Correlation between resistor characteristics and cohesive property of carbon black in resin

Carbon black (CB)-reson composites have been studied through resistivity parameters (resistivity), ( rho ), temperature coefficient of resistance (TCR), a parameter of the dielectric relaxation time, and equivalent circuit parameters (R/sup s/, R/sup c/, C/sup c/) using two kinds of CBs. High-structure CB results in smaller rho and TCR than does low-structure CB, suggesting that the former CB easily forms a mechanically stronger aggregation of CB structures, leading to more conductive paths bridging electrodes. There is a difference between the dielectric relaxation types on the Cole-Cole plot. The high-structure CB shows a Cole-Cole type relaxation, whereas the low-structure CB shows a Davidson-Cole one. The parameters giving a measure of the distribution of the relaxation time increase with loading. It is noted that branches of conductive paths become uniform with higher loading. Though the difference of C/sup c/ between the two CBs is not clear, the high-structure CB shows smaller R/sup s/ and R/sup c/ than the low-structure one at a given loading of CB.<
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