Keiji Izumi

Coating of fluorine-doped ZrO2 films on steel sheets by sol-gel method

Abstract Fluorine(F)-doped ZrO2 coatings were applied to steel sheets using organo-zirconium compounds and fluoro-alkyl silanes (FAS) as starting materials. The reactions of FAS with organo-zirconium compounds in the coating solutions were followed using gas chromatography (GC). The GC study showed that the reactions between zirconium tetra-octylate and FAS were completed within a few hours at room temperature. On completion of the reactions, the water-repellent property of the resultant coated films on steel sheets was improved.

Influence of firing conditions on adhesion of methyltrialkoxysilane-derived coatings on steel sheets

Abstract The properties of coatings prepared from methyltriethoxysilane (MTES) on stainless steel sheets (SUS) are studied under various firing conditions and discussed in connection with structural changes of the films. Microhardness and abrasion resistance of the coating films increased with an increase in the firing temperature. However, good adhesion of the coating films to SUS substrates at the formed portion was obtained in the limited range of firing temperatures from 200 to 300°C. The increasing microhardness and abrasion resistance of the coating films were due to the formation of Si O Si network and also the densification resulting from the polycondensation of Si OH groups and the burning of CH3 groups. Good adhesion of the coating films prepared from MTES to SUS substrates was ascribed to the flexible structure of the films resulting from the remaining Si CH3 and Si OH bonds.