Lyocell material, smoking article, and manufacturing methods therefor

Abstract

The present invention relates to a lyocell material, a smoking article comprising same, and a method for preparing the lyocell material, the lyocell material being prepared from a dope solution containing cellulose pulp and N-methylmorpholine-N-oxide (NMMO), wherein the cellulose pulp has a CED viscosity of 4.0 to 11.0, a hemicellulose content of less than 5 wt%, an Fe content of 1 ppm to less than 30 ppm by weight, and an Si content of 1 ppm to less than 100 ppm by weight.

Description

Lyocell materials, smoking articles and methods for manufacturing them

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0178048, filed December 8, 2023, and Korean Patent Application No. 10-2024-0178343, filed December 4, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a lyocell material having excellent radiation processability, appearance, and cigarette filter cuttability, and having monofilament strength suitable for application to a filter for a smoking article, a smoking article including the same, and a method for producing the lyocell material.

[0003] Until now, cellulose acetate fibers have been primarily used as cigarette filter materials. While cellulose acetate is known to be biodegradable, cellulose acetate smoking filter materials 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. Cellulose acetate is a synthetic plastic that decomposes into microplastics through physical and photochemical reactions when exposed to the environment. Microplastics are known to be harmful and ecologically disruptive substances.

[0004] Accordingly, research is being conducted in various fields to develop biodegradable, chemically unmodified materials for smoking articles to replace cellulose acetate. Recently, research is being conducted on lyocell-based filters for smoking articles. However, there is still a need for lyocell materials suitable for the continuous manufacturing process of smoking article filters.

[0005] The present invention provides a lyocell material having excellent radiation processability, appearance, and cigarette filter cuttability, and having monofilament strength suitable for application to a filter for a smoking article, a smoking article including the same, and a method for producing the lyocell material.

[0006] According to one aspect, a lyocell material manufactured from a dope solution containing cellulose pulp and N-methylmorpholine-N-oxide (NMMO),

[0007] The cellulose pulp has a CED viscosity of 4.0 to 11.0, a hemicellulose content of less than 5 wt%, an Fe content of 1 ppm or more to less than 30 ppm by weight, and a Si content of 1 ppm or more to less than 100 ppm by weight, and a lyocell material is provided.

[0008] The above lyocell material may include one or more lyocell multifilaments.

[0009] The above lyocell multifilament may comprise one or more lyocell monofilaments.

[0010] According to another aspect, a smoking article comprising the above lyocell material is provided.

[0011] According to another aspect, the step of spinning a dope solution containing cellulose pulp and N-methylmorpholine-N-oxide (NMMO) through a detention,

[0012] A step of solidifying the radiated dope solution to obtain lyocell multifilament;

[0013] A step of washing the above lyocell multifilament and then treating it with an emulsion, and

[0014] A step of crimping a multifilament treated with a lubricant to obtain a crimp tow,

[0015] A method for producing a lyocell material is provided, wherein the cellulose pulp has a CED viscosity of 4.0 to 11.0, a hemicellulose content of less than 5 wt%, an Fe content of 1 ppm or more to less than 30 ppm by weight, and an Si content of 1 ppm or more to less than 100 ppm by weight.

[0016] According to one aspect, a lyocell material uses pulp as a raw material, wherein the pulp has a CED viscosity of 4.0 to 11.0, a hemicellulose content of less than 5 wt%, an Fe content of 1 ppm or more to less than 30 ppm by weight, and an Si content of 1 ppm or more to less than 100 ppm by weight, thereby satisfying the monofilament strength range applicable as a filter for smoking articles, and also enabling the manufacture of a cigarette filter having good cutability.

[0017] The present inventive concept described below is susceptible to various modifications and embodiments, and specific embodiments are described in detail in the detailed description. However, this is not intended to limit the present inventive concept to specific embodiments, but should be understood to encompass all modifications, equivalents, or alternatives within the technical scope of the present inventive concept.

[0018] The terms used below are used only to describe specific embodiments and are not intended to limit the present creative ideas.

[0019] Singular expressions include plural expressions unless the context clearly indicates otherwise. Hereinafter, terms such as "comprises" or "have" should be understood to indicate the presence of a feature, number, step, operation, component, part, ingredient, material, or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, ingredients, materials, or combinations thereof.

[0020] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Furthermore, it will be understood that terms defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning within the context of the relevant art and the present disclosure, and not in an idealized or overly formal sense.

[0021] In this specification, "smoking article" may refer to an article capable of generating an aerosol, such as a cigarette or cigar. In this regard, the smoking article may include an aerosol-generating material or an aerosol-forming substrate. Furthermore, the smoking article may include a solid material based on tobacco raw materials, such as tobacco leaf, tobacco ash, or reconstituted tobacco. Additionally, the smoking material may include volatile compounds.

[0022] Unless otherwise specifically defined herein, if the characteristics of lyocell materials, filters for smoking articles, and related components or compositions thereof are affected by temperature, the temperature at which the characteristics are confirmed or measured may be room temperature. In this case, room temperature refers to a temperature in a non-thermally or non-heated state, and may be, for example, a temperature of 10 to 35°C, specifically 15 to 35°C, 20 to 30°C, or about 25°C.

[0023] In this specification, the term "different" may mean qualitatively different from each other. For example, "A and B are different" may mean that the amount of A and the amount of B are the same, but A and B are qualitatively distinct, or that A and B are quantitatively different and also qualitatively distinct. The term "qualitative" may mean non-quantitative characteristics. For example, differences in color, shape, texture, structure, and composition may fall under "qualitative" differences.

[0024] As used herein, the term "crimp" may refer to a wavy, curled, or undulating configuration imparted to a material, such as a fiber, filament, multifilament, and / or yarn, either inherently or through mechanical, thermal, and / or chemical processes. Crimp may be characterized by a periodic deviation from a straight axis along the length of the material, fiber, filament, multifilament, and / or yarn. One crimp in a material, fiber, filament, multifilament, and / or yarn may be defined as one repeating unit of said periodic deviation. The presence of crimp affects properties of the material and fabrics made from the material, such as elasticity, bulk, resilience, and texture.

[0025] In this specification, the term "degree of polymerization" (DP) may refer to the number of monomer units and / or repeating units in a macromolecule or polymer or oligomer molecule. Degree of polymerization (DP) is M n / M0 can be expressed as, where M n is the number average molecular weight of the macromolecule or polymer or oligomer molecule, and M0 is the molecular weight of the monomer or repeating unit.

[0026] Hereinafter, lyocell materials, smoking articles including the same, and methods for manufacturing the lyocell materials according to exemplary embodiments are described in more detail.

[0027] [Lyocell material]

[0028] The term "lyocell material" herein refers to a monofilament material or a material of a collection of monofilaments (multifilament) that can be obtained by spinning, coagulating, and drying a dope solution in which cellulose pulp is dissolved in an N-methylmorpholine-N-oxide (NMMO) solution. It will be understood in the art that the term "lyocell material" herein is distinct from "cellulose acetate material."

[0029] According to one aspect, a lyocell material is manufactured from a dope solution containing cellulose pulp and N-methylmorpholine-N-oxide (NMMO), wherein the cellulose pulp has a CED viscosity of 4.0 to 11.0, a hemicellulose content of less than 5 wt% based on the total weight of the cellulose pulp, an Fe content of 1 ppm or more to less than 30 ppm by weight, and an Si content of 1 ppm or more to less than 100 ppm by weight.

[0030] CED viscosity was measured according to TAPPI Standard T230 om-94.

[0031] Hemicellulose content was measured according to KS M 7044:2016.

[0032] Inorganic components in pulp, such as Fe and Si content, were measured using ICP-OES (PerkinElmer Avio-550).

[0033] The above cellulose pulp may have an alpha-cellulose content of 85 to 97 wt% relative to 100 wt% of the total cellulose contained in the cellulose pulp and / or relative to 100 wt% of the total cellulose pulp.

[0034] The above cellulose pulp may have a hemicellulose content of 1% to less than 5% by weight relative to 100% by weight of the total cellulose contained in the cellulose pulp and / or relative to 100% by weight of the total cellulose pulp.

[0035] The above lyocell material can improve the processability and workability of the final lyocell material by using cellulose pulp having a specific 0.5% CED viscosity, hemicellulose content and inorganic content as a raw material.

[0036] The spinning processability can be improved by adjusting the CED viscosity of the raw cellulose pulp of lyocell material to 4.0 to 11.0. However, if the CED viscosity is less than 4.0, yarn breakage occurs continuously during spindle discharge and the spinning processability deteriorates, making it difficult to produce continuous filaments. If the viscosity exceeds 11.0, excessive pressure may be required for extrusion of the spinning dope, or clogging of the discharge port may occur.

[0037] By adjusting the hemicellulose content of the raw cellulose pulp of lyocell material to less than 5 wt%, it is possible to produce stable, continuous lyocell filaments. If the hemicellulose content exceeds 5 wt%, not only is contamination of the spinneret caused by hemicellulose eluted from the solvent NMMO a problem, but the increased hemicellulose content in the lyocell material causes a decrease in filament strength, making it difficult to apply it as a filter for smoking articles. Furthermore, from the perspective of the NMMO recovery process, the removal of eluted hemicellulose from NMMO is essential, which adds cost and burden to the NMMO recovery / regeneration system.

[0038] By controlling the Fe content of the raw cellulose pulp of the lyocell material to less than 30 ppm by weight, the decomposition reaction of the pulp by NMMO is accelerated, and the discoloration of the filament due to the discoloration of the NMMO and the reduction in the strength of the filament can be prevented. When the Fe content of the cellulose pulp is 30 ppm or more by weight, the strength of the filament is reduced, and when it is composed of a cigarette filter, the cutability is poor, making it difficult to apply it in the filter manufacturing process.

[0039] By controlling the Si content of the raw cellulose pulp of the lyocell material to less than 100 ppm by weight, discoloration of the filament and reduction in filament strength due to discoloration of NMMO can be prevented. If the Si content of the cellulose pulp is 100 ppm or more by weight, the filament strength is reduced, and when composed into a cigarette filter, the cutability is poor, making it difficult to apply in the filter manufacturing process.

[0040] Conventionally manufactured lyocell staple fibers generally use pulp having a hemicellulose content of 5 wt% or more in manufacturing chopped filament fibers, so the filament strength is not high. However, the lyocell material according to one embodiment of the present invention achieves a monofilament strength that can be used in cigarette filters by using less than 5 wt% of hemicellulose. On the other hand, lowering the hemicellulose content alone could not satisfy the cuttability of the filament required for cigarette filters. The inventor of the present invention confirmed that when the content of Fe and the content of Si, which are trace amounts of inorganic substances present in the pulp, are adjusted, the decrease in the strength of the filament is suppressed, so that the cuttability can be improved in the process of manufacturing the cigarette filter, and the lyocell material of the present invention was completed based on this knowledge.

[0041] In addition, in the case of cigarette filters, white is preferred to provide aesthetic appeal to smokers, and the conventional manufacturing process of lyocell material was designed to pass through a whitening process of the filament, but the inventor of the present invention confirmed that it is possible to manufacture the filter with the appearance (i.e., color) required for cigarette filters by suppressing discoloration by NMMO by controlling the Fe and Si contents in the pulp, and from this knowledge, the lyocell material of the present invention was completed.

[0042] Without being bound by theory, lyocell material can have sufficient appearance and monofilament strength for application to cigarette filters while preventing filament strength degradation by using pulp having specific CED viscosity, hemicellulose content, Fe and Si contents as raw cellulose pulp, and can also have the cutability required in the cigarette filter manufacturing process.

[0043] According to one embodiment, the cellulose pulp may have a hemicellulose content of 4 wt% or less based on the total weight of the cellulose pulp. For example, the cellulose pulp may have a hemicellulose content of 3.9 wt% or less, 3.8 wt% or less, or 3.7 wt% or less. The cellulose pulp may be hemicellulose-free, but in reality, refining the pulp so that it does not contain hemicellulose requires a complex process and a high cost, and is therefore not preferred.

[0044] According to one embodiment, the cellulose pulp may contain various inorganic substances during the extraction process. For example, the cellulose pulp may contain inorganic substances such as iron, copper, and silicon. Previous research on lyocell has confirmed the strength of lyocell multifilaments according to the hemicellulose content in cellulose pulp, but no research has been conducted on controlling the inorganic substance content.

[0045] According to one embodiment, the inorganic content in the cellulose pulp can be controlled by, but is not necessarily limited to, contacting the pulp with a diluted acid solution, such as sulfurous acid, hydrochloric acid or sulfuric acid, to form and remove inorganic salts.

[0046] According to one embodiment, the cellulose pulp may contain 1 to 20 ppm of Fe by weight, based on the total weight of the cellulose pulp. For example, the cellulose pulp may contain 1 to 19 ppm, 1 to 18 ppm, 1 to 17 ppm, 1 to 16 ppm, 1 to 15 ppm, 1 to 14 ppm, 1 to 13 ppm, 1 to 12 ppm, 1 to 11 ppm, 1 to 10 ppm, 1 to 9 ppm, 1 to 8 ppm, 1 to 7 ppm, 1 to 6 ppm, 1 to 5 ppm, 1 to 4 ppm, 1 to 3 ppm, or 1 to 2 ppm of Fe by weight.

[0047] According to one embodiment, the cellulose pulp may contain Si in an amount of 1 to 100 ppm by weight, based on the total weight of the cellulose pulp. For example, the cellulose pulp may contain Si in an amount of 1 to 90 ppm, 1 to 80 ppm, 1 to 70 ppm, 1 to 60 ppm, 1 to 50 ppm, 1 to 40 ppm, 1 to 30 ppm, 1 to 20 ppm, or 1 to 10 ppm by weight, but is not limited thereto, and may be a range formed by a combination of any lower limit and any upper limit among the numerical ranges.

[0048] According to one embodiment, the cellulose pulp may contain 1 to 10 ppm of Fe by weight and 1 to 90 ppm of Si by weight, based on the total weight of the cellulose pulp. For example, the cellulose pulp may contain 1 to less than 5 ppm of Fe by weight and 5 to 80 ppm of Si by weight.

[0049] According to one embodiment, the cellulose pulp may have a degree of polymerization of 600 to 1700. In some embodiments, the degree of polymerization refers to the number of repeating units and / or monomer units of cellulose and / or hemicellulose contained in the cellulose pulp.

[0050] According to one embodiment, the lyocell material comprises one or more lyocell monofilaments, wherein the monofilaments can have a strength of 0.265 N / tex to 0.706 N / tex (3 g / d to 8 g / d). For example, the monofilament may have a tenacity of 0.274 N / tex to 0.698 N / tex (3.1 g / d to 7.9 g / d), 0.283 N / tex to 0.689 N / tex (3.2 g / d to 7.8 g / d), 0.291 N / tex to 0.680 N / tex (3.3 g / d to 7.7 g / d), 0.300 N / tex to 0.671 N / tex (3.4 g / d to 7.6 g / d), or 0.309 N / tex to 0.662 N / tex (3.5 g / d to 7.5 g / d). As used herein, the term "tenacity" means textile strength and / or tenacity.

[0051] Strength can be measured as follows: Multifilament specimens are pre-dried at 110°C for 2 hours, then left to reach moisture equilibrium for more than 24 hours under the standard conditions of KS K 0901. Then, monofilament specimens are separated from the multifilament specimens. The tensile strength of the separated monofilament specimens is measured using a low-speed extension tensile tester (Instron) at a tensile speed of 60 mm / min.

[0052] When the above lyocell material has a monofilament strength within the above range, it is easy to process it into a filter for a cigarette filter. When the strength of the monofilament is less than 0.265 N / tex (3 g / d), the cigarette filter manufactured from it easily collapses when a smoker bites it, making it difficult to function as a filter. When the strength exceeds 0.706 N / tex (8 g / d), it is difficult to cut the filter during the cigarette filter manufacturing process due to the high tensile strength, which causes a problem of poor cut cross-section.

[0053] According to one embodiment, the lyocell material may be crimped. As will be described in more detail in the lyocell material manufacturing process described below, the lyocell material can be crimped through the crimping process, thereby achieving the required suction resistance and filtration performance when used as a material for cigarette filters. Furthermore, the improved openability during the cigarette filter manufacturing process enables the continuous production of cigarette filters.

[0054] In one embodiment, the lyocell material can have crimps of from 25.4 to 127 per centimeter (10 to 50 per inch).

[0055] According to one embodiment, the lyocell material may be lyocell tow. Lyocell tow refers to a product in which lyocell multifilaments are assembled in the form of a band, and is a material used in the cigarette filter manufacturing process.

[0056] According to one embodiment, the lyocell tow may have a non-shaped cross-section. The term "non-shaped cross-section" may refer to a cross-sectional shape that deviates from the standard circular shape. For example, the cross-sectional shape may have a Y-shaped cross-section, a rectangular cross-section, a star-shaped cross-section, a leaf-shaped cross-section, a hexagonal cross-section, a polygonal cross-section, etc. The lyocell tow may have a Y-shaped cross-section for use in cigarette filters.

[0057] According to one embodiment, the lyocell tow can have a total fineness of 1.67 to 6.11 g / m (15,000 to 55,000 denier).

[0058] According to one embodiment, the lyocell tow can be used for manufacturing a smoking article filter.

[0059] [Method for manufacturing lyocell material]

[0060] A method for manufacturing a lyocell material according to one aspect includes the steps of spinning a dope solution containing cellulose pulp and N-methylmorpholine-N-oxide (NMMO) through a spinneret, solidifying the spun dope solution to obtain lyocell multifilament, washing the lyocell multifilament with water and then treating it with an emulsion, and crimping the emulsion-treated multifilament to obtain a crimped tow, wherein the cellulose pulp has a CED viscosity of 4.0 to 11.0 or less, a hemicellulose content of less than 5 wt% based on the total weight of the cellulose pulp, an Fe content of 1 ppm or more to less than 30 ppm by weight, and an Si content of 1 ppm or more to less than 100 ppm by weight. The CED viscosity was measured according to TAPPI Standard T230 om-94.

[0061] A method for manufacturing a lyocell material according to one embodiment is described in more detail below.

[0062] <(a) Lyocell dope radiation stage>

[0063] The dope for lyocell spinning can be prepared by dissolving cellulose pulp having the aforementioned CED viscosity of 4.0 to 11.0 or less, a hemicellulose content of less than 5 wt% based on the total weight of the cellulose pulp, an Fe content of 1 ppm or more to less than 30 ppm by weight, and an Si content of 1 ppm or more to less than 100 ppm by weight in an N-methylmorpholine-N-oxide (NMMO) solution.

[0064] According to one embodiment, the content of cellulose pulp in the spinning dope may be 5 to 15 wt% based on 100 wt% of the total weight of the dope. If the content of cellulose pulp is too low, it is difficult to implement the characteristics of lyocell fiber, and if the content exceeds the above range, it is difficult to dissolve in a solvent. Considering this, the content of cellulose pulp in the spinning dope may be 6 wt% or more, 7 wt% or more, 8 wt% or more, 9 wt% or more, or 10 wt% or more, and the upper limit thereof may be, 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.

[0065] According to one embodiment, the radiation dope may include an aqueous solution of N-methylmorpholine-N-oxide (NMMO). The aqueous solution may include, for example, a weight ratio of 80 to 95% of N-methylmorpholine-N-oxide and a weight ratio of 5 to 20% of water, taking into account the degree of dissolution of cellulose and the process temperature.

[0066] According to one embodiment, the cellulose or cellulose pulp may have an alpha-cellulose content of 85 to 97 wt% relative to 100 wt% of total cellulose.

[0067] According to one embodiment, the cellulose or cellulose pulp may have a hemicellulose content of 1% to less than 5% by weight relative to 100% by weight of total cellulose. By controlling the hemicellulose content within the above range, stable physical properties (e.g., mechanical properties such as strength or elongation) and processability of the lyocell material can be more easily secured.

[0068] In the above-mentioned radiation step, the shape of the detention device for discharging the radiation dope is not particularly limited. For example, a donut-shaped radiation detention device may be used.

[0069] The nozzle temperature of the above-described spinning device can be appropriately selected by those skilled in the art, taking into account the concentration of the spinning dope and the desired properties of the filament. For example, the spinning temperature can be, for example, from 100°C to 120°C or less, or from 100°C to 110°C or less.

[0070] The radiation dope discharged through the radiation detention can go through the coagulation step described below.

[0071] <(b) Coagulation and multifilament production step>

[0072] The radiated dope discharged from the radiation detention device is coagulated, and a lyocell multifilament can be obtained.

[0073] The above coagulation may be carried out in a manner in which the radiated dope comes into contact with air and / or a coagulating liquid.

[0074] According to one embodiment, the solidification may include a first solidification step of supplying cooling air to the radiated dope; and a second solidification step of introducing the first-solidified radiated dope into a solidification solution to solidify it.

[0075] The primary coagulation step can be performed in the space between the spinneret and the coagulation tank (air gap section). In the air gap section, cooling air can be supplied from the inside to the outside of the spinneret, but is not limited thereto. Cooling air can also be supplied from the outside to the inside or in both directions simultaneously. Furthermore, those skilled in the art can appropriately refer to known air quenching methods to perform the primary coagulation step.

[0076] According to one embodiment, the upper temperature limit of the cooling air used for the primary solidification may be, for example, 15°C or lower. For example, the cooling air may be air having a temperature of 14°C or lower, 13°C or lower, 12°C or lower, 11°C or lower, or 10°C or lower. If the temperature exceeds the temperature, the solidification of the radiation dope by the air is not sufficient, and the radiation-related processability is poor.

[0077] The lower limit of the cooling air temperature may be determined by considering factors such as the spinning processability and / or the cross-sectional uniformity of the filament. For example, if the temperature of the cooling air is below 4°C, the surface of the spinneret cools, the surface of the filament becomes uneven, and the spinning processability also deteriorates. Considering this, the cooling air temperature may be 5°C or higher, 6°C or higher, 7°C or higher, 8°C or higher, or 9°C or higher.

[0078] The degree to which the cooling air is supplied can be controlled taking into account sufficient coagulation, spinning processability, and the influence on the physical properties of the filament. For example, 70 to 400 Nm 3 / h can be supplied to the radiation dope discharged at an air volume of 100 Nm 3 / h or more, 150 Nm 3 / h or more, 200 Nm 3 / h or more or 250 Nm 3 / h or more, and the upper limit of the airflow is, for example, 350 Nm 3 / h or less, 300 Nm 3 / h or less, 250 Nm 3 / h or less, 200 Nm 3 / h or less or 150 Nm 3 / h can be less than or equal to.

[0079] After the primary coagulation as described above, the cooled spinning dope can be supplied to a coagulation tank or bath containing a coagulating solution (secondary coagulation). For proper coagulation, the temperature of the coagulating solution can be, for example, 30°C or lower or 25°C or lower. Furthermore, the temperature of the coagulating solution can be 10°C or higher, 15°C or higher, or 20°C or higher. Maintaining the temperature above allows for an appropriate coagulation rate to be maintained.

[0080] The type of coagulant for the secondary coagulation described above is not particularly limited. For example, the coagulant may contain one or more of water and N-methylmorpholine-N-oxide (NMMO).

[0081] According to one embodiment, when the coagulant contains water and NMMO, the water content in the coagulant may be 60 to 90 wt% and the NMMO content may be 10 to 40 wt%, based on the total weight of the coagulant. Alternatively, the coagulant may contain 70 to 80 wt% of water and 20 to 30 wt% of NMMO. The concentration of the coagulant may be controlled to be maintained during the manufacturing process using a concentration control device.

[0082] <(c) Washing stage>

[0083] The multifilament obtained by coagulating the spin dope can be washed. The washing process can control the amount of NMMO and / or other impurities remaining in the filament to a desired level.

[0084] The method of washing is not particularly limited. For example, washing can be accomplished by introducing each coagulated lyocell multifilament into a washing tank using a traction roller. Alternatively, washing can be accomplished by spraying the washing solution onto the lyocell multifilament as it moves to the next stage via a traction roller.

[0085] The components of the washing liquid are not particularly limited. For example, the washing liquid may contain water and may also contain known additives.

[0086] In addition, considering reuse after washing, etc., the washing liquid may be used at a temperature adjusted to 100°C or lower.

[0087] <(d) Milk processing stage>

[0088] After washing the multifilament, an emulsion treatment step may be performed to apply an emulsion to the surface. By applying the emulsion to the multifilament, friction applied to the filament during the subsequent crimping step is reduced, thereby facilitating the formation of a crimp. The emulsion treatment step may be performed once or, if necessary, twice or more times. If the emulsion treatment is performed twice or more, the process may be referred to as a first emulsion treatment and a second emulsion treatment, depending on the order of application.

[0089] Although not particularly limited, the emulsion treatment may be carried out by immersing each lyocell multifilament in a bath filled with emulsion so that each lyocell multifilament is completely submerged in the emulsion. Alternatively, the emulsion may be treated by spraying the emulsion liquid while being moved to the next stage by a traction roller.

[0090] After the emulsion treatment as described above, in order to ensure that the amount of emulsion applied to each lyocell multifilament is constant, an additional process may be performed in which a roll, etc., positioned before and / or after the emulsion treatment step squeezes out the emulsion from the surface of the lyocell multifilament.

[0091] After the above-described milk treatment, drying can be performed before the crimping step.

[0092] <(e) Crimp application step>

[0093] The crimping step is a step in which pressure is applied to the emulsion-treated multifilament through steam and / or a press roller to obtain a crimped multifilament, preferably a crimped tow. The crimping step may be referred to as a crimping step.

[0094] Crimping imparts waves to each lyocell multifilament, giving the fibers bulky properties. Crimping can be performed using any known crimping device, such as one comprising a stuffer box and / or a steam box.

[0095] According to one embodiment, the crimping step may be performed by first supplying steam to each lyocell multifilament to preheat and swell each lyocell multifilament, and then pressing each lyocell multifilament with a press roller to form wrinkles in the lyocell multifilament. At this time, a steam box may be used for supplying steam, and the steam box may be located at the front end of the crimping device. The supply of steam in the crimping step may be omitted as needed.

[0096] According to one embodiment, the crimping step can be performed in such a way that the pressurization of the lyocell multifilament by the press roller and the application of steam are performed simultaneously.

[0097] According to one embodiment, the crimping step may be performed by pressing each lyocell multifilament with a press roller to form wrinkles in each lyocell multifilament. Furthermore, steam may not be supplied prior to pressurization, steam may not be supplied simultaneously with pressurization, or steam may not be supplied both prior to pressurization and simultaneously with pressurization.

[0098] According to one embodiment, the crimping step may include applying a doctor blade that applies a predetermined pressure to each lyocell multifilament. The doctor blade controls the residence time of the filaments fed into the crimper stuffer box, thereby contributing to the control of the number of crimps. Such a doctor blade may be positioned, for example, in the path of each lyocell multifilament that is discharged from the roller pressure point after being pressed by the roller described above.

[0099] According to one embodiment, the crimping step may be performed at a temperature ranging from 120 to 250°C. If the temperature is too low, the shape stabilization effect of the crimp is not good, and if the temperature is too high, the concentration of the oil content in the stuffer box may increase, making it difficult to form the crimp.

[0100] The lyocell material according to the present invention can be obtained by the method for producing a lyocell material as described above.

[0101] The lyocell material according to the present invention may be a material obtainable by the method for producing a lyocell material as described above.

[0102] [Smoking items]

[0103] The aforementioned lyocell material may be incorporated into a smoking article. The smoking article may be an aerosol-generating article. The aerosol-generating article may include an aerosol-generating material or an aerosol-forming substrate.

[0104] For example, the lyocell material may be incorporated into a combustible cigarette or a heated cigarette, and the heated cigarette may be used in conjunction with an aerosol generating device.

[0105] For example, when used as a heated smoking article, the smoking article may be separately inserted into an aerosol generating device. Here, the aerosol generating device may include a receiving groove in which the aerosol generating article can be received, and in addition, may include a heater for heating the aerosol generating article so as to generate an aerosol, a control unit for controlling the overall operation of the aerosol generating device, a battery for providing power used for the operation of the aerosol generating device, and a detector for recognizing that the aerosol generating article has been inserted into the aerosol generating device.

[0106] A smoking article may include a tobacco medium, a filter for a smoking article, and a wrapper, wherein the filter for the smoking article may be positioned at one end of the tobacco medium, for example, at the rear end or the front end. The tobacco medium and the filter for the smoking article may each include a single segment, or may independently include multiple segments.

[0107] The above tobacco medium comprises a tobacco substance, and the tobacco substance comprises nicotine. In addition, the tobacco medium may additionally comprise an excipient.

[0108] Excipients may include binders, fillers, and other additives. For example, the tobacco medium included in the tobacco medium portion may be manufactured in the form of granules containing tobacco substances and excipients.

[0109] For example, to maintain the shape, strength, and mass of the tobacco medium, a filler may be additionally included. For example, lyocell material may be included in the tobacco medium. Furthermore, lyocell material may be used as a filler.

[0110] The above wrapper can be subdivided into a cigarette paper wrapping the tobacco medium, a filter paper wrapping the filter, and a tipping wrapper combining the tobacco medium and the filter.

[0111] [Filter for smoking items]

[0112] Lyocell material can be used in filters for smoking articles. The lyocell material may be lyocell tow. In one example, the lyocell tow may be crimped.

[0113] For example, the present application relates to a filter for a smoking article. The filter for the smoking article comprises a lyocell material, which may be the same as described above. Furthermore, the filter for the smoking article comprises lyocell tow, which may be the same as described above.

[0114] In one embodiment, the filter for the smoking article may further include a wrapping paper (which may be referred to as a wrapping paper, a filter paper, or a filter wrapping paper). For example, the wrapping paper may be porous paper or non-porous paper that wraps the lyocell tow described above and can maintain the filter shape (e.g., a cylinder or a cylindrical shape).

[0115] In one embodiment, the filter for the smoking article may have a predetermined shape and size.

[0116] In one embodiment, the filter may have a rod shape. For example, the filter for a smoking article may have a cylindrical shape. The filter for a smoking article may be manufactured to have a shape other than a cylindrical shape, but a cylindrical shape may be advantageous from the perspective of including the maximum volume of lyocell material within the filter space.

[0117] In one embodiment, the filter can have a length of, for example, 10 to 50 mm. For example, the length of the filter can have a lower limit of 15 mm or more, 20 mm or more, 25 mm or more, 30 mm or more, 35 mm or more, 40 mm or more, or 45 mm or more, and an upper limit of 45 mm or less, 40 mm or less, 35 mm or less, 30 mm or less, 25 mm or less, 20 mm or less, or 15 mm or less.

[0118] In one embodiment, the filter having the length may have a circular cross-section, and the circumference of the circular cross-section may be 10 to 40 mm. For example, the circumference of the filter may have a lower limit of 15 mm or more, 20 mm or more, 25 mm or more, 30 mm or more, or 35 mm or more, and an upper limit of 35 mm or less, 30 mm or less, 25 mm or less, 20 mm or less, or 15 mm or less.

[0119] In one embodiment, the filter for the smoking article may include lyocell tow and filter paper. Descriptions of the lyocell tow and filter paper are the same as those described above, and are therefore omitted.

[0120] The above-described paper may be porous paper or non-porous paper that can wrap the above-described lyocell tow and maintain a filter shape (e.g., a cylinder or a cylindrical shape).

[0121] In one embodiment, when a porous paper is used, the paper may have a porosity of 10 to 50,000 CU (Coresta Unit). A Coresta Unit is defined as a porosity of 1 cm at a pressure difference of 1 kPa. 2 The volume flow rate (cm) of air passing through the substrate sample (i.e., porous paper) 3 min -1 ) can be defined as.

[0122] In one embodiment, the weight of the paper is 15 to 60 g / cm 2 It could be.

[0123] In one embodiment, the weight of the rod-shaped filter may be greater than or equal to 50 mg.

[0124] Descriptions of other filters for smoking articles and materials included therein are the same as those described above, so they are omitted.

[0125] The present invention is further described in detail through the following manufacturing examples, examples, and comparative examples. However, the examples are intended to illustrate the present invention and are not intended to limit the scope of the present invention.

[0126] Manufacturing example

[0127] Cellulose pulp having viscosity as measured by a viscosity measurement method using a CED (cupriethylene diamine) solution and hemicellulose content, Fe content, and Si content as described in Table 1 below was mixed with an NMMO / H2O solvent having a propyl gallate content of 0.01 wt% to prepare a spinning dope having a concentration (11 wt%). Then, while maintaining the spinning temperature at 110°C in the spinning nozzle, the discharge amount and spinning speed were appropriately adjusted, and the spinning dope was spun.

[0128] The spinning dope on the filament discharged from the spinning nozzle was supplied to the coagulation liquid (the coagulation liquid having a concentration of 75 wt% water and 25 wt% NMMO and a temperature of approximately 25°C) in the coagulation tank through the air gap section. At this time, the cooling air in the air gap section primarily coagulated the spinning dope at a temperature of 8°C and an air flow rate of 200 N㎥ / h. In addition, the concentration of the coagulation liquid was continuously monitored using a sensor and a refractometer.

[0129] Then, the coagulated lyocell filament was washed. Specifically, the filament was introduced into a traction roller, and the NMMO remaining within the filament was removed using a washing solution sprayed from a washing device. Then, the washed filament was immersed in a bath designed to a predetermined emulsion concentration.

[0130] The filaments immersed within the bath were then passed between nip rolls installed at the bath discharge end and fed into a crimp machine for crimping. The crimp machine was adjusted to provide the filaments with an appropriate number of crimps, and crimped tow was produced by passing through the crimp machine.

[0131] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 50.5% CED(cP) 5.25.0 10.01 1.05.23.5 23.05.25.1 Hemicellulose content (wt%) 3.8 4.0 3.7 3.9 7.0 3.8 3.8 4.0 4.0 Fe (wt ppm) 1111111130 5 Si (wt ppm) 105 080 90 50 50 50 50 110

[0132] [Evaluation Method]

[0133] (1) 0.5% CED (cP) - Measured according to TAPPI Standard T230 om-94. Specifically, a pulp sample weighing 0.25 g was collected, dissolved in 25 mL of 0.5% CED solution, and measured using a viscometer at a temperature of 25±0.1℃. The flow time was measured and substituted into the equation below to calculate the viscosity value.

[0134] V = C xtxd

[0135] (V: viscosity of solution (cPs); C: viscometer constant; t: flow time; d: density of solution)

[0136] (2) Hemicellulose content - Measured according to KS M 7044:2016.

[0137] Alpha cellulose: a carbohydrate that is insoluble in 17.5% NaOH aqueous solution at 20°C

[0138] Beta cellulose: a substance that precipitates when the extracted sediment is acidified

[0139] Gamma cellulose: a substance that is not precipitated by acid after being dissolved in a base

[0140] Beta cellulose and gamma cellulose are collectively called "hemicellulose".

[0141] Measurement of alpha cellulose content

[0142] Place 5 g of dried pulp sample in a 300 mL lidded beaker and leave the beaker in a 20°C constant-temperature water bath for 30 minutes. Add 50 mL of 20°C 17.5% NaOH aqueous solution twice, so that the sample is evenly wetted, and leave to stand. After sufficient dissolution, filter by reducing the pressure with a pump, add distilled water, and repeat the reducing pressure and dehydration to wash. The dry weight of the residual fiber was determined.

[0143] Alpha cellulose content (%) = (residual fiber dry weight / sample weight) X 100

[0144] Measurement of hemicellulose content

[0145] Hemicellulose content (%) = 100 - Alpha cellulose content (%)

[0146] (3) Weight-based Fe (ppm) and Si (ppm) - Inorganic components in pulp were measured using ICP-OES (PerkinElmer Avio-550).

[0147] (4) Radiation fairness - Radiation was evaluated as good or bad based on the uniformity of the discharge pressure, whether the multifilament discharged from the detention chamber was broken, and whether the spinneret was contaminated, and was graded O, △, or X based on the criteria below.

[0148] O: The discharge pressure is uniform, multifilament yarn breakage does not occur when discharged from the detention, and there is no contamination of the detention spinneret, so stable long-term production is possible.

[0149] △: The discharge pressure is uniform, but multifilament threads discharged from the detention chamber occasionally break. Contaminants accumulate in the spinneret during long-term production.

[0150] X: Production is impossible due to severe hunting of the discharge pressure or thread breakage in the multifilament discharged from the detention.

[0151] (5) Appearance - The appearance of the produced sample was visually observed to distinguish between good and bad.

[0152] Good: If the sample is close to white

[0153] Defective: If the sample is yellowish or reddish

[0154] (6) Strength of monofilament - After the obtained multifilament specimens were pre-dried at a temperature of 110℃ for 2 hours to a moisture content below the process moisture content, they were left for more than 24 hours under the standard condition of KS K 0901 to reach a moisture equilibrium state, and then the monofilament specimens were separated from the multifilament specimens. The tensile strength of the separated monofilament specimens was measured at a tensile speed of 60 mm / min using a low-speed extension type tensile tester (Instron).

[0155] (7) Tobacco filter cuttability - The cuttability was determined by visually observing the cut section after manufacturing the tobacco rod to determine whether it was good or bad.

[0156] Good: If the cut cross-section of the filter rod is smooth.

[0157] Defective: If the cut section of the filter rod is not smooth, has fibers, clumps, or protrudes.

[0158] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Spinning processability ○○○○△△X△X Appearance ○○○○XXXXX Monofilament strength 3.7 3.6 6.8 7.2 2.5 1.2 8.9 1.8 1.5 Cigarette filter cutability ○○○○○XXXX

[0159]

[0160] ※ Evaluation results: ○ - Good; △ - Average; X - Poor

[0161] As shown in Table 2 above, when the CED viscosity of the cellulose pulp is 4.0 to 11.0 or less, the hemicellulose content is less than 5 wt%, the Fe content is 1 to 30 ppm by weight, and the Si content is 1 to 100 ppm by weight, it was confirmed that it has good spinning processability, good appearance, good tobacco cuttability, and has a monofilament strength of 3 to 7 g / d sufficient to be applied as a filter for smoking articles. In addition, it was confirmed through Comparative Examples 1 to 5 that when any one of the CED viscosity, hemicellulose content, Fe content, and Si content is not satisfied, it is unsuitable as a lyocell material for manufacturing a filter for smoking articles.

[0162] While preferred embodiments of the present invention have been described above with reference to the drawings and examples, these are merely exemplary, and those skilled in the art will appreciate that various modifications and equivalent alternative embodiments are possible. Accordingly, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A lyocell material manufactured from a dope solution containing cellulose pulp and N-methylmorpholine-N-oxide (NMMO), The above cellulose pulp is a lyocell material having a CED viscosity of 4.0 to 11.0 or less, a hemicellulose content of less than 5 wt%, an Fe content of 1 to less than 30 ppm on a weight basis, and a Si content of 1 to less than 100 ppm on a weight basis.

2. In paragraph 1, The above cellulose pulp is a lyocell material having a hemicellulose content of 4 wt% or less.

3. In paragraph 1, The above cellulose pulp is a lyocell material containing 1 to 20 ppm of Fe by mass.

4. In paragraph 1, The above cellulose pulp is a lyocell material containing 1 to 90 ppm of Si by mass.

5. In paragraph 1, The above cellulose pulp is a lyocell material having a polymerization degree of 600 to 1700.

6. In paragraph 1, The above lyocell material comprises one or more lyocell monofilaments, Lyocell material, wherein the monofilament has a strength of 3 g / d to 8 g / d.

7. In paragraph 1, The above lyocell material is a crimped lyocell material.

8. In paragraph 7, The above lyocell material is a lyocell material having 10 to 50 crimps per inch.

9. In paragraph 1, Lyocell towine, Lyocell material 10. In paragraph 9, The above lyocell tow is a lyocell material having an irregular cross-section.

11. In paragraph 9, Lyocell material, wherein the above lyocell tow has a total fineness of 15,000 to 55,000 denier.

12. In paragraph 1, Lyocell material for smoking article filters.

13. Smoking articles containing lyocell material according to Article 1.

14. A step of spinning a dope solution containing cellulose pulp and N-methylmorpholine-N-oxide (NMMO) through a detention chamber; A step of solidifying the radiated dope solution to obtain lyocell multifilament; A step of washing the above lyocell multifilament and then treating it with an oil, and Comprising a step of crimping a multifilament treated with a lubricant to obtain a crimped tow, A method for producing a lyocell material, wherein the cellulose pulp has a CED viscosity of 4.0 to 11.0 or less, a hemicellulose content of less than 5 wt%, an Fe content of 1 ppm or more and less than 30 ppm by weight, and a Si content of 1 ppm or more and less than 100 ppm by weight.

15. In paragraph 14, A method for producing lyocell material, wherein the above cellulose pulp has a hemicellulose content of 4 wt% or less.

16. In Article 14, A method for producing lyocell material, wherein the cellulose pulp contains 1 to 20 ppm of Fe by mass.

17. In paragraph 14, A method for producing lyocell material, wherein the cellulose pulp contains 1 to 90 ppm of Si by mass.

18. In paragraph 14, A method for producing lyocell material, wherein the above cellulose pulp has a polymerization degree of 600 to 1700.