PHOTOREACTIVE POLYMERS OF 4-VINYLBENZYL THIOCYANATE

4-Vinylbenzyl thiocyanate (VBT) was synthesized as a new monomer. It was copolymerized with styrene (ST) to poly(VBT-co-ST) and polymerized to the homopolymer (PVBT). The molar fraction of VBT in the copolymers varied between 0.05 and 0.45. The lithographic properties of the materials under deep u.v. irradiation (248 nm KrF excimer laser) were studied. Depending on the copolymer composition, the gel dose E(g) was found between 6.7 and 262 mJ cm(-2), which corresponded to quantum efficiencies Phi of intermolecular crosslinking between 12.3 . 10(-3) and 3.8 . 10(-3). The observed variation of the sensitivity with the composition of the copolymers was analogous to results obtained for halogenated polystyrenes under electron beam irradiation.