English Abstract
Effects of Large Rotor Shaft on Carbon Black Incorporation and Dispersion in Rubber Mixing
Makoto IRIE
Moriyama Company Ltd., Sanda, Japan
Graduate School of Science and Technology, Nagasaki University, Nagasaki, Japan
Hiroyuki FUKUDA
Moriyama Company Ltd., Sanda, Japan
Michiharu TOH
Department of Biochemistry and Applied Chemistry, Kurume National College of Technology, Kurume, Japan
Mutsuhisa FURUKAWA
Graduate School of Science and Technology, Nagasaki University, Nagasaki, Japan
Nippon Gomu Kyokaishi,(2006),79(11),516-520 Original Paper in Japanese

Styrene-butadiene rubber (SBR) was mixed with carbon black (CB), zinc oxide, etc. using 10 L and 75 L conventional kneaders equipped with conventional rotor, and 7 L and 55 L novel kneaders with new type rotor. The new type rotor used in this study has a large rotating shaft in comparison with the conventional type rotor. These rotors were installed in the same vessels, respectively. Under various rotating speeds and shear rates in the tip, Mooney viscosities and volume resistivities of SBR compounds were measured at arbitrary rotor revolutions. By using the new type rotor, it is thought that mixing will proceed not only in the tip region called the high shear region, but also in the annulus called the low shear region. Mooney viscosities of compounds obtained by 55 L kneader were lower than that by 75 L kneader. Volume resistivities of compounds obtained by novel kneaders were higher than those by conventional kneaders. At the initial stage of mixing in the novel kneader, it is supposed that most of CB was incorporated into SBR in the annulus to form the loose agglomerates of CB in rubber. This may be due to the low shear rate. Then the agglomerates will be collapsed to the fine aggregates of CB in rubber through subsequent mixing.

(Received on April 10, 2006)

(Accepted on August 28, 2006)

SBR Compounds, Carbon Black, Filler Agglomerate, Mooney Viscosity, Volume Resistivity, Annulus, Low Shear Region, Large Rotating Shaft