Hoechst Aktiengesellschaft

Gunther Nowy

Gerhard Pfahler

Hartmut Wiezer

Harald Haberlein

Georg Schmailzl

Norbert Mayer

Otto Mauz

Josef Wiedemann

Novel polymeric polyalkyl-1-oxa-diazaspirodecanes of the formula I ##STR1## are very effective stabilizers for natural any synthetic polymers. They have very low volatility, high migration resistance and high thermal stability.

Polymeric polyalkyl-1-oxa-diazaspirodecanes

By dividing the known condensation of acetoacetic acid diol esters with phenols into two process steps, a reduction in the cost of the entire process can be achieved. Methyl acetoacetate is first condensed with a phenol and the methyl 3,3-bis(4-hydroxyalkylphenyl)butanoate formed is reacted with the desired diol in the presence of a transesterification catalyst. In this way only one acetoacetic ester is necessary for various final products. The final products are useful stabilizers for plastics, in particular polyolefins.

Process for the preparation a bis(3,3-bis(4-hydroxyalkylphenyl)butanoic

In the synthesis of 2,2,6,6-tetramethylpiperidone-4 (triacetone-amine) from acetone and ammonia, a partially halogenated or perhalogenated aliphatic or cyclic hydrocarbon is used as catalyst in an amount of from 0.01 to 5 mol %, relative to acetone.

Process for the preparation of 2,2,6,6-tetramethylpiperidone-4

The invention provides derivatives of polyalkyl-1-oxa-diaza-spirodecanes prepared from compounds of the formula ##STR1## in which X is ##STR2## and mono- or dihalo-hydrocarbons by alkylation at the nitrogen atom of the 5-membered ring, and the salts thereof. The novel compounds are migration-resistant light stabilizers of low volatility for synthetic polymers.

Alkylated diaza-spirodecanes

When replacing the low molecular mercaptan used as a catalyst in the known process for preparing condensation products of phenols and acetoacetic acid esters by an n-alkyl mercaptan having of from 8 to 20 carbon atoms, the yield is improved and the reaction time reduced, while the working up of the reaction batch is simultaneously improved.

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Aystetten, Germany

Gunther Nowy