GB1024658A - Improvements in laminated sheet material - Google Patents

Abstract

1,024,658. Roof structures. RUBEROID CO. Aug. 12, 1963 [Jan. 21, 1963], No. 31802/ 63. Heading E1V. [Also in Division B5] A waterproof, non-inflammable, flexible sheet material suitable for applying to existing roof decks or to a rigid base to form panels comprises a substantially opaque, 1-4 inches thick, film of polyvinyl fluoride bonded by means of a thermosetting elastomeric adhesive to a backing layer of asbestos felt impregnated with 15-25% by weight of a non-inflammable elastomeric binder such as polychloroprene or a mixture of polychloroprene with acrylonitrile in the ratio 1:1 to 1:3. The film is rendered substantially opaque by the inclusion of up to 25% of opacifying pigments such as titanium dioxide and carbon black. Suitable adhesives, which may contain up to 10% of carbon black, include acrylonitriles with phenolic tackifiers and an isocyanate curing agent, or polysulphides. In an embodiment (Fig. 3, not shown), a wood or concrete roof deck is covered, by means of asphalt 18, with lengths 19-22 of conventional coated, sanded and asphalt-saturated base sheet, the overlapping portions being nailed to the deck. Lengths of the sheet material as above are then applied, film uppermost, to the base sheet by hot asphalt or cold cement adhesives. Side and end overlapping of the latter sheets may be achieved by providing a film-free edge 16 on each length, such edges being coated with adhesive to within one inch of the edge of the film. Alternatively, the lengths may simply abut each other. The seams are then sealed by using pressure-sensitive polyvinyl fluoride tape or by caulking. In a further embodiment, rigid panels are produced by applying the sheet material, e.g. by means of asphalt, to a rigid insulating base such, as wood, including bonded shredded wood, shavings or paper, or slabs of vermiculite, stones or gravel bonded with cement, with or without the addition of other light aggregates,