| 摘要 |
<p>PCT No. PCT/CH80/00039 Sec. 371 Date Feb. 12, 1981 Sec. 102(e) Date Feb. 12, 1981 PCT Filed Mar. 21, 1980 PCT Pub. No. WO81/00084 PCT Pub. Date Jan. 22, 1981.A mixture of two to three ingredients, which ingredients may be stored on their own, are used for the manufacture of a thermochrome lacquer. The first ingredient is a compound of heavy metal or noble metal dispersed in a resin base solution, the second ingredient is a sulfur/carbon-covalent compound dispersed in the resin base solution, or in a hardener for the resin base, and the third ingredient, if required, is the hardener. The resin base is related to the hardener, and the metal compound to the sulfur/carbon covalent compound in respective stochiometric ratios. The metal compound is a metal compound of an oxide forming metal sulfide compounds with the sulfide ions, the metal sulfide compounds being irreversibly darkened, or a metal compound of an inorganic anion, or a metal compound of a monocarboxylic acid, or a metal compound of a dicarboxylic acid. The resin base consists of a prepolymerizate of a methacrylic acid, or of a glycide lather, and the hardener consists of a diol or an amine. The thermochrome layer has a thickness of 10 to 100 mu m, and experiences a irreversibly local darkening by a heated heating element. The layers from the lacquer are used on card-shaped payment means having optical markings, which are thermally erasable, and whose erasure is indicated by blackening.</p> |
