Aerosol-generating articles with reduced visual defects

Abstract

The present invention relates to an aerosol-generating article (1) comprising a filter (2) and an aerosol-generating rod (6). The filter comprises at least one filter segment. The filter segment comprises a filter medium containing a liquid additive and at least one filter wrapper. The filter wrapper can be, for example, a plug wrap. The filter wrapper extends from a first end to a second end of the filter to encapsulate the filter medium.

Description

[Technical Field]

[0001] The present invention relates to an aerosol-generating article comprising a filter and an aerosol-generating rod with reduced visual defects. [Background technology]

[0002] Smoking articles, such as cigarettes, are mass-produced consumer goods. They typically comprise a tobacco rod formed by encasing tobacco cut filler with a paper-based wrapper within a longitudinally extending, generally cylindrical rod. Beyond their primary tobacco-enveloping function, paper-based smoking article wrappers often also form a communication aid for manufacturers and may comprise various printed designs, colors, and / or markings (watermarks, embossing, etc.), which may form part of a branding function that allows consumers to recognize the product, among other things. Therefore, providing an attractive appearance for cigarette paper is highly valued. To provide a high-quality appearance for cigarettes and / or cigarette paper, visible contamination of the paper surface should be avoided.

[0003] In the following, the terms "smoking article" and "cigarette" are used interchangeably. In recent years, so-called "heat-and-no-burn" devices have become more popular. In such devices, a flavor source is not burned, but heated to generate an aerosol that can be consumed by the user. The aerosol-generating substrate often includes tobacco. The substrate is often provided in the form of a replaceable cartridge that is inserted into the aerosol-generating device. As with traditional smoking articles such as cigarettes, in these cartridges, the tobacco is often held in place by cigarette paper / wrapper. Some embodiments of the present invention are described only with respect to cigarettes or cigarette paper. However, these embodiments are also applicable to and should be considered disclosed for any other aerosol-generating article and / or aerosol-generating article wrapper.

[0004] Many smoking articles contain liquids. Some liquids, such as menthol, are added as flavoring agents. The taste or characteristics of the aerosol can be further modified by the liquid. Some of these liquids can make the aerosol taste smoother. Examples of such liquids are fatty acids, fatty acid esters, polypropylene glycol (PPG), polypropylene glycol glyceryl ether, and polyethylene glycol (PEG). Furthermore, water from different sources may be present. In particular, natural products such as tobacco may contain water if not sufficiently dried.

[0005] The drawback of liquid in the filter segment is that even with the best average application rate, due to standard variations in raw materials and manufacturing processes, residual liquid can migrate from the filter to the adjacent tobacco section and extract coloring materials from the tobacco. These coloring materials can then migrate to the wrapper, causing unsightly stains on the tobacco wrapper.

[0006] In the past, attempts have been made to prevent such staining by coating the tobacco or wrapper, or to make the wrapper liquid-repellent, but these additional coatings often have adverse taste effects or cause mechanical problems such as paper dust.

[0007] US Patent Application Publication No. 2017 / 332694 A1 discloses a method for producing a wrapped endless rod of substantially planar continuous material. Summary of the Invention [Problem to be solved by the invention]

[0008] It is therefore an object of the present invention to provide an aerosol-generating article that comprises a visible cigarette paper or wrapper that has an appealing appearance, even when liquid is present within the aerosol-generating article. [Means for solving the problem]

[0009] These problems are addressed by an aerosol-generating article comprising a filter and an aerosol-generating rod, wherein the filter comprises at least one filter segment comprising a filter medium containing a liquid additive, and at least one filter wrapper extending from a first end to a second end of the filter for encapsulating the filter medium; the aerosol-generating rod comprises an aerosol-generating substrate and a substrate wrapper enclosing the aerosol-generating substrate; the filter and aerosol-generating rod are assembled together with an outer wrapper that overlaps the filter wrapper and the substrate wrapper, the filter wrapper and the substrate wrapper being adjacent at a first end of the filter; the filter wrapper is formed as a tubular element with a wrapper seam extending along the length of the article, the seam being formed from a sealed overlap region of the filter wrapper; It has been found that the filter wrapper can be overcome by an aerosol-generating article that does not have an anchor adhesive between it and the filter media that extends to the first end of the filter.

[0010] An aerosol-generating article according to the present invention comprises a filter and an aerosol-generating rod. The filter comprises at least one filter segment. The filter segment comprises a filter medium containing a liquid additive and at least one filter wrapper. The filter wrapper can be, for example, a plug wrap. The terms "filter wrapper" and "plug wrap" are both used within the present specification. However, all features disclosed for a particular embodiment of a plug wrap should be understood to be disclosed for any filter wrapper unless otherwise specified. The filter wrapper extends from a first end to a second end of the filter to encapsulate the filter medium.

[0011] The aerosol-generating rod comprises an aerosol-generating substrate and a substrate wrapper. The substrate wrapper can be, for example, tobacco paper. The terms "substrate wrapper" and "tobacco paper" are both used within the present specification. However, it should be understood that all features disclosed for a particular embodiment of tobacco paper are also disclosed for any substrate wrapper unless expressly stated otherwise. The substrate wrapper encapsulates the aerosol-generating substrate.

[0012] The filter and aerosol-generating rod are combined together with an outer wrapper. The outer wrapper can be, for example, tipping paper. The terms "outer wrapper" and "tipping paper" are both used within the present specification. However, it should be understood that all features disclosed for a particular embodiment of tipping paper are also disclosed for any outer wrapper unless expressly stated otherwise.

[0013] The outer wrapper overlaps the filter wrapper and the substrate wrapper. The filter wrapper and the substrate wrapper are adjacent at a first end of the filter. The filter wrapper is formed as a tubular element and includes a wrapper seam extending along the length of the article. The seam is formed from a sealed overlap region of the filter wrapper. A further essential feature of the aerosol-generating article according to the present invention is that the filter wrapper does not have an anchor adhesive between it and the filter media that extends to the first end of the filter.

[0014] Such aerosol-generating articles reduce or even prevent the diffusion of liquid from the filter to the adjacent tobacco section. Therefore, coloring substances cannot be extracted from the tobacco, which, if transferred to the wrapper, could cause unsightly staining of the tobacco wrapper. Surprisingly, liquid diffusion can be significantly reduced if the filter wrapper's adhesive does not extend to the first end of the filter. Adhesive lines that extend to the first end of the filter appear to act as promoters of liquid diffusion, which leak into and stain the substrate wrapper. By shortening the promoter line, and preferably providing at least one gap near the first end of the filter, staining can be reduced or even prevented.

[0015] In a preferred embodiment of the aerosol-generating article, the anchor adhesive for the filter media is located no closer to the first end of the filter than 0.2 mm, preferably no closer than 0.4 mm, preferably no closer than 0.8 mm, more preferably no closer than 0.8 mm, more preferably no closer than 1 mm, and most preferably no closer than 3 mm. The distance between the first end and the anchor adhesive has been found to be sufficient to inhibit moisture transfer between the filter segment and the aerosol-generating rod. However, the adhesive contact surface is still large enough to secure the filter wrapper.

[0016] In a preferred embodiment of the aerosol-generating article, the filter wrapper is secured to the filter media by at least one discontinuous anchor, preferably a discontinuous anchor of adhesive that begins longitudinally at a distance from the first end of the filter. Thus, the adhesive provides a secure bond between the wrapper ends but does not promote the diffusion of liquid to the first end of the filter where it can pass to the aerosol-generating rod.

[0017] In a preferred embodiment of the aerosol-generating article, the filter wrapper is secured to the filter media by a single anchor extending both longitudinally and circumferentially around the article, where the longitudinal extension is longer than the circumferential extension. Alternatively or additionally, the filter inner side is secured by multiple anchors extending longitudinally and, in some cases, circumferentially around the article, where the multiple anchors extend longer than the circumferential anchors. This dedicated arrangement along the longitudinal direction of the article further reduces the risk of soiling by limiting the spread of liquid toward the periphery of the article.

[0018] In a preferred embodiment of the aerosol-generating article, the filter wrapper is secured to the filter media by adhesive anchor dots that begin a distance longitudinally from the first end of the filter. Preferably, the adhesive anchor dots are arranged along a line extending along the length of the filter from the first end to the opposite second end. It has been found that adhesive dots can be easily applied using known devices. Furthermore, when provided as dots instead of a continuous line, less adhesive is consumed. Thus, anchor portions can be produced at low cost. An additional advantage of the dots is that they can be applied so that they are separated from one another. Thus, liquid diffusion is prevented not only in the area adjacent to the first end of the filter, but also in areas away from the first end, and any gaps between adjacent dots can be considered a barrier that prevents or at least slows liquid diffusion along the length of the filter toward the first end.

[0019] In a preferred embodiment of the aerosol-generating article, the filter wrapper is secured to the filter media by a nonlinear but continuous layer of anchor adhesive that begins longitudinally at a distance from the first end of the filter wrapper. The curved layout results in an elongated path compared to a straight line. Therefore, liquid diffusion along the filter's length toward its first end is slowed. Furthermore, it has been found that a sharp curve results in a localized slowdown of diffusion along the curved path. This may be explained by locally increased moisture in the curved area. This effect also slows liquid diffusion along the filter's length toward its first end.

[0020] In a preferred embodiment of the aerosol-generating article, the filter wrapper is secured to the filter media by a spiral or multiple ring-shaped layer of anchor adhesive. Both of these geometries have been found to be advantageous because they also provide the above-mentioned benefits. The spiral anchor adhesive geometry further extends the length of the anchor adhesive line. Therefore, the relative rate of diffusion along the length of the filter toward its first end is reduced. The multiple ring-shaped anchor adhesive geometry provides a circle in which diffusion is accelerated. However, moisture is trapped inside the rings or in the annular portion formed by the anchor adhesive. This also results in a slower diffusion of liquid along the length of the filter toward its first end.

[0021] In preferred embodiments of the aerosol-generating article, the liquid additive in the filter medium contains an oily substance and / or a flavoring substance. These liquids can be used to change the taste or characteristics of the aerosol. For example, some liquids can make the aerosol taste smoother.

[0022] In a preferred embodiment of the aerosol-generating article, the liquid additive in the filter medium is present in an amount (per filter) of at least 1 mg, preferably 1 to 50 mg, more preferably 10 to 20 mg, which amounts have been found to be suitable for improving the taste or characteristics of the aerosol as it passes through the filter.

[0023] In a preferred embodiment of the aerosol-generating article, the liquid additive is selected from the group consisting of alcohols, fatty acids, fatty acid esters, polyether polymers, essential oils, and combinations thereof. More preferably, the liquid is selected from the group consisting of polypropylene glycol (PPG), polypropylene glycol glyceryl ether, polybutylene glycol, diglycerin, sorbitan fatty acid esters, glycerin fatty acid esters, polyglycerin fatty acid esters, propylene glycol fatty acid esters, polyethylene glycol, caprylyl glycol, and combinations thereof. At least some of these substances are suitable for reducing the amount of phenols from the aerosol, resulting in a smoother taste for the user.

[0024] In a preferred embodiment of the aerosol-generating article, the filter medium comprises paper and / or other natural cellulose fibers. Filter media comprising paper and / or other natural cellulose fibers have been found to be particularly suitable because moisture diffusion through these media is slow. Thus, if diffusion along the adhesive to the first end of the filter segment is not possible or is very slow because the adhesive anchoring portion begins at a distance from the first end, overall diffusion of liquid from the filter segment to the aerosol-generating substrate is not possible or is very slow.

[0025] In a preferred embodiment of the aerosol-generating article, the filter wrapper is free of a hydrophobic or oleophobic coating. Because the diffusion of liquids through the filter material can usually be controlled, the wrapper has been considered important for controlling moisture diffusion. Therefore, attempts have been made to reduce the diffusion of liquids from the filter segment to the aerosol-generating substrate by applying a hydrophobic or oleophobic coating to the wrapper. However, these coatings present drawbacks because they can adversely affect the taste of the aerosol. The present invention provides a different method for preventing or slowing the diffusion of liquids. It is possible and preferable to provide a filter wrapper without a hydrophobic or oleophobic coating. Therefore, the taste of the aerosol is not adversely affected by the wrapper coating.

[0026] In a preferred embodiment, the aerosol-generating article is a combustible or heat-and-burn article for heating in an electrical aerosol-generating device. Thus, the aerosol-generating article may preferably be provided as a traditional tobacco product, such as a cigarette, cigar, cigarillo, or cigarette, or as an aerosol substrate for a so-called "heat-and-burn" device. This type of device generates aerosol and / or vapor by heating a solid aerosol substrate, typically comprising tobacco, to a temperature typically in the range of 200°C to 350°C.

[0027] Experiments have been conducted to evaluate the advantages of an aerosol-generating article according to the present invention (line 2) over an aerosol-generating article according to the prior art (line 1). The prior art aerosol-generating article comprises a filter having an anchor adhesive that extends to just the first edge of the filter adjacent to the aerosol-generating substrate. In contrast, the anchor adhesive of the aerosol-generating article according to the present invention (line 2) does not extend to just the first edge of the filter adjacent to the aerosol-generating substrate.

[0028] As shown in Table 1, when 200 aerosol-generating articles according to the prior art were stored under "normal conditions" (22°C and 60% relative humidity (RH)), tipping paper (TP) staining was observed in 14 rods, representing 7% of all rods. In contrast, when stored under the same conditions, staining was observed in only a single aerosol-generating article according to the present invention (representing 0.5%). Cigarette paper (CP) staining was not observed in any of the aerosol-generating articles when stored under these conditions.

[0029] When stored under so-called "climatic conditions" (35°C and 40% relative humidity (RH)), tipping paper (TP) staining was observed in 18 rods of aerosol-generating articles according to the prior art. This corresponds to 9% of all rods. In contrast, when stored under the same conditions, staining was observed in only 6 rods (corresponding to 3%) of aerosol-generating articles according to the present invention. Cigarette paper (CP) staining was not observed in any of the aerosol-generating articles when stored under these conditions.

[0030] [Table 1]

[0031] Further advantages, objects and features of the present invention will be explained, by way of example only, in the following description with reference to the accompanying drawings, in which similar components in different embodiments may be given the same reference signs, and in which: [Brief explanation of the drawings]

[0032] [Figure 1a] 5A-5C are schematic representations of different embodiments of wrapper seam placements in overlap regions of filter wrappers of an aerosol-generating article. [Figure 1b] 5A-5C are schematic representations of different embodiments of wrapper seam placements in overlap regions of filter wrappers of an aerosol-generating article. [Figure 1c]5A-5C are schematic representations of different embodiments of wrapper seam placements in overlap regions of filter wrappers of an aerosol-generating article. [Figure 1d] 5A-5C are schematic representations of different embodiments of wrapper seam placements in overlap regions of filter wrappers of an aerosol-generating article. [Figure 2] Photos of different stains on chipping paper. DETAILED DESCRIPTION OF THE INVENTION

[0033] FIG. 1a shows a schematic diagram of a wrapper seam arrangement in the overlap region of a filter wrapper of an aerosol-generating article as known from the prior art. The aerosol-generating article 1 comprises a filter 2 and an aerosol-generating rod 6. The filter 2 and the aerosol-generating rod 6 are arranged adjacent to each other along the longitudinal direction of the aerosol-generating article 1. They are held together by an outer wrapper (not shown) that partially overlaps the filter wrapper and a substrate wrapper (not shown). The filter wrapper surrounds the filter material. The ends of the filter wrapper are attached to each other by a seam 4 that extends along the longitudinal direction of the article. The seam 4 is formed by the sealed overlap region of the filter wrapper. The filter wrapper seam extends to a first end of the filter 2, adjacent to the aerosol-generating rod 6.

[0034] Diffusion allows the liquid 3 to travel along the seam 4 from any location on the filter to the first end of the filter 2 adjacent the aerosol-generating rod 6 .

[0035] 1b shows a schematic diagram of a single droplet of liquid 3 on the surface of filter material 2. The size of droplet 3 is limited because migration and diffusion through filter material 2 is limited. If a seam were not present, liquid 3 would not migrate through the filter to the first end of filter 2, adjacent aerosol-generating rod 6.

[0036] Figure 1c shows a schematic diagram of the wrapper seam arrangement in the overlap region of the filter wrapper of an embodiment of an aerosol-generating article according to the present invention. Similar to the aerosol-generating article 1 shown in Figure 1a, the aerosol-generating article 1 comprises a filter 2 and an aerosol-generating rod 6. The filter 2 and the aerosol-generating rod 6 are positioned adjacent to each other along the longitudinal direction of the aerosol-generating article 1. They are held together by an outer wrapper (not shown) that partially overlaps the filter wrapper and the substrate wrapper (not shown). The filter wrapper surrounds the filter material 2. The ends of the filter wrapper are attached to each other by a seam 4. The seam is formed by anchor adhesive arranged in overlapping circles (or ovals). However, the seam does not extend to the first end of the filter 2 adjacent to the aerosol-generating rod 6.

[0037] Due to the geometry of the seam and the different concentrations of anchor adhesive in different regions of the filter wrapper, liquid migration and diffusion is restricted: liquid tends to concentrate in areas with high anchor adhesive concentration, while areas with low or no anchor adhesive concentration have low concentrations of liquid 3.

[0038] Because the seam and / or anchor adhesive does not extend to the first end of the filter 2 adjacent the aerosol-generating rod 6, the concentration of liquid in this area is very low and the liquid cannot migrate from the filter to the aerosol-generating rod 6. Therefore, the liquid cannot extract the coloring material from the aerosol-generating substrate, and the coloring material may cause staining of the paper as it migrates to the surface of the aerosol-generating rod 6 or surrounding tipping paper.

[0039] Figure 1d shows a schematic diagram of the wrapper seam arrangement in the overlap region of the filter wrapper of a further embodiment of an aerosol-generating article according to the present invention. Similar to the aerosol-generating article 1 shown in Figure 1c, the ends of the filter wrapper are attached to one another by a seam 4. However, the seam is formed by anchor adhesive arranged as several spaced apart dots. None of these dots extend to the first end of the filter 2, adjacent the aerosol-generating rod 6.

[0040] The liquid 3 present in the filter material 2 remains in high concentration in the area surrounding the dots of anchor adhesive. Depending on the spacing between two adjacent dots, the migration of liquid from one dot to the next is very limited.

[0041] Because the anchor adhesive dots are not positioned in the region next to the first end of the filter 2, adjacent to the aerosol-generating rod 6, the concentration of liquid in this region is very low and the liquid cannot migrate from the filter to the aerosol-generating rod 6. As described above for the arrangement shown in Figure 1c, the liquid cannot contact the aerosol-generating substrate to extract coloring substances that could cause staining of the paper.

[0042] Figure 2 shows photographs of different stains on the tipping paper. In the photograph on the left, the stain is very noticeable and extends to the cigarette paper (CP). In the photograph shown on the right, the stain is only present on the tipping paper (TP). It was found that the stain occurs mainly in the ring. [Explanation of symbols]

[0043] 1. Aerosol-generating items 2. Filters and filter materials 3 Liquid, drops, polypropylene glycol 4 Seams, anchor glue, rings, circles, dots 6. Aerosol-generating materials and aerosol-generating rods

Claims

1. An aerosol-generating article comprising a filter and an aerosol-generating rod, the filter comprising at least one filter segment comprising a filter medium containing a liquid additive, and at least one filter wrapper extending from a first end to a second end of the filter for encapsulating the filter medium; the aerosol-generating rod comprises an aerosol-generating substrate and a substrate wrapper enclosing the aerosol-generating substrate; the filter and the aerosol-generating rod are assembled together with an outer wrapper that overlaps the filter wrapper and the substrate wrapper, the filter wrapper and the substrate wrapper being adjacent at the first end of the filter; the filter wrapper is formed as a tubular element and includes a wrapper seam extending along the length of the article, the seam being formed from a sealed overlap region of the filter wrapper; the filter wrapper does not have an anchor adhesive between it and the filter media that extends to the first end of the filter; the filter wrapper is secured to the filter media by a discontinuous anchor portion of adhesive beginning in the longitudinal direction a distance from the first end of the filter; the filter wrapper is secured to the filter media by anchor dots of adhesive that begin in the longitudinal direction a distance from the first end of the filter; Aerosol-generating items.

2. 2. The aerosol-generating article of claim 1, wherein the filter wrapper is secured to the filter media by a non-linear but continuous layer of anchor adhesive beginning in the longitudinal direction at a distance from the first end of the filter wrapper.

3. 4. The aerosol-generating article of claim 3, wherein the filter wrapper is secured to the filter media by a spiral or multiple ring-shaped layer of anchor adhesive.

4. 4. The aerosol-generating article according to claim 1, wherein the liquid additive in the filter medium contains an oily substance and / or a flavoring substance.

5. 5. An aerosol-generating article according to any one of claims 1 to 4, wherein the liquid additive in the filter medium is present in an amount of at least 1 mg, preferably from 1 to 50 mg, more preferably from 10 to 20 mg.

6. 6. The aerosol-generating article of claim 1, wherein the liquid additive is selected from the group consisting of alcohols, fatty acids, fatty acid esters, polyether polymers, essential oils, polypropylene glycol, polypropylene glycol glyceryl ether, polybutylene glycol, diglycerin, sorbitan fatty acid esters, glycerin fatty acid esters, polyglycerin fatty acid esters, propylene glycol fatty acid esters, polyethylene glycol, caprylyl glycol, and combinations thereof.

7. 7. The aerosol-generating article of claim 1, wherein the filter medium comprises paper and / or other natural cellulose fibers.

8. An aerosol-generating article according to any one of claims 1 to 7, wherein the filter wrapper is free of a hydrophobic or oleophobic coating.

9. 9. The aerosol-generating article according to any one of claims 1 to 8, which is a combustible or non-combustible article for heating in an electric aerosol generating device.

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