JPS621021B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for improving the dyeability of aromatic polyamide fibers dyed with cationic dyes, and more particularly to a method for improving wet fastness or rub fastness. Linear polyamides such as nylon 6, nylon 66, nylon 610, and nylon 11 have flexible molecular chains and good dyeability, but polyamides with aliphatic rings, aromatic rings, or heterocycles introduced into the molecule have poor heat resistance. It is strong, has excellent elasticity, morphological stability, etc., and is hydrophobic, but its molecular chains are rigid and highly crystalline, making it difficult to dye. Among these, fully aromatic polyamides have particularly excellent heat resistance and shape stability.
Because the molecular chains are more rigid and the structure is denser, it is much more difficult to dye than other ring-introduced polyamides, and often cannot be dyed at all. Currently, the dyeing of aromatic polyamides is generally a very complicated method of high-pressure dyeing using large amounts of special swelling agents (carriers), and improvements are needed in the working environment and wastewater due to the toxicity and odor of the special swelling agents. It is rare. Therefore, for the purpose of improving the dyeability, a method has been developed to copolymerize diamines or dicarboxylic acid halides that have functional groups that have affinity with dyes, and introduce these functional groups into the aromatic polyamide chains to improve the dyeability. be. These aromatic polyamides are generally dyed with cationic dyes or acid dyes from the viewpoint of dyeability and color fastness, especially sunlight fastness. In the case of acidic dyes, wet fastness is particularly poor, and it is known to perform post-treatment with a fixing agent such as tannic acid, syntanic acid, or polyamine in order to improve the wet fastness of dyed products. However, these known methods do not have sufficient effects on improving color fastness, or have a negative effect on sunlight fastness, etc., so that satisfactory color fastness cannot be obtained. On the other hand, methods for improving color fastness with cationic dyes are not generally known, and undyed dyes remaining on the fiber surface are decomposed or washed using reducing agents or washing, but these methods do not improve color fastness. The effect of improving durability is insufficient, and the fastness to rubbing and fastness to wetness are particularly poor. The present inventors have conducted extensive research into a method for improving the color fastness of aromatic polyamide fibers dyed with cationic dyes, solving the drawbacks of conventional methods and providing excellent wet fastness and rubbing fastness.
The method of the present invention has been arrived at. That is, the present invention is characterized in that, during post-dyeing treatment of aromatic polyamide fibers dyed with cationic dyes, the fibers are treated with hot water using a treatment liquid containing at least an anionic surfactant or an oxidizing agent. The method of the present invention provides significantly superior wet fastness and abrasion fastness with simple processing steps compared to conventional methods, and also improves hue, texture, and
It is characterized by having no adverse effect on sunlight fastness. The reason why excellent color fastness is obtained by the method of the present invention is not clear, but the anionic surfactant acts to cause the undyed cationic dye on the fiber surface to flow out into the dye liquor. This is thought to be because the undyed cationic dye that has flowed out is decomposed by the oxidizing agent present in the dye solution. The aromatic polyamide braided fibers targeted for the method of the present invention include aromatic dicarboxylic acids, aromatic diamines and/or
Or it is a fiber made of polyamide condensed with aromatic aminocarboxylic acid. The dicarboxylic acid component of the polyamide includes residues such as isophthalic acid and terephthalic acid, the diamine component includes residues such as metaphenylenediamine and paraphenylenediamine, and the aminocarboxylic acid component includes residues such as para-aminobenzoic acid and meta-aminobenzoic acid. is exemplified. Such aromatic polyamide fibers are usually produced by condensing an aromatic dicarboxylic acid dihalide with an aromatic diamine and/or an aromatic aminocarboxylic acid halide. The aromatic polyamide fiber of the present invention may be an aromatic polyamide fiber made of a polyamide copolymer having a functional group having affinity with dyes in the polymer chain. In the present invention, when dyeing aromatic polyamide fibers, the dyes used are limited to cationic dyes (including basic dyes). The form of the dyed material may be cotton-like, thread-like, or knitted fabric-like, but is not limited thereto. The anionic surfactant used in the present invention is a surfactant having an active group that dissociates into an anion in a solution, such as carboxylate, sulfate, sulfonate, and phosphate. Acid ester salts are available, and sulfonate salts with good hydrothermal stability are particularly preferred. Some sulfonates include acylated alkyl sulfonates such as aliphatic ester sulfonates and aliphatic amide sulfonates, and alkylaryl sulfones such as sodium alkylbenzene sulfonate (ABS) and sodium alkylnaphthalene sulfonate. There are acid salts. The oxidizing agent used in the present invention is generally used as an oxidative bleaching agent, and includes, for example, sodium hypochlorite, potassium permanganate, sodium chlorite, peracetic acid, and hydrogen peroxide.
In particular, hydrogen peroxide, which has a low redox potential, is excellent because it causes less embrittlement of fibers. The dye is oxidized and decomposed by the oxygen generated from the oxidizing agent, but the conditions for activating the oxidizing agent are preferably alkaline with a pH of 8 or higher, and the activating agent is sodium silicate or phosphoric acid. Sodium is used. By using an oxidizing agent in combination with an anionic surfactant, the effect of improving color fastness is more remarkable than when using an anionic surfactant alone. As the hot water treatment conditions in the present invention, it is necessary to carry out the treatment at 60°C or higher. Below 60°C, the rate of decomposition of the dye by the oxidizing agent is slow and no effect on improving color fastness is observed. Preferably, it is effective to carry out the treatment near the boiling point of water. The dyed product obtained by the present invention has excellent color fastness and brightness, and can be widely used for general clothing interiors. The present invention will be explained below by giving examples. Example 1 A plain woven fabric (count 30/2, basis weight 200 g/m ² ) made of polymetaphenylene isophthalamide fibers was dyed in a dye bath with the following composition: Dye: CIBasic Blue 3 (cationic dye)
6% owf Salt: Sodium nitrate 25g/Swelling agent (carrier): Acetophenone
Staining was performed at 130°C for 90 minutes using an 80% owf bath ratio of 1:30. then 35% hydrogen peroxide, 0.5% alkylnaphthalene sulfonic acid anionic surfactant)
An aqueous solution (PH10.5) consisting of 2g/30% at 95°C.
After being treated with hot water for a minute, it was washed with water and dried. Various types of dyeing and fastness of the dyed fabrics were evaluated, and the results are shown in Table 1. Example 2 A fabric dyed as in Example 1 was dyed at 95% with an aqueous solution (PH10.5) consisting of 35% hydrogen peroxide and 0.5%.
Hydrothermally treated at ℃ for 30 minutes. Thereafter, the dyed cloth obtained by washing with water and drying was evaluated for various color fastnesses, and the results are shown in Table 1. Example 3 A fabric dyed as in Example 1 was treated with hot water at 95° C. for 30 minutes with an aqueous solution (PH 10.5) consisting of 2 g of alkylnaphthalene-sodium sulfonate. Thereafter, it was washed with water and dried, and various color fastnesses obtained were evaluated, and the results are shown in Table 1. Comparative Example 1 A fabric dyed as in Example 1 was treated with hot water at 95°C for 30 minutes with an aqueous solution containing 2 g of Score Roll #400 (manufactured by Kao Atlas Co., Ltd., an oleyl ether type nonionic surfactant). . Thereafter, the dyed fabric was washed with water and dried, and various color fastnesses of the obtained dyed fabric were evaluated, and the results are shown in Table 1. Comparative Example 2 A fabric dyed as in Example 1 was dyed at 95°C with an aqueous solution containing 2 g of hydrosulfite.
It was treated with hot water for 30 minutes. Thereafter, the dyed fabric was washed with water and dried, and various color fastnesses of the obtained dyed fabric were evaluated, and the results are shown in Table 1. Comparative Example 3 A fabric dyed as in Example 1 was treated with an aqueous solution (PH 10.5) consisting of 35% hydrogen peroxide 0.5% and 2 g/sodium alkylnaphthalene sulfonate.
Hydrothermal treatment was performed at 50°C for 30 minutes. Thereafter, the dyed cloth obtained by washing with water and drying was evaluated for various color fastnesses, and the results are shown in Table 1. Comparative Example 4 A fabric dyed as in Example 1 was treated with an aqueous solution (PH4) consisting of 35% hydrogen peroxide 0.5% and 2 g/sodium alkylnaphthalene sulfonate at 95%
Hydrothermally treated at ℃ for 30 minutes. Thereafter, the dyed cloth obtained by washing with water and drying was evaluated for various color fastnesses, and the results are shown in Table 1. 【table】

Claims (1)

[Claims] 1. An aromatic polyamide fiber dyed with a cationic dye, which is treated with hot water using a treatment liquid containing at least an anionic surfactant or an oxidizing agent during post-dyeing treatment of the aromatic polyamide fiber. staining method. 2. The method for dyeing aromatic polyamide fibers according to claim 1, characterized in that the pH of the treatment liquid is 8 or higher. 3. The method for dyeing aromatic polyamide fibers according to claim 1, wherein the hot water treatment temperature is 60°C or higher.