Copolycondensation products of .beta.-haloalkyl phosphates and dialkyl phosphonates
AssigneeStauffer Chemical Company
InventorEdward D. Weil
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Abstract
Copolycondensation products of .beta.-haloalkyl phosphates and dialkyl phosphonates are useful fire retardant agents. The products are prepared by heating the starting materials at a temperature of about 110.degree. to 250.degree. C., preferably in the presence of a nucleophilic catalyst, until at least one mole of alkyl halide per mole of phosphonate is driven off. Preferred are copolycondensation products obtained by substantially complete removal of halogen as alkyl halide.
Claims5
A copolycondensation product of a .alpha.-haloalkyl phosphate having from 2 to 4 carbon atoms in the alkyl moiety and a dialkyl phosphonate of the formula ##STR27## in which R' is alkyl of from 1 to 20 carbon atoms, alkenyl of from 3 to 20 carbon atoms, or phenyl optionally substituted with alkyl of from 1 to 4 carbon atoms and/or halogen, and R is alkyl of from 1 to 4 carbon atoms, said product being obtained by the steps of (1) heating the phosphate with the dialkyl phosphonate until at least about 1 molar equivalent of alkyl halide is evolved, to obtain a crude polycondensation product having acidic structures, and (2) substantially neutralizing said acidic structures by heating the crude product with an epoxide or an orthoester.
A copolycondensation product of tris(2-chloroethyl) phosphate and dimethyl methylphosphonate obtained by the steps of (1) heating tris(2-chloroethyl) phosphate and dimethyl methylphosphonate until at least one molar equivalent of methyl chloride is evolved, to obtain a crude polycondensation product having acidic structures, and (2) substantially neutralizing said acidic structures by heating the crude product with an epoxide or an orthoester.
Dependencies are inferred from the claim text.