The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 14, 1997
Filed:
Feb. 16, 1995
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
The invention relates to a process for the preparation of polyalkyl-1-oxa-diazaspirodecane compounds, which can be used as highly active light stabilizers for polymers. The reaction is carried out in a solvent mixture of at least one alcohol and if appropriate an inert organic solvent in the presence of solid alkali metal hydroxide or a corresponding amount of a mixture of solid alkali metal hydroxide and water as the sole catalyst. The process offers the advantage that, by using a solvent mixture and dispensing with a phase transfer catalyst, a higher rate of reaction and therefore higher product quality with the same yield are achieved. By dispensing with a phase transfer catalyst, which remains in the waste water and must be disposed of expensively, and by the reusability of the solvent mixture, the process is more environment-friendly and more economical than processes known to date.