摘要 |
<p>A composite, lightweight, fire-retardant laminar structural panel element (10, 10", 10", 30) which includes: (i) a sheet-like central honeycomb core (11) formed of aluminum, paper treated to improve its fire resistance characteristics, or the like; (ii) upper and lower imperforate face sheets (15, 16) formed of lightweight fibrous materials impregnated with a phenolic resin; (iii) a pair of upper and lower phenolic adhesive films (18, 19) interposed between the honeycomb core (11) and respective ones of the imperforate face sheets (15, 16) for adhesively bonding the face sheets (15, 16) to opposite sides of the core (11); and (iv), a fire-retardant coating (20) comprising a copolymer of vinylidene fluoride and hexafluoropropene applied to at least the exposed surface of the lower face sheet (16). </p> |