PURPOSE: The titled composition, obtained by incorporating a curable unsaturated radically reactive resin having a specific acid value with a specific alkyd resin in a specific proportion, and capable of forming films having improved rust preventing property, dealkalizing property of the films and machine oil resistance, etc.

CONSTITUTION: A temporary rust preventing composition obtained by incorporating (A) 60W90wt% unsaturated radically reactive resin having 10W60 acid value, e.g. an unsaturated epoxy resin, curable with active energy radiation, e.g. a high-pressure mercury lamp, and if necessary an unsaturated radically reactive monomer, [e.g. 2-hydroxyethyl (meth)acrylate], with (B) 10W40wt% alkyd resin having ≥45% oil length and 10W20 acid value, e.g. castor oil.

EFFECT: Improved storage stability and coating performance, etc.