POWDER COATING MATERIAL FOR CAST IRON PIPE

摘要

PROBLEM TO BE SOLVED: To obtain a coating material which does not suffer from gelation even during long-term storage and has excellent storage stability by using as the essential components a solid bisphenol epoxy resin having a specifiedα- glycol content and a specified hydrolyzable chlorine content and an organic acid hydrazine. SOLUTION: A solid bisphenol epoxy resin having anα-glycol content of 0.03-0.07 meq/g and a hydrolyzable chlorine content of 200 ppm or below is used. The epoxy equivalent is desirably 740-1,300 g/eq. A desirable process for producing this resin consists of reacting a liquid bisphenol epoxy resin with a bisphenol. The organic acid hydride used as a curing agent is exemplified by adipic acid hydrazide. The organic acid hydrazide is desirably used in such an amount that the equivalent ratio (the epoxy groups in the total epoxy resin component in the powder coating material)/(the active hydrogen atoms in the organic acid hydrazide) is 1.0/0.6 to 1,0/1.2.