EP4715099A1

EP4715099A1 - Lyocell material, smoking article filter, smoking article, and methods for manufacturing same

Info

Publication number: EP4715099A1
Application number: EP24832448.5A
Authority: EP
Inventors: Sang Jun Yoon; Young Han Jeong; Yeong Nam Hwang; Jong Cheol Jeong; Sang Woo Jin; Jung Hun Lee; Seung Dong SEO; Jin Chul Yang; Sung Hoon Ha; Kyeng Bae Ma; Ki Jin AHN; Min Hee Hwang
Original assignee: Kolon Industries Inc; KT&G Corp
Current assignee: Kolon Industries Inc; KT&G Corp
Priority date: 2023-06-27
Filing date: 2024-06-27
Publication date: 2026-03-25
Also published as: KR20250000907A; CN121399309A; WO2025005670A1

Abstract

The present disclosure relates to a lyocell material, a smoking article filter including the lyocell material, and methods of preparing the same. The lyocell material prepared according to the present disclosure, and a smoking article filter including the same, can replace conventional cellulose acetate materials and filters, while providing not only excellent electrostatic properties but also excellent filter manufacturing processability and superior cigarette properties (e.g., uniform filtration capability).

Description

Technical Field

The present disclosure relates to a lyocell material, a filter including the same, a smoking article, and methods of preparing the same.

Background Art

Until now, cellulose acetate fibers have been mainly used as cigarette filter materials. Although cellulose acetate is known to be a biodegradable substance, smoking article filters made of cellulose acetate maintain their original shape for one to two years after being buried in soil, and require considerable time to fully biodegrade. Considering the volume and toxicity of tobacco products that are discarded into the living environment and left unattended, in addition to tobacco products used for smoking that are recovered as waste and landfilled, it is necessary to further improve the biodegradability of smoking article filters. Accordingly, lyocell, which is more environmentally friendly than cellulose acetate, has recently been selected as a material to replace cellulose acetate.
There is a need for the development of a filter material that can replace conventional cellulose acetate materials while having excellent hardness and quality, providing user satisfaction, and improving productivity.
Meanwhile, the use of lyocell materials has been proposed as an alternative to cellulose acetate materials. However, from the perspective of spreading characteristics, lyocell materials are known to be different from cellulose acetate materials.

Disclosure of Invention

Technical Problem

One objective of the present disclosure is to provide a lyocell material capable of replacing cellulose acetate, which has been commercialized for use in smoking article filters.
Another objective of the present disclosure is to provide a lyocell material for smoking article filters that is environmentally friendly in its manufacturing process and exhibits excellent biodegradability upon disposal.
Another objective of the present disclosure is to provide a lyocell material for smoking article filters with controlled electrostatic properties.
Another objective of the present disclosure is to provide a lyocell filter for smoking articles.
Another objective of the present disclosure is to provide a smoking article (e.g., a cigarette) that includes the lyocell filter.
Another objective of the present disclosure is to improve the processability related to the manufacturing of the lyocell material, the filter, and the smoking article.
The foregoing and other objectives of the present disclosure can all be achieved by the invention of the present disclosure, which is described in detail below.

Solution to Problem

According to embodiments of the present disclosure, a lyocell material, a filter including the lyocell material, a smoking article, and the like may be provided.
The inventors of the present disclosure discovered that by controlling the electrostatic properties of a lyocell material, the spreading characteristics and processability of the lyocell material can be controlled. Furthermore, the present disclosure is based on the realization that, by controlling the spreading characteristics, the process equipment and process conditions used in manufacturing a filter from a cellulose acetate material can be used in substantially the same manner for manufacturing a filter from a lyocell material.
In the present disclosure, the term "spreading characteristics" refers to the characteristic of how a lyocell material spreads. The spread of the lyocell material may occur in one or more steps.
Specifically, the spread of the lyocell material may occur in the longitudinal direction of the lyocell material (i.e., a direction parallel to the stretching direction of the lyocell multifilament), the width direction of the lyocell material (i.e., the direction in which the thickness of the lyocell material is greatest, after the longitudinal direction), and/or the thickness direction of the lyocell material (i.e., a direction perpendicular to both the longitudinal direction and the width direction).
The spread of the lyocell material may be performed by applying an external force to the lyocell material. The external force may be applied in the longitudinal direction, the width direction, and/or the thickness direction of the lyocell material, and the application of the external force may be performed by a mechanical device.
For example, the lyocell material may be spread in the width direction of the lyocell material via one or more air spreaders. Alternatively, the lyocell material may be spread in the longitudinal direction of the lyocell material via one or more air spreaders.
Alternatively, the lyocell material may be sequentially spread in the width direction of the lyocell material and the longitudinal direction of the lyocell material via two or more air spreaders. Alternatively, the lyocell material may be sequentially spread in the longitudinal direction of the lyocell material and the width direction of the lyocell material via two or more air spreaders. Alternatively, the lyocell material may be simultaneously spread in the width direction of the lyocell material and the longitudinal direction of the lyocell material via a single air spreader.
Through spreading, the lyocell material can be uniformly unfolded, sufficient bulking can be generated from the uniformly unfolded lyocell material, and by means of the bulking, the entanglement between monofilaments and/or between lyocell multifilaments can be increased. A sufficiently spread lyocell material can be included in a smoking article filter and function as a filter.
For example, a lyocell material can be gathered via one or more Tow Transfer Jets (TTJs) so that the lyocell material, which has been spread in the longitudinal and width directions, is filled into a filter wrapper. Specifically, a TTJ can draw in the spread lyocell material to converge the spread lyocell material, and the lyocell material can then be spread into the interior of a filter wrapper via one or more TTJs.
Meanwhile, if the spread of the lyocell material occurs non-uniformly, the spreading characteristics of the lyocell material can be evaluated as being poor. Specifically, the spreading characteristics of the lyocell material can be evaluated as being poor if the spread of the lyocell material is non-uniform in the width direction, the spread of the lyocell material is non-uniform in the thickness direction, or the spread of the lyocell material is non-uniform in both the width and thickness directions.
For example, if, due to insufficient spreading of the lyocell material, clumping of the emulsion contained in the lyocell material is visually observed, or clumping of the multifilaments in the lyocell material is visually observed, the spreading characteristics of the lyocell material can be evaluated as being poor.
More specifically, if the change in the width direction of the lyocell material is a factor of 3 or more during the spreading process by an air spreader, and the change in the width of lyocell material remains consistent while a subsequent process is performed, the spreading characteristics of the lyocell material can be evaluated as being good.
Conversely, the spreading characteristics of the lyocell material can be evaluated as being poor if the change in the width direction of the lyocell material is less than a factor of 3 during the spreading process by an air spreader; if the cumulative width of gaps across the lyocell material is 20 % or more relative to the total widthwise length of the lyocell material; or if the change in the width of the lyocell material is 50 % or more while a subsequent process is performed.
For example, the visual observation of the lyocell material for the evaluation of spreading characteristics may be performed during the spreading process and/or the conveying process.
For example, if bulking fails to occur on the portion of the lyocell material subjected to an external force, the spreading characteristics of the lyocell material can be evaluated as being poor.
Additionally, if breakage of the lyocell material and/or breakage of the lyocell multifilaments occurs during the spreading process of the lyocell material, the spreading characteristics can be evaluated as being poor. Due to the breakage of the lyocell multifilaments, ply can be formed on the surface of the lyocell material. The breakage of the lyocell material and/or the breakage of the lyocell multifilaments can be confirmed by visual inspection.
During the additional processing of a lyocell material for its use in a smoking article filter, breakage and/or ply can occur in a lyocell material that has poor spreading characteristics. For example, to cause bulking in a lyocell material, an external force can be applied to the lyocell material by a spreading device in the longitudinal, width, and thickness directions, and breakage and/or ply can occur in the lyocell material due to the external force.
More specifically, while a lyocell material is being conveyed in the longitudinal direction, an external force can be simultaneously applied in its width and thickness directions; due to the external force, breakage of the lyocell multifilaments can occur during the process in which some of the lyocell multifilaments included in the lyocell material are spread; and furthermore, the breakage of the lyocell multifilaments can lead to the breakage of the lyocell material. As a result, the conveying of the lyocell material may be stopped, the production of the smoking article filter may be limited, or the performance of the smoking article filter may be degraded.
Specifically, according to an example of the present disclosure, a lyocell material may be provided, the material including a crimped lyocell multifilament and an emulsion coated on the lyocell multifilament, wherein the emulsion includes (a) an ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol, and (b) an ester of sorbitan and a fatty acid having 16 or more carbons.
According to another embodiment of the present disclosure, a lyocell smoking article filter may be provided, including a lyocell material, wherein the lyocell material includes a crimped lyocell multifilament and an emulsion coated on the lyocell multifilament, the emulsion including (a) an ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol, and (b) an ester of sorbitan and a fatty acid having 16 or more carbons.
According to another embodiment of the present disclosure, a smoking article including the lyocell material or the filter may be provided.
According to another embodiment of the present disclosure, methods of preparing the lyocell material, the filter including the lyocell material, and the smoking article may be provided.
In the present specification, the term "smoking article" may refer to an article, such as a cigarette or a cigar, capable of generating an aerosol. In this regard, the smoking article may include an aerosol-generating material or an aerosol-forming substrate. In addition, the smoking article may include a solid material based on a tobacco raw material, such as cast-leaf tobacco, cut tobacco, or reconstituted tobacco. In addition, the smoking material may include a volatile compound.
Unless otherwise defined herein, in a case where the characteristics of the lyocell material, the smoking article filter, or relevant components or configurations are affected by temperature, the temperature at which such characteristics are identified or measured may be room temperature. Room temperature, in the absence of intentional cooling or heating, may be, for example, a temperature in the range from 10 to 35 °C, specifically, from 15 to 35 °C, from 20 to 30 °C, or about 25 °C.
Hereinbelow, the present disclosure will be described in further detail.
An embodiment of the present disclosure relates to a lyocell material. Although not particularly limited, the lyocell material may be used for a smoking article filter.
According to an exemplary embodiment, a lyocell material for a smoking article filter includes a crimped lyocell multifilament and an emulsion coated on at least a portion of the lyocell multifilament, wherein an electrostatic value measured from the lyocell material is about 0.01 kV to about 1.4 kV.
In an exemplary lyocell material for a smoking article filter, the electrostatic value may be about 0.05 kV to about 1.2 kV.
In an exemplary lyocell material for a smoking article filter, the electrostatic value may be about 0.05 kV to about 1.0 kV.
In an exemplary lyocell material for a smoking article filter, the electrostatic value may be about 0.08 kV to about 1.05 kV.
In an exemplary lyocell material for a smoking article filter, the electrostatic value may be about 0.10 kV to about 1.05 kV.
In an exemplary lyocell material for a smoking article filter, the electrostatic value may be measured by a friction method.
In an exemplary lyocell material for a smoking article filter, the friction method may be a method of measuring the static electricity generated from the lyocell material by means of friction.
In an exemplary lyocell material for a smoking article filter, the friction method may be a method of measuring the static electricity generated from a dried lyocell material.
In an exemplary lyocell material for a smoking article filter, the friction method may be a method of measuring the static electricity generated at room temperature.
Additionally, room temperature may be a temperature condition of about 20 °C to about 25 °C. For example, the friction method may be a method of measuring the static electricity generated under a temperature condition of about 21 °C.
In an exemplary lyocell material for a smoking article filter, the friction method may be a method of measuring the static electricity generated under a humidity condition of about 35 % RH.
In an exemplary lyocell material for a smoking article filter, the friction may occur under a condition in which at least a portion of the lyocell material is pressed.
In an exemplary lyocell material for a smoking article filter, the pressing may be performed by the load of an abrasion wheel.
In an exemplary lyocell material for a smoking article filter, the load applied by the abrasion wheel may be about 200 g to about 300 g. Additionally, the load may be about 250 g.
In an exemplary lyocell material for a smoking article filter, the friction between the lyocell material and the abrasion wheel may be generated by the rotation of the lyocell material.
In an exemplary lyocell material for a smoking article filter, the friction between the lyocell material and the abrasion wheel may be generated by the rotation of the abrasion wheel.
In an exemplary lyocell material for a smoking article filter, the lyocell material or the abrasion wheel may be rotated at about 40 cycle/min to about 80 cycle/min. Additionally, the lyocell material or the abrasion wheel may be rotated at about 60 cycle/min. By means of the rotation of the lyocell material and/or the rotation of the abrasion wheel, friction may be generated between the lyocell material and the abrasion wheel. Additionally, by means of the friction, static electricity may be induced on and measured from the surface of the lyocell material.
In an exemplary lyocell material for a smoking article filter, the number of rotations of the lyocell material or the abrasion wheel may be about 5 to about 50. The number of rotations of the lyocell material or the abrasion wheel may be about 10 to about 30.
In an exemplary lyocell material for a smoking article filter, the static electricity may be measured by an electrostatic field meter, and the electrostatic field meter may be spaced apart from the lyocell material.
In an exemplary lyocell material for a smoking article filter, the electrostatic field meter may be disposed on one surface of the lyocell material.
In an exemplary lyocell material for a smoking article filter, the electrostatic field meter may be spaced apart from the lyocell material by about 0.1 cm to about 10 cm. Additionally, the electrostatic field meter may be spaced apart from the lyocell material by about 5 cm. Furthermore, the long axis of the electrostatic field meter and a virtual plane parallel to the direction of rotation of the lyocell material may intersect each other or be perpendicular to each other.
In an exemplary lyocell material for a smoking article filter, the emulsion may include: (a) an ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol; and (b) an ester of sorbitan and a fatty acid having 16 or more carbons.
In an exemplary lyocell material for a smoking article filter, the emulsion may include, per 100 parts by weight of (a) the ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol, from 20 to 60 parts by weight of (b) the ester of sorbitan and a fatty acid having 16 or more carbons.
In an exemplary lyocell material for a smoking article filter, the emulsion may further include (c) an alkylene oxide adduct of the aforementioned ester (b).
In an exemplary lyocell material for a smoking article filter, the emulsion may include, per 100 parts by weight of the aforementioned (a) ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol, from 10 to 50 parts by weight of the aforementioned (c) alkylene oxide adduct of the ester (b).
In an exemplary lyocell material for a smoking article filter, the crimped lyocell multifilament may have a total fineness of 15,000 to 45,000 denier and from 20 to 50 crimps per inch.
In an exemplary lyocell material for a smoking article filter, the emulsion may be included in a content of about 0.1 wt% or more, based on 100 wt% of the total lyocell material for a smoking article filter. Additionally, the emulsion may be included in a content of about 0.5 wt% or more.
In an exemplary lyocell material for a smoking article filter, the emulsion may be included in a content of about 20 wt% or less, based on 100 wt% of the total lyocell material for a smoking article filter.
In an exemplary lyocell material for a smoking article filter, the emulsion may be included in a content of about 9 wt% or less, based on 100 wt% of the total lyocell material for a smoking article filter.
In an exemplary lyocell material for a smoking article filter, the emulsion may be included in a content of about 0.5 wt% to 9 wt% or less, based on 100 wt% of the total lyocell material for a smoking article filter.
Additionally, a smoking article including any one of the exemplary lyocell materials for a smoking article filter is provided.
Additionally, an exemplary method of preparing a lyocell material for a smoking article filter includes the steps of: treating a lyocell multifilament with an emulsion; and imparting crimps to the lyocell multifilament, wherein the step of treating with an emulsion is performed such that the electrostatic value measured from the lyocell material for a smoking article filter is about 0.01 kV to 1.4 kV.

Method of Preparing Lyocell Material For Smoking Article Filter

In an exemplary method of preparing a lyocell material for a smoking article filter, the emulsion may include (a) an ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol, and (b) an ester of sorbitan and a fatty acid having 16 or more carbons.
In an exemplary method of preparing a lyocell material for a smoking article filter, the emulsion may be included in a content of about 0.1 wt% or more, based on 100 wt% of the total lyocell material for a smoking article filter.
In an exemplary method of preparing a lyocell material for a smoking article filter, the emulsion may be included in a content of about 20 wt% or less, based on 100 wt% of the total lyocell material for a smoking article filter.
In an exemplary method of preparing a lyocell material for a smoking article filter, a lyocell multifilament having a total fineness of 15,000 to 45,000 denier and having 20 to 50 crimps formed per inch may be provided.
Additionally, a smoking article filter according to an exemplary embodiment includes a lyocell material, wherein the lyocell material includes: a crimped lyocell multifilament; and an emulsion coated on the lyocell multifilament, and wherein an electrostatic value measured from the lyocell material is about 0.01 kV to about 1.4 kV.
Additionally, an exemplary smoking article includes a smoking article filter according to any one of the exemplary embodiments.
Additionally, an exemplary method of preparing a smoking article filter includes: treating a lyocell multifilament with an emulsion; imparting crimps to the lyocell multifilament; and manufacturing a filter using the crimped lyocell multifilament, wherein the treatment with the emulsion is performed such that the electrostatic value measured from the lyocell material for a smoking article filter is about 0.01 kV to 1.4 kV.
The electrostatic value measured from a lyocell material according to an exemplary embodiment may be about 0.01 kV to about 1.4 kV, and may be 0.05 kV to 1.2 kV. Specifically, the electrostatic value measured from the lyocell material may be from 0.08 kV to 1.05 kV, 0.10 kV to 1.05 kV, 0.12 kV to 1.05 kV, 0.13 kV to 1.05 kV, 0.14 kV to 1.05 kV, 0.15 kV to 1.05 kV, 0.16 kV to 1.05 kV, 0.17 kV to 1.05 kV, 0.18 kV to 1.05 kV, 0.19 kV to 1.05 kV, 0.20 kV to 1.05 kV, 0.21 kV to 1.05 kV, 0.22 kV to 1.05 kV, 0.23 kV to 1.05 kV, 0.24 kV to 1.05 kV, 0.25 kV to 1.05 kV, 0.26 kV to 1.05 kV, 0.27 kV to 1.05 kV, 0.28 kV to 1.05 kV, 0.29 kV to 1.05 kV, 0.30 kV to 1.05 kV, 0.31 kV to 1.05 kV, 0.32 kV to 1.05 kV, 0.33 kV to 1.05 kV, 0.34 kV to 1.05 kV, 0.35 kV to 1.05 kV, 0.36 kV to 1.05 kV, 0.37 kV to 1.05 kV, 0.38 kV to 1.05 kV, 0.39 kV to 1.05 kV, 0.40 kV to 1.05 kV, 0.41 kV to 1.05 kV, 0.42 kV to 1.05 kV, 0.43 kV to 1.05 kV, 0.44 kV to 1.05 kV, 0.45 kV to 1.05 kV, 0.46 kV to 1.05 kV, 0.47 kV to 1.05 kV, 0.48 kV to 1.05 kV, 0.49 kV to 1.05 kV, 0.50 kV to 1.05 kV, 0.61 kV to 1.05 kV, 0.62 kV to 1.05 kV, 0.63 kV to 1.05 kV, 0.64 kV to 1.05 kV, 0.65 kV to 1.05 kV, 0.66 kV to 1.05 kV, 0.67 kV to 1.05 kV, 0.68 kV to 1.05 kV, 0.69 kV to 1.05 kV, or 0.70 kV to 1.05 kV.
For example, the lower limit of the electrostatic value may be 0.05 kV or more, 0.06 kV or more, 0.07 kV or more, 0.08 kV or more, 0.09 kV or more, 0.10 kV or more, 0.11 kV or more, 0.12 kV or more, 0.13 kV or more, 0.14 kV or more, 0.15 kV or more, 0.16 kV or more, 0.17 kV or more, 0.18 kV or more, 0.19 kV or more, 0.20 kV or more, 0.21 kV or more, 0.22 kV or more, 0.23 kV or more, 0.24 kV or more, 0.25 kV or more, 0.26 kV or more, 0.27 kV or more, 0.28 kV or more, 0.29 kV or more, 0.30 kV or more, 0.31 kV or more, 0.32 kV or more, 0.33 kV or more, 0.34 kV or more, 0.35 kV or more, 0.36 kV or more, 0.37 kV or more, 0.38 kV or more, 0.39 kV or more, 0.40 kV or more, 0.41 kV or more, 0.42 kV or more, 0.43 kV or more, 0.44 kV or more, 0.45 kV or more, 0.46 kV or more, 0.47 kV or more, 0.48 kV or more, 0.49 kV or more, 0.50 kV or more, 0.51 kV or more, 0.52 kV or more, 0.53 kV or more, 0.54 kV or more, 0.55 kV or more, 0.56 kV or more, 0.57 kV or more, 0.58 kV or more, 0.59 kV or more, 0.60 kV or more, 0.61 kV or more, 0.62 kV or more, 0.63 kV or more, 0.64 kV or more, 0.65 kV or more, 0.66 kV or more, 0.67 kV or more, 0.68 kV or more, 0.69 kV or more, 0.70 kV or more, 0.71 kV or more, 0.72 kV or more, 0.73 kV or more, 0.74 kV or more, 0.75 kV or more, 0.76 kV or more, 0.77 kV or more, 0.78 kV or more, 0.79 kV or more, 0.80 kV or more, 0.81 kV or more, 0.82 kV or more, 0.83 kV or more, 0.84 kV or more, 0.85 kV or more, 0.86 kV or more, 0.87 kV or more, 0.88 kV or more, 0.89 kV or more, 0.90 kV or more, 0.91 kV or more, 0.92 kV or more, 0.93 kV or more, 0.94 kV or more, 0.95 kV or more, 0.96 kV or more, 0.97 kV or more, 0.98 kV or more, or 0.99 kV or more. Further, the upper limit of the electrostatic value may be 1.35 kV or less, 1.30 kV or less, 1.25 kV or less, 1.20 kV or less, 1.15 kV or less, 1.14 kV or less, 1.13 kV or less, 1.12 kV or less, 1.11 kV or less, 1.10 kV or less, 1.09 kV or less, 1.08 kV or less, 1.07 kV or less, 1.06 kV or less, 1.05 kV or less, 1.04 kV or less, 1.03 kV or less, 1.02 kV or less, 1.01 kV or less, 1.00 kV or less, 0.95 kV or less, 0.90 kV or less, 0.85 kV or less, 0.80 kV or less, 0.75 kV or less, 0.70 kV or less, 0.65 kV or less, 0.60 kV or less, 0.55 kV or less, or 0.50 kV or less.
If the electrostatic value does not satisfy the aforementioned numerical range, the spreading characteristics of the lyocell material are degraded. Specifically, when an external force (for instance, a tensile force) is applied to a lyocell material to spread the lyocell material, the lyocell material may fail to spread to a uniform thickness and/or a uniform width. This poor spreading may, in turn, cause the lyocell material to scatter or form ply during the manufacturing process of the filter including the lyocell material.
Additionally, if the electrostatic value does not satisfy the aforementioned numerical range, a stronger external force may be required to achieve a uniform spread of the lyocell material, which can cause the lyocell material itself to break during the spreading process of the lyocell material. As a result, these process failures may lead to a halt in the manufacturing process of the filter including the lyocell material and an increase in manufacturing costs.
Meanwhile, if the electrostatic value fails to satisfy the aforementioned numerical range, the lyocell material may fail to unfold uniformly in the width direction. In this case, the uniformity of the filter including the lyocell material may be degraded, and the filtration capability of the filter including the lyocell material may be degraded due to the non-uniform arrangement of the lyocell material. Meanwhile, a lyocell material according to an exemplary embodiment includes an emulsion, and the emulsion may have hydrophobicity. Further details of the emulsion are as described in the present specification. Typically, using a hydrophobic emulsion increases the generation of static electricity in the lyocell material compared to using a hydrophilic emulsion.
Meanwhile, if the electrostatic value is less than a lower limit, more preferably below 0.08 kV, the lyocell multifilament may have insufficient frictional properties. This may cause the emulsion to fail to be sufficiently dispersed on the lyocell multifilaments, resulting in observable clumping of the emulsion. Further, it may lead to insufficient friction being generated between the crimp machine and the lyocell multifilament during the process in which crimps are imparted to the lyocell multifilaments. Furthermore, it may lead to an inadequate number of crimps being imparted to the lyocell multifilaments, and the uniformity of the imparted crimps may be significantly poor.
However, as is demonstrated by the exemplary embodiments, including the emulsion in the lyocell material such that predetermined conditions are satisfied, can instead suppress the generation of static electricity from the external environment or an external force. For example, by ensuring the total emulsion content (OPU) is within a predetermined range, the generation of static electricity from the lyocell material can be suppressed even under high-temperature conditions.
As a result, the manufacturing process of a filter using the lyocell material according to an exemplary embodiment is less subject to environmental constraints related to the generation of static electricity, and the reproducibility of the filter manufacturing process can be improved.
More specifically, the lyocell material includes a crimped lyocell multifilament, and an emulsion coated on the lyocell multifilament. The emulsion includes (a) an ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol, and (b) an ester of sorbitan and a fatty acid having 16 or more carbons. This emulsion may be applied to coat a part or all of the mono- or multifilaments constituting the lyocell material. Furthermore, the emulsion may penetrate between the filaments.
An emulsion containing at least the components (a) and (b) may have hydrophobic properties. Accordingly, the electrostatic properties of the lyocell surface may be controlled through the use of such an emulsion. As a result, the lyocell material treated with the emulsion has excellent spreading properties.
In an embodiment of the present disclosure, the lyocell material may contain the emulsion in a predetermined amount. Here, the content of the emulsion may refer to OPU (wt%), which is described below. For example, the lyocell material may include the emulsion in a content of 0.1 wt% or more based on 100 wt% of the total lyocell material. Specifically, the lower limit of the content of the emulsion may be 0.5 wt% or more, 0.6 wt% or more, 0.7 wt% or more, 0.8 wt% or more, 0.9 wt% or more, 1.0 wt% or more, 1.1 wt% or more, 1.2 wt% or more, 1.3 wt% or more, 1.4 wt% or more, 1.5 wt% or more, 1.6 wt% or more, 1.7 wt% or more, 1.8 wt% or more, 1.9 wt% or more, 2.0 wt% or more, 2.1 wt% or more, 2.2 wt% or more, 2.3 wt% or more, 2.4 wt% or more, 2.5 wt% or more, 2.6 wt% or more, 2.7 wt% or more, 2.8 wt% or more, 2.9 wt% or more, 3.0 wt% or more, 3.1 wt% or more, 3.2 wt% or more, 3.3 wt% or more, 3.4 wt% or more, 3.5 wt% or more, 3.6 wt% or more, 3.7 wt% or more, 3.8 wt% or more, 3.9 wt% or more, 4.0 wt% or more, 4.1 wt% or more, 4.2 wt% or more, 4.3 wt% or more, 4.4 wt% or more, 4.5 wt% or more, 4.6 wt% or more, 4.7 wt% or more, 4.8 wt% or more, 4.9 wt% or more, 5.0 wt% or more, 5.1 wt% or more, 5.2 wt% or more, 5.3 wt% or more, 5.4 wt% or more, 5.5 wt% or more, 5.6 wt% or more, 5.7 wt% or more, 5.8 wt% or more, 5.9 wt% or more, 6.0 wt% or more, 6.1 wt% or more, 6.2 wt% or more, 6.3 wt% or more, 6.4 wt% or more, 6.5 wt% or more, 6.6 wt% or more, 6.7 wt% or more, 6.8 wt% or more, 6.9 wt% or more, 7.0 wt% or more, 7.1 wt% or more, 7.2 wt% or more, 7.3 wt% or more, 7.4 wt% or more, or 7.5 wt% or more. Furthermore, the upper limit of the content of the emulsion 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, 7.6 wt%, 7.5 wt% or less, 7.4 wt% or less, 7.3 wt% or less, 7.2 wt% or less, 7.1 wt% or less, 7.0 wt% or less, 6.9 wt% or less, 6.8 wt% or less, 6.7 wt% or less, 6.6 wt% or less, 6.5 wt% or less, 6.4 wt% or less, 6.3 wt% or less, 6.2 wt% or less, 6.1 wt% or less, 6.0 wt% or less, 5.9 wt% or less, 5.8 wt% or less, 5.7 wt% or less, 5.6 wt% or less, 5.5 wt% or less, 5.4 wt% or less, 5.3 wt% or less, 5.2 wt% or less, 5.1 wt% or less, 5.0 wt% or less, 4.9 wt% or less, 4.8 wt% or less, 4.7 wt% or less, 4.6 wt% or less, 4.5 wt% or less, 4.4 wt% or less, 4.3 wt% or less, 4.2 wt% or less, 4.1 wt% or less, 4.0 wt% or less, 3.9 wt% or less, 3.8 wt% or less, 3.7 wt% or less, 3.6 wt% or less, 3.5 wt% or less, 3.4 wt% or less, 3.3 wt% or less, 3.2 wt% or less, 3.1 wt% or less, 3.0 wt% or less, 2.9 wt% or less, 2.8 wt% or less, 2.7 wt% or less, 2.6 wt% or less, 2.5 wt% or less, 2.4 wt% or less, 2.3 wt% or less, 2.2 wt% or less, 2.1 wt% or less, 2.0 wt% or less, 1.9 wt% or less, 1.8 wt% or less, 1.7 wt% or less, 1.6 wt% or less, 1.5 wt% or less, 1.4 wt% or less, 1.3 wt% or less, 1.2 wt% or less, 1.1 wt% or less, 1.0 wt% or less, 0.9 wt% or less, 0.8 wt% or less, or 0.7 wt% or less.
A method for measuring the emulsion content (OPU) may, for example, employ an extrusion technique. For example, a sample (e.g., 2 to 5 g, specifically about 2.5 g) is taken (the weight of this sample is referred to as the "sample weight") and placed into a syringe-shaped container. Although not particularly limited, the material of the container may be stainless steel (SUS). Next, a solvent (e.g., methanol) is added to the container containing the sample (the amount of the solvent added may be 10 ml or less (e.g., about 8 ml)). The solvent is added dropwise to the sample, and the drop rate is controlled to be uniform. The solvent thus introduced into the container is then allowed to drop from one end of the syringe-shaped container onto a plate. The plate is pre-weighed (this weight is referred to as "plate weight A"), and the plate is installed such that the solvent dropped thereon can be driven off (i.e., evaporated) at a temperature of 120 to 130 °C (e.g., 125 °C). The aforementioned solvent addition and dropping is performed three times, and then, using the syringe-shaped container, the sample is pressed once by applying pressure (e.g., 10 kgf/cm² or less, 5 kgf/cm² or less, or 2-4 kgf/cm²) thereto. This sufficiently extrudes the solvent and emulsion present in the sample. Pressure is applied to squeeze the sample until no more solvent is expressed. Thereafter, the plate is stored in a desiccator for 5 minutes to 10 minutes, and the weight of the plate containing the sample is measured (plate weight B). The emulsion content is calculated according to the following Equation: $\begin{array}{l} Emulsion content by extrusion (OPU, % or wt %) \\ = \{(Plate weight B - Plate weight A) / (Sample weight)\} \times 100 \end{array}$
In addition, the lyocell material used as a basis for emulsion content may be a lyocell multifilament that has undergone at least one emulsion treatment. For example, the lyocell material may be a lyocell multifilament to which a first emulsion treatment (described below) has been applied, a lyocell multifilament to which both first emulsion treatment and second emulsion treatment (described below) have been applied, or a lyocell multifilament to which a binder (described below) has been applied in addition to the aforementioned emulsion treatment(s). Furthermore, the lyocell multifilament, having undergone the emulsion and/or binder treatment as described above, may also be crimped.
With respect to the emulsion of the present disclosure, component (a) is a compound that can function as a lubricant or oil, and is a component harmless enough for use in food products for human consumption. Component (a) imparts lubricity to the fibers fed into a crimper. Insufficient lubricity may cause the lyocell to clump and fail to exit the crimper, whereas excessively high lubricity may lead to poor crimp formation. Taking these functions into consideration, the content of component (a) may be controlled as described below.
Regarding component (a), the type of fatty acid having 16 or more carbons that forms component (a) is not particularly limited. A fatty acid having 16 or more carbons that can provide an ester harmless enough for use in food products for human consumption may be used.
For example, as the fatty acid having 16 or more carbons, a saturated fatty acid and/or an unsaturated fatty acid may be used.
Examples of the saturated fatty acid 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), or arachidic acid (eicosanoic acid, CH₃(CH₂)₁₈COOH). However, the types of saturated fatty acids that can be used are not limited to these examples.
Examples of the unsaturated fatty acid include palmitoleic acid (CH₃(CH₂)₅CH=CH(CH₂)₇COOH), oleic acid (CH₃(CH₂)₇CH=CH(CH₂)₇COOH), linoleic acid (C₁₈H₃₂O₂), or arachidonic acid (C₂₀H₃₂O₂). However, the types of saturated fatty acids that can be used are not limited to these examples.
Although the upper limit for the number of carbons in the fatty acid having 16 or more carbons is not particularly limited, the fatty acid may, for example, have 40 or fewer carbons, 36 or fewer carbons, 32 or fewer carbons, 28 or fewer carbons, 24 or fewer carbons, or 20 or fewer carbons.
Regarding component (a), the type of aliphatic monohydric alcohol that forms component (a) is not particularly limited. An aliphatic monohydric alcohol capable of forming an ester harmless enough for use in food products for human consumption may be used.
For example, the aliphatic monohydric alcohol may be either a saturated or unsaturated aliphatic alcohol, which may take a linear or branched form.
In an embodiment, the aliphatic monohydric alcohol may have from 1 to 40 carbons. Specifically, the aliphatic monohydric alcohol may, for example, have 4 or more carbons, 8 or more carbons, 12 or more carbons, 16 or more carbons, or 20 or more carbons.
Examples of such aliphatic monohydric alcohols may include methanol, ethanol, butanol, lauryl alcohol, isotridecanol, and stearyl alcohol, without being limited thereto.
In an embodiment of the present disclosure, an ester of isotridecanol and stearic acid (e.g., isotridecyl stearate) may be used as component (a). However, the type of component (a) that can be used is not limited thereto.
As will be described below, the content of component (a) in the emulsion may be controlled in consideration of the intended function of component (a) or that of the emulsion.
Component (b), which is an ester of sorbitan and a fatty acid having 16 or more carbons, is a compound that can function as an emulsifier and is a component harmless enough for use in food products for human consumption.
Because component (b) has both hydrophilic and hydrophobic properties due to the polyhydric alcohol (i.e., sorbitan), it allows component (a), which imparts lubricity to the fibers, to be well dispersed in water, as described below. Moreover, when used together, components (a) and (b) not only enhance the dispersibility of the emulsion as mentioned above but also lower the melting point, thereby ensuring the ease of handling and stability of the emulsion. The content of component (b) may be controlled in consideration of these functions, as described below.
Regarding component (b), the type of fatty acid having 16 or more carbons that forms component (b) is not particularly limited. A fatty acid having 16 or more carbons that can yield an ester harmless enough for use in food products for human consumption, may be used.
For example, the fatty acid having 16 or more carbons may be a saturated and/or unsaturated fatty acid.
Examples of the saturated fatty acid 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), arachidic acid (eicosanoic acid, CH₃(CH₂)₁₈COOH), and the like. However, the types of saturated fatty acids that can be used are not limited to these examples.
Examples of the unsaturated fatty acid include palmitoleic acid (CH₃(CH₂)₅CH=CH(CH₂)₇COOH), oleic acid (CH₃(CH₂)₇CH=CH(CH₂)₇COOH), linoleic acid (C₁₈H₃₂O₂), arachidonic acid (C₂₀H₃₂O₂), and the like. However, the types of saturated fatty acids that can be used are not limited to these examples.
Although the upper limit for the number of carbons in the fatty acid having 16 or more carbons is not particularly limited, the fatty acid may, for example, have 40 or fewer carbons, 36 or fewer carbons, 32 or fewer carbons, 28 or fewer carbons, 24 or fewer carbons, or 20 or fewer carbons.
In an embodiment of the present disclosure, an ester of sorbitan and oleic acid (e.g., sorbitan monooleate) may be used as component (b). However, the type of component (b) that can be used is not limited thereto.
The content of component (b) may be controlled in consideration of the intended function of component (b) and that of the emulsion.
In an embodiment, the emulsion may include, per 100 parts by weight of component (a), which is an ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol, 20 to 60 parts by weight of component (b), which is an ester of sorbitan and a fatty acid having 16 or more carbons.
Specifically, the emulsion of the present disclosure may contain 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, per 100 parts by weight of component (a). The upper limit of the content of component (b), per 100 parts by weight of 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 aforementioned content range is satisfied, the surface of the emulsion-treated lyocell multifilament or lyocell tow may acquire hydrophobicity, which in turn allows the electrostatic properties measured from the surface of the lyocell tow to be controlled.
In an embodiment, the emulsion may further include, as component (c), an alkylene oxide adduct of component (b). This component (c) can function as a type of emulsifier. This compound may also be selected from those that are harmless enough for use in food products for human consumption.
With respect to component (c), although the type of alkylene oxide is not particularly limited, the alkylene oxide may, for example, have from 2 to 4 carbons. Specifically, with respect to component (c), ethylene oxide, propylene oxide, and/or butylene oxide may be used, but the disclosure is not limited thereto.
The number of added moles of the alkylene oxide is not particularly limited. For example, the number of added moles of the alkylene oxide may be 1 to 100, 5 to 80, 10 to 60, or 15 to 40.
In an embodiment of the present disclosure, an ester of a PEO adduct of sorbitan and oleic acid (e.g., polyoxyethylene sorbitan monooleate) may be used as component (c). However, the type of component (c) that can be used is not limited thereto.
For example, component (c) may be used to further lower the level of static electricity of the lyocell fibers (lyocell staple) during the manufacturing process of the smoking article filter. Specifically, units derived from the alkylene oxide cause moisture to be adsorbed onto the fiber surface, which can suppress the generation of static electricity. Furthermore, component (c) may also serve to facilitate the emulsion to be effectively dispersed in water.
The content of component (c) may be controlled in consideration of the intended function of component (c) and that of the emulsion.
In an embodiment, the emulsion may include 10 to 50 parts by weight of component (c), which is the alkylene oxide adduct of the ester of component (b), per 100 parts by weight of component (a), which is the ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol.
Specifically, the emulsion of the present disclosure may include component (c) in a content of 15 parts by weight or more, 20 parts by weight or more, 25 parts by weight or more, 30 parts by weight or more, 35 parts by weight or more, 40 parts by weight or more, or 45 parts by weight or more, per 100 parts by weight of component (a). Further, the upper limit of the content of component (c), per 100 parts by weight of component (a), may be, for example, 45 parts by weight or less, 40 parts by weight or less, 35 parts by weight or less, 30 parts by weight or less, 25 parts by weight or less, 20 parts by weight or less, or 15 parts by weight or less.
In an embodiment, the emulsion may include component (b), an ester of sorbitan and a fatty acid having 16 or more carbons, in excess relative to component (c), the alkylene oxide adduct of the component (b).
In an embodiment, the emulsion may include 40 to 80 wt% of component (a), which is an ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol, based on 100 wt% of the total weight of the emulsion. Specifically, based on 100 wt% of the total weight of the emulsion, the content of component (a) may be 45 wt% or more, 50 wt% or more, 55 wt% or more, 60 wt% or more, 65 wt% or more, 70 wt% or more, or 75 wt% or more. Further, the upper limit of the content of component (a) 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.
In an embodiment, the emulsion may include component (a) in the largest amount among components (a) to (c).
In an embodiment, the emulsion may include 15 to 55 wt% of component (b), which is an ester of sorbitan and a fatty acid having 16 or more carbons, based on 100 wt% of the total weight of the emulsion. Specifically, based on 100 wt% of the total weight of the emulsion, the content of 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. And, the upper limit of the content of component (b) 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.
In an embodiment, the emulsion may include from 10 to 30 wt% of component (c), i.e., the alkylene oxide adduct of the component (b), based on 100 wt% of the total weight of the emulsion. Specifically, based on 100 wt% of the total weight of the emulsion, the content of component (c) may be 15 wt% or more, 20 wt% or more, or 25 wt% or more. And, the upper limit of the content of component (c) may be, for example, 25 wt% or less, 20 wt% or less, or 15 wt% or less.
In an embodiment, based on 100 wt% of the total weight of the emulsion, the emulsion may include at least 15 wt% of the sum of component (b), an ester of sorbitan and a fatty acid having 16 or more carbons; and component (c), the alkylene oxide adduct of said component (b). Specifically, based on 100 wt% of the total weight of the emulsion, the sum of contents of component (b) and component (c) 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. Further, the upper limit of the sum of contents of component (b) and component (c) may be, for example, 55 wt% or less, 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.
In an embodiment, the emulsion may further include (d) water. As described below, water used in a small amount aids in emulsification.
The water content may not be particularly limited and may correspond to a residual amount obtained by subtracting the total contents of components (a) to (c) from 100 wt% of the total emulsion. The water content included in the emulsion (i.e., a residual amount obtained by subtracting the total content of the other 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 of the water content may be, for example, 0 wt% or more, 0.1 wt% or more, 0.5 wt% or more, or 1 wt% or more.
The lyocell material of the present disclosure may be a crimped tow having a fineness appropriate for manufacturing smoking article filters and for securing their function. For example, the total fineness of the tow is a factor related to the amount of filament that can be fed into the filter wrapper. If the total fineness is excessively low, a sufficient amount of filament cannot be packed into the filter wrapper, resulting in lower draw resistance. And, if the total fineness is excessively high, the amount packed into the filter wrapper becomes too large, causing the filter wrapper to burst, or making it difficult to control the tow packing amount required to achieve the desired draw resistance for the filter.
In an embodiment, the single filament fineness of the filaments constituting the lyocell multifilament may be 1.5 to 8.0 denier. Here, the single filament fineness of the filaments refers to the denier of a single monofilament separated from the multifilament.
Specifically, the single filament fineness of the filaments may be, for example, 7.5 denier or less, 7.0 denier or less, 6.5 denier or less, 6.0 denier or less, 5.5 denier or less, 5.0 denier or less, 4.5 denier or less, 3.5 denier or less, or 3.0 denier or less. And, the lower limit of the single filament fineness of the filaments may be, for example, 2.0 denier or more, 2.5 denier or more, 3.0 denier or more, 3.5 denier or more, 4.0 denier or more, 4.5 denier or more, 5.0 denier or more, 5.5 denier or more, or 6.0 denier or more. Meeting the aforementioned range may be more advantageous for ensuring stable physical properties of a smoking article filter (e.g., achieving appropriate hardness or draw resistance) and maintaining reliable processing performance.
In an embodiment, the crimped lyocell multifilament may be a crimped tow having a total fineness of 15,000 to 45,000 denier. For example, the lower limit of the total fineness may be, for example, 16,000 or more, 16,500 or more, 17,000 or more, 17,500 or more, 18,000 or more, 18,500 or more, 19,000 or more, 19,500 or more, 20,000 or more, 20,500 or more, 21,000 or more, 21,500 or more, 22,000 or more, 22,500 or more, 23,000 or more, 23,500 or more, 24,000 or more, 24,500 or more, 25,000 or more, 25,500 or more, 26,000 or more, 26,500 or more, 27,000 or more, 27,500 or more, 28,000 or more, 28,500 or more, 29,000 or more, 29,500 or more, 30,000 or more, 30,500 or more, 31,000 or more, 31,500 or more, 32,000 or more, 32,500 or more, 33,000 or more, 33,500 or more, 34,000 or more, 34,500 or more, 35,000 or more, 35,500 or more, 36,000 or more, 36,500 or more, 37,000 or more, 37,500 or more, 38,000 or more 38,500 or more, 39,000 or more, 39,500 or more, 40,000 or more 40,500 or more, 41,000 or more, 41,500 or more, 42,000 or more, 42,500 or more, 43,000 or more, 43,500 or more, or 44,000 or more. And, the upper limit of the total fineness may be, for example, 44,500 or less, 44,000 or less, 43,500 or less, 43,000 or less, 42,500 or less, 42,000 or less, 41,500 or less, 41,000 or less, 40,500 or less, 40,000 or less, 39,500 or less, 39,000 or less, 38,500 or less, 38,000 or less, 37,500 or less, 37,000 or less, 36,500 or less, 36,000 or less, 35,500 or less, 35,000 or less, 34,500 or less, 34,000 or less, 33,500 or less, 33,000 or less, 32,500 or less, 32,000 or less, 31,500 or less, 31,000 or less, 30,500 or less, 30,000 or less, 29,500 or less, 29,000 or less, 28,500 or less, 28,000 or less, 27,500 or less, 27,000 or less, 26,500 or less, 26,000 or less, 25,500 or less, 25,000 or less, 24,500 or less, 24,000 or less, 23,500 or less, 23,000 or less, 22,500 or less, 22,000 or less, 21,500 or less, 21,000 or less, 20,500 or less, 20,000 or less, 19,500 or less, 19,000 or less, 18,500 or less, 18,000 or less, 17,500 or less, 17,000 or less, 16,500 or less, 16,000 or less, or 15,500 or less. If the total fineness of the tow falls outside the aforementioned range, the processability for manufacturing a smoking article filter deteriorates (making continuous processing impossible due to cutting issues), and if the amount of tow packed into the filter wrapper is too little or too much, it becomes difficult to secure adequate filter properties (e.g., hardness or draw resistance).
While the method for measuring denier is not particularly limited, one example is as follows. A 2 m sample is taken from the tow to be measured and is left for 24 hours to stabilize in a room maintained at a constant temperature of 20 °C and constant humidity of 65 %. One end of the stabilized tow is fixed, and a 2 kg weight is attached to the opposite end. The tow, in an elongated state due to the weight, is held for 5 seconds (to stabilize), then cut to a length of 90 cm to obtain a sample, and the weight of this sample is measured (total fineness). The denier is calculated by multiplying the measured weight by 10,000, according to the denier conversion method. The single filament fineness is calculated by dividing the total fineness by the number of filament strands.
The total fineness of the tow as described above can be determined by the single filament fineness of the filaments and the number of crimps. In the method of the present disclosure, because the single filament fineness and the number of crimps are controlled as described above, the aforementioned total fineness of the tow, which is suitable for manufacturing a smoking article filter and securing its function, may be ensured.
In an embodiment, the crimped lyocell multifilament may have from 20 to 50 crimps per inch. For example, the number of crimps may be 25 crimps/inch or more, 30 crimps/inch or more, 35 crimps/inch or more, 40 crimps/inch or more, or 45 crimps/inch or more, and its upper limit may be, for example, 45 crimps/inch or less, 40 crimps/inch or less, 35 crimps/inch or less, 30 crimps/inch or less, or 25 crimps/inch or less. The number of crimps and their uniformity may be controlled through the pressure and temperature conditions associated with the crimping process described below.
Although not particularly limited, the number of crimps may be measured, for example, according to the KS K 0326 standard. Specifically, a tow sample of 20 strands with undamaged crimps is taken, and using a 4 to 5 % cellulose nitrate in amyl acetate adhesive, single fiber strands are attached one by one to a pre-prepared strip of glossy paper (gauge length 25 mm) such that they are extended by 25 ± 5 %, and are then left to stand to allow the adhesive to dry. And, for this sample, the measurement may be performed by using a crimp tester to apply a preload corresponding to 1.96/1,000 cN per denier (=2 mgf) to each strand and determining the number of crimps within 25 mm. In this case, the number of crimps may be expressed as the upper and lower limits of the crimp counts measured for the 20 strands. Alternatively, the number of crimps may be expressed as the arithmetic mean of the crimp counts measured for the 20 strands.
Although not particularly limited, the lyocell material prepared as described above may be used for smoking article filters.
In an embodiment, the lyocell material may further include a binder. The binder, for example, may be present on the surface of the crimped lyocell multifilament, or between the crimped lyocell multifilaments (or monofilaments). The binder can further increase the hardness of a smoking article filter prepared with the tow, thereby preventing issues such as the filter getting stuck during the filter manufacturing process or the smoking article (e.g., cigarette) manufacturing process.
The type of binder that may be used is not particularly limited, and any known binder may be employed so long as it does not impair the objectives of the present disclosure. For example, a binder that can offer sufficient compatibility with the emulsion used in the present disclosure, improve the hardness of the filter, and provide excellent bonding strength may be utilized.
In an embodiment, the binder may include a polyester-based binder, a cellulose-based binder, and/or a vinyl-based binder.
Although not particularly limited, for the polyester-based binder, a polyester binder including one or more selected from the group consisting of alkylene, arylene, and heteroarylene having from 5 to 12 carbons, may be used.
As the cellulose-based binder, for example, hydroxypropyl methylcellulose (HPMC), ethylcellulose (EC) and/or methylcellulose (MC), carboxymethylcellulose (CMC), and the like may be used, but the disclosure is not limited thereto.
As the vinyl-based binder, polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), ethylene-vinyl acetate (EVAc), or the like may be utilized without being limited thereto.
A method for applying (coating) the binder to the lyocell material will be described below.
Another embodiment of the present disclosure relates to a method of preparing a lyocell material. Through this method, the aforementioned lyocell material for smoking article filters can be manufactured.
Furthermore, since the emulsion of the present disclosure also has high compatibility with binders, it enables the achievement of the physical properties (e.g., hardness or draw resistance) required in various smoking articles (e.g., cigarettes).
Specifically, the method of preparing the lyocell material includes treating a lyocell multifilament with an emulsion, and imparting crimp to the lyocell multifilament. In addition, the emulsion includes at least (a) an ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol, and (b) an ester of sorbitan and a fatty acid having 16 or more carbons.
The emulsion treatment may be performed, for example, by spraying the emulsion having the aforementioned composition onto the lyocell filaments, or by immersing the lyocell filaments in the emulsion. The method of the present disclosure, including the emulsion treatment, may be performed such that the emulsion content (e.g., OPU (wt%)) in the lyocell material satisfies a predetermined range, which is described below.
In addition, the crimp-imparting process may be performed, for example, by applying steam and/or pressure to the lyocell multifilament.
Details regarding the emulsion components are the same as previously described and are therefore omitted.
A method of preparing a lyocell material according to an embodiment of the present disclosure, which includes the emulsion treatment and crimp-imparting process, will be described in greater detail below. The method of the present disclosure may be carried out by including one or more processes described below.

Lyocell Dope Spinning Process (a)

This process involves spinning a lyocell spinning dope including lyocell cellulose (or cellulose pulp) and N-methylmorpholine-N-oxide (NMMO).
Commercialized cellulose acetate filters are identified as a major cause of microplastic generation. However, lyocell materials generate no pollutants during their production process, as the amine oxide-based solvents used in lyocell fiber manufacturing are recyclable and biodegradable upon disposal. Furthermore, because the lyocell tow biodegrades and is eliminated within a relatively short period, lyocell is a more eco-friendly material than cellulose acetate.
In an embodiment, the content of cellulose in the spinning dope may be 5 to 15 wt% based on 100 wt% of the total weight of the dope. If the content of cellulose is excessively low, achieving the characteristics of lyocell fibers is difficult, and if the content of cellulose exceeds the above range, dissolution in the solvent is difficult. Considering the foregoing, 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, and the upper limit 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.
In one example, the spinning dope may include an aqueous solution of N-methylmorpholine-N-oxide (NMMO). Considering factors such as the degree of dissolution of the cellulose and the process temperature, the aqueous solution may include, for example, 80 to 95 parts by weight of N-methylmorpholine-N-oxide and 5 to 20 parts by weight of water.
In one example, the cellulose or cellulose pulp may be one in which the content of alpha-cellulose is from 85 to 97 wt%, based on 100 wt% of the total cellulose.
In an embodiment of the present disclosure, the degree of polymerization (DPw) of the cellulose may be 600 to 1,700.
In the spinning process, the form of the spinneret used for extruding the spinning dope is not particularly limited. For example, a donut-shaped spinneret may be used.
The nozzle temperature of the spinneret, specifically the spinning temperature, may be appropriately selected by those skilled in the art. Considering that the viscosity of the spinning dope varies with spinning temperature and the extrusion may not proceed well, the spinning may be carried out, for example, at a spinning temperature in the range of 100 °C to 120 °C or less, or 100 °C to 110 °C or less.
In an embodiment, the process of spinning the spinning dope may be performed under controlled spinning conditions such that the single filament fineness of the filaments may be from 1.5 denier to 8.0 denier or less. For example, one or more spinning conditions among the extrusion rate and spinning speed of the spinning dope may be appropriately controlled so that the single filament fineness of filaments constituting the lyocell material satisfies 1.5 to 8.0 denier. Here, the single filament fineness refers to the denier of a single monofilament separated from a multifilament.
Specifically, the single filament fineness of the filaments may be, for example, 7.5 denier or less, 7.0 denier or less, 6.5 denier or less, 6.0 denier or less, 5.5 denier or less, 5.0 denier or less, or 4.5 denier or less. And, the lower limit of the single filament fineness of the filaments may be, for example, 2.0 denier or more, 2.5 denier or more, 3.0 denier or more, 3.5 denier or more, 4.0 denier or more, 4.5 denier or more, 5.0 denier or more, 5.5 denier or more, or 6.0 denier or more. Meeting the aforementioned range may be more advantageous for ensuring stable achievement of draw resistance in the smoking article filter and securing processability.
The spinning dope extruded through the spinneret may undergo a coagulation process described below.

Process of Coagulation and Obtaining Multifilaments (b)

In this process, the spun lyocell spinning dope may be coagulated, and lyocell multifilaments may be obtained.
The coagulation may be performed by bringing the spinning dope into contact with air and/or a coagulation liquid.
In an embodiment, the coagulation may include a first coagulation process of supplying cooling air to the spun lyocell dope, and a second coagulation process of introducing the spun dope, which has undergone the first coagulation, into a coagulation liquid for coagulation.
According to this coagulation method, the lyocell dope extruded from the spinneret may undergo a first coagulation in the space between the spinneret and a coagulation tank (air-gap section). In this air gap section, for example, cooling air may be supplied from an air cooling section located inside the spinneret, flowing from the inside toward the outside of the spinneret. In addition, the first coagulation may be carried out using so-called air-quenching methods or means known in the art.
In an embodiment, the upper temperature limit of cooling air used for the first coagulation may be, for example, 15 °C or less. Specifically, the cooling air may be air at 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 exceeds the aforementioned range, coagulation of the spinning dope by air is insufficient, and spinning-related processability is poor.
The lower temperature limit of the cooling air may be determined in consideration of spinning processability and/or cross-sectional uniformity of filaments. For example, when the temperature of cooling air is less than 4 °C, the surface of the spinneret cools, the surface of filaments becomes non-uniform, and spinning processability also deteriorates. Considering the foregoing, 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 the effects on filament properties. For example, the cooling air may be supplied at an airflow rate of 70 to 300 Nm³/h to the extruded spun dope. More specifically, the airflow rate may be 100 Nm³/h or more or 150 Nm³/h or more, and the upper limit of the airflow rate may be 250 Nm³/h or less or 200 Nm³/h or less.
After the first coagulation as described above, the cooled spun dope may be supplied to a coagulation tank or bath containing a coagulation liquid (second coagulation). For proper progress of the coagulation, the temperature of the coagulation liquid may, for example, be 30 °C or less, or 25 °C or less. And, 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 in this range, the coagulation rate may be appropriately maintained.
The type of coagulation liquid for the second coagulation as described above is not particularly limited. For example, the coagulation liquid may include one or more of water and N-methylmorpholine N-oxide (NMMO).
Although not particularly limited, when the coagulation liquid includes water and NMMO, the coagulation liquid may have a water content of 60 to 90 wt%, and a NMMO content of 10 to 40 wt%. Alternatively, the coagulation liquid may include 70 to 80 wt% of water and 20 to 30 wt% of NMMO. The concentration of such a coagulation liquid may be controlled using a sensor or the like so that it is maintained during the manufacturing process.

Washing Process (c)

If necessary, after the aforementioned process of coagulation and obtaining multifilaments, the multifilaments may be washed. Through this washing, any residual NMMO and/or other impurities within the filaments may be removed.
The method for performing the washing is not particularly limited. For example, the washing may be carried out by introducing the coagulated lyocell multifilaments into a washing bath using a take-up roller. Alternatively, the washing may be performed by spraying a washing liquid onto the multifilaments as they are conveyed to the next process by a take-up roller.
The components of the washing liquid are not particularly limited. For example, the washing liquid may include water, and may further include other known additives.
Additionally, in consideration of factors such as reuse after washing, the washing liquid may be used at a controlled temperature of 100 °C or less.

Emulsion Treatment Process (d)

This process involves applying an emulsion of the aforementioned components to the surface of the filaments. The emulsion treatment may reduce friction exerted on the filament and enable good crimp formation in the crimp-imparting process described below. When the emulsion treatment is to be carried out two or more times as described below, they may be referred to as first emulsion treatment and second emulsion treatment according to their sequence.
Although not particularly limited, the emulsion treatment may be performed by immersing multifilaments in a bath filled with emulsion so that the multifilaments are fully submerged. Alternatively, the emulsion treatment may be carried out by spraying emulsion liquid during the process of moving to the next process by take-up rollers.
To ensure that the amount of emulsion applied to the multifilaments after emulsion treatment as described above is uniform, a process may be additionally performed in which rolls positioned before and/or after the emulsion treatment process squeeze out emulsion from the surface of the multifilaments.
In an embodiment, the emulsion treatment may be performed such that the emulsion content (OPU: oil pick up ratio (wt%)) satisfies 2.0 wt% or more based on 100 wt% of the multifilaments having undergone at least one emulsion treatment. In this context, the multifilaments having undergone at least one emulsion treatment refer to, for example, lyocell multifilaments to which first emulsion treatment has been applied, lyocell multifilaments to which both first and second emulsion treatments (see below for details) have been applied, or lyocell multifilaments to which the aforementioned emulsion treatment(s) as well as binders described below have been applied. Further, the lyocell multifilaments having undergone the emulsion and/or binder treatment as described above may also be crimped.
Specifically, the emulsion content in the multifilaments having undergone at least one emulsion treatment may be 0.5 wt% or more, 0.6 wt% or more, 0.62 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, and specifically, 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. Furthermore, the upper limit of the emulsion content 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, 10.0 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, 7.6 wt% or less, 7.5 wt% or less, 7.0 wt% or less, or 6.5 wt% or less. Here, the content may refer to the dry weight after evaporation of solvents (e.g., water) or liquid components that may be included in the emulsion.
Based on 100 wt% of the emulsion-treated multifilament, the content of the emulsion (OPU: oil pick up ratio (wt%)) may be 0.6 wt% to 7.5 wt%, or 0.62 wt% to 7.5 wt%, preferably 4.5 wt% to 7.0 wt%, and more preferably 4.9% to 6.0 wt%.
The emulsion having the aforementioned composition, when applied within the aforementioned content range, may compensate for the hydrophilic properties of the lyocell material, and as will be described below, may enable the electrostatic properties measured from the lyocell material to be controlled.
In some cases, drying of the emulsion may be performed after the emulsion treatment as described above.
In an embodiment of the present disclosure, one or more of the aforementioned processes may be controlled such that the single filament fineness of the filaments constituting the lyocell multifilament is 1.5 to 8.0 denier. The single filament fineness of the filaments refers to the fineness of a single monofilament separated from the multifilament.
Specifically, the single filament fineness of the filaments may be, for example, 7.5 denier or less, 7.0 denier or less, 6.5 denier or less, 6.0 denier or less, 5.5 denier or less, 5.0 denier or less, or 4.5 denier or less. Furthermore, the lower limit of the single filament fineness of the filaments may be, for example, 2.0 denier or more, 2.5 denier or more, 3.0 denier or more, 3.5 denier or more, 4.0 denier or more, 4.5 denier or more, 5.0 denier or more, 5.5 denier or more, or 6.0 denier or more. Meeting the aforementioned range may be more advantageous for ensuring stable achievement of draw resistance in the smoking article filter and securing processibility.
Although not particularly limited, the process controlled to secure the aforementioned single filament fineness range may be the aforementioned spinning process. Alternatively, all of the aforementioned spinning, coagulation, washing, and emulsion treatment processes may be controlled to secure the aforementioned single filament fineness range.

Crimp-Imparting Process (e)

The crimp-imparting process involves obtaining a crimped tow by applying steam and/or pressure via a roller to the emulsion-treated lyocell multifilament, and may be referred to as a so-called crimping process.
Through crimping, the multifilament may be imparted with waves, and the fiber may acquire a bulky characteristic. Crimping may be performed using known crimp machines such as those including a stuffer box and/or steam box, and usable crimp machines are not particularly limited as long as they can apply the steam pressure and roll pressure described below.
In an embodiment, the crimp-imparting process may be carried out by first supplying steam to the lyocell multifilament to preheat and swell the multifilament, followed by pressing the multifilament with a press roller to form wrinkles in the multifilament. In this case, a steam box may be used for steam supply, and such a steam box may be positioned upstream of the crimp machine.
In an embodiment, the crimp-imparting process may be carried out in such a way that the pressing of the multifilament with a press roller and the supply of steam occur simultaneously.
In an embodiment, the crimp-imparting process may be performed by first supplying steam to the lyocell multifilament to preheat and swell the lyocell multifilament, followed by simultaneously pressing the multifilament with press rollers and applying steam.
In an embodiment, the crimp-imparting process may be performed by applying steam at 0.1 to 2.0 kgf/cm² to the multifilament before it is fed into the crimp machine (specifically, a press roller). In an embodiment of the present disclosure, steam at 0.2 kgf/cm² or more, 0.3 kgf/cm² or more, 0.4 kgf/cm² or more, 0.5 kgf/cm² or more, or 0.6 kgf/cm² or more may be provided by a steam box. Additionally, steam at 1.5 kgf/cm² or less, 1.4 kgf/cm² or less, 1.3 kgf/cm² or less, 1.2 kgf/cm² or less, 1.1 kgf/cm² or less, or 1.0 kgf/cm² or less may be provided. When the steam supply amount or pressure is below the aforementioned range, crimps may not be formed smoothly. When the steam supply amount or pressure exceeds the aforementioned range, the filaments may become overly flexible in the crimp machine, resulting in excessive crimp that prevents the filaments from passing through the crimp machine.
In an embodiment, the crimp-imparting process may be performed while applying a pressure of 1.5 to 4.0 kgf/cm² to the multifilament fed into the crimp machine by using a roller. In an embodiment of the present disclosure, a pressure of 1.6 kgf/cm² or more, 1.7 kgf/cm² or more, 1.8 kgf/cm² or more, 1.9 kgf/cm² or more, 2.0 kgf/cm² or more, 2.1 kgf/cm² or more, 2.2 kgf/cm² or more, 2.3 kgf/cm² or more, 2.4 kgf/cm² or more, or 2.5 kgf/cm² or more may be applied to the multifilament via a press roller. Additionally, a pressure of 3.9 kgf/cm² or less, 3.8 kgf/cm² or less, 3.7 kgf/cm² or less, 3.6 kgf/cm² or less, 3.5 kgf/cm² or less, 3.4 kgf/cm² or less, 3.3 kgf/cm² or less, 3.2 kgf/cm² or less, 3.1 kgf/cm² or less, 3.0 kgf/cm² or less, 2.9 kgf/cm² or less, 2.8 kgf/cm² or less, 2.7 kgf/cm² or less, 2.6 kgf/cm² or less, or 2.5 kgf/cm² or less may be applied. If the pressure by the roller is below the aforementioned range, the intended number of crimps may not be fully formed. If the roller pressure exceeds the aforementioned range, the pressing force may be excessively high, preventing the filaments from entering the crimp machine smoothly or passing through the stuffer box. Wrinkles may be formed in the multifilament by the press roller providing the aforementioned pressure.
In an embodiment, the crimp-imparting process may employ a doctor blade that applies a predetermined pressure to the multifilament. The doctor blade controls the residence time of the filaments fed into the crimper stuffer box, thereby contributing to imparting the number of crimps (which affects the quality of the tow and the filter performance). Such a doctor blade may be positioned, for example, in the travel path of the multifilament discharged from the roller pressing point after being pressed by the aforementioned roller.
In an embodiment of the present disclosure, the crimp-imparting process may be performed by applying a pressure of 0.1 to 2.0 kgf/cm² to the multifilament that has passed through the roller of the crimp machine, using a doctor blade. More specifically, the pressure applied by the doctor blade may be 0.2 kgf/cm² or more, 0.3 kgf/cm² or more, 0.4 kgf/cm² or more, or 0.5 kgf/cm² or more. Additionally, the upper limit of the pressure may be, for example, 1.5 kgf/cm² or less, 1.4 kgf/cm² or less, 1.3 kgf/cm² or less, 1.2 kgf/cm² or less, 1.1 kgf/cm² or less, or 1.0 kgf/cm² or less.
In an embodiment, the crimp-imparting process may be performed at a temperature in the range of 120 to 250 °C. When the temperature is excessively low, the shape stabilization effect of crimps may become poor, and when the temperature is excessively high, the concentration of oil components in the stuffer box increases, making crimp formation difficult. Therefore, considering the aforementioned steam pressure and other factors, the temperature may be suitably controlled in the range of 130 °C or more, 140 °C or more, or 150 °C or more, and 200 °C or less, 180 °C or less, or 160 °C or less.

Binder Treatment Process (f)

In an embodiment, the method may further include coating a binder onto the emulsion-treated lyocell multifilament or the lyocell multifilament obtained by the crimp-imparting process (i.e., a crimped tow).
When manufacturing a smoking article filter from a tow, a binder is used. The binder may increase the hardness of the smoking article filter produced from the tow, thereby preventing issues such as the filter being jammed during the filter manufacturing process or the cigarette manufacturing process.
The method of coating binder onto the lyocell crimped tow is not particularly limited. For example, an emulsion treatment can be performed by immersing the crimped tow in a bath filled with binder (or binder solution) so that the multifilament can be completely submerged in the binder. Alternatively, the binder coating can be performed by spraying (or atomizing) the binder (or binder solution) through a nozzle.
Details regarding the types of usable binders and their components are the same as previously described and are therefore omitted.
In an embodiment, the binder (or binder solution) may further include a solvent in addition to the aforementioned components. The solvent may include, for example, water, ethanol, propylene glycol, and/or glycerin, but is not limited thereto. If the binder (or binder solution) contains a solvent, the solvent content may be, for instance, about 20 to 80 wt%, or about 40 to 60 wt%, based on 100 wt% of the entire binder (or binder solution).
The binder treatment may be carried out to the extent necessary to achieve the aforementioned objectives of the binder treatment. For example, the binder treatment may be performed so that the binder content is 20 wt% or less, for example, in a range of 8 to 15 wt%, based on 100 wt% of the multifilament that has been treated with the emulsion and the binder. Here, the content may refer to the dry weight after evaporation of solvents or liquid components that may be included in the binder.
Once the binder is coated onto the crimed tow, drying of the binder may be performed. Although the drying temperature is not particularly limited, the drying may be carried out, for example, at room temperature (about 10 to 35 °C).

Other Processes (g)

After the crimp-imparting process, an appropriate post-treatment may be further performed.
In an embodiment, a second emulsion treatment (g1) may be additionally performed. The second emulsion treatment can prevent the generation of static electricity on the tow and can impart flexibility to the tow. The second emulsion treatment may be performed in a manner identical or analogous to the emulsion treatment process (d) described above.
Specifically, the second emulsion treatment may be performed by applying an emulsion to the lyocell tow that has undergone a process by a crimper. This may function advantageously in various processes involved in manufacturing a smoking article filter. For example, the second emulsion treatment not only allows the fibers and filters to spread easily with air during the spreading process, but also prevents fiber breakage during the stretching process as the molecular chains of the emulsion bind the lyocell filaments. Achieving these benefits requires using components derived from fatty acids having a predetermined number of carbons or more, as described above.
The second emulsion treatment may be carried out either before or after the binder treatment. Alternatively, the second emulsion treatment may be performed regardless of whether there is a binder treatment.
Even if the second emulsion treatment as described above is performed, the second emulsion treatment process may be carried out such that the emulsion content or OPU content in the material falls within the above-described range.
In an embodiment, a drying treatment (g2) may be additionally performed. The drying may be carried out, for example, at a temperature in the range of 100 to 130 °C. The drying method or procedure is not particularly limited, and any known technique may be employed. For example, the drying may be carried out by applying hot air to the tow, or by passing the tow through, or allowing the tow to remain in, a temperature-controlled room for a certain period of time.
According to an embodiment of the present disclosure, a tow may be provided on which from 20 to 50 crimps per inch are formed by a method including the crimp-imparting process as described above. For example, the number of crimps may be 25 crimps/inch or more, 30 crimps/inch or more, 35 crimps/inch or more, 40 crimps/inch or more, or 45 crimps/inch or more, and the upper limit thereof may be, for example, 45 crimps/inch or less, 40 crimps/inch or less, 35 crimps/inch or less, 30 crimps/inch or less, or 25 crimps/inch or less. The number of crimps and its uniformity may be controlled through pressure and temperature conditions associated with the crimping process described above.
The preparation method of the present disclosure can provide a tow having a fineness appropriate for manufacturing a smoking article filter and securing its function. The total fineness of the tow is a factor related to the amount of filaments that can be fed into the interior of a filter wrapper. If the total fineness is excessively low, a sufficient amount of filaments cannot be filled into the filter wrapper, resulting in lower draw resistance. Conversely, if the total fineness is excessively high, the amount filled into the filter wrapper becomes too large, which may cause the filter wrapper to burst, and it also becomes difficult to make adjustments to the tow filling amount needed to achieve the draw resistance required for the filter. In this regard, according to an embodiment of the present disclosure, a crimped tow having a total fineness of 15,000 to 45,000 denier may be provided. For example, the lower limit of the total fineness may be, for example, 16,000 or more, 17,000 or more, 18,000 or more, 19,000 or more, or 20,000 or more, and the upper limit thereof may be, for example, 40,000 or less, 35,000 or less, 30,000 or less, or 25,000 or less. More specific numerical values are as described above. If the total fineness of the tow falls outside the aforementioned range, the processibility for manufacturing a smoking article filter deteriorates (making continuous processing impossible due to cutting issues). In addition, during the production of the smoking article filter, if the amount of tow filled into the filter wrapper becomes too little or too much, achieving adequate filter properties (e.g., draw resistance) becomes difficult.
The total fineness of the tow as described above may be determined by the single filament fineness and the number of crimps of the filaments. In the method of the present disclosure, because the single filament fineness and the number of crimps are controlled as described above, the aforementioned total fineness of the tow, which is suitable for manufacturing a smoking article filter and securing its function, can be obtained.
Although not particularly limited, the lyocell material prepared by the aforementioned method may be used in a smoking article filter.
Another embodiment of the present disclosure relates to a smoking article filter. The smoking article filter may include a lyocell material, and the lyocell material may be the same as described above.
Specifically, the smoking article filter of the present disclosure is a smoking article filter including a lyocell material, wherein the lyocell material includes a crimped lyocell multifilament, and an emulsion coated on the lyocell multifilament. In addition, the emulsion includes at least (a) an ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol, and (b) an ester of sorbitan and a fatty acid having 16 or more carbons.
In addition, the lyocell material includes the emulsion in a content of 0.1 wt% or more based on 100 wt% of the entire lyocell material. The descriptions regarding the components and amounts of the emulsion in embodiments of the present disclosure are the same as those described above.
In an embodiment, the single filament fineness of the filaments constituting the lyocell multifilament may be 1.5 to 8.0 denier. The specific numerical values are the same as those described above.
In an embodiment, the crimped lyocell multifilament may be a crimped tow having a total fineness of 15,000 to 45,000 denier. The specific numerical values are the same as those described above.
In an embodiment, the crimped lyocell multifilament may have 20 to 50 crimps per inch. The specific numerical values are the same as those described above.
In an embodiment, the smoking article filter may further include a binder on the surface of the crimped lyocell multifilament or between the crimped lyocell multifilaments. The binder increases the hardness of the smoking article filter produced from the tow, thereby preventing problems such as the filter being jammed during the filter manufacturing process or the cigarette manufacturing process. The description regarding the types, components, and content of usable binders is the same as described above.
In an embodiment, the smoking article filter may further include a wrapper (which may be referred to as wrapping paper, filter paper, or filter wrapper). For example, the wrapper may be a porous paper or a non-porous paper that can wrap around the aforementioned lyocell tow (i.e., a tow that has been treated with emulsion at least once and crimped) and maintain the filter shape (e.g., a cylinder or a circular tube).
In an embodiment, if a porous wrapper is used, the wrapper may have a porosity of 10 to 50,000 Coresta Unit (CU). Specifically, the lower limit of the porosity of the wrapper may be, for example, 1,000 CU or more, 5,000 CU or more, 10,000 CU or more, 15,000 CU or more, 20,000 CU or more, 25,000 CU or more, 30,000 CU or more, 35,000 CU or more, 40,000 CU or more, or 45,000 CU or more, and may have an upper limit of, for example, 45,000 CU or less, 40,000 CU or less, 35,000 CU or less, 30,000 CU or less, 25,000 CU or less, or 20,000 CU or less. In an embodiment of the present disclosure, the wrapper may have a porosity in the range of 22,000 to 26,000 CU, or 23,000 to 25,000 CU.
In an embodiment, the wrapper may have a basis weight of 15 to 60 g/cm². Specifically, 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 may have an upper limit of, 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 an embodiment of the present disclosure, 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.
In an embodiment of the present disclosure, the smoking article filter may have a predetermined shape and size.
For example, the filter may have a rod shape. More specifically, the smoking article filter may have a cylindrical shape.
In addition, the filter may have, for example, a length of 10 to 50 mm. Specifically, the lower limit of the length of the filter may be 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 an embodiment of the present disclosure, the filter having such a length may have a circular cross-section, and the circumference of the circular cross-section may be 10 to 40 mm. For example, the circumference of the filter may have a lower limit of 15 mm or more, 20 mm or more, 25 mm or more, 30 mm or more, or 35 mm or more, and 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 may have a rod shape. More specifically, the smoking article filter may have a cylindrical shape.
In addition, the filter may have, for example, a length of 10 to 50 mm. Specifically, the lower limit of the length of the filter may be 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 an embodiment of the present disclosure, the filter having such a length may have a circular cross-section, and the circumference of the circular cross-section may be 10 to 40 mm. For example, the circumference of the filter may have a lower limit of 15 mm or more, 20 mm or more, 25 mm or more, 30 mm or more, or 35 mm or more, and 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.
In an embodiment, the smoking article filter may include a lyocell tow (i.e., a crimped lyocell multifilament), an emulsion coated on the lyocell multifilament, and a filter wrapper. Details regarding the lyocell tow and the emulsion are the same as previously described and are therefore omitted.
The wrapper may be a porous paper or a non-porous paper that can wrap around the aforementioned lyocell tow (i.e., a tow that has been treated with emulsion at least once and crimped) and maintain the filter shape (e.g., a cylinder or a circular tube).
In an embodiment, if a porous wrapper is used, the wrapper may have a porosity of 10 to 50,000 Coresta Unit (CU). Specifically, the porosity of the wrapper may have a lower limit of, for example, 1,000 CU or more, 5,000 CU or more, 10,000 CU or more, 15,000 CU or more, 20,000 CU or more, 25,000 CU or more, 30,000 CU or more, 35,000 CU or more, 40,000 CU or more, or 45,000 CU or more, and may have an upper limit of, for example, 45,000 CU or less, 40,000 CU or less, 35,000 CU or less, 30,000 CU or less, 25,000 CU or less, or 20,000 CU or less. In an embodiment of the present disclosure, the wrapper may have a porosity in the range of 22,000 to 26,000 CU, or 23,000 to 25,000 CU.
In an embodiment, the wrapper may have a basis weight of 15 to 60 g/cm². Specifically, the basis weight of the wrapper may have a lower limit of, 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 may have an upper limit of, 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 an embodiment of the present disclosure, 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. Specifically, the weight of the filter may have a lower limit of, for example, 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.
Other descriptions regarding the smoking article filter or the materials included therein are the same as described above, and are omitted herein.
Another embodiment of the present disclosure relates to a method of preparing a smoking article filter. The method is for preparing the lyocell-based smoking article filter described above and includes the aforementioned method of preparing the lyocell material.
Specifically, the method of preparing a smoking article filter according to the present disclosure may be a method including: treating a lyocell multifilament with an emulsion; imparting crimps to the lyocell multifilament; and manufacturing a filter using the crimped lyocell multifilament.
Furthermore, in the method, the emulsion applied to the multifilament includes (a) an ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol, and (b) an ester of sorbitan and a fatty acid having 16 or more carbons.
Additionally, according to an embodiment of the present disclosure, the lyocell multifilaments included in the smoking article filter include the emulsion in a content of 0.1 wt% or more, based on 100 wt% of the total lyocell multifilaments. In this context, the lyocell multifilaments included in the smoking article filter refer to lyocell multifilaments having undergone at least one emulsion treatment, and for example, may be lyocell multifilaments to which first emulsion treatment has been applied, lyocell multifilaments to which both first and second emulsion treatments have been applied, or lyocell multifilaments to which the aforementioned emulsion treatment(s) as well as binders described below have been applied. Further, the lyocell multifilaments that have undergone the emulsion and/or binder treatment as described above may also be crimped. The specific numerical values regarding the emulsion content are as described above.
With respect to the method of preparing a smoking article filter, the remaining processes, excluding the step of manufacturing the filter, are the same as the processes described above for the lyocell material, and a description thereof will not be repeated here. Furthermore, any description redundant with the foregoing is omitted.
The process of preparing the filter may be suitably performed by those skilled in the art according to known methods. For example, the filter may be prepared by forming a wrapper filled with tow into a rod shape. Alternatively, the filter may be prepared by cutting a rod-shaped filter paper filled with tow to an appropriate length. Details regarding the wrapper are as previously described.
Although not particularly limited, before the tow is filled into the filter paper, an opening process or a plasticizer treatment for the tow may be additionally performed.
Another embodiment of the present disclosure relates to a smoking article including a lyocell material. The lyocell material has a configuration and/or properties as described above, and a detailed description thereof is omitted.
Another embodiment of the present disclosure relates to a smoking article including a smoking article filter. The smoking article filter has a configuration and/or properties as described above, and a detailed description thereof is omitted.
Another embodiment of the present disclosure relates to an emulsion that can be applied (e.g., coated) to a lyocell tow. The emulsion of the present disclosure can overcome the surface hydrophilicity of a lyocell material for a smoking article filter and can control the surface electrostatic properties of the lyocell material.
In an embodiment of the present disclosure, the emulsion includes (a) an ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol, and (b) an ester of sorbitan and a fatty acid having 16 or more carbons. In another embodiment, the emulsion may further include, as component (c), an alkylene oxide adduct of the aforementioned component (b).
The specific description regarding each component included in the emulsion is the same as described above, and is therefore omitted.

Friction Method

In an exemplary lyocell material for a smoking article filter, the electrostatic value may be measured by a friction method. The friction method may be a method of measuring the static electricity generated from the lyocell material by means of friction. The electrostatic value measured by the friction method is used to predict characteristics of the lyocell material, for example, its spreading characteristics, which in turn can be used to predict whether the material is suitable for filter manufacturing.
For example, the friction method may be performed immediately after the manufacturing of the lyocell material, or may be performed after the lyocell material has undergone a pretreatment process. Specifically, the friction method may be performed after the lyocell material has been dried for a predetermined period of time. Additionally, the friction method may be performed after exposing the lyocell material to constant temperature and humidity conditions for a predetermined period of time.
For example, the lyocell material may be dried for 1 hour or more under a temperature condition of 100 °C or more. Additionally, the lyocell material may be exposed for 1 hour or more under a temperature condition of 20 °C or more. The lyocell material may be exposed for 1 hour or more under a humidity condition of 35 %RH or more.
Therefore, in an embodiment, the friction method may be a method of measuring the static electricity generated from a dried lyocell material. Additionally, the friction method may be a method of measuring the static electricity generated under a temperature condition of about 21 °C. Additionally, the friction method may be a method of measuring the static electricity generated under a humidity condition of about 35 %RH.
Meanwhile, the friction for generating static electricity may occur under a condition in which at least a portion of the lyocell material is pressed. Additionally, in a non-limiting example, the pressing of the lyocell material may be performed by the load of an abrasion wheel. For example, the load applied to at least a portion of the lyocell material may be about 200 g to about 300 g, and specifically, may be about 250 g.
For example, the abrasion wheel may be an elastic abrasion wheel. Additionally, the number of abrasive particles per unit area of the abrasion wheel may be about 1,400 to about 1,500. As an example of the abrasion wheel, CS10 from Taber Industries may be considered.
Meanwhile, the friction between the lyocell material and the abrasion wheel may be generated by the rotation of the lyocell material, and it may also be generated by the rotation of the abrasion wheel. Additionally, the lyocell material or the abrasion wheel may be rotated at about 40 cycle/min to about 80 cycle/min. Specifically, the lyocell material or the abrasion wheel may be rotated at about 60 cycle/min. Rotation of the lyocell material and/or rotation of the abrasion wheel may generate friction between the lyocell material and the abrasion wheel. Additionally, by means of the friction, static electricity may be induced on and measured from the surface of the lyocell material.
Meanwhile, the static electricity generated immediately after the lyocell material or the abrasion wheel has been rotated about 5 to about 50 times may be measured. Specifically, the static electricity may be measured immediately after the lyocell material or the abrasion wheel has been rotated about 10 to about 30 times.
Meanwhile, the static electricity of the lyocell material is measured by an electrostatic fieldmeter, and the electrostatic fieldmeter may be spaced apart from the lyocell material. Specifically, the electrostatic fieldmeter may be disposed on one surface of the lyocell material. Furthermore, the long axis of the electrostatic fieldmeter and a virtual plane parallel to the direction of rotation of the lyocell material may intersect each other. More specifically, the long axis of the electrostatic fieldmeter and a virtual plane parallel to the direction of rotation of the lyocell material may be perpendicular to each other.
Meanwhile, the electrostatic fieldmeter may be spaced apart from the lyocell material by about 0.1 cm to about 10 cm, and specifically, may be spaced apart by about 5 cm.
Meanwhile, as an example of the electrostatic fieldmeter, the FMX-004 from SIMCO-ION may be considered.

Advantageous Effects of Invention

The present disclosure provides a lyocell material for smoking article filters capable of replacing commercially available cellulose acetate (CA), and a smoking article filter including the lyocell material. Specifically, the present disclosure not only provides a lyocell material having excellent manufacturing processability and uniformity, but also has the inventive effect of improving the filtration capability and the physical properties of a smoking article (e.g., a cigarette).

Mode for the Invention

The operation and effects of the disclosure will be described in detail through specific embodiments set forth below. However, these embodiments are presented by way of example only and shall not be construed to limit the scope of the disclosure in any manner.
The lyocell material was prepared according to the process described in the following Preparation Example. Unless otherwise specified, the conditions used were within the scope of the foregoing description.

Preparation Example

A cellulose pulp with a degree of polymerization (DPw) of 820 and an alpha-cellulose content of 93.9% was mixed into an NMMO/H₂O solvent containing 0.01 wt% of propyl gallate to prepare a spinning dope with a concentration of 11 wt% for tow preparation. Then, at the spinning nozzle, the spinning dope was spun while maintaining a spinning temperature of 110 °C and appropriately controlling the extrusion amount and spinning speed.
The spinning dope, extruded from the spinning nozzle in the form of filaments, passed through an air gap section and was supplied to a coagulation liquid (a coagulation liquid containing 75 wt% of water and 25 wt% of NMMO, at a temperature of about 25 °C) in a coagulation tank. In this step, cooling air in the air-gap section, at a temperature of 8 °C and a flow rate of 200 Nm³/h, performs a first coagulation of the spinning dope. Additionally, using a sensor and a refractometer, the concentration of the coagulation liquid was continuously monitored.
The coagulated lyocell filaments were then washed. Specifically, the filament was fed to a take-up roller, and residual NMMO in the filament was removed with a washing liquid sprayed from a washing apparatus. The washed filament was then immersed in a bath designed with a predetermined emulsion concentration.
The filament was subjected to a pressure of 19.6 N/cm² (2 kgf/cm²) by a nip roll installed at the bath outlet and was then fed into a crimp machine for wrinkle formation. Specifically, the tow was prepared by supplying a steam pressure of 0.5 kgf/cm² to the steam box, while setting the roller pressure of the crimp machine to 2.5 kgf/cm² and the pressure of a doctor blade to 0.5 kgf/cm².
To impart anti-static properties and flexibility, the prepared tow was subjected to a second emulsion treatment and, immediately thereafter, passed through a continuous dryer set at 120 °C to obtain the dried tow product.
The prepared tow has a single filament fineness of 3.0 to 3.5 denier, a total fineness of 36,000 to 40,000 denier, and a crimp count of 25 to 35 crimps/inch.
For reference, the type (composition) of the emulsion and/or the degree of emulsion treatment (O.P.U.) in each of Examples and Comparative Examples were different as described below.

Example 1

The emulsion-treated lyocell tow from the Preparation Example was used. However, the emulsion used in the tow preparation contained about 60 wt% of isotridecyl stearate, about 22 wt% of sorbitan monooleate, about 16 wt% of polyoxyethylene sorbitan monooleate, and a residual amount of water, and the OPU was 0.62 wt%.

Example 2

The lyocell tow was prepared in the same manner as in Example 1, except that the OPU was 4.20 wt%.

Example 3

The lyocell tow was prepared in the same manner as in Example 1, except that the OPU was 4.90 wt%.

Example 4

The lyocell tow was prepared in the same manner as in Example 1, except that the OPU was 6.00 wt%.

Comparative Example 1

The lyocell tow was prepared in the same manner as in Example 1, except that the OPU was 7.60 wt%.

<Experiment 1: Evaluation of Electrostatic Properties of Pre-treated Lyocell Tow>

The lyocell tows prepared according to Examples 1 to 4 and Comparative Example 1 were each left to stand for 24 hours under conditions of a temperature of 21 °C and a humidity of 35 %RH. Thereafter, each lyocell tow was mounted on a Taber abrasion tester, and a CS10 from Taber was used as the abrasion wheel.
The load applied to the lyocell tow was 250 g, the rotation speed of the lyocell tow was 60 cycles/min, and the lyocell tow was rotated 10 or 30 times.
An electrostatic field meter (FMX-004 from SIMCO-ION) was positioned over one surface of the lyocell tow, and the lyocell tow and the electrostatic field meter were spaced apart from each other by about 5 cm. The static electricity measured by the electrostatic field meter is shown in Table 1 below.
Separately, to simulate the filter manufacturing process, the lyocell tow for each Evaluation Example in Table 1 was opened using first to third air spreaders, and the spreading properties of the lyocell material were evaluated while the opened lyocell tow was conveyed by transport rolls. The evaluation of the spreading properties of the lyocell material was performed by visual inspection; specifically, the spreading properties were rated as moderate or poor if the lyocell tow opened non-uniformly in terms of thickness and/or width, such that clumping of the emulsion or clumping of the lyocell multifilaments was observed.

Furthermore, if the opening of the lyocell material was so insufficient as to make further processing impossible, the spreading properties of the lyocell material were rated as poor.

[Table 1]

Evaluation Examples	Subject of Evaluation	Number of Rotations	Static Electricity (kV)	Spreading Properties
Evaluation Example 1	Example 1	10	0.21	Good
Evaluation Example 2	Example 1	30	0.18	Good
Evaluation Example 3	Example 2	10	0.16	Good
Evaluation Example 4	Example 2	30	0.12	Good
Evaluation Example 5	Example 3	10	0.15	Good
Evaluation Example 6	Example 3	30	0.12	Good
Evaluation Example 7	Example 4	10	0.13	Good
Evaluation Example 8	Example 4	30	0.10	Good
Evaluation Example 9	Comparative Example 1	10	0.08	Poor
Evaluation Example 10	Comparative Example 1	30	0.08	Poor

Referring to Table 1 above, it was confirmed that the electrostatic value of the lyocell material of Comparative Example 1, measured according to the friction method at 25 °C and 35 % RH, was merely 0.08 kV. Furthermore, the lyocell material of Comparative Example 1, which had a electrostatic value of 0.08 kV, was evaluated as having 'poor' spreading properties. Specifically, according to Evaluation Examples 9 and 10, the formation of voids of 20% or more was visually observed within the lyocell material of Comparative Example 1 during the opening process by the air spreaders. Moreover, it was confirmed that the lyocell material of Comparative Example 1, during the gathering process by the TTJ, failed to converge into a bundle corresponding to the diameter of the filter wrapper.

<Experiment 2: Evaluation of Electrostatic Properties of Dried Lyocell Tow>

The lyocell tows prepared according to Examples 1 to 4 and Comparative Example 1 were each dried for about 1 hour at about 105°C. Thereafter, each lyocell tow was mounted on a Taber abrasion tester, and a CS10 from Taber was used as the abrasion wheel.
The load applied to the lyocell tow was 250 g, the rotation speed of the lyocell tow was 60 cycles/min, and the lyocell tow was rotated 10 or 30 times.
An electrostatic field meter (FMX-004 from SIMCO-ION) was positioned over one surface of the lyocell tow, and the lyocell tow and the electrostatic field meter were spaced apart from each other by about 5 cm. The static electricity measured by the electrostatic field meter is shown in Table 2 below.

Separately, to simulate the filter manufacturing process, the lyocell tow for each Evaluation Example in Table 2 was opened, and the spreading properties of the opened lyocell tow were evaluated. The spreading properties were rated as poor if the lyocell tow opened non-uniformly in terms of thickness and/or width, or if ply was observed during the process of manufacturing a filter from the lyocell tow.

[Table 2]

Evaluation Examples	Subject of Evaluation	Number of Rotations	Static Electricity (kV)	Spreading Properties
Evaluation Example 11	Example 1	10	0.30	Good
Evaluation Example 12	Example 1	30	1.02	Moderate
Evaluation Example 13	Example 2	10	0.50	Good
Evaluation Example 14	Example 2	30	1.05	Moderate
Evaluation Example 15	Example 3	10	0.40	Good
Evaluation Example 16	Example 3	30	0.60	Good
Evaluation Example 17	Example 4	10	0.16	Good
Evaluation Example 18	Example 4	30	0.57	Good
Evaluation Example 19	Comparative Example 1	10	0.41	Good
Evaluation Example 20	Comparative Example 1	30	1.14	Poor

Referring to Table 2 above, it is confirmed that the electrostatic value of the lyocell material of Comparative Example 1, measured according to the friction method after being dried for about 1 hour at 105 °C, is 1.14 kV. Furthermore, the lyocell material of Comparative Example 1, which had a electrostatic value of 1.14 kV, was evaluated as having particularly poor spreading properties.
Specifically, according to Evaluation Example 20, the formation of voids of 20 % or more was visually observed within the lyocell material of Comparative Example 1 during the opening process by the air spreaders. Moreover, according to Evaluation Example 20, in the case of the lyocell material of Comparative Example 1, it was confirmed that during the gathering process by the TTJ, the lyocell material failed to converge into a bundle corresponding to the diameter of the filter wrapper, and that excessive voids were formed within the lyocell material.
Additionally, according to Table 2, the evaluation results of the electrostatic value and spreading properties with an increased number of rotations showed that the lyocell materials according to Examples 3 and 4 had the most stable electrostatic properties.
From Tables 1 and 2 above, it is confirmed that the spreading properties of the lyocell material deteriorate when the electrostatic value measured from the lyocell material is 0.08 kV or less, or 1.14 kV or more. On the other hand, it was confirmed that the lyocell materials according to Examples 1 to 4, when compared to the lyocell material of Comparative Example 1, exhibit a smaller change in electrostatic value due to friction, and maintain good or moderate spreading properties even under harsh conditions.

Claims

A lyocell material for a smoking article filter, the lyocell material including:
a crimped lyocell multifilament; and an emulsion coated on at least a portion of the lyocell multifilament,

wherein an electrostatic value measured from the lyocell material is 0.01 kV to 1.4 kV.
The lyocell material of claim 1,
wherein the electrostatic value is measured by a friction method.
The lyocell material of claim 2,
wherein the friction method is a method of measuring static electricity generated from the lyocell material by means of friction.
The lyocell material of claim 3,
wherein the friction occurs under a condition in which at least a portion of the lyocell material is pressed.
The lyocell material of claim 1,
wherein the emulsion includes (a) an ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol, and (b) an ester of sorbitan and a fatty acid having 16 or more carbons.
The lyocell material of claim 1,
wherein the emulsion includes 20 to 60 parts by weight of (b) an ester of sorbitan and a fatty acid having 16 or more carbons, per 100 parts by weight of the ester (a) of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol.
The lyocell material of claim 1,
wherein the emulsion further includes (c) an alkylene oxide adduct of the ester (b).
The lyocell material of claim 1,
wherein the emulsion includes 10 to 50 parts by weight of the alkylene oxide adduct (c) of the ester (b), per 100 parts by weight of the ester (a) of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol.
The lyocell material of claim 1,
wherein the crimped lyocell multifilament has a total fineness of 15,000 to 45,000 denier and has 20 to 50 crimps per inch.
The lyocell material of claim 1,
wherein the emulsion is included in a content of 0.1 wt% or more, based on 100 wt% of the total lyocell material for a smoking article filter.
The lyocell material of claim 1,
wherein the emulsion is included in a content of 20 wt% or less, based on 100 wt% of the total lyocell material for a smoking article filter.
A smoking article, including the lyocell material for a smoking article filter
according to claim 1.
A method of preparing a lyocell material for a smoking article filter, the method including:
treating a lyocell multifilament with an emulsion; and

imparting crimps to the lyocell multifilament,

wherein the treatment with an emulsion is performed such that an electrostatic value measured from the lyocell material is 0.01 kV to 1.4 kV.
The method of claim 13,
wherein the emulsion includes (a) an ester of a fatty acid having 16 or more carbons and an aliphatic monohydric alcohol, and (b) an ester of sorbitan and a fatty acid having 16 or more carbons.
The method of claim 13,
wherein the emulsion is included in a content of 0.1 wt% or more, based on 100 wt% of the total lyocell material for a smoking article filter.
The method of claim 13,
wherein the emulsion is included in a content of 20 wt% or less, based on 100 wt% of the total lyocell material for a smoking article filter.
The method of claim 13,
wherein the lyocell multifilament has a total fineness of 15,000 to 45,000 denier and has 20 to 50 crimps formed per inch.
A smoking article filter including a lyocell material,
wherein the lyocell material includes a crimped lyocell multifilament and an emulsion coated on the lyocell multifilament,

wherein an electrostatic value measured from the lyocell material is 0.01 kV to 1.4 kV.
A smoking article, including the smoking article filter according to claim 18.
A method of preparing a smoking article filter, the method including:
treating a lyocell multifilament with an emulsion; imparting crimps to the lyocell multifilament; and preparing a filter by using the crimped lyocell multifilament,

wherein the treatment with an emulsion is performed such that an electrostatic value measured from a lyocell material for the smoking article filter is 0.01 kV to 1.4 kV.