| 摘要 |
1,235,991. Colour-reactive copying sheets. NATIONAL CASH REGISTER CO. 21 Oct., 1969 [8 Nov., 1968], No. 51533/69. Heading D2B. [Also in Division B8] Colour-transfer papers are produced by coating paper sheets with a composition comprising a binder and an encapsulated colourproducing product in the form of adherent, random clusters of two types of microcapsules of two different size ranges, the larger of which contains as core material a solvent or liquid diluent for the core-material of the smaller capsules, the latter being a chromogenic material capable of reacting chemically to produce a coloured dyestuff or a solution thereof. Preferred chromogens are crystal violet lactone and benzoyl leucomethylene blue dissolved in chlorinated biphenyl and a hydrocarbon oil of 330-500‹F distillation range. The capsule walls may be composed of gelatin/gum arabic complex (which may be hardened). |
