1992 Volume 18 Issue 1 Pages 58-65
A composite electrically conductive resin in which conductive fillers are kneaded within the matrix resin is gaining attention as an EMI shield material. Basic studies of the relation between the dispersion state of the fillers and kneading conditions or electrical conductivity are very important, but the studies to date are not sufficient.In this study, we performed continuous kneading of such conductive resins. Three resins, ABS, PS and PP, were employed as matrix resin. Bacause the electrical conductivity was affected by the state of construction of the electric circuit by the fillers, we took notice of the dispersion of fillers or their mean length.
The dispersion of fillers caused by kneading was evaluated by using a dimensionless number formed from the shear stress and the apparent viscosity of the matrix resin. We can quantitatively determine the dispersion state of fillers by using this dimensionless number. In addition, the relation between the conductivity and the kneading condition is also found by using the same dimensionless number, considering the dispersion state of the fillers and their length.
From this quantitative analysis, the relation between matrix resin, operating condition of continuous kneader and electrical conductivity can be clarified.
