Naphthalocyanines

A naphthalocyanine compound of formula I ##STR4## where the variables have the following meanings:

• R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are each independently of the others, hydrogen, hydroxyl, C.sub.1 -C.sub.20 -alkyl or C.sub.1 -C.sub.2 0 -alkoxy, whose carbon chains may each be interrupted by from 1 to 4 oxygen atoms in ether function and which may be phenylsubstituted,
• R.sup.9, R.sup.10, R.sup.11 and R.sup.12 are each independently of the others, hydrogen, halogen or C.sub.1 -C.sub.20 -alkyl or C.sub.1 -C.sub.20 -alkoxy, whose carbon chains may be interrupted by from 1 to 4 oxygen atoms in ether function, wherein at least two of R.sub.1 -R.sub.12 are solubilizing groups,
• Me is two hydrogen atoms, two univalent metal atoms or a bivalent metal atom with or without further substituents for valence saturation,
• wherein said naphthalocyanine compound is in the form of isometric particles having a particle size distribution from 10 to 300 nm.