Described is a flexible, solid fire sealant produced by high shear mixing
in a substantially volatile-free state and capable of being molded or
extruded into a variety of shapes and used as firestops for windows,
doors, dampers, shutters, and through-penetrations, the sealant containing
water-insoluble intumescent mineral granules, a polymeric, halogen-free
binder, and a flame retardant, wherein the sealant has a softness value
from about 0.01 to about 3.75 mm and exhibits high expansion values and
chars upon exposure to heat.
