Polyamide blends for polymer films

Abstract

To provide a polyamide film of which characteristics including improved penetration resistance, elongation, toughness, tear strength and shrink resistance are heightened while maintaining attractive components and processing cost efficiency.SOLUTION: A film comprising a polyamide composition, wherein the polyamide composition is a PA6 polymer having less than 86 wt.%, preferably a PA6 polymer having 15 wt.%-85 wt.%, a PA66 / 6 copolymer having more than 14 wt.%, preferably a PA66 / 6 copolymer having 15 wt.%-85 wt.%, preferably being a statistical copolymer, and optionally, PA66 / 6,10, PA6,10, PA66 / 6,12 or PA6,12, or a combination thereof, and optionally, a film containing fine particles of diatomaceous earth and silica, and the film exhibits a penetration resistance of more than 800 N / mm as measured according to the standard test method ASTM F1306-16 (2016).SELECTED DRAWING: None

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is related to and claims priority to U.S. Provisional Patent Application No. 63 / 020,243, filed May 5, 2020, which is incorporated herein by reference.

[0002] FIELD OF THE DISCLOSURE

[0002] This disclosure relates generally to polymeric films, such as biaxially oriented (BO) or machine direction oriented (MDO) films, that have improved puncture resistance and impact resistance, and are particularly useful in packaging applications. [Background technology]

[0003]

[0003] Polymer films or membranes are often used to separate areas or volumes, to hold items, or to function as barriers. Such functional uses of polymer films allow them to play important roles in industrial or food packaging applications. Examples of multilayer polymer film packaging can be found in, for example, meat and cheese packaging, stand-up pouches, and shrink films used for bone-in meat. Examples of monolayer polymer film packaging can be found in, for example, vacuum bagging and protective films for the stiffening of composite structures such as cooking bags or windmill blades used in capturing wind energy. Oriented monolayer polymer films have also been used in composite laminate structures, such as for coffee packaging or retort pouches.

[0004]

[0004] Recent trends in consumer and retailer preferences have led to an increasing demand for packaging materials produced from fewer resources while simultaneously delivering expected performance, appearance, and feel. This demand has spurred interest in reducing polymer packaging film thickness, i.e., film specifications, to reduce material requirements and improve sustainability without significantly affecting film reliability. Such specification reductions can result in substantial cost savings in the film production process. However, these economic benefits must be weighed against any negative costs associated with film failure, such as tearing or bursting, caused by insufficient strength for downstream film product applications.

[0005]

[0005] Some nylons or polyamides are among the most commonly used polymeric materials in film and packaging applications, often selected for their generally good strength and barrier properties. The high melting points and low cost of certain polyamides, such as polyamide 6 (PA6), make them practical and economical choices for packaging materials that are thermoformed or pultruded into three-dimensional shapes. Polyamide 6 films also benefit from a high degree of ease of processing and thermal and rheological compatibility with other thermoplastic components of multilayer laminates. However, the toughness of polyamide 6 films, as measured by, for example, puncture resistance and impact resistance, is not as high as that of other more expensive or less easily processable polymers, especially as the film thickness of polyamide 6 decreases. Summary of the Invention [Problem to be solved by the invention]

[0006]

[0006] Therefore, a need exists for polyamide films with enhanced properties including improved puncture resistance, elongation, toughness, tear strength and shrink resistance, while maintaining attractive composition and processing cost efficiencies. [Means for solving the problem]

[0007] In one aspect, the present disclosure is directed to a polymer film comprising a polyamide composition. The polyamide composition comprises less than or equal to 85% by weight of PA6 polymer and greater than or equal to 15% by weight of PA66 / 6 copolymer. In some embodiments, the relative viscosity of the polyamide composition ranges from 60 to 250 as measured in formic acid. In some embodiments, the PA66 / 6 copolymer of the polyamide composition is a statistical copolymer. In some embodiments, the PA66 / 6 copolymer comprises greater than 70% by weight of adipic acid-hexamethylenediamine units and less than 30% by weight of caprolactam units. In some embodiments, the PA66 / 6 copolymer has a melting point in the range of 200°C to 255°C. The film exhibits a puncture resistance of greater than 800 N / mm, e.g., greater than 850 N / mm. In some embodiments, the film exhibits an impact resistance of greater than 9.6 N. In some cases, the film thickness may be less than 26 microns and / or the film may exhibit a puncture resistance of greater than 825 N / mm. The concentration of total caprolactam units in the polyamide composition may range from 26% to 74% by weight and / or the concentration of total caprolactam units in the non-PA6 may range from 5% to 40% by weight.

[0008] In another aspect, the present disclosure relates to a method for preparing a polymer film. The method includes providing a PA6 polymer and a PA66 / 6 copolymer. The method further includes blending the PA6 polymer and the PA66 / 6 copolymer to form a polyamide composition containing greater than or equal to 15 wt. % PA66 / 6 copolymer. The method further includes casting the formed polyamide composition to form a film. The method further includes stretching the formed film, thereby preparing a polymer film exhibiting a puncture resistance of greater than 850 N / mm.

[0009] In another aspect, the present disclosure resides in an article comprising the polymeric film provided herein. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a graph showing the puncture resistance of provided and comparative polymer films as a function of the concentration of PA66 / 6 copolymer additive in the film. [Figure 2]

[0011] 1 is a graph showing the tensile elongation of provided and comparative polymer films as a function of the concentration of PA66 / 6 copolymer additive in the film. [Figure 3]

[0012] 1 is a graph showing the tensile strength of provided and comparative polymer films as a function of the concentration of PA66 / 6 copolymer additive in the film. [Figure 4]

[0013] 1 is a graph showing the tensile modulus of provided and comparative polymer films as a function of the concentration of PA66 / 6 copolymer additive in the film. DETAILED DESCRIPTION OF THE INVENTION

[0011]

[0014] The present disclosure generally relates to polymeric films that provide advantageous improvements in puncture and impact resistance, toughness and / or strength when used as films, for example, in packaging applications.

[0012]

[0015] For example, although it has yet to be achieved, it would be beneficial for a polymeric film to have sufficient strength to resist tearing or rupturing under forces likely to be experienced when the film is used to package food, chemicals, or other items. The ability of a polymeric film to exhibit high puncture and impact resistance can further advantageously improve the cost of film production and use, as the film can still achieve the desired strength requirements and then the film thickness can be reduced. It would also be beneficial for a polymeric packaging film to have low heat shrinkage, resulting in improved film robustness to higher temperatures and better compatibility with other components in multilayer laminate applications. do.

[0013]

[0016] However, it has been difficult for conventional polymer films to simultaneously meet different performance requirements while also being economical. One reason for this is that polyamide 6 (PA6), the most widely used polyamide in the polymer film market, does not exhibit the same high degree of toughness (e.g., puncture resistance / elongation) as other, more expensive alternatives. Conventional polymer films, such as BP-oriented (BPO) or MD-oriented (MDO) films, generally contain PA6 homopolymer as the only polyamide or polymer component. PA6 is generally chosen for use in films, at least in part, due to its relatively low cost and high processability. In particular, PA6 has a crystallization rate that is amenable to orientation and thermoforming of PA6 films. PA6 also has very good dimensional stability in terms of important properties such as heat resistance and rheology, and very good compatibility with other thermoplastics found in multilayer extrusion. In contrast, substituting other polyamides, such as PA66, for PA6 often results in films with enhanced toughness and barrier properties, but can cause significant disadvantages in the film's versatility and flexibility. Generally, these alternative polyamides have higher costs and faster crystallization rates than PA6 or PA6-rich copolymers, which affect film processing properties such as blow-up ratio, ability to orient the film, and incorporation of the film into thermoforming.

[0014]

[0017] The inventors have now discovered that when utilized in compositions having PA6 as the (major) component, a specific PA66 / 6 copolymer component, optionally added in a certain type, amount, and ratio, is utilized to form a film, e.g., a packaging film, it can improve the performance of the composition's mechanical properties, e.g., toughness, e.g., puncture resistance, and / or, especially, a combination of elongation. In particular, the importance of the type of PA66 / 6 copolyamide additive and the ratio of polyamide composition components in enabling advantageous strength properties has not previously been recognized. The improved strength of films produced using polyamide compositions is reflected, for example, in increased film puncture resistance and impact resistance, as well as increased film elongation to break and overall toughness. Other advantageous properties of the provided films include low heat shrinkage and reduced modulus, which allow for efficient stretching and increased stretch ratios. Furthermore, because the (major) component of the film is PA6, commonly used film processing conditions remain suitable for use with the provided films. These conditions include film extrusion, stretching, and annealing temperatures, and film stretch and relaxation ratios.

[0015] polymer film

[0018] In one embodiment, a polymer film, such as a BO or MDO film, is disclosed. The polymer film is a polyamide film comprising a polyamide composition. Conventional polyamide films generally comprise PA6 homopolymer with little or no copolyamide content. The copolyamide in the disclosed film has been found to provide surprising improvements in the resulting film. For example, the polymer films disclosed herein possess several advantageous performance characteristics, such as increased puncture resistance, impact resistance, and flexibility, due to the presence of PA66 / 6 copolyamide, and in some cases exceed certain minimum limits. Furthermore, the inclusion of PA66 / 6 copolyamide in the provided film can improve film stretch ratios and processing throughput, increasing production yields by, for example, minimizing wasteful film breakage during fabrication.

[0016]

[0019] Many types of polymer films are contemplated. Examples include, but are not limited to, blown and cast films, as well as oriented versions thereof, e.g., BO, MDO. In some embodiments, the film is a BO polymer film. In some cases, the film is an MDO polymer film. Uniaxially oriented films are also contemplated. The film may be made from a polyamide composition, and in some cases, polyamide. The triamide composition may comprise the ingredients described herein.

[0017]

[0020] As used herein, the terms "PA6," "nylon 6," and "polyamide 6" refer to homopolymers prepared from caprolactam monomer subunits. As used herein, the terms "PA66 / 6," "nylon 66 / 6," and "polyamide 66 / 6" refer to copolymers prepared from hexamethylenediamine and adipic acid monomer subunits and also incorporating caprolactam monomer subunits.

[0018]

[0021] In some embodiments, the concentration of PA66 / 6 copolymer in a provided polymer film (or in a polyamide composition from which the film is made) can be, for example, 14% to 100% by weight, e.g., 14% to 66% by weight, 14% to 86% by weight, 15% to 85% by weight, 30% to 85% by weight, 15% to 70% by weight, 23% to 74% by weight, 31% to 83% by weight, 40% to 91% by weight, or 49% to 100% by weight. In terms of the upper limit, the PA66 / 6 concentration in the film can be less than (or equal to) 100% by weight, e.g., less than 91% by weight, less than 85% by weight, less than 83% by weight, less than 74% by weight, less than 70% by weight; less than 66% by weight, less than 57% by weight, less than 48% by weight, less than 40% by weight, less than 31% by weight, or less than 22% by weight. In terms of the lower limit, the PA66 / 6 concentration in the film may be greater than 14 wt%, e.g., greater than 23 wt%, greater than 31 wt%, greater than 40 wt%, greater than 48 wt%, greater than 57 wt%, greater than 66 wt%, greater than 74 wt%, greater than 83 wt%, or greater than 91 wt%. Lower concentrations, e.g., less than 14 wt%, are also contemplated. Other ranges / limits based on examples are contemplated.

[0019]

[0022] In some embodiments, the concentration of PA66 / 6 copolymer in a provided polymer film can be selected to balance improved film strength associated with increasing PA66 / 6 content and improved film cost reduction associated with increasing PA6 content. The PA66 / 6 concentration in the film can be, for example, in the range of 15% to 45% by weight, e.g., 15% to 33%, 18% to 36%, 21% to 39%, 24% to 42%, or 27% to 45% by weight. In terms of the upper limit, the PA66 / 6 concentration in the film can be less than 45% by weight, e.g., less than 42%, less than 39%, less than 36%, less than 33%, less than 30%, less than 27%, less than 24%, less than 21%, or less than 18% by weight. In terms of the lower limit, the PA66 / 6 concentration in the film may be greater than 15 wt%, e.g., greater than 15 wt%, greater than 18 wt%, greater than 21 wt%, greater than 24 wt%, greater than 27 wt%, greater than 30 wt%, greater than 33 wt%, greater than 36 wt%, greater than 39 wt%, or greater than 42 wt%.

[0020]

[0023] In some cases, other combinations of PAs are also contemplated, such as PA66 / 6 copolymers and polyamides other than PA6 polymers.

[0021]

[0024] As used herein, the limits "greater than" and "less than" may also be inclusive of the numbers associated therewith. Alternatively stated, "greater than" and "less than" may be interpreted as "greater than or equal to" and "less than or equal to." It is contemplated that this language may therefore be modified in the claims to include "or equal to." For example, "greater than 4.0" may be interpreted as "greater than or equal to 4.0" and may therefore be so modified in the claims.

[0022]

[0025] The concentration of PA6 polymer in the provided polymer film is, for example, 0 to 86 wt. The PA6 concentration in the film may be in the range of, for example, 0 to 52% by weight, 9 to 60% by weight, 17 to 69% by weight, 14 to 100% by weight, 14 to 66% by weight, 14 to 86% by weight, 15 to 85% by weight, 30 to 85% by weight, 15 to 70% by weight, 26 to 77% by weight, or 34 to 86% by weight. In terms of the upper limit, the PA6 concentration in the film may be less than 86% by weight, for example, less than 77% by weight, less than 69% by weight, less than 60% by weight, less than 52% by weight, less than 43% by weight, less than 34% by weight, less than 26% by weight, less than 17% by weight, or less than 9% by weight. In terms of the lower limit, the PA6 concentration in the film may be greater than 9 wt%, e.g., greater than 17 wt%, greater than 26 wt%, greater than 34 wt%, greater than 43 wt%, greater than 52 wt%, greater than 60 wt%, greater than 69 wt%, or greater than 77 wt%. Higher concentrations, e.g., greater than 86 wt%, are also contemplated. Other ranges / limits are contemplated based on the examples.

[0023]

[0026] The concentration of PA6 polymer in the provided polymer film may be, for example, in the range of 55% to 85% by weight, e.g., 55% to 85% by weight, 55% to 73% by weight, 58% to 76% by weight, 61% to 79% by weight, 64% to 82% by weight, or 67% to 85% by weight. In terms of the upper limit, the PA6 concentration in the film may be less than 85% by weight, e.g., less than 85% by weight, less than 82% by weight, less than 79% by weight, less than 76% by weight, less than 73% by weight, less than 70% by weight, less than 67% by weight, less than 64% by weight, less than 61% by weight, or less than 58% by weight. In terms of the lower limit, the PA6 concentration in the film may be greater than 55 wt%, e.g., greater than 58 wt%, greater than 61 wt%, greater than 64 wt%, greater than 67 wt%, greater than 70 wt%, greater than 73 wt%, greater than 76 wt%, greater than 79 wt%, or greater than 82 wt%.

[0024]

[0027] The weight ratio of PA6 polymer to PA66 / 6 copolymer in the provided polyamide compositions can be, for example, in the range of 0.01:1 to 6.2:1, e.g., 0.01:1 to 0.48:1, 0.02:1 to 0.9:1, 0.04:1 to 1.7:1, 0.07:1 to 3.3:1, or 0.13:1 to 6.2:1. The weight ratio of PA6 polymer to PA66 / 6 copolymer in the provided polyamide compositions can be, for example, in the range of 1:1 to 6:1, e.g., 1:1 to 4:1, 1.5:1 to 4.5:1, 2:1 to 5:1, 2.5:1 to 5.5:1, or 3:1 to 6:1. In terms of an upper limit, the weight ratio of PA6 to PA66 / 6 may be less than 6.2:1, e.g., less than 5.5:1, less than 5:1, less than 4.5:1, less than 4:1, less than 3.5:1, less than 3:1, less than 2.5:1, less than 2:1, less than 1.5:1, less than 0.9:1, less than 0.47:1, less than 0.25:1, less than 0.13:1, less than 0.07:1, less than 0.04:1, or less than 0.02:1. In terms of the lower limit, the weight ratio of PA6 to PA66 / 6 can be greater than 0.01:1, e.g., greater than 0.02:1, greater than 0.04:1, greater than 0.07:1, greater than 0.13:1, greater than 0.25:1, greater than 0.47:1, greater than 0.9:1, greater than 1:1, greater than 1.5:1, greater than 2:1, greater than 2.5:1, greater than 3:1, greater than 3.5:1, greater than 4:1, greater than 4.5:1, greater than 5:1, or greater than 5.5:1. Higher weight ratios, e.g., greater than 6.2:1, and lower weight ratios, e.g., less than 0.01:1, are also contemplated.

[0025]

[0028] In some cases, caprolactam is present in the polyamide composition in the form of PA6 polymer subunits, PA66 / 6 copolymer subunits (see discussion below), and optionally subunits of one or more additional polyamide components of the composition. In some embodiments, the polyamide composition is assembled to provide a combined total caprolactam content within a predetermined target range. For example, the total concentration of caprolactam units in the provided polyamide composition from all combined caprolactam sources may range from 10% to 90% by weight, e.g., 10% to 58%, 18% to 66%, 26% to 74%, 34% to 82%, or 42% to 90% by weight. The total caprolactam concentration in the polyamide composition may range from 55% to 90% by weight, e.g., 55% to 76%, 58.5% to 79%. The caprolactam concentration in the polyamide composition may be in the range of 5% by weight, 62% to 83% by weight, 65.5% to 86.5% by weight, or 69% to 90% by weight. In terms of the upper limit, the caprolactam concentration in the polyamide composition may be less than 90% by weight, for example, less than 86.5% by weight, less than 83% by weight, less than 79.5% by weight, less than 76% by weight, less than 72.5% by weight, less than 69% by weight, less than 65.5% by weight, less than 62% by weight, less than 58.5% by weight, less than 50% by weight, less than 42% by weight, less than 34% by weight, less than 26% by weight, or less than 18% by weight. In terms of the lower limit, the caprolactam concentration in the polyamide composition may be greater than 10 wt%, for example, greater than 18 wt%, greater than 26 wt%, greater than 34 wt%, greater than 42 wt%, greater than 50 wt%, greater than 55 wt%, greater than 58.5 wt%, greater than 62 wt%, greater than 65.5 wt%, greater than 69 wt%, greater than 72.5 wt%, greater than 76 wt%, greater than 79.5 wt%, greater than 83 wt%, or greater than 86.5 wt%. Higher caprolactam concentrations, for example, greater than 90 wt%, and lower caprolactam concentrations, for example, less than 10 wt%, are also contemplated. The use of these amounts of caprolactam has been found to unexpectedly provide an advantageous combination of performance characteristics, as the film can derive the strength and economic benefits associated with caprolactam units without having to include a polyamide composition consisting solely of PA6 homopolymer.

[0026]

[0029] The weight ratio of the total caprolactam units in the polyamide composition to the total adipic acid-hexamethylenediamine units in the polyamide composition may be, for example, in the range of 0.1:1 to 9:1, e.g., 0.1:1 to 1.5:1, 0.16:1 to 2.3:1, 0.25:1 to 3.7:1, 0.39:1 to 5.7:1, or 0.6:1 to 9:1. The weight ratio of the total caprolactam units to the total adipic acid-hexamethylenediamine units in the polyamide composition may be in the range of 1:1 to 9:1, e.g., 1:1 to 5.8:1, 1.8:1 to 6.6:1, 2.6:1 to 7.4:1, 3.4:1 to 8.2:1, or 4.2:1 to 9:1. In terms of the upper limit, the weight ratio of caprolactam units to adipic acid-hexamethylenediamine units in the polyamide composition may be less than 9:1, for example, less than 8.2:1, less than 7.4:1, less than 6.6:1, less than 5.8:1, less than 5:1, less than 4.2:1, less than 3.4:1, less than 2.6:1, less than 1.8:1, less than 1.5:1, less than 0.95:1, less than 0.6:1, less than 0.39:1, less than 0.25:1, or less than 0.16:1. In terms of the lower limit, the weight ratio of caprolactam units to adipic acid-hexamethylenediamine units in the polyamide composition can be greater than 0.1:1, e.g., greater than 0.16:1, greater than 0.25:1, greater than 0.39:1, greater than 0.6:1, greater than 0.95:1, greater than 1:1, greater than 1.5:1, greater than 1.8:1, greater than 2.6:1, greater than 3.4:1, greater than 4.2:1, greater than 5:1, greater than 5.8:1, greater than 6.6:1, greater than 7.4:1, or greater than 8.2:1. Higher weight ratios, e.g., greater than 9:1, and lower weight ratios, e.g., less than 0.1:1, are also contemplated.

[0027]

[0030] In some cases, the film may contain adipic acid units in an amount ranging from 10% to 60% by weight, e.g., from 15% to 55% by weight, from 20% to 50% by weight, from 25% to 45% by weight, or from 30% to 36% by weight. At the lower end, the film may contain more than 10% by weight, e.g., more than 15% by weight, more than 20% by weight, more than 25% by weight, or more than 30% by weight. At the upper end, the film may contain less than 60% by weight, e.g., less than 55% by weight, less than 50% by weight, less than 45% by weight, or less than 36% by weight.

[0028]

[0031] The film may contain hexamethylenediamine units in amounts similar to those disclosed for the adipic acid units.

[0029]

[0032] In some cases, the film may contain caprolactam units in an amount ranging from 10% to 70% by weight, e.g., from 15% to 65% by weight, from 20% to 60% by weight, from 20% to 50% by weight, or from 28% to 40% by weight. The film may contain more than 10 wt.%, for example more than 10 wt.%, more than 15 wt.%, more than 20 wt.%, or more than 28 wt.% caprolactam units. In terms of the upper limit, the film may contain less than 60 wt.%, for example less than 70 wt.%, less than 65 wt.%, less than 60 wt.%, less than 50 wt.%, or less than 40 wt.% caprolactam units.

[0030]

[0033] The polymer film or polymer composition itself may advantageously have a high heat distortion temperature. For example, the polymer film may have a heat distortion temperature of greater than 190°C, e.g., greater than 215°C, greater than 220°C, greater than 222°C, greater than 225°C, greater than 227°C, greater than 230°C, greater than 232°C, greater than 235°C, greater than 240°C, greater than 245°C, greater than 250°C, or greater than 255°C. In terms of range, the polymer film may have a heat distortion temperature in the range of 190°C to 300°C, e.g., 215°C to 260°C, 220°C to 260°C, 225°C to 255°C, 225°C to 250°C, 230°C to 250°C, 235°C to 250°C, or 235°C to 245°C.

[0031]

[0034] In some cases, the polymer film or polymer composition itself may advantageously have a melting point. For example, the polymer film may have a melting point greater than 220°C, e.g., greater than 222°C, greater than 225°C, greater than 227°C, greater than 230°C, greater than 232°C, greater than 235°C, greater than 240°C, greater than 245°C, greater than 250°C, or greater than 255°C. In terms of range, the polymer film may have a melting point in the range of 215°C to 260°C, e.g., 220°C to 260°C, 225°C to 255°C, 225°C to 250°C, 230°C to 250°C, 235°C to 250°C, or 235°C to 245°C.

[0032]

[0035] In some cases, the melting point of the polymer composition (or one or more of its components) contributes, at least in part, to the improvement in heat deflection temperature.

[0033]

[0036] The films of the present disclosure can be characterized by a heat distortion temperature and / or a melting point. In some cases, the heat distortion temperature and / or melting point can be characterized regardless of the compositional make-up of the film or the polymer composition from which the film is made.

[0034]

[0037] It has also been discovered that the relative viscosity of one or more component polymers and copolymers, in addition to the compositional makeup of the polyamide composition, can provide surprising benefits in both performance and processing. For example, when the relative viscosity of the polyamide composition is within certain ranges and / or limits, production speed and strength are improved. As used herein, "relative viscosity" or "RV" refers to a comparison of the viscosity of formic acid itself with the viscosity of a solution of the polymer in formic acid, as measured using 90% formic acid and a glass capillary Ubbelohde viscometer according to standard test method ASTM D789-19(2019).

[0035]

[0038] The provided polyamide composition can have a relative viscosity in the range of, for example, 60 to 250, e.g., 60 to 174, 79 to 193, 98 to 212, 117 to 231, or 136 to 250. The polyamide composition can have a relative viscosity in the range of 100 to 200, e.g., 100 to 160, 110 to 170, 120 to 180, 130 to 190, or 140 to 200. The polyamide composition can have a relative viscosity in the range of 130 to 170, e.g., 130 to 154, 134 to 158, 138 to 162, 142 to 166, or 146 to 170. The polyamide composition can have a relative viscosity in the range of 80 to 110, e.g., 80 to 98, 83 to 101, 86 to 104, 89 to 107, or 92 to 110. The polyamide composition can have a relative viscosity of 90 to 100, for example, 90 to 96, 91 to 97, 92 to 98, 93 to 99, or 94 to 100. In view of this, the relative viscosity of the polyamide composition may be less than 250, e.g., less than 231, less than 212, less than 193, less than 180, less than 174, less than 170, less than 166, less than 162, less than 158, less than 154, less than 150, less than 146, less than 142, less than 138, less than 134, less than 130, less than 120, less than 110, less than 107, less than 104, less than 101, less than 100, less than 99, less than 98, less than 97, less than 96, less than 95, less than 94, less than 93, less than 92, less than 91, less than 90, less than 89, less than 86, less than 83, less than 80, or less than 76. In terms of the lower limit, the relative viscosity of the amide composition may be greater than 60, e.g., greater than 76, greater than 80, greater than 83, greater than 86, greater than 89, greater than 90, greater than 91, greater than 92, greater than 93, greater than 94, greater than 95, greater than 96, greater than 97, greater than 98, greater than 99, greater than 100, greater than 101, greater than 104, greater than 107, greater than 110, greater than 120, greater than 130, greater than 134, greater than 138, greater than 142, greater than 146, greater than 150, greater than 154, greater than 158, greater than 162, greater than 166, greater than 170, greater than 174, greater than 180, greater than 193, greater than 212, or greater than 231. Higher relative viscosities, e.g., greater than 250, and lower relative viscosities, e.g., less than 60, are also contemplated.

[0036]

[0039] The enhanced mechanical properties of the provided polymer film allow the film to exhibit desired strength at a reduced film thickness. Stated differently, the film of the present disclosure provides excellent film performance even when the film is thinner. Therefore, for example, material costs can be reduced while maintaining excellent puncture resistance and impact resistance properties, which are advantageous in packaging applications. The provided film can have a thickness in the range of, for example, 5 micrometers to 40 micrometers, e.g., 5 micrometers to 26 micrometers, 8.5 micrometers to 29.5 micrometers, 12 micrometers to 33 micrometers, 15.5 micrometers to 36.5 micrometers, or 19 micrometers to 40 micrometers. In terms of the upper limit, the film thickness can be less than 40 micrometers, e.g., less than 36.5 micrometers, less than 33 micrometers, less than 29.5 micrometers, less than 26 micrometers, less than 22.5 micrometers, less than 19 micrometers, less than 15.5 micrometers, less than 12 micrometers, or less than 8.5 micrometers. In terms of lower limits, the film thickness may be greater than 5 micrometers, e.g., greater than 8.5 micrometers, greater than 12 micrometers, greater than 15.5 micrometers, greater than 19 micrometers, greater than 22.5 micrometers, greater than 26 micrometers, greater than 29.5 micrometers, greater than 33 micrometers, or greater than 36.5 micrometers. Larger thicknesses, e.g., greater than 40 micrometers, and smaller thicknesses, e.g., less than 5 micrometers, are also contemplated.

[0037]

[0040] In some cases, polymeric films of the present disclosure beneficially have a relative viscosity greater than 0.5, e.g., greater than 0.7, greater than 1.0, greater than 1.5, greater than 2.0, greater than 2.5, greater than 3.0, greater than 3.2, or greater than 3.5. In terms of range, the films may have a relative viscosity in the range of 0.5 to 10.0, e.g., 0.5 to 8.0, 0.5 to 5.0, 1.0 to 6.0, 1.0 to 5.0, 2.0 to 6.0, or 2.5 to 5.0.

[0038] PA66 / 6 copolymer

[0041] The PA66 / 6 copolymer additives of the provided polymer films have constituent subunit monomer and block assemblies described herein and can be selected to impart desired toughness to the film without diminishing the film properties associated with high processability. In some embodiments, the PA66 / 6 copolymer is a statistical copolymer, i.e., a PA66-s-6 having statistically defined amounts of constituent subunits. As used herein, the term "statistical copolymer" refers to a polymer that is formed by reacting constituent subunits together statistically to form a polymer. This refers to a copolymer formed from units distributed throughout the copolymer backbone.

[0039]

[0042] The concentration of adipic acid-hexamethylenediamine units in the PA66 / 6 copolymer of the provided polyamide composition can be, for example, between 70% and 100% by weight, e.g., between 70% and 88% by weight, between 75% and 85% by weight, between 73% and 91% by weight, between 76% and 94% by weight, between 79% and 97% by weight, or between 82% and 100% by weight. The concentration of adipic acid-hexamethylenediamine units in the PA66 / 6 copolymer can be, for example, in the range of 75% to 85% by weight, e.g., 75% to 81% by weight, 76% to 82% by weight, 77% to 83% by weight, 78% to 84% by weight, or 79% to 85% by weight. In terms of the lower limit, the adipic acid-hexamethylenediamine concentration in the PA66 / 6 copolymer may be greater than 70 wt%, e.g., greater than 73 wt%, greater than 75 wt%, greater than 76 wt%, greater than 77 wt%, greater than 78 wt%, greater than 79 wt%, greater than 80 wt%, greater than 81 wt%, greater than 82 wt%, greater than 83 wt%, greater than 84 wt%, greater than 85 wt%, greater than 88 wt%, greater than 91 wt%, greater than 94 wt%, or greater than 97 wt%. In terms of upper limits, the adipic acid-hexamethylenediamine concentration in the PA66 / 6 copolymer can be less than 100% by weight, such as less than 97%, less than 94%, less than 91%, less than 88%, less than 85%, less than 84%, less than 83%, less than 82%, less than 81%, less than 80%, less than 79%, less than 78%, less than 77%, less than 76%, less than 75%, or less than 73% by weight. Lower adipic acid-hexamethylenediamine concentrations, such as less than 70% by weight, are also contemplated.

[0040]

[0043] The concentration of caprolactam units in the PA66 / 6 copolymer of the provided polyamide composition can be, for example, 0 to 30 wt%, e.g., between 0 and 18 wt%, between 3 and 21 wt%, between 6 and 24 wt%, between 9 and 27 wt%, or between 12 and 30 wt%. The caprolactam concentration in the PA66 / 6 copolymer can be, for example, in the range of 15 to 25 wt%, e.g., 15 to 21 wt%, 16 to 22 wt%, 17 to 23 wt%, 18 to 24 wt%, or 19 to 25 wt%. In terms of the upper limit, the caprolactam concentration in the PA66 / 6 copolymer may be less than 30 wt%, for example, less than 27 wt%, less than 25 wt%, less than 24 wt%, less than 23 wt%, less than 22 wt%, less than 21 wt%, less than 20 wt%, less than 19 wt%, less than 18 wt%, less than 17 wt%, less than 16 wt%, less than 15 wt%, less than 12 wt%, less than 9 wt%, less than 6 wt%, or less than 3 wt%. In terms of the lower limit, the caprolactam concentration in the PA66 / 6 copolymer may be greater than 3 wt%, for example, greater than 6 wt%, greater than 9 wt%, greater than 12 wt%, greater than 15 wt%, greater than 16 wt%, greater than 17 wt%, greater than 18 wt%, greater than 19 wt%, greater than 20 wt%, greater than 21 wt%, greater than 22 wt%, greater than 23 wt%, greater than 24 wt%, greater than 25 wt%, or greater than 27 wt%. Higher caprolactam concentrations, for example, greater than 30% by weight, are also contemplated.

[0041]

[0044] In some cases, the polymer composition may include additional polymers / copolymers (see discussion below). In some embodiments, the total concentration of caprolactam units in the non-PA6 polymer (all polymers other than PA-6 present in the composition, including PA66 / 6 copolymers and optional additional polymers / copolymers) may be between 0 and 50 wt%, e.g., between 5 wt% and 40 wt%, between 10 wt% and 35 wt%, between 10 wt% and 30 wt%, between 10 wt% and 25 wt%, or between 15 wt% and 30 wt%. In terms of the upper limit, the caprolactam concentration in the non-PA6 polymer may be less than 50 wt%, e.g., less than 45 wt%, less than 40 wt%, less than 35 wt%, less than 30 wt%, less than 25 wt%, less than 20 wt%, less than 15 wt%, less than 10 wt%, or less than 5 wt%, less than 17 wt%. In terms of the lower limit, the caprolactam concentration in the non-PA6 polymer may be less than 50 wt%, e.g., less than 45 wt%, less than 40 wt%, less than 35 wt%, less than 30 wt%, less than 25 wt%, less than 20 wt%, less than 15 wt%, less than 10 wt%, or less than 5 wt%, less than 17 wt%. The caprolactam concentration in the 6 / 6 copolymer may be greater than 0 wt%, for example, greater than 3 wt%, greater than 5 wt%, greater than 8 wt%, greater than 10 wt%, greater than 12 wt%, greater than 15 wt%, greater than 18 wt%, greater than 20 wt%, greater than 22 wt%, greater than 25 wt%, greater than 27 wt%, greater than 30 wt%, or greater than 35 wt%. The aforementioned ranges and limits for the caprolactam concentration in the PA66 / 6 copolymer also apply here.

[0042]

[0045] The weight ratio of adipic acid-hexamethylenediamine units to caprolactam units in the PA66 / 6 copolymer of the provided polyamide composition may be, for example, in the range of 2:1 to 19:1, e.g., 2:1 to 12.2:1, 3.7:1 to 13.9:1, 5.4:1 to 15.6:1, 7.1:1 to 17.3:1, or 8.8:1 to 19:1. In terms of the upper limit, the weight ratio of adipic acid-hexamethylenediamine units to caprolactam units in the PA66 / 6 copolymer may be less than 19:1, e.g., less than 17.3:1, less than 15.6:1, less than 13.9:1, less than 12.2:1, less than 10.5:1, less than 8.8:1, less than 7.1:1, less than 5.4:1, or less than 3.7:1. In terms of the lower limit, the weight ratio of adipic acid-hexamethylenediamine units to caprolactam units in the PA66 / 6 copolymer can be greater than 2:1, e.g., greater than 3.7:1, greater than 5.4:1, greater than 7.1:1, greater than 8.8:1, greater than 10.5:1, greater than 12.2:1, greater than 13.9:1, greater than 15.6:1, greater than 17.3:1. Higher ratios, e.g., greater than 19:1, and lower ratios, e.g., less than 2:1, are also contemplated.

[0043]

[0046] The relatively high melting point of the PA66 / 6 copolyamide additive can be beneficial in imparting advantageous properties to the oriented film, which can include reduced burn-through potential and improved clarity and transmittance. The PA66 / 6 copolymer of the provided polyamide composition can have a melting point in the range of, for example, 200°C to 260°C, e.g., 200°C to 255°C, 200°C to 233°C, 205.5°C to 238.5°C, 211°C to 244°C, 216.5°C to 249.5°C, 220°C to 260°C, or 222°C to 255°C. The melting point of the PA66 / 6 copolymer may be, for example, in the range of 215°C to 223°C, e.g., 215°C to 219.8°C, 215.8°C to 220.6°C, 216.6°C to 221.4°C, 217.4°C to 222.2°C, or 218.2°C to 223°C. The melting point of the PA66 / 6 copolymer may be, for example, in the range of 230°C to 238°C, e.g., 230°C to 234.8°C, 230.8°C to 235.6°C, 231.6°C to 236.4°C, 232.4°C to 237.2°C, or 233.2°C to 238°C. In terms of an upper limit, the melting point of the PA66 / 6 copolymer may be less than 255°C, e.g., less than 249.5°C, less than 244°C, less than 238°C, less than 237.2°C, less than 236.4°C, less than 235.6°C, less than 234.8°C, less than 234°C, less than 233.2°C, less than 232.4°C, less than 231.6°C, less than 230.8°C, less than 230°C, less than 227.5°C, less than 225°C, less than 223°C, less than 222.2°C, less than 221.4°C, less than 220.6°C, less than 219.8°C, less than 219°C, less than 218.2°C, less than 217.4°C, less than 216.6°C, less than 215.8°C, less than 211°C, or less than 205.5°C.In terms of the lower limit, the melting point of the PA66 / 6 copolymer may be greater than 200°C, e.g., greater than 205.5°C, greater than 211°C, greater than 215.8°C, greater than 216.6°C, greater than 217.4°C, greater than 218.2°C, greater than 219°C, greater than 219.8°C, greater than 220.0°C, greater than 220.6°C, greater than 221.4°C, greater than 222.2°C, greater than 223°C, greater than 225°C, greater than 227.5°C, greater than 230°C, greater than 230.8°C, greater than 231.6°C, greater than 232.4°C, greater than 233.2°C, greater than 234°C, greater than 234.8°C, greater than 235.6°C, greater than 236.4°C, greater than 237.2°C, greater than 238°C, greater than 244°C, or greater than 249.5°C. Higher melting temperatures, eg, above 255°C, and lower melting temperatures, eg, below 200°C, are also contemplated.

[0044]

[0047] PA66 / 6 copolyamides can have relatively high heat deflection temperatures, which can contribute to performance characteristics. For example, PA66 / 6 copolyamides can have heat deflection temperatures greater than 190°C, e.g., greater than 215°C, greater than 220°C, greater than 222°C, greater than 225°C, greater than 227°C, greater than 230°C, greater than 232°C, greater than 235°C, greater than 240°C, greater than 245°C, greater than 250°C, or greater than 255°C. In terms of range, PA66 / 6 copolyamides can have heat deflection temperatures in the range of 190°C to 300°C, e.g., 215°C to 260°C, 220°C to 260°C, 225°C to 255°C, 225°C to 250°C, 230°C to 250°C, 235°C to 250°C, or 235°C to 245°C.

[0045] Other additives

[0048] In some embodiments, the provided polymer film includes another heat stabilizer. One or more heat stabilizers in the film can be selected, for example, to improve performance at higher operating temperatures without significantly negatively impacting the strength of the material. At least one of the heat stabilizers can include copper. In some embodiments, all of the heat stabilizers in the film include copper. Copper stabilizers suitable for use as components of the provided film include copper halides, such as chloride, bromide, iodide, or combinations thereof. Copper stabilizers can also include copper cyanide, copper oxide, copper sulfate, copper phosphate, copper acetate, copper propionate, copper benzoate, copper adipate, copper terephthalate, copper isophthalate, copper salicylate, copper nicotinate, copper stearate, copper complexes coordinated to chelating amines such as ethylenediamine and ethylenediaminetetraacetic acid, and combinations thereof.

[0046]

[0049] In some embodiments, at least a portion of the copper in the polymer film is in the form of copper iodide:potassium iodide having a mass ratio ranging from 1:4 to 1:10, e.g., from 1:4 to 1:7.6, from 1:4.6 to 1:8.2, from 1:5.2 to 1:8.8, from 1:5.8 to 1:9.4, or from 1:6.4 to 1:10. In terms of the upper limit, the copper iodide:potassium iodide mass ratio may be less than 1:10, e.g., less than 1:9.4, less than 1:8.8, less than 1:8.2, less than 1:7.6, less than 1:7, less than 1:6.4, less than 1:5.8, less than 1:5.2, or less than 1:4.6. In terms of the lower limit, the mass ratio of copper iodide to potassium iodide may be greater than 1:4, e.g., greater than 1:4.6, greater than 1:5.2, greater than 1:5.8, greater than 1:6.4, greater than 1:7, greater than 1:7.6, greater than 1:8.2, greater than 1:8.8, or greater than 1:9.4. Higher mass ratios, e.g., greater than 1:10, and lower mass ratios, e.g., less than 1:4, are also contemplated.

[0047]

[0050] In some embodiments, the overall copper concentration in the provided polymer film ranges from 30 ppm to 500 ppm, e.g., from 30 ppm to 160 ppm, from 40 ppm to 210 ppm, from 53 ppm to 280 ppm, from 70 ppm to 380 ppm, or from 92 ppm to 500 ppm. In terms of the upper limit, the film copper concentration may be less than 500 ppm, e.g., less than 380 ppm, less than 280 ppm, less than 210 ppm, less than 160 ppm, less than 120 ppm, less than 92 ppm, less than 70 ppm, less than 53 ppm, or less than 40 ppm. In terms of the lower limit, the film copper concentration may be greater than 30 ppm, e.g., greater than 40 ppm, greater than 53 ppm, greater than 70 ppm, greater than 92 ppm, greater than 120 ppm, greater than 160 ppm, greater than 210 ppm, greater than 280 ppm, or greater than 380 ppm. Higher concentrations, for example, greater than 500 ppm, and lower concentrations, for example, less than 30 ppm, are also contemplated.

[0048]

[0051] In some embodiments, the provided polymer film comprises one or more lubricants selected to serve as processing aids for the film. The type and relative amount of lubricant can be selected to improve the processing of the composition and contribute to the high strength of the film material. In some embodiments, the lubricant comprises a wax. In some embodiments, In some embodiments, the lubricant comprises a wax. In some embodiments, the wax comprises a fatty acid. In some embodiments, the lubricant comprises a fatty acid. In some embodiments, the wax comprises a saturated fatty acid. In some embodiments, the lubricant comprises a saturated fatty acid. In some embodiments, the wax comprises stearic acid, behenic acid, or a salt or combination thereof. In some embodiments, the lubricant comprises stearic acid, behenic acid, or a salt or combination thereof. Stearate lubricants can include, for example, zinc stearate, calcium stearate, aluminum distearate, zinc stearate, and / or calcium stearate.

[0049]

[0052] The overall concentration of lubricant in the film may be, for example, in the range of 50 ppm to 5000 ppm, e.g., 50 ppm to 790 ppm, 79 ppm to 1300 ppm, 130 ppm to 2000 ppm, 200 ppm to 3200 ppm, or 320 ppm to 5000 ppm. In terms of the upper limit, the lubricant concentration may be less than 5000 ppm, e.g., less than 3200 ppm, less than 2000 ppm, less than 1300 ppm, less than 790 ppm, less than 500 ppm, less than 320 ppm, less than 200 ppm, less than 130 ppm, or less than 79 ppm. In terms of the lower limit, the lubricant concentration may be greater than 50 ppm, e.g., greater than 79 ppm, greater than 130 ppm, greater than 200 ppm, greater than 320 ppm, greater than 500 ppm, greater than 790 ppm, greater than 1300 ppm, greater than 2000 ppm, or greater than 3200 ppm. Higher concentrations, e.g., greater than 5000 ppm, and lower concentrations, e.g., less than 50 ppm, are also contemplated.

[0050]

[0053] In some embodiments, the provided polymer film contains one or more anti-blocking agents selected to prevent the film from sticking to itself, for example, when tightly wound on a roll. Typically, the agent is added to reduce the surface energy of the film or to create nanoscale bumps that reduce the coefficient of friction of the film surface. Additionally, anti-blocking agents can balance film flow and stretching stability during film processing. Anti-blocking agents suitable for use with the provided film can include inorganic solids, such as, for example, forms of diatomaceous earth. Diatomaceous earth can include, for example, talc, calcium carbonate, silicon dioxide, magnesium silicate, sodium silicate, aluminum silicate, potassium aluminum silicate, or combinations thereof.

[0051]

[0054] The concentration of diatomaceous earth in the film may be, for example, 10 ppm to 1000 ppm, such as 10 ppm to 160 ppm, 16 ppm to 250 ppm, 25 ppm to 400 ppm, 40 ppm to 630 ppm, or 63 ppm to 1000 ppm. In terms of the upper limit, the diatomaceous earth concentration may be less than 1000 ppm, such as less than 630 ppm, less than 400 ppm, less than 250 ppm, less than 160 ppm, less than 100 ppm, less than 63 ppm, less than 40 ppm, less than 25 ppm, or less than 16 ppm. In terms of the lower limit, the diatomaceous earth concentration may be greater than 10 ppm, such as greater than 16 ppm, greater than 25 ppm, greater than 40 ppm, greater than 63 ppm, greater than 100 ppm, greater than 160 ppm, greater than 250 ppm, greater than 400 ppm, or greater than 630 ppm. Higher concentrations, eg, greater than 1000 ppm, and lower concentrations, eg, less than 10 ppm, are also contemplated.

[0052]

[0055] In some embodiments, provided polymer film antiblocking agents can include one or more synthetic waxes, such as, for example, N,N'-ethylenebis(stearamide), stearyl erucamide, glycerol monostearate, zinc stearate, aluminum distearate, calcium stearate, or combinations thereof. The overall concentration of the synthetic wax antiblocking agent in the film can be, for example, 200 ppm to 5000 ppm, e.g., 200 ppm to 1400 ppm, 280 ppm to 1900 ppm, 380 ppm to 2600 ppm, 530 ppm to 3600 ppm, or 720 ppm. The synthetic wax antiblocking agent concentration may range from 1000 ppm to 5000 ppm. In terms of the upper limit, the synthetic wax antiblocking agent concentration may be less than 5000 ppm, e.g., less than 3600 ppm, less than 2600 ppm, less than 1900 ppm, less than 1400 ppm, less than 1000 ppm, less than 720 ppm, less than 530 ppm, less than 380 ppm, or less than 280 ppm. In terms of the lower limit, the synthetic wax antiblocking agent concentration may be greater than 200 ppm, e.g., greater than 280 ppm, greater than 380 ppm, greater than 530 ppm, greater than 720 ppm, greater than 1000 ppm, greater than 1400 ppm, greater than 1900 ppm, greater than 2600 ppm, or greater than 3600 ppm. Higher concentrations, e.g., greater than 5000 ppm, and lower concentrations, e.g., less than 200 ppm, are also contemplated.

[0053]

[0056] In some embodiments, the provided polymer film includes one or more additional copolymers. The additional copolymers can include one or more copolyamides. The additional copolymers can include, for example, PA 6,10, PA 6,12, PA 66 / 6,10, PA 66 / 6,12, or combinations thereof. As used herein, the terms "PA 6,10," "nylon 6,10," and "polyamide 6,10" refer to copolymers prepared from hexamethylenediamine and sebacic acid monomer subunits. As used herein, the terms "PA 6,12," "nylon 6,12," and "polyamide 6,12" refer to copolymers prepared from hexamethylenediamine and dodecanedioic acid monomer subunits. As used herein, the terms "PA66 / 6,10," "nylon 66 / 6,10," and "polyamide 66 / 6,10" refer to a copolymer having chains prepared from hexamethylenediamine and adipic acid monomer units and incorporating chains prepared from hexamethylenediamine and sebacic acid monomer units. In some embodiments, PA66 / 6,10 refers to a statistical copolymer, i.e., a combination of PA66 units and PA6,10 units in PA66-s-6,10. In some embodiments, PA66 / 6,12 refers to a statistical polymer, i.e., a combination of PA66 units and PA6,12 units in PA66-s-6,12.

[0054] Performance characteristics

[0057] The puncture resistance of a material, such as a polymeric film, is a measure of the force required to penetrate the material. Because packaging films are often damaged by penetration from the contents of the package or from forces external to the package, such as those often encountered during shipping and handling, it can be beneficial for polymeric films to have high puncture resistance, particularly when used in packaging applications. Such damage can cause undesirable loss of barrier properties, package integrity, or product appearance. The polymeric films disclosed herein can advantageously exhibit improved puncture resistance compared to conventional polymeric films containing only PA6 in a polyamide composition. Puncture resistance can be measured, for example, using a 1 mm puncture probe radius according to standard test method ASTM F1306-16(2016).

[0055]

[0058] The provided polymer film can exhibit a puncture resistance in the range of, for example, 800 N / mm to 1350 N / mm, e.g., 825 N / mm to 1150 N / mm, 850 N / mm to 1150 N / mm, 850 N / mm to 1075 N / mm, 900 N / mm to 1200 N / mm, 950 N / mm to 1250 N / mm, 1000 N / mm to 1300 N / mm, or 1050 N / mm to 1350 N / mm. In terms of the upper limit, the film puncture resistance can be less than 1350 N / mm, e.g., less than 1300 N / mm, less than 1250 N / mm, less than 1200 N / mm, less than 1150 N / mm, less than 1100 N / mm, less than 1050 N / mm, less than 1000 N / mm, less than 950 N / mm, or less than 900 N / mm. In terms of the lower limit, the film puncture resistance is greater than 800 N / mm, for example, greater than 825 N / mm, greater than 850 N / mm, greater than 900 N / mm, greater than 950 N / mm, greater than 1000 N / mm, greater than 1050 N / mm, greater than 1100 N / mm, greater than 1150 N / mm. / mm, greater than 1200 N / mm, greater than 1250 N / mm, or greater than 1300 N / mm. Higher puncture resistances, for example greater than 1350 N / mm, and lower puncture resistances, for example less than 850 N / mm, are also contemplated.

[0056]

[0059] The strength of a polymer film can also be characterized in terms of its elongation properties. Because packaging materials are often exposed to stretching forces that can cause films with low elongation to tear or rupture, it can be beneficial for polymeric packaging films to have high elongation, e.g., transverse elongation. The polymer films disclosed herein can advantageously exhibit improved elongation compared to conventional polymer films containing only PA6 in a polyamide composition. Elongation can be measured, for example, using standard test method ASTM D882-18(2018).

[0057]

[0060] The provided polymer films can exhibit a transverse elongation in the range of, for example, 85% to 158%, e.g., 88% to 158%, 88% to 130%, 95% to 137%, 85% to 130%, 102% to 144%, 85% to 125%, 109% to 151%, or 116% to 158%. In terms of upper limits, the film transverse elongation can be less than 158%, e.g., less than 151%, less than 144%, less than 137%, less than 130%, less than 123%, less than 116%, less than 109%, less than 102%, or less than 95%. In terms of lower limits, the film transverse elongation may be greater than 85%, e.g., greater than 88%, greater than 90%, greater than 95%, greater than 102%, greater than 109%, greater than 110%, greater than 112%, greater than 116%, greater than 123%, greater than 130%, greater than 137%, greater than 144%, or greater than 151%. Higher elongations, e.g., greater than 158%, and smaller elongations, e.g., less than 88%, are also contemplated. Similar unexpected performance improvements are shown in Figure 2, which shows improvements in the machine direction, 45°, and 135°. Based on the figure, ranges and limits can be inferred for these metrics by those skilled in the art.

[0058]

[0061] The impact resistance of a film is a measure of the film's resistance to fracture due to an impact load. The polymer films disclosed herein can advantageously exhibit improved impact resistance compared to conventional polymer films containing only PA6 in a polyamide composition. Impact resistance can be measured, for example, using standard test method ASTM D1709-16ae1(2016). The provided polymer films can exhibit impact resistance in the range of, for example, 9.6 N to 19.6 N, e.g., 9.6 N to 15.6 N, 10.6 N to 16.6 N, 11.6 N to 17.6 N, 12.6 N to 18.6 N, or 13.6 N to 19.6 N. In terms of an upper limit, the film impact resistance may be less than 19.6 N, e.g., less than 18.6 N, less than 17.6 N, less than 16.6 N, less than 15.6 N, less than 14.6 N, less than 13.6 N, less than 12.6 N, less than 11.6 N, or less than 10.6 N. In terms of a lower limit, the film impact resistance may be greater than 9.6 N, e.g., greater than 10.6 N, greater than 11.6 N, greater than 12.6 N, greater than 13.6 N, greater than 14.6 N, greater than 15.6 N, greater than 16.6 N, greater than 17.6 N, or greater than 18.6 N. Higher impact resistances, e.g., greater than 19.6 N, and lower impact resistances, e.g., less than 9.6 N, are also contemplated.

[0059]

[0062] It can be beneficial for polymeric films to have high tensile strength, e.g., cross-direction tensile strength, due to the film's concomitant resistance to breakage caused by tensile forces. The polymeric films disclosed herein can advantageously exhibit improved tensile strength compared to conventional polymeric films containing only PA6 in a polyamide composition. Tensile strength can be measured, for example, using standard test method ASTM D882-18(2018).

[0060]

[0063] The provided polymer film has a strength of, for example, 250 MPa to 400 MPa, e.g. The film may exhibit a transverse tensile strength in the range of 250 MPa to 340 MPa, 255 MPa to 340 MPa, 265 MPa to 355 MPa, 280 MPa to 370 MPa, 295 MPa to 385 MPa, or 310 MPa to 400 MPa. In terms of the upper limit, the film transverse tensile strength may be less than 400 MPa, for example, less than 385 MPa, less than 370 MPa, less than 355 MPa, less than 340 MPa, less than 325 MPa, less than 310 MPa, less than 295 MPa, less than 280 MPa, or less than 265 MPa. In terms of the lower limit, the film transverse tensile strength may be greater than 250 MPa, for example, greater than 265 MPa, greater than 280 MPa, greater than 295 MPa, greater than 310 MPa, greater than 325 MPa, greater than 340 MPa, greater than 355 MPa, greater than 370 MPa, or greater than 385 MPa. Higher tensile strengths, for example, above 400 MPa, and lower tensile strengths, for example, below 250 MPa, are also contemplated. Similar unexpected performance improvements, showing improvements in the machine direction, 45° and 135°, are shown in Figure 3. Based on the figure, ranges and limits can be inferred for these metrics by one skilled in the art.

[0061]

[0064] The tensile modulus of a polymer film is a measure of the film's resistance to stretching forces. It can be beneficial for a polymeric film to have a low tensile modulus, e.g., a transverse tensile modulus, because a lower modulus can increase the film's elasticity and make it more amenable to processing steps such as film stretching or film thermoforming. The polymer films disclosed herein can advantageously exhibit a reduced tensile modulus compared to conventional polymer films containing only PA6 in a polyamide composition. Tensile modulus can be measured, for example, using standard test method ASTM D882-18(2018).

[0062]

[0065] The provided polymer film can exhibit a transverse tensile modulus in the range of, for example, 2500 MPa to 3800 MPa, e.g., 2500 MPa to 3500 MPa, 2500 MPa to 3100 MPa, 2900 MPa to 3800 MPa, 2600 MPa to 3200 MPa, 2700 MPa to 3300 MPa, 2800 MPa to 3400 MPa, or 2900 MPa to 3500 MPa. In terms of the upper limit, the film transverse tensile modulus may be less than 3800 MPa, e.g., less than 3700 MPa, less than 3600 MPa, less than 3500 MPa, less than 3400 MPa, less than 3300 MPa, less than 3200 MPa, less than 3100 MPa, less than 3000 MPa, less than 2900 MPa, less than 2800 MPa, less than 2700 MPa, or less than 2600 MPa. In terms of the lower limit, the film transverse tensile modulus may be greater than 2500 MPa, for example, greater than 2600 MPa, greater than 2700 MPa, greater than 2700 MPa, greater than 2800 MPa, greater than 2900 MPa, greater than 3000 MPa, greater than 3100 MPa, greater than 3200 MPa, greater than 3300 MPa, or greater than 3400 MPa. Higher tensile moduli, for example, greater than 3500 MPa, and lower tensile moduli, for example, less than 2500 MPa, are also contemplated. Similar unexpected performance improvements, showing improvements in the machine direction, 45° and 135°, are shown in Figure 4. Based on the figure, ranges and limits can be inferred for these metrics by those skilled in the art.

[0063]

[0066] A low heat shrinkage rate for a polymeric film can be beneficial, for example, because it helps maintain the integrity and shape of packaging materials produced using the film. In particular, polymeric films are often laminated with other components, such as additional polymeric films or metal layers, in multilayer configurations. By minimizing the heat shrinkage rate of polymeric films, these films can better maintain their relative position and contact with adjacent layers in a laminate structure. The polymeric films disclosed herein can advantageously exhibit reduced heat shrinkage rates compared to conventional polymeric films containing only PA6 in a polyamide composition.

[0064]

[0067] The provided polymer film can exhibit a heat shrinkage (MD or TD) of, for example, between 0 and 2%, for example, between 0 and 1.2%, between 0.2% and 1.4%, between 0.4% and 1.6%, between 0.6% and 1.8%, or between 0.8% and 2%. In terms of the upper limit, the film heat shrinkage may be less than 2%, for example, less than 1.8%, less than 1.6%, less than 1.4%, less than 1.2%, less than 1%, less than 0.8%, less than 0.6%, less than 0.4%, or less than 0.2%. In terms of the lower limit, the film heat shrinkage may be greater than 0.2%, for example, greater than 0.4%, greater than 0.6%, greater than 0.8%, greater than 1%, greater than 1.2%, greater than 1.4%, greater than 1.6%, or greater than 1.8%. Higher heat shrinkage, for example, greater than 2%, and lower heat shrinkage, for example, less than 2%, are also contemplated.

[0065]

[0068] In some embodiments, a provided polymer film comprises 14% to 46% by weight of PA66 / 6 copolymer, exhibits a puncture resistance in the range of 850 N / mm to 1350 N / m, and exhibits a cross direction elongation in the range of 88% to 158%. The concentration of PA66 / 6 copolymer in the film may be, for example, in the range of 15% to 45%, 15% to 33%, 18% to 36%, 21% to 39%, 24% to 42%, or 27% to 45% by weight. The puncture resistance of the film may be, for example, in the range of 850 N / mm to 1150 N / mm, 900 N / mm to 1200 N / mm, 950 N / mm to 1250 N / mm, 1000 N / mm to 1300 N / mm, or 1050 N / mm to 1350 N / mm. The transverse elongation of the film may be in the range of, for example, 88% to 130%, 95% to 137%, 102% to 144%, 109% to 151%, or 116% to 158%.

[0066]

[0069] In some embodiments, provided polymer films include 14% to 46% by weight of PA66 / 6 copolymer, having a caprolactam unit concentration between 0 and 30% by weight, and exhibit impact resistance in the range of 9.6 N to 19.6 N. The concentration of PA66 / 6 copolymer in the film may be, for example, 15% to 45% by weight, 15% to 33% by weight, 18% to 36% by weight, 21% to 39% by weight, 24% to 42% by weight, or 27% to 45% by weight. The concentration of caprolactam units in the PA66 / 6 copolymer may be, for example, between 0 and 18% by weight, between 3% and 21% by weight, between 6% and 24% by weight, between 9% and 27% by weight, or between 12% and 30% by weight. The impact resistance of the film may be in the range of, for example, 9.6N to 15.6N, 10.6N to 16.6N, 11.6N to 17.6N, 12.6N to 18.6N, or 13.6N to 19.6N.

[0067]

[0070] In some embodiments, a provided polymer film comprises 14% to 46% by weight of a PA66 / 6 copolymer having a melting point in the range of 200°C to 255°C and exhibits a heat shrinkage of between 0 and 2%. The concentration of the PA66 / 6 copolymer in the film may be, for example, in the range of 15% to 45% by weight, 15% to 33% by weight, 18% to 36% by weight, 21% to 39% by weight, 24% to 42% by weight, or 27% to 45% by weight. The melting point of the PA66 / 6 copolymer in the film may be, for example, in the range of 200°C to 233°C, 205.5°C to 238.5°C, 211°C to 244°C, 216.5°C to 249.5°C, or 222°C to 255°C. The heat shrinkage of the film may be, for example, between 0 and 1.2%, between 0.2% and 1.4%, between 0.4% and 1.6%, between 0.6% and 1.8%, or between 0.8% and 2%.

[0068] Preparation method

[0071] In another aspect, a method for preparing a polymer film is disclosed. The method includes providing a PA6 polymer and a PA66 / 6 copolymer. These polyamides can be any of those disclosed herein. In some embodiments, The method further comprises providing one or more heat stabilizers, lubricants, antiblocking agents, and / or additional copolymers. In some embodiments, the method further comprises selecting the type of PA6 polymer, PA66 / 6 copolymer, heat stabilizer, lubricant, antiblocking agent, and / or additional copolymer to impart desired mechanical properties to the resulting polyamide composition.

[0069]

[0072] The method further comprises blending a PA6 polymer and a PA66 / 6 copolymer to create a polyamide composition or mixture having a PA66 / 6 copolymer concentration greater than or equal to 15 wt%. In some embodiments, the presence of the PA66 / 6 copolymer additive in the polyamide composition of the film results in slower crystallization observed in the composition. This slower crystallization provides a larger window of time during which the mixture can be more easily processed into a film in the subsequent step. In some embodiments, the method further comprises blending one or more heat stabilizers, lubricants, antiblocking agents, and / or additional copolymers into the polyamide composition. In some embodiments, the method further comprises selecting the amounts of PA6 polymer, PA66 / 6 copolymer, heat stabilizer, lubricant, antiblocking agent, and / or additional copolymer to impart desired mechanical properties to the resulting polyamide composition. As used herein, the term "blending" is intended to encompass either the addition of the materials themselves to the composition or the in situ formation of the materials in the composition. In some embodiments, two or more materials to be combined with the composition are added simultaneously via a masterbatch.

[0070]

[0073] The method further includes casting the prepared polyamide composition to form a film. In some embodiments, casting includes extruding the polyamide composition at a selected extrusion temperature. The extrusion temperature may be, for example, in the range of 235°C to 295°C, e.g., 235°C to 271°C, 241°C to 277°C, 247°C to 283°C, 253°C to 289°C, or 259°C to 295°C. In terms of the upper limit, the extrusion temperature may be less than 295°C, e.g., less than 289°C, less than 283°C, less than 277°C, less than 271°C, less than 265°C, less than 259°C, less than 253°C, less than 247°C, or less than 241°C. In terms of the lower limit, the extrusion temperature may be greater than 235° C., e.g., greater than 241° C., greater than 247° C., greater than 253° C., greater than 259° C., greater than 265° C., greater than 271° C., greater than 277° C., greater than 283° C., or greater than 289° C. Higher extrusion temperatures, e.g., greater than 295° C., and lower extrusion temperatures, e.g., less than 235° C., are also contemplated.

[0071]

[0074] The method further includes a step of stretch-orienting the formed film, thereby preparing a polymer film. In some embodiments, the stretch-orienting step includes preheating the formed film for a selected preheating time and at a selected preheating temperature. The preheating time can be selected to be sufficiently low to enable smooth film stretching in the subsequent stretching step. The preheating time may be, for example, in the range of 2 to 10 seconds, e.g., 2 to 6.8 seconds, 2.8 to 7.6 seconds, 3.6 to 8.4 seconds, 4.4 to 9.2 seconds, or 5.2 to 10 seconds. In terms of the upper limit, the preheating time may be less than 10 seconds, e.g., less than 9.2 seconds, less than 8.4 seconds, less than 7.6 seconds, less than 6.8 seconds, less than 6 seconds, less than 5.2 seconds, less than 4.4 seconds, less than 3.6 seconds, or less than 2.8 seconds. In terms of the lower limit, the preheat time may be greater than 2 seconds, e.g., greater than 2.8 seconds, greater than 3.6 seconds, greater than 4.4 seconds, greater than 5.2 seconds, greater than 6 seconds, greater than 6.8 seconds, greater than 7.6 seconds, greater than 8.4 seconds, or greater than 9.2 seconds. Longer preheat times, e.g., greater than 10 seconds, and shorter preheat times, e.g., less than 2 seconds, are also contemplated.

[0072]

[0075] The preheat temperature should be selected low enough to minimize both pre-crystallization of the polyamide composition and the concomitant introduction of instabilities into the subsequent film stretching step. The preheating temperature may be, for example, in the range of 35°C to 115°C, e.g., 35°C to 83°C, 43°C to 91°C, 51°C to 99°C, 59°C to 107°C, or 67°C to 115°C. In terms of the upper limit, the preheating temperature may be less than 115°C, e.g., less than 107°C, less than 99°C, less than 91°C, less than 83°C, less than 75°C, less than 67°C, less than 59°C, less than 51°C, or less than 43°C. In terms of the lower limit, the preheating temperature may be greater than 35°C, e.g., greater than 43°C, greater than 51°C, greater than 59°C, greater than 67°C, greater than 75°C, greater than 83°C, greater than 91°C, greater than 99°C, or greater than 107°C. Lower preheating temperatures, e.g., less than 35°C, are also contemplated.

[0073]

[0076] Alternatively, the preheating temperature can be selected to be sufficiently high to accommodate a film production line having a shorter preheating time and / or a lower amount of force. The preheating temperature may be, for example, in the range of 150°C to 250°C, e.g., 150°C to 210°C, e.g., 160°C to 220°C, 170°C to 230°C, 180°C to 240°C, or 190°C to 250°C. In terms of the upper limit, the preheating temperature may be less than 250°C, e.g., less than 240°C, less than 230°C, less than 220°C, less than 210°C, less than 200°C, less than 190°C, less than 180°C, less than 170°C, or less than 160°C. In terms of the lower limit, the preheat temperature may be greater than 150° C., e.g., greater than 160° C., greater than 170° C., greater than 180° C., greater than 190° C., greater than 200° C., greater than 210° C., greater than 220° C., greater than 230° C., or greater than 240° C. Higher preheat temperatures, e.g., greater than 250° C., are also contemplated.

[0074]

[0077] In some embodiments, the stretch-orienting step includes stretching the formed film at a selected stretching temperature. The stretching temperature may be, for example, in the range of 70°C to 250°C, e.g., 70°C to 178°C, 88°C to 196°C, 106°C to 214°C, 124°C to 232°C, or 142°C to 250°C. In terms of the upper limit, the stretching temperature may be less than 250°C, e.g., less than 232°C, less than 214°C, less than 196°C, less than 178°C, less than 160°C, less than 142°C, less than 124°C, less than 106°C, or less than 88°C. In terms of the lower limit, the stretching temperature may be greater than 70°C, e.g., greater than 88°C, greater than 106°C, greater than 124°C, greater than 142°C, greater than 160°C, greater than 178°C, greater than 196°C, greater than 214°C, or greater than 232°C. Higher stretching temperatures, eg, above 250°C, and lower stretching temperatures, eg, below 70°C, are also contemplated.

[0075]

[0078] In some embodiments, the stretch-orienting step includes stretching the formed film at a selected stretch ratio. The presence of the PA66 / 6 copolymer additive in the polyamide composition advantageously does not significantly negatively affect the stretch ratio of the polymer film during preparation and processing. The provided polymer film can be oriented by stretching the film in the machine direction at a machine direction stretch ratio ranging from 3 to 3.8, e.g., 3 to 3.48, 3.08 to 3.56, 3.16 to 3.64, 3.24 to 3.72, or 3.32 to 3.8. The film can be stretched at a machine direction stretch ratio ranging from 3.2 to 3.5, e.g., 3.2 to 3.28, 3.23 to 3.41, 3.26 to 3.44, 3.29 to 3.47, or 3.32 to 3.5. In terms of an upper limit, the machine direction stretch ratio may be less than 3.8, e.g., less than 3.72, less than 3.64, less than 3.56, less than 3.5, less than 3.47, less than 3.44, less than 3.41, less than 3.38, less than 3.35, less than 3.32, less than 3.29, less than 3.26, less than 3.23, less than 3.2, less than 3.16, or less than 3.08. In terms of a lower limit, the machine direction stretch ratio may be greater than 3, e.g., greater than 3.08, greater than 3.16, greater than 3.2, greater than 3.23, greater than 3.26, greater than 3.29, greater than 3.32, greater than 3.35, greater than 3.38, greater than 3.41, greater than 3.44, greater than 3.47, greater than 3.5, greater than 3.56, greater than 3.64, or greater than 3.72. Higher machine direction stretch ratios, for example, greater than 3.8, and lower machine direction stretch ratios, for example, less than 3, are also contemplated.

[0076]

[0079] The provided polymeric films can be oriented, for example, by stretching the film in the transverse direction at a transverse stretch ratio ranging from 3.1 to 5, e.g., from 3.1 to 4.24, from 3.29 to 4.43, from 3.48 to 4.62, from 3.67 to 4.81, or from 3.86 to 5. The films can be stretched at a transverse stretch ratio ranging from 3.3 to 3.7, e.g., from 3.3 to 3.54, from 3.34 to 3.58, from 3.38 to 3.62, from 3.42 to 3.66, or from 3.46 to 3.7. In terms of an upper limit, the transverse stretch ratio may be less than 5, for example, less than 4.81, less than 4.62, less than 4.43, less than 4.24, less than 4.09, less than 3.98, less than 3.87, less than 3.76, less than 3.7, less than 3.66, less than 3.62, less than 3.58, less than 3.54, less than 3.5, less than 3.46, less than 3.42, less than 3.38, less than 3.34, less than 3.3, or less than 3.21. In terms of the lower limit, the transverse stretch ratio may be greater than 3.1, e.g., greater than 3.21, greater than 3.3, greater than 3.34, greater than 3.38, greater than 3.42, greater than 3.46, greater than 3.5, greater than 3.54, greater than 3.58, greater than 3.62, greater than 3.66, greater than 3.7, greater than 3.76, greater than 3.87, greater than 3.98, greater than 4.09, greater than 4.24, greater than 4.43, greater than 4.62, or greater than 4.81. Higher transverse stretch ratios, e.g., greater than 5, and lower transverse stretch ratios, e.g., less than 3.1, are also contemplated.

[0077]

[0080] In some cases, polymeric films are effectively produced with a machine direction relaxation in the range of 0% to 10%, e.g., 0% to 7%, 1% to 7%, 0% to 5%, or 1% to 5%. In terms of the upper limit, the machine direction relaxation may be less than 10%, e.g., less than 7%, less than 5%, or less than 3%.

[0078]

[0081] In some cases, polymeric films are effectively produced with a transverse relaxation in the range of 0% to 20%, e.g., 1% to 15%, 3% to 15%, 3% to 12%, or 5% to 12%. In terms of the upper limit, the machine direction relaxation may be less than 20%, e.g., less than 15%, less than 12%, or less than 10%.

[0079]

[0082] In some cases, polymeric films are effectively produced with a final machine direction and / or transverse direction stretch in the range of 0% to 10%, e.g., 0% to 7%, 1% to 7%, 1% to 5%, or 2% to 4%. In terms of the upper limit, the machine direction relaxation may be less than 10%, e.g., less than 7%, less than 5%, or less than 4%.

[0080]

[0083] In some embodiments, the stretch-orienting step comprises simultaneously stretching the formed film in both the machine direction and the transverse direction. Such simultaneous stretching can be selected to accommodate film production lines having shorter preheating times and / or higher temperatures than those disclosed herein. In an alternative embodiment, the stretch-orienting step comprises sequentially stretching the formed film in the machine direction and the transverse direction. The machine direction film stretching can be performed before the transverse direction film stretching. The transverse direction film stretching can be performed before the machine direction film stretching. Such sequential stretching can be selected to accommodate film production lines having longer preheating times and / or lower temperatures than those disclosed herein. In some embodiments, sequential stretching of the formed film at a lower temperature allows for a higher stretch ratio, resulting in a film with higher puncture resistance.

[0081]

[0084] In some embodiments, the stretch-orienting step includes annealing the formed film at a selected annealing temperature. The annealing temperature may be, for example, in the range of 180°C to 240°C, e.g., 180°C to 216°C, 186°C to 222°C, 192°C to 228°C, 198°C to 234°C, or 204°C to 240°C. In terms of the upper limit, the annealing temperature may be less than 240°C, e.g., less than 234°C, less than 228°C, less than 222°C, or less than 240°C. It may be less than 16° C., less than 210° C., less than 204° C., less than 198° C., less than 192° C., or less than 186° C. In terms of the lower limit, the annealing temperature may be greater than 180° C., e.g., greater than 186° C., greater than 192° C., greater than 198° C., greater than 204° C., greater than 210° C., greater than 216° C., greater than 222° C., greater than 228° C., or greater than 234° C. Higher annealing temperatures, e.g., greater than 240° C., and lower annealing temperatures, e.g., less than 180° C., are also contemplated. [Example]

[0082]

[0085] The present disclosure will be better understood in consideration of the following non-limiting examples, which are intended for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way.

[0083]

[0086] The polymer films of Examples 1-3 were prepared using the compositions and processing parameters shown in Table 1. The composition percentages are expressed as weight percent. Examples 1-3 were produced as biaxially oriented films (although other films, e.g., machine direction oriented films, are within the scope of this application).

[0084]

[0087] The PA6 polymer had a heat distortion temperature of less than 190°C and a melting point of approximately 220°C. The PA66-s-6 statistical polymer had a heat distortion temperature as disclosed herein, e.g., in the range of 190°C to 300°C, and a melting point as disclosed herein, e.g., in the range of 190°C to 300°C. The resulting polymer film advantageously had a relatively high heat distortion temperature and melting point as disclosed herein. The resulting polymer film advantageously had a relative viscosity as disclosed herein, e.g., of 0.5 to 10.0.

[0085] [Table 1]

[0086]

[0088] For each of Examples 1-3, several rolls of film were prepared, each having a length of 500 meters and a thickness of 15 micrometers. Importantly, all examples exhibited similar stretch ratios to each other and to films prepared using 100% PA6 (data not shown). These results demonstrate that the introduction of PA66 / 6 copolyamide as a film component does not undesirably increase the overall film's maximum stretch ratio and heat shrinkage, while providing other synergistic performance properties. For each of the examples, the cast film quality was excellent, demonstrating the high processing flexibility and robustness of the film compositions provided herein.

[0087]

[0089] Additional exemplary and comparative polymer films were prepared using polyamide compositions containing various relative amounts of PA6 and PA66 / 6, ranging from 100% PA6 to 100% PA66 / 6, as shown in Table 2. The composition percentages are expressed as weight percent. The mechanical performance properties of these films were measured as described herein, and the results of these measurements are shown in Figures 1-4.

[0088] [Table 2]

[0089]

[0090] The graph in Figure 1 shows a plot of the puncture resistance of polymer films containing increasing concentrations of PA66 / 6 copolymer additive relative to PA6 polymer. The results presented in the graph demonstrate that the addition of a selected amount of PA66 / 6 copolymer to the films described herein beneficially increases the puncture resistance of the film compared to conventional polymer films containing only PA6 in a polyamide composition. When used in packaging applications, for example, this improvement provides films that are less susceptible to damage from puncture.

[0090]

[0091] The graph in Figure 2 shows a plot of elongation for polymer films with increasing concentrations of PA66 / 6 copolymer additive relative to PA6 polymer. The results presented in the graph demonstrate that the addition of selected amounts of PA66 / 6 copolymer to the films described herein beneficially increases the elongation of the films compared to conventional polymer films containing only PA6 in their polyamide composition. When used in packaging applications, for example, this improvement can result in the provided films being less susceptible to damage from tearing or puncturing.

[0091]

[0092] The graph in Figure 3 shows a plot of the tensile strength of polymer films containing increasing concentrations of PA66 / 6 copolymer additive relative to PA6 polymer. The results presented in the graph indicate that the addition of selected amounts of PA66 / 6 copolymer to the films described herein does not significantly negatively affect the tensile strength of the film compared to conventional polymer films containing only PA6 in a polyamide composition. This allows the provided film to maintain its ability to resist breakage due to tensile forces.

[0092]

[0093] The graph in Figure 4 shows a plot of the tensile modulus of polymer films containing increasing concentrations of PA66 / 6 copolymer additive relative to PA6 polymer. The results presented in the graph show that the addition of selected amounts of PA66 / 6 copolymer to the films described herein beneficially reduces the tensile modulus of the film compared to conventional polymer films containing only PA6 in a polyamide composition. This improvement can make the resulting film more amenable to processing steps such as film stretching or film thermoforming.

[0093]

[0094] In some cases, PA66 / 6 copolymer (alone) performs satisfactorily, however, it exhibits reduced tensile modulus performance and, importantly, becomes very cost-ineffective when used in very large quantities.

[0094] Embodiment

[0095] The following embodiments are contemplated: All combinations of features and embodiments are contemplated.

[0095]

[0096] Embodiment 1: A polymeric film comprising a polyamide composition, the polyamide composition being less than 86 wt.% PA6 polymer; and more than 14 wt.% PA66 / 6 copolyester. a polymer film comprising: a polymer; and wherein the film exhibits a puncture resistance of greater than 800 N / mm, for example greater than 850 N / mm, as measured using a 1 mm probe radius according to standard test method ASTM F1306-16(2016).

[0096]

[0097] Embodiment 2: The embodiment of embodiment 1, wherein the polymer film comprises 15% to 85% by weight, e.g., 55% to 85% by weight, of PA6 polymer; and 15% to 85% by weight, e.g., 55% to 85% by weight, of PA66 / 6 copolymer.

[0097]

[0098] Embodiment 3: The embodiment of embodiment 1 or 2, wherein the PA66 / 6 copolymer is a statistical copolymer, such as PA66-s-6.

[0098]

[0099] Embodiment 4: The embodiment of any one of embodiments 1 to 3, wherein the relative viscosity of the polyamide composition ranges from 60 to 250 as measured according to standard test method ASTM D789-19(2019).

[0099]

[0100] Embodiment 5: The PA66 / 6 copolymer is more than 70% by weight of adipic acid-hydroxybenzoate. 5. The embodiment of any one of embodiments 1-4, comprising hexamethylenediamine units; and less than 30% by weight of caprolactam units.

[0100]

[0101] Embodiment 6: The melting point of the PA66 / 6 copolymer is in the range of 200°C to 255°C. The embodiment described in any one of embodiments 1 to 5.

[0101]

[0102] Embodiment 7: The PA66 / 6 copolymer is 75% to 85% by weight of adipic acid. 7. The embodiment of any one of the preceding embodiments, wherein the PA66 / 6 copolymer comprises: acid-hexamethylenediamine units; and 15% to 25% by weight of caprolactam units; and the melting point of the PA66 / 6 copolymer is in the range of 215°C to 223°C.

[0102]

[0103] Embodiment 8: The PA66 / 6 copolymer is 80% to 90% by weight of adipic acid. 7. The embodiment of any one of embodiments 1 to 6, wherein the PA66 / 6 copolymer comprises: acid-hexamethylenediamine units; and 10% to 20% by weight of caprolactam units; and the melting point of the PA66 / 6 copolymer is in the range of 230°C to 238°C.

[0103]

[0104] Embodiment 9: The polyamide composition comprises less than 90% by weight of caprolactam units. , an embodiment according to any one of embodiments 1 to 8.

[0104]

[0105] Embodiment 10: The polyamide composition is 55% to 90% by weight of caprolactam The embodiment of any one of embodiments 1 to 9, comprising a unit.

[0105]

[0106] Embodiment 11: Adipic acid-hexamethylenediamine in PA66 / 6 copolymer 11. The embodiment of any one of embodiments 1 to 10, wherein the weight ratio of amine units to caprolactam units ranges from 2:1 to 16:1.

[0106]

[0107] Embodiment 12: PA6 polymer and PA66 / 6 copolymer in a polyamide composition 12. The embodiment of any one of embodiments 1 to 11, wherein the weight ratio of hydroxybenzoates to hydroxybenzoates is in the range of 1:1 to 6:1.

[0107]

[0108] Embodiment 13: Caprolactam units and adipic acid-hexyl esters in a polyamide composition 13. The embodiment of any one of embodiments 1-12, wherein the weight ratio of sammethylenediamine units ranges from 1:1 to 9:1.

[0108]

[0109] Embodiment 14: The film is resistant to corrosion by standard test method ASTM D882-18(2018 14. The embodiment of any of the preceding claims, wherein the film exhibits a transverse elongation of greater than 85%, such as greater than 88%, as measured according to JIS K 10014.

[0109]

[0110] Embodiment 15: The film is resistant to corrosion by standard test method ASTM D1709-16ae1( 15. The embodiment of any one of embodiments 1-14, wherein the impact resistance is greater than 9.6 N as measured according to (2016) FCC Rules.

[0110]

[0111] Embodiment 16: The film is resistant to corrosion by standard test method ASTM D882-18(2018 16. The embodiment of any one of embodiments 1-15, wherein the polymer exhibits a transverse tensile strength, as measured according to (a) above 250 MPa.

[0111]

[0112] Embodiment 17: The film is resistant to corrosion by standard test method ASTM D882-18(2018 17. The embodiment of any one of the preceding embodiments, wherein the polymer exhibits a transverse tensile modulus, as measured according to (a) above, of less than 3800 MPa, such as less than 3500 MPa.

[0112]

[0113] Embodiment 18: The polyamide composition is 55% to 85% by weight of PA6 polymer. and 15% to 45% by weight of PA66 / 6 copolymer; wherein the film exhibits a puncture resistance of greater than 1000 N / mm and a cross direction elongation of greater than 90%.

[0113]

[0114] Embodiment 19: PA6 polymer with a polyamide composition of 55% to 85% by weight and 15% to 45% by weight of PA66 / 6 copolymer; the film exhibits a puncture resistance of greater than 900 N / mm and a cross direction elongation of greater than 95%; and the relative viscosity of the polyamide composition is in the range of 70 to 130.

[0114]

[0115] Embodiment 20: A PA6 polymer having a polyamide composition of 55% to 85% by weight. and 15% to 45% by weight of PA66 / 6 copolymer; the film exhibits a puncture resistance of greater than 900 N / mm and a cross direction elongation of greater than 95%; and the relative viscosity of the polyamide composition is in the range of 100 to 200.

[0115]

[0116] Embodiment 21: A composition comprising one or more heat stabilizers, one or more lubricants, and one 21. The embodiment of any one of embodiments 1-20, further comprising one or more additives selected from the group consisting of anti-blocking agents.

[0116]

[0117] Embodiment 22: The one or more anti-blocking agents are selected from diatomaceous earth and silica microparticles. 22. The embodiment of embodiment 21, wherein the compound is selected from the group consisting of:

[0117]

[0118] Embodiment 23: At least one of the one or more heat stabilizers comprises copper. 23. The embodiment of claim 21 or 22.

[0118]

[0119] Embodiment 24: Further comprising one or more additional polyamide copolymers. The embodiment described in any one of embodiments 1 to 23.

[0119]

[0120] Embodiment 25: The one or more additional polyamide copolymers are PA66 / 25. The embodiment of embodiment 24, wherein the PEG-140 is selected from the group consisting of PA66 / 6,10, PA6,10, PA66 / 6,12 and PA6,12.

[0120]

[0121] Embodiment 26: The film is stretched in the machine direction at a machine direction stretch ratio in the range of 3 to 3.8. and by stretching in the transverse direction at a transverse stretch ratio in the range of 3.1 to 5. 26. The embodiment of any one of embodiments 1 to 25, wherein the

[0121]

[0122] Embodiment 27: Any of embodiments 1 to 26, having a heat shrinkage of less than 2%. 1. The embodiment described in

[0122]

[0123] Embodiment 28: A method according to claim 1, wherein the polymer film does not contain PA66 / 6 copolymer. 28. The embodiment of any one of embodiments 1 to 27, wherein the polymer film exhibits a maximum stretch ratio equal to or less than the maximum stretch ratio of the film to be stretched, and the polymer film exhibits a heat shrinkage ratio equal to or less than the heat shrinkage of the corresponding film.

[0123]

[0124] Embodiment 29: The film has a thickness of less than 26 micrometers, 29. The embodiment of any one of embodiments 1-28, wherein the tensile strength exhibits a penetration resistance of greater than 825 N / mm.

[0124]

[0125] Embodiment 30: A polyamide composition having a total caprolactam unit concentration of 26 times or more. 30. The embodiment of any one of embodiments 1 to 29, wherein the amount ranges from 74% to 74% by weight.

[0125]

[0126] Embodiment 31: Total caprolactam units in non-PA6 polymers / copolymers The embodiment of any one of embodiments 1 to 30, wherein the concentration is in the range of 5% to 40% by weight.

[0126]

[0127] Embodiment 32: A method for preparing a polymer film, comprising: providing a PA6 polymer and a PA66 / 6 copolymer; blending the PA6 polymer and the PA66 / 6 copolymer to form a polyamide composition containing greater than or equal to 15 wt.% PA66 / 6; casting the formed polyamide composition to form a film; and stretch-orienting the formed film to thereby prepare a polymer film, wherein the film exhibits a puncture resistance of greater than 850 N / mm.

[0127]

[0128] Embodiment 33: The oriented film of any one of embodiments 1 to 32. Items including.

[0128]

[0129] While the present invention has been described in detail, modifications within the spirit and scope of the present invention will be readily apparent to those skilled in the art in light of the foregoing discussion, the relevant knowledge of the art, and the remarks discussed above in connection with the Background and Detailed Description, all of the disclosures of which are incorporated herein by reference. Furthermore, it should be understood that aspects of the present invention, portions of various embodiments, and various features described below and / or in the appended claims may be combined or interchanged, either in whole or in part. In the foregoing description of various embodiments, embodiments referring to separate embodiments may be combined with other embodiments as appropriate, as recognized by those skilled in the art. Furthermore, those skilled in the art will recognize that the foregoing description is by way of example only and is not intended to limit the invention. The present invention includes the following embodiments. [1] A film comprising a polyamide composition, wherein the polyamide composition is less than 86% by weight of PA6 polymer, preferably 15% to 85% by weight of PA6 polymer, PA66 / 6 copolymer, which is more than 14% by weight of PA66 / 6 copolymer, preferably 15% to 85% by weight of PA66 / 6 copolymer, preferably a statistical copolymer; and optionally PA66 / 6,10, PA6,10, PA66 / 6,12 or PA6,12, or a combination thereof; and Optionally, diatomaceous earth and silica fine particles Including, 1. A film, wherein the film exhibits a puncture resistance of greater than 800 N / mm as measured in accordance with standard test method ASTM F1306-16(2016). [2] The polymer film according to [1], which is a biaxially stretched film. [3] The polymer film according to [1] or [2], which has a heat distortion temperature of more than 190°C. [4] A polymer film according to any one of [1] to [3], wherein the film has a thickness of less than 26 micrometers and exhibits a puncture resistance of more than 825 N / mm. [5] The polymer film according to any one of [1] to [4], wherein the total concentration of caprolactam units in the polyamide composition is in the range of 26% by weight to 74% by weight. [6] The polymer film according to any one of [1] to [5], wherein the total concentration of caprolactam units in the non-PA6 polymer / copolymer is in the range of 5% by weight to 40% by weight. [7] PA66 / 6 copolymer, More than 70% by weight of adipic acid-hexamethylenediamine units, preferably 75% to 85% by weight of adipic acid-hexamethylenediamine units, and Less than 30% by weight of caprolactam units, preferably 15% to 25% by weight of caprolactam units Including, The polymer film according to any one of [1] to [6], wherein the melting point of the PA66 / 6 copolymer is in the range of 215°C to 223°C. [8] PA66 / 6 copolymer, 80% to 90% by weight of adipic acid-hexamethylenediamine units, and 10% to 20% by weight of caprolactam units Including, The polymer film according to any one of [1] to [6], wherein the melting point of the PA66 / 6 copolymer is in the range of 230°C to 238°C. [9] A polymer film according to any of [1] to [8], exhibiting a transverse elongation of greater than 85% as measured in accordance with standard test method ASTM D882-18(2018), and / or an impact resistance of greater than 9.6 N as measured in accordance with standard test method ASTM D1709-16ae1(2016), and / or a transverse tensile strength of greater than 250 MPa as measured in accordance with standard test method ASTM D882-18(2018), or a transverse tensile modulus of less than 3800 MPa as measured in accordance with standard test method ASTM D882-18(2018).

[10] The polyamide composition, 55% to 85% by weight of a PA6 polymer, and 15% to 45% by weight of PA66 / 6 copolymer Including, 10. The polymer film according to any one of [1] to [9], wherein the film exhibits a puncture resistance of more than 850 N / mm and a transverse elongation of more than 90%.

[11] The polymer film according to any one of [1] to

[10] , which is oriented by stretching in the machine direction at a machine direction stretch ratio in the range of 3 to 3.8 and by stretching in the transverse direction at a transverse direction stretch ratio in the range of 3.1 to 5.

[12] The polymer film according to any one of [1] to

[11] , having a heat shrinkage rate of less than 2%.

[13] A polymer film according to any one of [1] to

[12] , which exhibits a maximum stretch ratio equal to or less than the maximum stretch ratio of a corresponding film not containing PA66 / 6 copolymer and exhibits a heat shrinkage ratio equal to or less than the heat shrinkage ratio of the corresponding film.

[14] A method for preparing a polymer film, comprising: providing a PA6 polymer and a PA66 / 6 copolymer; blending a PA6 polymer and a PA66 / 6 copolymer to form a polyamide composition containing greater than or equal to 15 wt.% PA66 / 6; casting the resulting polyamide composition to form a film; and stretch-orienting the formed film to thereby prepare a polymer film, wherein the polymer film exhibits a puncture resistance of greater than 850 N / mm. A method comprising:

[15] An article comprising the film according to any one of [1] to

[14] , wherein the film is biaxially oriented.

Claims

1. A film comprising a polyamide composition, the polyamide composition comprising: 15% to 85% by weight of a PA6 polymer, and 15% to 85% by weight of PA66 / 6 copolymer, wherein the weight percent is based on the total polyamide composition; the total amount of caprolactam units in the PA66 / 6 copolymer is in the range of 5% to 40% by weight, 1. A film, wherein the film exhibits a puncture resistance of greater than 800 N / mm as measured according to standard test method ASTM F1306-16(2016).

2. A polymer film as described in claim 1, wherein the PA66 / 6 copolymer is a statistical copolymer.

3. A polymer film as described in claim 1, which is a biaxially stretched film.

4. A polymer film as described in claim 1 having a heat distortion temperature greater than 190°C.

5. A polymer film as described in claim 1, wherein the film has a thickness of less than 26 micrometers and exhibits a penetration resistance of greater than 825 N / mm.

6. A polymer film as described in claim 1, wherein the total amount of caprolactam units in the polyamide composition is in the range of 26% by weight to 74% by weight.

7. The PA66 / 6 copolymer, 75% to 85% by weight of adipic acid-hexamethylenediamine units, and 15% to 25% by weight of caprolactam units wherein the weight percent is based on the total PA66 / 6 copolymer, 2. The polymeric film of claim 1, wherein the melting point of the PA66 / 6 copolymer is in the range of 215°C to 223°C.

8. The PA66 / 6 copolymer, 80% to 90% by weight of adipic acid-hexamethylenediamine units, and 10% to 20% by weight of caprolactam units wherein the weight percent is based on the total PA66 / 6 copolymer, 2. The polymeric film of claim 1, wherein the melting point of the PA66 / 6 copolymer is in the range of 230°C to 238°C.

9. The polymer film of claim 1, exhibiting a transverse elongation of greater than 85% as measured in accordance with standard test method ASTM D882-18(2018).

10. The polymer film of claim 1, exhibiting an impact resistance of greater than 9.6 N as measured in accordance with standard test method ASTM D1709-16ae1(2016).

11. The polymer film of claim 1, exhibiting a transverse tensile strength greater than 250 MPa as measured in accordance with standard test method ASTM D882-18(2018) or a transverse tensile modulus less than 3800 MPa as measured in accordance with standard test method ASTM D882-18(2018).

12. The polyamide composition, 55% to 85% by weight of a PA6 polymer, and 15% to 45% by weight of PA66 / 6 copolymer Including, 10. The polymer film of claim 1, wherein the film exhibits a puncture resistance of greater than 850 N / mm and a cross direction elongation of greater than 90%.

13. The polymer film of claim 1, further comprising diatomaceous earth and silica microparticles.

14. The polymer film of claim 1, oriented by stretching in the machine direction at a machine direction stretch ratio in the range of 3 to 3.8 and by stretching in the transverse direction at a transverse direction stretch ratio in the range of 3.1 to 5.

15. The polymer film of claim 1, having a heat shrinkage rate of less than 2%.

16. A polymer film as described in claim 1, which exhibits a maximum stretch ratio less than or equal to the maximum stretch ratio of a corresponding film not containing PA66 / 6 copolymer and exhibits a heat shrinkage ratio less than or equal to the heat shrinkage ratio of the corresponding film.

17. A method for preparing a polymer film, comprising: providing 15 wt% to 85 wt% PA6 polymer and 15 wt% to 85 wt% PA66 / 6 copolymer, the wt% being based on the total polyamide composition and the total caprolactam units in the PA66 / 6 copolymer being in the range of 5 wt% to 40 wt%; blending a PA6 polymer and a PA66 / 6 copolymer to form a polyamide composition; casting the resulting polyamide composition to form a film; and Stretch-orienting the formed film to thereby prepare a polymer film, wherein the polymer film exhibits a puncture resistance of greater than 850 N / mm.

18. An article comprising the film of claim 1, wherein the film is biaxially oriented.

19. A film comprising a polyamide composition, the polyamide composition comprising: 15% to 70% by weight of a PA6 polymer, and 30% to 85% by weight of PA66 / 6 copolymer, wherein the weight percent is based on the total polyamide composition; The total caprolactam content in the polyamide composition is in the range of 26% by weight to 74% by weight, 1. A film, wherein the film exhibits a puncture resistance of greater than 800 N / mm as measured according to standard test method ASTM F1306-16(2016).

20. The polymer film of claim 19, further comprising diatomaceous earth and silica microparticles.

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