COATING COMPOSITION FOR PRECOATED STEEL PLATE, PRECOATED STEEL PLATE EXCELLENT IN FORMING PROCESSABILITY AND CREAK RESISTANCE, AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain the subject composition capable of providing precoated steel plates having high coating film hardness and axcellent forming processability under severe forming process conditions, and also excellent in creak resistance, by including a specific polyester compound, a curing agent and organic resin beads, etc., in a specific proportion.;SOLUTION: This composition is obtained by mainly including, based on the resin solid content, (A) 1-15 wt.% of a polyester compound with the main recurring unit of formula I ((n) is 2 to 10; R is a polyoxymethylene, neopentylene or the like; and R' is formula II or the like), (B) 40 to 90 wt.% of a polyol except the component A, and (C) 9 to 50 wt.% of a curing agent comprising, pref. a blocked polyisocyanate compound, and including (D) 0.3 to 30 pts.wt. of organic resin beads pref. such as of a urethane resin with an average particle diameter of pref. 0.1 to 10 μm (a value converted to the diameter of a sphere having the same volume), based on 100 pts.wt. of the resin composition (weight of the coating composition except the component D) on a solid basis.;COPYRIGHT: (C)2001,JPO