Physical and Chemical Properties | Chemical properties Carbon-based composite conductive materials have low price, long-lasting conductivity, good stability and greater selectivity according to different conductivity requirements. The volume resistivity of their products can vary in a wide range from 10 Ω.cm to 103 Ω.cm. |
Use | Use can eliminate static electricity, prevent static electricity, can also be used as a surface heating body electromagnetic wave shielding and high conductor, electrode material, which is characterized by the appearance of the finished product can only be black. |
Surface treatment of carbon black; in order to improve the dispersibility of carbon black and the affinity with the resin, it is necessary to use an appropriate coupling agent for surface treatment. The coupling agent is generally selected as titanate type, and the treatment method is generally rolled and mixed to make the carbon black surface fully impregnated. During surface treatment, attention should be paid to the type of coupling agent selected, treatment temperature, time, and The speed of the mixer and other process parameters.
The amount of carbon black: when the polymer is filled with conductive material, it has a curve model with basically the same amount and electrical properties. There are critical concentration and saturation concentration on the curve. It is worth noting that it is related to the amount of carbon black and the type of resin.
Compounding of carbon-based conductive fillers and polymers: The final products of carbon-based filler-filled polymers mainly include conductive plastics, conductive rubber and conductive adhesives. Different products have different compounding methods.
Mixing of carbon black and resin. The preparation of carbon black filled conductive mixed pellets is done by a mixer. The equipment used in mixing is generally a double-roll plasticizer, an internal mixer and a high-filling spiral extruder. Due to the different degrees of shear during the mixing process, the structure of the carbon black will be damaged, resulting in The electrical conductivity of the composite material is reduced. Therefore, a certain mixing time must be controlled under the most appropriate temperature conditions to complete the mixing operation, different types of carbon black have different sensitivity to mixing time, such as acetylene carbon black, so conductivity depends on the structure, and is very sensitive to mixing time. With the increase of mixing time, once the structure of carbon black is damaged, the resistance value will increase significantly.
Processing of carbon black filled rubber. Mix the rubber before adding the filler, and adjust it to an appropriate degree of plasticity to meet the needs of subsequent projects. Then, the filler is dispersed in the rubber by equipment such as an internal mixer or a screw extruder, and vulcanization is beneficial to conductivity. For varieties that are resistant to black, the volume resistivity after vulcanization is 1/10-1/100 lower than that before vulcanization.