abstract |
Disclosed is a method for producing 4-hydroxy-1,2,2,6,6-pentamethylpiperidine (PMP) from 4-hydroxy-2,2,6,6-tetramethylpiperidine (TMP) and formaldehyde (Fd) with methanol to be used as an intermediate for the preparation of light stabilizers of the HALS type, and apparatus for carrying out this method. |