Mouth piece paper with nano-embossing

Abstract

The invention relates to a nano-embossed tipping paper (1) which comprises a coating layer (2) containing nitrocellulose or ethyl cellulose, wherein the coating layer (2) is either a clear coating layer or a coloured coating layer and is provided with a nanostructure by means of mechanical embossing.

Description

[0001] The invention relates to a mouthpiece coating paper with nano-embossing.

[0002] The invention relates in particular to mouthpiece coating paper for cigarettes and heat-not-burn consumer products or, more generally, to mouthpieces of aerosol-generating consumer products.

[0003] The mouthpiece coating paper, often also referred to as "tipping paper" or simply "tipping," is the part of the aerosol-generating product that comes into contact with the lips when smoking a filter cigarette or heating a heat-not-burn product. The mouthpiece coating paper encases the filter and typically extends slightly lengthwise into the tobacco strand or aerosol-generating substrate, thus encasing the cigarette paper or the outer material of the aerosol-generating substrate.

[0004] The mouthpiece lining paper is usually actually paper, but it can also be a film or a composite material made of several layers of different materials.

[0005] Mouthpiece lining paper often features a printed design. For example, this design might resemble cork. However, mouthpiece lining papers are also used that are white in the area touched by the lips.

[0006] WO2019191795 of the applicant mainly discloses variants in which the base paper is first embossed, so that it is evident that the embossing is present in the paper. In variants in which the active substance is applied after embossing, this coating is not embossed. The variant with the coating applied before embossing is indicated as less preferred in WO2019191795, although it is also clarified here that the coating is pressed into the material web by the embossing or compacted in the recesses of the material web. This demonstrates that even in this variant of WO2019191795, the base paper is embossed, so that the base paper itself has raised and recessed areas. This must be the case in WO2019191795, as otherwise the purpose could not be achieved: that the active substance is present in the recesses of the embossed structure and is less effective or has a delayed effect there than in other areas.

[0007] In WO2014040111A1, the applicant states that a varnish can be a textured varnish. However, the textured varnish itself is printed in a grid or other structure, for example, in fine lines. The structure of the textured varnish is thus produced in a different way than by embossing.

[0008] To increase the resistance to moisture of the mouthpiece coating paper, it is known to provide a so-called lip-release coating in the area of ​​the mouthpiece coating paper that is touched by the lips.

[0009] It is known to create a colored print, particularly on cork, using a colored varnish, and to apply an additional varnish over this colored varnish. This additional varnish is called a lip-release varnish. It is also known to first apply a clear varnish to white mouthpiece lining paper, followed by an additional lip-release varnish, which may also consist of an additional layer of the clear varnish. Another known embodiment involves first printing the mouthpiece lining paper with a non-film-forming ink, applying a clear varnish over this print, and then applying an additional varnish layer over the clear varnish to create the lip-release effect.

[0010] The object underlying the invention is to improve the moisture resistance or water-repellent properties of a clear coat or colored lacquer in order to create alternatives to the application of an additional lip release lacquer.

[0011] To solve the problem, a mouthpiece coating paper according to claim 1 is proposed. The mouthpiece coating paper has a clear lacquer layer or a colored lacquer layer based on a nitrocellulose lacquer or ethylcellulose lacquer, wherein the lacquer layer is provided with a nanostructure by a mechanical embossing process.

[0012] The nanostructure in the clear coat or colored coat advantageously achieves a lotus effect or improves the hydrophobic effect of the coating.

[0013] The nanostructure also allows for optical effects, which further make it more difficult to counterfeit the mouthpiece coating paper.

[0014] Known methods are suitable for producing the nanostructure, such as in particular the one disclosed in EP 2222711 B1.

[0015] From EP 2222711 B1, it is known to produce a nanostructure in a layer of a thermoplastic carbohydrate polymer, in particular a hydrophobic starch ester, to achieve special optical effects that can be decorative and difficult to imitate. EP 2222711 B1 mentions cigarette paper as a possible application, but a specific implementation for carrying out the process on cigarette paper is not disclosed. In technical terms, cigarette paper refers to the paper wrapping the tobacco strand of a cigarette, whereby the cigarette usually has an additional mouthpiece covering paper that has different properties compared to the cigarette paper.

[0016] Nanoembossing is carried out, for example, at a temperature of at least 90°C, in particular at least 100°C, and a pressure of 1.5 bar.

[0017] The depth of the depressions of the nano-embossing structure can also be taken from EP 2222711 B1 and is in the range of 10 nm to 1500 nm, preferably 50 nm to 1000 nm and particularly 75 nm to 800 nm.

[0018] The distance between the depressions of the nano-embossing structure is in the range of 10 nm to 1500 nm, preferably 50 nm to 1000 nm and particularly 100 nm to 500 nm.

[0019] Preferably, in the present invention, a planar area is provided with the nano-embossed structure, which extends in a band-like fashion along an entire side of the mouthpiece coating paper, so that a ring-shaped area with the nano-embossed structure is present on the aerosol-generating article. The individual microstructures of the nano-embossed structure are preferably densely or seamlessly adjacent to one another in order to obtain a planar area with improved water-repellent properties.

[0020] Nanoembossing is preferably carried out on a continuously moving strip of mouthpiece coating paper, wherein this is provided with the nanostructure between two rollers (embossing roller and counter-pressure roller) by transferring the embossing structure of the embossing roller into the varnish layer by means of heat and pressure, wherein either the embossing roller is heated and / or the varnish layer is heated before embossing.

[0021] The present invention provides a suitable layer structure of the mouthpiece coating paper, suitable lacquer compositions, and a system to make mechanical embossing processes applicable for the production of a nanostructured mouthpiece coating paper.

[0022] A lacquer is a film-forming substance.

[0023] In one version, the varnish is a clear varnish which hardens to form a transparent varnish layer.

[0024] Nitrocellulose clear lacquer is particularly preferred.

[0025] The clear coat comprises nitrocellulose or ethylcellulose and one or more solvents selected from the group including ethanol, ethyl acetate, and isopropanol. These solvents may be present as aqueous solutions, so the coat may contain nitrocellulose or ethylcellulose, an organic solvent, and water. The clear coat may also contain effect pigments (e.g., pearlescent, metallic, etc.).

[0026] The clear lacquer composition is preferably applied in an amount of 0.25 g / m² to 2 g / m², particularly preferably 0.5 g / m² to 1 g / m².

[0027] The clear coat can also be in the form of a gloss varnish containing effect pigments, for example, metallic effect pigments, pearlescent pigments, or interference pigments. The gloss varnish preferably comprises nitrocellulose or ethylcellulose, effect pigments, and one or more solvents selected from the group consisting of ethanol, ethyl acetate, and isopropanol. The aforementioned solvents are preferably present as aqueous solutions, so that the varnish comprises nitrocellulose or ethylcellulose, effect pigments, an organic solvent, and water.

[0028] The application of the gloss lacquer composition is preferably carried out in an amount of 0.25 g / m² to 8 g / m², particularly preferably 2 g / m² to 6 g / m².

[0029] In a second embodiment, the lacquer is a colored lacquer that hardens to form a colored lacquer layer. The colored lacquer layer is preferably opaque. The colored lacquer layer can be a vibrant color, or it can be gray or black.

[0030] The paint lacquer comprises nitrocellulose or ethylcellulose, color pigments, and one or more solvents selected from the group including ethanol, ethyl acetate, and isopropanol. These solvents may be present as aqueous solutions, so the paint lacquer may consist of nitrocellulose or ethylcellulose, color pigments, an organic solvent, and water. The paint lacquer may also contain additives and / or fillers.

[0031] The paint may also contain effect pigments (e.g., pearlescent, metallic, etc.). These effect pigments could be, for example, metallic effect pigments, pearlescent pigments, or interference pigments.

[0032] The application of the paint composition is preferably carried out in an amount of 0.25 g / m² to 8 g / m², particularly preferably 1 g / m² to 4 g / m².

[0033] The colored lacquer is preferably applied as a single-color coating to the surface. The coating can be in the form of a single strip or several spaced-apart strips.

[0034] The lacquer composition has a viscosity of 8 to 30 seconds, particularly 10 to 25 seconds. The clear lacquer preferably has a viscosity of 8 to 16 seconds, particularly 10 to 14 seconds. The viscosity value is determined using a flow cup test with a cup diameter of 4 mm (ISO cup 4 mm according to EN ISO 2431 version 1993-02-15).

[0035] The clear coat or colored varnish is preferably applied by gravure printing, in particular rotary gravure printing.

[0036] The coating is preferably applied in one layer, less preferably in two layers.

[0037] The coating is preferably applied directly to the base paper of the mouthpiece coating paper.

[0038] The base paper preferably has a basis weight of 30 to 60 g / m², particularly preferably 30 to 50 g / m².

[0039] The varnish is preferably applied to an untreated surface of the base paper. The base paper is therefore preferably uncoated.

[0040] In one embodiment, the coating is applied in the form of one or more bands of colored lacquer on a white base paper. The coated mouthpiece covering paper preferably has at least one white area and one area with a colored layer, these areas preferably extending in a band-like fashion in the circumferential direction of the aerosol-generating consumer product.

[0041] Preferably, the mouthpiece coating paper has a coating of color that mimics the appearance of cork.

[0042] In one version, the paint application can be a layer of colored lacquer, as already described.

[0043] In a second embodiment, the color application can be a non-film-forming coating or print, for example in the form of a colored ink or printing ink, with a clear varnish applied over the colored coating as described above. The clear varnish layer preferably covers the entire mouthpiece coating paper or is arranged as one or more band-shaped colored layers.

[0044] The nano-embossing takes place in the clear coat layer or in the colored coat layer.

[0045] The nano-embossing is preferably carried out across the entire mouthpiece coating paper or registered to form a band-shaped lacquer layer or several band-shaped lacquer layers.

[0046] The nano-embossing is preferably carried out across the entire surface and independently of the colored coating, since the nanostructure is not visible or barely visible in the white areas.

[0047] The varnish is applied to a continuously moving web of base paper. After application, the web is preferably moved through a drying device.

[0048] Heating dryers, in particular hot air dryers and / or heated rollers, are preferably used as drying devices. Infrared emitters may be used alternatively or additionally, though less preferably.

[0049] After the lacquer layer has dried, the material web is wound into a spool or fed directly to the embossing device for nanostructure production. Once the nanostructure has been produced, the material web is wound into a spool or the nanostructured material web is fed to a cigarette manufacturing machine.

[0050] The lacquer layer is preferably applied over a large area and at least in the area that is touched by the lips.

[0051] The finished nanostructured mouthpiece coating paper preferably comprises a base paper on which a lacquer layer is directly applied, wherein the nanostructure is embossed in the lacquer layer.

[0052] Less preferably, the mouthpiece coating paper may comprise a film, in particular of cellulose hydrate, in addition to the base paper. Less preferably, the mouthpiece coating paper may consist of a film, in particular of cellulose hydrate, or be in the form of a laminate of several films.

[0053] The mouthpiece lining paper may also contain foil elements, especially metallic foil elements. These are present particularly as thin strips or logos.

[0054] These foil elements are preferably applied before the nano-embossing of the mouthpiece coating paper. Application is carried out according to known methods, in particular by embossing processes such as hot stamping, wherein the foil element is applied to the mouthpiece coating paper by pressure or pressure and heat from a transfer element. In this case, the nano-embossing also imparts an optical effect to the foil elements.

[0055] Less commonly, foil elements can also be applied after nano-embossing.

[0056] Foil elements can also be embossed with optical effects before being transferred to the mouthpiece coating paper, so that the foil elements and the lacquer layer have different embossings or different effects.

[0057] The invention also includes a system for the production of mouthpiece coating paper, comprising: a machine for coating the mouthpiece covering paper with varnish, a machine for hot stamping the mouthpiece covering paper and a machine for nano stamping the mouthpiece covering paper.

[0058] Optionally, a machine for printing the mouthpiece coating paper with ink can be arranged upstream of the machine for coating the mouthpiece coating paper with varnish, or the machine for coating the mouthpiece coating paper with varnish can also have means for printing with a printing ink.

[0059] Optionally, a machine for printing on the mouthpiece coating paper may also be available, which prints multi-colored logos onto the mouthpiece coating paper.

[0060] The mouthpiece coating paper is moved through the respective machine as a belt, with the application of lacquer and nano-embossing preferably taking place continuously in the longitudinal direction of the belt.

[0061] In an advantageous embodiment, the strip of mouthpiece coating paper is not transferred from one machine to the next, but is wound into a bobbin after each machine and transferred to the next machine.

[0062] The belt, which is moved by the machine to coat the mouthpiece covering paper with lacquer, is composed of several mouthpiece covering papers arranged transversely to the direction of movement. The direction of the mouthpiece covering paper that runs transversely to the direction of movement, i.e., along the width of the belt, is later arranged longitudinally in the consumer product. Preferably, the belt has 10 to 60, and in particular 15 to 25, individual mouthpiece covering papers arranged transversely to the direction of movement.

[0063] Preferably, the machine for coating the mouthpiece coating paper with varnish has a cutting device which cuts the strip longitudinally after it has been coated with the varnish layer, so that at least two narrower strips of varnish-coated mouthpiece coating papers are obtained, each of which is wound into a bobbin.

[0064] Preferably, these bobbins are fed with narrower bands to the device for hot stamping the mouthpiece coating paper and provided with foil elements.

[0065] Preferably, the machine for hot stamping the mouthpiece covering paper has a cutting device which cuts the strip longitudinally after it has been provided with at least one foil element, so that at least two narrower strips of varnish-coated and foil-element-provided mouthpiece covering papers are obtained, each of which is wound into a bobbin.

[0066] Preferably, these bobbins are fed to the machine with even narrower belts for nano-embossing the mouthpiece coating paper and provided with a nano-embossing.

[0067] In other versions, the nano-embossing machine can be directly connected to the lacquer coating machine or the hot-stamping machine for the mouthpiece coating paper, without intermediate winding into a spool.

[0068] If the nano-embossing machine follows the lacquer coating machine, the material web can be cut lengthwise before or after the nano-embossing machine to obtain narrower webs. In this case, the hot stamping machine for the mouthpiece coating paper can follow the nano-embossing machine.

[0069] The invention is illustrated by drawings: Fig. 1: illustrates the application of an exemplary mouthpiece coating paper according to the invention to a filter cigarette. Fig. 2: illustrates the application of an exemplary mouthpiece coating paper according to the invention to a heat-not-burn consumer product. Fig. 3: illustrates the application of an exemplary mouthpiece coating paper according to the invention to a filter cigarette. Fig. 4: illustrates an exemplary mouthpiece coating paper according to the invention.

[0070] Fig. 1 Illustrates an exemplary structure of a filter cigarette which is equipped with a mouthpiece coating paper 1 according to the invention, which comprises a lacquer layer 2 which has an embossed nanostructure.

[0071] A typical filter cigarette further comprises a cigarette paper 3, which encases a strand 4 of aerosol-generating substrate, usually referred to as the tobacco strand in a filter cigarette. A typical filter cigarette further comprises a filter paper 5, which encases the filter 6. The mouthpiece covering paper 1 in question can also be used on cigarettes without a filter.

[0072] Fig. 2 Illustrates an exemplary structure of a heat-not-burn consumer product, which is equipped with a mouthpiece coating paper 1 according to the invention, which comprises a lacquer layer 2, the lacquer layer 2 having an embossed nanostructure.

[0073] A typical heat-not-burn consumer product further comprises a strand 4 of aerosol-generating substrate, a hollow section 7, a cooling section 8, and a filter 6. These sections may or may not each include their own cladding materials.

[0074] Since the heat-not-burn consumer product heats strand 4 without burning the outer casing material, the mouthpiece lining paper 1 can extend over the entire length of the heat-not-burn consumer product. The mouthpiece lining paper 1 can be multi-layered and, for example, have an inner aluminum layer, at least in the area of ​​strand 4. However, contrary to the illustration, the heat-not-burn consumer product can also have a mouthpiece lining paper 1 that only extends over a portion of the product. In this case, an additional casing material for the strand and, optionally, the other components 6, 7, and 8 may also be present.

[0075] The heat-not-burn consumer product can be heated with an electronic device (heat-not-burn device), wherein the heat-not-burn consumer product is inserted into the device with the strand 4 leading, so that the mouthpiece coating paper 1 and the lacquer layer 4 on it are exposed to the user's lips.

[0076] As shown, preferably in the area where strand 4 is located, or in the area which is fed into the device, there is no lacquer layer present.

[0077] In another known embodiment of a heat-not-burn consumer product, this product itself has a heat source upstream of strand 4, particularly in the form of coal, so that the heating of strand 4 can take place without an electronic device.

[0078] The second coat of paint can be positioned as in the Figs. 1 and 2shown only over a partial area of ​​the mouthpiece coating paper 1 and only in the rear end of the aerosol-generating consumer article facing away from strand 4.

[0079] The mouthpiece coating paper 1 may have perforations which may be present in the area that is not coated with a lacquer layer 2, or which may extend through the lacquer layer 2 and the base paper.

[0080] In another version, the mouthpiece coating paper 1 can be completely coated with the lacquer layer 2, as in Fig. 3 This illustrates the point.

[0081] As in the Figures 1 to 3 As illustrated, the mouthpiece coating paper 1 can additionally have a foil element 9, which can be placed above the lacquer layer 2 or in an area which is not covered by the lacquer layer 2.

[0082] The second coat of paint can be a clear coat or a colored coat.

[0083] In the case of a clear varnish layer, this can be applied to white base paper or to colored printed or coated base paper. The clear varnish layer can cover a larger area than the colored print or coating.

[0084] In the case of a colored lacquer layer, this itself forms the colored coating or the colored area of ​​the mouthpiece lining paper.

[0085] In Fig. 4 Figure 1 shows a strip of a single mouthpiece coating paper 1 in a top view, comprising a base paper, a lacquer layer 2, a colored coated area 10, a nano-embossing, and two foil elements 9. The visible embossing structure of the nano-embossing is illustrated by the diamond pattern. In this example, the nano-embossing is present both in the lacquer layer 2 and on the foil elements 9.

[0086] If it is desired that the foil elements 9 do not have the nanostructure, they can be applied after the nano-embossing has been carried out, or the nano-embossing can be registered outside the areas with foil elements 9.

[0087] In the example, the mouthpiece coating paper 1 is provided in one area with a colored coating 10, which is formed from a colored lacquer layer, or from a colored coating covered with a clear lacquer layer. The clear lacquer layer could be, in the example, the Figure 4 The nano-embossed structure can extend across the entire surface of the mouthpiece coating paper.

[0088] The dark background in the area of ​​the colored printing makes the nano-embossing structure visible as an optical effect, while it is hardly visible in the area of ​​a white mouthpiece coating paper 1 covered with clear varnish.

[0089] It is important to mention that the nano-embossing structure can only be produced in the lacquer layer 2 and the foil elements 9, while exposed areas of the base paper, which result from partial coating with lacquer, do not have the embossing structure, even if they are processed in the same way in the machine for producing the nano-embossing.

[0090] The examples are for illustrative purposes only. The mouthpiece coating paper 1 with the lacquer layer 2, which has an embossed nanostructure, can be found on any type of aerosol-generating consumer product, for example as wrapping material for cigars or cigarillos, or as sheets of wrapping material for hand-rolled cigarettes.

[0091] The mouthpiece coating paper 1 is to be arranged on the aerosol-generating consumer product in such a way that the lacquer layer 2 is located on the outside of the aerosol-generating consumer product. If the lacquer layer 2 is only present in a partial area, this area is to be arranged facing away from strand 4.

Claims

1. A nano-embossed mouthpiece lining paper (1), characterized in that it has a lacquer layer (2) comprising nitrocellulose or ethyl cellulose, wherein the lacquer layer (2) is either a clear lacquer layer or a colored lacquer layer (2) and the lacquer layer (2) is provided with a nano-structure by mechanical embossing, wherein the depth of the depressions in the nano-embossed structure is in the range from 10 nm to 1500 nm and the distance between the depressions of the nano-embossed structure is in the range from 10 nm to 1500 nm.

2. The nano-embossed mouthpiece lining paper (1) according to claim 1, characterized in that the lacquer layer (2) comprises nitrocellulose.

3. The nano-embossed mouthpiece lining paper (1) according to any one of claims 1 to 2, characterized in that the mouthpiece lining paper (1) comprises a base paper with a grammage of 30 to 60, which is provided with the lacquer layer (2).

4. The nano-embossed mouthpiece lining paper (1) according to any one of claims 1 to 3, characterized in that the lacquer layer (2) is a colored lacquer layer which comprises colored pigments.

5. The nano-embossed mouthpiece lining paper (1) according to any one of claims 1 to 3, characterized in that the lacquer layer (2) is a clear lacquer layer which is applied over a colored area of the mouthpiece lining paper (1).

6. The nano-embossed mouthpiece lining paper (1) according to claim 5, characterized in that the colored area of the mouthpiece lining paper (1) is formed by a non-film-forming ink or printing ink.

7. The nano-embossed mouthpiece lining paper (1) according to any one of claims 1 to 6, characterized in that the mouthpiece lining paper (1) comprises at least one foil element (9).

8. The nano-embossed mouthpiece lining paper (1) according to claim 7, characterized in that the lacquer layer and the foil element (9) are provided with the same nano-structure.

9. An aerosol-generating consumer article comprising a nano-embossed mouthpiece lining paper (1) according to any one of claims 1 to 8, characterized in that the nano-embossed lacquer layer (2) is exposed on the outside of the consumer article.

10. A device for producing a nano-embossed mouthpiece lining paper (1) according to any one of claims 1 to 8, characterized in that it comprises a machine for coating the mouthpiece lining paper (1) with lacquer, a machine for hot foil embossing the mouthpiece lining paper (1) and a machine for nano-embossing the mouthpiece lining paper (1), wherein a band can be transported through each machine, which band is composed in the transverse direction of several mouthpiece lining papers (1) for one aerosol-generating consumer article each.

11. The device according to claim 10, characterized in that the machine for coating the mouthpiece lining paper (1) with lacquer has a cutting device for cutting the band in a longitudinal direction and has a winding device which rolls up the cut narrower bands onto bobbins.

12. The device according to claim 11, characterized in that the machine for hot foil embossing the mouthpiece lining paper (1) has a cutting device for cutting the band in a longitudinal direction and has a winding device which rolls up the cut narrower bands onto bobbins, wherein the machine for hot foil embossing the mouthpiece lining paper (1) is located in the manufacturing process downstream of the machine for coating the mouthpiece lining paper (1) with lacquer and upstream of the machine for producing the nano-embossing.

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