Patent ID: 7767597

Claim:
A fire-blocking paper adapted for incorporation into a fire-barrier film, the paper comprising inorganic bio-soluble fiber, chopped glass non-respirable fiber, organic reinforcing fiber, organic binder, and inorganic binder or filler; and, optionally refractory ceramic fiber, wherein the biosoluble fiber comprises at least one of: the fiberization product of from about 65 to about 86 weight percent silica, from about 14 to about 35 weight percent magnesia, from 0 to about 7 weight percent zirconia, and about 5 weight percent or less impurities; or the fiberization product of from about 60 to about 70 weight percent silica, from about 16 to about 35 weight percent calcia, and from about 4 to about 19 weight percent magnesia; or the fiberization product of from about 61 to about 67 weight percent silica, from about 27 to about 33 weight percent calcia, and from about 2 to about 7 weight percent magnesia.