JPH059867A - Aromatic polyamide fiber - Google Patents

Abstract

PURPOSE:To obtain the subject fiber having a high knot strength by applying fine silicone resin particles having a specific particle diameter or below to the surface of aromatic polyamide fiber having a low knot ratio. CONSTITUTION:Aromatic polyamide fiber having a high knot strength is obtained by applying 0.1-10wt.% fine silicone resin particles having <=40mum average particle diameter to the surface of aromatic polyamide fiber having a low knot ratio. Furthermore, silicone resin particles having a shape of >0.4 and pi/6 (f) (volume shape factor) exhibit remarkable effects as the fine silicone resin particles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to aromatic polyamide fibers, and more particularly to aromatic polyamide fibers having a high knot strength in which silicon resin fine particles are adhered to the surface of the fibers.

[0002]

2. Description of the Related Art In recent years, various new fiber materials have been developed to meet the demand for high strength and high modulus for fibers. Aromatic polyamide fiber is one of such fiber materials and has high strength and high modulus, but in terms of knot strength, the high strength cannot be fully utilized, and the so-called knot ratio is very low. Therefore, it could not be used for rope ends, fishing nets, fishing lines, etc.

[0003]

It is an object of the present invention to provide an aromatic polyamide fiber having a high knot strength by improving the low knot ratio.

[0004]

That is, the present invention (claim 1) is an aromatic polyamide fiber characterized in that 0.1 to 10% by weight of silicon resin fine particles having an average particle diameter of 4 μm or less are adhered to the fiber surface. . (Claim 2) The aromatic polyamide fiber according to claim 1, wherein the volumetric shape factor (f) of the silicon resin fine particles defined by the following formula is more than 0.4 and π / 6 or less. f = V / D (where V is the average volume (μm ³ ) per particle, and D is the average maximum particle size (μm) of the particles.) Aromatic polyamide ( The aramid) is composed of an aromatic polyamide or an aromatic copolyamide in which 80 mol% or more, preferably 80 mol% or more of the repeating units are composed of the following repeating units.

[0005]

[Chemical 1] (Here, Ar1 and Ar2 are the same or different aromatic residues selected from the following groups. However, the hydrogen atom of the aromatic residue may be substituted with a halogen atom or a lower alkyl group. .)

[0006]

[Chemical 2] X is selected from the following groups.

[0007]

[Chemical 3]

Regarding the method for producing such an aromatic polyamide, for example, British Patent No. 1501948, US Pat. No. 3,738,964, Japanese Patent Laid-Open No. 49-100522.
It is described in Japanese Patent Publication No.

The silicon resin fine particles have a network structure and have an average particle diameter of 4 μm or less. When it exceeds 4 μm, not only a large amount of silicon resin fine particles are required to uniformly coat the fiber surface, but also the amount of silicon resin fine particles to be detached in the yarn making process or the processing process becomes large, which is not preferable.

The shape of the silicon resin fine particles is such that the volume shape factor (f) defined by the following equation is larger than 0.4 and π / 6.
A remarkable effect is exhibited when the following shapes are used.

The amount of silicon resin fine particles applied is 0.
It is 1 to 10% by weight.

If it is less than 0.1% by weight, the effect of improving the knot strength is insufficient.

If it exceeds 10% by weight, the diameter of the fiber bundle becomes too large, which is impractical. In addition, the amount of scum in the process becomes extremely large, which deteriorates post-processability.

The method of applying the silicon resin fine particles includes a method of applying immediately before winding or a method of applying before stretching, but any method can be used.

When applied just before winding, the silicone resin fine particles may be dispersed and applied in an oil agent necessary for post-processing.

An oiling roller may be used as a device for applying, but dipping is preferred for uniform application.

If stretching is necessary, it may be applied before stretching.

[0018]

As described above, when the silicone resin fine particles are attached to the surface of the aromatic polyamide fiber, the knot strength of the obtained fiber is remarkably improved. It is thought that this is because the silicon resin particles distributed between the single yarns significantly reduce the friction between the single yarns and prevent the stress concentration at the knots. Silicon resin fine particles are suitable for this purpose, and spherical silicon resin fine particles are most suitable.

The aromatic polyamide fiber of the present invention has a high knot strength which has never been obtained, and is useful in many fields such as ropes, fishing nets and fishing lines that require high knot strength.

The present invention will be described below with reference to examples.

In the examples, each characteristic value was measured by the following method.

(1) Intrinsic viscosity of polymer (IV) An Ostwald type viscometer was used. Flow time of solvent only is t. (Sec), the flow-down time of the dilute polymer solution is t
(Sec), the polymer concentration in the dilute solution is c (g / dl)
Then IV is represented by the following formula. IV = ln (t / t.) / C Solvent is 97.5% concentrated sulfuric acid, c = 0.5 g / dl, measurement temperature is 30 ° C.

(2) Tensile properties of fiber Using an Instron tensile tester, the load elongation curve was measured in an atmosphere of an initial length of 25 cm, a pulling speed of 10 cm / min, a temperature of 20 ° C. and a humidity of 65% RH. / D), elongation (%), Young's modulus (g / d) were calculated.

(3) Knot strength property of fiber A knot was made in the center of the sample under the same conditions as the tensile property of the fiber, and the load elongation curve was measured, and the knot strength was calculated from this.

(4) Volumetric shape factor (f) A photograph of silicon resin fine particles was taken with a scanning electron microscope.
10 fields of view were photographed at 0 times, the average value of the maximum diameter was measured for each field using an image analysis processor, Ruzex 500 (manufactured by Nippon Regulator), and the average value of 10 fields of view was calculated. And

The average volume (V = π / 6 × d) of the particles was obtained from the average particle diameter d obtained by the centrifugal sedimentation type particle size measuring device, and the volume shape factor f was calculated by the following formula.

F = V / D V is the average volume of the particles (μm ³ ), D is the average maximum particle size of the particles (μm)

[0028]

[Example 1] The following monomer units

[0029]

[Chemical 4]

[0030]

[Chemical 5]

[0031]

[Chemical 6] (N-methyl-2-pyrrolidone (N) containing calcium chloride was used as an aromatic copolyamide of IV = 3.4 composed of (25 mol%, 25 mol%, 50 mol%, respectively).
A polymer solution prepared by dissolving 6% by weight in MP) was fed from a spinneret having a pore size of 0.3 mm and a pore number of 1000 at 1350 g /
Extruded at a minute discharge rate. After running the spun yarn in the air for 8 mm, the spun yarn was coagulated in an NMP / water mixed coagulation bath (mixing ratio 30/70% by weight) at 50 ° C. and taken up at a speed of 47 m / min, followed by a 50 ° C. water bath. After washing, it was dried with a heating roller at 200 ° C., stretched 2.1 times on a hot plate having a length of 390 ° C. and a length of 200 cm, and then stretched 5 times on a hot plate having a length of 520 ° C. and a length of 300 cm. .

After that, spherical silicon resin (f = 0.5)
Was added to the finished oil, dried at 500 m / min, and wound up.

The amount of the spherical silicon resin fine particles applied at this time was 1.7%.

The knot strength of the obtained fiber was 8.6 g / d, which was extremely high and good.

[0035]

Examples 2 to 4 and Comparative Examples 1 to 2 The same procedure as in Example 1 was carried out except that the amount of silicone resin particles applied was changed as shown in Table 1. The results are shown in Table 1.

1 and 2 are electron micrographs (× 5000 times and × 800 times, average particle diameter 1.2 μm, applied amount 6.0%) of the side surface of the fiber obtained in Example 4. .

[0037]

Comparative Example 3 Comparative Example 3 is an example in which the diameter of the silicon resin fine particles is changed. The results are shown in Table 1.

[0038]

[Embodiment 5] Embodiment 5 is an example in which amorphous silicon fine particles are used. The results are shown in Table 1.

[0039]

[Table 1]

[Brief description of drawings]

FIG. 1 is an electron micrograph (× 5000 times, average particle size 1.2 μm, applied amount 6.0%) of the surface of an aromatic polyamide fiber having silicon resin particles.

FIG. 2 is an electron micrograph (× 800 times, average particle diameter 1.2 μm, applied amount 6.0%) of the surface of an aromatic polyamide fiber having silicon resin fine particles.

Claims (2)

[Claims] 1. An aromatic polyamide fiber, characterized in that 0.1 to 10% by weight of silicon resin fine particles having an average particle size of 4 μm or less are adhered to the fiber surface. 2. The aromatic polyamide fiber according to claim 1, wherein the volumetric shape factor (f) of the silicon resin fine particles defined by the following formula is more than 0.4 and π / 6 or less. f = V / D (where V is the average volume (μm ³ ) per particle, and D is the average maximum particle size (μm) of the particles.)