Patent ID: 9187504
Filing Date: 2015-11-17
Classification: C07F,C08J,C08K,C08L

Abstract:
1. A method of making hydroxymethylphosphonate comprising heating paraformaldehyde in a solvent to a reaction temperature of from zero degrees Celsius to 75 degrees Celsius, wherein the solvent is hydroxyalkylphosphonate and which is present in at least an amount necessary to solvate or suspend the paraformaldehyde; adding at least one alkyl phosphite to the heated paraformaldehyde, to provide hydroxymethylphosphonate, the alkyl phosphite being added to the heated paraformaldehyde at a rate which will maintain an exotherm at no higher than 25 degrees Celsius above the reaction temperature, there being present in the reaction medium at least one hindered amine catalyst; and, optionally, following the completion of the addition, heating the reaction mixture to an elevated temperature.