摘要 |
<p>The invention relates to the use of special phthalocyanines carrying substituents bound by methylene groups on the skeletal structure thereof, as marking substances for liquids, especially mineral oils and liquids, and especially mineral oils containing at least one such phthalocyanine as a marking substance. The invention also relates to novel special phthalocyanines carrying substituents bound by methylene groups on the skeletal structure thereof.</p> |