Carbon black oxidation treatment refers to the process in which carbon black particles are modified by oxidation with an oxidizing agent. Carbon black surface oxidation treatment can change the surface volume, porosity and conductivity of carbon black. It can be said that carbon black oxidation treatment is a modification process through oxidation treatment, which makes carbon black more suitable for the required products. Here, the editor of Carbon Black Industry Network will introduce the carbon black oxidation treatment method and carbon black oxidation modification process.
How many ways can carbon black be oxidized?
However, 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. Oxidants for gas-phase oxidation include molecular oxygen, atomic oxygen, ozone, dry air or humid air, oxygen oxidation, etc.; oxidants for liquid-phase oxidation include nitric acid, potassium permanganate, ozone aqueous solution, nitric acid oxidation, concentrated sulfuric acid oxidation, potassium chlorate oxidation etc.
Production method of oxidized carbon black
Process for Producing Oxidized Carbon Black by Gas Phase Oxidation
Gas-phase oxidation method is a relatively traditional carbon black 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 pass oxygen After reacting for 1 hour, cut off the oxygen, flow helium again, 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 hydrophilicity is enhanced, the specific surface area is increased, and the dispersibility is improved.
Process for producing oxidized carbon black by liquid phase oxidation
The liquid-phase oxidation method, also known as the Huaxia 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 a modified method used in the carbon black industry. The oxidant used is generally 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. The content of oxygen-containing groups on 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.
Process for producing oxidized 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 modified carbon black are:
1. 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;
2. 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;
3. The oxidation reaction can be carried out under oxidation, reduction, inert and other atmospheres;
4. Short reaction time;
5. 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.
What are the benefits of carbon black oxidation?
After post-oxidation treatment, the pH value of carbon black is between 3 and 5, which improves the viscosity, stability and fluidity of carbon black. Pigment carbon black can change the number of surface functional groups through surface treatment, so that its pH value is acidic , the volatile content is also higher, and the oxygen-containing functional groups of the particles increase. That is to say, the oxidized carbon black has the advantages of enhanced hydrophilicity, increased specific surface area, and improved dispersibility.
The above is the oxidized carbon black introduced by Carbon Black Industry Network. In fact, oxidized carbon black can be summarized as oxidized modified carbon black to increase the oxygen-containing groups on its surface. Efficient way to disperse in matrices.