JPH03220313A - Production of polyamide yarn - Google Patents

Abstract

PURPOSE:To obtain the title yarn useful as clothes, etc., having excellent color tone and productivity in spinning black spundyed polyamide containing carbon black, by using a polyamide containing a given amount of fatty acid amide. CONSTITUTION:In spinning black spun dyed polyamide (e.g. nylon 6) containing preferably 0.9-1.5wt.% based on polyamide of carbon black having <=20mmu primary particle diameters, the polyamide containing >=0.05wt.%, preferably 0.1-1.0wt.% based on the polyamide of a fatty acid amide (e.g. ethylenebisstearic acid amide) is used to give the objective yarn.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for producing polyamide fibers that facilitates the production of black spun-dyed polyamide fibers.

<Prior art> In the production of black spun-dyed polyamide fibers containing carbon black, carbon black and ordinary polyamide chips are blended, melt-spun and stretched, or a polyamide master containing a high concentration of carbon black is used. A method is adopted in which the chips are blended with ordinary polyamide chips, and then melt-spun and stretched.

By the way, what is important in the production of black spun-dyed yarn is how to increase the blackness of the yarn, and for this purpose it is necessary to use carbon particles with a primary particle diameter of 20 mμ or less. However, when melt-spinning is performed using such carbon particles, fine fibers used for clothing with a single thread diameter of 4 de or less frequently break during drawing, resulting in thin fibers for clothing that have a jet black tone. Denier black spun-dyed polyamide 111i was not produced industrially.

On the other hand, if carbon having a large particle diameter of 25 mμ or more is used, the above-mentioned problems are unlikely to occur, and no major problems occur during melt spinning. However, due to the large particle size, only black spun-dyed polyamide fibers with a reddish color could be obtained.

<Objective of the Invention> The object of the present invention is to provide a method for producing polyamide tl+H containing carbon black having a primary particle diameter of 20 mμ or less and capable of producing jet black spun-dyed yarn.

In the course of intensive study to achieve the above object, the present inventors found that carbon black with a small particle size had some oxidized and activated parts, which caused the amide bonds of polyamide to be activated. Carbon black interacts with carbon black end groups to form a polyamide melt with a high concentration of carbon black in some parts, and this high concentration part is spun without being loosened. Assuming that single filament breakage occurs during stretching in areas where the black concentration is high, further studies led to the completion of the present invention.

Thus, according to the present invention, when spinning a black spun-dyed polyamide fiber containing carbon black having a primary particle size of 20 mμ or less, a polyamide containing 0.05% by weight or more of fatty acid amide based on the weight of the polyamide is used. A polyamide characterized by the use of! A method of manufacturing miscellaneous products is provided.

In the present invention, the polyamide used as a contrast in terms of spun-dyed yarn structure may be general-purpose polyamides such as nylon 6, nylon 66, and nylon 12, copolymers thereof, or mixtures thereof. Other modifiers such as heat stabilizers and antistatic agents may be added to these polymers.

On the other hand, the carbon black used in the present invention has a primary particle diameter of 20 mμ or less, and is commonly used as color black for color channels, color furnaces, etc.

In the present invention, fatty acid amide refers to stearic acid amide, palmitic acid amide, methylene bis stearamide, ethylene bis stearamide, etc., which are generally known as lubricants.
Amides are preferably employed.

In the present invention, examples of methods for producing spun-dyed polyamide fibers using polyamide containing carbon black and fatty acid amide include the following method.

(1) After weighing the desired amount of carbon black, fatty acid amide and polyamide, blend these and
Melt in an extruder to create a mixed polymer,
Subsequently, it is discharged as a thread from the spinneret, taken off, and then drawn.

(2) A desired amount of carbon black and fatty acid amide are weighed and blended with a small amount of polyamide to create a master chip, and then the carbon black is blended with polyamide chips to the desired content and melt-spun and stretched.

(3) A master chip consisting of a desired amount of carbon black and a small amount of polyamide is blended with fatty acid amide and polyamide chips at a desired ratio, and then melt-spun and drawn.

It goes without saying that other additives, binders, etc. may be mixed therein as necessary, and a mixture may be used. Further, the material may be once wound up by melt spinning and then stretched, or these steps may be made continuous.

In the present invention, the amount of carbon black contained in the polyamide fiber is generally 0.7% by weight, preferably 0.9% by weight or more based on the polyamide, although it depends on the thickness of the single filament. However, since no difference in hue is observed even if the amount exceeds 1.5% by weight, it is appropriate that the amount is 1.5% by weight or less.

Furthermore, the content of fatty acid amide is the amount required to inhibit the interaction between carbon black and polyamide molecular chains, and is usually 0.00% relative to the polyamide.
0.5% by weight, preferably 0.1% by weight or more. Of course, even if this amount is excessive, there is no particular harm, but generally 1
% or less is a practically preferable range.

In addition to fatty acid amides, paraffin, wax, higher fatty acids, monoglycerin esters, higher fatty acid alcohols, and metal soaps are generally used as lubricants for polymer molding, but these are used as internal lubricants. It improves the fluidity (viscosity) of the polymer or acts as an external lubricant to reduce the boundary friction between the mold and the polymer.

Therefore, even if a lubricant exhibiting such behavior is applied to the present invention, it will not be possible to improve the fluidity of a polyamide melt containing a high concentration of carbon black, or to form areas where carbon black has aggregated at a high concentration. No effect has been found to prevent this.

Incidentally, JP-A-63-92717 discloses the combined use of a yellow isoindolinone pigment and a metal stearate in the presence of a dispersion medium.

However, when fatty acid amide is used as in the present invention, it has been confirmed that there is no part where carbon black is highly concentrated, or even if it is present, it is easily loosened by weak shearing force. Ta.

Although fatty acid amide naturally has the above-mentioned function as a lubricant, this function as a lubricant is not relevant to the purpose of the present invention. Considering its chemical structure, it has good (chemical) compatibility with polyamide, and its action of inhibiting the interaction between the activated portion of carbon black and the polyamide molecular chain achieves the object of the present invention. It can be assumed that there are.

In the present invention, as mentioned above, by mixing 0.05% by weight or more of fatty acid amide, which is considered to inhibit the chemical interaction between fine particle carbon black and polyamide, the carbon concentration in the polyamide melt can be reduced. It is possible to prevent parts from forming, or even if they do occur, to unravel them with a weak shearing force, and there is no single filament breakage during stretching of polyamide black spun-dyed fibers mixed with carbon black, which produces a jet black color due to the fine particles. It was successfully possible to produce it industrially.

<Example> Hereinafter, the present invention will be explained by examples.

Example-1 Color furnace carbon (manufactured by Mitsubishi Kasei, RAM (F) 5
085 black, particle size 15-20TrLμ) 1.15
1 part and 0.3 part of ethylene bis stearylamide were mixed, and then put into an extruder-type melt spinning machine, and spun and drawn by a conventional method (spinning speed: 5oon/min, stretching ratio: 3.44 times) to 70 de/min. A drawn yarn of 24 f was obtained. The color was jet black. In this case, 100K
The rate of single yarn breakage per gram was only 1.7 times, which caused no operational problems, and even when observed with a transmission microscope, no areas with high carbon concentration were found.

On the other hand, in the above example, when spinning and drawing was carried out under the same conditions without mixing ethylene bis stearylamide, the result was 100%
Single yarn breakage occurs at a frequency of 20 times per kg, and when the constituent single yarns are observed with a transmission microscope, there are parts that seem to be due to extremely high carbon concentration, that is, pitch black parts that do not transmit any light at 22 times per 50α. 8. There were 8 areas where the concentration seemed to be slightly biased (high).

and nylon 6 chips with a nominal viscosity of 1.34 were blended so that the carbon concentration was 1.2% by weight, and the blended chips were mixed with various addition ratios of ethylene bis stearylamide. Spinning and drawing were carried out under the following conditions.

The results of examining the number of single filament breakages per 100 kg and the number per 50α of portions where the carbon concentration of the component filament single yarns is extremely high and slightly high are shown in the table below.

In the case of the present invention, there were almost no single yarn breakages and unseparated portions of carbon with an extremely high carbon concentration, and it was confirmed that there were no problems in production.

Example-2 The carbon used in Example-1 was blended with nylon 6 chips with an intrinsic viscosity of 0.81 to a weight percentage of 15%, kneaded with a twin-screw extruder, and discharged to create a master chip. did. This master chip was used 18 times and 21 times, respectively, and could not be applied to operational production.

Comparative Example 1 In Example 1, magnesium stearate and microcrystalline wax were separately mixed at 0.5% by weight in place of ethylene bisstearylamide and spun and drawn. 3 Mix 20 parts by weight of ethylene bis stearylamide with 100 parts of the carbon used in Example-1, blend it with nylon 6 chips with an intrinsic viscosity of 0.8, and knead with a twin-screw extruder to obtain a carbon concentration of 15%. A master chip containing 3% ethylene bisstearylamide was prepared. This master chip and nylon 6 chips with an intrinsic viscosity of 1.34 were blended so that the carbon concentration was 1.2% by weight (ethylene bisstearylamide 0.2% by weight), and the mixture was spun and drawn under the conditions of Example-1. Did. The frequency of single yarn breakage per 100 kg was 0.5 times, and there were no problems in operation.

Claims (1)

[Claims] A polyamide fiber characterized by using a polyamide containing fatty acid amide in an amount of 0.05% by weight or more based on the weight of the polyamide when spinning a black spun-dyed polyamide fiber containing carbon black having a primary particle size of 20 mμ or less. Production method.