Process for producing paper having a coating of pressure-sensitive transfer copying material

摘要

A process is described for continuously producing paper having a coating of dyestuff donor mass for reaction with a dyestuff acceptor mass. A web of the paper passes between a printing block surrounding a roller and a donor mass transfer roller whereby the paper is partially coated on one face with the donor mass. The transfer roller receives the donor mass from a system by which the viscosity of the mass is kept constant by a viscosity measuring device controlling the supply of solvent to the donor mass. The coated paper proceeds over a cooling roller, through a drying tunnel in which it is subjected to streams of hot air, and a further cooling roller. The dyestuff donor mass is thereby dried and consolidated and the paper continues through a printing device whereby text is printed onto the paper. The process can be used in the production of a transfer copying set comprising an upper sheet bearing a text on its upper face and a dyestuff acceptor mass over the whole of its lower face, one or more intermediate sheets partially coated on top with donor mass and wholly coated beneath with acceptor mass, and a lower sheet partially coated on top with donor mass.