PURPOSE: To consume hydrogen before hydrogen becomes bubbles generating defects in a film during cathodic electrodeposition by precipitating the film formed from a polymer emulsion and a specific compd. on a surface by electrophoresis.

CONSTITUTION: A film is precipitated from a polymer compsn. containing a polymer aq. soln. or emulsion and a compd. reduced by hydrogen evoluted during precipitation. By this method, pinhole defects in the film precipitated by positive charge migration can be reduced. As the above-mentioned compd. used as a hydrogen sweeping agent, org. nitro compds. and furans are pref. The polymer film produced by the above-mentioned method is effective in a field for producing a lithographic printing method and a cathode ray tube and a field of etching, a solder resist and layer flattening. Further, a separate use is also useful in the electrodeposition of undercoating for a car body or the electrodeposition of a thermosetting or photocurable electrodeposition coating film for a can.