GB666450A - Marking fluid and methods for the physical application thereof - Google Patents

Abstract

666,450. Printing - surfaces; ink ribbons. NATIONAL CASH REGISTER CO. Oct. 13, 1949 [Nov. 16, 1948; Nov. 16, 1948; Nov. 18, 1948], Nos. 26285/49, 26286/49 and 26287/49. Drawings to Specification. Classes 100 (ii) and 100 (iv). [Also in Groups VIII and XV] Marks of different colours are produced on sheets of paper and like receiving surfaces by means of a marking liquid comprising an ink and a colour reactant substance, the sheet being in parts unsensitised and in part sensitised with a substance which reacts with the colour-reactant in the ink to produce a colour different from the ink, the marks on the unsensitised portions having thus the normal colour of the marking liquid while the marks on the sensitised portions have a colour which is a blend of the colour of the ink and that due to the colour reactions. Marking compositions specified are 3 per cent crystal violet lactone, 3 per cent Red dye Sudan III and 94 per cent chlorinated diphenyl having a 48 per cent chlorine content. The violet lactone may be replaced by malachite green lactone, Michler's Hydrol or its methyl ether or 3.3-bis(p-alkylaminophenyl) phthalides in which the alkyl group is methyl, ethyl or dipropyl. The sensitising material which is reactant with the above may be attapulgite, halloysite, magnesium trisilicate, kaolin, bentonite, zinc sulphide, calcium fluoride and zeolites in which the base exchange cations are replaced by cations of metals. In another example the fluid comprises 3 per cent of the acetate of rhodium B base, 3-8 per cent ferric ammonium sulphate and 94-89 per cent glycerine or hydrogenated methyl abietate and the surface is sensitised with tannic acid. The printing fluid may be applied from a type member having microscopic interconnecting pores or channels e.g. as described in Specifications 531,548, 550,023, 606,169, [Group IV (a)], and 608,998, by a ribbon impregnated with the fluid, or may be contained in droplets in a coating applied to a sheet placed adjacent to the underlying sheet coated with the co-reactant substance. Fig. 12 (not shown) shows a typewriter platen 14, a ribbon carrier 20 impregnated with the marking fluid and a billing form 13 having an unsensitised column 11 and a sensitised column 12, the numbers 22, 23, 24 thus appearing in a colour different to the numbers 25, 26. The Specification as open to inspection under Sect. 91, refers to o-hydroxy benzal acetophenone as a colour former. This subject-matter does not appear in the Specification as accepted.