| 摘要 |
1,254,003. Polyamides. IMPERIAL CHEMICAL INDUSTRIES Ltd. 23 June, 1969 [23 July, 1968] No. 35046/68. Headings C3C and C3R. A process for producing polyamides comprises reacting a bis(aminophenyl) sulphone with a dicarboxylic acid at 160‹ to 300‹ C. in an inert atmosphere and the presence as catalyst of the product formed by adding hypophosphorous acid or its salt with an organic base R-SO 2 -Ar-NH 2 (where R is a monovalent hydrocarbon group or an amino-substituted monovalent hydrocarbon group and Ar is a divalent aromatic group) to the reaction mixture at below 150‹ C. The acid may be a C 6-16 polymethylene or aromatic dicarboxylic acid. Additives, e.g. heat and light stabilizers, lubricants, fillers, mould release agents and plasticizers may be included. The polymerization may be effected in two stages (i) at 160‹ to 240‹ C. under reflux and (ii) at 220‹ to 270‹ C. at a pressure of 1 mm. Hg or less. The products are amorphous transparent polymers which can be moulded to fibres or thicker articles without crystallizing. When the acid is aromatic films, fibres and coatings may be obtained from solutions. Examples compare the physical properties, solubility in formic acid, dimethyl formamide or sulphoxide and sulphuric acid and processability of the polymers with those obtained using other catalysts. In several examples the product is a rigid tough foam. Reference is made to Specifications 1,113,824 and 1,161,124. |
