摘要 |
<p>A donor material for carbonless copying by contact with an acceptor material under applied pressure includes a sheet of paper or the like, and a coating on one face of the sheet. The coating consists essentially of a dye precursor, a wax solid at 20 DEG C. and capable of dissolving the precursor, and a liquid activator soluble in the molten wax, but at most sparingly soluble in the solid wax and incapable of dissolving the dye precursor, the wax and activator being chemically inert to the dye precursor.</p> |