To provide a powder coating composition capable of improving a long term corrosion-resistance without using a substance having a high environmental load and to provide a heavy corrosion-resistant coated steel stock by using the same.
The powder coating composition comprising (A) a bisphenol F-type solid epoxy resin having an epoxy equivalent weight of 500-2,500 g/eq, (B) a terminal bisphenol F-type phenol-based hardener having a phenolic hydroxyl group of 300-800 g/eq and a softening point of 70-120°C, (C) an imidazol-based curing accelerator and (D) an inorganic pigment, is characterized in that the powder coating composition is obtained by containing the hardener (B) of a phenolic hydroxyl group of 0.6-1.0 equivalent relative to one epoxy equivalent weight of the epoxy group of the epoxy resin (A) and the curing accelerator (C) having the ratio of 0.2-5% by mass relative to the epoxy resin and by containing the inorganic pigment (D) containing (a) titanium oxide as the essential component, and at least one kind of (b) zinc phosphite, (c) zinc phosphate and (d) aluminum molybdate and besides the sum total of (D) amounting to 5-40% by mass in the powder coating composition.
COPYRIGHT: (C)2008,JPO&INPIT
TAKEDA YASUYUKI
HANABUSA MASAYOSHI
KAJINO MASAYOSHI
TOTO KASEI CO LTD
Etsuichi Matsumoto