Production process of J acid with high purity and high amino value

Abstract

The invention provides a production process of high-purity and high-amino-value J acid, and relates to the technical field of dye intermediate production processes. The production process comprises the following steps: (1) tobias acid sulfonation; (2) carrying out hydrolysis and salting-out on the 2-naphthylamine-1, 5, 7-trisulfonic acid; (3) filtering, washing and dissolving the 2-naphthylamine-5, 7-disulfonic acid monosodium salt; (4) concentration of 2-naphthylamine-5, 7-disulfonic acid disodium salt and mirabilite treatment; (5) carrying out alkali fusion on the 2-naphthylamine-5, 7-disulfonic acid disodium salt; (6) acidification of J acid sodium salt; the step (6) comprises the following specific steps: mixing the alkali fusion material with water, and adding dilute sulphuric acid to finish first acidification; and filtering the material after the first acidification to obtain a filtrate, and adding dilute sulphuric acid to complete the second acidification. The acidification process of the J acid production process is optimized, and the purity and amino value of the J acid are effectively improved through two acidification processes.

Description

Technical Field

[0001] The invention belongs to the technical field of dye intermediate production technology, and relates to a production process of high-purity and high-amino value J acid. Background Art

[0002] J acid, scientifically known as 2-amino-5-naphthol-7-sulfonic acid or 6-amino-1-naphthol-3-sulfonic acid, is a white or light grey crystal or crystalline powder. It is slightly soluble in cold water, soluble in hot water, and almost insoluble in ethanol, but soluble in alkaline solutions such as soda ash and caustic soda. J acid is an important dye intermediate used to make azo dyes, and can be used to prepare di-J acid, scarlet acid and amino J acid, etc. It is widely used in the manufacture of direct dyes, acid dyes and reactive dyes.

[0003] At present, the main synthetic process of traditional J acid in China is: sulfonate Tobias acid in fuming sulfuric acid with high sulfur trioxide concentration, hydrolyze in dilute sulfuric acid to produce amino J acid, then salt out to obtain amino J acid monosodium salt, then neutralize and dissolve with sodium hydroxide to obtain amino J acid disodium salt, then slowly add to concentrated alkali solution for alkali melting, and finally acidify in dilute sulfuric acid solution to prepare J acid. The preparation of J acid by this process has many impurities, low yield, and will produce a large amount of strong acid wastewater, which is difficult to treat.

[0004] Chinese patent CN105418463A discloses an improved J acid synthesis process: Tobias acid is sulfonated and hydrolyzed to obtain 2-naphthoic acid-5,7-disulfonic monosodium salt (amino J acid), and then neutralized, alkali-fused, and acidified to obtain J acid products and J acid wastewater, characterized in that it includes the following steps: (1) pretreatment: the J acid wastewater is pretreated to remove some organic matter in the wastewater; (2) electrodialysis concentration: the pretreated filtrate is concentrated by electrodialysis to obtain concentrated water, that is, the concentrated salt solution; (3) bipolar membrane desalination: the salt solution obtained in step (2) is treated by bipolar membrane electrodialysis to obtain sulfuric acid solution, sodium hydroxide solution and dilute brine, and the acid and alkali can be recycled to the J acid synthesis process, and the dilute brine is circulated to the electrodialysis device for concentration. This patent only recycles the wastewater in the J acid synthesis process, and does not improve the synthesis steps of J acid. Therefore, the purity and amino value of J acid are not changed.

[0005] Chinese patent CN104045584B discloses a clean production process of 2-(N-substituted amino)-5-naphthol-7-sulfonic acid: (1) condensation reaction: add bottom water to the reactor, then add 2-amino-5-naphthol-7-sulfonic acid, methylamine or aniline, and reducing product in sequence, then use inorganic acid or inorganic base to control the reaction pH to 4-8, then heat to 80-120°C, reflux reaction for 10-30 hours to the reaction end point, and use liquid phase detection to detect the residual amount of 2-amino-5-naphthol-7-sulfonic acid ≤10% as the qualified end point; (2) material post-treatment: after reaching the reaction end point, cool to 10-50°C Then, the material is acidified to pH=0-6 with an inorganic acid, filtered by pressure or suction, the filter cake is collected, and the filtrate 1 is collected. The collected filtrate 1 is used as the bottom water for the next batch of condensation reactions; (3) Filter cake refining: add bottom water to the reactor, then add the filter cake collected in step B, then acidify the material to pH=0-6 with an inorganic acid, stir for 1-3 hours, then filter by pressure or suction, and then spin dry with a centrifuge to collect the filter cake, collect the filtrate 2, the collected filter cake is the target product 2-(N-substituted amino)-5-naphthol-7-sulfonic acid, the amino value is ≥65%, the HPLC purity is ≥95%, and the collected filtrate 2 is used for the refined bottom water of the next batch of filter cakes. This patent improves the entire production process and effectively improves the purity of J acid, but the improvement of the amino value of J acid is limited.

[0006] In view of this, a production process of high-purity, high-amino value J acid is urgently needed. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies in previous studies and to provide a production process for high-purity, high-amino value J acid.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0009] In one aspect, the present invention provides a production process for high-purity, high-amino value J acid, comprising the following steps:

[0010] Step (1): Sulfonation of Tobias acid

[0011]

[0012] Step (2): Hydrolysis and salting out of 2-naphthylamine-1,5,7-trisulfonic acid

[0013]

[0014] Step (3): Filtration, washing and dissolution of 2-naphthylamine-5,7-disulfonic acid monosodium salt (amino J acid filtration)

[0015]

[0016] Step (4): concentration of 2-naphthylamine-5,7-disulfonic acid disodium salt and treatment with sodium sulfate;

[0017] Step (5): Alkali fusion of 2-naphthylamine-5,7-disulfonic acid disodium salt (alkali fusion)

[0018]

[0019] Step (6): Acidification of J acid sodium salt

[0020]

[0021] The specific steps of step (6) are as follows:

[0022] After the alkali-melted material is mixed with water, dilute sulfuric acid is added to complete the first acidification; after the material after the first acidification is filtered, dilute sulfuric acid is added to obtain the filtrate to complete the second acidification.

[0023] Preferably, the specific steps of step (6) are as follows:

[0024] After mixing the alkali-melted material with water, add dilute sulfuric acid, and stop adding acid when the pH of the mixed system is 7.0-7.5 to complete the first acidification; filter the material after the first acidification, and add dilute sulfuric acid to obtain the filtrate, and control the acidity of the mixed system to 45-60g / L to complete the second acidification.

[0025] Further preferably, the specific steps of step (6) are as follows:

[0026] After mixing the alkali-melted material with water, dilute sulfuric acid is added. When the pH of the mixed system is 7.0, the acid addition is stopped to complete the first acidification. The material after the first acidification is filtered, and after obtaining the filtrate, dilute sulfuric acid is added to control the acidity of the mixed system to 45g / L to complete the second acidification.

[0027] Preferably, in step (6), the mass ratio of the alkali-melting material to water is 1:1.5-2.

[0028] Further preferably, in step (6), the mass ratio of the alkali-melting material to water is 1:1.5.

[0029] Preferably, in step (6), the concentration of the dilute sulfuric acid in the first acidification is 280-360 g / L.

[0030] Further preferably, in step (6), the concentration of the dilute sulfuric acid in the first acidification is 280 g / L.

[0031] Preferably, in step (6), the concentration of the dilute sulfuric acid in the second acidification is 280-360 g / L.

[0032] Further preferably, in step (6), the concentration of the dilute sulfuric acid in the second acidification is 280 g / L.

[0033] In another aspect, the present invention provides J acid prepared according to the above production process.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The invention discloses a production process of high-purity and high-amino value J acid, optimizes the acidification process of the J acid production process, and effectively improves the purity and amino value of the J acid through two acidification processes. DETAILED DESCRIPTION

[0036] The following non-limiting examples can enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. The following content is merely an exemplary description of the scope of the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, which should also fall within the scope of the present invention.

[0037] The present invention is further described below by way of specific examples. Unless otherwise specified, the various drugs used in the examples of the present invention are obtained through conventional commercial channels.

[0038] Example 1

[0039] Synthesis route of J acid:

[0040] (1) Tobias acid sulfonation:

[0041]

[0042] (2) Hydrolysis and salting out of 2-naphthylamine-1,5,7-trisulfonic acid:

[0043]

[0044] (3) Filtration, washing and dissolution of 2-naphthylamine-5,7-disulfonic acid monosodium salt (amino J acid filtration):

[0045] (4) Concentration and mirabilite treatment of disodium 2-naphthylamine-5,7-disulfonic acid;

[0046] (5) Alkali fusion of 2-naphthylamine-5,7-disulfonic acid disodium salt (alkali fusion):

[0047]

[0048] (6) Acidification (acidification) of sodium salt of J acid:

[0049]

[0050] (7) Filter pressing and drying.

[0051] Example 2

[0052] Steps (1) to (5) are the same as those in Example 1;

[0053] (6) Acidification (acidification) process of sodium salt of J acid:

[0054]

[0055] The specific steps of the acid precipitation process are as follows:

[0056] Mixing alkali-melted materials (alkali-melted materials composition: amino J acid 2.5-3%, hydroxy J acid 5-7%, γ acid 1-1.5%, J acid 88-89%, unknown substance 0.3-0.4%, di-J acid 0.1-0.2%) with water in an acidification pot, the mass ratio of alkali-melted materials to water is 1:1.5, adding 280g / L of dilute sulfuric acid into the acidification pot, and stopping the acidification when the pH of the material reaches 7.0, completing the first acidification; filtering the material after the first acidification, adding the obtained filtrate into a secondary acidification pot, adding 280 / L of dilute sulfuric acid into the secondary acidification pot, controlling the acidity end point to 45g / L, completing the second acidification;

[0057] (7) The specific steps of the filter pressing and drying process are as follows:

[0058] The material is cooled to 30°C and maintained for 1 hour before being pumped into a filter press for filtration. The acidified mother liquor from the filtration flows by gravity into the acidified mother liquor tank. The filter cake is placed in the lower pulping tank and dissolved and pulped with water for washing. The pulped material is then pumped into a filter press for filtration and dried with compressed air. The filtrate flows by gravity into the finished product washing water mother liquor tank, and the filter cake is sent to a flash dryer for drying.

[0059] Example 3

[0060] Step (1), step (2), step (3), step (4), step (5), and step (7) are the same as those in Example 2;

[0061] (6) Acidification (acidification) process of sodium salt of J acid:

[0062]

[0063] The specific steps of the acid precipitation process are as follows:

[0064] Alkali molten materials (alkaline molten materials composition: amino J acid 2.5-3%, hydroxy J acid 5-7%, gamma acid 1-1.5%, J acid 88-89%, unknown substance 0.3-0.4%, di-J acid 0.1-0.2%) and water are mixed in an acidification pot, the mass ratio of the alkali molten materials to water is 1:2, 360 g / L of dilute sulfuric acid is added into the acidification pot, and when the pH value of the materials reaches 7.5, the acid addition is stopped to complete the first acidification; the materials after the first acidification are filtered, and the obtained filtrate is added into a secondary acidification pot, and 360 g / L of dilute sulfuric acid is added into the secondary acidification pot, and the acidity end point is controlled to be 60 g / L to complete the second acidification.

[0065] Comparative Example 1

[0066] Step (1), step (2), step (3), step (4), step (5), and step (7) are the same as those in Example 2;

[0067] Except for the acidification step, the remaining steps are the same as those in Example 2.

[0068] (6) Acidification (acidification) process of sodium salt of J acid:

[0069]

[0070] The specific steps of the acid precipitation process are as follows:

[0071] 1. Prepare acidified base acid: add 2000L of semi-finished mother liquor (composition of semi-finished mother liquor: 650g / L sulfuric acid, 60-70g / L sodium sulfate, solvent is water) and 2000L of washing water (60g / L sulfuric acid, 10g / L finished J acid material, solvent is water) into the acidification pot;

[0072] 2. Neutralization acidification process: slowly add alkali-melt materials into the acidification pot (composition of alkali-melt materials: amino J acid 2.5-3%, hydroxy J acid 5-7%, gamma acid 1-1.5%, J acid 88-89%, unknown substance 0.3-0.4%, di-J acid 0.1-0.2%), observe the reaction of materials in the acidification pot through the manhole sight glass, and take the emptying pipeline sight glass as the standard without material leakage, add all the materials in 1.5-2 hours to complete the acidification process.

[0073] Comparative Example 2

[0074] Step (1), step (2), step (3), step (4), step (5), and step (7) are the same as those in Example 2;

[0075] (6) Acidification (acidification) process of sodium salt of J acid:

[0076]

[0077] The specific steps of the acid precipitation process are as follows:

[0078] Alkali molten materials (alkaline molten materials composition: amino J acid 2.5-3%, hydroxy J acid 5-7%, gamma acid 1-1.5%, J acid 88-89%, unknown substance 0.3-0.4%, di-J acid 0.1-0.2%) and water are mixed in an acidification pot, the mass ratio of the alkali molten materials to water is 1:1, 260 g / L of dilute sulfuric acid is added into the acidification pot, and when the pH value of the material reaches 8.5, the acid addition is stopped to complete the first acidification; the material after the first acidification is filtered, and the obtained filtrate is added into a secondary acidification pot, and 260 g / L of dilute sulfuric acid is added into the secondary acidification pot, and the acidity end point is controlled to be 40 g / L to complete the second acidification.

[0079] Comparative Example 3

[0080] Step (1), step (2), step (3), step (4), step (5), and step (7) are the same as those in Example 2;

[0081] (6) Acidification (acidification) process of sodium salt of J acid:

[0082]

[0083] The specific steps of the acid precipitation process are as follows:

[0084] Alkali molten materials (alkaline molten materials composition: amino J acid 2.5-3%, hydroxy J acid 5-7%, gamma acid 1-1.5%, J acid 88-89%, unknown substance 0.3-0.4%, di-J acid 0.1-0.2%) and water are mixed in an acidification pot, the mass ratio of the alkali molten materials to water is 1:1, 260 g / L of dilute sulfuric acid is added into the acidification pot, and when the pH value of the materials reaches 5.5, the acid addition is stopped to complete the first acidification; the materials after the first acidification are filtered, and the obtained filtrate is added into a second acidification pot, and 260 g / L of dilute sulfuric acid is added into the second acidification pot, and the acidity end point is controlled to be 40 g / L to complete the second acidification.

[0085] Comparative Example 4

[0086] Step (1), step (2), step (3), step (4), step (5), and step (7) are the same as those in Example 2;

[0087] (6) Acidification (acidification) process of sodium salt of J acid:

[0088]

[0089] The specific steps of the acid precipitation process are as follows:

[0090] Alkali molten materials (alkaline molten materials composition: amino J acid 2.5-3%, hydroxy J acid 5-7%, gamma acid 1-1.5%, J acid 88-89%, unknown substance 0.3-0.4%, di-J acid 0.1-0.2%) and water are mixed in an acidification pot, the mass ratio of the alkali molten materials to water is 1:1, 260 g / L of dilute sulfuric acid is added into the acidification pot, and when the pH value of the materials reaches 6.5, the acid addition is stopped to complete the first acidification; the materials after the first acidification are filtered, and the obtained filtrate is added into a secondary acidification pot, and 260 g / L of dilute sulfuric acid is added into the secondary acidification pot, and the acidity end point is controlled to be 30 g / L to complete the second acidification.

[0091] Comparative Example 5

[0092] Step (1), step (2), step (3), step (4), step (5), and step (7) are the same as those in Example 2;

[0093] (6) Acidification (acidification) process of sodium salt of J acid:

[0094]

[0095] The specific steps of the acid precipitation process are as follows:

[0096] Alkali molten materials (alkaline molten materials composition: amino J acid 2.5-3%, hydroxy J acid 5-7%, gamma acid 1-1.5%, J acid 88-89%, unknown substance 0.3-0.4%, di-J acid 0.1-0.2%) and water are mixed in an acidification pot, the mass ratio of the alkali molten materials to water is 1:1, 260 g / L of dilute sulfuric acid is added into the acidification pot, and when the pH value of the material reaches 6.5, the acid addition is stopped to complete the first acidification; the material after the first acidification is filtered, and the obtained filtrate is added into a secondary acidification pot, and 260 g / L of dilute sulfuric acid is added into the secondary acidification pot, and the acidity end point is controlled to be 70 g / L to complete the second acidification.

[0097] Results

[0098] 1. Preparation of reserve solution

[0099] Pipette 5 mL of the homogeneous sample acidified mother solution and dilute it with acid-free water into a 200 mL volumetric flask, shake well and set aside.

[0100] 2. Acidity measurement method

[0101] Use a pipette to accurately pipette 20 mL of the reserve solution into a 500 mL beaker containing 400 mL of acid-free water, add 2 drops of phenolphthalein indicator, and titrate with 1 mol / L sodium hydroxide standard solution until the solution turns light red, which is the end point.

[0102] Calculation formula:

[0103]

[0104] 3. Measurement method of amino value

[0105] In the beaker for titrating the acidity, add 10 mL of 10% potassium bromide and 10 mL of analytical pure hydrochloric acid, and titrate with 0.1 mol / L sodium nitrite standard solution. The end point is when the sample shows a light blue color to the starch potassium iodide solution and remains unchanged for 3 minutes.

[0106] Calculation formula:

[0107]

[0108] The results are as follows:

[0109] Table 1

[0110]

[0111] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A production process for high-purity, high-amino value J acid, characterized in that: The steps are as follows: Step (1): Sulfonation of Tobias acid Step (2): Hydrolysis and salting out of 2-naphthylamine-1,5,7-trisulfonic acid Step (3): Filtration, washing and dissolution of 2-naphthylamine-5,7-disulfonic acid monosodium salt Step (4): concentration of 2-naphthylamine-5,7-disulfonic acid disodium salt and treatment with sodium sulfate; Step (5): Alkali fusion of 2-naphthylamine-5,7-disulfonic acid disodium salt Step (6): Acid precipitation of sodium salt of J acid The specific steps of step (6) are as follows: After the alkali-melted material is mixed with water, dilute sulfuric acid is added to complete the first acidification; after the material after the first acidification is filtered, dilute sulfuric acid is added to obtain the filtrate to complete the second acidification.

2. The production process according to claim 1, characterized in that: The specific steps of step (6) are as follows: After mixing the alkali-melted material with water, add dilute sulfuric acid, and stop adding acid when the pH of the mixed system is 7.0-7.5 to complete the first acidification; filter the material after the first acidification, and add dilute sulfuric acid to obtain the filtrate, and control the acidity of the mixed system to 45-60g / L to complete the second acidification.

3. The production process according to claim 2, characterized in that: The specific steps of step (6) are as follows: After mixing the alkali-melted material with water, dilute sulfuric acid is added. When the pH of the mixed system is 7.0, the acid addition is stopped to complete the first acidification. The material after the first acidification is filtered, and after obtaining the filtrate, dilute sulfuric acid is added to control the acidity of the mixed system to 45g / L to complete the second acidification.

4. The production process according to claim 1, characterized in that: In step (6), the mass ratio of the alkali-melting material to water is 1:1.5-2.

5. The production process according to claim 4, characterized in that: In step (6), the mass ratio of the alkali-melting material to water is 1:1.

5.

6. The production process according to claim 1, characterized in that: In step (6), the concentration of the dilute sulfuric acid in the first acidification is 280-360 g / L.

7. The production process according to claim 6, characterized in that: In step (6), the concentration of the dilute sulfuric acid in the first acidification is 280 g / L.

8. The production process according to claim 1, characterized in that: In step (6), the concentration of the dilute sulfuric acid in the second acidification is 280-360 g / L.

9. The production process according to claim 8, characterized in that: In step (6), the concentration of the dilute sulfuric acid in the second acidification is 280 g / L.

10. J acid prepared according to the production process according to any one of claims 1 to 9.

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