Primer for digital printing
AssigneeSun Chemical Corporation
InventorsBrian Crombie, Joanne Guite, Peter Salthouse, Thierry Frinault
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Abstract
The present invention is directed to primer coatings that enhance the adhesion of liquid digital printing inks and toners to the substrate. The coatings comprise one or more polyurethane dispersions and one or more acrylic emulsions. The coatings of the present invention improve resistance to mineral oils, such as those typically found in liquid digital printing inks and toners. The primer coatings of the invention also reduce blocking, so that a primer coated reel of substrate may be easily unrolled, even after having been stored in the rolled reel for an extended period of time.
Claims17
A primer coating for enhancing adhesion of a digital liquid printing ink or toner to a substrate comprising:
- a) 45 wt % to 85 wt % of one or more polyurethane dispersions, based on the total weight of the primer;
- and
- b) 10 wt % to 30 wt % of one or more self-crosslinking acrylic emulsions, based on the total weight of the primer;
- and
- wherein the glass transition temperature (Tg) of the polyurethane is less than −55° C.;
- and wherein at least one self-crosslinking acrylic has a Tg above 25° C.
Dependencies are inferred from the claim text.