| 摘要 |
<p>Solvents for colour former combinations comprising crystal violet lactone and a complementary chromogen such as benzoyl leuco methylene blue, useful in pressure-sensitive mark-recording systems, are liquids comprising blends of an aromatic hydrocarbon component and an ester component, the weight ratio of the two components in the blend being from 85:15 to 10:90, the aromatic hydrocarbon component being a hydrocarbon in which at least half the carbon atoms are benzenoid or a mixture of such hydrocarbons, and the ester component being a diester of the formula… ROOC(CnH2n)COOR<1> or R<2>COO(CnH2n)OOCR<3>… wherein n is an integer, for example from 1 to 20, R is an aliphatic or cycloaliphatic hydrocarbon group, R<1> is an aliphatic or cycloaliphatic hydrocarbon group or a benzyl or alkylbenzyl group, and each of R<2> and R<3> is an aliphatic hydrocarbon group, or a mixture of such diesters, and the solvent having a volatility and viscosity such that it is suitable as a solvent for the chromogen in a pressure-sensitive mark-recording system.</p> |
