JP2009120976A - Easily dyeable meta-type wholly aromatic polyamide fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide easily dyeable meta-type wholly aromatic polyamide fibers which are excellent in dyeability with dyes and has the strength and thermal shrinkage stability of the fibers. <P>SOLUTION: The easily dyeable meta-type wholly aromatic polyamide fibers, having a raw fiber breaking strength of ≥2.5 cN/dtex, and a 300°C dry heat shrinkage ratio of ≤2.5 before and after dyed, and giving dyed fibers having brightness coefficient L* value of ≤25, are obtained by subjecting fibers to a steam heat treatment under relaxation after a plasticizing drawing process and a water-washing process and before a dry heat treatment. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a readily dyeable meta-type wholly aromatic polyamide fiber having good dyeability for dyes such as cationic dyes and disperse dyes, and excellent in fiber strength and heat shrinkage stability.

  Meta-type wholly aromatic polyamide fibers such as polymetaphenylene terephthalamide fiber exhibit excellent heat resistance and dimensional stability because most of the molecular skeleton is composed of aromatic rings. Taking advantage of these characteristics, meta-type wholly aromatic polyamide fibers are used not only for industrial applications but also for applications where heat resistance, flame resistance and flame resistance are important. Recently, flame resistance Applications for fields such as bedding, clothing, and interiors that take advantage of flameproofness are rapidly expanding.

  Here, in the fields of bedding, clothing, interior, etc., colored fibers are required from the viewpoint of aesthetics and visibility. At the same time, excellent fiber strength and heat shrink stability are also required.

  Therefore, as a method for coloring the meta-type wholly aromatic polyamide fiber, a method in which a specific pigment is contained in the spinning solution in the fiber production process has been proposed (see Patent Document 1). However, the addition of pigments in the fiber manufacturing process is difficult to produce for small lots due to a large manufacturing loss when changing lots, and it is difficult to obtain any required hue. was there.

  Another coloring method for meta-type wholly aromatic polyamide fibers is a dyeing method. However, although the meta-type wholly aromatic polyamide fiber has excellent physical properties in terms of flame resistance and flame resistance, there is a problem that it is difficult to dye by a normal method due to its rigid polymer molecular chain. there were.

  Therefore, as a method for improving the dyeability of the meta-type wholly aromatic polyamide fiber, there is a method of adding an alkylbenzenesulfonic acid onium salt to the spinning solution to obtain a meta-type aromatic polyamide fiber that is easily dyeable with respect to the cationic dye. It has been proposed (see Patent Document 2). According to this method, a meta-type aromatic polyamide fiber having good dyeability can be obtained for the cationic dye. However, the addition of the onium salt increases the cost, and there is a problem that the setting of conditions must be strictly controlled so that the onium salt does not fall out of the fiber during spinning or post-processing.

  Therefore, according to the method of improving the colorability and dyeability by adding pigments and additives in the manufacturing process, it is possible to impart colorability and dyeability, but the difficulty of hue control, production efficiency, and cost increase. Problems such as process increase and severe process control have occurred.

  Therefore, as another method for imparting good dyeability without using an additive or the like during the fiber manufacturing process, a coagulated yarn obtained by wet spinning an amide solvent solution is used in an aqueous bath containing a solvent and a solubilized salt. After hot drawing, all the solvent and solubilized salt remaining in the drawn yarn in an aqueous bath are then extracted and washed, and further subjected to steam treatment in a substantially untensioned state, and then substantially tensioned. There has been proposed a method of drying at 10 to 150 ° C. in a non-contaminated state (see Patent Document 3).

  According to this method, it is possible to obtain meta-type wholly aromatic polyamide fibers having not only good dyeability but also good heat shrinkage stability among properties required in the fields of bedding, clothing, interiors and the like. However, since the fiber becomes a porous fiber in which a large number of microvoids having a diameter of about 0.1 μm are formed, the strength, which is another required characteristic, is not satisfactory.

  As another method, the amorphous fiber having pores is formed, the fiber swollen with water is steam-heated, and the dye is contained throughout the fiber structure by diffusing the dye into the pores of the fiber. And then the steam is heated for a sufficient time at a temperature higher than the glass transition temperature to crush the pores, thereby irreversibly trapping the dye in the fiber, A method for crystallizing fibers has been proposed (see Patent Document 4).

  According to this method, it is possible to obtain a fiber having good dyeability and stable against washing shrinkage. However, there is a problem that the thermal shrinkage stability before and after dyeing is poor and the fiber shrinks due to dyeing. For this reason, in the method of patent document 4, there existed a problem that it accompanied with difficulty in the design of a fiber structure.

  On the other hand, a method for producing a meta-type wholly aromatic polyamide fiber having good dyeability and having both fiber strength and heat shrinkage stability has been proposed (see Patent Document 5). In Patent Document 5, coagulation is performed in an aqueous coagulation bath containing an inorganic salt, and the obtained coagulated yarn is washed in an aqueous washing bath, then stretched in a warm water bath, and further in a fiber in a warm water bath. A series of steps is described in which the inorganic salt is removed, followed by relaxation heat treatment in water vapor under specific conditions, and further stretching in water vapor under specific conditions.

  However, the fiber obtained by the method described in Patent Document 5 is still unsatisfactory in terms of dyeability and heat shrink stability, and further improvement has been demanded. Further, the method described in Patent Document 5 has a problem that the process becomes complicated and the initial investment cost increases due to an increase in steam heating equipment. Therefore, a simpler manufacturing method has been demanded.

JP 50-059522 A Japanese Patent Application Laid-Open No. 08-081827 Japanese Patent Publication No. 50-013846 Japanese Patent Laid-Open No. 62-184127 Japanese Patent Laying-Open No. 2005-042662

  The present invention has been made in view of the above-described background art, and the object thereof is excellent dyeability for dyes, and further, easy-dyeing meta-type having both fiber strength and heat shrink stability. The object is to provide a wholly aromatic polyamide fiber.

  The present inventors have made extensive studies in view of the above problems. As a result, it has been found that the above-mentioned problems can be solved by performing a water vapor relaxation heat treatment after the plastic drawing and water washing steps and before the dry heat treatment, and the present invention has been completed.

  That is, according to the present invention, easy dyeing in which the breaking strength of the fibril is 2.5 cN / dtex or more, the ratio of the 300 ° C. dry heat shrinkage before and after dyeing is 2.5 or less, and the lightness index L * value of the dyed fiber is 25 or less. Meta-type wholly aromatic polyamide fiber.

  The easily dyeable meta-type wholly aromatic polyamide fiber of the present invention has excellent heat resistance, flame resistance, flame resistance, dyeability to dyes, and excellent fiber strength and heat shrinkage. Combines stability. For this reason, the industrial value in the field | area where these characteristics are required is very large, For example, it can use suitably also in the field | area which attaches importance to aesthetics and visual properties, such as bedding, clothing, and interior.

Hereinafter, the present invention will be described in detail.
<Easily dyeable meta-type wholly aromatic polyamide fiber>
The easily dyeable meta-type aromatic polyamide fiber of the present invention has the following specific physical properties. The physical properties, configuration, production method and the like of the easily dyeable meta-type aromatic polyamide fiber of the present invention will be described below.

[Physical properties of readily dyeable meta-type aromatic polyamide fibers]
〔Breaking strength〕
The breaking strength of the easy-dyeable meta-type aromatic polyamide fiber of the present invention (fiber before dyeing) is 2.5 cN / dtex or more. It is essential that it is 2.5 cN / dtex or more, preferably 2.7 cN / dtex or more, and more preferably 2.9 or more. When the breaking strength is less than 2.5 cN / dtex, the passability in post-processing steps such as spinning and dyeing deteriorates, which is not preferable.
The “breaking strength” in the present invention refers to a value obtained by measurement under the following conditions based on JIS L 1015.

(Measurement condition)
Grasp interval: 20mm
Initial load: 0.044 cN (1/20 g) / dtex
Tensile speed: 20 mm / min

  In the present invention, the breaking strength of the easily dyeable meta-type aromatic polyamide fiber can be controlled by optimizing the draw ratio in the plastic drawing step in the production method described later. In order to obtain 2.5 cN / dtex or more, the draw ratio may be 2.5 to 10.0 times.

[Ratio of 300 ° C dry heat shrinkage before and after dyeing]
The ratio of 300 ° C. dry heat shrinkage before and after dyeing (300 ° C. dry heat shrinkage before dyeing / 300 ° C. dry heat shrinkage after dyeing) of the easily dyeable meta-type wholly aromatic polyamide fiber of the present invention is 2.5 or less. It is. The ratio of the 300 ° C. dry heat shrinkage ratio before and after dyeing is essential to be 2.5 or less, preferably 2.3 or less, more preferably 2.2 or less, and most preferably 2.1 or less. In general, when the ratio of shrinkage ratios exceeds 2.5, fiber shrinkage occurs in the dyeing process, making it difficult to design a fibril structure.
In the present invention, “300 ° C. dry heat shrinkage” refers to a value obtained by the following method.

(300 ° C dry heat shrinkage)
A load of 98 cN (100 g) is hung on a tow of about 3300 dtex, and points 30 cm apart are marked. After removing the load, the tow is placed in an atmosphere of 300 ° C. for 15 minutes, and then the length L between the marks is measured. Based on the measurement result L, the value obtained by the following equation is defined as 300 ° C. dry heat shrinkage (%).
300 ° C. dry heat shrinkage (%) = (30−L) / 30 × 100

(Ratio of 300 ° C dry heat shrinkage before and after dyeing)
By the measurement / calculation method described above, the 300 ° C. dry heat shrinkage of the original fiber and the 300 ° C. dry heat shrinkage of the dyed fiber are determined. Using the obtained results, the value obtained by the following formula is used as the ratio of the 300 ° C. dry heat shrinkage ratio before and after dyeing.
300 ° C. dry heat shrinkage ratio before and after dyeing = 300 ° C. dry heat shrinkage of the original fiber / 300 ° C. dry heat shrinkage of the dyed fiber

  The “staining” in the present invention means staining by the following staining method unless otherwise specified.

(Dyeing method)
Cationic dye (Nippon Kayaku Co., Ltd., trade name: Kayacryl Blue GSL-ED (B-54)) 6% owf, acetic acid 0.3 mL / L, sodium nitrate 20 g / L, carrier agent benzyl alcohol 70 g / L, dispersion A dyeing solution containing 0.5 g / L of a dyeing assistant (manufactured by Meisei Chemical Co., Ltd., trade name: Disper TL) is prepared as an agent. Subsequently, the dyeing treatment is performed at 120 ° C. for 60 minutes with the bath ratio of the fiber and the dyeing solution being 1:40.

  In the present invention, the ratio of 300 ° C. dry heat shrinkage before and after dyeing of easily dyeable meta-aromatic polyamide fibers can be controlled by optimizing the relaxation ratio in the steam treatment step in the production method described later. . In order to set the ratio to 2.5 or less, the relaxation magnification may be set to 0.65 to 1.0.

[Lightness index L * value of dyed fiber]
The easily dyeable meta-type wholly aromatic polyamide fiber of the present invention has a lightness index L * value of the dyed fiber of 25 or less. A lightness index L * value exceeding 25 is not preferable because sufficient dyeability cannot be obtained.

  In addition, the “lightness index L * value” in the present invention refers to a value measured by the following measurement method on the fiber dyed by the above dyeing method. In addition, L * shows that it is deeply dyed, so that a numerical value is small.

(Measuring method)
Measurement is performed under the following measurement conditions using a color measuring device (trade name: Macbeth Color Eye Model CE-3100, manufactured by Masbek).
{Measurement condition}
Field of view: 10 degrees Light source: D65
Wavelength: 360-740 nm

  In the present invention, the lightness index L * value of the dyed fiber of the easily dyeable meta-type aromatic polyamide fiber can be controlled by optimizing the relaxation magnification in the steam relaxation heat treatment step in the production method described later. In order to set the lightness index L * value to 25 or less, the relaxation magnification may be set to 0.65 to 1.0.

[300 ° C dry heat shrinkage of fibrils]
The easily dyeable meta-type wholly aromatic polyamide fiber of the present invention preferably has a 300 ° C. dry heat shrinkage of the fibril before dyeing of 3.0% or less. The 300 ° C. dry heat shrinkage of the fibril is essential to be 3.0% or less, preferably 2.9% or less, and more preferably 2.8% or less. When the shrinkage rate exceeds 3.0%, it is not preferable because the product dimensions change when used in a high-temperature atmosphere and the product is damaged.
In addition, the 300 degreeC dry heat shrinkage rate of a fibril is measured with the measuring method of above-mentioned 300 degreeC dry heat shrinkage rate.

  In the present invention, the 300 ° C. dry heat shrinkage ratio of the easy-dyeable meta-type aromatic polyamide fiber base fiber can be controlled by optimizing the relaxation ratio in the steam relaxation heat treatment step in the production method described later. . In order to set the 300 ° C. dry heat shrinkage of the fibrils to 3.0% or less, the relaxation ratio may be set to 0.65 to 1.0.

[Dyeing rate of dyed fiber]
The dyeing rate of the dyed fiber dyed by the above dyeing method is preferably 90% or more in the easily dyeable meta-type wholly aromatic polyamide fiber of the present invention. The dyeing rate of the dyed fiber is essential to be 90% or more, and preferably 92% or more. If the dyeing rate of the dyed fiber is less than 90%, the amount of dye loss in the dyeing process increases, which increases the cost in the dyeing process, which is not preferable.
The “dyeing rate” in the present invention refers to a value obtained by the following method.

(Dyeing rate)
Add the same volume of dichloromethane as this dyeing residual solution to the dyeing residual solution dyed fibrils to extract the residual dye. Subsequently, with respect to the extract, the absorbance at wavelengths of 670 nm, 540 nm, and 530 nm was measured, respectively, and the dye concentration of the extract was determined from the calibration curve of the above three wavelengths prepared from a dichloromethane solution with a known dye concentration in advance. Let the average value of density | concentration be the dye density | concentration (C) of an extract. Using the dye concentration (Co) before dyeing, the value obtained by the following equation is defined as the dyeing rate (U).
Dyeing rate (U) = (Co−C) / Co × 100

  In this invention, the dyeing | staining rate of the dyeing | staining fiber of easily dyeable meta type | mold aromatic polyamide fiber can be controlled by optimizing a relaxation rate in the water vapor relaxation heat treatment process in the manufacturing method mentioned later. In order to set the dyeing rate of the dyed fibers to 90% or more, the relaxation magnification may be set to 0.65 to 1.0.

[Limited oxygen index (LOI) of dyed fiber]
The easily dyeable meta-type wholly aromatic polyamide fiber of the present invention preferably has a limiting oxygen index (LOI) of 30 or more of the dyed fiber dyed by the above dyeing method. The critical oxygen index (LOI) of the dyed fiber is essential to be 30 or more, preferably 30.5 or more, and more preferably 31.0 or more. When the limiting oxygen index (LOI) is less than 30, it is not preferable because the product may be ignited by high heat when used in a high temperature atmosphere.

  The “limit oxygen index (LOI)” in the present invention is a non-woven fabric obtained by forming a fibrous fiber material into a sheet shape by needle punching based on the LOI measurement method of JIS K 7201 under the following measurement conditions. The value obtained by measurement.

(Measurement condition)
Specimen shape: V
Dimensions: 140mm x 52mm
Ignition procedure: B (propagation ignition)
Oxygen concentration interval: 0.2%

  In the present invention, the limiting oxygen index (LOI) of dyed fibers of readily dyeable meta-aromatic polyamide fibers can be controlled by reducing the amount of residual solvent in the water washing step in the production method described later. In order to set the limiting oxygen index (LOI) of the dyed fiber to 30 or more, the residual solvent amount may be set to 0.1% or less.

[Configuration of meta-type aromatic polyamide]
The meta-type wholly aromatic polyamide constituting the easily dyeable meta-type aromatic polyamide fiber of the present invention is composed of a meta-type aromatic diamine component and a meta-type aromatic dicarboxylic acid component. Other copolymer components such as the para type may be copolymerized within a range not impairing the above.

  Particularly preferred for use in the present invention is a meta-aromatic polyamide mainly composed of a metaphenylene isophthalamide unit from the viewpoint of mechanical properties, heat resistance and flame retardancy. It is desirable that the meta-type wholly aromatic polyamide is composed of metaphenylene isophthalamide units, preferably 90 mol% or more, more preferably 95 mol% or more, particularly preferably 100 mol% of all repeating units.

[Raw material for meta-type aromatic polyamide]
(Meta-type aromatic diamine component)
Examples of the meta-type aromatic diamine component used as a raw material for the meta-type aromatic polyamide include metaphenylene diamine, 3,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl sulfone, and the like. Examples of derivatives having substituents such as alkyl groups of 1 to 3, such as 2,4-toluylenediamine, 2,6-toluylenediamine, 2,4-diaminochlorobenzene, 2,6-diaminochlorobenzene, etc. be able to. Of these, metaphenylenediamine alone or a mixed diamine containing metaphenylenediamine in an amount of 85 mol% or more, preferably 90 mol% or more, particularly preferably 95 mol% or more is preferable.

(Meta-type aromatic dicarboxylic acid component)
Examples of the raw material of the meta type aromatic dicarboxylic acid component constituting the meta type aromatic polyamide include a meta type aromatic dicarboxylic acid halide. Examples of the meta-type aromatic dicarboxylic acid halide include isophthalic acid halides such as isophthalic acid chloride and isophthalic acid bromide, and derivatives having substituents such as halogen and alkoxy groups having 1 to 3 carbon atoms on the aromatic ring, such as 3 -Chloroisophthalic acid chloride etc. can be illustrated. Of these, isophthalic acid chloride itself or a mixed carboxylic acid halide containing isophthalic acid chloride in an amount of 85 mol% or more, preferably 90 mol% or more, particularly preferably 95 mol% or more is preferable.

[Method for producing meta-type aromatic polyamide]
The production method of the meta-type aromatic polyamide is not particularly limited, and for example, it may be produced by solution polymerization or interfacial polymerization using a meta-type aromatic diamine component and a meta-type aromatic dicarboxylic acid chloride component as raw materials. Can do.

<Method for Producing Easily Dyeable Meta-type Aromatic Polyamide Fiber>
The easily dyeable meta-type aromatic polyamide fiber of the present invention uses the aromatic polyamide obtained by the above production method, for example, a spinning solution preparation process, a spinning / coagulation process, and a plastic stretching bath stretching process described below. It is manufactured through a washing process, a relaxation treatment process, and a heat treatment process.

[Spinning liquid preparation process]
In the spinning solution preparation step, the meta type wholly aromatic polyamide is dissolved in an amide solvent to prepare a spinning solution (meta type wholly aromatic polyamide polymer solution). In preparing the spinning solution, an amide solvent is usually used, and examples of the amide solvent used include N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), and dimethylacetamide (DMAc). be able to. Of these, NMP or DMAc is preferably used from the viewpoints of solubility and handling safety.

  The concentration of the solution may be appropriately selected from the viewpoint of the coagulation rate and the solubility of the polymer in the next spinning and coagulation step. For example, the polymer is polymetaphenylene isophthalamide and the solvent is NMP. In the case of, it is usually preferred to be in the range of 10 to 30% by mass.

[Spinning and coagulation process]
In the spinning / coagulation step, the spinning solution (meta-type wholly aromatic polyamide polymer solution) obtained above is spun 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 and the like of the spinneret are not particularly limited as long as they can be stably wet-spun. For example, the number of holes is 1,000 to 30,000, and the spinning hole diameter is 0.05. A multi-hole spinneret for ˜0.2 mm sufu may be used.
The temperature of the spinning solution (meta-type wholly aromatic polyamide polymer solution) when spinning from the spinneret is suitably in the range of 20 to 90 ° C.

The coagulation bath is not particularly limited, and a conventionally known bath solution can be used. For example, when an aqueous coagulation bath not containing an inorganic salt is employed, an aqueous solution having an NMP concentration of 40 to 70% by mass can be used as a temperature range of the bath solution of 20 to 90 ° C. In this case, the fiber immersion time in the coagulation bath is suitably in the range of 0.1 to 30 seconds.
In the present invention, by appropriately adjusting the components or conditions of the coagulation bath, the skin formed on the fiber surface can be thinned, and as a result, the dyeability can be further improved.

[Plastic stretching bath stretching process]
In the plastic drawing bath drawing step, the fiber is drawn in the plastic drawing bath while the fiber obtained by coagulation in the coagulation bath is in a plastic state.
It does not specifically limit as a plastic drawing bath liquid, A conventionally well-known thing can be employ | adopted.

  The draw ratio is preferably in the range of 2.5 to 10.0 times, more preferably 2.5 to 6.0 times. In the present invention, raising the molecular chain orientation by stretching in a plastic stretching bath is important for ensuring the balance between heat shrink stability and strength of the easily dyeable fiber finally obtained.

When the draw ratio in the plastic drawing bath is less than 2.5 times, it becomes difficult to obtain a fiber having a breaking strength of 2.5 cN / dtex or more and sufficient heat shrink stability. On the other hand, when the draw ratio exceeds 10.0 times, single yarn breakage occurs, resulting in poor production stability.
The temperature of the plastic stretching bath is preferably in the range of 20 to 90 ° C. It is preferable that the temperature is in the range of 20 to 90 ° C. because the process condition is good.

[Washing process]
In the washing step, the fiber drawn in the plastic drawing bath is thoroughly washed. Washing is preferably performed in multiple stages because it affects the quality of the resulting fiber. In particular, the temperature of the cleaning bath in the cleaning step and the concentration of the amide solvent in the cleaning bath liquid affect the state of extraction of the amide solvent from the fibers and the state of penetration of water from the cleaning bath into the fibers. For this reason, it is preferable to control the temperature condition and the concentration condition of the amide solvent by setting the washing process in multiple stages for the purpose of bringing these into an optimum state.

The temperature condition and the concentration condition of the amide solvent are not particularly limited as long as the quality of the finally obtained fiber can be satisfied, but if the initial washing bath is at a high temperature of 60 ° C. or higher, water Intrusion into the fiber occurs at once, and a huge void is formed in the fiber, resulting in deterioration of quality. For this reason, it is preferable that the first washing bath has a low temperature of 30 ° C. or lower.
When the solvent remains in the fiber, the physical properties and shrinkage at a high temperature, the limiting oxygen index (LOI), etc. are reduced. For this reason, the amount of solvent contained in the fiber is preferably 1% or less, and more preferably 0.1% or less.

[Water vapor relaxation heat treatment process]
In the relaxation heat treatment step, the fibers washed in the washing step are subjected to relaxation heat treatment in water vapor, preferably saturated water vapor. By performing the relaxation heat treatment in water vapor, the amorphous portion inside the fiber is remarkably relaxed, the dyeability is improved, and shrinkage due to heat during dyeing can be suppressed.

  The water vapor pressure in the water vapor relaxation heat treatment step is preferably in the range of 196 to 392 kPa, and more preferably in the range of 225 to 363 kPa. When the water vapor pressure of the relaxation heat treatment is less than 196 kPa, sufficient orientation relaxation of the amorphous portion inside the fiber does not occur, and it becomes difficult to impart the desired heat shrinkage stability. On the other hand, if it exceeds 392 kPa, heat shrink stability can be imparted, but the fiber dyeability is greatly reduced, which is not preferable.

  Moreover, the relaxation ratio in the steam relaxation heat treatment step is preferably 0.65 to 1.0 times, and more preferably 0.65 to 0.95 times. When the relaxation ratio exceeds this range, sufficient orientation relaxation of the amorphous portion inside the fiber does not occur, and it becomes difficult to impart the desired heat shrinkage stability. Furthermore, since the orientation relaxation of the amorphous part inside the fiber becomes insufficient, the ratio of the 300 ° C. dry heat shrinkage before and after dyeing and the lightness index (L * value) of the dyed fiber increase, and the object of the present invention is It becomes difficult to achieve. Furthermore, the 300 ° C. dry heat shrinkage of the fibrils also increases, and as a result, the dyeing rate of the dyed fibers decreases. For this reason, in the present invention, the control of the relaxation rate in the steam relaxation heat treatment step is extremely important.

[Dry heat treatment process]
In the dry heat treatment step, the fiber that has undergone the water vapor relaxation heat treatment step is dried and heat treated. Although it does not specifically limit as dry heat processing, For example, the method of using a heat roller, a hot plate, etc. can be mentioned. Thereby, finally, the easily dyeable meta type wholly aromatic polyamide fiber of the present invention can be obtained.

  EXAMPLES Hereinafter, although an Example etc. are given and this invention is demonstrated further more concretely, this invention is not limited by these Examples etc.

<Measurement method>
Each physical property value in Examples and Comparative Examples was measured by the following method.

[Fineness]
Based on JIS L 1015, the measurement based on the A method of positive fineness was implemented, and it described with the apparent fineness.

[Break strength, elongation at break]
Based on JIS L 1015, it measured on condition of the following.
(Measurement condition)
Grasp interval: 20mm
Initial load: 0.044 cN (1/20 g) / dtex
Tensile speed: 20 mm / min

[300 ° C dry heat shrinkage]
A load of 98 cN (100 g) is hung on a tow of about 3300 dtex, and points 30 cm apart are marked. After removing the load, the tow was placed in an atmosphere of 300 ° C. for 15 minutes, and then the length L between the marks was measured. Based on the measurement result L, the value obtained by the following formula was defined as 300 ° C. dry heat shrinkage (%).
300 ° C. dry heat shrinkage (%) = (30−L) / 30 × 100

[Ratio of 300 ° C dry heat shrinkage before and after dyeing]
By the above measurement / calculation method, the 300 ° C. dry heat shrinkage of the fibrils and the 300 ° C. dry heat shrinkage of the dyed fibers were determined. Using the obtained results, the value obtained by the following formula was used as the ratio of 300 ° C. dry heat shrinkage before and after dyeing.
300 ° C. dry heat shrinkage ratio before and after dyeing = 300 ° C. dry heat shrinkage of the original fiber / 300 ° C. dry heat shrinkage of the dyed fiber

[Dyeing rate]
Add the same volume of dichloromethane as this dyeing residual solution to the dyeing residual solution dyed fibrils to extract the residual dye. Subsequently, with respect to the extract, the absorbance at wavelengths of 670 nm, 540 nm, and 530 nm was measured, respectively, and the dye concentration of the extract was determined from the calibration curve of the above three wavelengths prepared from a dichloromethane solution with a known dye concentration in advance. The average value of the concentration was defined as the dye concentration (C) of the extract. Using the dye concentration (Co) before dyeing, the value obtained by the following formula was used as the dyeing rate (U).
Dyeing rate (U) = (Co−C) / Co × 100

[Lightness index L * value of dyed fiber (tow)]
Measurement was carried out under the following measurement conditions using a color measuring device (trade name: Macbeth Color Eye Model CE-3100, manufactured by Masbek). In addition, L * shows that it is deeply dyed, so that a numerical value is small.
(Measurement condition)
Field of view: 10 degrees Light source: D65
Wavelength: 360-740 nm

[Limited oxygen index (LOI)]
Based on the LOI measurement method of JIS K 7201, the measurement was carried out under the following measurement conditions for a nonwoven fabric obtained by forming a cotton-like fiber material into a sheet by needle punching.
(Measurement condition)
Specimen shape: V
Dimensions: 140mm x 52mm
Ignition procedure: B (propagation ignition)
Oxygen concentration interval: 0.2%

<Example 1>
[Spinning liquid preparation process]
N-methyl-, prepared by interfacial polymerization in accordance with the method described in JP-B-47-10863, 20.0 parts by mass of polymetaphenylene isophthalamide powder having an intrinsic viscosity of 1.9, cooled to −10 ° C. It was suspended in 80.0 parts by mass of 2-pyrrolidone (hereinafter abbreviated as NMP) to form a slurry. Subsequently, the suspension was heated to 60 ° C. and dissolved to obtain a transparent polymer solution.

[Spinning and coagulation process]
The obtained polymer solution was spun as a spinning dope from a spinneret having a hole diameter of 0.07 mm and a hole number of 1500 into a coagulation bath at 40 ° C. The composition of the coagulation bath was 55% by mass of NMP and 45% by mass of water, and was spun by discharging into the coagulation bath at a yarn speed of 7 m / min.

[Plastic stretching bath stretching process]
Subsequently, the film was stretched at a stretch ratio of 5.2 times in a plastic stretching bath having a composition of water / NMP = 40/60 at a temperature of 40 ° C.

[Washing process]
After stretching, it is sequentially passed through a 20 ° C. water / NMP = 70/30 bath (immersion length 1.8 m), a 20 ° C. water bath (immersion length 3.6 m), and a 60 ° C. warm water bath (immersion length 5.4 m). And thoroughly washed.

[Water vapor relaxation heat treatment process]
The washed fibers were subjected to a steam relaxation heat treatment under a saturated steam pressure of 294 kPa and a relaxation factor of 0.80.

[Dry heat treatment process]
After the relaxation heat treatment, dry heat treatment was performed with a heat roller having a surface temperature of 350 ° C. to obtain polymetaphenylene isophthalamide fibers.

[Physical properties of fibrils]
The physical properties of the obtained fiber were a fineness of 1.95 dtex, a breaking strength of 3.02 cN / dtex, and a breaking elongation of 28.5%. Moreover, the 300 degreeC dry heat shrinkage rate was 3.0%, and showed the outstanding heat shrink stability. Table 1 shows the physical properties of the fibrils.

[Dyeing process]
Cationic dye (Nippon Kayaku Co., Ltd., trade name: Kayacryl Blue GSL-ED (B-54)) 6% owf, acetic acid 0.3 mL / L, sodium nitrate 20 g / L, carrier agent benzyl alcohol 70 g / L, dispersion A dyeing solution containing 0.5 g / L of a dyeing assistant (made by Meisei Chemical Co., Ltd., trade name: Disper TL) was prepared as an agent. The sample fiber was dyed for 60 minutes at 120 ° C. in a tow state with a bath ratio of the fiber to the dyeing solution of 1:40. After the dyeing treatment, hydrosulfite 2.0 g / L, amylazine D (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: amirazine D) 2.0 g / L, treatment solution containing sodium hydroxide 1.0 g / L Was used for reduction washing at a bath ratio of 1:20 at 80 ° C. for 20 minutes, followed by washing with water and drying to obtain dyed fibers.

[Physical properties of dyed fibers]
The dyeing rate of the dyed fiber was 90.4%, and the L * value was 25.0, indicating good dyeability. Further, the 300 ° C. dry heat shrinkage ratio before and after dyeing was 2.07, and it was found that the heat shrinkage ratio change was small. The limiting oxygen index (LOI value) was 30.5, indicating good flame retardancy. The obtained results are shown in Table 2.

<Example 2>
[Spinning liquid adjustment process]
85.48 parts of N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) is placed in a reaction vessel equipped with a stirrer and a raw material inlet, and metaphenylenediamine (hereinafter abbreviated as MPDA) in this NMP. 4 parts were dissolved. Further, 156.9 parts of isophthalic acid chloride (hereinafter abbreviated as IPC) was added to the solution while gradually stirring to carry out the reaction. After stirring for 40 minutes from the start of the reaction, 57.1 parts of calcium hydroxide powder was added, and the reaction was terminated after stirring for another 40 minutes. When the polymerization solution was taken out from the reaction vessel, the polymerization solution was transparent and the polymer concentration was 16%.

[Spinning / coagulation process, plastic drawing bath drawing process, washing process, steam relaxation heat treatment process, dry heat treatment process]
A polymetaphenylene isophthalamide fiber was obtained in the same manner as in Example 1 except that the obtained polymerization solution was used as a spinning dope and the draw ratio in a plastic drawing bath was 5.3 times and the water vapor relaxation ratio was 0.78 times. It was.

[Physical properties of fibrils]
The physical properties of the obtained fiber were a fineness of 2.25 dtex, a breaking strength of 2.92 cN / dtex, a breaking elongation of 26.9%, and a 300 ° C. dry heat shrinkage of 2.9%. Table 1 shows the physical properties of the obtained fiber.

[Dyeing process]
The dyeing process was implemented similarly to Example 1 with respect to the obtained fiber.

[Physical properties of dyed fibers]
The dyeing rate was 93.0%, and the L * value was 24.8, indicating good dyeability. Further, the 300 ° C. dry heat shrinkage ratio before and after dyeing was 2.10, and it was found that the heat shrinkage ratio change was small. The limiting oxygen index (LOI value) was 31.9, indicating good flame retardancy. The obtained results are shown in Table 2.

<Example 3>
[Manufacture of fibrils]
Polymetaphenylene isophthalamide fibers were obtained in the same manner as in Example 1 except that the draw ratio in the plastic drawing bath was 5.5 times and the water vapor relaxation ratio was 0.69 times.

[Physical properties of fibrils]
The physical properties of the obtained fiber were a fineness of 2.16 dtex, a breaking strength of 2.55 cN / dtex, a breaking elongation of 31.1%, and a 300 ° C. dry heat shrinkage of 2.7%. Table 1 shows the physical properties of the obtained fiber.

[Dyeing process]
The dyeing process was implemented similarly to Example 1 with respect to the obtained fiber.

[Physical properties of dyed fibers]
The dyeing rate was 90.2%, and the L * value was 24.9, indicating good dyeability. Further, the 300 ° C. dry heat shrinkage ratio before and after dyeing was 2.13, and it was found that the change in heat shrinkage rate was small. The limiting oxygen index (LOI value) was 31.0, indicating good flame retardancy.

<Comparative Example 1>
[Manufacture of fibrils]
Polymetaphenylene isophthalamide fiber was obtained in the same manner as in Example 1 except that the draw ratio in the plastic drawing bath was 2.4 times and the water vapor relaxation ratio was 0.90 times.

[Physical properties of fibrils]
The physical properties of the obtained fiber were a fineness of 1.78 dtex, a breaking strength of 1.78 cN / dtex, a breaking elongation of 25.4%, and a 300 ° C. dry heat shrinkage of 2.2%. Table 1 shows the physical properties of the obtained fiber.

[Dyeing process]
The dyeing process was implemented similarly to Example 1 with respect to the obtained fiber.

[Physical properties of dyed fibers]
The dyeing rate was 93.1%, and the L * value was 23.9, indicating good dyeability. Further, the 300 ° C. dry heat shrinkage ratio before and after dyeing was 2.10, and it was found that the heat shrinkage ratio change was small. The limiting oxygen index (LOI value) was 32.0, indicating good flame retardancy.

<Comparative example 2>
[Manufacture of fibrils]
A polymetaphenylene isophthalamide fiber was obtained in the same manner as in Example 3 except that the draw ratio in the plastic drawing bath was 5.0 times and the water vapor relaxation ratio was 1.05 times.

[Physical properties of fibrils]
The physical properties of the obtained fiber were a fineness of 2.02 dtex, a breaking strength of 3.54 cN / dtex, a breaking elongation of 27.1%, and a 300 ° C. dry heat shrinkage of 7.0%. Table 1 shows the physical properties of the obtained fiber.

[Dyeing process]
The dyeing process was implemented similarly to Example 1 with respect to the obtained fiber.

[Physical properties of dyed fibers]
The dyeing rate was 83.4%, and the L * value was 29.2, which was slightly inferior in dyeability. Further, the 300 ° C. dry heat shrinkage ratio before and after dyeing was 3.05, and it was found that the heat shrinkage rate change was large. The limiting oxygen index (LOI value) was 30.5, indicating good flame retardancy.

<Comparative Example 3>
[Manufacture of fibrils]
A polymetaphenylene isophthalamide fiber was obtained in the same manner as in Example 1 except that the draw ratio in the plastic drawing bath was 5.5 times and the steam relaxation treatment was not performed.

[Physical properties of fibrils]
The physical properties of the obtained fiber were a fineness of 2.12 dtex, a breaking strength of 3.25 cN / dtex, a breaking elongation of 31.1%, and a 300 ° C. dry heat shrinkage of 5.7%. Table 1 shows the physical properties of the obtained fiber.

[Dyeing process]
The dyeing process was implemented similarly to Example 1 with respect to the obtained fiber.

[Physical properties of dyed fibers]
The dyeing rate was 85.2%, and the L * value was 28.9, which was slightly inferior in dyeability. Further, the 300 ° C. dry heat shrinkage ratio before and after dyeing was 2.70, and it was found that the heat shrinkage ratio change was large. The limiting oxygen index (LOI value) was 30.2, indicating good flame retardancy.

<Comparative example 4>
[Manufacture of fibrils]
A polymerization solution obtained in the same manner as in Example 2 except that the solvent in the spinning solution preparation step was changed from NMP to dimethylacetamide (hereinafter abbreviated as DMAc) was used as a spinning stock solution, and described in JP-B-62-184127. Dry spinning was performed according to the method. The fiber exiting the drying tower was stretched 4.0 times in a 90 ° C. bath of DMAc 30% by mass, and crimped at 80 ° C. without passing through a water vapor relaxation step to obtain polymetaphenylene isophthalamide fiber. .

[Physical properties of fibrils]
The physical properties of the obtained fiber were a fineness of 1.55 dtex, a breaking strength of 3.40 cN / dtex, a breaking elongation of 56.1%, and a 300 ° C. dry heat shrinkage of 15.7%. Table 1 shows the physical properties of the obtained fiber.

[Dyeing process]
The dyeing process was implemented with respect to the obtained fiber according to Example 1 of Japanese Patent Publication No.62-184127.

[Physical properties of dyed fibers]
The dyeing rate was 92.9%, and the L * value was 24.7, indicating good dyeability. However, the 300 ° C. dry heat shrinkage ratio before and after dyeing was 2.67, indicating that the heat shrinkage rate change was large. Furthermore, the limiting oxygen index (LOI value) was 27.0, which was inferior in flame retardancy.

Claims (4)

  Easy-dyeing meta-type total fragrance in which the breaking strength of the fibril is 2.5 cN / dtex or more, the ratio of the dry heat shrinkage at 300 ° C. before and after dyeing is 2.5 or less, and the lightness index L * value of the dyed fiber is 25 or less Group polyamide fiber.   The easily dyeable meta-type wholly aromatic polyamide fiber according to claim 1, wherein the raw fiber has a dry heat shrinkage of 300 ° C of 3.0% or less.   The easily dyeable meta type wholly aromatic polyamide fiber according to claim 1 or 2, wherein the dyeing rate of the dyed fiber is 90% or more.   The easily dyeable meta-type wholly aromatic polyamide fiber according to any one of claims 1 to 3, wherein the limit oxygen index (LOI) of the dyed fiber is 30 or more.