Hoechst Aktiengesellschaft

Siegfried Jung

Horst Staendeke

Winfried Ehrl

Hans-Joachim Semmler

Bernd Hoffmann

The invention relates to a halogen-free, flame retardant rigid polyurethane foam based on polyether-polyols and polyisocyanates, which comprises, as the polyol component, mixtures of nitrogen-free and nitrogen-containing polyether-polyols and, as the flameproofing agent, ammonium polyphosphate.

Halogen-free, flame retardant rigid polyurethane foam

Fluorine-containing alkylsulfobetaines of the general formula ##STR1## wherein R.sub.f denotes a perfluoroalkyl radical having 3 to 16 C atoms, R.sub.1 and R.sub.2, which can be identical or different, denote alkyl radicals or hydroxyalkyl radicals having 1 to 4 C atoms, a is zero or 1, b assumes the value 1 when a is equal to 1 and the values 1 to 4 when a is equal to 0, and c is 3 or 4, are described. These are prepared by reacting the corresponding fluorine-containing amines with propanesultone or butanesultone in organic solvents. The compounds are distinguished in particular by high interfacial activity at the interface of water with non-miscible organic liquids and by compatibility with other surfactants. They are suitable for use as aftertreatment agents (auxiliary dispersing agents) in dispersions of fluoropolymers and as components in fire-extinguishing agents.

Fluorine-containing alkylsulfobetaines, a process for their preparation

Film-forming fire extinguishing foam concentrates are described containing water, at least one hydrocarbon surfactant and at least one fluorosurfactant compatible with the latter one, which comprise a small amount of aliphatic carboxylic acids of the formula C.sub.n H.sub.2n+1 COOH, in which n is an integer of from 7 to 9, or the salts thereof.

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Karben, Germany

Siegfried Jung