Abstract: A description is given of the use of naphthalene-1,8-dicarboxylic monoimides of the formula (I), in which R1 is hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkenyl, heterocycloalkyl, aryl or heteroaryl and R2 is a radical containing at least one ? electron system containing a carbon atom and at least one further atom selected from carbon, oxygen, and nitrogen, with the proviso that the radical contains at least one atom other than carbon; to protect organic material from the damaging effects of light, of compositions which comprise at least one naphthalene-1,8-dicarboxylic monoimide of the formula (I) in an amount which provides protection from the damaging effects of light, and at least one organic material, and of new naphthalene-1,8-dicarboxylic monoimides (I).

Abstract: A process for the selective hydrogenation of butadiene to butenes in the liquid phase or trickle phase in contact with a fixed-bed supported noble metal catalyst, wherein a high-butadiene C.sub.4 stream having a butadiene content of from 20 to 80% w/w, based on the weight of the C.sub.4 stream, is hydrogenated in a cascade of two reaction zones such that the hydrogenation product from the first reaction zone has a butadiene content of from 0.1 to 20% w/w and the hydrogenation product from the second reaction zone has a butadiene content of from 0.005 to 1% w/w, based in both cases on the weight of the C.sub.4 stream, provided that the butadiene content of the hydrogenation product from the second reaction zone is at least 5 times smaller than that of the hydrogenation product from the first reaction zone.