WO2023106644A1 - Cigarette filter including lyocell tow - Google Patents

Abstract

Provided is a cigarette filter that comprises a lyocell tow composed of a plurality of lyocell fibers and a binder bonding the lyocell fibers to each other and which has a hardness of 85% or greater. The cigarette filter according to an embodiment of the present invention has a hardness of 80% or greater even 5 minutes after 20 parts by weight to 25 parts by weight of water is introduced thereinto on the basis of 100 parts by weight of lyocell tow. The cigarette filter according to an embodiment of the present invention has a moisture disintegration rate of 7% or less. The cigarette filter according to an embodiment of the present invention overcomes the material problems retained by the conventional lyocell tow and has high hardness and low moisture disintegration.

Description

Cigarette filter comprising lyocell tow

The present invention relates to a cigarette filter comprising lyocell tow. Specifically, the present invention relates to a cigarette filter comprising a lyocell tow made of a plurality of lyocell fibers and a binder binding the lyocell fibers to each other, and having an excellent hardness of 85% or more.

This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0173488 dated December 7, 2021, and includes all contents disclosed in the literature of the Korean patent application as part of this specification.

In general, in order to manufacture tobacco, first, various types of leaf tobacco (leaf tobacco) are blended and processed to have a desired flavor and taste. Next, the processed tobacco leaf is cut to prepare a cut tobacco leaf, and the tobacco leaf is rolled with cigarette paper to produce a cigarette without a filter. Next, a filter is attached to the filterless cigarette as needed.

Cigarette paper can be made of hemp, wood pulp, etc., and is required to maintain combustibility and taste of tobacco when burned. The cigarette filter may include activated carbon, a flavor material, and the like, may be composed of a monofilter or a multi-filter, and is surrounded by a cigarette filter wrapping paper. The tobacco cut sheath and the tobacco filter are connected by tipping paper, and the tipping paper may include fine holes.

A general cigarette filter uses cellulose acetate tow obtained by extracting cellulose from wood pulp and acetylating it. For example, unlike cellulose acetate, development of tow using lyocell fibers in which cellulose itself is fibrous is in progress.

In cigarette filters, hardness is an important indicator related to consumer needs and workability of cigarette manufacturing. In the case of manufacturing a cigarette filter with tow, which is a bundle of fiber strands, the hardness of the cigarette filter is low and is not suitable, and it is necessary to improve the hardness to a certain level or more in order to use it as a cigarette filter. For example, a method of improving the hardness of a filter includes a method using a curing agent and a method using a plasticizer. The method of using the curing agent is a method of imparting hardness to a filter by bonding fiber strands using a material having a binder property, and making the filter hard. The method of using the plasticizer is a method of partially dissolving or plasticizing fibers themselves using a specific material to form junctions between fibers and then plasticizing them.

Existing cellulose acetate utilizes plasticizers (Triacetin, Triethyl Citrate) to partially dissolve fiber strands, and imparts hardness to cigarette filters using the principle that fiber strands are hardened. However, since lyocell fibers do not currently have plasticizers, it is essential to develop a hardness enhancer suitable for lyocell fibers.

Since the lyocell fiber is known as a hydrophilic material unlike the hydrophobic-based cellulose acetate, it is also important that the structure does not collapse from moisture supplied from smokers during smoking, even if the hardness is improved by a hardness enhancer and applied as a cigarette filter should be considered as

The present inventors recognized the technical problems of the above-mentioned lyocell fiber material and completed the present invention after continuous research on lyocell tow with excellent functionality suitable for application as a cigarette filter.

[Prior art literature]

[Patent Literature]

(Patent Document 1) Republic of Korea Patent Publication No. 10-2015-0035800

In a cigarette filter containing lyocell tow as an eco-friendly material, it is intended to provide a cigarette filter that can solve material problems such as hardness and moisture disintegration that lyocell tow basically has.

According to the first aspect of the present invention,

The present invention lyocell tow made of a plurality of lyocell fibers; and a binder binding the lyocell fibers to each other, and providing a cigarette filter having a hardness of 85% or more.

In one embodiment of the present invention, the cigarette filter has a hardness of 80% or more even after 5 minutes after injecting 20 parts by weight to 25 parts by weight of water based on 100 parts by weight of lyocell tow.

In one embodiment of the present invention, the cigarette filter has a moisture decay rate of 7% or less.

In one embodiment of the present invention, the binder includes polyester.

In one embodiment of the present invention, the polyester is a copolymer of an aromatic monomer and an aliphatic monomer.

In one embodiment of the present invention, the polyester has a viscosity of less than 5 cps at 40° C. with respect to a polyester aqueous solution having a concentration of 15% by weight.

In one embodiment of the present invention, the aromatic monomer is a dicarboxylic acid having a C5 to C12 arylene group or heteroarylene group.

In one embodiment of the present invention, the aliphatic monomer is a diol having a C1 to C4 alkylene group, a dicarboxylic acid having a C2 to C12 alkylene group, or a combination thereof.

In one embodiment of the present invention, the polyester is included in 0.1 part by weight to 5 parts by weight based on 100 parts by weight of lyocell tow.

In one embodiment of the present invention, the binder further includes hydroxy propyl methyl cellulose or poly vinyl pyrrolidone.

In one embodiment of the present invention, the weight ratio of polyester to hydroxypropyl methyl cellulose or polyvinyl pyrrolidone in the binder is 1:1 to 1:3.

The cigarette filter according to one embodiment of the present invention includes lyocell tow, which is an eco-friendly material, overcomes the material problems of existing lyocell tow, and has excellent hardness of 90% or more.

In addition, the cigarette filter has adequate durability against moisture, so that the change in hardness is minimized to 6% or less even while the smoker is smoking, and the change in hardness is reduced to 85% or more until the smoker finishes smoking and the smoking article leaves the smoker's hand. excellent hardness can be maintained.

1 is a diagram showing a schematic configuration of a smoking article according to one embodiment of the present invention.

Hereinafter, specific examples will be described in detail through exemplary drawings. In adding reference numerals to components of each drawing, it should be noted that the same components have the same numerals as much as possible even if they are displayed on different drawings. In addition, in describing a specific example, if it is determined that a detailed description of a related known configuration or function hinders understanding of the specific example, the detailed description will be omitted.

Also, terms such as first, second, A, B, (a), and (b) may be used in describing the components of the specific example. These terms are only used to distinguish the component from other components, and the nature, sequence, or order of the corresponding component is not limited by the term. When an element is described as being “connected”, “coupled” or “connected” to another element, the element may be directly connected or connected to the other element, but there may be another element between the elements. It should be understood that may be "connected", "coupled" or "connected".

Elements included in one embodiment and elements having common functions will be described using the same names in other embodiments. Unless described to the contrary, the description described in any one embodiment can also be applied to other embodiments, and specific descriptions will be omitted to the extent of overlap.

In this specification, the term "smoking article" may refer to an object capable of generating aerosol, such as cigarettes (cigarettes) and cigars. The smoking article may include an aerosol-generating material or an aerosol-forming substrate. In addition, the smoking article may include a solid material based on tobacco raw materials such as leaf tobacco, cut filler, and reconstituted tobacco. Smoking substances may contain volatile compounds. The smoking article may include several segments, each having a functional function, such segments as "... It is marked as “Part”. In the present specification, the smoking article may be not only a combustion type cigarette, but also a heating type cigarette used with an aerosol generating device (not shown) such as an electronic cigarette device.

In this specification, the terms "upstream" and "downstream" are terms used to denote the relative positions of the segments constituting the smoking article with respect to the direction in which the user draws air using the smoking article. The smoking article includes an upstream end (ie, a portion through which air enters) and an opposite downstream end (ie, a portion through which air exits). When using the smoking article, the user may bite the downstream end of the smoking article. The downstream end is located downstream of the upstream end, while the term “end” may also be described as “end”.

The present invention relates to a cigarette filter that can be applied to a smoking article. According to one embodiment of the present invention, the cigarette filter includes a lyocell tow made of a plurality of lyocell fibers, and the lyocell fibers. Includes a binder that binds to each other. The lyocell fiber is an eco-friendly fiber made of 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 one 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. By mixing a binder suitable for the lyocell fibers with a solvent to prepare a binder solution, spraying the binder solution on the lyocell tow, and then drying the lyocell tow, a structure having a certain level or higher hardness can be formed.

A cigarette filter comprising a lyocell tow according to one embodiment of the present invention has excellent hardness due to the binding of a binder and excellent durability against moisture. 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, 89% or more, 90% or more, 91% or more, or 91.5% or more. The hardness of the cigarette filter is a value obtained by quantifying 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 specifically calculated by Equation 1 below.

[Calculation 1]

Filter hardness (%)=[D-a]/D×100

Here, D is the filter diameter (mm), and a represents the distance (mm) that the 300g weight descends (the filter is pressed). Measurements necessary for calculating the hardness of the cigarette filter can be obtained using a device commonly used in the art, for example, DHT 200 ^TM from Filtrona can be used. In measuring the hardness, the applied force takes into consideration the force applied when the actual smoker grips the cigarette. The hardness value of 85% or more obtained through the cigarette filter according to one embodiment of the present invention can be secured at a level that can replace the conventional cigarette filter composed of cellulose acetate using lyocell tow, an eco-friendly material has technical significance.

The above-described hardness of the cigarette filter indicates the hardness when the smoker first grips the cigarette to smoke, and this hardness does not guarantee that the hardness of the cigarette filter is maintained until the smoker quits smoking. When a smoker smokes, a significant amount of moisture may flow into the cigarette filter, and it is easy to maintain the initial hardness when the filter including the lyocell tow has durability against moisture of a certain level or higher. Since the lyocell fiber is known as a hydrophilic material unlike hydrophobic-based cellulose acetate, it is not easy to maintain hardness due to the nature of the material. According to one embodiment of the present invention, the cigarette filter has a hardness of 80% or more even after 5 minutes after injecting 20 parts by weight to 25 parts by weight of water based on 100 parts by weight of lyocell tow. Specifically, the hardness of the cigarette filter after water is injected may be 80% or more, 81% or more, 82% or more, 83% or more, 84% or more, 85% or more, or 86% or more. After injecting water, the hardness of the cigarette filter was also measured in the same way as before injecting water. The determination of durability against moisture by measuring the hardness of the cigarette filter after water is injected takes into consideration the change in hardness of the cigarette filter until the smoker quits smoking. The amount of water injected or the elapsed time is taken into account the smoker's actual smoking, and the average amount of water contained in the cigarette filter after smoking by the smoker is 8 parts by weight on average. It is a harsh condition rather than a situation. The cigarette filter according to one embodiment of the present invention can maintain excellent hardness of 85% or more while the smoker is holding the cigarette during smoking.

By comparing the hardness before and after water injection, the water disintegration degree, which means the amount of change in hardness according to the injection of water, can be calculated. According to one embodiment of the present invention, the cigarette filter has a moisture decay rate of 7% or less. Specifically, the moisture disintegration of the cigarette filter may be 7% or less, 6.5% or less, 6% or less, 5.5% or less, or 5% or less. The water disintegration degree is basically based on the hardness before and after water is injected and can be calculated by Equation 2 below.

[Calculation 2]

Water decay rate (%)=(1-D ₂ /D ₁ )×100

Here, D ₁ means hardness (%) before water injection, and D ₂ means hardness (%) after water injection. The low water disintegration may be meaningful in that the hardness after water injection may be high, but from the smoker's point of view, it is also technically significant in that the change in tactile sensation felt from the cigarette filter during smoking is small.

According to one embodiment of the present invention, the binder includes polyester. The polyester has a function of imparting hardness to the lyocell tow by binding the lyocell fibers. Specifically, the polyester is a synthetic resin made by reacting a polyhydric organic acid with a polyhydric alcohol, and has appropriate resistance to water and various compounds. According to one embodiment of the present invention, the polyester has a weight average molecular weight of 1,000 to 50,000, specifically 1,500 to 30,000, more specifically 2,000 to 10,000. When it has a molecular weight less than the above range, resistance to water and the like may decrease, and when it has a molecular weight above the above range, it is not easy to properly disperse in lyocell tow.

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, so that the polyester containing the aromatic monomer and the aliphatic monomer easily adheres to other components such as Lyocell fibers as a binder. Functionality can be added. The aromatic monomer may be a polyhydric organic acid or a polyhydric alcohol, and similarly, the aliphatic monomer may also be a polyhydric organic acid or a polyhydric alcohol. The polyester exhibits low viscosity in an aqueous solution state and is easy to apply by spraying in an aqueous solution state. According to one embodiment of the present invention, the polyester has a viscosity of less than 5 cps, less than 4 cps, less than 3 cps, less than 2 cps at 40 ° C. with respect to a polyester aqueous solution having a concentration of 15% by weight. Here, the polyester aqueous solution at a concentration of 15% by weight means a solution obtained by mixing 15% by weight of polyester and 85% by weight of water.

According to one embodiment of the present invention, the aromatic monomer is a dicarboxylic acid having a C5 to C12 arylene group or heteroarylene group. Illustratively, the dicarboxylic acid having a C5 to C12 arylene group or 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 polyester, in that a carboxylic acid group and a hydroxy group can be formed by a condensation reaction at a ratio of 1: 1, as a monomer having a carboxylic acid group, the above-mentioned C5 to C12 arylene group or heteroarylene group A dicarboxylic acid having a dicarboxylic acid, a dicarboxylic acid having a C2 to C12 alkylene group, or a combination thereof may be used, and as a monomer having a hydroxyl group, a diol having a C1 to C6 alkylene group may be used. The arylene group, heteroarylene group or alkylene group exists in a substituted or unsubstituted state, and in the case of a substituted state, a C1 to C4 alkyl group, a C1 to C4 alkyl group in the main chain of the arylene group, heteroarylene group or alkylene group A substituent commonly known in the art, such as an alkoxy group and a halogen group, may be substituted.

The polyester may be contained in a solvent such as water and applied to the lyocell tow in the form of a binder solution, and then dried to remove part or all of the solvent. Even after drying, the polyester is positioned between the lyocell fibers to improve the hardness of the lyocell tow. According to one embodiment of the present invention, the polyester is included in 0.1 part by weight to 5 parts by weight based on 100 parts by weight of lyocell tow. Specifically, the content of the polyester is 0.1 parts by weight or more, 0.2 parts by weight or more, 0.3 parts by weight or more, 0.4 parts by weight or more, 5 parts by weight or less, 4.5 parts by weight or less, 4 parts by weight or less, 3.5 parts by weight or less, 3 parts by weight or less, 2.5 parts by weight or less, and may be 0.1 parts by weight to 5 parts by weight, 0.2 parts by weight to 4 parts by weight, or 0.3 parts by weight to 3 parts by weight. When the polyester is applied within the above range, the hardness can be raised to an appropriate level without deteriorating the function as a basic filter of the lyocell tow.

The binder may include other binder components together with polyester. As the other binder component, for example, hydroxyl propyl methyl cellulose (HPMC), hydroxyl propyl cellulose (HPC), poly vinyl alcohol (PVA), ethylene vinyl acetate (ethylene vinyl acetate, EVA), poly vinyl acetate (PVAc) or poly vinyl pyrrolidone (PVP) may be used. According to one embodiment of the present invention, the binder may further include hydroxypropyl methyl cellulose or polyvinyl pyrrolidone, specifically hydroxypropyl methyl cellulose together with polyester. The binder may produce a synergistic effect when used together with polyester in terms of functionality as a binder. According to one embodiment of the present invention, the weight ratio of polyester to hydroxypropyl methyl cellulose or polyvinyl pyrrolidone in the binder is 1:1 to 1:3. Specifically, the weight ratio of polyester to hydroxypropyl methyl cellulose or polyvinyl pyrrolidone is 1:1 to 1:3, 1:1.5 to 1:3, 1:2 to 1:3, 1:2 to 1: It may be 2.5. When the polyester is used together with other binder components, a synergistic effect can be obtained through the combination by adjusting the content ratio within the above range.

The above-described cigarette filter may be manufactured through the following manufacturing method. The manufacturing method includes preparing a lyocell tow using lyocell fibers, preparing a binder solution by mixing a binder and a solvent, spraying and drying the binder solution on the lyocell tow, and drying the lyocell. and wrapping the tow with wrapping paper to produce a cigarette filter. Since the manufacturing method basically relates to a method of manufacturing the above-described cigarette filter, description of the specific parts in the above description will be omitted, and the following will describe the characteristics of the manufacturing method in more detail.

First, a lyocell tow is prepared using a plurality of lyocell fibers. The manufactured lyocell tow has a bundle shape formed by cross-linking adjacent lyocell fibers. At this time, a step of inflating the tow through blooming is additionally performed. When the tow is inflated through the blooming step, the binder solution sprayed thereafter can easily penetrate between the lyocell fibers constituting the lyocell tow.

Thereafter, a binder solution is prepared by mixing a binder and a solvent. The binder solution is a material that is sprayed on the lyocell tow to improve functionality such as hardness of the lyocell tow. Since some components of the binder solution may be lost through a drying process after spraying, the composition of the binder solution may be different from the composition of the components constituting the cigarette filter. The binder can be embodied according to the above description, and since the component is not particularly lost after drying, the amount supplied to the lyocell tow through spraying remains in the final cigarette filter almost as it is. The solvent includes water, and some of the water is lost during the drying process. When the binder solution is prepared using only the binder and water, the portion of the binder solution excluding the binder content becomes the water content. According to one embodiment of the present invention, the binder is included in 5 parts by weight 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, 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, and may be 5 parts by weight to 40 parts by weight, 7 parts by weight to 30 parts by weight, or 10 parts by weight to 20 parts by weight. The binder is easy to apply to the lyocell tow by spraying when forming a binder solution within the above range.

The binder solution prepared according to the above is sprayed on the lyocell tow. The binder solution may be sprayed onto the lyocell tow to an extent capable of solving problems such as hardness of the material of the lyocell tow without deteriorating the function of the lyocell tow as a basic filter. According to one embodiment of the present invention, the binder solution is sprayed on the lyocell tow in an amount of 5 to 30 parts by weight based on 100 parts by weight of the lyocell tow. Specifically, the spray amount of the binder solution 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, 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, 20 parts by weight or less, and may be 5 parts by weight to 30 parts by weight, 7 parts by weight to 24 parts by weight, or 10 parts by weight to 20 parts by weight. When the binder solution is sprayed within the above range, functionality such as hardness of the lyocell tow can be improved. A method of spraying the binder solution may be a method commonly used in the art, and is not particularly limited. For example, spraying of the binder solution may utilize nozzle spraying, brush spraying, or electric spraying.

After the binder solution is sprayed on the lyocell tow, it is dried to secure hardness by reducing the amount of moisture. As a method of drying the lyocell tow, a method commonly used in the art may be used and is not particularly limited. Drying may be performed so that, for example, the amount of initially sprayed moisture can be reduced by 30% or more.

A cigarette filter is prepared by wrapping the dried lyocell tow with wrapping paper. If necessary, the lyocell tow may be processed into a size suitable for application to a cigarette filter using a mechanical roll or a cutter.

The tobacco filter described above can be applied to smoking articles. 1 provides a diagram showing the schematic configuration of a smoking article according to one embodiment of the present invention. The smoking article 100 includes a smoking substance portion 10 and a filter portion 20, and the above-described tobacco filter is applied to the filter portion 20 of the smoking article 100. In the smoking article 100, the smoking substance portion 10 is located upstream compared to the filter portion 20.

The smoking substance unit 10 may be filled with smoking substances such as raw leaf tobacco, leaf tobacco, or a mixture of leaf tobacco and leaf tobacco. The processed smoking material may be filled in the smoking material unit 10 in the form of a sheet or cut filler. The smoking material unit 10 may have a long elongated rod shape, and its length, circumference and diameter are not particularly limited, but a size generally used in the related art considering the filling amount of smoking material, user's preference, etc. can be adjusted with The smoking material part 10 may include at least one aerosol generating material selected from glycerin, propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol and oleyl alcohol. The smoking substance portion 10 may contain other additives such as flavoring agents, humectants and/or acetate compounds. The aerosol-generating substances and additives may be contained in smoking substances.

The filter unit 20 is disposed downstream of the smoking material unit 10 and serves as a filter through which the aerosol generated from the smoking material unit 10 passes immediately before the user inhales it. The filter unit 20 may be made of various materials or shapes. The filter unit 20 according to one embodiment of the present invention basically includes the above-described cigarette filter including a lyocell tow in which a plurality of lyocell fibers are bonded by a binder. The cigarette filter including the lyocell tow can replace all or part of the filter unit 20 of an existing smoking article, and in the case of partial replacement, the filter material previously used can be used together. Existing filter materials, for example, cellulose acetate filters, hollow tube filters, and the like may be used.

In FIG. 1 , the filter unit 20 is shown as a monofilter made of a single filter, but is not limited thereto. For example, the filter unit 20 may be provided with a dual filter or triple filter having two acetate filters to increase filter efficiency. In addition, although not shown, a crushable capsule (not shown) having a structure in which an inner liquid containing a fragrance is wrapped with a film may be included inside the filter unit 20 .

The outside of the smoking substance part 10 and the filter part 20 may be wrapped by a wrapper 30a or 30b.

The smoking substance portion 10 may be wrapped by a smoking substance portion wrapper 30a. Some of the cigarette smoke generated during the combustion process of the general smoking material part 10 is released into the air through the smoking material part wrapper 30a before passing through the cigarette filter, and the sidestream smoke gives secondhand smokers an unpleasant feeling. Various attempts have been made, such as adding fillers such as magnesium oxide, titanium oxide, cerium oxide, aluminum oxide, calcium carbonate, zirconium carbonate, etc. to cigarette paper to reduce sidestream smoke, but simply applying these fillers to reduce sidestream smoke gives a feeling of smoking. It has been difficult to solve the above problems through an appropriate combination of materials entering the filler, due to deterioration, burning off, deterioration of retrograde integrity, and the like. The smoking material part wrapper (30a) according to one embodiment of the present invention is magnesium oxide (MgO and/or Mg(OH) ₂ ) and calcium carbonate to reduce sidestream smoke and at the same time prevent a burning sensation, a deterioration in retrograde consistency, and burnout. (CaCO ₃ ) is applied as a mixed filler.

The filter unit 20 may be wrapped by a filter unit wrapper 30b. The filter unit wrapper 30b may be made of paper having oil resistance, and aluminum foil may be further included on the inner surface of the filter unit wrapper 30b.

The smoking substance portion 10 wrapped by the smoking substance portion wrapper 30a and the filter portion 20 wrapped by the filter portion wrapper 30b may be combined and packaged by the tip paper 40 . As shown in FIG. 1 , the tip paper 40 may be wrapped around at least a portion of the smoking material wrapper 30a (for example, a downstream portion) and the outside of the filter wrapper 30b. In other words, at least a portion of the smoking substance unit 10 and the filter unit 20 are further wrapped by the tip paper 40 and may be physically coupled. According to one embodiment of the present invention, the tip paper 40 may be made of non-porous paper that is not oil-resistant, but is not limited thereto. In addition, the tip paper 40 may prevent the filter unit 20 from burning by including an incombustible material, but is not limited thereto.

Hereinafter, the configuration of the present invention and its effects will be described in more detail through Examples and Comparative Examples. However, these examples are for explaining the present invention in more detail, and the scope of the present invention is not limited to these examples.

Example

Example 1

Lyocell tow having a tow fiber bundle of about 35,000 denier was used by using a lyocell fiber having a fiber length of about 3.0 denier. In addition, a binder solution, which is a mixture of a binder and a solvent, was prepared. Specifically, the binder solution is 15% by weight of polyester (a copolymer of phthalic acid, sebacic acid and ethylene glycol, weight average molecular weight (M _w ) = 3,000 to 6,000) based on the total weight of the binder solution, 85% by weight of water was prepared by adding The prepared binder solution was sprayed onto the lyocell tow through a nozzle spray. The binder solution was dried by spraying 15% by weight based on the weight of the lyocell tow. A cigarette filter having an axial length of about 108 mm and a circumference of about 24.20 mm was prepared by wrapping the dried lyocell tow with wrapping paper.

Example 2

A cigarette filter was prepared in the same manner as in Example 1, except that 3% by weight of polyester and 7% by weight of hydroxypropyl methyl cellulose (Pharmacoat 606) were used instead of 15% by weight of polyester in the binder solution.

Example 3

A cigarette filter was prepared in the same manner as in Example 1, except that 3% by weight of polyester and 7% by weight of polyvinylpyrrolidone (K25) were used instead of 15% by weight of polyester in the binder solution.

Comparative Example 1

A cigarette filter was prepared without spraying the binder solution on the lyocell tow.

Experimental example

Experimental Example 1: Hardness Evaluation of Cigarette Filters

The hardness of the cigarette filters prepared according to Examples 1 to 3 and Comparative Example 1 was measured. In addition, in order to measure the degree of disintegration of the cigarette filter by moisture, about 20 μl (22% by weight of lyocell tow) of water is injected into each cigarette filter with a syringe, and then the hardness of the cigarette filter is measured about 5 minutes later. did Specifically, the hardness of the cigarette filter was measured using a filter hardness measuring instrument (Filtrona's DHT 200 ^TM ) and the following formula 1.

[Calculation 1]

Filter hardness (%)=[D-a]/D×100

Here, D is the filter diameter, and a represents the distance (mm) that the 300 g weight descends (the filter is pressed).

	Hardness before water injection (%)	Hardness after water injection (%)	Water Decay (%)
Example 1	91.5	86.1	5.9
Example 2	91.5	87.0	4.9
Example 3	94.5	86.5	8.5
Comparative Example 1	84.7	77.4	8.6

* Water disintegration (%)=(1-D ₂ /D ₁ )×100

(Here, D ₁ means hardness (%) before water injection, and D ₂ means hardness (%) after water injection.)

According to Table 1, when polyester is included in the binder solution (Examples 1 to 3), the hardness before water injection is 85% or more, specifically 90% or more, and the hardness after water injection is 80% or more, specifically showed an excellent hardness of 85% or more. According to Examples 2 and 3, the polyester was able to maintain excellent hardness even when used in combination with other types of binders such as hydroxypropyl methyl cellulose and polyvinyl pyrrolidone.

In the above results, the hardness after water injection is a numerical value related to the minimum hardness until the smoker quits smoking, and when polyester is included as a binder (Examples 1 to 3), the smoker is 80% until the smoker quits smoking. Since the above hardness can be maintained, the structure of the cigarette filter may not feel collapsed during smoking. Nevertheless, when polyester alone or a combination binder of polyester and hydroxypropyl methyl cellulose was used (Examples 1 and 2), the degree of water decay was as low as 7% or less, specifically 6% or less, so that smokers felt cigarettes during smoking. The tactile change of the filter may be less.

On the other hand, when a binder solution such as polyester is not used (Comparative Example 1), a cigarette filter containing lyocell tow is very vulnerable to moisture, and the structure is deteriorated not only during smoking but also when stored under harsh conditions with some moisture. It may change and may not be desirable.

Experimental Example 2: Evaluation of viscosity and adhesion of binder solution

The viscosity and adhesive strength of the binder solutions used in Examples 1 and 2 were measured and are shown in Table 2 below. The viscosity was measured using a BrookField Spindle No.61 device under a temperature condition of 40 °C. The adhesive strength was obtained by applying the binder solution of Example 1 (15 wt % polyester and 85 wt % water) and the binder solution of Example 2 (3 wt % polyester, 7 wt % hydroxypropyl methyl cellulose and 90% by weight of water) were applied, respectively, and art paper having a basis weight of 100 gsm was laminated, dried, and then measured using a tensile machine (Tinius Olsen's Universal Testing Machine 10ST series).

	Viscosity (cps)	Adhesion (gf/mm 2 )
Binder solution of Example 1	2 cps or less	Unmeasurable (destruction of adherend)
Binder solution of Example 2	85	Unmeasurable (destruction of adherend)

According to Table 2, in the case of polyester included in the binder solution, although it is a material with a very low viscosity, it exhibited high adhesive strength enough to destroy the adherend during drying. The binder solution containing polyester has a low viscosity, so it can be easily dispersed and uniformly distributed in a target material such as lyocell tow, and after drying, it exhibits excellent adhesive strength and is suitable for imparting functionality such as hardness to lyocell tow. .

As described above, although the embodiments have been described with limited examples and drawings, those skilled in the art can make various modifications and variations from the above description. For example, the described techniques may be performed in an order different from the method described, and/or components of the described system, structure, device, circuit, etc. may be combined or combined in a different form than the method described, or other components may be used. Or even if it is replaced or substituted by equivalents, appropriate results can be achieved.

[Description of code]

10: Smoking material part

20: filter unit

30a: smoking material part wrapper

30b: filter unit wrapper

40: tip paper

100: smoking article

Claims (11)

1. Lyocell tow made of a plurality of lyocell fibers; and

   A binder for binding the lyocell fibers to each other; includes,

   A cigarette filter with a hardness of 85% or more.
2. The method of claim 1,

   The cigarette filter has a hardness of 80% or more even after 5 minutes after injecting 20 parts by weight to 25 parts by weight of water based on 100 parts by weight of lyocell tow.
3. The method of claim 2,

   The cigarette filter has a moisture decay rate of 7% or less.
4. The method of claim 1,

   The cigarette filter according to claim 1, wherein the binder comprises polyester.
5. The method of claim 4,

   The polyester is a cigarette filter, characterized in that the copolymer of an aromatic monomer and an aliphatic monomer.
6. The method of claim 4,

   The polyester is a cigarette filter, characterized in that the viscosity at 40 ℃ less than 5 cps with respect to a 15% by weight polyester aqueous solution.
7. The method of claim 5,

   The aromatic monomer is a cigarette filter, characterized in that dicarboxylic acid having a C5 to C12 arylene group or heteroarylene group.
8. The method of claim 5,

   The aliphatic monomer is a diol having a C1 to C4 alkylene group, a dicarboxylic acid having a C2 to C12 alkylene group, or a cigarette filter, characterized in that the combination thereof.
9. The method of claim 4,

   The polyester is a cigarette filter, characterized in that 0.1 to 5 parts by weight based on 100 parts by weight of lyocell tow.
10. The method of claim 4,

    The cigarette filter according to claim 1, wherein the binder further comprises hydroxypropyl methyl cellulose or polyvinyl pyrrolidone.
11. The method of claim 10,

    A cigarette filter, characterized in that the weight ratio of polyester and hydroxypropyl methyl cellulose or polyvinyl pyrrolidone in the binder is 1: 1 to 1: 3.

Images