The aim of this study was to synthesize fine iron particles by reducing an iron complex in an organic solvent. When tris (acetylacetonato) iron (III) in diphenyl ether was refluxed without any reducing agent, or was reduced by hydrazine, no metal iron was produced. However, metal iron particles could be produced when the iron complex was refluxed in N2 atmosphere for 12 hours with sodium borohydride, of which amount was 60 times greater than the complex in molar ratio. The purity of the product was about 91.2%, and the particle size was 10 to 20 nm. Received October 24, 1989
The penetration of a news ink into paper stocks having different oil resistances was examined. Ink penetration was monitored by the image analyzing system based on the reflection density of the reversed side of the printed paper. The penetration depth increased in proportion to the square root of time before it reached an equilibrium state. Ink penetration was depressed by the oil resistant agent which was adsorbed on the interior of paper with irregular pore structure. The dependence of penetration depth on time varied widely corresponding to the irregularity of pore structure of paper. The standard deviation of the penetration depth immediately after ink transfer was not affected by the oil resistant agent. However, with increasing time, the influence of oil resistant agent on the standard deviation became greater. The greatest standard deviation was found on the sample stock including 0.1% of the oil resistant agent. Ink penetration behavior can be predicted by the percolation theory. When the ink was pressed into the pores of the stock under the printing pressure, it was found that the quantity of the initial penetration did not depend on the quantity of the oil resistant agent in the paper stock.