To trace the corrosion state of painted steel panels by the electrochemical methods, new instrument based on potentiostat was developed. The characteristics of this instrument are to have high impedance (more than 1014Ω) in stock and to be able to measure high sensitive electrolysis currents (10-12A) The electric resistance of paint films with lesser effect as possible of electric field and corrosion currents for micro defect parts of no paint films were measured by the automatic measurements of electrode potential for painted steel panels for a long period and application of pulse polarization. The values of iron weight calculated from corrosion currents and corrosion times accords with the values of corrosion loss weights of iron which were measured by atomic absorption spectroscopy. Comparing the values of iron weight calculated from corrosion currents and corrosion time with the estimation of the results of salt spray tests by naked eyes observation, it is recognized that in one case both observation results are coincident and in another case they are not. Judging from the corrosion style in micro defect parts with no paint film, in the former case the pitching corrosions arc occured, and in the latter case the general corrosion are occured. Combining the observation by naked eyes of paint steel panel and the value of corrosion loss weight of iron by polarization method, the corrosion state are deduced precisely and more effective estimation can be expected.
Cuprous oxide and yellow mercuric oxide have been used as main toxic agents for antifouling paints. However, they have some disadvantages. They corrode light metals, and cuprous oxide changes to black cuprous sulfide due to sulfides in city-fouled water and changes to cupric oxide by air-oxidation in the paint film along the water-line. Cuprous sulfide and cupric oxide thus formed do not have antifouling effect. In the present investigation, some new kinds of antifouling paints were prepared of various toxic agents and submitted to the sea-water immersion test for a period from May to September, when sea-organisms grow most livelily. As a result, organic toxic agents showed the selective antifouling effect to sea-organisms. It was also shown that zinc phosphide has the excellent antifouling effect. There is a possibility to make a new kind of excellent antifouling paint which is not influenced by sulfides or air oxidation, and not corrosive to light metals.
The silica gels were effectively treated in an autoclave with n-hexane solution of alcohol in the Presence of the propylamine even at an appreciably lower temperature and pressure than the critical point of n-hexanewhich is the usual conditions for the surface-treatment. Since there was no any characteristic absorption due to amine, but marked surface group absorption in IR spectra of thus surface-treated silica gels, the propylamine was found to enhance catalytically the esterification of a surface silanol with an alcohol. The silica gels treated with alcohol were spreaded over the water surface like an oil on water, but these hydrophobic natures were converted into hydrophilic nature by shaking it in a few hours at room temperature after adding ammonia into water phase. The dissolution of surface group and no any trace of ammonia were found from IR absorption spectra of the silica gels after hydrolysis at room temperature in the presence of ammonia. In the absence of ammonia, the dissolutions of the surface group to the same order as mentioned above were found to be necessary to react almost ten hours at 80 to 90°C. These showed that the ammonia promoted significantly the hydrolysis of esterified silica gels. The relationship between surface areas and the numbers of surface group of the esterified silica gels after hydrolysis indicates the same tendency as that presented previously. The mechanism of these catalytic reactions was discussed.
The authors developed the mini-computer program system composed of autospectrophotometer (EPR2 HITACHI) and mini-computer (JEC-5 JEOL) for color specification and color matching on cosmetic development. Whoever needs color specification and color matching can complete his purpose simply and correctly in short time by using this program system. Color specification program is mainly used for color arrangement in new color development and color control in cosmetics production. Especially “Recommended Munsell Color Specification” program is very convenient and is possible to convert spectrophotogram into HV/C in a few minutes. Color matching program is used for formulation of new cosmetic color and correction of colorants variation, so that trial and error work based on experience is progressing to objective and reasonable work. Color difference between standard and sample formulated according.to output data from computer is possible to be ΔE (N. B. S. unit) <<1.