JPH0615749B2 - Aromatic aramid fiber dyeing method - Google Patents

Description

The present invention relates to a method for dyeing aromatic aramid fibers.

[Conventional technology]

Aromatic aramid fibers are synthetic fibers with excellent mechanical strength, and are used in general industrial materials (ropes, cables, cords, braids, woven belts, canvas, filters, etc.) and fishing nets (trawl nets, stationary nets, gill nets, Net cage, purse net, etc., rubber reinforcements (tires, belts, hoses, etc.), protective clothing (bulletproof clothing,
It is being used for cutting resistant clothing, etc.) and asbestos substitute materials (friction materials, gaskets, packing, etc.).

By the way, it is generally said that synthetic fibers are difficult to dye, and in particular, the above-mentioned aromatic aramid fibers have been hardly dyed so far.

That is, the aromatic aramid fiber is a long chain of chain molecules, and it has regular and densely arranged crystalline regions (the part that is the source of strength) and irregularly arranged amorphous regions (dyed). It is composed of easy parts), but the molecules are pulled by friction by being strongly stretched during the spinning process, and the molecules on the outer side are more regularly arranged, as if a film had been formed. This is the reason why it is difficult to dye the aromatic aramid fiber, and since the special oil is applied to reduce friction at the spinning stage, the dyeing is made more difficult.

[Problems to be Solved by the Invention]

However, in consideration of various uses of the aromatic aramid fiber, the inability to be dyed is a great drawback, and the commercial value thereof may be significantly lowered.

Then, this invention is proposed in view of the said conventional condition, and an object of this invention is to provide the dyeing method which enables dyeing of the aromatic aramid fiber which dyeing is very difficult.

[Means for Solving the Problems] The present inventor, in order to achieve the above-mentioned object, as a result of intensive studies, as a result of the use of a certain dye under a specific reduced pressure, the aromatic aramid fiber It has been found that dyeing is possible.

That is, in the present invention, the aromatic aramid fiber is immersed in a dyeing solution containing any one of brilliant green, eosin yellow, Nile blue, neutral red, congo red, and malachite green, and 160 to 210
It is characterized in that it is dyed under vacuum reduced pressure of mmHg.

In the present invention, the aromatic aramid fiber to be dyed is, for example, It has the following characteristics.

Specific gravity: 1.39 g / cm ³ Pyrolysis temperature: Approx. 500 ° C. Equilibrium moisture content: 3% Limiting oxygen index: 25% When dyeing this aromatic aramid fiber, the dyeability, affinity, levelness of the dye, It is necessary that various factors such as dyeing speed and dyeing mechanism work optimally, and in addition, the most effective method for swelling the chain molecules of the fiber is required.

From this point of view, the selection of the dye becomes an important requirement,
In the present invention, a special dye used in so-called biological dyeing (living dyeing, bacterial dyeing, etc.) in the field of medicine and the like is used. Specifically, they are Brilliant Green, Eosin Yellow, Nile Blue, Neutral Red, Congo Red, and Malachite Green. One or two of these can be selected depending on the desired color tone.
You can choose more than one species.

On the other hand, when dyeing, it is necessary to reduce the pressure in vacuum.
In this case, if the pressure is reduced too much, the special dye may be decomposed, and conversely, if the degree of vacuum is insufficient, the swelling of the fiber becomes insufficient, and good dyeing is difficult in any case. According to experiments by the present inventors, 550 to 600 mmHg
When decompressed (ie 160-210mm in absolute pressure)
It has been found that good dyeing conditions are obtained (at Hg).

The dyeing solution may be kept at room temperature for dyeing and can be sufficiently dyed without heating, but it is of course also possible to heat it if necessary.

[Action] Special dyes represented by Brilliant Green, Eosin Yellow, Nile Blue, Neutral Red, Condo Red, and Malachite Green exhibit excellent dyeability on aromatic aramid fibers.

However, it is necessary to reduce the pressure in vacuum during dyeing. That is, the chain molecules of the aromatic aramid fiber as the material to be dyed are swelled to the maximum by vacuum decompression, and at the same time, the dye is uniformly dissolved in the solution (pure water). This enhances the levelness of the dye, enhances the dye affinity (the power of the dye from the solution phase-dye bath to the polymer phase-fiber), increases the dyeing speed, and facilitates the dye to be adsorbed on the fiber. In addition, the amorphous region (portion arranged irregularly) diffuses and the dyeing property increases until reaching the dyeing equilibrium, and the dyeing is performed evenly.

In the present invention, vacuum decompression is selected in the optimum range, so that the dye does not decompose during dyeing.

〔Example〕

 Hereinafter, the present invention will be described based on specific experimental results.

Structure of Vacuum Device First, the structure of the vacuum device used for dyeing in this experiment is shown in FIGS. 1 and 2.

This vacuum device includes a vacuum tank body (1), an air compressor (2), an auxiliary oil rotary pump (3), a main oil rotary pump (4),
The collective operation panel (5) is the main component.

The vacuum tank body (1) is provided with an opening / closing hatch (6), and by opening the opening / closing hatch (6), the aromatic aramid fiber is loaded or unloaded. Further, at the top of the vacuum tank body (1), a rod for dipping and lifting the aromatic aramid fiber in the dyeing solution.
(7) is provided. Further, on the peripheral wall of the vacuum pump body (1), a pressure gauge (8) for checking the depressurized state of the vacuum tank body (1) and a plurality of visual indicators for visually observing the inside of the vacuum pump body (1) are provided. A window (9) and an atmosphere introduction valve (10) for releasing the reduced pressure are provided.

On the other hand, the exhaust system is composed of an air compressor (2), an auxiliary oil rotary pump (3) and a main oil rotary pump (4), but a plurality of exhaust valves (11) are provided in the middle of the system. There is also a pressure gauge (12) on the air compressor (2),
The main oil rotary pump (4) is provided with an exhaust outlet (13).

Operation procedure of vacuum device To operate the vacuum device, AC power supply 200V / 3 phase /
30 kW is supplied to the collective operation panel (5) of the vacuum device. Then, the ac power source 200V is applied to the collective operation panel (5) of the vacuum device.
After confirming that / 3 phase / 30 kW is supplied, the procedure of the following operation is performed.

First, the air compressor (2) [0.5 kW,
Rotation speed 1420 / rpm, pressure 1-10 kg] is started.
The exhaust valve of the vacuum device is automatically opened and closed by the pressure of 5 kg.
Run for about 5 minutes until the pressure is reached.

After confirming that the air compressor (2) is automatically stopped, the auxiliary oil rotary pump (3) [200V / 3
Phase / 0.4 kW, rotation speed 530 rpm] is started (turned on). After about 5 minutes, the main oil rotary pump (4) [200V / 3 phase /
2.2 kW, rotation speed 410 rpm] is started (turned on) and exhausted. When the pressure gauge (8) has reached the required reduced pressure, the auxiliary oil rotary pump (3) and the main oil rotary pump (4) are each stopped (off).

Dyeing process While inspecting the inside of the vacuum tank body (1) illuminated from the viewing window (9), first put the dye and pure water into the manual bucket inside the vacuum tank body (1) and make sure that they are uniformly dissolved. After checking, the raw yarn and the twisted yarn attached to the tip of the protruding rod (7) are immersed in the solution. As the raw yarn and the twisted yarn, Technora (registered trademark, manufactured by Teijin Limited) raw yarn and twisted yarn made of aromatic aramid fiber were used. Maximum exhaust pressure reduction (750 mmH
As a result of lowering the temperature to g) and conducting an experiment, the solution (staining solution) came out of the hot water, making dyeing impossible. Therefore, the atmosphere was introduced and the reduced pressure was not adjusted stepwise, and dyeing was performed. Decompression is 200 mmHg-7
There are 11 steps between 00 mmHg (60 mmHg to 560 mmHg in absolute pressure) (slide 50 mmHg each).
Staining at each stage was performed in the same manner.

The material to be dyed is pulled up from the solution by the stick (7) and dried under reduced pressure for about 5 minutes, and then the atmosphere of the vacuum tank body (1) is introduced. After confirming that the inside of the vacuum tank body (1) has returned to atmospheric pressure, the opening / closing hatch (6) is opened to take out the material to be dyed, and further dried in the atmosphere for about 5 minutes. Then boil for 5 minutes. It is dried again in the air, and all the above steps are repeated to dye twice. Although it is a finishing step with the second boiling, the final step is washing with water, and the whole dyeing process is completed.

Results of dyeing experiment The following six dyes were used in the experiment.

A: Brilliant green (for bacterial staining. Soluble in water and alcohol. Gold-shining powder.) B: Eosin yellow (for cytoplasmic staining. Easily soluble in water, sparingly soluble in alcohol. Reddish brown powder.) C: Nile blue. (For fat and Heinz body staining. Alcohol, soluble in hot water. Dark green powder.) D: Neutral red (For bacterial staining. Soluble in water, alcohol. Dark green powder.) E: Congo red ( For amyloid staining. Soluble in water, sparingly soluble in alcohol. F: Malachite green (For spore staining. Soluble in alcohol, soluble in water.) In any case, under reduced pressure of 550 to 600 mmHg (that is, absolute The most effective dyeing condition was obtained at a pressure of 160-210 mmHg).

Also, when the dyeing fastness at this time was examined, it showed good dyeing fastness to washing with water and chlorine bleaching, and the heat resistance was 90% of that of the aromatic aramid fiber.
I was holding.

〔The invention's effect〕

As is clear from the above description, in the present invention,
Since dyeing is performed under a specific vacuum and reduced pressure using a specific dye, it is possible to obtain a good dyeing state for aromatic aramid fibers, which have been almost impossible to dye until now.

[Brief description of drawings]

FIG. 1 is a side view showing a schematic configuration of a vacuum device used for dyeing, and FIG. 2 is a front view.

Claims (1)

[Claims] 1. An aromatic aramid fiber is immersed in a dyeing solution containing any one of brilliant green, eosin yellow, nile blue, neutral red, congo red, and malachite green, and dyed under a vacuum reduced pressure of 160 to 210 mmHg. A method for dyeing an aromatic aramid fiber, which comprises: