阅读说明：本技术 容器封盖密封件垫片、容器封盖、聚合物组合物和应用 (Container closure seal gasket, container closure, polymer composition and use ) 是由 瓦尔德马·艾希勒 吕迪格·维滕贝格 于 2013-07-22 设计创作，主要内容包括：本发明涉及一种用于容器封盖的不含PVC的密封件垫片的聚合物组合物,所述聚合物组合物配有至少一种除氧化合物,其中聚合物组合物的邵氏D硬度为至少20并且聚合物组合物具有至少为5的熔体流动指数(190℃,5kg)。(The invention relates to a polymer composition for a PVC-free sealing element gasket for a container closure, which is provided with at least one oxygen scavenging compound, wherein the polymer composition has a Shore D hardness of at least 20 and the polymer composition has a melt flow index (190 ℃, 5kg) of at least 5.)

1. A polymer composition for a PVC-free gasket for a container closure, the polymer composition being provided with at least one oxygen scavenging compound, characterized in that the polymer composition has a shore D hardness of at least 20 and the polymer composition has a melt flow index of at least 5, at 190 ℃ and 5kg, wherein the polymer composition comprises a rubbery barrier polymer, and the rubbery barrier polymer is polyisoprene, polyisobutylene, SIBS, or polybutene.

2. The polymer composition of claim 1, which is composed such that the polymer composition substantially comprises a combination of a rubbery barrier polymer and a polyolefin, but the polymer composition does not comprise an oil.

3. The polymer composition according to claim 1 or 2, characterized in that it has a shore D hardness of 20 to 60.

4. The polymer composition according to claim 1 or 2, characterized in that it has a shore D hardness of 40 to 50.

5. Polymer composition according to claim 1 or 2, characterized in that the polymer composition comprises sodium sulfite as oxygen scavenging compound.

6. The polymer composition according to claim 5, characterized in that the sodium sulfite has an average particle size of less than 20 microns.

7. The polymer composition according to claim 5, characterized in that the sodium sulfite has an average particle size of less than 12 microns.

8. The polymer composition according to claim 5, characterized in that the sodium sulfite has an average particle size of less than 7 microns.

9. Polymer composition according to claim 1 or 2, characterized in that the polymer composition comprises between 1% and 10% sodium sulfite as oxygen scavenging compound.

10. Polymer composition according to claim 1 or 2, characterized in that the polymer composition comprises 4 to 8% of sodium sulfite as oxygen scavenging compound.

11. A polymer composition for a PVC-free seal gasket for a container closure, said polymer composition comprising at least one polyolefin and at least one rubbery barrier polymer according to claim 1, but substantially no oil, wherein said polymer composition comprises at least one different further polymer which reduces the overall hardness of the composition, shore D hardness, compared to a corresponding composition not comprising said further polymer, wherein the shore D hardness of said polymer composition comprising all of said polymers is at least 20 and said polymer composition has a melt flow index of at least 5, at 190 ℃ and 5 kg.

12. The polymer composition of claim 11, wherein the polymer composition comprises up to 50% of a rubbery barrier polymer, wherein the rubbery barrier polymer is polyisoprene, polyisobutylene, SIBS, or polybutene.

13. The polymer composition of claim 11, wherein the polymer composition comprises up to 40% of a rubbery barrier polymer, wherein the rubbery barrier polymer is polyisoprene, polyisobutylene, SIBS, or polybutene.

14. The polymer composition of claim 11, wherein the polymer composition comprises up to 25% of a rubbery barrier polymer, wherein the rubbery barrier polymer is polyisoprene, polyisobutylene, SIBS, or polybutene.

15. The polymer composition of claim 11, wherein the polymer composition comprises at least 10% of a rubbery barrier polymer, wherein the rubbery barrier polymer is polyisoprene, polyisobutylene, SIBS, or polybutene.

16. The polymer composition of claim 11, wherein the polymer composition comprises at least 15% of a rubbery barrier polymer, wherein the rubbery barrier polymer is polyisoprene, polyisobutylene, SIBS, or polybutene.

17. The polymer composition of claim 11, wherein the polymer composition comprises at least 20% of a rubbery barrier polymer, wherein the rubbery barrier polymer is polyisoprene, polyisobutylene, SIBS, or polybutene.

18. The polymer composition according to any of claims 11 to 17, characterized in that the polymer composition comprises up to 80 wt.% HDPE.

19. The polymer composition according to any one of claims 11 to 17, characterized in that it comprises up to 70% HDPE.

20. A polymer composition according to any one of claims 11 to 17, characterized in that the polymer composition comprises up to 60% HDPE.

21. A polymer composition according to any one of claims 11 to 17, characterized in that the polymer composition comprises at least 30% HDPE.

22. A polymer composition according to any one of claims 11 to 17, characterized in that the polymer composition comprises at least 40% HDPE.

23. A polymer composition according to any one of claims 11 to 17, characterized in that the polymer composition comprises at least 50% HDPE.

24. The polymer composition according to any of claims 11 to 17, characterized in that it comprises between 5% and 25% of low density polyethylene, L DPE.

25. A polymer composition according to any one of claims 11 to 17, characterized in that the polymer composition comprises no more than 4% of a lubricant.

26. A polymer composition according to any one of claims 11 to 17, characterized in that the polymer composition comprises no more than 1% of a lubricant.

27. A polymer composition according to any one of claims 11 to 17, characterized in that the polymer composition comprises not more than 10% by weight of oil.

28. A polymer composition according to any one of claims 11 to 17, characterized in that the polymer composition comprises not more than 5% by weight of oil.

29. The polymer composition according to any of claims 11 to 17, characterized in that the polymer composition does not comprise oil at all.

30. The polymer composition according to any one of claims 11 to 17, characterized in that it comprises up to 30% of linear low density polyethylene LL DPE.

31. The polymer composition according to any of claims 11 to 17, characterized in that it comprises up to 10% of linear low density polyethylene LL DPE.

32. The polymer composition according to any of claims 11 to 17, characterized in that it comprises not more than 5% by weight of linear low density polyethylene LL DPE.

33. The polymer composition according to any one of claims 11 to 17, characterized in that it comprises at least one block copolymer of ethylene with at least one C₃-C₁₀α interpolymers of olefins or ethylene with C₃-C₂₀α and making up to 25% by weight of the polymer composition.

34. The polymer composition according to claim 33, wherein the block copolymer is ethylene with at least one C₃-C₁₀α interpolymers of olefins in combination with other unsaturated monomers or ethylene and C₃-C₂₀α copolymers of olefins in combination with other unsaturated monomers.

35. The polymer composition of claim 33, wherein the block copolymer comprises up to 20 wt.% of the polymer composition.

36. The polymer composition according to claim 33, wherein the block copolymer constitutes between 5 and 15 wt.% of the polymer composition.

37. The polymer composition according to any of claims 11 to 17, characterized in that it has an EVA content amounting to at least 5 wt.%.

38. The polymer composition according to any of claims 11 to 17, characterized in that it has an EVA content amounting to at least 8 wt.%.

39. The polymer composition according to any of claims 11 to 17, characterized in that it has an EVA content amounting to at least 10% by weight.

40. The polymer composition of claim 37, wherein the polymer composition also has a block copolymer content of up to 25 wt.% of the polymer composition.

41. The polymer composition of claim 37, wherein the polymer composition also has a block copolymer content of up to 20 wt.% of the polymer composition.

42. The polymer composition according to claim 37, wherein the polymer composition also has a content of block copolymer comprised between 5 and 15% by weight of the polymer composition.

43. The polymer composition according to any one of claims 11 to 17, comprising an additive.

44. The polymer composition of claim 43, the additives being a wax and a silicone.

45. A container closure seal gasket comprising the polymer composition of any one of claims 1 to 44.

46. A container closure with a sealing gasket comprising the polymer composition of any one of claims 1 to 44.

47. Use of the polymer composition according to any one of claims 1 to 44 for the manufacture of a seal gasket for a container closure.

48. The use according to claim 47, wherein the container closure is a bottle closure or a sealing cap.

49. Use according to claim 47, wherein the container closure is a crown cap.

Technical Field

The present invention relates to a PVC-free polymer composition that protects beverages from oxygen by a combination of a passive oxygen barrier process and an oxygen-binding compound (scavenger) in the seal used for closures.

Background

Oxygen sensitive beverages and foods are of great economic importance worldwide. Beer, wine, fruit juices and tea-based refreshing beverages are the primary ones. In order to be able to preserve the filling as long as possible without altering its flavour and composition, a series of processes have been developed in the packaging industry.

Thus, for example, in the case of bottles made of PET and similar plastics, they are processed with single-layer or multi-layer composites which should reduce oxygen ingress. Polymers which are customary in this case are, in particular, polyamides or ethylene vinyl alcohol copolymers (EVOH). As an alternative to having a passive barrier, an extremely thin coating of carbon or silicon oxide may be applied into the bottle interior. US 8377530B 2 also describes the use of low molecular weight additives composed of aromatic amide species.

In glass bottles with metal closures it is preferred to use the barrier process as described in EP-0503124 a 1. But in addition to this oxygen scavenging compounds as described in EP-0328337B 1 are also applied. Both of these processes are used for crown cap seals, but have heretofore been limited to use in so-called "pry-open crown caps".

Advantageously, the method comprises the following steps: use of such a composite article for the sealing of container closures, said composition not comprising a PVC component, whether in the form of ordinary PVC or in the form of particularly flexible PVC. In the usual incineration of household waste, acid-containing gases are generated from halogen-containing plastics, which are harmful to the atmosphere. In addition, small amounts of PVC already interfere with the material recovery of the plastic waste. In addition, PVC-based flexible sealing elements require the use of plasticizers, which are also hazardous for health reasons.

There is therefore a need for a container closure having a polymer-based sealing liner and preferably containing an oxygen scavenging component, but not based on PVC.

The polymer composition or simple composition described below is understood here as meaning, as is customary in the industry, a mixture of one or more polymers with further constituents (for example viscosity regulators, chain extenders, fillers, pigments, antioxidants, lubricants) for adjusting the desired application properties. The application properties relate to the behaviour of the composition from its manufacture via application when manufacturing a closure for a container (for example when introducing it into a closure blank to produce a sealing gasket), and also to the properties of the closure when using the consumer in the conventional application of the container and when filling and storing the container (for example opening, removing a beverage or food, reclosing of the container).

From WO 2011/069520 it is already known: PVC-free polymer compositions have been used exclusively for screw crown caps to which an oxygen-scavenging component (also referred to as "scavenger") has been added. Herein, sulfite particles having a specific average particle size are preferred. The reduction of oxygen ingress is achieved by the sulfite content, while the composition itself (i.e. irrespective of its scavenger content) does not necessarily have to have a defined barrier function.

The composition proposed in WO 2011/069520 is based on polypropylene and polyethylene with SEBS content, in particular L DPE (low density polyethylene) and LL DPE (linear low density polyethylene), SEBS does not have useful barrier properties.

For many applications, however, oil content in the container seal is undesirable. The oil can promote migration of substances into and through the container seal, which reduces the barrier effect of the seal. Whereby the greater ingress of oxygen and other volatile substances can compromise product characteristics, if necessary.

To inhibit this effect, it is proposed, for example, in WO 2011/060803: compositions are used which are free of oil, in particular for fat-containing fillings. The barrier properties, which are enhanced by scavenger substances, are not important here if necessary.

An important function of the compositions currently concerned is to create a sealing gasket in the container closure. The sealing gasket should not only prevent the outflow of the filling but also protect the filling from contamination by substances to which the filled and closed container can be exposed during storage and transport. Furthermore, for screw closures additives are used which allow easy removal of the filling and also easy reclosing without problems.

Therefore, the container seal should furthermore prevent oxygen from reaching the filling. Other important functions are to limit the undesired ingress of volatile compounds which can originate, for example, from recycled packaging, such as shrink film, cardboard wood panels. Especially in the case of beverages (beer, fruit juices, mineral water) filled in bottles and closed with crown caps and caps, it is important: inhibiting the entrance of TCA (trichloroanisole) and other volatile organic carbon compounds (VOC).

In conventional container closures, the ingress of such substances (oxygen, TCA, etc.) occurs in the sealed container, since the closure is not able to prevent the ingress of such substances. The harmful substance migrates (e.g. due to its solubility in the composition) through the seal into the container and into the filling.

The opposite effect is also undesirable, i.e. the penetration of constituents of the filling into the seal. This can be problematic, for example, in oil-containing fillings or flavoured beverages.

In the prior art, the industry itself has hitherto been restricted to the use of compositions which either (without addition of a scavenger) exhibit barrier action (in which the entry of harmful substances into the seal has been prevented by design) or have scavenger additives (in which the entry of harmful substances has therefore not been prevented by design, but which then should be harmless in the seal). However, no sealing gasket has been used so far, which may combine the barrier concept with the scavenger concept, since both concepts have been regarded as mutually exclusive alternatives so far.

Disclosure of Invention

Thus, in a particularly preferred embodiment, the present invention comprises a composition that advantageously combines the barrier concept with the scavenger concept. The protection of beverages against oxygen, for example, can be optimized by the combination of passive oxygen barrier technology with oxygen-binding compounds (scavengers) in the sealing material.

Thus yielding unexpected advantages. On the one hand, compositions can be produced which achieve a finished seal in an extended hardness range. Commonly used barrier compositions in container closures are relatively hard (i.e. shore a or shore D hardness is relatively high). Greater design latitude is advantageous here.

Another aspect shows: the barrier composition used according to the invention has a higher absorption capacity for water in the presence of scavenger particles, which in turn leads to an improved activation of the scavenger particles. There is an unexpected synthetic effect which, if necessary, achieves a reduction in the effective content of scavenger particles, which in turn not only leads to a reduction in costs, but also to easier and more flexible processing.

The composition according to the invention can be used for all types of bottle closures, such as crown caps, aluminium closures and caps (for example plastic caps with internal thread). Due to the relatively greater hardness of the composition, it is less well suited for screwing crown caps.

In a preferred embodiment, the polymer composition according to the invention comprises a scavenger component, which particularly inhibits the ingress of oxygen.

Inorganic sulfites, such as sodium sulfite, are particularly suitable as scavengers. Other known scavengers, such as ascorbic acid, may also be used. Suitable scavenger materials are described, for example, in the same applicant's application WO 2011/069520, in terms of type, amount and application, which is incorporated herein by reference.

The invention further relates to a defined polymer composition of the above-mentioned type, which achieves an improved barrier effect without the addition of scavenger materials.

Some of the barrier compositions are based on rigid polyolefins, in particular HDPE (polyethylene) or PP (polypropylene) or co-PP (co-polypropylene) in combination with butyl rubber, without the addition of other polymers which reduce the hardness of the composition. Such a composition is described in example 1, wherein additionally a scavenger content is provided.

Such compositions are relatively hard. The composition is then particularly well suited when the seal made from the composition is used only once, for example in a "pry-off crown cap". For closures which are to be used several times, i.e. for example for reclosable containers, and in the case of non-flat and rough spout edges on the container, it is advantageous in contrast to this that the seal is softer and more flexible.

Such compositions, which comprise a polymer for softening, are better suited for such use purposes. The compositions are set forth in examples 2, 3 and 4 without regard to the scavenger content set forth herein.

The composition also exhibits excellent barrier action in the case of multiple use container closures and in the case of uneven, rough and damaged container spout.

The main object of the present invention is therefore to provide a sealing gasket suitable for the manufacture of container closures, which realises container closures provided with a polymer-based PVC-free sealing element having a barrier action, in particular in terms of oxygen and TCA, and preferably comprising an oxygen-scavenging constituent. An important object of the present invention is to provide a polymer composition suitable for use in the manufacture of such a sealing gasket.

The composition according to the invention should enable the production of container closures which, on the one hand, satisfy the requirements with regard to tightness and opening force and, on the other hand, can contain oxygen-scavenging constituents, but which, however, do not consist of or contain PVC.

In order to achieve said and other objects, the sealing gasket for screwing crowns according to the invention is provided with the features defined in the embodiments. Advantageous embodiments are defined in the following description.

The polymer compositions according to the invention show good barrier action against oxygen, TCA and other undesirable volatile materials.

The compositions are softer than comparable, commonly used compositions, which improves their sealing action. Preferably, the Shore D hardness is 20 or more, but not more than 55.

The melt flow index (MFI at 190 ℃ and 5kg) of the composition is preferably at least 5, preferably at least 10 and particularly preferably 13 or more. Particularly suitable compositions exhibit an MFI of more than 15, more than 20, and sometimes even more than 25, which has a particularly advantageous effect on processability.

The compositions according to the invention consist essentially of a substance mixture which comprises at least one, but preferably two or more different polymers and, if appropriate, further customary additives (antioxidants, lubricants, pigments, etc.), wherein scavenger material content is added to the substance mixture if appropriate.

The composition preferably comprises a non-crosslinked, (rubbery) barrier polymer. Polymers such as butyl rubber, polyisoprene, polyisobutylene, SIBS or polybutene can be used for this purpose.

In a preferred embodiment, the composition comprises HDPE in addition to L DPE and/or LL DPE, wherein in addition to L DPE is preferred a composition with HDPE content, and in some embodiments most preferred a composition that does not comprise LL DPE.

The composition can instead or additionally have a content of polypropylene (PP) and/or a copolymer of propylene and ethylene (co-PP).

In a particularly preferred embodiment, the relative total content of SIBS is above 5 wt.%, better above 10 wt.% and below 30 wt.%, the relative total content of polyolefin is generally at least 30 wt.%, preferably at least 50 wt.% and optionally at least 70 wt.% (always based on the total weight of the finished composition), preferably the SIBS-based composition has a shore D hardness of between 30 and 60, for example between 45 and 55.

Additionally or alternatively, the composition can comprise other polymers having elastomeric properties.

Particularly preferred are: ethylene Vinyl Acetate (EVA) content is added to the composition and when the composition has both ethylene octene block copolymer content then this is fully preferred. The VA content in the EVA is preferably in the range from 1% to 30%, generally between 5% and 25%.

According to the invention, the composition comprises substantially no oil (i.e. less than 10%, in particular less than 5%), preferably no oil at all, and also preferably no other (organic) constituents which are liquid at room temperature.

The composition according to the invention preferably comprises sodium sulfite as scavenger. The scavenger material content is typically about 1% to 10% by total weight of the composition.

Basically, it is possible to: the compositions according to the invention are prepared only from thermoplastic polymers (in particular HDPE) and butyl rubber with suitable hardness, wherein only scavengers and customary auxiliary materials (lubricants etc.) are added to both polymers. In a preferred embodiment, the polymer composition is composed of HDPE and butyl rubber, wherein the proportion of HDPE is greater than the proportion of rubber. Such compositions (in the context of the compositions according to the invention) are relatively hard and inelastic; the composition is particularly suitable for less demanding use purposes, such as for disposable bottles.

In contrast, for demanding purposes, especially for reclosable containers, compositions are preferred which are tailored to be softer and more elastic, which can be achieved by providing a base mixture of a hard polymer (e.g., HDPE) and butyl rubber with an addition of a soft polymer.

As already proposed, such a composition can also be used in seals having barrier functions against oxygen, TCA, etc., without scavenger content.

In the case of the container closure according to the invention, the sealing element is likewise formed as a gasket on the inner face of the container closure, as is also the case in the known crown caps or screw caps.

If the sealing element is formed as a disk on the inner surface of the container closure for known bottle closures (crown caps or the like), it can be advantageous according to the invention if the container closure is larger: instead, only one ring of polymer material is formed, which in the closed state of the container rests against the container wall in the region of the opening. Such annular sealing elements are known, and although PU materials are also used for the production of the above-mentioned sealing elements, they have hitherto only been produced from PVC and plasticizer-containing materials, as described in detail.

The method described in US 5,763,004, which is incorporated by reference in the present specification, can be used for this purpose.

In principle, the production method according to the invention is based on a container closure blank made of metal, which is optionally first pretreated on its inner side with a suitable primer. In the case of plastic container closures, this pretreatment is not necessary.

The blank thus pretreated is coated on the inside with a polymer material in the form of hot flow, which should form a seal. Extrusion molding, in which the sealing composition is at a temperature in the range between 100 ℃ and 260 ℃, is particularly suitable for this.

When the sealing gasket is to be designed as a disk, the extrusion molding can be carried out, for example, in the center of the inner surface of the blank. The dosing of the polymeric material for extrusion molding is carried out by stripping off a defined amount of the polymer composition at the nozzle.

Subsequently, the disk-shaped sealing element is formed from the extrusion-molded, still flowing material by means of a corresponding stamping (analogously to the known SACMI method).

The sealing element can be formed in a modified manner on the outside of the cover or cover blank by stamping of a suitable polymer material and subsequently introduced into the cover or blank. The method is also known for the forming of small closures as a shell by SACMI.

In the injection molding process, it is also possible to produce profiled disks or also ring structures which can subsequently be inserted into, for example, metal closure blanks.

Detailed Description

The embodiment of the invention comprises the following steps:

example 1:

example 2:

example 3:

example 4:

example 5:

example 6:

example 7:

example 8:

example 9:

example 10:

example 11:

example 12:

example 13:

OTR values (cm) set forth herein³/m²d) Measured by means of MOCOn OX-TRAN 2/60 at 25 ℃, 100% relative humidity and normalized with a film thickness of 100 μm.

HDPE 1 is an HDPE having an MFI of 30

HDPE 2 is an HDPE having an MFI of 2

Further embodiments of the invention, as far as they relate to the composition itself having barrier properties, follow from the above-mentioned examples 2 to 7 by omitting the scavenger material (sodium sulfite).

According to the invention, starting from a hot fill of at least 60 ℃ for at most 10min and at least 1min, the polymeric material can withstand a hot fill up to 100 ℃ for up to 60 min. Hot filling, starting from 60 ℃, can be increased to 100 ℃ in steps of 5 ℃ in 60 minutes.

Optionally, pigments, preferably inorganic pigments, can also be added to the formulation of the composition in order to exclude pigment migration. It is furthermore shown that further additives, such as waxes, silicones and in particular blowing agents, can be added to the polymer composition, for example in order to improve processing and application properties.

As can be seen from the above description, the embodiments of the present invention cover, but are not limited to, the following technical solutions:

scheme 1. a polymer composition for a PVC-free gasket for a seal of a container closure, said polymer composition being provided with at least one oxygen scavenging compound, characterized in that the polymer composition has a shore D hardness of at least 20 and the polymer composition has a melt flow index (190 ℃, 5kg) of at least 5.

Scheme 2. the polymer composition according to scheme 1, which is composed such that the composition comprises a (rubbery) barrier polymer such as: butyl rubber, polyisoprene, SIBS; or a combination of polybutene and polyolefin, but substantially no oil.

Scheme 3. the composition according to scheme 1 or 2, characterized in that it has a shore D hardness of 20 to 60 and particularly preferably of 40 to 50.

Scheme 4. the composition according to schemes 1 to 3, characterized in that it comprises sodium sulfite as oxygen scavenging compound, preferably sodium sulfite having an average particle size of less than 20 μm, more preferably having an average particle size of less than 12 μm and especially preferably having an average particle size of less than 7 μm.

Scheme 5. the composition according to schemes 1 to 4, characterized in that it comprises between 1% and 10% sodium sulfite, preferably 4% to 8% sodium sulfite, as oxygen scavenging compound.

Scheme 6. a polymer composition for a PVC-free seal gasket for a container closure, the polymer composition comprising at least one polyolefin and at least one (rubbery) barrier polymer according to scheme 2, but substantially no oil, wherein the polymer composition comprises at least one different further polymer which reduces the overall hardness (shore D hardness) of the composition compared to a corresponding composition not comprising the further polymer, wherein the shore D hardness of the composition comprising all of the polymers is at least 20 and the composition has a melt flow index (190 ℃, 5kg) of at least 5.

Scheme 7. the polymer composition according to any of the schemes 1 to 6, characterized in that the composition comprises up to 50%, more preferably up to 40%, especially preferred up to 25% and preferably at least 10%, more preferably at least 15% and especially preferred at least 20% of the (rubbery) barrier polymer according to claim 2.

Scheme 8. the polymer composition according to any of the schemes 1 to 7, characterized in that the composition comprises up to 80 wt. -%, more preferably up to 70%, especially preferably up to 60% and preferably at least 30%, more preferably at least 40% and especially preferably at least 50% HDPE.

Scheme 9. the composition according to schemes 1 to 8, characterized in that it comprises between 5% and 25% of low density polyethylene L DPE, preferably between 10% and 10% of L DPE.

Scheme 10. the composition according to schemes 1 to 9, characterized in that it comprises not more than 4% of lubricant and particularly preferably not more than 1% of lubricant.

Scheme 11. the composition according to schemes 1 to 10, characterized in that it comprises not more than 10% by weight of oil, preferably not more than 5% by weight of oil and particularly preferably does not comprise oil at all.

Scheme 12. the composition according to schemes 1 to 11, characterized in that it comprises up to 30% of linear low density polyethylene LL DPE, preferably up to 10% of LL DPE and especially preferably not more than 5% by weight of LL DPE.

Scheme 13. the composition according to any of schemes 1 to 12, characterized in that it comprises at least one block copolymer, wherein the block copolymer is preferably an interpolymer of ethylene with at least one C3-C10- α olefin or a copolymer of ethylene with a C3-C20- α olefin, optionally in combination with other unsaturated monomers, and preferably amounts to up to 25% by weight, more preferably up to 20% by weight and especially preferably between 5% and 15% by weight of the composition.

Scheme 14. the polymer composition according to any of the schemes 1 to 13, characterized in that the composition has an EVA content amounting preferably at least 5 wt. -%, more preferably at least 8 wt. -% and especially preferably at least 10 wt. -%, wherein the composition preferably also has a content of the block copolymer according to scheme 13.

Scheme 15. the composition according to any one of schemes 1 to 14, comprising additives such as waxes and silicones.

Scheme 16. a container closure seal gasket comprising the polymer composition according to any one of schemes 1 to 15.

Scheme 17. a container closure with a sealing gasket comprising the polymer composition of any of schemes 1 to 15.

Scheme 18. use of the polymer composition according to any of the schemes 1 to 15 for the manufacture of a seal gasket for a container closure, in particular a bottle closure or a sealing cap, especially a crown cap.