Patent Application
20240410114
The invention relates to a coated paper, more particularly a translucent coated paper, a method for producing such a coated paper, the use of said coated paper as a packaging material, and a packaging comprising the coated paper.
Packaging generally refers to the covering or (partial or complete) wrapping of an object, more particularly for its protection or for better handling. Hence, a packaging material comprises the material that forms such packaging.
Packaging materials can be made out of paper, plastics and/or metals, for example. The present invention deals with paper-based packaging materials.
The main requirements for packaging materials of any origin are to protect the packaged goods from external influences and to prevent leakage of the packaged goods. For this purpose, the packaging material should fulfill different criteria depending on the packaged goods and packaging process. That is, suitable packaging materials should meet mechanical and process-specific requirements and have, for example, barrier properties against water, grease, oxygen, or mineral oil in the case of sensitive packaged goods, more particularly foodstuffs.
Depending on the packaging system, a packaging material should have sufficient tear resistance, a suitable coefficient of friction and flexibility; it should be either heat-sealable or compatible with a cold-seal adhesive, as well as printable from the outside and should not lose its protective effect during the entire conversion and packaging process.
Transparent or at least partially transparent (translucent) packaging materials are generally used whenever the object is to remain visible through the packaging despite being wrapped. In this way, for example, the object itself or prints on the object are recognizable from the outside despite the packaging, or a label or bar code on the object is readable.
Transparent or at least partially transparent packaging materials based on plastic films or transparent papers have been known for a long time.
For example, mail order catalogs or advertising brochures are shrink-wrapped in plastic film or transparent paper and sent by post, wherein the delivery address and bar code more particularly can be read through the packaging.
The term transparent paper frequently comprises the following papers:
As can be seen from the above, transparent papers are afflicted with drawbacks. Additionally, there is another drawback that generally affects all transparent papers, namely that transparent papers cannot be sufficiently recycled via the waste paper cycle.
Furthermore, many transparent papers are also not sufficiently suitable as packaging material, as they do not have the necessary strength combined with low grammage.
Transparent packaging made of plastic film is also not recyclable via the waste paper cycle, more particularly not together with the catalogs or advertising brochures that may be packed in it.
The object of the present invention therefore is to provide a translucent packaging material which has a sufficiently low opacity so that, for example, the packaged goods or an inscription on the packaged goods can be read through the packaging material, which can be recycled via the waste paper cycle, which has a sufficiently low grammage with sufficient strength, and/or which has sufficient sealed-seam strength.
Furthermore, the packaging material should preferably be suitable for food contact and for the toys and games sector; it should be biodegradable and producible mainly from renewable raw materials; its producibility should be economical; it should be suitable for packaging foodstuffs and should be usable in conventional packaging machines without having to substantially change the machine parameters, e.g. use of plastic-based packaging and paper-based packaging on the same packaging machine. For this, the packaging material should be sealable on the same sides, or back-to-back or inside to inside and on opposite sides (front/inside).
These objects are surprisingly solved by a coated paper according to claim 1, i.e. by a coated paper comprising a base paper containing less than 5 wt % of fillers and a coating color layer applied directly or indirectly to one side of the base paper, wherein the coating color layer comprises or consists of at least one heat-sealable material, and the coated paper has an opacity in the visible of less than 60%.
Preferably, the opacity in the visible is less than 55% and particularly preferably less than 50%.
Surprisingly, it has been found that the coated paper according to the invention, despite its low grammage, can be used directly in existing packaging machines for the packaging of packaged goods in plastic packaging without the packaging machine having to be significantly modified. More particularly, the good running properties of the paper (mechanical properties), the required opacity and the good heat-sealability have been proven to be advantageous, so that the paper can be used like a conventional plastic and can therefore replace plastic packaging. The coated paper according to the invention or packaging made from it can be easily recycled via the waste paper cycle.
All features of one embodiment defined in the present description and in the claims can be combined with features of another embodiment if the features of the different embodiments are not incompatible.
The terminology used in the description of the present disclosure is intended only to describe certain embodiments and should not be construed as limiting the subject matter. As used in the present description and claims, the singular forms “a”, “an” are to be understood to include the plural forms as well, unless the context clearly dictates otherwise. This also applies vice versa, i.e., the plural forms also 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 associated listed elements. Moreover, it is to be understood that the terms “include”, “including”, “comprise”, and/or “comprising”, when used in the present description and claims, specify the presence of the specified features, steps, elements, and/or components, but do not exclude the presence or addition of one or more other features, steps, elements, components, and/or groups thereof.
In the present description and claims, the terms “include”, “comprise”, and/or “comprising” may also mean “consisting of”, i.e., the presence or addition of one or more other features, steps, elements, components and/or groups is excluded.
In the present description and claims, a coated side of a paper is often referred to as the “B” side and an uncoated side of a paper is often referred to as the “A” side.
The coated paper according to the invention comprises a base paper and a coating color layer applied thereto, wherein the coating color layer comprises at least one polymer, and is characterized in that the coated paper has an opacity in the visible of less than 60%.
Preferably, the opacity in the visible is less than 55% and particularly preferably less than 50%.
Opacity is generally understood to be the opposite of transparency, i.e. a lack of transparency or permeability.
Opacity in the visible range therefore refers to the lack of light transmission in the visible range.
Opacity is therefore the opposite of transparency or transmission. Translucency describes a semi-transparency, i.e. an approximate but not complete transparency.
Opacity can also be expressed as the reciprocal of transmission.
The opacity can be determined in accordance with ISO 2471 (2008).
In principle, the base paper used for the coated paper according to the invention is not limited.
However, it is preferred that the grammage of the coated paper is 45 g/m2 or less, more particularly 40 g/m2 or less. Particularly preferred are grammages of the coated paper in the range of 30 g/m2 to 40 g/m2.
The grammage can be determined in accordance with ISO 536 (2020-05).
The opacity of the coated paper can be adjusted using such grammages without any drawbacks in terms of structural integrity.
Preferably, the base paper can comprise short fibers, long fibers, recycled pulp and/or alternative fiber materials, such as grass fibers, silphium fibers and/or other mechanically or chemically processed fiber materials, preferably from agricultural residues.
Further, it is preferred that the base paper comprises short fibers and long fibers, and that the weight ratio of short fibers to long fibers is greater than 1.
More particularly, the weight ratio of short fibers to long fibers is 60:40 to 70:30.
Long fibers preferably are fibers with a fiber length of 2.6 to 4.4 mm and short fibers preferably are fibers with a fiber length of 0.7 to 2.2 mm.
The coated paper according to the invention is further characterized in that the base paper contains less than 5 wt % of fillers.
Thus, in one embodiment, the base paper also may not contain any fillers.
Preferably, fillers are contained from 0 wt % or from more than 0 wt % to 5 wt %.
The percentages by weight refer to the total weight of the base paper.
Fillers comprise GCC (ground calcium carbonate), which is known for example under the trade name Hydrocarb 60 or Hydroplex 60, PCC (precipitated calcium carbonate), which is known for example under the trade name Precarb 105, natural kaolin and/or talc, as well as the usual additives, such as retention agents and/or sizing agents.
In a preferred embodiment, the coated paper according to the invention is characterized in that the coating color layer is heat-sealable. For this purpose, the coating color layer comprises at least one thermoplastic polymer.
The coated paper according to the invention is preferably further characterized in that at least one polymer in the coating color layer comprises a thermoplastic, heat-sealable polymer.
“Heat sealing” is preferably understood to mean the joining of two layers of the coated paper by exposure to localized heat.
The coated paper according to the invention is preferably further characterized in that the at least one heat-sealable material or polymer in the coating color layer is selected from the group comprising polyolefins, vinyl acetate polymers, (modified) vinyl acetate copolymers, polyvinyl alcohols (PVOH), grafted polyvinyl alcohols, ethylene vinyl alcohols, (meth)acrylate (co)polymers, more particularly ethylene acrylic acid copolymers and styrene acrylate copolymers, acrylic acid esters, (carboxylated) styrene-butadiene copolymers, polyurethanes, carbohydrates and carbohydrate derivatives, acrylate polymers, acrylic acid esters, aqueous synthetic resin dispersions, thermoplastic ethylene copolymers, natural rubbers, and/or polyurethanes.
Suitable heat-sealable materials or polymers are known, for example, under the trade names Hypod 2000, SealCoat MB46 HE, Cartaseal SWF, SealCoat HS 25, Rhobarr 320, EUKALIN 7238 VD, Decacode Seal, Aquasel 2330, Loctite Liofol CS22-096, Primeseal 22-096, S8128.
The at least one heat-sealable material or polymer is preferably contained in the coating color layer in an amount of 50 to 100 wt %, particularly preferably 80 to 100 wt %, based on the total weight of the coating color layer.
Preferably, waxes and/or inorganic pigments can be included as anti-blocking agents.
The coating color layer can also contain additives such as thickeners, e.g. acrylate-based thickeners; surfactants, e.g. sulfosuccinates; extensional rheology additives, e.g. acrylate-based extensional rheology auxiliaries; waxes, such as e.g. fatty acids or fatty acid amide-based waxes; additives to reduce abrasion sensitivity and increase slip, such as layer silicates, more particularly magnesium silicate hydrates or aluminosilicates; and/or crosslinking agents, such as aldehydes and polyvalent aldehydes, zirconates, polyvalent epoxides, epichlorohydrin resins, and/or hydrazides.
These additives are preferably each present in an amount of 0 or more than 0 wt % to 50 wt %, particularly preferably in an amount of 0 or more than 0 wt % to 20 wt %, based on the total weight of the coating color layer.
The coated paper according to the invention is preferably further characterized in that the coating color layer has a grammage of less than 10 g/m2.
Particularly preferred, the grammage of the coating color layer is in the range of 2 to 10 g/m2, more particularly 3 to 7 g/m2.
Such grammages ensure that the coated paper has an advantageous translucency without having any drawbacks in terms of structural integrity.
The coated paper according to the invention is preferably further characterized in that the coated paper has a cold seal seam strength of more than 3 N/15 mm, measured according to DIN 55529 (2012), when sealing B/B side (coated onto coated side).
The coated paper according to the invention is preferably further characterized in that the coated paper has a cold seal seam strength of more than 1.5 N/15 mm, measured according to DIN 55529 (2012), when sealing A/B side (uncoated onto coated side).
The seal seam strength for the coated paper can be determined as follows:
The coated paper is sealed at 3.3 bars for at least 0.3 s in the temperature range from 100° C. to 200° C. at right angles to the direction of paper flow and the seal seam strength is determined in accordance with DIN 55529 (2012).
The coated paper according to the invention is preferably further characterized in that the coated paper has a burst pressure according to Mullen of more than 150 kPa, particularly preferably more than 200 kPa.
The burst pressure (Mullen) is determined in accordance with ISO 2758 (2014-12), for example.
Such a burst pressure (Mullen) is advantageous because the burst pressure describes a strength value of the paper and the papers must feature high strengths even at low grammages. This is necessary in order to be able to use it during printing in the processing steps and finishing processes without any problems. For example, no creases must form in rotary printing processes or transfer papers using transfer calenders, and the paper must be able to withstand the corresponding tensions that can affect papers during processing, even with a low grammage.
The coated paper according to the invention is preferably further characterized in that the coated paper has a longitudinal tensile strength of more than 40 N/15 mm and/or a transverse tensile strength of more than 60 N/15 mm, measured according to ISO 1924-2 (2009).
The coated paper according to the invention is preferably further characterized in that the coated paper has a longitudinal elongation at break of >1.5%, preferably >2%, and/or a transverse elongation at break of >4%, preferably >5%, measured according to ISO 1924-2 (2009).
The coated paper according to the invention is preferably further characterized in that the coated paper has a roughness of <5 μm, preferably <4.5 μm, on the upper side of the coating color layer. The roughness can be determined in accordance with ISO 8791-4 (2008-05).
The coated paper according to the invention is preferably further characterized in that the base paper, preferably on the side to which the coating color layer is applied, has a roughness of ≥7 μm, preferably of ≤6 μm.
The coated paper according to the invention is preferably further characterized in that the base paper, preferably on the side to which the coating color layer is not applied, i.e. on the back side, has a roughness of 55 μm, preferably of 4 μm.
The coated paper according to the invention is preferably further characterized in that the coated paper has a thickness of less than 60 μm.
A thickness of 30 to 50 μm is particularly preferred.
The coated paper according to the invention is also characterized in that it offers the possibility, in addition to the visual inspection of the contents due to the translucency, of checking the contents by means of a code printed on the packaged goods.
The coated paper according to the invention is further characterized in that it offers the possibility of printing a code on the outside of the paper by means of ink jet printing, for example, and thus of marking goods and reading out code contents.
The present invention also relates to a coated paper as mentioned above, characterized in that a precoat or surface pigmentation comprising a polymer binder, preferably starch and/or latexes and/or addition of pigments, e.g. CaCO3, is present between the base paper and the coating color layer.
Also possible are embodiments in which a precoat or a surface pigmentation comprising a polymer binder, preferably starch and/or latexes and/or the addition of pigments, e.g. CaCO3, is present on the side of the base paper on which the coating color layer is not present, i.e. on the back side.
As already discussed above, known translucent papers have disadvantages in the recycling process. These are often caused by greatly increased reject portions or sticky impurities.
Test methods exist for evaluating the recyclability of packaging paper with regard to these criteria on a laboratory scale. Common test methods include PTS-RH 021:2012—Category II and UNI 11743:2019. These provide information on the evaluation of a packaging material with regard to recyclability in established paper recycling plants. They simulate their process steps on a laboratory scale and evaluate them using a specially developed evaluation system. Process steps are: Disintegrating—(multiple) sorting—sheet forming.
To improve these parameters, the coated paper according to the invention preferably has a minimal content of non-paper components which do not cause any problems in the recycling process.
The coated paper according to the invention thus preferably fulfills the recycling test according to PTS-RH 021:2012—Category II and/or according to UNI 11743:2019.
The coated paper according to the invention can be obtained economically using known manufacturing processes.
It is preferred, however, to obtain the coated paper according to the invention by a process in which an aqueous suspension comprising the starting materials of the coating color layer is applied to the base paper, wherein the aqueous application suspension has a solids content of 20 to 60 wt %, preferably of 30 to 50 wt %, and is applied by means of a curtain coating process with an operating speed of the coating system of at least 200 m/min.
This process is more particularly advantageous from an economic point of view and due to the even application over the paper web.
If the solids content falls below a value of around 30 wt %, the economic efficiency deteriorates because a large amount of water has to be removed in a short time by gentle drying, which has a detrimental effect on the coating speed. If, on the other hand, the value of 60 wt % is exceeded, the only effect is an increased technical effort to ensure the stability of the coating color curtain during the coating process and the drying of the applied film, since the machine has to run very quickly again in this case.
In the curtain coating process, a free-falling curtain of a coating dispersion is formed. The coating dispersion in the form of a thin film (curtain) is “poured” onto a substrate by free fall in order to apply the coating dispersion to the substrate. DE 10 196 052 T1 discloses the use of the curtain coating process in the production of information recording materials, wherein multilayer recording layers are realized by applying the curtain, which consists of several coating dispersion films, to substrates.
In a preferred embodiment of the process according to the invention, the aqueous, deaerated application suspension has a viscosity of about 100 to about 800 mPa*s (Brookfield, 100 rpm, 20° C.). If the value falls below about 100 mPa*s or exceeds about 800 mPa*s, the runnability of the coating mass on the coating unit becomes poor. Particularly preferably, the viscosity of the aqueous, deaerated application suspension is about 200 to about 500 mPa*s.
In a preferred embodiment, the surface tension of the aqueous application suspension can be adjusted to about 25 to about 70 mN/m, preferably to about to about 60 mN/m (measured in accordance with the standard for bubble pressure tensiometry (ASTM D 3825-90), as described below), in order to optimize the process. Better control over the coating process can be achieved by determining the dynamic surface tension of the coating color and adjusting it by selecting the appropriate surfactant and determining the required amount of surfactant.
The dynamic surface tension is measured using a bubble pressure tensiometer. The maximum internal pressure of a gas bubble formed via a capillary in a liquid is measured. According to the Young-Laplace equation, the internal pressure p of a spherical gas bubble (Laplace pressure) depends on the radius of curvature r and the surface tension a:
When a gas bubble is produced at the tip of a capillary in a liquid, the curvature first increases and then decreases again, resulting in the occurrence of a pressure maximum of. The greatest curvature and thus the greatest pressure occur when the radius of curvature corresponds to the capillary radius.
Pressure characteristics for the bladder pressure measurement, position of the pressure maximum:
The radius of the capillary is determined using a reference measurement carried out with a liquid with a known surface tension, usually water. Once the radius is known, the surface tension can be calculated from the maximum pressure, pmax. Since the capillary is immersed in the liquid, the hydrostatic pressure p0 resulting from the immersion depth and the density of the liquid must be subtracted from the measured pressure (this is done automatically with modern instruments). This results in the following formula for the bubble pressure process:
The measured value corresponds to the surface tension at a certain surface age, the time from the start of bubble formation to the occurrence of the pressure maximum. By varying the speed at which the bubbles are produced, the dependence of the surface tension on the surface age can be acquired, resulting in a curve in which the surface tension is plotted against time.
This dependency plays an important role in the use of surfactants, as the equilibrium value of the interfacial tension is not even reached in many processes due to the sometimes low diffusion and adsorption rates of surfactants.
The individual coatings can be formed on-line on a paper machine with a coating unit or in a separate coating process off-line on a coating machine.
In other embodiments, the individual layers can also be applied to the base paper using the following processes:
The coating color layer can be applied to the base paper and/or to existing precoats using a printing process.
The coating color layer can be applied to the base paper and/or to existing precoats by extrusion.
This technique has the advantage that significantly more material can be applied, but this is only of interest if the overall product does not need to be recyclable as paper. The disadvantages are lower application speeds, higher energy consumption and a higher minimum application weight.
The coating color layer can be applied by laminating or lining paper, e.g. in the form of plastic films, on the base paper and/or on existing precoats.
The coating color layer and the precoat can also be applied one after the other over a number of application steps.
The uncoated side can be smoothed by applying heat and/or pressure.
The present invention further relates to a coated paper obtainable by the process described above.
The present invention also relates to the use of a coated paper as described above or a coated paper obtainable by the process described above as a packaging material, also in combination with cardboard and/or paperboard.
In particular, the coated paper as described above or the coated paper obtainable by the process described above is suitable as packaging material for:
The present invention also relates to a packaging comprising a coated paper as described above, also in combination with cardboard and/or paperboard.
The packaging can also be a heat-sealed packaging.
The packaging can also be a cold-sealed packaging.
Preferably, the packaging has a cold seam sealing strength of 3 N/15 mm or more when sealing is done with the side coated with sealing layer on the side coated with sealing layer (B/B).
Preferably, the packaging has a cold seam sealing strength of 1.5 N/15 mm or more when sealing is done with the side coated with sealing layer on the side not coated with sealing layer (B/A).
The paper can be coated on one or both sides, over the entire surface or partially with a paint from the above-mentioned material classes in order to further improve the (B/A) sealing in demanding applications (time <1 s, pressure ≤3.3 bar; increased temperature, for example 140° C. cold seam sealing strength >2 N/15 mm) that require a high sealing force.
The paper can be partially coated with a paint from the above-mentioned material classes on the coated or printed side in order to improve the tightness of the packaging, more particularly at the triple point (layer jump from 2 to 4 layers; see
In a particular embodiment, the choice of sealing medium/coating material can also achieve further properties such as grease tightness (KIT >/=3; PKOT KAT 1; HVTR <100 g/m2/d or even a WVTR <100 g/m2/d at 23° C./50% r.h.).
The invention is explained in detail below with reference to non-limiting examples.
The following coatings were applied to a base paper of 35 g/m2 with a content of 60% long fibers and 40% short fibers. The base paper additionally contains 2 wt % of filler.
The precoat contains 100 wt % of starch. The grammage of the precoat is 1 g/m2.
The coating color layer has the following composition:
The coating color layer has a grammage of 5 g/m2.
For this, the precoat was applied using a film press. The coating color layer was applied using a curtain coater.
The coated paper obtained was examined. The results are shown in the following table:
A deck of playing cards is wrapped on packaging machines designed for fold wrapping as shown in
Sealing is carried out using heat-sealing bars lengthwise and crosswise. Sealing is carried out with the inner side that is coated with a sealing layer onto the uncoated upper side (A/B sealing).
A cold seal seam strength of 1.5 N/15 mm has proven to be sufficient for this type of packaging.
The packaged deck is then either packed in another box or placed in a suitable compartment in a game box.
A few playing cards are wrapped on packaging machines designed for tubular bag packaging as shown in
Sealing is carried out using heat-sealing bars lengthwise and crosswise. Sealing is carried out with the inner side that is coated with a sealing layer onto the inner side that is coated with a sealing layer (B/B sealing).
A cold seal seam strength of 3 N/15 mm has proven to be sufficient for this type of packaging.
The packaged cards are then either packed in another box or placed in a suitable compartment in a game box.
Various tests were carried out with QR codes in order to test the possibility of marking both by printing them directly on the uncoated side of the paper according to the invention and on a flat filling good (e.g. playing card cardboard) and reading them through the translucent paper.
The printer used was a standard HP Office Jet Pro 8210 with the corresponding HP ink 957. A “REA VeriCube” code reader and tester was used as the reader.
The software used was “TransWin32 V.1.2.0.0/15701r.
The following results were achieved:
1. QR Code with Little Content Printed on the Uncoated Outside of the Paper: Code Content: Readable
The QR code is shown in
2. QR Code with More Extensive Content Printed on the Uncoated Outside of the Paper: Code Content: Readable
The QR code is shown in
3. QR Code with Little Content and Reading Through the Translucent Paper with Tight-Fitting Paper on the Flat Filling Good. Code Content: Readable
The QR code is shown in
4. QR Code with Little Content and Reading Through the Translucent Paper with not Tight-Fitting Paper on the Flat Filling Good. Code Content: Readable.
The QR code is shown in
5. QR Code with Extensive Content and Reading Through the Translucent Paper with Tight-Fitting Paper on the Flat Filling Good. Code Content: Readable
The QR code is shown in
The following coatings were applied to a base paper of 35 g/m2 with a content of 40% long fibers and 60% short fibers. The base paper additionally contains 2 wt % of filler.
The precoat contains 100 wt % of starch. The grammage of the precoat is 1 g/m2.
The coating color layer has the following composition:
The coating color layer has a grammage of 5 g/m2.
The precoat was applied using a film press. The coating color layer was applied using a curtain coater.
The coated paper obtained was examined. The results are shown in the following table:
The following coatings were applied to a base paper of 25 g/m2 with a content of 40% long fibers and 60% short fibers. The base paper additionally contains 2 wt % of filler.
The precoat contains 100 wt % of starch. The grammage of the precoat is 1 g/m2.
The coating color layer has the following composition:
The coating color layer has a grammage of 4 g/m2.
The precoat was applied using a film press. The coating color layer was applied using a curtain coater.
The coated paper obtained was examined. The results are shown in the following table:
The following coatings were applied to a base paper of 25 g/m2 with a content of 40% long fibers and 60% short fibers. The base paper additionally contains 2 wt % of filler.
The precoat contains 100 wt % of starch. The grammage of the precoat is 1 g/m2.
The coating color layer has the following composition:
The coating color layer has a grammage of 3 g/m2.
The precoat was applied using a film press. The coating color layer was applied using a curtain coater.
The coated paper obtained was examined. The results are shown in the following table:
The following coatings were applied to a base paper of 30 g/m2 with a content of 40% long fibers and 60% short fibers. The base paper additionally contains 2 wt % of filler.
The precoat contains 100 wt % of starch. The grammage of the precoat is 1 g/m2.
The coating color layer has the following composition:
The coating color layer has a grammage of 4 g/m2.
The precoat was applied using a film press. The coating color layer was applied using a curtain coater.
The coated paper obtained was examined. The results are shown in the following table:
The following coatings were applied to a base paper of 30 g/m2 with a content of 40% long fibers and 60% short fibers. The base paper additionally contains 2 wt % of filler.
The precoat contains 100 wt % of starch. The grammage of the precoat is 1 g/m2.
The coating color layer has the following composition:
The coating color layer has a grammage of 3 g/m2.
The precoat was applied using a film press. The coating color layer was applied using a curtain coater.
The coated paper obtained was examined. The results are shown in the following table:
The following coatings were applied to a base paper of 40 g/m2 with a content of 40% long fibers and 60% short fibers. The base paper additionally contains 2 wt % of filler.
The precoat contains 100 wt % of starch. The grammage of the precoat is 1 g/m2.
The coating color layer has the following composition:
The coating color layer has a grammage of 4 g/m2.
The precoat was applied using a film press. The coating color layer was applied using a curtain coater.
The coated paper obtained was examined. The results are shown in the following table:
All examples were produced and tested using Hypod 2000 or Sealcoat MB 46 HE as the sealing medium. The sealing media can be replaced by other sealing media with comparable values in accordance with the present application.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2021 125 950.9 | Oct 2021 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/077413 | 9/30/2022 | WO |
