Patent GB-1066405-A (GB)
Title: Process for the manufacture of neutral polyphosphoric ester anhydrides
IPC: C08G79/04
Filed: 1965-10-28
Abstract: Neutral polyphosphoric ester anhydrides are obtained by reacting phosphorus compounds or mixtures of said phosphorus compounds of the formula <FORM:1066405/C2/1> wherein m and n each represents 1 or 2 and m+n=3, R1 represents saturated, unsaturated, oxyalkylated and halogenated aliphatic, cycloaliphatic or aromatic radicals each containing 1 to 10 carbon atoms and R represents a saturated aliphatic or haloaliphatic radical containing 1 to 5 carbon atoms, with P2O5, optionally in the presence of a solvent, at a temperature within the range of from -78 DEG  to +140 DEG  C.  0.01 to 20 moles per mole of P2O5 of the phosphorus compound is preferably used and the reaction is preferably effected under an inert atmosphere, e.g. N2, suitable solvents being halogenated hydrocarbons boiling within the range of from 30 DEG  to 120 DEG  C. such as CHCl3, CH2Cl2, CCl3.CH3, CCl4, CH2Br2, CHCl2.CH3, CH2Cl.CH2Cl, CHCl2.CH2Cl, CCl2=CHCl, CCl2=CCl2, CF3.CCl3 and CFCl2=CFCl2 and mixtures thereof. After completion of the reaction the products if no solvent was used are preferably dissolved in one of the above solvents and may be precipitated by the addition of a liquid precipitating agent, e.g. low molecular weight alkanes and cycloalkanes containing 5 to 12 carbon atoms which are liquid at room temperature such as hexane, heptane, octane and cyclohexane, aliphatic and cyclic ethers such as diethyl ether, tetrahydrofuran, glycol dimethylether and dioxan, and benzene or mixtures thereof.  The products are stated to be mixed anhydrides of partially hydrolysed esters of polyphosphoric acid with partially or completely hydrolysed esters of phosphonic acid and/or esters of phosphinic acid and to contain a mixture of open-chain, cyclic and combined open-chain/cyclic molecules with polyphosphate units containing hydrocarbyl-substituted phosphorus atoms.  The products may be used as polymerization catalysts in the polyacetal field.ALSO:Condensed neutral polyphosphoric ester anhydrides are obtained by reacting phosphorus compounds or mixtures of said phosphorus compounds of the formula <FORM:1066405/C3/1> where m and n each represents 1 or 2 and m+n =3, R1 represents saturated unsaturated, oxyalkylated or halogenated aliphatic, cycloaliphatic or aromatic radicals, each containing 1 to 10 carbon atoms and R represents a saturated aliphatic or haloaliphatic radical containing 1 to 5 carbon atoms, with P2O5, optionally in the presence of a solvent, at a temperature within the range of from - 78 DEG  to +140 DEG  C.  The amount of the phosphorus compound used is preferably 0.01 to 20 moles per mole of P2O5 and the reaction is preferably effected under an inert atmosphere e.g. N2, suitable solvents being halogenated hydrocarbons boiling within the range of from 30 DEG  to 120 DEG  C. or mixtures thereof.  After completion of the reaction the products if no solvent was used are preferably dissolved in one of the above solvents and may be precipitated by the addition of a liquid precipitating agent, e.g. low molecular weight alkanes and cycloalkanes containing 5 to 12 carbon atoms which are liquid at room temperature such as hexane, heptane, octane and cyclohexane, aliphatic and cyclic ethers such as diethyl ether, tetrahydrafuran, glycol dimethyl ether and dioxan, and benzene or mixtures thereof. The products are stated to be mixed anhydrides of partially hydrolysed esters of polyphosphoric acid with partially or completely hydrolysed esters of phosphoric acid and/or esters of phosphinic acid and to contain a mixture of open-chain, cyclic and combined open-chain/cyclic molecules with polyphosphate units containing hydrocarbyl-substituted phosphorus atoms.  The products may be used as polymerization catalysts in the polyacetal field. In an example, trioxan is polymerized or copolymerized, e.g. with glycol formal, in the presence of one of the above products as a catalyst.