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CN-121976207-A - Constant potential electrolytic preparation method of C.I. acid blue 9

CN121976207ACN 121976207 ACN121976207 ACN 121976207ACN-121976207-A

Abstract

A constant potential electrolysis preparation method of C.I. acid blue 9 belongs to the fields of dye preparation and electrochemistry. The method comprises the following steps of preparing an electrolyte from the C.I. acid blue 9 leuco body, adopting a split type electrolytic cell, and directly and electrochemically oxidizing the C.I. acid blue 9 leuco body to a color development body by using a three-electrode system constant potential. The constant potential electrolytic preparation method of the C.I. acid blue 9 can lead the acid blue 9 leuco to be completely converted and have higher yield, avoid the introduction of heavy metal oxide, and fundamentally solve the problem of heavy metal pollution and difficult metal recycling in the C.I. acid blue 9 synthesis process. The method has the advantages of simple process, high current utilization efficiency, environment-friendly production process and the like.

Inventors

  • LV RONGWEN
  • Hao Shoulong
  • ZHANG SHUFEN

Assignees

  • 大连理工大学

Dates

Publication Date
20260505
Application Date
20260206

Claims (9)

  1. 1. A constant potential electrolysis preparation method of C.I. acid blue 9 is characterized in that the reaction is as follows: ; The method comprises the following steps: (1) Mixing the C.I. acid blue 9 leuco and anode supporting electrolyte with a solvent to prepare an anolyte; the concentration of the C.I. acid blue 9 leuco is 0.001 mol/L-0.02 mol/L, and the concentration of the supporting electrolyte is 0.1-0.5M; (2) Mixing a cathode supporting electrolyte, inorganic acid and a solvent to prepare a cathode electrolyte; The concentration of the supporting electrolyte is 0.1-0.5M, and the mass concentration of the inorganic acid is 0.5-5%; (3) Transferring the electrolyte to a corresponding electrolytic cell, separating a cathode and an anode by using a proton exchange membrane, inserting an electrode, starting a power supply for electrolysis until the C.I. acid blue 9 leuco is completely converted, and completing the reaction; the electrolysis conditions are that the electrolysis voltage is 0.4-1.2V, the pH is 2-6, the electrolysis time is 0.1-7 h, and the temperature of the electrolysis tank is 25-40 ℃; the anode is a carbon electrode prepared from carbon materials with different forms, the carbon materials are glass carbon and graphite, and the carbon materials are paper, bars, plates and felts.
  2. 2. The method for preparing C.I. acid blue 9 by constant potential electrolysis according to claim 1, wherein the solvent is one or more of water, ethanol, methanol, acetone and dimethyl sulfoxide.
  3. 3. The method for preparing C.I. acid blue 9 by constant potential electrolysis according to claim 1, wherein the anode supporting electrolyte is one or more of NaCl、KCl、Na 2 SO 4 、Na 2 SO 3 、CH 3 COONa、KNO 3 、CH 3 COONa、CH 3 COOK、CH 3 COONH 4 、Mg(CH 3 COO) 2 、Na 2 HPO 4 、NaH 2 PO 4 .
  4. 4. The method for preparing C.I. acid blue 9 by constant potential electrolysis according to claim 1, wherein the cathode supporting electrolyte is one or more of NaCl、KCl、Na 2 SO 4 、Na 2 SO 3 、CH 3 COONa、KNO 3 、CH 3 COONa、CH 3 COOK、CH 3 COONH 4 、Mg(CH 3 COO) 2 、Na 2 HPO 4 、NaH 2 PO 4 .
  5. 5. The method for preparing C.I. acid blue 9 by constant potential electrolysis according to claim 1, wherein the inorganic acid is one or more of HCl and H 2 SO 4 、H 3 PO 4 .
  6. 6. The method for preparing C.I. acid blue 9 by constant potential electrolysis according to claim 1, wherein the proton exchange membrane is one of a perfluorinated sulfonic acid membrane, a partially fluorinated sulfonic acid membrane, a non-fluorinated sulfonic acid membrane, a polybenzimidazole membrane and an alkaline ionic membrane.
  7. 7. The method for preparing the constant potential electrolyte of the C.I. acid blue 9, which is characterized in that the method for preparing the anode is as follows: (a) Selecting a carbon material, and alternately ultrasonically cleaning in a washing liquid A and a washing liquid B to remove impurities on the surface of the electrode for standby; (b) The electrodes are activated alternately in acid liquor and alkali liquor by using cyclic voltammetry; (c) Fully soaking the electrode in electrolyte; the washing liquid A in the step (a) is low-carbon alcohol selected from ethanol or isopropanol, the washing liquid B is deionized water, and the ultrasonic time in each washing liquid is 0.1-2 h; The acid liquor in the step (b) is 0.1-1M sulfuric acid solution, the alkali liquor is 0.1-2M NaOH or KOH solution, the cyclic voltammetry scanning range is-3V, the scanning speed is 0.001-0.5V/s, and the scanning circle number is 10-100; the soaking time in the step (c) is 0.5-2 h.
  8. 8. The method for preparing C.I. acid blue 9 by constant potential electrolysis according to claim 1, wherein the cathode is one of a titanium electrode, a platinum electrode, a copper electrode, an iron electrode, a nickel electrode, a gold electrode, a graphite electrode, an indium electrode, a tungsten electrode, a tantalum electrode, a lead electrode, a molybdenum electrode or a silver electrode.
  9. 9. The method for preparing the C.I. acid blue 9 by constant potential electrolysis according to claim 1 is characterized in that the power source is a direct current power source, and the electrolysis voltage is 0.3-1.2V.

Description

Constant potential electrolytic preparation method of C.I. acid blue 9 Technical Field The invention relates to the fields of dye technology and electrochemistry, in particular to a constant potential electrolysis preparation method of C.I. acid blue 9. Background The acid dyes of triarylmethane type dyes can be divided into three types of diamino type, triamino type and hydroxyl type according to the structure, aromatic aldehyde and active aromatic hydrocarbon are commonly used for condensation in industry to obtain leuco bodies, and then the leuco bodies are oxidized to obtain color bodies, and the dyes have the characteristics of bright color, environmental friendliness, wide application range and the like. The C.I. acid blue 9 obtained by condensing and oxidizing 2-formylbenzenesulfonic acid and N-ethyl-N- (3-sulfobenzyl) aniline is one of important varieties of acid dyes, has the characteristics of strong tinting strength, bright color, safety and no toxicity, and can be used for foods, cleaning water, wool, chinlon, leather, paper, pressure-sensitive heat-sensitive materials, photosensitive paper, ultrasonic recording paper, heat-sensitive recording paper, printing ink, crayon, photoimaging systems and the like. At present, the oxidation reaction of the industrial C.I. acid blue 9 leuco is realized by using water as a reaction medium and manganese dioxide or potassium dichromate as an oxidant for selective oxidation, and the process is as follows: In the above process, since MnO 2 or K 2Cr2O7 is used as an oxidizing agent, a large amount of heavy metals remain in solution after oxidation despite the short reaction time and the mature process. Because C.I. acid blue 9 is often used for food pigment, the requirement on the concentration of heavy metal in the product is very strict, and the heavy metal is usually removed in the form of adding a precipitator to precipitate heavy metal ions in industry, but the method generates a large amount of heavy metal waste, is difficult to recycle, and faces the problems of heavy metal pollution, difficult recycling of heavy metal and the like. The patent CN102040853B, CN105348846A reports a chemical oxidation method of C.I. acid blue 9 leuco, wherein the patent CN102040853B oxidizes the C.I. acid blue 9 leuco by manganese dioxide in a phosphoric acid solution medium, calcium hydroxide is added in post-treatment to form manganese phosphate and calcium phosphate precipitate, and the low-salt-content dye is obtained by filtering. The disadvantage of this method is that relatively more waste is produced. The patent CN105348846a improves the method on the basis, and the method uses hydrogen peroxide to oxidize heavy metal ions to recycle the heavy metal ions generated in the oxidation process, and the reaction process is relatively complex and the heavy metal ions still exist although the method is relatively green and clean. In recent years, electrochemical synthesis has received attention because of its advantages such as environmental friendliness, mild reaction conditions, easy control of reaction, and the like. The electrochemical technology can accurately regulate and control the electrode potential and current, so that the electrochemical technology has great advantages compared with chemical oxidants or reductants with fixed oxidation-reduction potential. Disclosure of Invention The invention aims to solve the problems of heavy metal oxidant, difficult recycling of heavy metal and the like, and provides a constant potential electrolysis preparation method of a C.I. acid blue 9 leuco body, which avoids the addition of the heavy metal oxidant, simultaneously avoids the use of other oxidants (such as hydrogen peroxide), completely converts the C.I. acid blue 9 leuco body, fundamentally solves the problems of heavy metal pollution, difficult recycling of heavy metal and the like, and compared with a constant current method, the constant potential method has more accurate control of electrode potential, and can effectively avoid the problem of product peroxidation caused by system electrolysis voltage improvement of the constant current method. In addition, a carbon electrode with lower cost is used as an anode, and a product with higher selectivity is obtained on the premise of complete conversion. In order to achieve the above purpose, the technical scheme of the invention is as follows, a constant potential electrolysis method of C.I. acid blue 9 leuco, the reaction is as follows: The method comprises the following steps: (1) Mixing the C.I. acid blue 9 leuco and anode supporting electrolyte with the solution to prepare an anolyte; The concentration of the C.I. acid blue 9 leuco is 0.001 mol/L-0.02 mol/L, and the concentration of the supporting electrolyte is 0.1-0.5 mol/L; (2) Mixing a cathode supporting electrolyte, inorganic acid and a solution to prepare a cathode electrolyte; the concentration of the supporting electrolyte is 0.1-0.5M, and the mass concentrat