Method for the preparation of layer structures

In a method for the preparation of highly heat-resistant layered structures soluble in organic solvents comprising:

• a. applying a coating of a radiation-sensitive, preliminary polymer to a substrate in the form of a layer or a foil;
• b. irradiating the radiation sensitive layer or foil through negative patterns;
• c. removing the non-irradiated layer or foil to form a relief structure;
• and
• d. annealing said relief structure;
• the improvement which comprises using as said radiation sensitive preliminary polymer a solvent soluble preliminary polymer comprising a polycondensation product of a primary diamine with bicyclo[2.2.2.]octene-7-tetracarboxylic acid-2,3,5,6-diester-bis-acid chloride or with a mixture of said bicyclo[2.2.2.]octene with a compound selected from the group consisting of an aromatic di-ortho-tetracarboxylic acid diester-bis-acid chloride, an aromatic di-ortho-tetracarboxylic acid-bis-anhydride and mixtures thereof;
• wherein the ester groups of said bicyclo[2.2.2.]octene-7-tetra-carboxylic acid-2,3,5,6-diester-bis-acid chloride and said di-ortho-tetracarboxylic acid diester-bis-acid chloride are in ortho position with respect to said acid chloride groups, said ester groups containing radiation reactive radicals selected from the group consisting of:
• ##STR5## wherein R.sub.1 is alkylene or aralkylene;
• R.sub.2 is hydrogen, CH.sub.3 or Cl and R.sub.3 is hydrogen;
• ##STR6## wherein R.sub.4 is hydrogen or methyl;
• and R.sub.5 is oxyalkylene;
• ##STR7## wherein R.sub.6 is alkyl, phenyl, alkoxy phenyl or halogenated phenyl;
• n is 1 or 2;
• and R.sub. 7 is H, Cl, alkyl or alkoxy;
• ##STR8## wherein R.sub.8 is a carbocyclic or heterocyclic aromatic radical bound via a ring carbon atom, and wherein said radiation-sensitive preliminary polymer is prepared in a hexamethyl phosphoric acid triamide solution.