Activated carbon, filter for smoking article and smoking article including the same

Abstract

Disclosed is activated carbon having an excellent ability to remove vapor phase components. According to one aspect, there is provided activated carbon including a micropore having a pore diameter of less than 2 nm, wherein a ratio of the micropores is from 70 vol % to 80 vol % based on a total pore volume of the activated carbon, and the activated carbon has a BET specific surface area of 2,000 m2 / g or more.

Description

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to Korean Patent Application No. 10-2024-0123116, filed on Sep. 10, 2024; and Korean Patent Application No. 10-2025-0119193, filed on Aug. 26, 2025, the disclosure of which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates to activated carbon, and in particular, to activated carbon, a filter for a smoking article, and a smoking article including the same.BACKGROUND ART

[0003] In general, activated carbon is widely used to remove vapor phase components and also used in tobacco filters to reduce vapor phase components in tobacco smoke.

[0004] Filter manufacturers or tobacco companies are conducting research to reduce vapor phase components such as aldehyde in tobacco smoke.PRIOR ART DOCUMENTSPatent Documents

[0005] (Patent Document 1) Korean Patent No. 10-0669490 (published on Jan. 16, 2007).DISCLOSURETechnical Problem

[0006] One aspect of the present disclosure is to provide activated carbon having an excellent ability to remove vapor phase components including carbonyls and volatile organic compounds (VOCs).

[0007] Another aspect of the present disclosure is to provide activated carbon that reduces taste and aroma intensity and irritation of a smoking article.

[0008] Still another aspect of the present disclosure is to provide a method for preparing the activated carbon.

[0009] Yet another aspect of the present disclosure is to provide a filter for a smoking article, the filter including the activated carbon.

[0010] Still yet another aspect of the present disclosure is to provide a smoking article including the filter for a smoking article.

[0011] Objects of the present disclosure are not limited to the above-mentioned objects, and other objects and advantages of the present disclosure not mentioned will be understood by the following description, and more clearly understood by embodiments of the present disclosure. In addition, it may be readily understood that objects and advantages of the present disclosure may be embodied by means described in the specification and combinations thereof.Technical Solution

[0012] According to a first aspect of the present disclosure, there is provided activated carbon including a micropore having a pore diameter of less than 2 nm, wherein a ratio of the micropores is from 70 vol % to 80 vol % based on a total pore volume of the activated carbon, and the activated carbon has a BET specific surface area of 2,000 m2 / g or more.

[0013] According to a second aspect of the present disclosure, in the first aspect, the micropore may have a volume of 0.8 cm3 / g to 1.1 cm3 / g.

[0014] According to a third aspect of the present disclosure, in the first or second aspect, the activated carbon further includes a mesopore having a pore diameter of 2 nm or more and 50 nm or less, and a ratio of the mesopores may be from 15 vol % to 25 vol % based on a total pore volume of the activated carbon.

[0015] According to a fourth aspect of the present disclosure, in the third aspect, the mesopore may have a volume of 0.2 cm3 / g to 0.4 cm3 / g.

[0016] According to a fifth aspect of the present disclosure, in any one of the first to fourth aspects, the activated carbon further includes a macropore having a pore diameter of more than 50 nm, and a ratio of the macropores may be from 1 vol % to 5 vol % based on a total pore volume of the activated carbon.

[0017] According to a sixth aspect of the present disclosure, in the fifth aspect, the macropore may have a volume of 0.01 cm3 / g to 0.10 cm3 / g.

[0018] According to a seventh aspect of the present disclosure, in any one of the first to sixth aspects, the activated carbon may have a BET specific surface area of 2,200 m2 / g or more.

[0019] According to an eighth aspect of the present disclosure, in any one of the first to seventh aspects, the activated carbon may have a total pore volume of 1.0 cm3 / g or more.

[0020] According to a ninth aspect of the present disclosure, there is provided a filter for a smoking article, the filter including the activated carbon of any one of the first to eighth aspects.

[0021] According to a tenth aspect of the present disclosure, there is provided a smoking article comprising: a filter portion; and a medium portion disposed on one side of the filter portion, wherein the filter portion comprises the filter for a smoking article according to the ninth aspect.

[0022] According to an eleventh aspect of the present disclosure, the filter portion includes a first portion and a second portion that is different from the first portion, and the second portion is closer to the medium portion than the first portion, and the second portion may include the filter for a smoking article in the tenth aspect.

[0023] The technical solutions do not list all the features of the present disclosure, and may be combined with several embodiments of the present specification. Various features of the present disclosure and corresponding advantages and effects will be understood in more detail with reference to specific description stated below.Advantageous Effects

[0024] According to one aspect of the present disclosure, activated carbon having an excellent ability to remove vapor phase components including carbonyls and volatile organic compounds (VOCs) can be obtained, and at the same time, activated carbon that reduces taste and aroma intensity and irritation of a smoking article can be obtained.

[0025] Specific effects of the present disclosure in addition to the above-described effects will be described together while describing specific details for implementing the disclosure hereinafter. In addition, effects of the present disclosure are not limited to the effects mentioned above, and may be readily embodied by means described in the specification and combinations thereof.BRIEF DESCRIPTION OF DRAWINGS

[0026] FIG. 1 illustrates a smoking article according to one embodiment of the present disclosure.

[0027] FIG. 2 illustrates a smoking article according to another embodiment of the present disclosure.BEST MODE

[0028] In the present specification, singular forms include plural forms as well, unless the context clearly indicates otherwise.

[0029] In the present specification, the term “comprise” and / or “comprising” specifies the presence of mentioned shapes, steps, numbers, operations, members, elements and / or groups thereof, and does not exclude the presence or addition of one or more other shapes, steps, numbers, operations, members, elements and / or groups thereof.

[0030] In the present specification, “at least one of a, b and c” may include a, b or c alone, or may include a combination of two or more selected from the group consisting of a, b and c.

[0031] The term “connection” used in the present specification is a concept that not only means that certain members are directly connected, but also includes a case where these members are indirectly connected with another member further interposed therebetween.

[0032] When multiple embodiments are described in the present specification, each embodiment may be combined unless there is a particular description to the contrary. Herein, effects of the present disclosure may be defined to include not only the effects obtained from each embodiment itself, but also the effects occurring as respective embodiments are organically combined. For example, even when embodiments 1 and 2 are each independently described in the present specification, embodiments 1 and 2 may be organically combined with each other unless the context clearly indicates otherwise, and effects of the present disclosure may include the effects occurring as embodiments 1 and 2 are combined.

[0033] In the present specification, a numerical range indicated by using a term “to” represents a numerical range including values described before and after the term respectively as a lower limit value and an upper limit value. When numerical values as upper and lower limits of any numerical range are each disclosed as multiple numbers, the numerical range disclosed in the present specification may be understood as any numerical range having any one of the multiple lower limit values and any one of the multiple upper limit values respectively as a lower limit value and an upper limit value. For example, when a to b, or c to d is described in the present specification, it may be understood that a or more and b or less, a or more and d or less, c or more and d or less, or c or more and b or less is described.

[0034] In the present specification, a “pore diameter” may be defined to mean an average diameter of pores.

[0035] According to one aspect of the present disclosure, there is provided activated carbon including a micropore having a pore diameter of less than 2 nm, wherein a ratio of the micropores is from 70 vol % to 80 vol % based on a total pore volume of the activated carbon, and the activated carbon has a BET specific surface area of 2,000 m2 / g or more. According to one aspect of the present disclosure, by adjusting the ratio of the micropores and the BET specific surface area of the activated carbon within the above-mentioned numerical range, activated carbon having an excellent ability to remove vapor phase components including carbonyls and volatile organic compounds (VOCs) may be obtained, and at the same time, activated carbon that reduces taste and aroma intensity and irritation of a smoking article may be obtained.

[0036] Hereinafter, constitutions of the present disclosure will be described in more detail.1. Activated CarbonMicropore

[0037] In the present specification, a diameter of the micropore is defined to be less than 2 nm, and specifically, more than 0 nm and less than 2 nm.

[0038] The activated carbon according to the present disclosure includes micropores configured to effectively adsorb vapor phase components. Specifically, by the activated carbon including the micropores, vapor phase components are effectively bound to the pore structure in the activated carbon, and the vapor phase components generated during smoking may be effectively removed.

[0039] In some embodiments of the present disclosure, the micropore may have a diameter of more than 0 nm and less than 2 nm, 0.1 nm to 2 nm, 0.2 nm to 2 nm, 0.3 nm to 2 nm, 0.4 nm to 2 nm, or 0.5 nm to 2 nm. According to some embodiments of the present disclosure, the pore size increases by an appropriate level compared to the molecular size of the vapor phase components by adjusting the diameter of the micropore within the above-mentioned numerical range, and the vapor phase components may be strongly bound to the pore structure. For example, the diameter of the micropore may be measured in accordance with a density functional theory (DFT).

[0040] Meanwhile, the ratio of the micropores means a ratio of the volume of the micropores with respect to the total pore volume of the activated carbon.

[0041] In some embodiments of the present disclosure, the ratio of the micropores is from 70 vol % to 80 vol %, and specifically, 71 vol % to 79 vol %, 72 vol % to 78 vol %, 73 vol % to 77 vol %, 74 vol % to 76 vol %, 75 vol % to 76 vol %, or 75.9 vol % to 76 vol % based on the total pore volume of the activated carbon. According to some embodiments of the present disclosure, the vapor phase components are strongly bound to the pore structure by adjusting the ratio of the micropores within the above-mentioned numerical range, and the ability to remove the vapor phase components including carbonyls and volatile organic compounds (VOCs) may be further improved.

[0042] In some embodiments of the present disclosure, when (i) the diameter of the micropore satisfies the range of more than 0 nm and less than 2 nm, 0.1 nm to 2 nm, 0.2 nm to 2 nm, 0.3 nm to 2 nm, 0.4 nm to 2 nm, or 0.5 nm to 2 nm, and (ii) the ratio of the micropores satisfies the range of 70 vol % to 80 vol %, 71 vol % to 79 vol %, 72 vol % to 78 vol %, 73 vol % to 77 vol %, 74 vol % to 76 vol %, 75 vol % to 76 vol %, or 75.9 vol % to 76 vol % based on the total pore volume of the activated carbon, the vapor phase components are strongly bound to the pore structure, and the ability to remove the vapor phase components including carbonyls and volatile organic compounds (VOCs) may be further improved.

[0043] In some embodiments of the present disclosure, the micropore may have a volume of 0.8 cm3 / g to 1.1 cm3 / g, 0.85 cm3 / g to 1.1 cm3 / g, 0.9 cm3 / g to 1.0 cm3 / g, or 0.97 cm3 / g to 1.0 cm3 / g. According to some embodiments of the present disclosure, the vapor phase components are strongly bound to the pore structure by adjusting the volume of the micropores within the above-mentioned numerical range, so that the ability to remove the vapor phase components including carbonyls and volatile organic compounds (VOCs) may be further improved. For example, the volume of the micropores may be measured using nitrogen adsorption, a mercury porosimetry technique, an H-K (Horvath-Kawazoe) method or a density functional theory (DFT).Mesopore

[0044] In the present specification, the “mesopore” is defined to mean a pore having a pore diameter of 2 nm or more and 50 nm or less.

[0045] The activated carbon according to the present disclosure may further include a mesopore, which is any one of factors affecting the BET specific surface area of the activated carbon. Specifically, by adjusting the volume of the mesopores, the ratio of the mesopores with respect to the total pore volume, and the like, the BET specific surface area of the activated carbon may change, and accordingly, performance of adsorbing the vapor phase components may also change.

[0046] Meanwhile, the ratio of the mesopores means a ratio of the volume of the mesopores with respect to the total pore volume of the activated carbon. For example, the volume of each pore may be measured using nitrogen adsorption, a mercury porosimetry technique, an H-K (Horvath-Kawazoe) method or a density functional theory (DFT).

[0047] In some embodiments of the present disclosure, the ratio of the mesopores may be from 15 vol % to 25 vol %, 16 vol % to 24 vol %, 17 vol % to 23 vol %, 18 vol % to 22 vol %, 19 vol % to 21 vol %, or 20.5 vol % to 21 vol % based on the total pore volume of the activated carbon. According to some embodiments of the present disclosure, the BET specific surface area of the activated carbon may be increased to an appropriate level by adjusting the ratio of the mesopores within the above-mentioned numerical range, and accordingly, the ability to remove the vapor phase components including carbonyls and volatile organic compounds (VOCs) may be further improved.

[0048] In some embodiments of the present disclosure, the mesopore may have a volume of 0.2 cm3 / g to 0.4 cm3 / g, 0.21 cm3 / g to 0.39 cm3 / g, 0.22 cm3 / g to 0.38 cm3 / g, 0.23 cm3 / g to 0.37 cm3 / g, 0.24 cm3 / g to 0.30 cm3 / g, 0.25 cm3 / g to 0.29 cm3 / g, or 0.26 cm3 / g to 0.28 cm3 / g. According to some embodiments of the present disclosure, the BET specific surface area of the activated carbon may be increased to an appropriate level by adjusting the volume of the mesopores within the above-mentioned numerical range, and accordingly, the ability to remove the vapor phase components including carbonyls and volatile organic compounds (VOCs) may be further improved. For example, the volume of the mesopores may be measured using nitrogen adsorption, a mercury porosimetry technique, an H-K (Horvath-Kawazoe) method or a density functional theory (DFT).Macropore

[0049] In the present specification, the “macropore” is defined to mean a pore having a pore diameter of more than 50 nm. For example, the upper limit of the diameter of the pore included in the macropore may be 100 nm or less, 150 nm or less, or 200 nm or less.

[0050] The activated carbon according to the present disclosure may further include a macropore, which is any one of factors affecting the BET specific surface area of the activated carbon. Specifically, by adjusting the volume of the macropores, the ratio of the macropores with respect to the total pore volume, and the like, the BET specific surface area of the activated carbon may change, and accordingly, performance of adsorbing the vapor phase components may also change.

[0051] Meanwhile, the ratio of the macropores means a ratio of the volume of the macropores with respect to the total pore volume of the activated carbon. For example, the volume of each pore may be measured using nitrogen adsorption, a mercury porosimetry technique, an H-K (Horvath-Kawazoe) method or a density functional theory (DFT).

[0052] In some embodiments of the present disclosure, the ratio of the macropores may be from 1 vol % to 5 vol %, 2 vol % to 4 vol %, 3 vol % to 4 vol %, or 3.6 vol % to 4 vol % based on the total pore volume of the activated carbon. According to some embodiments of the present disclosure, the BET specific surface area of the activated carbon may be increased to an appropriate level by adjusting the ratio of the macropores within the above-mentioned numerical range, and accordingly, the ability to remove the vapor phase components including carbonyls and volatile organic compounds (VOCs) may be further improved.

[0053] In some embodiments of the present disclosure, the macropore may have a volume of 0.01 cm3 / g to 0.10 cm3 / g, 0.02 cm3 / g to 0.09 cm3 / g, 0.03 cm3 / g to 0.08 cm3 / g, 0.04 cm3 / g to 0.07 cm3 / g, or 0.05 cm3 / g to 0.06 cm3 / g. According to some embodiments of the present disclosure, the BET specific surface area of the activated carbon may be increased to an appropriate level by adjusting the volume of the macropores within the above-mentioned numerical range, and accordingly, the ability to remove the vapor phase components including carbonyls and volatile organic compounds (VOCs) may be further improved.Relationship Between Components

[0054] In some embodiments of the present disclosure, the total sum of the volume of the macropores and the volume of the mesopores may be from 0.21 cm3 / g to 0.50 cm3 / g, 0.22 cm3 / g to 0.45 cm3 / g, 0.23 cm3 / g to 0.40 cm3 / g, 0.25 cm3 / g to 0.38 cm3 / g, 0.26 cm3 / g to 0.37 cm3 / g, 0.27 cm3 / g to 0.36 cm3 / g, 0.28 cm3 / g to 0.35 cm3 / g, 0.29 cm3 / g to 0.34 cm3 / g, 0.30 cm3 / g to 0.33 cm3 / g, or 0.31 cm3 / g to 0.33 cm3 / g. According to some embodiments of the present disclosure, by adjusting the total sum of the volume of the macropores and the volume of the mesopores within the above-mentioned numerical range, activated carbon having an excellent ability to remove the vapor phase components including carbonyls and volatile organic compounds (VOCs) may be obtained, and at the same time, activated carbon that reduces taste and aroma intensity and irritation of a smoking article may be obtained.Properties

[0055] The BET (Brunauer, Emmett, Teller) specific surface area of the activated carbon according to the present disclosure may be a factor affecting the ability of the activated carbon to remove vapor phase components. Specifically, the BET specific surface area may be a property derived from combinations of the ratio of the micropores, the ratio of the mesopores and the ratio of the macropores. Accordingly, the BET specific surface area may not be achieved when at least one of the combinations of the ratio of the micropores, the ratio of the mesopores and the ratio of the macropores does not satisfy the numerical range.

[0056] The activated carbon according to the present disclosure may have a BET specific surface area of 2,000 m2 / g or more, specifically 2,200 m2 / g or more, and more specifically, 2,200 to 2,500 m2 / g, 2,200 m2 / g to 2,400 m2 / g or 2,200 m2 / g to 2,300 m2 / g. According to some embodiments of the present disclosure, by adjusting the BET specific surface area of the activated carbon within the above-mentioned numerical range, activated carbon having an excellent ability to remove the vapor phase components including carbonyls and volatile organic compounds (VOCs) may be obtained, and at the same time, activated carbon that reduces taste and aroma intensity and irritation of a smoking article may be obtained.

[0057] In some embodiments of the present disclosure, the activated carbon may have a total pore volume of 1.0 cm3 / g or more, 1.1 cm3 / g or more or 1.2 cm3 / g or more, and specifically, 1.2 cm3 / g to 1.5 cm3 / g, 1.2 cm3 / g to 1.4 cm3 / g, 1.2 cm3 / g to 1.3 cm3 / g, or 1.27 cm3 / g to 1.3 cm3 / g. According to some embodiments of the present disclosure, by adjusting the total pore volume of the activated carbon within the above-mentioned numerical range, activated carbon having an excellent ability to remove the vapor phase components including carbonyls and volatile organic compounds (VOCs) may be obtained, and at the same time, activated carbon that reduces taste and aroma intensity and irritation of a smoking article may be obtained.

[0058] In the present specification, an average particle diameter of a particle may be defined as a particle diameter (D50) when a cumulative percentage becomes 50% in a volume-based particle size distribution curve when measured using a laser diffraction particle size distribution measurement device. For example, in order to measure an average particle diameter of the particle, the particles to be measured are dispersed in a dispersion medium, and then introduced to a commercially available laser diffraction particle size measurement device (for example: Microtrac S3500), and when the particles pass through the laser beam, a difference in the diffraction pattern depending on the particle size may be measured to calculate the particle size distribution.

[0059] In some embodiments of the present disclosure, the activated carbon may have an average particle diameter (D50) of 0.18 mm or more, 0.20 mm or more, 0.30 mm or more, 0.40 mm or more, or 0.50 mm or more; 0.60 mm or less, 0.50 mm or less, 0.40 mm or less, 0.30 mm or less, or 0.20 mm or less; or any one of the plurality of lower limits or more and any one of the plurality of upper limits or less. According to some embodiments of the present disclosure, by adjusting the average particle diameter of the activated carbon within the above-mentioned numerical range, the activated carbon is uniformly distributed on the surface or inside of a filter element, and the ability to remove the vapor phase components including carbonyls and volatile organic compounds (VOCs) may be further improved.

[0060] In some embodiments of the present disclosure, the activated carbon may have iodine adsorption capacity of 1,840 mg / g or more, 1,850 mg / g or more or 1,853 mg / g or more in accordance with KS M 1802-a. According to some embodiments of the present disclosure, by adjusting the iodine adsorption capacity of the activated carbon within the above-mentioned numerical range, activated carbon having an excellent ability to remove the vapor phase components including carbonyls and volatile organic compounds (VOCs) may be obtained, and at the same time, activated carbon that reduces taste and aroma intensity and irritation of a smoking article may be obtained.Preparation Method

[0061] According to another aspect of the present disclosure, there may be provided a method for preparing the activated carbon.

[0062] The method for preparing the activated carbon according to the present disclosure may include: (S1) carbonizing a coconut shell; (S2) preparing a porous structure by primarily activating the carbonized coconut shell; (S3) preparing preliminary activated carbon by pulverizing the porous structure; and (S4) secondarily activating the preliminary activated carbon.

[0063] Specifically, hydrocarbons and volatiles included in the coconut shell may be removed by carbonizing the coconut shell in step (S1). In some examples, step (S1) may include performing heating for about 3 days to 5 days, or for 4 days at 500° C. to 550° C., and cooling for 10 hours to 14 hours at about 15° C. to 25° C.

[0064] Specifically, step (S2) may be a step of preparing a porous structure by activating the carbonized coconut shell. By preparing the porous structure, vapor phase components including carbonyls and volatile organic compounds may be effectively adsorbed to the pore structure included in the porous structure.

[0065] In some examples, step (S2) may include introducing the carbonized coconut shell and liquid water that is a first activating agent to a reactor, and then performing primary activation for 1 hour to 3 hours at 700° C. to 900° C.

[0066] In some examples, the content of the first activating agent may be from 90 parts by weight to 110 parts by weight, 95 parts by weight to 105 parts by weight, 97 parts by weight to 103 parts by weight, 98 parts by weight to 102 parts by weight, or 99 parts by weight to 100 parts by weight with respect to 100 parts by weight of the carbonized coconut shell. Specifically, by adjusting the content of the first activating agent within the above-mentioned numerical range, the BET specific surface area of the activated carbon may be further increased, further improving the effect of removing the vapor phase components.

[0067] In some examples, the first activating agent may be liquid water, water vapor or carbon dioxide, and specifically, liquid water. Specifically, by using the liquid water as the first activating agent, the BET specific surface area of the activated carbon may be further increased, further improving the effect of removing the vapor phase components.

[0068] Specifically, step (S3) may be a step of further increasing adsorption performance for the vapor phase components by increasing the BET specific surface area of the activated carbon through pulverizing the porous structure. For example, the size of the preliminary activated carbon may be adjusted to 30 mesh×80 mesh when pulverizing the porous structure.

[0069] Specifically, by secondarily activating the preliminary activated carbon in step (S4), the BET specific surface area of the activated carbon may be further increased and the ratio of the micropores may be increased to an appropriate level.

[0070] In some embodiments of the present disclosure, step (S4) may include introducing the preliminary activated carbon and a second activating agent to a reactor, and then performing secondary activation for 4 hours to 7 hours at 900° C. to 1000° C. Specifically, in step (S4), the activation temperature may be from 910° C. to 990° C., 920° C. to 980° C., 930° C. to 970° C., 940° C. to 960° C., or 950° C. to 955° C., and the activation time may be from 5 hours to 7 hours or 5 hours to 6 hours. According to some embodiments of the present disclosure, by adjusting the activation temperature and the activation time of step (S4) within the above-mentioned numerical range, the BET specific surface area of the activated carbon may be further increased, and the ratio of the micropores may be increased to an appropriate level. Accordingly, activated carbon having an excellent ability to remove the vapor phase components including carbonyls and volatile organic compounds (VOCs) may be obtained, and at the same time, activated carbon that reduces taste and aroma intensity and irritation of a smoking article may be obtained.

[0071] In some embodiments of the present disclosure, the second activating agent may be liquid water, water vapor or carbon dioxide, and specifically, liquid water. Specifically, by using the liquid water as the second activating agent, the BET specific surface area of the activated carbon may be further increased, further improving the effect of removing the vapor phase components.

[0072] In some embodiments of the present disclosure, the content of the second activating agent may be from 105 parts by weight to 115 parts by weight, 107 parts by weight to 113 parts by weight, 109 parts by weight to 111 parts by weight, or 110 parts by weight to 111 parts by weight with respect to 100 parts by weight of the preliminary activated carbon. According to some embodiments of the present disclosure, by adjusting the content of the second activating agent within the above-mentioned numerical range, activated carbon having an excellent ability to remove the vapor phase components including carbonyls and volatile organic compounds (VOCs) may be obtained, and at the same time, activated carbon that reduces taste and aroma intensity and irritation of a smoking article may be obtained.

[0073] For example, the BET specific surface area of the activated carbon may change by each independently controlling factors such as the (i) presence or absence of the secondary activation step, (ii) activation temperature of the secondary activation step, (iii) activation time of the secondary activation step, (iv) type of the second activating agent, (v) content of the second activating agent and (vi) process condition (temperature and time) of the primary activation step in the method for preparing the activated carbon.

[0074] For example, the ratio of the micropores based on the total pore volume of the activated carbon may change by each independently controlling factors such as the (i) presence or absence of the secondary activation step, (ii) activation temperature of the secondary activation step, (iii) activation time of the secondary activation step, (iv) type of the second activating agent, (v) content of the second activating agent and (vi) process condition (temperature and time) of the primary activation step in the method for preparing the activated carbon.

[0075] When at least any one of the factors of (i) to (vi) is outside the appropriate range, the BET specific surface area of the activated carbon and the ratio of the micropores may not be achieved.2. Filter for Smoking Article

[0076] In the present specification, a “smoking article” may mean any smokeable product or any product capable of providing a smoking experience regardless of whether it is based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes. For example, the smoking article may include smokeable products such as cigarettes, cigars and cigarillos. As another example, the smoking article may include a combustible smoking article or a heated smoking article.

[0077] According to still another aspect of the present disclosure, there is provided a filter for a smoking article, the filter including the activated carbon of some embodiments.

[0078] The filter for a smoking article according to the present disclosure may perform a filtering function for smoke and / or aerosol generated from a medium portion to be described later.

[0079] In some examples, the filter for a smoking article is not particularly limited, but may specifically further include at least one filter element of cellulose acetate and paper sheets.

[0080] In some embodiments of the present disclosure, the surface or inside of the filter element may be filled with the activated carbon. Specifically, the activated carbon may be arranged between fibers forming the filter element, or may be disposed in a form of being evenly distributed on the fibers.

[0081] In some examples, the filter for a smoking article may have an overall length of 12 mm to 18 mm or 12 mm to 15 mm with respect to the longitudinal direction.

[0082] In some examples, the content of the activated carbon is not particularly limited, but may specifically be from 13 mg to 24 mg based on the overall length of the filter for a smoking article.3. Smoking Article

[0083] In the present specification, “upstream” or “upstream direction” may mean a direction away from a mouth of a smoker, and “downstream” or “downstream direction” may mean a direction approaching a mouth of a smoker. The terms upstream and downstream may be used to describe relative positions of elements forming a smoking article.

[0084] In the present specification, the “longitudinal direction” may mean a direction corresponding to the longitudinal axis of a smoking article.

[0085] According to still another aspect of the present disclosure, there is provided a smoking article including: a filter portion; and a medium portion disposed on one side of the filter portion, wherein the filter portion includes the filter for a smoking article of some embodiments.

[0086] Hereinafter, constitutions of the present disclosure will be described in more detail with reference to FIGS. 1 and 2.

[0087] FIG. 1 illustrates the smoking article according to one embodiment of the present disclosure.

[0088] Referring to FIG. 1, the smoking article 100 according to the present disclosure includes a filter portion 10 and a medium portion 20. Specifically, the filter portion 10 and the medium portion 20 may be continuously arranged along the longitudinal direction. More specifically, the medium portion 20 may be located upstream, and the filter portion 10 may be located downstream.

[0089] The filter portion 10 according to the present disclosure may filter smoke and / or aerosol generated from the medium portion 20. Specifically, the filter portion 10 may include the filter for a smoking article including the activated carbon of some embodiments.

[0090] The medium portion 20 according to the present disclosure is disposed on one side of the filter portion 10. Specifically, the medium portion 20 may include a medium generating smoke and / or aerosol when combusted.

[0091] In the present specification, the “medium” is not particularly limited, and may be a general material capable of generating smoke and / or aerosol commonly used in the corresponding technical field. Specifically, the medium may include tobacco raw materials such as tobacco leaf pieces and tobacco stems, and materials processed therefrom. As a more specific example, the medium may include crushed tobacco leaves, expanded stems, tobacco cut filler (example: leaf tobacco cut filler, reconstituted tobacco leaf cut filler), tobacco sheets (example: reconstituted tobacco leaf) and the like.

[0092] In some examples, the medium may further include one or more types of additives among a wetting agent and a flavoring agent. For example, the wetting agent may maintain an appropriate level of moisture in the medium to soften the unique taste and enrich the vapor production. Specifically, the wetting agent may include at least one of glycerin, propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and oleyl alcohol. For example, the flavoring agent may be added to enhance flavor. Specifically, the flavoring agent may include licorice, sucrose, fructose syrup, isosweet, cocoa, lavender, cinnamon, cardamom, celery, fenugreek, cascarilla, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon oil, orange oil, mint oil, caraway, cognac, jasmine, chamomile, menthol, ylang ylang, salvia, spearmint, ginger, coriander, clove extract (or clove material), coffee or the like.

[0093] FIG. 2 illustrates a smoking article according to another embodiment of the present disclosure.

[0094] Referring to FIG. 2, in the smoking article 100 according to another embodiment of the present disclosure, the filter portion 10 may include a first portion 10a and a second portion 10b that is different from the first portion 10a. Specifically, the second portion 10b may be closer to the medium portion 20 than the first portion 10a.

[0095] In some embodiments of the present disclosure, the second portion 10b may include the filter for a smoking article of some embodiments. According to some embodiments of the present disclosure, as the second portion 10b includes the filter for a smoking article, the vapor phase components are effectively removed before outside air that is introduced through the perforation is introduced into the smoking article, and as a result, a smoking article having low taste and aroma intensity and irritation may be obtained.

[0096] In some embodiments of the present disclosure, the first portion 10a may not include the activated carbon described above. According to some embodiments of the present disclosure, as the first portion 10a does not include the activated carbon, the vapor phase components may be effectively removed before outside air that is introduced through the perforation is introduced into the smoking article.

[0097] In some embodiments of the present disclosure, the content of the carbonyl vapor phase components produced under the smoking condition of ISO 21160 may be 30 μg / cig or less, 28 μg / cig or less, 20 μg / cig or less, 10 μg / cig or less, 5 μg / cig or less, 1.8 μg / cig or less, 1.7 μg / cig or less, or 1.66 μg / cig or less. For example, the carbonyl vapor phase component may include formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, crotonaldehyde, methyl ethyl ketone and butyraldehyde, or may be formed therewith. Specifically, when the filter portion has a length of 28 mm or more, 29 mm or more or 30 mm or more and a circumference of 23 mm or less, 22 mm or less, 21 mm or less or 20 mm or less, the effect of reducing the vapor phase components including carbonyls may be further improved.

[0098] In some embodiments of the present disclosure, the content of the volatile organic compounds produced under the smoking condition of ISO 21330 may be 15 μg / cig or less, 14 μg / cig or less, 13 μg / cig or less, 12 μg / cig or less, 11 μg / cig or less, 10 μg / cig or less, 9 μg / cig or less, 8 μg / cig or less, 7 μg / cig or less, 6 μg / cig or less, 5 μg / cig or less, or 4.8 μg / cig or less. For example, the volatile organic compound may include 1,3-butadiene, isoprene, acrylonitrile, benzene and toluene, or may be formed therewith. Specifically, when the filter portion has a length of 28 mm or more, 29 mm or more or 30 mm or more and a circumference of 23 mm or less, 22 mm or less, 21 mm or less or 20 mm or less, the effect of reducing the vapor phase components of the volatile organic compounds may be further improved.MODE FOR INVENTION

[0099] Hereinafter, examples of the present disclosure will be described in detail so that those skilled in the art to which the present disclosure pertains may readily carry out the present disclosure. However, these are for illustrative purposes only, and the scope of a right of the present disclosure is not limited by the following description.

[0100] In the present specification, the term such as “about” or “substantially” means a reasonable amount of deviation of a term modified so as not to significantly change a final result. Such a term may be interpreted to include a deviation of at least ±5% or at least ±10% within a limit that the deviation does not invalidate the meaning of the word by the modification.Preparation Example 1: Preparation of Activated CarbonComparative Example 1: Preparation of General Activated CarbonCarbonizing Coconut Shell:

[0101] A coconut shell was heated for about 4 days at about 500° C., and then cooled for about 12 hours at room temperature to prepare a carbonized coconut shell. Through this, hydrocarbons and volatiles included in the coconut shell were removed.Primarily Activating Carbonized Coconut Shell:

[0102] The carbonized coconut shell was introduced to a reactor, and then primarily activated for about 2 hours at about 830° C. using water (liquid) that is an activating agent to prepare a porous structure. Herein, the content of the water was adjusted to about 100 parts by weight with respect to about 100 parts by weight of the carbonized coconut shell.Pulverizing:

[0103] The porous structure was pulverized using a pulverizer to prepare general activated carbon having a size of about 30 mesh×80 mesh.Comparative Example 2: Preparation of Super Activated Carbon

[0104] The general activated carbon of Comparative Example 1 was introduced to a reactor, and then secondarily activated for about 4 hours at about 870° C. using water (liquid) to prepare super activated carbon. Herein, the content of the water was adjusted to about 95 parts by weight with respect to 100 parts by weight of the general activated carbon.Example 1: Preparation of Ultra Activated Carbon

[0105] The general activated carbon of Comparative Example 1 was introduced to a reactor, and then secondarily activated for about 6 hours at about 950° C. using water (liquid) to prepare ultra activated carbon. Herein, the content of the water was adjusted to about 110 parts by weight with respect to 100 parts by weight of the general activated carbon.Experimental Example 1: Measurement of Activated Carbon Properties

[0106] Properties of the activated carbon prepared using the method according to each of Comparative Examples 1 and 2, and Example 1 were measured using the following methods.Method for Measuring BET Specific Surface Area and Volume of Each Pore:

[0107] The specific surface area, the ratio of each pore, and the volume per unit mass of each pore of the activated carbon sample (0.2 g) prepared using the method according to each of Comparative Examples 1 and 2, and Example 1 were measured by a BET (Brunauer, Emmett, Teller) analysis using a BET specific surface area measurement device (ASAP-2020 device manufactured by Micromeritics Instrument Corporation, USA). Specifically, the BET specific surface area (SBET) of the activated carbon was obtained by nitrogen gas adsorption at 77K. The volume of each pore (pore volume) was measured using nitrogen adsorption and mercury porosimetry technique. The ratio of each pore means a ratio of the volume of each pore with respect to the total pore volume, and was calculated by measuring the total pore volume and the volume of each pore.Iodine Adsorption Capacity:

[0108] The activated carbon prepared using the method according to each of Comparative Examples 1 and 2, and Example 1 was measured in accordance with KS M 1802-a.TABLE 1ComparativeComparativeClassificationExample 1Example 2Example 1NameGeneralSuperUltraActivatedActivatedActivatedCarbonCarbonCarbonActivating AgentWaterWaterWater(Liquid)(Liquid)(Liquid)Activating Agent—95 Parts110 PartsContent (Secondaryby Weightby WeightActivation Step)Primary Activation830° C. / 830° C. / 830° C. / Temperature / Time2 hours2 hours2 hoursSecondary Activation—870° C. / 950° C. / Temperature / Time4 hours6 hoursMicropore Ratio96vol%90vol %75.9vol %(vol %)Mesopore Ratio3vol %8vol %20.5vol%(vol %)Macropore Ratio1vol %2vol %3.6vol %(vol %)BET Specific Surface1,113m2 / g1,765m2 / g2,207m2 / gArea (m2 / g)Total Pore Volume0.451.151.28(cm3 / g)Micropore Volume0.400.850.97(cm3 / g)Mesopore Volume0.030.200.26(cm3 / g)Macropore Volume0.020.100.05(cm3 / g)Iodine Adsorption1,0521,8311,853Capacity (mg / g)Preparation Example 2: Manufacture of Smoking ArticlePreparation Example 2-1: Regular Smoking Article

[0109] The smoking article is formed with a filter portion and a medium portion (cut filler weight: about 590 mg). The filter portion (length: 27 mm) is divided into a first portion and a second portion along the longitudinal direction of the smoking article. Herein, the first portion is adjacent to a mouth end (ME) compared to the second portion, and has a length of about 15 mm. The second portion is adjacent to the medium portion compared to the first portion, and has a length of about 12 mm. Herein, the unencapsulated pressure drop (UPD) of the smoking article was controlled to about 61 mm H2O, and the ventilation rate (VR) of the smoking article was controlled to about 81%.

[0110] As shown in the following Table 2, a filter portion was prepared by adjusting the content of the activated carbon according to each of Comparative Examples 1 and 2, and Example 1 to 24 mg / 12 mm with respect to the overall length of the second portion.TABLE 2Specification and Use of Raw MaterialsSuctionFilter LengthResistanceTowPlasticizerActivated(mm)(mmH2O)(De)(TEC, %)CarbonFirstSecondFirstSecondFinishedFirstSecondFirstSecond(mg / 12 mm)ClassificationPortionPortionPortionPortionProductPortionPortionPortionPortionTypeComparative151253.7561.254603.0 / 2.5 / 98GeneralExample 135K45K(General)Comparative151253.7561.254603.0 / 2.5 / 98SuperExample 235K45K(Super)Example 1151253.7561.254603.0 / 2.5 / 98Ultra(Ultra)35K45KSpecification and Use of Raw MaterialsActivatedPropertiesCarbonSuctionActivated(mg / 12 mm)ResistanceCircumferenceWeightCarbonSecond(mmH2O)(mm)(mg)ContentClassificationPortionAverageDeviationAverageAveragemg / TipComparative24456.89.224.20853.725.2Example 1(General)Comparative24462.48.424.20850.825.4Example 2(Super)Example 124465.411.724.22843.325.3(Ultra)Preparation Example 2-2: Ultra-Slim Smoking Article

[0111] The smoking article is formed with a filter portion and a medium portion (cut filler weight: about 350 mg). The filter portion (length: 30 mm) is divided into a first portion and a second portion along the longitudinal direction of the smoking article. Herein, the first portion is adjacent to a mouth end (ME) compared to the second portion, and has a length of about 15 mm. The second portion is adjacent to the medium portion compared to the first portion, and has a length of about 15 mm. Herein, the unencapsulated pressure drop (UPD) of the smoking article was controlled to about 94 mm H2O, and the ventilation rate (VR) of the smoking article was controlled to about 84%.

[0112] As shown in the following Table 3, a filter portion was prepared by adjusting the content of the activated carbon according to each of Comparative Examples 1 and 2, and Example 1 to 13.5 mg / 15 mm with respect to the overall length of the second portion.TABLE 3Specification and Use of Raw MaterialsFilterSuctionCelluloseActivatedLengthResistanceAcetatePlasticizerCarbon(mm)(mmH2O)Tow (De)(TEC, %)(mg / 15FirstSecondFirstSecondFinishedFirstSecondFirstSecondmm)ClassificationPortionPortionPortionPortionProductPortionPortionPortionPortionTypeReference151566.67113.337206.0 / 5.9 / 1010BambooExample17K21K(Bamboo)Comparative151566.67113.337206.0 / 5.9 / 1010GeneralExample17K21K1(General)Comparative151566.67113.337206.0 / 5.9 / 1010SuperExample17K21K2(Super)Example151566.67113.337206.0 / 5.9 / 1010Ultra117K21K(Ultra)Specification and Use of Raw MaterialsPropertiesActivatedCarbon(mg / 15SuctionActivatedmm)ResistanceCircumferenceWeightCarbonSecond(mmH2O)(mm)(mg)ContentClassificationPortionAverageDeviationAverageAveragemg / TipReference13.5731.220.416.69525.614.5Example(Bamboo)Comparative13.5722.417.916.72529.715.2Example1(General)Comparative13.5730.115.116.70522.015.3Example2(Super)Example13.5731.015.316.71519.714.31(Ultra)Experimental Example 1: Effect of Reducing Carbonyl Vapor Phase Components

[0113] For each of the smoking articles according to Preparation Examples 2-1 and 2-2, the effect of reducing carbonyl smoke components was examined by collecting carbonyl components produced during smoking under the condition of ISO 21160 in an acetonitrile solution including a 2,4-DNPH (2,4-dinitrophenylhydrazine) derivative and then analyzing the carbonyl components using HPLC (high performance liquid chromatography), and the analysis results are shown in the following Tables 4 and 5.

[0114] Meanwhile, in the following Tables 4 and 5, Form is formaldehyde, Acet is acetaldehyde, Propion is propionaldehyde, Croton is crotonaldehyde, MEK is methyl ethyl ketone, and Butyr is butyraldehyde.TABLE 4[PreparationExample 2-1:Carbonyls [μg / cig.]Regular]FormAcetAcetoneAcroleinPropion.Croton.MEKButyr.TotalComparative0.1832.7220.8680.1720.2100.0090.1810.1594.51Example 1(General)Comparative0.1651.2510.2610.0520.0640.0020.0500.0421.89Example 2(Super)Example 10.1681.1380.1960.0390.0480.0030.0400.0311.66(Ultra)ExampleCompared to8.1858.2077.4377.1377.34—77.9480.7163.101ComparativeReductionExample 1RateCompared to—9.0624.9024.3625.13—19.4626.9811.86ComparativeExample 2TABLE 5[PreparationExample 2-2:Carbonyls [μg / cig.]Ultra-Slim]Form.Acet.AcetoneAcroleinPropion.Croton.MEKButyr.TotalReference3.94062.20720.4334.4474.3400.2534.3673.073103.1Example(Bamboo)Comparative3.82048.20714.1073.1132.6530.1002.7072.18776.9Example 1(General)Comparative3.30025.3603.5100.6800.9500.0000.4300.30034.5Example 2(Super)Example 13.02020.5002.6000.55310.8300.0000.3000.20028.0(Ultra)Example 1Compared to23.3567.0587.2887.5680.88—93.1393.4972.83ReductionReferenceRateExampleCompared to20.9457.4781.5782.2368.72—88.9290.8563.58ComparativeExample 1Compared to8.4819.1625.9318.6312.63—30.2333.3318.90ComparativeExample 2Referring to Tables 4 and 5, it was identified that the smoking article including the activated carbon of Example 1 had an excellent effect in removing carbonyl smoke components compared to Comparative Examples 1 and 2. In addition, in Table 5, it was identified that the smoking article including the activated carbon of Example 1 had an excellent effect in removing carbonyl smoke components compared to the smoking article including activated carbon prepared using bamboo as a raw material (Reference Example).Experimental Example 2: Evaluation on Removal of Volatile Organic Compounds (VOCs)

[0116] For each of the smoking articles according to Preparation Examples 2-1 and 2-2, volatile organic compound (VOC) components produced during smoking under the condition of ISO 21330 were collected in a methanol solution (20 mL) including an internal standard solution (200 μl) and then analyzed using a gas chromatography-mass spectrometry (Agilent Technologies, 6890N Network GC system), and the analysis results are shown in the following Tables 6 and 7.TABLE 6[PreparationVOCs [μg / cig.]Example 2-1:1,3-Regular]ButadieneIsopreneAcrylonitrileBenzeneTolueneTotalComparative5.4941.35<LOQ3.162.2652.3Example 1(General)Comparative1.7812.64<LOQ0.880.9116.2Example 2(Super)Example 11.379.16<LOQ0.660.8312.0(Ultra)Example 1Compared to74.9877.84—79.1163.2576.99ReductionComparativeRateExample 1Compared to22.9827.49—25.138.6925.81ComparativeExample 2TABLE 7[PreparationVOCs [μg / cig.]Example2-2:1,3-Ultra-Slim]ButadieneIsopreneAcrylonitrileBenzeneTolueneTotalReference3.9723.410.222.222.3932.2Example(Bamboo)Comparative3.2518.700.171.732.0125.9Example 1(General)Comparative0.723.57<LOQ0.190.815.3Example 2(Super)Example 10.573.33<LOQ0.160.794.8(Ultra)Example 1Compared to85.5285.76—92.9867.2184.95ReductionReferenceRateExampleCompared to82.3282.17—90.9960.8981.25ComparativeExample 1Compared to19.636.50—17.202.708.08ComparativeExample 2Experimental Example 3: Sensory Evaluation on Smoking Article20 evaluation panels were selected, and smoke quantity, smoke suckability, taste and aroma intensity, irritation, and off-flavor during smoking were evaluated for the smoking article according to Preparation Example 2-1. The significance level was set at 0.05. When the significance probability of the sensory evaluation item is 0.05 or less, it means that performance on the above-mentioned evaluation item is affected depending on the type of activated carbon.TABLE 8PreparationTasteOff-ExampleRichandflavor2-1:SmokeSmokeAromaIrrita-duringRegularQuantitySuckabilityIntensitytionSmokingComparative5.104.274.805.133.47Example 1(General)Example 15.074.104.454.703.40(Ultra)Significance0.790.140.050.040.55Probability(P-value)Referring to Table 8, Example 1 showed lower taste and aroma intensity and irritation compared to Comparative Example 1 by having a BET specific surface area of 2,000 m2 / g or more, and the ratio of the micropores in the activated carbon adjusted to 70 vol % to 80 vol %.

[0119] Features described in one embodiment described above may be combined with other embodiments unless description contrary thereto is explicitly stated. In addition, preferred embodiments of the present disclosure have been described in detail hereinbefore, however, the scope of a right of the present disclosure is not limited thereto, and various modified and improved forms made by those skilled in the art using the basic concept of the present disclosure defined in the claims also fall within the scope of a right of the present disclosure.REFERENCE NUMERAL100: Smoking Article

[0121] 10: Filter Portion

[0122] 10a: First Portion

[0123] 10b: Second Portion

[0124] 20: Medium Portion

Claims

1. Activated carbon comprising a micropore having a pore diameter of less than 2 nm,wherein a ratio of the micropores is from 70 vol % to 80 vol % based on a total pore volume of the activated carbon, andthe activated carbon has a BET specific surface area of 2,000 m2 / g or more.

2. The activated carbon of claim 1, wherein the micropore has a volume of 0.8 cm3 / g to 1.1 cm3 / g.

3. The activated carbon of claim 1, further comprising a mesopore having a pore diameter of 2 nm or more and 50 nm or less,wherein a ratio of the mesopores is from 15 vol % to 25 vol % based on a total pore volume of the activated carbon.

4. The activated carbon of claim 3, wherein the mesopore has a volume of 0.2 cm3 / g to 0.4 cm3 / g.

5. The activated carbon of claim 1, further comprising a macropore having a pore diameter of more than 50 nm,wherein a ratio of the macropores is from 1 vol % to 5 vol % based on a total pore volume of the activated carbon.

6. The activated carbon of claim 5, wherein the macropore has a volume of 0.01 cm3 / g to 0.10 cm3 / g.

7. The activated carbon of claim 1, wherein the activated carbon has a BET specific surface area of 2,200 m2 / g or more.

8. The activated carbon of claim 1, wherein the activated carbon has a total pore volume of 1.0 cm3 / g or more.

9. A filter for a smoking article, the filter comprising the activated carbon of claim 1.

10. A smoking article comprising:a filter portion; anda medium portion disposed on one side of the filter portion,wherein the filter portion comprises the filter for a smoking article of claim 9.

11. The smoking article of claim 10,wherein the filter portion comprises:a first portion; anda second portion that is different from the first portion,the second portion is closer to the medium portion than the first portion, andthe second portion comprises the filter for a smoking article.

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