JP2007231474A - Thick and thin conjugated fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thick and thin conjugated fiber having a characteristic of "opacity" in wet state and imparting improved windbreaking and heat retaining property to a cloth by decrease of gap, and stably expressing the characteristic after being subjected to a dyeing and finishing process, and imparts a spun like feeling. <P>SOLUTION: The conjugated fiber has a fiber cross sectional shape in which a polyester component and a polyamide component are bonded, and the conjugated fiber has a crimping percentage DC of 4.0-12.0%, and has a crimping percentage HC after being soaked water of 5.0-13.0%, and has a difference ΔC in crimping percentage of 0.3-8.0%, which is represented by following formula, after being subjected to the following treatments of a boiling water treatment for 30 min, dry heat treatment at 100°C for 30 min to crimp the fiber and then heat treating the fiber at 160°C for 1 min, wherein the fiber is the thick and thin conjugated fiber having a thick part and a thin part in longitudinal direction. Formula: ΔC(%)=HC(%)-DC(%). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thick and thin composite fiber whose crimping rate reversibly changes greatly depending on humidity. More specifically, a fabric that exhibits excellent crimp rate change characteristics even after dyeing and finishing processes, has a characteristic that voids when wet are lower than those when dried, and has a spun-like texture is obtained. It relates to a thick and fine composite fiber.

  It has been well known that natural fibers such as cotton, wool and feathers reversibly change in form and crimp rate due to changes in humidity. Studies have been conducted for a long time to provide a function for synthetic fibers, and proposals for side-by-side type composite fibers of nylon 6 and modified polyethylene terephthalate have already been made in Patent Documents 1 and 2, etc. These known composite fibers have not been put to practical use because the reversible crimp rate change due to humidity change is small.

  Thereafter, Patent Documents 3 and 4 and the like with improved heat treatment conditions have been proposed. Furthermore, the thing which applied the said prior art, such as patent documents 5-8 is proposed. However, in the above-described conventional technology, the change in the crimp rate becomes small after passing through processes such as dyeing and finishing, and the actual situation is that the practical level has not been reached.

  On the other hand, in Patent Document 9, an attempt is made to improve the above-mentioned problem by using a polyamide component and a polyamide component having a high moisture absorption rate, such as nylon 4, in which the polyester component and the polyamide component are joined in a flat shape. However, nylon 4 has poor yarn-making stability, the crimping performance is lowered after heat treatment, and there is a limit in practical use even for such a composite fiber.

  In addition to ensuring stable quality from the yarn-making surface and finished surface as described above, in recent years, “translucency” has become a problem due to diversification of required characteristics. In other words, if ordinary woven or knitted fabrics made of synthetic fibers or natural fibers are used for swimming wear, sports wear, etc., the fabric becomes wet through water or rain, resulting in easy see-through and reduced wind resistance and heat retention. Such a problem also occurs. Furthermore, with the diversification of required properties, there is a demand for fibers having not only mere functionality but also excellent texture.

Japanese Examined Patent Publication No. 45-28728 Japanese Patent Publication No.46-847 JP 58-46118 A JP 58-46119 A Japanese Patent Laid-Open No. 61-19816 JP 2003-82543 A JP 2003-41444 A JP 2003-41462 A JP-A-3-213518

  The present invention has been made against the background of the above-described conventional technology, and its purpose is to have a property of “not transparent” even when wet with water, and further, the voids of the fabric are reduced at that time, thereby preventing wind and heat retention. The present invention provides a thick and thin composite fiber that can stably produce these excellent characteristics even after undergoing steps such as dyeing and finishing, and can obtain a spun-like texture. There is.

According to the studies by the present inventors, the above object is a composite fiber having a fiber cross-sectional shape in which a polyester component and a polyamide component are joined, and the composite fiber is treated with boiling water for 30 minutes, and further at 100 ° C. Crimp was developed by dry heat treatment for 30 minutes, and the crimp ratio DC of the fiber subjected to dry heat treatment at 160 ° C. for 1 minute was 4.0 to 12.0%, and the fiber was further crimped after being immersed in water. The rate HC is 5.0 to 13.0%, the difference ΔC between these crimping ratios expressed by the following formula is 0.3 to 8.0%, and the thick part and the details in the longitudinal direction It has been found that this can be achieved by a thick and thin composite fiber characterized by having the same.
ΔC (%) = HC (%) − DC (%)

  According to the present invention, it has a characteristic of “not transparent” even when wetted by a synergistic effect of the crimp rate change and the thick details, and further, the windproof property and the heat retaining property are improved by reducing the gap of the fabric, It is possible to provide a fine composite fiber that exhibits a spun-like texture and that stably exhibits these characteristics even after undergoing processes such as dyeing and finishing. For this reason, the above-mentioned thick and thin composite fiber is extremely practical, and at the same time, has an unprecedented high comfort and aesthetic effect as a final product such as clothing.

  Examples of the polyester component constituting the thick and fine composite fiber of the present invention include polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and the like. Among these, polyethylene terephthalate is more preferable from the viewpoint of cost and versatility.

  In the present invention, the polyester component is preferably a modified polyester in which 5-sulfoisophthalic acid is copolymerized. At that time, if the copolymerization amount of 5-sodium sulfoisophthalic acid is too large, peeling is less likely to occur at the bonding interface between the polyamide component and the polyester component, but excellent crimping performance cannot be obtained. In order to improve the shrinkage performance, it is necessary to promote crystallization. However, if the temperature of the drawing heat treatment is increased to promote crystallization, yarn breakage tends to occur, which is not preferable in terms of yarn production. On the other hand, the amount of copolymerization is too small, and the crystallization of the polyester component is facilitated by the stretching heat treatment, and excellent crimping characteristics can be obtained. On the other hand, peeling easily occurs at the bonding interface between the polyamide component and the polyester component. It is not preferable because it is in a tendency. For this reason, the copolymerization amount of 5-sodium sulfoisophthalic acid is preferably 2.0 to 4.5 mol%, and more preferably 2.3 to 3.5 mol%.

  On the other hand, if the intrinsic viscosity of the polyester component is too low, the yarn-forming property is lowered and fluff is easily generated, which is not preferable in terms of industrial production and quality. On the other hand, even if the intrinsic viscosity is too high, the spinnability and stretchability on the polyester component side are lowered by the thickening action by copolymerization of 5-sodium sulfoisophthalic acid, and fluff and yarn breakage are likely to occur. Become. Accordingly, the intrinsic viscosity of the polyester component is preferably 0.30 to 0.43, and more preferably 0.35 to 0.41.

On the other hand, the polyamide component is not particularly limited as long as it has an amide bond in the main chain, and examples thereof include nylon 4, nylon 6, nylon 66, nylon 46, nylon 12, and the like. Nylon 6 and nylon 66 are particularly preferable from the viewpoints of stability and versatility. The polyamide component may be copolymerized with other components based on these.
Further, both components described above may contain pigments such as titanium oxide and carbon black, known antioxidants, antistatic agents, light-proofing agents, and the like.

  The conjugate fiber of the present invention is a conjugate fiber having a fiber cross-sectional shape in which the polyester component, the polyester component, and the polyamide component are joined. As a composite form of the polyamide component and the polyester component, a form in which both components are joined in a side-by-side manner is preferable from the viewpoint of crimp development. The cross-sectional shape of the composite fiber may be a circular cross-section or a non-circular cross-section. For example, a triangular cross-section or a square cross-section can be adopted as the non-circular cross-section. In addition, a hollow part may exist in the cross section of the said composite fiber.

  The ratio of the polyester component to the polyamide component in the fiber cross section is preferably 30/70 to 70/30, more preferably 60/40 to 40/60, based on the area.

  In the present invention, the above-mentioned composite fiber is treated with boiling water for 30 minutes, and further subjected to a dry heat treatment at 100 ° C. for 30 minutes to develop crimps. The requirements regarding the rate DC, the crimp rate HC after immersion in water, and the difference ΔC between these crimp rates are satisfied at the same time, and the composite fiber has thick portions and details in the longitudinal direction. It is essential. As a result of the study by the present inventors, the composite fiber having such crimp characteristics has an increased crimp rate due to moisture absorption, and the fabric does not become “translucent” even when wetted with water. It has been found that the air gap and the heat retention are improved due to clogging, and the properties are stably exhibited even after dyeing and finishing processes. Further, it has been found that by having a thick portion and details in the length direction of the fiber, especially when the thick portion is present, the change in the crimping rate is increased, and the effect of preventing “through” is increased.

  That is, the crimp ratio DC needs to be 4.0 to 12.0%, preferably 4.5 to 10.0%, more preferably 5.0 to 8.5%. If the crimp ratio DC is less than 4.0%, the texture when used as a fabric tends to deteriorate. On the other hand, when the crimp ratio DC exceeds 12.0%, the crimp ratio DC tends to be larger than the crimp ratio HC after being immersed in water, and it is difficult to see through and the gap of the fabric is reduced, thereby preventing wind and heat retention. This is not preferable because it tends to be difficult to obtain a fabric with improved resistance.

  The crimp ratio HC after immersion in water is 5.0 to 13.0%, preferably 5.5 to 11.0%, and more preferably 6.0 to 10.5%. A crimping ratio HC of less than 5.0% is not preferable because the crimping ratio after water immersion is too low, and the intended effect of preventing see-through and the effect of improving windproof and heat retaining properties are insufficient. On the other hand, when the value of the crimping ratio HC exceeds 13.0%, the fabric shrinks greatly when it contains water, which is not practical and the texture is lowered.

  Further, the difference ΔC between the HC and DC is 0.3 to 8.0%, preferably 1.0 to 5.5%, more preferably 1.5 to 4.5%. When ΔC is less than 0.3%, the effect of improving the crimp rate after immersion in water is small, and it is difficult to see through when wet with water, and the fabric has improved void resistance and heat retention by reducing the gaps in the fabric. Not preferable. On the other hand, when ΔC exceeds 8.0%, it is not practical because the fabric shrinks greatly when water is contained, and the texture is also lowered.

  The conjugate fiber of the present invention is excellent not only in functionality but also in texture. That is, the composite fiber of the present invention has a thick portion and details in the longitudinal direction, and is characterized by exhibiting a spun-like texture using this as a fabric. Moreover, in this invention, it is preferable that U% which shows the thickness degree of a composite fiber is 2.5 to 15.0%, 3.5 to 14.5% is more preferable, and 4.0 to 13 More preferably, it is 5%. When U% is less than 2.5%, when it is made into a fabric, a spun-like texture is not obtained, which is not preferable. Moreover, the characteristic which prevents the see-through at the time of moisture absorption also tends to deteriorate. On the other hand, when U% exceeds 15%, the strength of the composite fiber is lowered, and its handling becomes difficult.

  The total fineness of the conjugate fiber of the present invention may be 40 to 200 dtex, and the single yarn fineness is 1 to 6 dtex. In addition, you may perform a confounding process as needed.

  For producing the conjugate fiber of the present invention, for example, as described in JP-A No. 2000-144518, the high-viscosity component side and the low-viscosity side discharge holes are separated, and the high-viscosity side discharge linear velocity is set. Obtained by using a spinneret that has been reduced (increase the discharge cross-sectional area), let the molten polyester pass through the high-viscosity side discharge holes, pass the molten polyamide through the low-viscosity side discharge holes, join them, and cool and solidify them. Can do. Stretching of the spun yarn taken up can be performed by either winding it once and then stretching it separately, heat-treating it as necessary, stretching it without winding it once, or stretching it directly as needed. Can also be adopted. As the spinning speed, a relatively low speed of 1000 to 3500 m / min is preferably employed.

  In addition, for example, when stretching and heat setting are performed by direct stretching using a stretching machine having two rollers, the first roller temperature needs to be preheated at a temperature of less than 60 ° C. When this preheating temperature exceeds 60 ° C., it becomes difficult to obtain the desired thickness. Subsequently, the method of heat-setting a 2nd roller as 80-170 degreeC is employable. Further, the stretching ratio performed between the first roller and the second roller may be set in consideration of the above-mentioned thickness, for example, low so that the breaking elongation of the composite fiber is at least 55% or more. By setting the conditions for magnification stretching, the thick and thin composite fiber of the present invention can be easily obtained.

  In order to develop crimp in the conjugate fiber of the present invention, first, this is treated with boiling water. Thereby, the crimp by which the polyester component is arrange | positioned inside is obtained. However, in this state, since moisture is contained, the polyamide grows due to the plasticizing effect of water, so the crimp itself changes over time and becomes unstable. Except for stabilizing crimp. As a standard for stabilizing the crimp characteristics, the crimp characteristics are as follows. The composite fiber as described above is treated with boiling water for 30 minutes, and further subjected to dry heat treatment at 100 ° C. for 30 minutes to develop crimps. The composite fiber evaluated by such a method must be subjected to a dry heat treatment for a minute, and a fabric having the desired performance can be obtained even if heat treatment is performed in a finishing step that is usually performed.

  The composite fiber of the present invention can be used alone or as a mixed yarn mixed with other fibers. Moreover, it can be used as false twisted yarn by further false twisting if necessary, and it can also be used as a composite false twist with different elongation.

The conjugate fiber of the present invention can be used in various applications for clothing, and can be used particularly preferably in applications that require comfort, such as swimwear, various sportswear, inner materials, uniforms, and the like.
Needless to say, the present composite fiber and natural fiber can be further combined and further effective, and a combination of urethane or polytrimethylene terephthalate may be used for further stretching.

Hereinafter, the present invention will be described more specifically with reference to examples. In addition, each item in an Example was measured with the following method.
(1) Intrinsic viscosity of polyamide and polyester Polyamide was measured at 30 ° C. using m-cresol as a solvent. The polyester was measured at 35 ° C. using orthochlorophenol as a solvent.

(2) Good yarn-making property and stretchability: Spinning is performed continuously for 10 hours, and the yarn-breaking property is good with 0 to 1 yarn breakage.
Slightly poor: Spinning is carried out continuously for 10 hours, and the yarn breakage is slightly worse, 2 to 4 times.
Defective: Spinning is performed continuously for 10 hours, and yarn breakage is 5 or more times.

(3) Interfacial exfoliation between polyamide component and polyester component A 1070-fold color cross-sectional photograph of an arbitrary cross section of the composite fiber was taken, and the state of interfacial exfoliation between the polyamide component and the polyester component in the filament was investigated.
None: There was almost no peeling (0 to 1) at the interface.
Slightly present: Peeling at the interface was present in 2 to 10 filaments.
Existence: Peeling at the interface was present in almost all filaments.

(4) Strength (cN / dtex), elongation (%)
After leaving the fiber sample in a room maintained at a constant temperature and humidity of 25 ° C. and 60% humidity for a whole day and night, the sample length of 100 mm was set on a tensile tester Tensilon manufactured by Shimadzu Corporation, and the speed was 200 mm / min. The strength and elongation at break were measured.

(5) U%
Using an Evness Tester manufactured by Keisokuki Kogyo Co., Ltd., measurement was performed under the conditions specified under the half inert conditions.

(6) Crimp rate DC, crimp rate HC after water immersion, and their difference ΔC
A 2700 dtex case was made from the composite fiber and treated in boiling water for 30 minutes under a light load of 6 g (2.2 mg / dtex). The moisture was removed by lightly removing with a filter paper, followed by drying at 100 ° C. for 30 minutes under a load of 6 g (2.2 mg / dtex). Furthermore, this casserole was heat-treated at 160 ° C. for 1 minute under a load of 6 g (2.2 mg / dtex) to obtain a measurement sample.
(A) Crimp rate DC (%)
The measurement material (cassette) subjected to the above treatment was treated under a load of 6 g (2.2 mg / dtex) for 5 minutes, and then this skein was taken out and further 600 g (total 606 g: 2.2 mg / dtex + 220 mg / dtex). ) And left for 1 minute to determine the length L0 of the case. Next, the load of 600 g was removed, and the load was left for 1 minute under a load of 6 g (2.2 mg / dtex), and the length L1 was determined. The crimp rate DC was determined from the following calculation formula.
DC (%) = L0−L1 / L0 × 100
(B) Crimp rate HC (%) after water immersion
Using the same case after obtaining the crimp rate DC, it was treated in water (room temperature) for 10 hours under a load of 6 g (2.2 mg / dtex). The casserole was wiped off with a filter paper, and a load of 600 g (total 606 g: 2.2 mg / dtex + 220 mg / dtex) was further applied and left for 1 minute to determine the length L2 of the casserole. Next, the load of 600 g was removed, and the product was left for 1 minute under a load of 6 g (2.2 mg / dtex), and the length L3 was determined. The crimp rate DC after water immersion was calculated | required from the following formula.
HC (%) = L2-L3 / L2 × 100
(C) ΔC (%)
The difference ΔC between the above-described crimp rate DC and the crimp rate HC after water immersion was determined by the following equation.
ΔC (%) = HC (%) − DC (%)

(7) Characteristics of cylinder knitting The composite fiber was knitted in a cylinder, boiled with a cationic dye, set in a dry heat at 160 ° C. for 1 minute after washing with water, and used as a measurement sample. Water is dropped onto this tubular knitting, and the situation of the water dripping part and its surroundings is investigated with a side photograph (magnification 200) of the tubular knitting. Was judged.
(A) Stitch change (degree of reduction of voids)
Good: The stitches are remarkably shrunk by water dripping (voids are reduced).
Slightly poor: Almost no change in stitches due to water dripping (almost no change in voids).
Defect: The stitches are rather elongated due to water dripping (the voids are enlarged).
(B) See-through prevention (opacity)
Good: The sense of transparency is reduced by dripping water.
Slightly poor: No change in the sense of transparency due to dripping water
Defect: The feeling of see-through is increased by dripping water.

(8) Texture The composite fiber was knitted, boiled with a cationic dye, washed with water, set in a dry heat at 160 ° C. for 1 minute, used as a measurement sample, and evaluated by its tactile sensation.
Good: Span-like texture.
Defect: The spanlike texture is insufficient.

[Example 1]
Nylon 6 having an intrinsic viscosity [η] of 1.3 and modified polyethylene terephthalate copolymerized with 3.0 mol% of 5-sodium sulfoisophthalic acid having an intrinsic viscosity [η] of 0.39 are each 270 ° C. Melted at 290 ° C., formed a side-by-side type composite yarn at a discharge rate of 16.9 g / min using a composite spinneret described in Japanese Patent Application Laid-Open No. 2000-144518, and applied cooling solidification / oil agent After that, the filament was preheated with a first roller at a speed of 1800 m / min and at a temperature RT (room temperature), and then stretched and heat-treated between a second roller heated at a speed of 3050 m / min and a temperature of 130 ° C. 69 times) to obtain a thick and thin composite fiber with a winding of 110 dtex 24 fil. The spinning property and stretchability were very good, and the yarn was continuously spun for 10 hours and there was no breakage. The results are shown in Table 1.

[Examples 2-5, Comparative Examples 1-2]
A composite fiber was obtained in the same manner as in Example 1 except that the first roller speed was changed as shown in Table 1. The results are shown in Table 1.

[Examples 6 to 7, Comparative Example 3]
A composite fiber was obtained in the same manner as in Example 1 except that the first roller temperature was changed as shown in Table 1. The results are shown in Table 1.

[Examples 8 to 9, Comparative Example 4]
A conjugate fiber was obtained in the same manner as in Example 1 except that the second roller temperature was changed as shown in Table 1. The results are shown in Table 1.

[Examples 10-11, Comparative Examples 5-6]
A composite fiber was obtained in the same manner as in Example 1 except that the copolymerization amount of 5-sodium sulfoisophthalic acid as a modified polyethylene terephthalate component was changed as shown in Table 1. The results are shown in Table 1.

[Examples 12 to 13, Comparative Examples 7 to 8]
A composite fiber was obtained in the same manner as in Example 1 except that the intrinsic viscosity [η] of the modified polyethylene terephthalate component was changed as shown in Table 1. The results are shown in Table 1.

[Examples 14 to 15, Comparative Example 9]
A composite fiber was obtained in the same manner as in Example 1 except that the discharge amount of each component and the speed of the second roller were changed as shown in Table 1. The results are shown in Table 1.

  According to the present invention, it is possible to provide a composite fiber in which the crimp rate reversibly changes depending on humidity, and has a property of “not transparent” even when wetted with water. The composite fiber which exhibits the outstanding function that windproof property and heat retention improve by decreasing can be provided. Further, the composite fiber exhibits a stable crimp rate change characteristic even after the dyeing / finishing process, and thus is extremely practical and unprecedented. In addition, when used as a fabric, a spun-like texture is obtained, and not only has excellent comfort as a final product such as clothing, but also has a high quality, and its industrial value is extremely high. Is.

Claims (3)

A composite fiber having a cross-sectional shape of a fiber in which a polyester component and a polyamide component are bonded. The composite fiber is treated with boiling water for 30 minutes, and further subjected to a dry heat treatment at 100 ° C. for 30 minutes to develop crimps. The crimp rate DC of the fiber heat-dried at 160 ° C. for 1 minute is 4.0 to 12.0%, and the crimp rate HC after water immersion is 5.0 to 13.0%. A thick and thin composite fiber characterized in that the difference ΔC between these crimping ratios expressed by the following formula is 0.3 to 8.0% and has a thick portion and details in the longitudinal direction of the fiber.
ΔC (%) = HC (%) − DC (%)   The thick and fine composite fiber according to claim 1, wherein U% of the thick and fine composite fiber is 2.5 to 15.0%.   The polyester component is a modified polyester having an intrinsic viscosity (IV) of 0.30 to 0.43 and 2.0 to 4.5 mol% of 5-sodium sulfoisophthalic acid copolymerized based on the acid component. The thick and fine composite fiber according to claim 1 or 2.