| 摘要 |
A process for the manufacture of polyamides, polyamide-imides and polyimides which process comprises preparing a salt of an aliphatic or aromatic diamine or a mixture of these and di, tri or tetracarboxylic acid or mixture of these or their corresponding anhydride by reacting both feedstocks at a temperature of about 300 to 500 DEG F in solvent medium provided the water content of the resulting solution is below 25% water by weight the resulting salt solution is subjected to a pressure of about 1500-3000 psig and is then passed through a preheat zone where the temperature is increased to about 625 DEG F, the total residence time is kept at about 25 to about 50 seconds. The reactants are flashed through a control valve or nozzle to give an aerosol mist at a pressure of about 0-400 psig, the polymerization is further carried out in a flash reactor with a high heat flux and with wall temperatures of about 600 DEG F to about 1000 DEG F and melt temperatures of about 500 DEG F to about 750 DEG F, the total polymer residence time in the reactor is kept about 0.1 to about 20 seconds. The novel compositions are useful for engineering resins. Also a process for the manufacture of polyesters and polyarylates by the process disclosed above, except that instead of a salt, a prepolymer is prepared and the reactants for polyesters are dicarboxylic acids and glycols, for polycarbonates, diphenols and phosgene, for polyarylates, diphenols and dicarboxylic acids and for polyesterarylates, dicarboxylic acids and phosgene. |
