JP6753182B2 - Aromatic polyester composite fiber - Google Patents

Description

The present invention relates to a polyester-based composite fiber having excellent abrasion resistance, interfacial peeling resistance, and excellent stretchability, and having latent crimping performance suitable for stretchable woven fabrics.

In recent years, the demand for functionality, especially stretchability, of woven and knitted fabrics has become stronger. The stretch performance of this woven or knit has a close relationship between the comfort when wearing clothes and the feeling of oppression. For example, if the stretch performance is good, the stretch and contraction of the woven and knit is due to the movement of each part of the body. Since it can be easily followed, there is no feeling of oppression, and activities during wearing can be performed smoothly. In recent years, the development of applications for elastic woven knits that take advantage of this feature is accelerating, and the application to sportswear and the like is rapidly increasing.

Among them, polyester fibers are widely used for stretchable woven and knitted fabrics due to their excellent mechanical properties and low cost, and various methods are adopted to give elasticity to fabrics using polyester fibers. ing. For example, a method in which polyurethane-based elastic fibers are mixed in a woven fabric to impart elasticity, or a fiber in which polyester fibers are false-twisted to express twisting / untwisting torque is used to make the woven fabric elastic. As a method of imparting the above, and a method of not using polyurethane fibers or false twisted yarns, various side-by-side composites and latent crimp-expressing polyester fibers using an eccentric core sheath composite have been studied.

For example, Patent Document 1 proposes a spontaneously crimpable composite fiber in which two types of aliphatic polyesters having different heat shrinkages are eccentrically composited in a single fiber. However, aliphatic polyester has low abrasion resistance, and in sportswear and the like, the fibers constituting the fabric are cut by rubbing during wearing, and fluffing and perforation occur. On the other hand, side-by-side type composite yarns and eccentric core sheath type composite yarns using polytrimethylene terephthalate (hereinafter referred to as PTT) and polybutylene terephthalate (hereinafter referred to as PBT) have abrasion resistance as compared with aliphatic polyester fibers. It is suitable because it is excellent in quality and can give appropriate elasticity to the fabric, and Patent Document 2 proposes a side-by-side type or eccentric core sheath type composite yarn of PTT and polyethylene terephthalate (hereinafter referred to as PET). It is true that excellent elasticity can be obtained by using a composite yarn of PTT and PET, and further, by using an eccentric core sheath type composite yarn in which the core component is PTT and the sheath component is PET, the abrasion resistance is remarkably improved.

Japanese Unexamined Patent Publication No. 9-209216 JP-A-2002-339169

Patent Document 2 reports a phenomenon in which the surface of a fabric is whitened when used under conditions such as sports outerwear where large abrasion may occur during use. From the morphological observation of the surface of the fabric with a scanning electron microscope (SEM), it was identified that this whitening phenomenon is caused by the peeling of the PTT / PET interface in the composite fibers constituting the fabric.

As described above, the known technology is insufficient to achieve both elasticity, abrasion resistance, and interfacial peeling resistance, and has excellent elasticity and excellent abrasion resistance and interfacial peeling resistance that can withstand severe scratches such as sports outerwear. A technology that balances sex has been long-awaited.

The present invention is a polyester-based composite having excellent elasticity and excellent abrasion resistance and interfacial peeling resistance that can withstand harsh usage conditions such as sports outerwear, and has latent crimping ability suitable for elastic woven fabrics. It proposes fibers.

In order to solve the above problems, the present invention has the following configuration.
(1) An aromatic polyester-based composite fiber which is a sea-island type composite fiber and whose cross-sectional shape satisfies the following requirements A to D.
A. When the composite fiber cross section is divided into two equal parts and a straight line is drawn that maximizes the area ratio of the island components contained in either of the two divided cross sections, 80 to 95% of the total island area is drawn on one half. Is included.
B. In the composite fiber cross section, the island: sea area ratio is in the range of 40:60 to 60:40.
C. The thinnest part of the thickness between the island and the outer circumference of the composite fiber is 3% or more of the radius of the composite fiber.
D. When the total area of the island is S, the total L of the island circumference satisfies L> (2πS) ^1/2 + (8S / π) ^1/2 .

(2) The aromatic polyester-based composite fiber according to (1), which is a sea-island type composite fiber composed of two components and is characterized by satisfying the requirements of E and F.
E. The main repeating structural unit of the island component polyester is trimethylene terephthalate or butylene terephthalate.
F. The main repeating structural unit of marine polyester is ethylene terephthalate.

(3) The aromatic polyester-based composite fiber according to (1) or (2), wherein the sea-island type composite fiber has two or more islands.

(4) The aromatic polyester-based composite fiber according to any one of (1) to (3), wherein the sea-island type composite fiber has a substantially circular shape with a flatness of 1.1 or less.

According to the present invention, it is possible to provide an aromatic polyester-based composite fiber having excellent abrasion resistance, interfacial peeling resistance, and excellent stretchability, and having a latent crimping ability suitable for stretchable woven fabrics.

(A) to (e) show an example of a single yarn cross-sectional shape of a composite fiber preferably used in the present invention. (F) to (j) show an example of the single yarn cross-sectional shape of the comparative example. The side view which shows an example of the silk reeling process (direct spinning drawing method) preferably used in this invention.

The present invention can be achieved by using an eccentric sea-island type composite fiber having a single yarn cross-sectional shape defined in detail in order to achieve both excellent stretchability, abrasion resistance, and interfacial peeling resistance. The eccentric sea-island type composite fiber in the present invention has a form as shown in FIGS. 1 (a) to 1 (e), and such a form causes crimping and excellent stretchability when made into a cloth. It can exhibit abrasion resistance and interfacial peeling resistance.

When the cross section of the eccentric sea-island type composite fiber is divided into two equal parts and a straight line is drawn to maximize the area ratio of the island components contained in either of the two divided cross sections, the total area of the island is halved on one side. 80-95% is included. If it is less than 80%, the eccentricity is insufficient, and the stretchability when made into a fabric is insufficient. Further, if it exceeds 95%, the eccentricity is too large, and a stable crimped form cannot be reproduced. More preferably, it is 85 to 90%.

The area ratio (island: sea) of the island component to the sea component in the cross section of the eccentric sea-island type composite fiber is 40:60 to 60:40, more preferably 45:55 to 55, in order to improve the crimping performance. : 45.

The island component is completely covered by the sea component. If the island component is exposed on the fiber surface, yarn breakage due to rubbing with each guide during the process when making eccentric sea-island type composite fibers or when making woven or knitted fabrics using eccentric sea-island type composite fibers. When used as a sports outer, fibrillation of fibers and interfacial peeling are likely to occur. Here, in the eccentric sea-island type composite fiber, the thinnest portion of the thickness between the island and the outer periphery of the composite fiber is 3% or more, more preferably 5% or more of the radius of the composite fiber.

In the cross section of the eccentric sea-island type composite fiber, when the total area of the islands is S, the total island circumference L satisfies L> (2πS) ^1/2 + (8S / π) ^1/2 . This parameter is a parameter that expresses the relationship between the circumference of the island and the area of the island. When there is one island and the shape of the island is a semicircle in the cross section of the composite fiber, L = (2πS) ^1/2 + ( 8S / π) ^1/2 . When L ≦ (2πS) ^1/2 + (8S / π) ^1/2 , the interface length between the sea component and the island component is insufficient, and under harsh use such as sports outerwear where strong abrasion may occur. The two components are separated at the interface in the composite fiber, and a whitening phenomenon is likely to occur.

By satisfying the above cross-sectional forms at the same time, it is possible to achieve both excellent stretchability and wear resistance that can withstand harsh conditions such as sports outerwear.

The composite fiber of the present invention is composed of aromatic polyester in order to achieve both stretchability and abrasion resistance. The aromatic polyester referred to here contains aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid as the main acid components, and ethylene glycol, 1,3-propanediol, 1,4-butylene glycol, and the like. It is a polyester containing at least one kind of glycol selected from the alkylene glycol components as a main glycol component. Further, a copolymerized polyester in which a third component other than the above is copolymerized can also be used. Examples of copolymerizable compounds include dicarboxylic acids such as isophthalic acid, succinic acid, cyclohexanedicarboxylic acid, adipic acid, dimaic acid, sebacic acid, and 5-sodium sulfoisophthalic acid, ethylene glycol, diethylene glycol, butanediol, and neopentyl glycol. , Cyclohexanedimethanol, polyethylene glycol, polypropylene glycol and other diols.

In the sea-island type composite fiber, the island component is preferably composed of PTT or polyester containing PBT as a main component. Further, the sea component is preferably made of polyester containing PET as a main component. By using an eccentric sea-island type composite fiber made of polyester containing PTT or PBT as the main component, it is possible to obtain a composite fiber that maximizes the softness and stretchability that are the characteristics of PTT and PBT. ..

The PTT referred to in the present invention is a polyester obtained by using terephthalic acid as a main acid component and 1,3-propanediol as a main glycol component. The PTT preferably comprises 90 mol% or more of a repeating unit of trimetine terephthalate.

Further, PBT is a polyester obtained by using terephthalic acid as a main acid component and 1,4-butanediol as a main glycol component. The PBT preferably comprises 90 mol% or more of the repeating unit of butylene terephthalate.

However, both PTT and PBT may contain other copolymerization components at a ratio of 10 mol% or less. Examples of copolymerizable compounds include dicarboxylic acids such as isophthalic acid, succinic acid, cyclohexanedicarboxylic acid, adipic acid, dimaic acid, sebacic acid, and 5-sodium sulfoisophthalic acid, ethylene glycol, diethylene glycol, butanediol, and neopentyl glycol. , Cyclohexanedimethanol, polyethylene glycol, polypropylene glycol and other diols. Further, if necessary, titanium dioxide may be added as a matting agent, silica fine particles as a lubricant, a hindered phenol derivative as an alumina fine particle antioxidant, a coloring pigment, or the like may be added.

PET is a polyester obtained by using terephthalic acid as a main acid component and ethylene glycol as a main glycol component. It is preferable that 90 mol% or more of PET is a repeating unit of ethylene terephthalate. Similar to PTT and PBT, it may contain the above-mentioned copolymerization component. Moreover, you may add an additive such as a matting agent.

In the sea-island type composite fiber, two or more islands are preferable. By increasing the number of islands, when compared with the same island area ratio, the interface length between the sea component and the island component becomes longer, so the interface peeling prevention effect becomes higher. It is more preferably 3 islands or more, and further preferably 4 islands or more. In order to maintain excellent stretchability, 20 islands or less is preferable, and 15 islands or less is more preferable.

As for the cross-sectional shape of the composite fiber, it is preferable that the outer peripheral shape of the composite fiber is substantially circular, and the flatness represented by A / B is 1.1 or less when the major axis of the outer peripheral shape is A and the minor axis is B. .. With such a shape, when an external tension is applied, the force can be uniformly dispersed and received, and the variation in the strength and elongation of the composite fiber in the SS curve is reduced, which is preferable.

The sea-island type composite fiber is preferably used with a single yarn fineness of 0.3 to 30 dtex and a total fineness of 10 to 1000 dtex. By lowering the total fineness and the single yarn fineness, the fabric can be made thinner and the color development and softness are improved, but the stretchability, especially the resilience when the fabric is stretched, is reduced, so the total fineness is reduced. More preferably, 10 to 100 dtex, single yarn fineness of 0.3 to 6.0 dtex, and the number of filaments are 10 to 100.

The strength is preferably 2.5 cN / dtex or more, and the toughness is preferably 15.0 or more. More preferably, the strength is 3.0 cN / dtex or more and the toughness is 20.0 or more. When the strength is 2.5 cN / dtex or more, the strength is high when it is made into a cloth, and it is suitable for thinning, increasing the density, and reducing the weight of the cloth for clothing. The upper limit of the strength is preferably 6.0 cN / dtex or less, and it is possible to suppress the generation of fluff due to the draw ratio being too high, and the process passability is improved. In addition, in order to increase the fiber strength, it is common to increase the draw ratio during manufacturing, but in this way, although the strength is increased, the elongation is decreased and fluff is likely to occur, and processes such as weaving Passability deteriorates. Therefore, in order to obtain high strength while maintaining sufficient elongation, the toughness is preferably 15.0 or more, and more preferably 20.0 or more. By using PET on the low-viscosity polymer side and optimizing the spinning temperature, the strength is increased and the toughness is improved. Therefore, the strength is more preferably 3.5 cN / dtex or more. There is a limit to the improvement of toughness by optimizing the yarn-making conditions, and it is preferably 27.0 or less that can be reached by general-purpose polyester.

The elongation is preferably 20 to 60%. By setting the elongation to 60% or less, the dimensional stability when a woven or knitted fabric is produced is excellent. By setting the elongation to 20% or more, the silk-reeling property and the fluff quality are improved, and further, the peeling of sea components is suppressed. It is more preferably 25 to 55%, still more preferably 25 to 45%.

The Worcester spot U%, which is an index of thickness unevenness in the fiber longitudinal direction, is preferably 1.8% or less, more preferably 1.2% or less in order to obtain a highly uniform fabric. When it is 1.8% or less, dyeing spots after dyeing can be suppressed, which is preferable. In the dyeing process, a large portion of the yarn spots has a small molecular orientation, so that a large amount of dye is absorbed, and if there are thick spots on the yarn, it causes dyeing spots and lowers the commercial value. More preferably, it is 1.2% or less.

The expansion / contraction rate of the composite fiber of the present invention is 40 to 90%. The higher the stretch / stretch rate, the higher the ability to develop crimps, and if it is 40% or more, comfortable stretch characteristics can be provided, which is preferable. Further, when the content is 90% or less, there is no wrinkle when the fabric is used, and the flatness and dimensional stability are improved, which is preferable. And more preferably 50 to 80%. The details of the method for measuring the expansion / contraction rate will be described later, but by suspending the same load as 0.0018 cN / dtex, which corresponds to the binding force in the cloth, on the fiber skein and heat-treating it, the crimping under the cloth restraint is performed. The expression ability can be expressed by the expansion / contraction rate of the fiber case.

A preferred silk reeling method for achieving the object of the present invention will be described.
As the mouthpiece used for the sea-island type composite fiber of the present invention, an existing composite mouthpiece can be used, but there are roughly three types of members: a measuring plate, a distribution plate, and a discharge plate described in Japanese Patent Application Laid-Open No. 2011-174215. It is preferable to use a composite base in which the above-mentioned components are laminated so that the cross-sectional form of the present invention in which the above-mentioned form is defined in detail can be stably obtained.

Examples of the melting method include a pressure melter method and an extruder method, but melting with an extruder is preferable from the viewpoint of efficiency and decomposition suppression. The melting temperature is preferably set to 10 to 40 ° C. higher than the melting point of the polymer used.
The preferred spinning temperature is 260-290 ° C. By adopting such a spinning temperature, it is possible to obtain a composite fiber having high toughness and good spinning performance. The intrinsic viscosity (IV) of each component used in the present invention is preferably higher on the island component side, and the island component IV is preferably 0.80 or more. More preferably, when it is 0.90 or more, toughness and stretchability can be easily obtained. From the viewpoint of productivity, it is preferably 2.00 or less, and more preferably 1.80 or less.

The sea component IV is preferably 0.40 or more, more preferably 0.45 or more and 0.80 or less.

When the IV difference between the high-viscosity island component and the low-viscosity sea component is 0.40 or more, good stretchability is exhibited, which is preferable. If the IV difference is 1.00 or less, it is preferable because it does not adversely affect the silk reeling property.

The content of the inorganic particles contained in the island component is preferably 3.0 wt% or less because the toughness and stretchability are improved, and more preferably 2.0 wt% or less.

It is preferable that the content of the inorganic fine particles contained in the sea component is 0.05 wt% or more because the process passability is improved. More preferably 0.10 wt% or more, still more preferably 0.20 wt% or more, and more preferably 3.0 wt% or less, more preferably 2.0 wt% or less without excessive wear of the guide during the process passage. Titanium oxide is preferable as the inorganic fine particles in terms of opacity, ease of handling, price, and various functions against sunlight.

The sea-island type composite fiber of the present invention includes a two-step method in which the discharged polymer is once wound as an undrawn yarn and then stretched, a direct spinning drawing method in which the spinning and drawing steps are continuously performed, a high-speed spinning method, and the like. Although it can be produced in any of the processes, from the viewpoint of uniformity and stretchability, it is preferable to adopt a one-step method in which the taken-up composite fiber is drawn by a heating roller without being wound once, heat-treated, and then wound. In the above one-step method, after refueling, it is continuously led to a stretching step without taking up and winding, leading to a first hot roller (1HR), stretching in one or two steps, and a second hot roller (2HR). ), Then wind up. At this time, the preferable spinning speed is 1100 m / min or more and 3000 m / min or less. By spinning at 3000 m / min or less, the spinning tension can be suppressed to 0.3 g / dtex or less, and the distortion of the fiber internal structure can be suppressed, which is preferable. The direct spinning and drawing method, in which the fiber is continuously drawn after being taken up, is preferable because the quality is stable, the variation in the strength and elongation in the fiber longitudinal direction can be suppressed, and the cost can be reduced by omitting the process.

The stretching temperature is preferably 50 ° C. or higher and 80 ° C. or lower, which is close to the glass transition temperature of the undrawn yarn. Uniform stretching can be achieved by setting the temperature to 50 ° C. or higher, and deterioration of operability due to fusion to the drawing roll or spontaneous elongation of the fiber can be prevented by setting the temperature to 80 ° C. or lower. Further, after drawing, the heat is preferably set at a temperature at which the crystal velocity of the undrawn yarn is maximized, preferably 130 ° C. or higher and 220 ° C. or lower. By heat setting, crystallization of fibers can be promoted, strength can be increased, and various yarn physical properties such as expansion / contraction rate, contraction stress, and boiling water shrinkage rate can be stabilized, which is preferable. Further, by setting the relaxation rate between the 2HR-3 Godet rollers (3GR) to 1.0 to 5.5%, the distortion of the polyester molecular amorphous portion caused by stretching can be alleviated, so that the effect of suppressing the tightening can be achieved. It is preferable because the effect of improving abrasion resistance, uniform thread physical properties, and stretchability can be obtained.

The heat-set yarn is wound by a winder, and the winding tension is preferably 0.02 g / dtex or more and 0.15 g / dtex or less. When wound around a package, it is preferable because it can reduce the difference between the inner and outer layers of the thread physical properties, reduce the saddle and bulge, and stabilize the expansion / contraction rate and the boiling water shrinkage rate.

As described above, the eccentric sea-island type composite fiber of the present invention has uniform physical properties, good productivity, is soft and has excellent stretchability, flatness, and dimensional stability when used as a fabric, and has no wrinkles. , Abrasion resistance and interfacial peeling resistance can be achieved for the first time by the manufacturing method of the extreme technology.

Hereinafter, examples will be specifically described. The main measured values of the examples were measured by the following methods.

(1) Intrinsic viscosity (IV)
For the ηr of the definition formula, 0.8 g of the sample polymer is dissolved in 10 mL of O-chlorophenol (OCP) having a purity of 98% or more, and the relative viscosity ηr is calculated by the following formula using an Ostwald viscometer at a temperature of 25 ° C. , The intrinsic viscosity (IV) was calculated.
ηr = η / η0 = (t × d) / (t0 × d0)
Intrinsic viscosity (IV) = 0.0242ηr + 0.2634
[Η: viscosity of polymer solution, η0: viscosity of OCP, t: fall time of solution (seconds), d: density of solution (g / cm ³ ), t0: fall time of OCP (seconds), d0: OCP Density (g / cm ³ ).

(2) Ratio of island area included in one half of the cross section of composite fiber, island: sea area ratio, thickness between island and composite fiber outer circumference to radius of composite fiber, total area of island and island circumference (sea-island interface length) ) Relationship The cross sections of the fibers obtained in each Example and Comparative Example were observed using a microscope VHX-2000 manufactured by Keyence Co., Ltd., and each value was measured with the attached image analysis software. Regarding the relationship between the island area and the island perimeter, if the island area S and the island perimeter L calculated by image analysis satisfy the following equation, it is evaluated as ◯, and if it does not satisfy, it is evaluated as ×.
(Relationship between total island area and island circumference) = L> (2πS) ^1/2 + (8S / π) ^1/2 .

(3) Cross-sectional flatness The cross-sections of the fibers obtained in each Example and Comparative Example were analyzed in the same manner as in (2) above, and the cross-sectional flatness was calculated according to the following formula.
(Flattening in cross section) = major axis A / minor axis B.

(4) Strength, Elongation, Toughness Measured according to JIS L1013 (2010, chemical fiber filament yarn test method). The toughness was calculated by the following formula.
(Toughness) = (Strength) x (Elongation) ^0.5 .

(5) Stretching / stretching ratio The stretching / stretching ratio was calculated according to JIS L1013 (2010), Section 8.11 C method (simple method).

(6) Worcester spot U%
Using USTER TESTER 4-CX manufactured by Zellweger, the measurement was performed in the normal mode while feeding the yarn at a speed of 200 m / min for 5 minutes.

(7) Operability Continuous spinning with a spinning volume of 5 tons was carried out three times, and the average number of yarn breaks per ton was calculated. The following evaluation points were used according to the number of thread breaks.
3 points: Number of thread breaks less than 1.0 times / ton 2 points: Number of thread breaks 1.0 times / ton or more, less than 2.0 times / ton 1 point: Number of thread breaks 2.0 times / ton or more 3. 0 times / ton less than 0 points: Thread breakage 3.0 times / ton or more.

(8) Abrasion resistance Using the fibers obtained in each Example and Comparative Example, a Zokki plain woven fabric machine was prepared with a warp density of 3580 fibers / m and a weft density of 3580 fibers / m, and cotton No. 6 canvas was used as a friction element. Evaluated according to JIS L1076 (2012, pilling test method for woven fabrics and knitted fabrics) 7.3 method (appearance retention method) except that the load was 1000 g and the measurement time / number of scrapes was 30 minutes / 2588 times. , Scored as follows.
3 points: Number of pills is about N in the standard photo 2 points: Number of pills is about L in the standard photo 1 point: Number of pills is about M in the standard photo 0 points: Of pills The number is about H in the standard photo or more than that.

(9) Interfacial peeling resistance The surface of the evaluated fabric obtained in (8) above was observed with a scanning electron microscope manufactured by KEYENCE CORPORATION, and the composite fibers constituting the fabric were observed in a field of view of 600 μm × 900 μm. The number of single yarns with peeled interfaces was counted to evaluate the peeling resistance.
3 points: 0 2 points: 1 to 10 1 point: 11 to 30 0 points: 31 or more.

(10) Quality of Stretchable Fabric The raw material obtained in the same manner as in (8) above was refined at 95 ° C., preset at 140 ° C., and then brushed. Then, it was dyed blue at 130 ° C. and finished set at 160 ° C. using a pin tenter to obtain a brushed fabric. The obtained brushed knitted fabric was cut into 1 m squares, and three evaluators with three years or more of experience compared one point of the woven fabric with the woven fabric using side-by-side yarn of PTT / PET of Comparative Example 3, and the evaluator 3 The following evaluation points were given by the discussion of the names.
3 points: Compared with the woven fabric using side-by-side yarn of Comparative Example 3, it has the same or better stretchability, flatness, and dimensional stability, and has good quality without wrinkles.
2 points: Compared with the woven fabric using side-by-side yarn of Comparative Example 3, the stretchability is slightly inferior, or the flatness of the fabric, the dimensional stability is slightly poor, and the quality is slightly inferior such as wrinkles.
1 point: Compared with the woven fabric using side-by-side yarn of Comparative Example 3, the stretchability is inferior, or the quality of the fabric is inferior such as flatness, poor dimensional stability, and large graining.
0 points: Not suitable for use as stretchable woven fabrics.

(11) Comprehensive evaluation The evaluation points of (7) to (10) above were added up, and pass / fail was judged according to the following criteria.
Pass: 10 points or more Fail: Less than 10 points Example 1
Homo PTT polymer (high viscosity component, melting point 225 ° C.) containing 0.30% by weight of titanium oxide and IV having an intrinsic viscosity (IV) of 1.10 and 0.51 IV containing 0.40% by weight of titanium oxide. Homo PET polyma (low viscosity component, melting point 255 ° C) is prepared, the high viscosity component is melted at 255 ° C in the extruder, the low viscosity component is melted at 285 ° C in the extruder, and the spinning temperature is 270. Set to ℃, weigh with a measuring pump, filter in the pack, and then use the base nozzle to make an eccentric sea-island composite type with a composite area ratio of 50:50 so that the cross-sectional shape is as shown in FIG. 1 (a). It was discharged.

The discharged polymer was fibrized by the silk reeling apparatus shown in FIG. That is, after cooling 2 and refueling 3, the product is picked up by a take-up roll (1st HR5) set at a speed of 1250 m / min and a surface temperature of 55 ° C., and is continuously taken up at 4200 m / min and 165 ° C. without being wound once. It was routed to a heat treatment roll (second HR6) set in 1 and stretched 3.4 times. The tension of the stretched and heat-treated yarn is adjusted by a godet roller (3rd GR7, 4th GR8) set at a speed of 4074 m / min, and a cheese-like package is formed at a speed of 4075 m / min with a tension of 0.15 g / dtex. It was wound to obtain an eccentric sea-island type polytrimethylene polyester composite fiber having 56 dtex-24 filaments. The evaluation results for the obtained fibers are shown in Table 1.

In Example 1, the strength and toughness were high, the stretch and stretch ratio was as good as 65%, the U% spots were small, and the operability was also good. As a result of subjecting the obtained raw yarn to weaving, the weaving yarn breakage was small, and the stretchability, quality, and texture of the fabric were good. Furthermore, when the abrasion resistance of the fabric was evaluated, the abrasion resistance of the fabric was high, and no whitening phenomenon occurred due to surface scraping or peeling of the sea-island component interface.

Examples 2-3, Comparative Example 1
Examples 2 and 3 conformed to Example 1 except that the island component polymers were changed as shown in Table 1.

In Example 2, the operability was slightly inferior to that in Example 1, but the physical properties of the raw yarn were at the same level. The stretchability of the fabric was higher than that of Example 1, and the fabric was slightly firm, but the abrasion resistance and interfacial peeling resistance were the same as those of Example 1.

In Example 3, physical properties such as strength and elongation and operability were good. Although the stretchability was slightly poor, the fabric had a firm feeling and was of good quality.

In Comparative Example 1, when polylactic acid (hereinafter referred to as PLA) was used for both components of Kaijima, wear resistance was low and interfacial peeling was confirmed. In addition, the stretchability was also insufficient.

Examples 4 to 7, Comparative Examples 2 to 6
The cross-sectional composite morphology of the Kaijima-type composite yarn was changed as shown in Table 2 to obtain composite fibers.

In Example 4 in which the base was designed so as to have a cross section as shown in FIG. 1 (b), a fabric having excellent stretchability and abrasion resistance was obtained as in Example 1.

In Example 5, composite fibers having a cross section as shown in FIG. 1 (c) were obtained. A fabric having less interfacial peeling and sufficient stretchability than in Example 1 was obtained.

In Example 6, by setting the number of islands to 5 as shown in FIG. 1 (d), the expansion / contraction rate of the raw yarn was slightly reduced, but by adjusting the 2HR-3GR stretch rate, the expansion / contraction of the pass level was achieved. When an elongation rate was obtained and the fabric was used, both stretchability and abrasion resistance were achieved.

In Example 7, a composite fiber having a cross section as shown in FIG. 1 (e) was obtained. The expansion / contraction rate decreased slightly, but it was at the passing level.

In Comparative Example 2, a side-by-side yarn as shown in FIG. 1 (f) was produced. By sticking to the side-by-side, the cross section was slightly flattened, so that the operability was lowered. Moreover, in the evaluation of the fabric, although the stretchability was high, the abrasion resistance and the interfacial peeling resistance were inferior.

In Comparative Example 3, an eccentric core sheath yarn having a core close to a perfect circle as shown in FIG. 1 (g) was produced. Since the expansion and contraction rate of the raw yarn is low and the interface length between PTT and PET is short, the result is that the interface peeling resistance is inferior.

In Comparative Example 4, an eccentric core sheath yarn having a semicircular core as shown in FIG. 1H was produced. Since the eccentricity is large, the expansion and contraction rate is high, and excellent stretchability is exhibited even when the fabric is used, but the interface length is insufficient with respect to the area of the core portion, so that interface peeling occurs.

In Comparative Example 5, an eccentric sea island yarn as shown in FIG. 1 (i) was produced. By changing the sea-island composite ratio and making it sea-rich, the silk-reeling property has improved and the toughness has improved. Although it has sufficient abrasion resistance and interfacial peeling resistance when it is used as a fabric, it has poor stretchability and is rejected.

Comparative Example 6 is an eccentric sea island thread of 30 islands as shown in FIG. 1 (j), and although interfacial peeling of the composite component is much less likely to occur, the island component is divided into a large number and packed, so that the island fusion Wearing and exposure of island components to the surface of the composite fiber occurred, and the operability was significantly reduced.

Examples 8-11, Comparative Examples 7-8
The sea-island composite ratio was changed as shown in Table 3, and the composite fibers were obtained by spinning in the same manner as in Example 1 except that the cross sections of Examples 8 and 9 and Comparative Example 7 were taken in FIG. 1 (a). Examples 10 and 11 and Comparative Example 8 had the cross section shown in FIG. 1 (d), and the yarn was spun in the same manner as in Example 1 except that the stretch ratio between 2HR and 3GR was 1.5% to obtain composite fibers.

In Example 8 in which the island: sea ratio was 45:55 and the sea was rich, the toughness was slightly reduced, but the operability was not a problem. Although the stretchability was slightly reduced, the distance between the island component and the outer circumference of the composite fiber was widened, so that the wear resistance was improved and the level was acceptable.

In Example 9 in which the island: sea ratio was 40:60 and the sea was rich, the toughness was reduced, but the operability was not a problem. Although the stretchability was reduced, there was no problem with wear resistance, and the interfacial peeling resistance was at the acceptable level.

In Example 10 in which the island: sea ratio was 55:45 and the island was rich, the distance between the island component and the outer circumference of the composite fiber was slightly narrowed, but the operability and abrasion resistance were sufficient, and the stretchability was also good. So, I passed.

In Example 11 in which the island: sea ratio was 60:40 and the island was further rich, the distance between the island component and the outer periphery of the composite fiber was further narrowed, and the operability and abrasion resistance were deteriorated, but the stretchability was observed. , The interface peeling resistance was good, and it passed.

In Comparative Example 7 in which the island: sea ratio was 35:65, the thick skin improved the operability and the abrasion resistance of the fabric, but was inferior in stretchability and failed.

In Comparative Example 8 in which the island: sea ratio was 65:35, the thin skin reduced the abrasion resistance to the guides in silk reeling and higher-order processing, and as a result, the abrasion resistance of the fabric was also improved. Due to the adverse effect, the stretchability was sufficient, but it was rejected.

Example 12, Comparative Example 9
In order to change the cross-sectional flatness of the Kaijima composite fiber, silk reeling was performed under the conditions according to Example 1 except that the discharge hole shape of the final plate of the base was changed to obtain a composite fiber. Table 3 shows the flattening, other conditions, and the evaluation results.

In Example 12, in which the cross section was slightly flattened, the operability was slightly lowered, but both good stretchability and wear resistance were achieved.

In Comparative Example 9 in which the cross section was further flattened, the operability was significantly reduced. Although the stretchability was high, the wear resistance was also reduced and the product was rejected.

Examples 13-14
A composite fiber was obtained by spinning under the conditions according to Example 1 except that the IV of the marine polymer was changed as shown in Table 3.

As the IV difference between the sea component polymer and the island component polymer became smaller, the stretch / elongation rate of the raw yarn and the stretchability when made into a cloth decreased, but both Examples 13 and 14 passed.

Examples 15-20
A composite fiber was obtained by spinning under the conditions according to Example 1 except that the titanium oxide content of the marine polymer was changed as shown in Table 4.

In Example 15, the fiber surface friction was high, the operability was slightly deteriorated, and the abrasion resistance was also lowered, but the results were acceptable.

In Example 16, the toughness of the raw yarn was slightly improved. The fiber surface friction was a little high, but the wear resistance was at the acceptable level without any problem.

In Example 17, good results were obtained in all of the raw yarn physical properties, stretchability, abrasion resistance, and interfacial peeling resistance.

In Examples 18 to 20, the operability deteriorated with time due to the exposure of titanium oxide to the fiber surface, but the abrasion resistance, the interfacial peeling resistance, and the quality of the stretchable fabric were not a problem and passed.

Example 21
Using the same polymer as in Example 1, the conditions were the same as in Example 1 until the fibers were discharged from the mouthpiece, and after cooling and refueling, the composite fibers were wound with a winder at a speed of 1250 m / min to obtain undrawn yarn. The obtained undrawn yarn was adjusted to a draw ratio of 31% at a hot roll of 65 ° C. and a hot plate of 155 ° C. using a known drawing machine, and drawn at a drawing speed of 800 m / min. A drawn yarn of 56 dtex / 24f was obtained. Compared with DSD, the obtained composite fiber had acceptable levels of abrasion resistance and stretchability of the fabric except that the operability was lowered.

Examples 22-24
A composite fiber was obtained by spinning under the conditions according to Example 1 except that the draw ratio was changed as shown in Table 5.

In Example 22, the elongation was high and the quality of the stretchable fabric was slightly lowered, but good results were obtained in all of operability, abrasion resistance, and interfacial peeling resistance. In Examples 23 and 24, the operability and wear resistance were deteriorated, but they were acceptable levels.

Examples 25-26
A composite fiber was obtained by spinning under the conditions according to Example 1 except that the relaxation rate between 2HR and 3GR was changed as shown in Table 5.

In Example 25, the operability was slightly lowered, but the stretchability was improved, and the wear resistance and the interfacial peeling resistance were also acceptable levels. In Example 26, the stretchability was slightly reduced, but it was a passing level.

1 Spinning cap 2 Thread cooling blower 3 Oil agent 4 Entanglement device 5 1st hot roller 6 2nd hot roller 7 Entanglement device 8 3rd godet roller 9 4th godet roller 10 Contact roller 11 Package

Claims (4)

An aromatic polyester-based composite fiber that is a sea-island type composite fiber and whose cross-sectional shape satisfies the following requirements (1) to (4).
(1) When the composite fiber cross section is divided into two equal parts and a straight line is drawn to maximize the area ratio of the island portion included in either of the two divided cross sections, 80 of the total island area is drawn on one half. Includes ~ 95%.
(2) In the cross section of the composite fiber, the area ratio of island: sea is in the range of 40:60 to 60:40.
(3) The thinnest portion between the island and the outer circumference of the composite fiber is 3% or more of the radius of the composite fiber.
(4) When the total area of the island is S, the total L of the island circumference satisfies L> (2πS) ^1/2 + (8S / π) ^1/2 . The aromatic polyester-based composite fiber according to claim 1, which is a sea-island type composite fiber composed of two components and satisfies the requirements of (5) and (6).
(5) The main repeating structural unit of the island component polyester is trimethylene terephthalate or butylene terephthalate.
(6) The main repeating structural unit of sea component polyester is ethylene terephthalate. The aromatic polyester-based composite fiber according to claim 1 or 2, wherein the sea-island type composite fiber has two or more islands. The aromatic polyester-based composite fiber according to any one of claims 1 to 3, wherein the sea-island type composite fiber has a substantially circular shape having a flatness of 1.1 or less.

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