Vessel closure with sealing element

Description

[0001] The invention relates to a vessel closure, for example a screw cap, with a sealing element. The invention also relates to a vessel that is closed with such a vessel closure or that is filled and closed in a process to produce a closed and filled vessel.

[0002] Prior art PVC-free sealing elements for vessel closures often contain white oil as a component, which is liquid at ambient conditions. White oil is used in the compositions of the sealing elements to reduce their hardness, improve their processability, and reduce the overall cost of the sealing element.

[0003] If the sealing element of a container closure contains white oil and the closure seals a container filled with food, the overall migration into the food is increased. In particular, the overall migration is significantly increased if the food has a high fat or oil content.

[0004] US 2005 / 148720 A1 concerns radiation-resistant plasticized polyolefin compositions containing a polyolefin and a non-functionalized hydrocarbon plasticizer.

[0005] US 2006 / 189744 A1 concerns articles made from plasticized thermoplastic polyolefin compositions containing a thermoplastic polyolefin, a nucleating agent, and a non-functionalized hydrocarbon plasticizer.

[0006] WO 2006 / 128646 A2 concerns elastomeric structures with a first and a second element, each consisting of a different elastomeric material, the first element containing a modifier. The shaped structure could, for example, be a car weather seal.

[0007] WO 2016 / 188982 A1 relates to a seal for closures comprising a polyolefin composition (I) containing A) 25 to 62 wt% of a copolymer of butene-1 with ethylene having a copolymerized ethylene content of up to 18 mol% and no melting peak detectable by DSC on the second heating scan; 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) having a melting temperature Tm, as measured by DSC on the second heating scan, of 130°C to 165°C; wherein the amounts of A) and B) are based on the total weight of A) + B).

[0008] One object of the invention is to provide a polymer composition that can be used as a sealing element in a vessel closure, exhibits relatively low migration values, and enables the vessel closure to be used at low temperatures. A further object is to improve the processability of the polymer composition for use as a sealing element.

[0009] The problem is solved by the subject matter of the independent claims. Preferred embodiments are defined in the dependent claims.

[0010] The vessel closure includes a sealing element. The sealing element comprises a polymer composition, or consists of a polymer composition comprising a polyalphaolefin and a second polyolefin. The polyalphaolefin (first polyolefin) has a kinematic viscosity of at least 4 cSt at a temperature of 100°C. The kinematic viscosity can be determined according to ASTM D 445 or ISO 3104, preferably according to ISO 3104. Additionally or alternatively, the polyalphaolefin has a dropping point of at most -10°C. The dropping point can be determined according to ASTM 5950. The second polyolefin is present in the polymer composition at a proportion of up to 95 wt%.

[0011] The second polyolefin can be present in the polymer composition in a quantity between 5 wt.% and 95 wt.%, preferably between 15 wt.% and 85 wt.%, more preferably between 25 wt.% and 75 wt.%, and even more preferably between 35 wt.% and 65 wt.%.

[0012] The container closure can comprise a carrier made of metal, plastic, or a combination of metal and plastic, with a metal and plastic closure also being called a composite closure. If the carrier is made of metal, at least one side of the carrier can be coated with an adhesive lacquer to improve the bond between the sealing element and the carrier. The sealing element can be formed outside the carrier and bonded to the carrier, for example, by pressure and / or temperature. Alternatively, the sealing element can be formed on the carrier by applying a flowable polymer composition to the carrier and shaping it.

[0013] In the case of vessel closures that are applied to the opening of a vessel by a screwing motion, e.g. cam rotary closures, the sealing element is mostly arranged in the flat part of the carrier, so that an upper area of ​​a vessel mouth, by which the vessel opening is defined, contacts the sealing element when the vessel closure is attached to the vessel and closes the opening of the vessel.

[0014] The sealing element can be essentially disc-shaped or essentially ring-shaped.

[0015] Specifically with press-on twist-off container closures (PT container closures), a significant portion of the sealing element is located in the skirt area of ​​the carrier. In composite PT container closures (e.g., the container closure available under the brand name Band-Guard), the closure includes a plastic thread that engages with a mating thread on the container.

[0016] A PT vessel closure is pressed onto the vessel opening (press-on) while the sealing element is heated and sufficiently fluid. 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 holder. The internal thread remains after the sealing element has hardened. The PT vessel closure is removed from the vessel by a twisting motion.

[0017] The polyalphaolefin of the sealing element of the vessel closure can exist in liquid form (in the liquid state of matter) at 23 °C and 1 bar.

[0018] The kinematic viscosity of the polyalphaolefin can range from 4 cSt to 1500 cSt at a temperature of 100 °C. Specifically, the kinematic viscosity of the polyalphaolefin at a temperature of 100 °C is between 50 cSt and 1000 cSt or between 120 cSt and 1000 cSt. Most preferably, the kinematic viscosity of the polyalphaolefin at a temperature of 100 °C is between 250 cSt and 1000 cSt. The kinematic viscosity of the polyalphaolefin at 100 °C can also be at least 250 cSt. The kinematic viscosity of the polyalphaolefin at a temperature of 100 °C can be at most 1500 cSt.

[0019] The kinematic viscosity of the polyalphaolefin at a temperature of 100 °C can also be between 2 cSt and 10 cSt, between 55 cSt and 75 cSt, between 140 cSt and 160 cSt, between 280 cSt and 320 cSt, or between 900 cSt and 1100 cSt.

[0020] The dropping point (determined according to ASTM 5950) can be as low as -20 °C. Specifically, the dropping point of polyalphaolefin is as low as -30 °C.

[0021] The density of the polyalphaolefin polymer composition can be up to 0.860 g cm⁻³. Specifically, the density of the polyalphaolefin ranges between 0.825 g cm⁻³ and 0.855 g cm⁻³. It can also range between 0.840 g cm⁻³ and 0.855 g cm⁻³.

[0022] The mean molecular weight Mw of the polyalphaolefin can be at least 440 Da. Specifically, the mean molecular weight Mw of the polyalphaolefin is between 440 Da and 12,000 Da or between 1,000 Da and 10,000 Da. Most preferably, the mean molecular weight Mw of the polyalphaolefin is between 3,000 Da and 10,000 Da.

[0023] The polyalphaolefin may be a metallocene polyalphaolefin. The polyalphaolefin may have been produced by the use of a metallocene catalyst.

[0024] The polyalphaolefin may be a Ziegler-Natta polyalphaolefin. The polyalphaolefin may have been produced by using a Ziegler-Natta catalyst.

[0025] The polyalphaolefin can be a homopolymer or a copolymer.

[0026] Specifically, polyalphaolefin is a homopolymer of a C3 to C22 alpha-olefin. Therefore, alpha-olefins of length C3 to C22 are used as monomers to produce polyalphaolefin as a homopolymer. Preferably, C6 to C14 or C8 to C10 alpha-olefins are used as monomers for polyalphaolefin as a homopolymer.

[0027] The polyalphaolefin can be an alpha-octene homopolymer or an alpha-decene homopolymer, preferably an alpha-decene homopolymer.

[0028] As a copolymer, polyalphaolefin is composed of at least two different alpha-olefins of length C3 to C22 as comonomers. Specifically, two different alpha-olefins of length C6 to C14 or C8 to C10 are used as comonomers.

[0029] Polyalphaolefin can be a bipolymer.

[0030] The polyalphaolefin can be a synthetic fluid (at 23 °C and 1 bar), in particular, the polyalphaolefin is a completely synthetic fluid (at 23 °C and 1 bar).

[0031] The polyalphaolefin can be hydrogenated; in particular, the polyalphaolefin is fully hydrogenated.

[0032] The polyalphaolefin can be a mixture of different polyalphaolefins. For example, the polyalphaolefin can be a mixture of at least two polyalphaolefins that differ in their kinematic viscosity and / or in their (co-)monomers. At least two of the polyalphaolefins disclosed herein can be present as a mixture.

[0033] Polyalphaolefin can be present in the polymer composition at a proportion of up to 65 wt%. Generally, wt% values ​​refer to the total mass of the polymer composition. Specifically, the proportion of polyalphaolefin in the polymer composition ranges from 3 wt% to 65 wt% or from 3 wt% to 50 wt%. More specifically, the proportion of polyalphaolefin in the polymer composition can range from 3 wt% to 30 wt% or from 5 wt% to 30 wt%.

[0034] The proportion of polyalphaolefin in the polymer composition can be between 3 wt.% and 7 wt.%, between 7 wt.% and 12 wt.%, between 14 wt.% and 20 wt.%, between 17 wt.% and 23 wt.%, between 27 wt.% and 33 wt.% or between 35 wt.% and 45 wt.%.

[0035] The second polyolefin in the polymer composition is different from the polyalphaolefin. For example, different polymers can differ in their structure (e.g., the (co)monomers of the polymers) or in at least one property (e.g., hardness, density).

[0036] The second polyolefin can have a Shore A hardness of up to 90 at 23 °C (DIN ISO 7619-1; holding time 15 s). Specifically, the Shore A hardness at 23 °C is between 30 and 90.

[0037] The second polyolefin can be a plastomer or an elastomer.

[0038] Specifically, the second polyolefin is a polyolefin elastomer that has a density (DIN EN ISO 1183-1) between 0.860 g cm -3< and 0.889 g cm -3<.

[0039] The second polyolefin can also be a polyolefin plastomer, with a density between 0.890 g cm -3< and 0.910 g cm -3<.

[0040] The second polyolefin can be an elastomer with a density of less than 0.860 g cm⁻³. In particular, the elastomer has a density between 0.780 g cm⁻³ and 0.859 g cm⁻³ or between 0.800 g cm⁻³ and 0.859 g cm⁻³.

[0041] The second polyolefin can be a plastomer with a density of at most 0.910 g cm⁻³. In particular, the plastomer has a density between 0.860 g cm⁻³ and 0.910 g cm⁻³.

[0042] The second polyolefin can be a copolymer, in particular a random copolymer. Specifically, the second polyolefin is a copolymer comprising alpha-butene and a C2, C3, or C5 to C16 (alpha-)olefin as a comonomer.

[0043] The proportion of alpha-butene in the copolymer can be more than 50 mol%. Specifically, the proportion of alpha-butene in the copolymer is at least 60 mol% or at least 80 mol%.

[0044] The second polyolefin can be a copolymer, in particular a random copolymer, of propene and a C 2 , C 4 or C 5 to C 16 (alpha-)olefin.

[0045] The propene content in the copolymer can exceed 50 mol%. In particular, the propene content in the copolymer can exceed 60 mol% or 70 mol%.

[0046] The second polyolefin can be a copolymer, in particular a random or block copolymer, comprising ethene and a C5 to C16 (alpha) olefin as a comonomer. Specifically, one comonomer of the copolymer is ethene and another comonomer of the copolymer is a C5, C7, C9, or C10 to C16 alpha olefin.

[0047] The proportion of ethene in the copolymer can be greater than 50 mol%. Specifically, the proportion of ethene in the copolymer is at least 60 mol% or at least 70 mol%.

[0048] In general, the second polyolefin can be a bipolymer.

[0049] The second polyolefin is particularly preferred as an alpha-butene-ethene copolymer, wherein alpha-butene is present in the copolymer as a bipolymer in a concentration of more than 50 mol%.

[0050] Equally preferred is the second polyolefin an alpha-butene-propene copolymer (bipolymer) with a molar content of alpha-butene in the copolymer of more than 50 mol-%.

[0051] The second polyolefin may constitute a maximum weight fraction of 80% in the polymer composition. Specifically, the maximum weight fraction of the second polyolefin in the polymer composition is 70%.

[0052] The second polyolefin can also be present in the polymer composition at a proportion between 5 wt.% and 95 wt.%. More specifically, the proportion of the second polyolefin in the polymer composition is between 20 wt.% and 95 wt.% or between 50 wt.% and 95 wt.%.

[0053] The second polyolefin can be present in the polymer composition at a proportion between 55% and 70% by weight. Alternatively, the second polyolefin can be present in the polymer composition at a proportion between 83% and 93% by weight.

[0054] The polymer composition can include a third and / or fourth polymer (two polymers), wherein the third and fourth polymers are different from the polyalphaolefin and the second polyolefin, and the third polymer is different from the fourth polymer. Thus, the polyalphaolefin, the second polyolefin, the third polymer, and the fourth polymer are each different polymers.

[0055] The third and / or fourth polymer can be a polyolefin. The third and / or fourth polymer can have a Shore D hardness (DIN ISO 7619-1; holding time 15 s) at 23 °C of no more than 60. Specifically, the Shore D hardness of the third and / or fourth polymer is between 20 and 60.

[0056] The third and / or fourth polymer can be a homopolymer. Specifically, the third and / or fourth polymer is a homopolymer composed of a C2 to C12 alpha-olefin. The third and / or fourth polymer, as a homopolymer, can comprise a C2 to C8 alpha-olefin or a C2 to C6 alpha-olefin as its monomer.

[0057] It is particularly preferred that the third and / or fourth polymer is a polyethylene homopolymer (for example LDPE), a polypropylene homopolymer or an alpha-butene homopolymer.

[0058] The polypropylene homopolymer can be a syndiotactic polypropylene homopolymer. In particular, the degree of syndiotacticity (syndiotactic index) of the polypropylene homopolymer can be at least 75%. The degree of syndiotacticity (syndiotactic index) can be determined by NMR, IR, or GPC according to the methods described in US 5,476,914 B, preferably by NMR.

[0059] The third and / or fourth polymer can be a copolymer.

[0060] Preferably, the third and / or fourth polymer is a polypropylene copolymer. The polypropylene copolymer can be a syndiotactic polypropylene copolymer. The polypropylene copolymer can have a propylene content of at least 60 mol%, in particular at least 75 mol%, more preferably at least 90 mol%, even more preferably at least 95 mol%, and most preferably at least 98 mol%.

[0061] The polypropylene copolymer preferably comprises the monomers ethylene and propylene. Ethylene may be present in the propylene copolymer at a maximum concentration of 2 mol%.

[0062] The degree of syndiotacticity of the polypropylene copolymer can be at least 75%.

[0063] The third and / or fourth polymer, as a copolymer, can contain at least one or at least two (different) C2 to C12 alpha-olefins as comonomers. Specifically, the third and / or fourth polymer, as a copolymer, is composed of at least one or at least two (different) C2 to C8 alpha-olefins or C2 to C6 alpha-olefins.

[0064] The third and / or fourth polymer can be a bipolymer.

[0065] The third and / or fourth polymer is most preferred as a propene-ethene copolymer (bipolymer), in particular having a propene content higher than 50 mol%.

[0066] The third and / or fourth polymer can also be a propene-alpha-hexene copolymer (bipolymer) where the proportion of propene in the copolymer is more than 50 mol%.

[0067] The third and / or fourth polymer may each be present in the polymer composition at a maximum of 35 wt%. The third and / or fourth polymer may each be present in the polymer composition at a proportion between 5 wt% and 35 wt% or between 5 wt% and 27 wt%. Specifically, the proportion of the third and / or fourth polymer is between 5 wt% and 18 wt% or between 11 wt% and 18 wt%.

[0068] The MFI (mass flow index) of the polymer composition can be less than 30 g / 10 min, specifically less than 10 g / 10 min, and particularly preferably less than 5 g / 10 min, wherein the MFI is determined according to DIN EN ISO 1133 at 190 °C and 2.16 kg.

[0069] 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.

[0070] The polymer composition can be free of PVC (polyvinyl chloride).

[0071] In one embodiment, the polymer composition can be free of a copolymer that includes styrene as a comonomer.

[0072] The polymer composition can contain a maximum of 10 wt.% of a mineral oil, e.g. white oil; preferably the polymer composition contains a maximum of 5 wt.% of a mineral oil; particularly preferably the polymer composition is free of a mineral oil.

[0073] The polymer composition may contain up to 15 wt% additives. In particular, the polymer composition contains up to 8 wt% additives, most preferably a maximum of 6 wt% additives, and most preferably a maximum of 5 wt% additives.

[0074] Additives in the polymer composition may be selected from the group consisting of: pigments, nucleating agents, brighteners, stabilizers, surfactants, lubricants, antioxidants and combinations thereof.

[0075] It is preferred that the polymer composition does not contain an oxygen scavenger.

[0076] 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 0.10 and 0.40 or between 0.15 and 0.40.

[0077] The oxygen permeability rate of the polymer composition can be at most 1300 cm³ < m⁻² < d⁻¹ < bar⁻¹, preferably at most 900 cm³ < m⁻² < d⁻¹ < bar⁻¹, more preferably at most 750 cm³ < m⁻² < d⁻¹ < bar⁻¹. Particularly preferably, the oxygen permeability rate of the polymer composition lies between 300 cm³ < m⁻² < d⁻¹ < bar⁻¹ and 1300 cm³ < m⁻² < d⁻¹ < bar⁻¹ or between 300 cm³ < m⁻² < d⁻¹ < bar⁻¹ and 900 cm³ < m⁻² < d⁻¹ < bar⁻¹.

[0078] 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.

[0079] The total migration of the polymer composition can be a maximum of 5.50 mg cm⁻², preferably a maximum of 3.50 mg cm⁻², particularly preferably a maximum of 2.50 mg cm⁻², and even more preferably a maximum of 1.50 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 cm⁻² and 3.00 mg cm⁻² or between 0.80 mg cm⁻² and 2.50 mg cm⁻².

[0080] If a filled container is sealed by a container closure with a sealing element made of the polymer composition and with a surface / mass ratio of 1 cm -2< contact area of ​​the sealing element to 0.02 kg mass of the filling material in the container, a total migration limit of 60 mg kg -1< is met.

[0081] 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.

[0082] Different polymers, meaning those with varying polymer compositions, 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.).

[0083] 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.

[0084] 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.

[0085] 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.

[0086] The container can be a glass container, a plastic container, or a metal container. Specifically, the container is a glass container.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] Preferably, a vacuum is maintained in the closed vessel. The absolute pressure in the closed vessel can be a maximum of 200 hPa. Specifically, the absolute pressure in the sealed vessel is a maximum of 100 hPa.

[0092] The container sealed with the closure can have a maximum safety dimension of 10 mm, specifically a maximum safety dimension of 8 mm. Preferably, the maximum safety dimension is 6 mm. Most preferably, the maximum safety dimension is 4 mm.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] The container can be a glass container, a plastic container, or a metal container.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] The deformation of the sealing element is particularly preferred to be between 0.3 mm and 0.9 mm.

[0105] The food can be aseptically filled into the container.

[0106] The food can also be placed in the container at a temperature of no more than 10 °C.

[0107] The food can also be placed in the container at a temperature between 10 °C and 70 °C.

[0108] The food can also be placed in the container at a temperature between 70 °C and 98 °C.

[0109] 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.

[0110] The thermal treatment can be carried out at a temperature of at least 60°C.

[0111] 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.

[0112] Preferably, the pressure inside the sealed vessel during thermal treatment is lower than the pressure outside the sealed vessel.

[0113] 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. Figure 1 shows a side view of a cam-type rotary closure 1 with an annular sealing element 3, partially as a section; Figure 2 shows a side view of the cam-type rotary closure 1 with the sealing element 3 on a vessel 5, partially as a section; Figure 3 shows the cam-type rotary closure 1 with the sealing element 3 in a bottom view; Figure 4 shows an isometric view of a composite closure 61 (Combi-Twist); Figure 5 shows a partial axial section of the composite closure 61 (Combi-Twist) of Figure 4Figure 6 shows a side view of a press-on twist-off closure 21 (PT closure) with a sealing element 23, partially as a section; Figure 7 shows a side view of the PT closure 21 with the sealing element 23 on a vessel 25, partially as a section; Figure 8 shows a top view of the PT closure 21; Figure 9 shows a side view of a composite closure 41 (Band-Guard) with a sealing element 43, partially as a section; 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; Figure 11 shows a top view of the composite closure 41 (Band-Guard); Figure 12 shows an enlarged section of the cam-type twist-off closure of Figure 2 .

[0114] The Figures 1 and 3 Figure 1 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 Figure 2The 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 Figures 1 to 3 The illustrated cam-type rotary lock 1 comprises four cams 7, which are uniformly distributed around their circumference. The cuts that are in the Figures 1 and 2 Partially depicted, they correspond to section III-III in Figure 3 .

[0115] 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).

[0116] 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.

[0117] In Figure 2The 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).

[0118] 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.

[0119] The cam rotary lock 1, as in the Figures 1 to 3 The figure 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.

[0120] 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.

[0121] The Figures 4 and 5 show 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.

[0122] 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.

[0123] 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 Figures 9 to 11 is designed and with a view to the Figures 9 to 11 will be described in more detail.

[0124] 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.

[0125] In the Figures 6 to 8 A press-on twist-off closure 21 (PT closure) is shown. 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.

[0126] 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 threaded elements 26 of the vessel opening is formed in the sealing element 23.

[0127] An upper end 24 of the vessel opening 25a contacts the sealing element 23.

[0128] To open the vessel 25, the PT closure 21 is removed from the vessel 25 by a twisting motion.

[0129] Figures 9 to 11 show a composite shutter 41 (Band-Guard) which is functional analogous to the described PT shutter 21.

[0130] 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.

[0131] The plastic section of the composite closure 41 can include several axially extending indentations 56 to increase the stability of the closure.

[0132] 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.

[0133] 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.

[0134] The distance h 3 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 Figure 12 The following is shown and described with regard to a cam-type rotary closure 1. The distance (height) h 3 is to be determined analogously for other closure types.

[0135] The sealing element 3, clamped between the vessel opening 5 and the support 11 of the vessel closure 1, has a height h3, which 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 through, 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 impaired 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:

[0136] Examples of polymer compositions for sealing elements in a vessel closure are shown in Tables 1, 2, and 3. The examples are named with Ex. followed by a sequential number for the respective example.

[0137] The component names shown in the tables stand for ... PAO-5 Polyalphaolefin with a kinematic viscosity at 100 °C of approximately 5 cSt, PAO-65 Polyalphaolefin with a kinematic viscosity at 100 °C of approximately 65 cSt, PAO-150 Polyalphaolefin with a kinematic viscosity at 100 °C of approximately 150 cSt, PAO-300 Polyalphaolefin with a kinematic viscosity at 100 °C of approximately 300 cSt, C4C2 alpha-butene-ethene copolymer with an alpha-butene content of more than 50 mol-%, C4C3 alpha-butene-propene copolymer with an alpha-butene content of more than 50 mol-%, C2 Ethene homopolymer (LDPE), C3C2 Propene-ethene copolymer with a propene content of more than 50 mol%, C3C6 Propene-alpha-hexene copolymer with a propene content of more than 50 mol-%, C4 alpha-butene homopolymer.

[0138] The polyalphaolefins (PAO-5, PAO-65, PAO-150, PAO-300) are commercially available from Chevron Phillips or from ExxonMobil (e.g. SpectraSyn series).

[0139] The alpha-butene-ethene copolymer has a Shore A hardness of 60 and a density of 0.870 g cm -3<.

[0140] The alpha-butene-propene copolymer has a Shore A hardness of 87 and a density of 0.890 g cm -3< .

[0141] The ethene homopolymer exhibits a Shore D hardness of 48 and a density of 0.928 g cm -3< .

[0142] The density of the propene-ethene copolymer is 0.900 g cm -3< .

[0143] The propene-alpha-hexene copolymer exhibits a density of 0.900 g cm⁻³.

[0144] The alpha-butene homopolymer has a Shore D hardness of 54. Table 1 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Component, wt.% PAO-5 4,8 9,1 16,7 9,1 PAO-65 9,1 PAO-150 9,1 PAO-300 9,1 C4C2 68,5 65,4 59,9 65,4 65,4 65,4 C4C3 87,2 C2 15,2 14,5 13,3 14,5 14,5 14,5 C3C2 7,6 7,3 6,7 7,3 7,3 7,3 C3C6 C4 Additive 3,9 3,7 3,4 3,7 3,7 3,7 3,7 Characteristic Coefficient of friction, dimensionless 0,31 0,33 0,39 0,36 0,23 0,18 0,28 Total migration, mg cm⁻² 2,14 3,27 5,11 1,35 1,15 0,99 2,90 Oxygen permeability rate cm 3< m -2< d -1< bar -1< 662 809 1162 732 681 650 680 Table 2 Ex. 8 Ex. 9 Ex. 10 Ex. 11 Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 Component wt.% PAO-300 20,0 30,0 40,0 5,0 10,0 20,0 10,0 10,0 10,0 C4C2 90,9 85,9 75,9 61,9 61,9 61,9 C4C3 75,9 65,9 55,9 C2 24,0 C3C6 24,0 C4 24,0 Additive wt.% 4,1 4,1 4,1 4,1 4,1 4,1 4,1 4,1 4,1 Table 3 Ex. 17 Ex. 18 Ex. 19 Ex. 20 Ex. 21 Ex. 22 Ex. 23 Ex. 24 Component wt.% PAO-5 9,1 16,7 9,1 16,7 PAO-300 5,0 10,0 30,0 40,0 C4C2 65,4 59,9 65,4 59,9 65,9 55,9 C4C3 90,9 85,9 C2 14,5 13,3 14,5 13,3 C3C6 7,3 6,7 C4 7,3 6,7 Additive wt.% 3,7 3,4 3,7 3,4 4,1 4,1 4,1 4,1

[0145] In general, no specific component is necessarily present in any of the polymer compositions. Specifically, the increased occurrence of a component in the examples does not indicate that this component must necessarily be included in the polymer composition. Rather, components from the example compositions can be omitted or replaced by other components. Likewise, components can be added.

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 and the polymer composition comprises ... (a) a polyalphaolefin with a kinematic viscosity, determined according to ASTM D445 / ISO 3104, of at least 4 cSt, at a temperature of 100°C, and / or with a dropping point, determined according to ASTM 5950, of at most -10°C; and (b) up to 95% by weight of a second polyolefin.

2. Vessel closure according to claim 1, wherein the polyalphaolefin is present in the polymer composition at a level of up to 65% by weight, preferably between 3% and 65% by weight, more preferably between 3% and 50% by weight, even more preferably between 3% and 30% by weight, most preferably between 5% and 30% by weight.

3. Vessel closure according to one of the preceding claims, wherein the second polyolefin has a Shore A hardness, determined according to DIN ISO 7619-1 at 23°C, of at most 90, in particular between 30 and 90.

4. Vessel closure according to one of the preceding claims, wherein the polymer composition comprises a third polymer, wherein the third polymer has a Shore D hardness, determined according to DIN ISO 7619-1 at 23°C, of at most 60, in particular between 20 and 60.

5. Vessel closure according to claim 4, wherein the third polymer is a homopolymer composed of a C2 to C12 (alpha)olefin, preferably of a C2 to C8 (alpha-)olefin, particularly preferably of a C2 to C6 (alpha-)olefin.

6. Vessel closure according to claim 4, wherein the third polymer is a copolymer and the copolymer comprises at least one or at least two C2 to C12 (alpha-)olefins as comonomers, preferably at least one or at least two C2 to C8 (alpha-)olefins as comonomers, particularly preferably at least one or at least two C2 to C6 (alpha-)olefins as comonomers.

7. Vessel closure according to one of the preceding claims, wherein the polymer composition comprises a fourth polymer, wherein the fourth polymer is present in the polymer composition at a level of at most 35% by weight, preferably between 5% and 35% by weight, more preferably between 5% and 27% by weight, even more preferably between 5% and 18% by weight, most preferably between 11% and 18% by weight.

8. Vessel closure according to claim 7, wherein the fourth polymer is a homopolymer and the homopolymer is composed of a C2 to C12 (alpha)olefin, preferably of a C2 to C8 (alpha-)olefin, particularly preferably of a C2 to C6 (alpha-)olefin.

9. Vessel closure according to claim 7, wherein the fourth polymer is a copolymer and the copolymer includes at least one or at least two C2 to C12 (alpha-)olefins as comonomers, preferably at least one or at least two C2 to C8 (alpha-)olefins as comonomers, particularly preferably at least one or at least two C2 to C6 (alpha-)olefins as comonomers.

10. Vessel closure according to any one of the preceding claims, wherein the polymer composition has an oxygen transmission rate, determined according to DIN 53380, of less than 1300 cm3 m-2 d-1 bar-1, preferably of less than 900 cm3 m-2 d-1 bar-1, more preferably of less than 750 cm3 m-2 d-1 bar-1.

11. Vessel (5, 25, 45) with a vessel mouth (5a, 25a, 45a) and a closable opening at the end of the vessel mouth, wherein the opening is closed with a vessel closure (1, 21, 41, 61) according to any one of the preceding claims.

12. Vessel according to claim 11, wherein the vessel closure comprises a carrier (11, 31, 51, 71) and the sealing element (3, 23, 43, 63) and wherein the sealing element between an upper end (4, 24, 44) of the vessel mouth and a lower side of the carrier (11, 31, 51, 71) has a height (h3) of at most 1.0 mm, preferably at most 0.8 mm, particularly preferably at most 0.7 mm, in the axial direction of the vessel; and / or wherein the vessel closure comprises a carrier (11, 31, 51, 71) and the sealing element (3, 23, 43, 63), and wherein the sealing element has a height (h3) between an upper end (4, 24, 44) of the vessel mouth and a lower side of the carrier (11, 31, 51, 71) of at least 0.2 mm, preferably at least 0.4 mm, particularly preferably at least 0.5 mm, in the axial direction of the vessel.

13. A method for producing a sealed and filled vessel with the following steps: (a) Provision of a vessel (1, 21, 41, 61) with a vessel mouth (5a, 25a, 45a) and a closable opening at the end of the vessel mouth; (b) Filling of the vessel with a foodstuff through the opening of the vessel; (c) Closing of the opening of the vessel with a vessel closure according to any one of claims 1 to 10.

14. The method of claim 13, wherein the vessel closure is treated at a temperature of at least 90°C before the opening of the vessel is closed with the vessel closure.

15. A method according to any one of claims 13 or 14, wherein the absolute pressure in the sealed and filled vessel is at most 200 hPa, preferably at most 100 hPa.