Compositions, multilayer films and articles formed from such compositions

Abstract

Various embodiments of the present invention relate to compositions, multilayer films, and articles. In one aspect, a composition comprises: (a) an ionomer, which is an acid copolymer comprising ethylene and at least one of acrylic acid and methacrylic acid, wherein a portion of the acid groups in the acid copolymer is neutralized by metal ions and is a carboxylate, and wherein the acid copolymer comprises 5% to 30% by weight of acrylic acid and methacrylic acid prior to the neutralization of the acid groups by the metal ions; (b) an ethylene / unsaturated ester copolymer comprising ethylene vinyl acetate, ethylene acrylate, or a combination thereof; and (c) a propylene-based polymer comprising a copolymer of propylene and a comonomer including ethylene, butene, hexene, or octene, wherein the propylene-based polymer has a molecular weight distribution (MWD) of less than 3.0 and a viscosity ratio of greater than 7.0 (at 0.1s). ‑1 Viscosity at 100s ‑1 (viscosity below).

Description

Technical Field

[0001] This disclosure relates to compositions, multilayer films comprising such compositions, and articles comprising such compositions or such multilayer films. Background Technology

[0002] Multilayer flexible films are used in a variety of applications, including, for example, food packaging and specialty packaging. At least one outer layer of a multilayer film is typically a sealant layer. When heated, the sealant layer can adhere the multilayer film to other films, other surfaces (e.g., rigid packaging surfaces), or itself. In packaging applications, the strong seal from the sealant layer keeps the product fresh and protected. However, for some types of packaging, it is desirable that the seal be peelable so that consumers do not experience difficulty opening the packaging. It is also desirable that such a sealant layer facilitates clean peeling, avoiding or minimizing the formation of polymer chains or strips during peeling when the consumer peels open the packaging. In some film designs, a subsurface layer (the layer adjacent to the outer layer) can be designed to facilitate peeling.

[0003] There is still a need for new compositions that can be used as sealants, providing peelable seal strength, clean peeling, and / or mitigating gauge band formation during manufacturing. Summary of the Invention

[0004] This invention provides compositions that can be used in multilayer films and articles to facilitate the opening of articles such as packaging by peeling. In some embodiments, multilayer films using the compositions of this invention in the sealant layer or subsurface layer advantageously have peelable sealing strength and provide clean peeling (avoiding or minimizing the formation of polymer chains or strips during peeling).

[0005] In one aspect, the present invention provides a composition comprising: (a) an ionomer, which is an acid copolymer comprising ethylene and at least one of acrylic acid and methacrylic acid, wherein a portion of the acid groups in the acid copolymer are neutralized by metal ions and are carboxylates, and wherein the acid copolymer comprises 5% to 30% by weight of acrylic acid and methacrylic acid prior to the neutralization of the acid groups by metal ions; (b) an ethylene / unsaturated ester copolymer comprising ethylene vinyl acetate, ethylene acrylate, or combinations thereof; and (c) a propylene-based polymer comprising a copolymer of propylene and a comonomer including ethylene, butene, hexene, or octene, wherein the propylene-based polymer has a molecular weight distribution (MWD) of less than 3.0 and a viscosity ratio of greater than 7.0 (at 0.1s). -1 Viscosity at 100s -1 (viscosity below).

[0006] As discussed below, the present invention also provides multilayer films, wherein at least one layer comprises any of the inventive compositions disclosed herein. The present invention also provides articles formed from any such multilayer film (i.e., wherein at least one layer of the multilayer film comprises any of the inventive compositions disclosed herein).

[0007] These and other implementation schemes are discussed in more detail in the specific implementation scheme. Detailed Implementation

[0008] Unless stated to the contrary, implied by the context or customary in the art, all parts and percentages are by weight, all temperatures are in °C, and all test methods are current methods as of the date of this disclosure.

[0009] As used herein, the term "composition" refers to a mixture of materials comprising the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0010] "Polymer" means a polymeric compound prepared by polymerizing monomers (whether of the same or different types). Therefore, the general term polymer encompasses the terms homopolymer (used to refer to polymers prepared from only one type of monomer, where it should be understood that trace impurities may be incorporated into the polymer structure) and interpolymer, as defined below. Trace impurities (e.g., catalyst residues) may be incorporated into and / or within the polymer. A polymer can be a single polymer, a polymer blend, or a mixture of polymers comprising a mixture of polymers formed in situ during polymerization.

[0011] 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 (used to refer to polymers prepared from two different types of monomers) and polymers prepared from more than two different types of monomers.

[0012] As used herein, the term "olefin polymer" or "polyolefin" refers to a polymer that comprises a majority amount of olefin monomers, such as ethylene or propylene (by weight of the polymer), in polymeric form, and optionally may include one or more comonomers.

[0013] As used herein, the term "ethylene / α-olefin interpolymer" refers to an interpolymer comprising, in polymeric form, a majority (>50 mol%) unit derived from ethylene monomers and the remaining units derived from one or more α-olefins. Typical α-olefins used to form ethylene / α-olefin interpolymers are C3-C64 ... 10 Olefins.

[0014] As used herein, the term "ethylene / α-olefin copolymer" refers to a copolymer comprising a majority amount (>50 mol%) of ethylene monomer and α-olefin as the only two monomer types.

[0015] As used herein, the term "α-olefin" refers to an olefin having a double bond at the primary or α (alpha) position.

[0016] "Polyethylene" or "ethylene-based polymer" should mean a polymer comprising a majority (>50 mol%) unit derived from ethylene monomers. This includes polyethylene homopolymers, ethylene / α-olefin interpolymers, and ethylene / α-olefin copolymers. Common forms of polyethylene known in the art include low-density polyethylene (LDPE); linear low-density polyethylene (LLDPE); ultra-low-density polyethylene (ULDPE); very low-density polyethylene (VLDPE); medium-density polyethylene (MDPE); high-density polyethylene (HDPE); reinforced polyethylene; polyethylene elastomers; and polyethylene plastomers. These polyethylene materials are generally known in the art; however, the following description may help to understand the differences between some of these different polyethylene resins.

[0017] The term "LDPE" can also be referred to as "high-pressure ethylene polymer" or "highly branched polyethylene," and it is defined as meaning that the polymer is partially or wholly homopolymerized or copolymerized in an autoclave or tubular reactor at pressures above 14,500 psi (100 MPa) using a free radical initiator (such as peroxide) (see, for example, US 4,599,392, which is hereby incorporated herein by reference). The density of LDPE resin is typically around 0.916 g / cm³. 3 Up to 0.935 g / cm 3 Within the range.

[0018] The term "LLDPE" encompasses two types of resins prepared using conventional Ziegler-Natta catalyst systems and chromium-based catalyst systems, as well as single-center catalysts (including, but not limited to, bismetallocene catalysts (sometimes referred to as "m-LLDPE"), geometry-defined catalysts (CGC), and molecular catalysts). The resins include linear, substantially linear, or heterogeneous polyethylene copolymers or homopolymers. Compared to LDPE, LLDPE comprises fewer long-chain branched components and consists of substantially linear ethylene polymers, further defined in U.S. Patents 5,272,236, 5,278,272, 5,582,923, and 5,733,155; homogeneous branched linear ethylene polymer compositions, such as those in U.S. Patent No. 3,645,992; multiphase branched ethylene polymers, such as those prepared according to the process disclosed in U.S. Patent No. 4,076,698; and / or blends thereof (such as those disclosed in U.S. 3,914,342 or U.S. 5,854,045). LLDPE can be prepared by gas-phase, solution-phase, or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0019] The term "MDPE" refers to a material with a density of 0.926 g / cm³. 3 Up to 0.940 g / cm 3 Polyethylene with a density of 2.5. "MDPE" is typically prepared using chromium or Ziegler-Natta catalysts or using single-center catalysts (including, but not limited to, bis-metallocene catalysts, catalysts with defined geometries, and molecular catalysts), and its molecular weight distribution ("MWD") is typically greater than 2.5.

[0020] The term "HDPE" refers to a material with a density greater than approximately 0.940 g / cm³. 3 And at most about 0.970 g / cm³ 3 Polyethylene, which is generally prepared using Ziegler-Natta catalysts, chromium catalysts or single-center catalysts (including but not limited to bis-metallocene catalysts and catalysts with restricted geometry).

[0021] The term "ULDPE" refers to a material with a density of 0.880 g / cm³. 3 Up to 0.912 g / cm 3 Polyethylene, which is generally prepared using Ziegler-Natta catalysts, chromium catalysts or single-center catalysts (including but not limited to bis-metallocene catalysts and catalysts with restricted geometry).

[0022] "Polyethylene plasmon / elastomer" is a compound comprising units derived from ethylene and units derived from at least one C3-C 10A substantially linear or linear ethylene / α-olefin copolymer containing homogeneous short-chain branched units of α-olefin comonomers, or at least one C4-C8 α-olefin comonomer, or at least one C6-C8 α-olefin comonomer. The polyethylene plastomer / elastomer has a density of 0.870 g / cm³. 3 or 0.880 g / cm 3 or 0.890 g / cm 3 Up to 0.900 g / cm 3 or 0.902 g / cm 3 or 0.904 g / cm 3 or 0.909 g / cm 3 or 0.910 g / cm 3 Or 0.917 g / cm 3 The density. Non-limiting embodiments of polyethylene plastomers / elastomers include AFFINITY. TM Plastomers and elastomers (available from The Dow Chemical Company), EXACT plasticizers (available from ExxonMobil Chemical), Tafmer (available from Mitsui), Nexlene TM (Available from SK Chemicals Co.) and Lucene (Available from LG Chem Ltd.)

[0023] As used herein, the term "propylene-based polymer" refers to a polymer that, by weight, comprises a majority amount of propylene monomers in polymeric form and may optionally include one or more comonomers.

[0024] The terms “blend” and “polymer blend” mean a composition of two or more polymers. Such blends may or may not be miscible. Such blends may or may not be phase-separated. As determined by transmission electron spectroscopy, light scattering, X-ray scattering, and any other methods known in the art, such blends may or may not contain one or more domain configurations. Blends are not laminates, but one or more layers of a laminate may contain blends. Such blends can be prepared as dry blends, in-situ formed (e.g., in a reactor), melt blends, or using other techniques known to those skilled in the art.

[0025] The term "adhesive contact" and similar terms refer to a situation where one surface of one layer touches and adheres to another surface of another layer, such that one layer cannot be removed from the other without damaging the interlayer surfaces (i.e., contact surfaces) of the two layers.

[0026] The terms “comprising,” “including,” “having,” and their derivatives are not intended to exclude the presence of any additional components, steps, or procedures, whether or not such components, steps, or procedures are specifically disclosed. For the avoidance of any doubt, unless stated to the contrary, all compositions claimed using the term “comprising” may include any additional additives, adjuvants, or compounds, whether polymerized or otherwise. In contrast, the term “substantially constitutes” excludes any other components, steps, or procedures from any subsequently listed scope, except those that are not essential for operability. The term “consisting of” excludes any ingredients, steps, or procedures not specifically described or listed.

[0027] The present invention provides compositions that, in some embodiments, can be used in multilayer films and articles to facilitate the opening of articles such as packaging by peeling off with desired seal strength and by providing a clean seal.

[0028] In one embodiment, the composition according to the invention comprises: (a) an ionomer, which is an acid copolymer comprising ethylene and at least one of acrylic acid and methacrylic acid, wherein a portion of the acid groups in the acid copolymer is neutralized by metal ions and is a carboxylate, and wherein the acid copolymer comprises 5% to 30% by weight of acrylic acid and methacrylic acid prior to the neutralization of the acid groups by metal ions; (b) an ethylene / unsaturated ester copolymer comprising ethylene vinyl acetate, ethylene acrylate, or a combination thereof; and (c) a propylene-based polymer comprising a copolymer of propylene and a comonomer comprising ethylene, butene, hexene, or octene, wherein the propylene-based polymer has a molecular weight distribution (MWD) of less than 3.0 and a viscosity ratio of greater than 7.0 (at 0.1s). -1 Viscosity at 100s -1 (viscosity below). In some embodiments, the acid copolymer contains 5% to 20% by weight of acrylic acid and methacrylic acid before the acid groups are neutralized by metal ions. In some embodiments, the acid copolymer contains 5% to 15% by weight of acrylic acid and methacrylic acid before the acid groups are neutralized by metal ions.

[0029] Regarding propylene-based polymers, in some embodiments, the propylene-based polymers have a melting point greater than 125°C (T0). mIn some embodiments, the propylene-based polymer is a copolymer of propylene and ethylene, and wherein the ethylene content in the propylene-based polymer is less than 5% by weight. In some embodiments, the propylene-based polymer is a copolymer of propylene and ethylene, and wherein the ethylene content in the propylene-based polymer is less than 1% by weight. In some embodiments, the propylene-based polymer has a melt flow rate of 0.5 g / 10 min to 30 g / 10 min.

[0030] Regarding the ionomer, in some embodiments, the metal ions used to neutralize the acrylic acid or methacrylic acid of the acid copolymer to generate the ionomer include zinc, sodium, lithium, magnesium, or combinations thereof. In some embodiments, based on the total number of acid groups in the acid copolymer, 10% to 60% of the total acrylic acid and methacrylic acid groups are neutralized by metal ions. In some embodiments, 10% to 50% of the total acrylic acid and methacrylic acid groups are neutralized by metals in the ionomer. In some embodiments, 10% to 40% of the total acrylic acid and methacrylic acid groups are neutralized by metals in the ionomer.

[0031] Regarding ethylene / unsaturated ester copolymers, in some embodiments, the ethylene / unsaturated ester copolymer is ethylene vinyl acetate, and the ethylene vinyl acetate comprises 8% to 30% vinyl acetate. In some embodiments, the ethylene / unsaturated ester copolymer is ethylene vinyl acetate, and the ethylene vinyl acetate comprises 12% to 30% vinyl acetate, or in other embodiments, it comprises 20% to 30% vinyl acetate. In some embodiments, the ethylene / unsaturated ester copolymer is ethylene acrylate, and the ethylene acrylate comprises 8% to 25% acrylate. In some embodiments, the ethylene / unsaturated ester copolymer is ethylene acrylate, and the ethylene acrylate comprises 12% to 25% acrylate, or in other embodiments, it comprises 17% to 25% acrylate.

[0032] In some embodiments, the composition comprises 40% to 70% by weight of an ionomer, based on the total weight of the composition. In some embodiments, the composition comprises 50% to 65% by weight of an ionomer, based on the total weight of the composition. In some embodiments, the composition comprises 10% to 40% by weight of an ethylene / unsaturated ester copolymer, based on the total weight of the composition. In some embodiments, the composition comprises 15% to 30% by weight of an ethylene / unsaturated ester copolymer, based on the total weight of the composition. In some embodiments, the composition comprises 5% to 30% by weight of a propylene-based polymer, based on the total weight of the composition. In some embodiments, the composition comprises 5% to 25% by weight of a propylene-based polymer, based on the total weight of the composition.

[0033] In some embodiments, the weight percentage of the ionomer in the composition to the weight percentage of the propylene-based polymer in the composition is from 1.3 to 15.0. In some embodiments, the weight percentage of the ionomer in the composition to the weight percentage of the propylene-based polymer in the composition is from 2.0 to 14.0. In some embodiments, the weight percentage of the ionomer in the composition to the weight percentage of the propylene-based polymer in the composition is from 2.8 to 13.0.

[0034] The present invention also provides multilayer films, wherein at least one layer comprises any of the inventive compositions disclosed herein. In some embodiments, the composition is the outer layer of the multilayer film. In some embodiments, the composition is located in a layer adjacent to the outer layer (e.g., in a subsurface layer).

[0035] The present invention also provides articles formed from any such multilayer film (i.e., wherein at least one layer of the multilayer film comprises any of the inventive compositions disclosed herein).

[0036] Isopolymer

[0037] Compositions according to various embodiments of the invention comprise an ionomer, which is an acid copolymer comprising ethylene and at least one of acrylic acid and methacrylic acid, wherein a portion of the acid groups in the acid copolymer is neutralized by metal ions and is a carboxylate. For ease of reference, acid copolymers comprising ethylene and at least one of acrylic acid and methacrylic acid are also referred to herein as "ethylene / (meth)acrylic acid copolymers," and it should be understood that some such copolymers may comprise both acrylic acid monomers and methacrylic acid monomers.

[0038] Ionomers are ionically crosslinked thermoplastics typically obtained by neutralizing copolymers containing side acid groups (e.g., carboxylic acid groups) with ionizable metal compounds (e.g., compounds of monovalent, divalent, and / or trivalent metals from groups I, II, IV-A, and VIIIB of the periodic table).

[0039] In various embodiments of the invention, the ionomer is an acid copolymer comprising ethylene and at least one of acrylic acid and methacrylic acid, wherein a portion of the acid groups in the acid copolymer is neutralized by metal ions and is a carboxylate. In some embodiments, the acid copolymer comprises 5% to 30% by weight of acrylic acid and methacrylic acid before the acid groups are neutralized by metal ions. In other words, if the acid copolymer comprises ethylene and acrylic acid only, the amount of acrylic acid in the acid copolymer is 5% to 30% by weight before the acid groups are neutralized by metal ions; if the acid copolymer comprises ethylene and methacrylic acid only, the amount of methacrylic acid in the acid copolymer is 5% to 30% by weight before the acid groups are neutralized by metal ions; if the acid copolymer comprises ethylene and both acrylic acid and methacrylic acid, the total amount of acrylic acid and methacrylic acid in the acid copolymer is 5% to 30% by weight before the acid groups are neutralized by metal ions.

[0040] In some embodiments, the acid copolymer contains 5% to 20% by weight of acrylic acid and methacrylic acid before the acid groups are neutralized by metal ions. In other words, if the acid copolymer contains ethylene and acrylic acid only, the amount of acrylic acid in the acid copolymer is 5% to 20% by weight before the acid groups are neutralized by metal ions; if the acid copolymer contains ethylene and methacrylic acid only, the amount of methacrylic acid in the acid copolymer is 5% to 20% by weight before the acid groups are neutralized by metal ions; if the acid copolymer contains ethylene and both acrylic acid and methacrylic acid, the total amount of acrylic acid and methacrylic acid in the acid copolymer is 5% to 20% by weight before the acid groups are neutralized by metal ions.

[0041] In some embodiments, the acid copolymer contains 5% to 15% by weight of acrylic acid and methacrylic acid before the acid groups are neutralized by metal ions. In other words, if the acid copolymer contains ethylene and acrylic acid only, the amount of acrylic acid in the acid copolymer is 5% to 15% by weight before the acid groups are neutralized by metal ions; if the acid copolymer contains ethylene and methacrylic acid only, the amount of methacrylic acid in the acid copolymer is 5% to 15% by weight before the acid groups are neutralized by metal ions; if the acid copolymer contains ethylene as well as both acrylic acid and methacrylic acid, the total amount of acrylic acid and methacrylic acid in the acid copolymer is 5% to 15% by weight before the acid groups are neutralized by metal ions.

[0042] The ethylene / (meth)acrylic acid copolymers used to form ionomers can be characterized as random copolymers. Such ethylene / (meth)acrylic acid copolymers can be prepared under high pressure using techniques known to those skilled in the art, by the action of a free radical polymerization initiator on a mixture of ethylene and acrylic acid and / or methacrylic acid monomers. The ethylene / (meth)acrylic acid copolymers used in the compositions of the present invention are more precisely referred to as interpolymers because they are formed by the polymerization of a mixture of comonomers, as opposed to copolymers prepared by “grafting” or “block polymerization” methods.

[0043] Based on the total number of acid groups in the acid copolymer, the ionomer of the composition used in the present invention is obtained by reacting the aforementioned copolymer with a sufficient amount of metal ions to neutralize at least a portion, preferably at least 10%, of the present acid groups. In some embodiments, 10% to 60% of the total acrylic and methacrylic groups based on the total number of acid groups in the acid copolymer are neutralized by metal ions. In some embodiments, 10% to 50% of the total acrylic and methacrylic groups based on the total number of acid groups in the acid copolymer are neutralized by metal ions. In some embodiments, 10% to 40% of the total acrylic and methacrylic groups based on the total number of acid groups in the acid copolymer are neutralized by metal ions. Suitable metal ions include zinc (Zn). +2 ), sodium (Na + Lithium (Li) + ), magnesium (Mg) +2 (or a combination thereof). In some implementations, one or more ionomers may be used.

[0044] In some embodiments, the ionomer may also be characterized as having a melt index (I2) ranging from 0.5 g / 10 min to 60 g / 10 min. This document includes and discloses all individual values ​​and sub-ranges between 0.5 g / 10 min and 60 g / 10 min. For example, the ionomer may have a melt index ranging from a lower limit of 0.5 g / 10 min, 1 g / 10 min, 5 g / 10 min, 10 g / 10 min, 15 g / 10 min, or 20 g / 10 min to an upper limit of 10 g / 10 min, 15 g / 10 min, 20 g / 10 min, 25 g / 10 min, 30 g / 10 min, 35 g / 10 min, 40 g / 10 min, 45 g / 10 min, 50 g / 10 min, or 55 g / 10 min. In some embodiments, the ionomer has a melt index (I2) of 0.5 g / 10 min to 40 g / 10 min, and in some embodiments, a melt index (I2) of 0.5 g / 10 min to 30 g / 10 min. In some embodiments, the ionomer has a melt index (I2) of 0.5 g / 10 min to 15 g / 10 min.

[0045] In some embodiments, the composition comprises 40% to 70% ionomer based on the weight of the composition. In some embodiments, the composition comprises at least 50% ionomer based on the weight of the composition. In some embodiments, the composition comprises up to 65% ionomer based on the weight of the composition. All individual values ​​and sub-ranges of 40% to 70% ionomer are included and disclosed herein; for example, the amount of ionomer in the composition can be from the lower limit of 45% ionomer, 50% ionomer, 50% ionomer, 55% ionomer, or 60% ionomer to the upper limit of 60% ionomer, 65% ionomer, or 70% ionomer based on the weight of the composition. For example, the amount of ionomer in the composition can be from 50% ionomer to 65% ionomer based on the weight of the composition.

[0046] Examples of commercially available ionomers of ethylene / (meth)acrylic acid copolymers that can be used in various embodiments of the present invention include SURLYN, which is commercially available from The Dow Chemical Company. TM Ionic polymers, such as SURLYN TM 1650SB, SURLYN TM 1706, SURLYN TM 1702, SURLYN TM 1605 and SURLYN TM 1707.

[0047] Ionomers of ethylene / (meth)acrylic acid copolymers may have a combination of two or more properties as described in the above embodiments.

[0048] Ethylene / unsaturated ester copolymer

[0049] In addition to ionomers of ethylene / (meth)acrylic acid copolymers, the compositions of the present invention also comprise ethylene / unsaturated ester copolymers. An ethylene / unsaturated ester copolymer is a copolymer or interpolymer comprising ethylene and at least one monomer, wherein the at least one monomer is an ester and has an unsaturation degree, preferably at least one double bond copolymerizable with ethylene. The ester is preferably a carboxylic acid ester and is referred to herein as an unsaturated ester. The acid or alcohol moiety of the ester is optionally unsaturated, or both the acid or alcohol moiety of the ester are unsaturated. Examples of unsaturated esters wherein the acid moiety is unsaturated include acrylates and methacrylates. In some embodiments, these esters are alkyl esters, such as methyl acrylate, ethyl acrylate, and butyl acrylate. Examples of unsaturated esters wherein the alcohol moiety is unsaturated include vinyl esters, such as vinyl acetate, as well as vinyl propionate, vinyl butyrate, and vinyl hexanoate.

[0050] In some embodiments, the ethylene / unsaturated ester copolymer may also be characterized as having a melt index (I2) ranging from 0.5 g / 10 min to 60 g / 10 min. This document includes and discloses all individual values ​​and sub-ranges between 0.5 g / 10 min and 60 g / 10 min. For example, the ethylene / unsaturated ester copolymer may have a melt index ranging from a lower limit of 0.5 g / 10 min, 1 g / 10 min, 5 g / 10 min, 10 g / 10 min, 15 g / 10 min, or 20 g / 10 min to an upper limit of 10 g / 10 min, 15 g / 10 min, 20 g / 10 min, 25 g / 10 min, 30 g / 10 min, 35 g / 10 min, 40 g / 10 min, 45 g / 10 min, 50 g / 10 min, or 55 g / 10 min. In some embodiments, the ethylene / unsaturated ester copolymer has a melt index (I2) of 0.5 g / 10 min to 40 g / 10 min, and in some embodiments, a melt index (I2) of 0.5 g / 10 min to 30 g / 10 min. In some embodiments, the ethylene / unsaturated ester copolymer has a melt index (I2) of 0.5 g / 10 min to 15 g / 10 min.

[0051] Ethylene / unsaturated ester copolymers in which the unsaturated ester is a vinyl ester are well known and commercially available from a variety of sources. In one embodiment, the ethylene / unsaturated ester copolymer is ethylene vinyl acetate. Non-limiting examples of ethylene vinyl acetate that can be used in some embodiments of the present invention include ELVAX, which is commercially available from Dow Chemical Company. TM Ethylene vinyl acetate copolymers, such as ELVALX TM 650Q.

[0052] In some embodiments where the ethylene unsaturated ester copolymer is ethylene vinyl acetate, the composition comprises 8% to 40% ethylene vinyl acetate based on the total weight of the composition. In some embodiments, the composition comprises 8% to 30% ethylene vinyl acetate based on the total weight of the composition. In some embodiments, the composition comprises 12% to 30% ethylene vinyl acetate based on the total weight of the composition. In some embodiments, the composition comprises 20% to 30% ethylene vinyl acetate based on the total weight of the composition.

[0053] Unsaturated esters are ethylene / unsaturated ester copolymers of acrylates (e.g., methyl acrylate, ethyl acrylate, butyl acrylate, etc.), which are well known and commercially available from a variety of sources. In one embodiment, the ethylene / unsaturated ester copolymer is ethylene methyl acrylate. Non-limiting examples of ethylene acrylates that can be used in some embodiments of the invention include ELVALOY, which is commercially available from Dow Chemical Company. TMAC ethylene acrylate copolymers, such as ELVALOY TM AC1820 and ELVALOY TM AC 1224.

[0054] In some embodiments where the ethylene / unsaturated ester copolymer is ethylene acrylate, the composition comprises 8% to 40% ethylene acrylate based on the total weight of the composition. In some embodiments, the composition comprises 8% to 25% ethylene acrylate based on the total weight of the composition. In some embodiments, the composition comprises 12% to 25% ethylene acrylate based on the total weight of the composition. In some embodiments, the composition comprises 17% to 25% ethylene acrylate based on the total weight of the composition.

[0055] The ethylene / unsaturated ester copolymer may have a combination of two or more properties as described in the above embodiments.

[0056] propylene-based polymers

[0057] In addition to ionomers of ethylene / (meth)acrylic acid copolymers and ethylene / unsaturated ester copolymers, the compositions of the present invention also comprise a propylene-based polymer comprising a copolymer of propylene and a comonomer including ethylene, butene, hexene, or octene and possessing certain properties. The propylene-based polymer has a molecular weight distribution (MWD) of less than 3.0 and a viscosity ratio greater than 7.0 (at 0.1s). -1 Viscosity at 100s -1 (viscosity below).

[0058] In some implementations, the molecular weight distribution (M) of the propylene-based polymer... w / M n The MWD (referred to as MWD) is 2.0 to 3.0. The MWD of polypropylene is determined using gel permeation chromatography (GPC) as described in the Test Methods section below. In some embodiments, the MWD is 2.3 to 2.9 or 2.4 to 2.9. In some of the foregoing embodiments, the propylene-based polymer is a copolymer comprising propylene and ethylene.

[0059] In some implementations, the viscosity ratio of the propylene-based polymer (at 0.1s) -1 Viscosity at 100s -1 The viscosity (at a given viscosity) is greater than 7.0 and at most 10.0. In some embodiments, the viscosity ratio is 7.3 to 9.5 or 7.4 to 9.5. In some of the foregoing embodiments, the propylene-based polymer is a copolymer comprising propylene and ethylene.

[0060] In some embodiments, the propylene-based polymer has a melt temperature greater than 125°C, as measured by DSC. m In some embodiments, the propylene-based polymer has a melt temperature (Tm) of 125°C to 140°C or 125°C to 135°C as measured by DSC. m In some of the foregoing embodiments, the propylene-based polymer is a copolymer comprising propylene and ethylene.

[0061] In some embodiments, the propylene-based polymer has a melt flow rate (MFR) of ≥0.5 g / 10 min, ≥1.0 g / 10 min, or ≥2.0 g / 10 min at 230 °C and a 2.16 kg load (ASTM D-1238). In some embodiments, the propylene-based polymer has a melt flow rate (MFR) of ≤30 g / 10 min, ≤20 g / 10 min, or ≤15 g / 10 min at 230 °C and a 2.16 kg load (ASTM D-1238). In some embodiments, the propylene-based polymer has a melt flow rate (MFR) of 0.5 g / 10 min to 30 g / 10 min, or 1 g / 10 min to 20 g / 10 min, or 1 g / 10 min to 15 g / 10 min, or 1 g / 10 min to 10 g / 10 min, or 5 g / 10 min to 10 g / 10 min at 230°C and a 2.16 kg load (ASTM D-1238). In some of the foregoing embodiments, the propylene-based polymer is a copolymer comprising propylene and ethylene.

[0062] In some embodiments, the propylene-based polymer has a content of ≥0.860 g / cm³. 3 or ≥0.870g / cm 3 or ≥0.875g / cm 3 or ≥0.880g / cm 3 or ≥0.885g / cm 3 The density. In some embodiments, the propylene-based polymer has a density of ≤0.910 g / cm³. 3 or ≤0.905g / cm 3 or ≤0.900g / cm 3 The density. In some embodiments, the propylene-based polymer has a density of 0.860 g / cm³. 3 Up to 0.910 g / cm 3 or 0.870 g / cm 3 Up to 0.905 g / cm 3 or 0.880 g / cm 3 Up to 0.900 g / cm 3The density. In some of the foregoing embodiments, the propylene-based polymer is a copolymer comprising propylene and ethylene.

[0063] In some embodiments, the propylene-based polymer is a copolymer comprising propylene and ethylene. In some such embodiments, the ethylene content in the propylene-based polymer is less than 5% by weight. In some such embodiments, the ethylene content in the propylene-based polymer is less than 1% by weight.

[0064] In some embodiments, the composition comprises 5% to 30% by weight of a propylene-based polymer, based on the weight of the composition. In some embodiments, the composition comprises at least 5% by weight of a propylene-based polymer, based on the weight of the composition. In some embodiments, the composition comprises up to 30% by weight of a propylene-based polymer, based on the weight of the composition. All individual values ​​and sub-ranges of 5% to 30% by weight are included and disclosed herein; for example, the amount of propylene-based polymer in the composition can be from a lower limit of 5% by weight, 10% by weight, 15% by weight, or 18% by weight to an upper limit of 20% by weight, 25% by weight, or 30% by weight. For example, in some embodiments, the amount of propylene-based polymer in the composition can be from 5% by weight to 25% by weight, based on the weight of the composition.

[0065] Examples of commercially available propylene-based polymers that can be used in various embodiments of the present invention include VERSIFY, which is commercially available from Dow Chemical Company. TM propylene-based polymers, such as VERSIFY TM 2000 and Versify TM 3000.

[0066] Propylene-based polymers can have a combination of two or more properties of the embodiments described above.

[0067] In some embodiments, the ratio of the amount of ionomer to the amount of propylene-based polymer in the composition may be important. In some embodiments, the ratio of the weight percentage of the ionomer to the weight percentage of the propylene-based polymer in the composition is from 1.3 to 15.0. In some embodiments, the ratio is from 2.0 to 14.0. In some embodiments, the ratio is from 2.8 to 13.0.

[0068] additive

[0069] In one or more embodiments, the compositions disclosed in this invention may further comprise additional components, such as one or more additives. Such additives include, but are not limited to, antistatic agents, colorants, dyes, lubricants, fillers (such as TiO2 or CaCO3), opacifiers, nucleating agents, processing aids, pigments, primary antioxidants, secondary antioxidants, UV stabilizers, anti-caking agents, slip agents, lubricants, flame retardants, antimicrobial agents, deodorizers, antifungal agents, and combinations thereof. Based on the weight of the composition containing such additives, the composition may contain from about 0.1% to about 10% of such additives by weight of the composition.

[0070] An example of a composition according to some embodiments of the invention comprises: (a) 40% to 70% by weight (based on the total weight of the composition) of an ionomer, the ionomer being an acid copolymer comprising ethylene and at least one of acrylic acid and methacrylic acid, wherein a portion of the acid groups in the acid copolymer is neutralized by metal ions and is a carboxylate, and wherein the acid copolymer comprises 5% to 30% by weight of acrylic acid and methacrylic acid prior to the neutralization of the acid groups by metal ions; (b) 8% to 30% by weight (based on the total weight of the composition) of an ethylene / unsaturated ester copolymer comprising ethylene vinyl acetate, ethylene acrylate, or a combination thereof; and (c) 5% to 30% by weight (based on the total weight of the composition) of a propylene-based polymer comprising a copolymer of propylene and a comonomer comprising ethylene, butene, hexene, or octene, wherein the propylene-based polymer has a molecular weight distribution (MWD) of less than 3.0 and a viscosity ratio of greater than 7.0 (at 0.1s). -1 Viscosity at 100s -1 (viscosity below).

[0071] Another example of a composition according to some embodiments of the invention comprises: (a) 50% to 65% by weight (based on the total weight of the composition) of an ionomer, the ionomer being an acid copolymer comprising ethylene and at least one of acrylic acid and methacrylic acid, wherein a portion of the acid groups in the acid copolymer is neutralized by metal ions and is a carboxylate, and wherein the acid copolymer comprises 5% to 30% by weight of acrylic acid and methacrylic acid prior to the neutralization of the acid groups by metal ions; (b) 15% to 30% by weight (based on the total weight of the composition) of an ethylene / unsaturated ester copolymer comprising ethylene vinyl acetate, ethylene acrylate, or a combination thereof; and (c) 5% to 25% by weight (based on the total weight of the composition) of a propylene-based polymer comprising a copolymer of propylene and a comonomer comprising ethylene, butene, hexene, or octene, wherein the propylene-based polymer has a molecular weight distribution (MWD) of less than 3.0 and a viscosity ratio of greater than 7.0 (at 0.1s). -1 Viscosity at 100s -1 (viscosity below).

[0072] Another example of a composition according to some embodiments of the invention comprises: (a) 40% to 70% by weight (based on the total weight of the composition) of an ionomer, the ionomer being an acid copolymer comprising ethylene and at least one of acrylic acid and methacrylic acid, wherein a portion of the acid groups in the acid copolymer is neutralized by metal ions and is a carboxylate, and wherein the acid copolymer comprises 5% to 30% by weight of acrylic acid and methacrylic acid prior to the neutralization of the acid groups by metal ions; (b) 8% to 30% by weight (based on the total weight of the composition) of an ethylene / unsaturated ester copolymer comprising ethylene vinyl acetate, ethylene acrylate, or a combination thereof; and (c) 5% to 30% by weight (based on the total weight of the composition) of a propylene-based polymer comprising a copolymer of propylene and ethylene, wherein the ethylene content in the propylene-based polymer is less than 5% by weight, and wherein the propylene-based polymer has a molecular weight distribution (MWD) of less than 3.0 and a viscosity ratio of greater than 7.0 (at 0.1s). -1 Viscosity at 100s -1 (viscosity below).

[0073] Another example of a composition according to some embodiments of the invention comprises: (a) 50% to 65% by weight (based on the total weight of the composition) of an ionomer, the ionomer being an acid copolymer comprising ethylene and at least one of acrylic acid and methacrylic acid, wherein a portion of the acid groups in the acid copolymer is neutralized by metal ions and is a carboxylate, and wherein the acid copolymer comprises 5% to 30% by weight of acrylic acid and methacrylic acid prior to the neutralization of the acid groups by metal ions; (b) 15% to 30% by weight (based on the total weight of the composition) of an ethylene / unsaturated ester copolymer comprising ethylene vinyl acetate, ethylene acrylate, or a combination thereof; and (c) 5% to 25% by weight (based on the total weight of the composition) of a propylene-based polymer comprising a copolymer of propylene and ethylene, wherein the ethylene content in the propylene-based polymer is less than 5% by weight, and wherein the propylene-based polymer has a molecular weight distribution (MWD) of less than 3.0 and a viscosity ratio of greater than 7.0 (at 0.1s). -1 Viscosity at 100s -1 (viscosity below).

[0074] Another example of a composition according to some embodiments of the invention comprises: (a) 50% to 65% by weight (based on the total weight of the composition) of an ionomer, the ionomer being an acid copolymer comprising ethylene and at least one of acrylic acid and methacrylic acid, wherein a portion of the acid groups in the acid copolymer is neutralized by a metal ion and is a carboxylate, wherein the acid copolymer comprises 5% to 30% by weight of acrylic acid and methacrylic acid prior to the neutralization of the acid groups by the metal ion, and wherein, based on the total number of acid groups in the acid copolymer, 10% to 50% of the total acrylic acid groups and methacrylic acid groups of the acid copolymer are neutralized by the metal ion; (b) 15% to 30% by weight (based on the total weight of the composition) of ethylene vinyl acetate; and (c) 5% to 25% by weight (based on the total weight of the composition) of a propylene-based polymer comprising a copolymer of propylene and ethylene, wherein the ethylene content in the propylene-based polymer is less than 5% by weight, wherein the propylene-based polymer has a molecular weight distribution (MWD) of less than 3.0 and a viscosity ratio of greater than 7.0 (at 0.1s). -1 Viscosity at 100s -1 The viscosity is below a certain value, and the ratio of the weight percentage of the ionomer in the composition to the weight percentage of the propylene-based polymer in the composition is from 1.3 to 13.0.

[0075] Another example of a composition according to some embodiments of the invention comprises: (a) 50% to 65% by weight (based on the total weight of the composition) of an ionomer, the ionomer being an acid copolymer comprising ethylene and at least one of acrylic acid and methacrylic acid, wherein a portion of the acid groups in the acid copolymer is neutralized by metal ions and is a carboxylate, wherein the acid copolymer comprises 5% to 30% by weight of acrylic acid and methacrylic acid prior to the neutralization of the acid groups by metal ions, and wherein, based on the total number of acid groups in the acid copolymer, 10% to 50% of the total acrylic acid groups and methacrylic acid groups of the acid copolymer are neutralized by metal; (b) 15% to 30% by weight (based on the total weight of the composition) of ethylene vinyl acetate; and (c) 5% to 25% by weight (based on the total weight of the composition) of a propylene-based polymer comprising a copolymer of propylene and ethylene, wherein the ethylene content in the propylene-based polymer is less than 5% by weight, wherein the propylene-based polymer has a molecular weight distribution (MWD) of less than 3.0 and a viscosity ratio of greater than 7.0 (at 0.1s). -1 Viscosity at 100s -1 The viscosity is below a certain value, and the ratio of the weight percentage of the ionomer in the composition to the weight percentage of the propylene-based polymer in the composition is from 1.3 to 13.0.

[0076] Multilayer film

[0077] This invention also relates to multilayer films formed from any of the compositions of this invention as described herein. In some embodiments, the film may be a blown film or a cast film. In some embodiments of multilayer films including the compositions disclosed herein, the multilayer film may include the compositions of this disclosure located in an outer layer and / or a layer adjacent to the outer layer. In some embodiments, the compositions of this invention may be used to provide a sealant layer in a multilayer film. For example, the compositions of this invention may be located in the outer layer of a multilayer film formed by co-extrusion of a blown film or a cast film process. The sealant layer may provide a heat-sealable surface. As used herein, a heat-sealable surface is a surface that allows the surface of the film to be heat-sealable to another surface of the same film or the surface of another film or substrate.

[0078] The amount of the inventive composition used in the membrane of this invention can depend on many factors, including, for example, other layers in the membrane, the end-use application of the membrane, etc. In some embodiments, the multilayer membrane comprises layers consisting essentially of the inventive composition.

[0079] The multilayer membranes of the present invention can have a variety of thicknesses. The thickness of the membrane can depend on many factors, including, for example, other layers in the membrane (if the membrane is a multilayer), the desired properties of the membrane, the end-use application of the membrane, the equipment that can be used to manufacture the membrane, etc. In some embodiments, the membranes of the present disclosure have a thickness of up to 10 mils. For example, the membranes can have a thickness from a lower limit of 0.25 mils, 0.5 mils, 0.7 mils, 1.0 mils, 1.75 mils, or 2.0 mils to an upper limit of 4.0 mils, 6.0 mils, 8.0 mils, or 10 mils. In the embodiments, the thickness of the membrane can be 0.25 mil to 2.0 mil, 0.25 mil to 1.75 mil, 0.25 mil to 1.0 mil, 0.25 mil to 0.7 mil, 0.25 mil to 0.5 mil, 0.5 mil to 2.0 mil, 0.5 mil to 1.75 mil, 0.5 mil to 1.0 mil, 0.5 mil to 0.7 mil, 0.7 mil to 2.0 mil, 0.7 mil to 1.75 mil, 0.7 mil to 1.0 mil, 1.0 mil to 2.0 mil, 1.0 mil to 1.75 mil, 1.75 mil to 2.0 mil, or any combination of these ranges.

[0080] In some embodiments, a multilayer film comprising at least one layer of the composition of the present invention is included, wherein the layer or multiple layers of the composition of the present invention have a thickness of 5% to 30% of the total thickness of the multilayer film.

[0081] In some embodiments, the number of layers in the membrane can depend on a number of factors, including, for example, the desired properties of the membrane, the desired thickness of the membrane, the contents of the other layers of the membrane, the end-use application of the membrane, and the equipment available for manufacturing the membrane. In various embodiments, a multilayer blown film may include up to 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11 layers.

[0082] In some embodiments, the compositions of the present invention can be used in more than one layer of the membrane. In various embodiments, other layers within the multilayer membrane of this disclosure may include LLDPE, VLDPE (very low density polyethylene), MDPE, LDPE, HDPE, HMWHDPE (high molecular weight HDPE), propylene-based polymers, polyolefin plastisol (POP), polyolefin elastomer (POE), olefin block copolymer (OBC), ethylene vinyl acetate, ethylene acrylate, ethylene methacrylate, ethylene methyl acrylate, ethylene ethyl acrylate, ethylene butyl acrylate, isobutylene, maleic anhydride-grafted polyolefins, ionomers of any of the foregoing, or combinations thereof. In some embodiments, the multilayer membrane of this disclosure may include one or more connecting layers known to those skilled in the art.

[0083] In other embodiments of the multilayer film described herein, additional layers may be adhered to, for example, a polyethylene film via an adhesive layer (sometimes in addition to the barrier layer). The adhesive layer can be used to adhere layers of different materials. For example, a barrier layer comprising an ethylene-vinyl alcohol copolymer (EVOH) may be adhered to a polyethylene material via an adhesive layer (i.e., an adhesive layer comprising maleic anhydride-grafted polyethylene). Depending on the application, the multilayer film may also include other layers typically included in the multilayer film, such as other barrier layers, structural or strength layers, sealant layers, other adhesive layers, other polyethylene layers, polypropylene layers, etc. In other embodiments, a printing layer may be included to display product details and other packaging information in various colors; this printing layer may be an ink layer applied to the film.

[0084] It should be understood that any of the aforementioned layers may further include one or more additives known to those skilled in the art, such as antioxidants, UV stabilizers, heat stabilizers, slip agents, antiblocking agents, pigments or colorants, processing aids, crosslinking catalysts, flame retardants, fillers, and foaming agents. In some embodiments, the layer contains up to 5% by weight of such additional additives.

[0085] In some embodiments, a multilayer film comprising layers formed by the compositions of the present invention described herein may be laminated onto another film substrate. The substrate may include films comprising polyester, nylon, polypropylene, polyethylene, and combinations thereof. In some embodiments, a biaxially oriented polyethylene (BOPE) substrate, a longitudinally oriented polyethylene (MDO) substrate, or a co-extruded polyethylene film may be included in the laminated structure.

[0086] In some embodiments, the multilayer film of the present invention can be corona treated and / or printed (e.g., reverse printing or surface printing) using techniques known to those skilled in the art.

[0087] In some embodiments, the multilayer films of the present invention may be uniaxial (e.g., longitudinally) or biaxially oriented using techniques known to those skilled in the art.

[0088] Products

[0089] Various embodiments of the invention also relate to articles, such as packaging, formed from or incorporated into any of the inventive compositions disclosed herein (i.e., by incorporating a multilayer film of such compositions). Such packaging may be formed from any of the inventive compositions disclosed herein (i.e., by incorporating a film of such compositions).

[0090] Examples of such articles may include flexible packaging, bags, stand-up pouches, and pre-made packaging or bags. In some embodiments, the multilayer film of the present invention can be used for food packaging. Examples of foods that may be contained in such packaging include meat, cheese, grains, nuts, snacks, juices, sauces, etc. Based on the teachings herein and the specific purpose of the packaging (e.g., the type of food, the quantity of food, etc.), such packaging can be formed using techniques known to those skilled in the art.

[0091] In some embodiments, when incorporated into articles such as packaging, the compositions of the present invention can provide peelable seal strength, clean peel (e.g., no polymer chains or strips formed during peeling) and / or consistent peel strength across different sealing temperatures, and seal against oil contamination. In some embodiments, the use of such compositions can advantageously mitigate or eliminate the formation of gauge strips during film manufacturing.

[0092] Test methods

[0093] Unless otherwise indicated herein, the following analytical methods are used to describe various aspects of the invention:

[0094] Melt Flow Index

[0095] Melt index I2 (or I2) and I 10 (Or I10) Melt flow index values ​​were measured according to ASTM D-1238 (Method B) at 190°C and under loads of 2.16 kg and 10 kg, respectively. These melt flow index values ​​are reported in g / 10 min. Melt flow rates of propylene-based polymers were measured according to ASTM D-1238 at 230°C and 2.16 kg.

[0096] density

[0097] Samples for density measurement are prepared according to ASTM D4703. According to ASTM D792, Method B involves measuring the sample within one hour of pressing it.

[0098] Comonomer content

[0099] The comonomer content in the copolymer (e.g., the amount of acrylate in ethylene acrylate) is determined based on ASTM E168.

[0100] Differential scanning calorimetry (DSC)

[0101] Differential scanning calorimetry (DSC) is used to measure the melting and crystallization behavior of polymers (e.g., ethylene-based and propylene-based polymers). First, the sample is melt-pressed (25000 lbs, for approximately 10 seconds) into a film at approximately 190 °C and then cooled to room temperature. Approximately 5 mg to 8 mg of polymer film sample is cut using a die punch, weighed, and placed in a DSC pan. The lid is screwed onto the pan to ensure a sealed atmosphere. The sample pan is placed in a calibrated DSC unit purged with nitrogen and then heated at a rate of approximately 10 °C / min to a temperature of 180 °C for PE (230 °C for PP). The sample is held at this temperature for three minutes. The sample is then cooled to -40 °C at a rate of 10 °C / min to record the crystallization trace and isothermally held at this temperature for three minutes. The sample is then reheated at a rate of 10 °C / min until completely melted. Unless otherwise specified, the peak melting point (T0) is the reference value. m The crystallization temperature (T) is determined by the second heating curve and corresponds to the temperature of the highest endothermic peak (intensity). c ) by cooling curve (peak T) c ) Determination. T was measured from the second heating curve. g Furthermore, measurements were taken at the midpoint of the inflection point transition.

[0102] Gel permeation chromatography (GPC)

[0103] The gel permeation chromatography system consisted of a Polymer Laboratories PL-210 or PL-220 instrument. The column and rotating chamber were operated at 150°C. Four Polymer Laboratories (now Agilent) 20 μm Mixed-A columns were used in series, with 1,2,4-trichlorobenzene as the solvent. Samples were prepared using a solvent containing 200 ppm butylated hydroxytoluene (BHT) at a concentration of 2 mg / mL. Sample preparation was achieved by gentle stirring at 160°C for 2 hours. The injection volume used was 200 μL, and the flow rate was 1.0 mL / min.

[0104] GPC column calibration was performed using 21 narrow molecular weight polystyrene standards ranging from 580 to 8,400,000, arranged in six "cocktail" mixtures, with individual molecular weights spaced at least tenfold apart. The standards were purchased from Polymer Laboratories (Shropshire, UK). Polystyrene standards were prepared in 50 mL solutions of 0.025 g for molecules with molecular weights equal to or greater than 1,000,000 and in 50 mL solutions of 0.05 g for molecules with molecular weights less than 1,000,000. The polystyrene standards were dissolved by gentle stirring at 80°C for 30 minutes. The narrow standard mixtures were run first, with the highest molecular weight components being run sequentially to minimize degradation. The molecular weight of polystyrene standard peaks can be converted to that of polypropylene using the following equation (as described in Williams and Ward, Journal of Polymer Science: Polymer Letters, 6, 621 (1968):

[0105] M 聚丙烯 =0.645(M) 聚苯乙烯 (EQ 1).

[0106] Based on the GPC results, using the internal IR5 detector (measurement channel) of the PolymerChar GPC-IR chromatograph, according to Equations 2 to 3, the PolymerCharGPCOne was used. TM The software performs baseline-subtracted IR chromatograms at each equidistant data collection point (i) and analyzes the polypropylene equivalent molecular weight (Mn) obtained from the calibration curve of the narrow standard at point (i) according to Equation 1 (EQ 1). (GPC) and Mw (GPC) The calculation.

[0107]

[0108]

[0109] Molecular weight distribution (MWD) is defined as weight-average molecular weight divided by number-average molecular weight (M). w-

[0110] / M n ).

[0111] Dynamic mechanical spectrum (DMS)

[0112] Viscosity measurements were performed on parallel plates using a TA instrument with ARES. The samples were compressed in air for 6.5 minutes at 190°C and 25,000 lbs pressure, and then allowed to cool on a laboratory bench. The plate thickness was approximately 3 mm. Isothermal frequency scanning measurements were performed under nitrogen purging on an ARES strain-controlled parallel plate rheometer (TA Instruments) equipped with a 25 mm parallel plate. For each measurement, the rheometer was thermally equilibrated for at least 30 minutes before the gap was zeroed. The sample was placed on the plate and allowed to melt at 190°C or 220°C for five minutes. The plate was then brought closer together to 2 mm to trim the sample, and the test was then started. The method additionally included a five-minute delay to allow for temperature equilibration. Experiments were conducted at five points every tenfold interval in the frequency range of 0.1 rad / s to 100 rad / s at 190°C or 220°C. The strain amplitude was kept constant at 5%. The stress response was analyzed based on amplitude and phase, from which the storage modulus (G'), loss modulus (G”), complex modulus (G*), dynamic complex viscosity (η*), and tanδ (or tanδ) were calculated.

[0113] Some embodiments of the present invention will now be described in detail in the following examples.

[0114] Example

[0115] As further discussed below, various compositions of the present invention and comparative compositions are prepared using the following materials:

[0116] Table 1

[0117]

[0118]

[0119] *I2 values ​​were reported for all polymers except for those with melt flow rates reported for propylene-based polymers.

[0120] DS6D81 is a random copolymer polypropylene commercially available from Braskem. D115A is a propylene homopolymer commercially available from Braskem. Exceed 1018 is an ethylene / 1-hexene copolymer commercially available from ExxonMobil. Other polyethylenes are each available from Dow Chemical Company. Ethylene vinyl acetate (EVA) is an ethylene vinyl acetate copolymer based on the total weight of the copolymer containing 28% by weight of vinyl acetate. Toppyl PB 8640M is a random copolymer of butene-1 with a low ethylene content and is commercially available from LyondellBasell. SURLYN TM1650SB is an ionomer of a copolymer of ethylene and acrylic acid, in which zinc is a metal used for neutralizing acids, and is commercially available from Dow Chemical Company. CONPOL TM 13B is an antiblocking additive commercially available from Dow Chemical Company, which contains 12.5% ​​by weight of antiblocking agent in ethylene / methacrylic acid carrier resin.

[0121] VERSIFY TM 3000 and Versify TM 2000 are propylene-based polymers, which are copolymers of propylene and ethylene and are commercially available from Dow Chemical Company. RCPP-1 is a propylene-based polymer, which is a random copolymer of propylene and ethylene prepared as described below.

[0122] Table 2 provides viscosity data for various polypropylene types:

[0123] Table 2

[0124]

[0125] Polymerization of PP-1

[0126] Continuous solution polymerization is carried out in a controlled, well-mixed reactor. A purified mixture of alkane solvents (ISOPAR E, commercially available from ExxonMobil), ethylene, propylene, and hydrogen (if used) is combined and fed into a 52-gallon reactor. The reactor feed is measured using a mass flow controller. The temperature of the feed stream is controlled by using a cooled heat exchanger before entering the reactor. The catalyst component solution is metered using a pump and a mass flow meter. The reactor is operated at a full-liquid pressure of approximately 550 psig. Upon exiting the reactor, water and additives are injected into the polymer solution to terminate the remaining polymerization reaction. Solvents and unreacted monomers are removed during a two-stage devolatilization process (polymer solution process) in the post-reactor. The polymer melt is pumped into a mold for underwater granulation. Further details are described in Tables 3 and 4 below.

[0127] Table 3: Polymerization conditions of RCPP-1

[0128]

[0129] Table 4: Polymerization conditions of RCPP-1

[0130]

[0131] Footnotes for Tables 3 and 4: 1 Standard cm 3 / minute.

[0132] 2 Catalyst: [[2',2”'-[1,2-cyclohexanediylbis(methyleneoxy-κO)]bis[3-(9H-carbazole-9-yl)-5-methyl[1,1'-biphenyl]-2-olato-κO]](2-)]dimethylhafnium.

[0133] 3 The percentage by weight of propylene converted in the reactor.

[0134] 4 Efficiency, 1,000,000 lb polymer / lb Hf.

[0135] 5 Cocatalyst-1 (Cocat 1): Dihydrogenated tallow alkyl methyl ammonium tetra-pentafluorophenyl borate (from Boulder Scientific).

[0136] 6 Cocatalyst-2 (Cocat 2): Modified methylaluminoxane (MMAO-3A, ​​from AkzoNobel).

[0137] 7 Polymerization rate.

[0138] The following inventive and comparative compositions were prepared from the above materials:

[0139] Table 5

[0140]

[0141]

[0142] Mixing

[0143] The compositions of the present invention and comparative compositions in Table 5 were prepared using the following compounding process. The compounding process (melt blending of different resins) was performed on a Coperion ZSK 26 twin-screw extruder to prepare compositions of ionomers, ethylene vinyl acetate (EVA), and propylene-based polymers. 2.5% by weight of CONPOL was also added during compounding. TM13B. Each section of the extruder has a barrel length of 100 mm, with 15 sections constituting the entire extruder. The screw diameter is 25.5 mm, with a thread depth of 4.55 mm. The feed rate is 20 lbs / hour, and the screw operates at 300 rpm. The melt pressure is 330 psi to 350 psi, and the melt temperature is 205°C to 215°C. The extruded filament (extrudate) is passed through a water bath and then granulated. The granulated material is purged with nitrogen overnight to achieve drying, and then sealed and stored in plastic-lined paper bags. The finished composition is then formed into a film using the following film manufacturing process.

[0144] Membrane manufacturing and lamination

[0145] A bilayer film is manufactured using a Labtech blown film production line, wherein each film comprises a body layer and a sealant layer. The total thickness of the film is 2 mils, with the sealant layer being 0.4 mils, which flows within the bubble during the blown film process. The sealant layer consists of a specific inventive composition or comparative composition prepared as described above. The body layer is made of AFFINITY. TM PL 1880G polyolefin plastide (Dow Chemical Company) is manufactured with a thickness of 1.6 mils. Melt temperature is 200°C to 210°C. AFFINITY TM The outer body layer of 1880G is subjected to corona treatment during the blown film process. Bilayer co-extruded films are prepared using each of the compositions of the present invention and comparative compositions described above.

[0146] Then, each bilayer co-extruded film is laminated into an oriented polyethylene terephthalate (OPET) film (12µm thick) using a Labo Combi lamination coating machine. ADCOTE TM 577 (Dow Chemical Company) adhesive is applied to the base layer (AFFINITY) TM The bilayer co-extruded film was bonded to OPET on the surface of PL 1880G. The adhesive was applied at a weight of 1.7 lbs / ream to 3.0 lbs / ream. The roll gap temperature and web temperature were 120℉, and the line speed was 100 ft / min. The samples were cured for 4 days before the heat seal test.

[0147] Using comparative composition H (containing polybutene-1) to manufacture blown or cast films may result in a high likelihood of gauge bands (defects or quality issues) forming during film manufacturing.

[0148] Heat seal strength test

[0149] According to AS TMethod F88 was used to test the thermal seal strength of the membrane. The sealant side (using the specified inventive composition or comparative composition) of an OPET laminated co-extruded film was sealed at a sealing pressure of 40 psi and at four different sealing temperatures: 104°C, 121°C, 150°C, and 177°C for a residence time of 0.5 seconds. The sealed samples were aged overnight (23°C, 50% relative humidity) and then cut into strips one inch wide longitudinally from the multilayer film. The strips were then pulled at a rate of 10 in / min on an Instron machine using the holding method described in Technique A of ASTM F88. The mean peak load and failure displacement of five replicate test samples were recorded. The results are shown in Table 6.

[0150] Table 6

[0151]

[0152]

[0153] Membranes prepared using the compositions of the present invention advantageously exhibit a heat seal strength of less than 1.0 lb / in at sealing temperatures of 120°C, 150°C, and 177°C, indicating that the compositions of the present invention provide a peelable seal. Membranes prepared using the compositions of the present invention also advantageously exhibit a seal strength Δ (heat seal strength difference) of less than 0.3 lb / in between sealing temperatures of 177°C and 120°C, indicating that the compositions of the present invention provide a peelable seal (consistent peel strength at different temperatures) at both low and high sealing temperatures. Membranes prepared using the compositions of the present invention also advantageously exhibit a displacement of less than 0.6 inches at sealing temperatures of 120°C, 150°C, or 177°C, indicating clean peeling (minimum line formation during the peeling process).

Claims

1. A composition comprising: (a) an ionomer, the ionomer being an acid copolymer comprising ethylene and at least one of acrylic acid and methacrylic acid, wherein a portion of acid groups in the acid copolymer are neutralized by metal ions and are carboxylate salts, and wherein the acid copolymer comprises 5 to 30 weight percent of acrylic acid and methacrylic acid before the acid groups are neutralized by metal ions; (b) an ethylene / unsaturated ester copolymer comprising ethylene ethyl vinyl acetate, ethylene acrylate, or a combination thereof; and (c) a propylene-based polymer comprising a copolymer of propylene and a comonomer, the comonomer including ethylene, butene, hexene, or octene, wherein the propylene-based polymer has a molecular weight distribution, MWD, of less than 3.0 and a viscosity ratio of viscosity at 0.1 s -1 under to viscosity at 100 s -1 under of greater than 7.

0.

2. The composition of claim 1, wherein the propylene-based polymer has a melting point Tm greater than 125°C m .

3. The composition of claim 1 or claim 2, wherein the propylene-based polymer is a copolymer of propylene and ethylene, and wherein the ethylene content in the propylene-based polymer is less than 5 weight percent.

4. The composition of claim 1 or claim 2, wherein the metal ions used to neutralize the acrylic acid or methacrylic acid in the ionomer comprise zinc, sodium, lithium, magnesium, or a combination thereof.

5. The composition of claim 1 or claim 2, wherein 10 to 60 percent of the total acrylic acid and methacrylic acid groups of the acid copolymer are neutralized by the metal ions, based on the total number of acid groups of the acid copolymer.

6. The composition of claim 1 or claim 2, wherein the ethylene / unsaturated ester copolymer is ethylene ethyl vinyl acetate, and the ethylene ethyl vinyl acetate comprises 8 to 30 weight percent of vinyl acetate.

7. The composition of claim 1 or claim 2, wherein the ethylene / unsaturated ester copolymer is ethylene acrylate, and the ethylene acrylate comprises 8 to 25 weight percent of acrylate.

8. The composition of claim 1 or claim 2, wherein the propylene-based polymer has a melt flow rate of 0.5 to 30 grams per 10 minutes.

9. The composition of claim 1 or claim 2, wherein the composition comprises 40 to 70 weight percent of the ionomer, based on the total weight of the composition.

10. The composition of claim 1 or claim 2, wherein the composition comprises 10 to 40 weight percent of the ethylene / unsaturated ester copolymer, based on the total weight of the composition.

11. The composition of claim 1 or claim 2, wherein the composition comprises 5 to 30 weight percent of the propylene-based polymer, based on the total weight of the composition.

12. The composition of claim 1 or claim 2, wherein the ratio of the weight percent of ionomer in the composition to the weight percent of the propylene-based polymer in the composition is 1.3 to 15.

0.

13. A multi-layer film, wherein at least one layer of the film comprises the composition of any one of claims 1 to 12.

14. An article comprising the multi-layer film of claim 13.

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