GB669212A - Improvements in hectograhic transfer sheets and method of making same - Google Patents

Abstract

669,212. Carbon paper &c., printing-surfaces. COLUMBIA RIBBON & CARBON MANUFACTURING CO., Inc. Nov. 7, 1949 [Nov. 9, 1948], No. 28425/49. Drawings to Specification. Classes 100 (ii) and 100 (iv). A transfer sheet includes a base of tissue paper or the like, a transfer coating, and a protective coating to prevent smudging and comprising a binder and an antifriction component of lamelliform particles dispersed in the binder. The transfer coating may have a wax base and comprise plasticising and hardening ingredients, together with a pigment (if for use as carbon paper), or a dye such as crystal violet (if for use as a hectograph transfer sheet), and may also be used, with or without a pigment, to transfer an ink-receptive image to a planographic sheet. The protective coating may be applied by a solvent such as carbon tetrachloride, trichlorethylene or naphtha which is ineffective against the transfer coating, and may comprise a resin soluble in one of such solvents, and an oleous or waxy ingredient to ameliorate the toughness of the resin. The anti-friction component may be aluminium, bronze or graphite powder, ground fish scales, or mica. An example of a protective coating is a binder comprising the substance known under the Registered Trade Mark " Tornerit " (chlorinated rubber) 1¢ parts and beeswax 2¢ parts, aluminium powder 1 part, carbon tetrachloride 70 parts. The coating is spread and allowed to set by evaporation of the solvent, and a buffing- wheel may be applied to polish the surface and make it more resistant to abrasion. If both the transfer and protective coatings are waxy, the overcoat may be applied in a semi-liquid state, or the waxy constituent of the overcoat may have a lower melting point than that of the transfer coating, to avoid co-mingling of the coatings. The protective coating may have an added layer of wax on top of the composite layer described, and is preferably applied so as to overlap the edges of the transfer coating. Printing-surfaces.-Master units may be constructed by attaching a master sheet along one edge to a hectographic transfer sheet as described. Pre-printed inscriptions may be applied to the master sheet by passing the unit through a printing machine, no slip sheet being necessary. A similar unit for preparing a directreading design on a sheet for use in offset planographic printing may be formed by attaching a transfer sheet, whose under-surface consists in part of transferable ink-retaining material, to a sheet having an upper planographic surface, and writing, typing, &c. on the uncoated surface of the transfer. If a mirror-script design is required for non-offset printing, writing, typing, &c. the inscription is effected on the under-surface of the planographic sheet.