JPH06341016A - Black mass-colored polyamide fiber having high toughness - Google Patents

Abstract

PURPOSE:To provide a black mass-colored polyamide fiber having high toughness represented by the strength of >=8.0g/d and the elongation of >=22%, exhibiting excellent weather resistance and suitable for industrial material. CONSTITUTION:The black mass-colored polyamide fiber having high toughness is a polyamide fiber having a strength of >=8.0g/d and an elongation of >=22% and containing 0.2-1.0wt.% of finely dispersed carbon black particles having particle diameter of <=300mum. Carbon black produced by channel process is used as the above carbon black. The content of the carbon black in the fiber is 0.2-1.0wt.%.

Description

Detailed Description of the Invention

[0001]

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

[0002]

BACKGROUND OF THE INVENTION Black dyed polyamide fibers have excellent toughness and durability and can be used without dyeing, so they are used for industrial materials such as fishing nets, belts, strings, civil nets, and tarpaulins. Is used to be preferred.

In the above industrial material applications, it is required to reduce the amount of materials used from the viewpoints of weight reduction and economy, while at the same time constantly increasing strength and elongation, that is, increasing toughness. is necessary.

However, the black dyed polyamide fiber can be obtained by incorporating carbon black particles. In this case, however, the carbon black particles act as a foreign substance in the fiber, so that yarn breakage easily occurs in the yarn making process,
It is difficult to obtain a high toughness yarn that is higher than that of the conventional yarn. For example, it is difficult to industrially produce a high toughness polyamide fiber having a strength of 8.0 g / d and an elongation of 22% or more.

The above problem is caused by the carbon black itself.
Although the secondary particle size is usually as small as several tens of mμ,
This is because, when blended with the polyamide polymer to form fibers, some of the particles are dispersed in the fibers as particles aggregated to have a particle size of about 10 times or more, and they act as foreign substances.

In order to remove such foreign matters, attempts have been made to enhance the filtration in the spinning pack, but in this case, a rapid increase in the filtration pressure occurs, so that the replacement cycle of the pack filter should be shortened. It has not been solved yet.

Therefore, in the production of high-toughness black dyed polyamide fibers, how to finely disperse carbon black particles is an important point. As a technique for improving the dispersibility of such carbon black particles, for example, Japanese Patent Laid-Open No. The method described in JP-A-3-220313 has been proposed.

That is, the technique disclosed in Japanese Patent Application Laid-Open No. 3-220313 is described as follows: "When a black-dyed polyamide fiber containing carbon black having primary particles of 20 mμ or less is spun, a fatty acid amide is added based on the weight of the polyamide.
Disclosed is a method for producing a polyamide fiber, which comprises using a polyamide in an amount of not less than 05% by weight.

However, when this technique is applied to the production of black-dyed polyamide fiber for industrial materials, although a toughness fiber having a slightly higher level than that of the prior art is obtained, the level required for industrial material use, that is, the strength of 8 ．
When trying to obtain a high toughness fiber having 0 g / d or more and an elongation of 22% or more, yarn breakage frequently occurs in the drawing process, and the surface of the drawing roll is rapidly worn, which makes industrial production impossible. 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, it has been practiced to use organic pigments instead of carbon black. Although this method certainly avoids the obstacles caused by carbon black, it has a problem that the excellent weather resistance, which is a characteristic of carbon black-containing black-dyed polyamide fiber, is lost and that 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 of 8.0 g / d or more in strength and 22% or more in elongation. In addition, it is intended to provide black-dyed polyamide fiber having excellent weather resistance and suitable for industrial materials.

[0012]

In order to achieve the above object, the high toughness black dyed polyamide fiber of the present invention contains carbon black particles finely dispersed to 300 mμ or less in the polyamide fiber and has a strength of 8 It is characterized by having characteristics of 0.0 g / d or more and an elongation of 22% or more.

The high toughness black dyed polyamide fiber of the present invention is characterized in that carbon black produced by the channel method is used as the 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 wt%.

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

In the case of a polyamide fiber containing no carbon black, a high toughness of the above level can be obtained,
No industrially produced examples of polyamide fibers containing 0.2 to 1.0% by weight of carbon black and having the above-mentioned high toughness characteristics have been found yet.

Examples of the polyamide polymer used in the present invention include nylon 6, nylon 66, nylon 46 and the like, and a copolymer polymer or a blend polymer in which these are combined can also be used.

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

The high toughness polyamide fiber of the present invention is characterized by containing 0.2 to 1.0% by weight of preferably channel type carbon black, which is finely dispersed in the fiber to 300 mμ or less as a black dyeing component. .

The term "channel type carbon black" as used herein means carbon black produced by the channel method.

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

Furnace type carbon blacks have poor dispersibility in polyamide polymers, but a more serious drawback is that the polyamide fibers containing the carbon blacks are in contact with metals such as rolls, hotplates and guides which are contacted during the spinning process. That is, the polyamide fiber that has worn out the metal and has come into contact with the metal in the worn portion is often broken.

This phenomenon has been recognized in the past, and in order to avoid such obstacles related to metal wear, rolls, heat, etc. which come into contact in the yarn making process of the black-dyed polyamide fiber and in the product processing process using this fiber, The reality is that the frequency of replacement of plates and guides has been increased to take measures.

In particular, in recent years, the direct spinning / drawing method has been adopted as a yarn-making method for coping with the demands for higher toughness and production efficiency, so that the above-mentioned drawbacks have been fatal.

That is, when polyamide fiber containing furnace type carbon black is directly spun and drawn, high toughness fiber having a strength of 8.0 g / d or more and an elongation of 22% or more cannot be obtained, and particularly high tensile strength is obtained. The surface of such a stretched roll is abraded, and as the abrasion progresses, yarn breakage frequently occurs. Therefore, it has been unavoidable to abandon industrial production.

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

The state of fine dispersion of carbon black particles is
The sample can be confirmed by a transmission electron microscope, for example, a sample prepared by an ultrathin section method, and observed by using a TEM1200EX manufactured by JEOL Ltd. at an acceleration voltage of 100 KV.

In the present invention, the state in which carbon black particles are finely dispersed means that, in the above photograph, 20 particles are selected in order from the one having the largest particles, and the average value thereof is 300 mμ.
The following means that it is preferably 250 mμ or less.

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

Examples of the dispersant used herein include higher fatty acid amide compounds such as ethylenebisstearylamide, styrenebisstearylamide, stearic acid amide and palmitic acid amide, and paraffins, waxes,
Higher fatty acids, esters of monoglycerin, higher fatty acid alcohols, metal soaps and the like are used.

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

Carbon black is usually added or blended at a high concentration of 10 to 40% by weight with respect to polyamide during polymerization to form a master chip. Then, the master chip is blended with a nylon polymer and is spun into yarn to produce the black-dyed polyamide fiber of the present invention.

The carbon black concentration is suitably 0.2 to 1.0% by weight based on the polyamide fiber. If it is less than 0.2% by weight, black coloring is insufficient, and if it exceeds 1.0% by weight, the physical properties of the fiber may deteriorate.

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

The polymer used as the master chip is generally the same type as the high toughness black dyed polyamide according to the present invention, but it is also possible to use polymers having different degrees of polymerization and polyamide types.

The surface of the high toughness black-dyed polyamide fiber of the present invention was 5,000-fold or 10,000-fold by FE-SEM.
Observed at a magnification of about 100 to 3 on the surface of the filament.
Unevenness of 00 mμ is dispersed almost uniformly, and it is observed in the conventional black-dyed polyamide fiber containing furnace-type carbon black. It is formed on the entire surface of the filament and contains cracks parallel to the fiber axis and carbon black particles. The feature is that no fish-eye-like cracks are observed.

Next, a specific example of the method for producing the high-toughness black-dyed polyamide fiber of the present invention will be described.

First, in order to produce a black dyed master chip, a polyamide polymer having a relative viscosity of sulfuric acid of 3.0 or more was used in 10 parts.
0 part, 10 to 30 parts of channel type carbon black having a primary particle size of 20 mμ or less, and 1 to 10 parts of the dispersant.
Parts or 10 to 40 parts of nylon copolymer polymer are mixed and melted using a twin-screw extruder and spun. The spun gut is introduced 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 above master chips and separately prepared polyamide chips are placed in separate hoppers, weighed by respective weighing blenders installed under the hoppers, 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 through the spinneret pores. Next, cold air is blown onto the spun yarn to cool and solidify it, and then an oil agent is applied.

The oil agent contains a generally used leveling agent and activator as main components, and contains a trace amount of an antistatic agent and an extreme pressure agent. Since the high toughness black dyed polyamide fiber of the present invention is produced by the direct spinning and 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, it is taken up by a take-up roll, and subsequently, a crude oil agent is applied while applying a stretch of 1 to 10% with a yarn-feeding roll. Give. The amount of the oil agent applied is preferably adjusted to be 0.5 to 1.5% by weight as the product thread.

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 feeding roll is increased by about 4 times. On the other hand, in the method for producing high-toughness black dyed polyamide fiber according to the present invention, it is possible to maintain the pre-stretch tension as low as almost the same level as in the case of polyamide fiber containing no carbon black.

For example, when the stretch is 5%, the tension of the polyamide fiber according to the present invention is 0.2 to 0.4 g per denier of the stretched fiber, whereas the furnace type carbon black is used. If 0.9
It is 1.4 g.

Next, after performing two-stage hot drawing with the yarn feeding roll and two pairs of Nelson rolls, a relaxation heat treatment of 2 to 10% is carried out between the yarn and the relaxing roll and winding. The speed of the take-up roll, that is, the spinning speed is 300 to 1000 m.
The stretching speed and the stretching speed are preferably in the range of 1500 to 4000 m / min. The maximum temperature applied for stretching is preferably set between the melting point of the polyamide and a temperature 40 ° C. lower than the melting point.

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

The state of dispersion of carbon black observed by TEM using an ultrathin section method has a maximum maximum particle size of 200-200.
Some of them are 300 mμ, but most of them are evenly dispersed as finer particles.

On the surface of the filament observed by FE-SEM, irregularities of about 100 to 300 mμ are uniformly dispersed, but cracks in the fiber axis direction are not observed.

The high toughness black-dyed polyamide fiber of the present invention has excellent weather resistance equivalent to that of the conventional black-dyed polyamide fiber.

As a further effect, the high-toughness black-dyed polyamide fiber of the present invention has the advantage that, as a result of fine dispersion of carbon black, a vivid black color is formed even when the content is several tens% less than in the past. To be

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

[0051]

Examples 1 to 3 Nylon 6 chips having a sulfuric acid relative viscosity of 3.4 were mixed with 20% by weight of channel type carbon black ("special black") and 2% by weight of ethylenebisstearylamide to prepare master chips. Manufactured.

1 part by weight of the above master chip and 39 parts by weight of the same nylon 6 chip as that used for the master chip were weighed and mixed, and melted by an extruder type spinning machine. The molten polymer was filtered through a metal nonwoven fabric having an average pore diameter of 20μ in a spinning pack, and then the pore diameter was 0.5 mm and the number of pores was 2
It was spun through a spinneret of No. 8.

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

Next, the undiluted oil agent was applied to the take-up yarn by applying 5% stretch between the take-up roll and the yarn-feeding roll heated to 50 ° C. The oil agent was applied so as to be about 1% by weight with respect to the raw yarn, about 0.2% by weight before the take-up roll, and the rest was applied between the take-up roll and the yarn feeding roll.

The tension when the above 5% stretch was applied was as low as the tension when a polymer without carbon black was spun.

Subsequently, the yarn is fed to a yarn feeding roll and 120 ° C.
The film was stretched 3.0 times with the Nelson type first drawing roll heated to 1, and further drawn 1.5 times with the Nelson type second drawing roll heated to 210 ° C.

Further, the stretched yarn was wound with a relaxation heat treatment of 8% between it and a Nelson type relaxing roll at 120 ° C.

According to the above method, 840D-28fil
A black-dyed polyamide fiber was obtained.

Regarding this black-dyed polyamide fiber, the master chip composition, 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, respectively, as Example 1.

In Table 2, EBA means ethylene bis-stearyl amide, and the evaluation results of roll wear properties are shown below. ⊚: Almost no wear after 1 month x: 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 dispersibility of carbon black, does not cause roll wear, and is excellent. It also possessed weather resistance.

In addition, as in Example 1, channel type carbon black was used, and a master chip in which conditions were slightly changed as shown in Table 1 was used. , Shown as Example 3.

As is clear from the results in Table 2, the black-dyed polyamide fibers in Examples 1 and 2 also
High toughness and good dispersibility of carbon black,
It did not cause roll abrasion and had excellent weather resistance.

[0064]

[Table 1]

[Table 2]

[0065]

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

As is clear from the results shown in Tables 1 and 2, when the furnace type carbon black is used, the strength and elongation are low, roll wear occurs, and often thread breakage occurs, and 5 before the drawing. There is a problem that the tension during% stretching is significantly increased.

On the other hand, when the organic pigment was used, both the physical properties of the fiber and the spinnability were good and roll abrasion did not occur, but the weather resistance was significantly inferior to the conventional black dyed polyamide fiber.

[0068]

As explained above, the high-toughness black-dyed polyamide fiber of the present invention has a strength of 8.0 g / d or more and an elongation of 22% or more, which is unprecedentedly high toughness.
Since it also 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 taking advantage of the characteristic that the toughness is higher than that of the conventional black dyed polyamide fiber, the weight can be reduced and the manufacturing cost is also advantageous.

Further, in the high-toughness black dyed polyamide fiber of the present invention, since the particles of the channel type carbon black are extremely finely dispersed in the polyamide, a clear black color is obtained even if the carbon black content is reduced by several tens of%. It has the characteristic of developing color.

Further, in the process for producing the high toughness black dyed polyamide fiber and the process for commercializing the fiber of the present invention, even when the fiber comes into contact with the metal such as the roll, the hot plate and the guide, the abrasion of the metal is remarkably reduced. Therefore, there is an advantage that the replacement cycle of these metal devices and parts can be extended.

The high toughness black dyed polyamide fiber of the present invention is other than the polyamide fiber for industrial materials, for example, black dyed yarn for carpet, conductive core-sheath fiber containing carbon black, black dyed monofilament monofilament, or polyamide fiber. It can also be applied to black dyed fibers.

Claims (3)

[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-dyed polyamide fiber having characteristics of 0 g / d or more and an elongation of 22% or more. 2. The high toughness black dyed polyamide fiber according to claim 1, wherein the carbon black particles are carbon black produced by a channel method. 3. Carbon black particles are added in an amount of 0.2-1.
The high-toughness black-dyed polyamide fiber according to claim 1 or 2, wherein the content is 0% by weight.