TRYCKKENSLIGT KOPIEPAPPER, HOS VILKET SOM FERGBILDARE ANVENDES ETT BENSYLAMINOFLUORANDERIVAT

摘要

1335762 Pressure sensitive recording materials YAMAMOTO KAGAKU GOSEI KK 19 April 1971 [8 July 1970] 26232/71 Heading D2B [Also in Division C4] Compounds of formula: are used as colour formers in pressure-sensitive copying paper. In the above formula R 1 and R 2 are H, halogen or CH 3 ; R 3 is H, halogen, CH 3 or C 2 H 5 ; R 4 and R 5 are CH 3 or C 2 H 5 and n is an integer from 1-5. The pressure sensitive copying paper may be formed by applying microcapsules of a compound of formula I dissolved in a solvent of low volatility to a lower face of an upper sheet of paper and a solid acid e.g. an acid clay or phenol to an upper surface of a lower sheet of paper. Alternatively the capsules of the fluoran and a solid acid may be mixed together and coated on to the same sheet of paper, or mixed together and incorporated into paper pulp which is then formed into paper. Coloured marks are formed on the paper by application of local pressure when the capsules are ruptured and the fluoran is contacted with the acid, converting the fluoran to a coloured form.