JP2007231484A - Polyvinyl alcohol-based fiber and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a PVA (polyvinyl alcohol)-based fiber having practically sufficient mechanical characteristics, readily dispersing various function imparting materials in the interior of the fiber by post-processing and carrying out firm processing/adhesion to the fiber surface by fine pleat shapes thereof, to provide a method for producing the fiber, to provide the PVA-based fiber extremely useful for imparting functions such as flame retardance, antimicrobial, mildew proofing, deodorizing and electroconduction according to the kind of materials thereforand to provide a method for producing the fiber. <P>SOLUTION: The PVA-based fiber has a plurality of pleats at an interval of 10 nm-2 μm in the fiber longitudinal direction. The ratio of the pleat depth to the pleat interval is (5:1) to (1:20). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polyvinyl alcohol (hereinafter abbreviated as PVA) fiber having a fine wrinkle shape in the fiber length direction and a method for producing the same.

  Conventionally, fibers obtained by melt spinning typified by polyester, polyamide, polyolefin and the like as synthetic fibers have relatively various cross-sections, and fibers having wrinkles have been proposed. However, the shape of the wrinkles was rough, and the number was about several to 30 per single yarn, and the distance between the wrinkles was 3 μm or more. Most of the effects are aimed at improving gloss by irregular reflection, improving texture, bulkiness, quick drying of water absorption utilizing capillary action, improving wiping performance, loading and durability of drugs and the like. Such a melt-spun fiber is designed to obtain a spear shape intended for the nozzle shape, and is obtained by spinning and stretching, but there is a limit to the design of the nozzle, Since the cross section becomes mild before the molten polymer is discharged from the nozzle and solidified, the number of wrinkles per single yarn and the interval between them are limited (see, for example, Patent Documents 1 and 2). In addition, a method for dissolving and removing one component of a fiber obtained by composite spinning has been proposed in order to make the wrinkle shape of the fiber obtained by melt spinning finer (see, for example, Patent Documents 3 and 4). However, these methods have problems such as a complicated nozzle structure, the need to remove one component, an increase in the number of processes, and a problem of recovery and disposal. Furthermore, even if these problems are solved and fibers having a fine wrinkle shape are obtained, for fibers such as polyester, polyamide, and polyolefin, various materials are incorporated into the fibers by post-processing up to the inside of the fibers. It's not easy.

  On the other hand, fibers obtained by wet spinning represented by PVA, acrylonitrile, rayon, etc. as synthetic fibers are post-processed with respect to fibers obtained by melt spinning represented by the aforementioned polyester, polyamide, polyolefin, etc. It is relatively easy to incorporate various materials into the fiber. However, these wet-spun fibers are more difficult to control the cross-section than melt spinning, and most of them are currently limited to round, elliptical, flat, etc. It is also a feature of wet spinning that wrinkles occur in the direction. Generally, a fiber having a saddle-shaped cross-section is deformed in the round cross-section during the solidification process to form one or two wrinkles according to the present invention. It is a thing. Thus, even in the fiber obtained by wet spinning, the number of wrinkles is about several, and the interval is about 3 μm at the smallest (see, for example, Patent Documents 5 and 6). In addition to wet spinning, PVA, acrylonitrile, etc. also have fibers obtained by dry spinning, but their cross-sectional shapes are generally round and elliptical, and are very similar to fibers obtained by wet spinning. The present condition is that the proposal of the fiber which has a fine wrinkle shape is not made.

JP 2001-271228 A Japanese Patent Laid-Open No. 3-90612 Republished W001 / 061083 JP 2004-308021 A JP 2001-55621 A JP-A-6-346318

  In the present invention, by providing fine wrinkles in the fiber length direction, the fiber surface area is increased, and various function-imparting materials can be easily dispersed in the fiber by post-processing. It is to provide a PVA-based fiber that can also be subjected to strong processing and adhesion of various function-imparting materials to the fiber surface depending on the shape, and a method for producing the same.

  As a result of intensive studies to obtain the above-described PVA fibers, the present inventors do not require specially expensive equipment for the PVA polymer, and in the normal fiber manufacturing process, the drawing temperature and draw ratio are set. By optimizing, it has been found that PVA fibers having a fine wrinkle shape in the fiber length direction can be manufactured at low cost, and the obtained fiber can easily disperse various function-providing materials in the fiber by post-processing. In addition, it has been found that the fine scissors shape enables the processing and adhesion of various function-imparting materials to the fiber surface.

That is, the present invention is a fiber having a plurality of wrinkles at intervals of 10 nm to 2 μm in the fiber length direction, wherein the ratio of wrinkle depth to wrinkle spacing is 5: 1 to 1:20. Preferably, the PVA fiber is characterized by comprising a PVA polymer having a saponification degree of 88 mol% or more and an average polymerization degree of 1200 to 15000, and more preferably a swelling degree of 1 to 1. It is said PVA type | system | group fiber characterized by being 50%, Furthermore, it is related with the fabric using said PVA type fiber.
In addition, the present invention relates to a method for producing the above PVA fiber, wherein the PVA polymer is spun by a dry method and then stretched at a stretch ratio of 1 to 10 times at a temperature of 100 to 260 ° C. is there.

  ADVANTAGE OF THE INVENTION According to this invention, by providing a fine wrinkle shape in the fiber length direction, the fiber surface area can be expanded, and a PVA fiber that can disperse various function-imparting materials in the fiber by post-processing can be provided. . In addition, the fine wrinkle shape enables strong processing and adhesion of various function-imparting materials to the fiber surface. Depending on the type of material at the time of post-processing application, flame retardant, antibacterial, antifungal, It is extremely useful for imparting functions such as odor and conductivity.

  Hereinafter, the present invention will be specifically described. First, the PVA polymer constituting the PVA fiber of the present invention will be described. The degree of polymerization of the PVA polymer used in the present invention is preferably that having an average degree of polymerization of 1200 to 15000 determined from the viscosity of a 30 ° C. aqueous solution in consideration of the mechanical properties and dimensional stability of the resulting fiber. Those having a low polymerization degree are not preferable because the mechanical strength is lowered. Conversely, use of a polymer having a high degree of polymerization is preferred because it is excellent in terms of strength, heat and humidity resistance, and the like, but the average degree of polymerization is more preferably 1500 to 5000 in view of polymer production costs and fiberization costs.

  The saponification degree of the PVA polymer used in the present invention is preferably 88 mol% or more from the viewpoint of the mechanical properties of the obtained fiber. When the saponification degree of the PVA polymer is lower than 88 mol%, it is not preferable in terms of mechanical properties, process passability, production cost and the like of the obtained fiber.

  The PVA polymer forming the fiber of the present invention is not particularly limited as long as it has a vinyl alcohol unit as a main component, and may have other structural units as desired as long as the effects of the present invention are not impaired. It doesn't matter. Examples of such a structural unit include olefins such as ethylene, propylene, and butylene, acrylic acid, and salts thereof and acrylic esters such as methyl acrylate, methacrylic acid, and salts thereof, and methacrylic acid such as methyl methacrylate. Esters, acrylamide derivatives such as acrylamide and N-methylacrylamide, methacrylamide derivatives such as methacrylamide and N-methylolmethacrylamide, N-vinylamides such as N-vinylpyrrolidone, N-vinylformamide and N-vinylacetamide, poly Allyl ethers having an alkylene oxide in the side chain, vinyl ethers such as methyl vinyl ether, nitriles such as acrylonitrile, vinyl halides such as vinyl chloride, maleic acid, salts thereof, anhydrides thereof, and esters thereof And the like unsaturated dicarboxylic acids and the like. Such a modified unit may be introduced by copolymerization or post-reaction. Of course, as long as the effects of the present invention are not impaired, additives such as antioxidants, antifreeze agents, pH adjusters, masking agents, colorants, oil agents, and special functional agents are included in the polymer depending on the purpose. It may be.

Next, it is important that the PVA fiber of the present invention forms a fine wrinkle shape in the fiber length direction. Specifically, it is important that the distance between the wrinkles in the fiber length direction is 10 nm to 2 μm, and it is important that the ratio of the wrinkle depth to the wrinkle distance is 5: 1 to 1:20. When the distance between the ridges exceeds 2 μm, if the fineness is thin (in other words, the fiber diameter is small), the number of ridges is limited, the fiber surface area cannot be increased greatly, and the function-imparting effect in post-processing is small. Become. On the other hand, when the space | interval of a wrinkle is narrower than 10 nm, it will become difficult to disperse | distribute various function provision materials in a fiber by post-processing. The spacing is preferably 50 nm to 1.5 μm, and more preferably 100 nm to 1 μm.
As for the depth of the wrinkles, the deeper the depth, the greater the surface area of the fiber, which is preferable. However, fibrils are likely to be generated, which causes generation of fluff and the like. On the contrary, if the depth of the wrinkles is shallow, the fiber surface area cannot be increased greatly, and the function-imparting effect in the post-processing is reduced as in the case of the number of wrinkles described above. Therefore, the ratio of the depth of the ridge to the interval between the ridges is more preferably 3: 1 to 1:15, and further preferably 1: 1 to 1:10. In addition, the space | interval and depth of a wrinkle said by this invention are measured by the method mentioned later.

  Although the single fiber fineness of the fiber obtained by this invention is not specifically limited, For example, the fiber of 0.1-1000 dtex, Preferably the fineness of 1-50 dtex can be used widely. The fineness of the fiber can be appropriately adjusted depending on the nozzle diameter, discharge amount, and draw ratio.

  The degree of swelling of the fibers is preferably 1 to 50%, more preferably 15 to 40%. This is because, when the function is imparted by post-processing, the fibers swell to disperse various function-imparting materials to the inside of the fiber. If the degree of swelling is less than 1%, various functional materials cannot be dispersed inside the fiber, or it takes a long time to disperse inside the fiber, or a high temperature is required to take in. It is not desirable because there is a point that it disappears. On the other hand, when the degree of swelling exceeds 50%, it is not preferable because it causes sticking between fibers in a post-processing step or poor process passability due to a decrease in mechanical strength. In addition, the swelling degree of a fiber shows what is measured by the method mentioned later. The various function-imparting materials here will be described later.

  Next, the manufacturing method of the PVA type fiber of this invention is demonstrated. In the present invention, a spinning stock solution in which a PVA polymer is dissolved in water or an organic solvent is used. Examples of the solvent constituting the spinning dope include polar solvents such as water, dimethyl sulfoxide (hereinafter abbreviated as DMSO), dimethylacetamide, dimethylformamide, N-methylpyrrolidone, polyhydric alcohols such as glycerin and ethylene glycol, and the like. And a mixture of swellable metal salts such as rhodan salts, lithium chloride, calcium chloride, zinc chloride and the like, or a mixture of these solvents, or a mixture of these solvents and water. Among these, water and DMSO are particularly preferable. Most suitable in terms of process passability such as cost and recoverability.

  The polymer concentration in the spinning dope varies depending on the composition, polymerization degree, and solvent, but is preferably in the range of 8 to 60% by mass. The liquid temperature at the time of discharging the spinning dope is preferably in a range in which the spinning dope is not decomposed or colored, and specifically 50 to 200 ° C. is preferable. Moreover, as long as the effect of the present invention is not impaired, the spinning dope includes a flame retardant, an antioxidant, an antifreezing agent, a pH adjuster, a concealing agent, and a colorant in addition to the PVA polymer. In addition, additives such as oil agents and special functional agents may be included. Furthermore, these may be used alone or in combination of two or more.

  Such spinning dope may be discharged into a gas from a nozzle to perform dry spinning. Dry spinning is a method of discharging a spinning solution into the air or an inert gas.

  Next, dry heat stretching and heat treatment are performed. The stretching conditions for this purpose are 100 to 260 ° C, preferably 150 to 240 ° C. The draw ratio is preferably 1 to 10 times, more preferably 1.5 to 6 times. A high draw ratio is preferable because the crystallinity and orientation of the fiber are increased, and the mechanical properties of the fiber are remarkably improved. However, when the draw ratio is more than 10 times, the wrinkle shape becomes mild, and also for the purpose of the present invention. This is undesirable because it does not contribute to an increase in the surface area of the fiber. When the stretching temperature is less than 100 ° C., whitening of the fiber occurs, and therefore mechanical properties are deteriorated. On the other hand, if the temperature exceeds 260 ° C., partial melting of the fiber occurs, and in this case, mechanical properties are deteriorated, which is not preferable. By this method, a fiber having fine wrinkles in the fiber length direction of the present invention can be obtained.

  Various function-providing materials referred to in the present invention are not particularly limited. For example, zinc sulfide + manganese for ultraviolet light emission purposes, ferrite for magnetic purposes, zeolite for deodorization / antibacterial purposes, and conductive materials. For the purpose, copper sulfide or the like can be easily applied by post-processing.

  Here, the post-processing of copper sulfide for the purpose of electrical conductivity, which is an example of the function provision in the present invention, will be described in detail. Using the PVA fiber of the present invention, it is immersed in a bath of a compound containing copper ions (concentration = 10 to 400 g / L, temperature = 30 to 80 ° C.) for 3 seconds or more, and then contained in the PVA fiber. For the purpose of sulfiding copper ions, it may be passed through a bath (concentration = 1-100 g / L, temperature = 30-80 ° C.) in which a compound containing sulfide ions is dissolved for 0.1 seconds or more. What is necessary is just to set suitably the density | concentration of each bath, temperature, and immersion time according to the level of the target electroconductive performance, and what is necessary is just to implement a multiple times of post-processing, when high performance improvement is calculated | required. If the fiber of the present invention is used, the post-processing may be carried out with a yarn, or the post-processing may be carried out after forming a fabric form such as a woven fabric, a knitted fabric, or a non-woven fabric. There is almost no difference between the former and the latter.

  Another feature of the fiber of the present invention is that various function-providing materials attached to the surface of the fiber are difficult to drop off because the shape of the ridge is fine. For example, various materials adhering to the inside of the bag have characteristics such that they are better than fibers without wrinkles in terms of washing resistance and wear resistance.

  The fibers of the present invention can be used in any fiber form such as staple fibers, shortcut fibers, filament yarns, spun yarns, strings, ropes, and fabrics such as woven fabrics and knitted nonwoven fabrics. Can be used for a wide variety of applications by incorporating a material capable of imparting the content into the fiber. In this case, examples of fibers that can be used in combination include PVA fibers, polyester fibers, polyamide fibers, and cellulose fibers as long as the intended function is not impaired, and are not particularly limited.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited at all by this Example. In the following examples, the tensile strength of the fiber, the degree of swelling, the distance between wrinkles in the fiber surface length direction, the depth and number thereof, the content of the function-imparting material contained in the fiber, and the functionality (here, Conductivity) and durability (washing durability, flex resistance, wear resistance) are those measured by the following methods.

[Tensile strength of fiber cN / dtex]
In accordance with JIS L1013, a yarn conditioned in advance was measured under the conditions of a test length of 20 cm, an initial load of 0.25 cN / dtex and a tensile speed of 50% / min, and an average value of n = 20 was adopted. The fiber fineness (dtex) was determined by a mass method.

[Swelling degree%]
The fiber was cut to about 1 cm and immersed in water at 30 ° C. for 30 minutes. Thereafter, the fibers were collected by filtration, subjected to centrifugal dehydration for 10 minutes with a centrifuge at a rotation speed of 3000 rpm, and the weight (A) was measured. The dehydrated fiber was left in a dryer at 90 ° C. for 4 hours, completely dried, and the weight (B) was measured. The degree of swelling was calculated by the following formula.
Swelling degree (%) = {weight (A) −weight (B)} / weight (B) × 100

[Shape shape: spacing, depth, number]
Observe the cross section of the fiber with an H-800NA transmission electron microscope (TEM) manufactured by Hitachi, Ltd., and set the distance between the apex of the ridge and the adjacent apex to the distance between the ridges. The maximum distance when the perpendicular is lowered is defined as the depth. In addition, the number of wrinkles at the top of the fiber cross section was counted and used as the number of wrinkles.

[Quantitative measurement of function-providing material contained in fiber by mass%]
The quantitative measurement of the post-processed material containing fibers was performed using an ICP emission analyzer IRIS-AP manufactured by Jarrel Ash.

[Measurement of fiber conductivity (volume resistivity) Ω · cm]
The PVA fiber was dried at a temperature of 105 ° C. for 1 hour, and then allowed to stand for 24 hours or more under conditions of a temperature of 20 ° C. and a humidity of 30% to adjust the humidity. For this fiber, a single fiber test piece having a length of 2 cm was collected, and a voltage of 10 V was applied between both ends of the test piece using a resistance measuring device “MULTITIMETER” manufactured by Yokogawa Hewlett-Packard Company. The resistance value (Ω) was measured. Then, the volume specific resistance value (ρ) (Ω · cm) = R × (S / L) is used to obtain the volume specific resistance value of each test piece, and this is performed for 25 sample pieces, and the average value is obtained as the volume of the sample. The specific resistance value was used. Here, R represents the resistance value (Ω) of the test piece, S represents the cross-sectional area (cm ² ), and L represents the length (2 cm). Here, the cross-sectional area of the test piece was calculated by observing the fiber under a microscope.

[Laundry test]
This was carried out by a method based on the method 103 of JIS L0217. Add 40 ° C water to the water level line indicating the standard amount of water in a household electric appliance washing machine with a centrifugal dehydrator as specified in JIS C 9606, and add a laundry detergent to the standard amount of use. It melt | dissolved and it was set as the washing liquid. A sample and a load cloth were added as needed so that it might become 1:30 to this washing | cleaning liquid, and the driving | operation was started. After the treatment for 5 minutes, the operation was stopped and the sample and the load cloth were dehydrated with a dehydrator. The washing liquid is changed to fresh water of 30 ° C. or less, rinsed for 2 minutes at the same bath ratio, and dehydrated. Then, rinse again for 2 minutes and dehydrate. This series of treatments was repeated 10 times and air-dried in a state not directly affected by sunlight, and durability was evaluated by conductivity before and after the treatment.

[Bending test]
The test piece was evaluated by adjusting the humidity for 24 hours or more in an atmosphere of 20 ° C. and 65% RH. Paper and paperboard-The MIT testing machine used in the folding strength test method (JIS P8115) was used. A load of 4.9 N was applied to the fiber 1000 dtex, a bending angle 270 degrees, a bending frequency 30000 times, a bending speed 175 cpm bending test was performed. The conductivity was measured before and after this treatment, and the bending resistance was evaluated based on the change.

[Abrasion test]
The test piece was evaluated by adjusting the humidity for 24 hours or more in an atmosphere of 20 ° C. and 65% RH. Dye fastness test method for friction Friction tester used for JIS L0849, a test piece was fixed in yarn form to a friction tester type II (Gakushin type), a cotton cloth was fixed to the tip, and a tester was applied with a load of 2N. The reciprocating motion was performed 1000 times on the piece. The conductivity was measured before and after this treatment, and the wear resistance was evaluated based on the change.

[Example 1]
(1) A PVA polymer having a viscosity average polymerization degree of 1700 and a saponification degree of 99.9 mol% was added to water so as to have a PVA concentration of 41.0% by mass, and dissolved by heating at 95 ° C. The obtained spinning dope is spun through a round nozzle having a hole diameter of 0.10 mm and a hole number of 40 at a stock solution discharge rate of 100 cc / min and a take-up speed of 155 m / min, and then stretched 2.0 times at 200 ° C. A PVA fiber was obtained. Table 1 and FIG. 1 show the physical properties and cross-sectional shape of the obtained fiber.
(2) The obtained PVA fiber was introduced into a 75 ° C. aqueous solution in which 230 g / L of copper nitrate manufactured by Wako Pure Chemical Industries, Ltd. was dissolved so that the residence time was 5 minutes. Yarn was introduced into a 25 ° C. water bath in which 50 g / L of sodium sulfide manufactured by Yakuhin Co., Ltd. was dissolved so that the residence time was 2 minutes. Table 1 shows the results of evaluating the conductive performance of fibers obtained by repeating this treatment twice and then drying with hot air at 100 ° C. The fiber thus obtained was excellent in initial conductive performance and durability.

[Example 2]
(1) Using the same spinning stock solution as in Example 1 and spinning through a round nozzle with a hole diameter of 0.10 mm and a hole number of 40 at a stock solution discharge rate of 100 cc / min and a take-up speed of 155 m / min, at 240 ° C. Ten-fold stretching was performed to obtain a PVA fiber. Table 1 shows the physical properties and cross-sectional shape of the obtained fiber.
(2) In order to make the obtained PVA fiber conductive, the yarn was introduced into a 75 ° C. aqueous solution in which 230 g / L of copper nitrate manufactured by Wako Pure Chemical Industries, Ltd. was dissolved so that the residence time was 5 minutes. Subsequently, the yarn was introduced into a 25 ° C. water bath in which 50 g / L of sodium sulfide manufactured by Wako Pure Chemical Industries, Ltd. was dissolved so that the residence time was 2 minutes. Table 1 shows the results of evaluating the conductive performance of fibers obtained by repeating this treatment twice and then drying with hot air at 100 ° C. The obtained fiber was excellent in initial conductive performance and durability.

[Comparative Example 1]
(1) A polymer obtained by melting polypropylene at 280 ° C. was melt-spun through a round nozzle having a hole diameter of 0.40 mm and a hole number of 48 at a discharge rate of 48 g / min and a take-up speed of 200 m / min. After stretching 5.0 times in a water bath, it was dried at 100 ° C. to obtain a round polypropylene fiber. Table 1 shows the physical properties and cross-sectional shape of the obtained fibers.
(2) Introducing the resulting polypropylene fiber into a 75 ° C. aqueous bath in which 230 g / L of copper nitrate manufactured by Wako Pure Chemical Industries, Ltd. was dissolved was introduced so as to have a residence time of 5 minutes, Subsequently, the yarn was introduced into a 25 ° C. water bath in which 50 g / L of sodium sulfide manufactured by Wako Pure Chemical Industries, Ltd. was dissolved so that the residence time was 2 minutes. Table 1 shows the conductive performance evaluation results of the fiber obtained by repeating this treatment twice and then drying with hot air at 100 ° C. Granting was not possible.

[Comparative Example 2]
(1) Using the same spinning stock solution as in Example 1 and spinning through a round nozzle with a hole diameter of 0.10 mm and a hole number of 40 at a stock solution discharge rate of 100 cc / min and a take-up speed of 155 m / min, at 240 ° C. The PVA fiber was obtained by stretching 12 times. Table 1 shows the physical properties and cross-sectional shape of the obtained fiber.
(2) In order to make the obtained PVA fiber conductive, the yarn was introduced into a 75 ° C. aqueous solution in which 230 g / L of copper nitrate manufactured by Wako Pure Chemical Industries, Ltd. was dissolved so that the residence time was 5 minutes. Subsequently, the yarn was introduced into a 25 ° C. water bath in which 50 g / L of sodium sulfide manufactured by Wako Pure Chemical Industries, Ltd. was dissolved so that the residence time was 2 minutes. Table 1 shows the conductive performance evaluation results of the fibers obtained by repeating this treatment twice and then drying with hot air at 100 ° C. The obtained fibers are inferior in initial conductive performance and durability. It was.

[Comparative Example 3]
(1) PVA having a viscosity average polymerization degree of 1700 and a saponification degree of 99.9 mol% was added to water so as to have a PVA concentration of 15.8% by mass, and dissolved by heating at 95 ° C. Using this spinning solution, it was spun into a coagulation bath consisting of a saturated sodium sulfate aqueous solution at a discharge rate of 330 cc / min and a take-up speed of 10 m / min through a round nozzle having a hole diameter of 0.08 mm and a hole number of 4000. The film was stretched 4 times, and then formalized by dipping in a bath of formalin 28 g / l, sulfuric acid 240 g / l, sodium sulfate 130 g / l, and 75 ° C. for 30 minutes to obtain a PVA fiber. Table 1 shows the physical properties and cross-sectional shape of the obtained fiber.
(2) In order to make the obtained PVA fiber conductive, the yarn was introduced into a 75 ° C. aqueous solution in which 230 g / L of copper nitrate manufactured by Wako Pure Chemical Industries, Ltd. was dissolved so that the residence time was 5 minutes. Subsequently, the yarn was introduced into a 25 ° C. water bath in which 50 g / L of sodium sulfide manufactured by Wako Pure Chemical Industries, Ltd. was dissolved so that the residence time was 2 minutes. Table 1 shows the conductive performance evaluation results of the fibers obtained by repeating this treatment twice and then drying with hot air at 100 ° C. The obtained fibers are inferior in initial conductive performance and durability. It was.

  As is clear from the results of Table 1, FIG. 1 and FIG. 2, the PVA fiber of the present invention has a predetermined wrinkle in the fiber surface length direction, so that a material for imparting functionality to the inside of the fiber ( In particular, in FIG. 2, copper sulfide for imparting conductivity is uniformly dispersed, and not only the initial performance but also durability is excellent, and PVA has original mechanical properties. On the other hand, even if it is a fiber using a polymer other than PVA or a PVA-based fiber and does not have a predetermined wrinkle in the fiber surface length direction, the intended functionality is not imparted.

  ADVANTAGE OF THE INVENTION According to this invention, the PVA type fiber which becomes possible [disperse | distributing various materials inside a fiber by post-processing] can be provided. In addition, depending on the type of the material, it is extremely useful for imparting functions such as flame retardancy, antibacterial, antifungal, deodorant, and conductivity. Furthermore, the PVA fiber of the present invention does not require a particularly expensive process and can be manufactured at a low cost by ordinary spinning and drawing processes.

The fiber surface photograph which shows an example of the PVA fiber of this invention. The fiber cross-section photograph which shows an example of the state by which copper sulfide is uniformly disperse | distributed inside the fiber in the PVA fiber of this invention.

Claims (4)

  A polyvinyl alcohol fiber having a plurality of wrinkles at intervals of 10 nm to 2 μm in the fiber length direction, wherein a ratio of wrinkle depth to wrinkle spacing is 5: 1 to 1:20.   The polyvinyl alcohol fiber according to claim 1, comprising a polyvinyl alcohol polymer having a saponification degree of 88 mol% or more and an average polymerization degree of 1200 to 15000.   The degree of swelling is 1 to 50%, and the polyvinyl alcohol fiber according to claim 1 or 2. The polyvinyl alcohol fiber according to any one of claims 1 to 3, wherein the polyvinyl alcohol polymer is spun by a dry method and then stretched at a stretch ratio of 1 to 10 at a temperature of 100 to 260 ° C. Manufacturing method.

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