TW202223184A - Sea-island-type composite fiber, and fiber product including sea-island-type composite fiber - Google Patents

Abstract

A fiber characterized by being a sea-island-type composite fiber in which the primary constituent component of the sea section is an aromatic polyester, the moisture absorption/desorption parameter [Delta]MR is at least 2.0%, and a diagram obtained by connecting the center of gravity of the islands positioned on the outermost periphery of the fiber cross-sectional surface with line segments is a regular polygon having the center of gravity as an apex. Provided is a polyester fiber having superior quality with no splitting of the fiber surface caused by dispersion of stress generated due to volume expansion of the fibers when absorbing moisture, no dyeing irregularity or fuzzing when used in a woven or knitted fabric, and no reduction in moisture absorption due to hot-water processing, etc.

Description

Sea-island composite fibers and fiber products containing sea-island composite fibers

The present invention relates to hygroscopic polyester fibers.

For example, polyester fibers represented by polyethylene terephthalate have excellent mechanical properties, chemical resistance, and heat resistance, and have a characteristic feel of tension and toughness. There are still few changes in characteristics, it is less prone to cracking, and has excellent dimensional stability, so it is widely used in clothing applications, industrial applications, and the like. However, as mentioned above, polyester fibers have no hygroscopicity, and especially in the high-temperature and high-humidity environment in summer, problems such as stuffiness and stickiness may occur. Therefore, it has been proposed to form a composite fiber with a hygroscopic polymer to impart hygroscopicity to the polyester fiber.

For example, a sea-island composite fiber having hygroscopicity proposed in Patent Document 1 has polyethylene terephthalate as the sea part and polyether block amide copolymer as the island part.

The sea-island composite fiber proposed in Patent Document 2 uses a hygroscopic polymer for the island portion to impart hygroscopicity to the fiber, and by controlling the thickness of the sea portion existing in the outermost layer of the fiber cross-section, it suppresses the occurrence of hot water treatment. of sea cracks. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2016-69770 [Patent Document 2] International Publication No. 2018/012318

(The problem that the invention intends to solve)

In the sea-island composite fibers disclosed in Patent Document 1 and Patent Document 2, the thickness of the sea portion and the number of island portions are specified regarding the arrangement of the island portions in the fiber cross section, but the single fiber fineness is changed in order to obtain a soft feel required for clothing applications. If it is fine, the stress generated by the volume swelling of the hygroscopic polymer during the hot water treatment cannot be dispersed, and cracks such as cracks may occur on the fiber surface. In this case, there is a possibility that the quality of knitted/knitted fabrics, etc. may be lowered due to uneven dyeing or hairiness. In addition, there is also a problem that the hygroscopic polymer is eluted due to cracks on the fiber surface, resulting in a decrease in hygroscopicity. In addition, in the case of such fibers, when the fibers or the textiles composed of them are worn, there is a possibility that the surface of the fibers is likely to be cracked, and when used in clothes such as underwear that are repeatedly washed, or sports clothes, etc. When rubbing the cloth, etc., there will be problems.

The reason is that the present invention aims to solve the above-mentioned problems, by dispersing the stress generated with the fiber volume swelling during moisture absorption, thereby greatly improving the occurrence of cracks on the fiber surface. Furthermore, it is an object to provide a polyester fiber which is excellent in quality without causing uneven dyeing, hairiness, etc. when forming a knitted/knitted fabric or the like, and which does not cause a decrease in hygroscopicity due to hot water treatment or the like. (Technical means to solve problems)

In order to solve the above-mentioned problems, the present invention has the following configuration. (1) A fiber, which is a sea-island type composite fiber in which the main component of the sea part is aromatic polyester, the moisture absorption and release parameter ΔMR is 2.0% or more, and the center of gravity of the island parts arranged at the outermost periphery in the cross section of the fiber is obtained by connecting by line segments , is a regular polygon with the center of gravity as the vertex. (2) The fiber according to (1), wherein the number of island portions arranged at the outermost periphery in the fiber cross-section is an odd number. (3) The fiber according to (1) or (2), wherein in the fiber cross section, the radius of curvature C (μm) of the edge on the fiber surface side arranged on the outer periphery of the outermost island portion is the same as that of the fiber cross section containing the fiber cross section. The ratio C/L of the radius L (μm) of the circumscribed circle arranged on the outermost island portion is 0.50 to 0.90. (4) A fiber product containing the sea-island type composite fiber of any one of (1) to (3). (Compared to the efficacy of the prior art)

According to the present invention, the stress generated by the volume swelling of the fiber during moisture absorption can be dispersed to suppress the cracking of the fiber surface, so that a knitted/knitted fabric can be formed without uneven dyeing, hairiness, etc., and an excellent quality polymer can be obtained. Ester fiber. In addition, since the hygroscopicity does not decrease, it has excellent hygroscopicity, and is particularly suitable for clothing applications.

The main component of the polyester fiber of the present invention is an aromatic polyester. Since the main component is an aromatic polyester, it is excellent in mechanical properties and heat resistance, so that it can have a good feel such as tension, toughness, and dryness. Furthermore, since the polyester fiber system of the present invention has an excellent moisture absorption property with a moisture absorption and release parameter ΔMR of 2.0% or more, a fiber structure excellent in wearing comfort when used as a cooling material can be obtained.

The hygroscopic fiber absorbs water molecules through physical adsorption of water molecules to the fibers and/or the interaction between the functional groups in the molecular structure of the fiber constituents and the water molecules. Especially in the case of high hygroscopicity, because water molecules will be absorbed into the fibers, the fibers will swell in volume. However, since aromatic polyesters have rigid aromatic rings in their macromolecular structure, they are not easily deformed, so that the stress generated when the volume swells due to moisture absorption is not easily dispersed, which may cause cracks on the fiber surface.

Here, the polyester fiber of the present invention, which suppresses the cracking of the fiber surface due to the volume swelling during moisture absorption, is mainly obtained by connecting the center of gravity of the components arranged in the outermost periphery of the components arranged inside the fiber in the cross section of the fiber by line segments. The figure is a regular polygon whose vertices are the center of gravity.

In the fiber cross section, the fiber cross-sectional shape having the components arranged inside the fiber is preferably a sea-island composite fiber composed of two or more kinds of polymers, and the component arranged inside the fiber belongs to the island portion. In the cross section of the fiber, the center of gravity of the components arranged inside the fiber is arranged at the outermost component, that is, the center of gravity of the island portion arranged at the outermost periphery in the cross section of the fiber, and the graph obtained by connecting by line segments is when the center of gravity of the island portions is connected by line segments , as shown in Fig. 1(a), the center of gravity is selected and drawn in such a way that the line segments do not intersect at places other than the center of gravity. On the other hand, as shown in Fig. 1(b), if the center of gravity of the island portion is connected by line segments, and the line segments intersect at a portion other than the center of gravity of the island portion, the figure drawn at this time is not included in the present invention. The center of gravity of the peripheral island is connected by a line segment in the obtained graph. Furthermore, as shown in FIG. 1( c ), in the island portion 2f, since other island portions (2a, 2b, 2c, 2d, and 2e) are arranged between the island portion and the fiber surface, the island portion 2f is not included in the fiber surface. The fiber cross section is arranged in the outermost island portion.

The definition of a regular polygon of an island component arrangement form, which is a feature of the present invention, will be described.

Regarding the figure obtained by connecting the centers of gravity of the island portions arranged at the outermost periphery in the fiber cross section by line segments, the figure consisting of n line segments is referred to as an n-angle, and the lengths of each line segment are referred to as A1, A2, A3...An. The average length of these line segments is set as Lx, and the ratio of the length of each line segment to the average value Lx (A1/Lx, A2/Lx, A3/Lx・・・An/Lx) is calculated, and the third decimal place is rounded off. When When both are in the range of 0.97 to 1.03, it means that the figure obtained by connecting the centers of gravity of the island portions arranged at the outermost periphery in the fiber cross-section by line segments is a regular n-angle.

The polyester fiber of the present invention is a figure obtained by connecting the center of gravity of the island parts arranged at the outermost periphery in the fiber cross section with line segments, which is a regular polygon with the center of gravity as the vertex, and the vector of the stress generated when the volume swells due to moisture absorption Adjacent island portions are completely opposite, so that the stress between the island portions is canceled, so that the stress propagating toward the sea portion of the fiber surface end can be reduced. Since the stress propagating toward the sea portion of the fiber surface is reduced, the fiber surface is less prone to cracking, and the occurrence of uneven dyeing and hairiness can be suppressed. On the other hand, when the graph obtained by connecting the centers of gravity of the islands arranged at the outermost periphery in the fiber cross section is not a regular polygon with the center of gravity as the vertex, the stress generated by the volume swelling during moisture absorption is not easily dispersed, and the Stress concentration points are likely to occur at the interface between the island and the sea. Therefore, cracks may occur on the fiber surface, uneven dyeing or hairiness may occur, and the quality of fabrics or knitted fabrics may be degraded.

As described above, the polyester fiber of the present invention can greatly improve the problem of the conventional composite fibers with hygroscopic components because the island components arranged at the outermost periphery are arranged in a regular polygon, and the island portions arranged at the outermost periphery in the fiber cross section can be greatly improved. The number is preferably an odd number.

By setting the number of islands arranged at the outermost periphery to an odd number, the linear concentration of stress generated by volume swelling due to moisture absorption can be suppressed, the stress can be dispersed, and the occurrence of cracks on the fiber surface can be suppressed. Therefore, uneven dyeing or generation of hairiness caused by cracks on the fiber surface can be suppressed, so that the knitted/knitted fabric can be formed with excellent quality. In the fiber cross section, the number of islands arranged at the outermost periphery is more preferably an odd number of 9 or less, particularly preferably an odd number of 5 or less, and the minimum number of islands is 3.

The total number of islands in the fiber cross-section of the polyester fiber of the present invention is preferably 15 or less. By setting the total number of island portions within this range, linear concentration of stress generated by volume swelling due to moisture absorption can be suppressed, stress can be dispersed, and cracks on the fiber surface can be suppressed. Therefore, uneven dyeing or generation of hairiness caused by cracks on the fiber surface can be suppressed, so that the knitted/knitted fabric can be formed with excellent quality. The number of islands in the fiber cross section is more preferably 10 or less, particularly preferably 6 or less, and the minimum number of islands is 3.

The polyester fiber of the present invention comprises the curvature radius C (μm) of the edge of the fiber surface side on the outer periphery of the island portion arranged at the outermost periphery in the fiber cross section, and the radius L ( μm) ratio C/L, preferably 0.50~0.90. Here, the circumscribed circle including the outermost island portion in the fiber cross section is the circle 4 in FIG. 2( b ), and the L is the radius of the circle 4 . In addition, the curvature radius C of the edge on the fiber surface side of the outer periphery of the island portion arranged at the outermost periphery in the fiber cross section is the radius of the circle 5 in Fig. 2(c) obtained by the method described in the examples. C/L represents the bending sharpness with respect to the fiber surface of the edge on the fiber surface side on the outer periphery of the island portion arranged at the outermost periphery in the fiber cross section. If the C/L is 0.50 or more, the stress generated by the volume swelling during moisture absorption will be uniformly dispersed in the sea, and the fiber surface will not be easily cracked. Better is 0.55 or higher, and extra-best is 0.60 or higher. In addition, if the C/L is 0.90 or less, the portion of the fiber surface side on the outer periphery of the outermost island portion in the fiber cross-section will not be bent too much, and an acute angle will not appear, so the volume during moisture absorption will not be too large. The stress generated by swelling will not be concentrated in these parts, so that the fiber surface will not crack. Better is 0.85 or less, and extra-best is 0.80 or less. In addition, C/L of 1.0 means that the edge on the fiber surface side of the outer periphery of the island portion arranged on the periphery is equal to the fiber surface curvature. A specific example of the fiber cross-section in this case is, for example, a core sheath with one island portion. composite fibers.

In the polyester fiber-based fiber of the present invention, the ratio L/R of the circumscribed circle radius L (μm) including all the islands arranged in the outermost periphery and the fiber radius R (μm) in the cross section is preferably 0.50 to 0.90. The L/R system represents the thickness of the sea portion between the fiber surface and the outermost island portion in the fiber cross section. When L/R is 0.90 or less, the thickness of the sea part can be sufficiently ensured relative to the fiber diameter, the sea part cracking caused by the stress generated by the volume swelling during moisture absorption can be suppressed, and the dyeing caused by the cracking of the fiber surface caused by the sea part cracking can be suppressed. Uneven or hairiness occurs, which can be excellent quality when knitted/knitted. Based on such an idea, the more preferable range is 0.80 or less, and the particularly preferable range is 0.60 or less. In addition, when the L/R ratio is 0.50 or more, the stiffness due to the thickness of the aromatic polyester arranged in the sea portion can be reduced, and the stress due to volume swelling during moisture absorption can be reduced.

In the polyester fiber of the present invention, the ratio S/ L, preferably 0.05~0.50. Here, the minimum distance between the island portion and the island portion in the cross-section of the fiber is obtained according to the method described in the examples, as shown in line segment 7 in FIG. 2(d).

Here, the minimum distance between the island portion and the island portion in the fiber cross section refers to the thickness of the sea portion sandwiched by two adjacent island portions. If the S/L is 0.05 or more, the stress generated by volume swelling during moisture absorption can be relieved by the sea between the island and the island, the propagation of stress to the sea can be reduced, and the occurrence of cracks on the fiber surface can be suppressed. Better is 0.10 or more, and extra-best is 0.15 or more. In addition, if the S/L is less than 0.50, since the distance between the island and the island is not separated, the stress relaxation effect caused by the sea between the island and the island can be exhibited, and the propagation of stress to the sea on the surface of the fiber can be reduced. Cracks on the fiber surface can be suppressed. Based on this idea, S/L is more preferably 0.40 or less, and particularly preferably 0.30 or less.

The minimum thickness of the sea portion of the polyester fiber of the present invention is preferably 0.3 μm or more.

The so-called minimum thickness of the sea here is based on the method described in the examples. When a straight line is drawn from the center of gravity of any island of the fiber cross-section toward the surface of any fiber, the distance between the intersection of the outer periphery of the island and the straight line, and the intersection of the fiber surface and the straight line is the smallest. which is the line segment 6 in Fig. 2(c). If the minimum thickness of the sea part is 0.3 μm or more, the sea part cracking caused by the stress generated by the volume swelling during moisture absorption can be suppressed, and the uneven dyeing or hairiness caused by the cracking of the fiber surface caused by the sea part cracking can be suppressed, so that the Excellent quality when formed into knitted/braided fabrics. More preferably, it is 1.0 μm or more, and particularly preferably 2.5 μm or more.

The composite ratio of sea part/island part of the polyester fiber of the present invention is preferably 50/50 to 90/10 according to weight. When the sea part compound ratio is 50% by weight or more, the sea part aromatic polyester is excellent in mechanical properties and heat resistance, and tension, toughness, and dry feeling can be obtained, and a fiber structure excellent in wearing comfort can be obtained. In addition, it can suppress sea cracks caused by stress generated by volume swelling during moisture absorption, and can suppress uneven dyeing or hairiness caused by fiber surface cracks caused by sea cracks. Excellent quality. The sea part compound ratio is more preferably 60% by weight or more, and particularly preferably 70% by weight or more. On the other hand, if the composite ratio of the sea part of the polyester fiber is 90% by weight or less, that is, if the composite ratio of the island part is 10% by weight or more, the rigidity caused by the thickness of the aromatic polyester arranged in the sea part can be reduced, and the absorption caused by the absorption can be reduced. Stress generated by volumetric swelling when wet. From such a thought, the sea part compound ratio is more preferably 85 wt % or less, and particularly preferably 80 wt % or less.

The hygroscopic parameter ΔMR of the hygroscopic index of the polyester fiber of the present invention is above 2.0%. ΔMR is the difference in fiber moisture absorption rate between the high temperature and high humidity represented by 30°C×90%RH and the standard temperature and humidity represented by 20°C×65%RH. The higher the ΔMR, the higher the fiber moisture absorption. . If the ΔMR is more than 2.0%, the feeling of stuffiness in the clothes is less, and the wearing comfort can be exhibited. A more preferable range of ΔMR is 2.5% or more, a particularly preferable range is 3.0% or more, and a further more preferable range is 4.0% or more. There is no particular upper limit to the ΔMR range, and the level that can be achieved in the present invention is about 10%, which is the substantial upper limit. In addition, the polyester fiber of the present invention satisfies the above-mentioned ΔMR range even before and after hot water treatment such as dyeing.

The aromatic polyester which is the main component of the polyester fiber of the present invention is composed of, for example, aromatic dicarboxylic acid and aliphatic diol, aliphatic dicarboxylic acid and aromatic diol, aromatic dicarboxylic acid and aromatic diol, etc. Combination of polymers. In general, it is preferable to use an aromatic polyester composed of a combination of an aromatic dicarboxylic acid and an aliphatic diol from the viewpoints of mechanical properties, heat resistance, and workability during production.

Specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, sodium isophthalic acid-5-sulfonate, lithium isophthalic acid-5-sulfonate, 5-(tetraalkyl)phosphoniumsulfoisophthalic acid, 4,4'-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, etc., but not limited thereto.

Specific examples of aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, hexanediol, cyclohexanediol, diethylene glycol, hexylene glycol, and neopentyl glycol. Diols, etc., but not limited to this.

The production method of the aromatic polyester of the present invention is not limited, and the raw materials at the time of production are collectively referred to as monomers, and the monomers can be synthesized and produced by a general polycondensation reaction, addition polymerization reaction, or the like. The single system can be, for example, a petroleum-derived monomer, a biomass-derived monomer, a mixture of a petroleum-derived monomer and a biomass-derived monomer, etc., but is not limited thereto.

Moreover, in the aromatic polyester of this invention, in the range which does not deviate from the objective of this invention, in addition to the main component, a 2nd, 3rd component may be copolymerized or mixed. Since the main constituent component is an aromatic polyester, the copolymerization amount is set so that the monomer amount of the copolymerization component is 10 mol % or less with respect to the total monomer amount.

The polyester fiber of the present invention is as described above, and the main component of the sea part is an aromatic polyester. However, in general, aromatic polyesters do not have functional groups or the like that strongly interact with water molecules in the polymer structure. Therefore, examples of methods for setting the ΔMR of the polyester fiber of the present invention to the above range include, for example, adding a hygroscopic compound, disposing a super hygroscopic polymer (hereinafter also referred to as a "hygroscopic polymer"), The polymer molecules on the fiber surface are treated with ozone or the like to generate hygroscopic functional groups and the like. Among these, in order to obtain a polyester fiber having excellent hygroscopicity, it is preferable to arrange a hygroscopic polymer in the island portion.

Preferred examples of the hygroscopic polymer suitable for the island portion of the polyester fiber of the present invention include, for example: polyetherester, polyetheramide, polyetheresteramide, polyamide, thermoplastic cellulose derivatives substances, polyvinylpyrrolidone, etc. Among these, from the viewpoints of excellent stability during melt molding and high target hygroscopicity, the polyester fiber of the present invention preferably uses polyetherester, polyetheramide, polyether containing polyether as a copolymerization component Ether ester amides, etc. In addition, since the polyetherester-based polyetherester has excellent affinity with the aromatic polyester of the sea and is also excellent in the heat resistance of the hygroscopic polymer, it also has the effect of improving the mechanical properties of the obtained sea-island composite fiber, which belongs to the present invention. Excellent user. Furthermore, from the viewpoint of suppressing the dissolution of the hygroscopic polymer into hot water, a polyetherester composed of polybutylene terephthalate excellent in crystallinity and a polyether is more preferable.

As mentioned above, the hygroscopic polymer has high affinity with water, and is easily eluted when it comes into contact with water or hot water during dyeing. If the fiber surface is cracked due to the stress generated by volume swelling during moisture absorption, the hygroscopic polymer in the island portion will come into contact with hot water and dissolve out of the fiber, resulting in a decrease in fiber hygroscopicity. Therefore, when the hygroscopic polymer is arranged in the island portion, the effect of suppressing cracks on the fiber surface by the composite cross-sectional shape of the polyester fiber of the present invention can be clearly exerted, and a polyester fiber with excellent hygroscopicity can be obtained.

In the hygroscopic polymer of the present invention, in addition to the main component, the second and third components may be copolymerized or mixed within the scope of not deviating from the purpose of the present invention. The monomer amount is 10 mol % or less with respect to the total monomer amount.

The cross-sectional shape of the polyester fiber of the present invention is not only a circular cross-section, but also various cross-sectional shapes such as flat, Y-shaped, T-shaped, hollow, field-shaped, and well-shaped.

The polyester fibers of the present invention may be in any form such as long fibers (filament) and short fibers (staple). In the case of long fibers, it may be a monofilament yarn composed of one monofilament, or a multifilament yarn composed of a plurality of monofilaments. In the case of short fibers, the cut length and the number of crimps are not limited.

The total fineness of the polyester fiber of the present invention may be appropriately set according to the application, and practically, it is preferably 8 dtex or more and 150 dtex or less in the case of long fibers for clothing. In addition, the strength is preferably 1.5 cN/dtex or more when used for clothing. If measures such as combining other fibers are used in the production of fabrics, it can be used without problems even if it is 1.5 cN/dtex or less. The elongation may be appropriately set according to the application, and from the viewpoint of workability when processing the fabric, it is preferably 25% or more and 60% or less.

The single fiber fineness of the polyester fiber of the present invention is preferably 6.0 dtex or less. By setting it within this range, the rigidity due to the thickness of the aromatic polyester disposed in the sea can be reduced, and the mechanical properties and heat resistance can be excellent, and the tension, toughness, and dry feeling can be obtained, and excellent wearing comfort can be obtained. fibrous structure. In addition, it can suppress sea cracks caused by stress generated by volume swelling during moisture absorption, and can suppress uneven dyeing or hairiness caused by fiber surface cracks caused by sea cracks, so that knitted/knitted fabrics can be formed. Excellent quality. The single fiber fineness is more preferably 4.0 dtex or less, and particularly preferably 2.0 dtex or less.

The polyester fiber of the present invention can be obtained by known methods such as melt spinning and composite spinning, and examples thereof are as follows. However, the spinning method and the compounding method are merely examples, and are not limited thereto.

The method for spinning the polyester fiber of the present invention composed of two or more kinds of polymers can be, for example, a melt spinning method for the purpose of producing long fibers, a solution spinning method such as a wet method and a wet-dry method, and a suitable method. The melt-spinning method is preferable from the viewpoint of improving productivity in the production by a melt-blown method, a spun-bond method, etc. for obtaining a sheet-like fiber structure. In addition, in the case of the melt spinning method, it is preferable to use a composite spinning nozzle which will be described later. In the case of the melt spinning method, the spinning temperature at this time is the temperature at which the main high-melting point or high-viscosity polymer exhibits fluidity among the polymer species to be used. The temperature of this fluidity varies depending on the molecular weight, but if it is set between the melting point of the polymer and the melting point +60°C, stable production can be achieved.

The production method by the melt spinning method is, for example, the sea part polymer and the island part polymer are melted separately, metered and transported by a gear pump, and in this state, a composite flow is formed in a specific composite structure by an ordinary method, Then it is spit out from the spinning nozzle, and the cooling air is blown out by a wire cooling device such as a chimney pipe, and the wire is cooled to room temperature. The roller is stretched according to the peripheral speed ratio of the pulling roller and the stretching roller at this time. Moreover, for example, the method of heat-setting a thread by a drawing roll and coiling it by a winder (winding device) can be used. In addition, for example, the peripheral speed of the pulling roller and the stretching roller are set to the same speed, and then the winding machine with the same speed is used to wind up the unstretched yarn first, and then execute the stretching method according to other steps.

In the polyester fiber of the present invention, by setting the melt viscosity ratio of the two or more polymers used in the sea part and the island part to be less than 5.0, a composite polymer flow can be stably formed, and a fiber with a good composite cross-section can be obtained , so it is better.

As the composite spinning nozzle used for producing the polyester fiber of the present invention, the composite spinning nozzle described in Japanese Patent Laid-Open No. 2011-208313 is preferably used. The composite spinning nozzle shown in FIG. 3 in this case is assembled in a spin pack in a state of stacking three types of members, such as a metering plate 8, a distribution plate 9, and a discharge plate 10, in order from the top, and is provided for spinning. FIG. 3 shows an example in which two types of polymers, A polymer and B polymer, are used. As mentioned above, it is difficult to control the shape of the island in the conventional composite spinning nozzle, and it is preferable to use a composite spinning nozzle utilizing a fine flow path as illustrated in FIG. 3 .

The spinning nozzle member shown in FIG. 3 has a measuring plate 8 that measures the amount of polymer in each discharge hole and each distribution hole and flows into it, uses the distribution plate 9 to control the composite cross-section of the single fiber cross-section and its cross-sectional shape, and then uses the discharge plate 10 to compress the The composite polymer flow formed by the distribution plate 9, and the role of spit.

In order to avoid the complicated description of the composite spinning nozzle, although it is not shown in the drawings, the members that are layered above the metering plate 8 can be used in conjunction with the spinning machine and the spinneret to form the flow path. By designing the metering plate 8 in accordance with the existing flow path components, the existing spinneret units and components can be directly utilized, so there is no need to specialize the spinning machine in order to match the spinning nozzle. In addition, a plurality of flow channel plates may be stacked between the flow channel and the measuring plate 8 or between the measuring plate 8 and the distribution plate 9 . Thereby, the flow path for transferring the polymer can be efficiently designed in the cross-sectional direction of the spinning nozzle and the cross-sectional direction of the single fiber, and the structure can be introduced into the distribution plate 9 . The composite polymer stream discharged from the discharge plate 10 is cooled and solidified in accordance with the above-mentioned production method, and then an oil is applied, and it is pulled by a roller having a predetermined peripheral speed to obtain fibers having a desired composite cross-section.

The polyester fiber of the present invention can be subjected to post-processing such as false twisting and twisting, and can be treated in the same manner as general fibers for weaving and knitting.

The polyester fibers and/or post-processed yarns of the present invention can be formed into fiber structures such as woven fabrics, knitted fabrics, fleece fabrics, non-woven fabrics, twisted yarns, batts and the like according to known methods. In addition, the fiber structure composed of the polyester fiber and/or the post-processed yarn of the present invention can be any knitted structure or woven structure, preferably, for example, plain weave, woven weave, satin weave or a variation of the same; As well as warp knitting, weft knitting, circular knitting, lace weave or variations of these, etc.

The polyester fiber of the present invention may be combined with other fibers by interlacing, interknitting, or the like when forming the fiber structure, or the fiber structure may be formed after forming a mixed fiber yarn with other fibers.

The fiber structure composed of the polyester fiber and/or the post-processed yarn of the present invention is suitable for applications requiring comfort and quality because of its excellent hygroscopicity. For example: general clothing use, sports clothing use, bedding use, interior decoration use, material use, etc., but not limited to these. [Example]

The present invention will be described in detail by using the embodiments, but the present invention is not limited to these embodiments. In addition, each characteristic value in an Example was measured using the following method.

A. Melt viscosity of polymer For a polymer sample with a moisture content of 300 ppm or less by a vacuum dryer, the sample was put into a heating furnace set to the same temperature as the spinning temperature using a capillary rheometer manufactured by Toyo Seiki, and placed in a nitrogen environment. The sample was melted down, the strain rate was changed stepwise, the sample was extruded from the capillary tube at the front end of the heating furnace, and the viscosity was measured. In addition, the measurement was started after the sample was held for 5 minutes after being put into the heating furnace, and the value at the shear rate of 1216 sec ⁻¹ was defined as the melt viscosity of the polymer.

B. Polymer melting point (Tm) Using a differential scanning calorimeter (DSC) Q2000 model manufactured by TA instruments, 20 mg of a polymer sample was heated from 20°C to 300°C at a heating rate of 20°C/min. After cooling from 300°C to 20°C in minutes, holding at 20°C for 1 minute, and then heating up from 20°C to 280°C at a heating rate of 20°C/minute, the peak top temperature of the observed endothermic peak was taken as the melting point. In addition, when a plurality of endothermic peaks were observed, the peak of the highest temperature endothermic peak was set as the melting point.

C. Total fineness The fiber sample was wound 200 times on a bobbin with a circumference of 1.125m to make a hank. After drying with a hot air dryer (105±2℃×60min), the weight of the hank was measured using a balance, and then multiplied by The value of the standard moisture regain is used to calculate the total denier. The measurement was performed 4 times, and the average value was taken as the total fineness.

D. Tensile strength and elongation The fiber sample was measured under the conditions of constant velocity elongation shown in the chemical fiber filament yarn testing method (JIS L1013 (2010)) using a measuring machine "TENSILON" (registered trademark) UCT-100 manufactured by ORIENTEC. The elongation is obtained from the elongation at the point where the maximum strength is exhibited in the tensile strength-elongation curve. In addition, the tensile strength is a value obtained by dividing the maximum strength by the total fineness as strength. The measurement was performed 10 times, and the average values were made into tensile strength and elongation.

E. Boiling water shrinkage rate The fiber sample was wound for 20 turns using a bobbin with a circumference of 1.125 m to produce a hank, and the initial length L ₀ was obtained under a load of 0.09 cN/dtex. Next, it air-dried after performing the process in boiling water for 30 minutes under no load. Next, obtain the length L ₁ after treatment under the load of 0.09cN/dtex, and calculate according to the formula (1): Boiling water shrinkage rate (%)=[(L ₀ -L ₁ )/L ₀ ]×100・・・(1)

F. ΔMR before hot water treatment A fiber sample or fabric sample of about 1 to 2 g was weighed into a weighing bottle, dried at 110° C. for 2 hours, and then the mass was measured, and the mass was defined as w ₀ . Next, after drying, the fiber sample was kept at a temperature of 20° C. and a relative humidity of 65% for 24 hours, and the mass was measured, and the mass was defined as w _65% . Next, the temperature was adjusted to 30° C. and the relative humidity was 90%, the fiber sample was held for 24 hours, and the mass was measured, and the mass was defined as w _90% . MR ₁ =[(w _65% -w ₀ )/w ₀ ]×100・・・(2) MR ₂ =[(w _90% -w ₀ )/w ₀ ]×100・・・(3) ΔMR= MR ₂ -MR ₁・・・(4) In this case, let the numerical value calculated from equations (2) to (4) be ΔMR.

G. ΔMR after hot water treatment As a fiber sample, a circular knitting machine NCR-BL (cylinder diameter 3.5 inches (8.9 cm), 27 gauge pressure) manufactured by Yingguang Industrial Co., Ltd. was used, and the stitches were adjusted to 50, and the original cylinder knitted fabric was produced. When the positive fineness of the fiber is less than 80dtex, according to the total fiber fineness of the yarn feeding to the tube knitting machine to be 80~160dtex, the plying yarn is appropriately implemented. When the total fineness exceeds 80dtex, one yarn is fed to the tube knitting machine. As above, adjust the stitches to 50 and make them. Next, the obtained tubular knitted original fabric was put into an aqueous solution containing 1 g/L of sodium carbonate and SANMOL BK-80, a surfactant manufactured by Nikka Chemical, and the aqueous solution was heated to 80°C and treated for 20 minutes, and then dried with hot air at 60°C. Dry in the machine for 60 minutes. Furthermore, after drying, the tube weave was subjected to hot water treatment under the conditions of a bath ratio of 1:100, a treatment temperature of 130°C, and a treatment time of 60 minutes, followed by drying in a 60°C hot air dryer for 60 minutes to obtain a tube fabric after the hot water treatment. original cloth. ΔMR was calculated according to the description in item F for the obtained hot-water treated original tubular fabric.

H. Radius of curvature C The fiber sample is embedded with an embedding agent such as epoxy resin, and an image of the fiber cross section in the vertical direction of the fiber axis is captured using a scanning electron microscope (SEM) manufactured by HITACHI at a magnification at which more than 10 single fibers can be observed. The obtained image was analyzed using WinROOF manufactured by Mitani Shoji, a computer software, and the radius of curvature C of the outer periphery disposed on the outermost island portion in the fiber cross-section on the side of the fiber surface was obtained.

When calculating the radius of curvature, first, referring to Fig. 2(c), draw a straight line from the center of gravity G of the island to any fiber surface, and then measure the line segment BF formed by the intersection point B between the outer circumference of the island and the straight line, and the intersection point F between the fiber surface and the straight line. Calculate the length to the second decimal place, and find the intersection point B where the length of the line segment BF becomes the minimum value. The island portion contacted from the intersection point B is in a circle circumscribing the island portion, and the radius that becomes the minimum value is obtained to the third decimal place. This operation is performed on all islands included in one single fiber, and this operation is performed on three randomly sampled single fibers, the average value of the obtained radii is calculated, and the value obtained by rounding off the third decimal place is set. is the radius of curvature C (μm).

I. Circumscribed circle radius L In the same way as item H, an image of the fiber cross-section was captured by SEM, and the captured image was analyzed using WinROOF. This operation was performed on 10 single fibers of , and a simple number average was obtained from the results, and the value rounded to the third decimal place was set as the circumscribed circle radius L (μm).

J. Fiber radius R In the same way as in item H, use SEM to take images of fiber cross-sections, and from each image taken, measure the radius of single fibers randomly sampled in the same image to the third decimal place in μm units, and apply the method to 10 randomly sampled single fibers. In this operation, a simple numerical average is obtained from the result, and the value rounded to the third decimal place is taken as the fiber radius R (μm). Here, when the cross section of the fiber in the direction perpendicular to the fiber axis is not a perfect circle, the area is measured, and the value obtained by converting to a circle is used.

K. Minimum distance S between island and island In the same manner as in item H, an image of the fiber cross-section was captured using SEM, and the captured image was analyzed using WinROOF to obtain the minimum distance S between the island portion and the island portion in the fiber cross-section.

When obtaining the minimum distance between the island portion and the island portion, referring to FIG. 2(d), in two adjacent island portions 2a and 2b, a straight line is drawn from the center of gravity Ga of the island portion 2a toward the island portion 2b, The intersection point of the outer periphery of the island portion was set as Da and Db, and the minimum value of the length of the line segment Da-Db was measured to the third decimal place. This operation is performed on two adjacent islands at 10 locations containing islands in a single fiber at random. In addition, when the number of line segments Da-Db formed between two adjacent island portions is less than 10, the minimum value of the line segment Da-Db is measured from all the island portions included in one single fiber. In addition, this operation is implemented for three single fibers randomly sampled, and the average length of the obtained line segments Da-Db is obtained, and the value rounded to the third decimal place is set as the minimum distance S ( μm).

L. Minimum thickness of sea In the same manner as in the method for obtaining the length of the line segment BF described in item H, referring to FIG. 2(c), draw a straight line from the center of gravity Ga of the island portion toward an arbitrary fiber surface, and measure the intersection point B between the outer periphery of the island portion and the straight line, and the intersection point between the fiber surface and the straight line. The length of the line segment BF formed by F reaches the second decimal place, and the intersection point B where the length of the line segment BF becomes the minimum value is obtained. This measurement is carried out on all the islands included in one single fiber and on three randomly sampled single fibers. The average value of the obtained line segment BF is calculated, and the value rounded to the second decimal place is set as the smallest sea part. Thickness (μm).

M. Number of sea cracks The barrel knitted fabric produced by the method described in item G and subjected to hot water treatment was evaporated using platinum-palladium alloy, and then observed at 1000 magnifications using a Hitachi Scanning Electron Microscope (SEM) S-4000 , 10 field of view microscope photos were taken randomly. In the 10 obtained photographs, the surface of the fibers constituting the original tubular knitted fabric was observed, and the cracks in the sea were counted. If the number of sea cracks is less than 10, it will be regarded as pass.

N. uneven staining According to the method described in item G, the original tubular knitted fabric was prepared, and the obtained tubular knitted original fabric was put into the aqueous solution containing 1 g/L of sodium carbonate and the surfactant SANMOL BK-80 made by Nikka Chemical, and the aqueous solution was heated to 80 °C and applied. After 20 minutes of treatment, drying was performed in a 60°C hot air dryer for 60 minutes. Next, dry heat setting was performed at 160° C. for 2 minutes, and the knitted original fabric after dry heat setting was put into Kayalon Polyester Blue UT-YA: 1.3% by weight of Nippon Kayaku Co., Ltd. with disperse dye added, and the pH was adjusted to 5.0 In the dyeing solution, or Kayacryl Blue 2RL-ED of Nippon Kayaku Co., Ltd. with cationic dye added: 1.0% by weight, and in the dyeing solution adjusted to pH 4.0, the liquor ratio is 1:100, the dyeing temperature is 130°C, and the dyeing time is 60 minutes. conditions for staining.

The dyed cylindrical fabric was used as a sample, and a spectrophotometer CM-3700d manufactured by Minolta was used, under D65 light source, a viewing angle of 10°, and the optical condition SCE (specular reflection light method excluded), for one sample, 3 measurements were performed. Next, the L value was measured, and the value rounded to the second decimal place of the average value was taken as the L value of the sample. This operation is performed on 10 samples randomly sampled, and the variation rate is obtained from the average value and standard deviation of the L values of the 10 samples. When the L value variation rate of the 10 samples was 5.0% or less, it was judged that there was no uneven dyeing.

O. Hairiness Using a multi-point hairiness counting device (MFC-120 manufactured by Toray Engineering Co., Ltd.), the fiber sample was moved at 600 m/min, and the hairiness number displayed on the counting device was measured at 10,000 meters. In addition, warping reed teeth (made of stainless steel, 1 mm interval between the reed teeth) were installed just before the measurement point, and fibers were allowed to pass therethrough. This measurement was repeated 10 times, and the average value of 10,000 meters was set as the number of hairs.

P. Water absorption and quick-drying properties will be produced according to the method described in item G, and applied to the original tube knitted fabric after hot water treatment. After maintaining at a temperature of 20 ° C and a relative humidity of 65% for 24 hours, set the mass and set the mass as w _a . Next, 0.3 ml of water was dropped at the center of the sample, the mass was measured, and the mass was defined as w _{0 minutes} . The moment when the water droplet fell on the sample was set as 0 minutes, the mass of the sample was measured at 5-minute intervals, and the mass was set as _{wn minutes} . Here, n points represents an arbitrary time for measuring the mass of the sample, and represents 5-minute intervals of 5 minutes, 10 minutes, and 15 minutes. The moisture residual rate WR at any time is calculated from the formula (5). WR=[(w _{0 minutes-} w _{n minutes} )/(w _{0 minutes-} w _a )]×100・・・(5) If the water residual rate WR calculated from the formula (5) is less than 30% of the time When it was 60 minutes or less, it was evaluated as having water-absorbing and quick-drying properties.

Q. Maintenance of hygroscopicity before and after hot water treatment From the ΔMR after hot water treatment calculated in item G, the difference in ΔMR between ΔMR before and after hot water treatment calculated in item F was subtracted to evaluate the change in fiber hygroscopicity before and after hot water treatment. If the change in ΔMR was 2.0% or less, it was judged that the fiber hygroscopicity was maintained before and after the hot water treatment.

(Example 1) Polyethylene terephthalate (melt viscosity: 120 Pa·s, melting point: 254°C) was set to Kaibe, and 50% by weight of polyethylene glycol (Sanyo Chemical Industry Co., Ltd. PEG6000S) with a number average molecular weight of 8300 g/mol was copolymerized. The polybutylene terephthalate (melt viscosity 50Pa·s, melting point 217°C) is set as the island portion, and at the spinning temperature of 285°C, after melting the polymers in the sea portion and the island portion, respectively, the weight according to the sea-island ratio The ratio is 80:20, and it flows into the spin pack assembled with the composite spinning nozzle shown in Fig. 3. According to the method of sea-island composite form, the number of islands arranged at the outermost periphery is 3 islands and the total number of islands is 3 islands. , and the inflowing polymer was discharged from the discharge holes (0.30 mm in diameter and 36 holes in the number of holes). The discharged composite polymer stream is cooled and solidified by a cooling device. After the water-containing oil is supplied from the oil supply device, the peripheral speed of the drawing roll of the first roll is 2000 m/min, the peripheral speed of the drawing roll of the second roll is 2000 m/min, and the winder The coiling speed was 2000 m/min, and the polyester fiber of 200dtex-36 unstretched yarn was obtained. Next, the undrawn yarn was stretched under the conditions of a first roll temperature of 90° C., a second roll temperature of 130° C., and a drawing ratio of 2.38 times represented by the ratio of the peripheral speeds of the first roll and the second roll, to obtain 84dtex-36 yarns. polyester fiber extension yarn. In the fiber cross section of the obtained polyester fiber, the ratios of the length of each line segment to the average value of the length of each line segment were 0.97, 1.03, and 0.99 for the triangle obtained by connecting the line segments at the center of gravity arranged at the outermost island portion. A figure obtained by connecting the center of gravity of the outermost island portion with a line segment is an equilateral triangle. Table 1 shows the evaluation results of the obtained polyester fibers.

(Example 2) Except that the sea part is made of 1.5 mol % of isophthalic acid-5-sulfonic acid sodium salt, and 1.0 wt % of polyethylene glycol (Sanyo Chemical Industry Co., Ltd. PEG1000) with a number average molecular weight of 1000 g/mol, and the polypara Except for ethylene phthalate (melt viscosity 170 Pa·s, melting point 244° C.), the same conditions as in Example 1 were followed to obtain a polyester fiber drawn yarn of 84dtex-36 yarn count. The ratios of the length of each line segment to the average value of the length of each line segment are 0.99, 1.02, and 0.99 for the triangle obtained by connecting the center of gravity arranged on the outermost island portion by line segments, and it was confirmed that the center of gravity arranged at the outermost peripheral island portion was obtained by connecting the line segments. The figure is an equilateral triangle. Table 1 shows the evaluation results of the obtained polyester fibers.

(Example 3) Except that the number of holes in the discharge holes was set to 72 holes, the undrawn yarn polyester fiber of 155dtex-72 filaments was obtained, and the obtained undrawn yarn was stretched according to the drawing ratio of 1.84 times, the rest were as in Example 2. Under the same conditions, a polyester fiber drawing yarn of 84dtex-72 filaments was obtained. The ratios of the length of each line segment to the average value of the length of each line segment were 0.99, 0.99, and 1.02 for the triangle obtained by connecting the center of gravity arranged on the outermost island portion by line segments, and it was confirmed that the center of gravity arranged at the outermost peripheral island portion was obtained by connecting the line segments. The figure is an equilateral triangle. Table 1 shows the evaluation results of the obtained polyester fibers.

(Example 4) Except that the number of holes in the discharge holes is set to 14 holes, the undrawn yarn polyester fiber of 258dtex-14 filaments is obtained, and the obtained undrawn yarn is stretched according to the drawing ratio of 3.07 times, the rest are as in Example 2 Under the same conditions, a polyester fiber drawing yarn of 84dtex-14 filaments was obtained. The ratios of the length of each line segment to the average value of the length of each line segment were 0.97, 1.00, and 1.03 for the triangle obtained by connecting the center of gravity arranged on the outermost island portion with line segments, and it was confirmed that the center of gravity arranged at the outermost island portion was obtained by connecting the line segment. The figure is an equilateral triangle. Table 1 shows the evaluation results of the obtained polyester fibers.

(Example 5) Except that the sea-island ratio was set to 50:50 according to the weight ratio, the other conditions were the same as those in Example 3 to obtain a stretched yarn of 84dtex-72 filament polyester fiber. The ratios of the length of each line segment to the average length of each line segment were 1.00, 0.99, and 1.01 for the triangle obtained by connecting the center of gravity arranged on the outermost island portion by line segments, and it was confirmed that the center of gravity arranged at the outermost peripheral island portion was obtained by connecting the line segments. The figure is an equilateral triangle. Table 1 shows the evaluation results of the obtained polyester fibers.

(Example 6) Except that the sea part was made of polyethylene terephthalate (melt viscosity 40 Pa·s, melting point 254°C), the same conditions as in Example 1 were followed to obtain a polyester fiber drawn yarn of 84dtex-36 yarn count . The ratios of the length of each line segment to the average length of each line segment were 0.98, 1.03, and 0.99 for the triangle obtained by connecting the center of gravity arranged on the outermost island portion by line segments, and it was confirmed that the center of gravity arranged at the outermost peripheral island portion was obtained by connecting the line segments. The figure is an equilateral triangle. Table 1 shows the evaluation results of the obtained polyester fibers.

(Example 7) The same conditions as in Example 3 were followed except that the sea part was made of polyethylene terephthalate (melt viscosity 40 Pa·s, melting point 254°C), and the sea-island ratio was set to 50:50 by weight , to obtain a polyester fiber extension yarn of 84dtex-72 filaments. The ratios of the length of each line segment to the average length of each line segment were 1.03, 1.01, and 0.97 for the triangle obtained by connecting the center of gravity arranged on the outermost island portion by line segments, and it was confirmed that the center of gravity arranged at the outermost peripheral island portion was obtained by connecting the line segments. The figure is an equilateral triangle. Table 1 shows the evaluation results of the obtained polyester fibers.

(Example 8) Except that the discharge hole is set to 0.23mm in diameter and the number of holes is 96 holes to obtain an unstretched polyester fiber of 115dtex-96 filaments, and the obtained unstretched yarn is stretched at a stretching ratio of 1.72 times. Under the same conditions as Example 3, a polyester fiber drawn yarn of 66dtex-96 counts was obtained. The ratio of the length of each line segment to the average value of the length of each line segment is 0.99, 1.01, and 0.99 for the triangle obtained by connecting the center of gravity arranged on the outermost island portion by line segments, and it was confirmed that the center of gravity arranged at the outermost peripheral island portion was obtained by connecting the line segments. The figure is an equilateral triangle. Table 1 shows the evaluation results of the obtained polyester fibers.

(Example 9) Except that the diameter of the discharge hole is set to 0.20mm and the number of holes is 144, the unstretched polyester fiber of 88dtex-144 filaments is obtained, and the obtained unstretched yarn is stretched according to the stretching ratio of 1.57 times. Under the same conditions as Example 3, a polyester fiber drawn yarn of 56dtex-144 filaments was obtained. The ratios of the length of each line segment to the average length of each line segment were 0.98, 1.03, and 0.99 for the triangle obtained by connecting the center of gravity arranged on the outermost island portion by line segments, and it was confirmed that the center of gravity arranged at the outermost peripheral island portion was obtained by connecting the line segments. The figure is an equilateral triangle. Table 2 shows the evaluation results of the obtained polyester fibers.

(Example 10) The polyethylene terephthalate (melt viscosity 68 Pa·s, melting point 251°C) copolymerized with 16% by weight of polyethylene glycol (Sanyo Chemical Industry Co., Ltd. PEG6000S) having a number-average molecular weight of 8300 g/mol was set as Kaibe , and set polyethylene terephthalate (melt viscosity 120 Pa·s, melting point 254°C) as the island portion, at a spinning temperature of 285°C, after melting the polymers in the sea portion and the island portion, respectively, the sea-island ratio The weight ratio is measured in a 90:10 manner, and it flows into the spinneret assembly assembled by the composite spinning nozzle shown in Figure 3. According to the number of islands arranged at the outermost periphery, the number of islands is 3 and the total number of islands is 3 islands. Morphologically, the inflowing polymer was discharged from the discharge holes (0.30 mm in diameter, 36 holes in the number of holes). The discharged composite polymer stream is cooled and solidified by a cooling device. After the water-containing oil is supplied from the oil supply device, the peripheral speed of the drawing roll of the first roll is 2000 m/min, the peripheral speed of the drawing roll of the second roll is 2000 m/min, and the winder The winding speed was 2000 m/min, and the polyester fiber of 215dtex-36 unstretched yarn was obtained. Next, the undrawn yarn was stretched under the conditions of a first roll temperature of 90° C., a second roll temperature of 130° C., and a drawing ratio of 2.48 times represented by the ratio of the peripheral speeds of the first roll and the second roll to obtain 84dtex-36 yarns. polyester fiber extension yarn. The ratios of the length of each line segment to the average value of the length of each line segment are 0.98, 1.02, and 0.99 for the triangle obtained by connecting the center of gravity arranged on the outermost island portion by line segments, and it was confirmed that the center of gravity arranged at the outermost peripheral island portion was obtained by connecting the line segments. The figure is an equilateral triangle. Table 2 shows the evaluation results of the obtained polyester fibers.

(Example 11) Polyterephthalate copolymerized with 1.5 mol % of isophthalic acid-5-sulfonic acid sodium salt and 1.0 wt % of polyethylene glycol (Sanyo Chemical Industry Co., Ltd. PEG1000) having a number average molecular weight of 1000 g/mol in Kaibu Ethylene formate (melt viscosity 170Pa·s, melting point 244℃). Next, 20% by weight of polyvinylpyrrolidone ("Luviskol" K30SP, K value=30, manufactured by BASF Corporation) was added to polycaprolactam without additives to prepare polycaprolactam master batch chips. Next, the above-mentioned master batch chips were blended with polycaprolactam (sulfuric acid relative viscosity: 2.71, melting point: 220°C) without additives to prepare polycaprolactam with a polyvinylpyrrolidone addition rate of 5.0% by weight. A polymer was blended, and the polymer blend (melt viscosity 130 Pa·s, melting point 220° C.) was set as an island portion. The same conditions as in Example 2 were followed except that the polymers of the sea part and the island part were formed into the above-mentioned combination, and the sea-island ratio was set to 50:50 by weight, and the polyester fiber extension of 84dtex-36 filaments was obtained. yarn. The ratios of the length of each line segment to the average value of the length of each line segment are 0.98, 1.02, and 0.99 for the triangle obtained by connecting the center of gravity arranged on the outermost island portion by line segments, and it was confirmed that the center of gravity arranged at the outermost peripheral island portion was obtained by connecting the line segments. The figure is an equilateral triangle. Table 2 shows the evaluation results of the obtained polyester fibers.

(Example 12) A polyester fiber drawn yarn of 84dtex-36 counts was obtained under the same conditions as in Example 2, except that the island was made of "PEBAX MH1657" (melt viscosity 45 Pa·s, melting point 203°C) manufactured by ARKEMA. The ratios of the length of each line segment to the average value of the length of each line segment were 1.01, 1.01, and 0.98 for the triangle obtained by connecting the center of gravity arranged on the outermost island portion by line segments, and it was confirmed that the center of gravity arranged at the outermost peripheral island portion was obtained by connecting the line segments. The figure is an equilateral triangle. Table 2 shows the evaluation results of the obtained polyester fibers.

(Example 13) In addition to flowing into the spinneret assembly of the composite spinning nozzle as shown in Figure 3, according to the method of forming a sea-island composite form with five islands arranged at the outermost periphery and a total number of islands six islands, the discharge holes (diameter 0.30 mm) , the number of holes is 72 holes), except that the polymer was discharged and flowed into the polymer, the rest were in accordance with the same conditions as Example 3 to obtain a polyester fiber stretched yarn of 84dtex-72 filaments. In the fiber cross-section of the obtained polyester fiber, the ratios of the length of each line segment to the average value of the length of each line segment are 1.01, 1.00, 0.98, 0.99, 1.02 for a pentagon obtained by connecting the center of gravity arranged at the outermost island portion with line segments, It was confirmed that the figure obtained by connecting the centers of gravity arranged at the outermost island portions by line segments is a regular pentagon. Table 2 shows the evaluation results of the obtained polyester fibers.

(Example 14) In addition to flowing into the spinneret assembly of the composite spinning nozzle assembly shown in Fig. 3, according to the method of forming a sea-island composite form with 9 islands arranged at the outermost periphery and a total of 12 islands, from the discharge hole (diameter 0.30 mm) , the number of holes is 36 holes), except that the polymer is discharged and inflowed, the rest are in accordance with the same conditions as in Example 2, to obtain a polyester fiber stretched yarn of 84dtex-36 filaments. In the fiber cross section of the obtained polyester fiber, the ratios of the length of each line segment to the average value of the length of each line segment were 1.03, 1.01, 0.98, 0.99, 1.00 for a nonagonal shape obtained by connecting the segments with the center of gravity arranged at the outermost island portion. , 1.00, 0.98, 0.99, and 1.02, and it was confirmed that the figure obtained by connecting the center of gravity arranged at the outermost island portion with a line segment is a regular nonagon. Table 2 shows the evaluation results of the obtained polyester fibers.

(Example 15) Except that the sea-island ratio was set to 65:35 according to the weight ratio, the same conditions as in Example 2 were followed to obtain a polyester fiber drawn yarn of 84dtex-36 filaments. The ratios of the length of each line segment to the average value of the length of each line segment are 1.01, 0.98, and 1.01 for the triangle obtained by connecting the center of gravity arranged on the outermost island portion by line segments, and it was confirmed that the center of gravity arranged at the outermost peripheral island portion was obtained by connecting the line segments. The figure is an equilateral triangle. Table 2 shows the evaluation results of the obtained polyester fibers.

[Table 1] [Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Kaibe polymer species PET SIPA-PET SIPA-PET SIPA-PET SIPA-PET PET PET SIPA-PET Melt viscosity (Pa･s) 120 170 170 170 170 40 40 170 Shimabe polymer species PBT-PEG PBT-PEG PBT-PEG PBT-PEG PBT-PEG PBT-PEG PBT-PEG PBT-PEG Melt viscosity (Pa･s) 50 50 50 50 50 50 50 50 Spinning thread Melt viscosity ratio of sea part and island part 2.4 3.4 3.4 3.4 3.4 0.8 0.8 3.4 Island Compound Ratio 80/20 80/20 80/20 80/20 50/50 80/20 50/50 80/20 elongation ratio 2.38 2.38 1.84 3.07 1.84 2.38 1.84 1.72 fiber cross section A figure formed by the center of gravity of the outermost island equilateral triangle equilateral triangle equilateral triangle equilateral triangle equilateral triangle equilateral triangle equilateral triangle equilateral triangle Number of outermost islands 3 3 3 3 3 3 3 3 total number of islands 3 3 3 3 3 3 3 3 The curvature radius C (µm) of the outermost island 3.08 2.66 4.29 2.98 3.45 3.70 1.85 Circumscribed circle radius L (µm) of the outermost island 3.79 3.83 2.83 6.18 4.11 3.83 4.11 3.60 Fiber radius R(µm) 7.30 7.30 5.19 11.77 5.19 7.30 5.19 3.98 Shortest distance between islands S(µm) 0.56 0.62 0.82 1.00 0.82 0.62 0.82 0.63 Minimum thickness of sea (µm) 3.51 3.47 2.36 5.59 1.08 3.47 1.08 0.38 C/L 0.81 0.69 #VALUE! 0.69 0.73 0.90 0.90 0.51 L/R 0.52 0.52 0.55 0.53 0.79 0.52 0.79 0.90 S/L 0.15 0.16 0.29 0.16 0.20 0.16 0.20 0.18 Fiber properties Fineness (dtex) 84 84 84 84 84 84 84 66 Single fiber fineness (dtex) 2.3 2.3 1.2 6.0 1.2 2.3 1.2 0.7 Strength (cN/dtex) 2.6 2.7 2.2 3.1 1.4 2.2 1.3 1.8 Elongation(%) 43 42 42 43 43 40 42 42 ΔMR(%) before hot water treatment 4.1 4.2 4.2 3.2 9.5 4.1 9.3 4.0 ΔMR(%) after hot water treatment 3.7 4.0 4.0 3.1 8.3 3.3 7.3 3.7 ΔMR change due to hot water treatment (%) -0.4 -0.2 -0.2 -0.1 -1.2 -0.8 -2.0 -0.3 Evaluation Number of sea cracks (pieces) 2 0 1 0 6 5 8 4 uneven staining 1.3 0.9 1.1 0.8 2.4 2.1 3.8 2.3 Hairiness (pieces/m) 2 0 2 0 3 3 7 6 Drying speed(min) 50 50 45 50 60 55 60 45 PET: polyethylene terephthalate SPIA-PET: 5-sulfoisophthalic acid copolymerized polyethylene terephthalate PET-PEG: polyethylene glycol copolymer polyethylene terephthalate PBT-PEG: polyethylene glycol copolymer polybutylene terephthalate PVP: Polyvinylpyrrolidone

[Table 2] [Table 2] Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Example 15 Kaibe polymer species SIPA-PET PET-PEG SIPA-PET SIPA-PET SIPA-PET SIPA-PET SIPA-PET Melt viscosity (Pa･s) 170 68 170 170 170 170 170 Shimabe polymer species PBT-PEG PET N6+PVP PEBAX PBT-PEG PBT-PEG PBT-PEG Melt viscosity (Pa･s) 50 120 130 45 50 50 50 Spinning thread Melt viscosity ratio of sea part and island part 3.4 0.6 1.3 3.8 3.4 3.4 3.4 Island Compound Ratio 80/20 90/10 50/50 80/20 80/20 80/20 65/35 elongation ratio 1.57 2.48 2.38 2.38 1.84 2.38 2.38 fiber cross section A figure formed by the center of gravity of the outermost island equilateral triangle equilateral triangle equilateral triangle equilateral triangle regular pentagon Regular Nine equilateral triangle Number of outermost islands 3 3 3 3 5 9 3 total number of islands 3 3 3 3 6 12 3 The curvature radius C (µm) of the outermost island 1.35 2.34 4.13 2.66 2.04 2.20 3.73 Circumscribed circle radius L (µm) of the outermost island 2.70 3.71 5.98 3.83 2.87 3.98 5.08 Fiber radius R(µm) 3.00 7.30 7.30 7.30 5.19 7.30 7.30 Shortest distance between islands S(µm) 0.47 0.97 0.86 0.64 0.57 0.43 0.41 Minimum thickness of sea (µm) 0.30 3.59 1.32 3.47 2.32 3.32 2.22 C/L 0.50 0.63 0.69 0.69 0.71 0.55 0.73 L/R 0.90 0.51 0.82 0.52 0.55 0.55 0.70 S/L 0.17 0.26 0.14 0.17 0.20 0.11 0.08 Fiber properties Fineness (dtex) 56 84 84 84 84 84 84 Single fiber fineness (dtex) 0.4 2.3 2.3 2.3 1.2 2.3 2.3 Strength (cN/dtex) 1.6 2.9 3.2 2.7 2.3 2.7 1.6 Elongation(%) 44 37 44 44 41 44 41 ΔMR(%) before hot water treatment 3.8 3.2 2.2 4.0 4.1 3.6 6.8 ΔMR(%) after hot water treatment 3.5 2.7 2.0 3.4 3.6 3.1 5.7 ΔMR change due to hot water treatment (%) -0.3 -0.5 -0.2 -0.6 -0.5 -0.5 -1.1 Evaluation Number of sea cracks (pieces) 0 1 2 5 2 2 5 uneven staining 0.9 1.2 1.1 2 1.4 1.6 1.4 Hairiness (pieces/m) 1 0 0 5 3 2 3 Drying speed(min) 40 60 45 55 50 50 50 PET: polyethylene terephthalate SPIA-PET: 5-sulfoisophthalic acid copolymerized polyethylene terephthalate PET-PEG: polyethylene glycol copolymer polyethylene terephthalate PBT-PEG: polyethylene glycol copolymer polybutylene terephthalate PVP: Polyvinylpyrrolidone

(Comparative Example 1) Polyethylene terephthalate (melt viscosity: 120 Pa·s, melting point: 254°C) was set as Haibe, and 50% by weight of polyethylene glycol (Sanyo Chemical Industry Co., Ltd. PEG6000S) with a number-average molecular weight of 8300 g/mol was used for co-polymerization. The polymerized polybutylene terephthalate (melt viscosity 50Pa·s, melting point 217°C) was set as the island portion, and at the spinning temperature of 285°C, after melting the polymers in the sea portion and the island portion, respectively, the ratio of The weight ratio is 80:20, and it flows into the spinneret assembly assembled by the composite spinning nozzle shown in Figure 3. According to the number of islands arranged at the outermost periphery, the number of islands is 1 island and the total number of islands is 1 island. Morphologically, the inflowing polymer was discharged from the discharge holes (0.30 mm in diameter, 36 holes in the number of holes). The discharged composite polymer stream is cooled and solidified by a cooling device. After the water-containing oil is supplied from the oil supply device, the peripheral speed of the drawing roll of the first roll is 2000 m/min, the peripheral speed of the drawing roll of the second roll is 2000 m/min, and the winder The coiling speed was 2000 m/min, and the polyester fiber of 200dtex-36 unstretched yarn was obtained. Next, the undrawn yarn was stretched under the conditions of a first roll temperature of 90° C., a second roll temperature of 130° C., and a drawing ratio of 2.38 times represented by the ratio of the peripheral speeds of the first roll and the second roll, to obtain 84dtex-36 yarns. polyester fiber extension yarn. In the fiber cross section of the obtained polyester fiber, since the total number of island portions is one, it is impossible to obtain a pattern connected by line segments from the center of gravity arranged on the outermost island portion. Therefore, the obtained polyester fiber may occur during moisture absorption. The sea is cracked, and uneven dyeing or hairiness occurs when fabric is formed. In addition, the polymer in the island part was eluted from the cracked part of the sea part, and the hygroscopicity after the hot water treatment was also poor. Table 3 shows the evaluation results of the obtained polyester fibers.

(Comparative Example 2) Under the same conditions as Example 1, except that the sea part was made of polyethylene terephthalate (melt viscosity 500 Pa·s, melting point 254°C), a polyester fiber drawing yarn of 84dtex-36 counts was obtained . The ratios of the lengths of each line segment to the average value of the lengths of each line segment are 1.10, 1.04, and 0.86 for the triangle obtained by connecting the barycenters arranged in the outermost peripheral island with line segments, because the The figure is not an equilateral triangle, and the obtained polyester fiber has sea cracks when it absorbs moisture, and uneven dyeing or hairiness occurs when fabric is formed. In addition, the polymer in the island part was eluted from the cracked part of the sea part, and the hygroscopicity after the hot water treatment was also poor. Table 3 shows the evaluation results of the obtained polyester fibers.

(Comparative Example 3) Except that the sea-island ratio was set to 40:60 according to the weight ratio, the same conditions as in Example 1 were followed to obtain a polyester fiber drawn yarn of 84dtex-36 filaments. The ratios of the lengths of each line segment to the average value of the lengths of each line segment are 1.09, 0.96, and 0.95 for the triangle obtained by connecting the barycenters arranged in the outermost peripheral island with line segments, because the The figure is not an equilateral triangle, and the obtained polyester fiber has sea cracks when it absorbs moisture, and uneven dyeing or hairiness occurs when fabric is formed. In addition, since the amount of polyethylene terephthalate in the sea part is relatively small, the water absorption and quick-drying properties are poor. Table 3 shows the evaluation results of the obtained polyester fibers.

(Comparative Example 4) The same procedure as in Example 2 was carried out, except that the number of holes in the discharge holes was set to 10 to obtain an undrawn yarn polyester fiber of 270dtex-10 counts, and the undrawn yarn was drawn at a draw ratio of 3.21 times. Condition, the polyester fiber stretched yarn of 84dtex-10 filaments was obtained. The ratios of the length of each line segment to the average length of each line segment were 0.98, 1.02, and 1.00 for the triangle obtained by connecting the center of gravity arranged on the outermost island portion by line segments, and it was confirmed that the center of gravity arranged at the outermost peripheral island portion was obtained by connecting the line segments. The figure is a regular triangle, but because the sea part is thicker, the moisture absorption and release properties are poor, and because the single fiber is thicker and the fiber is rigid, the hand feeling of the obtained fabric is also poor. Table 3 shows the evaluation results of the obtained polyester fibers.

[table 3] [table 3] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Kaibe polymer species PET PET PET SIPA-PET Melt viscosity (Pa･s) 120 500 120 170 Shimabe polymer species PBT-PEG PBT-PEG PBT-PEG PBT-PEG Melt viscosity (Pa･s) 50 50 50 50 Spinning thread Melt viscosity ratio of sea part and island part 2.4 10.0 2.4 3.4 Island Compound Ratio 80/20 80/20 40/60 80/20 elongation ratio 2.38 2.38 2.38 3.21 fiber cross section A figure formed by the center of gravity of the outermost island none triangle triangle equilateral triangle Number of outermost islands 1 3 3 3 total number of islands 1 3 3 3 The curvature radius C (µm) of the outermost island 3.40 1.53 2.84 6.00 Circumscribed circle radius L (µm) of the outermost island 3.40 4.31 6.11 8.65 Fiber radius R(µm) 7.30 7.30 7.30 16.48 Shortest distance between islands S(µm) 0.00 0.30 0.41 1.30 Minimum thickness of sea (µm) 3.90 2.99 1.19 7.83 C/L 1.00 0.35 0.46 0.69 L/R 0.47 0.59 0.84 0.52 S/L 0.00 0.07 0.07 0.15 Fiber properties Fineness (dtex) 84 84 84 84 Single fiber fineness (dtex) 2.3 2.3 2.3 8.4 Strength (cN/dtex) 2.7 1.5 1.1 3.5 Elongation(%) 42 42 43 43 ΔMR(%) before hot water treatment 4.0 3.8 12.1 1.9 ΔMR(%) after hot water treatment 1.9 1.7 9.3 1.8 ΔMR change due to hot water treatment (%) -2.1 -2.1 -2.8 -0.1 Evaluation Number of sea cracks (pieces) 15 11 18 1 uneven staining 5.1 6.8 7.3 1.1 Hairiness (pieces/m) 16 12 19 0 Drying speed(min) 45 50 70 45 PET: polyethylene terephthalate SPIA-PET: 5-sulfoisophthalic acid copolymerized polyethylene terephthalate PBT-PEG: polyethylene glycol copolymer polybutylene terephthalate (Industrial Availability)

The polyester fiber of the present invention can disperse the stress generated by the volume swelling of the fiber during moisture absorption, and suppress the occurrence of cracks on the fiber surface, so that uneven dyeing or hairiness does not occur when forming a knitted/knitted fabric, and the quality is excellent. In addition, since the hygroscopicity is not lowered, it has excellent hygroscopicity, and is particularly suitable for clothing applications.

1: Haibe 2a, 2b, 2c, 2d, 2e, 2f: Island 3a, 3b, 3c: The fiber cross section is arranged in the outermost island portion, and the connecting line segment between any two straight line intersections (centers of gravity) divided into two equal parts of the island portion area of the adjacent island portion 4: All islands arranged in the outermost periphery of the fiber cross section, and are circumscribed by two or more perfect circles (circumscribed circles) 5: A perfect circle (circle circumscribed) circumscribed by 1 island at 2 or more points 6: The minimum thickness of the sea 7: Minimum distance between island and island 8: Metering board 9: Distribution board 10: Spit out board B: Draw a straight line from the intersection (center of gravity) of any two straight lines dividing the area of the island into two equal parts to the surface of any fiber, and the intersection with the outer periphery of the island Da, Db: Draw a straight line from the intersection (center of gravity) of any two straight lines dividing the area of the island into two equal parts to any adjacent island, and the intersection with the outer periphery of the island F: Draw a line from the intersection (center of gravity) of any two straight lines dividing the area of the island into two equal parts to the surface of any fiber, and the point of intersection with the surface of the fiber Ga, Gb, Gc, Gd, Ge: Intersection point (center of gravity) of any two straight lines dividing the area of the island into two equal parts

Fig. 1 is a schematic diagram (a), (b), (c) of the cross-sectional structure of the polyester fiber of the present invention. Fig. 2 is a schematic diagram (a), (b), (c), (d) of the cross-sectional structure of the polyester fiber of the present invention. Fig. 3 is a cross-sectional view for explaining the production method of the polyester fiber of the present invention.

1: Haibe

2a, 2b, 2c: Island

3a, 3b, 3c: The fiber cross section is arranged in the outermost island portion, and the connecting line segment between any two straight line intersections (centers of gravity) divided into two equal parts of the island portion area of the adjacent island portion

4: All islands arranged in the outermost periphery of the fiber cross section, and are circumscribed by two or more perfect circles (circumscribed circles)

5: A perfect circle (circle circumscribed) circumscribed by 1 island at 2 or more points

6: The minimum thickness of the sea

7: Minimum distance between island and island

B: Draw a straight line from the intersection (center of gravity) of any two straight lines dividing the area of the island into two equal parts to the surface of any fiber, and the intersection with the outer periphery of the island

Da, Db: Draw a straight line from the intersection (center of gravity) of any two straight lines dividing the area of the island into two equal parts to any adjacent island, and the intersection with the outer periphery of the island

F: Draw a line from the intersection (center of gravity) of any two straight lines dividing the area of the island into two equal parts to the surface of any fiber, and the point of intersection with the surface of the fiber

Ga, Gb, Gc: Intersection point (center of gravity) of any two straight lines dividing the area of the island into two equal parts

Claims (4)

A fiber, which is a sea-island type composite fiber in which the main component of the sea part is aromatic polyester, the moisture absorption and release parameter ΔMR is 2.0% or more, and the center of gravity of the island parts arranged at the outermost periphery in the cross section of the fiber is a figure obtained by connecting with line segments, A regular polygon with the center of gravity as its vertices. The fiber according to claim 1, wherein the number of islands arranged at the outermost periphery in the cross section of the fiber is an odd number. The fiber according to claim 1 or 2, wherein the radius of curvature C (μm) of the edge of the fiber surface side on the outer periphery of the island portion arranged in the outermost periphery in the fiber cross section is equal to the radius of curvature C (μm) of the fiber surface portion arranged in the outermost island portion in the fiber cross section. The ratio of the circumscribed circle radius L (μm), C/L, is 0.50~0.90. A fiber product containing the sea-island type composite fiber of any one of claims 1 to 3.

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