Substrate having antimicrobial properties

Abstract

The invention relates to a substrate (10) having antimicrobial properties and consisting at least in part of a cellulose material, in particular of paper, cardboard, and / or paperboard, wherein the substrate (10) comprises at least one coating (14) and / or impregnation with an antimicrobial agent (12) selected from the group consisting of benzalkonium chloride, didecyldimethylammonium chloride, and mixtures thereof.

Description

[0001] Substrate with antimicrobial properties

[0002] The present invention relates to a substrate with antimicrobial properties, which consists at least partially of a cellulose material, in particular of paper, cardboard and / or corrugated board.

[0003] In recent years, extensive research programs have been conducted to develop antimicrobial, cellulose fiber-containing substrates such as paper, cardboard, or corrugated board. These substrates are designed to inhibit the growth of bacteria and other microorganisms on their surface, which is particularly desirable in applications where hygiene is paramount, such as substrates that come into direct contact with people, food packaging, or packaging for medical products. Antimicrobial substrates can be produced in various ways. For example, cellulose fibers are often coated with antimicrobial agents containing silver nanoparticles, copper ions, or other antimicrobial substances. These coatings then inhibit the growth of bacteria and other microorganisms on the substrate's surface.

[0004] Furthermore, chemical modifications of the cellulose structure can also be carried out to achieve antimicrobial properties. Certain groups or compounds can be introduced into the cellulose to inhibit the growth of microorganisms.

[0005] A disadvantage of the known antimicrobial substrates is that they either have relatively low efficacy or are very expensive and complex to produce.

[0006] It is therefore an object of the present invention to create an antimicrobial substrate that is easier to manufacture and has an improved antimicrobial effect.

[0007] The problem is solved according to the invention by a substrate having the features of claim 1. Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims.

[0008] A first aspect of the invention relates to a substrate with antimicrobial properties, which consists at least partially of a cellulose material, in particular paper, cardboard, and / or corrugated board. According to the invention, simpler production with simultaneously increased effectiveness is made possible by the fact that the substrate has at least one coating and / or impregnation with an antimicrobial active ingredient from the group consisting of benzalkonium chloride, didecyldimethylammonium chloride, and mixtures thereof. Benzalkonium chloride is a compound or a mixture of compounds with the general formula I, where n is an even number from the series 8, 10, 12, 14, 16, and 18.

[0009] ( I ) •

[0010] The molecular formula can therefore also be given as C9H13C1NR (with R = C8H17 to C18H37). Didecyldimethylammonium chloride is also a quaternary ammonium compound and has the formula II:

[0011]

[0012] ( II ) or the sum formula C22H48C1N .

[0013] In both formulas I and II, other suitable anions may be used instead of chloride.

[0014] The invention is based on the finding that the aforementioned, readily available compounds, individually or in any mixture, are ideally suited as antimicrobial agents for cellulose-based substrates. Cellulose-based substrates can be treated with the agent in a variety of ways, with the cellulose-based substrates being, in particular, paper, cardboard, or corrugated board-based substrates. Within the scope of this disclosure, the substrates have a basis weight of up to 150 g / m². 2 paper, 150 g / m² 2 up to 500 g / m² 2 cardboard and from 500 g / m² 2The substrate is made of cardboard. In general, according to the invention, the substrate can have one or more coatings containing the active ingredient. Alternatively or additionally, the substrate can be impregnated with the active ingredient. Due to the fiber structure and absorption capacity of cellulose materials, impregnation, in particular, represents a simple and especially reliable way to permanently provide the substrate with antimicrobial properties. Unlike a coating, impregnation provides antimicrobial protection to the entire substrate and not just its surface. Regardless of whether it has one or more coatings containing the active ingredient, the substrate can have layer systems with further layers and can be uncoated or coated on one or both sides. Preferably, a coating containing the active ingredient is located on the outside to ensure high efficacy.In principle, the expressions "ein" or "eine" are to be considered indefinite articles within the context of this disclosure. This means that, unless explicitly stated otherwise, they are always to be understood as "at least one" or "at least one". Conversely, they can also be interpreted as "only one" or "only one", provided the context allows for this.

[0015] In an advantageous embodiment of the invention, the at least one coating is applied to the substrate by means of a process from the group consisting of offset printing, digital printing, flexographic printing, screen printing, gravure printing, varnishing, curtain coating, laminating, cellophane wrapping, UV coating, and embossing. This enables a particularly flexible coating of different substrates. Existing coating equipment can also be advantageously used for the antimicrobial treatment of the substrate.

[0016] Further advantages arise from the fact that, to produce at least one coating, one or more of the following from the group—colors, in particular coating and / or printing inks, varnishes, in particular clear varnishes and / or effect varnishes, binders, in particular adhesives, inks, water- or solvent-based coating materials, films, UV-curable coatings, chemically curable coatings, embossing foils, transfer films, and adhesive coatings—are applied to the substrate and optionally dried and / or cured. This also represents a simple and cost-effective way to make existing coatings on the substrate antimicrobial by adding the active ingredient. Alternatively, the coating containing the active ingredient can be applied separately, and the active ingredient can be incorporated into all common application methods. Preferably, the coating is water-based.an aqueous dispersion, since the solubility of the active ingredient is higher here due to its ionic structure than in non-aqueous systems.

[0017] Further advantages arise from the fact that the proportion of the active ingredient in the coating is up to 50 wt.%, particularly between 1 wt.% and 10 wt.%. This allows the effectiveness and duration of the antimicrobial treatment to be optimally adapted to the respective application without impairing the adhesion of the coating.

[0018] In a further advantageous embodiment of the invention, the impregnation is produced by first dissolving the active ingredient in an ethanol-containing solvent, after which the substrate is impregnated and / or sprayed and / or printed with the solvent containing the active ingredient. This allows the impregnation to be optimally tailored to the type and intended use of the substrate. Furthermore, the ethanol component of the solvent, which also has antimicrobial properties, advantageously ensures that any bacterial contamination on the substrate is eliminated during the impregnation process. Another advantage of the ethanol component is that the solvent evaporates particularly quickly and without leaving any residue after application. Therefore, even very thin paper substrates, such as mouthpiece coating papers, can be treated with an antimicrobial finish without creasing or wrinkling.In addition to ethanol and the active ingredient, the solvent can contain water. Conversely, the solvent can also be largely anhydrous and instead have a high ethanol content of 70% by volume or more. Generally, it is also possible for other ingredients to be dissolved and / or suspended or dispersed in the solvent. In further development, it has proven advantageous if the solvent contains at least 5% by volume, and in particular between 10% and 20% by volume or more, of ethanol by volume. This allows the formulation of the solution used for coating or impregnation to be optimally adapted to the specific amount of benzalkonium chloride and / or didecyldimethylammonium chloride present, as well as to the desired drying rate.

[0019] Alternatively or additionally, the solvent is intended to contain at least 5% by weight, and in particular between 10% and 30% by weight, of dissolved and / or dispersed active ingredient. In other words, the solution used for coating and / or impregnation contains at least 5% by weight of active ingredient, as well as corresponding amounts of solvent (quantum satis), based on its total weight. This also allows the solution to be optimally adapted to the respective substrate. The higher the active ingredient content of the solution, the greater the microbicidal effect, the less volume generally needs to be used to introduce a specific amount of active ingredient per unit area, and the less solvent, i.e., in particular ethanol and / or water, needs to be removed after impregnation. In typical application scenarios, a concentration of approximately 10% by weight of the active ingredient is generally sufficient.A concentration of approximately 20% by weight achieves a kill rate of around 99% of the bacteria present, while a concentration of about 20% by weight kills approximately 99.9% of all bacteria present. Conversely, however, excessively high concentrations of the active ingredient can lead to local precipitation.

[0020] Further advantages arise from the fact that the cellulose material consists of virgin fibers or at least partially of recycled fibers. This allows for optimal adaptation of the cellulose material to its intended application and to locally available raw materials. Furthermore, the cellulose material can be bleached or unbleached.

[0021] Another way to adapt the antimicrobial properties of the substrate to its intended use is achieved by coating the substrate at least partially on one or both sides. In other words, the substrate can be coated completely or only locally with the coating containing the active ingredient, and the coating can also be applied to only one side or to both sides of the substrate. Preferably, the coating is applied at least to the side of the substrate where the probability of contamination with microorganisms is highest.

[0022] In a further advantageous embodiment of the invention, the substrate is designed as mouthpiece coating paper (also referred to as "tipping paper" or simply "tipping") for filters of tobacco products, as parchment paper, for example for sausage and meat products, for cheese, or for baked goods or confectionery, inner liner (for example for cigarette packs, preferably 50 to 100 g / m2), molded material, molded pulp, whole wrapper, liner sheet, outer wrapper (big packs and / or single packs), translucent paper, heat-not-burn product, cut sheet and / or as packaging, in particular food packaging, hinge-lid packaging or pharmaceutical packaging. “Heat-not-burn products” refer to products for systems in which tobacco is heated with a heating system, but not burned as in conventional tobacco products.In this way, the advantageous properties of the substrate can be realized for various cellulose-based products in which antimicrobial contamination would be particularly problematic or would be highly likely to occur without countermeasures. Each of the aforementioned antimicrobially equipped packaging types or product types possesses an independent inventive quality.

[0023] A second aspect of the invention relates to a mouthpiece coating paper comprising or consisting of a substrate according to the first aspect of the invention. The resulting features and their advantages can be found in the descriptions of the first aspect of the invention.

[0024] A third aspect of the invention relates to a blank, in particular for packaging, comprising or consisting of a substrate according to the first aspect of the invention. The resulting features and their advantages can be found in the descriptions of the first aspect of the invention.

[0025] Another aspect of the invention relates to packaging, in particular food packaging or pharmaceutical packaging, which consists at least partially of a substrate according to the first aspect of the invention and / or of a blank according to the third aspect of the invention. The resulting features and their advantages can be found in the descriptions of the first and third aspects of the invention. The packaging can, for example, be a folding box or a cardboard box. Folding boxes and cardboard boxes are packaging made of cardboard or corrugated board used for the transport, storage, and sale of products. Folding boxes are flat, prefabricated pieces of cardboard that are folded and shaped at the edges to form a box. They typically consist of a single sheet of cardboard and can be manufactured in various sizes and shapes.Folding boxes can be used for products such as food, medicine, cosmetics, electronics, and household goods. They offer a cost-effective and versatile packaging solution that is easy to print and design. Cardboard boxes are larger, sturdier packages made from multiple layers of cardboard or corrugated board. They are primarily used for transporting and storing heavier or more fragile products that require extra protection. Cardboard boxes can take various forms, including cartons, boxes, containers, and trays. They are generally more robust than folding boxes and can be used for shipping goods in bulk or for storing products in industrial and commercial environments.Folding boxes and cardboard boxes are therefore important packaging materials that help to transport, store and present products safely, with the antimicrobial finish according to the invention ensuring a particularly high and long-lasting protection against microbial contamination.

[0026] Other aspects, each possessing its own independent inventive content, concern the following points:

[0027] A method for impregnating a substrate for mouthpiece coating paper, wherein the substrate consists at least partially of a cellulose material, in particular paper, and wherein the method comprises at least the following steps:

[0028] - Providing a solvent comprising ethanol and an antimicrobial agent from the group consisting of benzalkonium chloride, didecyldimethylammonium chloride and mixtures thereof; and

[0029] - Impregnating the substrate with the active ingredient by applying the solvent containing the active ingredient to the substrate.

[0030] Preferably, the solvent contains at least 5 vol.%, in particular between 10 vol.% and 20 vol.% or more ethanol, and / or wherein the solvent contains at least 5 wt.%, in particular between 10 wt.% and 30 wt.% of the active ingredient, and / or wherein the solvent contains water.

[0031] Preferably, the substrate is impregnated by impregnating it with the solvent and / or spraying and / or printing. Preferably, the substrate is dried after impregnation.

[0032] Further properties and features of the invention will become apparent from the claims, the figures, and the description of the figures. Both the features and combinations of features mentioned above in the description, as well as the features and combinations of features shown in the description of the figures and / or those shown solely in the figures, are applicable not only in the specified combinations but also in other combinations without departing from the scope of the invention. Therefore, embodiments of the invention that are not explicitly shown or explained in the figures but that result from separate combinations of features of the explained embodiments and are feasible are also included. Likewise, embodiments and combinations of features that do not exhibit all the features of an originally formulated independent claim are to be considered patently disclosed.Furthermore, embodiments and combinations of features that go beyond or deviate from the combinations of features set out in the cross-references of the claims are to be considered open to interpretation. This shows:

[0033] Fig. 1 a schematic sectional view of an impregnated mouthpiece coating paper;

[0034] Fig. 2 shows a schematic sectional view of a double-sided coated cardboard substrate; and

[0035] Fig. 3 shows a schematic sectional view of an impregnated, coated and coated paper.

[0036] Fig. 1 shows a schematic sectional view of an impregnated substrate 10, which in this case is designed as a mouthpiece coating paper (tipping paper, tipping) for a filter of smoking products such as cigarettes, cigarillos, or the like. The substrate 10 is impregnated with an active ingredient 12, which consists of a mixture of benzalkonium chloride and didecyldimethylammonium chloride. The two compounds mentioned can alternatively be used individually. For impregnation, the substrate 10 is printed in a printing press with a solvent consisting of 10 vol.% to 20 vol.% ethanol, 10 wt.% to 30 wt.% of the active ingredient, and the remainder being water. Alternatively, the solvent can contain 70 vol.% or more ethanol or be practically anhydrous (apart from an azeotropic water content of the ethanol).

[0037] Fiber-based substrates, especially thin papers, typically change their dimensions primarily in the transverse direction and / or tend to wrinkle when directly exposed to a water-based substance. Therefore, protective coatings with primers are usually necessary to prevent excessive water penetration into the substrate 10. However, due to the ethanol content in the solvent and the high concentration of the active ingredient used here, wrinkling or geometric changes can be advantageously avoided. Ethanol also has antibacterial properties and helps to eliminate any existing bacterial contamination on the substrate 10 during this impregnation process. Furthermore, the ethanol content facilitates and accelerates the final drying of the substrate 10.The impregnated substrate 10 exhibits a particularly high and long-lasting antimicrobial efficacy, since the active substance or the active substance mixture is distributed throughout the entire volume of the substrate 10.

[0038] Fig. 2 shows a schematic sectional view of a double-sided coated cardboard substrate 10. In contrast to the previous embodiment, the substrate 10 is not impregnated, but has a coating 14 on both sides, each containing benzalkonium chloride and / or didecyldimethylammonium chloride as the active ingredient 12. The coatings 14 can be applied independently of each other using all common printing and coating processes. The active ingredient 12 can also be applied in aqueous solutions or dispersions (e.g., in water, water, or water).

[0039] The coatings may contain overprint varnishes based on acrylates or similar substances, which are then used to coat the substrate 10. The proportion of the active ingredient fs 12 in the coatings 14 can be up to 50 wt.%, in particular between 1 wt.% and 10 wt.%, independently of one another.

[0040] Alternatively, only one side of the substrate 10 can be coated, or only one side of the substrate 10 can be coated with the coating 14 containing the active ingredient 12. The coating 14 does not necessarily have to be applied directly to the substrate 10. Layer systems with two or more layers are also possible. Preferably, however, the coating 14 is the outermost layer to ensure the highest possible efficacy at the surface of the substrate 10.

[0041] Fig. 3 shows an exemplary schematic sectional view of an impregnated, coated, and coated paper substrate 10. In contrast to the previous embodiment, the substrate 10 is impregnated and has a coating 14 with the active ingredient 12 only on one side. A line 16 is also arranged between the coating 14 and the substrate 10.

[0042] Line 16 is known in the art and is a binder application ("line") for refining the surface of the paper substrate. So-called coating paint is used as the material for the binder application. The parameter values ​​specified in the documentation for defining process and measurement conditions for characterizing specific properties of the invention are also to be considered as included in the scope of the invention, even in the case of deviations – for example, due to measurement errors, system errors, weighing errors, DIN tolerances, and the like. REFERENCE MARK LIST:

[0043] 10 substrate

[0044] 12 active ingredient

[0045] 14 Coating

[0046] 16 lines

Claims

Patent claims 1. Substrate (10) with antimicrobial properties, which consists at least partially of a cellulose material, in particular of paper, cardboard and / or paperboard, characterized in that the substrate (10) has at least one coating (14) and / or impregnation with an antimicrobial agent (12) from the group consisting of benzalkonium chloride, didecyldimethylammonium chloride and mixtures thereof.

2. Substrate (10) according to claim 1, characterized in that the at least one coating (14) is applied to the substrate (10) by means of a method from the group consisting of offset printing, digital printing, flexographic printing, screen printing, gravure printing, varnishing, curtain coating, laminating, cellophane wrapping, UV coating and embossing.

3. Substrate (10) according to claim 1 or 2, characterized in that, to produce the at least one coating (14), one or more from the group consisting of inks, in particular coating and / or printing inks, varnishes, in particular clear varnishes and / or effect varnishes, binders, in particular adhesives, inks, water- or solvent-based coating materials, films, UV-curable coatings, chemically curable coatings, embossing foils, transfer foils and adhesive coatings are applied to the substrate (10) and optionally dried and / or cured.

4. Substrate (10) according to one of claims 1 to 3, characterized in that the proportion of the active ingredient (12) in the coating is up to 50 wt.%, in particular between 1 wt.% and 10 wt.%.

5. Substrate (10) according to one of claims 1 to 4, characterized in that the impregnation is produced by first dissolving the active ingredient (12) in an ethanol-containing solvent, after which the substrate (10) is treated with the impregnated and / or sprayed and / or printed with the solvent containing the active ingredient (12).

6. Substrate (10) according to claim 5, characterized in that the solvent contains at least 5 vol%, in particular between 10 vol% and 20 vol% or more ethanol and / or that the solvent contains at least 5 wt%, in particular between 10 wt% and 30 wt% of the active ingredient (12).

7. Substrate (10) according to one of claims 1 to 6, characterized in that the cellulose material consists of virgin fibers or at least partially of recycled fibers.

8. Substrate (10) according to one of claims 1 to 7, characterized in that it is coated on one or both sides at least in certain areas.

9. Substrate (10) according to one of claims 1 to 8, characterized in that it is designed as mouthpiece lining paper, parchment paper, inner liner, molding material, fiber molding material, whole wrapper, liner sheet, outer cover sheet, heat not burn product, blank and / or packaging, in particular food packaging, hinge lid packaging or pharmaceutical packaging.

10. Mouthpiece coating paper comprising or consisting of a substrate (10) according to any one of claims 1 to 9.

11. Cut-to-size, in particular for packaging, comprising or consisting of a substrate (10) according to any one of claims 1 to 9.

12. Packaging, in particular food packaging or pharmaceutical packaging, which consists at least partially of a substrate (10) according to any one of claims 1 to 9 and / or of a blank according to claim 11.

13. Method for impregnating a substrate (10) for a mouthpiece coating paper, wherein the substrate (10) is at least partially composed of a cellulose material, in particular of paper, and the process includes at least the following steps: Providing a solvent comprising ethanol and an antimicrobial agent (12) from the group consisting of benzalkonium chloride, didecyldimethylammonium chloride and mixtures thereof; and Impregnating the substrate with the active ingredient (12) by sprinkling the substrate with the solvent containing the active ingredient (12).

14. Method according to claim 13, characterized in that the solvent contains at least 5 vol%, in particular between 10 vol% and 20 vol% or more ethanol and / or wherein the solvent contains at least 5 wt%, in particular between 10 wt% and 30 wt% of the active ingredient (12) and / or wherein the solvent contains water.

15. Method according to one of claims 13 to 14, characterized in that the substrate (10) is impregnated by impregnating the substrate (10) with the solvent and / or spraying and / or printing.

16. Method according to one of claims 13 to 15, characterized in that the substrate (10) is dried after impregnation.

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