PURPOSE: To obtain a precoated steel plate having excellent weather resistance and stain resistance, by forming film coating layers on a steel plate such as a molten galvanized steel plate with an undercoating coating compound, option ally a middle coating compound and a topcoating coating compound having a specific composition.
CONSTITUTION: A steel plate such as a hot-dip galvanized steel plate, a cold rolled steel plate or an electric galvanized steel plate is provided with an undercoating film layer by an undercoating coating compound, optionally a middle coating film layer by a coating compound of middle coating and a topcoating layer by a topcoating compound composed of one or more compositions comprising (A) a compound containing two or more functional groups of the formula (R1 to R3 are each H or a 1-18C organic group; R4 is a 1-18C organic group; Y1 is O atom or S atom) in one molecule, (B) a compound (e.g. bisphenol type epoxy resin) containing two or more reactive functional groups (epoxy, oxazoline, silanol, amino, etc.) to be chemically bonded to the functional group of the component A by heating in one molecule and optionally (C) one or more compositions comprising a heat latent acid catalyst as essential components to give the objective steel plate.
KATSUYAMA HIROKI
MIZUTANI HIROKI
ISHIDOYA MASAHIRO
