2 4 5 triarylimidazole dimers and a mixture thereof preferably the photoinitiator is 2 4 6 trimethylbenzoyl diphenyl phosphine oxide according to the present invention the solvent suitable for the above mentioned composition is not particularly limited and can be selected from the group consisting of n methylpyrrolidone nmp n n dimethylacetamide dmac n n dimethylformamide dmf dimethyl sulfoxide dmso toluene xylene and a mixture thereof in order to increase the photo crosslinking degree and improve the film forming properties the photosensitive composition of the present invention optionally comprises a reactive monomer or short chain oligomer for making the molecules crosslinked according to the present invention suitable reactive monomers or oligomers are not particularly limited and can be selected from the group consisting of 1 6 hexanediol diacrylate neopentyl glycol diacrylate ethylene glycol diacrylate pentaerythritol diacrylate trimethylolpropane triacrylate pentaerythritol triacrylate dipentaerythritol hexaacrylate tetramethylolpropane tetraacrylate tetraethylene glycol diacrylate 1 6 hexanediol dimethacrylate neopentyl glycol dimethacrylate ethylene glycol dimethacrylate pentaerythritol dimethacrylate trimethylolpropane trimethacrylate pentaerythritol trimethacrylate dipentaerythritol hexamethacrylate tetramethylolpropane tetramethacrylate tetraethylene glycol dimethacrylate methoxydiethylene glycol methacrylate methoxypolyethylene glycol methacrylate u03b2 methacryloyloxyethylhydrodiene phthalate u03b2 methacryloyloxyethylhydrodiene succinate 3 chloro 2 hydroxypropyl methacrylate stearyl methacrylate phenoxyethyl acrylate phenoxydiethylene glycol acrylate phenoxypolyethylene glycol acrylate u03b2 acryloyloxyethylhydrodiene succinate lauryl acrylate ethylene glycol dimethacrylate diethylene glycol dimethacrylate triethylene glycol dimethacrylate polyethylene glycol dimethacrylate 1 3 butylene.