| 摘要 |
1471445 Ink containing colour former CIBAGEIGY AG 22 April 1975 [25 April 1974] 18199/74 Heading C4A [Also in Division D2] An ink comprises an ink vehicle having a pH of about 7, a colour former and sufficient liquid organic base to ensure that no reaction occurs between the colour former and substrate on which the ink is to be printed. Suitable organic bases are amines and alkanolamines. An inert plasticizer which is a solvent for the colour former may be present. The colour former may be an azo compound, or a lactone, a spiropyran or related, a leuco or a metal complex forming colour former. Suitable vehicles are nitrocellulose, zinc resinate, a polyamide resin, a vinyl, acrylic or alkyd resin, ethyl cellulose, a stand oil or a resin modified stand oil. A pigment may also be present. An image-producing system comprises a substrate having the ink printed on at least a portion of a surface thereof and a carrier material impregnated with a solution of an organic acid in a weakly volatile high boiling solvent having a boiling point of at least 150‹ C. The substrate may be paper which has been formed using a neutral or alkaline size. The carrier material may be a fabric, a paper or a felt or fabric pad. |
