Patent GB-688372-A (GB)
Title: Improvements in or relating to flameproofing polymers
IPC: C08F30/02
Filed: 1948-07-15
Abstract: Polymers from a phosphoric acid compound containing the group <FORM:0688372/IV (a)/1> in which R is an unsaturated radical of 3 to 5 carbon atoms and X is an -OR group or an -NH2 group, are made by partially polymerizing the ester and then halogenating or, vice versa, halogenating and then polymerizing.  Esters specified are triallyl and trimethallyl phosphates and diallyl phosphonamide. Polymerization may be effected in bulk, solution or emulsion or using pearl polymerization technique, preferably with benzoyl peroxide as catalyst.  Solution polymerization yields thermoplastic products, whereas emulsion polymerization yields thermosetting polymers. Chlorine, bromine and fluorine may be used in halogenating.  In examples, triallyl phosphate is (1) polymerized in bulk to a bromine number of 150, brominated in ethylene dichloride, the solution neutralized by ammonia and salts removed by filtration; (2) polymerized in bulk as in (1), hydroquinone added and vacuum distilled to remove monomer.  The residue (bromine number 90) is then brominated as in (1); (3) polymerized in carbon tetrachloride, benzene, ethylene dichloride or trichlorethylene under reflux and further treated as in (2); (4) as in (1) except that polymerization is effected in carbon tetrachloride; (5) polymerized in ethylene dichloride, the polymer precipitated by adding carbon tetrachloride, redissolved in ethylene dichloride, re-precipitated to remove monomer and low molecular weight fractions, and brominated as in (1), precipitated with ethanol and re-dissolved; (6) polymerized in emulsion in the presence of polyvinyl alcohol, calcium carbonate and benzoyl peroxide and brominated with bromine in benzene with vigorous agitation; (7) polymerized in emulsion, which is diluted with water and further heated.  The resulting slurry is filtered, the powder washed with hot water and then benzene, finely ground, suspended in carbon tetrachloride and excess bromine added with stirring under reflux; (8) polymerized in emulsion, brominated by dropping in bromine at 10 DEG  C. and separating in precipitated brominated powder.  In examples (9) diallyl phosphonamide is polymerized in benzene under reflux and brominated with a solution of bromine in ethylene dichloride; (10) trimethyl phosphate is brominated in benzene to hexabromo-triallyl phosphate, neutralized with ammonia and precipitated salts filtered off. After dilution with benzene, zinc powder or sodium is added and the solution refluxed with stirring. The solution is filtered and benzene distilled off to leave a highly viscous oil.  Sulphuryl chloride may be used to chlorinate the alkene phosphates or their polymers and may also be used at -30 DEG  C. as a polymerization catalyst.  Copolymers may be prepared by introducing 1/8 mol. of bromine into triallyl phosphate and then polymerizing. The products may be used as flame-proofing agents (see Group VIII), as flame-proofing plasticizers for vinyl chloride/acetate copolymers, cellulose acetate or cellulose xanthogenate and as pigments for flame-proofing paints.  The Specification as open to inspection under Sect. 91, describes a viscous oily condensation polymer soluble in acetone made by vigorously stirring at -10 DEG  C. a product of the type <FORM:0688372/IV (a)/2> with ethylene glycol in pyridine, raising the temperature to 0 DEG  C., adding water to remove unreacted ethylene glycol and salts, washing to remove acid and vaccum distilling.  This subject-matter does not appear in the Specification as accepted.ALSO:Diallyl phosphonamide is prepared by adding phosphorus trichloride to a solution of allyl alcohol in diethyl ether cooled to -20 DEG  C.  After an hour at 0 DEG  C. hydrogen chloride formed is removed by passing first dry air and then anhydrous ammonia through the solution, the precipitated ammonium chloride filtered off and the ether removed by distillation to yield water-white diallyl phosphite.  Anhydrous ammonia is passed through a solution of the phosphite in benzene and carbon tetrachloride to form diallyl phosphonamide, ammonium chloride, which is filtered off, and chloroform, which is removed with the benzene under vacuum. Hexabromo-triallyl phosphate is prepared by adding bromine in benzene slowly with stirring to triallyl phosphate, passing anhydrous ammonia through to remove excess bromine and neutralize the solution and filtering off precipitated salts.