JPH01139808A - Aromatic polyamide fiber with high configuration stability at high temperatures - Google Patents

Abstract

PURPOSE:To provide the title fiber of low heat shrinkage even at temperatures higher than the melting point, free from fiber fusing when burned, to be used for fireman uniforms etc., having functional group or halogen atom at the ortho site of the phenylene group directly bonded to the e.g., nitrogen atom in the amide group in an aromatic polyamide. CONSTITUTION:An aromatic dicarboxylic acid compound such as terephthalic acid is allowed to react, in a solvent, with 4-chloro-1,3-phenylenediisocyanate, while heating, to carry out a polymerization followed by vacuum filtration of the resulting polymer solution to prepare a spinning stock solution. Thence, this solution is delivered through a spinneret followed by coagulation in a coagulating bath, and the resultant yarn is subjected to dry heat drawing, thus obtaining the objective fiber having halogen atom or such functional group as amino, hydroxyl, sulfonic acid or carboxyl group at the ortho site of the phenylene group directly bonded to the nitrogen and/or carbon atom(s) in the amide group in the aromatic polyamide. This fiber has the following characteristics: 1. melting point TM>=350 deg.C, 2. TM-TEX>=30 deg.C(TEX refers to exothermic phenomenon initiation temperature), 3. degree of crystallinity XC>=10%, 4: fiber breaking elongation DE>=10%, 5. dry heat shrinkage rate DSR(TM)<=15%, 6. DSR(TM+55 deg.C)/ DSR(TM)<=3.

Description

Detailed Description of the Invention (Field of Application of the Invention) The present invention has the same general fiber performance as existing organic synthetic fibers, low heat shrinkage even at high temperatures above the melting point, and strong fiber bonding properties during combustion. This invention relates to a highly aromatic polyamide fiber that has excellent high-temperature morphological stability without fusion.

(Conventional technology) Organic synthetic fibers have excellent properties and are widely used in everything from clothing to industrial materials. Mainly inorganic fibers were used, and their use was extremely limited.

However, in recent years, progress in organic synthetic chemistry has been coupled with diverse needs ranging from general clothing and industrial materials to aerospace development, and the development of organic synthetic heat-resistant fibers has been progressing steadily. As a result, various organic synthetic heat-resistant fibers have been created. Among these, the one that has been most successful on a commercial scale and is considered to be the most representative is the meta-based wholly aromatic polyamide fiber, whose chemical composition is mainly composed of polymetaphenylene iso-7-talamide (hereinafter abbreviated as PMIA). .

This PMIA fiber has a temperature higher than that of existing synthetic fibers.
It can be used in a temperature range as high as 0 to 200°C, and has the general performance required as a general-purpose textile product, such as a balance between strength and elongation, flexibility, and post-processability. In addition, it has high flame retardancy, meaning it does not produce much flame even when the fiber burns, and extinguishes immediately when the flame is moved away. It is widely used in the materials field, clothing fields such as firefighting suits, aviation suits, alicyclic heat-resistant protective clothing in front of furnaces, and even in the bedding interior field, and continues to expand to this day.

However, it has been found that this PMIA fiber is not sufficient to meet the requirements for morphological stability at higher temperatures, for example, above the melting point, in clothing applications, such as materials for heat-resistant protective clothing. It has been proposed to mix a small amount of polyamide fiber (Tata Seiji; Plastic 36, 34 (1985)). According to this method, the shape stability at high temperatures is improved depending on the blending ratio, but due to the extremely high rigidity of para-based wholly aromatic polyamide fibers and the extremely low elongation for clothing fibers, ,
PMIA fibers have the disadvantage that they are as flexible as ordinary clothing fibers and that their post-processability is significantly reduced.

Although PMIA fibers do not melt during combustion and do not cause melt drips, the fiber products undergo large changes in shape due to heat shrinkage, and the fibers also become tightly fused together. In such cases, it becomes difficult to take off clothes, causing problems such as increasing the risk of burns and other injuries.

(Problems to be Solved by the Invention) The present inventors solved the problems of the PMIA fibers, namely, that the thermal shrinkage rate is small even at high temperatures above the melting point, and the fibers are firmly fused together during combustion. In order to obtain a unique aromatic polyamide fiber, we have conducted various studies from the aspects of polymer synthesis, fiber production, and fiber properties, and have finally arrived at the present invention.

(Means for solving the problem) That is, the present invention solves the problem by
A fiber manufactured from an aromatic polyamide having a functional group selected from an amino group, a hydroxyl group, a sulfonic acid group, a carboxyl group, or a halogen atom at the ortho position of a phenylene group directly connected to a nitrogen atom and/or a carbon atom, and TM≧350 ℃
, TM-TEX≧30℃, Xc≧10%, DE≧10%
, DSR(TM)≦15%, DSR(TM+55℃)/
The present invention relates to an aromatic polyamide fiber characterized in that DSR(TM)≦3.

The characteristic values and physical property values referred to in the present invention represent estimated values obtained using the measuring equipment and measurement conditions described below.

TM: melting point; put a sample of about 10119 in an AtH sample dish using DSC-20 manufactured by PerkinElmer and obtain a DSC curve from room temperature to a specified temperature in a nitrogen gas flow (30 d/min) at 10°C per minute. TM the endothermic peak temperature
shall be.

TEX: Heat generation start temperature; DS manufactured by PerkinElmer
Approximately 10 cm of a sample was placed in an At sample dish using C-20, and a DSC curve was obtained from room temperature to a predetermined temperature at 10°C per minute in an air stream (30 d/min), and the temperature at which the exotherm started was defined as TEX.

XC: Crystallinity; Rotating anticathode ultra-high intensity X-ray generator RAD-rA (40KV 100mA, manufactured by Rigaku Denki ■).

Using a diffraction angle of 2θ = 5° to 35° while rotating the sample in a plane perpendicular to the X-ray beam.
Obtain the line diffraction intensity curve, then convert the diffraction curve to the crystalline region (Ac
) and amorphous region (Aa ), calculated from the following formula, and the ratio value X
Let c be the crystallinity.

Ac Pull speed 5 cm 7 minutes, initial load 0.05
It was determined by conducting a tensile test under f/d conditions.

DSR (TM): Dry heat shrinkage rate DSR (T
M+55°C): represents the dry heat shrinkage rate at melting point + ss°C, and DSH was determined as follows.

After measuring the sample length to with a load of 0.1 t/d,
The sample length t1 was measured by applying a load of 0.11/d again after 30 minutes. In the invention, TM7 350℃, TM-TEX≧3
Must be 0℃, Xc≧10%, DE≧10chi. That is, in the aromatic polyamide fiber of the present invention, the TM (melting point) is 350°C or higher, and the T
It was discovered that when EX (exothermic onset temperature) is 30° C. or lower (Xc (crystallinity) is 10° C. or higher, it becomes a fiber with excellent shape stability even at high temperatures above the melting point).

In other words, even when TM≧350℃ and Xc≧101, TM-TEX is 30℃ or more and TM
- When comparing fibers with a TEX of less than 30°C, the former, that is, the TEX (thermal decomposition onset temperature) is 30° lower than the TM (melting point).
The shape stability at high temperatures above the TM (melting point) of the fiber is better when the temperature is lower than the latter, that is, when the TEX is less than 30°C than the glaze. This may seem absurd, but surprisingly, in reality, TEX
The lower the value, the better the shape stability.

I don't know the exact reason for this, but TM≧3
In the fiber of the present invention where Xc≧10% at 50°C and TEx is 30°C or more lower than TM, thermal decomposition starts from a relatively low TEx, so it occurs rapidly and mainly in the amorphous region. In order to ensure that microcrystals exist without melting in the crystalline region, microcrystals act as restraining points for the molecular chains against thermal contraction that occurs as the orientation of the oriented molecular chains in the amorphous region is relaxed due to heat. At the same time, a type of cross-linking occurs between molecular chains due to the thermal decomposition reaction that proceeds simultaneously.
It is thought that the morphological stability will be good even above the melting point at which a three-dimensional structure is formed.

On the other hand, even if TM≧350℃ and XC≧10%, if TEX is lower than TM by only less than 30℃, thermal melting occurs before a three-dimensional structure is formed due to sufficient intermolecular crosslinking. Therefore, it is thought that heat shrinkage and fusion between fibers increased, resulting in poor shape stability.

The range of this second -TEX must be TM-Tp:x≧30°C, preferably TM-TEX≧50°C, more preferably TM-TEX≧70°C.

Although the fibers of the present invention have good morphological stability even at high temperatures above the TM (melting point), other fiber properties deteriorate to some extent at temperatures above the TM (melting point).
In order to be a heat-resistant fiber that can be used at temperatures as high as 0°C or higher, TM must be 350°C and preferably T.
M≧400℃ or above, 0maku, 聰≧350℃, TM-
Even if TEX≧30℃, if the crystallinity is as low as XC (10%), the microcrystals will have almost no restraining effect on molecular chain movement, so thermal contraction will occur rapidly from the glass transition point, which is much lower than the phase. As the morphological stability increases, the morphological stability becomes poor.

For these reasons, it is necessary that Xc≧10%,
Preferably, Xc≧10.

Furthermore, in order for the fiber to be used in the same way as existing organic base fibers in applications such as clothing and industrial materials, good flexibility and processability are essential conditions. For this ninth point, it is important to have a sufficient balance between strength and elongation, especially elongation, and DE (fiber elongation) must be 10 inches or more. Preferably DE ) 1φ%, more preferably DE ) 2o%.

Next, a preferred embodiment for further enhancing the shape stability of the fibers of the present invention at high temperatures is DSR (TM).

If the DSR(TM) exceeds 15 inches, the dry heat shrinkage is already large at the melting point, and the shape stability cannot be said to be good. Even if DSR(TM)≦15, heat shrinkage increases rapidly, so if, for example, heat-resistant protective clothing is damaged while being worn, it may become difficult to remove it the next time, causing more damage such as burns. However, it is important that the thermal shrinkage is sufficiently small even at temperatures much higher than the melting point of +55°C.

The aromatic polyamide of the present invention has a nitrogen atom of an amide group and/or
Or, a phenylene group directly connected to a carbon atom is substituted with a functional group selected from an amino group, a hydroxyl group, a sulfonic acid group, a carboxyl group, or a halogen atom at the ortho position, and when it is substituted at a position other than the ortho position. Fibers with satisfactory shape stability at high temperatures cannot be obtained. Furthermore, as will be described later, the fibers of the present invention have dyeability at a practical level, which is thought to be due to the favorable effects of these substituents, such as increased affinity for solvents and increased dyeing rate.

An aromatic polyamide having a specific structure that satisfies the present invention can be easily produced by a known production method. That is, aromatic diamines and aromatic dicarboxylic acid halides can be produced by low-temperature solution polymerization, low-temperature interfacial polymerization, and the like. It can also be produced by high temperature solution polymerization from aromatic diisocyanate and aromatic dicarboxylic acid.

Raw materials for producing the aromatic polyamide of the present invention include aromatic diamines such as 1,3-phenylenediamine, 2-chloro-1,3-phenylenediamine, 4-chloro-1,3-phenylenediamine, 2. 5-dichloro-1,3-phenylenediamine, 4,6-cyclo-1,3-7 2-dichlorodiamine, 4-carboxy-1,3
-phenylenediamine, 4-sul7oh 1,3-phenylenediamisi% 1,4-phenylenediamine, 2-chloro-1,4-phenylenediamine, 2,5-dichloro-
1,4-phenylenediamine, 2,6-cycloru1.
4-4 phenylenediamine, 2-carboxy-1,4
Examples include -7 22-diamine, 2-sulfur 1.4-7 22-22 diamine, and mixtures thereof. Examples of the aromatic dicarboxylic acid civalide to be reacted with the diamine include isophthalic acid dichloride, 2-
Amino-isophthalic acid dichloride, 4-amino-isophthalic acid dichloride, 4-promoisophthalic acid dibromide, 4-chloro-isophthalic acid dichloride, 4
．． 6-dichloro-inphthalic acid cyclolide, 4-hydroxy-isophthalic acid dichloride, terephthalic acid dichloride, 2-amino-terephthalic acid dichloride, 4
Examples include -bromo-terethalic acid dipromide, 2,5-hydroxy-terephthalic acid dichloride, and mixtures thereof.

Further, as aromatic diisocyanate, for example, 1°2-7
22 diisocyanate, 2-chloro-1,3-phenylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 2,4-dichloro-1,3-phenylene diisocyanate, 4゜6-dichloro- 1,3
-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2-chloro-1,4-7 di-2 diisocyanate), 2,5-cyclo-1,4-phenylene diisocyanate, 2,6-dichloro-1,4-phenylene Examples include diisocyanates and mixtures thereof.

Examples of the aromatic dicarboxylic acid reacted with the diisocyanate include isophthalic acid, 2-amino-isophthalic acid, 4-amino-ynepthalic acid, 4-promoinphthalic acid, 4-chloro-isophthalic acid, 4.6 -Cycloluin hepthalic acid, 4-hydroxy-isophthalic acid, 4
-Sulfoisophthalic acid, terephthalic acid, 2-amino-terephthalic acid, 2-promoterephthalic acid, 2.5-
Examples include dihydroxy-terephthalic acid, 2-sulfoterephthalic acid, and mixtures thereof. The aromatic polyamide of the present invention can be produced by combining these raw materials, and more preferably, the aromatic polyamide is produced by combining raw materials that satisfy the repeating unit represented by the following formula (I).

-HN-Art -NH-QC-Arz -Co-(1
) That is, in an aromatic polyamide having a repeating unit represented by formula (1), Arl and/or Ar2 are amino groups, hydroxyl groups, sulfonic acid groups,
It is a divalent phenylene residue because it has a functional group selected from carboxyl groups or a halogen atom, and Arl or Ar
z, are each composed of a combination of one or more types of raw materials, and the ratio of coaxial (para bond) to nonparallel axis (meta bond) of the bond axes of either Arr or Arz is 10.
010 to 80/20, it is preferable to take a combination of raw materials such that the ratio of the bond axes of the other component is O/100 to 20/80. This also means that the sum of the bond axes of Ar1 and Ar2 is means that the coaxial: sleeve parallel axis = 60:40 to 40:60 molar ratio, and when the number of coaxial bonds increases beyond this range, the fiber becomes rigid and has low elongation, resulting in desired physical properties. If the number of non-parallel axes increases, the general physical properties of the fiber will be good, but the dry heat shrinkage at high temperatures will be large and the shape stability will be poor.

The highly aromatic polyamide fiber having excellent high-temperature shape stability according to the present invention may be produced by any known method, but it is preferably produced by dry spinning or wet spinning.

An amide solvent such as dimethylformamide, dimethylacetamide, N-methyl-pyrrolidone, N,N'-dimethylethylene urea or dimethyl sulfoxide is used as the spinning stock solution, and the superpolymerization solution is used as it is.
Alternatively, it can be used after being concentrated.

In particular, in the case of the polyamide with a specific structure according to the present invention, the polymerization solution produced by the method separately invented by the present inventors and disclosed in Japanese Patent Application Laid-Open No. 1988-190517 is used as a spinning stock solution, for example, the stock solution temperature is 30°C. ~100°C, coagulation bath composition; C
aα23〇250 aqueous solution, coagulation bath temperature; 50-100
wet spinning under conditions of 1.1 to 5 times, followed by thorough washing in hot water at 50 to 100 degrees Celsius, followed by hot air drying at 100 to 200 degrees Celsius, Subsequently, the heat-resistant aromatic polyamide fiber of the present invention, which has excellent shape stability at high temperatures, is subjected to a dry heat stretching heat treatment of 1.1 to 5 times in air or an inert gas bath at 300°C to 450°C. can be manufactured.

(Effects and Applications of the Invention) The fibers of the present invention have almost the same strength and elongation as existing organic synthetic fibers, such as polyethylene terephthalate fibers.
It has general recoil performance, represented by Young's modulus, and properties not found in PMIA fibers, which are existing heat-resistant organic synthetic fibers.In other words, the thermal shrinkage is small even at high temperatures above the melting point, and the fibers stick together even when burned. It has excellent t-form stability without being strongly fused. Furthermore, regarding the poor dyeability, which is said to be one of the biggest drawbacks of KPMIA fibers, the fibers of the present invention are much better than PMIA fibers and are at a practical level. Therefore, it can be used for a wide range of purposes, from protective clothing to bedding to interior decoration, taking advantage of its heat resistance and high-temperature morphological stability.

Next, aspects of the present invention will be specifically explained with examples, but the present invention is not limited by these examples.

Example 1 Terephthalic acid 150.1F (0,9035 mol), terephthalic acid monopotassium salt 1,7009% m water Nt in a separable flask with fc3L capacity equipped with a stirrer, thermometer, condenser, dropping funnel, and nitrogen introduction tube. 1500 a/ml of merged methyl ethylene urea is charged under a nitrogen atmosphere and heated to 200° C. with stirring on an oil bath. While maintaining the contents at 200°C, 197.2 F (0,8127 mol) of 4-chloro-1,3-phenyl diisocyanate and 21.9 t of 2-chloro-1,3-phyl diisocyanate ( 0,0903 mol) in anhydrous N, N'-
Dimethylethylene urea was dissolved in 200 at, and the solution was added dropwise from the dropping funnel over a period of 2 hours. After continuing the reaction for an additional hour, heating was stopped and the mixture was cooled to room temperature. A portion of the reaction solution was taken and poured into strongly agitated water to precipitate a white polymer, which was further washed with a large amount of water and dried under reduced pressure at 150°C for about 3 hours. 1, 30°C) was 1.5. The polymer concentration of the polymerization solution was about 14.0% by weight, and the viscosity of this solution was 420 voids (B-type viscometer; 50° C.). The obtained t-polymer was found to be polyC(4-
Chlor-1,3-)unitine terephthalamide)m(2
-chloro-1,3-phenylene terephthal, amide) n
] (m:n-9:1).

The above polymerization solution was filtered under reduced pressure at 50° C. to prepare a spinning stock solution containing no air bubbles. Then, while keeping the temperature at 50℃, the pore size was adjusted to 0.1.
The temperature is maintained at 80℃ from a 1m nozzle with 600 holes (6 holes are circular) and 7'tCac! Discharge at 38.8 f/min into an aqueous coagulation bath containing 237%. The filamentous material discharged from the nozzle is passed through a coagulation bath, and then subjected to moist heat stretching at about 1.5 times in a bath with the same composition as the coagulation bath, and then thoroughly washed with water in a washing bath consisting of 80°C warm water. An oil agent is applied thereto, and the fiber is dried through a hot air tank at 150° C. to obtain a wet-heat-stretched spun yarn.

The spinning yarn has an oval cross section and is 2800 denier/600 filament. Next, this spun yarn was subjected to dry heat stretching at -370°C using a nitrogen flow hollow dry heat stretching machine at a stretching ratio of 2.3 times, thereby producing the poly[(4-chloroA) of the present invention. / -1,3-phenylene terephthalamide) m (2-10 1° 3-phenylene terephthalamide) n) (m:n = 9:1).

The physical properties of the obtained fiber were as follows: single yarn denier = 2, strength = 4.
st/drs elongation +25.4%, Young's modulus = 72f/d
%TM=380℃, TEX -290℃, TM-TE
X = 90°C, Xc -18%, DSR(TM
) -D S R (380°C) = 12%, which numerically indicates good general fiber physical properties and excellent shape stability at high temperatures above the melting point.

Next, a tubular knitted fabric was made using the fibers of the present invention, and a combustion test was conducted using this fabric.As a precaution, it clearly showed self-extinguishing properties that extinguished immediately when the flame was kept away, and when observed on silk fabric 1 after burning, combustion There was also no strong fusion of the fibers together.

Furthermore, a dyeing test was conducted on the fiber of the present invention. The dyeing conditions were disperse dye 5% O0W, F, dyeing temperature 140℃, dyeing time 60 minutes, and using a carrier.The four colors of food stamps tested, blue, purple, and yellow, were dyed sufficiently deep. Ta.

Example 2 Synthesis was carried out using the same equipment and method as in Example 1. 2-Amitoterephthalic acid 163.9F (0,9050 moN), terephthalic acid monopotassium salt 1,3114° anhydrous N, N'
-Dimethylethylene urea 1600- was charged into a separable flask, and while maintaining the contents at 200°C, 1.
3-7 22 diisocyanate) 144.9 f (
0,9050 mol) of anhydrous N,N'-dimethylethyleneurea 150! ! Dissolved in Ll and added the solution dropwise over 2 hours. Thereafter, the polymer obtained by processing in the same manner as in Example 1 had a logarithmic viscosity of 1.6. The polymer concentration of the specific polymerization solution was 14% by weight, and the viscosity of this solution was 480 poise.

Production of IJ (1,3-phenylene-2-amino-tere-7-talamide fiber) The same apparatus as in Example 1 except that the Ca pseudo concentration in the aqueous coagulation bath was 33% and the dry heat stretching temperature was 400°C. Aromatic polyamide fiber was produced by the method 9. The physical properties of the obtained fiber were as follows: single yarn denier = 2, strength = 5.1'/ds elongation U =
23% s Young's modulus -831/d.

Tyt = 415°C, TEX = 310°C, TM-TE
X-ios°C, Xc = 22%, DSR(TM) =
DSR(415℃)=11%, DSR(TM+5
5°C) = DSR (470°C) = 18%, indicating good fiber physical properties and excellent morphological stability at high temperatures above the melting point.

A dyeing test using a disperse dye was conducted in the same manner as in Example 1, and
All four colors, red, blue, purple, and yellow, were dyed sufficiently deep.

Comparative Example 1 Production of poly(metaphenylene isophthalamide) 250.2 F (1,232 mol) of isophthalic acid chloride and 600 d of anhydrous tetrahydrofuran were placed in a 2 t jacketed separable flask equipped with a stirrer, a thermometer, and a jacketed dropping funnel. Pour it in, melt it, and cool the contents to 20℃ by passing a refrigerant through the jacket. Metaphenylenediamine 133.7F (1,237 mol) was dissolved in 400 ml of anhydrous tetrahydrofuran with strong stirring, and the solution was added dropwise over about 20 minutes. The resulting white emulsion was quickly poured into water (water-cooled) containing 2.464 mol of anhydrous soda carbonate under strong stirring. The slurry temperature immediately rose to near room temperature. Subsequently, the slurry was adjusted to 11 with caustic soda, and the slurry was thoroughly washed with a large amount of water and dried overnight under reduced pressure at 150°C to obtain the fL7t polymer. The logarithmic viscosity of is 1.4.

Preparation of poly(metaphenyleneiso7talamide) fiber The poly(metaphenyleneiso7talamide) or PMIA polymer powder was mixed with N-methyl-2-pyrrolidone (
NMP) and NMP were dissolved at a concentration of 22% by weight in a solvent containing 2 parts of L1α, and filtered under reduced pressure at 80°C to prepare a spinning dope free of air bubbles. Discharged from a nozzle with a hole diameter of 0.08 and a number of holes of 100 (6 holes are circular) into an aqueous coagulation bath containing 240% Caα maintained at 80°C at 5.2F 1 minute via a roller rotating at 10 m/min. ℃ hot water bath, thoroughly rinsed with water, then subjected to wet heat stretching at 2.88 times with rollers in 98℃ hot water, and after applying an oil agent, dried by passing through a 150℃ hot air bath to complete wet heat stretching. Focus on spinning yarn. The spinning atoms have a homogeneous cocoon-shaped cross section, 3
It was 58 denier/100 filament.

Next, the spun atoms were subjected to dry heat stretching 1.88 times on a plate at 310°C to obtain poly(metaphenylene inctalamide) fibers.

The physical properties of the obtained fibers are: single yarn denier = 2, strength = 4
．． 9 t/d, elongation=28.54, Young's modulus=80f/
d% TM = 425℃, TEX = 40
5℃, TM2 TEX-20℃, XC=25%, DSR
(TM) = DSR (425°C) = 16%, and although the PMIA fibers outside the present invention exhibit good general fiber physical properties, the shape stability at high temperatures above the melting point is limited by the present invention. This was clearly inferior to Example 1 and Example 2.

Next, the above PMIA fiber fa? However, when observing the knitted fabric after combustion, it was found that the fibers were firmly attached to each other in the burning part, although it clearly showed self-extinguishing properties that extinguished immediately when the flame was moved away. It was fused and the fiber form had completely disappeared.

Next, replace the fiber sample with the PMIA fiber of this example and carry out the same dyeing test as in the example except for the following. PMI in this case
It can be seen that the A@l fibers were hardly dyed in any of the colors, and compared to Examples 1 and 2 of the present invention, the dyeability was significantly inferior.

Example 3 Polymerization of poly 14-phenylene-2-hydroxy-isophthalamide A ft-ft.
216.8 tons of 2-hydroxy-isophthalic acid chloride (0,990
0 mol), anhydrous sodium chloride 79 y800d was added and dissolved, and the contents were heated to 10°C by passing the refrigerant through the jacket.
It was cooled to Add 1 phenylene diamine while stirring vigorously.
07. A solution of iF (0,9907 mol) dissolved in 500 d of anhydrous tetrahydro7ran was added over about 10 minutes. The resulting bright white suspension was poured into water containing 2.0 mol of anhydrous sodium carbonate under water cooling. The slurry temperature immediately rises to near room temperature. Subsequently, with caustic soda, l:4 (1
1, the slurry was separated in a furnace, washed repeatedly with a large amount of water, and then dried overnight at 150° C. under reduced pressure to obtain a white polymer. The logarithmic viscosity of the polymer is 1.3, and the poly(1,4-]dinilene-2-hydroxy-isophthalamide) is dissolved in N-methyl-pyrrolidone.
Approximately 15% by weight of the solution. The spinning dope was vacuum-filtered at 80°C to obtain a bubble-free spinning stock solution, and then passed through a nozzle with a pore size of 0.08 mm and 100 holes kept at 80°C in an aqueous coagulation bath containing CacJ232. to 5.2t/
After discharging for 10 minutes, it was further subjected to wet heat stretching 1.5 times in a bath with the same composition as the coagulation bath, and then thoroughly washed in a washing bath consisting of 80℃ hot water, and after applying an oil agent, it was passed through a hot air bath at 150℃. After drying, wet heat drawn yarn is obtained.

This yarn is made of 540 denier/100 filament. Next, this yarn was kept at 430°C and subjected to dry heat stretching at 2.7 times using a nitrogen stream hollow dry heat stretching machine.
, 4-phenylene-2-hydroxy-inphthalamide) fibers. The physical properties of the obtained fiber are single yarn denier =
2. Strength = 5.3 f/ds elongation = 191. −? /
Grading rate=98f/d, TM=420℃, TEX=320℃
, TM-TEX = -100℃, Xc 23%, DS
R(TM)=DSR(420°C); 9%, DSR(TM
+55℃) = DSR (475℃); 16, and this fiber made of nine aromatic polyamide with a hydroxyl group substituted at the ortho position of the isophthalic acid bond axis has excellent general physical properties and good morphological stability at high temperatures. It shows that it has.

Comparative Example 2 Example 3 except that 5-hydroxyisophthalic chloride was used instead of 2-hydroxy-isophthalic acid chloride.
Polymerization was carried out in the same manner using the same equipment. The logarithmic viscosity of the nine polymers obtained was 1.50.About 15% of the above polymer was prepared in the same manner as in Example 3.
-Methyl-pyrrolid/480 denier/100 from solution
Obtain a wet-heat-drawn yarn of filament, and then process this yarn into 4
2.4 using a nitrogen flow hollow dry heat stretching machine maintained at 10°C.
The IJ (1,4-phenylene-5
-Hydroxyisophthalamide) fiber was obtained. Single yarn denier of the obtained fiber = 2.0, strength 4.9 f/d,
Elongation 30%, Young's modulus = 959/d, TM = 425
℃, TEX=340℃, TM-TEX=85℃, Xc
-17%, DSR(TM)=DSR(425℃)=22
*% DSR (TM + 55°C) - In the case of DSR amide, the resulting fiber shows good general physical properties, but has large dry heat shrinkage at high temperatures and is a fiber with poor shape stability.

Patent applicant RiRashi Co., Ltd. Same Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] (1) An aromatic polyamide having a functional group selected from an amino group, a hydroxyl group, a sulfonic acid group, a carboxyl group, or a halogen atom at the ortho position of the phenylene group directly connected to the nitrogen atom and/or carbon atom of the amide group of the aromatic polyamide. T_M≧350℃, T_M-T_
E_X≧30℃, X_C≧10%, D_E≧10%, D
SR(T_M)≦15%, DSR(T_M+55℃)/
An aromatic polyamide fiber characterized in that DSR (T_M)≦3.