Polyamidester und Polyimide sowie Verfahren zu ihrer Herstellung

摘要

Linear film-forming aromatic polyamideester polymers consisting of recurring units where R is a tetravalent aromatic group, R1 is arylene and R2 is alkyl or aryl may be prepared by reacting the appropriate diester diacyl halide with a diamine H2N-R1-NH2. Numerous possibilities are listed for the groups R, R1 and R2. They may be formed into shaped articles or coatings and converted in situ to the corresponding polyimide. In specific examples polymers are prepared from 2,5-dicarboethoxy terephthaloyl chloride (diethyl pyromellitate diacid chloride) or 2,5-dicarbo-(beta-cyanoethoxy)terephthaloyl chloride and bis(4-aminophenyl)propane, m-phenylene diamine or 4,41-diaminodiphenyl ether or sulphone. Compositions and foamed products.-Before conversion to polyimide the polymer or a solution thereof may have incorporated therein other polymers or pigments, conductive carbon black, metal particles, abrasives, dielectrics or foaming agents. Foamed products may also be obtained by dispersing bubbles of air, carbon dioxide or nitrogen in a melt or solution before cyclization. Specified solvents include N,N-dialkylcarboxylamides, dimethyl sulphoxide, N - methyl - 2 - pyrrolidone, tetramethyl urea, pyridine, dimethyl or tetramethylene sulphone, hexamethylphophoramide, formamide, N-methyl formamide and butyrolactone. They may be diluted with cyclic hydrocarbons, benzonitrile, dioxane or acetone.ALSO:Solutions of polyamide-ester polymers having recurring units where R is a tetravalent aromatic group, R1 is arylene and R2 alkyl or aryl (see Division C3) are used as coating compositions. They may be applied by doctoring, rolling, dipping, brushing or spraying to various substrates e.g. metals or polymers (extensively exemplified), asbestos, glass, leather or fabrics in the form of sheets, fibres, foams, fabrics, wires or screens. Filler and/or foaming agents may be included in the composition and the resulting coating may be converted to a polyimide by heating above 125 DEG C. or treatment with a monocarboxylic acid anhydride.