To obtain extremely excellent corrosion resistance and adhesion property to a coating material by preparing a metal surface treating agent which contains an Al-contg. inorg. oxide containing Al, O and other elements, metal salts except for Al, and a resin and/or its precursor and which does not contain Cr.
As for the resin and/or its precursor, polyacrylates, polyesters and copolymers of these can be used for the resin, and monomers and oligomers of these are used as the precursor. These compds. are incorporated by 30 to 80 wt.% of the whole structural components. As for the metal salts except for Al, manganese phosphate or the like is used and incorporated by about 0.05 to 10 mol to 100 g of the resin and/or its precursor. As for the elements except for Al and O in the Al-contg. inorg. oxide, Si or the like is used, and the inorg. oxide is incorporated by 2 to 80 pts.wt. to 100 pts.wt. of the resin. The obtd. surface treating agent is preferably controlled to about 1.5 to 3.5 pH.
HOTTA YASUNARI
SHIMIZU TOSHIYUKI
