GB1317511A - Pressure-sensitive copying material - Google Patents

Abstract

1317511 Pressure-sensitive copying system CIBA-GEIGY AG 19 April 1971 [29 Jan 1970] 20683/71 Addition to 1307382 Heading D2B The pressure-sensitive copying system of parent Specification 1,307,382 is modified in that (i) the solvent contains at least one chromogenic substance, which becomes coloured when brought into contact with atmospheric oxygen or with a colour developer, and in the latter event (ii) the system also contains a colour developer either within or on the carrier material or on the separate, additional carrier material (if present), or within or on the covering layer (if present). Example 1 describes a system comprising a first sheet of paper coated with microcapsules containing Crystal Violet lactone dissolved in tri-n-butyl phosphate and a second sheet coated with attapulgite, starch and a dyestuff of the formula When the first sheet is placed, treated side lowermost, over the second sheet, treated side uppermost, and the top side of the oversheet is written upon, a copy of the script appears in a violet-black colour on the top side of the receiving sheet. Benzoyl lenco-methylene blue may be used instead of, or together with, Crystal Violet lactone (Examples 2 and 3). Example 4 describes a system in which the oversheet is identical to that used in Example 1, but the receiving sheet is coated with a composition containing the dyestuff an acid phenolic resin, titanium dioxide, a condensation product of formaldehyde and naphthalenesulphonic acid, starch, and a butadiene latex. Example 5 describes a system comprising a single sheet of paper coated with the microcapsules of Example 1 and the coating composition applied to the second sheet referred to in that Example. When a paper sheet is placed over the treated sheet and written upon, a copy of the script in a violetblack colour is produced on the treated sheet. Example 6 relates to a system comprising a paper coated with (a) sodium alginate and an etherified methylolmelamine to improve "solvent hold out," (b) a starch-containing dispersion of a polymetaphosphate and C.I. Solvent Black 1, and (c) an aqueous dispersion of a melamine formaldehyde resin, polyvinyl alcohol, and an acid phenolic resin, and a microcapsule coated sheet as described in Example 1. Example 7 relates to a system comprising the microcapsule-coated sheet of Example 1 and a paper in which the solvent dyestuff-1- methylamino-4-(m-toluidino)-anthraquinone is incorporated in the paper, the paper being coated with an attapulgite-starch composition. The carrier materials may be films of organic polymeric materials, metal foils, or fibrous fleeces. Malachite green lactone, and its ethyl and propyl homologues may also be used as the chromogenic substance. Many suitable colour developers are named.