High Efficient Photoinitiator of Hexaphenylbisimidazole Derivatives with Substituents in the 2-Phenyl Ring

Abstract

Hexaphenylbisimidazoles with methoxy and nitro substituent in 2-phenyl ring were synthesized and evaluated by UV-vis absorption spectrum, photo-dilatometer and photoresist dry film. Both methoxy and nitro group shift the UV-vis absorption spectra of HABIs to a longer wavelength by comparison with the parent HABIs. The UV-vis absorption spectrum of B1-HABI exhibits a 13nm redshift than TCTM. Photo-dilatometer experiments indicate that their photoinitiating efficiencies are higher except B3-HABI. The dry film photosensitivity of B1-HABI at 365nm and 405nm are much better than traditional HABIs.