| abstract |
Methine dyes of the formula in the R¹, R², R³, R⁴, X, Y and the rings A and B each have the meaning given in the description, and methine dyes, obtainable by reacting an organic mono- or polyisocyanate with such methine dyes of the above formula in which only the radicals R¹ and / or R⁴ have a group reacting with an organic mono- or polyisocyanate, and an optical recording medium containing one or more of the new dyes. |