Improvements in and relating to laminated sheeting

908,873. Laminates. BRITISH CELANESE Ltd. May 25, 1960 [May 26, 1959], No. 17856/59. Class 140. [Also in Group XV] Sheet material comprises a layer of crumbs of thermoplastic material, a sheet of thermoplastic material in contact therewith containing particulate light-reflective material, and a transparent thermoplastic sheet in contact either with the layer of crumbs or with the sheet containing the light-reflective material, the assembly being bonded together by the application of heat and pressure. The sheets and crumbs may all be of secondary cellulose acetate (i.e. partially hydrolysed cellulose acetate soluble in acetone), or one or both of the sheets may be of cellulose triacetate, or the thermoplastic material may be polystyrene. The crumbs may be colourless or coloured, and may pass through a 10-mesh but not through an 18-mesh sieve. The transparent sheet may be colourless or coloured, and the particulate light-reflective material may be pearl essence or metal powder. The sheet of thermoplastic material may be treated with a softening agent before application of the crumbs. In pressing, a resilient sheet may be placed between the light-reflective sheet and the press, and may be a thermoplastic sheet which may be coloured and which becomes bonded to the assembly or may be bonded to the lightreflective sheet before pressing of the assembly. Alternatively, it may be separated from the light-reflective sheet by a film of non-adhesive materiel, e.g. polythene or regenerated cellulose. The layer of crumbs may be applied to the non- adhesive film, and the light-reflective film and the transparent film applied thereover with applications of solvent or softening agent to assist bonding. In Example 1, a film of secondary cellulose acetate containing diethyl phthalate and pearl essence is bonded by heat and pressure to a transparent secondary cellulose acetate sheet containing dimethyl phthalate and triphenyl phosphate. The pearl side of the laminate is coated with a mixture of diacetone alcohol, the monomethyl ether of ethylene glycol, and dimethyl phthalate, colourless crumbs of plasticized cellulose acetate are applied thereto, a transparent coloured cellulose acetate film is applied thereover, and the assembly is bonded together at 70‹ C. under pressure. The first two sheets may be placed separately in the assembly and bonded in the final operation. In Example 2, the coloured and transparent films are transposed, and the crumbs separated from the latter