| 摘要 |
In one embodiment, this invention relates to a bitumen-based built-up roofing system comprising a structural deck covered with a membrane comprising; (A) at least two plied layers of reinforcement, the bottom layer being attached to said structural deck, (B) a separately applied bitumen-based waterproofing adhesive between each layer wherein each ply is firmly adhered to the bitumen-based adhesive applied between the plies, (C) a bitumen based flood coat over the plied layers, and (D) a protective layer of inert mineral aggregate material embedded in the flood coat, wherein the bitumen in at least the flood coat comprises a coal tar composition prepared from a blend comprising: (1) from about 80 parts to about 98 parts by weight of coal tar having an overall float test of from about 50 seconds to about 220 seconds, (2) from about 2 parts to about 20 parts by weight of coal tar pitch having a softening point of from about 140 to about 160 DEG C., and (3) from about 1% to about 20% by weight, based on the total weight of the composition, of an acrylonitrile-butadiene copolymer. In other embodiments, the present invention relates to a coal tar impregnated reinforcement sheet; a method of re-coating a bitumen-based built-up roofing membrane; a method of re-coating a built-up roofing system having a mineral-surfaced cap sheet; and a method of re-covering a bitumen-based built-up roofing membrane.
|
