Permeability of seven kinds of JIS Test Powder beds was measured with N₂ gas converted to the specific surface area of powder using various Rigden-type permeability equations including Kozeny-Carman equation.
Kozeny-Carman equation without molecular flow permeation was applicable only to powders coarser than about 10μm.
The experimental results with finer powders suggested that other permeation equations with proper evaluation of molecular flow mechanism should be used and that incorrect evaluation of molecular flow would cause certain non-linear error in the calculated surface area.
Experimental trials to seek an optimal value of the weight coefficient of molecular flow term in Rigden-type equation suggested that the value might be smaller than the Rigden's value, 0.515, which had been the smallest among the proposed value. Further careful study should be done because this result seemed to be too small and might be erroneous due to some experimental errors such as agglomeration and segregation during preparation of powder mixture.

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Relationship between composition of non-magnetic toners and charging properties and the electrophotographic developing characteristics were investigated by using a commercial laser printer. Several kinds of non-magnetic toners with various fractions of charge control agent (CCA) and carbon black were prepared by the conventional pulverzing method. The charging and developing characteristics were found to vary by the fractions of CCA and carbon black in the toners. It was shown that the charging and developing characteristics of the toners are altered by the addition of hydrophobic silica (SiO₂) with different sizes.

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Small binary composite granules of SiC- and CaCO₃-powders were prepared via simultaneous operation of granulation, grinding and separation in a continuous rotating conical vessel.
The structure (morphology) of composite granules obtained under various granulating conditions was studied by measuring distributions of SiC- and CaCO₃- powder in the cross section of a granule with an electron probe microanalyzer (EPMA). The morphology measured by EPMA was compared with the structure models of composite granules estimated from the particle size distributions of SiC- powder agglomerates in a granule by an image analyzer.
As a result, it was shown that the morphology of composite granules measured by EPMA qualitatively agreed with the structure models estimated in our previous paper, and that it was more effective to statistically evaluate the morphology of many composite granules from the particle size distributions of agglomerates contained in the granules using the image analyzer. Furthermore, the effects of granulating conditions on the morphology of composite granules were discussed.

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Mechanically activated molybdenum sulfide (MoS₂) particles were prepared in different grinding atmospheres, i. e. in n-decane, n-decane containing oleic acid as a surfactant and air. A media agitating mill was used as a mechanical activator. The MoS₂ particles were characterized with particle size distribution, specific surface area, particle morphology by TEM, crystal lattice distortion by XRD, element analysis by ICP and hydrogenation activity.
The grinding atmosphere had a significant influence on the characteristics of the prepared MoS₂. The mechanically activated MoS₂ generally had a hydrogenation activity much higher than that as-received, and resulted in a high conversion of 1-methylnaphthalene (1-MN) even at a temperature of 573K, which was a rather low temperature for the hydrogenation reaction of 1-MN with MoS₂. Molybdenum sulfide comminuted for 10h in n-decane had a specific surface area higher than 100m²/g. The specific surface area of MoS₂ comminuted in n-decane containing oleic acid was smaller than that in n-decane, but the particle size distribution, the XRD profile and the catalytic activity were about the same as those in the wet comminution. In the case of dry comminution in air, the prepared MoS₂ particles had characteristics quite different from those in the wet comminution; coarser particle size distribution, very small specific surface area, much broader XRD profile and lower S/Mo ratio. Contrary to our prediction, the MoS₂ particles comminuted in air gave the highest hydrogenation of 1-MN after HCl treatment of the as-comminuted, although the specific surface area was the smallest. This was probably due to highly bent multi-layered structures introduced into molybdenum sulfide particles by dry comminution alone.

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The purpose of this study is to obtain relationships between the physical properties of granules formed by agitating granulation and their tablet in empirical formulas.
First, the size distribution, apparent density, hardness and shapes of granules prepared under various granulation conditions were measured, and then the hardness and surface shapes of their tablet was examined.
As a result, accounting the physical properties of granules in the condition for tabletting high hardness, empirical formulas for hardness of granules and mean particle diameter were proposed. The formulas accurately expressed the experimental results. The relationships among tablet hardness, pressure, friability, and surface roughness were also discussed.

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