Modified cross-section lyocell material, cigarette filter and manufacturing method thereof

Abstract

This application relates to a modified cross-section lyocell material, a cigarette filter containing the lyocell material, and a manufacturing method thereof. The lyocell material and the cigarette filter containing the same can replace conventional cellulose acetate materials and filters, and provide not only excellent biodegradability, but also excellent filter manufacturing processability and excellent cigarette properties (e.g., resistance to draw).

Description

[Technical Field]

[0001] The present invention relates to a modified cross-section lyocell material, a cigarette filter containing the same, and methods for producing the same. [Background technology]

[0002] Cellulose acetate fiber has been the primary material used for cigarette filters. Cellulose acetate is known to be a biodegradable substance, but cigarette filters made of cellulose acetate retain their original shape for one to two years after being buried in the soil, and it takes a considerable amount of time for them to fully biodegrade. Considering the amount and toxicity of tobacco products that are left in the living environment, as well as those that are collected and buried as waste after smoking, it is necessary to further improve the biodegradability of cigarette filters.

[0003] Since cigarettes are a luxury item enjoyed by inhaling the smoke produced when they are burned, the more uniform the concentration of the smoking smoke, the better the quality of the cigarette can be evaluated. One of the items that can be evaluated in relation to the uniformity of smoking smoke concentration is the resistance to draw of the filter, which is known to increase in proportion to the increase in the filtering efficiency of the filter. In other words, cigarette filters with excellent resistance to draw can be said to provide not only excellent filtering performance against harmful substances but also excellent user satisfaction (quality).

[0004] Therefore, there is a need to develop a filter material that can replace the conventional cellulose acetate material while achieving filter properties such as suction resistance at the same level or higher than those of conventional technologies. Summary of the Invention [Problem to be solved by the invention]

[0005] One object of the present application is to provide a lyocell material that can replace commercially available cellulose acetate for cigarette filters.

[0006] Another object of the present application is to provide a lyocell material for cigarette filters which is environmentally friendly in its manufacturing process and has excellent biodegradability when disposed of.

[0007] A further object of the present application is to provide a modified cross-section lyocell material having a predetermined shape or form so as to satisfy the degree of deformation and width ratio described below.

[0008] A further object of the present application is to provide a lyocell material for cigarette filters that satisfies or improves the properties (e.g., resistance to draw) of cigarette filter materials.

[0009] Yet another object of the present application is to provide a lyocell filter for cigarettes.

[0010] It is yet another object of the present application to provide a cigarette comprising a lyocell filter.

[0011] Yet another object of the present application is to improve the processability associated with the aforementioned lyocell material, filter and cigarette manufacturing.

[0012] The above and other objects of the present application can be achieved by the present invention, which will be described in detail below. [Means for solving the problem]

[0013] According to an embodiment of the present application, there are provided a modified cross-section lyocell material having a cross section of a predetermined shape (e.g., satisfying the degree of modification and width ratio described below), a cigarette filter containing the same, and methods for producing the same.

[0014] Specifically, as will be explained below, the inventors of the present application have confirmed that modified cross-section yarns that satisfy predetermined shapes and finenesses can provide excellent filtering functions (e.g., drawing resistance) because they provide a higher specific surface area than circular cross-section yarns, and have thus invented a lyocell material having the configuration described below, a cigarette filter containing the same, and a method for manufacturing the same.

[0015] The Lyocell material, the cigarette filter containing same, and the method for producing the same according to the present application are described in more detail below.

[0016] In one embodiment, the present application relates to a method for producing a lyocell material having a modified cross-section and a desired shape and fineness, which can be used to produce cigarette filters.

[0017] Specifically, the method includes the steps of spinning a lyocell dope using a modified cross-section forming spinneret having at least three projections, solidifying the spun lyocell dope to obtain a lyocell multifilament, treating the lyocell multifilament with an oil, and crimping the oil-treated lyocell multifilament into a crimping machine so that steam and pressure are applied to the lyocell multifilament. The lyocell multifilament (e.g., the oil-treated lyocell multifilament) produced through the steps has a total fineness of 15,000 to 45,000 denier, and the monofilament constituting the lyocell multifilament has a single yarn fineness of 1.5 to 8.0 denier.

[0018] The lyocell material produced by the above-mentioned method may have an irregular cross section. An irregular cross section refers to a cross section that is not circular but has a shape that includes multiple protrusions. For example, as shown in Figure 1, a cross section with multiple protrusions (e.g., three or more protrusions) extending from the center can be called an irregular cross section.

[0019] In one example, the modified cross-section lyocell material of the present application may have three or more protrusions branching out from a central portion. For example, the modified cross-section lyocell material may have a cross-sectional shape in which four, five, or more protrusions extend in different directions from the central portion.

[0020] Although not particularly limited, when there are three protrusions, the cross section may be Y-shaped, and when there are four protrusions, the cross section may be cross-shaped.

[0021] In a specific example of the present application, the modified cross section of the lyocell material produced by the above-mentioned method satisfies a predetermined modification degree and width ratio.

[0022] Specifically, each protrusion extending from the center has a shape such that the irregularity calculated by the following relational expression 1 is 0.6 or more, and the width ratio calculated by the following relational expression 2 is 0.5 to 2.0.

[0023] [Equation 1] Anomaly degree=L / W

[0024] [Equation 2] Width ratio = W1 / W2

[0025] In relation to the degree of irregularity, L refers to the length of the protrusion extending from the center or the length of the protrusion extending in the branching direction. Specifically, L refers to the length of the protrusion, and can be calculated as the distance (e.g., the longest distance or length) from the center of a line corresponding to the protrusion width connecting the two points where one protrusion meets the two protrusions directly adjacent to it to the end point of the protrusion (for which the length is to be calculated).

[0026] In relation to the irregularity, W refers to the width (or extent) of the protrusion. Specifically, when the protrusion length L determined as described above is used as a reference (i.e., when L is used as the reference line in Figure 1), W is calculated as the arithmetic mean (W = (W1 + W2) / 2) of the protrusion width W1 at a point corresponding to 10% of the reference line length and the protrusion width W2 at a point corresponding to 90% of the reference line length. When calculating the protrusion widths W, W1, and W2, the straight line used to calculate the widths W, W1, and W2 is also perpendicular to the protrusion length L.

[0027] In one example, the length and width of the protrusions used to calculate the degree of deformation are also arithmetic average values ​​obtained by calculating the length and width of each protrusion in the modified cross section of the monofilament and then dividing the length and width by the number of protrusions.

[0028] In the specific example of the present application, L is greater than W.

[0029] When the tow having the irregular cross section as described above is applied to a cigarette filter, it is possible to realize uniform filter characteristics (eg, drawing resistance, filter circumference).

[0030] In one example, the degree of deformation of the modified cross-section lyocell material (relationship 1) calculated as described above is 0.7 or more, 0.8 or more, 0.9 or more, 1.0 or more, 1.1 or more, 1.2 or more, 1.3 or more, 1.4 or more, 1.5 or more, 1.6 or more, 1.7 or more, 1.8 or more, 1.9 or more, 2.0 or more, 2.1 or more, 2.2 or more, 2.3 or more, 2.4 or more, or 2.5 or more, and its upper limit is, for example, 4.0 or less, 3.5 or less, specifically 3.0 or less, 2.9 or less, 2.8 or less, 2.7 or less, 2.6 or less, 2.5 or less, 2.4 or less, 2.3 or less, 2.2 or less, 2.1 or less, or 2.0 or less.

[0031] In one example, the width ratio of the lyocell material calculated as above (Relationship 2) is 0.6 or more, 0.7 or more, 0.8 or more, 0.9 or more, 1.0 or more, 1.1 or more, 1.2 or more, 1.3 or more, 1.4 or more, 1.5 or more, 1.6 or more, 1.7 or more, or 1.8 or more, and its upper limit is 1.9 or less, 1.8 or less, 1.7 or less, 1.6 or less, 1.5 or less, 1.4 or less, 1.3 or less, 1.2 or less, or 1.1 or less.

[0032] Modified cross-section fibers that satisfy the above-mentioned irregularity and width ratio can increase the surface area and improve tobacco smoke removal performance compared to the use of circular cross-section fibers or modified cross-section fibers that cannot satisfy the above-mentioned irregularity and width ratio.

[0033] Furthermore, if the irregularity (relationship 1) and width ratio (relationship 2) are smaller than the aforementioned values, the specific surface area will gradually converge to a circular cross-sectional area, making it impossible to ensure a sufficient specific surface area. Furthermore, if the irregularity (relationship 1) and width ratio (relationship 2) are greater than the aforementioned values, even if the same or similar amount (e.g., g) of filaments are packed when manufacturing a cigarette filter, the effect of imparting a large specific surface area, which is a characteristic of an irregular cross-section, will be reduced, making it difficult to achieve filter properties (e.g., drawing resistance).

[0034] The method for producing a lyocell material according to the present invention will be described in detail below.

[0035] (a) Lyocell dope spinning stage The step involves spinning a lyocell spinning dope, i.e., a lyocell dope containing cellulose (or cellulose pulp) and N-methylmorpholine-N-oxide (NMMO), using a profiled spinneret having at least three projections.

[0036] The type or design of a spinneret capable of forming a modified cross section having at least three protrusions is not particularly limited. For example, a spinneret having a shape corresponding to three or more protrusions may be used. Alternatively, a spinning device having a plurality of unit holes each having at least three adjacent holes may be used so that three or more protrusions can be formed.

[0037] Commercially available cellulose acetate filters have been identified as a major source of microplastic emissions. However, the amine oxide solvent used in the production of lyocell fibers can be reused and is biodegradable upon disposal, meaning that lyocell materials do not generate any pollutants during their production process. Furthermore, lyocell tow is biodegraded and removed within a relatively short period of time, making lyocell a more environmentally friendly material than cellulose acetate.

[0038] In one example, the cellulose content in the spinning dope is 5 to 15 wt% based on the total weight of the dope (100 wt%). If the cellulose content is too low, it is difficult to achieve the properties of lyocell fiber, and if the cellulose content exceeds this range, it is difficult to dissolve in a solvent. In consideration of this, the cellulose content in the spinning dope is 6 wt% or more, 7 wt% or more, 8 wt% or more, 9 wt% or more, or 10 wt% or more, with the upper limit being, for example, 14 wt% or less, 13 wt% or less, 12 wt% or less, 11 wt% or less, 10 wt% or less, or 9 wt% or less.

[0039] In one example, the spinning dope includes an aqueous solution of N-methylmorpholine-N-oxide (NMMO), which may contain, for example, 80 to 95 parts by weight of N-methylmorpholine-N-oxide (NMMO) and 5 to 20 parts by weight of water, taking into consideration the degree of dissolution of cellulose and the process temperature.

[0040] In one example, the cellulose or cellulose pulp has an α-cellulose content of 85 to 97% by weight relative to 100% by weight of the total cellulose.

[0041] In a specific example of the present application, the degree of polymerization (DPw) of the cellulose is also 600 to 1,700.

[0042] The nozzle temperature of the spinneret, specifically, the spinning temperature, can be appropriately selected by those skilled in the art. Taking into consideration that the viscosity of the spinning dope varies depending on the spinning temperature, and that the extrusion may not be performed well, the spinning temperature may be, for example, 100°C to 120°C or 100°C to 110°C.

[0043] In one example, the spinning step may be performed under spinning conditions controlled to satisfy the monofilament and / or multifilament fineness. For example, the spinning dope may be performed under spinning conditions controlled to achieve a filament fineness of 1.5 to 8.0 denier. For example, by appropriately controlling one or more spinning conditions selected from the spinning dope throughput and the spinning speed, the filament fineness of the filament forming the lyocell material may be in the range of 1.5 to 8.0 denier. In this case, the filament fineness refers to the fineness of a single monofilament separated from a multifilament. In addition, the total fineness may be controlled within a predetermined range by adjusting the number of filaments, as needed.

[0044] Specifically, the filament fineness is, for example, 7.5 denier or less, 7.0 denier or less, 6.5 denier or less, 6.0 denier or less, 5.5 denier or less, 5.0 denier or less, or 4.5 denier or less. The lower limit is, for example, 2.0 denier or more, 2.5 denier or more, 3.0 denier or more, 3.5 denier or more, 4.0 denier or more, 5.0 denier or more, 5.5 denier or more, or 6.0 denier or more. Satisfying the above ranges is advantageous for achieving stable drawing resistance of the cigarette filter and ensuring processability.

[0045] The spinning dope discharged through the spinneret undergoes a coagulation stage, which will be described later.

[0046] (b) Coagulation step and obtaining multifilaments In this step, the spun lyocell spinning dope is solidified to obtain lyocell multifilaments.

[0047] The coagulation may be carried out by contacting the spinning dope with air and / or a coagulation liquid.

[0048] In one example, the coagulation step includes a primary coagulation step in which cooling air is supplied to the spun lyocell dope, and a secondary coagulation step in which the primarily coagulated spinning dope is introduced into a coagulation liquid to coagulate it.

[0049] By the solidification method described above, the lyocell dope discharged from the spinneret can be primarily solidified in the space (air gap section) between the spinneret and the solidification bath. For example, cooling air can be supplied to such an air gap section from the inside to the outside of the spinneret from an air cooling section located inside the spinneret. Alternatively, primary solidification can be performed by a so-called air quenching method or means known in the related field.

[0050] In one example, the upper limit of the temperature of the cooling air used for the primary solidification is, for example, 15° C. or less. Specifically, the cooling air may be air having a temperature of 14° C. or less, 13° C. or less, 12° C. or less, 11° C. or less, or 10° C. If the temperature exceeds the above range, the spinning dope may not be sufficiently solidified by air, resulting in poor spinning processability.

[0051] The lower limit of the cooling air temperature can be determined in consideration of the spinning process and / or the cross-sectional uniformity of the filaments. For example, if the temperature of the cooling air is less than 4°C, the surface of the spinneret becomes cold, the surface of the filaments becomes uneven, and the spinning process also deteriorates. Taking this into consideration, the cooling air temperature can be 5°C or more, 6°C or more, 7°C or more, 8°C or more, or 9°C or more.

[0052] The amount of cooling air supplied can be adjusted in consideration of sufficient solidification, spinning processability, and effects on the physical properties of the filaments. For example, the amount of cooling air supplied to the spinning dope is adjusted to 70 to 300 Nm. 3 More specifically, the air volume is 100 Nm 3 / h or more or 150Nm 3 / h or more, and the upper limit of the air volume is, for example, 250Nm 3 / h or less or 200Nm 3 / h or less.

[0053] After the primary coagulation, the cooled spinning dope may be supplied to a coagulation tank or bath containing a coagulation liquid (secondary coagulation). For proper coagulation, the temperature of the coagulation liquid may be, for example, 30°C or less or 25°C or less. The temperature of the coagulation liquid may be 10°C or more, 15°C or more, or 20°C or more. Maintaining these temperatures allows for proper coagulation rate.

[0054] The type of coagulation liquid for the secondary coagulation is not particularly limited, and may include, for example, one or more of water and N-methylmorpholine-N-oxide (NMMO).

[0055] Although not particularly limited, when the coagulation liquid contains water and N-methylmorpholine-N-oxide (NMMO), the water content in the coagulation liquid is 60 to 90 wt % and the N-methylmorpholine-N-oxide (NMMO) content is 10 to 40 wt %. Alternatively, the coagulation liquid may contain 70 to 80 wt % water and 20 to 30 wt % N-methylmorpholine-N-oxide (NMMO). The concentration of such a coagulation liquid can be controlled to be maintained throughout the manufacturing process using a sensor light.

[0056] (c) Water washing stage If necessary, after the coagulation step and the multifilament step, the multifilament may be washed with water to remove N-methylmorpholine-N-oxide (NMMO) and / or other impurities remaining in the filaments.

[0057] The method of washing with water is not particularly limited. For example, washing with water can be performed by using a pulling roller and introducing the solidified lyocell multifilament into a washing tank. Alternatively, washing with water can be performed by spraying a washing liquid onto the multifilament during the process of moving to the next stage by the pulling roller.

[0058] The components of the washing liquid are not particularly limited. For example, the washing liquid may contain water and other known additives.

[0059] In addition, in consideration of reuse after washing, the washing liquid may be adjusted to a temperature of 100° C. or less.

[0060] (d) Oil treatment stage This step applies an oil to the surface of the filament to reduce friction applied to the filament and to allow a good crimp to be formed in the crimping step described below.

[0061] Although not particularly limited, the oil treatment may be performed by immersing the multifilament in a bath filled with oil so that the multifilament is completely immersed in the oil. Alternatively, the oil treatment may be performed by spraying an oil solution during the process of moving the multifilament to the next stage by a pulling roller.

[0062] After the oil treatment as described above, a process of squeezing out the oil from the surface of the multifilament using a roll or the like positioned before and / or after the oil treatment step may be additionally performed so that the amount of oil applied to the multifilament becomes uniform.

[0063] In one example, the oil treatment is performed so that the content of the oil is about 5% by weight or less, based on 100% by weight of the oil-treated multifilament. Specifically, the amount of oil in the oil-treated multifilament is 4% by weight or less, 3% by weight or less, or 2% by weight or less, and is 0.5% by weight or more, 1% by weight or more, or 2% by weight or more.

[0064] The type of oil that can be used is not particularly limited, and any oil known in the related technical field can be used.

[0065] Optionally, after the oil treatment as described above, the oil may be dried.

[0066] In an embodiment of the present application, one or more of the above steps may be performed under controlled conditions to satisfy the above-mentioned monofilament and / or multifilament fineness, where the single filament fineness refers to the fineness of a single monofilament separated from a multifilament.

[0067] Specifically, the filament single-filament fineness is, for example, 7.5 denier or less, 7.0 denier or less, 6.5 denier or less, 6.0 denier or less, 5.5 denier or less, 5.0 denier or less, 4.5 denier or less, 4.0 denier or less, 3.5 denier or less, or 3.0 denier or less. The lower limit is, for example, 2.0 denier or more, 2.5 denier or more, 3.0 denier or more, 3.5 denier or more, or 4.0 denier or more. As will be seen in the comparative examples described below, if the filament single-filament fineness is outside the above-mentioned range, the draw resistance of the cigarette filter may be significantly reduced.

[0068] Although not particularly limited, the step controlled to ensure the above-mentioned range of fineness may be the spinning step, or all of the spinning, coagulation, water washing, and oil treatment steps may be controlled to ensure the above-mentioned range of single filament fineness.

[0069] (e) Crimping step The crimping step is a step in which steam and pressure are applied to the oil-treated lyocell multifilament to obtain a crimped tow, and may be referred to as a crimping step.

[0070] Through crimping, waves can be imparted to the multifilament, and the fibers can have bulky properties. Crimping can be performed using known crimping devices, such as a stuffer box and / or a steam box. The crimping device that can be used is not particularly limited, as long as it is capable of applying steam pressure and roll pressure, as described below.

[0071] In one example, the crimping step may be performed by first supplying steam to the lyocell multifilament to preheat and swell the multifilament, and then pressing the multifilament with a press roller to form wrinkles in the multifilament. In this case, a steam box is used to supply steam, and the steam box may be located at the front end of the crimping device.

[0072] In one example, the crimping step may be performed by simultaneously pressing the multifilaments with a press roller and applying steam.

[0073] In one example, the crimping step can be performed by first supplying steam to the lyocell multifilament to preheat and swell the multifilament, and then simultaneously pressing the multifilament with a press roller and applying steam.

[0074] In one example, the crimping step is performed by applying a pressure of 0.1 to 2.0 kgf / cm to the multifilament before it is fed into a crimping device (specifically, a press roller). 2In the specific example of the present application, the steam is added at 0.2 kgf / cm 2 More than 0.3kgf / cm 2 Over 0.4kgf / cm 2 More than 0.5kgf / cm 2 or more than 0.6kgf / cm 2 More than 1.5 kgf / cm can be provided by the steam box. 2 Below, 1.4kgf / cm 2 Below, 1.3kgf / cm 2 Below, 1.2kgf / cm 2 Below, 1.1kgf / cm 2 or less than 1.0kgf / cm 2 The following steam may be provided: If the steam supply amount or pressure is less than the above range, the crimp will not be formed smoothly; if it is more than the above range, the filaments will be too flexible and will be excessively crimped in the crimping device, making it impossible for the filaments to pass through the crimping device.

[0075] In one example, the crimping step uses a roller to apply a pressure of 1.5 to 4.0 kgf / cm to the multifilament fed into the crimping device. 2 In the specific example of the present application, the pressure is 1.6 kgf / cm. 2 More than 1.7kgf / cm 2 Above, 1.8kgf / cm 2 Over 1.9kgf / cm 2 Over 2.0kgf / cm 2 Above, 2.1kgf / cm 2 Above, 2.2kgf / cm 2 Above, 2.3kgf / cm 2 Over 2.4kgf / cm 2 or more than 2.5kgf / cm 2 The pressure above 3.9 kgf / cm can be applied to the multifilament through a press roller. 2 Below, 3.8kgf / cm 2 Below, 3.7kgf / cm 2Below, 3.6kgf / cm 2 Below, 3.5kgf / cm 2 Below, 3.4kgf / cm 2 Below, 3.3kgf / cm2 or below, 3.2kgf / cm 2 Below, 3.1kgf / cm 2 Below, 3.0kgf / cm 2 Below, 2.9kgf / cm 2 Below, 2.8kgf / cm 2 Below, 2.7kgf / cm 2 Below, 2.6kgf / cm 2 or less than 2.5kgf / cm 2 The following pressures can be applied. If the roller pressure is below this range, the desired number of crimps will not be formed sufficiently. If the roller pressure exceeds this range, the pressing force will be too strong, and the filament will not be able to be smoothly fed into the crimping device or pass through the stuffer box. The press rollers that provide this pressure may cause wrinkles to form in the multifilament.

[0076] In one example, a doctor blade that applies a predetermined pressure to the multifilament may be used in the crimping step. The doctor blade adjusts the residence time of the filament fed into the crimper box and contributes to the number of crimps (which affects the quality and filter performance of the tow). For example, such a doctor blade may be located in the path of the multifilament that is discharged at the roller pressure point after being pressed by the roller.

[0077] In a specific example of the present application, the crimping step uses a doctor blade to apply a pressure of 0.1 to 2.0 kgf / cm to the multifilament that has passed through the rollers of the crimping device. 2 The doctor blade may be positioned in the path of travel of the multifilament that is discharged at the roller pressure point after being pressed by the roller. In a specific example of the present application, the pressure applied by the doctor blade is 0.2 kgf / cm. 2More than 0.3kgf / cm 2 Over 0.4kgf / cm 2 or more than 0.5kgf / cm 2 The upper limit of the pressure is, for example, 1.5 kgf / cm. 2 Below, 1.4kgf / cm 2 Below, 1.3kgf / cm 2 Below, 1.2kgf / cm 2 Below, 1.1kgf / cm 2 or less than 1.0kgf / cm 2 Also the following:

[0078] In one example, the crimping step may be performed at a temperature ranging from 120°C to 250°C. If the temperature is too low, the shape stability of the crimp may be poor, and if the temperature is too high, the concentration of retaining substances may increase in the stuffer box, making crimping difficult. Therefore, taking into consideration the steam pressure, the temperature may be appropriately controlled within a range of 130°C or higher, 140°C or higher, or 150°C or higher, and 200°C or lower, 180°C or lower, or 160°C or lower.

[0079] In one example, the crimping step may be performed to satisfy a crimp draft ratio expressed by the following Equation 1. The pressure applied to the filament fed into the crimping device may also be exerted by a roller.

[0080] [Formula 1] 1.01≦crimp draft ratio≦1.30

[0081] In Equation 1, the crimp draft ratio is calculated by V1 / V0, where V0 means the moving speed of the oil-treated multifilament before it is fed into the crimping device, and V1 means the passing speed of the filament gripped by the rollers in the crimping device. Here, the passing speed may mean the speed at which the multifilament is fed into the crimping step (or fed into the crimping device) and moves between the steam step and / or the press roller step.

[0082] A method performed under the above conditions can impart uniform crimps to the tow. For example, as confirmed in the experiments described below, the upper and lower limits of the range of the number of crimps in the tow, calculated by arithmetic average, of the tow of the embodiment manufactured under conditions satisfying Equation 1 are closer to each other than those of the comparative example (i.e., ensuring uniformity of the tow). Furthermore, the uniformly formed crimped tow manufactured under conditions satisfying Equation 1 ensures a regular arrangement of fibers or fiber strands when manufactured into a cigarette filter. This can provide a high level of resistance to draw, as described below.

[0083] Furthermore, a method performed under the condition of satisfying Equation 1 is also advantageous in imparting a good crimp, deformation degree, and width ratio to the tow. Crimped tow with a good shape and having a deformation degree and width ratio that satisfy the above ranges functions advantageously in improving resistance to attraction.

[0084] On the other hand, if the range of Equation 1 is not satisfied, the tow production conditions are inappropriate, and either the tow cannot be produced, or even if the tow can be produced, the crimp shape produced is poor and the tow is non-uniform, resulting in poor cigarette filter production processability, and as a result, it is difficult to provide a filter with excellent draw resistance.

[0085] (f) Other stages After crimping, any appropriate post-processing can be performed.

[0086] In one example, a secondary oil treatment (g) may be additionally performed. This secondary oil treatment may prevent static electricity from being generated in the tow and may impart flexibility to the tow. This secondary oil treatment may be the same as or similar to the oil treatment step (d) described above.

[0087] In one example, a drying step (h) may be additionally performed. The drying may be performed, for example, at a temperature ranging from 100°C to 130°C. The drying method or mode is not particularly limited, and known techniques may be used. For example, the drying may be performed by applying hot air to the tow, or by leaving the tow in or passing it through a temperature-controlled room for a certain period of time.

[0088] According to a specific example of the present application, a tow having 20 to 50 crimps formed per inch can be provided by a method including the crimping step described above. For example, the number of crimps can be 25 ea / inch or more, 30 ea / inch or more, 35 ea / inch or more, 40 ea / inch or more, or 45 ea / inch or more, with the upper limit being, for example, 45 ea / inch or less, 40 ea / inch or less, 35 ea / inch or less, 30 ea / inch or less, or 25 ea / inch or less. The number and uniformity of the crimps can be controlled by the crimping step described above, for example, the crimp draft ratio. The crimped tow produced by the method of the present application not only has the number of crimps described above, but also has the crimps formed uniformly, so that when it is manufactured into a cigarette filter, it can provide a high level of resistance to draw, as described below.

[0089] According to the present application, a Lyocell material (crimped tow) having a fineness appropriate for manufacturing cigarette filters and ensuring their functionality can be provided. For example, a crimped tow having a total fineness of 15,000 to 45,000 denier can be provided. For example, the lower limit of the total fineness can be 16,000 or more, 17,000 or more, 18,000 or more, 19,000 or more, or 20,000 or more, and the upper limit can be, for example, 40,000 or less, 35,000 or less, 30,000 or less, or 25,000 or less. If the total fineness is outside the above range, a sufficient amount of filaments cannot be packed into the filter paper, which can deteriorate the physical properties of the filter (e.g., drawing resistance, etc.). Alternatively, if the total fineness of the tow is outside the above-mentioned range, the amount of tow packed into the filter wrapper may be excessively large, which may cause the filter wrapper to tear or make it difficult to adjust the tow packing amount to achieve the suction resistance required for the filter.

[0090] In a specific example of the present application, the fineness of the lyocell multifilament can be controlled to an appropriate value depending on the circumferential size of the filter.

[0091] For example, when the lyocell material is used in an (ultra) slim filter (e.g., the circumference of the filter rod is 19 mm or less), the total fineness of the lyocell multifilaments may be in the range of 15,000 to 25,000 denier. Specifically, the total fineness of the lyocell multifilaments used in the ultra-slim filter is 16,000 denier or more, 17,000 denier or more, 18,000 denier or more, 19,000 denier or more, 20,000 denier or more, 21,000 denier or more, 22,000 denier or more, 23,000 denier or more, or 24,000 denier or more, and 24,000 denier or less, 23,000 denier or less, 22,000 denier or less, 21,000 denier or less, 20,000 denier or less, 19,000 denier or less, 18,000 denier or less, 17,000 denier or less, or 16,000 denier or less. In such a case, the single yarn fineness of the lyocell monofilament is 4.5 denier or more, for example, 5.0 denier or more, 5.5 denier or more, 6.0 denier or more, 6.5 denier or more, 7.0 denier or more, or even 7.5 denier or more.

[0092] In another example, when the lyocell material is used in a regular-type filter (e.g., a filter rod having a circumference of 19 mm or more), the total fineness of the lyocell multifilaments is in the range of 25,000 to 45,000 denier. Specifically, the total fineness of the lyocell multifilaments used in a regular-type filter is 26,000 or more, 27,000 or more, 28,000 or more, 29,000 or more, 30,000 or more, 31,000 or more, 32,000 or more, 33,000 or more, 34,000 or more, 35,000 or more, 36,000 or more, 37,000 or more, 38,000 or more, 39,000 or more, 40,000 or more, 41,000 or more, 42,000 or more, 43,000 or more. or 44,000 or more, and also 44,000 or less, 43,000 or less, 42,000 or less, 41,000 or less, 40,000 or less, 39,000 or less, 38,000 or less, 37,000 or less, 36,000 or less, 35,000 or less, 34,000 or less, 33,000 or less, 32,000 or less, 31,000 or less, 30,000 or less, 29,000 or less, 28,000 or less, 27,000 or less, or 26,000 or less. In such cases, the single yarn fineness of the lyocell monofilament is 5.0 denier or less, for example, 4.5 denier or less, 4.0 denier or less, 3.5 denier or less, 3.0 denier or less, 2.5 denier or less, or 2.0 denier or less.

[0093] As described above, the present application can provide a lyocell material having a total fineness within the above range, specifically, a fineness that can ensure a wide range of filter performance suitable for regular filters and (ultra) slim filters. The total fineness of the tow can be determined by the single filament fineness and the number of crimps. In the method of the present application, as described above, the single filament fineness and the number of crimps are controlled, thereby ensuring the total fineness of the tow that is suitable for producing cigarette filters and ensuring their functionality.

[0094] In another embodiment of the present application, the present application relates to a modified cross-section lyocell material. The modified cross-section lyocell material can be produced by, for example, the above-described method for producing a modified cross-section lyocell material. Specifically, the modified cross-section lyocell material can be produced through the above-described steps of spinning, coagulation, washing, oil treatment, and crimping.

[0095] Specifically, the modified cross-section lyocell material is also a crimped tow produced by crimping a lyocell multifilament, wherein the lyocell multifilament includes monofilaments with a modified cross-section, and the total fineness of the monofilaments constituting the lyocell multifilament is 15,000 to 45,000 denier, and the single yarn fineness of the monofilaments constituting the lyocell multifilament is 1.5 to 8.0 denier.

[0096] The modified cross section of the monofilament may have at least three protrusions, and the protrusions may have a degree of deformation of 0.6 or more and a width ratio of 0.5 to 2.0. Specific values ​​related to these are as described above. Similarly to the above, the degree of deformation and the width ratio may be calculated as follows:

[0097] [Equation 1] Anomaly degree=L / W

[0098] [Equation 2] Width ratio = W1 / W2

[0099] In the above Relations 1 and 2, L represents the length of the protrusion and is calculated as the distance from the center of a line connecting the two points where one protrusion meets the two protrusions directly adjacent to it to the end point of the protrusion. W represents the width of the protrusion and is calculated as the arithmetic mean of the protrusion width W1 at a point corresponding to 10% of the length L and the protrusion width W2 at a point corresponding to 90% of the length L. The details are as described above.

[0100] In one example, the lyocell material is manufactured through a process that satisfies at least the following mathematical formula 1:

[0101] Specifically, the lyocell material is or includes a crimped tow that is fed into a crimping device so that the crimp can be given under the condition that satisfies the crimp draft ratio expressed in the following mathematical formula 1.

[0102] [Formula 1] 1.01≦crimp draft ratio≦1.30

[0103] In the above formula 1, the crimp draft ratio is calculated by V1 / V0, where V0 means the moving speed of the multifilament before it is fed into the crimping device, and V1 means the passing speed of the filament gripped by the rollers in the crimping device.

[0104] In one example, the tow may have 20 to 50 crimps per inch, the specific values ​​being as described above.

[0105] In one example, the tow, i.e., the crimped lyocell multifilament, has a total fineness of 15,000 to 45,000 denier. For example, the lyocell multifilament has a total fineness of 15,000 to 25,000 denier, or 25,000 to 45,000 denier. Specific values ​​are as described above.

[0106] In one example, the monofilament constituting the lyocell multifilament has a single yarn fineness of 1.5 to 8.0 denier, the specific values ​​of which are as described above.

[0107] As described above, in the specific example of the present application, the fineness of the lyocell multifilament can be controlled to an appropriate value depending on the circumferential size of the filter.

[0108] For example, when the lyocell material is used in an (ultra) slim filter (e.g., the circumference of the filter rod is 19 mm or less), the total fineness of the lyocell multifilaments may be in the range of 15,000 to 25,000 denier. Specifically, the total fineness of the lyocell multifilaments used in the ultra-slim filter is 16,000 denier or more, 17,000 denier or more, 18,000 denier or more, 19,000 denier or more, 20,000 denier or more, 21,000 denier or more, 22,000 denier or more, 23,000 denier or more, or 24,000 denier or more, and 24,000 denier or less, 23,000 denier or less, 22,000 denier or less, 21,000 denier or less, 20,000 denier or less, 19,000 denier or less, 18,000 denier or less, 17,000 denier or less, or 16,000 denier or less. In such a case, the single yarn fineness of the lyocell monofilament is 4.5 denier or more, for example, 5.0 denier or more, 5.5 denier or more, 6.0 denier or more, 6.5 denier or more, 7.0 denier or more, or even 7.5 denier or more.

[0109] In another example, when the lyocell material is used in a regular-type filter (e.g., a filter rod having a circumference of 19 mm or more), the total fineness of the lyocell multifilaments is in the range of 25,000 to 45,000 denier. Specifically, the total fineness of the lyocell multifilaments used in a regular-type filter is 26,000 or more, 27,000 or more, 28,000 or more, 29,000 or more, 30,000 or more, 31,000 or more, 32,000 or more, 33,000 or more, 34,000 or more, 35,000 or more, 36,000 or more, 37,000 or more, 38,000 or more, 39,000 or more, 40,000 or more, 41,000 or more, 42,000 or more, 43,000 or more. or 44,000 or more, and also 44,000 or less, 43,000 or less, 42,000 or less, 41,000 or less, 40,000 or less, 39,000 or less, 38,000 or less, 37,000 or less, 36,000 or less, 35,000 or less, 34,000 or less, 33,000 or less, 32,000 or less, 31,000 or less, 30,000 or less, 29,000 or less, 28,000 or less, 27,000 or less, or 26,000 or less. In such cases, the single yarn fineness of the lyocell monofilament is 5.0 denier or less, for example, 4.5 denier or less, 4.0 denier or less, 3.5 denier or less, 3.0 denier or less, 2.5 denier or less, or 2.0 denier or less.

[0110] Thus, according to the present application, a Lyocell material with a controlled total fineness can be provided so as to ensure a wide range of filter performance suitable for regular filters and ultra-slim filters.

[0111] The rest of the explanation regarding the lyocell material is the same as that of the manufacturing method of the lyocell material, so it will be omitted.

[0112] In yet another embodiment of the present application, the present application relates to a method for producing a cigarette filter, which includes any of the methods for producing a modified cross-section lyocell material described above.

[0113] Specifically, the method includes the steps of spinning a lyocell dope using a modified cross-section forming spinneret having at least three protrusions, solidifying the spun lyocell dope to obtain a lyocell multifilament, treating the lyocell multifilament with an oil agent, feeding the oil-treated lyocell multifilament into a crimping device to apply steam and pressure to the lyocell multifilament, and manufacturing a filter using the crimped tow.

[0114] In addition, in the manufacturing method of the cigarette filter (specifically, the manufacturing process of the lyocell material), one or more of the steps may be performed under controlled conditions so that the total fineness of the lyocell multifilament is 15,000 to 45,000 denier and the single yarn fineness of the monofilament constituting the lyocell multifilament is 1.5 to 8.0 denier.

[0115] Among the steps related to the manufacturing method of the cigarette filter, those steps that overlap with those described in the above-mentioned Lyocell material will be omitted because the contents are the same.

[0116] In the above-described method, the modified cross-section lyocell material used in the filter manufacturing step can also be a crimped tow produced by crimping a lyocell multifilament. The lyocell multifilament includes a monofilament with a modified cross-section, the lyocell multifilament having a total fineness of 15,000 to 45,000 denier, and the monofilament constituting the lyocell multifilament having a single yarn fineness of 1.5 to 8.0 denier. The modified cross-section may have at least three protrusions, each of which may have a degree of deformation of 0.6 or more and a width ratio of 0.5 to 2.0. The specific values ​​for these are as described above. Similarly, the degree of deformation and width ratio may be calculated as follows:

[0117] [Equation 1] Anomaly degree=L / W

[0118] [Equation 2] Width ratio = W1 / W2

[0119] In the above Relations 1 and 2, L represents the length of the protrusion and is calculated as the distance from the center of a line connecting the two points where one protrusion meets the two protrusions directly adjacent to it to the end point of the protrusion. W represents the width of the protrusion and is calculated as the arithmetic mean of the protrusion width W1 at a point corresponding to 10% of the length L and the protrusion width W2 at a point corresponding to 90% of the length L. The details are as described above.

[0120] In one example, the crimping step may be performed to satisfy a crimp draft ratio expressed in Equation 1 below.

[0121] [Formula 1] 1.01≦crimp draft ratio≦1.30

[0122] In the above Equation 1, the crimp draft ratio is calculated by V1 / V0, where V0 means the moving speed of the oil-treated multifilament before it is fed into the crimping device, and V1 means the passing speed of the filament gripped by the rollers in the crimping device.

[0123] In one example, the tow may have 20 to 50 crimps per inch. The specific description is the same as that described above, so it will be omitted.

[0124] The filter manufacturing step performed after the crimping step can be appropriately performed by those skilled in the art using known methods. For example, a filter can be manufactured by forming a rod-shaped wrapper paper (which can also be called a wrapper paper, filter paper, or filter wrapper paper) filled with tow. Alternatively, a filter can be manufactured by cutting a rod-shaped tow-filled filter paper to an appropriate length.

[0125] The wrapper paper is a porous or non-porous paper that can cover and wrap the lyocell tow (i.e., tow that has been at least oil-treated and crimped) and maintain the filter shape (e.g., columnar or cylindrical).

[0126] In one example, when a porous wrapper paper is used, the wrapper paper may have a porosity of 10 to 50,000 CU (coresta units). Specifically, the lower limit of the porosity of the wrapper paper is, for example, 1,000 CU or more, 5,000 CU or more, 10,000 CU or more, 15,000 CU or more, 20,000 CU or more, 25,000 CU or more, 30,000 CU or more, 35,000 CU or more, 40,000 CU or more, or 45,000 CU or more, and the upper limit is, for example, 45,000 CU or less, 40,000 CU or less, 35,000 CU or less, 30,000 CU or less, 25,000 CU or less, 20,000 CU or less, 15,000 CU or less, 10,000 CU or less, or 5,000 CU or less.

[0127] In an embodiment of the present application, the cigarette filter may have a predetermined shape and size.

[0128] For example, the filter may have a rod shape. More specifically, the cigarette filter may have a cylindrical shape.

[0129] The filter may have a length of, for example, 10 to 150 mm. Specifically, the filter length may have a lower limit of 20 mm or more, 30 mm or more, 40 mm or more, 50 mm or more, 60 mm or more, 70 mm or more, 80 mm or more, 90 mm or more, 100 mm or more, 110 mm or more, 120 mm or more, 130 mm or more, 140 mm or more, or 150 mm or more. The filter length may have an upper limit of 150 mm or less, 140 mm or less, 130 mm or less, 120 mm or less, 110 mm or less, 100 mm or less, 90 mm or less, 80 mm or less, 70 mm or less, 60 mm or less, 70 mm or less, 60 mm or less, 50 mm or less, 40 mm or less, 30 mm or less, or 20 mm or less.

[0130] In a specific example of the present application, the filter having the above length has a circular cross section, and the circumference of the circular cross section is 10 to 30 mm. For example, the circumference of the filter may have a lower limit of 15 mm or more, 20 mm or more, or 25 mm or more, and an upper limit of 25 mm or less, 20 mm or less, or 15 mm or less.

[0131] Although not particularly limited, the tow may be subjected to an opening treatment or a plasticizer treatment before being packed into the filter paper.

[0132] In one example, the cigarette filter manufactured by the above method may have a resistance to draw of 185 mmH2O or more as measured by KS H ISO 6565. Specifically, the resistance to draw of the cigarette filter may be 190 mmH2O or more, 200 mmH2O or more, 210 mmH2O or more, 220 mmH2O or more, 230 mmH2O or more, 240 mmH2O or more, 250 mmH2O or more, 260 mmH2O or more, 270 mmH2O or more, 280 mmH2O or more, 290 mmH2O or more, 300 mmH2O or more, 310 mmH2O or more. or more, 320 mmH2O or more, 330 mmH2O or more, 340 mmH2O or more, 350 mmH2O or more, 360 mmH2O or more, 370 mmH2O or more, 380 mmH2O or more, 390 mmH2O or more, 400 mmH2O or more, 410 mmH2O or more, 420 mmH2O or more, 430 mmH2O or more, 440 mmH2O or more, or 450 mmH2O or more. The upper limit of the suction resistance is, for example, 920 mmH2O or less. Specifically, the upper limit of the suction resistance is, for example, 910 mmH2O or less, 900 mmH2O or less, 890 mmH2O or less, 880 mmH2O or less, 870 mmH2O or less, 860 mmH2O or less, 850 mmH2O or less, 840 mmH2O or less, 830 mmH2O or less, 820 mmH2O or less, 810 mmH2O or less, 800 mmH2O or less, 750 mmH2O or less, 650 mmH2O or less, 600 mmH2O or less, 550 mmH2O or less, 500 mmH2O or less, 450 mmH2O or less, 400 mmH2O or less. or less, 390mmH2O or less, 380mmH2O or less, 370mmH2O or less, 360mmH2O or less, 350mmH2O or less, 340mmH2O or less, 330mmH2O or less, 320mmH2O or less, 310mmH2O or less, 300mmH2O or less, 290mmH2O or less, 280mmH2O or less, 270mmH2O or less, 260mmH2O or less, 250mmH2O or less, 240mmH2O or less, 230mmH2O or less, 220mmH2O or less, 210mmH2O or less or 200mmH2O or less.

[0133] Although not particularly limited, the resistance to draw may be measured for a filter rod having a circumference of 10 to 30 mm, or 15 to 27 mm. The circumference of a cigarette filter is determined by the number of crimps in the tow, the quality of the tow (e.g., the uniformity of the crimp shape), etc., and the resistance to draw may be determined by the fineness, cross-sectional shape, etc.

[0134] Although not particularly limited, the resistance to draw is measured for a filter rod containing a wrapper paper having a porosity of 5,000 to 15,000 CU and having a length in the range of 60 to 150 mm.

[0135] Although not particularly limited, the resistance to draw may be measured for a rod-shaped filter having a weight of 300 to 1,000 mg, 400 to 900 mg, 500 to 800 mg, or 600 to 700 mg.

[0136] As mentioned above, the present application can provide a lyocell material having a fineness within the above-mentioned range, specifically a fineness that can ensure a wide range of filter performance suitable for regular filters and (ultra) slim filters. Furthermore, a cigarette filter containing such a lyocell material can have a predetermined draw resistance.

[0137] For example, when the lyocell material is used in an (ultra) slim filter (e.g., when the circumference of the filter rod is 19 mm or less, specifically, the upper limit of the circumference is, for example, 18.5 mm or less, 18 mm or less, 17.5 mm or less, 17 mm or less, or 16.5 mm or less, and the lower limit is, for example, 15.0 mm or more, 15.5 mm or more, 16.5 mm or more, 17.0 mm or more, 17.5 mm or more, 18.0 mm or more, or 18.5 mm or more), the total fineness of the lyocell multifilaments is in the range of 15,000 to 25,000 denier. Specifically, the total fineness of the lyocell multifilaments used in the ultra-slim filter is 16,000 denier or more, 17,000 denier or more, 18,000 denier or more, 19,000 denier or more, 20,000 denier or more, 21,000 denier or more, 22,000 denier or more, 23,000 denier or more, or 24,000 denier or more, and 24,000 denier or less, 23,000 denier or less, 22,000 denier or less, 21,000 denier or less, 20,000 denier or less, 19,000 denier or less, 18,000 denier or less, 17,000 denier or less, or 16,000 denier or less. In such cases, the lyocell monofilament has a single yarn fineness of 4.5 denier or more, e.g., 5.0 denier or more, 5.5 denier or more, 6.0 denier or more, 6.5 denier or more, 7.0 denier or more, or 7.5 denier or more. Cigarette filters containing lyocell material of such fineness also have a resistance to draw of 370 mmH2O or more as measured by KS H ISO 6565. Specifically, the cigarette filter may have a resistance to draw of 380 mmH2O or more, 390 mmH2O or more, 400 mmH2O or more, 410 mmH2O or more, 420 mmH2O or more, 430 mmH2O or more, 440 mmH2O or more, 450 mmH2O or more, 460 mmH2O or more, 470 mmH2O or more, 480 mmH2O or more, 490 mmH2O or more, 500 mmH2O or more, 510 mmH2O or more, 520 mmH2O or more, 530 mmH2O or more, 540 mmH2O or more, 550 mmH2O or more, 560 mmH2O or more, 570 mmH2O or more, 580 mmH2O or more, 590 mmH2O or more, or 600 mmH2O or more.In this case, the upper limit of the suction resistance is, for example, 920 mmH2O or less, specifically 900 mmH2O or less, 850 mmH2O or less, 800 mmH2O or less, 750 mmH2O or less, 700 mmH2O or less, or 650 mmH2O or less.

[0138] In another example, the lyocell material is a regular type filter (e.g., a filter rod) having a circumference of 19 mm or more. Specifically, the lower limit of the circumference is, for example, 19.5 mm or more, 20.0 mm or more, 20.5 mm or more, 21.0 mm or more, 21.5 mm or more, 22.0 mm or more, 22.5 mm or more, 23.0 mm or more, 23.5 mm or more, 24.0 mm or more, 24.5 mm or more, 25 mm or more, 25.5 mm or more, 26.0 mm or more, or 26.5 mm or more. When the upper limit is used (e.g., 27.0 mm or less, 26.5 mm or less, 26.0 mm or less, 25.5 mm or less, 25.0 mm or less, 24.5 mm or less, 24.0 mm or less, 23.5 mm or less, 23.0 mm or less, 22.5 mm or less, 22.0 mm or less, 21.5 mm or less, 21.0 mm or less, 20.5 mm or less, 20.0 mm or less, or 19.5 mm or less), the total fineness of the lyocell multifilaments is also in the range of 25,000 to 45,000 denier. Specifically, the total fineness of the Lyocell multifilament used in regular filters is 26,000 or more, 27,000 or more, 28,000 or more, 29,000 or more, 30,000 or more, 31,000 or more, 32,000 or more, 33,000 or more, 34,000 or more, 35,000 or more, 36,000 or more, 37,000 or more, 38,000 or more, 39,000 or more, 40,000 or more, 41,000 or more, 42,000 or more, 43,000 or more or 44,000 or more, and also 44,000 or less, 43,000 or less, 42,000 or less, 41,000 or less, 40,000 or less, 39,000 or less, 38,000 or less, 37,000 or less, 36,000 or less, 35,000 or less, 34,000 or less, 33,000 or less, 32,000 or less, 31,000 or less, 30,000 or less, 29,000 or less, 28,000 or less, 27,000 or less, or 26,000 or less. In such cases, the single yarn fineness of the lyocell monofilament is 5.0 denier or less, for example, 4.5 denier or less, 4.0 denier or less, 3.5 denier or less, 3.0 denier or less, 2.5 denier or less, or 2.0 denier or less.Cigarette filters comprising Lyocell material of such fineness also have a resistance to draw of 185 mmH2O or more as measured in accordance with KS H ISO 6565. Specifically, the cigarette filters may have a resistance to draw of 190 mmH2O or more, 200 mmH2O or more, 210 mmH2O or more, 220 mmH2O or more, 230 mmH2O or more, 240 mmH2O or more, 250 mmH2O or more, 260 mmH2O or more, 270 mmH2O or more, 280 mmH2O or more, 290 mmH2O or more, 300 mmH2O or more, 310 mmH2O or more, 320 mmH2O or more, 330 mmH2O or more, 340 mmH2O or more, 350 mmH2O or more, 360 mmH2O or more, or 370 mmH2O or more. The upper limit of the suction resistance is, for example, 500 mmH2O or less, 450 mmH2O or less, or 400 mmH2O or less.

[0139] A filter having the above resistance to draw values ​​can provide uniformity in concentration of smoke and excellent filtering performance when a user smokes a cigarette.

[0140] In yet another embodiment of the present application, the present application relates to a cigarette filter, the cigarette filter including a profiled lyocell material, the lyocell material being the same as that described above.

[0141] Specifically, the modified cross-section lyocell material contained in the filter is also a crimped tow produced by crimping a lyocell multifilament. The lyocell multifilament includes a modified cross-section monofilament, the total fineness of the lyocell multifilament being 15,000 to 45,000 denier, and the monofilament constituting the lyocell multifilament having a single yarn fineness of 1.5 to 8.0 denier. The modified cross-section of the monofilament may have at least three protrusions, each of which may have a degree of deformation of 0.6 or more and a width ratio of 0.5 to 2.0. The specific values ​​for these are as described above. Similarly, the degree of deformation and width ratio may be calculated as follows:

[0142] [Equation 1] Anomaly degree=L / W

[0143] [Equation 2] Width ratio = W1 / W2

[0144] In the above Relations 1 and 2, L represents the length of the protrusion and is calculated as the distance from the center of a line connecting the two points where one protrusion meets the two protrusions directly adjacent to it to the end point of the protrusion. W represents the width of the protrusion and is calculated as the arithmetic mean of the protrusion width W1 at a point corresponding to 10% of the length L and the protrusion width W2 at a point corresponding to 90% of the length L. The details are as described above.

[0145] In one example, the lyocell material is also a crimped tow that is produced by being fed into a crimping device so that a crimp can be imparted to the lyocell material under the condition that the crimp draft ratio expressed by the following Equation 1 is satisfied:

[0146] [Formula 1] 1.01≦crimp draft ratio≦1.30

[0147] In the above formula 1, the crimp draft ratio is calculated by V1 / V0, where V0 means the moving speed of the multifilament before it is fed into the crimping device, and V1 means the passing speed of the filament gripped by the rollers in the crimping device.

[0148] In one example, the tow may have 20 to 50 crimps per inch. Specific details are as described above.

[0149] In one example, the lyocell material contained in the cigarette filter is manufactured by the above-mentioned manufacturing method of the lyocell material, specifically, by going through the above-mentioned steps of spinning, coagulation, washing, oil treatment, and crimping.

[0150] In one example, the cigarette filter further includes a wrapper, i.e., the cigarette filter includes a lyocell material and a wrapper that encases the lyocell material. The description of the wrapper has been given above, so it will be omitted here.

[0151] In one example, the cigarette filter may have a resistance to draw of 185 mmH2O or more as measured by KS H ISO 6565. Specifically, the resistance to draw of the cigarette filter may be 190 mmH2O or more, 200 mmH2O or more, 210 mmH2O or more, 220 mmH2O or more, 230 mmH2O or more, 240 mmH2O or more, 250 mmH2O or more, 260 mmH2O or more, 270 mmH2O or more, 280 mmH2O or more, 290 mmH2O or more, 300 mmH2O or more, 310 mmH2O or more. or more, 320 mmH2O or more, 330 mmH2O or more, 340 mmH2O or more, 350 mmH2O or more, 360 mmH2O or more, 370 mmH2O or more, 380 mmH2O or more, 390 mmH2O or more, 400 mmH2O or more, 410 mmH2O or more, 420 mmH2O or more, 430 mmH2O or more, 440 mmH2O or more, or 450 mmH2O or more. The upper limit of the suction resistance is, for example, 920 mmH2O or less. Specifically, the upper limit of the suction resistance is, for example, 910 mmH2O or less, 900 mmH2O or less, 890 mmH2O or less, 880 mmH2O or less, 870 mmH2O or less, 860 mmH2O or less, 850 mmH2O or less, 840 mmH2O or less, 830 mmH2O or less, 820 mmH2O or less, 810 mmH2O or less, 800 mmH2O or less, 750 mmH2O or less, 650 mmH2O or less, 600 mmH2O or less, 550 mmH2O or less, 500 mmH2O or less, 450 mmH2O or less, or 400 mmH2O or less, More specifically, it is 390mmH2O or less, 380mmH2O or less, 370mmH2O or less, 360mmH2O or less, 350mmH2O or less, 340mmH2O or less, 330mmH2O or less, 320mmH2O or less, 310mmH2O or less, 300mmH2O or less, 290mmH2O or less, 280mmH2O or less, 270mmH2O or less, 260mmH2O or less, 250mmH2O or less, 240mmH2O or less, 230mmH2O or less, 220mmH2O or less, 210mmH2O or less, or 200mmH2O or less.

[0152] Although not particularly limited, the resistance to draw may be measured for a filter rod having a circumference of 10 to 30 mm, or 15 to 27 mm. The circumference of a cigarette filter is determined by the number of crimps in the tow, the quality of the tow (e.g., the uniformity of the crimp shape), etc., and the resistance to draw may be determined by the fineness, cross-sectional shape, etc.

[0153] Although not particularly limited, the resistance to draw is measured for a filter rod containing a wrapper paper having a porosity of 5,000 to 15,000 CU and having a length in the range of 60 to 150 mm.

[0154] Although not particularly limited, the resistance to draw may be measured for a rod-shaped filter having a weight of 300 to 1,000 mg, 400 to 900 mg, 500 to 800 mg, or 600 to 700 mg.

[0155] As mentioned above, the present application can provide a lyocell material having a fineness within the above-mentioned range, specifically a fineness that can ensure a wide range of filter performance suitable for regular filters and (ultra) slim filters. Furthermore, a cigarette filter containing such a lyocell material can have a predetermined draw resistance.

[0156] For example, when the lyocell material is used in an (ultra) slim filter (e.g., when the circumference of the filter rod is 19 mm or less, specifically, the upper limit of the circumference is, for example, 18.5 mm or less, 18 mm or less, 17.5 mm or less, 17 mm or less, or 16.5 mm or less, and the lower limit is, for example, 15.0 mm or more, 15.5 mm or more, 16.5 mm or more, 17.0 mm or more, 17.5 mm or more, 18.0 mm or more, or 18.5 mm or more), the total fineness of the lyocell multifilaments is in the range of 15,000 to 25,000 denier. Specifically, the total fineness of the lyocell multifilaments used in the ultra-slim filter is 16,000 denier or more, 17,000 denier or more, 18,000 denier or more, 19,000 denier or more, 20,000 denier or more, 21,000 denier or more, 22,000 denier or more, 23,000 denier or more, or 24,000 denier or more, and 24,000 denier or less, 23,000 denier or less, 22,000 denier or less, 21,000 denier or less, 20,000 denier or less, 19,000 denier or less, 18,000 denier or less, 17,000 denier or less, or 16,000 denier or less. In such cases, the lyocell monofilament has a single yarn fineness of 4.5 denier or more, e.g., 5.0 denier or more, 5.5 denier or more, 6.0 denier or more, 6.5 denier or more, 7.0 denier or more, or 7.5 denier or more. Cigarette filters containing lyocell material of such fineness also have a resistance to draw of 370 mmH2O or more as measured by KS H ISO 6565. Specifically, the cigarette filter may have a resistance to draw of 380 mmH2O or more, 390 mmH2O or more, 400 mmH2O or more, 410 mmH2O or more, 420 mmH2O or more, 430 mmH2O or more, 440 mmH2O or more, 450 mmH2O or more, 460 mmH2O or more, 470 mmH2O or more, 480 mmH2O or more, 490 mmH2O or more, 500 mmH2O or more, 510 mmH2O or more, 520 mmH2O or more, 530 mmH2O or more, 540 mmH2O or more, 550 mmH2O or more, 560 mmH2O or more, 570 mmH2O or more, 580 mmH2O or more, 590 mmH2O or more, or 600 mmH2O or more.In this case, the upper limit of the suction resistance is, for example, 920 mmH2O or less, specifically 900 mmH2O or less, 850 mmH2O or less, 800 mmH2O or less, 750 mmH2O or less, 700 mmH2O or less, or 650 mmH2O or less.

[0157] In another example, the lyocell material is a regular type filter (e.g., a filter rod) having a circumference of 19 mm or more. Specifically, the lower limit of the circumference is, for example, 19.5 mm or more, 20.0 mm or more, 20.5 mm or more, 21.0 mm or more, 21.5 mm or more, 22.0 mm or more, 22.5 mm or more, 23.0 mm or more, 23.5 mm or more, 24.0 mm or more, 24.5 mm or more, 25 mm or more, 25.5 mm or more, 26.0 mm or more, or 26.5 mm or more. When the upper limit is used (e.g., 27.0 mm or less, 26.5 mm or less, 26.0 mm or less, 25.5 mm or less, 25.0 mm or less, 24.5 mm or less, 24.0 mm or less, 23.5 mm or less, 23.0 mm or less, 22.5 mm or less, 22.0 mm or less, 21.5 mm or less, 21.0 mm or less, 20.5 mm or less, 20.0 mm or less, or 19.5 mm or less), the total fineness of the lyocell multifilaments is also in the range of 25,000 to 45,000 denier. Specifically, the total fineness of the Lyocell multifilament used in regular filters is 26,000 or more, 27,000 or more, 28,000 or more, 29,000 or more, 30,000 or more, 31,000 or more, 32,000 or more, 33,000 or more, 34,000 or more, 35,000 or more, 36,000 or more, 37,000 or more, 38,000 or more, 39,000 or more, 40,000 or more, 41,000 or more, 42,000 or more, 43,000 or more or 44,000 or more, and also 44,000 or less, 43,000 or less, 42,000 or less, 41,000 or less, 40,000 or less, 39,000 or less, 38,000 or less, 37,000 or less, 36,000 or less, 35,000 or less, 34,000 or less, 33,000 or less, 32,000 or less, 31,000 or less, 30,000 or less, 29,000 or less, 28,000 or less, 27,000 or less, or 26,000 or less. In such cases, the single yarn fineness of the lyocell monofilament is 5.0 denier or less, for example, 4.5 denier or less, 4.0 denier or less, 3.5 denier or less, 3.0 denier or less, 2.5 denier or less, or 2.0 denier or less.Cigarette filters comprising Lyocell material of such fineness also have a resistance to draw of 185 mmH2O or more as measured in accordance with KS H ISO 6565. Specifically, the cigarette filters may have a resistance to draw of 190 mmH2O or more, 200 mmH2O or more, 210 mmH2O or more, 220 mmH2O or more, 230 mmH2O or more, 240 mmH2O or more, 250 mmH2O or more, 260 mmH2O or more, 270 mmH2O or more, 280 mmH2O or more, 290 mmH2O or more, 300 mmH2O or more, 310 mmH2O or more, 320 mmH2O or more, 330 mmH2O or more, 340 mmH2O or more, 350 mmH2O or more, 360 mmH2O or more, or 370 mmH2O or more. In this case, the upper limit of the suction resistance is, for example, 500 mmH2O or less, 450 mmH2O or less, or 400 mmH2O or less.

[0158] A filter having the above resistance to draw values ​​can provide uniformity in concentration of smoke and excellent filtering performance when a user smokes a cigarette. [Effects of the Invention]

[0159] This application provides a lyocell material for cigarette filters that can replace the widely used cellulose acetate (CA), and a cigarette filter containing the same. Specifically, this application has the effect of providing not only excellent biodegradability, but also excellent filter manufacturing processability and excellent cigarette properties (e.g., draw resistance). [Brief explanation of the drawings]

[0160] [Figure 1] 1 is a schematic diagram illustrating the cross-sectional shape, the degree of deformation and the width ratio in a predetermined range of a modified cross-section lyocell fiber according to an embodiment of the present invention. [Figure 2] 1 is an optical image of a cross section of the Lyocell material produced in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0161] The functions and effects of the present invention will be explained in more detail below through specific examples of the present invention, but these are presented as examples of the invention and do not limit the scope of the invention in any way.

[0162] Examples and Comparative Examples Lyocell materials were produced through the processes described in the following examples and comparative examples. Unless otherwise specified, the conditions were within the scope of the above description.

[0163] Example 1 A spinning dope for producing tobacco filter tow with a concentration of 11 wt% was prepared by mixing cellulose pulp with an α-cellulose content of 93.9% and a degree of polymerization (DPw) of 820 with an N-methylmorpholine-N-oxide (NMMO) / H2O solvent with a propyl gallate content of 0.01 wt%. The spinning dope was then spun from a spinning nozzle for forming a Y-shaped cross section at a spinning temperature of 110°C while adjusting the discharge rate and spinning speed so that the filament single fiber fineness was 3.45 denier.

[0164] The filament-shaped spinning dope discharged from the spinning nozzle was fed through an air gap section to a coagulation liquid (containing 75 wt% water and 25 wt% N-methylmorpholine-N-oxide (NMMO) at a temperature of about 25°C) in a coagulation tank. At this time, the cooling air in the air gap section was at a temperature of 8°C and a flow rate of 200 Nm 3 The spinning dope was subjected to primary coagulation at an air flow rate of 1 / h. The concentration of the coagulation liquid was continuously monitored using a sensor and a refractometer.

[0165] The solidified lyocell filaments were then washed with water. Specifically, the filaments were introduced into a pulling roller, and N-methylmorpholine-N-oxide (NMMO) remaining in the filaments was removed with water sprayed from a water washing device. The washed filaments were then immersed in a bath containing an oil solution with a concentration of 2 wt%.

[0166] The filament was pulled at a rate of about 2 kgf / cm by a nip roll provided at the bath discharge section. 2 The fabric was then subjected to pressure treatment and placed in a crimping device to impart wrinkles. Specifically, the crimping ratio (crimp draft ratio) was set to 1.1 times, and the steam pressure in the steam box was set to 0.5 kgf / cm. 2 The pressure of the crimping device roller is 2.5 kgf / cm 2 The pressure of the doctor blade is set to 0.5 kgf / cm 2 At this time, the crimping ratio was calculated as described above.

[0167] The produced tow was subjected to a secondary oil treatment to prevent static electricity and to impart flexibility, and immediately after the treatment, the tow was passed through a continuous drying device set at 120°C to obtain a dried tow product. The total fineness of the tow was as shown in Table 1.

[0168] Example 2 Lyocell tow for cigarette filters was produced in the same manner as in Example 1, except that the single filament fineness was adjusted to 4.6 denier. The total fineness of the tow is as shown in Table 1.

[0169] Example 3 Lyocell tow for cigarette filters was produced in the same manner as in Example 1, except that the single filament fineness was 5.55 denier. The total fineness of the tow was as shown in Table 1.

[0170] Example 4 Lyocell tow for cigarette filters was produced in the same manner as in Example 1, except that the single filament fineness was 6.98 denier. The total fineness of the tow was as shown in Table 1.

[0171] Comparative Example 1 Lyocell tow for cigarette filters was produced in the same manner as in Example 1, except that the single filament fineness was 0.55 denier. The total fineness of the tow was as shown in Table 1.

[0172] Comparative Example 2 Lyocell tow for cigarette filters was produced in the same manner as in Example 1, except that the single filament fineness was 1.12 denier. The total fineness of the tow was as shown in Table 1.

[0173] Comparative Example 3 Lyocell tow for cigarette filters was produced in the same manner as in Example 1, except that the single filament fineness was 1.43 denier. The total fineness of the tow was as shown in Table 1.

[0174] Comparative Example 4 Lyocell tow for cigarette filters was produced in the same manner as in Example 1, except that the single filament fineness was 8.85 denier. The total fineness of the tow was as shown in Table 1.

[0175] Comparative Example 5 Lyocell tow for cigarette filters was produced in the same manner as in Example 1, except that the single filament fineness was 9.94 denier. The total fineness of the tow was as shown in Table 1.

[0176] Evaluation or measurement of tows in Examples and Comparative Examples The following items were measured or evaluated for each of the Examples and Comparative Examples, and the results are shown in Table 1.

[0177] 1. Tow fineness (denier) A 2m sample of the tow to be measured is taken and left to stabilize for 24 hours in a constant temperature and humidity room at a temperature of 20°C and humidity of 65%. One end of the stabilized tow is fixed, and a 2kg weight is attached to the other end. The tow is stretched by the load and maintained in this state for 5 seconds (stabilization), after which it is cut to 90cm to obtain a sample, the weight of which is measured (total fineness). The fineness is converted to denier by multiplying the measured weight by 10,000. The single yarn fineness is calculated by dividing the total fineness by the number of filaments.

[0178] 2. Number of crimps It is measured according to the KS K 0326 standard. Specifically, 20 tow samples with undamaged crimps are taken, and pre-prepared gloss specimens (25 mm clearance) are attached to each single fiber with a celluloid 4% to 5% amyl acetate adhesive so that the attached length is extended by 25±5%, and then the adhesive is left to dry.

[0179] A crimp tester was used to apply an initial load equivalent to 1.96 / 1,000cN (=2mgf) per De to each of these samples, and the number of crimps in a 25mm interval was counted. The upper and lower limits of the number of crimps measured for 20 samples were then recorded.

[0180] 3. Measurement of protrusion irregularity A small amount of fiber bundle was sampled, rolled up with black cotton to make it thinner, and inserted into a hole in a plate that could cut the cross section. The cross section was then cut with a razor blade, taking care not to push it in. The cut cross section was then observed under magnification (200x magnification) using an optical microscope (BX51 (Olympus)), and the image was saved on a digital camera.

[0181] Using the Olympus Soft Imaging Solution program, the L (protrusion length), W (protrusion width), and perimeter of the irregular cross-section yarn were analyzed from the cross-sectional image of the fiber. At this time, L, W, and the irregularity were calculated in the same manner as defined above.

[0182] 4. Measurement of protrusion width ratio A sample was prepared in the same manner as in the above-described irregularity measurement, and the Olympus Soft Imaging Solution program was used to measure the protrusion width W1 at a point corresponding to 10% of the measurement reference line length (length L measured for irregularity) from the cross-sectional image of the fiber, and the protrusion width W2 at a point corresponding to 90% of the reference line length (length L measured for irregularity) from the center of the cross-section, and the ratio thereof was calculated.

[0183] 5. Spinnability After the spinning dope was discharged from the spinneret, the occurrence and number of thread breakages on the surface of the spinneret were recorded every hour. The number of thread breakages occurring within 24 hours was evaluated as follows:

[0184] Good: No thread breakage occurs within 24 hours Normal: Thread breaks occur 1 to 4 times per 24 hours Unacceptable: Thread breakage occurs more than 5 times in 24 hours

[0185] 6. Resistance to draw and circumference of cigarette filters Tobacco filter rods (650 mg rod weight) were manufactured using the tows manufactured in the Examples and Comparative Examples. Specifically, the lyocell tows manufactured in the Examples and Comparative Examples were wrapped with wrapping paper (6,500 CU porous paper) to manufacture cylindrical filter rods with an axial length of 120 mm and a circumference as shown in the table below.

[0186] Then, based on the KS H ISO 6565 standard, the suction resistance of each rod was measured using a suction resistance measuring instrument and a circumference measuring instrument.

[0187] [Table 1]

[0188] As can be seen in Table 1, it is confirmed that the examples according to the specific embodiments of the present application can provide tows with a predetermined shape and a predetermined range of fineness, and can provide improved resistance to attraction.

[0189] However, in the case of Comparative Example 1, the spinning conditions were inappropriate, so a tow could not be produced, and the filter performance (suction resistance) could not be confirmed. In the cases of Comparative Examples 2 to 5, in which the modified cross-sectional shape and fineness were different from those of the Examples, it was confirmed that both the regular filter (circumferential size of approximately 23 to 24.5 mm) and the (ultra) slim filter (circumferential size of approximately 16 to 19 mm) provided lower suction resistance than the Examples having the corresponding circumferential size.

Claims

1. Spinning the lyocell dope using a spinneret capable of forming a modified cross section having at least three protrusions; coagulating the spun lyocell dope to obtain a lyocell multifilament; Treating the lyocell multifilament with an oil; a crimping step of feeding the oil-treated lyocell multifilament into a crimping device so that steam and pressure are applied to the lyocell multifilament; The lyocell multifilament includes a monofilament having a modified cross section, The profiled cross section has at least three protrusions, The protrusion has a degree of deformation calculated by the following relational expression 1 of 0.6 or more, and a width ratio calculated by the following relational expression 2 of 0.5 to 2.0, A method for producing a modified cross-section lyocell material for cigarette filters, wherein the total fineness of the lyocell multifilament is 15,000 to 45,000 denier, and the single yarn fineness of the monofilament constituting the lyocell multifilament is 1.5 to 8.0 denier: [Relationship 1] Irregularity = L / W [Relationship 2] Amplitude ratio = W １ / W ２ In the above Relations 1 and 2, L means the length of the protrusion, which is calculated as the distance from the center of a line connecting two points where one protrusion meets two adjacent protrusions to the end point of the protrusion, and W means the width of the protrusion, which is the width W of the protrusion at a point corresponding to 10% of the length L. １ and the protrusion width W at the point corresponding to 90% ２ It is calculated by the arithmetic mean of

2. In the crimping step, pressure is applied to the lyocell multifilament by a roller, 2. The method for manufacturing a contoured cross-section Lyocell material for cigarette filters according to claim 1, wherein the crimping step is performed to satisfy a crimp draft ratio expressed by the following Equation 1: [Formula 1] 1.01≦crimp draft ratio≦1.30 However, in the above formula 1, the crimp draft ratio is V １ / V ０ is calculated by V ０ means the moving speed of the oil-treated multifilament before it is fed into the crimping device, and V １ means the passing speed of the filament gripped by the rollers in the crimping device.

3. 2. The method of claim 1, wherein the method provides a tow having 20 to 50 crimps per inch.

4. 2. The method for producing a modified cross-section lyocell material for cigarette filters according to claim 1, wherein the total fineness of the lyocell multifilaments is 15,000 to 25,000 denier.

5. 2. The method for producing a modified cross-section lyocell material for cigarette filters according to claim 1, wherein the total fineness of the lyocell multifilaments is 25,000 to 45,000 denier.

6. It is a crimped tow made by crimping lyocell multifilament. The total fineness of the lyocell multifilament is 15,000 to 45,000 denier, The monofilament constituting the lyocell multifilament has a single yarn fineness of 1.5 to 8.0 denier; The lyocell multifilament includes a monofilament having a modified cross section, The profiled cross section has at least three protrusions, The protrusions have a degree of deformation of 0.6 or more calculated by the following relational expression 1, and a width ratio of 0.5 to 2.0 calculated by the following relational expression 2, [Relationship 1] Irregularity = L / W [Relationship 2] Amplitude ratio = W １ / W ２ In the relations 1 and 2, L means the length of the protrusion, which is calculated as the distance from the center of the line connecting the two points where one protrusion meets the two protrusions directly adjacent to it to the end point of the protrusion, and W means the width of the protrusion, which is the width W of the protrusion at a point corresponding to 10% of the length L. １ and the protrusion width W at the point corresponding to 90% ２ It is calculated by the arithmetic mean of

7. 7. The modified cross-section Lyocell material for cigarette filters according to claim 6, which is produced by being fed into a crimping device so that a crimp can be imparted thereto under a condition that satisfies the crimp draft ratio expressed by the following mathematical formula 1: [Formula 1] 1.01≦crimp draft ratio≦1.30 However, in the above formula 1, the crimp draft ratio is V １ / V ０ is calculated by V ０ means the moving speed of the multifilament before it is fed into the crimping device, and V １ means the passing speed of the filament gripped by the rollers in the crimping device.

8. 7. The modified cross-section lyocell material for cigarette filters according to claim 6, having 20 to 50 crimps per inch.

9. 7. The modified cross-section lyocell material for cigarette filters according to claim 6, wherein the total fineness of the lyocell multifilaments is 15,000 to 25,000 denier.

10. 7. The modified cross-section lyocell material for cigarette filters according to claim 6, wherein the total fineness of the lyocell multifilaments is 25,000 to 45,000 denier.

11. Spinning the lyocell dope using a spinneret capable of forming a modified cross section having at least three protrusions; coagulating the spun lyocell dope to obtain a lyocell multifilament; Treating the lyocell multifilament with an oil; A crimping step of feeding the oil-treated lyocell multifilament into a crimping device so that steam and pressure are applied to the lyocell multifilament; and manufacturing a filter using the crimped tow; The lyocell multifilament includes a monofilament having a modified cross section, The profiled cross section has at least three protrusions, The protrusion has a degree of deformation calculated by the following relational expression 1 of 0.6 or more, and a width ratio calculated by the following relational expression 2 of 0.5 to 2.0, A method for producing a cigarette filter containing a modified cross-section lyocell material, wherein the total fineness of the lyocell multifilament is 15,000 to 45,000 denier, and the single yarn fineness of the monofilament constituting the lyocell multifilament is 1.5 to 8.0 denier: [Relationship 1] Irregularity = L / W [Relationship 2] Amplitude ratio = W １ / W ２ In the relations 1 and 2, L means the length of the protrusion, which is calculated as the distance from the center of the line connecting the two points where one protrusion meets the two protrusions directly adjacent to it to the end point of the protrusion, and W means the width of the protrusion, which is the width W of the protrusion at a point corresponding to 10% of the length L. １ and the protrusion width W at the point corresponding to 90% ２ It is calculated by the arithmetic mean of

12. In the crimping step, pressure is applied to the lyocell multifilament by a roller, The method for manufacturing a cigarette filter comprising a contoured cross-section lyocell material according to claim 11, wherein the crimping step is performed to satisfy a crimp draft ratio expressed in the following equation 1: [Formula 1] 1.01≦crimp draft ratio≦1.30 However, in the above formula 1, the crimp draft ratio is V １ / V ０ is calculated by V ０ means the moving speed of the oil-treated multifilament before it is fed into the crimping device, and V １ means the passing speed of the filament gripped by the rollers in the crimping device.

13. 12. The method for producing a cigarette filter comprising a profiled cross-section lyocell material according to claim 11, wherein the tow has 20 to 50 crimps per inch.

14. The total fineness of the lyocell multifilament is 15,000 to 25,000 denier, The resistance to suction measured by KS H ISO 6565 is 370 mmH ２ 12. A method for producing a cigarette filter according to claim 11, which provides a cigarette filter having a resistance to draw of 0 or more, wherein the resistance to draw is measured on a filter having a circumference of 19 mm or less.

15. The total fineness of the lyocell multifilament is 25,000 to 45,000 denier, The resistance to suction measured by KS H ISO 6565 is 185 mmH ２ 12. A method for producing a cigarette filter according to claim 11, which provides a cigarette filter having a resistance to draw of 0 or more, wherein the resistance to draw is measured on a filter having a circumference of 19 mm or more.

16. A cigarette filter comprising a modified cross-section lyocell material, The modified cross-section lyocell material is a crimped tow manufactured by crimping a lyocell multifilament, The total fineness of the lyocell multifilament is 15,000 to 45,000 denier, The monofilament constituting the lyocell multifilament has a single yarn fineness of 1.5 to 8.0 denier; The lyocell multifilament includes a monofilament having a modified cross section, The profiled cross section has at least three protrusions, The protrusions have a degree of deformation of 0.6 or more calculated by the following relational expression 1, and a width ratio of 0.5 to 2.0 calculated by the following relational expression 2. [Relationship 1] Irregularity = L / W [Relationship 2] Amplitude ratio = W １ / W ２ In the relations 1 and 2, L means the length of the protrusion, and is calculated as the distance from the center of the line connecting the two points where one protrusion meets the two protrusions directly adjacent to it to the end point of the protrusion. And W means the width of the protrusion, and is the width W of the protrusion at a point corresponding to 10% of the length L. １ and the protrusion width W at the point corresponding to 90% ２ It is calculated by the arithmetic mean of

17. The cigarette filter comprising the contoured cross-section Lyocell material according to claim 16, wherein the Lyocell material is fed into a crimping device so that the crimp can be given under the condition of satisfying the crimp draft ratio expressed by the following mathematical formula 1: [Formula 1] 1.01≦crimp draft ratio≦1.30 However, in the above formula 1, the crimp draft ratio is V １ / V ０ is calculated by V ０ means the moving speed of the multifilament before it is fed into the crimping device, and V １ means the passing speed of the filament gripped by the rollers in the crimping device.

18. 17. A cigarette filter comprising the profiled cross-section lyocell material of claim 16, wherein the crimped tow has 20 to 50 crimps per inch.

19. The total fineness of the lyocell multifilament is 15,000 to 25,000 denier, The cigarette filter has a resistance to draw of 370 mmH as measured by KS H ISO 6565. ２ 17. A cigarette filter according to claim 16, wherein the resistance to draw is 0 or greater, provided that the resistance to draw is measured on a filter having a circumference of 19 mm or less.

20. The total fineness of the lyocell multifilament is 25,000 to 45,000 denier, The cigarette filter has a resistance to draw of 185 mmH as measured by KS H ISO 6565. ２ 17. The cigarette filter of claim 16, wherein the resistance to draw is 0 or greater, where the resistance to draw is measured when a filter rod having a circumference of 19 mm or greater is produced.

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