PURPOSE: To obtain the title composition having excellent flow of a solution during expansion and giving a foam excellent in flame retardancy, by mixing an aqueous solution and/or a slurry of a carbohydrate with a reaction catalyst, an isocyanate compound, a specified silicone foam stabilizer and a flame retardant.
CONSTITUTION: 50W200pts.wt. aqueous solution and/or slurry (A) of a carbohydrate, obtained by dissolving or dispersing at least one carbohydrate selected from among fruit sugar, grape sugar, sugar, malt sugar, cellulose, etc. is mixed with 0.1W5pts.wt. reaction catalyst (B) (e.g., triethanolamine), 50W200pts.wt. isocyanate compound (C) (e.g., diphenylmethane diisocyanate), 0.1W5pts.wt. silicone foam stabilizer (D) containing Xmol of silicon-bonded methyl groups, Ymol of units of formula I and Zmol of units of formula II so that the equations III and IV may be satisfied and 0.1W100pts.wt. flame retardant (E) [e.g., tris(2- chloroethyl) phosphate], and the mixture is reacted at 10W50°C.