JP2010018895A - Wet spinning method for antimicrobial acrylic fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an antimicrobial acrylic fiber that retains antimicrobial activity for a long period of time, is mixed with another fiber material to give a mixed spun yarn having soft and excellent feeling. <P>SOLUTION: In the method for producing an antimicrobial acrylic fiber having a single fiber fineness of not more than 2.2 dtex, a crystalline fine particle supporting silver having a median diameter in a master batch of not less than 1 μm and a 90% particle diameter of not more than 5 μm is added as an antimicrobial agent in the spinning process and the ratio of the discharge linear velocity of a polymer from nozzles to the take-off speed of coagulated yarn is 0.7-1.2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is an antibacterial acrylic fiber that is used as a raw cotton for fine yarns, especially when mixed with other materials such as cotton and rayon, without sacrificing the texture and having an antibacterial effect for a long period of time. The present invention relates to a method for producing conductive acrylic fiber. Non

  As a method for imparting antibacterial properties to the fiber, an antibacterial agent is included in the spinning solution, and after spinning, heat treatment is performed and the resin is fixed to the resin. Although it is roughly classified into a method for fixing an antibacterial agent by reacting with a certain functional group, various methods have been proposed in order to meet such a demand due to the increasing demand for a comfortable living environment.

Patent Document 1 discloses an anionic dye-dyeable acrylonitrile fiber into which an acidic group of SCN ⁻ , P ₂ O ₇ ⁴⁻ , and C ₂ O ₄ ²⁻ is introduced with an aqueous solution of silver, copper, and zinc metal compounds. An antibacterial acrylonitrile fiber in which a water-insoluble metal compound is formed on the fiber surface by heat treatment is described. However, although this fiber is excellent in dyeability, it has been difficult to obtain antibacterial properties sufficient to obtain sufficient antibacterial performance when used in combination with acrylic fibers or other fibers.

  In the production of acrylic fibers, a nozzle with a very small diameter is required when spinning fine raw cotton, which is difficult to manufacture. Patent Document 2 proposes a fiber in which silver-supported zeolite is added to an acrylic fiber, but has not yet been produced into a fine-fine acrylic fiber considering the texture when used in a mixture of other materials.

On the other hand, Patent Documents 3 and 4 describe fibers containing antibacterial zeolite particles retaining metal ions having antibacterial action, but the polymer deteriorates in the melting process, and the fibers are colored yellow. There was a problem.
Patent Document 5 describes an antibacterial acrylonitrile fiber obtained by adding a fine metal compound exhibiting an antibacterial property to a cationic dye dyeable acrylonitrile fiber. However, according to the method for producing an antibacterial acrylonitrile fiber described in Patent Document 5, it is possible to obtain an antibacterial fiber having a fineness, but despite the complicated treatments of the first and second treatments. However, when the fiber was used as a cotton blend material, it was difficult to maintain antibacterial performance by post-processing such as an exposure process.

JP-A-8-27621 JP-A-2-160914 JP-A-63-175117 Japanese Patent Laid-Open No. 3-205436 JP-A-7-243169

  An object of the present invention is to provide an antibacterial acrylic fiber that retains antibacterial activity over a long period of time and can be blended with not only acrylic fibers but also other materials such as cotton to obtain a soft and soft blended yarn. The purpose is to develop a method for industrially stable production.

The present inventor has made extensive studies to solve the above-mentioned problems. As a result, by adjusting the polymer solution discharge linear velocity from the nozzle hole and the solidified yarn take-up speed, the fine fiber acrylic fiber having good antibacterial properties is maintained. Succeeded in getting.
That is, the present invention carries silver having a median diameter in a masterbatch of 1 μm or more and a 90% particle diameter of 5 μm or less in a method for producing an antibacterial acrylic fiber having a single fiber fineness of 2.2 dtex or less. Antibacterial by a wet spinning method in which crystalline fine particles are added as an antibacterial agent in the spinning process, and the ratio of the polymer solution discharge linear velocity from the nozzle hole to the coagulated yarn take-off rate (hereinafter JSR) is 0.7 to 1.2. A method for producing a reactive acrylic fiber is provided.

  According to the present invention, when mixed with other materials such as cotton and rayon, it is possible to obtain a fine fineness acrylic fiber imparted with good antibacterial properties without impairing the texture, and the antibacterial acrylic fiber By using it, a fine count acrylic or acrylic blended yarn can be provided that can be suitably used for clothing, particularly underwear.

The present invention will be described in detail below.
As the antibacterial agent used in the present invention, crystalline fine particles carrying silver are preferably used. The crystalline fine particles may be any particles that can exhibit antibacterial performance while supporting silver and releasing it as ions in water, and examples thereof include zeolite and zirconium phosphate. In particular, zeolite can be preferably used.

The median diameter of the crystalline fine particles supporting silver must be 1 μm or more. The median diameter refers to a particle diameter calculated from a particle size distribution measurement result in a master batch for addition to a spinning dope for wet spinning. When the median diameter is 1 μm or less, the release rate of silver ions is increased, and therefore, the antibacterial performance is deteriorated due to the dyeing process or exposure process of acrylic fibers, washing of products, etc., which is not preferable. When crystalline fine particles having a size of 1 μm or more are used, the performance with no practical problem is maintained. Further, the upper limit of the particle size distribution of the crystalline fine particles must be 90% particle size of 5 μm or less.
In addition, the masterbatch usually uses the same solvent as the spinning dope, and in addition to the antibacterial agent, a dispersant or a polymer for adjusting the viscosity may be added.

  The diameter of the spinning nozzle used in the wet spinning process of acrylic fiber is very small compared with the nozzle used in general melt spinning, and the nozzle of 100 μm or less is used especially for the nozzle that spins acrylic fiber with fineness. Is done. For this reason, when there are particulate additives, the amount of coarse particles contained rather than the average particle size affects the spinning stability. For this reason, the upper limit of the particle diameter of the crystalline fine particles added to the acrylic fiber was set here based on the 90% particle diameter. The 90% particle diameter is the particle diameter at which the cumulative value from the smaller particle diameter in the frequency distribution of the particle size distribution measurement result becomes 90%. When this value is larger than 5 μm, the fineness raw yarn of 2.2 dtex or less Is produced by wet spinning, nozzle clogging occurs, and the nozzle pressure rises in a short time.

  The amount of the antibacterial agent supporting silver added to the antibacterial acrylic fiber of the present invention is preferably in the range of 0.2% by mass to 3% by mass. When the amount is less than 0.2% by mass, it is not preferable because sufficient antibacterial properties cannot be obtained when blended at a rate of 50% or less of other materials. When the amount is more than 3% by mass, there is a problem in long-term yarn production stability such as nozzle clogging and nozzle pressure increase, which is not preferable. As a range in which sufficient antibacterial performance is obtained in a state of being blended with other materials and is economically excellent, it is more preferably in a range of 0.5 mass% or more and 1.5 mass% or less.

The acrylic fiber constituting the present invention comprises a polymer containing 50% by mass or more of acrylonitrile. The component other than acrylonitrile may be an unsaturated monomer copolymerizable with acrylonitrile or a polymer thereof.
Examples of unsaturated monomers copolymerizable with acrylonitrile include, for example, acrylic acid esters such as methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, and hydroxypropyl acrylate, ethyl methacrylate, and methacrylic acid. Methacrylic acid esters such as isopropyl, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, diethylaminoethyl methacrylate, acrylic acid, methacrylic acid, maleic acid, itaconic acid, Acrylamide, N-methylolacrylamide, diacetoneacrylamide, styrene, vinyltoluene, vinyl acetate, vinylidene chloride, vinyl bromide, vinylidene bromide, etc. Monomer, and the like.

Further, monomers that are copolymerized for the purpose of improving dyeability include p-sulfophenylmethallyl ether, methallylsulfonic acid, allylsulfonic acid, styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, and alkalis thereof. Metal salts are mentioned. When the acrylonitrile content of the polymer containing acrylonitrile is less than 50% by mass, physical properties such as heat resistance and strength of the raw yarn tend to decrease, which is not preferable.
The cross section constituting the acrylic fiber tow of the present invention is not particularly limited. For example, an arbitrary cross-section such as a broad bean-shaped cross section produced by wet spinning from a normal round nozzle, a round cross section, a flat cross section, or a Y cross section may be employed.

The antibacterial acrylic fiber of the present invention must have a fineness of 2.2 dtex or less. When blending with natural fiber cotton or semi-synthetic fiber rayon, use of acrylic fiber thicker than 2.2 dtex is not preferable because the texture becomes hard and the texture of cotton or rayon is impaired. In order to make the texture as it is or even softer, it must be 2.2 dtex or less. From the viewpoint of texture and spinnability, it is more preferably in the range of 0.5 dtex to 1.7 dtex.
The antibacterial acrylic fiber of the present invention is produced by a wet spinning method. In the wet spinning method, a spinning stock solution obtained by dissolving a polymer containing acrylonitrile in an amount of 50% by mass or more in a solvent is discharged from a spinning nozzle into a coagulation tank in which a solvent and water are mixed, and then coagulated, desolvated, stretched, and dried. A typical spinning method can be employed.

Examples of the solvent used in the spinning dope and the coagulation bath of the wet spinning of the present invention include organic solvents such as dimethylacetamide, dimethylformamide, dimethyl sulfoxide, ethylene carbonate, and acetone, and inorganic solvents such as nitric acid, sodium rhodanate, and zinc chloride. Preferably, an organic solvent is used.
As the coagulation bath, the composition is an aqueous solution containing 30 to 60% by mass of an organic solvent, and the temperature is preferably in the range of 30 to 60 ° C. If the organic solvent is less than 30% by mass, voids are generated in the fiber and the color developability deteriorates, and if it exceeds 60% by mass, the spinnability is lowered and process troubles such as yarn breakage are liable to occur. If the coagulation bath temperature is less than 30 ° C., the spinnability is lowered, and if it exceeds 60 ° C., voids are easily generated in the fiber, which is not preferable.

  In the production of the antibacterial acrylic fiber of the present invention, the nozzle diameter is preferably 60 μm or more. In the production of acrylic fibers having a fineness of 2.2 dtex or less, a nozzle of 60 μm or less is preferably used. However, when an antibacterial agent within the scope of the present invention is added, particles are clogged in the nozzle mouth, and long-time yarn production is performed. If it is carried out, it is not preferable because the yarn-forming stability is lowered. The nozzle diameter is preferably 60 μm or more, and more preferably 75 μm or more from the viewpoint of nozzle clogging. In the production of an acrylic fiber having a non-circular cross section such as a flat or triangular cross section, the circle equivalent diameter of the nozzle cross sectional area may be 60 μm or more.

  Further, JSR = (average discharge linear velocity of polymer) / (take-up speed of coagulated yarn) should be in the range of 0.7 to 1.2. In general, when producing fine-fine acrylic fibers, the spinning dope is increased as much as possible in the range where the yarn can be produced in order to increase productivity, and a nozzle having a nozzle diameter of 60 μm or less is used. However, when the fine antibacterial acrylic fiber of the present invention is produced, a nozzle of 60 μm or more must be used in order to use the particulate antibacterial agent. When the coarse yarn is contained in the fiber yarn under such conditions, the fiber is likely to be broken in the coagulation tank, and as a result, the yarn forming stability is impaired.

  For this reason, when the nozzle opening is set to 60 μm or more so as not to be blocked by crystalline fine particles supporting silver, and an acrylic fiber having a fineness of 2.2 dtex or less is to be spun, the JSR is in the range of 0.7 to 1.2. Thus, the polymer concentration of the spinning dope must be adjusted. When JSR is a value larger than 1.2, it is not preferable because the yarn making stability is impaired for the above-mentioned reason. If the JSR value is less than 0.7, it is possible to produce a yarn up to about 0.5 as the lower limit. However, if the polymer concentration is lowered, the productivity is lowered at the same time, which is not preferable. .

  The polymer concentration is preferably in the range of 18% to 25% by weight. When the concentration is higher than 25% by mass, the viscosity of the spinning dope becomes high, which is not preferable because the nozzle pressure increases and the spinning take-up property decreases. On the other hand, when the content is lower than 18% by mass, problems such as adhesion of the polymer solution discharged in the coagulation bath occur, which is not preferable. The spun undrawn yarn is produced by a normal wet spinning method.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these Examples.

(Method for producing polymer)
A polymer having a reduced viscosity of 1.90 (hereinafter referred to as PAN-A) comprising 93% by mass of acrylonitrile and 7% by mass of vinyl acetate was obtained by an aqueous suspension polymerization method.
(Method for creating antibacterial agent master batch)
PAN-A is dissolved in dimethylacetamide to prepare a dimethylacetamide solution in which PAN-A is 20% by mass. Next, silver supported zeolite fine particles (manufactured by Sinanen Zeomic Co., Ltd., product names: Zeomic-AW10D, -AW80D, -SW80N), PAN-A 20% by mass solution, and dimethylacetamide, silver supported zeolite fine particles 20% by mass, PAN -A 10% by mass and dimethylacetamide 70% by mass were mixed and stirred uniformly, and then passed twice through a sand mill (product name: ST1STS manufactured by Ashizawa Corporation) to obtain an antibacterial agent master batch.

(Particle size distribution measurement)
The particle size distribution in the antibacterial agent master batch was measured using a laser diffraction / scattering type particle size distribution measuring device (product name: HORIBA LA-910, manufactured by Horiba, Ltd.). Dimethylacetamide was used as a dilution solvent. The median size and 90% particle size can be obtained from the attached software Ver. 120 (for WINDOWS (registered trademark)) was used with reference to the calculation results.

(Antimicrobial performance evaluation)
The test was conducted by the following method at the Biological Testing Center of the Japan Chemical Fiber Inspection Association.
This was carried out by the JIS L 1902 bacterial solution absorption method, and the co-test bacteria were Staphylococcus aureus. Two types of pre-test treatments were performed: one treated with boiling water for 20 minutes and the other washed 10 times using JAFET standard detergent according to JIS L 0217, method 103, and bacteriostatic in both tests. When the activity value was 2.2 or more, the antibacterial property evaluation was passed, and when the activity value was smaller than 2.2, it was rejected.

[Example 1, Comparative Examples 1 and 2]
Master batches (hereinafter referred to as MB) were prepared using three types of antibacterial agents (product names: Zeomic AW10D, AW80D, SW80N, manufactured by Sinanen Zeomic Co., Ltd.) as crystalline fine particles supporting silver.
After MB and PAN-A and dimethylacetamide were adjusted to the concentrations of Example 1 and Comparative Examples 1 and 2 shown in Table 1, the whole was heated to 80 ° C., and PAN-A was completely removed. Dissolved in.
After degassing the polymer solution, a gold-width filter (manufactured by Toyobo Co., Ltd., product name: S-618) was passed through a filter processed to 35 mmφ and discharged from a spinning nozzle having a diameter of 60 μm and 400 holes. It was discharged into the coagulation liquid at .17 cc / min. The composition of the coagulation liquid was 56 mass% dimethylacetamide, 44 mass% water, and the temperature was 41 ° C. The polymer yarn discharged into the coagulation liquid is taken up at a take-up speed of 6 m / min, stretched 5.0 times while advancing desolvation in warm water, and then an oil agent is applied and heated by a 150 ° C. hot roller. Drying was performed to obtain a spun tow of 730 dtex. After drying, the tow was subjected to relaxation treatment with pressurized steam of 198 kPa in a batch process to obtain an antibacterial acrylic fiber having a single yarn fineness of 2.2 dtex and a tow fineness of 880 dtex. Nozzle pressure increase showed a pressure difference for 5 hours from 1 hour to 6 hours after nozzle installation.
The acrylic fiber is crimped and cut to 38 mm, and then spun at a ratio of 80% by mass of cotton and 20% by mass of antibacterial acrylic fiber to form a tubular knitted fabric, which is treated with boiling water for 20 minutes. The antibacterial performance evaluation was performed after processing for 15 minutes at 80 degreeC in 0.5 mass% hydrogen peroxide water adjusted to pH11 supposing the exposure process. The results are shown in Table 1.

  The AW80D used in Example 1 had a median diameter of 2.127 μm and a 90% particle diameter of 3.902 μm. No increase in nozzle pressure was observed during running, and no yarn breakage was observed in the coagulation bath. Furthermore, the antibacterial evaluation was also acceptable. The AW10D used in Comparative Example 1 had a median diameter of 2.385 μm and a 90% particle diameter of 5.566 μm. The nozzle pressure increased by 40 kPa from 780 kPa to 820 kPa after running for 5 hours, and it was confirmed that the pressure increased in a short time. No thread breakage in the coagulation bath was observed, and a pass judgment was obtained in antibacterial evaluation. In Comparative Example 2, SW80N was used. Although the median diameter was 0.821 μm and the 90% particle diameter was 1.188 μm, no increase in nozzle pressure was confirmed, but the antibacterial performance evaluation failed.

[Example 2, Comparative Examples 3 and 4]
MB was prepared using crystalline fine particles carrying silver (Sinen Zeomic Co., Ltd., product name: Zeomic AW80D). MB, PAN-A, and dimethylacetamide were adjusted so as to have the concentrations of Table 2 Example 2 and Comparative Examples 3 and 4, and the whole was heated to 80 ° C. to completely dissolve PAN-A. .
After degassing the polymer solution, a gold width filter (manufactured by Toyobo Co., Ltd., product name: S-618) is passed through a filter processed to 35 mmφ, and the spinning nozzles have a diameter of 60 μm, 50 μm, and 70 μm and a hole number of 400, respectively. From this, it was discharged into the coagulation liquid at a discharge rate of 7.39 cc / min. The composition of the coagulation liquid was 56 mass% dimethylacetamide, 44 mass% water, and the temperature was 41 ° C. The polymer yarn discharged into the coagulating liquid is taken up at a take-up speed of 6 m / min, stretched 5.0 times or 4.5 times while proceeding with desolvation in warm water, and then applied with an oil agent. Drying was performed with a hot roller at 0 ° C. to obtain a spun tow of 666 dtex. After drying, the tow was subjected to relaxation treatment with pressurized steam of 198 kPa in a batch process to obtain an antibacterial acrylic fiber having a single yarn fineness of 1.7 dtex and a tow fineness of 680 dtex.
The spinning stability was judged from the occurrence of single fiber breakage in the coagulation bath during spinning for 5 hours from 1 hour after the start of discharge.
A cylindrical knitted fabric was made of acrylic fiber, treated with boiling water for 20 minutes, and then evaluated for antibacterial performance. These results are shown together in Table 2.

  In Example 2, JSR was 0.92, and the spinning stability was good. On the other hand, in Comparative Example 3, the JSR was 0.64, single fiber breakage occurred in the coagulation bath, and the yarn-making stability was poor. After spinning, the nozzle was washed with dimethylacetamide and observed with an optical microscope. As a result, a nozzle opening blocked with antibacterial agent particles was observed. In Comparative Example 4, JSR was 1.25, and single fiber breakage occurred frequently in the coagulation bath, resulting in poor yarn production.

"Example 3, comparative example 5"
MB was prepared using crystalline fine particles carrying silver (Sinen Zeomic Co., Ltd., product name: Zeomic AW80D). MB, PAN-A and dimethylacetamide were adjusted to the concentrations shown in Table 3 Example 3 and Comparative Example 5 and stirred, and then the whole was heated to 80 ° C. to completely dissolve PAN-A.
After degassing the polymer solution, a gold width filter (manufactured by Toyobo Co., Ltd., product name: S-618) was passed through a filter processed to 35 mmφ, and from a spinning nozzle having a diameter of 60 μm and 400 holes, Table 3 Each of the indicated discharge amounts was discharged into the coagulation liquid. The composition of the coagulation liquid was 56 mass% dimethylacetamide, 44 mass% water, and the temperature was 41 ° C. The polymer yarn discharged into the coagulating liquid is taken up at a take-up speed of 6 m / min, stretched 5.0 times or 6.0 times while proceeding with desolvation in warm water, and then an oil agent is applied thereto. Drying was performed with a hot roller at 0 ° C. to obtain a spinning tow of 433 dtex. After drying, the tow was subjected to relaxation treatment with pressurized steam of 198 kPa in a batch process to obtain an antibacterial acrylic fiber having a single yarn fineness of 1.3 dtex and a toe fineness of 520 dtex.
The spinning stability was judged by the occurrence of single fiber breakage in the coagulation bath during spinning for 5 hours from 1 hour after the start of discharge.
A cylindrical knitted fabric was made of acrylic fiber, treated with boiling water for 20 minutes, and then evaluated for antibacterial performance. These results are shown together in Table 3.

  In Example 3, the JSR was 0.92, and the spinning stability was good. On the other hand, in Comparative Example 5, JSR was 1.25, single fiber breakage occurred in the coagulation bath, and the yarn production stability was poor.

Claims (2)

  In a method for producing an antibacterial acrylic fiber having a single fiber fineness of 2.2 dtex or less, an antibacterial agent comprising crystalline fine particles carrying silver having a median diameter of 1 μm or more and a 90% particle diameter of 5 μm or less in a masterbatch As an antibacterial acrylic fiber wet spinning method in which the ratio of the linear velocity of the polymer solution discharged from the nozzle hole and the solidified yarn take-up speed is 0.7 to 1.2.   The wet spinning method for antibacterial acrylic fibers according to claim 1, wherein the addition amount of the crystalline fine particles supporting silver is 0.2 mass% or more and 3 mass% or less.