MOISTURE RESISTANT COATING
Some embodiments of the invention generally relate to a moisture barrier coating that is biodegradable and compostable. Some embodiments also relate to a coating that is dual ovenable. Such coatings may be used to increase moisture resistance and provide non-stick or release characteristics when applied to biodegradable and compostable disposable food packaging and food service items. In some embodiments, a plasticizer or an amide wax are added to a cellulose-ester, shellac, and rosin based coating to increase moisture resistance and reduce brittleness. In other embodiments, phospholipids or medium-chain triglycerides or increased levels of amide wax may be added to the either of the embodiments above to provide enhanced release characteristics.
1 . A coating on a substrate comprising:
a cellulose ester,
a shellac; and
a rosin.
2 . The coating of claim 1 further comprising a wax, a plasticizer, a release agent, or a combination thereof.
3 . The coating of claim 2 wherein the cellulose ester comprises cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate, or nitrocellulose; the shellac comprises regular bleached shellac; and the rosin comprises natural rosin.
4 . The coating of claim 3 wherein the optional wax comprises oleamide, N,N′-ethylene-bis-oleamide, or N,N′-ethylene-bis-stearamide.
5 . The coating of claim 3 wherein the optional plasticizer comprises a citric acid ester, triacetin, tributyrin, or epoxidized soybean oil.
6 . The coating of claim 3 wherein the optional release agent comprises a phospholipid or a medium chain triglyceride.
7 . The coating of claim 1 wherein the cellulose ester comprises cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate, or nitrocellulose.
8 . The coating of claim 1 wherein the shellac comprises regular bleached shellac.
9 . The coating of claim 1 wherein the rosin comprises natural rosin.
10 . The coating of claim 1 wherein the coating is biodegradable or compostable.
11 . The coating of claim 1 wherein the substrate comprises starch, cellulose, a cellulose derivative, or PLA.
12 . The coating of claim 1 wherein the substrate comprises paper, paper board, or a starch-based matrix containing paper or cellulose fibers.
13 . A coating on a substrate comprising:
a cellulose ester,
a wax; and
a rosin.
14 . The coating of claim 13 further comprising a plasticizer, a release agent, or a combination thereof.
15 . The coating of claim 14 wherein the cellulose ester comprises cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate, or nitrocellulose; and the rosin comprises natural rosin.
16 . The coating of claim 15 wherein the plasticizer comprises a citric acid ester, triacetin, tributyrin, or epoxidized soybean oil.
17 . The coating of claim 15 wherein the release agent comprises a phospholipid or a medium chain triglyceride.
18 . The coating of claim 13 wherein the cellulose ester comprises cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate, or nitrocellulose.
19 . The coating of claim 13 wherein the wax comprises oleamide, N,N′-ethylene-bis-oleamide, or N,N′-ethylene-bis-stearamide.
20 . The coating of claim 13 wherein the rosin comprises natural rosin.
21 . The coating of claim 13 wherein the coating is biodegradable or compostable.
22 . The coating of claim 13 wherein the substrate comprises starch, cellulose, a cellulose derivative, or PLA.
23 . The coating of claim 13 wherein the substrate comprises paper, paper board, or a starch-based matrix containing paper or cellulose fibers.
24 . A coating for application to a substrate comprising a cellulose ester, a shellac, a rosin, and a solvent, and optionally a wax, a plasticizer, or a release agent, wherein the solvent comprises methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethanol, propanol, acetone, water, or hydrocarbons.
25 . A coating for application to a substrate comprising a cellulose ester, a wax, a rosin, and a solvent, and optionally a plasticizer or a release agent, wherein the solvent comprises methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethanol, propanol, acetone, water, or hydrocarbons.