JP2024519598A - Home compostable and degradable extrusion coated substrates - Google Patents

Abstract

The present disclosure provides a home compostable extrusion coated substrate comprising a paperboard substrate having at least a first side and a layer of extrusion coating applied over at least a portion of the first side, the extrusion coating being comprised of from about 30 to about 99.5 weight percent of at least one poly(hydroxyalkanoate) and from about 5 weight percent to about 69.5 weight percent of at least one compostable polymer selected from the group consisting of poly(lactic acid), poly(caprolactone), poly(ethylene sebicate), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(butylene adipate terephthalate), and mixtures thereof. Preferably, in accordance with the present disclosure, the extrusion coated substrate is also home compostable as determined by ASTM D6868.

Description

The present disclosure relates to compostable polymer compositions. More particularly, the present disclosure relates to home compostable and/or marine degradable substrates having a compostable extrusion coating.

For convenience, consumers frequently use disposable foodservice items, such as plates, bowls, cups, take-out containers, straws, and other eating or drinking utensils. Disposable foodservice items are particularly convenient for serving food at large gatherings of people and for serving food at outdoor dining events.

Disposable food service items may be readily manufactured from substrates such as paperboard, which degrade relatively quickly when composted. However, a simple, uncoated paperboard substrate is generally insufficient to function as a food service item, as the paperboard will rapidly absorb water and/or grease, which ultimately compromises the strength of the paperboard. As a result, food service items manufactured from paperboard are typically coated with a thin polymer layer to improve water and grease resistance.

Coatings made from polymers such as polyethylene (PE), polypropylene (PP), or polyethylene terephthalate (PET) can significantly improve the resistance of paperboard to water and/or grease absorption, but such polymers do not readily degrade when composted.

It would be desirable to provide a new coating for food service items that is completely home compostable, especially if this compostable coating provides good water and grease resistance, i.e., water and grease resistance equivalent to that provided by conventional non-compostable coatings.

These and other needs are met by the home compostable extrusion coated substrates disclosed herein.

In a first aspect, the present disclosure provides a home compostable and/or marine degradable extrusion coated substrate. According to one embodiment, the extrusion coated substrate includes a paperboard substrate having at least a first surface. The extrusion coated substrate also includes a layer of extrusion coating applied over at least a portion of the first surface. The extrusion coating is comprised of about 30 to about 99.5 weight percent of at least one poly(hydroxyalkanoate) and about 5 weight percent to about 69.5 weight percent of at least one compostable polymer selected from the group consisting of poly(lactic acid), poly(caprolactone), poly(ethylene sebacate), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(butylene adipate terephthalate), and mixtures thereof.

According to certain aspects, the extrusion coating is preferably comprised of about 50 to about 69.5 weight percent of at least one poly(hydroxyalkanoate).

Further, according to some embodiments, the at least one poly(hydroxyalkanoate) preferably comprises poly-3-hydroxybutyrate-co-3-hydroxyhexanoate ("P(3HB-co-3HHx)"). More particularly, in certain embodiments, P
(3HB-co-3HHx) is preferably composed of about 75 to about 99 mole percent hydroxybutyrate and about 1 to about 25 mole percent hydroxyhexanoate. More preferably, P(3HB-co-3HHx) is preferably composed of about 93 to about 98 mole percent hydroxybutyrate and about 2 to about 7 mole percent hydroxyhexanoate.

In another aspect, the extrusion coating is preferably comprised of about 1 to about 25 weight percent of at least one polyhydroxyalkanoate, including about 25 to about 50 mole percent of hydroxyvalerate, hydroxyhexanoate, hydroxyoctanoate, and/or hydroxydecanoate.

Furthermore, in some cases, at least one poly(hydroxyalkanoate) is preferably a terpolymer composed of about 75 to about 99.9 mole percent monomer residues of 3-hydroxybutyrate, about 0.1 to about 25 mole percent monomer residues of 3-hydroxyhexanoate, and about 0.1 to about 25 mole percent monomer residues of a third 3-hydroxyalkanoate having 5 to 12 carbon atoms.

In certain embodiments, the at least one poly(hydroxyalkanoate) preferably has a weight average molecular weight, as determined by ASTM D5296-05, of about 50,000 Daltons to about 2.5 million Daltons. More preferably, the at least one poly(hydroxyalkanoate) has a weight average molecular weight, as determined by ASTM D5296-05, of about 500,000 Daltons to about 750,000 Daltons.

In addition to poly(hydroxyalkanoate), the extrusion coating may optionally include an additional compostable polymer. In some aspects, the extrusion coating preferably includes from about 30.5 weight percent to about 49.5 weight percent of at least one compostable polymer selected from the group consisting of poly(lactic acid), poly(caprolactone), poly(ethylene sebacate), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(butylene adipate terephthalate), poly(vinyl acetate), and mixtures of any thereof. More preferably, the compostable polymer is comprised of poly(lactic acid).

The extrusion coating may also include small amounts of various additives. For example, in certain embodiments, the extrusion coating preferably also includes from about 0.05 weight percent to about 10 weight percent of at least one rheology modifier selected from the group consisting of vinyl acetate homopolymers or copolymers, peroxides, epoxides, isocyanates, carbodiimides, and mixtures thereof.

According to certain aspects, it is also preferred that the extrusion coating comprises from about 0.1 weight percent to about 10 weight percent of at least one nucleating agent from the group consisting of pentaerythritol, boron nitride, poly(hydroxybutyrate), inositol, clay, dipentaerythritol, sorbitol, and mixtures thereof.

In some embodiments, the extrusion coating preferably comprises from about 1 weight percent to about 15 weight percent of at least one filler selected from the group consisting of aragonite, clay, calcium carbonate, cellulose, nanocellulose, talc, kaolinite, montmorillonite, bentonite, silica, chitin, starch, diatomaceous earth, titanium dioxide, nanoclay, mica, and mixtures thereof.

In some aspects, the extrusion coating also comprises from about 0.1 weight percent to about 50 weight percent of: (1) 2-(hydroxymethyl)-2-ethylpropane-1,3-diol (TMP), diethylene glycol, ethylene glycol, 1,6 hexanediol, 2,2 dimethyl 1,3 propanediol (NPG), 1,4 butanediol, 1,3 propanediol, 1,2 propanediol, propane-1,2,3-triol (glycerin), 2-methyl 1,3 propanediol (MPD), and silyl glycerol. and (2) at least one impact modifier which is a polycondensation reaction product of a glycol selected from the group consisting of cyclohexanedimethanol, and a carboxylic acid selected from the group consisting of 1,6 hexanedioic acid (adipic acid), 1,12 dodecanedioic acid (DDDA), sebacic acid, azelaic acid, cyclohexanedioic acid (CHDA), 1,2 benzenedicarboxylic acid (phthalic anhydride), 1,3 benzenedicarboxylic acid (isophthalic acid), 1,3 benzenedicarboxylic acid (terephthalic acid), and 1,4 butanedioic acid (succinic acid).

In another embodiment, the impact modifier may include a polyester composed of at least three different types of monomer residues derived from: (1) isosorbide; (2) succinic acid or anhydride; and (3) 1,3-propanediol.

According to certain aspects, the extrusion coating preferably exhibits a melt flow rate of about 3-10 g/10 min at 190°C/2.16 kg as determined by ASTM D1238-13.

Preferably, the extrusion coating is applied onto the first side of the substrate at a coating weight of about 10 to about 50 grams per square meter.

Preferably, the paperboard substrate is comprised of kraft paperboard, solid unbleached paperboard, solid bleached sulfate (SBS) paperboard, or corrugated paperboard.

Furthermore, in some cases, the extrusion coated substrate is preferably formed into a cup, plate, straw or food container. The properties of the extrusion coating have been found to be well suited for such food service uses.

In some cases, the coating preferably exhibits a Cobb Water Absorption value of less than 30 grams per square meter, as measured according to TAPPI Standard T441. Additionally, the coating preferably exhibits a Kit Test Grease Resistance value of greater than 5, as measured according to TAPPI Standard T559. The coating also preferably exhibits a Dyne value of greater than 38, as measured according to ASTM D2578-04a.

In accordance with the present disclosure, it is also preferred that the extrusion coated substrate be home compostable as determined by ASTM D6868 and/or marine degradable as determined by ASTM D6691-17.

The present disclosure provides, for the first time, a home compostable and/or marine degradable extrusion coated substrate.

The substrate is typically a paper or paperboard web. Preferably, the paper or paperboard for the substrate comprises kraft paperboard, solid unbleached paperboard, solid bleached sulfate (SBS) paperboard, or corrugated paper. The basis weight of the paper or paperboard substrate is typically at least 400 grams per square meter (gsm), more preferably from about 100 gsm to about 400 gsm. The paperboard substrate typically has a caliper of from about 1 pt to about 46 pt (about 0.03 mm to about 1.17 mm), more preferably from about 5 pt to about 20 pt (about 0.17 mm to about 0.51 mm).

The paperboard substrate includes a first side and a second side. At least the first side of the substrate is coated with an extrusion coating. In some embodiments, both the first side and the second side of the substrate are coated with an extrusion coating.

The extrusion coating applied to the first and optionally second sides of the substrate according to the present disclosure is preferably home compostable as defined by ASTM D6868. Preferably, the extrusion coating is also biodegradable as defined by ASTM standard D5988.

Generally, the extrusion coating comprises at least one compostable poly(hydroxyalkanoate) and at least one additional compostable polymer selected from the group consisting of poly(lactic acid), poly(caprolactone), poly(ethylene sebicate), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(butylene adipate terephthalate), and mixtures thereof.

The amount of at least one poly(hydroxyalkanoate) in the extrusion coating is generally from about 30 to about 99.5 weight percent of the extrusion coating. More preferably, the extrusion coating is preferably composed of from about 50 to about 69.5 weight percent of at least one poly(hydroxyalkanoate).

A wide variety of one poly(hydroxyalkanoates) may be incorporated into the extrusion coating. In some cases, the at least one poly(hydroxyalkanoate) preferably comprises poly-3-hydroxybutyrate-co-3-hydroxyhexanoate ("P(3HB-co-3HHx)"). More preferably, in certain embodiments, the P(3HB-co-3HHx) preferably comprises from about 75 to about 99 mole percent hydroxybutyrate and from about 1 to about 25 mole percent hydroxyhexanoate. Even more preferably, the P(3HB-co-3HHx) comprises from about 93 to about 98 mole percent hydroxybutyrate and from about 2 to about 7 mole percent hydroxyhexanoate.

In other aspects, the poly(hydroxyalkanoates) may contain larger monomer units. Thus, in some aspects, the extrusion coating preferably contains from about 1 to about 25 weight percent of at least one polyhydroxyalkanoate, including from about 25 to about 50 mole percent of hydroxyvalerate, hydroxyhexanoate, hydroxyoctanoate, and/or hydroxydecanoate.

In yet other embodiments, the poly(hydroxyalkanoates) may comprise terpolymers. For example, in certain embodiments, at least one poly(hydroxyalkanoate) is preferably a terpolymer comprising 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 having 5 to 12 carbon atoms.

The weight average molecular weight of the at least one poly(hydroxyalkanoate) will preferably range from about 50,000 daltons to about 2.5 million daltons, as determined by ASTM D5296-05. More preferably, the at least one poly(hydroxyalkanoate) has a weight average molecular weight of about 500,000 daltons to about 750,000 daltons, as determined by ASTM D5296-05.

In addition to the poly(hydroxyalkanoate), the extrusion coating also includes at least one compostable polymer selected from the group consisting of poly(lactic acid), poly(caprolactone), poly(ethylene sebicate), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(butylene adipate terephthalate), and mixtures thereof.

Generally, the extrusion coating comprises from about 5 weight percent to about 69.5 weight percent of the additional compostable polymer. The extrusion coating may optionally comprise additional compostable polymers. In some embodiments, the extrusion coating more preferably comprises from about 30.5 weight percent to about 49.5 weight percent of at least one compostable polymer.

In general, the additional compostable polymer may be selected from the group consisting of poly(lactic acid), poly(caprolactone), poly(ethylene sebecate), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(butylene adipate terephthalate), and mixtures thereof. However, in certain embodiments, the compostable polymer more preferably comprises poly(lactic acid). In other words, the extrusion coating is a blend of poly(lactic acid) and one or more poly(hydroxyalkanoates).

Generally, extrusion coatings may also include small amounts of various additives. In some cases, for example, the extrusion coating also includes about 0.05 weight percent to about 10 weight percent of at least one rheology modifier selected from the group consisting of vinyl acetate homopolymers or copolymers, peroxides, epoxides, isocyanates, carbodiimides, and mixtures thereof.

In certain embodiments, the extrusion coating also preferably comprises from about 0.1 weight percent to about 10 weight percent of at least one nucleating agent from the group consisting of pentaerythritol, boron nitride, poly(hydroxybutyrate), inositol, clay, dipentaerythritol, sorbitol, and mixtures thereof.

Additionally, the extrusion coating may also include about 1 weight percent to about 15 weight percent of at least one filler selected from the group consisting of aragonite, clay, calcium carbonate, cellulose, nanocellulose, talc, kaolinite, montmorillonite, bentonite, silica, chitin, starch, diatomaceous earth, titanium dioxide, nanoclay, mica, and mixtures thereof.

In some embodiments, the extrusion coating may also include from about 0.1 weight percent to about 50 weight percent of at least one impact modifier. In some embodiments, the impact modifier is preferably selected from the group consisting of (1) 2-(hydroxymethyl)-2-ethylpropane-1,3-diol (TMP), diethylene glycol, ethylene glycol, 1,6 hexanediol, 2,2 dimethyl 1,3 propanediol (NPG), 1,4 butanediol, 1,3 propanediol, 1,2 propanediol, propane-1,2,3-triol (glycerin), 2-methyl 1,3 propanediol (MPD), and cyclohexanediamine. (2) a compostable polymer that is a polycondensation reaction product of a glycol selected from the group consisting of 1,6 hexanedioic acid (adipic acid), 1,12 dodecanedioic acid (DDDA), sebacic acid, azelaic acid, cyclohexanedioic acid (CHDA), 1,2 benzenedicarboxylic acid (phthalic anhydride), 1,3 benzenedicarboxylic acid (isophthalic acid), 1,3 benzenedicarboxylic acid (terephthalic acid), and 1,4 butanedioic acid (succinic acid).

The extrusion coated substrate is formed by first providing a charge of extrusion coating polymer mixture. Typically, the components of the extrusion coating are precombined and provided in the form of pelletized resin. This charge of polymer resin is heated in an extruder to a temperature above the melting point of the polymer resin. The exact temperature to which the polymer resin is heated may vary somewhat depending on the exact makeup of the polymer resin (type of compostable polymer, molecular weight of the compostable polymer, amount of additives, etc.). Generally, the polymer resin is heated to a temperature of from about 125°C to about 280°C, more preferably from about 135°C to about 200°C.

Once heated, the polymeric resin charge is then extruded through a die and applied onto a first surface of a substrate. Optionally, a coating may also be applied onto a second surface of the substrate using a substantially similar process.

According to certain aspects, the extrusion coating preferably exhibits a melt flow rate of about 3-10 g/10 min at 190°C/2.16 kg as determined by ASTM D1238-13.

Preferably, the extrusion coating is applied onto the first side of the substrate at a coating weight of about 10 to about 50 grams per square meter.

After the extrusion coating is applied, the finished substrate according to the present disclosure may be used to form a variety of end products. The extrusion coated substrate is particularly well suited for conversion to form food service items. For example, the extrusion coated substrate may be formed into a cup, plate, or food container. In other aspects, the extrusion coated substrate may be converted to form a carton, bottle, straw, box, or container.

Again, the extrusion coated substrates according to the present disclosure are well suited for use in food applications. In particular, the coated substrates exhibit good resistance to oil, grease and water.

Thus, the extrusion coated substrate of the present disclosure preferably exhibits a Cobb Water Absorption value of less than 30 grams per square meter, as measured according to TAPPI Standard T441. Additionally, the extrusion coated substrate preferably exhibits a Kit Test Grease Resistance value of greater than 5, as measured according to TAPPI Standard T559. Additionally, the extrusion coated substrate also preferably exhibits a Dyne value of greater than 38, as measured according to ASTM D2578-04a.

At the same time, the extrusion coated substrates of the present disclosure are home compostable, unlike substrates coated with conventional petroleum-based polymers. In accordance with the present disclosure, the extrusion coated substrates are also preferably home compostable as determined by ASTM D6868 and/or marine degradable as determined by ASTM D6691-17.

The present disclosure is further exemplified by the following aspects:

Aspect 1. A home compostable and/or marine degradable extrusion coated substrate comprising:

A paperboard substrate having a first surface;

A layer of extrusion coating applied over at least a portion of the first surface, the extrusion coating being

30-99.5% by weight of at least one poly(hydroxyalkanoate),

5 weight percent to 69.5 weight percent of poly(lactic acid), poly(caprolactone), poly(ethylene sebecate), poly(butylene succinate)
and a layer of extrusion coating comprising at least one compostable polymer selected from the group consisting of poly(butylene succinate-co-adipate), poly(butylene adipate terephthalate), and mixtures thereof.

Aspect 2. The extrusion coated substrate of aspect 1, wherein the extrusion coating comprises 50 to 69.5 weight percent of at least one poly(hydroxyalkanoate).

Aspect 3. The extrusion coated substrate of aspect 1 or 2, wherein the at least one poly(hydroxyalkanoate) comprises poly-3-hydroxybutyrate-co-3-hydroxyhexanoate ("P(3HB-co-3HHx)").

Aspect 4. The extrusion coated substrate of aspect 3, wherein P(3HB-co-3HHx) comprises 75 to 99 mole percent hydroxybutyrate and 1 to 25 mole percent hydroxyhexanoate.

Aspect 5. The extrusion coated substrate of aspect 3, wherein P(3HB-co-3HHx) preferably comprises 93 to 98 mole percent hydroxybutyrate and 2 to 7 mole percent hydroxyhexanoate.

Aspect 6. The extrusion coated substrate of any of the preceding aspects, wherein the extrusion coating comprises 1 to 25 weight percent of at least one polyhydroxyalkanoate, including 25 to 50 mole percent of hydroxyvalerate, hydroxyhexanoate, hydroxyoctanoate, and/or hydroxydecanoate.

Aspect 7. The extrusion coated substrate of any of the preceding aspects, wherein the at least one poly(hydroxyalkanoate) comprises a terpolymer composed of 75 to 99.9 mole percent monomer residues of 3-hydroxybutyrate, 0.1 to 25 mole percent monomer residues of 3-hydroxyhexanoate, and 0.1 to 25 mole percent monomer residues of a third 3-hydroxyalkanoate having 5 to 12 carbon atoms.

Aspect 8. The extrusion coated substrate of any of the preceding aspects, wherein at least one poly(hydroxyalkanoate) has a weight average molecular weight of 50,000 Daltons to 2.5 million Daltons, as determined by ASTM D5296-05.

Aspect 9. The extrusion coated substrate of any of the preceding aspects, wherein the at least one poly(hydroxyalkanoate) has a weight average molecular weight of 500,000 Daltons to 750,000 Daltons as determined by ASTM D5296-05.

Aspect 10. The extrusion coated substrate of any of the preceding aspects, wherein the extrusion coating comprises 30.5 weight percent to 49.5 weight percent of at least one compostable polymer selected from the group consisting of poly(lactic acid), poly(caprolactone), poly(ethylene sebecate), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(butylene adipate terephthalate), poly(vinyl acetate), and any mixture thereof.

Aspect 11. The extrusion coated substrate of any of the preceding aspects, wherein the at least one compostable polymer comprises poly(lactic acid).

Aspect 12. The extrusion coated substrate of any of the preceding aspects, wherein the extrusion coating further comprises 0.05 weight percent to 10 weight percent of at least one rheology modifier selected from the group consisting of vinyl acetate homopolymers or copolymers, peroxides, epoxides, isocyanates, carbodiimides, and mixtures thereof.

Aspect 13. The extrusion coated substrate of any of the preceding aspects, wherein the extrusion coating further comprises 0.1 weight percent to 10 weight percent of at least one nucleating agent from the group consisting of pentaerythritol, boron nitride, poly(hydroxybutyrate), inositol, clay, dipentaerythritol, sorbitol, and mixtures thereof.

Aspect 14. The extrusion coated substrate of any of the preceding aspects, wherein the extrusion coating further comprises 1 weight percent to 15 weight percent of at least one filler selected from the group consisting of aragonite, clay, calcium carbonate, cellulose, nanocellulose, talc, kaolinite, montmorillonite, bentonite, silica, chitin, starch, diatomaceous earth, titanium dioxide, nanoclay, mica, and mixtures thereof.

Aspect 15. The extrusion coating comprises from 0.1 weight percent to 50 weight percent of a glycerol selected from the group consisting of (1) 2-(hydroxymethyl)-2-ethylpropane-1,3-diol (TMP), diethylene glycol, ethylene glycol, 1,6 hexanediol, 2,2 dimethyl 1,3 propanediol (NPG), 1,4 butanediol, 1,3 propanediol, 1,2 propanediol, propane-1,2,3-triol (glycerin), 2-methyl 1,3 propanediol (MPD), and cyclohexanedimethanol. and (2) at least one impact modifier that is a polycondensation reaction product of a glycol selected from the group consisting of 1,6 hexanedioic acid (adipic acid), 1,12 dodecanedioic acid (DDDA), sebacic acid, azelaic acid, cyclohexanedioic acid (CHDA), 1,2 benzenedicarboxylic acid (phthalic anhydride), 1,3 benzenedicarboxylic acid (isophthalic acid), 1,3 benzenedicarboxylic acid (terephthalic acid), and 1,4 butanedioic acid (succinic acid).

Aspect 16. The extrusion coated substrate of any of the preceding aspects, wherein the extrusion coating exhibits a melt flow rate of 3 to 10 g/10 min at 190°C/2.16 kg as determined by ASTM D1238-13.

Aspect 17. The extrusion coated substrate of any of the preceding aspects, wherein the extrusion coating is applied onto the first side of the substrate at a coating weight of 10 to 50 grams per square meter.

Aspect 18. The extrusion coated substrate of any of the preceding aspects, wherein the paperboard substrate comprises kraft paperboard, solid unbleached paperboard, solid bleached sulfate (SBS) paperboard, or corrugated paperboard.

Aspect 19. The extrusion coated substrate of any of the preceding aspects, wherein the extrusion coated substrate is formed into a cup, plate, straw, or food container.

Aspect 20. The extrusion coated substrate of any of the preceding aspects, wherein the extrusion coating exhibits a Cobb water absorption value of less than 30 grams per square meter, as measured according to TAPPI standard T441.

Aspect 21. The extrusion coated substrate of any of the preceding aspects, wherein the extrusion coating exhibits a Kit Test grease resistance value of greater than 5, as measured according to TAPPI standard T559.

Aspect 22. The coating has a hardness of 38, as measured according to ASTM D2578-04a.
3. The extrusion coated substrate of any of the preceding aspects, wherein the substrate exhibits a Dyne value of greater than

Aspect 23. The extrusion coated substrate of any of the preceding aspects, wherein the extrusion coated substrate is home compostable as determined by ASTM D6868.

Aspect 24. The extrusion coated substrate of any of the preceding aspects, wherein the extrusion coated substrate is marine degradable as determined by ASTM D6691-17.

The following non-limiting examples illustrate various additional aspects of the present invention. Unless otherwise indicated, temperatures are in degrees Celsius and percentages are by weight based on the dry weight of the formulation.

Example 1

In a 40 mm extruder, a mixture of 58.9% 6 mol% PHA, 40% polylactic acid, 0.1% 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, and 1% boron nitride was fed into the extruder through a feeder. After melting, the mixture was extruded through a die, chopped, and cooled to form multiple resin pellets for subsequent coating of substrates.

Example 2

In a 40 mm extruder, a mixture of 58.9% 6 mol% PHA, 40% polybutylene succinate coadipate (PBSA), 0.1% 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, and 1% boron nitride was charged through a feeder into the extruder. After melting, the mixture was extruded through a die, chopped, and cooled to form multiple resin pellets for subsequent coating of substrates.

Example 3

In a 40 mm extruder, a mixture of 58.9% 6 mol% PHA, 20% polybutylene adipate co-terephthalate (PBAT), 20% polylactic acid, 0.1% 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, and 1% boron nitride was fed into the extruder through a feeder. After melting, the mixture was extruded through a die, chopped, and cooled to form multiple resin pellets for subsequent coating of substrates.

Example 4

In a 40 mm extruder, 79.9% of 2 mol% PHA, 10% polybutylene adipate co-terephthalate (PBAT), 10% polylactic acid, 10% polycaprolactone, and 0.1% 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane were charged through a feeder into the extruder. After melting, the mixture was extruded through a die, chopped, and cooled to form multiple resin pellets for subsequent coating of substrates.

Example 5

In a 40 mm extruder, 79.9% of 2 mol% PHA, 20% polybutylene adipate co-terephthalate (PBAT), and 0.1% 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane were charged through a feeder into the extruder. After melting, the mixture was extruded through a die, chopped, and cooled to form multiple resin pellets for subsequent coating of substrates.

Example 6

In a 40 mm extruder, 79.9% of 2 mol% PHA, 20% polycaprolactone, and 0.1% 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane were charged through a feeder into the extruder. After melting, the mixture was extruded through a die, chopped, and cooled to form multiple resin pellets for subsequent coating of substrates.

Example 7

In a 40 mm extruder, a mixture of 58.9% 6 mol% PHA, 40% polylactic acid, 0.1% 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, and 1% pentaerythritol was fed into the extruder through a feeder. After melting, the mixture was extruded through a die, chopped, and cooled to form multiple resin pellets for subsequent coating of substrates.

Example 8

In a 40 mm extruder, a mixture of 58.9% 2 mol% PHA, 40% polylactic acid, 0.1% 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, and 1% pentaerythritol was charged through a feeder into the extruder. After melting, the mixture was extruded through a die, chopped, and cooled to form multiple resin pellets for subsequent coating of substrates.

Example 9

A 40 mm extruder was charged with a mixture of 59% 6 mol% PHA, 36% polylactic acid, 1% boron nitride, and 4% polyvinyl alcohol through a feeder. After melting, the mixture was extruded through a die, cut, and cooled to form multiple resin pellets for subsequent coating of substrates.

Example 10

The polymer of Example 1 was applied to light paper using a curtain coater at a coating thickness of 15 lbs/ream. The subsequent coating shows ease of application and good adhesion verified by 100% fiber tear without additional surface preparation such as flame or corona treatment. Additionally, the coating shows a Cobb test value of 0.17-0.21, a Kit test value of 10+, and a Dyne value of 42-44.

Example 11

The polymer of Example 1 was applied to light weight paper using a curtain coater at a coating thickness of 12 lbs/ream. Subsequent coatings show ease of application and good adhesion verified by 100% fiber tear without additional surface preparation such as flame or corona treatment.

Example 12

The polymer of Example 1 was applied to light weight paper using a curtain coater at a coating thickness of 9 lbs/ream. Subsequent coatings show ease of application and good adhesion verified by 100% fiber tear without additional surface preparation such as flame or corona treatment.

Example 13

The polymer of Example 1 was applied to light weight paper using a curtain coater at a coating thickness of 6 lbs/ream. Subsequent coatings show ease of application and good adhesion verified by 100% fiber tear without additional surface preparation such as flame or corona treatment.

Example 14

The polymer of Example 9 was applied to light weight paper using a curtain coater at a coating thickness of 15 lbs/ream. Subsequent coatings show ease of application and good adhesion verified by 100% fiber tear without additional surface preparation such as flame or corona treatment.

Example 15

The polymer of Example 9 was applied to light weight paper using a curtain coater at a coating thickness of 12 lbs/ream. Subsequent coatings show ease of application and good adhesion verified by 100% fiber tear without additional surface preparation such as flame or corona treatment.

Example 16

The polymer of Example 9 was applied to light weight paper using a curtain coater at a coating thickness of 9 lbs/ream. Subsequent coatings show ease of application and good adhesion verified by 100% fiber tear without additional surface preparation such as flame or corona treatment.

Example 17

The polymer of Example 9 was applied to light weight paper using a curtain coater at a coating thickness of 6 lbs/ream. Subsequent coatings show ease of application and good adhesion verified by 100% fiber tear without additional surface preparation such as flame or corona treatment.

The foregoing description of preferred embodiments of the present invention has been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments have been chosen and described to provide the best illustration of the principles of the invention and its practical application, thereby enabling those skilled in the art to use the invention in various embodiments and with various modifications as suited to the particular use contemplated. All such modifications or variations are within the scope of the invention, as determined by the appended claims, when interpreted in accordance with the breadth to which they are fairly, legally, and equitably authorized.

Claims (24)

1. A home compostable and/or marine degradable extrusion coated substrate comprising:
a paperboard substrate having a first surface;
a layer of extrusion coating applied over at least a portion of the first surface, the extrusion coating comprising 30 to 99.5 weight percent of at least one poly(hydroxyalkanoate);
and a layer of extrusion coating comprising 5 weight percent to 69.5 weight percent of at least one compostable polymer selected from the group consisting of poly(lactic acid), poly(caprolactone), poly(ethylene sebecate), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(butylene adipate terephthalate), and mixtures thereof. The extrusion coated substrate of claim 1, wherein the extrusion coating comprises 50 to 69.5 weight percent of at least one poly(hydroxyalkanoate). The extrusion coated substrate of claim 1, wherein the at least one poly(hydroxyalkanoate) comprises poly-3-hydroxybutyrate-co-3-hydroxyhexanoate ("P(3HB-co-3HHx)"). The extrusion coated substrate of claim 3, wherein P(3HB-co-3HHx) comprises 75 to 99 mole percent hydroxybutyrate and 1 to 25 mole percent hydroxyhexanoate. The extrusion coated substrate of claim 3, wherein P(3HB-co-3HHx) preferably contains 93 to 98 mole percent hydroxybutyrate and 2 to 7 mole percent hydroxyhexanoate. The extrusion coated substrate of claim 1, wherein the extrusion coating comprises 1 to 25 weight percent of at least one polyhydroxyalkanoate, including 25 to 50 mole percent of hydroxyvalerate, hydroxyhexanoate, hydroxyoctanoate, and/or hydroxydecanoate. The extrusion coated substrate of claim 1, wherein the at least one poly(hydroxyalkanoate) comprises a terpolymer composed of 75 to 99.9 mole percent monomer residues of 3-hydroxybutyrate, 0.1 to 25 mole percent monomer residues of 3-hydroxyhexanoate, and 0.1 to 25 mole percent monomer residues of a third 3-hydroxyalkanoate having 5 to 12 carbon atoms. The extrusion coated substrate of claim 1, wherein at least one poly(hydroxyalkanoate) has a weight average molecular weight of 50,000 Daltons to 2.5 million Daltons as determined by ASTM D5296-05. The extrusion coated substrate of claim 1, wherein at least one poly(hydroxyalkanoate) has a weight average molecular weight of 500,000 Daltons to 750,000 Daltons as determined by ASTM D5296-05. The extrusion coated substrate of claim 1, wherein the extrusion coating comprises 30.5 weight percent to 49.5 weight percent of at least one compostable polymer selected from the group consisting of poly(lactic acid), poly(caprolactone), poly(ethylene sebecate), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(butylene adipate terephthalate), poly(vinyl acetate), and mixtures of any thereof. The extrusion coated substrate of claim 1, wherein the at least one compostable polymer comprises poly(lactic acid). The extrusion coated substrate of claim 1, wherein the extrusion coating further comprises 0.05 weight percent to 10 weight percent of at least one rheology modifier selected from the group consisting of vinyl acetate homopolymers or copolymers, peroxides, epoxides, isocyanates, carbodiimides, and mixtures thereof. The extrusion coated substrate of claim 1, wherein the extrusion coating further comprises 0.1 weight percent to 10 weight percent of at least one nucleating agent from the group consisting of pentaerythritol, boron nitride, poly(hydroxybutyrate), inositol, clay, dipentaerythritol, sorbitol, and mixtures thereof. The extrusion coated substrate of claim 1, wherein the extrusion coating further comprises 1 weight percent to 15 weight percent of at least one filler selected from the group consisting of aragonite, clay, calcium carbonate, cellulose, nanocellulose, talc, kaolinite, montmorillonite, bentonite, silica, chitin, starch, diatomaceous earth, titanium dioxide, nanoclay, mica, and mixtures thereof. The extrusion coating comprises 0.1 weight percent to 50 weight percent of the group consisting of (1) 2-(hydroxymethyl)-2-ethylpropane-1,3-diol (TMP), diethylene glycol, ethylene glycol, 1,6 hexanediol, 2,2 dimethyl 1,3 propanediol (NPG), 1,4 butanediol, 1,3 propanediol, 1,2 propanediol, propane-1,2,3-triol (glycerin), 2-methyl 1,3 propanediol (MPD), and cyclohexanedimethanol. 10. The extrusion coated substrate of claim 1, further comprising at least one impact modifier that is a polycondensation reaction product of a glycol selected from the group consisting of 1,6 hexanedioic acid (adipic acid), 1,12 dodecanedioic acid (DDDA), sebacic acid, azelaic acid, cyclohexanedioic acid (CHDA), 1,2 benzenedicarboxylic acid (phthalic anhydride), 1,3 benzenedicarboxylic acid (isophthalic acid), 1,3 benzenedicarboxylic acid (terephthalic acid), and 1,4 butanedioic acid (succinic acid). The extrusion coated substrate of claim 1, wherein the extrusion coating exhibits a melt flow rate of 3 to 10 g/10 min at 190°C/2.16 kg as determined by ASTM D1238-13. The extrusion coated substrate of claim 1, wherein the extrusion coating is applied onto the first side of the substrate at a coating weight of 10 to 50 grams per square meter. The extrusion coated substrate of claim 1, wherein the paperboard substrate comprises kraft paperboard, solid unbleached paperboard, solid bleached sulfate (SBS) paperboard, or corrugated paperboard. The extrusion coated substrate of claim 1, wherein the extrusion coated substrate is formed into a cup, plate, straw, or food container. The extrusion coated substrate of claim 1, wherein the extrusion coating exhibits a Cobb water absorption value of less than 30 grams per square meter, measured according to TAPPI standard T441. The extrusion coated substrate of claim 1, wherein the extrusion coating exhibits a Kit Test grease resistance value of greater than 5, measured according to TAPPI standard T559. The extrusion coated substrate of claim 1, wherein the coating exhibits a Dyne value of greater than 38, measured according to ASTM D2578-04a. The extrusion coated substrate of claim 1, wherein the extrusion coated substrate is home compostable as determined by ASTM D6868. The extrusion coated substrate of claim 1, wherein the extrusion coated substrate is marine degradable as determined by ASTM D6691-17.