US 12,252,846 B2
Multi-layer printing substrate with hidden information
Christoph Kocher, Landquart (CH); Muriel Schuler, Chur (CH); and Martin Demierre, Nyon (CH)
Assigned to Landqart AG, Landquart (CH)
Appl. No. 17/916,693
Filed by Landqart AG, Landquart (CH)
PCT Filed Mar. 25, 2021, PCT No. PCT/EP2021/057682
§ 371(c)(1), (2) Date Oct. 3, 2022,
PCT Pub. No. WO2021/197993, PCT Pub. Date Oct. 7, 2021.
Claims priority of application No. 20167810 (EP), filed on Apr. 2, 2020.
Prior Publication US 2023/0151551 A1, May 18, 2023
Int. Cl. D21H 27/36 (2006.01); A63F 3/06 (2006.01); B26F 1/38 (2006.01); B32B 3/26 (2006.01); B32B 27/08 (2006.01); B32B 27/18 (2006.01); B42D 25/328 (2014.01); B42D 25/351 (2014.01); B42D 25/46 (2014.01); D21H 21/42 (2006.01); D21H 21/44 (2006.01); D21H 23/46 (2006.01); B41M 3/14 (2006.01); B42D 25/305 (2014.01); B42D 25/355 (2014.01); B42D 25/369 (2014.01); B42D 25/378 (2014.01)
CPC D21H 27/36 (2013.01) [B26F 1/38 (2013.01); B32B 3/266 (2013.01); B32B 27/08 (2013.01); B32B 27/18 (2013.01); B42D 25/328 (2014.10); B42D 25/351 (2014.10); B42D 25/46 (2014.10); D21H 21/42 (2013.01); D21H 21/44 (2013.01); D21H 23/46 (2013.01); A63F 3/069 (2013.01); B32B 2260/028 (2013.01); B32B 2260/046 (2013.01); B32B 2307/718 (2013.01); B32B 2554/00 (2013.01); B41M 3/14 (2013.01); B42D 25/305 (2014.10); B42D 25/355 (2014.10); B42D 25/369 (2014.10); B42D 25/378 (2014.10)] 28 Claims
OG exemplary drawing
 
1. A multilayer substrate comprising
at least one first paper ply,
at least one second paper ply and
a plastic layer having two sides arranged between the paper plies and directly bonded to the paper plies on both sides of said plastic layer, which plastic layer is made of at least one thermoplastic polymeric material,
wherein between the paper plies on an inside of the second paper ply and at least partially embedded in the plastic layer a strip-shaped tear film is embedded,
wherein hidden information is arranged on at least one of
an inside of the first paper ply and perpendicular to and, viewed from a side of the second paper ply, covered by the strip-shaped tear film
and a surface of the strip-shaped tear film facing the first paper ply and covered at least by the first paper ply;
wherein the hidden information can be exposed by irreversibly tearing the strip-shaped tear film out of the multilayer substrate together with a strip of the second paper ply; and
wherein the multilayer substrate comprises public information correlated with the hidden information, wherein this public information is arranged on at least one of an exposed surface of the first or second paper ply and the surface of the strip-shaped tear film facing the first paper ply which is visible in a region of the public information through at least one corresponding window-shaped cutout in the first paper ply.