| abstract |
The present invention relates to a process for the preparation of 4-hydroxy-2,2,6,6-tetramethylpiperidine by heterogeneous catalytic hydrogenation of 4-oxo-2,2,6,6-tetramethylpiperidine in a melt or solution at temperatures of 60 DEG C. to 200 DEG C. and hydrogen pressures of 10 to 300 bar, in the presence of a catalyst comprising from 20 to 68% by weight of copper, from 0 to 40% by weight of chromium, from 0 to 60% by weight of zinc, from 0 to 5% by weight of manganese, from 0 to 12% by weight of barium, from 0 to 15% by weight of silicon, and from 0 to 10% by weight of nickel, in each case based on the oxidic catalyst mass, and in which the catalyst is activated by hydrogen or a hydrogen-containing gas mixture, and separating the 4-hydroxy-2,2,6,6-tetramethylpiperidine from the catalyst. |