Polymer blend composition

Abstract

To provide polymer blend compositions with improved processability and barrier properties, as well as polymer pellets and / or polymer films with improved barrier properties. [Solution] The polymer blend composition according to the exemplary embodiment comprises an ethylene vinyl alcohol-based polymer and an ethylene (meth)acrylic acid-based polymer having a (meth)acrylic acid content of 1% or more and less than 10% by weight. A polymer blend composition with improved processability and barrier properties can be provided. Furthermore, polymer pellets and / or polymer films with improved barrier properties can be provided.

Description

[Technical Field]

[0001] This disclosure relates to polymer blend compositions, and more particularly to polymer blend compositions comprising copolymers. [Background technology]

[0002] In recent years, barriers using polymer materials have been applied in various fields. To satisfy the physical properties required in each technological field, barriers using various types of polymers such as polyamide (PA), polyethylene terephthalate (PET), and polyvinyl alcohol (PVA) are being used.

[0003] Ethylene vinyl alcohol copolymer (EVOH) can be used as a barrier material due to its gas barrier properties and transparency. However, EVOH has poor processability and stretchability, which can lead to damage during processing and prevent the gas barrier properties from being achieved. Furthermore, EVOH has low thermal stability, making it difficult to ensure barrier uniformity, such as the formation of fish-eye patterns.

[0004] To address the shortcomings of EVOH, research is underway on polymer blends, which are mixtures of two or more polymers. Polymer blends are classified according to their mixing level into three categories: compatible polymer blends, which are mixed at the molecular level; incompatible polymer blends, which are mixed while maintaining each phase; and partially compatible polymer blends, which possess both compatible and incompatible properties.

[0005] Depending on the properties of the polymer, the physical properties may deteriorate or phase separation may occur during the mixing process. For example, due to the polarity of EVOH, phase separation may occur during the mixing process with non-polar polymers (e.g., polyethylene (PE)). [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The object of this disclosure is to provide polymer blend compositions with improved processability.

[0007] Another object of this disclosure is to provide polymer pellets with improved processability and stability.

[0008] Another object of this disclosure is to provide polymer films with improved processability and stability. [Means for solving the problem]

[0009] The polymer blend composition according to the exemplary embodiment comprises an ethylene vinyl alcohol-based polymer and an ethylene (meth)acrylic acid-based polymer having a (meth)acrylic acid content of 1% or more and less than 10% by weight.

[0010] According to exemplary embodiments, the content of the (meth)acrylic acid in the ethylene (meth)acrylic acid polymer may be 5% by weight or more and less than 10% by weight.

[0011] According to exemplary embodiments, the difference in melt index between the ethylene vinyl alcohol-based polymer and the ethylene (meth)acrylic acid-based polymer may be 10 g / 10 min or less.

[0012] According to exemplary embodiments, the melt index of the ethylene (meth)acrylic acid polymer may be 0.1 g / 10 min to 20 g / 10 min.

[0013] According to exemplary embodiments, the melt index of the ethylene vinyl alcohol-based polymer may be 0.1 g / 10 min to 10 g / 10 min.

[0014] According to exemplary embodiments, the molecular weight of the ethylene (meth)acrylic acid-based polymer may be 50,000 g / mol to 150,000 g / mol.

[0015] According to an exemplary embodiment, the content of the ethylene (meth)acrylic acid-based polymer may be 5% by weight or more and less than 40% by weight based on the total weight of the polymer blend composition.

[0016] According to an exemplary embodiment, the polymer blend composition may further include an additive containing a basic inorganic compound.

[0017] According to an exemplary embodiment, the content of the additive may be 0.01% by weight or more and less than 3.0% by weight based on the total weight of the ethylene vinyl alcohol-based polymer and the ethylene (meth)acrylic acid-based polymer.

[0018] According to an exemplary embodiment, the polymer blend composition may further include a compatibilizer containing one or more of a polyolefin-based polymer, a (meth)acrylate-based polymer, a polymer grafted with maleic anhydride, and maleic anhydride.

[0019] According to an exemplary embodiment, the content of the compatibilizer may be from 0.1% by weight to less than 10% by weight based on the total weight of the ethylene vinyl alcohol-based polymer and the ethylene (meth)acrylic acid-based polymer.

[0020] According to an exemplary embodiment, the content of ethylene in the ethylene vinyl alcohol-based polymer may be 15 mol% to 50 mol%.

[0021] The polymer pellets according to an exemplary embodiment may include the polymer blend composition according to the above-described embodiment.

[0022] The polymer film according to an exemplary embodiment may include the polymer blend composition according to the above-described embodiment. [[ID=3P]]

Advantages of the Invention

[0023] The polymer blend composition according to the present disclosure can include an ethylene vinyl alcohol-based polymer and an ethylene (meth)acrylic acid-based polymer having a (meth)acrylic acid content corresponding to a predetermined range. Thereby, the polymer blend composition can have improved processability. The barrier formed by the polymer blend composition can have improved stability.

[0024] According to an exemplary embodiment, the difference in melt index between the ethylene vinyl alcohol-based polymer and the ethylene (meth)acrylic acid-based polymer can correspond to a predetermined range. Thereby, the polymers can be more uniformly mixed and the processability can be improved.

Mode for Carrying Out the Invention

[0025] Embodiments of the present disclosure provide a polymer blend composition including an ethylene vinyl alcohol (hereinafter sometimes abbreviated as "EVOH-based polymer")-based polymer and an ethylene (meth)acrylic acid (hereinafter sometimes abbreviated as "EA-based polymer")-based polymer. Further, embodiments of the present disclosure provide polymer pellets and polymer films including the polymer blend composition.

[0026] In the present specification, "X-based compound" or "X-based polymer" can refer to a compound or polymer having an X structure. For example, an EVOH-based polymer can refer to a polymer including an ethylene vinyl alcohol structure (-(CH2)2-CH(OH)CH2-). For example, the EVOH-based polymer can include a compound having an ethylene vinyl alcohol structure and having one or more substituents.

[0027] In this specification, "(meth)acrylic acid" may refer to "methacrylic acid (MAA)", "acrylic acid (AA)", or both. "(meth)acrylate" may refer to methacrylate, acrylate, or both.

[0028] The disclosure will now be described in more detail. However, the drawings accompanying this specification are illustrative of preferred embodiments of the disclosure and, together with the detailed description of the invention, serve to further aid in understanding the technical concept of the disclosure. Therefore, this disclosure should not be construed as being limited solely to what is shown in the drawings.

[0029] According to exemplary embodiments, the polymer blend composition includes an EVOH-based polymer. The EVOH-based polymer can reduce the gas permeability of the polymer blend composition, improve mechanical properties such as tensile strength and impact strength, and achieve barrier properties.

[0030] The EVOH-based polymer may have ethylene repeating units and vinyl alcohol repeating units. The EVOH-based polymer may further have other polymer repeating units, and may have ethylene repeating units and / or vinyl alcohol repeating units substituted with functional groups. For example, the EVOH-based polymer may further have vinyl acetate repeating units, propylene repeating units, and the like.

[0031] According to exemplary embodiments, the EVOH-based polymer may include an ethylene vinyl alcohol copolymer. In some embodiments, the EVOH-based polymer may be substantially composed of an ethylene vinyl alcohol copolymer.

[0032] For example, the EVOH-based polymer may have repeating units represented by the following chemical formula 1.

[0033] [ka]

[0034] In chemical formula 1, the number of ethylene repeating units and vinyl alcohol repeating units can be determined by considering the molecular weight and / or melt index of the EVOH-based polymer.

[0035] According to exemplary embodiments, the ethylene content in the EVOH-based polymer may be 15 mol% to 50 mol%. For example, the ethylene content in the EVOH-based polymer may be 15 mol% to 50 mol%, and the vinyl alcohol content may be 50 mol% to 85 mol%.

[0036] In some embodiments, the ethylene content in the EVOH-based polymer may be 20 mol% to 45 mol%, 22 mol% to 42 mol%, 25 mol% to 40 mol%, or 27.5 mol% to 37.5 mol%.

[0037] This makes it possible to improve the miscibility between an EVOH-based polymer containing ethylene within the aforementioned range and an EA-based polymer containing (meth)acrylic acid within a predetermined range.

[0038] The ethylene content mentioned above can represent the content of ethylene repeating units and can be measured by known methods (e.g., NMR, FTIR, GPC, etc.).

[0039] According to exemplary embodiments, the molecular weight of the EVOH-based polymer may be 10,000 g / mol to 200,000 g / mol, 30,000 g / mol to 150,000 g / mol, or 40,000 g / mol to 100,000 g / mol.

[0040] Within the aforementioned range, it is possible to suppress the deterioration of mechanical properties that may occur during the formation process of polymer blends.

[0041] According to exemplary embodiments, the melt index of the EVOH-based polymer may be 0.1 g / 10 min to 10 g / 10 min.

[0042] In some embodiments, the melt index of the EVOH-based polymer may be 0.3g / 10min to 8g / 10min, 0.5g / 10min to 7g / 10min, 0.7g / 10min to 6g / 10min, 0.8g / 10min to 5g / 10min, 0.9g / 10min to 4.5g / 10min, or 1g / 10min to 4g / 10min.

[0043] Within the aforementioned range, the difference with the melt index of the EA-based polymer can be maintained within a predetermined range. This promotes mixing of the EVOH-based polymer and the EA-based polymer, improving the uniformity of the appearance and gas barrier properties of the barrier (e.g., coating, film) formed using the polymer blend composition.

[0044] The melt index can be measured by methods known in the art. For example, it can be measured by the methods of ASTM D1238 or ISO 1133. The unit of the melt index is g / 10min, and it can represent the amount of molten polymer that flows for 10 minutes.

[0045] According to exemplary embodiments, the polymer blend composition includes an EA-based polymer. The EA-based polymer can improve the processability, appearance characteristics, manufacturing efficiency, and / or moisture barrier properties of the polymer blend composition. In some embodiments, the polymer blend composition may include an ethylene acrylic acid (EAA)-based polymer.

[0046] For example, the EA-based polymer can be reacted with the EVOH-based polymer to form a polymer blend composition. This allows for a uniform mixing of the EVOH-based polymer and the EA-based polymer, improving both barrier properties and processability.

[0047] The EA-based polymer may have ethylene repeating units and (meth)acrylic acid repeating units. The EA-based polymer may further have other polymer repeating units, and may have ethylene repeating units and / or vinyl alcohol repeating units substituted with functional groups. For example, the EA-based polymer may include an ionomer formed by the ionic bonding of (meth)acrylic acid repeating units with a metal. For example, it may further have acrylate repeating units, propylene repeating units, and the like.

[0048] According to exemplary embodiments, the EA-based polymer may include an ethylene (meth)acrylic acid copolymer. In some embodiments, the EA-based polymer may be substantially composed of an ethylene (meth)acrylic acid copolymer.

[0049] For example, the EA-based polymer may have a repeating unit represented by the following chemical formula 2, or a repeating unit represented by the following chemical formula 3.

[0050] [ka]

[0051] [ka]

[0052] In chemical formulas 2 and 3, the number of ethylene repeating units and (meth)acrylic acid repeating units can be determined by considering the molecular weight and / or melt index of the EA-based polymer.

[0053] According to exemplary embodiments, the EA-based polymer contains acrylic acid, and the acrylic acid content may be 1% by weight or more and less than 10% by weight. For example, the acrylic acid content in the EA-based polymer may be 1% by weight or more and less than 10% by weight, and the ethylene content may be greater than 90% by weight and less than or equal to 99% by weight.

[0054] In some embodiments, the EA-based polymer contains acrylic acid, and the acrylic acid content may be 3% by weight or more but less than 10% by weight, 3.5% by weight or more but less than 10% by weight, 4% by weight or more but less than 10% by weight, 5% by weight or more but less than 10% by weight, 5.5% by weight to 9.9% by weight, or 6% by weight to 9.8% by weight.

[0055] In one embodiment, the EA-based polymer may also contain methacrylic acid. In one embodiment, the methacrylic acid content in the EA-based polymer may be 1% to 12% by weight. In some embodiments, the methacrylic acid content may be 1.2% to 12% by weight, 3.5% to 12% by weight, 4.5% to 11.9% by weight, or 7% to 11.8% by weight.

[0056] Within the aforementioned range, the processability of the polymer blend composition can be improved. For example, if the (meth)acrylic acid content increases outside the aforementioned range, excessive reaction with EVOH-based polymers can reduce dispersibility, potentially leading to aggregation during processing. Alternatively, dispersibility may not be ensured, making processing impossible. For example, if the (meth)acrylic acid content decreases outside the aforementioned range, the number of gel-fish eyes increases, reducing mechanical strength and preventing the achievement of barrier properties.

[0057] The content of acrylic acid or methacrylic acid can represent the content of repeating acrylic acid units or repeating methacrylic acid units, respectively, and can be measured by known methods (e.g., NMR, FTIR, GPC, etc.).

[0058] In some embodiments, the acrylic acid content in an EA-based polymer containing acrylic acid may be greater than the methacrylic acid content in an EA-based polymer containing methacrylic acid. For example, an EA-based polymer can be a polymer containing acrylic acid or a polymer containing methacrylic acid, and the methacrylic acid content in the methacrylic acid-containing polymer may be about 10% to 30% greater than the acrylic acid content in the acrylic acid-containing polymer. This makes it possible to prepare a polymer blend composition with the desired physical properties.

[0059] According to exemplary embodiments, the molecular weight of the EA-based polymer may be between 50,000 g / mol and 150,000 g / mol.

[0060] In some embodiments, the molecular weight of the EA-based polymer may be 70,000 g / mol to 140,000 g / mol, 75,000 g / mol to 135,000 g / mol, 80,000 g / mol to 130,000 g / mol, 85,000 g / mol to 125,000 g / mol, or 90,000 g / mol to 120,000 g / mol.

[0061] Within the aforementioned range, the dispersibility of the EA-based polymer is ensured, and improved processability and mechanical properties can be achieved. Furthermore, the decrease in the barrier properties of the EVOH-based polymer can be suppressed.

[0062] According to exemplary embodiments, the melt index of the EA-based polymer may be 0.1 g / 10 min to 20 g / 10 min.

[0063] In some embodiments, the melt index of the EA-based polymer may be 0.3g / 10min to 17g / 10min, 0.5g / 10min to 15g / 10min, 0.6g / 10min to 12g / 10min, 0.7g / 10min to 10g / 10min, 0.8g / 10min to 9g / 10min, 0.9g / 10min to 8g / 10min, or 1g / 10min to 7g / 10min.

[0064] Within the aforementioned range, fluidity can be ensured by the EA-based polymer. As a result, the polymer blend composition can have improved processability.

[0065] The melt index can be measured by methods known in the art, as described above.

[0066] By adjusting the difference in melt index between the EVOH-based polymer and the EA-based polymer, improved barrier properties (e.g., uniformity of appearance, gas barrier properties, moisture barrier properties, mechanical stability, etc.) and processability can be achieved simultaneously.

[0067] According to an exemplary embodiment, the difference in melt index between the EVOH-based polymer and the EA-based polymer may be 10 g / 10 min or less.

[0068] In some embodiments, the difference in melt index between the EVOH-based polymer and the EA-based polymer may be 8 g / 10 min or less, 6 g / 10 min or less, 5 g / 10 min or less, 4.5 g / 10 min or less, 4 g / 10 min or less, 3.5 g / 10 min or less, or 3 g / 10 min or less.

[0069] The lower limit of the difference in melt index between the EVOH-based polymer and the EA-based polymer is not particularly limited, but may be, for example, 0.01 g / 10 min or more, or 0.1 g / 10 min or more.

[0070] Within the aforementioned range, the processability of the polymer blend composition can be improved. For example, if the difference in melt index exceeds the aforementioned range, the reaction between the EVOH-based polymer and the EA-based polymer increases, which can cause the polymer blend composition to aggregate. As a result, even with the addition of additives, compatibilizers, etc., dispersibility may not be ensured, and the polymer blend composition may not be processable.

[0071] According to an exemplary embodiment, the content of the EA polymer may be 5% by weight or more and less than 40% by weight of the total weight of the polymer blend composition.

[0072] In some embodiments, the content of the EA polymer may be 7% to 38% by weight, 7.5% to 35% by weight, 8% to 32% by weight, or 10% to 30% by weight, based on the total weight of the polymer blend composition.

[0073] Within the aforementioned range, both improved barrier properties and processability can be achieved.

[0074] The content of the aforementioned EA-based polymer may vary depending on the addition of additives and / or compatibilizers described later.

[0075] According to exemplary embodiments, if the polymer blend composition contains one or more additives and compatibilizers, the content of the EA polymer may be 5% by weight or more and less than 60% by weight, 5% by weight to less than 55% by weight, or 5% by weight or more and less than 50% by weight, based on the total weight of the polymer blend composition.

[0076] Even if the content of EA-based polymers increases due to additives and / or compatibilizers, both improved barrier properties and processability can be achieved.

[0077] The content of the EA polymer can also be described based on the total weight of the EVOH polymer and the EA polymer. For example, if other additives (e.g., basic compounds, organic compounds) are also included, the content of the EA polymer can be described based on the total weight of the EVOH polymer and the EA polymer excluding the content of the additives.

[0078] The content of the EVOH polymer may depend on the content of the EA polymer. For example, if the content of the EA polymer is 5% by weight or more and less than 40% by weight of the total weight of the polymer blend composition, the content of the EVOH polymer may be more than 60% by weight and 95% by weight or less of the total weight of the polymer blend composition.

[0079] According to exemplary embodiments, the polymer blend composition may further comprise one or more additives and compatibilizers.

[0080] For example, the additive may include plasticizers, viscosity stabilizers, hydrolysis stabilizers, antioxidants, UV absorbers, antistatic agents, colorants, fillers, flame retardants, lubricants, strengtheners, antiblocking agents, release agents, foaming agents, slip agents, processing aids, and the like.

[0081] According to exemplary embodiments, the additive may include a basic inorganic compound. The basic inorganic compound may be included as a plasticizer and / or processing aid.

[0082] The basic inorganic compound can stabilize the instability of the melt viscosity that occurs during the melting process of the polymer blend composition and suppress side reactions.

[0083] Examples of the aforementioned basic inorganic compounds include calcium oxide (CaO), calcium carbonate (CaCO3), calcium hydroxide (Ca(OH)2), zinc oxide (ZnO), zinc carbonate (ZnCO3), magnesium oxide (MgO), magnesium carbonate (MgCO3), aluminum hydroxide (Al(OH)2), barium hydroxide (Ba(OH)2), lithium hydroxide (LiOH), and potassium hydroxide (KOH).

[0084] According to exemplary embodiments, the additive may also include a basic organic compound.

[0085] Examples of the basic organic compounds include isopropylamine, trimethylamine, triethylamine, tributylamine, benzylamine, dimethylbenzylamine, ethylenediamine, tetraethylammonium bromide, tetraethylammonium chloride, tetrabutylammonium bromide, pyridine, piperidine, and piperazine.

[0086] Since the additive is basic, it can improve the compatibility of acidic EA-based polymers under melt processing conditions. Furthermore, it can suppress side reactions and adjust the crosslinking structure, thereby improving the physical strength and chemical resistance of the polymer blend composition.

[0087] In some embodiments, the additive may not include ceramic additives. The ceramic additive can represent naturally formed minerals. For example, the ceramic additive may include talc, mica, kaolin, clay, wollastonite, silica, quartz, and the like.

[0088] The aforementioned ceramic additive may increase the stiffness of the EVOH polymer, potentially reducing the processability of the polymer blend composition.

[0089] In some embodiments, the content of the additive may be 0.01% by weight or more and less than 3.0% by weight relative to the total weight of the EVOH-based polymer and the EA-based polymer.

[0090] In some embodiments, the content of the additive may be 0.01% to 2.0% by weight, 0.05% to 1.5% by weight, 0.07% to 1.0% by weight, 0.08% or more but less than 1.0% by weight, 0.09% to 0.8% by weight, or 0.1% to 0.5% by weight, relative to the total weight of the EVOH-based polymer and the EA-based polymer.

[0091] Within the aforementioned range, processability can be improved while maintaining improved barrier properties.

[0092] Compatibilizers can improve the compatibility between EVOH-based polymers and EA-based polymers. This suppresses aggregation, gelation, and / or phase separation due to excessive reactions that occur when mixing EVOH-based polymers and EA-based polymers.

[0093] The compatibilizer may include polymers and / or compounds that are physically and chemically reactive with EVOH-based polymers and EA-based polymers. For example, the compatibilizer may include physical compatibilizers, chemical compatibilizers, and the like.

[0094] For example, the compatibilizer may include: polyolefin polymers such as polyethylene, polypropylene, and polybutylene; (meth)acrylate compounds such as methyl acrylate, ethyl acrylate, butyl acrylate, ethyl methacrylate, and glycidyl methacrylate; (meth)acrylate polymers such as ethylene methyl acrylate, ethylene ethyl acrylate, ethylene butyl acrylate, propylene butyl acrylate, butylene ethyl acrylate, and ethylene glycidyl methacrylate; maleic anhydride; and maleic anhydride grafted ethylene propylene rubber. This may include maleic anhydride-based polymers such as rubber, maleic anhydride-grafted polypropylene, ethylene-alkyl (meth)acrylate-(meth)acrylic acid copolymers, and ethylene-vinylacetate copolymers.

[0095] According to exemplary embodiments, the compatibilizer may include one or more of the following: polyolefin polymers, (meth)acrylate polymers, polymers grafted with maleic anhydride, and maleic anhydride.

[0096] In some embodiments, the polyolefin polymer may include one or more of polyethylene, polypropylene, and polybutylene.

[0097] In some embodiments, the (meth)acrylate polymer may include an alkyl (meth)acrylate polymer. The alkyl (meth)acrylate polymer may represent a polymer having alkylene repeating units and (meth)acrylate repeating units. The alkylene repeating unit may have 1 to 5 carbon atoms, and the (meth)acrylate repeating unit may have 1 to 10 carbon atoms. For example, the (meth)acrylate polymer may include ethylene-glycidyl methacrylate.

[0098] In some embodiments, the polymer grafted with maleic anhydride can refer to a polymer obtained by grafting maleic anhydride onto the polyolefin polymer and / or the alkyl (meth)acrylate polymer.

[0099] In one embodiment, the compatibilizer may include one or more of a polymer grafted with maleic anhydride and maleic anhydride.

[0100] The aforementioned type of compatibilizer can improve the interfacial interaction between EVOH-based polymers and EA-based polymers, and assist in the chemical bonding between polymers. This can improve the processability and mechanical properties of the polymer blend composition.

[0101] According to exemplary embodiments, the content of the compatibilizer may be 0.1% by weight or more and less than 10% by weight, relative to the total weight of the EVOH-based polymer and the EA-based polymer.

[0102] In some embodiments, the content of the compatibilizer may be 0.1% to 9% by weight, 0.5% to 8% by weight, 0.7% to 7.5% by weight, 0.8% to 6% by weight, or 1% to 5% by weight, relative to the total weight of the EVOH-based polymer and the EA-based polymer.

[0103] Within the aforementioned range, excessive reactions between EVOH-based polymers and EA-based polymers can be suppressed, improving processability.

[0104] The polymer pellets according to the embodiments of this disclosure may include the polymer blend compositions according to the embodiments described above.

[0105] The polymer pellets can be produced from the polymer blend composition according to the above-described embodiment. The polymer pellets can be formed using the improved processability of the polymer blend composition according to the above-described embodiment.

[0106] For example, polymer pellets can be produced by extruding the aforementioned polymer blend composition. The extrusion method is not limited, but the aforementioned polymer blend composition can be extruded by single extrusion, double extrusion, dispersion extrusion, etc.

[0107] Polymer pellets can improve handling properties (e.g., long-term storage and transportability).

[0108] The polymer film according to the embodiments of this disclosure may include the polymer blend composition according to the embodiments described above.

[0109] The polymer film can be produced from the polymer blend composition according to the above-described embodiment. The polymer film can also be produced from polymer pellets according to the above-described embodiment.

[0110] For example, a polymer film can be produced by extruding the polymer pellets. The uniformity of the polymer film produced from the polymer pellets can be improved, and the defective rate can be reduced.

[0111] The polymer film containing the polymer blend composition according to the above embodiment may have improved barrier properties. Examples of the barrier properties include gas barrier properties that block the permeation of oxygen, carbon dioxide, water vapor, etc.; chemical stability that suppresses the reaction with external compounds; thermal stability that suppresses changes due to heat, ultraviolet rays, etc.; mechanical stability that shows resistance to physical impacts such as tensile strength and impact strength; uniformity due to reduction of impurities; and the like. When one or more of the above-described properties are improved, it can be considered that the barrier properties are improved.

[0112] According to an exemplary embodiment, the thickness of the polymer film may be 1 μm to 100 μm. The thickness of the polymer film can be adjusted according to the required barrier properties and the applicable technical field.

[0113] According to an exemplary embodiment, the gas barrier property of the polymer film is 10 cc / m 2 ·day or less, 9 cc / m 2 ·day or less, 8 cc / m 2 ·day or less, 7.5 cc / m 2 ·day or less, 7 cc / m 2 ·day or less, 6.8 cc / m 2 ·day or less, or 6 cc / m 2 ·day or less may be acceptable.

[0114] The lower limit of the gas barrier property of the polymer film is not particularly limited. For example, it may be 0.05 cc / m 2 ·day or more, or 0.1 cc / m 2 ·day or more may be acceptable.

[0115] For example, the gas barrier property can represent oxygen barrier property.

[0116] For example, the gas barrier property may be a value based on a polymer film thickness of 20 μm. Alternatively, the gas barrier property may represent a value measured according to ISO 14663-2 anexC Condition.

[0117] According to an exemplary embodiment, the gel and fish-eyes formed on the polymer film are 9,000 per square meter. 2 Below 8,000 pieces / m 2 The following, or 7,000 pieces / m 2 The following is also acceptable.

[0118] The gel and fisheye can be measured visually or using a thermal analyzer or the like. For example, the gel and fisheye can be measured using an optical control system (OCS). For instance, the gel and fisheye can be expressed as the area of ​​all gels with a diameter of 200 μm or less in the polymer film divided by the unit area. The gel and fisheye values ​​can represent values ​​measured under specific software settings (e.g., Sensitivity 70).

[0119] The measured values ​​of the gel and fisheye formed on the polymer film are relative comparisons with polymer films of different compositions under the same measurement conditions, and do not represent absolute values ​​for the polymer film. For example, if the measurement conditions change, the measured values ​​of the gel and fisheye may fall outside the range.

[0120] The following are specific examples to aid in understanding the present invention. These examples are merely illustrative of the present disclosure and do not limit the scope of the appended claims. It will be apparent to those skilled in the art that various changes and modifications to the examples are possible within the scope of the present disclosure and the technical concept, and that such variations and modifications naturally fall within the scope of the appended claims.

[0121] Examples and Comparative Examples Polymer blend compositions were prepared according to the components and their contents shown in Tables 1-3 below.

[0122] Example 1 A polymer blend composition was prepared by melting 70% by weight of ethylene vinyl alcohol copolymer (EVOH) containing 32 mol% ethylene and 30% by weight of ethylene acrylic acid copolymer (EAA) containing 9.7% by weight acrylic acid, and mixing them using a mixer. The EAA content was measured according to ASTM D4094, and the melt indices of EVOH and EAA were measured according to ASTM D1238. The melt index of EVOH was 1.6 g / 10 min, and the melt index of EAA is shown in Table 1.

[0123] Examples 2-9 A polymer blend composition was prepared in the same manner as in Example 1, except that the acrylic acid content, melt index, and / or molecular weight of the ethylene acrylic acid copolymer (EAA) were changed as shown in Table 1 below.

[0124] Comparative Examples 1-2 A polymer blend composition was prepared in the same manner as in Example 1, except that the acrylic acid content, melt index, and / or molecular weight of the ethylene acrylic acid copolymer (EAA) were changed as shown in Table 1 below.

[0125] Examples 10-14 A polymer blend composition was prepared in the same manner as in Example 1, except that the content of ethylene vinyl alcohol copolymer (EVOH) and ethylene acrylic acid copolymer (EAA) was changed as shown in Table 2 below.

[0126] Comparative Examples 3-4 A polymer blend composition was prepared in the same manner as in Example 1, except that the content of ethylene vinyl alcohol copolymer (EVOH) and ethylene acrylic acid copolymer (EAA) was changed as shown in Table 2 below.

[0127] Examples 15-25 The polymer blend composition prepared in the same manner as in Example 1 was to which additives and compatibilizers were added as shown in Table 3 below. The content of the additives and compatibilizers is shown based on 100 parts by weight of the EVOH and EAA mixture before the addition of the additives and compatibilizers.

[0128] [Table 1]

[0129] [Table 2]

[0130] [Table 3]

[0131] Manufacturing example The polymer blend composition was extruded using a twin-screw extruder to produce polymer pellets. Polymer pellets were melt-extruded using a single-screw extruder to produce polymer films.

[0132] Experimental example (1) Analysis of oxygen transmission rate The oxygen permeability of a 20 μm thick polymer film was analyzed using an oxygen permeability measuring device (MOCON, OX-TRON) under conditions of 23°C and 65% RH relative humidity.

[0133] (2) Analysis of gel and fish-eye Impurities present within a predetermined area of ​​the polymer film were counted using the program (FSA100 software) of an optical control system (OCS, ME20, GmbH). Measurements were taken in units of GI200 (area of ​​the entire gel with a diameter of 200 μm or less / unit area) under a sensitivity of 70. The gel and fisheyes were evaluated according to the following criteria. <Analytical Criteria for Gel and Fish Eye Analysis> ○: 7,000 gels and fish eyes / m² 2 below Δ: 7,000 gels and fish eyes / m² 2 Over 10,000 pieces / m 2 below ×: Gel and fish eyes: 10,000 pieces / m 2 exceed

[0134] (3) Analysis of impact strength The impact strength of polymer films was measured using an impact strength measuring device (Falling Dart tester, manufactured by TOYOSEIKI Corporation) in accordance with the ASTM D1790-A method. The impact strength was measured using a polymer film with a thickness of 50 μm. The impact strength was evaluated according to the following criteria. <Analysis Criteria for Impact Strength> ○: Analysis by ASTM D1790-A method indicates that the weight of the dropped weight is 96g or more. Δ: In analysis using the ASTM D1790-A method, the weight of the dropped weight was between 66g and 96g. ×: In analysis using the ASTM D1790-A method, the weight of the dropped weight was less than 66g.

[0135] (4) Analysis of the processability of polymer compositions (1) During the production of polymer pellets, the RPM of the strand cutter was measured. Uniformity was evaluated according to the following criteria. <Analysis Criteria for Processability (1)> ○: Strand cutter rpm is 40 or higher Δ: The rpm of the strand cutter is between 30 and 40. ×: Strand cutter rpm is less than 30

[0136] (5) Analysis of the processability of polymer compositions (2) The load on the twin-screw extruder was measured during the production of polymer pellets. The load was measured by motor current and motor torque and evaluated according to the following criteria. <Analysis Criteria for Processability (2)> ○: Motor current is 20A or more and 50A or less, and motor torque is 100N·m or less. Δ: Motor current exceeds 50A, and motor torque is 100N·m or less. ×: Motor current is less than 20A or more than 50A, and motor torque is more than 100N·m.

[0137] The evaluation results from the above experimental example are shown in Table 4 below.

[0138] [Table 4]

[0139] Referring to Table 4 above, the processability of the polymer blend composition according to the examples was improved, the oxygen permeability of the film produced from the polymer blend composition decreased, the number of gel-fish eyes decreased, and the impact strength increased. Therefore, it was confirmed that a film with improved mechanical strength and gas barrier properties could be produced.

[0140] The polymer compositions or polymer blend compositions in the comparative examples were either impossible to process or exhibited low processability. Furthermore, the films produced using the polymer compositions or polymer blend compositions in the comparative examples showed low oxygen barrier properties, a high number of gel-fish eyes, and / or low impact strength.

[0141] In Example 4, where the difference in melt index between EVOH and EAA was relatively large, the number of gel-fish eyes increased relatively, and the impact strength decreased.

[0142] In Example 9, where the acrylic acid content in the EAA was relatively low, the number of gel-fish eyes increased relatively, and the impact strength decreased.

[0143] In Examples 12-14, where the proportion of EAA was relatively high, oxygen permeability increased.

[0144] In Example 17, where the additive content was relatively high, the number of gel-fish eyes increased.

[0145] In Examples 18 and 19, which used ceramic additives, the number of gel-fish eyes increased relatively, impact strength decreased, and processability decreased relatively.

[0146] In Example 23, which had a relatively high content of the compatibilizer, the impact strength decreased.

[0147] In the analysis of processability (2), in Examples 15-19, which used additives, the motor torque of the twin-screw extruder during polymer pellet production was within the appropriate range, but the motor current was somewhat high, resulting in relatively low processability.

[0148] In Examples 20-23, which used (meth)acrylate polymers or maleic anhydride compatibilizers, and in Example 25, which used both additives and compatibilizers, the twin-screw extruder showed normal operation during polymer pellet production, demonstrating high processability.

[0149] In Comparative Examples 1-4, both the motor current and motor torque were outside the appropriate range, resulting in poor machinability that could potentially put undue stress on the equipment and materials.

Claims

1. Ethylene vinyl alcohol-based polymers, A polymer blend composition comprising an ethylene (meth)acrylic acid-based polymer having a (meth)acrylic acid content of 1% or more and less than 10% by weight.

2. The polymer blend composition according to claim 1, wherein the content of the (meth)acrylic acid in the ethylene (meth)acrylic acid-based polymer is 5% by weight or more and less than 10% by weight.

3. The polymer blend composition according to claim 1, wherein the difference in melt index between the ethylene vinyl alcohol-based polymer and the ethylene (meth)acrylic acid-based polymer is 10 g / 10 min or less.

4. The polymer blend composition according to claim 3, wherein the melt index of the ethylene (meth)acrylic acid-based polymer is 0.1 g / 10 min to 20 g / 10 min.

5. The polymer blend composition according to claim 3, wherein the melt index of the ethylene vinyl alcohol-based polymer is 0.1 g / 10 min to 10 g / 10 min.

6. The polymer blend composition according to claim 1, wherein the molecular weight of the ethylene (meth)acrylic acid-based polymer is 50,000 g / mol to 150,000 g / mol.

7. The polymer blend composition according to claim 1, wherein the content of the ethylene (meth)acrylic acid polymer is 5% by weight or more and less than 40% by weight of the total weight of the polymer blend composition.

8. The polymer blend composition according to claim 1, further comprising an additive containing a basic inorganic compound.

9. The polymer blend composition according to claim 8, wherein the content of the additive is 0.01% by weight or more and less than 3.0% by weight, relative to the total weight of the ethylene vinyl alcohol polymer and the ethylene (meth)acrylic acid polymer.

10. The polymer blend composition according to claim 1, further comprising a polyolefin polymer, a (meth)acrylate polymer, a polymer grafted with maleic anhydride, and a compatibilizer containing one or more of maleic anhydride.

11. The polymer blend composition according to claim 10, wherein the content of the compatibilizer is 0.1% by weight or more and less than 10% by weight with respect to the total weight of the ethylene vinyl alcohol polymer and the ethylene (meth)acrylic acid polymer.

12. The polymer blend composition according to claim 1, wherein the ethylene content in the ethylene vinyl alcohol-based polymer is 15 mol% to 50 mol%.

13. A polymer pellet comprising the polymer blend composition described in claim 1.

14. A polymer film comprising the polymer blend composition described in claim 1.

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