Abstract: The present invention relates to non-pigmented jet ink compositions and to a method of producing opaque coded messages therewith. The compositions comprise, on a weight basis, between 2 and 15% of a gellable cellulose ester having a hydroxyl content of from 2 to 8%, from 1.5 to 15% of a binding agent selected from the group consisting of alkali soluble rosin type and maleic type resins, polyvinyl acetate resins, and acrylic resins, and a solvent blend, the blend consisting essentially of an organic solvent system and a non-solvent, said non-solvent comprising from 2 to 10% by weight of the ink compositions. Preferred solvents are methanol, acetone, methyl ethyl ketone and ethyl acetate, while the preferred non-solvent is water. Upon evaporation of the solvent blend, the resultant dry films scatter light incident thereto whereby the opaque images are produced. In a particularly preferred embodiment, a hygroscopic salt is included in the composition as an opacity enhancement agent.

Abstract: The present invention relates to non-pigmented jet ink compositions and to a method of producing opaque coded messages therewith. The compositions comprise, on a weight basis, between 2 and 15% of a gellable cellulose ester having a hydroxyl content of from 2 to 8%, from 1.5 to 15% of a binding agent selected from the group consisting of alkali soluble rosin type and maleic type resins, polyvinyl acetate resins, and acrylic resins, and a solvent blend, the blend consisting essentially of an organic solvent system and a non-solvent, said non-solvent comprising from 2 to 10% by weight of the ink composition. Preferred solvents are methanol, acetone, methyl ethyl ketone and ethyl acetate, while the preferred non-solvent is water. Upon evaporation of the solvent blend, the resultant dry films scatter light incident thereto whereby the opaque images are produced. In a particularly preferred embodiment, a hygroscopic salt is included in the composition as an opacity enhancement agent.