DE102012006760A1 - Blister packaging useful as a packing e.g. for pharmaceuticals or cosmetics, comprises blister foil with deep drawn portion, cover foil connected to blister foil, and biopolymer, where blister foil has support with polymeric barrier layer - Google Patents

Abstract

Blister packaging comprises: a blister foil with a deep drawn portion; a cover foil, which is connected to the blister foil; and at least 50 wt.% at least one biopolymer, based on the dry weight of the blister packaging. The blister foil has a support with less than 10 wt.% polymeric barrier layer, based on the dry weight of the blister packaging. Independent claims are also included for: (1) blister foil for the blister packaging, comprising the support applied with at least one polymeric barrier layer, where the support is a foil, whose dry mass comprises at least 95 wt.% biopolymer, and the polymeric barrier layer is present in an amount of less than 5 wt.%, based on the weight of the support and the polymer barrier layer comprises polyethylene; and (2) producing the blister foil, comprising applying the polymeric barrier layer on the support by extruding.

Description

The invention relates to a biopolymer-based, in particular biodegradable blister packaging, their preparation and use, as well as the blister and cover sheets suitable for their production and their production and processing.

Blister packs are used on a large scale, they usually consist of a so-called blister film, which provides the main stability of the packaging and has deformed, usually deep-drawn areas in which the product to be packaged fits, and a cover sheet as a conclusion. The cover sheet may be peelable and / or resealable connected to the blister sheet, however, often the cover sheet is destroyed, usually locally torn when the product is removed.

The known blister packs offer good protection of the products contained therein against moisture loss or become moist and against oxygen, provide good visibility and easy removal, but disadvantageous is that they consist of materials such as polyvinyl chloride (PVC) for the blister film and aluminum for the cover sheet that are very energy intensive to manufacture. In addition, z. B. in the case of PVC in the production of highly environmentally hazardous substances used. Such blister packs according to the prior art are also virtually rotting and are often burned, again toxic substances. In addition, the organic materials used are based on petroleum instead of renewable raw materials.

Also in other areas of the packaging industry, eg. As in protective films for food, films are often used, in particular multilayer laminated films to the required functionalities such. B. tear resistance, moisture resistance, gas barrier effect and light protection.

Increasingly, in response to growing environmental awareness and the foreseeable shortage of fossil resources, there is a demand for films of polymeric materials that are at least partially of biological origin and / or biodegradable. Such materials are also referred to below as biopolymers.

For packaging materials with relatively low functional requirements, such. As for shopping bags, this is already successful, and it may even cause problems with too low Kompostiergeschwindigkeit.

The use of biopolymers for blister packs, however, is much more challenging, since their above-mentioned functionalities initially seem to contradict the possible use of a large number of biopolymers. Thus, a very good water resistance and a pronounced water vapor barrier effect considerably hinder the rapid biodegradability. In addition, films that consist exclusively of biopolymers, such as. B. from starch, often brittle, less tear-resistant, inelastic and cloudy. Many such materials, such as. As starch, are also not resistant to water and persistently high humidity.

Out WO2008 / 094451 Compositions are known which contain at least 85% by weight of a biopolymer which may be hydroxyalkyl-modified starch, the compositions additionally containing an olefin copolymer and optionally another polymer. These compositions are preferably melted in an extruder with the addition of water and can be extruded as a film or integrated into a multilayer extrudate or laminate. Only a few special possible layer sequences are mentioned without going into details. The compositions may be biodegradable without being able to discern from the description which embodiments are suitable for biodegradability and to what extent or under what conditions the biodegradability can be achieved. The materials have disadvantages regarding rapid biodegradability and are only compostable to an inadequate proportion. They are therefore disadvantageous for packaging that should be compostable in large-scale industrial plants. This applies all the more for less controlled conditions or even in the open field.

WO2006 / 042364 describes a composition having barrier properties against e.g. As carbon dioxide or oxygen, which has up to 90 wt .-% of an optionally modified starch. Laminated on a support, the resulting film is suitable as a packaging material, in particular for foodstuffs. The barrier layer makes up only a small part of the total multilayer material. Also, this material is only partially biodegradable and insufficiently compostable.

Out WO01 / 54828 are multi-layered arrangements are known, which are applied to a support, as z. In WO99 / 46121 is described. Compostable plastic films as supports are not described therein and the disclosed methods are not easily transferred to compostable materials.

From the prior art, therefore, no high-quality blister packs with effective moisture barrier are known, which consist to a large extent of biopolymers and especially none that are suitable for composting and there are no prior art materials and methods of manufacture could be used for this.

The invention is thus based on the object to provide a blister pack, which has the advantages of known blister packs, but which consists predominantly of biopolymers and which is preferably compostable. In particular, the packaging should be suitable for products from the areas of nutritional supplements, cosmetics and pharmaceuticals and meet the requirements DIN EN 13432 for compostable packaging. At the same time the blister pack should have a water vapor and / or oxygen barrier effect, which meets the requirements of the products packed therewith and their storage conditions.

It has now surprisingly been found that it is possible to apply very thin layers of a material with good moisture barrier in very high quality and with very good adhesion to a film of biopolymer and that on the one hand a good protective effect is achieved, the thus obtained If necessary, however, it can still be thermoformed and can meet the requirements for a compostable material.

The invention therefore relates to a blister pack consisting of a blister foil and a cover foil, wherein the blister foil has at least one deep-drawn region which can be filled with a product, also referred to below as filling material and wherein the cover foil is connected to the blister foil characterized in that the blister pack (without the contents) based on their dry weight to at least about 50 wt .-%, preferably at least about 75 wt .-% and in particular at least 95 wt .-%, preferably 98 wt .-%, from at least one biopolymer, which is preferably biodegradable and wherein at least the blister film on a support at least one polymer layer, hereinafter also referred to as polymer barrier layer, the mass based on the dry weight less than about 10 wt .-%, preferably less than about 5 Wt .-% and in particular less than about 3 wt .-% of the total blister pack (without the F waste).

That the packaging consists to a certain extent of at least one biopolymer means that in one or more layers or films of which the packaging is constructed, in each case the same or different biopolymers may be contained alone or in admixture, alone or together account for the said share.

The biopolymer-based blister package of the invention already provides environmental benefits when it is collected along with conventional packaging and then burned. However, the packaging is preferably fed to composting after use, for which purpose the variants described below are particularly suitable.

The empty or emptied blister pack according to the invention - and thus also the biopolymers - should preferably completely after DIN EN 13432 be compostable. However, if parts of the package, for. As the cover sheet, are easily removable mechanically, this requirement does not apply to the easily removable parts, which can then be disposed of conventionally.

In addition, it is possible that the blister pack is provided for composting, in which prior to the usual process steps, the material is shredded or shredded or in another way the surface thereof is increased, such. B. by rolling over with at least one needle roller. In this case, the blister pack according to the invention meets the requirements DIN EN 13432 preferably after such previously performed process steps.

In an advantageous embodiment of the invention, the blister pack meets the requirements DIN EN 13432 only after removal of at least a portion of the contents, so after piercing the cover sheet at least one point. This has the advantage that the packaging is particularly well protected until the removal of the filling material against biodegradation and thus a particularly long storage time, even under unfavorable conditions, such. B. allows a high humidity.

For this embodiment, it is preferred if the cover film and / or the blister film, in particular both, have a highly effective moisture barrier towards the outside, but the moisture barrier is less effective in the interior, ie in the direction of the filling material. The WVTR (water vapor transmission rate) of the outer barrier layer (s) is preferably in the range of about 10 to about 1 g / (m ² · d), in particular from about 5 to about 0.5 g / (m ² · d) and the WVTR of the inner barrier layer (s) is higher than the value of the respective outer barrier layer, preferably at least about 25% higher, and more preferably at least about 75% higher.

It is a significant advantage of the blister package of the present invention that by appropriate design of the blister and cover sheet or the layers applied thereto, depending on the nature of the filling, an optimal ratio of (i) durability of the package, (ii) their protective effect against moisture, oxygen and other gases and odors, and (iii) their composting speed can be adjusted.

In a preferred embodiment of the invention, the permeability of the blister pack and cover sheets for water vapor and / or oxygen used for the blister pack is in each case at most about 50 g / (m ² · d) at 38 ° C. and 90% relative humidity (r. ), in particular at most about 30 g / (m ² · d) at 38 ° C and 90% r. F., more preferably at most about 15 g / (m ² · d) at 38 ° C and 90% r. F .; and for particularly moisture-sensitive products a maximum of about 5 g / (m ² · d) at 38 ° C and 90% r. F., in particular at most about 2 g / (m ² · d) at 38 ° C and 90% r. F., and more preferably at most about 1 g / (m ² · d) at 38 ° C and 90% r. F ..

In a preferred embodiment of the invention, the cover foil and / or the blister foil consist of a carrier foil which ensures the mechanical stability and on which one or more layers are applied. These layers can be applied independently of one another or on both sides of the respective carrier film. In the context of the invention, polymer barrier layers and other functional layers are distinguished, which are described below by way of example. Each of these layers can also be arranged several times in any order on each side of the respective carrier film. Preferred constructions (arrangements of layers) are described below for the blister sheets and coversheets of the invention.

In a preferred embodiment of the invention, at least one of the carrier films, in particular the carrier of the blister film, is a film whose dry mass is at least 50% by weight, preferably at least 75% by weight and in particular at least 95% by weight. -% consists of a biopolymer. Such a preferred carrier film of the invention is also referred to below as a biocarrier.

The durability of the blister packaging from the time of production to the complete removal of the contents should be at least as long as perishable contents, such as the durability of each therein contents or any products as long as the time required for the respective product as usual residence time is considered in the packaging. An unnecessarily long shelf life of the packaging is preferably to be avoided, since this usually impairs compostability unnecessarily. The durability of the contents can be very different. As an example, it can be in the food industry sometimes only a few days, in other cases, for. In biscuits, but also about 2 years or up to about 5 years. Preferably, the shelf life of the blister package of the invention is at least about 10%, but at most about 100% longer than the time considered to be the typical residence time in the package for the particular product.

The durability of the blister packaging is particularly due to moisture and temperature, but also by other environmental factors such. B. sun rays or artificial light. It can be adjusted as described below by the design of the blister and cover sheets, so that it is adapted to the requirements of the contents and the storage or storage conditions.

The preparation of the blister package of the invention includes the steps known for conventional blister packaging, and the like. a. their packaging, thermoforming, cleaning, filling and welding of blister and cover sheet and can be carried out by the known methods. Also with regard to storage conditions and transport of the finished packaging no changes are necessary, so that the change to the ecologically advantageous blister packaging of the invention makes no costly changes in the production process and logistics necessary.

In an advantageous embodiment of the invention, the blister pack or at least one of the foils used for this purpose is provided with a special coloring, coating or printing, for. B. with IR-absorbing or fluorescent markers, which makes it possible to identify the products of the invention in a detection process, causing them z. B. can be automatically distinguished from counterfeit counterfeit products, but can also be separated automatically from other garbage after use.

The blister pack of the invention can be used for a wide variety of contents, since the blister and cover sheets can be made very flexible and, as described below, can independently have one or more functional layers. Thus, it is even possible to package contents, which is a thin or viscous preparation, in particular oils or creams, it being preferred that this preparation not more than about 50% by weight of water, especially not more than about Contains 20% by weight of water. Usually, oils or creams are placed in a gelatin capsule of hard or soft gelatin for ease of handling before being placed in the blister package as an overwrap.

According to the nature of a blister pack, it is preferred if it is the contents and something solid, so z. As a tablet or a hard or soft capsule, wherein blister and cover film are preferably designed so that the hardness of the contents is sufficient to pierce the cover sheet when pressure is exerted by the blister sheet.

The fact that the properties of the blister pack of the invention despite their biodegradability can be adjusted to a high degree flexible, the package is particularly suitable for high quality products with high demands on the protective effect and in which the customer often expects a sustainable and or biodegradable packaging. The packaging is thus particularly suitable for products from the pharmaceutical sector, especially for self-paid drugs (so-called OTC, Over The Counter medicines), the field of nutritional supplements, eg. For vitamins and cosmetics.

For the invention, it is preferable to produce as many elements or layers of the blister packaging from biopolymers. For the purposes of the invention, the term "biopolymer" refers, on the one hand, to any polymer which is either obtained essentially from renewable raw materials, irrespective of whether it is biodegradable or not, and, on the other hand, any polymer which is biodegradable, even if of purely synthetic origin is.

Biopolymers suitable for the invention are e.g. B. the biopolymers described in the book "Technical Biopolymers" by Hans-Josef Endres and Andrea Siebert-Raths (2009) according to the definition given in this book and the specific examples of such polymers listed therein.

For the invention, particularly advantageous biopolymers z. Starch, modified starch, polylactic acid (PLA), chitosan, biodegradable polymers of petroleum, e.g. B. Ecoflex BASF and blends or copolyester containing these polymers, eg. B. Mater-Bi from Novamont or Bio-Flex / Bi-OPL from the companies Derlemans and FkuR, FibreForm from Billerud and SARAH from BioLog.

Biodegradable in the context of the invention is to be understood as meaning a material which can be degraded by microorganisms and / or enzymes, which degradation preferably lasts for a maximum of about one year, in particular not more than about 6 months and more preferably not more than about 2 months. Preferably, this degradation is possible without pretreatment, but it also includes materials that are suitable for biodegradation z. B. must be pretreated mechanically, chemically or by irradiation.

In a particularly preferred embodiment of the invention are biodegradable materials that are compostable, preferably according to the Standard DIN EN 13432 and particularly preferably in a modification of this standard, so that the composting is completed after a maximum of about 2 months, in particular a maximum of about 6 weeks.

Foils made from starch, in particular from corn starch, and from modified starch have proven particularly suitable for rapid composting. Particularly advantageous are films from Plantic, z. B. type HP1. Such films are also particularly suitable in connection with products having a high water activity of more than 0.50. In the context of the invention, a non-biodegradable material is therefore to be understood as meaning a material which does not fulfill any of the abovementioned definitions.

• (i) Wasserlöslichkeit, wenn weitere Schichten dennoch eine ausreichende Feuchtestabilität erzeugen. Durch die Wasserlöslichkeit – z. B. nach einer Vorbehandlung des Gesamtaufbaus – wird ein besonders schneller biologischer Abbau ermöglicht.
• (ii) Hohe Transparenz, bevorzugt wenigstens ungefähr 90%, insbesondere wenigstens ungefähr 95%.
• (iii) Antistatisch bzw. geringe Tendenz zur statischen Aufladung.
• (iv) Barrierewirkung z. B. gegen Geruchsstoffe (Aromen) und Gase wie Sauerstoff, Kohlendioxid und Wasserdampf schon ohne zusätzliche Beschichtung. Eine hierfür besonders geeignete Folie ist der Typ R1 der Firma Plantic.
• (v) Gute Thermoformbarkeit, Versiegelbarkeit und Verklebbarkeit u. a. durch nicht zu hohe Erweichungstemperaturen (T_m) von bevorzugt mindestens ungefähr 80°C und maximal ungefähr 175°C, insbesondere mindestens ungefähr 100°C und maximal ungefähr 150°C und besonders bevorzugt mindestens ungefähr 120°C und maximal ungefähr 140°C. Bevorzugte Glasübergangstemperaturen liegen bei mindestens ungefähr 10°C und maximal ungefähr 100°C, insbesondere mindestens ungefähr 25°C und maximal ungefähr 80°C und besonders bevorzugt bei mindestens ungefähr 35°C und maximal ungefähr 60°C.
• (vi) Gute Resistenz gegen Öl.

Further advantageous selection criteria for biopolymers of the invention are:

• (i) water solubility when other layers still produce sufficient moisture stability. By the solubility in water - z. B. after a pretreatment of the overall structure - a particularly rapid biodegradation is possible.
• (ii) High transparency, preferably at least about 90%, especially at least about 95%.
• (iii) Antistatic or low tendency to static charge.
• (iv) barrier effect e.g. B. against odors (flavors) and gases such as oxygen, carbon dioxide and water vapor already without additional coating. A film which is particularly suitable for this purpose is the type R1 from Plantic.
• (v) Good thermoformability, sealability and adhesiveness, inter alia, by not too high softening temperatures (T _m ) of preferably at least about 80 ° C and at most about 175 ° C, especially at least about 100 ° C and at most about 150 ° C and more preferably at least about 120 ° C and maximum about 140 ° C. Preferred glass transition temperatures are at least about 10 ° C and at most about 100 ° C, especially at least about 25 ° C and at most about 80 ° C, and more preferably at least about 35 ° C and at most about 60 ° C.
• (vi) Good resistance to oil.

Particularly preferred are materials that can be produced at least partially from renewable natural materials, such as. As starch, in particular corn starch and modified corn starch.

In a preferred embodiment of the invention, the biocarrier is a film whose dry mass is at least 50% by weight, preferably at least 80% by weight and in particular at least 95% by weight or even 98% by weight. , based on renewable resources. The raw materials can be largely unchanged or at least partially chemically modified. A particularly preferred renewable raw material for the invention is starch, in particular corn starch.

A particularly thin and homogeneous polymer barrier layer, which also acts as a barrier layer after thermoforming, could be achieved on corn starch and modified corn starch. As biocarriers, films of Plantic have proven to be particularly suitable, which are based on corn starch, especially those of the type HP1.

In a further embodiment, the biodegradable plastic is PLA or another polyester which is preferably already certified for degradability. PLA is particularly suitable for the production of Bioblister films, which decompose slowly, ie for products with a very long shelf life and / or for wet and especially humid (eg tropical) storage conditions.

Particularly high demands are made on the blister film of the invention, also referred to below as bioblister film; despite the very thin polymer barrier layer, it must have a good protective action against moisture and oxygen even after deep drawing.

Blister foils suitable for the invention are thus thermoformable and consist of a carrier film suitable therefor and at least one polymer barrier layer applied thereon, it being possible for the barrier layer to be applied directly or by intermediate layers to the carrier film separately.

In the context of the invention, it is substantially deep-drawable that the film must be thermoformable in the appropriate depth and shape for the respective filling material so that it continues to fulfill the requirements of the respective filling material to the packaging, for. B. adequate mechanical stability and / or certain barrier effects. This can be done by a person skilled in the art by means of appropriate deep-drawing experiments and subsequent tests, for. B. the Durchdrückverhaltens or the water vapor permeability can be determined.

The bioblister foil is preferably a biocarrier which is coated on one or both sides and has at least one polymer barrier layer. Optionally, the biocarrier is provided with one or more further layers, which may be one or more barrier layers and / or other functional layers, as described further below.

The thickness of the biocarrier is preferably from about 20 μm to about 600 μm, in particular from 50 μm to 400 μm. Thickness is materially dependent on the desired drawability and suitable values can be determined by one of ordinary skill in the art by conventional experimentation. The thicker the biocarrier is, the deeper it can be pulled.

The blister foil is preferably transparent, but may also contain or be coated with soluble dyes or pigments, if this is desired for optical reasons or to protect the filling material from light.

Some suitable materials of the invention of natural origin are already colored by itself and can, for. B. yellowish to brownish. In addition, the coatings of the blister carrier film may cause the overall structure to become milky or completely impermeable. Such embodiments of the invention are thus particularly suitable for photosensitive filling. In addition, it is possible to make the film less transparent to individual areas (for certain wavelengths) of infrared, visible, or ultraviolet light with filter dyes.

Suitable blister carrier films are available both undyed and dyed. This is true for. B. to the films of the company Plantic particularly suitable for the invention.

If the coatings of the blister carrier film at a given layer structure cause the overall structure to become undesirably milky or completely impermeable, a clearer film can be obtained by surface smoothing by known methods.

• (i) Schichtaufbau nur mit einer Polymersperrschicht.
• (i-2) Polymersperrschicht:Material:Polyolefin, bevorzugt PE, bevorzugt extrudiert; Schichtdicke bevorzugt ungefähr 8 μm bis ungefähr 15 μm.
• (i-i) Bioträger: bevorzugt Stärkefolie; Dicke bevorzugt ungefähr 50 μm bis ungefähr 300 μm.
• (ii) Schichtaufbau mit gegossener Barriereschicht zwischen Bioträger und Polymersperrschicht.
• (ii-3) Polymersperrschicht:Material:Polyolefin, bevorzugt PE, bevorzugt extrudiert; Schichtdicke bevorzugt ungefähr 8 μm bis ungefähr 15 μm.
• (ii-2) Gegossene Funktionsschicht, z. B. Barriereschicht gegen Sauerstoff und Wasserdampf; Trockenschichtdicke bevorzugt von ungefähr 0,1 μm bis ungefähr 20 μm.
• (ii-1) Bioträger: bevorzugt Stärkefolie; Dicke bevorzugt ungefähr 50 μm bis ungefähr 300 μm
• (iii) Schichtaufbau mit gegossener Barriereschicht auf der „offenen” Seite der Stärkefolie.
• (iii-3) Polymersperrschicht:Material:Polyolefin, bevorzugt PE, bevorzugt extrudiert; Schichtdicke bevorzugt ungefähr 8 μm bis ungefähr 15 μm.
• (iii-1) Bioträger: bevorzugt Stärkefolie; Dicke bevorzugt ungefähr 50 μm bis ungefähr 300 μm
• (iii-2) Gegossene Funktionsschicht, z. B. Barriereschicht gegen Sauerstoff und Wasserdampf; Trockenschichtdicke bevorzugt von ungefähr 0,1 μm bis ungefähr 20 μm.
• (iv) Schichtaufbau mit gegossener Barriereschicht auf der Polymersperrschicht.
• (iv-3) Gegossene Funktionsschicht, z. B. Barriereschicht gegen Sauerstoff und Wasserdampf; Trockenschichtdicke bevorzugt von ungefähr 0,1 μm bis ungefähr 20 μm.
• (iv-2) Polymersperrschicht:Material:Polyolefin, bevorzugt PE, bevorzugt extrudiert; Schichtdicke bevorzugt ungefähr 8 μm bis ungefähr 15 μm.
• (iv-1) Bioträger: bevorzugt Stärkefolie; Dicke bevorzugt ungefähr 50 μm bis ungefähr 300 μm.
• (v) Schichtaufbau mit gegossener Barriereschicht auf beiden Seiten des Bioträgers.
• (v-4) Polymersperrschicht:Material:Polyolefin, bevorzugt PE, bevorzugt extrudiert; Schichtdicke bevorzugt ungefähr 8 μm bis ungefähr 15 μm.
• (v-2) Gegossene Funktionsschicht, z. B. Barriereschicht gegen Sauerstoff und Wasserdampf; Trockenschichtdicke bevorzugt von ungefähr 0,1 μm bis ungefähr 20 μm.
• (v-1) Bioträger: bevorzugt Stärkefolie; Dicke bevorzugt ungefähr 50 μm bis ungefähr 300 μm.
• (v-3) Gegossene Funktionsschicht, z. B. Barriereschicht gegen Sauerstoff und Wasserdampf; Trockenschichtdicke bevorzugt von ungefähr 0,1 μm bis ungefähr 20 μm.
• (vi) Schichtaufbau mit beidseitiger Polymersperrschicht.
• (vi-2) Polymersperrschicht: Material: Polyolefin, bevorzugt PE, bevorzugt extrudiert; Schichtdicke bevorzugt ungefähr 8 μm bis ungefähr 15 μm.
• (vi-1) Bioträger: bevorzugt Stärkefolie; Dicke bevorzugt ungefähr 50 μm bis ungefähr 300 μm.
• (vi-3) Polymersperrschicht:Material:Polyolefin, bevorzugt PE, bevorzugt extrudiert; Schichtdicke bevorzugt ungefähr 8 μm bis ungefähr 15 μm.
• (vii) Schichtaufbau mit beidseitiger Polymersperrschicht und beidseitig gegossener Barriereschicht.
• (vii-4) Polymersperrschicht:Material:Polyolefin, bevorzugt PE, bevorzugt extrudiert; Schichtdicke bevorzugt ungefähr 8 μm bis ungefähr 15 μm.
• (vii-2) Gegossene Funktionsschicht, z. B. Barriereschicht gegen Sauerstoff und Wasserdampf; Trockenschichtdicke bevorzugt von ungefähr 0,1 μm bis ungefähr 20 μm.
• (vii-1) Bioträger: bevorzugt Stärkefolie; Dicke bevorzugt ungefähr 50 μm bis ungefähr 300 μm.
• (vii-3) Gegossene Funktionsschicht, z. B. Barriereschicht gegen Sauerstoff und Wasserdampf; Trockenschichtdicke bevorzugt von ungefähr 0,1 μm bis ungefähr 20 μm.
• (vii-5) Polymersperrschicht:Material:Polyolefin, bevorzugt PE, bevorzugt extrudiert; Schichtdicke bevorzugt ungefähr 8 μm bis ungefähr 15 μm.

Examples of preferred structures (layer sequences) for blister sheets of the invention and methods for their preparation are given below. The order numbers indicated in Arabic numerals Order of the layers is to be regarded only as an example and can be varied as desired.

• (i) Layer construction only with a polymer barrier layer.
• (i-2) Polymer barrier layer: Material: polyolefin, preferably PE, preferably extruded; Layer thickness preferably about 8 microns to about 15 microns.
• (ii) biocarrier: preferably starch foil; Thickness preferably about 50 μm to about 300 μm.
• (ii) Layer structure with cast barrier layer between biocarrier and polymer barrier layer.
• (ii-3) Polymer barrier layer: Material: polyolefin, preferably PE, preferably extruded; Layer thickness preferably about 8 microns to about 15 microns.
• (ii-2) Cast functional layer, e.g. B. barrier layer against oxygen and water vapor; Dry film thickness preferably from about 0.1 μm to about 20 μm.
• (ii-1) Biocarrier: prefers starch foil; Thickness preferably about 50 μm to about 300 μm
• (iii) Layered structure with cast barrier layer on the "open" side of the starch foil.
• (iii-3) Polymer barrier layer: Material: polyolefin, preferably PE, preferably extruded; Layer thickness preferably about 8 microns to about 15 microns.
• (iii-1) Biocarrier: prefers starch foil; Thickness preferably about 50 μm to about 300 μm
• (iii-2) Cast functional layer, e.g. B. barrier layer against oxygen and water vapor; Dry film thickness preferably from about 0.1 μm to about 20 μm.
• (iv) Cast barrier layer layer construction on the polymer barrier layer.
• (iv-3) Cast functional layer, e.g. B. barrier layer against oxygen and water vapor; Dry film thickness preferably from about 0.1 μm to about 20 μm.
• (iv-2) Polymer barrier layer: Material: polyolefin, preferably PE, preferably extruded; Layer thickness preferably about 8 microns to about 15 microns.
• (iv-1) Biocarrier: prefers starch foil; Thickness preferably about 50 μm to about 300 μm.
• (v) Layered structure with cast barrier layer on both sides of the bio-carrier.
• (v-4) Polymer barrier layer: Material: polyolefin, preferably PE, preferably extruded; Layer thickness preferably about 8 microns to about 15 microns.
• (v-2) Cast functional layer, e.g. B. barrier layer against oxygen and water vapor; Dry film thickness preferably from about 0.1 μm to about 20 μm.
• (v-1) Biocarrier: prefers starch foil; Thickness preferably about 50 μm to about 300 μm.
• (v-3) Cast functional layer, e.g. B. barrier layer against oxygen and water vapor; Dry film thickness preferably from about 0.1 μm to about 20 μm.
• (vi) Layer structure with double-sided polymer barrier layer.
• (vi-2) Polymer barrier layer: Material: polyolefin, preferably PE, preferably extruded; Layer thickness preferably about 8 microns to about 15 microns.
• (vi-1) Biocarrier: prefers starch foil; Thickness preferably about 50 μm to about 300 μm.
• (vi-3) Polymer barrier layer: Material: polyolefin, preferably PE, preferably extruded; Layer thickness preferably about 8 microns to about 15 microns.
• (vii) Layer construction with polymer barrier layer on both sides and barrier layer cast on both sides.
• (vii-4) Polymer barrier layer: Material: polyolefin, preferably PE, preferably extruded; Layer thickness preferably about 8 microns to about 15 microns.
• (vii-2) Cast functional layer, e.g. B. barrier layer against oxygen and water vapor; Dry film thickness preferably from about 0.1 μm to about 20 μm.
• (vii-1) Biocarrier: prefers starch foil; Thickness preferably about 50 μm to about 300 μm.
• (vii-3) Cast functional layer, e.g. B. barrier layer against oxygen and water vapor; Dry film thickness preferably from about 0.1 μm to about 20 μm.
• (vii-5) Polymer barrier layer: Material: polyolefin, preferably PE, preferably extruded; Layer thickness preferably about 8 microns to about 15 microns.

The cover sheet of the invention fulfills high requirements, which initially appeared incompatible.

For a preferred embodiment of the invention, standard compostability is critical, the entire package must not contain more than about 5% by weight of non-degradable materials. This is not feasible with conventional cover sheets made of aluminum because of their thickness and the specific gravity of aluminum.

In a preferred embodiment of the invention, the cover sheet of coated paper, wherein the coating can be made on one or both sides and each one or more layers. At least one of the layers applied to the paper preferably acts as a polymer barrier layer. Optional further layers may be barrier layers and / or other functional layers. In the functional layers, it may be z. B. adhesive layers, a particularly good printable layer, a print, a pigment-containing layer and / or other layers act.

Advantageous papers are z. B. papers with a low basis weight of preferably about 20 g / m ² to about 70 g / m ² , in particular from about 30 g / m ² to about 50 g / m ² , the one or two sides with z. Polyethylene or a biodegradable polymer in a thickness of preferably about 1 μm to about 50 μm, in particular may be coated in a thickness of about 5 microns to about 10 microns. The properties required for throughput correlate with physical measured values of the "Scottbond" split strength and the tear propagation resistance. These depend especially on the fiber length, the sizing and the bursting resistance of the paper.

During manufacture of the finished, usually filled package, the blister sheet is bonded to the cover sheet. This can be done by known and familiar to those skilled in the art.

Preferably, the cover sheet is brought into close contact with the blister film at high temperature, the so-called sealing temperature, under pressure, forming an intimate connection.

In the case of one-sided with a polymer barrier layer, for. B. of PE, polypropylene (PP) or a blend or a copolymer of PE and PP coated bio blister films good adhesion of paper on this layer can be achieved only at very high sealing temperatures, whereby the Bioblisterfolie can become brittle and thus no longer so easily durchdrückbar.

It is therefore preferred to join the paper foil to the side of the bioblister foil which has at least on the outside no polymer barrier layer. It is particularly advantageous to connect the paper foil directly to an uncoated side of the biocarrier. In this case, already sealing temperatures below about 150 ° C and sealing times below about 2 seconds may be sufficient to give good adhesion. This results in a blister pack with particularly good Durchdrückbarkeit.

In a further embodiment, the carrier of the cover sheet is made of paper and is provided with a biodegradable plastic extrusion layer. Because of the biodegradability of this layer, a greater layer thickness can be set than in the case of PE, whereby a satisfactory water vapor barrier effect can be achieved.

The water vapor permeability of the coversheet is preferably less than about 30 g / (m ² · d) at 38 ° C and 90% r. F., especially less than about 15 g / (m ² · d) at 38 ° C and 90% r. F., and more preferably less than about 5 g / (m ² · d) at 38 ° C and 90% r. F. and for moisture-sensitive products a maximum of about 2 g / (m ² · d) at 38 ° C and 90% r. F., in particular at most about 1.4 g / (m ² · d) at 38 ° C and 90% r. F., and more preferably at most about 1 g / (m ² · d) at 38 ° C and 90% r. F ..

The cover film can also be constructed like the blister film, only the cover film and in particular the cover carrier film must be much thinner, since it only serves to seal the packaging and must be pierceable without excessive force. In this embodiment, it is preferred if the top carrier sheet is starch, modified starch or chitosan.

In a further embodiment of the invention, the cover backing film is made of aluminum or coated aluminum, the proportion of aluminum being less than about 5% by weight, based on the dry weight of the entire package. Only in this embodiment is it possible to achieve the requirement with regard to compostability. Since the corresponding aluminum foil is very thin, preference should be given to using particularly homogeneously produced foils with little variation in thickness, which are characterized by a relatively high stability and absence of microholes.

The coversheets of the invention may also be metallised, preferably by sputtering with aluminum. This will u. a. a better oxygen and if necessary. Aroma protection achieved, as well as a more efficient water vapor barrier effect. The cover sheets may be coated instead of the metallization or in combination therewith also with a lacquer which causes an aluminum-like appearance, or further improves the barrier properties of the cover foil.

For the invention suitable cover films or carrier foils for this are, for. As well as Hostaphan films from Mitsubishi, z. Hostaphan RPSE / RPSM films. Such films are preferably duplex laminates of PE and polyethylene terephthalate (PET) or triplex laminates of PE, PET and aluminum.

Further suitable for the invention cover films or carrier films for this are, for. B. Hostaphon RHBY films, and generally films based on PE, PLA, PET, polyvinylidene chloride (PVDC), ethylene-vinyl alcohol copolymers (EVOH) and polyvinyl alcohol (PVOH), preferably with ceramic layers based on SiO _X and / or AlO _{X are} provided. Such layers provide a high barrier effect without adversely affecting the properties of the carrier.

In a further advantageous embodiment of the material, the cover carrier film is based on its dry weight to at least about 50 wt .-%, preferably at least about 80 wt .-% and particularly preferably at least 95 or even 98 wt .-% of non-biological degradable material. This can be specific Offer applications, if otherwise the cover sheet would decompose too fast because of their small thickness, z. B. in a very humid environment and / or for very long storage times. The cover film based on an aluminum cover carrier film described above is a suitable variant thereof.

Particularly preferred cover sheets of the inventions are at least partially, preferably at least about 50, preferably at least about 80, and more preferably at least about 95 or even 98 weight percent biodegradable.

Cover films are often z. B. for promotional purposes, to identify the contents and to limit possible counterfeiting printed. The outer side of the cover film lying outside in the finished packaging is therefore preferably printable. In a preferred embodiment of the invention, the cover sheet is printable with a laser printer and / or an inkjet printer.

By printing and subregions of the cover sheet can be modified, for. B. an adhesive layer can be covered by partial printed siliconization, so that the uncovered edge continue bonding is possible, but the contents do not get in contact with the adhesive.

In addition to printing, as already described in the case of the blister film, the cover film itself may be dyed and pigmented, it being possible for the dyes and pigments to be contained directly in the cover carrier film or to be applied with a coating. It is particularly advantageous to produce on the visible side of the cover sheet a metallic appearance, which connects the consumer with high-quality sealed products. This can be z. B. by pearlescent and / or metal pigments are achieved, which are preferably applied as liquid, in particular as aqueous preparations on the cover sheet.

Cover films suitable for the invention are preferably heat-sealable and firmly adhering, but may also be peelable for certain applications.

In an advantageous embodiment, the hot-melt adhesive layer independently contains no organic solvent, is odorless and free of substances that can contaminate the contents.

The polymer barrier layer of the invention may consist predominantly of biodegradable or non-biodegradable material. Their function is, in particular, to protect the generally moisture-sensitive carrier films of the invention at least on one side against moisture and thereby not hinder their biodegradability too much. In a suitable embodiment, a very good water vapor and oxygen barrier effect is already effected by the barrier layer. However, in addition to at least one polymer barrier layer, the blister and / or cover films preferably also have at least one functional layer, which is particularly preferably applied directly to the polymer barrier layer as an aqueous solution. In this case, the polymer barrier layer also allows the use of highly dilute aqueous solutions and / or high wet layer thicknesses for the functional layer (s) that would lead to problems when applied directly to the moisture-sensitive carrier film, such. B. too strong corrugations.

Polymer barrier layers may be applied to both the blister sheet and the cover sheet as one or more layers, respectively, and may be done independently of each other on one or both sides. The layers can be applied independently of each other by known methods on the carrier film, for. B. cast as a liquid composition, extruded as a melt, laminated as a film or vapor-deposited on the gas phase.

Polymer barrier layers consist essentially of one or more polymers, preferably for this alone or in blends z. As PE, PP, PET, PLA, polycarbonate (PC), polystyrene (PS) and polymethyl methacrylate (PMMA), in particular PE and PP and more preferably PE.

In a preferred embodiment, at least one barrier layer is extruded as a very thin layer, wherein it has surprisingly been found within the scope of the invention that layers having a thickness of only about 1 .mu.m to about 20 .mu.m, preferably of about 3 .mu.m, extend to the biocarriers of the present invention about 15 microns, and more preferably from about 5 microns to about 12 microns can be applied, which are still homogeneous enough to achieve a good barrier effect. The layers obtained in this way are distinguished by good adhesion and transparency and are readily deep-drawable without losing their blocking effect. Based on the mass of the biocarrier, the mass of the polymer barrier layer should preferably be less than about 10% by weight, more preferably less than about 5% by weight and most preferably less than about 3% by weight.

Because the polymer barrier layer can be very thin, the entire biocarrier-coating material is still biodegradable, even if the coating material is not biodegradable.

This is possible with the known extrudable plastics and the known extrusion methods, if restrictions with respect to homogeneity of the coating and thus reproducibility of the barrier effect are acceptable, but preferred embodiments have been found, which are described below.

In a preferred embodiment, the extrusion is conducted so that the extrudate, after exiting the extruder slot, still travels at least about 5 mm, preferably at least about 10 mm, and more preferably at least about 20 mm, freely through the air before impacting the biopatient it is preferred that the extrudate moves downwards at least part of the way through gravity before it encounters the biofiber. Due to the moving biocarrier, the extrudate is entrained and stretched, whereby the desired very thin homogeneous layer is obtained. The layer thus applied leads, in particular in the case of a biocarrier, to a dramatic improvement in its moisture stability and its barrier action against water vapor and oxygen.

The polymer barrier layer can be applied as a single layer as an extrudate, but also as a coextrudate of several layers, preferably as a coextrudate of 2 or 3 layers. Each of the coextruded layers may independently have the same or different polymer compositions. In addition, for each of the coextruded layers, the same polymer mass can be extruded, but it is preferred if the mass per layer decreases starting from the support side. Coextruded layers particularly preferably have the following layer thicknesses, layer A being closest to the biocarrier, layer B being directly coextruded thereon and layer C, if present, coextruded directly on layer B:
Layer A: about 6 to about 60 g / m ²
Layer B: about 2 to about 20 g / m ²
Layer C: about 1 to about 10 g / m ²

If very thin layers are to be extruded, layer A can also be dispensed with.

For the extrusion are conventional thermoplastic polymers, eg. PE, PP, PET, PLA, PC, PS, PMMA, PVOH and EVOH and blends and copolymers thereof. As a material particularly suitable for the polymer barrier layer, polyethylene (PE) has been found.

PE can also be thermoformed much easier by its low softening temperature T _m and thermally welded or glued together as other in principle also suitable plastics, such. Eg PET. In a preferred embodiment of the invention, at least two, in particular at least three of the following PE variants are mixed in order to obtain a material which is optimal for the polymer barrier layer of the invention:
Linear Low Density PE (LLDPE): T _m approx. 45 to 125 ° C
Low Density PE (LDPE): T _m approx. 105 to 125 ° C, T _g approx. 80 ° C
High Density PE (HDPE): T _m approx. 130 to 145, T _g approx. 100 ° C

The mixing is carried out according to methods known to those skilled in the art, the T _m value of the mixture resulting from the mixing ratio.

It is preferable that the resulting mixture has a T _m which is similar to T _{m of} the carrier film. In an advantageous embodiment, the T _{m of} the carrier film is not more than about 40 ° C, in particular not more than about 25 ° C and more preferably not about 15 ° C higher or lower than the T _{m of} the carrier film.

In another preferred embodiment, the T _{m of} the mixture is between about 80 ° C and about 145 ° C, preferably between about 100 ° C and about 140 ° C, and more preferably between about 110 ° C and about 135 ° C.

Such mixtures give a good adhesion to the carrier film and thus a good thermoformability without thermally stressing the carrier film too much.

The extruded PE layer comprises a thickness range of approximately 1 μm to approximately 20 μm, preferably a thickness range of approximately 5 μm to approximately 15 μm, and particularly preferably a thickness range of approximately 5 μm to approximately 12 μm.

Instead of using conventional PE, it is preferable for the invention because of the CO ₂ balance to use bio-PE.

In a further preferred embodiment of the invention, biodegradable thermoplastics with sufficient moisture stability and water vapor barrier effect for the polymer barrier layer are used alone or in admixture, for. B. Copolyester BASF, which are available under the brand name Ecoflex.

• (i) Wenigstens eine der Polymersperrschichten auf der Trägerfolie ist sehr dünn, bevorzugt dünner als ungefähr 3 μm, insbesondere dünner als ungefähr 1 μm und besonders bevorzugt dünner als ungefähr 0,5 μm.
• (ii) Es werden Polymerblends von PE mit wenigstens einem bioabbaubaren Biopolymeren, insbesondere PLA, für die Polymersperrschicht verwendet, wenn die damit verbundenen Nachteile für die Barrierewirkung akzeptiert werden können.
• (iii) Es wird fotoaktives TiO₂ in die PE-Beschichtung eingebracht, was eine Vorbehandlung der damit hergestellten Blisterverpackung mit geeignetem Licht notwendig macht, bevor die eigentliche Kompostierung durchgeführt wird.
• (iv) Das Material wird für Verpackungen verwendet, die dafür vorgesehen sind vor der Einbringung in die Kompostieranlage z. B. durch Häckseln zerkleinert zu werden.
• (v) Die entsprechend hergestellte Blister- und/oder Deckfolie oder die daraus hergestellte Verpackung werden mit einem Werkzeug, z. B. mit einer Nadelwalze, das kleinste Schichtverletzungen der PE-Beschichtung verursacht, behandelt.

In a further embodiment of the invention, a polymer barrier layer is applied either directly or by one or more functional layers separately on both sides of a carrier film for the blister and / or cover film. Nevertheless, to obtain a biodegradable film and thus a biodegradable packaging made therefrom, For example, the following embodiments (i) to (v) may be practiced alone or in any combination.

• (i) At least one of the polymer barrier layers on the carrier film is very thin, preferably thinner than about 3 μm, in particular thinner than about 1 μm, and more preferably thinner than about 0.5 μm.
• (ii) Polymer blends of PE with at least one biodegradable biopolymer, in particular PLA, are used for the polymer barrier layer, if the associated disadvantages for the barrier effect can be accepted.
• (iii) Photoactive TiO _{2 is introduced} into the PE coating, which necessitates pretreatment of the blister pack with suitable light produced therewith, before the actual composting is carried out.
• (iv) The material shall be used for packaging intended to be placed in the composting plant, e.g. B. to be crushed by chopping.
• (v) The blister foil and / or coversheet produced therefrom, or the packaging made therefrom, are filled with a tool, e.g. B. with a needle roller, which causes the smallest layer damage to the PE coating treated.

In addition to the extrusion process preferred for the invention for the application of a polymer layer, this is also possible with other methods if it is possible to tolerate losses in terms of quality. Thus, the polymer layer can also by a pouring, z. B. of polymer dispersions are applied. However, this is only possible if the biocarrier is not sensitive to the liquid medium of the dispersion, preferably water, and / or the proportion by weight of this liquid medium in the dispersion is sufficiently low.

In an advantageous embodiment of the invention, the cover film and / or the blister foil have further functional layers. Such functional layers, similar to the polymer barrier layer of the invention, may have a barrier to z. As water vapor and oxygen and thus support this effect of the polymer barrier layer. But you can also have other desired effects for the respective contents. In the context of the invention, coatings with barrier effect, insofar as they do not fall under the polymer barrier layers described above, are also referred to as barrier layers.

For barrier layers, the known materials and coating methods can be used, the z. B. are suitable for moisture, water vapor carbon dioxide and oxygen barrier layers. The person skilled in the art is able to make a selection suitable for the desired field of application.

For the invention in connection with biocarriers particularly suitable barrier layer materials and methods for their application are described below.

In an advantageous embodiment, at least one liquid composition, for. As a solution, a suspension or a dispersion applied with a defined wet film thickness on the biocarrier. This can be done directly on the carrier, but preferably on a pre-coated carrier. Particularly preferably, the casting on a polymer barrier layer, since in this way no liquid penetrates into the biocarrier. After the pouring, the liquid is largely removed, so that a thin layer with a defined so-called dry layer thickness, which is thinner than the wet layer thickness, is obtained.

As coating method, in particular the z. Example, from the production of conventional photographic materials known cascade and curtain covering process, with which more than one layer at the same time, in particular 2, 3, 4, 5, 6, 7, 8 and more than 8 layers can be poured simultaneously over each other.

In particular, in order to achieve an effective moisture barrier effect, the simultaneous application of several layers in the multi-layer casting has proven to be very beneficial. This results in higher barrier effects than if the same layers are applied in separate passes. The number of layers varies with requirements and is 2, 3, 4, 5, 6, 7, 8, as required, up to about 20 layers that can be applied simultaneously by a multiple-casting process.

The order can also with simple methods such. As the doctor blade method or spraying done.

As a solvent, water is preferred in these processes for environmental reasons and because of the reliability.

• (i) Silikate, insbesondere Lithium-, Natrium- und/oder Kaliumsilikate, bevorzugt als kolloidale alkalische Lösung (Wasserglas). Zur Verbesserung der mechanischen Eigenschaften sind im getrockneten Zustand möglichst dünne Silikatschichten bevorzugt.
• (ii) Styrol-Butadien-Dispersionen, insbesondere Styrofan- und Styronal-Dispersionen der Firma BASF und davon besonders bevorzugt der Typ Styrofan D422. Die so erhaltenen Beschichtungen eignen sich insbesondere für elastische, feuchtigkeitssperrende Beschichtungen.
• (iii) Hydrophobe Beschichtungsstoffe, bevorzugt Polyolefin-Dispersionen, z. B. von PE oder PP allein, als Blend oder als Copoolymer, die auch als Hydrophobierungsmittel verwendet werden, z. B. HYPOD der Firma Dow. Besonders geeignet sind auch Wachsdispersionen bzw. Wachsemulsionen, z. B. der Firma Additec, sowie Silikon- bzw. Polysiloxan-haltige Dispersionen bzw. Emulsionen, z. B. solche der Firma Silicona.
• (iv) Gelatine, insbesondere vernetzt, wobei verschiedene Gelatinearten und teilweise hydrolisierte Gelatinen einzeln oder in Abmischung verwendet werden könnnen. Zur Vernetzung sind die für Gelatinen bekannten Vernetzungsmittel geeignet. Zur Verringerung der Gasdurchlässigkeit z. B. von PE-haltigen Schichten ist Gelatine mit Formaldehyd bevorzugt und Gelatine zusammen mit Guanidinformaldehydharzen eignet sich besonders zur Verringerung der Wasserdurchlässigkeit von Papier.
• (v) Polyaminosaccharide, insbesondere Chitosan.
• (vi) PVOH oder EVOH allein oder als Blend.
• (vii) Polyester, insbesondere von α- bis ω-Hydroxycarbonsäuren wie PLA, Polyglykolsäure (PGA), Polyhydroxyalkanoate (PHA) und Polycaprolacton (PCL), sowie Elends und/oder Copolymere daraus.
• (viii) Cellulosederivate, z. B. Celluloseacetate, Hydroxypropylmethylcellulose (HPMC), Methylcellulose (MC), Ethylcellulose (EC), Hydroxypropylcellulose (HPC), Carboxy-methylcellulose (CMC), Mikrokristalline Cellulose (MCC), HPMC-Phthalat, HPMC-Acetat-Succinat (AQOAT) und niedrig substituierte HPC (L-HPS), z. B. von der Firma Harke.
• (ix) Acrylpolymere und Acrylcopolymere.
• (x) Ethylen-Acrylsäure-Copolymer Dispersion, insbesondere TECSEAL der Firma Trüb Emulsions Chemie, z. B. als zusätzliche Barriere- oder Primerschicht für die PE-Beschichtung. Besonders bevorzugt ist davon TECSEAL E-712.
• (xi) Sogenannte „Superabsorbent” und „Absorbent” Polymerzusammensetzungen, z. B. von Emerging Technologies inc. (ETi), insbesondere solche mit der Bezeichnung „Liqui Block”, besonders bevorzugt Liqui Block CSP.
• (xii) Aufgedampfte oder aufgesputterte Schichten, z. B. Metallisierungen, insbesondere Bedampfung mit Aluminium oder Gold.
• (xiii) Vorteilhaft können auch Barrierelacke der Firma Aktega Terra aufgebracht werden. Diese eignen sich insbesondere als Wasser absperrende Schicht, besonders bevorzugt bei Trägern auf Papierbasis oder über anderen feuchteempfindlichen Trägern oder Funktionsschichten, wenn anschließend eine wässrige Zubereitung aufgebracht werden soll. Durch die Lackschicht wird verhindert, dass Wasser in den Träger oder die Funktionsschicht(en) dringt und dort Störungen wie z. B. Wellungen hervorruft.
• (xiv) Was serdampfsperren der Firma Keim Additec, z. B. mit der Bezeichnung Ultraseal W-953.
• (xvi) Keramische Schichten, insbesondere mit den vom Fraunhofer Institut entwickelten Ormoceren, z. B. mit den Bezeichnungen ORM 4a-wb und ORM 4a. Solche Schichten enthalten bezogen auf den Feststoff bevorzugt zwischen ungefähr 0,5 g/m² bis ungefähr 5 g/m², insbesondere zwischen ungefähr 2 g/m² bis ungefähr 3 g/m² an Ormocer.
• (xvii) Schellack.
• (xviii) emulgierte Wachse, wie Bienenwachs und Carnaubawachs.

Preferred liquid, in particular aqueous barrier-active compositions comprise the following substances, which can be used alone or in any desired combination and which, depending on the compatibility, can be combined in one layer or applied in separate layers.

• (i) silicates, especially lithium, sodium and / or potassium silicates, preferably as a colloidal alkaline solution (water glass). To improve the mechanical properties as thin as possible silicate layers are preferred in the dried state.
• (Ii) styrene-butadiene dispersions, in particular styrofane and styronal dispersions from BASF and of these particularly preferably the type Styrofan D422. The coatings thus obtained are particularly suitable for elastic, moisture-barrier coatings.
• (iii) hydrophobic coating materials, preferably polyolefin dispersions, e.g. B. of PE or PP alone, as a blend or Copoolymer, which are also used as a water repellent, z. B. HYPOD Dow. Wax dispersions or wax emulsions, eg. B. the company Additec, as well as silicone or polysiloxane-containing dispersions or emulsions, eg. B. those of the company Silicona.
• (iv) Gelatin, in particular crosslinked, wherein various types of gelatin and partially hydrolyzed gelatins may be used singly or in admixture. For crosslinking, the crosslinking agents known for gelatins are suitable. To reduce the gas permeability z. B. of PE-containing layers gelatin is preferred with formaldehyde and gelatin together with guanidine-formaldehyde resins is particularly suitable for reducing the water permeability of paper.
• (v) polyaminosaccharides, especially chitosan.
• (vi) PVOH or EVOH alone or as a blend.
• (vii) polyesters, in particular of α- to ω-hydroxycarboxylic acids such as PLA, polyglycolic acid (PGA), polyhydroxyalkanoates (PHA) and polycaprolactone (PCL), and blends and / or copolymers thereof.
• (viii) cellulose derivatives, e.g. Cellulose acetate, hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), hydroxypropylcellulose (HPC), carboxymethylcellulose (CMC), microcrystalline cellulose (MCC), HPMC phthalate, HPMC acetate succinate (AQOAT) and low substituted HPC (L-HPS), e.g. B. from the company Harke.
• (ix) acrylic polymers and acrylic copolymers.
• (x) Ethylene-acrylic acid copolymer dispersion, in particular TECSEAL from Trüb Emulsions Chemie, z. B. as an additional barrier or primer layer for the PE coating. Particularly preferred is TECSEAL E-712.
• (xi) So-called "superabsorbent" and "absorbent" polymer compositions, e.g. From Emerging Technologies inc. (ETi), in particular those labeled "Liqui Block", more preferably Liqui Block CSP.
• (xii) vapor-deposited or sputtered layers, e.g. As metallizations, in particular vapor deposition with aluminum or gold.
• (xiii) Advantageously, barrier coatings from the company Aktega Terra can also be applied. These are in particular suitable as a water-barrier layer, particularly preferably in the case of paper-based or other moisture-sensitive supports or functional layers, if an aqueous preparation is subsequently to be applied. The lacquer layer prevents water from penetrating into the carrier or the functional layer (s) and there disturbances such. B. causes corrugations.
• (xiv) What serdampfsperren the company Keim Additec, z. B. called Ultraseal W-953.
• (xvi) Ceramic layers, in particular with the Ormoceren developed by the Fraunhofer Institute, eg. B. with the names ORM 4a-wb and ORM 4a. Such layers preferably contain from about 0.5 g / m ² to about 5 g / m ² , more preferably from about 2 g / m ² to about 3 g / m ² of Ormocer, relative to the solid.
• (xvii) Shellac.
• (xviii) emulsified waxes, such as beeswax and carnauba wax.

In order to be able to apply the layers in high quality using conventional casting methods, it is preferred to prepare preparations in such a way or dilute commercially available preparations that a wet application of at least 10 g / m ² , in particular of at least 20 g / m ² and especially preferably at least 30 g / m ² can be maintained.

The layer thicknesses of the cast layers depend on whether the casting material itself after DIN EN 13432 is degradable. If the gassing is degradable and / or compostable, the dry layer thickness in this regard may be arbitrarily large, z. When the cast layer is gelatin, chitosan or starch. The dry layer thickness is then to be chosen essentially so that the desired functionality is achieved.

If the packaging is to be biodegradable, care must be taken otherwise that the total amount of non-biodegradable material should be as small as possible on the finished blister pack and preferably about 10% by weight, in particular approximately 5% by weight, based on the dry weight. and more preferably about 4 wt .-% should fall below.

In a multi-layer package, the order of the layers can influence their effect and z. B. also change the adhesion of the layers on the biocarrier and each other, which in turn can affect the thermoformability. The person skilled in the art can determine the optimum sequence of the layers for the respective layer structure by means of conventional tests.

• (i) PE, insbesondere leicht mattiert, mit einer Dicke von bevorzugt ungefähr 10 μm bis ungefähr 15 μm, wenn keine hohen Anforderungen an die Schichtqualität gestellt werden.
• (ii) Biologisch abbaubares PE, z. B. von der Firma Bioplast, das den Abbau fördernde Additive enthält. Weitere Funktionsschichten, mit denen allein oder in Kombination die Blister- und/oder Deckfolien der Erfindung beschichtet sein können, werden im folgenden beispielhaft aufgeführt. Solche Schichten können mit beliebigen dafür geeigneten Verfahren aufgebracht werden.
• (i) Durch manche Beschichtungen, insbesondere durch hydrophobe Kunststoffschichten wie PE wird die Folie leicht elektrisch aufladbar, so dass eine antistatische Beschichtung vorteilhaft ist.
• (ii) In einer vorteilhaften Ausführungsform wird unterhalb der Polymersperrschicht eine einzelne Barriereschicht als nass gegossene Schicht aufgebracht, die (a) Polyvinylalkohol aufweist und die Durchlässigkeit bzgl. Sauerstoff verringern soll und/oder (b) selbstvernetzend (filmbildend) ist oder thermisch-, chemisch- oder UV-vernetzt ist.
• (iii) Flexible transparente Barrierefilme, bevorzugt PET- und PEN-basisert, z. B. der Firma 3M, insbesondere solche mit der Bezeichnung FTB 3–50, 125, 50i, 125i, 125N und 125Ni.
• (iv) Auftrag von Zusätzen, die den biologischen Abbau fördern, z. B. von Enzymen, Fotosensibilisatoren, Oxidationsmitteln oder Radikalbildnern. Bevorzugte Additive sind von den Firmen Ter Hell/Add-X Biotech unter den Bezeichnungen Addiflex A, HES, HEV, HEV-HD, HES-BOPP und HES-PVC erhältlich. Als Fotokatalysator bei Bestrahlung mit sichtbarem und/oder ultraviolettem Licht wird vorteilhaft Titandioxid eingesetzt, insbesonder ultra-feinteiliges TiO₂ mit einer Teilchengröße von ungefähr 1 μm bis ungefähr 1,2 μm, das z. B. von der Firma Kronos unter der Bezeichnung VLP 7000 erhältlich ist.
• (v) Harze, insbesondere hydrophile Harze, z. B. mit der Bezeichnung Soarnol von der Firma Nippon Gohsei. Besonders geeignete Harze ergeben Beschichtungen mit einer WVTR von maximal ungefähr 50 g/(m²·d) bei 38°C und 90% r. F., insbesondere maximal ungefähr 10 g/(m²·d) bei 38°C und 90% r. F..
• (vi) Geeignete Klebedispersionen, insbesondere für die Deckfolie.
• (vii) Duftstoffe, insbesondere in innen liegenden Schichten und/oder in verkapselter Form, so dass beim Öffnen bzw. Durchbruch der Deckfolie der Geruch freigesetzt wird, z. B. mit den Duftrichtungen Wald, Wiese oder Tanne. Die Duftstoffe verbleiben in dieser Ausführungsform bevorzugt diffusionsfest in der jeweiligen Schicht oder diffundieren bevorzugt in Richtung des Blisterhohlraums mit dem Füllgut. Die äußeren Schichten der Blisterverpackung besitzen dafür vorzugsweise eine Barrierewirkung für die jeweiligen Duftstoffe.

In a further embodiment of the invention, at least one functional layer is formed by laminating a film either directly onto the biocarrier, onto the cover film, onto a film Polymer barrier layer or another functional layer produced. The following slides are particularly suitable for this.

• (i) PE, in particular slightly frosted, with a thickness of preferably about 10 μm to about 15 μm, if no high demands are placed on the layer quality.
• (ii) biodegradable PE, e.g. B. from the company Bioplast, which contains the degradation-promoting additives. Other functional layers with which the blister and / or cover films of the invention can be coated alone or in combination are listed below by way of example. Such layers can be applied by any suitable method.
• (i) By some coatings, in particular by hydrophobic plastic layers such as PE, the film is easily electrically charged, so that an antistatic coating is advantageous.
• (ii) In an advantageous embodiment, below the polymer barrier layer, a single barrier layer is applied as a wet cast layer comprising (a) polyvinyl alcohol and reducing oxygen permeability and / or (b) self-crosslinking (film-forming) or thermal, chemical - or UV-crosslinked.
• (iii) Flexible transparent barrier films, preferably PET and PEN base, e.g. B. the company 3M, especially those designated FTB 3-50, 125, 50i, 125i, 125N and 125Ni.
• (iv) Ordering of additives that promote biodegradation, eg. Of enzymes, photosensitizers, oxidizers or free-radical formers. Preferred additives are available from Ter Hell / Add-X Biotech under the names Addiflex A, HES, HEV, HEV-HD, HES-BOPP and HES-PVC. As photocatalyst when exposed to visible and / or ultraviolet light, titanium dioxide is advantageously used, in particular ultra-fine-particle TiO ₂ having a particle size of about 1 μm to about 1.2 μm, e.g. B. from the company Kronos under the name VLP 7000 is available.
• (v) resins, especially hydrophilic resins, e.g. B. with the name Soarnol by the company Nippon Gohsei. Particularly suitable resins give coatings with a maximum WVTR of about 50 g / (m ² · d) at 38 ° C and 90% r. F., in particular at most about 10 g / (m ² · d) at 38 ° C and 90% r. F ..
• (vi) Suitable adhesive dispersions, in particular for the cover film.
• (vii) fragrances, in particular in internal layers and / or in encapsulated form, so that when opening or breakthrough of the cover sheet of the odor is released, z. B. with the scents forest, meadow or fir. In this embodiment, the fragrances preferably remain diffusion-resistant in the respective layer or diffuse preferentially in the direction of the blister cavity with the filling material. The outer layers of the blister pack preferably have a barrier effect for the respective fragrances.

In one embodiment of the invention, which may contribute to quality improvement in some coating compositions, at least one layer system of several directly overlapping layers is not cast in one pass, but at least one of these layers is separately cast and dried.

In a further embodiment of the invention, which can lead to particularly homogeneous layers, all wet layer thicknesses are at a thickness of more than 20 μm, which can be controlled via the concentrations of the casting solutions. In the case of low-viscosity casting solutions, it is preferred to use a thickener in a suitable amount for the casting.

In a first exemplary embodiment, a bioblast film having a barrier polymer layer has been produced in the casting process. For this purpose, a Plantic film is coated in a casting process with 18 g LDPE / m ² . The blister sheet thus obtained is deep-drawn to the coated side by about 5 cm. The film is still waterproof in the deep-drawn state. The material can be coated with an aqueous gel solution prior to deep drawing, but still shows a strong curl.

In a second embodiment, a barrier polymer layer is produced by the extrusion process. In the extrusion process, a 15 μm thick layer of PE is applied to a Plantic film. The blister sheet thus obtained is deep-drawn to the coated side by about 5 cm. The film is still waterproof in the deep-drawn state, can be coated before deep-drawing with an aqueous gel solution and shows only a small curl.

In a third example, a barrier polymer layer is prepared by the thin-film extrusion process. For this purpose, a 2 μm thick layer of a PE composition is applied by extrusion to a Plantic film. The blister sheet thus obtained is deep-drawn to the coated side by about 5 cm. The film is still waterproof when deep-drawn and contains very small amounts of non-biodegradable PE It can be coated before deep-drawing with an aqueous gel solution and shows virtually no curl.

The blister sheet is made according to Example 5, but layer 2 is omitted.

The blister foil can also be produced according to one of the preceding examples, with the difference that a 50 μm thick clear PE foil is used as the carrier instead of a paper.

A deep-drawn Bioblister foil can be welded with its uncoated side with a cover foil. In this case, a blister pack is obtained with a firmly adhering cover sheet, but the cover sheet is simply durchdrückbar only hard stuff.

The 1 to 7 show preferred embodiments of the blister sheet. It shows the 1 a layer structure without casting after extrusion. The 2 shows a layered structure with a cast barrier between a starch foil and an extruded polyolefin. The 3 shows a layer structure with cast barrier layer on the open side of the starch foil and the 4 shows a layer structure with a barrier layer on the polyethylene or the extruded polyolefin. A variant with barrier layer on both sides of the starch foil shows the 5 , A starch foil with double-sided extrusion is in 6 shown. A construction with double-sided extrusion and cast barrier layer shows the 7 ,

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2008/094451 [0008]
• WO 2006/042364 [0009]
• WO 01/54828 [0010]
• WO 99/46121 [0010]

Cited non-patent literature

• DIN EN 13432 [0012]
• DIN EN 13432 [0017]
• DIN EN 13432 [0018]
• DIN EN 13432 [0019]
• Standard DIN EN 13432 [0036]
• DIN EN 13432 [0105]

Claims (11)

Blister pack, with a blister sheet and a cover sheet, wherein the blister sheet has a deep-drawn area, and the cover sheet is connected to the blister, characterized in that the blister pack based on their dry weight at least 50 wt .-% at least one biopolymer and the blister sheet a carrier with a polymer barrier layer whose mass is based on the dry weight less than 10 wt .-% of the blister pack. Blister pack according to claim 1, characterized in that the blister pack based on the dry weight to at least 90, preferably 95 wt .-% consists of at least one biopolymer and the mass of the polymer barrier layer based on the dry weight less than 10, preferably 5 wt .-% of entire blister pack. Blister pack according to one of the preceding claims, characterized in that the biopolymer is biodegradable. Blister pack according to one of the preceding claims, characterized in that the polymer barrier layer comprises PE, PP, PLA, PC, PS, PMMA, PVOH or EVOH. Blister pack according to one of the preceding claims, characterized in that the polymer barrier layer has a thickness between 3 and 15 microns. Blister pack according to one of the preceding claims, characterized in that it comprises a cover sheet comprising a paper and a lacquer layer. Blister film for a blister pack according to one of the preceding claims, comprising a support and at least one polymer barrier layer applied thereto, characterized in that the support is a film whose dry mass comprises at least 95% by weight of a biopolymer, the mass of the polymer barrier layer based on the mass of the carrier is less than 5% by weight and the polymer barrier layer consists essentially of PE. Blister sheet according to claim 7, characterized in that the PE comprises a blend of LDPE and HDPE, wherein the T _{m of} the mixture is between 80 ° C and 145 ° C. A process for producing a blister sheet according to any one of claims 7 or 8, characterized in that the polymer barrier layer is applied to the support in an extrusion process. A process for producing a blister film according to any one of claims 7 or 8, characterized in that after the application of the barrier layer with a continuous casting process more than one layer is applied simultaneously. Use of a blister pack according to any one of claims 1 to 6 as packaging for medicines, dietary supplements or cosmetics.

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