JP2001172864A - Method for producing wholly aromatic polyamide having excellent fastness to light - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a wholly aromatic polyamide yarn having excellent fastness to light and excellent clear color in dyeing. SOLUTION: This method for producing a wholly aromatic polyamide having excellent fastness to light is characterized in that a wholly aromatic polyamide yarn always maintaining >=15% water content is heat-treated in an aqueous solution of a tertiary and/or quaternary amine-containing organic compound having pH 6-10.

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 wholly aromatic polyamide fiber having improved light fastness and a wholly aromatic polyamide fiber obtained by the method.

[0002]

2. Description of the Related Art Wholly aromatic polyamide fibers are synthetic fibers that combine high functionality such as high strength, high elastic modulus, high heat resistance, non-conductivity, and rust resistance with the flexibility and lightness of organic fibers. . Due to these features, they are used as industrial materials such as automobile tires, automobile conduction belts, conveyors, and optical fiber reinforcement.

[0003] On the other hand, as a clothing use or a textile product, it is used for work gloves, work clothes, sports clothes, etc., which apply the hardness of cutting to a knife. In addition, it has a limiting oxygen index of 29 and is inherently hard to burn and carbonizes without melting or shrinking at a high temperature of 500 ° C. And its development as a product.

[0004] The wholly aromatic polyamide fiber has a pale yellow color, but turns brown when exposed to ultraviolet light. Ultraviolet rays are contained in a large amount in sunlight, and when the wholly aromatic polyamide fiber is exposed to the outdoors, the color changes to light brown in a few hours. Ultraviolet rays are also included in daylight shades and in the light of incandescent and fluorescent lights. It is a big problem at the stage. In particular, when a wholly aromatic polyamide fiber is applied to clothing or interior products, the problem of discoloration due to ultraviolet rays is large.

[0005] In response, various methods have been proposed. For example, a method of coating a wholly aromatic polyamide fiber with another fiber (Japanese Unexamined Patent Publication No. 3-830) or a method of attaching a polyethyleneimine compound to a wholly aromatic polyamide fiber and then performing a heat treatment (Japanese Patent Laid-Open No. 01-174680). Gazette)
However, in the former, it is difficult to completely coat, and it is considered that characteristics such as heat resistance of the wholly aromatic polyamide are impaired. In the latter, the flexibility of the fiber is impaired because the fiber surface is processed with resin.

Japanese Patent Application Laid-Open No. 62-97967 proposes a method of treating wholly aromatic polyamide fibers with an aqueous solution of metal hypochlorite. Further, a method of treating with an aqueous solution of an oxidizing agent such as sodium hypochlorite or sodium chlorite has been proposed, but these methods all change the original hue of the wholly aromatic polyamide fiber to brown, so that clothing is The initial hues are poor for utility and interior products and are not a complete solution.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a wholly aromatic polyamide having improved light fastness without changing the initial hue.

[0008]

In order to achieve the above object, the present invention employs the following means. (1) Heat resistance of a wholly aromatic polyamide fiber whose water content is always maintained at 15% or more in an aqueous solution having a pH of 6 to 10 to which an organic compound containing a tertiary and / or quaternary amine is added. A method for producing wholly aromatic polyamide having excellent fastness. (2) The production method according to the above (1), wherein the amount of the organic compound containing a tertiary and / or quaternary amine is 0.5 g / l to 10 g / l. (3) Organic compounds containing a tertiary amine and / or a quaternary amine are trade names "Gasguard" CFN (manufactured by Meisei Chemical Co., Ltd.), "Nikkahibitor" S220 (manufactured by Nika Chemical Co., Ltd.), "Neohibitor" MF, TH (manufactured by One Company), "Anti-Fume" K2, K2 (Satoda Kako), "Inhibitor Morin" P4NN (Morin Chemical Industries), "
Gasnon “MYS” (Senka), “Map Assist”
The production method according to the above (1), which is selected from GS and CL (manufactured by Morirokusha). (4) A wholly aromatic polyamide excellent in light fastness obtained by the method according to any one of the above (1) to (3).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The wholly aromatic polyamide fibers used in the present invention include para-based wholly aromatic polyamides such as polyparaphenylene terephthalamide.

[0010] The fiber in the present invention is a concept including a filament, a staple fiber, a sliver, a top, a spun yarn, a nonwoven fabric, a woven fabric and a knitted fabric.

The para-based wholly aromatic polyamide fiber is formed by heating and dissolving a polyparaphenylene terephthalamide resin in concentrated sulfuric acid and spinning it into a basic aqueous solution. The moisture percentage can be adjusted.

In the present invention, it is necessary to keep the water content in the fiber at 15% or more. That is, it is necessary to prevent the water content from passing through a state of less than 15% after spinning. By doing so, it is believed that the crystallization of the fiber surface can be slowed down, and that the additive can be inserted into the yarn by subsequent processing. In particular, by heating a tertiary and / or quaternary amine-containing organic compound and a wholly aromatic polyamide fiber in an aqueous solution, the organic compound can be inserted into the fiber, and the effect of the compound can be exhibited. Is done. In particular, when dyeing a wholly aromatic polyamide fiber using an organic dye, an organic compound containing a tertiary and / or quaternary amine is used in combination to improve the light fastness of the dyed wholly aromatic polyamide fiber. be able to.

The addition amount of the tertiary and / or quaternary amine-containing organic compound is effective when it is 0.5 g / l to 10.0 g, but is preferably 1 to 5 g / l.

Examples of this compound include "Gasguard" CFN (manufactured by Meisei Chemical Co., Ltd.) and "Nikkahibitor" S2
20 (manufactured by Nikka Chemical Co., Ltd.), "Neohibitor" MF, TH
(Manufactured by one company), "Anti-fume" K2, K25 (Satoda Chemical), "Inhibitor Morin" P4NN (Morin Chemical), "Gasnon" MYS (Senka), "Map Assist" GS, CL (Moriroku) Co., Ltd.), but a similar compound may be synthesized and used.

The pH of the treatment aqueous solution is maintained at 6 to 10, preferably 7 to 9.

[0016]

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

Polyphenylene terephthalamide (intrinsic viscosity = 6.5) obtained by a usual method is dissolved in 99.9% of concentrated sulfuric acid to form a spinning dope having a polymer concentration of 19.9% and a temperature of 80 ° C., and a pore diameter of 0.01 mm. After spinning out into the air for a short time from a die having 1000 pores, the mixture is guided into water at 4 ° C. to solidify, guided to a Nelson roller, neutralized with an 8% aqueous sodium hydroxide solution, washed with water, and then washed with a hot roller. And dried at 100 ° C. for 15 seconds, and passed through a plastic tube without interruption to obtain a para-based wholly aromatic polyamide fiber having a total fineness of 1670 dtex (equivalent to absolute dryness) comprising 1,000 filaments. The water content of the fiber was 40%.

A treatment was performed using this fiber.

In measuring the pH, a digital pH meter HM-60V (Toa Denpa Kogyo KK) was used. Comparative Example 1 The wholly aromatic polyamide fiber was LABOMAT BFA
Treatment was carried out using a dyeing machine (manufactured by Warner Mathis Co., Ltd.) under the following condition (A). (A) Sodium acetate 5.0 g / l pH 8.04 Liquid ratio 1:20 Processing temperature 100 ° C. Processing time 40 minutes Comparative Example 2 The above wholly aromatic polyamide fiber was LABOMAT BFA
Treatment was carried out using a dyeing machine (manufactured by Warner Mathis Co., Ltd.) under the following condition (B). (B) Dye (CIBASIC YELLOW21) 3% owf Sodium acetate 5.0 g / l pH 7.70 Liquid ratio 1:20 Dyeing temperature 120 ° C. Dyeing time 40 minutes Example 1 The above wholly aromatic polyamide fiber was LABOMAT BFA
Using a dyeing machine (manufactured by Warner Mathis Co., Ltd.), treatment was performed under the following condition (C). (C) “Gasguard” CFN 4% owf Sodium acetate 5.0 g / l pH 8.38 Liquid ratio 1:20 Treatment temperature 100 ° C. Treatment time 40 minutes Example 2 The above wholly aromatic polyamide fiber was LABOMAT BFA
Using a dyeing machine (manufactured by Warner Mathis Co., Ltd.), treatment was performed under the following condition (D). (D) "Gasguard" CFN 4% owf dye (CIBASIC YELLOW 21) 3% owf sodium acetate 5.0 g / l pH 7.80 Liquid ratio 1:20 Dyeing temperature 120 ° C Dyeing time 40 minutes After the treatment, hot water and water are added. After sufficient rinsing with the use of a centrifugal dehydrator, the product was dehydrated and dried at 130 ° C. These treated fibers were evaluated with the naked eye to determine the sharpness of the color.
Δ, ×. ○ indicates that the sharpness is good, や indicates that the sharpness is slightly inferior, and X indicates darkening.

When measuring the light fastness, JIS L
0842 (testing method for color fastness to carbon arc lamp). Judgment was made by exposing until the blue scale 3 was standardly faded, and measuring the color difference ΔE before and after the exposure. Here, ΔE is the color difference Δ in the L, a, b color system according to the display method of JIS Z 8730 color−the color difference of the object color.
It was expressed by E.

A sample having a low value of ΔE has excellent light resistance.

The results are summarized in Table 1.

[0023]

[Table 1]

[0024]

The wholly aromatic polyamide fiber obtained according to the present invention has excellent light fastness and excellent color clarity when dyed.

Claims (4)

[Claims] 1. A heat treatment of a wholly aromatic polyamide fiber whose water content is always maintained at 15% or more in an aqueous solution having a pH of 6 to 10 to which an organic compound containing a tertiary and / or quaternary amine is added. A method for producing a wholly aromatic polyamide excellent in light fastness. 2. The method according to claim 1, wherein the amount of the organic compound containing a tertiary and / or quaternary amine is 0.5 g / l to 10 g / l. 3. Organic compounds containing a tertiary amine and / or a quaternary amine are trade names "Gasguard" CFN (manufactured by Meisei Chemical Co., Ltd.), "Nikkahibitor" S220 (manufactured by Nikka Chemical Co., Ltd.), and "Neohibitor". MF, TH (manufactured by one company), “Anti-fume” K2, K2 (Satoda Kako), “Inhibitor Morin” P4NN (Morin Chemical Industry), “
Gasnon “MYS” (Senka), “Map Assist”
2. The method according to claim 1, wherein the method is selected from GS and CL (manufactured by Morirokusha). 4. A wholly aromatic polyamide having excellent light fastness obtained by the method according to claim 1.