KR101233661B1 - A method of dyeing supermicrofibre nylon with acid and vat dyes - Google Patents

Abstract

The present invention is to provide a method for dyeing ultra-fine fibers that can increase the color tone concentration and the fastness to repeated washing after the dyeing of ultra-fine fibers to wash the fabric prepared in the present invention in order to achieve the object of the present invention. After the dyeing and drying the dried fabrics with acid dyes or bat dyes, a dyeing method of oxidizing and reducing the dyed fabrics after washing the dyeings after the full white coal is disclosed.

Description

A method of dyeing supermicrofibre nylon with acid and vat dyes}

The present invention relates to a method of dyeing fibers, and more particularly, to a method of dyeing ultrafine fibers using an acid dye or bat dye, and to dyeing an ultrafine fiber using an alkaline leuco form and an acidic leuco form of a bat dye. It is about a method.

Although polyamide fibers are mainly dyed with acid dyes, it is known that the wash fastness properties of the dyes on these fibers are insufficient. In general, 1: 2 pre-metallised acid dyes show a higher level of washing fastness compared to their nonmetallised counterparts, but are synthetic or natural softeners ( Post-treatment of dyed fibers with tanning is commonly used to achieve the highest level of wash fastness, especially in shades of medium to deep depth. Two-stage treatment of dyed nylon with tannic acid and potassium tartarate antimony constitutes a classic full backtan aftertreatment that is very effective in improving the wash fastness of acid dyes on nylon, but for many reasons the use of toxic antimony has recently It has been replaced by the use of protease enzymes and metal salts.

Polyamide microfibers typically have less than 1 dtex and are known to be used in a wide variety of apparel applications due to their soft hand, high luster and excellent drapeability. Since the polymers used in nylon microfibers are often the same as those used in conventional dtex fibers, the microfibers can be dyed in a manner similar to their conventional counterparts, and the microfibers are conventional per unit mass of the substrate. With a larger surface area than the phosphorus decitex fibers, the light reflection from the microfine fiber surface is greater, and therefore the amount of dye required to achieve the same visual density to that on conventional decitex fibers. For example, a 2.65% omf dye is required to produce a 0.5dtex microfiber at the same concentration as obtained using 1% omf dye on a 3.5dtex conventional fiber. Coupled with the inherently low or medium wash fastness properties of acid dyes on polyamide microfibers, this requirement for using higher amounts of dyes on polyamide microfibers is lower than that on conventional decitex nylon fibers. Equally dark dyeings are shown on polyamide microfibers showing fastness. In addition, larger surface areas of microfibers have been known to reduce wash fastness levels, resulting in greater speed and degree of dye desorption during washing, and this particular case was introduced about 40 years ago and was ˜1.1 × 10 ⁻⁴ to 0.33 dtex. It is exacerbated in the case of polyamide artificial suedes, which include "supermicrofibres" and are believed to be the origin of the fabric microfibers. Using the above example of 1% omf concentration hue on a 3.5dtex fiber, application of 38.7% omf dye is necessary to achieve the same concentration of hue on 0.05 microfiber suede.

Although bat dyes, which exhibit good light and wet fastness properties, are widely used on cellulose fibers, this class of dyes are generally pale tones resulting from their limited diffusion in the substrate and their low substantivity. Are not commonly used on polyamide fibers (except for their use in small amounts on nylon / cotton blends).

The dye contains at least two conjugated carbonyl groups which are converted to the corresponding water soluble "alkali leuco" form under alkaline conditions and applied to the substrate during application to their cellulose fibers. After completion of dyeing, the alkaline leuco form is oxidized to regenerate the insoluble parent bat dye directly in the fiber (Table 1).

However, the alkaline leuco form is easily converted to a sparingly water-soluble "acid leuco" variant (Table 1) that has been used to dye nylon fibers. In short, the acid leuco variant is similar to disperse dyes in terms of its adsorptive properties and is converted directly into an insoluble parent bat dye in the nylon substrate when oxidized after the end of dyeing.

* Reduction / oxidation of bat dye

(Table 1 shows insoluble parent vat dye: insoluble parent bat dye; reduction: reduction; oxidation: oxidation; soluble alkali leuco: sparingly soluble acid leuco: sparingly soluble acid leuco:

The present invention is to provide a dyeing method of ultra-fine fibers that can increase the color tone and color fastness to repeated washing after dyeing, modified full backtan after dyeing the ultra-fine fibers with acid dye or bat dye (modified full backtan) The purpose is achieved by processing.

In order to accomplish the object of the present invention as described above,

Washing and drying the prepared fabric (S1);

Dyeing the dried fabric with an acid dye or bat dye (S2);

Oxidizing and reducing washing the dyed fabric (S3); And

After the step (S3) comprises a step of post-treatment of the dye-full charcoal (S4),

It provides a method of dyeing ultra-fine fibers using an acid or bat dye.

The washing and drying in step (S1) is preferably performed at 50 to 70 ° C. for 20 to 35 minutes, and in this case, is preferably performed in an aqueous solution containing NaCO ₃ and a nonionic surfactant.

The drying temperature and time is a prediction range in which an optimal result can be obtained.

Temperature conditions and time in the present invention are conditions for the optimum results as described above.

In addition, the dyeing in the step (S2) is a dye of 3-5% omf while maintaining the temperature of the dye pot at 40 ~ 60 ℃ using a liquid ratio of 20: 1;

It is preferable to add at least one of a reducing agent, sodium hydroxide, and a dispersing agent, and then hold the fabric for about 15 to 25 minutes, and then insert the fabric to maintain the temperature at 95 to 100 ° C. at 1 to 2 ° C. per minute and then to maintain 50 to 70 minutes.

The omf in the above means the amount of dye used per fiber weight commonly used, and each additive in the present invention is to maintain the stability and conditions of the dye state for microfiber optimal dyeing.

In addition, the dyeing in the step (S2) may maintain the acidity at pH 5-7 when the fabric is introduced, and after the addition of the dye and the fabric and pH 5-7 buffer when the temperature in the dye pot is 40 ~ 50 ℃ 8 It may be maintained for 15 minutes and then heated to 95 to 100 ° C. at 1 to 2 ° C. per minute and then maintained for 50 to 70 minutes.

In addition, the oxidation in the step (S3) rinsed the dyed fabric for about 5 to 15 minutes, and then added hydrogen peroxide and acetic acid at a temperature of about 35 ~ 45 ℃ using a liquid ratio of 20: 1 and heated to about 65 ~ 75 ℃ After about 15 to 30 minutes can be maintained, the reduction washing in the step is added to sodium hyposulfite, sodium carbonate, surfactant at a temperature of about 35 ~ 45 ℃ using a liquid ratio of 20: 1 oxidized dyeing After heating up to about 55-65 degreeC, it can hold | maintain for about 15 to 30 minutes.

In addition, the full white coal post-treatment in the step (S4) after rinsing the dyeing for about 5 to 15 minutes and then maintained at 65 ~ 75 ℃ dyeing and tannic acid, pH 3 ~ 5 after adding acetic acid of about 10 to 20 minutes After holding, it can be performed by adding a fixing agent of 1 to 3omf and holding for about 10 to 20 minutes.

Artificial nylon suede presents problems in terms of washing fastness of acid dyes due to the very large surface area of the ultrafine fiber component. Due to the large fiber surface area, coupled with the inherent tendency of the dye to desorb from the dyeing suede, the need to apply a larger amount of dye to achieve the desired shade of color in the ultrafine fiber material is a characteristic poor wash of acid dyes in the artificial suede material. Results in fastness. The fastness of nylon suede dyed with three types of 1: 2 metal complex salts of 5% omf was markedly improved by post-treatment with full white coal. However, although full white coal treated dyes showed reduced dye loss during the wash at 60 ° C., a significant amount of dye loss still occurred during the wash test, which may be due to the large surface area of the substrate. In addition, despite the fact that the degree of contamination of adjacent multifiber strips was reduced by post-treatment with full white coal, the levels of contamination were still insufficient.

For bat staining, the color intensity of the 4% omf acid leuco dye was higher than that of the 4% alkali leuco dye, with the higher color intensity of the acid leuco dye remaining over the repeated wash. Although both types of bat dyes had significantly greater color intensity than their acid dye dyes, alkaline leuco dyes and acid leuco dyes showed significantly lower color loss compared to those obtained for acid dyes. .

In addition, alkali leuco dyes caused no contamination of adjacent nylon and wool materials and acid leuco dyes caused little contamination of adjacent nylon components during washing. Compared with the degree of contamination achieved for acid stained suede, both alkaline leuco dyes and acid leuco dyes exhibited significantly lower contamination of adjacent multifiber strips. The friction fastness of the bat dye was higher than that of the acid dye, but the level of friction fastness was only moderate, especially in the wet state.

These results indicate that dark dyeings with high fastness to repeat laundering at 60 ° C. and good dry friction fastness and moderate wet friction fastness can be obtained on artificial nylon suede. However, a number of bat dyes are being used to further characterize the colorimetric and color fastness (eg light fastness, sweat fastness, etc.) of acid leuco dyes on various dtex nylon fibers. Further development continues to identify the reason for the observed difference between the acidic leuco form of the bat dye and the dyeing of polyamide fibers using the alkaline leuco form.

1 is a treatment condition of the alkaline leuco bat dyeing method.
2 is a treatment condition of acid leuco bat dyeing method.
Figure 3 is a treatment condition for the application dyeing method of acid dyes.
4 shows processing conditions relating to an oxidation method.
5 is a processing condition of the reduction washing method.
Fig. 6 is a processing condition relating to full charcoal post-treatment.
7 is a graph of color intensity of acid and bat dye before and after repeated ISOCO6 / C2 wash tests.
FIG. 8 is a graph of color loss achieved in the case of acid and bat dye before and after repeated ISOCO6 / C2 wash tests.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.

[Example]

[Selection of materials]

[textile]

The artificial nylon suede (0.06 dtex) used was Daewoo Co. Ltd. From Seoul, South Korea. The fabric was washed for 30 minutes at 60 ° C. in an aqueous solution containing ₂ g dm ⁻³ Na ₂ CO ₃ and 5 g dm ⁻³ nonionic surfactant Lanapex R (ICI Surfactants). The washed suede was thoroughly rinsed in tap water and dried outdoors.

[dyes]

Acid dyes used in the present invention were purchased from Crompton & Knowles, and bat dyes used in this study were purchased from Town End Chemicals and Ciba-Geigy. These fibers are shown in Table 1 below. Each of these dyes was chosen as a representative of each dye class.

* Used 1: 2 type metal complex salt acid dyes and bat dyes

In Table 2, commercial name: commercial name; C.I. generic name: C.I. Common name

[Chemicals and supplements]

Rongalit C , a commercial reducing agent, was purchased from BASF, Sandozin NIE , a nonionic surfactant, was purchased from Clariant, and Matexil DA-N , a dispersant, was purchased from Uniqema. Samples of Floc-tan 1 , a tannic acid, and Gallofix , a binder derived from tin sulfate, were purchased from Omnichem-Ajinmoto. All other reagents applied were standard laboratory grades.

[dyeing]

Samples of nylon suede were stained using a liquid ratio of 20: 1 in a 300 cm ³ closed stainless steel dyepot placed in a Zeltex Polycolor PC 1000 laboratory scale dyeing machine. Dyeing methods used to apply bat dyes and acid dyes are shown in FIGS.

[Oxidation of Bat Dye]

After completion of staining, the same sample was rinsed in tap water for 10 minutes and then oxidized using a liquid ratio of 20: 1. (FIG. 4) The oxidized sample was rinsed in running water for 10 minutes.

[Reduction washing of bat dyes]

The rinsed and oxidized dyes were reduced washed using a 20: 1 liquid ratio (FIG. 5), and then the samples were rinsed in tap water and dried outdoors.

[Modified full backtan of 1: 2 type metal complex dyes]

After completion of the dyeing, the sample was rinsed in tap water for 10 minutes and then worked up using a one-bath two step process shown in FIG. The backtanned sample was rinsed in tap water and dried outdoors.

[Laundry fastness]

The dyed suede samples were subjected to five consecutive ISOCO6 / C2 wash tests.

After the end of each wash test, the samples were rinsed thoroughly in tap water. A new sample of SDC microfiber styrip was used to assess the degree of staining for each of the five wash tests. The degree of contamination of adjacent microfiber strips was expressed using a staining gray scale.

The extent to which the repeated washing test reduced the tint concentration of the dyeing was determined using the following equation (1).

Color loss (%) = (fk ₁ -fk ₂ / fk ₁ ) × 100

In the above formula, subscript 1 represents the color strength of the dye before washing, and subscript 2 represents the color strength of the laundry after each of the five washes.

[Frictional fastness]

Stained suede was tested according to the ISO X12 test method.

[Color measurement]

All measurements were made using a D ₆₅ light source and a 10 ° standard observer, using an X-rite Match-Rite spectrophotometer connected to a PC, excluding the specular component and including the UV component. The average of four recorded values was taken for each sample. Corresponding CIE colorimetric data and fk values were calculated from the reflectance data.

[Analysis and result]

[Acid dyes]

Table 3 below shows the colorimetric data obtained for polyamide suede stained with 5% omf of 1: 2 type metal complex salt acid dye, respectively, and also shows the results of washing tests of the dyeing 5 times repeatedly. In addition to the results for dyes not subjected to full white coal post-treatment in Table 3, the results for the dyes treated in the two-step post-treatment process shown in FIG. 6 are also included.

Colorimetric and wash fastness data for 5% omf acid dyes

In Table 3, dye: dye; After treatment: No. of washes: number of washes; staining of adjacent: contamination of adjacent fibers; acetate: acetate; cotton: cotton, nylon: nylon; acrylic: acrylic; wool: Wool; nil: none; full backtan: full whitetan)

[Untreated dyeings]

For dyes not post-treated with full white charcoal, repeated washing for each of the three dyes used reduced the depth of shade, as evidenced by an increase in brightness (L * value), but the color of the dye. It can be seen that (ho and saturation (C *)) were hardly affected. As shown in FIG. 7, the color intensity (fk) of the dye was decreased as the number of washings increased due to dye desorption generated for each of the five washing tests. The corresponding color loss (%) values obtained for untreated post-treatment before and after repeated washings are shown in FIG. 8. It can be seen from FIG. 8 that the degree of color loss achieved in the first two washes was greater than that obtained in the subsequent wash test. This result is explained by the corresponding decrease in the fk value shown in FIG. 7 and may be due to the remaining dye not removed from the dye after the end of the dye. The result that the percentage of color loss obtained for dyeings decreased with the increase in the number of washing tests may be due to the first two washes with the remaining dye removed. It can be seen from FIG. 8 that the three types of dyes changed in terms of the rate of color loss occurring over five washes, but the final degree of color loss was about 80%, showing little difference. Surprisingly, the floating dye removed from the dye during the wash was deposited on several adjacent fiber strip materials (Table 3).

In each case of the three dyes used, it is clear that the dyeings exhibited poor fastness for five successive wash fastness tests at 60 ° C., as confirmed by the contamination values achieved. Low contamination levels achieved in the case of adjacent acrylic, polyester, 2 ° acetate and cotton components were expected in view of the inherent low substantivity of the 1: 2 type metal complex salt acid dyes for this type of fiber. In addition, in view of the directness of the two types of dyes used, a very high degree of contamination was expected for the adjacent nylons 6, 6 and wool in which this type of dye was used. It is evident that the fastnesses of the dyeings achieved in the first two washing tests were markedly poor compared to those obtained in the subsequent washing (Table 3).

This may be due to the first two washes with the remaining dye removed as already discussed for the color loss value (%) shown in FIG. 8.

Post-treated dyeings

Table 3 shows the colorimetric data obtained for 5% omf dyes post-treated with full charcoal using the methods shown in FIGS. 6 and 7, and shows the corresponding fk values recorded for the dyes before and after repeated washing tests. Shows. Comparing these data with data for untreated dyes prior to the laundry test, it can be seen that for each of the three dyes, the post-treatment produced little change in both color and color intensity of the dye. This result is surprising given the discoloration that may occur with this particular post treatment, and may be due to the medium shades and relatively hazy shades used in the present invention. In the two-stage post-treatment used in the present invention, gallotannin was first applied to dyed nylon, and then the tannin treated fabric was treated with metal salts from a fresh salt bath. In the case of polyamide fibers, galotannin behaves as a high M _r acid which binds to protonated amino end groups in the substrate, and subsequent treatment with tin salts is placed on the surface of the dyed substrate and stained during washing. It is believed to result in the formation of large molecular size low water soluble complexes that provide a physical barrier to the diffusion of dye from the fabric. Comparing the laundry fastness data obtained for the post-treated dyes with those of the untreated post-treatment (Table 3), it is evident that full white coal improved the fastness to repeated washing at 60 ° C. The beneficial effect of the post treatment on the degree of color loss that occurred during washing is clearly seen in the data shown in FIG. 8. However, it is clear that full white charcoal was less effective in improving the wash fastness of CI Acid Blue 193 than improving the wash fastness of CI Acid Violet 90 or CI Acid Yellow 220 (FIG. 8).

Since post-treatment reduced the color loss (%) for each of the five washes performed (see FIG. 8), the corresponding color intensity of the post-treated dyeing was higher than the non-post-treated control (see FIG. 7).

The observed improvement in the wash fastness of each of the three acid dyes, provided by full white coal, limits the diffusion of dye out of the dyed artificial suede material during washing as suggested for acid dyes on polyamide fibres. This may be due to the surface "skin" of one large M _r of low water-soluble galotannin / tin composite. However, for such conventional nylon fibers, full charcoal aftertreatment provides a significant improvement in both color loss and degree of contamination of adjacent fibers during repeated washing. FIG. 8 shows that the dyed and post-treated polyamide suede suffered significant color loss as a result of repeated washing, while Table 3 shows that, after post-treatment, noticeable contamination of adjacent nylon and wool material occurred even after five washes. It is shown. The relatively large percentage of color loss and high levels of contamination observed in the post-treated dyeings are due to the inherent low or medium color fastness of the acid dyes on the nylon fibers. This may be due to the very large surface area considered.

Table 4 shows the rubbing fastness of the nylon suede dyed with three acid dyes. It is clear from Table 4 that the friction fastnesses were very poor, but the aftertreatment improved the fastnesses to a small extent.

* Friction fastness of 5% omf acid dyeing

(Table 4, Dye: Dye, After treatment; Dry: Dry; Wet: Wet; none: None; full backtan: Full white coal)

[Bat Dye]

As already mentioned, bat dyes are widely used for dyeing cellulose fibers, but many dyes exhibit low directivity to nylon fibers, and generally a tint arises due to the limited diffusion of these dyes in the substrate. However, the acid leuco form of some bat dyes has been found to give polyamide fibers dark shades of high overall fastness. In this study, both alkaline and acid leuco forms of bat dyes were used.

The application method used for the alkali leuco (FIG. 1) and acid leuco (FIG. 2) forms of the dye was devised as a result of previous studies conducted in our laboratory, which is described in nylon suede and the experimental paragraph above. One type of bat dye was included with one device.

Table 5 shows the colorimetric data, Figure 7 shows the corresponding color intensity values obtained for the 4% omf dyes of the three types of bat dyes before and after repeated washing, and the alkali and acid leuco dyeing methods used (Figures 1 and The results for 2) are shown. The color intensity of the acid leuco dye was higher than that of the alkali leuco dye, and the fk value gradually decreased with increasing washing frequency, but the higher color intensity of this acid leuco form persisted over five repeated washes. For CI Vat Violet 1 and CI Vat Blue 18, the color of the acid leuco dye before and after the washing test was different from that of the alkaline leuco dye, and a much smaller color difference between the acid leuco dye and the alkali leuco dye of CI Vat Green 3 Was obtained. The reason for the difference in color and color intensity observed for the acidic leuco and alkaline leuco dyes of the three types of bat dyes is not yet known, but a relatively large number of bat dyes and a wide range of batting, dyeing and washing Results obtained using clearing conditions suggest that dye aggregation is a major but not decisive factor in terms of color, and the higher color intensities typically achieved in the case of leuco acid dyeing are the of -O ^- as compared to the form it suggests that be due to a lower solubility and higher substantivity (substantivity) of the -OH derivative. Subsequent papers addressing this issue will be published.

Colorimetric and wash fastness data for 4% omf of bat dye

(Table 5, Dye: Dye, After treatment: No of washes: Number of washes, Staining of adjacent: Contamination of adjacent fibers; Acetate: Acetate, Cotton: Cotton, Nylon: Nylon, PET: PET, Acrylic: Acrylic , Wool: wool, alkali leuco: alkali leuco, acid leuco: acid leuco)

It is clear that both the alkaline leuco dye and the acid leuco dye received only a small percentage of color loss during the repeated washing (FIG. 8) and the degree of color loss seen between the acid leuco dye and the alkaline leuco dye was relatively small. . The weekly small color loss values obtained (%) are reflected in the corresponding wash fastness results (Table 5), suggesting that both acid leuco dyes and alkali leuco dyes showed very good wash fastnesses during repeated washings. Contamination of adjacent nylon components was observed for each of the three dyes, but slight contamination of adjacent diacetate fibers was observed in C.I. Obtained only for Vat Green 3.

[Comparison of Acid Dye and Bat Dye]

From the fastness results shown in Tables 3 and 5, although the bat dye has a much higher color intensity (FIG. 7), the bat dye (both acid and alkali leuco forms) is more than both untreated and post-treated acid dyes. It was clearly seen that the fastnesses were high and the bat dyes exhibited a significantly lower percentage of color loss during the repeated wash test (FIG. 8). Since the same scale was used for the y-axis of Figures 7 and 8, it can be clearly seen that the higher hue concentration and lower dye loss obtained for the bat dye.

Table 6 shows that the dry rub fastness of the bat dye is naturally acceptable, while the wet rubbing fastness is less than three. Nevertheless, the friction fastness ratings obtained for the bat dyes were much higher than the acid dyes, despite the significantly greater color intensity of the bat dyes (Table 4).

* Rubbing fastness of 4% omf bat dye

(Table 6, Dye: dye, Application method: application method, alkali leuko: alkali leuco, acid leuko: acid leuco, dry: dry, wet: wet)

The reasons for the observed very high color intensity of the bat dyes and their higher levels of wash and friction fastness still need to be explained. This may be because the degree of dye exhaustion is greater in the case of bat dyes or the dye content of the bat dye samples is greater than the dye content of the acid dye samples used. These and other explanations require investigation.

Claims (8)

Washing and drying the prepared fabric (S1);
Dyeing the dried fabric with an acid dye or bat dye (S2);
Oxidizing and reducing washing the dyed fabric (S3); And
After the step (S3) comprises a step of post-treatment of the dye-full charcoal (S4),
Method for dyeing ultra-fine fibers, characterized in that the use of acid or bat dye. The method of claim 1, wherein the washing drying step (S1) is a method for dyeing ultra-fine fibers, characterized in that performed for 20 to 35 minutes at 50 ~ 70 ℃. The method of claim 1, wherein the dyeing in step (S2) is carried out using a liquid ratio of 20: 1 with a dye of 3-5% omf while maintaining the temperature of the dye pot at 40 ~ 60 ℃;
Adding at least one of reducing agent, sodium hydroxide and dispersing agent, and maintaining the fabric for 15 to 25 minutes, and then putting the fabric, and dyeing the ultra-fine fibers, characterized in that the temperature is maintained at 1 to 2 ℃ per minute to 95 to 100 ℃ and maintained for 50 to 70 minutes Way. The method of claim 1, wherein the dyeing in step (S2) is a method of dyeing ultra-fine fibers, characterized in that the acidity is maintained at pH 5-7 when the fabric is introduced. The dyeing process of claim 1, wherein the dyeing step (S2) is carried out for 8 to 15 minutes after the addition of the dye and the fabric and the pH 5-7 buffer when the temperature in the dye pot is 40 ~ 50 ℃ 1 ~ 2 per minute Method for dyeing ultra-fine fibers characterized in that the temperature is maintained at 95 ~ 100 ℃ ℃ and maintained for 50 to 70 minutes. The oxidation in the step (S3) is rinsed the dyed fabric for 5 to 15 minutes and then added hydrogen peroxide and acetic acid at a temperature of 35 ~ 45 ℃ using a liquid ratio of 20: 1 and the temperature is raised to 65 ~ 75 ℃ Method for dyeing ultra-fine fibers, characterized in that it is carried out by maintaining for 15 to 30 minutes. According to claim 1, wherein the reduced washing in step (S3) is added to the sodium sulphite, sodium carbonate, surfactant at a temperature of 35 ~ 45 ℃ using a liquid ratio of 20: 1 liquid ratio to 55 ~ 65 ℃ The method of dyeing ultra-fine fibers characterized in that the temperature is maintained for 15 to 30 minutes after heating. The method of claim 1, wherein the full white coal post-treatment in step S4 is performed after rinsing the dyeing for 5 to 15 minutes and then adding the dyeing and tannic acid, and acetic acid having a pH of 3 to 5 while maintaining the temperature at 65 to 75 ° C. Method for dyeing ultra-fine fibers, characterized in that the addition of 1 to 3omf fixing agent for 20 minutes, and maintained for 10 to 20 minutes.

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