KR20030097245A - Alkali-clearable azo disperse dyes containing fluorosulfonyl group and preparing method thereof and dyeing method thereby - Google Patents

Abstract

PURPOSE: Provided are an azo-based alkali-clearable disperse dye containing fluorosulfone, which has clearing ability under a weak alkali condition after dyeing polyester fiber material, and a method for dyeing the polyester fiber material by using the alkali-clearable dispersing dye, which can omit a reduction clearing process. CONSTITUTION: The azo-based alkali-clearable disperse dye containing the fluorosulfone is an azobenzene-based monoazo compound(formula I) and is produced by coupling-reacting a diazonium salt(formula II) of an aromatic amine compound with an aromatic aniline-substituted monoazo intermediate compound (formula III) as a coupling component, wherein X1, X2, and X3 are hydrogen, nitro, chloro, bromo, or cyano, Y1 and Y2 are hydrogen, methyl, methoxy, or acetylamino, and R1 and R2 are substituted or unsubstituted alkyl. And the method for dyeing the polyester fiber material uses the disperse dye(formula I) and performs an alkali clearing instead of the reduction clearing.

Description

Alkali-clearable azo disperse dyes containing fluorosulfonyl group and preparing method about and dyeing method hence

The present invention relates to an azo alkali cleansing disperse dye having a fluorosulfone group. More specifically, the chemical structure has a fluorosulfone group at the 4'- position of the azo group. The present invention relates to an alkaline-cleaning azo dispersant which not only replaces the existing non-environmentally friendly reducing cleaning process but also enables one-bath dyeing of polyester / cotton blend fiber materials.

Conventional azo disperse dyes have been widely used to dye fiber materials, in particular fiber materials such as polyester fibers. However, these known dyes required a reduction and washing process using a strong alkali and a strong reducing agent after dyeing in order to obtain high fastness in terms of fastness of a product dyed by dyeing methods such as vacuum dyeing.

In general, various types of disperse dyes are known which are useful for dyeing polyester fiber materials. For example, Japanese Patent Application Nos. 41-5468 and 55-152873 disclose violet and blue disperse dyes represented by the following formulas.

The Color Index provided by the Society of Dyers and Colourists (SDC) and the American Association of Textile Chemists and Colorists (AATCC) includes the red-based disperse dye, CIDisperse Red 7 (Constitution No. 11150) , CI Disperse Red 13 (Constitution No. 11115), C.I. Disperse Red 17 (Constitution No. 11210) is published.

In addition, when using a conventional dispersion dye in dyeing polyester / cotton blend fiber material, a two-bath dyeing process is used to obtain high fastness. In other words, in the first salt bath, the polyester material is dyed at 130 ° C. using a disperse dye, and after being washed with reduction, the second dye bath is used to dye the cotton material at around 80 ° C. using a reactive dye.

In general, in order to obtain excellent fastness when dyeing polyester fiber material with a disperse dye, it is subjected to reduction clearing (Reduction clearing) process as a post-dyeing treatment. In general, a reduction washing process is performed at about 80 ° C by administering hydrosulfite (Na ₂ S ₂ O ₄ ), which is a strong reducing agent, and sodium hydroxide (NaOH), which is a strong alkali, to assist in the stability of the reducing agent. Will be processed for about 20 minutes. In this way, as shown in the reaction scheme below, in the case of the azo dispersion dye, the reducing agent destroys the azo bonds in the molecular structure to discolor and at the same time loses the affinity for the polyester fiber, thereby removing the unfixed dyes on the fiber surface. Later fastness can be improved. Therefore, in the case of the existing azo-based dyes, the reduction and washing process after dyeing is essential for excellent fastness.

Such a conventional dispersion dye has a problem that the BOD and pH in the dyeing wastewater is inevitably raised by using a strong reducing agent and strong alkali during the post-reduction washing after dyeing. In addition, when the azo groups in the disperse dye structure are decomposed during the reduction and washing, the reduced dye remains in the fiber or dye wastewater to produce an aromatic amine compound, and due to the strong oxidizing property of the amine compound, It was a cause for deterioration.

On the other hand, the AT Leaver group of the aromatic amine compound (a) originating from the diazo compound among the aromatic amines generated during the reduction cleaning, the basicity of the aromatic amine is weakened by the action of the electron withdrawing group Although environmental toxicity or human toxicity is insignificant, the aromatic amine compound (b) generated from the coupling component has a chemical structure very similar to that of benzidine or phenylenediamine. Eggplants have been reported to be carcinogenic (Text. Chem. Color., Vol. 24, p18, 1992).

On the other hand, even in the dyeing of polyester / cotton blend fiber materials, when using the conventional disperse dyes, a two-bath dyeing method must be used for high fastness, this dyeing method not only consumes a lot of energy required for dyeing water and heating There was a drawback of inefficiency due to the large amount of preparation and the long dyeing process.

Accordingly, the present inventors have extensively studied disperse dyes to improve the drawbacks of the known dyes described above and satisfy the requirements for dyes, and have therefore developed a special azo-based disperse dyes having alkali cleaning properties of the present invention.

It is an object of the present invention not only to replace the existing reduction and washing process by washing in weak alkali conditions after dyeing polyester fiber material, but also to make one bath dyeing method for polyester / cotton blend fiber material. To provide crude disperse dyes.

Another object of the present invention is to provide a method for preparing a new alkaline-cleaning azo-based dispersion dye.

It is still another object of the present invention to provide a dyeing method of polyester fiber material, which can omit the reduction washing with a strong alkaline solution by using a new alkaline-cleaning azo-based dispersion dye.

Still another object of the present invention is to provide a dyeing method of a polyester / cotton blend fiber material capable of omitting reduction washing with a strong alkaline solution with a new alkaline-cleaning azo-based dispersion dye and capable of one bath dyeing.

1A is a dyeing diagram for dyeing a polyester component in a two bath dyeing method of a conventional polyester / cotton blend fiber material.

1B is a dyeing diagram for dyeing cotton components in a two bath dyeing method of a conventional polyester / cotton blend fiber material.

FIG. 2 is a dyeing diagram showing a one-bath dyeing method of a polyester / cotton blend fiber material using a dispersion dye having a fluorosulfone group of the present invention.

The azo alkali cleansing disperse dye having a fluorosulfone group according to the present invention is characterized by being an azo benzene monoazo compound having the following structural formula (I).

(I)

Wherein X ¹ , X ² and X ³ are hydrogen, nitro, chloro, bromo or cyano groups, Y ¹ and Y ² are hydrogen, methyl, methoxy or acetylamino groups, and R ¹ and R ² are each unsubstituted. Or a substituted alkyl group.

The method for producing an alkaline-cleaning disperse dye according to the present invention is a coupling reaction between a diazonium salt of an aromatic amine compound represented by the following structural formula (II) and an aromatic aniline compound which is a coupling component represented by the following structural formula (III). It is characterized by obtaining the compound of formula (I) through.

(II)

(III)

Wherein X ¹ , X ² , X ³ ,, Y ¹ , Y ² , R ¹ and R ² are the same as in formula (I).

The dyeing method of the polyester fiber material using the azo alkali-cleaning disperse dye having the fluorosulfone group of the present invention uses a dye of the above formula (I) in ordinary polyester high temperature and high pressure dyeing, Instead of omitting the reduction and washing step, it is characterized by performing alkaline washing with a weak alkaline solution.

The alkali used in the alkaline solution may include weak alkalis such as sodium carbonate (Na ₂ CO ₃ ) and sodium hydrogen carbonate (NaHCO ₃ ), and sodium carbonate is preferable in consideration of the pH range required for alkali cleaning. It is also possible to use a small amount of sodium hydroxide, which is a strong alkali, instead of weak alkali.

In addition, the dyeing method of the polyester / cotton blend fiber material using the azo-based alkaline washable disperse dye having a fluorosulfone group of the present invention, the dye and reactive dye of the formula (I) and the dispersant, forget-me-not and acetic acid in water Dyeing the polyester portion by heating to 120 to 140 ° C. according to a conventional polyester high temperature and high pressure dyeing method, and maintaining the dyeing portion for 20 to 60 minutes, lowering the temperature to 70 to 90 ° C., and then normal reactivity. Dyeing the cotton portion according to the method of dyeing the cotton with a dye, it is characterized in that it comprises the step of alkali cleaning (alkali clearing) at the same time while maintaining the temperature for 20 to 60 minutes by administering sodium alkali which is a weak alkali.

Alkali employed in the alkaline solution may be a small amount of sodium carbonate (Na ₂ CO ₃ ), weak alkali of sodium hydrogen carbonate (NaHCO ₃ ), or sodium hydroxide, which is a strong alkali, but the pH range required for dyeing cotton fibers and alkali cleaning, It is preferable to use sodium carbonate, which is a weak alkali, in consideration of the disproportionation of cotton fibers due to rapid dye absorption.

The present invention will be described in more detail below.

The azo alkali cleansing disperse dye having a fluorosulfone group according to the present invention is an azo benzene monoazo compound having the following structural formula.

(I)

Wherein X ¹ , X ² and X ³ are hydrogen, nitro, chloro, bromo or cyano groups, Y ¹ and Y ² are hydrogen, methyl, methoxy or acetylamino groups, and R ¹ and R ² are each unsubstituted. Or a substituted alkyl group. The present invention provides a method of obtaining high fastness by a weak alkali treatment after dyeing a polyester fiber material using the monoazo compound represented by the formula (I).

The disperse dye of the present invention is an azo-based disperse dye having a fluorosulfone group in its chemical structure, so that the fluorosulfone group is hydrolyzed under relatively weak alkali conditions to give a water solubility to the dye as it is changed to a sulfone group, thereby making it dyeable. After the dye is unfixed to the fiber is dissolved in the water by alkali cleaning, it is eliminated from the fiber to increase the dyeing fastness of the product.

The compound of formula (I) may be obtained through a coupling reaction between a diazonium salt of an aromatic amine compound represented by the following formula (II) and an aromatic aniline compound which is a coupling component represented by the following formula (III). .

(II)

(III)

Wherein X ¹ , X ² , X ³ ,, Y ¹ , Y ² , R ¹ and R ² are the same as in formula (I).

Diazonium salts of the aromatic compounds are applied directly to sulfonated amines that are well dissolved in strong basic amines and acidic solutions: NaNO ₂ , HCl, 0-5 ° C. or nitrosulfic acid method (applied to weakly basic amines: NaNO ₂ , H ₂ SO ₄ , 0-5 ° C.), etc., to obtain a compound of formula (I) through a coupling reaction at 0-5 ° C. with an appropriate coupling component.

The dyeing method of the polyester fiber material of the present invention is the same condition as the normal polyester high temperature and high pressure dyeing, but using the dye of the formula (I), instead of omitting the reducing cleaning process by strong alkali and reducing agent, weak alkali It is a characteristic to perform alkaline washing with a solution.

Polyester fiber materials can be dyed only by hydrophobic disperse dyes that do not have dyeing seats that can react with common dyes due to the physical and chemical properties of the raw materials and are generally hydrophobic and have no hydrophilic groups.

The dyeing of the polyester fiber material may be made by an appropriate method, and may be dyed by conventional methods, for example, high temperature high pressure dyeing, thermosol dyeing or carrier dyeing, depending on the physical and chemical properties of the material. At present, high temperature and high pressure dyeing is most commonly used.

High temperature and high pressure dyeing is generally performed under high temperature and high pressure of 130 ° C or higher, and is dyed under weakly acidic condition of pH 4-5 using a dispersant to help disperse the dye in water.

In the reduction and washing process, which is used as a post-treatment of conventional polyester fiber materials, it is generally treated with sodium hydroxide about 2.0 g / l and hydrosulfite about 2.0 g / l and then treated at 80 ° C. for about 20 minutes. However, the sodium hydroxide used at this time is a strong alkali to increase the pH and BOD in the dyeing wastewater, hydrosulfite as a strong reducing agent has a problem of destroying azo groups in the dye molecule structure to produce carcinogenic amines. The present invention solves this problem by employing a special monoazo dye to replace the existing non-environmentally friendly reducing cleaning process with a weak alkali.

The dye of the present invention does not need to use a strong reducing agent that is harmful to the environment in which it is commonly used, and by using weak alkali instead, it is possible to obtain excellent fastness through sufficient cleaning property.

The alkali cleaning may be performed for 10 to 40 minutes at a temperature of 70 to 95 ° C., and the cleaning temperature and time may be understood to be similar to reduction clearing conditions in a conventional dyeing process.

The weak alkali that can be used for the alkali cleaning is not particularly limited as long as it can give a value of about pH 11-12, and examples of the weak alkali include sodium carbonate (Na ₂ CO ₃ ) and sodium hydrogen carbonate (NaHCO ₃ ). Can be mentioned. However, considering the efficiency of alkali cleaning, the use of sodium carbonate is particularly recommended, and the use of sodium hydroxide (0.5-1.0 g / l) is recommended if a small amount of strong alkali is used instead to reduce the process cost.

The dyeing method of the polyester / cotton blend fiber material of the present invention is prepared by adding a dye and a reactive dye of the formula (I), a dispersant, a forget-me-not and acetic acid to water to make a salt bath, and then in accordance with a conventional polyester high-temperature high-pressure dyeing method. Dyeing the polyester portion while maintaining the temperature at 120 to 140 ° C. for 20 to 60 minutes, lowering the temperature to 70 to 90 ° C., and then dyeing the cotton part according to a conventional dyeing method using a reactive dye. Sodium carbonate is administered to maintain the temperature for 20 to 60 minutes, and dyeing and alkali clearing are performed at the same time.

2 is a process diagram for the one-bath dyeing method of the present invention, showing a specific dyeing example.

The dyeing of polyester / cotton blend fiber material conventionally performed is performed by a two-bath dyeing method, as shown in FIGS. 1A and 1B, and a polyester material at 130 ° C. using a disperse dye in a first dye bath. In the second salt bath, the dyeing material is dyed and the cotton is dyed at 80 ° C. using a reactive dye. At this time, it is common to add a weak alkali sodium carbonate to fix the reactive dye to the cotton fiber.

The reason why two baths were dyed when dyeing conventional polyester / cotton blend fabrics was that when the reducing washing solution was used in the same bath with the reactive dyes, the reactive dyes were decomposed by the reducing agent and the dyeing of the cotton fibers was inhibited. This is because staining results cannot be obtained.

However, in the case of using the alkali-cleaning disperse dye of the present invention, the addition of alkalis to the washing of the unfixed dyes on the surface of the fiber and the reactive dyes can be fixed to the cotton fibers at the same time. Instead of inefficient two-bath dyeing, an efficient and economical one-bath dyeing is possible.

In the present invention, conditions such as temperature and time for polyester dyeing, temperature and time for cotton dyeing are not the only features of the present invention, but are the same as those of ordinary cotton dyeing by ordinary high-temperature high-pressure dyeing and reactive dyes. It may be understood, and other process conditions not specifically mentioned may be the same. Therefore, the reason for the upper and lower limits for the temperature and time conditions need not be specified.

In the dyeing of the blended fiber material of the present invention, the forget-me-not, dispersant, acetic acid to be used is usually used when dyeing polyester or cotton, it can be easily understood by those skilled in the art that the dosage can be adjusted according to the purpose and type of dyeing. Could be.

The dyeings dyed with the dyes of the present invention are excellent in light fastness, sweat fastness, washing fastness and friction fastness by weak alkali cleaning after dyeing under the above conditions, and the dyes of the present invention have extremely excellent build-up properties. It has good leveling, leveling and washing resistance, and has a high rate of dust absorption.

Hereinafter, specific examples and comparative examples of the present invention will be described, but the following examples are only for illustrative purposes and should not be understood as limiting the scope of the present invention.

EXAMPLE

Examples 1 to 3 (dye synthesis)

After dissolving 89.5 g of potassium fluoride in a mixture of 120 ml of 4-dioxane and 120 ml of water, 60 g of N -acetylsulfanyl chloride was added and dispersed, followed by stirring under cooling reflux at a boiling point. After the reaction for 3 hours, the reaction was poured into ice to form a white solid, which was washed with water and filtered to obtain fluorsulfonylaniline represented by the following formula.

The diazonium compound thus obtained was diazotized into the synthesized fluorosulfonylaniline by conventional methods, and N , N -diethylaniline, N , N -diethyl-meth-toluidine and N- (3-diethylamino- Coupling with 4-methoxy-phenyl) -acetamide, respectively, afforded the monoazo compound, dye 1, dye 2 and dye 3 of the present invention represented by the following formula.

Examples 4-6 (Dye Synthesis)

21.72 g of N -acetylsulfanyl fluoride was dissolved in 120 ml of concentrated sulfuric acid (98%), cooled to 4 ° C, and 12.7 ml of concentrated nitric acid (70%) dissolved in 14 ml of concentrated sulfuric acid (98%) was 4-6 ° C. Add slowly while maintaining. After 1 hour of reaction, the reaction was poured into ice to form a yellow precipitate, washed with water sufficiently and filtered to obtain N -acetyl-2-nitrosulfanyl fluoride.

The diazonium compound produced by diazotizing the thus-synthesized N -acetyl-2-nitrosulfanyl fluoride by the conventional method was prepared in the same manner as in Examples 1 to 3 with N , N -diethylaniline, N , N -di Coupling with ethyl-meth-toluidine and N- (3-diethylamino-4-methoxy-phenyl) -acetamide, respectively, afforded a monoazo compound, dye 4, dye 5 and dye 6 represented by the following formula.

Examples 7 to 9 (Dye Synthesis)

10 g of 2-nitro-4-fluorosulfonylaniline was dispersed in 51 ml of 37% hydrochloric acid, cooled to 0-5 ° C., and 5.85 g of sodium chlorate dissolved in 8.0 ml of water was slowly added while maintaining 0-5 ° C. Let's do it. After 2 hours, the reaction was poured into ice to form a yellow solid, which was washed with water and filtered to obtain 2-nitro-4-fluorosulfonyl-6-chloroaniline represented by the following formula.

The diazonium compound produced by diazotizing the thus-synthesized 2-nitro-4-fluorosulfonyl-6-chloroaniline by the conventional method was prepared in the same manner as in Examples 1 to 3, and N , N -diethylaniline, N , Mono-azo compound, dye 7, dye 8, dye represented by the following formula by coupling with N -diethyl-meth-toluidine and N- (3-diethylamino-4-methoxy-phenyl) -acetamide, respectively Got 9.

Examples 10 to 12 (Dye Synthesis)

10 g of 2-nitro-4-fluorosulfonylaniline was dispersed in 100 ml of glacial acetic acid, and then 2.80 ml of bromine was added and the temperature was raised to 75 ° C. After the reaction for 2 hours, the reaction was poured into ice to form a yellow solid, which was washed with water and filtered to obtain 2-nitro-4-fluorosulfonyl-6-bromoaniline represented by the following formula.

The diazonium compound produced by diazotizing the thus-synthesized 2-nitro-4-fluorosulfonyl-6-chloroaniline by the conventional method was prepared in the same manner as in Examples 1 to 3, and N , N -diethylaniline, N , Mono-azo compounds, dyes 10, dyes 11 and dyes which are coupled by N -diethyl-meth-toluidine and N- (3-diethylamino-4-methoxy-phenyl) -acetamide, respectively, 12 was obtained.

Examples 13-15 (Dye Synthesis)

The dyes 10 and 4 mmol are dissolved in 20 ml of dimethylformamide (DMF), and 4.8 mmol of copper cyanide (CuCN) is added and the temperature is raised to 90 ° C. After the reaction for 3 hours, the reaction product was poured into ice to form a blue solid, which was washed with water and filtered to obtain a monoazo compound, a dye 13, a dye 14, and a dye 15 represented by the following formula.

Examples 16 to 30 (Dyeing of Polyester Fiber Materials)

Each monoazo compound obtained in Examples 1 to 15 was dispersed in 60 ml of water to which 0.5 g / l of a dispersant (surfactant for dye dispersion) was added at 1% owf, and a polyester fiber material was added thereto. The pH of the salt bath was adjusted to 4.0 ~ 4.5 using acetic acid.

The dye bath was heated up to 130 ° C. and maintained for 60 minutes to perform dyeing. After dyeing, the dyeing material was added to 60 ml of an alkaline washing bath containing 20 g / l of soda ash and 1.0 g / l of a soap for soaping, and then dried at 80 ° C. for 20 minutes.

In this manner, as in the conventional dyeing after reduction and dyeing, dyeings having excellent fastnesses such as water fastness, sweat fastness, daylight fastness, friction fastness and sublimation fastness were obtained. In addition, the dyes of the present invention exhibited excellent build-up, leveling and washing resistance, and a high rate of absorption. (Laundry Fastness KS K 0430; Grade 4 / 5-5, Sunlight Fastness KS K 0700; 4-5 Grade, iron fastness KS K 0637; grades 4 to 4/5, frictional fastness KS K 0650; grades 4/5 to 5).

Examples 31 to 45 (one bath dyeing of polyester / cotton blend fiber material)

0.5 g / l of a dispersant (surfactant for dye dispersion) and manganese (1% owf) of each monoazo compound obtained in Examples 1 to 15 and a general commercially available reactive dye having a high temperature stability (monochlorotriazine type) as 1% owf, respectively Na ₂ SO ₄ ) was dispersed and dissolved in 60 ml of water to which 80 g / l was added, and a polyester / cotton blend fiber material was added thereto. The pH of the salt bath was adjusted to 4.5 ~ 5.0 using acetic acid.

The dye bath was heated up to 130 ° C. and held for 30 minutes to dye the polyester component and cooled to 80 ° C. at a rate of 2 ° C./min, followed by 20 g / l of alkali (soda ash) immediately after cooling and twice for 10 minutes after cooling. Cotton dyeing with a reactive dye was carried out by dividing into a portion. After the addition of alkali, the fiber was further maintained at 80 ° C. for 30 minutes for the homogenization of the fiber material, and the dyeing was finished. After dyeing, the dye was washed with water at 70 ° C. for 10 minutes, at 95 ° C. for 20 minutes (1.0 g / l of sodium carbonate) and then at 70 ° C. for 10 minutes, and then treated at 80 ° C. for 20 minutes, and then dried by cold water. (See Figure 2)

In this way, a dyeing product having excellent fastnesses such as flush fastness, sweat fastness, daylight fastness, friction fastness and sublimation fastness can be obtained like the dyeing dyeing by the two-bath dyeing method, which is a conventional dyeing method of polyester / cotton blend fiber material. Could. (Laundry Fastness KS K 0430; Grade 4 / 5-5, Friction Fastness KS K 0650; Grade 4 / 5-5).

When the dye having a fluorosulfone group of the present invention is used for the dyeing of the polyester fiber material, it is possible to replace the existing reduction washing process with an alkaline washing process in order to obtain high fastness after dyeing. This will not only alleviate the high pH and BOD problems in the dyeing wastewater caused by the use of reducing cleaning fluids, but also prevent the development of carcinogenic aromatic amines in an environmentally friendly way. The processing method becomes possible.

In addition, an efficient and economical one-bath dyeing method is also possible in dyeing polyester / cotton blend fiber materials. This reduces the amount of dyeing water (50-55%) and the amount of preparation used, compared to the existing two-bath dyeing process, energy savings and dyeing process time (40-50%) can be expected.

Although the present invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and such modifications and variations belong to the appended claims. .

Claims (6)

It is an azo benzene-type monoazo compound which has the following structural formula (I), The azo-type alkali washable dispersion dye which has a fluoro sulfone group characterized by the above-mentioned. (I) Wherein X ¹ , X ² and X ³ are hydrogen, nitro, chloro, bromo or cyano groups, Y ¹ and Y ² are hydrogen, methyl, methoxy or acetylamino groups, and R ¹ and R ² are each unsubstituted. Unsubstituted or substituted alkyl groups.) Structural formula (I) of Claim 1 through coupling reaction of the diazonium salt of the aromatic amine compound represented by following structural formula (II), and the aromatic aniline substituted monoazo intermediate compound which is a coupling component represented by following structural formula (III) A method for producing an azo alkali-cleaning disperse dye having a fluorosulfone group, wherein the compound is obtained. (II) (III) (Wherein X ¹ , X ² , X ³ ,, Y ¹ , Y ² , R ¹ and R ² are the same as in formula (I) of claim 1). In polyester high temperature and high pressure dyeing, the dye of the structural formula (I) of claim 1 is used, and instead of omitting the reduction washing step with a strong alkali solution, alkaline washing with a weak alkali solution is carried out. Dyeing method of polyester fiber material using azo alkali washable disperse dye. The dyeing method of polyester fiber material using the azo-type alkali washable disperse dye which has the said fluoro sulfone group of Claim 3 whose pH of the said weak alkali is 11-12. 5. The method for dyeing a polyester fiber material using an azo alkali-clean dispersing dye having the fluorosulfone group according to claim 4, wherein the weak alkali is sodium carbonate or sodium hydrogen carbonate. The dye and reactive dye of the formula (I) of claim 1, dispersant, forget-me-not and acetic acid are added to water to make a salt bath, and then heated to 120 to 140 ° C. according to a conventional polyester high temperature and high pressure dyeing method and maintained for 20 to 60 minutes. While dyeing the polyester portion, the temperature is lowered to 70 to 90 ℃ and then dyed cotton portion according to the conventional dyeing method using a reactive dye, while maintaining the temperature for 20 to 60 minutes by administering a weak alkali sodium carbonate A dyeing method of a polyester / cotton blend fiber material using an azo alkali-cleaning disperse dye having a fluorosulfone group, characterized in that the step of performing alkali cleaning at the same time as dyeing.