JP2001295132A - Polyester fiber excellent in deepness of color and feeling, mixed filament yarn, and fabric and knit produced by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester fiber having both of an excellent deepness of color and a soft feeling by controlling crystalline and amorphous structure of the fiber. SOLUTION: In a polyester fiber having a principal repeating unit of ethylene terephthalate, the proportion of a long-time component in the longitudinal relaxation time of ethylene glycol unit carbon is >=15% when measured with a solid- state NMR, the degree of exhaustion is >=60% after treated at 100 deg.C for 90 min at a bath ratio of (1:100) in an aqueous solution of Diaceliton Fast Scarlet B (CI Disperse Red1) which is adjusted to the concentration of 0.4 g/L and also the colorfast under exposure to carbon-arc lamp light following JIS L0842 is not lower than Class 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester fiber, and more particularly, to a polyester fiber and a polyester mixed yarn which can be produced at low cost and have excellent darkness and texture.

[0002]

2. Description of the Related Art Polyester fibers are easy to handle, have moderate wear durability, are more advantageous in terms of price than other synthetic fibers, and have an extremely wide use as clothing fibers. However, these polyester fibers also have some disadvantages because of their uniformity. That is, since the surface of the polyester fiber is smooth, it exhibits a slimy and cool touch, and the fine structure is also dense, and since it is hydrophobic, it is difficult for the dye to enter and the paste becomes a pastel color. There is a problem such as lack of darkness.

[0003] Therefore, polyester fibers which are soft, bulging, and have a warm feel like silk or cotton, and polyester fiber products having a deep color such as silk or wool, have been popular from consumers. Is desired.

As a method which has long been known as a method of deepening the color of polyester fibers, a method of roughening the fiber surface (Japanese Patent Publication No. 57-89641, Japanese Patent Application Laid-Open No.
No. 66184, JP-B-59-24233, JP-B-62-6576), but in any of the known techniques, in order to reduce the surface reflected light of light, fine particles are added to the inside of the fiber and alkali is added. There is a problem in operability such as increasing the pressure of the spinning pack and increasing the number of yarn breaks in the spinning process in order to impart unevenness to the fiber surface by weight reduction processing. Furthermore, depending on the particles to be added, there is a problem that troubles due to metal abrasion and troubles due to fluffing and fibrillation of the fabric surface in a later step are likely to occur, which is disadvantageous in cost.

As another method, a method of copolymerizing an acid component such as isophthalic acid or adipic acid (Japanese Patent Application Laid-Open No.
No. 66119) or a method of copolymerizing a polyalkylene oxide-based glycol component such as an ethylene glycol adduct of neopentyl glycol (Japanese Patent No. 250119).
Although any of these methods requires an increase in the amount of the third component to be copolymerized, which increases the cost, the melting point, the heat resistance, and the strength are reduced. Met.

Further, these prior arts mainly focus on the improvement of only the deep color, and are insufficient from the viewpoint of improving the texture.

[0007] Various attempts have been made to improve the texture. For example, two types of latently shrinkable multifilaments with different shrinkage rates are mixed (different shrinkage mixed fibers).
And then heat-treated to give a bulge by heat treatment, or by blending the latently contractible multifilament and the latently extensible multifilament (spontaneous stretching blending) to increase the bulge larger than the heterogeneously shrinkable blended yarn. The method of providing (for example, Japanese Patent Publication No. 60-54404, Japanese Patent Publication No.
JP-A-3-35747, JP-A-1-250425, JP-B-2-293410, JP-B6-299
No. 43, JP-A-8-325878). However, all of these are aimed at improving the texture by simply providing a difference in yarn length, and do not consider the softening of the filament itself and the enhancement of darkness in consideration of the fiber microstructure.

However, in the design of the fabric, both the improvement of the texture and the improvement of the darkness are essential subjects for the polyester fabric for clothing, and it is necessary to control the fiber structure that satisfies the darkness and the texture simultaneously.

[0009]

DISCLOSURE OF THE INVENTION The present invention overcomes the above-mentioned problems of the prior art and controls the crystalline and amorphous structure inside the fiber, thereby obtaining an excellent darkness which could not be obtained conventionally. It is intended to provide a polyester fiber having a soft texture.

[0010]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, polyester which simultaneously satisfies excellent darkness and texture by controlling the fine structure inside the fiber. The inventors have found that a fiber can be obtained, and arrived at the present invention. That is, the present invention has the following configurations. That is, the present invention relates to a polyester fiber whose main repeating unit is ethylene terephthalate,
Polyester fiber excellent in dark color and texture, characterized in that the proportion of long-term components in the longitudinal relaxation time of ethylene glycol unit carbon measured by MR is 15% or more. Specifically, Diaceliton Fast Scarlet B (CI
Disperse Red1) has an exhaustion rate of 60% or more after treatment at 100 ° C. for 90 minutes at a bath ratio of 1: 100 with respect to an aqueous solution adjusted to a concentration of 0.4 g / L, and furthermore, ultraviolet carbon according to JIS L0842. Polyester fiber excellent in darkness and texture as described above, which has a color fastness to an arc lamp of 3 or higher, and a breaking strength of 2.5 to 3.1.
It is a polyester fiber excellent in darkness and texture described above, characterized by having 0 cN / dtex and elongation at break of 70 to 130%. The polyester fiber (A) occupies at least 20% by weight of the total filaments, and the other polyester fiber (B) occupying at most 80% by weight has a yarn length per unit length of the mixed fiber. Is a polyester mixed fiber excellent in darkness and texture, wherein A ≧ B. Furthermore, it is a woven / knitted fabric using the polyester fiber (A) at least in part. Hereinafter, the present invention will be described in detail.

The polyester referred to in the present invention means that the main acid component is terephthalic acid or an ester-forming derivative thereof,
The main glycol component is composed of ethylene glycol, but the acid component is 20 mol% or less of oxalic acid, malonic acid, glutaric acid, adipic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, 2,5-norbornanedicarboxylic acid, etc. Dicarboxylic acids or ester-forming derivatives thereof, phthalic acid, isophthalic acid, 5- (alkali metal) sulfoisophthalic acid, diphenic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid Aromatic dicarboxylic acids such as 1,2-bis (phenoxy) ethane-p, p'-dicarboxylic acid or ester-forming derivatives thereof can also be included as copolymerization components. It may also contain an oxycarboxylic acid such as p- (2-hydroxyethoxy) benzoic acid or an ester-forming derivative thereof in an amount of 20 mol% or less of the acid component.

As the glycol component, 20 mol% or less of propylene glycol, diethylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-
Hexanediol, 1,4-cyclohexanedimethanol, 1,10-decamethylene glycol, 4,4′-dihydroxybisphenol, 1,4-bis (β-hydroxyethoxy) benzene, 2,5-naphthalenediol Glycol to which ethylene oxide is added, polyethylene glycol and the like can be included.

The polyester fiber contains a small amount of any other polymer, an antioxidant, an antistatic agent, a dye-improving agent, a dye, a pigment, a matting agent, a fluorescent whitening agent, and other additives. An agent may be contained.

Next, the fine structure of the polyester fiber, which is the greatest feature of the polyester fiber in the present invention, will be described. That is, when the fiber according to the present invention is measured by solid-state NMR, the proportion of the long-term component in the longitudinal relaxation time of ethylene glycol unit carbon is 15% or more. According to the present invention, even when the proportion of the long-term component becomes 15% or more, the proportion of the short-term component in the longitudinal relaxation time does not particularly decrease. For this reason, it is considered that the structural difference between the amorphous part and the crystalline part increases. The effect of the present invention appears when the proportion of the long-term component in the longitudinal relaxation time of ethylene glycol unit carbon is 15% or more, preferably 17% or more, and more preferably 19% or more. Preferred 15%
It is considered that the reason for the lack of darkness at the time of dyeing and the soft texture cannot be obtained when the density is below is that the density difference between the amorphous part and the crystalline part does not become sufficiently large, so that the diffusion and adsorption of the dye are hindered. .

Further, the polyester fiber of the present invention
0.4g / L of Diaceliton Fast Scarel B (CI Disperse Red1)
100 ° C at a bath ratio of 1: 100 for an aqueous solution adjusted to a concentration of
It is important that the exhaustion rate after treatment for 90 minutes is 60% or more, and if it is less than 60%, the darkness of the fiber is not sufficient even under ordinary polyester dyeing conditions, and it is difficult to achieve the purpose become.

Further, the polyester fiber Diaceliton F
An aqueous solution prepared by adjusting ast Scarel B (CI Disperse Red 1) to a concentration of 0.4 g / L was treated at 100 ° C. for 90 minutes at a bath ratio of 1: 100, and the color fastness to ultraviolet carbon arc lamp light according to JIS L0842 was 3 It is desirable to be higher than grade, and if it is less than third grade, it lacks practicality.

The polyester fiber according to the present invention, which is excellent in darkness and texture, has a breaking strength of 2.50 to 3.0.
It is necessary that the breaking elongation is 10 cN / dtex and the elongation at break is 70 to 130%. If the breaking strength is less than 2.50 cN / dtex, the strength is insufficient and the number of fluffs and thread breakage in the subsequent process increases, which is not preferable.
Conversely, if it exceeds 3.10 cN / dtex, the texture becomes hard, which is not preferable. On the other hand, if the elongation at break is less than 70%,
The relaxing effect is not enough and the texture is inferior. Conversely 130
%, It is not preferable because it tends to be deformed in the post-processing step.

Further, the polyester mixed yarn of the present invention, which is excellent in dark color and texture, has a proportion of a long-term component in the longitudinal relaxation time of ethylene glycol unit carbon of 15% or more as measured by solid-state NMR. (A) occupies at least 20% by weight of the total filaments, and the other polyester fiber (B) occupying at most 80% by weight, the yarn length is preferably A ≧ B, and when A <B, The polyester fiber (A), which is excellent in darkness and texture, does not appear on the surface of the mixed fiber, and is inferior in the appearance and texture of the fabric, which is not preferable.

As described above, the inventors of the present invention pay attention to the fact that the fine structure of the polyester fiber, particularly the difference in density between the crystalline portion and the amorphous portion is larger than that of the conventional polyester fiber. It is, of course, recommended to produce such a novel polyester fiber by a novel method which has not been used before. That is, the polyester fiber excellent in darkness and texture in the present invention is obtained by discharging polyester from a spinneret heated to 260 ° C. to 290 ° C. by a melt-type extruder, and 2,000 m / min to 500
It is obtained by subjecting a highly oriented undrawn yarn drawn at a speed of 0 m / min to a relaxation heat treatment after passing through a drawing step or as it is. The purpose of the relaxation heat treatment is mainly to relax the orientation, and as a method of the relaxation heat treatment, a one-step relaxation heat treatment using a non-contact heater has been mainly performed conventionally. However, in such a method, the orientation was rapidly relaxed, and as a result, sufficient relaxation was not performed. In the present invention, by adopting the method of the two-step relaxation heat treatment, the orientation is moderately and sufficiently relaxed as compared with the conventional method, so that a soft texture with excellent dyeing properties can be obtained. As described in JP-A-8-325878, there has been a concept of a two-stage relaxation heat treatment, but the first-stage relaxation heat treatment is at most 1.5%, and the second-stage relaxation heat treatment is further performed. Has a relaxation rate of at most 2%, which is different from the two-step relaxation heat treatment that we employ. The two-stage relaxation heat treatment referred to here is either a fixed-length relaxation heat treatment on a hot roller (relaxation at the molecular level without a change in yarn length) or a non-contact type heater.
% Or more, and a second step is to perform a relaxation heat treatment of 10% or more using a non-contact type heater. However, when a non-contact type heater is used for both the first stage and the second stage, at least the overfeed ratio of the relaxation heat treatment ground of the first stage must be lower than the overfeed ratio of the second stage.

Another method is to use an organic compound (a so-called carrier) that acts as a plasticizer using the highly oriented undrawn yarn.
By a relaxing treatment in a special liquid stream containing What is important here is that the temperature, relaxation rate or treatment time is appropriately adjusted so as to suppress the birefringence (Δn) of the yarn after the relaxation heat treatment or the liquid flow relaxation treatment to 0.09 or less and the specific gravity to 1.36 or less. It is necessary to set it, and it is important to hinder the orientation of the amorphous part as much as possible and to delay the formation of the crystalline part. As a result, excellent dyeing properties can be obtained and deep coloration can be achieved, and a soft texture can be obtained due to disorder of the molecular chain of the amorphous portion occupying more than half of the polyester.

In the present invention, the organic compound (so-called carrier) which acts on the highly oriented undrawn yarn as a plasticizer includes benzoic acid derivatives such as benzoic acid and benzoic acid esters; salicylic acid derivatives such as salicylic acid and salicylic acid esters;
Phenols such as phenol and m-cresol; halogenated aromatics such as monochlorobenzene and trichlorobenzene; N-alkylphthalimides such as Nn-butylphthalimide and Nisopropylphthalimide; ketones such as acetophenone; halogenated phenols and phenyl Phenols, ethers such as anisole, di- and triphenylmethanes, diphenyl derivatives, naphthalenes such as methylnaphthalene and naphthol, and mainly aromatic organic compound derivatives such as anilines, and in some cases, two or more kinds May be used at the same time.

The solution containing the organic compound that acts as a plasticizer using the highly oriented undrawn yarn may be either an aqueous solvent or an organic solvent solvent. In addition, in addition to these, emulsifiers, scouring agents,
In some cases, various auxiliary agents such as a dispersant, a leveling agent, and a pH buffer and various dyes may be contained.

As a specific example of the case where these are used, 0.1% owf (% on the weight of f.
abric) In addition to the above concentration, the treatment is started at a temperature lower than the glass transition point of the highly oriented undrawn yarn, and the treatment is performed for several minutes in a state where the temperature reaches the glass transition point or higher. A polyester fiber having both excellent darkness and soft texture can be obtained.

These treatments need to be started below the glass transition temperature of the polyester semi-drawn yarn. That is,
When the treatment is started at a temperature equal to or higher than the glass transition temperature, the original yarn shrinks and the elongation does not occur before the shrinkage suppression function by the treatment liquid works. Therefore, many defects occur in the product itself, the texture becomes hard, and no swelling appears. Therefore, the treatment is started at a temperature lower than the glass transition point, the shrinkage is suppressed, and then the temperature is raised to a temperature higher than the glass transition point to elongate. this,
The onset of self-elongation due to the temperature higher than the glass transition point also appears when the temperature is continuously increased in the treatment bath.

The concentration of the organic compound, the treatment temperature, and the treatment time have optimum values depending on the yarn properties and the physical properties of the organic compound, but are not limited thereto.
Considering the processing efficiency, the processing start temperature is desirably as high as possible below the glass transition temperature, thereby shortening the processing time. It is desirable that the organic compound concentration be higher, but if it is higher than 20% owf, there arise problems in compatibility with the solution, safety in the field, cost of the processing solution, and the like. Further, the concentration of the organic compound is 0.1% to the product.
If it is less than% owf, a soft texture cannot be obtained.

[0026]

The present invention will be described below with reference to examples. The method used for the evaluation of the present invention is as follows.

(Relaxation Time) Measurement After the fiber sample was cut into small pieces, the solid-state ¹³ C-NMR spectrum was measured by the CP-MAS method using a Varian XL-300 NMR spectrometer (sample rotation: 3.5 kHz). , C, H 9
0 ° pulse: 4.5 μs, decoupler strength: 55 KH
z, contact time: 2 ms, pulse waiting time: 8
0 seconds). The longitudinal relaxation time is measured using a Torchia pulse sequence. For the decay curve plotting the intensity of the carbon signal in ethylene glycol units versus the relaxation measurement latency, the relaxation times were 2.1, 4.6, 9.8, 2
Assuming that there are nine components of 1, 45, 96, 204, 437 and 933 seconds, their component ratio is determined by the least squares method. 204,437,93 of the relaxation time
The relaxation time indicating 3 seconds is defined as a long time component.

(Dye Exhaust Rate) Measurement 1 g of a fiber sample was collected, and 0.2% of Diaceliton Fast Scarel B (CI Disperse Red 1) was used.
100 g of the aqueous solution adjusted to a concentration of 4 g / L was heated to 100 ° C. in an Erlenmeyer flask using an osmotic dyeing machine, and the sample was charged and treated for 90 minutes. Bath ratio 1:10 using a permeation dyeing machine
The dyeing solution after treatment at 100 ° C. for 90 minutes at 0 was measured with a spectrophotometer, and the dye exhaustion was calculated from the amount of residual dye.

(Dyeing Fastness) A measurement fiber sample treated for measuring the dye exhaustion rate was further treated with 0.5 g of soda ash.
/ L and 0.5 g / L of hydrosulfite were immersed in 100 mL of a solution, treated at 60 ° C. for 10 minutes, washed with hot water, washed with water and dried to prepare a sample for evaluating color fastness.
Using this, a color fastness test to an ultraviolet carbon arc lamp according to JIS L0842 was performed to obtain a color fastness.

(Yarn length) The mixed fiber was cut into a length of 100 mm, and the mixed fiber was separated with great care so as not to deform the constituent fibers, and the length of each fiber was measured.

(Birefringence: Δn) Determined by retardation and fiber diameter using a deflection microscope equipped with a Berek compensator, and evaluated by an average value of n = 5.

(Specific gravity) It was measured at 30 ° C. using a density gradient tube composed of n-heptane and carbon tetrachloride, and evaluated by an average value of n = 3.

(Evaluation of Hand) The dyeing properties and touch of the product were judged by three dyeing technicians who had long experience in the evaluation of hand of polyester fabric.

[0034]

(Example 1) Highly oriented non-woven fabric obtained by melt spinning using polyethylene terephthalate having terephthalic acid as a carboxylic acid component and ethylene glycol as a glycol component at a spinning temperature of 275 ° C and a take-up speed of 3100 m / min. After drawing the drawn yarn through a hot roller at 80 ° C. and drawing it 1.7 times, the non-contact first heater at 170 ° C. and 20
12.0% and 35.2 respectively by a second heater at 0 ° C.
A two-stage relaxation heat treatment is performed at a speed of 500 m / min at an overfeed rate of 0%, and at the same time, the fiber is mixed with a high shrinkage yarn having a shrinkage rate of 20% at 160 ° C for 30 minutes, and 90 dtex 3
A mixed filament of 0 filament was obtained.

The multifilament obtained at the same time was
A SZ twist of 00 turns / m was applied, and this was used as a warp and a weft to form a woven fabric having a flat structure in which these were alternately driven. The obtained woven fabric was subjected to ordinary scouring, dry heat relaxation, and presetting. The mixture was treated with a 50 g / L caustic soda solution at 100 ° C. to reduce the weight by 20% by weight.

Thereafter, the final set (1
(70 ° C. × 30 seconds) to obtain a finished cloth. It is rich in softness and swelling, and is dyed deeper by further dyeing.

(Example 2) A non-contact type first heater at 200 ° C and a speed 54 at an overfeed rate of 40.0% were used.
160 ° C. at the same time as performing one-step relaxation heat treatment at 0 m / min.
Mixed with high shrinkage yarn with shrinkage of 20% during 30 minutes treatment, 9
A fabric was obtained in the same manner as in Example 1 except that a mixed fiber of 0 decitex and 30 filaments was obtained. It is rich in softness and swelling, and is dyed deeper by further dyeing.

Example 3 A spinning temperature of 275 ° C. was obtained using polyethylene terephthalate having terephthalic acid as a carboxylic acid component and ethylene glycol as a glycol component.
After passing through a preheating roller at 100 ° C, the highly oriented undrawn yarn obtained by melt-spinning at a take-up speed of 3000 m / min is passed through a 170 ° C
And the first non-contact heater and the second non-contact heater heated to 200 ° C. are subjected to a two-stage relaxation heat treatment at an overfeed rate of 5.0% and 12.0% at a speed of 450 m / min, respectively, to obtain 78 dtex. Obtain an 18 filament multifilament at 160 ° C, 30
190% by mixing with high shrinkage yarn with shrinkage of 20%
A fabric was produced in the same manner as in Example 1, except that a mixed fiber of 48 decitex filaments was obtained. It is rich in softness and swelling, and is dyed deeper by further dyeing.

(Example 3) A polyethylene terephthalate having terephthalic acid as a carboxylic acid component and ethylene glycol as a glycol component was used at a spinning temperature of 275 ° C.
A highly oriented undrawn yarn of 33 decitex 18 filaments obtained by melt spinning at a take-up speed of 3000 m / min.
A high shrinkage yarn having a shrinkage rate of 20% at 30 ° C. for 30 minutes is subjected to fluid entanglement blending using a tangling nozzle, and a twist of 300 times / m is given to the obtained 90-decitex 30-filament blended yarn. Using the S-twisted yarn and the Z-twisted yarn, two of these were alternately punched into a flat-textile fabric, and the obtained fabric was subjected to the following treatment.

The above-mentioned woven fabric was prepared by using a carrier, tetrocin OEN, containing ortho-phenylphenol as an organic compound which acts as a plasticizer with the highly oriented undrawn yarn.
(Yamakawa Pharmaceutical Co., Ltd.) was dispersed at a concentration of 1 g / L (corresponding to an organic substance concentration of about 4% owf) and put into a prepared emulsion processing solution (bath ratio 1:25), and processed with a jet dyeing machine. Starting at a temperature of 30 ° C., the temperature was raised at a rate of 1 ° C./min with stirring, the bath temperature was raised to 100 ° C., and then 1 ° C.
The mixture was stirred at 00 ° C. for 45 minutes, cooled and taken out.
After the treatment, drying was performed. Furthermore, after a normal presetting (180 ° C. × 45 seconds) performed with a polyester fabric, 5
It was treated with a caustic soda solution at 0 g / L and 100 ° C. to reduce the weight by 20% by weight.

Thereafter, this fabric was treated with a disperse dye (Resolin Red Purple) having a bath ratio of 1:15 and a dye concentration of 4.0% owf.
FBL200: Dystar Japan KK) at 100 ℃, 3
Stain for 0 minutes, then final set (170 ° C x 3)
0 second) to obtain a finished cloth. It was dyed in a dark color, and was rich in softness and swelling.

(Comparative Example 1) Using a polyethylene terephthalate having terephthalic acid as a carboxylic acid component and ethylene glycol as a glycol component, a spinning temperature of 275 ° C was used.
The undrawn yarn obtained by melt-spinning at a take-up speed of 1500 m / min is passed through a hot roller at 80 ° C. and a hot plate at 150 ° C. and stretched 3.1 times to obtain 33 dtex 1
Example 1 Except that after obtaining a drawn filament of 8 filaments, it was mixed with a high shrinkage yarn having a shrinkage of 20% at 160 ° C. for 30 minutes to obtain a mixed filament of 30 filaments of 90 decitex.
A fabric was obtained in the same manner as described above. The fabric lacked swelling and lacked softness. It was not dyed dark when dyed.

(Comparative Example 2) Using polyethylene terephthalate having terephthalic acid as a carboxylic acid component and ethylene glycol as a glycol component, a spinning temperature of 275 ° C was used.
The unstretched yarn obtained by melt-spinning at a take-up speed of 3000 m / min is passed through a hot roller at 80 ° C. and a hot plate at 150 ° C. and stretched 1.7 times to obtain 33 dtex 1
Example 1 Except that after obtaining a drawn filament of 8 filaments, it was mixed with a high shrinkage yarn having a shrinkage of 20% at 160 ° C. for 30 minutes to obtain a mixed filament of 30 filaments of 90 decitex.
A fabric was obtained in the same manner as described above. The fabric lacked swelling and lacked softness. It was not dyed dark when dyed.

Comparative Example 3 A fabric was obtained in the same manner as in Example 3 except that the cloth was treated with a solution containing no carrier. The fabric was low in darkness and poor in swelling and softness.

(Comparative Example 4) A non-contact type first heater at 200 ° C with an overfeed rate of 40.0% and a speed of 540 m /
Example 1 except that the fiber was mixed with a high shrinkage yarn having a shrinkage rate of 20% at 160 ° C. for 30 minutes at the same time as performing a one-step relaxation heat treatment at a temperature of 30 minutes to obtain a mixed yarn of 90 dtex 30 filaments. A fabric was obtained by the same method. The fabric was slightly insufficient in both darkness and swelling.

[0046]

[Table 1]

[0047]

According to the present invention, it is possible to provide a polyester fiber which is excellent in darkness, and has a fullness and softness.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) D04B 1/16 D04B 1/16 21/00 21/00 B D06P 3/54 D06P 3/54 (72) Inventor Yoshika Sakaguchi Mitsuru 2-1-1 Katata, Otsu-shi, Shiga F-term in Toyobo Co., Ltd. Research Laboratory (reference) 4H057 AA01 DA01 DA17 DA30 GA07 4L002 AA07 AB02 AC02 AC06 EA00 4L035 BB33 BB89 BB91 CC02 CC07 DD15 DD17 EE08 EE20 FF10 4L0 MA0 PA01 PA03 PA33 RA03 UA01 UA16 4L048 AA21 AA42 AA47 AA50 AB09 AB15 AC07 BA01 BA02 CA00 CA12 CA13 EB04 EB05

Claims (6)

[Claims] 1. A polyester fiber whose main repeating unit is ethylene terephthalate, and a solid NM
A polyester fiber excellent in darkness and texture, wherein the proportion of a long-term component in the longitudinal relaxation time of ethylene glycol unit carbon measured by R is 15% or more. 2. The Diaceliton Fast Scarlet B (CI Dispers
e Red1) to an aqueous solution adjusted to a concentration of 0.4 g / L with a bath ratio of 1: 1.
The exhaustion rate after treatment at 100 ° C. for 90 minutes at 00 ° C. is 60% or more, and the color fastness to ultraviolet carbon arc lamp light according to JIS L0842 is 3 or more. Polyester fiber having excellent darkness and texture as described. 3. The ratio of long-term components in the longitudinal relaxation time of ethylene glycol unit carbon measured by solid-state NMR is 1
2. The polyester fiber according to claim 1, which is 8% or more. 4. A breaking strength of 2.50 to 3.10 cN / dte
The polyester fiber having excellent darkness and texture according to claim 1, wherein x and the elongation at break are 70 to 130%. 5. The polyester fiber (A) according to claim 1,
Represents at least 20% by weight of the total filaments and at most 80% by weight of the other polyester fiber (B)
In contrast, a polyester mixed fiber yarn having excellent darkness and texture, wherein the yarn length per unit length of the mixed fiber is A ≧ B. 6. The polyester fiber (A) according to claim 1,
A woven or knitted fabric using at least a part thereof.