| 摘要 |
PROBLEM TO BE SOLVED: To produce a polyorganophosphazene free from impurities such as active chlorine or an amine hydrochloride and useful in the industry at a high conversion by polymerizing at least one specified compound. SOLUTION: A substituted phosphinylphosphoimide of formula I (wherein R<1> to R<5> are each an alkyl, an aryl, an alkoxyl, an aryloxy, amino, a substituted amino, an alkylthio or an arylthio) is polymerized by heating to 14-350 deg.C in optionally a nitrogen atmosphere or a vacuum in an inert solvent to selectively obtain a polyorganophosphazene of formula II (wherein R<6> is any one group of R<1> to R<3> ; R<7> and R<8> are the two remaining groups; and R<4> and R<5> are as defined in formula II) without substantially forming any cyclic oligomer. This polyorganophosphazene is purified by dissolving it in a good solvent and adding a poor solvent to the solution to precipitate the polymer. The purified polymer is excellent in flame retardancy, heat resistance, low-temperature resistance, electrical insulation properties, chemical stability, etc. By changing the substituents of the substituted phosphinylphosphoimide, the product polymer can be endowed with characteristic properties. |
