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.
Claims28
(canceled)
The article of claim 29 wherein the inorganic pigment comprises TiO2.
The article of claim 29 wherein the amount of inorganic pigment is at least 15, 16, 17, 18, 19, or 20 wt. % of the first film layer.
The article of claim 29 wherein the ratio of polylactic acid polymer to inorganic pigment is at least 1:1 and less than 4.4:1, 4.3:1, 4.2:1, 4.1:1 or 4:1.
The article of claim 32 wherein the second polymer is a polyvinyl acetate polymer.
The article of claim 28 wherein the hydrolysis stabilizer is a carbodiimide compound.
The article of claim 32 wherein the article is a graphic film further comprising a graphic proximate a major surface of the film layer.
(canceled)
12-13. (canceled)
The article of claim 32 wherein the second polymer comprises a polyvinyl acetate polymer having a molecular weight ranging from 75,000 g/mol to 1,000,000 g/mol.
The article of claim 32 wherein the plasticizer is present in an amount ranging from 5 or 35 wt.-%, based on the total amount of polylactic acid polymer(s), second polymer and plasticizer.
(canceled)
The article of claim 32 wherein the first film layer is further characterized by any one or combination of the following properties:
- i) wherein the first film layer does not exhibit plasticizer migration when aged at 80° C. for 24 hours.
- ii) wherein the first film layer has a Tg for the second heating scan at a rate of 10° C./min of less than 40° C., 35° C., 30° C., 25° C. or 20° C.;
- iii) wherein the first film layer has a tensile elongation from 50% to 600% for a strain rate of 600%/minute;
- iv) wherein the first film layer has a tensile modulus from 50 MPa to 1100 MPa for a strain rate of 600%/minute;
- and
- v) wherein the first film layer has a tensile storage modulus as determined by dynamic mechanical analysis of at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 MPa for a temperature range from 25° C. to 80° C. when heated at a rate of 2 C.°/min.
(canceled)
The article of claim 32 wherein the first film layer is an annealed film.
The article of claim 32 wherein the first film layer is an unannealed film.
The article of claim 32 wherein the article further comprises a backing disposed on the opposing surface as the film layer.
The article of claim 32 wherein the article further comprises a pressure sensitive adhesive disposed on the opposing surface of the film layer or backing.
The article of claim 32 wherein the first film layer comprises a composition having a net melting endotherm for the second heating scan, ΔHnm2, of less than 10 J/g at a rate of 10° C./min.
24-27. (canceled)
The article of claim 32 wherein the first film layer further comprises hydrolysis stabilizer.
The article of claim 32 wherein the first film layer further comprises inorganic pigment.
30-31. (canceled)
An article comprising a first film layer comprising polylactic acid polymer consisting of amorphous polylactic acid polymer;
- a second polymer having a Tg of at least 25° C.;
- plasticizer;
- wherein the first film layer has a net melting endotherm for the first heating scan, ΔHnm1, of less than 10 J/g at a rate of 10° C./min.
33-42. (canceled)
Dependencies are inferred from the claim text.