GB652859A - Coloured mirrors - Google Patents

Abstract

652,859. Modifying surface reflection. LIBBEY-OWENS-FORD GLASS CO. July 29, 1946, No. 22544. Convention date, Feb. 11. [Class 97 (i)] A reflector which gives a coloured light by reflection comprises a support bearing an opaque non-reflecting or non-specularly reflecting layer and a plurality of superimposed semi-transparent layers which produce colour by optical interference. These layers may be applied to glass, furniture or plastic. In Fig. 8 a glass support 1 is shown carrying interference layers 6, 7, an opaque diffuse-reflecting layer 3, such as paint, and a lacquer protective layer 4. Layer 6 may be of copper, magnesium fluoride, aluminium or silica and the layer 7 respectively of magnesium fluoride, copper, silica and aluminium. Alternatively the opaque reflective film may be on one side of the glass, the other side carrying superimposed layers of lead sulphide and silica. Fig. 11 shows a glass support 1 bearing layers 19, 20, 21 of the same substance, e.g. copper, and layers 22-24 of a different substance, e.g. silica. Such a coating may be formed on the surface of a tumbler by thermal deposition while the tumbler is rotating, the inside of the tumbler being later coated with opaque paint. Other suitable coatings include lead sulphide, pyrite, stibnite, molybdenite, gold, silver, platinum, iron cobalt or chromium ; oxides of lead, magnesium, silver, aluminium, arsenic, tin, titanium or iron ; sulphides of zinc and copper lead selenide ; fluorides of lithium and lead chlorides of silver sodium and lead. Plastics such as polymethacrylate resins may also be used. The Specification also describes the deposit of two interference films on a polished glass support. Specifications 624,846, 632,570, 652,851 and 652,858 are referred to. The Specification as open to inspection under Sect. 91 describes also a glass support coated with a single layer of lead sulphide, as described in Specification 624,846, and gives spectral curves for the mirrors described in that Specification and in Specification 632,570. This subject-matter does not appear in the Specification as accepted.