DE102022210442A1 - Bio-based composites as a water vapor barrier on paper - Google Patents

Abstract

The application relates to a coated paper comprising a base paper and at least one coating layer applied directly or indirectly to the base paper, the coating layer comprising a) at least one natural wax and/or at least one carboxylic acid component and b) at least one natural resin; wherein the permeability of at least one gas through the coated paper is reduced compared to the base paper. The registration also concerns the coating color used to produce the coated paper, the manufacturing process and packaging made with it.

Description

FIELD OF INVENTION

The invention relates to coated papers with a high barrier performance for gases and moisture for use as packaging material

BACKGROUND OF THE INVENTION

Packaging accounts for a large proportion of global plastic pollution, which is why the search for alternatives made from biodegradable materials is being driven forward.

Packaging food is particularly challenging because it requires good barrier performance against oxygen, water vapor and microorganisms. Packaging materials for food often consist of plastics, for example polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyethylene (PE) and polypropylene (PP), as these have good barrier properties as well as low weight and high mechanical stability.

Paper-based packaging materials have many advantages over plastic materials, such as renewability, recyclability and compostability. However, their use is limited due to their often poor barrier properties and high sensitivity to moisture.

To improve barrier properties, the paper-based packaging material can be laminated with aluminum or petroleum-based polymers such as PE, EVOH and PVC derivatives. However, these coatings complicate waste sorting and thus recycling and reduce compostability. Therefore, the use of barrier layers based on natural, bio-based polymers or replacement of the conventional metal or plastic-based layer is very desirable from an ecological point of view.

Examples of natural polymers that have been tested for packaging applications include chitosan, hemicelluloses, microfibrillated cellulose and starch. However, many of the natural polymers are hydrophilic and the films made from these materials are often hygroscopic, resulting in a partial loss of their barrier properties at high humidity.

JP2006096981A describes a coating liquid for a substrate such as film, sheet, paper, fabric or nonwoven fabric, which gives the substrate moisture resistance. The main components of the coating liquid are shellac and paraffin wax. In order to achieve the desired moisture resistance, the applied layer must be heat treated at a temperature of at least 90 °C for at least 5 s. The water vapor permeability should be less than 50 g/(m ² d). However, the papers coated in this way are poorly biodegradable.

WO 2020/152292A1 describes a barrier paper for use as food packaging. The barrier papers consist of a paper substrate with a mass fraction of cellulose fibers of greater than or equal to 90% and a barrier layer arranged on the front and/or back of the paper substrate. The barrier layer contains a polymeric stabilizer such as polyvinyl alcohol or starch and at least one wax such as beeswax and/or at least one vegetable oil such as olive soy or rapeseed oil. The barrier paper is intended to ensure water vapor permeability DIN 53122-1 of less than or equal to 150 g/(m ² d). However, there is no evidence of such values.

WO 2020/011824A1 describes a packaging system consisting of a first paper layer with particulate activated carbon, a first barrier layer arranged on the paper layer made of a binder and a pigment and a second barrier layer arranged on the first barrier layer, comprising an acrylate copolymer and a wax. The barrier paper is intended to ensure water vapor permeability DIN 53122-1 at a climate of 23 °C and 85% of less than or equal to 125 g/(m ² d). However, there is no evidence of such values here either.

US9,902815 B2 and the scientific publication Hult et al. 2013 published by the same authors describe processes for the esterification of lignin with fatty acids, in particular the lignin is esterified with a mixture of tall oil and fatty acids. The main component of this mixture is unseeded fatty acids such as oleic acid, linoleic acid and linolenic acid, which were reacted with the lignin to varying degrees of esterification.

SUMMARY OF THE INVENTION

The present invention is based, among other things, on the surprising discovery that the combination of at least one natural wax or carboxylic acid component on the one hand and at least one natural resin on the other hand results in a coating layer with a high barrier effect against gases and moisture, which is nevertheless biodegradable. A coated paper according to the invention produced with this coating layer has a sufficient barrier effect for use in the food industry and is nevertheless biodegradable and recyclable. The coating layer according to the invention can have a binary composition, but also a ternary composition of natural resin, natural waxes and carboxylic acid components. The ternary composition can, among other things, lead to an even higher barrier effect, as well as imparting the coated paper further properties such as increased grease resistance.

1. a) wenigstens ein natürliches Wachs und/oder wenigstens eine Carbonsäurekomponente und
2. b) wenigstens ein Naturharz umfasst;

wobei die Permeabilität wenigstens eines Gases durch das gestrichene Papier im Vergleich zum Basispapier reduziert ist.Consequently, the present invention relates, in a first aspect, to a coated paper comprising a base paper and at least one coating layer applied directly or indirectly to the base paper, the coating layer

1. a) at least one natural wax and/or at least one carboxylic acid component and
2. b) comprises at least one natural resin;

wherein the permeability of at least one gas through the coated paper is reduced compared to the base paper.

1. a) wenigstens ein natürliches Wachs und/oder wenigstens eine Carbonsäurekomponente und
2. b) wenigstens einen Filmbildner umfasst;

wobei die Permeabilität wenigstens eines Gases durch das gestrichene Papier im Vergleich zum Basispapier reduziert ist.Comparable properties with regard to the barrier effects for gases and moisture could surprisingly be achieved for a coated paper even without the natural resin if the natural wax or the carboxylic acid component together with at least one film former, in particular a cellulose derivative, is applied as a coating layer to the base paper. According to a second aspect, the invention therefore relates to a coated paper comprising a base paper and at least one coating color layer applied directly or indirectly to the base paper, the coating color layer

1. a) at least one natural wax and/or at least one carboxylic acid component and
2. b) comprises at least one film former;

wherein the permeability of at least one gas through the coated paper is reduced compared to the base paper.

The barrier effect and biodegradability according to the invention is achieved with the binary or tertiary coating colors with the components described above and a suitable solvent.

Consequently, according to a third aspect, the invention relates to a coating color for coating papers, comprising the components defined according to the first or second aspect and a solvent selected from water, tetrahydrofuran (THF), ethanol, methanol and ethyl acetate, preferably the solvent is water.

1. a) Herstellen einer Streichfarbe durch Mischen der einzelnen Komponenten;
2. b) Bereitstellen eines Basispapiers;
3. c) Auftrag der Streichfarbe auf das Basispapier, bevorzugt mittels Vorhang- oder Rakelverfahren; und
4. d) Aushärtung der Streichfarbe unter Ausbildung der Streichfarbenschicht.

The barrier effect of the coating layer in the coated paper, which is essential here, is achieved in particular with the method used according to the invention for producing the coated paper. Consequently, according to a fourth aspect, the invention relates to a method for producing a coated paper with a base paper and a coating layer, comprising the steps:

1. a) Producing a coating colour by mixing the individual components;
2. b) providing a base document;
3. c) application of the coating colour to the base paper, preferably by curtain or doctor blade method; and
4. d) Hardening of the coating colour to form the coating layer.

According to a fifth aspect, the invention relates to a packaging comprising the coated paper according to the first or second aspect.

CHARACTERS

• 1 shows a diagram of the measurement results of the WVTR measurements of shellac produced according to the invention with binary coating color layers made of candelilla wax with a constant application weight and varying ratio of shellac to candelilla wax from Example 3.1.
• 2 shows a diagram of the measurement results of the WVTR measurements of shellac produced according to the invention with binary coating color layers made of candelilla wax with a constant ratio of shellac to candelilla wax and varying application weight from Example 3.1.
• 3 shows a diagram of the results of the WVTR measurements over the storage time from Example 3. The papers with the coating consisting of 80% candelilla wax dispersion and 20% shellac were tested after 10, 50, 100, 150, 200 and 250 days of storage.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

In the context of the present invention and in accordance with the general understanding in the field of paper technology, the term “coating paint” refers to paints containing or consisting of binders, additives and optionally pigments or matrix pigments that are applied to the paper surface using special coating devices for surface finishing or -modification of a base paper can be applied (“coated”). Papers made in this way are called “coated papers”.

In the context of the present invention, a "coated paper" is understood to mean a base paper which comprises one or more layers applied by coating, i.e. coating color layers. Possible layers of such a coated paper substrate are functional layers and structure-forming layers (such as leveling layers to smooth the surface).

According to the invention, the term “coating paint” is used as a generic term for all spreadable coating compositions, preparations and/or solutions in the paper industry for treating, modifying or refining a paper surface. The term “coating layer” refers to the coating color applied and hardened to the base paper.

“Paper” is a flat material that essentially consists of fibers of plant origin and is formed by dewatering a fiber suspension on a sieve. The resulting fiber fleece is compacted and dried. Within the scope of this invention, the flat materials “cardboard” and “cardboard”, which are produced in the same way, are also subsumed under paper. A distinction is made between paper, cardboard and cardboard only on the basis of the basis weight, with cardboard having a weight per square meter of greater than 600 g/m ² , cardboard having a weight per square meter of greater than 150 and less than or equal to 600 g/m ² and paper having a weight per square meter of less than or equal to 150 g/m ² .

Coated paper and coating paint

1. a) wenigstens ein natürliches Wachs und/oder wenigstens eine Carbonsäurekomponente und
2. b) wenigstens ein Naturharz umfasst;

wobei die Permeabilität wenigstens eines Gases durch das gestrichene Papier im Vergleich zum Basispapier reduziert ist.According to the first aspect, the present invention relates to a coated paper, comprising a base paper and at least one coating color layer applied directly or indirectly to the base paper, the coating color layer

1. a) at least one natural wax and/or at least one carboxylic acid component and
2. b) comprises at least one natural resin;

wherein the permeability of at least one gas through the coated paper is reduced compared to the base paper.

According to one embodiment of the coated paper, the permeability of at least one gas at the same total application amount is lower than the permeability of a coated paper with the same base paper and one coating color layer made of the natural resin and one coating color coating made of a natural wax and/or a carboxylic acid component. Due to this effect of the coating color layer according to the invention, it is also referred to as a “barrier layer”.

The coating layer reduces the permeability of at least one gas through the coated paper compared to the base paper. This can be oxygen (O ₂ ), nitrogen (N ₂ ), carbon dioxide (CO ₂ ), methane (CH ₄ ), hydrogen (H ₂ ), water vapor or mixtures thereof, for example air. In particular, the water vapor permeability (WVTR) is reduced.

It is assumed that the combination with at least one natural resin limits the crystallization of the natural waxes and carboxylic acid components on the surface. This creates improved water vapor barriers, since crystalline structures lead to superhydrophobic properties through the formation of structures on the surface, but do not create a homogeneous, closed coating, which is required to prevent water vapor molecules from permeating.

By using the bio-based raw materials mentioned, a reduction in plastic pollution in the environment is achieved using raw materials with improved recyclability and biodegradability. Furthermore - as shown in the examples - the amount of stabilizer used, which is often poorly biodegradable, can be reduced by using the natural resin.

With the coating color layer according to the invention, a coated paper with a high barrier performance, in particular a very low WVTR, can be achieved. According to one embodiment, the WVTR is not more than 50 g m ^-2 d ^-1 at a basis weight of the coating color of 10 ± 1 g m ^-2 .

The WVTR of the coated paper according to the invention can be, for example, 50 gm ^-2 ·d ^-1 , 48 g·m ^-2 ·d ^-1 , 46 g·m ^-2 ·d ^-1 , 44 g·m ^-2 ·d ^-1 , 42 g·m ^-2 ·d ^-1 , 40 g·m ^-2 ·d ^-1 , 38 gm ² d ^-1 36 g·m ^-2 ·d ^-1 , 34 g·m ^-2 ·d ^-1 , 32 g·m ^-2 ·d ^-1 , 30 g·m ^-2 ·d ^-1 , 28 g·m ^-2 ·d ^-1 , 26 gm ² d ^-1 , 24 g·m ^-2 ·d ^-1 , 22 g·m ^-2 ·d ^-1 , 20 g·m ^-2 ·d ^-1 , 18 g·m ^-2 ·d ^-1 , 16 g·m ^-2 ·d ^-1 , 14 g·m ^-2 ·d ^-1 , 12 g·m ^-2 ·d ^-1 , 10 g·m ^-2 ·d ^-1 , 8 g·m ^-2 ·d ^-1 , 6 g·m ^-2 ·d ^-1 , 4 g·m ^-2 ·d ^-1 , 2 g·m ^-2 ·d ^-1 , 1 g·m ^-2 ·d ^-1 . By selecting suitable components of the coating color and adjusting the crystallinity, a WVTR of not more than 20 g·m ^-2 ·d ^-1 , or even not more than 10 g·m ^-2 ·d ^-1 can be achieved.

The natural resin is preferably an organic, chemically/thermally crosslinkable matrix. According to one embodiment, the natural resin is selected from shellac, turpentine, balsam, gum lac, rosin, sandarac and mastic. The natural resin is preferably shellac.

Shellac is a resinous substance that is obtained from the excreta of the lac insect Kerria lacca (plant lice, family Kerridae) after it sucks on certain plants. It consists largely (65-75%) of free and esterified aliphatic and aromatic polyhydroxy acids. The main building blocks are aleuritic acid (up to 32%) and shellolic acid. If only these main components are taken into account, the calculation shows that three to four molecules are linked to each other (tri- and tetramers). Since there are several hydroxy and carboxy groups in the monomers, three-dimensional networks can form - as is usual in thermosets. Other ingredients include dyes (4-8%), bitter substances and some wax (shellac wax; reddish brown, brittle, very hard, ceryl lignocerate, ceryl cerotinate and wax alcohols). Shellac is biodegradable.

Carboxylic acid components that can be used according to the invention are, for example, fatty acids, fatty acid amides, fatty acid esters, salts of fatty acids, hydroxy fatty acids, hydroxy fatty acid amides, hydroxy fatty acid esters, salts of hydroxy fatty acids, or dicarboxylic acids, as well as their dicarboxylic acid esters, dicarboxylic acid amides or salts of dicarboxylic acids. Examples of dicarboxylic acids that can be used according to the invention are tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, icosanedioic acid, or docosanedioic acid.

The carboxylic acid component can be a saturated or unsaturated fatty acid with 12 to 40 carbon atoms. Examples of saturated fatty acids are lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotinic acid, montanic acid, melissic acid, lacceric acid, geddic acid. Examples of unsaturated fatty acids include myristoleic acid, palmitoleic acid, margaroleic acid, petroselinic acid, oleic acid (OA), elaidic acid, vaccenic acid, gadoleic acid, gondoic acid, cetoleic acid, erucic acid, and nervonic acid. Examples of unsaturated fatty acids are linoleic acid (LA), α-linolenic acid (ALA), γ-linolenic acid (GLA), calendulic acid, punicic acid, alpha-eleostearic acid, beta-eleostearic acid, stearidonic acid, arachidonic acid, eicosapentaenoic acid (timnodonic acid, EPA), docosadienoic acid, docosatetraenoic acid (adrenic acid, ADA), docosapentaenoic acid, (clupa(no)don acid), (DPA-3) docosahexaenoic acid (cervic acid, clupanodonic acid, DHA) and tetracosahexaenoic acid (nisic acid).

According to one embodiment, the fatty acid used as the carboxylic acid component has 16 to 18 carbon atoms and 0 or 1 carbon-carbon double bond. According to one embodiment, the fatty acid is selected from margaric acid, stearic acid, palmitic acid, linoleic acid, α-linolenic acid, γ-linolinic acid. According to one embodiment, the carboxylic acid component is stearic acid or its amide or salt.

Fatty acid salts according to the invention are chromium (III) chloride complexes with fatty acids, as well as aluminum, calcium, sodium, potassium and ammonium salts. Preferred fatty acid salts are monovalent salts of sodium, potassium or ammonium ions.

According to one embodiment, it is a fatty acid mixture. According to one embodiment, the fatty acid mixture is a mixture of stearic acid, palmitic acid, oleic acid, linoleic acid, and/or linolenic acid. Further examples of fatty acid mixtures are a mixture of stearic acid and palmitic acid, a mixture of stearic acid, palmitic acid and oleic acid, a mixture of stearic acid, linoleic acid and linolenic acid, a mixture of stearic acid, palmitic acid and linoleic acid, a mixture of stearic acid, palmitic acid and linolenic acid, a mixture of stearic acid, oleic acid and linolenic acid, a mixture of stearic acid, oleic acid and linolenic acid, a mixture of stearic acid, linoleic acid and linolenic acid. A preferred mixture is a mixture of stearic acid and palmitic acid.

According to the invention, possible waxes include carnauba wax, candelilla wax, beeswax, Chinese wax and Japanese wax. The wax is preferably carnauba wax or candelilla wax.

According to one embodiment, the polymeric stabilizer is a crosslinked or uncrosslinked stabilizer. The polymeric stabilizer prevents the agglomeration of finely divided coating color components. The stabilizer can also act as a binder when used in larger quantities. The polymeric stabilizer can be selected from the group consisting of polyvinyl alcohol, starch, carboxyl group-modified polyvinyl alcohol, ethylene-vinyl alcohol copolymer, a combination of polyvinyl alcohol and ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, silanol group-modified polyvinyl alcohol, diacetone-modified polyvinyl alcohol , modified polyethylene glycol, unmodified polyethylene glycol, a-isodecy!- cj-hydroxy-poly(oxy-1,2-ethanediyl), styrene-butadiene latex, styrene-acrylate polymers, acrylic copolymers, carboxyl group-modified polyvinyl alcohol, ethylene-vinyl alcohol copolymer, a combination of polyvinyl alcohol and ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, silanol group-modified polyvinyl alcohol, diacetone-modified polyvinyl alcohol, modified polyethylene glycol, unmodified polyethylene glycol, a-isodecyl-cj-hydroxy-poly (oxy-1,2-ethanediyl ), styrene-butadiene latex, styrene-acrylate polymers, acrylic copolymers and mixtures thereof and mixtures thereof. According to one embodiment, the polymeric stabilizer is polyvinyl alcohol. Polyvinyl alcohol is commercially available with various degrees of hydrolysis and viscosities. Polyvinyl alcohols with a viscosity of 2-10 mPas (measured as a 4% aqueous solution at 20 °C DIN 53015 / JIS K 6) and a degree of hydrolysis of > 80 mol% are preferably used. Commercially available examples are KURARAY POVAL® 6-88 and KURARAY POVAL® 6-98.

According to one embodiment, the coating layer comprises a carboxylic acid component, a natural resin and optionally a polymeric stabilizer. In this composition, the proportion of the carboxylic acid component based on the total mass of the coating layer can be in the range from 15 to 85% by weight. For example, the carboxylic acid component can have a proportion of 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight % by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight or 85% by weight. According to one embodiment, the proportion of the carboxylic acid component is in the range from 25 to 75% by weight. According to one embodiment, the proportion of the carboxylic acid component is in the range from 30 to 75% by weight. According to one embodiment, the proportion of the carboxylic acid component is in the range from 40 to 65% by weight.

In the binary composition of the coating layer of carboxylic acid component, natural resin and optionally polymeric stabilizer, the proportion of natural resin based on the total mass of the coating layer can be in the range 10 to 70 wt.%. For example, the natural resin can have a proportion of 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.%, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 60 wt.%, 65 wt.% or 70 wt.%. According to one embodiment the proportion of natural resin based on the total mass of the coating layer is in the range from 20 to 60 wt.%. According to one embodiment, the proportion of natural resin based on the total mass of the coating layer is in the range from 25 to 55 wt.%. According to one embodiment, the proportion of natural resin based on the total mass of the coating layer is in the range from 30 to 50 wt.%.

In the composition of the coating color layer of carboxylic acid component, natural resin and polymeric stabilizer, the proportion of the polymeric stabilizer based on the total mass of the coating color layer can be below 30 wt.%. For example, the polymeric stabilizer can have a proportion of 0.1 wt.%, 0.5 wt.%, 1 wt.%, 1.5 wt.%, 2.0 wt.%, 3 wt.%, 4 wt.%, 5 wt.%, 6 wt.%, 7 wt.%, 8 wt.%, 9 wt.%, 10 wt.%, 12 wt.%, 14 wt.%, 16 wt.%, 18 wt.%, 20 wt.%, 22 wt.%, 24 wt.%, 26 wt.% or 28 wt.%. According to one embodiment, the proportion of the polymeric stabilizer based on the total mass of the coating color layer is below 20 wt.%. According to one embodiment, the proportion of the polymeric stabilizer based on the total mass of the coating color layer is in the range of 1 to 15 wt.%. According to one embodiment, the proportion of the polymeric stabilizer based on the total mass of the coating color layer is in the range of 2 to 10 wt.%.

According to one embodiment, the binary coating layer comprises a natural wax, a natural resin and optionally a polymeric stabilizer. In this composition, the proportion of natural wax based on the total mass of the coating layer can be in the range from 15 to 95% by weight. For example, the carboxylic acid component can have a proportion of 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight. -%, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, 90% by weight or 95% by weight . According to one embodiment, the proportion of natural wax is in the range from 30 to 95% by weight. According to one embodiment, the proportion of natural wax is in the range from 40 to 90% by weight. According to one embodiment, the proportion of natural wax is in the range from 50 to 85% by weight. According to one embodiment, the proportion of natural wax is in the range from 60 to 80% by weight.

In the composition of the coating layer made of natural wax, natural resin and optionally polymeric stabilizer, the proportion of natural resin based on the total mass of the coating layer can be in the range from 5 to 70% by weight. For example, the natural resin can have a proportion of 5% by weight, 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight % by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight or 70% by weight. According to one embodiment, the proportion of natural resin based on the total mass of the coating color layer is in the range from 5 to 60% by weight. According to one embodiment, the proportion of natural resin based on the total mass of the coating color layer is in the range from 10 to 40% by weight. According to one embodiment, the proportion of natural resin based on the total mass of the coating color layer is in the range from 20 to 40% by weight.

In the composition of the coating layer of natural wax, natural resin and polymeric stabilizer, the proportion of the polymeric stabilizer based on the total mass of the coating layer can be below 30 wt.%. For example, the polymeric stabilizer can have a proportion of 0.1 wt.%, 0.5 wt.%, 1 wt.%, 1.5 wt.%, 2.0 wt.%, 3 wt.%, 4 wt.%, 5 wt.%, 6 wt.%, 7 wt.%, 8 wt.%, 9 wt.%, 10 wt.%, 12 wt.%, 14 wt.%, 16 wt.%, 18 wt.%, 20 wt.%, 22 wt.%, 24 wt.%, 26 wt.% or 28 wt.%. According to one embodiment, the proportion of the polymeric stabilizer based on the total mass of the coating layer is below 20 wt.%. According to one embodiment, the proportion of the polymeric stabilizer based on the total mass of the coating color layer is in the range from 1 to 15 wt. %. According to one embodiment, the proportion of the polymeric stabilizer based on the total mass of the coating color layer is in the range from 2 to 10 wt. %.

According to one embodiment, the coating layer comprises at least one film former. The film former can be selected from methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose. According to one embodiment, the coating layer comprises one, two, three, four, five, six, seven, eight, nine, or ten film formers. According to one embodiment, the coating layer comprises the two film formers methyl cellulose, carboxymethyl cellulose.

According to one embodiment, the proportion of film formers based on the total mass of the coating color layer is in the range from 0.2 to 5.0% by weight. For example, the film formers can have a share of 0.2% by weight, 0.4% by weight, 0.6% by weight, 0.8% by weight, 1.0% by weight, 1.2% by weight, 1 .4% by weight, 1.6% by weight, 1.8% by weight, 2.0% by weight, 2.4% by weight, 2.8% by weight, 3.0 wt.%, 3.4 wt.%, 3.8 wt.%, 4.0 wt.%, 4.4 wt.%, 4.8 wt.%, 5.0 wt. -%. exhibit. According to one embodiment, the proportion of film formers based on the total mass of the coating color layer is in the range from 0.3 to 2.0% by weight. According to one embodiment, the proportion of film formers based on the total mass of the coating color layer is in the range from 0.3 to 1.0% by weight.

1. a) wenigstens ein natürliches Wachs und/oder wenigstens eine Carbonsäurekomponente und
2. b) wenigstens einen Filmbildner umfasst;

wobei die Permeabilität wenigstens eines Gases durch das gestrichene Papier im Vergleich zum Basispapier reduziert ist.With the film formers according to the invention, surprisingly comparable properties with regard to the barrier effects for gases and moisture for a coated paper could be achieved even without the natural resin being omitted. According to a second aspect, the invention therefore relates to a coated paper comprising a base paper and at least one coating color layer applied directly or indirectly to the base paper, the coating color layer

1. a) at least one natural wax and/or at least one carboxylic acid component and
2. b) comprises at least one film former;

wherein the permeability of at least one gas through the coated paper is reduced compared to the base paper.

According to one embodiment, the coating layer comprises a carboxylic acid component, at least two film formers and at least one polymeric stabilizer.

In this composition, the proportion of the carboxylic acid component based on the total mass of the coating color layer can be in the range from 75 to 98 wt.%. For example, the carboxylic acid component can have a proportion of 75 wt.%, 76 wt.%, 77 wt.%, 78 wt.%, 79 wt.%, 80 wt.%, 81 wt.%, 83 wt.%, 84 wt.%, 85 wt.%, 86 wt.%, 87 wt.%, 88 wt.%, 89 wt.%, 90 wt.%, 91 wt.%, 93 wt.%, 94 wt.%, 95 wt.%, 96 wt.%, 97 wt.% or 98 wt. According to one embodiment, the proportion of the carboxylic acid component is in the range from 85 to 92 wt.% According to one embodiment, the proportion of the carboxylic acid component is in the range from 87 to 90 wt.% According to one embodiment, the proportion of the carboxylic acid component is in the range from 40 to 65 wt.%.

In the composition of the coating layer of carboxylic acid component, two film formers and optional polymeric stabilizer, the proportion of film formers based on the total mass of the coating layer can be in the range from 0.2 to 5.0% by weight. For example, the film formers can have a proportion of 0.2% by weight, 0.4% by weight, 0.6% by weight, 0.8% by weight, 1.0% by weight, 1.2 wt.%, 1.4 wt.%, 1.6 wt.%, 1.8 wt.%, 2.0 wt.%, 2.4 wt.%, 2.8 wt. -%, 3.0% by weight, 3.4% by weight, 3.8% by weight, 4.0% by weight, 4.4% by weight, 4.8% by weight , 5.0% by weight. exhibit. According to one embodiment, the proportion of film formers based on the total mass of the coating color layer is in the range from 0.3 to 2.0% by weight. According to one embodiment, the proportion of film formers based on the total mass of the coating color layer is in the range from 0.3 to 1.0% by weight.

In the composition of the coating layer of carboxylic acid component, natural resin and polymeric stabilizer, the proportion of the polymeric stabilizer based on the total mass of the coating layer can be less than 30 wt.%. For example, the polymeric stabilizer can have a proportion of 0.1 wt.%, 0.5 wt.%, 1 wt.%, 1.5 wt.%, 2.0 wt.%, 3 wt.%, 4 wt.%, 5 wt.%, 6 wt.%, 7 wt.%, 8 wt.%, 9 wt.%, 10 wt.%, 12 wt.%, 14 wt.%, 16 wt.%, 18 wt.%, 20 wt.%, 22 wt.%, 24 wt.%, 26 wt.% or 28 wt.%. In comparison to the barrier layers with natural resin, it is advantageous if the proportion of the polymeric stabilizer is somewhat higher. According to one embodiment, the proportion of the polymeric stabilizer based on the total mass of the coating layer is below 20% by weight. According to one embodiment, the proportion of the polymeric stabilizer based on the total mass of the coating layer is in the range from 5 to 15% by weight. According to one embodiment, the proportion of the polymeric stabilizer based on the total mass of the coating layer is in the range from 7 to 13% by weight.

According to an embodiment of the coated paper according to the first aspect, it is a ternary coating layer, i.e. a coating layer which comprises at least two natural waxes or at least one natural wax and a saturated fatty acid and at least one natural resin. In the ternary systems according to the invention, the proportion of the polymeric stabilizer can be further reduced. Furthermore, layers that can be painted over can be produced directly. Through variable composition The coating layer can be traded depending on the availability of the individual components while maintaining the same barrier performance (WVTR). Finally, the ternary coating color layers also have a grease tightness.

According to an embodiment of the coated paper according to the first aspect, the coating layer comprises two natural waxes, a natural resin and optionally a polymeric stabilizer. In this composition, the proportion of natural waxes based on the total mass of the coating color layer can be in the range from 10 to 80% by weight. For example, the carboxylic acid component can have a proportion of 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight % by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight or 80% by weight. According to one embodiment, the proportion of natural wax is in the range from 15 to 60% by weight. According to one embodiment, the proportion of natural waxes is in the range from 25 to 55% by weight. According to one embodiment, the proportion of natural wax is in the range of 35 to 55% by weight. According to one embodiment, the proportion of natural wax is in the range of 40 to 50% by weight.

In the composition of the coating color layer of two natural waxes, natural resin and optionally polymeric stabilizer, the proportion of natural resin based on the total mass of the coating color layer can be in the range of 20 to 90 wt.%. For example, the natural resin can have a proportion of 20 wt.%, 25 wt.%, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 60 wt.%, 65 wt.%, 70 wt.%, 75 wt.%, 80 wt.%, 85 wt.% or 90 wt. According to one embodiment, the proportion of natural resin based on the total mass of the coating color layer is in the range of 30 to 85 wt.%. According to one embodiment, the proportion of natural resin based on the total mass of the coating color layer is in the range of 40 to 70 wt.%. According to one embodiment, the proportion of natural resin based on the total mass of the coating layer is in the range of 45 to 60 wt.%.

In the composition of the coating layer of two natural waxes, natural resin and polymeric stabilizer, the proportion of the polymeric stabilizer based on the total mass of the coating layer can be below 30% by weight. For example, the polymeric stabilizer can have a proportion of 0.1% by weight, 0.5% by weight, 1% by weight, 1.5% by weight, 2.0% by weight, 3% by weight , 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, 12% by weight, 14% by weight %, 16% by weight, 18% by weight, 20% by weight, 22% by weight, 24% by weight, 26% by weight or 28% by weight. According to one embodiment, the proportion of the polymeric stabilizer based on the total mass of the coating layer is below 20% by weight. According to one embodiment, the proportion of the polymeric stabilizer based on the total mass of the coating color layer is in the range from 1 to 15% by weight. According to one embodiment, the proportion of the polymeric stabilizer, based on the total mass of the coating layer, is in the range from 2 to 10% by weight.

According to one embodiment, the ternary coating layer comprises a carboxylic acid component, a natural wax, a natural resin and optionally a polymeric stabilizer. In this composition, the proportion of the carboxylic acid component based on the total mass of the coating color layer can preferably be in the range from 5 to 85% by weight. For example, the carboxylic acid component can have a proportion of 5% by weight, 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 60 wt.%, 65 wt.%, 70 wt.%, 75 wt.%, 80 wt. -% or 85% by weight. According to one embodiment, the proportion of the carboxylic acid component is in the range from 55 to 75% by weight. According to one embodiment, the proportion of the carboxylic acid component is in the range from 15 to 70% by weight. According to one embodiment, the proportion of the carboxylic acid component is in the range from 25 to 65% by weight. According to one embodiment, the proportion of the carboxylic acid component is in the range from 30 to 40% by weight.

In this composition, the proportion of natural wax based on the total mass of the coating color layer can be in the range of 15 to 95 wt.%. For example, the carboxylic acid component can have a proportion of 15 wt.%, 20 wt.%, 25 wt.%, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 60 wt.%, 65 wt.%, 70 wt.%, 75 wt.%, 80 wt.%, 85 wt.%, 90 wt.% or 95 wt. According to one embodiment, the proportion of natural wax is in the range of 30 to 95 wt.% According to one embodiment, the proportion of natural wax is in the range of 40 to 90 wt.% According to one embodiment, the proportion of natural wax is in the range of 50 to 85 wt.% According to one embodiment, the proportion of natural wax is in the range of 60 to 80 wt.%

In the composition of the coating layer of carboxylic acid component, natural wax, natural resin and optionally polymeric stabilizer, the proportion of natural resin based on the total mass of the coating layer can be in the range from 5 to 70% by weight. For example, the natural resin can have a proportion of 5% by weight, 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight. -%, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight or 70% by weight. According to one embodiment, the proportion of natural resin based on the total mass of the coating color layer is in the range from 20 to 60% by weight. According to one embodiment, the proportion of natural resin based on the total mass of the coating color layer is in the range from 25 to 55% by weight. According to one embodiment, the proportion of natural resin based on the total mass of the coating color layer is in the range from 30 to 50% by weight.

In the composition of the coating layer of carboxylic acid component, natural wax, natural resin and polymeric stabilizer, the proportion of the polymeric stabilizer based on the total mass of the coating layer can be below 30% by weight. For example, the polymeric stabilizer can have a proportion of 0.1% by weight, 0.5% by weight, 1% by weight, 1.5% by weight, 2.0% by weight, 3% by weight , 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, 12% by weight, 14% by weight %, 16% by weight, 18% by weight, 20% by weight, 22% by weight, 24% by weight, 26% by weight or 28% by weight. According to one embodiment, the proportion of the polymeric stabilizer based on the total mass of the coating layer is below 20% by weight. According to one embodiment, the proportion of the polymeric stabilizer, based on the total mass of the coating layer, is in the range from 1 to 15% by weight. According to one embodiment, the proportion of the polymeric stabilizer, based on the total mass of the coating layer, is in the range from 2 to 10% by weight.

The coating color layer in the coated paper can have a basis weight in the range from 2 to 30 g·m ^-2 . For example, the basis weight can be 2 g·m ^-2 , 4 g·m ^-2 , 5 g·m ^-2 , 6 g·m ^-2 , 8 g·m ^-2 , 10 g·m ^-2 , 12 g·m ^-2 , 14 g·m ^-2 , 15 g·m ^-2 , 16 g·m ^-2 , 18 g·m ^-2 , 20 g·m -2 , 22 g·m ^-2 , 24 g· ^{m -2 ,} 25 g·m ^-2 , 26 g·m ^-2 , 28 g·m ^-2 or 30 g·m ^-2 . According to one embodiment, the coating color layer has a basis weight in the range from 2 to 30 g·m ^-2 . According to one embodiment, the coating color layer has a basis weight in the range of 5 to 20 g·m ^-2 According to one embodiment, the coating color layer has a basis weight in the range 8 to 15 g·m ^-2 .

The coated paper is biodegradable due to the materials present in the coating layer. "Biodegradability" refers to the ability of organic chemicals to be broken down biologically, i.e. by living organisms or their enzymes. Ideally, this chemical metabolism proceeds completely up to mineralization, but can also stop with transformation products that are stable against degradation. The OECD guidelines for testing chemicals, which are also used in the context of chemical approval, are generally accepted. The tests in the OECD test series 301 (A-F) demonstrate rapid and complete biological degradation (ready biodegradability) under aerobic conditions. Different test methods are available for readily or poorly soluble substances as well as for volatile substances. Biodegradable" or "biodegradable" in the sense of the present invention refers to papers that have a biodegradability measured according to OECD 301 F of at least 40% or measured according to OECD 302 C (MITI-II test) of at least 20% and thus have an inherent or fundamental degradability. This corresponds to the limit value for OECD 302 C according to "Revised Introduction to the OECD Guidelines for testing of Chemicals, section 3, Part 1, dated 23 March 2006". From a limit value of at least 60% measured according to OECD 301 F, microcapsule walls are also referred to as rapidly biodegradable.

According to an embodiment of the coated paper according to the first or second aspect, the coated paper has a ready biodegradability according to OECD 301

In addition, the coated paper is recyclable according to the first or second aspect. Paper recycling is the dissolution and processing of waste paper, used cardboard and paperboard in paper industry plants with the aim of producing new paper, cardboard and paperboard from it. To a small extent, waste paper pulp is first produced from the recycled waste paper as pulp, which is only later used to produce new paper. The removal of printing ink or deinking (from English ink = "printing ink", "ink") is the key process in paper recycling for removing the printing ink from printed waste paper. The assessment of recyclability can be carried out, for example, using the INGEDE method 11. The coated paper according to the invention achieves a deinkability score of over 50 using the INGEDE method 11. The deinkability score is preferably over 70.

With the components of the barrier layer used according to the first or second aspect, the coated paper can be approved for direct or indirect food contact. In particular, it is suitable for approval in accordance with the guidelines of the European Food Safety Authority.

Basically, all types of paper can be used as the base paper for the coated paper according to the first or second aspect, i.e. both cardboard and paperboard or normal paper. Papers made from hardwood and softwood pulp are preferred. Papers with a low basis weight are often in demand for food packaging, as they are flexible and use less material. The coating layer according to the invention leads to a significant increase in barrier performance, particularly for such papers.

According to an embodiment of the coated paper according to the first or second aspect, the base paper has a basis weight of less than 150 g·m ^-2 The basis weight can be, for example, 150 g·m ^-2 , 145 g·m ^-2 , 140 g·m ^-2 , 135 g·m ^-2 , 130 g·m ^-2 , 125 g·m ^-2 , 120 g·m ^-2 , 115 g·m ^-2 , 110 g·m ^-2 , 105 g·m ^-2 , 100 g·m ^-2 , 95 g·m ^-2 , 90 g·m ^-2 , 85 g·m ^-2 , 80 g·m ^-2 , 75 g·m ^-2 , 70 g·m ^-2 , 65 g·m ^-2 , 60 g·m ^-2 , 55 g·m ^-2 , 50 g·m ^-2 , 45 g·m ^-2 , 40 g·m ^-2 , 35 g·m ^-2 or 30 g·m ^-2 . According to one embodiment, the basis weight is below 100 g·m ^-2 . According to one embodiment, the basis weight is below 80 g·m ^-2 . According to one embodiment, the basis weight is in the range from 50 to 80 g·m ^-2 .

The coated paper according to the first or second aspect can contain further layers in addition to the barrier layer. According to one embodiment, the coated paper contains a further layer selected from a coating color, an ink, a sealing medium and an adhesive.

The further layer can be arranged on the barrier layer, between the base paper and the barrier layer or on the side of the base paper opposite the semi-crystalline coating layer.

The barrier layer can therefore be applied directly to the base paper. In this case, the barrier layer is in direct contact with the base paper. Indirect application means that one or more layers lie between the coating color and the base paper.

Further layers can, in particular, further reduce the permeability of at least one gas through the coated paper compared to the base paper or form barriers for liquids or viscous substances such as fats, oils, hydrocarbons.

1. a) mindestens ein hydrophobes Polymer umfassen, z.B. auf Basis eines Polyacrylats, eines Styrol-/Butadien-Copolymers und/oder eines Polyolefins
2. b) mindestens ein hydrophiles Polymer umfassen, z.B. auf Basis eines Polyvinylalkohols
3. c) mindestens ein anorganisches Pigment umfassen, z.B. ein plättchenförmiges Pigment, z.B. ein Schichtsilikat wie Kaolin,
4. d) mindestens ein anorganisches Pigment und ein Bindemittel umfassen,
5. e) amorphe und kristalline Bereiche umfassen,
6. f) Stoffe enthalten oder daraus bestehen, die ausgewählt sind aus der Gruppe lipophile Stoffe, Paraffine, insbesondere Hartparaffine, Wachse, insbesondere mikrokristalline Wachse, Wachse auf Basis von pflanzlichen Ölen oder Fetten, Wachse auf Basis von tierischen Ölen oder Fetten, pflanzliche Wachse, tierische Wachse, niedermolekulare Polyolefine, Polyterpene und deren Mischungen,
7. g) den Übergang von Stoffen, insbesondere von hydrophoben Stoffen, verringern oder verhindern, z.B. von Stoffen gemäß vorstehendem Punkt e) um beispielsweise den Übergang von Stoffen aus darunterliegenden Schichten auf ein Lebensmittel, insbesondere ein fetthaltiges Lebensmittel, zu verhindern oder zu verringern,
8. h) mindestens ein Metall, z.B. Aluminium, Gold, und/oder ein Metalloxid, z.B. Aluminiumoxid, umfassen oder daraus bestehen, insbesondere eine metallisierte Schicht sein,
9. i) mindestens heiß- oder kaltsiegelbar sein,
10. j) mindestens einen Klebstoff umfassen,
11. k) mindestens ein thermoplastisches Material, insbesondere als heißsiegelbares Material, umfassen oder daraus bestehen.

A further layer can in particular:

1. a) comprise at least one hydrophobic polymer, e.g. based on a polyacrylate, a styrene/butadiene copolymer and/or a polyolefin
2. b) comprise at least one hydrophilic polymer, e.g. based on a polyvinyl alcohol
3. c) comprise at least one inorganic pigment, e.g. a platelet-shaped pigment, e.g. a layered silicate such as kaolin,
4. d) comprise at least one inorganic pigment and a binder,
5. e) comprise amorphous and crystalline regions,
6. f) contain or consist of substances selected from the group consisting of lipophilic substances, paraffins, in particular hard paraffins, waxes, in particular microcrystalline waxes, waxes based on vegetable oils or fats, waxes based on animal oils or fats, vegetable waxes, animal waxes, low molecular weight polyolefins, polyterpenes and mixtures thereof,
7. (g) reduce or prevent the transfer of substances, in particular hydrophobic substances, e.g. substances as referred to in point (e) above, for example to prevent or reduce the transfer of substances from underlying layers to a foodstuff, in particular a fatty foodstuff,
8. h) comprise or consist of at least one metal, e.g. aluminium, gold, and/or a metal oxide, e.g. aluminium oxide, in particular be a metallised layer,
9. (i) be at least heat or cold sealable,
10. j) comprise at least one adhesive,
11. k) comprise or consist of at least one thermoplastic material, in particular a heat-sealable material.

The base paper of the coated paper according to the first or second aspect may be a base paper coated on one or both sides or an uncoated base paper.

In the case of coated base paper, the surface is finished with a coating color containing a binding agent. The material used for the binding agent is coating color, the main component of which can be starch, starch derivatives, chalk, kaolin, casein or plastic dispersion. This gives the base paper a more closed, smoother and more stable surface.

However, uncoated base paper can also be surface treated and contain up to 5 g/m ² pigments.

For use as packaging in the food sector, the paper needs a certain tear resistance or breaking strength. According to one embodiment, the coated paper has a width-related breaking strength in the fiber direction in the range of 3.0 to 6.0 kN·m ^-1 . The width-related breaking force in the fiber direction can be, for example, 3.0 kN·m ^-1 , 3.2 kN·m ^-1 , 3.4 kN·m ^-1 , 3.5 kN·m ^-1 , 3.6 kN·m ^-1 , 3.8 kN·m ^-1 , 4.0 kN·m ^-1 , 4.2 kN·m ^-1 , 4.4 kN·m ^-1 , 4.5 kN·m ^-1 , 4.6 kN·m ^-1 , 4.8 kN·m ^-1 , 5.0 kN·m ^-1 , 5.2 kN·m ^-1 , 5.4 kN·m ^-1 , 5.5 kN·m ^-1 , 5.6 kN·m ^-1 , 5.8 kN·m ^-1 , 6.0 kN·m ^-1 , According to one embodiment, the width-related breaking force is Fiber direction in the range from 3.5 to 5.5 kN m ^-1 . According to one embodiment, the broad-based breaking strength in the fiber direction is in the range from 4.0 to 5.0 kN m ^-1 .

The barrier effect of the coating color layer according to the invention is achieved with a coating color layer defined according to the first aspect.

Consequently, according to a third aspect, the invention relates to a coating color for coating paper, comprising the components defined according to the first aspect and a solvent. The solvent is in particular selected from water, tetrahydrofuran (THF), ethanol, methanol and ethyl acetate. The solvent is preferably water.

production method

1. a) Herstellen einer Streichfarbe nach einem dem dritten Aspekt durch Mischen der einzelnen Komponenten ;
2. b) Bereitstellen eines Basispapiers;
3. c) Auftrag der Streichfarbe auf das Basispapier, und
4. d) Aushärtung der Streichfarbe unter Ausbildung der Streichfarbenschicht Barrierewirkung.

Various manufacturing processes can be used to produce the coated paper according to the invention. The barrier effect of the coating color layer in the coated paper, which is essential here, is achieved in particular with the process for producing the coated paper shown in the examples. Consequently, according to a fourth aspect, the invention relates to a method for producing a coated paper with a base paper and a coating layer, comprising the steps:

1. a) producing a coating color according to the third aspect by mixing the individual components;
2. b) Providing a base paper;
3. c) applying the coating color to the base paper, and
4. d) Curing of the coating color to form the coating color layer barrier effect.

According to one embodiment, the coating color is applied to the base paper, preferably by means of a curtain or doctor blade process.

The process according to the invention can be used to influence the properties of the coating layer.

In addition, the curing temperature, curing time and curing pressure have an influence on homogeneity and barrier effect.

According to one embodiment of the method, the curing temperature is in the range from 20 to 300 °C. The curing temperature can be 20 °C, 40 °C, 60 °C, 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C, 160 °C, 170 °C, 180 °C, 190 °C, 200 °C, 220 °C, 240 °C, 260 °C, 280 °C, 300 °C. According to one embodiment of the method, the curing temperature is in the range from 100 to 140°C. According to one embodiment of the method, the curing temperature is in the range of 110 to 130°C.

According to one embodiment of the method, the curing time is in the range from 10 s to 15 min. The curing time can be, for example, 10 s, 20 s, 30 s, 40 s, 50 s, 60 s, 70 s, 80 s, 90 s, 100 s , 110s, 120s, 150s, 3min, 4min, 5min, 6min, 7min, 8min, 9min, 10min, 11min, 12min, 13min, 14min, 15min. According to In one embodiment of the method, the curing time is in the range of 1 to 3 minutes.

According to one embodiment of the method, the curing pressure is in the range from 0.2 bar to 3 bar. According to one embodiment of the method, the curing pressure is in the range from 0.9 bar to 1.1 bar.

Packaging

According to a fourth aspect, the invention relates to a packaging comprising the coated paper according to the first aspect.

This can, for example, be packaging for use for food, as an insert for electronic components such as silica packets, for medical products such as rapid tests, for washing and cleaning agents, particularly in powder or tablet form.

It may also include packaging of dried foods, foods sold cold that require further preparation, packages containing foods in portion sizes for more than one person, or packages containing foods in portion sizes for one person where more than one unit is sold.

Examples of packaging that can be used are stand-up pouches, tubular bags or packaging paper. According to one embodiment, the packaging is tubular bags.

EXAMPLES

Example 1 - Raw materials and production of the coating colors and barrier papers

Carrier material

A CCK-coated paper (coating: 5 g/m ² ) made from hardwood and softwood pulp with a total basis weight of 63 g/m ² was used as the carrier material in all examples.

Preparation of raw materials

All waxes and carboxylic acid derivatives were used as aqueous dispersions, which were stabilized by the addition of polyvinyl alcohol (approx. 10 wt.%; viscosity: 6-9 mPas; 4% aqueous solution; degree of hydrolysis: 86.7-88.7 mol%).

The dry contents (DW) of the dispersion were adjusted by adding water as follows: candelilla wax (44%), carnauba wax (40%), stearic acid (25%), palmitic acid (25%).

Shellac (Swanlac® ASL 10, dewaxed and decolorized) was dissolved in ammoniacal water (TG = 25%).

Methylcellulose (MC) and hydroxypropylmethylcellulose (HPMC) were used as solids.

Polyethylene glycol (PEG) 400 was used without prior treatment.

Production of the coating colors

The solids content of the coating colors is between 23% and 40% depending on the system. No additional water was added after mixing the component dispersions. The coating colors were sieved through a sieve with a mesh size of 80 µm and degassed with a Hauschild SpeedMixer for 4 min at 30 mbar and 800 rpm.

Coating of the base papers:

The coating color (3-5 mL for DIN A4 application) was applied to the CCK-coated side of the base paper (DIN A3) at room temperature using a film applicator with doctor bars (Erichsen). The doctor bar was selected so that the desired application weight of 10 g/m ² was achieved. The specified basis weight refers to the dried layer.

After applying the paint, the papers were directly attached to standard cardboard using magnets (to avoid curling up) and dried in a circulating air oven (Memmert; setting: 50% flap, 50% fan) at a temperature of 110 °C until the barrier film was fully formed.

Example 2 - Barrier effect of comparison coating colors with one component

First, coating colors made from the individual components carboxylic acid component (fatty acid), wax and natural resin (shellac) were tested for their water vapor barrier effect.

• • Schellack in Ethanol gelöst (25 wt.%)
• • Schellack in Eisessig gelöst (25 wt.%)
• • Schellack gelöst in 5 wt.% Ammoniumbicarbonat-Lsg (25 wt.%),
• • Candellilawachs-Dispersion (26 wt. %)
• • Carnaubawachs-Dispersion (26 wt %)
• • Palmitinsäure-Dispersion (25 wt.%)
• • Stearinsäure-Dispersion (25 wt.%)

For this purpose, coating colours with the following compositions were prepared as described in Example 1:

• • Shellac dissolved in ethanol (25 wt.%)
• • Shellac dissolved in glacial acetic acid (25 wt.%)
• • Shellac dissolved in 5 wt.% ammonium bicarbonate solution (25 wt.%),
• • Candelilla wax dispersion (26 wt. %)
• • Carnauba wax dispersion (26 wt %)
• • Palmitic acid dispersion (25 wt.%)
• • Stearic acid dispersion (25 wt.%)

To produce coated papers, the coating colors were applied to the pre-coated base paper as described in Example 1. The application weight was 10 g/m ² in each case. The drying time was about 1-1.5 minutes at a temperature of about 110 °C.

The water vapor transmission rate (WVTR) was determined under tropical conditions (38 °C, 90% RH) according to DIN 53122 1 / DIN 53122 A (rel.: ISO 2528:1995, ASTM E 96). The results of this measurement are shown in Table 1. Table 1: WVTR of comparison barrier papers Coating color layers made from individual components Coating color composition WVTR in g/m ² d --- (pre-coated base paper) 990±38 shellac dissolved in ethanol (25 wt%) 239±2 dissolved in glacial acetic acid (25 wt%) 242±8 dissolved in 5 wt% ammonium bicarbonate solution (25 wt%). 201±10 wax Candelilla wax 78 ± 11 Camauba wax 90 ± 2 fatty acid Palmitic acid 68±16 Stearic acid 44 ± 0.3

A barrier paper with a coating of shellac alone shows only a low water vapor barrier effect with WVTR values of over 200 g/m ² d. The WVTR of barrier papers with layers of natural waxes and fatty acids, on the other hand, is significantly lower. However, particularly with coatings containing fatty acids, inhomogeneous film formation occurs and thus fluctuations in the WVTR across the surface of the barrier paper.

Example 3 - Characterization of binary coating colors according to the invention

3.1 Binary coating color made from shellac and candelilla wax

3.1.1. Application using a squeegee

In this series of experiments, binary coating colours made of shellac and candelilla wax were tested for their water vapor barrier effect.

For this purpose, coating colors with different proportions of shellac and candelilla wax as well as PVA (6-9 mPas (4% aqueous solution; degree of hydrolysis: 86.7-88.7 mol%) were produced according to the description in Example 1. The compositions had a ratio of Candelilla wax dispersion to shellac of 0:100, 20:80, 40:60, 60:40, 80:20 and 100:0.

To produce coated papers, the coating colors were applied to the base paper as described in Example 1. The application weight was 10 g/m ² .

In addition, the composition with a ratio of candelilla wax dispersion to shellac of 20:80 was applied with different application weights in the range from 5 to 30 g/m ² .

In the examples, drying was carried out at a constant temperature between 90 - 120 °C for a defined time. The drying time is chosen to be as short as possible, i.e. until the film is completely formed (visually recognizable by a homogeneous shine), without further tempering. Longer drying results in impregnation, which has a negative effect on the barrier effect of the coated papers. In this case, the drying time was around 1-1.5 minutes at a temperature of around 110 °C.

The water vapor transmission rate (WVTR) was determined using the cup method under tropical conditions (38 °C, 90 % RH) according to DIN 53122 1 / DIN 53122 A (rel.: ISO 2528:1995, ASTM E 96). The results are shown in the 1 and 2 shown.

The results are in the 1 and 2 shown.

By mixing shellac and the wax dispersions, the film forming and drying properties are improved when the coating color is applied to the backing paper. In addition, the binary coating color layers had an improved WVTR compared to the individual component layers at an application weight of 10 g/m ² . For the WVTR, by varying the proportions of shellac and wax, a minimum of a ratio of shellac to candelilla wax of 1:5 (20:80) could be determined. By mixing the wax dispersion with shellac, the proportion of process-related PVA can also be reduced.

The order weight also had a significant influence on the WVTR. When the application weight was reduced to 5 g/m ^{2 ,} the WVTR increased from approximately 40 g/m ² d to over 80 g/m ² d. By increasing the application weight, however, it was possible to achieve WVTR values of approximately 0 g/m ² d. The minimum WVTR was at application weights of approximately 15 g/m ² .

3.1.2. Application using curtain coating

By adding process additives known to those skilled in the art (e.g. thickeners and surfactants), a coating color according to the invention consisting of 80% candelilla wax dispersion and 20% shellac solution could be produced using the curtain coating coating process at an operating speed of the coating system of at least 200 m/min and dried. The papers obtained have a WVTR of 27.4 ± 2.0 g/m ² d.

3.1.3. Storage stability

The coated papers produced according to 3.1.2 with a coating layer consisting of candelilla wax dispersion and shellac were examined for positional stability.

The papers were tested for their water vapor barrier effect after 10, 75, 100, 150 and 200 days of storage at 23 °C and 50 % relative humidity.

The results are in 3 shown.

3.2 Binary coating colour made from shellac and stearic acid

In this series of tests, binary coating colors made from shellac and stearic acid were examined for their water vapor barrier effect.

For this purpose, coating colors with different proportions of shellac and stearic acid were prepared as described in Example 1. The exact compositions can be found in Table 2.

To produce coated papers, the coating colors were applied to the base paper as described in Example 1. The application weight was 10 g/m ² .

The drying time was about 2-2.5 minutes at a temperature of about 90 °C.

The WVTR was determined under tropical conditions (38 °C, 90% RH) according to DIN 53122 1 / DIN 53122 A (rel.: ISO 2528:1995, ASTM E 96). The results are shown in Table 2. Table 2: WVTR of binary barrier papers according to the invention Shellac (%): Stearic acid dispersion (TG = 25%) WVTR (g/m ² d) 52.1 50:50 55±6 31.8 30:70 46±5 27.2 25:75 15±1 11.1 10:90 35±3

When producing the binary coating layers from shellac and stearic acid, improved film formation and drying properties were observed compared to the individual component layers. On the other hand, the binary coating color layers had an improved WVTR compared to the individual component layers at an application weight of 10 g/m ² . It is assumed that the introduction of shellac limits the crystallization of stearic acid on the surface, thereby improving the water vapor barrier and the homogeneity of the lines. For the WVTR, by varying the proportions of shellac and stearic acid dispersion, a minimum was determined at a ratio of shellac to stearic acid of approximately 3:1 (25:75). By mixing stearic acid with shellac, the proportion of process-related PVA can also be reduced.

Example 4 - Characterization of ternary coating colors according to the invention

4.1 Ternary system made of candelilla wax, carnauba wax and shellac

In this series of experiments, ternary coating colours made from candelilla wax, carnauba wax and shellac were investigated for their water vapor barrier effect.

For this purpose, coating colors with different proportions of candelilla wax, carnauba wax and shellac as well as PVA (6-9 mPas 4% aqueous solution; degree of hydrolysis: 86.7-88.7 mol%) were produced according to the description in Example 1. The ratios of the components in the compositions can be found in Table 3.

To produce coated papers, the coating colors were applied to the base paper as described in Example 1. The application weight was 10 g/m ² .

The drying time was around 1-2 minutes at a temperature of around 110 °C.

The water vapor transmission rate (WVTR) was determined under tropical conditions (38 °C, 90% RH) according to DIN 53122 1 / DIN 53122 A (rel.: ISO 2528:1995, ASTM E 96). The results are shown in Table 3. Table 3: WVTR of ternary barrier papers according to the invention Composition of the coating color (TG = 35%) WVTR _{Trop .} in g/m ² d remark 50% shellac 25% candelilla wax 25% carnauba wax 16±1 Greaseproof 50% shellac 38.3% carnauba wax 11.7% candelilla wax 45±10 -

Barrier papers with ternary layers of shellac, candelilla wax and carnauba wax also achieve very low WVTR values of less than 20 g/m ² d at an application weight of 10 g/m ² . In addition, these ternary layers can achieve grease resistance according to the palm kernel fat test (EN ISO 53116).

4.2 Ternary system made of candelilla wax, stearic acid and shellac

In this series of experiments, ternary coating colours made from candelilla wax, stearic acid and shellac were tested for their water vapor barrier effect.

For this purpose, coating colors with different proportions of candelilla wax, stearic acid and shellac were produced as described in Example 1. The ratios of the components in the compositions can be found in Tables 4 and 5.

To produce coated papers, the coating colors were applied to the base paper as described in Example 1. The coating weight was a constant 10 g/m ² . The drying time was about 1-2 minutes at a temperature of about 120 °C.

The water vapor transmission rate (WVTR) was determined under tropical conditions (38 °C, 90% RH) according to DIN 53122 1 / DIN 53122 A (rel.: ISO 2528:1995, ASTM E 96). The results are shown in Tables 4 and 5. Table 4: WVTR of ternary barrier papers according to the invention with high shellac concentration Composition of the coating color WVTR in g/m ² d 50% shellac 38.3% candelilla wax 11.7% stearic acid (TG = 32%) 42±1 50% shellac 25% candelilla wax 25% stearic acid (TG = 29%) 29 ± 12 50% shellac 19.2% candelilla wax 30.8% stearic acid (TG = 28%) 29±4 50% shellac 17.8% candelilla wax 32.2% stearic acid (TG = 27%) 46±8 50% shellac 11.6% candelilla wax 38.4% stearic acid (TG = 26%) 10±40 Table 5: WVTR of ternary barrier papers according to the invention with low shellac concentration Composition of the coating color WVTR _{Trop .} in g/m ² d remark 10% shellac 67.2% candelilla wax 22.8% stearic acid (TG = 38%) 23±1 - 10% shellac 45% candelilla wax 45% stearic acid (TG = 33%) 22±2 - 10% Shellac 31.6% Candelilla Wax 58.4% Stearic Acid - (TG = 31%) 30±3 - 10% shellac 22.7% candelilla wax 67.3% stearic acid (TG = 29%) 19±4 Can be painted over with aqueous dispersion 10% shellac 25% candelilla wax 65% stearic acid (TG = 30%) 43±9 Can be painted over with aqueous dispersion

Barrier papers with ternary layers of shellac, candelilla wax and steraic acid also achieve very low WVTR values of less than 20 g/m ² d with an application weight of 10 g/m ² . In addition, some compositions of the layers, in particular with a high proportion of shellac and/or stearic acid, lead to the coating color layer being easy to paint over with water-based barriers, such as oxygen barriers or sealing media. Although shellac as individual components a poor water vapor barrier with high WVTR values, WVTR values of less than 20 g/m ² d could be achieved in the ternary system even with a proportion of 50% shellac.

Example 5: Characterization of coating colors according to the invention with film formers

5. 1 Variation of the film former composition

In this series of experiments, the influence of film formers on the water vapor barrier effect of stearic acid coating colors was investigated.

For this purpose, coating colours with the basic composition according to Table 6 were prepared according to the description in Example 1: Table 6: Basic composition Sample weight in g Composition (otro %) 0.06 g MC 0.4% Methylcellulose (MC) 0.026 g HPMC 0.17% hydroxypropylmethylcellulose (HPMC) 60 g SA = 89% stearic acid / 11 % PVA (dispersion with TG = 25) 88.2% stearic acid (25% by weight) 10.9% PVDF 0.05g PEG400 0.33% PEG400

• HPMC1: Viskosität (2% aq.) 3 mPas; DS = 1,9; MS = 0,23
• HPMC2: Viskosität (2% aq.) 50 mPas; DS = 1,9; MS = 0,23
• HPMC3: Viskosität (2% aq.) 50 mPas; DS = 1,8; MS = 0,13
• MC1: Viskosität (2% aq.) 4 mPas; DS = 1,8
• MC2: Viskosität (2% aq.) 25 mPas; DS = 1,8
• MC3: Viskosität (2% aq.) 400 mPas; DS = 1,8

The MC and HPMC used differ as follows:.

• HPMC1: Viscosity (2% aq.) 3 mPas; DS = 1.9; MS = 0.23
• HPMC2: Viscosity (2% aq.) 50 mPas; DS = 1.9; MS = 0.23
• HPMC3: Viscosity (2% aq.) 50 mPas; DS = 1.8; MS = 0.13
• MC1: Viscosity (2% aq.) 4 mPas; DS = 1.8
• MC2: Viscosity (2% aq.) 25 mPas; DS = 1.8
• MC3: Viscosity (2% aq.) 400 mPas; DS = 1.8

To produce coated papers, the coating colors were applied to the base paper as described in Example 1. The application weight was 10 g/m ² . The drying time was about 1-1.5 minutes at a temperature of about 110 °C.

The water vapor transmission rate (WVTR) was determined under tropical conditions (38 °C, 90 % RH) according to DIN 53122 1 / DIN 53122 A (rel.: ISO 2528:1995, ASTM E 96). The results are shown in Table 7. Table 7: Influence of film formers on the WVTR WVTR values in g/m ² d MC1 MC2 MC3 HPMC1 31 ± 5 53 ± 9 57 ± 16 HPMC2 14 ± 1 36 ± 14 50 ± 7 HPMC3 20 ± 5 13 ± 2 11 ± 1

It was shown that the WVTR of the barrier papers decreases with increasing viscosity of the MC and HPMC used.

5.2 Variation of the fatty acid component

The experiment corresponds to that described under 5.1. Instead of stearic acid, palmitic acid or mixtures of the two fatty acids are used. Table 8: Coating color compositions WVTR values in g/m ² d Palmitic acid 33±23 50:50 palmitic:stearin 16±2 33:66 palmitic:stearin 22±6 Stearic acid 11±1

With regard to further advantageous embodiments of the device according to the invention, reference is made to the general part of the description and to the appended claims in order to avoid repetition.

Finally, it should be expressly pointed out that the embodiments of the products according to the invention described above serve only to explain the claimed teaching, but do not limit it.

QUOTES INCLUDED IN THE DESCRIPTION

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

Cited patent literature

• JP 2006096981 A [0007]
• WO 2020152292 A1 [0008]
• WO 2020011824 A1 [0009]
• US 9902815 B2 [0010]

Cited non-patent literature

• DIN53122-1 [0008, 0009]

Claims (23)

Coated paper comprising a base paper and at least one coating color layer applied directly or indirectly to the base paper, wherein the coating color layer comprises a) at least one natural wax and/or at least one carboxylic acid component and b) at least one natural resin; wherein the permeability of at least one gas through the coated paper is reduced in comparison to the base paper. Coated paper after Claim 1 , whereby the natural resin is selected from shellac, turpentine, balsam, gum varnish, rosin, sandarac, mastic. Coated paper comprising a base paper and at least one coating layer applied directly or indirectly to the base paper, the coating layer a) at least one natural wax and/or at least one carboxylic acid component and b) comprises at least one film former; wherein the permeability of at least one gas through the coated paper is reduced compared to the base paper. Coated paper after Claim 1 or 2 , wherein the coating layer additionally comprises a polymeric stabilizer. Coated paper according to one of the preceding claims, wherein the permeability of at least one gas is lower than the permeability of a coated paper with the same base paper and each having a coating layer made of the natural wax or the saturated fatty acid and a coating layer made of the natural resin. Coated paper according to one of the preceding claims, with a water vapor permeability (WVTR) of not more than 50 g m ^-2 d ^-1 , preferably not more than 20 g m ^-2 d ^-1 measured at 38 ° C and above 90% humidity and with a surface weight of the coating color of 10 ± 1 g m ^-2 . Coated paper according to one of the preceding claims, wherein the carboxylic acid component is selected from fatty acids, hydroxy fatty acids or dicarboxylic acids or their esters, amides or salts. Coated paper after Claim 7 , wherein the fatty acids are saturated or unsaturated fatty acids having 12 to 40 carbon atoms, preferably fatty acids having 16 to 18 carbon atoms and 0 or 1 double bond, particularly preferably selected from palmitic acid, margaric acid, stearic acid, in particular the carboxylic acid component is stearic acid or its amide. Coated paper according to one of the preceding claims, wherein the natural wax is selected from carnauba wax, candelilla wax, beeswax, China wax and Japan wax. Coated paper according to one of the Claims 3 until 9 , wherein the polymeric stabilizer is a cross-linked or uncross-linked stabilizer selected from the group consisting of polyvinyl alcohol, starch, carboxyl group-modified polyvinyl alcohol, ethylene-vinyl alcohol copolymer, a combination of polyvinyl alcohol and ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, silanol group-modified polyvinyl alcohol, diacetone-modified polyvinyl alcohol, modified polyethylene glycol, unmodified polyethylene glycol, α-isodecyl- cj-hydroxy-poly(oxy-1,2-ethanediyl), styrene-butadiene latex, styrene-acrylate polymers, acrylic copolymers, carboxyl group-modified polyvinyl alcohol, ethylene-vinyl alcohol copolymer, a combination of polyvinyl alcohol and ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, silanol group-modified polyvinyl alcohol, diacetone-modified polyvinyl alcohol, modified Polyethylene glycol, unmodified polyethylene glycol, α-isodecyl- cj-hydroxy-poly(oxy-1,2-ethanediyl), styrene-butadiene latex, styrene-acrylate polymers, acrylic copolymers and mixtures thereof and mixtures thereof. Coated paper according to one of the Claims 3 until 10 , wherein the coating layer comprises a carboxylic acid component, a natural resin and optionally a polymeric stabilizer, wherein: a) the proportion of the carboxylic acid component based on the total mass of the coating layer is in the range from 25 to 75 wt. %, preferably in the range from 30 to 75 wt. %, particularly preferably in the range from 40 to 65 wt. %, b) the proportion of the natural resin based on the total mass of the coating layer is in the range from 20 to 60 wt.%, preferably in the range from 25 to 55 wt.%, particularly preferably in the range from 30 to 50 wt.%; and/or b) the proportion of the polymeric stabilizer based on the total mass of the coating color layer is below 20 wt.%, preferably in the range from 1 to 15 wt.%, particularly preferably in the range from 2 to 10 wt.%. Coated paper according to one of the Claims 3 until 10 , wherein the coating layer comprises a natural wax, a natural resin and optionally a polymeric stabilizer, wherein: a) the proportion of the natural wax based on the total mass of the coating layer is in the range from 40 to 95% by weight, preferably in the range from 60 to 90 % by weight, particularly preferably in the range from 50 to 85% by weight, very particularly preferably in the range from 60 to 80% by weight; b) the proportion of natural resin based on the total mass of the coating color layer is in the range from 5 to 60% by weight, preferably in the range from 10 to 40% by weight, particularly preferably in the range from 20 to 40% by weight; and/or b) the proportion of the polymeric stabilizer, based on the total mass of the coating color layer, is below 20% by weight, preferably in the range from 1 to 15% by weight, particularly preferably in the range from 2 to 10% by weight. Coated paper according to one of the present claims, wherein the coating color layer comprises at least one film former selected from methylcellulose, hydroxymethylcellulose, carboxymethylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, wherein the coating color layer preferably comprises two film formers, wherein the film formers are methylcellulose, hydroxymethylcellulose. Coated paper after Claim 13 , wherein the coating layer comprises a carboxylic acid component, two film formers and at least one polymeric stabilizer, wherein: a) the proportion of carboxylic acid component based on the total mass of the coating layer is in the range from 75 to 98% by weight, preferably in the range from 80 to 95% by weight. %, particularly preferably in the range from 85 to 92% by weight, very particularly preferably in the range from 87 to 90% by weight; b) the proportion of film formers based on the total mass of the coating color layer is in the range from 0.2 to 5.0% by weight, preferably in the range from 0.3 to 2.0% by weight, particularly preferably in the range from 0, 3 to 1.0% by weight; very particularly preferably in the range of and/or b) the proportion of the polymeric stabilizer based on the total mass of the coating color layer is below 20% by weight, preferably in the range from 5 to 15% by weight, particularly preferably in the range from 7 to 13 % by weight. Coated paper according to one of the Claims 3 until 10 , wherein the coating layer comprises a) at least two natural waxes or one natural wax and at least one saturated fatty acid and b) at least one natural resin. Coated paper after Claim 15 , wherein the coating layer comprises two natural waxes, a natural resin and optionally a polymeric stabilizer, wherein: a) the proportion of natural waxes based on the total mass of the coating layer is in the range from 15 to 60% by weight, preferably in the range from 25 to 55 % by weight, particularly preferably in the range from 35 to 55% by weight, very particularly preferably in the range from 40 to 50% by weight; b) the proportion of natural resin based on the total mass of the coating color layer is in the range from 30 to 85% by weight, preferably in the range from 40 to 70% by weight, particularly preferably in the range from 45 to 60% by weight; and/or b) the proportion of the polymeric stabilizer, based on the total mass of the coating color layer, is below 20% by weight, preferably in the range from 1 to 15% by weight, particularly preferably in the range from 2 to 10% by weight. Coated paper after Claim 16 , comprising a natural wax, a carboxylic acid component, a natural resin and optionally a polymeric stabilizer, where: a) the proportion of the natural wax based on the total mass of the coating color layer is in the range from 2 to 70% by weight, preferably in the range from 5 to 35 % by weight, particularly preferably in the range from 5 to 25% by weight, very particularly preferably in the range from 7 to 20% by weight; b) the proportion of the carboxylic acid component based on the total mass of the coating color layer is in the range from 5 to 75% by weight, preferably in the range from 15 to 70% by weight, particularly preferably in the range from 25 to 65% by weight, very particularly is preferably in the range of 30 to 40% by weight; and/or c) the proportion of natural resin based on the total mass of the coating color layer is in the range from 5 to 65% by weight, preferably in the range from 7 to 60% by weight, particularly preferably in the range from 8 to 55% by weight. lies; and or d) the proportion of the polymeric stabilizer, based on the total mass of the coating color layer, is below 20% by weight, preferably in the range from 1 to 15% by weight, particularly preferably in the range from 2 to 10% by weight. Coated paper according to one of the preceding claims, with a basis weight of the coating color layer in the range from 2 to 30 g m ^-2 , preferably in the range from 5 to 20 g m ^-2, particularly in the range from 8 to 15 g m ^-2 . Coated paper according to one of the preceding claims, wherein the coated paper has at least one of the following features: • the coated paper is biodegradable, in particular it has a ready biodegradability according to OECD 301; • the coated paper is recyclable; and • the coated paper can be approved for direct or indirect food contact, in particular according to the guidelines of the European Food Safety Authority. Coating paint for coating papers, containing the components defined according to one of the Claims 1 until 20 and a solvent selected from water, tetrahydrofuran (THF) and ethanol, the solvent is preferably water. A process for producing a coated paper with a base paper and a coating layer, comprising the steps of: a) producing a coating layer according to Claim 20 by melt dispersion, high pressure dispersion, or spray drying and subsequent mechanical dispersion of the components; b) providing a base paper; c) applying the coating color to the base paper, preferably by means of a curtain or doctor blade process; and d) curing the coating color to form the coating color layer. Packaging comprising the coated paper according to one of the Claims 1 until 19 . Packaging according to Claim 22 , for use in food, as an additive for electronic components such as silica packets, for medical products such as rapid tests, for washing and cleaning agents, particularly in powder or tablet form.

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