Intumescent coating composition and articles coated therewith

Claim 1

AN INTUMESCENT COATING COMPOSITION COMPRISING A 40 TO 60 PERCENT AQUEOUS DISPERSION OF A MIXTURE CONSISTING OF 70 TO 85 PERCENT OF NON-FILM FORMING INTUMESCENT SOLIDS AND ENOUGH OF AN AQUEOUS FILM FORMING LATEX OF POLYSTYRENE TO PROVIDE CORRESPONDINGLY FROM 30 TO 15 PERCENT OF THE POLYMER SOLIDS, BASED ON THE TOTAL WEIGHT OF SOLIDS PRESENT; SAID INTUMESCENT SOLIDS CONSISTING ESSENTIALLY OF (1) A FOAM FORMING INGREDIENT SELECTED FROM THE GROUP CONSISTING OF MONOAMMONIUM PHOSPHATE, DIAMMONIUM PHOSPHATE, PHOSPHORIC ACID, AMMONIUM SULFATE, SULFAMIC ACID, AMMONIUM SULFAMATE, AMMONIUM BROMIDE, SODIUM TUNGSTATE, AND SODIUM BORATE; (2) FROM 10 TO 70 PERCENT, BASED ON THE WEIGHT OF THE FOAM FORMING INGREDIENT, OF AT LEAST ONE POLYHYDRIC COMPOUND FROM THE CLASS CONSISTING OF STARCH, THE HEXITOLS, THE PENTITOLS, AND THE MONO-, AND DI-TETRITOLS, THE AMOUNT OF ANY STARCH EMPLOYED BEING LESS THAN 15 PERCENT OF THE WEIGHT OF SAID FOAM FORMING INGREDIENT; AND (3) NOT MORE THAN 55 PERCENT, BASED ON THE WEIGHT OF THE FOAM FORMING INGREDIENT, OF AN AMINO COMPOUND FROM THE GROUP CONSISTING OF GLYCINE, UREA, DIMETHYL UREA, GUANYL UREA, GUANIDINE, AND DICYANDIAMIDE.