US 12,428,530 B2
Method of making a cellulose film comprising microfibrillated cellulose
Otto Nylén, Helsinki (FI); Isto Heiskanen, Imatra (FI); and Isabel Knöös, Säffle (SE)
Assigned to Stora Enso OYJ, Helsinki (FI)
Appl. No. 17/757,256
Filed by Stora Enso OYJ, Helsinki (FI)
PCT Filed Dec. 22, 2020, PCT No. PCT/IB2020/062324
§ 371(c)(1), (2) Date Jun. 13, 2022,
PCT Pub. No. WO2021/130668, PCT Pub. Date Jul. 1, 2021.
Claims priority of application No. 1951556-8 (SE), filed on Dec. 23, 2019.
Prior Publication US 2023/0002572 A1, Jan. 5, 2023
Int. Cl. C08J 5/18 (2006.01); B32B 7/06 (2019.01); D21H 11/18 (2006.01); D21H 17/25 (2006.01); D21H 17/36 (2006.01); D21H 23/28 (2006.01)
CPC C08J 5/18 (2013.01) [B32B 7/06 (2013.01); D21H 11/18 (2013.01); D21H 17/25 (2013.01); D21H 17/36 (2013.01); D21H 23/28 (2013.01); C08J 2301/02 (2013.01)] 13 Claims
 
1. A method for making a cellulose film comprising microfibrillated cellulose (MFC), said method comprising the steps of:
a. providing a casting substrate having at least one surface;
b. applying an aqueous emulsion of one or more vegetable oils to said surface of said casting substrate to provide a treated surface;
c. casting a film-forming composition on the treated surface of said casting substrate, said film-forming composition comprising MFC and a hydrophilic film-forming polymer, wherein said film-forming composition comprises 0.1-50 wt % of said hydrophilic film-forming polymer based on a total solids content of the film-forming composition, and wherein said hydrophilic film-forming polymer is selected from a group consisting of: polyvinyl alcohol (PVA), polyethylene glycol (PEG), and partly- or fully-hydrolysed derivatives thereof;
d. drying the film-forming composition on the casting substrate to form the cellulose film comprising microfibrillated cellulose (MFC); and
e. separating the cellulose film from the casting substrate.