TWI695098B - Polyamide fiber, fiber structure using the same, and clothing - Google Patents

Abstract

The present invention is a polyamide fiber having a degree of orientation of 0.7 or more and 0.85 or less. For example, a polyamide component having good hygroscopicity and a specific soluble component can be composite fiberized, and specific fiberization conditions can be set, thereby appropriately obtaining polyamide fiber.

Description

Polyamide fiber, fiber structure using the same, and clothing

The present invention relates to a polyamide fiber and a fiber structure using the same. The polyamide fiber constitutes, for example, clothing used for sports or underwear.

All along, because synthetic fibers have good physical properties and chemical properties, they are not only used in clothing applications, but also widely used in industrial applications, with industrially valuable value. The synthetic fibers are, for example: polyester fibers; polyamide fibers such as nylon-6 and nylon-6,6.

However, due to the low hygroscopicity and water absorption of these synthetic fibers, the actual situation is that their application to underwear, undergarments, bed sheets, towels, and other clothing requiring hygroscopicity and water absorption is limited. Therefore, for polyester fibers, for example, a method for improving the hygroscopicity and water absorption, which is the biggest disadvantage of polyester fibers, has been proposed.

More specifically, the following methods have been proposed, namely: a method of post-treating polyester fibers with a hydrophilic post-processing agent; and making the surface or interior of the polyester fibers porous to impart hygroscopicity and water absorption method. However, these methods have problems in that the improvement of the hygroscopicity and the water absorption are insufficient, and the performance imparted is deteriorated by washing.

Therefore, in order to improve the above-mentioned problems, a method has been proposed by using an ethylene-vinyl alcohol-based copolymer, which is a saponified ethylene-vinyl acetate-based copolymer, and, for example, polyester, polyamide, and polyolefin Other thermoplastic polymers are compounded and fiberized to improve dimensional stability (for example, refer to Patent Documents 1 to 3).

Patent Literature

Patent Document 1 Japanese Patent Publication No. 56-005846

Patent Document 2 Japanese Patent Publication No. 55-001372

Patent Document 3 Japanese Patent Publication No. 07-084681

However, in the above-mentioned prior art, there is a problem in that the ethylene-vinyl alcohol-based copolymer has insufficient moisture and heat resistance, which limits its use.

In addition, nylon fiber is used in underwear and socks. However, it is difficult to sufficiently improve the comfort of the fiber structure and clothing made of nylon fiber because it only imparts hygroscopicity to the nylon fiber itself. Therefore, it is necessary to adjust the humidity Hygroscopic and water-absorbing stretch fiber.

Therefore, the present invention has been completed in view of the above-mentioned problems, and an object of the present invention is to provide a polyamide fiber and a fiber structure using the same, and clothing, the polyamide fiber can obtain good hygroscopicity, can be reversible by water absorption and drainage Fibre structure that greatly expands and contracts with good comfort.

In order to achieve the above object, the polyamide fiber of the present invention is characterized in that the degree of orientation is 0.7 or more and 0.85 or less.

According to the present invention, it is possible to provide a fiber structure capable of exerting a good humidity control effect and having a comfort that cannot be provided in the past.

1‧‧‧Polyamide component of composite fiber (component A)

2‧‧‧Soluble component of composite fiber (component B)

3‧‧‧Composite hollow

Fig. 1 is a photograph of a fiber cross section showing an example of a cross section of a composite fiber used to obtain the fiber of the present invention.

2 is a photograph of a fiber cross section showing an example of a cross section of a composite fiber used to obtain the fiber of the present invention.

3 is a photograph of a fiber cross section showing an example of a cross section of a composite fiber used to obtain the fiber of the present invention.

4 is a photograph of a fiber cross section showing an example of a cross section of a composite fiber used to obtain the fiber of the present invention.

[Embodiment of the invention]

The degree of orientation of the polyamide fiber of the present invention is 0.7 or more and 0.85 or less. If the degree of orientation is less than 0.7, sufficient dyeing fastness cannot be obtained, and if the degree of orientation is greater than 0.85, the reversible elongation and shrinkage characteristics due to water absorption and drainage are insufficient, and the mesh of the knitted fabric does not open and close sufficiently. A fiber structure with good comfort cannot be obtained.

That is to say, by using polyamide fibers having a degree of orientation of 0.7 or more and 0.85 or less to manufacture a fiber structure such as a woven fabric, a comfortable woven fabric having a so-called self-adjusting function can be provided. The adjustment function is: when the sweat is absorbed, the polyamide fiber is elongated, so that the mesh of the braid is opened, and the moisture inside the clothing can be discharged; in the case of dry, by the polyamide The fiber shrinks and returns to its original length, thereby closing the mesh of the woven fabric and keeping the temperature inside the clothing.

In addition, the degree of orientation of the polyamide fiber is preferably 0.72 or more, and more preferably 0.75 or more. In addition, the degree of orientation of the polyamide fiber is preferably 0.83 or less, more preferably 0.8 or less, and still more preferably less than 0.80. The degree of orientation of the polyamide fiber is calculated by the measurement method described in the examples described later.

In addition, the polyamide fiber of the present invention preferably has a moisture absorption rate of 5% or more at a temperature of 35°C and a humidity of 95% RH; and a water absorption at a temperature of 20°C and a humidity of 65% RH The elongation is above 5%. If the moisture absorption rate is less than 5%, a sticky and sultry feeling will occur. If the water absorption elongation is less than 5%, the reversible elongation and shrinkage characteristics due to water absorption and drainage will be insufficient, and the mesh of the woven fabric will not be opened or closed sufficiently, and a fiber structure with good comfort cannot be obtained.

That is, by using polyamide fibers having the above-mentioned moisture absorption rate and water absorption elongation rate to manufacture a fiber structure such as a woven fabric, it is possible to provide a woven fabric having the above-mentioned self-adjusting function and having better comfort.

In addition, if the above-mentioned moisture absorption rate and water absorption elongation rate are too large, there is a tendency for deterioration in color fastness to washing, weather resistance, light resistance, chemical resistance, and the like. Therefore, the moisture absorption rate is preferably 5% or more and 30% or less, and more preferably 8% or more and 25% or less. In addition, the water absorption elongation is preferably 5% or more, more preferably 7% or more, further preferably 8% or more, and particularly preferably 10% or more. In addition, the water absorption elongation is preferably 30% or less, more preferably 25% or less, and still more preferably 20% or less. The moisture absorption rate and water absorption elongation of the polyamide fiber are calculated by the measurement method described in the examples described later.

In addition, the crimp elongation of the polyamide fiber is preferably 1.5% or more and 10% or less, more preferably 2% or more and 8% or less, and still more preferably 2.5% or more and 5.8% or less. If the crimping elongation satisfies the condition of 1.5% or more and 10% or less, it will have a raw silk-like (silk-like) feel, so it has a soft touch and a good feel when in contact with the skin.

As the polyamide used in the present invention, for example, polyhexamide (nylon-6), poly-ω-aminoheptanoic acid (nylon-7), polyundecamide (polyundecamide) ( Nylon-11), polyethylene diamine adipamide (nylon-2,6), polytetramethylene adipamide (nylon-4,6), polyhexamethylene Polyhexamethylene adipamide (nylon-6,6), polyhexamethylene sebacamide (nylon-2,10), polyhexamethylene dodecamide (nylon- 6,12), polyoctamethylene adipamide (nylon-8,6), poly ten Methylene hexamethylene diamide (polydecamethylene adipamide) (nylon-10, 6), polydodecyl methylene decane diamide (poly dodecamethylene sebacamide) (nylon-10, 8), etc. In addition, caprolactam/lauryllactam copolymer (nylon-6/12), caprolactam/ω-aminononanoic acid copolymer (Nylon-6/9), caprolactam/hexamethylene adipate copolymer (nylon-6/6,6), dodecylamide/hexamethylene diamine Hexamethylene diamine adipate copolymer (nylon-12/6,6), hexamethylene diamine adipate/hexamethylene diamine sebacate copolymer (nylon -6,6/6,10), ethylene diamine adipate/hexamethylene diamine adipate copolymer (nylon-2,6/6,6), caprolactam Amine/hexamethylene diamine adipate/hexamethylene diamine sebacate copolymer (nylon-6,6/6,10), etc.

Among them, as the polyamide most suitable for the present invention, nylon-6 and nylon-6,6 can be mentioned. From the viewpoint of being inexpensive, highly versatile, and having good hygroscopicity, nylon-6 is more preferable. In addition, as the copolymer, nylon-6/6,6 and nylon-6/12 can be cited. The composition of component 6 and component 12 in nylon-6/12 is not particularly limited. For example, nylon-6/12 with component 12 below 50 mol% is preferred, and component 12 with 40 mol% is more preferred The following nylon-6/12.

In addition, the copolymer of the polyamide may contain an antistatic agent, a lubricant, an anti-blocking agent, a stabilizer, a dye, a pigment, and the like.

The polyamide fiber of the present invention only needs to have the aforementioned degree of orientation, water absorption, and water absorption elongation, and the production method is not limited. For example, a composite fiber composed of a polyamide component (component A) and other soluble components (component B) can be used, and the component B is dissolved to remove the component B, thereby appropriately obtaining polyamide fibers. By using such a composite fiber, since the structure of the polyamide component can be controlled, a single fiber of polyamide can be obtained. The single fiber of polyamide has a specific degree of orientation and has good hygroscopicity and water extensibility. , And can reversibly expand and contract by suction and drainage.

In addition, when the polyamide fiber of the present invention is obtained by the composite fiber as described above, another soluble component (component B) plays an important role in controlling the structure. As the polymer used as the component B, a water-soluble thermoplastic polyvinyl alcohol-based polymer can be used. Preferably, the polyvinyl alcohol polymer has a viscosity-average polymerization degrce of 200 to 500, a saponification degree of 90 to 99.99 mol%, and a melting point of 160 to 230°C. The polyvinyl alcohol-based polymer may be a homopolymer or a copolymer. From the viewpoint of melt spinning, water solubility, and fiber physical properties, it is preferable to use an α-olefin having a carbon number of 4 or less, such as ethylene and propylene, to modify 0.1 to 20 mol% of the whole Copolymerized polyvinyl alcohol. On the other hand, in the composite fiber using the component B, by removing the water-soluble thermoplastic polyvinyl alcohol-based polymer with hot water, the polyamide fiber of the present invention can be appropriately obtained.

In addition, as another example of the component B, a polyester-based polymer (a polyester-based polymer that is easy to reduce alkali) can be used. Compound). As such a polyester-based polymer whose alkali reduction is easy, for example, a copolymerized polyester or polylactic acid can be used. This copolymerized polyester-based system is composed of 1 to 5 mol% of 5-sulfoisophthalic acid sodium (5-sodium sulfoisophthalic acid), 5-30% by weight of polyalkylene glycol (polyalkylene glycol), and conventionally used diol component and dicarboxylic acid component obtained by copolymerization. In the composite fiber using the component B, by performing alkali treatment to remove the polyester-based polymer that is easy to reduce the alkali, the polyamide fiber of the present invention can be appropriately obtained.

Preferably, the fiber cross section of the composite fiber used to form the polyamide fiber of the present invention is a cross section as follows, that is, 50% or more of the cross section of the polyamide component (component A) is dissolved by the soluble component (B Ingredient) Cross-section covered. More preferably, the fiber cross section of the composite fiber used to form the polyamide fiber of the present invention is a cross section in which the entire cross section of the polyamide component (component A) is covered by the component B. That is, it is preferable that the cross-section of the core and sheath of the polyamide component is the core component and the B component is the sheath component, or the sea-island cross section of the polyamide component is the island component and the B component is the sea component.

In the composite fiber of the present invention, the composite ratio (A:B) of the polyamide component (component A) and the soluble component (component B) is preferably 90:10 to 40:60 (weight ratio), more preferably 80:20~60:40 (weight ratio), the ratio of the two can be adjusted according to the fiber shape. In addition, when the B component is small, it may be difficult to control the structure of the polyamide, the desired moisture absorption performance and water absorption elongation performance may not be obtained, and the humidity control may be difficult to control.

The cross-sectional shape of the conjugate fiber of the present invention is not particularly limited as long as the component B is dissolved and removed by hot water treatment or alkali treatment without cracking the component A. For example, it may be of the same core type, eccentric core type, multi-core type. Moreover, in addition to the circular shape as shown in FIGS. 1 and 2, it may also be a multi-lobed shape as shown in FIG. 3, or a special-shaped cross-sectional shape such as a triangle or a flat. Furthermore, as shown in FIG. 4, a hollow portion may be provided inside the component A, and even if the cross-sectional shape is a hollow shape such as a one-hole hollow or a two-hole hollow or more porous hollow, there is no problem.

The single fiber fineness of the polyamide fiber of the present invention is not particularly limited, but the single fiber fineness is preferably 0.03 to 10 dtex. Furthermore, not only long-fiber-type polyamide fibers but also short-fiber or short-cut fiber-type polyamide fibers can be used.

After the combination of the polyamide component (component A) and other soluble components (component B) is determined, the composite fiber of the present invention can be formed using a known composite spinning device.

In order to obtain the fiber of the present invention, the setting of spinning conditions is important, and the most suitable method is the direct spinning drawing method performed at a high speed. In addition, when performing melt spinning at a low speed or a medium speed and then drawing, the heat treatment temperature during drawing is set to less than 100°C, preferably 80°C or less, and the drawing ratio is set to less than 2 times. In addition, when spinning and false twisting are performed simultaneously or continuously after spinning, the temperature is similarly set to less than 100°C, preferably 80°C or less, and the stretching ratio is suppressed to less than 2 times. In addition, if the temperature is set to 100° C. or higher, or the stretch ratio is set to 2 times or more, it may be difficult to control the structure of the polyamide, and the desired degree of orientation, hygroscopicity, and water-absorbing extensibility may not be obtained.

The polyamide fiber of the present invention can be used as various fiber structures (fiber aggregates). Here, "fiber structure" means: multifilament yarn, spun yarn, woven fabric, non-woven fabric, paper, artificial leather, and filler made only of the polyamide fiber of the present invention; Some fibers are woven fabrics and nonwoven fabrics made using the polyamide fibers of the present invention, such as interwoven fabrics made with other fibers such as natural fibers, chemical fibers, synthetic fibers, and semi-synthetic fibers, and using the polyamide of the present invention Amines are knitted fabrics, mixed cotton nonwoven fabrics, fiber laminates, etc. made of processed yarns such as blended yarns, mixed fiber yarns, twisted yarns, interlaced yarns, and crimped yarns.

In addition, the weight ratio of the polyamide fiber of the present invention in the entire knitted fabric or nonwoven fabric is preferably 15% by weight or more, more preferably 18% by weight or more, and particularly preferably 23% by weight or more. In addition, after knitting, weaving, or after making into a non-woven fabric, it is also possible to perform raising processing or other post-processing by card clothing raising method as needed.

In addition, when the polyamide fiber of the present invention is manufactured via the above-mentioned composite fiber, after removing the component B, the obtained polyamide single fiber may be used to manufacture the fiber structure, or the composite fiber may be used to manufacture the fiber After the structure, the B component is removed.

[Examples]

Hereinafter, the present invention will be specifically described based on examples.

(Example 1) (Production of polyamide fiber)

Nylon-6 with a reduced viscosity of 1.80dL/g (concentration in o-chlorophenol of 1g/dL, 30°C) was used as the polyamide component (component A), As a soluble component (component B), a thermoplastic modified polyvinyl alcohol (modified PVA) (manufactured by Kuraray, saponification degree: 98.5, ethylene content: 8.0 mole %, degree of polymerization: 390) was used. Then, the A component and the B component were melted in different extruders and set to nylon-6: modified PVA=60:40 (weight ratio), and the composite spinning nozzle ejected the horizontal Composite fiber cross section. Next, after cooling the yarn ejected from the spinning nozzle by a cross-blowing type cold air device with a length of 1.0 m, a spinning oil agent is applied to the yarn yarn, and the spinning oil agent is composed of an antistatic agent component and a smoothing agent component It does not contain water. Next, it was wound through a roller at a pulling speed of 3500 m/min to produce 111 dtex/24 filament composite fibers. Also, the fiberization processability is good. Next, the obtained composite fiber was made into a circular knitted fabric using a circular knitting machine (28 gauge (GAUGE)). Then, the knitted fabric was subjected to a scouring process using hot water (90° C.×20 minutes) to dissolve and remove the modified PVA, thereby obtaining the polyamide fiber of this example.

(Orientation measurement)

Next, the degree of orientation of the produced polyamide fiber was measured. In addition, the degree of orientation of the polyamide fiber is measured by the following measuring device and measuring conditions.

Measuring device: X-ray diffraction device "D8 Discover with GADDS" manufactured by Bruker AXS and equipped with a secondary detector

Detector: PSPC Hi-STAR

Measurement conditions: current=110mA; voltage=45kV; camera distance=15cm; collimator aperture=0.5mm; exposure time=1200sec; 2θ axis=22°; ω axis=0°; χ axis=90° (equatorial line) , 0° (meridian).

Take a yarn as a sample. The angle of the χ axis is changed so that the equatorial line of the sample becomes vertical and the meridian of the sample becomes horizontal.

Next, the meridional direction secondary data obtained by the above method is converted into an azimuth direction X-ray diffraction intensity curve under the following conditions.

2θ=9.7~11.7°, χ=-150~-30°, step width=0.1°

Finally, the half-value width (Wi(°)) of the peak value of the intensity map obtained by the above method was determined, and the degree of fiber orientation was calculated using the following formula using the simplified method.

Orientation: A=(360-ΣWi)/360

(Measurement of moisture absorption)

Next, in a constant temperature and humidity chamber adjusted to a temperature of 35° C. and a humidity of 90% RH, the produced polyamide fiber is conditioned for 24 hours according to the following formula The moisture absorption rate was determined from the weight of the absolute dry sample and the weight of the humidity-controlled sample. The above results are shown in Table 2.

Moisture absorption rate (%) = (weight of humidity-adjusted sample-weight of absolute dry sample) × 100/weight of absolute dry sample

(Measurement of water absorption elongation)

The produced polyamide fiber was wound into a skein, and after being treated with boiling water for 30 minutes in an untensioned state, it was air-dried and conditioned at a temperature of 20°C and a humidity of 65% RH. After that, the wire subjected to the dry heat treatment for 2 minutes in an uncontacted 160°C environment and in an untensioned state was placed in an environment with a temperature of 20°C and a humidity of 65% RH for 24 hours. Next, a load of 0.88×10 ^-3 cN/dtex was hung on the silk after being left for 24 hours, and the length of the silk measured at this time was regarded as "the length of the silk during drying". After that, the silk was immersed in demineralized water adjusted to 20°C for 1 minute, then the silk was pulled up from the water, and the residual fiber was sandwiched by air-dried filter paper in an environment with a temperature of 20°C and a humidity of 65% RH. moisture in the surface to remove water placed on a horizontal table, after put on 1.5g / cm ² and a weight placed two seconds and remove excess moisture on the fiber surface, after 10 seconds hung 0.88 × 10 ^{- 3 For} the load of cN/dtex, the length measured at this time is taken as "the length of the thread when absorbing water". Then, the water absorption elongation of the polyamide fiber was calculated according to the following formula. In addition, all the measurements were carried out in an environment with a temperature of 20°C and a humidity of 65% RH.

Elongation of water absorption (%) = (length of yarn when absorbing water-length of yarn when drying) / length of yarn when drying × 100

(Wear evaluation)

Using a circular knitting machine, the produced polyamide fiber is made into a circular knitted fabric, and the circular knitted fabric is attached to the elbows and knees of 10 randomly selected panelists (panelist), so that these panelists can After one day in this state, sensory evaluation of stickiness and sultryness was carried out. In addition, with "sticky and sultry feeling very good, very good" set to 2 points, "good" set to 1 point, and "bad" set to 0 points, the total score was evaluated in the following 4 stages . The above results are shown in Table 1.

A: The total score is 15 points or more

B: The total score is 8~14 points

C: Total score is 5~7 points

D: The total score is 4 points or less

(Measurement of roll elongation)

Using a length measuring machine with a frame perimeter of 1.125 m, the polyamide fiber was made into small strands wound 20 times. Next, after heat-treating the obtained small stranded wire in boiling water at 98°C for 5 minutes under no load, it was left in a room with constant temperature and humidity (temperature 20±2°C, relative humidity 65±2%) for one day and one night . A load of 2 mg/d was hung on the fiber after conditioning, and the length L _{1 of} the skein was measured after 1 minute. Next, a load of 0.1 g/d was hung on the small strand, and the strand length L ₂ was measured after 1 minute. The crimp elongation is expressed by the following formula.

Rolling elongation (%) = (L ₂ -L ₁ )/L ₂ ×100

Here, g/d represents the number of grams per 1 Danny.

The above results are shown in Table 1.

(Example 2)

Using 8% by weight of polyethylene glycol with a molecular weight of 2000 and 5 mol% of 5-sodium sulfoisophthalic acid (5-sodium sulfoisophthalic acid) copolymerized, the limiting viscosity number (η) is 0.52 dL/g of polyethylene terephthalate (copolymerized PET) was used as component B, except that polyamide fibers were produced in the same manner as in Example 1, and the degree of orientation and moisture absorption were carried out , Measurement of water absorption elongation, crimp elongation, and evaluation of woven fabric wear. The above results are shown in Table 1.

(Examples 3 to 4)

As shown in Table 1, the component A was changed to nylon-6,6 (Example 3) or nylon-6/12 (Example 4), except that it was produced in the same manner as Example 1. Polyamide fibers were measured, and the orientation, moisture absorption, water absorption elongation, crimp elongation were measured and the woven fabric was evaluated. The above results are shown in Table 1.

(Examples 5-6)

As shown in Table 1, the cross section of the composite fiber was changed to the cross section in FIG. 2 (Example 5) or the cross section in FIG. 4 (Example 6). 1. Polyamide fibers were produced in the same manner, and the orientation degree, moisture absorption rate, water absorption elongation rate, crimp elongation rate measurement, and evaluation of the wearing of the woven fabric were carried out. The above results are shown in Table 1.

(Comparative example 1)

Except that no soluble component (component B) was used, polyamide fibers were produced in the same manner as in Example 1, and the degree of orientation, moisture absorption, water absorption elongation, and crimp elongation were measured And the evaluation of the wear of the woven fabric. The above results are shown in Table 1.

(Comparative example 2)

In the same manner as in Example 1, composite fibers (fineness: 275 dtex) having a cross section as shown in FIG. 1 were ejected using a composite spinning nozzle. Next, after cooling the yarn ejected from the spinning nozzle by a cross-blowing type cold air device with a length of 1.0 m, a spinning oil agent is applied to the yarn yarn, and the spinning oil agent is composed of an antistatic agent component and a smoothing agent component It does not contain water. Next, the roller is pulled at a speed of 1000m/min, Continuous drawing without winding was performed, and heat setting was performed at 150° C., while drawing 2.5 times, and 110 dtex/24 filament composite fibers were produced at a speed of 2500 m/min. Next, using a circular knitting machine (28 pitch), the obtained composite fiber was made into a circular knitted fabric. Then, the knitted fabric was subjected to a scouring process using hot water (90° C.×20 minutes) to dissolve and remove the modified PVA, thereby obtaining polyamide fibers of this comparative example.

Next, in the same manner as in Example 1, the degree of orientation of polyamide fibers, the elongation of water absorption, and the evaluation of the wearing of the woven fabric were performed. In addition, the measurement of moisture absorption rate and crimp elongation was not performed. The above results are shown in Table 1.

(Comparative example 3)

Except that the component A was changed to nylon-12, polyamide fibers were produced in the same manner as in Example 1, and the degree of orientation, water absorption elongation were measured, and the wearing evaluation of the woven fabric was performed. In addition, the measurement of moisture absorption rate and crimp elongation was not performed. The above results are shown in Table 1.

(Comparative example 4)

In the same manner as in Example 1, composite fibers (fineness: 275 dtex) having a cross section as shown in FIG. 1 were ejected using a composite spinning nozzle. Next, after cooling the yarn ejected from the spinning nozzle by a cross-blowing type cold air device with a length of 1.0 m, a spinning oil agent is applied to the yarn yarn, and the spinning oil agent is composed of an antistatic agent component and a smoothing agent component It does not contain water. Next, it was pulled at a speed of 2000 m/min via a roller to obtain an undrawn yarn. Next, using a circular knitting machine (28 pitch), the obtained undrawn yarn was made into a circular knitted fabric. Then, use the knitted fabric The scouring process by hot water (90° C.×20 minutes) dissolves and removes the modified PVA, thereby obtaining the polyamide fiber of this comparative example.

Next, in the same manner as in Example 1, the degree of orientation of polyamide fibers, the elongation of water absorption, and the evaluation of the wearing of the woven fabric were performed. In addition, the measurement of moisture absorption rate and crimp elongation was not performed. The above results are shown in Table 1.

As shown in Table 1, it can be known that since the orientation degree of the polyamide fibers of Examples 1 to 6 is 0.7 or more and 0.85 or less, the water absorption elongation at a temperature of 20° C. and a humidity of 65% RH is 5% or more , Can play a good humidity control effect, the obtained knitted fabric has a good sense of wearing.

On the other hand, it can be seen that the polyamide fibers of Comparative Examples 1 to 3 have an orientation degree of 0.85 or more, so the water absorption elongation at a temperature of 20° C. and a humidity of 65% RH is less than 5%, which is similar to Example 1. Compared with ~6, it can not exert a good humidity control effect, and the obtained knitted fabric is significantly deteriorated in wearing. In particular, it can be known that in Comparative Example 3, due to the hydrophobicity and crystal orientation of the nylon-12 used in the polyamide resin Since it is higher, the degree of orientation is higher as shown in Table 1. As a result, the obtained knitted fabric does not have water-absorbing elongation, and the wearing feeling is significantly deteriorated.

In addition, it can be seen that since the orientation degree of the polyamide fiber of Comparative Example 4 is less than 0.7, the water absorption elongation of the polyamide fiber of Comparative Example 4 becomes too large, and as a result, the wearing feeling is significantly deteriorated.

(Example 7)

Nylon-6 with reduced viscosity of 1.80dL/g (concentration in o-chlorophenol at 1g/dL, 30°C) was used as the polyamide component (component A), and the other soluble component (component B) Thermoplastic modified polyvinyl alcohol (modified PVA) (manufactured by Kuraray, saponification degree: 98.5, ethylene content: 8.0 mole %, degree of polymerization: 380) was used. Then, the A component and the B component were melted in different extruders and set to nylon-6: modified PVA=70:30 (weight ratio), and the composite spinning nozzle ejected the horizontal Composite fiber cross section. Next, after cooling the yarn ejected from the spinning nozzle by a cross-blowing type cold air device with a length of 1.0 m, a spinning oil agent is applied to the yarn yarn, and the spinning oil agent is composed of an antistatic agent component and a smoothing agent component It does not contain water. Next, it was wound through a roller at a pulling speed of 3500 m/min to produce a 111 dtex/24 filament composite fiber. Also, the fiberization processability is good. Next, using a circular knitting machine (28 pitch), the obtained composite fiber was made into a circular knitted fabric. Then, the knitted fabric was subjected to a scouring process using hot water (90° C.×20 minutes) to dissolve and remove the modified PVA.

Next, in the same manner as in Example 1, the degree of orientation, moisture absorption, water absorption elongation, and crimp elongation of the polyamide fiber were measured, and the evaluation of the wearing of the woven fabric. The above results are shown in Table 2.

(Examples 8-9)

In Example 8, an 8% by weight polyethylene glycol with a molecular weight of 2000 and 5 mol% of 5-sodium sulfoisophthalic acid were copolymerized, and the limiting viscosity number [Η] A polyethylene terephthalate (copolymerized PET) of 0.52 dL/g was used as the component B. In Example 9, polylactic acid was used as the soluble component (component B), and in Example 8, In 9, the ratio of nylon-6 and component B was changed to 67:33. Except that, polyamide fibers were produced in the same manner as in Example 7, and the degree of orientation and moisture absorption of the polyamide fibers were performed. The measurement of the rate, water absorption elongation and crimp elongation and the evaluation of the wearing of the woven fabric. The above results are shown in Table 2.

(Examples 10 to 11)

As shown in Table 2, the component A was changed to nylon-6,6 (Example 10) or nylon-6/12 (Example 11), except that it was produced in the same manner as Example 7. Polyamide fibers were measured, and the orientation, moisture absorption, water absorption elongation, crimp elongation were measured and the woven fabric was evaluated. The above results are shown in Table 2.

(Examples 12 to 13)

As shown in Table 2, the cross section of the composite fiber was changed to the cross section in FIG. 2 (Example 12) or the cross section in FIG. 3 (Example 13). 7 Polyamide fibers were produced in the same manner, and the orientation, moisture absorption, water absorption elongation, crimp elongation were measured and the woven fabric was evaluated for wearing. The above results are shown in Table 2.

(Comparative example 5)

In the same manner as in Example 7, composite fibers (fineness: 220 dtex) having a cross section as shown in FIG. 1 were ejected using a composite spinning nozzle. Next, after cooling the yarn ejected from the spinning nozzle by a cross-blowing type cold air device with a length of 1.0 m, a spinning oil agent is applied to the yarn yarn, and the spinning oil agent is composed of an antistatic agent component and a smoothing agent component It does not contain water. Next, the roller was pulled at a speed of 1000 m/min through a roller, continuously stretched without winding, and was heat-set at 150° C. while being stretched to 2.5 times, at a speed of 2500 m/min. Produced 110dtex/24 filament composite fiber. Next, using a circular knitting machine (28 pitch), the obtained composite fiber was made into a circular knitted fabric. Then, the knitted fabric was subjected to a scouring process using hot water (90° C.×20 minutes) to dissolve and remove the modified PVA, thereby obtaining polyamide fibers of this comparative example.

Next, the measurement of the moisture absorption rate and the water absorption elongation of the polyamide fiber and the evaluation of the wearing of the woven fabric were carried out in the same manner as in Example 1. In addition, the measurement of moisture absorption rate and crimp elongation was not performed. The above results are shown in Table 2.

(Comparative example 6)

Except that the component A was changed to nylon-12, polyamide fibers were produced in the same manner as in Example 7, and the measurement of moisture absorption rate and water absorption elongation rate and evaluation of wearing of the woven fabric were performed. In addition, the measurement of moisture absorption rate and crimp elongation was not performed. The above results are shown in Table 2.

As shown in Table 2, it can be known that the polyamide fibers of Examples 7 to 13 have a moisture absorption rate of 5% or more at a temperature of 35°C and a humidity of 95% RH and a temperature of 20°C and a humidity of The water absorption elongation at 65%RH is 5% or more, so it can exert a good humidity control effect, and the obtained knitted fabric has a good wearing feeling.

On the other hand, it can be known that the polyamide fibers of Comparative Examples 5 to 6 have a moisture absorption rate of less than 5% at a temperature of 35°C and a humidity of 95%RH, and at a temperature of 20°C and a humidity of 65%RH The water absorption elongation at the time is less than 5%, and therefore, compared with Examples 7 to 13, a good humidity control effect cannot be exerted, and the obtained knitted fabric is significantly deteriorated in wearing. In particular, it can be seen that in Comparative Example 6, since the hydrophobicity and crystal orientation of nylon-12 used are higher in the polyamide resin, the moisture absorption rate becomes extremely low as shown in Table 2. As a result, the obtained knitted fabric does not have water absorption elongation, and the wearing feeling is significantly deteriorated.

[Industry availability]

The polyamide fiber of the present invention has good hygroscopicity, can be reversibly stretched by water absorption and drainage, and has a mesh ruler with a fiber structure Since the self-adjusting function is changed by the polyamide fiber absorbing and draining water, a comfortable fiber structure can be obtained. For this reason, the polyamide fiber of the present invention is most suitable for use in the field of clothing, especially in sportswear, underwear, lining, stocking, socks, etc., which can exert good performance.

Claims (9)

A polyamide fiber, the degree of orientation of which is 0.7 or more and 0.85 or less, the crimp elongation of the polyamide fiber is 1.5% or more and 10% or less, and the moisture absorption rate at a temperature of 35°C and a humidity of 95%RH is 5 % Or more, and the water absorption elongation at a temperature of 20°C and a humidity of 65% RH is 5% or more. Polyamide fiber as claimed in claim 1, which is obtained by using hot water to remove the water-soluble thermoplastic polyvinyl alcohol-based polymer in the composite fiber composed of the water-soluble thermoplastic polyvinyl alcohol-based polymer and the polyamide . The polyamide fiber according to claim 1, which is obtained by removing the alkali-reducing polyester polymer in the composite fiber composed of the polyester polymer having easy alkali reduction and the polyamide by alkali treatment. The polyamide fiber according to claim 3, wherein the polyamide is nylon-6. The polyamide fiber according to claim 2, wherein the polyamide is nylon-6. Polyamide fiber as claimed in claim 1, which can reversibly expand and contract by suction and drainage. A fibrous structure, at least a part of which is composed of the polyamide fiber according to any one of claims 1 to 6. A garment made of the fibrous structure as in claim 7. For example, the item of clothing in item 8 is one selected from the group consisting of underwear, sportswear, lining, stockings, and socks.

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