Fibers and methods for producing the same, fiber structures, and clothing

Abstract

The present invention provides a fiber containing syndiotactic polystyrene that exhibits dyeability with disperse dyes and shrinkage at high temperatures equivalent to those of polyester fibers. [Solution] The fiber is characterized by containing a mixture of syndiotactic polystyrene A and atactic polystyrene B, wherein the amount of atactic polystyrene B is 15 to 50 parts by mass per 100 parts by mass of the total of syndiotactic polystyrene A and atactic polystyrene B, wherein the crystallite size D(110) in the (110) plane determined by X-ray diffraction is greater than 0 Å and 75 Å or less, and the crystallite size D(002) in the (002) plane is 75 Å or more and 110 Å or less.

Description

Technical Field

[0001] The present invention relates to fibers containing a mixture of syndiotactic polystyrene and atactic polystyrene, a method for producing the same, a fiber structure containing the fibers, and clothing containing the fiber structure.

Background Art

[0002] Synthetic fibers typified by polyester fibers and nylon fibers have excellent properties such as mechanical properties and wrinkle resistance, and are widely used in various fields such as clothing applications, interior applications, and industrial applications. In particular, polyester fibers are excellent in durability, heat resistance, etc., and are widely used in clothing applications.

[0003] On the other hand, in recent years, syndiotactic polystyrene has attracted attention as a fiber material excellent in quick drying property, water repellency, and light weight in order to further improve performance and impart functionality. For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 9-111567) discloses a composite spun yarn in which synthetic fiber multifilaments and a short fiber group are mixed, and the synthetic fiber multifilaments are composed of syndiotactic polystyrene fibers, and the boiling water shrinkage rate of the syndiotactic polystyrene fibers is 5% or less, the crystallinity is 30% or more, and the initial modulus is 80 g / d or more. A high modulus composite spun yarn is disclosed.

[0004] Further, Patent Document 2 (Japanese Patent Application Laid-Open No. 2016-121283) discloses a molded body containing 100 to ① mass% of syndiotactic polystyrene into which a functional group is introduced and 0 to 99 mass% of a thermoplastic resin, and describes manufacturing a fiber as the molded body.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] However, fibers containing syndiotactic polystyrene (syndiotactic polystyrene fibers) have a problem in that they have poor dyeability. Although syndiotactic polystyrene fibers can be dyed using disperse dyes, just like polyester fibers, they tend to have lower dyeability than polyester fibers. For example, when syndiotactic polystyrene fibers are mixed with polyester fibers, if disperse dyes are used for dyeing, the disperse dyes preferentially dye the polyester fibers, resulting in insufficient dyeability of the syndiotactic polystyrene fibers. Therefore, it is necessary to make the dyeability equivalent to that of polyester fibers. In addition, since the dyeing of polyester fibers is carried out under high temperature conditions, it is necessary to make the shrinkage of syndiotactic polystyrene fibers under high temperature conditions equivalent to that of polyester fibers, in order to facilitate the design of fiber structures containing these fibers.

[0007] Patent Document 1 describes that the boiling water shrinkage rate can be reduced by increasing the crystallinity of syndiotactic polystyrene fibers, and that composite spun yarns, which are a mixture of syndiotactic polystyrene fibers and short fibers such as polyester fibers, can be dyed with disperse dyes. However, the syndiotactic polystyrene fibers described are fibers obtained by spinning syndiotactic polystyrene alone, and the specific degree of dyeability is not described.

[0008] Patent Document 2 describes how introducing functional groups into syndiotactic polystyrene facilitates dyeing with dyes, but it does not describe anything about dyeability with disperse dyes, nor does it describe its relationship with polyester fibers.

[0009] Therefore, the present invention aims to solve the above problems and to provide a fiber containing syndiotactic polystyrene that has dyeability with disperse dyes and shrinkage at high temperatures equivalent to polyester fibers. [Means for solving the problem]

[0010] The inventors of the present invention, through diligent research to achieve the above objective, discovered that a fiber containing a mixture of syndiotactic polystyrene and atactic polystyrene in a specific content exhibits dyeability and boiling water shrinkage rate equivalent to polyester fibers by having a specific crystallite size, thus completing the present invention.

[0011] In other words, the present invention may be configured in the following embodiments. [Aspect 1] A fiber characterized by containing a mixture of syndiotactic polystyrene A and atactic polystyrene B, wherein the content of atactic polystyrene B is 15 to 50 parts by mass (preferably 18 to 40 parts by mass, more preferably 20 to 35 parts by mass, even more preferably 20 to 30 parts by mass) per 100 parts by mass of the total of syndiotactic polystyrene A and atactic polystyrene B, wherein the crystallite size D(110) in the (110) plane determined by X-ray diffraction is greater than 0 Å and 75 Å or less (preferably 1 Å to 74 Å, more preferably 10 Å to 73 Å, even more preferably 15 Å to 73 Å, and even more preferably 20 Å to 73 Å), and the crystallite size D(002) in the (002) plane is 75 Å to 110 Å (preferably 75 Å to 105 Å, more preferably 78 Å to 105 Å, even more preferably 80 Å to 100 Å). [Aspect 2] A fiber according to Embodiment 1, wherein the single filament fineness is 1.0 dtex or more and 5.0 dtex or less (preferably 1.5 dtex or more and 4.8 dtex or less, more preferably 2.0 dtex or more and 4.5 dtex or less). [Aspect 3] A fiber according to embodiment 1 or 2, wherein the degree of Hermann orientation in the equatorial direction is 0.00 or more and 0.40 or less (preferably 0.10 or more and 0.38 or less, more preferably 0.20 or more and 0.35 or less, even more preferably 0.25 or more and 0.35 or less, and even more preferably 0.28 or more and 0.33 or less). [Aspect 4] A fiber according to any one of embodiments 1 to 3, wherein the degree of crystallinity is 25% or more and 40% or less (preferably 27% or more and 39% or less, more preferably 29% or more and 38% or less, and even more preferably 32% or more and 37% or less). [Aspect 5] A fiber according to any one of embodiments 1 to 4, wherein the elongation is 10% or more and 50% or less (preferably 10% or more and 40% or less, more preferably 11% or more and 30% or less). [Aspect 6] A fiber according to any one embodiment of embodiments 1 to 5, wherein the boiling water shrinkage rate is 3.0% or more and 20.0% or less (preferably 3.5% or more and 18.0% or less, more preferably 3.8% or more and 15.0% or less, and even more preferably 4.0% or more and 10.0% or less). [Aspect 7] A fibrous structure containing the fibers described in any one of embodiments 1 to 6. [Aspect 8] A fiber structure according to embodiment 7, further comprising polyester fibers. [Aspect 9] Clothing comprising the textile structure described in embodiment 7 or 8. [Effects of the Invention]

[0012] The fibers of the present invention have dyeability with disperse dyes and boiling water shrinkage rates equivalent to those of polyester fibers, and can be suitably used in fiber structures mixed with polyester fibers. [Modes for carrying out the invention]

[0013] [fiber] The fiber of the present invention (hereinafter sometimes referred to as syndiotactic polystyrene-based fiber) contains syndiotactic polystyrene A and atactic polystyrene B, and the content of the atactic polystyrene B is 15 to 50 parts by mass with respect to a total of 100 parts by mass of the syndiotactic polystyrene A and the atactic polystyrene B. The fiber is characterized by including a mixture, and the crystallite size D(110) in the (110) plane determined by X-ray diffraction is greater than 0 Å and 75 Å or less, and the crystallite size D(002) in the (002) plane is 75 Å or more and 110 Å or less. Syndiotactic polystyrene has high crystallinity, and the amorphous part capable of dyeing with disperse dyes is less than that of polyester. Therefore, the fiber containing syndiotactic polystyrene has lower dyeability with disperse dyes than polyester-based fibers. In the present invention, by mixing a specific amount of atactic polystyrene with syndiotactic polystyrene, the crystallinity of syndiotactic polystyrene is reduced, and the crystallite sizes in the fiber axis direction and the direction perpendicular to the fiber axis are adjusted to specific ranges, respectively. While improving the dyeability with disperse dyes, it has been found that an increase in the boiling water shrinkage rate due to an increase in the proportion of the amorphous part can be suppressed.

[0014] (Syndiotactic polystyrene A) Syndiotactic polystyrene A is a styrene-based polymer having a highly syndiotactic structure. In this specification, the syndiotactic structure means a three-dimensional structure in which substituents of side chains of adjacent constitutional units are alternately arranged (hereinafter referred to as syndiotacticity) with respect to the plane formed by the main chain of the polymer. Specifically, syndiotactic polystyrene A has a stereoregularity (tacticity) of 75 mol% or more of racemic diad (r) as a highly syndiotactic structure. The stereoregularity is determined by nuclear magnetic resonance method using isotope carbon ( 13By the 13C-NMR method, the configuration of a plurality of consecutive constitutional units can be identified and the proportion of their existence can be quantified. The configuration of two adjacent constitutional units can be identified as a dyad. A configuration in which the substituents of the side chains are arranged in different directions with respect to the plane of the main chain is identified as a racemic dyad (r), and a configuration in which they are arranged in the same direction is identified as a meso dyad (m). The higher the proportion of the racemic dyad (r), the more highly syndiotactic the structure is. Syndiotactic polystyrene A preferably has a racemic dyad (r) of 85 mol% or more. Also, as the pentad of the configuration of five consecutive constitutional units, syndiotactic polystyrene A may have a racemic pentad (rrrr) of 30 mol% or more, preferably 50 mol% or more.

[0015] The styrenic polymer may be polystyrene and its derivatives. Examples thereof include polystyrene, poly(alkylstyrene), poly(halogenated styrene), poly(halogenated alkylstyrene), poly(alkoxystyrene), poly(vinyl benzoate), and their hydrogenated polymers, and copolymers containing these constitutional units as the main component (for example, 50 mol% or more in all constitutional units).

[0016] Examples of poly(alkylstyrene) include poly(methylstyrene), poly(ethylstyrene), poly(isopropylstyrene), poly(t-butylstyrene), poly(phenylstyrene), poly(vinyl naphthalene), poly(vinylstyrene), and the like. Examples of poly(halogenated styrene) include poly(chlorostyrene), poly(bromostyrene), poly(fluorostyrene), and the like. Examples of poly(halogenated alkylstyrene) include poly(chloromethylstyrene), and the like. Examples of poly(alkoxystyrene) include poly(methoxystyrene), poly(ethoxystyrene), and the like.

[0017] Examples of comonomer components of copolymers containing these constituent units include, in addition to the monomers of the styrene polymers mentioned above, olefin monomers such as ethylene, propylene, butene, hexene, and octene; diene monomers such as butadiene and isoprene; cyclic olefin monomers; cyclic diene monomers; and polar vinyl monomers such as methyl methacrylate, maleic anhydride, and acrylonitrile.

[0018] Among these styrene-based polymers, preferred examples include polystyrene, poly(p-methylstyrene), poly(m-methylstyrene), poly(p- or t-butylstyrene), poly(p-chlorostyrene), poly(m-chlorostyrene), poly(p-fluorostyrene), hydrogenated polystyrene, and copolymers containing these constituent units as main components, with polystyrene being more preferred. The styrene-based polymers of syndiotactic polystyrene A may be used individually or in combination of two or more types.

[0019] Syndiotactic polystyrene A may have a weight-average molecular weight of 300,000 or less, preferably 10,000 to 300,000, more preferably 50,000 to 250,000, even more preferably 100,000 to 200,000, and even more preferably 120,000 to 170,000. In this specification, the weight-average molecular weight can be measured by gel permeation chromatography (GPC) and is the value measured by the method described in the examples below.

[0020] Syndiotactic polystyrene A may have a melt flow rate (MFR) of, for example, 8 g / 10 min to 80 g / 10 min under conditions of a temperature of 300 °C and a load of 1.2 kg, preferably 10 g / 10 min to 70 g / 10 min, and more preferably 12 g / 10 min to 65 g / 10 min. In this specification, the MFR is a value measured in accordance with JIS K 7210-1:2014.

[0021] Syndiotactic polystyrene A can be produced according to known methods, for example, by polymerizing styrene monomers (monomers corresponding to the above-mentioned styrene polymers) using a titanium compound and a condensation product of water and trialkylaluminum (aluminoxane) as catalysts in or in the absence of an inert hydrocarbon solvent.

[0022] (Attack Polystyrene B) Atactic polystyrene B is an amorphous styrene-based polymer. Atactic polystyrene B does not have a regular stereostructure and therefore does not have a crystalline structure. The styrene-based polymer of atactic polystyrene B may be the styrene-based polymer described above as syndiotactic polystyrene A. Atactic polystyrene B preferably contains 90 mol% or more of styrene-derived structural units and / or structural units derived from styrene derivatives having substituents on the benzene ring, and more preferably 95 mol% or more of these. Examples of styrene derivatives having substituents on the benzene ring include alkylstyrene (e.g., methylstyrene, ethylstyrene, isopropylstyrene, t-butylstyrene, phenylstyrene, vinylnaphthalene, vinylstyrene, etc.), halogenated styrene (e.g., chlorostyrene, bromostyrene, fluorostyrene, etc.), halogenated alkylstyrene (e.g., chloromethylstyrene, etc.), alkoxystyrene (e.g., methoxystyrene, ethoxystyrene, etc.), vinyl benzoic acid esters, etc. From the viewpoint of compatibility with syndiotactic polystyrene A, atactic polystyrene B is preferably a styrene-based polymer of the same type as the styrene-based polymer of syndiotactic polystyrene B, and more preferably polystyrene together with syndiotactic polystyrene A. Atactic polystyrene B can be produced according to known methods.

[0023] Atactic polystyrene B may have a melt flow rate (MFR) under conditions of a temperature of 200°C and a load of 5 kg, for example, 0.1 g / 10 min to 20 g / 10 min, preferably 0.5 g / 10 min to 15 g / 10 min, more preferably 1.0 g / 10 min to 12 g / 10 min, and even more preferably 1.5 g / 10 min to 9 g / 10 min.

[0024] Syndiotactic polystyrene fibers include a mixture containing the above-mentioned syndiotactic polystyrene A and atactic polystyrene B. When a fiber contains a mixture of syndiotactic polystyrene A and atactic polystyrene B, it means that it is a mixed spun fiber obtained by spinning a mixture containing these, rather than a composite spun fiber obtained by simultaneously spinning syndiotactic polystyrene A and atactic polystyrene B from a separated spindle. In this specification, syndiotactic polystyrene fibers are any fiber that contains a mixture containing syndiotactic polystyrene A and atactic polystyrene B, and the inside of the fiber may consist only of the mixture, or the inside of the fiber may have a composite cross-section (a cross-section perpendicular to the fiber axis) of the mixture and other components. In this specification, components such as oils attached to the surface of the fiber do not fall under the category of components inside the fiber, as they are not distributed inside the fiber.

[0025] In the mixture of syndiotactic polystyrene fibers, the content of atactic polystyrene B is 15 to 50 parts by mass, preferably 18 to 40 parts by mass, more preferably 20 to 35 parts by mass, and even more preferably 20 to 30 parts by mass, based on 100 parts by mass of the total of syndiotactic polystyrene A and atactic polystyrene B. The content of syndiotactic polystyrene A may be 50 to 85 parts by mass, preferably 60 to 82 parts by mass, more preferably 65 to 80 parts by mass, and even more preferably 70 to 80 parts by mass, based on 100 parts by mass of the total of syndiotactic polystyrene A and atactic polystyrene B.

[0026] The mixture in the syndiotactic polystyrene fiber may contain other components besides syndiotactic polystyrene A and atactic polystyrene B, to the extent that they do not impair the effects of the present invention. Examples of other components include thermoplastic resins different from syndiotactic polystyrene A and atactic polystyrene B, and various additives. Other thermoplastic resins that can be used as components include, for example, styrene polymers that do not fall under either syndiotactic polystyrene A or atactic polystyrene B, such as isotactic polystyrene, AS resin, ABS resin, and styrene-vinyl polydiene block copolymers (SBS, SEP, SEPS, SEB, SEBS, etc.); polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resins such as polyethylene, polypropylene, polybutene, polymethylpentene, and ethylene-propylene copolymers; polyamide resins such as polyamide 6 and polyamide 66; acrylic polymers such as polyacrylic acid, polymethacrylic acid, polyacrylic acid ester, and polymethacrylic acid ester; polycarbonate; polyethers such as polyphenylene ether, polysulfone, and polyethersulfone; polyphenylene sulfide; and halogen-containing vinyl compound polymers such as polyvinyl chloride, polyvinylidene chloride, and polyvinylidene fluoride. Examples of additives include rubbery elastic materials, antioxidants, inorganic fillers, crosslinking agents, crosslinking aids, nucleating agents, plasticizers, compatibilizers, antistatic agents, flame retardants, and matting agents.

[0027] The total content of syndiotactic polystyrene A and atactic polystyrene B may be 90% by mass or more, preferably 95% by mass or more, and more preferably 97% by mass or more, based on the total mass of the syndiotactic polystyrene fibers. The total mass of the syndiotactic polystyrene fibers includes the mass of oils and other components attached to the fiber surface in addition to the mass of the above mixture.

[0028] The fibers of the present invention have a crystallite size D(110) in the (110) plane determined by X-ray diffraction that is greater than 0 Å and 75 Å or less, and a crystallite size D(002) in the (002) plane that is between 75 Å and 110 Å. The crystallite size D(110) in the (110) plane represents the crystallite size corresponding to the fiber axis direction, and the crystallite size D(002) in the (002) plane represents the crystallite size corresponding to the direction perpendicular to the fiber axis direction. Lowering the degree of crystallinity increases the amorphous region, which can lead to improved dyeability with disperse dyes, but also an increased boiling water shrinkage rate. This is a trade-off relationship. However, in the present invention, it was found that simply adjusting the crystallinity and other crystal ratios is insufficient to adjust both the dyeability with disperse dyes and the shrinkage rate at high temperatures. It was found that the crystallite size in the fiber axis direction and the direction perpendicular to the fiber axis have an influence, and that by adjusting each to a specific range, the dyeability and boiling water shrinkage rate can be adjusted to be equivalent to that of polyester fibers. The crystallite size D(110) is preferably 1 Å to 74 Å, more preferably 10 Å to 73 Å, even more preferably 15 Å to 73 Å, and even more preferably 20 Å to 73 Å. The crystallite size D(002) is preferably 75 Å to 105 Å, more preferably 78 Å to 105 Å, and even more preferably 80 Å to 100 Å. In this specification, each crystallite size is a value measured by the method described in the examples below.

[0029] The ratio (D(110) / D(002)) of the crystallite size D(110) on the (110) plane to the crystallite size D(002) on the (002) plane may be 0.10 or more and less than 1.0, preferably 0.20 or more and 0.95 or less, more preferably 0.30 or more and 0.90 or less, and even more preferably 0.50 or more and 0.90 or less, from the viewpoint of achieving both improved dyeability with disperse dyes and reduced boiling water shrinkage.

[0030] Syndiotactic polystyrene fibers may have a Hermann orientation of 0.00 to 0.40 in the equatorial direction, preferably 0.10 to 0.38, more preferably 0.20 to 0.35, even more preferably 0.25 to 0.35, and even more preferably 0.28 to 0.33, from the viewpoint of adjusting dyeability and boiling water shrinkage rate. The Hermann orientation indicates the orientation state of the crystals in the fiber calculated using Hermann's orientation function, where 1 represents perfectly parallel orientation with respect to the fiber axis direction, 0 represents random orientation, and -0.5 represents perfectly perpendicular orientation. The equatorial direction is the direction perpendicular to the fiber axis direction. In this specification, the Hermann orientation is a value measured by the method described in the examples below.

[0031] Syndiotactic polystyrene fibers may have a crystallinity of 25% to 40%, preferably 27% to 39%, more preferably 29% to 38%, and even more preferably 32% to 37%, from the viewpoint of adjusting dyeability and boiling water shrinkage rate. While higher crystallinity tends to reduce boiling water shrinkage rate while lowering dyeability, lower crystallinity tends to improve dyeability while increasing boiling water shrinkage rate. However, in this invention, it has been found that crystallite size influences the adjustment of dyeability and boiling water shrinkage rate. In this specification, crystallinity is a value measured by the method described in the examples below.

[0032] In syndiotactic polystyrene fibers, the fineness can be appropriately selected depending on the application, etc. For example, the single filament fineness may be 1.0 dtex or more and 5.0 dtex or less, preferably 1.5 dtex or more and 4.8 dtex or less, and more preferably 2.0 dtex or more and 4.5 dtex or less. In this specification, the single filament fineness is a value measured by the method described in the examples below.

[0033] The fiber cross-section of syndiotactic polystyrene fibers is not particularly limited and may be circular, or it may be an elliptical, flattened, cocoon-shaped, polygonal, Y-shaped, cruciate, star-shaped, multi-lobed, or any other irregular cross-section.

[0034] Syndiotactic polystyrene fibers can be appropriately selected in form depending on the application and the type of fiber structure after processing, and may be in the form of filaments (long fibers) or staples (short fibers). In the case of filaments, they may be monofilaments or multifilaments. In the case of multifilaments, the number of filaments can be appropriately selected depending on the application, for example, the number of filaments may be 2 to 144, preferably 8 to 96, and more preferably 16 to 72.

[0035] Syndiotactic polystyrene fibers include syndiotactic polystyrene A and atactic polystyrene B, and only need to have the specific crystallite size mentioned above. They may be undrawn or drawn yarns. In the case of drawn yarns, they may be POY yarns obtained by high-speed spinning, FOY yarns obtained in two steps by spinning, winding the undrawn yarn, and then drawing it in a separate device, or SDY yarns obtained in one step by a device that directly connects spinning and drawing.

[0036] Syndiotactic polystyrene fibers may have an elongation of 10% to 50%, preferably 10% to 40%, and more preferably 11% to 30%, from the viewpoint of processability and mechanical strength. In this specification, elongation refers to the elongation at break in a tensile test (elongation at break), and is a value measured by the method described in the examples below.

[0037] Syndiotactic polystyrene fibers may have a boiling water shrinkage rate of 3.0% to 20.0%, preferably 3.5% to 18.0%, more preferably 3.8% to 15.0%, and even more preferably 4.0% to 10.0%. This range of boiling water shrinkage rate is also preferred for polyester fibers. In this specification, the boiling water shrinkage rate is a value measured by the method described in the examples below.

[0038] [Fiber manufacturing method] The method for producing the fibers of the present invention is not particularly limited as long as the above-described syndiotactic polystyrene-based fibers can be obtained, but may include, for example, a fiber forming step of melt-spinning the above-described mixture containing syndiotactic polystyrene A and atactic polystyrene B, and optionally a stretching step of stretching the fibers obtained by the fiber forming step.

[0039] In this invention, the crystallite sizes D(110) and D(002) of the resulting syndiotactic polystyrene fibers can be adjusted by adjusting the molecular weight, MFR, and content of syndiotactic polystyrene A and atactic polystyrene B contained in the mixture, and by adjusting the spinning conditions and drawing conditions accordingly.

[0040] In the fiber forming process, known melt spinning methods can be used. The mixture contains syndiotactic polystyrene A and atactic polystyrene B, with the content of atactic polystyrene B being 15 to 50 parts by mass, preferably 18 to 40 parts by mass, and more preferably 20 to 30 parts by mass, per 100 parts by mass of the total of syndiotactic polystyrene A and atactic polystyrene B. As described above, the mixture may also contain other components other than syndiotactic polystyrene A and atactic polystyrene B, to the extent that they do not hinder the effects of the present invention. For example, increasing the content of atactic polystyrene B relative to the total amount of syndiotactic polystyrene A and atactic polystyrene B in the mixture tends to decrease the crystallite size D(110) and increase the crystallite size D(002).

[0041] The mixture may be pelletized by mixing syndiotactic polystyrene A, atactic polystyrene B, and optionally other components, and then supplied to a melt spinning apparatus as a pelletized product. Alternatively, each component may be fed into an extruder, melt-kneaded and mixed, and then supplied directly to the spinning head as a melt-kneaded product. When obtaining the pelletized product, known kneading equipment can be used, for example, by pre-mixing with a ribbon blender, drum tumbler, Henschel mixer, etc., and then using a Banbury mixer, single-screw extruder, twin-screw extruder, multi-screw extruder, Connida, etc.

[0042] The molten mixture discharged from the nozzle's discharge hole is rapidly cooled and becomes a yarn. This yarn is subjected to tensile stress for drawing, and orientation crystallization progresses as it cools. The degree of crystallization may be adjusted by controlling the spinning conditions to prevent rapid cooling of the yarn immediately after discharge, while promoting crystallization by increasing the spinning speed to a certain extent. For example, the spinning speed (draw speed) varies depending on the desired fineness, but may be 1000 m / min or more, preferably 1100 to 3000 m / min, and more preferably 1200 to 2500 m / min. In addition, cooling air may be blown directly below the discharge point to prevent rapid cooling of the yarn immediately after discharge, and the temperature and speed of the cooling air may be adjusted. For example, the temperature of the cooling air may be adjusted to 15 to 40°C and the speed to 0.1 to 2.5 m / s.

[0043] From the viewpoint of reducing the fineness of the fibers and adjusting their crystallinity, the process may include a stretching step for stretching the fibers obtained by the fiber forming process described above. In the stretching step, known stretching methods can be used. The unstretched fibers obtained by the fiber forming process may be wound up and then unwound before stretching, or they may be directly connected to the spinning process and stretched without being wound up from the spinning process. For example, increasing the stretching ratio tends to increase the crystallite size D(110) and decrease the crystallite size D(002).

[0044] [Textile structures] The fibers of the present invention can be used in various applications as fiber structures containing at least a portion of them. The fiber structures may be one-dimensional structures such as various filament yarns, spun yarns, strings, cords, and ropes obtained by processing fibers in the form of filaments or staples, or two-dimensional structures such as fabrics such as woven fabrics, knitted fabrics, and nonwoven fabrics. Such fiber structures can be manufactured using syndiotactic polystyrene fibers by known methods.

[0045] The fibrous structure may be a combination of syndiotactic polystyrene fibers and other fibers. For example, composite yarns using syndiotactic polystyrene fibers and other fibers can be used (e.g., blended yarns (filament yarns) made by blending syndiotactic polystyrene fibers and other fibers, blended yarns (spun yarns) made by blending syndiotactic polystyrene fibers and other fibers, etc.). In addition, composite fabrics using syndiotactic polystyrene fibers and other fibers can be used (e.g., mixed fabrics using a mixture of syndiotactic polystyrene fibers and other fibers, or laminates of fabrics made of syndiotactic polystyrene fibers and fabrics made of other fibers, etc.).

[0046] Since the fibers of the present invention have dyeability and boiling water shrinkage rate equivalent to those of polyester fibers, the fiber structure may also contain polyester fibers as other fibers. The polyester fibers are fibers containing a polyester resin. The polyester resin is a polycondensate of a dicarboxylic acid and a diol, and a polyester resin having an aromatic dicarboxylic acid as the main dicarboxylic acid component is preferred, such as polyethylene terephthalate, polytetramethylene terephthalate, and polycyclohexanedimethylene terephthalate. These polyester resins may also be copolymers obtained by copolymerizing other diols or other dicarboxylic acids such as isophthalic acid as a third component. Among these, polyethylene terephthalate is more preferred.

[0047] Fiber structures containing syndiotactic polystyrene fibers and polyester fibers include blended yarns obtained by blending syndiotactic polystyrene fibers and polyester fibers, blended yarns obtained by blending syndiotactic polystyrene fibers and polyester fibers, composite fabrics containing such blended yarns or blended yarns, and mixed fabrics using a mixture of syndiotactic polystyrene fibers and polyester fibers.

[0048] Because syndiotactic polystyrene fibers exhibit excellent dyeability with disperse dyes, the fiber structure may contain disperse dyes. Any disperse dye used for dyeing polyester fibers can be used for syndiotactic polystyrene fibers, and various disperse dyes such as monoazo, disazo, quinolone azo, anthraquinone, aminoquinone, nitrodiphenylamine, imino, quinone, and quinophthalone may be used. Dyeing of the fiber structure with disperse dyes can be carried out by known methods. Since syndiotactic polystyrene fibers have a boiling water shrinkage rate equivalent to that of polyester fibers, the dyeing temperature may be 100°C or higher, 120°C or higher, or 130°C or higher.

[0049] In fiber structures containing disperse dyes, syndiotactic polystyrene fibers exhibit excellent dyeability with disperse dyes, so the color density (K / S) may be 15.5 or higher, preferably 16.0 or higher, more preferably 18.0 or higher, even more preferably 20.0 or higher, and even more preferably 22.0 or higher. This range of color density (K / S) is also preferred for polyester fibers. In this specification, the color density (K / S) is a value measured by the method described in the examples below.

[0050] The fiber structures containing the fibers of the present invention can be used for various applications such as clothing, interior design, and industrial materials. Syndiotactic polystyrene fibers have excellent quick-drying properties, water repellency, lightness, and heat resistance, and can be used, for example, in clothing applications such as sportswear, innerwear (underwear, socks, swimwear, etc.), and down (fluff), in interior applications such as carpets, bedding, and covers, and in industrial materials such as umbrellas, waterproof sheets, and ropes, but clothing applications are particularly preferred. [Examples]

[0051] The present invention will be described in more detail below based on examples, but the present invention is not limited thereto. In the following examples and comparative examples, various physical properties were measured by the methods described below.

[0052] (stereoregularity) The stereoregularity of polystyrene is determined by nuclear magnetic resonance spectroscopy using isotopic carbon. 13 Quantitative identification was performed using 1C-NMR. 13 By using 1C-NMR spectroscopy, the proportion of each stereostructure of two consecutive structural units was quantified, and polystyrene exhibiting stereoregularity with a racemic diad (r) of 75 mol% or more was identified as syndiotactic polystyrene.

[0053] (Weight average molecular weight) The weight-average molecular weight was measured by gel permeation chromatography (GPC) at 145°C after dissolving syndiotactic polystyrene in 1,2,4-trichlorobenzene. Polystyrene was used as a standard substance for calculating the weight-average molecular weight.

[0054] (MFR) Melt flow rate (MFR) was measured using polystyrene samples in accordance with JIS K 7210-1:2014. Syndiotactic polystyrene was measured under conditions of 300°C and a load of 1.2 kg, while atactic polystyrene was measured under conditions of 200°C and a load of 5 kg.

[0055] (crystallite size) The syndiotactic polystyrene fibers obtained in the examples and comparative examples were measured using the following measuring apparatus and conditions. One yarn of syndiotactic polystyrene fiber was used as the sample. Measurements were taken in the equatorial direction with the fiber axis set vertically (Psi axis = 90°) and in the meridian direction with the fiber axis set horizontally (Psi axis = 0°). Measurement equipment: Bruker D8 Discover IμS X-ray diffractometer with two-dimensional detector. Detector: 2D PSPC・VANTEC-500 X-ray source: CuKα (λ=1.5418Å) Measurement conditions: Current = 1mA, Voltage = 50kV, Camera distance = 10cm, Collimator diameter = 0.5mm, Exposure time = 600sec, 2θ axis = 20°, θ axis = 10°, Psi axis = 90° (equator), 2θ axis = 40°, θ axis = 20°, Psi axis = 0° (meridian)

[0056] The two-dimensional diffraction patterns obtained from the above measurements in the equatorial and meridian directions were converted into diffraction angle-intensity profiles, where the horizontal axis is the diffraction angle (2θ) and the vertical axis is the X-ray diffraction intensity, under the following conditions, and baselines were set. Regarding the crystallite size D(110) on the (110) plane, the two-dimensional image in the equatorial direction was transformed under the conditions of 2θ = 3 to 20°, γ (azimuthal angle) = 255 to 285°, and step size = 0.02°. For the diffraction peak observed around 2θ = 7° in the diffraction angle-intensity profile in the equatorial direction, the baseline was defined as a straight line connecting 2θ = 5° and 9°. Regarding the crystallite size D(002) in the (002) plane, the meridian-direction two-dimensional image was transformed under the conditions of 2θ = 25 to 50°, γ (azimuthal angle) = 250 to 290°, and step size = 0.02°. For the diffraction peak observed around 2θ = 35° in the meridian-direction diffraction angle-intensity profile, the baseline was defined as a straight line connecting 2θ = 32° and 38°.

[0057] The peak position and full width at half maximum of each diffraction peak observed in the diffraction angle-intensity profiles in the equatorial and meridian directions obtained by the above method were measured, and D(110) and D(002) were calculated, respectively, using the following formula (Scherrer's formula). D = Kλ / Bcosθ In the formula, D is the crystallite size (Å), K is the Scherrer constant, λ is the wavelength of the X-ray (Å), B is the diffraction line width (full width at half maximum) (°), and θ is the Bragg angle (°).

[0058] (Harman orientation) The syndiotactic polystyrene fibers obtained in the examples and comparative examples were measured using the following measuring apparatus and conditions. One yarn of syndiotactic polystyrene fiber was used as the sample, and the fiber axis was set vertically (Psi axis = 90°) for measurement. Measurement equipment: Bruker D8 Discover IμS X-ray diffractometer with two-dimensional detector. Detector: 2D PSPC・VANTEC-500 X-ray source: CuKα (λ=1.5418Å) Measurement conditions: Current = 1mA, Voltage = 50kV, Camera distance = 10cm, Collimator diameter = 0.5mm, Exposure time = 600sec, 2θ axis = 0°, θ axis = 0°, Psi axis = 90°

[0059] The two-dimensional diffraction patterns obtained from the above measurements were converted into azimuth-intensity profiles, where the horizontal axis represents the azimuth angle (γ) and the vertical axis represents the X-ray diffraction intensity, under the conditions of 2θ = 11 to 13°, γ = 180 to 360°, and step size = 0.5°. The data used for the analysis was obtained by subtracting the blank measurement values ​​from the measured data values.

[0060] The degree of Hermann orientation f was calculated from the azimuth-intensity profile obtained by the above method using the following formula.

number

[0061] (Degree of crystallinity) The syndiotactic polystyrene fibers obtained in the examples and comparative examples were measured using the following measuring apparatus and conditions. One yarn of syndiotactic polystyrene fiber was used as the sample. Measurements were taken in the equatorial direction with the fiber axis set vertically (Psi axis = 90°) and in the meridian direction with the fiber axis set horizontally (Psi axis = 0°). Measurement equipment: Bruker D8 Discover IμS X-ray diffractometer with two-dimensional detector. Detector: 2D PSPC・VANTEC-500 Measurement conditions: Current = 1mA, Voltage = 50kV, Camera distance = 10cm, Collimator diameter = 0.5mm, Exposure time = 600sec, 2θ axes = 0·20·40°, θ axis = 0·10·20°, Psi axis = 90° (equator)·0° (meridian)

[0062] The two-dimensional diffraction patterns obtained from the above measurements in the equatorial and meridian directions were added together and converted into a diffraction angle-intensity profile, where the horizontal axis is the diffraction angle (2θ) and the vertical axis is the X-ray diffraction intensity, under the following conditions. 2θ = 3.0~55.0°, γ = 225~315°, step size = 0.02°

[0063] Then, from the peaks of the diffraction angle-intensity profile obtained by the above method, the peak areas of the amorphous and crystalline regions were calculated using the peak separation method under the following conditions. Analysis range: 2θ = 4 to 30° Baseline: A straight line connecting the values ​​of 2θ = 4° and 30°. Amorphous peak: The initial peak position was set to 19.6°, and the amorphous peak was fitted to the measured data with 2θ = 15~16° so that it was tangent to the amorphous peak. The area value of the region enclosed by the amorphous peak and the baseline was calculated and defined as the amorphous peak area. Crystal peaks: For seven peaks with peak positions of 7.0°, 9.0°, 12.0°, 13.5°, 20.0°, 20.5°, and 20.6°, the crystal peak height, peak position, and FWHM were varied during fitting. The area value of the region enclosed by each crystal peak and the baseline was calculated, and the sum of these area values ​​was defined as the crystal peak area. The degree of crystallinity was calculated from the obtained amorphous and crystalline peak areas using the following formula. Crystallinity (%) = (Crystalline peak area) / (Crystalline peak area + Amorphous peak area) × 100

[0064] (Total fineness and single yarn fineness) A 100m skein of syndiotactic polystyrene fiber was prepared using a measuring machine with a frame circumference of 1.0m. The weight per unit length was measured under conditions of 20°C and 65% RH, and the total fineness (dtex) was measured according to the following formula. This measurement was repeated 10 times, and the simple average value, rounded to the nearest whole number, was taken as the total fineness of the obtained syndiotactic polystyrene fiber. Total fineness (dtex) = Weight of 100m skein (g) × 100 Furthermore, the single-fiber fineness (dtex) was calculated by dividing the total fineness by the number of filaments according to the following formula. Single yarn fineness (dtex) = Total fineness (dtex) / Number of filaments (strands)

[0065] (Elongation) Elongation was measured using syndiotactic polystyrene fibers obtained in the examples and comparative examples, in accordance with JIS L 1013:2010 (Test Methods for Chemical Fiber Filaments) 8.5.1. Tensile tests were performed using a Shimadzu Autograph "AGS-X" under conditions of an initial sample length of 20 cm and a tensile speed of 20 cm / min at a temperature of 20°C and a humidity of 65% RH. Elongation (%) was calculated using the following formula with the elongation at the point of maximum load (L1) and the initial sample length (L0). Measurements were performed 10 times for each sample, and the average value was used as the elongation of the syndiotactic polystyrene fiber. Elongation (%)={(L1-L0) / L0}×100

[0066] (Boiling water shrinkage rate) The fiber sample was wound 10 times using a measuring machine with a circumference of 1m and left unloaded for 24 hours. Then, a load twice the total fineness was applied to the sample, and the length measurement (La) was read after 30 seconds. The sample was treated with 100°C hot water for 30 minutes, dried for 24 hours, and then a load twice the total fineness was applied again. The length measurement (Lb) was read after 30 seconds, and the boiling water shrinkage rate (Wsr) was calculated using the following formula. Boiling water shrinkage rate (Wsr)[%]={(La-Lb) / La}×100

[0067] (Color density (K / S)) Using an Eiko Sangyo NCR-BL circular knitting machine (3.5 inches (8.9 cm) diameter, 27 gauge), a tubular knitted fabric of syndiotactic polystyrene fibers was prepared. After scouring this tubular knitted fabric, it was preset at 150°C, dyed under the following conditions, and then reduced-washed to obtain dyed samples. (staining) Dye: Kayalon Microester Blue C-LS 1.0%owf Additive: ULTRAMT-N2 1.0cc / L Bath ratio: 1 / 50 Dyeing temperature x time: 130℃ x 40 minutes (Reduction cleaning) Sodium carbonate: 1.0 g / L Sodium hydrosulfite: 1.0 g / L Amylazine D: 1.0g / L Bath ratio: 1 / 50 Reduction wash temperature x time: 80℃ x 20 minutes

[0068] The dye concentration (K / S) was determined by measuring the reflectance R at the maximum absorption wavelength of the dyed sample fabric using a spectrophotometer (HITACHI C-2000S Color Analyzer) and calculating it using the Kubelka-Munk formula shown below. K / S = (1 - R) 2 / 2R

[0069] [Example 1] 80 parts by mass of syndiotactic polystyrene (SPS; manufactured by Idemitsu Kosan Co., Ltd., weight-average molecular weight: 150,000, MFR (300℃, 1.2kg): 30g / 10min) and 20 parts by mass of atactic polystyrene (APS; "G9305" manufactured by PS Japan Co., Ltd., MFR (200℃, 5kg): 1.5g / 10min) were melt-kneaded using a twin-screw extruder under conditions of 250 rpm and 290℃ to be processed into pellets. Subsequently, the mixture was subjected to crystallization treatment in an oven under conditions of 150℃ for 2 hours to obtain pellets of a styrene-based resin composition (mixture).

[0070] The resulting styrene resin composition pellets were spun using a 48-pore die (pore diameter 0.20 mmφ) at a spinning temperature of 300°C and a total discharge rate of 32.67 g / min. Cooling air at 25°C and 60% humidity was blown onto the spun yarn at a speed of 0.5 m / s to bring the yarn temperature below 60°C. Then, an oiling agent was applied using an oiling device to converge the yarn. The yarn was taken up by a first godet roller rotating at 1300 m / min, and then wound up by a winder with a draw ratio of 1.7 and a spinning speed of 2200 m / min via a second godet roller rotating at 2200 m / min to obtain a 150 dtex-48f syndiotactic polystyrene fiber (drawn yarn).

[0071] [Example 2] Syndiotactic polystyrene fibers were obtained in the same manner as in Example 1, except that the composition of the styrene resin composition was changed to 77.5 parts by mass of syndiotactic polystyrene and 22.5 parts by mass of atactic polystyrene.

[0072] [Example 3] Syndiotactic polystyrene fibers were obtained in the same manner as in Example 1, except that the composition of the styrene resin composition was changed to 75 parts by mass of syndiotactic polystyrene and 25 parts by mass of atactic polystyrene.

[0073] [Example 4] Syndiotactic polystyrene fibers were obtained in the same manner as in Example 1, except that the composition of the styrene resin composition was changed to 72.5 parts by mass of syndiotactic polystyrene and 27.5 parts by mass of atactic polystyrene.

[0074] [Example 5] Syndiotactic polystyrene fibers were obtained in the same manner as in Example 1, except that the composition of the styrene resin composition was changed to 70 parts by mass of syndiotactic polystyrene and 30 parts by mass of atactic polystyrene.

[0075] [Example 6] Syndiotactic polystyrene fibers were obtained in the same manner as in Example 1, except that the composition of the styrene resin composition was changed to 77.5 parts by mass of syndiotactic polystyrene, 22.5 parts by mass of atactic polystyrene, and 2.0 parts by mass of titanium dioxide (TiO2).

[0076] [Comparative Example 1] Syndiotactic polystyrene fibers were obtained in the same manner as in Example 1, except that syndiotactic polystyrene was used alone instead of the styrene-based resin composition.

[0077] [Comparative Example 2] Syndiotactic polystyrene fibers were obtained in the same manner as in Example 1, except that the composition of the styrene resin composition was changed to 90 parts by mass of syndiotactic polystyrene and 10 parts by mass of atactic polystyrene.

[0078] [Table 1]

[0079] As shown in Table 1, the syndiotactic polystyrene fibers of Examples 1 to 6 contain syndiotactic polystyrene and atactic polystyrene, with a specific content of atactic polystyrene and specific crystallite sizes D(110) and D(002). As a result, the boiling water shrinkage rate is in the range of 3.0% to 20.0%, and the K / S ratio is in the range of 15.5 or higher, exhibiting boiling water shrinkage rate and dyeability equivalent to polyester fibers.

[0080] On the other hand, Comparative Example 1 does not contain atactic polystyrene and contains only syndiotactic polystyrene, so although its boiling water shrinkage rate is equivalent to that of polyester fibers, its dyeability is inferior to that of Examples 1 to 6 and is lower than that of polyester fibers.

[0081] Furthermore, in Comparative Example 2, although it contains atactic polystyrene, the amount is not specific, and the crystallite size is not within a specific range. As a result, the dyeability is inferior to that of Examples 1-6 and is lower than that of polyester fibers. [Industrial applicability]

[0082] The fibers of the present invention can be used for various applications, including clothing, interior design, and industrial materials.

[0083] As described above, preferred embodiments of the present invention have been explained, but various additions, modifications, or deletions are possible without departing from the spirit of the present invention, and such are also included within the scope of the present invention.

Claims

1. A fiber characterized by containing a mixture of syndiotactic polystyrene A and atactic polystyrene B, wherein the content of atactic polystyrene B is 15 to 50 parts by mass per 100 parts by mass of the total of syndiotactic polystyrene A and atactic polystyrene B, wherein the crystallite size D(110) in the (110) plane determined by X-ray diffraction is greater than 0 Å and 75 Å or less, and the crystallite size D(002) in the (002) plane is 75 Å or more and 110 Å or less.

2. A fiber according to claim 1, wherein the single filament fineness is 1.0 dtex or more and 5.0 dtex or less.

3. A fiber according to claim 1, wherein the degree of Herman orientation is 0.00 or more and 0.40 or less in the equatorial direction.

4. A fiber according to claim 1, wherein the degree of crystallinity is 25% or more and 40% or less.

5. A fiber according to claim 1, wherein the elongation is 10% or more and 50% or less.

6. A fiber according to claim 1, wherein the boiling water shrinkage rate is 3.0% or more and 20.0% or less.

7. A fiber structure comprising the fibers described in any one of claims 1 to 6.

8. A fiber structure according to claim 7, comprising polyester fibers.

9. Clothing comprising the fibrous structure described in claim 7.

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