PURPOSE: To form a film excellent in mechanical strength and clouding preventing characteristic on a support body by blending a (meth)acrylic acid monomer, a (meth)acrylate monomer, a cross-linking agent, and a specified polymerization initiator.

CONSTITUTION: A monomer mixture of (A) 40-80wt.% of a (meth)acrylic acid monomer and (B) 20-60wt.% of a (meth)acrylate monomer of the formula (R is H or CH3; R' is C1-4 lower alkyl, or lower hydroxyalkyl in which the alkyl has 1-4 carbons) (e.g.; methyl methacrylate); (C) 1-15wt.%, to the monomer mixture, of a cross-linking agent which is preferably a multifunctional acryl monomer or oligomer (e.g.; 1,4-butanediol diacrylate); and (D) 0.1-5wt.% to the monomer mixture, of a polymerization initiator by action ultraviolet ray (e.g.; benzyl dimethylketal) are blended.