JP2003301328A - Easily dyeable polyester fiber and method for producing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester fiber having an excellent normal pressure dyeability. <P>SOLUTION: This polyester fiber is characterized by having copolymerized amounts S and P satisfying formula (1): S×P≥9.5, by taking the copolymerized amount of 5-sodium sulfoisophthalic acid component or 5-lithium sulfoisophthalic acid component based on the total acid components in the polyester as S mol % and the copolymerized amount of a glycol component as P wt.% (wherein, 2≤P≤7), and having 100×10<SP>-3</SP>-140×10<SP>-3</SP>birefringence. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester fiber having an easy dyeing property, and more specifically, a polyester having an atmospheric dyeing property which cannot be realized by conventional polymer modification only by polymer modification and fiber orientation suppression. It is about fibers.

[0002]

BACKGROUND OF THE INVENTION Polyester fibers are the most widely used synthetic fibers for industrial materials and clothing because of their excellent physical and chemical properties.

However, polyester fibers have the drawback of being poor in dyeability, and dyeing with dyes other than disperse dyes is difficult. For this reason, it is difficult to use it in combination with a synthetic fiber or a natural fiber which is easily contaminated with a disperse dye, which is a factor limiting the application. In order to improve such defects, many methods for modifying and improving polymers have been proposed in the past. To give a typical example,
(1) A method of copolymerizing a metal sulfonate group-containing material with polyester (Patent Document 1), (2) A method of copolymerizing a glycol component having a molecular weight of 90 to 6000 in addition to the metal sulfonate group-containing material (Patent Document 2), 3) A method of copolymerizing an amino group-containing compound (Patent Document 3) and the like have been proposed.

However, all of the methods have drawbacks. For example, in (1), a large amount of metal sulfonate group-containing compound must be copolymerized in order to obtain sufficient dyeability. In the copolymerization of a sulfonate group-containing compound, the melt viscosity of the copolyester is remarkably increased due to the thickening effect of the metal sulfonate group-containing compound, and it is difficult to increase the degree of polymerization of the copolyester to a level required for fibers. Spinning also becomes difficult. Therefore, if the melt viscosity is lowered to a level at which polymerization and yarn production are possible by this method, only fibers having low strength can be obtained. Also, (2) is
Due to the effect of reducing the viscosity of the glycol component, a polyester fiber having a relatively higher strength than that of (1) can be obtained. However, the combination of the metal sulfonate group-containing isophthalic acid component and the glycol component copolymerization amount mentioned in the examples is usually used. The dyeing property cannot be obtained, and the birefringence of the fiber is substantially high. As a result, the dyeing requires a high temperature and a high pressure of 120 ° C. Further, no reference is made to the range of the copolymerization amount of the metal sulfonate group-containing isophthalic acid component and the glycol component which can be dyed under atmospheric pressure. The method (3) has a problem in thermal stability of the polyester copolymerized with the amino group-containing compound. As described above, it has been impossible to obtain a polyester fiber which has a dyeing property under atmospheric pressure and is capable of being combined with a natural fiber or the like in a range where ordinary polymerization and yarn production are possible by the conventional polyester modification method.

[0005]

[Patent Document 1] Japanese Patent Publication No. 34-10497

[0006]

[Patent Document 2] JP-A-57-21014

[0007]

[Patent Document 3] Japanese Patent Laid-Open No. 48-52897

[0008]

The object of the present invention is to obtain extremely excellent dyeing properties not only for disperse dyes but also for cationic dyes, specifically, without losing the excellent mechanical properties of polyester fibers. It is an object of the present invention to provide a polyester fiber which can be dyed under normal pressure and which can be combined with a natural fiber such as silk or wool which is easily damaged at a high temperature.

[0009]

The object of the present invention is (1).
The copolymerization amount of the 5-sodium sulfoisophthalic acid component or the 5-lithium sulfoisophthalic acid component with respect to all the acid components in the polyester is S mol% (2.4 ≦ S ≦ 5), and the copolymerization amount of the glycol component is P% by weight. (2 ≦ P ≦ 7), S and P are copolymerized polyester fibers satisfying the formula (1), and the birefringence is 100 × 10 ⁻³ to 1
A polyester fiber characterized by having a size of 40 × 10 ⁻³ .

S × P ≧ 9.5 Formula (1) and (2) The copolymerization amount of 5-sodium sulfoisophthalic acid component or 5-lithium sulfoisophthalic acid component with respect to all acid components in the polyester is S mol% (2 .4 ≦
S ≦ 5), the copolymerization amount of the glycol component is P% by weight (2 ≦
When P ≦ 7), a highly oriented polyester undrawn yarn having a copolymerization amount of S and P satisfying the formula (1) and having an elongation of 130 to 180% is ((1 + elongation (%) / 100
(%)) × 0.6) to ((1 + elongation (%) / 100
(%)) × 0.8) at a draw ratio of a polyester fiber.

S × P ≧ 9.5 Formula (1) Can be achieved by

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.

The polyester in the present invention is one in which the main acid component is terephthalic acid or its ester derivative and the main glycol component is ethylene glycol.

In order to obtain the easily dyeable polyester fiber of the present invention, a 5-sodium sulfoisophthalic acid component or a 5-lithium sulfoisophthalic acid component (hereinafter abbreviated as S component) copolymerized with polyester is used. It is necessary to copolymerize 2.4 to 5 mol% with respect to all acid components constituting the polyester, and it is particularly preferable to copolymerize 2.4 to 4.0 mol%. When the copolymerization amount of the S component is 2.4 mol% or more, satisfactory cationic dyeability can be obtained by increasing the copolymerization amount of the glycol component. When the copolymerization amount of the S component is 5 mol% or less, the melt viscosity of the polymer due to the thickening action of the S component is suppressed and the yarn can be spun under normal spinning conditions. The S component in the present invention specifically means 5-sodium sulfoisophthalic acid, 5-sodium sulfoisophthalic acid dimethyl ester, 5-sodium sulfoisophthalic acid diethyl ester, 5-lithium sulfoisophthalic acid, 5-lithium sulfoisophthalic acid. Examples thereof include acid dimethyl ester and 5-lithium sulfoisophthalic acid diethyl ester.

Further, in the present invention, it is necessary that the glycol component is copolymerized in an amount of 2 to 7% by weight based on the whole polyester. From the viewpoint of easy dyeability and light fastness, the average molecular weight of the glycol component to be copolymerized is preferably 300 to 6000. Examples of the glycol component in the present invention include neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 4,4-dihydroxybisphenol, and the like. Examples of the glycol include polyethylene glycol to which ethylene oxide is added, and polyethylene glycol, and the like, and polyethylene glycol having a large viscosity reducing effect is more preferable. The copolymerization amount of the glycol component in the present invention needs to be 2 to 7% by weight based on the total polyester obtained. When the copolymerization amount of the glycol component is 2% by weight or more, the increase in melt viscosity of the polyester can be suppressed, the spinning operability is excellent, and the polyester fiber obtained is also easy to dye. When the copolymerization amount is 7% by weight or less, it is possible to suppress the decrease in polyester heat resistance. A more preferable copolymerization amount of the glycol component is 3 to 6% by weight.

Further, in the present invention, in order to achieve the atmospheric pressure cationic dyeability of the obtained polyester fiber, in addition to the range of the copolymerization amount of the S component and the glycol component, the S component is added. It is essential that the relationship of the formula (1) is established between S and P, where S is the molar amount of S and P is the molar amount of the glycol component is P% by weight.

S × P ≧ 9.0 Formula (1) When the value of S × P is 9.0 or more, cation dyeing can be performed under normal pressure and normal pressure. Atmospheric pressure cation dyeability cannot be obtained unless there is a relationship that satisfies the formula (1) even if only the S component or the glycol component is large.

The polyester fiber of the present invention has a birefringence of 1
It is necessary to be 00 × 10 ^{−3 to} 140 × 10 ⁻³ . When the birefringence is 100 × 10 ⁻³ or more, the fibers are sufficiently oriented, the strength of the raw yarn itself is high, and problems such as yarn breakage and fluff occur in higher-order processes such as weaving and knitting. There is no. On the other hand, when the birefringence is 140 × 10 ⁻³ or less, the orientation of the fibers does not become too high, and the effect of improving the dyeing property by suppressing the orientation, which is the aim of the present invention, is sufficiently exhibited. The excellent dyeability is obtained because the orientation of the fiber is suppressed, and the effective utilization rate of the S component for the cationic dye is increased during the cationic dyeing. It is because it is easy to penetrate into.

The polyester fiber of the present invention is a polyester
To a certain amount of S component and glycol component
In addition to, the fiber birefringence is 100 × 10^-3~ 140x
10 ^-3And obtained by the prior art
Compared to cationic dyes and disperse dyes
It is now possible to obtain remarkably excellent atmospheric dyeability.
It was

This is because, in addition to the effect of improving the dyeability by the copolyester in which the S component and the glycol component are used in an amount having a specific relationship, the highly oriented undrawn yarn in the specific elongation region is stretched at a low ratio to give a polyester. This is due to the effect that the fiber orientation is suppressed and the dyeing temperature is lowered. The dyeing temperature of the present polyester fiber can be appropriately changed depending on the polymer composition, but is preferably 95 to 110 ° C.

Further, the polyester fiber of the present invention is obtained by copolymerizing the S component and the glycol component in an amount having a specific relationship with the polyester, and controlling the fiber structure in a specific range described below to obtain a normal pressure. It is possible to satisfy both the dyeability and the high-order passability.

First, the highly oriented undrawn yarn has an elongation of 130 to
It is necessary to set it to be 180%. When the elongation of the highly oriented undrawn yarn is 130% or more, the fiber orientation does not proceed too much at the stage of the undrawn yarn, and thus the drawn yarn has a strength that can be practically used. On the other hand, when the elongation of the highly oriented undrawn yarn is 180% or less, the fiber structure of the undrawn yarn does not become too loose, sufficient undrawn yarn strength is obtained, and high-order passability becomes good.

Secondly, using the above highly oriented undrawn yarn, the draw ratio is ((1 + elongation (%) / 100 (%)) × 0.
6) to ((1 + elongation (%) / 100 (%)) × 0.8)
It is necessary that the stretching is within the range. When the stretching ratio is ((1 + elongation (%) / 100 (%)) × 0.6) or more, the stretching is sufficiently performed and the strength becomes high, so that the high-order passability and the product quality are good. Becomes On the other hand, when the draw ratio is ((1 + elongation (%) / 100 (%)) × 0.8) or less, the suppression of the fiber orientation aimed at by the present invention can be achieved and the atmospheric dyeability can be obtained.

Thus, by stretching the highly oriented undrawn yarn having the elongation in a specific range at a low ratio, it becomes possible to obtain a polyester fiber which can be dyed under atmospheric pressure with both a cationic dye and a disperse dye.

[0025]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited to these examples. The various measuring methods in the present invention are as follows. (1) Elongation Obtain a load-elongation curve according to JIS standard L1013,
The value obtained by dividing the elongation by the initial sample length was multiplied by 100 to obtain the elongation (%). (2) Dyeability evaluation (cationic dye) After forming a polyester fiber into a cylinder knit, the knitted fabric is made of malachite green (manufactured by Kanto Kagaku) 5% owf, acetic acid 0.5 g /
1, sodium acetate 0.2 g / l, bath ratio 1: 100, temperature 9
It was dyed under the condition of 8 ° C. and evaluated by the exhaustion rate of the dye. The dye exhaustion rate is measured by a spectrophotometer (Hitachi, 607).
Type) was used to measure the difference in absorbance due to dyeing of the dye solution, and the difference was obtained by the following equation. Dye exhaustion rate (%) = {(B−A) × 100} / BA A: Absorbance at maximum absorption wavelength of dye solution after dyeing B: Absorbance at maximum absorption wavelength of dye solution before dyeing Those having a rate of 60% or more were determined to be dyeable under normal pressure. (3) Dyeability evaluation (disperse dye) As in (2), polyester fiber was knitted into cylinders, and as a dye, Diaix Black BG-FS (Disperse dye manufactured by Mitsubishi Kasei Co., Ltd.) 7
% Owf aqueous dispersion, bath ratio 1:30, 98 ° C. 60
A colorimeter (CM-370 manufactured by Minolta Co., Ltd.)
The L value was measured three times according to 0D) and the average value was obtained. In addition, here, those having an L value of 16.5 or less are considered to be dyeable under atmospheric pressure. (4) Birefringence The birefringence of the polyester fiber was measured with a polarization microscope (XTP-11) manufactured by NIKON. (5) Spinning operability Spinning operability is judged from the number of yarn breakages during spinning, the pressure inside the pack, etc., and is rated as excellent: ○○, excellent: ○, normal: △, defective:
The evaluation was made in four grades, x. (6) High-order passability The high-order passability is judged from yarn breakage, fluff generation, and fabric quality in the higher-order process during weaving and knitting and dyeing, and is rated as excellent: ○○,
The evaluation was made in four grades: excellent: ◯, good: Δ, poor: ×. (7) Light fastness The dyed knitted fabric obtained by the dyeing property evaluation with a cationic dye is subjected to carbon arc light at 60 ° C. for 1 time using a fade meter.
Irradiated for 0 hours. The obtained dyed cloth after irradiation was visually judged on the basis of three levels: ◯: very little discoloration, ◯: slightly discolored, ×: considerably discolored. (8) Intrinsic viscosity Polyester is dissolved in O-chlorophenol at 25 ° C.
It was measured at.

Example 1 Dimethyl terephthalate (hereinafter abbreviated as DMT) 94k
g, ethylene glycol 60 kg, a mixture of lithium acetate (0.2% by weight of DMT) and antimony oxide (0.04% by weight of DMT) as a reaction catalyst, and 5-sodium sulfoisophthalic acid dimethyl ester (manufactured by Takemoto Yushi Co., Ltd.). 3.7 kg and 4.0 kg of polyethylene glycol having an average molecular weight of 1000 (manufactured by Sanyo Kasei Co., Ltd.) were added, and gradually heated from 150 ° C. to 250 ° C. under a nitrogen atmosphere to continuously generate generated methanol outside the system. The transesterification reaction was carried out while distilling, and the reaction was completed 3 hours after the start of the reaction. Next, 41 g of trimethyl phosphate and 500 g of 16 wt% titanium dioxide ethylene glycol slurry
Was added.

Then, the polymerization reaction system was gradually depressurized to 13.3 Pa over 1 hour and 30 minutes and heated to 280 ° C. 1
Polymerization was carried out at a polymerization temperature of 280 ° C. for a further 2 hours under a reduced pressure of 3.3 Pa to obtain a polyester chip having an intrinsic viscosity of 0.74 at 84 k.
g was obtained. The obtained copolyester is spun at a spinning temperature of 29.
Spinning at 0 ° C, spinning speed 3000 m / min, elongation 160%
A highly oriented undrawn yarn of was obtained. Therefore, ((1 + elongation (%)
/100(%))×0.7) times 1.82 times to obtain a 110 dtex / 48f drawn yarn. The obtained polyester drawn yarn has an intrinsic viscosity of 0.72 and a birefringence of 11
The spinning operability was good at 5 × 10 ⁻³ .

The drawn yarn is knitted by a FAX knitting machine, and the temperature is 98 ° C.
After smelting with hot water, each was dyed at 98 ° C. using a cation and a disperse dye. The dyeability of the obtained knitted fabric is
Dye exhaustion rate of 97.3% for cationic dyes, L for disperse dyes
The value was 15.0, showing extremely excellent atmospheric dyeability in any dyeing. Further, the light fastness was evaluated, but almost no fading was observed, and the high-order passing property was also good.

Example 2 The polymer of Example 1 was used to increase the spinning speed and the elongation of 130.
% Highly oriented undrawn yarn was obtained. When this yarn was drawn, knitted, and dyed in the same manner as in Example 1, the dyeability under atmospheric pressure was lower than that in Example 1, but a polyester fiber having excellent spinnability and high-order passability was obtained. I was able to.

Example 3 As in Example 2, this time the spinning speed was reduced and the elongation was 180%.
A highly oriented undrawn yarn of was obtained. When this yarn was drawn and evaluated in the same manner as in Examples 1 and 2, the dyeing property was extremely excellent, but the fiber strength was rather low and the high-order passing property was slightly lowered.

Examples 4 to 5 In Examples 4 to 5, the draw ratio of the highly oriented undrawn yarn obtained in Example 1 was changed, and the dyeability, the spinnability and the high-order passability were evaluated. As a result, in Example 4, the stretching was insufficient and the strength was slightly low, and the high-order passability was slightly lower than in Example 1. Further, in Example 5, since the draw ratio is high,
The high-order passability was extremely good, but the atmospheric dyeability was lower than in Examples 1 and 2 because the fiber orientation was advanced.

Comparative Examples 1 and 2 In Comparative Examples 1 and 2, the copolymerization amount of the S component (dimethyl 5-sodium sulfoisophthalate) in the polyester was changed as shown in Table 2, and the spinnability, high-order passability, and The dyeability under atmospheric pressure was evaluated.

As a result, in Comparative Example 1, since the copolymerization amount of the S component was small, the atmospheric dyeability by cation dyeing could not be obtained. Further, in Comparative Example 2, since the amount of S component was extremely large, the internal pressure of the pack during spinning was excessive and it was difficult to produce yarn.

Comparative Examples 3 to 4 In Comparative Examples 3 to 4, spinning, drawing and knitting were carried out under the same manufacturing conditions as in Example 1 except that the copolymerization amount of the glycol component in the polyester was changed as shown in Table 2. Performed and evaluated. In Comparative Example 3, the amount of polyethylene glycol copolymerized was small, and the atmospheric dyeability was not obtained. Comparative Example 4 was excellent in atmospheric dyeability, but due to an excessively large amount of polyethylene glycol copolymerization, considerable discoloration was observed in the light fastness evaluation, and the spinning operability was poor and long-term spinning was not possible. It was

Comparative Example 5 Spinning, drawing and knitting were carried out and evaluated under the same manufacturing conditions as in Example 1 except that the S component and glycol copolymer were changed as shown in Table 2. Although it was excellent in thread-making and high-order passing properties, it was inferior in cation dyeability.

Comparative Examples 6 to 7 In Comparative Examples 6 to 7, the spinning speed and the draw ratio were changed so that the birefringence was 85 × 10 ⁻³ (Comparative Example 6) and the birefringence was 1.
55 × 10 ⁻³ drawn yarn (Comparative Example 7) was obtained and evaluated in the same manner. As a result, in Comparative Example 6, the structure of the fiber was too loose and the strength of the raw yarn was not sufficiently increased, and yarn breakage and fuzz occurred frequently in the yarn making process and the high-order processing process. On the other hand, in Comparative Example 7, the orientation of the fibers was sufficiently advanced, and thus the yarn-forming property and the high-order passability were very excellent, but on the contrary, the orientation was too advanced to obtain the atmospheric dyeability.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

EFFECTS OF THE INVENTION By using the polyester fiber of the present invention, it is possible to carry out atmospheric dyeing, which has not been achieved by the prior art, on cationic dyes and disperse dyes, and at the same time improve the spinnability and the high-order passability. You can

Claims (2)

[Claims] 1. A copolymerization amount of a 5-sodium sulfoisophthalic acid component or a 5-lithium sulfoisophthalic acid component with respect to all acid components in a polyester is S mol% (2.4 ≦).
S ≦ 5), the copolymerization amount of the glycol component is P% by weight (2 ≦
When P ≦ 7), S and P are copolymerized polyester fibers satisfying the formula (1) and have a birefringence of 100.
A polyester fiber characterized by having a size of × 10 ^{-3 to} 140 × 10 ^-3 . S × P ≧ 9.5 Formula (1) 2. The copolymerization amount of the 5-sodium sulfoisophthalic acid component or the 5-lithium sulfoisophthalic acid component with respect to the total acid components in the polyester is S mol% (2.4 ≦
S ≦ 5), the copolymerization amount of the glycol component is P% by weight (2 ≦
When P ≦ 7), a highly oriented polyester undrawn yarn having a copolymerization amount of S and P satisfying the formula (1) and having an elongation of 130 to 180% is ((1 + elongation (%) / 100
(%)) × 0.6) to ((1 + elongation (%) / 100
(%)) × 0.8) at a draw ratio of a polyester fiber. S × P ≧ 9.5 Formula (1)