Use of a gasket insert for PVC-free vessel closures for applications at room temperature or below

Abstract

Use of a sealing insert made of a sealing material which comprises at least one polymer in a mixture with other substances, wherein the sealing material contains no halogen-containing polymers and less than 4 wt.% white oil and between 0.1 wt.% and 70 wt.% TPS, in particular SEBS or SIBS, and between 20 and 60 wt.% of at least one block copolymer, wherein the block copolymer is a copolymer of ethylene with a C3-C8 alpha-olefin, optionally in combination with other unsaturated monomers, and between 10 and 80 wt.% of at least one random copolymer, and the sealing material has a Shore A hardness according to DIN ISO 7619-1 of maximum 90 and a compression set (DVR), determined analogously to DIN ISO 815, of maximum 40% at 20°C and a Shore A hardness of maximum 100 and a DVR of maximum 50% at 4°C, for a vessel closure made of metal or plastic for a vessel for containing food or beverages under vacuum and when filled and / or stored at room temperature and at 4°C.

Description

1. Technical area

[0001] The present invention relates to the use of compounds as sealing material in container closures for food or beverages stored at room temperature (about 20°C) or below, in particular at about 4°C (refrigerator temperature). More specifically, the invention relates to such compositions which are suitable for twist-on (and optionally resealable) container closures or vacuum closures such as cam-turn closures and press-on / twist-off ® -closures are suitable. 2. Background of the invention

[0002] Sealing materials containing polyvinyl chloride (PVC) have long been used in the packaging industry for container closures.

[0003] However, the use of PVC-containing compounds in packaging materials is generally no longer desirable for a variety of reasons. For example, the incineration of household waste from halogenated plastics produces acidic gases, the release of which into the atmosphere is harmful. Furthermore, even small amounts of PVC interfere with the mechanical recycling of plastic waste. Furthermore, PVC-based sealing elements require the use of plasticizers, which can potentially migrate into the food contained in the container and are therefore a health concern.

[0004] The present invention therefore relates to PVC-free sealing materials (hereinafter also referred to as polymer compounds) for vessel closures, in particular for the packaging of foodstuffs.

[0005] Food (including beverages such as juices and the like) is often packaged in glass or plastic containers, which in many cases have a screw cap. A screw cap is a container closure that, when filled and closed, has a threaded engagement with the container. To open the container, the closure must be twisted relative to the container, whereby the seal of the closure lifts away from the container rim and the vacuum - often present - in the container is released. The closure can be separated from the container by such a twist. The well-known PVC-containing sealing materials have the necessary processing and usage properties for this.It should therefore be noted that a PVC-free sealant only represents a commercially interesting sealing material for vessel closures if the PVC-free sealant has very specific physico-chemical properties that are not inferior to those of PVC-containing sealing materials in essential properties.

[0006] Further requirements for such sealing materials include, for example, the following aspects: - The material composition should be selected to avoid undesirable substances. Therefore, the sealing material should not contain substances classified as hazardous to health, in particular plasticizers such as phthalates; semicarbazide and its sources, especially ADC and OBSH; 2-ethylhexanoic acid and its sources; organotin compounds; primary aromatic amines; bisphenols, nonylphenol; BADGE; photoinitiators; perhalogenated compounds; and melamine.

[0007] For some applications, the presence of large amounts of liquid substances (at room temperature) is undesirable. In these cases, the content of such substances (such as white oil) should be limited to a maximum of 10%, preferably less, and in some cases, the sealing material should not contain any detectable levels of such liquid substances. This is especially true for the filling of fatty foods.

[0008] The material composition should be selected so that the sealing material meets even the most demanding requirements during use.

[0009] For some applications, the sealing material should have a barrier function, i.e. reduce or prevent the penetration of unwanted substances into the vessel.

[0010] For special applications, it should be possible to equip the sealing material with absorbent additives (e.g. oxygen absorbers) or other scavenger substances. - The sealing material must have the required processing properties.

[0011] In principle, it must be able to be thermally softened sufficiently to be used on conventional processing machines (particularly in the injection molding process, but also for extrusion with subsequent stamping or compression molding).

[0012] However, after being introduced into the vessel closure and cooled to the desired application temperature (usually room temperature, but possibly also at lower temperatures, e.g. in a refrigerated cabinet), it must have the required sealing properties.

[0013] For small vascular occlusions, the sealing material must also be able to be applied over the entire surface.

[0014] For PT caps (Press-on Twist-off ®Closures) the sealing material must form both the seal and the internal thread of the cap, and must therefore be able to be applied (as a so-called "contoured ring") to both the inner surface and the skirt of the cap, and must be able to form the mechanically (sufficiently stable) thread elements when the cap is pressed on.

[0015] For some applications, the sealing material should be able to be formed "out shell", i.e. outside the closure to form a sealing insert, which is then inserted into the vessel closure as a finished sealing ring or similar.

[0016] The sealing material should be particularly suitable for metal closures and metal-plastic composites, which may be coated on the inside, but it should also be suitable for plastic closures. - The sealing material must be suitable for standard food packaging.

[0017] The sealing insert should have sufficient vacuum retention even in cold conditions.

[0018] The sealing insert should be suitable for common containers made of metal, plastic, glass, etc.

[0019] In contact with the contents, especially with fatty foods and other products with a lipophilic character (compared to water), the sealing insert should not release any or as few components as possible to the contents, and should also not absorb any lipophilic components from the contents.

[0020] The gasket insert must exhibit sufficiently low opening values ​​to allow the container closure to be removed with appropriate force (if refrigerated, if necessary). At the same time, the gasket must maintain its sealing effect throughout the intended shelf life (best before date) of the food.

[0021] WO 2011 / 060803 A1 describes polymer compounds for a sealing insert of a vessel closure, in particular for fatty filling materials. 3. Summary of the invention

[0022] In general, according to the invention, polymer compounds (here also referred to as compositions) are used as sealing material (or sealing compound).

[0023] In general, a sealing material according to the invention comprises a mixture of chemically different components, which typically comprises at least two different polymers and further components such as lubricants, stabilizers and optionally further components which serve to adjust the desired performance properties.

[0024] Special considerations apply to foods that are stored at room temperature (RT, e.g., 20°C) or refrigerated (e.g., 4°C) and are not usually pasteurized or sterilized. These can include foods containing fat, low-fat foods, or fat-free foods. Such foods can, for example, be cold-filled and refrigerated until consumption; however, they also include products that are filled at RT or even hot, but subsequently stored at RT or refrigerated. They include products in containers in which a vacuum is created by negative pressure or by means of cooling steam.

[0025] Examples of such foods are: 1. Yogurt & desserts: high-fat, cold filling, vacuum if necessary, transport and storage in the cold chain; 2. Cheese in oil (e.g. feta): fatty, to be filled cold or at room temperature, if necessary vacuum, transport and storage in the cold chain; 3. Fish in oil (e.g. pollock substitute): fatty, cold filling, if necessary vacuum, transport and storage in the cold chain; 4. Mustard: contains fat as defined in Regulation (EU) 10 / 2011, filling up to approx. 50°C, if necessary vacuum, transport and storage at room temperature; 5. Jam: fat-free, hot-filled, vacuum-packed if necessary, transport and storage at room temperature; 6. Mayonnaise: contains fat, to be filled cold, if necessary vacuum, transport and storage at room temperature;

[0026] Vessel closures for these applications are usually twist-lock closures, such as cam-type twist-lock closures. Such closures are opened by twisting the closure relative to the vessel, with the sealing insert sliding along the vessel rim, with which it forms the seal. This lifts the closure from the vessel rim, breaking any existing vacuum. In such applications, in addition to the requirements already mentioned above, the sealing insert must allow the vessel to be opened easily, even at low temperatures, e.g., when stored in refrigerators. A key criterion for this is the opening value, which represents the maximum torque required to unscrew the closure (i.e., to open the vessel).

[0027] The sealing materials disclosed in our earlier patent application PCT / EP2011 / 057652 are partially suitable for such applications, but the focus there is on the heat sterilizability of the sealing material, which is generally not important for the foods discussed here. This makes it possible to tailor the sealing materials within the scope of this invention even more specifically to the requirements (particularly with regard to the opening value) that arise for foods of the type mentioned above.

[0028] Other parameters that can be used to characterize suitable sealing materials are their Shore A hardness and compression set (DVR), both specifically at 20°C and 4°C, and the stress loss in the creep test (compression by 25% at 70°C, then free cooling), as described below.

[0029] If the food and beverages considered in the invention are exceptionally sterilized after filling and sealing the container, a sealing insert that can withstand such measures is particularly desirable. The suitability of the sealing material for sterilization measures can, if necessary, be easily determined using dynamic mechanical thermal analysis (DMTA), as described in our aforementioned application PCT / EP2011 / 057652.

[0030] The vessel closures considered here are used at temperatures (room temperature and below, down to approximately 0°C) at which conventional oil- and PVC-free sealing materials are too hard and inelastic, exhibiting excessively high opening values. The closures according to the invention meet the requirements significantly better in terms of the (lower) hardness and elasticity (DVR) of the sealing material, as well as their opening value at low temperatures.

[0031] The invention provides polymer compounds as sealing materials that enable these physical properties.

[0032] The objects underlying the present invention are achieved by the PVC-free sealing materials defined in the independent claims. Advantageous embodiments are defined in the subclaims.

[0033] The invention takes into account that different filling materials place additional demands on the sealing material. In particular, with fat-free filling materials it is possible and also very sensible to adjust the properties of the sealing material (also) using an oil component. However, this may not be desirable if the filling material contains fat. A more detailed discussion of this problem can be found, for example, in our older application WO 2011 / 060803. In such cases, the physical parameters must be adjusted by adding suitable plasticizing components to the sealing material that are not liquid (at RT), and in particular are not oily. Certain "soft" polymers are suitable for this purpose and are selected so that they meet the requirements of the invention.

[0034] The embodiments of the invention that contain little or no oil are generally suitable for all applications within the scope of the invention. The oil-containing embodiments are preferably not used for fatty fillings.

[0035] The PVC-free compositions according to the invention can be rendered sufficiently flowable by heating. Only then can the sealant be applied to the vessel closure blank by extrusion or a similar process in the area of ​​the sealing element to be produced (also referred to as a seal or sealing insert).

[0036] The PVC-free composition applied to the inside of the vessel closure can then be mechanically formed into the desired sealing element. After cooling, the applied composition retains its shape and, when closed, forms a seal against the opening of the vessel to be sealed with the vessel closure.

[0037] The PVC-free composition can be used preferably in the production of any container closures, such as for the production of seals in cam screw caps, screw caps, rotating crown caps, bottle screw caps and press-on twist-off ® closures.

[0038] The PVC-free compositions according to the invention therefore comprise in particular a sealing material suitable for vascular closures, which • is easy to process, • enables fast throughput in industrial production, • can be used for filling and / or storage at room temperature and refrigeration, • with the appropriate recipe, can even be used with fatty fillings, • is based largely or entirely on non-crosslinked polymers and is completely or essentially free from substances that are harmful to health (such as plasticizers and the like), • is cost-effective, and / or • allows the production of vascular closures which, when closed, exhibit a gas barrier effect, a pressure relief valve effect and / or a vacuum retention effect. 4. Definitions

[0039] In the context of the present invention, the term "PVC-free composition" refers to a composition that comprises less than 1% by weight, preferably less than 0.5% by weight, more preferably less than 0.1% by weight or less than 1% by weight, and most preferably (within the limits of analytical determination) no PVC at all (in each case based on the total weight of the PVC-free composition). In the context of the present invention, only those compositions that can be used as a sealant in vessel closures are considered to be "PVC-free compositions". For example, a hot melt adhesive or a pure polymer is not a "PVC-free composition" in the context of the present invention, even if it does not contain any PVC.

[0040] In the context of the present invention, the term “plastic” refers to a material comprising at least one synthetic or semi-synthetic polymer.

[0041] In the context of the present invention, the term "block copolymer" refers to a copolymer consisting of longer sequences or blocks of each monomer (e.g., AAAAAAAAABBBBBBBBBBBB...). More specifically, the invention utilizes so-called "statistical multiblock resins," such as those available from DOW Chemical Co. under the name "Infuse."

[0042] In the context of the present invention, the term "random copolymer" refers to a copolymer having a random distribution of monomers, more particularly a copolymer of the type available from DOW Chemical Co. under the name "Engage".

[0043] In the context of the invention, a TPO is understood to mean a thermoplastic elastomer based on olefins (TPE-O); a TPS is understood to mean a styrene block polymer (TPE-S).

[0044] Room temperature in the context of the invention is generally about 20°C. 5. Test procedures for physical parameters

[0045] The opening value in the sense of the present invention is the maximum torque required to open the closed vessel by turning the vessel closure.

[0046] The opening value is determined using a torque sensor into which the sealed container is inserted and then opened manually or (semi-)automatically. A suitable device is available, for example, from Steinfurth under the designation "Torque Measuring System TMS 5000."

[0047] For this test, vessels of the type for which the closure is intended are selected to be representative in terms of the quality of their mouth (evenness of the rim, etc.). The vessels are preferably filled with the product for which they are intended, or alternatively with water or vegetable oil. The fill level in the vessel corresponds to the fill level during the intended use. These vessels are then sealed as intended with the vessel closures to be tested, with the vacuum being adjusted by the amount of steam used, its water content and temperature, as well as the remaining headspace above the contents. Alternatively, the vacuum can also be generated in a chamber using pumps. The closure is then placed in this chamber and sealed by a rotating movement. In the case of a "mechanically" generated vacuum, values ​​of -0.3 bar are typically obtained, and -0.6 bar for vessels sealed with steam.

[0048] Where opening values ​​are discussed in this description, they always refer to vessels evacuated in this way at a vacuum of approximately -0.5 bar.

[0049] The vessels are then stored at 4°C.

[0050] Since the opening value often initially increases at constant storage temperature and then decreases to a stable value, the opening value was determined after a corresponding storage period. Typically, an initial value was determined immediately, followed by measurements after 1, 2, 5, 7, and 14 days, after 4 weeks, and after 3 months. A constant value was usually established within 4 weeks.

[0051] The measurements were performed in parallel on several vessels (usually at least 10, preferably up to 40 vessels) so that an average value could be calculated from the measured data. The opening values ​​given in this description are average values ​​of at least 10 vessels, with the vacuum set to approximately 0.5 bar, and after storage at 4°C for the number of days specified in the example.

[0052] The diameter of the vessel closures was 70 mm. According to the invention, the opening value in inch lbs is preferably a maximum of half the diameter of the closure in mm, i.e., for a diameter of 70 mm, a maximum of approximately 35 inch lbs. For other diameters, the opening value according to the invention is calculated using the same formula.

[0053] The permissible range of variation is preferably a maximum of 20% of the mean value, ie with a mean opening value of 35 inch·lbs, the closures according to the invention can be between 28 and 42 inch·lbs (preferably closer to the mean value, of course).

[0054] The Shore A hardness is determined according to DIN ISO 7619-1.

[0055] The compression set DVR is determined analogously to DIN ISO 815.

[0056] By measuring the stress loss in the creep test, the behavior of the compound is intended to approximate real filling conditions.

[0057] For this purpose, a sample piece is produced from the polymer compound (usually by injection molding) which has a diameter of 20 mm and is 6 mm high or thick.

[0058] For testing, the specimen is clamped into a universal testing machine. Such machines are available, for example, under the designation LR5kN from Lloyd Instruments.

[0059] The specimen is conditioned at 70°C in the testing machine's heat chamber and compressed by 25% at a force of 1 mm / min. After the compression is established, heating is stopped and the heat chamber door is opened. The system is allowed to cool naturally. The force opposing the compression is measured and recorded using a force transducer. 6. Detailed description of the invention

[0060] Vessel closures according to the invention, as defined by their physical parameters (Shore A hardness, DV, opening value, stress loss), are generally suitable for all food and beverages. Differences in the compositions of the corresponding sealing materials arise from the properties of the contents, in particular from whether the products are fatty or fat-free. For fat-free products, the required physical properties can be adjusted (in part), for example, by an oil content in the compound that is higher than in known sealing materials for applications at higher temperatures. For fatty products, relevant oil contents are preferably avoided because oil from the compound could penetrate into the product and / or fatty components of the product could penetrate into the sealing material.

[0061] In embodiments of the invention which are also suitable for use with products containing a high fat content, the compound of the sealing material is based on a TPS, in particular SEBS in a mixture with an ethylene-octene copolymer, in particular a random copolymer.

[0062] For such applications, a SEBS of the type Kraton ® G with a polystyrene content of 11.5 - 13.5% and a Shore A hardness of approximately 35 is particularly suitable. Such SEBS are flowable and have a reduced absorption capacity for oil.

[0063] Other components preferably used are TPOs, i.e., polyolefin elastomers, especially PP elastomers, and ethylene-octene block copolymers. If higher SEBS contents are acceptable, the compound can be equipped with harder polymers such as LDPE.

[0064] In all these embodiments, the sealing material contains less than 5% oil and is preferably oil-free.

[0065] When using polyolefin elastomers, the content of lubricants (especially fatty acid amides) is generally higher.

[0066] The TPS component preferably consists of SEBS, especially of the Kraton® G type. The TPS content is generally between 5 and 70%, more specifically between 10 and 30%.

[0067] The ethylene-octene copolymer is preferably a random copolymer, such as the Engage® type. The content ranges from 10 to 80%, more specifically from 20 to 60%, and preferably from 20 to 35%.

[0068] The polyolefin elastomer is preferably a PP elastomer, especially of the Vistamaxx® type. The TPO content ranges from 10 to 50%, more specifically from 30 to 45%.

[0069] If the compound contains a TPO, preferred variants include a content of rigid polyolefin, especially propylene homopolymer. The rigid polyolefin content is generally between 0 and 30%, more specifically between 15 and 25%.

[0070] Especially in variants without TPO content, the compound preferably contains significant amounts of ethylene-octene block copolymer, such as Infuse®. The content ranges from 10 to 80%, more specifically from 20 to 60%, and preferably from 40 to 50%.

[0071] When using higher TPS contents (above 25%), a hard polyolefin such as LDPE can be used instead.

[0072] In these variants, the lubricant content can be low, at 1% or less. Example 1: SEBS 24% PP elastomer 40.3% Homo-PP 18% random copolymer 12.5% pigment 0.3% lubricant 4% stabilizer 0.2% Shore A hardness at 20°C: 78; at 4°C: 85 DVR at RT: 32%; at 4°C: 47% Opening values ​​at 4°C for 70mm closures, 5 days: about 37 inch·lbs ; 27 days: about 43 inch·lbs Voltage loss: 51% Example 2: SEBS 25% random copolymer 28% Block copolymer 45.5% lubricant 1% Pigment, stabilizer 0.5% Shore A hardness at 20°C: 68; at 4°C: 72 DVR at RT: 13%; at 4°C: 28% Opening values ​​at 4°C for 70mm closures, 5 days: about 35 inch lbs; 28 days: about 37 inch lbs Voltage loss: 55%

Claims

[1] Use of a sealing insert made of a sealing material which comprises at least one polymer in a mixture with other substances, wherein the sealing material contains no halogen-containing polymers and less than 4 wt.% white oil and between 0.1 wt.% and 70 wt.% TPS, in particular SEBS or SIBS, and between 20 and 60 wt.% of at least one block copolymer, wherein the block copolymer is a copolymer of ethylene with a C3-C8 alpha-olefin, optionally in combination with other unsaturated monomers, and between 10 and 80 wt.% of at least one random copolymer, and the sealing material has a Shore A hardness according to DIN ISO 7619-1 of maximum 90 and a compression set (DVR), determined analogously to DIN ISO 815, of maximum 40% at 20°C and a Shore A hardness of maximum 100 and a DVR of maximum 50% at 4°C, for a vessel closure made of metal or plastic for a vessel for containing food or beverages under vacuum and when filled and / or stored at room temperature and at 4°C. [2] Use according to claim 1, wherein the sealing material does not contain any components which are liquid at 20°C within the limits of determination. [3] Use according to claim 1 or 2, characterized by that the sealing material contains between 40 and 50 wt.% of the block copolymer. [4] Use according to claim 3, characterized by that the block copolymer has a density of 0.85 to 1.1 g / cm 3and preferably has a melt flow index (MFI) of 0.01 g / 10 min to 1000 g / 10 min, in particular an MFI of 1 g / 10 min to 100 g / 10 min, at a load of 5 kg at 190°C. [5] Use according to claim 3 or 4, characterized by that the block copolymer is formed from ethylene and an alkene, in particular selected from propene, butene, hexene and octene, and particularly preferably octene. [6] Use according to one of claims 3 to 5, characterized by that the sealing material contains between 20 and 60 wt.%, particularly preferably between 20 and 35 wt.% of at least one random copolymer, wherein the random copolymer is preferably a linear copolymer of ethylene and a C3-C 20 -alpha-olefin or a branched copolymer of ethylene and a C3-C 20 -alpha-olefin. [7] Use according to claim 6, characterized by that the random copolymer has a density of 0.85 to 1.1 g / cm 3and preferably has a melt flow index (MFI) of 0.15 g / 10 min to 100 g / 10 min. [8] Use according to one of claims 6 and 7, characterized by that the random copolymer comprises two alkenes, in particular selected from ethylene, propene, butene, hexene and octene, and especially ethylene and octene. [9] Use according to claim 8, wherein at least one copolymer is polymerized by metallocene catalysis. [10] Use according to any one of claims 1 to 9, characterized by that the sealing material contains up to 50 wt.%, in particular up to 25 wt.% of polyolefins with a Shore D hardness above 60, and preferably HDPE and / or PP or (co)PP and / or those with a Shore D hardness below 60 and preferably LLDPE and / or LDPE, and preferably comprises at least one propylene-based polymer which has a melting range above 90 °C. [11] Use according to any one of claims 1 to 10, wherein the sealing material contains between 1 wt% and 70 wt%, more preferably between 5 wt% and 70 wt% and especially from 10 to 40 wt% of TPS, in particular SEBS or SIBS. [12] Use according to one of claims 1 to 11, wherein the sealing material contains 10 to 80 wt.% TPO, preferably 30 to 45 wt.% TPO, preferably PP elastomer. [13] Use according to any one of claims 3 to 12, wherein the sealing material contains up to 60 wt% TPS, up to 60 wt% ethylene-octene block copolymer and up to 40 wt% random ethylene-octene copolymer. [14] Use according to one of the preceding claims, wherein the sealing material has a Shore A hardness of between 20 and 90, preferably between 50 and 85 and particularly preferably between 60 and 80 at 20°C, and preferably a Shore A hardness of between 50 and 100, preferably between 70 and 90 and particularly preferably not more than 85 at 4°C. [15] Use according to one of the preceding claims, wherein the sealing material has a DVR of at most 35%, particularly preferably at most 20%, at 20°C and preferably a DVR of at most 40%, particularly preferably at most 30%, at 4°C. [16] Use according to one of the preceding claims, in which the sealing material has a stress loss of not more than 80%, preferably not more than 60%, in the creep test (compression at 70°C by 25%, then free cooling). [17] Use according to one of the preceding claims, in which the vessel closure can be opened by twisting and the sealing material is composed such that the vessel closure at 0.5 bar vacuum in the vessel after 5 days of storage of the closed vessel at 4°C and based on a diameter of the closure of 70 mm, has an average opening value of less than 508 cNm, preferably less than 475 cNm, more preferably less than 452 cNm and particularly preferably not more than 395 cNm. [18] Use according to one of the preceding claims, wherein the sealing insert is arranged in the vessel closure so that it lies sealingly against the opening of the vessel in the closed state, wherein the vessel closure is preferably made of metal. [19] Use according to any one of the preceding claims, characterized bythat the vessel closure corresponds to an inner diameter of the vessel opening of more than 2.5 cm, preferably more than 3 cm, more preferably of at least 3.5 cm, particularly preferably of at least 3.8 cm and in particular of more than 4 cm, and specifically is 58, 63, 66 or 70 mm. [20] Use according to any one of the preceding claims, characterized by that the vessel closure is designed as a screw cap for a bottle, a glass or the like. [21] Use according to any one of the preceding claims, wherein the vessel closure is a cam-turn closure, a press-on twist-off ® Closure, a metal-plastic composite closure (e.g. Bandguard ® ), a slip lid, a crimp-on or disposable closure (e.g. Pano AK®) or a roll-on metal closure. [22] Use according to any one of the preceding claims, characterized by that the sealing insert is used as an inner insert on the inner surface and with Press-on Twistoff® closures is also formed on the apron of the vessel closure (“contoured ring”). [23] Use according to claim 22, characterized by that the sealing insert is ring-shaped or circular disc-shaped. [24] Use according to any one of the preceding claims, characterized by that the vessel closure has a gas barrier effect and / or a pressure relief valve effect when closed. [25] Use according to any one of the preceding claims, characterized by that the vessel closure shows vacuum retention in the closed state. [26] Use according to any one of the preceding claims, wherein the sealing material is selected so that the closure complies with the provisions of Regulation (EC) 1935 / 2004. [27] Use according to any one of the preceding claims, wherein the sealing material is selected so that the closure complies with the provisions of Regulation (EC) 2023 / 2006. [28] Use according to any one of the preceding claims, wherein the sealing material is selected so that the closure complies with the provisions of EC Directive 2002 / 72 / EC. [29] Use according to any one of the preceding claims, wherein the sealing material is selected so that the closure complies with the provisions of Regulation (EU) 10 / 2011. [30] Use according to one of the preceding claims, wherein the sealing material does not contain any plasticizers, in particular no phthalates. [31] Use according to one of the preceding claims, wherein the sealing material contains, based on its total weight, less than 30 wt.%, preferably less than 20 wt.%, more preferably less than 10 wt.%, particularly preferably less than 5 wt.%, and especially no crosslinked polymer at all.