JP2021091993A - Spun-dyed meta-type wholly aromatic polyamide fiber excellent in visibility, and method for producing the same - Google Patents

Abstract

To provide a meta-type wholly aromatic polyamide fiber capable of realizing high visibility and reduction in weight in protective clothing and work clothing which are excellent in flame retardant performance and worn by firemen and workers performing fire operation.SOLUTION: A yellow color fluorescent pigment of 0.5 to 10.0 mass% is added to a spinning dope obtained by dissolving a meta-type wholly aromatic polyamide in a solvent, and then the spinning dope is subjected to spinning and drawing through a spinneret to remove the solvent by washing with water, followed by repeating heat treatment at 280 to 310°C at least twice per once for 5 seconds or shorter to set a chromaticity coordinate (x, y) of the fiber at CIE 15.2 in a range of a color space surrounded by (0.387, 0.610), (0.356, 0.494), (0.398, 0.452) and (0.460, 0.540).SELECTED DRAWING: None

Description

The present invention relates to an original meta-type total aromatic polyamide fiber preferably used for a fabric for protective clothing having excellent flame retardancy and high visibility, and a method for producing the same. More specifically, a yellow fluorescent pigment is used. The chromaticity coordinates (x, y) of the colored and obtained fibers according to CIE 15.2 are (0.387, 0.610), (0.356, 0.494), (0.398, 0. 452) and (0.460, 0.540) are within the range of the color space, and the chromaticity β is 0.70 or more.

Firefighters and workers who perform fire work wear protective clothing and work clothes with excellent flame-retardant performance, but there are also many activities outdoors at night, especially in activities on the road, etc. The risk of being involved in a contact accident with a person is very high. Therefore, in order to make the driver of the vehicle aware of its existence and prevent a contact accident, it is effective to improve the visibility of the protective clothing and work clothes worn.

On the other hand, among the total aromatic polyamides, the fibers of the meta-type total aromatic polyamide represented by polymetaphenylene isophthalamide (sometimes referred to as "meta-aramid") are particularly useful as heat-resistant and flame-retardant fibers. It has been known that it is a thing, and it is often used in manufacturing the above-mentioned protective clothing and work clothes having excellent flame retardant performance.

However, since it is difficult to dye meta-type all-aromatic polyamide fibers in a color with high visibility, so far, protective clothing and work clothes with low visibility and highly visible sashes have been worn. It has been obliged to wear it together or attach parts made of high-visibility material with low flame retardancy.

As one solution to such a problem, filaments that have been highly visible in advance are placed on the front surface, and threads such as heat-stable meta-aromatic polyamide fibers and self-extinguishing modacrylic fibers are used on the back surface. A double woven fabric in which threads are arranged in combination has been proposed (Patent Document 1).

Further, as another solution, a single-layer double-sided fabric containing a flame-retardant dyeable yarn made of flame-retardant polyester fiber or the like and a non-fused fiber yarn made of meta-type all-aromatic polyamide fiber. It has also been proposed to prepare a fabric in which the flame-retardant dyeable yarn of the above mainly constitutes the front side of the fabric and the non-fused fiber yarn mainly constitutes the back side of the fabric, and the front side of the fabric is dyed in a highly visible color. (Patent Document 2).

As yet another method, one surface (A surface) is a fiber that can be dyed mainly within the color coordinates specified in ISO 20471 and at the brightness rate, and is made of polyester fiber, nylon fiber, acrylic fiber. It is composed of threads composed of one or a plurality of these fibers, while the other surface (side B) is composed of threads in which flame-retardant fibers having self-extinguishing properties and non-melted fibers are blended. It has been proposed to dye and use the cloth (Patent Document 3).

Further, since it is said that the meta-type total aromatic polyamide fiber has poor light fastness, a white pigment is attached to at least one surface of the fabric made of the fiber via a binder resin, and the white pigment is fluorescent on the white pigment. A colored fiber fabric having a high visibility and in which a resin layer containing a colored pigment using a pigment is formed has been proposed (Patent Document 4).

However, the methods described in Patent Documents 1 to 3 all use a cloth having a structure of two or more layers, and protective clothing and work clothes using these have the disadvantage of increasing the weight due to the structure. In addition to this, there was a problem that a part with low flame retardancy was present on the work clothes and the protective function from flames and the like was deteriorated.

Further, in Patent Document 4, since the resin layer is provided on the cloth, the air permeability is low, and there is a problem that it gets stuffy when wearing protective clothing or work clothes. Further, when the resin layer is cracked or the like, the color difference from the fiber layer is conspicuous.

Japanese Patent No. 3994054 Japanese Patent No. 5922093 International Publication No. 2016/152814 International Publication No. 2017/047461

An object of the present invention is to solve the problems in the prior art and realize high visibility and weight reduction in protective clothing and work clothes having excellent flame retardant performance worn by firefighters and workers performing fire work. It is an object of the present invention to provide a possible meta-type total aromatic polyamide fiber.

As a result of diligent studies to solve the above problems, the present inventor added a specific yellow fluorescent pigment to a spinning dope obtained by dissolving a meta-type total aromatic polyamide in a solvent, and then spinning and drawing. However, it has been found that the original meta-type total aromatic polyamide fiber having high visibility can be obtained by subjecting it to dry heat treatment under specific conditions, and the present invention has been completed.

That is, according to the present invention.
1. 1. A meta-type total aromatic polyamide fiber containing 0.5 to 10.0% by mass of a yellow-based fluorescent pigment, wherein the yellow-based fluorescent pigment is an organic solvent used for producing the meta-type total aromatic polyamide. It is insoluble in a 70 mass% aqueous solution, and the chromaticity coordinates (x, y) of the meta-type total aromatic polyamide fiber according to CIE 15.2 are (0.387, 0.610), (0.356, 0. 494), (0.398, 0.452) and (0.460, 0.540) are within the range of the color space, and the brightness rate β is 0.70 or more. Original meta-type total aromatic polyamide fiber and
2. A yellow fluorescent pigment was added in an amount of 0.5 to 10.0% by mass to a spinning dope obtained by dissolving a meta-type total aromatic polyamide in a solvent, spun-stretched through a spinneret, and the solvent was removed by washing with water. , 280-310 ° C. dry heat treatment was repeated at least twice for 5 seconds or less at a time, and the chromaticity coordinates (x, y) according to CIE 15.2 of the fiber were set to (0.387, 0.610). All of the original metatypes, characterized in that they are within the color space enclosed by (0.356, 0.494), (0.398, 0.452) and (0.460, 0.540). Method for producing aromatic polyamide fiber,
Is provided.

According to the present invention, by producing a fabric using the obtained original meta-type total aromatic polyamide fiber, protective clothing and work having high visibility with excellent flame retardancy while having a good wearing feeling. Clothes can be obtained, and it becomes possible for people involved in firefighting activities and lifesaving work and people involved in repair work such as roads to easily work and ensure safety in poor visibility at night or due to bad weather.

Hereinafter, the present invention will be described in detail.

The meta-type total aromatic polyamide in the present invention is a polyamide produced by, for example, solution polymerization or interfacial polymerization using meta-type aromatic diamine and meta-type aromatic dicarboxylic acid halide as raw materials. It may be a copolymer of other copolymerization components such as para-type, as long as it does not inhibit the above.

Examples of the meta-aromatic diamine include metaphenylenediamine, 3,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl sulfone and the like, and a halogen on these aromatic rings and a substituent such as an alkyl group having 1 to 3 carbon atoms. For example, 2,4-toluylene diamine, 2,6-toluylene diamine, 2,4-diaminochlorobenzene, 2,6-diaminochlorobenzene and the like can be used. Among them, the above-mentioned mixed diamine containing 70 mol% or more of meta-phenylenediamine or meta-phenylenediamine is preferable.

Examples of the meta-aromatic dicarboxylic acid halide include isophthalic acid halides such as isophthalic acid chloride and isophthalic acid bromide, and derivatives having a substituent such as a halogen or an alkoxy group having 1 to 3 carbon atoms in these aromatic rings. For example, 3-chloroisophthalic acid chloride and 3-methoxyisophthalic acid chloride can be used. Among them, the above-mentioned mixed carboxylic acid halide containing 70 mol% or more of isophthalic acid chloride or isophthalic acid chloride is preferable.

Examples of the copolymerization component that can be used other than the above diamine and dicarboxylic acid halide include benzene derivatives such as paraphenylenediamine, 2,5-diaminochlorobenzene, 2,5-diaminobrombenzene, and aminoanisidine as aromatic diamines. , 1,5-naphthylenediamine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylketone, 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenylmethane and the like, while aromatics. Examples of the dicarboxylic acid halide include terephthalic acid chloride, 1,4-naphthalenedicarboxylic acid chloride, 2,6-naphthalenedicarboxylic acid chloride, 4,4'-biphenyldicarboxylic acid chloride, 4,4'-diphenylether dicarboxylic acid chloride and the like. ..

If the copolymerization ratio of these copolymerization components is too large, the characteristics of the meta-type total aromatic polyamide tend to deteriorate. Therefore, the copolymerization ratio is preferably 20 mol% or less based on the total acid component of the polyamide. In particular, a suitable meta-type total aromatic polyamide is a polyamide in which 80 mol% or more of all repeating units are composed of metaphenylene isophthalamide units, and polymetaphenylene isophthalamide is particularly preferable.

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

Next, the spinning dope is adjusted by dissolving the meta-type total aromatic polyamide obtained here in a solvent that dissolves it. However, it is also possible to use the meta-type total aromatic polyamide as it is without isolation after polymerization. .. An amide-based solvent can be generally used as the solvent used here, and the main amide-based solvents are N-methyl-2-pyrrolidone (hereinafter, may be referred to as NMP) and dimethylformamide (hereinafter, DMF). (Sometimes referred to as), dimethylacetamide (hereinafter, sometimes referred to as DMAc) and the like can be exemplified. Among these, it is preferable to use NMP or DMAc from the viewpoint of solubility and handling safety.

As the solution concentration, an appropriate concentration may be appropriately selected from the viewpoint of the coagulation rate in the spinning / coagulation step, which is the next step, 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 preferably in the range of 10 to 30% by mass.

In the present invention, in order to obtain a highly visible original fiber required by the market, a pigment is added to the spun dope in an amount of 0.1 to 10.0% by mass per polymer component. The higher the addition concentration, the more the color of the fiber itself is concealed and the durability is improved, resulting in a brighter hue. The addition range is 5.0% by mass, and an even more preferable addition range is 1.0 to 3.0% by mass.

The pigment used here is a yellowish fluorescent pigment, and a pigment having a property of being insoluble in a 70% by mass aqueous solution of an organic solvent used for spinning doping is selected and added. Here, the yellowish fluorescent pigment has a chromaticity coordinate (x, y) according to CIE 15.2 of the finally obtained original meta-type total aromatic polyamide fiber (0.387, 0.610). , (0.356, 0.494), (0.398, 0.452) and (0.460, 0.540). When the fluorescent pigment is not a yellowish pigment as described above, it is difficult to obtain high visibility from the viewpoint of hue.

Further, the yellow fluorescent pigment needs to have a property of being insoluble in a 70% by mass aqueous solution of an organic solvent used for spinning doping. Here, "does not dissolve in a 70% by mass aqueous solution of the organic solvent used for spinning dope" means that the pigment component is left in a 70% by mass aqueous solution of the organic solvent used for producing the spinning dope at room temperature for 24 hours. A state in which 99% by mass or more is not dissolved.

When the yellow fluorescent pigment is dissolved in a 70% by mass aqueous solution of an organic solvent used for spinning doping, the pigment also falls off together with this solvent during fiber molding. If the pigment is not added, the performance cannot be exhibited, and the processing is inefficient and inappropriate.

Specific yellowish fluorescent pigments include, but are not limited to, Pigment Yellow 191 and Solvent Yellow 98.

Further, the yellow fluorescent pigment is often used in the pigment manufacturing process, and it is desirable that the yellow fluorescent pigment is a fluorescent pigment that does not contain benzene chloride, which is one of the harmful chemical substances that easily remain afterwards.

In the present invention, it is possible to use a small amount of a pigment other than the above-mentioned yellow fluorescent pigment in order to further adjust the color. Pigments used to adjust the color include organic pigments such as azo, phthalocyanine, perinone, perylene, and anthraquinone, or inorganic pigments such as carbon black, ultramarine, red iron oxide, titanium oxide, and iron oxide. However, the present invention is not limited to these.

When the yellow fluorescent pigment and other pigments are used in combination as described above, the ratio of the yellow fluorescent pigment to the total pigment is preferably 90% by mass or more in order to reduce the amount of harmful substances mixed in as much as possible. Is 95% by mass or more.

Next, the spun dope prepared as described above is spun into a coagulation liquid and coagulated. The 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 hole shape, etc. of the spinneret need not be particularly limited as long as it can be stably wet-spun. For example, the number of holes is 500 to 30,000 and the spinning hole diameter is 0.05. A multi-hole spinneret or the like for a rayon of ~ 0.2 mm may be used.

The temperature of the spinning dope when spinning from the spinneret is preferably in the range of 10 to 90 ° C.

As an example of the coagulation bath used to obtain the fibers of the present invention, an aqueous solution of an amide-based solvent containing no inorganic salt and having a concentration of 45 to 60% by mass is used in a bath solution temperature range of 10 to 35 ° C. If the concentration of the amide-based solvent is less than 45% by mass, the skin layer has a thick structure, the cleaning efficiency in the cleaning step is lowered, and the solvent remains in the final fibers. Further, when the concentration of the amide-based solvent exceeds 60% by mass, uniform solidification cannot be performed up to the inside of the fiber, which causes many problems such as cutting of the single yarn during the fiber molding process. To do. The time for immersing the fibers in the coagulation bath is appropriately in the range of 0.1 to 30 seconds.

Next, while the fibers obtained by coagulation in the coagulation bath are in the plastic state, the fibers are drawn in the plastic drawing bath. The plastic stretched bath liquid is not particularly limited, and conventionally known bath liquids can be used.

In order to obtain the fiber of the present invention, the draw ratio in the plastic drawing bath needs to be 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, it is possible to promote the removal of the solvent from the coagulated yarn by performing plastic drawing in a plastic drawing bath within a range of a specific magnification.

When the draw ratio in the plastic drawing bath is less than 3.5 times, the solvent removal from the coagulated yarn becomes insufficient. In addition, the breaking strength becomes insufficient, and handling in a processing process such as a spinning process becomes difficult. On the other hand, when the draw ratio exceeds 5.0 times, single yarn breakage occurs, resulting in poor process stability.

The temperature of the plastic stretching bath is preferably in the range of 10 to 90 ° C. The process stability is preferably good when the temperature is in the range of 20 to 90 ° C.

Next, the solvent remaining in the fiber is washed. In this step, the fibers stretched in the plastic stretching bath are thoroughly washed. Cleaning is preferably performed in multiple stages because it affects the quality of the obtained fibers. In particular, the temperature of the washing bath and the concentration of the amide solvent in the washing bath liquid in the washing step affect the extraction state of the amide solvent from the fibers and the infiltration state of water from the washing bath into the fibers. For this reason, it is preferable to control the temperature conditions and the concentration conditions of the amide-based solvent by setting the cleaning steps in multiple stages also for the purpose of optimizing these states.

The temperature conditions for washing and the concentration conditions for the amide-based solvent are not particularly limited as long as the quality of the finally obtained fiber can be satisfied. However, when the temperature of the first washing bath is set to a high temperature of 60 ° C. or higher, water infiltrates into the fibers at once, so that huge voids are generated in the fibers, which causes deterioration of quality. Therefore, the first washing bath is preferably at a low temperature of 30 ° C. or lower.

When the solvent remains in the fiber, it lowers the flame retardancy of the fiber and is also preferable in terms of environmental safety in processing the product using the fiber and using the product formed by using the fiber. Absent. Therefore, the amount of the solvent contained in the fiber used in the present invention is 0.2% by mass or less, more preferably 0.15% by mass or less, and particularly preferably 0.1% by mass or less.

Next, in the dry heat treatment step, the fibers that have undergone the washing step are dried and heat treated. The method of dry heat treatment is not particularly limited, and examples thereof include a method using a hot roller, a hot plate, and the like. By undergoing a dry heat treatment, the meta-type total aromatic polyamide fiber used in the present invention can be finally obtained.

In order to obtain the highly visible meta-type total aromatic polyamide fiber used in the present invention, after performing a dry heat treatment at 100 ° C. for drying, 5 seconds or less each time in the range of 280 to 310 ° C. It is necessary to repeat the dry heat treatment at least twice, and it is more preferable to carry out the dry heat treatment in the range of 290 to 300 ° C. When the heat treatment temperature is less than 280 ° C., the crystallization of the fiber becomes insufficient and the shrinkage of the fiber becomes high. On the other hand, when the temperature exceeds 310 ° C. or when the treatment is performed for 5 seconds or more each time, the yellow fluorescent pigment absorbs heat energy excessively, causing a structural change in addition to the excited state, and the hue changes. There is a problem that it ends up. Here, the dry heat treatment performed in the range of 280 to 310 ° C. contributes to the improvement of the breaking strength of the obtained fiber.

If necessary, the meta-type total aromatic polyamide fiber that has been subjected to the dry heat treatment may be further crimped. Further, after the crimping process, the fiber may be cut to an appropriate fiber length and provided for the next step. In some cases, it may be wound as a multifilament yarn.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to these examples.

Unless otherwise specified, "parts" and "%" in the examples are all based on the mass standard, and the quantity ratio indicates the mass ratio unless otherwise specified. Each physical property value in Examples and Comparative Examples was measured by the following method.

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

<Benzene chloride content of yellow fluorescent pigment>
The benzene chloride content was obtained by measuring dichlorobenzene, which is one of them, in accordance with Ecotex Standard 100 at an Ecotex certification body. In the present invention, when this content is 0.5% by mass or less, it is determined that "benzene chloride is not contained".
The amount of benzene chloride can be substantially "free of benzene chloride" by adopting the following cleaning method.
(Washing method)
Water is introduced into the yellow fluorescent pigment, and then the mixture is heated and pressurized at a pressure of 310 kPa and a temperature of 130 ° C., and stirred for 180 minutes or more. Then, only the pigment is isolated by filtration or the like, and the water content is sufficiently dried and removed.

<Fineness>
Based on JIS L1015, the measurement of the positive fineness according to the A method was carried out, and the apparent fineness was expressed.

<Breaking strength, breaking elongation>
Based on JIS L1015, the values measured under the following conditions using model number 5565 manufactured by Instron were used as the breaking strength and breaking elongation of the fiber.
(Measurement condition)
Grab interval: 20 mm
Initial load: 0.044cN (1 / 20g) / dtex
Tensile rate: 20 mm / min

<Flame-retardant LOI>
After opening the raw cotton with a card machine, a needle punch is used to prepare a felt for measurement with ^{a basis weight of 100 g / m 2.} The LOI was determined based on the LOI measurement method of JIS K7201.

<Saturation coordinates (x, y) according to CIE 15.2>
The raw cotton was well opened, the fibers were aligned and placed in a cell for measurement, and the chromaticity coordinates (x, y) according to CIE 15.2 were obtained using a spectrocolorimeter SD7000 (manufactured by Nippon Denshoku Kogyo Co., Ltd.).

<Brightness rate β>
A spun yarn (count: 20/2) is produced from raw cotton through a normal spinning process, and a woven fabric (grain: 280 g / m ² , thickness: 0.8 mm) woven from the spun yarn into a 2/1 twill weave is used for measurement. Made in. The brightness rate β corresponding to EN ISO20471 was measured by a fluorescence colorimeter at the Nissenken Quality Evaluation Center.

[Example 1]
(Manufacturing of polymer)
721.5 parts by mass of N, N-dimethylacetamide (DMAc) having a water content of 100 ppm or less was weighed in a reaction vessel under a dry nitrogen atmosphere, and 97.2 parts by mass (50.18 mol) of meta-phenylenediamine was contained in the DMAc. %) Was dissolved and cooled to 0 ° C. To this cooled DMAc solution, 181.3 parts by mass (49.82 mol%) of isophthalic acid 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 was 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 transparent polymer solution.

When polymetaphenylene isophthalamide was isolated from the obtained polymer solution and IV was measured, it was 1.65. The polymer concentration in the polymer solution was 17% by mass.

(Manufacturing of dope)
A powder obtained by mixing the yellow fluorescent pigment Solvent Yellow 98 in a ratio of 98.0% by mass and the fluorescent pigment Pigment Blue 61 in a ratio of 2.0% by mass in the obtained polymer solution was added to 2.0% by mass with respect to the mass of the polymer component. After the addition, the polymer solution was sufficiently stirred to evenly disperse the pigment. This was defoamed under reduced pressure to give a spinning dope.

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

Subsequently, stretching was carried out at a stretching ratio of 3.7 times in a plastic stretching bath having a composition of water / DMAc = 45/55 at a temperature of 40 ° C.

After stretching, washing is performed in a bath of 20 ° C. water / DMAc = 70/30 (immersion length 1.8 m), then in a water bath of 20 ° C. (immersion length 3.6 m), and further in a warm water bath of 60 ° C. (immersion length 5). It was thoroughly washed by passing it through 0.4 m).

The washed fibers are subjected to dry heat treatment for 5 seconds four times with a hot roller having a surface temperature of 290 ° C., passed through a crimper, crimped, and then cut with a cutter to obtain 51 mm short fibers. Got

The raw cotton physical characteristics obtained were a fineness of 1.67 dtex, a strength of 3.51 cN / dtex, an elongation of 35.5%, and an LOI of 28. The chromaticity coordinates (x, y) of this raw cotton according to CIE 15.2 are (0.416, 0.510), and the brightness rate β of the fabric produced from this raw cotton is 0.72, which is highly visible. It became a thing. These results are shown in Table 1.

[Comparative Example 1]
The fibers after spinning, drawing, and washing of Example 1 were carried out in the same manner as in Example 1 except that the fibers were subjected to dry heat treatment for 7 seconds four times with a thermal roller having a surface temperature of 320 ° C.

The raw cotton physical characteristics obtained were a fineness of 1.66 dtex, a strength of 3.58 cN / dtex, an elongation of 36.2%, and an LOI of 28. The chromaticity coordinates (x, y) of this raw cotton according to CIE 15.2 are (0.421, 0.468), and the brightness rate β of the fabric produced from this raw cotton is 0.53, which is sufficient visibility. It didn't turn out to be anything. These results are shown in Table 1.

[Example 2]
2. A powder prepared by mixing the yellow fluorescent pigment Solvent Yellow 98 in a ratio of 98.5% by mass and the non-fluorescent pigment Pigment Blue 15 in a ratio of 1.5% by mass with the polymer solution prepared in Example 1 was added to the mass of the polymer component. After adding to 0% by mass, the polymer solution was sufficiently stirred to uniformly disperse the pigment. This was carried out in the same manner as in Example 1 except that this was defoamed under reduced pressure to form a spinning dope.

The raw cotton physical characteristics obtained were a fineness of 1.69 dtex, a strength of 3.53 cN / dtex, an elongation of 37.2%, and an LOI of 28. The chromaticity coordinates (x, y) of this raw cotton according to CIE 15.2 are (0.424, 0.506), and the brightness rate β of the fabric produced from this raw cotton is 0.71 with high visibility. It became a thing. These results are shown in Table 1.

[Comparative Example 2]
A powder obtained by mixing the non-fluorescent pigment Pigment Yellow83 in a proportion of 99.0% by mass and the non-fluorescent pigment Pigment Blue15 in a proportion of 1.0% by mass with the polymer solution produced in Example 1 was mixed by 2.0% by mass with respect to the mass of the polymer component. After the addition was made to%, the polymer solution was sufficiently stirred to uniformly disperse the pigment. This was carried out in the same manner as in Example 1 except that this was defoamed under reduced pressure to form a spinning dope.

The raw cotton physical characteristics obtained were a fineness of 1.70 dtex, a strength of 3.55 cN / dtex, an elongation of 34.7%, and an LOI of 28. The chromaticity coordinates (x, y) of this raw cotton according to CIE 15.2 are (0.412, 0.457), and the brightness rate β of the fabric produced from this raw cotton is 0.34, which is sufficient visibility. It didn't turn out to be anything. These results are shown in Table 1.

[Example 3]
A powder prepared by mixing the yellow fluorescent pigment Solvent Yellow 98 as a colorant in a proportion of 98.0% by mass and the fluorescent pigment Pigment Blue 61 in a proportion of 2.0% by mass with respect to the mass of the polymer component was added to the polymer solution produced in Example 1. After adding to 0.5% by mass, the polymer solution was sufficiently stirred to uniformly disperse the pigment. This was carried out in the same manner as in Example 1 except that this was defoamed under reduced pressure to form a spinning dope.

The raw cotton physical characteristics obtained were a fineness of 1.70 dtex, a strength of 3.51 cN / dtex, an elongation of 33.9%, and an LOI of 29. The chromaticity coordinates (x, y) of this raw cotton according to CIE 15.2 are (0.397, 0.460), and the brightness rate β of the fabric produced from this raw cotton is 0.70, which is highly visible. It became a thing. These results are shown in Table 1.

[Comparative Example 3]
A powder obtained by mixing the polymer solution produced in Example 1 with the fluorescent pigment Solvent Yellow 98 as a colorant at a ratio of 98.0% by mass and the fluorescent pigment Pigment Blue 61 at a ratio of 2.0% by mass was mixed with respect to the mass of the polymer component. After adding to 3% by mass, the polymer solution was sufficiently stirred to uniformly disperse the pigment. This was carried out in the same manner as in Example 1 except that this was defoamed under reduced pressure to form a spinning dope.

The raw cotton physical characteristics obtained were a fineness of 1.68 dtex, a strength of 3.57 cN / dtex, an elongation of 36.3%, and an LOI of 29. The chromaticity coordinates (x, y) of this raw cotton according to CIE 15.2 are (0.380, 0.440), and the brightness rate β of the fabric produced from this raw cotton is 0.60, which is sufficient visibility. It didn't turn out to be anything. These results are shown in Table 1.

[Example 4]
A powder prepared by mixing the polymer solution produced in Example 1 with the fluorescent pigment Solvent Yellow 98 as a colorant at a ratio of 99.0% by mass and the non-fluorescent pigment Pigment Blue 15 at a ratio of 1.0% by mass was added to 10 by mass with respect to the mass of the polymer component. After adding to 0.0% by mass, the polymer solution was sufficiently stirred to uniformly disperse the pigment. This was carried out in the same manner as in Example 1 except that this was defoamed under reduced pressure to form a spinning dope.

The raw cotton physical characteristics obtained were a fineness of 1.70 dtex, a strength of 3.05 cN / dtex, an elongation of 27.3%, and an LOI of 27. The chromaticity coordinates (x, y) of this raw cotton according to CIE 15.2 are (0.433, 0.527), and the brightness rate β of the fabric produced from this raw cotton is 0.75, which is highly visible. It became a thing. These results are shown in Table 1.

[Comparative Example 4]
A powder prepared by mixing the polymer solution produced in Example 1 with the fluorescent pigment Solvent Yellow 98 as a colorant at a ratio of 99.0% by mass and the non-fluorescent pigment Pigment Blue 15 at a ratio of 1.0% by mass was added to the mass of the polymer component. After adding to 0.0% by mass, the polymer solution was sufficiently stirred to uniformly disperse the pigment. This was carried out in the same manner as in Example 1 except that this was defoamed under reduced pressure to form a spinning dope.

The raw cotton physical characteristics obtained were as low as 1.68 dtex in fineness, 2.63 cN / dtex in strength, 25.3% in elongation, and 26 in LOI. The chromaticity coordinates (x, y) of this raw cotton according to CIE 15.2 are (0.438, 0.550), and the luminance rate β of the fabric produced from this raw cotton is 0.75, which is highly visible. However, it was inadequate as a raw cotton material. These results are shown in Table 1.

According to the present invention, a meta-type all-aromatic polyamide fiber capable of achieving high visibility and weight reduction in protective clothing and work clothes having excellent flame retardant performance worn by firefighters and workers performing fire work can be provided. Since it can be obtained, its industrial value is extremely large.

Claims (4)

A meta-type total aromatic polyamide fiber containing 0.5 to 10.0% by mass of a yellow-based fluorescent pigment, wherein the yellow-based fluorescent pigment is an organic solvent used for producing the meta-type total aromatic polyamide. It is insoluble in a 70 mass% aqueous solution, and the chromaticity coordinates (x, y) of the meta-type total aromatic polyamide fiber according to CIE 15.2 are (0.387, 0.610), (0.356, 0. 494), (0.398, 0.452) and (0.460, 0.540) are within the range of the color space, and the brightness rate β is 0.70 or more. Original meta-type total aromatic polyamide fiber. The original meta-type total aromatic polyamide fiber according to claim 1, wherein the yellow fluorescent pigment does not contain benzene chloride. The entire original meta-type according to claim 1 or 2, wherein the original meta-type total aromatic polyamide fiber has a LOI of 27 or more, a strength of 3.0 cN / dtex or more, and an elongation of 27.0% or more. Aromatic polyamide fiber. A yellow fluorescent pigment was added in an amount of 0.5 to 10.0% by mass to a spinning dope obtained by dissolving a meta-type total aromatic polyamide in a solvent, spun-stretched through a spinneret, and the solvent was removed by washing with water. , 280-310 ° C. dry heat treatment was repeated at least twice for 5 seconds or less at a time, and the chromaticity coordinates (x, y) according to CIE 15.2 of the fiber were set to (0.387, 0.610). All of the original metatypes, characterized in that they are within the color space enclosed by (0.356, 0.494), (0.398, 0.452) and (0.460, 0.540). A method for producing an aromatic polyamide fiber.