Ciba-geigy Corporation

Ciba Specialty Chemicals Corporation

Udo Quotschalla

Helmut Linhart

Jean-Roch Pauquet

Ronald Salathe

Described are compositions comprising (a) 25 to 99% of organic phosphite or phosphonite, based on the total weight of the composition, (b) an effective stabilizing amount of organic amine, and (c) an effective stabilizing amount of acid-binding metal salt, wherein said composition comprises no organic polymers or alkali metal phosphates as further components, as well as a process for stabilising organic phosphites or phosphonites against hydrolysis by addition of organic amine and acid-binding metal salt. The compositions are distinguished by their excellent stability to hydrolysis and have good storage stability even at high atmospheric humidity. The novel compositions and process products can be used with advantage as stabilisers for organic material against the harmful action of heat, oxygen and/or light.

Enhancement of the storage stability of organic phosphites and

The invention relates to a process for stabilizing an organic phosphite or phosphonite or a mixture of organic phosphites or phosphonites against hydrolysis, which comprises adding, as the stabilizer, a compound from the class of sterically hindered amines, so that the stabilized phosphite or phosphonite contains 0.1 to 25% by weight of the amine compound (relative to the phosphite or phosphonite). Compositions comprising organic phosphite or phosphonite and sterically hindered amines are notable for excellent hydrolytic stability and have a long shelf life even at high atmospheric humidity. The products of the process according to the invention are very useful as stabilizers for organic material, in particular organic polymers, for example synthetic polymers, against the damaging influence of heat, oxygen and/or light.

Enhancing the storage stability of organic phosphites and phosphonites

The invention relates to a process for stabilizing a crystalline organic phosphite or phosphonite against hydrolysis, which comprises introducing a mixture comprising phosphite or phosphonite, a solvent or solvent mixture, and 0.1 to 100% by weight (relative to phosphite or phosphonite) of an amine and having a temperature of 50.degree.-100.degree. C. as a homogeneous melt into a liquid crystallization medium whose temperature during the addition is maintained 10.degree.-70.degree. C. below the temperature of the melt. The phosphites or phosphonites stabilized according to the invention are distinguished by their excellent resistance to hydrolysis and have a long shelf life even at high atmospheric humidity. They can be advantageously used as stabilizers for organic material against the damaging effect of heat, oxygen, and/or light.

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Heppenheim, Germany

Udo Quotschalla