JPH0941217A - Method for producing roughened polyamide fiber - Google Patents

Abstract

(57) Abstract: [PROBLEMS] To provide a method for producing a polyamide fiber having an uneven surface due to protrusions of the polyamide itself. SOLUTION: In a polyamide, the amount of terminal carboxyl groups is more than that of terminal amino groups by 30 g eq / 10 ⁶ or more,
A method for producing a surface-roughened polyamide fiber having irregularities on the surface, which comprises blending a certain amount of a hindered amine compound having a specific structure and spinning the mixture and imparting an aqueous emulsion to the discharged yarn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a roughened polyamide fiber having fine irregularities on the fiber surface. More specifically, the present invention relates to a method for producing a polyamide fiber which does not have a slimy feeling peculiar to polyamide and which is advantageously used for a woven or knitted fabric and has an improved feeling.

[0002]

2. Description of the Related Art Generally, polyamide fibers are widely used as a general fiber material for clothes because of their excellent properties. However, since it has a slimy feeling peculiar to its texture and touch as compared with natural fibers such as cotton and silk, it is limited to a specific field in application development, and its range is limited as compared with natural fibers. Specifically, in the case of polyamide fiber, the water absorbency is poor, so that the slimy feeling at the time of sweating is disliked, and the application to underwear, outwear, kimono applications, etc. is extremely small.

Conventionally, it has been proposed to cover such a defect and give a texture and luster close to that of a natural material without sacrificing the good properties of the polyamide fiber.
For example, various methods have been proposed to remove the slimy feeling peculiar to polyamide fibers by partially removing the polyester component from the mixed spun fiber of polyamide and polyester and forming streak-shaped fine pores in the length direction of the fiber surface. (For example, Japanese Examined Patent Publication No. 42-27574, Japanese Examined Patent Publication No. 4)
(See JP 4-218805 A and JP 2-175965 A).

Further, various methods have been proposed in which a polyamide is blended with a polyalkylene ether compound for the purpose of improving gloss and feeling and melt-spun, and then the polyalkylene ether compound is eluted and removed in water. (For example, Japanese Patent Publication No. 55-10685, Japanese Patent Publication No. 58-1)
2935, Japanese Patent Publication No. 58-12936 and Japanese Patent Publication No. 6-104931).

[0005] None of these methods is suitable for industrial production because the yarn-forming property and the post-processability are deteriorated. Among them, there is a proposal to improve the spinnability by improving the compatibility of polyamide and polyester or a polyalkylene ether compound, but in any case, a step of elution and removal is necessary and a method that is sufficiently satisfactory in terms of cost. is not.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an industrial production method of surface-modified polyamide fiber which has an excellent texture and is suitable for woven and knitted fabrics. In detail, the present invention has an object of providing an industrially extremely advantageous production method that can obtain a polyamide fiber having a good surface-roughening property even though it has good spinnability and does not undergo an elution and removal step.

[0007]

[Means for Solving the Problems] To achieve this object, the present inventor has conducted extensive studies and, as a result, added a certain amount of a hindered amine compound having a specific structure to a polyamide having a specific terminal group to prepare an aqueous emulsion oil solution. The present invention has been accomplished by finding an extremely interesting fact that irregularities are generated on the fiber surface when spinning is carried out by using. That is, the present invention provides the following formula (1)

(C · COOH) − (C · NH ₂ )> 30 (1)

[Wherein (C.COOH) and (C
-NH ₂ ) is the gram equivalent (g) of the respective terminal carboxyl groups and terminal amino groups per 10 ⁶ g of polyamide.
eq) represents the amount. ] To a polyamide satisfying the following general formula (2)

[0010]

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[Wherein R is a hydrogen atom and has 1 to 4 carbon atoms]
Represents an alkyl group or an alkoxy group having 1 to 8 carbon atoms. ] A composition containing 0.3 to 5 parts by weight of a hindered amine compound having one or two substituents in the molecule per 100 parts by weight of polyamide is melt-spun, and the discharged yarn is an aqueous emulsion. Is added to form irregularities due to protrusions of the polyamide itself on the surface of the fiber, thereby producing a roughened polyamide fiber.

Hereinafter, the present invention will be described in more detail. Examples of polyamides used in the present invention include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 46, nylon 11 and nylon 12. Further, these may be obtained by copolymerizing an aromatic component such as terephthalic acid or isophthalic acid or an aliphatic component such as polyethylene glycol. Nylon 6 is particularly preferably used.

The terminal group of polyamide generally has an amide group and a carboxy group, and the amount thereof is preferably an amount satisfying the following formula (1).

(C · COOH) − (C · NH ₂ )> 30 (1)

[Wherein (C.COOH) and (C
-NH ₂ ) is the gram equivalent (g) of the respective terminal carboxyl groups and terminal amino groups per 10 ⁶ g of polyamide.
eq) represents the amount. ] The effects of the present invention can be obtained with respect to the polyamide satisfying the above formula (1). Furthermore, (C ・ COOH)-(C ・ N
The larger the value of H ₂ ) is, the more preferable, and the effect is sufficiently exhibited. The (C · COOH) - maximum value of (C · NH ₂₎ is usually 200, preferably 150. On the other hand, if the lower limit of Expression (1) is not satisfied, it will be difficult to achieve the object of the present invention.

In the present invention, the hindered amine compound compounded in the polyamide is represented by the following general formula (2)

[0017]

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[Wherein, R is a hydrogen atom and has 1 to 4 carbon atoms]
Represents an alkyl group or an alkoxy group having 1 to 8 carbon atoms. ] It is a compound which has 1 or 2 substituents represented by this. As a specific example, the following formula (A)-
The compound represented by (H) is exemplified. Further, even hydrochlorides obtained by ionically bonding hydrochloric acid to the nitrogen atom of these compounds can be used in the same manner.

[0019]

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[0020]

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Further, the compounds (E) to (H) have an active chloro atom in the triazine ring, but they may be those further reacted with various amines. The amount of these hindered amine compounds compounded in the polyamide is 0.3 per 100 parts by weight of the polyamide.
-5 parts by weight, preferably 0.5-4 parts by weight. The hindered amine compound is a compound originally used for the purpose of photostabilization, and the photostabilization effect is sufficiently exhibited with a compounding amount usually less than 0.3 part by weight.

However, in order to obtain the surface-roughened polyamide fiber having surface irregularities according to the present invention, the compounding amount of 0.3 parts by weight or more is required. In the present invention, when the content of the hindered amine compound is 0.3 parts by weight or less, it is difficult to obtain the desired effect. On the other hand, if the blending amount exceeds 5 parts by weight, the effect corresponding to it cannot be obtained, which is economically disadvantageous, the yarn formability is deteriorated, and the yarn quality is also unsatisfactory.

In the present invention, in order to mix the hindered amine compound with the polyamide, the polyamide may be added in a powder form before melt-spinning, or a master pellet obtained by using a biaxial ruder or the like may be added. .
Further, it is possible to add the polyamide before the polymerization is completed. In addition, when blending the hindered amine compound with the polyamide, one kind of hindered amine compound may be used alone, or two or more kinds thereof may be used in combination.

The polyamide contains optional additives such as antistatic agents, anti-coloring agents, flame retardants, antioxidants, matting agents, organic pigments, dyes and glass fibers, if necessary. Good. The polyamide of the present invention may be melt-extruded and spun by a conventional method. The fibers spun here may have a normal round cross section, a modified cross section or a hollow cross section. For stretching, the spun fiber may be wound once and then separately stretched, or may be directly stretched after spinning and before winding.

In the present invention, it is important to use an aqueous emulsion as an oil agent for the obtained fiber. Even if a non-aqueous (straight) oil agent is adhered, the fiber surface is smooth and no change is observed. However, the use of an aqueous emulsion oil agent causes the surface to have irregularities. It can be considered that the formation of the unevenness is caused by the spherulites grown by the adhesion of water, because the unevenness is formed on the surface even when pure water is applied instead of the oil agent. Since the attachment of water is an important point, the non-aqueous (straight) oil agent may be attached after attaching the water.

The amount of the water-based emulsion oil agent attached can be freely changed within a range in which the yarn can be formed.
The range of 12% is preferable. The higher the EPU, the more easily irregularities are formed, but if the amount applied is too large, the wound fiber may stick, which is not desirable. To apply the oil agent, there is a method of applying the spun fiber before winding the fiber with an oiling roller, measuring oiling or the like, but the method is not limited per se.

[0027]

EXAMPLES Hereinafter, the method of the present invention will be specifically described with reference to examples. In the examples, the tests and measurement methods for evaluating the intrinsic viscosity, the amount of terminal groups, the concavo-convex forming property of the fiber surface, and the feel were performed according to the following explanations.

A. Intrinsic viscosity [η] polymer 0.2 g, 0.4 g, 0.8 g each 100 ml
Of m-cresol. Using an Oswald viscous tube, ηrel (t / t ₀ ) was measured at 35 ° C., ηrel-1 was plotted against each concentration C (g / 100 ml), and from the intercept of a straight line obtained from three points, [η ] Was asked.

B. Amount of Terminal Group The amount of terminal carboxyl group was determined by dissolving 0.1 g of the polymer in 5 ml of benzyl alcohol by heating and titrating with 0.1N sodium hydroxide. The amount of terminal amino group is the polymer
0.1 g was dissolved in 5 ml of m-cresol by heating to give 0.1
It was determined by titration with Np-toluenesulfonic acid.

C. Irregularity-forming property of fiber surface The fiber surface is observed using a scanning electron microscope,
Three levels depending on the height of the protrusion (◎: 0.4 μ or more, ○: 0.2
.About.0.4 μ, ×; 0.2 μ or less).

. [0031] d knitted fabric texture evaluation of feeling knitted fabric of skilled technicians functional test four levels of the surface texture evaluation by (◎; slime feeling completely without, Shari feeling is very strong, ○; Shari There is a feeling, △: the slimy feeling is stronger than the sharpness, ×: there is no great difference from the root product).

Example 1 The intrinsic viscosity [η] measured in m-cresol was 1.2.
1, the terminal carboxyl group amount is 85 grams equivalent / 10
⁶ g, 100 parts by weight of a nylon 6 polymer having an amount of terminal amino groups of 5 gram equivalent / 10 ⁶ and a hindered amine compound [2-chloro-4,6-bis (2 ′, 2) represented by the structural formula (E). 2.0 parts by weight of ', 6', 6'-tetramethyl-4'-aminopiperidyl) -1,3,5-triazine] were mixed and wound at a spinning temperature of 250 ° C. and a spinning speed of 600 m / min. . At this time, the amount of water-based emulsion oil added is 7.0%
It was applied using an oiling roller so that Subsequently, it was drawn at a draw ratio of 3.4 times to obtain a nylon 6 fiber of 65 denier / 24 filament.

The spinnability and drawability were both good. The nylon 6 fiber thus obtained is shown in FIG.
As shown in (electron micrograph), irregularities were confirmed on the fiber surface. Furthermore, when this multifilament was formed into a knitted fabric, it had an excellent texture with a crisp feeling, and the slimy feeling was completely eliminated. When the surface of nylon 6 fiber obtained in the same manner was observed by an electron microscope without adding any hindered amine compound, the size of the spherulites was about 0.1 μ, and the size of the unevenness of Example 1 was large. It was about 1/10 of that.

Examples 2 to 5, Comparative Examples 1 to 6 Using the nylon 6 polymer, hindered amine compound and oil agent shown in Table 1, spinning and drawing were carried out under the same conditions as in Example 1. Similarly, observation with an electron microscope was performed, and the texture on the knitted fabric was evaluated. The results are shown in Table 1.

[0035]

[Table 1]

[0036]

The roughened polyamide fiber obtained by the method of the present invention is not characterized in that it is formed by elution and erosion treatment or the like on its surface, but is characterized in that projections and depressions of the polymer itself are formed. are doing. The method of the present invention is
It does not require any post-treatment work such as elution and removal of the second component with respect to polyamide for forming irregularities as in the past, but melt-spinning and roughened polyamide fibers having irregularities on the fiber surface only by adding an aqueous oil agent It is significant in that it can be provided.

[Brief description of drawings]

FIG. 1 is an electron micrograph showing surface irregularities of a polyamide fiber obtained in Example 1.

Claims (1)

[Claims] 1. A formula (1) (C · COOH) - (C · NH 2)> 30 ··· (1) [ where Shikichu, (C · COOH) and (C · NH ₂₎
Represents the gram equivalent (g eq) amount of each terminal carboxyl group and terminal amino group per 10 ⁶ g of polyamide. To a polyamide satisfying the following general formula (2): [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 8 carbon atoms. ] A hindered amine compound having one or two substituents represented by the following formula in an amount of 0.3 to 5 per 100 parts by weight of polyamide.
A method for producing a roughened polyamide fiber, characterized in that the composition containing parts by weight is melt-spun, and the discharged yarn is provided with an aqueous emulsion to form irregularities due to protrusions of the polyamide itself on the fiber surface. .