Filter for a smoking or aerosol generating article and article equipped with said filter

Abstract

The present invention provides a filter for a smoking or aerosol generating article and an article containing same, the filter comprising: a filter element containing a filter material, said filter material being wrapped in a paper wrapper, wherein the filter element contains a solid additive represented by Chemical Formula 1: [Chemical Formula 1] wherein, R1 is a C1-C12 hydrocarbon group that is optionally substituted with one or more substituents selected from -OR3, -COOR3, -COR3, -NHCOR3, and -NHCOC(NHR3)CH2COOH, and wherein R3 is H or a C1-C6 alkyl group; and R2 is a C1-C16 hydrocarbon group that is optionally substituted with one or more substituents selected from -OR4, -COR4, and -OCOR4, and wherein R4 is H or a C1-C11 alkyl group.

Description

[0001] FILTER FOR A SMOKING OR AEROSOL GENERATING ARTICLE AND ARTICLE

[0002] EQUIPPED WITH SAID FILTER

[0003] Technical Field

[0004] This invention relates to a filter for a smoking or aerosol generating article, as well as to the smoking or aerosol generating article equipped with said filter.

[0005] Background Art

[0006] Acetate fibers or acetate tow have been widely used as filter material for smoking or aerosol generating articles such as filtered cigarettes or heated tobacco sticks. In recent years, the use of biodegradable materials in place of acetate fibers has been promoted to reduce waste load on the environment. Cellulose is one such material that is being considered but it has a lower phenol filtration efficiency than acetate fibers. Since it is desirable to maintain good phenol filtration efficiency for safety and improved sensory quality (also referred to as phenol scavenging), biodegradable materials such as cellulose are yet to be adopted widely.

[0007] There have been attempts to improve the filtration efficiency of filter elements by including phenol-scavenging additives in the filter element. For example, WO 2019 / 149742 Al describes a filter element to which triacetin is added to reduce phenols. However, being liquid, triacetin and other such liquid additives tend to leak out of the filter element during storage. Leakage from the filter element is problematic as it can negatively affect phenol filtration efficiency, cause other components such as dyes in the wrapping paper to dissolve and generally appear unsightly. Where liquid additives are used, additional protective measures such as a liquid repellent layer are needed (see e.g., WO 2022 / 250135 Al). Attempts to reduce leakage include using gel-like phenol- scavenging additives with reduced tendency to flow (see e.g., WO 2023 / 112885 Al). However, even these are said to have some leakage and so a liquid repellent layer is still recommended.

[0008] Summary of the Invention

[0009] The inventors have conducted extensive studies and have found that certain ester-group containing solid compounds are capable of acting as phenol scavengers. By including such a solid additive in a filter, phenol reduction can be achieved without the disadvantages associated with liquid and gellike additives. Leakage of the additive is effectively eliminated and there is no need to include additional components such as liquid repellent layers or gelling agents and the like which, like polymeric substances, can increase tackiness of the fiber surface, potentially causing clumping and other blockages which may affect air-flow resistance in unpredictable ways. The present invention is based on this surprising discovery and relates to the following embodiments:

[0010] [1] A filter for a smoking or aerosol generating article, the filter comprising: a filter element containing a filter material, said filter material being wrapped in a paper wrapper, wherein the filter element contains a solid additive represented by Chemical Formula 1 :

[0011] [Chemical Formula 1] wherein, R1is a C1-C12 hydrocarbon group that is optionally substituted with one or more substituents selected from -OR3, -COOR3, -COR3, -NHCOR3, and -NHCOC(NHR3)CH2COOH, and wherein R3is H or a Ci-Ce alkyl group; and

[0012] R2is a Ci-Cie hydrocarbon group that is optionally substituted with one or more substituents selected from -OR4, -COR4, and -OCOR4, and wherein R4is H or a Ci-Cn alkyl group.

[0013] [2] A smoking or aerosol-generating article comprising the filter according to [1],

[0014] [3] Use of a solid additive represented by Chemical Formula 1 as defined above for [1] as a phenol scavenger in the filter of a smoking or aerosol-generating article.

[0015] Detailed Description

[0016] The present invention will be described in detail by way of embodiments and examples. However, the invention is not limited to the following embodiments and examples, and various modifications are possible as long as they do not depart from the scope of the invention as defined by the appended claims.

[0017] <Filter>

[0018] An embodiment of the present invention is a filter for a smoking or aerosol generating article. The filter includes: a filter element containing a filter material, said filter material being wrapped in a paper wrapper.

[0019] The filter may be a plain filter including one filter segment, or it may be a multi-segment filter including a plurality of filter segments such as a dual filter or a triple filter, etc. The filter may have any shape suitable for use as a filter. For example, the filter generally has a cylindrical shape and may include sections such as cavities or recesses that each have a hollow (void) circumferential cross section.

[0020] The shape of the cross section of the filter that is orthogonal to the longitudinal axis of the filter is preferably substantially circular, and its diameter can be appropriately changed according to the size of the product. The diameter is generally 4.0 mm or more, preferably 4.5 mm or more, and more preferably 5.0 mm or more and is generally 9.0 mm or less, preferably 8.5 mm or less, and more preferably 8.0 mm or less. When the cross section is not circular, the diameter is assumed to be the same as the diameter of a circle having the same area as the area of the cross section, and the diameter of this circle is used.

[0021] The circumferential length of the cross section of the filter that is orthogonal to the longitudinal axis of the filter can be appropriately changed according to the size of the product used. The circumferential length is generally 12.5 mm or more, preferably 14.0 mm or more, and more preferably 16.0 mm or more and is generally 28.0 mm or less, preferably 27.0 mm or less, and more preferably 25.0 mm or less.

[0022] The length of the filter in the longitudinal direction can be appropriately changed according to the size of the product. The length may be 5 mm or more, 10 mm or more, 15 mm or more, 17.5 mm or more, or 20.0 mm or more and may be 40 mm or less, 35 mm or less, 32.5 mm or less, or 30.0 mm or less.

[0023] Air-flow resistance per 120 mm of the filter in its axial direction can be adjusted as desired for a particular product and is generally 100 mmfhO or more, preferably 150 mmbhO or more, and more preferably 200 mmbhO or more and is generally 800 mmbhO or less, preferably 700 mmbhO or less, and more preferably 600 mmbhO or less. The air-flow resistance of the filter is measured, for example, using a filter air-flow resistance measurement device manufactured by Cerulean according to an ISO standard method (ISO 6565). The air-flow resistance of the filter is the difference in pressure between one of the end faces (a first end face) and the other end face (a second end face) when air is caused to flow at a predetermined flow rate (17.5 mL / s) with no air transmission through the side surface of the filter. The unit of the air-flow resistance is generally mml O. As for the relation between the air-flow resistance of the filter and the length of the filter, they are known to be proportional to each other in a length range for commonly used filters (length: 5 mm to 200 mm). When the length is doubled, the air-flow resistance of the filer is doubled.

[0024] <Filter element>

[0025] The filter element contains filter material wrapped in a paper wrapper.

[0026] The ester-group containing solid compounds described herein are capable of acting as phenol scavengers so will improve phenol filtering efficiency irrespective of the filter material to which they are applied. As such, the filter material of the present invention may be any material that is known in the art for preparing filters for smoking or aerosol generating articles.

[0027] Preferably, the filter material contains a biodegradable material to reduce waste load on the environment. Since biodegradable materials can have reduced phenol filtering ability as compared to conventionally used acetate fibers, their use has been limited to date. This invention makes it possible to use a biodegradable material as the filter element and yet maintain acceptable phenol filtering ability. Examples of the biodegradable material that can be used for the present invention include cellulose, polylactic acid, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), polylactic acid / polycaprolactone copolymers, polyglycolic acid, polylactic acid / polyether copolymers, butanediol / long-chain dicarboxylic acid copolymers, polybutylene adipate / terephthalate, polytetramethylene adipate-co-terephthalate, polyethylene terephthalate succinate, polybutylene succinate, polybutylene succinate adipate, and polyvinyl alcohol. Of these, cellulose is most preferred. The filter material may comprise cellulose obtained from natural sources such as wood or cotton, or recycled cellulose such as rayon. The biodegradable material is preferably cellulose present in a paper, tow, and / or a non-woven form, also referred to herein as a paper filter.

[0028] The filter material containing cellulose can be paper formed from wood pulp. No particular limitation is imposed on the type of wood pulp, and wood pulp such as coniferous pulp or broadleaf pulp can be used. The type of paper used for the filter is also not limited, and gathered paper, pleated paper, crimped paper, crepe paper, nonwoven fabric, shredded paper, etc. may be used. A paper production method may be a wet method or a dry method, and any of them may be appropriately selected and used for preparing the filter material.

[0029] The filter material can be in the form of a bundle of sheet-shaped filter elements. In a particular example of the form of the paper filter, paper having a corrugated structure including a plurality of valleys and ridges is gathered in a bundle. When the paper having the corrugated structure is used, the paper is disposed such that the direction of the valleys (or ridges) is parallel to the longitudinal direction of the filter rod. When the paper having the corrugated structure is used as the paper for the filter element forming the paper filter, no particular limitation is imposed on the average distance (which may be referred to also as the "average pitch") between the valleys or ridges in the corrugated shape of the paper filter. The average distance is generally 0.5 mm or more and preferably 1.0 mm or more and is generally 5.0 mm or less and preferably 4.0 mm or less. No particular limitation is imposed on the average depth of the valleys of the corrugated shape of the paper filter, and the average depth is generally 0.1 mm or more and preferably 0.2 mm or more and is generally 1.2 mm or less and preferably 1.0 mm or less. The paper having the corrugated structure can be produced by subjecting a flat raw material sheet with no corrugated shape to creping for forming ridges and valleys.

[0030] No particular limitation is imposed on the thickness of the raw material sheet, and the thickness is generally 20 pm or more, preferably 25 pm or more, and more preferably 30 pm or more and is generally 140 pm or less, preferably 130 pm or less, and more preferably 120 pm or less. No particular limitation is imposed on the basis weight of the raw material sheet. The basis weight is generally 20 gsm or more and preferably 25 gsm or more and is generally 120 gsm or less, preferably 80 gsm or less, and more preferably 45 gsm or less. The basis weight can be controlled by adjusting the content of the pulp and the content of a filler or adjusting the processing conditions for the wet-type paper machine.

[0031] No particular limitation is imposed on the width of the raw material sheet. The width of the raw material sheet is generally 50 mm or more, preferably 100 mm or more, and more preferably 170 mm or more and is 300 mm or less, preferably 250 mm or less, and more preferably 230 mm or less. The width of the raw material sheet is its length in a direction perpendicular to the longitudinal direction in which the ridges and valleys in the paper having the corrugated structure are continuously arranged, i.e., the length in a direction perpendicular to a direction corresponding to the longitudinal direction the filter element obtained by processing the paper having the corrugated structure. The paper wrapper that is used to wrap the filer material can be any suitable paper wrapper known in the art. The paper wrapper may include at least one seam including an adhesive. The adhesive may include a hot-melt adhesive. The adhesive may include polyvinyl alcohol.

[0032] No particular limitation is imposed on the material of the paper wrapper, and a well-known material may be used. The plug wrap paper may contain a filler such as calcium carbonate. No particular limitation is imposed on the thickness of the paper wrapper, and the thickness is generally 20 pm or more and preferably 30 pm or more. The thickness is generally 140 pm or less, preferably 130 pm or less, and more preferably 120 pm or less. No particular limitation is imposed on the basis weight of the paper wrapper, and the basis weight is generally 20 gsm or more, preferably 22 gsm or more, and more preferably 23 gsm or more. The basis weight is generally 100 gsm or less, preferably 95 gsm or less, and more preferably 90 gsm or less.

[0033] <Solid additive>

[0034] The filter element of the invention contains a solid additive that can act as a phenol -scavenger, thereby reducing the amount of phenol components that would ordinarily pass through the filter if the additive was not present. In the present invention, “solid” means that the additive is a physical solid at 25°C at a pressure of 1 atm. That is, the additive itself is solid in accordance with the ordinary meaning of solid as opposed to a substance that exhibits solid-like properties merely because it is confined in a three-dimensional structure of some kind.

[0035] In the present invention, the solid additive is a compound represented by Chemical Formula 1 : [Chemical Formula 1] wherein,

[0036] R1is a C1-C12 hydrocarbon group that is optionally substituted with one or more substituents selected from -OR3, -COOR3, -COR3, -NHCOR3, and -NHCOC(NHR3)CH2COOH, and wherein R3is H or a Ci-Ce alkyl group; and

[0037] R2is a C1-C16 hydrocarbon group that is optionally substituted with one or more substituents selected from -OR4, -COR4, and -OCOR4, and wherein R4is H or a C1-C11 alkyl group.

[0038] In Chemical Formula 1, the C1-C12 hydrocarbon group of R1and the C1-C16 hydrocarbon group of R2can be independently selected from a straight, branched and / or cyclic alkyl group, a phenyl group, a phenylalkyl group, or a phenylalkenyl group. The C1-C12 hydrocarbon group of R1that is optionally substituted can be selected from methyl, ethyl, isopropyl, n-heptyl, n-nonyl, n-decyl, n- undecyl, n-dodecyl, phenyl, phenylethyl and phenyl ethenyl. The C1-C16 hydrocarbon group of R2that is optionally substituted can be selected from methyl, ethyl, n-propyl, n-butyl, hexadecyl, p- menthyl, phenyl, and phenylethyl. R1can be a C1-C12 hydrocarbon group that is optionally substituted with one or more substituents selected from -OH, -OCH3, -OCH2CH3, -COOCH3, - COCH3, -COCH2CH3, -COOH, -COOCH2CH3, -NHCOCH3, and -NHCOC(NHCH2CH2C(CH3)3)CH2COOH. R2can be a C1-C16 hydrocarbon group that is optionally substituted with one or more substituents selected from -OH, -OCH3, -OCH2CH3, -COH, and -OCOC11H23.

[0039] In one aspect of the invention the solid additive is represented by Chemical Formula 2: [Chemical Formula 2] wherein m is an integer from 0 to 11. In Chemical Formula 2, m can be an integer from 6 to 10.

[0040] In another aspect of the invention the solid additive is represented by Chemical Formula 3:

[0041] [Chemical Formula 3] wherein p is an integer from 1 to 12, and R5and R6are independently a Ci-Ce alkyl. In Chemical Formula 3, p can be 10 or 12, and R5and R6can be C1-C3 alkyl.

[0042] In another aspect of the invention the solid additive is represented by Chemical Formula 4:

[0043] [Chemical Formula 4] wherein q is 0 or 1, R7is a C1-C16 alkyl group, and R8and R9are independently H or a Ci to Ce alkyl group. In this aspect the solid additive can also be represented by Chemical Formula 4-1, Chemical Formula 4-2 or Chemical Formula 4-3: [Chemical Formula 4-1]

[0044] [Chemical Formula 4-3] wherein in each of Chemical Formulae 4-1, 4-2 and 4-3, R7is Ci to Cs alkyl, preferably methyl or ethyl, and R8is H or methyl, and in Chemical Formulae 4-1 and 4-2, R9is H or methyl. The solid additive preferably has a melting point of 30°C or higher, more preferably 40°C or higher, and still more preferably 50°C or higher. Having a higher melting point allows the filter, or the smoking or aerosol generating article containing said filter, to be stored at elevated temperatures while still maintaining the benefits that a solid additive provides. From a processing standpoint, the solid additive preferably has a melting point of 100°C or lower, more preferably 90°C or lower, and still more preferably or 80°C or lower. A lower melting point requires less energy to melt the additive. This is particularly useful if it is desired that the additive be applied in a molten state to the filter. Any of the preferred lower limits for melting point can be combined with any of the preferred upper limits of the melting point. For example, it is preferred that the additive has a melting point of 30°C to 100°C, preferably 40°C to 100°C, and still more preferably 50°C to 100°C.

[0045] The solid additive preferably has a boiling point of at least 260°C, more preferably 270°C or higher, and still more preferably 280°C or higher. Additives with higher boiling points tend to be less volatile and therefore are more suitable when the filter or smoking or aerosol generating article containing same are to be stored for long periods of time.

[0046] The solid additive is preferably one that is already recognised by a regulatory body as being safe for humans, such as those appearing on one or more databases maintained by the US Food and Drug Administration or the European Food and Safety Authority. Selecting an additive from such a database has the benefit of reducing phenol content with an additive that is already considered safe for human use.

[0047] Examples of additives that satisfy one or more of the above preferred features include monocaprylin (CAS 26402-26-6), ethyl vanillate (CAS 617-05-0), dimethyl dodecanedi oate (CAS 1731-79-9), phenethyl cinnamate (CAS 103-53-7), neotame (CAS 165450-17-9), ethyl 2- benzylidene-3-oxobutanoate (CAS 620-80-4), L-menthyl lactate (CAS 59259-38-0), dimethyl tetradecanedioate (CAS 5024-21-5), monomenthyl succinate (CAS 77341-67-4), monocaprin (CAS 26402-22-2), diethyl terephthalate (CAS 636-09-9), monolaurin (CAS 142-18-7), hexadecyl lactate (CAS 35274-05-6), methyl vanillate (CAS 3943-74-6), vanillin acetate (CAS 881-68-5), methyl 3,4-dimethoxybenzoate (CAS 2150-38-1), phenethyl salicylate (CAS 87-22-9), ethyl vanillin isobutyrate (CAS 188417-26-7), butyl 4-hydroxybenzoate (CAS 94-26-8), methyl 2- acetamidobenzoate (CAS 2719-08-6), trilaurin (CAS 538-24-9), and ethyl 3,4-dimethoxybenzoate (CAS 3943-77-9). Particularly preferred are ethyl 3,4-dimethoxybenzoate, ethyl vanillate, dimethyl dodecanedi oate, phenethyl cinnamate, neotame, and ethyl 2-benzylidene-oxobutanoate for their ability to greatly reduce phenol content.

[0048] The solid additive is present in an amount such that an observable reduction in phenol content can be observed as compared to an otherwise comparable filter that does not contain the solid additive. Any suitable test for determining phenol-reducing efficiency, such as that described below in the example, can be used to determine an appropriate amount of the compound based on the desired use (e.g. amount of tobacco; type of smoking or aerosol generating article; etc.). That said, the solid additive is preferably present in an amount of 1 wt.% or more with respect to the weight of the filter material that is present in the filter. The solid additive can be present in an amount of 2 wt.% or more, 3 wt.% or more, 5 wt.% or more, or 10 wt.% or more with respect to the weight of the filter material. Increasing the amount of solid additive with respect to the filter material increases the amount of phenol that can be removed. The solid additive is preferably present in an amount of 35 wt.% or less, 30 wt.% or less and 25 wt.% or less with respect to the weight of the filter material. Reducing the amount of solid additive reduces air-flow resistance of the filter. Any of the preferred lower limits for the amount of the solid additive can be combined with any of the preferred upper limits to achieve the desired balance between phenol removal and air-flow resistance. For example, the solid additive can be present in an amount of 1 to 35 wt.% with respect to the weight of the filter material, or it can be present in an amount of 5 to 35 wt.% or 5 to 25 wt.%. When the amount of the solid additive is within the above ranges, phenol filtration efficiency increases and air-flow resistance is not significantly affected.

[0049] <Method for producing the filter>

[0050] No particular limitation is imposed on the method for producing the filter, and the filter can be produced by any suitable method in the art for producing filters. For example, the filter can be produced by using paper obtained by subjecting wood pulp to papermaking and shaping the paper into a filter rod. Specifically, for example, the paper obtained by papermaking is subjected to, for example, crimping or creping to corrugate the paper, and the paper having the corrugated structure is gathered in a bundle and wrapped with a plug wrap paper to form a rod-shaped filter. The rodshaped filter is cut to a desired length, and a paper filter can thereby be produced.

[0051] The paper machine used may be a well-known paper machine such as a cylinder paper machine, an inclined Tanmo machine, a Fourdrinier machine, etc., and these paper machines may be appropriately combined according to the required characteristics. A dry production method for resin-bonded nonwoven fabrics, thermal-bonded nonwoven fabrics, or spun-laced nonwoven fabrics may be appropriately used.

[0052] A filter other than the paper filter can be produced by shaping a raw material into a sheet and form the filter according to the method for producing the paper filter. A filter can also be produced by gathering a fibrous raw material in a bundle, wrapping the raw material with a plug wrap paper to form a rod-shaped filter, and cutting the rod-shaped filter to a desired length.

[0053] The solid additive of Chemical Formula 1 may be added in any step of the filter making process. For example, the solid additive may be added to the filter material before or after creping but before the filter material is shaped into a rod. The solid additive may be added to the filter material by any means known in the art. For example, the solid additive can be added to the filter material in the form of a solution or dispersion containing the solid additive whereupon the solvent or dispersing medium is allowed to evaporate. The solution or dispersion may be fed using a pressure pump or may be sprayed. Alternatively, the solid additive can be added to the filter element in a molten state (e.g., by pressure pump, nozzle (incl. spray) as well as solution or dispersion of the solid additive) and then allowed to cool and solidify back to the solid state.

[0054] < Smoking or aerosol generating article >

[0055] In the present invention, the “smoking or aerosol generating article” is a generic term for inhalation articles that allow the user to enjoy a flavor such as tobacco flavor. More specific examples of the smoking or aerosol generating article include a combustion-type article such as a tobacco rod (e.g. a cigarette) in which a flavor source is combusted to provide the flavor to the user and a noncombustion heating-type article such as an electric cigarette or a heat-not-burn device in which a flavor source is heated without being combusted to provide a flavored aerosol to the user.

[0056] No particular limitation is imposed on the tobacco rod so long as it has a well-known form. Generally, the tobacco rod includes a tobacco filler wrapped with a wrapping paper. No particular limitation is imposed on the tobacco filler, and the tobacco filler used may be a well-known tobacco filler such as shredded tobacco or a reconstituted tobacco sheet.

[0057] The content of moisture in an ordinary tobacco filler such as shredded tobacco included in the tobacco rod is, for example, 10 to 15% by weight and preferably 11 to 13% by weight. When the moisture content is as described above, the occurrence of stains on the wrapping paper is prevented, and the machinability during production of the flavor inhalation article is improved.

[0058] When the flavor inhalation article is a non-combustion heating-type flavor inhalation article, the tobacco filler may contain an aerosol-source material. The aerosol-source material is a material that generates an aerosol when heated, and examples thereof include glycerin, propylene glycol, and mixtures thereof.

[0059] No particular limitation is imposed on the material of the wrapping paper wrapped around the tobacco filler, and a well-known material can be used. The wrapping paper may contain a filler such as calcium carbonate.

[0060] EXAMPLES

[0061] The present invention will now be described more specifically by way of examples. However, the invention is not limited to the description of the following examples so long as they do not depart from the scope of the invention.

[0062] <Test for ability to filter out phenols>

[0063] Cigarette samples were produced as follows. First, a paper filter having a length of 27 mm and a diameter of 7.7 mm was prepared. Specifically, first, a corrugated paper sheet (basis weight: 40 g / m2) was folded such that a plurality of airflow paths extending from one end to the other end were formed, and the folded paper sheet was wrapped with a plain paper. The resulting filter was cut to a length of 120 mm to thereby produce a filter rod. The air-flow resistance of the filter rod was adjusted to 400 mmH20, and the diameter of the filter was adjusted to 7.7 mm. The obtained filter rod was cut to a length of 27 mm, and 25 mg of a solid additive as listed in Table 1 below was added using a micro-syringe. Then commercial tobacco rods and the filters were joined together to produce cigarette samples.

[0064] The cigarette samples were subjected to a smoking test under the following conditions and analyzed. An automatic smoking machine (Cerulean SM410) was used to automatically smoke one of the cigarette samples under the conditions of a smoking volume of 17.5 mL / sec, a smoking time of 2 sec / puff, and a smoking frequency of 1 puff / min. Tobacco particulate matter (TPM) in the tobacco smoke was collected by a Cambridge filter (Borgwaldt 44 mm). The amount of the TPM was measured based on the difference in the mass of the Cambridge filter before and after smoking. Then the Cambridge filter was immersed in 10 mL of a phenol extraction solvent placed in a screw tube bottle (t-butyl methyl ether as solvent containing 10.7 pg / mL o-chlorophenol as internal standard), and the bottle was shaken to thereby obtain an analysis sample. 1 pL of the obtained analysis sample was collected by a microsyringe and analyzed by gas-chromatograph- mass spectrometry (GC-MSD: Gas Chromatography -Mass Selective Detector). The GC used was Agilent G7890A manufactured by Agilent Technologies Inc., and the MSD used was Agilent 5795C manufactured by Agilent Technologies Inc.

[0065] For each of the cigarette samples, the amount of TPM per cigarette and the amount of phenols in the tobacco smoke were measured using the method described above. The amount of phenols in the tobacco smoke was divided by the amount of TPM, and the quotient was normalized using the value for a paper filter with no additive added thereto to evaluate the ability of the additive to filter out phenols. The average of three evaluation result values is provided in Table 1 below.

[0066] Table 1. Mean relative delivery of phenol per TPM for various additives.

[0067]

[0068] As can be seen from Table 1, the solid additives used in Examples 1 to 21 have the ability to reduce phenol content and therefore are capable of acting as phenol scavengers in accordance with the present invention. The additives used in Comparative Examples 1 and 2, on the other hand, while being ester-group containing compounds, are not according to the present invention and do not exhibit suitable ability to reduce phenol content.

Claims

CLAIMS1. A filter for a smoking or aerosol generating article, the filter comprising: a filter element containing a filter material, said filter material being wrapped in a paper wrapper, wherein the filter element contains a solid additive represented by Chemical Formula 1 :[Chemical Formula 1]wherein,R1is a C1-C12 hydrocarbon group that is optionally substituted with one or more substituents selected from -OR3, -COOR3, -COR3, -NHCOR3, and -NHCOC(NHR3)CH2COOH, and wherein R3is H or a Ci-Ce alkyl group; andR2is a Ci-Cie hydrocarbon group that is optionally substituted with one or more substituents selected from -OR4, -COR4, and -OCOR4, and wherein R4is H or a Ci-Cn alkyl group.

2. The filter according to claim 1, wherein the solid additive has a melting point of 40°C or higher.

3. The filter according to claims 1 or 2, wherein the solid additive has a melting point of 100°C or lower.

4. The filter according to any one of claims 1 to 3, wherein the solid additive has a boiling point greater than 260°C.

5. The filter according to any one of claims 1 to 4, wherein the C1-C12 hydrocarbon group of R1and the C1-C16 hydrocarbon group of R2are independently selected from a straight, branched and / or cyclic alkyl group, a phenyl group, a phenylalkyl group, or a phenylalkenyl group.

6. The filter according to claim 5, wherein the C1-C12 hydrocarbon group of R1that is optionally substituted is selected from methyl, ethyl, isopropyl, n-heptyl, n-nonyl, n-decyl, n- undecyl, n-dodecyl, phenyl, phenylethyl and phenyl ethenyl.

7. The filter according to claim 5 or 6, wherein the C1-C16 hydrocarbon group of R2that is optionally substituted is selected from methyl, ethyl, n-propyl, n-butyl, hexadecyl, p-menthyl, phenyl, and phenyl ethyl.

8. The filter according to any one of claims 1 to 7, wherein R1is a C1-C12 hydrocarbon group that is optionally substituted with one or more substituents selected from -OH, -OCH3, -OCH2CH3, -COOCH3, -COCH3, -COCH2CH3, -COOH, -COOCH2CH3, -NHCOCH3, and -NHCOC(NHCH2CH2C(CH3)3)CH2COOH.

9. The filter according to any one of claims 1 to 8, wherein R2is a C1-C16 hydrocarbon group that is optionally substituted with one or more substituents selected from -OH, -OCH3, -OCH2CH3, -COH, and -OCOC11H23.

10. The filter according to claim 1, wherein the solid additive is selected from: monocaprylin , ethyl vanillate, dimethyl dodecanedi oate, phenethyl cinnamate, neotame, ethyl 2-benzylidene-3- oxobutanoate, L-menthyl lactate, dimethyl tetradecanedioate, monomenthyl succinate,monocaprin, diethyl terephthalate, monolaurin, hexadecyl lactate, methyl vanillate, vanillin acetate, methyl 3,4-dimethoxybenzoate, phenethyl salicylate, ethyl vanillin isobutyrate, butyl 4- hydroxybenzoate, methyl 2-acetamidobenzoate, trilaurin, and ethyl 3,4-dimethoxybenzoate, preferably wherein the additive is selected from ethyl 3,4-dimethoxybenzoate, ethyl vanillate, dimethyl dodecanedi oate, phenethyl cinnamate, neotame, and ethyl 2-benzylidene- oxobutanoate.

11. The filter according to any one of claims 1 to 10, wherein the additive is present in an amount of from 1 wt.% to 35 wt.% with respect to the total weight of the filter.

12. The filter according to any one of claims 1 to 11, wherein the filter material is a biodegradable material comprising at least one selected from cellulose, polylactic acid, poly(3- hydroxybutyrate-co-3 -hydroxyhexanoate), polylactic acid / poly caprolactone copolymers, polyglycolic acid, polylactic acid / polyether copolymers, butanediol / long-chain dicarboxylic acid copolymers, polybutylene adipate / terephthalate, polytetramethylene adipate-co-terephthalate, polyethylene terephthalate succinate, polybutylene succinate, polybutylene succinate adipate, and polyvinyl alcohol.

13. The filter according to claim 12, wherein the filter material comprises cellulose obtained from natural sources or recycled cellulose, preferably in a paper, tow, and / or a non-woven form.

14. A smoking or aerosol-generating article comprising the filter according to any one of claims 1 to 13.

15. Use of a solid additive represented by Chemical Formula 1 in the filter of a smoking or aerosol-generating article for reducing phenol content in smoke or aerosol:[Chemical Formula 1]wherein,R1is a C1-C12 hydrocarbon group that is optionally substituted with one or more substituents selected from -OR3, -COOR3, -COR3, -NHCOR3, and -NHCOC(NHR3)CH2COOH, and wherein R3is H or a Ci-Ce alkyl group; andR2is a Ci-Cie hydrocarbon group that is optionally substituted with one or more substituents selected from -OR4, -COR4, and -OCOR4, and wherein R4is H or a Ci-Cn alkyl group.

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