Biodegradable filters with improved taste

Abstract

A biodegradable filter for a smoking article is provided that has a good taste profile. [Solution] A filter for a smoking article is provided, comprising a segment including a filtering substrate containing natural cellulose fibers, the filtering substrate including a segment containing a composition including an additive for reducing phenols, and a wrapper at least partially surrounding the segment.

Description

[Technical Field]

[0001] The present invention relates to a filter for a smoking article that has improved biodegradability and that has an improved taste during smoking of the smoking article. [Background technology]

[0002] Smoking article filters are typically made of cellulose acetate tow, which is particularly selective for filtering phenols but which degrades slowly unless specially treated. Therefore, various materials are being tested as replacements for cellulose acetate in smoking article filters.

[0003] For example, a filtering material containing polylactic acid is disclosed in International Publication No. 2015124242. However, the present inventors have also found that polylactic acid is not sufficiently biodegradable.

[0004] Another biodegradable filter material is paper.For example, International Publication No. 2012012053 discloses a filter with a paper substrate.However, this document teaches that the taste profile of the smoking article that includes a filter with a paper substrate is different from the taste profile of the smoking article that includes a cellulose acetate filter.

[0005] Therefore, there is a need to provide biodegradable filters for smoking articles that have a good taste profile. Summary of the Invention [Problem to be solved by the invention]

[0006] Semivolatile compounds have been found to be important components of taste in smoking articles, such as cigarettes. In this regard, cellulose acetate filters have been found to have high filtering properties for semivolatile compounds. The inventors have found that filters based on natural cellulose fibers do not have such high filtering properties. Therefore, bad taste, such as increased harshness and dryness compared to cellulose acetate filters, may be due to semivolatile compounds such as phenols that are not filtered by cellulose. In this regard, the inventors have found that paper is not selective for filtering phenols, resulting in a worse smoking taste compared to the same cigarette with a cellulose acetate filter.

[0007] The present inventors have further found that phenols can be filtered by impregnating a filtering substrate (i.e., the substrate of at least one segment of a smoking article filter), such as a paper substrate, with an additive for reducing phenols, such as triacetin. The present inventors have also found that the amount of the additive for reducing phenols can be appropriately selected, particularly to achieve a taste similar to that obtained using a cellulose acetate filter. [Means for solving the problem]

[0008] In a first aspect, the present invention provides a filter for a smoking article comprising: a segment comprising a filtration substrate comprising natural cellulose fibers, the filtration substrate comprising a composition comprising an additive for reducing phenols; a wrapper at least partially surrounding the segment; Including, relating to filters.

[0009] Further disclosed is a smoking article comprising a filter of the present invention.

[0010] The present invention further provides a method for manufacturing a filter rod, comprising: providing a filtration substrate comprising natural cellulose fibers; forming a continuous rod from the filtration substrate; adding a composition to the filtering substrate, the composition including an additive for reducing phenols; wrapping a continuous band of packaging material around said continuous rod; cutting the wound continuous rod to obtain filter rods of a predetermined rod length; The present invention is directed to a method, including:

[0011] There is also provided a method of manufacturing a filter segment for a filter of the present invention, comprising the steps of: providing a filter rod obtained by the inventive method for producing a filter rod; cutting the filter rod to obtain filter segments of predetermined segment lengths; A method is disclosed, comprising:

[0012] Further aspects and embodiments of the present invention are disclosed in the dependent claims and can be found from the following description and examples, without however being limited thereby.

[0013] The accompanying drawings illustrate and provide a further understanding of embodiments of the present invention. With reference to the present description, this serves to explain the concepts and principles of the present invention. Further embodiments and many of the advantages described can be derived in conjunction with the drawings. [Brief explanation of the drawings]

[0014] [Figure 1] 1 shows the results of a leakage test in Example 1. [Figure 2] 1 shows the results of a leakage test in Example 1. [Figure 3] Filtration efficiency results are shown. [Figure 4] Selectivity results are shown. [Figure 5] The results of the taste test in Example 3 are shown. [Figure 6] 10 shows the results of a leakage test in Example 4. DETAILED DESCRIPTION OF THE INVENTION

[0015] definition Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0016] The term "phenols" refers to a class of compounds in which one or more hydroxyl groups are attached to an aromatic hydrocarbon group. Examples include phenol, o-cresol, m-cresol, p-cresol, and catechol. Thus, an "additive for reducing phenols" is an additive that can reduce at least one phenol, such as phenol, o-cresol, m-cresol, p-cresol, and / or catechol, when the filter of the present invention is used to filter smoke from combustion or non-combustion applications, as measured, for example, using a standard smoking test.

[0017] As used herein, the terms "filtration substrate comprising natural cellulose fibers" and "filtration substrate" correspond to each other unless the context makes clear otherwise.

[0018] All values ​​provided in this disclosure should be understood to be supplemented by the word "about" unless the context makes clear to the contrary.

[0019] As used herein, wt% should be understood as weight percent. In this disclosure, unless expressly indicated otherwise or clear from the context, all amounts are given in wt% units. In this disclosure, and in a particular embodiment, all amounts given in wt% units add up to 100 wt%. Therefore, unless otherwise indicated or clear from the context, weight percent is calculated in each embodiment by dividing the mass of each component by the total mass.

[0020] In a first aspect, the present invention provides a filter for a smoking article comprising: a segment comprising a filtration substrate comprising natural cellulose fibers, the filtration substrate comprising a composition comprising an additive for reducing phenols; a wrapper at least partially surrounding the segment; Including, relating to filters.

[0021] The filter of the present invention can be composed of one or more segments, and is not particularly limited in this regard, as long as it includes at least one segment containing a filtration substrate including natural cellulose fibers containing a composition including an additive for reducing phenols. Two or more of these segments can also be included in the filter of the present invention, for example, separated by an additional segment. The filter of the present invention can be, for example, a single filter, a dual filter, a triple filter, a single- or multi-cavity filter, or any combination thereof. The additional segment is not particularly limited.

[0022] Preferably, the outer diameter of filters and smoking articles according to the present invention is between about 4 mm and 9 mm, more preferably between about 5 mm and 8 mm, for example about 5.3 mm, about 6.9 mm, or about 7.7 mm.

[0023] Preferably, the overall length of the filter according to the present invention is between about 11 mm and about 40 mm, more preferably between about 17 mm and 30 mm, for example, about 21 mm, about 27 mm, or about 30 mm.

[0024] Preferably, the length of each individual segment of a filter having two or more filter segments according to the present invention is between about 5 mm and about 22 mm.

[0025] In the present invention, particularly in the case of a filtering substrate, the natural cellulose fibers are not particularly limited as long as they are obtained from natural sources, such as plants. Suitable natural cellulose fibers include those obtained from flax, bagasse, esparto, straw, cotton, papyrus, bamboo, jute, hardwood, and softwood. The natural cellulose fibers may be obtained from two or more sources. For example, they may be obtained from several types of wood.

[0026] Furthermore, the filtration substrate is not particularly limited. For example, the filtration substrate can include natural cellulose fibers in woven or nonwoven form, or in filament form, but is preferably in nonwoven or filament form to facilitate filter manufacturing. In some embodiments, the filtration substrate is obtained from wood pulp. In some embodiments, the filtration substrate is substantially free of cellulose acetate fibers, particularly free of cellulose acetate fibers.

[0027] In some embodiments, the filtration substrate can be provided in a sheet form, such as paper. In these embodiments, the filtration substrate, e.g., paper, can be rolled, crimped, corrugated, or folded into a continuous lot. In a preferred embodiment, the filtration substrate is paper, preferably corrugated cardboard, which allows for easy addition and maintenance of the composition containing the additive for reducing phenols, and allows for easy filter production.

[0028] In some embodiments, the filtering substrate can be provided in filament form, such as a woven or nonwoven substrate. In these embodiments, the filtering substrate can be formed into a continuous rod by fluffing the woven substrate and forcing it through a forming funnel under tension. It can also be provided in a randomly oriented form.

[0029] In a preferred embodiment, the filtration substrate is a sheet-like material containing natural cellulose fibers, such as a paper-based material, particularly paper. The sheet-like material may also contain lignin. Furthermore, the sheet-like material may also contain hemicelluloses, such as glucuronoxylan, arabinoxylan, glucomannan, and xyloglucan, and mixtures thereof. Furthermore, the sheet-like material may also contain a filler material, which may be selected from the group consisting of calcium carbonate, kaolin, clay, talc, titanium dioxide, alumina trihydrate, precipitated silica and silicates (PSS), or mixtures thereof.

[0030] According to one embodiment, the sheet-like material, e.g., paper, comprises: - natural cellulose fibers in an amount of 40 to 100% by weight, - lignin in an amount of 0 to 20% by weight, - hemicellulose in an amount of 0 to 20% by weight, - containing a filler material in an amount of 0 to 55% by weight, The weight percent of the sheet material is a percentage based on the total dry basis weight of the sheet material.

[0031] Sheet material: 5 to 130 g / m 2 , preferably 10 to 110 g / m 2 In some embodiments, the sheet material may have a dry basis weight in the range of 25 to 80 g / m 2 , for example 30 to 60 g / m 2 The dry basis weight may be within the range of 1 / 2 to 1 / 4. If the basis weight is too low, the filter may be difficult to manufacture due to its low tensile strength. If the basis weight is too high, the sheet material may be too inflexible and may not provide adequate pressure drop.

[0032] The sheet material may have a filtration rate of up to 36,000 s / 10 ml measured according to DIN 53 137. In a preferred embodiment, the sheet material may have a filtration rate of between 0.1 s / 10 ml and 300 s / 10 ml, for example in the range of 1 s / 10 ml to 5 s / 10 ml, for example 2 s / 10 ml.

[0033] In the filter of the present invention, the additive for reducing phenols is not particularly limited. According to one embodiment, the additive for reducing phenols is selected from triacetin, triethyl citrate (TEC), propylene glycol, polyethylene glycol having a weight-average molecular weight of, for example, 100 to 8,000 daltons, for example, polypropylene glycol having a weight-average molecular weight of, for example, 100 to 8,000 daltons, and mixtures thereof. Preferably, the additive for reducing phenols includes triacetin. More preferably, the additive for reducing phenols is triacetin.

[0034] In the filters of the present invention, the wrapper that at least partially surrounds the segments is not particularly limited and can comprise one or more layers. This can include a partial, or preferably the entire, segment of the entire filter. When more than one segment is included, a wrapper can be provided for more than one, or even all, of the individual segments. The wrapper may be made of a biodegradable material such as a natural cellulosic material, e.g., paper, cardboard, etc., for good biodegradability. It may be printed, embossed, debossed, decorated, etc. One preferred material for the wrapper is paper.

[0035] According to some embodiments, the composition further comprises a binding agent or binder for binding the phenolic-reducing additive to the filtration substrate. The binding agent is added to increase the viscosity of the composition (including the phenolic-reducing additive and the binder), thereby further stabilizing the phenolic-reducing additive in the filter.

[0036] According to some embodiments, the composition contains less than 20 wt. % of a binder, based on the total weight of the composition. That is, the composition includes an additive for reducing phenols and a binder. In particular, the composition consists essentially of, or even consists of, the additive for reducing phenols and the binder. In some preferred embodiments, the composition contains 0.5 to 15 wt. %, preferably 1.5 to 10 wt. %, and particularly preferably 2 to 8 wt. % of a binder, based on the total weight of the composition, for example, 2, 4, or 8 wt. % of a binder. According to some embodiments, the composition consists essentially of, and preferably consists of, an additive for reducing phenols, particularly triacetin, and a binder, particularly cellulose acetate. In such cases, the remainder of the composition to make up 100 wt. % is the additive for reducing phenols. If the amount of binder is too small, there is a risk that the additive for reducing phenols will leak into the wrapper. If the amount of binder is too large, the viscosity will increase too much, making it difficult to manufacture the filter in a filter manufacturing machine. If the amount of binder is too high, the viscosity of the composition containing the binder and the additive for reducing phenols may become too high, making it difficult to manufacture the filter. If the amount of binder is too low, the retention of the additive for reducing phenols on the filtration substrate may be reduced. If the amount of binder is high, the amount of leakage of the additive for reducing phenols, for example, due to storage, may be reduced.

[0037] According to one embodiment, the dynamic viscosity of the composition comprising the additive for reducing phenols and the binder is less than 5,000 mPas when measured at 50°C and a standard pressure of 101,325 Pa. The dynamic viscosity is measured using a rotational viscometer in accordance with ISO 3219:1993. In one preferred embodiment, the dynamic viscosity of the composition comprising the additive for reducing phenols and the binder is between 50 and 1,500 mPas, preferably between 300 and 1,000 mPas, at 50°C and a standard pressure of 101,325 Pa. This method facilitates spraying of the composition for producing the filters of the present invention, avoiding more complicated dosing methods such as direct injection.

[0038] In one embodiment, the binder is present in an amount of less than 7 wt. % based on the total weight of the filtration substrate and the composition comprising the additive for reducing phenols and the binder. In a preferred embodiment, the binder is present in an amount of 0.2 to 5.0 wt. %, preferably 0.4 to 4.0 wt. %, more preferably 0.6 to 3.3 wt. %, and particularly preferably 0.8 to 2.6 wt. % based on the total weight of the filtration substrate and the composition comprising the additive for reducing phenols and the binder.

[0039] In one embodiment, the binder is cellulose acetate. The cellulose acetate is not particularly limited. In one embodiment, the degree of substitution of cellulose acetate is between 2.1 and 2.9, preferably between 2.1 and 2.6, e.g., about 2.4. A suitable degree of substitution improves affinity with the filtration substrate and the additive for reducing phenols, particularly triacetin, thereby reducing leakage of the additive for reducing phenols, particularly triacetin, into the wrapper. Since cellulose acetate is preferably dissolved in the additive for reducing phenols, particularly triacetin, before being added to the filtration substrate, the shape of the cellulose acetate is not particularly limited and may be in the form of fibers, such as short fibers, particles, flakes, etc. In particular, triacetin can dissolve cellulose acetate as a binder, resulting in good reduction of phenols.

[0040] As used herein, the degree of substitution (DS) of a polymer refers to the average number of substituents attached per base unit in the case of condensation polymers or per monomer unit in the case of addition polymers. In particular, in the case of cellulose acetate, the degree of substitution of cellulose acetate refers to the average number of substituents attached per monomer unit.

[0041] According to one embodiment, the ratio of the binder to the total weight of the filtering substrate is 0.5% or more, preferably 0.8% or more, particularly preferably 1% or more. The inventors have found that the binder in the filter of the present invention not only functions as a carrier for the additive for reducing phenols, but also as a thickener for the composition containing the additive for reducing phenols, i.e., increases the viscosity of the composition, thereby improving the retention of the composition in the filtering substrate and reducing leakage.

[0042] According to one embodiment, the composition is present in an amount such that the filtration selectivity of the filter segment for phenol relative to total particulate material is at least 2, where filtration selectivity S X (in the case of phenol) is the formula:

number

[0043] According to some embodiments, the filter may include additional granules, such as charcoal and / or flavor particles, the form and amount of which are not particularly limited and may include amounts, sizes, and other conventional parameters typically used in filters for smoking articles, such as cigarette filters.

[0044] According to some embodiments, the filters of the present invention comprise at least one segment comprising a filtration substrate comprising natural cellulose fibers, e.g., paper, comprising triacetin and cellulose acetate, and a wrapper at least partially surrounding the segment. According to some embodiments, the filters of the present invention consist essentially of, or consist of, a filtration substrate comprising natural cellulose fibers, e.g., paper, triacetin, and cellulose acetate, and a wrapper, e.g., a paper wrapper. do.

[0045] According to some embodiments, the composition is present in an amount of 10 to 35 wt % based on the total weight of the filtration substrate and composition, i.e., the composition includes an additive for reducing phenols and optionally a binder, particularly the composition includes an additive for reducing phenols and a binder. According to some preferred embodiments, the composition may be present in an amount of 10 to 13 wt %, 20 to 24 wt %, or 30 to 35 wt %, for example, between about 10 wt %, 20 to 21 wt %, or 30 to 32 wt %, based on the total weight of the filtration substrate and composition.

[0046] In some embodiments, the additive for reducing phenols is present in an amount between 9 and 35% by weight, based on the total weight of the filtering substrate and the composition including the additive for reducing phenols and the binder. In some preferred embodiments, the additive for reducing phenols is present in an amount between 9 and 11% by weight, between 19 and 21% by weight, or between 28 and 32% by weight, based on the total weight of the filtering substrate and the composition including the additive for reducing phenols and the binder. A higher amount of the additive for reducing phenols can more effectively reduce phenols in smoke containing these compounds. However, if the amount is too high, there is a risk of leakage of the additive for reducing phenols. If the amount of the additive for reducing phenols is too low, phenols will not be sufficiently reduced.

[0047] Further disclosed is a smoking article comprising the filter of the present invention. In the smoking article, the additional components other than the filter are not particularly limited and may include components normally used in smoking articles.

[0048] In addition to the filter, the smoking article can include, for example, an aerosol-generating substrate, such as a tobacco rod in a cigarette, or a substrate containing tobacco or nicotine that generates an aerosol in a non-combustion application, such as when the tobacco or nicotine is only heated but not burned. If the smoking article is, for example, a cigarette, there can be tipping paper connecting the tobacco rod and the filter.

[0049] 1. A method for manufacturing a filter rod, comprising: providing a filtration substrate comprising natural cellulose fibers; forming a continuous rod from the filtration substrate; adding a composition to the filtering substrate, the composition reducing phenols; and adding an additive to cause the reaction to proceed; wrapping a continuous band of packaging material around said continuous rod; Optionally, cutting the wound continuous rod to obtain filter rods of predetermined rod lengths; A method is also disclosed, including:

[0050] Preferably, the method is carried out in this order. The method of the present invention can be used in particular to manufacture the filter of the present invention or at least one segment thereof. Accordingly, each of the features discussed with respect to the filter also applies to the method of the present invention for manufacturing a filter rod.

[0051] The steps of providing a filtering substrate; forming a continuous rod from the filtering substrate, which is not particularly limited in terms of size, circumference, etc. and may be similar to that in a conventional filter for a smoking article; adding a composition to the filtering substrate; winding the continuous rod; and cutting the wound continuous rod are not particularly limited and may be performed similar to that in a conventional method of manufacturing a filter for a smoking article.

[0052] In some embodiments, the filtration substrate may be provided in sheet form, and in these embodiments, the filtration substrate may be formed into a continuous rod by, but not limited to, rolling, crimping, corrugating, or folding.

[0053] In another embodiment, the filtration substrate can be provided in the form of a filament, for example, in the form of a woven substrate.In these embodiments, the woven substrate can be fluffed and passed through a forming funnel under tension to form a continuous rod from the filtration substrate.When the filtration substrate is provided in the form of a filament, it can be formed into a continuous rod using a common machine, for example, using the Turmalin filter manufacturing machine of Hauni Maschinenbau AG, as described in WO2009 / 080368, WO2009 / 093051, WO2013 / 068337, WO2013 / 164624 and WO2013 / 164623.

[0054] In some embodiments, the step of adding the composition to the filtering substrate occurs during or after the step of forming the filtering substrate into a rod. In some embodiments, the step of adding the composition to the filtering substrate occurs during or after the step of winding the filtering substrate into a rod. In these cases, the composition can be injected, for example, as a fluid into the continuous dot or a segment thereof, as described, for example, in U.S. Patent No. 5,387,285.

[0055] According to some embodiments, the step of adding the composition to the filtering substrate occurs before the step of forming the filtering substrate into a rod.

[0056] According to some embodiments, the step of adding the composition to the filtering substrate comprises spraying the composition onto the filtering substrate. The spraying method is not particularly limited. Spraying is particularly useful when the composition is added before forming a (continuous) rod from the filtering substrate.

[0057] In some embodiments, the composition is heated before or during the step of adding the composition to the filtering substrate. This step is preferably performed when the composition includes an additive for reducing phenols and a binder. The composition can be heated to a temperature between 40°C and 60°C, for example, about 50°C, and added at that temperature. Preferably, the composition is added under standard pressure of 101325 Pa.

[0058] There is further provided a method for producing a filter segment of a filter of the present invention, comprising the steps of: Providing a filter rod obtained by the method of the present invention for producing a filter rod; cutting the filter rod to obtain filter segments of predetermined segment lengths; A method is disclosed, comprising:

[0059] Preferably, the method is carried out in this order. This method for producing filter segments can be used to produce segments of the filters of the present invention, among others. Accordingly, each of the features discussed with respect to the filters also applies to the method of the present invention for producing filter segments.

[0060] The cutting of the filter rod is not particularly limited and can be carried out as usual in the production of filter segments. An appropriate cutting length may be, for example, between 80 mm and 150 mm, for example, about 108 mm or about 120 mm.

[0061] The above-described embodiments may be combined in any suitable manner. Further possible embodiments and implementations of the invention also include combinations of features not expressly mentioned above or below with respect to the examples of the invention. In particular, those skilled in the art may also add individual aspects as improvements or additions to each basic form of the invention. [Example]

[0062] The present invention will now be described in detail with reference to the following examples, which are illustrative only and are not intended to limit the scope of the present invention.

[0063] Example 1 Cigarette filters were prepared by dropping various amounts of cellulose acetate and triacetin (GTA, glycerin triacetate) as an additive for reducing phenols onto a filter substrate made of paper sheets at 22°C, which were then crimped into rod shapes and wrapped in a standard paper wrapper. The degree of substitution of the cellulose acetate was 2.4. The paper sheets had a weight of 39 g / m. 2 The filter rod had a basis weight of 126 mm, a thickness of 120 μm, and a filtration rate of 3.5 s / 10 ml, measured according to DIN 53 137. The filter rod had a length of 126 mm and a diameter of 24.2 mm and was cut into six filters of 21 mm length.

[0064] The various amounts of added components and the amount of binder present in the different sample compositions are shown in Table 1 below.

[0065] [Table 1]

[0066] The prepared filters were stored at 22°C, standard pressure, and 60% relative humidity for 10 minutes. After storage for 1 day and 1 month, the loss of additive was monitored as a weight difference. In this regard, it is noted that the loss of liquid was already visible on the cardboard on which the filter was stored.

[0067] These results are shown in Table 2, where the leakage amount corresponds to the weight difference measured for each sample.

[0068] [Table 2]

[0069] The leakage results for 10 days of storage are also shown in Figures 1 and 2.

[0070] As can be seen, a higher amount of cellulose acetate reduces leakage of the additive. Samples 6, 8, 9, and 10 had less than 10% leakage after one month of storage, with Samples 8, 9, and 10 performing particularly well when compared to the other samples.

[0071] The inventors have determined that leakage after one month is less than 10% when cellulose acetate is present in an amount of 0.6% by weight or more, based on the total weight of the filtration substrate and the composition comprising triacetin and cellulose acetate. The inventors have also determined that leakage after one month is notably reduced when cellulose acetate is present in an amount of 0.8% by weight or more, based on the total weight of the filtration substrate and the composition comprising triacetin and cellulose acetate.

[0072] The inventors have determined that a ratio of cellulose acetate of 0.8% by weight or more based on the total weight of the filtration substrate (excluding the weights of triacetin and cellulose acetate) results in less than 10% leakage after one month. The inventors have also determined that a ratio of 1.0% by weight or more results in the well-known reduction in leakage after one month.

[0073] Example 2 Filtration efficiency was measured for phenol, o-cresol, and total particulate matter (TPM). To determine the filtration efficiency of filter samples 1-9 (Samples 1-9) against two control filters of substantially the same dimensions, filter samples 1-9 and control samples 1 and 2 were connected to tobacco rods with tipping paper and tested in a standard smoking test, in which the filtration efficiency of phenol, o-cresol, and total particulate matter (TPM) was determined by measuring the amount of phenol, o-cresol, and TPM on the Cambridge filter.

[0074] Control filter 1 (Control 1) was a standard cellulose acetate filter made from a tow of cellulose acetate fibers with a denier per filament of 2.5 and a total denier of 31,000. The fibers were Y-shaped. Triacetin was added to the cellulose acetate fibers in an amount of 8% by weight, based on the total weight of the cellulose acetate fibers and triacetin. Control filter 2 (Control 2) was made from the same paper sheet material as filter samples 1-9, but without the additive and binder for reducing phenolics.

[0075] These results are shown in FIG.

[0076] Furthermore, the filtration selectivity of phenol and o-cresol was calculated using the above formula, and the results are shown in Figure 4.

[0077] As can be seen from Figures 3 and 4, the addition of triacetin, especially the addition of triacetin and cellulose acetate, can increase the filtration efficiency and selectivity for phenol and o-cresol, achieving efficiencies and selectivities similar to and even superior to those achieved with cellulose acetate filters. The addition of cellulose acetate reduces the selectivity for phenol and o-cresol.

[0078] Example 3 The cigarettes produced in Example 2 using filter samples 1, 2, and 3 were subjected to a sensory evaluation by a panel of five adults and compared with the cigarettes produced in Example 2 using a control filter.

[0079] After smoking, the panel rated the irritation / harshness of the cigarettes while smoking. The results are shown in Figure 5. As can be seen, the addition of triacetin reduced the irritation of the smoke, resulting in a smoother smoke that was rounder and less harsh. Therefore, the smoothness of the smoke can be controlled by the amount of additive added to reduce phenols.

[0080] Example 4 Three filter samples according to the present invention and a control filter (Control 3) were prepared to evaluate additive leakage over a longer period than in Example 1. These filter samples and the control filter were prepared using the same paper sheet material as the filtration substrate, to which different amounts of additive composition were added. The additive composition consisted of triacetin and cellulose acetate only. No additive composition was added to the control filter (Control 3). In this example, the amount of triacetin added to the paper sheet material was determined by the weight ratio of cellulose acetate to the filtration substrate and the amount of cellulose acetate in the composition. These amounts are shown in Table 3 below.

[0081] [Table 3]

[0082] Samples 11-13 and the control filter were manufactured in Indonesia, shipped by air to Germany, and stored upright on cardboard trays at 22°C, standard pressure, and 50% relative humidity for 180 days. After 180 days of storage, stains were visible on the cardboard trays of Samples 11, 12, and 13, corresponding to the amount of additive leaked during the storage period. Grayscale photographs of the cardboard trays of Samples 11-13 and Control 3 are shown in Figures 6a-6d, where Figure 6a shows Control 3, Figure 6b shows Sample 11, Figure 6c shows Sample 12, and Figure 6d shows Sample 13. It is easy to see that Samples 12 and 13 leaked additive, and that it was much less than Sample 11. This confirms the observations in Example 1.

[0083] Reference example 1 Film samples of different materials were cut to a size with a significant weight, placed in soil, and stored in a controlled room at 30°C and 90% relative humidity for 70 days, during which time their weight loss was measured after 10, 20, 30, and 70 days to determine biodegradability. The results are shown in Table 3, where the weight is expressed as a percentage of the original weight of the sample.

[0084] [Table 4]

[0085] As can be seen from Table 3, the sample that decomposed most rapidly was the polyvinyl alcohol sample, followed by The cellulose samples degraded at a much faster rate than the cellulose acetate, polylactic acid, polycaprolactone, and polybutylene succinate samples. The polyvinyl alcohol samples degraded completely after 10 days of storage, while the remaining samples remained at over 90% of their original weight after the same storage period. The cellulose samples degraded completely after 70 days of storage, while the cellulose acetate, polylactic acid, polycaprolactone, and polybutylene succinate samples remained at over 95% of their original weight after the same storage period.

[0086] This indicates that, in particular, polylactic acid and cellulose acetate are not fully biodegradable, whereas cellulose is fully biodegradable.

Claims

1. 1. A filter for a smoking article comprising: a segment comprising a filtration substrate comprising natural cellulose fibers, the filtration substrate comprising a composition comprising an additive for reducing phenols; a wrapper at least partially surrounding the segment; Including, filters.

2. 10. The filter of claim 1, wherein the composition further comprises a binder for binding the phenolic reducing additive to the filtration substrate.

3. 3. The filter of claim 2, wherein the composition comprises less than 20% by weight of the binder, based on the total weight of the composition.

4. 4. The filter of claim 2 or claim 3, wherein the binder is cellulose acetate.

5. The filter according to any one of claims 2 to 4, wherein the ratio of the binder to the total weight of the filtering substrate is 0.5% or more.

6. The filter according to any one of claims 2 to 5, wherein the binder is contained in an amount of 0.6% or more based on the total weight of the filtering substrate and the composition.

7. The composition is present in an amount such that the filter segment has a filtration selectivity for phenol relative to total particulate material of at least 2, wherein the filtration selectivity S is defined by the formula: [Equation 1] where E[TPM] is the filtration efficiency of the filter segment for total particulate material and E[phenol] is the filtration efficiency of the filter segment for phenol.

8. 8. The filter of claim 1, wherein the additive for reducing phenols is selected from triacetin, triethyl citrate (TEC), propylene glycol, polyethylene glycol, polypropylene glycol, and mixtures thereof.

9. The filter according to any one of claims 1 to 8, wherein the composition is contained in an amount of 10 to 35 wt % based on the total weight of the filtering substrate and the composition.

10. A smoking article comprising the filter according to any one of claims 1 to 9.

11. 1. A method for manufacturing a filter rod, comprising: providing a filtration substrate comprising natural cellulose fibers; forming a continuous rod from the filtering substrate; adding a composition to the filtering substrate, the composition including an additive for reducing phenols; wrapping a continuous band of packaging material around said continuous rod; cutting the wound continuous rod to obtain filter rods of a predetermined rod length; A method comprising:

12. 12. The method of claim 11, wherein the step of adding the composition to the filtration substrate occurs during or after the step of forming a rod from the filtration substrate.

13. 13. The method of claim 11 or claim 12, wherein the step of adding the composition to the filtration substrate occurs during or after the step of wrapping around the rod.

14. 12. The method of claim 11, wherein the step of adding the composition to the filtration substrate occurs before the step of forming a rod from the filtration substrate.

15. The method of any one of claims 11 to 14, wherein the step of adding the composition to the filtering substrate comprises spraying the composition onto the filtering substrate.

16. The method of any one of claims 11 to 15, wherein the composition is heated before or during the step of adding the composition to the filtering substrate.

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