| 摘要 |
The invention comprises a process for the production of fibre-forming linear polyamide by polymerization of a diamine-dicarboxylic acid salt with the polymerizing material maintained in finely divided solid form throughout the polymerization, wherein the salt is heated with agitation for an initial period together with at least 2% and less than 100% of its weight of an inert organic diluent under superatmospheric pressure generated or supplemented by water vapour, formed in the polymerization and diluent vapour, liquid diluent being present throughout this period and the pressure is thereafter reduced by release of vapours from the polymerization vessel while continuing heating and agitation, the temperature throughout the process at all times being below the m.p. of the polymerizing material and not more than 60 DEG C. below the m.p. of the salt. Polyamides specified include nylon 66. The inert diluent may be a solid at room temperature but a liquid at the reaction temperature or may have a m.p. below 30 DEG C. It may be a nonsolvent and may have a b.p. of 100-300 DEG C. Liquids specified include diphenyl ether, bis (2-ethoxyethyl) ether, xylene, a diphenyl ether/ diphenyl mixture, a salt of a deodorized kerosene fraction and a chlorinated diphenyl. 2-25% may be used. 1-100% of water may be present and in this case the mixture should be heated at autogenous pressure and then water allowed to escape until 0.1-25% remains. Heating to polymerize may begin at atmospheric pressure or up to 100 p.s.i.g. of an inert gas, e.g. N2 or argon, and continue at autogenous pressure in a sealed vessel. The temperature may be 240-325 DEG C. and the maximum pressure 300-1200 p.s.i.g. The reactants should be agitated by stirring or vibrating, rocking or rotating the reaction vessel and the surface temperature of the vessel should be uniform to within 50 DEG C. The reaction may be completed by allowing the pressure to drop to 0-100 p.s.i.g. and changing the temperature to 250-325 DEG C. The product may be made into a shaped article. |
