David W Rittenhouse

US Patent:

61595853, Dec 12, 2000

Filed:

Sep 23, 1999

Appl. No.:

9/401664

Inventors:

David A. Rittenhouse - Roswell GA

Assignee:

Georgia-Pacific Corporation - Atlanta GA

International Classification:

B32B 300
B32B 516
B32B 2900

US Classification:

428199

Abstract:

A security paper indicates exposure to a solvent by a solvent resistant color signal. A metal mordant dye first co-reactant and a mordant dye second co-reactant form an organic solvent-insoluble colored reaction product when the paper is washed with an organic solvent. The metal mordant dye first co-reactant and a mordant dye second co-reactant are chemically isolated from each other so as to prevent the coordinate covalent bond from forming until the paper is washed with an organic solvent. The chemical isolation can be effected by encapsulation or other physical separation of the co-reactants. The organic solvent-insoluble colored reaction product, once formed, remains entrapped in the web when the paper is washed with an organic solvent. The chemical isolation prevents the organic solvent-insoluble colored reaction product from forming upon the application of pressure alone to the paper.