CN103911018B - A kind of prepare directly red 253 method - Google Patents

Abstract

Prepare a method of directly red 253, relate to a kind of preparation method of dyestuff, the present invention has synthesized this dyestuff by experimental procedures such as diazonium, a contracting, coupling, two contractings, three contractings.Directly red 253 is a kind of substantive dyestuff containing triazine ring, and this kind of dye molecule containing triazine ring substantive dyestuff molecular structure can keep certain linear planar structure, and have good avidity to cellulosic fibre, sunlight fastness is also better.And this kind of dyestuff does not have carinogenicity, belongs to environmental protection type dye, be therefore develop more substantive dyestuff in recent years.This dyestuff has stronger dyeing capacity, effectively can reduce the discharge of colorful wastewater, save energy, be conducive to the protection of ecotope, meets the principle of environmental protection type dye exploitation.

Description

A kind of method for preparing direct red 253

technical field

The invention relates to a method for preparing a dye, in particular to a method for preparing Direct Red 253.

Background technique

With the application and development of vat dyes and reactive dyes, the importance of direct dyes has declined, but there are still many applications so far. Among the dyes used for dyeing cellulose fibers in 2006, the amount of direct dyes accounted for about 18%. In recent years, with the restrictions on dyes containing carcinogenic aromatic amines in the relevant regulations of ecological textiles, the development of environmentally friendly direct dyes is the focus of the current development of direct dyes.

With the strengthening of environmental protection awareness and the increasing requirements for product quality, direct dyes with relatively good dyeing performance and environmental protection are the focus of current research on reactive dyes. Direct Red 253 is a direct dye containing triazine rings. The molecular structure of direct dyes containing triazine rings can maintain a certain linear planar structure. It has a good affinity for cellulose fibers and is resistant to sunlight. The fastness is also good. Moreover, this kind of dye has no carcinogenicity and is an environmentally friendly dye, so it is a direct dye that has been developed more in recent years.

Contents of the invention

The object of the present invention is to provide a method for preparing Direct Red 253. The method synthesizes the dye through experimental steps such as diazo, one shrinkage, coupling, two shrinkage, and three shrinkage. Direct Red 253 is a triazine ring-containing It is a direct dye, which has a strong dyeing ability, can effectively reduce the discharge of colored wastewater, save energy, is conducive to the protection of the ecological environment, and is in line with the principle of the development of environmentally friendly dyes.

The purpose of the present invention is achieved through the following technical solutions:

A method for preparing Direct Red 253, said method comprising the following preparation steps:

a) In a 250mL three-necked flask, add 2.6mL concentrated hydrochloric acid and 7.4mL water, and control the temperature at 29~31°C; add 1.47g (0.0053mol) of 4-aminoazobenzene-4'-sulfonic acid to a small beaker Dissolve 10mL of water and stir evenly, adjust the pH of the solution to 7~8 with 10% Na2CO3 solution, then add 2.6mL (0.1mol) sodium nitrite solution, stir well, and gradually drop the mixed solution into a three-necked flask containing hydrochloric acid and water In the middle, carry out the diazotization reaction, about 0.5 ~ 1h drop, and then react for 2.5 ~ 3h, use starch potassium iodide test paper to detect whether the end point is reached, if there is excessive sodium nitrite in the reaction solution, use 10% sulfamic acid The solution is destroyed, the reaction is over, and the product is ready for use;

b) Weigh 1.33g (0.0056mol) of J acid, adjust the pH of the J acid solution between 6 and 7 with 10% Na2CO3 solution, and wait until the J acid becomes clear; take 0.92g (0.0051mol) of cyanuric chloride, add About 10~15ml of water, the temperature is kept at 0~5℃, after the pH drops to 1.5~2, slowly add the clear J acid into the cyanuric chloride solution, and the time of dropping J acid is controlled at 4~5 Hours, the reaction is over, ready for use;

c) Adjust the temperature of the b reaction product to 15~20°C, adjust the pH between 6~6.5 with 10% Na2CO3, then add the a reaction product dropwise to the mixture, and react for about 1.5~2 hours. After the reaction is complete, continue After reacting for 0.5h, the end point of the reaction is reached;

d) Control the temperature of coupling product c at 10°C, weigh 0.365g (0.598mol) of ethanolamine and use 10%Na2CO3 solution to adjust the pH between 8 and 9, add it to coupling product c for condensation reaction, and add the materials After that, raise the temperature to 45~50℃, adjust the pH between 5~6 with 10% Na2CO3, and wait for the pH to be stable as the end point of the experiment, and the time is about 3~4 hours;

e) Control the temperature of the reaction product d between 45~50°C; weigh 0.365g (0.598mol) of ethanolamine and adjust the pH to 7~7.5 with 10% Na2CO3, add it to the dicondensate d, after the addition is complete Raise the temperature to 90~100℃, and the pH is basically stable as the end point, and the time is about 2.5~3 hours.

A described method for preparing Direct Red 253, the end point of the b reaction is detected with Errich reagent, and the reaction of J acid is completely used as the end point; Errich reagent is the acidic ethanol solution of p-dimethylaminobenzaldehyde, which can be mixed with aromatic amine , Hydrazine substance condensation, generate Schiff's base (schiffbase) and present color.

The method for preparing Direct Red 253, the specific operation for determining the end point of the c reaction is: use a glass rod to dip a drop of the reaction solution on the filter paper with a small amount of sodium chloride, and a colorless A small amount of diazo component and coupling component are dissolved in it; use p-nitroaniline diazonium salt solution to place a drop next to the moistening ring to form a moistening ring. If there is a coupling component, it will Red will be generated at the position; also use the newly configured H acid to detect the diazonium salt. If there is a diazonium salt, there will be red at the junction of the moist circle. The end point of the reaction is that there is no red at the junction when the H acid is detected. When the nitroaniline diazonium salt is detected, it is slightly red as the standard, that is, the slight excess of the coupling component is the reaction end point.

In the method for preparing Direct Red 253, the final dye is purified with sodium chloride. The specific method is as follows: dissolve the dye in deionized water, so that it is not too much, filter to remove impurities, and keep the filtrate. The filtrate is based on W/V =20% add sodium chloride for salting out, filter, then dissolve the filter cake with deionized water and salt out with sodium chloride, repeat this three times, then dry the filter cake to obtain a dye with higher purity.

Description of drawings

Figure 1 is a diagram of the molecular structure of Direct Red 253 dye.

detailed description

Below in conjunction with embodiment, the present invention is described in further detail.

The present invention synthesizes the dye through experimental steps such as diazo, one-shrink, coupling, two-shrink, three-shrink. The structural formula of the dye is shown in Figure 1. The dye has a strong dyeing ability, can effectively reduce the discharge of colored wastewater, save energy, and is conducive to the protection of the ecological environment, which is in line with the principle of the development of environmentally friendly dyes.

The method of the present invention comprises the following steps: a) Add 2.6mL of concentrated hydrochloric acid and 7.4mL of water into a 250mL three-neck flask, and control the temperature at 29-31°C. Dissolve 1.47g (0.0053mol) of 4-aminoazobenzene-4'-sulfonic acid in 10mL of water in a small beaker and stir evenly, adjust the pH to 7~8 with 10% Na2CO3 solution, then add 2.6mL (0.1mol ) sodium nitrite solution, stir well, gradually drop the solution into a three-necked flask with hydrochloric acid and water, and carry out diazotization reaction. Reach the end point, if there is excessive sodium nitrite, then destroy it with 10% sulfamic acid solution, the reaction is finished, and the product is ready for use; b) get 0.92g (0.0051mol) of cyanuric chloride, add about 10 ~ 15ml water, and the temperature is maintained at 0~5℃, after the pH drops to 1.5~2, add 1.33g (0.0056mol) of J acid, adjust the pH of the J acid solution to 6~7 with 10% Na2CO3 solution, and wait until the J acid becomes clear, add J The acid is added dropwise into the cyanuric chloride solution, and the time of adding the acid J is controlled at about 4 to 5 hours, and the reaction is completed; c) Adjust the temperature of the reaction product of b to 15~20°C, and adjust the pH at 6 with 10% Na2CO3 ~6.5, then add the reaction product of a to the mixture dropwise, and react for about 1.5~2 hours. After the reaction is complete, continue to react for 0.5h and reach the end of the reaction. d) Control the temperature of the coupling product c at about 10°C, weigh 0.365 g (0.598 mol) of ethanolamine and adjust the pH between 8 and 9 with 10% Na2CO3 solution, add it to the coupling product c for condensation reaction, add After the materials are finished, raise the temperature to 45~50°C, adjust the pH between 5~6 with 10% Na2CO3, and wait until the pH becomes stable as the end point of the experiment, and the time is about 3~4 hours. e) Control the temperature of the reaction product d between 45~50°C; weigh 0.365g (0.598mol) of ethanolamine and adjust the pH to 7~7.5 with 10% Na2CO3, add it to the dicondensate d, after the addition is complete Raise the temperature to 90~100℃, and the pH is basically stable as the end point, and the time is about 2.5~3 hours.

In the present invention, due to the high reactivity of cyanuric chloride in the b step, the lower its shrinkage reaction temperature, the less side reactions such as the hydrolysis of cyanuric chloride take place. However, if the temperature is too low, on the one hand, the energy consumption will be high, and on the other hand, the reaction rate will be slow and the reaction time will be long. Therefore, the appropriate reaction temperature should be kept at 0-5°C. The pH of the primary condensation reaction of cyanuric chloride is generally controlled at 2 to 2.5, because the catalytic effect of acid on the triazine ring can occur at a lower pH. The nitrogen atom on the triazine ring is protonated, thereby increasing the reactivity of the carbocation and accelerating the reaction rate of cyanuric chloride and amino. The time of the shrinkage reaction is generally completed in 1-3 hours according to the different reactivity of the amino compound. At the same time, the rate of addition of acid J in the reaction is generally controlled at 10 s/drop, because too fast addition will cause irreversible precipitation of acid J, and too slow addition will make the reaction time too long, which is not conducive to the reaction. In addition, the reaction rate is also affected by the concentration of reactants. The closer to the end point, the lower the concentration of reactants, the slower the reaction rate. Adding a small amount of cyanuric chloride before the end point can receive obvious time-saving effect. In order to ensure the complete reaction of amino compounds, an excess of cyanuric chloride is generally required to be 5-10% in the experiment, and the disappearance of J acid is detected as the end point of the reaction using Errich reagent.

In the present invention, in the coupling reaction, the acid-binding agent can neutralize the hydrochloric acid produced by the reaction, so as to promote the forward progress of the reaction. The present invention selects Na2CO3, NaHCO3, KHCO3, and NaH2PO4 four kinds of acid-binding agents, among which Na2CO3 is used as the acid-binding agent to obtain the highest coupling product yield, so the present invention uses Na2CO3 as the acid-binding agent.

Example 1:

Coupling reaction is an important factor affecting the yield of dyes. A set of experiments were done on the influence of feeding methods on the coupling yield. One is direct feeding, the other is partial feeding, and the temperature is controlled at the coupling pH at 6~7. between. Since the synthetic dye is a liquid dye. Therefore, in this experiment, the analysis of the coupling and condensation yield adopts the method of discounting the amount. Based on the first group of experimental data, use the following formula to obtain the relative yield of each group.

Calculation formula: discounted amount =

Among them, m1—mass of product/g

C1—absorbance of each group of products

C2—The absorbance results of the first group of products are shown in Table 1.1:

Table 1-1 Effect of feeding method on coupling yield

Feeding method Coupling pH Coupling temperature/°C Ratio/mol Absorbance percent/g

A6～715℃1:10.42080.15

B6～715℃1:10.43883.58

Note: A—represents direct feeding; B—represents stepwise feeding, while controlling the coupling pH between 6 and 7.

It can be seen from Table 1.1 that the yield of step-by-step feeding is higher than that of one-time feeding. Therefore, step-by-step feeding was adopted in the experiment.

Example 2:

The present invention has done a group of experiments on the influence of the acid-binding agent on the reaction of the coupling reaction. The acid-binding agent can neutralize the hydrochloric acid produced by the reaction, so as to promote the forward progress of the reaction. Four acid-binding agents, Na2CO3, NaHCO3, KHCO3 and NaH2PO4, were selected for this experiment. The experimental data records and results are shown in Table 1.2.

The impact of table 1-2 acid-binding agent on the coupling yield

No. Coupling pH Coupling temperature/°C Ratio/mol Acid-binding agent Absorbance percentage/g

16～715℃1:1Na2CO30.36073.53

26～715℃1:1NaHCO30.44179.73

36～715℃1:1KHCO30.30057.19

46～715℃1:1NaH2PO40.29068.03

It can be seen from Table 1.2 that the yield of coupling product with sodium bicarbonate as acid-binding agent is the highest. Therefore, sodium bicarbonate is preferred as the acid-binding agent.

Claims (1)

1. a method for preparing direct red 253, is characterized in that, described method comprises following preparation steps: a) In a 250mL three-necked flask, add 2.6mL concentrated hydrochloric acid and 7.4mL water, and control the temperature at 29~31°C; add 1.47g (0.0053mol) of 4-aminoazobenzene-4'-sulfonic acid to a small beaker Dissolve 10mL of water and stir evenly, adjust the pH of the solution to 7~8 with 10% Na ₂ CO ₃ solution, then add 2.6mL (0.1mol) sodium nitrite solution, stir well, gradually drop the mixed solution into hydrochloric acid and water In a three-necked flask, carry out the diazotization reaction, drop it for 0.5~1h, and then react for 2.5~3h, use starch potassium iodide test paper to detect whether the end point is reached, if there is excessive sodium nitrite in the reaction solution, use 10% sulfamate The acid solution is destroyed, the reaction is over, and the product is ready for use; b) Weigh 1.33g (0.0056mol) of J acid, adjust the pH of the J acid solution between 6 and 7 with 10% Na ₂ CO ₃ solution, and wait until the J acid becomes clear; take 0.92g (0.0051mol) of cyanuric chloride ), add 10~15ml of water, keep the temperature at 0~5°C, and after the pH drops to 1.5~2, slowly add the clear J acid into the cyanuric chloride solution, and the time of dropping J acid is controlled at 4 ~5 hours, the reaction is over, ready for use; c) Adjust the temperature of the reaction product of b to 15~20°C, adjust the pH between 6 and 6.5 with 10% Na ₂ CO ₃ , then add the reaction product of a to the mixture dropwise, and react for 1.5 to 2 hours after the reaction is complete , to reach the end of the reaction after continuing to react for 0.5h; d) Control the temperature of the coupling product c at 10°C, weigh 0.365 g (0.598 mol) of ethanolamine and adjust the pH between 8 and 9 with 10% Na ₂ CO ₃ solution, add it to the coupling product c for condensation reaction, After adding the materials, raise the temperature to 45~50°C, adjust the pH between 5~6 with 10% Na ₂ CO ₃ , and wait until the pH becomes stable as the end point of the experiment, and the time is 3~4 hours; e) Control the temperature of the reaction product of d between 45~50°C; weigh 0.365g (0.598mol) of ethanolamine and adjust the pH to 7~7.5 with 10% Na ₂ CO ₃ , add it to the dicondensate d, After adding, raise the temperature to 90~100℃, and the pH is basically stable as the end point, and the time is 2.5~3 hours; The final dye is purified with sodium chloride, the specific method is as follows: dissolve the dye in deionized water, not too much, filter to remove impurities, keep the filtrate, add sodium chloride to the filtrate to salt out according to W/V=20%, filter, filter cake Dissolving with deionized water and salting out with sodium chloride, repeating this three times, and then drying the filter cake to obtain a dye with higher purity.