Nova Patents
WO0202700A3

Erasable inks, writing instruments, and methods

Abstract

Erasable inks are provided for use in a writing instruments. In one aspect, the inks include a solvent, and, dispersed in the solvent as a colorant, a pigment having a flake-like morphology, the ink being substantially free of other colorants.

Term

No projected expiry on record.

  1. Priority
  2. Filed
  3. Published
  4. Today

1 claim: 1 independent, 0 dependent

  1. 1
    33 AMENDED CLAIMS [received by the International Bureau on 8 March 2002 (08.03.02); original claims 1, 8, 14 and 21-26 amended; original claims 7, 13 and 20 cancelled; new claims 27 and 28 added; remaining claims unchanged (5 pages)] 1. An erasable ink for use in a writing instrument, comprising:a solvent, and a pigment having a flake-like morphology dispersed in the solvent, wherein the ink is substantially free of colorants other than said pigment, and wherein said ink has a shear-thinning index of between about 0.01 and about 0.8. 2. The ink of claim 1 wherein said pigment is a pearlescent pigment. 3. The ink of claim 1 wherein said pigment is selected from the group consisting of metal-oxide coated micas, graphites, and metal flake pigments. 4. The ink of claim 1 wherein said pigment has an average diameter from about 3 microns to about 12 microns. 5. The ink of claim 1 wherein said ink exhibits an erasability of at least about 80%. 6. The ink of claim 1 wherein said solvent comprises an aqueous solvent system. 8. An erasable ink for use in a writing instrument, comprising: a solvent, and a flake-like pigment having an average diameter from about 3 microns to about 12 microns dispersed in the solvent, wherein said ink has a shear-thinning index of between about 0.01 and about 0.8. 9. The ink of claim 7 wherein said pigment is a pearlescent pigment. 10. The ink of claim 7 wherein said pigment is selected from the group consisting of metal-oxide coated micas, graphites, and metal flake pigments. 11. The ink of claim 7 wherein said ink exhibits an erasability of at least about 80%. 12. The ink of claim 7 wherein said solvent comprises an aqueous solvent system. 14. An erasable ink for use in a writing instrument, comprising: a solvent, and a flake-like pigment having an average thickness of less than about 0.25 microns dispersed in the solvent, wherein said ink has a shear-thinning index of between about 0.01 and about 0.8. 15. The ink of claim 14 wherein said pigment is a pearlescent pigment. 16. The ink of claim 14 wherein said pigment is selected from the group consisting of metal-oxide coated micas, graphites, and metal flake pigments. 17. The ink of claim 14 wherein said pigment has an average diameter from about 3 microns to about 12 microns. 18. The ink of claim 14 wherein said ink exhibits an erasability of at least about 80%. 19. The ink of claim 14 wherein said solvent comprises an aqueous solvent system. 35 21. A method of forming an erasable marking on a paper substrate, comprising: making a marking on the substrate with a writing instrument containing an erasable ink comprising a solvent and a pigment having a flake-like moφhology dispersed in the solvent, wherein the ink is substantially free of colorants other than said pigment, and wherein said ink has a shear-thinning index of between about 0.01 and about 0.8. 22. A method of forming an erasable marking on a paper substrate, comprising: making a marking on the substrate with a writing instrument containing an erasable ink comprising a solvent and a flake-like pigment having an average diameter from about 3 microns to about 12 microns dispersed in the solvent, wherein said ink has a shear-thinning index of between about 0.01 and about 0.8. 23. A method of forming an erasable marking on a paper substrate, comprising: making a marking on the substrate with a writing instrument containing an erasable ink comprising a solvent and a flake-like pigment having an average thickness of less than about 0.25 microns dispersed in the solvent, wherein said ink has a shear-thinning index of between about 0.01 and about 0.8. 24. A writing instrument, comprising: a reservoir containing an erasable ink comprising a solvent and a pigment having a flake-like moφhology dispersed in the solvent, wherein the ink is substantially free of colorants other than said pigment, and wherein said ink has a shear-thinning index of between about 0.01 and about 0.8. 25. A writing instrument, comprising: a reservoir containing an erasable ink comprising a solvent and a flake- 36 like pigment having an average diameter from about 3 microns to about 12 microns dispersed in the solvent, wherein said ink has a shear- thinning index of between about 0.01 and about 0.8. 37 26. A writing instrument, comprising: a reservoir containing an erasable ink comprising a solvent and a flakelike pigment having an average thickness of less than about 0.25 microns dispersed in the solvent, wherein said ink has a shear-thinning index of between about 0.01 and about 0.8. 27. An erasable ink for use in a writing instrument, comprising: a solvent, a pigment having a flake-like moφhology dispersed in the solvent, wherein the ink is substantially free of colorants other than said pigment, and a shear-thinning additive selected from the group consisting of clays, organoclays, water dispersible gums, and high molecular weight polymers of acrylic acid. 28. The ink of claim 27 wherein said solvent comprises an aqueous solvent system. STATEMENT UNDER ARTICLE 19(1) Transmitted herewith are substitute pages 29-31, 31/1, and 32, which have been amended pursuant to Article 19 of the Patent Cooperation Treaty. According to the amendments, original claims 1, 8, 14, and 21-26 have been amended, original claims 7, 13, and 20 have been cancelled, and new claims 27 and 28 have been added. Claims 2-6, 9-12, and 15-19 remain unchanged by these amendments. The claims have not been renumbered. Support for the amendment to claims 1, 8, 14, and 21-26 is found, for example, in original claims 7, 13, and 20 and at page 9, lines 27-28. Support for the amendment adding claim 27 is found, for example, in original claim 1 and at page 10, line 24 - page 12, line 6;support for newly added claim 28 is found, for example, in original claim 6. Accordingly, no new matter has been included. In accordance with Rule 62.2, copies of the present amendment and accompanying statement will also be filed with the International Preliminary Examining Authority (EP). Entry of the foregoing amendments is earnestly solicited.