GB1445757A - Electrorecording sheet - Google Patents

Abstract

1445757 Electrorecording sheet MATSUSHITA ELECTRIC INDUSTRIAL CO Ltd 27 Nov 1973 [30 Nov 1972 20 March 1973] 54946/73 Heading D2B An electrorecording sheet comprises a heatsensitive component capable of forming or changing colour upon application of heat thereto, an electrically conductive component including cuprous iodide, and a support for said components, the arrangement being such that a mark is formed by the action of the heat generated on the passage of an electric current on the heat-sensitive component. The heat-sensitive component may comprise (a) a leuco dye and colour developer; (b) an organic spot reagent and an organic metal salt, or (c) a redox dye. The resistance of cuprous iodide may be lowered by addition of a resistance lowering agent. The latter may be free iodine, an iodine compound, a peroxide, an oxyacid salt, a peroxy compound, or permanganic compound. The suport may be paper, a fabric, glass or a plastics material. The sheet may comprise a support coated with a single layer containing both the heat-sensitive component and the electrically conductive component, (Fig. 3 not shown); or two layers, the layer adjacent the support comprising the electrically conductive component and the topmost layer comprising the heat-sensitive component, (Fig. 1 not shown). In modifications, an additional conductive layer e.g. of vapour deposited aluminium may be provided between the support and the layer containing cuprous iodide, (Fig. 4, not shown); or a conductive layer of carbon may be located between the support and an upper layer containing both cuprous iodide and the heat-sensitive component, (Fig. 5 not shown); or the support may be a carbonimpregnated paper, or a paper containing another electrically conductive material, (Figs. 6, 7, not shown); or the sheet may comprise a paper impregnated with both the heat-sensitive and electrically conductive component containing cuprous iodide, (Fig. 8, not shown).