Patent ID: 6159585
Filing Date: 2000-12-12
Classification: D21H,Y10S,Y10T

Abstract:
A security paper which forms an indelible color when contacted with an organic solvent comprising a web of cellulosic fibers, said web containing a metal mordant dye first co-reactant in particulate form chemically isolated from a mordant dye second co-reactant in particulate form, said mordant dye second co-reactant forming a coordinate covalent bond with said metal mordant dye first co-reactant to produce an organic solvent-insoluble colored reaction product when the paper is washed with an organic solvent, said chemical isolation preventing said coordinate covalent bond from forming until the paper is washed with an organic solvent and said organic solvent insoluble colored reaction product remaining entrapped in the web when the paper is washed with an organic solvent, wherein said organic solvent-insoluble colored reaction product does not form upon the application of pressure alone to said paper.