Container closure with sealing element

Abstract

Vessel closure (1, 21, 41, 61) with a sealing element (3, 23, 43, 63), wherein the sealing element (3, 23, 43, 63) comprises a polymer composition; the polymer composition comprising ... (a) between 5 wt.% and 50 wt.% of a first polymer, wherein the first polymer is a random copolymer having a Shore D hardness, measured according to DIN ISO 7619-1 at 23 °C, of ​​at least 35, and wherein 1-butene is a comonomer of the first polymer; (b) between 50 wt.% and 95 wt.% of a second polymer, wherein the second polymer is a polyolefin having a Shore A hardness, measured according to DIN ISO 7619-1 at 23 °C, of ​​not more than 90, in particular not more than 85, and wherein 1-butene is a comonomer of the second polymer; and (c) wherein the first polymer and the second polymer are different polymers.

Description

[0001] The invention relates to a container closure, for example a screw cap, with a sealing element.

[0002] PVC-free polymer compositions for sealing elements in vessel closures are known from the prior art. Known polymer compositions that do not contain PVC are relatively expensive and often exhibit significantly higher oxygen permeability values ​​compared to PVC-containing compositions.

[0003] High oxygen permeability values ​​are undesirable. A relatively high oxygen ingress into a filled and sealed container reduces the quality of the contents relatively quickly.

[0004] For example, compositions containing an oxygen scavenger (sodium sulfite) to reduce oxygen ingress into the filled and sealed container are known from WO 2015 / 010718. Sodium sulfite in compositions for sealing elements of container closures is often undesirable because this sulfite salt can leach into the contents and cause allergy-like reactions in consumers.

[0005] WO 2016 / 188 982 A1 relates to a seal for closures, consisting of a polyolefin composition (I) containing A) 25 to 62 wt% of a copolymer of butene-1 and ethylene with a copolymerization content of ethylene of up to 18 mol% and without a melting peak detectable by DSC on the second heating pass; B) 38 to 75 wt% of (i) a propylene homopolymer, or (ii) a propylene copolymer, or (iii) a mixture of two or more of (i) and (ii) with a melting temperature Tm, measured by DSC on the second heating pass, of 130 °C to 165 °C; wherein the amounts of A) and B) refer to the total weight of A) + B).

[0006] DE 10 2018 128 283 A1 relates to a sealing element made of a polymer composition in a vessel closure. The polymer composition is intended for use as a sealing element in a vessel closure and should be producible at acceptable costs and exhibit very low migration values. A vessel closure with a sealing element is proposed. The sealing element comprises a polymer composition. The polymer composition includes a butene copolymer. The butene copolymer has a melting point Tm between 30 °C and 130 °C, where the melting point Tm is determined by the second heating curve of a DSC measurement at a heating rate of 10 °C / min.

[0007] One object of the invention is to provide a polymer composition that can be used as a sealing element in a vessel closure, which has very low oxygen permeability values ​​and can be manufactured at acceptable costs.

[0008] The problem is solved by a vessel closure according to claim 1. Advantageous embodiments are specified in the dependent claims.

[0009] The vessel closure comprises a sealing element, the sealing element comprising a polymer composition; the polymer composition comprising (a) between 5 wt.% and 50 wt.% of a first polymer, wherein the first polymer is a random copolymer having a Shore D hardness, measured according to DIN ISO 7619-1 at 23 °C, of ​​at least 35, and wherein 1-butene is a comonomer of the first polymer; (b) between 50 wt.% and 95 wt.% of a second polymer, wherein the second polymer is a polyolefin having a Shore A hardness, measured according to DIN ISO 7619-1 at 23 °C, of ​​at most 90, in particular at most 85, and wherein 1-butene is a comonomer of the second polymer; and wherein the first polymer and the second polymer are different polymers. Typically, the vessel closure comprises a carrier made of metal, plastic, or metal and plastic (composite closure).The carrier of the vessel closure can be coated with an adhesive lacquer, particularly if the carrier is made of or incorporates metal. The polymer composition can be applied to the carrier, and the sealing element can then be formed onto it. Alternatively, the sealing element can be formed outside the carrier and subsequently inserted into the carrier, with the sealing element being bonded to the carrier by other means (e.g., pressure and temperature).

[0010] The sealing element can be essentially disc-shaped or essentially ring-shaped.

[0011] In classic vessel closures, e.g. cam rotary closures, the majority of the sealing element is formed in the flat area of ​​the carrier, so that an upper end of a vessel opening comes into contact with the sealing element when the vessel closure closes a vessel.

[0012] Particularly with press-on twist-off container closures (PT container closures), a significant portion of the sealing element can also be formed in the skirt area of ​​the carrier. With composite PT container closures, such as those sold under the brand name Band-Guard, a plastic thread of the container closure can interact with a mating thread of a container (e.g., a glass container with an external thread).

[0013] A PT vessel closure is pressed onto the vessel opening (press-on) while the sealing element is sufficiently fluid due to heating. An external thread in the vessel opening creates an internal thread (the negative of the external thread) in the sealing element area on the apron of the vessel closure carrier. This internal thread remains after the sealing element has hardened. The PT vessel closure is removed from the vessel by a twisting motion (twist-off).

[0014] A comonomer of the first polymer can be propene, so the first polymer can be a random-propene copolymer.

[0015] The comonomer content of propene in the first polymer can be greater than 50 mol%, preferably greater than 60 mol%. Specifically, the comonomer content of propene in the first polymer can be at least 70 mol%, preferably at least 80 mol%.

[0016] 1-Butene is a comonomer of the first polymer. In the random 1-butene copolymer, the comonomer content of 1-butene can be greater than 50 mol%, preferably greater than 60 mol%. The comonomer content of 1-butene in the first polymer can be at least 75 mol%, preferably at least 90 mol%.

[0017] Ethene can also be a comonomer of the first polymer as a random copolymer, so the first polymer can be a random ethene copolymer. The proportion of the ethene comonomer in the first polymer can be less than 50 mol%, in particular less than 40 mol% or even less than 30 mol%. Specifically, the proportion of ethene as a comonomer in the copolymer is at most 20 mol%, and in particular less than 10 mol%.

[0018] Similarly, 1-hexene or 1-octene can be a comonomer of the first polymer. The corresponding random 1-hexene copolymer or random 1-octene copolymer can contain 1-hexene or 1-octene as a comonomer in a proportion of less than 50 mol%.

[0019] Ethene as a comonomer of the first polymer can have a proportion of less than 50 mol%.

[0020] It is also preferred that the first polymer is a random 1-butene-ethene copolymer, wherein the 1-butene content in the copolymer is particularly preferably more than 50 mol% and the ethene content in the copolymer is less than 50 mol%. Specifically, the 1-butene comonomer content in the random 1-butene copolymer is at least 90 mol% and the ethene comonomer content in the copolymer is at most 10 mol%.

[0021] The first polymer can also be a random ethene copolymer, with propene or 1-butene being a comonomer of the first polymer.

[0022] The first polymer can be a bipolymer.

[0023] The density of the first polymer can be greater than 0.890 g / cm³ 3 It may be. In particular, the density of the first polymer can be between 0.890 g / cm³. 3 and 0.930 g / cm² 3 The density of the first polymer lies between 0.895 g / cm³. 3 and 0.920 g / cm² 3In one embodiment, the density of the first polymer can be between 0.890 g / cm³ 3 and 0.905 g / cm³ 3 The density can be determined according to DIN EN ISO 1883-1.

[0024] The density of the second polymer can be less than 0.890 g / cm³ 3 Specifically, the density of the second polymer is less than 0.880 g / cm³. 3 In particular, the second polymer exhibits a density between 0.890 g / cm³. 3 and 0.860 g / cm² 3 The density of the second polymer can also be between 0.880 g / cm³. 3 and 0.865 g / cm² 3 lay.

[0025] The mass flow index (MFI) of the second polymer can be less than 30 g / 10 min, specifically less than 10 g / 10 min, and most preferably less than 5 g / 10 min, where the MFI is determined according to DIN EN ISO 1133 at 190 °C and 2.16 kg. The MFI of the second polymer can be between 0.5 g / 10 min and 50 g / 10 min or between 0.5 g / 10 min and 3 g / 10 min.

[0026] The second polymer cannot have a melting temperature Tm, in particular not a melting temperature Tm between 40 °C and 125 °C. The melting temperature Tm can be determined by the second heating curve of a DSC measurement at a heating rate of 10 °C min. -1 be determined.

[0027] The MFI (DIN EN ISO 1133) of the first polymer at a temperature of 190 °C and a weight of 2.16 kg can be more than 500 g / 10 min, in particular more than 800 g / 10 min, and specifically more than 1000 g / 10 min. The MFI of the first polymer can be between 1000 g / 10 min and 1500 g / 10 min or between 1000 g / 10 min and 1400 g / 10 min.

[0028] The MFI (DIN EN ISO 1133) of the first polymer can be less than 50 g / 10 min, in particular less than 30 g / 10 min, and specifically less than 10 g / 10 min, at a temperature of 230 °C and a weight of 5.0 kg. The MFI of the first polymer can be between 4 g / 10 min and 10 g / 10 min.

[0029] In particular, the MFI of the first polymer at a temperature of 230 °C and a weight of 5.0 kg can be less than 75 g / 10 min, specifically less than 50 g / 10 min, preferably less than 30 g / 10 min. The MFI of the first polymer can be between 10 g / 10 min and 30 g / 10 min.

[0030] The first polymer can have a melting point Tm between 80 °C and 160 °C. The melting temperature T m The melting point (Tm) of the first polymer can be determined from the second heating curve of a DSC measurement at a heating rate of 10 °C / min. Specifically, the melting point Tm can lie between 100 °C and 160 °C.

[0031] The melting point T m The temperature of the first polymer can be between 80 °C and 140 °C, preferably between 90 °C and 110 °C.

[0032] The melting point T m The temperature of the first polymer can also be between 100 °C and 140 °C, specifically between 110 °C and 140 °C, and particularly preferably between 125 °C and 140 °C.

[0033] In one embodiment, the melting point T m of the first polymer between 120 °C and 160 °C, specifically between 140 °C and 160 °C, particularly preferably between 145 °C and 160 °C.

[0034] The first polymer can have a Shore D hardness (DIN ISO 7619-1, 23°C, 15 s) between 40 and 80. Preferably, the Shore D hardness of the first polymer is between 50 and 70, especially between 57 and 67.

[0035] The second polymer is a copolymer, specifically a polyolefin copolymer. More precisely, the second polymer is a random copolymer, or random polyolefin copolymer.

[0036] 1-Butene is a comonomer of the second polymer. Ethene can be a comonomer of the second polymer.

[0037] Specifically, the second polymer is a 1-butene-ethene copolymer, preferably a random 1-butene-ethene copolymer.

[0038] The comonomer content of 1-butene in the second polymer can be greater than 50 mol%. Preferably, the comonomer content of 1-butene in the second polymer is at least 60 mol% or even at least 80 mol%.

[0039] The Shore A hardness (DIN ISO 7619-1, 23°C, 15 s) of the second polymer can range between 30 and 85. Preferably, the Shore A hardness of the second polymer is between 40 and 80, particularly preferably between 50 and 70, and especially between 55 and 65.

[0040] The first polymer can be present in the polymer composition in a concentration of between 10 wt.% and 40 wt.%. Alternatively, the first polymer can be present in the polymer composition in a concentration of between 15 wt.% and 35 wt.%, preferably between 20 wt.% and 30 wt.%.

[0041] The polymer composition contains, in particular, between 55 wt.% and 85 wt.% of the second polymer. Preferably, the content of the second polymer in the polymer composition is between 60 wt.% and 80 wt.%, especially between 65 wt.% and 75 wt.%.

[0042] Weight percentages of components in the polymer composition refer to the total weight of all components in the polymer composition.

[0043] The polymer composition may contain other polymeric components besides the first and second polymers.

[0044] The polymer composition can also consist of only the first polymer and the second polymer as polymeric components, with the possibility of additional additives.

[0045] The polymer composition can be a polyolefin composition, meaning that the polymer composition consists exclusively of polyolefins as polymeric components, while additives may be included as non-polyolefins in the polymer composition.

[0046] It is preferred that the polymer composition contains a maximum of 10 wt% of components that are liquid at 20 °C and 1000 hPa. Specifically, the polymer composition contains a maximum of 5 wt% of such a component, and specifically, the polymer composition is free of any component that is liquid at 20 °C and 1000 hPa, to the extent analytically possible on the filing or priority date.

[0047] The polymer composition can be free of PVC (polyvinyl chloride).

[0048] In one embodiment, the polymer composition can be free of a copolymer that includes styrene as a comonomer.

[0049] The polymer composition can also be free of homo-polypropylene.

[0050] The polymer composition may contain up to 15 wt% additives. In particular, the polymer composition contains up to 8 wt% additives, and preferably a maximum of 6 wt% additives.

[0051] Additives in the polymer composition may be selected from the group consisting of: pigments, nucleating agents, brighteners, stabilizers, surfactants, lubricants, antioxidants and combinations thereof.

[0052] It is preferred that the polymer composition does not contain an oxygen scavenger.

[0053] The polymer composition can have a static coefficient of friction (determined according to DIN EN ISO 8295) of a maximum of 0.50, and in particular a static coefficient of friction of a maximum of 0.40. Specifically, the static coefficient of friction of the polymer composition lies between 0.30 and 0.40 or between 0.20 and 0.32.

[0054] The oxygen permeability rate of the polymer composition can be less than 600 cm. 3 m -2 d -1 bear -1 , preferably less than 500 cm 3 m -2 d -1 bear -1 , preferably less than 450 cm 3 m -2 d -1 bear -1 to be, specifically a maximum of 400 cm 3 m -2 d -1 bear -1 The oxygen permeability rate of the polymer composition is particularly preferably between 300 cm. 3 m -2 d -1 bear -1 and 400 cm 3 m -2d -1 bear -1 or between 320 cm 3 m -2 d -1 bear -1 and 500 cm 3 m -2 d -1 bear -1 .

[0055] The oxygen permeability rate can be measured according to DIN 53380. The oxygen permeability rate of the polymer composition in the container closure influences the possible storage time of a container sealed with this closure and filled with food.

[0056] The total migration of the polymer composition can be a maximum of 1.20 mg / cm³. -2 , preferably a maximum of 1.00 mg cm -2 , particularly preferably a maximum of 0.80 mg cm -2 , preferably a maximum of 0.75 mg cm -2 The total migration of the polymer composition can be determined according to DIN EN 1186-14. In particular, the total migration of the polymer composition is between 0.50 mg / cm³. -2 and 0.80 mg cm -2or between 0.80 mg cm -2 and 1.10 mg cm -2 .

[0057] If a filled container is sealed by a container closure with a sealing element made of the polymer composition and has a surface area / mass ratio of 1 cm² -2 With a contact area of ​​the sealing element to 0.02 kg mass of the contents in the container, a total migration limit of 60 mg / kg is achieved. -1 complied.

[0058] It is preferred if the sealing element of the vessel closure consists of the polymer composition, i.e., if the sealing element does not include an additional applied film.

[0059] Different polymers in the polymer composition can differ in their physical properties (e.g., density, melting point, hardness, etc.). Copolymers can also differ in their structure (block copolymer, random copolymer, etc.). Furthermore, copolymers can differ in the type of comonomers they contain (ethene, propene, etc.).

[0060] The vessel closure can comprise a carrier and the sealing element. The carrier can include a flat section and a skirt section. Specifically, the carrier can be made of metal, plastic, or a combination of metal and plastic. In particular, the main component of the carrier is metal or plastic, especially metal.

[0061] The container closure can be a screw cap. Preferably, the container closure is a cam-type twist-off cap. The container closure can also be a press-on twist-off cap or a composite cap.

[0062] A disclosed vessel closure can close a vessel. The vessel comprises a vessel mouth and a closable opening at the end of the vessel mouth. This opening closes one of the disclosed vessel closures.

[0063] The container can be a glass container, a plastic container, or a metal container. Specifically, the container is a glass container.

[0064] The vessel closure, which seals the vessel opening, can comprise a support and a sealing element. The support can have a lower side, and the vessel opening can have an upper end. The sealing element of the vessel closure is typically clamped between the vessel opening and the support of the closure, so that the sealing element rests against both the upper end of the vessel opening and the lower side of the support. Specifically, the height of the sealing element between the upper end of the vessel opening and the lower side of the support is a maximum of 1.0 mm. Preferably, this height is a maximum of 0.8 mm, and particularly preferably a maximum of 0.7 mm. The height can be determined in the axial direction of the vessel.

[0065] Similarly, the height of the sealing element between the upper end of the vessel opening and the lower side of the support can be at least 0.2 mm. Specifically, the height is at least 0.4 mm and particularly preferably at least 0.5 mm. The height of the sealing element can be measured in the axial direction of the vessel.

[0066] The height of the sealing element between the upper end of the vessel opening and the lower side of the support is particularly preferred to be between 0.3 mm and 0.9 mm.

[0067] For example, if the height of the sealing element before the vessel closure is applied to a vessel is 1.2 mm, an indentation of the upper end of the vessel opening into the sealing element (height between the upper end of the vessel opening and the lower side of the support of a maximum of 1.0 mm) without cutting through the sealing element (height of the sealing element between the upper end of the vessel opening and the lower side of the support of at least 0.2 mm) ensures a high tightness of the vessel closed with the vessel closure.

[0068] Preferably, a vacuum is maintained in the closed container. The absolute pressure in the closed container can be a maximum of 200 hPa. Specifically, the absolute pressure in the sealed container is a maximum of 100 hPa.

[0069] The container sealed with the closure can have a maximum safety dimension of 10 mm; specifically, the maximum safety dimension is 8 mm. Preferably, the maximum safety dimension is 6 mm. Most preferably, the maximum safety dimension is 4 mm.

[0070] To determine the safety margin, a container sealed with a cam-type screw cap is stored at room temperature (23°C) for 30 minutes. The relative position of the cap to the container is marked by placing a mark on both the cap's apron and the container wall, ensuring that the distance between the mark on the apron and the container wall is zero. The marks lie on a straight line parallel to the container's longitudinal axis. The cap is then completely removed from the container by unscrewing it. Next, the cap is placed onto the container and tightened until slight resistance is felt. The cap is then tightened finger-tight. Finally, the distance between the mark on the cap and the mark on the container wall is measured. This measured distance corresponds to the safety margin, expressed in millimeters.

[0071] Due to the steep pitch of the threads on containers and cam-type screw caps, at least in some sections, the precision of measuring the safety dimension is high, as the point at which slight resistance is felt while tightening the container cap (finger-tight) can be precisely determined. Typically, the precision of measuring the safety dimension on sealed containers closed under identical conditions by different individuals is approximately ±1 mm.

[0072] A suitable safety margin ensures that the sealing element exerts an elastic force on at least the upper end of the vessel opening when the vessel is closed with the closure. This results in a high degree of tightness of the interior of the closed vessel.

[0073] A sealed and filled container can be produced by providing a container with a mouth and a closable opening at the end of the mouth. The container is filled with a (solid and / or liquid) foodstuff through the opening, and the opening is sealed with a disclosed container closure.

[0074] The opening of the vessel can have a diameter of at least 20 mm. In particular, the diameter of the opening of the vessel is a maximum of 120 mm.

[0075] The container can be a glass container, a plastic container, or a metal container.

[0076] The vessel closure can be treated at a temperature of at least 90 °C before the vessel opening is sealed with the closure. Such treatment can be carried out, for example, with steam.

[0077] A headspace can form in the container after it has been filled with food. This headspace is the portion of the container's contents that is empty. Steam can be introduced into this headspace before the container's closure is applied, thus sealing the opening. This steam can be, in particular, water vapor.

[0078] The absolute pressure inside the sealed and filled container can be a maximum of 200 hPa. Specifically, the pressure inside the sealed and filled container can be a maximum of 100 hPa.

[0079] To create an impression of the vessel opening in the sealing element, the sealing element can be deformed by at least 0.2 mm in the axial direction of the vessel during the closing of the vessel opening with the vessel closure and / or during thermal treatment of the closed and filled vessel. Preferably, this deformation of the sealing element is at least 0.4 mm. Specifically, the deformation is at least 0.5 mm.

[0080] Similarly, the sealing element can be deformed by a maximum of 1.0 mm to form an impression of the vessel opening into the sealing element during the closing of the vessel opening with the vessel closure and / or during thermal treatment of the closed and filled vessel. In particular, the deformation is a maximum of 0.8 mm. Preferably, the deformation is a maximum of 0.7 mm. This applies in each case in the axial direction of the vessel.

[0081] The deformation of the sealing element is particularly preferred to be between 0.3 mm and 0.9 mm.

[0082] The food can be aseptically filled into the container.

[0083] The food can also be placed in the container at a temperature of no more than 10 °C.

[0084] The food can also be placed in the container at a temperature between 10 °C and 70 °C.

[0085] The food can also be placed in the container at a temperature between 70 °C and 98 °C.

[0086] Within the process, the sealed and filled container can be thermally treated. The temperature of the thermal treatment is higher than the temperature of the (solid and / or liquid) foodstuff during the filling of the container.

[0087] The thermal treatment can be carried out at a temperature of at least 60°C.

[0088] The thermal treatment can also be carried out at a temperature of up to 135°C (between 60°C and 135°C). In particular, the thermal treatment is carried out at a temperature of up to 135°C (between 60°C and 135°C) at an absolute ambient pressure of up to 4.0 bar, preferably at an absolute ambient pressure between 1.0 bar and 4.0 bar.

[0089] Preferably, the pressure inside the sealed vessel during thermal treatment is lower than the pressure outside the sealed vessel.

[0090] The embodiments of the invention are illustrated by means of an example and not in a way that transfers or reads into the claims any limitations from the figures. Identical reference numerals in the figures denote identical elements. Fig. Figure 1 shows a side view of a cam rotary closure 1 with an annular sealing element 3, partially as a section; Fig.Figure 2 shows a side view of the cam rotary closure 1 with the sealing element 3 on a vessel 5, partially as a section; Fig. Figure 3 shows the cam rotary lock 1 with the sealing element 3 in a bottom view; Fig. Figure 4 shows an isometric view of a composite shutter 61 (Combi-Twist); Fig. Figure 5 shows a partial axial section of the composite closure 61 (Combi-Twist) of Fig. 4; Fig. Figure 6 shows a side view of a press-on twist-off closure 21 (PT closure) with a sealing element 23, partially as a section; Fig. Figure 7 shows a side view of the PT closure 21 with the sealing element 23 on a vessel 25, partly as a section; Fig. Figure 8 shows a top view of the PT shutter 21; Fig. Figure 9 shows a side view of a composite closure 41 (Band-Guard) with a sealing element 43, partially as a section; Fig. Figure 10 shows a side view of the composite closure 41 (Band-Guard) with the sealing element 43 on a vessel 45, partially as a section; Fig. Figure 11 shows a top view of the composite closure 41 (Band-Guard); Fig. Figure 12 shows an enlarged section of the cam rotary lock of Fig. 2.

[0091] The Fig. 1 and Fig. Figure 3 shows a cam-type rotary closure 1. The cam-type rotary closure 1 comprises a metallic carrier 11 and a sealing element 3. In the illustration of the Fig. 2. The cam-type rotary closure 1 is applied to a vessel 5. A rolled section 9 is formed at the lower end of the cam-type rotary closure 1. Several cams 7 are formed circumferentially distributed from the rolled section 9. The cams 7 are formed by an axial deformation of the rolled section 9 and extend radially further towards the center of the cam-type rotary closure 1 than the rolled section 9. The Fig. 1 to Fig. The cam-type rotary fastener 1 shown in Figure 3 comprises four cams 7, which are uniformly distributed around their circumference. The cuts that are in the Fig. 1 and Fig. 2, which are partially depicted, correspond to section III-III in Fig. 3.

[0092] Near the radially outer end section of the cam-type rotary closure 1, a channel 2 is formed in the upper section 10 of the carrier 11. The sealing element 3 is arranged at least partially in the channel 2. In this embodiment, the sealing element 3 is annular in shape; in other embodiments, the sealing element 3 can be disc-shaped, particularly if the diameter of the cam-type rotary closure is small (e.g., a maximum of 30 mm).

[0093] To promote adhesion between the metallic support 11 and the sealing element 3, an adhesive lacquer is typically applied to the side of the metallic support 11 that is in contact with the sealing element 3.

[0094] In Fig. 2 The cam-type rotary closure 1 is mounted on a vessel 5. The vessel 5 includes a vessel opening 5a as its upper section. The vessel opening comprises a thread 6 and an upper end 4 of the vessel opening 5a. The thread 6 is formed circumferentially in the area of ​​the vessel opening 5a and extends circumferentially upwards or downwards (depending on the viewing angle).

[0095] To attach the cam-type rotary closure 1 to a vessel 5, cams 7 are brought into contact with sections of the thread 6, and the cam-type rotary closure 1 is rotated clockwise relative to the vessel 5. Due to the design of the thread 6 and the interaction of the cams 7 with the thread 6, the upper end 4 of the vessel opening 5a moves towards the sealing element 3 during the rotation of the cam-type rotary closure 1 relative to the vessel 5. With a further rotation of the cam-type rotary closure 1, the upper end 4 of the vessel opening 5a presses into the sealing element 3 and deforms it, so that a section of the upper end 4 of the vessel opening 5a is covered by the sealing element 3, thus tightly sealing the vessel 5.A tight seal of the vessel 5 is particularly necessary to withstand increased pressure during thermal treatment of the sealed vessel 5 at temperatures above 70 °C, 90 °C or even above 120 °C.

[0096] The cam rotary lock 1, as in the Fig. 1 to Fig. Figure 3 shows a safety button 10b formed in the upper section 10 of the carrier 11. Due to the slope 10a in the upper section 10 of the carrier 11, the safety button 10b folds towards the center of the vessel when a sufficiently large vacuum is present in the vessel. Such a vacuum can be created by introducing water vapor into the vessel before closing it with the closure.

[0097] When a consumer opens the container by removing the cap, the pressure inside rises to ambient pressure and the Safety Button 10b flips away from the center of the container. The flipping of the Safety Button 10b is accompanied by a characteristic sound, which indicates to the consumer that a vacuum existed inside the container before it was opened.

[0098] The Fig. 4 and Fig. Figure 5 shows a composite closure 61 (Combi-Twist) which, analogous to the described cam rotary closure 1, can be applied to a vessel by a rotary movement and can be removed from the vessel by a rotary movement.

[0099] The composite closure 61 comprises a carrier with an upper metallic section 71 and an L-shaped plastic section 72. Near the radial end of the metallic section 71 of the carrier, a channel 78 is formed, and a rolling element 77 is formed at the radial end of the metallic section 71. A sealing element is arranged at least partially in the channel 78.

[0100] Several threaded elements 74a, 74b formed on the inside of the plastic section 72 contact a mating thread in the area of ​​the mouth of a vessel (not shown) onto which the composite closure 61 is to be applied. The plastic section 72 of the composite closure 61 further includes a tamper-evident feature 73, similar to the tamper-evident feature as in the Fig. 9 to Fig. 11 is designed and with a view to the Fig. 9 to Fig. 11 is described in more detail.

[0101] When the composite closure 61 is screwed onto a vessel by a rotary movement, an analogous interaction of the vessel opening of the vessel with the sealing element of the composite closure 61 results as described using the cam rotary closure 1.

[0102] In the Fig. 6 to Fig. Figure 8 shows a press-on twist-off closure 21 (PT closure). The PT closure 21 comprises a metallic carrier 31 with a curl 29 at the lower end of the carrier 31 and a safety button 30a in the upper section 30 of the carrier 31.

[0103] A sealing element 23 is formed both in the area of ​​the upper section 30 of the carrier 31 and to a considerable extent on the skirt of the carrier, which extends downwards from the upper section 30 of the carrier 31. In contrast to the cam-type rotary closure 1 and the composite closure 61, the PT closure 21 is pressed onto the vessel opening 25a when it is applied to a vessel 25. During this pressing process, the sealing element 23 is sufficiently soft to elastically enclose the threaded elements 26 of the vessel opening 25a. Typically, the sealing element 23 is treated with steam before the PT closure 21 is applied to a vessel 5 to achieve the necessary softness. After cooling of the sealing element 23, a mating thread in the form of a negative of the thread elements 26 of the vessel opening is formed in the sealing element 23.

[0104] An upper end 24 of the vessel opening 25a contacts the sealing element 23.

[0105] To open the vessel 25, the PT closure 21 is removed from the vessel 25 by a twisting motion.

[0106] Fig. 9 to Fig. Figure 11 shows a composite shutter 41 (Band-Guard) which is functional analogous to the described PT shutter 21.

[0107] The composite closure 41 comprises a carrier with a metallic section 51 and a plastic section 52, a tamper-evident seal 53, and a safety button 50a. The tamper-evident seal 53 is designed to be removed from the rest of the composite closure 41 when the composite closure 41 is removed from a container 45, and serves to allow a consumer to verify whether the composite closure 41 has already been removed from the container 45. The safety button 50a is designed and functionally equivalent to the safety button 10b of the cam-type rotary closure 1.

[0108] The plastic section of the composite closure 41 can include several axially extending indentations 56 to increase the stability of the closure.

[0109] A sealing element 43 is arranged in the composite closure 41 such that it contacts both the metallic section 51 and the plastic section 52. To close a vessel 45, the composite closure 41 is pressed onto the vessel opening 45a of the vessel 45, so that at least the upper end 44 of the vessel opening 45a contacts the sealing element 43.

[0110] The plastic section 52 of the carrier includes several offset projections 54 that interact with threaded elements 46 of the vessel opening 45a. To open a vessel 45 that is closed with the composite closure 41, the composite closure 41 can be rotated relative to the vessel 45.

[0111] The distance h3 of a sealing element 3 between an upper end 4 of a vessel opening 5a of a vessel 5 and the lower side of a support 11 of the closure 1 is in Fig.Figure 12 shows and describes a cam-type rotary closure 1. The distance (height) h3 can be determined analogously for other closure types.

[0112] The sealing element 3, clamped between the vessel opening 5 and the support 11 of the vessel closure 1, has a height h3 that is determined when a vessel 5 is closed with the closure 1. If the height h3 is too small, the sealing element 3 may be cut, which could impair the tightness of the closed vessel 5. If the height h3 is too large, the tightness of the closed vessel is also compromised because the contact area between the upper end 4 of the vessel opening 5a and the sealing element 3 is insufficient. The composition of the sealing element 3 is crucial for achieving a proper impression of the upper end 4 of the vessel opening 5a into the sealing element. Examples:

[0113] Examples of polymer compositions for sealing elements in a vessel closure are shown in Table 1. Examples 1 and 2 are not examples of the invention. Table 1 Example 1 Example 2 Example 3 component random-1-Butene-Ethene Copolymer A, wt% 71,9 71,9 71,9 random propene-ethene copolymer, wt% 24,0 random-propen-1-hexene copolymer, wt% 24,0 random-1-Butene-Ethene Copolymer B, wt% 24,0 Additives, wt.% 4,1 4,1 4,1 Characteristics Coefficient of friction, dimensionless 0,30 0,24 0,26 Total migration, mg cm -2 1,0 0,9 0,9 Oxygen permeability rate, cm 3 m -2 d -1 bear -1 479 478 356

[0114] Random 1-butene-ethene copolymer A is an example of a second polymer in the polymer composition. Random 1-butene-ethene copolymer has a Shore A hardness (23 °C, 15 s) of 60, an MFI (190 °C, 2.16 kg) of 1.3 g / 10 min, and a density of 0.870 g / cm³. 3 The random-1-butene-ethene copolymer A does not exhibit a melting point, therefore the random-1-butene-ethene copolymer A does not possess a melting temperature Tm, which can be determined by the second heating curve of a DSC measurement at a heating rate of 10 °C min. -1 can be determined.

[0115] The random propene-ethene copolymer has a Shore D hardness (23 °C, 15 s) of 58, an MFI (190 °C, 2.16 kg) of 7 g / 10 min and a density of 0.900 g / cm³ 3The melting temperature Tm of the random propene-ethene copolymer is 135 °C.

[0116] The random propene-1-hexene copolymer has a Shore D hardness (23 °C, 15 s) of 62, an MFI (230 °C, 5.0 kg) of 20 g / 10 min and a density of 0.900 g / cm³ 3 The random propen-1-hexene copolymer has a melting temperature Tm of 153 °C.

[0117] Random 1-butene-ethene copolymer B is an example of a first polymer in the polymer composition. Random 1-butene-ethene copolymer has a Shore D hardness (23 °C, 15 s) of 62, a melt flow index (MFI) (190 °C, 2.16 kg) of 1200 g / 10 min, and a density of 0.910 g / cm³. 3 The melting temperature Tm of random-1-butene-ethene copolymer B is 103 °C.

[0118] The physical properties of the examples for the first polymer and the second polymer are determined according to the standards specified above.

[0119] Random 1-butene-ethene copolymer A and random 1-butene-ethene copolymer B may differ in their physical properties. For example, the MFI (190 °C, 2.16 kg or 230 °C, 5.0 kg) of random 1-butene-ethene copolymer A may be lower than the MFI of random 1-butene-ethene copolymer B, the density of random 1-butene-ethene copolymer A may be lower than the density of random 1-butene-ethene copolymer B, and / or the hardness (Shore A or Shore D) of random 1-butene-ethene copolymer A may be lower than the hardness of random 1-butene-ethene copolymer B.

[0120] Random 1-butene-ethene copolymer A can also differ from random 1-butene-ethene copolymer B in their comonomer content. The comonomer content of ethene in random 1-butene-ethene copolymer A can be higher or lower than the comonomer content of ethene in random 1-butene-ethene copolymer B, and / or the comonomer content of 1-butene in random 1-butene-ethene copolymer A can be lower or higher than the comonomer content of 1-butene in random 1-butene-ethene copolymer B.

Claims

[1] Vessel closure (1, 21, 41, 61) with a sealing element (3, 23, 43, 63), wherein the sealing element (3, 23, 43, 63) comprises a polymer composition; the polymer composition comprising ... (a) between 5 wt.% and 50 wt.% of a first polymer, wherein the first polymer is a random copolymer having a Shore D hardness, measured according to DIN ISO 7619-1 at 23 °C, of ​​at least 35, and wherein 1-butene is a comonomer of the first polymer; (b) between 50 wt.% and 95 wt.% of a second polymer, wherein the second polymer is a polyolefin having a Shore A hardness, measured according to DIN ISO 7619-1 at 23 °C, of ​​not more than 90, in particular not more than 85, and wherein 1-butene is a comonomer of the second polymer; and (c) wherein the first polymer and the second polymer are different polymers. [2] Vessel closure according to claim 1, wherein the comonomer content of 1-butene in the first polymer is more than 50 mol%. [3] Vessel closure according to claim 1 or 2, wherein the first polymer is a random-1-butene-ethene copolymer. [4] Vessel closure according to any one of claims 1 to 3, wherein the first polymer has a density of at least 0.890 g cm⁻¹ -3 exhibits, in particular more than 0.890 g cm -3 exhibits, and / or the second polymer has a density of less than 0.890 g cm⁻¹ -3 , especially less than 0.880 g cm -3 , exhibits. [5] Vessel closure according to any one of claims 1 to 4, wherein the first polymer has a melting point T m between 80 °C and 160 °C, with the melting temperature T m through the second heating curve of a DSC measurement at a heating rate of 10 °C min -1 is determined. [6] Vessel closure according to any one of claims 1 to 5, wherein the first polymer has a Shore D hardness, measured according to DIN ISO 7619-1 at 23 °C, between 40 and 80, preferably between 50 and 70, particularly preferably between 57 and 67. [7] Vessel closure according to any one of claims 1 to 6, wherein the second polymer is a random copolymer. [8] Vessel closure according to any one of claims 1 to 7, wherein the second polymer is a random-1-butene-ethene copolymer. [9] Vessel closure according to any one of claims 1 to 8, wherein the comonomer content of 1-butene in the second polymer is more than 50 mol%, preferably at least 60 mol%, particularly preferably at least 80 mol%. [10] Vessel closure according to any one of claims 1 to 9, wherein the second polymer has a Shore A hardness, measured according to DIN ISO 7619-1 at 23 °C, between 30 and 85, preferably between 40 and 80, particularly preferably between 50 and 70, more preferably between 55 and 65. [11] Vessel closure according to any one of claims 1 to 10, wherein the first polymer is contained in the polymer composition in a quantity between 10 wt.% and 40 wt.%, preferably between 15 wt.% and 35 wt.%, particularly preferably between 20 wt.% and 30 wt.%. [12] Vessel closure according to one of claims 1 to 11, wherein the second polymer is contained in the polymer composition in a quantity between 55 wt.% and 85 wt.%, preferably between 60 wt.% and 80 wt.%, particularly preferably between 65 wt.% and 75 wt.%. [13] Vessel closure according to one of claims 1 to 12, wherein the polymer composition comprises a maximum of 10 wt.%, preferably a maximum of 5 wt.%, of a component that is liquid at 20 °C and 1000 hPa, and particularly preferably the polymer composition does not comprise a component that is liquid at 20 °C and 1000 hPa. [14] Vessel closure according to any one of claims 1 to 13, wherein the polymer composition is a polyolefin composition. [15] Vessel closure according to any one of claims 1 to 14, wherein the polymer composition comprises up to 15 wt.%, preferably up to 8 wt.%, particularly preferably up to 6 wt.%, additives. [16] Vessel closure according to claim 15, wherein the additives are selected from the group consisting of: pigments, nucleating agents, brighteners, stabilizers, surfactants, lubricants, antioxidants and combinations thereof. [17] Vessel closure according to any one of claims 1 to 16, wherein the vessel closure comprises a support (11, 31, 51, 71) and the sealing element (3, 23, 43, 63), wherein the support (11, 31, 51, 71) comprises metal and / or plastic, in particular comprising metal or plastic as the main component. [18] Vessel closure according to any one of claims 1 to 17, wherein the vessel closure (1, 21, 41, 61) is a screw closure, in particular a cam-type rotary closure (1), a press-on twist-off closure (21) or a composite closure (41, 61). [19] Vessel closure according to any one of claims 1 to 18, wherein the polymer composition has an oxygen permeability rate, determined according to DIN 53380, of less than 600 cm 3 m -2 d -1 bear -1 , preferably less than 500 cm 3 m -2 d -1 bear -1 , preferably less than 400 cm 3 m -2 d -1 bear -1 , exhibits. [20] Vessel closure according to any one of claims 1 to 19, wherein the polymer composition has a total migration, determined according to DIN EN 1186-14, of a maximum of 1.20 mg cm⁻¹ -2 , preferably of a maximum of 1.0 mg cm -2 , particularly preferably of a maximum of 0.8 mg cm -2 , exhibits. [21] Vessel closure according to any one of claims 1 to 20, wherein the polymer composition has a static coefficient of friction, determined according to DIN EN ISO 8295, of a maximum of 0.50, preferably of a maximum of 0.40, particularly preferably of a maximum of 0.30.

Images