GB1093893A - Mixtures of phosphonates, their preparation and use in polyurethane foams - Google Patents

Abstract

A foamable composition comprises (A) an hydroxyl-containing polymer having an hydroxyl number of from 25 to 900; (B) a mixture of phosphonates falling within at least two of the following classes <FORM:1093893/C3/1> <FORM:1093893/C3/2> <FORM:1093893/C3/3> wherein n is 0 or 1, R3, R4, R5\h and R6 are independently alkyl, substituted alkyl, aryl, substituted aryl, alkenyl, substituted alkenyl and heterocyclic, R1 is hydrogen or one of the groups listed under R3, R4, R5 and R6, Z i alkyl, substituted alkyl, aryl, substituted aryl, alkenyl, substituted alkenyl, alkylene or substituted alkylene, and in which the phosphonates of classes (b) and (c) each contain from 2 to 12 free hydroxyl groups and the phosphonates of class (a) contain from 3 to 12 free hydroxyl groups; (c) an organic polyisocyanate; and (d) a foaming agent. The phosphonate mixture may be employed in an amount of 0.2 to about 95% of the polyol component (e.g. a polyester or a polyether or a mixture thereof) contained in a urethane foam system which may also include a blowing agent, a catalyst and a surfactant. The polyol phosphonate may be blended by conventional means with the other components of the urethane foam system at 0-150 DEG C. In Examples 22-26 the hydroxyl-containing polymer employed is derived from trimethylol propane and adipic and the isocyanate employed is a toluene diisocyanate. In Example 27, triphenyl phosphite and isobutanol are reacted at 120-130 DEG C. in the presence of a minor amount of sodium hydride, subsequently with an oxypropylated Novolak (mol. weight 425 and off number 396) at 130-140 DEG C. and the resulting reaction mixture was isomerized by adding epichlorhydrin followed by heating at 140-150 DEG C. The product is identified as oxypropylated Novolak isobutyl epichlorhydrin phosphonate and oxypropylated Novolak isobutyl phosphonate.ALSO:The invention comprises a mixture of phosphonates falling within at least two of the following classes: <FORM:1093893/C2/1> <FORM:1093893/C2/2> <FORM:1093893/C2/3> wherein n is 0 or 1, R3, R4, R5 and R6 are independently alkyl, substituted alkyl, aryl, substituted aryl, alkenyl, substituted alkenyl and heterocyclic, R1 is hydrogen or one of the groups listed under R3, R4, R5 and R6, Z is alkyl substituted alkyl, aryl, substituted aryl, alkenyl, substituted alkenyl, alkylene or substituted alkylene, and in which the phosphonates of classes (b) and (c) each contain from 2 to 12 free hydroxyl groups and the phosphonates of class (a) contain from 3 to 12 free hydroxyl groups. The invention also includes a process for preparing a mixture of phosphonates which comprises reacting one mole of a triorgano phosphite with more than one mole, but less than three moles, of a polyhydric compound of the formula R7(OH)m in which R7 is alkylene, aralkylene, haloalkyl, aryl, alkaryl, haloaryl, alkenylene, substituted alkenylene, heterocyclic and substituted heterocyclic and m is an integer from 2 to 12, to form a mixture of phosphites, and rearranging the mixture of phosphites to form a corresponding mixture of phosphonates. The transesterification of the triorgano phosphite with the polyhydric compound is preferably effected in the presence of a conventional transesterification catalyst and the rearrangement of the phosphite to form the phosphonate may be effected by heating or by treatment with an Arbujov reagent (many being specified); the nature of the products may apparently be varied by varying the amount of Arbujov reagent employed. The reactions of the invention may be effected at temperatures of 25-300 DEG C. and the reaction may be conducted in situ without the removal of by-products until the desired phosphonate mixture is obtained.