FLAME-RETARDANT FILAMENTS

摘要

1468799 Polymeric phosphazene derivatives COURTAULDS Ltd 18 June 1974 [19 June 1973] 28972/73 Heading C2P [Also in Division C3] The invention comprises a substantially waterinsoluble phosphazene polymer of the general formula wherein n is at least 3, preferably 3 or 4, and in which the P atoms carry (a) substituents OR or SR where R is an unsubstituted or halogensubstituted alkyl or alkenyl group having up to 6 C atoms, C 6 -C 10 aryl group or C 7 -C 10 alkyl-aryl group, the various Rs being the same or different and (b) -OR2O- substituents which are either doubly substituted on one P atom to form groups of the Formula II or are substituted on P atoms from different phosphazene polymer units to form crosslinking groups of the Formula III R2 being an alkylene group of 2 to 6 carbon atoms and the molar ratio of OR and SR groups to -OR2- groups being in the range of 2 : 1 to 10 : 1, provided that when SR groups are present in the crosslinked phosphazenes there are sufficient OR groups present to provide the crosslinking groups of Formula III. The products of Formula II may be obtained by reacting a phosphonitrilic chloride with a diol (R2OH) 2 in molar proportions of 2 : 1 to 6 : 1 and then reacting with an alcohol or phenol ROH or mercaptan RSH, or alkali metal derivative thereof in an amount sufficient to replace the remaining chlorine atoms of the phosphonitrilic chloride. The crosslinked compounds of Formula III can be obtained by reacting a phosphonitrilic chloride with a compound ROM and optionally a compound RSM wherein M is H or an alkali metal and simultaneously or subsequently with a diol: HOR2OH, the reactants being used in specified molar proportions. The phosphonitrilic chloride may be linear or cyclic and may be a pure isomer or mixture of isomers. The substitution reactions can be carried out in the presence of an acid acceptor such as pyridine. Examples are given for the production of products in which the groups present on the P atoms are (1) propoxy and ethylene dioxy, (2) ethoxy and ethylenedioxy, (3) propoxy and -O(CH 2 ) 6 O-, and (4) propoxy and -O(CH 2 ) 4 O-. The products are useful as flame-retardants for regenerated cellulose filaments.