JP2000328468A - Method for dyeing with vat dye - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dyeing method by which a fiber product such as a rayon product can be dyed with a vat dye in excellent reproduction, dyeing levelness and fastness. SOLUTION: This method for dyeing comprises dyeing a fiber product with a vat dye in the presence of an alkali agent and a reducing agent. Therein, >=30% of air in the gaseous phase portions of a dyeing machine is replaced with an inert gas. The method can be applied to the fiber product comprising rayon, cupra, polynosic fibers, tencel, lyocell, polyvinyl alcohol-based fibers or polyamide-based fibers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dyeing textile products with a vat dye.

[0002]

2. Description of the Related Art Vat dyes have long been known as dyes excellent in wet fastness, light fastness and chlorine fastness. On the other hand, build-up properties, reproducibility, and leveling properties are not sufficient, and they have been used by increasing the amount of leveling agent used and lengthening the dyeing time only in limited fields.

For this reason, rayon, cupra, polynosic fiber, tencel and lyocell often use linear dyes and reactive dyes, polyvinyl alcohol fibers use direct dyes, and polyamide fibers use acid dyes and alloy complex dyes. The dyeing method used is generally adopted.

[0004] However, in recent years, demands for dyeings having even better wet fastness, light fastness and chlorine fastness have increased due to the higher quality of products, the importance of hygiene, and the like. Review has become necessary.

[0005] In dyeing with a vat dye, the dye dispersed in the bath forms a leuco salt soluble in water in the presence of an alkali agent and a reducing agent, and is adsorbed to the fiber. However, in the case of vat dyes, the initial strike property is very large, and uniform adsorption of the dye is relatively difficult. Further, the inside of the dyeing machine is composed of a dyeing liquid part and a gaseous phase part, but the object to be dyed generally moves alternately between the dyeing liquid part and the gaseous part. In this case, the dye that has formed a leuco salt on the material to be dyed is partially oxidized and insolubilized by the air in the gaseous phase, resulting in uneven dyeing.

Furthermore, since the added reducing agent is oxidized by air in the gas phase, the absolute amount of the reducing agent required to convert the dye into a leuco salt is insufficient. Therefore, the reducing agent is added in excess in advance, but the mainly used hydrosulfite is poor in persistence.Addition of an excessive amount causes excessive reduction, insufficient dyeing, poor reproducibility. And many problems such as uneven dyeing occur.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for dyeing various kinds of textile products by using such a vat dye, which enables uniform dyeing with excellent build-up properties and reproducibility. I do.

[0008]

According to the present invention, rayon,
Cupra, polynosic, Tencel, lyocell, a fiber product selected from the group consisting of polyvinyl alcohol-based fiber and polyamide-based fiber, in the presence of an alkali agent and a reducing agent, when dyeing with a vat dye, an inert gas By replacing the air in the gas phase portion of the dyeing machine with an inert gas by using the above method, it was possible to uniformly dye these fiber products with various fastnesses.

That is, the present invention provides a dyeing method in which a vat dye is dyed on a material to be dyed in the form of a leuco salt in the presence of an alkali agent and a reducing agent. It is characterized by being replaced by 30% or more with an active gas.

[0010] In the closed type dyeing machine replaced with an inert gas, the added reducing agent is hardly consumed by air oxidation, and the vat dye also remains in the form of leuco salt from the initial stage of dyeing to the end of adsorption. The existing water-soluble vat dye in the form of leuco salt has a very large migration of the dye during the dyeing step, and uniform dyeing is easily obtained.

Vat dyes have particularly high strike properties in the early stage of dyeing and, due to the large initial adsorption amount of the dye, are liable to cause nonuniform adsorption to the dyeing object. However, if an inert gas is used to prevent disproportionate dyeing due to air oxidation, the dye transfer during the dyeing process becomes a dyeing method that makes it easy to obtain uniform dyeing using a water-soluble vat dye in the form of a leuco salt. It is.

In the method of the present invention, since there is little problem of uneven adsorption of the dye in the heating step, the heating rate can be increased, the dyeing time is shortened, and the dyeing process is the most recent. Important rationalization is possible.

The fiber product to be dyed by the method of the present invention may be a fiber product selected from the group consisting of rayon, cupra, polynosic fiber, tencel, lyocell, polyvinyl alcohol fiber and polyamide fiber.
A product formed of these fibers alone may be a composite product with other fibers.

As the inert gas, any of nitrogen gas, helium gas, neon gas, argon gas and the like can be used, but nitrogen gas is most preferable because it is easily available at low cost. Further, the replacement ratio by these inert gases is 70%.
%, Especially 85% or more.

As the alkali agent used for dyeing, any of those generally used in dyeing methods with vat dyes can be used, for example, potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, phosphoric acid, and the like. The use of potassium, sodium phosphate and the like is preferred. Further, as the reducing agent, hydrosulfite, thiourea dioxide,
Sodium sulfide, glucose, buttow and the like can be used, but hydrosulfite is most preferred.

[0016]

Next, an embodiment of the present invention will be described.
The present invention is not limited by these examples. The dye used in the examples (Mikethren Red F-
2B) is a vat dye manufactured by MITSUI BASF DYES LIMITED, and the inert gas (nitrogen gas) replacement ratio is indicated by volume%.

[0017]

EXAMPLES Example 1 A rayon woven fabric previously refined was dyed using a dyeing tester minicolor type 16 (Texam Giken's closed type dyeing machine). First, a vat dye, an alkali agent, a reducing agent and a cloth to be dyed prepared for dyeing are put into a dyeing pot (capacity: 400 ml), and then nitrogen gas is blown for 30 seconds while immediately closing the lid (replacement with nitrogen gas). (Ratio: 92-94%), dyeing, cooling, washing with water, oxidation treatment, washing with water, soaping, washing with water and drying. The staining conditions are as follows. Dyeing formula: Mikethren Red F-2B 4% (owf). Sodium hydroxide (30 ° Be) 28 cc / l. Hydrosulfite conch or thiourea dioxide 5, 7, 9 g / l. Glauber's salt (anhydrous) 20 g / l Bath ratio: 1:20 Dyeing temperature: 40, 60, 80 ° C. Dyeing time: 30 minutes Cooling temperature: Cool down to 30 ° C. after dyeing Oxidation method: Hydrogen peroxide (35%) 8 cc / l. Acetic acid (90%) 3 cc / l. 60 ° C x 10 minutes Soaping method: Meisanol KHM (a surfactant for soaping manufactured by Meisei Chemical Industry) 2 g / l. 90 ° C x 10 minutes

Comparative Example 1 The same method as in Example 1 was carried out under the condition without nitrogen gas replacement.

[Evaluation Results 1] The dyeing properties of Example 1 and Comparative Example 1 are compared and shown in Tables 1, 2, and 3. The dyeing ratio was determined by measuring the reflectance of each dyed cloth using a digital color difference meter, and ΔF (T) = F (X) + F (Y) + F (Z) from the obtained tristimulus values.
Was calculated, and the relative dyeing rate was calculated from the following formula. Dyeing rate (%) = {F (T) of dyed cloth under each condition / {F (T) of standard dyed cloth} × 100 The standard dyed cloth is dyeing temperature 60 ° C., dyeing time 30 minutes, hydrostatic Sulfite conc 5 g / l, sodium hydroxide (30 ° Be) 28 cc / l, bath ratio 1:20,
Dyeing was performed under the condition of replacing with nitrogen gas, and subsequently, oxidized and soaped by the method of Example 1 was used.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

[Table 3]

Example 2 A polynosic fiber woven fabric previously refined was dyed using the same dyeing machine as in Example 1 under the following conditions. However, the order of the nitrogen gas replacement method, the oxidation method, the soaping method, and the dyeing process was the same as in Example 1.
The same conditions were used. Dyeing formula: Dye 4, 15% (owf). Sodium hydroxide (30 ° Be) 20 cc / l. Hydrosulfite conc 3, 6, 9 g / l. Glauber's salt (anhydrous) 10, 20 g / l Bath ratio: 1:20 Dyeing temperature: 60 ° C. × 30 minutes Cooling temperature: Cool down to 30 ° C. after dyeing Dye name, dye concentration, sodium hydroxide (30 ° Be)
Table 4 shows the concentration and the concentration of sodium sulfate.

[0024]

[Table 4]

[Comparative Example 2] An experiment similar to that of Example 2 was performed under the condition that the nitrogen gas was not replaced.

[Evaluation Result 2] The dyeing properties (pill-up property and leveling property) of Example 2 and Comparative Example 2 are compared and shown in Table 5. 2-1) Build-up evaluation The relative dyeing rate was calculated in the same manner as in Evaluation result 1. However, as a standard dyed cloth, each dye has a dyeing temperature of 60.
° C, dyeing time 30 minutes, hydrosulfite conc 9g
/ L, sodium hydroxide (30 ° Be) 20 cc / l, bath ratio 1:20, dyeing with nitrogen gas replacement,
A cloth oxidized and soaped by the method of Example 1 was used.

[0027]

[Table 5]

2-2) Evaluation of levelness Example 2 and Comparative Example 2 The surface of the dyed cloth was visually observed,
The levelness was evaluated. Table 6 shows the results of levelness comparison.

[0029]

[Table 6]

Example 3 A polyamide fiber cloth (nylon jersey) which had been subjected to a refining treatment was dyed using the same dyeing machine as in Example 1 under the following conditions. However, the order of the nitrogen gas replacement method, the oxidation method, the soaping method, and the dyeing step was performed under the same conditions as in Example 1. Dye: Mikethren Red F-2B s / f 4% (owf). Mikethren Blue BC s / f 4% (owf) Dye 4% (owf). Sodium hydroxide (30 ° Be) 20 cc / l. Hydrosulfite conc 3,5 g / l. Glauber's salt (anhydrous) 10 g / l Bath ratio: 1:20 Dyeing temperature: 60 ° C, 80 ° C Dyeing time: 30 minutes Cooling temperature: After dyeing at each temperature, cool down to 30 ° C

Comparative Example 3 The same experiment as in Example 3 was carried out under the condition without nitrogen gas replacement, and the dyeability was examined.

[Evaluation Result 3] Table 7 shows a comparison of the dyeability of Example 3 and Comparative Example 3 as a relative dyeing ratio obtained by the same method as in Evaluation Result 1. However, as the standard dyed cloth, dyeing temperature 80 ° C., dyeing time 30 minutes, hydrosulfite conc 5 g / l, sodium hydroxide (30 ° Be) 20c
The fabric was dyed under the conditions of c / l, bath ratio of 1:20 and nitrogen gas replacement, and subsequently oxidized and soaped by the method of Example 1.

[0033]

[Table 7]

Example 4 Tencel fabric which had been subjected to a refining treatment was dyed using the same dyeing machine as in Example 1 under the following conditions. The order of the nitrogen replacement method, the oxidation method, the soaping method and the dyeing step was performed under the same conditions as in Example 1, but the nitrogen replacement ratio of the gas phase in the dyeing pot was 0.
%, 30-32%, 50-52%, 70-72%, 85
８７87%, 90-94%. Dyeing formula: Mikethren Blue BC s / f 4% (owf). Sodium hydroxide (30 ° Be) 20 cc / l. Hydrosulfite conc 5 g / l. Glauber's salt (anhydrous) 10 g / l Bath ratio: 1:20 Dyeing temperature: 60 ° C x 30 minutes Cooling temperature: Cool down to 30 ° C after dyeing

[Evaluation Result 4] The dyed cloth obtained in Example 4
Table 8 shows the relative dyeing ratio obtained in the same manner as in Evaluation result 1. However, as a standard dyed cloth, a dyeing temperature of 60 ° C., a dyeing time of 30 minutes, hydrosulfite conc 5 g / l,
Sodium hydroxide (30 ° Be) 20 cc / l, bath ratio 1:
20, using a cloth which was dyed under the condition of replacing with nitrogen gas and subsequently oxidized and soaped by the method of Example 1.

[0036]

[Table 8]

Example 5 A rayon fabric which had been subjected to a refining treatment was dyed using the same dyeing machine as in Example 1 under the following conditions. However, nitrogen gas replacement method, oxidation method,
The soaping method and the order of the dyeing steps were performed under the same conditions as in Example 1. Dyeing formula: Dye 4% (owf). Sodium hydroxide (30 ° Be) 20 cc / l. Hydrosulfite conc 5 g / l. Glauber's salt (anhydrous) 10 g / l Bath ratio: 1:20 Dyeing temperature / time: 60 ° C x 30 minutes Cooling temperature: Cool down to 30 ° C after dyeing

[Evaluation Result 5] The fastness of the rayon fabric dyed under the conditions of Example 5 was evaluated. Table 9 shows the results. Fastness evaluation method Light fastness: JIS L 0842 Carbon arc lamp (63 ° C,
20 hours) Friction fastness: JIS L 0849 (dry, wet) Sweat fastness: JIS L 0848 (Method A) Washing fastness: JIS L 0844-86 (A-2 method) Color fastness to chlorine bleaching: JIS L 0856-1995

[0039]

[Table 9]

[0040]

According to the present invention, a fiber product comprising rayon, cupra, polynosic fiber, tencel, lyocene, polyvinyl alcohol fiber and polyamide fiber is produced.
Using vat dyes, dyeing with excellent build-up properties, reproducibility and levelness, and excellent light fastness, chlorine fastness, and wet fastness (washing fastness, sweat fastness, wet rub fastness) Is possible.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Saori 1-floor Nakazawacho, Nishikyogoku, Ukyo-ku, Kyoto, Kyoto Prefecture F-term (reference) 4H057 AA02 BA09 CA03 CA08 CA11 CA90 CB34 CB48 CB55 CB60 CC02 DA01 DA22 DA24 DA29 DA34 HA08 HA19

Claims (2)

[Claims] 1. Dyeing a textile product selected from the group consisting of rayon, cupra, polynosic, tencel, lyocell, polyvinyl alcohol-based fiber and polyamide-based fiber with a vat dye in the presence of an alkali agent and a reducing agent. A dyeing method using a vat dye, wherein an inert gas is used and air in a gas phase portion of the dyeing machine is replaced with an inert gas by 30% or more. 2. The method according to claim 1, wherein the replacement ratio of said gas phase portion by an inert gas is 70% or more.