PHA-BASED RETORT FOOD POUCH
A retort food pouch is disclosed, including at least one sidewall and a pouch closure. The sidewall is a multi-layer structure which is made up of: (1) a biodegradable heat-sealable layer which includes polyhydroxyalkanoates; (2) a barrier layer which includes aluminum and/or polyhydroxyalkanoates; (3) optionally, a nylon layer; and (4) a biodegradable printed layer which also includes polyhydroxyalkanoates and/or cellulose. These layers are adhered together with one or more adhesives to form the multi-layer structure.
1 . A retort food pouch having at least one sidewall and a pouch closure, wherein the at least sidewall is a multi-layer structure comprising:
a biodegradable heat-sealable layer comprising polyhydroxyalkanoates;
a barrier layer comprising aluminum and/or polyhydroxyalkanoates;
optionally, a nylon layer; and
a biodegradable printed layer comprising polyhydroxyalkanoates,
wherein the layers are adhered together with one or more adhesives to form the multi-layer structure.
2 . The retort food pouch of claim 1 , wherein the biodegradable heat sealable layer comprises:
from about 10 to about 99 weight percent polyhydroxyalkanoates;
from about 1 to 90 weight percent of at least one biodegradable polymer selected from the group consisting of polybutylene succinate, polycaprolactone, polybutylene succinate-co-butylene adipate, polybutylene adipate-co-terephthalate, polylactic acid, cellulose acetate, and mixtures thereof;
from about 0.1 weight percent to about 5 weight percent of at least one nucleating agent selected from the group consisting of erythritols, pentaerythritol, dipentaerythritols, artificial sweeteners, stearates, sorbitols, mannitols, inositols, polyester waxes, nanoclays, behenamide, erucamide, stearamide, oleamide, polyhydroxybutyrate, boron nitride, and mixtures thereof; and
optionally, from about 1 to about 25 weight percent of at least one filler selected from the group consisting of clays, calcium carbonate, talc, kaolinite, montmorillonite, bentonite, silica, chitin, titanium dioxide, nano clay, and mixtures thereof.
3 . The retort food pouch of claim 2 , wherein the polyhydroxyalkanoate in the biodegradable heat sealable layer comprises poly-3-hydroxybutyrate-co-3-hydroxyhexanaote (P3HB-co-P3HHx).
4 . The retort food pouch of claim 2 , wherein the biodegradable heat sealable layer comprises from about 1.0 to about 15.0 weight percent of at least one polyhydroxyalkanoate comprising from about 25 to about 50 mole percent monomer residues of a 3-hydroxyalkanoate selected from the group consisting of 3-hydroxyvalerate, 3-hydroxyhexanoate, 3-hydroxyoctanoate, 3-hydroxydecanoate, and mixtures thereof.
5 . The retort food pouch of claim 2 , wherein the biodegradable heat sealable layer comprises a polyhydroxyalkanoate terpolymer made up from about 75 to about 99.9 mole percent monomer residues of 3-hydroxybutyrate, from about 0.1 to about 25 mole percent monomer residues of 3-hydroxyhexanoate, and from about 0.1 to about 25 mole percent monomer residues of a third 3-hydoxyalkanoate selected from the group consisting of 3-hydroxyvalerate, 3-hydroxyoctanoate, 3-hydroxydecanoate, and mixtures thereof.
6 . The retort food pouch of claim 2 , wherein the biodegradable heat sealable layer comprises polyhydroxyalkanoates having a weight average molecular weight from about 50 thousand Daltons to about 2.5 million Daltons as determined by ASTM D5296-05.
7 . The retort food pouch of claim 1 , wherein the barrier layer comprises:
from about 10 to about 99 weight percent polyhydroxyalkanoates;
from about 1 to 90 weight percent of at least one biodegradable polymer selected from the group consisting of polybutylene succinate, polycaprolactone, polybutylene succinate-co-butylene adipate, polybutylene adipate-co-terephthalate, polylactic acid, cellulose acetate, and mixtures thereof;
from about 0.1 weight percent to about 25 weight percent of at least one nucleating agent selected from the group consisting of erythritols, pentaerythritol, dipentaerythritols, artificial sweeteners, stearates, sorbitols, mannitols, inositols, polyester waxes, nanoclays, behenamide, erucamide, stearamide, oleamide, polyhydroxybutyrate, boron nitride, and mixtures thereof; and
optionally, from about 1 to about 25 weight percent of at least one filler selected from the group consisting of clays, calcium carbonate, talc, kaolinite, montmorillonite, bentonite, silica, chitin, titanium dioxide, nano clay, and mixtures thereof.
8 . The retort food pouch of claim 7 , wherein the polyhydroxyalkanoate in the barrier layer comprises poly-3-hydroxybutyrate-co-3-hydroxyhexanaote (P3HB-co-P3HHx).
9 . The retort food pouch of claim 7 , wherein the barrier layer comprises from about 1.0 to about 15.0 weight percent of at least one polyhydroxyalkanoate comprising from about 25 to about 50 mole percent monomer residues of a 3-hydroxyalkanoate selected from the group consisting of 3-hydroxyvalerate, 3-hydroxyhexanoate, 3-hydroxyoctanoate, 3-hydroxydecanoate, and mixtures thereof.
10 . The retort food pouch of claim 7 , wherein the barrier layer comprises a polyhydroxyalkanoate terpolymer made up from about 75 to about 99.9 mole percent monomer residues of 3-hydroxybutyrate, from about 0.1 to about 25 mole percent monomer residues of 3-hydroxyhexanoate, and from about 0.1 to about 25 mole percent monomer residues of a third 3-hydoxyalkanoate selected from the group consisting of 3-hydroxyoctanoate, 3-hydroxydecanoate, and mixtures thereof.
11 . The retort food pouch of claim 7 , wherein the barrier layer comprises polyhydroxyalkanoates having a weight average molecular weight from about 50 thousand Daltons to about 2.5 million Daltons as determined by ASTM D5296-05.
12 . The retort food pouch of claim 1 , wherein the barrier layer comprises aluminum.
13 . The retort food pouch of claim 1 , wherein the multi-layer structure has an overall thickness of from about 25 to about 75 microns.
14 . The retort food pouch of claim 1 , wherein the aluminum barrier layer has a thickness of from about 3 to about 13 microns.
15 . The retort food pouch of claim 1 , wherein the multi-layer structure comprises a biaxially oriented nylon layer, having a thickness from about 5 to about 15 microns.
16 . The retort food pouch of claim 1 , wherein the biodegradable printed layer comprises:
from about 10 to about 99 weight percent polyhydroxyalkanoates;
from about 1 to 90 weight percent of at least one biodegradable polymer selected from the group consisting of polybutylene succinate, polycaprolactone, polybutylene succinate-co-butylene adipate, polybutylene adipate-co-terephthalate, polylactic acid, cellulose acetate, and mixtures thereof;
from about 0.1 weight percent to about 5 weight percent of at least one nucleating agent selected from the group consisting of erythritols, pentaerythritol, dipentaerythritols, artificial sweeteners, stearates, sorbitols, mannitols, inositols, polyester waxes, nanoclays, behenamide, erucamide, stearamide, oleamide, polyhydroxybutyrate, boron nitride, and mixtures thereof; and
optionally, from about 1 to about 25 weight percent of at least one filler selected from the group consisting of clays, calcium carbonate, talc, kaolinite, montmorillonite, bentonite, silica, chitin, titanium dioxide, nano clay, and mixtures thereof.
17 . The retort food pouch of claim 1 , wherein the biodegradable, printed layer comprises a core sub-layer and at least one skin sub-layer.
18 . The retort food pouch of claim 16 , wherein the polyhydroxyalkanoate in the biodegradable printed layer comprises poly-3-hydroxybutyrate-co-3-hydroxyhexanaote (P3HB-co-P3HHx).
19 . The retort food pouch of claim 16 , wherein the biodegradable printed layer comprises from about 1.0 to about 15.0 weight percent of at least one polyhydroxyalkanoate comprising from about 25 to about 50 mole percent monomer residues of a 3-hydroxyalkanoate selected from the group consisting of 3-hydroxyvalerate, 3-hydroxyhexanoate, 3-hydroxyoctanoate, 3-hydroxydecanoate, and mixtures thereof.
20 . The retort food pouch of claim 16 , wherein the biodegradable printed layer comprises a polyhydroxyalkanoate terpolymer made up from about 75 to about 99.9 mole percent monomer residues of 3-hydroxybutyrate, from about 0.1 to about 25 mole percent monomer residues of 3-hydroxyhexanoate, and from about 0.1 to about 25 mole percent monomer residues of a third 3-hydroxyalkanoate selected from the group consisting of 3-hydroxyvalerate, 3-hydroxyoctanoate, 3-hydroxydecanoate, and mixtures thereof.
21 . The retort food pouch of claim 16 , wherein the biodegradable printed layer comprises polyhydroxyalkanoates having a weight average molecular weight from about 50 thousand Daltons to about 2.5 million Daltons as determined by ASTM D 5296-05.
22 . The retort food pouch of claim 1 , wherein the biodegradable printed layer has a thickness from about 5 to about 25 microns.
23 . The retort food pouch of claim 1 , wherein the biodegradable printed layer is printed using a flexographic, gravure, or digital printing method.
24 . The retort food pouch of claim 1 , wherein the layers are adhered together with at least one adhesive which comprises at least one polymer selected from the group consisting of polycaprolactone, isocyanates, polyurethanes, polybutylene succinate-co-adipate, polybutylene adipate-co-terephthalate, polyhydroxyalkanoates, polylactic acid, and mixtures thereof.
25 . The retort food pouch of claim 1 , wherein all the layers of the multi-layer structure have a melting point greater than 120° C. as determined by ASTM E794-06.
26 . The retort food pouch of claim 1 , wherein the retort food pouch has a shelf-life of at least 18 months, as determined by ASTM E2454.
27 . The retort food pouch of claim 1 , wherein the multi-layer structure has an oxygen transmission rate of less than 0.45 ml/m 2 /24 h, as determined according to ASTM D3985.
28 . The retort food pouch of claim 1 , wherein the multi-layer structure has a water vapor transmission rate of less than 0.2 g/m 2 /24 h, according to ASTM F1249.