Chemie Linz Aktiengesellschaft

Lenzing Aktiengesellschaft

Karlheinz Wegleitner

Gerald Saischek

Gerhard Stern

Werner Korsatko

Brigitta Korsatko-Wabnegg

Ferdinand Heu

Roman Wohlmuth

Richard Willim

Wilfried Krulla

Delayed-release tablets are formed by incorporating hemicellulose and a matrix-forming adjuvant which does not disintegrate in a pharmaceutical dosage form containing the active substance or substances, preferably as a coated tablet or dragee.

Delayed-release pharmaceutical preparation

Pure cyanuric acid is prepared from crude or waste melamine by introducing the melamine into 70 to 80% strength sulfuric acid at room temperature and heating the reaction mixture to 150.degree. to 190.degree. C., the water introduced with the sulfuric acid being distilled off during the heating period.

Process for preparing pure cyanuric acid

Novel spirocyclic boron compounds of the formula ##STR1## in which R.sub.1 and R.sub.2 are various halogen containing organic :radicals and Z.sup.+ is a hydrogen ion, an equivalent of an alkaline-earth metal ion, a guanidinium ion or alkylammonium ion as flame retarding agents in various plastics, such as polyurethanes, epoxide resins and polyesters.

Spirocyclic boron compounds, a process for their manufacture and their

Foamed plastics with improved combustion characteristics are produced by condensing an aqueous solution of formaldehyde-urea and/or melamine precondensates with polyisocyanates and optionally a polyol in the presence of an acid catalyst, being present in an amount of 1 part by weight per at least 20 parts by weight of precondensate, whereby this catalyst is added to the isocyanate before mixing with the precondensate or to the mixture of isocyanate and precondensate, but separately from the precondensate.

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Linz, Austria

Karlheinz Wegleitner