Oblon, Fisher, Spivak, McClelland & Maier
Naphtholactamsquaric acid dyes and optical recording materials containing these dyes
 Naphtholactamsquaric acid dyes of the formula ##STR1## where R.sup.1 and R.sup.2 independently of one another are each unsubstituted or substituted C.sub.3 -C.sub.22 -alkyl, in which the alkyl chain may be interrupted by oxygen atoms, or are each unsubstituted or substituted C.sub.1 -C.sub.4 -aralkyl, unsubstituted or substituted C.sub.5 -C.sub.7 -cycloalkyl or unsubsituted or substituted phenyl, and the rings A, B, C and D are unsubstituted or substituted and/or benzofused, and optical recording materials consisting of a base and a layer which is sensitive to laser light and is composed of a thermoplastic or crosslinked polymer and one or more dyes (I). Because of the high light absorption of (I), the recording materials are very sensitive to light from the GaAlAs semiconductor laser. An excellent signal-to-noise ratio is obtained on reading the recordings. 
BASF Aktiengesellschaft
C Y
C09B Y10S
inventional additional
Klaus D. Matthias Peter Harald Helmut Heidi Gerhard Peter
Schomann Dust Neumann Kuppelmaier Barzynski Benthack-Thoms Wagenblast Hauser