Photocrosslinkable polyester with side tricyclic imidyl groups

Claim 1

A photo-crosslinkable polymer, which has an average molecular weight between 1,000 and 50,000, as measured by inherent viscosity on a 0.5% by weight solution in cyclohexanone at 20° C. and which has side imidyl groups of the formula (I) ##STR44## in which R and R 1 independently of one another are hydrogen, halogen, alkyl having 1-4 C atoms or methoxy, A is --CH 2 --, --CH 2 CH 2 -- or --OCH 2 -- with the oxygen atom bonded to the aromatic ring and E is hydrogen, or A is --O-- and E is --CH 3 , the proportion of imidyl groups of the formula I being at least 5 percent, based on the number of recurring structural elements in the polymer, said polymer being a polyester which is a homopolycondensation product or a copolycondensation product of a dicarboxylic acid or ester forming derivative thereof with a dihydroxy or diglycidyl compound, wherein said polymer comprises (a) from 5 to 100 percent, based on recurring structural elements in the polymer chain, of molecular chain members of the formula XV ##STR45## in which Z 3 and Z 4 are --O--, and G is an aliphatic radical having at least 2 C atoms or a cycloaliphatic, araliphatic, carbocyclicaromatic or heterocyclic-aromatic radical, or Z 3 --G--Z 4 -- is a grouping of the formulae ##STR46## the two carbonyl groups in the formula XV being bonded to the benzene ring in the meta- or para-position relative to one another, and (b) from 95 to 0 percent, based on recurring structural elements in the polymer chain, of structural elements of the formula XVII ##STR47## in which Z 3 , Z 4 and G are as defined under formula XV, m and r are each the number 1, and G 1 is an aliphatic radical having at least 2 C atoms or a cycloaliphatic, araliphatic, carbocyclic-aromatic or heterocyclic-aromatic radical.