Conductive agent in rubber grommets
Most rubber materials are electrical insulators. If conductive rubber grommets are made of a rubber material, in addition to introducing a conductive functional group into the rubber molecular chain, another convenient method is to add a conductive agent, that is, a conductive filler or a metal filler, to the rubber compound. It distributes in the rubber grommets to form chain and mesh passages to produce electrical conduction. Conductive rubber has recently developed rapidly and has been highly valued by researchers. Commonly used conductive agents are carbon black, graphite powder, metal powder and conductive fibers. The particle size and structure of carbon black have a great influence on the electrical conductivity of rubber and are the main conductive agents.
Conductive furnace black
The main varieties are N293, N294, N472. N293 and N294 have fine particle size, structural enthalpy, large surface activity and good reinforcing performance. N472 has a very high surface area and structure, BET surface area of 270m2 / g, DBP oil absorption value of 1. 78cm / g, the conductivity in the rubber is better than N293, N294, acetylene and carbon black, but the reinforcement Not as good as N293 and N294. The N294 with strong reinforcement and conductivity is currently being phased out. Conductive carbon black is hot when kneaded, and should be burnt.
Acetylene black
It is a medium particle size (30~40nm), the highest structural (DBP oil absorption value of 3. 0~3. 5cm3 / g), carbon black with very low volatile matter and ash, so the conductivity and thermal conductivity are very good. Has a medium level of reinforcement. The volume resistivity of the vulcanized rubber is about 10 to 100 Q • cm. However, the rubber has a high heat generation, and the usual amount is between 40 and 50 parts.