TPE-based linings for pressurized vessels

Abstract

Use of a closure liner composition for a container used in a pressurized dispensing system, the composition comprising a blend of a thermoplastic elastomer (TPE) and UHMW-PE.

Description

Technical Field

[0001] The present invention relates generally to improved liner compositions for closures, and more particularly to thermoplastic elastomer liner compositions that provide an effective barrier to oxygen ingress. The liner compositions are highly effective in preventing oxygen ingress into containers, such as those used in pressurized dispensing systems, particularly bag-in-containers (BICs) or bag-in-bottles, bag-in-boxes, or bottles-in-bottles (BIBs), and are advantageously characterized by improved physical properties, such as tensile strain at yield and tensile stress at yield. The present invention also relates to a method of making such a liner from such a liner composition, and a method of making a closure for a beverage product container. Background Art

[0002] Closures for beverage containers include a closure shell formed of metal, plastic, or both, and are typically provided with a liner on the inner surface of the closure shell end plate. In addition to the oxygen barrier function, the liner is also intended to provide a sealing function between the closure member and the container opening.

[0003] Despite the closure with a liner, oxygen can penetrate the closure housing or enter through the space between the closure housing and the container. Oxygen can adversely affect the beverage product stored in the container because a small amount of oxygen can change the taste of the beverage product or cause the product to spoil. Therefore, it is also desirable that the liner is made of or includes a material that prevents oxygen from entering. Efforts to provide a liner that effectively prevents oxidation of beverages stored in containers have been described in the prior art. Various techniques have been used to prepare liner compositions that prevent oxygen from entering. In one technique, the liner composition includes an oxygen scavenger blended into a base polymer composition, and the liner composition can be molded into the form of a closure liner. For this type of closure liner, the oxygen scavenger will reduce the amount of residual oxygen in the container head space during filling, and consume any external oxygen that permeates through the closure. Another method to prevent oxygen from entering is to use a liner composition as an oxygen barrier layer (i.e., the liner is a physical barrier layer that prevents oxygen from entering). This liner composition includes an oxygen barrier in a base polymer composition, and the liner composition can be molded into the form of a closure liner. While this type of liner can reduce the ingress of external oxygen into the container, it does not reduce the amount of oxygen in the container headspace.Another method of preventing oxygen ingress is to utilize a closure liner that has both an oxygen scavenger and an oxygen barrier.

[0004] An example of a closure with an oxygen absorbing liner is described in EP2467420. The liner described therein is made of a TPE resin blended with an antioxidant or an oxygen absorber. The oxygen absorbing layer can be made of a thermoplastic elastomer in which an oxygen absorber is mixed. Other examples are EP-A-2509883 and EP-A-2820101. Although the above-mentioned liner or seal can effectively limit the amount of oxygen entering the container, it is desirable to further improve in the field of oxygen barrier liner for closures. In addition, due to the versatility of the liner composition, particularly for pressure dispensing systems, such as bottles in bottle closures, the liner composition needs to have specific materials and physical properties in terms of the function of the liner with a safety function. These properties include high tensile strength, low compression set and low yield tensile strain, low hardness and low density, while having high MFI. In addition, the liner should also be made of a composition that is easy to process, and can be produced by known techniques such as injection molding and cold stamping molding, and can be easily incorporated into the closure in other ways.

[0005] The liner compositions of the present invention and the liners made from such compositions solve at least all of the above-mentioned objects. The liner compositions according to the present invention do provide particularly desirable properties for containers, such as those in pressurized dispensing systems, in which liquids or other fluid materials are discharged from a source container by displacement with a pressurized medium (e.g., air or liquid), and provide related aspects related to the manufacture, operation process, and deployment of such systems. In the case where a liner-based container is used for a pressure dispensing operation, the pressurized gas itself (e.g., air or nitrogen) can permeate through the liner material and dissolve in the liquid in the liner. When the liquid is subsequently dispensed, the pressure drop in the distribution line and downstream instruments and equipment may result in the release of previously dissolved gas, resulting in the formation of bubbles in the dispensed liquid stream, thereby having an adverse effect. Pressurized containers are known in the art. Depending on the geometry of the outer container, bag-in-bottle containers are also referred to as bag-in-bottle or bag-in-box, all of which are considered herein to be included within the meaning of the term bag-in-bottle container as a series of liquid dispensing containers consisting of an outer container comprising an opening (mouth) to the atmosphere, and comprising a collapsible inner bag joined to said container and vented to the atmosphere in the region of said mouth. The dispensing system must include at least one vent hole that connects the atmospheric fluid to the region between the inner bag and the outer container in order to control the pressure in said region to squeeze the inner bag and thus dispense the liquid contained therein.

[0006] A preferred container according to the present invention is an "integrated blow-molded bag-in-container" assembled into a container by blow-molding a polymer multilayer preform into a container comprising an inner layer and an outer layer, so that the adhesion between the inner layer and the outer layer of the resulting container is weak enough to easily delaminate when a gas is introduced at the interface. The "inner layer" and the "outer layer" may each consist of a single layer or multiple layers. Highly preferred pressurized containers are those described as bag-in-containers (BICs) and / or bottles-in-bottles (BIBs) described in EP2148770, EP2146832, and EP2152486.

[0007] Pressurized dispensing systems are known in the art. In order to dispense the fluid contained in the inner bag, the inner bag container is mounted on a dispensing device. In its mounted position, a dispensing conduit leading to the atmosphere is in fluid communication with the interior of the inner bag through the mouth of the inner bag container, while a pressurized gas source is in fluid communication with the space through a vent in cooperation with the closure device. The pressurized gas source can be a cartridge of pressurized or liquefied gas (e.g., CO2 or N2), or it can be a pump or a compressor.

[0008] The liner composition required for the container requires high yield tensile stress, low compression set, low yield tensile strain, low tear strength, low hardness, low density and excellent MFI, while having a high oxygen absorption rate. According to the present invention, a new liner composition based on TPE and SS / SMBS and UHMW-PE has been identified, which exhibits the properties defined above.

[0009] As used herein, the terms "liner," "sealing composition," and the like are broad terms and are used in their ordinary sense and refer to, but are not limited to, materials that prevent the ingress of oxygen when used in the preferred methods and processes. Summary of the invention

[0010] The present invention has several different aspects. In one aspect, the present invention relates to the use of a liner composition comprising a blend of a thermoplastic elastomer and UHMW-PE for a pressurized vessel.

[0011] Compositions of the above type exhibit excellent properties as described above and are therefore useful as keg seals and / or crown liners and / or can liners, plastic closure liners for beverage containers and seals for pressure dispensing systems, in particular for bag-in-containers (BIC) and bottle-in-bottle (BIB) containers.

[0012] The liner may be formed to adhere to the inwardly facing surface of the closure, ie to function as a seal, or to act as a closure itself. DETAILED DESCRIPTION

[0013] The plastic composition of the present invention will be described below in the context of its preferred use, i.e. as a liner composition for a pressurized container. However, it should be understood that the liner composition of the present invention is not limited to this use. The plastic composition of the present invention can be used in any other application where, for example, a material having oxygen barrier properties is desired, and / or where a material exhibiting excellent physical properties is desired.

[0014] The composition is readily processable by known processing and compounding methods and can be molded into liners of the type described above.

[0015] TPE:

[0016] Thermoplastic elastomers are polymers or blends of polymers that can be processed and recycled in the same manner as conventional thermoplastic materials, but also have rubber-like qualities and rubber-like properties. Thermoplastic elastomers can be obtained by combining a thermoplastic polyolefin with an elastomeric composition in such a way that the elastomer is intimately and uniformly dispersed as a particulate phase within a continuous phase of the thermoplastic polyolefin.

[0017] TPE suitable for the present invention includes:

[0018] (i) Styrene block copolymers (TPE-S) are based on two-phase block copolymers with hard segments and soft segments. The styrene end blocks provide thermoplastic properties and the butadiene midblock provides elastomeric properties. SBS becomes SEBS upon hydrogenation because the elimination of the C=C bonds in the butadiene component produces an ethylene and butene midblock, hence the SEBS acronym. and The product is an example of a hydrogenated styrene block copolymer.

[0019] (ii) Thermoplastic Polyolefins (TPE-O or TPO). These materials are blends of polypropylene (PP) and uncrosslinked EPDM rubber. Apex is an example of this type of TPE-O.

[0020] (iii) Thermoplastic vulcanizates (TPE-V or TPV). These materials are compounds of PP and EPDM rubber, which however have been dynamically vulcanized during the compounding step.

[0021] (iv) Thermoplastic polyurethanes (TPE-U or TPU). These materials can be based on polyester or polyether polyurethane.

[0022] (v) Thermoplastic copolyester (TPE-E or COPE or TEEE).

[0023] (vi) Melt processable rubber (MPR).

[0024] (vii) Thermoplastic polyether block amide (TPE-A).

[0025] Examples of thermoplastic elastomers that can be included in the plastic composition of the present invention are, for example, thermoplastic polyolefin homopolymers or copolymers blended with olefin rubbers that are fully crosslinked, partially crosslinked, or not crosslinked at all. In a preferred embodiment, the thermoplastic elastomer composition can be a resin polymer of propylene of the type described in U.S. Patent No. 5,843,577 and a butyl crosslinked rubber. As further described in U.S. Patent No. 5,843,577, the thermoplastic elastomer can include other additives, including lubricants (such as polyamides and other additives). Lubricants are usually added to soften the material and help process certain viscous materials. Lubricants can also improve the torque removal properties of the lining made of the composition.

[0026] Examples of suitable thermoplastic elastomers are those marketed by Advanced Elastomer Systems under the product names Thermoplastic elastomers sold. In U.S. Patent 6,062,269, A thermoplastic resin generally described as a composite of polypropylene and isobutylene-isoprene rubber.

[0027] In a preferred embodiment, the thermoplastic elastomer composition may include an ethylene-propylene copolymer and a crosslinkable rubber and / or may include a terpolymer of ethylene, propylene and a diene. Examples of such thermoplastic elastomers include commercially available Includes ethylene, propylene and diene terpolymers. ELASTOMER(R) and other thermoplastic elastomers similar thereto are available from Advanced Elastomer Systems, Inc. of Akron, Ohio.

[0028] The thermoplastic elastomer used in the composition of the present invention may also be a blend of one or more thermoplastic elastomers.

[0029] Highly preferred thermoplastic elastomers (TPE) according to the present invention may be selected from the group comprising styrene-based TPEs (STPEs).

[0030] Preferred examples of the random copolymer or block copolymer of styrene with butadiene or isoprene include styrene butadiene rubber (SBR), styrene butadiene styrene (SBS), styrene isoprene styrene (SIS), hydrogenated SBS (SEBS), and hydrogenated SIS.

[0031] Styrene-based thermoplastic elastomers are polymers consisting of polymer chains with a polydiene central block and polystyrene end blocks (also called SBD, styrene block copolymers). The diene blocks give the polymer its elastomeric properties, while the polystyrene blocks constitute the thermoplastic phase. Preferably, the polydiene blocks consist of butadiene units, so that the resulting TPE is an SBS (styrene-butadiene-styrene polymer).

[0032] Since the backbone of SBS contains unsaturated groups that are sensitive to oxidation, styrene-based TPEs are preferably hydrogenated polymers, i.e. polymers in which at least part of the aliphatic unsaturated groups have been hydrogenated. Such products are also referred to as SEBS polymers (styrene-ethylene / butylene-styrene). In the case mentioned above where styrene and / or butadiene are present in STPEs, it is considered that similar results are obtained with polymers comprising polyisoprene blocks (SIS: styrene-isoprene-styrene) or based on substituted styrenes (e.g. α-methylstyrene), which is intended to illustrate but not to limit the term "STPE". STPE applicable according to the present invention may also be a blend of polyolefins and SBC.

[0033] Highly preferred are saturated ABA-type thermoplastic elastomer block copolymers based on styrene and butadiene units. For example, block copolymers of the styrene-ethylene butylene-styrene (SEBS) type can be used. Such copolymers are marketed under the trade name Kraton- (eg, Kraton-G1652 and Kraton-G2705) are sold and available from Shell Chemical Company.

[0034] Preferred TPEs include custom SBS grades sold by Hexpol. Those TPEs under the series.

[0035] UHMW-PE:

[0036] The liner composition according to the present invention comprises ultra high molecular weight polyethylene. UHMW-PE is an extremely high viscosity polymer which is produced in powder form and has an average particle size diameter generally in the range of 100-200 microns. Due to its viscosity, it cannot generally be processed by the usual methods used for ordinary thermoplastics. Therefore, compression molding and plunger extrusion processes are used to generate the high pressures required to fuse the UHMW-PE particles together, which are then generally used to form the material into a stock shape or profile, which is subsequently machined as required. The preferred UHMW is Of those available commercially, ultra-high molecular weight polyethylene (UHMW-PE) is a linear polyethylene with a much higher molecular weight than standard PE. UHMW-PE powder material is commercially available Ticona , Braskem ,DSM , Teijin(Endumax) , Celanese and Mitsui .

[0037] It has been surprisingly found that the UHMW-PE in the TPE liner composition of the present invention has a positive effect on both the tensile strain at yield and the tensile stress at yield, resulting in an excellent liner composition for pressurized containers, such as liner compositions for carbonated beverages (e.g., beer) in pressurized dispensing systems. The liner composition of the present invention is very suitable for pressurized containers and pressurized dispensing systems including BICs and BIBs. Preferred BIB containers are described in EP2148770, EP2146832, and EP2152486.

[0038] Although some of the above-mentioned thermoplastic elastomers can provide a barrier to oxygen to some extent, in order to further enhance such oxygen barrier properties, an oxygen scavenger compound can be added to the liner composition. According to the present invention, the liner formulated with an oxygen scavenger prevents oxygen ingress both in its function as an oxygen barrier and in its function as an oxygen scavenger.

[0039] Preferred oxygen scavenging compounds are selected from the group comprising salicylic acid chelates, complexes of transition metals or their salts, potassium sulfite, interactive mixtures of potassium acetate and sodium sulfite, ferrous salts including ferrous sulfate and ferrous chloride, reducing sulfur compounds including dithionite, ascorbic acid and / or its salts, and reducing organic compounds including catechol and hydroquinone. Preferred oxygen scavenger compounds are sodium sulfite and / or sodium metabisulfite.

[0040] Other additives may also be included, such as catalysts, antioxidants, filler oils, vitamins and salts. Preferred additives include vitamins A, B, D and E, talc and iron and manganese salts.

[0041] The above compounds TPE and UHMW-PE can be combined with the additives (e.g., oxygen scavengers including sulfites and / or lubricants including oils and / or catalysts including salts) in a certain proportion so that the lining composition provides excellent oxygen barrier properties as well as high tensile strength, low compression set and low yield tensile strain, low hardness and low density when forming a liner for a closure, while having a high MFI.

[0042] Thus, in a preferred embodiment, the lining composition may comprise up to 90 parts by weight of a thermoplastic elastomer, up to 30 parts by weight of UHMW-PE, preferably 2-10 parts by weight, highly preferably 5-10 parts by weight of UHMW-PE. In addition, the lining composition may comprise 2-15 parts by weight of an oxygen scavenger, preferably selected from sulfites, such as sodium sulfite and / or sodium metabisulfite. The preferred average particle size of the sulfite is 1-100 microns, highly preferably 10-30 microns. The lining composition may also comprise less than 10 parts by weight of a lubricant, less than 5 parts by weight of a catalyst and optional fillers (e.g. talc).

[0043] The above relative proportions provide a liner composition that can be molded into an effective liner for a closure having the above properties. Although the above proportions can be adjusted, it has also been found that the amount of UHMW-PE is significantly outside the above ranges, which can result in certain properties of the liner being lower than those of a liner comprising UHMW-PE in the above proportions. For example, if the amount of UHMW-PE is significantly lower than the lower limit of the preferred range, the resulting liner may not have the necessary yield stress and yield tensile strain. On the other hand, if the amount of UHMW-PE is significantly greater than the upper limit of the preferred range, the resulting liner may be more difficult to process and too hard, thereby adversely affecting the sealing properties of the liner.

[0044] According to the method for making the liner composition, the above compounds may be processed and mixed in, for example, a twin-screw extruder equipped with a feeder for solid materials and a pump for adding liquid materials.

[0045] After compounding, the liner composition of the present invention can be formed into a liner and combined with a closure shell to provide a closure. The liner of the present invention can be formed into a plate or disc or pad, which can then be cold stamped molded onto the inner surface of the closure shell. Alternatively, a gasket-type shaped liner can be injection molded and placed on the inner surface of the closure shell.

[0046] The liner of the present invention, which has been formed into a disc or pad, may have a thickness of 0.01-20 mm. More typically, the thickness of such a liner disc or pad may be greater near or along the annular periphery of the liner where it contacts the end of the container. Such increased thickness provides increased barrier material where oxygen ingress is most likely to occur (i.e., between the closure skirt and the container).

[0047] The liners of the present invention exhibit good to excellent barrier properties to oxygen ingress and are particularly useful liners for beverage containers. Liners formulated with the liner compositions according to the present invention have oxygen ingress rates under normal atmospheric conditions that are less than commercially available liners. Oxygen ingress can be measured by introducing nitrogen into a container sealed with a liner sample (plate) or a closure equipped with a liner. The nitrogen carries away any oxygen present within the sealed container. The nitrogen leaves the container through an outlet and the level of captured oxygen is recorded as an electronic signal and reported as permeation through one square meter (m2) in one day. 2 ) of the plate or the cubic centimeters (cc) of oxygen entering the package (closure with liner).

[0048] Applications for the compositions according to the present invention include drum sealing applications, crown lining applications, tank linings, plastic closure linings for pressurized containers including BIC and BIB containers.

[0049] The present invention also includes a closure for a container, wherein the closure comprises a closure liner made of the liner composition. In particular, the present invention relates to a metal crown for a beverage container, wherein the metal crown comprises a closure liner made of the liner composition. In addition, the present invention relates to a container, such as a BIB container filled with a product, wherein the container is covered by a closure, the closure comprising a liner made of the liner composition. In particular, the present invention also relates to a bottle filled with a beverage, wherein the bottle is covered by a metal crown, the metal crown comprising a liner made of the liner composition.

[0050] The liner can be adapted to contact the liquid and can form a seal with the lip forming the bottle opening. Thus, the liner can form a majority or all of the contact area of ​​the closure. The liner can be a barrier liner, such as an active or passive barrier liner. The liner can function as a fluid (e.g., liquid or gas) barrier, a flavor barrier, and combinations thereof. For example, the liner can be a gas barrier that inhibits or prevents the passage of oxygen, carbon dioxide, etc. therethrough.

[0051] The liner can be pressed against the lip of the bottle to prevent liquid from escaping from the container sealed by the closure. In one embodiment, the liner is a gas barrier that prevents or inhibits gas from escaping from the container. In another embodiment, the liner is a flavor barrier that prevents or limits changes in the taste of the fluid in the container.

[0052] In some embodiments, the liner can be preformed and inserted into the closure. For example, the closure can be shaped similar to a typical screw cap used to seal a bottle. The liner can be formed by cutting out a portion of a liner sheet, and the precut piece can then be inserted into the closure. Alternatively, the liner can be formed within the closure, whereby the liner can be formed by a molding process (e.g., overmolding).

[0053] Various sets of formulations according to the invention were tested with and without oxygen scavengers. Details regarding liner compositions and liners prepared according to the invention and the advantages provided by the invention will become apparent from the following illustrative working examples and formulations formulated with oxygen scavengers.

[0054]

[0055]

[0056] The blends were prepared using a 26 mm co-rotating twin screw extruder (L / D=44). It was equipped with two gravimetric feeders for solid materials and a peristaltic metering pump for adding liquid materials. Two screw profiles (described in detail below) were used for the study. They will be described in detail below.

[0057] Injection molding

[0058] Molded by injection molding extruder 150×150×2mm 3 Plates of 150 mm diameter and discs of 12.5 mm thickness were used. Standard specimens for determining tensile (ASTM D412) and tear resistance (ASTM D624) tests were obtained by die punches.

[0059] Test specifications:

[0060] Extruder temperature: 155℃

[0061] Mold temperature: 50℃

[0062] Injection speed: High

[0063] Molded by injection molding 80×80×2mm 3 of board.

[0064] Sample preparation for compression set.

[0065] Prior to testing, the specimens were conditioned at 23°C ± 2°C and 50% RH for 24 hours.

[0066] Test specifications:

[0067] Extruder temperature: 155℃

[0068] Mold temperature: 50℃

[0069] Injection speed: High

[0070] The tests were performed using a compression set system with plates.

[0071] The initial thickness of the specimen was 12.5 ± 0.5 mm, which was compressed to a thickness between the plates of 9.5 mm. For the first test, this distance was maintained at 70 ° C for 22 hours, and for the second test, at 125 ° C for 70 hours. After this, the stress was released and the specimen was measured after 30 minutes of relaxation.

[0072] Sample Specifications:

[0073] Comply with ASTM D395(2002)

[0074] Dimensions measured before and after each test

[0075] Test specifications:

[0076] Measurement conditions: 70℃±2℃, for 22 hours.

[0077] 125℃±2℃, for 70 hours.

[0078] Shore A Hardness Tester

[0079] A Shore A hardness tester Zwick was used, and the hardness was measured immediately and 15 seconds after application.

[0080] Sample Specifications:

[0081] Comply with ASTM D2240(2002)

[0082] Thickness at least 6mm

[0083] Test specifications:

[0084] Indenter radius: 35.00±0.25°

[0085] Indenter diameter: 0.79±0.03mm

[0086] Measurement conditions: 23℃±2℃

[0087] Tensile test

[0088] The tests were performed using a tensile testing machine Zwick Z010 with manual grips.

[0089] Prior to testing, the samples were conditioned at 23°C ± 2°C and 50% RH for 24 hours. The following measurements were performed:

[0090] Rp100% (MPa): Strength at 100% elongation

[0091] Rm(MPa): Maximum strength

[0092] E-Rm(%): Elongation at maximum strength

[0093] Nominal E-break (%): Nominal elongation at break

[0094] Percent Elongation: The percent elongation is calculated by reading the change in "gauge length" using an extensometer (25 mm).

[0095] Nominal Elongation "Strain": The nominal strain is calculated by reading the change in grip separation (80mm).

[0096] Sample Specifications:

[0097] Comply with ASTM D412(1998)

[0098] Dimensions measured before each test

[0099] Test specifications:

[0100] Test speed: 50mm / min

[0101] Measuring length: 25mm

[0102] Distance between clamps: 80mm

[0103] Unit force: 2.5kN

[0104] Measurement conditions: 23℃±2℃

[0105] Tear resistance

[0106] The tests were performed using a tensile testing machine Zwick Z010 with manual grips.

[0107] Prior to testing, the specimens were conditioned at 23°C ± 2°C and 50% RH for 24 hours.

[0108] Sample Specifications:

[0109] Comply with ASTM D624(2000)

[0110] Dimensions measured before each test

[0111] Test specifications:

[0112] Test speed: 50mm / min

[0113] Distance between fixtures: 60mm

[0114] Unit force: 2.5kN

[0115] Measurement conditions: 23℃±2℃.

[0116] Melt Flow Index (MFI)

[0117] Test specifications:

[0118] Comply with ASTM D1238(2013)

[0119] Die diameter: 2.095mm

[0120] Temperature: 230℃ and 250℃

[0121] Load: 5kg and 21.6kg

[0122] density

[0123] Density was measured by the Archimedean method according to ASTM D792.

[0124] Sample Specifications:

[0125] Comply with ASTM D792(2008)

[0126] Test specifications:

[0127] Liquid used: Ethanol

[0128] Material weight: about 2g

[0129] Measurement conditions: 23°C

[0130] Result :

[0131] All samples of liner compositions prepared according to the present invention consistently showed excellent results in oxygen ingress, including acting as an oxygen barrier and oxygen scavenger for those formulations having oxygen scavengers, as well as excellent results in tensile strength at yield and tensile elongation at yield.

[0132] Tensile elongation at yield: 390% to 760%

[0133] Tensile strength: 4.9 to 6.6 MPa

[0134] Hardness: 76 to 84.1 Shore A

[0135] Tear strength: 6.5 to 11.6 kN / m

[0136] Density: 0.9-1.1g / cm 3

[0137] Melt flow index of 5kg at 230℃: 1-10g / 10min

[0138] Compression set: 39.7% to 64.3% for 22h / 70°C.

[0139] After sensory evaluation testing with aged samples stored at 23°C, the shelf life and product stability of the liner composition of the present invention were found to be superior to the standard closure on the BIB.

[0140] Oxygen level evaluation was measured on a BIB with a standard liner relative to a liner composition according to the present invention and demonstrated that oxygen ingress was significantly reduced by up to 60% compared to a standard liner composition for BIBs, and even reduced compared to commercial liner compositions for barrels or glass bottles.

Claims

1. Use of a closure liner composition for a container used in a pressurized dispensing system, the closure liner composition comprising a blend of a thermoplastic elastomer and an ultra high molecular weight polyethylene (UHMW-PE), wherein the thermoplastic elastomer is a random or block copolymer of styrene with butadiene or isoprene, the random or block copolymers being selected from the group consisting of styrene butadiene rubber (SBR), styrene butadiene styrene (SBS), styrene isoprene styrene (SIS), hydrogenated SBS (SEBS) and hydrogenated SIS, and wherein the blend comprises 50 to 70 parts by weight of the thermoplastic elastomer and 5 to 10 parts by weight of the UHMW-PE.

2. Use of a closure lining composition according to claim 1, further comprising an oxygen scavenger.

3. Use of the closure lining composition according to claim 2, wherein the oxygen scavenger is sodium sulfite and / or sodium metabisulfite.

4. Use of a closure lining composition according to claim 2, wherein the oxygen scavenger comprises sodium sulfite.

5. Use of the closure lining composition according to claim 1 or 2, further comprising a lubricant and / or a catalyst.

6. Use of a closure liner composition according to claim 1 or 2, the closure liner composition being formed into a closure liner having a tensile elongation at yield between 390% and 760% and a tensile strength between 4.9 MPa and 6.6 MPa.

7. A closure for a container for use in a pressurized dispensing system, wherein the closure comprises a closure liner made from the closure liner composition defined in any one of claims 1 to 2.

8. A container for a pressurized dispensing system, the container being filled with a product, wherein the container is covered by a closure, wherein the closure comprises a closure liner made from the closure liner composition defined in claim 1.

9. The container according to claim 8, wherein the container is a bag-in-container (Bic) or a bottle-in-bottle (BIB) container.

10. A pressurized dispensing system comprising a container according to claim 8 or 9.

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