| abstract |
PURPOSE: A novel flame retardant capable of flame retarding a high polymer material without degrading the properties thereof, comprising a 9-phospha-10-oxaphenanthrene compound prepared by dehydrogenating a salt of 2-(2'-hydroxyphenyl)phenylphosphonous acid with heat. n CONSTITUTION: An alkali (earth)metal salt of a 2-(2'-hydroxyphenyl)-phenylphosphonous acid of formula I (X 1 WX 8 are H, halogen, alkyl, aryl, halogen-substituted aryl or aralkyl groups) is dehydrogenated in a solvent, e.g. ethylene glycol, at 130°C or above, and coagulated with an acid, e.g. hydrochloric acid, to give the objective 9, 10-dihydro-9-hydroxy-9-phospha-10-oxaphenanthrene-9-oxide compound of formula II. n EFFECT: Effective even in a very small amount, good compatibility with substrates, without degrading the transparency of the substrates after addition thereto. n COPYRIGHT: (C)1980,JPO&Japio |