BR102020026505B1 - COMPOSITION OF ETHYLENE-VINYL ALCOHOL COPOLYMER RESIN, FILM AND MULTILAYER STRUCTURE - Google Patents

Abstract

COMPOSITION OF ETHYLENE-VINYL ALCOHOL COPOLYMER RESIN, FILM AND MULTILAYER STRUCTURE. The present invention relates to an ethylene-vinyl alcohol copolymer resin composition and/or pellets thereof including one or more fluorine-containing particles. The ethylene-vinyl alcohol copolymer resin composition and/or pellets thereof may have a boron content of 10 to 450 ppm. EVOH film formed from EVOH may have a Charpy shock resistance of at least 2.5 kJ/m2 according to ISO 179-1 at 23°C and an elongation at break of at least 18.2% according to ISO 527-2 at 23°C.

Description

Field of disclosure

[0001] The present disclosure relates to the ethylene-vinyl alcohol (“EVOH”) copolymer resin composition and pellets thereof. The ethylene-vinyl alcohol copolymer resin composition has particles and, in particular, fluorine-containing particles. The EVOH resin composition may have a boron content of 10 to 450 ppm. Films and multilayer structures formed from the ethylene-vinyl alcohol copolymer resin composition and/or pellets are also disclosed herein.

Disclosure history

[0002] EVOH resins are widely used in laminates to preserve perishable items. For example, EVOH resins and laminates are commonly used by the food packaging industry, medical devices and supplies industry, pharmaceutical industry, electronics industry, and agricultural chemicals industry. EVOH resins are often incorporated as a distinct layer within a laminate to serve as an oxygen barrier layer.

[0003] Unsatisfactory film thickness uniformity is a common problem with EVOH films, which can reduce the gas barrier properties and mechanical properties of such EVOH films. Furthermore, the flexibility and mechanical properties of typical EVOH films are insufficient for wider application and practical use of EVOH films. These problems have not been sufficiently addressed or resolved with conventional technology.

[0004] Thus, there is a continued need for EVOH resins that provide improved film flexibility, mechanical properties and film thickness uniformity.

Summary of the invention

[0005] Aspects of the disclosure are directed to the ethylene-vinyl alcohol copolymer ("EVOH") resin composition having particles and, in particular, fluorine-containing particles. The EVOH resin composition may be in the form of pellets, films, fibers and/or the like. The EVOH resin composition can be used to produce multilayer films or structures. It has been common sense to avoid the combination of EVOH and fluorinated polymers due to their immiscibility. For example, the immiscibility of EVOH and fluorinated polymers was expected to adversely affect the appearance and mechanical properties of films formed from them.

[0006] Although the combination of EVOH and fluorinated polymers (also referred to herein as “fluoropolymers”) has traditionally been avoided due to problems arising from immiscibility, aspects of the disclosure utilize fluorinated polymers that are partially miscible (and partially immiscible) to produce EVOH resin composition having improved precipitation in the matrix and reduced spindle adhesion problems. Additionally, it has been discovered that the EVOH resin composition disclosed herein can provide improved flexibility and increased mechanical properties for films and multilayer structures formed therefrom. Specifically, using EVOH resin composition having fluorine-containing particles, the inventors have understood that EVOH films can be obtained having improved strength (e.g., measured by Charpy impact test) and improved flexibility (e.g., measured by elongation at break).

[0007] In additional aspects of the disclosure, there is provided EVOH resin composition (or pellets thereof) having fluorine-containing particles and a boron content of 10 to 450 ppm. In some cases, a typical EVOH resin composition may comprise an ethylene-vinyl alcohol copolymer, one or more fluorine-containing particles and a boron compound, where the ethylene-vinyl alcohol copolymer resin composition has a boron content of 10 to 450 ppm. Without being limited to any specific theory, it is believed that the addition of a boron compound to the EVOH resin composition having fluorine-containing particles, so that the boron content of the EVOH resin composition is 10 to 450 ppm, reduces or eliminates adhesion of the EVOH resin composition during extrusion through a screw extruder (screw). Surprisingly, it was found that boron content in a certain range can further improve film thickness uniformity and also improve flexibility. In some cases, such EVOH resin compositions can clean the screw extruder during the extrusion process by removing or at least partially removing EVOH resin previously adhered to the internal surfaces of the screw extruder.

[0008] The EVOH resin composition may also include one or more particles comprising a fluorinated polymer. Preferably, each of the fluorine-containing particles has a particle size with a diameter or long axis length of less than or equal to 20 μm. In some cases, each of the fluorine-containing particles has a diameter or a major axis length that is from 0.5 to about 19 μm. The containing particles may comprise from about 1.5 to about 48% by weight of fluorine, based on the total weight of the elements carbon, oxygen and fluorine. Surprisingly, it was found that particle size in certain ranges can further improve film appearance and matrix precipitation.

[0009] In a non-limiting example, the EVOH resin composition has at least two melting point temperatures — in other words, at least one first melting point temperature and a second melting point temperature. The first melting point temperature may be from about 100°C to about 140°C or from 105°C to 135°C. The second melting point temperature may be from about 150°C to about 195°C or from 158°C to 190°C.

[0010] Additionally or alternatively, the ethylene-vinyl alcohol copolymer of the EVOH resin composition may have a degree of saponification greater than or equal to 99.5 mol%. The ethylene-vinyl alcohol copolymer can have an ethylene content of about 20 to about 50 mole %. For example, the ethylene content of the ethylene-vinyl alcohol copolymer can be from about 25 to about 45 mole %. In some cases, the EVOH resin composition is free of polyalkylene oxides.

[0011] Preferably, the fluorine-containing particles of the EVOH resin composition may have a particle size of about 0.5 to about 19 μm. For example, the particle size of fluorine-containing particles can be from about 1.2 to about 16 μm.

[0012] According to at least one embodiment, the EVOH resin composition comprises: an ethylene-vinyl alcohol copolymer comprising an ethylene content of about 20 to about 50 mol% and having a degree of saponification greater than or equal to 99.5 mol%; at least two melting point temperatures, a first melting point temperature of about 100°C to about 140°C and a second melting point temperature of about 150°C to about 195°C; fluorine-containing particles dispersed in the EVOH resin composition; and a boron content of 10 to 450 ppm.

[0013] Films formed from the EVOH resin composition typically have a Charpy shock resistance of at least 2.5 kJ/m2 (e.g. according to ISO 179-1 at 23°C) and a percentage of elongation at break of at least 18.2% (according to ISO 527-2 at 23°C). Preferably, the film has a Charpy shock resistance of at least 2.6 kJ/m2. In some cases, the film may have an elongation at break percentage of at least 20%. It was surprising that the EVOH resin composition having the fluorine-containing particles described herein would provide advantageous improvements in the strength and flexibility of films formed from such pellets of the EVOH resin composition.

Brief description of the figures

[0014] The implementation of the present technology will now be described, by way of example only, with reference to the attached figures, in which:

[0015] FIG. 1 is a cross-sectional representation of an exemplary EVOH resin composition in accordance with aspects of the disclosure;

[0016] FIG. 2 is a graph of the two melting point temperatures of an exemplary EVOH resin composition in accordance with aspects of the disclosure; It is

[0017] FIG. 3 is a cross-sectional representation of an extruder with cast EVOH resin compositions in accordance with aspects of the disclosure flowing therethrough.

[0018] It should be understood that the various aspects are not limited to the arrangements, instrumentality and characteristics shown in the figures.

Detailed description of the disclosure

[0019] Aspects of the disclosure are directed to the ethylene-vinyl alcohol copolymer (“EVOH”) resin composition. The EVOH resin composition has particles, in particular, fluorine-containing particles dispersed therein. The EVOH resin composition can be used to produce multilayer films or structures.

[0020] According to one aspect of the disclosure, an EVOH resin composition is provided. The EVOH resin composition may be in the form of pellets, films, fibers and/or the like. When used herein, EVOH pellets refer to an EVOH resin composition that has been pelletized to be in the form or configuration of one or more pellets. Although an EVOH resin composition pelletized to be in the form of one or more EVOH pellets is described throughout the present disclosure, the EVOH resin composition may be processed to be in the form of beads, cubes, chips, shavings, or the like. The EVOH resin composition of the present disclosure typically includes an ethylene-vinyl alcohol copolymer and one or more fluorine-containing particles having a particle size less than or equal to 20 μm.

[0021] FIG. 1 represents a cross section of an EVOH 100 resin composition in accordance with aspects of the disclosure. The EVOH 100 resin composition is formed from an EVOH having an ethylene content. For example, EVOH may have an ethylene content of from about 20 to about 50 mole %, from about 25 to about 45 mole %, from about 28 to about 42 mole %, or from about 30 to about 42 mole percent. about 40% mole. The EVOH 100 resin composition can be formed from two or two EVOHs having different ethylene contents. For example, one of the EVOH may have an ethylene content in the range of about 20 to about 35 mole %, such as from about 24 to about 35 mole %, from about 28 to about 35 mole %, from about 20 to about 32 mole%, from about 24 to about 32 mole%, from about 28 to about 32 mole%, from about 20 to about 30 mole%, or from about 24 to about of 30 mol%. Additionally or alternatively, one of the EVOH may have an ethylene content in the range of from about 36 to about 50 mole %, such as from about 40 to about 50 mole %, from about 44 to about 50 mole %, from about 36 to about 45 mole %, or from about 40 to about 45 mole %. However, in some preferred cases, the EVOH 100 resin composition is formed from a single EVOH having an ethylene content of about 20 to about 50 mole %.

[0022] The EVOH 100 resin composition has an amount of fluorine associated with the incorporation of one or more fluorinated polymers, which can form fluorine-containing particles 110 dispersed in the EVOH 100 resin composition. For example, the one or more fluorinated polymers can include or be chosen from polyvinylidene fluoride (“PVDF”), polytetrafluoroethylene, polyhexafluoroethylene, polychlorotrifluoroethylene, 2-chloro-pentafluoroethylene, dichlorodifluoroethylene , 1,1-dichloro-fluoro-ethylene and/or combinations thereof. Additionally or alternatively, the fluorinated polymer (or fluoropolymer) may include copolymers derived from at least one of vinylidene fluoride ("VDF"), hexafluoropropylene ("HFP") and tetrafluoroethylene ("TFE"). In some cases, the fluorinated polymer may include copolymers derived from one or more of VDF, HFP and TFE. For example, the EVOH 100 resin composition 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. While not limited to any specific theory, the inventors believe that fluorinated polymers can reduce at least one of the melting points of the EVOH 100 resin composition producing a reduction in crystalline size, which reduces energy requirements during processing.

[0023] Fluorine-containing particles 110 may have from about 1.5 to about 48 weight percent (wt%) fluorine, based on the total weight of carbon, oxygen and fluorine elements of the fluorine-containing particles 110. particles containing fluorine 110 may in other cases have from about 1.5 to about 47% by weight fluorine or from about 1.8 to about 44% by weight fluorine or from about 2.1 to about 41% by weight fluorine, based on the total weight of carbon, oxygen and fluorine elements of the fluorine 110-containing particles.

[0024] The fluorine-containing particles 110 of the EVOH 100 resin composition may be in the form of microparticles. According to the International Union of Pure and Applied Chemistry (IUPAC) definition, a microparticle is 10-7 to 10-4 m in size. In the present invention, each fluorine-containing particle 110 may have a particle size with a diameter or with a length from the major (major) axis through a cross-sectional area of 0.3 to about 19 μm, of 0.3 to about 18 μm, from 0.5 to about 19 μm, from 1.0 to about 19 μm, or preferably from 1.2 to about 16 μm. The size of the fluorine-containing particles can be controlled by controlling the type or species of fluorinated polymer, the amount of fluorinated polymer, and the ethylene content of the EVOH copolymer. If the fluorine-containing particle is a sphere, the diameter of a cross-sectional area of the fluorine-containing particle will be used to determine whether the fluorine-containing particle has a desirable particle size. In a case where the fluorine-containing particle is not a sphere and/or the cross-section of the fluorine-containing particle has a shape other than a circle, such as an ellipse or cluster, the length of the long axis of the cross-sectional area of the fluorine-containing particle is used. to determine whether the fluorine-containing particle has a desirable particle size. The definition of major (main) axis is the axis with the maximum length. In some cases, all particles containing fluorine 110, as evaluated over a cross section of an EVOH 100 resin composition, have a particle size less than or equal to 20 μm, such as less than or equal to 19 μm, less than or equal to 18 μ m, less than or equal to 16 μ m, less than or equal to 14 μ m or less than or equal to 12 μ m. In other words, none of the fluorine-containing particles 110 te, a particle size greater than 20 μ m, such as greater than 19 μ m, greater than 18 μ m, greater than 16 μ m, greater than 14 μ m, or greater than 12μm. Particles containing fluorine 110 may have a particle size greater than or equal to 0.1 μm, greater than or equal to 0.3 μm, greater than or equal to 0.5 μm, or greater than or equal to 0.7 μm . For example, the EVOH 100 resin composition may have fluorine-containing particles 110 having a size of 1.0 to about 19 μm or 1.2 to about 16 μm. In some cases, all of the fluorine-containing particles 110 when evaluated across a cross section of an EVOH 100 resin composition are within the desired particle ranges discussed herein. However, in some cases, the majority of fluorine 110-containing particles, when evaluated across a cross section of an EVOH 100 resin composition, are within the desired particle ranges. Exemplary procedures for determining particle size within the desired range may include: (a) the amount of fluoropolymer, (b) the ethylene content of EVOH, (c) the type of fluoropolymer, (d) the temperature in the extruder and (e) the rotational frequency of the spindle.

[0025] As illustrated by FIG. 2, the EVOH 100 resin composition may have at least two melting point temperatures. In some cases, one (e.g., a first) of the melting point temperatures of the EVOH 100 resin composition is from about 100°C to about 140°C - e.g., from about 105°C to about 135°C, from about 110°C to about 135°C or from about 120°C to about 130°C. Additionally or alternatively, one (e.g., a second) of the melting point temperatures of the EVOH 100 resin composition may be from about 150°C to about 195°C - e.g., from about 158°C to about from 190°C, or from about 164°C to about 187°C. In some cases, the EVOH 100 resin composition has at least three different melting point temperatures. In other cases, the EVOH 100 resin composition includes at least four, at least five, or at least six different melting point temperatures. Additionally and/or alternatively, the EVOH 100 resin composition may have a degree of saponification greater than or equal to 90 mol%, preferably greater than or equal to 95 mol%, preferably greater than or equal to 97 mol%, preferably greater than or equal to 99 .5 mole%.

[0026] The EVOH 100 resin composition or pellets thereof may be free or partially free of poly(alkylene oxides). For example, the EVOH 100 resin composition may be less than 5% by weight, such as less than 4% by weight, less than 3% by weight, less than 2% by weight, less than 1% by weight, or less than 0.5% by weight poly(alkylene oxides).

[0027] Advantageously, the EVOH 100 resin composition allows more efficient manufacturing of EVOH films formed from it. For example, EVOH 100 resin composition can improve precipitation in the die and reduce spindle adhesion problems during the manufacture of EVOH films. Equipment and processes suitable for manufacturing EVOH films may include those already known to one skilled in the art. Using fluorinated polymers that are partially miscible (and partially immiscible) and producing EVOH 100 resin composition containing fluorine-containing particles 110, the inventors believe that a portion of the fluorinated polymers segregates and forms a coating layer 120 on the inner surface of the extruder. FIG. 3 depicts the formation of a coating layer 120 on the inner surface of an extruder by a portion of fluorinated polymers and an EVOH pellet disclosed herein. Additionally, EVOH pellets can advantageously allow the extrusion process to occur at increased temperatures without discoloring the produced EVOH film, since the fluorinated polymer coating layer on the inner wall of the extruder can protect the EVOH resin flowing through of the extruder.

[0028] By adding the fluorinated polymer, it can help the EVOH resin composition during spindle processing. In particular, the fluorinated polymer attaches to the inner wall of the screw extruder, which reduces the flow resistance of the EVOH resin composition through the screw extruder and reduces precipitation in the die.

[0029] A typical EVOH resin composition may comprise an ethylene-vinyl alcohol copolymer, and one or more fluorine-containing particles, with the ethylene-vinyl alcohol resin composition having a melting pressure of 1.7 to 7. 0 MPa at a shear rate of 20 s-1 and a temperature of 190°C. The melting pressure of the EVOH resin composition can range from 1.7 to about 7.0 MPa, from 1.7 to about 6.8 MPa, from 1.7 to about 6.5, from 1.7 to about from 6.2 MPa, from 1.7 to about 5.9 MPa, from 1.7 to about 5.6 MPa; from about 2 to about 6.8 MPa, from about 2 to about 6.5 MPa, from about 2 to about 6.2 MPa, from about 2 to about 5.9 MPa, from about from 2 to about 5.6 MPa; from about 2.3 to about 6.8 MPa, from about 2.3 to about 6.5 MPa, from about 2.3 to about 6.2.3 MPa, from about 2.3 to about 5.9 MPa, from about 2.3 to about 5.6 MPa; from about 2.6 to about 6.8 MPa, from about 2.6 to about 6.5 MPa, from about 2.6 to about 6.2.6 MPa, from about 2.6 to about 5.9 MPa, from about 2.6 to about 5.6 MPa; from about 2.9 to about 6.8 MPa, from about 2.9 to about 6.5 MPa, from about 2.9 to about 6.2.9 MPa, from about 2.9 to about 5.9 MPa, from about 2.9 to about 5.6 MPa; from about 3.2 to about 6.8 MPa, from about 3.2 to about 6.5 MPa, from about 3.2 to about 6.3.2 MPa, from about 3.2 to about 5.9 MPa, from about 3.2 to about 5.6 MPa; from about 3.9 to about 6.8 MPa, from about 3.9 to about 6.5 MPa, from about 3.9 to about 6.3.9 MPa, from about 3.9 to about 5.9 MPa, from about 3.9 to about 5.6 MPa; from about 4.2 to about 6.8 MPa, from about 4.2 to about 6.5 MPa, from about 4.2 to about 6.4.2 MPa, from about 4.2 at about 5.9 MPa or from about 4.2 to about 5.6 MPa, at a shear rate of 20 s-1 and a temperature of 190°C. In addition to a melting pressure of 1.7 to 7.0 MPa, the EVOH resin composition may, in some cases, contain a boron compound and/or boron acid and/or cinnamic acid and/or alkali metal and/or or conjugated polyene and/or lubricant and/or alkaline earth metal. The substances described above can lead to improved properties in EVOH resin composition.

[0030] The EVOH resin composition can have a melt strength of about 0.04 to about 2.4 kN at a shear rate of 20 s-1 and a temperature of 190°C. For example, the fusion force may be from about 0.04 to about 2.4 kN, from about 0.04 to about 2.0 kN, from about 0.04 to about 1.7 kN , from about 0.04 to about 1.4 kN, from about 0.04 to about 1.1 kN, from about 0.04 to about 1.0 kN, from about 0.04 to about about 0.8 kN; from about 0.06 to about 2.4 kN, from about 0.06 to about 2.0 kN, from about 0.06 to about 1.7 kN, from about 0.06 to about from 1.4 kN, from about 0.06 to about 1.1 kN, from about 0.06 to about 1.0 kN, from about 0.06 to about 0.8 kN; from about 0.08 to about 2.4 kN, from about 0.08 to about 2.0 kN, from about 0.08 to about 1.7 kN, from about 0.08 to about from 1.4 kN, from about 0.08 to about 1.1 kN, from about 0.08 to about 1.0 kN; from about 0.1 to about 2.4 kN, from about 0.1 to about 2.0 kN, from about 0.1 to about 1.7 kN, from about 0.1 to about of 1.4 kN, from about 0.1 to about 1.1 kN at a shear rate of 20 s-1 and a temperature of 190°C.

[0031] According to one aspect of the disclosure, there is provided an EVOH resin composition having fluorine-containing particles and a boron content of 10 to 450 ppm. Without being limited to any specific theory, it is believed that the addition of a boron compound to the EVOH resin composition having fluorine-containing particles, such that the boron content of the EVOH is 10 to 450 ppm, reduces or eliminates the adhesion of the EVOH resin composition during extrusion through a screw extruder and further improves film flexibility and thickness uniformity. In some cases, such EVOH resin compositions can clean the screw extruder during the extrusion process by removing or at least partially removing EVOH resin previously adhered to the internal surfaces of the screw extruder.

[0032] A typical EVOH resin composition may comprise an ethylene-vinyl alcohol copolymer, one or more fluorine-containing particles and a boron compound, where the ethylene-vinyl alcohol copolymer resin composition has a boron content of 10 at 450 ppm. In some cases, the resin composition may have a boron content of 10 to about 450 ppm, 10 to about 400 ppm, 10 to about 350 ppm, 10 to about 300 ppm, 10 to about 275 ppm, from 10 to about 250 ppm, from 10 to about 225 ppm, from 10 to about 200 ppm, from 10 to about 175 ppm; from about 20 to about 450 ppm, from about 20 to about 400 ppm, from about 20 to about 350 ppm, from about 20 to about 300 ppm, from about 20 to about 275 ppm, from about from about 20 to about 250 ppm, from about 20 to about 225 ppm, from about 20 to about 200 ppm, from about 20 to about 175 ppm; from about 60 to about 450 ppm, from about 60 to about 400 ppm, from about 60 to about 350 ppm, from about 60 to about 300 ppm, from about 60 to about 275 ppm, from about from about 60 to about 250 ppm, from about 60 to about 225 ppm, from about 60 to about 200 ppm, from about 60 to about 175 ppm; from about 100 to about 450 ppm, from about 100 to about 400 ppm, ppm, from about 100 to about 350 ppm, from about 100 to about 300 ppm, from about 100 to about 275 ppm, from about 100 to about 250 ppm, from about 100 to about 225 ppm, from about 100 to about 200 ppm, from about 100 to about 175 ppm; from about 140 to about 450 ppm, from about 140 to about 400 ppm, from about 140 to about 350 ppm, from about 140 to about 300 ppm, from about 140 to about 275 ppm, from about from 140 to about 250 ppm, from about 140 to about 225 ppm, from about 140 to about 200 ppm; from about 180 to about 450 ppm, from about 180 to about 400 ppm, from about 180 to about 350 ppm, from about 180 to about 300 ppm, from about 180 to about 275 ppm, from about from 180 to about 250 ppm, from about 180 to about 225 ppm; from about 220 to about 450 ppm, from about 220 to about 400 ppm, from about 220 to about 350 ppm, from about 220 to about 300 ppm, from about 220 to about 275 ppm, based on total weight of the EVOH resin composition. When the boron content of the EVOH resin composition is within a certain range, it may increase the viscosity of the EVOH resin composition and reduce the chance of the EVOH resin composition adhering to the spindle, or remove the EVOH in the spindle, so that the material has a self-cleaning function, which also improves film thickness uniformity. Surprisingly, the inventors have discovered that while the EVOH 100 resin composition of the present disclosure, which contains the fluorine-containing particles 110, has the desired ranges of boron content, the processability, mechanical properties, and film thickness uniformity are improved. . In addition to a boron content of 10 to 450 ppm, the EVOH resin composition may, in some cases, contain cinnamic acid, alkali metal, conjugated polyene, lubricant, alkaline earth metal, salts thereof and/or mixtures thereof. The substances described above are common substances usually present in the composition of EVOH resin leading to better properties. When the content of conjugated polyene in the EVOH resin composition per unit weight is 1 to 30,000 ppm, coloring after heating can still be suppressed and thermal stability can be improved. When the lubricant content in the EVOH resin composition per unit weight is 1 to 300 ppm, the processability can be improved.

[0033] In one aspect of the present invention, the boron content is controlled to be within the limits of a specific range with the presence of a fluorinated polymer. In addition to improving the flexibility and processing characteristics of EVOH, it can also improve the appearance characteristics of the final product.

[0034] Boron compounds may, in some cases, include boric acid or a metallic salt thereof. Examples of the metal salt include, but are not limited to, calcium borate, cobalt borate, zinc borate (e.g., zinc tetraborate, zinc metaborate, potassium aluminum borate, ammonium borate (e.g., zinc metaborate). ammonium, 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), silver borate (e.g. silver metaborate, silver tetraborate), copper borate (e.g. copper(II) borate, copper metaborate, copper tetraborate), sodium borate (e.g. , sodium metaborate, sodium diborate, sodium tetraborate, sodium pentaborate, sodium hexaborate, sodium octaborate), lead borate (e.g. lead metaborate, lead hexaborate), nickel borate (e.g. orthoborate nickel borate, nickel diborate, nickel tetraborate, nickel octaborate), barium borate (e.g. barium orthoborate, barium metaborate, barium diborate, barium tetraborate), bismuth borate, magnesium borate (e.g. , magnesium orthoborate, magnesium diborate, magnesium metaborate, trimagnesium tetraborate, pentamagnesium tetraborate), manganese borate (e.g. manganese(I) borate, manganese metaborate, manganese tetraborate), lithium borate (e.g. example, lithium metaborate, lithium tetraborate, lithium pentaborate), salts thereof, or combinations thereof. Borate minerals such as borax, kainite, inioite, cotoite, swanite and szaibellite may be included. Of these, borax, sodium tetraborate, sodium pentaborate, sodium hexaborate and sodium octaborate are preferably used.

[0035] According to another aspect of the disclosure, there is provided an EVOH film formed from the EVOH 100 resin composition. The EVOH film has a Charpy shock resistance of at least 2.3 kJ/m2 according to ISO 179-1 at a temperature of 23°C and an elongation at break of at least 17.8% according to ISO 527-2 at a temperature of 23°C. For some embodiments, the EVOH film may have a Charpy shock resistance of at least 2.3 kJ/m2, at least 3 kJ/m2, at least 4.5 kJ/m2, at least 5 .5 kJ/m2, or at least 6.5 kJ/m2 according to ISO 179-1 at a temperature of 23°C. To obtain the above impact (shock) resistance values, specimens must be maintained at a relative humidity of 50% ± 5% and a temperature of 25°C ± 2°C for 16 hours before being tested using the procedure of ISO 179-1. Additionally, the impact energy must be adjusted to 7.5 J, the impact direction must be profile, the sample type must be 1 eA, the average sample width must be 10.06 mm and the average thickness of the sample must be 3.94 mm. The notch depth for the test shall be 8.09 mm, the test temperature shall be 23°C ± 2°C, and the fracture type shall be C. The EVOH film may have an elongation percentage at rupture of at least 18% according to ISO 527-2 at a temperature of 23°C. In some cases, the EVOH film may have an elongation at break percentage of at least 20%, at least 21%, at least 23% or at least 24% in accordance with ISO 5272 at a temperature of 23°C. . To obtain the above values for elongation at break, the test method edition must be 2012, the test speed 50 mm/min, the sample type must be 1A, and the average sample thickness must be 3. 99mm.

[0036] According to yet another aspect of the disclosure, there is provided a multilayer structure having at least one layer formed by the EVOH resin composition disclosed herein; at least one polymeric layer; and at least one adhesive layer. The polymeric layer can be chosen from a low-density polyethylene layer, a maleic anhydride-grafted polyethylene layer, a polypropylene layer, a nylon layer, and a combination thereof. The adhesive layer may be a bonding layer. The bonding layer can be, for example, ARKEMA OREVAC 18729, which is obtainable from ARKEMA.

Examples

[0037] The following non-limiting examples of aspects of the invention are provided mainly for the purpose of elucidating aspects of the invention and the benefits derived therefrom.

Example 1

[0038] Four fluorinated polymers (Fluorinated Polymers Examples A-D) were prepared in accordance with aspects of the disclosure. Fluorinated Polymers Examples A-D were subsequently used to produce ethylene-vinyl alcohol (“EVOH”) copolymer resin composition in accordance with the present disclosure. Although Fluorinated Polymers Examples A-D were prepared according to the specific process disclosed below, other types of fluorinated polymers can be used for addition with EVOH.

Fluorinated Polymer Example A

[0039] Fluorinated Polymer Example A was produced using an autoclave as a batch reactor. The autoclave had an internal volume of about 20 liters and was equipped with an electromagnetic induction stirrer. The autoclave was sufficiently cleaned with nitrogen gas (N2) and was subsequently charged five times with nitrogen gas at reduced pressure.

[0040] During the application of reduced pressure inside the autoclave, 6,960 g of pure deoxygenated water, 3,204 g of 1,1,2-trichloro-1,2,2-trifluoroethane and 3.5 g of methyl cellulose in the autoclave. Methyl cellulose had a viscosity of 50 cP and was stirred into the composition within the autoclave at 450 rpm to act as a suspension stabilizer. The composition inside the autoclave was maintained at a temperature of 52°C.

[0041] A monomer composed of 25.3% by weight of vinylidene fluoride (VDF), 68.6% by weight of hexafluoropropylene (HFP), 6.1% by weight of tetrafluoroethylene was mixed into the batch. (TFE) as a carrier gas, and charged at 10 kg/cm2. Subsequently, 45.6 g of a solution of about 90% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane and 10% by weight of diisopropyl peroxydicarbonate was charged as a catalyst to start polymerization. Diisopropyl peroxydicarbonate acted as an initiator to initiate polymerization. As the pressure is reduced during the polymerization reaction a mixed monomer having 44.7 wt% VDF, 32.5 wt% HFP and 22.8 wt% TFE is added to increase the pressure back to 10 kg/cm2. After completion of the polymerization reaction, the remaining mixed monomer was cleaned up, and the resulting suspension was dehydrated with a centrifugal separator, washed with deionized (DI) water, and then vacuum dried at 100°C to obtain about 7.5 kg of Fluorinated Polymer Example A.

Fluorinated Polymer Example B

[0042] Fluorinated Polymer Example B was produced using a similar and adjusted autoclave as used to produce Fluorinated Polymer Example A. The autoclave was also repeatedly charged five times with N2 and reduced pressure.

[0043] During the application of reduced pressure inside the autoclave, 7,200 g of pure deoxygenated water, 3,250 g of 1,1,2-trichloro-1,2,2-trifluoroethane and 4 g of methyl cellulose were added to the autoclave. Methyl cellulose had a viscosity of 50 cP and was stirred in the batch inside the autoclave at 500 rpm to act as a suspension stabilizer. The batch inside the autoclave was maintained at a temperature of 52°C.

[0044] A monomer composed of 25% by weight of VDF, 55% by weight of HFP, and 20% by weight of TFE was mixed into the batch and used as a carrier gas, and charged at 20 kg/cm2. Subsequently, 40 g of a solution of about 85% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane and 15% by weight of diisopropyl peroxydicarbonate was charged as a catalyst to initiate the polymerization. Diisopropyl peroxydicarbonate acted as an initiator to initiate polymerization. As the pressure is reduced during the polymerization reaction a mixed monomer having 40 wt% VDF, 35 wt% HFP and 25 wt% TFE is added to increase the pressure back to 20 kg/cm2. After completion of the polymerization reaction, the remaining mixed monomer was cleaned, and the resulting suspension was dehydrated with a centrifugal separator, washed with deionized (DI) water, and then vacuum dried at 100°C to obtain about 6 kg of polymer Fluorinated Example B.

Fluorinated Polymer Example C

[0045] Fluorinated Polymer Example C was produced using an autoclave and induction stirrer similar to those used to produce Fluorinated Polymer Example A. The autoclave was sufficiently cleaned with nitrogen gas, and charged with 3 liters of a purified water composition deoxidized water and 30 g of ammonium perfluorodecanoate, which acted as an emulsifier. The composition was heated in the autoclave to 60°C and stirred at 380 rpm.

[0046] The autoclave was then charged with a gas mixture of about 70% by weight VDF and about 30% by weight HFP until the internal pressure of the autoclave reached 20 kg/cm2. Subsequently, 40 g of a solution containing about 80% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane and 20% by weight of diisopropyl peroxydicarbonate was added into the autoclave using nitrogen. Diisopropyl peroxydicarbonate acted as a catalyst to initiate polymerization.

[0047] The internal pressure inside the autoclave was maintained at 20 kg/cm2 during polymerization by successively injecting a gas mixture of VDF (62% by weight) and HFP (38% by weight). As the polymerization rate decreased as the polymerization progressed, an additional 30 g of solution containing about 80% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane and 20% by weight was injected. weight of diisopropyl peroxydicarbonate using nitrogen gas 3 hours after the start of the polymerization reaction. The monomers were polymerized for a further 3 hours and the resulting suspension was dehydrated with a centrifugal separator with DI water and vacuum dried at 100°C to obtain about 7.2 kg of Example C Fluorinated Polymer.

Fluorinated Polymer Example D

[0048] Fluorinated Polymer Example D was produced using an autoclave having a volume of about 3 liters, which served as a batch reactor. The autoclave had an electromagnetic induction stirrer. A batch of 936 g of DI water, 0.36 g of methyl cellulose, 360 g of VDF, 0.3 g of terthiobutyl peroxypivalate, 0.36 g of sodium pyrophosphate, sodium acid pyrophosphate and 1.8 g of diethyl carbonate was added to the autoclave. The batch was stirred at 10°C for 30 minutes and then heated to 45°C for 140 minutes.

[0049] The maximum pressure inside the autoclave was 6 MPa. The polymerization of the monomers ended when the pressure in the autoclave reduced to 2.5 MPa, which occurred 15 hours after the initial heating of the monomers. After completing polymerization the polymer slurry was removed, dehydrated, washed with DI water, dehydrated and then dried at 80°C for 24 hours to obtain a vinylidene fluoride polymer (Fluorinated Polymer Example D) having an inherent viscosity of 2 .05 dL/g and an apparent density of 0.225 g/mL in a yield of 55%.

Example 2

[0050] An exemplary non-limiting method for preparing EVOH resin compositions and particles formed therefrom is provided below. The EVOH resin compositions and pellets thereof contained a content of boron and fluorine particles. Specifically, eighteen exemplary EVOH resin compositions (EVOH Example 1-18) and eleven comparative EVOH resin compositions (Comparative EVOH 111) were prepared according to methods similar to the method disclosed below. However, the specific methods for producing EVOH 1-18 and Comparative EVOH 1-11 have typically varied from the method disclosed below in one or more ways.

[0051] Ethylene-vinyl acetate copolymer with an ethylene content of 29 mol%, underwent saponification by 99.5% to produce EVOH polymers. Subsequently, the EVOH polymers were dissolved in a solution comprising methanol and water in a weight ratio of 70:30. After dissolving the EVOH polymers in the methanol and water solution, the solution had a solids content of 41% by weight of EVOH polymers. The solution was maintained at a temperature of 60°C.

[0052] The methanol, water and EVOH solution was subsequently pelletized using underwater pelletization. Specifically, the methanol, water, and EVOH solution was pumped into a feed tube at a flow rate of 120 L/min. The solution was transferred to an inlet tube that had a diameter of 2.8 mm, and then cut by a rotary knife at a speed of 1500 rpm. The EVOH were cooled by adding water having a temperature of 5°C. The EVOH were subsequently centrifuged to separate the EVOH pellet into particles. The separated EVOH particles were washed with water, dipped into a boric acid solution and stirred, and then dried to obtain an EVOH pellet.

[0053] The EVOH pellet was mixed with a fluorinated polymer, for example, such as those discussed in Example 1, in certain ratios and then transferred to a twin screw extruder. The twin screw extruder had different temperatures across thirteen zones, as summarized in Table 1, below. In Table 1, “EV27” refers to an EVOH having an ethylene content of 27 mol%, “EV29” refers to an EVOH having an ethylene content of 29 mol%, “EV32” refers to an EVOH having an ethylene content of 32 mol%, “EV38” refers to an EVOH having an ethylene content of 38 mol%, and “EV44” refers to an EVOH having an ethylene content of 44 mol%. Table 1

Example 3

[0054] Each of EVOH Examples 1-18 and EVOH Comparatives 1-11 was formed into a film according to the method described below. Films were produced by feeding Example EVOH 1-18 and Comparative EVOH 1-11 into a single-layer T-cast film extruder (MEV4 optical control system). Each of the films formed from EVOH Examples 1-18 and EVOH Comparatives 1-11 had a thickness of 20 μm. The extruder temperature was set to 220°C, while the die temperature was set to 230°C. The rotational frequency of the spindle was 7 revolutions per minute (rpm).

Example 4

[0055] Eighteen exemplary, non-limiting EVOH resin compositions containing fluorine particles (EVOH Example 1-18) and eleven comparative EVOH resin compositions (Comparative EVOH 1-11) were prepared according to methods similar to those discussed in Example 2. Table 2, shown below, provides a summary of certain attributes, namely, the ethylene content of EVAC, the specific fluorinated polymer incorporated into EVOH, the amount of such polymer, and the boron content of EVOH Example 1-18 and of Comparative EVOH 1-11. Table 2

[0056] EVOH Examples 1-18 and Comparative EVOH 1-11 were evaluated to determine boron content. A sample solution of each of EVOH Examples 1-18 and Comparative EVOH 1-11 was prepared by breaking 0.1 g of each of the EVOH resin compositions into concentrated nitric acid during microwave application. The sample solution was then diluted with pure water to adjust the concentration to 0.75 mg/mL. The amount of boron contained in the prepared solution was measured using an inductively applied plasma (“ICP”) emission spectrochemical analysis (ICP-OES) with a Thermo iCAP7000 analyzer. The amount of boron, as a measurement value, corresponds to the amount of boron derived from the boron compound used.

[0057] EVOH Examples 1-18 and Comparative EVOH 1-11 were evaluated to determine the boron content and melting point temperatures of EVOH Examples 1-18 and Comparative EVOH 1-11 according to the procedures described above. Films were formed from EVOH Examples 1-18 and Comparative EVOH 1-11 according to methods similar to that described in Example 3. Films from EVOH Examples 1-18 and Comparative EVOH 1-11 were then evaluated to determine uniformity. of film thickness, matrix precipitation, appearance (the number of fish eyes) of such films, the Charpy impact (shock) resistance of the films, and the elongation at break of the films using the qualitative assessment procedures and metrics discussed below . Table 3 provides a summary of the film properties of EVOH Examples 1-18 and Comparative EVOH 1-11. Table 3

[0058] The uniformity of the film thickness was evaluated by fixing a first point as the central point, fixing a second point 4 cm from the first point in a first direction and fixing a third point 4 cm from the first point in a direction opposite to that of the second point. The thickness was then determined at the first point, second point and third point. Based on the determined thicknesses of the first point, second point and third point, the deviation in film thickness was evaluated using the following formulas, where the first point is referred to as “A”, the second point is referred to as “B” and the third point is referred to as “C”. The film thickness is measured using a thickness measuring device (TECLOCK, SM-1201). △Tab= |(A-B)|/(A or B) △Tbc = |(B-C)|/(B or C) △Tac = |(A-C)|/(A or C)

[0059] If each of the above thickness deviations was less than or equal to 5%, then the film had an excellent thickness deviation and was given an “O”. If one or more of the thickness deviations was greater than 5% then the film had a moderate thickness deviation and was given an “X”.

[0060] For the appearance of films formed from EVOH Examples 1-18 and Comparative EVOH 1-11, the number of fish eyes was evaluated at three levels: (1) the number of fish eyes having a size greater than 200 μM within one square meter of the film was less than 3; (2) the number of fish eyes having a size greater than 200 μM within one square meter of the film was 3 to 10; and (3) the number of fish eyes having a size greater than 200 μM within one square meter of the film was greater than 10.

[0061] The number of fish eyes was tested using a charged coupled device (CCD) sensor and FSA-100 device using the FSA-100 V.8 software.

[0062] For Charpy shock (impact) resistance values, the specimens were kept at a relative humidity of 50% ± 5% and a temperature of 23°C ± 2°C for 16 hours before being tested using the ISO 179-1 procedure. The applied impact energy was 7.5 J, the impact direction was inclined, the average width of the specimen was 10.06 mm, and the average thickness of the specimen 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.

[0063] For elongation at break, the test method was in accordance with ISO 527-2 at a temperature of 23°C and the edition was from 2012, the test speed was 50 mm/min, the body type of test was 1A, and the average thickness of the test piece was 3.99 mm.

[0064] The melting point temperatures of EVOH Examples 1-18 and Comparative EVOH 1-11 were determined using a TA-Q200 differential scanning calorimeter (DSC) manufactured by TA Instruments, in accordance with the procedure of ISO 11357-3 (2011), using the 1st melting point temperature and 2nd melting point temperature from the first DSC thermal scan run.

[0065] From the data shown in Table 3, it is surprisingly discovered that if the boron content is within the desired range and the EVOH resin composition contains fluorine as discussed above, the flexibility, mechanical property, thickness uniformity of film and film appearance are improved. The boron content of Comparative EVOH 1, 6, 7, 9 and 11 is greater than 450 ppm leading to the unsatisfactory appearance of film with more than 10 fish eyes within one square meter. EVOH Comparative 2 showed that if there is no fluorinated polymer in the EVOH resin composition, the flexibility, mechanical properties, and precipitation of the matrix do not improve. Comparative EVOH 3, 4, 5, 8 and 10 showed that if the boron content is zero or small, the film thickness uniformity is unsatisfactory.

[0066] EVOH Examples 1-5 and 7-17 and Comparative EVOH 1-11 were further evaluated to determine the particle size range, fluorine content, particle dispersion of EVOH Examples 1-5 and 7-17 and of Comparative EVOH 1-11 according to the procedures described below. Films were formed from EVOH Examples 1-5 and 7-17 and Comparative EVOH 1-11 according to methods similar to those described in Example 3. Films from EVOH Examples 1-5 and 7-17 and Comparative EVOH 1-11 were then evaluated to determine the appearance (number of fish eyes) of such films. Table 4 below provides a summary of the film properties of EVOH Examples 1-5 and 7-17 and Comparative EVOH 1-11. Table 4

[0067] To evaluate the degree of dispersion of particles within EVOH Examples 1-5 and 7-17 and Comparative EVOH 1-11 (if any), in a pellet of EVOH from EVOH Examples 1-5 and 7-17 and EVOH Comparatives 1-11 were cut to produce a specimen with a thickness of 0.5 mm. The cut surface of each EVOH pellet specimen was then evaluated using an optical microscope (a LEICA DM2700M optical microscope sold by LEICA MICROSYSTEMS), a CCD camera (such as those produced by LEICA MICROSYSTEMS) and analyzed with software (by example, LAS software V4.11). The software (e.g., LAS V4.11 software) determined the cross-sectional area length of each of the fluorine-containing particles. An “X” was given to EVOH pellets if one or more particles had a particle size with a diameter or axis length that was greater than 20 μ m or if no particles formed, whereas an “X” was given to EVOH pellets. an “O” if excellent dispersion was exhibited without clumping.

[0068] The fluorine content was determined using a Model JSM-6390 scanning electron microscope, produced by JEOL USA Inc., which was adjusted to a voltage of 15 kV, with an operating distance of 15 mm. Energy dispersive spectroscopy analysis was completed using an Oxford INCA 7582 Instrument. The spot size of the scanning electron microscope was adjusted to make the dead time (holding time) of energy dispersive spectroscopy less than 35%. The acquisition rate for the energy dispersive spectroscopy analysis was set to 1 kcps. Using measurements obtained from scanning electron microscope and energy dispersive spectroscopy, we calculated the fluorine content as a weight percentage (wt%) of the total carbon, oxygen and fluorine content using Kα element signal peaks. 0.2774 keV for carbon, Kα 0.5249 keV for oxygen and Kα 0.6768 keV for fluorine. Additionally, the scanning electron microscope was specifically aimed at the particles during energy dispersive spectroscopy so that the fluorine content mainly reflects the fluorine in the particles. Specifically, each of EVOH Examples 1-5 and 7-17 and EVOH Comparisons 1-11 was evaluated at ten places.

[0069] As shown in Table 4, the films formed from EVOH Examples 1-5 and 7-17 further contained a preferable range of particle sizes, exhibited excellent film appearance with less than three fish eyes within one meter square and excellent precipitation in the matrix.

[0070] As used herein, all ranges provided are intended to include each specific range within and combination of subranges between the given ranges. Furthermore, all ranges provided herein include the extreme points of such ranges unless otherwise indicated. Thus a range of 1-5 specifically includes 1, 2, 3, 4, and 5, as well as subranges such as 2-5, 3-5, 2-3, 2-4, 1-4, etc.

[0071] All publications and patent applications cited in this report herein are incorporated by reference, and for any and all purposes, as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. In the event of an inconsistency between the present disclosure and any publications or patent applications incorporated herein by reference, the present disclosure controls.

[0072] When used herein, the terms “comprising”, “having” and “including” are used in their open, non-limiting sense. The terms “a”, “an”, “the” and “a” are understood to encompass the plural as well as the singular. The expression “one or more” means “at least one” and thus can include an individual characteristic or mixtures/combinations.

[0073] Unlike the operational examples, or where otherwise indicated, all numbers expressing quantities of ingredients and/or reaction conditions can be modified in all cases by the expression “about” meaning to be within the limits of +/- 5% of the indicated number. When used herein, the term “substantially free” or “essentially free” means that there is less than about 2% of the specific characteristic. All elements or features positively shown in this disclosure may be negatively excluded from the claims.

Claims (12)

1. Ethylene-vinyl alcohol copolymer resin composition, characterized in that it comprises: an ethylene-vinyl alcohol copolymer; one or more particles containing fluorine; and a boron compound, wherein the ethylene-vinyl alcohol copolymer resin composition has a boron content of 10 to 450 ppm; wherein the fluorine-containing particle or particles comprise a fluorinated polymer. 2. The ethylene-vinyl alcohol copolymer resin composition of claim 1, further comprising: at least two melting point temperatures, a first melting point temperature and a second melting point temperature. Fusion; wherein melting point temperatures are determined using a differential scanning calorimeter (DSC)_TA-Q200 in accordance with the procedure of ISO 113573(2011). 3. Ethylene-vinyl alcohol copolymer resin composition according to claim 2, characterized in that the first melting point temperature is 100°C to 140°C. 4. Ethylene-vinyl alcohol copolymer resin composition according to claim 2, characterized in that the second melting point temperature is 150°C to 195°C. 5. The ethylene-vinyl alcohol copolymer resin composition of claim 1, wherein the fluorine-containing particles comprise from 1.5 to 47% by weight of fluorine, based on the total weight of the elements carbon, oxygen and fluoride. 6. The ethylene-vinyl alcohol copolymer resin composition of claim 1, wherein each of the fluorine-containing particles has a particle size with a diameter or major axis length less than or equal to 20 μ m. 7. The ethylene-vinyl alcohol copolymer resin composition of claim 6, wherein each of the fluorine-containing particles has a particle size with a diameter or a major axis length of 0.3 to 18 μm. 8. The ethylene-vinyl alcohol copolymer resin composition of claim 1, wherein the ethylene-vinyl alcohol copolymer resin composition has a boron content of 20 to 350 ppm. 9. Film comprising the ethylene-vinyl alcohol copolymer resin composition as defined in claim 1, the film being characterized by having a Charpy shock resistance of at least 2.5 kJ/m2 in accordance with ISO 179 -1 at 23°C and elongation at break of at least 18% according to ISO 527-2 at 23°C. 10. Film according to claim 9, characterized in that it has an elongation at break of at least 20%. 11. Multilayer structure, characterized by the fact that it comprises: (a) at least one layer formed by the ethylene-vinyl alcohol copolymer resin, as defined in claim 1; (b) at least one polymeric layer; and (c) at least one adhesive layer. 12. Multilayer structure according to claim 11, characterized in that the polymeric layer is selected from the group consisting of a low-density polyethylene layer, a maleic anhydride-grafted polyethylene layer, a polypropylene layer, a nylon and a combination thereof.