The authors studied the effects of grain size of chromic oxides and the constituents and blending ratio of fatty acids on the gloss-buffing ability.
The results obtained were as follows.
(1) The optimum buffing effects were given by 0.4-0.5μ of average grain size of chromic oxides.
(2) The most desirable fatty acid to be added to grease-base buffing compounds was myristic acid and its blending ratio was 17%.
(3) 18Cr-8Ni stainless steel was more easily polished than 13Cr or 18Cr steel by the same grease-base buffing compound.
(4) For 18Cr-8Ni and 13Cr steels, there were found almost no differences of polishing between work-hardened metals and annealed ones by the same buffing compound.

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The effects of organic anions on the curve representing differential capacity (C) at the interface of iron-perchloric acid solution against electrode potential (E) were measured. Three peaks on the above C-E curve of Fe-HClO₄ system containing no additives were suppressed by the addition of organic acids, while new peaks due to the adsorption of the acids appeared. Coadsorption of ClO₄^- happened with acetate and propionate ions, but not with citrate ion. These findings should be interpreted as due to adsorption of citrate ion more irreversible than the other two. As the results of the present experiment, the ascending order of the covering power of surface was as follows.
Acetate<propionate<citrate

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Increase of the covering power of the surface of iron in perchloric acid solution caused by the synergistic action of organic anions and amines was measured by electrical double layer capacity at the interface. The covering power increased by the addition of amine into Fe-0.5N-HClO₄ system containing sodium propionate, but it decreased by the addition of a larger amount of amine. These findings should be interpreted as adsorption of amines as ammonium ions over the previously adsorbed propionate ions; however, as the results of electrostatic interaction between anions and cations, anions would migrate from the iron surface together with ammonium cations with the increase of amine concentration.
Accordingly, the synergistic effects of amines and anions would be attributed to the overlapped adsorption of ammonium ions over the anions, and these effects should be quite distinct from the coadsorption mechanism of amine and halide ions.

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The stability of pH of electrolyte composed of zinc-diamine chelate was investigated to determine the optimum condition for electrodeposition of zinc.
The following results were obtained.
(1) The current density-deposition potential curve indicated that stable complex ion of (Zn(En)₃)⁺⁺ or (Zn(Pn)₃)⁺⁺ was formed in the range of pH 9-13. When alkalinity was more stronger, the effects of zincate ions were more predominant on electrolysis.
(2) Complex ions were much affected by anions. The deposit of zinc was not excellent, when it was obtained from alkaline solution containing a large amount of sulfate ions.
(3) When pH range was in acidic or in strong alkaline, complex ions of diamine with zinc were not formed. In this case, diamine reacted only as an addition agent on electrolysis and made the deposit more compact, but the chromate coating on the deposit obtained from such a solution was not so excellent.
(4) The deposit of zinc on steel strip obtained from the solution containing gelatine in pH range of 9-13 was so compact that it was as excellent as the deposit from the conventional cyanide baths. However, the pH range should be limited to 9-12, because the dissolution of zinc anode was incomplete at pH 13. The optimum condition for electrolysis was as follows, when cathode current efficiencies were 95-97%.
When Pn was used
En 1.8-2.4mol/l 1.5-1.8mol/l
ZnCl₂ 0.6-0.8mol/l 0.5-0.6mol/l
NaCl 0.4mol/l
Gelatine 0.5-1.0g/l
pH 9-12
Temperature Room Temperature
Cathode current density 1.0-3.5A/dm² 1.0-3.0A/dm²

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Effects of heat treatments and P content of electroless-plated nickel films on their structure were investigated by means of X-ray diffraction method and electron microscope.
As-deposited nickel films formed lamellar structure due to the change in bath composition. As the results of electron diffraction analysis, it was found that the structure of as-deposited nickel films was converted from face-centred-cubic lattice (about 4wt.% of P) into amorphous state (7.4wt.% of P). By heating at below 200°C, phosphorus atoms gradually began to diffuse, by which the crystallization of nickel was promoted. At higher temperatures, stable phosphide (Ni₃P) was found in the film. When the temperature of heat treatment was more higher, the grains of phosphide grew larger and coagulated. Nickel layer was formed on substrate iron and eutectic structure consisting of Ni and Ni₃P was observed on outer surface of the films as if the structure had been formed as a block being pressed to the surface.

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Being deduced from the mechanism of dissolving resin in the water, the authors suggested that floating method would be superior to sedimentation method in these treatments. As the results mentioned below, it was confirmed that the above suggestion would be true.
The dissolved resin was made insoluble by the action of polyvalent metallic ions, and then, the deposited resin was negatively charged in the water.
By the addition of cationic polymer coagulant, the resin was bridged and coagulated.
In general, it is considered that resins and coagulants contain some hydrophobic groups in their structure so that they are adsorbed on the surface of bubbles, introduced to the system, and float up on the water surface.

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