HK1128312A

HK1128312A - Conjugated fiber containing yarn

Info

Publication number: HK1128312A
Application number: HK09105813.5A
Authority: HK
Inventors: 吉本正人; 安井聪; 森冈茂; 中岛卓
Original assignee: 帝人纤维株式会社
Priority date: 2006-03-01
Filing date: 2007-02-28
Publication date: 2009-10-23

Description

Yarn containing composite fiber

Technical Field

The present invention relates to a conjugate fiber-containing yarn which is curled by heating, has an increased crimp rate due to moisture absorption or water absorption, and is reduced by drying. More specifically, the present invention relates to a conjugate fiber-containing yarn which is heated to develop crimp, and which, even after a dyeing and post-treatment step, has a crimp ratio that increases due to moisture absorption or water absorption and decreases due to drying, and therefore can form a fabric having a higher bulkiness when wet than when dry.

Background

The background art of the present invention is described in the following documents.

[ patent document 1] Japanese examined patent publication No. Sho 45-28728

[ patent document 2] Japanese examined patent publication No. 46-847

[ patent document 3] Japanese patent application laid-open No. Sho 58-46118

[ patent document 4] Japanese patent application laid-open No. Sho 58-46119

[ patent document 5] Japanese patent application laid-open No. S61-19816

[ patent document 6] Japanese patent application laid-open No. 2003-82543

[ patent document 7] Japanese patent application laid-open No. 2003-41444

[ patent document 8] Japanese patent application laid-open No. 2003-41462

[ patent document 9] Japanese patent application laid-open No. 3-213518

[ patent document 10] Japanese patent application laid-open No. S49-72485

[ patent document 11] Japanese patent application laid-open No. Sho 50-116708

[ patent document 12] Japanese patent application laid-open No. 9-316744

It has been known that natural fibers such as cotton, wool, and feather have reversible changes in form and crimp rate due to changes in humidity. In order to provide the above-mentioned functions to the synthetic fibers, studies have been made for a long time, and patent documents 1 and 2 and the like propose side-by-side type conjugate fibers of nylon 6 and modified polyethylene terephthalate. The known conjugate fiber has not been put to practical use because of its small reversible change in crimping rate due to a change in humidity.

Then, patent documents 3 and 4, etc. in which the heat treatment conditions are improved have been proposed. Further, patent documents 5 to 8 and the like to which the above-described conventional techniques are applied have been proposed. However, the actual situation of the prior art is as follows: after the synthetic fiber is dyed or subjected to post-treatment, the change of the crimp rate of the synthetic fiber is reduced and the practical level is not reached.

In contrast, patent document 9 has attempted to improve the above-mentioned problem by using a polyamide having a high moisture absorption rate, such as nylon 4, as a polyamide component, which is obtained by bonding a polyester component and a polyamide component in a flat shape. However, nylon 4 has poor yarn-forming stability and is reduced in crimping performance by heat treatment, and the above-mentioned composite fiber has a limited practical use.

On the other hand, recently, in addition to the above-mentioned stable quality in terms of yarn formability and post-treatment processing, there has been a problem of "strike-through" in the case of producing a fabric in terms of diversification of required characteristics. That is, when a general woven or knitted fabric including synthetic fibers, natural fibers, or the like is used for swimwear, sportswear, or the like, the fabric becomes easily "permeable" when wetted with water or rain, and there is a problem that windproofness and warmth retention properties are reduced. In addition, there is a need for yarns and fabrics that have bulkiness and a silky touch.

On the other hand, a bulky fiber such as a spun yarn has been studied, and for example, patent document 10 discloses a method of obtaining a blended color fiber by interlacing two kinds of yarns spun by a spinning blend and then heating the yarns; patent document 11 discloses a method of spinning and mixing fibers using two kinds of polymers having different dyeability; patent document 12 also discloses a method of obtaining a variegated appearance by utilizing the difference in deep and light dyeing properties by mixing two types of yarns having a difference in orientation through a drawing step. The mixed filament yarns proposed above can surely provide a spun-like woven fabric in terms of mottle and blended color, but cannot provide a wool-like bulkiness. Moreover, the above-mentioned mixed filaments do not have the property that the crimp varies with humidity, unlike wool.

Disclosure of Invention

Problems to be solved by the invention

The present invention was made in view of the above-described conventional techniques, and an object of the present invention is to provide a composite fiber-containing yarn which can form a fabric having "impermeable bottom" characteristics even when wetted with water and having improved wind resistance and heat retention properties by reducing voids in the fabric, and which can stably exhibit the above-described excellent characteristics even after steps such as dyeing and post-treatment.

Means for solving the problems

The yarn containing the composite fiber is characterized in that: comprising a composite fiber yarn obtained by combining a polyester component and a polyamide component into a side-by-side or eccentric sheath-core structure, wherein the composite fiber yarn is heat-treated to be curled so that the crimp rate is increased by moisture absorption or water absorption.

In the composite fiber-containing yarn of the present invention, the composite fiber yarn was subjected to boiling water treatment for 30 minutes to develop crimp, and then the crimp was 1.76X 10^-3The resultant was subjected to a heat treatment at 100 ℃ for 30 minutes under a load of CN/dtex to stabilize the curl, and the resultant was further subjected to a heat treatment at 1.76X 10^-3When the crimped conjugated fiber is subjected to heat treatment at 160 ℃ for 1 minute under a load of CN/dtex, and the dry crimp rate DC after the heat treatment and the wet crimp rate HC after the crimped conjugated fiber having the dry crimp rate DC are immersed in water at 20 to 30 ℃ for 10 hours are measured, the difference Δ C between the wet and dry crimp rates represented by the following formula is preferably 0.3% or more:

ΔC(％)＝HC(％)-DC(％)。

in the yarn containing conjugate fibers of the present invention, the polyester component preferably contains a modified polyester obtained by copolymerizing 2.0 to 4.5 mol% of sodium 5-sulfoisophthalate, based on the total molar amount of the acid component, and has an inherent viscosity IV of 0.30 to 0.43.

In the composite fiber-containing yarn of the present invention, the dry crimp DC is preferably in the range of 0.2 to 6.7%, and the wet crimp HC is preferably in the range of 0.5 to 7.0%.

In the composite fiber-containing yarn of the present invention, the composite fiber yarn may include coarse and fine composite fibers alternately arranged in coarse and fine portions along the length direction thereof.

In the conjugate fiber-containing yarn of the present invention, it is preferable that the dry crimp DC of the thick and thin conjugate fiber yarn is in the range of 4.0 to 12.7%, and the wet crimp HC is in the range of 4.3 to 13.0%.

In the composite fiber-containing yarn of the present invention, it is preferable that the U% of the thick and thin composite fiber yarn is in the range of 2.5 to 15.0%.

In the composite fiber-containing yarn of the present invention, a yarn including one or more types of fibers having a higher shrinkage in boiling water than that of the composite fiber may be combined with the composite fiber-containing yarn, and the composite fiber and the high-shrinkage fiber may be mixed.

In the composite fiber-containing yarn of the present invention, it is preferable that the yarn including the composite fiber in the cabled mixed filament has a boiling water shrinkage ratio (BWSB) of 12 to 30%, the high shrinkage fiber yarn has a boiling water shrinkage ratio (BWSA) of 40% or less, and the difference between the two shrinkage ratios (BWSA) - (BWSB) is 10 to 26%.

The composite fiber-containing yarn of the present invention may be a sheath-core composite false-twisted yarn (1) obtained by false-twisting a composite yarn obtained by using the yarn containing the composite fiber as a sheath yarn and using a different type of filament yarn as a core yarn, wherein a sample having a length of 50cm is collected from the sheath-core composite false-twisted yarn, a load of 0.176cN/dtex (0.2g/de) is applied to one end of the sample and suspended vertically, the sample is marked at 5cm intervals, the load is removed, and the marked portion is cut out to prepare 10 measurement samples. From this sample, 10 sheath portion filaments and core portion filaments were taken, each filament was vertically suspended with a load of 0.03cN/dtex (1/30g/de) applied thereto, and the lengths thereof were measured, and the average values of the measured values of the 10 samples in the core/sheath were respectively La (sheath yarn length) and Lb (core yarn length), and the yarn length difference was calculated by the following formula:

yarn length difference (La-Lb)/La × 100%

In this case, the difference in yarn length (La-Lb)/La (%) is preferably 5 to 20%.

The composite fiber-containing yarn of the present invention may be a false-twisted yarn (2) obtained by false-twisting the composite fiber-containing yarn, and in this case, the crimp rate is increased by moisture absorption or water absorption.

In the composite fiber-containing yarn of the present invention, the false twist textured composite fiber-containing yarn is subjected to boiling water treatment for 30 minutes and then treated at 1.76X 10^-3The mixture was subjected to dry heat treatment at 100 ℃ for 30 minutes under a load of CN/dtex, and then subjected to dry heat treatment at 1.76X 10^-3The dry crimp rate TDC of the composite fiber false-twist yarn after the dry heat treatment at 160 ℃ for 1 minute under the load of CN/dtex is 5.0 to 23.7%. After the composite fiber false-twist yarn is immersed in water at 20 to 30 ℃ for 10 minutes, the wet crimp rate THC is 4.7 to 24%, and the difference between the wet crimp rate THC and the wet crimp rate Δ C, i.e., (THC) - (TDC), is preferably in the range of 0.3 to 8.0%.

Effects of the invention

The composite fiber contained in the composite fiber-containing yarn of the present invention has the following characteristics: curling may occur by heat treatment, and the curling rate increases by moisture absorption or water absorption and decreases by drying. Therefore, a fabric such as a woven or knitted fabric produced using the conjugate fiber-containing yarn of the present invention has high wind resistance and heat retention properties without increasing the see-through property (see-through) due to moisture absorption or water absorption, and the above properties do not change even if subjected to processing such as dyeing or post-treatment. Therefore, the conjugate fiber-containing yarn of the present invention is useful as a raw material for a fiber product such as clothing.

Best Mode for Carrying Out The Invention

The composite fiber contained in the composite fiber-containing yarn of the present invention is characterized in that: a polyester component containing a polyester resin and a polyamide component containing a polyamide resin are combined into a side-by-side structure or an eccentric sheath-core structure, the composite fiber is heat-treated to develop crimp, and the crimp rate of the crimped composite fiber in which crimp is developed is increased by moisture absorption or water absorption.

Examples of the polyester component constituting the composite fiber of the present invention include: polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and the like, among which polyethylene terephthalate is more preferable from the viewpoint of cost and versatility.

In the present invention, the polyester component is preferably a modified polyester obtained by copolymerizing 5-sodium isophthalic acid sulfonate. In this case, when the copolymerization amount of sodium 5-sulfoisophthalate is too large, peeling is less likely to occur at the bonding interface between the polyamide component and the polyester component, but on the other hand, excellent crimping performance cannot be obtained, and it is necessary to promote crystallization for improving the crimping performance, but it is not preferable in terms of yarn production because breakage is likely to occur when the stretching heat treatment temperature is increased for promoting crystallization. On the other hand, if the copolymerization amount is too small, crystallization of the polyester component is easily promoted in the stretching heat treatment to obtain excellent curling properties, but peeling tends to occur easily at the bonding interface between the polyamide component and the polyester component, which is not preferable. Therefore, the copolymerization amount of sodium 5-sulfoisophthalate is preferably 2.0 to 4.5 mol%, more preferably 2.3 to 3.5 mol%.

Further, when the intrinsic viscosity of the polyester component is too low, the yarn formability is lowered and the polyester component is easily napped, which is not preferable in terms of industrial production and quality. On the other hand, even if the intrinsic viscosity is too high, the spinning property and the stretchability of the polyester component side are reduced by the thickening effect caused by the copolymerization of isophthalic acid-5-sulfonic acid sodium salt, and the raising or the breakage is likely to occur. Therefore, the intrinsic viscosity of the polyester component is preferably 0.30 to 0.43, more preferably 0.35 to 0.41.

On the other hand, the polyamide component is not particularly limited as long as it contains an amide bond in the main chain, and examples thereof include: nylon 4, nylon 6, nylon 66, nylon 46, nylon 12, and the like. Among them, nylon 6 and nylon 66 are particularly preferable from the viewpoint of yarn production stability and versatility. In addition, in the above polyamide component, other components may be copolymerized based thereon.

In addition, the two components described above may contain a pigment such as titanium oxide or carbon black, a known antioxidant, antistatic agent, light-resistant agent, 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 and the polyamide component are bonded to each other. The composite form of the polyamide component and the polyester component is preferably a form in which both components are joined in parallel from the viewpoint of occurrence of curling. The cross-sectional shape of the composite fiber may be a circular cross-section or a non-circular cross-section, and for example, a triangular cross-section or a square cross-section may be used as the non-circular cross-section. The composite fiber may have a hollow portion in its cross section.

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

When the composite fiber-containing yarn of the present invention is a yarn composed of composite fibers (100% composite fiber yarn), the yarn composed of composite fibers is subjected to boiling water treatment for 30 minutes to develop crimp, and then the crimp is 1.76 × 10^-3The resultant was subjected to a heat treatment at 100 ℃ for 30 minutes under a load of CN/dtex to stabilize the curl, and the resultant was further subjected to a heat treatment at 1.76X 10^-3When the crimped conjugated fiber is subjected to heat treatment at 160 ℃ for 1 minute under a load of CN/dtex, and then the dry crimp rate DC and the wet crimp rate HC of the crimped conjugated fiber having the dry crimp rate DC after being immersed in water at 20 to 30 ℃ for 10 hours are measured, the wet-dry crimp rate difference Δ C represented by the following formula is preferably 0.3% or more, more preferably in the range of 0.3 to 130%:

ΔC(％)＝HC(％)-DC(％)

the wet-dry crimp difference Δ C is more preferably in the range of 0.3 to 6.8%. In a fabric such as a woven or knitted fabric produced from a yarn including a conjugate fiber having the crimp property, the conjugate fiber contained in the fabric has an increased crimp ratio due to moisture absorption or water absorption, and therefore, even if the fabric is wetted with water, the see-through property (penetration) is not increased, the void portion of the fabric is reduced, and the wind-proof property and the heat retention property are improved. The fabric is not deteriorated in the above properties even after the fabric is subjected to processing steps such as dyeing and post-treatment.

When the conjugate fiber yarn is a drawn yarn (excluding a thick conjugate fiber described later), the dry crimp DC is preferably 0.2 to 6.7%, more preferably 0.2 to 3.0%, even more preferably 0.3 to 2.5%, and even more preferably 0.4 to 2.3%. When the crimp rate DC is less than 0.2%, the yarn obtained is floated, and the hand is deteriorated when the yarn is made into a fabric. On the other hand, if the above-mentioned crimp rate DC exceeds 6.7%, the crimp rate DC is larger than the crimp rate HC after immersion, and there are cases where the object cannot be achieved, that is, the fabric is less likely to be bottomed even when wetted with water, and the mesh size of the fabric is large and the voids are large, so that there are cases where a fabric having excellent wind-proofing properties and warmth retention properties cannot be obtained.

The wet curl rate HC after immersion in water is preferably 0.5 to 7.0%, more preferably 0.8 to 6.5%, and further preferably 1.0 to 6.0%. If the HC is less than 0.5%, the curl rate itself after immersion in water is too low, and the intended anti-strikethrough effect, wind-proofing property, and heat retention property may be insufficient. On the other hand, if the HC value exceeds 7.0%, the fabric shrinks strongly when it contains water, and thus the fabric may be impractical to use and may have a reduced hand.

The difference Δ C between HC and DC is preferably 0.3 to 6.8%, more preferably 0.7 to 5.5%, and still more preferably 0.8 to 5.0%. When Δ C is less than 0.3%, the effect of improving the crimp ratio after immersion in water is small, and a target fabric which is not easily permeable to the bottom after wetting with water and is excellent in water repellency and heat retention may not be obtained. On the other hand, when Δ C exceeds 6.8%, the fabric is strongly shrunk in the presence of water, and thus the fabric may be impractical to use and may have poor hand feeling.

In the composite fiber, the polyester component and the polyamide component may be joined in parallel, and when the two components form an eccentric sheath-core structure, it is preferable that the core portion is composed of the polyester component and the sheath portion is composed of the polyamide component. In general, when the conjugate fiber used in the present invention is subjected to heat treatment to develop crimp, it is preferable that the polyester component is located on the inner side of the bent portion of the crimped conjugate fiber and the polyamide component is located on the outer side. In order to form the above structure, the heat shrinkage rate of the polyester component in the uncrimped conjugate fiber must be greater than that of the polyamide component; in the crimped composite fiber, the water absorption elongation of the polyamide component must be larger than that of the polyester component. In this way, when the crimped conjugated fiber absorbs moisture or water, the polyamide component (outer side of the bend) is stretched longer than the polyester component (inner side of the bend), and the degree of crimping increases.

The crimp ratio is a ratio (%) of a difference between a length of the crimped fiber when the crimp of the crimped fiber is straightened and an apparent length of the crimped fiber to a length of the crimped fiber when the crimp is drawn.

The thermal shrinkage ratio is a ratio (%) of a difference obtained by subtracting a length after heat treatment from a length before heat treatment of a test sample to the length before heat treatment.

The water absorption elongation is a ratio (%) of the difference obtained by subtracting the length before water absorption from the length after water absorption of the test sample to the length before water absorption. When the water absorption elongation is a positive value (+), it means that the water-absorbent fiber is elongated; when the water absorption elongation is a negative value (-), it indicates shrinkage by the water-absorbent fiber.

In order to impart the crimpability to the conjugate fiber of the present invention, both the polyester component and the polyamide component constituting the conjugate fiber are required to have appropriate crystallinity. If the crystallinity is too high, the above-mentioned crimpability, thermal stretchability, and water-absorption elongation may be insufficient; on the other hand, if the crystallinity is too low, the tensile strength is insufficient, and the sheet is likely to be broken in the heat-stretching step, and the stretchability may be insufficient.

The single fiber fineness of the conjugate fiber used in the yarn of the present invention and the total fineness of the yarn containing the conjugate fiber can be appropriately set according to the application, and when the yarn is used for a material for general clothing, for example, the single fiber fineness of the conjugate fiber is preferably 1 to 6dtex, and the total fineness of the yarn containing the conjugate fiber is preferably 40 to 200 dtex.

The yarn containing the composite fiber of the present invention may be subjected to an interlacing process to interlace the constituent fibers thereof.

In the production of the conjugate fiber for yarn of the present invention, for example, as described in japanese patent application laid-open No. 2000-144518, a spinneret is used in which a high-viscosity component side and a low-viscosity side discharge hole are separated from each other, and the linear velocity of discharge at the high-viscosity side is reduced (the discharge cross-sectional area is increased), and the polymer melt streams discharged from the high-viscosity component discharge hole and the low-viscosity component discharge hole are joined in a parallel or eccentric sheath-core manner or combined by passing the molten polyester through the high-viscosity side discharge hole and the molten polyamide through the low-viscosity side discharge hole, and the conjugate stream of the polymer melt thus formed is cooled and solidified.

The undrawn composite fiber obtained from the melt spinning apparatus may be once wound, then rewound, drawn and supplied to a heat treatment as needed, or may be supplied to the drawing step without being wound, and at the same time, or thereafter, supplied to the heat treatment step.

In the production of the conjugate fiber for yarn of the present invention, the melt spinning speed is preferably 800 to 3500 m/min, more preferably 1000 to 2500 m/min. In the drawing of the undrawn fiber, the undrawn conjugate fiber formed by the melt spinning apparatus is directly drawn (without winding) using a drawing machine that performs drawing between two rolls, and if necessary, heat treatment may be performed simultaneously with drawing. For example, in the supply side 1 roller of the drawing machine, the supplied undrawn conjugate fiber is preheated to a temperature of 50 to 100 ℃, and the preheated conjugate fiber is drawn between the 1 st roller and the 2 nd roller for delivery, and the heat treatment can be performed in the 2 nd roller heated to a temperature of 80 to 170 ℃, preferably 80 to 140 ℃. The draw ratio between the first and 2 nd rolls may be set so as to impart the desired heat crimp expression to the resulting conjugate fiber, and is, for example, preferably 1.2 to 3.0, more preferably 1.5 to 2.9.

In order to impart crimp to the composite fiber for yarn of the present invention, the composite fiber (uncrimped) is heated to impart crimp. For example, when uncrimped conjugate fibers are treated in boiling water for, for example, 30 minutes to cause crimp to occur, the polyester component is located on the inside of the bent portion of the resultant crimped fiber, and the polyamide component is located on the outside. In the crimped fiber, the polyamide component absorbs water, and the polyamide component is elongated with time by the plasticizing effect of the water, so that the crimped state of the crimped fiber changes with time and is unstable. Therefore, the crimped fibers are subjected to dry heat treatment to remove moisture, thereby stabilizing the crimped state of the crimped conjugated fibers. When it is dried, it is preferable to dry-heat it at 100 ℃ for 30 minutes and dry-heat it at 160 ℃ for 1 minute, for example.

The crimp developed in the conjugate fiber was stabilized by the boiling water treatment (30 minutes), the dry heat treatment (30 minutes at 100 ℃) and the post-treatment drying (1 minute at 160 ℃) as described above, and thereafter, the crimp characteristics of the crimp-stabilized conjugate fiber were not significantly changed even if the ordinary heat treatment was applied thereto.

The composite fiber-containing yarn of the present invention may be composed of only the composite fiber, or the composite fiber yarn may be combined with a different fiber yarn to blend the two fibers. The composite fiber-containing yarn of the present invention may be a composite fiber-containing false twist yarn obtained by applying false twist processing as needed. Alternatively, the composite fiber-containing yarn of the present invention may be a composite fiber-containing false twist yarn obtained by subjecting a yarn composed of the composite fiber alone and a yarn including the composite fiber and a fiber (which may be a composite fiber) different from the fiber in terms of the cut elongation to false twisting.

The composite fiber-containing yarn of the present invention can be used for various clothing applications. For example, when used for a swimwear, other sportswear, interlining, or uniform, which is a moisture-absorbing or water-absorbing application, the fabric exhibits a see-through (strike-through) effect in preventing wet wearing, and is excellent in wind-proofing and heat-retaining properties, and therefore exhibits high comfort when worn.

The composite fiber-containing yarn of the present invention may be used together with a natural fiber yarn, or may be used in combination with a polyurethane fiber yarn or a polytrimethylene terephthalate fiber yarn for an elastic yarn or a fabric.

The composite fiber-containing yarn of the present invention, as one embodiment thereof, comprises a yarn containing thick and thin composite fibers alternately distributed in thick and thin portions along the length direction thereof.

When a yarn containing crimped coarse-fine conjugate fibers obtained by heat-treating the coarse-fine conjugate fibers is used to produce a fabric such as a woven fabric, the yarn fabric containing the crimped coarse-fine conjugate fibers promotes an increase in the crimp ratio due to moisture absorption and water absorption, and can prevent an increase in the see-through property (bottom penetration) of the wet fabric, when the yarn fabric is wetted with water, particularly when the coarse-fine conjugate fibers have thick portions and thin portions alternately distributed.

That is, in the yarn including the thick and thin conjugate fibers, the dry crimp DC is preferably 4.0 to 12.7%, more preferably 4.0 to 12.0%, even more preferably 4.5 to 10.0%, and even more preferably 5.0 to 8.5%. If the percentage of crimp DC is less than 4.0%, the hand tends to be poor when the fabric is produced, whereas if the percentage of crimp DC exceeds 12.7%, the percentage of crimp DC tends to be larger than the percentage of crimp HC after immersion in water, and the bottom penetration resistance is reduced, the fabric voids are reduced, and the wind-proofing and heat-insulating properties may be insufficient.

The wet curl rate HC after immersion in water is preferably 4.3 to 13.0%, more preferably 5.0 to 13.0%, even more preferably 5.5 to 11.0%, and even more preferably 6.0 to 10.5%. When the percentage of curl HC is less than 4.3%, the percentage of curl after immersion is too low, and the target anti-strike effect or the effect of improving the windproof property and the warmth retention property may be insufficient; on the other hand, if the value of the crimping rate HC exceeds 13.0%, the fabric may shrink significantly when it contains water, which makes it impractical to use and may deteriorate the hand.

The difference Δ C between HC and DC is preferably 0.3 to 8.0%, more preferably 1.0 to 5.5%, and still more preferably 1.5 to 4.5%. When Δ C is less than 0.3%, the effect of improving the crimp ratio after immersion in water is small, the bottom penetration is not easily caused when wetted with water, and the fabric has less voids, and thus a fabric having improved windproofness and warmth retention properties may not be obtained. On the other hand, when Δ C exceeds 8.0%, the fabric shrinks significantly when it contains water, and thus the fabric is not practical and the hand may be degraded.

The yarn containing the thick and thin conjugate fiber of the present invention is not only excellent in functionality but also excellent in touch. That is, since the conjugate fiber of the present invention has thick and thin portions in the longitudinal direction, when a yarn including the conjugate fiber is made into a fabric, the fabric has a hand feeling similar to a spun yarn. In the present invention, the U% representing the thickness of the conjugate fiber is preferably 2.5 to 15.0%, more preferably 3.5 to 14.5%, and still more preferably 4.0 to 13.5%. If the U% is less than 2.5%, the hand feeling of the spun-like yarn cannot be obtained when the fabric is produced, which is not preferable, and the penetration preventing property at the time of moisture absorption tends to be lowered. On the other hand, if the U% exceeds 15.0%, the strength of the composite fiber is lowered, and handling thereof becomes difficult, which is not preferable.

U% is a parameter indicating the thickness of the yarn, and is calculated from a yarn evenness curve of a sample having a length L measured by a yarn evenness tester (useter) by the formula U% ═ F/F × 100. [ wherein F represents the area calculated from the average thickness and length of the yarn, and F represents the total area between the yarn uniformity curve and the straight line showing the average thickness ]

When the thick and thin composite fiber yarn of the present invention is used as a material for general clothing, the yarn may have a total fineness of 40 to 200dtex and a single-filament fineness of 1 to 6 dtex. It is to be noted that interleaving may be performed as necessary.

In the production of the thick and thin conjugate fiber yarn of the present invention, for example, as described in japanese patent application laid-open No. 2000-144518, the thick and thin conjugate fiber yarn is obtained by passing the molten polyester through the high-viscosity side discharge holes and joining the molten polyamide through the low-viscosity side discharge holes by using a spinneret which separates the high-viscosity component side from the low-viscosity side discharge holes and reduces the linear discharge speed (increases the discharge cross-sectional area) of the high-viscosity side, and then cooling and solidifying the molten polyester. The drawn spun yarn may be drawn after being wound once, and may be subjected to drawing by heat treatment as required; and a method of drawing without winding and optionally heat-treating the drawn material. The spinning speed is preferably 800-3500 m/min.

For example, when the drawing and heat setting are carried out by the straight drawing using a drawing machine provided with two rolls, it is preferable to preheat the yarn at a temperature of 60 ℃ or lower in the 1 st roll. When the preheating temperature exceeds 60 ℃, the target thickness may not be obtained, which is not preferable. Then, the heat-setting may be carried out by using the 2 nd roll at a temperature of preferably 80 to 170 ℃ and more preferably 80 to 140 ℃. The ratio of the stretching performed between the 1 st roll and the 2 nd roll can be set in consideration of the thickness. For example, the thick and thin conjugate fiber yarn of the present invention can be easily obtained by setting the elongation at break of the undrawn conjugate fiber yarn to at least 55% under the condition of low-ratio drawing.

In order to impart crimp to the thick and thin conjugate fiber yarn of the present invention, it is first treated with boiling water. Thereby obtaining a curl with the polyester component disposed inside. Since this state is only a water-containing state, the polyamide elongates due to the plasticizing effect of water, and therefore the curl itself changes with time and is not stable. Therefore, the yarn curled by boiling water is subjected to dry heat treatment to remove moisture, thereby stabilizing the curl. In order to stabilize the crimp characteristics, for example, as described above, the composite fiber is subjected to boiling water treatment for 30 minutes, then to dry heat treatment at 100 ℃ for 30 minutes to develop crimp, and then to dry heat treatment at 160 ℃ for 1 minute. The yarn fabric containing the coarse-fine conjugate fiber, which is stabilized in the crimp by the above-described operation, can be obtained with desired properties even if it is subjected to a heat treatment in a usual post-treatment step.

The thick and thin conjugate fiber of the present invention can be used alone, or can be mixed with other fibers to be used as a mixed filament. If necessary, the yarn may be further false-twisted and used as a false-twisted yarn. It can also be used as a composite false twist with different elongations.

The thick and thin composite fiber yarn of the present invention can be used for various purposes for clothing. For example, it is particularly preferably used for applications requiring comfort, such as waterproof clothing, various sports wear, lining materials, and uniforms.

Of course, the effect of the present composite fiber can be further exhibited by compounding the natural fiber with the coarse and fine composite fiber. It is also possible to use the yarn after further imparting elasticity by combining it with a polyurethane or polytrimethylene terephthalate yarn.

The composite fiber-containing yarn of the present invention, as one embodiment thereof, comprises a composite fiber-containing hybrid filament formed by: that is, the yarn is formed by doubling a yarn containing one or more types of fibers having a higher shrinkage in boiling water than the composite fiber in boiling water, and mixing the composite fiber with the high-shrinkage fiber.

The composite fiber-containing hybrid filament of the above aspect has the characteristic of being "impermeable to the bottom" even when wetted with water, and exhibits excellent wind resistance and heat retention properties in this case. That is, the mixed filament has a bulky texture, a real silk texture, and an excellent texture, and also exhibits effects of new functionality not possessed by the conventional monofilaments and mixed filaments.

In the present invention, in order to obtain a bulky feeling, the high-shrinkage fiber is desirably high in the shrinkage ratio (BWSA) in boiling water, but is preferably 40% or less.

This is because the hand of the resulting woven fabric tends to be hard when the shrinkage ratio (BWSA) exceeds 40%. The shrinkage ratio (BWSB) of the conjugate fiber in boiling water is preferably 12 to 30%, more preferably 13 to 28%, and still more preferably 14 to 26%. If the shrinkage ratio (BWSB) of the conjugate fiber in boiling water is less than 12%, the heat treatment temperature for reducing the shrinkage ratio must be increased, and the breakage line increases in the production of the conjugate filament, which is not preferable. On the other hand, if the shrinkage ratio (BWSB) of the conjugate fiber in boiling water exceeds 30%, the hand is liable to be rough, which is not preferable.

The difference (BWSA-BWSB) between the shrinkage ratio (BWSA) of the high shrinkage fiber and the shrinkage ratio (BWSB) of the conjugate fiber is preferably 10 to 26%, more preferably 12 to 24%, and still more preferably 14 to 22%. When Δ BWS is less than 10%, a bulky woven or knitted fabric tends to be difficult to obtain; on the other hand, when Δ BWS exceeds 26%, it is difficult to obtain a fabric having a real silk feel. In addition, since the shrinkage of the conjugate fiber is reduced in the production thereof, the composite fiber is likely to be broken during the production.

In the hybrid filament of the present invention, the conjugate fiber is a filament whose crimp rate increases by moisture absorption or water absorption. The inventors of the present invention found that: the hybrid filament comprising the above-mentioned structure does not "strike through" even when the fabric is wetted with water, and in this case, the fabric is clogged with meshes, and is excellent in wind resistance and heat retention. Has a bulky feeling even when wetted with water.

In the composite fiber-containing mixed filament of the present invention, the composite fiber yarn used in the process is treated in boiling water for 30 minutes to disperse the crimp, then dry-heat treated at 100 ℃ for 30 minutes to stabilize the crimp, and then dry-heat treated at 160 ℃ for 1 minute, and the difference (HC) - (DC) (. DELTA.c) between the dry crimp rate DC at that time and the wet crimp rate HC after immersing the dry-heat crimped fiber in water at 20 to 30 ℃ is preferably 0.5 to 5.0%, and more preferably 0.8 to 6.0%. When Δ C is less than 0.5%, the effect of increasing the curling rate by moisture absorption or water absorption (penetration prevention, improvement of windproof warmth retention) is insufficient; when Δ C exceeds 5.0%, the shrinkage of the mixed filament or fabric due to moisture absorption or water absorption becomes too high, and the hand may be impaired.

As a method for producing the hybrid filament, the following method can be employed: a method of producing a high-shrinkage fiber yarn and a composite fiber yarn separately, doubling the obtained high-shrinkage fiber yarn and composite fiber yarn, supplying the resultant yarn to a fiber interlacing processor such as an air interlacing machine (interlacing machine), and mixing the resultant yarn by injecting air thereto.

The high shrinkage fiber yarn comprises: a high-shrinkage fiber containing a single polyester polymer, a high-shrinkage conjugate fiber (a fiber having the same conjugate composition as that of the conjugate fiber used as the low-shrinkage component), a high-shrinkage conjugate fiber containing polyethylene terephthalate and polypropylene terephthalate, a high-shrinkage conjugate fiber containing polyethylene terephthalate and polybutylene terephthalate, and the like. Examples of such single polyester polymer fibers are: high-shrinkage fibers such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and the like. Among them, polyethylene terephthalate fibers are preferably used from the viewpoint of cost.

When the mixed filament is used as a material for ordinary clothing, the total fineness is preferably 40 to 200dtex, and the single-fiber fineness of each of the high-shrinkage fiber and the composite fiber is preferably 1 to 6 dtex.

The mixed filament can be used alone, and can also be mixed with other fibers or compounded for use. The other fibers may be natural fibers, or polyurethane fibers and polytrimethylene terephthalate fibers may be combined to further impart elasticity for reuse.

The composite false-twist yarn of the present invention can be used for various applications for clothing, and is particularly preferably used for applications requiring comfort such as air impermeability, wind resistance, and heat retention, for example, various sportswear, interlining material, and uniform.

The composite fiber-containing yarn of the present invention includes, as one embodiment thereof, a sheath-core composite false-twisted yarn obtained by false twisting a composite yarn obtained by using the composite fiber-containing yarn as a sheath yarn and using a filament yarn different from the sheath yarn as a core yarn. A sample of 50cm in length was collected from this sheath-core composite false-twisted yarn, a load of 0.176cN/dtex (0.2g/de) was applied to one end of the sample and suspended vertically, the sample was marked at 5cm intervals, the above load was removed, the marked portion was cut out to prepare 10 measurement samples, 10 single fibers (filaments) of the sheath portion and fibers (filaments) of the core portion were each collected from the sample, a load of 0.03cN/dtex (1/30g/de) was applied to each single fiber and suspended vertically, the respective lengths were measured, and the average values of the measurement values of 10 samples in the core/sheath were defined as La (sheath yarn length) and Lb (core yarn length), and the yarn length difference was calculated by the following formula:

yarn length difference (La-Lb)/La × 100%

The yarn length difference (La-Lb)/La (%) is preferably 5 to 20%.

The sheath-core composite false-twisted yarn containing the composite fiber has a characteristic of being "impermeable" even when wetted with water, and exhibits wind-proofing and heat-retaining properties in this case. That is, the composite false-twisted yarn has a bulky texture like a spun yarn, is soft, and is excellent in hand feeling, and also exerts an effect of a new function which has not been possessed by the conventional composite false-twisted yarn.

The sheath-core composite false-twist yarn containing the composite fiber is composed of a sheath yarn and a core yarn, and thus has a bulky feeling in the wool spun yarn style and can exhibit a soft hand feeling.

The fibers making up the sheath and the fibers making up the core preferably differ in average yarn length. That is, the average yarn length of the fibers constituting the cover yarn is preferably 5 to 20% longer than the average yarn length of the fibers constituting the core yarn, and more preferably 8 to 15% longer. In this case, in the composite false twist processing, the fibers constituting the sheath yarn are mainly disposed in the sheath portion of the composite false twist processed yarn, and the fibers constituting the core yarn are mainly disposed in the core portion. Whereby a slimmer hand can be exhibited. In addition, the workability in the knitting step is improved, and a softer hand is obtained. If the difference in yarn length between the fibers constituting the cover yarn and the fibers constituting the core yarn is less than 5%, the resulting fabric will not have a hand feeling similar to that of a spun yarn. When the yarn length difference exceeds 20%, the resultant fabric tends to have a soft texture, and yarn breakage often occurs during false twisting, which is not preferable.

In the composite false twist yarn, it is important to include a composite fiber in which the crimp rate is increased by moisture absorption or water absorption of the sheath yarn. The inventors of the present invention found that: the composite false-twisted yarn comprising the above-described structure does not "strike through" even when wetted with water, and at this time, the fabric is clogged with meshes, and is excellent in wind resistance and heat retention. Has a bulky feeling even when wetted with water.

The conjugate fiber used for the sheath yarn of the composite false twist yarn, the crimp rate of which is increased by moisture absorption or water absorption, is a side-by-side or eccentric sheath-core conjugate fiber having a fiber cross-sectional shape in which a polyester component and a polyamide component are bonded to each other.

In the sheath-core composite false-twisted yarn containing the composite fiber, in order to obtain characteristics that the hand feeling and the crimp rate of the spun-like yarn increase due to water absorption and moisture absorption, the elongation at break of the sheath yarn is preferably 60 to 350%, and more preferably 100 to 300%. When the elongation at break of the covered yarn exceeds 350%, the difference in yarn length between the covered yarn and the core yarn tends to exceed 20%, the hand feeling is not good, and the yarn breakage often occurs during the composite false twisting. On the other hand, when the elongation at break of the covered yarn is less than 60%, the difference in yarn length between the covered yarn and the core yarn tends to be less than 5%, making it difficult to obtain a desired texture, and the increase in the crimp rate due to moisture absorption is also reduced.

The composite fiber for the sheath-core composite false-twisted yarn containing the composite fiber can be produced by the above method, but it is preferable that the composite fiber is wound at a high speed without applying a drawing heat treatment after the step of melting the yarn, and preferable results are obtained when the spinning speed is 1000 to 4500 m/min. When the spinning speed is less than 1000 m/min, the elongation at break of the resulting composite fiber sometimes becomes too large; when the spinning speed exceeds 4500 m/min, yarn breakage frequently occurs in the yarn making process.

In the sheath-core composite false-twist yarn containing the composite fiber, for example, a composite fiber containing a polyester alone, a composite fiber having the same composition as that of the sheath yarn, a composite fiber containing polyethylene terephthalate and polypropylene terephthalate, or the like can be used as the core yarn. Among them, a single component of polyester is preferable from the viewpoint of cost. In this case, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and the like can be used as the polyester, but polyethylene terephthalate is more preferable from the viewpoint of cost.

When the composite false-twist processed yarn is used as a material for ordinary clothing, the processed yarn can be used, wherein the total fineness of the processed yarn is 40 to 200dtex, and the single-yarn fineness of the core yarn and the sheath yarn is 1 to 6 dtex.

As a method for producing the composite false-twisted yarn, it is possible to combine the core yarn and the sheath yarn described above, preferably to air-interlace them, and to perform composite false-twist processing using a known false-twist processing machine. In this case, a disc type or belt type false twisting device may be used as the false twisting device.

The composite false twist textured yarn can be used alone, or can be mixed or compounded with other fibers.

Of course, the effect of the composite false-twist yarn can be further exerted by the composite with the natural fiber, and the composite can be used after further imparting elasticity by combining with polyurethane or polytrimethylene terephthalate.

The composite false-twist yarn can be used for various purposes for clothing, and is particularly preferably used for various sports wear, interlining material, uniform and the like which require comfort such as air-proof property, wind-proof property, heat retention property and the like.

The composite fiber-containing yarn of the present invention includes, as one embodiment thereof, a composite fiber-containing false twist processed yarn obtained by false twist processing and having a crimp rate increased by moisture absorption or water absorption.

The false twist yarn containing the composite fiber was subjected to boiling water treatment for 30 minutes, and then the boiling water treatment was carried out at a temperature of 1.76X 10^-3The mixture was subjected to dry heat treatment at 100 ℃ for 30 minutes under a load of CN/dtex, and then subjected to dry heat treatment at 1.76X 10^-3After dry heat treatment at 160 ℃ for 1 minute under a load of CN/dtex, the dry crimp rate TDC of the composite fiber false-twisted yarn is 5.0 to 23.7%, and the wet crimp rate THC of the composite fiber false-twisted yarn after immersion in water at 20 to 30 ℃ for 10 minutes is 5.3 to 24%, and the crimp rate Δ C represented by the difference (THC) - (TDC) between the dry crimp rate and the wet crimp rate is preferably in the range of 0.3 to 8.0%.

The composite fiber-containing false-twisted yarn has the characteristic of being "impermeable" even when wetted with water, is excellent in wind resistance and heat retention, and is a yarn obtained by imparting a functional effect, which has not been achieved so far, to a false-twisted yarn having only a hand effect such as bulkiness or elasticity.

In the false twist yarn containing the composite fiber, it is important that the crimp ratio is increased by moisture absorption or water absorption. The inventors of the present invention found that: the false twist yarn having the above crimp characteristics does not "strike through" even when wetted with water, and at this time, the fabric is clogged with the meshes, and is excellent in wind resistance and heat retention.

According to the study of the present inventors, it is found that: by selecting the polymer composition of the composite fiber, particularly the polyester component, the composite fiber containing the polyester component and the polyamide component can be obtained, and the spinnability and the false twist processability of the yarn containing only the polyamide component can be obtained. That is, when the polyester component is a modified polyester obtained by copolymerizing isophthalic acid-5-sodium sulfonate, the modified polyester preferably has an appropriate inherent viscosity. Specifically, the viscosity of the polyester component increases due to the molecular crosslinking effect of sodium 5-sulfoisophthalate, and this component determines the spinnability and the false twist processability, but by greatly reducing the intrinsic viscosity of the polyester component, the spinnability and the false twist processability similar to those of a yarn containing only the polyamide component can be obtained, and the false twist processed yarn of the present invention having an increased crimp rate due to moisture absorption or water absorption can be easily obtained. However, when the intrinsic viscosity of the polyester component is too low, the yarn formability is reduced and the yarn is easily raised, which is not preferable in terms of industrial production and quality. Therefore, as described above, the intrinsic viscosity is preferably 0.30 to 0.43, more preferably 0.35 to 0.41.

In addition, in the modified polyester, when the benzene two formic acid-5-sodium sulfonate copolymerization amount is too small, although excellent crimp characteristics are obtained, but in the polyamide component and polyester component joint interface easy to peel, therefore not preferred. On the other hand, if the copolymerization amount of sodium 5-sulfoisophthalate is too large, crystallization of the polyester is difficult to be promoted in the drawing heat treatment and false twisting step, so that it is difficult to obtain a false-twisted yarn having a high crimp ratio, and yarn breakage is often caused when the drawing heat treatment temperature and the false twisting temperature are raised to promote crystallization, which is not preferable. Therefore, as described above, the copolymerization amount of the sodium 5-sulfoisophthalate is preferably 2.0 to 4.5 mol%, more preferably 2.3 to 3.5 mol%.

In the above-described two components, a pigment such as titanium oxide or carbon black, a known antioxidant, antistatic agent, light-resistant agent, and the like may be contained.

In the composite form of the polyamide component and the polyester component in the composite fiber, the two components are preferably joined in a side-by-side form in view of occurrence of crimp. The cross-sectional shape of the composite fiber may be a circular cross-section or a non-circular cross-section, and for example, a triangular cross-section or a square cross-section may be used as the non-circular cross-section. The composite fiber may have a hollow portion in its cross section.

In the false-twisted yarn containing the composite fiber, the false-twisted yarn is subjected to boiling water treatment for 30 minutes as described above, then dried heat-treated at 100 ℃ for 30 minutes to develop crimp, and then dried heat-treated at 160 ℃ for 1 minute, and it is preferable that the following requirements are satisfied at the same time as the following crimping rate DC, the crimping rate HC after immersion, and the difference Δ C between the crimping rates.

That is, the crimping rate TDC is preferably 5.0 to 23.7%, more preferably 5.0 to 23%, further preferably 6.0 to 20%, and further preferably 7.0 to 15%. When the above-mentioned crimp TDC is less than 5.0%, a fabric having excellent bulkiness cannot be obtained, which is not preferable. On the other hand, when the above-mentioned crimp TDC exceeds 23.7%, peeling is liable to occur at the interface between the polyester component and the polyamide component in the false twisting for imparting the above-mentioned high crimp, which is not preferable.

The percentage of crimp THC after immersion in water is preferably 5.3 to 24%, more preferably 7.0 to 24%, even more preferably 8.0 to 20%, and even more preferably 9.0 to 18%. If the percentage of crimp THC is less than 5.3%, the bottom penetration preventing effect, wind resistance, and heat retention tend to be insufficient, which is not preferable. On the other hand, when the crimping rate THC exceeds 24%, the fabric shrinks significantly when it contains water, which is not practical, and the hand is also reduced, which is not preferable.

The difference Δ TC between the THC and the TDC is preferably 0.3 to 8.0%, more preferably 0.5 to 7.0%, even more preferably 0.8 to 6.0%, and even more preferably 1.0 to 5.5%. When Δ TC is less than 0.3%, the effect of increasing the crimp ratio after immersion in water is small, and it is difficult to obtain a fabric which is not easily penetrated by water and is excellent in wind-proofing properties and heat-retention properties. On the other hand, when Δ TC exceeds 8.0%, the fabric shrinks significantly when it contains water, and the hand is also reduced, which is not preferable.

When the false twist yarn containing the composite fiber is used as a material for ordinary clothing, the yarn can be used in which the total fineness is 40 to 200dtex and the single-fiber fineness is 1 to 6 dtex. The interleaving process may be performed as necessary.

The composite fiber can be produced by the above method, but the spinning speed is preferably as high as 2000 to 4000 m/min. In this way, a composite fiber yarn which can be easily false twisted can be obtained. For the false twisting, a conventional false twisting device may be used, and among them, a conventional false twisting device, that is, a disk type or belt type false twisting device may be used.

The false twist yarn containing the composite fiber can be used alone, and can also be used together with other fibers or mixed fibers. That is, the false twist yarn containing the conjugate fiber may be used in combination with a natural fiber yarn, or the false twist yarn containing the conjugate fiber may be used in combination with a polyurethane yarn or a polytrimethylene terephthalate fiber to form a yarn or a fabric having elasticity.

The false twist yarn containing the composite fiber can be used for various clothing applications, for example, for sportswear, interlining material, uniform, etc., and can effectively exhibit moisture resistance, wind resistance, warmth retention, wet see-through resistance, etc.

Examples

The invention is further illustrated by the following examples.

In the following examples and comparative examples, the following measurements were carried out.

(1) Intrinsic viscosity of polyamides and polyesters

When the intrinsic viscosity of the polyamide was measured, m-cresol was used as a solvent, and the measurement was carried out at 30 ℃. When the intrinsic viscosity of the polyester was measured, o-chlorophenol was used as a solvent, and the measurement was carried out at 35 ℃.

(2) Property of making silk

3: the yarn is broken for 0 to 1 time in 10-hour continuous spinning, and the yarn-making property is good.

2: the yarn is broken for 2-4 times in 10-hour continuous spinning, and the yarn-making property is poor.

1: the yarn was broken 5 times or more after 10 hours of continuous spinning, and the yarn-forming property was extremely poor.

(3) Interfacial peeling resistance between polyamide component and polyester component

The cross section of 24 composite fibers arbitrarily collected was photographed 1070 times in color, and the interfacial separation state between the polyamide component and the polyester component in the filaments was examined.

3: almost (0 to 1) no peeling at the interface.

2: the filaments have 2 to 10 interfacial separations.

1: there was interfacial delamination on almost all filaments.

(4) Tensile Strength (cN/dtex), elongation at Break (%)

The fiber sample was left for a day and night in a room kept at a constant temperature and humidity at an air temperature of 25 ℃ and a humidity of 60%, and then the sample was fixed to a tensile tester Tensilon made by Shimadzu corporation for a length of 100mm, and was pulled at a speed of 200 mm/min to measure the strength and elongation at break.

(5) 10% elongation stress (cN/dtex)

The stress at 10% elongation was determined from the stress-elongation curve obtained by measuring the strength and elongation, and the value was determined by dividing the value by the fineness of the conjugate fiber.

(6) Dry curl rate DC, wet curl rate HC after immersion in water, and difference Δ C between them ((HC) - (DC))

A skein of 2700dtex was made from the conjugate fiber and treated in boiling water for 30 minutes under a light load of 6g (2.2 mg/dtex). After removing the water gently with filter paper, the sheet was dried under a load of 6g (2.2mg/dtex) with dry heat at 100 ℃ for 30 minutes to remove the water. The skein was further subjected to a dry heat treatment at 160 ℃ for 1 minute under a load of 6g (2.2mg/dtex) to prepare a measurement sample.

(a) Dry curl Rate DC (%)

The measurement sample (skein) subjected to the above-mentioned treatment was treated under a load of 6g (2.2mg/dtex) for 5 minutes, and then the skein was taken out, and a load of 600g (total of 606 g: 2.2mg/dtex +220mg/dtex) was applied thereto, and the skein was left to stand for 1 minute, to obtain the length L0 of the skein. Then, the load of 600g was removed, and the sheet was left under a load of 6g (2.2mg/dtex) for 1 minute to determine the length L1. The curl rate DC is obtained from the following calculation formula.

DC(％)＝L0-L1/L0×100

(b) Wet curl after immersion HC (%)

The same skein after the determination of the crimp DC was used and treated in water (room temperature) for 10 minutes under a load of 6g (2.2 mg/dtex). The skein was wiped off with filter paper, and then a load of 600g (606 g in total: 2.2mg/dtex +220mg/dtex) was applied thereto, and the skein was left for 1 minute to determine the length L2 of the skein. Then, the load of 600g was removed, and the sheet was left under a load of 6g (2.2mg/dtex) for 1 minute to determine the length L3. The percentage of curling HC after immersion was obtained from the following calculation formula.

HC(％)＝L2-L3/L2×100

(c)ΔC(％)

The difference Δ C between the above-mentioned crimping rate DC and the crimping rate HC after immersion is obtained by the following equation.

ΔC(％)＝HC(％)-DC(％)

(7) Characteristics of knitting cylindrical gray fabrics

The conjugate fiber was woven into a cylindrical gray fabric, boiled and dyed with a cationic dye, washed with water, and set in dry heat at 160 ℃ for 1 minute to obtain a measurement sample. Water was dropped onto the knitted cylindrical fabric, and the state of the portion where water was dropped and the periphery thereof were examined by a side photograph (magnification 200) of the knitted cylindrical fabric, and the state of expansion or contraction of the stitches due to the water dropping and the bottom-penetrating feeling of the knitted cylindrical fabric were visually judged.

(a) Degree of contraction of coil (degree of void reduction)

3: the coil shrinks significantly (void reduction) due to the dripping.

2: little coil change due to dripping was found (little change in air gap).

1: since the drip coil is rather elongated (the gap becomes large).

(b) Bottom penetration prevention (non-transparent feeling)

3: the "strikethrough" of the dripping portion was reduced (the feeling of opacity was increased).

2: no change in "strikethrough" caused by dripping (no change in opacity) was observed.

1: the "strike through" due to the dripping water becomes larger (less opaque feeling).

[ example 1]

Nylon 6 having an inherent viscosity [ eta ] of 1.3 and modified polyethylene terephthalate having an inherent viscosity [ eta ] of 0.39 and copolymerized with 3.0 mol% of sodium 5-sulfoisophthalate were melted at 270 ℃ and 290 ℃ respectively, extruded at an output of 11.7 g/min using a composite spinneret as described in Japanese patent application laid-open No. 2000-144518 to form side-by-side composite yarns, cooled and solidified to give an oil solution, and then the yarns were preheated at 1000 m/min by a 1 st roll at a temperature of 60 ℃ and subjected to a drawing heat treatment at 2800 m/min between a 2 nd roll heated to a temperature of 130 ℃ (at a draw ratio of 2.80 times) to obtain 83dtex 24fil composite fibers. The silk-making property is excellent, the continuous spinning time is 10 hours, and the yarn is not broken at all. The results are shown in Table 1.

In the composite spinneret described in the above-mentioned Japanese patent application laid-open No. 2000-144518, the spinning hole is substantially composed of two arc-shaped slits A and B arranged at an interval (d) on the same circumference, and the area SA and the slit width A of the arc-shaped slit A₁Area SB of arc-shaped slit B and slit width B₁And a spinning nozzle hole having an area SC surrounded by the inner peripheral surfaces of the circular-arc slits A and B and satisfying the following formulas (I) to (IV).

①B₁<A₁

②1.1≦SA/SB≦1.8

③0.4≦(SA+SB)/SC≦10.0

④d/A₁≦3.0

The polyethylene terephthalate was extruded from the slit A side, and the nylon 6 was extruded from the slit B side.

Examples 2 to 3 and comparative example 1

In example 1, a conjugate fiber yarn was obtained in the same manner as in example 1 except that the temperature of the 2 nd roll was changed as shown in table 1. The results are shown in Table 1.

Examples 4 to 6 and comparative examples 2 to 3

In example 1, a conjugate fiber yarn was obtained in the same manner as in example 1 except that the roll speed of the 2 nd roll was changed as shown in table 1. The results are shown in Table 1.

Examples 7 to 8 and comparative example 4

Examples 9 to 10 and comparative examples 5 to 6

In example 1, a conjugate fiber yarn was obtained in the same manner as in example 1 except that the copolymerization amount of sodium isophthalate-5-sulfonate of modified polyethylene terephthalate was changed as shown in table 1. The results are shown in Table 1.

Examples 11 to 12 and comparative examples 7 to 8

A conjugate fiber yarn was obtained in the same manner as in example 1, except that the intrinsic viscosity η of the modified polyethylene terephthalate in example 1 was changed as shown in table 1. The results are shown in Table 1.

[ example 13]

Nylon 6 having an inherent viscosity [ eta ] of 1.3 and modified polyethylene terephthalate having an inherent viscosity [ eta ] of 0.39 and copolymerized with 3.0 mol% of sodium 5-sulfoisophthalate were melted at 270 ℃ and 290 ℃ respectively, extruded at an output of 16.9 g/min using a composite spinneret as described in Japanese patent application laid-open No. 2000-144518 to form side-by-side composite yarns, cooled and solidified to give an oil, and then the yarns were preheated at 1800 m/min by a 1 st roll at RT (room temperature), followed by a drawing heat treatment (drawing ratio of 1.69 times) at a speed of 3050 m/min between a 2 nd roll heated to 130 ℃ and wound to obtain 110 dtex 24fil thick and thin composite fibers. The yarn-making property and the tensile property are excellent, the continuous spinning is carried out for 10 hours, and the yarn breakage is completely avoided. The results are shown in Table 2.

Examples 14 to 17 and comparative examples 9 and 10

A conjugate fiber was obtained in the same manner as in example 13, except that the speed of the 1 st roll was changed as shown in table 1. The results are shown in Table 2.

Examples 18 and 19 and comparative example 11

A conjugate fiber was obtained in the same manner as in example 13, except that the temperature of the roll 1 was changed as shown in table 1. The results are shown in Table 2.

Examples 20 and 21 and comparative example 12

A conjugate fiber was obtained in the same manner as in example 13, except that the roll temperature of 2 nd roll was changed as shown in table 1. The results are shown in Table 2.

Examples 22 and 23 and comparative examples 13 and 14

A conjugate fiber was obtained in the same manner as in example 13, except that the copolymerization amount of sodium 5-sulfoisophthalate in the modified polyethylene terephthalate component was changed as shown in table 1. The results are shown in Table 2.

Examples 24 and 25 and comparative examples 15 and 16

A conjugate fiber was obtained in the same manner as in example 13, 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 2.

Examples 26 and 27 and comparative example 17

A conjugate fiber was obtained in the same manner as in example 13, except that the discharge amount of each component and the 2 nd roll speed were changed as shown in table 1. The results are shown in Table 2.

In table 2, U% and hand were evaluated by the following methods.

(8)U％

The measurement was carried out under the conditions of semi-inert conditions using an Evans Tester manufactured by Measure apparatus industries, Ltd.

(9) Hand feeling

The conjugate fiber was woven into a cylindrical gray fabric, boiled and dyed with a cationic dye, washed with water, and set in dry heat at 160 ℃ for 1 minute to obtain a measurement sample. The tactile sensation was evaluated and expressed as follows.

2: has the hand feeling of the style of spun yarn.

1: the spun yarn style has insufficient hand feeling.

[ example 28]

Nylon 6 having an inherent viscosity [ eta ] of 1.3 and modified polyethylene terephthalate having an inherent viscosity [ eta ] of 0.39 and copolymerized with 3.0 mol% of sodium 5-sulfoisophthalate were melted at 270 ℃ and 290 ℃, extruded at an output of 11.7 g/min using a composite spinneret as described in Japanese patent application laid-open No. 2000-144518 to form side-by-side composite yarns, cooled and solidified to give an oil solution, drawn at a speed of 1000 m/min, preheated by a 1 st roll at a temperature of 60 ℃, and then subjected to a drawing heat treatment (drawing ratio of 2.80 times) at a speed of 2800 m/min between a 2 nd roll heated to a temperature of 130 ℃, and wound to obtain 83dtex 24fil composite fibers.

On the other hand, a polyethylene terephthalate fiber having a high shrinkage component was produced as follows. Polyethylene terephthalate having an ultimate viscosity of 0.64 and copolymerized with 10 mol% of isophthalic acid and containing 0.3% of titanium dioxide as a delustering agent was melted at 285 ℃, extruded at a discharge rate of 12g, cooled and solidified to give an oil, and then wound at a spinning speed of 1200 m/min to obtain 100 dtex 12 fil undrawn yarn. The undrawn yarn was drawn by a general drawing machine to obtain a 33 dtex 12 fil high shrinkage filament-polyethylene terephthalate fiber. The stretching conditions were as follows.

(stretching conditions)

Drawing speed 500 m/min

Draw ratio 3.0

Stretching temperature 80 deg.C

Setting temperature room temperature

Then, the low-shrinkage filaments and the high-shrinkage filaments were combined and wound while being subjected to a interlacing process, thereby obtaining a mixed filament of 117 dtex 36 fil. The number of intermingled mixed filaments was 43/m. The results are shown in Table 3.

Examples 29 to 33 and comparative examples 19 to 21

A mixed filament was obtained in the same manner as in example 28, except that the temperature of the roll 1 was changed as shown in table 3. The results are shown in Table 3.

Examples 34 to 38 and comparative examples 18 and 22 to 34

A mixed filament was obtained in the same manner as in example 28, except that the roll speed of 2 nd roll was changed as shown in table 3. The results are shown in Table 3.

Examples 39 and 40 and comparative examples 25 and 26

A mixed filament was obtained in the same manner as in example 28, except that the copolymerization amount of sodium 5-sulfoisophthalate in the modified polyester component was changed as shown in table 3. The results are shown in Table 3.

Examples 41 and 42 and comparative examples 27 and 28

A mixed filament was obtained in the same manner as in example 28, except that the intrinsic viscosity [. eta. ] of the modified polyester component was changed as shown in table 3. The results are shown in Table 3.

In table 3, the processability of the mixed fibers, the shrinkage in boiling water of the high shrinkage fibers and the composite fibers, the change in shape of the knitted cylindrical fabric, the hand and the number of intertwining were measured and evaluated by the following methods.

(10) Processability of mixed fiber

3: the broken line is broken for 0-1 time in the continuous 10-hour blending processing, and the silk making performance is good.

2: the yarn is broken for 2-4 times in the continuous 10-hour blending processing, and the silk making property is slightly poor.

1: the yarn is broken for more than 5 times in the blending processing of 10 continuous hours, and the silk making property is extremely poor.

(11) Shrinkage of high shrinkage fibers and composite fibers in boiling water

The shrinkage ratio (BWSA) of the high shrinkage fiber in boiling water and the shrinkage ratio (BWSB) of the conjugate fiber in boiling water were determined by the following methods. That is, a tape measure having a frame circumference of 1.125m was used to produce a skein, and the skein length was measured under a load of 27.7cN/dtex (L4). The load of the skein was removed and the mixture was treated in boiling water for 30 minutes. The water was wiped off, and the skein length (L5) after leaving at room temperature for 1 hour was measured and calculated from the following formula.

Percent shrinkage (L4-L5)/L4 × 100

(12) Form change of knitting cylindrical gray fabric

The mixed filaments were woven into a cylindrical gray fabric, boiled and dyed with a cationic dye, washed with water, and set in dry heat at 160 ℃ for 1 minute to obtain a measurement sample. Water was dropped onto the knitted cylindrical fabric, and the state of the portion where water was dropped and the periphery thereof were examined from a photograph (magnification 200) of the side surface of the knitted cylindrical fabric, and the state of expansion or contraction of the stitches due to the water dropping and the bottom-penetrating feeling of the knitted cylindrical fabric were visually judged.

(a) Coil change

2: the coil shrinks significantly (voids become less) due to the dripping of water.

1: the coil was stretched instead (the gap was enlarged) by dropping water.

(b) Sense of opacity

2: the feeling of penetration is reduced and the feeling of opacity is increased by adding dropwise water.

1: when water is added dropwise, the feeling of strikethrough becomes large and the feeling of transparency increases (the feeling of opacity decreases).

(13) Hand feeling

The mixed filaments were woven into a cylindrical gray fabric, boiled and dyed with a cationic dye, washed with water, and set in dry heat at 160 ℃ for 1 minute, and the feel of the sample was evaluated.

2: has bulkiness and real silk hand feeling.

1: hard to handle, or like spun-like yarns, have no lofty feel.

(14) Number of interlaces

The number of mixed filaments was calculated by adding the mixed filaments to water and counting the number of the mixed filaments by naked eyes, and the number of the mixed filaments was calculated by converting the number of the mixed filaments per 1 m.

In examples 28 to 42, it was confirmed that: among the mixed filaments, the low shrinkage filaments absorb moisture or water, and the crimp rate thereof is also increased, thereby clogging the mesh of the knitted cylindrical fabric.

[ example 43]

Nylon 6 having an inherent viscosity [ eta ] of 1.3 and modified polyethylene terephthalate having an inherent viscosity [ eta ] of 0.39 and copolymerized with 3.0 mol% of sodium 5-sulfoisophthalate were melted at 270 ℃ and 290 ℃ respectively, extruded at an ejection rate of 8.3 g/min using a composite spinneret as described in Japanese patent laid-open No. 2000-144518 to form side-by-side composite yarns, cooled to solidify and supplied with an oil, and then the yarns were wound at a speed of 1000 m/min to obtain 167 dtex 24fil undrawn yarns.

Next, polyethylene terephthalate having an inherent viscosity [ eta ] of 0.64 and containing 0.3% by weight of titanium oxide was melted at 300 ℃, extruded at an output of 40.3 g/min using a spinneret having 12 discharge holes with a hole diameter of 0.30 phi, cooled to solidify, and then wound at a spinning speed of 3300 m/min to obtain 122 dtex 24fil undrawn yarn. The obtained undrawn yarn had a strength of 2.5cN/dtex and an elongation of 135%.

The two types of undrawn yarns were combined, and subjected to a texturing treatment (texturing (1L)) in the air, and a composite false twist was performed by using a friction type false twist processing machine under the following conditions to obtain a composite false twist processed yarn of 186dtex 36 fil. The results are shown in Table 4.

(conditions for false twist processing)

Processing speed 300 m/min

Machining magnification 1.55

Processing temperature 140 deg.C (using a non-contact heater (effective length 90cm))

·D/Y 1.8

Interleaving OF: 0.5%, IL pressure: 2.0kg/cm²

Examples 44 to 48 and comparative examples 29 to 31

A composite false-twisted yarn was obtained in the same manner as in example 43, except that the composite false-twist processing temperature (heater) was changed as shown in table 4. The results are shown in Table 4.

Examples 49 to 54 and comparative examples 32 to 34

A composite false-twisted yarn was obtained in the same manner as in example 43, except that the spinning speed was changed as shown in table 4. The results are shown in Table 4.

Examples 55 and 56 and comparative examples 35 and 36

A composite false-twisted yarn was obtained in the same manner as in example 43 except that the copolymerization amount of sodium 5-sulfoisophthalate in the modified polyester component was changed as shown in table 4. The results are shown in Table 4.

Examples 57 and 58 and comparative examples 37 and 38

A composite false-twisted yarn was obtained in the same manner as in example 43 except that the intrinsic viscosity [ eta ] of the modified polyester component was changed as shown in Table 4. The results are shown in Table 4.

In examples 43 to 58, it was confirmed that: in the composite false twist processed yarn, the crimp rate of the sheath yarn is increased by moisture absorption or water absorption, as in the undrawn yarn.

The compound false twist processability, the difference in yarn length between the fiber yarns constituting the core yarn and the sheath yarn, and the change in shape and hand of the knitted cylindrical fabric described in table 4 were measured and evaluated by the following methods.

(15) Composite false twist processability

3: the composite false twisting processing for 10 hours is broken for 0 to 1 time, and the silk making performance is good.

2: the composite false twisting for 10 hours is broken for 2-4 times, and the silk making performance is slightly poor.

1: the composite false twisting process for 10 hours is broken for more than 5 times, and the silk-making property is extremely poor.

(16) Yarn length difference of fiber yarn constituting core yarn and cover yarn

A load of 0.176cN/dtex (0.2g/de) was applied to one end of 50cm of the composite false-twist textured yarn and the yarn was vertically suspended, and the yarn was accurately marked at intervals of 5 cm. The load was removed, and the marked part was accurately cut out to prepare 10 specimens. From the sample, 10 fibers (filaments) of the sheath portion and 10 fibers (filaments) of the core portion were each taken, and each filament was applied with a load of 0.03cN/dtex (1/30g/de) and suspended vertically, and the length of each filament was measured. The above measurement was performed on 10 samples, and the average values of La (sheath yarn length) and Lb (core yarn length) were defined as the yarn length difference by the following formula.

Yarn length difference (La-Lb)/La × 100%

(17) Form change of knitting cylindrical gray fabric

The composite false twist processed yarn was woven into a cylindrical gray fabric, boiled and dyed with a cationic dye, washed with water, and set in dry heat at 160 ℃ for 1 minute to obtain a measurement sample. Water was dropped onto the knitted cylindrical fabric, and the state of the portion where water was dropped and the periphery thereof were examined by a side photograph (magnification 200) of the knitted cylindrical fabric, and the state of expansion or contraction of the stitches due to the water dropping and the bottom-penetrating feeling of the knitted cylindrical fabric were visually judged.

(a) Coil change

1: the coil was stretched instead (the gap was enlarged) by dropping water.

(b) Sense of opacity

(18) Hand feeling

The composite false-twist processed yarn was woven into a cylindrical gray fabric, boiled and dyed with a cationic dye, washed with water, and set in dry heat at 160 ℃ for 1 minute, and the touch of the fabric was evaluated as a measurement sample.

2: the hand feeling is like the spun yarn, and the spun yarn has bulkiness and softness.

1: the hand feeling is not like spun yarn.

[ example 59]

Nylon 6 having an inherent viscosity [ eta ] of 1.3 and modified polyethylene terephthalate having an inherent viscosity [ eta ] of 0.39 and copolymerized with 3.0 mol% of sodium 5-sulfoisophthalate were melted at 270 ℃ and 290 ℃ respectively, extruded at an ejection rate of 11.7 g/min using a composite spinneret as described in Japanese patent laid-open No. 2000-144518 to form side-by-side composite yarns, cooled to solidify and supplied with an oil, and then the yarns were wound at a speed of 2500 m/min to obtain 110 dtex 24fil undrawn yarns. The obtained undrawn yarn was false-twisted using a friction type false twist machine under the following conditions to obtain a 72 dtex 24fil false-twisted yarn. The results are shown in Table 5.

(conditions for false twist processing)

Processing speed 300 m/min

Machining magnification 1.55

·D/Y 1.8

Examples 60 to 64 and comparative examples 39 to 41

A false-twisted yarn was obtained in the same manner as in example 59, except that the texturing (heater) temperature for false twisting was changed as shown in table 5. The results are shown in Table 5.

Examples 65 to 69 and comparative examples 42 to 45

A false-twisted yarn was obtained in the same manner as in example 59, except that the spinning speed and the false twist texturing magnification were changed as shown in table 5. The results are shown in Table 5.

Examples 70 to 72 and comparative example 46

The same operation as in example 59 was carried out except that the copolymerization amount of sodium 5-sulfoisophthalate of the modified polyethylene terephthalate was changed as shown in table 5, to obtain a false-twisted yarn. The results are shown in Table 5.

Examples 73 to 74 and comparative examples 47 and 48

A false-twisted yarn was obtained in the same manner as in example 59, except that the intrinsic viscosity [ η ] of the modified polyethylene terephthalate was changed as shown in table 5. The results are shown in Table 5.

The false twist processability, the change in shape of the knitted cylindrical fabric and the hand described in table 5 were measured and evaluated by the following methods.

(19) False twist processability

3: thread breakage is caused by continuous false twisting for 10 hours for 0-1 time, and the yarn making performance is good.

2: thread breakage is caused by continuous false twisting for 10 hours for 2-4 times, and the yarn-making property is slightly poor.

1: the yarn was broken 5 times or more after 10-hour continuous false twisting, and the yarn-forming property was extremely poor.

(20) Form change of knitting cylindrical gray fabric

The false twist processed yarn was woven into a cylindrical gray fabric, boiled and dyed with a cationic dye, washed with water, and set in dry heat at 160 ℃ for 1 minute to obtain a measurement sample. Water was dropped onto the knitted cylindrical fabric, and the state of the portion where water was dropped and the periphery thereof were examined by a side photograph (magnification 200) of the knitted cylindrical fabric, and the state of expansion or contraction of the stitches due to the water dropping and the bottom-penetrating feeling of the knitted cylindrical fabric were visually judged.

(a) Coil change

1: the coil was stretched instead (the gap was enlarged) by dropping water.

(b) Sense of opacity (sense of transparency)

(21) Hand feeling

The touch feeling of a test sample was evaluated by knitting a false twist yarn into a cylindrical gray fabric, boiling-dyeing the gray fabric with a cationic dye, washing the gray fabric with water, and then setting the gray fabric in dry heat at 160 ℃ for 1 minute.

2: soft hand feeling and bulkiness.

1: the hand feeling is like a spun-like yarn.

The false twist yarns of examples 59 to 74 had good see-through resistance and good hand feeling even when wetted with water.

Industrial applicability

The composite fiber contained in the composite fiber-containing yarn of the present invention is crimped by heating. The crimped composite fiber obtained therefrom had the following properties: the curling rate is increased by absorbing moisture or water; by drying, its curl recovered within one day. When a fabric such as a woven or knitted fabric produced from the composite fiber-containing yarn (including a false-twisted yarn) is wetted with water, the crimp ratio of the composite fiber contained therein increases, and voids in the fabric decrease. The fabric has excellent see-through resistance, wind resistance and warmth retention properties, and can maintain the above properties even after the fabric has been subjected to processing such as dyeing and post-treatment. Therefore, the conjugate fiber-containing yarn of the present invention is useful as a raw material for various fiber products, particularly for fiber products for clothing.

Claims

1. The yarn containing the composite fiber is characterized in that: comprising a conjugate fiber in which a polyester component and a polyamide component are bonded to each other in a side-by-side or eccentric sheath-core structure, wherein the conjugate fiber is heat-treated to develop crimp, and the crimp rate of the crimp-developed conjugate fiber is increased by moisture absorption or water absorption.

2. The conjugate fiber-containing yarn according to claim 1, wherein the yarn comprising conjugate fibers is subjected to boiling water treatment for 30 minutes to develop crimp, and thereafter, the crimp is formed at 1.76 x 10^-3The resultant was subjected to a heat treatment at 100 ℃ for 30 minutes under a load of CN/dtex to stabilize the curl, and the resultant was further subjected to a heat treatment at 1.76X 10^-3When the crimped conjugated fiber is subjected to heat treatment at 160 ℃ for 1 minute under a load of CN/dtex, and the dry crimp rate DC after the heat treatment and the wet crimp rate HC after the crimped conjugated fiber having the dry crimp rate DC are immersed in water at 20 to 30 ℃ for 10 hours are measured, the difference Δ C between the wet and dry crimp rates represented by the following formula is 0.3% or more:

ΔC(％)＝HC(％)-DC(％)。

3. the conjugate fiber-containing yarn as claimed in claim 1, wherein the polyester component comprises a modified polyester obtained by copolymerizing 2.0 to 4.5 mol% of sodium 5-sulfoisophthalate, based on the total molar amount of the acid component, and has an intrinsic viscosity IV in the range of 0.30 to 0.43.

4. The conjugated fiber-containing yarn according to claim 2, wherein the dry crimp DC is in the range of 0.2 to 6.7%, and the wet crimp HC is in the range of 0.5 to 7.0%.

5. The conjugate fiber-containing yarn as claimed in claim 1 or 2, wherein said conjugate fiber-containing yarn comprises coarse and fine conjugate fibers alternately arranged in coarse and fine portions along the length direction thereof.

6. The conjugated fiber-containing yarn according to claim 5, wherein the dry crimp DC of the thick and thin conjugated fiber yarn is in the range of 4.0 to 12.8%, and the wet crimp HC is in the range of 4.3 to 13.0%.

7. The conjugated fiber-containing yarn according to claim 5, wherein the U% of the thick-thin conjugated fiber yarn is in the range of 2.5 to 15.0%.

8. The conjugate fiber-containing yarn according to any one of claims 1 to 7, wherein a yarn comprising one or more fibers having a higher shrinkage in boiling water than that of the conjugate fiber is combined with the conjugate fiber-containing yarn, and the conjugate fiber is blended with the high-shrinkage fiber.

9. The conjugate fiber-containing yarn according to claim 8, wherein the yarn comprising the conjugate fiber has a boiling water shrinkage BWSB of 12 to 30%, the high shrinkage fiber yarn has a boiling water shrinkage BWSA of 40% or less, and the difference between the two shrinkages, BWSA and BWSB, is 10 to 26%.

10. The composite fiber-containing yarn according to any one of claims 1 to 7, which is a sheath-core composite false-twisted yarn obtained by false-twisting a composite yarn obtained by using the yarn containing the composite fiber as a sheath yarn and using a filament yarn of a different type from the sheath yarn as a core yarn, a sample having a length of 50cm is taken from the sheath-core composite false-twisted yarn, a load of 0.176cN/dtex, i.e., 0.2g/de, is applied to one end of the sample and suspended vertically, the sample is marked at 5cm intervals, the load is removed, the marked portion is cut out to prepare 10 measurement samples, 10 sheath filaments and core filaments are taken from the sample, a load of 0.03cN/dtex, i.e., 1/30g/de, is applied to each of the filaments and suspended vertically, the respective lengths are measured, and the average values of the measurement values of the 10 samples in the core/sheath are taken as the sheath length La and the core length Lb, the yarn length difference was calculated from the following formula:

yarn length difference (La-Lb)/La × 100%

In this case, the difference in yarn length (La-Lb)/La (%) is 5 to 20%.

11. The conjugate fiber-containing yarn according to any one of claims 1 to 7, which is a false-twisted yarn obtained by false-twisting the conjugate fiber-containing yarn and has an increased crimp rate due to moisture absorption or water absorption.

12. The conjugate fiber-containing yarn as claimed in claim 11, wherein the false twist textured conjugate fiber-containing yarn is subjected to boiling water treatment for 30 minutes and thereafter treated at 1.76X 10^-3The mixture was subjected to dry heat treatment at 100 ℃ for 30 minutes under a load of CN/dtex, and then subjected to dry heat treatment at 1.76X 10^-3After dry heat treatment at 160 ℃ for 1 minute under a load of CN/dtex, the dry crimp rate TDC of the composite fiber false-twist processed yarn is 5.0 to 23.7%; after the composite fiber false-twist yarn is immersed in water at 20 to 30 ℃ for 10 minutes, the wet crimp rate THC is 5.3 to 24%, and the difference between the wet crimp rate THC and the wet crimp rate THC, i.e., the crimp rate Delta TC expressed by THC-TDC, is 0.3 to 8.0%.