Erasable diazotype second originals on a translucent base have become very popular because they permit correcting, deletions and additions of new information to drawings without the need to redo an entire drawing. A new barrier film composition that acts simultaneously as matrix for the diazotype coating components and controls the ease of mechanical erasure is disclosed. The second originals exhibit almost film like reprographic continuity.
Erasable coatings for xerography paper comprise a pigment such as calcium carbonate in a binder such as an aqueous emulsion of an acrylic polymer. The erasability of the coating is improved by replacing at least 15 wt % of the binder with a polyalkane or (preferably) polyalkene wax, such as an aqueous emulsion of a polyolefin.
