CARBON BLACK AND PTC COMPOSITION COMPOUNDED THEREWITH

摘要

PROBLEM TO BE SOLVED: To obtain carbon black capable of imparting positive temperature coefficient of resistance (PTC) suitable as an overcurrent protective element for electric circuits or a self-temperature control-type heating element or the like, and to obtain a PTC composition by compounding a polymer component with the above carbon black. SOLUTION: This carbon black has the mode diameter of aggregate stokes equivalent diameter distribution (Dst) of >=150 nm, toluene color transmittance (LT) of >=60% and compression electrical resistivity (under a pressure of 50 kg/cm2) of <=0.4Ω.cm. The other objective PTC composition is obtained by compounding 100 pts.wt. of a polymer component with 5-200 pts.wt. of the above carbon black.