Flame retardant polyoxymethylene diphosphonates
AssigneeUniroyal, Inc.
InventorWadim Batorewicz
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Abstract
Polyoxymethylene diphosphonates having the formula ##STR1## wherein the R groups are the same or different and are selected from alkyl, haloalkyl, hydroxyalkyl, or (R.sup.1 and R.sup.2) or (R.sup.3 and R.sup.4) are joined together to form a ring structure are disclosed. These compounds are useful as flame retardants for organic resins in general, and especially for foamed polyurethane resins.
Claims12
A polyoxymethylene diphosphonate of the formula ##STR9## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same or different and are selected from the group consisting of alkyl having 1 to 6 carbon atoms, haloalkyl having 2 to 6 carbon atoms with the halogen being chlorine or bromine, hydroxyalkyl having 2 to 5 carbon atoms, R.sup.1 and R.sup.2, and R.sup.3 and R.sup.4 are respectively joined together to form ring structures having 2 to 3 carbon atoms said ring structures being optionally substituted with up to two methyl or chloromethyl groups, and wherein n is an integer from 1 to 3.
A process for preparing polyoxymethylene phosphonates comprising reacting paraformaldehyde at a temperature of from 50.degree. to 150.degree. C. with a phosphite having the formula ##STR10## wherein R is selected from alkyl having 1 to 6 carbon atoms and haloalkyl having 2 to 6 carbon atoms with the halogen being chlorine or bromine, R.sup.5 is alkylene having 2 to 3 carbon atoms optionally substituted with alkyl and haloalkyl groups having up to 3 carbon atoms with the halogen being chlorine or bromine, "a" has a value of 1 or 3, and "b" correspondingly has a value of 1 or 0.
Dependencies are inferred from the claim text.