Multilayer structure and article with coating

Abstract

The present invention provides a multilayer structure and articles formed therefrom. The multilayer structure according to the embodiments disclosed herein includes a substrate layer and a coating layer, wherein the substrate layer is coated with the coating layer. The coating layer includes a blend of high pressure low density polyethylene and a masterbatch composition. When the coating layer is coated onto the substrate layer, the coating layer can have improved neck-in reduction and maintenance or improvement of draw down during processing.

Description

Technical Field

[0001] This invention relates to multilayer structures comprising a substrate layer and a coating, to articles comprising such multilayer structures, and to methods for preparing such multilayer structures. Background Technology

[0002] Multilayer structures, including extruded coated substrates (i.e., substrate layers coated with a coating), are widely used in packaging applications. To prepare such structures, a polyolefin coating can be adhered to or applied to the substrate via extrusion coating. When added to the substrate layer, the coating can improve or impart desired properties (e.g., barrier, sealing, and toughness properties). However, there are challenges in producing and manufacturing extruded coated substrates. For example, low-density polyethylene (LDPE) is commonly used as a polyolefin coating due to its high melt strength and the presence of long-chain branching. However, extruding LDPE onto a substrate (e.g., a film) can lead to increased necking when the production line is running at its maximum target speed. Therefore, there remains a need for multilayer structures that incorporate coating and resin designs that exhibit reduced necking while maintaining or improving blade coating performance. Summary of the Invention

[0003] The present invention provides multilayer structures comprising a base layer and a coating, wherein the base layer is coated with the coating. According to an embodiment, the coating comprises a polyethylene composition comprising high-pressure low-density polyethylene and a masterbatch composition, and when the coating is applied to the base layer, the coating can exhibit desirable properties such as reduced necking and maintained or improved scraping performance.

[0004] In one aspect, the present invention provides a multilayer structure comprising: (a) a base layer including a substrate; and (b) a coating comprising a polyethylene composition, the polyethylene composition comprising (i) high-pressure low-density polyethylene having a density of 0.916 g / cm³. 3 Up to 0.940 g / cm 3 The density is within the range of 1.0 g / 10 min, the melt index (I2) is within the range of 2.0 g / 10 min to 30.0 g / 10 min, and the number of vinyl groups is less than 0.20 per 1,000 total carbon atoms; and (ii) a masterbatch composition comprising a free radical generator and a polyethylene resin, wherein the free radical generator has a half-life of less than 200 seconds at 220 °C and a decomposition energy greater than -250 kJ / mol, and wherein the polyethylene resin has a density within the range of 0.900 g / cm³. 3 Up to 0.970 g / cm 3 The density is within the range of 0.01 g / 10 min and the melt index is within the range of 100 g / 10 min; wherein the substrate is coated with the coating.

[0005] In another aspect, the present invention provides an article of manufacture, such as packaging, which includes any of the multilayer structures of the multilayer structures of the present invention disclosed herein.

[0006] In another aspect, the present invention provides a method for forming the multilayer structure of the present invention, the method comprising: (a) providing high-pressure low-density polyethylene, the high-pressure low-density polyethylene having a density of 0.916 g / cm³. 3 Up to 0.940 g / cm 3 (a) A density within the range of 0.900 g / cm³, a melt index (I²) within the range of 2.0 g / 10 min to 30.0 g / 10 min, and less than 0.20 vinyl groups / 1,000 total carbon atoms; (b) A masterbatch composition comprising a free radical generator and a polyethylene resin, wherein the free radical generator has a half-life of less than 200 seconds at 220 °C and a decomposition energy greater than -250 kJ / mol, and wherein the polyethylene resin has a density within the range of 0.900 g / cm³, a melt index (I²) within the range of 2.0 g / 10 min to 30.0 g / 10 min, and less than 0.20 vinyl groups / 1,000 total carbon atoms; 3 Up to 0.970 g / cm 3 (c) a density within the range of 0.01 g / 10 min and a melt index within the range of 100 g / 10 min; (d) reacting the high-pressure low-density polyethylene with the masterbatch composition to form a polyethylene composition; and (e) extruding the polyethylene composition as a coating onto a base layer including a substrate to form the multilayer structure.

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

[0008] The disclosed multilayer structures, articles, and methods for preparing such multilayer structures are described in more detail below. However, this disclosure should not be construed as limiting the embodiments set forth below.

[0009] As used herein, 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 (used to refer to a polymer prepared from only one type of monomer) and the term copolymer or interpolymer. Trace impurities (e.g., catalyst residues) may be incorporated into and / or within a 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.

[0010] As used herein, the term "polyethylene" or "ethylene-based polymer" should mean a polymer comprising a majority amount (>50 mol%) of units derived from ethylene monomers. This includes polyethylene homopolymers or copolymers (meaning units derived from two or more comonomers). 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); single-point catalytic linear low-density polyethylene, including linear and substantially linear low-density resins (m-LLDPE); ethylene-based plastomers (POP) and ethylene-based elastomers (POE); medium-density polyethylene (MDPE); and high-density polyethylene (HDPE).

[0011] As used herein, the term "high-pressure low-density polyethylene" should refer to polyethylene partially or fully 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). As used herein, high-pressure low-density polyethylene has a density of 0.916 g / cm³. 3 Up to 0.940 g / cm 3 The density within the range.

[0012] As used herein, the term "multilayer structure" refers to any structure having more than one layer. For example, a multilayer structure can have two, three, four, five, or more layers. A multilayer structure can be described as having layers represented by letters. For example, a three-layer structure having a core layer B and two outer layers A and C can be designated as A / B / C. Similarly, a structure having two core layers B and C and two outer layers A and D is represented as A / B / C / D. The multilayer structures disclosed herein include structures comprising a coating layer and a substrate layer.

[0013] 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.

[0014] In an embodiment, the present invention provides a multilayer structure comprising: (a) a base layer including a substrate; and (b) a coating comprising a polyethylene composition, the polyethylene composition comprising (i) high-pressure low-density polyethylene having a density of 0.916 g / cm³. 3 Up to 0.940 g / cm 3 The density is within the range of 1.0 g / 10 min, the melt index (I2) is within the range of 2.0 g / 10 min to 30.0 g / 10 min, and the number of vinyl groups is less than 0.20 per 1,000 total carbon atoms; and (ii) a masterbatch composition comprising a free radical generator and a polyethylene resin, wherein the free radical generator has a half-life of less than 200 seconds at 220 °C and a decomposition energy greater than -250 kJ / mol, and wherein the polyethylene resin has a density within the range of 0.900 g / cm³. 3 Up to 0.970 g / cm 3 The density is within the range of 0.01 g / 10 min to 100 g / 10 min; wherein the base layer is coated with the coating. Without wishing to be bound by any particular theory, it is believed that blends of specific high-pressure low-density polyethylene with specific masterbatch compositions having free radical generators contribute to reduced necking and maintained or improved scraping compared to multilayer structures comprising coatings without blends and having low-density polyethylene or linear low-density polyethylene.

[0015] The multilayer structure of the present invention may include a combination of two or more embodiments described herein.

[0016] In other embodiments, the present invention relates to an article of manufacture, such as packaging. In some embodiments, the article of manufacture includes any of the multilayer structures of the invention disclosed herein. The article of manufacture may include a combination of two or more embodiments as described herein.

[0017] basal layer

[0018] The multilayer structure of the present invention includes a base layer comprising a substrate. A coating is applied to the base layer using techniques known in the art, such as extrusion coating (i.e., the base layer is coated with a coating).

[0019] In the implementation scheme, the substrate of the base layer may include at least one of the following: membrane, nonwoven fabric, woven fabric, loose cloth, foil, carpet, plastic, saline, paper, cellulose, or metal.

[0020] coating

[0021] The multilayer structure of the present invention includes a coating. The coating comprises a polyethylene composition. The polyethylene composition comprises (i) high-pressure low-density polyethylene having a density of 0.916 g / cm³. 3 Up to 0.940 g / cm 3 The density is within the range of 1.0 g / 10 min, the melt index (I2) is within the range of 2.0 g / 10 min to 30.0 g / 10 min, and the number of vinyl groups is less than 0.20 per 1,000 total carbon atoms; and (ii) a masterbatch composition comprising a free radical generator and a polyethylene resin, wherein the free radical generator has a half-life of less than 200 seconds at 220 °C and a decomposition energy greater than -250 kJ / mol, and wherein the polyethylene resin has a density within the range of 0.900 g / cm³. 3 Up to 0.970 g / cm 3 The density is within the range of 0.01 g / 10 min and the melt index (I2) is within the range of 100 g / 10 min. The multilayer structure includes a coating that enhances necking reduction and maintains or improves scraping.

[0022] The polyethylene composition comprises high-density polyethylene (HDPE). In embodiments, the polyethylene composition comprises 90 wt.% to 99.5 wt.% HDPE and 0.5 wt.% to 10 wt.% masterbatch composition. All individual values ​​and sub-ranges of 90 wt.% to 99.5 wt.% HDPE are disclosed and incorporated herein. For example, the polyethylene composition may comprise 90 wt.% to 99.5 wt.%, 92 wt.% to 99.5 wt.%, 95 wt.% to 99.5 wt.%, or 96 wt.% to 99.5 wt.% HDPE, wherein the wt.% is based on the total weight of the polyethylene composition. Similarly, all individual values ​​and sub-ranges of 0.5 wt.% to 10 wt.% masterbatch composition are disclosed and incorporated herein. For example, the polyethylene composition may contain 0.5 wt.% to 10 wt.%, 0.5 wt.% to 8 wt.%, 0.5 wt.% to 5 wt.%, or 0.5 wt.% to 4 wt.%, of a masterbatch composition, wherein the weight percentage (wt.%) is based on the total weight of the polyethylene composition.

[0023] In the embodiment, the high-pressure low-density polyethylene of the polyethylene composition has a density of 0.916 g / cm³. 3 Up to 0.940 g / cm 3 The density is disclosed and included herein as 0.916 g / cm³. 3 Up to 0.940 g / cm 3 All individual values ​​and sub-ranges. For example, high-density polyethylene can have 0.916 g / cm³. 3 Up to 0.940 g / cm3 0.916 g / cm 3 Up to 0.935 g / cm 3 0.916 g / cm 3 Up to 0.930 g / cm 3 0.916 g / cm 3 Up to 0.925 g / cm 3 Or 0.916 g / cm 3 Up to 0.920 g / cm 3 The density.

[0024] In embodiments, the high-pressure low-density polyethylene of the polyethylene composition has a melt index (I2) in the range of 2.0 g / 10 min to 30.0 g / 10 min. All individual values ​​and sub-ranges of 2.0 g / 10 min to 30.0 g / 10 min are disclosed and included herein. For example, the high-pressure low-density polyethylene may have a melt index (I2) in the range of 2.0 g / 10 min to 30.0 g / 10 min, 2.0 g / 10 min to 20 g / 10 min, or 0.2 g / 10 min to 10 g / 10 min.

[0025] In embodiments, the high-density polyethylene of the polyethylene composition has less than 0.20 vinyl groups / 1,000 total carbon atoms. This document discloses and includes all values ​​and sub-ranges of less than 0.20 vinyl groups / 1,000 total carbon atoms. For example, the high-density polyethylene may have less than 0.20 vinyl groups / 1,000 total carbon atoms, less than 0.18 vinyl groups / 1,000 total carbon atoms, less than 0.16 vinyl groups / 1,000 total carbon atoms, less than 0.14 vinyl groups / 1,000 total carbon atoms, less than 0.12 vinyl groups / 1,000 total carbon atoms, less than 0.10 vinyl groups / 1,000 total carbon atoms, less than 0.08 vinyl groups / 1,000 total carbon atoms, or less than 0.06 vinyl groups / 1,000 total carbon atoms, wherein the vinyl unsaturation can be measured according to the test methods described below.

[0026] In one embodiment, high-pressure low-density polyethylene (HDPE) can be polymerized in an autoclave reactor. In other embodiments, HDPE can be polymerized in a tubular reactor.

[0027] In some embodiments, examples of high-pressure low-density polyethylene that can be used in the coating polyethylene composition include DOWN, which is commercially available from The Dow Chemical Company (Midland, MI). TMLDPE 772 and AGILITY TM (For example, AGILITY) TM EC7000 and AGILITY TM EC7080) High-pressure low-density polyethylene.

[0028] The polyethylene composition comprises a masterbatch composition comprising a free radical generator and a polyethylene resin. In embodiments, the free radical generator has a half-life of less than 200 seconds at 220°C and a decomposition energy greater than (i.e., more negative than) -250 kJ / mol. In some embodiments, the free radical generator has a half-life of less than 175 seconds, 150 seconds, or 125 seconds at 220°C. In other embodiments, the free radical generator has a half-life of 60 to 200 seconds, 60 to 175 seconds, 60 to 150 seconds, 60 to 125 seconds, or 60 to 120 seconds at 220°C.

[0029] In embodiments, the radical generator may have a molecular weight of 200 Daltons to 1,000 Daltons. All individual values ​​and sub-ranges of 200 Daltons to 1,000 Daltons are included and disclosed herein. For example, in some embodiments, the radical generator may have a molecular weight of 225 to 1,000, 250 to 1,000, or 250 to 700.

[0030] In the embodiments, the free radical generator is present in an amount ranging from 5 ppm to 1000 ppm relative to the total amount of polyethylene resin. This document includes and discloses all individual values ​​and sub-ranges from 5 ppm to 1000 ppm; for example, the amount of free radical generator relative to the total amount of polyethylene resin can range from a lower limit of 5 ppm, 10 ppm, 20 ppm, 30 ppm, 50 ppm, 80 ppm, 100 ppm, 200 ppm, 300 ppm, 400 ppm, 500 ppm, 600 ppm, 700 ppm, 800 ppm, or 900 ppm to an upper limit of 15 ppm, 25 ppm, 30 ppm, 35 ppm, 50 ppm, 60 ppm, 65 ppm, 75 ppm, 100 ppm, 150 ppm, 250 ppm, 350 ppm, 450 ppm, 550 ppm, 650 ppm, 750 ppm, 850 ppm, 950 ppm, or 1000 ppm.

[0031] In the embodiments described herein, the free radical generator may be a cyclic peroxide. An example of a suitable cyclic peroxide can be represented by the following formula:

[0032]

[0033] R1-R6 are independently hydrogen or inertly substituted or unsubstituted C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl, C7-C20 aralkyl, or C7-C20 alkylaryl. Representative inert substituents in R1-R6 are hydroxyl, C1-C20 alkoxy, straight-chain or branched C1-C20 alkyl, C6-C20 aryloxy, halogen, ester, carboxyl, nitrile, and amide. In some embodiments, R1-R6 are each independently a lower alkyl group, including, for example, C1-C10 alkyl or C1-C4 alkyl.

[0034] Some of the cyclic peroxides described herein are commercially available, but others can be prepared by contacting a ketone with hydrogen peroxide, as described in USP 3,003,000; Uhlmann, 3rd ed., Vol. 13, pp. 256-57 (1962); "Studies in Organic Peroxides XXV Preparation, Separation and Identification of Peroxides Derived from Methyl Ethyl Ketone and Hydrogen Peroxide", Milas, NA and Golubovic, A., Journal of the American Chemical Society (J. Am. Chem. Soc.), Vol. 81, pp. 5824-26 (1959); "Organic Peroxides ( Peroxides”, Swern, D. (ed.), Wiley-Interscience, New York (1970); and Houben-Weyl, Method of Organic Chemistry, 1 El 3, Vol. 1, p. 736.

[0035] Examples of other cyclic peroxides include those derived from acetone, methyl pentyl ketone, methyl heptayl ketone, methyl hexyl ketone, methyl propyl ketone, methyl butyl ketone, diethyl ketone, methyl ethyl ketone, methyl octyl ketone, methyl nonyl ketone, methyl decyl ketone, and methyl undecyl ketone. Cyclic peroxides can be used alone or in combination with each other.

[0036] In some embodiments, the cyclic peroxide may be 3,6,9-triethyl-3-6-9-trimethyl-1,4,7-triperoxynonane, which is commercially available from AkzoNobel under the trade name TRIGONOX 301. The cyclic peroxides used herein may be liquids, solids, or pastes, depending on the melting points of the peroxide and a diluent (if present), in which the peroxide is carried.

[0037] The polyethylene resin in the masterbatch composition has a content of 0.900 g / cm³. 3 Up to 0.970 g / cm 3 The density is within the range of 0.01 g / 10 min to 100 g / 10 min. The melt index (I2) is included and disclosed herein at 0.900 g / cm³. 3 Up to 0.970 g / cm 3 The density range and all individual values ​​and sub-ranges of the melt index in the range of 0.01 g / 10 min to 100 g / 10 min. For example, in some embodiments, the density is 0.900 g / cm³. 3 0.902 g / cm 3 0.905g / cm 3 0.907 g / cm 3 0.910 g / cm 3 0.912 g / cm 3 0.915g / cm 3 0.920g / cm 3 0.925g / cm 3 0.930g / cm 3 0.935g / cm 3 Or 0.940 g / cm 3 The lower limit is 0.970 g / cm³. 3 0.965g / cm 3 0.960 g / cm 3 0.955g / cm 3 0.950g / cm 3 0.945g / cm 3 0.942 g / cm 3 0.940 g / cm 3 0.937g / cm 3 0.935g / cm 3 0.930g / cm 3 0.927g / cm 3 0.925g / cm 3 0.922g / cm 3Or 0.920 g / cm 3 Within the upper limit range. In other embodiments, the density is 0.905 g / cm³. 3 Up to 0.965 g / cm 3 0.905g / cm 3 Up to 0.960 g / cm 3 0.907 g / cm 3 Up to 0.960 g / cm 3 0.910 g / cm 3 Up to 0.955 g / cm 3 0.910 g / cm 3 Up to 0.950 g / cm 3 0.910 g / cm 3 Up to 0.947 g / cm 3 0.910 g / cm 3 Up to 0.945 g / cm 3 0.910 g / cm 3 Up to 0.9420 g / cm 3 Or 0.910 g / cm 3 Up to 0.940 g / cm 3 The range is specified. For example, in some embodiments, the melt index (I2) is in the range of a lower limit of 0.01, 0.05, 0.1, 0.5, 1, 3, 5, 7, 10, 12, 15, 18, 20, 23, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85 or 90 to an upper limit of 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 27, 25, 22, 20, 17, 15, 12, 10, 8, 5, 2, 1, 0.9, 0.7 or 0.5. In other embodiments, the melt index (I2) is in the range of 0.05 g / 10 min to 30 g / 10 min, 0.1 g / 10 min to 30 g / 10 min, 0.1 g / 10 min to 25 g / 10 min, 0.1 g / 10 min to 20 g / 10 min, 0.1 g / 10 min to 18 g / 10 min, 0.1 g / 15 min to 30 g / 10 min, 0.25 g / 10 min to 15 g / 10 min, 0.25 g / 10 min to 12 g / 10 min, 0.25 g / 10 min to 10 g / 10 min, 0.25 g / 10 min to 8 g / 10 min, and 0.25 g / 10 min to 5 g / 10 min.

[0038] The polyethylene resin can be low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), or combinations thereof. In some embodiments, the polyethylene resin is LDPE. In other embodiments, the polyethylene is LLDPE. In still other embodiments, the polyethylene is MDPE or HDPE.

[0039] In embodiments of this document where the polyethylene resin is LLDPE, the LLDPE may be uniformly branched or non-uniformly branched and / or unimodal or multimodal (e.g., bimodal) polyethylene. Linear low-density polyethylene comprises ethylene homopolymers, interpolymers of ethylene and at least one comonomer, and blends thereof. Examples of suitable comonomers may include α-olefins. Suitable α-olefins may include α-olefins containing 3 to 20 carbon atoms (C3-C20). For example, α-olefins may be C4-C20 α-olefins, C4-C12 α-olefins, C3-C10 α-olefins, C3-C8 α-olefins, C4-C8 α-olefins, or C6-C8 α-olefins. In some embodiments, the linear low-density polyethylene is an ethylene / α-olefin copolymer, wherein the α-olefin is selected from the group consisting of propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, and 1-decene. In other embodiments, the linear low-density polyethylene is an ethylene / α-olefin copolymer, wherein the α-olefin is selected from the group consisting of propylene, 1-butene, 1-hexene, and 1-octene. In yet another embodiment, the linear low-density polyethylene is an ethylene / α-olefin copolymer, wherein the α-olefin is selected from the group consisting of 1-hexene and 1-octene.

[0040] Linear low-density polyethylene (LLDPE) can be prepared by gas-phase, solution-phase, or slurry polymerization processes, or any combination thereof, using any type of reactor or reactor configuration known in the art (e.g., parallel or series fluidized bed gas-phase reactors, loop reactors, stirred tank reactors, batch reactors, and / or any combination thereof). In some embodiments, gas-phase or slurry-phase reactors are used. Suitable LLDPE can be prepared according to the process described on pages 15-17 and 20-22 of WO 2005 / 111291 A1, which is incorporated herein by reference. Catalysts used to prepare the LLDPE described herein may include Ziegler-Natta catalysts, chromium catalysts, metallocene catalysts, confined geometry catalysts, or single-point catalysts. Examples of suitable linear low-density polyethylene include: substantially linear ethylene polymers, which are further defined in U.S. Patent Nos. 5,272,236, 5,278,272, 5,582,923, 5,733,155, and EP2,653,392, and these patents are incorporated herein by reference; homogeneously branched linear ethylene polymer compositions, such as the homogeneously branched linear ethylene polymer compositions of U.S. Patent No. 3,645,992, which is incorporated herein by reference; non-homogeneously branched ethylene polymers, such as non-homogeneously branched ethylene polymers prepared according to the process disclosed in U.S. Patent No. 4,076,698; and / or blends thereof (such as blends disclosed in U.S. Patent Nos. 3,914,342 or 5,854,045), all of which are incorporated herein by reference. In some embodiments, linear low-density polyethylene may include: ELITE, marketed by Dow Chemical Company. TM ELITE TM AT, ATTANE TM AFFINITY TM FLEXOMER TM Or DOWLEX TM Resins, including, for example, ELITE TM 5100G or 5400G resin, ELITE TM AT 6401, ATTANE TM 4201 or 4202 resin, AFFINITY TM 1840 and DOWLEX TM 2020, 2045G, 2049G, or 2685 resin; EXCEED sold by ExxonMobil Corporation. TM or ENABLE TMResins, including, for example, EXCEED TM 1012, 1018 or 1023JA resin and ENABLE TM 27-03, 27-05, or 35-05 resins; linear low-density polyethylene resins sold by Westlake Chemical Corporation, including, for example, LLDPELF1020 or HIFOR Xtreme. TM SC74836 resin; linear low-density polyethylene resins sold by LyondellBasell Industries, including, for example, PETROTHENE. TM GA501 and LP540200 resins and ALATHON TM L5005 resin; linear low-density polyethylene resins sold by Nova Chemicals Corp., including, for example, SCLAIR. TM FP120 and NOVAPOL TM TF-Y534; a linear low-density polyethylene resin marketed by Chevron Phillips Chemical Company, LLC, including, for example, mPACT TM D139 or D350 resin and MARFLEX TM HHM TR-130 resin; linear low-density polyethylene resins sold by Borealis AG, including, for example, BORSTAR. TM FB 2310 resin.

[0041] In embodiments thereof where the polyethylene resin is MDPE, the MDPE can be an ethylene homopolymer or a copolymer of ethylene and an α-olefin. Suitable α-olefins can include α-olefins containing 3 to 20 carbon atoms (C3-C20). For example, the α-olefin can be a C4-C20 α-olefin, a C4-C12 α-olefin, a C3-C10 α-olefin, a C3-C8 α-olefin, a C4-C8 α-olefin, or a C6-C8 α-olefin. In some embodiments, the MDPE is an ethylene / α-olefin copolymer wherein the α-olefin is selected from the group consisting of propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, and 1-decene. In other embodiments, the MDPE is an ethylene / α-olefin copolymer wherein the α-olefin is selected from the group consisting of propylene, 1-butene, 1-hexene, and 1-octene. The MDPE can have a content of 0.923 g / cm³. 3 and 0.935g / cm 3The density. This document includes and discloses all individual values ​​and subranges.

[0042] MDPE can be prepared by gas-phase, solution-phase, or slurry polymerization processes, or any combination thereof, using any type of reactor or reactor configuration known in the art (e.g., parallel or series fluidized bed gas-phase reactors, loop reactors, stirred tank reactors, batch reactors, and / or any combination thereof). In some embodiments, gas-phase or slurry-phase reactors are used. In some embodiments, MDPE is prepared in a solution process operating in a parallel or series dual-reactor mode. MDPE can also be prepared by high-pressure radical polymerization. Methods for preparing MDPE by high-pressure radical polymerization can be found in US2004 / 0054097, which is incorporated herein by reference, and can be carried out in autoclaves or tubular reactors, or any combination thereof. Catalysts used to prepare the MDPE described herein may include Ziegler-Natta catalysts, metallocene catalysts, confined geometry catalysts, unit point catalysts, or chromium-based catalysts. Exemplary suitable MDPE resins may include resins sold by Dow Chemical Company, such as DOWLEX. TM 2038.68G or DOWLEX TM 2042G; Resins sold by LyondellBasell Industries, Inc. (Houston, TX), such as PETROTHENE TM L3035; ENABLE sold by The ExxonMobil Chemical Company (Houston, Texas). TM Resins; resins sold by Chevron Phillips Chemical Company, such as MARFLEX. TM TR-130; and resins such as HF 513, HT 514, and HR 515 sold by Total Petrochemicals & Refining USA Inc. Other exemplary MDPE resins are described in US2014 / 0255674, which is incorporated herein by reference.

[0043] In embodiments thereof where the polyethylene resin is HDPE, the HDPE may also be an ethylene homopolymer or a copolymer of ethylene and an α-olefin. Suitable α-olefins may include α-olefins containing 3 to 20 carbon atoms (C3-C20). For example, the α-olefin may be C4-C20 α-olefins, C4-C12 α-olefins, C3-C10 α-olefins, C3-C8 α-olefins, C4-C8 α-olefins, or C6-C8 α-olefins. In some embodiments, the HDPE is an ethylene / α-olefin copolymer, wherein the α-olefin is selected from the group consisting of propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, and 1-decene. In other embodiments, the HDPE is an ethylene / α-olefin copolymer, wherein the α-olefin is selected from the group consisting of propylene, 1-butene, 1-hexene, and 1-octene. The amount of comonomer used will depend on the desired density of the HDPE polymer and the specific comonomer selected, taking into account processing conditions such as temperature and pressure, as well as other factors such as the presence or absence of telomeres, which will be apparent to those skilled in the art possessing this disclosure. HDPE can have a density of 0.935 g / cm³. 3 Up to 0.975 g / cm 3 The density. This document includes and discloses all individual values ​​and subranges.

[0044] HDPE can be prepared by gas-phase, solution-phase, or slurry polymerization processes, or any combination thereof, using any type of reactor or reactor configuration known in the art (e.g., parallel or series fluidized bed gas-phase reactors, loop reactors, stirred tank reactors, batch reactors, and / or any combination thereof). In some embodiments, gas-phase or slurry-phase reactors are used. In some embodiments, HDPE is prepared in a solution process operating in a parallel or series dual-reactor mode. Catalysts used to prepare the HDPE described herein may include Ziegler-Natta catalysts, metallocene catalysts, confined geometry catalysts, single-point catalysts, or chromium-based catalysts. HDPE can be unimodal, bimodal, or multimodal. Exemplary commercially available HDPE resins include, for example, ELITE, available from Dow Chemical Company (Midland, Michigan). TM 5940G, ELITE TM5960G, HDPE 35454L, HDPE 82054, HDPE DGDA-2484NT, DGDA-2485NT, DGDA-5004NT, ​​DGDB-2480NT resins; L5885 and M6020 HDPE resins from Equistar Chemicals, LP; ALATHON resins from LyondellBasell Industries, Houston, Texas. TM L5005; and MARFLEX from Chevron Phillips Chemicals. TM HDPE HHM TR-130. Other exemplary HDPE resins are described in US7,812,094, which is incorporated herein by reference.

[0045] Multilayer structure and formation method

[0046] In some embodiments, the multilayer structure of the present invention includes a base layer and a coating deposited thereon (as described above). Incorporation of a specific masterbatch and a high-pressure low-density polyethylene blend into the coating advantageously provides improved necking reduction during processing, which benefits the processability of the structure.

[0047] A method for forming a multilayer structure is disclosed. The method includes (a) providing high-pressure low-density polyethylene (as described above), the high-pressure low-density polyethylene having a density of 0.916 g / cm³. 3 Up to 0.940 g / cm 3 (a) A density within the range of 0.900 g / cm³, a melt index (I²) within the range of 2.0 g / 10 min to 30.0 g / 10 min, and less than 0.20 vinyl groups / 1,000 total carbon atoms; (b) A masterbatch composition (as described above) comprising a free radical generator and a polyethylene resin, wherein the free radical generator has a half-life of less than 200 seconds at 220 °C and a decomposition energy greater than -250 kJ / mol, and wherein the polyethylene resin has a density within the range of 0.900 g / cm³, a melt index (I²) within the range of 2.0 g / 10 min to 30.0 g / 10 min, and less than 0.20 vinyl groups / 1,000 total carbon atoms; 3 Up to 0.970 g / cm 3 (c) a density within the range of 0.01 g / 10 min and a melt index within the range of 100 g / 10 min; (d) reacting the high-pressure low-density polyethylene with the masterbatch composition to form a polyethylene composition; and (e) extruding the polyethylene composition as a coating onto a base layer including a substrate to form the multilayer structure.

[0048] The reaction of high-density polyethylene (HDPE) with the masterbatch composition can be carried out in any conventional mixing equipment where the polymer is melted and mixed with the masterbatch. Suitable equipment is known to those skilled in the art, including, for example, mixers, kneaders, and extruders. In some embodiments, the reaction of HDPE with a free radical generator is carried out in an extruder. The extruder can also be connected to a blown film or cast film production line. In some embodiments, the reaction of HDPE with a free radical generator is carried out in an extruder connected to a blown film or cast film production line.

[0049] Exemplary extruders or kneaders include, for example, single-screw extruders, counter-rotating and co-rotating twin-screw extruders, planetary gear extruders, annular extruders, or co-kneaders. Suitable extruders and kneaders are further described, for example, in *Handbuch der Kunststoftextrusion*, Volume 1, Grundlagen, edited by F. Hensen, W. Knappe, and H. Potente, 1989, pp. 3-7, ISBN 3-446-14339-4 (Volume 2, *Extrusion Sanlagen*, 1986, ISBN 3-446-14329-7). In the embodiments described herein, the screw length can be 1-60 times the screw diameter, or 35-48 times the screw diameter. The screw rotation speed can be in the range of 10 rpm to 600 rpm or 25 rpm to 300 rpm. Maximum production capacity depends on the screw diameter, rotation speed, and drive force. The process of the present invention can also be carried out at levels below the maximum production volume by changing the mentioned parameters or using a weighing machine for delivering the dosage.

[0050] High-density polyethylene (HDPE) and masterbatch can react in ratios from 60:40 to 99.9:0.1. All individual values ​​and sub-ranges are included and disclosed herein. For example, in some embodiments, HDPE and masterbatch can react in ratios from 65:35 to 99.9:0.1, 65:35 to 99.9:0.1, 70:30 to 99.9:0.1, 75:25 to 99.9:0.1, 80:20 to 99.9:0.1, 85:15 to 99.9:0.1, 90:10 to 99.9:0.1, 95:5 to 99.9:0.1, 97:3 to 99.9:0.1, 95:5 to 99:1, or 97:3 to 99:1. High-density polyethylene (HDPE) and masterbatch can also react such that the amount of masterbatch in the HDPE ranges from 0.1 wt.% to 40 wt.%. All individual values ​​and sub-ranges are included and disclosed herein. For example, in some embodiments, HDPE and masterbatch can react such that the amount of masterbatch in the first polyethylene resin ranges from 0.1 wt.% to 35 wt.%, 0.1 wt.% to 30 wt.%, 0.1 wt.% to 25 wt.%, 0.1 wt.% to 20 wt.%, 0.1 wt.% to 15 wt.%, 0.1 wt.% to 10 wt.%, 0.1 wt.% to 5 wt.%, 0.1 wt.% to 3 wt.%, 1 wt.% to 5 wt.%, or 1 wt.% to 3 wt.%.

[0051] The high-density polyethylene (HDPE) and masterbatch are subjected to temperatures above the polymer softening point for a sufficiently long period of time to allow the reaction between the HDPE and the free radical generator to occur. In some embodiments, the HDPE and masterbatch are subjected to temperatures less than or equal to 280°C. This document includes and discloses all individual values ​​and sub-ranges less than or equal to 280°C. For example, the temperature may be less than or equal to 280°C, 260°C, 250°C, 240°C, 220°C, 200°C, 180°C, or 160°C. In some embodiments, the temperature is 120°C to 280°C, 140°C to 280°C, 160°C to 280°C, 180°C to 280°C, or 180°C to 260°C. In alternative embodiments, the temperature is 200°C to 260°C. It should be understood that the required reaction time can vary with temperature, amount of material to be reacted, and type of equipment used. Under exemplary conditions, the time for maintaining a temperature above the polymer softening point can be from 10 seconds to 30 minutes. This document includes and discloses all individual values ​​and subranges; for example, the time can be a lower limit of 10 seconds, 20 seconds, 30 seconds, 1 minute, 5 minutes, 15 minutes, or 25 minutes to an upper limit of 45 seconds, 3 minutes, 8 minutes, 10 minutes, 12 minutes, 15 minutes, 18 minutes, 20 minutes, 23 minutes, or 30 minutes. For example, the time can be in the range of 10 seconds to 20 minutes, or alternatively, the time can be in the range of 10 seconds to 15 minutes, or alternatively, the time can be in the range of 10 seconds to 10 minutes, or alternatively, the time can be in the range of 20 seconds to 20 minutes, or alternatively, the time can be in the range of 15 minutes to 30 minutes.

[0052] In an implementation scheme, the method includes (a) providing high-pressure low-density polyethylene (as described above), the high-pressure low-density polyethylene having a density of 0.916 g / cm³. 3 Up to 0.940 g / cm 3 (a) A density within the range of 0.900 g / cm³, a melt index (I²) within the range of 2.0 g / 10 min to 30.0 g / 10 min, and less than 0.20 vinyl groups / 1,000 total carbon atoms; (b) A masterbatch composition (as described above) comprising a free radical generator and a polyethylene resin, wherein the free radical generator has a half-life of less than 200 seconds at 220 °C and a decomposition energy greater than -250 kJ / mol, and wherein the polyethylene resin has a density within the range of 0.900 g / cm³, a melt index (I²) within the range of 2.0 g / 10 min to 30.0 g / 10 min, and less than 0.20 vinyl groups / 1,000 total carbon atoms; 3 Up to 0.970 g / cm 3(c) a density within the range of 0.01 g / 10 min and a melt index within the range of 100 g / 10 min; and (d) reacting the high-pressure low-density polyethylene with the masterbatch composition to form a polyethylene composition; and (e) extruding the polyethylene composition as a coating onto a substrate layer including the substrate to form the multilayer structure, wherein during the extrusion coating of the polyethylene composition as the coating, the coating has a necking of less than 4.00 inches, or alternatively less than 3.50 inches, or alternatively less than 3.00 inches, or alternatively less than 2.50 inches at 440 ft / min.

[0053] In an implementation scheme, the method includes (a) providing high-pressure low-density polyethylene (as described above), the high-pressure low-density polyethylene having a density of 0.916 g / cm³. 3 Up to 0.940 g / cm 3 (a) A density within the range of 0.900 g / cm³, a melt index (I²) within the range of 2.0 g / 10 min to 30.0 g / 10 min, and less than 0.20 vinyl groups / 1,000 total carbon atoms; (b) A masterbatch composition (as described above) comprising a free radical generator and a polyethylene resin, wherein the free radical generator has a half-life of less than 200 seconds at 220 °C and a decomposition energy greater than -250 kJ / mol, and wherein the polyethylene resin has a density within the range of 0.900 g / cm³, a melt index (I²) within the range of 2.0 g / 10 min to 30.0 g / 10 min, and less than 0.20 vinyl groups / 1,000 total carbon atoms; 3 Up to 0.970 g / cm 3 (c) a density within the range of 0.01 g / 10 min to 100 g / 10 min; and (d) reacting the high-pressure low-density polyethylene with the masterbatch composition to form a polyethylene composition; and (e) extruding the polyethylene composition as a coating onto a substrate layer including the substrate to form the multilayer structure, wherein during the extrusion coating of the polyethylene composition as the coating, the coating has a necking of less than 3.50 inches, or alternatively less than 3.00 inches, or alternatively less than 2.50 inches at 880 feet / min.

[0054] Products

[0055] The multilayer structure of this invention can be used to form articles, such as packaging. Such articles can be formed from any of the multilayer structures described herein.

[0056] Examples of articles that can be formed from the multilayer structure of the present invention may include flexible packaging, pouches, stand-up pouches, and pre-made packaging or pouches. In some embodiments, the multilayer structure or articles of the present invention can be used for industrial packaging. Based on the teachings herein and the specific application of the packaging, techniques known to those skilled in the art can be used to form such articles.

[0057] Test methods

[0058] Unless otherwise indicated herein, the following analytical methods are used to describe various aspects of the invention:

[0059] density

[0060] Density was measured according to ASTM D792 and expressed in grams per cubic centimeter (g / cm³). 3 )express.

[0061] Melt index (I2)

[0062] Melt index or I2 is measured according to ASTM D1238 at 190°C and 2.16 kg.

[0063] Vinyl unsaturation

[0064] Samples were prepared as follows: Approximately 130 mg of sample was added to 3.25 g of 50 / 50 (by weight) tetrachloroethane-d2 / perchloroethylene containing 0.001 M Cr(AcAc)3 in a Norell 1001-7 10 mm NMR tube. The sample was purged by bubbling nitrogen through the solvent for approximately 5 minutes via a pipette inserted into the tube. The tube was capped, sealed with a Teflon tape, and then left to soak overnight at room temperature to promote sample dissolution. The sample was heated and vortexed at 115 °C to ensure homogeneity.

[0065] The experiment was conducted on a Bruker AVANCE 400MHz spectrometer equipped with a Bruker Dual DUL high-temperature CryoProbe and a sample temperature of 120°C. 1 H NMR. Two experiments were run to obtain spectra: a control spectrum for quantifying total polymer protons and a double presaturation experiment, which suppressed strong polymer backbone peaks and enabled highly sensitive spectra for quantifying end groups. The control was run with ZG pulses, 4 scans, AQ 1.64 s, and D1 (relaxation delay) 14 s. The double presaturation experiment was run with a modified pulse sequence, 100 scans, DS 4, AQ 1.64 s, D1 (presaturation time) 1 s, and D13 (relaxation delay) 13 s. Integration was performed in the region between 4.95 ppm and 5.15 ppm to determine vinyl content.

[0066] half life

[0067] Different free radical generators (FRGs) were studied as C under both isothermal conditions and temperature scanning mode using a Sensys Evo DSC instrument (Setaram, France).20 H 42 Thermal decomposition of a 10% w / w solution of (eicosane). To obtain the rate law (kinetic parameters) of the thermal decomposition of FRG, the FRG was measured at C0 in temperature scan mode within a temperature interval from 75 °C to 350 °C at five different scan rates: 1 °C / min, 2.5 °C / min, 5 °C / min, 10 °C / min, and 20 °C / min. 20 H 42 A 10% w / w solution of (eicosane) was prepared. Approximately 60 mg of sample (eicosane containing 10% w / w FRG) was placed in a 170 mL Al dish and placed in a DSC instrument at 75 °C (above the melting point of paraffin) under a nitrogen atmosphere (20 cc / min). After thermal equilibrium, the temperature was scanned according to the above temperature program, and thermochromatograms were recorded. Exothermic peaks were recorded in temperature intervals from 120 °C to 320 °C. The released heat -ΔHr (J / g) was determined from the DSC curve of each sample, which allowed for the calculation of the reaction progress / conversion rate as a function of temperature. The kinetic parameters describing the decomposition rate law were determined by the isoconversion method (using AKTS thermodynamic software, AKTS AG, Switzerland) and the best-fit parameters based on the Sestak-Berggren autocatalytic model. The activation energy E as a function of the decomposition progress α was determined using the Friedmann differential isoconversion method and the Ozawa integral isoconversion method. a (kJ / mol) and the pre-exponential factor ln A(α)·f(α)(s) -1 (-)). The general form of the Sestak-Berggren equation is given below:

[0068]

[0069] Furthermore, the activation energy E in the above equation was determined using the best-fit method. a The pre-exponential factor A and the reaction orders m and n. Then E can be used. a The parameters A, m, and n were used to calculate the FRG half-life at any temperature using AKTS thermodynamics software.

[0070] Decomposition energy and peak decomposition temperature

[0071] Differential scanning calorimetry (DSC) was used to measure the decomposition energy and peak decomposition temperature. This analysis was performed using a TA Q2000 DSC instrument equipped with an RCS (cryogenic cooling system). Samples ranging from 0.5 mg to 2 mg were placed in glass capillaries, weighed, and flame-sealed under nitrogen while being kept cool using a "cold finger" device. Analysis was then performed to determine their thermal properties.

[0072] The thermal behavior of the sample was determined by uniformly increasing the sample temperature to generate a heat flow versus temperature profile. First, the sample was heated from 0°C to 400°C at a rate of 10°C / min. Then, the sample was cooled. Next, the sample was reheated at a heating rate of 10°C / min (this is the "reheating" uniformization). Two heating profiles were recorded. The initial thermal profile was analyzed by setting a baseline point from the beginning to the end of the thermal activity. Reheating was used to help determine the start and end points of the integration.

[0073] For free radical generators, the peak temperature and total decomposition energy are recorded by integrating the area between the first thermal cycle curve and the baseline. If the decomposition is exothermic, the area between the curve and the baseline is integrated as negative due to the presence of negative heat flux; that is, the sample generates heat. If the sample is endothermic, absorbing heat, the area is integrated as positive.

[0074] The heat at the exothermic peak, divided by the purity, is used to equate to a 100% pure free radical generator.

[0075] High-temperature gel permeation chromatography (HT-GPC)

[0076] A PolymerChar (Valencia, Spain) high-temperature gel permeation chromatography system, consisting of an infrared concentration detector (IR-5), was used for MW and MWD determination. The solvent delivery pump, online solvent degassing device, autosampler, and column oven were from Agilent Technologies. The column and detector chambers were operated at 150 °C. The columns were three PLgel 10 μm Mixed-B columns (Agilent Technologies). The support solvent was 1,2,4-trichlorobenzene (TCB) at a flow rate of 1.0 mL / min. Both solvent sources used for chromatography and sample preparation contained 250 ppm of butylated hydroxytoluene (BHT) and were bubbled with nitrogen. Polyethylene samples were prepared at a target polymer concentration of 2 mg / mL by dissolving the polymer in TCB at 160 °C for 3 hours on the autosampler just before injection. The injection volume was 200 μL.

[0077] The GPC column set was calibrated using 21 polystyrene standards with narrow molecular weight distributions. The standards ranged in molecular weight from 580 g / mol to 8,400,000 g / mol and were arranged in a six-cocktail mixture, with individual molecular weights spaced at least tenfold apart. The peak molecular weights of the polystyrene standards were converted to polyethylene molecular weights using the following equation (as described in Williams and Ward, *Journal of Polymer Science: Polymer Letters*, 6, 621 (1968)):

[0078] M聚乙烯 =A(M 聚苯乙烯 ) B (1)

[0079] Here, B has a value of 1.0, and the experimentally determined value of A is approximately 0.42.

[0080] A third-order polynomial is used to fit the corresponding polyethylene-equivalent calibration points obtained from equation (1) to their observed elution volumes. The actual polynomial fit is obtained so that the logarithm of the polyethylene equivalent molecular weight is correlated with the observed elution volume (and associated power) of each polystyrene standard.

[0081] Calculate the number-average molecular weight, weight-average molecular weight, and z-average molecular weight using the following equations:

[0082]

[0083]

[0084]

[0085] Among them, Wf i It is the weight fraction of the i-th component, and M i It is the molecular weight of the i-th component. MWD is expressed as the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn).

[0086] The accurate A value is determined by adjusting the A value in equation (1) until the weight-average molecular weight of Mw calculated using equation (3) and the corresponding retention volume polynomial is consistent with the independently determined Mw value obtained from a linear homopolymer reference with a known weight-average molecular weight of 120,000 g / mol.

[0087] neck contraction

[0088] Necking is measured and reported as the difference between the width of the web at the die exit and the width of the coating after the substrate has been formed. The reduction in width is necking and is reported in inches.

[0089] scraping

[0090] Scraping is reported as the speed at which the web can be pulled before it breaks. To measure scraping, the speed of the production line is increased until the web breaks, and the speed at which the web breaks is reported as scraping in feet per minute (fpm).

[0091] Example

[0092] The following embodiments illustrate the features of this disclosure, but are not intended to limit the scope of this disclosure. The following materials are used in the embodiments.

[0093] Table 1

[0094]

[0095] *All resins in Table 1 are commercially available from Dow Chemical Company (Midland, Michigan).

[0096] **Unmeasured = NM

[0097] In addition to the high-pressure low-density polyethylene and linear low-density polyethylene polymers listed in Table 1, the masterbatch composition DOWLEX was also used. TM GM AX01. DOWLEX TM GM AX01 is commercially available from Dow Chemical Company (Midland, Michigan). TM GM AX01 comprises a free radical generator (cyclic peroxide) and polyethylene resin. The free radical generator has a half-life of 82 seconds at 220°C, a decomposition energy of -835 kJ / mol, a molecular weight of 264.3 Daltons, and a peak decomposition temperature of 208°C. The polyethylene resin in the masterbatch composition has a content of 0.920 g / cm³. 3 The density and melt index (I2) were 16 g / 10 min. A free radical generator was added at an amount of 1,000 ppm relative to the total amount of polyethylene resin to form the masterbatch composition.

[0098] By combining the high-pressure low-density polyethylene or linear low-density polymer in Table 1 with the masterbatch composition DOWLEX TM GMAX01 (“MB”) was blended, and the blend was coated onto 50 lb multi-walled brown kraft paper (including the base layer of the substrate) for extrusion coating studies to determine necking reduction. Invention Examples (Inv.Ex.) and Comparative Examples (Comp.Ex.) are provided in Table 2 below, each comprising specific amounts of blended and extruded coated onto 50 lb multi-walled brown kraft paper of LDPE and MB.

[0099] Extrusion coating tests were conducted using a Black-Clawson production line following standard coating procedures. A single-layer coating was extruded using a 3-layer EC production line and a primary 3.5-inch diameter extruder (30:1 L / D) driven by a 150HP Eurotherm drive. The main barrel consisted of six heater zones with a temperature distribution A1-16 of 180 / 230 / 285 / 315 / 315 / 315°C. A 36-inch Nordson 36-inch Autoflex VILH40 EPC die with reduced internal edge beads was used, and a die gap of 0.5 mm to 0.6 mm (0.020") and an air gap of 153 mm (6") were set. The production line is equipped with a 30" cooling roller, a pressure roller, a backing roller, and a shear cutter. Extrusion coating is run at 25 gsm at 600°C (or 315°C), a screw speed of 90 RPM, and 250 lbs / h, a 24" die width, and a 20 mil die gap, which translates to a coating thickness of 1 mil on 50 lbs multiwalled brown kraft paper at 440 ft / min.

[0100] Table 2 - Embodiments and Comparative Embodiments of the Invention

[0101] Example LDPE or LLDPE Masterbatch (MB) Comp.Ex.1 <![CDATA[100% by weight DOW TM LDPE 722]]> 0% MB by weight Comp.Ex.2 <![CDATA[100% by weight AGILITY TM EC 7000]]> 0% MB by weight Comp.Ex.3 <![CDATA[100% by weight AGILITY TM EC 7030]]> 0% MB by weight Comp.Ex.4 <![CDATA[100% by weight AGILITY TM EC 7080]]> 0% MB by weight Comp.Ex.5 <![CDATA[98 wt% ELITE TM 5815]]> 2% MB by weight Comp.Ex.6 <![CDATA[96 wt% ELITE TM 5815]]> 4% MB by weight Inv.Ex.1 <![CDATA[98 wt% DOW TM LDPE 722]]> 2% MB by weight Inv.Ex.2 <![CDATA[96 wt% DOW TM LDPE 722]]> 4% MB by weight Inv.Ex.3 <![CDATA[98 wt% AGILITY TM EC 7000]]> 2% MB by weight Inv.Ex.4 <![CDATA[96% AGILITY TM EC 7000]]> 4% MB by weight Inv.Ex.5 <![CDATA[98% AGILITY TM EC 7030]]> 2% MB by weight Inv.Ex.6 <![CDATA[96 wt% AGILITY TM EC 7030]]> 4% MB by weight Inv.Ex.7 <![CDATA[98 wt% AGILITY TM EC 7080]]> 2% MB by weight Inv.Ex.8 <![CDATA[96% AGILITY TM EC 7080]]> 4% MB by weight

[0102] During the extrusion coating of the coating (i.e., a blend of LLDPE or LDPE and MB) onto the substrate (kraft paper), the necking and scraping of the coating were measured according to the test methods described above. The results are presented in Table 3 below.

[0103] Table 3

[0104]

[0105] *Measure the maximum linear rate of the coating.

[0106] As can be seen from Table 3, Comparative Examples 1 to 4 represent five different high-pressure low-density polyethylenes typically used for extrusion coating, and when the MB composition (Examples 1 to 8 of the present invention) is added and the blend is extruded onto the substrate, necking is reduced and scraping is maintained or improved. Comparative Examples 5 and 6 comprise LLDPE, and adding the MB composition to the LLDPE does not improve necking during processing.

Claims

1. A multi-layer structure, the multi-layer structure comprising: (a) a base layer, the base layer comprising a substrate; and (b) A coating comprising a polyethylene composition, the polyethylene composition comprising: (i) Based on the total weight of the polyethylene composition, 90 wt% to 99.5 wt% of high-density polyethylene, said high-density polyethylene having a content of 0.916 g / cm³. 3 Up to 0.940 g / cm 3 Density within the range of 2.0 g / 10 min to 30.0 g / 10 min, melt index I2 within the range of 2.0 g / 10 min, and vinyl unsaturation of less than 0.10 vinyl groups / 1,000 total carbon atoms; and (ii) Based on the total weight of the polyethylene composition, 0.5 wt% to 10 wt% of a masterbatch composition comprising a free radical generator and a polyethylene resin, wherein the free radical generator has a half-life of less than 200 seconds at 220°C and a decomposition energy greater than -250 kJ / mol, and wherein the polyethylene resin has a decomposition energy of 0.900 g / cm³. 3 Up to 0.970 g / cm 3 Density within the range of 0.01 g / 10 min to 100 g / 10 min; Melt index within the range of 0.01 g / 10 min; The base layer is coated with the coating, and the density is measured according to ASTM D792, the melt index is measured according to ASTM D1238 at 190°C and 2.16 kg, and the vinyl unsaturation is determined by... 1 H NMR analysis was performed using a modified pulse sequence, 100 scans, DS 4, AQ 1.64 s, presaturation time D1 1 s, relaxation delay D13 13 s, and integration was performed over the region between 4.95 ppm and 5.15 ppm.

2. The multilayer structure according to claim 1, wherein the polyethylene composition comprises 96% to 99.5% by weight of the high-pressure low-density polyethylene and 0.5% to 4% by weight of the masterbatch composition.

3. The multilayer structure according to claim 1 or 2, wherein the amount of free radical generator is less than 100 ppm relative to the total amount of polyethylene resin.

4. The multilayer structure according to any one of claims 1 to 3, wherein the free radical generator has a half-life between 60 seconds and 120 seconds at 220°C.

5. The multilayer structure according to any one of claims 1 to 4, wherein the free radical generator has a molecular weight of 200 Daltons to 1,000 Daltons as determined by high-temperature gel permeation chromatography.

6. The multilayer structure according to any one of claims 1 to 5, wherein the free radical generator is a cyclic peroxide.

7. The multilayer structure according to any one of claims 1 to 6, wherein the substrate of the base layer comprises at least one of the following: membrane, nonwoven fabric, woven fabric, loose cloth, foil, carpet, plastic, saline, paper, cellulose or metal.

8. A method for forming a multilayer structure, the method comprising: (a) Providing 90 wt% to 99.5 wt% high-density polyethylene, said high-density polyethylene having a content of 0.916 g / cm³. 3 Up to 0.940 g / cm 3 Density within the range of 2.0 g / 10 min to 30.0 g / 10 min, melt index I2 within the range of 2.0 g / 10 min, and vinyl unsaturation of less than 0.10 vinyl groups / 1,000 total carbon atoms; (b) Providing a masterbatch composition of 0.5 wt% to 10 wt%, the masterbatch composition comprising a free radical generator and a polyethylene resin, wherein the free radical generator has a half-life of less than 200 seconds at 220°C and a decomposition energy greater than -250 kJ / mol, and wherein the polyethylene resin has a decomposition energy of 0.900 g / cm³. 3 Up to 0.970 g / cm 3 Density within the range of 0.01 g / 10 min to 100 g / 10 min; Melt index within the range of 0.01 g / 10 min; (c) Reacting the high-pressure low-density polyethylene with the masterbatch composition to form a polyethylene composition, wherein wt% is based on the total weight of the polyethylene composition; and (d) Extruding the polyethylene composition as a coating onto a base layer including a substrate to form the multilayer structure, and The density is measured according to ASTM D792, the melt index is measured according to ASTM D1238 at 190°C and 2.16 kg, and the vinyl unsaturation is determined by… 1 H NMR confirmed that the double presaturation experiment was run with a modified pulse sequence, 100 scans, DS 4, AQ 1.64s, presaturation time D1 1s, and relaxation delay D13 13s, and the region between 4.95ppm and 5.15ppm was integrated.

9. The method of claim 8, wherein during the extrusion coating of the polyethylene composition as the coating, the coating has a necking of less than 10.16 cm at 134.11 m / min.

10. The method according to claim 8 or 9, wherein during the extrusion coating of the polyethylene composition as the coating, the coating has a necking of less than 8.89 cm at 268.22 m / min.

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