摘要 |
1. A tracer (marking agent) containing a) at least 1 per cent by weight of iron powder and:or powder of a ferromagnetic alloy and at least tow of the following groups of substances : b) fluorrescent pigments ; c) organic solvent-soluble, water-insoluble fluorescent materials ; d) colorant pigments ; e) sparingly soluble and heat-stable oxides and/or salts of rare metals ; f) oxides and/or sparingly soluble salts of rare-earth metals ; in microanalytically well detectable amounts in the form of a homogeneous mixture with a thermoplastic material, characterized in that the thermoplastically processable material is the uncured polymer component of powder varnishes based on polyacrylates, polyesters, or polymeric epoxides. |