Flame retardant polyester article, method for the production of the same and compositions for retarding the flammability of polyester article

DETAILED DESCRIPTION OF THE INVENTION The halogenated phosphoric ester used for the flame detardant composition according to the invention may be selected from the group consisting of tris(2,3-dibromopropyl)phosphate, tris (2,3-dichloropropyl)phosphate, tris (2-chloroethyl)phosphate and tris (bromochloropropyl)phosphate.
The above mentioned halogenated phosphoric ester is emulsified with use of a nonionic surfactant emulsifier which may be a compound obtained by esterification of a polyethylene glycol ether or a polypropylene glycol ether of a higher alcohol or an alkylphenol with a phosphoric esterifying agent.
The phosphoric esterifying agent may be a member selected from the group consisting of phosphorus pentoxide, phosphorus oxychloride and phosphorus trichloride.
More desirably, the nonionic surfactant emulsifier may be a compound obtained by phosphoric esterification of an addition product of 5 to 15 moles of ethylene oxide to a saturated or unsaturated alcohol having 8 to 20 carbon atoms.
One of the most preferred compounds for the emulsifier is a monophosphoric ester obtained by esterification of an addition product of 5 to 15 moles of ethylene oxide to a saturated or unsaturated alcohol having 8 to 20 carbon atoms with phosphorus pentoxide.
Any conventional methods may be utilized to synthesize these esters used as emulsifiers.
For example the synthesis of monoesters with use of phosphorus pentoxide may be carried out in such a manner as disclosed in Japanese Patent Publication No.
14,416 of 1966.
The amount of the above mentioned nonionic surfactant emulsifier should be within the range of 5 to 20% by weight with respect to the amount of the halogenated phosphoric ester.
The aqueous emulsion of a halogenated phosphoric ester prepared according to the invention shows a good stability with use of a small amount of the specified emulsifiers in addition to the fact that no appreciable degradation of the antiflamable property of the halogenated phosphoric ester can be formed.
Further, in some cases, if the amount of the emulsifier is properly controlled, the flame retardancy can be enhanced in comparison with the case of utilizing the halogenated phosphoric ester in an organic solvent solutions without any emulsifier