Energy curable flexographic inks incorporating grafted pigments
AssigneeSun Chemical Corporation
InventorsMikhail Laksin, Subhankar Chatterjee, Russell J. Schwartz, Paul A. Merchak
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Abstract
Solvent-free, energy curable flexographic printing inks which contain a pigment; a rheological additive having the structure P-(U-Y)s, wherein P is the residue of an organic pigment or dye, Y is a polyalkylene oxide moiety, U is a linking moiety covalently bonding Y to P and s is an integer from 1 to 3; and an energy curable liquid vehicle which may be a ultraviolet cationic or a free radical initiated polymerization system, cured by actinic radiation; and optionally containing a photoinitiating system.
Claims27
An energy curable flexographic ink consisting essentially of a pigment;
- a rheological additive having the structure:
- P-(U-Y)s
- wherein P is the residue of an organic colorant, Y is a polyalkylene oxide moiety, U is a linking moiety covalently bonding Y to P, and s is an integer from 1 to 3 and;
- an energy curable liquid vehicle;
- wherein the ink is substantially free of fugitive solvent and has a viscosity ranging from about 50 cps to about 3000 cps.
A method of flexographic printing and curing a flexographic ink image comprising the steps of:
- (a) preparing an energy curable flexographic ink consisting essentially of a pigment and a rheological additive of the structure:
- P-(U-Y)s
- wherein P is the residue of an organic colorant, Y is a polyalkylene oxide moiety, U is a linking moiety covalently bonding Y to P, and s is an integer from 1 to 3;
- and an energy curable liquid vehicle;
- wherein the ink is substantially free of fugitive solvent and has a viscosity ranging from about 50 cps to about 3,000 cps;
- (b) printing the ink on a substrate surface to form an image;
- and
- (c) subjecting the image to actinic radiation or thermal energy to form a cured image.
Dependencies are inferred from the claim text.