Polyamide compositions containing a phenol, a phosphate, a manganese salt, and an acid anhydride as stabilisers

Claim 1

SYNTHETIC POLYAMIDE COMPOSITIONS WHICH ARE SUBSTANTIALLY FREE FROM COLOUR AND OF GOOD STABILITY AGAINST DISCOLORATION BY HEAT AND LIGHT, IN WHICH HAVE BEEN INCORPORATED DURING POLYCONDENSATION (1) BETWEEN 0.02 AND 0.2% OF A THERMALLY STABLE PHENOL CONTAINING AT LEAST ONE TERTIARY-BUTYL GROUP SELECTED FROM THE CLASS CONSISTING OF 2,5-DI-TERT-BUTYL-HYDROQUINONE, 2,2''-METHYLENE-BIS-(4-METHYL-6-TERT-BUTYL-PHENOL), 2,2''-METHYLENEBIS-(4-ETHYL-6-TERT-BUTYL-PHENOL), AND 4,4''-BUTYLIDENE BIS(6-TERT-BUTYL-M-CRESOL), (2) BETWEEN 0.05 AND 0.5% OF A COMPOUND SELECTED FROM THE CLASS WHICH CONSISTS OF SALTS AND ESTERS OF INORGANIC PHOSPHORUS OXY-ACIDS, (3) BETWEEN 20 AND 80 PARTS OF MANGANESE PER MILLION PARTS OF SAID POLYAMIDE COMPOSITION IN THE FORM OF A COMPOUND SELECTED FROM THE CLASS CONSISTING OF MANGANOUS LACTATE, MANGANOUS OXALATE AND MANGANOUS HYPOPHOSPHITE, AND (4) BETWEEN 0.2 AND 1% OF A MONONUCLEAR CYCLIC ORGANIC ACID ANHYDRIDE SELECTED FROM THE GROUP WHICH CONSISTS OF THE ANHYDRIDES OF BENZOIC ACID AND HEXAHYDROPHTHALIC ACID, THE PROPORTIONS BEING BASED ON THE TOTAL WEIGHT OF THE COMPOSITION.