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US 11,981,810 B2Granted
Film comprising polylactic acid polymer suitable for graphic articles
Assignee3M Innovative Properties Company
InventorsNing Zhou, Diane North, Matthew A. Jast
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Abstract
An article is described comprising a first film layer comprising polylactic acid polymer (semicrystalline polylactic acid polymer; amorphous polylactic acid polymer; or a mixture thereof); a second (e.g. polyvinyl acetate) polymer having a Tg of at least 25° C.; plasticizer. In some embodiment, the film layer further comprises inorganic pigment and/or hydrolysis stabilizer. In other embodiments, the film has a net melting endotherm, ΔHnm1, of less than 10 J/g. Also described are methods of making a graphic film.
Claims16
An article comprising
- a first film layer comprising
- semicrystalline polylactic acid polymer;
- amorphous polylactic acid polymer, wherein the total amount of polylactic acid polymer(s) ranges from 40 to 70 wt. % based on the total weight of polylactic acid polymer(s), polyvinyl acetate polymer, and plasticizer and the weight ratio of amorphous polylactic polymer to semicrystalline polylactic polymer ranges from 2:1 to 4:1;
- polyvinyl acetate polymer having a Tg of at least 25° C. in an amount ranging from 15 to 40 wt. % based on the total weight of polylactic acid polymer(s), polyvinyl acetate polymer, and plasticizer;
- 5 to 20 wt. % plasticizer based on the total weight of polylactic acid polymer(s), polyvinyl acetate polymer, and plasticizer;
- hydrolysis stabilizer;
- and
- an inorganic pigment in an amount such that the weight ratio of polylactic acid polymer to inorganic pigment is less than 4.5:1;
- and
- wherein the first film layer has a tensile modulus of at least 500 MPa for a strain rate of 600%/minute.
7 more elements
Dependencies are inferred from the claim text.