HEAT-SENSITIVE STENCIL SHEET

1312270 Heat-sensitive stencils RICOH KK 6 Nov 1970 [14 Nov 1969] 52937/70 Heading G2C A heat-sensitive stencil comprises a porous paper support and a layer comprising a thermoplastic resin bonded to the support with an adhesive; either the adhesive or a coating on the unbonded surface of the resin layer containing a compound or components which produce a colour on heating and a metal salt of a fatty acid with 10-22 carbon atoms as heat-fusible material which improves the clarity of the image formed. When the stencil is image-wise exposed, the resin layer fuses and perforates and a coloured image is formed in the perforated areas thus allowing the correct exposure to be more easily determined. The preferred thermoplastic resin is a vinylidene chloride/vinyl chloride copolymer while the preferred heat-sensitve compound or components are those specified in Specification 1299194. Specified adhesive are polyvinylacetate, vinylidene chloride/acrylonitrile copolymer and acrylic resins.