POLYMETHINE DYES SUITABLE FOR OPTICAL RECORDING MEDIA

摘要

Polymethine dyes suitable for use in optical recording medium, which are soluble in alcohol and have a nucleus of the general formula: in which: n is 0 or an integer, R<1> and R<2> independently represent alkyl groups of up to 30 carbon atoms with the proviso that either at least one of R<1> and R<2> contains more than 4 carbon atoms or R<1> and R<2> together represent the necessary atoms to complete a cyclic structure including the nitrogen atom to which they are attached, each Y is the same and represents a hydrogen atom, an alkoxy group of up to 12 carbon atoms or a dialkylamino group which is different to the group, and X<(-)> represents an anion. d