EP4585066A2

EP4585066A2 - Lyocell material, filters, smoking articles and method for preparing thereof

Info

Publication number: EP4585066A2
Application number: EP25150883.4A
Authority: EP
Inventors: Seung Dong SEO; Jong Cheol Jeong; Sang Woo Jin; Eun Young Park; Jeong Hun Lee; Yeong Nam Hwang; Kyeng Bae Ma; Ki Jin AHN; Jin Chul Yang; Min Hee Hwang
Original assignee: Kolon Industries Inc; KT&G Corp
Current assignee: Kolon Industries Inc; KT&G Corp
Priority date: 2024-01-09
Filing date: 2025-01-09
Publication date: 2025-07-16
Also published as: TW202533775A; EP4585066A3; KR20250109158A; WO2025150879A1

Abstract

The present application relates to a lyocell material, a filter for smoking articles, including the lyocell material, and a smoking article including the filter. The lyocell material and the filter for smoking articles, according to the present application, may replace conventional cellulose acetate materials and filters for smoking articles including the same.

Description

TECHNICAL FIELD

The present application relates to a lyocell material, a filter including the same, a smoking article including the filter, and a method of manufacturing the lyocell material.

BACKGROUND ART

Until now, cellulose acetate fibers have been mainly used as cigarette filter materials. Cellulose acetate is known as a biodegradable material, but filters for smoking articles, which are made of cellulose acetate, remain in their original form for one to two years after being buried in soil, and it takes a considerable amount of time until they are completely biodegraded. Considering the amount and toxicity of tobacco products that are discarded and left in the living environment as well as tobacco products that are recovered as waste and landfilled after being used for smoking, it is necessary to further improve the biodegradability of filters for smoking articles. Accordingly, recently, a more environmentally friendly lyocell has been selected as a material to replace cellulose acetate.

DESCRIPTION OF EMBODIMENTS

TECHNICAL PROBLEM

An object of the present application is to provide a lyocell material that can replace commercially available cellulose acetate for filters for smoking articles.
Another object of the present application is to provide a lyocell material for filters for smoking articles of which manufacturing process is environmentally friendly and which has excellent biodegradability upon disposal.
Another object of the present application is to provide a lyocell filter for smoking articles.
Another object of the present application is to provide a smoking article (for example, cigarette) including a lyocell filter.

SOLUTION TO PROBLEM

An aspect of the present application may provide a lyocell material, a filter including the same, a smoking article, and the like.
The lyocell material may include one or more lyocell multifilaments.
The lyocell multifilament may include one or more lyocell monofilaments.
An aspect of the present application may provide a lyocell material (preferably, lyocell tow) including a lyocell multifilament to which crimps are applied, and NMMO (N-Methylmorpholine N-oxide), wherein a content of NMMO is 3000 ppm or less by weight.
In some embodiments, the lyocell multifilament to which crimps are applied may include one or more lyocell monofilaments. The lyocell multifilament to which crimps are applied may be considered as a lyocell multifilament in the present application.
Another aspect of the present application may provide a filter for lyocell smoking articles, the filter including the above-described lyocell material.
Another aspect of the present application may provide a smoking article including the lyocell material or the filter.
Another aspect of the present application may provide methods of manufacturing the lyocell material, and the filter including the same, and the smoking article.
In this specification, 'smoking article' may refer to an article capable of generating aerosols, such as a cigarette, cigar, etc. In this regard, the smoking article may include an aerosol-generating material or an aerosol-forming substrate. Additionally, the smoking article may include a solid material based on a tobacco raw material, such as leaf tobacco, cut tobacco, reconstituted tobacco, etc. In addition, a smoking article may include a volatile compound.
In this specification, the "lyocell multifilament" may refer to a multifilament made of cellulose. In particular, the lyocell multifilament may be a (multi)filament and/or fiber made of cellulose derived or mainly derived from wood pulp, particularly, a semi-synthetic (multi)filament and/or fiber.
In this specification, the "cellulose" may refer to "lyocell cellulose".
In this specification, the "lyocell tow" includes at least one lyocell multifilament or consists of at least one lyocell multifilament.
In this specification, the "yarn fineness" refers to a total fineness of a lyocell multifilament.
In this specification, the "yarn fineness of lyocell a multifilament" may alternatively be referred to as a "total fineness of a lyocell multifilament." Additionally, the total fineness of a lyocell multifilament may be distinguished from the total fineness of a lyocell material.
In this specification, the "crimp" may refer to a wavy, curled or undulating configuration inherent in a material, such as a fiber, (mono)filament, multifilament and/or yarn, or imparted through mechanical, thermal and/or chemical processes. Crimp may be characterized in that it has a periodic deviation from a straight axis along the length of a material, a fiber, (mono)filament, multifilament and/or yarn. One crimp in a material, a fiber, filament, multifilament and/or yarn may be defined as one repeating unit of the periodic deviation. The presence of crimp affects the properties, such as elasticity, bulk, resilience, and texture, of a material and a fabric made of that material.
In this specification, the term "degree of polymerization" (DPw) may refer to the number of monomer units and/or repeating units in a macromolecule, a polymer, or an oligomer molecule. The degree of polymerization may be expressed as Mn/M0, where Mn is a number-average molecular weight of the macromolecule, polymer or oligomer molecule and M0 is a molecular weight of the monomer unit or repeating unit.
In this specification, the "bloomed lyocell material" refers to a lyocell material and/or a lyocell fiber and/or a lyocell multifilament that have been separated, uncoiled, unspooled, loosened or unwrapped from their original compressed and/or rolled state.
In this specification, the "non-circular cross-section" may refer to a cross-sectional shape that deviates from a standard circular shape. The non-circular cross-section may include three or more protrusions, and preferably includes three protrusions. Here, the "protrusion" may refer to a distinct and expanded segment or arm extending outward from the central core or junction point of the cross-section of a monofilament. 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 non-circular cross-section including three protrusions may be referred to as a "Y-shaped cross-section." The lyocell tow may have a Y-shaped cross-section for use in cigarette filters.
In this specification, the "single fineness of a lyocell multifilament" refers to a fineness of one monofilament separated from the lyocell multifilament.
In this specification, the "basis weight" refers to a mass per unit area of a wrapping paper and/or a wrapper. The basis weight of a wrapping paper and/or a wrapper may be determined by measuring the mass and area of the wrapping paper and/or wrapper and dividing the mass of the wrapping paper and/or wrapper by the area.
Unless otherwise specifically defined in this specification, "ppm" may represent weight percent.
In this specification, the "draft ratio" refers to a ratio of elongation of a discharged dope until it is wound, and is expressed as a ratio (V_s/V₀) of a winding velocity (V_s) to a discharge linear velocity (V₀) of a dope discharged from a spinneret. In this case, the discharge linear velocity (V₀) is a velocity (unit: a length of a dope discharged per unit time (for example, unit: m/min)) of a dope discharged from a discharge port of a spinneret, and the winding velocity (V_s) is a velocity (for example, unit: m/min) at which a fiber or filament formed from the discharged dope is wound.
In this specification, the "mechanism" in a washing process refers to a method for achieving washing, and may include, for example, methods for performing washing (for example, a washing tank, a spray), and conditions for performing washing (for example, a washing solution, temperature).
Unless otherwise specifically defined in this specification, when the properties of a lyocell material, a filter for smoking articles, or components or compositions related thereto are affected by temperature, the temperature at which such properties are determined or measured may be room temperature. In this case, the room temperature is a temperature which is not particularly decreased or increased, for example, may be a temperature of 10 °C to 35 °C, particularly 15 °C to 35 °C, 20 °C to 30 °C, or about 25 °C.
In this specification, the content of NMMO was measured through high-performance liquid chromatography (HPLC) analysis.
Hereinafter, the disclosure of the present application will be described in more detail.
The present application relates to a lyocell material. The lyocell material may be used in smoking articles, and, although not particularly limited, the lyocell material may be used in filters for smoking articles.
An aspect of the present application provides a lyocell material including a lyocell multifilament to which crimps are applied, and NMMO, wherein a content of NMMO is 3000 ppm or less by weight.
In some embodiments, the number of crimps in the above-described lyocell material may be 3.94 ea/cm to 23.62 ea/cm (10 ea/inch to 60 ea/inch).
In some embodiments, the number of crimps in the above-described lyocell material may be 9.84 ea/cm to 19.69 ea/cm (25 ea/inch to 50 ea/inch).
In some embodiments, the single fineness of a lyocell multifilament in the above-described lyocell material may be 1.11 to 8.89 dtex (1.0 to 8.0 denier).
In some embodiments, the single fineness of a lyocell multifilament to which crimps are applied in the above-described lyocell material may be1.67 to 12.22 dtex (1.5 to 11.0 denier).
In some embodiments, the yarn fineness of a lyocell multifilament in the above-described lyocell material may be 1,111 to 4,444 tex (10,000 to 40,000 denier).
In some embodiments, the above-described lyocell material may have a total fineness of 1,667 to 6,111 tex (15,000 to 55,000 denier).
In some embodiments, the above-described lyocell material may have a total fineness of 2,222 to 5,556 tex (20,000 to 50,000 denier).
In some embodiments, the content of NMMO in the above-described lyocell material may be 100 ppm or more.
In some embodiments, the content of NMMO in the above-described lyocell material may be 400 ppm or more.
In some embodiments, the above-described lyocell material may satisfy two or more of the following [condition i] to [condition iii]:
[Condition i] the single fineness of a lyocell multifilament to which crimps are applied is 1.67 dtex (1.5 denier) or more.
[Condition ii] the yarn fineness of a lyocell multifilament is 1,111 tex (10,000 denier) or more.
[Condition iii] the total fineness of the lyocell material is 2,222 tex (20,000 denier) or more.
In some embodiments, the above-described lyocell material may satisfy all of [condition i] to [condition iii].
In some embodiments, in the above-described lyocell material, the lyocell multifilament includes one or more monofilaments, and one or more of the monofilaments may have a non-circular cross-section.
In some embodiments, in the above-described lyocell material, the lyocell multifilament includes one or more monofilaments, and all of the monofilaments may have a non-circular cross-section. Alternatively, in some embodiments, the lyocell multifilament includes one or more monofilaments, and all of the monofilaments may have a circular cross-section. In some embodiments, the above-described lyocell material may be a lyocell tow.
In some embodiments, the above-described lyocell material may be used for a filter for smoking articles.
In some embodiments, the above-described lyocell material may not be used for a tire cord
Another aspect of the present application provides a filter for smoking articles, the filter including any one of the above-described lyocell materials.
Another aspect of the present application provides a smoking article including any one of the above-described filters for smoking articles.
Another aspect of the present application provides a method of manufacturing a lyocell material, the method including a lyocell dope spinning process; a coagulation and lyocell multifilament obtainment process; a washing process; an oil treatment process; and a crimp application process. The washing process includes two or more washing tanks, each of which independently includes a washing liquid, and temperatures of the washing liquids are each independent and at least two of the temperatures may be different from each other. In some embodiments, these processes are performed in the mentioned order.
In some embodiments, in the method of manufacturing a lyocell material, the washing process may include two or more washing tanks, each of which independently includes a washing liquid, and temperatures of the washing liquids may be each independently 25°C to 100°C.
In some embodiments, in the method of manufacturing a lyocell material, temperatures of at least two of the washing liquids may be different from each other.
In some embodiments, in the method of manufacturing a lyocell material, when the washing tank in which lyocell multifilaments are washed first is referred to as a first washing tank, the washing liquid included in the first washing tank is referred to as a first washing liquid, the washing tank in which lyocell multifilaments are washed last is referred to as an n-th washing tank, and the washing liquid included in the n-th washing tank is referred to as an n-th washing liquid, the temperature of the first washing liquid may be lower than the temperature of the n-th washing liquid (where n is a natural number of 2 or more).
In some embodiments, in the method of manufacturing a lyocell material, the n-th washing tank may be a tenth washing bath, and preferably, the n-th washing tank may be a third washing tank.
In some embodiments, in the method of manufacturing a lyocell material, each of the washing tanks may be heated.
In some embodiments, in the method of manufacturing a lyocell material, the washing process further includes a sprayer, and the sprayer may spray one or more of the washing liquids.
In some embodiments, in the method of manufacturing a lyocell material, the sprayer may spray the first washing liquid.
In some embodiments, in the method of manufacturing a lyocell material, the sprayer may be placed over the first washing tank.
In some embodiments, in the method of manufacturing a lyocell material, the washing process further includes a dehydrator, and the dehydrator may extract the washing liquid from the lyocell multifilament.
In some embodiments, in the method of manufacturing a lyocell material, the dehydrator may be placed over the washing tank.
In some embodiments, in the method of manufacturing a lyocell material, the dehydrator may be placed over the first washing tank.
In some embodiments, in the method of manufacturing a lyocell material, the dehydrator applies air pressure to the lyocell multifilament to extract the washing liquid from the lyocell multifilament, and the air pressure may be 9.81 N/cm² to 147.10 N/cm² (1 kgf/cm² to 15 kgf/cm²).
In some embodiments, the content of NMMO included in the lyocell material is 3000 ppm or less. As a result, a filter for smoking articles, the filter including the above-described lyocell material, may provide a user with a usability equivalent to that of a filter for smoking articles, the filter including a cellulose acetate material.
On the other hand, when the content of NMMO included in the lyocell material exceeds 3000 ppm, the user may experience different tastes and odors from the filter for smoking articles, and in particular, the user may feel a sweet or sour odor from the filter for smoking articles.
In some embodiments, the content of NMMO included in the lyocell material may be 3000 ppm or less, 2950 ppm or less, 2900 ppm or less, 2850 ppm or less, 2800 ppm or less, 2750 ppm or less, 2700 ppm or less, 2650 ppm or less, 2600 ppm or less, 2550 ppm or less, 2500 ppm or less, 2450 ppm or less, 2400 ppm or less, 2350 ppm or less, 2300 ppm or less, 2250 ppm or less, 2200 ppm or less, 2150 ppm or less, 2100 ppm or less, 2050 ppm or less, 2000 ppm or less, 1950 ppm or less, 1900 ppm or less, 1850 ppm or less, 1800 ppm or less, 1750 ppm or less, 1700 ppm or less, 1650 ppm or less, 1600 ppm or less, 1550 ppm or less, 1500 ppm or less, 1450 ppm or less, 1400 ppm or less, 1350 ppm or less, 1300 ppm or less, 1250 ppm or less, 1200 ppm or less, 1150 ppm or less, 1100 ppm or less, 1050 ppm or less, 1000 ppm or less, 950 ppm or less, 900 ppm or less, 850 ppm or less, 800 ppm or less, 750 ppm or less, 700 ppm or less, 650 ppm or less, 600 ppm or less, 550 ppm or less, or 500 ppm or less. As the content of NMMO included in the lyocell material decreases, a probability that a user will experience different taste and odors from the filter for smoking articles may further decrease. Additionally, in some embodiments, the lyocell material may have a crimp of 3.94 ea/cm to 23.62 ea/cm (10 ea/inch to 60 ea/inch) while satisfying an NMMO content of 3000 ppm or less. As a result, the lyocell material may be suitably used in manufacturing a filter for smoking articles, and the filter for smoking articles may provide sufficient filtering ability. On the other hand, a lyocell multifilament to which crimps are not applied may be difficult to manufacture a filter for smoking articles due to limited swelling, or even when a filter for smoking articles is successfully manufactured, this filter may not be able to provide sufficient filtering ability because porosity in the filter is too large and uneven.
Additionally, in some embodiments, the lyocell material may satisfy a single fineness of 1.67 dtex (1.5 denier) or more, a yarn fineness of lyocell multifilament of 1,111 tex (10,000 denier) or more, and/or a total fineness of 2,222 tex (20,000 denier) or more, so as to be suitably used to manufacture a filter for smoking articles, while satisfying an NMMO content of 3000 ppm or less. As a result, the lyocell material may be suitably used in manufacturing a filter for smoking articles, and the filter for smoking articles may provide a user with a good quality feeling of use. In particular, in order to implement the cross-sectional circumference of a general filter for smoking articles, it is desirable that yarn fineness of the lyocell multifilament be 1,111 tex (10,000 denier) or more. In addition, the fineness of the lyocell multifilament and the number of monofilaments may be adjusted depending on the type of smoking articles, so that the yarn fineness of the lyocell multifilament may be appropriately adjusted.
As described above, as the single fineness increases in the process of adjusting the yarn fineness of the lyocell multifilament, extraction of NMMO from the inside of the monofilament may become difficult. Alternatively, as the number of monofilaments increases, extraction of NMMO from the inner monofilaments among the stacked monofilaments may become difficult. Therefore, even by using conventional washing methods, it is highly likely that reducing the content of NMMO to 3000 ppm or less in the lyocell material having a total filament yarn fineness of 1,111 tex (10,000 denier) or more will be restricted.
On the other hand, the content of NMMO in the lyocell material having a yarn fineness of 1,111 tex (10,000 denier) or more may be adjusted to 3000 ppm or less through a specially designed process such as a washing process to be described below. As a result, a filter for smoking articles, the filter including the above lyocell multi-material, may provide a user with both sufficient filtering ability and a high-quality feeling of use.

[Non-circular cross-section]

At least one of the lyocell monofilaments included in the lyocell material of the present application may have a non-circular cross-section. The "non-circular" means that the shape of the outline of a cross-section is not circular, and the "cross-section" may be a cross-section obtained by cutting the lyocell monofilament virtually or actually perpendicular to the length direction of the filament.
The outline of the non-circular cross-section may come into contact with an imaginary first circle and an imaginary second circle, respectively. Additionally, the imaginary second circle may be within the imaginary first circle, and/or the imaginary second circle may be within the imaginary first circle. The "imaginary first circle" may also be referred to as a "imaginary circumcircle" and/or a "circumcircle", and/or the "imaginary second circle" may also be referred to as a "imaginary incircle" and/or a "incircle".
The imaginary first circle may be a circle having the smallest area value among the circles drawn to completely encompass one cross-section of a monofilament. The imaginary second circle may be a circle having the largest area value among the circles drawn within the cross section of the monofilament.
When a circumcircle including the cross section of the monofilament can be drawn, the imaginary first circle may be the above-described circumcircle. When an incircle can be drawn within the cross section of the monofilament, the imaginary second circle may be the above-described incircle.
The non-circular cross-section may have a shape including a plurality of protrusions, for example, a Y-shaped cross-section including three protrusions. It can be understood that the plurality of protrusions are formed integrally with the imaginary second circle as a center and that their ends are in contact with the imaginary first circle. The terms mentioned herein have the same meanings as described above.
The non-circularity of a monofilament may be defined by the following Equation 1. $Non - circularity = r 1 / r 2$
Here, r1 is a radius of the imaginary first circle, and r2 is a radius of the imaginary second circle.
For example, the radius of the imaginary first circle may be 4 µm to 40 µm, the radius of the imaginary second circle may be 2 µm to 14 µm, and the non-circularity may be 1.01 to 10.
Additionally, the space occupancy of a monofilament may be defined by the following Equation 2. $Space occupancy = (S 1 / S 2) \times 100 (%)$
Here, S1 is an area of the imaginary first circle, and S2 is a cross-sectional area of a monofilament included in a lyocell fiber.
For example, the space occupancy of a monofilament having a non-circular cross-section may be 120 % to 600 %.

[Fineness]

The lyocell material of the present application includes lyocell multifilaments, and the lyocell multifilaments may have a fineness suitable for manufacturing a filter for smoking articles and securing its function.
For example, the single fineness of monofilaments forming the lyocell multifilament may be 1.67 to 8.89 dtex (1.5 to 8.0 denier). In this case, the single fineness of a lyocell multifilament refers to a fineness of one monofilament separated from the lyocell multifilament before crimps are applied.
In particular, the single fineness of the lyocell multifilament may be, for example, 8.33 dtex (7.5 denier) or less, 7.78 dtex (7.0 denier) or less, 7.22 dtex (6.5 denier) or less, 6.67 dtex (6.0 denier) or less, 6.11 dtex (5.5 denier) or less, 5.56 dtex (5.0 denier) or less, 5.00 dtex (4.5 denier) or less, 4.44 dtex (4.0 denier) or less, 3.89 dtex (3.5 denier) or less, 3.33 dtex (3.0 denier) or less, 2.78 dtex (2.5 denier) or less, 2.22 dtex (2.0 denier) or less, or 1.67 dtex (1.5 denier) or less. Further, the lower limit thereof may be, for example, 1.67 dtex (1.5 denier) or more, 2.22 dtex (2.0 denier) or more, 2.78 dtex (2.5 denier) or more, 3.33 dtex (3.0 denier) or more, 3.89 dtex (3.5 denier) or more, 4.44 dtex (4.0 denier) or more, 5.00 dtex (4.5 denier) or more, 5.56 dtex (5.0 denier) or more, 6.11 dtex (5.5 denier) or more, 6.67 dtex (6.0 denier) or more, 7.22 dtex (6.5 denier) or more, 7.78 dtex (7.0 denier) or more, or 8.33 dtex (7.5 denier) or more. Satisfying the above range may be more advantageous in securing stable physical properties (e.g., hardness or draw resistance implementation, etc.) and processability of a filter for smoking articles.
In particular, when the single fineness of the monofilament forming the lyocell multifilament is less than 1.11 dtex (1.0 denier), a draft ratio, which means a tensile rate immediately after discharge from a spinneret, may be too high, thus making it difficult to secure stability in a spinning process.
Conversely, when the single fineness of the monofilament is more than 8.89 dtex (8.0 denier), initial coagulation may be restricted by the thickness of a single fiber. As a result, the continuous production of the lyocell material may be restricted, such as the retention of viscosity and the rolling of the lyocell material by rollers in the early stage of washing.
In some embodiments, the single fineness of the monofilaments forming the lyocell multifilament to which crimps are applied may be 1.67 to 12.22 dtex (1.5 to 11.0 denier). In this case, the single fineness of a filament refers to a fineness of one monofilament separated from a multifilament to which crimps are applied.
In particular, the single fineness of the lyocell multifilament to which crimps are applied may be, for example, 11.67 dtex (10.5 denier) or less, 11.11 dtex (10.0 denier) or less, 10.56 dtex (9.5 denier) or less, 10.00 dtex (9.0 denier) or less, 9.44 dtex (8.5 denier) or less, 8.89 dtex (8.0 denier) or less, 8.33 dtex (7.5 denier) or less, 7.78 dtex (7.0 denier) or less, 7.22 dtex (6.5 denier) or less, 6.67 dtex (6.0 denier) or less, 6.11 dtex (5.5 denier) or less, 5.56 dtex (5.0 denier) or less, 5.00 It can be dtex (4.5 denier) or less, 4.44 dtex (4.0 denier) or less, 3.89 dtex (3.5 denier) or less, 3.33 dtex (3.0 denier) or less, 2.78 dtex (2.5 denier) or less, or 2.22 dtex (2.0 denier) or less. Further, the lower limit thereof may be, for example, 2.22 dtex (2.0 denier) or more, 2.78 dtex (2.5 denier) or more, 3.33 dtex (3.0 denier) or more, 3.89 dtex (3.5 denier) or more, 4.44 dtex (4.0 denier) or more, 5.00 dtex (4.5 denier) or more, 5.56 dtex (5.0 denier) or more, 6.11 dtex (5.5 denier) or more, 6.67 dtex (6.0 denier) or more, 7.22 dtex (6.5 denier) or more, 7.78 dtex (7.0 denier) or more, 8.33 dtex (7.5 denier) or more, 8.89 dtex (8.0 denier) or more, 9.44 dtex (8.5 denier) or more, 10.00 dtex (9.0 denier) or more, 10.56 dtex (9.5 denier) or more, 11.11 dtex (10.0 denier) or more, or 11.67 dtex (10.5 denier) or more. Satisfying the above range may be more advantageous in securing stable physical properties (for example, hardness or draw resistance implementation, etc.) and processability of a filter for smoking articles.
Additionally, the lyocell multifilament may have a yarn fineness of 1,111 to 4,444 tex (10,000 to 40,000 denier). For example, the lower limit of the yarn fineness may be 1,222 tex (11,000 denier) or more, 1,333 tex (12,000 denier) or more, 1,444 tex (13,000 denier) or more, 1,556 tex (14,000 denier) or more, 1,667 tex (15,000 denier) or more, 1,778 tex (16,000 denier) or more, 1,889 tex (17,000 denier) or more, 2,000 tex (18,000 denier) or more, 2,111 tex (19,000 denier) or more, 2,222 tex (20,000 denier) or more, 2,333 tex (21,000 denier) or more, 2,444 tex(22,000 denier) or more, 2,556 tex(23,000 denier) or more, 2,667 tex(24,000 denier) or more, 2,778 tex(25,000 denier) or more, 2,889 tex(26,000 denier) or more, 3,000 tex(27,000 denier) or more, 3,111 tex(28,000 denier) or more, 3,222 tex(29,000 denier) or more, 3,333 tex(30,000 denier) or more, 3,444 tex(31,000 denier) or more, 3,556 tex(32,000 denier) or more, 3,667 tex(33,000 denier) or more, 3,778 tex (34,000 denier) or more, 3,889 tex (35,000 denier) or more, 4,000 tex (36,000 denier) or more, 4,111 tex (37,000 denier) or more, 4,222 tex (38,000 denier) or more, 4,333 tex (39,000 denier) or more, and the upper limit is specifically 4,333 tex (39,000 denier) or less, 4,222 tex (38,000 denier) or less, 4,111 tex (37,000 denier) or less, 4,000 tex (36,000 denier) or less, 3,889 tex (35,000 denier) or less, 3,778 tex (34,000 denier) or less, 3,667 tex (33,000 denier) or less, 3,556 tex (32,000 denier) or less, 3,444 tex (31,000 denier) or less, 3,333 tex (30,000 denier) or less, 3,222 tex (29,000 denier) or less, 3,111 tex (28,000 denier) or less, 3,000 tex (27,000 denier) or less, 2,889 tex (26,000 denier) or less, 2,778 tex (25,000 denier) or less, 2,667 tex (24,000 denier) or less, 2,556 tex (23,000 denier) or less, 2,444 tex (22,000 denier) or less, 2,333 tex (21,000 denier) or less, 2,222 tex (20,000 denier) or less, 2,111 tex (19,000 denier) or less, 2,000 tex (18,000 denier) or less, 1,889 tex (17,000 denier) or less, 1,778 tex (16,000 denier) or less, 1,667 tex (15,000 denier) or less, 1,556 tex (14,000 denier) or less, 1,444 tex (13,000 denier) or less, 1,333 tex (12,000 denier) or less, or 1,222 tex (11,000 denier) or less. When the yarn fineness is outside the above range, the amount of a lyocell material filling a filter wrapper may be excessively small or large, so that sufficient filter properties (for example, hardness or draw resistance, etc.) may not be secured, and the manufacture of a filter for smoking articles may be restricted.
In particular, when the yarn fineness (that is, total fineness of lyocell multifilament) is less than 1,111 tex (10,000 denier), the manufacture of a filter for smoking articles from a lyocell material may be restricted. In particular, the filling of a lyocell material may not be sufficient, and the implementation of a rod shape may be restricted.
Additionally, when the yarn fineness is more than 4,444 tex (40,000 denier), the manufacture of a filter for smoking articles from a lyocell material may be restricted. In particular, excessive filling of a lyocell material may occur, which may cause a filter for smoking articles to burst. As a result, the manufacture of a filter may be restricted.
Although there are no particular restrictions on the method of measuring yarn fineness, for example, a multifilament before the application of crimps, to be measured, is left in a room with a temperature condition of 20±2°C and a humidity of 65±4%RH for 24 hours to achieve moisture equilibrium. One end of the stabilized sample is fixed, the other end thereof is pulled to have sufficient tension throughout the multifilament, and then cut to 90 cm. The weight of the obtained sample is measured and converted into denier.
The yarn fineness of a lyocell multifilament may alternatively be referred to as "total fineness of a lyocell multifilament". Additionally, the total fineness of a lyocell multifilament may be distinguished from the total fineness of a lyocell material.
For example, the total fineness of the lyocell material may be 1,667 to 6,111 tex (15,000 to 55,000 denier). For example, the lower limit of the total fineness may be 1,778 tex (16,000 denier) or more, 1,833 tex (16,500 denier) or more, 1,889 tex (17,000 denier) or more, 1,944 tex (17,500 denier) or more, 2,000 tex (18,000 denier) or more, 2,056 tex (18,500 denier) or more, 2,111 tex (19,000 denier) or more, 2,167 tex (19,500 denier) or more, 2,222 tex (20,000 denier) or more, 2,278 tex (20,500 denier) or more, 2,333 tex (21,000 denier) or more, 2,389 tex(21,500 denier) or more, 2,444 tex(22,000 denier) or more, 2,500 tex(22,500 denier) or more, 2,556 tex(23,000 denier) or more, 2,611 tex(23,500 denier) or more, 2,667 tex(24,000 denier) or more, 2,722 tex(24,500 denier) or more, 2,778 tex(25,000 denier) or more, 2,833 tex(25,500 denier) or more, 2,889 tex(26,000 denier) or more, 2,944 tex(26,500 denier) or more, 3,000 tex(27,000 denier) or more, 3,056 tex(27,500 denier) or more, 3,111 tex(28,000 denier) or more, 3,167 tex(28,500 denier) or more, 3,222 tex(29,000 denier) or more, 3,287 tex(29,500 denier) or more, 3,333 tex(30,000 denier) or more, 3,389 tex(30,500 denier) or more, 3,444 tex(31,000 denier) or more, 3,500 tex(31,500 denier) or more, 3,556 tex(32,000 denier) or more, 3,611 tex(32,500 denier) or more, 3,667 tex(33,000 denier) or more, 3,722 tex(33,500 denier) or more, 3,778 tex(34,000 denier) or more, 3,833 tex(34,500 denier) or more, 3,889 tex(35,000 denier) or more, 3,944 tex(35,500 denier) or more, 4,000 tex(36,000 denier) or more, 4,056 tex(36,500 denier) or more, 4,111 tex(37,000 denier) or more, 4,167 tex(37,500 denier) or more, 4,222 tex(38,000 denier) or more, 4,278 tex(38,500 denier) or more, 4,333 tex(39,000 denier) or more, 4,389 tex(39,500 denier) or more, 4,444 tex(40,000 denier) or more, 4,500 tex(40,500 denier) or more, 4,556 tex(41,000 denier) or more, 4,611 tex(41,500 denier) or more, 4,667 tex(42,000 denier) or more, 4,722 tex(42,500 denier) or more, 4,778 tex(43,000 denier) or more, 4,833 tex(43,500 denier) or more, 4,889 tex(44,000 denier) or more, 4,944 tex(44,500 denier) or more, 5,000 tex(45,000 denier) or more, 5,056 tex(45,500 denier) or more, 5,111 tex(46,000 denier) or more, 5,167 tex(46,500 denier) or more, 5,222 tex(47,000 denier) or more, 5,278 tex(47,500 denier) or more, 5,333 tex(48,000 denier) or more, 5,389 tex(48,500 denier) or more, 5,444 tex(49,000 denier) or more, 5,500 tex(49,500 denier) or more, 5,556 tex(50,000 denier) or more, 5,611 tex(50,500 denier) or more, 5,667 tex(51,000denier) or more, 5,722 It can be 51,500 denier (tex) or more, 5,778 tex (52,000 denier) or more, 5,833 tex (52,500 denier) or more, 5,889 tex (53,000 denier) or more, 5,944 tex (53,500 denier) or more, 6,000 tex (54,000 denier) or more, or 6,056 tex (54,500 denier) or more. Further, the upper limit thereof may be, for example, 6,056 tex (54,500 denier) or less, 6,000 tex (54,000 denier) or less, 5,944 tex (53,500 denier) or less, 5,889 tex (53,000 denier) or less, 5,833 tex (52,500 denier) or less, 5,778 tex (52,000 denier) or less, 5,722 tex (51,500 denier) or less, 5,667 tex (51,000 denier) or less, 5,611 tex (50,500 denier) or less, 5,556 tex (50,000 denier) or less, 5,500 tex (49,500 denier) or less, 5,444 tex(49,000 denier) or less, 5,389 tex(48,500 denier) or less, 5,333 tex(48,000 denier) or less, 5,278 tex(47,500 denier) or less, 5,222 tex(47,000 denier) or less, 5,167 tex(46,500 denier) or less, 5,111 tex(46,000 denier) or less, 5,056 tex(45,500 denier) or less, 5,000 tex(45,000 denier) or less, 4,944 tex(44,500 denier) or less, 4,889 tex(44,000 denier) or less, 4,833 tex(43,500 denier) or less, 4,778 tex (43,000 denier) or less, 4,722 tex (42,500 denier) or less, 4,667 tex (42,000 denier) or less, 4,611 tex (41,500 denier) or less, 4,556 tex (41,000 denier) or less, 4,500 tex (40,500 denier) or less, 4,444 tex (40,000 denier) or less, 4,389 tex (39,500 denier) or less, 4,333 tex (39,000 denier) or less, 4,278 tex (38,500 denier) or less, 4,222 tex (38,000 denier) or less, 4,167 tex (37,500 denier) or less, 4,111 tex (37,000 denier) or less, 4,056 tex (36,500 denier) or less, 4,000 tex (36,000 denier) or less, 3,944 tex (35,500 denier) or less, 3,889 tex (35,000 denier) or less, 3,833 tex (34,500 denier) or less, 3,778 tex (34,000 denier) or less, 3,722 tex (33,500 denier) or less, 3,667 tex (33,000 denier) or less, 3,611 tex (32,500 denier) or less, 3,556 tex (32,000 denier) or less, 3,500 tex (31,500 denier) or less, 3,444 tex (31,000 denier) or less, 3,389 tex (30,500 denier) or less, 3,333 tex (30,000 denier) or less, 3,278 tex (29,500 denier) or less, 3,222 tex (29,000 denier) or less, 3,167 tex (28,500 denier) or less, 3,111 tex (28,000 denier) or less, 3,056 tex (27,500 denier) or less, 3,000 tex (27,000 denier) or less, 2,944 tex (26,500 denier) or less, 2,889 tex (26,000 denier) or less, 2,833 tex (25,500 denier) or less, 2,778 tex (25,000 denier) or less, 2,722 tex (24,500 denier) or less, 2,667 tex (24,000 denier) or less, 2,611 tex (23,500 denier) or less, 2,556 tex (23,000 denier) or less, 2,500 tex (22,500 denier) or less, 2,444 tex (22,000 denier) or less, 2,389 tex (21,500 denier) or less, 2,333 tex (21,000 denier) or less, 2,278 tex (20,500 denier) or less, 2,222 tex (20,000 denier) or less, 2,167 tex (19,500 denier) or less, 2,111 It can be 19,000 denier (tex) or less, 2,056 denier (tex) or less, 2,000 denier (tex) or less, 1,944 denier (tex) or less, 1,889 denier (tex) or less, 1,833 denier (tex) or less, 1,778 denier (tex) or less, or 1,722 denier (tex) or less. When the total fineness is outside the above range, the processability of manufacturing a filter for smoking articles may not be good (continuous process by cutting is impossible), and when the amount of tow filling a filter wrapper during a process of manufacturing a filter for smoking articles is too small or too large, it may be difficult to secure sufficient properties (e.g., hardness or draw resistance, etc.) of the filter.
Although there are no particular restrictions on the method of measuring fineness, for example, a 2 m sample is collected from the lyocell material to be measured, for example, a lyocell tow. The collected sample is left in a room with a temperature condition of 20±2°C and a humidity condition of 65±4%RH for 24 hours and stabilized. One end of the stabilized sample is fixed, and the other end thereof is provided with a 2 kg of weight. Crimps are released under load, and the elongated sample is held (for example. stabilized) for 30 seconds. Thereafter, the sample is cut into 90 cm to obtain a specimen. The weight of the obtained specimen is measured.
According to a denier conversion method, the total fineness of the lyocell material is calculated in a denier scale by multiplying the measured weight by 10,000. Additionally, the single fineness of the lyocell material is defined as a value obtained by dividing the total fineness of the lyocell material by the number of monofilament strands of the lyocell multifilament.
As described above, the total fineness of the lyocell material may be determined by the single fineness of the lyocell multifilament before the application of crimps, the number of monofilament strands, the shape of a crimp, and the number of crimps. Alternatively, the total fineness of the lyocell material may be determined by the single fineness of the lyocell multifilament to which crimps are applied and the number of monofilament strands of the lyocell multifilament to which crimps are applied.
In the present application, the total fineness of a lyocell material (for example, lyocell tow) suitable for manufacturing a filter for smoking articles and securing its function may be secured, and the single fineness and the number of monofilament strands of a lyocell multifilament to which crimps are applied may be controlled to secure the total fineness.

[Number of crimps]

In some embodiments, the lyocell multifilament may have crimps of 3.94 to 23.62 per centimeter (10 to 60 per inch). For example, the number of crimps may be 5.91 ea/cm(15 ea/inch) or more, 7.87 ea/cm(20 ea/inch) or more, 9.84 ea/cm(25 ea/inch) or more, 11.81 ea/cm(30 ea/inch) or more, 13.78 ea/cm(35 ea/inch) or more, 15.75 ea/cm(40 ea/inch) or more, or 17.72 ea/cm(45 ea/inch) or more, and the upper limit may be, for example, 21.65 ea/cm(55 ea/inch) or less, 19.69 ea/cm(50 ea/inch) or less, 17.72 ea/cm(45 ea/inch) or less, 15.75 ea/cm(40 ea/inch) or less, 13.78 ea/cm(35 ea/inch) or less, 11.81 ea/cm(30 ea/inch) or less, or 9.84 ea/cm(25 ea/inch) or less. The number of crimps and the uniformity thereof may be controlled through pressure and temperature conditions, etc., in the crimping process to be described below.
Although not particularly limited, the number of crimps may be measured using, for example, a single fiber property evaluation apparatus (for example, Favimat). In particular, the manufactured lyocell material (preferably lyocell tow) sample may be left and stabilized for 24 hours under conditions of a temperature of 20±2°C and a humidity of 65±4%. A specimen may be collected from the stabilized samples without damaging the crimps. The collected specimen may be mounted on a dedicated jig with a length (gauge length) of 10 to 30 mm. The initial load at measurement may be 0.44 cN/tex (0.05 g/de) and the crimp sensitivity at measurement may be 0.01 mm. The number of crimps may be measured under the above-described conditions (that is, temperature of 20±2°C, humidity of 65±4%).
Although not particularly limited, the lyocell material manufactured to satisfy the single fineness, total fineness, and/or the number of crimps, described above, may be used in smoking articles.

[Lyocell material]

According to an aspect of the present application, there is provided a lyocell material including a lyocell multifilament to which crimps are applied, and NMMO, wherein the content of NMMO is 3000 ppm or less. The lyocell material has properties suitable for use in filters for smoking articles.
Additionally, the content of NMMO may be 100 ppm or more, and may be 400 ppm or more. From a technical viewpoint, in the process of maximizing NMMO extraction, damage to the lyocell multifilament may be caused depending on the method thereof, and the continuous manufacture of the lyocell material may be restricted.
In particular, the number of crimps in the lyocell material may be 3.94 ea/cm to 23.62 ea/cm (10 ea/inch to 60 ea/inch), and preferably, the number of crimps may be 9.84 ea/cm to 19.69 ea/cm (25 ea/inch to 50 ea/inch). By allowing the number of crimps to satisfy the above-described range, when a filter for smoking articles is manufactured using the lyocell material, good manufacturing processability and filtering ability can be achieved.
Additionally, the single fineness of the monofilament forming the lyocell multifilament to which crimps are applied may be 1.67 to 12.22 dtex (1.5 to 11.0 denier), and preferably, the single fineness of the monofilament forming the lyocell multifilament to which crimps are applied may be 2.22 to 6.67 dtex (2.0 to 6.0 denier). When the single fineness of the monofilament forming the lyocell multifilament to which crimps are applied is within the above range, the lyocell material may provide a specific surface area suitable for a filter for smoking articles.
Additionally, the total fineness (that is, yarn fineness) of the lyocell multifilament before the application of crimps may be 1,111 to 4,444 tex (10,000 to 40,000 denier). Additionally, the lyocell material may have a total fineness of 1,667 to 6,111 tex (15,000 to 55,000 denier), and, preferably, may have a total fineness of 2,222 to 5,556 tex (20,000 to 50,000 denier). Since the yarn fineness and the total fineness of the lyocell material satisfy the above-described ranges, the lyocell material may provide properties suitable for a filter for smoking articles, such as an increase in swelling due to the application of crimps, improvement in filter manufacturing processability, and improvement in filtering ability.
In particular, the lyocell material may satisfy two or more of the following [condition i] to [condition iii]. By [condition i] to [condition iii], a difficulty in a process of washing NMMO from the lyocell material may increase. For example, when the single fineness increases, removal of NMMO from the inside of the monofilament may become more difficult.
[Condition i] the single fineness of the lyocell multifilament to which crimps are applied is 1.67 dtex (1.5 denier) or more.
[Condition ii] the yarn fineness of the lyocell multifilament is 1,111 tex (10,000 denier) or more.
[Condition iii] the total fineness of the lyocell material is 2,222 tex (20,000 denier) or more.
Therefore, in terms of manufacturing the lyocell material, a process for manufacturing a lyocell material satisfying two or more of the above [condition i] to [condition iii] and having an NMMO content of 3000 ppm or less may be more difficult than a process for manufacturing a lyocell material satisfying only one of the above [condition i] to [condition iii] or not satisfying any one of the above and having an NMMO content of 3000 ppm or less.
In some embodiments, the lyocell material may satisfy all of [condition i] to [condition iii].
Additionally, the lyocell multifilament includes one or more monofilaments, wherein at least one of the monofilaments may have a non-circular cross-section, and, preferably, all of the monofilaments may have a non-circular cross-section.
In some embodiments, the lyocell material may be a lyocell tow, and may be used for a filter for smoking articles. Meanwhile, in some embodiments, the lyocell material may not be used for tire cord.

[Binder]

In a non-limiting example, the lyocell material may further include a binder. The binder may be present, for example, on the surface of the lyocell multifilament, or between the lyocell multifilaments and/or between monofilaments. The binder may increase the hardness of a filter for smoking articles, thereby preventing a filter from being caught during a process of manufacturing a filter or a process of manufacturing a smoking article (for example, cigarette).
The type of a usable binder is not particularly limited, and any known binder may be used as long as it does not hinder the purpose of the present invention. For example, a binder providing sufficient compatibility with an oil used in the present application, improving the hardness of a filter, and providing excellent binding force may be used.
In a non-limiting example, the binder may include a polyester-based binder, a cellulosic-based binder, and/or a vinyl-based binder.
Although not particularly limited, a polyester-based binder including at least one selected from the group consisting of alkylene, arylene and heteroarylene, each having 5 to 12 carbon atoms, may be used.
Examples of the cellulose-based binder may include, but are not limited to, hydroxypropyl methyl cellulose (HPMC), ethyl cellulose (EC), methyl cellulose (MC), and/or carboxymethyl cellulose (CMC).
In some embodiments, the cellulose-based binder is selected from the group consisting of hydroxypropylmethylcellulose, ethylcellulose, methylcellulose, carboxymethylcellulose, and combinations thereof.
Examples of the vinyl-based binder may include, but are not limited to, polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), and/or ethylene vinyl acetate (EVAc).
In some embodiments, the vinyl-based binder is selected from the group consisting of polyvinylpyrrolidone, polyvinyl alcohol, ethylene vinyl acetate, and combinations thereof.
A method of applying (coating) the binder to a lyocell material will be described later.

[Oil]

The lyocell material may include a lyocell multifilament; and an oil applied onto the lyocell multifilament. The oil includes (a) an esterification product of a fatty acid having 16 or more carbon atoms and an aliphatic monohydric alcohol; and (b) an esterification product of sorbitan and a fatty acid having 16 or more carbon atoms. This oil may be applied to some or all of monofilaments or multifilaments constituting the lyocell material. Additionally, the oil may penetrate among filaments.
The oil including at least the component (a) and the component (b) may have hydrophobicity. As a result, the lyocell material treated with the oil has excellent spreading properties.
In some embodiments, the lyocell material may include a preset content of the oil. In this case, the content of the oil may refer to OPU (wt%) to be described later. OPU may refer to "oil pick up ratio". For example, the lyocell material may include an oil in a content of 0.1 wt% or more based on 100 wt% of the total lyocell material. In particular, the content of the oil may be 0.5 wt% or more, 1.0 wt% or more, 1.5 wt% or more, 2.0 wt% or more, 2.5 wt% or more, 3.0 wt% or more, especially 3.5 wt% or more, 4.0 wt% or more, 4.2 wt% or more, 4.5 wt% or more, 5.0 wt% or more, 5.5 wt% or more, 6.0 wt% or more, 6.5 wt% or more, 7.0 wt% or more, 7.5 wt% or more, 8.0 wt% or more, 8.5 wt% or more, 9.0 wt% or more, or 9.5 wt% or more. Further, the upper limit thereof may be, for example, 20.0 wt% or less, 18.0 wt% or less, 17.0 wt% or less, 16.0 wt% or less, 15.0 wt% or less, 14.5 wt% or less, 14.0 wt% or less, 13.5 wt% or less, 13.0 wt% or less, 12.5 wt% or less, 12.0 wt% or less, 11.5 wt% or less, 11.0 wt% or less, 10.5 wt% or less, 10 wt% or less, 9.5 wt% or less, 9.0 wt% or less, 8.5 wt% or less, 8.0 wt% or less, 7.8 wt% or less, or 7.6 wt% or less.
As a method of measuring the content (OPU) of the oil, for example, an extrusion method may be used. For example, a sample (e.g., 2 to 5 g, specifically about 2.5 g) is collected (in this case, the weight of the collected sample is referred to as a sample weight), and is introduced into a syringe-shaped container. The material of the container is not particularly limited, but may be SUS (stainless steel). Subsequently, a solvent (e.g., methanol) is introduce into the container containing the sample (the amount of the introduced solvent may be 10 ml or less (e.g., about 8 ml)). When adding the solvent to the sample, a dropping method may be used, and a dropping speed may be adjusted uniformly. And, as described above, the solvent introduced into the container is allowed to drop from one end of the syringe-shaped container onto a plate. In this case, the plate is pre-weighed (the weighed weight is referred to as plate weight A), and the plate is mounted so that the solvent dropped onto the plate can fly away (i.e., evaporate) at a temperature of 120°C to 130°C (e.g., 125°C). The introduction and dropping of the solvent are performed three times, and the sample is pressed once using a syringe-shaped container to apply pressure (e.g., 98 N/cm² (10 kgf/cm²) or less, 49 N/cm² (5 kgf/cm²) or less, or 18-39 N/cm² (2-4 kgf/cm²)) to the sample. This process allows the solvent and oil present in the sample to be sufficiently extruded. The sample is squeezed under pressure until no solvent comes out. Then, the plate is stored in a desiccator for 5 to 10 minutes, and the weight of the plate containing the sample (plate weight B) is measured. Then, the content of the oil is calculated according to Equation below. Content of oil by extrusion (OPU, % or wt%) = {(plate weight B - plate weight A)/(sample weight)} × 100
In addition, the lyocell material that serves as the standard for the content of the oil may be at least an oil-treated lyocell multifilament. For example, the lyocell material may be a lyocell multifilament to which a first oil treatment (as described below) has been applied, a lyocell multifilament to which a first oil treatment and a second oil treatment (as described below) have been applied, or a lyocell multifilament to which a binder treatment to be described below has been applied together with the above-described oil treatment. Additionally, the lyocell multifilament treated with an oil and/or a binder may be a lyocell multifilament to which crimps are applied.
In relation to the oil of the present application, the component (a) may be a compound that can function as a type of lubricant or oil, and may be a component that is harmless to the human body enough to be used in food. The component (a) provides lubricity to fibers introduced into a crimper. When lubricity is insufficient, lyocells may clump together and not pass through the crimper, and when lubricity is too high, crimps may not form properly. Taking these functions into consideration, the content of the component (a) may be controlled as described below.
In relation to the component (a), the type of fatty acid having 16 or more carbon atoms forming the esterification product is not particularly limited. Fatty acids having 16 or more carbon atoms may be used as long as they provide esterification products that are harmless to the human body to such a degree of being used in foods.
For example, as the fatty acids having 16 or more carbon atoms, saturated fatty acids and/or unsaturated fatty acids may be used.
Examples of saturated fatty acids may include palmitic acid (hexadecanoic acid, CH₃(CH₂)₁₄COOH), margaric acid (heptadecanoic acid, CH₃(CH₂)₁₅COOH), stearic acid (octadecanoic acid, CH₃(CH₂)₁₆COOH), nonadecylic acid (nonadecanoic acid, CH₃(CH₂)₁₇COOH), and arachidic acid (eicosanoic acid, CH₃(CH₂)₁₈COOH). However, the types of available saturated fatty acids are not limited thereto.
Examples of unsaturated fatty acids may include palmitoleic acid (CH₃(CH₂)₅CH=CH(CH₂)₇COOH), oleic acid (CH₃(CH₂)₇CH=CH(CH₂)₇COOH), linoleic acid (C₁₈H₃₂O₂), and arachidonic acid (C₂₀H₃₂O₂). However, the types of available unsaturated fatty acids are not limited thereto.
The upper limit of the number of carbons of the fatty acid having 16 or more carbon atoms is not particularly limited, but may be, for example, 40 or less, 36 or less, 32 or less, 28 or less, 24 or less, or 20 or less.
In some embodiments, the fatty acid is selected from the group consisting of palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, palmitoleic acid, oleic acid, linoleic acid, and arachidonic acid.
In relation to the component (a), the type of aliphatic monohydric alcohol forming it is also not particularly limited. Aliphatic monohydric alcohols capable of providing esterification products that are harmless to the human body to such a degree of being used in foods may be used.
For example, saturated fatty alcohols or unsaturated fatty alcohols may be used, and they may have a linear or branched form.
In some embodiments, the number of carbon atoms of the aliphatic monohydric alcohol may be 1 to 40. Specifically, the number of carbon atoms of the aliphatic monohydric alcohol may be, for example, 4 or more, 8 or more, 12 or more, 16 or more, or 20 or more.
Examples of the aliphatic monohydric alcohols may include, but are not limited to, methanol, ethanol, butanol, lauryl alcohol, isotridecanol, and stearyl alcohol.
In some embodiments, the aliphatic monohydric alcohol is selected from the group consisting of methanol, ethanol, butanol, lauryl alcohol, isotridecanol, and stearyl alcohol.
In some embodiments, as the component (a), an esterification product of isotridecanol and stearic acid (e.g., isotridecyl stearate) may be used. However, the types of available component (a) are not limited thereto.
As will be described below, the content of the component (a) included in the oil may be adjusted in consideration of the function of the oil or the function of the component (a).
The component (b), i.e., an ester of sorbitan and fatty acid having 16 or more carbon atoms, is a compound that can function as a type of emulsifier, and may be a component that is harmless to the human body to such a degree of being used in foods.
Since this component (b) has both hydrophilicity and hydrophobicity due to polyhydric alcohol (i.e., sorbitan), it enables the component (a) providing lubricity to fibers to be well dispersed in water to be described below. In addition, the components (a) and (b) used together not only increase the dispersibility of the oil as described above, but also lower the melting point of the oil, thereby ensuring the handling easiness and stability of the oil. Taking these functions into consideration, the content of the component (b) may be controlled as will be described below.
In relation to the component (b), the type of fatty acid having 16 or more carbon atoms forming it is not particularly limited. Fatty acids having 16 or more carbon atoms capable of providing esterification products that are harmless to the human body to such a degree of being used in foods may be used.
For example, as the fatty acids having 16 or more carbon atoms, saturated fatty acids and/or unsaturated fatty acids may be used.
Examples of saturated fatty acids may include palmitic acid (hexadecanoic acid, CH₃(CH₂)₁₄COOH), margaric acid (heptadecanoic acid, CH₃(CH₂)₁₅COOH), stearic acid (octadecanoic acid, CH₃(CH₂)₁₆COOH), nonadecylic acid (nonadecanoic acid, CH₃(CH₂)₁₇COOH), and arachidic acid (eicosanoic acid, CH₃(CH₂)₁₈COOH). However, the types of available saturated fatty acids are not limited thereto.
Examples of unsaturated fatty acids may include palmitoleic acid (CH₃(CH₂)₅CH=CH(CH₂)₇COOH), oleic acid (CH₃(CH₂)₇CH=CH(CH₂)₇COOH), linoleic acid (C₁₈H₃₂O₂), and arachidonic acid (C₂₀H₃₂O₂). However, the types of available unsaturated fatty acids are not limited thereto.
The upper limit of the number of carbons of the fatty acid having 16 or more carbon atoms is not particularly limited, but may be, for example, 40 or less, 36 or less, 32 or less, 28 or less, 24 or less, or 20 or less.
In some embodiments, the fatty acid is selected from the group consisting of palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, palmitoleic acid, oleic acid, linoleic acid, and arachidonic acid.
In some embodiments, as the component (b), an esterification product of sorbitan and oleic acid (e.g., sorbitan monooleate) may be used. However, the type of the available component (b) is not limited thereto.
The content of the component (b) may be adjusted in consideration of the function of the component (b) and the function of the oil as described above.
For example, the oil may include 20 to 60 parts by weight of an ester esterification product (b) of sorbitan and a fatty acid having 16 or more carbon atoms with respect to 100 parts by weight of an esterification product (a) of a fatty acid having 16 or more carbon atoms and an aliphatic monohydric alcohol.
In particular, the oil of the present application may include the component (b) in a content of 25 parts by weight or more, 30 parts by weight or more, 35 parts by weight or more, 40 parts by weight or more, 45 parts by weight or more, or 50 parts by weight or more with respect to 100 parts by weight of the component (a). Further, the upper limit of the content of the component (b) with respect to 100 parts by weight of the component (a) may be, for example, 55 parts by weight or less, 50 parts by weight or less, 45 parts by weight or less, 40 parts by weight or less, 35 parts by weight or less, 30 parts by weight or less, or 25 parts by weight or less. When the above content range is satisfied, the surface of the lyocell multifilament or lyocell tow treated with the oil may have hydrophobicity.
For example, the oil may include 40 to 80 wt% of an esterification product (a) of a fatty acid having 16 or more carbon atoms and an aliphatic monohydric alcohol, based on 100 wt% of the total weight of the oil. In particular, the content of the component (a) may be 45 wt% or more, 50 wt% or more, 55 wt% or more, 60 wt% or more, or 65 wt% or more, 70 wt% or more, or 75 wt% or more, based on 100 wt% of the total weight of the oil, Further, the upper limit of the content thereof may be, for example, 75 wt% or less, 70 wt% or less, 65 wt% or less, 60 wt% or less, 55 wt% or less, 50 wt% or less, or 45 wt% or less.
For example, the oil may include an excess amount of the component (a).
For example, the oil may include 15 to 55 wt% of an esterification product (b) of sorbitan and a fatty acid having 16 or more carbon atoms, based on 100 wt% of the total weight of the oil. In particular, the content of the component (b) may be 20 wt% or more, 25 wt% or more, 30 wt% or more, 35 wt% or more, 40 wt% or more, 45 wt% or more, or 50 wt% or more, based on 100 wt% of the total weight of the oil. Further, the upper limit of the content thereof may be, for example, 50 wt% or less, 45 wt% or less, 40 wt% or less, 35 wt% or less, 30 wt% or less, or 25 wt% or less.
For example, the oil may further include water. A small amount of water may help emulsification. In this specification, "oil treatment (oil-treated)" and "emulsification (emulsified)" may be used interchangeably.
The content of water is not particularly limited, but water may be included in the amount remaining after excluding the total content of components (a) and (b) from 100 wt% of the entire oil. The content of water in the oil (i.e., the remaining amount excluding the total content of the remaining components excluding water) may be, for example, 10 wt% or less, 9 wt% or less, 8 wt% or less, 7 wt% or less, 6 wt% or less, 5 wt% or less, 4 wt% or less, 3 wt% or less, 2 wt% or less, or 1 wt% or less. Further, the lower limit thereof may be, for example, 0 wt% or more, 0.1 wt% or more, 0.5 wt% or more, or 1 wt% or more.

[Method of manufacturing lyocell material]

This application relates to a method of manufacturing a lyocell material. By this method, a lyocell material may be manufactured, and this lyocell may be used in smoking articles.
In particular, the method of manufacturing a lyocell material includes a lyocell dope spinning process; a coagulation and multifilament obtainment process; a washing process; an oil treatment process; and a crimp application process. Further, the method of manufacturing a lyocell material may further include a binder treatment process; and other processes.
The oil treatment process may be performed before the crimp application process, after the crimp application process, or before and after the crimp application process.
The oil treatment may be performed independently, for example, by spraying an oil of the above-described composition onto lyocell multifilaments or by immersing the lyocell multifilaments in the oil. As described above, the oil treatment may be performed so that the content (e.g., OPU (wt%)) of the oil in the lyocell material satisfies a preset range.
The crimp application process may be performed, for example, by applying steam and/or pressure to the lyocell multifilaments.
A method of manufacturing a lyocell material according to a specific embodiment of the present application, including an oil treatment process and a crimp application process, will be described in more detail below. The method of the present application may be performed by including one or more of the processes to be described below.

<(a) Lyocell dope spinning process>

This process is a process of spinning a lyocell spinning dope including lyocell cellulose (or cellulose pulp) and N-methylmorpholine-N-oxide (NMMO).
Commercially available cellulose acetate filters are pointed out as a major cause of microplastics. However, just as an amine oxide solvent used in the production of lyocell fibers is recyclable and is biodegradable even when it is discarded, a lyocell material does not generate any pollutants during its production process. Furthermore, since a lyocell tow is biodegraded within a relatively short period of time and is removed, lyocell is a more environmentally friendly material than cellulose acetate.
For example, the content of cellulose in the spinning dope may be 5 to 15 wt% based on 100 wt% of the total weight of the lyocell dope. When the content of cellulose is too small, it is difficult to implement the characteristics of lyocell fibers, and when the content of cellulose exceeds the above range, it is difficult to dissolve in a solvent. Considering this, the content of cellulose 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, based on 100 wt% of the total weight of the lyocell dope, 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, based on 100 wt% of the total weight of the lyocell dope.
For example, the spinning dope may include an aqueous solution of N-methylmorpholine-N-oxide (NMMO). Taking into consideration degree of dissolution of cellulose and process temperature, 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.
For example, the content of alpha-cellulose in the cellulose or cellulose pulp may be 85 to 97 wt% with respect to 100 wt% of the total cellulose and/or cellulose pulp.
For example, the content of hemicellulose in the cellulose or cellulose pulp may be 1 wt% to 15 wt% with respect to 100 wt% of the total cellulose and/or cellulose pulp. By controlling the content of hemicellulose within the above range, stable physical properties (e.g., hardness or suction resistance implementation) and processability of the lyocell material can be more easily secured.
Additionally, in some embodiments, the degree of polymerization (DPw) of the cellulose may be 600 to 1700. In some embodiments, the degree of polymerization of the cellulose refers to the number of repeating units and/or monomers of cellulose, alpha-cellulose and/or hemicellulose in the cellulose or cellulose pulp.
In the spinning process, the shape of a spinneret for discharging the spinning dope is not particularly limited. For example, a donut-shaped spinneret may be used.
The nozzle temperature, particularly, spinning temperature of a spinneret may be appropriately selected by those skilled in the art. Considering that the viscosity of the spinning dope may vary depending on the spinning temperature to result in poor discharging, the spinning temperature may be, for example, 100°C or lower to 120°C or lower, or 100°C or lower to 110°C or lower.
For example, the process of spinning the spinning dope may be performed under controlled spinning conditions so that the single fineness of a filament is 1.67 dtex to 8.89 dtex (1.5 denier to 8.0 denier) or less. For example, at least one spinning condition of the discharge amount and spinning speed of the spinning dope may be appropriately controlled so that the single fineness of the filament included in the lyocell material satisfies 1.67 to 8.89 dtex (1.5 to 8.0 denier). In this case, the single fineness of a filament refers to the fineness of a single monofilament separated from a multifilament.
In particular, the single fineness of the filament may be, for example, 8.33 dtex (7.5 denier) or less, 7.78 dtex (7.0 denier) or less, 7.22 dtex (6.5 denier) or less, 6.67 dtex (6.0 denier) or less, 6.11 dtex (5.5 denier) or less, 5.56 dtex (5.0 denier) or less, 5.00 dtex (4.5 denier) or less, 3.89 dtex (3.5 denier) or less, 3.33 dtex (3.0 denier) or less, 2.78 dtex (2.5 denier) or less, or 2.22 dtex (2.0 denier) or less. Additionally, the lower limit therof may be, for example, 2.22 dtex (2.0 denier) or more, 2.78 dtex (2.5 denier) or more, 3.33 dtex (3.0 denier) or more, 3.89 dtex (3.5 denier) or more, 4.44 dtex (4.0 denier) or more, 5.00 dtex (4.5 denier) or more, 5.56 dtex (5.0 denier) or more, 6.11 dtex (5.5 denier) or more, 6.67 dtex (6.0 denier) or more, 7.22 dtex (6.5 denier) or more, or 7.78 dtex (7.0 denier) or more. When the above range is satisfied, it may be more advantageous in implementing the stable draw resistance of a filter for smoking articles and ensuring the processibility of a filter for smoking articles.
The spinning dope discharged through the spinneret may undergo a coagulating process to be described later.

<(b) Coagulation and multifilament obtainment process>

In this process, the spun lyocell spinning dope is coagulated, and lyocell multifilaments may be obtained.
For the coagulation, a method in which the spinning dope comes into contact with air and/or a coagulation liquid may be used.
For example, the coagulation may include a first coagulation process of supplying cooling air to the spun lyocell dope; and a second coagulation process of coagulating the first-coagulated spinning dope by adding the same to a coagulation liquid.
According to the coagulation method, the lyocell dope discharged from the spinneret may be first coagulated in the space (air gap section) between the spinneret and a coagulation tank. This air gap section may be supplied with cooling air from an air-cooling unit located inside the spinneret to the inside to outside of the spinneret. In addition, the first coagulation may be achieved by the so-called air quenching method or means known in the related field.
For example, the upper temperature limit of the cooling air used for the first coagulation may be, for example, 15 °C or less. In particular, 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 or less. When the temperature is exceeded, the coagulation of the spinning dope by air may not be sufficient, and the spinning-related processability may not be good.
The lower temperature limit of the cooling air may be determined in consideration of spinning processability and/or cross-sectional uniformity of a filament. For example, when the temperature of the cooling air is lower than 4°C, the surface of the spinneret may cool, the surface of the filament may become uneven, and the spinning processability may also deteriorate. In consideration of this, the temperature of the cooling air may be 5 °C or more, 6 °C or more, 7 °C or more, 8 °C or more, or 9 °C or more.
The degree to which the cooling air is supplied may be controlled in consideration of sufficient coagulation, spinning processability, and influence on the physical properties of the filament. For example, the cooling air may be supplied to the discharged spinning dope at an air flow rate of 70 to 400 Nm³/h. In particular, the air flow rate may be 100 Nm³/h or more, 150 Nm³/h or more, 200 Nm³/h or more or 250 Nm³/h or more, and the upper limit of the air flow rate can be, for example, 350 Nm³/h or less, 300 Nm³/h or less, 250 Nm³/h or less, 200 Nm³/h or less or 150 Nm³/h or less.
After the first coagulation process, the cooled spinning dope may be supplied to a coagulation tank or bath containing a coagulation liquid (second coagulation process). For appropriate coagulation to proceed, the temperature of the coagulation liquid may be, for example, 30 °C or less or 25 °C or less. Additionally, the temperature of the coagulation liquid may be 10 °C or more, 15 °C or more, or 20 °C or more. When the temperature is maintained, a coagulation rate may be appropriately maintained.
The type of the coagulation liquid for the second coagulation as described above is not particularly limited. For example, the coagulation liquid may include at least one of water and N-methylmorpholine-N-oxide (NMMO).
Although not particularly limited, when the coagulation liquid includes water and NMMO, based on 100 wt% of the total weight of the coagulation liquid, the content of water in the coagulation liquid may be 60 to 90 wt%, and the content of NMMO in the coagulation liquid may be 10 to 40 wt%. Alternatively, the coagulation liquid may include 70 to 80 wt% of water and 20 to 30 wt% of NMMO based on 100 wt% of the total weight of the coagulation liquid. The concentration of this coagulation liquid may be controlled to be maintained during the manufacturing process using sensors, etc.

<(c) Washing process>

If necessary, the lyocell multifilament may be washed after the above-described coagulation and obtaining multifilament process. NMMO and/or other impurities remaining in the filament may be removed by this washing.
The method of performing the washing is not particularly limited. For example, the washing may be performed by introducing the coagulated lyocell multifilaments into a washing tank using a towing roller. Alternatively, the washing may be performed by spraying a washing liquid during the procedure of moving to the next process by a towing roller.
The washing process includes two or more washing tanks, each of which independently includes a washing liquid, and temperatures of the washing liquids are independent of each other and at least two of the temperatures may be different from each other. In some embodiments, the processes are performed in the mentioned order.
In some embodiments, in the method of manufacturing a lyocell material, the washing process may include use of two or more washing tanks, each of which independently includes a washing liquid, and temperatures of the washing liquids may be each independently 25 °C to 100 °C. Preferably, the upper limit of the temperature of the washing liquid may be 95 °C, 90 °C, 85 °C, 80 °C, 75 °C, 70 °C, 65 °C, or 60 °C, and the lower limit of the temperature of the washing liquid may be 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, or 80 °C.
In some embodiments, in the method of manufacturing a lyocell material, at least two of the washing liquids may have different temperatures. Since the temperatures of the washing liquids are different, the extraction of NMMO may be performed continuously at relatively low temperatures and relatively high temperatures, and the content of NMMO included in the lyocell material may be further reduced.
In some embodiments, in the method of manufacturing a lyocell material, when the washing tank in which lyocell multifilaments are washed first is referred to as a first washing tank, the washing liquid included in the first washing tank is referred to as a first washing liquid, the washing tank in which lyocell multifilaments are washed last is referred to as an n-th washing tank, and the washing liquid included in the n-th washing tank is referred to as an n-th washing liquid, the temperature of the first washing liquid may be lower than the temperature of the n-th washing liquid (where n is a natural number of 2 or more). For example, when the washing tank in which the lyocell multifilament is washed for the last time is called the second washing tank, the temperature of the first washing liquid may be lower than the temperature of the second washing liquid.
In some embodiments, in the method of manufacturing a lyocell material, the n-th washing tank may be a tenth washing tank, and preferably, the n-th washing tank may be a third washing tank.
Although not particularly limited, the number of washing tanks through which one coagulated lyocell multifilament is transported in the washing process may be 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, 3 or less, or 2 or less, and may be 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, or 9 or more.
In some embodiments, in the method of manufacturing a lyocell material, each of the washing tanks may be heated. As a result, the washing liquid included in each washing tank may be heated, and maintained at a high temperature.
In some embodiments, in the method of manufacturing a lyocell material, the temperature of the first washing liquid may be less than 80°C. When the temperature of the first washing liquid is 80°C or more, the initial coagulation of the lyocell multifilament may be inhibited, thus resulting in a decrease in the crystallinity of the lyocell multifilament. As a result of a decrease in crystallinity, the solidification of the lyocell multifilament may not be sufficiently achieved, and the physical properties (e.g., strength) of the lyocell multifilament may not be sufficiently developed. Additionally, viscosity as a dope may be maintained due to lack of initial coagulation. As a result, problems of fiber bonding and/or sticking to a roller or fiber winding on the roller may occur as the fiber advances, and the manufacturing of lyocell material may be restricted.
In some embodiments, in the method of manufacturing a lyocell material, the washing process may further include use of one or more sprayers, and the washing of the lyocell multifilaments may be performed by the spraying of the sprayers. The number of sprayers is not particularly limited, and may be, for example, two.
In particular, the sprayer may spray one or more of the washing liquids.
Preferably, the sprayer may spray the first washing liquid. The first washing liquid may be supplied from the first washing tank to the sprayer through a pipe.
In some embodiments, in the method of manufacturing a lyocell material, the sprayer may be mounted over the first washing tank. Thereby, the first washing liquid sprayed by the sprayer may be included in the first washing tank again. Additionally, the washing process in the first washing tank and the washing process in the second washing tank may be performed by different mechanisms. Alternatively, the washing process in the first washing tank and the washing process in the second washing tank may be performed by the same mechanism.
In some embodiments, in the method of manufacturing a lyocell material, the sprayer sprays the first washing liquid, the first washing liquid is supplied from the first washing tank to the sprayer through a pipe, and the sprayer is mounted over the first washing tank, so that the first washing liquid sprayed by the sprayer may be included in the first washing tank again.
In some embodiments, in the method of manufacturing a lyocell material, the washing process may further include use of at least one dehydrator, by which the washing liquid may be extracted from the lyocell multifilament. The number of dehydrators is not particularly limited, and may be, for example, two.
In some embodiments, in the method of manufacturing a lyocell material, the dehydrator may be mounted over at least one washing tank. Preferably, the dehydrator may be mounted over the first washing tank. In some embodiments, the dehydrator may be mounted over the first washing tank mounted with the sprayer. Thereby, the lyocell multifilaments in the first washing tank alternately experience the spraying by the sprayer and the dehydration by the dehydrator, and the extraction efficiency of NMMO from the lyocell multifilaments may be increased.
Additionally, the dehydrator may move close to the progressing lyocell multifilaments to suck and remove the washing liquid present on the surface and inside of the lyocell multifilaments. In particular, the suction power of the dehydrator or the air pressure provided to the dehydrator is not particularly limited, but may be 9.81 N/cm² to 147.10 N/cm² (1 kgf/cm² to 15 kgf/cm²).
The components of the washing liquid is not particularly limited. For example, the washing liquid may include water, and preferably, may further include one or more known additives.
In some embodiments, the washing solution further includes water and one or more known additives.
In addition, in consideration of reuse after washing, etc., the washing liquid may be used at a temperature of 100 °C or lower.
In some embodiments, in the method of manufacturing a lyocell material, the washing process includes use of one or more of the above-described sprayers and use of one or more of the above-described dehydrators.
In some embodiments, in the method of manufacturing a lyocell material, the washing process includes use of one or more of the above-described sprayers and use of one or more of the above-described dehydrators mounted over one or more of the washing tanks.

<(d) Oil treatment process>

If necessary, a process of treating the lyocell multifilaments with an oil may be performed. This process is a process of applying the above-described oil to the surface of a filament. Through the oil treatment, friction applied to the filament may be reduced, and crimps may be formed well in the crimp application process to be described later. When the oil treatment is performed twice or more as described below, it may be called first oil treatment and second oil treatment depending on the order.
Although not particularly limited, the oil treatment may be performed by immersing the lyocell multifilament in a bath filled with the oil so that the lyocell multifilaments are completely immersed in the oil. Alternatively, the oil may be treated by spraying an oil liquid during the procedure of moving to the next process by a towing roller.
In order to ensure that the amount of the oil applied to the lyocell multifilament after the oil treatment as described above is constant, an additional process may be performed in which a roll or the like positioned before and/or after the oil treatment process squeezes out the oil from the surface of the lyocell multifilament.
For example, the oil treatment may be performed such that the content of the oil (OPU: oil pick up ratio (weight %)) is 1.0 weight % or more based on 100 wt % of the at least oil-treated lyocell multifilament. In this case, the at least oil-treated lyocell multifilament may be, for example, a lyocell multifilament to which first oil treatment has been applied, a lyocell multifilament to which first oil treatment and second oil treatment (refer to the description below) have been applied, or a lyocell multifilament to which a binder to be described below has been applied together with the above-described oil treatment. Additionally, the lyocell multifilament treated with an oil and/or a binder as described above may be a lyocell multifilament to which crimps are applied.
In particular, the content of the oil in the at least oil-treated lyocell multifilament may be 0.5 wt% or more, 1.0 wt% or more, 1.5 wt% or more, 2.0 wt% or more, 2.5 wt% or more, 3.0 wt% or more, particularly 3.5 wt% or more, 4.0 wt% or more, 4.2 wt% or more, 4.5 wt% or more, 5.0 wt% or more, 5.5 wt% or more, 6.0 wt% or more, 6.5 wt% or more, 7.0 wt% or more, 7.5 wt% or more, 8.0 wt% or more, 8.5 wt% or more, 9.0 wt% or more or 9.5 wt% or more, based on 100 wt% of the total weight of the at least oil-treated lyocell multifilament. Further, the upper limit thereof may be, for example, 20.0 wt% or less, 18.0 wt% or less, 17.0 wt% or less, 16.0 wt% or less, 15.0 wt% or less, 14.5 wt% or less, 14.0 wt% or less, 13.5 wt% or less, 13.0 wt% or less, 12.5 wt% or less, 12.0 wt% or less, 11.5 wt% or less, 11.0 wt% or less, 10.5 wt% or less, 10 wt% or less, 9.5 wt% or less, 9.0 wt% or less, 8.5 wt% or less, 8.0 wt% or less, 7.8 wt% or less, or 7.6 wt% or less, based on 100 wt% of the total weight of the at least oil-treated lyocell multifilament. In this case, the above content may refer to a dry weight after a solvent (e.g., water) or liquid component that may be included in the oil has evaporated.
When the above-described oil is treated within the above content range, the hydrophilic properties of the lyocell material can be supplemented.
In some cases, drying of the oil may be performed after the above-described oil treatment.
In specific embodiments of the present application, one or more of the above-described processes may be controlled so that the single fineness of filaments forming the lyocell multifilament may be 1.67 to 8.89 dtex (1.5 to 8.0 denier). The single fineness of the filament refers to a fineness of a single monofilament separated from a multifilament.
Specifically, the single fineness of the filament may be, for example, 8.33 dtex (7.5 denier) or less, 7.78 dtex (7.0 denier) or less, 7.22 dtex (6.5 denier) or less, 6.67 dtex (6.0 denier) or less, 6.11 dtex (5.5 denier) or less, 5.56 dtex (5.0 denier) or less, 5.00 dtex (4.5 denier) or less, 3.89 dtex (3.5 denier) or less, 3.33 dtex (3.0 denier) or less, 2.78 dtex (2.5 denier) or less, or 2.22 dtex (2.0 denier) or less. Further, the lower limit thereof may be, for example, 2.22 dtex (2.0 denier) or more, 2.78 dtex (2.5 denier) or more, 3.33 dtex (3.0 denier) or more, 3.89 dtex (3.5 denier) or more, 4.44 dtex (4.0 denier) or more, 5.00 dtex (4.5 denier) or more, 5.56 dtex (5.0 denier) or more, 6.11 dtex (5.5 denier) or more, 6.67 dtex (6.0 denier) or more, 7.22 dtex (6.5 denier) or more, or 7.78 dtex (7.0 denier) or more. Satisfying the above range may be more advantageous in implementing stable draw resistance of a filter for smoking articles and ensuring processability of a filter for smoking articles.
Although not particularly limited, the process controlled to ensure the above-described single fineness range may be the above-described spinning process. Alternatively, the above-described spinning, coagulation, washing and oil treatment processes may all be controlled to ensure the above-described single fineness range.

<(e) Crimp application process>

The crimp application process is a process of applying pressure to the oil-treated lyocell multifilament through steam and/or a press roller to obtain a crimped multifilament, preferably, a crimped tow. The crimp application process may be referred to as a crimping process.
Through the crimping, lyocell multifilaments may be imparted with waves, and fibers may have bulky characteristics. The crimping may be performed using a known crimping device, such as one including a stuffer box and/or a steam box, and the usable crimping device is not particularly limited as long as it is a device capable of applying one or more of the pressures to be described below.
For example, the crimp application process may be performed by first supplying steam to the lyocell multifilament to preheat and swell the lyocell multifilament and then pressing the lyocell multifilament with a press roller to form wrinkles in the lyocell multifilament. In this case, a steam box may be used for steam supply, and this steam box may be located at the front end of the crimping device.
For example, the crimp application process may be performed in a manner in which pressurization of the lyocell multifilament by a press roller and steam supply are performed simultaneously.
For example, the crimp application process may be performed by first supplying steam to the lyocell multifilament to preheat and swell the lyocell multifilament and then simultaneously applying pressure and steam to the lyocell multifilament by a press roller.
For example, the crimp application process may be performed by applying steam of 0.98 to 19.61 N/cm² (0.1 to 2.0 kgf/cm²) to the lyocell multifilament before introducing it into the crimping device (for example, press roller).
For example, steam of 1.96 N/cm² (0.2 kgf/cm²) or more, 2.94 N/cm² (0.3 kgf/cm²) or more, 3.92 N/cm² (0.4 kgf/cm²) or more, 4.90 N/cm² (0.5 kgf/cm²) or more or 5.88 N/cm² (0.6 kgf/cm²) or more may be supplied by the steam box. Additionally, steam of 14.71 N/cm² (1.5 kgf/cm²) or less, 13.73 N/cm² (1.4 kgf/cm²) or less, 12.75 N/cm² (1.3 kgf/cm²) or less, 11.77 N/cm² (1.2 kgf/cm²) or less, 10.79 N/cm² (1.1 kgf/cm²) or less, or 9.81 N/cm² (1.0 kgf/cm²) or less may be supplied. When the steam supply or pressure is below the above range, crimps may not be formed easily. In addition, when the steam supply or pressure exceeds the above range, the flexibility of the filament increases to apply excessive crimps within the crimping device, and thus the filament may not pass through the crimping device.
For example, the crimp application process may be performed by pressing the lyocell multifilament with a press roller to form wrinkles in the lyocell multifilament. Additionally, steam supply may not be performed prior to pressurization, steam supply may not be performed simultaneously with pressurization, or steam supply may not be performed both prior to pressurization and simultaneously with pressurization.
For example, the crimp application process may be performed by applying a pressure of 14.71 to 39.23 N/cm² (1.5 to 4.0 kgf/cm²) to the lyocell multifilament introduced into the crimping device using a press roller.
For example, a pressure of 15.69 N/cm²(1.6 kgf/cm²) or more, 16.67 N/cm²(1.7 kgf/cm²) or more, 17.65 N/cm²(1.8 kgf/cm²) or more, 18.63 N/cm²(1.9 kgf/cm²) or more, 19.61 N/cm²(2.0 kgf/cm²) or more, 20.60 N/cm²(2.1 kgf/cm²) or more, 21.58 N/cm²(2.2 kgf/cm²) or more, 22.56 N/cm²(2.3 kgf/cm²) or more, 23.54 N/cm²(2.4 kgf/cm²) or more, or 24.52 N/cm²(2.5 kgf/cm²) or more may be applied to the lyocell multifilament through the press roller. Additionally, 38.25 N/cm²(3.9 kgf/cm²) or less, 37.27 N/cm²(3.8 kgf/cm²) or less, 36.29 N/cm²(3.7 kgf/cm²) or less, 35.31 N/cm²(3.6 kgf/cm²) or less, 34.33 N/cm²(3.5 kgf/cm²) or less, 33.35 N/cm²(3.4 kgf/cm²) or less, 32.37 N/cm²(3.3 kgf/cm²) or less, 31.39 N/cm²(3.2 kgf/cm²) or less, 30.41 N/cm²(3.1 kgf/cm²) or less, 29.42 N/cm²(3.0 kgf/cm²) or less, 28.44 N/cm²(2.9 kgf/cm²) Below, a pressure of 27.46 N/cm² (2.8 kgf/cm²) or less, 26.48 N/cm² (2.7 kgf/cm²) or less, 25.50 N/cm² (2.6 kgf/cm²) or less, or 24.52 N/cm² (2.5 kgf/cm²) or less may be applied by the press roller.
When the pressure of the press roller is below the above range, the desired number of crimps may not be formed sufficiently. Additionally, when the pressure of the press roller exceeds the above range, pressing force may be too strong, so that the filament may not be smoothly introduced into the crimping device or may not pass through the crimping device (for example, stuffer box). Wrinkles may be formed in the lyocell multifilament by the press roller providing the above pressure.
For example, a pressure of 0.98 to 19.61 N/cm² (0.1 to 2 kgf/cm²) may be applied to the lyocell multifilament using an upper plate. Additionally, the upper plate may apply pressure to the lyocell multifilament when the lyocell multifilament passes through the press roller or is passing through the press roller.
For example, the pressure applied by the upper plate may be 1.96 N/cm² (0.2 kgf/cm²) or more, 2.94 N/cm² (0.3 kgf/cm²) or more, 3.92 N/cm² (0.4 kgf/cm²) or more, or 4.90 N/cm² (0.5 kgf/cm²) or more. Additionally, a pressure of 14.71 N/cm² (1.5 kgf/cm²) or less, 13.73 N/cm² (1.4 kgf/cm²) or less, 12.75 N/cm² (1.3 kgf/cm²) or less, 11.77 N/cm² (1.2 kgf/cm²) or less, 10.79 N/cm² (1.1 kgf/cm²) or less, or 9.81 N/cm² (1.0 kgf/cm²) or less may be applied by the upper plate.
Furthermore, when the pressure of the upper plate, serving to move up and down to provide uniform crimps after passing through the press roller, is less than 0.98 N/cm² (0.1 kgf/cm²), the upper plate cannot be fixed due to the pressure inside the crimping device (for example, stuffer box), thereby causing the tow to stay in the crimping device (for example, stuffer box) for a long time to prevent the continuity of a process from being maintained. When the pressure of the upper plate exceeds 19.61 N/cm² (2 kgf/cm²), steam cannot be easily discharged inside the crimping device (for example, stuffer box), thereby causing the shape of crimps to become irregular.
For example, in the crimp application process, a doctor blade applying a preset pressure to the lyocell multifilament may be used. The doctor blade controls the residence time of the filaments introduced into the crimping device (for example, stuffer box), thereby contributing to the control of the number of crimps. This doctor blade may be located in the path of the lyocell multifilament pressed by the roller and then discharged at the roller pressure point.
For example, the crimp application process may be performed by applying a pressure of 0.98 to 19.61 N/cm² (0.1 to 2.0 kgf/cm²) to the lyocell multifilament passing through the roller of the crimping device using the doctor blade.
For example, the pressure applied by the doctor blade may be 1.96 N/cm² (0.2 kgf/cm²) or more, 2.94 N/cm² (0.3 kgf/cm²) or more, 3.92 N/cm² (0.4 kgf/cm²) or more, or 4.90 N/cm² (0.5 kgf/cm²) or more. Additionally, a pressure of 14.71 N/cm² (1.5 kgf/cm²) or less, 13.73 N/cm² (1.4 kgf/cm²) or less, 12.75 N/cm² (1.3 kgf/cm²) or less, 11.77 N/cm² (1.2 kgf/cm²) or less, 10.79 N/cm² (1.1 kgf/cm²) or less, or 9.81 N/cm² (1.0 kgf/cm²) or less may be applied by the doctor blade.
For example, the crimp application process may be performed at a temperature in the range of 120°C to 250°C. When the temperature is too low, the shape stabilization effect of crimps is not good, and when the temperature is too high, the concentration of oil in the crimping device (for example, stuffer box) increases, thus making it difficult to form crimps. Therefore, considering the above-described steam pressure or the like, the temperature may be appropriately controlled in 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.

<(f) Binder treatment process>

For example, the method may further include a process of treating the oil-treated lyocell multifilamet or the lyocell multifilament obtained by the crimp application process with a binder.
When a filter for smoking articles is manufactured using a lyocell material (e.g., lyocell tow), a binder may be used additionally. The binder may increase the hardness of a filter for smoking articles including a lyocell material, thereby preventing a filter from being caught during a filter manufacturing process or a cigarette manufacturing process.
A method of coating a lyocell material with a binder is not particularly limited. For example, the oil treatment may be carried out by immersing the lyocell multifilaments in a bath filled with a binder and/or a binder solution so that the lyocell multifilaments are completely immersed in the binder. Alternatively, binder coating on the lyocell multifilament may be achieved by injecting and/or spraying a binder and/or a binder solution through a nozzle.
Since the types and components of available binders are as described above, a detailed description thereof will be omitted.
For example, the binder and/or binder solution may further include a solvent in addition to the above-described components. Examples of the solvent may include, but are not limited to, water, ethanol, propylene glycol, and/or glycerin. When the binder and/or binder solution includes a solvent, the content of the solvent may be, for example, about 20 to 80 wt% or about 40 to 60 wt% based on 100 wt% of the total weight of the binder and/or binder solution.
The binder treatment may be performed at a level that can achieve the purpose of the above-described binder treatment. For example, the binder treatment may be performed so that the content of the binder satisfies a range of 20 wt% or less, for example, 8 to 15 wt%, based on 100 wt% of the oil and binder-treated lyocell multifilament. In this case, the content may refer to a dry weight after the solvent or liquid component that may be included in the binder has evaporated.
After the lyocell multifilament is coated with the binder, drying of the binder may proceed. Although drying temperature is not particularly limited, for example, drying may be performed at room temperature (about 10 °C to 35 °C).

<(g) Other processes>

After crimp application, appropriate post-treatment may be additionally performed.
For example, second oil treatment (g1) may be additionally performed. The second oil treatment may provide more flexibility to a lyocell multifilament (for example, lyocell tow). The second oil treatment may be performed in the same manner as or in accordance with (d) the above-described oil treatment process.
In particular, the second oil treatment may be performed by applying an oil to the lyocell multifilament (for example, lyocell tow) that has undergone a process using a crimper. This treatment may be advantageously utilized in various processes performed during the manufacturing of filters for smoking articles. For example, the second oil treatment may allow fibers and filters to be easily spread by air during a spreading process, while also restricting the breakage of fibers during a stretching process.
The above-described second oil treatment may be performed before or after the binder treatment. Alternatively, the second oil treatment may be performed regardless of the binder treatment.
Even in cases where the above-described second oil treatment is performed, a second oil treatment process may be performed so that the content of oil or OPU in the material satisfies the above-described range.
For example, drying treatment (g2) may be performed additionally. The drying may be carried out, for example, at a temperature ranging from 100 °C to 130 °C. The drying treatment method or process is not particularly limited, and known technologies may be used. For example, this drying treatment may be achieved by applying hot air to the lyocell multifilament (for example, lyocell tow) or passing the tow through or leaving the tow in a temperature-controlled room for a certain period of time.
The lyocell material according to the present disclosure may be obtained by the above-described method of manufacturing a lyocell material.
The lyocell material according to the present disclosure may be a material capable of being obtained by the above-described method of manufacturing a lyocell material.

[Smoking articles]

Although not particularly limited, the lyocell material manufactured by the above method may be included in a smoking article. Smoking articles may be aerosol-generating articles. An aerosol-generating article may include an aerosol-generating material or an aerosol-forming substrate.
For example, a lyocell material may be included in a combustible cigarette. As another example, the lyocell material may be included in a heating cigarette, and the heating cigarette may be used in conjunction with an aerosol generating device.
For example, when a smoking article is used as a heating smoking article, the smoking article may be inserted separately into the aerosol generating device. Here, the aerosol generating device includes a receiving groove capable of receiving an aerosol generating article, and, in addition, may include a heater for heating the aerosol generating article so as to generate an aerosol, a control unit for generally controlling the operation of the aerosol generating device, a battery for providing power used for operating the aerosol generating device, and a detector for recognizing that the aerosol generating article has been inserted into the aerosol generating device.
The smoking article may include a tobacco medium unit, a filter for the smoking article, and a wrapper, wherein the filter for the smoking article may be located at one end of the tobacco medium unit, for example at the rear end or front end of the tobacco medium unit. The tobacco medium unit and the filter for the smoking article may each include a single segment, or may each independently include a plurality of segments.
The tobacco medium unit includes a tobacco material, and the tobacco material includes nicotine. In addition, the tobacco medium unit may additionally include one or more excipients.
The excipients may include a binder, a filler, and other additives. For example, a tobacco medium included in the tobacco medium unit may be manufactured in the form of granules including a tobacco material, an excipient, etc.
For example, a filler may be additionally included to maintain the shape, strength and mass of the tobacco medium unit constant. For example, the lyocell material may be included in the tobacco medium unit. Additionally, the lyocell material may be used as a filler.
The wrapper may be subdivided into a cigarette paper wrapping the tobacco medium unit, a filter paper wrapping the filter, and a tipping wrapper combining the tobacco medium unit and the filter.

[Filter for smoking articles]

A lyocell material may be used in a filter for smoking articles. The lyocell material may be a lyocell tow. For example, the lyocell tow includes a lyocell multifilament to which crimps are applied.
For example, the present application relates to a filter for smoking articles. The filter for smoking article includes a lyocell material, and the lyocell material may be the same as that described above. Additionally, the filter for smoking articles may include a lyocell tow, and the lyocell tow may be the same as that described above.
In addition, the lyocell material includes the oil in an amount of 0.1 wt% or more with respect to 100 wt% of the total weight of the lyocell material. Besides, the description of the oil component and content according to some embodiments is the same as those described above.
For example, the single fineness of filaments forming the lyocell multifilament may be 1.67 to 8.89 dtex (1.5 to 8.0 denier). Specific figures are the same as those described above.
For example, the lyocell multifilament to which crimps are applied may be a lyocell material having a total fineness of 1,667 to 6,111 tex (15,000 to 55,000 denier), and, preferably, may be a lyocell tow. Specific figures are the same as those described above.
For example, the lyocell multifilament to which crimps are applied may have crimps of 3.94 to 23.62 per centimeter (10 to 60 per inch). Specific figures are the same as those described above.
For example, the filter for smoking articles may further include a binder on the surface of the lyocell multifilament to which crimps are applied or between the lyocell multifilament to which crimps are applied. The binder may increase the hardness of a filter for smoking articles manufactured from tow, thereby preventing a filter from being caught during a filter manufacturing process or a cigarette manufacturing process. The description of the types, components and contents of available binders is the same as those described above.
For example, the filter for smoking articles may further include a wrapper (referred to as wrapper paper, filter paper or filter wrapper). For example, the wrapper may be a porous paper or non-porous paper capable of wrapping the above-described lyocell tow and maintaining the shape of a filter (e.g., a column or cylinder).
In some embodiments, the filter for smoking articles may have a preset shape and size.
For example, the filter may have a rod shape. In particular, the filter for smoking articles may have a cylindrical shape.
Additionally, the filter may have a length of, for example, 10 mm to 50 mm. In particular, the length 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, 35 mm or more, 40 mm or more, or 45 mm or more, and may have 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.
In some embodiments, the filter having the above length may have a circular cross-section, and the circular cross-section may be a circumference of 10 mm 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 may have 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.
For example, the filter for smoking articles may include a lyocell tow and a filter wrapper. Since the description of the lyocell tow and the filter wrapper is the same as that described above, it will be omitted.
The wrapper may be a porous paper or non-porous paper capable of wrapping the above-described lyocell tow and maintaining the shape of a filter (e.g., a column or cylinder).
For example, when a porous wrapper is used, the wrapper may have a porosity of 10 to 50,000 CU (Coresta Unit). Coresta Unit may be defined as a volume flow rate (cm³min^-1) of air passing through 1 cm² of a substrate sample (i.e. porous wrapper) at a pressure difference of 1 kPa. In particular, the lower limit of the porosity of the wrapper may be, for example, 1000 CU or more, 5000 CU or more, 10000 CU or more, 15000 CU or more, 20000 CU or more, 25000 CU or more, 30000 CU or more, 35000 CU or more, 40000 CU or more, or 45000 CU or more, and the upper limit thereof may be, for example, 45000 CU or less, 40000 CU or less, 35000 CU or less, 30000 CU or less, 25000 CU or less, or 20000 CU or less. In some embodiments, the wrapper may have a porosity within a range of 22,000 to 26,000 CU or 23,000 to 25,000 CU.
For example, the basis weight of the wrapper may be 15 to 60 g/cm². In particular, the lower limit of the basis weight of the wrapper may be, for example, 20 g/cm² or more, 25 g/cm² or more, 30 g/cm² or more, 35 g/cm² or more, 40 g/cm² or more, 45 g/cm² or more, 50 g/cm² or more, or 55 g/cm² or more, and the upper limit thereof may be, for example, 55 g/cm² or less, 50 g/cm² or less, 45 g/cm² or less, 40 g/cm² or less, 35 g/cm² or less, 30 g/cm² or less, 25 g/cm² or less, or 20 g/cm² or less. In some embodiments, the wrapper may have a basis weight of 16 g/cm² or more, 17 g/cm² or more, 18 g/cm² or more, 19 g/cm² or more, 20 g/cm² or more, or 21 g/cm² or more, and 25 g/cm² or less, 24 g/cm² or less, 23 g/cm² or less, 22 g/cm² or less, or 21 g/cm² or less.
Although not particularly limited, the weight of the rod-shaped filter may be 50 mg or more. In particular, the weight of the filter may have, for example, a lower limit of 100 mg or more, 150 mg or more, or 200 mg or more, and may have an upper limit of 500 mg or less, 450 mg or less, 400 mg or less, 350 mg or less, 300 mg or less, 250 mg or less, or 200 mg or less.
Since descriptions of other filters for smoking articles and materials included therein are the same as those described above, they will be omitted.

[Method of manufacturing filter for smoking articles]

For example, the present application relates to a method of manufacturing a filter for smoking articles. This method is a method of manufacturing the above-described filter for lyocell smoking articles, and may be a method including a method of manufacturing the above-described lyocell material.
With regard to the method of manufacturing a filter for smoking articles, residual processes except for the process of manufacturing the filter are the same as those described for the above-described lyocell material, and therefore, a description thereof will be omitted. In addition, any description that overlaps with those described above will also be omitted.
The process of manufacturing a filter may be appropriately performed by those skilled in the art according to a known method. For example, a filter may be manufactured by forming a wrapper filled with a lyocell material into a rod shape. Alternatively, a filter may be manufactured by cutting a filter paper filled with a lyocell material having a rod shape to an appropriate length. A description of the wrapper is as the same as that described above.
Although not particularly limited, prior to filling a filter paper with a lyocell material, opening of the lyocell material or treatment with a plasticizer may be additionally performed. The surface area of the lyocell material may be increased by opening the lyocell material. For example, opening of the lyocell material may be performed by applying an external force in a length direction, width direction, and/or thickness direction.
Preferably, the lyocell material used in manufacturing a filter for smoking articles may be a lyocell tow.
Although not particularly limited, the filter for smoking articles may additionally include known cellulose acetate multifilaments at a level that does not hinder the purpose of the present disclosure. Cellulose acetate multifilaments may be blended with lyocell multifilaments. Cellulose acetate multifilaments may be included in a segment distinct from the segment including lyocell multifilaments.

ADVANTAGEOUS EFFECTS OF DISCLOSURE

According to the present application, there are provided a lyocell material for a filter of smoking articles that can replace commercialized cellulose acetate (CA), and a filter for smoking articles including the same. In particular, there is provided a lyocell material that can be used in a filter for a smoking article and can provide a high-quality feeling of use to a user.

MODE OF DISCLOSURE

Hereinafter, the operation and effects of the invention will be described in more detail through specific examples of the disclosure. However, this is presented as an example of the invention and the scope of the invention is not limited thereto in any way.
A lyocell material was prepared through the same process as those described in the following preparation example. Any conditions not specifically mentioned were made within the scope of the above description.

[Preparation Example]

Cellulose pulp having an alpha-cellulose content of 93.9% and a degree of polymerization (DPw) of 820 was mixed with an NMMO/H₂O solvent having a propyl gallate content of 0.01 wt% to prepare a spinning dope for producing a tow with a concentration of 11 wt%. Then, while maintaining a spinning temperature at 110°C in a spinning nozzle, a discharge amount and a spinning rate were appropriately adjusted, and the spinning dope was spun.
The filament-phase spinning dope discharged from the spinning nozzle was supplied through an air gap section to a coagulation liquid (a coagulation liquid having a concentration of 75 wt% water and 25 wt% NMMO based on 100% of the total weight of the coagulation liquid and a temperature of about 25°C) in a coagulation tank. In this case, cooling air in the air gap section first coagulates the spinning dope at a temperature of 8 °C and an air flow rate of 200 N m'/h . Additionally, the concentration of the coagulation liquid was continuously monitored using a sensor and a refractometer.
Then, the coagulated lyocell filaments were washed. In particular, filaments were introduced into a towing roller, and the filaments were sequentially immersed in a first washing tank, a second washing tank, and a third washing tank. The first washing tank, the second washing tank, and the third washing tank included a first washing liquid, a second washing liquid, and a third washing liquid, respectively. A first sprayer and a first dehydrator were placed over the upper end of the first washing tank. The first sprayer sprayed the first washing liquid onto the filaments. The first dehydrator applied air pressure to the filaments to extract the washing liquid from the filaments.
Then, the washed filaments were immersed into a processing bath designed to have a preset oil concentration. The filaments were treated with a pressure of 19.61 N/cm² (2 kgf/cm²) by a nip roll installed in the discharge unit of the processing bath, and were introduced into a crimping machine to provide wrinkles. In particular, the pressure of a press roller was set to 24.52 N/cm² (2.5 kgf/cm²), and the pressure of a doctor blade was set to 4.90 N/cm² (0.5 kgf/cm²) to prepare a lyocell tow.
In order to prevent static electricity and provide flexibility to the prepared tow, a second oil treatment was performed, and immediately after the treatment, the tow passed through a continuous drying device set to 120°C to obtain a dried tow product.
The prepared lyocell tow may have a single fineness of 1.67 to 12 dtex (1.5 to 10.8 denier) and a total fineness of 2,222 to 5,556 tex (20,000 to 50,000 denier), and a yarn fineness of the lyocell multifilament before the application of crimps may be 1,111 to 4,444 tex (10,000 to 40,000 denier), and the number of crimps may be 5.91 to 15.75 ea/cm (15 to 40 ea/inch).

[Examples]

Examples 1 to 11

Lyocell materials were manufactured according to Preparation Example, and single finenesses of lyocell multifilaments, yarn finenesses of lyocell multifilaments, single finenesses of the lyocell materials, and total finenesses of the lyocell materials were as shown in Table 1 below, and specific conditions of the washing process were as shown in Table 2 below.

Comparative Examples 1 to 6

Lyocell materials were manufactured according to Preparation Example, and single finenesses of lyocell multifilaments, yarn finenesses of lyocell multifilaments, single finenesses of the lyocell materials, and total finenesses of the lyocell materials were as shown in Table 1 below, and specific conditions of the washing process were as shown in Table 2 below.
Meanwhile, in the case of Comparative Example 4, when the single fineness of the monofilament forming the lyocell multifilament was less than 1.11 dtex (1.0 denier), a draft ratio, which means a tensile ratio immediately after being discharged from a spinneret, was too high, thus resulting in poor stability of the spinning process, such as yarn breakage, and the production thereof could not be maintained.
Additionally, in the case of Comparative Example 5, the temperature of the first washing liquid was 80°C. As a result, the initial coagulation of the lyocell multifilament was restrictly performed to cause the deterioration of crystallinity, the coagulation of the lyocell multifilament was restricted, and viscosity was maintained, so that continuous production of the lyocell materials was not possible as the filaments were rolled up on the rollers during the transport process of the filaments.

Meanwhile, in the case of Comparative Example 6, a filter for smoking articles burst during the filling process of the filter for smoking articles due to an excessively large yarn fineness. As a result, the manufacturing of a filter for smoking articles was restricted.

[Table 1]

		Single fineness of lyocell multifilament (dtex(d))	Yarn fineness of lyocell multifilament (tex(d))	Single fineness of lyocell material (dtex(d))	Total fineness of lyocell material (tex(d))
	1	1.11 (1.0)	3889 (35000)	1.67 (1.5)	5556 (50000)
	2	2.22 (2.0)	2778 (25000)	3.33 (3.0)	3889 (35000)
	3	2.22 (2.0)	2778 (25000)	3.33 (3.0)	3889 (35000)
	4	2.22 (2.0)	2778 (25000)	3.33 (3.0)	3889 (35000)
	5	2.22 (2.0)	2778 (25000)	3.33 (3.0)	3889 (35000)
Example	6	2.22 (2.0)	2778 (25000)	3.33 (3.0)	3889 (35000)
	7	2.22 (2.0)	3333 (30000)	3.33 (3.0)	4444 (40000)
	8	2.22 (2.0)	3889 (35000)	3.33 (3.0)	5556 (50000)
	9	4.44 (4.0)	2778 (25000)	6.67 (6.0)	4444 (40000)
	10	8.33 (7.5)	2222 (20000)	12.00 (10.8)	3333 (30000)
	11	8.89 (8.0)	2222 (20000)	12.22 (11.0)	3333 (30000)
Comparative Example	1	2.22 (2.0)	3889 (35000)	2.67 (2.4)	5556 (50000)
	2	2.22 (2.0)	2778 (25000)	2.67 (2.4)	3889 (35000)
	3	4.44 (4.0)	4444 (40000)	13.33 (12)	5556 (50000)
	4	0.89 (0.8)	3667 (33000)	1.39 (1.25)	5000 (45000)
	5	8.89 (8.0)	3111 (28000)	12.22 (11.0)	3889 (35000)
	6	4.44 (4.0)	5000 (45000)	6.67 (6.0)	5556 (60000)

[Table 2]

		Temperature of first washing liquid (°C)	Temperature of second washing liquid (°C)	Temperature of third washing liquid (°C)	Air pressure of first dehydrator (N/cm²(kgf/cm²))
	1	25	25	25	9.81 (1)
	2	30	30	30	49.03 (5)
	3	30	30	30	147.10 (15)
	4	30	90	90	147.10 (15)
	5	25	90	90	147.10 (15)
Example	6	60	90	90	147.10 (15)
	7	60	90	90	147.10 (15)
	8	60	90	90	147.10 (15)
	9	60	90	90	147.10 (15)
	10	60	90	90	147.10 (15)
	11	60	90	90	147.10 (15)
Comparative Example	1	25	25	25	9.81 (1)
	2	30	30	30	4.90 (0.5)
	3	60	90	90	147.10 (15)
	4	30	30	30	9.81 (1)
	5	80	90	90	147.10 (15)
	6	60	90	90	147.10 (15)

[Evaluation Example]

<Experiment 1: Evaluation of content of NMMO>

The content of NMMO was evaluated for each of the lyocell materials according to Examples 1 to 11, Comparative Examples 1 to 3, and Comparative Examples 6 to 8. In Comparative Examples 4 and 5, the contents of NMMO could not be evaluated because the materials could not be manufactured.
To evaluate the content of NMMO, 1.0 g of a sample was collected from each of the lyocell materials. The sample was immersed in 40 mL of distilled water, stirred for 10 seconds, and treated with ultrasonic waves for 60 minutes at a temperature of 50 °C. In the process, NMMO was extracted and an NMMO solution was obtained. HPLC analysis was performed using 2 mL of the NMMO solution. Specific HPLC analysis conditions were as follows, and evaluation results thereof were as shown in Table 3 below.

Equipment: WATERS H-Class
Column: CAPCELL PACK C18 (4.6mm * 250mm * 5um)
Injection volume: 10.0 µm
Flow rate: 0.750 mL/min
Oven temperature: 50.0 °C
UV wavelength: 192 nm
Mobile phase: A-Water, B-Acetonitrile (Isocratic)/ 0-10 min: A(95%)+B(5%)

<Experiment 2: Functionality Evaluation of filters for smoking articles>

Functionality of filters for smoking articles, including the lyocell materials according to Examples 1 to 8 and the lyocell materials according to Comparative Examples 1 to 3, respectively, was evaluated. The functionality evaluation was performed on 100 consumers in their 30s and 40s, and was performed using a difference identification evaluation method.
In the case of Comparative Examples 4 and 5, functionality evaluation could not be performed because production of the materials was impossible, and in the case of Comparative Example 6, functionality evaluation could not be performed because production of the filters was impossible.

Evaluation results were analyzed by Analysis of Variance (ANOVA), and sample tests were performed to determine whether a statistically significant difference occurred. Additionally, descriptive responses to unsatisfactory points were collected. A general filter for smoking articles including a cellulose acetate material were used as a control group. Evaluation results are shown in Table 3 below.

[Table 3]

		Manufacturing processability	Content of NMMO (ppm, residual amount)	Functionality evaluation results
Example	1	excellent	451	Same as control group
	2	excellent	2863	Same as control group
	3	excellent	2211	Same as control group
	4	excellent	874	Same as control group
	5	excellent	946	Same as control group
	6	excellent	715	Same as control group
	7	excellent	1655	Same as control group
	8	excellent	2378	Same as control group
	9	excellent	2510	Same as control group
	10	excellent	2659	Same as control group
	11	excellent	2884	Same as control group
Comparative Example	1	excellent	3877	Significant difference from control group
	2	excellent	5641	Significant difference from control group
	3	excellent	4227	Significant difference from control group
	4	Material production impossible	-	-
	5	Material production impossible	-	-
	6	Filter production impossible	4992	-

Referring to Table 3, the lyocell materials of Examples 1 to 11 had excellent manufacturing processability, and the functionality evaluation results showed that they could provide users with a feeling of use substantially the same as that of the control group.
On the other hand, the lyocell materials of Comparative Examples 1 to 3 were found to provide a worse feeling of use than the control group in the functionality evaluation results, and in particular, were reported to exhibit a sweeter taste and sour smell than the control group. Additionally, the lyocell materials of Comparative Examples 4 to 6 could not be used in the manufacturing of filters for smoking articles.

Claims

A lyocell material comprising: a lyocell multifilament to which crimps are applied; and NMMO,
wherein a content of the NMMO is 3000 ppm or less.
The lyocell material of claim 1, wherein the number of the crimps is 10 ea/inch to 60 ea/inch.
The lyocell material of claim 1, wherein the lyocell multifilament to which crimps are applied has a single fineness of 1.5 to 11.0 denier, the lyocell multifilament has a yarn fineness of 10,000 to 40,000 denier, and/or the lyocell material has a total fineness of 15,000 to 55,000 denier.
The lyocell material of claim 1, wherein the content of the NMMO is 100 ppm or more.
The lyocell material of claim 1, wherein the lyocell material satisfies two or more of [condition i] to [condition iii] below:
[condition i] the lyocell multifilament has a single fineness of 1.5 denier or more,

[condition ii] the lyocell multifilament has a yarn fineness of 10,000 denier or more, and

[condition iii] the lyocell material has a total fineness of 20,000 denier or more.
The lyocell material of claim 1, wherein the lyocell multifilament includes one or more monofilaments, and at least one of the monofilaments has a non-circular cross-section.
The lyocell material of claim 1, wherein the lyocell material is a lyocell tow, the lyocell material is used for a filter for smoking articles, and/or the lyocell material is not used for a tire cord.
A filter for smoking articles, the filter comprising the lyocell material of any one of claims 1 to 7.
A smoking article comprising the filter for smoking articles of claim 8.
A method of manufacturing a lyocell material, the method comprising: a
lyocell dope spinning process; a coagulation and lyocell multifilament obtainment process; a washing process; an oil treatment process; and a crimp application process,

wherein the washing process includes use of two or more washing tanks, the washing tanks each independently include a washing liquid, and

temperatures of the washing liquids are each independent and at least two of the temperatures are different from each other.
The method of claim 10, wherein the washing liquid has a temperature of 25°C to 100°C.
The method of claim 10, wherein, when the washing tank in which lyocell multifilaments are washed first is referred to as a first washing tank, the washing liquid included in the first washing tank is referred to as a first washing liquid, the washing tank in which lyocell multifilaments are washed last is referred to as an n-th washing tank, and the washing liquid included in the n-th washing tank is referred to as an n-th washing liquid, the temperature of the first washing liquid is lower than the temperature of the n-th washing liquid.
The method of claim 10, wherein each of the washing tanks is heated.
The method of claim 10, wherein the washing process further includes use of a sprayer, and the sprayer sprays one or more of the washing liquids.
The method of claim 10, wherein the washing process further includes use of a dehydrator, and the dehydrator extracts a washing liquid from a lyocell multifilament, and optionally the dehydrator applies air pressure to the lyocell multifilament to extract the washing liquid from the lyocell multifilament, and the air pressure is 1 kgf/cm² to 15 kgf/cm².