Controlling ink diffusion in watercolor copying
OwnerBarbara S. Zasloffinventor
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Abstract
A method for limiting the diffusion of ink through a planographic plate comprising a polymetric matrix containing liquid, as for example an agar matrix, is described. Incorporated in the matrix is a diffusion inhibitor which has a binding affinity for the water soluble dye comprising the ink. The additives are cationic or anionic surfactants and the dyes employed are anionic or cationic. When an anionic surfactant a cationic dye is used and vice-versa.
Claims9
A planographic printing plate comprising an agar matrix containing an aqueous liquid and constituting a gel having pores of a size sufficient to prevent migration of dye molecules therethrough,
- said matrix containing a surfactant selected from the class of anionic or cationic surfactants,
- wherein the cationic surfactant is a member of the class consisting of quaternary alkylaryl ammonium compounds and polymeric cationic surfactants,
- the anionic surfactant is a member of the class consisting of alkyl sulfonates, alkyl sulfates, alkylaryl sulfonates, alkylaryl sulfates and alkali metal salts of carboxylic acids,
- said matrix containing additionally a non-ionic detergent selected from the group consisting of alkylaryl polyether alcohol, polyoxyethylene (20) sorbitan monopalmitate or polyoxyethylene lauryl ether.
A planographic printing plate comprising an agar matrix containing an aqueous liquid and constituting a gel having pores of a size sufficient to prevent migration of dye molecules therethrough,
- said matrix containing additionally a surfactant selected from the group consisting of anionic or cationic surfactants,
- said planographic plate having inked lines or designs thereon,
- said ink comprising a water soluble dye selected from the group consisting of anionic or cationic dyes,
- wherein when the surfactant is cationic the dye is anionic, and
- when the surfactant is anionic the dye is cationic.
Dependencies are inferred from the claim text.