JP7248507B2 - Spin-dyed meta-type wholly aromatic polyamide fiber and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a solution-dyed meta-type wholly aromatic polyamide fiber and a method for producing the same, and more particularly to a solution-dyed meta-type wholly aromatic polyamide fiber colored with two or more organic pigments, The present invention relates to a solution-dyed meta-type wholly aromatic polyamide fiber having a content of chlorinated benzenes and/or derivatives thereof of 1 ppm or less, and a method for producing the same.

It is well known that wholly aromatic polyamides produced from aromatic diamines and aromatic dicarboxylic acid dihalides are excellent in heat resistance and flame retardancy. It is well known that a polymer solution in which a wholly aromatic polyamide is soluble in a solvent and dissolved in the solvent can be made into fibers by dry spinning, wet spinning, semi-dry and semi-wet spinning, and the like.

Among these wholly aromatic polyamides, meta-type wholly aromatic polyamide (sometimes called "meta-aramid") fibers, represented by polymetaphenylene isophthalamide, are particularly useful as heat-resistant and flame-retardant fibers. It is used in fields where these properties are exhibited, for example, industrial applications such as filters and electronic parts, and disaster prevention safety clothing applications such as protective clothing where heat resistance, flame resistance, and flame resistance are emphasized.

In particular, when meta-type wholly aromatic polyamide fibers are used for protective clothing, etc., visibility and distinguishability are required, and design is also an important factor for products, and a variety of hues are required. be. In order to meet these requirements, the method of coloring the meta-type wholly aromatic polyamide fiber is a post-dyeing method in which a dye is used to dye the fiber after fiberization, or a raw material coloring method in which a pigment is added to the spinning stock solution to make the fiber. A) method is known.

The pigments or dyes used for these colors may contain compounds that are not desired to remain, and the compounds that are not desired to remain can be sufficiently removed during the manufacturing process. Otherwise, the aramid fibers in the final product may contain compounds that are not desired to remain as residual impurities. Residual impurities contained in aramid fibers can be hazardous to human health wearing clothing containing aramid fibers. Therefore, it is desirable to substantially completely remove these residual impurities from the aramid fibers.

As a process for removing residual impurities from aramid fibers, Patent Document 1 discloses removing residual impurities by dyeing aramid fibers by a carrier dyeing method that does not add dye.

However, the method described in Patent Document 1 requires a large number of steps, and in the steps, acid or alkali is used in order to adjust the pH of the solution used, and the environmental It is necessary to use an extraction solution containing benzyl alcohol, which has a high load on the As a result, the manufacturing cost is high, the industrial utility value is low, and the load on the environment is high.

Japanese Patent Publication No. 2015-520808

An object of the present invention is to solve the problems in the prior art, and to provide a solution-dyed meta-type wholly aromatic polyamide fiber colored to a desired concentration with two or more kinds of organic pigments, which comprises chlorinated benzene in the fiber. An object of the present invention is to provide a solution-dyed meta-type wholly aromatic polyamide fiber containing 1 ppm or less of the genus and/or derivatives thereof.

As a result of intensive studies to solve the above problems, the present inventors have found that the type and content of chlorinated benzenes and/or derivatives thereof contained in organic pigments used for coloring raw materials. The inventors have found that the above problems can be solved by skillful control, and have completed the present invention.

That is, according to the present invention,
1. A raw material-colored solution-dyed meta-type wholly aromatic polyamide fiber containing 0.1 to 2.5% by mass of a colorant composed of two or more organic pigments based on the mass of the fiber, A solution-dyed meta-type wholly aromatic polyamide fiber, characterized in that the content of chlorinated benzenes and/or derivatives thereof in the fiber is 1 ppm or less, and
2. A coloring agent composed of two or more kinds of organic pigments, wherein the total content of chlorinated benzenes and/or derivatives thereof contained in the coloring agent is 500 ppm or less. A method for producing a pre-dyed meta-type wholly aromatic polyamide fiber, characterized by adding it to a dope for spinning a wholly aromatic polyamide and then spinning it,
is provided.

According to the present invention, a solution-dyed meta-type wholly aromatic polyamide fiber colored to a desired concentration, wherein the content of chlorinated benzenes and/or derivatives thereof in the fiber is 1 ppm or less. Since a type wholly aromatic polyamide fiber can be obtained, residual impurities such as chlorinated benzenes and/or derivatives thereof, for which regulations have been tightened in recent years, can be reduced as much as possible.

The present invention will be described in detail below.
The meta-type wholly aromatic polyamide in the present invention is a polyamide produced by, for example, solution polymerization or interfacial polymerization using a meta-type aromatic diamine and a meta-type aromatic dicarboxylic acid halide as raw materials. may be obtained by copolymerizing other copolymerization components, such as para-type, within a range that does not impede.

Examples of meta-type aromatic diamines include metaphenylenediamine, 3,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl sulfone, and the like, and substitution of these aromatic rings with halogen, alkyl groups having 1 to 3 carbon atoms, or the like. Derivatives having groups such as 2,4-toluylenediamine, 2,6-toluylenediamine, 2,4-diaminochlorobenzene, 2,6-diaminochlorobenzene and the like can be used. Among them, meta-phenylenediamine or the mixed diamine containing 70 mol % or more of meta-phenylenediamine is preferable.

In addition, the above meta-type aromatic dicarboxylic acid halides include isophthalic acid halides such as isophthalic acid chloride and isophthalic acid bromide, and derivatives having substituents such as halogens and alkoxy groups having 1 to 3 carbon atoms on the aromatic rings thereof, For example, 3-chloroisophthalic acid chloride and 3-methoxyisophthalic acid chloride can be used. Among them, isophthalic acid chloride or the mixed carboxylic acid halide containing 70 mol % or more of isophthalic acid chloride is preferable.

Copolymerization components that can be used in addition to the above diamines and dicarboxylic acid halides include aromatic diamines such as paraphenylenediamine, 2,5-diaminochlorobenzene, 2,5-diaminobromobenzene, and benzene derivatives such as aminoanisidine. , 1,5-naphthylenediamine, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ketone, 4,4′-diaminodiphenylamine, 4,4′-diaminodiphenylmethane, etc., while aromatic Dicarboxylic acid halides include terephthalic acid chloride, 1,4-naphthalenedicarboxylic acid chloride, 2,6-naphthalenedicarboxylic acid chloride, 4,4'-biphenyldicarboxylic acid chloride, 4,4'-diphenyletherdicarboxylic acid chloride, and the like. .

If the copolymerization ratio of these copolymerization components is too high, the properties of the meta-type wholly aromatic polyamide tend to deteriorate, so the copolymerization ratio is preferably 20 mol % or less based on the total acid components of the polyamide. Particularly preferred meta-type wholly aromatic polyamides are polyamides in which 80 mol % or more of all repeating units are metaphenylene isophthalamide units, and polymetaphenylene isophthalamide is particularly preferred.

The degree of polymerization of such a meta-type wholly aromatic polyamide is suitably in the range of 1.3 to 3.0 for the intrinsic viscosity (IV) measured at 30° C. using 97% concentrated sulfuric acid as a solvent.

Next, a spinning dope is prepared by dissolving the meta-type wholly aromatic polyamide obtained here in a solvent that dissolves it, but it is also possible to use the spinning dope as it is without isolating the meta-type wholly aromatic polyamide after polymerization. . As the solvent used here, an amide solvent can generally be used, and examples of main amide solvents include N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), and the like. can do. Among these, it is preferable to use NMP or DMAc from the viewpoint of solubility and handling safety.

As the concentration of the solution, an appropriate concentration may be appropriately selected from the viewpoint of the solidification rate in the next spinning and solidifying process and the solubility of the polymer. For example, the polymer is polymetaphenylene isophthalamide and the solvent is NMP. In the case of , it is usually preferable to make the range from 10 to 30% by mass.

In the present invention, the spinning dope contains a colorant composed of two or more kinds of organic pigments, and the total content of chlorinated benzenes and/or derivatives thereof contained in the colorant is 500 ppm or less. A coloring agent is added in an amount of 0.1 to 2.5% by mass based on the mass of the polymer component. Here, the chlorinated benzenes are those in which chlorine is added to the benzene ring, and o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, 1,2,3-trichlorobenzene, 1,2, 4-trichlorobenzene, 1,3,5-trichlorobenzene, 1,2,3,4-tetrachlorobenzene, 1,2,3,5-tetrachlorobenzene, 1,2,4,5-tetrachlorobenzene, pentachlorobenzene, etc. is mentioned.

The total content of chlorinated benzenes and/or derivatives thereof in the colorant is preferably 300 ppm or less, more preferably 200 ppm or less, because the lower the better.

Organic pigments used here include azo-based, phthalocyanine-based, perinone-based, perylene-based, and anthraquinone-based organic pigments, but are not limited to these. In addition, the organic pigment in these colorants is added in an amount of 0.1 to 2.5% by mass relative to the mass of the polymer component. Significantly degraded and inappropriate. On the other hand, if it is 0.1% by mass or less, it becomes difficult to sufficiently color the fibers.

A combination of two or more organic pigments as the colorant is necessary to adjust the hue to a target, and it is also possible to combine inorganic pigments to adjust the color.

The above organic pigment is preferably heat-treated at 160°C or higher for 15 minutes or longer, more preferably 180°C or higher, before being added to the meta-type wholly aromatic polyamide spinning dope. Heat treatment at 200° C. or higher is more preferable. By this heat treatment, it is possible to reduce residual solvent and impurities during the production of the organic pigment. On the other hand, in the case of treatment at 160° C. or lower, there is a tendency for a large amount of solvent and impurities to remain, and the total content of chlorinated benzenes and/or derivatives thereof may exceed 300 ppm.

Next, the spinning dope prepared as described above is spun into a coagulation bath and coagulated. A spinning device is not particularly limited, and a conventionally known wet spinning device can be used. Further, the number of spinning holes, the arrangement state, the shape of the holes, etc. of the spinneret are not particularly limited as long as they can be stably spun. A multi-hole spinneret for 2 mm staple may be used.

The temperature of the spinning dope during spinning from the spinneret is suitably in the range of 10 to 90°C.
As an example of the coagulation bath, an aqueous solution of an amide-based solvent containing no inorganic salt and having a concentration of 45 to 60% by weight is used at a bath liquid temperature of 10 to 35.degree. Here, if the concentration of the amide-based solvent is less than 45% by mass, the fiber skin will have a thick structure, the washing efficiency in the washing process will decrease, the solvent will remain in the obtained fiber, and the chlorinated A large amount of benzenes and/or derivatives thereof will also remain. On the other hand, if the concentration of the amide-based solvent exceeds 60% by mass, uniform coagulation cannot be performed to the inside of the fiber, and many problems such as breakage of single yarns occur during fiber molding. Incidentally, the immersion time of the fiber in the coagulation bath is suitably in the range of 0.1 to 30 seconds.

Next, while the fibers coagulated in the coagulation bath are in a plastic state, the fibers are drawn in a plastic drawing bath. The plastic stretching bath is not particularly limited, and conventionally known bath solutions can be employed. In order to obtain the fiber of the present invention, the draw ratio in the plastic drawing bath is preferably in the range of 3.5 to 5.0 times, more preferably in the range of 3.7 to 4.5 times. .

In the production of the fiber of the present invention, the removal of the solvent from the coagulated filament can be accelerated by carrying out plastic drawing at a specific magnification in a plastic drawing bath. It is thought that the chlorinated benzenes and/or derivatives thereof in the colorant are also removed from the fiber at the same time as the solvent is removed. If the draw ratio in the plastic drawing bath is less than 3.5 times, the removal of the solvent from the coagulation bath becomes insufficient, resulting in a decrease in breaking strength and difficulty in handling in processing steps such as spinning. Also, the content of chlorinated benzenes and/or derivatives thereof in the fiber may be 1 ppm or more. On the other hand, if the draw ratio in the plastic drawing bath exceeds 5.0 times, single filament breakage occurs, resulting in poor process stability.

The temperature of the plastic stretching bath is preferably in the range of 10 to 90°C. More preferably, it is 20 to 90°C.
Following plastic drawing, the fibers are washed of residual solvent. In this step, the drawn fibers are thoroughly washed in a plastic drawing bath. Washing is preferably carried out in multiple stages because it affects the quality of the resulting fiber. In particular, the temperature of the washing bath and the concentration of the amide solvent in the washing bath liquid in the washing process affect the state of extraction of the amide solvent from the fibers and the state of penetration of water from the washing bath into the fibers. Therefore, in order to optimize these conditions, it is preferable to perform the washing process in multiple stages and control the temperature and concentration conditions within appropriate ranges.

If the temperature of the first washing bath is set to 60° C. or higher, water will permeate into the fibers at once, resulting in the formation of huge voids in the fibers and deterioration of the quality. For this reason, it is preferable that the initial cleaning bath be at a low temperature of 30° C. or less.

If the solvent remains in the fiber, the fiber will turn yellow and the environmental safety is not preferable when processing or using the product using the fiber. The content is preferably 2% by mass or less, more preferably 0.15% by mass or less, and even more preferably 0.1% by mass or less.

After the washing step, the fibers are then dried and heat-treated. Methods of drying and heat treatment are not particularly limited, and examples thereof include methods using a hot roller, a hot plate, and the like.

In order to obtain the fiber of the present invention, the heat treatment temperature is preferably in the range of 260-350°C, more preferably in the range of 270-340°C. If the heat treatment temperature is lower than 260° C., the crystallization of the fibers may be insufficient and the shrinkage of the fibers may increase. On the other hand, when the heat treatment temperature exceeds 350° C., the crystallization of the fiber proceeds too much, and the elongation at break of the fiber may be remarkably lowered. When the heat treatment temperature is in the range of 270 to 340°C, it can contribute to the improvement of the breaking strength of the fiber.

The heat-treated fibers may be further crimped if necessary. Further, after crimping, the fibers may be cut into appropriate fiber lengths and used as staple fibers, or may be wound as multifilaments.

The present invention will be described in more detail below with reference to examples. However, the present invention is not limited by these examples.
All "parts" and "%" in the examples are on a mass basis unless otherwise specified, and quantitative ratios indicate mass ratios unless otherwise specified. Each physical property value in Examples and Comparative Examples was measured by the following methods.

<Intrinsic viscosity (I.V.)>
The polymer was dissolved in 97% concentrated sulfuric acid and measured at 30°C using an Ostwald viscometer.

<Fineness>
Based on JIS L1015, measurement was carried out in conformity with the A method of regular fineness, and the apparent fineness was expressed.

<Breaking strength, breaking elongation>
Based on JIS L1015, using Instron Model No. 5565, values measured under the following conditions were taken as the breaking strength and breaking elongation of the fiber.
(Measurement condition)
Grip interval: 20mm
Initial load: 0.044cN (1/20g)/dtex
Tensile speed: 20mm/min

<Color difference ΔE from target hue>
Using a spectral colorimeter SD7000 (manufactured by Nippon Denshoku Kogyo Co., Ltd.), the lightness L1 value and the chromaticity a1 and b1 values of raw cotton colored to the target hue are first determined.
Next, the lightness L2 value, chromaticity a2 value and b2 value of the raw cotton obtained by the example or comparative example that is to be colored to the same hue as the target hue are obtained, and the target hue and the target hue are obtained by the following equation. Obtain the color difference ΔE.
ΔE = ((L1-L2) ² + (a1-a2) ² + (b1-b2) ² ) ^1/2
In other words, in Comparative Example 1 and Example 2, which are intended to be colored in the same hue as in Example 1, it can be said that the smaller the value of ΔE, the closer the hue is to that in Example 1.
Similarly, Comparative Example 2 and Example 3, Comparative Example 3 and Example 4, and Comparative Example 4 and Example 5, respectively, are examples of trying to color with the same hue. was indicated by ΔE.

<Content of chlorinated benzenes>
The above chlorinated benzenes and/or dichlorobenzene, which is one of its derivatives, was measured according to Oeko-Tex Standard 100 by an Oeko-Tex certification body.

[Example 1]
(Manufacture of polymer)
721.5 parts by mass of N,N-dimethylacetamide (DMAc) having a moisture content of 100 ppm or less was weighed into a reaction vessel under a dry nitrogen atmosphere, and 97.2 parts by mass (50.18 mol) of metaphenylenediamine was added to this DMAc. %) was dissolved and cooled to 0°C. To this cooled DMAc solution, 181.3 parts by mass (49.82 mol %) of isophthaloyl chloride (hereinafter abbreviated as IPC) was gradually added with stirring to carry out a polymerization reaction.

Next, 66.6 parts by mass of calcium hydroxide powder having an average particle size of 10 μm or less was weighed and slowly added to the polymer solution in which the polymerization reaction had been completed to carry out a neutralization reaction. After the addition of calcium hydroxide was completed, the mixture was further stirred for 40 minutes to obtain a clear polymer solution.

Polymetaphenylene isophthalamide was isolated from the resulting polymer solution and IV was measured to be 1.65. Also, the polymer concentration in the polymer solution was 17%.

(manufacture of dope)
To the obtained polymer solution, a powder obtained by mixing 25% by mass of Pigment Yellow 12 and 75% by mass of Pigment Red 64 as colorants was added so as to be 2.14% by mass with respect to the mass of the polymer component, and then the polymer was added. The solution was sufficiently stirred to uniformly disperse the pigment. This was defoamed under reduced pressure to obtain a spinning dope.

The content of dichlorobenzene in the pigments used as the coloring agents was 700 ppm for Pigment Yellow 12, 140 ppm for Pigment Red 64, and 280 ppm in the coloring agent.

(spinning)
The spinning dope was discharged into a coagulation bath having a bath temperature of 30° C. and spun from a spinneret having a hole diameter of 0.07 mm and a hole number of 500. The composition of the coagulation liquid was water/DMAc=45/55 (parts by mass), and the spinning was performed by discharging into the coagulation bath at a yarn speed of 7 m/min.

Subsequently, the film was stretched at a draw ratio of 3.7 times in a plastic drawing bath having a composition of water/DMAc=45/55 at a temperature of 40°C.

After stretching, it was washed in a water/DMAc = 70/30 bath at 20°C (immersion length 1.8 m), followed by washing in a water bath at 20°C (immersion length 3.6 m), and further in a hot water bath at 60°C (immersion length 5 .4 m) for thorough washing.

The washed fibers were subjected to a dry heat treatment with a hot roller having a surface temperature of 280° C., and the meta-type wholly aromatic polyamide fibers were sampled in the tow state and measured for breaking strength and breaking elongation.

Further, the towed fibers obtained were bundled, passed through a crimper, crimped, and then cut with a cutter into short fibers of 51 mm to obtain raw cotton.

The raw cotton thus obtained was thoroughly opened, the fibers were oriented in the same direction, placed in a cell for measurement, and the lightness and chromaticity were measured using a spectral colorimeter SD7000 (manufactured by Nippon Denshoku Industries Co., Ltd.). In addition, the content of dichlorobenzene in the fibers of this raw cotton was suppressed to 0.73 ppm and 1 ppm or less. The physical properties of raw cotton were fineness of 1.73 dtex, strength of 3.24 cN/dtex, and elongation of 23.5%. These results are shown in Table 1.

[Comparative Example 1]
After adding a powder obtained by mixing 27% by mass of Pigment Yellow 12 and 73% by mass of Pigment Red 254 as colorants to the polymer solution produced in Example 1 so as to be 2.20% by mass with respect to the mass of the polymer component. , the polymer solution was sufficiently stirred to uniformly disperse the pigment. It was carried out in the same manner as in Example 1, except that this was degassed under reduced pressure to obtain a spinning dope.

The content of dichlorobenzene in the pigments used as the coloring agents was 700 ppm for Pigment Yellow 12 and 2300 ppm for Pigment Red 254, and 1868 ppm in the coloring agent.

The color difference ΔE between the obtained raw cotton and the raw cotton of Example 1 was 0.49, which was a hue close to that of Example 1, but the dichlorobenzene content in the fiber in this raw cotton was 4.21 ppm, which was lower than 1 ppm. much larger value.

The physical properties of raw cotton were fineness of 1.68 dtex, strength of 3.02 cN/dtex, and elongation of 24.6%. These results are shown in Table 1.

[Example 2]
The polymer solution produced in Example 1 was mixed with 27% by mass of Pigment Yellow 12 as a coloring agent and 73% by mass of Pigment Red 254 used in Comparative Example 1 after heat treatment at 160° C. for 30 minutes. After adding 2.20% by mass of the obtained powder to the mass of the polymer component, the polymer solution was sufficiently stirred to uniformly disperse the pigment. It was carried out in the same manner as in Example 1, except that this was degassed under reduced pressure to obtain a spinning dope.

The content of dichlorobenzene in the pigments used as the coloring agents was 700 ppm for Pigment Yellow 12, 400 ppm for Pigment Red 254 after heat treatment, and 481 ppm in the coloring agent.

The color difference ΔE between the obtained raw cotton and the raw cotton of Example 1 is 0.70, which is a hue close to that of Example 1, and the dichlorobenzene content in the fiber in this raw cotton is 0.85 ppm, which can be suppressed to 1 ppm or less. did it. The physical properties of the raw cotton were fineness of 1.71 dtex, strength of 3.35 cN/dtex, and elongation of 24.7%. These results are shown in Table 1.

[Example 3]
The polymer solution produced in Example 1 was mixed with 34% by mass of Pigment Yellow 12, 19% by mass of Pigment Red 64, and 47% by mass of Pigment Blue 15 as colorants. %, the polymer solution was sufficiently stirred to uniformly disperse the pigment. It was carried out in the same manner as in Example 1, except that this was degassed under reduced pressure to obtain a spinning dope.

The content of dichlorobenzene in the pigments used as the coloring agents was 700 ppm for Pigment Yellow 12, 140 ppm for Pigment Red 64, and 240 ppm for Pigment Blue 15, and 377 ppm was contained in the coloring agent.

The brightness and chromaticity of the obtained raw cotton were measured using a spectral colorimeter SD7000 (manufactured by Nippon Denshoku Industries). In addition, the content of dichlorobenzene in the fibers of this raw cotton was suppressed to 0.24 ppm and 1 ppm or less. The physical properties of the raw cotton were fineness of 1.77 dtex, strength of 3.45 cN/dtex, and elongation of 32.2%. These results are shown in Table 1.

[Comparative Example 2]
The polymer solution produced in Example 1 was mixed with 36% by mass of Pigment Yellow 12, 23% by mass of Pigment Red 254, and 41% by mass of Pigment Blue 15 as colorants. %, the polymer solution was sufficiently stirred to uniformly disperse the pigment. It was carried out in the same manner as in Example 1, except that this was degassed under reduced pressure to obtain a spinning dope.

The content of dichlorobenzene in the pigments used as the coloring agents was 700 ppm for Pigment Yellow 12, 2300 ppm for Pigment Red 254, and 240 ppm for Pigment Blue 15, and was contained in the coloring agent at 879 ppm.

The color difference ΔE between the obtained raw cotton and the raw cotton of Example 3 was 0.79, which was a hue close to that of Example 3, but the dichlorobenzene content in the fiber of this raw cotton was 1.23 ppm, which was larger than 1 ppm. became a value. The physical properties of the raw cotton were fineness of 1.74 dtex, strength of 3.52 cN/dtex, and elongation of 33.8%. These results are shown in Table 1.

[Example 4]
The polymer solution produced in Example 1 was mixed with 4% by mass of Pigment Yellow 12, 11% by mass of Pigment Red 254, and 85% by mass of Pigment Blue 15 as colorants. %, the polymer solution was sufficiently stirred to uniformly disperse the pigment. It was carried out in the same manner as in Example 1, except that this was degassed under reduced pressure to obtain a spinning dope.

The content of dichlorobenzene in the pigments used as the colorants was 700 ppm for Pigment Yellow 12, 2300 ppm for Pigment Red 254, and 240 ppm for Pigment Blue 15, and the content of dichlorobenzene in the colorant was 485 ppm.

The brightness and chromaticity of the obtained raw cotton were measured using a spectral colorimeter SD7000 (manufactured by Nippon Denshoku Industries). In addition, the content of dichlorobenzene in the fibers of this raw cotton was suppressed to 0.52 ppm and 1 ppm or less. The physical properties of raw cotton were fineness of 1.74 dtex, strength of 3.56 cN/dtex, and elongation of 34.3%. These results are shown in Table 1.

[Comparative Example 3]
5% by mass of Pigment Yellow 12, 18% by mass of Pigment Red 64, and 77% by mass of Pigment Blue 15 as colorants in the polymer solution produced in Example 1, and 0.58% by mass of the powder was mixed with respect to the mass of the polymer component. %, the polymer solution was sufficiently stirred to uniformly disperse the pigment. It was carried out in the same manner as in Example 1, except that this was degassed under reduced pressure to obtain a spinning dope.

The content of dichlorobenzene in the pigments used as the coloring agents was 700 ppm for Pigment Yellow 12, 140 ppm for Pigment Red 64, and 240 ppm for Pigment Blue 15, and 245 ppm was contained in the coloring agent.

The color difference ΔE between the obtained raw cotton and the raw cotton of Example 4 was 0.50, which was a hue close to that of Example 4, but the dichlorobenzene content in the fiber in this raw cotton was 2.01 ppm, which was lower than 1 ppm. much larger value.

The physical properties of raw cotton were fineness of 1.70 dtex, strength of 3.34 cN/dtex, and elongation of 30.6%. These results are shown in Table 1.

[Example 5]
A powder obtained by mixing 13% by mass of Pigment Yellow 12, 35% by mass of Pigment Red 64, 9% by mass of Pigment Red 254, and 43% by mass of Pigment Blue 15 as colorants in the polymer solution produced in Example 1 was added as a polymer component. After adding 0.30% by mass based on the mass, the polymer solution was sufficiently stirred to uniformly disperse the pigment. It was carried out in the same manner as in Example 1, except that this was degassed under reduced pressure to obtain a spinning dope.

The content of dichlorobenzene in the pigment used as the colorant here is 700 ppm for Pigment Yellow 12, 140 ppm for Pigment Red 64, 2300 ppm for Pigment Red 254, and 240 ppm for Pigment Blue 15, and 450 ppm is contained in the colorant. Met.

The brightness and chromaticity of the obtained raw cotton were measured using a spectral colorimeter SD7000 (manufactured by Nippon Denshoku Industries). In addition, the content of dichlorobenzene in the fibers of this raw cotton was suppressed to 0.18 ppm and 1 ppm or less. The physical properties of raw cotton were fineness of 1.76 dtex, strength of 3.70 cN/dtex, and elongation of 35.0%. These results are shown in Table 1.

[Comparative Example 4]
The polymer solution produced in Example 1 was mixed with 14% by mass of Pigment Yellow 12, 39% by mass of Pigment Red 254, and 47% by mass of Pigment Blue 15 as colorants. %, the polymer solution was sufficiently stirred to uniformly disperse the pigment. It was carried out in the same manner as in Example 1, except that this was degassed under reduced pressure to obtain a spinning dope.

The content of dichlorobenzene in the pigments used as the colorants was 700 ppm for Pigment Yellow 12, 2300 ppm for Pigment Red 254, and 240 ppm for Pigment Blue 15, and 1108 ppm in the colorant.

The color difference ΔE between the obtained raw cotton and the raw cotton of Example 4 was 0.80, which was a hue close to that of Example 4, but the dichlorobenzene content in the fiber in this raw cotton was 1.67 ppm, which was lower than 1 ppm. much larger value.

The physical properties of raw cotton were fineness of 1.73 dtex, strength of 3.68 cN/dtex, and elongation of 31.7%. These results are shown in Table 1.

[Comparative Example 5]
After adding a powder obtained by mixing 25% by mass of Pigment Yellow 12 and 75% by mass of Pigment Red 64 as colorants to the polymer solution produced in Example 1 so as to be 2.75% by mass with respect to the mass of the polymer component. , the polymer solution was sufficiently stirred to uniformly disperse the pigment. It was carried out in the same manner as in Example 1, except that this was degassed under reduced pressure to obtain a spinning dope.

The raw cotton obtained had a very low fineness of 1.76 dtex, a strength of 2.36 cN/dtex and an elongation of 21.7% due to the large amount of coloring agent added to the fiber. These results are shown in Table 1.

According to the present invention, a solution-dyed meta-type wholly aromatic polyamide fiber colored to a desired concentration, wherein the content of chlorinated benzenes and/or derivatives thereof in the fiber is 1 ppm or less. Since a type wholly aromatic polyamide fiber can be obtained, it is possible to obtain a fiber material particularly suitable for use in protective clothing, etc., and in particular, it is possible to provide a clothing material whose safety has been certified by a certification body such as Oeko-Tex. can.

Claims (3)

A raw material-colored solution-dyed meta-type wholly aromatic polyamide fiber containing a colorant composed of two or more organic pigments in an amount of 0.1 to 2.5% by mass based on the mass of the fiber, wherein the fiber contains 1 ppm or less of chlorinated benzenes and/or derivatives thereof. A colorant composed of two or more kinds of organic pigments, wherein the total content of chlorinated benzenes and/or derivatives thereof contained in the colorant is 500 ppm or less, is a meta-type wholly aromatic colorant. A method for producing a pre-dyed meta-type wholly aromatic polyamide fiber, characterized by adding the compound to a dope for spinning a group polyamide, and then spinning the fiber. 3. The method for producing a pre-dyed meta-type wholly aromatic polyamide fiber according to claim 2, wherein the organic pigment is heat-treated at 160[deg.] C. or higher for 15 minutes or more before adding the organic pigment to the dope for spinning the meta-type wholly aromatic polyamide.