Cigarette filter containing lyocell tow and method for producing the same

Abstract

A cigarette filter is provided, comprising a lyocell tow made of a plurality of lyocell fibers, and a binder for binding the lyocell fibers together. The cigarette filter according to an embodiment of the present invention reduces tar and nicotine transferred to cigarette smoke by 70% to 95% by weight, respectively. The cigarette filter according to an embodiment of the present invention has a drawing resistance of 80mmWG to 200mmWG. In the cigarette filter according to an embodiment of the present invention, the lyocell tow is packed in the cigarette filter at a packing density of 0.2g / mL to 0.6g / mL. The cigarette filter according to an embodiment of the present invention solves the material problems such as hardness that the lyocell tow fundamentally has, and thus has excellent filtering functionality as a filter.

Description

[Technical Field]

[0001] The present invention relates to a cigarette filter containing lyocell tow and a method for producing the same, and more particularly to a cigarette filter containing lyocell tow and a binder and having excellent tar and nicotine reducing effects, and a method for producing the same. [Background technology]

[0002] Generally, to manufacture cigarettes, various types of leaf tobacco are first blended and processed to achieve the desired aroma and flavor. The processed leaf tobacco is then shredded to produce cut tobacco leaves, which are then wrapped in cigarette paper to produce filterless cigarettes. If necessary, a filter is then attached to the filterless cigarette.

[0003] Cigarette paper can be made from flax, wood pulp, etc., and is required to maintain the combustion properties and tobacco flavor during combustion. The cigarette filter may contain activated carbon, flavoring substances, etc., and may consist of a mono-filter or multiple filters, and is wrapped in cigarette filter wrapping paper. The tobacco shreds and the cigarette filter are connected by tipping paper, and the tipping paper may contain fine holes.

[0004] Typical cigarette filters use cellulose acetate tow, which is made by extracting cellulose from wood pulp and acetylating it. As an alternative to this, for example, tow using lyocell fiber, which is made by fiberizing cellulose itself, is being developed, unlike cellulose acetate.

[0005] When a cigarette filter is manufactured using a tow containing lyocell fiber, the hardness of the resulting cigarette filter is low, making it unsuitable for use in cigarette filters. Therefore, the hardness must be increased to a certain level. For example, methods for increasing the hardness of a filter include using a hardener or a plasticizer. The hardener method uses a binder-like substance to bond fiber strands together, thereby imparting hardness to the filter and making it stronger. The plasticizer method uses a specific substance to partially dissolve or plasticize the fibers themselves, forming junctions between the fibers, and then plasticizing the fibers. While conventional cellulose acetate uses plasticizers (such as triacetin and triethyl citrate), lyocell fiber is currently unavailable, so hardness is mainly increased by using a hardener.

[0006] As mentioned above, although the insufficient physical properties of lyocell fiber, such as its insufficient hardness, can be improved by using additional additives, unlike cellulose acetate, which has been confirmed to function as a cigarette filter, lyocell fiber is a new material and when actually applied to a cigarette filter, further investigation into the inherent filtering functionality of the cigarette filter is required.

[0007] The present inventors recognized the technical challenges in the filtering functionality of lyocell fiber-based cigarette filters and completed the present invention after continuous research into a method for more appropriately applying lyocell fiber to ensure such functionality. Summary of the Invention [Problem to be solved by the invention]

[0008] To provide a cigarette filter containing lyocell tow as an environmentally friendly material, which solves material problems such as hardness that lyocell tow fundamentally has, and which has improved filtering functionality as a filter. [Means for solving the problem]

[0009] According to a first aspect of the present invention, there is provided a cigarette filter comprising a lyocell tow consisting of a plurality of lyocell fibers and a binder that binds the lyocell fibers together.

[0010] In one embodiment of the present invention, the tar and nicotine transferred into tobacco smoke are each reduced by 70% to 95% by weight.

[0011] In one embodiment of the present invention, the cigarette filter has a drawing resistance of 80 mmWG to 200 mmWG.

[0012] In one embodiment of the present invention, the lyocell tow is packed into the cigarette filter at a packing density of 0.2 g / mL to 0.6 g / mL.

[0013] In one embodiment of the present invention, the binder is hydroxypropyl methylcellulose, hydroxypropyl cellulose, polyvinyl alcohol, ethylene vinyl acetate, polyvinyl acetate, polyvinylpyrrolidone, polyester, or a combination thereof.

[0014] In one embodiment of the present invention, the binder is contained in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of lyocell tow.

[0015] In one embodiment of the present invention, the cigarette filter further comprises a binder solvent, and the binder solvent is water, a monohydric alcohol, a polyhydric alcohol, or a combination thereof.

[0016] In one embodiment of the present invention, the monohydric alcohol is methanol, ethanol, propanol, or a combination thereof.

[0017] In one embodiment of the present invention, the polyhydric alcohol is a diol having a C1 to C4 alkylene group.

[0018] In one embodiment of the present invention, the polyhydric alcohol is contained in an amount of 0.5 to 25 parts by weight based on 100 parts by weight of lyocell tow.

[0019] According to a second aspect of the present invention, there is provided a method for manufacturing the above-mentioned cigarette filter, the method comprising the steps of: manufacturing lyocell tow using a plurality of lyocell fibers; mixing a binder and a solvent to prepare a binder solution; spraying the binder solution onto the lyocell tow and drying it; and wrapping the lyocell tow, in which the lyocell fibers are bound by the binder, in cigarette paper to manufacture a cigarette filter. [Effects of the Invention]

[0020] A cigarette filter according to one embodiment of the present invention includes lyocell tow, an environmentally friendly material, while overcoming the material problems that conventional lyocell tow has, and has excellent hardness.

[0021] The cigarette filter according to one embodiment of the present invention has a superior tar and nicotine reduction effect than conventional cellulose acetate cigarette filters.

[0022] Such a tar and nicotine reduction effect can be achieved by simply replacing the filter with a cigarette filter according to one embodiment of the present invention, without adjusting other components such as the smoking material or cigarette paper, when manufacturing a cigarette that delivers tar and nicotine below a certain level according to the smoker's preference, thereby improving the processability of producing such products. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a smoking article according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, specific examples will be described in detail with reference to the illustrative drawings. When assigning reference numerals to components in each drawing, it should be noted that the same components are assigned the same numerals as much as possible even if they appear in different drawings. Furthermore, when describing specific examples, if it is determined that a detailed description of related publicly known configurations or functions would hinder understanding of the specific examples, the detailed description will be omitted.

[0025] Furthermore, when describing components of specific examples, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are used to distinguish the component from other components, and do not limit the nature, order, or sequence of the components. When a component is described as being "coupled," "coupled," or "connected" to another component, it should be understood that the component may be directly coupled or connected to the other component, but that other components may also be "coupled," "coupled," or "connected" between each component.

[0026] Components that have a common function with components included in one specific example will be described using the same names in other specific examples. Unless otherwise specified, the description of one specific example may also be applied to other examples, and detailed descriptions will be omitted to the extent that they overlap.

[0027] As used herein, the term "smoking article" may refer to an article capable of generating aerosol, such as tobacco (cigarette), cigar, etc. Smoking articles may include an aerosol-generating substance or an aerosol-forming substrate. Smoking articles may also include solid substances based on tobacco raw materials, such as flat tobacco, shredded tobacco, or reconstituted tobacco. Smoking substances may also include volatile compounds. The smoking article may include several segments each with a specific functionality, and such segments are represented by "... segments." As used herein, smoking articles may refer not only to combustible cigarettes, but also to heated cigarettes used with an aerosol-generating device (not shown), such as electronic cigarette devices.

[0028] In this specification, the terms "upstream" and "downstream" are used to indicate the relative positions of segments constituting a smoking article with respect to the direction in which a user draws air using the smoking article. A smoking article includes an upstream end (i.e., the portion from which air enters) and an opposing downstream end (i.e., the portion from which air exits). When using a smoking article, a user can bite the downstream end of the smoking article. The downstream end is located downstream of the upstream end, and the term "end" may also be described as "terminal end."

[0029] The present invention relates to a cigarette filter applicable to smoking articles. According to one embodiment of the present invention, the cigarette filter includes a lyocell tow consisting of a plurality of lyocell fibers and a binder binding the lyocell fibers together. The lyocell fiber is an environmentally friendly fiber made from cellulose extracted from wood pulp. The lyocell tow refers to a bundle formed by cross-linking adjacent lyocell fibers. According to one embodiment of the present invention, the lyocell fiber may have a fineness of 1.0 denier to 12.0 denier. According to another embodiment of the present invention, the lyocell fiber bundle constituting the lyocell tow may have a fineness of 15,000 denier to 45,000 denier. A binder suitable for the lyocell fiber is mixed with a solvent to prepare a binder solution, which is then sprayed onto the lyocell tow and dried, allowing the lyocell tow to form a structure having a certain level of hardness.

[0030] A cigarette filter according to one embodiment of the present invention is excellent in reducing the amount of tar and nicotine transferred to cigarette smoke. Cellulose acetate has long been used as a cigarette filter material in the art, and the performance of cigarette filters using cellulose acetate can serve as a standard for evaluating the performance of cigarette filters in the art. A cigarette filter according to one embodiment of the present invention is superior in reducing tar and nicotine compared to cigarette filters using cellulose acetate when manufactured with the same drawing resistance. Specifically, the tar and nicotine components in the smoke passing through the cigarette filter are less than 90% by weight based on the content of the cellulose acetate cigarette filter. Because lyocell fiber materials are not necessarily superior in reducing tar and nicotine components compared to cellulose acetate materials due to their material characteristics, a cigarette filter according to one embodiment of the present invention is technically significant in the art.

[0031] A cigarette filter according to one embodiment of the present invention reduces the tar and nicotine transferred to tobacco smoke by 70% to 95% by weight, respectively. The reduction rate is a value obtained by comparing the weights of tar and nicotine in the tobacco smoke before and after passing through the cigarette filter. Specifically, the tar and nicotine reduction rate may be 70% by weight or more, 72% by weight or more, 74% by weight or more, 76% by weight or more, 78% by weight or more, 80% by weight or more, 82% by weight or more, 84% by weight or more, or 86% by weight or more, and may be 95% by weight or less, 94% by weight or less, 93% by weight or less, 92% by weight or less, 91% by weight or less, or 90% by weight or less. When the tar and nicotine in tobacco smoke are reduced within the above ranges, the composition may be at a level suitable for smokers.

[0032] A cigarette filter according to one embodiment of the present invention has a resistance to draw of 80 mmWG to 200 mmWG. The resistance to draw refers to the static pressure difference between two ends of a sample when traversed by an airflow under normal conditions where the volumetric flow rate is 17.5 mm per second at the discharge end. The resistance to draw can be measured using the method specified in ISO Standard 6565:2002. Specifically, the resistance to draw is 80 mmWG or more, 85 mmWG or more, 90 mmWG or more, 95 mmWG or more, or 100 mmWG or more, and 200 mmWG or less, 190 mmWG or less, 180 mmWG or less, 170 mmWG or less, 160 mmWG or less, or 150 mmWG or less, and may be 80 mmWG to 200 mmWG, 90 mmWG to 180 mmWG, or 100 mmWG to 150 mmWG. The functionality of cigarette filters containing lyocell tow within the above ranges in terms of tar and nicotine reduction can be further improved.

[0033] In one embodiment of the present invention, the lyocell tow is packed into the cigarette filter at a packing density of 0.2 g / mL to 0.6 g / mL. While increasing the packing density of the lyocell tow can improve the filter's hardness and filtration performance, it must be adjusted to an appropriate level to block the airflow path within the cigarette. Specifically, the packing density may be 0.2 g / mL or more, 0.22 g / mL or more, 0.24 g / mL or more, 0.26 g / mL or more, 0.28 g / mL or more, 0.3 g / mL or more, 0.6 g / mL or more, 0.58 g / mL or more, 0.56 g / mL or more, 0.54 g / mL or more, 0.52 g / mL or more, or 0.2 g / mL to 0.6 g / mL, 0.24 g / mL to 0.56 g / mL, or 0.3 g / mL to 0.5 g / mL. The functionality of cigarette filters containing lyocell tow within the above ranges in terms of tar and nicotine reduction can be further improved.

[0034] The above-mentioned packing density may be determined by taking into consideration not only the tar and nicotine reduction effect of the cigarette filter but also the drawing resistance. However, such a packing density may result in a cigarette filter with low hardness, requiring the use of a separate hardness enhancer. A binder may be used as a hardness enhancer, and the binder binds the lyocell fibers together to impart a certain level of hardness to the lyocell tow. The binder is a material suitable for application to lyocell fibers, and any commonly known material in the art may be used. According to one embodiment of the present invention, the binder may be hydroxyl propyl methyl cellulose (HPMC), hydroxypropyl cellulose (HPC), polyvinyl alcohol (PVA), ethylene vinyl acetate (EVA), polyvinyl acetate (PVAc), polyvinyl pyrrolidone (PVP), polyester, or a combination thereof. Specifically, the binder may be hydroxypropyl methyl cellulose, polyester, or a combination thereof.

[0035] The polyester is a synthetic resin made by reacting a polyhydric organic acid with a polyhydric alcohol, and has suitable resistance to water and various chemicals. According to one embodiment of the present invention, the polyester is a copolymer of an aromatic monomer and an aliphatic monomer. The aromatic monomer adds structural stability to the polyester, and the aliphatic monomer adds structural flexibility to the polyester. The polyester containing the aromatic monomer and the aliphatic monomer can easily bond with other components, such as lyocell fibers, and thus can function as a binder. The aromatic monomer may be a polyhydric organic acid or a polyhydric alcohol, and similarly, the aliphatic monomer may be a polyhydric organic acid or a polyhydric alcohol.

[0036] According to one embodiment of the present invention, the aromatic monomer is a dicarboxylic acid having a C5 to C12 arylene group or a heteroarylene group. Exemplarily, the dicarboxylic acid having a C5 to C12 arylene group or a heteroarylene group may be phthalic acid, terephthalic acid, or isophthalic acid. According to one embodiment of the present invention, the aliphatic monomer is a diol having a C1 to C6 alkylene group, a dicarboxylic acid having a C2 to C12 alkylene group, or a combination thereof. Exemplarily, the diol having a C1 to C6 alkylene group is ethylene glycol, and the dicarboxylic acid having a C2 to C12 alkylene group is sebacic acid. In the case of polyesters, because carboxylic acid groups and hydroxyl groups can be formed by a condensation reaction in a ratio of 1:1, the carboxylic acid group-containing monomer can be the above-mentioned dicarboxylic acid having a C5 to C12 arylene or heteroarylene group, dicarboxylic acid having a C2 to C12 alkylene group, or a combination thereof, and the hydroxyl group-containing monomer can be a diol having a C1 to C6 alkylene group. The arylene group, heteroarylene group, or alkylene group can be substituted or unsubstituted. When substituted, the main chain of the arylene group, heteroarylene group, or alkylene group can be substituted with a substituent commonly known in the art, such as a C1 to C4 alkyl group, a C1 to C4 alkoxy group, or a halogen group.

[0037] The binder can be applied to the lyocell tow in the form of a binder solution together with a solvent. After application, the binder does not flow out even when the lyocell tow dries or is left for a long time, but remains between the lyocell fibers, thereby improving the hardness of the lyocell tow. According to one embodiment of the present invention, the binder is contained in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the lyocell tow. Specifically, the content of the binder is 0.1 to 5 parts by weight, 0.2 to 0.3 parts by weight, or 0.4 to 5 parts by weight, 4 to 3.5 parts by weight, 3 to 2.5 parts by weight, or 0.1 to 5 parts by weight, 0.2 to 4 parts by weight, or 0.3 to 3 parts by weight. When applied within the above range, the binder can increase the hardness of the lyocell tow to an appropriate level without reducing its basic filtering function.

[0038] The solvent contained in the cigarette filter is basically included in the binder solution to disperse the binder. After the binder solution is sprayed onto the lyocell tow, some of the solvent is removed by drying or leaving it for a long time. Water is basically used as the solvent for the binder solution. A large amount of water can be used relative to the binder to dissolve the binder, but most of the water is removed by drying. Since the lyocell fiber is known to be a hydrophilic material, unlike hydrophobic cellulose acetate, moisture can have a negative effect on hardness. To compensate for this, the binder solution can contain an alcohol component to be used together with water or to replace water.

[0039] According to one embodiment of the present invention, the solvent includes a monohydric alcohol, such as methanol, ethanol, propanol, or a combination thereof. The monohydric alcohol is more volatile than water and may disappear in large amounts after drying. However, when stored at room temperature without a drying process, a certain level or more of the monohydric alcohol can be detected in the final cigarette filter. The monohydric alcohol can replace water as a solvent in the binder solution, thereby improving the hardness of the cigarette filter. Furthermore, the monohydric alcohol has bactericidal properties, which can provide additional functionality when applied to lyocell tow. According to one embodiment of the present invention, the monohydric alcohol is included in an amount of 1 to 500 parts by weight based on 10,000 parts by weight of lyocell tow. Because the monohydric alcohol is more volatile than polyhydric alcohols or water, the content of the monohydric alcohol varies widely. However, the lower limit of the range of the content is considered more significant than the upper limit, since when the drying process is reduced and the filter is stored at room temperature, a certain level or more of the monohydric alcohol can be detected compared to when the monohydric alcohol is not added.

[0040] According to one embodiment of the present invention, the solvent includes a polyhydric alcohol. Here, polyhydric alcohol refers to a compound containing two or more hydroxy groups. The polyhydric alcohol acts as a release agent when lyocell tow is processed using a mechanical roll or the like to apply it to a cigarette filter. Specifically, when lyocell tow is processed using a mechanical roll or the like without a release agent, the lyocell tow can become caught in the mechanical roll or the like due to the adhesive strength of the binder. However, lyocell tow containing a polyhydric alcohol reduces this phenomenon and improves processability. Furthermore, when applied to lyocell tow, the polyhydric alcohol, together with the binder, lies between the lyocell fibers, helping to improve the hardness of the lyocell tow in a short period of time, even without long drying times at high temperatures. Therefore, using a solvent containing a polyhydric alcohol significantly shortens the drying time, improving processability in cigarette filter manufacturing.

[0041] According to one embodiment of the present invention, the polyhydric alcohol is a diol having a C1-C4 alkylene group. The diol refers to a compound having two hydroxy groups and is also called a glycol. The two hydroxy groups may be connected by a C1-C4 alkylene group, and the number of carbon atoms in the alkylene group refers to the number of carbon atoms directly connected between the two hydroxy groups. The alkylene group may be substituted or unsubstituted. If substituted, the main chain of the alkylene group may be substituted with a substituent generally known in the art, such as a C1-C3 alkyl group, a C1-C3 alkoxy group, or a halogen group. According to one embodiment of the present invention, the polyhydric alcohol may be propylene glycol. Propylene glycol may be a more preferable compound having the above-mentioned functionality as a polyhydric alcohol having an appropriate chain length.

[0042] The polyhydric alcohol can be applied to lyocell tow in the form of a binder solution together with a binder and other solvents. The polyhydric alcohol remains unchanged in the lyocell tow or the cigarette filter to which it is applied before and after drying, imparting the aforementioned functionality, such as improved hardness and processability. According to one embodiment of the present invention, the polyhydric alcohol is contained in an amount of 0.5 to 25 parts by weight based on 100 parts by weight of lyocell tow. Specifically, the content of the polyhydric alcohol is 0.5 parts by weight or more, 0.6 parts by weight or more, 0.7 parts by weight or more, 0.8 parts by weight or more, 0.9 parts by weight or more, or 1 part by weight or more, and may be 25 parts by weight or less, 20 parts by weight or less, 15 parts by weight or less, 10 parts by weight or less, or 5 parts by weight or less, or may be 0.5 to 10 parts by weight, 0.7 to 7 parts by weight, or 1 to 5 parts by weight. When the polyhydric alcohol is applied within the above range, it can impart additional functionality to the cigarette filter without impairing the basic filter function of the lyocell tow.

[0043] A cigarette filter containing lyocell tow according to one embodiment of the present invention has excellent hardness due to the binding of a binder. According to one embodiment of the present invention, the cigarette filter has a hardness of 85% or more. Specifically, the hardness of the cigarette filter may be 85% or more, 86% or more, 87% or more, 88% or more, or 89% or more. The hardness of the cigarette filter is a numerical value that represents the degree to which the diameter of the cigarette filter is maintained when the cigarette filter is pressed with a certain level of force in the vertical direction, and can be calculated using the following equation 1:

[0044] [Formula 1] Filter hardness (%) = [Da] / D x 100

[0045] Here, D is the filter diameter (mm), and a is the distance (mm) that a 300 g weight moves down (pressing the filter). The measurements required to calculate the hardness of the cigarette filter can be obtained using a device commonly used in the art, such as Filtrona's DHT 200. TM can be used. The force applied when measuring hardness takes into consideration the force applied when a smoker actually grips a cigarette. The hardness value of 85% or more obtained by the cigarette filter according to one embodiment of the present invention is technically significant in that it ensures a hardness level that can replace conventional cigarette filters made of cellulose acetate by using lyocell tow, an environmentally friendly material. Furthermore, the cigarette filter according to one embodiment of the present invention can achieve an excellent hardness value of 85% or more as described above even after the time required for the binder to set at room temperature has elapsed, without undergoing a drying process at high temperatures, thereby significantly improving processability in product manufacturing.

[0046] The above-mentioned cigarette filter can be manufactured by the following manufacturing method. The manufacturing method includes the steps of: preparing lyocell tow using lyocell fiber; preparing a binder solution by mixing a binder and a solvent; spraying the binder solution onto the lyocell tow and drying it; and wrapping the lyocell tow, to which the lyocell fiber is bound by the binder, in cigarette paper to manufacture a cigarette filter. Since the manufacturing method basically relates to a method for manufacturing the above-mentioned cigarette filter, a description of the specific aspects of the above content will be omitted, and the following will describe the characteristics of the manufacturing method in more detail.

[0047] First, lyocell tow is produced using a plurality of lyocell fibers. The produced lyocell tow has a bundle shape formed by cross-linking adjacent lyocell fibers. In this process, a step of expanding the tow through blooming is further carried out. Expanding the tow through the blooming step allows the binder solution sprayed thereafter to easily penetrate between the lyocell fibers that make up the lyocell tow.

[0048] Next, a binder solution is prepared by mixing a binder and a solvent. The binder solution is a substance sprayed onto the lyocell tow to improve its functionality, such as its hardness. Since some components of the binder solution may be lost during the drying process after spraying, the composition of the binder solution may differ from the composition of the components constituting the cigarette filter. The binder may be embodied as described above, and since the components do not particularly disappear even after drying, the amount supplied to the lyocell tow through spraying remains almost unchanged in the final cigarette filter. The solvent contains water, and some of the water is lost during the drying process. When the binder solution is prepared using only a binder and water, the water content is the portion of the binder solution excluding the binder content. According to one embodiment of the present invention, the binder is included in an amount of 5 to 40 parts by weight based on 100 parts by weight of the binder solution. Specifically, the content of the binder is 5 parts by weight or more, 6 parts by weight or more, 7 parts by weight or more, 8 parts by weight or more, 9 parts by weight or more, 10 parts by weight or more, and 40 parts by weight or less, 35 parts by weight or less, 30 parts by weight or less, 25 parts by weight or less, 20 parts by weight or less, or may be 5 to 40 parts by weight, 7 to 30 parts by weight, or 10 to 20 parts by weight. When a binder solution is formed within the above range, the binder can be easily sprayed and applied to the lyocell tow.

[0049] When the solvent contains a polyhydric alcohol, the solvent contains water in addition to the polyhydric alcohol. If the solvent is entirely composed of a polyhydric alcohol, the viscosity may be excessively high, making it difficult to disperse the binder. Water may be present only in an amount remaining after the proportion of the solvent, such as the polyhydric alcohol, and some of the water will disappear during the drying process. According to one embodiment of the present invention, the polyhydric alcohol is present in an amount of 5 to 50 parts by weight based on 100 parts by weight of the binder solution. Specifically, the content of the polyhydric alcohol may be 5 parts by weight or more, 6 parts by weight or more, 7 parts by weight or more, 8 parts by weight or more, 9 parts by weight or more, or 10 parts by weight or more, and may be 50 parts by weight or less, 45 parts by weight or less, 40 parts by weight or less, 35 parts by weight or less, or 30 parts by weight or less, and may be 5 to 50 parts by weight, 7 to 40 parts by weight, or 10 to 30 parts by weight. When the polyhydric alcohol is used within the above range, it can impart additional functionality to the cigarette filter without reducing the basic filter function of the lyocell tow.

[0050] The solvent may further include a monohydric alcohol. The monohydric alcohol is a component with higher volatility than water and may disappear in large amounts after drying. However, if the filter is stored at room temperature without undergoing a drying process, a certain level or more of the monohydric alcohol may remain in the final cigarette filter. The monohydric alcohol is a component that can replace water in the solvent of the binder solution, and can adjust the water content of the final cigarette filter. According to one embodiment of the present invention, the monohydric alcohol is methanol, ethanol, propanol, or a combination thereof. Specifically, the monohydric alcohol may be ethanol.

[0051] The monohydric alcohol may be included in a certain amount to replace water. According to one embodiment of the present invention, the monohydric alcohol is included in an amount of 5 to 60 parts by weight based on 100 parts by weight of the binder solution. Specifically, the content of the monohydric alcohol is 5 parts by weight or more, 6 parts by weight or more, 7 parts by weight or more, 8 parts by weight or more, 9 parts by weight or more, or 10 parts by weight or more, and is 60 parts by weight or less, 55 parts by weight or less, 50 parts by weight or less, 45 parts by weight or less, 40 parts by weight or less, 35 parts by weight or less, or 30 parts by weight or less, and may be 5 to 60 parts by weight, 7 to 45 parts by weight, or 10 to 30 parts by weight. When the monohydric alcohol is used within the above range, it can effectively reduce the water content in the cigarette filter by a significant amount.

[0052] The binder solution prepared as described above is sprayed onto the lyocell tow. The binder solution can be sprayed onto the lyocell tow to an extent that overcomes the inherent hardness and other problems inherent to the lyocell tow without impairing the lyocell tow's basic filtering function. According to one embodiment of the present invention, 5 to 30 parts by weight of the binder solution is sprayed onto the lyocell tow, based on 100 parts by weight of the lyocell tow. Specifically, the amount of the binder solution sprayed is 5 parts by weight or more, 6 parts by weight or more, 7 parts by weight or more, 8 parts by weight or more, 9 parts by weight or more, or 10 parts by weight or more, and is 30 parts by weight or less, 28 parts by weight or less, 26 parts by weight or less, 24 parts by weight or less, 22 parts by weight or less, or 20 parts by weight or less, and may be 5 to 30 parts by weight, 7 to 24 parts by weight, or 10 to 20 parts by weight. When the binder solution is sprayed within the above range, it can improve the functionality of the lyocell tow, such as its hardness. The method of spraying the binder solution may be a method commonly used in the art and is not particularly limited. For example, the binder solution may be sprayed using a nozzle spray, a brush spray, or an electric spray.

[0053] After spraying the binder solution onto the lyocell tow, the tow is dried to allow the binder to set and the lyocell fibers to bond to each other. This drying process can be carried out at room temperature or at an elevated temperature using a method commonly used in the art. A cigarette filter is manufactured by wrapping the lyocell tow, with the lyocell fibers bonded to it by the binder, in cigarette paper. If necessary, the lyocell tow can be processed to a size suitable for use in a cigarette filter using a mechanical roll or cutter. The degree of filling of the lyocell tow into the cigarette filter can be adjusted according to the above-mentioned details.

[0054] The above-described cigarette filter can be applied to a smoking article. Fig. 1 shows a schematic configuration of a smoking article according to one embodiment of the present invention. The smoking article 100 includes a smoking material portion 10 and a filter portion 20, and the above-described cigarette filter is applied to the filter portion 20 of the smoking article 100. In the smoking article 100, the smoking material portion 10 is located upstream of the filter portion 20.

[0055] The smoking material portion 10 can be filled with smoking material such as raw tobacco, flakes, or a mixture of leaf tobacco and flakes. Processed smoking material can be filled into the smoking material portion 10 in sheet or shredded form. The smoking material portion 10 can have an elongated rod shape, and its length, circumference, and diameter can be adjusted to sizes commonly used in the art, taking into account, but not limited to, the amount of smoking material to be filled and the user's preferences. The smoking material portion 10 can contain at least one aerosol-generating substance selected from the group consisting of glycerin, propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and oleyl alcohol. The smoking material portion 10 can also contain other additives, such as flavorants, humectants, and / or acetate compounds. The aerosol-generating substance and additives can be incorporated into the smoking material.

[0056] The filter unit 20 is disposed downstream of the smoking material unit 10 and serves as a filter through which aerosol generated in the smoking material unit 10 passes just before the user inhales. The filter unit 20 can be manufactured using various materials and shapes. The filter unit 20 according to one embodiment of the present invention basically includes the above-mentioned cigarette filter containing lyocell tow, in which a plurality of lyocell fibers are bound together by a binder. The cigarette filter containing lyocell tow can replace all or part of the filter unit 20 of a conventional smoking article, and when replacing only part of it, conventional filter materials can be used together. Conventional filter materials include, for example, cellulose acetate filters and hollow tube filters.

[0057] 1 shows that the filter unit 20 is a mono-filter consisting of a single filter, but is not limited to this. For example, the filter unit 20 may be a dual filter or triple filter equipped with two acetate filters to increase filtering efficiency. Furthermore, although not shown, the filter unit 20 may contain a crushable capsule (not shown) having a structure in which a flavor-containing oral liquid is encapsulated in a coating.

[0058] The exterior of the smoking material portion 10 and the filter portion 20 may be wrapped in a wrapper 30a or 30b.

[0059] The smoking material portion 10 can be wrapped in a smoking material wrapper 30a. A portion of the tobacco smoke generated during the combustion of a typical smoking material portion 10 is released into the atmosphere through the smoking material wrapper 30a before passing through the cigarette filter, resulting in sidestream smoke that is unpleasant for secondhand smokers. Various attempts have been made to reduce sidestream smoke, such as incorporating fillers such as magnesium oxide, titanium oxide, cerium oxide, aluminum oxide, calcium carbonate, and zirconium carbonate into cigarette paper. However, simply applying these fillers to reduce sidestream smoke can result in a decrease in smoking experience, burn-off, and ash caking, making it difficult to solve these problems through an appropriate combination of fillers. The smoking material wrapper 30a according to one embodiment of the present invention uses a filler containing a mixture of magnesium oxide (MgO and / or Mg(OH)2) and calcium carbonate (CaCO3) to reduce sidestream smoke while preventing the decrease in smoking experience, burn-off, and ash caking.

[0060] The filter part 20 may be wrapped in a filter part wrapper 30b. The filter part wrapper 30b may be made of oil-resistant wrapping paper, and may further include aluminum foil on the inner surface of the filter part wrapper 30b.

[0061] The smoking material section 10 wrapped in the smoking material section wrapper 30a and the filter section 20 wrapped in the filter section wrapper 30b can be bound and wrapped with tipping paper 40. As shown in FIG. 1, the tipping paper 40 may be wrapped around at least a portion (e.g., a downstream region) of the smoking material section wrapper 30a and the outer shell of the filter section wrapper 30b. In other words, at least a portion of the smoking material section 10 and the filter section 20 may be further wrapped and physically bound with the tipping paper 40. According to one embodiment of the present invention, the tipping paper 40 may be made of, but is not limited to, non-porous wrapping paper that has not been treated for oil resistance. The tipping paper 40 may also contain, but is not limited to, a non-flammable material to prevent the filter section 20 from burning.

[0062] A smoking article according to one embodiment of the present invention has a tar transfer rate of less than 3.7 mg and a nicotine transfer rate of less than 0.36 mg. These are lower tar and nicotine transfer rates than those using a cellulose acetate filter. Specifically, the tar transfer rate may be less than 3.7 mg, 3.6 mg or less, 3.5 mg or less, 3.4 mg or less, 3.3 mg or less, or 3.2 mg or less, and the nicotine transfer rate may be less than 0.36 mg, 0.35 mg or less, 0.34 mg or less, 0.33 mg or less, 0.32 mg or less, 0.31 mg or less, 0.3 mg or less, or 0.29 mg or less. The smoking article according to one embodiment of the present invention is significant because it has a superior tar and nicotine reduction effect compared to a cellulose acetate filter.

[0063] The configuration and effects of the present invention will be described in more detail below with reference to examples and comparative examples. However, these examples are intended to more specifically explain the present invention, and the scope of the present invention is not limited to these examples.

[0064] Example Example 1 Lyocell tow with a tow fiber bundle of approximately 35,000 denier was used, using Lyocell fibers with a fiber diameter of approximately 3.0 denier. A binder solution, which is a mixture of a binder and a solvent, was also prepared. Specifically, the binder solution contained 15% by weight of polyester (a copolymer of phthalic acid, sebacic acid, and ethylene glycol), a weight-average molecular weight (M w ) = 3,000~6,000) was added to 85 wt% of a solvent (a mixed solvent of 30 wt% propylene glycol and 55 wt% water). The prepared binder solution was sprayed onto lyocell tow using a nozzle spray. 15 wt% of the binder solution, based on the weight of the lyocell tow, was sprayed onto the tow and stored at room temperature for 6 hours to prepare a lyocell tow containing the binder. The prepared lyocell tow was wrapped in cigarette paper to prepare a cigarette filter with an axial length of approximately 27 mm and a circumference of approximately 23.7 mm. The lyocell tow in the cigarette filter had a packing density of approximately 0.4 g / mL, which means that the lyocell tow did not contain a binder. The draw resistance of the cigarette filter was measured to be approximately 112.5 mmWG using a draw resistance measuring device (manufacturer: Cadian, product name: BWSPtHT-1).

[0065] Comparative Example 1 Cellulose acetate tow of the same denier was used instead of lyocell tow. Triethyl citrate (TEC) was used as a plasticizer instead of a binder to improve hardness. The plasticizer was sprayed onto the cellulose acetate tow through a nozzle spray. 7 wt% of the plasticizer solution was sprayed onto the cellulose acetate tow to produce plasticizer-containing cellulose acetate tow. The cellulose acetate tow was wrapped in cigarette paper to produce a cigarette filter with an axial length of approximately 27 mm and a circumference of approximately 24.2 mm. The cellulose acetate tow in the cigarette filter had a packing density of approximately 0.36 g / mL, which means that the cellulose acetate tow did not contain any plasticizer. The draw resistance of the cigarette filter was measured to be approximately 112.5 mmWG using a draw resistance measuring device (manufacturer: Cadian, product name: BWSPtHT-1).

[0066] Experimental example A smoking material part was prepared using 580 mg of cigarette shreds. Each of the cigarette filters prepared in Example 1 and Comparative Example 1 was combined with a smoking material part to prepare cigarettes. Hereinafter, a cigarette composed only of a smoking material part will be referred to as "Experimental Example 1," a cigarette prepared by combining the cigarette filter prepared in Example 1 with a smoking material part will be referred to as "Experimental Example 2," and a cigarette prepared by combining the cigarette filter prepared in Comparative Example 1 with a smoking material part will be referred to as "Experimental Example 3." Each cigarette was smoked using a smoking device (manufacturer: BORGWALDT, product name: RM2OH), and the smoke was collected and analyzed for components using GC (Gas Chromatography). The component analysis results are shown in Table 1 below.

[0067] [Table 1]

[0068] According to Table 1, it was confirmed that the cigarette filter according to Example 1 (Experimental Example 2) had a superior effect of reducing tar and nicotine compared to the cigarette filter according to Comparative Example 1 (Experimental Example 3), despite the same drawing resistance. Depending on the smoker's preference, a cigarette that transfers tar and nicotine below a certain level may be required. When using the cigarette filter according to Example 1, which has an excellent effect of reducing tar and nicotine, tar and nicotine can be reduced more easily without adjusting other components such as the smoking material part or cigarette paper, thereby improving the processability of product production.

[0069] Although the embodiments have been described above by way of limited examples and drawings, those skilled in the art will appreciate that various modifications and variations may be made from the above description, for example, the techniques described may be performed in a different order than described, and / or the components of the described systems, structures, devices, circuits, etc. may be combined or combined in a different manner than described, or may be substituted or replaced by other components or equivalents, and still achieve suitable results.

Claims

1. a lyocell tow made of a plurality of lyocell fibers; a binder that binds the lyocell fibers together; the binder comprises a polyester; A cigarette filter that reduces the amount of tar and nicotine transferred into tobacco smoke by 70% to 95% by weight.

2. A cigarette filter as described in claim 1, wherein the polyester is a copolymer of an aromatic monomer and an aliphatic monomer.

3. A cigarette filter as described in claim 1, wherein the polyester is a copolymer of phthalic acid, sebacic acid, and ethylene glycol having a weight average molecular weight (Mw) of 3,000 to 6,000.

4. 2. The cigarette filter according to claim 1, wherein the cigarette filter has a resistance to draw of 80 mmWG to 200 mmWG.

5. 2. The cigarette filter according to claim 1, wherein the lyocell tow is packed into the cigarette filter at a packing density of 0.2 g / mL to 0.6 g / mL.

6. 2. The cigarette filter of claim 1, wherein the binder further comprises hydroxypropyl methylcellulose, hydroxypropyl cellulose, polyvinyl alcohol, ethylene vinyl acetate, polyvinyl acetate, polyvinylpyrrolidone, or a combination thereof.

7. The cigarette filter according to claim 1, wherein the binder is contained in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the lyocell tow.

8. The cigarette filter further comprises a binder solvent, 2. The cigarette filter according to claim 1, wherein the binder solvent is water, a monohydric alcohol, a polyhydric alcohol, or a combination thereof.

9. 9. The cigarette filter according to claim 8, wherein the monohydric alcohol is methanol, ethanol, propanol, or a combination thereof.

10. 9. The cigarette filter according to claim 8, wherein the polyhydric alcohol is a diol having a C1 to C4 alkylene group.

11. The cigarette filter according to claim 10, wherein the polyhydric alcohol is contained in an amount of 0.5 to 25 parts by weight based on 100 parts by weight of the lyocell tow.

12. The cigarette filter of claim 1, wherein the cigarette filter further comprises a binder solvent, the binder solvent comprising a polyhydric alcohol, the polyhydric alcohol being contained in an amount of 0.5 to 25 parts by weight based on 100 parts by weight of the lyocell tow, the lyocell tow being filled into the cigarette filter at a packing density of 0.2 g / mL to 0.6 g / mL, and the binder being contained in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the lyocell tow.

13. A method for producing a cigarette filter, said method comprising: Spraying a binder solution prepared by mixing a binder containing polyester and a solvent onto a lyocell tow prepared using a plurality of lyocell fibers, and drying the mixture; and wrapping the lyocell tow, in which the plurality of lyocell fibers are bound by the binder, in a cigarette paper to manufacture the cigarette filter.

14. A step of producing the lyocell tow using the plurality of lyocell fibers; The method for manufacturing a cigarette filter according to claim 13, further comprising the step of mixing the binder and the solvent to prepare the binder solution.

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