Photoresist material based on polystyrenes

A polymer having a molecular weight M.sub.w of 10.sup.3 to 10.sup.6 (determined by gel permeation chromatography) and containing, based on the total amount of structural units present in the polymer, 100 to 5 mol % of a structural repeating unit of formula (VII) ##STR14## wherein R.sub.1 is hydrogen, methyl or halogen, n is 2 or 3 and R is C.sub.1 -C.sub.6 alkyl, benzyl, 2-tetrahydrofuranyl, 2-tetrahydropyranyl, C.sub.1 -C.sub.6 alkoxycarbonyl, phenoxycarbonyl or benzyloxycarbonyl, or, if two substituents OR are ortho-positioned to each other, two substituents R together form an ethylene group which may be substituted by up to four C.sub.1 -C.sub.6 alkyl groups, or form a C.sub.2 -C.sub.6 alkylidene group and 95 to 0 mol % of a structural repeating unit of formula (VIII) ##STR15## wherein R.sub.2 and R.sub.3 are each independently of the other hydrogen, C.sub.1 -C.sub.4 alkyl which is unsubstituted or substituted by halogen, cyano or nitro, or are phenyl or naphthyl which are unsubstituted or substituted by halogen, C.sub.1 -C.sub.4 alkoxy, hydroxy, cyano or nitro, and R.sub.4 and R.sub.5 are each independently of the other a hydrogen or halogen atom, C.sub.1 -C.sub.12 alkyl which is unsubstituted or substituted by halogen atoms, cyano or nitro, or are phenyl, naphthyl or benzyl which are unsubstituted or substituted by halogen, cyano or nitro, C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy, or a radical selected from the group consisting of --OR.sub.6, --COOR.sub.7 and --COR.sub.8 or, together with a divalent radical of formulae (IX)--(XI) are ##STR16## wherein R.sub.6 and R.sub.7 are each independently of the other hydrogen, C.sub.1 -C.sub.12 alkyl which is unsubstituted or substituted by halogen, cyano or nitro, or are phenyl or naphthyl, unsubstituted or substituted by halogen, cyano, nitro, C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy, and R.sub.8 has the same meaning as R.sub.6 or is the radical ##STR17## wherein R.sub.9 and R.sub.10 have each independently of the other the same meaning as R.sub.8.