FINE AIR BUBBLE HETEROCYCLIC POLYMER STRUCTURE

摘要

1473946 Microcellular coating EXXON RESEARCH & ENG CO 25 April 1974 [3 May 1973] 18075/74 Heading B2E [Also in Divisions B5 and C3] Coatings are made from a cellular solid heterocyclic/aromatic polymer comprising an aromatic polymer having repeating units, each unit having one aromatic nucleus and one 5- membered heterocyclic ring where X is and wherein at least two carbonyl groups are present and separated by a N atom and which has been made by precipitation from a solution. The coatings are made by forming a solution of the polymer in a solvent, casting the solution onto a substrate, exposing the coating to a non-solvent in vapour or liquid form thereby precipitating solid polymer in the presence of the non-solvent, removing solvent from the solid polymer and recovering the coated article.