Patented Jan. 17, 1950 2,495,108 UNITED STATES PATENT OFFICE 2,495,108 ARYL PHOSPHATES OF POLY WINY ALCOHOL Gennady M. Kosolapoff, Dayton, Ohio, assignor to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware No Drawing. Application March 18, 1948, Serial No. 15,733 11 Claims. (C. 260-80) 1. 2 The present invention relates to phosphorus Accordingly these compounds may be described containing vinyl resins and more particularly to as having the general structure: aryl-substituted phosphates of polyvinyl alcohol or derivatives thereof containing free hydroxyl -CH-CH groups. This invention also provides a process b for producing the products. I have found that by causing compounds of the general formula: where R, is an aromatic hydrocarbon radical and Y Z may be an aromatic hydrocarbon radical or the R O-- O O grOUp: X wherein R, stands for an aromatic hydrocarbon -H-CH radical, X stands for halogen and Y stands for a The new products may be produced by mixing member of the group consisting of RO or haio 15 an arylphosphoryl halide and polyvinyl alcohol gen, to react upon polyvinyl alcohols or deriva or a derivative thereof containing free hydroxyl tives thereof containing free hydroxyl groups, groups and heating the mixture at a moderate there are obtained new, valuable phosphated temperature. resins which, according to the number and na The reaction which takes place causes a hy ture of hydroxyl groups available for phosphation 20 drogen halide to be liberated. Since the libera and the number and nature of phosphate groups tion of the hydrogen halide in the presence of which have entered the molecule, possess dif polyvinyl alcohol may cause Some undesirable ferent properties in respect to solubility, hard discoloration or decomposition of the polyvinyl neSS, plasticity, flame-resistance. As examples alcohol to take place, particularly at the higher of Compounds having the above general formula 25 concentrations of hydrogen halide, it is desirable, I may mention phenylphosphoryl dichloride, di although not necessary, to have present in the phenylphosphoryl chloride, the tolylphosphoryl reaction mass at the time of liberation of hydro dichlorides, the ditolylphosphoryl chlorides, the gen halide a basic material which will combine xylylphosphoryl dichlorides, the dixylylphos with the hydrogen halide so as to eliminate or to phoryl chlorides, the naphthylphosphoryl di 30 diminish the concentration thereof. chlorides, the dinaphthylphosphoryl chlorides, As the basic material for this purpose, I may etc. The products obtained by the phosphation use any substance which will combine with Or by when employing a diarylphosphoryl halide con its presence neutralize or decrease the hydrogen tain at least one group of the following formula: ion activity of the hydrogen halide. Suitable 35 materials are any alkaline or alkaline earth hy droxides or carbonates or organic tertiary bases such as pyridine, picoline, quinoline, methyl quinoline, dimethyl aniline, diethyl aniline, di methyl cyclohexylamine, diethyl cyclohexyl 40 amine, trialkylamines, N-alkyl morpholines, etc. These materials may be used separately or in The products obtained by the phosphation when combination. When pyridine is used it may also employing an arylphosphory dihalide contain at Serve as a Solvent for carrying out the reaction. least one member of the group consisting of: When basic materials which are not Solvents are 45 to be employed, another solvent, diluents or dis H II H persing agents such as ethylene dichloride, -(-CH-)- -C-CH chloroform, carbon tetrachloride, benzene, tol b O is:t uene, etc. may be employed. Yp16 and o--ors.;w The polyvinyl arylphosphates obtained by re 50 action of polyvinyl alcohol with the arylphos g phoryl halides differ remarkably from polyvinyl R --OH,- alcohol. They are water-insoluble; a film of the r resin prepared by casting a solution of the Same The group is completely resistant to water, i. e., water rolls -C-CE 55 of it and does not spread nor penetrate. Such a film is flexible, elastic and mechanically strong. is the Sole repeating unit in the chain. When exposed to an Open flame, the film does

2,495,108 3 4. not support combustion; it merely shrinks and phosphate without adversely affecting the other chars. Products of exceptionally good mechani desirable properties thereof. cal properties are obtainable by only partially phosphating the polyvinyl alcohol, and then re Eacample 3 acting the partially phosphated material with 5 This example describes the reaction of poly an aldehyde Such as butyraldehyde for the pro vinyl alcohol with phenylphosphoryl dichloride. duction of polyvinyl arylphosphate butyrals. Any Twenty two grams of polyvinyl alcohol was aliphatic aldehyde having from one to four car Suspended in 200 cc. of dry pyridine with vigorous bon atoms, and including formaldehyde, acetalde Stirring. The resulting suspension was heated hyde, propionaldehyde or butyraldehyde may be 10 to a temperature of from 45° C. to 48° C., and to used. Polyvinyl arylphosphate acetals are also it Was added, dropWise, 53 grams of phenylphos obtainable by reaction of a partial acetal of poly phoryl dichloride. No visible change was ob Vinyl alcohol with an arylphosphoryl halide. Served during a period of approximately 1% The invention is illustrated, but not limited, by hours; then reaction occurred suddenly and vio the following examples: 5 lently. The suspension rapidly gelled and solid Eacample 1 ified, absorbing all solvent. Accordingly, the re action mass was cooled, removed from the reac Polyvinyl alcohol was prepared by hydrolysis of tion vessel, and placed into a large volume of wa the polyvinyl acetate known to the trade as ter. After thoroughly kneading the mass in the Gelva. 20 Water, dilute sodium hydroxide being added in Twenty two grams of the polyvinyl alcohol was order to maintain the water slightly alkaline, the Suspended, with vigorous stirring, in 600 cc. of re reaction product was obtained as a white, pliable distilled pyridine, employing a flask provided with maSS Which differed essentially from the initial a mercury sealed stirrer, reflux condenser polyvinyl alcohol. Besides being entirely insol equipped with a calcium chloride drying tube, 26 and a dropping funnel. The flask was placed in uble in Water, it was non-inflammable. a thermostat maintained at a temperature of 50° Eacample 4 C., and 150 grams of diphenylphosphoryl chloride Was added to the polyvinyl alcohol-pyridine mix This example describes the reaction of phenyl ture during a period of 30 minutes. The reaction 30 phosphoryl dichloride with a polyvinylbutyral, mixture was then stirred mechanically at a tem known to the trade as Butvar, and containing perature of 50° C. for 26 hours. At the end of 80% of butyral groups and 20% of hydroxyl this time the product was pressure filtered at groupS. 50-60 pounds of pressure. The clear, yellowish Twenty five grams of vacuum-dried Butwar was filtrate obtained in this manner was allowed to 35 Suspended in 710 cc. of ethylene chloride, em stand overnight in a stoppered flask and was ploying a 3-necked, round-bottom flask equipped Subsequently precipitated very slowly by dropwise With thermometer, dropping funnel, mercury sealed stirrer and a reflux condenser to which addition to Vigorously stirred Water With Small WaS attached a calcium chloride drying tube. To additions of sodium hydroxide to preserve alka the Butvar-ethylene dichloride mixture there was linity. The product was then thoroughly mace 40 then added 25 cc. of dried pyridine and then 11.4 rated in dilute sodium hydroxide and several grams of phenylphosphoryl dichloride was added changes of Water, and it was then allowed to dry. through the dropping funnel during a period of At this stage it was an exceedingly elastic, rub from 5 to 6 minutes. Several minutes after the bery, white solid. For further purification, it addition was completed, the suspension began to was dissolved in benzene and slowly precipitated 45 clear up rapidly. In a few minutes it was com by adding the benzene solution to hexane. Dry pletely clear and quite fluid, and the temperature ing of the precipitated mass was effected in vac of the mixture had risen to about 29° C. After uum at a pressure of 2 mm. Stirring for 75 minutes, no further change in the Analysis of the product shows a phosphorus thin Syrupy liquid was observable. Heat was ap content of 10.98%, as against a 11.22% theoreti 50 plied by means of an electric hot plate. As the cal phosphorus content of polyvinyl diphenyl temperature rose over 35° C., the viscosity of the phosphate; hence 98% esterification of the poly Solution increased abruptly and continued to in vinyl alcohol has been attained. crease as the temperature was raised to 58° C., The polyvinyl diphenylphosphate obtained in at which stage the contents of the flask was a the present example is rubbery and elastic. It 55 Colorless gel. This gel was removed from the possesses a considerable degree of adhesion to flask and placed into a beaker of hexane, stirred solids, is insoluble in Water, and is non-inflam and Subdivided as minutely as possible. It was mable when exposed to an open flame. then placed into the colloid mill, hexane was Eacample 2 60 added to it, and the whole was milled for a time Subsequent acetallation of the polyvinyl di of about 6 minutes. The product thus formed phenylphosphate prepared in Example 1 was a coarse, yellowish-green powder. Color was effected in the following manner: removed from the powder by washing it with Wa Twenty grams of the ester was dissolved in 300 ter and then vacuum-drying it at a temperature cc. of ethylene dichloride, treated with 35 cc. of 65 of 45 C. There was thus obtained a white, tough butyraldehyde and 50 grams of freshly ignited resin which had a phosphorus content of 5.23% Sodium sulfate. The flask was then securely as against a 5.17% theoretical phosphorus con stoppered and placed on a shaking wheel for over tent of a polyvinyl alcohol having 80% of its hy night. At the end of this time the reaction mix droxyl groups converted to butyral groups and ture was filtered, and the clear filtrate was slowly 70 20% of its hydroxyl groups converted to phenyl precipitated by hexane. The resin which sepa phosphate groups. rated out was washed in hexane and vacuum The White resin obtained in this example was dried. The acetalation had resulted in the intro completely insoluble in water, was non-inflamma duction of a plurality of acetal groups and con ble and showed mechanical properties compara siderable Stiffening of the polyvinyl diphenyl 75 ble to those of Butvar. Its advantage over Butwar

2,495,108 6 5 tion of the arylphosphate radicals into the same lies in its substantially no water absorption and conferring increased water-resistance and sub its flame-resistance. stantial non-inflammability. The production of Eacample 5 Such phosphorus-containing resins may be ef fected by either partial phosphation of polyvinyl This example describes the reaction of the alcohol and subsequent etherification or esterifi Butwar of Example 4 with diphenylphosphoryl cation of the remaining free hydroxyl groups, or chloride. Twenty grams of vacuum-dried Butwar was dis by reaction of partially esterified or partially solved in 600 cc. of ethylene dichloride and then etherified polyvinyl alcohol with the arylphos treated, with stirring, with 25 cc. of pyridine and phates. 30 grams of diphenylphosphoryl chloride at 52° C. This application is a continuation-in-part of for 24 hours. The product was then slowly pre application Serial No. 468,825, filed December 12, cipitated by hexane and allowed to stand in fresh 1942, now abandoned. hexane overnight. Subsequently it was thorougil What I claim is: ly washed with dilute sodium hydroxide and then 5 1. The reaction product of an aromatic phos put through the colloid mill for about six minutes, phoryl halide and a macromolecular polyvinyl alcohol. at the end of which time it was washed With Water 2. The aryl phosphate of polyvinyl alcohol. andThere dried. were thus obtained clear, substantially 3. The diary phosphate of polyvinyl alcohol. colorless granules of phosphated Butwar having 4. The phenyl phosphate of polyvinyl alcohol. a softening point of 100° C. and a melting point of 5. The process which comprises mixing poly 160° C. The product is soluble in chloroform, ace vinyl alcohol and an aryl phosphoryl halide and tone and dioxane, partly soluble in benzene, ethyl heating the mixture at a moderate temperature alcohol and ethyl acetate and insoluble in hexane until esterification is effected. and Water. It is non-inflammable. 6. The process which comprises mixing to The term “polyvinyl alcohol' is used herein to gether polyvinyl alcohol and diphenylphosphoryl describe the product which is phosphated. Poly chloride and heating the mixture at a moderate vinyl alcohol is the product of the hydrolysis of a temperature until esterification is effected. polyvinyl ester such as polyvinyl acetate. For 7. The process which comprises mixing poly the present purpose, it is possible to start with the 30 vinyl alcohol, an aryl phosphoryl halide and a product of the complete hydrolysis of such poly basic reagent, and heating the mixture at a mod vinyl acetate or it is also possible to start with the erate temperature until esterification is effected. product of the incomplete hydrolysis of such 8. The process which comprises mixing poly ester. Products obtained by the incomplete, hy vinyl alcohol, an aryl phosphoryl chloride and a drolysis may contain of the total as much as 30% 35 basic reagent, and heating the mixture at a mod of the residues of unhydrolyzed vinyl acetate. A erate temperature until esterification is effected. commercially available product which is preferred 9. The process which comprises mixing poly for the present purpose contains from 0.5% to 6% vinyl alcohol, diphenyl phosphoryl chloride and a of vinyl acetate groups, the balance being vinyl basic reagent, and heating the mixture at a mod alcohol groups. Such product is a macromolecul 40 erate temperature until esterification is effected. lar polymer and may have a molecular weight of 10. The process which comprises mixing poly at least 1,000. However, other products may like vinyl alcohol, diphenyl phosphoryl chloride and Wise be employed. pyridine and heating the mixture at a moderate The above examples describe the general reac temperature until esterification is effected. tion of polyvinyl alcohol or partially acetalated 11. The process which comprises mixing poly polyvinyl alcohol with arylphosphoryl halides. vinyl alcohol, an aryl phosphorylhalide and pyri The present invention is also applicable to the dine and heating the mixture at a moderate tem preparation of arylphosphates of other deriva perature until esterification is effected. tives of polyvinyl alcohol containing free hydroxyl GENNADY M. KOSOLAPOFF. groups, for example, partially etherified or par tially esterified polyvinyl alcohols, the introduc No references cited,