US 12,138,893 B2
Method for forming a PVOH based barrier layer on a substrate
Ali Naderi, Arboga (SE); and Johan Larsson, Gavle (SE)
Assigned to BILLERUDKORSNAS AB, Solna (SE)
Appl. No. 17/296,093
Filed by BILLERUDKORSNAS AB, Solna (SE)
PCT Filed Nov. 27, 2019, PCT No. PCT/EP2019/082769
§ 371(c)(1), (2) Date May 21, 2021,
PCT Pub. No. WO2020/109401, PCT Pub. Date Jun. 4, 2020.
Claims priority of application No. 18208433 (EP), filed on Nov. 27, 2018; and application No. 18208434 (EP), filed on Nov. 27, 2018.
Prior Publication US 2022/0009212 A1, Jan. 13, 2022
Int. Cl. C08J 5/00 (2006.01); B05D 1/38 (2006.01); B05D 3/02 (2006.01); B32B 27/30 (2006.01); B65D 25/14 (2006.01); B65D 65/42 (2006.01); B65D 85/72 (2006.01); C09D 5/00 (2006.01); C09D 129/04 (2006.01); D21H 19/20 (2006.01); D21H 27/10 (2006.01)
CPC B32B 27/30 (2013.01) [B05D 1/38 (2013.01); B05D 3/0254 (2013.01); B65D 25/14 (2013.01); B65D 65/42 (2013.01); B65D 85/72 (2013.01); C08J 5/00 (2013.01); C09D 5/00 (2013.01); C09D 129/04 (2013.01); D21H 19/20 (2013.01); D21H 27/10 (2013.01); B05D 2203/00 (2013.01); B05D 2507/005 (2013.01)] 14 Claims
 
1. A method for the production of a packaging material comprising a substrate and a gas barrier layer based on polyvinyl alcohol (PVOH), said method comprising the steps of:
applying a coating composition of said PVOH dissolved in a first solvent onto said substrate to form a coating;
subjecting the coating to a first drying step to form a dried PVOH-based coating on said substrate, wherein the dried PVOH-based coating comprises regions of crystallized PVOH structures separated by regions of amorphous PVOH;
contacting the dried PVOH-based coating with a crosslinking solution comprising a crosslinking agent in a second solvent, to effect crosslinking of the PVOH-based coating; and
subsequent to the contact with the crosslinking solution, subjecting the PVOH-based coating to
a second drying step, forming the PVOH-based barrier layer on said substrate;
with the proviso that if the crosslinking solution comprises PVOH, the amount of PVOH added by the crosslinking solution is less than 20% (by weight) of the amount of PVOH added by the coating composition.