JPH01292178A - Yellowing preventing treatment of polyamide yarn - Google Patents

Abstract

PURPOSE:To prevent yellowing of polyamide yarn, by treating polyamide yarn with a treating solution, in an acidic range, comprising an unsaturated carboxylic acid polymer containing carboxyl group, etc., and having >=a specific molecular weight. CONSTITUTION:Polyamide yarn is processed with a treating agent consisting essentially of an unsaturated carboxylic acid polymer containing carboxyl group and/or carboxyl group neutralized into a salt form and having >=10,000 molecular weight at pH2-4, for example, by immersion method preferably at 20-90 deg.C. Polyacrylic acid, polymethacrylic acid, poly alpha-hydroxyacrylic acid and alkaline metallic salts thereof may be cited as the polymer. By this method, yellowing of polyamide yarn with nitrogen oxide gas in atmosphere is prevented without damaging dyeability.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for preventing yellowing of polyamide fibers.

(Prior Art) It is known that a drawback of polyamide fibers is that nitrogen oxide gas in the atmosphere reacts with the terminal amino groups of the polyamide fibers, resulting in yellowing. Conventionally, as a solution to this problem, a method has been proposed in which the terminal amino groups of polyamide fibers are blocked.

For example, as shown in Japanese Patent Publication No. 49-29917, the terminal amino groups of polyamide IXM are blocked by both covalent bonds and sulfonic acid groups, and Japanese Patent Publication No. 55-47150 discloses In this way, a colorless compound having no covalent bonding group and having an anionic active group consisting of a sulfonic acid group or a sulfuric acid ester group is adsorbed onto polyamide fiber in an amount of 4 to 40 μmol/ff fiber, and the terminal amino acid on the surface of the polyamide fiber is absorbed. There is a method of blocking only the base.

[Problem that the invention seeks to solve]

In the above technology, as shown in Japanese Patent Publication No. 49-29917, in order to block the terminal amine groups of polyamide fibers by covalent bonds, a fixing treatment is required, making the operation complicated; It is well known that there is a drawback that dyeability is reduced due to blocking of amine groups.

In addition, as shown in Japanese Patent Publication No. 55-47150, in a method in which a colorless compound consisting of a sulfonic acid group or a sulfuric ester group without a covalent bond group is adsorbed onto polyamide fibers, depending on the treatment method such as dipping treatment, foaming may occur in the fabric. There is a risk that the particles will rise and machining becomes difficult. In general, its purpose is to prevent yellowing caused by the interaction between the polyamide fibers packed in the paper material and the paper material, and prevent yellowing when exposed to pollutant gases in the atmosphere. Not targeted. Furthermore, when dyeing fibers that have undergone anti-yellowing treatment, it is necessary to treat them in an alkaline bath to remove the anti-yellowing agent, which makes the operation complicated, and it is difficult to completely replace the fibers with acidic dyes that have high affinity. However, there is also a risk that the saturation will decrease. As described above, the conventional technology has other problems associated with anti-yellowing treatment, and the anti-yellowing effect cannot be said to be sufficient. Currently, yellowing due to contaminated gas is prevented mainly by sealing with packaging, and improvements to the conventional technology are desired.

Therefore, an object of the present invention is to provide an anti-yellowing treatment method that has a large anti-yellowing effect and is free from problems in processing and dyeing.

[Means for solving problems]

The present invention achieves the above object by treating polyamide fibers with a treatment agent having a pH of 2 to This is a method for preventing yellowing of polyamide fibers, which is characterized by carrying out the treatment in step 4.

Polyamide fibers to which the method of the present invention can be applied include all fibers having an amide bond such as nylon 6 and nylon 6.6, as well as yarns, woven fabrics, knitted fabrics, etc. containing the fibers.

The carboxyl group-containing polymer used in the present invention is
It is a homopolymer or copolymer of an unsaturated carboxylic acid, a copolymer of an unsaturated carboxylic acid and an ethylenically unsaturated polymer, or a mixture thereof. The molecular weight of the polymer is 1
It needs to be 0000 or more. Also, aooo
If it exceeds oo, it becomes difficult to process, which is not preferable. The copolymer of unsaturated carboxylic acid and ethylenically unsaturated polymer preferably contains 20% by weight or more of unsaturated carboxylic acid. Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, crotonic acid, oleic acid, cinnamic acid, maleic acid, fumaric acid, citraconic acid, and mesaconic acid. Examples of ethylenically unsaturated polymers include ethylene, propylene, butylene, vinyl acetate, vinyl alcohol acrylonitrile, vinyl chloride, and vinylidene chloride. Preferred polymers are polyacrylic acid, polymethacrylic acid, polyα-
Hydroxyacrylic acid or an alkali metal salt thereof. Further, these may form neutralized salts, and preferred salts are sodium salts.

Although a dipping method is usually applied to the treatment method of the present invention, other suitable methods such as a padding method and a printing method can also be applied.

In the application of the present invention, when using the dipping method, the concentration of the polymer containing the carboxyl group in the treatment agent is 0.0
1-30 weight%, preferably 0.05-10% by weight, and the treatment temperature is 0-110°C, preferably 20-110°C.
The temperature is 90°C. The treatment time varies depending on the polymer concentration and the 9°C of the treatment bath, but is generally about several minutes to 60 minutes. The treatment bath is preferably on the acidic side, especially at pH 2-
A range of 4 is preferred. The PTL of the treatment bath can be adjusted with formic acid, phosphoric acid, etc. when using an alkali metal salt of a polymer containing a carboxyl group. When carrying out the present invention by a method other than the dipping method, the amount of polymer containing a carboxyl group can be easily determined in accordance with the dipping method described above.

According to the present invention, it is also possible to simultaneously perform anti-yellowing treatment and dyeing on polyamide fibers by coexisting a treatment agent and a dye.

Example 1 and Comparative Example 1 A half tricot knitted fabric of 6-filament nylon yarn that had been subjected to a conventional scouring process was subjected to a dipping treatment under the following conditions.

Sodium polymethacrylate (approximately 75,000 molecules) 29/,
1! Gir! 1 (ao%) 2g
/l bath ratio 1:30 temperature 80℃ time
pH 2.6 for 60 minutes On the other hand, as a comparative example, treatment was carried out under the same conditions as above except that sodium polymethacrylate was omitted. The degree of yellowing of the treated product was determined by the following formula according to the nitrogen oxide gas test of JIS-L-0855.

Yellowing degree = <b value after M nitrogen gas test) - (b* value before nitrogen oxide gas test) The b1 value in the formula is determined by measuring the treated product with a spectrophotometer and
-Z-8729 L, a depending on the object color display method
.

This is the value obtained for b.

Table 1 shows the yellowing degrees of the present invention and comparative examples.

From Table 1, it can be seen that the degree of yellowing according to the examples of the present invention is small, and the degree of yellowing according to the comparative example is very large.

The amount of the present invention product and the comparative example were Aminyl Blue E-2GL.
(Manufactured by Sumitomo Chemical Co., Ltd., acid dye) 0.5% owf
The dyeing was carried out in separate baths at (1) 40°C (2) 60°C (3) and 80°C for 30 minutes, respectively. Dyeing L
, a and b are shown in Table 2.

From the above results, in the comparative example, the dye was already sufficiently dyed at 40°C, but in the present invention, the dyeing was slight at 40°C, and the dyeing increased sufficiently as the dyeing temperature rose. It is understood that the binding force between the treatment agent of the present invention and the amino groups of polyamide fibers is not large and does not inhibit dyeing.

Example 2 and Comparative Examples 2-1 to 2-3 The same nylon half tricot knitted fabric as in Example 1 was subjected to simultaneous yellowing prevention and dyeing treatment under the following conditions using a jet dyeing machine.

Sodium polyacrylate (approximately 500,000 between molecules> 2 g/fl Cibaset Turkis Blue G (disperse dye manufactured by Ciba Geigy) 0.015%ow
f Shiba Set Pink YLN (disperse dye manufactured by Ciba Geigy) 0.008 1/
Formic acid (80%) 2g/J! Bath ratio 1:30 temperature
80℃ time
pH 2.9 for 30 minutes On the other hand, as Comparative Example 2-1, treatment was performed under the same conditions as above except that sodium polyacrylate was omitted. Comparative Example 2-2: Sodium salt of lauryl sulfate (described in Japanese Patent Publication No. 55-47150) 0.0
79/ρ was treated as Comparative Example 2-3 under the same conditions as above except that 0.7 g/l of sodium salt of lauryl sulfate ester was added to Comparative Example 2-1. In Example 2 and Comparative Example 2-1.2-2, there was no problem due to foaming during processing, but in Comparative Example 2-3, the fabric rose due to foaming and the fabric drive part of the jet dyeing machine idled. A phenomenon was observed.

Table 3 shows l, a, b and the degree of yellowing determined in the same manner as in Example 1 for the nylon half tricot knitted fabrics treated and dyed in Example 2 and Comparative Example 2-1.2-2.2-3.

From the above results, L 1a of Example 2, in which yellowing prevention effect and dyeing were performed at the same time, and Comparative Example 2-1, in which only yellowing was performed.
, b, the color difference is slight, and it can be seen that according to the present invention, it is fully possible to perform yellowing prevention treatment and dyeing at the same time. Looking at the degree of yellowing, Comparative Example 2-1.2
-2.2-3, it can be seen that the degree of yellowing in Example 2 is small and the effect of the yellowing prevention treatment is fully exhibited.

In Comparative Example 2-2, the degree of yellowing was large and a beam with yellowing prevention effect was not obtained. In Comparative Example 2-3, since the anti-yellowing effect was not obtained in Comparative Example 2-2, an attempt was made to increase the concentration of lauryl Wt acid ester salt, but this resulted in processing problems due to foaming. In addition, the yellowing prevention effect was not great.

Example 3 and Comparative Example 3 For the same nylon half tricot knitted fabric as in Example 1,
Simultaneous treatment of yellowing prevention and fluorescent whitening was carried out under the following conditions using a jet dyeing machine.

Sodium polymethacrylate (molecular 0 approx. 300,000) 2 g/l Kayaphor Nu (manufactured by Nippon Kayaku Co., Ltd., fluorescent dye) 1% owf formic acid (
80%) 2g/N bath ratio
1:30 temperature
90℃ time
60 minutes ptl
2.7 On the other hand, as a comparative example, processing was carried out under the same conditions as above except that sodium polymethacrylate was omitted. The treated product was prepared in the same manner as in Example 1.
1a, b'' and yellowing degree were determined and shown in Table 4.

From the above results, L
, a , and b , the color difference is slight, and it is found that it is sufficiently possible to simultaneously perform yellowing prevention and fluorescent whitening treatments. Looking at the yellowing degree, the yellowing degree of Example 3 was lower than that of Comparative Example 3, and it can be seen that the effect of the yellowing prevention treatment was fully exhibited.

Example 4 and Comparative Example 4 The same nylon half tricot knitted fabric as in Example 1 was subjected to simultaneous yellowing prevention and dyeing treatment using a jet dyeing machine under the following conditions.

Sodium polymethacrylate (approximately 75,000 between molecules> 2 g/l Kayanol Brilliant Blue 2RW (manufactured by Nippon Kayaku Co., Ltd., acid dye) 1% owf Ultra MT-ST (manufactured by Mitejima Kagaku Co., Ltd., dyeing acid> 29 /J bath ratio
1:30 temperature
90℃ time
30 minutes pH 2.8 On the other hand, as a comparative example, treatment was carried out under the same conditions as above except that sodium polymethacrylate was omitted. the result,
In both Examples and Comparative Examples, the dye exhaustion rate was 98% or more, and the dyeability was not impaired by the anti-yellowing treatment agent.

Example 5 and Comparative Example 5 The same nylon half tricot knitted fabric as in Example 1 was subjected to a dipping treatment under the following conditions.

25% polyacrylic acid solution (manufactured by Wako Pure Chemical Industries, Ltd., viscosity 12.000 cp/30°C > 3 g/
l bath ratio 1:30 temperature
80℃ time
60 minutes at pH 3. On the other hand, as a comparative example, treatment was carried out under the same conditions as above except that polyacrylic acid was omitted. The degree of yellowing of the treated products was determined in the same manner as in Example 1 and is shown in Table 5.

Examples 6-1 to 6-3 and Comparative Examples 6-1 to 6-3 Nylon half tricot knitted fabrics using nylon-6 filament yarn were subjected to normal scouring and bleaching treatment, and then immersion treatment under the following conditions. .

Treatment method Sodium methacrylate (molecular weight 75,000>3 g/,
11 bath ratio 1:30 temperature
90℃ time
However, the pH value of the treatment liquid was adjusted as shown in Table 6 using the following pH adjuster.

pH adjuster example 6-1 sulfuric acid 6-2 formic acid 6-3 acetic acid comparative example 6-1 anhydrous mirabilite! / 6-2 Anhydrous Sodium Carbonate 6-3 The yellowing degree of the nylon half tricot knitted fabrics treated with sodium hydroxide was determined in the same manner as in Example 1 and is shown in Table 6.

From the above results, when the treatment is performed on the acidic side,
It can be seen that a good yellowing prevention effect can be obtained.

According to the method of the present invention, as is clear from the results shown in the examples above, an excellent effect of preventing yellowing caused by nitrogen oxide gas and the like in the atmosphere can be obtained. This is understood to be due to the carboxyl group bonding to the amino terminal group of the polyamide fiber.

In dyeing after anti-yellowing treatment, as shown in the examples, the dyeing increases as the temperature rises, and as a result, dyeing is possible without damaging the dyeing. Simultaneous treatment of yellowing prevention and dyeing can also be achieved without impairing dyeability.

The foaming property is also thought to be due to the structural characteristics of the polymer containing carboxyl groups, but the foaming property was small and there were no problems during the dipping treatment.

Claims (1)

[Claims] 1. Polyamide fibers are treated at pH 2 to 4 using a treatment agent whose main component is an unsaturated carboxylic acid polymer having a molecular weight of 10,000 or more and containing carboxyl groups and/or carboxyl groups neutralized in the salt form. 1. A method for preventing yellowing of polyamide fibers. 2. The method for preventing yellowing of polyamide fibers according to claim 1, wherein the polymer is polyacrylic acid, polymethacrylic acid, polyα-hydroxyacrylic acid, or an alkali metal salt thereof.