Latent image jet inks

• US 5,935,308 A
• Filed: 07/31/1998
• Issued: 08/10/1999
• Est. Priority Date: 07/31/1998
• Status: Expired due to Fees

• Current Assignee: Marconi Data Systems Incorporated (Danaher Corporation)
• Original Assignee: Videojet Systems International Incorporated (Danaher Corporation)
• Inventors: Siddiqui, Mohammed W., Lent, Bruce A.
• Primary Examiner(s): Bell, Mark L.
• Assistant Examiner(s): FAISON, VERONICA F
• Application Number:
  US09/127,243
• Time in Patent Office: 375 Days
• Field of Search: 106/31.14, 106/31.17, 106/31.2
• US Class Current: 106/31.14
• CPC Class Codes: C09D 11/36 based on non-aqueous solvents
• CPC Class Codes: C09D 11/50 Sympathetic, colour changing or similar inks

Abstract

A latent image printing process by applying to a substrate a latent image ink composition containing zinc bromide with an ink jet printer. Subsequently, the latent image is activated to render it visible, by application of an activator.

Claims

1. A latent image ink composition for use in ink jet printing comprising:

a. zinc bromide; and

b. a carrier;

said composition having (1) a viscosity from about 1.6 to about 7.0 centipoises at 25°

C.;

(2) an electrical resistivity from about 50 to about 2000 ohm-cm; and

(3) a sonic velocity from about 1200 to about 1300 meters/second; and

said composition being substantially invisible when printed upon a white or light colored substrate.

2. The composition of claim 1 further comprising tetraethylammonium p-toluene sulfonate as a conductivity agent.

3. The composition according to claim 1, further comprising a surfactant capable of modifying the surface tension of said ink composition.

4. The composition according to claim 3, wherein said surfactant is a fluorinated alkyl ester.

5. The composition according to claim 1, wherein the carrier is ethanol or denatured ethanol.

6. A method of printing a latent image on a substrate, comprising ink jet printing onto said substrate a latent image ink composition, said composition comprising:

a. zinc bromide; and

b. a carrier;

said composition having (1) a viscosity from about 1.6 to about 7.0 centipoises at 25°

C.;

(2) an electrical resistivity from about 50 to about 2000 ohm-cm; and

(3) a sonic velocity from about 1200 to about 1300 meters/second; and

said composition being substantially invisible when printed upon a white or light colored substrate.

7. The method of claim 6 further comprising tetraethylammonium p-toluene sulfonate.

8. The method according to claim 6, further comprising a surfactant capable of modifying the surface tension of said ink composition.

9. The method according to claim 8, wherein said surfactant is a fluorinated alkyl ester.

10. The method according to claim 9 wherein the carrier is ethanol or denatured ethanol.