Lining for high temperature materials

Abstract

This invention provides a liner suitable for bulk containers. The liner can accommodate high-temperature materials (e.g., materials reaching temperatures above 120°C) and can include at least one sheet comprising polyethylene. The liner exhibits high dart impact resistance and provides a balance of stiffness, toughness, and sealing strength. According to embodiments disclosed herein, the at least one sheet of the liner includes a first layer, an adhesive layer, and a second layer, wherein the adhesive layer is disposed between the first and second layers. In another embodiment, the at least one sheet of the liner may include a second adhesive layer and a third layer, wherein the second adhesive layer is disposed between the first and third layers.

Description

Technical Field

[0001] The embodiments disclosed herein relate generally to linings suitable for bulk containers, and more specifically to linings capable of accommodating high-temperature materials. Background Technology

[0002] In flexible packaging applications, high-temperature materials such as bitumen are filled into the linings of bulk containers. The lining sheets accommodating these high-temperature materials require a good balance of stiffness and toughness. High-temperature materials (e.g., those reaching temperatures above 120°C) cannot be packaged in conventional polyethylene sheets because polyethylene typically has a melting point below 135°C or 120°C. Polypropylene-based sheets can have a high melting point to accommodate certain high-temperature materials, but they cannot withstand heavy loads due to poor sealing strength and dart impact resistance. Therefore, there is a need for lining sheets suitable for bulk containers that offer a good balance of performance, including high dart impact resistance, as well as stiffness, toughness, and sealing strength. Summary of the Invention

[0003] This invention provides a liner suitable for bulk containers and including at least one sidewall comprising at least one sheet, wherein the at least one sheet comprises a first layer, an adhesive layer, and a second layer. In some embodiments, the at least one sheet may further include a second adhesive layer and a third layer. This invention also provides a liner capable of accommodating high-temperature materials and may include sheets with high dart impact resistance and a balance of stiffness, toughness, and sealing strength.

[0004] This document discloses a liner. The liner includes at least one sidewall, the sidewall comprising at least one sheet, the at least one sheet comprising: a first layer comprising at least 70% by weight polyethylene based on the total weight of the first layer; an adhesive layer comprising at least 60% by weight a propylene-based elastomer based on the total weight of the adhesive layer, the propylene-based elastomer having a density in the range of 0.850 g / cc to 0.900 g / cc and a melt flow rate of 1 g / 10 min to 8 g / 10 min; and a second layer having a melting point greater than 140°C and comprising at least 50% by weight polypropylene based on the total weight of the second layer, the polypropylene having a density of 0.890 g / cc to 0.910 g / cc and a melt flow rate of 1 g / 10 min to 5 g / 10 min; and wherein the adhesive layer is disposed between the first layer and the second layer; and wherein the at least one sheet has an A-type dart impact strength greater than 5 g / μm.

[0005] These and other implementation schemes are described in more detail in the specific embodiments. Attached Figure Description

[0006] Figure 1 This is a diagram showing the heat seal strength of Embodiment 1 of the present invention. Detailed Implementation

[0007] The disclosed liner is described in more detail below. The liner is suitable for bulk containers and can have a variety of other applications, including, for example, bags, stand-up pouches, bulk bags, pre-packaged goods, pouches, etc. However, this disclosure should not be construed as limiting the embodiments set forth below, as this disclosure is an illustrative description of the embodiments described herein.

[0008] 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.

[0009] 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). These polyethylene materials are generally known in the art.

[0010] As used herein, the term "polypropylene" refers to a polymer containing more than 50% by weight of polymerizable propylene monomers (based on the total amount of polymerizable monomers) and optionally may contain at least one comonomer.

[0011] As used herein, the term "sidewall" refers to a piece of polymer film that is sealed to itself or another sidewall by means of, for example, welding or adhesive to form a lining or bag.

[0012] As used herein, the term "sheet" refers to a portion of the sidewall of a polymer film. A single-wound polymer film provides one sheet, while a double-wound polymer film provides two sheets. Sheets can be extruded blown films.

[0013] As used herein, the term "adhesive layer" refers to a layer of film or sheet placed on one or more layers to facilitate adhesion of that layer to another surface or layer.

[0014] 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 otherwise, 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.

[0015] The lining disclosed herein includes at least one sidewall. The sidewall may be sealed to itself or to another sidewall to form the lining. The lining and sidewall each include at least one sheet, said at least one sheet comprising a first layer, an adhesive layer, and a second layer. According to the embodiments disclosed herein, the lining may include one, two, three, four, five, six, or more sheets.

[0016] The first layer comprises at least 70% by weight of polyethylene based on the total weight of the first layer. This document discloses and includes all individual values ​​and sub-ranges of at least 70% by weight. For example, in embodiments, the first layer may comprise at least 70%, at least 80%, at least 90%, at least 95%, at least 99%, or at least 99.9% by weight of polyethylene based on the total weight of the first layer. In other embodiments, the first layer may comprise from 70% to 100% by weight, or from 80% to 100% by weight, or from 90% to 100% by weight of polyethylene based on the total weight of the first layer.

[0017] In implementations, based on the total weight of the at least one sheet, the first layer comprises more than 30% by weight of the at least one sheet. This document discloses and includes all individual values ​​and subranges greater than 30% by weight. For example, in some implementations, the first layer may comprise more than 30%, more than 40%, more than 50%, or more than 60% by weight of the at least one sheet.

[0018] In this embodiment, the polyethylene of the first layer has a density of less than 0.920 g / cc. This document discloses and includes all individual values ​​and sub-ranges of a density less than 0.920 g / cc. For example, in this embodiment, the polyethylene of the first layer may have a density of less than 0.920 g / cc, less than 0.918 g / cc, less than 0.916 g / cc, or less than 0.914 g / cc.

[0019] In some embodiments, the polyethylene of the first layer has a melt index (I2) of less than 2.0 g / 10 min. This document discloses and includes all individual values ​​and sub-ranges of a melt index (I2) of less than 2.0 g / 10 min. For example, the polyethylene of the first layer may have a melt index (I2) of less than 2.0 g / 10 min, less than 1.8 g / 10 min, less than 1.6 g / 10 min, less than 1.4 g / 10 min, less than 1.2 g / 10 min, less than 1.0 g / 10 min, or less than 0.9 g / 10 min.

[0020] Examples of commercially available polyethylene that can be used in some implementation schemes include INNATE, which is available from The Dow Chemical Company, Midland, MI. TM TH60.

[0021] The at least one sheet includes an adhesive layer. The adhesive layer is disposed between the first layer and the second layer. The adhesive layer can adhere the first layer to the second layer.

[0022] The adhesive layer comprises at least 60 wt% of a propylene-based elastomer based on the total weight of the adhesive layer, the propylene-based elastomer having a density in the range of 0.850 g / cc to 0.900 g / cc and a melt flow rate in the range of 1 g / 10 min to 8 g / 10 min. All individual values ​​and sub-ranges of at least 60 wt% are disclosed and included herein. For example, in embodiments, the adhesive layer may comprise at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, at least 99 wt%, or at least 99.9 wt% of a propylene-based elastomer based on the total weight of the adhesive layer. In other embodiments, the adhesive layer may comprise 60 wt% to 100 wt%, 70 wt% to 100 wt%, 80 wt% to 100 wt%, or 90 wt% to 100 wt% of a propylene-based elastomer based on the total weight of the adhesive layer.

[0023] The acrylic elastomer of the adhesive layer has a density in the range of 0.850 g / cc to 0.900 g / cc. This document discloses and includes all individual values ​​and sub-ranges of 0.850 g / cc to 0.900 g / cc. For example, in embodiments, the acrylic elastomer may have a density in the range of 0.850 g / cc to 0.890 g / cc, 0.855 g / cc to 0.890 g / cc, 0.860 g / cc to 0.890 g / cc, 0.865 g / cc to 0.890 g / cc, 0.855 g / cc to 0.900 g / cc, 0.860 g / cc to 0.900 g / cc, or 0.865 g / cc to 0.900 g / cc.

[0024] The propylene-based elastomer of the binder layer has a melt flow rate of 1 g / 10 min to 8 g / 10 min. This document discloses and includes all individual values ​​and sub-ranges from 1 g / 10 min to 8 g / 10 min. For example, the propylene-based elastomer of the binder layer may have a melt flow rate of 1 g / 10 min to 8 g / 10 min, 1 g / 10 min to 7 g / 10 min, 1 g / 10 min to 6 g / 10 min, 1 g / 10 min to 5 g / 10 min, 1 g / 10 min to 4 g / 10 min, or 1 g / 10 min to 3 g / 10 min.

[0025] Examples of commercially available propylene-based elastomers that can be used in some implementations include VERSIFY, available from Dow Chemical Company in Midland, Michigan. TM 2300 and Versify TM 2000.

[0026] The at least one sheet includes a second layer. In one embodiment, the second layer forms the inner surface of the enclosed lining that is exposed to high-temperature material. In another embodiment, the second layer has a melting point greater than 140°C and comprises at least 50% by weight of polypropylene with a density of 0.890 g / cc to 0.910 g / cc and a melt flow rate of 1 g / 10 min to 5 g / 10 min, based on the total weight of the second layer.

[0027] The second layer of polypropylene has a density of 0.890 g / cc to 0.910 g / cc. This document includes and discloses all individual values ​​and sub-ranges of 0.890 g / cc to 0.910 g / cc. For example, the second layer of polypropylene may have a density of 0.890 g / cc to 0.910 g / cc, 0.895 g / cc to 0.910 g / cc, 0.900 g / cc to 0.910 g / cc, 0.890 g / cc to 0.905 g / cc, 0.895 g / cc to 0.905 g / cc, or 0.900 g / cc to 0.905 g / cc.

[0028] The second layer of polypropylene has a melt flow rate of 1 g / 10 min to 5 g / 10 min. This document includes and discloses all individual values ​​and sub-ranges of 1 g / 10 min to 5 g / 10 min. For example, the second layer of polypropylene may have a melt flow rate of 1 g / 10 min to 5 g / 10 min, 1 g / 10 min to 4 g / 10 min, or 2 g / 10 min to 4 g / 10 min.

[0029] In the implementation scheme, the second layer of polypropylene is homopolymer polypropylene.

[0030] In some embodiments, the second layer further comprises a propylene / ethylene copolymer. In embodiments where the propylene / ethylene copolymer is present in the second layer, the second layer may comprise up to 50% by weight of the propylene / ethylene copolymer based on the total weight of the second layer. All individual values ​​and subranges of up to 50% by weight are disclosed and included herein. For example, in some embodiments, the second layer may comprise up to 50% by weight, up to 40% by weight, up to 30% by weight, or up to 25% by weight of the propylene / ethylene copolymer.

[0031] In embodiments where a propylene / ethylene copolymer is present in the second layer, the propylene / ethylene copolymer may have a density in the range of 0.890 g / cc to 0.910 g / cc. This document includes and discloses all individual values ​​and sub-ranges of 0.890 g / cc to 0.910 g / cc. For example, the propylene / ethylene copolymer in the second layer may have densities of 0.890 g / cc to 0.910 g / cc, 0.895 g / cc to 0.910 g / cc, 0.900 g / cc to 0.910 g / cc, 0.890 g / cc to 0.905 g / cc, 0.895 g / cc to 0.905 g / cc, or 0.900 g / cc to 0.905 g / cc.

[0032] In some embodiments, the at least one sheet further includes a second adhesive layer and a third layer. In such embodiments, the second adhesive layer is disposed between the first and third layers of the at least one sheet. The second adhesive layer can adhere the first layer to the third layer. In some embodiments, the second adhesive layer may have the same composition as the adhesive layer disposed between the first and second layers. In other embodiments, the second adhesive layer may have a different composition than the adhesive layer.

[0033] In one embodiment, the second adhesive layer comprises at least 60 wt% of a second propylene-based elastomer based on the total weight of the second adhesive layer, the second propylene-based elastomer having a density in the range of 0.850 g / cc to 0.900 g / cc and a melt flow rate in the range of 1 g / 10 min to 8 g / 10 min. All individual values ​​and subranges of at least 60 wt% are disclosed and included herein. For example, in one embodiment, the second adhesive layer may comprise at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, at least 99 wt%, or at least 99.9 wt% of a second propylene-based elastomer based on the total weight of the second adhesive layer. In other embodiments, the second adhesive layer may comprise 60 wt% to 100 wt%, 70 wt% to 100 wt%, 80 wt% to 100 wt%, or 90 wt% to 100 wt% of a second propylene-based elastomer based on the total weight of the second adhesive layer.

[0034] In embodiments, the second propylene-based elastomer has a density in the range of 0.850 g / cc to 0.900 g / cc. All individual values ​​and sub-ranges of 0.850 g / cc to 0.900 g / cc are disclosed and included herein. For example, in embodiments, the second propylene-based elastomer may have a density in the range of 0.850 g / cc to 0.890 g / cc, 0.855 g / cc to 0.890 g / cc, 0.860 g / cc to 0.890 g / cc, 0.865 g / cc to 0.890 g / cc, 0.855 g / cc to 0.900 g / cc, 0.860 g / cc to 0.900 g / cc, or 0.865 g / cc to 0.900 g / cc.

[0035] In an embodiment, the second propylene-based elastomer has a melt flow rate of 1 g / 10 min to 8 g / 10 min. All individual values ​​and sub-ranges of 1 g / 10 min to 8 g / 10 min are disclosed and included herein. For example, the second propylene-based elastomer may have a melt flow rate of 1 g / 10 min to 8 g / 10 min, 1 g / 10 min to 7 g / 10 min, 1 g / 10 min to 6 g / 10 min, 1 g / 10 min to 5 g / 10 min, 1 g / 10 min to 4 g / 10 min, or 1 g / 10 min to 3 g / 10 min.

[0036] In embodiments where the at least one laminate further comprises a second adhesive layer and a third layer, the third layer may have the same composition as or a different composition from the second layer of the at least one laminate. In one embodiment, the third layer has a melting point greater than 140°C and comprises at least 50% by weight of a second polypropylene having a density of 0.890 g / cc to 0.910 g / cc and a melt flow rate of 1 g / 10 min to 5 g / 10 min, based on the total weight of the third layer.

[0037] In embodiments, the third layer comprises at least 50 wt% of a second polypropylene based on the total weight of the third layer. All individual values ​​and subranges of at least 50 wt% are disclosed and included herein. For example, in embodiments, the third layer may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, at least 99 wt%, or at least 99.9 wt% of a second polypropylene based on the total weight of the third layer. In other embodiments, the third layer may comprise 50 wt% to 100 wt%, 60 wt% to 100 wt%, 70 wt% to 100 wt%, 80 wt% to 100 wt%, or 90 wt% to 100 wt% of a second polypropylene based on the total weight of the third layer.

[0038] In the embodiments, the second polypropylene has a density of 0.890 g / cc to 0.910 g / cc. This document includes and discloses all individual values ​​and sub-ranges of 0.890 g / cc to 0.910 g / cc. For example, the second polypropylene may have densities of 0.890 g / cc to 0.910 g / cc, 0.895 g / cc to 0.910 g / cc, 0.900 g / cc to 0.910 g / cc, 0.890 g / cc to 0.905 g / cc, 0.895 g / cc to 0.905 g / cc, or 0.900 g / cc to 0.905 g / cc.

[0039] In the embodiments, the second polypropylene has a melt flow rate of 1 g / 10 min to 5 g / 10 min. This document includes and discloses all individual values ​​and sub-ranges of 1 g / 10 min to 5 g / 10 min. For example, the second polypropylene may have a melt flow rate of 1 g / 10 min to 5 g / 10 min, 1 g / 10 min to 4 g / 10 min, or 2 g / 10 min to 4 g / 10 min.

[0040] In the implementation scheme, the second polypropylene is homopolymer polypropylene.

[0041] additive

[0042] It should be understood that any of the aforementioned layers of the at least one sheet may further include one or more additives known to those skilled in the art, such as antioxidants, UV stabilizers, heat stabilizers, slip agents, anti-blocking agents, antistatic agents, pigments or colorants, processing aids, crosslinking catalysts, flame retardants, fillers, and foaming agents.

[0043] The at least one sheet disclosed herein can have various thicknesses, depending on, for example, the number of layers. For example, in an embodiment, the at least one sheet can have a thickness of 10 micrometers to 200 micrometers, or alternatively 50 micrometers to 150 micrometers.

[0044] The at least one layer may have several desired properties. For example, in one embodiment, the at least one layer has a dart impact A greater than 5 g / μm, wherein the dart impact A is measured according to ASTM D1709. This document discloses and includes all individual values ​​and sub-ranges of the dart impact A greater than 5 g / μm. For example, the at least one layer may have a dart impact A greater than 5 g / μm, greater than 7 g / μm, greater than 9 g / μm, greater than 11 g / μm, or greater than 13 g / μm, wherein the dart impact A is measured according to ASTM D1709.

[0045] In an embodiment, the at least one sheet has a plateauseal strength greater than 35 N / 25 mm, wherein the plateauseal strength can be measured according to the test methods described below. This document discloses and includes all individual values ​​and sub-ranges of plateauseal strength greater than 35 N / 25 mm. For example, the at least one sheet may have a plateauseal strength greater than 35 N / 25 mm, greater than 36 N / 25 mm, greater than 37 N / 25 mm, or greater than 38 N / 25 mm, wherein the plateauseal strength can be measured according to the test methods described below.

[0046] In an embodiment, the at least one layer has a 2% secant modulus greater than 250 MPa in the longitudinal or transverse direction, wherein the 2% secant modulus can be measured according to ASTM D882. This document discloses and includes all individual values ​​and subranges of the 2% second modulus greater than 250 MPa in the longitudinal or transverse direction. For example, the at least one layer may have a 2% secant modulus greater than 250 MPa, greater than 260 MPa, greater than 270 MPa, greater than 280 MPa, or greater than 290 MPa, wherein the 2% secant modulus can be measured according to ASTM D882.

[0047] Products

[0048] Embodiments of the present invention also provide articles formed from the linings described herein. Examples of such articles may include bulk containers, packages, flexible packaging, bags, and pouches. In some embodiments, the bags may contain liquids, powders, food, or other articles. In view of the teachings herein, articles and packages can be formed from the linings disclosed herein using techniques known to those skilled in the art.

[0049] Test methods

[0050] density

[0051] Density is measured according to ASTM D792 and is expressed in grams per cubic centimeter (g / cc).

[0052] Melt index (I2)

[0053] Melt index (I2) was measured at 190°C and 2.16 kg according to ASTM D1238. Values ​​are reported in g / 10 min, corresponding to the number of grams eluted per 10 min.

[0054] melt flow rate

[0055] Melt flow rate was measured according to ASTM D1238 at 230°C / 2.16 kg and reported in grams eluted per 10 minutes.

[0056] Tensile strength

[0057] Tensile strength was measured according to ASMT D882. Tensile strength is reported in megapascals (MPa).

[0058] Elmendorf rip

[0059] Elmendorf tear (also referred to as tear resistance in this document) is measured according to ASTM D1922.

[0060] Puncture energy and force

[0061] Puncture energy and force were measured according to ASTM D 5748-95 with the following modifications: the membrane sample was cut into a test area with a diameter of 120 mm; the probe was made of stainless steel with a diameter of 12.7 mm; and the test temperature was room temperature. Puncture energy is reported in joules (J). Puncture force is reported in newtons (N).

[0062] secant modulus

[0063] The secant modulus is measured according to ASTM D882.

[0064] Dart Impact

[0065] Type A dart impact is measured according to ASTM 1709A. Type A dart impact is reported in grams (g) and grams per micrometer (g / μm), where g / μm is the normalized value of Type A dart impact per unit sample thickness (in micrometers).

[0066] Heat sealing strength

[0067] Heat seal measurements were performed on a commercial tensile testing machine according to ASTM F-88 (Technical A). The heat seal test is a measure of the strength of the seal (seal strength) in a flexible barrier material. This is done by measuring the force required to separate a test strip containing the seal and identifying the failure mode of the sample. Seal strength is related to opening force and packaging integrity. Before cutting, the film was conditioned at 23°C (±2°C) and 50% (±5%) RH for at least 40 hours according to ASTM D-618 (Procedure A). Strips approximately 10 cm in length and 25 mm in width were then cut longitudinally from the film. The longitudinally heat-sealed strips were then measured on a J&B Hot Tack 4000 tester under the following conditions within a temperature range: seal pressure = 0.275 N / mm². 2 Sealing time = 0.5 seconds.

[0068] The heat-sealed samples were conditioned for 24 hours, then measured using an INSTRON 5965 tensile tester equipped with a 200N pressure sensor at a tensile speed of 500 mm / min. The strips were tested without support. Sealing strength values ​​are reported in N / 25 mm. Six repeated tests were performed for each sealing temperature. The plateau sealing strength is reported as the peak or highest sealing strength value on the heat-sealing curve of sealing strength versus temperature (in degrees Celsius). See example Figure 1 It provides the heat sealing curve of the following embodiment 1 of the present invention.

[0069] Example

[0070] The following examples illustrate the features of this disclosure, but are not intended to limit the scope of this disclosure.

[0071] Polymer / film used

[0072] The following materials are included in the embodiments discussed below.

[0073] INNATE TM TH 60 is a polyethylene resin with a density of 0.912 g / cc and a melt index (I2) of 0.85 g / 10 min, and is commercially available from Dow Chemical Company in Midland, Michigan.

[0074] INTUNE TM 5535.00, a crystalline block copolymer having a density of 0.904 g / cc and a melt flow rate of 6.5 g / 10 min and commercially available from Dow Chemical Company, Midland, Michigan.

[0075] INTUNE TM 5545.00, a crystalline block copolymer having a density of 0.904 g / cc and a melt flow rate of 9.5 g / 10 min and commercially available from Dow Chemical Company, Midland, Michigan.

[0076] VERSIFY TM 2300, a polypropylene-based elastomer with a density of 0.867 g / cc and a melt flow rate of 2.0 g / 10 min, and commercially available from Dow Chemical Company, Midland, Michigan.

[0077] VERSIFY TM 2000, a polypropylene-based elastomer having a density of 0.888 g / cc and a melt flow rate of 2.0 g / 10 min and commercially available from Dow Chemical Company, Midland, Michigan.

[0078] FINA 3365 is a polypropylene homopolymer with a density of 0.905 g / cc, a melt flow rate of 3.8 g / 10 min, and a melting point of 165 °C, and is commercially available from Total SA (Paris, France).

[0079] Sanren F800E is a polypropylene / ethylene copolymer with a density of 0.905 g / cc, a melt flow rate of 8.0 g / 10 min, and a melting point of 140 °C, and is commercially available from Sinopec (Beijing, China).

[0080] PPH-T03(T30S) is a propylene homopolymer with a density of 0.905 g / cc, a melt flow rate of 3.2 g / 10 min, and a melting point of 164 °C, which is commercially available from Sinopec Corporation in Beijing, China.

[0081] To manufacture three- and five-layer sheets.

[0082] A five-layer sheet is manufactured on a 7-layer blown film extruder with the following parameters: D = 30 mm, L / D = 30, maximum speed 100 rpm, maximum pressure: 50 MPa; maximum output: 35 kg / h; maximum traction speed: 45 m / min; 7-layer flat die; diameter: 120 mm, die lip clearance: 1.5 mm and 2.2 mm; maximum flat width: 500 mm; maximum BUR: 2.65; and cooling: 2.2 kW blower. The layer ratio of the film extruder is adjusted so that each film manufactured by the 7-layer blown film extruder has 5 layers.

[0083] Three-layer sheets are manufactured on a 3-layer blown film machine with the following parameters: screw: 1.25 inches, L / D = 28; die head: 3 inches (spiral); cooling: double-lip air ring; rated output: 30 kg / h to 45 kg / h; thickness range: 35 μm to 135 μm; flatness: 175 mm to 350 mm; and BUR range: 1.5 to 3.0:1.

[0084] Table 1 below provides the construction, layer ratio, and thickness of the comparative embodiment (CE) and the embodiment of the present invention (IE) with a five-layer structure. Table 2 below provides the construction, layer ratio, and thickness of the embodiment with a three-layer structure. In the five-layer structures (A / B / C / D / E) CE 2 and IE 1, layers B and D act as the first and second adhesive layers, and in the three-layer structure (A / B / C), layer B acts as the adhesive layer. Layer A in the three-layer structure and layers A and E in the five-layer structure have melting points greater than 140°C.

[0085] Table 1: Construction of the Five-Layer Implementation

[0086]

[0087] Table 2: Construction of the Three-Layer Implementation

[0088]

[0089]

[0090] The performance characteristics of the comparative embodiments and embodiments of the present invention were measured according to the test methods described above. Table 3 below provides the results for the five-layer embodiments CE 1-2 and IE 1. It can be seen that, compared with CE 1 and 2, IE 1 has a surprisingly and significantly higher A-type dart impact rating. IE 1 also has a good balance of performance, such as toughness and stiffness.

[0091] Table 4 below provides the results for the three-layer embodiments CE 3-6 and IE 2-3. It can be seen that IE 2-3 exhibits a surprisingly high A-type dart impact rating compared to CE 3-6. IE 2-3 also demonstrates a good balance of performance characteristics, such as toughness and stiffness.

[0092] Table 3: Performance of CE 1-2 and IE 1

[0093] unit CE 1 CE 2 IE 1 thickness μm 100 70 90 Dart impact, Type A g 102.5 135 531 Dart impact, Type A g / μm 1.03 1.93 5.90 Tear resistance, MD g 114 98 287 Tear resistance, TD g 236 135 810 Tensile strength, MD MPa 29.15 44.91 46.72 Tensile strength, TD MPa 29.06 24.88 45.27 Elongation, MD ％ 740 930 929 Elongation, TD ％ 659 670 985 Puncture energy J 4.51 2.66 3.63 Penetration force N 114.76 74.14 83.45 2% secant modulus, MD MPa 796 757 515 2% secant modulus, TD MPa 801 739 512

[0094] Table 4: Performance of CE 3-6 and IE 2-3

[0095]

[0096]

[0097] In addition to the performance characteristics described above, the sealing strength of the embodiments was also tested. Some comparative embodiments exhibited delamination during the peeling process of the sealing strength test. Table 5 below provides the sealing strength results for IE 1-3. Figure 1 The sealing strength curves for IE 1 are provided. It can be seen that IE 1 has a stable sealing strength greater than 40 N / 25 mm; IE 2 has a stable sealing strength greater than 35 N / 25 mm; and IE 3 has a stable sealing strength greater than 40 N / 25 mm.

[0098] Table 5: IE Sealing strength 1-3

[0099]

[0100] IE 1 was formed into a liner suitable for bulk containers, including at least one sidewall, and a hot-fill test was performed, in which the liner was filled with hot silicone oil at a temperature of 130°C. No deformation or leakage was observed when the hot silicone oil was added to the liner.

[0101] Unless expressly excluded or otherwise limited, every document cited herein (if any), including any cross-referenced or related patent or application and any patent application or patent claiming priority or benefit to this application, is hereby incorporated in its entirety by reference. No reference to any document acknowledges it as prior art to any invention disclosed or claimed herein, or as teaching, indicating, or disclosing any such invention, alone or in combination with any other referenced document. Furthermore, in the event of any conflict between the meaning or definition of any term in this document and the meaning or definition of the same term in any document incorporated by reference, the meaning or definition given to the term in this document shall prevail.

[0102] While specific embodiments of the invention have been described and illustrated, it will be apparent to those skilled in the art that many other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, it is intended that all such changes and modifications falling within the scope of the invention be covered in the appended claims.

Claims

1. A liner suitable for bulk containers, the liner comprising: At least one sidewall comprising at least one layer, said at least one layer comprising: The first layer comprises at least 70% by weight of polyethylene based on the total weight of the first layer, the polyethylene having a density of less than 0.920 g / cc and a melt index I2 of less than 2.0 g / 10 min; An adhesive layer comprising at least 60% by weight of a propylene-based elastomer based on the total weight of the adhesive layer, the propylene-based elastomer having a density in the range of 0.850 g / cc to 0.900 g / cc and a melt flow rate in the range of 1 g / 10 min to 8 g / 10 min; and The second layer has a melting point greater than 140°C and comprises at least 50% by weight of homopolymer polypropylene based on the total weight of the second layer, the homopolymer polypropylene having a density of 0.890 g / cc to 0.910 g / cc and a melt flow rate of 1 g / 10 min to 5 g / 10 min; and The adhesive layer is disposed between the first layer and the second layer; and The at least one layer has an A-type dart impact of greater than 5 g / μm and the second layer forms the inner surface of the lining.

2. The lining according to claim 1, wherein the at least one layer further comprises: The second adhesive layer comprises at least 60% by weight of a second propylene-based elastomer based on the total weight of the second adhesive layer, the second propylene-based elastomer having a density in the range of 0.850 g / cc to 0.900 g / cc and a melt flow rate in the range of 1 g / 10 min to 8 g / 10 min. and The third layer has a melting point greater than 140°C and contains at least 50% by weight of a second polypropylene based on the total weight of the third layer, the second polypropylene having a density of 0.890 g / cc to 0.910 g / cc and a melt flow rate of 1 g / 10 min to 5 g / 10 min. The second adhesive layer is disposed between the first layer and the third layer.

3. The lining according to claim 1 or claim 2, wherein the first layer comprises more than 30% by weight of the at least one sheet.

4. The lining according to claim 1 or claim 2, wherein the at least one layer has a stable sealing strength greater than 35 N / 25 mm.

5. The lining according to claim 1 or claim 2, wherein the at least one layer has a secant modulus of more than 250 MPa in the longitudinal or transverse direction.

6. The lining according to claim 1 or claim 2, wherein the melting point of the second layer is greater than or equal to 164°C.

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