JP2017008423A - Co-polyparaphenylene 3,4'-oxydiphenylene terephthalamide stretched fiber and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a co-polyparaphenylene 3,4'-oxydiphenylene terephthalamide stretched fiber excellent in a tensile elastic modulus even if the number of single yarns is high, and a method for producing the same.SOLUTION: High tensile strength hot drawing is performed to a co-polyparaphenylene 3,4'-oxydiphenylene terephthalamide fiber in such a manner that the width of a fiber bundle lies in a specified range.SELECTED DRAWING: None

Description

  The present invention relates to a drawn fiber of copolyparaphenylene 3,4'-oxydiphenylene terephthalamide. More specifically, the present invention relates to a copolyparaphenylene • 3,4′-oxydiphenylene • terephthalamide drawn fiber having a high tensile elastic modulus and a method for producing the same.

Conventionally, para-type wholly aromatic copolyamide fibers mainly composed of an aromatic dicarboxylic acid component and an aromatic diamine component have characteristics of high strength and high tensile elastic modulus. It is used for various industrial materials such as ropes.
Such para-type wholly aromatic copolyamide fibers are generally produced by a so-called “wet spinning method” or “semi-dry semi-wet spinning method”. That is, an optically isotropic spinning solution is extruded through a die and brought into contact with the coagulation liquid in the coagulation bath, either after passing through air or inert gas, or directly without passing through it, and thereafter The final fiber is obtained through steps such as washing with water, drying and stretching (see Patent Document 1).

Until now, various studies have been made to obtain a copolyparaphenylene • 3,4′-oxydiphenylene • terephthalamide fiber having a high tensile elastic modulus. For example, a method has been reported in which para-type wholly aromatic copolyamide fibers produced by a “wet spinning method” or “semi-dry semi-wet spinning method” are subjected to tension heat treatment under specific conditions (see Patent Documents 2 to 4). .
However, in the case of a fiber bundle having a large number of single yarns, when the tension heat treatment is performed, the fiber bundle converges and heating becomes non-uniform, and as a result, the tensile elastic modulus of the fiber bundle cannot be improved so much. At the present time, a sufficiently satisfactory tensile elastic modulus has not yet been realized.

JP-A-60-110918 JP-A-7-166417 JP-A-8-296116 JP-A-8-311715

  The present invention has been made against the background of such prior art, and the object thereof is a para-type wholly aromatic copolyamide drawn fiber having excellent tensile elastic modulus even when the number of single yarns is large, and production thereof. It is to provide a method.

The present inventor has intensively studied to solve the above problems. Then, the present inventors have found that the above-mentioned problems can be solved by subjecting the copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide fiber to high-strength hot drawing with the fiber bundle width as a specific range, and completed the present invention. It came to do.
That is, the present invention is a copolyparaphenylene · 3,4′-oxydiphenylene · terephthalamide drawn fiber having a tensile elastic modulus of 665 cN / dtex or more.

  Hereinafter, embodiments of the present invention will be described in detail.

<Physical properties of copolyparaphenylene 3,4'-oxydiphenylene terephthalamide drawn fiber>
[Tensile modulus]
The copolyparaphenylene-3,4′-oxydiphenylene-terephthalamide drawn fiber of the present invention is a fiber having a tensile elastic modulus of 665 cN / dtex or more. The tensile modulus is preferably 675 cN / dtex or more, and most preferably 685 cN / dtex or more.

[Tensile strength]
The higher the tensile strength of the copolyparaphenylene • 3,4′-oxydiphenylene • terephthalamide drawn fiber of the present invention, the better. Preferably it is 25.5 cN / dtex or more, More preferably, it is 26.0 cN / dtex or more.

[Number of single yarns]
The copolyparaphenylene-3,4′-oxydiphenylene-terephthalamide drawn fiber of the present invention is preferably a fiber having a single yarn number of 500 filaments or more. Even when the number of single yarns is large, a high tensile elastic modulus is a feature of the present invention. The number of single yarns is more preferably 1000 filaments or more, and most preferably 2000 filaments or more.

[Single yarn fineness]
The copolyparaphenylene-3,4′-oxydiphenylene-terephthalamide drawn fiber of the present invention has a single yarn fineness of 0.8 to 6.0 dtex. The single yarn fineness is preferably 1.0 to 5.0 dtex, and most preferably 1.1 to 4.0 dtex.

<Copolyparaphenylene 3,4'-oxydiphenylene terephthalamide fibrils>
The copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide fibrils used as the fibrils of the copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide drawn fiber of the present invention are copolyparaphenylene-3, 4'-oxydiphenylene terephthalamide is the main component. The copolyparaphenylene-3,4′-oxydiphenylene terephthalamide contained in the fiber is preferably 60% by mass or more, more preferably 80% by mass or more, based on the entire fiber mass. Most preferably, it is 100%.

<Method for producing copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide>
The copolyparaphenylene 3,4′-oxydiphenylene terephthalamide used as the fiber material of the present invention can be produced by a conventionally known method. For example, by reacting an aromatic dicarboxylic acid chloride component and an aromatic diamine component in an amide polar solvent, a polymer solution of copolyparaphenylene 3,4′-oxydiphenylene terephthalamide can be obtained. it can.

[material]
(Aromatic dicarboxylic acid dichloride component)
Terephthalic acid dichloride is used as the aromatic dicarboxylic acid chloride component which is a raw material of copolyparaphenylene 3,4′-oxydiphenylene terephthalamide. In the present invention, a substituent may be present on the aromatic ring. A small amount of a dicarboxylic acid dichloride component other than terephthalic acid dichloride may be used in combination with terephthalic acid dichloride.

(Aromatic diamine component)
As an aromatic diamine component used as a raw material for copolyparaphenylene 3,4′-oxydiphenylene terephthalamide, paraphenylenediamine and 3,4′-diaminodiphenyl ether are used in combination. In the present invention, a substituent may be present on the aromatic ring. Moreover, you may use together a small amount of diamine components other than paraphenylenediamine and 3,4'- diamino diphenyl ether with these.

[Raw material composition ratio]
The ratio of the aromatic dicarboxylic acid chloride component to the aromatic diamine component is preferably in the range of 0.90 to 1.10 as the molar ratio of the aromatic dicarboxylic acid chloride component to the aromatic diamine component, 0.95 More preferably, it is in the range of ˜1.05. When the molar ratio of the aromatic dicarboxylic acid chloride component is less than 0.90 or exceeds 1.10, the reaction with the aromatic diamine component does not proceed sufficiently and a high degree of polymerization cannot be obtained, which is not preferable.

[Reaction conditions]
The reaction conditions for the aromatic dicarboxylic acid chloride component and the aromatic diamine component are not particularly limited. The reaction between acid chloride and diamine is generally rapid, and the reaction temperature is preferably, for example, in the range of -25 ° C to 100 ° C, more preferably in the range of -10 ° C to 80 ° C.

[Polymerization solvent]
Examples of amide solvents used for the production of copolyparaphenylene-3,4′-oxydiphenylene-terephthalamide include N-methyl-2-pyrrolidone (hereinafter also referred to as NMP), N, N-dimethylformamide, N , N-dimethylacetamide, dimethylimidazolidinone and the like. These solvents can be used alone or as a mixed solvent of two or more. Note that the solvent used is preferably dehydrated.
In the production of the copolyparaphenylene-3,4'-oxydiphenylene terephthalamide used in the present invention, versatility, harmfulness, handling property, copolyparaphenylene-3,4'-oxydiphenylene terephthalamide From the viewpoint of solubility and the like, it is most preferable to use N-methyl-2-pyrrolidone (NMP).

[Neutralization reaction]
After completion of the reaction, it is preferable to carry out a neutralization reaction by adding a basic inorganic compound such as sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium oxide or the like, if necessary.

[Post-polymerization, etc.]
The copolyparaphenylene 3,4′-oxydiphenylene terephthalamide obtained by polymerization can be put into a non-solvent such as alcohol or water, precipitated, and taken out in the form of pulp. The extracted copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide can be dissolved again in another solvent and then used for fiber molding, but the polymer solution obtained by the polymerization reaction is used as it is. It is also possible to prepare and use in a spinning solution (dope).
The solvent used for once taking out and then dissolving again is not particularly limited as long as it dissolves copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide, but the above-mentioned copolyparaphenylene is not limited. -It is preferable to use it as a solvent used for the polymerization of 3,4'-oxydiphenylene terephthalamide.

<Method for producing copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide fibrils>
As a method for obtaining the copolyparaphenylene 3,4′-oxydiphenylene terephthalamide fibril used as the fibril of the drawn copolyparaphenylene 3,4′-oxydiphenylene terephthalamide of the present invention, a known method is known. For example, a semi-dry semi-wet spinning method as described below can be adopted.

[Process for preparing spinning solution (dope)]
In obtaining the fibril, first, a spinning solution (dope) containing copolyparaphenylene 3,4′-oxydiphenylene terephthalamide and a solvent is prepared. The method for preparing the spinning solution (dope) is not particularly limited, and can be prepared by a known method.
Here, the solvent used for the preparation of the spinning solution (dope) is a solvent used for the polymerization of the above-described copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide, and copolyparaphenylene-3, A solvent capable of dissolving or dispersing 4′-oxydiphenylene terephthalamide and other optional components is preferable. In addition, the solvent used may be a single solvent or a mixed solvent obtained by mixing two or more solvents.
It is also possible to use the polymer as it is as a spinning solution (dope) without isolating the polymer from the polymer solution obtained by the production of copolyparaphenylene 3,4′-oxydiphenylene terephthalamide.

Furthermore, for the purpose of imparting functionality and the like to the fiber, other optional components such as additives may be blended within a range not exceeding the gist of the present invention. When an optional component is blended, it can be introduced in the preparation of a spinning solution (dope). Examples of other optional components include inorganic salts, fillers such as fibers or powders, antioxidants, weathering agents, dyes, antistatic agents, flame retardants, conductive polymers, and other polymers. . The method of introduction is not particularly limited, and for example, it can be introduced using a ruder or a mixer.
The polymer concentration in the spinning solution (dope), that is, the concentration of copolyparaphenylene 3,4′-oxydiphenylene terephthalamide is preferably in the range of 0.5% by mass to 30% by mass, and 1% by mass. More preferably, it is in the range of ˜25 mass%. When the polymer concentration in the spinning solution (dope) is less than 0.5% by mass, the viscosity necessary for spinning cannot be obtained because the polymer is less entangled. On the other hand, when the polymer concentration exceeds 30% by mass, an unstable flow tends to occur when discharging from the discharge hole of the die, and it becomes difficult to perform stable spinning.

[Spinning and coagulation process]
In the production of the copolyparaphenylene 3,4'-oxydiphenylene terephthalamide fibrils used as the fibrils of the drawn copolyparaphenylene 3,4'-oxydiphenylene terephthalamide fibers of the present invention, as described above, It is preferable to form a fiber by the semi-dry semi-wet spinning method provided with an air gap using the prepared spinning solution (dope). That is, first, the spinning solution (dope) obtained as described above is discharged from a nozzle and subsequently brought into contact with a coagulating liquid in a coagulating bath to form a coagulated yarn in a plasticized state.
As the coagulation bath, a poor solvent such as copolyparaphenylene 3,4′-oxydiphenylene terephthalamide is used, but the solvent of the spinning solution (polymer dope) quickly escapes and the resulting coagulated yarn has defects. Usually, a good solvent is added to adjust the coagulation rate so that it cannot. It is preferable to use water as the poor solvent and a solvent for copolyparaphenylene 3,4′-oxydiphenylene terephthalamide as the good solvent. The mass ratio of good solvent / poor solvent is preferably in the range of 15/85 to 40/60, although it depends on the solubility and coagulability of copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide. .

[Washing process]
Next, the coagulated yarn obtained in the spinning / coagulation step is washed with water. The purpose of the water washing step is to diffuse NMP in the yarn using water and remove it from the yarn. If NMP can be sufficiently removed from the yarn, washing conditions such as temperature and washing time are not particularly limited.

[Drying process]
Next, the washed yarn is dried. The drying conditions are not particularly limited, and there is no problem as long as moisture attached to the fibers can be sufficiently removed. However, in consideration of workability and deterioration of the fibers due to heat, the temperature is in the range of 150 to 250 ° C. It is preferable. Moreover, drying can use any of contact-type drying apparatuses, such as a roller, and non-contact-type drying apparatuses, such as passing a fiber through a drying furnace.

[Hot drawing process]
Next, the dried fiber is hot-drawn. The purpose of this step is to improve the physical properties by applying heat to the fibers to densify the molecular structure and by promoting the molecular orientation by stretching. The heat stretching temperature at this time is preferably in the range of 300 to 600 ° C, more preferably 320 ° C to 580 ° C, and most preferably 350 to 550 ° C. When the heat drawing temperature is less than 300 ° C., the yarn cannot be sufficiently drawn, which is not preferable. On the other hand, when the temperature exceeds 600 ° C., thermal degradation of the polymer occurs, so that the fiber deteriorates and the mechanical properties are remarkably lowered.
The draw ratio in the hot drawing step is preferably 5 to 15 times, but is not particularly limited to this range. Further, this hot stretching process may be performed in multiple stages as required, and there is no problem.

[Winding process]
Next, it winds up with a winder. At this time, it is possible to apply an oil agent for the purpose of imparting charge suppression, lubricity, etc. to the fiber, if necessary, immediately before winding it on the winder. In that case, the type and amount of the oil agent to be applied Etc. are not particularly limited, and known methods can be applied as they are. In addition, the winding method and winding conditions in the winder are not particularly limited, and the winding can be performed by appropriately adjusting the conditions using a known winder.

<Manufacture of copolyparaphenylene 3,4'-oxydiphenylene terephthalamide drawn fiber>
[High-tensile heat drawing process]
In order to obtain the copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide drawn fiber of the present invention, the copolyparaphenylene-3,4'-oxydi which is the fibril obtained by the above method is used. High-strength hot-drawing is applied to the phenylene terephthalamide fibrils with the width of the fiber bundle as a specific range.
The purpose of this high-tensile thermal stretching step is to further promote molecular orientation and improve physical properties by performing thermal stretching under high tension. In the present invention, the apparatus and conditions are not particularly limited as long as the width of the fiber bundle can be sufficiently opened within a specific range.
In addition, even if it implements the high tension | tensile_strength hot drawing process based on this invention continuously after the heat drawing process for manufacturing said fibril, it does not interfere.

(Width of fiber bundle)
In the high-tensile hot drawing step, high-strength hot drawing is performed on the copolyparaphenylene-3,4′-oxydiphenylene-terephthalamide fibril so that the width of the fiber bundle satisfies the following formula (1). It is essential.
Fiber bundle width (mm) ≥ Single yarn diameter (mm) x Number of single yarns (pieces) / 3 (1)
The width of the fiber bundle preferably satisfies the formula (2), and most preferably satisfies the formula (3).
Width of fiber bundle (mm) ≥ Single yarn diameter (mm) x Number of single yarns (pieces) / 2 (2)
Width of fiber bundle (mm) ≧ diameter of single yarn (mm) × number of single yarn (number) / 1 (3)

(temperature)
The temperature in the high-tensile hot drawing step is preferably 50 to 450 ° C, more preferably 100 to 425 ° C, and most preferably 150 to 400 ° C. When the temperature is less than 50 ° C., only elastic deformation occurs even when tension is applied, and when the tension is removed, the shape immediately returns to the state before stretching, and thus does not contribute to improvement of the tensile elastic modulus. On the other hand, when it exceeds 450 ° C., not only thermal decomposition of copolyparaphenylene 3,4′-oxydiphenylene terephthalamide occurs, but it becomes a pseudo thermoplastic state and high tension is applied during stretching. As a result, the mechanical properties are not improved, which is undesirable.

(tension)
The tension in the high tension hot stretching step is preferably in the range of 30 to 60N, more preferably in the range of 35 to 55N, and most preferably in the range of 40 to 50N. When the tension is less than 30N, the formation of molecular orientation is small and the improvement in tensile modulus is small. On the other hand, when it exceeds 60N, not only the single yarn in the fiber breaks and the quality is lowered, but also the number of effective single yarns contributing to the tensile breaking rate in the fiber decreases, and the tensile modulus of elasticity. Is undesirable because

(Stretch ratio)
The draw ratio in the high-tensile hot drawing step is preferably 1.01 to 1.20 times, but is not particularly limited to this range. Further, this hot stretching process may be performed in multiple stages as required, and there is no problem.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, this invention is not limited to these, unless the summary is exceeded.

<Measurement and evaluation method>
In Examples and Comparative Examples, the following items were measured and evaluated by the following methods.

(1) Fiber fineness The obtained fiber bundle was wound up by 100 m using a known measuring instrument, and its mass was measured. A value obtained by multiplying the obtained mass by 100, that is, a mass per 10,000 m was calculated as a fineness (dtex).

(2) Tensile modulus and tensile strength of fiber Using a tensile tester (manufactured by INSTRON, trade name: INSTRON, model: 5565 type), using a yarn test chuck, based on the procedure of ASTM D885, under the following conditions: Measurements were performed.
[Measurement condition]
Temperature: Room temperature Test piece: 75cm
Twist factor: 1
Test speed: 250 mm / min Chuck distance: 500 mm

<Example 1>
[Manufacture of copolyparaphenylene 3,4'-oxydiphenylene terephthalamide fibrils]
As a spinning solution (polymer dope), a concentration of 6% by mass of N-methylpyrrolidone (NMP) of copolyparaphenylene, 3,4′-oxydiphenylene, terephthalamide (fully aromatic polyamide having a copolymerization molar ratio of 1: 1) was used. ) A solution was prepared.
The spinning solution (polymer dope) was heated to 105 ° C., and the solution was sent to a spinning pack heated to 105 ° C. with a spinneret having a hole diameter of 0.3 mm and a hole number of 1000, and through a 10 mm air gap, The solution was passed through a coagulation bath filled with a 50 ° C. aqueous solution having an NMP concentration of 30% by mass to obtain a coagulated fiber bundle in which the polymer coagulated (wet method).
Next, the coagulated fiber bundle was passed through a water washing bath adjusted to 55 ° C. and washed with water, and then dried with a 200 ° C. drying roller.
Next, after drying the fiber bundle, first-stage heat stretching was performed at 380 ° C. The draw ratio at this time was 2.4 times. Subsequently, second-stage heat stretching was performed at 530 ° C. The draw ratio at this time was 4.0 times. Furthermore, the third stage of thermal stretching was performed at 400 ° C. The draw ratio at this time was 1.02.
Table 1 shows the fineness, the number of filaments, and the single yarn diameter of the obtained copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide fibrils.

[Production of Copolyparaphenylene 3,4'-oxydiphenylene terephthalamide drawn fiber]
Subsequently, the obtained copolyparaphenylene-3,4′-oxydiphenylene-terephthalamide fibril was subjected to high-tensile hot drawing using a non-contact heat treatment furnace. At this time, the tension was 50 N, the temperature was 300 ° C., and the draw ratio was 1.04. The width of the fiber bundle in the high tension hot drawing process was 12 mm. Table 1 shows the physical properties of the obtained copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide drawn fiber.

<Example 2>
A copolyparaphenylene-3,4′-oxydiphenylene-terephthalamide drawn fiber was produced in the same manner as in Example 1 except that the width of the fiber bundle in the high tension hot drawing process was 8 mm. Table 1 shows the physical properties of the obtained copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide drawn fiber.

<Example 3>
A copolyparaphenylene-3,4′-oxydiphenylene-terephthalamide drawn fiber was produced in the same manner as in Example 1 except that the width of the fiber bundle in the high tension hot drawing process was changed to 4 mm. Table 1 shows the physical properties of the obtained copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide drawn fiber.

<Example 4>
[Manufacture of copolyparaphenylene 3,4'-oxydiphenylene terephthalamide fibrils]
A copolyparaphenylene 3,4′-oxydiphenylene terephthalamide fibril was obtained in the same manner as in Example 1 except that the number of holes in the spinneret was 500. Table 1 shows the fineness, the number of filaments, and the single yarn diameter of the obtained copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide fibrils.

[Production of Copolyparaphenylene 3,4'-oxydiphenylene terephthalamide drawn fiber]
Subsequently, a copolyparaphenylene-3,4′-oxydiphenylene-terephthalamide drawn fiber was produced in the same manner as in Example 1 except that the width of the fiber bundle in the high-tensile hot drawing process was changed to 10 mm. Table 1 shows the physical properties of the obtained copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide drawn fiber.

<Example 5>
[Manufacture of copolyparaphenylene 3,4'-oxydiphenylene terephthalamide fibrils]
Copolyparaphenylene 3,4′-oxydiphenylene terephthalamide fibrils were obtained in the same manner as in Example 1 except that the number of holes in the spinneret was changed to 1500. Table 1 shows the fineness, the number of filaments, and the single yarn diameter of the obtained copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide fibrils.

[Production of Copolyparaphenylene 3,4'-oxydiphenylene terephthalamide drawn fiber]
Subsequently, a copolyparaphenylene-3,4′-oxydiphenylene-terephthalamide drawn fiber was produced in the same manner as in Example 1 except that the width of the fiber bundle in the high-tensile hot drawing process was changed to 10 mm. Table 1 shows the physical properties of the obtained copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide drawn fiber.

<Comparative Example 1>
[Manufacture of copolyparaphenylene 3,4'-oxydiphenylene terephthalamide fibrils]
In the same manner as in Example 1, copolyparaphenylene 3,4′-oxydiphenylene terephthalamide fibrils were obtained. Table 2 shows the fineness, the number of filaments, and the single yarn diameter of the obtained copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide fibrils.

[Production of Copolyparaphenylene 3,4'-oxydiphenylene terephthalamide drawn fiber]
A copolyparaphenylene-3,4′-oxydiphenylene-terephthalamide drawn fiber was produced in the same manner as in Example 1 except that the width of the fiber bundle in the high-tensile hot drawing process was 3 mm. Table 2 shows properties of the obtained copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide drawn fiber.

<Comparative example 2>
[Manufacture of copolyparaphenylene 3,4'-oxydiphenylene terephthalamide fibrils]
In the same manner as in Example 4, copolyparaphenylene 3,4′-oxydiphenylene terephthalamide fibrils were obtained. Table 2 shows the fineness, the number of filaments, and the single yarn diameter of the obtained copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide fibrils.

[Production of Copolyparaphenylene 3,4'-oxydiphenylene terephthalamide drawn fiber]
A copolyparaphenylene-3,4′-oxydiphenylene-terephthalamide drawn fiber was produced in the same manner as in Example 4 except that the width of the fiber bundle in the high-tensile hot drawing process was changed to 2 mm. Table 2 shows properties of the obtained copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide drawn fiber.

<Comparative Example 3>
[Manufacture of copolyparaphenylene 3,4'-oxydiphenylene terephthalamide fibrils]
In the same manner as in Example 5, copolyparaphenylene-3,4′-oxydiphenylene-terephthalamide fibrils were obtained. Table 2 shows the fineness, the number of filaments, and the single yarn diameter of the obtained copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide fibrils.

[Production of Copolyparaphenylene 3,4'-oxydiphenylene terephthalamide drawn fiber]
A copolyparaphenylene-3,4′-oxydiphenylene-terephthalamide drawn fiber was produced in the same manner as in Example 5 except that the width of the fiber bundle in the high tension hot drawing process was changed to 4 mm. Table 2 shows properties of the obtained copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide drawn fiber.

  The copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide drawn fiber of the present invention is a fiber excellent in tensile elastic modulus. At the same time, since the breakage of the single yarn constituting the fiber is suppressed, the fiber has high tensile strength. Therefore, the copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide drawn fiber of the present invention is useful for various industrial materials, and particularly useful for reinforcing materials such as rubber and resin, ropes, and the like. is there.

Claims (5)

  Copolyparaphenylene 3,4'-oxydiphenylene terephthalamide drawn fiber having a tensile modulus of elasticity of 665 cN / dtex or more.   The copolyparaphenylene 3,4'-oxydiphenylene terephthalamide drawn fiber according to claim 1, which has a tensile strength of 25.5 cN / dtex or more. The high-strength hot drawing is performed on the copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide fibril so that the width of the fiber bundle satisfies the formula (1). A method for producing 3,4′-oxydiphenylene terephthalamide drawn fiber.
Width of fiber bundle (mm) ≧ single yarn diameter (mm) × number of single yarns (pieces) / 3 (1)   The method for producing a copolyparaphenylene 3,4'-oxydiphenylene terephthalamide drawn fiber according to claim 3, wherein the high-tensile hot drawing is performed at a temperature in the range of 50 to 450 ° C.   5. The method for producing a copolyparaphenylene 3,4'-oxydiphenylene terephthalamide drawn fiber according to claim 3 or 4, wherein the high-tensile thermal drawing is performed in a tension range of 30 to 60N.