Oxygen barrier coating and coated film
AssigneeMitsubishi Polyester Film GmbH
InventorsRobert Posey, Edwin C. Culbertson
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Abstract
A film with excellent oxygen barrier properties is disclosed. A barrier coating used thereon is also disclosed, including polyvinyl alcohol and a copolymer of maleic acid and acrylic acid, and wherein the copolymer of maleic acid and acrylic acid has a weight average molecular weight of about 3500 to about 5000. The barrier coating is typically less than about 1 micrometer in thickness and provides an oxygen barrier of less than about 0.3 cc.mil/100 in2/day/atm when tested at 23 degrees Celsius and 0 percent relative humidity according to ASTM D3985. A method of stripping low molecular eight fractions from the copolymer is also disclosed. Metallized coated film according to the present invention shows surprising barrier properties.
Claims24
A coated film comprising:
- a polyester base film layer;
- a barrier coating applied to said base film layer;
- wherein said barrier coating comprises polyvinyl alcohol and a copolymer of maleic acid and acrylic acid;
- and
- wherein said barrier coating is less than about 1 micrometer in thickness;
- said coated film providing an oxygen barrier of less than about 0.3 cc.mil/100 in2/day/atm when tested at 23 degrees Celsius and 0 percent relative humidity according to ASTM D3985;
- and wherein said copolymer of maleic acid and acrylic acid has a weight average molecular weight of about 3500 to about 5000.
A coated film comprising:
- a polymer base film layer;
- a barrier coating applied to said base film layer;
- and
- a metallized layer;
- wherein said barrier coating comprises a copolymer of maleic acid and acrylic acid, and a film former.
A method of forming a film with enhanced oxygen barrier properties, comprising the steps of:
- applying a coating to said film,
- wherein said coating includes polyvinyl alcohol and a copolymer of maleic acid and acrylic acid that has been subjected to a stripping process capable of removing low molecular weight fractions.
The method of 22, wherein said film is heated for about 1 to about 20 seconds.
Dependencies are inferred from the claim text.