b) a metallic pigment dispersed in the solvent;
(c) a resin component dissolved in the solvent,
wherein the ink composition has a pigment to resin component ratio between about 0.70 and about 2.00, and the resin component has a mean hydroxyl number between about 20 and about 120, and wherein the resin component comprises one or more hydroxylated resins selected from the group consisting of phenolic-modified rosin resins, terpene phenolic resins, novolac resins, and mixtures thereof.
2. The ink composition of claim 1 , wherein the organic solvent is an aliphatic hydrocarbon solvent.
3. The ink composition of claim 2 , wherein the aliphatic hydrocarbon solvent comprises one or more alkane hydrocarbons of length C5-C15.
4. The ink composition of claim 2 , wherein the aliphatic hydrocarbon solvent comprises one or more alkane hydrocarbons of length C15-C40.
5. The ink composition of claim 1 , wherein the metallic pigment comprises a metallic pigment selected from the group consisting of copper, zinc, aluminum, bronze, mica, oxides thereof, anodizes thereof, and combinations thereof.
6. The ink composition of claim 1 , wherein the metallic pigment comprises a copper/zinc alloy.
7. The ink composition of claim 6 , wherein the metallic pigment comprising the copper/zinc alloy has a weight ratio of copper to zinc between about 50:50 and about 95:5.
8. The ink composition of claim 6 , wherein the metallic pigment has a weight ratio of copper to zinc of about 70:30 and the ink composition has a pigment to resin component ratio between about 0.70 and 1.45.
9. The ink composition of claim 6 , wherein the metallic pigment has a weight ratio of copper to zinc of about 90:10 and the ink composition has a pigment to resin component ratio between about 1.20 and about 2.0.
10. The ink composition of claim 1 , wherein the metallic pigment has an average density between about 2.5 grams/cubic centimeter (g/cc) and about 12.5 g/cc at 20° C.
11. The ink composition of claim 1 , wherein the metallic pigment has a substantially planar morphology.
12. The ink composition of claim 1 , wherein the metallic pigment has an average thickness between about 0.01 microns and about 1 micron.
13. The ink composition of claim 1 , wherein the metallic pigment has an average diameter between about 0.5 microns and about 7.5 microns.
14. The ink composition of claim 1 , wherein the surface of the metallic pigment has been treated with a long chain fatty acid comprising 18 to 21 carbons.
15. The ink composition of claim 1 , wherein the metallic pigment is present in an amount between about 5 wt % and about 40 wt %, based on the total weight of the ink composition.
16. The ink composition of claim 1 , wherein the ink composition has a total resin content between about 5 wt % and about 35 wt %, based on the total weight of the ink composition.
17. The ink composition of claim 1 , wherein the resin component is substantially free of non-hydroxylated resins.
18. The ink composition of claim 1 , wherein the resin component further comprises one or more non-hydroxylated resins.
19. The ink composition of claim 18 , wherein the non-hydroxylated resin is selected from the group consisting of styrenated terpene resins and phenol-free rosin resins.
20. A marker comprising:
an ink reservoir and a porous nib,
the ink reservoir containing an ink composition comprising:
(a) an organic solvent;
(b) a metallic pigment dispersed in the solvent;
(c) a resin component dissolved in the solvent,
wherein the ink composition has a pigment to resin component ratio between about 0.70 and about 2.00, and the resin component has a mean hydroxyl number between about 20 and about 120.
21. A method of making a written mark, comprising:
providing a capillary-action marker comprised of an ink reservoir and a porous nib, the reservoir containing an ink composition comprising:
(a) an organic solvent;
(b) a metallic pigment dispersed in the solvent;
(c) a resin component dissolved in the solvent,
wherein the ink composition has a pigment to resin component ratio between about 0.70 and about 2.00, and the resin component has a mean hydroxyl number between about 20 and about 120, and
contacting the nib of the capillary-action marker to a substrate surface to make a written mark.
22. The marker of claim 20 , wherein the organic solvent is an aliphatic hydrocarbon solvent.
23. The marker of claim 22 , wherein the aliphatic hydrocarbon solvent comprises one or more alkane hydrocarbons of length C5-C15.
24. The marker of claim 22 , wherein the aliphatic hydrocarbon solvent comprises one or more alkane hydrocarbons of length C15-C40.
25. The marker of claim 20 , wherein the metallic pigment comprises a metallic pigment selected from the group consisting of copper, zinc, aluminum, bronze, mica, oxides thereof, anodizes thereof, and combinations thereof.
26. The marker of claim 20 , wherein the metallic pigment comprises a copper/zinc alloy.
27. The marker of claim 26 , wherein the metallic pigment comprising the copper/zinc alloy has a weight ratio of copper to zinc between about 50:50 and about 95:5.
28. The marker of claim 26 , wherein the metallic pigment has a weight ratio of copper to zinc of about 70:30 and the ink composition has a pigment to resin component ratio between about 0.70 and 1.45.
29. The marker of claim 26 , wherein the metallic pigment has a weight ratio of copper to zinc of about 90:10 and the ink composition has a pigment to resin component ratio between about 1.20 and about 2.0.
30. The marker of claim 20 , wherein the metallic pigment has an average density between about 2.5 grams/cubic centimeter (g/cc) and about 12.5 g/cc at 20° C.
31. The marker of claim 20 , wherein the metallic pigment has a substantially planar morphology.
32. The marker of claim 20 , wherein the metallic pigment has an average thickness between about 0.01 microns and about 1 micron.
33. The marker of claim 20 , wherein the metallic pigment has an average diameter between about 0.5 microns and about 7.5 microns.
34. The marker of claim 20 , wherein the surface of the metallic pigment has been treated with a long chain fatty acid comprising 18 to 21 carbons.
35. The marker of claim 20 , wherein the metallic pigment is present in an amount between about 5 wt % and about 40 wt %, based on the total weight of the ink composition.
36. The marker of claim 20 , wherein the ink composition has a total resin content between about 5 wt % and about 35 wt %, based on the total weight of the ink composition.
37. The marker of claim 20 , wherein the resin component comprises one or more hydroxylated resins selected from the group consisting of phenolic-modified rosin resins, terpene phenolic resins, novolac resins, and mixtures thereof.
38. The marker of claim 20 , wherein the resin component is substantially free of non-hydroxylated resins.
39. The marker of claim 20 , wherein the resin component further comprises one or more non-hydroxylated resins.
40. The marker of claim 39 , wherein the non-hydroxylated resin is selected from the group consisting of styrenated terpene resins and phenol-free rosin resins.