Photopolymerizable compositions containing prepolymers with olefin double bonds and titanium metallocene photoinitiators

Claim 1

A photopolymerizable composition which comprises, (a) a prepolymer which contains identical or different recurring structural units of the formula I ##STR51## and which reacts, when heated, to form a thermostable ring structure, and (b) a photoinitiator, wherein the photoinitiator (b) is a metallocene of the formula II ##STR52## wherein R 1 is each independently unsubstituted or substituted cyclopentadienyl.sup.⊖, indenyl.sup.⊖, or both symbols R 1 together are an unsubstituted or substituted radical of the formula III ##STR53## R 2 is a carbocyclic or 5- or 6-membered heterocyclic aromatic ring which is substituted in at least one of the two ortho-positions relative to the metal-carbon bond by a fluorine atom, R 3 is C 3 -C 5 alkynyl, substituted or unsubstituted phenylalkynyl containing 3 to 5 carbon atoms in the alkynyl moiety, N 3 , CN, Si(R 7 ) 3 or Sn(R 7 ) 3 , or has the meaning of R 2 , or R 2 and R 3 together are a radical of the formula IV --Q--Y--Q-- (IV), R 4 is a tetravalent aromatic radical after removal of four functional groups, with any two functional groups being adjacent and→denoting structural isomers, R 5 is a divalent aliphatic, cycloaliphatic or monocyclic or polycyclic aromatic radical, or aromatic radicals which contain a --CONH 2 or --COOH group in the ortho-position to the bond to Z', R 6 is a radical containing a photopolymerisable olefinic double bond, R 7 is C 1 -C 12 alkyl, C 5 -C 12 cycloalkyl, C 6 -C 16 aryl or C 7 -C 16 aralkyl, Z is --COO--, --CONH--, --O--, --NH--, --COOH/NR 14 R 15 -- or ##STR54## wherein/between amine and carboxyl groups denotes as ionic bond, Z' is --CONH--, --NHCO--, --NH--CO--NH-- or --O--CO--NH--, and each of R 14 and R 15 is independently alkyl or alkenyl each having up to 6 carbon atoms, with the proviso that, on heating the photopolymerisable composition to remove the radical R 6 , either Z and Z', or Z and Z' together with --CONH 2 or --COOH groups contained in R 5 , form a thermostable ring system, X is (CH 2 ) n , in which n is 1, 2 or 3, C 2 -C 12 alkylidene, cycloalkylidene containing 5 to 7 ring carbon atoms, Si(R 7 ) 2 or Sn(R 7 ) 2 , Q is a carbocyclic or heterocyclic 5- or 6-membered aromatic ring, each of the two bonds being in the ortho-position to the group Y and each meta-position to the group Y being substituted by a fluorine atom, and Q may contain further substituents, and Y is CH 2 , C 2 -C 12 alkylidene, cycloalkylidene containing 5 to 7 ring carbon atoms, a direct bond, NR 7 , O, S, SO, SO 2 , CO, Si(R 7 ) 2 or Sn(R 7 ) 2 .