Print receptive topcoat
A water based wet topcoat comprising a cationic acrylic polymer is provided. The wet topcoat also water and a binder. The wet topcoat is coated into a substrate and is print receptive to a variety of printing techniques. The substrate may be a label or paper. The topcoat advantageously has strong adhesion to the substrate or paper.
1. A water based print receptive top coat formulation, said water based print receptive top coat formulation coat comprising:
i) a cationic acrylic polymer having a hydroxyl value in the range of 65 to 80;
ii) water; and
iii) a binder;
wherein the cationic acrylic polymer is present in an amount from 20 to 80 parts by weight,
based on a total of 100 parts by weight of the water based print receptive top coat formulation;
wherein the water based print receptive top coat formulation adheres to paper, polyester, biaxially oriented polypropylene, polyethylene, polypropylene, polyvinyl chloride, nylon, and the like, and which retains print from UV flexo, water based flexo, thermal transfer (TT) UV inkjet, cold foil, hot foil, letterpress, serigraphy, HP Indigo, offset, cold laser, hot laser, liquid toner inks, and dry toner inks;
wherein the binder is present in an amount from 0.1 to 30 parts by weight, based on a total of 100 parts by weight of the water based print receptive top coat formulation; and
wherein the binder is polyvinyl pyrrolidone/vinyl acetate copolymer (PVP/VA) having a weight ratio of vinyl pyrrolidone to vinyl acetate in a range of about 50:50 to about 80:20 vinyl pyrrolidone to vinyl acetate, and the binder has a Tg of 90 to 115° C.
2. The water based print receptive top coat formulation according to claim 1 , wherein the cationic acrylic polymer is selected from the group consisting of an aliphatic cationic acrylate, an aromatic cationic acrylate, an aliphatic cationic methacrylate, and aromatic cationic methacrylate, and combinations thereof.
3. The water based print receptive top coat formulation according to claim 1 , wherein the formulation further comprises a crosslinker, and wherein the crosslinker comprises a dispersible formulation of polyfunctional aziridines, isocyanates, melamine resins, epoxies, oxazolines, carbodiimides or other multifunctional crosslinkers.
4. The water based print receptive top coat formulation according to claim 1 , wherein the formulation further comprises a crosslinker, and wherein the crosslinker is present in a range of about 1 to 5%, based on the total solids of the cationic acrylic polymer.
5. The water based print receptive top coat formulation according to claim 1 , wherein the cationic acrylic polymer has an acid value in the range of about 6 to 14.
6. The water based print receptive top coat formulation according to claim 1 , wherein the cationic acrylic polymer has a pH in the range of about 5 to 6.9.
7. The water based print receptive top coat formulation according to claim 1 , wherein the cationic acrylic polymer has a viscosity in the range of about 500 to about 800 cps.
8. A dried top coat formed from the water based print receptive top coat formulation according to claim 1 .
9. The dried top coat according to claim 8 , wherein the dried top coat has a surface energy from 25 to 55 mN/m.
10. The dried top coat according to claim 8 , wherein the dried top coat has a coat weight from 0.1 to 1.5 gsm.
11. A label comprising a substrate and the dried top coat according to claim 8 .
12. A water based print receptive top coat formulation, said water based print receptive top coat formulation consisting of:
i) a cationic acrylic polymer having a hydroxyl value in the range of 65 to 80;
ii) water;
iii) a binder;
iv) optionally a crosslinker;
v) optionally a surfactant;
vi) optionally a cationic wax; and
vii) optionally one or more additives selected from the group consisting of defoaming agents, antioxidants, UV stabilizers, fillers, anti-blocking agents, and anti-freeze additives;
wherein the cationic acrylic polymer is present in an amount from 20 to 80 parts by weight, based on a total of 100 parts by weight of the water based print receptive top coat formulation;
wherein the water based print receptive top coat formulation adheres to paper, polyester, biaxially oriented polypropylene, polyethylene, polypropylene, polyvinyl chloride, nylon, and the like, and which retains print from UV flexo, water based flexo, thermal transfer (TT) UV inkjet, cold foil, hot foil, letterpress, serigraphy, HP Indigo, offset, cold laser, hot laser, liquid toner inks, and dry toner inks;
wherein the binder is present in an amount from 0.1 to 30 parts by weight, based on a total of 100 parts by weight of the water based print receptive top coat formulation;
wherein the binder is polyvinyl pyrrolidone/vinyl acetate copolymer (PVP/VA) having a weight ratio of vinyl pyrrolidone to vinyl acetate in a range of about 50:50 to about 80:20 vinyl pyrrolidone to vinyl acetate, and the binder has a Tg of 90 to 115° C.