JP2023002952A - Fusion false-twisted yarn and knitted fabric - Google Patents

Abstract

To provide a stretch fusion false-twisted yarn and knitted fabric having excellent cool feeling and surface quality even after long-term repeating washing.SOLUTION: A fusion false-twisted yarn comprises eccentric sheath-core composite fibers composed of a polymer A and a polymer B which are two kinds of polyethylene terephthalate components, in which the difference of a weight-average molecular weight MwA of the polymer A and a weight-average molecular weight MwB of the polymer B, (MwA-MwB), is 2,000-15,000.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a stretch fused false twisted yarn and a woven or knitted fabric having excellent refreshing feeling and surface quality even after repeated washing for a long period of time.

BACKGROUND ART Fused false-twisted yarns using thermoplastic filaments such as polyethylene terephthalate fibers have been known as synthetic fibers with a refreshing feel.

For example, in Patent Document 1, by false twisting under specific false twisting conditions using highly oriented polyester undrawn yarn, single yarns are partially or continuously fused in the length direction. is disclosed. However, in such a conventional fused false twisted yarn, no crimp occurs in the fused portion, and high stretchability cannot be imparted to the woven or knitted fabric.

Further, Patent Document 2 proposes a fusion-bonded false-twisted yarn obtained by conjugate-spinning polytrimethylene terephthalate and a second component polymer in a side-by-side type or eccentric sheath-core type. With this method, stretchability can be imparted to the woven or knitted fabric, but if the second component is other than polytrimethylene terephthalate, the melting point will be different from that of polytrimethylene terephthalate. In order to achieve this, it is necessary to set the false twist temperature to a polymer with a high melting point. Therefore, the fusion bonding strength is inevitably increased, and since the coil crimp does not occur in the fusion bonding portion, there is a problem that the quality of the woven or knitted fabric is deteriorated. On the other hand, even if the second component is polytrimethylene terephthalate, due to the low Young's modulus characteristic of polytrimethylene terephthalate, when an external force is applied by repeated washing, the fused part tends to unravel and the cool feeling is lost. I had a problem.

Japanese Patent Application Laid-Open No. 52-49322 Japanese Patent Application Laid-Open No. 2005-298980

The present invention overcomes the problems of the prior art and relates to a stretch fused false-twisted yarn and a woven or knitted fabric that have excellent refreshing feeling and surface quality even after repeated washing for a long period of time.

In order to solve the above problems, the fusible false-twisted yarn of the present invention has the following constitution. i.e.
The difference between the weight average molecular weight Mw _A of the polymer A and the weight average molecular weight Mw _B of the polymer B (Mw _A −Mw _B ) is between 2,000 and 15,000.

The woven or knitted fabric of the present invention has the following configuration. i.e.
A woven or knitted fabric containing the fusible false-twisted yarn at a weight ratio of 20% or more.

In the fused false twisted yarn of the present invention, the polymer A component is completely covered with the polymer B component in the cross section of the eccentric core-sheath composite fiber, and the thickness of the polymer B component covering the polymer A component is The ratio S/D of the minimum thickness S to the fiber diameter D is 0.01 to 0.2, and the length of the portion whose thickness is within 1.10 times the minimum thickness S is the total length of the eccentric core-sheath composite fiber. It is preferably 1/3 or more of the peripheral length.

The woven or knitted fabric of the present invention preferably has an average length of 3 mm or more at the fused portion after 20 washes.

By using the fused false-twisted yarn defined in the present invention, it is possible to provide a stretch woven or knitted fabric having excellent cool feeling and surface quality even after repeated washing for a long period of time.

1 is a drawing-substituting photograph showing an example of a fiber cross-section of an eccentric core-sheath composite fiber used in the present invention. It is an example of the eccentric core-sheath composite fiber used in the present invention, and is a fiber cross section for explaining the center of gravity position in the fiber cross section. It is a fiber cross section for explaining the fiber diameter (D) and the minimum thickness (S) in the fiber cross section of the eccentric core-sheath composite fiber used in the present invention.

The present invention will be described in detail below along with preferred embodiments.

In addition, in the above two types of polyethylene terephthalate components, the difference (Mw _A −Mw _B ) between the weight average molecular weight Mw _A of polymer A and the weight average molecular weight Mw _B of polymer B, that is, the weight average molecular weight difference is 2,000 to With a molecular weight of 15,000, the fibers are largely curved toward the high weight average molecular weight side after heat treatment, and are continuous to form a three-dimensional coil structure. Therefore, the structure expands and contracts like a spring, and excellent stretchability can be obtained after false twisting. In addition, in order to achieve stretchability in a woven or knitted fabric using a conventional fused false twisted yarn, the morphological difference between the crimped form of the non-fused part and the non-crimped form of the fused part becomes large, and the woven or knitted fabric is worm-eaten. However, in the fused false twisted yarn of the present invention, by adopting the above-described polymer structure, the coil crimp is expressed even in a part of the fused portion, resulting in an excellent surface. It has become possible to obtain quality woven or knitted fabrics. If the weight-average molecular weight difference is less than 2,000, the fused portions of the fused false twisted yarn cannot develop coil crimps, resulting in deterioration of the woven or knitted quality. If the weight-average molecular weight difference exceeds 15,000, spun yarn breaks occur frequently and stable production cannot be achieved. Here, the preferred weight average molecular weight difference is 4,000 to 13,000.

Further, the range of Mw _A is preferably from 20,000 to 28,000, and the range of Mw _B is preferably from 12,000 to 20,000. This range is preferable because the spinnability of the eccentric core-sheath composite fiber and the stretchability of the woven or knitted product are improved.

The weight-average molecular weight in the present invention is measured by preparing a measurement solution by completely dissolving 2.0 mg of conjugate fiber in 2.5 cm ³ of tetrahydrofuran, and performing a gel permeation chromatography test using polystyrene as a standard substance. As a gel permeation chromatography (GPC) tester, for example, "TOSO GMHHR-H(S)HT" manufactured by Tosoh Corporation is used.

Further, as the polyethylene terephthalate component used in the present invention, a polyester containing terephthalic acid as a main acid component and ethylene glycol as a main glycol component and having 90 mol % or more of repeating units of ethylene terephthalate can be used. In addition, other copolymer components capable of forming an ester bond may also be included within a range that does not impair the effects of the present invention. Examples of copolymerizable compounds include dicarboxylic acids such as isophthalic acid, cyclohexanedicarboxylic acid, adipic acid, dymic acid, sebacic acid and sulfoisophthalic acid, diol components and oxycarboxylic acid components.

The polyethylene terephthalate in the present invention may contain titanium oxide, micropore-forming agent, cationic dyeing agent, anti-coloring agent, heat stabilizer, flame retardant, fluorescent agent and One or more of brightening agents, matting agents, coloring agents, antistatic agents, moisture absorbents, antibacterial agents, inorganic fine particles and the like may be contained.

In addition, the fiber cross section of the eccentric core-sheath composite fiber used in the present invention has a composite cross section formed by bonding two different polymers, and the two polymers having different polymer properties are bonded without substantially separating. It is preferably of the eccentric sheath-core type in which the B component completely covers the A component.

Here, the term "eccentricity" as used in the present invention means that the position of the center of gravity of the polymer A component in the cross section of the conjugate fiber is different from the center of the cross section of the conjugate fiber. A specific description will be given below with reference to FIG. In FIG. 2, the horizontal hatching is the polymer B component, the 30-degree hatching (slanting lines rising to the right) is the polymer A component, the center of gravity of the polymer A component in the cross section of the composite fiber is the center of gravity point a, and the center of gravity of the cross section of the composite fiber is C is the center of gravity.

In the eccentric core-sheath composite fiber used in the present invention, the separation of the center of gravity point a from the center of gravity point C of the cross section of the composite fiber (eccentricity) causes the fiber to bend greatly toward the high weight average molecular weight side after heat treatment. Thus, the high weight-average molecular weight component shrinks relatively more strongly than the low weight-average molecular weight component, whereby the eccentric core-sheath composite fiber continues to bend in the fiber axis direction. As a result, the eccentric core-sheath composite fiber has a three-dimensional coil structure and exhibits excellent crimp. Here, the further the center of gravity is, the more favorable the crimp is and the better the stretching performance can be obtained. In the fused false twisted yarn of the present invention, the polymer B component completely covers the polymer A component, so that the fused state can be made stronger even after repeated washing for a long period of time, resulting in an excellent cool feeling. It is preferable because it can be maintained.

In the fused false twisted yarn of the present invention, the ratio S/D of the minimum thickness S of the B component covering the polymer A component to the fiber diameter (diameter of the composite fiber) D is 0.01 to 0.2. It is preferably from 0.02 to 0.08, since it is possible to obtain a more excellent stretching performance and a strong fused form.

A more detailed explanation will be given using the fiber cross section shown in FIG. Here, the minimum thickness S is the thinnest portion of the B component in the core-sheath composite fiber.

Furthermore, the length of the part with a thickness within 1.10 times the minimum thickness S (hereinafter sometimes referred to as the "minimum thickness part") occupies 1/3 or more of the entire perimeter of the conjugate fiber. preferable. This means that the polymer A component exists along the contour of the fiber, and compared with the conventional eccentric core-sheath composite fiber with the same area ratio, the present invention has a fiber cross section of each component. The center of gravity is farther apart, forming fine coils and developing good crimps. More preferably, the length of the portion having a thickness within 1.10 times the minimum thickness S is set to 2/5 or more of the circumference of the entire fiber to obtain good stretchability.

A method for measuring the minimum thickness S and the fiber diameter D is shown below.

A multifilament consisting of an eccentric core-sheath composite fiber is embedded in an embedding agent such as epoxy resin, and a cross section perpendicular to the fiber direction is examined with a transmission electron microscope (TEM) at 10 or more fibers (points). The image is taken at a magnification that allows observation of At this time, if metal dyeing is applied, the difference in dyeing between polymers can be used to clarify the contrast of the junction between the polymer A component and the polymer B component. It can be confirmed that the eccentric core-sheath composite fiber has two components due to the presence of the joint. Set a circle circumscribing the cross section of 10 (places) eccentric core-sheath composite fiber monofilaments randomly extracted from each photographed image within the same image, and measure the circumscribed circle diameter. The value obtained corresponds to the fiber diameter D referred to in the present invention. The circle circumscribing the cross section here is a perfect circle that circumscribes the cross section perpendicular to the fiber axis from the image taken two-dimensionally, and circumscribes this cutting plane at two or more points. The circle diameter means the diameter of the perfect circle. Further, using the image obtained by measuring the fiber diameter D, the minimum thickness of the polymer B component covering the polymer A component for 10 or more fibers (locations) is measured, which is the minimum thickness referred to in the present invention. corresponds to S. Further, the fiber diameter D and the minimum thickness S are measured in units of μm and rounded off to the third decimal place. A simple numerical average value of the measured values and their ratio (S/D) is calculated for ten images photographed during the above operation. Using the image taken above and the image analysis software "WinROOF2015" (manufactured by Mitani Shoji Co., Ltd.), after obtaining the area of the entire fiber and the areas of the A component and the B component, the center of the specific gravity and the area ratio can be asked for.

In addition, the length of the portion within 1.10 times the minimum thickness S is preferably 1/3 or more of the peripheral length of the entire fiber, more preferably within 1.05 times the minimum thickness S. A good stretchability can be obtained by setting the length to 2/5 or more of the circumference of the entire fiber, and this length can also be measured by the same method as described above.

In order to enhance the stretchability of the fused false twisted yarn of the present invention, the ratio of the two components is preferably in the range of polymer A component: polymer B component = 70:30 to 30:70 (area ratio), 65:35 to A range of 45:55 is more preferred.

The fused false twisted yarn of the present invention is a false twisted yarn partially having a fused portion. By subjecting the eccentric core-sheath composite fiber to false twisting at a high temperature, a fused portion can be formed in a portion of the textured yarn, and a cool feeling can be imparted to the woven or knitted fabric.

The fiber cross-section of the fused false twisted yarn of the present invention may be round, triangular, flat, hexagonal, L-shaped, T-shaped, W-shaped, eight-lobed, dog-bone or other polygonal, polymorphic or hollow. can be selected, but a round shape is preferred for enhanced stretch properties.

Further, it is preferable that the fineness of the fusible false twisted yarn of the present invention is 30 to 330 dtex, and the single yarn fineness is 0.5 to 10 dtex, in order to impart stretchability and refreshing feeling to the woven or knitted fabric.

It is also possible to use two or more fused false twisted yarns of the present invention and other polyethylene terephthalate fibers (the same eccentric core-sheath composite fibers may be used) in a plied yarn or a mixed yarn. In the mixed yarn of the eccentric core-sheath composite fiber and other fibers used in the present invention, the ratio of the eccentric core-sheath composite fiber is preferably in the range of 20 to 80% by mass.

The woven or knitted fabric of the present invention can impart a refreshing feeling to the woven or knitted fabric by containing at least 20% by weight of the fusible false twisted yarn. If it is less than 20%, the woven or knitted fabric lacks a cool feeling. In order to maintain a cool feeling, the average length of the fused portions is preferably 3 to 30 mm, and the average number of the fused portions is preferably 5 to 100. More preferably 5 to 20 mm and 10 to 50.

In order to maintain a cool feeling even after repeated washing, it is preferable that the average length of the fused portion after 20 washings is 3 mm or more.

The woven or knitted fabric of the present invention preferably has an elongation rate of 10% or more under a load of 1.5 kgf (14.7 N) in at least one of the warp and weft directions. More preferably, it is 15% or more. As a result, it is possible to maintain a refreshing feeling even after repeated washing even in a wide range of clothing applications such as jackets, suits, bottoms, uniforms, shirts, student clothing, athletic clothing, skirts, and innerwear, which is preferable.

Next, a preferred method for producing the fusion-bonded false-twisted yarn of the present invention will be described.

It is preferable to precisely control the thickness of the sheath and the peripheral length of the thin skin portion of the eccentric core-sheath composite fiber used in the present invention. A method using a distribution plate as exemplified in Japanese Patent Application Laid-Open No. 2012-136804 is preferably used. When a composite yarn having an eccentric core-sheath type cross section is produced using a conventionally known composite spinneret, it is often very difficult to precisely control the position of the center of gravity of the core and the thickness of the sheath. For example, if the thickness of the sheath becomes thin and the core component is exposed, it will cause a decrease in the fusion bondability in repeated washing for a long period of time. As a result, there may be a problem that the stretching performance is deteriorated.

The eccentric core-sheath composite fiber used in the present invention is preferably wound as undrawn yarn or highly oriented undrawn at a spinning speed of 1,500 to 3,800 m/min.

In the eccentric core-sheath composite fiber used in the present invention, it is preferable that the polymer A component is completely covered with the polymer B component as shown in FIG. By making the cross section specified in the present invention, it is possible to suppress the bending of the ejection line (kneeing phenomenon) caused by the difference in flow velocity between the two types of polymers during ejection from the die. In addition, in the case of the conventional simple bonding structure (bimetal structure), there is a difference in the stress balance applied to each polymer when thinning on the spinning wire after ejection from the spinneret, and unevenness occurs in extensional deformation, which is the fineness unevenness. , and U % became large. This tendency appears very conspicuously in a combination of polymers with a large difference in viscosity and molecular weight. Fineness unevenness can be suppressed.

Subsequently, the fused false twisted yarn used in the present invention can be obtained by processing the eccentric core-sheath composite fiber under high temperature false twisting conditions. Any false twisting condition can be selected as the false twisting condition, but the false twisting temperature is preferably 180 to 235° C. in the case of a contact heater. More preferably, it is 210 to 230°C. The twister may be of spindle type, friction disk type, or belt nip type. Regarding the number of false twists, setting the false twist coefficient (number of false twists (T/M) × fineness (dtex) ^0.5 ) in the range of 15,000 to 33,000 is effective for strong crimping and melting. It is preferable in that it can impart wear.

Further, in order to further improve the refreshing feeling, it is also possible to apply heat drawing at a low draw ratio before false twisting to impart thick portions and fine details to the fibers. Further, in order to reduce the residual torque, heat setting with a heater after false twisting does not pose a problem. As for the yarn processing speed, the higher the productivity, the better.

In the woven or knitted fabric using the fusible false twisted yarn of the present invention, the woven fabric can be selected from any fabric such as plain, twill, satin, Amundsen, and double weave. As the knitting structure, an arbitrary structure such as jersey, smooth, half, or double raschel can be selected. The thus-obtained woven or knitted fabric of the present invention has sufficient stretchability, and can provide excellent refreshing feeling and surface quality even after repeated washing for a long period of time. This woven or knitted fabric is suitably used for a wide range of clothing applications such as jackets, suits, bottoms, uniforms, shirts, student clothing, athletic clothing, skirts and innerwear.

The false-twisted fusible yarn and the woven or knitted fabric of the present invention will be specifically described below with reference to examples. Examples and comparative examples were evaluated as follows.

(1) Measurement of Weight Average Molecular Weight of Thermoplastic Resin As a gel permeation chromatography (GPC) tester, "TOSO GMHHR-H(S)HT" manufactured by Tosoh Corporation was used.

(2) Fineness 100 skeins were produced using a measuring machine with a frame circumference of 1.0 m, and the fineness was measured according to the following formula.

Fineness (dtex) = Skein weight (g) for 100 times x 100
(3) Crimp rate The yarn was wound 10 times under a tension of 90 mg/dtex on a measuring machine with a circumference of 0.8 m to remove the skein, then suspended from a rod of 2 cm or less and left for about 24 hours. This skein was wrapped in gauze, treated with hot water at 90° C. for 20 minutes under tensionless conditions, and then hung from a rod of 2 cm or less and left for about 12 hours. After standing, one end of the skein was hung on a hook, and the initial load and the measurement load were applied to the other end, and the skein was suspended in water and left for 2 minutes. The initial load (g) at this time was 2 mg/dtex, the measurement load (g) was 90 mg/dtex, and the water temperature was 20±2°C. The inner length of the left skein was measured and designated as L. Furthermore, the measurement load was removed and only the initial load was applied, and the sample was allowed to stand for 2 minutes. The crimp was determined by the following formula, and this operation was repeated 5 times, and the average value was determined.

Crimp rate (%) = {(L - L1) / L} x 100
(4) Elongation rate Elongation rate under a load of 1.5 kgf (14.7 N) was measured according to B method described in JIS L 1096 (2010). This elongation rate was used as a measure of stretchability.

(5) Average length and number of fused portions Observation was made with an optical microscope (VHX-2000 manufactured by Keyence Corporation) to measure the average length and number of fused portions per 1 m of yarn. This operation was repeated 5 times, and the average value was obtained.

Regarding the average length of the fused portion and the number of fused portions after repeated washing, the fused false twisted yarn is carefully extracted from the woven or knitted fabric so as not to damage the fused portion. The knitted fabric was washed in a two-tank washing machine at a liquid temperature of 40°C for 5 minutes, rinsed at 30°C x 2 minutes x 2 times, and dehydrated once for 30 seconds. 1 g/L of "Attack" (registered trademark) manufactured by Kao Corporation was used as the detergent, the amount of liquid was 40 L, and the total weight of the test cloth and the cotton cloth used as the guide cloth was 830 g. After repeating this washing operation 20 times, the above evaluation was carried out.
(6) Refreshing Feeling The woven or knitted fabric subjected to the same repeated washing treatment as in (5) has a very excellent refreshing feeling, an excellent refreshing feeling, or a slightly lacking refreshing feeling in the sensory evaluation. , Lack of cooling sensation, and evaluated on a 4-point scale, and a result close to the average of the evaluations of 10 randomly selected people was taken.
(7) Surface quality In woven and knitted fabrics that have been subjected to the same repeated washing treatment as in (5), the sensory evaluation shows that the surface quality is very good, the surface quality is excellent, and the surface is grainy. , and worm-eaten holes on the surface.

[Example 1]
Polyethylene terephthalate with a weight average molecular weight of 25,000 as the polymer A component, polyethylene terephthalate with a weight average molecular weight of 15,000 as the polymer B component, the weight composite ratio of the polymer A component and the polymer B component is 50/50, and the number of discharge holes is 24. It was made to flow into a spinneret for eccentric core-sheath composite fibers. Each polymer merges inside the spinneret to form an eccentric core-sheath composite form in which the polymer of polymer A component is included in the polymer of polymer B component, and spun from the spinneret at a spinning speed of 2,800 (m/min). A highly oriented undrawn yarn having a fineness of 125 dtex, 36 filaments and an elongation of 145% was obtained. In addition, in the spinning of Example 1, a spinneret of a distribution plate type was used so as to obtain the eccentric core-sheath composite fiber shown in FIG. The S/D in the cross section of the fiber was 0.02, and the length of the minimum thickness portion accounted for 40% of the total peripheral length of the eccentric core-sheath composite fiber.

Next, using a friction false twister (ATF12: manufactured by TMT Machinery Co., Ltd.), the highly oriented undrawn yarn was fed from a feed roller, processing speed: 400 m / min, draw ratio: 1.5 times, heater temperature : 220°C, false twist coefficient: 28,000, fineness: 84 dtex, crimp ratio: 38%, average length of fused part: 15.3 mm, number of fused parts: 24.1 / m was obtained.

Then, using the above yarns as warp and weft, a plain weave is woven with an air jet loom. Next, the obtained woven fabric is subjected to continuous scouring at 98°C, liquid flow relaxation at 120°C, intermediate set at 180°C, and 130°C. °C dyeing and 160°C finishing setting were performed to obtain a product with a processing density (warp: 95/2.54cm, weft: 90/2.54cm). The resulting woven fabric had an elongation rate of 15.5% in the warp and 20.4% in the weft, showing excellent stretchability. In addition, the average length of the fused part after 20 washes was 15.1 mm, and the number of fused parts was 22.9/m. there were. Table 1 shows the evaluation results of the properties of the eccentric core-sheath composite fiber, the properties of the fusible false twisted yarn, the properties of the woven fabric, and the like.

[Example 2]
Spinning was carried out in the same manner as in Example 1 except that polyethylene terephthalate having a weight average molecular weight of 19,000 was used as the polymer A component to obtain a highly oriented undrawn yarn having a fineness of 125 dtex, 36 filaments and an elongation of 142%. The S/D in the cross section of the fiber was 0.1, and the length of the minimum thickness portion accounted for 35% of the peripheral length of the entire eccentric core-sheath composite fiber.

Next, using a friction false twister (ATF12: manufactured by TMT Machinery Co., Ltd.), the highly oriented undrawn yarn was fed from feed rollers, processing speed: 400 m / min, draw ratio: 1.45 times, heater temperature : 225 ° C., false twist coefficient: 27,000, fineness: 88 dtex, crimp ratio: 30%, average length of fused part: 17.2 mm, number of fused parts: 32.5 / m was obtained.

Thereafter, weaving and dyeing processing were performed in the same manner as in Example 1 to obtain a product. The resulting woven fabric had an elongation rate of 12.1% in the warp and 17.8% in the weft, showing excellent stretchability. In addition, the average length of the fused part after 20 washes was 16.9 mm, and the number of fused parts was 28.0/m. there were. Table 1 shows the evaluation results of the properties of the eccentric core-sheath composite fiber, the properties of the fusible false twisted yarn, the properties of the woven fabric, and the like.

[Example 3]
Spinning was carried out in the same manner as in Example 1 except that polyethylene terephthalate having a weight average molecular weight of 28,000 was used as the polymer A component to obtain a highly oriented undrawn yarn having a fineness of 125 dtex, 36 filaments and an elongation of 141%. . The S/D in the cross section of the fiber was 0.02, and the length of the minimum thickness portion accounted for 40% of the total peripheral length of the eccentric core-sheath composite fiber.

Next, using a friction false twister (ATF12: manufactured by TMT Machinery Co., Ltd.), the highly oriented undrawn yarn was fed from a feed roller, processing speed: 400 m / min, draw ratio: 1.5 times, heater temperature : 215 ° C., false twist coefficient: 29,000, fineness: 84 dtex, crimp ratio: 44%, average length of fused part: 8.6 mm, number of fused parts: 11.2 / m was obtained.

Thereafter, weaving and dyeing processing were performed in the same manner as in Example 1 to obtain a product. The resulting woven fabric had an elongation rate of 21.2% in the warp and 25.6% in the weft, showing excellent stretchability. In addition, the average length of the fused portion after 20 washes was 8.0 mm, and the number of fused portions was 11.0 per m. rice field. Table 1 shows the evaluation results of the properties of the eccentric core-sheath composite fiber, the properties of the fusible false twisted yarn, the properties of the woven fabric, and the like.
[Comparative Example 1]
Polyethylene terephthalate with a weight average molecular weight of 32,000 as the polymer A component, polyethylene terephthalate with a weight average molecular weight of 15,000 as the polymer B component, the weight composite ratio of the polymer A component and the polymer B component is 50/50, and the number of discharge holes is 24. Spinning was carried out from a side-by-side spinneret at a spinning speed of 2,800 m/min to obtain a highly oriented undrawn yarn having a fineness of 125 dtex, 36 filaments and an elongation of 144%. The S/D in the cross section of the fiber was 0, and the ratio of the length of the minimum thickness portion to the total peripheral length of the eccentric core-sheath composite fiber was 0%.

Next, using a friction false twister (ATF12: manufactured by TMT Machinery Co., Ltd.), the highly oriented undrawn yarn was fed from a feed roller, processing speed: 400 m / min, draw ratio: 1.5 times, heater temperature : 220 ° C., false twist coefficient: 28,000, fineness: 84 dtex, crimp ratio: 48%, average length of fused part: 6.5 mm, number of fused parts: 10.6 / m was obtained.

Thereafter, weaving and dyeing processing were performed in the same manner as in Example 1 to obtain a product. The resulting woven fabric had an elongation rate of 22.2% in the warp and 26.1% in the weft, showing excellent stretchability. The average length of the fused portions after 20 washes was 2.5 mm, and the number of fused portions was 9.0/m. It was textile quality. Table 1 shows the evaluation results of the properties of the eccentric core-sheath composite fiber, the properties of the fusible false twisted yarn, the properties of the woven fabric, and the like.

[Comparative Example 2]
Spinning was carried out in the same manner as in Example 1 except that polyethylene terephthalate with a weight average molecular weight of 16,000 was used as the polymer A component to obtain a highly oriented undrawn yarn with a fineness of 125 dtex, 36 filaments and an elongation of 143%. . The S/D in the cross section of the fiber was 0.02, and the length of the minimum thickness portion accounted for 40% of the total peripheral length of the eccentric core-sheath composite fiber. Next, using a friction false twister (ATF12: manufactured by TMT Machinery Co., Ltd.), the highly oriented undrawn yarn was fed from a feed roller, processing speed: 400 m / min, draw ratio: 1.5 times, heater temperature : 220°C, false twist coefficient: 28,000, fineness: 84 dtex, crimp ratio: 20%, average length of fused part: 17.4 mm, number of fused parts: 18.1 pieces/m was obtained.

Thereafter, weaving and dyeing processing were performed in the same manner as in Example 1 to obtain a product. The elongation rate of the obtained fabric was 12.1% in the warp and 13.8% in the weft. After 20 washes, the average length of the fused portion was 17.0 mm, and the number of fused portions was 17.5/m. No coil crimp was applied, and the quality of the fabric was worm-eaten. Table 1 shows the evaluation results of the properties of the eccentric core-sheath composite fiber, the properties of the fusible false twisted yarn, the properties of the woven fabric, and the like.

[Comparative Example 3]
Spinning was performed in the same manner as in Example 1 except that polytrimethylene terephthalate having a weight average molecular weight of 25,000 was used as the polymer A component and polytrimethylene terephthalate having a weight average molecular weight of 15,000 was used as the polymer B component. A highly oriented undrawn yarn of 125 dtex, 36 filaments and an elongation of 140% was obtained. The S/D in the cross section of the fiber was 0.02, and the length of the minimum thickness portion accounted for 40% of the total peripheral length of the eccentric core-sheath composite fiber. Next, using a friction false twister (ATF12: manufactured by TMT Machinery Co., Ltd.), the highly oriented undrawn yarn was fed from a feed roller, processing speed: 400 m / min, draw ratio: 1.5 times, heater temperature : 210 ° C., false twist coefficient: 28,000, fineness: 84 dtex, crimp ratio: 41%, average length of fused part: 9.8 mm, number of fused parts: 15.0 / m was obtained.

Thereafter, weaving and dyeing processing were performed in the same manner as in Example 1 to obtain a product. The resulting woven fabric had an elongation rate of 19.5% in the warp and 23.4% in the weft, showing excellent stretchability. However, after 20 washes, the average length of the fused portion was 2.6 mm, and the number of fused portions was 4.6/m. The woven fabric lacked a cool feeling. Table 1 shows the evaluation results of the properties of the eccentric core-sheath composite fiber, the properties of the fusible false twisted yarn, the properties of the woven fabric, and the like.

[Comparative Example 4]
A highly oriented undrawn yarn obtained by the same method as in Example 1 was fed from feed rollers using a friction false twister (ATF12: manufactured by TMT Machinery Co., Ltd.), processing speed: 400 m / min, draw ratio: False twisting is performed at 1.5 times, heater temperature: 160°C, false twist coefficient: 28,000, fineness: 84 dtex, crimp rate: 41%, average length of fused portion: 0 mm, number of fused portions: 0 A false twisted yarn of pcs/m was obtained. The S/D in the fiber cross-section of the highly oriented undrawn yarn was 0.02, and the length of the minimum thickness portion accounted for 40% of the total peripheral length of the eccentric core-sheath composite fiber.

Thereafter, the false twisted yarn is used as the warp, and the false twisted yarn and the fused false twisted yarn obtained by the same method as in Example 1 are used as the weft in a 2:1 arrangement, and woven into a plain weave with an air jet loom. (The ratio of fused false twisted yarn was 16%.)
Next, the obtained woven fabric was subjected to continuous scouring at 98 ° C, liquid flow relaxation at 120 ° C, intermediate setting at 180 ° C, dyeing at 130 ° C, finishing setting at 160 ° C, processing density (warp: 95 / 2.54 cm, weft : 90 pieces/2.54 cm). The resulting woven fabric had an elongation rate of 20.5% in the warp and 23.4% in the weft, showing excellent stretchability. The average length of the fused portion of the fused false twisted yarn after 20 washes was 15.3 mm, and the number of fused portions was 23.0 pieces/m. It was the fabric that was in short supply. Table 1 shows the evaluation results of the properties of the eccentric core-sheath composite fiber, the properties of the fusible false twisted yarn, the properties of the woven fabric, and the like.

According to the present invention, a stretch woven or knitted fabric having excellent coolness and surface quality even after repeated washing for a long period of time can be provided by using the specified fused false twisted yarn.

1 Polymer A component 2 Polymer B component a: Center of gravity of polymer A component in conjugate fiber cross section C: Center of gravity of conjugate fiber cross section S: Minimum thickness of polymer B component D: Fiber diameter

Claims (4)

The difference between the weight average molecular weight Mw _A of the polymer A and the weight average molecular weight Mw _B of the polymer B (Mw _A −Mw _B ) is 2,000 to 15,000. In the cross section of the eccentric core-sheath composite fiber, the polymer A component is completely covered with the polymer B component, and the ratio of the minimum thickness S of the thickness of the polymer B component covering the polymer A component to the fiber diameter D S/D is 0.01 to 0.2, and the length of the portion whose thickness is within 1.10 times the minimum thickness S is 1/3 or more of the circumference of the entire eccentric core-sheath composite fiber. The fusible false-twisted yarn according to claim 1, characterized in that: A woven or knitted fabric containing at least 20% by weight of the fusible false twisted yarn according to claim 1 or 2. The woven or knitted fabric according to claim 3, wherein the average length of the fused portion after 20 washes is 3 mm or more.

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