| 摘要 |
1,215,185. Aromatic polyamide solutions. MONSANTO CO. 8 July 1968 [6 July, 1967], No. 32513/68. Heading C3A. Substantially neutral aromatic polyamide solutions are obtained by (i) forming a slurry of an aromatic diamine solution and anhydrous calcium or magnesium carbonate and cooling it to 10‹ to -30‹ C.; (ii) forming a reaction mass containing not more than 0À02 wt. per cent of water from the cooled solution and an aromatic diacid halide and allowing polymerization to occur while keeping the temperature below 20‹ C.; and (iii) heating the reaction mass to 40‹ to 90‹ C. to effect neutralization. The amount of carbonate may be 90 to 100 equivalent per cent based on the theoretical amount of HCl released during polymerization. The solutions, e.g. in dimethylacetamide, may have a pH or 3 to 3À5 and an inherent viscosity of 2 or higher and may be spun into fibre. In the examples the polyamide is poly - m - phenylene - bis(mbenzamido) terephthalamide. |
