Eradicable inks

• US 6,221,432 B1
• Filed: 04/28/1999
• Issued: 04/24/2001
• Est. Priority Date: 03/25/1997
• Status: Expired due to Term

• Current Assignee: Berol Corp (Newell Brands Inc.)
• Original Assignee: Berol Corp (Newell Brands Inc.)
• Inventors: Wang, Yichun, Hopson, Russell E.
• Primary Examiner(s): Parker, Fred J.
• Application Number:
  US09/301,491
• Time in Patent Office: 727 Days
• Field of Search: 427/1, 427/466, 427/337, 427/258, 427/261, 427/145, 427/340, 252/183.13, 101/491, 106/31.32, 106/31.64
• US Class Current: 427/337
• CPC Class Codes: C09B 69/02 Dyestuff salts, e.g. salts of acid dyes with basic dyes for Na, K or NH4+ salts or for chlorides, sulfates or chlorozincates, see the relevant dye groups
• CPC Class Codes: C09D 11/17 characterised by colouring agents

Abstract

A method of changing the color of an ink mark includes applying an ink including a solvent and a triarylmethane dye dissolved in the solvent that changes color if contacted with a chemical agent to a substrate. The dye is soluble in phenyl cellosolve. A chemical agent is then applied to cause the dye to change color.

Claims

1. A method of changing the color of an ink mark, comprising

applying an ink comprising an essentially non-aqueous solvent and a triarylmethane dye including a hydrophobic organic counterion dissolved in said solvent that changes color if contacted with a chemical agent to a substrate to provide an ink mark, and

applying said chemical agent to said ink mark to cause said triarylmethane dye to change color.

2. The method of claim 1, wherein said chemical agent comprises a sulfite.

3. The method of claim 1, wherein said chemical agent comprises an amine.

4. The method of claim 1, wherein said ink is provided in a ball-point pen and said ink is applied to said substrate by writing on said substrate with said ball-point pen to transfer said ink to said substrate.

5. The method of claim 1, wherein said solvent comprises a non-volatile organic solvent.

6. A method of changing the color of an ink mark, comprising

applying and ink comprising a solvent and a triarylmethane dye dissolved is said solvent that changes color if contacted with a chemical agent to a substrate to provide an ink mark, said triarylmethane dye being soluble in phenyl cellosolve, and

applying said chemical agent to said ink mark to cause said triarylmethane dye to change color.

7. The method of claim 6, wherein said chemical agent comprises a sulfite.

8. The method of claim 6, wherein said chemical agent comprises an amine.

9. The method of claim 6, wherein said ink is provided in a ball-point pen and said ink is applied to said substrate by writing on said substrate with said ball-point pen to transfer said ink to said substrate.