JPH0376880A - Method for dyeing aromatic polyamide fiber - Google Patents

Abstract

PURPOSE:To readily obtain a dyed product excellent in color fastness to light in a practical concentration by dyeing specific aromatic polyamide fiber having hydrophilic groups with a vat dye having high color fastness to light in the presence of a reducing agent and alkali solution. CONSTITUTION:Aromatic polyamide fiber [e.g. poly(m-phenylene isopthalamide)] produced from an aromatic polyfunctional carboxylic acid (e.g. isophthalic acid-5-sulfonate or trimellitate) containing sulfonate group expressed by the formula SO3M1 (M1 is alkali metal) or carboxylate group expressed by the formula COOM2 (M2 is alkali metal), etc., an aromatic polyfunctional carboxylic acid and an aromatic diisocyanate is dyed with a vat dye having class >=7 of color fastness to light in the presence of a reducing agent and an alkali solution to readily afford a dyed product excellent in color fastness to light in a practical high concentration.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is based on the method of manufacturing aromatic polyamide fibers containing hydrophilic groups in the presence of a reducing agent and an alkaline solution using a vat dye with a light fastness of class 7 or higher. Concerning how to dye.

[Prior Art] Aromatic polyamide fibers, such as poly(metaphenylene isophthalate), have excellent properties such as flame retardancy, heat resistance, and solvent resistance, and are used in a wide range of fields.

In particular, taking advantage of its flame retardant and heat resistant properties, its use in bedding, clothing, and indoor living is rapidly increasing.

However, because the polymer molecular chains are extremely rigid, it is difficult to dye them using normal methods, and dyeing with high light fastness is difficult.
It has been difficult to obtain a free combination of colors using a simple and economical method.

For this reason, various methods for improving dyeing properties have been proposed up to now. A method of incorporating an ammonium group in a polymer molecular chain or at the end of a polymer molecule,
There is a method using a highly polar carrier as shown in JP-A-58-87376, and a method of adding dimethyl sulfoxide as shown in JP-A-62-268877.

However, these dyeing methods use highly polar carriers that are problematic for the environment, solvents such as dimethyl sulfoxide, and the dyes used are cationic,
Because dispersion or acidic dyes are used, the dyeing properties are satisfactory to some extent, but the light resistance of the dyed products is extremely poor and cannot be put to practical use. Sulfone group-containing aromatic polyamides produced from sodium diacid chloride monosulfonates are practically difficult to use for heat-resistant applications because dyed products undergo significant discoloration due to heat.

On the other hand, the vat dye used in the original dyeing shown in Japanese Patent Publication No. 51-45688 has good light fastness, but because it is an original dye, piece dyeing is not possible and free color combinations and tone control are not possible. With no drawbacks.

(Problem to be Solved by the Invention) The problem of the present invention is to solve the problem of aromatic polyvalent polyhydric acid containing hydrophilic groups without using a highly polar carrier or a solvent such as dimethyl sulfoxide, which causes problems in the environment as described above. Aromatic polyhydric fibers produced from carboxylic acids, aromatic polycarboxylic acids, and aromatic diisocyanates are dyed to a practical density using a vat dye with good sunlight fastness in the coexistence of a reducing agent and an alkaline solution. The object of the present invention is to provide an aromatic boria fiber having good dyeing light resistance.

[Means to solve problems]

As a result of intensive studies to solve the above problem, the present inventors made aromatic aramid fibers containing hydrophilic groups coexisting with a reducing agent and an alkaline solution, and used a vat dye with a sunlight fastness level of 7 or higher. The present invention was completed based on the discovery that a practical dyed product with high density and good light resistance can be obtained by dyeing the dyed product.

That is, the present invention provides aromatic polyamide fibers produced from an aromatic polycarboxylic acid containing a hydrophilic group, an aromatic polycarboxylic acid, and an aromatic diisocyanate in the presence of a reducing agent and an alkali solution to improve light fastness. This is a method for dyeing aromatic polyamide fibers, which is characterized by dyeing using a vat dye of grade 7 or higher.

[Preferred embodiment for carrying out the invention] The hydrophilic group of the aromatic polycarboxylic acid containing a hydrophilic group used in the present invention is represented by -3O,M, (MI=alkali metal). Sulfonic acid group, COO? h (
Specific examples of aromatic polyhydric carboxylic acids containing -5OJ+ include sodium isophthalic acid-5-sulfonate, terephthalic acid-2-sulfonic acid, etc. sodium,
41゛-diphenyl ether-dicarboxylic acid-2,2'
-disodium sulfonate, 4.4'-diphenyl-
dicarboxylic acid-2,2'-disodium sulfonate,
4.4'-diphenylsulfide-dicarboxylic acid-2,
2゛-disodium sulfonate, etc., as well as sodium-2,4-sia[nobenzenesulfonate, 4,4°-
Examples include diaminodiphenylmethane-2,2'-di-sodium sulfonate, and potassium and lithium salts of the above compounds are also effective.

Specific examples of aromatic polycarboxylic acids containing -COOMt include monosodium trimellitate, disodium pyromellitate, disodium butanetetracarboxylate, and potassium and lithium salts of the above compounds. It is valid.

The method for incorporating these hydrophilic groups into aromatic polyamide fibers is not particularly limited, but for example, 1) Mixing an aromatic polycarboxylic acid and a polycarboxylic acid having a hydrophilic group, and polymerizing the mixture with an aromatic diisocyanate at high temperature. (2) Mixing and dissolving these copolymers in a polymer made from an aromatic polycarboxylic acid and an aromatic diisocyanate that do not have hydrophilic groups using a solvent. There is a method of containing it.

The effect of the hydrophilic groups is about 5 to 10% better than that of (2) containing hydrophilic groups as a copolymer by mixing and dissolving them. As a result of considering both the dyeing density and the practical strength of the fiber, the concentration of hydrophilic groups in the aromatic polyamide fiber is 0.5 mol% to 50 mol%, preferably 'l
The range of a+o1% to 30 mo1% is preferable.

The dye used in the method of the present invention is a bunt dye with good light fastness.

The composition of a dyeing bath for dyeing aromatic polyamide fibers containing hydrophilic groups with such dyes includes vat dyes, dyeing aids such as glucose, fructose, aldohexoses such as mannose, and maltose. , oligosaccharides such as sig sugar, and polysaccharides such as starch and cellulose. Although the effects of these dyeing aids are not well understood, they have the effect of preventing over-reduction of vat dyes during high-temperature dyeing (80'C or higher) and improving color tone.

To reduce the vat dye, hydrosulfide, a zinc salt of hydroxymethanesulfinic acid known under the trade name Dechlorin, or sodium hydroxymethanesulfinate known under the tradename Rongalit C, etc. are used.

As the alkaline liquid, sodium hydroxide, potassium hydroxide, water glass, potassium carbonate, or a mixture thereof is used.

The concentrations of these dyeing aids, reducing agents, and alkaline liquids are not particularly limited, and any concentration range frequently used in ordinary dyeing is sufficient. Generally, dyeing aid number is 1~20g/
The amount of L reducing agent used is 5 to 40 g/it, and the concentration of alkaline solution is about 0.1 to 5% by weight.

Addition of an electrolyte such as sodium chloride or sodium sulfate is also effective for improving dyeing properties.

The temperature during dyeing in the above bath composition is 60-15
0''C1 staining time is preferably 30 to 90 minutes.

The aromatic polyamide fiber containing hydrophilic groups after dyeing is
The vat dye is oxidized and soaped according to the usual post-treatment, and the temperature at this time is preferably 80°C or higher.

〔Example〕

The present invention will be explained below with reference to Examples. In the examples, parts indicate parts by weight.

Example 1 In a 51 separable flask equipped with a stirrer, a thermometer, a condenser, a dropping funnel, and a nitrogen inlet tube, 16.61 g (0.10 mol) of terephthalic acid and 28.9 g (0.10 mol) of isophthalic acid were added.
42 (1,70 mol), sodium isophthalate-5-sulfonate (hereinafter abbreviated as 5-IPA) 53.62
g (0.2 mol), potassium fluoride 0.58 g (
0°01 mol) and the solvent 1,3-dimethyl-2-ξdasiridinone (hereinafter abbreviated as old) were added, the mixture was heated to 200°C, and tolylene-2,6
- 350.1 g (2.01 mol) of diisocyanate was added dropwise over 2 hours, and the polymer gradually became viscous. After further stirring, the mixture was cooled to room temperature. This pale yellow viscous liquid was degassed under reduced pressure, filtered, heated to 100°C, and extruded into a heated air stream through a spinner with a 100-hole spinneret to dry-spun tow. DMI this tow
ts% and 30% calcium chloride in hot water at 80°C, and then DMI and calcium chloride were removed in the hot water. Further, heat setting was performed at 270''C for 5 minutes to obtain a filament of 10d/100fil.

This filament was wound around a 4cm x 5cm SUS wax, and placed in a dyeing bath with the following composition and heated at 130°C for 90 minutes.
The sample was treated for 0 minutes and then cooled to room temperature.

Mikethren RSN s/4 0.2 parts (manufactured by Mitsui Toatsu Dye Co., Ltd.) 308e' NaOH 3.2 parts Glucose 0.2 parts Rongalitto C1.2 parts Water 195 parts Next, add 1.2 parts of sodium perborate. , and oxidized at 90''C for 30 minutes.Subsequently, the sample was treated for one portion in a soapinda solution at 95°C containing 3% of Monogen Paste (anionic surfactant manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and then washed with water and dried.

The filaments were stained dark blue. The dyed filament was irradiated with an ultraviolet vAa graphite fade meter PAL5H (manufactured by Suga Test Instruments) (hereinafter abbreviated as FO) for 20 hours. The color fastness after irradiation was grade 4 on the blue scale.

Example 2 Polymerization and dyeing were carried out in the same manner as in Example 1, except that the proportion of sodium isophthalate-5-sulfonate was changed as shown in the table below, and the dyeability and color fastness were evaluated.

Table-1 Except for using In (vat dye manufactured by Mitsui Toatsu Dye Co., Ltd.),
Dyeing was carried out in the same manner as in Example 2, and the dyeability and color fastness were evaluated. The results are shown in Table-2.

Table 2 Comparative Example 1 The filaments with different 34PA contents produced in Example 1 and Example 2 were respectively treated with Mikethren R2Hs/
Mitsui Tsuya Indigo instead of f
2B Super Fa From this point on, indigo-based vat dyes are
It can be seen that the dyeability is good, but the color fastness is low. However, it can be seen that those containing 5-IPA have improved dyeability and color fastness compared to those without.

Example 3 The filaments with different 5-IP^ contents produced in Example 1 and Example 2 were treated with Mtkethren R2Hs, respectively.
Mike instead of /f (vat dye manufactured by Mitsui Toatsu Dye Co., Ltd.)
-thren Dark Blue BOA s/f
(Vat dye manufactured by Mitsui Toatsu Dye Co., Ltd.) was used for dyeing in the same manner as in Example 1, except that glucose was not used, and the dyeability and color fastness were evaluated. The results are shown in Table-3.

Table 3 Comparative Example 2 Dehydrated N,N"-dimethylacetamide (DMAC)
646.2 g of metaphenylenediamine distilled to 51% was melted and cooled to -15°C in a dry ice-methanol bath. 1215 g of isophthalofluoride was added dropwise to this while stirring while maintaining the temperature at 20''C.

After the dropwise addition was completed, the temperature was raised to 30°C over 30 minutes and kept at 30°C for 120 minutes.

After the reaction, add 450 g of anhydrous calcium hydroxide and add 10
The mixture was heated at 0°C for 90 minutes to neutralize the hydrogen chloride produced. This is referred to as polymerization solution (a).

Similarly, 316.3 g of sodium isophthaloyl chloride-4-sulfonate (abbreviated as 5-rpc)
, 210.6 g of isophthaloyl chloride and 226.4 g of metaphenylenediamine were polymerized in 3170 g of DMAC. 288 g of anhydrous calcium chloride was added to this to neutralize the generated hydrogen chloride. This polymerization solution is referred to as (b).

Polymerization solution (a) and polymerization 1(b) were mixed in the proportions shown below to form a uniform solution. (See Table 4) Table 4 Table 5 These solutions were subjected to spinning in the same manner as in Example 1 to obtain respective filaments. Each of these filaments was dyed in the same manner as in Example I, and the dyeability and color fastness were evaluated. The results are shown in Table-5.

In addition, the above filaments C-2-2 to G-2-4 were
When I put it in the oven at °C and left it for 10 minutes, all of them had a spicy taste.

〔effect〕

By applying the method of the present invention to aromatic polyamide fibers containing hydrophilic groups, they can be easily dyed with a wide range of vat dyes with good light fastness to practical concentrations, and the dyed products can be used for clothing, interior decoration, etc. Available.

Claims (1)

[Claims] 1. An aromatic polyamide fiber produced from an aromatic polycarboxylic acid containing a hydrophilic group, an aromatic polycarboxylic acid, and an aromatic diisocyanate in the presence of a reducing agent and an alkaline solution, A method for dyeing aromatic polyamide fibers, which comprises dyeing using a vat dye having a light fastness of grade 7 or higher. 2. The method according to claim 1, wherein the hydrophilic group is a sulfonic acid group represented by -SO_3M_1 (M_1 represents an alkali metal). 3. The method according to claim 1, wherein the hydrophilic group is a carboxylic acid group represented by -COOM_2 (M_2 represents an alkali metal).