Abstract: The subject invention relates to method for processing crude polyoxymethylene in which the isolation of unstable components from crude polyoxymethylene, such as residual monomers which are at least partly in the form of cyclic formaldehyde derivatives, is effected by treatment of the crude polyoxymethylene with an inert gaseous medium. The method of the invention is characterized in that the gaseous medium contains at least 10 volume % of water vapor, and less than 0.1 volume % of a volatile base, and/or less than 1 volume % of a volatile solvent. In an alternative variant method, the gaseous medium contains at least 10 volume % of water vapor and the treatment occurs at a temperature between 114.degree. C and the softening temperature of the crude polyoxymethylene and at a pressure of less 1.2 .multidot.10.sup.5 Pa.
Abstract: There is described an electrolytic bath for the deposition of haze-free glossy rhodium coatings which furnish a white gold-like tint and low tension flims. This bath in addition to rhodium sulfate or phosphate, sulfuric acid and/or phosphoric acid also contains a sulfonic acid, especially an aromatic sulfonic acid, as for example, phenolsulfonic acid.
Type:
Grant
Filed:
January 15, 1982
Date of Patent:
September 6, 1983
Assignee:
Dequssa Aktiengesellschaft
Inventors:
Erika Kreuter, Werner Kuhn, Wolfgang Zilske