JP3265714B2 - High toughness black raw polyamide fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high toughness black-dyed polyamide fiber, and more particularly, to industrial materials such as fishing nets, belts, strings, civil engineering nets, and tarpaulins, which are excellent in toughness and durability. The present invention relates to a high-toughness black-stained polyamide fiber suitable for the above.

[0002]

2. Description of the Related Art Since black-stained polyamide fibers have excellent toughness and durability and can be used without dyeing, they are used for industrial materials such as fishing nets, belts, strings, civil engineering nets, and tarpaulins. Used to be preferred.

[0003] In the use of the above-mentioned industrial materials, it is required to reduce the amount of material used from the viewpoint of weight reduction and economy. On the other hand, it is necessary to always increase strength and elongation, that is, to increase toughness. is needed.

[0004] However, black-dyed polyamide fibers can be obtained by incorporating carbon black particles. In this case, since the carbon black particles act as foreign matter in the fibers, yarn breakage is likely to occur in the spinning process.
It has been difficult to obtain high toughness yarns higher than conventional yarns. For example, it has been difficult to industrially produce high toughness polyamide fibers having a strength of 8.0 g / d and an elongation of 22% or more.

[0005] The above-mentioned problem is caused by one of carbon black itself.
Although the secondary particle size is usually as small as tens of μm,
When a fiber is formed by blending with a polyamide polymer, a part thereof is dispersed in the fiber as particles agglomerated to a particle diameter of about ten times or more, and these act as foreign matters.

[0006] In order to remove such foreign substances, attempts have been made to enhance filtration in the spinning pack. However, in this case, a rapid increase in filtration pressure occurs, so that the replacement cycle of the pack filter must be increased. And has not actually been resolved.

Therefore, in the production of high toughness black-dyed polyamide fiber, it is important to finely disperse the carbon black particles. As a technique for improving the dispersibility of the carbon black particles, for example, Japanese Patent Application Laid-Open No. A method described in Japanese Patent Application Publication No. 3-220313 has been proposed.

[0008] That is, the technique disclosed in the above-mentioned Japanese Patent Application Laid-Open No. Hei 3-220313 discloses that "when spinning black dyed polyamide fiber containing carbon black having a primary particle size of not more than 20 mμ, fatty acid amide is added to 0.1% based on the weight of polyamide.
A method for producing a polyamide fiber, characterized by using a polyamide containing not less than 05% by weight.

However, when this technology is applied to the production of black-stained polyamide fibers for industrial materials, a toughness fiber having a slightly higher level than that of the conventional technology can be obtained, but the level required for industrial materials, that is, a strength of 8 is required. .
When trying to obtain a high toughness fiber of 0 g / d or more and an elongation of 22% or more, yarn breakage frequently occurs in the drawing step, and the surface of the drawing roll is rapidly worn, so that industrial production cannot be performed. There was a problem.

On the other hand, in order to prevent the carbon black particles from acting as foreign matter in the polyamide fiber and hindering yarn breakage and high toughness, an organic pigment is used instead of carbon black. According to this method, although the problem caused by carbon black can be certainly avoided, there is a problem that excellent weather resistance, which is a characteristic of the carbon black-containing black dyed polyamide fiber, is lost, and the price is generally high.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art, and has a high toughness having a strength of 8.0 g / d or more and an elongation of 22% or more. Another object of the present invention is to provide a black-dyed polyamide fiber which is excellent in weather resistance and suitable for industrial materials.

[0012]

In order to achieve the above-mentioned object, a high toughness black-dyed polyamide fiber of the present invention contains carbon black particles finely dispersed to 300 mμ or less in a polyamide fiber, and has a strength of 8%. It is characterized by having characteristics of not less than 0.0 g / d and elongation of not less than 22%.

Further, the high toughness black dyed polyamide fiber of the present invention is characterized in that carbon black produced by a channel method is used as carbon black particles.

Further, the high toughness black-dyed polyamide fiber of the present invention has a carbon black particle content of 0.2%.
~ 1.0% by weight.

The high toughness black-dipped polyamide fiber of the present invention has a strength of 8.0 g / d or more and an elongation of 22% or more, preferably a strength of 8.2 g / d or more and an elongation of 24% or more. Has characteristics.

In the case of a polyamide fiber containing no carbon black, the above-mentioned high toughness can be obtained.
Polyamide fibers containing 0.2 to 1.0% by weight of carbon black and having the above-mentioned high toughness characteristics have not yet been produced industrially.

Examples of the polyamide polymer used in the present invention include nylon 6, nylon 66, and nylon 46. Copolymers or blend polymers in which these are combined with each other can also be used.

In order to achieve high toughness,
It is desirable to use a high molecular weight polyamide having a sulfuric acid relative viscosity of 3.0 or more. Here, the sulfuric acid relative viscosity is a value measured at 25 ° C. for a sulfuric acid solution having a sample concentration of 1%.

The high toughness polyamide fiber of the present invention contains 0.2 to 1.0% by weight of preferably a channel type carbon black finely dispersed in the fiber to a particle size of 300 μm or less as a black dyeing component. .

The term "channel type carbon black" as used herein refers to carbon black produced by a channel method.

As the conventional black dyed polyamide fiber, furnace type carbon black is generally used. For example, furnace type carbon black is also used in the examples described in JP-A-3-220313.

Furnace type carbon black is poorly dispersible in polyamide polymers, but a further significant drawback is that the polyamide fibers containing this carbon black come into contact with metals, such as rolls, hot plates, and guides, in the spinning process. The polyamide fibers that have been worn and have come into contact with the metal of the worn portion often break.

Such a phenomenon has been conventionally recognized. In order to avoid such an obstacle related to the wear of metal, it is necessary to use a roll, a heat contacting roller in a yarn forming process of a black-dipped polyamide fiber and a product processing process using the fiber. The reality is that measures have been taken to increase the frequency of replacement of boards and guides.

In particular, since the direct spinning and drawing method has recently been adopted as a yarn-making method for meeting the demand for higher toughness and higher production efficiency, the above drawbacks have been fatal.

That is, when a polyamide fiber containing a furnace type carbon black is drawn directly by spinning and drawing, not only a high toughness fiber having a strength of 8.0 g / d or more and an elongation of 22% or more cannot be obtained, but also particularly high tensile strength. The surface of such a draw roll is worn, and thread breakage frequently occurs as the wear progresses, so that the actual situation is that industrial production has to be abandoned.

The high toughness black-dyed polyamide fiber of the present invention is characterized in that the channel type carbon black particles are finely dispersed in the fiber to 300 mμ or less, preferably 250 mμ or less.

The finely dispersed state of the carbon black particles is as follows:
The sample can be prepared by a transmission electron microscope, for example, by an ultra-thin section method, and can be confirmed by a photograph observed at an acceleration voltage of 100 KV using a TEM1200EX manufactured by JEOL Ltd.

In the present invention, the condition in which the carbon black particles are finely dispersed means that 20 particles are sequentially selected from the largest particles in the above photograph, and the average value is 300 mμ.
Or less, preferably 250 mμ or less.

Although the channel type carbon black has a relatively good dispersibility in the polyamide polymer, it is generally desirable to use a dispersant in combination in order to further improve the dispersibility.

Examples of the dispersant include higher fatty acid amide compounds such as ethylene bisstearyl amide, styrene bis stearyl amide, stearic amide, palmitic amide, paraffin, wax,
Higher fatty acids, esters of monoglycerin, higher fatty acid alcohols, metal soaps and the like are used.

Further, as a polymer having a dispersing effect,
Nylon 6, Nylon 66, Nylon 46, Nylon 6
There are binary, ternary or quaternary copolymers such as 10, nylon 11, nylon 12, and the like, and these can be applied.

The carbon black is usually added or blended at a high concentration of 10 to 40% by weight with respect to the polyamide at the time of polymerization to prepare a master chip. Next, the master chip is blended with a nylon polymer to form a yarn, whereby the black-dyed polyamide fiber of the present invention is produced.

The carbon black concentration is suitably 0.2 to 1.0% by weight with respect to the polyamide fiber. If the amount is less than 0.2% by weight, black coloring is insufficient, and if it exceeds 1.0% by weight, fiber properties may be deteriorated.

The amount of the dispersant is preferably 0.01 to 0.1% by weight based on the weight of the polyamide fiber, and 0.1 to 1.0% by weight in the case of a nylon copolymer.
It is desirable to mix the dispersant in the master chip in advance, since the effect of dispersing the carbon black particles in the polyamide is good.

The polymer used as the master chip is generally the same as the high toughness black-colored polyamide according to the present invention, but polymers having different degrees of polymerization and different polyamide types can also be used.

The surface of the high toughness black dyed polyamide fiber of the present invention was 5000 times or 10,000 times by FE-SEM.
When observed at 2x, about 100-3
The irregularities of 00 μm are almost uniformly dispersed, and are formed on the entire surface of the filament, which is observed in black-colored polyamide fibers containing conventional furnace type carbon black, and include cracks and carbon black particles parallel to the fiber axis. It is characterized in that no fisheye-like cracks are observed.

Next, a specific example of the method for producing a black toughened black polyamide fiber of the present invention will be described.

First, a polyamide polymer having a sulfuric acid relative viscosity of 3.0 or more was prepared in order to manufacture a black pigmented master chip.
0 part, 10-30 parts of channel type carbon black having a primary particle diameter of 20 μm or less, and 1-10 parts of the dispersant.
Parts or 10 to 40 parts of a nylon copolymer is mixed and melted using a twin-screw extruder and spun. The spouted gut is guided into a cold water bath to be cooled and solidified, and then cut into cylindrical chips of several mm to obtain master chips.
The master chip is once dried to a moisture content of less than 0.1%.

The master chip and the separately prepared polyamide chip are charged into separate hoppers, weighed by a weighing blender provided under each hopper, and then blended. The blending ratio is adjusted so that the carbon concentration in the polyamide fiber is 0.2 to 1.0% by weight.

The blended chips are continuously melted by a spinning machine, filtered in a spinning pack, and then spun out of a die hole. Next, a cold air is blown onto the spun yarn to cool and solidify the spun yarn, and then an oil agent is applied.

The oil agent contains a generally used leveling agent and activator as main components, and contains trace amounts of an antistatic agent and an extreme pressure agent. Since the high toughness black soaked polyamide fiber of the present invention is produced by a direct spinning drawing method, it is preferable to add a non-aqueous oil agent. After applying an oil agent diluted with a low-viscosity mineral oil to the solidified yarn, the oil agent is taken up by a take-up roll, and then the crude oil agent is stretched by 1 to 10% with a yarn supply roll. Give. It is desirable to adjust the amount of the oil agent to be 0.5 to 1.5% by weight as the product yarn.

[0042] In the case of the conventional black-dyed polyamide fiber containing the furnace type carbon black, the pre-stretch tension generated when stretching is performed between the take-up roll and the yarn supply roll is increased by about four times. On the other hand, in the method for producing a high-toughness black-dyed polyamide fiber according to the present invention, it is possible to keep the pre-stretch tension as low as substantially the same level as in the case of the polyamide fiber containing no carbon black.

For example, when the stretch is set to 5%, the tension of the polyamide fiber according to the present invention is 0.2 to 0.4 g per denier of the drawn fiber, while the furnace type carbon black is used. 0.9 ~
1.4 g.

Next, after performing two-stage heat stretching with the yarn supplying roll and two pairs of Nelson rolls, a 2 to 10% relaxation heat treatment is performed between the yarn and the relax roll to wind up. The speed of the take-off roll, that is, the spinning speed is 300 to 1000 m
And the stretching speed are preferably in the range of 1500 to 4000 m / min. The highest temperature applied for stretching is desirably set between the melting point of the polyamide and a temperature 40 ° C. lower than the melting point.

The thus produced high toughness black soaked polyamide fiber of the present invention has a strength of 8.0 g / d or more and an elongation of 2 g / d.
High toughness of 2% or more.

The dispersion state of the carbon black observed by the ultra-thin section method with a TEM is partially limited to a maximum particle size of 200 to 200.
Some are 300 μm, but most are evenly dispersed as finer particles.

On the surface of the filament observed by FE-SEM, irregularities of about 100 to 300 μm are uniformly dispersed, but no crack is observed in the fiber axis direction.

The high-toughness black-stained polyamide fiber of the present invention has the same excellent weather resistance as the conventional black-stained polyamide fiber.

As yet another effect, the high toughness black-dyed polyamide fiber of the present invention has an advantage that, as a result of fine dispersion of carbon black, a clear black color is produced even if the content is several tens percent lower than in the prior art. Can be

Next, embodiments of the present invention will be described in detail with reference to examples.

[0051]

EXAMPLES 1-3 A master chip was prepared by mixing 20% by weight of channel type carbon black ("special black") and 2% by weight of ethylene bisstearylamide with nylon 6 chips having a sulfuric acid relative viscosity of 3.4. Manufactured.

1 part by weight of the master chip and 39 parts by weight of the same nylon 6 chip used for the master chip were melted by an extruder spinning machine while being mixed and measured. After filtering the molten polymer through a metal nonwoven fabric having an average pore size of 20 μm in a spin pack, the pore size is 0.5 mm, the number of pores is 2
The spinning was performed through a nozzle 8.

After the spun yarn was solidified by cooling with cold air at 20 ° C., an oil agent diluted to 20% by weight with a higher hydrocarbon having carbon atoms of C13 was applied, and the spun yarn was taken off at a speed of 500 m / min by a take-off roll. .

Next, the stock solution was applied to the take-up yarn while applying 5% stretch between the take-up roll and the yarn supply roll heated to 50 ° C. The oil was applied so as to be about 1% by weight based on the original yarn, but about 0.2% by weight before the take-up roll, and the rest was applied between the take-up roll and the yarn supply roll.

The tension when the above 5% stretch was applied was as low as that in the case where the polymer was prepared without adding carbon black.

Subsequently, the yarn was fed to a yarn feed roll at 120 ° C.
The film was stretched 3.0 times with a Nelson-type first stretching roll heated to 1.5 ° C., and further 1.5 times with a Nelson-type second stretching roll heated to 210 ° C.

Further, the drawn yarn was subjected to an 8% relaxation heat treatment between a Nelson-type relax roll at 120 ° C. and wound up.

According to the above method, 840D-28fil
Was obtained.

With respect to the black-dyed polyamide fiber, the master chip composition, the black-dyed polyamide fiber component and 5%
The tension during stretching is shown in Table 1, and the physical properties of the fiber and the dispersibility of carbon black are shown in Table 2, as Example 1.

In Table 2, EBA means ethylenebisstearylamide, and the results of evaluation of roll abrasion are as follows. …: Almost no wear after one month ×: Significant wear after 3 days

As is clear from the results shown in Table 1, the black dyed polyamide fiber of the present invention has high strength and elongation, high toughness, good carbon black dispersibility, not only does not cause roll abrasion, but also has excellent properties. It also possessed weather resistance.

Further, the results obtained by using the channel type carbon black in the same manner as in Example 1 and using the master chip with slightly changed conditions as shown in Table 1 are shown in Tables 1 and 2. , And Example 3.

As apparent from the results in Table 2, the black-colored polyamide fibers in Examples 1 and 2 also
High toughness and good dispersibility of carbon black,
The roller had good weather resistance without causing roll abrasion.

[0064]

[Table 1]

[Table 2]

[0065]

Comparative Examples 1 to 4 Instead of the channel type carbon black used in Examples 1 to 3, a master chip using a conventional furnace type carbon black or an organic pigment as a black coloring agent was used. The results of spinning in the same manner are shown in Tables 1 and 2 as Comparative Examples 1 to 4.

As is evident from the results in Tables 1 and 2, when the furnace type carbon black was used, the strength and elongation were low, roll abrasion often occurred, and not only yarn breakage often occurred, but also the 5 There is a problem that the tension at the time of% stretching is significantly increased.

On the other hand, when the organic pigment was used, both the fiber properties and the spinning properties were good and no roll abrasion occurred, but the weather resistance was significantly inferior to that of the conventional black-dyed polyamide fiber.

[0068]

As described above, the high-toughness black soaked polyamide fiber of the present invention has an unprecedented high toughness of 8.0 g / d in strength and 22% in elongation.
In addition, since it has excellent weather resistance, it can be desirably applied to industrial materials such as fishing nets, belts, strings, civil engineering nets, and tarpaulins. In addition, since the amount of fibers in the product can be reduced by making use of the characteristic of higher toughness than the conventional black-stained polyamide fiber, the weight can be reduced and the production cost is also advantageous.

In the polyamide fiber having a high toughness of the present invention, channel type carbon black particles are extremely finely dispersed in the polyamide. It has the characteristic of developing color.

Further, in the process of producing the high toughness black-dyed polyamide fiber of the present invention and the step of producing the fiber, the abrasion of the metal is remarkably reduced even if the fiber comes into contact with metals such as rolls, hot plates and guides. Therefore, there is an advantage that the replacement cycle of these metal devices and parts can be extended.

The high-toughness black-stained polyamide fiber of the present invention is not limited to polyamide fibers for industrial materials, for example, black-stained yarn for carpet, conductive core-sheath fiber containing carbon black, black-stained monofilament monofilament, or polyamide fibers other than polyamide fibers. Can also be applied to the black dyed fiber.

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Claims (3)

(57) [Claims] 1. A polyamide fiber containing carbon black particles finely dispersed to 300 mμ or less, and having a strength of 8.
A high toughness black soaked polyamide fiber having a characteristic of 0 g / d or more and an elongation of 22% or more. 2. The high toughness black soaked polyamide fiber according to claim 1, wherein the carbon black particles are carbon black produced by a channel method. 3. The method according to claim 1, wherein the carbon black particles comprise 0.2 to 1.
The high toughness black soaked polyamide fiber according to claim 1 or 2, which is contained in an amount of 0% by weight.