Sun Chemical Corporation

John Gerard Tiessen

Juanita M Parris

Michael J Jurek

Soichiro Omizu

Russell J Schwartz

Kai-Uwe W Gaudl

Terry Best

Xiang Jun Liu

Layers of energy curable inks and coatings containing little to no photoinitiator, are printed over or are covered with ink or coating layers that are not energy curable but do comprise a photoinitiator. All energy curable inks are then simultaneously cured when exposed to actinic radiation that passes through the ink or coating layers that are not energy curable but comprise photoinitiators.

Method of improving actinic cure of energy curable inks and coatings

The present invention provides an improved method for curing multi-layer constructs of energy curable (EC) inks and coatings with actinic radiation. In the method, one or more layers of EC inks and/or coatings comprising materials that can crosslink or polymerize when exposed to actinic radiation, e.g., monomers, oligomers or polymers, are applied to a substrate, which EC inks and coatings contain little or no photoinitiators. This is followed by applying one or more layers of non-EC inks and/or coatings, which comprise one or more organic peroxides but no readily polymerizable components, over the top of the layers of energy curable inks and/or coatings; and exposing the layers to actinic radiation.

Energy curable inks and coatings with peroxides

A method for printing on a substrate comprises two steps. The first step consists essentially of: applying onto a substrate one or more layers of an energy curable ink and applying one or more layers of a water-based coating over the top of the one or more layers of energy curable ink. The second step comprises the steps of, in any order: a) drying the one or more layers of water-based coating, and b) actinically or electron beam curing simultaneously all the energy curable ink layers.

Method of improving actinic cure of coatings

Described herein are depolymerized polystyrene resins derived from polystyrene source resins. The depolymerized polystyrene resins undergo a depolymerization in which chemical bonds are cleaved, producing depolymerized polystyrene resins of lower molecular weight. The polystyrene resins may be modified by chemical reaction with monomers, polymers, and oligomers, such as acrylates thereof. Also described are ink and coating compositions that include the depolymerized and modified polystyrene resins.

High molecular weight polystyrene in inks and coatings

The present invention provides a method for applying multiple ink and/or coating layers on a substrate. At least one of the ink and/or coating layers contains one or more photoinitiators, and at least one of the ink and/or coating layers does not contain any photoinitiators. In certain embodiments, all of the ink and/or coating layers are wet trapped and the entire print construct is cured by exposure to UV radiation after all of the ink and/or coating layers have been applied. In certain embodiments, the wet trapping method of the present invention can be used to prepare laminates.

Wet-trapping method

Methods and apparatus for flexographic color printing, and more particularly for implementing 'wet trapping' in flexographic printing using energy curable flexographic liquid inks are presented. Radiation curable inks can be formulated that wet trap over each other without back-trapping onto the plates and anilox units of down-line printing units by controlling the storage modulus of the inklcoating. The storage modulus G' in the inks can be controlled to ensure that the highest G&#x2032; ink is printed ISt down with successive colors being trapped in the order of their (declining) G&#x2032; values. An image in wet ink can thus be trapped over a different image in wet ink of a different color without picking the ISt ink back up and redepositing it onto the subsequent plates and rollers in the printing press (back-trapping).

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Elk Grove Village, IL, United States of America

John Gerard Tiessen