阅读说明：本技术 可生物降解的组合物 (Biodegradable compositions ) 是由 A·邓达尔·菲尔德 于 2020-02-26 设计创作，主要内容包括：本发明提供了组合物,其包含所述组合物的总重量中的量为50-90重量％的海藻提取物、量为10-40重量％的水溶性纤维素衍生物和量为1-20重量％的水。本发明还提供由组合物形成的产品,包括包装材料,溶解、堆肥和生物降解组合物或产品的方法,生产组合物和产品的方法,以及再加工组合物的方法。(The present invention provides a composition comprising a seaweed extract in an amount of 50-90 wt%, a water-soluble cellulose derivative in an amount of 10-40 wt% and water in an amount of 1-20 wt% of the total weight of the composition. The invention also provides products formed from the compositions, including packaging materials, methods of dissolving, composting, and biodegrading the compositions or products, methods of producing the compositions and products, and methods of reprocessing the compositions.)

1. Composition comprising a seaweed extract in an amount of 50-90 wt%, a water-soluble cellulose derivative in an amount of 10-40 wt% and water in an amount of 1-20 wt% of the total weight of the composition.

2. The composition as claimed in claim 1, wherein the seaweed extract is contained in an amount of 60-85 wt%, the water-soluble cellulose derivative is contained in an amount of 10-35 wt%, and the water is contained in an amount of 2-15 wt%.

3. The composition of claim 1 or claim 2, wherein the composition consists essentially of the seaweed extract, the water-soluble cellulose derivative, and water.

4. The composition of any one of claims 1 to 3, wherein the composition consists of the seaweed extract, the water-soluble cellulose derivative and water.

5. The composition according to any one of claims 1 to 4, wherein the weight percentages of the seaweed extract, the water-soluble cellulose derivative and water total 100% by weight of the total weight of the composition.

6. The composition according to any one of claims 1 to 5, wherein the seaweed extract is selected from the group consisting of: carrageenan; agar; and mixtures thereof.

7. The composition of claim 6 wherein the seaweed extract is carrageenan.

8. The composition of claim 7, wherein the carrageenan is Kappa-type carrageenan.

9. The composition according to any one of claims 1 to 8, wherein the composition lacks one or more of the group consisting of: starch; iota-type carrageenan; agar; an alginate; and chitosan.

10. The composition according to any one of claims 1 to 9, wherein the water-soluble cellulose derivative is selected from the group consisting of: methyl Cellulose (MC); hydroxypropylmethylcellulose (HPMC); and mixtures thereof.

11. The composition of claim 10, wherein the water-soluble cellulose derivative is Methylcellulose (MC).

12. The composition of any one of claims 1 to 3 and 6 to 11, wherein the composition further comprises one or more additives.

13. The composition of claim 12, wherein the one or more additives are present at no greater than 10 weight percent of the total weight of the composition.

14. The composition of claim 12 or claim 13, wherein one or more additives are selected from the group consisting of: an inorganic salt; sawdust, paper, hemp fibers; calcium carbonate; glycerol; apple puree; starch; montmorillonite (MMT); cinnamon bark oil; soybean oil; glycerol; glucose; silver nanoparticles; grapefruit seed extract; rosa multiflora essential oil; non-clay or clay minerals; polyethylene glycol (PEG); chitin; arabinoxylan; banana powder; gelatin; titanium oxide nanoparticles; a colorant; and a flavoring agent.

15. The composition of any one of claims 12 to 14, wherein the one or more additives comprise an inorganic salt, and the inorganic salt is a salt of an alkali metal or an alkaline earth metal.

16. The composition of claim 15, wherein the inorganic salt is selected from the group consisting of: a lithium salt; a sodium salt; a calcium salt; and potassium salts.

17. The composition of claim 16, wherein the inorganic salt is potassium chloride.

18. The composition of any one of claims 1 to 17, wherein at a standard thickness of 0.5mm, at least 30% of incident light passes through without absorption or scattering.

19. The product of claim 18, wherein at a standard thickness of 0.5mm, at least 50% of incident light passes through without absorption or scattering.

20. The composition of any one of claims 1 to 19, wherein the composition is fully biodegradable.

21. The composition of claim 20, wherein the composition is fully biodegradable in less than six months in an external, non-industrial environment.

22. The composition of claim 20, wherein the composition is completely biodegradable in an anaerobic atmosphere.

23. The composition according to any one of claims 1 to 22, wherein the composition is fully compostable.

24. The composition of claim 23, wherein the composition is capable of composting in a domestic compost heap of less than six months.

25. The composition of any one of claims 1 to 24, wherein the composition is edible.

26. The composition according to any one of claims 1 to 25, wherein the composition is moldable.

27. The composition of claim 26, wherein the composition is capable of being molded by compression molding, injection molding, or casting.

28. The composition according to any one of claims 1 to 27, wherein the composition is reprocessed after molding.

29. A product formed from the composition of any one of claims 1 to 28.

30. The product of claim 29, wherein the product has a shape selected from the group consisting of: a plate; a planar sheet; a regular sphere; an irregular sphere; a regular spheroid; an irregular spheroid; a regular cube; an irregular cube; a regular cuboid; an irregular cuboid; a regular ellipsoid; an irregular ellipsoid; a regular cylinder; an irregular cylinder; a regular cone; an irregular cone; a regular prism; an irregular prism; a regular pyramid; an irregular pyramid; and any combination thereof.

31. The product of claim 29 or claim 30, wherein the product is selected from the group consisting of: a structural Stock Keeping Unit (SKU); a packaging material; a film; a sheet material; a straw; a pipeline; tampons and applicators; a cutter; a plate; a tray; and a stirrer.

32. The product of claim 31, wherein the product is a packaging material selected from the group consisting of: a container; and components thereof.

33. The product of claim 32, wherein the container or component thereof is selected from the group consisting of: a cup; a tray; shallow basket; a solid clam shell; a box; a bottle; a tube; and a lid.

34. The product of any one of claims 29 to 33, wherein the product is three-dimensional and rigid and load-bearing.

35. The product according to any one of claims 29 to 34, wherein the maximum thickness of the composition in the product is in the range of 0.01mm to 5 mm.

36. The product according to any one of claims 29 to 35, wherein the product or part thereof is translucent.

37. A process for producing the composition of any one of claims 1 to 28, the process comprising the steps of:

(a) contacting the seaweed extract with water to form a seaweed extract hydrogel,

(b) separately contacting a water-soluble cellulose derivative with water to form a water-soluble cellulose derivative solution,

(c) mixing the seaweed extract hydrogel and the water-soluble cellulose derivative solution to form a mixture, and

(d) allowing the mixture to dry to form the composition.

38. The method of claim 37, wherein step (a) comprises: (i) contacting the seaweed extract with water at a temperature in the range of about 5 ℃ to about 40 ℃, and then (ii) heating the mixture of seaweed extract in water to a temperature in the range of about 70 ℃ to about 100 ℃ to form a seaweed extract hydrogel.

39. The process of claim 37 or claim 38, wherein in step (b), the water-soluble cellulose derivative is contacted with water at a temperature of about 70 ℃ to about 100 ℃.

40. The method according to any one of claims 37 to 39, wherein step (c) comprises mixing the seaweed extract solution and the cellulose derivative solution at a temperature of about 70 ℃ to about 100 ℃.

41. A method of producing the product of any one of claims 29 to 36, comprising steps (a) to (d) of the method of producing a composition of claims 37 to 40, and an additional step between steps (c) and (d): forming the mixture into the shape or three-dimensional form of a product.

42. The method of claim 41, wherein the forming step comprises molding.

43. The method of claim 42, wherein the molding comprises compression molding, injection molding, or casting.

44. The method of claim 42 or claim 43, wherein during step (d), the solid composition is carried on at least a portion of a mold used in the molding.

45. A method of reprocessing a biodegradable composition comprising producing a product by the method of any of claims 41 to 44, wherein the method further comprises:

f) softening or melting the product by contacting the product with water or steam to provide a softened product;

g) further processing the softened product to provide a reprocessed product, wherein the reprocessed product has a different shape than the product;

h) drying the reprocessed product to provide a dried reprocessed product.

46. The method of claim 45, wherein the water in step (f) is at a temperature greater than 80 ℃, or is steam.

47. A method according to claim 45 or 46 wherein the operation in step (g) comprises re-working the softened product into the shape of a former or mould.

48. A method according to claim 47, wherein after drying in step (h), the dried shaped product is removed from the former or mould.

49. A method according to any one of claims 44 to 47 wherein the operation in step (g) seals at least the edges or parts of the edges of the softened product.

50. A method of dissolving a composition according to any one of claims 1 to 28 or a product according to any one of claims 29 to 36, the method comprising the step of contacting the composition or product with liquid water.

51. The method of claim 50, wherein the liquid water is at a temperature of at least 50 ℃ for at least 1 hour.

52. The method of claim 51, wherein the liquid water has a temperature of at least 70 ℃.

53. A method of industrial biodegradation of a composition according to any one of claims 1 to 28 or a product according to any one of claims 29 to 36 said method comprising exposing said composition or product to conditions of increased rate of biodegradation.

54. The method of claim 53, wherein the condition is selected from the group consisting of: heating; contacting with water; contacting a microorganism; an enzyme; and mechanical failure.

55. A method of composting a composition as claimed in any one of claims 1 to 28 or a product as claimed in any one of claims 29 to 36 which method comprises exposing the composition or product to a material in which the composition or product degrades to form compost or an additive suitable for composting or addition as a fertiliser to soil.

56. The method of claim 55, wherein the condition is the addition of the composition or product to a previously composted or composted material.

57. A method of extending the shelf life of perishable goods, wherein the method comprises placing perishable goods into a structural inventory unit formed from the composition of any of claims 1 to 28.

58. The method of claim 57, wherein the perishable cargo is selected from the group consisting of: fruits; vegetables; a dairy product; a cheese; bread; a cake; biscuits; and a candy.

59. The method of claim 57 or claim 58, wherein the shelf life of the perishable cargo is extended by at least 25%.

60. Use of a composition according to any one of claims 1 to 28 or a product according to any one of claims 29 to 36 as a packaging material or as a disposable product such as a beverage container, tampon or tampon applicator.

Technical Field

The present invention relates to biodegradable compositions. In particular, the present invention relates to biodegradable compositions that are useful as substitutes for petroleum-based plastics and bioplastics in products such as single-use or disposable products. The invention also relates to: products formed from the compositions, including packaging materials, methods of dissolving, composting, and biodegrading the compositions or products, methods of producing the compositions and products, and methods of reprocessing the compositions.

Background

Conventional plastic products are made from petroleum-based plastics or plant-based bio-plastics. Such materials are lightweight, durable, have high barrier properties, have high tensile strength, and may have transparent or translucent visual characteristics. In addition, such materials may have heat sealability and moldability characteristics suitable for large-scale manufacturing. This makes them very suitable for use as packaging materials, for example.

It is generally desirable to dispense with petroleum-derived plastics. This is mainly due to the large environmental impact of such products in the production process and in the disposal streams after use. Furthermore, non-biodegradable bioplastics, which are not affected by industrial composting or other specific waste treatment processes, tend to decompose in nature, resulting in particulate plastic material (micro-or nano-plastics) remaining in the environment for hundreds of years, with adverse effects.

Without control, it is expected that plastics pollution will increase by four times by year 2050, at which time the weight of plastics in the ocean will be expected to exceed that of fish. One of the key factors contributing to this growing problem is the single use plastics (those that can be made into rigid and load-bearing containers) used as structural stock keeping units SKUs, such as for packaging and disposable cups or shallow fruit baskets.

In view of these problems, a trend has recently emerged to use biodegradable plastics. However, conventional biodegradable plastics tend to decompose slowly, often for a much longer period of time than the useful life of the product. Thus, even these so-called biodegradable plastics, known as environmental protection, require complex waste management systems or, if discarded improperly, can remain in the environment for a considerable time, potentially causing significant ecological hazards for decades or even hundreds of years.

Thus, there remains a need to replace plastics and bioplastics in products with environmentally friendly materials that biodegrade rapidly and completely in the environment or waste streams with no or minimal harm to the environment or ecosystem. Suitably, the biodegradation time is better matched to the time scale of use (especially single use) while still providing the desired material properties of at least one of the above-mentioned conventional plastics.

Disclosure of Invention

In a first aspect, the present invention provides a composition comprising an seaweed extract in an amount of 50-90 wt%, a water-soluble cellulose derivative in an amount of 10-40 wt% and water in an amount of 1-20 wt% of the total weight of the composition. Suitably, the seaweed extract is present in an amount of 60-85 wt%, the water-soluble cellulose derivative is present in an amount of 10-35 wt%, and the water is present in an amount of 2-15 wt%.

An alternative composition which does not form part of the present invention but which has a number of beneficial properties comprises seaweed extract in an amount of 2-5 wt%, a water-soluble cellulose derivative in an amount of 80-95 wt% and water in an amount of 4-15 wt%. Each of the following embodiments may also be applied to the composition.

In embodiments, the composition consists essentially of the seaweed extract, the water-soluble cellulose derivative, and water. In an alternative embodiment, the composition consists of the seaweed extract, the water-soluble cellulose derivative and water. In an embodiment, the weight percentages of the seaweed extract, the water-soluble cellulose derivative and the water total 100 weight% of the total weight of the composition.

In embodiments, the seaweed extract is selected from the group consisting of: carrageenan; agar; and mixtures thereof. Suitably, the seaweed extract is carrageenan. More suitably, the carrageenan is Kappa-type carrageenan.

In embodiments, the composition lacks one or more of the group consisting of: starch; iota-type carrageenan; agar; an alginate; and chitosan.

In embodiments, the water-soluble cellulose derivative is selected from the group consisting of: methyl Cellulose (MC); hydroxypropylmethylcellulose (HPMC); and mixtures thereof. Suitably, the water-soluble cellulose derivative is Methylcellulose (MC).

In embodiments, the composition further comprises one or more additives. Suitably, the one or more additives are present at no more than 10 wt% of the total weight of the composition. Suitably, the one or more additives are selected from the group consisting of: an inorganic salt; sawdust, paper, hemp fibers; calcium carbonate; glycerol; apple puree; starch; montmorillonite (MMT); cinnamon bark oil; soybean oil; glycerol; glucose; silver nanoparticles; grapefruit seed extract; rosa multiflora essential oil; non-clay or clay minerals; polyethylene glycol (PEG); chitin; arabinoxylan; banana powder; gelatin; titanium oxide nanoparticles; a colorant; and a flavoring agent.

In embodiments where the additive is an inorganic salt, the inorganic salt is a salt of an alkali metal or an alkaline earth metal. Suitably, the inorganic salt is selected from the group consisting of: a lithium salt; a sodium salt; a calcium salt; and potassium salts. More suitably, the inorganic salt is potassium chloride.

In embodiments, the composition of the first aspect of the invention passes at least 30% of incident light without absorption or scattering at a standard thickness of 0.5 mm. Suitably, at a standard thickness of 0.5mm, at least 50% of the incident light passes through without being absorbed or scattered.

In embodiments, the composition is fully biodegradable. Suitably, the composition is fully biodegradable in an external, non-industrial environment in less than six months. Suitably, the composition is fully biodegradable in an anaerobic atmosphere.

In embodiments, the composition is fully compostable. Suitably, the composition may be composted in a domestic compost heap of less than six months.

In an embodiment, the composition is edible.

In embodiments, the composition is moldable. Suitably, the composition may be moulded by compression moulding, injection moulding or cast moulding. In embodiments, the composition is reprocessed after molding.

In a second aspect, the present invention provides a product formed from the composition of the first aspect of the invention.

In embodiments, the product has a shape selected from the group consisting of: a plate; a planar sheet; regular or irregular spheres; regular or irregular spheroids; regular or irregular cubes; a regular or irregular cuboid; regular or irregular ellipsoids; a regular or irregular cylinder; a regular or irregular cone; regular or irregular prisms; regular or irregular pyramids; and any combination thereof.

In embodiments, the product is selected from the group consisting of: a structural Stock Keeping Unit (SKU); a packaging material; a film; a sheet material; a straw; a pipeline; tampons and applicators; a cutter; a plate; a tray; and a stirrer. Suitably, the product is a packaging material selected from the group consisting of: a container; and components thereof. More suitably, the container or part thereof is selected from the group consisting of: a cup; a tray; shallow basket; a solid clam shell; a box; a bottle; a tube; and a lid. In embodiments, the product is three-dimensional and rigid and load-bearing.

In embodiments, the maximum thickness of the composition in the product is in the range of 0.01mm to 5 mm. In embodiments, the product is translucent.

In a third aspect, the present invention provides a process for producing the composition of the first aspect of the invention, the process comprising the steps of:

(a) contacting the seaweed extract with water to form a seaweed extract hydrogel,

(b) separately contacting a water-soluble cellulose derivative with water to form a water-soluble cellulose derivative solution,

(c) mixing the seaweed extract hydrogel and the water-soluble cellulose derivative solution to form a mixture, and

(d) allowing the mixture to dry to form the composition.

In embodiments, step (a) comprises: (i) contacting the seaweed extract with water at a temperature in the range of about 5 ℃ to about 40 ℃, and then (ii) heating the mixture of seaweed extract in water to a temperature in the range of about 70 ℃ to about 100 ℃ to form a seaweed extract hydrogel.

In embodiments, in step (b), the water-soluble cellulose derivative is contacted with water at a temperature of about 70 ℃ to about 100 ℃.

In embodiments, step (c) comprises mixing the seaweed extract solution and the cellulose derivative solution at a temperature of about 70 ℃ to about 100 ℃.

In embodiments, the method comprises steps (a) to (d) of a method of producing a composition of the third aspect of the invention, and an additional step between steps (c) and (d): forming the mixture into the shape or three-dimensional form of a product. Suitably, the product is a product of the second aspect of the invention.

In embodiments, the forming step comprises molding. Suitably, the moulding comprises compression moulding, injection moulding or casting.

In embodiments, during step (d), the solid composition is supported on at least a portion of a mold used in molding.

In a fourth aspect, the invention provides a method of reprocessing a biodegradable composition comprising producing a product by the method of the third aspect of the invention, wherein the method further comprises:

f) softening or melting the product by contacting the product with water or steam to provide a softened product;

g) further processing the softened product to provide a reprocessed product, wherein the reprocessed product has a different shape than the product;

h) drying the reprocessed product to provide a dried reprocessed product.

In embodiments, the temperature of the water in step (f) is greater than 80 ℃, or is steam.

In embodiments, the operation in step (g) comprises reworking the softened product into the shape of a former or mold.

In embodiments, after drying in step (h), the dried shaped product is removed from the former or mould.

In embodiments, the operation in step (g) seals at least the edges or parts of the edges of the softened product.

In a fifth aspect, the present invention provides a method of dissolving a composition of the first aspect of the invention or a product of the second aspect of the invention, the method comprising the step of contacting the composition or product with liquid water. Suitably, the liquid water is at a temperature of at least 50 ℃ for at least 1 hour. Suitably, the liquid water is at a temperature of at least 70 ℃.

In a sixth aspect, the present invention provides a method of industrial biodegradation of a composition of the first aspect of the invention or a product of the second aspect of the invention, the method comprising exposing the composition or product to conditions of increased rate of biodegradation. Suitably, the conditions are selected from the group consisting of: heating; contacting with water; contacting a microorganism; an enzyme; and mechanical failure.

In a seventh aspect, the invention provides a method of composting a composition of the first aspect of the invention or a product of the second aspect of the invention, the method comprising exposing the composition or product to a material in which the composition or product degrades to form compost or an additive suitable for composting or addition to soil as a fertiliser. Suitably, the conditions are such that the composition or product is added to previously composted or composted material.

In an eighth aspect, the present invention provides a method of extending the shelf life of a perishable good, wherein the method comprises placing the perishable good in a container or structural inventory unit formed from the composition of the first aspect of the invention. Suitably, the perishable cargo is selected from the group consisting of: fruits; vegetables; a dairy product; a cheese; bread; a cake; biscuits; and a candy.

In embodiments, the perishable cargo has an extended shelf life of at least 25%.

In a ninth aspect, the invention provides the use of a composition of the first aspect of the invention or a product of the second aspect of the invention as a packaging material or as a disposable product, such as a beverage container, tampon or tampon applicator.

Drawings

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

fig. 1A shows a side view of a bar of the composition of the present invention (high algae content embodiment) before and after (a) and (B) contact with water (submersion) for 24 hours. The absorption of water by the composition is demonstrated by swelling from a thickness of 0.3mm to 7 mm.

Fig. 1B shows an embodiment of a cup formed from a composition of the present invention (high algae content embodiment) that retains water at room temperature. (A) Cup showing just after pouring water into the cup (T ═ 0); (B) shows the cup after 1.5 hours of pouring water into the cup (T ═ 1.5); (C) shows the cup after 8.0 hours of pouring water into the cup (T ═ 8.0); it can be seen that the composition absorbs water and begins to deform at room temperature, but still retains its structural integrity and remains watertight. The composition, after absorbing moisture, will acquire a texture and consistency like silicone.

Figure 2 shows an embodiment of a cup formed from a high algae composition of the present invention (as defined herein). (A) Is a cup that has been dried on the male part of the compression mold prior to demolding, and (B) is a cup prepared in the same manner as demolding from the mold prior to drying. (B) The cups shown in (a) shrink/deform significantly when dry. If unsupported during drying, the material is easily deformed due to the high water content (>90 wt% water) at the end of the manufacturing process.

Fig. 3 shows a former or mould (left) and packaging material (right) of a sheet comprising the high algae composition of the invention (as defined herein) which is then reprocessed according to the invention by folding on the former and drying it before release. In the illustrated embodiment, the sheet is hydrated to shape by immersing the sheet in hot water (90 ℃) for 5 seconds and then forming it around the former. The sheet on the former was then dried for 5 hours at ambient conditions. Immersing the sheet in hot water causes the surface of the sheet to soften and/or melt. Such softened and/or melted material on the surface of the sheet has a tackiness and can be used as an adhesive. For example, when the surfaces of the sheet are folded on top of each other, the molten material on the surfaces may cause the surfaces in contact with each other to stick together. This tackiness may aid in reworking the material.

Figure 4 shows the material degradation of cups formed from the high algae composition of the invention (as defined herein) after 0 months (a), 1 month (B) and 2 months (C) in home composting. The cup is surrounded by a plastic non-biodegradable mesh to retain the degradable material of the cup. Significant biodegradation was evident after 1 month, indicating continued near completion at 2 months.

Figure 5 shows the material degradation after 0 weeks (a), 1 week (B), 2 weeks (C) and 4 weeks (D) of immersion of cups made from the composition of the invention in seawater. The cup is surrounded by a plastic non-biodegradable mesh to retain the degradable material of the cup. After 2 weeks, significant biodegradation was evident, leaving only the mesh after 4 weeks.

Figure 6 shows material degradation (a) of cups formed from the composition of the invention after 0 weeks, 1 week (B) and 4 weeks (C) in the open air (simulating a roadside or urban environment). Significant biodegradation was evident after 1 week and continued for up to 4 weeks, at which time significant biodegradation was seen.

Figure 7 shows that after 4 weeks the cup of figure 6 shows no signs of degradation compared to prior art PLA-lined paper cups (white) and PET plastic cups (clear).

Fig. 8 shows biodegradation in air after 10 seconds (a) hours (B), 3 days (D), 9 days (E), 14 days (F) and 21 days (G) at room temperature for cups containing water formed from the compositions of the present invention. During this time, the deformation of the cup is evident, but the structural rigidity is preserved, the cup remaining upright and watertight. From day 9 on, bacterial growth was evident, as the biodegradation process lasted 14 and 21 days.

Fig. 9 shows the results of the bio-digestion test. From left to right, the shredded strips of the composition of the invention are shown with bile salts (a), protease hcl (b), amylase (C), saliva (D) and deionized water (E). The shredded strips either completely decomposed or dissolved in the given solution within 3 hours at room temperature.

Fig. 10 shows comparative examples of storage of soft fruits (strawberries) after 1-2 days (column a), 3 days (column B) and 4 days (column C) in a packaging formed from a composition of the present invention (bottom line) compared to a packaging formed from petroleum derived PET (top line) under non-refrigerated ambient conditions. It is clear that after 3 days condensation occurred on the inner wall of the PET package, increasing by 4 days. There is no significant condensation on the packages formed by the present invention. Since condensation implies a high humidity that promotes the growth of bacteria and fungi, this indicates that the packaging of the present invention will result in a lower rate of bacterial or fungal growth on the food product contained therein.

Figure 11 shows that the packaging material formed by the present invention (right column) stores soft fruit (raspberry) under non-refrigerated ambient conditions for 1 day (row a), 2 days (row B) compared to the packaging material formed by petroleum derived PET (left column); 3 days (row C); 4 days (row D); 5 days (row E); and comparative example after 6 days (row F). It is clear that the raspberry in the PET cup started to mold on day three, whereas the raspberry in the cup formed from the composition of the invention did not mold until day 6, increasing shelf life by 100%.

Figure 12 shows a piece of cheddar cheese which has been heat sealed in a bag made from a composition of the invention. The upper panel shows cheese immediately after sealing, and the lower panel shows the same cheese stored for 1.5 years. After this time, there was no obvious sign of spoilage in the cheese.

Figure 13 shows material degradation of cups formed from compositions of the invention under anaerobic conditions.

Figure 14 shows the change in pigmentation of the compositions of the invention with different or different proportions of seaweed extract as defined in example 6.

Fig. 15 shows a cup formed from the following materials: (A) a composition according to the invention comprising Kappa carrageenan and methylcellulose; (B) a composition comprising iota-type carrageenan and methylcellulose according to the invention; (C) the composition according to the invention comprises agar and methylcellulose. The ratio of seaweed extract, methylcellulose and water given in each cup was constant. It is clearly seen that all of the compositions can be molded to form rigid and load-bearing structures. The cups formed from Kappa carrageenan (A) had no molding defects, whereas the cups formed from agar (B) exhibited cracks when dried, while iota carrageenan (C) exhibited instability when solidified, resulting in wrinkling of the top edge. It is also evident that the cups formed with agar (B) have a high pigmentation.

Detailed Description

The present invention generally relates to biodegradable compositions. In embodiments, the composition is suitable for use as a moldable material for forming shaped products, such as three-dimensional structural products. For example, such products may be packaging materials; tableware, such as plates, trays, baskets, clamshells, or cups; other feeding or drinking devices, such as straws, cutlery or blenders; or other film, sheet or shaped structural products. In embodiments, the compositions may be used as a replacement or substitute for petroleum-derived plastics, bioplastics, and prior art biodegradable plastics.

For convenience, certain terms employed in the specification and examples are described herein before the present disclosure is further described. These definitions should be understood in light of the remainder of this disclosure and by those skilled in the art. Terms used herein have meanings that are recognized and known by those skilled in the art, however, for convenience and completeness, specific terms and their meanings are described below.

The words "a," "an," and "the" are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the word.

As used herein, the term "comprising" means that any of the listed elements must be included, and that other elements may also optionally be included. "consisting essentially of … …" means that any of the recited elements must be included, that elements that would materially affect the basic and novel characteristics of the recited elements are excluded, and that other elements may optionally be included. "consisting of … …" means that all elements except those listed are excluded. Embodiments defined by each of these terms are within the scope of the invention. The term "comprising" when used in reference to certain ingredients of a composition should be understood to provide a definite literal basis for the term "consisting essentially of, and" consisting of "those same components.

As used herein, the term "biodegradable" refers to a material that is capable of being chemically and/or physically broken down in nature and/or by the action of a living organism. The term is used herein to refer to compositions or components of compositions that naturally break down into harmless ingredients in water or aqueous or humid environments, typically by the action of microorganisms such as bacteria or fungi. The composition may meet european standard EN 13432 or, more generally, 90% of the material breaks down into particle fragments of size not exceeding 2mm after 12 weeks and biodegrades at least 90% after 6 months (laboratory test method EN 14046). As defined herein, the term "super-biodegradable" may be used to refer to a material having a particularly fast biodegradation rate, e.g. less than 6 months, suitably less than 3 months, to fully biodegrade in a natural, non-adapted environment or waste stream. In this context, the term "natural" or "natural" refers to non-industrial environments and/or environments that are not suitable for promoting biodegradation, such as open air or home composting.

As used herein, the term "compostable" refers to a material that is capable of being broken down in nature and/or by the action of organisms to serve as compost. Suitably, the term "compostable" may be used to refer to a composition or product that may be acceptably added to a composting site. The term "home compostable" may be used to refer to a composition or product that may be compostable in a home environment, for example, added to a compost pile found in a home garden. The term may refer to a plastic that conforms to australian standard AS 5810 "biodegradable plastic-biodegradable plastic suitable for home composting"; belgium authenticatedOK compost home certification protocol, requiring at least 90% degradation within 12 months at ambient temperature; and/or the French Standard NF T51-800 "plastics-plastics Specifications for domestic composting". The term "industrial compostable" may be used to refer to compositions or products that may be acceptably added to an industrial composting waste stream. For example, an industrial complex waste stream may involve an active complex phase followed by curing. The active composting phase typically lasts at least 21 days and the temperature in the compost heap is maintained at about 50 ℃ to 60 ℃ throughout the period. For hygienic purposes, the temperature may be kept above 60 ℃ for at least one week,to eliminate pathogenic microorganisms. In the solidification stage, the decomposition rate is slowed down and, with the synthesis of humic substances, the temperature is reduced to<40℃。

As used herein, the term "harmless" means non-toxic or non-risk to humans and animals or the environment. By a compound, harmless may mean compliance with any one or more of EC regulation No. 1907/2006, EC regulation No. 1272/2008, REACH directive 1999/45/EC, No. 76/769/EEC, european council directive 793/93 and 91/155/EEC, 93/67/EEC or 67/548/EEC; or to toxicity class IV (practically non-toxic and non-irritating) as specified in title 40 of the federal regulations in the united states, 156.62, or an equivalent thereof.

As used herein, the term "edible" refers to a harmless substance that can be ingested by a human or animal without adverse effects or risks to health.

The term "bioplastic" as used herein refers to a plastic material produced from renewable biomass sources, such as vegetable fats and oils, corn starch, straw, wood chips, sawdust, recycled food waste, and the like. Bioplastics can be made from agricultural byproducts. Bioplastic means that the source of material from which the plastic is made is bioplastic. Bioplastics do not infer that the material is biodegradable, although some bioplastics may also be biodegradable.

As used herein, the term "seaweed" refers to a common term for groups of multicellular algae commonly found in or near the ocean or fresh water body. The species of seaweed includeRed algae(red color),Brown algae(Brown)

Andgreen algae(green) macroalgae. Many brown algae are simply referred to as kelp.

As used herein, the term "seaweed extract" refers to an isolated or isolated component or constituent of seaweed. Suitably, the isolation or isolation method is by chemical or physical extraction (i.e. gel pressing or alcohol precipitation and alkaline hydrolysis). For example, the seaweed extract may be obtained by pulverizing a seaweed plant or a part thereof, followed by filtration to remove solid seaweed residue material; alternatively, or in the alternative, the seaweed is washed with a suitable solvent, such as an aqueous alkaline solution, and the desired extract is collected as a residual insoluble material or a partially insoluble material. The extract may be subjected to further purification/separation steps. Examples of seaweed extracts according to the meaning herein are extracts of carrageenan, agar and alginate, suitably carrageenan.

As used herein, the term "carrageenan" refers to a family of linear sulfated polysaccharides extracted from red seaweed. Carrageenans are mainly classified into three types, which differ in their degree of sulfation. kappa carrageenan has one sulfate group per disaccharide, iota carrageenan has two sulfate groups and lambda carrageenan has three sulfate groups.

As used herein, the term "polysaccharide" refers to long chain carbohydrate molecules, particularly polymeric carbohydrates composed of monosaccharide units joined together by glycosidic bonds. Examples include "storage polysaccharides" such as starch and glycogen, and "structural polysaccharides" such as cellulose and chitin. Starch is a glucose polymer in which glucopyranose units are linked by alpha bonds; cellulose is a polymer made of repeating glucose units joined together by beta bonds. Cellulose can be chemically modified, for example, by alkylating free hydroxyl groups in cellulose with various alkyl groups such as methyl groups to produce methylcellulose; or hydroxypropyl to make hydroxypropyl cellulose (CAS number: 9004-64-2) or hydroxypropyl methylcellulose (HPMC) (CAS number: 9004-65-3).

As used herein, the term "water-soluble cellulose derivative" refers to a cellulose-derived material or compound that is readily soluble in water at room or ambient temperature. Suitably, the term refers to a material or compound derived from cellulose. For example, methylcellulose readily dissolves in water at temperatures below 40 ℃ to 50 ℃; hydroxypropyl cellulose is readily soluble in water at temperatures below 45 ℃. Both methylcellulose and hydroxypropylcellulose exhibit atypical behavior that becomes more difficult to dissolve at higher temperatures.

Petroleum-based plastics are widely used in industry because of their structural rigidity, translucency, ability to contain liquids and to shape products. This has led to a proliferation of use of petroleum derived plastics in many industries, for example, food packaging and other food or beverage related items such as cups, plates and cutlery. Such products may be formed by molding (e.g., injection molding, blow molding, compression molding, extrusion, etc.) or casting, or by forming into sheets that are then reprocessed to form shaped and/or three-dimensional products.

As is now well documented, while petroleum-based plastics and some bioplastics have many desirable material properties, their use problems are related to their lifetime in the environment or waste streams, suggesting between 10 and 1,000 years. The time scale of this decomposition is not at all proportional to the typical service life of plastics, which may be, for example, several hours or days in the case of food packaging. The fact that the plastics used to produce disposable products may continue to exist for up to 1000 years after the product has been discarded is clearly a great problem from an environmental or ecological point of view.

Even plastics that are known to be biodegradable, such as polylactic acid (PLA) or Polyhydroxyalkanoates (PHA), may still take months or even years to biodegrade completely. This means that the plastic will remain intact in the environment during this time, with about the same negative impact on ecosystem and wildlife as petroleum-based plastics.

The increasing use of plastics, whether petroleum-based, plant-derived or those known as biodegradable plastics, and the slow or relatively slow rate of decomposition of these materials relative to their use as products has led to an increasing increase in the amount of plastic waste in our landfills and in a wider variety of environments, including particulate matter in the ocean. This has and continues to cause unprecedented damage to terrestrial, airborne, and marine environments and ecosystems. The permanence of plastics and bioplastics in the environment also means that if they are not disposed of by a suitable waste stream, they can remain on the street as unsightly waste and can cause blockages in waterways and sewers, resulting in expensive measures and cleaning operations to retrieve these materials. Furthermore, it is well known that slow but eventual decomposition of plastics and bioplastics in the environment can lead to the release of so-called "micro-plastics" or "nano-plastics" (plastic particles with sizes in the micro-or nano-range) causing further damage to the ecosystem. Recent records have shown that "nanoplastics" are polluting the air and are therefore inhaled by humans and other organisms. The overall effect of this mode of plastic contamination is unclear, although it is well known that many plastics exude harmful chemicals with aging and decomposition, which can irritate the lungs and other body organs, causing discomfort and disease. When animals ingest plastics or bioplastics that they cannot digest, this can lead to blockage of their digestive system, which in some cases can lead to starvation, resulting in the death of the animal.

Further ecological problems of plastics and bioplastics can also be determined by the fact that: they decompose slowly in composting facilities and are generally not biodegradable, or at least not completely biodegradable. This can result in plastic contaminants being applied to the soil as part of the compost, thereby reducing soil quality. The global population is expected to grow from 76 billion today to about 100 billion in the next 30 years. This would mean that agriculture and land utilization face greater pressure for growing food for humans and livestock. Any decline in soil fertility today or this century is counter to the ever-expanding global population's demand for reliance on this fundamental resource.

The present invention relates to biodegradable compositions that completely and rapidly decompose (are highly biodegradable) in the environment, particularly in various aqueous or other non-dry environments, or in waste streams, but that retain one, more, or all of the benefits of petroleum-based plastics or plant-based bioplastics over their useful life.

The compositions of the present invention generally comprise an extract of seaweed and a water-soluble cellulose derivative. The composition may also comprise water. Suitably, the composition comprises seaweed extract, a water-soluble cellulose derivative and water. Suitably, the composition consists essentially of seaweed extract, water-soluble cellulose derivative and water. Suitably, the composition consists of seaweed extract, water-soluble cellulose derivative and water.

In embodiments, the seaweed extract may be carrageenan, agar or a mixture thereof. The carrageenan compounds and agar family are well known in the food, pharmaceutical and personal care product arts; however, they are chemically different. Carrageenan contains the repeating unit beta-D-galactose-cc-D-galactose, while agar contains repeating beta-D-galactose-alpha-L-galactose. Suitably, the seaweed extract used in the composition of the present invention is carrageenan. More suitably, the carrageenan may be a kappa-type carrageenan.

It is contemplated that any seaweed extract may be used in the present invention. However, as expected, while carrageenans, agar and other seaweed extracts have a common source (seaweed) and related chemical structure, each has significantly different properties in forming a highly biodegradable plastic substitute material therefrom. For example, carrageenans, in particular kappa-type carrageenans, when mixed with water-soluble cellulose derivatives, such as methylcellulose, show surprisingly beneficial mechanical and visual material properties compared to agar and other seaweed extracts, as in the present invention.

In embodiments, the water-soluble cellulose derivative may be any suitable material or compound derived from cellulose. Suitably, the water-soluble cellulose derivative may be Methylcellulose (MC), Hydroxypropylmethylcellulose (HPMC) or a mixture thereof. Suitably, the water-soluble cellulose derivative may be Methylcellulose (MC).

In an embodiment, the composition comprises only seaweed extract, such as carrageenan, and a water-soluble cellulose derivative, such as methylcellulose, the remainder of the composition being water. In other words, the composition may consist of the seaweed extract and the water-soluble cellulose derivative, or of the seaweed extract and the water-soluble cellulose derivative and water, as defined herein. In other words, the weight percentages of these components may add up to 100 weight percent, based on the total weight of the composition.

In embodiments, it is contemplated that other minor additives may be included that may provide one or more benefits without adversely affecting the bulk properties of the composition. In other words, as defined herein, the composition may consist essentially of the seaweed extract and the water-soluble cellulose derivative, or the seaweed extract and the water-soluble cellulose derivative and water. The term "minor additive" or "additive" is intended to relate to additives other than seaweed extract and water-soluble cellulose derivative, which may be present in the composition in an amount of 20 wt% or less. Suitably less than 15 wt%, 10 wt%, 5 wt%, 2 wt%, 1 wt%. All weight percents are based on the total weight of the composition. In other words, the weight percentages of seaweed extract, water-soluble cellulose derivative, water and one or more minor additives add up to 100% by weight, based on the total weight of the composition.

The additive or minor additive may be, but is not limited to: inorganic salts such as potassium chloride or calcium chloride; sawdust, paper, hemp fibers; calcium carbonate; glycerol; apple puree; starch; montmorillonite (MMT); cinnamon bark oil; soybean oil; glycerol; silver nanoparticles; grapefruit seed extract; rosa multiflora essential oil; non-clay or clay minerals; polyethylene glycol (PEG); chitin; arabinoxylan; banana powder; gelatin; titanium oxide nanoparticles. Alternatively, in embodiments, the compositions of the present invention and products formed therefrom may lack any minor additives, including but not limited to one or more of those listed above.

In embodiments, the composition may comprise a salt, more suitably an alkali or alkaline earth metal, even more suitably a lithium, sodium, calcium or potassium salt. Most suitably, the composition may comprise a potassium salt. In an embodiment, the potassium salt is potassium chloride. Suitably, the composition may comprise in the range of from 0.1 to 5 wt% salt, more suitably in the range of from 0.5 to 3 wt% salt, even more suitably in the range of from 0.5 to 1.5 wt% salt. Suitably, the salt may be present in an amount of at least 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, 2.0 wt%, 3.0 wt%, 4.0 wt% or more. Suitably, the salt may be present in an amount of up to 5.0 wt%, 4.0 wt%, 3.0 wt%, 2.0 wt%, 1.9 wt%, 1.8 wt%, 1.7 wt%, 1.6 wt%, 1.5 wt% or less; all weight percents are based on the total weight of the composition. Without wishing to be bound by theory, it is believed that inclusion of such salts may increase the rigidity of the resulting composition and products formed therefrom.

In embodiments, the composition may comprise glycerin. More suitably, the composition may comprise glycerol in an amount in the range of from 0.1 to 5 wt.%, even more suitably in an amount in the range of from 1 to 3 wt.%, more particularly in an amount in the range of from 1.5 to 2.5 wt.%, all weight percentages being based on the total weight of the composition. Without wishing to be bound by theory, it is believed that the inclusion of glycerol may increase the flexibility of the resulting product.

In embodiments herein referred to for reference purposes only as "low seaweed extract compositions", the composition may comprise 1-10 wt%, suitably 2-5 wt% seaweed extract. Suitably, the composition may comprise the seaweed extract in an amount of at least 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8% or 9% by weight. Suitably, the composition may comprise the seaweed extract in an amount of up to 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3% or 2% by weight. All weight percents are based on the total weight of the composition.

In embodiments, the low seaweed extract composition may comprise the water-soluble cellulose derivative in an amount of 70-95 wt.%, more particularly 80-95 wt.%. Suitably, the composition may comprise the water-soluble cellulose derivative in an amount of at least 70 wt%, 75 wt%, 80 wt%, 85 wt% or 90 wt%. Suitably, the composition may comprise the water-soluble cellulose derivative in an amount of up to 95 wt%, 90 wt%, 85 wt%, 80 wt% or 75 wt%. All weight percents are based on the total weight of the composition.

In embodiments, the low seaweed extract composition may comprise from 2 to 20 weight percent water, even more specifically from 4 to 15 weight percent, all weight percentages being based on the total weight of the composition. Suitably, the composition may comprise water in an amount of at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 wt%. Suitably, the composition may comprise water in an amount of up to 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4 or 3 wt%. All weight percents are based on the total weight of the composition.

In a specific embodiment of the low seaweed extract composition according to the present invention, the composition may comprise carrageenan type kappa in an amount of 2-5% by weight, methylcellulose in an amount of 80-95% by weight, water in an amount of 4-15% by weight. In one embodiment, the composition may further comprise 1-5% by weight potassium chloride. All weight percents are based on the total weight of the composition. In embodiments, the weight percentages of kappa-carrageenan, methylcellulose, water, and optionally potassium chloride, may add up to 100 weight percent, based on the total weight of the composition.

In an alternative embodiment, which is referred to herein for reference purposes only as a "high seaweed extract composition", the composition may comprise the seaweed extract in an amount of 40-95 wt%, suitably 50-95 wt%, more suitably 60-90 wt%. Suitably, the composition may comprise the seaweed extract in an amount of at least 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85% or 90% by weight. Suitably, the composition may comprise the seaweed extract in an amount of up to 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50% or 45% by weight. All weight percents are based on the total weight of the composition.

In embodiments, the high algae extract composition may comprise the water-soluble cellulose derivative in an amount of 5-50 wt%, more suitably 10-40 wt%. Suitably, the composition may comprise the water-soluble cellulose derivative in an amount of at least 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt% or 45 wt%. Suitably, the composition may comprise the water-soluble cellulose derivative in an amount of up to 50 wt%, 45 wt%, 40 wt%, 35 wt%, 30 wt%, 25 wt%, 20 wt%, 15 wt% or 10 wt%. All weight percents are based on the total weight of the composition.

In embodiments, the high algae extract composition may comprise 1-20 wt% water, even more specifically 2-15 wt%, all weight percentages based on the total weight of the composition. Suitably, the composition may comprise water in an amount of at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 wt%. Suitably, the composition may comprise water in an amount of up to 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4 or 3 wt%. All weight percents are based on the total weight of the composition.

In a particular embodiment of the high seaweed extract composition according to the present invention, the composition may comprise kappa-carrageenan in an amount of 50-90 wt% or suitably 66-85 wt%, methylcellulose in an amount of 25-35 wt% or suitably 11-33 wt%, 4-25 wt% or suitably 2-11 wt% of water. In embodiments, the composition may further comprise 1-5% by weight potassium chloride. All weight percents are based on the total weight of the composition. In embodiments, the weight percentages of kappa-carrageenan, methylcellulose, water, and optionally potassium chloride, may add up to 100 weight percent, based on the total weight of the composition.

The composition of the present invention is hygroscopic, i.e. it absorbs water. The high seaweed extract composition is more hygroscopic than the low seaweed extract composition, but both absorb water to at least some extent. Without wishing to be bound by theory, it is believed that the particular biodegradability or biodegradability of the compositions of the present invention is due, at least in part, to their ability to absorb water and that the main components of the compositions are natural food sources, promoting and promoting the growth of microorganisms, such as bacteria or fungi, on the compositions, thereby causing their biodegradation.

When used as a container for water or water-based liquids, the high algae extract compositions of the present invention can absorb large amounts of water without losing integrity or leaking or splitting. The seaweed extract composition of the present invention may absorb water at a temperature of about 60 ℃ or less; above this temperature, the high algae composition begins to dissolve. For example, the material may absorb approximately 10-13 grams of water per gram of material, resulting in a weight change of the material when exposed to water of approximately 1,000% to 1,300%. The composition after water absorption had a silicone-like feel. Fig. 1A shows the visual swelling of a strip of material formed from the high algae extract composition before and after 1 day immersion in water, and fig. 1B shows the visual swelling of a cup formed from the high algae extract composition over a period of 8 hours of exposure to water. It can be seen that the cup maintains sufficient structural integrity to maintain its overall shape and water in the cup while absorbing water from contact.

The tendency of the composition to absorb water on contact promotes microbial growth, thereby promoting rapid (< 2 months for the high algae extract composition) and significant biodegradation [ e.g., humidity or precipitation ] (urban roadside-type environment), composting, waste streams or sewers, oceans or rivers upon contact with water in the air. Furthermore, without wishing to be bound by theory, it is speculated that the ability of the material to absorb moisture in this manner, and then release it again by evaporation, is one factor in its rapid physical degradation due to the collapse and breakdown of the material structure caused by the stresses generated in the material by the wetting and drying cycles.

The compositions of the present invention also disintegrate and/or dissolve in the digestive fluids. As shown in fig. 9, the composition of the present invention disintegrates and/or dissolves in typical mammalian digestive fluids, such as bile salts, acid protease solutions, amylase, saliva, at room temperature. Thus, in view of the non-toxic and food-safe components, the composition is expected to be harmless for human and/or animal consumption, i.e. the material is in principle at least edible. Since seaweed extracts, in particular carrageenan and agar, are common additives in many food products, for example, a feature of the composition of the present invention is that the composition is food safe. It is contemplated that the product formed from the composition may be consumed by the end user. In view of the surprisingly beneficial properties of the composition to decompose in the digestive juices, this provides a means of treating the material without the need for a special waste stream.

In the low seaweed extract embodiment, the composition may be dissolved in liquid water at a temperature of 40 ℃ or less, more particularly 30 ℃ or less, even more particularly 25 ℃ or less. The length of time required for dissolution depends on the form, shape and thickness of the material. For example, a sheet material having a thickness of about 1mm, with continuous mixing at room temperature, would be expected to dissolve completely within 3 hours.

In embodiments of the high algae extract, the composition is soluble in water at a temperature of at least 50 ℃, more particularly at least 75 ℃, even more particularly at least 85 ℃. The length of time required for dissolution depends on the form or shape and thickness of the material sheet wall thickness of about 1mm, and continuous mixing at 85 ℃ is expected to dissolve completely within 1 hour.

Although the compositions of the present invention or products formed therefrom exhibit surprisingly beneficial properties with respect to biodegradability in the environment or in water, the compositions or products formed therefrom may exhibit a shelf life of up to 3 years, more particularly 2-3 years, prior to use when stored at a relative humidity of 70% or less.

In another aspect, the present invention relates to a product comprising or formed from the above biodegradable composition. In embodiments, the product may be a shaped article, such as a sheet or film, or the product may be a three-dimensional shaped article. Suitably, the three-dimensional shaped article may be generally shaped as a plate or a planar sheet, or a regular or irregular sphere or spheroid, cube or cuboid, ellipsoid, cylinder, cone, prism, pyramid or a combination of these. Suitably, the product may be a packaging material. Suitably, the packaging material may be a container or a portion thereof. Suitably, the container or portion thereof may be a cup, tray, basket, clamshell, box, bottle, tube or cap. Suitably, the container or part thereof may be a packaging material, in particular a packaging material for perishable goods such as food. In addition to packaging, the present invention also relates to other disposable consumer products such as straws, cups, tampons and tampon applicator tubes, such as tampon sticks, plates or food trays formed from the above-described compositions. The surprising structural rigidity and other material properties of the composition make it particularly suitable for structural three-dimensional products with thin walls, such as packaging materials and cups.

In embodiments, the thickness of the product may be suitable for use, for example the thickness of the tampon may be 1cm or more. Suitably, when the product is a biodegradable packaging material or a cup, for example, the product of the invention may have a thickness (minimum distance between two surfaces of the product) of 5mm or less. Suitably, the product may have a thickness of at most 4.5mm, 4.0mm, 3.5mm, 3.0mm, 2.5mm, 2.0mm, 1.5mm, 1.0mm, 0.5mm, 0.4mm, 0.3mm, 0.2mm or 0.1mm or less. Suitably, the product may have a thickness of at least 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1.0mm or more. Each of these thicknesses can be used for structural and load bearing three-dimensional products.

In embodiments, and at the thicknesses described above, the packaging material may be suitable for heat sealing using industry standard techniques, for example using moisture or steam and/or pressure. High algae extract compositions may require both steam and pressure, as steam can melt the surface of the materials and can create an adhesive surface that allows the materials to adhere to each other. On the other hand, low seaweed extract requires only cold water and pressure, since the material will soften in cold water to form an adhesive surface on the material, which will adhere the surfaces to each other and form a continuous shape.

Compared to some prior art biodegradable plastics or bioplastics, which are limited in structural rigidity and are commonly used as films or sheets, such as coatings for pharmaceutical tablets, the compositions of the present invention, when molded and subsequently dried, form a rigid, self-supporting structure capable of supporting loads and/or maintaining beverage characteristics, similar to petroleum-based plastics, such as PET or polystyrene. The rigid and high tensile strength properties of the compositions of the present invention allow the use of the materials to form "structural packaging," i.e., packaging or products that form three-dimensional load-bearing structures, without the need for external support of the structure, and films or sheets that are wrapped and supported by other structures or products. Without wishing to be bound by theory, it is believed that the seaweed extract, suitably carrageenan, in particular kappa-type carrageenan, provides surprisingly beneficial properties to the composition in terms of structure and load-bearing capacity.

The compositions of the present invention or products formed therefrom may receive print media, such as water-based or oil-based inks. The compositions of the present invention and products formed therefrom may be suitably molded to exhibit the details of the embossing present on the mold. The structural rigidity of the product is similar to that of petroleum-based plastics, which means that the product form of the composition of the present invention will be able to be used in current printing machinery without modification.

Furthermore, in embodiments, a particular advantage of products formed from or comprising the compositions of the present invention is that they may be transparent (allowing light to pass through with no or minimal scattering or absorption) or at least translucent (allowing light to pass through with some scattering or absorption). Suitably, greater than 30% of incident light can be transmitted through the composition at a standard thickness (minimum distance between two surfaces) of 0.5mm without scattering or loss. Suitably, greater than 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95% or 100% of incident light can pass through the material without scattering or loss at a standard thickness (the minimum distance between two surfaces) of 0.5 mm. Light transmittance can be measured according to ASTM D1746.

Transparent or translucent provides an attractive appearance that is similar in nature to transparent PET plastic or PLA bioplastic. Without wishing to be bound by theory, it is believed that the addition of a water-soluble cellulose derivative, such as methyl cellulose, acts to reduce the viscosity of the seaweed extract solution, suitably the kappa carrageenan solution, allowing more efficient defoaming (removal of trapped air bubbles) during the manufacturing process. This improves the light transmittance of the product shaped by final drying. It is also believed that the addition of a water-soluble cellulose derivative, such as methyl cellulose, also dilutes the seaweed extract solution, suitably the natural coloration of the kappa-type carrageenan solution, meaning that the dried moulded product is essentially colorless or has only a slight coloration resulting in no or little absorption or scattering of light by the material.

Seaweed extracts such as kappa carrageenan have a yellow/brown pigmentation. Increasing the content of seaweed extract will enhance the yellow/brown coloration of the final material.

The translucency of the compositions of the present invention or products formed therefrom depends, at least in part, on the thickness of the material formed (the minimum distance between two surfaces). In embodiments, a product of the invention that is intended to be transparent or translucent may have a thickness (the minimum distance between two surfaces of the product) of 5mm or less. Suitably, the product may have a thickness of at most 4.5mm, 4.0mm, 3.5mm, 3.0mm, 2.5mm, 2.0mm, 1.5mm, 1.0mm or 0.5mm or less. Suitably, the product may have a thickness of at least 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1.0mm or more.

In embodiments in which the composition or product formed therefrom has a thickness of greater than 5mm, or suitably 6mm, 7mm, 8mm, 9mm or 10mm, the product may be substantially opaque (i.e. substantially no light may pass through). Thus, the look and feel of the resulting product may look like opaque polyethylene terephthalate (PET) or polylactic acid (PLA). In embodiments, to increase the opacity of the composition, a compounding process may be used, by adding aggregates such as sawdust or paper fibers.

The products of the present invention, such as packaging materials, can exhibit useful oxygen barrier properties. This may mean that the packaging material will keep the contained item fresh for a longer time and extend its shelf life.

In another surprising benefit of the present invention, it has been found that food packaging made from or comprising the composition of the present invention can extend the shelf life of food products, suitably fresh food products, vegetables or dairy products such as cheese contained therein, compared to conventional petroleum-based plastics (e.g. polyethylene terephthalate (PET)) or bioplastics (e.g. PLA). The hygroscopic nature of the composition means that any ambient moisture within the package is absorbed and retained by the composition, which means that the environment in which the food is stored becomes less suitable for microbial growth, which is often responsible for mold growth and spoilage. This, together with the oxygen barrier properties of the composition, delays the decomposition of the food in the package, thereby extending the shelf life of the food.

In embodiments, the shelf life (defined as the length of time an item remains suitable for consumption or marketable) of a product or perishable good contained in a product or structural Stock Keeping Unit (SKU) may be at least 10% longer at a given temperature. Suitably, the shelf life may be extended by at least 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 200%, 300%, 400%, 500% or more.

As best shown in fig. 10 to 12, soft fruits, in particular strawberries and raspberries, and dairy products, such as cheddar cheese, retained in packages made from the compositions of the present invention show reduced condensation on the package walls compared to previous overwraps made from PET. It also shows a slow rate of disintegration of fruit stored in the package.

Since the compositions are formed from natural materials that are already commonly present in food products as thickeners or gelling agents, the products of the present invention are edible, i.e. they are non-toxic to humans and/or animals upon contact or ingestion. The composition may contain flavoring agents or other minor ingredients to enhance the palatability of the material. This is consistent with the evidence that the compositions of the present invention dissolve or disintegrate in digestive fluids, representing a further environmentally friendly way of disposing of the compositions.

In another aspect, the present invention relates to a process for preparing a composition as defined above, comprising the steps of:

(a) contacting the seaweed extract with water or other suitable polar solvent to form a seaweed extract hydrogel;

(b) contacting the water-soluble cellulose derivative with water or other suitable polar solvent, respectively, to form a solution, gel or slurry of the cellulose derivative;

(c) mixing the seaweed extract hydrogel and the cellulose derivative solution to form a mixture;

(d) the mixture is allowed to dry to form the composition.

The seaweed extract in step (a) and/or the cellulose derivative in step (b) may be as defined elsewhere herein.

The suitable polar solvent in step (a) or (b), other than water, may be any polar solvent capable of forming a suitable hydrogel with the seaweed extract or a suitable solution, slurry or hydrogel with the water-soluble cellulose derivative. Suitably, the polar solvent has a boiling point which allows drying of the formulation after moulding. Suitably, the solvent is harmless and does not destroy the environment. In this context, polar solvents may include, but are not limited to, ethanol, methanol, propanol, butanol, acetone, ethyl acetate, and dimethylsulfoxide.

In embodiments, in step (a), the seaweed extract, suitably in powder form, is mixed or otherwise combined with cold water to form a paste. The paste is then suitably mixed and heated to an elevated temperature. Upon heating, a hydrogel of seaweed extract is formed. Suitably, the elevated temperature may be 80 ℃ or higher, more suitably 80 to 100 ℃, even more suitably 90 to 100 ℃. In embodiments, the paste may be maintained at the elevated temperature for between about 20 minutes and about 4 hours. Suitably, the contacting is for between about 1 hour and about 3 hours. Most suitably, the contact time is about 2 hours.

In embodiments, in step (a), the concentration of seaweed extract in the seaweed extract hydrogel may be 4-8% w/v, even more suitably 6-7% w/v, more suitably 6.7% w/v of the seaweed extract hydrogel. In embodiments, after step (a), additional water or other suitable polar solvent is added to the hydrogel to achieve the desired viscosity. Suitably, the seaweed extract hydrogel used in step (c) is a liquid gel in consistency. The amount of water may be between 100% and 300% of the original volume of water added in step (a).

In embodiments, the concentration of the water-soluble cellulose derivative in the water-soluble cellulose derivative solution in step (b) may be from 2 to 30 wt%, more suitably from 5 to 20 wt%, even more suitably from 13 to 18 wt%, or most suitably 13.6 wt%. Suitably, the consistency of the solution of water-soluble cellulose derivative added in step (c) is a flowing liquid gel.

In embodiments, step (b) may be carried out at elevated temperature. Suitably, the contacting may be at a temperature of greater than 80 ℃, more suitably in the range of from 80 ℃ to 100 ℃, even more suitably from 90 to 100 ℃.

More specifically, in embodiments allowing the seaweed extract hydrogel to cool at the end of step (a), step (c) may comprise the step of heating the seaweed extract solution to a temperature of more than 50 ℃, more particularly 70-100 ℃, even more particularly 80-90 ℃ prior to mixing. The heating step may be carried out with stirring, suitably without stirring or other agitation during the heating.

In embodiments, step (c) may comprise adding and/or heating the seaweed extract solution and the water-soluble cellulose derivative solution at a temperature of greater than 50 ℃, more suitably from 70 ℃ to 100 ℃, even more suitably from 80 ℃ to 90 ℃. Suitably, the heating in step (c) is accompanied by mixing. Suitably, the mixing is only carried out at the start of heating. This mixing may be carried out by stirring. Suitably, the mixing may last from about 15 minutes to about 30 minutes. Suitably, the heating time of the mixture may be longer than the mixing time. In embodiments, the heating may last from about 3 hours to about 8 hours. Most suitably, the heating may last for about 5 hours. After the stirring is complete, the mixture can be heated without mixing for 4 to 6 hours.

Shortly after mixing the seaweed extract hydrogel with the water-soluble cellulose derivative solution, foaming may occur due to the formation of air bubbles in the mixture. Foaming may continue throughout the heating of step (c). The foam may be removed at any time during or after step (c) and the removal of the formed foam may be repeated. Suitably, the foam is removed about 5 hours after mixing in step (c) is complete. The removal of the foam can be carried out by preliminary evacuation of the mixture or simultaneously with the degassing of the mixture. Such degassing may include agitating the mixture during heating to facilitate release of gas bubbles from the mixture. Other forms of degassing, such as sonication and vibration, at atmospheric pressure or under reduced pressure (vacuum) may be used instead or in addition and are also contemplated. Suitably, the mixture is degassed for about 2 hours to about 8 hours. Suitably from about 2 hours to about 6 hours. Most suitably, degassing is carried out for about 3 to about 4 hours. Suitably, degassing occurs in step (c) with heating.

The degassing of the mixture in step (c) allows for the removal of gas bubbles which, if left in the mixture, would reduce the transparency/translucency of the final composition or product formed therefrom.

After degassing and before drying, the concentration of the mixture may be suitable for direct drying or may be adjusted at this stage by adding water or other suitable polar solvent. At the end of step (c), the final concentration of the components may be in the range of 4 to 8 wt%, suitably 6 wt% seaweed extract, in the range of between 0.5 to 3 wt%, suitably 2 wt% water-soluble cellulose derivative and in the range of between 80 to 95 wt% water or other suitable polar solvent. All weight percentages being based on the total weight of the mixture at the end of step (c).

Mixtures with higher viscosities (prior to pouring into molds) will, when dry, result in thicker, more structural products, such as structural packaging materials, which are the first choice for most such applications. If the mixture prepared has a lower viscosity (before pouring into the mould), the resulting (dried) product, for example a film of packaging material, is generally thinner.

In embodiments, the method may comprise the step of adding one or more additives as defined elsewhere herein in steps (a), (b) and/or (c). The additive may be a dye or a pigment. These may impart color to the composition. Other additives may be salts as described above or glycerol. Suitably, salt or glycerol may be added to the mixture produced in step (c).

In another aspect, the invention relates to a method of producing a product as defined above. The method comprises steps (a) - (d) for forming the composition as defined above, and between steps (c) and (d) forming the mixture into a product shape.

The forming step may comprise molding or vacuum forming, although vacuum forming is generally only suitable for low seaweed extract compositions. Suitably, moulding may comprise casting, extrusion, compression moulding, injection moulding, rotational moulding or slip moulding. The most suitable moulding is compression moulding.

The molding technique may be selected to be suitable for large scale manufacturing, such as injection molding, compression molding or casting. A particular feature of the present invention is that the composition after preparation is relatively fluid and requires cooling and/or drying to form a material having the desired structural rigidity for a given product. While any of the above molding techniques may accommodate this, it has been found that compression molding and injection molding are particularly beneficial because the fluid composition may be deposited in the female mold prior to insertion into the male part (or mandrel) of the mold, thereby ensuring a controlled and uniformly distributed wall of the desired material thickness for a given product.

The material is typically added to the mold at a temperature above ambient to maintain the fluidity of the mixture. Suitably, the material is added to the mould at about 80 ℃ to 100 ℃, or more suitably 85 ℃ to 95 ℃. In embodiments, the material is added to the mold at about 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃, or 100 ℃. Suitably, the material is added to the mould at about 90 ℃. Below 70 c, the material may solidify, complicating molding or preventing proper molding.

When the liquid hydrogel cools and solidifies (after an appropriate time), the mold can then be separated and material left on at least one of the male or female portions of the mold, suitably the male portion (or mandrel) of the mold, to expose the cured composition to a drying environment to facilitate drying of the composition by evaporation of solvent, suitably water, from the cured gel. This drying process is typically continued until the composition becomes suitably rigid and self-supporting (by the drying process) so that it can be demolded to give the finished product. In some embodiments, the finished product has an appearance and characteristics comparable to PET plastics and PLA bioplastics. Furthermore, by retaining the cured gel on the male mold or mandrel during drying, shrinkage can be controlled and the finished product prevented from deforming (fig. 2).

In embodiments where the material is at least partially cooled in the mold, the composition is cooled to ambient temperature in the mold. Suitably, the composition may be cooled to a temperature below about 40 ℃ and above about 0 ℃. Suitably, the composition may be cooled to a temperature of about or exactly 30 ℃, 25 ℃, 20 ℃, 15 ℃, 10 ℃, 5 ℃.

In embodiments, the compositions of the present invention may be dried at room temperature and pressure. In embodiments, the composition may be dried in a controlled atmosphere environment, such as a low humidity environment or an environment having a humidity below ambient atmosphere, or under reduced atmospheric pressure, or under Ultraviolet (UV) light. Suitably, the manner of drying the composition may be in a vacuum oven, wherein the boiling point of water is reduced. This method is typically used for heat sensitive materials, such as the compositions of the present invention.

In addition to or in place of other drying methods, including those described above, heat may be used to further facilitate drying, but care must be taken not to melt the composition. In embodiments, the composition may be dried at a temperature of less than 60 ℃. Suitably, the composition may be dried at a temperature of between 30 ℃ and 60 ℃, or between 30 ℃ and 50 ℃, most suitably between 40 ℃. Suitably, the composition may be dried at a temperature of at least 30 ℃, 40 ℃ or 50 ℃. Suitably, the composition may be dried at a temperature of up to 60 ℃, 50 ℃, 40 ℃ or 30 ℃. In a reduced pressure drying environment, such as a vacuum oven, the required heating temperature may be reduced compared to drying at ambient atmospheric conditions.

In other embodiments, or in addition to those described above, the atmosphere above the mold containing the composition during the drying step may have a low relative humidity. Suitably, the relative humidity of the atmosphere above the composition may be about 70% or less. Suitably, the relative humidity of the atmosphere above the mould may be between 50% and 70%. Suitably, the relative humidity of the atmosphere above the mold may be about 60%, 55%, 50%, 45%, 40% or less.

In other embodiments, or in addition to those described above, the atmosphere above the mold containing the composition during the drying step may be at a pressure below ambient atmospheric pressure. Suitably, the atmospheric pressure above the mould during the drying step may be from 7 to 14 psi. Suitably, the pressure is at most 14psi, 13psi, 12psi, 11psi, 10psi, 9psi, 8psi, 7psi or less. Suitably, the pressure is at least 1psi, 2psi, 3psi, 4psi, 5psi, 6psi, 7psi, or higher.

Drying may be, for example, at room temperature, in a dehumidifier (up to 60 ℃) and/or in a vacuum oven (up to 60 ℃).

As best shown in fig. 3, in embodiments, the product may be reprocessed from a sheet of the composition having a suitable thickness. Reprocessing may include first forming a sheet of the composition of the invention, for example by pouring or depositing the mixture from step (c) above onto a flat surface, followed by cooling, and then drying the composition in a similar manner as described above in the context of press forming. In embodiments, the sheet is stapled on a flat surface, suitably by a suitable weight, such as a plate, to prevent shrinkage or deformation during drying. The sheet formed from the composition may then be steamed and/or heated in the presence of water, for example by being placed in hot water (above 80 ℃) for a suitable length of time, for example 5 seconds, and then re-worked into the desired shape. Suitably, the rework may be performed by a process of wrapping the sheet and then holding to the profile of a suitable former. Once the composition has cooled and/or dried sufficiently to form a product, the former may be removed. Vacuum forming can be used for rework by applying a vacuum to the sheet to draw it tightly onto a suitable former. For reworking, the sheet may have a suitable thickness of from 0.01mm to 5mm, more particularly from 0.01mm to 1mm, even more particularly from 0.05mm to 0.5mm, prior to reworking (i.e. in its shortest dimension).

In another aspect, the invention also relates to a method of dissolving, degrading, biodegrading or otherwise safely decomposing the composition or product of the earlier aspect of the invention described above. The option of dissolving the composition in water may be important for waste stream management, in addition to the ability of the material to be completely biodegraded rapidly (less than 4-6 months) in a range of natural and man-made environments, such as industrial composting facilities. This is particularly relevant for low seaweed compositions which have a higher water solubility than high seaweed compositions.

In particular, if a consumer mistakenly discards a composition in a recycling bin (the composition is intended for a composting waste stream), the ability of the composition to readily dissolve in water may be beneficial to help prevent the product composition from contaminating the plastic recycling waste stream by facilitating separation of the recyclable plastic when it is immersed in a liquid and washed prior to processing.

In the low seaweed extract embodiment of the composition or product derived therefrom, the method of dissolving the composition or product comprises the step of contacting the composition or product with liquid water at a temperature of 40 ℃ or less, more particularly 30 ℃ or less, even more particularly 25 ℃ or less. In this embodiment of the method, the composition may comprise the seaweed extract in an amount of 1-10 wt%, more particularly 2-5 wt%. In particular, the composition may comprise the water-soluble cellulose derivative in an amount of 70-95 wt.%, more particularly 80-95 wt.%. More particularly, the composition may comprise from 2 to 20% by weight, even more particularly from 4 to 15% by weight of water. Suitably, the composition is contacted with liquid water at a temperature of 30 ℃ for 15 to 30 minutes, while continuously stirring to effect dissolution.

In the high algae extract embodiment of the composition or product derived therefrom, the method of solubilizing the composition or product comprises the step of contacting the composition or product with liquid water at a temperature of at least 50 ℃, more particularly at least 70 ℃, even more particularly at least 85 ℃. In the method, the composition may comprise the seaweed extract in an amount of 40-90 wt%, more particularly 60-90 wt%. In particular, the composition may comprise the water-soluble cellulose derivative in an amount of 5-50 wt.%, more particularly 10-40 wt.%. More particularly, the composition may comprise from 1 to 20 wt%, even more particularly from 2 to 15 wt% of water. Suitably, the composition is contacted with water at a temperature of 90 ℃ for 30 minutes to 1 hour with continuous stirring to effect dissolution.

The ability to dissolve the composition of the present invention or products derived therefrom into harmless, food safe, water soluble components has the advantage of providing a simple and reliable waste treatment stream. If necessary, the composition and/or product will biodegrade completely rapidly in the environment. When disposed of by appropriate management of waste streams, the above-described methods provide a method of easily disposing of compositions or products. The ability of a composition to dissolve in water, depending on its temperature, allows for the selection of a particular composition for a given use, depending on the environment, its intended time scale, and the intended waste stream for that use.

Examples

Example 1 specific Process for the preparation of the composition according to the invention

Kappa carrageenan (32.5g) in powder form was added to 510g of water (20 ℃ C.) and mixed for 5 minutes. The resulting paste was heated to 80 ℃ in a hot water bath (80 ℃). As the temperature of the mixture rises and reaches 80 ℃, it becomes a liquid gel (hydrogel). The mixture was kept at 80 ℃ for 1 hour.

In a separate container, methylcellulose (MC, 6.5g) was added to 40g of hot water (80 ℃) and then mixed for a short period of time (about 10 seconds) to form a liquid gel.

The hot MC gel was then added to the hot Kappa carrageenan gel. Potassium chloride (1.3g) was then added to the combined mixture before stirring for 20 minutes. The prepared mixture was placed in a hot water bath (80 ℃) for 7 hours. After 7 hours, the mixture had the appearance of a liquid gel and foam was collected on the surface of the mixture. The foam was collected and removed from the hydrogel mixture.

The packaging container was produced by pouring the prepared solution into a female mold at 80 ℃. The male mold was then pressed into the female mold (i.e., press-formed) and the solution was allowed to cool to 25 c to solidify the hydrogel. The mold was then separated and the cured gel adhered to the male part of the mold was then dried at 60 ℃ under ambient pressure and humidity until it was completely dry (about 8 hours). The final composition had a dry and translucent finish.

The resulting package contained 71.3% Kappa carrageenan, 10% water, 14.3% methylcellulose, and 3% potassium chloride (weight content, based on the total weight of the composition).

The relative weight percent is calculated based on the water content determined by comparing the weight of the cured gel before molding to the final weight of the product. It is assumed that there is no loss of material quality of MC, CK and potassium chloride during the preparation process, or loss of water during the preparation process before drying.

The resulting package is completely biodegradable, edible, and can be dissolved in hot water at 80 ℃ and above.

Example 2 specific Process for the preparation of the composition according to the invention

Kappa carrageenan (21.6g) in powder form was added to 340g of water (10 ℃ C.) and then mixed for 15 seconds. The resulting paste was placed in a hot water bath (90 ℃) for 1 hour and heated to 90 ℃. The solution increases in viscosity and becomes a liquid gel.

In a separate container, methylcellulose (MC, 4g) was added to 22g of hot water (90 ℃) and mixed for a short period of time (about 5 seconds) to form a liquid gel.

The hot MC gel was then added to the hot Kappa carrageenan gel. The mixture was stirred for 15 minutes and then placed in a hot water bath (90 ℃) for 4 hours. After 4 hours, the mixture had the appearance of a liquid gel and foam was collected on the surface of the mixture. The foam was collected and removed from the hydrogel mixture.

The packaging container was produced by pouring the prepared solution into a female mold at 90 ℃. The male mold is then pressed into the female mold (i.e., press forming) and the solution is allowed to cool to 30 c, thereby solidifying the material. The mold was then separated and the cured gel solution still attached to the male mold was then dried at 50 ℃ for 10 hours at ambient pressure and humidity. The dried material has a dry and translucent finish.

The resulting package contained 80% Kappa carrageenan, 5% water and 15% methylcellulose (content by weight, based on the total weight of the composition).

The relative weight percent is calculated based on the water content determined by comparing the weight of the cured gel before molding to the final weight of the product. It is assumed that there is no loss of material quality of MC and CK during the preparation process, or no loss of water during the preparation process before drying.

The resulting package is completely biodegradable, edible and dissolves in hot water at 100 ℃ within 1 hour.

Example 3 specific Process for preparing the composition according to the invention

Methylcellulose (MC, 30g) in powder form was added to 100ml of hot water (80 ℃) and mixed for a short period of time (about 15 seconds) to form a liquid gel. The resulting solution was placed in a hot water bath (80 ℃).

In a separate container, Kappa carrageenan (2g) in powder form was added to 25g of cold water (20 ℃) and then mixed for 15 seconds. The resulting paste was then heated to 80 ℃ in a water bath and then added to the MC gel. The resulting mixture was thoroughly mixed for 15 minutes and then left in a hot water bath at 80 ℃ for 4 hours, and then a liquid gel (hydrogel) was formed. The foam and bubbles generated during heating are removed from the surface of the mixture.

The packaging container was produced by pouring the prepared solution into a female mold at 80 ℃. The male mold was then pressed into the female mold (i.e., press formed) and the solution was allowed to cool to 10 ℃ to solidify. The female mold was separated and the cured gel solution attached to the male mold was then dried at 50 ℃ for 10 hours. The dried material has a dry, transparent finish like translucent PLA.

The resulting package contained 84% methylcellulose, 10% water and 5.6% Kappa carrageenan (content by weight, based on the total weight of the composition).

The relative weight percent is calculated based on the water content determined by comparing the weight of the cured gel before molding to the final weight of the product. It is assumed that there is no loss of material quality of MC and CK during the preparation process, or no loss of water during the preparation process before drying.

The resulting package is completely biodegradable, edible and dissolves after 1 hour of continuous mixing in cold water at 30 ℃.

Example 4 specific Process for preparing the composition according to the invention

Methylcellulose (MC, 35g) in powder form was added to 100ml of hot water (90 ℃) and mixed for a short period of time (approximately 5 seconds). The resulting gel was placed in a hot water bath (90 ℃).

In a separate container, Kappa carrageenan (1g) in powder form was added to 25 ml of cold water (10 ℃) and mixed for a short period of time (about 10 seconds). The resulting paste was heated to 90 ℃ in a water bath and then added to the MC solution. Potassium chloride (1g) was then added to the solution. The resulting mixture was thoroughly mixed for 10 minutes and then left in a hot water bath at 90 ℃ for 4 hours, and then a liquid gel (hydrogel) was formed.

Pouring the prepared hydrogel into a female die at 90 ℃ to prepare a packaging container. The male mold was then pressed into the female mold (i.e., press formed) and the solution was allowed to cool to 10 ℃ to solidify. The mold was separated and the cured gel solution attached to the male mold was then dried at room temperature for two days. The dried material had a dry, transparent finish like translucent PET.

The resulting composition is completely biodegradable, edible and dissolves in cold water at 30 ℃ within 30 minutes with continuous mixing.

The resulting package contained 85% methylcellulose, 10% water, 2.5% Kappa carrageenan and 2.5% potassium chloride (weight content, based on the total weight of the composition).

The relative weight percentages are calculated based on the water content determined by comparing the weight of the cured gel before molding and the final weight of the dried product. It is assumed that there is no loss of material quality of MC, CK and potassium chloride during the preparation process, or loss of water during the preparation process before drying.

Example 5 general Process for preparing compositions according to the invention

Kappa carrageenan (32.4 g) in powder form was added to 510g of water (25 ℃). The resulting gel was filled in a double layer steamer and heated between 90 ℃ and 100 ℃ for 2 hours.

In a separate vessel, methylcellulose (MC, 4g) was added to 22.2ml of hot water (95 ℃) and stirred for a short time (about 10 seconds). The resulting gel was then added to the CK hydrogel in a double cooker and mixed for 15 minutes. The heating was continued for 6 hours, during which time the mixture was gradually degassed by the action of heat. After removal of the foam formed, the mixture is ready for moulding.

The final approximate formulation of the composition was 5.7 wt% Kappa carrageenan, 0.6 wt% methylcellulose, and 93.7 wt% water (weight content, based on the total weight of the composition).

Packaging containers are produced by dosing hot material into a pressing (female) mould before the mould is fully assembled. The mixture in the mold was then allowed to cool to ambient temperature over 15-20 minutes. Before the female part of the mold is removed to expose the material on the male part of the mold for drying. As shown in fig. 2, the material must remain on the mold of the product to prevent excessive shrinkage and to maintain its shape when dried.

The drying of the product is carried out in two stages. Stage 1 involves drying in an ambient atmosphere at 60 c for 8 to 12 hours. The product was dried at 50 ℃ for up to 6 hours in stage 2 after stage 1. The product remains on the male part of the mold throughout the drying process.

The product is then trimmed and demolded from the male part of the mold before being cleaned with ethanol to provide a finished cup.

The resulting package contained 80% Kappa carrageenan, 10% methylcellulose and 10% water (content by weight, based on the total weight of the composition).

The relative weight percent is calculated based on the water content determined by comparing the weight of the cured gel before molding to the final weight of the product. It is assumed that there is no loss of material quality of MC, CK and potassium chloride during the preparation process, or loss of water during the preparation process before drying.

Example 6 preparation of exemplary compositions

Compositions 2 to 10 and 12 to 13 according to the invention were prepared according to the general method of example 5, with appropriate replacement and/or modification of the proportions of the components.

Comparative compositions 1 and 11 not according to the invention were also prepared according to the general method of example 5, with appropriate replacement and/or adjustment of the proportions of the components.

A summary of compositions 1 to 13 is provided in table 1:

TABLE 1

Example 7 visual appearance of the composition

The visual appearance of the exemplary composition of example 6 was tested using the following method.

The photometer (Urciri MT-912) was placed in a light box (Heorryn 40/40/40 cm). The sensor of the photometer was completely covered with a sample of material of each component, having a standard thickness of 0.3mm, and then a light reading (in Lux) was taken and recorded for each sample.

The results are shown in table 2 and fig. 14:

TABLE 2

Each of compositions 1 to 13 allows a certain degree of light transmission, i.e. is translucent. Compositions 1 to 11 comprising seaweed extract kappa carrageenan have a high level of light transmittance.

Compositions 2 to 10 comprising kappa carrageenan and methylcellulose have low pigmentation levels. Composition 1 containing only kappa-type carrageenan and compositions 11 (with increased amounts of MC)12 to 13 containing the same amounts of methylcellulose and seaweed extract agar or iota-type carrageenan had moderate or high pigmentation levels.

Compositions 1 to 10 had a smooth and uniform homogeneity, whereas composition 11, which contained equal amounts of methylcellulose and kappa-type carrageenan, and compositions 12 and 13, which contained seaweed extract agar or iota-type carrageenan with a small amount of MC, had a coarse or flaky and varying homogeneity.

From the above, it follows that the visual appearance of the composition according to the invention is best for compositions comprising the kappa-type carrageenan and methylcellulose in relative proportions.

Figure 14 clearly shows that the pigmentation of composition 4(B) was significantly lower than that of composition 11(C), composition 1(a) and composition 12(D) (in order).

Example 8 visual appearance as a function of thickness

The visual appearance of composition 4 (example 6) as a function of the thickness of the composition was measured according to the following method:

the photometer (Urciri MT-912) was placed in a light box (Heorryn 40/40/40 cm). The sensor of the photometer is completely covered with each thickness of material sample, and then a light reading (in lux) is taken and recorded for each sample.

The results are provided in table 3:

TABLE 3

As expected, the transmittance decreased uniformly with increasing thickness. In addition, pigmentation and transparency decrease with increasing thickness. However, even at the highest thickness of 0.5mm, the material of composition 4 provides an excellent visual appearance similar to petroleum-based clear plastics (such as PET) or bioplastics (such as PLA).

Example 9 Water absorption

The following method was used to test the water absorption properties of the exemplary composition of example 6.

Samples of material for each composition were prepared in uniform size of 5mm/90mm/0.3mm to form strips weighing about 0.3g each. Each strip was weighed (Pocket Scale, model: PS-200B) and then immersed completely in a beaker containing 250ml of tap water for 24 hours at room temperature. Each strip was then removed from its beaker and the residual surface water on each strip was removed. The weight of each strip was then recorded and the weight percent change was calculated.

The results are shown in Table 4:

TABLE 4

Each of compositions 1 to 11 exhibited high levels of water absorption. The results show that when the seaweed extract is kappa carrageenan, there is a tendency for a better overall water absorption with increasing seaweed content. Compositions 12 and 13, which contained seaweed extract agar and iota-type carrageenan, respectively, exhibited a lesser degree of water absorption than those compositions containing kappa-type carrageenan.

Since water absorption is associated with improved biodegradability and extended shelf life, the expected biodegradability and extended shelf life performance may decrease from composition 1 to composition 13.

Example 10 moldability

The following method was used to test the ability to mold the exemplary composition of example 6.

The composition is formed in a press die comprising a male component and a female component. After removing one part of the mold, the adhesive properties of each composition in the gel state can be observed before drying. It is noted how different compositions adhere to the mould to a lesser or greater extent.

The results are shown in table 5 and fig. 15:

a +++ -highly moldable, easily flowing into a mold; stable on curing

+ + ═ moldable, with slight difficulties encountered during deposition or curing in the mold

Can be molded, encounters greater difficulty in deposition or curing in a mold table 5

The composition adhering to the mold makes it difficult to fill the mold uniformly. Further, when a part of the mold is removed and adhered to the material, the molded product tends to be damaged.

Compositions 1 to 11 comprising kappa carrageenan all showed acceptable moldability, but it was noted that the use of higher MC compositions, especially composition 11, had adhesion to the mold.

Compositions 12 and 13, which contained agar and iota carrageenan, respectively, had lower viscosities than kappa carrageenan compositions with the same amount of methylcellulose mixture, and therefore they required longer time to form a solid gel before removing the mold for drying. Composition 13(iota carrageenan) did not form a solid gel and the surface was very sticky, so it had high adhesion to the mould. Composition 12 (agar) formed a solid gel but the surface cracked during drying.

FIG. 15 shows a cup formed from (A) composition 4 (kappa-carrageenan), (B) composition 12 (iota-carrageenan), and (C) composition 13 (agar). It is clearly seen that all of the compositions can be molded to form rigid and load-bearing structures. The cups formed from kappa carrageenan (A) have significantly fewer molding defects than the cups formed from agar (B), which cracks when dry, or iota carrageenan (C), which exhibits instability when cured, leading to wrinkling of the top edge.

Example 11 breaking Strength of the composition

The exemplary composition of example 6 was tested for breaking strength using the following method.

Samples of material for each composition were prepared in uniform size of 5mm/90mm/0.3mm to form strips. At their short sides, the strips are clamped, covering each end: a fixing clip is fixed; the other is attached to a variable weight, thereby placing the strap under tension. With this arrangement, the load each strip was subjected to before failure was recorded by incrementally increasing the tensile stress on each strip in turn.

The results are shown in Table 6:

TABLE 6

The results show that all compositions (1 to 13) exhibit good breaking strength. Compositions 1 to 11 comprising kappa-type carrageenan appear to show better breaking strength than those comprising agar (composition 12) or iota-type carrageenan (composition 13).

Breaking strength is an alternative measure of the tensile strength of a material, thus providing a measure of the ability of the composition to be formed into a thin-walled product that is rigid and has good load-bearing properties.

EXAMPLE 12 reprocessing of the compositions

A sheet of the composition of the present invention may be formed by pouring the prepared liquid composition of example 6 into a suitable shallow pan and drying in a similar manner to the product of example 6. For sheet products, the cooling composition needs to be pinned to the surface on which it is located, for example by a weighted plate above it, to prevent deformation and/or shrinkage.

As shown in fig. 3, the composition in sheet form may be reprocessed after drying to form a product. In particular, the dried composition becomes malleable upon exposure to heat, moisture and/or pressure and may be molded and/or adhered to itself or a suitable former or jig. Once the heat, moisture and/or pressure are removed from the former, the product may be removed from the former or fixture.

Example 13 biodegradation of the compositions example

As shown in fig. 4-6 and 13, the compositions of the present invention biodegrade rapidly under a range of environmental conditions. After two months, the biodegradation process progressed smoothly in home compost (fig. 4), immersed in sea water for 4 weeks (fig. 5), and open compost for 4 weeks (fig. 6). As shown in fig. 13, degradation under anaerobic conditions was much less due to the reduced ability of certain microorganisms to act on the material, however, significant biological activity was visible and appeared to be decomposing the composition.

Example 14 extension of shelf life

As shown in FIGS. 10 to 12, perishable food items stored in packages or structural Stock Keeping Units (SKUs) made from the compositions of the present invention exhibit a significantly extended shelf life.

Fig. 10 shows comparative examples of storage of soft fruits (strawberries) after 1-2 days (column a), 3 days (column B) and 4 days (column C) in a packaging formed from a composition of the present invention (bottom line) compared to a packaging formed from petroleum-derived PET (top line) under non-refrigerated ambient conditions. It is clear that after 3 days condensation occurred on the inner wall of the PET package, increasing by 4 days. There is no significant condensation on the packages formed by the present invention. Since condensation implies high humidity which promotes bacterial and fungal growth, it is suggested that the packaging of the present invention will result in a lower rate of bacterial or fungal growth on the food product contained therein due to the high water absorption of the present composition.

Fig. 11 shows comparative examples of storage of soft fruit (raspberry) after 1 day (row a), 2 days (row B), 3 days (row C), 4 days (row D), 5 days (row E) and 6 days (row F) under non-refrigerated ambient conditions for a packaging formed from petroleum derived PET (left column). It is clear that the raspberry in the PET cup started to mold on day three, whereas the raspberry in the cup formed from the composition of the invention did not mold until day 6, increasing shelf life by 100%.

Figure 12 shows a piece of cheddar cheese which has been heat sealed in a bag made from a composition of the invention. The upper panel shows the cheese just after sealing, and the lower panel shows the same cheese stored for 1.5 years at non-refrigerated, ambient conditions and room temperature (about 20-25 ℃). After this time, there was no obvious sign of spoilage in the cheese.

Although specific embodiments of the invention have been disclosed herein in detail, this has been done by way of example only and is for the purpose of illustration only. The above embodiments are not intended to limit the scope of the present invention. The inventors expect various alterations, changes, and modifications to the invention without departing from the scope of the invention.