Heidelberger Druckmaschinen Ag

Thomas Paul

Peter Hachmann

Christoph Michel

Els Mannekens

Radiation-curable compositions of Pigment Violet 23 are described which can be used advantageously in UV inks for inkjet printing machines. Soiling containing such UV inks, especially within inkjet printing machines, can be removed particularly easily in a contactless procedure with conventional cleaners. The radiation-curable compositions described contain at least one modified Pigment Violet 23 which carries at least one polar functional group of the formula (I):—X-E   (I)

Radiation-curable compositions of pigment violet 23 with improved removability from surfaces, method of making a radiation-curable composition and ink containing a radiation-curable composition

A method for producing a printed product includes coating a preferably paper or cardboard substrate with a precoat or supplying a substrate that has been coated with a precoat, in which the precoat contains at least one acid, applying a water-based ink to image areas on the coated substrate by using at least one ink print head, and drying the printed substrate and/or the ink, preferably using IR radiation and/or heated air. The precoat includes a photobase generator or a photobase generator is applied at least locally to non-image areas on the substrate, the substrate is irradiated at least locally in non-image areas, preferably using UV radiation, to locally generate a base, and the printed substrate is varnished with a water-based varnish.

Method for producing printed products and printing machine for implementing the method

A method for manufacturing printed products contains the steps of applying at least one colored and water-containing ink to image regions on a printing material in a drop-on-demand process. An essentially colorless and water-containing liquid is applied a) to non-image regions and/or b) to image regions that have only little ink in the drop-on-demand process. The printing material is dried. The printing material has a coating that contains at least one acid. After the application of ink and the application of a liquid, a water-containing further liquid, for instance a varnish, is applied both to image regions and to non-image regions of the printing material, and that the liquid and/or the further liquid contains at least one substance that at least partly neutralizes the acid. The undesired formation of waves and glossiness fluctuations between varnished image regions and varnished non-image regions may thus advantageously be avoided.

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Heidelberg, Germany

Thomas Paul