| 摘要 |
The preparation of pyrophosphorus compounds is described; the process is based on the reaction of 2 mol equivalents of a compound of the formula <IMAGE> in which X denotes oxygen or sulphur, n denotes zero or 1, and Hal denotes chlorine or bromine, and the two free valencies employed are bonded to organic substituents, with 1 mol equivalent of an oxide or carbonate of an alkali metal or alkaline earth metal or with 2 mol equivalents of a hydroxide or hydrogen carbonate of an alkali metal, preferably in the presence of a tertiary base. The resulting end products can be used as flame retardants for regenerated cellulose.
|
