Ionomers of ethylene glycol copolymers with improved UV stability

Abstract

This disclosure relates to a composition comprising an ionomer, a triazine-based UV absorber, and a hindered amine light stabilizer, the ionomer comprising an ethylene copolymer comprising a polymerization product of 60 wt% to 99 wt% ethylene and 1 wt% to 6 wt% carboxylic acid monomers, wherein the ethylene copolymer is at least partially neutralized by a metal cation comprising zinc or sodium, provided that when the metal cation comprises zinc, at most 75 mol% of the carboxylic acid monomers are neutralized.

Description

Cross-reference to related applications

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 594,481, filed on October 31, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] This disclosure generally relates to ionomers of ethylene glycol copolymers, and more particularly to ionomers of ethylene glycol copolymers that provide improved ultraviolet (UV) stability. Background Technology

[0003] Ionomers are commonly used materials in a variety of applications because they offer higher tensile strength, greater transparency, better abrasion resistance, and higher stiffness than precursor acid copolymers. For example, ionomers of ethylene glycol copolymers have been found to be useful in many applications, such as food packaging, foamed components, injection-molded parts (e.g., cosmetic containers), and golf ball components. Summary of the Invention

[0004] While ionomers can be used in many applications, many exhibit poor stability in the presence of ultraviolet (UV) light. This poor stability is particularly problematic for ionomers exposed to sunlight in outdoor applications, including those used to construct decks and other structures, as well as those used in outdoor furniture. Poor UV stability can lead to degradation, loss of mechanical properties, and discoloration in articles containing ionomers. Traditional methods for improving the UV stability of ionomers involve using conventional UV stabilizers designed to protect polyethylene. Unfortunately, this approach is largely ineffective for ionomers because the acid functional groups of the ionomer degrade or interact with conventional UV stabilizers, impairing their effectiveness. In some cases, the interaction between the UV stabilizer and the acid functional groups of the ionomer can even degrade the UV stability of the ionomer. Therefore, there is a need for ionomers with improved UV resistance.

[0005] The embodiments disclosed herein address this need for ionomers with improved UV resistance by utilizing triazine-based UV absorbers and hindered amine light stabilizers.

[0006] According to one embodiment, the composition includes an ionomer, a triazine-based UV absorber, and a hindered amine light stabilizer. The ionomer includes an ethylene copolymer comprising a polymerization product of 60 wt% to 99 wt% ethylene and 1 wt% to 6 wt% carboxylic acid monomers, wherein the ethylene copolymer is at least partially neutralized by a metal cation, including zinc or sodium, provided that when the metal cation includes zinc, at most 75 mol% of the carboxylic acid monomers are neutralized.

[0007] These and other features, aspects, and advantages will become better understood with reference to the following description and the appended claims.

[0008] Additional technical features and advantages of the examples described herein will be set forth in the following detailed description and will be apparent in part to those skilled in the art from the description or recognized by practice of the examples described herein, including the following detailed description and claims.

[0009] It should be understood that both the foregoing general description and the following detailed description describe various examples and are intended to provide an overview or framework for understanding the nature and characteristics of the claimed subject matter. Detailed Implementation

[0010] Specific embodiments of this application will now be described. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the subject matter to those skilled in the art.

[0011] The term "polymer" refers to a polymeric compound prepared by polymerizing monomers of the same or different types. Therefore, the general term polymer encompasses the term "homopolymer," which typically refers to a polymer prepared from only one type of monomer, and "copolymer," which refers to a polymer prepared from two or more different monomers. As used herein, the term "interpolymer" refers to a polymer prepared by polymerizing at least two different types of monomers. Therefore, the general term interpolymer includes copolymers or polymers prepared from more than two different types of monomers, such as terpolymers.

[0012] "Ethylene polymer" should be understood to mean a polymer comprising more than 50% by weight of units derived from ethylene monomers. This includes ethylene homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of ethylene polymers known in the art include, but are not limited to: low-density polyethylene (LDPE); linear low-density polyethylene (LLDPE); ultra-low-density polyethylene (ULDPE); very low-density polyethylene (VLDPE); single-point catalytic linear low-density polyethylene, including both linear low-density resins and substantially linear low-density resins (m-LLDPE); medium-density polyethylene (MDPE); and high-density polyethylene (HDPE).

[0013] "Recycled polymer" refers to a polymer that is incorporated into a product and subsequently remelted to form a recycled polymer. The term "recycled polymer" specifically refers to a mechanically recycled polymer, where the polymer is melted and re-incorporated into a new product. "Recycled polymer" does not include chemically recycled polymers, where the polymer is broken down into constituent monomers and incorporated into a new virgin polymer. The term "recycled polymer" encompasses both pre-consumer recycled polymers and post-consumer recycled polymers. Recycled polymers are defined in ISO 14021 7.8.1.1.

[0014] The terms "pre-consumer recycled polymer" and "post-industrial recycled polymer" refer to polymers including blends of polymers recovered from pre-consumer materials as defined by ISO 14021. Therefore, the general term "pre-consumer recycled polymer" includes blends of polymers recovered from materials transferred from waste streams during the manufacturing process. The general term "pre-consumer recycled polymer" does not include the reuse of materials generated in the process and capable of being recovered in the same process in which they are generated, such as reprocessing, regrinding, or waste. Pre-consumer recycled polymers are defined in ISO 14021 7.8.1.1.

[0015] As used herein, the term "post-consumer recycled" (or "PCR") refers to polymeric materials that include materials previously used in consumer or industrial applications (i.e., pre-consumer recycled polymers and post-industrial recycled polymers). PCRs are typically collected from recycling programs and recycling plants. Ethylene-based polymers in PCRs may include one or more ethylene-based polymers, such as LDPE, LLDPE, HDPE, or polyethylene. PCRs may contain one or more contaminants. Contaminants may be a result of the polymeric material's use prior to reuse. For example, contaminants may include paper, ink, food scraps, or other recycled materials other than polymers that can be generated from the recycling process. PCRs differ from virgin polymeric materials. Virgin polymeric materials, such as virgin polyethylene resins, do not include materials previously used in consumer or industrial applications. Virgin polymeric materials have not undergone, or have not otherwise undergone, a heating or molding process after the initial polymer manufacturing process. PCR resins have different physical, chemical, and flow properties compared to virgin polymeric resins, which in turn may present challenges in incorporating PCRs into commercial-use formulations. Post-consumer resins are defined in ISO 14021 7.8.1.1.

[0016] "Ethylene-based copolymers" are products of the polymerization reaction of ethylene with one or more unsaturated carboxylic acids.

[0017] The term “hindered amine light stabilizer” or “HALS” refers to sterically hindered amines, a class of compounds typically represented by 2,2,6,6-tetraalkylpiperidine.

[0018] Examples of compositions comprising ionomers will now be described in detail, the ionomers comprising an ethylene copolymer comprising 60 wt% to 99 wt% ethylene and 1 wt% to 6 wt% carboxylic acid monomers as polymerization products, wherein the ethylene copolymer is at least partially neutralized by a metal cation comprising zinc or sodium, provided that when the metal cation comprises zinc, at most 75 mol% of the carboxylic acid monomers are neutralized. The compositions also include a triazine-based UV absorber and a hindered amine light stabilizer.

[0019] The composition includes an ionomer. The composition may include 1% to 99% ionomer. In some examples, the composition may include 1% to 99% ionomer, 10% to 99% ionomer, 20% to 99% ionomer, 30% to 99% ionomer, or 40% to 99% ionomer.

[0020] Ionomers include ethylene-based copolymers. Ethylene-based copolymers comprise or are derived from 60 wt% to 99 wt% ethylene monomer. In some examples, the polymerization products include 60 wt% to 99 wt% ethylene, 60 wt% to 95 wt% ethylene, 60 wt% to 90 wt% ethylene, 70 wt% to 99 wt% ethylene, 70 wt% to 95 wt% ethylene, 70 wt% to 90 wt% ethylene, 80 wt% to 99 wt% ethylene, 80 wt% to 95 wt% ethylene, 80 wt% to 90 wt% ethylene, or 94 wt% to 99 wt% ethylene.

[0021] The vinyl acid copolymer comprises 1% to 6% by weight of a carboxylic acid monomer. The carboxylic acid monomer may be, for example, acrylic acid, methacrylic acid, or a combination thereof. In some examples, the vinyl acid copolymer comprises 1% to 6% by weight of a carboxylic acid monomer, 1% to 5% by weight of a carboxylic acid monomer, 2% to 6% by weight of a carboxylic acid monomer, 2% to 5% by weight of a carboxylic acid monomer, 4% to 6% by weight of a carboxylic acid monomer, 4% to 5% by weight of a carboxylic acid monomer, or 3% to 4% by weight of a carboxylic acid monomer.

[0022] Without being limited by theory, it is believed that a carboxylic acid monomer content of less than 6% by weight ensures that the ionomer, the resulting composition, and the articles made therefrom possess the desired properties, including scratch resistance and / or grease resistance. Conversely, compositions with a higher weight percentage of carboxylic acid monomers are believed to cause degradation of or interact with UV stabilizers, thereby reducing the effectiveness of the UV stabilizers.

[0023] Acetic acid copolymers can be prepared by standard free radical copolymerization, using high pressure, and in a continuous operation. Monomers are fed into the reaction mixture in proportions related to monomer activity and desired incorporation levels. This achieves a uniform, nearly random distribution of monomer units along the chain. Unreacted monomers can be recovered. Acetic acid copolymers can be polymerized according to the methods disclosed in U.S. Patents 3,404,134, 5,028,674, 6,500,888, and 6,518,365. In some embodiments, blends of two or more acetic acid copolymers can be used, provided that the aggregate composition and properties of the blend fall within the limits described above for acetic acid copolymers.

[0024] As described above, the ethylene glycol copolymer is at least partially neutralized by a metal cation (to form an ionomer). In some examples, the metal cation includes a zinc cation. In examples where the metal cation includes sodium, 40 mol% to 100 mol% of the carboxylic acid monomer is neutralized by a sodium cation. In examples where the metal cation includes sodium, 40 mol% to 100 mol%, 50 mol% to 100 mol%, 60 mol% to 100 mol%, 70 mol% to 100 mol%, 80 mol% to 100 mol%, 90 mol% to 100 mol%, 40 mol% to 90 mol%, 50 mol% to 90 mol%, 60 mol% to 90 mol%, 70 mol% to 90 mol%, 80 mol% to 90 mol%, 40 mol% to 80 mol%, 50 mol% to 80 mol%, 60 mol% to 80 mol%, 70 mol% to 80 mol%, 40 mol% to 70 mol%, 50 mol% to 70 mol%, 60 mol% to 70 mol%, 40 mol% to 60 mol%, 50 mol% to 60 mol%, or 40 mol% to 50 mol% of the carboxylic acid monomer is neutralized by the sodium cation.

[0025] In some examples, the metal cation includes zinc. When the metal cation includes zinc, up to 75 mol% of the carboxylic acid monomer is neutralized. In examples where the metal cation includes zinc, 40 mol% to 75 mol% of the carboxylic acid monomer is neutralized by the zinc cation. In examples where the metal cation includes zinc, 40 mol% to 75 mol%, 45 mol% to 75 mol%, 50 mol% to 75 mol%, 55 mol% to 75 mol%, 60 mol% to 75 mol%, 65 mol% to 75 mol%, 70 mol% to 75 mol%, 40 mol% to 70 mol%, 45 mol% to 70 mol%, 50 mol% to 70 mol%, 55 mol% to 70 mol%, 60 mol% to 70 mol%, 65 mol% to 70 mol%, 40 mol% to 65 mol% 45 mol% to 65 mol%, 50 mol% to 65 mol%, 55 mol% to 65 mol%, 60 mol% to 65 mol%, 40 mol% to 60 mol%, 45 mol% to 60 mol%, 50 mol% to 60 mol%, 55 mol% to 60 mol%, 40 mol% to 55 mol%, 45 mol% to 55 mol%, 50 mol% to 55 mol%, 40 mol% to 50 mol%, 45 mol% to 50 mol%, or 40 mol% to 45 mol% of carboxylic acid monomers are neutralized by zinc cations.

[0026] The composition further comprises a triazine-based UV absorber. In one embodiment, the triazine UV absorber may comprise 1,3,5-triazine-2,4,6-triphenyl, having at least one phenyl group containing a hydroxyl substituent at the ortho position and one or more substituents selected from hydroxyl, alkyl, or alkoxy at one or more positions on the phenyl group. In some examples, the composition comprises 0.01 wt% to 2.00 wt% of a UV stabilizer. In some examples, the composition comprises 0.01 wt% to 2.00 wt%, 0.05 wt% to 2.00 wt%, 0.10 wt% to 2.00 wt%, 0.10 wt% to 1.50 wt%, or 0.10 wt% to 1.00 wt% of a UV stabilizer.

[0027] The composition further comprises a hindered amine light stabilizer. Various hindered amine light stabilizers are considered suitable. In some embodiments, these hindered amine light stabilizers may comprise a heterocyclic amine moiety, such as piperidine. In some examples, the composition comprises 0.01 wt% to 2.00 wt% of a hindered amine light stabilizer. In some examples, the composition comprises 0.01 wt% to 2.00 wt%, 0.05 wt% to 2.00 wt%, 0.10 wt% to 2.00 wt%, 0.50 wt% to 2.00 wt%, or 0.50 wt% to 1.50 wt% of a hindered amine light stabilizer. Examples of suitable hindered amine light stabilizer compositions include CYASORB UV-3346 (C3346), a commercially available hindered amine light stabilizer from Solvay USA Inc, Cincinnati, OH.

[0028] The composition has a melt index (I2) of 0.1 g / 10 min to 30 g / 10 min as measured according to ASTM D1238 Procedure A (190°C, 2.16 kg). Unless otherwise specified, the melt index is measured in grams per 10 min (g / 10 min). In some examples, the melt flow of the ionomer is 0.1 g / 10 min to 30 g / 10 min, 0.2 g / 10 min to 15 g / 10 min, or 0.3 g / 10 min to 5 g / 10 min.

[0029] If the composition has a melt index (I2) below 0.1 g / 10 min, the ionomer may not have sufficient melt flow for processability. Conversely, if the melt flow of the ionomer is above 30.0 g / 10 min, it may be very difficult to shape and mold the ionomer, and physical properties such as tensile strength, elongation at break, and scratch resistance will decrease.

[0030] In some examples, the composition may further comprise polyethylene, nylon, ethylene vinyl alcohol (EVOH), or combinations thereof. In one or more examples, polyethylene, nylon, EVOH, or combinations thereof may include post-consumer recycled polyethylene, nylon, EVOH, or combinations thereof. In one or more examples, polyethylene, nylon, EVOH, or combinations thereof may include industrial recycled polyethylene, nylon, EVOH, or combinations thereof.

[0031] The composition may additionally include small amounts of additives, including plasticizers, stabilizers (including viscosity stabilizers and hydrolytic stabilizers), primary and secondary antioxidants, antistatic agents, dyes, pigments or other colorants, inorganic fillers, flame retardants, lubricants, reinforcing agents (glass fibers and glass sheets), synthetic (e.g., aramid) fibers or pulp, foaming or bubbling agents, processing aids, slip additives, anti-caking agents (such as silica or talc), release agents, tackifying resins, or combinations of two or more thereof. Inorganic fillers (such as calcium carbonate) may also be incorporated into the blend. These additives may be present in the blend in amounts ranging from 0.01 wt% to 40 wt%, 0.01 wt% to 25 wt%, 0.01 wt% to 15 wt%, 0.01 wt% to 10 wt%, or 0.01 wt% to 5 wt%. The incorporation of additives may be carried out by any known method, such as, for example, by dry blending, by extruding mixtures of various components, by conventional masterbatch techniques, etc.

[0032] Optionally, the composition may include additional ethylene-based polymers, such as HDPE. In one or more embodiments, the composition may include 20% to 60% by weight of HDPE, or 40% to 60% by weight of HDPE.

[0033] According to various examples, the composition can be used in a variety of articles. These may include foams, sheets, films, laminates, or other articles produced by sheet or profile extrusion processes.

[0034] In some embodiments, articles containing the composition exhibit an elongation retention of more than 85% after 115 hours of ultra-UV aging, as explained in detail below. In an example where the carboxylic acid monomer is neutralized with sodium cations, articles containing the composition exhibit a color index change of less than 5.0 after 270 hours of ultra-UV aging.

[0035] Test methods

[0036] Melt index (I2)

[0037] Melt index (I2) is measured according to ASTM D-1238, Procedure B (condition 190°C / 2.16 kg) (the entire contents of Procedure B are incorporated herein by reference) and reported in grams eluted per 10 minutes (g / 10 min).

[0038] Ultra UV aging

[0039] Elongation retention was measured after 115 hours of Super UV aging. A Super UV tester, commercially available from EYE Applied-Optix, was used. The Super UV tester is equipped with a proprietary metal halide UV lamp that generates high UV irradiance while controlling temperature and humidity. The test protocol consists of two alternating phases. In the first phase, the UV light is controlled at 1500 W / m². 2 A broadband UV irradiance of 300nm to 400nm was applied, with the temperature controlled at 63℃±2.5℃ and the relative humidity at 60%±10%. The first stage lasted 110 minutes. In the second stage, the UV light was controlled at 1500 W / m². 2 A broadband 300nm to 400nm UV irradiation was applied, with the temperature controlled at 63℃ ± 2.5℃, and the test samples were wetted with water spray. The second phase lasted 10 minutes. After the second phase ended, the first phase began again. This cycle continued during the test. The test samples were punched from the compression molding plate. For color index variation, 2” x 2” square samples were used. For elongation retention, five replicates were used using ASTM D1708 micro-tensile bars with a thickness of 3mm.

[0040] Elongation retention rate

[0041] The elongation retention of the test samples was determined by using the ultra-UV aging method described above for 115 hours. The ultimate tensile elongation of the test samples before and after ultra-UV aging was compared, and the elongation retention of the test samples was determined by calculating the percentage difference between the two values.

[0042] Color index change

[0043] The color index changes of the test samples were determined by using the ultra-UV aging method described above for 270 hours. The colors of the test samples before and after ultra-UV aging were compared. Color characterization was performed using a Datacolor SF 600 CTPlus color spectrometer with a D65 light source. The instrument output produced the CIE L*a*b* color scale. The total color shift ΔE is reported here to compare the degree of color change.

[0044] Scratch and abrasion test

[0045] Scratch and abrasion tests were performed on the Rockwood Systems and Equipment Five-Finger Scratch and Abrasion Tester. The tester has five metal fingers, each 250 mm long, mounted parallel to each other on a common pivot. Scratch pins with a diameter of 1 mm were installed on the lower edge of the metal fingers, 200 mm from the pivot. Four holes, spaced 15 mm apart, were placed on the upper edge at positions 135 mm, 150 mm, 165 mm, and 180 mm from the pivot. Weights with two pins on the longer, narrower edge of the plate were placed in the center of the upper surface of the metal fingers (three in total), centered on the plate's center of mass and spaced 15 mm apart. The weights were 140.8 g, 278.5 g, 554.9 g, 693.3 g, and 1124.3 g. The test sample was taped to a movable carriage located below the pins on the tester. The metal fingers were lowered onto the sample, and the contact point (i.e., the starting point) was marked with a permanent marker. The carriage with the sample is then dragged under the pin at a speed of approximately 4 inches per second. The metal fingers are then lifted off the sample and removed.

[0046] The extent of damage to the samples was quantified using laser scanning confocal microscopy (LSCM) to analyze the scratch depth on each sample surface. The instrument used was a Keyence VK-X200K LSM. To capture both the scratches and the flat planes surrounding each scratch, a 3x5 mosaic pattern was collected using a 20x objective lens and stitched onto a surface model of the scratches. The average depth profile of the scratches was analyzed using Keyence VK analyzer software. For each sample, forty individual line profiles were used to generate an average profile. The height of the deepest part of the scratch valley was measured and compared to the height of the flat planes surrounding the patch (plane to valley); measurements were also taken starting from the deepest part of the scratch valley and compared to the peaks of adjacent scratch extensions (peak to valley).

[0047] Example

[0048] The following embodiments are provided by way of illustration and are presented in a manner that would be recognized by those skilled in the art, and are not intended to limit the whole of this disclosure or the appended claims.

[0049] Non-ionomer resin

[0050] UNIVAL DMDA-6220 has a concentration of 0.953 g / cm³. 3 A high-density polyethylene resin with a density of 0.38 g / 10 min and a melt index (I2) of 0.38 g / 10 min, which is commercially available from Dow Inc., Midland, MI.

[0051] CYASORB UV-1164 (C1164) was used as the UV absorber, which is a commercially available triazine UV absorber from Solvay USA Inc, Cincinnati, OH.

[0052] CYASORB UV-5411 (C5411) was used as the UV absorber, which is a commercially available benzotriazole UV absorber from Solvay USA Inc, Cincinnati, OH.

[0053] CYASORB UV-3346 (C3346) was used as a light stabilizer, which is a commercially available hindered amine light stabilizer that is commercially available from Solvay USA Inc, Cincinnati, OH.

[0054] All ethylene / MAA copolymers are prepared by standard free radical copolymerization, using high pressure and operated continuously. The ionomer is fed into the reaction mixture in a ratio related to the monomer reactivity and desired incorporation amount. In this manner, a uniform, nearly random distribution of monomer units along the chain is achieved. Polymerization in this manner is well known and described in U.S. Patent No. 4,351,931 (Armitage), which is incorporated herein by reference. Other polymerization techniques are described in U.S. Patent Nos. 5,028,674 (Hatch et al.) and 5,057,593 (Statz), both of which are incorporated herein by reference. The following procedure is used to prepare the ionomers of these acid copolymers.

[0055] The ionomers of this invention can be prepared by standard neutralization techniques, as disclosed in U.S. Patent No. 3,264,272 (Rees), which is incorporated herein by reference. Other neutralization techniques are described in U.S. Patent Nos. 3,404,134 (Rees) and 3,649,578 (Bush et al.), which are incorporated herein by reference. Various neutralizing ions and neutralization percentages, as well as some additional properties, are shown in Table 1.

[0056] Table 1: Melt Index (I2), Ion Type, Initial Acidity, and Neutralization Percentage

[0057]

[0058] Test samples containing the components listed in Table 2 were prepared as follows. First, resin granules (e.g., ionomers) and UV additives were dry-blended in a plastic liner. Then, the blended granules and additives were compounded in a Coperion ZSK 26mm twin-screw extruder with a length of 44mm and a diameter of 26mm. The melt temperature was 220°C to 235°C, the screw speed was 300 rpm, and the yield was 6.8 kg / hr to 9.1 kg / hr.

[0059] The compounded material is then extruded through a 3mm two-hole die and dropped into a 6-foot-long cooling water bath. The wire is passed through the water bath in a single pass. Next, the wire is granulated using a Conair 304 wire pelletizer. The finished pellets are dried overnight in a fume hood under nitrogen.

[0060] Then, according to ASTM D4703, in accordance with Appendix A1, the finished pellets are formed into plates with dimensions of 127 mm in length, 127 mm in width, and 3 mm in thickness by compression molding at 180°C to 190°C.

[0061] Table 2: Composition of the test samples

[0062]

[0063] The compression molded plate samples in Table 2 underwent scratch and abrasion tests, and the results are provided in Table 3. The scratched surfaces were created by metal fingers carrying a weight of 1124.3 g. (See the Scratching and Abrasion Testing section)

[0064] Table 3: Results of Scratch and Abrasion Tests

[0065]

[0066] The elongation retention and color index changes of the compression molded plate samples in Table 2 are shown in Table 4.

[0067] Table 4: Changes in Elongation Retention and Color Index

[0068]

[0069] As shown in Table 4 above, all samples including ionomers (i.e., sample IDs CE5-CE15) failed to retain more than 85% elongation after 115 hours of ultra-UV aging. These ionomers comprised vinyl acetate copolymers containing more than 8% by weight of carboxylic acid monomers. This highlights the importance of having 6% by weight or less of carboxylic acid monomers in the compositions described herein. Furthermore, regardless of whether triazine-based or benzotriazole-based UV absorbers were used, the samples including ionomers failed to retain more than 85% elongation after 115 hours of ultra-UV aging. These ionomers comprised vinyl acetate copolymers containing more than 8% by weight of carboxylic acid monomers, further emphasizing the criticality of having 6% by weight or less of carboxylic acid monomers in the compositions described herein.

[0070] Furthermore, when using benzotriazole UV absorbers, samples with only 4% by weight of carboxylic acid monomers failed to maintain an elongation retention of more than 85% after 115 hours of ultra-UV aging, as demonstrated by samples ID CE1-CE4, thus highlighting the importance of using triazine UV absorbers.

[0071] Furthermore, even when using triazine UV absorbers, the presence of polyethylene additives prevented sample ID CE15, with more than 8% by weight of carboxylic acid monomers, from achieving an elongation retention of over 85% after 115 hours of ultra-UV aging. However, the elongation retention of samples with 6% by weight or less of carboxylic acid monomers was largely unaffected by the presence of polyethylene additives, as can be seen by comparing samples ID IE1-IE3 with samples ID IE4-IE6.

[0072] Interestingly, comparing sample ID CE16 with samples ID IE3 and IE6 showed that for the sample with 75 mol% of carboxylic acid monomer neutralized by zinc cations, an elongation retention of over 85% was achieved after 115 hours of ultra-UV aging. However, when more than 75 mol% of carboxylic acid monomer was neutralized by zinc cations, an elongation retention of over 85% was not achieved after 115 hours of ultra-UV aging.

[0073] Additionally, note that samples neutralized with sodium cations exhibited a color index change of less than 5.0 after 270 hours of ultra-UV aging, as shown in samples ID IE1, IE3, IE4, and IE6. However, samples ID IE2 and IE4 failed to show a color index change of less than 5.0 after 270 hours of ultra-UV aging, but still maintained an elongation retention rate of over 85% after 115 hours of ultra-UV aging.

[0074] Unless otherwise specified, all technical and scientific terms used herein shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In case of any conflict, this specification (including definitions) shall prevail.

[0075] While methods and materials similar to or equivalent to those described herein can be used to implement or test various embodiments, suitable methods and materials are described herein.

[0076] Unless otherwise stated, all percentages, parts, ratios, etc., are by weight. When a quantity, concentration, or other value or parameter is given as a range, a preferred range, or a series of lower and upper preferred values, it should be understood as specifically disclosing all ranges formed by any pair of any lower or preferred ranges and any upper or preferred values, regardless of whether the range is disclosed individually. When numerical ranges are listed herein, unless otherwise stated, the range is intended to include its endpoint values ​​as well as all integers and fractions within that range. When ranges are defined, it is not intended to limit the scope of this disclosure to the specific values ​​listed.

[0077] As used herein, the terms “comprising,” “including,” “containing,” “characterized by,” “having,” or any other variation thereof are intended to cover non-exclusive inclusion. For example, a process, article, or apparatus that includes a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such a process, method, article, or apparatus. Furthermore, unless expressly stated to the contrary, “or” means inclusive or, not exclusive or.

[0078] The transitional phrase "consistently of..." limits the scope of the claims to the specified materials or steps and does not substantially affect the essential and novel features of this disclosure. Unless otherwise stated, where the applicant defines an embodiment or part thereof using open-ended terms such as "comprising," this description should be interpreted as also using the term "consistently of..." to describe such embodiments.

[0079] The use of the word "a" is to describe the elements and components of various embodiments. This is merely for convenience and to give a general meaning to the various embodiments. Unless explicitly stated otherwise, this description should be understood to include one or at least one, and the singular includes the plural.

Claims

1. A composition comprising: Ionomers, said ionomers comprising vinyl acid copolymers, said vinyl acid copolymers comprising polymerization products of the following: 60% to 99% wt% ethylene; and 1% to 6% by weight of carboxylic acid monomers; The ethylene copolymer is at least partially neutralized by a metal cation comprising zinc or sodium, provided that when the metal cation comprises zinc, at most 75 mol% of the carboxylic acid monomer is neutralized; Triazine-based UV absorbers; and Hindered amine light stabilizers.

2. The composition according to claim 1, wherein the ionomer has a melt index (I2) of 0.1 g / 10 min to 30 g / 10 min.

3. The composition according to any of the preceding claims, wherein 40 mol% to 100 mol% of the carboxylic acid monomer is neutralized by sodium cations.

4. The composition according to any of the preceding claims, wherein 40 mol% to 75 mol% of the carboxylic acid monomer is neutralized by zinc cations.

5. The composition according to any of the preceding claims, wherein the triazine-based UV absorber comprises 1,3,5-triazine, 2,4,6-triphenyl, having at least one phenyl group having a hydroxyl substituent at the ortho position and one or more substituents selected from hydroxyl, alkyl, or alkoxy at one or more positions on the phenyl group.

6. The composition according to any of the preceding claims, wherein the composition comprises 1% to 99% by weight of an ionomer.

7. The composition according to any of the preceding claims, wherein the composition comprises 0.01% to 2.00% by weight of a UV stabilizer.

8. The composition according to any of the preceding claims, wherein the composition comprises 0.01% to 2.00% by weight of a hindered amine light stabilizer.

9. The composition according to any of the preceding claims, wherein the composition further comprises virgin polyethylene, recycled polyethylene, nylon, EVOH, or a combination thereof.

10. The composition according to any of the preceding claims, wherein the composition further comprises HDPE.

11. The composition of claim 10, wherein the composition comprises 20% to 60% by weight of HDPE.

12. An article comprising the composition according to any of the preceding claims.

13. The article of claim 12, wherein the article is a molded article, a sheet, a profile extrusion, or a foam.

14. The article of claim 12 or any one of claim 13, wherein the article of claim 12 exhibits an elongation retention of more than 85% after 115 hours of ultra-UV aging.

15. The article according to any one of claims 12 to 14, wherein the carboxylic acid monomer is neutralized by sodium cations, and wherein the article exhibits a color index change of less than 5.0 after 270 hours of ultra-UV aging.

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