PRINTED THERMOPLASTIC FILM HAVING A PVB INK LAYER AND A RADIATION-CURED OVERPRINT COATING

1 . A coated, printed thermoplastic film for packaging applications comprising:

a substrate film formed from at least one thermoplastic material;

a printed image formed on the substrate film, the printed image being formed from at least one ink system which comprises a polyvinyl butyral carrier resin, a pigment dispersed in the carrier resin, a plasticizer and a coupling agent; and

an energy curable coating formed over the printed image.

2 . The thermoplastic film of claim 1 , wherein the substrate film comprises a polypropylene polymer.

3 . The thermoplastic film of claim 1 , wherein the substrate film comprises a polyethylene polymer.

4 . The thermoplastic film of claim 1 , wherein the printed image is formed from a first ink system which comprises a polyvinyl butyral carrier resin, a pigment dispersed in the carrier resin, a plasticizer and from about 0.5% to about 5% by weight of the ink system of a coupling agent, and at least a second ink system applied over the first ink system.

5 . The thermoplastic film of claim 4 , wherein the second ink system comprises a polyvinyl butyral carrier resin.

6 . The thermoplastic film of claim 4 , wherein the second ink system comprises a nitrocellulose carrier resin.

7 . The thermoplastic film of claim 1 , wherein the plasticizer is present in an amount of about 10% to about 40% by weight of the ink system.

8 - 13 . (canceled)

14 . A method of forming a printed, coated thermoplastic packaging material comprising:

providing a thermoplastic packaging material;

forming a printed image on at least one surface of the thermoplastic packaging material using at least one ink system comprising a polyvinyl butyral carrier resin, a pigment dispersed in the carrier resin, a plasticizer, and a silane coupling agent;

applying an energy curable coating over the printed image; and

exposing the energy curable coating to ionizing radiation to form a cured coating on the printed image.

15 . The method of claim 14 , wherein the thermoplastic packaging material comprises a polypropylene polymer.

16 . The method of claim 14 , wherein the thermoplastic packaging material comprises a polyethylene polymer.

17 . The method of claim 14 , wherein the printed image is formed by applying a first ink system, which comprises a polyvinyl butyral carrier resin, a pigment dispersed in the carrier resin, a plasticizer, and a silane coupling agent, to the surface of the thermoplastic packaging material, and applying at least a second ink system over the first ink system.

18 . The method of claim 17 , wherein the ink systems are applied using rotary screen, gravure, or flexographic techniques.

19 . The method of claim 17 , wherein the second ink system comprises a polyvinyl butyral carrier resin.

20 . The method of claim 17 , wherein the second ink system comprises a nitrocellulose carrier resin.

21 . The method of claim 14 , wherein the plasticizer is present in an amount of about 10% to about 40% by weight of the ink system.

22 . The method of claim 21 , wherein the plasticizer is polyurethane.

23 . The method of claim 14 , wherein the silane coupling agent is present in an amount of about 0.5% to about 5% by weight of the ink system.

24 . The method of claim 14 , wherein the energy curable coating comprises an acrylate.

25 . The method of claim 14 , wherein the exposing step comprises exposing the energy curable coating to an electron beam radiation source having an energy in the range of about 50 to about 250 keV.

26 . The method of claim 25 , wherein the electron beam radiation source has an energy in the range of about 80 to about 120 keV.