Polyamide-amides, their preparation and conversion to polyimides

摘要

The invention comprises polyamide-amides having recurring units of formula where R is aromatic, R1 is arylene, R2 is H, alkyl or aryl and R3 is H, alkyl, aminoalkyl or aryl. They may be prepared either by (a) reacting a tetracarboxylic acid dianhydride with a diamine to produce a polyamide-ester, (b) cyclizing this as described in Specification 1,088,727 to a polyiminolactone having repeating units of formula and (c) treating this product with an amine of formula NHR2R3 or (i) reacting a tetracarboxylic acid dianhydride with ammonia gas to produce the corresponding diimide and (ii) reacting this with a diamine in a solvent. Tetracarboxylic acid dianhydrides specified include: pyromellitic dianhydride, diphenyl 3,31,4,41-tetracarboxylic acid dianhydride, 2,2-diphenyl-propane 31,311,41,411 - tetracarboxylic acid dianhydride, diphenyl sulphone 3,31,4,41 - tetracarboxylic acid dianhydride, diphenylether 3,31,4,41 - tetracarboxylic acid dianhydride and benzophenone 3,31,4,41 - tetracarboxylic acid dianhydride. Diamines specified include m-phenylene diamine, bis - (4 - aminophenyl) methane, 2,2 - bis - (4 - aminophenyl) propane, bis - (4 - aminophenyl) ether, bis - (4 - aminophenyl) sulphone and 1 - isopropyl - 2,4 - diaminobenzene. Cyclizing agents (b) specified include N,N1-dicyclohexylcarbodiimide in a mixture of dimethyl formamide and dimethyl acetamide, propionyl fluoride, valeryl fluoride, bromoacetyl bromide, thionyl chloride, acetyl chloride, phenylphosphonyl dichloride, chloracetic anhydride, and trifluoracetic anhydride. Amines specified for step (c) include ammonia bubbled through a benzene solution, dimethylamine, aniline and ethylene diamine. This reaction may be at 15-100 DEG C. The diimide-diamine reation (ii) may be at 75-150 DEG C. Solvents specified include dimethylsulphoxide. Fillers and foaming agents may be introduced into the polyamide-amides and they may be made into shaped articles, e.g. films, by shaping the polyamide-ester before cyclization and amination or by shaping a solution of the polyamide-amide. They may also be used as laminate adhesives. Polyimides are produced by heating the polyamide-amides to at least 150 DEG C.ALSO:Solutions of polymers having recurring units of formula: where R and R1 are aromatic, the 4 carbonyl groups being in pairs the members of each pair being on mutually ortho or peri carbon atoms in R, R2 is H, alkyl or aryl and R3 is H, alkyl, aminoalkyl or aryl may be applied to surfaces and heated to convert them to the corresponding polyimide. The coatings may be applied by doctoring, rolling, dipping, brushing or spraying. Substrates specified are copper, brass, aluminium, steel, glass, regenerated cellulose, wood, paper, polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyamides, polyimides, polytetrafluoroethylene, copolymers of tetrafluoroethylene and hexafluoropropylene and polyurethanes. The substrate may be metallized before coating.