| 摘要 |
<p>1417568 Poly-(aromatic oxadiazole) fibres MONSANTO CO 24 Nov 1972 [26 Nov 1971] 54323/72 Heading B5B Fibres of poly-(aromatic oxadiazoles) are prepared by wet-spinning a solution containing between 1% and 15% by weight polymer in a strong sulphuric acid as solvent. The solution is extruded downwards through a gas and then into an aqueous coagulation bath comprising water or an aqueous solution of the said acid. The water content of the bath is at least 30% by weight. The formed fibre is withdrawn from the bath, and may be washed and then dried. The polymer has recurring units of formula and units of formula the units being present in a respective mole ratio of 20 : 80 to 95 : 5. In the above formulae Ar and Ar<SP>1</SP> are divalent aromatic radicals and R is an alkyl radical containing from 1 to 4 carbon atoms. The fibre may be drawn at elevated temperatures. Reference has been directed by the Comptroller to Specification 1,252,508.</p> |
