Safety inks and documents

• US 3,886,083 A
• Filed: 05/09/1974
• Issued: 05/27/1975
• Est. Priority Date: 05/09/1974
• Status: Expired due to Term

• Current Assignee: Mellon Bank National Association A National Banking Association
• Original Assignee: Herbert Laxer
• Inventors: Laxer, Herbert
• Primary Examiner(s): Mack, John H.
• Assistant Examiner(s): Weisstuch, Aaron
• Application Number:
  US05/468,409
• Time in Patent Office: 383 Days
• Field of Search: 252/31.2R,31.3R 117/1,33.5T 106/21,23 283/8R,9R
• US Class Current: 252/301.16
• CPC Class Codes: B41M 3/144 using fluorescent, luminescent or iridescent effects
• CPC Class Codes: C09D 11/50 Sympathetic, colour changing or similar inks
• CPC Class Codes: Y10S 428/916 Fraud or tamper detecting
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]

Abstract

This safety ink is useful for printing a background of fine lines or dots on a document of value, such as a bank check. The background extends over an area which is adapted to be written upon. If the area in question is written upon and an attempt is thereafter made to eradicate the writing, the background changes color, thereby making it obvious upon visual inspection that an attempt has been made to alter the writing. The ink includes a dye which is soluble and bleachable and a fluorescent pigment whose fluorescence is enhanced if the attempted alteration is by means of a dissolving or bleaching technique, so that removal of part of the dye results in a change in color and also in an enhancement of the fluorescent intensity of the remaining printed matter. If an attempt is made to alter the writing by erasure, rather than eradication, some of the fluorescent pigment is removed, and its fluorescent intensity is consequently decreased. Hence, an attempted alteration is detectable either under ordinary light by the change in visible color or under ultraviolet light by the change in the fluorescent intensity.

Claims

1. A PRINTING INK CONSISTING ESSENTIALLY OF COLORING MATTER AND A VEHICLE SOLUBLE IN WATER AND LOWER ALCOHOLS AND LOWER KETONES, SAID VEHICLE CONSISTING ESSENTIALLY OF GLYCERINE, SORBITOL AND WATER, THE GLYCERINE BEING PRESENT IN AN AMOUNT IN THE RANGE 10-30% BY WEIGHT BASED ON SAID VEHICLE, THE REMAINING PERCENTAGES OF SORBITOL AND WATER HAVING A WEIGHT RATIO OF ABOUT 4:

1, SAID COLORING MATTER INCLUDING A DYE SOLUBLE IN LOWER ALCOHOLS AND LOWER KETONES WHEREIN SAID LOWER ALCOHOLS AND SAID LOWER KETONES CONTAIN NOT MORE THAN 8 CARBON ATOMS PER MOLECULE, AND A FLUORESCENT PIGMENT WHICH IS NONBLEACHABLE, INSOLUBLE IN WATER AND NO MORE THAN VERY SLIGHTLY SOLUBLE IN SAID LOWER ALCOHOLS AND LOWER KETONES.

2. A PRINTED DOCUMENT COMPRISING: