JPH0314940B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing fibers having grooves on the fiber surface, which are suitable for constructing high-grade woven or knitted fabrics with excellent squeaky feel, elegant luster, and color development. In a composite fiber made of two types of thermoplastic polymers with different solubility, an easily soluble polymer is placed near the fiber surface, and after the fiber or fabric is formed, the easily soluble polymer is dissolved and removed to obtain yarns of various shapes with irregular cross sections. It will be done. For example, the present inventors have disclosed in Japanese Patent Application Laid-Open No. 55-93819 that a highly soluble polymer is dissolved and removed from a composite yarn in which an easily soluble polymer is divided into a plurality of pieces using a slightly soluble polymer, and a yarn with a highly irregular cross section is obtained. I have shown you what you can get. JP-A-56-53210 also discloses that a yarn with an irregular cross section can be obtained by removing an easily soluble polymer placed at a specific position near the fiber surface. However, although the irregular cross-section yarns obtained by these techniques can give a squeaky feel, they tend to produce a glaring luster and tend to have poor color development, and there is a need to overcome these drawbacks. As a technique for reducing glare and imparting an elegant luster, Japanese Patent Application Laid-Open No. 57-5912 discloses a technique for reducing glare and imparting an elegant luster. Although a technique was proposed in which a portion of the resin was dissolved and removed, it had the drawback that it could not necessarily provide sufficient color development. On the other hand, basic dyeable polyester is well known as a polymer with excellent dyeability. Conventionally, as a method for producing basic dyeable polyesters, it has been known to copolymerize an isophthalic acid component having a metal sulfonate group, such as a 5-sodium sulfoisophthalic acid component, as disclosed in Japanese Patent Publication No. 10497/1984. However, in this method, in order to raise the dyeability to a satisfactory level, a large amount of an isophthalic acid component (hereinafter abbreviated as S component) having a metal sulfonate group must be copolymerized. Copolymerization of such a large amount of the S component requires a high degree of polymerization for fibers due to the thickening effect of the S component, making spinning difficult.
Therefore, in order to spin a polymer copolymerized with a large amount of the S component by a conventional method, it is necessary to keep the degree of polymerization of the polymer low in order to lower the melt viscosity to a range that allows normal spinning. However, as a result, there were drawbacks such as a decrease in yarn strength, a decrease in thread-spinning property and passability to higher-order processes, and a drawback that the applications were limited. In addition, addition of a large amount of S component also causes a decrease in the alkali resistance of the yarn and a decrease in the light fastness of the dyed product.
This also limits the uses of the resulting polyester yarn. The present inventors used a composite spinning method to construct a high-quality woven or knitted fabric that has high yarn strength, excellent dyeability, light fastness and color development of the dyed product, and has a squeaky feel, a silky feel, a silky ring, and an elegant luster. We have conducted extensive research into fibers suitable for this purpose and have arrived at the present invention. That is, the present invention consists of two types of thermoplastic polymers with different solubility, and the easily soluble polymer has a surface length of 0.2 to 4μ and occupies at least two locations on the outer periphery of the fiber cross section. isophthalic acid component (hereinafter referred to as S component) having a metal sulfonate group
The polyester is copolymerized with 0.7 to 2.4 mol% of glycol component and 0.2 to 10% by weight of a glycol component with a molecular weight of 90 to 6000 and a degree of polymerization of 80 to 100, and the easily soluble polymer is the S component of the slightly soluble polymer. 0.5 mol% or more of the S component is copolymerized, and the S component is
It is a polyester copolymerized with 1.2 to 20 mol%,
At least a part of the easily soluble polymer is dissolved and removed from the composite fiber, and grooves having a depth of 0.3 to 1.8 μm or less and an entrance width of 0.2 to 4.0 μm are formed on the surface. This is a method for producing grooved fibers. First, the cross-sectional shape of the composite fiber in the present invention will be explained. FIGS. 1 and 2 show preferred cross sections of the composite fiber of the present invention, which is made of a poorly soluble polymer A and an easily soluble polymer B. The composite fiber shown in FIG. 1 is a trilobal cross-section yarn, and the easily soluble polymer occupies three locations on the fiber surface and is arranged in a tapered wedge shape toward the inside of the fiber. The composite fiber shown in FIG. 2 is a five-lobed cross-section yarn,
The easily soluble polymer occupies five locations on the fiber surface and is arranged in a wedge shape that tapers toward the inside of the fiber. When such a composite fiber is treated with an alkaline aqueous solution to dissolve and remove the easily soluble polymer, the slightly soluble polymer dissolves, but the amount is very small, and the shape of the slightly soluble polymer in the composite fiber is almost the same, with grooves on the surface. Some fibers are obtained. There are no particular restrictions on the placement of the easily soluble polymer inside the composite fiber, and it may be placed sufficiently deep in the fiber interior direction, or it may be placed even deeper to bond the easily soluble polymers together and integrate them within the cross section. Fibers with grooves on the surface may be used, but fibers with grooves on the surface can be used because when the easily soluble polymer is dissolved and removed, the easily soluble polymer remains and some of the coloring property improvement effect can be exhibited, and from the viewpoint of the coloring property improving effect. The depth of the groove in is preferably 0.2μ or more and less than 2μ, so the depth of the easily soluble polymer in the composite fiber, which will be defined later, is preferably at least 0.3μ or more, and more preferably 1μ or more. However, if easily soluble polymers are bonded to each other, the poorly soluble polymer segments may separate when the easily soluble polymer is removed, and fibers with grooves on the surface may not be obtained, which is not preferable. FIG. 3 is an enlarged view of the vicinity of the fiber surface, focusing on one easily soluble polymer in the cross section of the composite fiber. P and Q are the boundary points between the easily soluble polymer and the slightly soluble polymer on the fiber surface, and are the line segments.
Let PQ be the surface length of one easily soluble polymer.
From the viewpoint of color development and giving a squeaky feeling, the length of line segment PQ needs to be 0.2 to 4μ, and 0.3 to 3μ
A range of is preferred. In addition, the sum of the lengths of the easily soluble polymers on the fiber surface is 2 to 40% of the sum of the fiber outer circumferences of the slightly soluble polymers. It is preferable because it can produce an elegant luster when made into a certain fiber, and the content is preferably 5 to 35%. The point R closest to the midpoint S of the line segment PQ and the fiber center of gravity of the easily soluble polymer (However, if the fiber center of gravity is also occupied by the easily soluble polymer, R is the fiber center of gravity)
The line segment RS connecting these is the depth of the easily soluble polymer.
If the points that intersect with the easily soluble polymer outer periphery on a straight line perpendicular to the midpoint M of the line segment RS are T and U, then the length of the line segment TU is 40 to 90% of the length of the line segment PQ, and the direction is towards the center of fiber gravity. A tapered wedge-like shape is preferable from the viewpoint of improving color development. From the viewpoint of stably spinning composite fibers, the cross-sectional shape is preferably symmetrical with respect to the rotation axis passing through the center of gravity of the fibers. If the easily soluble polymer occupies one location on the outer periphery of the composite fiber, the probability that it will be present on the surface of the fabric is too small, and the effect of improving the squeaky feeling and color development is extremely small, so it is necessary to have two or more locations. If the number is too large, the surface gloss of fibers with grooves on the surface obtained by dissolving and removing easily soluble polymers will decrease, so the number is preferably less than 15, and the range of 3 to 12 is more preferable. . By making the cross-sectional shape of the composite fiber into an irregular cross-section, it is possible to impart an irregular cross-sectional effect, particularly silky luster. Although any known cross section can be used as the irregular cross section, a T-shaped cross section or a 3- to 6-lobed cross section is preferred from the viewpoint of imparting silky luster. Furthermore, as shown in the cross sections shown in FIGS. 1 and 2, at least a portion of the easily soluble polymer is dissolved and removed from the composite fiber in which the surface forming portion of the easily soluble polymer occupies the vicinity of the apex of the irregular cross section. If the fiber is grooved, the color development and squeaky feeling can be significantly improved, so it is preferable that the fiber is a composite fiber in which at least a portion of the surface forming portion of the easily soluble polymer occupies the vicinity of the apex of the irregular cross section. . Note that the apex of the irregular cross section is the farthest point F from the fiber center of gravity in the convex portion when viewed from the direction of the fiber center of gravity, and occupying the vicinity of the apex means including and occupying the apex. Next, the hardly soluble polymer will be explained. The poorly soluble polymer supplied when spinning composite fibers is copolymerized with 0.7 to 2.4 mol% of the S component and 0.2 to 10% by weight of a glycol component with a molecular weight of 90 to 6000.
It is a polyester having a degree of polymerization of 80 to 100.
By copolymerizing the glycol component in the S component copolymerization system, the following becomes possible. One of them is that by copolymerizing glycol components, satisfactory dyeing properties can be obtained with a small amount of S component copolymerized.
This is because the glycol component has the effect of increasing the effective utilization rate of the S component in the polymer for basic dyes. Second, by copolymerizing the glycol component, a polymer with the same melt viscosity and high degree of polymerization can be obtained in the S component copolymerization system. This is because a polymer having the same melt viscosity and a high degree of polymerization can be obtained in a copolymerization system in which the glycol component is S component. This is because the glycol component has the function of lowering the melt viscosity of the polymer in the S component copolymerization system without lowering the degree of polymerization. In other words, by copolymerizing a glycol component with an S component copolymerization system, a polymer can be obtained that has satisfactory dyeability within the melt viscosity range that allows normal spinning and has a polymerization degree of 80 to 100. This can only be obtained by reducing the melt viscosity due to a decrease in the amount of S component copolymerized by copolymerizing the glycol component, and by decreasing the melt viscosity by copolymerizing the glycol component. When a polymer having the above effects is used as a poorly soluble polymer to make a composite fiber and a fiber with grooves on the surface, an S component copolymer polymer that does not substantially contain glycol and has the same level of dyeability is used. Compared to the case, the following effects can be obtained.
It has high yarn strength as a composite fiber, good spinning properties, and good passability through higher-order processes.When performing an alkali treatment, which is a particularly preferred treatment method when dissolving composite fibers, the alkali dissolution rate is low, and the surface Fibers with grooves have the effect of increasing strength due to both the strength-improving ability of the polymer itself and the low alkali dissolution rate. In the present invention, the S component is a compound represented by the following formula, specifically dimethyl (5-sodium sulfo) isophthalate, bis-2-hydroxyethyl (5-sodium sulfo) isophthalate, bis-4-hydroxy Butyl (5-sodium sulfo) isophthalate and the like can be mentioned. (However, M represents an alkali metal such as Na, Li, or K, and A and A' represent -CH ₃ or -(CH ₂ ) nOH. n represents an integer of 2 or more.) A preferred S component is dimethyl (5-sodium sulfo) isophthalate and bis-2-hydroxyethyl (5-sodium sulfo) isophthalate. It is necessary to copolymerize the S component in an amount of 0.7 to 2.4 mol %, preferably 0.9 to 2.0 mol %, based on the obtained polyester. If the S component is less than 0.7 mol%, satisfactory dyeing properties cannot be obtained even if the amount of glycol copolymerized is increased or the dyeing temperature is raised. This is due to the lack of S component in the polymer that reacts with the basic dye. On the other hand, if an attempt is made to obtain a polymer with an S component exceeding 2.4 mol% and a polymerization degree of 80 or higher, the melt viscosity of the polymer will increase significantly due to the thickening effect as a result of copolymerizing the S component, making it difficult to spin by normal methods. It becomes difficult. The S component may be added at any time until the polyester production reaction is completed, but it is preferable that the added S component is sufficiently copolymerized into the polyester chain. Therefore, it is preferable to add it at a stage before the initial stage of the polycondensation reaction.
The glycol component must have a molecular weight in the range of 90 to 6,000. If the molecular weight is less than 90, the effect of improving dyeability will be small, which is not preferable. Furthermore, a glycol component having a molecular weight exceeding 6,000 is undesirable because it reduces the light fastness of dyed fibers obtained from a polymer copolymerized with the glycol component. The molecular weight of the glycol component is more preferably 100-4000, particularly preferably 100-900. Glycol components with a molecular weight of 90 to 6000 include neopentyl glycol, 1,4
-butanediol, 1,5-pentanediol,
Examples include 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, bisphenol A-ethylene oxide adduct, and polyalkylene glycol represented by the following formula. A (C _o H _2o O) _n H (A is C _l H _2l+1 O or OH, l is 1 to 10, n is 2 to
5, m is 2 to 65) A more preferable glycol component is polyalkylene glycol. This is because polyalkylene glycol has a greater viscosity-reducing effect than other glycols, so it is more advantageous than other glycols in obtaining a polymer with a degree of polymerization of 80 to 100. The copolymerized amount of the glycol component must be 0.2 to 10% by weight based on the resulting polyester. If the amount is less than this range, the effect of improving dyeability will be small, and if it is more than this range, the physical properties, especially heat resistance, will be greatly reduced. Therefore, the range of 0.3 to 7% by weight is more preferable. The addition time may be at any stage until the polyester production reaction is completed, but it is preferably added at a stage before the initial stage of the polycondensation reaction. When added, it may be added at the same time as the S component, or may be added separately in any order. The degree of polymerization of the hardly soluble polymer supplied when obtaining the composite fiber in the present invention by composite spinning method is 80~
It needs to be 100, and preferably 90-100. If the degree of polymerization is less than 80, the yarn strength of the composite fibers and fibers with grooves on the surface that are the object of the present invention will not be at a satisfactory level, and if it exceeds 100, the melt viscosity of the polymer will be too high and spinning will be difficult. It becomes difficult. Although a polymer having a degree of polymerization of 80 to 100 may be obtained by polycondensation reaction alone, it is preferable to use solid phase polymerization reaction in combination. The dyeing temperature of the fibers can be changed as appropriate depending on the polymer composition, but is preferably in the range of 110 to 140°C. In addition, the polyester referred to in the present invention is one in which at least 80 mol% of the structural units are ethylene terephthalate or butylene terephthalate, and in addition to the above-mentioned S component and glycol component, 10 mol% or less, preferably 5 mol% or less of other components are copolymerized. It's okay to do so. Next, the easily soluble polymer to be supplied when spinning composite fibers by the composite spinning method will be explained. The easily soluble polymer may be appropriately selected from known thermoplastic polyamides, polyesters, polyolefins, etc., depending on the relationship between the solvent and the slightly soluble polymer, but if the combination is such that both polymers are incompatible, yarn spinning and high It is preferable to use a combination of polymers that have good compatibility, since peeling between the polymers may occur in the next step, resulting in fuzz, thread breakage, etc. Note that "good compatibility" refers to one in which substantially no peeling between polymers is observed in the drawn conjugate fiber. As a treatment method for dissolving and removing at least a part of the easily soluble polymer, alkaline aqueous solution treatment can be suitably used from the points of view of ease of operation, safety, cost, etc. From this point of view, as the easily soluble polymer, is required to be an alkali easily soluble polymer. Examples of easily alkali-soluble polymers include copolymers or blends of polyester and polyalkylene glycols, polyesters containing anionic surfactants, polyesters containing metal sulfonate groups, or combinations of polyester and polyester containing metal sulfonate groups. There are blends etc. Since it can be dissolved and removed more easily and evenly than composite fibers, it is an easily soluble polymer that copolymerizes an S component that is 0.5 mol% or more more than the S component of a poorly soluble polymer, and has an S component of 1.5 mol%.
~20 mol% copolymerized polyester is required, especially 5-sodium sulfoisophthalate that is 3 mol% or more and 2 mol% or more than the S component of the poorly soluble polymer, and 70 mol% or more of terephthalate. Polyesters that are modified polyethylene terephthalate are preferred. Unless the ratio of the dissolution rate of the easily soluble polymer to the slightly soluble polymer in the solvent treatment is greater than 1, the fibers with grooves on the surface of the present invention cannot be obtained.
The ratio of dissolution rates is preferably 3 times or more,
More preferably, it is 5 times or more. When both the easily soluble polymer and the slightly soluble polymer are polyesters, the easily soluble polymer has a smaller intrinsic viscosity when fed to composite spinning, and the greater the difference between the two, the more grooves will be formed on the composite fibers and surface. Since the strength of certain fibers is improved, the intrinsic viscosity of the easily soluble polymer is preferably 0.05 or more lower than the intrinsic viscosity of the hardly soluble polymer, and more preferably 0.1 or more lower. Note that the polymer forming the composite fiber may contain well-known additives such as matting agents, antioxidants, optical brighteners, flame retardants, and ultraviolet absorbers to the extent that they do not impede the effects of the present invention. It is possible. The method for producing composite fibers can be easily achieved by adapting the method proposed earlier in Japanese Patent Application Laid-Open No. 55-93819. The weight ratio of both polymers in the composite fiber is easily soluble polymer: hardly soluble polymer: 2:98
It is preferable to set the ratio in the range of 35:65 to remove all of the easily soluble polymer to obtain fibers with grooves on the surface, because this makes it easier to obtain uniform dyeing in dyed fabrics. The fibers with grooves on the surface may be either filament-like or cotton-like, and the fineness is preferably in the range of 0.5 to 10 denier, which is usually used for clothing. It can also be used in combination with other fibers. Although it is possible to directly process the composite fiber to dissolve and remove at least a portion of the polymer that is more easily soluble than the composite fiber, post-treatment of the composite fiber as a woven or knitted fabric has greater processing efficiency; It is preferable because it can improve the bulkiness and soft feel of woven or knitted fabrics by forming spaces between the fibers. In the latter case, it is preferable to perform scouring and shape fixing treatment under conditions that do not cause wrinkles in the woven or knitted fabric after knitting and weaving, and then to perform dissolution and removal treatment to remove at least a portion of the easily soluble polymer. As explained above, the alkali aqueous solution treatment is preferable as the dissolution and removal treatment, and the fibers are removed using a heated aqueous solution of alkali metal hydroxide using a batch method, Zitzker, wince, beam, hanging tank, etc. Alternatively, any commonly known method for treating woven or knitted fabrics may be used. In order to increase the rate of elution of easily soluble polymers, phenolic substances, amine substances, quaternary ammonium salts, high boiling point polyhydric alcohols, etc. may be added to the alkaline aqueous solution. Among the alkali metal hydroxides, it is preferable to use sodium hydroxide because it is low in cost and has a high elution ability. It is preferable to use it as °C. The groove shape of the fiber, which has grooves on the surface obtained by dissolving and removing at least a part of the easily soluble polymer, further improves color development and gives a sufficient squeaky feeling and elegant gloss. The depth (corresponding to the length of line segment PQ in the figure) must be 0.2 to 4μ, and the depth (corresponding to the length of line segment SR in Figure 3) must be 0.3 to 1.8μ.
is required, and 1μ or more is more preferable. As explained above, the fibers with grooves on the surface of the present invention are suitable for constructing high-quality woven and knitted fabrics that have a squeaky feel, elegant luster, and excellent color development.
A similar effect can be achieved even if bulk processing such as fluid turbulence processing is performed. In addition, the manufacturing method can be easily achieved without using special polymers, equipment, or processing methods. The present invention will be specifically explained below with reference to Examples. The quantitative analysis of the glycol component in the polymer was performed using gas chromatography or liquid chromatography after decomposing the polymer with amines. The degree of polymerization was calculated by determining the number of terminal groups per unit weight using a commonly used method and using the following formula. Degree of polymerization = 2 x 10 ⁶ /number of terminal groups (co/10 ⁶ g) x average molecular weight of polymer Intrinsic viscosity is the value measured at 25°C in orthochlorophenol. Light fastness is measured using a fade meter according to JIS-
It was measured using a blue scale standard when photobleached according to L1044. Dyeability: malachite green (trade name: Kanto Chemical) 5% owf, acetic acid 0.5g/, acetic acid soda 0.2
g/, the dye grade exhaustion rate was determined by dyeing under the conditions of a bath ratio of 1:100 and a temperature of 120° C. in solvent water. Example 1 Ethylene 5-sodium sulfoisophthalate (5 mol%)/ethylene terephthalate (95 mol%) copolymer with an intrinsic viscosity of 0.52 was used as the easily soluble polymer, and terephthalic acid (98.3 mol%) was used as the acid component as the slightly soluble polymer. A polyester containing 5-sodium sulfoisophthalic acid (mol%) and 5-sodium sulfoisophthalic acid (1.7 mol%), ethylene glycol as the glycol component, and the glycols shown in Table 1 was used, and composite spinning was performed at a spinning temperature of 300°C and a spinning speed of 1050 m/min. A composite fiber having a cross section as shown in Figure 1 was obtained. The easily soluble polymer accounts for 10% by weight in this composite fiber. Continue stretching speed 500m/min, heating roller 90
The yarn was drawn on a hot roll at a draw ratio such that the elongation of the drawn yarn was 30±2% at ℃ to obtain a drawn yarn of 75 denier and 36 filaments. The surface length of one easily soluble polymer in the cross section is 1.1 to 1.3μ, the depth is 2.5 to 2.7μ, and the line segment
The ratio of length to surface length of TU was in the range of 75-80%. However, the degree of polymerization of the poorly soluble polymers in Nos. 1 to 7 and Comparative Examples Nos. 2 and 3 is 90 and the intrinsic viscosity is in the range of 0.70 to 0.74, and the poorly soluble polymer in Comparative Example 1 is ethylene 5-sodium sulfonate. Isophthalate (2.5 mol%)/Ethylene terephthalate (97.5 mol%)
It is a copolymer with a degree of polymerization of 70 and an intrinsic viscosity of 0.60. As Comparative Example 4, the poorly soluble polymer of Comparative Example 1 was solid-phase polymerized to a degree of polymerization of 83, but the melt viscosity was too high and composite spinning could not be performed. There was no part of the drawn yarn that was separated between the easily soluble polymers, and in the drawing of Comparative Example 1, due to the low strength, the single yarn was wrapped around the drawing roller and fluff was sporadic, but other levels were problematic. Nakatsuta. These drawn yarns are twisted at 200T/m and glued as warp yarns, and left as they are as weft yarns with a weave density and warp.
Habutae was woven with 110 threads/inch and weft of 90 threads/inch. Yarn breakage based on warp during weaving is Comparative Example 1
The number of threads used was as high as 4.0 times/10 ⁷ m, while the number of threads used for all other threads was 0.4 times/10 ⁷ m or less, which was good. Continued alkaline aqueous solution treatment with NaOH concentration of 20
g/, at 100°C, the weight was reduced by 20%, and all of the easily soluble polymer was eluted. The groove shape of fibers with grooves on the surface other than Comparative Example 1 has an entrance width of 1.6 to 1.9μ and a depth of
It was in the range of 1.6-1.9μ. The groove shape of the fiber with grooves on the surface of Comparative Example 1 had an entrance width of 3.1 μm and a depth of 0.8 μm. This is because the dissolution rate of the easily soluble polymer in composite yarns other than Comparative Example 1 is higher than that of the slightly soluble polymer.
This is based on the fact that the dissolution rate of the easily soluble polymer of Comparative Example 1 is 4.5 times lower than that of the slightly soluble polymer, whereas it is 10 to 12 times higher. The fabrics using Nos. 1 to 7 had excellent squeaky feel, silky ringing, elegant luster, dyeability, color development, and light fastness, and the yarn strength of the constituent threads was also high. The fabric used in Comparative Example 1 has a squeaky feel, insufficient color development, and the strength of the constituent threads is extremely low.The fabric used in Comparative Example 2 has low dyeability, and the fabric used in Comparative Example 3 has poor light fastness. It was hot. Example 2 A polyester containing terephthalic acid (98.6 mol%) and 5-sodium sulfoisophthalic acid (1.4 mol%) as acid components and ethylene glycol and tetraethylene glycol (6.6% by weight) as glycol components as a poorly soluble polymer. Heat the degree of polymerization to 70,
82, 91, 100, 113 (intrinsic viscosity is 0.61,
Composite spinning, stretching, weaving, and alkaline aqueous solution treatment were carried out in the same manner as in Example 1, except that 0.64, 0.80, 1.02, and 1.20) were used. When No. 15 (comparative example) was used, the melt viscosity was high and spinning was impossible. There was no separation between the easily soluble polymer and the slightly soluble polymer in the drawn yarn, making it No. 11.
(Comparative example), the strength of the drawn yarn is low.

【table】

[Table] * Melt viscosity is too high to spin.
Based on the results, there were occurrences of single yarn wrapping around the drawing roller and sporadic occurrence of fuzz on the drawn yarn, but there were no other problems.
The surface length of one easily soluble polymer in the cross section was 1.1 to 1.3μ, the depth was 2.4 to 2.6μ, and the ratio of the length of the line segment TU to the surface length was in the range of 72 to 76%. During weaving, thread breakage based on the warp thread was 3.4 times/10 ⁷ m for thread No. 11 (comparative example), whereas it was less than 0.5 times/10 ⁷ m for all other threads. It was hot. The dissolution rate of easily soluble polymers is 12 to 13 times that of poorly soluble polymers, and when treated with alkaline aqueous solution,
At the time of % reduction, all of the easily soluble polymer has been dissolved and removed. The groove shape of the fibers with grooves on the surface had an entrance width of 1.6 to 1.8μ and a depth of 1.6 to 1.9μ. Fabrics using No. 12 to 14 have excellent squeaky feel, silky sound, elegant luster, dyeability, color development, and light fastness.
The strength of the constituent threads was also great. No. 11 (comparative example) The yarn strength of the yarn constituting the fabric used was extremely low. Example 3 Multifilament in which the number of easily soluble polymers in the cross section of the composite fiber of Experiment No. 13 of Example 2 was 1 (Experiment No. 21 (comparative example)) and 2 (Experiment No. 22) The yarn was spun, woven, and treated with an alkaline aqueous solution in accordance with Experiment No. 13 of Example 2 to obtain a fiber having a groove shape with an entrance width of 1.6 to 1.8 μm and a depth of 1.5 to 1.9 μm. experiment
The fabric of No. 21 had a squeaky feel, a silky ring, and poor coloring effects. The fabric of Experiment No. 22 had the effects of squeaking, silkiness, and color development, and was a good fabric.

[Brief explanation of drawings]

FIGS. 1 and 2 are cross-sectional views of typical composite fibers in the present invention, and FIG. 3 is an enlarged explanation of a cross-sectional portion focusing on one easily soluble polymer in the cross-section.

Claims (1)

[Scope of Claims] 1. When composite fiber is composed of two types of thermoplastic polymers having different solubility, and the easily soluble polymer occupies at least two places on the outer periphery of the fiber cross section with a surface length of 0.2 to 4μ. 0.7 to 2.4 mol% of the isophthalic acid component having a metal sulfonate group (hereinafter S component) and 0.2 to 2.4 mol% of the glycol component with a molecular weight of 90 to 6000 are used to supply the hardly soluble polymer.
10% copolymerized and the degree of polymerization is 80-100
The easily soluble polymer has an S content of 0.5 mol% or more than the S component of the slightly soluble polymer.
A polyester obtained by copolymerizing the components and copolymerizing the S component by 1.5 to 20 mol%, at least a part of the easily soluble polymer is dissolved and removed from the composite fiber, and the depth is 0.3 to 1.8 μm or less, And the entrance width is 0.2~
A method for producing fibers with grooves on the surface, characterized by forming grooves of 4.0μ on the surface. 2. The method for producing fibers with grooves on the surface according to claim 1, wherein the glycol component is a polyalkylene glycol represented by the following formula. A (C _o H _2o O) _n H (A is C _l H _2l+1 O, or OH, l is 1 to 10, n is 2
5, m is 2 to 65) 3. The method for producing a fiber with grooves on its surface according to claim 1 or 2, wherein the composite fiber has an irregular cross-sectional shape. 4. The method for producing a fiber with grooves on its surface according to claim 3, wherein at least a part of the surface-forming portion of the easily soluble polymer occupies the vicinity of the apex of the cross section of the irregularly shaped fiber.