Pressure-sensitive copying material

摘要

Pressure-sensitive copying material comprises a substrate carrying isolated droplets of an oil solution of chromogenic material confined within respective pressure-rupturable barriers. The chromogenic material develops a colour other than blue or black on contact with colour developer and comprises a component which is fluorescent. This enables the authenticity of the copying material to be verified by irradiation with ultra-violet light to produce fluorescence. The fluorescent material can be, for example 2,2-bis(4-ä2-Ä4-diethylaminophenylÜ-quinazolin-4-yloxyüphenyl) propane or 1-(3-methoxy-4-dodecyloxyphenyl)-2-(2'-quinolyl)ethylene. Non-fluorescent chromogenic material(s) are preferably used in combination with the fluorescent chromogenic material(s).