Sealing disc for a closure cap for containers, especially bottles

Abstract

Sealing disc for a closure cap for containers, in particular for bottle closures for liquids fermented with yeast, wherein the sealing disc has a layer of polymer foam as a cover layer (1), characterized in that the sealing disc has an active layer with an active substance (3) that binds sulfur compounds, wherein i) the active layer is formed from the active substance and is applied to a plastic film (4), or ii) the active substance is incorporated into the plastic film (4), wherein the plastic film is made from at least one polymer selected from ethylene homopolymers, linear copolymers of ethylene with one or more α-olefins having 3 to 14 carbon atoms, polypropylene, unstretched polypropylene, oriented polypropylene, polyamide, and oriented polyamide.

Description

[0001] The present invention relates to a sealing disc for a closure cap for containers, such as bottle closures, which is particularly suitable for bottles filled with fermented juices from fruit or grapes, such as fruit wines or wines.

[0002] In particular, the present invention relates to a sealing disc with which so-called blockages can be intercepted.

[0003] Böckser are odor defects in beverages fermented with yeast, especially in wines, which, depending on the stage of development, are reminiscent of rotten eggs, burnt rubber, burnt onions, sweat or similar.

[0004] The cause of the formation of sulfur odors is the formation of thiols by yeast during the fermentation process. These initially formed thiols react with other ingredients in the beverage to form increasingly complex sulfur compounds, all of which are odorously active.

[0005] It goes without saying that such unpleasant odors are particularly disturbing in wines.

[0006] The use of multilayer polymer-containing seals for bottle or container closures is well known: US Patent 3,928,109 by Pollock et al. relates to a multilayer sealing disc that can be firmly bonded to a surface, such as a container rim, by induction heating, thus tightly sealing the container. The sealing disc has a polymer layer as the bottom layer to be bonded to the surface. Since a polymer layer as such cannot be heated by induction, a metal layer is provided adjacent to the polymer layer.

[0007] US Patent 6,183,827 B1 to Folchini et al relates to a closure for food containers, the closure comprising a metal capsule into which a PVC-free seal is inserted and which is attached to the underside of the capsule by means of an adhesive.

[0008] Furthermore, US Pat. No. 5,839,592 to Hayes describes a multilayer seal for a bottle closure, wherein the seal is formed from a first upper and a second lower polymer layer facing the bottle opening, the lower layer being softer than the upper layer. An oxygen-impermeable layer can be provided between the first and second layers.

[0009] US 2013 / 0161282 A1 by Peck describes a sealing disc with a multi-layer structure that can prevent or at least reduce oxygen ingress into wine bottles. In addition to additional layers, a foam layer is also provided. Furthermore, a method for controlling the oxygen permeability of bottle closures, such as wine bottles, is described.

[0010] US Patent 4,269,321 to Ichinose et al relates to a crown closure made using a modified polyolefin-containing primer layer composition which may be applied to a metallic substrate.

[0011] US 2008 / 0073308 A1 by Yousif also describes a multi-layer sealing disc for containers featuring metal-free grip tabs that extend beyond the edge of the sealing disc. The sealing disc serves to seal the container opening and remains on the container rim even after the cap is removed.

[0012] US Patent 2,020,776 to Goebel describes a crown-shaped bottle closure having a cushioning insert and a facing material comprising a carrier layer bonded to the cushioning insert and a substantially continuous, durable film bonded to the carrier layer and made of sprayed metal.

[0013] GB 451 162 A describes an insert in a metal bottle stopper, the insert being formed at least partly from a finely divided animal tissue.

[0014] US Patent 4,935,273 to Ou-Yang relates to an inner seal for a container closure, for example a bottle closure, formed from a pressure-activated adhesive that is a copolymer of butadiene and acrylonitrile or with methacrylonitrile.

[0015] EP 0 803 445 A1 by Trombach relates to a sealing disc for a closure cap for containers, in particular for alcoholic beverages or wines, wherein the sealing disc comprises a layer of an oxygen-impermeable substance and a layer of an oxygen-depleting substance.

[0016] However, none of the cited publications contains any reference to the problem of the formation of scum, particularly in already filled bottles, or how to avoid it.

[0017] A number of measures have been developed to eliminate sulfur from wines. The addition of food-grade copper salts, such as copper sulfate, is widely used, as the copper ions can bind the sulfur compounds. However, these measures can only be carried out before bottling.

[0018] However, it is not uncommon for the odor to reappear after successful treatment or to appear for the first time after bottling. Thioacetic acid esters, which themselves are odor-inactive, are responsible for the occurrence in these late stages. During storage, the thioacetic acid esters form other substances in a chain reaction, exhibiting increasingly higher odor intensities.

[0019] The thioacetic acid esters that cause late-stage bockstaining do not react with copper ions. They represent an initially hidden precursor that cannot be preventively removed by treatment with copper salts. Therefore, even wines that have already been treated with copper salts are not protected against the recurrence of such bockstaining. The economic damage caused by bockstaining on the bottle, even in award-winning wines, is considerable.

[0020] There was therefore a need for a measure that could eliminate scum even in bottled wines. It goes without saying that such a measure is not limited to wines, but is equally suitable for other beverages prone to scum, such as fruit wines, distillates, etc.

[0021] According to the invention, this object is achieved by a sealing disc for closure caps of containers, in particular bottles, into which beverages endangered by taint are filled, according to claim 1, wherein an active substance is incorporated into the sealing disc which can bind the sulphur compounds which cause taint.

[0022] The sulfur compounds that cause scum are volatile substances. They rise to the top of the bottle and accumulate in the space between the liquid level and the closure. From there, they come into contact with the sealing disc in the closure cap and diffuse into it. In doing so, they come into contact with the active substance contained in the sealing disc and are neutralized by the active substance.

[0023] Sealing discs for closure caps for containers such as bottles typically have a laminate structure with layers of different materials that fulfill different functions within the sealing disc. The sealing discs are inserted into the closure caps, such as screw caps, for the bottles and have a suitable diameter. The closure caps can be made of metal, often aluminum, or plastic.

[0024] The sealing discs serve to prevent liquid from seeping through. Sealing discs are also known to prevent gas, especially atmospheric oxygen, from penetrating the interior of the bottle from the outside and impairing the quality of the beverage.

[0025] The sealing disc according to the invention can be a composite film comprising two or more layers. Depending on requirements, the layers can be formed from various materials. They can be made of plastic, metal, foam, paper, and optionally other materials. The sealing disc contains at least one active layer with an active substance for binding or neutralizing the sulfur compounds that cause sulfur buildup.

[0026] The production of sealing discs made from a composite film is well known. The individual layers can be joined together to form a composite film by lamination, depending on the requirements using solvent-based, solvent-free, or water-based adhesives, or by extrusion lamination, for example, with adhesion promoters.

[0027] The active substance can be a metal or metal alloy that reacts with the sulfur compound(s). Examples include copper, tin, silver, gold, antimony, or alloys thereof. The type of reaction is irrelevant as long as the sulfur compound(s) are converted into a form that eliminates or prevents the unpleasant odor that characterizes the sulfur odor.

[0028] The active substance can be incorporated into one or more of the layers that make up the composite film. The active substance itself can be present in the form of one or more layers. For example, the active substance can be applied or incorporated as a layer onto a plastic film. The plastic film with the active substance or active layer can be a composite film consisting of two or more layers, which can also consist of different polymers.

[0029] Examples of suitable polymers for the plastic film with active substance are ethylene homopolymers such as LDPE (low-density polyethylene) and HDPE (high-density polyethylene), or linear copolymers of ethylene with one or more α-olefins having, for example, 3 to 14 carbon atoms, such as 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene. Examples of suitable copolymers are LLDPE (linear low-density polyethylene), MDPE (medium-density polyethylene), and VLDPE (very low-density polyethylene). Other suitable polymers are polypropylene, unstretched polypropylene (CPP, cast polypropylene), oriented polypropylene (OPP, oriented polypropylene), polyamide, or oriented polyamide (OPA, oriented polyamide).

[0030] The individual layers of the plastic film containing the active substance usually have thicknesses between 8 and 200 µm.

[0031] If a metal layer is used as the active substance, it can be applied to the plastic film using conventional sputtering or metallization processes, for example. It can also be applied to the plastic film in the form of a metal-containing printing ink. This layer of active substance is typically 0.5 to 30 µm thick.

[0032] The active substance can also be incorporated into the plastic film in the form of metal particles.

[0033] As a further layer, the sealing disc according to the invention preferably contains an oxygen-impermeable layer or gas barrier layer.

[0034] The oxygen-impermeable layer serves a dual function. Firstly, it prevents oxygen or other gases from entering the bottle. Secondly, it prevents gaseous components, such as alcohol, from passing through the sealing disc from the inside of the bottle to the outside. This is a disadvantage, as it also retains the volatile sulfur compounds that cause stale odors. However, the ingress of oxygen should be prevented, as this can lead to a significant reduction in the quality of the wine.

[0035] The oxygen-impermeable layer can be a metal foil, such as tin, copper, or aluminum. It can be made of a plastic material with gas barrier properties. Examples include plastic films based on polyvinylidene chloride or ethylene-vinyl alcohol copolymer (EVOH).

[0036] In order to avoid hindering the contact of the sulfur compounds with the active substance, the gas barrier layer in the sealing disc should be provided on the side of the layer with the active substance that is facing away from the inside of the bottle.

[0037] According to one embodiment, the layer containing the active substance can simultaneously act as an oxygen-impermeable layer. For example, if it is a layer made of a material that, according to the invention, acts as an active substance that binds sulfur compounds and is also oxygen-impermeable. One example is copper.

[0038] The sealing disc also has an additional layer of polymer foam. The polymer foam can be polyethylene foam or polypropylene foam. The foam layer typically forms the topmost layer, i.e., the cover layer, of the sealing disc's layered structure and is generally thicker than any of the other layers. The sealing disc is preferably covered by a cap or screw cap on the side of its topmost foam layer.

[0039] The sealing disc can either be inserted into the cap before closing the closure, for example, before tightening a screw cap, or be secured to the container rim in some other way. For example, it can also be placed first on the bottle neck opening and then the closure slipped over it. Closing the closure, such as twisting, rolling, or otherwise securing it to the bottle neck, simultaneously applies a compressive load. This compresses the sealing disc to a smaller thickness.

[0040] The foam layer provides the appropriate clamping pressure through compression force and thus creates a seal.

[0041] The thickness of the foam layer and its elastic design allow for tolerances in the closures and bottle necks to be compensated. This prevents, for example, any liquid (including vapor) that might penetrate the bottle from the outside from entering. Furthermore, the foam layer of the sealing disc, due to its greater thickness compared to the other layers, provides stability and particularly good handling.

[0042] In addition to the layers already listed, additional layers may be provided. These may be active layers that extend the shelf life of the beverage or maintain or even improve its condition.

[0043] For beverages that react with oxygen, such as wine, sealing discs are advantageous, as they can protect the beverage from the oxygen trapped in the container. An oxygen-absorbing layer can be provided as an additional active layer.

[0044] If necessary, a paper layer can also be included. A paper layer between the foam layer and the underlying layer improves the adhesion between these layers and increases the seal.

[0045] The invention will be explained in more detail below using examples of sealing discs according to the invention, some with reference to the attached figures. In the examples, the layer structure is described from top to bottom (towards the inside of the bottle). 1. Example:

[0046] The sealing disc is constructed, from top to bottom, from a first layer of foam, a second layer of paper, a third layer of a gas barrier layer, and a polymer film with an active layer. The individual layers can be bonded together by adhesive layers, as is common in the production of such layered laminates.

[0047] The first layer of foam can be made of polyethylene or polypropylene foam with a density of 80 to 500 g / m 3 and a thickness of 0.2 to 4 mm.

[0048] Below the first layer, a second layer of paper, for example 60 g paper, is provided.

[0049] A gas barrier layer is arranged beneath the paper layer. The gas barrier layer can be a metal foil, e.g., made of tin, aluminum, or copper, or a gas-impermeable plastic, such as polyvinylidene chloride. The thickness of the gas barrier layer is, for example, 10 to 30 µm. This comparatively thin thickness of the gas barrier layer is sufficient to exert a barrier effect, particularly against the ingress of gaseous oxygen and gaseous alcohol.

[0050] Beneath this, a polymer film with an active layer is provided. The active layer is made of an active substance that reacts with the sulfur compounds that cause odor, thus removing them from the interior of the bottle, thereby eliminating the typical unpleasant odor. In this example, the active layer is made of copper. The copper is applied to a polyethylene film. The polyethylene film forms the bottom layer of this embodiment of a sealing disc according to the invention. 2. Example:

[0051] Fig. 1 shows the layer structure of an embodiment of a sealing disc according to the invention with a top layer 1 made of polyethylene foam with a thickness of 1.9 mm and a density of 250 kg / m 3 , a layer 2 of paper with 60 g / m 2, an active layer 3, which is arranged below the paper layer 2 and consists of tin or copper and has a thickness of 20 µm, and a layer 4 of polyethylene film with a thickness of 50 µm, which forms the lowest layer of the layer structure, i.e. the layer which points directly towards the interior of the bottle.

[0052] In particular, if the active layer 3 is made of copper, it can also fulfil the function of an oxygen barrier layer. 3. Example:

[0053] Fig. Figure 2 shows another embodiment of a layered structure of a sealing disc according to the invention. Here, too, the top layer 1 is made of polyethylene foam with a density of 250 kg / m 3 and has a thickness of 1.9 mm. Underneath is a paper layer 2 made of 60 g / m 2The underlying layer 3 is an oxygen barrier layer made of aluminum with a thickness of 15 µm. The active layer here is a composite of copper lacquer 3, which is applied to a polyethylene film 4, wherein the polyethylene film has a thickness of 50 µm and the copper lacquer is applied in an amount of 3 g / m 2 is applied.

[0054] It should be noted that in the Fig. 1 and Fig. 2 the layer thicknesses are not shown to scale.

[0055] All layers completely cover the underside of the layer above.

[0056] The sealing disc is either pre-inserted into a prefabricated cap, then secured and clamped into place. The layers of the sealing disc are already bonded together. When the cap is rolled on or otherwise secured to the bottle neck, additional stress is applied. The sealing disc located in the closure is compressed. The bottle interior is thus sealed hermetically by the sealing disc and the cap.

[0057] The sealing discs are not only suitable for closures for wine bottles or other alcoholic beverages, but are also advantageous wherever sulfur compounds are formed inside a container, which correspond to a sulfur sulfur.

Claims

[1] Sealing disc for a closure cap for containers, in particular for bottle closures for liquids fermented with yeast, wherein the sealing disc has a layer of polymer foam as a cover layer (1), characterized by that the sealing disc has an active layer with an active substance (3) which binds sulfur compounds, wherein i) the active layer is formed from the active substance and is applied to a plastic film (4), or ii) the active substance is incorporated into the plastic film (4), wherein the plastic film is made of at least one polymer selected from ethylene homopolymers, linear copolymers of ethylene with one or more α-olefins having 3 to 14 carbon atoms, polypropylene, unstretched polypropylene, oriented polypropylene, polyamide, and oriented polyamide. [2] Sealing disc according to claim 1, characterized bythat the active substance is a metal selected from copper, tin, silver, gold, antimony, alloys thereof. [3] Sealing disc according to one of claims 1 or 2, characterized by that the plastic film (4) is a composite film made of two or more polymer layers. [4] Sealing disc according to claim 3, characterized by that the composite film contains at least one active layer (3) formed from the active substance. [5] Sealing disc according to one of the preceding claims, characterized by that an oxygen-impermeable layer (5) is additionally provided, which is arranged in the sealing disc on the side of the active layer with the active substance, which faces the cover layer (1). [6] Sealing disc according to one of the preceding claims, characterized by that the active layer with active substance (3) is applied as a metal-containing covering paint to the plastic film (4). [7] Use of a sealing disc according to one of the preceding claims for a bottle closure. [8] Use according to claim 7, wherein the bottle is a wine bottle.

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