Flame-proofed foamed materials

The invention comprises flame - resistant foamed materials prepared by reaction between polyesters and polyisocyanates, characterized in that an inorganic phosphate is incorporated in the reaction mixture before the foaming reaction is complete. Suitable phosphates are sodium phosphate, calcium phosphate, sodium borophosphate or (preferably) an ammonium phosphate, e.g. mono- or diammonium phosphate or ammonium magnesium phosphate. Water-insoluble oxides, e.g. iron, titanium or antimony oxides may also be incorporated. The polyesters may be alkyd resins having free hydroxyl groups, prepared from trihydric alcohols with optionally dihydric alcohols and mixtures of adipic and phthalic or of succinic, sebacic and optionally phthalic acids. Examples describe the preparation of foams by adding toluylene-2 : 4-diisocyanate to a mixture of (1) an adipic acid/phthalic acid/glycerol polyester, an adipic acid/ethylene glycol/glyerol polyester, an octylcresol/ethylene oxide condensate, zinc naphthenate, ethyl cellulose solution, antimony oxide and ammonium phosphate; (2) an adipic acid/phthalic acid/hexanetriol polyester, an adipic acid/ethylene glycol/glycerol polyester, an octylcresol/ethylene oxide condensate, zinc naphthenate, ethyl cellulose, antimony oxide and magnesium ammonium phosphate. Specifications 547,672, 553,733, 579,340, [all in Group IV], and 790,420 are referred to.