Basf Aktiengesellschaft

Heidi Benthack-Thoms

Peter Neumann

Matthias Dust

Helmut Barzynski

Harald Kuppelmaier

Klaus-Dieter Schomann

Ernst Schefczik

Eberhard Koester

Gerhard Wagenblast

Bernhard Albert

Klaus D Schomann

Wolfgang Schrott

Michael Acker

Peter Hauser

Harald Kupplemaier

Naphtholactamtrimethine dyes useful in optical recording media have the formula ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different and each is independently of the others C.sub.1 -C.sub.22 -alkyl, which may be substituted and/or interrupted by one or more oxygen atoms, one or more imino groups or one or more C.sub.1 -C.sub.4 -alkylimino groups, or is substituted or unsubstituted C.sub.5 -C.sub.7 -cycloalkyl or substituted or unsubstituted phenyl, and the rings A, B, C and D may each be substituted and/or benzofused.

Naphtholactamtrimethine dyes and optical recording medium containing same

Naphtholactam dyes of the formula ##STR1## where R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, n, p, Z.sup.1, Z.sup.2 and the rings A, B, C and D each have the meanings stated in the description, and an optical recording medium which contains one or more naphtholactam dyes and may contain a base.

Naphtholactam dyes and optical recording medium containing these dyes

An optical recording medium composed of a base material and a laser light sensitive layer which contains an azulenium dye as storage material with or without a binder is obtainable by spin-coating a solution containing an azulenium dye of the formula ##STR1## where R is C.sub.1 -C.sub.6 -alkyl which may be substituted or unsubstituted, and n is 1, 2 or 3, with or without a binder and one or more solvents which have evaporation numbers of not less than 4 and in which an azulenium dye of the abovementioned formula has a solubility of not less than 5 g/l onto a transparent base material based on a plastics material or glass.

Optical recording medium containing an azulenium dye

Naphtholactam dyes and optical recording medium containing these days

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.

Naphtholactamsquaric acid dyes and optical recording materials

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