Mixtures of aluminum hydrogenphosphites with aluminum salts, process for the production thereof and the use thereof

A process for preparing a mixture of aluminum hydrogenphosphites of the formula (I)

• Al2.00(HPO3)v(H2PO3)yx(H2O)z (I)
• with aluminum salts comprising
• 91 to 99.9% aluminum hydrogenphosphites of the formula (I)
• 0.1 to 9% aluminum salts and
• 0 to 50% water (of crystallization),
• where v in formula (I) is 2 to 2.99, y is 2 to 0.01 and z is 0 to 4 comprising the step of reacting an aluminum source and a phosphite source without solvent at temperatures of 20 to 300° C. for 0.1 to 10 h.

A flame-retardant thermoplastic or thermoset polymer molding composition or polymer molding, film, filament or fiber comprising 0.1 to 45% by weight of a mixture of aluminum hydrogenphosphites of the formula (I)

• Al2.00(HPO3)v(H2PO3)yx(H2O)z (I)
• with aluminum salts comprising
• 91 to 99.9% aluminum hydrogenphosphites of the formula (I)
• 0.1 to 9% aluminum salts and
• 0 to 50% water (of crystallization),
• where v in formula (I) is 2 to 2.99, y is 2 to 0.01 and z is 0 to 4, 55 to 99.9% by weight of thermoplastic or thermoset polymer or mixtures thereof, 0 to 55% by weight of additives and 0 to 55% by weight of filler or a reinforcing material, where the sum of the components is 100% by weight.

An intermediate for further syntheses, a binder, a crosslinker or accelerator in the curing of epoxy resins, polyurethanes and unsaturated polyester resins, a polymer stabilizer, a crop protection composition, a sequestrant, a mineral oil additive, as an anticorrosive, a washing composition a cleaning composition or an electronic composition including a mixture of aluminum hydrogenphosphites of the formula (I)

• Al2.00(HPO3)v(H2PO3)yx(H2O)z (I)
• with aluminum salts comprising
• 91 to 99.9% aluminum hydrogenphosphites of the formula (I)
• 0.1 to 9% aluminum salts and
• 0 to 50% water (of crystallization),
• where v in formula (I) is 2 to 2.99, y is 2 to 0.01 and z is 0 to 4.

A flame retardant, a flame retardant for clearcoats and intumescent coatings, a flame retardant for wood and other cellulosic products, a reactive and nonreactive flame retardant for polymers, a flame-retardant polymer molding composition, a flame-retardant polymer molding a flame retardant for rendering polyester and pure and blended cellulose fabrics flame-retardant by impregnation, or a synergist in flame retardant mixtures comprising a mixture of aluminum hydrogenphosphites of the formula (I)

• Al2.00(HPO3)v(H2PO3)yx(H2O)z (I)
• with aluminum salts comprising
• 91 to 99.9% aluminum hydrogenphosphites of the formula (I)
• 0.1 to 9% aluminum salts and
• 0 to 50% water (of crystallization),
• where v in formula (I) is 2 to 2.99, y is 2 to 0.01 and z is 0 to 4.

A flame-retardant thermoplastic or thermoset polymer molding composition or polymer molding, film, filament or fiber comprising 0.1 to 45% by weight of a mixture of aluminum hydrogenphosphites of the formula (I)

• Al2.00(HPO3)v(H2PO3)yx(H2O)z (I)
• with aluminum salts comprising
• 91 to 99.9% aluminum hydrogenphosphites of the formula (I)
• 0.1 to 9% aluminum salts and
• 0 to 50% water (of crystallization),
• where v in formula (I) is 2 to 2.99, y is 2 to 0.01 and z is 0 to 4 55 to 99.9% by weight of a flame retardant, 55 to 99.9% by weight of thermoplastic or thermoset polymer or mixtures thereof, 0 to 55% by weight of additives and 0 to 55% by weight of filler or a reinforcing material, where the sum of the components is 100% by weight.