JPS6339686B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyester staple for wool blends, and more specifically to a modified polyethylene terephthalate fiber for wool blends that has excellent dyeability and anti-pilling properties and has improved process passability. be. Traditionally, knitted fabrics made of wool have been widely used due to their excellent properties such as texture, gloss, and color tone, but on the other hand, they have poor dimensional stability, wrinkle resistance,
Functional performance, such as wash and wear characteristics, was not always sufficient. Therefore, in order to eliminate the functional defects of wool, a method of blending polyester fiber with synthetic fiber, particularly polyester fiber, has been adopted industrially for the purpose of imparting superior functions to polyester fiber. Polyester fibers are 100% polyester, and polyester mixed with rayon have almost satisfactory properties. However, the problems of carrier pollution due to the various properties required for wool blends, such as poor high-order processability or poor dyeability,
Furthermore, the product had drawbacks such as poor anti-pilling properties. Later, polyesters with improved anti-pilling properties and dyeability were proposed, and although these drawbacks were alleviated to some extent, desirable characteristics as wool-mixed materials still remain. Polyester that has all of these properties has not yet been obtained. Therefore, the reality is that its use in these fields is naturally limited. In addition, polyester fibers could not be dyed sufficiently deep unless they were dyed at high temperatures or carrier dyed. That is, since it is difficult to dye with dyes other than disperse dyes and azoic dyes, it has been difficult to obtain clear and deep hues. In order to solve this drawback, various types of polyester fiber dyeable with basic dyes, as typified by Japanese Patent Publication No. 34-10497, have been proposed, and as a result, it has become possible to use basic dyes with excellent clarity. However, commercially available polyester fibers that can be dyed with basic dyes are non-carrier and cannot be dyed to a sufficiently deep color at temperatures below 100°C, so high-temperature dyeing or so-called carrier dyeing, which uses a carrier, is generally carried out. There is. When performing high-temperature dyeing, not only is an expensive high-pressure dyeing machine required, but also fibers with poor heat resistance, especially when blended with wool, high-temperature dyeing of over 110°C can significantly deteriorate the wool. Therefore, it is necessary to dye at a temperature of 105°C or lower, preferably 100°C or lower. But 100℃
It was not possible to dye the above-mentioned polyester fibers at dyeing temperatures below. On the other hand, when carrier dyeing is adopted, the working environment is deteriorated due to carrier odor, and it is necessary to install or enhance wastewater treatment facilities to prevent carrier pollution. Furthermore, the use of a carrier not only increases costs, but also has the disadvantage that it is difficult to remove the carrier after dyeing, especially in the case of wool blend products. In order to obtain better dyeability, for example,
The method disclosed in Publication No. 10497, in which a large amount of ethylene 5-sodium sulfoisophthalate units is contained, allows dyeing to a deep color with a basic dye at 100°C or lower without using a carrier, but on the other hand, It has become clear that due to the insufficient strength of the raw cotton produced, there are various drawbacks such as frequent thread breakage during spinning, insufficient strength of the product, and a decline in product quality due to poor spinning properties. Therefore, the current commercially available modified polyester fibers are commercially available with approximately 2.5 mol% of ethylene 5-sodium sulfoisophthalate units applied thereto. On the other hand, some polyester fibers that are non-carrier atmospheric pressure dyeable with disperse dyes are commercially available, but polyester fibers that are non-carrier atmospheric pressure dyeable with disperse dyes have the following fatal defects. That is, the fastness of the dyed product is poor. Generally speaking, the easier it is to dye with disperse dyes, the easier the dye will come off. In particular, the fastness when wet is significantly reduced, resulting in poor commercial value. Dyeing waste liquid becomes polluted. Dyeing with disperse dyes leaves a large amount of dye in the residual solution after dyeing, which poses a problem of contamination of wastewater. This tendency is particularly noticeable in dark colors, and the purpose of purifying wastewater, which is one of the advantages of non-carrier atmospheric dyeing, cannot be achieved. Dyeing costs are high. Disperse dyes have a high unit price, and unlike basic dyes, they are not completely exhaustion type, so they require a large amount of dye to be used. The object of the present invention is to solve the drawbacks of the wool-blended polyester fiber obtained by the above-mentioned known technology, namely (1)
(2) Low productivity in higher-order processing steps; (3) Satisfying both higher-order processability and imparting anti-pilling properties to the product. The object of the present invention is to obtain a polyester fiber which can eliminate the disadvantage of being difficult to dye and which can sufficiently satisfy the characteristics of good dyeability, high productivity, and final products. In other words, to provide a wool-blended polyester fiber that can be dyed with a basic dye using non-carrier pressure and has high productivity in each step of spinning, spinning, weaving, and knitting, and can sufficiently maintain the texture and functionality of the final product. There is a particular thing. That is, the present invention consists of a polyethylene terephthalate fiber in which 4.0 to 5.5 mol% of the total structural units are ethylene 5-sodium sulfoisophthalate and a relative viscosity of 8.6 to 11.5, and the fiber can be processed without using a carrier. Dyeing is possible at temperatures below 98°C, and the tensile strength T (g/d) and tensile elongation E of raw cotton are
(%), bending strength K (times), fineness D (denier), average fiber length L (mm), composition ratio of fiber length distribution, and crimp number C (crest/25 mm), and the characteristics between each characteristic value. This is a highly dyeable wool blended polyester fiber that satisfies the following formulas (1) to (7). 3.2T (1+E/100) 4.6 (1) 150T−250K150T+250 (2) 2.3D5.2 (3) 7.4L105 (4) 0.23N ₁ 0.58 (5) 0.48N ₂ 0.89 (6) 16.5−0.5D−L/ 15C20.5−0.5D−L/15 (7) (where N ₁ : Ratio of the number of fibers with a fiber length of L±0.03L to the total number of fibers N ₂ : L±0.06L to the total number of fibers The first feature of the modified polyester fiber according to the present invention is that the exhaustion rate of malachite green, which is a basic dye, is 45% or more at 98°C without using a carrier. . If the pressure-dyeable polyester fiber is not a type that can be dyed with basic dyes, but is dyed with non-ionic dyes such as disperse dyes, as mentioned above, the dyed product may have poor fastness, wastewater pollution from dyeing residue, and dyeing costs. It is too high to be of practical use. In addition, even ionic dyes that are dyeable with acidic dyes have drawbacks such as increased dyeing costs, which is not preferable. The exhaustion rate of malachite green, a basic dye employed in the present invention, is 98% without using a carrier.
If it is less than 45% in °C, sufficiently deep colors cannot be obtained in various hues. In particular, not only is the black color development insufficient, which is undesirable, but also the color development is insufficient even in light colors, which is undesirable. In order to satisfy these dyeing properties, it is necessary to
It is necessary to copolymerize 4.0 mol% or more of ethylene 5-sodium sulfoisophthalate. However, if the amount exceeds 5.5 mol%, the dyeability will almost reach the saturation point, resulting in a cost disadvantage and a significant increase in the melt viscosity of the modified polymer, resulting in problems such as difficulty in spinning. be. The second feature of the present invention is that the relative viscosity is in the range of 8.6 to 11.5, and the tensile strength T (g/d), tensile elongation E (%), bending strength K (times), and fineness D (denier) of the raw cotton are in the range of 8.6 to 11.5. ,
Wool-blended polyester fiber that satisfies the following formulas (1) to (7) between the characteristic values of the average fiber length L (mm), the composition ratio of the fiber length distribution, and the number of crimp C (peaks/25 mm), and the relationship between each characteristic value. It is to be. 3.2T (1+E/100) 4.6 (1) 150T-250K150T+250 (2) 2.3D5.2 (3) 74L105 (4) 0.23N ₁ 0.58 (5) 0.48N ₂ 0.89 (6) 16.5-0.5D-L/15C20 .5−0.5D−L/15 (7) (where N ₁ : Ratio of the number of fibers with a fiber length of L±0.03L to the total number of fibers N ₂ : Ratio of the number of fibers with a fiber length of L±0.06L to the total number of fibers If the relative viscosity (ηr) is lower than 8.6, productivity such as spinning, spinning, knitting, and weaving properties will not only decrease significantly, but also the quality of the resulting product will deteriorate. This is undesirable because product properties such as insufficient strength and increased wear loss occur. On the other hand, if the relative viscosity (ηr) is higher than 11.5, it is undesirable because it results in poor thread-spinning properties due to an increase in melt viscosity and poor anti-pilling properties in products, especially knitted fabrics. Also when blending polyester fiber with wool, it is essential that the processability and product properties are good. For this reason, first of all, the compatibility between polyester fiber and wool is very important for higher processability, and if the compatibility is insufficient, higher processability will be poor, which will not only reduce productivity but also reduce product quality. . The conformability of wool is mainly related to fineness, fiber length, shrinkage number, etc., and it goes without saying that these properties must be within a certain range, but this alone is not sufficient. In short, the overall balance of these characteristics is important. Furthermore, it is necessary for the raw cotton to be able to withstand carding in high-order processing processes, spinning winding tension, warping in weaving preparation, etc., and in order to satisfy this, tensile strength, tensile elongation at break, and bending are necessary. Unless the strength and other properties are within the limited range defined in the present invention, good high-order processability and good product properties cannot be obtained. If T (1 + E / 100) is lower than 3.2, it is preferable because it leads to a decrease in productivity such as spinning properties, spinnability, knitting properties, and weavability mainly due to thread breakage, and a decrease in product properties such as an increase in the tensile strength of the product and an increase in abrasion loss rate. do not have. If T(1+E/100) is higher than 4.6, the pill resistance of the product will be poor, and especially in knitted fabrics, the commercial value will be significantly lowered, which is not preferable. It is well known that tensile strength generally greatly affects productivity, and flexural strength generally largely affects pill resistance, but also affects knitting properties. Therefore, in order to provide anti-pilling properties while further improving productivity, it is desirable that the tensile strength is high, and the bending strength must be limited to a specific range. In other words, if the bending strength K is lower than 150/T-250, the pill resistance is good but the knitting properties are poor, and the resulting product has a whitish appearance (so-called floss) because the fibers become fibrillated due to friction. This phenomenon occurs and reduces the product value. On the other hand, if the bending strength K is greater than 150·T+250, the anti-pilling properties will be significantly deteriorated, and this tendency will be particularly poor in knitted fabrics, which is not preferable. If the fineness D is smaller than 2.3d, the quality of the spun yarn will deteriorate due to yarn breakage and neps during spinning. Fineness D
If it is larger than 5.2d, it becomes difficult to achieve uniform mixing during blending, resulting in increased mixing unevenness and thickness unevenness in the length direction of the fibers, which is not preferable. The shrinkage number is one of the important raw cotton characteristics in the spinning process, especially in the pre-spinning process. In addition, the number of shrinkages is closely related to the fineness and fiber length of raw cotton, and generally, the thicker the fineness and the longer the fiber length, the smaller the number of shrinkages is desirable. Furthermore, in the case of raw cotton with a low degree of polymerization, physical properties change easily due to damage to the buckled portion due to crimp, and sufficient management of crimp characteristics is required. The purpose of the raw cotton of the present invention cannot be achieved without controlling it within a very narrow range. The appropriate range of the Ken reduction number obtained as a result of intensive studies by the present inventors needs to satisfy the above-mentioned formula (7). If the Ken contraction number C is less than 16.5-0.5D-L/15, the intertwining of the fibers will be insufficient especially in the pre-spinning process, resulting in uneven thickness of the spun yarn, weak yarn, and even yarn breakage during spinning. This is undesirable. If the Ken reduction number C is more than 20.5-0.5D-L/15, excessive entanglement will occur, which will also cause unevenness in the thickness of the spun yarn and a decrease in the strength of the raw cotton. If the average fiber length L is shorter than 74 mm, the strength of the spun yarn will be insufficient, and this tendency is particularly noticeable with low-strength raw cotton. On the other hand, if the average fiber length L is longer than 105 mm, there will be restrictions on the spinning equipment that can be used, resulting in a lack of versatility, and there will also be restrictions on the wool that can be used when blended with wool, which is undesirable. Furthermore, it is desirable that the fiber length be distributed within a specific range in order to improve spinnability and reduce uneven thickness and strength of the spun yarn, and when blended with fibers such as wool that have a wide fiber length distribution. is especially necessary. One method for obtaining fibers having such a suitable fiber length distribution will be explained with reference to FIG. Figure 2 is a front model diagram of the yarn cutter. The fiber bundle F consists of a rotating yarn wheel W and a prong P that interlocks with the yarn wheel W.
gripped between. The grooves C on the yarn wheel have angles of θ ₁ and θ ₂ with respect to the circumferential direction of the yarn wheel W, and θ ₁ and θ ₂ are alternate, and θ ₁ <
90°, and θ ₂ >90°. The cutting knife operates along the groove C and cuts the fiber bundle F. The fiber length distribution model thus obtained is shown in FIG. In Figure 1, the fibers are arranged at the same fiber number density in descending order of fiber length. The ratio of the number of fibers within the range of L+0.03L and L-0.03L to the total number of fibers is indicated by _N1 . As a result of intensive studies by the present inventors, it is desirable that the fiber length distribution most suitable for wool blends satisfies the above-mentioned formulas (5) and (6). When N ₁ is less than 0.23 and when N ₂ is less than 0.48, it is virtually the same as when the fiber length is constant;
No effect on fiber length distribution was observed, resulting in poor spinnability.
Weak threads occur and thickness unevenness increases. On the contrary, N ₁
When N 2 exceeds 0.58 and when N ₂ exceeds 0.89, problems occur frequently during spinning because a distribution with a large number of overlong fibers is produced. The polyester fiber obtained by the present invention overcomes the basic defect of polyester fibers, which is poor dyeability, by making it possible to dye with basic dyes at normal pressure without using a carrier, and by improving wet fastness, which was a conventional drawback. It was possible to eliminate gender issues. Since it is raw cotton that can be dyed at 98°C or lower without using a carrier, in addition to mixing polyester and wool, any other fibers may be blended, twisted, woven, or knitted, such as polyurethane fibers, The effect is remarkable in fibers with poor heat resistance such as polyacrylonitrile fibers. Copolymerizing 4.0 to 5.5 mol % of ethylene 5-sodium sulfoisophthalate provides good dyeing properties and contributes to improving the melt viscosity of the polymer. Such a specific copolymerization rate according to the present invention improves the spinnability of the low polymerization degree polyester and provides suitable anti-pilling properties. Furthermore, as specified in the present invention, the raw cotton characteristics must satisfy all of the characteristic values of fineness, strength, elongation, bending strength, crimp characteristics, and fiber length, and the interrelationships among these characteristics. It has a remarkable effect on improving the spinnability of polyester/wool blends and improving the quality and feel of the spun yarns, as well as the fabrics obtained from the spun yarns, which could not be achieved conventionally. The polyethylene terephthalate of the present invention has ethylene 5-sodium sulfoisophthalate units, and can be produced by direct polymerization, transesterification, or
Of course, either EO method may be used. The polyethylene terephthalate may contain constitutional units other than ethylene terephthalate units and ethylene 5-sodium sulfoisophthalate units within a range of 5 mol % or less, if necessary.
Specifically, aliphatic dicarboxylic acids such as adipic acid, sebacic acid, and dodecanoic acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, and aromatic dicarboxylic acids such as isophthalic acid and 2,6-naphthalene dicarboxylic acid. , butylene glycol, aliphatic diol such as neopentyl glycol, 1,4-
Alicyclic diols such as cyclohexanedimethanol, xylylene glycol, 2,2-bis(β-
Examples include structural units from aromatic diols such as hydroxyethoxyphenyl)propane, oxycarboxylic acids such as 4-β-hydroxyethoxybenzoic acid, and polyoxyalkylene glycols such as polyethylene glycol. In addition, in the transesterification method, it is preferable to use one or more compounds selected from the group consisting of alkali metal compounds, manganese compounds, cobalt compounds, and zinc compounds as transesterification catalysts. It is particularly preferred in terms of further reducing the thickening during melting that is thought to be caused by the eumusulfoisophthalate unit. The raw cotton of the present invention can be produced by a conventional polyester melt spinning method. In other words, when polymerizing a polymer, dimethyl terephthalate, dimethyl sodium sulfoisophthalate, and ethylene glycol are added to transesterify the polymer, followed by polymerization under highly reduced pressure to reduce the relative viscosity.
When the temperature reaches 8.6 to 11.5, it is taken out from the polymerization can, cooled, and turned into a granular polymer mass. The resulting polymer mass is dried under reduced pressure, and melt-spun is performed by determining the discharge amount so that it has a specified fineness D and extruding it from the spinneret hole.
Pulling is done at a drawing speed of 1000m/min. The collected fibers are made into fiber bundles of approximately 500,000 D, stretched in a liquid bath, and then crimped in a crimping machine to have specified crimping properties. Perform heat fixation. After heat setting, the necessary finishing oil is applied and the fibers are cut using a cutter having the principle shown in FIG. 2, for example, so that the average fiber length and fiber length distribution are within the specified range. The obtained raw cotton is blended with wool in an appropriate proportion and in an appropriate process as required, and then spun in a conventional manner to obtain spun yarn. After spun yarn, knitting, and weaving, it is non-carrier and dyed at 98℃ or below. Note that any commonly used melt spinning may be used for spinning, and undrawn yarn may be obtained at a take-up speed of 1500 m/min or less, and so-called POY (pre-oriented yarn) may be obtained at a take-up speed of 1500 m/min or more. ). Furthermore, even if direct spinning and drawing is performed, the effects obtained by the present invention will not change. The stretching method may be liquid bath, steam or pin stretching.
After stretching, any heat treatment such as moist heat, drying, tensioning, fixed length, and relaxation may be performed. The obtained drawn yarn is crimped, but in this case it may be heated with steam before crimping. Furthermore, it is of course possible to heat-set at 80 to 140°C after imparting shrinkage, or it is also possible to simply dry at 50°C or lower to obtain a highly shrinkable raw cotton with a boiling yield of 5 to 30%. The finishing oil may be applied at any step after stretching. Furthermore, the method for cutting the fiber bundle may be any method other than the cutter having the principle shown in FIG. 2, as described above, as long as it has a specified average fiber length and fiber length distribution. The present invention will be specifically explained below with reference to Examples. In addition, the measurement method of each characteristic in an Example is as follows. (Bending strength (times)) Two single fibers are looped so that they cross at a 60° angle.
Apply a load of 200 mg/d to the crossed upper thread, reciprocate the lower thread by 30 degrees, and calculate the number of reciprocations until either the upper or lower thread breaks. (Relative viscosity: ηr) 8 g of polymer is dissolved in 100 ml of orthochlorophenol at 100° C. over 1 hour. The viscosity of this polymer solution and the viscosity of orthochlorophenol itself are measured in the same unit at 25°C and expressed as a ratio. (MG exhaustion rate (%)) Sample fibers from which the attached oil was removed by the usual scouring method were dyed with malachite green dye (referred to as MG) 5% owf, dyeing solution PH5, bath ratio 1:100. The dye was dyed under conditions of heating and refluxing the solution (98°C) and shaking under normal pressure for 60 minutes, and after thorough washing with water, the dyeing method was dissolved in orthochlorophenol and its absorbance was measured to determine the exhaustion rate. . If the MG exhaustion rate is 45% or more, it can be said that dyeing can be sufficiently dark at 98°C. Example 1 For polyethylene terephthalate unit,
Discharge amount of 348g/modified polyethylene terephthalate with a relative viscosity of 9.6, which is obtained by copolymerizing 4.8 mol% ethylene 5-sodium sulfoisophthalate.
An undrawn yarn was obtained using a nozzle with a hole diameter of 0.28 mmφ and 360 holes at a take-up speed of 1000 m/min. This undrawn yarn was bundled to 600,000 denier, then stretched to 3.36 times in a liquid bath at a drawing temperature of 75°C, crimped with 11 to 12 ridges/25 mm in a stuffing box, and then stretched at 125°C for 20 Heat set for a minute. Thereafter, a finishing oil was applied, and the fibers were cut using a variable cutting method that gave a distribution to the fiber length. This raw cotton and wool were mixed in a drawing process at a weight ratio of 1:1, and the resulting polyester/wool blend yarn was dyed with cheese at 95°C and knitted into a women's sweater. The raw cotton properties, process passability, and product properties are shown in Table 1. As is clear from Table 1, the obtained raw cotton was satisfactory as a wool blended polyester. Examples 2 and 3 Example 1 except that the copolymerization rate of ethylene 5-sodium sulfoisophthalate was changed as shown in Table 1.
Polymerized yarn spinning was carried out under exactly the same conditions as above to obtain the raw cotton shown in Table 1. This raw cotton was made into a women's sweater in the same manner as in Example 1. As shown in Table 1, the results were fully satisfactory in terms of process passability and product characteristics. Comparative Examples 1 and 2 Ethylene 5-sodium sulfoisophthalate was 3.2 mol% in Comparative Example 1 and 6.0 mol% in Comparative Example 2, and the stretching ratio was 3.62, respectively.
Polymerization, spinning and spinning were carried out under the same conditions as in Example 1, except that the conditions were changed to 3.06 and 3.06. The results are in Table 1
It was shown to. When the ethylene 5-sodium sulfoisophthalate component was 3.2 mol %, the MG exhaustion rate was as low as 3.5%, and a dark dyed product could not be obtained.
In addition, the clarity was significantly inferior to that of Example 1, and the difference in dyeing from wool was large, resulting in uneven dyeing and significantly lower commercial value. As a result of attempting dyeing at 120°C, although the black dyeing was achieved well, the wool deteriorated significantly. On the other hand, products containing 6.0 mol% of ethylene 5-sodium sulfoisophthalate have excellent dyeing properties but have low strength, frequently breakage of single threads during the spinning process, and There were many single thread breaks. Comparative Examples 3 and 4 Reeling, spinning, dyeing and A women's sweater was knitted under the same conditions as in Example 1. The results are shown in Table 1. Here, in Comparative Example 3, there were frequent occurrences of dripping and single yarn breakage during spinning, as well as frequent yarn breakage during spinning during the spinning process, resulting in extremely poor process passability.
The wear resistance of the product was also poor. On the other hand, in Comparative Example 4, although the processability was good, there were many pills in the product, which significantly impaired the commercial value. Comparative Examples 5 and 6 In Comparative Example 5, the mouth hole diameter was 0.23 mmφ, the number of holes was 450,
Yarn spinning and spinning were carried out in the same manner as in Example 1, except that the discharge rate was changed to 321 g/min and the draw ratio was 3.21, and in Comparative Example 6, the mouth hole diameter was 0.23 mmφ, the number of holes was 180, the discharge rate was 370 g/min, and the draw ratio was changed to 3.63. , dyed and organized. The results are summarized in Table 1. In Comparative Example 5, there were frequent drips and single yarn breakages during yarn spinning, and there were also many yarn breakages during the spinning process, and in particular, many uneven yarns with neps were observed. Comparative Example 6
Although there were no problems in spinning, there were frequent troubles during spinning, especially yarn breakage during roving and spinning, which appeared to be due to non-uniform mixing in the drawing, and the quality of the product was poor. Comparative Examples 7 to 12 From the drawn yarn obtained in Example 1, raw cotton of Comparative Examples 7 to 12 was prepared and evaluated, in which the fiber length, fiber length distribution, and number of crimps were changed as shown in Table 1. the result,
In Comparative Example 7, there were many net-like parts, and the roving and
There were many thread breakages during spinning, and in Comparative Example 8, drawing
Thickness unevenness occurred frequently in the roving and spinning draft parts, and in Comparative Example 9, thread breakage occurred frequently in the spun yarn, resulting in thickness unevenness. In Comparative Examples 10 and 11, yarn breakage and scattering of single fibers occurred frequently in the spinning draft section, in Comparative Example 12, yarn breakage due to snakes occurred frequently in each spinning process, and in Comparative Example 13, yarn breakage occurred frequently due to snakes in each spinning process. This occurred frequently, the thickness became uneven, and the spun yarn frequently broke. As described above, fibers whose fiber length, fiber length distribution, and number of crimps are outside the scope of the present invention frequently cause troubles in the spinning process, and various problems such as non-uniform mixing and uneven thickness occur. 【table】

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram for explaining fiber length distribution.
FIG. 2 is a front model view of a variable cutter for obtaining a suitable fiber length distribution defined by the present invention.

Claims (1)

[Claims] 1. 4.0 to 5.5 mol% of all structural units is ethylene 5-
Sodium sulfoisophthalate is made of polyethylene terephthalate fiber with a relative viscosity of 8.6 to 11.5, and the fiber can be dyed at 98°C or lower without using a carrier, and the tensile strength T (g /d), tensile elongation E (%), bending strength K (times), fineness D (denier), average fiber length L (mm),
Composition ratio of fiber length distribution and number of crimp C (crest/25mm)
A highly dyeable wool-blend polyester fiber that satisfies the following formulas (1) to (7) between each characteristic value and each characteristic value. 3.2≦T(1+E/100)≦4.6 …(1) 150T−250≦K≦150T+250 …(2) 2.3≦D≦5.2 …(3) 74≦L≦105 …(4) 0.23≦N ₁ ≦0.58 ……(5) 0.48≦N ₂ ≦0.89 ……(6) 16.5−0.5D−L/15≦C≦20.5−0.5D−L/15
...(7) [Here, N ₁ : Ratio of the number of fibers having a fiber length of L±0.03L to the total number of fibers N ₂ : Ratio of the number of fibers having a fiber length of L±0.06L to the total number of fibers ]