Packaging material

Abstract

The invention relates to a barrier paper comprising: a substrate which comprises or consists of fibrous material; and at least one coating film-formed directly or indirectly on at least one side of the substrate, wherein the coating is obtained by applying a polymer dispersion, comprising polyolefin and / or polyolefin copolymer particles, directly or indirectly to the substrate, and drying and film-forming the coating by applying heat, wherein the polyolefin and / or polyolefin copolymer particles have at least one particle size distribution with a span value of < 1.4, preferably < 1.0, particularly preferably < 0.6; and wherein the polyolefin and / or polyolefin copolymer particles meet at least one of the following criteria: a) a D90 value of < 3.0 µm, preferably < 2.5 µm, particularly preferably < 2.0 µm; b) a D50 value of < 1.5 µm, preferably < 1.0 µm, particularly preferably < 0.8 µm; c) a D10 value of < 0.8 µm, preferably < 0.7 µm, particularly preferably < 0.65 µm. The invention also relates to a method for producing such a packaging material, and to the use of the packaging material as packaging or as a component of packaging.

Description

[0001] Packaging material

[0002] Description

[0003] The present invention relates to a packaging material, a process for producing such a packaging material, a packaging material obtainable by this process and the use of the packaging material as packaging or as a component of packaging.

[0004] Packaging generally refers to the covering or (partial or complete) wrapping of an object, particularly for its protection or ease of handling. Consequently, packaging material includes the material that forms such a package.

[0005] Packaging materials can be based on paper, plastics, and / or metals, for example. The present invention essentially concerns packaging materials based on paper, cardboard, and paperboard.

[0006] The main requirements for packaging materials of any origin are to protect the packaged goods from external influences, to prevent leakage of the packaged goods, and to function as an advertising and information medium. To achieve this, the packaging material must meet different criteria depending on the packaged goods and the packaging process. Suitable packaging materials should not only possess barrier properties against, for example, water, grease, oxygen, or mineral oil, but also meet mechanical and process-specific requirements. Depending on the packaging system, a packaging material, especially a flexible packaging material, should possess sufficient tear resistance, an appropriate coefficient of friction, and flexibility. It should be heat-, cold-, or ultrasonically sealable, as well as externally printable, and should not lose its protective effect throughout the entire conversion and packaging process.

[0007] Known paper-based, coated packaging materials often contain compounds such as polyvinylidene chloride (containing halogens) or are composites of paper and metal or plastic films, have a tear resistance that needs to be improved, which can lead to running problems on packaging lines, and / or are often not recyclable due to an excessive coating content of adhesive components or the formation of so-called stickies via the paper fiber stream.

[0008] Recycled fibers, in particular, often contain polymer components, for example, from coatings used in paper production that have been inadequately removed. In order to reuse fibers recycled from the waste paper cycle in paper production, it is necessary that the fibers be as free as possible from disruptive components, as certain polymer components still adhering to the fibers can cause problems during reuse in the paper production process if they soften and clog parts of a paper machine, such as heated rollers.

[0009] The object of the present invention is to provide a packaging material which shows improved recyclability in the waste paper cycle and, in particular, in paper production, has a higher yield of recyclable and thus recyclable, non-process-impairing fiber components of the packaging material.

[0010] Furthermore, the packaging material should comprise at least one functional coating, e.g., a water vapor barrier layer, a grease barrier layer, and / or a heat-sealable layer, which is preferably applied in the form of a polymer dispersion to a substrate consisting of or comprising fiber materials. This object is achieved by a packaging material according to claim 1, ieby a packaging material comprising a substrate which comprises or consists of fibrous material and at least one coating which is directly or indirectly filmed on at least one side of the substrate, the coating being obtained by applying a polymer dispersion comprising polyolefin and / or polyolefin copolymer particles directly or indirectly to the substrate and drying and filming the particles by heat input, characterized in that the polyolefin and / or polyolefin copolymer particles have at least one particle size distribution with a span value of < 1.4, preferably < 1.0, particularly preferably < 0.6; and in that the polyolefin and / or polyolefin copolymer particles have at least one of the following criteria: a) a D. 90-value of < 3.0 pm, preferably < 2.5 pm, particularly preferably < 2.0 pm; b) a D5o value of < 1.5 pm, preferably < 1.0 pm, particularly preferably < 0.8 pm; c) a Dio value of < 0.8 pm, preferably < 0.7 pm, particularly preferably < 0.65 pm.

[0011] Preferably, these polyolefin and / or polyolefin copolymer particles have more than one of the criteria a) to c), particularly preferably all criteria a) to c).

[0012] Further preferred embodiments of the present invention are defined in the dependent claims.

[0013] The particle size distribution was determined using laser diffraction particle size analysis according to ISO 13320 (2009). The Fraunhofer model was used as the optical model for the evaluation. The measurement was carried out using ultrasonic treatment in deionized dilution water. To characterize the distribution width, the span value was determined. The span value is calculated according to (D 90- Dio) / D5o. The broader the distribution, the greater the standard deviation and the span value. For the determination of the span value ("width of size distribution"), reference is made to the appendix (p. 35) of ISO 13320 (2009). Within the scope of the invention, it was surprisingly found that a packaging material having the features according to claim 1 is very well recyclable in the waste paper cycle and, surprisingly, can also be produced much more economically, since less heat input is required for drying and filming the coating based on a polymer dispersion comprising particles that meet at least one criterion a) to d) than for drying a polymer dispersion comprising particles that do not have the features mentioned in claim 1. The drying and filming of the coating can take place at lower temperatures and / or for shorter times.The packaging material according to the invention is therefore more environmentally friendly than previous packaging materials in two respects: It is less energy-intensive to produce, and it is very easy to recycle. Surprisingly, it was also found that the packaging material according to the invention has a significantly better water vapor barrier than a comparable packaging material with a coating based on a polymer dispersion that otherwise comprises comparable particles, but which does not meet at least one of criteria a) to d).

[0014] In the context of the present invention, it was particularly surprisingly found that a chip value as small as possible of the particles in a polymer dispersion after film formation of the polymer particles in order to form a coating on a substrate can lead to particularly good recycling properties of the coated substrate.

[0015] Without being bound to a particular theory, it is assumed that particles that are as uniform and small as possible enable a particularly homogeneous application, so that during the subsequent drying and film formation of the polymer dispersion, a coherent layer is quickly formed on the substrate, which can be easily removed from the substrate during recycling.

[0016] If, however, the span value of the polyolefin and / or polyolefin copolymer particles is too high, the particles not only predominantly spread over the surface of the substrate, but can also sink into the substrate more heavily, which complicates the separation of the coating from the substrate fibers and thus negatively impacts the recycling properties. Furthermore, particles that penetrate the substrate contribute less to improving the barrier properties than those that are located on the surface of the substrate and thus in the film-formed coating.

[0017] A packaging material according to the invention is characterized in particular by the fact that fibers in the waste paper cycle under

[0018] can be better separated from packaging materials under standard processing conditions and thus lead to fewer problems in paper production using the separated fiber.

[0019] Furthermore, such a packaging material can be heat-, cold- or ultrasonically sealed if the corresponding functionality is present and ensures sufficiently low water vapor permeability to be used, for example, as packaging for moisture-sensitive foods.

[0020] Finally, the packaging material according to the invention can be produced relatively easily using various processes and with low application weights and can be recycled via the waste paper cycle.

[0021] Numerous specific details are also discussed below to provide a thorough understanding of the subject matter. However, it will be apparent to one skilled in the art that the subject matter can be practiced and recreated without these specific details.

[0022] All features of one embodiment may be combined with features of another embodiment if the features of the different embodiments are not incompatible.

[0023] The terminology used in the description of the present disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the subject matter. As used in this description and the claims, the singular forms "a," "an," and "the" are intended to include the plural forms, unless the context clearly dictates otherwise. The reverse is also true, meaning that the plural forms are intended to include the singular forms. It is also understood that the term "and / or," as used herein, refers to and includes all possible combinations of one or more of the related listed elements.It is further understood that the terms "includes," "including," "comprises," and / or "comprising," when used in the present description and claims, specify the presence of the stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0024] In the present description and claims, the terms "includes", "comprises" and / or "comprising" may also mean "consisting of", that is, the presence or addition of one or more other features, steps, operations, elements, components and / or groups is excluded.

[0025] In this description and the claims, the term "including" may therefore also mean "exclusively".

[0026] Unless otherwise stated, information in "%" in the context of formulations and / or compositions refers to "% by weight", in particular based on the respective total weight of the respective formulations and / or compositions.

[0027] As mentioned above, the packaging material according to the invention comprises a substrate and at least one coating filmed directly or indirectly on at least one side of the substrate. The coating is formed from a polymer dispersion containing polyolefin and / or polyolefin copolymer particles, wherein the polyolefin and / or polyolefin copolymer particles have at least one particle size distribution with a span value of

[0028] < 1.4, preferably <1.0, particularly preferably < 0.6; and wherein the polyolefin and / or polyolefin copolymer particles have at least one of the following criteria: a) a D 90-value of < 3.0 pm, preferably < 2.5 pm, particularly preferably < 2.0 pm; b) a D5o value of < 1.5 pm, preferably < 1.0 pm, particularly preferably < 0.8 pm; c) a Dio value of < 0.8 pm, preferably < 0.7 pm, particularly preferably < 0.65 pm. It has been shown that such coatings, which are directly or indirectly filmed onto the substrate and have the properties described above, facilitate the separation of the fibers from the packaging materials in the waste paper cycle under normal processing conditions.

[0029] If the coating is filmed directly onto the substrate, this means that there are no other coatings or substances between the substrate and the coating.

[0030] If the coating is indirectly filmed onto the substrate, this means that there are further coatings and / or substances between the substrate and the coating.

[0031] Laboratory tests have shown that it is possible to apply the coating directly to the substrate, especially when using calendered base paper with a surface thickness and a low Cobb value. For better hold-out of the coating and to minimize the required coating application, the prior application of a starch coating or primer is preferred. Ultimately, economic and production-technical considerations also determine which approach is preferred in each individual case.

[0032] In one embodiment, the packaging material according to the invention is preferably characterized in that the maximum particle size of the polyolefin and / or polyolefin copolymer particles is < 5 pm, preferably < 4 pm, particularly preferably 3 pm.

[0033] Furthermore, laboratory tests have shown that it is possible to draw conclusions about the recycling properties of the packaging material from the optical properties of the filmed coating. By adjusting the process parameters, in particular the heat supplied, during film formation of the coating on the substrate, the gloss can be adjusted, which in turn allows conclusions to be drawn about the separability of the coating from the fibers of the substrate. For the purposes of the present invention, gloss is understood to be the Lehmann gloss, which can be determined according to EN ISO 8254-1:2009. In one embodiment, the packaging material according to the invention is preferably characterized in that the filmed coating has a Lehmann gloss according to EN ISO 8254-1:2009 of > 10, preferably > 20, particularly preferably > 30 and in particular > 25.

[0034] It has been shown that insufficient film formation due to insufficient heat exposure, e.g. too low a temperature and / or too short a temperature exposure time, leads to lower gloss and a lower proportion of separable rejects or waste.

[0035] However, if film formation is carried out under excessive heat exposure, e.g., due to excessively high temperatures and / or excessively long exposure times, this can lead to a lower proportion of separable fiber components, also known as accepts. Accepts are the material that is not removed from the stock preparation process as rejects by the reject separation units. The accept percentage is determined from the relationship: Accept (yield) = (100 wt.% - reject in wt.%)

[0036] Therefore, depending on the choice of the substrate comprising or consisting of the fiber material and the coating applied directly or indirectly to at least one side of the substrate in the form of a polymer dispersion, it is preferred that the film formation is adjusted by the action of heat so that the gloss meets the above-mentioned criteria.

[0037] In addition, the inventors have derived two criteria from the relationship between the degree of film formation of the coating and the resulting proportion of separable reject and accept material that the packaging material should meet in order to ensure good recyclability.

[0038] In one embodiment, the packaging material according to the invention is preferably characterized in that at least 75% by weight, preferably at least 80% by weight, particularly preferably at least 90% by weight, of the filmed coating of the packaging material can be separated as reject according to Cepi Recyclability Test Method Version 2 (October 2022) and according to Paper and Board - Recyclability - Laboratory Test Method - PART I: Recycling Plant with Conventional Process. Cepi, Version 2, December 2022 and / or at least 75% by weight, preferably at least 80% by weight, particularly preferably at least 90% by weight of the fiber material of the substrate can be separated as accept material according to Cepi Recyclability Test Method Version 2.

[0039] In one embodiment, the packaging material according to the invention is preferably characterized in that not more than 50% by weight, preferably not more than 20% by weight, particularly preferably not more than 10% by weight, of the filmed coating of the packaging material according to Cepi Recyclability Test Method Version 2 (October 2022) and according to Paper and Board - Recyclability

[0040] - Laboratory test procedure - PART I: Recycling factory using conventional processes. CEPI, Version 2, December 2022. Dissolved colloidal substances (DCS) are separated.

[0041] According to CEPI Recyclability Test Method Version 2 (October 2022) and according to Paper and Board - Recyclability - Laboratory Test Method - PART I: Recycling Factory Using Conventional Process. CEPI, Version 2, December 2022, including the 4evergreen protocol for assessing the recyclability of fiber-based packaging. Version 1, January 2025, sheet stickiness can be determined and divided into different levels. Level 1 corresponds to no sheet stickiness, and Level 2 corresponds to a sheet stickiness that causes minor adhesion problems but may still be acceptable in the mix.

[0042] It has been shown in the context of the present application that packaging materials with a higher proportion of filmed coating and separated as reject have lower sheet stickiness.

[0043] In one embodiment, the packaging material according to the invention is preferably characterized in that the sheet stickiness of the accept of the fine screening has a sheet stickiness according to Cepi Recyclability Test Method Version 2 (October 2022) and according to Paper and Board

[0044] - Recyclability - Laboratory Test Method - PART I: Recycling Factory with Conventional Process. CEPI, Version 2, December 2022 including the 4evergreen Protocol for Assessing the Recyclability of Fiber-Based Packaging. Version 1, January 2025, Level 2 or better. The recycling properties of packaging materials are impaired by the presence of sticky contaminants, so-called "stickies." The origin of these sticky contaminants is diverse and can, for example, originate from the coating of the packaging material. In addition to sheet stickiness, the macrosticky measurement according to CEPI Recyclability Test Method Version 2 (October 2022) and according to Paper and Board - Recyclability - Laboratory Test Method - PART I: Recycling Factory with Conventional Process. CEPI, Version 2, December 2022 has been established as a measure of the recycling properties of packaging materials, where the area in mm 2of macrostickies per kg of sample is measured and essentially macrostickies with an area < 2000pm are considered.

[0045] In one embodiment, the packaging material according to the invention is preferably characterized in that the packaging material is less than 150,000 mm 2 / kg macrostickies < 2000 pm according to CEPI Recyclability Test Method Version 2 (October 2022) and according to Paper and Board - Recyclability - Laboratory Test Method - PART I: Recycling Plant with Conventional Process. CEPI, Version 2, December 2022.

[0046] The papers produced during CEPI, Version 2, December 2022, before and after sorting can also be analyzed using image analysis. The ImageJ program can be used for this purpose, following the procedures described below. The resulting values ​​for the average particle size of foreign matter in the newly formed paper (Average Size) depend not only on the degree of film formation but also on other factors, such as the pretreatment of the paper, etc. After sorting, i.e., the filtering of undesired components, in one embodiment of the packaging material according to the invention, this value drops significantly, to an average size of <40 pixels, preferably <30 pixels, particularly preferably <20 pixels. The percentage covered area (Area %) before sorting also depends on various factors, such as the application weight, etc. However, this also decreases significantly during the sorting process, to a value of <10%, preferably <5%, particularly preferably <1%.

[0047] The polymer dispersion applied directly or indirectly to the substrate is not limited in terms of the chemical composition of the polyolefin and / or polyolefin copolymer particles, as long as the required particle size distribution is met. However, some polymer dispersions have proven particularly effective.

[0048] Therefore, in one embodiment, the packaging material according to the invention is preferably characterized in that the polymer dispersion comprises a water-based polymer dispersion, preferably a water-based dispersion of an anionic polymer, and particularly preferably a water-based dispersion of an acid-modified anionic polymer, for example an acid-modified polyolefin copolymer, in particular a carboxylic acid- or sulfonic acid-modified polyolefin copolymer. Water-based polyolefins are described, for example, in WO 2021 / 225764 A1.

[0049] In another embodiment, the polymer dispersion comprises further components or additives.

[0050] In one embodiment, the packaging material according to the invention is preferably characterized in that the filmed coating comprises further coating components and auxiliaries, in particular for adjusting the rheology of the coating, preferably pigments, particularly preferably inorganic pigments, such as talc, kaolins, mica, bentonites and other natural or synthetic layered silicates or platelet-shaped precipitated calcium carbonate.

[0051] Such pigments are preferably present in the coating in an amount of 0 to 70 wt.%, based on the total weight of the coating. To avoid excessively impairing the heat-sealability of the polymer dispersion, amounts of 0 to 50 wt.%, better 0 to 30 wt.%, and most preferably 0 to 10 wt.%, should be selected. Preferably, the value of 0 wt.% is excluded as a lower limit.

[0052] Platelet-shaped pigments are preferably selected since, when aligned laminarly parallel to the coating, they can contribute to improving the barrier. The particle size should preferably be selected such that, when aligned laminarly, the particles are completely enclosed in the layer. The aspect ratio (ratio of average diameter to thickness, also called form factor) should be greater than 10, preferably greater than 100, and particularly preferably greater than 1000. The coating preferably comprises a polymeric binder based on a polyolefin or polyolefin copolymer and talc as a pigment, wherein the proportion of talc, based on the total weight of the dried coating, is preferably in the range from >0 to 50 wt.%, preferably 15 to 40 wt.%. The polyolefin is particularly preferably a polyethylene-based polyolefin (PE-based).

[0053] Other possible additives include, for example, thickeners, surfactants, crosslinkers and / or rheology modifiers, in particular acrylate-based compounds or carboxymethylcellulose (CMC) for rheology modification or to increase the extensibility of the polymer dispersion.

[0054] These additives are preferably present in an amount of 0 to 2 wt.%, preferably 0 to 1 wt.%, based on the total weight of the coating. Preferably, the value of 0 wt.% is excluded as a lower limit.

[0055] The roughness of the coating (according to Parker-Print-Surf (PPS) DIN ISO 8791-4, 2008-05) is <6.0 pm, preferably <5.0 pm, particularly preferably <2.0 pm.

[0056] The application quantity (ISO 536, 2020-05) of the coating is preferably 2 to 20 g / m 2 , preferably 2.5 to 15 g / m 2 and particularly preferably 3 to 12 g / m 2. The quantity refers to the dried, filmed coating in the final product.

[0057] In one embodiment, the packaging material according to the invention is preferably characterized in that the polyolefin and / or polyolefin copolymer has a DSC onset temperature between 70 and 80 °C, a DSC peak between 75 and 85 °C and / or a DSC endset temperature between 80 and 93 °C.

[0058] The onset temperature was determined using DSC as follows:

[0059] The onset temperature (according to DIN EN ISO 11357-1:2023-06) is the intersection point of the baseline and the inflection tangent at the beginning of the melting or crystallization peak in a DSC measurement. The baseline and the inflection tangent are determined from the temperature-dependent heat flow signal. For pure and homogeneous materials, the initial temperature can be specified as the melting temperature. In contrast to the peak temperature, the onset temperature is less dependent on the heating rate and sample mass. Furthermore, onset temperatures are commonly used for temperature calibration of a DSC.

[0060] Such a packaging material is particularly well-suited for packaging moisture-sensitive and water-containing objects, especially foodstuffs, and can be used for the production of pouches using hot-, cold-, or ultrasonic sealing applications. A water-based cold-seal adhesive can be used for the cold-seal application. Furthermore, barrier layers based on halogen-containing compounds are not required.

[0061] In one embodiment, the packaging material according to the invention is preferably characterized in that the polyolefin and / or polyolefin copolymer particle comprises a hydrophobic polyolefin and / or polyolefin copolymer, in particular a water vapor barrier-forming polyolefin and / or polyolefin copolymer.

[0062] In one embodiment, the packaging material according to the invention is preferably characterized in that the polyolefin and / or the polyolefin copolymer particles comprise non-functionalized ethylene-co-alkene copolymers, in particular ethylene-co-octene, ethylene-co-hexene, ethylene-co-butene copolymers or styrene-butadiene copolymer, wherein in particular the weight ratio of the structural units of ethylene to alkene is in the range from 99.8:0.2, preferably from 99.7:0.3, even more preferably from 99.6:0.4 to 50:50, even more preferably to 60:40 and most preferably to 65:35, and / or functionalized ethylene copolymer comprising the structural unit of a Ci-Ci2-alkyl acrylate or methacrylate.

[0063] As explained above, the film formation of the polymer dispersion can be adjusted by selecting the process parameters. Particularly with regard to the desired gloss and the recyclability of the packaging material, the heat exposure can be adjusted to achieve the desired properties.

[0064] Therefore, in one embodiment, the packaging material according to the invention is preferably characterized in that the polymer dispersion comprising polyolefin and / or polyolefin copolymer particles was filmed at a surface temperature of 75 to 100°C for a duration of more than 0.5 seconds, preferably more than 1 second. The filming can be determined from the gloss values, i.e. the temperature-time profile was selected such that the filmed coating has a Lehmann gloss according to EN ISO 8254-1:2009 of > 10, preferably > 20, particularly preferably > 30. As a rule, the time is longer at lower temperatures, e.g. gentle drying at a low temperature over a longer time, than at high temperatures, e.g. intensive drying at a higher temperature for a shorter time. A person skilled in the art can determine a temperature-time profile suitable for the respective coating using simple experiments.

[0065] The surface temperature is the temperature that the packaging material reaches during filming and can be adjusted depending on the web temperature and the duration of the heat application.

[0066] The packaging material according to the invention is further preferably characterized in that the coating comprises at least one wax.

[0067] The wax in the coating is preferably a wax according to the following definition of the German Society for Fat Research (DGF).

[0068] "Waxes are substances defined today by their mechanical and physical properties. Their chemical composition and origin, however, vary greatly. A substance is referred to as a wax if it is malleable at 20 °C, solid to brittle, has a coarse to fine-crystalline structure, is translucent to opaque in color but not glassy, ​​melts above 40 °C without decomposition, is slightly liquid (slightly viscous) slightly above its melting point, has a strongly temperature-dependent consistency and solubility, and is polishable under light pressure." If more than one of the properties listed above is not met, the substance is not considered a wax according to the German Society for Wax Research (DGF Standard Method MI 1 (75)). As our own laboratory studies have shown, the chemical composition of the waxes used does not play a decisive role.They should simply be selected so that they melt under the technically feasible drying conditions in the coating system. It has been shown that it is advantageous for the formation of the water vapor barrier if the melting temperature is below the boiling point of water (100°C), and even better, below 90°C.

[0069] As described above, the chemical composition of the polymer dispersion is not limited in principle, but encompasses all polyolefin and / or polyolefin copolymer particles that meet the required particle size distribution. However, if the polymer dispersion also contains waxes, it is also important to ensure that these are compatible with each other.

[0070] In principle, hydrophobic polymers can be used. However, polar polyolefin copolymer particles of synthetic or natural origin, or derivatives thereof, may also be suitable, provided the hydrophilic functional groups are shielded by any waxes present in the coating and the water vapor barrier does not impair the coating.

[0071] Laboratory tests have shown the following correlations: The lower the wax content, the better the heat sealability, especially the hot tack. However, a lower wax content results in higher water vapor permeability and a comparatively high sensitivity of the water vapor barrier to grease contact. If minimal wax is required, the aqueous coating should be dried in such a way that wax migrates to the surface, thus achieving a good, less grease-sensitive water vapor barrier.

[0072] In one embodiment, the wax is a wax according to DGF (DGF Standard Method MI 1 (75)) as defined above.

[0073] In one embodiment, the packaging material according to the invention is preferably characterized in that the coating comprises a wax, wherein the wax is selected from a wax based on mixtures or pure substances of fossil, animal or vegetable short to medium-chain hydrocarbons, their acids, esters, amides and / or diamides, waxes produced by hydrogenation or partial hydrogenation of vegetable oils, vegetable fats, animal oils and / or animal fats,

[0074] Metal soaps, preferably based on heneicosane, docosane, tricosane, tetracosane, pentacosane, hexacosane, heptacosane, octacosane, nonacosane, triacontane, hentriacontane, dotriacontane, tritriacontane, tetratriacontane, pentatriacontane, hexatriacontane, heptatriaontane, octatriacontane, nonatriacontane, montan wax, carnauba wax, beeswax, candelilla wax, rice bran wax, sugar cane wax, paraffin wax, in particular with an average molecular weight of at least 500 Dalton and a viscosity of at least 11 cSt at 100°C, wax obtained from sunflower seed presscake, wherein the wax is particularly preferably selected from wax comprising esters having a C15-C17-C(O)-O-C16-C18 structural unit (structural unit I), beeswax and / or

[0075] Wax obtained by at least partial hydrogenation of vegetable oils, in particular soybean oil.

[0076] In a further preferred embodiment, the wax of the coating consists of or comprises wax according to WO2024 / 121241 A1, in particular wax consisting of or comprising one or more esters, in particular selected from the list of linear monoesters of the following formula (1), linear diesters of the following formula (2), or linear diesters of the following formula (3), or mixtures thereof. In the following description, such a wax is also referred to as wax with a structural unit II.

[0077] Formula (1): RI-C(O)-O-R2, where Ri is a linear C3-C 23 -alkyl radical, preferably a linear Cn-Ci7-alkyl radical, and R2 is a linear C4-C24-alkyl radical, preferably a linear C12-C18-alkyl radical.

[0078] Formula (2): R3-C(O)-O-R4-OC(O)-R5, where R3 and R5 are independently a linear C3-C 23-Alkyl radical, preferably a linear Cn-Ci7-alkyl radical, R4 is a linear C4-C24-alkanediyl radical, preferably a linear C12-C18-alkanediyl radical. Formula (3): R6-OC(O)-R7-C(O)-O-R8, where R8 and R8, independently of one another, are a linear C4-C24-alkyl radical, preferably a linear C12-C18-alkyl radical, and R7 is a linear C2-C22-alkanediyl radical, preferably a linear C10- to C18-alkanediyl radical.

[0079] In a preferred embodiment, the wax of the coating comprises wax comprising esters having a Ci5-Ci7-C(O)-O-Ci6-Ci8 structural unit (structural unit I), wax having a structural unit II, wax obtained by at least partial hydrogenation of soybean oil, and / or paraffin wax.

[0080] Beeswax and / or paraffin wax are particularly preferred, as they are approved for direct food contact according to BfR XXVI of April 1, 2021, Chapter C, Section IV, Item 2, with reference to BfR XXV of June 1, 2019, Federal Institute for Risk Assessment of the Federal Ministry of Food and Agriculture, Germany.

[0081] When using paraffin waxes, those listed in FCM substance No. 94 of the EU Commission Regulation No. 10 / 2100 of 14 January 2011 "on plastic materials and articles intended to come into contact with food" are particularly preferred.

[0082] Further preferred is the use of an aqueous wax dispersion obtained by dispersing (A) a nonionic surfactant, (B) an anionic surfactant and (C) a wax in water and characterized in that the wax (C) contains an ester compound having a structural unit derived from a fatty acid and a structural unit derived from an aliphatic alcohol, wherein the content of the nonionic surfactant (A) is 40 to 99 parts by mass based on a total of 100 parts by mass of the nonionic surfactant (A), the anionic surfactant (B) and the wax (C), while it is 5 to 50 parts by mass based on a total of 100 parts by mass of the nonionic surfactant (A), the anionic surfactant (B), the wax (C) and water.

[0083] In one embodiment, the polymer dispersion comprises only the polyolefin and / or polyolefin copolymer particles and the wax, with certain weight ratios of the polyolefin and / or polyolefin copolymer particles to the wax being advantageous. In a preferred embodiment, the coating comprises a filmed polyolefin obtained by filming polyolefin particles, in particular as defined above, and wax comprising esters having a C15-C17-C(O)-O-C16-C18 structural unit (structural unit I), wax having a structural unit II, wax obtained by at least partial hydrogenation of soybean oil, and / or paraffin wax.

[0084] In one embodiment, the packaging material according to the invention is preferably characterized in that the weight ratio of polyolefin and / or polyolefin copolymer to the wax in the (filmed) coating is from 70:30 to 99.5:0.5, preferably from 80:20 to 99:1, particularly preferably from 85:15 to 98:2, in particular 90:10.

[0085] In a preferred embodiment, a layer comprising starch (starch layer) and / or modifications thereof (modified starches) may be present directly on at least one side of the substrate, preferably directly on both sides of the substrate of the packaging material according to the invention.

[0086] The starch coating is preferably used in an amount of 0.1 to 3, particularly preferably 0.2 to 1.5 g / m 2 , applied.

[0087] A starch coating on the side of the substrate where the coating is present has the advantage of sealing the substrate, thus improving the adhesion of the coating and reducing or preventing penetration of the coating into the substrate.

[0088] The starch coating preferably has a Bekk smoothness of greater than 20 s, more preferably greater than 50 s and most preferably from 50 to 200 s.

[0089] Furthermore, for example, the uncoated side of the substrate can be provided with one or more other coatings that are more printable than the surface of the base paper provided with only a starch coating. In one embodiment, the packaging material according to the invention is preferably characterized in that a primer is applied directly to at least one side of the substrate, preferably directly to both sides of the substrate.

[0090] Preferably, a starch coat, as defined above, and a precoat, in particular as defined below, are present in this order between the substrate and the coating.

[0091] Preferably, such a pre-coat, also referred to as a primer, comprises or consists of at least one inorganic pigment and a polymeric binder.

[0092] The inorganic pigment is preferably platelet-shaped and comprises in particular a talc, precipitated calcium carbonate or silicate, preferably a layered silicate and most preferably a kaolin.

[0093] The aspect ratio of the platelet-shaped pigment (ratio of average diameter to thickness, also called aspect factor) should be about 7 to 40 to 1, preferably about 15 to 30 to 1.

[0094] The particle size of the platelet-shaped pigment is preferably adjusted so that at least about 70%, preferably at least about 85%, of the particles have a particle size of about <2 μm (Sedigraph). The pH of the platelet-shaped pigment in aqueous solution is preferably 6 to 8.

[0095] Suitable polymeric binders include, in particular, acrylate-based or styrene / butadiene-based binders. In principle, all polymers that can be used as binders for pigment coatings in the paper industry are suitable. Carbohydrate-based binders, particularly starch-based binders (solutions of modified starches, dispersions of cross-linked starches, so-called biolatices) and polymer-starch hybrid latices, as well as protein-based binders such as casein, are also possible.

[0096] The polymeric binder preferably comprises a polymeric binder based on a polyacrylate. The polymeric binder preferably comprises a styrene-acrylate copolymer, preferably a styrene-butyl acrylate copolymer, in particular a styrene-n-butyl acrylate copolymer.

[0097] A suitable styrene-n-butyl acrylate copolymer is known, for example, under the trade name Acronal S 305 FD.

[0098] The primer can be hydrophobic overall.

[0099] In another embodiment, the primer is entirely hydrophilic.

[0100] The primer preferably contains 5 to 50 wt.%, more preferably 10 to 30 wt.%, of polymeric binder. This amount refers to the dried primer in the final product.

[0101] The primer preferably further contains 50 to 95% by weight, more preferably 65 to 85% by weight, of inorganic pigment. This amount refers to the dried primer in the final product.

[0102] The primer can also contain additives such as thickeners, e.g., acrylate-based thickeners, surfactants, and / or rheology modifiers. The use of crosslinking agents is also conceivable. The primer preferably contains an ammonium zirconium carbonate crosslinking agent and is itself crosslinked with formaldehyde.

[0103] These additives are preferably present in an amount of 0 to 2 wt.%, preferably greater than 0 to 2 wt.%, with the value 0 wt.% preferably being excluded. This amount refers to the dried primer in the final product.

[0104] The application quantity (ISO 436, 2020-05) of the primer is preferably 1 to 20 g / m 2 and particularly preferably 2 to 12 g / m 2. The quantity refers to the dried primer in the final product.

[0105] Applying such a primer has the advantage that the substrate surface is sealed and the subsequent coating film formed on top only migrates slightly into the paper. Furthermore, the primer reduces the average surface roughness of the substrate and offers a favorable coating holdout, characterized by a comprehensive application and a defined surface energy, so that the applied polymer dispersion can be optimally filmed into the coating and can form an optimal barrier with as little application as possible, which has a beneficial effect on the cost structure. Furthermore, the primer is designed in such a way that the layer adhesion between the substrate and the coating is not significantly reduced, which can be important for subsequent sealing applications. This also applies if there is a starch layer between the primer and the substrate.

[0106] The surface tension (alternatively also called surface energy) of the primer is preferably 15 to 40 mN / m, in particular 22 to 30 mN / m.

[0107] The surface tension is determined according to DIN EN ISO 19403-2:2020-04:

[0108] For good wetting and layer adhesion, the surface tension of the primer should be higher or at least more polar than that of the layer on top.

[0109] If necessary, it is important to ensure that the surface tension of the coating and the primer are matched. A highly polar primer would swell excessively when coated with an aqueous coating formulation, which could lead to cracking after drying. Therefore, the specified data on the surface tension of the primer have proven particularly useful.

[0110] The smoothness of the primer (according to Bekk (ISO 5627, 1995-03)) is preferably 80 to 200 s, preferably 90 to 120 s.

[0111] The roughness of the precoat (according to Parker-Print-Surf (PPS) DIN ISO 8791-4, 2008-05) is preferably 2.8 to 4.0 pm, preferably 3.2 to 3.6 pm.

[0112] In one embodiment, the packaging material according to the invention can comprise, in addition to the above-described primer and coating, further layers, such as sealing coatings such as cold-seal adhesives or additional hot-seal adhesives, metallizations, and / or additional barrier layers (water vapor barriers, oxygen barriers, mineral oil barriers, oil and grease barriers, aroma barriers). These layers can be applied directly or indirectly to at least one side of the substrate, but also between the individual layers of the packaging material.

[0113] In one embodiment, the packaging material according to the invention is preferably characterized in that the packaging material comprises at least one further coating.

[0114] To improve the overall barrier properties of a packaging material, smooth surfaces can be coated with metals or metal oxides (e.g. via vacuum vapor deposition).

[0115] The prerequisite for this is preferably smooth surfaces or a smooth print line on the uncoated side of the substrate.

[0116] Barrier coatings are also known, which a processor can apply over the entire surface or only to specific areas.

[0117] One example would be the HYDRO-LAC GA oxygen barrier varnish from Hubergroup Print Solutions. This varnish can be applied to the coating or to the uncoated side of the substrate, or even better, to a smooth print line.

[0118] The packaging material can be heat sealed, but it is still possible to apply cold seal adhesive to one of the two sides of the packaging material, especially if the packaging material is to be used on a packaging machine designed for cold seal bonding.

[0119] Preferably, one of the two sides, preferably the print side, can be provided with an additional heat-sealing adhesive with the aim of sealing between the front and back (A / B sealing).

[0120] Such a packaging material is in particular heat-, cold- or ultrasonically sealable or knurlable (e.g. closure of a package comprising a packaging material according to the invention by means of knurling in a packaging machine) and ensures sufficient sealability to be used, for example, as packaging for moisture-sensitive and fatty foods.

[0121] In one embodiment, the packaging material comprises a primer and a coating as defined above.

[0122] The primer described above can be applied in one, two or more layers.

[0123] In a preferred embodiment, the packaging material comprises a starch-coated substrate, a precoat and a coating as defined above.

[0124] The substrate used in the packaging material according to the invention is in principle not limited.

[0125] In one embodiment, the packaging material according to the invention is preferably characterized in that the substrate comprises a paper, a cardboard or a paperboard, preferably a paper with a basis weight of 20 to 120 g / m 2 , preferably from 50 to 100 g / m 2 , has.

[0126] Furthermore, it is preferred that the substrate comprises long and short fibers, wherein a long fiber is a fiber with a fiber length of 2.6 to 4.4 mm and a short fiber is a fiber with a fiber length of 0.7 to 2.2 mm, and the long fiber content is preferably from 10 to 80 wt.%, preferably from 20 to 60 wt.%, and the short fiber content is preferably from 20 to 90 wt.%, preferably from 50 to 70 wt.%.

[0127] The long fiber content in particular ensures the strength of the comparatively thin paper, while the short fiber content makes the paper denser and more cohesive, giving it a uniform appearance. A further increase in the long fiber content would make the paper too stiff. The lower price of short fiber pulp compared to long fiber pulp plays a further role. In addition, the substrate can contain 0 wt.% to 20 wt.%, preferably 0 wt.% to 5 wt.%, of fillers, with the value 0 wt.% preferably being excluded, such as GCC (ground calcium carbonate), known for example under the trade name Hydrocarb 60 or Hydroplex 60, PCC (precipitated calcium carbonate), known for example under the trade name Precarb 105, natural kaolin and / or talc.

[0128] Furthermore, common auxiliary substances such as retention aids and / or sizing agents may be contained in the substrate.

[0129] Particularly for food contact, the substrate comprises at least 60 wt.%, preferably at least 75 wt.% fiber, at most 25 wt.%, preferably at most 10 wt.% fillers, and at most 15 wt.% excipients. In addition, unavoidable or necessary traces of processing aids (e.g., reagents, dispersants, anti-mold agents, etc.) may be present in the substrate.

[0130] The advantage of such a substrate is, on the one hand, its high flexibility and, on the other hand, its good processability on existing packaging lines for flexible materials, such as plastic films, maintaining high machine availability and achieving the necessary puncture resistance.

[0131] The packaging material according to the invention can be obtained economically using all known paper production and coating processes (film press with or without pre-dosing, roller application, doctor blade, blade, curtain coater, spray coater).

[0132] However, it is preferred to obtain the packaging material according to the invention by a process in which a polymer dispersion comprising polyolefin and / or polyolefin copolymer particles is applied directly or indirectly to at least one side of the substrate, the application suspension having a solids content of 20 to 60% by weight, preferably 30 to 50% by weight, and is applied by a curtain coating process at an operating speed of the coating system of at least 300 m / min and is then filmed by heat input in order to contain a coating, the filming preferably taking place by means of IR drying and / or hot air drying.In one embodiment of the process according to the invention, the polymer dispersion comprising polyolefin and / or polyolefin copolymer particles is filmed at a surface temperature of 75 to 100 °C, preferably for a duration of more than 0.5 seconds, preferably more than 1 second.

[0133] Contactless processes such as IR drying and / or hot air drying, whose heat input can be individually adjusted, have proven effective for filming the coating suspension. This process is particularly advantageous from an economic perspective and due to the uniform application over the substrate, preferably the paper web.

[0134] If the solids content falls below approximately 20 wt.%, the cost-effectiveness deteriorates, as a large amount of water must be removed in a short time through gentle drying, which adversely affects the coating speed. On the other hand, if the value exceeds 60 wt.%, this simply leads to increased technical effort to ensure the stability of the coating suspension curtain during the coating process and the drying of the applied film, as the machine must again run at very high speeds.

[0135] In the curtain coating process, a freely falling curtain of a coating suspension is formed. The coating suspension, in the form of a thin film (curtain), is "poured" onto the substrate by free fall to apply the coating suspension to the substrate. DE 10 196 052 TI discloses the use of the curtain coating process in the production of information recording materials, whereby multilayer recording layers are realized by applying the curtain consisting of several coating dispersion films to substrates.

[0136] In a preferred embodiment of the process according to the invention, the aqueous deaerated coating suspension has a viscosity of approximately 100 to approximately 400 mPas (Brookfield, 100 rpm, 20 °C). If the viscosity falls below approximately 80 mPas or exceeds approximately 500 mPas, this leads to poor runnability of the coating slip on the coating unit. The viscosity of the aqueous deaerated coating suspension is particularly preferably approximately 150 to approximately 300 mPas.

[0137] In a preferred embodiment, to optimize the process, the dynamic surface tension of the aqueous polymer dispersion can be adjusted to about 35 to about 55 mN / m, preferably to about 38 to about 52 mN / m (measured 50 ms after bubble formation) in accordance with the standard for bubble pressure tensiometry (ASTM D 3825-90), as described below. Better control over the coating process is obtained if the dynamic surface tension of the polymer dispersion is determined and specifically adjusted by selecting the appropriate surfactant and by determining the required amount of surfactant.

[0138] For development purposes and for the production of prototypes, the paper can also be produced on a laboratory scale by hand-coating and subsequent drying in a drying cabinet. Drying can be carried out, for example, analogously to the previously described temperature treatment for 3 minutes at 90°C in a drying cabinet. Since the risk of bubble formation is lower with this slow drying process, a temperature of greater than 100°C, preferably 105°C, can also be set.

[0139] In further embodiments, the polymer dispersion can also be applied to the substrate by the following methods:

[0140] The polymer dispersion can be applied to the substrate using printing processes (e.g. flexographic printing and gravure printing).

[0141] The present invention further relates to a packaging material which is obtainable by the processes described above.

[0142] In an alternative embodiment, the packaging material according to the invention is produced in particular by a process comprising the following steps:

[0143] - Providing a substrate, in particular a paper substrate;

[0144] - applying a polymer dispersion comprising polyolefin and / or polyolefin copolymer particles to at least one side of the substrate directly or indirectly, wherein the particles have at least one of the following criteria:

[0145] - Providing a substrate, in particular a paper substrate;

[0146] - applying a polymer dispersion comprising polyolefin and / or polyolefin copolymer particles to at least one side of the substrate directly or indirectly, characterized in that the polyolefin and / or polyolefin copolymer particles have at least one particle size distribution with a span value of < 1.4, preferably < 1.0, particularly preferably < 0.6; and that the polyolefin and / or polyolefin copolymer particles have at least one of the following criteria: a) a D 90 -value of < 3.0 pm, preferably < 2.5 pm, particularly preferably < 2.0 pm; b) a D5o value of < 1.5 pm, preferably < 1.0 pm, particularly preferably < 0.8 pm; c) a Dio value of < 0.8 pm, preferably < 0.7 pm, particularly preferably < 0.65 pm; d) the difference between the onset temperature and the endset temperature of the particles measured by DSC is not more than 20 °C, preferably not more than 15 °C;

[0147] - Drying and filming of the polymer dispersion by heat input while maintaining the coating.

[0148] In a preferred embodiment of the alternative process, the drying and filming of the polymer dispersion is carried out by heat input such that the surface temperature of the coating is not more than 30 °C, preferably not more than 20 °C, above the DSC melting point of the particles for not more than 60 seconds, more preferably for not more than 30 seconds, most preferably for not more than 10 seconds and in particular for not more than 1 second, with 0 seconds being very preferred.

[0149] The DSC melting point is determined according to DIN EN ISO 11357-1:2023-06 (peak maximum of the DSC measurement). In further embodiments of the method described above, the polymer dispersion comprises a water-based polymer dispersion.

[0150] The present invention further relates to a packaging material obtainable by the alternative processes described above or alternative embodiments thereof.

[0151] Finally, the present invention also relates to the use of a packaging material as described above as packaging material or as a component of packaging material, in particular heat-, cold- or ultrasonically sealable packaging, preferably for foodstuffs, cosmetics, hygiene articles, tobacco, in particular for packaging moisture-sensitive foodstuffs and / or fatty foodstuffs and for protecting them from atmospheric humidity or fats from the environment.

[0152] The packaging material according to the invention can be used on all common packaging systems. Examples include vertical and horizontal form-fill-seal machines for producing, among other things, stand-up pouches, flow packs, or pillow packs; air cushion bags or pillows as a replacement for plastic air cushion bags or pillows; and machines that combine two webs of the same or different materials and join them by heat sealing, e.g., tray sealers, chamber belt machines (also with vacuum), bag filling and closing machines, thermoforming packaging machines, linear filling machines that apply lids by heat sealing, wrapping machines with a final heat sealing step, blister packaging machines, and X-fold packaging machines.

[0153] The invention is explained in detail below using non-limiting examples. Examples

[0154] For Examples 1 to 10 and Comparative Examples 1 to 3, paper from a production line was used as the substrate.

[0155] The pure base paper was produced on the associated paper machine (40 wt.% long fiber, 60 wt.% short fiber), smoothed by means of a calender and cationically modified potato starch (approx. 1 g / m 2 ) was applied. The basis weight of the base paper was 60 g / m 2 according to ISO 536 (2020).

[0156] The paper machine is equipped with a Yankee cylinder and is therefore able to produce paper that is smooth on one side.

[0157] In the second step, the respective amount of polymer dispersion was applied to each paper. The respective compositions can be found in Table 1.

[0158] The drying unit consists of a series of electric infrared dryers followed by a block of air hoods (hot air drying).

[0159] After applying the polymer dispersions to these paper substrates in a coating machine, the coated paper substrates were dried using the following drying parameters: maximum air temperature in the drying unit 160 °C (controlled by measuring the maximum surface temperature of the coated paper substrate); maximum surface temperature of the coated paper substrate 80 °C; drying time 1.46 seconds.

[0160] The coated paper was then dried and filmed in a drying cabinet (hot-air oven) according to the specifications in Table 1. The final drying is preferably carried out in a hot-air oven, whereby care must be taken to ensure that the paper is actually exposed to the respective temperature for the respective period. For this purpose, the oven must be preheated and have a sufficient internal volume (> 100 dm 3, e.g. width x height x depth 60 cm x 48 cm x 37 cm) so that when the front door is opened briefly (2-3 s) to put the paper in, there is no significant drop in temperature. The paper is placed on a metal grid located in the middle of the oven, preferably with a cardboard box on top. The metal grid and cardboard box must have already reached the oven temperature and have been placed in the oven, which has already been preheated to the required temperature, for at least 15 minutes before the start of the temperature treatment. The convection oven is located in an air-conditioned room with a temperature of 23°C and 50% humidity, so that the paper was at a temperature of 23°C before it was placed in the oven.

[0161] To determine the recycling properties and gloss, the hot-air oven temperature and dwell time were varied. The respective temperatures and times for post-filming are shown in Table 1.

[0162] The main components of the respective coating, the drying parameters and the determined properties of the packaging materials are summarized in the following Table 1.

[0163] Lehmann gloss was determined by photometric measurements using a converging beam at 75°C according to EN ISO 8254-1:2009. The measurements were tested on coatings with different film formations, varying the surface temperature and exposure time. The respective process parameters can be found in Table 1.

[0164] The particle size distribution of the polyolefin and / or polyolefin copolymer particles was determined using laser diffraction particle size analysis. The calculation of mean values ​​of the particle size distribution is described in ISO 9276-2 (2018). To characterize the distribution width, the span value (span) was determined. The span value is calculated according to (D 90 - Dio) / D5o calculated.

[0165] To evaluate the recycling properties, the acceptability and reject rates were determined. For this purpose, the produced packaging materials were tested according to CEPI Recyclability Laboratory Test Method Version 2 (October 2022) and according to Paper and Board - Recyclability - Laboratory Test Method - PART I: Recycling Factory Using Conventional Process. CEPI, Version 2, December 2022, including the 4evergreen Protocol for Assessing the Recyclability of Fiber-Based Packaging. Version 1, January 2025. For image analysis using ImageJ (freeware software), a laboratory sheet was scanned at a resolution of 600 dpi and converted into a black and white image (8-bit representation, see example Fig. 1-4). Subsequently, the image was center-cropped to an image size of 3000 x 3500 pixels (see example Fig. 5-8) and converted into a binary image (see example Fig. 9-12).

[0166] Rejects / particles are displayed in white, while the surrounding lab sheet is displayed in black. This enables particle detection, i.e., image-analytical identification of rejects / particles and their counting in pixels (see example Fig. 13-16). The particle analysis program uses settings that account for particles of all shapes and sizes (Size: 0 - Infinity and Circularity: 0.00 - 1.00).

[0167] The program outputs two parameters, among others: % Area, which represents the percentage area of ​​rejects / particles in the image, and Average Size, which represents the average particle size in pixels.

[0168] The results of the analysis are summarized in Figure 1.

[0169] Part 1: Examples

[0170]

[0171]

[0172]

[0173]

[0174] No remake

[0175] 2) Theoretical coating proportion: [Coating weight of polymer dispersion including coating additives / (base paper basis weight + coating weight of polymer dispersion including coating additives)]

[0176] 3) Theoretically removed coating fraction: [Reject / Theoretical coating fraction]

[0177]

[0178]

[0179]

[0180]

[0181]

[0182]

[0183]

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Claims

Claims 1. Packaging material, comprising a substrate which comprises or consists of fibrous material, and at least one coating filmed directly or indirectly on at least one side of the substrate, wherein the coating is obtained by applying a polymer dispersion comprising polyolefin and / or polyolefin copolymer particles directly or indirectly to the substrate and drying and filming them by heat input, characterized in that the polyolefin and / or polyolefin copolymer particles have at least one particle size distribution with a span value of < 1.4, preferably < 1.0, particularly preferably < 0.6; and in that the polyolefin and / or polyolefin copolymer particles have at least one of the following criteria: a) a D 90-value of < 3.0 pm, preferably < 2.5 pm, particularly preferably < 2.0 pm; b) a D5o value of < 1.5 pm, preferably < 1.0 pm, particularly preferably < 0.8 pm; c) a Dio value of < 0.8 pm, preferably < 0.7 pm, particularly preferably < 0.65 pm.

2. Packaging material according to claim 1, characterized in that the maximum particle size of the polyolefin and / or polyolefin copolymer particles is < 5 pm, preferably < 4 pm, particularly preferably 3 pm.

3. Packaging material according to claim 1 or 2, characterized in that the filmed coating has a Lehmann gloss according to EN ISO 8254-1:2009 of >10, preferably >20, particularly preferably >25.

4. Packaging material according to any one of the preceding claims, characterized in that at least 75% by weight, preferably at least 90% by weight, of the filmed coating of the packaging material is separable as reject according to Cepi Recyclability Test Method Version 2 (October 2022) and / or according to Paper and Board - Recyclability - Laboratory Test Method - PART I: Recycling Plant with Conventional Process. Cepi, Version 2, December 2022, and / or at least 75% by weight, particularly preferably at least 90% by weight, of the fiber of the substrate is separable as accept according to Cepi Recyclability Test Method Version 2 (October 2022) and / or according to Paper and Board - Recyclability - Laboratory Test Method - PART I: Recycling Plant with Conventional Process. Cepi, Version 2, December 2022.

5. Packaging material according to any of the preceding claims, characterized in that the packaging material has a sheet stickiness of Level 2 or better according to CEPI Recyclability Test Method Version 2 (October 2022) and / or according to Paper and Board - Recyclability - Laboratory Test Method - PART I: Recycling Factory with Conventional Process. CEPI, Version 2, December 2022, including the 4evergreen Protocol for Assessing the Recyclability of Fiber-Based Packaging. Version 1, January 2025.

6. Packaging material according to any one of the preceding claims, characterized in that the packaging material has less than 150,000, preferably less than 50,000 mm 2 / kg macrostickies <2000 pm according to CEPI Recyclability Test Method Version 2 (October 2022) and / or according to Paper and Board - Recyclability - Laboratory Test Method - PART I: Recycling Plant with Conventional Process. CEPI, Version 2, December 2022.

7. Packaging material according to any one of the preceding claims, characterized in that not more than 50 wt.%, preferably not more than 20 wt.%, particularly preferably not more than 10 wt.%, of the filmed coating of the packaging material according to Cepi Recyclability Test Method Version 2 (October 2022) and / or according to Paper and Board - Recyclability - Laboratory Test Method - PART I: Recycling Factory with Conventional Process. Cepi, Version 2, December 2022 as dissolved colloidal components.

8. Packaging material according to any one of the preceding claims, characterized in that the polymer dispersion comprises a water-based polymer dispersion, preferably a water-based dispersion of an anionic polymer, and more preferably a water-based dispersion of an anionic acid-modified polymer.

9. Packaging material according to any one of the preceding claims, characterized in that the filmed coating comprises further coating components and auxiliaries, in particular for adjusting the rheology of the coating, preferably pigments, particularly preferably inorganic pigments, layered silicates, talc, kaolins, or platelet-shaped precipitated calcium carbonate.

10. Packaging material according to any one of the preceding claims, characterized in that the polyolefin and / or polyolefin copolymer particle has a DSC onset temperature between 70 and 80 °C, a DSC peak between 75 and 85 °C and / or a DSC endset temperature between 80 and 93 °C.

11. Packaging material according to any one of the preceding claims, characterized in that the polyolefin and / or polyolefin copolymer particle comprises a hydrophobic polyolefin and / or polyolefin copolymer, in particular a water vapor barrier-forming polyolefin and / or polyolefin copolymer.

12. Packaging material according to any one of the preceding claims, characterized in that the polyolefin and / or the polyolefin copolymer particles are non-functionalized ethylene-co-alkene copolymers, in particular ethylene-co-octene, ethylene-co-hexene, ethylene-co-butene copolymers, wherein in particular the weight ratio of the structural units of ethylene to alkene is in the range from 99.8:0.2, preferably from 99.7:0.3, more preferably from 99.6:0.4 to 50:50, even more preferably to 60:40 and most preferably to 65:35, and / or functionalized ethylene copolymer comprising the structural unit of a Ci-Ci2 alkyl acrylate or methacrylate.

13. Packaging material according to any one of the preceding claims, characterized in that the polymer dispersion comprising polyolefin and / or polyolefin copolymer particles was filmed at a surface temperature of 65 to 110 °C, preferably 75 to 100 °C, for a duration of more than 0.5 seconds, preferably for a duration of more than 1 second.

14. Packaging material according to any one of the preceding claims, characterized in that the coating comprises a wax, in particular wherein the wax is selected from a wax based on mixtures or pure substances of fossil, animal or vegetable short to medium-chain hydrocarbons, their acids, esters, amides and / or diamides, waxes produced by hydrogenation or partial hydrogenation of vegetable oils, vegetable fats, animal oils and / or animal fats, metal soaps, preferably based on heneicosane, docosane, tricosane, tetracosane, pentacosane, hexacosane, heptacosane, octacosane, nonacosane, triacontane, hentriacontane, dotriacontane, tritriacontane, tetratriacontane, pentatriacontane, hexatriacontane, heptatriacontane, octatriacontane, nonatriacontane, montan wax, carnauba wax, beeswax, candelilla wax, rice bran wax, Sugar cane wax, paraffin wax,in particular with an average molecular weight of at least 500 Dalton and a viscosity of at least 11 cSt at 100°C, wax obtained from sunflower seed presscake, wherein the wax is particularly preferably selected from wax comprising esters having a Ci5-Ci7-C(O)-O-Ci6-Ci8 structural unit (structural unit I), wax having a structural unit II, beeswax and / or, Wax obtained by at least partial hydrogenation of vegetable oils, in particular soybean oil.

15. Packaging material according to claim 13, characterized in that the weight ratio of polyolefin and / or polyolefin copolymer to the wax in the coating is from 70:30 to 99.5:0.5, preferably from 80:20 to 99:1, particularly preferably from 85:15 to 98:

2.

16. Packaging material according to any one of the preceding claims, characterized in that the packaging material comprises at least one further coating.

17. Packaging material according to any one of the preceding claims, characterized in that a primer is applied directly to at least one side of the substrate, preferably directly to both sides of the substrate.

18. Packaging material according to any one of the preceding claims, characterized in that the substrate comprises a paper, a cardboard or a paperboard, preferably a paper with a basis weight of 20 to 120 g / m 2 , preferably from 25 to 100 g / m 2 , has.

19. A process for producing a packaging material according to any one of claims 1 to 18, characterized in that a polymer dispersion comprising polyolefin and / or polyolefin copolymer particles is applied directly or indirectly to at least one side of the substrate, the application suspension having a solids content of 20 to 60% by weight, preferably 30 to 50% by weight, and is applied using a curtain coating process at an operating speed of the coating system of at least 300 m / min and is then filmed by heat input in order to contain a coating, the filming preferably taking place by means of IR drying and / or hot air drying.

20. Packaging material obtainable by the process according to claim 19.

21. A method for producing a packaging material, in particular according to one of claims 1 to 18, comprising the following steps: - Providing a substrate, in particular a paper substrate; - applying a polymer dispersion comprising polyolefin and / or polyolefin copolymer particles to at least one side of the substrate directly or indirectly, characterized in that the polyolefin and / or polyolefin copolymer particles have at least one particle size distribution with a span value of < 1.4, preferably < 1.0, particularly preferably < 0.6; and that the polyolefin and / or polyolefin copolymer particles have at least one of the following criteria: a) a D 90 -value of < 3.0 pm, preferably < 2.5 pm, particularly preferably < 2.0 pm; b) a D5o value of < 1.5 pm, preferably < 1.0 pm, particularly preferably < 0.8 pm; c) a Dio value of < 0.8 pm, preferably < 0.7 pm, particularly preferably < 0.65 pm; d) the difference between the onset temperature and the endset temperature of the particles measured by DSC is not more than 20 °C, preferably not more than 15 °C; - Drying and filming of the polymer dispersion by heat input while maintaining the coating.

22. The method according to claim 21, wherein the drying and filming of the polymer dispersion is carried out by heat input such that the surface temperature of the coating is not more than 30 °C, preferably not more than 20 °C, above the DSC melting point of the particles for not more than 60 seconds, more preferably for not more than 30 seconds, most preferably for not more than 10 seconds and in particular for not more than 1 second, with 0 seconds being very preferred.

23. The method according to claim 21 or claim 22, wherein the polymer dispersion comprises a water-based polymer dispersion.

24. Use of a packaging material according to any one of claims 1 to 18 or claim 20 as packaging or as a component of packaging, in particular heat-, cold-, or ultrasonically sealable packaging, preferably for foodstuffs, cosmetics, hygiene articles, tobacco, in particular for packaging moisture-sensitive foods and / or fatty foods and for protecting them from atmospheric humidity or ambient fats.

Images