GB865750A - Spiro-phosphonium salts - Google Patents

Abstract

Foamed polymers resistant to flame are prepared by heating a mixture of a liquid viscous polymer, such as may be obtained from propylene oxide and toluene di-isocyanate, with a small amount of a spiro-phosphonium salt of the general formula:- <FORM:0865750/IV (a)/1> wherein X represents the anion of a water-soluble inorganic or organic acid and Y1 and Y2 represent the same or different substituted or unsubstituted radicals which are saturated or unsaturated alkylene groups providing 1-5 carbon atoms in the P-containing ring or arylene or saturated or unsaturated cycloalkylene groups in which 2-4 consecutive carbon atoms of the arylene or cycloalkylene ring provide respectively 2-4 consecutive carbon atoms in the P-containing ring. Substituents which may be present are halogen, cyano, hydroxyl, carbamyl, acyloxy, carboxy, carbalkoxy, alkoxy, aryl and aryloxy. The phosphonium chloride wherein Y1=Y2= -CH2-CH2- on heating to above its melting point expands to several times its volume with evolution of gas and solidifies on cooling to a flame-resistant hard resin. The preparation of the phosphonium salts is described (see Group IV(b)).ALSO:The invention comprises spiro-tetra kis hydroxy phosphonium salts of the general formula: <FORM:0865750/IV (b)/1> wherein X- represents the anion of a water-soluble acid and Y1 and Y2 represent the same or different substituted or unsubstituted saturated or unsaturated alkylene groups providing 1-5 carbon atoms in the P-containing ring, substituted or unsubstituted arylene groups in which 2-4 consecutive ring carbon atoms of the arylene ring provide respectively 2-4 consecutive ring carbon atoms in the P-containing ring or substituted or unsubstituted saturated or unsaturated cycloalkylene groups in which 2-4 consecutive ring carbons similarly provide respectively 2-4 ring carbon atoms in the P-containing ring. Substituents which may be in Y1 and Y2 include halogen, cyano, hydroxyl, carbamyl, acyloxy, carbalkoxy, carboxy, alkoxy, aryl and aryloxy groups. Compounds of the above formula wherein X-represents a water-soluble mineral acid anion may be prepared by bringing phosphine and the mineral acid into contact with at least one di-aldehyde of the formula OHC-Y-CHO or a compound capable of forming such an aldehyde in situ, in the presence of water. The dial and phosphine may be used in stoichiometric amounts or with either in excess. Generally, at least one equivalent of mineral acid is used per equivalent of phosphine taking part in the reaction. Temperatures of about 0 DEG -100 DEG C. are suitable. Organic solvents may be present. The resulting phosphonium mineral acid salts may be reacted with suitable salts of organic acids, such as lead, silver, mercury, barium and calcium acetates, citrates and tartrates to provide the corresponding phosphonium organic acid salts by anion exchange. Compounds of the above formula wherein X-is a chloride ion may be reacted with silver nitrate to form the phosphonium nitrate. In the Examples: (1) aqueous glutaraldehyde and gaseous phosphine are added slowly to a mixture of aqueous HCl and tetrahydrofuran containing dissolved phosphine and the reaction mixture worked up to recover spiro-1, 5, 7, 11-tetrahydroxy-6-phosphazoniahendecane chloride (Y1=Y2=trimethylene); the sulphate, acid sulphate and dihydrogen phosphate are prepared in like manner from suitable amounts of aqueous sulphuric and phosphoric acids respectively; the phosphonium chloride is reacted with aqueous silver nitrate or tartrate to give the corresponding phosphonium nitrate or tartrate and the sulphate salt is reacted with barium acetate in water to yield the phosphonium acetate; (2) succinaldehyde or its stable acetal 2: 5-diethoxy-tetrahydrofuran is reacted as in (1) to yield spiro-1, 4, 6, 9-tetrahydroxy-5-phosphazonianonane chloride or sulphate, the latter being converted into the acetate as above. Other diols specified include 3-chloro, 3-p-chlorophenyl, 3-carbamyl, 3-methylene and 3-acyloxy glutenaldehydes, o-phthaldehyde, 2-cyano-malonaldehyde, 2-hydroxy and 3-methoxy adipaldehydes, 4-carboxy phthaldehyde and 2-carbomethoxy succinaldehyde. The phosphonium salts may be used in the manufacture of foamed polymers (see Group IV(a).ALSO:Foamed polymers resistant to flame are prepared by heating a mixture of a liquid viscous polymer, such as may be obtained from propylene oxide and toluene di-isocyanate, with a small amount of a spiro-phosphonium salt of the general formula <FORM:0865750/IV/1> wherein X represents the anion of a water-soluble inorganic or organic acid and Y1 and Y2 represent the same or different substitutes or unsubstituted radicals which are saturated or unsaturated alkylene groups providing 1-5 carbon atoms in the P-containing ring or arylene or saturated or unsaturated cyclo alkylene groups in which from 2 to 4 consecutive carbon atoms in the arylene or cyclo alkylene ring provide respectively from 2 to 4 consecutive carbon atoms in the P-containing ring. Specified substituents are halogen, cyano, hydroxyl, carbamyl, acyloxy, carboxy, carbalkoxy, alkoxy, aryl and aryloxy groups. The phosphonium chloride wherein Y1 and Y2 each represent-CH2- CH2- on being heated to above its melting point expands to several times its volume with evolution of gas and solidifies on cooling to a flame-resistant hard resin. The preparation of the phosphonium salts is described (see Group IV(b)).