GB990978A - Thermographic method of preparing hectograph master sheets - Google Patents

Abstract

990,978. Producing hectograph duplicating masters by a thermographic transfer process. COLUMBIA RIBBON & CARBON MANUFACTURING CO. Inc. July 28, 1961, No. 27479/61. Heading G2C. A hectograph duplicating master sheet is prepared by (a) placing in intimate surface contact a foundation sheet 10 bearing images 12 containing infra-red absorbing material and the transfer layer of a hectograph transfer sheet 20,said layer being transferable on heating and comprising a surface coating 22 of thermoplastic resinous material on an un underlayer 21 containing non-infrared absorbent dyestuff, (b) subjecting the contacted sheets to infrared to cause adherence of the image areas of the foundation sheet to the transfer layer, and (c) separating the sheets to form the duplicating master sheet comprising the foundation sheet 10. The foundation sheet 10 may be of paper, polyester film, cellulose aceate or polyvinyl fluoride and may be frosted on its image bearing surface and the transfer layer surface coating resin may be of chlorinated rubber, polyisobutylene, or chlorinated polyphenyls. The foundation sheet may have directreading images on the upper surface and corresponding reverse-reading images on its lower surface to which transfer of hectograph dyestuff is effected. Thus an exhausted master sheet may be replenished by a process similar to that employed above in the production of such a sheet, the transfer layer of the transfer sheet preferably but not necessarily being free from the thermoplastic resin surface coating.