APPLICATION OF TRIARYL PHOSPHATE TO PHOTOSENSITIVE MATERIALS (III) - STRUCTURE AND REACTIVITY OF METHYL-SUBSTITUTED TRIARYL PHOSPHATE

Six methyl-substituted triaryl phosphates (TAPs) were synthesized for application as acid generators for thermodeveloping type photosensitiv e materials [(Aryl-O)(3)PO;Aryl group, 2-tolyl (ToTP), 3-tolyl (TmTP), 4-tolyl (TpTP), 2,6-xylenyl (TooXP), 2,4-xylenyl (TopXP), and 3,4-xyl enyl (TmpXP)]. The TAPs yielded a bisaryl compound and a phosphoric ac id monoaryl ester equivalently after photoirradiation with 254-nm radi ation. Among these compounds, TmpXP was the most reactive yielding 3,3 ',4,4'-tetramethylbiphenyl (78%) after only 4-h irradiation. During th e photoirradiation of TAP, strong emissions were detected. Each spectr um had two emission maxima. The shorter wavelength maximum was assigne d to monomer fluorescence and the longer one to excimer fluorescence. Emission quenching was carried out by using oxygen. The photosensitivi ties of thin films of poly(4-trimethylsiloxystyrene) (PSSt) and TAP we re studied. Among the films, the PSST-TmpXP thin film was the most sen sitive (35 mJ cm(-2)).