Ethylene vinyl alcohol copolymer resin composition, film and multilayer structure thereof

Abstract

To provide an ethylene-vinyl alcohol copolymer resin composition, a film of the same, and a multilayer structure.SOLUTION: There are provided an ethylene-vinyl alcohol copolymer (EVOH) resin composition and / or a pellet of the same, which include at least one fluorine-containing particle. The ethylene-vinyl alcohol copolymer resin composition and / or the pellet of the same can have a melting pressure of 1.7-7.0 MPa at a shear rate of 20 s-1 and a melting temperature of 190°C. Charpy impact strength according to ISO 179-1 of an EVOH film formed of the EVOH can be at least 2.3 KJ / m2 at 23°C. Elongation at break according to ISO 527-2 of the film can be at least 17.8% at 23°C.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) The claims of this application claim priority to U.S. patent application Ser. No. 16 / 729,984, entitled "Ethylene Vinyl Alcohol Pellets and Films Thereof," filed December 30, 2019, and is a continuation-in-part of that application, the entire contents of which are incorporated herein by reference.

[0002] (Technical field) The present invention relates to an ethylene-vinyl alcohol copolymer (EVOH) resin composition and pellets thereof. The ethylene-vinyl alcohol copolymer resin composition contains particles, particularly fluorine-containing particles. The EVOH resin composition is melt-melted at a shear rate of 20 s -1 The ethylene-vinyl alcohol copolymer resin composition may have a melt pressure of 1.7 to 7.0 MPa at a temperature of 190° C. The present invention further discloses a film and a multilayer structure formed from the ethylene-vinyl alcohol copolymer resin composition and / or pellets. [Background technology]

[0003] EVOH resins are widely used in multilayers to preserve perishable goods. For example, EVOH resins and multilayers are commonly used in the food packaging, medical device and accessory, pharmaceutical, electronics, and agricultural chemical industries. EVOH resins are typically added as a separate layer in multilayers and used as an oxygen barrier layer.

[0004] Die buildup is a common problem in extrusion processes using EVOH. Another common problem in extrusion processes using EVOH is the undesirable occurrence of screw sticking. This problem can degrade the appearance and mechanical strength of films formed from EVOH. This problem has not yet been adequately addressed or resolved in the prior art.

[0005] Therefore, there is a continuing need for EVOH resins that provide better film mechanical properties and allow for cost-effective manufacturing processes. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention relates to an ethylene-vinyl alcohol copolymer (EVOH) resin composition containing particles, particularly fluorine-containing particles. The EVOH resin composition can be in the form of pellets, films, fibers, or the like. The EVOH resin composition can be used to prepare films or multilayer structures. Because EVOH and fluoropolymers are immiscible, it is common knowledge to avoid combining them. For example, the immiscibility of EVOH and fluoropolymers can be expected to negatively affect the appearance and mechanical properties of the resulting film. [Means for solving the problem]

[0007] While the combination of EVOH and fluorinated polymers (also called fluoropolymers) has traditionally been avoided due to problems caused by immiscibility, the present inventors have discovered that when EVOH resin compositions are prepared using fluoropolymers, the partial miscibility of the fluoropolymers can improve material deposition in the die and reduce screw sticking problems. The inventors have also discovered that the EVOH resin compositions of the present invention can improve the plasticity and enhance the mechanical properties of films and multilayer structures formed therefrom. Specifically, the inventors have discovered that the use of EVOH resin compositions containing fluorine-containing particles can result in EVOH films with improved strength (e.g., as measured by Charpy impact testing) and improved plasticity (e.g., as measured by elongation at break).

[0008] In another embodiment of the present invention, the EVOH resin composition (or pellets thereof) is subjected to a shear rate of 20 s -1At a temperature of 190°C, it has a melt pressure of 1.7 to 7.0 MPa. For example, a typical EVOH resin composition may contain an ethylene-vinyl alcohol copolymer and one or more types of fluorine-containing particles. Among them, the ethylene-vinyl alcohol copolymer resin composition has a melt pressure of 1.7 to 7.0 MPa at a shear rate of 20 s -1 At a temperature of 190°C, the melt pressure of the EVOH resin composition is 1.7 to 7.0 MPa. Surprisingly, the melt pressure of the EVOH resin composition is -1 It has been found that when the pressure is within the range of 1.7 to 7.0 MPa at a temperature of 190°C, an EVOH resin composition having improved performance over a wide range of ethylene contents can be obtained.

[0009] The EVOH resin composition described above can further contain one or more types of fluorine-containing particles, and the fluorine-containing particles include a fluorinated polymer. Each fluorine-containing particle preferably has a diameter or major axis length of less than 20 μm. In some circumstances, each fluorine-containing particle has a diameter or major axis length of 0.5 to about 19 μm. Based on the total weight of carbon, oxygen, and fluorine elements, the fluorine-containing particles described above can contain about 1.5 to about 48 wt% fluorine. Surprisingly, it has been found that particle sizes within a certain range can improve film appearance and die deposition.

[0010] As a non-limiting example, the EVOH resin composition has at least two melting point temperatures, or simply stated, at least a first melting point temperature and a second melting point temperature, where the first melting point temperature may be about 100°C to about 140°C or 105°C to 135°C, and the second melting point temperature may be about 150°C to about 195°C or 158°C to 190°C.

[0011] The EVOH resin composition was subjected to a shear rate of 20 s -1 In some cases, the EVOH resin composition may have a melt pressure of 1.7 to 6.8 MPa at a temperature of 190°C. -1 At a temperature of 190°C, the strength is 0.4 to 2.4 kN. Melting It has a melting force.

[0012] Additionally, the ethylene-vinyl alcohol copolymer of the EVOH resin composition may have a degree of saponification of 99.5 mole % or higher. The ethylene-vinyl alcohol copolymer may have an ethylene content of about 20 to about 50 mole %. For example, the ethylene content of the ethylene-vinyl alcohol copolymer may be about 25 to about 45 mole %. In some embodiments, the EVOH resin composition does not contain a polyalkylene oxide.

[0013] The fluorine-containing particles of the EVOH resin composition preferably have a particle size of about 0.5 to about 19 μm. For example, the particle size of the fluorine-containing particles may be about 1.2 to about 16 μm.

[0014] According to at least one embodiment, the EVOH resin composition comprises an ethylene-vinyl alcohol copolymer, the ethylene-vinyl alcohol copolymer having an ethylene content and a saponification degree, wherein the ethylene content is about 20 to about 50 mole % and the saponification degree is 99.5 mole % or more; the EVOH resin composition further comprises at least two melting points, including a first melting point temperature and a second melting point temperature, wherein the first melting point temperature is about 100°C to about 140°C and the second melting point temperature is about 150°C to about 195°C; and the EVOH resin composition further comprises fluorine-containing particles dispersed in the EVOH resin composition, wherein the melting pressure of the EVOH resin composition is 1.7 to 7.0 MPa.

[0015] The film formed from the above-mentioned EVOH resin composition typically has a thermal conductivity of at least 2.3 KJ / m 2 The film has a Charpy impact strength of at least 2.6 KJ / m (e.g., at 23°C according to ISO 179-1) and an elongation at break of at least 17.8% (at 23°C according to ISO 527-2). 2 Preferably, in some circumstances, the film has an elongation at break of at least 20%. Surprisingly, the EVOH resin composition having fluorine-containing particles described herein advantageously improves the strength and plasticity of films formed from pellets of the EVOH resin composition. [Brief explanation of the drawings]

[0016] Practice of the techniques of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0017] [Figure 1] 1 is a cross-sectional view of an exemplary EVOH resin composition of the present invention. [Figure 2] FIG. 1 is a diagram of two melting point temperatures of exemplary EVOH resin compositions of the present invention. [Figure 3] FIG. 1 is a cross-sectional view of the EVOH resin composition of the present invention being melted and flowing through an extruder.

[0018] It should be understood that aspects of the present invention are not limited to the arrangements, instrumentalities and characteristics shown in the accompanying drawings. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention relates to an ethylene-vinyl alcohol copolymer (EVOH) resin composition having particles, particularly fluorine-containing particles, dispersed therein. The EVOH resin composition can be used to prepare films or multilayer structures.

[0020] In one aspect, the present invention provides an EVOH resin composition. The EVOH resin composition may be in the form of pellets, films, fibers, etc. The EVOH pellets described herein refer to the form and / or shape of one or more pellets formed by granulating the EVOH resin composition. While the present specification describes an EVOH resin composition in the form of one or more EVOH pellets formed by granulation, the EVOH resin composition may also be processed into the form of beads, cubes, chips, shavings, etc. The EVOH resin composition of the present invention typically contains an ethylene-vinyl alcohol copolymer and at least one fluorine-containing particle, and the particle size of the fluorine-containing particle is 20 μm or less.

[0021] FIG. 1 illustrates a cross-sectional view of an exemplary EVOH resin composition 100 of the present invention. The EVOH resin composition 100 is formed from EVOH, which has an ethylene content. For example, the ethylene content of the EVOH may be about 20 to about 50 mole%, about 25 to about 45 mole%, about 28 to about 42 mole%, or about 30 to about 40 mole%. The EVOH resin composition 100 may be formed from two or more types of EVOH having different ethylene contents. For example, the ethylene content of one of the types of EVOH may be in the range of about 20 to about 35 mole%, such as about 24 to about 35 mole%, about 28 to about 35 mole%, about 20 to about 32 mole%, about 24 to about 32 mole%, about 28 to about 32 mole%, about 20 to about 30 mole%, or about 24 to about 30 mole%. Additionally, the ethylene content of one of the EVOHs may be in the range of about 36 to about 50 mole%, such as about 40 to about 50 mole%, about 44 to about 50 mole%, about 36 to about 45 mole%, or about 40 to about 45 mole%. However, in some preferred embodiments, the EVOH resin composition 100 is formed from a single EVOH having an ethylene content of about 20 to about 50 mole%.

[0022] The fluorine content of the EVOH resin composition 100 is related to the addition of one or more fluoropolymers (also referred to herein as "fluoropolymers"), which can form fluorine-containing particles 110 dispersed in the EVOH resin composition 100. For example, the one or more fluoropolymers can include or be selected from polyvinylidene fluoride (PVDF), polytetrafluoroethylene, polyhexafluoropropylene, polychlorotrifluoroethylene (PCTFE), 2-chloropentafluoropropene, dichlorodifluoroethylene, 1,1-dichlorofluoroethylene, and combinations thereof. Additionally / alternatively, the fluoropolymer may include a copolymer derived from at least one of vinylidene fluoride (VDF), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE). In some embodiments, the fluoropolymer may include a copolymer derived from two or more of VDF, HFP, and TFE. For example, the EVOH resin composition 100 may include a copolymer derived from VDF and HFP, a copolymer derived from TFE and HFP, a copolymer derived from VDF and TFE, and / or a copolymer derived from VDF, HFP, and TFE. Without being limited to any particular theory, the inventors believe that reducing the crystal size of the fluoropolymer may lower the melting point of at least one of the EVOH resin composition 100, thereby reducing the energy required for the processing.

[0023] The fluorine-containing particles 110 can have about 1.5 to about 48 wt% fluorine, based on the total weight of the carbon, oxygen, and fluorine elements of the fluorine-containing particles 110. In other embodiments, the fluorine-containing particles 110 can have about 1.5 to about 47.2 wt% fluorine, about 1.8 to about 44 wt% fluorine, or about 2.1 to about 41 wt% fluorine, based on the total weight of the carbon, oxygen, and fluorine elements of the fluorine-containing particles 110.

[0024] The EVOH resin composition 100 has fluorine-containing particles 110, which may be in the form of fine particles, and according to the International Union of Pure and Applied Chemistry (IUPAC), the definition of fine particles is 10 -7 ~10 -4The particle diameter of the microparticles of the present invention is preferably 0.5 to about 19 μm, 1.0 to about 19 μm, or 1.2 to about 16 μm in terms of the length of the major axis across the diameter or cross-sectional area. The size of the fluorine-containing particles can be controlled by adjusting the type or variety of fluoropolymer, the amount of fluoropolymer, and the ethylene content of the EVOH. When the fluorine-containing particles are spherical, whether or not they have a desired particle diameter is determined by the diameter of their cross-section. When the fluorine-containing particles are not spherical and / or the cross-sectional shape of the fluorine-containing particles is not circular (e.g., elliptical or blocky), whether or not they have a desired particle diameter is determined by the length of the major axis of the cross-section of the fluorine-containing particles. The major axis is defined as the axis with the longest length. In some embodiments, the particle diameters of all fluorine-containing particles 110 evaluated on the cross-section of the EVOH resin composition 100 are all 20 μm or less, for example, 19 μm or less, 18 μm or less, 16 μm or less, 14 μm or less, or 12 μm or less. In other words, in some embodiments, the particle size of the fluorine-containing particles 110 does not exceed 20 μm, e.g., 19 μm, 18 μm, 16 μm, 14 μm, or 12 μm. The particle size of the fluorine-containing particles 110 may be 0.1 μm or more, 0.3 μm or more, 0.5 μm or more, or 0.7 μm or more. For example, the EVOH resin composition 100 may have fluorine-containing particles 110 with a particle size of 1.0 to about 19 μm or 1.2 to about 16 μm. In some embodiments, all of the fluorine-containing particles 110 evaluated on a cross-section of the EVOH resin composition 100 are within the desired particle size range described herein. However, in some embodiments, the majority of the fluorine-containing particles 110 evaluated on a cross-section of the EVOH resin composition 100 are within the desired particle size range. Exemplary factors that influence whether the particle size is within the desired range can include (a) the amount of fluoropolymer, (b) the ethylene content of the EVOH, (c) the type of fluoropolymer, (d) the temperature in the extruder, and (e) the rotation speed of the screw.

[0025] As shown in Figure 2, the EVOH resin composition 100 can have at least two melting point temperatures. In some embodiments, one melting point temperature (e.g., a first melting point temperature) in the EVOH resin composition 100 is about 100°C to about 140°C, e.g., about 105°C to about 135°C, about 110°C to about 135°C, or about 120°C to about 130°C, where the first melting point temperature corresponds to the melting point temperature of the fluoropolymer. Further / or, one of the melting point temperatures (e.g., a second melting point temperature) is about 150°C to about 195°C, e.g., about 158°C to about 190°C, or about 164°C to about 187°C, where the second melting point temperature corresponds to the melting point temperature of the EVOH, which varies depending on the ethylene content of the EVOH. In some embodiments, the EVOH resin composition 100 has at least three different melting point temperatures. In other embodiments, the EVOH resin composition 100 has at least four, at least five, or at least six different melting point temperatures, and / or the EVOH resin composition 100 may have a degree of saponification of 90 mole % or greater, preferably 95 mole % or greater, preferably 97 mole % or greater, and preferably 99.5 mole % or greater.

[0026] The EVOH resin composition 100 described above can be free or substantially free of polyalkylene oxide. For example, the EVOH resin composition 100 can have less than 5 wt% polyalkylene oxide, such as less than 4 wt%, less than 3 wt%, less than 2 wt%, less than 1 wt%, or less than 0.5 wt%.

[0027] The EVOH resin composition 100 described above contributes to more efficient preparation of EVOH films formed therefrom. For example, the EVOH resin composition 100 can improve die deposition and reduce screw sticking problems during the production of EVOH films. Suitable methods and equipment for preparing EVOH films include those readily understood by those skilled in the art. The inventors believe that by using a partially miscible (and partially immiscible) fluoropolymer to prepare the EVOH resin composition 100 containing fluorine-containing particles 110, some of the fluoropolymer will separate on the inner surface of the extruder, forming a coating layer 120. Figure 3 illustrates the coating layer 120 formed on the inner surface of the extruder by a portion of the fluoropolymer of the EVOH pellets of the present invention. Furthermore, the fluoropolymer layer coating the inner wall of the extruder protects the EVOH resin flowing through the extruder, which is advantageous in preventing discoloration of the EVOH film even when the EVOH pellets are extruded at high temperatures.

[0028] In another embodiment, the EVOH resin composition provided by the present invention is -1 At a temperature of 190°C, the melt pressure of the EVOH resin composition is 1.7 to 7.0 MPa. Surprisingly, the melt pressure of the EVOH resin composition is -1It has been found that an EVOH resin composition with improved performance over a wide range of ethylene contents can be obtained when the melt pressure is within the desired range of 1.7 to 7.0 MPa at 190°C. In the present invention, if the melt pressure of an EVOH resin composition 100 containing fluorine-containing particles 110 falls within the desired range, its processability, mechanical properties, and film appearance can be improved. The EVOH resin composition may contain one or more of the characteristics, attributes, or properties of the EVOH resin and / or pellets discussed herein. The addition of a fluoropolymer can contribute to the screw processing of the EVOH resin composition. In particular, the adhesion of the fluoropolymer to the inner wall of the screw extruder reduces the flow resistance of the EVOH resin composition as it passes through the screw extruder. A capillary rheometer can be used to simulate the behavior of EVOH in a screw extruder. Because the temperature commonly used in EVOH processing is 190°C, this temperature is also often used to analyze the melting / melting behavior of EVOH resin compositions. Shear rate: 20 s -1 This is also within the range of shear rates commonly used in EVOH processing. Also, at this low shear rate, differences in melt behavior can be better reflected. As mentioned above, at a temperature of 190°C and a shear rate of 20 s -1 is a typical parameter in the field of EVOH processing. According to one aspect of the present invention, by controlling the melt pressure in the capillary within a specific range, EVOH can be endowed with characteristics such as good film appearance, processing stability, and improved plasticity and mechanical properties.

[0029] A typical EVOH resin composition may contain ethylene-vinyl alcohol copolymer and one or more kinds of fluorine-containing particles, among which, the ethylene-vinyl alcohol copolymer resin composition is preferably ethylene-vinyl alcohol copolymer at a shear rate of 20 s -1 The melt pressure of the EVOH resin composition is 1.7 to 7.0 MPa at a temperature of 190°C. -1At a temperature of 190°C, 1.7 to 7.0 MPa, 1.7 to about 6.8 MPa, 1.7 to about 6.5 MPa, 1.7 to about 6.2 MPa, 1.7 to about 5.9 MPa, 1.7 to about 5.6 MPa, about 2 to about 6.8 MPa, about 2 to about 6.5 MPa, about 2 to about 6.2 MPa, about 2 to about 5.9 MPa, about 2 to about 5.6 MPa, about 2.3 to about 6.8 MPa , about 2.3 to about 6.5 MPa, about 2.3 to about 6.2 MPa, about 2.3 to about 5.9 MPa, about 2.3 to about 5.6 MPa, about 2.6 to about 6.8 MPa, about 2.6 to about 6.5 MPa, about 2.6 to about 6.2 MPa, about 2.6 to about 5.9 MPa, about 2.6 to about 5.6 MPa, about 2.9 to about 6.8 MPa, about 2.9 to about 6.5 MPa, about 2.9 to about 6 .2MPa, about 2.9 to about 5.9MPa, about 2.9 to about 5.6MPa, about 3.2 to about 6.8MPa, about 3.2 to about 6.5MPa, about 3.2 to about 6.2MPa, about 3.2 to about 5.9MPa, about 3.2 to about 5.6MPa, about 3.5 to about 6.8MPa, about 3.5 to about 6.5MPa, about 3.5 to about 6.2MPa, about 3.5 to about 5.9MPa, about 3 The pressure may be in the range of about 0.5 to about 5.6 MPa, about 3.9 to about 6.8 MPa, about 3.9 to about 6.5 MPa, about 3.9 to about 6.2 MPa, about 3.9 to about 5.9 MPa, about 3.9 to about 5.6 MPa, about 4.2 to about 6.8 MPa, about 4.2 to about 6.5 MPa, about 4.2 to about 6.2 MPa, about 4.2 to about 5.9 MPa or about 4.2 to about 5.6 MPa.

[0030] In some circumstances, the EVOH resin composition may contain boron compounds and / or boric acid and / or cinnamic acid and / or alkali metals and / or conjugated polyenes and / or lubricants and / or alkaline earth metals, which may impart better properties to the EVOH resin composition.

[0031] The EVOH resin composition was subjected to a shear rate of 20 s -1 At a temperature of 190°C, the strength is about 0.04 to about 2.4 kN. Melting For example, a shear rate of 20 s -1 At a temperature of 190°C MeltingThe force is about 0.04 to about 2.4 kN, about 0.04 to about 2.0 kN, about 0.04 to about 1.7 kN, about 0.04 to about 1.4 kN, about 0.04 to about 1.1 kN, about 0.04 to about 1.0 kN, about 0.04 to about 0.8 kN, about 0.06 to about 2.4 kN, about 0.06 to about 2.0 kN, about 0.06 to about 1.7 kN, about 0.06 to about 1.4 kN, about 0.06 to about 1.1 kN, about 0.06 The maximum force may be about 0.1 to about 2.4 kN, about 0.1 to about 2.0 kN, about 0.1 to about 1.7 kN, about 0.1 to about 1.4 kN, about 0.1 to about 1.1 kN, about 0.08 to about 1.0 kN, about 0.1 to about 2.4 kN, about 0.1 to about 2.0 kN, about 0.1 to about 1.7 kN, about 0.1 to about 1.4 kN, or about 0.1 to about 1.1 kN.

[0032] Additionally / alternatively, in another embodiment of the present invention, the EVOH resin composition may contain fluorine-containing particles and a boron content of 10 to 450 ppm. Without being limited to any particular theory, the inventors believe that adding a boron compound to an EVOH resin composition containing fluorine-containing particles and adjusting the boron content of the EVOH to 10 to 450 ppm reduces or eliminates sticking of the EVOH resin composition during the extrusion process in a screw extruder, and improves the uniformity of film thickness and plasticity. Under certain circumstances, such an EVOH resin composition may remove or at least partially remove EVOH resin that has stuck to the inner surface of the screw extruder during the extrusion process, thereby cleaning the screw extruder.

[0033] A typical EVOH resin composition may include an ethylene-vinyl alcohol copolymer, one or more types of fluorine-containing particles, and a boron compound, wherein the boron content of the ethylene-vinyl alcohol copolymer resin composition is 10 to 450 ppm. In some situations, the boron content of the EVOH resin composition may be 10 to 450 ppm, 10 to about 400 ppm, 10 to about 350 ppm, 10 to about 300 ppm, 10 to about 275 ppm, 10 to about 250 ppm, 10 to about 225 ppm, 10 to about 200 ppm, 10 to about 175 ppm, about 20 to 450 ppm, about 20 to about 400 ppm, about 20 to about 350 ppm, or about 20 to about 450 ppm, based on the total weight of the EVOH resin composition. Approx. 300ppm, Approx. 20~Approx. 275ppm, Approx. 20~Approx. 250ppm, Approx. 20~Approx. 225ppm, Approx. 20~Approx. 200ppm, Approx. 60 to about 350ppm, about 60 to about 300ppm, about 60 to about 275ppm, about 60 to about 250ppm, about 60 to about 225ppm, about 60 to about 200ppm, about 60 to about 175ppm, about 100 to 450ppm m, about 100 to about 400ppm, about 100 to about 350ppm, about 100 to about 300ppm, about 100 to about 275ppm, about 100 to about 250ppm, about 100 to about 225ppm, about 100 to about 200ppm , about 100 to about 175ppm, about 140 to 450ppm, about 140 to about 400ppm, about 140 to about 350ppm, about 140 to about 300ppm, about 140 to about 275ppm, about 140 to about 250ppm, about The boron content may be 140 to about 225 ppm, about 140 to about 200 ppm, about 180 to about 450 ppm, about 180 to about 400 ppm, about 180 to about 350 ppm, about 180 to about 300 ppm, about 180 to about 275 ppm, about 180 to about 250 ppm, about 180 to about 225 ppm, about 220 to about 450 ppm, about 220 to about 400 ppm, about 220 to about 350 ppm, about 220 to about 300 ppm, or about 220 to about 275 ppm. When the boron content of the EVOH resin composition is within a certain range, the viscosity of the EVOH resin composition increases, and the EVOH resin composition is less likely to stick to the screw, or the EVOH on the screw can be removed, thereby providing the material with a self-cleaning function and further improving the uniformity of the film thickness.Under certain circumstances, in addition to the boron content being 10 to 450 ppm, the EVOH resin composition may further contain cinnamic acid, alkali metal, conjugated polyene, lubricant, alkaline earth metal, salts thereof, and / or mixtures thereof. The above-mentioned substances are generally present in EVOH resin compositions and contribute to their improved properties. When the content of the compound having a conjugated polyene structure per unit weight in the EVOH resin composition is 1 to 30,000 ppm, heat discoloration is further suppressed and thermal stability can be improved. When the content of the compound having an alkali metal or alkaline earth metal per unit weight in the EVOH resin composition is 1 to 1,000 ppm (metal equivalent), long-run moldability can be improved. Furthermore, when the content of the lubricant per unit weight in the EVOH resin composition is 1 to 300 ppm, processability can be improved.

[0034] In some circumstances, the boron compound may include boric acid or its metal salts. Examples of metal salts include calcium borate, cobalt borate, zinc borate (e.g., zinc tetraborate, zinc metaborate), aluminum potassium borate, ammonium borate (e.g., ammonium metaborate, ammonium tetraborate, ammonium pentaborate, ammonium octaborate), cadmium borate (e.g., cadmium orthoborate, cadmium tetraborate), potassium borate (e.g., potassium metaborate, potassium tetraborate, potassium pentaborate, potassium hexaborate, potassium octaborate), silver borates (e.g., silver metaborate, silver tetraborate), copper borates (e.g., cupric borate, copper metaborate, copper tetraborate), sodium borates (e.g., sodium metaborate, sodium diborate, sodium tetraborate, sodium pentaborate, sodium hexaborate, sodium hexaborate, sodium tetraborate ... sodium octaborate, etc.), lead borates (such as lead metaborate and lead hexaborate), nickel borates (such as nickel orthoborate, nickel diborate, nickel tetraborate and nickel octaborate), barium borates (such as barium orthoborate, barium metaborate, barium diborate and barium tetraborate), bismuth borate, magnesium borates (such as magnesium orthoborate, magnesium diborate, magnesium metaborate, trimagnesium tetraborate and pentamagnesium tetraborate), manganese borates (such as manganous borate, manganese metaborate and manganese tetraborate), lithium borates (such as lithium metaborate, lithium tetraborate and lithium pentaborate), salts thereof or combinations thereof. Examples of suitable inorganic minerals include borate minerals such as borax, kernite, inyoite, cottolite, suanite, and szaibelyite, among which borax, boric acid, and sodium borates (such as sodium metaborate, sodium diborate, sodium tetraborate, sodium pentaborate, sodium hexaborate, and sodium octaborate) are preferably used.

[0035] In another aspect, the present invention provides an EVOH film formed from the EVOH resin composition 100. The EVOH film has a Charpy impact strength according to ISO 179-1 of at least 2.3 KJ / m at 23°C. 2and the EVOH film has an elongation at break according to ISO 527-2 of at least 17.8% at 23° C. In some examples, the EVOH film has a Charpy impact strength according to ISO 179-1 of at least 3 KJ / m at 23° C. 2 , at least 4.5KJ / m 2 , at least 5.5KJ / m 2 or at least 6.5KJ / m 2 To achieve the Charpy impact strength described above, the sample must be conditioned for 16 hours at a relative humidity of 50% ± 5% and a temperature of 23°C ± 2°C before measurement using the ISO 179-1 method. The impact energy must be set to 7.5 J, the impact direction must be edgewise, the sample type must be 1 eA, the average sample width must be 10.06 mm, and the average sample thickness must be 3.94 mm. The test notch depth must be 8.09 mm, the test temperature must be 23°C ± 2°C, and the break type must be C. The EVOH film may have an elongation at break according to ISO 527-2 of at least 20% at 23°C. In some embodiments, the EVOH film has an elongation at break according to ISO 527-2 of at least 21%, at least 22%, at least 23%, or at least 24% at 23°C. To obtain the elongation at break values ​​mentioned above, the 2012 edition of the test method must be used, the test speed must be 50 mm / min, the specimen type must be 1A, and the average specimen thickness must be 3.99 mm.

[0036] In another aspect, the present invention provides a multilayer structure having at least one layer formed from the EVOH resin composition of the present invention, at least one polymer layer, and at least one adhesive layer. The polymer layer can be selected from a low-density polyethylene layer, a polyethylene-grafted maleic anhydride layer, a polypropylene layer, a nylon layer, and combinations thereof. The adhesive layer can be a tie layer, such as ARKEMA OREVAC 18729 from ARKEMA. [Example]

[0037] The non-limiting examples of each aspect of the present invention provided below are primarily intended to clarify each aspect of the present invention and the advantages achieved thereby. [Example]

[0038] Four types of fluoropolymers are prepared according to the present invention (Example fluoropolymers A to D). Then, Example fluoropolymers A to D are used to prepare ethylene-vinyl alcohol copolymer (hereinafter referred to as "EVOH") resin compositions according to the present invention. Example fluoropolymers A to D are prepared according to the specific methods disclosed below, but other types of fluoropolymers can also be used and added to EVOH.

[0039] Example Fluoropolymer A An autoclave was used as a batch reactor to prepare Example Fluoropolymer A. The autoclave had an internal volume of approximately 20 L and was equipped with an electromagnetic induction stirrer. The autoclave was thoroughly filled with nitrogen gas (N2), and then filled with reduced-pressure nitrogen gas five times.

[0040] The autoclave was decompressed and simultaneously charged with 6,960 g of deoxygenated pure water, 3,204 g of 1,1,2-trichloro-1,2,2-trifluoroethane, and 3.5 g of methyl cellulose. The methyl cellulose had a viscosity of 50 cp and was stirred at 450 rpm into the composition in the autoclave as a suspension stabilizer. The composition in the autoclave was then placed at 52°C.

[0041] Monomers composed of 25.3 wt% vinylidene fluoride (VDF), 68.6 wt% hexafluoropropylene (HFP) and 6.1 wt% tetrafluoroethylene (TFE) were mixed into the batch as filler gas at a rate of 10 kg / cm 2The vessel was filled to 1000°C. Then, 45.6 g of a solution containing approximately 90 wt% 1,1,2-trichloro-1,2,2-trifluoroethane and 10 wt% diisopropyl peroxydicarbonate was added as a catalyst to initiate the polymerization reaction. Diisopropyl peroxydicarbonate was used as an initiator to start the polymerization reaction. Since the pressure decreased during the polymerization reaction, a mixed monomer mixture containing 44.7 wt% VDF, 32.5 wt% HFP, and 22.8 wt% TFE was added to raise the pressure to 10 kg / cm. 2 After the polymerization reaction was completed, the remaining mixed monomers were removed, and the resulting suspension was dehydrated using a centrifuge, washed with deionized water, and then vacuum dried at 100°C to obtain 7.5 kg of Example Fluoropolymer A.

[0042] Example Fluoropolymer B A similar autoclave was used to prepare Example Fluoropolymer B, and was set up in the same manner as Example Fluoropolymer A. The autoclave was similarly evacuated and refilled with nitrogen gas five times.

[0043] The autoclave was depressurized and 7,200 g of deoxygenated pure water, 3,250 g of 1,1,2-trichloro-1,2,2-trifluoroethane, and 4 g of methyl cellulose were added to the autoclave. The methyl cellulose had a viscosity of 50 cp and was stirred into the autoclave at 500 rpm as a suspension stabilizer. The autoclave was then heated to 52°C.

[0044] A monomer composed of 25 wt% VDF, 55 wt% HFP and 20 wt% TFE was mixed into the batch as a fill gas at 20 kg / cm 2The vessel was filled to 1000°C. Then, 40 g of a solution containing approximately 85 wt% 1,1,2-trichloro-1,2,2-trifluoroethane and 15 wt% diisopropyl peroxydicarbonate was added as a catalyst to initiate the polymerization reaction. Diisopropyl peroxydicarbonate was used as an initiator to start the polymerization reaction. Since the pressure decreased during the polymerization reaction, a mixed monomer mixture containing 40 wt% VDF, 35 wt% HFP, and 25 wt% TFE was added to maintain the pressure at 20 kg / cm. 2 After the polymerization reaction was completed, the remaining mixed monomers were removed, and the resulting suspension was dehydrated using a centrifuge, washed with deionized water, and then vacuum dried at 100°C to obtain 6 kg of Example Fluoropolymer B.

[0045] Example Fluoropolymer C Example Fluoropolymer C was prepared using the same autoclave and induction stirrer used to prepare Example Fluoropolymer A. The autoclave was fully filled with nitrogen gas, and 3 L of a composition containing deoxygenated purified water and 30 g of ammonium nonadecafluorodecanoate as an emulsifier was added. The composition in the autoclave was heated to 60°C and stirred at 380 rpm.

[0046] After that, the internal pressure of the autoclave was 20 kg / cm 2 A mixed gas containing approximately 70 wt% VDF and approximately 30 wt% HFP was charged into the autoclave until the temperature reached 100°C. Next, 40 g of a solution containing approximately 80 wt% 1,1,2-trichloro-1,2,2-trifluoroethane and 20 wt% diisopropyl peroxydicarbonate was added to the autoclave using nitrogen gas. Diisopropyl peroxydicarbonate was used as an initiator to start the polymerization reaction.

[0047] During the polymerization reaction, a mixed gas of VDF (62 wt%) and HFP (38 wt%) was continuously injected to maintain the internal pressure of the autoclave at 20 kg / cm. 2The temperature was maintained at 100°C. Since the polymerization rate decreased as the polymerization reaction progressed, 3 hours after the start of the polymerization reaction, 30 g of a solution containing approximately 80 wt % of 1,1,2-trichloro-1,2,2-trifluoroethane and 20 wt % of diisopropyl peroxydicarbonate was added to the autoclave using nitrogen gas. After polymerizing the monomers for an additional 3 hours, the resulting suspension was dehydrated using a centrifuge, washed with deionized water, and then vacuum-dried at 100°C to obtain 7.2 kg of Example Fluoropolymer C.

[0048] Example Fluoropolymer D Example Fluoropolymer D was prepared using an autoclave with a volume of approximately 3 L as a batch reactor. The autoclave was equipped with an electromagnetic induction stirrer. A batch of 936 g of deionized water, 0.36 g of methylcellulose, 360 g of VDF, 0.3 g of tert-butyl peroxypivalate, 0.36 g of sodium pyrophosphate, 0.36 g of sodium acid pyrophosphate, and 1.8 g of diethyl carbonate was added to the autoclave, stirred at 10°C for 30 minutes, and then heated at 45°C for 140 minutes.

[0049] The maximum pressure inside the autoclave was 6 MPa. The polymerization reaction of the monomers was completed when the pressure inside the autoclave dropped to 2.5 MPa, which occurred 15 hours after the start of heating the monomers. After the polymerization reaction was completed, the polymer slurry was removed, dehydrated, washed with deionized water, and then dried at 80°C for 24 hours to obtain polyvinylidene fluoride (Example Fluoropolymer D) with an inherent viscosity of 2.05 dL / g and a bulk density of 0.225 g / ml in a yield of 55%. [Example]

[0050] The following provides non-limiting methods for preparing EVOH pellets formed from EVOH resin compositions. Based on methods similar to those disclosed below, 27 non-limiting example EVOHs (Examples EVOH1-27) and 5 comparative EVOH pellets (Comparative Examples EVOH1-5) containing fluorine particles were prepared. However, the specific methods for preparing Example EVOH1-27 and Comparative Examples EVOH1-5 generally differ from the methods disclosed below in one or more aspects.

[0051] An ethylene-vinyl acetate copolymer (EVAC) with an ethylene content of 29 mole percent was saponified to prepare an EVOH polymer with a saponification degree of 99.5%. The EVOH was then dissolved in a solution containing methanol and water (70:30 ratio). The solid content of the EVOH in the solution was then 41 wt% and the solution was placed at 60°C.

[0052] The above-mentioned solution of methanol, water, and EVOH was pelletized by underwater pelletization. Specifically, the above-mentioned solution of methanol, water, and EVOH was pumped through a supply pipe at a flow rate of 120 L / min, then through a suction pipe with a diameter of 2.8 mm, and cut at 1500 rpm using a rotary knife. Water at 5°C was added to cool the EVOH pellets. The EVOH pellets were then centrifuged to separate the EVOH particles. The separated EVOH particles were washed with water and then dried to obtain EVOH pellets.

[0053] EVOH pellets and a fluoropolymer such as that in Example 1 were mixed at a certain ratio and then fed into a twin-screw extruder. As shown in Table 1, the 13 zones (zones 1 to 13) of the twin-screw extruder had different temperatures. After mixing, strand cutting was performed at 25°C to prepare EVOH containing particles containing elemental fluorine (also referred to herein as "fluorine particles"). In Table 1, "EV27" refers to EVOH with an ethylene content of 27 mole%, "EV29" refers to EVOH with an ethylene content of 29 mole%, "EV32" refers to EVOH with an ethylene content of 32 mole%, "EV38" refers to EVOH with an ethylene content of 38 mole%, and "EV44" refers to EVOH with an ethylene content of 44 mole%.

[0054] [Table 1] [Example]

[0055] Films were formed using each of the EVOHs of Examples 1 to 27 according to the method described below. The EVOHs of Examples 1 to 27 and the EVOHs of Comparative Examples 1 to 5 were fed to a monolayer T-die cast film extruder (optical control system MEV4) to prepare films. The thickness of each of the films formed using the EVOHs of Examples 1 to 27 and the EVOHs of Comparative Examples 1 to 5 was 20 μm. The temperature of the extruder was set to 220°C, and the temperature of the mold (i.e., the T-die) was set to 230°C. The screw rotation speed was 7 rpm (rotations / minutes). [Example]

[0056] Examples EVOH 1-27 and Comparative Examples EVOH 1-5 were evaluated to determine the properties of these EVOHs and the films formed therefrom. As described above, Examples EVOH 1-27 were prepared based on a method similar to that described in Example 2. However, the preparation method for EVOH 1-27 differs in that the prepared EVOHs have different ethylene contents, different fluoropolymers, and different fluoropolymer contents. Comparative Examples EVOH 1-5 were also prepared based on a method similar to that described in Example 2.

[0057] Table 2 below summarizes some attributes of Examples EVOH 1-27 and Comparative Examples EVOH 1-5, namely, the ethylene content of the EVAC, the specific fluoropolymer contained in the EVOH pellets, and the fluoropolymer content.

[0058] [Table 2] JPEG0007759183000003.jpg43156

[0059] The performance of Examples EVOH 1-27 was evaluated by comparing a particular Example EVOH with Comparative EVOHs that shared at least one characteristic with the Example EVOH. For example, Table 3 provides a comparison of Examples EVOH 1-5 with Comparative EVOH 1-3, all of which were prepared using EVAC with an ethylene content of 29 mole%. Table 3 also provides a comparison of Examples EVOH 6-10 with Comparative EVOH 4 and 5, all of which were prepared using EVAC with an ethylene content of 44 mole%.

[0060] [Table 3]

[0061] To evaluate the degree of dispersion of particles in Examples EVOH 1-10 and Comparative Examples EVOH 1-5 (if any), one EVOH pellet from each type was taken from Examples EVOH 1-10 and Comparative Examples EVOH 1-5 and cut into 0.5 mm thick samples. The cut surface of each EVOH pellet sample was then evaluated using a LEICA DM2700M optical microscope (Leica Microsystems) and a CCD camera (e.g., manufactured by Leica Microsystems). The cut surface was analyzed using software (e.g., LAS V4.11 software) to measure the cross-sectional length of each fluorine-containing particle. An "X" indicates that the EVOH pellet contained one or more particles with a diameter or major axis length greater than 20 μm, or that no particles were formed. An "O" indicates that the EVOH pellet particles were not coagulated, demonstrating excellent dispersion.

[0062] The fluorine content was measured using a JSM-6390 scanning electron microscope (JEOL USA, INC.). The voltage was set to 15 KV and the working distance was 15 mm. Energy dispersive spectroscopy was performed using an INCA 7582 model (Oxford Instruments). The spot size of the scanning electron microscope was adjusted to make the dead time of the energy dispersive spectroscopy less than 35%. The acquisition rate of the energy dispersive spectroscopy was set to 1 Kcps. The measurements obtained from the scanning electron microscope and energy dispersive spectroscopy were used to determine the k of carbon. α 0.2774 keV, k of oxygen α 0.5249 keV and k of fluorine α According to the element signal peak value of 0.6768 keV, the fluorine content was calculated in weight percent (wt%) based on the total content of carbon, oxygen, and fluorine. In addition, in the energy dispersive spectroscopy analysis process, particles were used as the target of the scanning electron microscope so that the measured fluorine content mainly reflected the fluorine in the particles. Specifically, each of Example EVOH1-10 and Comparative Example EVOH1-5 was evaluated at 10 locations.

[0063] All of Examples EVOH 1-10 exhibited excellent fluorine-containing particle dispersibility and particle sizes within the desired range described herein, whereas Comparative Examples EVOH 1-5 exhibited somewhat poorer dispersibility and particle sizes (if present) exceeded the desired range. As shown in Table 3, Comparative Example EVOH 3 had two melting point temperatures within the desired range described herein and was prepared using EVAC with the same ethylene content as Examples EVOH 1-5. However, Comparative Example EVOH 3 exhibited poor particle dispersibility and severe coagulation, with particle sizes reaching approximately 40 μm. Furthermore, Comparative Example EVOH 5, for example, was prepared using EVAC with the same ethylene content and fluoropolymer as Examples EVOH 6-10. However, the fluoropolymer content of Comparative Example EVOH 5 exceeded the desired range described herein, resulting in poor fluorine-containing particle dispersibility and particle sizes exceeding the desired range described herein. Furthermore, Comparative Examples EVOH 1 and 4 were prepared without using a fluoropolymer, and therefore did not exhibit particles.

[0064] Films were formed from each of Examples EVOH 1-10 and Comparative Examples EVOH 1-5 according to the same method as described in Example 3. The films were evaluated to determine film appearance, die deposition, Charpy impact strength, and elongation at break. Table 4 summarizes the properties of the films formed from Examples EVOH 1-10 and Comparative Examples EVOH 1-5.

[0065] [Table 4]

[0066] The appearance of the films formed from Examples EVOH 1 to 10 and Comparative Examples EVOH 1 to 5 was measured at 1 mm 2 If there are less than three fisheyes larger than 200 μm within a 1m 2 If there are 3 to 10 fisheyes larger than 200 μm within a range, it is expressed as "Δ" and 2If the number of fisheyes in the area was greater than 10 and larger than 200 μm, it was marked with an "X." The fisheye count test was performed using an FSA-100 designed with a charged coupled device (CCD) sensor and FSA-100 V.8 software. Also, if there was no deposit on the die, it was marked with an "O," and if there was deposit on the die, it was marked with an "X."

[0067] For Charpy impact strength, the specimens were conditioned for 16 hours at 50% ± 5% relative humidity and 23°C ± 2°C before testing using the ISO 179-1 method. The impact energy was 7.5 J, the impact direction was edgewise, the average specimen width was 10.06 mm, and the average specimen thickness was 3.94 mm. The notch depth was 8.09 mm, the test temperature was 23°C ± 2°C, and the fracture type was C.

[0068] For elongation at break, the test method was based on ISO 527-2, 2012 edition, and was performed at a temperature of 23°C, with a test speed of 50 mm / min, specimen type 1A, and an average specimen thickness of 3.99 mm.

[0069] The films of Examples EVOH 1 to 10 did not produce any deposition on the die and were 1 m 2 The number of fish eyes larger than 200 μm in the film was three or less. The Charpy impact strength of the films of Examples EVOH 1 to 10 was 2.45 to 6.9 KJ / m 2 The elongation at break of the films formed from Examples EVOH 1 to 10 was 17.8% to 24.3%.

[0070] The films of Comparative Examples EVOH 1, 2, and 4 exhibited precipitation on the die. A comparison of the film formed from Example EVOH 1 with the film formed from Comparative Example EVOH 1 showed that the addition of Example Fluoropolymer A improved the mechanical properties. Furthermore, a comparison of the films of Comparative Examples EVOH 1 and 2 with the films of Examples EVOH 1-4 showed that controlling the particle size within the specific ranges discussed herein significantly improved the Charpy impact strength and elongation at break. The films of Comparative Examples EVOH 3 and 5 did not exhibit precipitation on the die, but within these films, 1 m 2 There were more than 10 fish eyes with a size larger than 200 μm in the specimen.

[0071] Without being limited to any theory, the inventors believe that the presence of undesirable particle sizes in Comparative Examples EVOH 3 and 5 results in excessive coagulation and 2 However, when the particle size is controlled within the desired range, the film of the example EVOH not only exhibits better mechanical properties such as Charpy impact strength and elongation at break, but also better processability and film properties.

[0072] Comparisons were made to Examples EVOH 1, 3, 8, and 10-20 to evaluate the effect on EVOH of formulation with EVAC having different ethylene contents. Table 5 below summarizes some properties of Examples EVOH 1, 3, 8, and 10-20.

[0073] [Table 5]

[0074] The melting point temperature of EVOH was measured using a TA-Q200 differential scanning calorimeter (DSC, manufactured by TA Instruments) according to the method of ISO 11357-3 (2011), and the first and second melting points were measured in the first run of the differential scanning calorimeter.

[0075] Examples EVOH 1, 3, 8, and 10-20 all exhibited excellent dispersion of fluorine-containing particles. Furthermore, Examples EVOH 1, 3, 8, and 10-20 had particles with sizes and fluorine contents that met the desired ranges described herein. Examples EVOH 1, 3, 8, and 10-20 each had two melting points, with a first (lower) melting point temperature of 110°C to 125.2°C and a second (higher) melting point temperature of 158.7°C to 189.9°C. Surprisingly, regardless of the ethylene content, all of these Example EVOHs exhibited improved processability, and the EVOH films formed therefrom had improved mechanical properties. Without being limited to any particular theory, the inventors believe that when EVOH resins and pellets thereof contain particles containing fluoropolymers with a particle size of less than 20 μm, the processability and mechanical properties of the EVOH films formed therefrom can be improved. There was no direct relationship between the amount of Example Fluoropolymer A and the range of the fluorine content in the particles, nor was there a positive correlation.

[0076] Films were formed from Examples EVOH 1, 3, 8, 10, 11, and 12 using a method similar to that described in Example 3. The films were evaluated using the process and qualitative evaluation criteria described above to determine film appearance, die section precipitation, film Charpy impact strength, and film elongation at break. Table 6 below summarizes the film properties of Examples EVOH 1, 3, 8, 10, 11, and 12.

[0077] [Table 6]

[0078] The films of Examples EVOH 1, 3, 8, 10, 11 and 12 did not produce any deposition on the die, and the thickness of the film was 1 m. 2 The number of fish eyes larger than 200 μm in the film was less than three. The Charpy impact strength of the films of Examples EVOH 1, 3, 8, 10, 11 and 12 was 2.3 to 6.8 KJ / m 2 The elongation at break of the films of Examples EVOH 1, 3, 8, 10, 11 and 12 was in the range of 17.8% to 24.1%.

[0079] The effect of Example Fluoropolymers A to D on the formed EVOH was evaluated by comparing it to EVOH prepared with Example Fluoropolymers A to D. Table 7 below summarizes some properties of Examples EVOH 1, 11, and 21 to 27.

[0080] [Table 7]

[0081] Examples EVOH 1, 11, and 21 to 27 all exhibited excellent dispersibility of fluorine-containing particles. Furthermore, Examples EVOH 1, 11, and 21 to 27 had particles with sizes and fluorine contents that conformed to the desired ranges described herein. Examples EVOH 1, 11, and 21 to 27 each had two melting points, of which the first (lower) melting point was in the range of 113.7°C to 133.7°C and the second (higher) melting point was in the range of 180.9°C to 186.9°C.

[0082] Films were formed from Examples EVOH 1, 11, and 21-27 using a method similar to that described in Example 3. The films were evaluated using the process and qualitative evaluation criteria described above to determine film appearance, die-section precipitation, film Charpy impact strength, and film elongation at break. Table 8 summarizes the film properties of Examples EVOH 1, 11, and 21-27.

[0083] [Table 8]

[0084] The films formed from Examples EVOH 1, 11 and 21 to 27 did not produce any deposition on the die and were 1 mm thick. 2 The number of fish eyes larger than 200 μm in the film was less than three. The Charpy impact strength of the films of Examples EVOH 1, 11 and 21 to 27 was 2.45 to 3.3 KJ / m 2 The elongation at break of the films of Examples EVOH1, 11 and 21 to 27 was in the range of 17.8% to 22.4%. [Example]

[0085] Examples EVOH 1-4, 6, 8, 10, 12, 22-25, and 27-29 and Comparative Examples EVOH 1, 3, and 6 were prepared based on the process described in the above examples (e.g., Example 2). Films were prepared from each of Examples EVOH 1-4, 6, 8, 10, 12, 22-25, and 27-29 and Comparative Examples EVOH 1, 3, and 6 based on the method described in Example 3. Table 9 below summarizes several attributes of Examples EVOH 1-4, 6, 8, 10, 12, 22-25, and 27-29 and Comparative Examples EVOH 1, 3, and 6, namely, the ethylene content of the EVOH, the specific fluoropolymer contained in the EVOH pellets, and the fluoropolymer content.

[0086] [Table 9] [Example]

[0087] Evaluations were made on Examples EVOH 1 to 4, 6, 8, 10, 12, 22 to 25, and 27 to 29 and Comparative Examples EVOH 1, 3, and 6, and the melt pressure of the resin composition, Melting Several properties were determined, including strength, fluorine content, particle size range, particle dispersibility, and melting point temperature. Films of Examples EVOH 1-4, 6, 8, 10, 12, 22-25, and 27-29 and Comparative Examples EVOH 1, 3, and 6 were prepared according to the method described in Example 3.

[0088] The melt pressures of Examples EVOH 1 to 4, 6, 8, 10, 12, 22 to 25, and 27 to 29 and Comparative Examples EVOH 1, 3, and 6 Melting The force was measured for each sample. Specifically, samples of Examples EVOH 1-4, 6, 8, 10, 12, 22-25, and 27-29 and Comparative Examples EVOH 1, 3, and 6 were placed in a Malvern Instruments RH7 Flowmaster twin-bore capillary rheometer. A long die (inner diameter: 1 mm, length: 20 mm) was attached to the test side of the RH7 Flowmaster twin-bore capillary rheometer, and a zero die (inner diameter: 1 mm, length: 0.25 mm) was attached to the blank side. The RH7 Flowmaster twin-bore capillary rheometer had a bore diameter of 15 mm and was equipped with an Ultra-MAX-HT pressure sensor (model number: UMHT3-6-MX-18-D8-30M-B). Rosand Rheometer Control Software (version 8.6) was used as the software platform. The RH7 Flowmaster twin-bore capillary rheometer has a maximum load of 50kN.

[0089] Before adding the pellets, the RH7 Flowmaster twin-bore capillary rheometer was held at a temperature of 190°C for 30 minutes. Before the test began, the pellets were compressed at a moderate speed to expel air from the material, and then allowed to dissolve in the two bores of the RH7 Flowmaster twin-bore capillary rheometer for 9 minutes. The shear rate range for the test was approximately 10 to approximately 10,000 (s). -1 ) was decided.

[0090] Table 10 below compares the properties of Examples EVOH 1 to 4, 6, 8, 10, 12, 22 to 25, and 27 to 29 and Comparative Examples EVOH 1, 3, and 6. The fluorine content, particle size range, particle dispersibility, and melting point temperature were measured according to the methods described in Examples 2 to 4.

[0091] [Table 10]

[0092] The EVOHs of Examples 1 to 4, 6, 8, 10, 12, 22 to 25, and 27 to 29 all exhibited excellent dispersibility, while the EVOHs of Comparative Examples exhibited somewhat poor dispersibility. As described above, when the EVOH resin composition contained one or more particles with a particle size larger than 20 μm or when no particles were formed, the result was indicated by "X." When the particles of the EVOH resin composition were not coagulated and excellent dispersibility was exhibited, the result was indicated by "O."

[0093] Films were formed from Examples EVOH 1-4, 6, 8, 10, 12, 22-25, and 27-29 and Comparative Examples EVOH 1, 3, and 6 using methods similar to those described in the above examples (e.g., Example 3). The films were also evaluated using the above-described process and qualitative evaluation criteria to determine film appearance, die-section precipitation, Charpy impact strength, and elongation at break. Table 11 below summarizes the film properties of Examples EVOH 1-4, 6, 8, 10, 12, 22-25, and 27-29 and Comparative Examples EVOH 1, 3, and 6.

[0094] [Table 11]

[0095] Surprisingly, the melt pressure of the EVOH resin composition of the present invention is -1 When the pressure is in the range of 1.7 to 7.0 MPa at a temperature of 190°C, the film does not deposit on the die and is thicker than 1 m. 2 As described above, in Examples EVOH 1 to 4, 6, 8, 10, 12, 22 to 25 and 27 to 29, no deposition occurred on the die, and the number of fish eyes larger than 200 μm was 3 or less. 2The number of fish eyes larger than 200 μm in the film was three or less. The Charpy impact strength of the films of Examples EVOH 1 to 4, 6, 8, 10, 12, 22 to 25 and 27 to 29 was 2.3 to 6.8 KJ / m 2 The elongation at break of the films of Examples EVOH 1 to 4, 6, 8, 10, 12, 22 to 25 and 27 to 29 was within the range of 17.8% to 23.9%.

[0096] In Comparative Examples 1 and 6, where the melt pressure exceeded the desired range, precipitation occurred on the die and plasticity was poor. As mentioned above, in the presence of a fluoropolymer, a reduction in melt pressure indicates smoother flow behavior of EVOH in the screw extruder, and the protection of the fluoropolymer on the inner wall of the screw extruder reduces precipitation on the die and improves the appearance of the film.

[0097] With regard to the fluoropolymer present in the EVOH resin composition, if the fluorine content is too high, the EVOH resin composition may have an undesirable melt pressure, which may result in poor film appearance.

[0098] All ranges provided herein are intended to include each specific range within the assigned range and any combination of subranges between the assigned ranges. Also, unless otherwise specified, all ranges provided herein include the endpoints of the range. Thus, the range 1-5 specifically includes 1, 2, 3, 4, and 5, as well as subranges such as 2-5, 3-5, 2-3, 2-4, and 1-4.

[0099] All publications and patent applications referenced in this specification are hereby incorporated by reference and are specifically and individually indicated to be incorporated by reference into each and every publication or patent application for all purposes. In the event of a conflict between this specification and any publication or patent application incorporated by reference herein, the specification controls.

[0100] As used herein, the terms "comprise," "have," and "include" have an open, non-limiting meaning. The terms "a" and "the" should be understood to include the plural and the singular. The term "one or more" refers to "at least one" and can therefore include a single feature or a mixture / combination of features.

[0101] Except in the operating examples or where otherwise indicated, all numbers indicating quantities of ingredients and / or reaction conditions can in all instances be modified by the term "about" to mean within ±5% of the indicated number. As used herein, the terms "essentially free" or "substantially free" mean less than about 2% of a particular characteristic. Any element or characteristic explicitly recited in this specification can be negatively excluded from the claims. [Explanation of symbols]

[0102] 100 EVOH resin composition 110 Fluorine-containing particles 120 coating layers

Claims

1. an ethylene vinyl alcohol copolymer; one or more fluorine-containing particles, the one or more fluorine-containing particles comprise a fluorinated polymer; Shear rate 20 s －１ and has a melting pressure of 1.7 to 7.0 MPa at a temperature of 190°C; An ethylene-vinyl alcohol copolymer resin composition comprising at least two melting temperatures, a first melting temperature and a second melting temperature, wherein the first melting temperature is 110°C to 140°C and the second melting temperature is 150°C to 195°C.

2. Shear rate 20 s －１ 2. The ethylene-vinyl alcohol copolymer resin composition according to claim 1, having a melting pressure of 1.7 to 6.8 MPa at a temperature of 190°C.

3. Shear rate 20 s －１ 3. The ethylene-vinyl alcohol copolymer resin composition according to claim 1, wherein the ethylene-vinyl alcohol copolymer resin composition has a melting force of 0.04 to 2.4 kN at a temperature of 190°C.

4. 4. The ethylene-vinyl alcohol copolymer resin composition according to claim 1, wherein each of the fluorine-containing particles has a diameter or a major axis length of less than 20 μm.

5. 5. The ethylene-vinyl alcohol copolymer resin composition according to claim 1, wherein the fluorine-containing particles have a fluorine content of 1.5 to 48 wt %, the fluorine content being based on the total weight of carbon, oxygen, and fluorine elements.

6. 6. The ethylene-vinyl alcohol copolymer resin composition according to claim 1, wherein each of the fluorine-containing particles has a particle diameter or a major axis length of 0.5 to 19 μm.

7. The ethylene-vinyl alcohol copolymer resin composition according to any one of claims 1 to 6 has a Charpy impact strength according to ISO 179-1 of at least 2.3 KJ / m at 23°C. ２ and the elongation at break according to ISO 527-2 is at least 17.8% at 23°C.

8. 8. The film of claim 7, wherein the film has an elongation at break of at least 20%.

9. (a) at least one layer formed from the ethylene-vinyl alcohol copolymer resin composition according to any one of claims 1 to 6; (b) at least one polymer layer; (c) at least one adhesive layer.

10. 10. The multilayer structure of claim 9, wherein the polymer layer is selected from the group consisting of a low density polyethylene layer, a polyethylene grafted maleic anhydride layer, a polypropylene layer, a nylon layer, and combinations thereof.

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