Pigment Carbon Black oxidation treatment refers to the process in which carbon black particles are modified by oxidation with an oxidizing agent. Surface oxidation treatment can change the surface volume, porosity and conductivity of carbon black.
The process of modification through Oxidation treatment makes pigment carbon black more suitable for the required products.
How many ways can Pigment carbon black be oxidized?
There are several oxidation treatment methods, but there are two common oxidation treatment methods, namely, gas-phase oxidation method, liquid-phase oxidation method and new plasma method.
The oxidants of gas phase oxidation include molecular oxygen, atomic oxygen, ozone, dry air or moist air, oxygen oxidation, etc.;
The oxidants used in liquid-phase oxidation include nitric acid, potassium permanganate, and ozone aqueous solution, and nitric acid oxidation, concentrated sulfuric acid oxidation, and potassium chloride oxidation are used.
Process for Producing Oxidized Pigment Carbon Black by Gas Phase Oxidation
Gas-phase oxidation method is a relatively traditional oxidation modification method. Put carbon black into the reaction tube, first raise the temperature to 100 degrees Celsius within 1 hour under the same helium condition, and then raise the temperature to the reaction temperature, and react with oxygen for 1 Hours, cut off the oxygen, then helium, and cool to room temperature. The acid and oxygen content on the surface of the carbon black obtained in this way increases, the pH value decreases, the oxygen-containing groups increase, The hydraulicity is enhanced, the specific surface area is increased, and the dispersibility is improved.
Process for producing oxidized Pigment carbon black by liquid phase oxidation
The liquid-phase oxidation method is a modification method in which an oxidant reacts with carbon black to produce carbonyl, hydroxyl, and carboxyl groups on the surface of carbon black.
This method is an oxidation modification method, and the oxidant used is gener all a strong Oxidizing solution such as nitric acid, hydrogen peroxide solution, saturated ammonium persulfate solution, perchloric acid, hypochlorous acid, isocyanate solution and potassium permanganate solution, etc.
The surface of carbon black modified by liquid phase oxidation increases obviously. The reaction time of nitric acid oxidation carbon black is 2 hours, the reaction time of saturated ammonium persulfate solution oxidation carbon black is 24 hours, the reaction time of hydrogen peroxide solution oxidation carbon black is 96 hours rs.
Process for producing oxidized pigment carbon black by plasma method
The plasma method belongs to the physical oxidation method and is an emerging carbon black modification method in recent years. At present, the oxidant of plasma method is mainly oxygen plasma. The main advantages of plasma modification are:
- Oxidation generally only occurs on the surface of carbon black, does not affect the internal structure of carbon black, and can keep the main structure of carbon black unchanged;
- The electron temperature of the plasma is very high, but the gas flow temperature is normal temperature, and the oxygen-containing groups on the surface of carbon black will not decompose;
- The oxidation reaction can be carried out under oxidation, reduction, inertia and other atmospheres;
- Short reaction time;
- Compared with the liquid phase method, the plasma method avoids the discharge of a large amount of waste liquid, and there is no solid and liquid phase separation process, and the modification cost is lower.
