Biodegradable and barrier PVOH-based materials and products using them

Abstract

FIELD OF THE INVENTION This invention relates generally to compositions and processes for producing biodegradable polymer-based materials that exhibit water resistance and barrier properties.

Description

[Technical Field]

[0001] The present invention relates generally to compositions and processes for producing biodegradable polymer-based materials that exhibit barrier properties. [Background technology]

[0002] Biodegradable or water-soluble polymer films are environmentally friendly and are often used as new packaging materials. Some are used as functional packaging materials that are intentionally designed to biodegrade upon contact with water, soil, or compost, while others are designed to biodegrade within a certain period of time.

[0003] Polyvinyl alcohol (PVOH) coatings and films are used as laminates on a variety of substrates and have demonstrated barrier properties against oxygen, water vapor, grease, and oil permeation. However, PVOH is known to be highly soluble in water and to gradually dissolve and biodegrade in the presence of suitable microorganisms. While attempts to reduce, prevent, or decrease dissolution in the presence of humidity have been partially successful, attempts to time-control dissolution and biodegradation have been virtually unsuccessful. Summary of the Invention

[0004] No biodegradable materials are known that exhibit effective biodegradation in water and in the presence of suitable microorganisms while maintaining or improving high water resistance. This is because improving biodegradability reduces water resistance, and vice versa. The inventors' goal in the technology disclosed herein was to combine both properties in a single polymer material to improve water resistance while maintaining rapid biodegradability. The inventors' development disclosed herein was quite surprising because high water resistance and good oxygen barrier properties are generally correlated with high crystallinity and are therefore at odds with improved biodegradability.

[0005] One way to improve the water resistance of water-sensitive polymers such as PVOH is to crosslink the polymer. However, crosslinking alone is insufficient to achieve both biodegradability and water resistance. Crosslinking increases water resistance while simultaneously decreasing biodegradability. The inventors have discovered and demonstrated that crosslinking uncrosslinked PVOH of any type, grade, and molecular weight with ethylene-polyvinyl alcohol copolymers can produce polymeric materials with superior biodegradability, water resistance, low coefficient of friction, and low tack compared to PVOH alone or highly biodegradable materials such as cellulose, which is known and used as a standard for biodegradability and water solubility testing. Blending PVOH with ethylene-polyvinyl alcohol copolymers also improves processability during compounding and significantly reduces the plasticizer content.

[0006] Accordingly, the present invention contemplates a composition comprising polyvinyl alcohol (PVOH) and ethylene-polyvinyl alcohol copolymer (E-PVA) for producing a polymer that exhibits biodegradability in the presence of water, water resistance over time, and oxygen barrier properties (described herein in terms of oxygen transmission rate (OTR)).

[0007] In a first aspect, the present invention provides a composition comprising polyvinyl alcohol (PVOH), ethylene-polyvinyl alcohol copolymer (E-PVA), a plasticizer, and optionally a crosslinker. In some embodiments, the composition may further comprise at least one additive.

[0008] The present invention further provides a composite composition formed by mixing polyvinyl alcohol (PVOH), ethylene-polyvinyl alcohol copolymer (E-PVA), a plasticizer, and optionally at least one additive. The formulation of the composition can be provided in a solid form, such as a pellet form. The formulation can also be a cross-linked product of polyvinyl alcohol (PVOH), ethylene-polyvinyl alcohol copolymer (E-PVA), which in some embodiments is cross-linked with the plasticizer by cross-linking with at least one cross-linking agent. When the cross-linked product does not involve cross-linking of the plasticizer, the formulation can include the plasticizer and at least one additive.

[0009] The present invention further provides a composition for use in a process for manufacturing a thermoplastic polymer, the composition comprising polyvinyl alcohol (PVOH), ethylene-polyvinyl alcohol copolymer (E-PVA), a plasticizer, and optionally a crosslinker.

[0010] Also provided are thermoplastic PVOH / E-PVA polymers, which are blends or optionally crosslinked products of PVOH and ethylene-polyvinyl alcohol copolymers, which are biodegradable in water, water-resistant over time, and have good oxygen barrier properties.

[0011] As used herein, the term "biodegradation" or any linguistic variation thereof refers to the ability of a polymer to degrade in the presence of water, for example, under the conditions of ISO 14851 or ISO 14852. The biodegradability of the polymers of the invention is tested in water and compared to samples of polymers that do not contain E-PVA or have less than 10 mole % E-PVA, tested for the same period of time and under the same conditions.

[0012] As disclosed herein, the biodegradability of the polymers of the present invention, formed as blends of materials or as crosslinked polymers, was measured relative to cellulose as a highly water-soluble standard and relative to PVOH (no E-PVA or less than 10% E-PVA). As demonstrated herein, polymers formed in accordance with the present invention exhibited at least a 20% increase in biodegradability compared to PVOH alone. In other words, the amount of polymer that biodegraded over time was greater than the amount of PVOH that biodegraded during the same degradation period.

[0013] The percent (%) biodegradation reflects the total weight degraded under standard industry-accepted measurement conditions, as described above. The test is performed on a finely ground powder of the composition and is expressed as O consumed or CO evolved relative to the theoretical oxygen demand (THOD) or theoretical total organic content (TOC).

[0014] In some embodiments, the products of the invention exhibit at least a 20% improved biodegradability compared to the biodegradability of a PVOH-based product (without E-PVA) measured under the same conditions when measured according to ISO 14851 or ISO 14852. In some embodiments, the improvement is 20, 25, 30, 35, 40, 45, 50, 55, 60, or 65%.

[0015] "Water resistance over time" refers to the time it takes for a film formed from a composition of the present invention to deform when three successive drops of water (each drop being approximately 100-110 μl) are placed on a horizontally placed 50-micron film. The time until the film begins to deform is measured in seconds or minutes. As shown in Table 1, a reference composition without E-PVA exhibits very low water resistance, deforming in less than 15 seconds, whereas comparative formulations containing E-PVA (e.g., at least 20% by weight E-PVA) exhibit deformation after much longer periods of time, e.g., 15 minutes or more, following exposure to water droplets placed on the film. Therefore, for purposes of the present invention, water resistance is defined herein as the time it takes for a 50-micron film formed from the material to deform when exposed to three drops of water. Other film thicknesses may be used. Other methods or tests for determining water resistance may also be utilized.

[0016] Oxygen transmission rate (OTR) is the rate at which oxygen gas permeates a solid material in a given time. A solid material considered an effective oxygen barrier has an OTR value between 10 and 1 cm when measured at moderate to high relative humidity (RH). 3 / m 2* Less than a day.

[0017] As demonstrated herein, at 50% RH, a 50 micron film formed with a formulation without E-PVA was observed to be 10 cm 3 / m 2* day, whereas in the case of comparable formulations according to the invention containing E-PVA (tested with at least 15% E-PVA), the OTR values ​​recorded were 6 cm 3 / m 2* day~0.9cm 3 / m 2* Similarly, at 65% RH, the OTR value was approximately 90 cm for the formulation without E-PVA. 3 / m 2* 43cm from day 3 / m 2* day~10cm 3 / m 2* It decreased over the course of the day.

[0018] The amount of each component in the compositions of the present invention may vary. This amount depends, among other things, on the final polymer formed from the composition, the desired polymer properties, and the attributes sought to be enhanced or minimized. Generally speaking, all compositions of the present invention incorporate the disclosed components to achieve the following benefits compared to an equivalent PVOH composition lacking the all-EPVA copolymer: (1) improved biodegradability in the presence of water (at least a 15% increase in absolute biodegradation rate when the material is tested according to ISO 14851 or ISO 14852 (absolute biodegradation rate is defined as the % biodegradation rate at which the material reaches a plateau, as shown in Figure 1)); (2) improved water resistance (e.g., an increase from less than 30 seconds to more than 60 seconds when tested according to the methods described herein); and (3) enhanced or increased oxygen barrier properties (at least a 50% reduction in OTR for a defined film thickness, particularly when E-PVA is present in an amount of at least 15%).

[0019] As used herein, "PVOH" refers to polyvinyl alcohol, which may be produced by saponification of polyvinyl acetate homopolymers or copolymers, or by synthetic or semi-synthetic methods. PVOH may be of any grade, degree of hydrolysis, or molecular weight. The PVOH used in the compositions of the present invention may be crosslinked or uncrosslinked. In some configurations where the PVOH is uncrosslinked, the PVOH may be selected from among water-soluble materials containing primarily fully, partially, or sub-partially hydrolyzed, non-internal associated or non-linked vinyl organic ester polymers.

[0020] In some embodiments, the PVOH is not crosslinked. In some embodiments, the compositions of the present invention do not include crosslinked PVOH.

[0021] PVOH may be provided as a single grade or a combination of grades. PVOH is typically selected from hydrolyzed PVOH with a degree of hydrolysis of 86 to 99%. Alternatively or additionally, PVOH may be selected from those with a degree of polymerization in the range of 500 to 3,000.

[0022] The PVOH may be partially hydrolyzed PVOH having a degree of polymerization between 300 and 2,000. In some embodiments, the PVOH is selected to have a degree of polymerization between 800 and 1400, or a molecular weight between 30 KDa and 70 KDa, or a molecular weight between 35 KDa and 62 KDa.

[0023] In some embodiments, the PVOH is selected from among PVOH having a degree of hydrolysis between 98-99% and a degree of polymerization between about 800-1,700, PVOH having a degree of hydrolysis between 86-89% and a degree of polymerization between about 1400-2,600, and PVOH having a degree of hydrolysis between 86-89% and a degree of polymerization between 500-800.

[0024] In some embodiments, the PVOH may be selected from one or more of the following grades: (i) Grade 1: Partially hydrolyzed grades having a degree of hydrolysis of 86-90 mol % and a degree of polymerization (DP) of 300-2000, or 500-1400, e.g., 500, 800, or 1400; (ii) Grade 2: Medium hydrolysis grade with a degree of hydrolysis of 91-97%, and (iii) Grade 3: fully hydrolyzed grades having a degree of hydrolysis of 98% to 99% (or 100%) and a degree of polymerization of 300-2000, or 500-1700, e.g., 1700.

[0025] The amount of PVOH used can be 40-90 wt% (based on the total weight of the composition). In some embodiments, the amount of PVOH is 40-90, 40-85, 40-80, 40-75, 40-70, 40-65, 40-60, 40-55, 40-50, 40-45, 45-90, 45-85, 45-80, 45-75, 45-70, 45-65, 45-60, 45-55, 50-90, 50-85, 50-80, 50-75, 50-65, 50-60, 60-90, 60-80, 70-90, or 80-90 wt%.

[0026] Ethylene-polyvinyl alcohol copolymer (E-PVA) is a polyvinyl alcohol copolymer with ethylene as the comonomer. This material is also known as ethylene-modified polyvinyl alcohol or ethylene-modified copolymer PVOH.

[0027] E-PVA is a copolymer of hydrophobic ethylene monomer (E) and hydrophilic PVOH, and is more hydrophobic than PVOH, significantly reducing moisture absorption at average temperatures. This material not only reduces moisture absorption, but also features higher water resistance and excellent gas barrier properties, and unlike regular PVOH, maintains excellent performance even under high humidity conditions.

[0028] The ethylene content in the E-PVA copolymer may vary. Typically, the compositions of the present invention may include an E-PVA having an ethylene content of 15 mol% or less. In some embodiments, the ethylene content is not zero, but is less than 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, or 2% of the E-PVA. The ethylene content may be 1-15 mol%, and in other embodiments, the ethylene content may be 2-15, 3-15, 4-15, 5-15, 6-15, 7-15, 8-15, 9-15, 10-15, 11-15, 12-15, 5-10, 6-10, 7-10, 8-10, 5-9, 5-8, or 5-7 mol%.

[0029] The degree of polymerization (DP) and degree of hydrolysis (DH) of the E-PVA may also vary. Typically, the compositions of the present invention may contain E-PVA with a DP of 300 to 2,000 and / or a DH of 86 to 99.6%.

[0030] Generally, E-PVA is available in a variety of grades. The grades may differ in the degree of hydrolysis of the E-PVA. The grades are as follows: 1) Grade 1: Degree of polymerization (DP) is 300-800; 2) Grade 2: degree of polymerization (DP) 800-1500; 3) Grade 3: Degree of polymerization (DP) is 1500-2000.

[0031] The degree of hydrolysis for all grades of E-PVA is 86-99.6 mol%, or 92-99.6 mol%, or 94-99.6 mol%, or 96-99.6 mol%, or 98-99.6 mol%, with each value between 86-99.6 mol% constituting a separate embodiment.

[0032] In some embodiments, the E-PVA has a DP of 300 to 2,000, 300 to 1,500, 300 to 1,000, 300 to 900, 300 to 800, 300 to 700, 300 to 600, 300 to 500, 500 to 2,000, 500 to 1,500, 500 to 1,000, 500 to 900, 500 to 800, 1,000 The DP may be selected from those having a DP (±10%) of up to 2,000, 1,000 to 1,500, or about 300, 400, 500, 600, 700, 800, 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 1,600, 1,700, 1,800, 1,900, or 2,000.

[0033] In some embodiments, the E-PVA may be selected from Grade 1, Grade 2, or Grade 3 E-PVA as defined herein.

[0034] In some embodiments, the E-PVA may be selected from those having a DH of 86-99.5%, 86-99, 86-95, 86-90, 90-99.5, 95-99.5, or a DH of about 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 99.5% (±10%).

[0035] In some embodiments, the E-PVA is selected from E-PVA having a DH of 86-90% and a DP of 300-2,000.

[0036] In some embodiments, the E-PVA has a DP of 300-1,500, 300-1,000, 300-900, 300-800, 300-700, 300-600, 300-500, 500-2,000, 500-1,500, 500-1,000, 500-900, 500-800, 1,000-2,000, 1,000-1,500, or a DP of about 300, 400, 500, 600, 700, 800, 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 2,000, 2,500, 3,600, 3,700, 4,000, 5,000, 6,000, 7,000, 8,000, 9,000, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 2,600, 2,700, 3,800, 3,900, 4,000, 4,100, 4,100, 5,200, 5,300, 5,400, 5,500, 6,000, 7,000, 8,000, 9,000, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 2,600, 2,7 , 500, 1600, 1700, 1800, 1900, or 2000 (±10%), where each value or range constitutes a separate and independent embodiment, and E-PVA having a DP of 86-99, 86-95, 86-90, 90-99.5, 95, and 99.5, or a DH of about 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 99.5% (±10%), where each value or range constitutes a separate and independent embodiment. Any combination of the above DP and DH is a separate and independent embodiment.

[0037] In some embodiments, the compositions and polymers of the present invention are formed from Grade 1 PVOH and Grade 1, 2, and / or 3 E-PVA, as defined herein.

[0038] In some embodiments, the compositions and polymers of the present invention are formed from Grade 2 PVOH and Grade 1, 2, and / or 3 E-PVA, as defined herein.

[0039] In some embodiments, the compositions and polymers of the present invention are formed from Grade 3 PVOH and Grade 1, 2, and / or 3 E-PVA, as defined herein.

[0040] In some embodiments, the compositions and polymers of the present invention are formed from one or more PVOH of grade 1, 2, or 3, as defined herein, and E-PVA of grade 1.

[0041] In some embodiments, the compositions and polymers of the present invention are formed from one or more PVOH of grade 1, 2, or 3, as defined herein, and E-PVA of grade 2.

[0042] In some embodiments, the compositions and polymers of the present invention are formed from one or more PVOH of grade 1, 2, or 3, as defined herein, and E-PVA of grade 3.

[0043] In some embodiments, the compositions and polymers of the present invention comprise: I) PVOH, (i) Partially hydrolyzed grades having a degree of hydrolysis of 86-90% and a degree of polymerization (DP) of 300-2000, or 500-1400, for example, 500, 800, or 1400; (ii) medium hydrolysis grade with a degree of hydrolysis of 91-97%, and (iii) PVOH selected from one or more of the following: a fully hydrolyzed grade having a degree of hydrolysis of 98% to 99% (or 100%) and a degree of polymerization of 300 to 2000, or 500 to 1700, e.g., 1700; II) E-PVA, (i) DP is 300-1,500, 300-1,000, 300-900, 300-800, 300-700, 300-600, 300-500, 500-2,000, 500-1,500, 500-1,000, 500-900, 500-800, 1,000-2,000, 1,000-1,500, and or about 300, 400, 500, 600, 700, 800, 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 1,600, 1,700, 1,800, 1,900, or 2,000 (±10%), where each value or range constitutes a separate and independent embodiment; and (ii) an E-PVA having a DH of 86-99, 86-95, 86-90, 90-99.5, 95-99.5, or about 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 99.5% (±10%), where each value or range constitutes a separate and independent embodiment. Any combination of the above DP and DH is a separate and independent embodiment.

[0044] In some embodiments, the compositions and polymers of the present invention comprise: I) PVOH, which is a partially hydrolyzed grade PVOH having a degree of hydrolysis of 86 to 90% and a degree of polymerization (DP) of 300 to 2000, or 500 to 1400, for example, 500, 800, or 1400; II) E-PVA, (i) DP is 300-1,500, 300-1,000, 300-900, 300-800, 300-700, 300-600, 300-500, 500-2,000, 500-1,500, 500-1,000, 500-900, 500-800, 1,000-2,000, 1,000-1,500, and or about 300, 400, 500, 600, 700, 800, 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 1,600, 1,700, 1,800, 1,900, or 2,000 (±10%), where each value or range constitutes a separate and independent embodiment; and (ii) an E-PVA having a DH of 86-99, 86-95, 86-90, 90-99.5, 95-99.5, or about 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 99.5% (±10%), where each value or range constitutes a separate and independent embodiment. Any combination of the above DP and DH is a separate and independent embodiment.

[0045] In some embodiments, the compositions and polymers of the present invention comprise: I) PVOH, which is a medium hydrolysis grade PVOH having a hydrolysis degree of 91 to 97%, II) E-PVA, (i) DP is 300-1,500, 300-1,000, 300-900, 300-800, 300-700, 300-600, 300-500, 500-2,000, 500-1,500, 500-1,000, 500-900, 500-800, 1,000-2,000, 1,000-1,500, and or about 300, 400, 500, 600, 700, 800, 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 1,600, 1,700, 1,800, 1,900, or 2,000 (±10%), where each value or range constitutes a separate and independent embodiment; and (ii) an E-PVA having a DH of 86-99, 86-95, 86-90, 90-99.5, 95-99.5, or about 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 99.5% (±10%), where each value or range constitutes a separate and independent embodiment. Any combination of the above DP and DH is a separate and independent embodiment.

[0046] In some embodiments, the compositions and polymers of the present invention comprise: I) PVOH, which is a fully hydrolyzed grade PVOH having a degree of hydrolysis of 98% to 99% (or 100%) and a degree of polymerization of 300 to 2000, or 500 to 1700, for example, 1700; II) E-PVA, (i) DP is 300-1,500, 300-1,000, 300-900, 300-800, 300-700, 300-600, 300-500, 500-2,000, 500-1,500, 500-1,000, 500-900, 500-800, 1,000-2,000, 1,000-1,500, and or about 300, 400, 500, 600, 700, 800, 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 1,600, 1,700, 1,800, 1,900, or 2,000 (±10%), where each value or range constitutes a separate and independent embodiment; and (ii) an E-PVA having a DH of 86-99, 86-95, 86-90, 90-99.5, 95-99.5, or about 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 99.5% (±10%), where each value or range constitutes a separate and independent embodiment. Any combination of the above DP and DH is a separate and independent embodiment.

[0047] The amount of E-PVA in the composition may vary. In some embodiments, the amount of E-PVA is up to 60% by weight, based on the total weight of the composition. In some embodiments, the amount of E-PVA is at least 5% by weight, based on the total weight of the composition.

[0048] In some embodiments, the amount of E-PVA is 5-60, 5-55, 5-50, 5-45, 5-40, 5-35, 5-30, 5-25, 5-20, 5-15, 5-10, 10-60, 10-55, 10-50, 10-45, 10-40, 10-35, 10-30, 10-25, 10-20, 20-60, 20-50, 20-40, 20-30, 30-60, 30-50, 40-60, or 40-50 wt%.

[0049] In some embodiments, the amount of E-PVA in the compositions of the present invention is 5-10, 10-60, 10-55, 10-50, 10-45, 10-40, 10-35, 10-30, 10-25, or 10-20% by weight.

[0050] The "plasticizer" present in the composition of the present invention is one or more compounds used to increase the fluidity or plasticity of the polymer composition of the present invention. At least one plasticizer is selected from among materials capable of lowering the glass transition temperature and / or melting point of the polymer composition under melt extrusion. Without being bound by theory, the plasticizer used can reduce the melt viscosity, tensile strength, hardness, and density of the molten composition, and increase parameters such as elongation at break, toughness, and dielectric constant.

[0051] The at least one plasticizer used is generally compatible with PVOH, stable under hot-melt extrusion conditions, and has sufficient lubricity and stability in the final compounded product and film. The at least one plasticizer may be one or more selected from sorbitol, maltitol, mannitol, glycerol, erythritol, dipropylene glycol, triethylene glycol, tetraethylene glycol (TEG), triethanolamine (TEA), trimethylolpropane, pentaerythritol, dipentaerythritol, dibutyl sebacate (DBS), polyglyceryl-4 laurate, ditrimethylolpropane, urea, diglycerol, xylitol, acetyl tributyl citrate (ATBC), polyethylene glycol, triethyl citrate, vitamin ETPGS (D-α-tocopherol polyethylene glycol 1000 succinate), ethylene glycol, diethylene glycol, 1,2,4-butanetriol, epoxidized soybean oil, ethoxylated glycerol, etc.

[0052] In some embodiments, the at least one plasticizer may be selected from glycerol, sorbitol, propylene glycol, polyethylene glycol, and the like, and any combination thereof.

[0053] In some embodiments, the at least one plasticizer is glycerol and / or sorbitol. In some embodiments, the at least one plasticizer is glycerol.

[0054] The amount of plasticizer may vary or may be minimized. The amount of plasticizer is typically 20% by weight or less. In some cases, the minimum amount may be 1% by weight or less. In some embodiments, the amount of plasticizer may be selected to be 1-20% by weight based on the total weight of the composition.

[0055] In some embodiments, the amount of plasticizer is 1-20, 1-15, 1-10, 1-5, 1-4, 1-3, or 1-2 wt. % based on the total weight of the composition, or the amount is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, or 20 wt. %.

[0056] The weight ratio of plasticizer to PVOH used can be, for example, 2, 3, or more times the weight of PVOH compared to the weight of plasticizer. In some embodiments, the ratio of plasticizer to PVOH used can be 1:2 to 1:20 (wt / wt). In some embodiments, this ratio is 1:10, 1:15, or 1:20.

[0057] The present invention further provides the following compositions which exemplify the scope of the disclosed invention: Composition 1: PVOH grade 1; EPVA grade 1; glycerol; ratio 58:39:3 (or 60:40:3); Composition 2: PVOH as a combination of PVOH Grade 1 and PVOH Grade 2; EPVA Grade 1; glycerol; PEG; ratio (47:32:15:3:3); Composition 3: PVOH as a combination of PVOH Grade 1 and PVOH Grade 2; EPVA Grade 1; glycerol; PEG; ratio (47:31:10:10:2); Composition 4: PVOH Grade 1; EPVA Grade 1; Glycerol; Ratio 68:29:3; Composition 5: PVOH Grade 1; EPVA Grade 1; glycerol; PEG; ratio 52:43:3:2; Composition 6: PVOH Grade 2; EPVA Grade 2; Glycerol; PEG; Ratio 57:38:3:2; Composition 7: PVOH as a combination of PVOH Grade 1 and PVOH Grade 2; EPVA Grade 1; glycerol; PEG; ratio 49:21:25:3:2; Composition 8: PVOH as a combination of PVOH Grade 1 and PVOH Grade 2; EPVA Grade 1; glycerol; PEG; ratio 58:25:5:10:2; Composition 9: PVOH as a combination of PVOH Grade 1 and PVOH Grade 2; E-PVA as a combination of EPVA Grade 1 and EPVA Grade 2; glycerol; ratio 35:22:25:15:3; Composition 10: PVOH Grade 2; EPVA Grade 2; Glycerol; Ratio 49:48:3; Composition 11: PVOH as a combination of PVOH Grade 1 and PVOH Grade 2; EPVA Grade 2; glycerol; PEG; ratio 15:59:20:3:3; Composition 12: PVOH as a combination of PVOH Grade 1 and PVOH Grade 2; EPVA Grade 2; glycerol; PEG; ratio 71:18:5:5:1; Composition 13: PVOH Grade 2; EPVA Grade 1; Glycerol; PEG; Ratio 73:20:5:2; Composition 14: PVOH as a combination of PVOH Grade 1 and PVOH Grade 2; E-PVA as a combination of EPVA Grade 1 and EPVA Grade 2; glycerol; PEG; ratio 35:35:15:10:3:2.

[0058] The compositions of the present invention may or may not contain a crosslinker. Typically, the crosslinker is present in small amounts of 1% by weight or less, or 0.5% by weight or less. In some embodiments, the amount of crosslinker is 0.03-0.5% by weight.

[0059] The crosslinker can be any material capable of forming covalent or chemical bonds or chemical crosslinks between chains of PVOH, between PVOH and ethylene-polyvinyl alcohol copolymer, or between any two or more crosslinkable or polymerizable materials (PVOH, E-PVA, and / or plasticizer) present in the composition. Optionally, the crosslinker is selected from among difunctional or multifunctional materials.

[0060] Crosslinkers can be selected from polymers, copolymers, and non-polymeric materials each having functional groups capable of bonding with the OH functional groups present on the PVOH backbone. Crosslinking or bonding is typically achieved through the formation of covalent bonds. In other instances, bonding may be physical, such as intertwining of polymer chains. In some embodiments, bonding is through the formation of hydrogen and / or ionic bonds. Regardless of the type of bond, the crosslinking molecules are selected to provide bonds that result in the desired physical and mechanical profile.

[0061] The functional groups of the crosslinking compound that enable bonding with PVOH may be inherent in the compound, e.g., oligomer or polymer, or may be grafted, bonded, or added to the compound to provide crosslinking functionality. In some embodiments, the crosslinking compound includes functional groups selected from alcohol, epoxide, anhydride, carboxylic acid, amine, amide, glycidyl functionality, aldehyde functionality, ester, and the like. The crosslinking compound may also be a polymer selected from ionomers, i.e., polymers having one or more functional groups capable of forming ionic groups. In some embodiments, the ionomer is a polyacid selected from polyacrylic acid (PAA), polymethacrylic acid (PMAA), and the like.

[0062] In some embodiments, the crosslinking compound is a polymer grafted with an anhydride, such as maleic anhydride. In some embodiments, the polymer to which the maleic anhydride is grafted may be selected from polyethylene (PE), polylactic acid (PLA), polycaprolactone (PCL), polyhydroxybutyrate (PHB), polybutylene adipate-co-terephthalate (PBAT), polybutylene succinate (PBS), etc. In some embodiments, the crosslinking compound is polyethylene grafted maleic anhydride.

[0063] In some embodiments, the crosslinking compound is a polymer produced by copolymerization with an anhydride such as maleic anhydride. In some embodiments, the polymer into which maleic anhydride is introduced by copolymerization can be selected from polyethylene (PE), polylactic acid (PLA), polycaprolactone (PCL), polyhydroxybutyrate (PHB), polybutylene adipate-co-terephthalate (PBAT), polybutylene succinate (PBS), polybutylene succinic adipate (PBSA), etc. In some embodiments, the crosslinking compound is a copolymer of ethylene and maleic anhydride.

[0064] In some embodiments, the crosslinking compound is a polymer having carboxylic acid functionality, hi some embodiments, the polymer is selected from poly(ethylene-co-acrylic acid) (PE-co-AA), poly(ethylene-co-methacrylic acid) (PE-co-MAA), poly(lactide-block-acrylic acid) (PLA-block-AA), PVOH having carboxyl groups, carboxymethylcellulose (CMC), etc.

[0065] In some embodiments, the polymer is poly(ethylene-co-acrylic acid).

[0066] In some embodiments, the polymer is a glycidyl-functional polymer.

[0067] In some embodiments, at least one cross-linking compound is a copolymer.

[0068] In some embodiments, the crosslinking compound is a small molecule crosslinking compound that is not a polymer, oligomer, or copolymer. In such embodiments, the compound is typically selected from among aldehyde compounds, carboxylic acid compounds, amine compounds, halogen-substituted compounds, and other compounds that are reactive in the presence of or toward PVOH.

[0069] In some embodiments, the aldehyde compound may be selected from among monoaldehydes and dialdehydes, hi some embodiments, the aldehyde is selected from formaldehyde, glutaraldehyde, glyoxal, malondialdehyde, succinaldehyde, phthalaldehyde, and the like.

[0070] In some embodiments, the carboxylic acid compound is selected from monocarboxylic acids, dicarboxylic acids, tricarboxylic acids, and higher homologs (having four or more carboxylic acid groups). These carboxylic acids can be selected based on the number of carboxylate or basic groups they can form. Similarly, these compounds can be selected from monobasic acids, dibasic acids, tribasic acids, and higher homologs (having four or more basic acids). In some embodiments, the carboxylic acid compound is selected from succinic acid, citric acid, boric acid, humic acid, phthalic acid, terephthalic acid, malic acid, sulfosuccinic acid, isophthalic acid, aconitic acid, fumaric acid, tartaric acid, 1,2,3,4-butanetetracarboxylic acid (BTCA), etc.

[0071] In some embodiments, the crosslinking agent is selected from succinic acid, 1,2,3,4-butanetetracarboxylic acid (BTCA), ethylene maleic anhydride copolymer, tartaric acid, and the like.

[0072] The compositions of the present invention may contain one or more additional agents or additives selected to impart mechanical or chemical properties to the polymeric material formed therefrom, which may be selected from plasticizers, softeners, bioplastics, polysaccharides, aliphatic polyesters and copolymers thereof, aromatic polyesters and copolymers thereof, cellulosic materials, inorganic additives, fillers, reinforcing agents, low molecular weight additives (molecular weight 3,000 Da or less), processing aids, slip agents, light stabilizers, ultraviolet absorbers, flame retardants, antibacterial agents, antiviral agents, foaming agents, nucleating agents, antioxidants, antiblocking agents, antistatic agents, deodorizing agents, and the like.

[0073] The bioplastics used in accordance with the present invention are polymers that are distinct from the other polymeric components used in the compositions of the present invention, all of which are substantially bioplastics. Bioplastics may be represented by natural polymers produced or derived from natural sources, such as cells of living organisms or plants. Such polymers may be entirely natural polymers or partially synthetic, i.e., naturally derived, with the structure of natural polymers chemically modified. Bioplastics used in accordance with the present invention may also be represented by biodegradable or compostable polymers that are partially or entirely petrochemically derived.

[0074] In some embodiments, the bioplastic is selected from polypeptides and polysaccharides. In some embodiments, the bioplastic is selected from aliphatic or aromatic polyesters, copolyesters, or polyesteramides. In some embodiments, the bioplastic is selected from poly(ethylene glycol) (PEG), including high molecular weight poly(ethylene oxide) (PEO), polycaprolactone (PCL), polylactic acid (PLA), cellulose and cellulose derivatives, starch, thermoplastic starch (TPS), chitosan, polyhydroxyalkanoates (PHAs) such as polyhydroxybutyrate (PHB), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), and polybutylene succinate adipate (PBSA).

[0075] Cellulose derivatives are crystalline derivatives or other amorphous forms of such materials. Non-limiting examples include nanocrystalline cellulose (NCC), microfibril cellulose, microcrystalline cellulose (MCC), bacterial cellulose (BC), hydroxypropylmethylcellulose (HPMC), hydroxypropylcellulose (HPC), hydroxyethylcellulose (HEC), carboxymethylcellulose (CMC), etc.

[0076] In some embodiments, the additive is a moisture absorbent, optionally selected from CaO, CaCl, LiCl, NaCl, CaI, MgCl, TiO, CaCO, alumina silicate fillers, SiO, etc. In some embodiments, the additive is CaO.

[0077] In some embodiments, the additive is an inorganic salt containing a metal element or a non-metal element. In some embodiments, the inorganic salt is an inorganic salt of a metal selected from alkali metals and alkaline metals. In some embodiments, the inorganic salt is a salt of a transition metal.

[0078] Non-limiting examples of inorganic salts include halide salts of metals selected from Li, K, Ca, Na, Mg, Mn, Zn, and the like.

[0079] The inorganic salt can be a halide salt (the halide atom is the anion of the metal cation). In some embodiments, the inorganic salt can be selected from LiCl, NaCl, CaCl, CaI, and MgCl. In some embodiments, the inorganic salt is CaCl. In some embodiments, the salt is a calcium salt, such as CaCl, CaI, etc.

[0080] The present invention further provides the following compositions for producing polymeric films or products according to the invention: 1) 57-58.5 wt% PVOH, 35-40 wt% ethylene-polyvinyl alcohol copolymer, and 1.5-3 wt% glycerol; or 2) 75-85 wt% PVOH, 10-20 wt% ethylene-polyvinyl alcohol copolymer, 3 wt% glycerol, 2% polyethylene glycol, 0.2-0.25% BTCA, 0.04-0.08% sodium propionate, and 0.4-0.5% calcium stearate (CaSt).

[0081] The compositions of the present invention can be converted into stock forms or concentrates containing preselected ingredients in amounts and ratios appropriate for producing a particular polymer product. The compositions of the present invention can be converted into compounded forms, such as pellets or other solid particulate forms (e.g., beads), which can be used directly in the production of final polymer products, such as polymer films or sheets. Pellets or granular solid forms can be produced by compounding the compositions of the present invention under preselected conditions. Through the compounding process, the composition or resin is converted into a form with more effective, efficient, and uniform properties, making it ready for further processing, for example, through molding or extrusion processes. Pellets can be of any shape, but are typically small, cylindrical, or cylindrical bodies with flat surfaces, such as cubes or rectangular prisms. Pellets are formed from a homogeneous mixture of the compositions of the present invention that has been processed as disclosed herein.

[0082] Thus, the present invention further provides pellets or solid materials (eg, beads) formed from or comprising the compositions of the present invention. In some embodiments, pellets obtained by compounding the compositions of the present invention comprise crosslinked PVOH, where the crosslinks include crosslinks between PVOH chains, between PVOH and a plasticizer (e.g., glycerol), between PVOH, a plasticizer and an ethylene-polyvinyl alcohol copolymer, between a plasticizer and an ethylene-polyvinyl alcohol copolymer, or between other components present in the composition.

[0083] In some embodiments, the compounding is carried out by heat treating the composition of the present invention to - PVOH and ethylene-polyvinyl alcohol copolymer blends; - plasticization of PVOH by forming hydrogen bonds between PVOH and plasticizers (e.g. glycerol); - Crosslinking between the PVOH and / or other ingredients mentioned above; and / or -Volatilization of water and other low-boiling components.

[0084] The present invention further provides a process for producing pellets from the compositions of the present invention, which process comprises compounding the composition under conditions selected to convert the composition into a solid, specified material.

[0085] In some embodiments, the conditions include converting the composition to a molten state and causing evaporation or partial evaporation of volatile materials. Thus, compounding can be carried out by extrusion, for example in an extruder such as a twin-screw extruder.

[0086] In some embodiments, the twin screw extruder is a co-rotating or counter-rotating extruder. In some embodiments, compounding involves the use of a kneader and / or mixer.

[0087] In some embodiments, compounding can be accomplished by heating the composition and then subjecting the melt to a mixing process. In some embodiments, compounding can be carried out in a twin-screw extruder equipped with a suitable devolatilizing system to remove unreacted monomers, solvent, water, dissolved gases, or other undesirable volatile materials from the polymer melt.

[0088] The pellets or solid particulate material formed by incorporating the composition of the present invention can be used to make polymeric objects (e.g., polymeric films or sheets) by further processing the pellets or solid particulate material, for example, by molding or extrusion. Thus, in another aspect of the present invention, there is provided the use of the composition of the present invention to make polymeric products such as polymeric films or polymeric sheets.

[0089] The present invention further provides a method for producing a polymeric article, such as a film or sheet, which method comprises converting a formulation of the composition of the present invention into a polymeric article, for example by molding or extrusion.

[0090] In some embodiments, the method comprises extruding a blend of the composition of the present invention.

[0091] In some embodiments, the formulation of the composition is in pelletized form.

[0092] In some embodiments, the pelletized form is obtained by compounding as disclosed herein. In some embodiments, compounding is carried out by converting the composition to a molten state and then causing evaporation or partial evaporation of volatile materials. Compounding can be carried out by extrusion, for example, in an extruder such as a twin-screw extruder. In some embodiments, the twin-screw extruder is a co-rotating or counter-rotating extruder. In some embodiments, compounding involves the use of a kneader and / or mixer. In some embodiments, compounding can be achieved by heating the composition and then subjecting the melt to a mixing process. In some embodiments, compounding can be carried out in a twin-screw extruder equipped with a suitable devolatilizing system to remove unreacted monomers, solvents, water, dissolved gases, or other undesirable volatile materials from the polymer melt.

[0093] In some embodiments, a method for producing a polymeric product, such as a film or sheet, includes incorporating a composition of the present invention into a pellet form and converting the pellet form into a polymeric product, for example, by molding or extrusion.

[0094] In some embodiments, the method comprises: - providing a composition according to the invention; - compounding said composition into pellets; - converting said pellets into a polymer product.

[0095] Conversion of the compounded form, e.g., pellets, into a polymer product can be accomplished by molding or extrusion, including injection molding. Depending on the size and shape of the polymer product, appropriate techniques can be utilized. If the product is a film or sheet, the conversion can include blown film extrusion or cast film extrusion.

[0096] In some embodiments, film or sheet is produced by blown film extrusion. In this process, the compounded material of the present invention, often in pellet or bead form, is placed in a hopper and fed into a heated barrel with a screw. The pellets are gradually heated to melt the polymer, and the molten material is extruded through a die. Various dies can be used, including an annular or ring die. The molten polymer enters the die head, and air is injected through a central hole in the die, causing the polymer to radially expand into a thin tube many times the extrusion diameter. The thickness and width of the film can be tailored to the desired film profile. After extrusion, the hot tubular film is cooled and pulled, such as by nip rollers. As the film cools, it flattens and is transported for further processing.

[0097] A variety of products can be made using the blown film extrusion process, from simple monolayer films to complex multi-layer structures such as those used in food packaging.

[0098] In some embodiments, the film or sheet is produced by a cast film extrusion process, whereby, unlike a blown extrusion process, the molten polymer is fed through a flat die system to adopt the final flat film shape. In the case of coextrusion, the die system includes a die and a feedblock, while in the case of monolayer extrusion, a flat die can be used.

[0099] The orientation of the polymeric film or sheet can be determined or altered by tenter frame, double bubble, or machine direction orientation. The resulting film can be further modified to form a metallized film by methods such as roll slitting, coating, printing, or physical vapor deposition. The film can also be corona or plasma treated, and optionally coated with a release agent.

[0100] In some embodiments, the film can be thermoformed, stretched, compression molded, and / or laminated.

[0101] In some embodiments, the extruded film is oriented while being stretched.

[0102] The oriented or shrinkable film of the present invention can be of any thickness depending on the desired end use. For applications such as labels, where the film and / or shrinkable film is printed with ink and adhered to a substrate such as paper, the film thickness may be smaller than that of a shrinkable protective film. In some embodiments, the film thickness is 10 microns to 500 microns, 25 microns to 500 microns, 50 microns to 500 microns, 100 microns to 500 microns, 150 microns to 500 microns, 200 microns to 500 microns, 250 microns to 500 microns, 300 microns to 500 microns, 350 microns to 500 microns, 400 microns to 500 microns, or 450 microns to 500 microns.

[0103] In some embodiments, films may be provided in thicknesses of 10 microns to 100 microns, 10 microns to 90 microns, 10 microns to 80 microns, 10 microns to 70 microns, 10 microns to 60 microns, 10 microns to 50 microns, 10 microns to 40 microns, 10 microns to 30 microns, 10 microns to 20 microns, 20 microns to 100 microns, 30 microns to 100 microns, 40 microns to 100 microns, 50 microns to 100 microns, 60 microns to 100 microns, 70 microns to 100 microns, 80 microns to 100 microns, 90 microns to 100 microns, 30 microns to 90 microns, 30 microns to 80 microns, 30 microns to 70 microns, 30 microns to 60 microns, or 30 microns to 50 microns.

[0104] In some embodiments, the film may be provided in a thickness of 10 microns to 200 microns, 10 microns to 300 microns, or 10 microns to 400 microns.

[0105] Multilayer films can also be produced by blown film coextrusion, which combines two or more molten polymeric materials.

[0106] In some embodiments, films formed according to the present invention are multilayer films containing two or more layers of the same or different composition. The multilayer film may be a coextruded film, e.g., at least one layer is a composition according to the present invention or a composition produced according to the present invention, and at least one other layer is a polymeric or non-polymeric film of a different composition. Alternatively, the multilayer film may be a coextruded blown film having at least three layers, each of which may comprise at least one layer of a polymeric or non-polymeric material and two or more layers that differ, for example, in ethylene content, plasticizer used, or PVOH grade used, each independently selected from the compositions disclosed herein.

[0107] According to some embodiments, the multilayer film comprises 2-20 layers, at least one of which is formed from a blended composition according to the present invention. The multilayers may be in the form of AB, ABA, BAB, AABB, etc., where at least one of the A or B layers is a multilayer film according to the present invention.

[0108] Multilayer films can be produced by conventional methods, such as coextrusion. In some cases, multilayer films can be produced by coextrusion from two or more extruders, each designed to extrude the extrusion composition that forms one of the layers.

[0109] The polymeric films of the present invention can be used in a wide variety of applications, including packaging, plastic bags, labels, shrink labels, electrical processing, photographic film, and film stock.

[0110] As used herein with respect to the films of the present invention, the term "film" includes both films and sheets and has its generally accepted meaning in the art. This term includes monolayer and multilayer films.

[0111] The films of the present invention have been found to exhibit superior properties as disclosed compared to similar films not formed from PVOH and E-PVA. -Excellent water biodegradability and improved water resistance over time; -Surprisingly low oxygen transmission rate (OTR), demonstrating excellent oxygen barrier properties -Improved water resistance - Improved Coefficient of Friction (CoF): According to the CoF test method described below, the CoF value obtained with the present invention is <0.35, and is stable especially at EPVA usage levels >20%. - Improved tackiness: According to the tackiness test method described below, the tackiness level obtained with the present invention is <0.25 N / cm, and is stable especially at EPVA use levels >20%. [Brief explanation of the drawings]

[0112] In order that the subject matter disclosed herein may be better understood, and to illustrate how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: [Figure 1] Figure 1 is an exemplary analysis of the absolute biodegradation rate of a reference composition (based on O2 consumption). Improvements are calculated based on the plateau area of ​​the graph. [Figure 2] Figure 2 shows that the OTR values, in units of cm3 / m2*day, for 50 micron films are reduced compared to films formed with compositions that do not contain E-PVA. [Figure 3] FIG. 3 is a spider chart illustrating the unique properties of the compositions of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0113] Preparation of the Compositions of the Invention Dry partially hydrolyzed PVOH with an average degree of polymerization of 800-1400 (see below), or a combination of various grades of PVOH (e.g., partially hydrolyzed PVOH with a DP of 800 and partially hydrolyzed PVOH with a DP of 1400) was mixed and a plasticizer (e.g., glycerol) was added. After heating the mixture, ethylene-polyvinyl alcohol copolymer was added and mixed for approximately 15 minutes to obtain a premix. Then, additives (e.g., crosslinking agent, slip agent) were added to the premix.

[0114] The twin screw extruder was heated with a flat temperature profile to around 205° C. At the indicated temperature, the premix was added to the feeder and the process was run at 350 RPM, varying depending on the stability of the process.

[0115] Pellets are obtained and later used in the film blowing process.

[0116] Examples of specific material combinations that can be used are shown in Table 1 below.

[0117] Film blowing: The pellets were placed in a feeder and the process was carried out at a temperature of 200° C. (all zones). Once the formed balloons were stable and the film had the required quality, it was rolled or wound for collection.

[0118] Films made from plasticized blends of polyvinyl alcohol (PVOH) and ethylene-polyvinyl alcohol copolymer (PVOH) exhibited superior surface properties (reduced coefficient of friction (CoF) and adhesion), water resistance, and biodegradability compared to films without ethylene-polyvinyl alcohol copolymer. By using a crosslinker, the amount of ethylene-polyvinyl alcohol copolymer can be significantly reduced without compromising water resistance or surface properties.

[0119] The compositions of the present invention and films made therefrom were tested and their properties measured. Table 1 shows the compositions and the properties measured. TIFF2026500554000001.tif246170TIFF2026500554000002.tif246170

[0120] Composition 7 in Table 1 was prepared by mixing PVOH, E-PVA, and plasticizer in a high-speed mixer. Two grades of PVA were added to the mixer in the desired ratio (45 / 30), followed by the addition of plasticizer (3 wt% glycerol, 3 wt% PEG). The mixing process was initiated, and once the premix began to form a powder, the E-PVA was added. The mixing process continued until the premix began to heat up and the mixture became a homogeneous, dry powder. The final premix was then placed in the compounding unit feeder, where the compounding process began. The materials were heated and converted to a melt, then cooled into strands and chopped into pellets. The pellets were then converted to film via blown film extrusion.

[0121] All compositions and products of the present invention were prepared in a similar manner.

[0122] The films were subjected to all surface property tests as described below.

[0123] Biodegradability of cryogenically ground pellets was tested by measuring CO2 production in samples placed in an aqueous solution inoculated with undefined, unfiltered sludge from a local wastewater treatment plant using a respirometer (Echo Instruments, Model E12 / 1.4) according to ISO 14851 and ISO 14852.

[0124] Deterioration by water (disintegration and dissolution) Test protocol: 50 micron film (3 * 3cm 2 ) was placed in a container containing water (250 ml) and incubated at 30°C on an orbital shaker, and the appearance of disintegration and dissolution was evaluated according to the following prescribed numerical table.

[0125] The time for film disintegration and / or dissolution, when particles greater than 2 mm were visually evident, was classified as follows: Very fast: just a few minutes Fast: Less than an hour Medium: Less than 24 hours Slow: 2-4 days Very slow: 5 days or more

[0126] Coefficient of Friction (CoF): ASTM D1894-14 Test protocol: Using a standard mechanical tensile testing device, a weight was dragged across the surface at a constant speed of 150 mm / min. Both the weight and the surface were covered with the tested film. The weight was typically 200 grams and the drag distance was typically 150 mm. CoF is the frictional force acting on an object divided by the normal force acting on the same object and is dimensionless. The results are as follows: Low CoF: less than 0.25 Medium CoF:0.25~0.35 High CoF: over 0.35

[0127] Stickiness: Test protocol: After exposure to the specified humidity and temperature conditions, the two films were pressed together without heating. The force required to peel the two films was then measured. This force correlates with the adhesion level as follows:

[0128] Testing Protocol: The films were first placed in a humidity chamber at 38°C and 75% RH for 1 hour. They were then removed from the chamber and allowed to rest at room temperature for 1 minute before being laminated in an Excelam II-3550 benchtop roll laminator (no heat was applied, only constant pressure and speed). They were then allowed to rest under ambient conditions for an additional 30 minutes before being tested for peel force. Peel force was measured using a standard mechanical tensile tester. The results are as follows: Very low tack (no tack) - film will not stick after lamination. Low adhesion: less than 0.1N / cm Medium tack: 0.1~0.25N / cm High adhesion: over 0.25N / cm

[0129] Biodegradable: Biodegradability in water and sludge environments was tested according to ISO14851 or ISO14852. The biodegradability in the table above was defined as 90% compared to microcrystalline cellulose (determined as carbon in evolved CO2 relative to calculated total organic carbon (TOC)). The biodegradability assessment is as follows: Very fast: 14-21 days Fast: 21-56 days Medium: 56 to 120 days Slow: 120~180 days

[0130] Water resistance (time until deformation): Water resistance was evaluated by dropping three drops of water (each drop was approximately 100-110 μl) onto a 50-micron film placed horizontally, and measuring the time it took for the film to begin to deform. The waterproofing grades are as follows: Very low: 1 to 15 seconds Low: 15~30 seconds Medium: 30~60 seconds High: 1~15 minutes Very high: 15 minutes or more

[0131] Processability: TIFF2026500554000003.tif43170

[0132] The workability classification is as follows: -Good: Stable blending and blowing process / pressure and torque. - Medium: Some bubbles in the strands during compounding. The process is not very stable (torque overload / high pressure etc.). - Poor: Formulations could not be produced due to poor melt quality, torque overload, or excessive bubble count. No film was produced from these formulations.

[0133] Barrier to oxygen and CO2 permeation Gas barrier properties are defined by the oxygen transmission rate (OTR), which is the rate at which oxygen permeates a film of a given thickness in cm 3 / m 2* It is expressed in units of days. The lower the OTR value at a given thickness, the higher the barrier properties. The gas permeability of carbon dioxide is generally 3 to 5 times that of oxygen for a given film and thickness.

[0134] For water-sensitive materials, oxygen barrier properties are usually dependent on the % relative humidity. It was found that as the EVPA concentration increased, the humidity dependence of OTR decreased, and the OTR value at a specific RH value was lower compared to the composition without EVPA (Figure 2).

[0135] As the presented results demonstrate, polymers formed from the compositions of the present invention exhibit low tack, low CoF, high water resistance (longer time to deformation), and high biodegradability, which are significantly improved in all E-PVA containing formulations (compared to the reference composition without E-PVA, Composition 12).

[0136] The spider chart shown in Figure 3 demonstrates that a wide range of desirable properties can be achieved using the E-PVA containing formulations described herein. EVOH, widely used as a barrier material, has excellent extrudability and barrier properties, but is insoluble, non-biodegradable, and relatively expensive. In contrast to EVOH, extrudable PVOH has poor barrier and water resistance properties, but is affordable and generally biodegradable. Formulations containing E-PVA combine the advantages of both EVOH and extrudable PVOH. This composition exhibits good extrudability, excellent barrier properties, affordability, water resistance, and biodegradability, as shown in the spider chart.

Claims

1. A composition comprising polyvinyl alcohol (PVOH), an ethylene-polyvinyl alcohol copolymer, a plasticizer, and optionally a crosslinker.

2. 10. The composition of claim 1 for use in producing a water-biodegradable and water-resistant thermoplastic polymer.

3. 3. The composition of claim 1 or 2, in the form of a mixture of PVOH, E-PVA and a plasticizer.

4. 3. The composition of claim 1 or 2, in the form of a crosslinked polymer of PVOH and E-PVA formed in the presence of a crosslinking agent, said composition further comprising a plasticizer.

5. 5. The composition of claim 1, in the form of a formulation.

6. 6. The composition of claim 1, in the form of pellets, or in the form of a polymer sheet or film.

7. The composition of any one of claims 1 to 6, wherein the PVOH is uncrosslinked.

8. 8. The composition of any one of claims 1 to 7, wherein the PVOH is a single grade or a combination of grades of PVOH.

9. The composition of claim 8, wherein the PVOH is selected from hydrolyzed PVOH having a degree of hydrolysis ranging from 86 to 99%.

10. The composition of claim 8, wherein the PVOH is selected from PVOH having a degree of polymerization ranging from 500 to 3,000.

11. The composition according to claim 8, wherein the PVOH is a partially hydrolyzed PVOH having a degree of polymerization of 300 to 2,000.

12. 9. The composition of claim 8, wherein the PVOH has a degree of polymerization of 800 to 1400, or a molecular weight of 30 KDa to 70 KDa, or a molecular weight of 35 KDa to 62 KDa.

13. The PVOH is (i) Grade 1: Partially hydrolyzed grade with a degree of hydrolysis of 86-90% and a degree of polymerization (DP) of 300-2000 or 500-1400; (ii) Grade 2: Medium hydrolysis grade with a degree of hydrolysis of 91-97%, and (iii) Grade 3: fully hydrolyzed grade with a degree of hydrolysis of 98% to 99% (or 100%) and a degree of polymerization of 300 to 2000, or 500 to 1700; 13. The composition of claim 1, wherein the composition is one or more of:

14. The composition of any one of claims 1 to 12, wherein the PVOH is provided in an amount of 40 to 90 wt% (based on the total weight of the composition).

15. The composition according to any one of claims 1 to 14, wherein the ethylene content of the ethylene-polyvinyl alcohol copolymer (E-PVA) is 15 mol% or less.

16. The composition of claim 15, wherein the ethylene content of the E-PVA is 1 to 15 mol%.

17. The E-PVA is (1) Grade 1: Degree of polymerization (DP) 300-800; (2) Grade 2: degree of polymerization (DP) of 800 to 1500; and (3) Grade 3: Degree of polymerization (DP) is 1500-2000; 17. The composition of claim 1, wherein the composition is one or more of:

18. The composition according to any one of claims 1 to 16, wherein the degree of polymerization of the E-PVA is 300 to 2,000.

19. 19. The composition of any one of claims 1 to 18, wherein the PVOH is Grade 1 as defined in claim 13 and the E-PVA is Grade 1, 2, and / or 3 as defined in claim 17.

20. 19. The composition of any one of claims 1 to 18, wherein the PVOH is Grade 2 as defined in claim 13 and the E-PVA is Grade 1, 2, and / or 3 as defined in claim 17.

21. 19. The composition of any one of claims 1 to 18, wherein the PVOH is Grade 3 as defined in claim 13 and the E-PVA is Grade 1, 2, and / or 3 as defined in claim 17.

22. 19. The composition of any one of claims 1 to 18, wherein the PVOH is one or more of Grade 1, 2, or 3 as defined in claim 13, and the E-PVA is Grade 1 as defined in claim 17.

23. 19. The composition of any one of claims 1 to 18, wherein the PVOH is one or more of Grade 1, 2, or 3 as defined in claim 13, and the E-PVA is Grade 2 as defined in claim 17.

24. 19. The composition of any one of claims 1 to 18, wherein the PVOH is one or more of Grade 1, 2, or 3 as defined in claim 13, and the E-PVA is Grade 3 as defined in claim 17.

25. 10. The composition of claim 1 , the PVOH (i) Partially hydrolyzed grades with a degree of hydrolysis of 86-90% and a degree of polymerization (DP) of 300-2000 or 500-1400; (ii) Medium hydrolysis grades with a degree of hydrolysis of 91-97%, and (iii) one or more of the following: a fully hydrolyzed grade having a degree of hydrolysis of 98% to 99% (or 100%) and a degree of polymerization of 300 to 2000, or 500 to 1700; - the E-PVA is (i) E-PVA having a DP of 300-1,500, 300-1,000, 300-900, 300-800, 300-700, 300-600, 300-500, 500-2,000, 500-1,500, 500-1,000, 500-900, 500-800, 1,000-2,000, 1,000-1,500, or about 300, 400, 500, 600, 700, 800, 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 1,600, 1,700, 1,800, 1,900, or 2,000 (±10%); (ii) E-PVA having a DH of 86-99, 86-95, 86-90, 90-99.5, 95-99.5, or about 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 99.5% (±10%).

26. 10. The composition of claim 1 , the PVOH is a partially hydrolyzed grade having a degree of hydrolysis of 86-90% and a degree of polymerization (DP) of 300-2000, or 500-1400, e.g., 500, 800, or 1400; - the E-PVA is (i) DP is 300 to 1,500, 300 to 1,000, 300 to 900, 300 to 800, 300 to 700, 300 to 600, 300 to 500, 500 to 2,000, 500 to 1,500, 500 to 1,000, 500 to 900, 500 to 800, 1,000 to 2,000, 1,000 00 to 1,500, or an E-PVA having a DP of about 300, 400, 500, 600, 700, 800, 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 1,600, 1,700, 1,800, 1,900, or 2,000 (±10%); (ii) E-PVA having a DH of 86-99, 86-95, 86-90, 90-99.5, 95-99.5, or about 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 99.5% (±10%).

27. 10. The composition of claim 1 , - the PVOH is a medium hydrolysis grade having a degree of hydrolysis of 91-97%; - the E-PVA is (i) E-PVA having a DP of 300-1,500, 300-1,000, 300-900, 300-800, 300-700, 300-600, 300-500, 500-2,000, 500-1,500, 500-1,000, 500-900, 500-800, 1,000-2,000, 1,000-1,500, or about 300, 400, 500, 600, 700, 800, 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 1,600, 1,700, 1,800, 1,900, or 2,000 (±10%); (ii) E-PVA having a DH of 86-99, 86-95, 86-90, 90-99.5, 95-99.5, or about 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 99.5% (±10%).

28. 10. The composition of claim 1 , the PVOH is a fully hydrolyzed grade having a degree of hydrolysis of 98% to 99% (or 100%) and a degree of polymerization of 300 to 2000, or 500 to 1700; - the E-PVA is (i) E-PVA having a DP of 300-1,500, 300-1,000, 300-900, 300-800, 300-700, 300-600, 300-500, 500-2,000, 500-1,500, 500-1,000, 500-900, 500-800, 1,000-2,000, 1,000-1,500, or about 300, 400, 500, 600, 700, 800, 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 1,600, 1,700, 1,800, 1,900, or 2,000 (±10%); (ii) E-PVA having a DH of 86-99, 86-95, 86-90, 90-99.5, 95-99.5, or about 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 99.5% (±10%).

29. 29. The composition according to any one of claims 1 to 28, wherein the amount of E-PVA in the composition is from 5 to 60% by weight relative to the total weight of the composition.

30. 30. The composition according to any one of claims 1 to 29, wherein the plasticizer is selected from among materials capable of lowering the glass transition temperature and / or melting point of the composition under melt extrusion.

31. 31. The composition of claim 1 or 30, wherein the plasticizer is selected from sorbitol, maltitol, mannitol, glycerol, erythritol, dipropylene glycol, triethylene glycol, tetraethylene glycol (TEG), triethanolamine (TEA), trimethylolpropane, pentaerythritol, dipentaerythritol, dibutyl sebacate (DBS), polyglyceryl-4 laurate, ditrimethylolpropane, urea, diglycerol, xylitol, acetyl tributyl citrate (ATBC), polyethylene glycol, triethyl citrate, Vitamin E TPGS (D-alpha-tocopherol polyethylene glycol 1000 succinate), ethylene glycol, diethylene glycol, 1,2,4-butanetriol, epoxidized soybean oil, and ethoxylated glycerol.

32. 32. The composition of any one of claims 1 to 31, wherein the plasticizer is glycerol, sorbitol, propylene glycol, polyethylene glycol, or a combination thereof.

33. 33. The composition of any one of claims 1 to 32, wherein the plasticizer is provided in an amount of 1 to 20% by weight, based on the total weight of the composition.

34. 34. A pelletized solid composition comprising or formed from the composition of any one of claims 1 to 33.

35. 35. The solid composition of claim 34, formed by formulating the composition in the presence of a crosslinking agent to create one or more of crosslinks between PVOH chains, crosslinks between PVOH and plasticizer, crosslinks between PVOH, plasticizer and ethylene-polyvinyl alcohol copolymer, or crosslinks between plasticizer and ethylene-polyvinyl alcohol copolymer.

36. 36. A solid composition according to claim 34 or 35, wherein the blending is carried out by heat treating the composition to - a blend of PVOH and ethylene-polyvinyl alcohol copolymer, - plasticization of the PVOH, which creates hydrogen bonds between the PVOH and the plasticizer; - cross-linking, and / or - evaporation of water and other low boiling point components.

37. A film comprising the composition of any one of claims 1 to 33.

38. 38. The film of claim 37, wherein the composition comprises a mixture of PVOH, E-PVA, a plasticizer, and optionally at least one additive.

39. 38. The film of claim 37, wherein the composition comprises a crosslinked product of PVOH and E-PVA, or PVOH, E-PVA, and a plasticizer.

40. 40. The film of any one of claims 37 to 39, having at least 15% improved biodegradability, when measured according to ISO 14851 or ISO 14852, compared to the biodegradability of a PVOH-based product without E-PVA measured under the same conditions.

41. 41. The film of any one of claims 37 to 40, wherein the water resistance of the film is measured as the time it takes for the film to deform after contacting the film with about 300 μl of water, and the film takes 15 minutes or more to deform.

42. The oxygen transmission rate (OTR) measured at a relative humidity of 50% is 6 cm ３ / m ２＊ day ~ 0.9 cm ３ / m ２＊ 41. The film of any one of claims 37 to 40, wherein the film is day.

43. A multi-film structure comprising at least one film according to any one of claims 37 to 42.

44. 34. A method for producing a polymeric film or sheet, comprising converting a formulated form of the composition of any one of claims 1 to 33 into a polymeric film or sheet by molding or extrusion.

45. 45. The method of claim 44, wherein the method comprises extruding a compounded form of the composition.

46. 46. ​​The method of claim 45, wherein the compounded form is a pelletized form.

47. The method comprises: - providing said composition; - compounding said composition into pellets; - forming the pellets into a film or sheet by blown film extrusion.

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