Sulfuric Acid → ethylphosphonous acid aluminum(III) salt

Temperature

100 °C

1500 g (14 mol) of sodium hypophosphite monohydrate are dissolved in 7.5 kg of water and initially charged in a 16 l steel-enamel jacketed pressure reactor. After heating the reaction mixture to 100° C., a reducing valve set to 6 bar was used to introduce ethylene into the reactor up to saturation. While stirring constantly at an ethylene pressure of 6 bar and a temperature of 100-110° C., a solution of 33 g (1 mol %) of sodium peroxodisulfate in 300 g of water is metered in homogeneously. At a conversion of ethylene of 85.3%, the metered addition of sodium peroxodisulfate is stopped and the reactor is decompressed. After cooling to about 90° C., 700 g of concentrated sulfuric acid are metered in within 30 minutes. Subsequently, 364 g (4.67 mol) of aluminum hydroxide are added and the mixture is heated to 150° C. in a closed reactor for 8 h. After cooling to ambient temperature, the resulting solid is filtered off, washed with 2 l of hot water and dried at 130° C. under reduced pressure. The resulting mixture comprises diethylphosphinic acid aluminum(III) salt and ethylphosphonous acid aluminum(III) salt in a ratio of 79.6% by weight of diethylphosphinic acid aluminum(III) salt and 20.4% by weight of ethylphosphonous acid aluminum(III) salt (89.7% yield).

1. customa reducing valve set to 6 bar
2. customa temperature of 100-110° C.
3. temperatureAfter cooling to about 90° C.
4. customare metered in within 30 minutes
5. temperaturethe mixture is heated to 150° C. in a closed reactor for 8 h
6. temperatureAfter cooling to ambient temperature
7. filtrationthe resulting solid is filtered off
8. washwashed with 2 l of hot water
9. customdried at 130° C. under reduced pressure

ORD record

ord-49fff9654d2346e1ad358021605e74f5

Source dataset

uspto-grants-2014_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08889772B2