Recyclable surface-coated plastic film
Patent Information
- Application Number
- EP2023834136
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-12-19
- Filing Date
- 2023-12-19
- Publication Date
- 2025-10-29
AI Technical Summary
Surface-coated plastic films are not economically or ecologically recyclable due to the difficulty in separating the surface coatings from the substrate, which hinders the circular economy principles by often resulting in downcycling or energy recovery rather than the accurate separation and recycling of raw materials.
Incorporating a water-soluble polymer layer, such as butenediol-vinyl alcohol copolymer (BVOH) or polyvinyl alcohol (PVOH), as a separating layer between the film substrate and the surface coating, allowing for the separation of materials through water solubility, enabling the film to be split into its components during recycling.
The use of water-soluble polymers facilitates the separation of surface coatings from the substrate during recycling, enhancing the recyclability of plastic films and aligning with circular economy goals by allowing for the recovery of raw materials without environmental harm.
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Figure 1.1
Abstract
Description
Recyclable surface-coated plastic film
[0001] The priority of German patent application No. 10 2022 213 879.1 of December 19, 2022 is claimed.
[0002] The invention relates to a plastic film surface-coated on at least one side, comprising a carrier film with a first outer layer and a second outer layer; and a first surface coating which covers at least part of the first outer layer of the carrier film; wherein the carrier film comprises at least one layer which contains or is based on non-water-soluble polymer; and the plastic film contains water-soluble polymer, wherein (i) the carrier film comprises at least one layer which contains or is based on water-soluble polymer, and / or (ii) the first surface coating contains or is based on water-soluble polymer.
[0003] Surface-coated plastic films are used in a wide variety of applications. Coatings include, for example, non-adhesive silicone coatings, adhesive pressure-sensitive adhesive coatings, printing inks, and varnishes.
[0004] Such surface-coated films cannot be recycled economically and ecologically in the spirit of a circular economy. This is because the surface coatings, such as silicones, pressure-sensitive adhesives, printing inks, or varnishes, cannot be sufficiently separated from the substrate, the main raw material.
[0005] Recycling the main raw material with a coating runs counter to the spirit of a circular economy and usually results in downcycling or energy recovery. In the spirit of a circular economy, it is therefore necessary that the main raw materials can be separated as cleanly as possible during recycling and recycled. For example, in a release film with a non-adhesive silicone coating, this means removing the silicone from the film.
[0006] Various processes for recycling plastic films are known from the state of the art. Recyclable plastic films have been developed from these.
[0007] DE 41 20 685 A1 discloses a laminate material containing at least one layer of thermoplastic material and possessing a latently inherent delamination potential. The thermoplastic layer carries a release layer of water-soluble or water-dispersible organic material on at least one side.
[0008] DE 10 2012 006 416 Al concerns a metal-free multilayer film with a basis weight of < 33 g / m 2 , a shrinkage of < 10% at 90°C (both in machine direction and cross to machine direction, determined as dimensional change according to DIN 53377) and a at least six-layer layer structure comprising a layer (a) composed of at least one thermoplastic olefin homo- or copolymer as one of the outer layers, an adhesion promoter layer (b), a layer (c) composed of at least one homo- and / or copolyamide, at least one internal gas barrier layer (d) adjacent to layer (c) which differs from layers (c) and (e) at least in the composition of the polymer component(s); a layer (e) composed of at least one homo- and / or copolyamide adjacent to the gas barrier layer (d), and a layer (i) composed of at least one homo- and / or copolyamide as one of the outer layers, a use of such a multilayer film for producing a buoyancy body, and a buoyancy body made from such a multilayer film.
[0009] DE 10 2014 017 015 A1 discloses a multilayer polymer film comprising at least one middle layer A, the polymeric components of which are soluble in aqueous solution, and at least one essentially water-impermeable cover layer B, C arranged above and below the at least one middle layer A, wherein the layers A, B and C independently of one another each contain at least one thermoplastic polymer and at least one of the cover layers B and C contains at least one polyhydroxyalkanoate, as well as a process for producing the multilayer polymer film and its use for producing molded parts, films or bags.
[0010] EP 0 569 196 A1 and US 5 419 967 disclose that by adding methacrylate / unsaturated acid and / or vinylamide copolymers, poly(vinyl alcohol) can be melt processed and coextruded with structural polymers such as poly(ethylene terephthalate) to form multilayer films and articles with good adhesion between the components and good barrier properties.
[0011] EP 0 934 160 B1 relates to a laminated packaging material comprising a layer of paper or cardboard and outer liquid-tight plastic coatings on both sides of the paper or cardboard web. To facilitate material recycling after use of the laminated packaging material, the packaging material is provided with layers of water-soluble polymer between the paper or cardboard layer and each respective outer plastic coating, the layers serving as an adhesive or binder.
[0012] EP 3 885 095 A1 concerns the use of mixtures of water and essential oil for separating multilayer composites for the sorted recycling of polymer or metal foils.
[0013] US 2018 0369859 A1 relates to films that include a water-soluble layer and a vapor-deposited organic coating. The films exhibit improved barrier properties.
[0014] US 2019 0366591 A1 relates to a process for recycling a first polymer from a multi-component polymer product.
[0015] US 2020 0055650 A1 relates to films comprising a water-soluble polymer material and a vapor-deposited inorganic coating.
[0016] US 2020 0199313 A1 relates to water-soluble films made of copolymers of butenediol and vinyl alcohol, the films having improved barrier properties (such as low transmission rates for oxygen and water vapor) and good solubility.
[0017] WO 2000 / 077082 A1 relates to a process for separating plastic mixtures, with a polyolefinic plastic fraction or a plastic mixture as starting material, in which the starting material is brought into contact with a solvent and the temperature of the solvent-plastic mixture is adjusted so that a solution with at least one dissolved polymer type is formed, wherein the dissolved polymer type is precipitated from the solution under shear in order to separate the polymer type from other components of the solution.
[0018] WO 2005 / 118691 A2 relates to a process for the recycling of polyamides from waste, wherein the waste is mixed with ester solvent and the mixture is heated to a temperature above the melting temperature of the polyolefins contained therein to form a composition containing dissolved polyamide polymer and a separate immiscible liquid polyolefin phase.
[0019] WO 2020 / 136674 A1 relates to a recyclable laminate comprising a first layer and a second layer, each layer being a polyolefin layer having a thickness in the range of 12-100 μm; and an intermediate layer having a thickness in the range of 10-35 μm sandwiched between the first polyolefin layer and the second polyolefin layer, the intermediate layer being a metallized polyolefin film having alcohol-based polymer barrier resins therein.
[0020] WO 2021 / 255544 A1 relates to release liners that can be included in various adhesive products. A first release layer is a layer of a composition comprising a) a polymer material having at least one hydrogen atom covalently bonded to an oxygen atom, a nitrogen atom, or a sulfur atom; and b) a silicone polyether comprising at least one of polyoxoethylene units or polyoxopropylene units. A second release layer comprises a substrate and a coating of the above composition disposed on a major surface of the substrate. The release liner composition can advantageously be dissolved and optionally recycled.
[0021] WO 20222 / 46173A1 discloses a recyclable laminate film structure comprising a release coating. The release coating facilitates the separation of a selected polymer film during recycling processing by selecting the polymer of the coating composition to have specific Hansen solubility parameters such that the laminate structure delaminates at the coating layer, leaving clean pieces of the selected polymer film. In certain embodiments, the release coating is a barrier coating, for example, an oxygen barrier coating.
[0022] However, the suitability of the known surface-coated films for use in a circular economy is hardly possible or at least in need of improvement.
[0023] One object of the invention was therefore to adapt and improve the design of surface-coated films with a view to a circular economy.
[0024] This problem is solved by the subject matter of the patent claims.
[0025] It has surprisingly been discovered that water-soluble polymers, in particular butenediol-vinyl alcohol copolymer (BVOH) or polyvinyl alcohol (PVOH), can act as a separating layer or predetermined breaking point between the film substrate and the surface coating. The use of biodegradable and environmentally safe water-soluble polymers is paramount here. The separating layer or predetermined breaking point is preferably located on at least one outer surface of the substrate, but can also be present within the substrate.
[0026] Furthermore, it was found that the application properties of the final product are not significantly impaired by the introduction of at least one release layer or predetermined breaking point based on a water-soluble polymer, or can be otherwise compensated for using methods familiar to the person skilled in the art. In the spirit of a circular economy, the plastic film according to the invention exhibits good recyclability.
[0027] A first aspect of the invention relates to a plastic film surface-coated on at least one side, comprising a carrier film with a first outer layer and a second outer layer; and a first surface coating which at least partially covers the first outer layer of the carrier film; wherein the carrier film comprises at least one layer which contains or is based on a non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide; and the plastic film contains a water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), more preferably butenediol-vinyl alcohol copolymer (BVOH); wherein (i) the carrier film comprises at least one layer which contains or is based on a water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), and / or (ii) the first surface coating contains or is based on a water-soluble polymer.
[0028] In preferred embodiments, the carrier film comprises a layer (a) based on a water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), and forming the first outer layer of the carrier film; and a layer (c) based on a non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide. Layer (a) is arranged between the first surface coating and layer (c). When used as intended, e.g. in the case of a non-adhesive first surface coating as a release film with release properties, the release properties of the release film are not significantly impaired by the presence of layer (a).After intended use, when the release film with release properties is no longer required and can be disposed of properly, layer (a) enables the material of the first surface coating to be separated from the material of layer (c) due to its water solubility and the subsequent. Recycling, in particular of the material of layer (c), which may be present in a single-material form. When treated in a water bath, optionally at elevated temperature and after a certain exposure time, the plastic film according to the invention can be split along layer (a) into the two materials adjacent to layer (a), i.e., into the material of the first surface coating and the material of layer (c), optionally together with other layers with which layer (c) may be combined.
[0029] In other preferred embodiments, the carrier film comprises at least one layer which contains a non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide, in a mixture with or is based on a water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH). In this case too, when used as intended, e.g. as a release film, the release properties of the release film are not significantly impaired by the presence of the water-soluble polymer. After intended use, when the release film with release properties is no longer required and can be disposed of properly, the water-soluble polymer in the layer enables the formation of a predetermined breaking point due to its water solubility. The plastic film according to the invention is then, when treated in a water bath, if necessary,at elevated temperature and after a certain exposure time, cleavable along the layer into the two materials adjacent to the layer.
[0030] Unless expressly stated otherwise, all percentages are by weight. Unless expressly stated otherwise, all percentages refer to the total weight of the plastic film according to the invention.
[0031] For the purposes of this description, a layer is "based" on a particular material if that material is the main component of that layer. The weight fraction of the material need not necessarily exceed 50% by weight of the total weight of the respective layer, but this is preferably the case. Typically, a layer is "based" on a particular material if that material makes up at least 70% by weight, more preferably at least 80% by weight, and even more preferably at least 90% by weight of that layer, in each case based on the total weight of the respective layer.
[0032] For the purposes of this description, "water-soluble" means that the material detaches when the composite (the laminate) is placed in a water bath for a sufficient period of time, e.g., 30 minutes, preferably with stirring, and optionally at an elevated temperature, e.g., 60°C. The water bath may contain conventional additives, such as surfactants. Similarly, for the purposes of this description, "insoluble in water" means that the material does not detach under the conditions mentioned above.
[0033] Preferably, a measurement method is used to determine whether a polymer is water-soluble or water-insoluble within the meaning of the invention. The water solubility of polymers is preferably determined according to OECD Guideline 105 in the version of July 27, 1995. Alternatively, reference may be made to OECD Directive 120 as amended on January 21, 2000 can be used. The water solubility of polymers is determined in accordance with Commission Regulation (EC) No. 440 / 2008 of May 30, 2008 laying down test methods pursuant to Regulation (EC) No. 1907 / 2006 of the European Parliament and of the Council concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), as amended on March 4, 2016, using Method A.6 "Water Solubility", which corresponds to OECD Test Guideline (TG) 105 (1995).
[0034] Preferably, "water-soluble" means a solubility in pure water at 20.0 ± 0.5°C of at least 2.0 g / L; correspondingly, "water-insoluble" preferably means a solubility of less than 2.0 g / L. This solubility limit was also chosen by the European Chemicals Agency (ECHA) (see Opinion on an Annex XV dossier proposing restrictions on intentionally-added microplastics of June 11, 2020).
[0035] Under the conditions mentioned, the water-soluble polymers according to the invention preferably have a water solubility which is significantly above the limit of 2.0 g / L, preferably at least 5.0 g / L; more preferably at least 10 g / L, even more preferably at least 15 g / L, most preferably at least 20 g / L, and in particular at least 25 g / L.
[0036] Water-soluble polymers according to the invention are preferably virtually unlimitedly miscible with water, especially at elevated temperatures, but then form gels above a certain concentration, the viscosity of which may increase significantly.
[0037] In preferred embodiments, the water-soluble polymers of the invention exhibit a solubility such that, at a concentration of 10 wt.% in pure water, the polymer is virtually completely dissolved after at most 40 minutes (i.e., upon reaching 60°C), preferably after at most 30 minutes (i.e., upon reaching 50°C), with stirring and continuous heating from 20°C to 85°C at a heating rate of 1°C / min. Products under the name Nichigo G-Polymer®, for example, meet this requirement.
[0038] In preferred embodiments, the water-soluble polymers according to the invention exhibit a solubility such that, at a concentration of 5.0 wt.% in pure water with stirring at 20°C, the polymer is virtually completely dissolved after at most 2 hours. This requirement is met, for example, by the product known as Nichigo G-Polymer® AZF8035W.
[0039] In preferred embodiments, the water-soluble polymers of the invention exhibit a solubility such that, at a concentration of 5.0 wt.% in pure water with stirring at a temperature of 70°C, the polymer is virtually completely dissolved after 1 hour at the latest. This requirement is met, for example, by the products under the names Nichigo G-Polymer® AZF8035W, OKS-1001, and OKS 8074P.
[0040] In preferred embodiments, the water-soluble polymers according to the invention have a solubility such that at a concentration of 5.0 wt.% in pure water with stirring At a temperature of 90°C, the polymer is practically completely dissolved after 1 hour at the latest. Products such as Nichigo G-Polymer® AZF8035W, OKS-1001, and OKS 8074P, for example, meet this requirement.
[0041] In preferred embodiments, a film with a layer thickness of 200 μm consisting of the pure water-soluble polymer dissolves completely in a sufficient amount of water within 6 minutes at 25°C and with stirring. These requirements are met, for example, by Mowiflex® types CI 7, C30, C600, C130T, and C500T.
[0042] Under the conditions mentioned, the non-water-soluble polymers according to the invention preferably have a water solubility which is significantly below the limit of 2.0 g / L (2000 mg / L), preferably at most 1000 mg / L; more preferably at most 500 mg / L, even more preferably at most 100 mg / L, most preferably at most 50 mg / L, and in particular at most 10 mg / L.
[0043] For the purposes of the invention, a polymer is preferably considered to be water-soluble if at least 50 g of this polymer can be homogenized in one liter of pure water at 25°C.
[0044] For the purposes of the invention and regardless of numerically quantified solubility (e.g., in g / L or mg / L), polyolefins, anhydride-modified polyolefins, acid-modified polyolefins, polyesters, and polyamides are preferably considered non-water-soluble polymers, and butenediol-vinyl alcohol copolymers (BVOH) and polyvinyl alcohols (PVOH) are considered water-soluble polymers. Suitable water-soluble polymers for the purposes of the invention are commercially available, for example, under the names Nichigo G-Polymer® and Mowiflex®.
[0045] If the water-soluble polymer according to the invention is a butenediol-vinyl alcohol copolymer (BVOH) or a polyvinyl alcohol (PVOH), vinyl acetate is typically used as a (co)monomer in the polymerization, and its ester groups are subsequently at least partially saponified. According to the invention, the degree of saponification is preferably, independently of one another, at least 80 mol%, more preferably at least 85 mol%, even more preferably at least 90 mol%, most preferably at least 95 mol%, and in particular approximately 100 mol%. It may be preferred if the degree of saponification is not complete, for example, at most 99 mol%, or at most 98 mol%, or at most 97 mol%.
[0046] Butenediol-vinyl alcohol copolymers (BVOH) preferred according to the invention have a melt flow index (MFI) at 210°C and 2160 g in the range of 0.5 to 35 g / 10 min, more preferably in the range of 1.0 to 30 g / 10 min, even more preferably in the range of 1.5 to 20 g / 10 min, most preferably in the range of 2.0 to 10 g / 10 min, and in particular in the range of 2.5 to 5.0 g / 10 min.
[0047] Polyvinyl alcohols (PVOH) preferred according to the invention have a melt flow index at 190°C and 2160 g in the range of 0.5 to 50 g / 10 min, more preferably in the range of 1.0 to 45 g / 10 min, even more preferably in the range of 1.5 to 40 g / 10 min, most preferably in the range of 2.0 to 35 g / 10 min, and in particular in the range of 2.5 to 30 g / 10 min.
[0048] According to the invention, it is possible to use mixtures of several water-soluble polymers, for example several polyvinyl alcohols (PVOH) with different degrees of saponification, several butenediol-vinyl alcohol copolymers (BVOH) with different degrees of saponification, or mixtures of polyvinyl alcohols (PVOH) with butenediol-vinyl alcohol copolymers (BVOH).
[0049] It is possible for the plastic film according to the invention to comprise further layers in addition to the required layers and the optional layers. However, the plastic film according to the invention preferably consists of the required layers and, if appropriate, one or more of the optional layers.
[0050] Preferably, the carrier film comprises at least one layer which contains or is based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), wherein the plastic film is cleavable along this layer upon treatment in a water bath, optionally at elevated temperature and after a sufficient exposure time.
[0051] In preferred embodiments of the plastic film according to the invention, the first surface coating is adhesive.
[0052] For the purpose of description, "dehesive" means a release force according to FINAT test method FTM10 (Tesa® test tape 7475, peel speed 300 mm / min, storage conditions 20h / 70°C) of not more than 50 cN / cm, more preferably not more than 40 cN / cm, even more preferably not more than 30 cN / cm.
[0053] Preferably, the first surface coating is based on polysiloxane.
[0054] In preferred embodiments of the plastic film according to the invention, the first surface coating is based on at least one cured polysiloxane, which is preferably selected from the group consisting of addition-crosslinked, preferably metal-catalyzed addition-crosslinked, condensation-crosslinked, radically crosslinked, and / or cationically crosslinked polysiloxanes.
[0055] In preferred embodiments of the plastic film according to the invention, the first surface coating is based on at least one cured polysiloxane, which is preferably selected from the group consisting of polydialkylsiloxanes, preferably polydimethylsiloxanes, and polyalkylarylsiloxanes, preferably polymethylphenylsiloxanes.
[0056] In other preferred embodiments of the plastic film according to the invention, the first surface coating is adhesive.
[0057] Preferably, the first surface coating is based on a pressure-sensitive adhesive.
[0058] In preferred embodiments of the plastic film according to the invention, the pressure-sensitive adhesive is selected from the group consisting of acrylate-based pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, polyisobutylene-based pressure-sensitive adhesives, and hot melts.
[0059] In further preferred embodiments of the plastic film according to the invention, the first surface coating is based on printing ink or varnish.
[0060] In preferred embodiments of the plastic film according to the invention, in particular when the first surface coating is adhesive, the first surface coating has a surface weight of at most 5.0 g / m 2 , preferably not more than 4.0 g / m 2 , more preferably not more than 3.0 g / m 2 , most preferably not more than 2.0 g / m 2 and in particular not more than 1.0 g / m 2The basis weight is preferably determined according to FINAT test method FTM7.
[0061] In other preferred embodiments of the plastic film according to the invention, in particular when the first surface coating is adhesive, the first surface coating has a basis weight of at most 100 g / m 2 , preferably not more than 80 g / m 2 , more preferably not more than 60 g / m 2 , preferably not more than 40 g / m 2 and in particular not more than 20 g / m 2 The basis weight is also preferably determined according to FINAT.
[0062] The first surface coating can cover the first outer side of the carrier film according to the invention partially or completely, preferably completely. To ensure sufficient resistance to moisture or wetness for the application, the surface coating should be applied as completely as possible. In the case of partially coated surfaces, the use of a varnish is therefore recommended, which can, for example, be printed over the entire surface to cover the areas covered by the first surface coating as well as the areas not covered by the first surface coating.
[0063] In preferred embodiments of the plastic film according to the invention, the second surface coating is adhesive.
[0064] Preferably, the second surface coating is based on polysiloxane.
[0065] In preferred embodiments of the plastic film according to the invention, the second surface coating is based on at least one cured polysiloxane, which is preferably selected from the group consisting of addition-crosslinked, preferably metal-catalyzed addition-crosslinked, condensation-crosslinked, radically crosslinked, and / or cationically crosslinked polysiloxanes.
[0066] In preferred embodiments of the plastic film according to the invention, the second surface coating is based on at least one cured polysiloxane, which is preferably selected from the group consisting of polydialkylsiloxanes, preferably polydimethylsiloxanes, and polyalkylarylsiloxanes, preferably polymethylphenylsiloxanes.
[0067] In other preferred embodiments of the plastic film according to the invention, the second surface coating is adhesive.
[0068] Preferably, the second surface coating is based on a pressure-sensitive adhesive.
[0069] Preferably, the pressure-sensitive adhesive is selected from the group consisting of acrylate-based pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, polyisobutylene-based pressure-sensitive adhesives, and hot melts.
[0070] In further preferred embodiments of the plastic film according to the invention, the second surface coating is based on printing ink or varnish.
[0071] In preferred embodiments of the plastic film according to the invention, in particular when the second surface coating is adhesive, the second surface coating has a surface weight of at most 5.0 g / m 2 , preferably not more than 4.0 g / m 2 , more preferably not more than 3.0 g / m 2 , most preferably not more than 2.0 g / m 2 and in particular not more than 1.0 g / m 2The basis weight is preferably determined according to FINAT test method FTM7.
[0072] In other preferred embodiments of the plastic film according to the invention, in particular when the second surface coating is adhesive, the second surface coating has a basis weight of at most 100 g / m 2 , preferably not more than 80 g / m 2 , more preferably not more than 60 g / m 2 , preferably not more than 40 g / m 2 and in particular not more than 20 g / m 2 The basis weight is also preferably determined according to FINAT.
[0073] The second surface coating can cover the second outer side of the carrier film according to the invention partially or completely, preferably completely. To ensure sufficient resistance to moisture or wetness for the application, the surface coating should be applied as completely as possible. In the case of partially coated surfaces, the use of a varnish is therefore recommended, which can, for example, be printed over the entire surface to cover the areas covered by the second surface coating as well as the areas not covered by the second surface coating.
[0074] In preferred embodiments, the plastic film according to the invention is a plastic film which is surface-coated on at least one side and which - a carrier film with a first outer layer and a second outer layer; - a first surface coating which at least partially covers the first outer layer of the carrier film; and optionally a second surface coating which optionally at least partially covers the second outer layer of the carrier film; comprises or consists of; wherein the carrier film (a) a layer (a) which is based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), and forms the first outer layer of the carrier film; (b) optionally an adhesion promoter layer (b); (c) a layer (c) based on non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide; (d) optionally an adhesion promoter layer (d); (e) optionally a layer (e) based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH); (f) optionally a layer (f) based on a non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide; and (g) optionally comprising or consisting of a layer (g) based on a water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH).
[0075] The first surface coating and layers (a) and (c) of the plastic film according to the invention are necessarily present. The second surface coating and layers (b), (d), (e), (f), and (g) are each independently optional. Preferably, those of the existing layers are arranged in alphabetical order.
[0076] According to these embodiments of the invention, layer (a) and optionally also layer (e) are based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH). Layer (a) and the optionally additional layer (e) do not significantly impair the functionality of the plastic film according to the invention when used for its intended purpose, e.g., as a release film with release properties. However, when the plastic film according to the invention is subjected to processes for the recovery of used raw materials (recycling), layer (a) and any additional layer (e) contribute significantly to the ability of individual components of the plastic film to be separated from one another.
[0077] In preferred embodiments of the plastic film according to the invention, layer (a) is based on extrudable, water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH).
[0078] Butenediol-vinyl alcohol copolymer (BVOH) is particularly preferred according to the invention because it can be extruded particularly advantageously and can therefore be processed, for example, by blown film coextrusion, while simultaneously exhibiting particularly good water solubility. In this respect, butenediol-vinyl alcohol copolymer (BVOH) is particularly advantageous compared to polyvinyl alcohol (PVOH) and polyvinyl acetate (PVA).
[0079] Preferably, layer (a) is based on one or more water-soluble polymers independently selected from (i) fully synthetic water-soluble polymers; and (ii) semi-synthetic or natural water-soluble polymers.
[0080] Preferably, layer (a) is based on one or more water-soluble polymers selected from polymers or copolymers of vinyl acetate, vinylpyrrolidone, ethylene oxide, acrylamide, and lactic acid; preferably polymers or copolymers of vinyl acetate.
[0081] In preferred embodiments of the plastic film according to the invention, layer (a) is based on one or more water-soluble polymers independently selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polyvinyl alcohol (PVOH), polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyacrylamide (PAM), and polylactic acid (PLA); preferably butenediol-vinyl alcohol copolymer (BVOH).
[0082] Preferably, layer (a) is based on one or more water-soluble polymers having an ethylene group content of at most 10 mol%, more preferably at most 5.0 mol%, even more preferably at most 2.5 mol%, and in particular practically no ethylene groups at all.
[0083] Preferably, layer (a) is based on one or more water-soluble polymers having a vinyl ester group content of at most 20 mol%, more preferably at most 15 mol%, even more preferably at most 10 mol%, most preferably at most 5.0 mol%, and in particular at most 2.5 mol%.
[0084] Preferably, layer (a) is based on one or more water-soluble polymers having a content of vinyl alcohol groups in the range of 40 to 85 mol%, preferably 50 to 75 mol%.
[0085] Preferably, layer (a) is based on one or more water-soluble polymers having a butylene group content in the range of 15 to 60 mol%, preferably 25 to 50 mol%.
[0086] In preferred embodiments, layer (a) contains, based on the total weight of layer (a), at least 50 wt.% water-soluble polymer, more preferably at least 60 wt.%, even more preferably at least 70 wt.%, most preferably at least 80 wt.% and in particular at least 90 wt.%.
[0087] Preferably, layer (a) contains, based on the total weight of layer (a), at most 10 wt.% of non-water-soluble polymer, more preferably 5 wt.%, even more preferably at most 2.5 wt.%, most preferably at most 1.0 wt.%, and in particular practically no non-water-soluble polymer.
[0088] Preferably, layer (a) has a layer thickness in the range of 0.5 to 100 pm, preferably 0.5 to 25 pm.
[0089] In preferred embodiments of the plastic film according to the invention, layer (a) has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
[0090] In preferred embodiments of the plastic film according to the invention, layer (a) has a layer thickness of at most 22 pm, more preferably at most 19 pm, even more preferably at most 16 pm, most preferably at most 13 pm and in particular at most 10 pm.
[0091] In preferred embodiments of the plastic film according to the invention, layer (a) has a layer thickness of at most 9.0 pm, more preferably at most 8.0 pm, even more preferably at most 7.0 pm, most preferably at most 6.0 pm and in particular at most 5.0 pm.
[0092] In preferred embodiments of the plastic film according to the invention, layer (a) has a layer thickness of at most 4.0 pm, more preferably at most 3.0 pm, even more preferably at most 2.5 pm, most preferably at most 2.0 pm and in particular at most 1.75 pm.
[0093] In preferred embodiments of the plastic film according to the invention, the adhesion promoter layer (b) is based on anhydride-modified or acid-modified polyolefin.
[0094] In addition to the anhydride-modified or acid-modified polyolefin, the adhesion promoter layer (b) may optionally contain further polymers, preferably those polymers which are contained in one of the layers adjacent to the adhesion promoter layer (b), i.e. the same water-soluble polymer which is contained in layer (a) and / or the same non-water-soluble polymer which is contained in layer (c).
[0095] In preferred embodiments, the adhesion promoter layer (b) contains, based on the total weight of the adhesion promoter layer (b), at least 30 wt.% of non-water-soluble polymer, more preferably at least 40 wt.%, even more preferably at least 50 wt.%, most preferably at least 60 wt.% and in particular at least 70 wt.%.
[0096] The adhesion promoter layer (b) preferably has a layer thickness in the range from 0.5 to 25 pm, preferably 0.5 to 10 pm.
[0097] In preferred embodiments of the plastic film according to the invention, the adhesion promoter layer (b) has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and especially at least 5.0 pm.
[0098] In preferred embodiments of the plastic film according to the invention, the adhesion promoter layer (b) has a layer thickness of at most 9.0 pm, more preferably at most 8.0 pm, even more preferably at most 7.0 pm, most preferably at most 6.0 pm and in particular at most 5.0 pm.
[0099] In preferred embodiments of the plastic film according to the invention, layer (c) is based on one or more non-water-soluble polymers independently selected from the group consisting of polyolefins, polyesters and polyamides.
[0100] Preferably, layer (c) is based on one or more non-water-soluble polymers independently selected from the group consisting of - thermoplastic olefin homopolymers; and / or - thermoplastic olefin copolymers of α,β-unsaturated olefins having 2 to 10 carbon atoms.
[0101] Preferably, layer (c) is based on one or more non-water-soluble polymers independently selected from the group consisting of polyethylene, polypropylene, polybutylene, polyisobutylene (PI), copolymers and / or mixtures of at least two of the polymers mentioned.
[0102] In preferred embodiments, layer (c) contains, based on the total weight of layer (c), at least 50 wt% of non-water-soluble polymer, more preferably at least 60 wt%, even more preferably at least 70 wt%, most preferably at least 80 wt% and in particular at least 90 wt%.
[0103] Preferably, layer (c) contains, based on the total weight of layer (a), at most 10 wt.% water-soluble polymer, more preferably 5 wt.%, even more preferably at most 2.5 wt.%, most preferably at most 1.0 wt.%, and in particular practically no water-soluble polymer at all.
[0104] In preferred embodiments, layer (c) comprises several layers (ci), (C2), etc.
[0105] In particularly preferred embodiments, layer (c) has at least three layers and comprises layer (C1), layer (C2), and layer (C3), with layer (C2) being arranged between layers (C1) and (C3). Layers (C1) and (C3) are preferably based on the same non-water-soluble polymer, which preferably differs from the non-water-soluble polymer on which layer (C2) is based.
[0106] In preferred embodiments, the layer (c) or the layer (C2) is based on polyolefin, preferably olefin homo- or copolymer, which is preferably selected from the group consisting of made of polyethylene, polypropylene, polybutylene, polyisobutylene, polyhexene, polyoctene, copolymers and / or mixtures of at least two of the polymers mentioned.
[0107] Preferably, the olefin homopolymer or copolymer of layer (c) or layer (C2) is an ethylene homopolymer or an ethylene copolymer.
[0108] Preferably, the ethylene homo- or copolymer of layer (c) or ply (C2) is selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE).
[0109] Ethylene homopolymers or copolymers are understood to mean ethylene homopolymers based exclusively on ethylene, and ethylene copolymers based, in addition to ethylene, on at least one other α,β-unsaturated olefin having 3 to 10 carbon atoms. Preferred ethylene homopolymers or copolymers are polyethylene with highly branched polymer chains and a low density in the range of 0.915 to 0.940 g / cm³. 3 (LDPE); polyethylene with an average density in the range of 0.926 to 0.940 g / cm 3(MDPE); polyethylene with weakly branched polymer chains and a high density in the range of 0.945 to 0.97 g / cm 3 (HDPE); and linear low-density polyethylene with short branched polymer chains, which may contain, in addition to ethylene as a comonomer, one or more higher α,β-unsaturated olefins such as butylene, hexene, or octene, with a density in the range of 0.915 to 0.94 g / cm 3 (LLDPE).
[0110] Preferably, the polyolefin on which the layer (c) or the ply (C2) is based comprises a mixture of an ethylene homo- or copolymer and a propylene homo- or copolymer.
[0111] In preferred embodiments, the polyolefin on which the layer (c) or the layer (C2) is based comprises a mixture of - 51 to 85 wt.% of an ethylene homo- or copolymer having a density in the range of 0.91 to 0.97 g / cm 3 ; and - 15 to 49% by weight of a propylene homo- or copolymer; in each case based on the total weight of the mixture.
[0112] Propylene homopolymers or copolymers are understood to mean propylene homopolymers based exclusively on propylene and propylene copolymers based, in addition to propylene, on at least one other α,β-unsaturated olefin having 2 to 10 carbon atoms. Preferred propylene homopolymers are isotactic propylene homopolymers, preferably with a melting point in the range of 140 to 170°C. Preferred propylene copolymers are copolymers of propylene and ethylene, with the proportion of ethylene preferably being at most 20 wt.%, based on the total weight of the propylene copolymer.
[0113] In preferred embodiments, the layer (c) or the ply (C2) consists of LDPE and a propylene homo- or copolymer.
[0114] In other preferred embodiments, the layer (c) or the ply (C2) consists of LLDPE and a propylene homo- or copolymer.
[0115] Preferably, the layer (c) or the layers (ci) and (C3) are each independently based on - polyolefin, wherein the polyolefin is selected from the group consisting of olefin homo- or copolymers of α,β-unsaturated olefins having 2 to 10 carbon atoms; or - an ethylene-vinyl acetate copolymer.
[0116] In preferred embodiments, layer (c) or layers (ci) and (C3) are each independently based on an ethylene-vinyl acetate copolymer.
[0117] In other preferred embodiments, the layer (c) or the layers (ci) and (C3) are each independently based on polyolefin, wherein the polyolefin is selected from the group consisting of olefin homo- or copolymers of α,β-unsaturated olefins having 2 to 10 carbon atoms.
[0118] In these preferred embodiments, the polyolefin of layer (c) or of layers (ci) and (C3) is preferably selected, independently of one another, from the group consisting of polyethylene, polypropylene, polybutylene, polyisobutylene, polyhexene, polyoctene, copolymers and / or mixtures of at least two of the polymers mentioned.
[0119] Preferably, the olefin homopolymer or copolymer of layer (c) or of layers (c1) and (C3) is each independently an ethylene homopolymer or an ethylene copolymer.
[0120] Preferably, the ethylene homo- or copolymer of layer (c) or of layers (ci) and (C3) is each independently selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), and mixtures thereof.
[0121] Preferably, layer (c) or layers (c1) and (C3) each independently consist of a mixture of two ethylene homopolymers or copolymers, preferably a mixture of LDPE with LLDPE, MDPE, or HDPE. The proportion of LDPE is preferably in the range of 10 to 85 wt.%, and the proportion of the second ethylene homopolymer or copolymer is preferably in the range of 15 to 90 wt.%.
[0122] Preferably, layer (c) has a layer thickness in the range of 0.5 to 100 pm, preferably 0.5 to 25 pm.
[0123] In preferred embodiments of the plastic film according to the invention, layer (c) has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
[0124] In preferred embodiments of the plastic film according to the invention, layer (c) has a layer thickness of at most 22 pm, more preferably at most 19 pm, even more preferably at most 16 pm, most preferably at most 13 pm and in particular at most 10 pm.
[0125] In preferred embodiments of the plastic film according to the invention, the adhesion promoter layer (d) is based on anhydride-modified or acid-modified polyolefin.
[0126] In addition to the anhydride-modified or acid-modified polyolefin, the adhesion promoter layer (d) may optionally contain further polymers, preferably those polymers which are contained in one of the layers adjacent to the adhesion promoter layer (d), i.e. the same water-soluble polymer which is contained in layer (e) and / or the same non-water-soluble polymer which is contained in layer (c).
[0127] In preferred embodiments, the adhesion promoter layer (d) contains, based on the total weight of the adhesion promoter layer (d), at least 30 wt.% non-water-soluble polymer, more preferably at least 40 wt.%, even more preferably at least 50 wt.%, most preferably at least 60 wt.% and in particular at least 70 wt.%.
[0128] The adhesion promoter layer (d) preferably has a layer thickness in the range from 0.5 to 25 pm, preferably 0.5 to 10 pm.
[0129] In preferred embodiments of the plastic film according to the invention, the adhesion promoter layer (d) has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
[0130] In preferred embodiments of the plastic film according to the invention, the adhesion promoter layer (d) has a layer thickness of at most 9.0 pm, more preferably at most 8.0 pm, even more preferably at most 7.0 pm, most preferably at most 6.0 pm and in particular at most 5.0 pm.
[0131] In preferred embodiments of the plastic film according to the invention, the adhesion promoter layer (d) has the same layer structure as the adhesion promoter layer (b).
[0132] In other preferred embodiments of the plastic film according to the invention, the adhesion promoter layer (d) has a different layer structure than the adhesion promoter layer (b).
[0133] In preferred embodiments of the plastic film according to the invention, layer (e) is based on extrudable, water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH).
[0134] Preferably, the layer (e) is based on one or more water-soluble polymers independently selected from (i) fully synthetic water-soluble polymers; or (ii) semi-synthetic or natural water-soluble polymers.
[0135] Preferably, layer (e) is based on one or more water-soluble polymers selected from polymers or copolymers of vinyl acetate, vinylpyrrolidone, ethylene oxide, acrylamide, and lactic acid; preferably polymers or copolymers of vinyl acetate.
[0136] Preferably, the layer (e) is based on one or more water-soluble polymers independently selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polyvinyl alcohol (PVOH), polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyacrylamide (PAM), and polylactic acid (PLA); preferably butenediol-vinyl alcohol copolymer (BVOH).
[0137] Preferably, the layer (e) is based on one or more water-soluble polymers having an ethylene group content of at most 10 mol%, more preferably at most 5.0 mol%, even more preferably at most 2.5 mol%, and in particular practically no ethylene groups at all.
[0138] Preferably, layer (e) is based on one or more water-soluble polymers having a vinyl ester group content of at most 20 mol%, more preferably at most 15 mol%, even more preferably at most 10 mol%, most preferably at most 5.0 mol%, and in particular at most 2.5 mol%.
[0139] Preferably, layer (e) is based on one or more water-soluble polymers having a content of vinyl alcohol groups in the range of 40 to 85 mol%, preferably 50 to 75 mol%.
[0140] Preferably, layer (e) is based on one or more water-soluble polymers having a butylene group content in the range of 15 to 60 mol%, preferably 25 to 50 mol%.
[0141] In preferred embodiments, layer (e) contains, based on the total weight of layer (e), at least 50 wt.% water-soluble polymer, more preferably at least 60 wt.%, even more preferably at least 70 wt.%, most preferably at least 80 wt.% and in particular at least 90 wt.%.
[0142] Preferably, layer (e) contains, based on the total weight of layer (e), at most 10 wt.% of non-water-soluble polymer, more preferably 5 wt.%, even more preferably at most 2.5 wt.%, most preferably at most 1.0 wt.%, and in particular practically no non-water-soluble polymer at all.
[0143] Preferably, the layer (e) has a layer thickness in the range of 0.5 to 100 pm, preferably 0.5 to 25 pm.
[0144] In preferred embodiments of the plastic film according to the invention, layer (e) has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
[0145] In preferred embodiments of the plastic film according to the invention, layer (e) has a layer thickness of at most 22 pm, more preferably at most 19 pm, even more preferably at most 16 pm, most preferably at most 13 pm and in particular at most 10 pm.
[0146] In preferred embodiments of the plastic film according to the invention, layer (e) has a layer thickness of at most 9.0 pm, more preferably at most 8.0 pm, even more preferably at most 7.0 pm, most preferably at most 6.0 pm and in particular at most 5.0 pm.
[0147] In preferred embodiments of the plastic film according to the invention, layer (e) has a layer thickness of at most 4.0 pm, more preferably at most 3.0 pm, even more preferably at most 2.5 pm, most preferably at most 2.0 pm and in particular at most 1.75 pm.
[0148] In preferred embodiments of the plastic film according to the invention, the layer (e) has the same layer structure as layer (a).
[0149] In other preferred embodiments of the plastic film according to the invention, layer (e) has a different layer structure than layer (a).
[0150] In preferred embodiments of the plastic film according to the invention, the layer (f) on one or more non-water-soluble polymers independently selected from the group consisting of polyolefins, polyesters and polyamides.
[0151] Preferably, the layer (f) is based on one or more non-water-soluble polymers independently selected from the group consisting of - thermoplastic olefin homopolymers; and / or - thermoplastic olefin copolymers of α,β-unsaturated olefins having 2 to 10 carbon atoms.
[0152] Preferably, layer (f) is based on one or more non-water-soluble polymers independently selected from the group consisting of polyethylene, polypropylene, polybutylene, polyisobutylene (PI), copolymers and / or mixtures of at least two of said polymers.
[0153] In preferred embodiments, layer (f) contains, based on the total weight of layer (f), at least 50 wt% of non-water-soluble polymer, more preferably at least 60 wt%, even more preferably at least 70 wt%, most preferably at least 80 wt% and in particular at least 90 wt%.
[0154] Preferably, layer (f) contains, based on the total weight of layer (f), at most 10 wt.% water-soluble polymer, more preferably 5 wt.%, even more preferably at most 2.5 wt.%, most preferably at most 1.0 wt.%, and in particular practically no water-soluble polymer at all.
[0155] Preferably, layer (f) has a layer thickness in the range from 0.5 to 100 pm, preferably 0.5 to 25 pm.
[0156] In preferred embodiments of the plastic film according to the invention, layer (f) has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
[0157] In preferred embodiments of the plastic film according to the invention, layer (f) has a layer thickness of at most 22 pm, more preferably at most 19 pm, even more preferably at most 16 pm, most preferably at most 13 pm and in particular at most 10 pm.
[0158] In preferred embodiments of the plastic film according to the invention, the layer (f) has the same layer structure as layer (c).
[0159] In other preferred embodiments of the plastic film according to the invention, layer (f) has a different layer structure than layer (c).
[0160] In preferred embodiments of the plastic film according to the invention, the layer (g) on extrudable, water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH).
[0161] Preferably, the layer (g) is based on one or more water-soluble polymers independently selected from (i) fully synthetic water-soluble polymers; or (ii) semi-synthetic or natural water-soluble polymers.
[0162] Preferably, layer (g) is based on one or more water-soluble polymers selected from polymers or copolymers of vinyl acetate, vinylpyrrolidone, ethylene oxide, acrylamide, and lactic acid; preferably polymers or copolymers of vinyl acetate.
[0163] Preferably, layer (g) is based on one or more water-soluble polymers independently selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polyvinyl alcohol (PVOH), polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyacrylamide (PAM), and polylactic acid (PLA); preferably butenediol-vinyl alcohol copolymer (BVOH).
[0164] Preferably, layer (g) is based on one or more water-soluble polymers having an ethylene group content of at most 10 mol%, more preferably at most 5.0 mol%, even more preferably at most 2.5 mol%, and in particular practically no ethylene groups at all.
[0165] Preferably, the layer (g) is based on one or more water-soluble polymers having a vinyl ester group content of at most 20 mol%, more preferably at most 15 mol%, nor more preferably at most 10 mol%, most preferably at most 5.0 mol%, and especially at most 2.5 mol%.
[0166] Preferably, layer (g) is based on one or more water-soluble polymers having a vinyl alcohol group content in the range of 40 to 85 mol%, preferably 50 to 75 mol%.
[0167] Preferably, layer (g) is based on one or more water-soluble polymers having a butylene group content in the range of 15 to 60 mol%, preferably 25 to 50 mol%.
[0168] In preferred embodiments, layer (g) contains, based on the total weight of layer (g), at least 50 wt.% water-soluble polymer, more preferably at least 60 wt.%, even more preferably at least 70 wt.%, most preferably at least 80 wt.% and in particular at least 90 wt.%.
[0169] Preferably, layer (g) contains, based on the total weight of layer (g), at most 10 wt.% of non-water-soluble polymer, more preferably 5 wt.%, even more preferably at most 2.5 wt.%, most preferably at most 1.0 wt.%, and in particular practically no non-water-soluble polymer.
[0170] Preferably, layer (g) has a layer thickness in the range of 0.5 to 100 pm, preferably 0.5 to 25 pm.
[0171] In preferred embodiments of the plastic film according to the invention, layer (g) has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
[0172] In preferred embodiments of the plastic film according to the invention, layer (g) has a layer thickness of at most 22 pm, more preferably at most 19 pm, even more preferably at most 16 pm, most preferably at most 13 pm and in particular at most 10 pm.
[0173] In preferred embodiments of the plastic film according to the invention, layer (g) has a layer thickness of at most 9.0 pm, more preferably at most 8.0 pm, even more preferably at most 7.0 pm, most preferably at most 6.0 pm and in particular at most 5.0 pm.
[0174] In preferred embodiments of the plastic film according to the invention, layer (g) has a layer thickness of at most 4.0 pm, more preferably at most 3.0 pm, even more preferably at most 2.5 pm, most preferably at most 2.0 pm and in particular at most 1.75 pm.
[0175] In preferred embodiments of the plastic film according to the invention, layer (g) has the same layer structure as layer (e).
[0176] In other preferred embodiments of the plastic film according to the invention, layer (g) has a different layer structure than layer (e).
[0177] In preferred embodiments of the plastic film according to the invention, the plastic film has a total layer thickness in the range of 10 to 250 pm.
[0178] The plastic film preferably has a total layer thickness of at least 20 pm, more preferably at least 25 pm, even more preferably at least 30 pm, most preferably at least 35 pm and in particular at least 40 pm.
[0179] The plastic film preferably has a total layer thickness of at most 90 pm, more preferably at most 80 pm, even more preferably at most 70 pm, most preferably at most 60 pm and in particular at most 50 pm.
[0180] The plastic film according to the invention is preferably extrudable, preferably coextrudable in one step, more preferably by blown film coextrusion.
[0181] In preferred embodiments of the plastic film according to the invention, the carrier film has a symmetrical layer structure.
[0182] Preferably, layer (b) is arranged between layer (a) and layer (c); preferably, it is in direct contact with layer (a) and / or layer (c).
[0183] Preferably, layer (c) is arranged between layer (b) and layer (d); preferably, it is in direct contact with layer (b) and / or with layer (d).
[0184] Preferably, layer (d) is arranged between layer (c) and layer (e); preferably, it is in direct contact with layer (c) and / or with layer (e).
[0185] Preferably, layer (e) is arranged between layer (d) and layer (f); preferably, it is in direct contact with layer (d) and / or with layer (f).
[0186] Preferably, layer (f) is arranged between layer (e) and layer (g); preferably, it is in direct contact with layer (e) and / or layer (g).
[0187] In preferred embodiments, the plastic film according to the invention has the following structure: - first surface coating; - layer (a) which is based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), and forms the first outer layer of the carrier film; - adhesion promoter layer (b); and - Layer (c) based on non-water-soluble polymer, preferably polypropylene.
[0188] In further preferred embodiments, the plastic film according to the invention has the following structure: first surface coating; - layer (a) which is based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), and forms the first outer layer of the carrier film; - adhesion promoter layer (b); - layer (c) based on non-water-soluble polymer, preferably polypropylene; - adhesion promoter layer (d); - layer(s) based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH); and - second surface coating.
[0189] In other preferred embodiments, the plastic film according to the invention has the following structure: - first surface coating; - layer (a) which is based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), and forms the first outer layer of the carrier film; - adhesion promoter layer (b); - layer (c) based on non-water-soluble polymer, preferably polypropylene; - adhesion promoter layer (d); - layer(s) based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH); - layer (f) based on non-water-soluble polymer, preferably polyamide; - optionally, layer (g) which is based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH); and - second surface coating.
[0190] In preferred embodiments of the plastic film according to the invention, the carrier film has a layer structure selected from (i) (a)-(c); (ii) (a)-(b)-(c); (a)-(c)-(d); (a)-(c)-(e); (a)-(c)-(f); (a)-(c)-(g); (in) (a)-(b)-(c)-(d); (a)-(b)-(c)-(e); (a)-(b)-(c)-(f); (a)-(b)-(c)-(g); (a)-(c)-(d)-(e); (a)-(c)-(d)-(f); (a)-(c)-(d)-(g); (a)-(c)-(e)-(f); (a)-(c)-(e)-(g); (iv) (a)-(b)-(c)-(d)-(e); (a)-(b)-(c)-(d)-(f); (a)-(b)-(c)-(d)-(g); (a)-(b)-(c)-(e)-(f); (a)-(b)-(c)-(e)-(g); (a)-(c)-(d)-(e)-(f); (a)-(c)-(d)-(e)-(g); (a)-(c)-(e)-(f)-(g); (v) (a)-(b)-(c)-(d)-(e)-(f); (a)-(b)-(c)-(d)-(e)-(g); and (vi) (a)-(b)-(c)-(d)-(e)-(f)-(g).
[0191] In preferred embodiments of the plastic film according to the invention, the plastic film has a layer structure selected from (i) dehesive-(a)-(c); (ii) dehesive-(a)-(b)-(c); adhesive-(a)-(c)-(d); dehesive-(a)-(c)-(e); adhesive-(a)-(c)-(f); adhesive-(a)-(c)-(g); (iii) dehesive-(a)-(b)-(c)-(d); adhesive-(a)-(b)-(c)-(e); adhesive-(a)-(b)-(c)-(f); adhesive-(a)-(b)-(c)-(g); adhesive-(a)-(c)-(d)-(e); adhesive-(a)-(c)-(d)-(f); adhesive-(a)-(c)-(d)-(g); adhesive-(a)-(c)-(e)-(f); adhesive-(a)-(c)-(e)-(g); (iv) dehesive-(a)-(b)-(c)-(d)-(e); adhesive-(a)-(b)-(c)-(d)-(f); adhesive-(a)-(b)-(c)-(d)-(g); dehesive-(a)-(b)-(c)-(e)-(f); adhesive-(a)-(b)-(c)-(e)-(g); adhesive-(a)-(c)-(d)-(e)-(f); adhesive-(a)-(c)-(d)-(e)-(g); adhesive-(a)-(c)-(e)-(f)-(g); (v) adhesive-(a)-(b)-(c)-(d)-(e)-(f); adhesive-(a)-(b)-(c)-(d)-(e)-(g); and (vi) dehesive-(a)-(b)-(c)-(d)-(e)-(f)-(g); where "dehesive" means a dehesive surface coating.
[0192] In preferred embodiments of the plastic film according to the invention, the plastic film has a layer structure selected from (i) dehesive-(a)-(c)-dehesive; (ii) dehesive-(a)-(b)-(c)-dehesive; dehesive-(a)-(c)-(d)-dehesive; dehesive-(a)-(c)-(e)-dehesive; dehesive-(a)- (c)-(f)-dehesive; dehesive-(a)-(c)-(g)-dehesive; (iii) dehesive-(a)-(b)-(c)-(d)-dehesive; dehesive-(a)-(b)-(c)-(e)-dehesive; dehesive-(a)-(b)-(c)-(f)-dehesive; dehesive-(a)-(b)-(c)-(g)-dehesive; dehesive-(a)-(c)-(d)-(e)-dehesive; dehesive-(a)-(c)-(d)-(f)-dehesive; dehesive-(a)-(c)-(d)-(g)-dehesive; dehesive-(a)-(c)-(e)-(f)-dehesive; dehesive-(a)-(c)-(e)-(g)-dehesive; (iv) dehesive-(a)-(b)-(c)-(d)-(e)-dehesive; dehesive-(a)-(b)-(c)-(d)-(f)-dehesive; dehesive-(a)-(b)-(c)-(d)-(g)- dehesive; dehesive-(a)-(b)-(c)-(e)-(f)-dehesive; dehesive-(a)-(b)-(c)-(e)-(g)-dehesive; dehesive-(a)-(c)- (d)-(e)-(f)-dehesive; dehesive-(a)-(c)-(d)-(e)-(g)-dehesive; dehesive-(a)-(c)-(e)-(f)-(g)-dehesive; (v) dehesive-(a)-(b)-(c)-(d)-(e)-(f)-dehesive; dehesive-(a)-(b)-(c)-(d)-(e)-(g)-dehesive; and (vi) dehesive-(a)-(b)-(c)-(d)-(e)-(f)-(g)-dehesive; where "dehesive" means a dehesive surface coating.
[0193] In preferred embodiments of the plastic film according to the invention, the plastic film has a layer structure selected from (i) dehesive-(a)-(c)-adhesive; (ii) dehesive-(a)-(b)-(c)-adhesive; dehesive-(a)-(c)-(d)-adhesive; dehesive-(a)-(c)-(e)-adhesive; dehesive-(a)- (c)-(f)-adhesive; dehesive-(a)-(c)-(g)-dehesive; (iii) dehesive-(a)-(b)-(c)-(d)-adhesive; dehesive-(a)-(b)-(c)-(e)-adhesive; dehesive-(a)-(b)-(c)-(f)-adhesive; dehesive-(a)-(b)-(c)-(g)-adhesive; dehesive-(a)-(c)-(d)-(e)-adhesive; dehesive-(a)-(c)-(d)-(f)-adhesive; dehesive-(a)-(c)-(d)-(g)-adhesive; dehesive-(a)-(c)-(e)-(f)-adhesive; dehesive-(a)-(c)-(e)-(g)-adhesive; (iv) dehesive-(a)-(b)-(c)-(d)-(e)-adhesive; dehesive-(a)-(b)-(c)-(d)-(f)-adhesive; dehesive-(a)-(b)-(c)-(d)-(g)- adhesive; dehesive-(a)-(b)-(c)-(e)-(f)-adhesive; dehesive-(a)-(b)-(c)-(e)-(g)-adhesive; dehesive-(a)-(c)- (d)-(e)-(f)-adhesive; dehesive-(a)-(c)-(d)-(e)-(g)-adhesive; dehesive-(a)-(c)-(e)-(f)-(g)-adhesive; (v) dehesive-(a)-(b)-(c)-(d)-(e)-(f)-adhesive; dehesive-(a)-(b)-(c)-(d)-(e)-(g)-adhesive; and (vi) dehesive-(a)-(b)-(c)-(d)-(e)-(f)-(g)-adhesive; where "dehesive" stands for a dehesive surface coating and "adhesive" stands for an adhesive surface coating.
[0194] In preferred embodiments of the plastic film according to the invention, the plastic film has a layer structure selected from (i) adhesive-(a)-(c)-dehesive; (ii) adhesive-(a)-(b)-(c)-dehesive; adhesive-(a)-(c)-(d)-dehesive; adhesive-(a)-(c)-(e)-dehesive; adhesive-(a)- (c)-(f)-dehesive; adhesive-(a)-(c)-(g)-dehesive; (iii) adhesive-(a)-(b)-(c)-(d)-dehesive; adhesive-(a)-(b)-(c)-(e)-dehesive; adhesive-(a)-(b)-(c)-(f)-dehesive; adhesive-(a)-(b)-(c)-(g)-dehesive; adhesive-(a)-(c)-(d)-(e)-dehesive; adhesive-(a)-(c)-(d)-(f)-dehesive; adhesive-(a)-(c)-(d)-(g)-dehesive; adhesive-(a)-(c)-(e)-(f)-dehesive; adhesive-(a)-(c)-(e)-(g)-dehesive; (iv) adhesive-(a)-(b)-(c)-(d)-(e)-dehesive; adhesive-(a)-(b)-(c)-(d)-(f)-dehesive; adhesive-(a)-(b)-(c)-(d)-(g)- dehesive; adhesive-(a)-(b)-(c)-(e)-(f)-dehesive; adhesive-(a)-(b)-(c)-(e)-(g)-dehesive; adhesive-(a)-(c)- (d)-(e)-(f)-dehesive; adhesive-(a)-(c)-(d)-(e)-(g)-dehesive; adhesive-(a)-(c)-(e)-(f)-(g)-dehesive; (v) adhesive-(a)-(b)-(c)-(d)-(e)-(f)-dehesive; adhesive-(a)-(b)-(c)-(d)-(e)-(g)-dehesive; and (vi) adhesive-(a)-(b)-(c)-(d)-(e)-(f)-(g)-dehesive; where "dehesive" means a dehesive surface coating and "adhesive" means an adhesive surface coating.
[0195] In further preferred embodiments, the plastic film according to the invention is a plastic film which is surface-coated on at least one side and which - a carrier film with a first outer layer and a second outer layer; - a first surface coating which covers at least part of the first outer layer of the carrier film; and - optionally a second surface coating, which optionally covers at least part of the second outer layer of the carrier film; comprises or consists of; wherein the carrier film (A) optionally a layer (A) which contains or is based on non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide; (B) optionally an adhesion promoter layer (B); (C) optionally a layer (C) which contains or is based on non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide; (D) optionally an adhesion promoter layer (D); and (E) optionally a layer (E) which contains or is based on non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide; (F) optionally an adhesion promoter layer (F); (G) optionally a layer (G) which contains or is based on non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide; (H) optionally comprises or consists of an adhesion promoter layer (H); wherein either the layer (A) or the adhesion promoter layer (B) forms the first outer layer of the carrier film and wherein at least one of the layers (A) to (H) and / or the first surface coating contains water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), optionally in a mixture with non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide.
[0196] The first surface coating and layer (A) or the adhesion promoter layer (B) of the plastic film according to the invention are necessarily present. The second surface coating and layers (C), (D), (E), (F), (G), and (H) are each independently optional. Preferably, the layers present are arranged in alphabetical order.
[0197] According to these embodiments of the invention, at least one of layers (A) to (H) and / or the first surface coating contains a water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), optionally in a mixture with a non-water-soluble polymer, preferably polyolefin, polyester, and / or polyamide. The presence of the water-soluble polymer does not significantly impair the functionality of the plastic film according to the invention or the respective layer when it is used for its intended purpose, e.g., as a release film with release properties. However, if the plastic film according to the invention is recycled, the content of water-soluble polymer in at least one layer (A) to (H) contributes significantly to the creation of a type of "predetermined breaking point" and the ability of individual components of the plastic film to be separated from one another.
[0198] In preferred embodiments, layer (A) and / or layer (C) and / or layer (E) and / or layer (G) each independently contain a mixture of non-water-soluble polymer and water-soluble polymer.
[0199] Preferably, the non-water-soluble polymer is independently selected from the group consisting of polyolefins, polyesters and polyamides.
[0200] Preferably, the water-soluble polymer is selected from polymers or copolymers of vinyl acetate, vinylpyrrolidone, ethylene oxide, acrylamide, and lactic acid; preferably polymers or copolymers of vinyl acetate.
[0201] Preferably, the water-soluble polymer is independently selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polyvinyl alcohol (PVOH), polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyacrylamide (PAM), and polylactic acid (PLA); preferably butenediol-vinyl alcohol copolymer (BVOH).
[0202] Preferably, the water-soluble polymer has an ethylene group content of at most 10 mol%, more preferably at most 5.0 mol%, even more preferably at most 2.5 mol%, and in particular practically no ethylene groups at all.
[0203] Preferably, the water-soluble polymer has a vinyl ester group content of at most 20 mol%, more preferably at most 15 mol%, even more preferably at most 10 mol%, most preferably at most 5.0 mol%, and in particular at most 2.5 mol%.
[0204] The water-soluble polymer preferably has a content of vinyl alcohol groups in the range of 40 to 85 mol%, preferably 50 to 75 mol%.
[0205] The water-soluble polymer preferably has a butylene group content in the range of 15 to 60 mol%, preferably 25 to 50 mol%.
[0206] Preferably, the content of water-soluble polymer is greater than the content of non-water-soluble polymer.
[0207] Preferably, the relative weight ratio of water-soluble polymer to non-water-soluble polymer is in the ratio of 10:1 to 1:10, preferably 8:1 to 1:8, more preferably 6:1 to 1:6, even more preferably 4:1 to 1:4, most preferably 3:1 to 1:3 and especially 2:1 to 1:2.
[0208] Preferably, the relative weight ratio of water-soluble polymer to non-water-soluble polymer is in the ratio of 11:1 to 1:2, preferably 10:1 to 1:1, more preferably 9:1 to 2:1, even more preferably 8:1 to 3:1, most preferably 7:1 to 4:1 and especially 6:1 to 5:1.
[0209] In preferred embodiments, based on the weight of the respective layer (A), (C), (E) or (G) independently of one another - the content of water-soluble polymer in the range of 85±14 wt.%, preferably 85±12 wt.%, more preferably 85±10 wt.%, even more preferably 85±8.0 wt.%, most preferably 85±6.0 wt.%, and in particular 85±4.0 wt.%; and - the content of non-water-soluble polymer in the range of 15±14 wt%, preferably 15±12 wt%, more preferably 15±10 wt%, even more preferably 15±8.0 wt%, most preferably 15±6.0 wt%, and in particular 15±4.0 wt%.
[0210] Preferably, layer (A) and / or layer (C) and / or layer (E) and / or layer (G) each independently have a layer thickness in the range from 0.5 to 100 pm, preferably 0.5 to 25 pm.
[0211] Preferably, layer (A) and / or layer (C) and / or layer (E) and / or layer (G) each independently have a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
[0212] Preferably, layer (A) and / or layer (C) and / or layer (E) and / or layer (G) each independently have a layer thickness of at most 22 pm, more preferably at most 19 pm, even more preferably at most 16 pm, most preferably at most 13 pm and in particular at most 10 pm.
[0213] In preferred embodiments, the adhesion promoter layer (B) and / or the adhesion promoter layer (D) and / or the adhesion promoter layer (F) and / or the adhesion promoter layer (H) each independently contain a mixture of non-water-soluble polymer and water-soluble polymer.
[0214] Preferably, the non-water-soluble polymer is independently selected from anhydride-modified and acid-modified polyolefin.
[0215] Preferably, the water-soluble polymer is selected from polymers or copolymers of vinyl acetate, vinylpyrrolidone, ethylene oxide, acrylamide, and lactic acid; preferably polymers or copolymers of vinyl acetate.
[0216] Preferably, the water-soluble polymer is independently selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polyvinyl alcohol (PVOH), polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyacrylamide (PAM), and polylactic acid (PLA); preferably butenediol-vinyl alcohol copolymer (BVOH).
[0217] Preferably, the water-soluble polymer has an ethylene group content of at most 10 mol%, more preferably at most 5.0 mol%, even more preferably at most 2.5 mol%, and in particular practically no ethylene groups at all.
[0218] Preferably, the water-soluble polymer has a vinyl ester group content of at most 20 mol%, more preferably at most 15 mol%, even more preferably at most 10 mol%, most preferably at most 5.0 mol%, and in particular at most 2.5 mol%.
[0219] The water-soluble polymer preferably has a content of vinyl alcohol groups in the range of 40 to 85 mol%, preferably 50 to 75 mol%.
[0220] The water-soluble polymer preferably has a butylene group content in the range of 15 to 60 mol%, preferably 25 to 50 mol%.
[0221] Preferably, the content of water-soluble polymer is greater than the content of non-water-soluble polymer.
[0222] Preferably, the relative weight ratio of water-soluble polymer to non-water-soluble polymer is in the ratio of 10:1 to 1:10, preferably 8:1 to 1:8, more preferably 6:1 to 1:6, even more preferably 4:1 to 1:4, most preferably 3:1 to 1:3 and especially 2:1 to 1:2.
[0223] Preferably, the relative weight ratio of water-soluble polymer to non-water-soluble polymer is in the ratio of 11:1 to 1:2, preferably 10:1 to 1:1, more preferably 9:1 to 2:1, even more preferably 8:1 to 3:1, most preferably 7:1 to 4:1 and especially 6:1 to 5:1.
[0224] In preferred embodiments, based on the weight of the respective adhesion promoter layer (B), (D), (F) or (H) independently of one another - the content of water-soluble polymer in the range of 85±14 wt.%, preferably 85±12 wt.%, more preferably 85±10 wt.%, even more preferably 85±8.0 wt.%, most preferably 85±6.0 wt.%, and in particular 85±4.0 wt.%; and - the content of non-water-soluble polymer in the range of 15±14 wt%, preferably 15±12 wt%, more preferably 15±10 wt%, even more preferably 15±8.0 wt%, most preferably 15±6.0 wt%, and in particular 15±4.0 wt%.
[0225] Preferably, the adhesion promoter layer (B) and / or the adhesion promoter layer (D) and / or the adhesion promoter layer (F) and / or the adhesion promoter layer (H) each independently have a layer thickness in the range from 0.5 to 25 pm, preferably 0.5 to 10 pm.
[0226] Preferably, the adhesion promoter layer (B) and / or the adhesion promoter layer (D) and / or the adhesion promoter layer (F) and / or the adhesion promoter layer (H) each independently have a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
[0227] Preferably, the adhesion promoter layer (B) and / or the adhesion promoter layer (D) and / or the adhesion promoter layer (F) and / or the adhesion promoter layer (H) each independently have a layer thickness of at most 9.0 pm, more preferably at most 8.0 pm, even more preferably at most 7.0 pm, most preferably at most 6.0 pm and in particular at most 5.0 pm.
[0228] Preferably, layer (B) is arranged between layer (A) and layer (C); preferably, it is in direct contact with layer (A) and / or layer (C).
[0229] Preferably, layer (C) is arranged between layer (B) and layer (D); preferably, it is in direct contact with layer (B) and / or with layer (D).
[0230] Preferably, layer (D) is arranged between layer (C) and layer (E); preferably, it is in direct contact with layer (C) and / or with layer (E).
[0231] Preferably, layer (E) is arranged between layer (D) and layer (F); preferably, it is in direct contact with layer (D) and / or with layer (F).
[0232] Preferably, layer (F) is arranged between layer (E) and layer (G); preferably, it is in direct contact with layer (E) and / or with layer (G).
[0233] Preferably, layer (G) is arranged between layer (F) and layer (H); preferably, it is in direct contact with layer (F) and / or with layer (H).
[0234] In preferred embodiments, the plastic film according to the invention has the following structure: - first surface coating; - adhesion promoter layer (B), which forms the first outer layer of the carrier film; wherein the adhesion promoter layer (B) is preferably based on a water-soluble polymer which is present in a mixture with an adhesion promoter; - layer (C) which contains or is based on non-water-soluble polymer, preferably polypropylene; - adhesion promoter layer (D); wherein the adhesion promoter layer (D) is preferably based on a water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), which is present in a mixture with an adhesion promoter; - layer (E) which contains or is based on non-water-soluble polymer, preferably polyamide; - adhesion promoter layer (F); wherein the adhesion promoter layer (F) is preferably based on a water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), which is present in a mixture with an adhesion promoter; - layer (G) which contains or is based on non-water-soluble polymer, preferably polypropylene; - adhesion promoter layer (H); wherein the adhesion promoter layer (H) is preferably based on a water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), which is present in a mixture with an adhesion promoter; and - second surface coating.
[0235] In preferred embodiments, the first surface coating contains a mixture of polysiloxane and water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH).
[0236] The polysiloxane is preferably selected from the group consisting of addition-crosslinked, preferably metal-catalyzed addition-crosslinked, condensation-crosslinked, radically crosslinked, and / or cationically crosslinked polysiloxanes.
[0237] Preferably, the polysiloxane is selected from the group consisting of polydialkylsiloxanes, preferably polydimethylsiloxanes, and polyalkylarylsiloxanes, preferably polymethylphenylsiloxanes.
[0238] Preferably, the water-soluble polymer is selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polyvinyl alcohol (PVOH), polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyacrylamide (PAM), and polylactic acid (PLA); preferably butenediol-vinyl alcohol copolymer (BVOH).
[0239] Preferably, the relative weight ratio of water-soluble polymer to polysiloxane is in the ratio of 10:1 to 1:10, preferably 8:1 to 1:8, more preferably 6:1 to 1:6, even more preferably 4:1 to 1:4, most preferably 3:1 to 1:3 and in particular 2:1 to 1:2.
[0240] In preferred embodiments, the total content of water-soluble polymer contained in the plastic film, based on the total weight of the plastic film, is at least 0.5 wt.%, more preferably at least 1.0 wt.%, even more preferably at least 2.0 wt.%, most preferably at least 3.0 wt.% and in particular at least 4.0 wt.%.
[0241] In preferred embodiments, the total content of water-soluble polymer contained in the plastic film, based on the total weight of the plastic film, is at most 18 wt.%, more preferably at most 16 wt.%, even more preferably at most 14 wt.%, most preferably at most 12 wt.% and in particular at most 10 wt.%.
[0242] In preferred embodiments, the total content of water-soluble polymer contained in the plastic film, based on the total weight of the plastic film, is at most 10 wt.%, more preferably at most 9.0 wt.%, even more preferably at most 8.0 wt.%, most preferably at most 7.0 wt.% and in particular at most 6.0 wt.%.
[0243] All layers of the carrier film according to the invention can contain conventional additives in conventional amounts. Conventional additives are selected from the group consisting of fillers, such as CaCO3, phyllosilicates such as talc, plasticizers; lubricants; emulsifiers; pigments; rheology additives; catalysts; flow control agents; impact modifiers; optical brighteners; light stabilizers; antioxidants; clarifying agents such as substituted or unsubstituted bisbenzylidene sorbitols; flame retardants; antistatic agents; UV absorbers such as benzoxazinones; blowing agents; and thiosynergists such as thiodipropionic acid dilauryl esters or thiodipropionic acid distearyl esters. A preferred plasticizer for water-soluble polymers is glycerol.
[0244] The carrier layer according to the invention can be produced by conventional methods known to those skilled in the art and subsequently provided with the first surface coating on the first outer side. Preferred methods are blown film extrusion or casting processes.
[0245] The layers can be applied to the substrate (precursor of the carrier film) by coextrusion (film extrusion), as a polymer coating (extrusion coating), or as a standalone coating (coating, printing, varnish) prior to the first and, if applicable, second surface coating (silicone, adhesive, etc.). Additional adjustments familiar to those skilled in the art, such as corona treatment, may be necessary to ensure sufficient bonding.
[0246] The plastic film according to the invention can be subjected to conventional recycling processes, which typically involve treatment in a water bath. The inventive structure of the plastic film makes it possible to dissolve the water-soluble layer or the water-soluble polymers (almost) completely during the recycling process. As a result, the first and second surface coatings (silicone, adhesive, etc.) lose their adhesion to the substrate and are washed away. The substrate, as the main raw material, can then be separated from the wash water, for example, by density gradients. The detached surface coating is considered a contaminant and removed or otherwise processed. The resulting aqueous waste, which contains the water-soluble polymer, is easy to dispose of if biodegradable and environmentally safe materials are used and does not negatively impact the sustainability of the new film design.
[0247] A further aspect of the invention relates to a process for producing a plastic film according to the invention as described above by blown film coextrusion.
[0248] In the process according to the invention, the extrusion of the plastic film preferably takes place in one step.
[0249] A further aspect of the invention relates to a plastic film obtainable by the inventive method described above.
[0250] A further aspect of the invention relates to the use of the above-described inventive plastic film for recycling some of its components. Preferably, after or during treatment in a water bath, optionally at elevated temperature and after a sufficient exposure time, the plastic film is split along at least one layer containing or based on a water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH).
[0251] The functioning of the invention is explained schematically using Figures 1 and 2.
[0252] Figure 1 shows schematically a cross-section of a plastic film according to the invention with a first surface coating (1), a water-soluble polymer, e.g. BVOH / PVOH based layer (2), a layer (3) based on an adhesion promoter, e.g. PP+MAH, and a layer (4) based on a non-water-soluble polymer, e.g. PA.
[0253] Figure 2 shows the treatment of the plastic film shown in Figure 1 in a container (5) filled with warm water (6). The water-soluble polymer dissolves in the water (6), dissolving the water-soluble polymer-based layer (2). As a result, the first surface coating (1) detaches, floats to the water surface, and can be separately disposed of or recycled. The separated composite, consisting of the adhesion promoter-based layer (3) and a non-water-soluble polymer-based layer (4), can then be recycled.
[0254] The following examples serve to illustrate the invention but are not to be construed as limiting. Example 1:
[0255] Multilayer carrier films are produced by blown film co-extrusion and then coated on one side with a cured polysiloxane adhesive. The individual layers are directly adjacent to each other in the order listed in the table below: Example 2:
[0257] Multilayer carrier films are produced by blown film co-extrusion and then coated on one side with a cured polysiloxane adhesive. The individual layers are directly adjacent to each other in the order listed in the table below: Example 3:
[0258] Multilayer carrier films are produced by blown film co-extrusion and then coated on one side with a cured polysiloxane coating (dehesive) and a pressure-sensitive adhesive (adhesive). The individual layers are directly adjacent to one another in the order listed in the table below: Example 4:
[0259] Multilayer carrier films are produced by blown film co-extrusion and then coated on one side with a cured polysiloxane adhesive. The individual layers are directly adjacent to each other in the order listed in the table below: Example 5:
[0260] Multilayer carrier films are produced by blown film co-extrusion and then coated on one side with a cured polysiloxane coating (dehesive) and a pressure-sensitive adhesive (adhesive). The individual layers are directly adjacent to one another in the order listed in the table below: Example 6:
[0261] A multilayer carrier film is produced by blown film co-extrusion and then coated on one side with a cured polysiloxane coating (dehesive) and a pressure-sensitive adhesive (adhesive). The individual layers are directly adjacent to one another in the order listed in the table below:
Claims
Patent claims:
1. A plastic film with a surface coating on at least one side, which - a carrier film with a first outer layer and a second outer layer; - a first surface coating which covers at least part of the first outer layer of the carrier film; and - optionally a second surface coating, which optionally covers at least part of the second outer layer of the carrier film; comprises or consists of; wherein - the carrier film comprises at least one layer which contains or is based on a non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide; and - the plastic film contains water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), more preferably butenediol-vinyl alcohol copolymer (BVOH); where (i) the carrier film comprises at least one layer which contains or is based on water-soluble polymer, and / or (ii) the first surface coating contains or is based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH).
2. The plastic film according to claim 1, wherein the first surface coating is adhesive.
3. The plastic film according to claim 1 or 2, wherein the first surface coating is based on polysiloxane.
4. The plastic film according to one of the preceding claims, wherein the first surface coating is based on at least one cured polysiloxane, which is preferably selected from the group consisting of addition-crosslinked, preferably metal-catalyzed addition-crosslinked, condensation-crosslinked, radically crosslinked, and / or cationically crosslinked polysiloxanes.
5. The plastic film according to one of the preceding claims, wherein the first surface coating is based on at least one cured polysiloxane, which is preferably selected from the group consisting of polydialkylsiloxanes, preferably polydimethylsiloxanes, and polyalkylarylsiloxanes, preferably polymethylphenylsiloxanes.
6. The plastic film of claim 1, wherein the first surface coating is adhesive.
7. The plastic film according to claim 6, wherein the first surface coating is based on a pressure-sensitive adhesive.
8. The plastic film according to claim 7, wherein the pressure-sensitive adhesive is selected from the group consisting of acrylate-based pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, polyisobutylene-based pressure-sensitive adhesives, and hot melts.
9. The plastic film according to claim 1, wherein the first surface coating is based on printing ink or varnish.
10. The plastic film according to any one of the preceding claims, wherein the first surface coating (i) is non-adhesive and has a surface weight of not more than 5.0 g / m 2 , preferably not more than 4.0 g / m 2 , more preferably not more than 3.0 g / m 2 , most preferably not more than 2.0 g / m 2 and in particular not more than 1.0 g / m 2 or (ii) is adhesive and has a surface weight of not more than 100 g / m 2 , preferably not more than 80 g / m 2 , more preferably not more than 60 g / m 2 , preferably not more than 40 g / m 2 and in particular not more than 20 g / m 2 has.
11. The plastic film according to any one of the preceding claims, wherein the second surface coating is adhesive.
12. The plastic film according to any one of the preceding claims, wherein the second surface coating is based on polysiloxane.
13. The plastic film according to one of the preceding claims, wherein the second surface coating is based on at least one cured polysiloxane, which is preferably selected from the group consisting of addition-crosslinked, preferably metal-catalyzed addition-crosslinked, condensation-crosslinked, radically crosslinked, and / or cationically crosslinked polysiloxanes.
14. The plastic film according to one of the preceding claims, wherein the second surface coating is based on at least one cured polysiloxane, which is preferably selected from the group consisting of polydialkylsiloxanes, preferably polydimethylsiloxanes, and polyalkylarylsiloxanes, preferably polymethylphenylsiloxanes.
15. The plastic film according to any one of claims 1 to 10, wherein the second surface coating is adhesive.
16. The plastic film of claim 15, wherein the second surface coating is based on a pressure-sensitive adhesive.
17. The plastic film according to claim 16, wherein the pressure-sensitive adhesive is selected from the group consisting of acrylate-based pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, polyisobutylene-based pressure-sensitive adhesives, and hot melts.
18. The plastic film according to any one of claims 1 to 10, wherein the second surface coating is based on printing ink or varnish.
19. The plastic film according to any one of the preceding claims, wherein the second surface coating (i) is non-adhesive and has a surface weight of not more than 5.0 g / m 2 , preferably not more than 4.0 g / m 2 , more preferably not more than 3.0 g / m 2 , most preferably not more than 2.0 g / m 2 and in particular not more than 1.0 g / m 2 or (ii) is adhesive and has a surface weight of not more than 100 g / m 2 , preferably not more than 80 g / m 2 , more preferably not more than 60 g / m 2 , preferably not more than 40 g / m 2 and in particular not more than 20 g / m 2 has.
20. The plastic film according to one of the preceding claims, wherein the plastic film has a total layer thickness in the range of 10 to 250 pm.
21. The plastic film according to any one of the preceding claims, wherein the plastic film has a total layer thickness of at least 20 pm, more preferably at least 25 pm, even more preferably at least 30 pm, most preferably at least 35 pm and in particular at least 40 pm.
22. The plastic film according to any one of the preceding claims, wherein the plastic film has a total layer thickness of at most 90 pm, more preferably at most 80 pm, even more preferably at most 70 pm, most preferably at most 60 pm and in particular at most 50 pm.
23. The plastic film according to one of the preceding claims, which is extrudable, preferably coextrudable in one step, preferably by blown film coextrusion.
24. The plastic film according to one of the preceding claims, wherein the carrier film has a symmetrical layer structure.
25. The plastic film according to any one of the preceding claims, wherein the carrier film (a) a layer (a) which is based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), and forms the first outer layer of the carrier film; (b) optionally an adhesion promoter layer (b); (c) a layer (c) based on non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide; (d) optionally an adhesion promoter layer (d); (e) optionally a layer (e) based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH); (f) optionally a layer (f) based on non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide; (g) optionally comprising or consisting of a layer (g) based on a water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH).
26. The plastic film according to claim 25, wherein layer (a) is based on extrudable, water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH).
27. The plastic film according to claim 25 or 26, wherein the layer (a) is based on one or more water-soluble polymers independently selected from (i) fully synthetic water-soluble polymers; (ii) semi-synthetic or natural water-soluble polymers.
28. The plastic film according to any one of claims 25 to 27, wherein layer (a) is based on one or more water-soluble polymers selected from polymers or copolymers of vinyl acetate, vinylpyrrolidone, ethylene oxide, acrylamide, and lactic acid; preferably polymers or copolymers of vinyl acetate.
29. The plastic film according to any one of claims 25 to 28, wherein layer (a) is based on one or more water-soluble polymers independently selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polyvinyl alcohol (PVOH), polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyacrylamide (PAM), and polylactic acid (PLA); preferably butenediol-vinyl alcohol copolymer (BVOH).
30. The plastic film according to any one of claims 25 to 29, wherein layer (a) is based on one or more water-soluble polymers having an ethylene group content of at most 10 mol%, more preferably at most 5.0 mol%, even more preferably at most 2.5 mol%, and in particular practically no ethylene groups at all.
31. The plastic film according to any one of claims 25 to 30, wherein layer (a), based on the total weight of layer (a), contains at least 50 wt.% water-soluble polymer, more preferably at least 60 wt.%, even more preferably at least 70 wt.%, most preferably at least 80 wt.% and in particular at least 90 wt.%.
32. The plastic film according to any one of claims 25 to 31, wherein layer (a), based on the total weight of layer (a), contains at most 10 wt.% of non-water-soluble polymer, more preferably 5 wt.%, even more preferably at most 2.5 wt.%, most preferably at most 1.0 wt.%, and in particular practically no non-water-soluble polymer.
33. The plastic film according to any one of claims 25 to 32, wherein layer (a) has a layer thickness in the range of 0.5 to 100 pm, preferably 0.5 to 25 pm.
34. The plastic film according to any one of claims 25 to 33, wherein the layer (a) has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
35. The plastic film according to any one of claims 25 to 34, wherein the layer (a) has a layer thickness of at most 22 pm, more preferably at most 19 pm, even more preferably at most 16 pm, most preferably at most 13 pm and in particular at most 10 pm.
36. The plastic film according to any one of claims 25 to 35, wherein the layer (a) has a layer thickness of at most 9.0 pm, more preferably at most 8.0 pm, even more preferably at most 7.0 pm, most preferably at most 6.0 pm and in particular at most 5.0 pm.
37. The plastic film according to any one of claims 25 to 36, wherein the layer (a) has a layer thickness of at most 4.0 pm, more preferably at most 3.0 pm, even more preferably at most 2.5 pm, most preferably at most 2.0 pm and in particular at most 1.75 pm.
38. The plastic film according to any one of claims 25 to 37, wherein the adhesion promoter layer (b) is based on anhydride-modified or acid-modified polyolefin.
39. The plastic film according to claim 38, wherein the adhesion promoter layer (b) contains, in addition to the anhydride-modified or acid-modified polyolefin, further polymers, preferably the same water-soluble polymer which is contained in layer (a) and / or the same non-water-soluble polymer which is contained in layer (c).
40. The plastic film according to any one of claims 25 to 39, wherein the adhesion promoter layer (b), based on the total weight of the adhesion promoter layer (b), contains at least 30 wt.% non-water-soluble polymer, more preferably at least 40 wt.%, even more preferably at least 50 wt.%, most preferably at least 60 wt.% and in particular at least 70 wt.%.
41. The plastic film according to any one of claims 25 to 40, wherein the adhesion promoter layer (b) has a layer thickness in the range of 0.5 to 25 pm, preferably 0.5 to 10 pm.
42. The plastic film according to any one of claims 25 to 41, wherein the adhesion promoter layer (b) has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
43. The plastic film according to any one of claims 25 to 42, wherein the adhesion promoter layer (b) has a layer thickness of at most 9.0 pm, more preferably at most 8.0 pm, even more preferably at most 7.0 pm, most preferably at most 6.0 pm and in particular at most 5.0 pm.
44. The plastic film according to any one of claims 25 to 43, wherein layer (c) is based on one or more non-water-soluble polymers independently selected from the group consisting of polyolefins, polyesters and polyamides.
45. The plastic film according to any one of claims 25 to 44, wherein the layer (c) is based on one or more non-water-soluble polymers independently selected from the group consisting of thermoplastic olefin homopolymers; and / or thermoplastic olefin copolymers of α,β-unsaturated olefins having 2 to 10 carbon atoms.
46. The plastic film according to any one of claims 25 to 45, wherein the layer (c) is based on one or more non-water-soluble polymers independently selected from the group consisting of polyethylene, polypropylene, polybutylene, polyisobutylene (PI), copolymers and / or mixtures of at least two of said polymers.
47. The plastic film according to any one of claims 25 to 46, wherein layer (c), based on the total weight of layer (c), contains at least 50 wt% of non-water-soluble polymer, more preferably at least 60 wt%, even more preferably at least 70 wt%, most preferably at least 80 wt% and in particular at least 90 wt%.
48. The plastic film according to any one of claims 25 to 47, wherein layer (c), based on the total weight of layer (a), contains at most 10 wt.% water-soluble polymer, more preferably 5 wt.%, even more preferably at most 2.5 wt.%, most preferably at most 1.0 wt.%, and in particular practically no water-soluble polymer at all.
49. The plastic film according to any one of claims 25 to 48, wherein the layer (c) has a layer thickness in the range of 0.5 to 100 pm, preferably 0.5 to 25 pm.
50. The plastic film according to any one of claims 25 to 49, wherein the layer (c) has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
51. The plastic film according to any one of claims 25 to 50, wherein the layer (c) has a layer thickness of at most 22 pm, more preferably at most 19 pm, even more preferably at most 16 pm, most preferably at most 13 pm and in particular at most 10 pm.
52. The plastic film according to any one of claims 25 to 51, wherein the adhesion promoter layer (d) is based on anhydride-modified or acid-modified polyolefin.
53. The plastic film according to claim 52, wherein the adhesion promoter layer (d) contains, in addition to the anhydride-modified or acid-modified polyolefin, further polymers, preferably the same water-soluble polymer which is contained in layer (e) and / or the same non-water-soluble polymer which is contained in layer (c).
54. The plastic film according to any one of claims 25 to 53, wherein the adhesion promoter layer (d), based on the total weight of the adhesion promoter layer (d), contains at least 30 wt.% non-water-soluble polymer, more preferably at least 40 wt.%, even more preferably at least 50 wt.%, most preferably at least 60 wt.% and in particular at least 70 wt.%.
55. The plastic film according to one of claims 25 to 54, wherein the adhesion promoter layer (d) has a layer thickness in the range of 0.5 to 25 pm, preferably 0.5 to 10 pm.
56. The plastic film according to any one of claims 25 to 55, wherein the adhesion promoter layer (d) has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
57. The plastic film according to any one of claims 25 to 56, wherein the adhesion promoter layer (d) has a layer thickness of at most 9.0 pm, more preferably at most 8.0 pm, even more preferably at most 7.0 pm, most preferably at most 6.0 pm and in particular at most 5.0 pm.
58. The plastic film according to one of claims 25 to 57, wherein the adhesion promoter layer (d) has the same layer structure as the adhesion promoter layer (b).
59. The plastic film according to one of claims 25 to 58, wherein the adhesion promoter layer (d) has a different layer structure than the adhesion promoter layer (b).
60. The plastic film according to any one of claims 25 to 59, wherein the layer (e) is based on extrudable, water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH).
61. The plastic film according to any one of claims 25 to 60, wherein the layer (e) is based on one or more water-soluble polymers independently selected from (i) fully synthetic water-soluble polymers; and (ii) semi-synthetic or natural water-soluble polymers.
62. The plastic film according to any one of claims 25 to 61, wherein the layer (e) is based on one or more water-soluble polymers selected from polymers or copolymers of Vinyl acetate, vinylpyrrolidone, ethylene oxide, acrylamide, and lactic acid; preferably polymers or copolymers of vinyl acetate.
63. The plastic film according to any one of claims 25 to 62, wherein the layer (e) is based on one or more water-soluble polymers independently selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polyvinyl alcohol (PVOH), polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyacrylamide (PAM), and polylactic acid (PLA); preferably butenediol-vinyl alcohol copolymer (BVOH).
64. The plastic film according to any one of claims 25 to 63, wherein the layer (e) is based on one or more water-soluble polymers having an ethylene group content of at most 10 mol%, more preferably at most 5.0 mol%, even more preferably at most 2.5 mol%, and in particular practically no ethylene groups at all.
65. The plastic film according to any one of claims 25 to 64, wherein the layer (e), based on the total weight of the layer (e), contains at least 50 wt.% water-soluble polymer, more preferably at least 60 wt.%, even more preferably at least 70 wt.%, most preferably at least 80 wt.% and in particular at least 90 wt.%.
66. The plastic film according to any one of claims 25 to 65, wherein the layer (e), based on the total weight of the layer (e), contains at most 10 wt.% of non-water-soluble polymer, more preferably 5 wt.%, even more preferably at most 2.5 wt.%, most preferably at most 1.0 wt.%, and in particular practically no non-water-soluble polymer.
67. The plastic film according to any one of claims 25 to 66, wherein the layer (e) has a layer thickness in the range of 0.5 to 100 pm, preferably 0.5 to 25 pm.
68. The plastic film according to any one of claims 25 to 67, wherein the layer (e) has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
69. The plastic film according to any one of claims 25 to 68, wherein the layer (e) has a layer thickness of at most 22 pm, more preferably at most 19 pm, even more preferably at most 16 pm, most preferably at most 13 pm and in particular at most 10 pm.
70. The plastic film according to any one of claims 25 to 69, wherein the layer (e) has a layer thickness of at most 9.0 pm, more preferably at most 8.0 pm, even more preferably at most 7.0 pm, most preferably at most 6.0 pm and in particular at most 5.0 pm.
71. The plastic film according to any one of claims 25 to 70, wherein the layer (e) has a layer thickness of at most 4.0 pm, more preferably at most 3.0 pm, even more preferably at most 2.5 pm, most preferably at most 2.0 pm and in particular at most 1.75 pm.
72. The plastic film according to any one of claims 25 to 71, wherein layer (e) has the same layer structure as layer (a).
73. The plastic film according to any one of claims 25 to 72, wherein layer (e) has a different layer structure than layer (a).
74. The plastic film according to any one of claims 25 to 73, wherein layer (f) is based on one or more non-water-soluble polymers independently selected from the group consisting of polyolefins, polyesters and polyamides.
75. The plastic film according to any one of claims 25 to 74, wherein the layer (f) is based on one or more non-water-soluble polymers independently selected from the group consisting of - thermoplastic olefin homopolymers; and / or - thermoplastic olefin copolymers of α,β-unsaturated olefins having 2 to 10 carbon atoms.
76. The plastic film according to any one of claims 25 to 75, wherein the layer (f) is based on one or more non-water-soluble polymers independently selected from the group consisting of polyethylene, polypropylene, polybutylene, polyisobutylene (PI), copolymers and / or mixtures of at least two of said polymers.
77. The plastic film according to any one of claims 25 to 76, wherein the layer (f), based on the total weight of the layer (f), contains at least 50 wt.% of non-water-soluble polymer, more preferably at least 60 wt.%, even more preferably at least 70 wt.%, most preferably at least 80 wt.% and in particular at least 90 wt.%.
78. The plastic film according to any one of claims 25 to 77, wherein the layer (f), based on the total weight of the layer (f), contains at most 10 wt.% water-soluble polymer, more preferably 5 % by weight, more preferably at most 2.5 % by weight, most preferably at most 1.0 % by weight, and in particular contains practically no water-soluble polymer at all.
79. The plastic film according to any one of claims 25 to 78, wherein the layer (f) has a layer thickness in the range of 0.5 to 100 pm, preferably 0.5 to 25 pm.
80. The plastic film according to any one of claims 25 to 79, wherein the layer (f) has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
81. The plastic film according to any one of claims 25 to 80, wherein the layer (f) has a layer thickness of at most 22 pm, more preferably at most 19 pm, even more preferably at most 16 pm, most preferably at most 13 pm and in particular at most 10 pm.
82. The plastic film according to any one of claims 25 to 81, wherein layer (f) has the same layer structure as layer (c).
83. The plastic film according to any one of claims 25 to 82, wherein layer (f) has a different layer structure than layer (c).
84. The plastic film according to any one of claims 25 to 83, wherein the layer (g) is based on extrudable, water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH).
85. The plastic film according to any one of claims 25 to 84, wherein the layer (g) is based on one or more water-soluble polymers independently selected from (i) fully synthetic water-soluble polymers; and (ii) semi-synthetic or natural water-soluble polymers.
86. The plastic film according to any one of claims 25 to 85, wherein layer (g) is based on one or more water-soluble polymers selected from polymers or copolymers of vinyl acetate, vinylpyrrolidone, ethylene oxide, acrylamide, and lactic acid; preferably polymers or copolymers of vinyl acetate.
87. The plastic film according to any one of claims 25 to 86, wherein the layer (g) is based on one or more water-soluble polymers independently selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polyvinyl alcohol (PVOH), Polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyacrylamide (PAM), and polylactic acid (PLA); preferably butenediol-vinyl alcohol copolymer (BVOH).
88. The plastic film according to any one of claims 25 to 87, wherein the layer (g) is based on one or more water-soluble polymers having an ethylene group content of at most 10 mol%, more preferably at most 5.0 mol%, even more preferably at most 2.5 mol%, and in particular practically no ethylene groups at all.
89. The plastic film according to any one of claims 25 to 88, wherein the layer (g), based on the total weight of the layer (g), contains at least 50 wt.% water-soluble polymer, more preferably at least 60 wt.%, even more preferably at least 70 wt.%, most preferably at least 80 wt.% and in particular at least 90 wt.%.
90. The plastic film according to any one of claims 25 to 89, wherein the layer (g), based on the total weight of the layer (g), contains at most 10 wt.% of non-water-soluble polymer, more preferably 5 wt.%, even more preferably at most 2.5 wt.%, most preferably at most 1.0 wt.%, and in particular practically no non-water-soluble polymer at all.
91. The plastic film according to any one of claims 25 to 90, wherein the layer (g) has a layer thickness in the range of 0.5 to 100 pm, preferably 0.5 to 25 pm.
92. The plastic film according to any one of claims 25 to 91, wherein the layer (g) has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
93. The plastic film according to any one of claims 25 to 92, wherein the layer (g) has a layer thickness of at most 22 pm, more preferably at most 19 pm, even more preferably at most 16 pm, most preferably at most 13 pm and in particular at most 10 pm.
94. The plastic film according to any one of claims 25 to 93, wherein the layer (g) has a layer thickness of at most 9.0 pm, more preferably at most 8.0 pm, even more preferably at most 7.0 pm, most preferably at most 6.0 pm and in particular at most 5.0 pm.
95. The plastic film according to any one of claims 25 to 94, wherein the layer (g) has a layer thickness of at most 4.0 pm, more preferably at most 3.0 pm, even more preferably at most 2.5 pm, most preferably at most 2.0 pm and in particular at most 1.75 pm.
96. The plastic film according to any one of claims 25 to 95, wherein layer (g) has the same layer structure as layer (e).
97. The plastic film according to any one of claims 25 to 96, wherein layer (g) has a different layer structure than layer (e).
98. The plastic film according to any one of claims 25 to 97, wherein the carrier film has a layer structure selected from (i) (a)-(c); (ii) (a)-(b)-(c); (a)-(c)-(d); (a)-(c)-(e); (a)-(c)-(f); (a)-(c)-(g); (in) (a)-(b)-(c)-(d); (a)-(b)-(c)-(e); (a)-(b)-(c)-(f); (a)-(b)-(c)-(g); (a)-(c)-(d)-(e); (a)-(c)-(d)-(f); (a)-(c)-(d)-(g); (a)-(c)-(e)-(f); (a)-(c)-(e)-(g); (iv) (a)-(b)-(c)-(d)-(e); (a)-(b)-(c)-(d)-(f); (a)-(b)-(c)-(d)-(g); (a)-(b)-(c)-(e)-(f); (a)-(b)-(c)-(e)-(g); (a)-(c)-(d)-(e)-(f); (a)-(c)-(d)-(e)-(g); (a)-(c)-(e)-(f)-(g); (v) (a)-(b)-(c)-(d)-(e)-(f); (a)-(b)-(c)-(d)-(e)-(g); and (vi) (a)-(b)-(c)-(d)-(e)-(f)-(g).
99. The plastic film according to any one of claims 25 to 98, wherein the plastic film has a layer structure selected from (i) dehesive-(a)-(c); (ii) dehesive-(a)-(b)-(c); adhesive-(a)-(c)-(d); dehesive-(a)-(c)-(e); dehesive-(a)-(c)-(f); adhesive-(a)-(c)-(g); (iii) dehesive-(a)-(b)-(c)-(d); adhesive-(a)-(b)-(c)-(e); adhesive-(a)-(b)-(c)-(f); adhesive-(a)-(b)-(c)-(g); adhesive-(a)-(c)-(d)-(e); adhesive-(a)-(c)-(d)-(f); adhesive-(a)-(c)-(d)-(g); adhesive-(a)-(c)-(e)-(f); adhesive-(a)-(c)-(e)-(g); (iv) dehesive-(a)-(b)-(c)-(d)-(e); adhesive-(a)-(b)-(c)-(d)-(f); adhesive-(a)-(b)-(c)-(d)-(g); adhesive- (a)-(b)-(c)-(e)-(f); adhesive-(a)-(b)-(c)-(e)-(g); adhesive-(a)-(c)-(d)-(e)-(f); adhesive-(a)-(c)-(d)-(e)-(g); adhesive-(a)-(c)-(e)-(f)-(g); (v) adhesive-(a)-(b)-(c)-(d)-(e)-(f); adhesive-(a)-(b)-(c)-(d)-(e)-(g); and (vi) dehesive-(a)-(b)-(c)-(d)-(e)-(f)-(g); where "dehesive" means a dehesive surface coating.
100. The plastic film according to any one of claims 25 to 99, wherein the plastic film has a layer structure selected from (i) dehesive-(a)-(c)-dehesive; (ii) dehesive-(a)-(b)-(c)-dehesive; dehesive-(a)-(c)-(d)-dehesive; dehesive-(a)-(c)-(e)-dehesive; dehesive-(a)-(c)-(f)-dehesive; dehesive-(a)-(c)-(g)-dehesive; (iii) dehesive-(a)-(b)-(c)-(d)-dehesive; dehesive-(a)-(b)-(c)-(e)-dehesive; dehesive-(a)-(b)-(c)-(f)- dehesive; dehesive-(a)-(b)-(c)-(g)-dehesive; dehesive-(a)-(c)-(d)-(e)-dehesive; dehesive-(a)-(c)-(d)-(f)-dehesive; dehesive-(a)-(c)-(d)-(g)-dehesive; dehesive-(a)-(c)-(e)-(f)-dehesive; dehesive-(a)- (c)-(e)-(g)-releasable; (iv) dehesive-(a)-(b)-(c)-(d)-(e)-dehesive; dehesive-(a)-(b)-(c)-(d)-(f)-dehesive; dehesive-(a)-(b)-(c)- (d)-(g)-dehesive; dehesive-(a)-(b)-(c)-(e)-(f)-dehesive; dehesive-(a)-(b)-(c)-(e)-(g)-dehesive; dehesive-(a)-(c)-(d)-(e)-(f)-dehesive; dehesive-(a)-(c)-(d)-(e)-(g)-dehesive; dehesive-(a)-(c)-(e)-(f)-(g)-dehesive; (v) dehesive-(a)-(b)-(c)-(d)-(e)-(f)-dehesive; dehesive-(a)-(b)-(c)-(d)-(e)-(g)-dehesive; and (vi) dehesive-(a)-(b)-(c)-(d)-(e)-(f)-(g)-dehesive; where "dehesive" means a dehesive surface coating.
101. The plastic film according to any one of claims 25 to 100, wherein the plastic film has a layer structure selected from (i) dehesive-(a)-(c)-adhesive; (ii) dehesive-(a)-(b)-(c)-adhesive; dehesive-(a)-(c)-(d)-adhesive; dehesive-(a)-(c)-(e)-adhesive; dehesive-(a)-(c)-(f)-adhesive; dehesive-(a)-(c)-(g)-dehesive; (iii) dehesive-(a)-(b)-(c)-(d)-adhesive; dehesive-(a)-(b)-(c)-(e)-adhesive; dehesive-(a)-(b)-(c)-(f)- adhesive; dehesive-(a)-(b)-(c)-(g)-adhesive; dehesive-(a)-(c)-(d)-(e)-adhesive; dehesive-(a)-(c)-(d)-(f)-adhesive; dehesive-(a)-(c)-(d)-(g)-adhesive; dehesive-(a)-(c)-(e)-(f)-adhesive; dehesive-(a)- (c)-(e)-(g)-adhesive; (iv) dehesive-(a)-(b)-(c)-(d)-(e)-adhesive; dehesive-(a)-(b)-(c)-(d)-(f)-adhesive; dehesive-(a)-(b)-(c)- (d)-(g)-adhesive; dehesive-(a)-(b)-(c)-(e)-(f)-adhesive; dehesive-(a)-(b)-(c)-(e)-(g)-adhesive; dehesive-(a)-(c)-(d)-(e)-(f)-adhesive; dehesive-(a)-(c)-(d)-(e)-(g)-adhesive; dehesive-(a)-(c)-(e)-(f)-(g)-adhesive; (v) dehesive-(a)-(b)-(c)-(d)-(e)-(f)-adhesive; dehesive-(a)-(b)-(c)-(d)-(e)-(g)-adhesive; and (vi) dehesive-(a)-(b)-(c)-(d)-(e)-(f)-(g)-adhesive; where "dehesive" stands for a dehesive surface coating and "adhesive" stands for an adhesive surface coating.
102. The plastic film according to any one of claims 25 to 101, wherein the plastic film has a layer structure selected from (i) adhesive-(a)-(c)-dehesive; (ii) adhesive-(a)-(b)-(c)-dehesive; adhesive-(a)-(c)-(d)-dehesive; adhesive-(a)-(c)-(e)-dehesive; adhesive-(a)-(c)-(f)-dehesive; adhesive-(a)-(c)-(g)-dehesive; (iii) adhesive-(a)-(b)-(c)-(d)-dehesive; adhesive-(a)-(b)-(c)-(e)-dehesive; adhesive-(a)-(b)-(c)-(f)- dehesive; adhesive-(a)-(b)-(c)-(g)-dehesive; adhesive-(a)-(c)-(d)-(e)-dehesive; adhesive-(a)-(c)-(d)-(f)-dehesive; adhesive-(a)-(c)-(d)-(g)-dehesive; adhesive-(a)-(c)-(e)-(f)-dehesive; adhesive-(a)- (c)-(e)-(g)-releasable; (iv) adhesive-(a)-(b)-(c)-(d)-(e)-dehesive; adhesive-(a)-(b)-(c)-(d)-(f)-dehesive; adhesive-(a)-(b)-(c)- (d)-(g)-dehesive; adhesive-(a)-(b)-(c)-(e)-(f)-dehesive; adhesive-(a)-(b)-(c)-(e)-(g)-dehesive; adhesive-(a)-(c)-(d)-(e)-(f)-dehesive; adhesive-(a)-(c)-(d)-(e)-(g)-dehesive; adhesive-(a)-(c)-(e)-(f)-(g)-dehesive; (v) adhesive-(a)-(b)-(c)-(d)-(e)-(f)-dehesive; adhesive-(a)-(b)-(c)-(d)-(e)-(g)-dehesive; and (vi) adhesive-(a)-(b)-(c)-(d)-(e)-(f)-(g)-dehesive; where "dehesive" means a dehesive surface coating and "adhesive" means an adhesive surface coating.
103. The plastic film according to any one of claims 1 to 24, wherein the carrier film (A) optionally a layer (A) which contains or is based on non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide; (B) optionally an adhesion promoter layer (B); (C) optionally a layer (C) which contains or is based on non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide; (D) optionally an adhesion promoter layer (D); (E) optionally a layer (E) which contains or is based on non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide; (F) optionally an adhesion promoter layer (F); (G) optionally a layer (G) which contains or is based on non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide; (H) optionally comprises or consists of an adhesion promoter layer (H); wherein either the layer (A) or the adhesion promoter layer (B) forms the first outer layer of the carrier film.
104. The plastic film according to claim 103, wherein layer (A) and / or layer (C) and / or layer (E) and / or layer (G) each independently contain a mixture of non-water-soluble polymer, preferably polyolefin, polyester and / or polyamide, and water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH).
105. The plastic film of claim 104, wherein the non-water-soluble polymer is independently selected from the group consisting of polyolefins, polyesters and polyamides.
106. The plastic film according to claim 104 or 105, wherein the water-soluble polymer is selected from polymers or copolymers of vinyl acetate, vinylpyrrolidone, ethylene oxide, acrylamide, and lactic acid; preferably polymers or copolymers of vinyl acetate.
107. The plastic film according to claims 104 to 106, wherein the water-soluble polymer is independently selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polyvinyl alcohol (PVOH), polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyacrylamide (PAM), and polylactic acid (PLA); preferably butenediol-vinyl alcohol copolymer (BVOH).
108. The plastic film according to claim 104 to 106, wherein the water-soluble polymer has an ethylene group content of at most 10 mol%, more preferably at most 5.0 mol%, even more preferably at most 2.5 mol%, and in particular practically no ethylene groups at all.
109. The plastic film according to any one of claims 104 to 108, wherein the relative weight ratio of water-soluble polymer to non-water-soluble polymer is in the ratio of 10:1 to 1:10, preferably 8:1 to 1:8, more preferably 6:1 to 1:6, even more preferably 4:1 to 1:4, most preferably 3:1 to 1:3 and in particular 2:1 to 1:
2.
110. The plastic film according to any one of claims 103 to 109, wherein the layer (A) and / or the layer (C) and / or the layer (E) each independently has a layer thickness in the range of 0.5 to 100 pm, preferably 0.5 to 25 pm.
111. The plastic film according to any one of claims 103 to 110, wherein the layer (A) and / or the layer (C) and / or the layer (E) and / or the layer (G) each independently has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
112. The plastic film according to any one of claims 103 to 111, wherein the layer (A) and / or the layer (C) and / or the layer (E) and / or the layer (G) each independently has a layer thickness of at most 22 pm, more preferably at most 19 pm, even more preferably at most 16 pm, most preferably at most 13 pm and in particular at most 10 pm.
113. The plastic film according to any one of claims 103 to 112, wherein the adhesion promoter layer (B) and / or the adhesion promoter layer (D) and / or the adhesion promoter layer (F) and / or the adhesion promoter layer (H) each independently contains a mixture of non-water-soluble polymer and water-soluble polymer.
114. The plastic film of claim 113, wherein the non-water-soluble polymer is independently selected from anhydride-modified and acid-modified polyolefin.
115. The plastic film according to claim 113 or 114, wherein the water-soluble polymer is selected from polymers or copolymers of vinyl acetate, vinylpyrrolidone, ethylene oxide, acrylamide, and lactic acid; preferably polymers or copolymers of vinyl acetate.
116. The plastic film according to claims 113 to 115, wherein the water-soluble polymer is independently selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polyvinyl alcohol (PVOH), polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyacrylamide (PAM), and polylactic acid (PLA); preferably butenediol-vinyl alcohol copolymer (BVOH).
117. The plastic film according to claim 113 to 116, wherein the water-soluble polymer has an ethylene group content of at most 10 mol%, more preferably at most 5.0 mol%, even more preferably at most 2.5 mol%, and in particular practically no ethylene groups at all.
118. The plastic film according to any one of claims 113 to 117, wherein the relative weight ratio of water-soluble polymer to non-water-soluble polymer is in the ratio of 10:1 to 1:10, preferably 8:1 to 1:8, more preferably 6:1 to 1:6, even more preferably 4:1 to 1:4, most preferably 3:1 to 1:3 and in particular 2:1 to 1:
2.
119. The plastic film according to one of claims 113 to 118, wherein the adhesion promoter layer (B) and / or the adhesion promoter layer (D) and / or the adhesion promoter layer (F) and / or the adhesion promoter layer (H) each independently have a layer thickness in the range of 0.5 to 25 pm, preferably 0.5 to 10 pm.
120. The plastic film according to any one of claims 113 to 119, wherein the adhesion promoter layer (B) and / or the adhesion promoter layer (D) and / or the adhesion promoter layer (F) and / or the adhesion promoter layer (H) each independently has a layer thickness of at least 1.0 pm, more preferably at least 2.0 pm, even more preferably at least 3.0 pm, most preferably at least 4.0 pm and in particular at least 5.0 pm.
121. The plastic film according to any one of claims 113 to 120, wherein the adhesion promoter layer (B) and / or the adhesion promoter layer (D) and / or the adhesion promoter layer (F) and / or the adhesion promoter layer (H) each independently of one another has a layer thickness of at most 9.0 pm, more preferably at most 8.0 pm, even more preferably at most 7.0 pm, most preferably at most 6.0 pm and in particular at most 5.0 pm.
122. The plastic film according to any one of claims 103 to 121, wherein the first surface coating contains a mixture of polysiloxane and water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH).
123. The plastic film according to claim 122, wherein the polysiloxane is selected from the group consisting of addition-crosslinked, preferably metal-catalyzed addition-crosslinked, condensation-crosslinked, radically crosslinked, and / or cationically crosslinked polysiloxanes.
124. The plastic film according to claim 122 or 123, wherein the polysiloxane is selected from the group consisting of polydialkylsiloxanes, preferably polydimethylsiloxanes, and polyalkylarylsiloxanes, preferably polymethylphenylsiloxanes.
125. The plastic film according to any one of claims 122 to 124, wherein the water-soluble polymer is selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polyvinyl alcohol (PVOH), polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyacrylamide (PAM), and polylactic acid (PLA); preferably butenediol-vinyl alcohol copolymer (BVOH).
126. The plastic film according to any one of claims 122 to 126, wherein the relative weight ratio of water-soluble polymer to polysiloxane is in the ratio of 10:1 to 1:10, preferably 8:1 to 1:8, more preferably 6:1 to 1:6, even more preferably 4:1 to 1:4, most preferably 3:1 to 1:3 and in particular 2:1 to 1:
2.
127. The plastic film according to any one of the preceding claims, wherein the total content of water-soluble polymer contained in the plastic film, based on the total weight of the plastic film, is at least 0.5 wt.%, more preferably at least 1.0 wt.%, even more preferably at least 2.0 wt.%, most preferably at least 3.0 wt.% and in particular at least 4.0 wt.%.
128. The plastic film according to any one of the preceding claims, wherein the total content of water-soluble polymer contained in the plastic film, based on the total weight of the plastic film, is at most 18 wt.%, more preferably at most 16 wt.%, even more preferably at most 14 wt.%, most preferably at most 12 wt.% and in particular at most 10 wt.%.
129. The plastic film according to any one of the preceding claims, wherein the total content of water-soluble polymer contained in the plastic film, based on the total weight of the plastic film, is at most 10 wt.%, more preferably at most 9.0 wt.%, even more preferably at most 8.0 wt.%, most preferably at most 7.0 wt.% and in particular at most 6.0 wt.%.
130. The plastic film according to any one of the preceding claims, wherein the carrier film comprises at least one layer which contains or is based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH), and wherein the plastic film is cleavable along this layer upon treatment in a water bath, optionally at elevated temperature and after a sufficient exposure time.
131. The plastic film according to any one of the preceding claims, wherein the water-soluble polymer has a water solubility of at least 5.0 g / L; more preferably at least 10 g / L, even more preferably at least 15 g / L, most preferably at least 20 g / L, and especially at least 25 g / L.
132. The plastic film according to any one of the preceding claims, wherein the non-water-soluble polymer has a water solubility of at most 1000 mg / L, more preferably at most 500 mg / L, nor more preferably at most 100 mg / L, most preferably at most 50 mg / L, and in particular at most 10 mg / L.
133. A process for producing a plastic film according to any one of the preceding claims by blown film coextrusion.
134. The method of claim 133, wherein the extrusion of the plastic film occurs in one step.
135. A plastic film obtainable by a process according to claim 133 or 134.
136. Use of a plastic film according to one of claims 1 to 132 for recycling a part of its components, wherein preferably the plastic film is split after or during the treatment in a water bath, optionally at elevated temperature and after a sufficient exposure time, along at least one layer which contains or is based on water-soluble polymer, preferably butenediol-vinyl alcohol copolymer (BVOH) and / or polyvinyl alcohol (PVOH).