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:
Mar. 17, 2026
Filed:
Jul. 12, 2022
Evonik Operations Gmbh, Essen, DE;
Berend-Jan De Gans, Muelheim an der Ruhr, DE;
Philippe Favresse, Ratingen, DE;
Wilfried Knott, Essen, DE;
Horst Dudzik, Essen, DE;
Monika Johannes, Essen, DE;
Evonik Operations GmbH, Essen, DE;
Abstract
A process can be used for increasing the molecular weight of low molecular weight α,ω-polysiloxanediols. The process involves heating the low molecular weight α,ω-polysiloxanediols in the presence of acetic anhydride at temperatures of 80° C. to 220° C., preferably at temperatures of 100 to 200° C., and particularly preferably at temperatures of 120-180° C., for 1 h to 24 h, preferably for 2 h to 16 h, and particularly preferably for 3 h to 12 h. The molar amount of the silanol groups used is greater than that of the acetic anhydride used.