Oxygen barrier film, food packaging material comprising same, and method for producing oxygen barrier film

A method of preparing an oxygen barrier film, the method comprising:

• adding a silane coupling agent and a filler to an aqueous protein solution to prepare a pre-composition for an organic-inorganic hybrid layer;
• heat-treating and then cooling the pre-composition for the organic-inorganic hybrid layer to prepare a composition for the organic-inorganic hybrid layer;
• and
• applying the composition for the organic-inorganic hybrid layer onto a base layer to prepare the oxygen barrier film,
• wherein
• the aqueous protein solution comprises a protein selected from the group consisting of whey protein isolate (WPI), whey protein concentrate (WPC), soy protein isolate (SPI), rice protein isolate (RPI), oat Protein (oat protein isolate:
• OPI), pea protein isolate (PPI), casein, sodium caseinate and wheat protein (gluten),
• the filler is selected from the group consisting of sorbitol, fructose, sucrose, mannitol, propylene glycol, glycerol, and polyethylene glycol,
• the silane coupling agent is an aminosilane,
• the silane coupling agent reacts with the aqueous protein solution during the heat-treating to form a crosslinked protein-silane network via amide bonding, and
• the filler is disposed in holes of the crosslinked protein-silane network.