| 摘要 |
Esters and amides from 4-hydroxy-and 4-amino-polyalkylpiperidines and hydroxybenzylmalonic acids substituted at the central carbon atom with an organic residue, preferably alkyl-, esteralkyl- or phosphonoalkyl-groups, are excellent stabilizers for organic polymers, especially for polyolefins. They protect the polymers as well against light degradation as against thermo-oxidative degradation. The compounds can be prepared by hydroxybenzylation of the corresponding derivatives of substituted malonic acids. Bis-malonic acid derivatives may be obtained from the monomalonics by reaction with formaldehyde.
|
