Lyocell material with whiteness adjusted through hydrogen peroxide treatment and method for producing the same

Abstract

The present invention relates to a lyocell material with adjusted whiteness through hydrogen peroxide treatment, which is suitable for cigarette filters and can replace cellulose acetate (CA) cigarette filters and mitigate environmental pollution caused by discarded cigarette butts, by allowing a certain amount of hydrogen peroxide to remain in the tow and improving the whiteness through the maturation effect of drying and packaging, and to a manufacturing method thereof.

Description

Technical Field

[0001] <Cross - reference to Related Applications> This application claims the benefit of priority based on Korean Patent Application No. 10 - 2021 - 0129847 filed on September 30, 2021, and Korean Patent Application No. 10 - 2022 - 0118768 filed on September 20, 2022, and all the contents disclosed in the documents of the Korean patent applications are included as part of this specification.

[0002] The present invention relates to a lyocell material whose whiteness is adjusted through hydrogen peroxide treatment and a method for manufacturing the same.

Background Art

[0003] A general tobacco filter contains cellulose acetate (CA) tow obtained by extracting cellulose from wood pulp and acetylating it.

[0004] The above - mentioned CA (cellulose acetate) adds a photocatalyst (TiO2) for realizing whiteness, but due to various problems of TiO2, it cannot be used. Currently, in a situation where no photocatalyst substance to replace TiO2 has been developed, it is known that no photocatalyst is added to CA for future tobacco filters.

[0005] Also, recently, for environmental protection and cost reduction, research has been underway to replace cellulose acetate tow with an environmentally friendly material. For example, unlike cellulose acetate, the development of tow using lyocell fibers obtained by fiberizing cellulose itself has been underway.

[0006] However, in the case of tow using lyocell fibers up to now, there is a problem that it is difficult to realize the whiteness (white index of 80 or more and yellow index of 8 or less) required by tobacco manufacturers.

Summary of the Invention

Problems to be Solved by the Invention

[0007] One embodiment of the present invention is capable of realizing whiteness equal to or higher than that of currently used photocatalytically treated CA material tows and is suitable for use as cigarette filters, and provides a lyocell material whose whiteness is adjusted through hydrogen peroxide treatment and a method for producing the same.

[0008] Another embodiment of the present invention provides a lyocell material whose whiteness is adjusted through hydrogen peroxide treatment and a method for producing the same, which can reduce environmental pollution factors caused by waste of the CA (cellulose acetate) cigarette butts.

Means for Solving the Problems

[0009] In this specification, according to one embodiment, (S1) spinning a lyocell spinning dope containing cellulose pulp and an aqueous solution of N-methylmorpholine-N-oxide (NMMO); (S2) coagulating the spun lyocell spinning dope to obtain lyocell multifilaments; (S3) washing the obtained lyocell multifilaments with water; (S4) treating the washed lyocell multifilaments with an oil agent and hydrogen peroxide; (S5) crimping the lyocell multifilaments treated with the above-mentioned oil agent and hydrogen peroxide to obtain a crimped tow; (S6) drying the crimped tow,

[0010] The step (S4) is simultaneously treating the washed lyocell multifilaments with an oil agent and hydrogen peroxide in a bath containing a mixed solution of an oil agent and hydrogen peroxide, the concentration of which is maintained uniformly, or Provided is a method for manufacturing a lyocell material, including the step of sequentially treating the washed lyocell multifilament with a tank containing hydrogen peroxide and a tank containing an oil agent single solution.

[0011] Also, in this specification, according to another embodiment, the lyocell multifilament spun from a lyocell spinning dope containing cellulose pulp and an aqueous solution of N-methylmorpholine-N-oxide (NMMO) contains a crimped tow that is bleached with an oil agent and hydrogen peroxide.

[0012] The crimped tow contains a lyocell crimped tow that contains hydrogen peroxide of 1,000 ppm or less and simultaneously satisfies a whiteness of 80 or more and a yellowness of 8 or less, providing a lyocell material.

[0013] Also, in this specification, a tobacco filter containing the lyocell material is provided.

[0014] Hereinafter, the lyocell material for a tobacco filter and its manufacturing method according to an embodiment of the invention will be described in detail.

[0015] Prior to that, unless explicitly mentioned in this specification, the technical terms are merely for referring to specific embodiments and are not intended to limit the present invention.

[0016] The singular forms used in this specification also include plural forms unless the context clearly indicates the contrary.

[0017] The meaning of "including" used in this specification does not exclude the presence or addition of other specific characteristics, regions, integers, steps, operations, elements, and / or components while specifying a specific characteristic, region, integer, step, operation, element, and / or component.

[0018] In this specification, the terms "at least one" or "one or more" should be understood to include all combinations that can be presented from one or more related items.

[0019] Hereinafter, the present invention will be described in detail.

[0020] <Method for manufacturing lyocell material> According to an embodiment of the invention, (S1) Spinning a lyocell spinning dope containing cellulose pulp and an aqueous solution of N-methylmorpholine-N-oxide (NMMO); (S2) Coagulating the spun lyocell spinning dope to obtain lyocell multifilament; (S3) Washing the obtained lyocell multifilament with water; (S4) Treating the washed lyocell multifilament with an oil agent and hydrogen peroxide; (S5) Crimping the lyocell multifilament treated with the above-mentioned oil agent and hydrogen peroxide to obtain a crimped tow; (S6) Drying the crimped tow, and the method for manufacturing a lyocell material includes:

[0021] In the step (S4), In a tank containing a mixed solution of an oil agent and hydrogen peroxide in which the concentration is maintained uniformly, treating the washed lyocell multifilament with the oil agent and hydrogen peroxide simultaneously, or A method for manufacturing a lyocell material can be provided, which includes treating the washed lyocell multifilament sequentially with a tank containing hydrogen peroxide and a tank containing an oil agent alone solution.

[0022] In the present invention, a lyocell fiber whose whiteness is adjusted through hydrogen peroxide treatment and a method for manufacturing the same are provided.

[0023] The hydrogen peroxide is a chemical used in the bleaching process of fiber fabrics, and is used in the process of removing pigments and colored impurities in the fabric by utilizing the oxidation action that utilizes active oxygen (generated radical oxygen).

[0024] Focusing on such points, in the present invention, in the manufacturing process of lyocell cigarette filter tow, a bleaching treatment step using hydrogen peroxide within a certain concentration range is added to provide a method capable of achieving a whiteness level equivalent to or higher than that of currently used (current) cellulose acetate (CA). That is, the present invention applies generally used hydrogen peroxide to the continuous process of manufacturing tow for lyocell cigarette filters while maintaining the concentration, and can improve the whiteness of the tow in a short time.

[0025] Specifically, the hydrogen peroxide can be used while maintaining a concentration of 2 to 6% by weight, or 3 to 6% by weight, with respect to the content of hydrogen peroxide in the solution for treating lyocell multifilaments.

[0026] At this time, even when using the hydrogen peroxide, adjusting its concentration within the range of 2 to 6% by weight, or 3 to 6% by weight, can leave the hydrogen peroxide content in the final tow at 1,000 ppm or less and can achieve an excellent effect on whiteness. More specifically, the improvement of whiteness can be optimized by maintaining the content of the hydrogen peroxide at 3 to 6% by weight, or 4 to 6% by weight.

[0027] If the concentration of the hydrogen peroxide is low, the bleaching reaction of the lyocell multifilaments becomes inactive, and it is difficult to achieve the required whiteness and yellowness. On the other hand, if the concentration of the hydrogen peroxide is high, the hydrogen peroxide content in the multifilaments increases, exceeding the management range of the hydrogen peroxide content in the final cigarette filter tow, and it is difficult to utilize as a cigarette filter material.

[0028] That is, if the concentration range of the hydrogen peroxide according to the present invention is not maintained, the desired whiteness and physical properties cannot be simultaneously achieved with excellent maintenance.

[0029] In addition, in order to achieve the whiteness of the rayon for the cigarette filter as intended in the present invention, during the manufacturing process, in the step of applying an oil agent to the filament yarn, hydrogen peroxide treatment may be carried out simultaneously, or alternatively, treatment may be carried out sequentially with hydrogen peroxide and an oil agent single solution. In such a case, the concentrations of the oil agent and hydrogen peroxide may be configured and added to the concentrations within the range according to this specification so as to be maintained uniformly. More specifically, when the above-described treatment with the oil agent and hydrogen peroxide is carried out simultaneously on the washed rayon multifilament, it is possible to more effectively achieve and adjust the whiteness and yellowness levels required in the industry.

[0030] Thereby, the present invention can produce cigarette filter tow applying biodegradable rayon, and can add hydrogen peroxide in the tow manufacturing process to achieve the whiteness required by cigarette manufacturers without adding a photocatalyst (TiO2). Therefore, in this specification, the currently used (in-use) CA (cellulose acetate) cigarette butt (filter) can be manufactured by an environmentally friendly (eco-friendly) method compared to the conventional method.

[0031] Hereinafter, the method for manufacturing a rayon material with whiteness adjusted through hydrogen peroxide treatment according to the present invention will be described in more detail for each step.

[0032] [(S1) Step] In the present invention, the (S1) step is a step of spinning a rayon spinning dope containing cellulose pulp and an aqueous solution of N-methylmorpholine-N-oxide (NMMO). At this time, the rayon spinning dope may contain 8 to 13% by weight of cellulose pulp and 87 to 92% by weight of an aqueous solution of N-methylmorpholine-N-oxide (NMMO), and the cellulose pulp may have an α-cellulose content of 85 to 97% by weight and a degree of polymerization (DPw) of 600 to 1,700.

[0033] If the content of the cellulose pulp is less than 8% by weight, it is difficult to embody fiber characteristics, and if it exceeds 13% by weight, it becomes difficult to dissolve in an aqueous solution state. Further, if the content of the aqueous solution of N-methylmorpholine-N-oxide (NMMO) is less than 87% by weight, the dissolution viscosity becomes excessively high, which is undesirable, and if it exceeds 92% by weight, the spinning viscosity becomes excessively low, and it becomes difficult to produce uniform fibers at the spinning stage.

[0034] In the aqueous solution of N-methylmorpholine-N-oxide (NMMO), the weight ratio of N-methylmorpholine-N-oxide (NMMO) to water can be 93:7 to 85:15. When the weight ratio of N-methylmorpholine-N-oxide (NMMO) to water exceeds 93:7, the dissolution temperature becomes high, and cellulose decomposition occurs during cellulose dissolution. When the weight ratio is less than 85:15, the dissolution performance of the solvent decreases, and cellulose dissolution may become difficult.

[0035] Using the aforementioned spinning dope, it is discharged from the spinning nozzles of a planar or donut-shaped spinneret. At this time, the spinneret serves to discharge the filamentous spinning dope through an air gap section into the coagulating liquid in the coagulation bath. The step of discharging the spinning dope from the spinneret can be carried out at 100 to 120°C.

[0036] [(S2) step] In the present invention, the (S2) step is a step of coagulating the lyocell spinning dope spun in the (S1) step to obtain lyocell multifilaments. The coagulation in the (S2) step may include a primary coagulation step by air quenching (Q / A: air quenching) in which cooling air is supplied to the spinning dope for coagulation, and a secondary coagulation step in which the primarily coagulated spinning dope is immersed in a coagulating liquid for coagulation.

[0037] In the step (S1), after the spinning dope is discharged through a planar or donut-shaped spinneret, it can be passed through the air gap section of the space between the aforementioned spinneret and the coagulation bath. In such an air gap section, when the spinneret is in a planar form, cooling air is supplied from one side of the spinneret to the opposite side, and when the spinneret is in a donut form, cooling air is supplied from the air-cooled part located inside, from the inside to the outside of the spinneret, and a suction function can also be added to the opposite side or the outside. Primary coagulation can be achieved by air quenching in which such cooling air is supplied to the spinning dope.

[0038] At this time, the factors affecting the physical properties of the lyocell multifilament obtained in the step (S2) are the temperature and wind speed of the cooling air in the air gap section, and the coagulation in the step (S2) can be carried out by supplying cooling air with a temperature of 4 to 15 °C and an air volume of 50 to 250 L / m 3 to the spinning dope.

[0039] During the primary coagulation, if the temperature of the cooling air is less than 4 °C, the temperature of the spinneret surface becomes low, the cross-section of the lyocell multifilament becomes non-uniform, and the spinning processability is not good. If it exceeds 15 °C, the primary coagulation by the cooling air is not sufficient, and the spinning processability becomes not good.

[0040] Also, during the primary coagulation, if the air volume of the cooling air is less than 50 L / m 3 , the primary coagulation by the cooling air is not sufficient, so the spinning processability becomes not good and yarn breakage occurs. If it exceeds 250 L / m 3 , as the spinning dope discharged from the spinneret sways due to the air, the spinning processability becomes not good.

[0041] After primary coagulation by air quenching, the spinning dope is supplied to a coagulation bath containing a coagulating liquid, and secondary coagulation can proceed. On the other hand, for proper progress of secondary coagulation, the temperature of the coagulating liquid can be 30°C or lower. This is because the temperature of secondary coagulation is not higher than necessary so that the coagulation rate can be properly maintained. Here, since the coagulating liquid can be manufactured and used with a normal composition in the technical field to which the present invention belongs, it is not particularly limited.

[0042] [(S3) step] In the present invention, the (S3) step is a step of washing the lyocell multifilament obtained in the (S2) step. More specifically, it is a step of introducing the lyocell multifilament obtained in the (S2) step into a drawing roller and then into a water washing tank for water washing.

[0043] In the step of washing the filament, after washing, considering the ease of solvent recovery and reuse, a washing liquid with a temperature of 0 to 100°C can be used. As the washing liquid, water can be used, and if necessary, other additive components can also be further included.

[0044] [(S4) step] In the present invention, the (S4) step is a step of treating the washed lyocell multifilament with an oil agent and hydrogen peroxide.

[0045] Such an (S4) step can be a step of sequentially using i) a mixed solution of an oil agent and hydrogen peroxide, or ii) a single solution of an oil agent and hydrogen peroxide to treat the lyocell multifilament washed in the (S3) step. By adjusting the whiteness of the lyocell fiber treated through the process, a desired level of whiteness can be achieved.

[0046] That is, the step (S4) is characterized by treating the lyocell multifilament washed in the step (S3) simultaneously with an oil agent and hydrogen peroxide in a tank containing a mixed solution of the oil agent and hydrogen peroxide in which the concentration is maintained uniformly.

[0047] Optionally, the step (S4) may include a step of sequentially treating the washed lyocell multifilament with a tank containing hydrogen peroxide and a tank containing an oil agent single solution. In such a method, the tanks containing the hydrogen peroxide and the oil agent single solution are also made to have a uniform concentration.

[0048] For the above-mentioned treatment with the oil agent and hydrogen peroxide, a method of immersing and discharging the filament tow in a tank constituted by the oil agent and hydrogen peroxide is used. In particular, hydrogen peroxide can be treated by a method of adding it at a constant concentration simultaneously when it is constituted by the oil agent.

[0049] Specifically, the method is such that the oil agent and hydrogen peroxide penetrate uniformly into the washed lyocell multifilament, but it is important to keep the concentrations of both the oil agent and hydrogen peroxide uniformly constant.

[0050] Therefore, in this specification, a method of adding two components to be constituted at a certain concentration may be used so that the concentrations of the oil agent and hydrogen peroxide are continuously maintained uniformly in the tank.

[0051] Accordingly, according to one embodiment of the invention, the step of treating with the above-described oil agent and hydrogen peroxide (S4) is a method in which the filament washed with water in the above step (S3) is immersed in a tank composed of a mixed solution of an oil agent and hydrogen peroxide, in which the concentration is maintained uniformly, and then discharged, and at the same time, it may include a step of being treated with hydrogen peroxide. In such a case, a tank composed of a mixed solution of an oil agent and hydrogen peroxide is provided, and it may be connected and installed to the water washing tank. Further, a device for adding hydrogen peroxide and an oil agent may be connected to the tank containing the two components so that the concentration is maintained uniformly.

[0052] Also, according to another embodiment of the invention, the step of treating with the above-described oil agent and hydrogen peroxide (S4) is a method in which the filament washed with water in the above step (S3) is sequentially immersed in a tank containing hydrogen peroxide alone in which the concentration is maintained uniformly and a tank composed of an oil agent alone solution, and then discharged, and it may include a step of being treated with an oil agent and hydrogen peroxide. In such a case, a tank containing hydrogen peroxide and a tank composed of an oil agent alone solution are connected and provided, and they may be connected and provided to the water washing tank. Further, a device for adding hydrogen peroxide and an oil agent may be connected to each of the above tanks so that the concentration is maintained uniformly.

[0053] Desirably, in the step (S4), the lyocell multifilament washed with water in the step (S3) is simultaneously treated using a mixed solution of an oil agent and hydrogen peroxide in which the concentration is maintained, so that excellent whiteness and yellowness can be more effectively realized.

[0054] At this time, the hydrogen peroxide can be used while maintaining the hydrogen peroxide content in the solution for treating the lyocell multifilament at a concentration of 2 to 6% by weight. Further, the hydrogen peroxide can be made into an aqueous solution state and continuously added to the tank so as to be maintained at the above concentration. Further, the tank may be provided with means for maintaining the concentrations of the oil agent and hydrogen peroxide. For example, a concentration measuring device for the oil agent and hydrogen peroxide may be provided, and a discharging means for circulating the oil agent and hydrogen peroxide may be provided so as to maintain the water level and a certain standard for the mixed solution containing the oil agent and hydrogen peroxide.

[0055] If the concentration of the hydrogen peroxide is 2% by weight or less, the desired whiteness cannot be achieved and it cannot penetrate uniformly inside the multifilament, so there is a problem that bleaching does not react completely after the post-treatment of crimping. If it is 6% by weight or more, even if the hydrogen peroxide content in the tow increases, the whiteness is not improved compared to the usage amount, and an excess remains even after the post-treatment of crimping of the multifilament, resulting in a problem that the physical properties are embrittled.

[0056] The oil agent can be used while maintaining the oil agent content in the solution for treating the lyocell multifilament at a concentration of 2 to 8% by weight, or a concentration of 3 to 7% by weight. Maintaining the oil agent content within the above range can serve to reduce the friction generated when the lyocell multifilament in the crimping stage contacts the apparatus, and to enable good formation of the crimp between the fibers.

[0057] Thus, if the concentrations of the hydrogen peroxide and the oil agent are not maintained, it is difficult to perform uniform bleaching treatment of the lyocell multifilament, the crimping process is not smooth, or it causes deterioration of the physical properties of the lyocell material in the post-treatment, so the effects of improving whiteness and physical properties cannot be obtained. Therefore, when proceeding to the step (S4), it is important to maintain the concentrations of the hydrogen peroxide and the oil agent as described above.

[0058] By performing the above-mentioned step (S4), the whiteness of the tow for the riocell cigarette filter can be improved to a level higher than before, and the deterioration of physical properties after the post-treatment step of forming the crimp can be prevented.

[0059] At this time, the oiling treatment is performed in a state where the multifilament is completely immersed in the oiling agent, and the amount of the oiling agent penetrating into the filaments is kept constant by the squeeze rollers attached to the entry roll and the discharge roll of the oiling agent treatment apparatus.

[0060] Also, the hydrogen peroxide treatment can be performed in a state where the riocell multifilament is completely immersed in the tank together with the oiling agent. Further, after performing the step (S4), the step (S5) (the crimping step) can be immediately performed without drying the oiling agent and hydrogen peroxide.

[0061] In addition, the oiling agent used for the filament coating can be one developed specifically for riocell, which is different from the oiling agents used for general fibers, and it does not react with hydrogen peroxide and is uniformly made up.

[0062] According to a preferred embodiment, the oiling agent can impart lubricating functions that can uniformly impart physical properties to the tobacco filter tow, impart an appropriate level of smoothness and cohesion, optimize the filter manufacturing processability, and minimize the phenomenon that the shape of the filter is deformed and the hardness of the filter is reduced by the saliva of the smoker during smoking. To this end, the oiling agent imparts hydrophobicity that can delay the penetration of saliva into the filter and can slow down the rate at which the filter hardness decreases. Also, even if a certain amount of the oiling agent remains in the tobacco filter, it can be composed of components harmless to the human body of the smoker.

[0063] However, the oil agent serves to reduce the friction generated when the filament comes into contact during the drying roller, guiding, and crimping stages, so that the crimp between the fibers can be formed well. If it is generally used in the production of lyocell filaments, there is no special restriction on its type.

[0064] For a desirable example, the oil agent may also contain one or more selected from the group consisting of a lubricating component, a cohesion component, a smoothness component, and a hydrophobic component.

[0065] [(S5) stage] (The (S5) stage is a stage of crimping the lyocell multifilament treated with the oil agent and hydrogen peroxide to obtain a crimped tow.

[0066] Specifically, the method is a stage of applying steam and pressure to the lyocell multifilament treated with the oil agent and hydrogen peroxide for crimping. Through the (S5) stage, a crimped tow can be obtained.

[0067] The term "crimping" described throughout this specification mainly means imparting wrinkles to the filament in order to impart a bulk feel to the fiber. The crimping process in the present invention can be carried out through a stuffer box equipped with press rollers. The press roller can be a nip roller.

[0068] At this time, a steam box for steam treatment of the filament tow is configured at the front end of the stuffer box, and the steam pressure supplied to the steam box is 0.1 to 3 kgf / cm 2 and the pressure of the press roller is 1.5 to 4 kgf / cm 2and is desirably controlled so as to satisfy the condition that the upper plate pressure is 0.1 to 3 kgf / cm 2 If the steam pressure is less than 0.1 kgf / cm 2 , the modulus of the filament does not become low enough for the process, and the crimp is not formed smoothly. If it exceeds 3 kgf / cm 2 and an excessive amount of steam is supplied, the modulus of the filament is minimized, but due to the excessive moisture content, the required number of crimps cannot be uniformly imparted.

[0069] Also, when the pressure applied through the press roller is less than 1.5 kgf / cm 2 , the thickness of the filament to be fed cannot be uniformly imparted, and the desired number of crimps is not uniformly formed. If it exceeds 4 kgf / cm 2 , the pressing force is very strong, and the content of moisture or sizing present in the tow may suddenly decrease, and the filament may not be able to pass through the stuffer box smoothly. At this time, in addition, the interval between the press rollers is desirably maintained at 0.01 to 3.0 mm. If the interval between the press rollers is less than 0.01 mm, the pressure of the filament by the rollers becomes high, and crimp formation is impossible, or after formation, damage occurs due to filament surface friction. If it exceeds 3.0 mm, a filament slip phenomenon occurs between the press rollers, and uniform crimp formation may become difficult.

[0070] Also, after passing through the press roller, in order to impart a uniform crimp, if the pressure of the upper plate that moves up and down is less than 0.1 kgf / cm 2 , the upper plate is not fixed due to the pressure inside the stuffer box, and as the tow stays in the stuffer box for a long time, can the continuity of the process be maintained, or can an appropriate residence time be imparted, and the desired number of crimps of the tow cannot be adjusted. If it is 3.0 kgf / cm 2If it is more than that, the cobs will not be smoothly discharged into the buffer box, and the crimp form will become irregular.

[0071] Under such conditions, the cobs crimped can ensure and maintain crimps of 20 or more per inch, 20 to 40 per inch, or 30 to 40 per inch. Thereby, the lyocell-crimped cobs of the present invention are biodegradable and removed within a short time, so that they are not only environmentally friendly, but also satisfy the required physical properties such as draw resistance, filter strength, and filter removal ability when manufactured into a tobacco filter, and can maximize the effect.

[0072] [(S6) step] (The (S6) step is a step of drying the crimped cobs obtained in the (S5) step at a constant temperature.

[0073] Specifically, the sizing agent and hydrogen peroxide uniformly immersed in the filament cobs in the sizing agent treatment tank are picked up to a level that can impart a uniform number of crimps in the crimping process.

[0074] Thereafter, by drying the crimped tow through a continuous drying device, the final lyocell-crimped tow containing a uniform amount of hydrogen peroxide can be manufactured.

[0075] The step of drying the crimped tow can be carried out using a continuous drying device at 105 to 135 °C for 15 to 45 minutes, or at 110 to 130 °C for 20 to 40 minutes. More preferably, the step of drying the crimped tow is carried out at 110 to 130 °C for 20 to 40 minutes, which can contribute to further smoothly advancing the bleaching reaction and providing a product with excellent whiteness.

[0076] If the drying temperature is 105°C or lower, there is a problem that the bleaching reaction does not occur well, the tow is not perfectly dried, and it cannot be adjusted to the required moisture content. If it is 135°C or higher, there is a problem that the whiteness decreases due to the yellowing phenomenon. Also, if the drying time is 15 minutes or less, the bleaching reaction does not occur well, and irregular, undried parts may occur. If it is 45 minutes or more, there is a problem that excessive drying time causes damage to the tow surface and the whiteness decreases due to the yellowing phenomenon.

[0077] That is, for the multifilament treated with an oil agent and hydrogen peroxide, in order to have a smooth bleaching reaction of the hydrogen peroxide contained in the tow, it may be desirable to set the conditions of the continuous drying device within the above range.

[0078] Also, the finally produced tow after the drying contains hydrogen peroxide at 1,000 ppm or less, and the packaged tow may have an additional bleaching effect due to the aging effect. Therefore, according to the present invention, a tobacco filter with better whiteness can be provided by aging due to tow packaging.

[0079] <Lyocell material> According to another embodiment of the present invention, a lyocell material is provided that includes a crimped tow in which a lyocell multifilament spun from a lyocell spinning dope containing cellulose pulp and an aqueous solution of N-methylmorpholine-N-oxide (NMMO) is bleached with an oil agent and hydrogen peroxide. The crimped tow contains hydrogen peroxide at 1,000 ppm or less and satisfies both a whiteness of 80 or more and a yellowness of 8 or less.

[0080] By the above-described method, the present invention can improve the whiteness by allowing a certain amount of hydrogen peroxide to remain in the tow by using hydrogen peroxide in a certain concentration range together in the oil agent treatment step of tow production. In particular, the whiteness can be further improved by the aging effect due to drying and packaging.

[0081] By the way, even if the hydrogen peroxide content in the cryptophyte satisfies 1,000 ppm or less, if the content is excessively low, the whiteness level required for the tobacco filter cannot be exhibited. Therefore, even if the hydrogen peroxide content in the cryptophyte satisfies 1,000 ppm or less, it should be contained at a certain content or more. Specifically, the lower limit should be 110 ppm or more.

[0082] Thereby, the cryptophyte can be a lyocell cryptophyte containing 110 ppm or more and 1,000 ppm or less of hydrogen peroxide, and simultaneously satisfying a whiteness of 80 to 90 and a yellowness of 1 to 4.5. More specifically, it can be a lyocell cryptophyte having excellent whiteness, containing 400 ppm or more and 980 ppm or less of hydrogen peroxide, and simultaneously satisfying a whiteness of 80 to 90 and a yellowness of 1 to 4.

[0083] In addition, the lyocell material according to the present invention can embody the whiteness (white index 80 or more, yellow index 8 or less) required by tobacco manufacturers.

[0084] Furthermore, the present invention can replace the CA (cellulose acetate) tobacco filter and alleviate the environmental pollution problem caused by waste cigarette butts.

[0085] [[ID=ID=18]]At this time, the concentration of the hydrogen peroxide used for the bleaching treatment of the lyocell cryptophyte can be 2 to 6% by weight.

[0086] The lyocell spinning dope can contain 8 to 13% by weight of cellulose pulp and 87 to 92% by weight of an aqueous solution of N-methylmorpholine-N-oxide (NMMO).

[0087] The cellulose pulp can have an α-cellulose content of 85 to 99% by weight and a degree of polymerization (DPw) of 600 to 1,700.

[0088] In addition, according to another embodiment of the present invention, a tobacco filter containing the lyocell material with the adjusted whiteness may be provided.

[0089] The configuration of the tobacco filter is not limited except that the lyocell tow with improved whiteness is used.

[0090] For example, the tobacco filter may include a cylindrical or tubular lyocell tow containing a plurality of lyocell fibers, a plasticizer, a hardening agent, etc.

[0091] The plurality of lyocell fibers can be connected to each other by a hardening agent and exhibit a structure in which the fiber surfaces are joined to each other in contact with the hardening agent.

[0092] Well-known substances are used as the hardening agent to improve the hardness of the filter. For example, the hardening agent may include a cellulose derivative, a vinyl-based derivative, a vinyl-based emulsion resin, a natural polymer resin containing sodium alginate, and a polymer resin such as starch or a starch derivative.

Advantages of the Invention

[0093] According to the present invention, in the process of manufacturing tow for a lyocell tobacco filter, a chemical agent (hydrogen peroxide) for improving whiteness is added, and the hydrogen peroxide content is left at 1,000 ppm or less in the tow, so that tow with excellent whiteness can be provided. In addition, in the present invention, through the aging effect of a drying process in which a bleaching reaction proceeds under certain conditions and a packaging process of the dried substance, the whiteness can be further improved.

[0094] Therefore, the present invention can add a bleaching process to the existing process of manufacturing tow for a tobacco filter and realize the whiteness (white index of 80 or more and yellow index of 8 or less) required by tobacco manufacturers.

[0095] In addition, the present invention can provide lyocell in an environmentally friendly method, thus replacing conventional CA (cellulose acetate) cigarette filters and reducing environmental pollution factors caused by discarded cigarette butts.

Mode for Carrying Out the Invention

[0096] Hereinafter, the present invention will be described in more detail through examples. However, the following examples are only for helping the understanding of the present invention, and the scope of rights of the present invention is not limited thereby.

[0097] <Example 1> Cellulose pulp with a polymerization degree (DPw) of 820 and an α-cellulose content of 93.9% was mixed with an N-methylmorpholine-N-oxide (NMMO) / H2O mixed solvent (weight ratio 90 / 10) with a propyl gallate content of 0.01% by weight to produce a spinning dope for manufacturing tobacco for cigarette filters with a concentration of 12% by weight. First, the spinning dope was maintained at a spinning temperature of 110°C in a spinning nozzle, and the discharge rate and spinning speed were adjusted to spin the dope so that the filament fineness was 2.4 denier.

[0098] The filamentous spinning dope discharged from the spinning nozzle was supplied to the coagulating liquid in the coagulation bath through an air gap section. At this time, in the air gap section, the cooling air primary coagulated the spinning dope at a temperature of 8°C and an air volume of 100 L / m 3 The coagulating liquid used was at a temperature of 25°C and had a concentration of 75% by weight of water and 25% by weight of N-methylmorpholine-N-oxide (NMMO). At this time, the coagulating liquid concentration was continuously monitored using a sensor and a refractometer.

[0099] The filament coagulated through the draw roller was washed with the sprayed washing liquid in a washing device to remove the N-methylmorpholine-N-oxide (NMMO) remaining in the filament.

[0100] Thereafter, the washed filaments were immersed in a tank containing an oil agent and hydrogen peroxide, which was constituted by a mixed solution of 2% by weight of the oil agent and 5% by weight of the hydrogen peroxide concentration. That is, the oil agent and hydrogen peroxide were added to the filaments in such a way that the oil agent content was maintained at 2% by weight and the hydrogen peroxide content was maintained at 5% by weight so that the oil agent and hydrogen peroxide could penetrate uniformly into the filaments, and the concentration in the tank was continuously maintained uniformly at a certain concentration.

[0101] The filaments immersed in the tank were treated with the oil agent and simultaneously treated with hydrogen peroxide by discharging them after the immersion process.

[0102] Specifically, the filament tow immersed in the treatment tank was treated with a nip roller provided in the staff box at the front end of the crimper device provided at the discharge part of the tank at a pressure of 2 kgf / cm 2 pressure, and after discharging the multifilaments treated with the oil agent and hydrogen peroxide from the tank, they were put into a crimper device (crimp M / C) for crimping to produce a lyocell crimped tow. The produced tow was passed through a continuous drying device set at 120°C to obtain a dried tow product (drying treatment time: 25 minutes).

[0103] <Example 2> A lyocell tow for a tobacco filter was produced in the same manner as in Example 1, except that the hydrogen peroxide concentration was changed to 3% by weight.

[0104] <Example 3> A lyocell tow for a tobacco filter was produced in the same manner as in Example 1, except that the hydrogen peroxide concentration was changed to 2% by weight.

[0105] <Example 4> A lyocell tow for a tobacco filter was produced in the same manner as in Example 1, except that the hydrogen peroxide concentration was changed to 6% by weight.

[0106] <Example 5> A tobacco filter tow made of lyocell was produced in the same manner as in Example 1, except that when treating the washed lyocell multifilament with an oil agent and hydrogen peroxide, the washed lyocell multifilament was successively immersed in a tank composed of 5% by weight of hydrogen peroxide and a tank composed of 2% by weight of the oil agent.

[0107] Also, in order for the oil agent and hydrogen peroxide to uniformly penetrate into the filaments, a method was used in which the oil agent and hydrogen peroxide were added at a constant concentration so that their concentrations were continuously and uniformly maintained in their respective tanks. In such a manner, the oil agent content was maintained at 2% by weight and the hydrogen peroxide content was maintained at 5% by weight.

[0108] <Comparative Example 1> A tobacco filter tow made of lyocell was produced in the same manner as in Example 1, except that only 2% by weight of the oil agent was used without adding hydrogen peroxide.

[0109] <Comparative Example 2> A tobacco filter tow made of lyocell was produced in the same manner as in Example 1, except that the hydrogen peroxide concentration was changed to 1% by weight.

[0110] <Comparative Example 3> A tobacco filter tow made of lyocell was produced in the same manner as in Example 1, except that the hydrogen peroxide concentration was changed to 7% by weight.

[0111] <Comparative Example 4> A tobacco filter tow made of lyocell was produced in the same manner as in Example 1, except that the hydrogen peroxide concentration was changed to 10% by weight.

[0112] <Comparative Example 5> A lyocell tow for cigarette filters was produced in the same manner as in Example 1, except that the drying treatment conditions were changed to 100 °C for 50 minutes in a continuous drying apparatus.

[0113] <Comparative Example 6> A lyocell tow for cigarette filters was produced in the same manner as in Example 1, except that the drying treatment conditions were changed to 100 °C for 10 minutes in a continuous drying apparatus.

[0114] <Comparative Example 7> A lyocell tow for cigarette filters was produced in the same manner as in Example 1, except that the drying treatment conditions were changed to 140 °C for 10 minutes in a continuous drying apparatus.

[0115] <Comparative Example 8> A lyocell tow for cigarette filters was produced in the same manner as in Example 1, except that the drying treatment conditions were changed to 140 °C for 50 minutes in a continuous drying apparatus.

[0116] [Experimental Example] For the lyocell tows of the examples and comparative examples, the hydrogen peroxide content in the tow and the whiteness of the tow were measured by the following method, and the results are shown in Table 1.

[0117] <Physical Property Measurement Method> (1) Measurement of hydrogen peroxide content in the tow Applying the principle of redox titration, potassium permanganate was used as a standard solution (0.1 N), and volumetric analysis was performed.

[0118] The tows produced through the above examples and comparative examples were left standing under standard constant temperature and humidity conditions for 24 hours. Then, the tows were immersed in ultrapure water at a weight ratio of 10% by weight and subjected to ultrasonic treatment for 30 minutes. After the ultrasonic treatment, 10 ml of ultrapure water was taken, and 10 ml of distilled water and 2 ml of concentrated sulfuric acid were added. The prepared titration sample was titrated using a Karl Fischer experimental practical titrator with a standard solution to confirm the end point, and the hydrogen peroxide content in the tow was calculated by the following formula 1.

[0119] [Formula 1] H2O2(%) in corn = 0.0017 × V × F × D / S × 100

[0120] In Formula 1, 0.0017 is the mass (g) of hydrogen peroxide equivalent to 1 ml of 0.1N potassium permanganate solution, V is the titration volume (ml) of 0.1N potassium permanganate solution, F is the normality coefficient (factor) of 0.1N potassium permanganate solution, D is the dilution ratio (= 1) of the hydrogen peroxide-containing solution extracted from corn, and S is the sample weight (g).

[0121] At this time, it is related to the above D and is diluted when the concentration is high. However, in this specification, since the extract is used as it is, it is 1.

[0122] (2) Measurement of corn whiteness Using a CCM device (X-Rite ColorEye 7000A Spectrophotometer), the whiteness was measured.

[0123] For the measurement samples, three corns (ears) produced through the above Examples and Comparative Examples were prepared, and the middle part was broken in the same situation as the measurement of tensile strength. For the whiteness measurement, the experiment was repeated three times, and the broken parts were bundled so as to overlap. Then, the bundled samples were attached to the CCM device, and the whiteness index and yellowness index were measured, and the results were derived.

[0124]

Table 1

[0125] As shown in the physical property measurement results in Table 1 above, it was confirmed that the whiteness results of Examples 1 to 5 could achieve the level of whiteness required for tobacco filters and could adjust the whiteness in various ways compared to the comparative examples (whiteness (W.I: 80 or more, Y.I: 8 or less)). Specifically, Examples 1 to 5 could provide lyocell crimp tow with excellent whiteness, containing 300 ppm or more and 980 ppm or less of hydrogen peroxide, and simultaneously satisfying a whiteness of 80 to 90 and a yellowness of 1 to 5.

[0126] Particularly, in the case of Examples 1 and 4 where the hydrogen peroxide concentration was maintained at 5 to 6% by weight, the lyocell crimp tow could provide a tobacco filter with excellent whiteness, with a W.I value of 81.4 to 82.1 and satisfying a Y.I of 3.3 to 3.4.

[0127] Also, in the case of Example 5 where an oil agent was treated after the pretreatment of hydrogen peroxide, the W.I value of the lyocell crimp tow was 80.0 and the Y.I value was 4.4, satisfying the desired whiteness result. Here, Example 5 was measured as having a slightly lower result value compared to the case of the tow where hydrogen peroxide and the oil agent were treated simultaneously. It can be inferred that the hydrogen peroxide contained in the tow was instantaneously removed by the oil agent during the oil agent treatment process after the pretreatment of hydrogen peroxide. However, Example 5 could simultaneously satisfy the ranges of whiteness and yellowness required in the industry compared to the comparative examples, even though the hydrogen peroxide content in the tow was 1,000 ppm or less, similar to Examples 1 to 4. Therefore, the tow of the examples according to this specification can be usefully used as a more environmentally friendly (affine) material for tobacco filters than existing ones.

[0128] On the other hand, in the case of Comparative Example 1, it was a tow not treated with hydrogen peroxide, and it was confirmed that the whiteness result was low at a level that could be clearly distinguished by the naked eye.

[0129] In addition, in Comparative Examples 2 to 4, even if the treatment with hydrogen peroxide is a factor affecting the manifestation of the whiteness of the corncob, the treatment content of hydrogen peroxide is outside the scope of the present invention, and due to the residual concentration, it was confirmed that an inflection phenomenon occurred in which the whiteness increased or decreased. In particular, in the case of Comparative Example 2, the content of hydrogen peroxide in the corncob was 1,000 ppm or less, but the content was very small and the whiteness could not satisfy the level required for tobacco filters. In addition, in Comparative Examples 3 and 4, due to the increase in the amount of hydrogen peroxide treatment, the content in the corncob was 1,000 ppm or more, but the whiteness decreased and the level required in the industry could not be satisfied, showing an uneconomical effect compared to the amount of hydrogen peroxide used.

[0130] In addition, in the case of Comparative Examples 5 to 8, even when the corncob was treated with hydrogen peroxide, during the drying process, the conditions were outside the scope of the present invention, the bleaching reaction of hydrogen peroxide did not occur correctly, and the desired whiteness could not be achieved.

[0131] Therefore, as in the present invention, when treating with hydrogen peroxide in a certain concentration range during the production of tobacco filter corncobs, excellent whiteness required by tobacco manufacturers can be achieved. At the same time, in the present invention, even when treated with hydrogen peroxide, the W.I value and Y.I value can be optimized by adjusting the temperature conditions during the bleaching reaction.

[0132] In addition, according to the present invention, existing photocatalyst-treated CA tobacco filters can be replaced, and environmental pollution caused by discarded tobacco sucking grains can be reduced more than before.

Claims

1. (S1) spinning a lyocell spinning dope containing cellulose pulp and an aqueous solution of N-methylmorpholine-N-oxide (NMMO); (S2) coagulating the spun lyocell spinning dope to obtain lyocell multifilaments; (S3) washing the obtained lyocell multifilaments with water; (S4) treating the washed lyocell multifilaments with an oil agent and hydrogen peroxide; (S5) crimping the lyocell multifilaments treated with the above oil agent and hydrogen peroxide to obtain a crimped tow; (S6) drying the crimped tow, comprising: The step (S4) is: treating the washed lyocell multifilaments simultaneously with an oil agent and hydrogen peroxide in a tank containing a mixed solution of an oil agent and hydrogen peroxide in which the concentration is maintained uniformly, or treating the washed lyocell multifilaments sequentially with a tank containing hydrogen peroxide and a tank containing an oil agent alone solution; The hydrogen peroxide in the step (S4) is used while maintaining a concentration of 2 to 6% by weight with respect to the content of hydrogen peroxide in the solution for treating the lyocell multifilaments; The step of drying the crimped tow in the step (S6) is performed using a continuous drying device at 105 to 135 ° C for 15 to 45 minutes. A method for producing a lyocell material.

2. The oil agent in the step (S4) is used while maintaining a concentration of 2 to 8% by weight with respect to the content of the oil agent in the solution for treating the lyocell multifilaments. The method for producing a lyocell material according to claim 1.

3. The oil agent in the step (S4) contains one or more selected from the group consisting of a lubricating component, a cohesion component, a smoothness component, and a hydrophobic component. The method for producing a lyocell material according to claim 1.

4. The lyocell spinning dope in the step (S1) contains 8 to 13% by weight of cellulose pulp and 87 to 92% by weight of an aqueous solution of N-methylmorpholine-N-oxide (NMMO). The method for producing a lyocell material according to claim 1.

5. The cellulose pulp has an α-cellulose content of 85 to 99% by weight and a degree of polymerization (DPw) of 600 to 1,700. The method for producing a lyocell material according to claim 1.

6. The manufacturing method of the lyocell material according to Claim 1, wherein the cryptophyte obtained in the step (S6) is a lyocell cryptophyte containing hydrogen peroxide of 1,000 ppm or less.

7. A lyocell material comprising a lyocell cryptophyte containing hydrogen peroxide of 1,000 ppm or less and simultaneously satisfying a whiteness of 80 or more and a yellowness of 8 or less.

8.

9. The lyocell material according to Claim 7, wherein the cryptophyte is a lyocell cryptophyte containing hydrogen peroxide of 110 ppm or more and 1,000 ppm or less and simultaneously satisfying a whiteness of 80 to 90 and a yellowness of 1 to 4.

10.

11. A tobacco filter comprising the lyocell material according to Claim 7 or 8.

Images