| 摘要 |
<p>1398029 Flexible glass-plastics laminates LADCO ENTERPRISES Ltd 30 March 1973 15409/73 Heading B5N [Also in Division B8] A plastically deformable laminate which may also be folded and rolled, for use in packaging comprises a layer of thin glass flakes in close overlapping assembly bonded to at least one heat-deformable plastics carrier layer. The flakes may be joined by a binder. The flake layer may be bonded to one or more plastics layers, e.g. polyethylene, polypropylene, polystyrene or P.V.C., to form a symmetrical or asymmetrical laminate, or to a rigidifying layer of foam plastics. The binder should have a softening point and viscosity below that of any outer plastics layers and may be polyethylene or wax/polyethylene hot-melt material. The glass flakes may have a thickness below 200 Á, e.g. 3-50 Á and their transverse dimension may be greater than 3 times their thickness. The binder layer between the flakes should be less thick than the flakes. Adhesion between the flakes and the binder is facilitated by pretreating the flakes with a chlorosilane, chlorosiloxane, organic metal complex or metal oxide. If desired, an edge portion of the layer may contain no flakes. The flake layer may be made by casting and doctoring a mixture of flakes and unpolymerized binder which is subsequently polymerized, or by extruding a heated mixture of flakes and granular or particulate binder, in which case the mixture may be formed under vacuum and pressed out between cooled cylinders. The flake layer may be deposited on to an outer layer of the laminate or on to a relase surface; in one embodiment, the flake layer is formed between extruded plastics layers and the laminate is compressed between rollers. To facilitate degradation of the laminate, the plastics constituents may contain an ultraviolet light absorber and the glass flakes may be tinted.</p> |
