WO2014161652A1

WO2014161652A1 - Container for a food product, beverage or pharmaceutical product

Info

Publication number: WO2014161652A1
Application number: PCT/EP2014/000865
Authority: WO
Inventors: Said Kamal FARHA
Original assignee: Cedar Advanced Technology Group Ltd.
Priority date: 2013-04-03
Filing date: 2014-04-01
Publication date: 2014-10-09
Also published as: GB201305999D0

Abstract

A container (1) comprising a dimensionally stable, hollow basic body (5) with an inner surface (2) and an outer surface (5) formed by a bottom portion (15) and a body wall (15), said bottom portion (10) and said body wall (15) being integrally made of the same material, and a liner (25) covering at least essentially the complete outer surface (3) of the body wall (15) of said hollow basic body (5). The liner (25) is a shrink sleeve film consisting of a composite of a shrinkable material and a barrier material comprising at least one liquid-crystal polymer (LCP).

Description

Container for a Food Product, Beverage or Pharmaceutical Product

The present invention refers to a container for a food product, beverage or pharmaceutical product according to claim 1, to a method for producing the container according to claim 15 and to the use according to claim 18.

It is known to manufacture plastic containers by injection molding preforms of plastic, such as polyethylene terephthalate (PET), and blow-molding the preforms in a mold cavity. The use of such plastic containers as a replacement for glass or metal containers in the packaging of beverages has become increasingly popular. The advantages of plastic packaging include lighter weight, decreased breakage as compared to glass, and potentially lower costs. The most common plastic material used in making beverage containers today is PET. Virgin PET has been approved by the FDA for use in contact with foodstuffs. Containers made of PET are transparent, thin- walled, lightweight, and have the ability to maintain their shape by withstanding the force exerted on the walls of the container by pressurized contents, such as carbonated beverages. PET resins are also fairly inexpensive and easy to process.

After molding, the resulting containers are often provided with a liner for decoration, protection and/or to provide information on the respective contained product.

Various methods have been developed for closely forming film liners wrapped around containers. The liners can include colorants, ultra-violet light protectors, absorption materials and the like, and can be applied on the inside or outside surfaces of the containers.

So-called in-mold lining procedures, for instance, encompass inserting a blank or a liner into a mold and subsequently forming the container in the mold by injection molding, blow molding, differential pressure molding, expansion molding or the like, followed by decoration on the container (see, JP-A-58-69015 and EP-B- 0254923). Such known liners for in-mold formation include resin films with gravure printing, artificial paper with multiple-colored offset printing, or aluminum liners produced by laminating high pressure low density polyethylene or ethylene-vinyl acetate copolymer on the rear face of an aluminum foil, followed by gravure printing on its front face, and the like which have already been put to practical use.

Other known methods utilize exclusively the application of heat impinging directly upon the film liner causing the liner's plastic film structure to shrink until the liner closely conforms to the container's contours - a procedure known as shrink lining.

Heat-shrink sleeves are generally constituted by a film of a single-oriented plastic material that has previously been stretched in a determined direction in order to give it a capacity for shrinkage under the effect of heat in the stretching direction. Such sleeves are used, in particular, for covering the walls of containers of all kinds . Apart from liners covering only a part of the container, so-called full-body liners or full-sleeve liners have also been developed. Thanks to such full-body liners, containers are not only provided with ample room for graphics and product information, but the liners may also be used for adding additional properties to the container material .

In particular when using PET in small, thin-walled beverage containers, permeability to gases, such as carbon dioxide and oxygen, is generally a problem: In a small bottle, the ratio of surface area to volume is large, which allows for a large surface for the gas contained within to diffuse through the walls of the bottle. The permeability of PET bottles results in soft drinks that go "flat" due to the egress of carbon dioxide, as well as beverages that have their flavour spoiled due to the ingress of oxygen. Because of these problems, PET bottles are not suitable for all uses desired by industry, and for many of the existing uses, the shelf-life of liquids packaged in PET bottles is shorter than desired. In order to improve impermeability of the container material, U.S. Pat. No. 5,464,106 describes bottles formed by blow molding preforms having a barrier layer. The barrier materials disclosed are polyethylene naphthalate, saran, ethylene vinyl alcohol copolymers or acrylonitrile copolymers. Technique, the barrier material and the material to form the inner wall of the preform are coextruded in the shape of a tube. This tube is then cut into lengths corresponding to the length of the preform, which are placed inside a mold, wherein the outer layer of the preform is injected over the tube to form the finished preform. The preform may then be blow-molded to form a bottle. The drawbacks of this method are that most of the barrier materials disclosed do not adhere well to PET, and that the process itself is rather cumbersome.

Another problem is that liners add up to the thickness of the container walls. In the state of the art, the thickness of monolayer films that are used to make shrink sleeves is usually in the range of 50 pm.

It is therefore a problem of the present invention to provide a container for a food product, beverage or pharmaceutical product that offers an efficient protection against oxygen and aroma loss, while at the same time being easily prepared and recyclable and/or biodegradable or biocompostable .

This problem is solved by the container according to claim 1, the method for its preparation according to claim 15 and the use according to claim 18. Preferred embodiments are subject of the dependent claims.

The present invention refers to a container for a food product, beverage or pharmaceutical product, comprising at least one dimensionally stable hollow basic body with an inner and an outer surface formed by a bottom portion and a body wall, said bottom portion and said body wall being integrally made of the same material. The container further comprises a liner covering at least essentially the complete outer surface of the body wall of said hollow basic body.

The basic body is made from a material selected from the group consisting of paper; cellophane; a starch-based material; and a polymer or copolymer, the polymer or copolymer being selected from the group consisting of polypropylene (PP); polyethylene (PE); polyethylene terephthalate (PET); polyethylene naphthalate (PEN); polycarbonates (PC); and mixtures thereof.

The liner of the present invention is a shrink sleeve film consisting of a composite of a shrinkable material and a barrier material comprising at least one liquid-crystal polymer (LCP) .

The materials comprised in the basic body and/or the liner will be explained in more detail below.

Cellophane is a thin, transparent sheet made from regenerated cellulose by extrusion. Cellophane is widely used as a packaging material for food items and is biodegradable. However, cellophane is moisture permeable. The starch-based materials that are suitable for the present application are generally biodegradable and/or biocompostable . In particular, starch-modified thermoplastics, such as PE or PP, can be used.

Polypropylene or polypropene, generally abbreviated as PP, is a thermoplastic polymer of the polyolefin family. Melt processing of PP can be achieved via extrusion and molding, with injection molding being the most common shaping technique. PP is recyclable and is often used for bottle tops, bottles and fittings. Polyethylene or polythene, generally abbreviated as PE, is also a thermoplastic polymer of the polyolefin family. Nowadays, PE is the most common plastic, with its primary use being within packaging. One of the main problems of PE is that without special treatment, it is not readily biodegradable .

Polyethylene terephthalate , generally abbreviated as PET, is a thermoplastic polymer resin of the polyester family. PET is a good gas and fair moisture barrier, and is often used for beverage, food and other liquid containers. However, in order to further reduce its oxygen and moisture permeability, an additional barrier layer is often required. PET is environmentally friendly since it can be recycled.

Polyethylene naphthalate or poly ( ethylene 2,6- naphthalate) , generally abbreviated as PEN, is a polyester with good barrier properties. In particular, it provides a very good oxygen and moisture barrier. Polycarbonates, generally abbreviated as PC's, are thermoplastic polymers. They are easily worked, molded and thermoformed . In particular, polycarbonates derived from bisphenol A (BPA) , are often used for preparing non-food packaging . It is to be noted that the general term for a specific material group as used above relates not only to the material in its unmodified state, but also to its known modifications. For instance, the term "PET" as used throughout this application also covers the known subgroups of modified PET materials, such as e.g. Glycol- modified PET (PET-G), Virgin-PET , iso-propyl alcohol (IPA) modified PET, p-toluene sulfonic acid (pTSA) modified PET, pyrometillic dianhydride (PMDA) modified PET or maleic anhydride modified PET. The above described materials may also be present as mixtures, such as blends of different PET's, for instance. Particularly preferred PET material mixtures are PET-based co-polyester blends, such as branched CHDM (1,4- Cyclohexanedimethanol) modified PET (PETG) or an IPA modified slower crystallizing PET, as these blends are highly suitable for extrusion processing, such as extrusion blow molding and for recycling. A specific example of such a blend is a blend of Extrusion grade EB062 Eastman PET with Eastman 9921 PET as disclosed in US 8, 080, 191 B2.

Further preferred are blends of low density polyethylene (LDPE) , recycled LDPE and/or recycled ethylene polymer, and other ethylene polymers and copolymers . With regard to the material of the liner of the present invention, it is a key aspect of the present invention that the liner contains a barrier material comprising at least one LCP.

Liquid-crystal polymers or anisotropic melt-forming polymers, generally abbreviated as LCP's, are a class of aromatic polyester polymers. They are extremely unreactive and inert, and highly resistant to fire. LCP's are sold by different manufacturers under a variety of trade names. These include: Vectran (by Ticona) , Zenite (by Ticona) , Kevlar (by DuPont), Sumikasuper (by Sumimoto Chemical Industry) or Xydar (by Solvay) .

It has been found that LCPs offer a unique combination of high barrier to oxygen, aromas, and water vapor, together with chemical resistance superior to that of conventional barrier resins like EVOH (ethylene vinyl alcohol) or PVDC (polyvinylidene chloride) . However, unlike EVOH, their oxygen barrier does not weaken with humidity, making them ideal for retort packaging at temperatures up to 120 °C. In addition, LCP is inert, stable under heat and is FDA approved for food contact.

LCP' s are therefore particularly well suited as barrier material because they provide a highly efficient moisture, oxygen and aroma barrier. Furthermore, they have a small carbon footprint, which is ecologically favorable. However, for a long time it has not been possible to obtain thin films of LCP. Only recently, a new group of LCP' s has been developed that can be extruded, thus allowing for the preparation of very thin foils. US 6, 132, 884, for instance, discloses such a new group of LCP's and is herewith incorporated by reference. Most LCP materials known so far have essentially no or very little shrinking properties. However, it has surprisingly been found that if LCPs are provided in a composite with a shrinkable material, preparation of films having both, highly effective barrier properties and shrinking capacities is possible.

It has been found that LCPs can be coextruded in standard equipment with shrinkable polymer resins. Examples of new coextruded LCP materials are Vectran LCP extrusion grades V300P and V400P or V100P and V200P. For the present invention, the LCP extrusion grades V300P and V400P are preferred as they have glass-transition temperatures of 230 F and are thermoformable in very thin films.

The present invention makes use of these findings to provide a container having a basic body and, on the outer surface of the body, having a shrinkable sleeve film consisting of a composite of a shrinkable material and a barrier material comprising at least one liquid-crystal polymer (LCP) . As mentioned above, the dimensionally stable, hollow basic body of the present invention comprises a bottom portion and a body wall. Said bottom portion and said body wall are integrally made of the same material. The liner covers essentially the whole outer surface of the body wall and, preferably also of the bottom portion. In other words, the basic body has an exterior surface that is essentially completely enveloped in a shrink sleeve film.

The term "integrally made" as used throughout this application refers to parts that form one unit. In the context of the present invention, integral parts forming one unit are made of the same material or material bond.

Preferably, between the outer surface of the body wall of the hollow basic body and the liner an adhesion promoter is present. Due to the presence of the adhesion promoter the liner has an improved adhesion to the surface of the body wall of the hollow basic body. Preferably the adhesion promoter is selected from the group of maleic anhydride, polyethermonoamine , elastamine, amine-maleated polypropylene adducts, chlorinated polyolefin, titanate, zirconate, acrylic or norbornene acid, phosphate esters, maleic acid, acrylic acid, methacrylic acid, norbornene dicarboxylic acid, fumaric acids and half acid esters and peresters of maleic fumaric and norbornene dicarboxylic acids. Best results could be obtained with maleic anhydride based polymers. The adhesion promoter may either be applied on the surface of the body wall of the hollow container or on the surface of the liner before they are brought in contact with each other. Alternatively, the basic body material may already comprise the adhesion promoter before producing the hollow container. Preferably, the basic body material comprises up to 10%, most preferably 1 to 5%, especially preferred 2 to 5% based on the total weight of the body material of such an adhesion promoter. In another embodiment of the present invention, the surface of the body wall can also be treated by corona treatment or by plasma treatment. Also a combination is possible, that is, for example a corona treatment and the presence of an adhesion promoter or a plasma treatment and the presence of an adhesion promotor.

In one embodiment, the liner is covering at least essentially the complete outer surface of the body wall of said hollow basic body, whereas the bottom portion is not or only partly covered by said liner. In another embodiment of the present invention, the liner is covering essentially the complete outer surface of both parts, i.e. the outer surface of the bottom portion and the body wall.

Thanks to the LCP in the barrier material of the liner, it is possible to achieve a high amount of barrier protection (gas-tight and preferably liquid-tight) with a very low amount of material. The liner on the basic body is therefore preferably impermeable to gas, vapour, moisture and liquids.

Preferably, the liner is sized so that the liner is the size of the outer circumference of the basic body surface where the liner will be placed. Thus, if the basic body is not cylindrical, then the liner is sized so that the liner has the equivalent size and shape of the outside shape of the basic body. In a preferred embodiment the liner conforms to the inner and/or outer surface of the basic body ensuring a tight fit. In this way, the liner becomes an integral part of the container after engagement with the basic body.

In a preferred embodiment of the present invention, the body wall of the basic body has a curved, conical, or irregular surface. In this case, the liner can readily be shrunk to conform to the surface anomalies of the body wall. This conforming capability provides an aesthetically pleasing appearance for the container. The shrinkable material is preferably a polymeric heat- shrink material, in particular selected from the group consisting of ethylene propylene diene monomer (EPDM) , polylactic acid (PLA), high heat polylactic acid (PLA) , polyethylene terephthalate (PET), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), polyhydroxyalkanoates (PHA), a starch-based polymer, a furan-based polymer, polyethylene (PE), polyethylene naphthalate (PEN), and mixtures thereof. However, the skilled person is aware of many other materials that are shrinkable and therefore can be used. The shrinkable material does not only provide the liner with the shrinkable properties but preferably also provides stabilizing properties.

The expression shrinkable within the context of the present invention stands for a material which is capable to reduce the size in response to an external factor such as by the application of heat, humidity (that is air having a water content of 40% to 80%, preferably of 40% to 60%), electrical charge, and/or UV irradiation. Preferably, after the application of said external factor the size of the label is reduced by at least 40 %, preferably by at least 50%. Most preferably the size of the label is reduced due to the shrinkage bei 50 to 90% compared to the original size. EPDM, also called EPDM rubber, is a thermoplastic polymer and finds use in many sealing applications and in particular in environments, where silicone must be avoided. It can be purchased, for instance, from Exxon Mobil under the name "Vistamax". Given the high shrinking capability of EPDM, an LCP-EPDM composite yields a highly tight shrink sleeve.

Polylactic acid or polylactide, generally abbreviated as PLA, is a thermoplastic aliphatic polyester derived from renewable resources, such as corn starch or sugarcane. PLA is available both as a single enantiomer polymer, i.e. as poly-L-lactide (PLLA) or poly-D-lactide (PDLA) , or as a mixture of the two enantiomers. PLA can be processed by extrusion, injection molding, film and sheet casting, as well as spinning. PLA can be recycled to the monomer by thermal depolymerizaton or hydrolysis. When purified, said monomer can be used for the manufacture of virgin PLA with no loss of original properties.

Purac has recently developed a special type of PLA, so- called "high heat PLA". This high heat PLA is produced by stereo-complex technology starting from D-lactide, and can withstand temperatures of up to 180 °C. For this reason, high heat PLA will not melt during the over-molding process. PLA is particularly well suited as a support for a high barrier material, such as LCP or N- XD6. Furthermore, it is preferably used for the dimensionally stable body, since it is biodegradable and even biocompostable .

Polyvinylidene chloride, generally abbreviated as PVDC, is a homopolymer of vinylidene chloride. It is a remarkable barrier against water, oxygen, and aromas.

Polystyrene, generally abbreviated as PS, is a synthetic aromatic polymer that can be rigid or foamed. It is a rather poor barrier to oxygen and water vapor, and is chemically very inert, being resistant to acids and bases. PS is commonly injection molded or extruded, with extruded PS being about as strong as an unalloyed aluminum, but much more flexible and much lighter.

Polyhydroxyalkanoates , generally abbreviated as PHA's, are biodegradable linear polyesters. They can be either thermoplastic or elastomeric materials, with melting points ranging from 40 to 180 °C. In industrial production, PEA' s are produced by microbial fermentation of sugar or glucose and extracted and purified from the bacteria. PHA's are mainly processed via injection molding, extrusion and extrusion bubbles into films and hollow bodies.

The simplest and most commonly occurring form of PHA is polyhydroxybutyrate, generally abbreviated as PHB. Thus, PHB is a bio-derived and biodegradable plastic. PHB is non-toxic and biocompatible, and is hence suitable for medical applications. Further, PHB is a relatively good oxygen barrier. PHB is preferably used in combination with a high barrier resins, such as LCP or N-MXD6 as a support. Furthermore, it is an advantageous material for the dimensionally stable body, since it is biodegradable and biocompostable .

Furan-based polymers are polyesters that emerged as renewable polymers made from sugar. The polyester is made from furan dicarboxylic acid and ethylene glycol. This polyester forms a good gas barrier.

Of the above materials, EPDM is particularly preferred due to its high shrinking capacity. PLA, PHA, starch-based polymers, and furan-based polymers are also particularly preferred because they are biodegradable and/or biocompostable.

The shrinking of the shrinkable material can be induced, for instance, by the application of heat, humidity, electrical charge, and/or UV irradiation.

In one embodiment the liner is in form of a very thin material film comprising LCP in combination with a shrinkable material. With the thin flexible film of the LCP, the standard shrinkable material will dominate the shrinking dynamics even when the LCP is added. The resulting films have a better workability and an improved stability in comparison to the previously used materials for shrink sleeve films. Also, liners comprising LCPs have the additional benefit that they can easily be separated from the material of the basic body. More specifically, the liner is preferably made from a blend of the barrier material and the shrinkable material; or from a laminate of the barrier material with the shrinkable material film; or from a coextruded film of the barrier material and the shrinkable material; or from the shrinkable material being coated with the barrier material. Preferably, the liner comprises 1 to 99, most preferably 80 to 99% by weight of the liquid crystal polymer and 1 to 99, most preferably 1 to 20% by weight of the barrier material. It was shown, that a liner comprising 80 to 99% by weight of the liquid crystal polymer maintains the key properties of a liquid crystal polymer film with regard to its unique combination of high barrier to oxygen, aromas, and water vapor, together with chemical resistance superior to that of conventional barrier resins like ethylene vinyl alcohol. In addition, it remains inert, stable under heat. However, the presence of 1 to 20% of by weight of the barrier material allows a good shrinkage of the liner and in addition it easy to be processed as well as economical, since the liquid crystal polymer is a very expensive material.

In a particularly preferred embodiment, the liner is a laminate of LCP with a film of polylactic acid (PLA) . Apart from being biodegradable and having an excellent printability, PLA has the advantage of requiring less heat to shrink the liner onto a package, which makes it suitable for a variety of shrink sleeve-packaging applications .

Preferably, the barrier material is a composite of one or more LCP(s) alone with another material. Depending on the LCP material comprised in the barrier material of the liner, it may be advantageous to enhance the properties of the liner, e.g. its toughness, barrier properties or workability by combining the LCP material with another material. If, on the other hand, the LCP material itself already has all the desired properties, it is preferably used alone in order to lower the carbon footprint and also costs .

In a preferred embodiment, the barrier material comprises at least one LCP and further comprises at least one polymer selected from the group of cross-linked thermoplastic epoxy-based polymers, Nylon-MXD6; cross- linked polyvinyl alcohol (PVOH); cross-linked ethylene vinyl alcohol (EVOH) ; polyglycolide (PGA), and mixtures thereof . Suitable cross-linked thermoplastic epoxy-based polymers include BLOX resins from Dow Plastics or the epoxy-amine barrier coatings by PPG Industries (see e.g. US 5, 637, 365) .

Nylon-MXD6 - or N-MDX6 - is a barrier resin produced by polymerization of m-xylenediamine (MXDA) and adipic acid. Nylon-MXD6 has excellent gas barrier properties, especially in high humidity conditions. In addition, it offers important processing benefits for multilayer bottle manufacture. In particular, Nylon-MXD6 is known as multi- gas barrier resin, contributing both oxygen and C0₂ barrier in PET bottles. Nano-N-MXD6 is approved for PET bottles when used as a non-contact layer in conjunction with an inner PET contact layer of 2.0 mils thickness or greater. Furthermore, Nano-N-MXD6 can be separated from PET by normal recycle methods. A combination of Nylon-MXD6 with LCP, e.g. as a laminate, results in a highly gas-, vapour- and liquid-tight barrier material that is ideal for multilayer PET construction.

Polyvinyl alcohol, generally abbreviated as PVOH, is a water-soluble synthetic polymer having excellent film forming, emulsifying and adhesive properties. It has a high tensile strength and flexibility, as well as high oxygen and aroma barrier properties. However, these properties are dependent on humidity, since more water is absorbed with higher humidity. PVOH is preferably used in combination with a suitable stabilizer, such as a PET film.

Ethylene vinyl alcohol, generally abbreviated as EVOH, is a formal co-polymer of ethylene and vinyl alcohol. The plastic resin is commonly used in food applications and has lately found some application in plastic gasoline tanks for automobiles. Its primary purpose is to provide barrier properties, primarily as an oxygen barrier for improved food packaging shelf life and as a hydrocarbon barrier for fuel tanks. EVOH is typically co-extruded or laminated as a thin layer between cardboard, foil, or other plastics.

Polyglycolide or polyglycolic acid, generally abbreviated as PGA, is a biodegradable, thermoplastic polymer. PGA has been known since 1954 as a tough fiber-forming polymer. Owing to its hydrolytic instability, however, the use of PGA has initially been limited. By combining PGA with LCP, it can be sufficiently stabilized to serve as a barrier material for food packaging. Such combinations of at least one LCP with the above mentioned materials may be prepared by co-extrusion or lamination, for instance. LCP may also be cross-linked with EVOH or PVOH, or a LCP film on an underlying shrinkable material film may be coated with SiO_x or amorphous carbon.

A suitable amorphous carbon coating provides, for instance, the "Actis" treatment developed by Sidel. This treatment involves the treatment of a surface with acetylene gas, which is then treated with microwave energy in order to reach its plasma state, and the deposition of amorphous carbon thereon. Thereby, a thin layer of hydrogen rich carbon is formed on the surface.

If the barrier material comprises LCP and one or more of the above mentioned materials, their combined barrier properties allow for reducing the thickness of the liner while maintaining the desired impermeability to gas, moisture, vapour and liquids.

It is further preferred that the liner has a thickness of less than 50 μπι, preferably of less than 25 μπι, more preferably of less than 10 μπι, and most preferably of less than 5 μιτι and ideally of less than 3 μπι. Thus, a thickness in the range of 0.1 pm to 5 pm, and in particular in the range of 0.1 μιτι to 3 μπι, is particularly preferred. As already mentioned, thanks to the special barrier material contained in the liner of the present invention, it is possible to achieve a high amount of protection with a very low amount of material.

The liner is preferably a multi-layer film. In one embodiment, the barrier material forms a film which consists of several coextruded or laminated LCP plies oriented in different directions with the shrinkable material. These films provide a particularly well oxygen and moisture barrier. In addition, the resulting films have a better processability, an improved stability, and also result in lower costs than the previously used materials for shrink sleeves.

In another embodiment, the liner is a three or five layer structure, in which each LCP layer is sandwiched between layers of the shrinkable material. An adhesive layer may optionally also be provided between two adjacent layers.

In a specific embodiment, the liner comprises a five-layer PP/LCP barrier film. An extrusion tie-layer may be used to "tie" one layer to another layer. Extrusion tie-layers may be non-reactive, such as low density polyethylene ("LDPE") and ethylene copolymers, or reactive, such as maleic anhydride grafted olefins. The barrier film is preferably a single co-extrusion of PP-tie-LCP-tie-PP with 1 to 10 μπι, preferably 5 to 10 pm of LCP in the core layer. The preparation of such thin LCP films is described in US 2011/0227247. This document is herewith incorporated by reference with regard to the method of preparation and the LCP's used. The LCP core layer then functions as a barrier layer disposed between the two tie-layers and the two outer polypropylene layers.

According to another specific embodiment, the liner comprises Cryovac 360, which is a five-layer lower-density multiple polymer film with glycol-modifed PET layers on the outside. Cryovac 360 has good optics and more flexibility than single-layer PET-G, PVC and OPS (biaxially oriented polystyrene) films.

In general, it is preferred that the liner forms only a very minor part of the container, whereas the basic body forms by far the major part of the container. In particular, the container preferably comprises no more than 8 wt% of the liner material, more preferably less than 5 wt% of the liner material, and most preferably about 2 to 3 wt%. In addition to the liner covering at least essentially the complete outer surface of the body wall of the hollow basic body, a further protection layer covering essentially at least the complete inner surface of the basic body may also be present. An inner protection layer is particularly preferred if a protection barrier between the content in the container and the material of the basic body is required.

The basic body of the container of the present invention mainly serves for providing stability. Since it forms by far the major part of the container, the basic body is preferably made from a biodegradable and/or recyclable material. This is particularly favorable from an ecologic point of view.

The wall thickness of the basic body is preferably in the range of 10 to 500 m, and more preferably 20 to 300 μπι. If the wall thickness is less than 10 m, breaking strength of the basic body becomes so low that breakage can occur. It is further preferred that the basic body is made from a thermoplastic polymer. These materials allow for simple and cost-efficient preparation of a dimensionally stable body of almost any desired shape and size. More preferably, the dimensionally stable body is formed from a thermoplastic polymer selected from the group consisting of PHA, high heat PLA, a starch-based polymer, a furan-based polymer, PE, PP, PS, PET, recycled PET, PEN, and mixtures thereof. Thermoplastic polypropylene (PP) is particularly preferred since PP has the advantage of being recyclable but lighter than PET and cheaper in production.

Recycled PET is advantageous from an ecologic point of view. However, it has not been approved for direct contact with food products. If recycled PET is used, not only essentially the outer surface of the body wall of the basic body, but also essentially the entire inner surface of the body - and thus the surface of the container that will be in contact with the food, beverage or pharmaceutical product - is covered with the liner. For covering the inner surface of the basic body, the liner may also be replaced by another food protection layer.

The container may be of a bilayered structure, or a multi- layered structure with three or more layers. In case of a multi-layered structure, an adhesive may be used for connecting the different layers to each other.

The adhesive may be applied in form of an adhesive layer positioned between and adhering to the basic body and the liner, respectively.

Preferably, the adhesive comprises a material that is the same as or similar to the basic body material. More preferably, an adhesive is chosen that has been approved for food contact is used, in particular an ethylene acrylic acid-base or polyurethane-based adhesive.

It is further preferred that the adhesive is an adhesive which can be activated by using heat, pressure, ultraviolet light and/or direct infrared irradiation such that the liner placed on top of an adhesion layer is attached to the adhesion layer, and consequently also to the basic body of the container. Most preferably, the adhesive is a heat or UV activated material.

The thickness of the adhesion layer is preferably in the range of 0.1 to 20 μπι, and more preferably 0.5 to 10 μιτι. When the thickness is less than 0.1 μιτι, insufficient adhesion force to the container is obtained, whereas curling of the liner can occur when the thickness is greater than 20 pm.

The liner of the present invention may be provided with information related to the product. This may be achieved by a printing station where information, such as text and/or graphics, may be printed on either one surface of the liner or on both surfaces of the liner. In this way, the liner may have dual purposes: both as a material with barrier properties and as a label with printed information .

In another specific example, the container can be composed of a clear plastic and an additional liner can be provided on the inside of the container. Thereby, the printing can be located on the side of the inner liner facing the outside of the container. As such, the liner could be tamper-resistant because the clear plastic is protecting the printing (e.g. this could be used in application where tamper-resistance of labels is important such as in the pharmaceutical industry) .

Various printing methods that are common in the industry may be utilized, such as offset printing, gravure printing, flexographic printing, screen printing, letterpress printing or the like. Silk screening may also be used, but is not a process that is typically used for large manufacturing quantities. However, the process of silk screening may apply a thicker layer of ink which may be desirable in certain applications. Factors considered when selecting the printing process include the desired ink thickness, viscosity of the printing inks, image to be printed, number of colours, and other operational concerns such as quantity of liners to be produced.

The liner may further include a temperature sensitive indicator, which indicates to the user a relative temperature of the exterior surface of the container. For example, the liner may indicate whether the exterior of the container is hot or cold by using one or more color- coded indicators corresponding to the relative exterior temperature of the container.

In another embodiment, the container further comprises a label which is affixed to the container and/or the liner. If the container comprises a cap or lid to close the container, such a label may also be affixed to the cap or lid. The label is preferably prepared from a material comprising at least one LPC. More preferably, the label is prepared from a composite of a plastic material and at least one LCP. The label may thus be prepared in the same way as the liner of the present invention with the difference that the label does not need to be provided with shrinking properties and can thus be prepared from LCP alone or from a composite of LCP and any suitable material, such as PET, for instance.

The label may be attached to the container and/or the liner and/or the cap or lid using an adhesive and/or an in-mold label process. It is contemplated that any suitable in-mold label process known to a person of ordinary skill in the art may be used to affix the label. The use of an in-mold label allows the manufacturer to readily and inexpensively produce labelled containers directly from the molding operation.

Exemplary in-mold label processes include injection mold process, extrusion blow mold process, and stretch blow molding. In addition, the label may further include a heat activated adhesion layer.

Before the label is attached to the container and/or the liner, information, graphics, or combinations thereof may be printed thereon. Printing on the liner or on the label is preferably followed by application of a clear top-coat over the ink to protect the ink against abrasion and other environment factors.

In another embodiment, a printed film can be co-laminated to the liner prior to adhering it to the basic body. The dimensionally stable, hollow basic body defines the shape and size of the container. The container of the present invention is generally suitable for almost all kind of food products, beverages or pharmaceutical products. Depending on the product to be stored in the container, the body may have various different shapes and sizes .

Exemplary containers of the present invention include, but not limited to, bottles, bowls, cans, jars, and any other containers capable of retaining a substance, which substance may be a solid, liquid, gas, or combinations thereof .

Additionally, the container can take the form of a variety of sizes and shapes. For example, the container can include straight walls from top to bottom (e.g., a true cylindrical container) . Alternatively, the containers can have a more complex or irregular shape.

In a preferred embodiment, the container further comprises a neck portion having an exterior-threaded sidewall, and a removable cap having an interior-threaded sidewall, the cap being dimensioned for being screwed onto the neck portion of the particular container.

In this embodiment, the neck portion of the container is generally in integral part the basic body and its outer surface may also be covered by the liner. However, the liner may also only be applied to the body wall of the basic body itself, or to the body wall and the bottom portion of the basic body, without covering the neck portion as this part is generally covered by the cap. However, the inner surface of the cap may also additionally be covered with the liner.

The removable cap is preferably adapted to close the opening of the container and may be any shape, form, or size,- so long as it is capable of closing the opening. Preferably, the cap comprises a material that is the same as or similar to the basic body material. In one embodiment, the cap may be manufactured in the same mold as the basic body of the container. Alternatively, the cap may be manufactured separately from the container body and/or may be prepared from a different material.

In a preferred embodiment, the basic body, the liner, and the adhesive comprise biocompostable or recyclable materials. More preferably, the basic body and/or the liner and preferably also the adhesive essentially consist of biocompostable or recyclable materials such that the entire container may be biocompostable and/or recyclable.

In another aspect, the present invention also refers to a method for the preparation of a container according to the present invention.

Generally, the method comprises the steps of preparing a basic body in form of the container, preparing the liner, and adhering the liner to the basic body.

More specifically, the basic body and the liner in form of a shrink sleeve are prepared separately. Subsequently, the liner is applied to the basic body by placing the liner over the basic body and shrinking the liner to conform to the basic body.

The basic body is preferably prepared by using blow molding, injection molding, lamination, co-extrusion, or thermoforraing, in particular blow molding and injection molding, of a preferably biodegradable, thermoplastic resin .

The liner is preferably prepared by lamination of the barrier material with the shrinkable material film; by co- extrusion of a film of the barrier material and the shrinkable material; or by covering, e.g. sputtering, the barrier material on the shrinkable material.

Co-extrusion is typically used for the preparation of liners comprising LCP in combination with PET, PEN or PC, e.g. in form of a blend. Preferred LCP materials used for co-extrusion are Vectran LCP extrusion grades V300P and V400P.

In order to ensure secure adherence of the liner to the basic body, an adhesive material is preferably applied at least to the outer surface of the body wall of the basic body and/or to the liner before shrinking the liner to conform to the basic body.

In a specific embodiment, the container is prepared by inserting the liner within an open mold prior to closing of the mold around an extruded hot material forming the basic body or a heated injection molded basic body.

More specifically, the liner can be roughly the same shape as the molded basic body (e. g. the liner insert can be a cylindrical shape with a closed bottom that is inside a comparably shaped cylindrical container) . Subsequent mold closing and extrusion of the hot material of the basic body forms the basic body around the liner to the shape of the mold and activates a heat sensitive adhesive provided on the basic body and/or the liner for providing a permanent bond which is substantially incapable of being broken by moisture or otherwise.

Such in-mold lining has the benefit that it provides a smooth transition between the liner and the adjacent surface of the container and may further provide additional strength since the liner cooperates with the container wall in resisting deformation. Such strengthening also allows the use of less material to mold the container and thereby reduces the ultimate cost to the consumer .

In a further aspect, the present invention also refers to the use of a material comprising at least one liquid- crystal polymer for preparing a shrink sleeve for a container for a food product, beverage or pharmaceutical product .

The present invention is further illustrated by means of the following example:

Examples A dimensionally stable, hollow basic body with an inner and an outer surface formed by a bottom portion and a body wall is prepared from PET using a blow-molding procedure.

A liner in form of shrink sleeve film consisting of a composite of EPDM and Vectran (by Ticona) is provided as a roll of tubular or shoulder formed film. The shrink sleeve film may further be prepared with any desired coloring, design, lettering, etc. For example, it may be prepared with a high-resolution advertisement. The liner is cut from the roll by a sleeve dispenser which is configured to affix the liner to the exterior surface of prepared basic body of the container using a thermal adhesive that is activated upon application of heat. After the shrink sleeve film is applied to the basic body, the basic body is conveyed through a shrink tunnel that comprises an energy source, such as a heat source, which causes the shrink sleeve film to activate its shrinking properties and shrink onto the exterior of the basic body. The energy source may comprise an electric heat or steam heat, for example. Any printed design on the shrink sleeve film label may be located such that it ends up in a predefined area on the basic body after the shrinking of the shrink sleeve film. Alternatively, the prepared container may be decorated, e.g. by printing, after the shrinking process .

The thermal adhesive may be applied more or less on the entire outer surface of the basic body before the shrink sleeve film is applied, or the shrink sleeve film itself may be provided with adhesive already applied to the inner surface of the film (e.g., the surface that will be applied to the outer surface of the basic body) . The thermal adhesive is subsequently activated as the basic body passes through the shrink tunnel comprising heat source.

For further illustration of the invention, two preferred embodiments are schematically shown in the drawings:

Figure 1 shows a container 1 comprising a dimensionally stable, hollow basic body 5. Said hollow basic body 5 comprises an inner surface 2 and an outer surface 3 formed by a bottom portion 10 and a body wall 15 and also a neck portion 20. All components, i.e., bottom portion 10, body wall 15 and neck portion 20 are integrally made of the same material, which allows an easy and cheap preparation thereof. A liner 25 covers essentially the complete outer surface of the body wall 15. The liner 25 is a shrink sleeve film consisting of a composite of a PLA, or alternatively of another shrinkable material, and a barrier material comprising at least one liquid-crystal polymer (LCP) .

The basic body 5 is made from PET. Alternatively the basic body 5 can be prepared from a material selected from the group consisting of paper; cellophane; a starch-based material; and a polymer or copolymer, the polymer or copolymer being selected from the group consisting of polypropylene (PP); polyethylene (PE); polyethylene terephthalate (PET); polyethylene naphthalate (PEN); polycarbonates (PC); and mixtures thereof.

Figure 2 shows a container 1' according to another embodiment of the present invention. In contrast to the embodiment of figure 1, not only the outer surface 3 of the body wall 15, but also of the bottom portion 10 of the basic body 5 is covered by the liner 25.

Claims

A container (1, 1') comprising

a dimensionally stable, hollow basic body (5) with an inner (2) and an outer surface (3) formed by a bottom portion (10) and a body wall (15), said bottom portion (10) and said body wall (15) being integrally made of the same material, and

a liner (25) covering at least essentially the complete outer surface (3) of the body wall (15) of said hollow basic body (5),

wherein the basic body (5) is made from a material selected from the group consisting of paper; cellophane; a starch-based material; and a polymer or copolymer, the polymer or copolymer being selected from the group consisting of polypropylene (PP) polyethylene (PE); polyethylene terephthalate (PET) polyethylene naphthalate (PEN); polycarbonates (PC) and mixtures thereof,

and wherein the liner (25) is a shrink sleeve film consisting of a composite of a shrinkable material and a barrier material comprising at least one liquid- crystal polymer (LCP) .

A container (1' ) according to claim 1, wherein between the outer surface (3) of the body wall (15) of the hollow basic body (5) and the liner (25) an adhesion promoter is present.

3. A container (1) according to any of the preceding claims, wherein the basic body material comprises the adhesion promoter.

A container (1') according to any of the preceding claims, wherein the surface of the base body is pretreated by corona treatment or plasma treatment.

A container (1') according to any of the preceding claims, wherein also at least essentially the complete outer surface (3) of the bottom portion (10) is covered with the liner (25) .

A container (1, 1') according to claim 1 to 5, wherein the liner (25) is impermeable to gas, vapour, moisture and liquids.

A container (1, 1') according to one of claims 1 to 6, wherein the shrinkable material is a polymeric heat- shrink material, preferably selected from the group consisting of ethylene propylene diene monomer (EPDM) , polylactic acid (PLA) , high heat polylactic acid (PLA) , polyethylene terephthalate (PET), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), polyhydroxyalkanoates (PHA), , a starch-based polymer, a furan-based polymer, polyethylene (PE), polyethylene naphthalate (PEN), and mixtures thereof.

A container (1, 1') according to one of claims 1 to 7, wherein the liner (25) is made from a blend of the barrier material and the shrinkable material; or from a laminate of the barrier material with the shrinkable material film; or from a coextruded film of the barrier material and the shrinkable material; or from the shrinkable material being coated with the barrier material .

A container (1, 1') according to one of claims 1 to 8, wherein the barrier material further comprises at least one polymer selected from the group consisting of cross-linked thermoplastic epoxy-based polymers, Nylon-MXD6, cross-linked polyvinyl alcohol (PVOH) , cross-linked ethylene vinyl alcohol (EVOH) , polyglycolide (PGA), and mixtures thereof.

A container (1, 1') according to one of claims 1 to 9, wherein the liner (25) has a thickness of less than 50 μτ , preferably of less than 25 μιη, more preferably of less than 10 μπι, and most preferably of less than 5 μπι.

11. A container (1, 1') according to one of claims 1 to

10, wherein the liner (25) is a multi-layer film.

12. A container (1, 1') according to one of claims 1 to

11, wherein the container (1, 1') further comprises an adhesive layer positioned between and adhering to the basic body (5) and the liner (25) .

13. A container (1, 1') according to claim 12, wherein the adhesive is a heat or UV activated adhesive.

A container (1, 1' ) according to one of claims 1 to 13, wherein the container (1, 1' ) further comprises a neck portion (20) having an exterior-threaded sidewall and a removable cap having an interior-threaded sidewall, the cap being dimensioned for being screwed onto the neck portion (20) of the particular container .

Method for producing a container (1, 1') according to one of claims 1 to 14, said method comprising the steps of preparing a basic body (5) in form of the container (1), preparing a liner (25) in form of a shrink sleeve comprising a barrier material comprising at least one LCP, and adhering the liner (25) to at least the outer surface (3) of the body wall (15) of the basic body (5) by shrinking the liner (25) to conform to the basic body (5) .

Method according to claim 15, wherein the container (1, 1') is prepared by inserting the liner (25) within an open mold prior to closing of the mold around an extruded hot material forming the basic body (5) or a heated injection molded basic body (5) .

Method according to claim 15 or 16, wherein an adhesive material is applied at least to part of the outer surface (3) of the body wall (15) of the basic body (5) and/or to the liner (25) before shrinking the liner (25) .

Use of a barrier material comprising at least one liquid-crystal polymer for preparing a shrink sleeve (25) for a container (1, 1' ) for a food product, beverage or pharmaceutical product.