Process for stabilizing hypophosphite
AssigneeRhodia (China) Co., Ltd.
InventorsFloryan De Campo, Annelyse Murillo, Junli Li, Tingting Zhang
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Abstract
A process for stabilizing hypophosphite salt is provided, which comprises the following steps: a) washing the hypophosphite salt at least one time under a controlled pH value of 4-11, preferably 5-8, as the said hypophosphite salt in an aqueous solution and/or in a solid state; and b) drying the said hypophosphite salt under reduced pressure to remove the volatiles. The process can prevent or minimize the formation of a dangerous quantity of phosphine from hypophosphite salts, more particularly in the flame retardant of the application. The flame retardant polymer composition is also provided, which comprises a polymer and the hypophosphite salt stabilized by the above process.
Claims15
A process for stabilizing a hypophosphite salt, comprising the steps of:
- step a) washing a starting hypophosphite salt at least one time under a pH value of 5 to 6 in an aqueous solution or in a solid state to obtain a washed hypophosphite salt, and
- step b) drying the washed hypophosphite salt to remove volatiles to obtain a stabilized hypophosphite salt,
- wherein the hypophosphite salt is of the formula (1):
- wherein n is 1, 2, or 3, and M is a metal selected from the group consisting of alkali metal, alkaline earth metal, aluminium, titanium, and zinc.
Dependencies are inferred from the claim text.