Phosphorus-containing spirobi (meta dioxane) polymers

Flame-resistant resins are prepared by heating at 60 DEG -150 DEG C an aliphatic polyhydric alcohol, a pentaerythritol phosphorous acid ester and a 3,9-dialkenylspirobi(meta-dioxane) having the general formula wherein each R1 is a hydrogen atom, a chlorine atom or a methyl group and each R2 is a hydrogen atom or a methyl group. Pentaerythritol phosphorous acid ester is defined as the hydrolysed reaction product of at least two mols. of phosphorus trichloride with one mol. of pentaerythritol. Specified polyhydric alcohols include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 2-ethylhexane-1,3-diol, ditri- and penta-ethylene glycol, di- and tri-propylene glycol, glycerol, 1,2,4-butanetriol, trimethylol ethane, trimethylol propane, pentaerythritol, sorbitol, mannitol, dulcitol and 2,4-dihydroxy-1,3-di(hydroxymethyl) pentane. The reaction mixture usually includes an acidic catalyst such as sulphuric acid, toluenesulphonic acid, benzenesulphonic acid, boron trifluoride, aluminium chloride, stannic chloride, titanium tetrachloride, phenyl acid phosphate and octylphenyl acid phosphate. In a modification acrolein is reacted with pentaerythritol in the presence of an acid catalyst to produce a liquid pre-condensate A-stage resin which is then reacted with the pentaerythritol phosphorous acid ester also in the presence of an acid catalyst. Examples 2-6 illustrate the two embodiments of the invention. Reference has been directed by the Comptroller to Specification 822,668.ALSO:Pentaerythritol phosphorus acid ester, utilized for chemically incorporating phosphorus into polymers (see Group IV(a)), is prepared by hydrolysis of the reaction product of at least 2 moles of phosphorus trichloride with one mole of pentaerythritol (In the ester the tautomeric equilibrium is believed to exist). Example 1 describes the preparation of the ester. Reference has been directed by the Comptroller to Specification 822,668.