PURPOSE: To provide a halogen-free flame-reterdant and fire-resistant sealing material by incorporating a polyfunctional isocyanate, a hydrated metal oxide, powdered melamine, a phosphorus compound, liquid silicone and powdered silica in a base material including liquid polyisoprene with terminal functionality.

CONSTITUTION: A sealing material is obtained by mixing 100 - 160pts.wt. base polymer comprising at least one component selected from liquid polyisoprene with terminal functionality (e.g. polyisoprene containing terminal hydroxyl group), liquid polybutadiene with terminal functionality and polyol, 40 - 120pts. wt. polyfunctional isocyanate, 100 - 300pts.wt. hydrated metal oxide (e.g. magnesium hydroxide), 5 - 100pts.wt. powdered melamine, 5 - 100pts.wt. phosphorus compound (e.g. aluminum metaphosphate), 5 - 50pts.wt. liquid silicone and 2 - 50pts.wt. powdered silica. The sealing material thus obtained is a carbonized one and nondripping, having excellent flame retardance, fire resistance, weather resistance, adhesiveness, etc.