Concentration of light over a particular area, and novel perylene-3,4,9,10-tetracarboxylic acid diimides

Abstract

Light is concentrated in plastic sheets by a method in which the fluorescent centers used are perylenetetracarboxylic acid diimides of the formula ##STR1## The compounds (I) are prepared by chlorinating (I) in which n is 0 with sulfuryl chloride in an inert organic liquid in the presence of a catalyst. In the formula, n is 2, 3, 4 or 5 or 6, and R and R.sup.1 independently of one another are each (a) straight-chain or branched C.sub.1 -C.sub.18 -alkyl which is unsubstituted or substituted by cyano, hydroxyl, cycloalkyl, alkylcarbonyloxy, alkenylcarbonyl-oxy or cycloalkylcarbonyloxy and in which the alkyl chain may furthermore be interrupted by O or S, or (b) C.sub.5 -C.sub.18 -cycloalkyl which is unsubstituted or substituted by alkyl, carboalkoxy or trifluoromethyl. Novel perylenetetracarboxylic acid diimides of the formula I, where n is 4 and R and R.sup.1 are each 3-(2'-ethylhexyloxy)-propyl, 2-ethylhexyl, butyl, octyl, tridecyl, octadecyl, pinan-3-ylmethyl, 6-(2'-ethylhexanoyloxy)-6-methylhept-2-yl, 4-methylcyclohexyl, 3,5-dimethylcyclohexyl, 2,6-dimethylcyclohexyl, 2,6-diisopropylcyclohexyl or norbornyl, or R is C.sub.4 -C.sub.12 -alkyl, C.sub.1 -C.sub.4 -alkyl-substituted cyclohexyl or cyclohexyl-C.sub.1 - or C.sub.2 -alkyl, and R.sup.1 is 2-hydroxyethyl, C.sub.1 -C.sub.19 -alkylcarbonyloxy-C.sub.2 -C.sub.4 -alkyl, C.sub.6 -C.sub.12 -cycloalkylcarbonyloxy-C.sub.2 -C.sub.4 -alkyl or C.sub.2 -C.sub.4 -alkenylcarbonyloxy-C.sub.2 -C.sub.4 -alkyl. The dyes (I) give lightfast fluorescent colorations in plastics.

Dependencies are inferred from the claim text.