| 摘要 |
1,011,262. Laminates. MINNESOTA MINING & MANUFACTURING CO. Dec. 29, 1961 [Dec. 29, 1960], No. 46684/61. Drawings to Specification. Heading B5N. A laminated sheet material comprises a " lossy " vibration-absorbing foam layer bonded to an overlying relatively thin planar-rigid but flexible constraining layer having a tensional stiffness value at least 10 times as great as the shear stiffness value of the foam layer, the foam layer having a bulk density factor of 0À05 to 0À5 the loss tangent value of the foam and the storage shear modulus measured at room temperature over the frequency range 100-100 c.p.s. being respectively in the range 0À3-2À5 and 10<SP>5</SP>-10<SP>9</SP> dynes/cm.<SP>2</SP> A layer of an aggresively tacky pressure-sensitive adhesive, for example polyisoctylacrylate may be applied to the free side of the foam, in order to adhere the sheet to a vibrant rigid sheet, such as an aircraft panel, to dampen the vibrations. The pressure-sensitive adhesive may be covered by a silicone-coated strippable paper liner. Suitable foams include polyurethane, polyvinyl chloride, polyisobutylene, polyethers, polyesters, silicone rubbers, fluorocarbon rubbers, butyl rubber, and polychloroprene, and may include fillers such as refined clays, zinc oxide, titanium dioxide, vermiculate, and wood flour. The constraining layer may be of aluminium foil, which may be laminated to paper by a casein-neoprene adhesive. Polyvinyl chloride and polyester film, which may be ornamentally coloured and embossed, film-paper laminates, fibre-reinforced films, or papers which are sufficiently dense, or have been resin-impregnated or sized, may also be used. |
