| 摘要 |
1471446 Colour former solution CIBAGEIGY AG 22 April 1975 [25 April 1974] 18200/74 Heading C4A [Also in Division D2] A colour former solution comprises a weakly volatile high boiling organic solvent having a boiling point of at least 150‹ C., having dissolved therein a colour former and a colour former de-activating substance, the colour former being an azo compound having the general Formula I in which R 1 , R 2 and R 3 each represents hydrogen, halogen, alkyl, alkoxy, aryloxy, alkoxycarbonyl, dialkylaminocarbonyl, acylamino, acyl-(alkyl)-amino, -SO 2 -NY 1 Y 2 , in which Y 1 and Y 2 each represents alkyl or aryl, or in which Y 1 and Y 2 together represent an alkylene group; X 1 is hydrogen or an alkyl group, X 2 is an alkyl, cyanoalkyl or arylmethylene group or X 1 and X 2 together represent an alkylene group, X 3 is an alkyl or aryl group and n is 1 or 2, or the general Formula II in which Z 1 , Z 2 and Z 3 each represents hydrogen, alkyl, substituted alkyl, alkoxy, halogen, nitro, acylamino, aminoacyl or alkoxycarbonyl, A 1 and A 2 each represents alkyl or phenyl or A 1 and A 2 together with the nitrogen atom to which they are bound form a heterocyclic ring system and n is 1 or 2. The de-activating substance may be a liquid organic base, e.g. triethanolamine or diethanolamine. The preferred colour formers are azo compounds. An image producing system comprises a carrier material impregnated with the colour former solution and a substrate which has incorporated therein or possesses at least one surface which is at least partially coated with a colour former activating substance or system and a re-activating substance which counteracts the de-activating substance. The carrier material may be fabric, paper or a felt or fabric pad. The re-activating substance may be an organic acid. The substrate may be a neutral or alkaline sized paper. |
