United States Patent Office Patented July 9, 1968

3,392,214 United States Patent Office Patented July 9, 1968

15 (preferably trimeric) with a phosphorus chloride selected 3,392,214 from the group consisting of phosphorus pentachloride CYCLOTRIPHOSPHAZATRIENE COMPOUNDS triphenoxy phosphorus dichloride and triphenyl phos- AND PROCESS FOR MAKING SAME phorus dichloride, and recovering the resulting product, Daniel J. Jaszka, Tonawanda, N.Y., assignor to Hooker Chemical Corporation, Niagara Falls, N.Y., a corpora- which may thereafter be polymerized to a useful polymer. tion of New York 20 Additionally, the process of this invention includes react- No Drawing. Filed Mar. 2, 1964, Ser. No. 348,877 ing diaminocyclophosphazene with phenol to form a 11 Claims. (CI. 260—927) phenolated diaminocyclophosphazene compound, which may be treated with a phosphorus chloride and This invention relates to cyclophosphazene products, polymerized. including polymers thereof, and to processes for preparing 25 The exact structure of some of the new intermediate them. products and final polymers produced by the processes of The prior art discloses that cyclophosphazene polymers this invention, has not been definitively established. How- which have good thermal stability have been made, but ever, it is believed that the following equations con- often such polymers are not as hydrolytically stable as is stitute correct representations of the reactions effected desirable. In fact, many such polymers have a very rapid 30 and the products formed according to this invention.

Cl NEi CnHsO NHj CaHsO N=PC13 V V V ^ \ ^ \ ^ \ Cl N N Cl C.HtOH N NT OCjHs PCls N N OCiHs 300° C. M Jl/ > I 11/ • I Polymer p p KOH (C«H50)sP P (CSHSO)JP V \ ^ / \ ^ / \ .01 N NHj N. NH, N N=PCU (III) (IV) (I) (IX) sfCjBWjPOli

C1H5O N=P(C6Hs)3 P ^ \ N N OC4H5 400° C. -> Polymer (CjIIjOJii- Y ^ / \ N N=P(C«Ht)i (V) (VI)

C«Hs0 N=P(OC«Hs)3 P \ (C6H50)3P Clj N N OCtHs Polymer (081150)21 ^ / Y\ N N=P(0C6Hs)3 (VIII) (VII) hydrolysis rate. Therefore, it is very desirable to find a Compounds II, III, V, VII, IX, XI, and XIII may be cyclophosphazene derivative which can be reacted to 60 considered cyclotriphosphazatriene of the formula, produce a polymer which has both good thermal stability and enhanced hydrolytic stability. Such products are A Y useful as materials of construction for formed articles, V such as structural parts, covers, gaskets or plastic con- A N^ \l A sumer articles subjected to heat and high humidities, and 65 \l [1/ may be employed with other plastics or polymers in P P molding compositions. Such products are described in AN/ ^ / Y V this application. In accordance with this invention there is provided wherein A is selected from the group consisting of such a product and a process for preparing it, a cyclo- 70 chlorine and phenoxy; and Y is selected from the group phosphazene polymer of increased hydrolytic stability, consisting of —NH2, —N=PC13, —N=P(C6H50)3 and which comprises reacting diaminocyclophosphazene, —N=P(C6H5)3, and A is phenoxy when Y is —NH2. 3,392/214 4

CI Nil! CI N=PC13 \ / P V \ ^ \ CI N N CI PClt CI N N CI 300° C. \l 11/ Polymer P P —- \l p p11 / / ^ / \ / ^ / \ CI N NHj CI N N—P Ch (I) (IX) (X) \ \(C,H,)aI>Cla \ \ CI N=P(C„HS)3 V ^ \ CI N N CI \l 11/ Polymer P P / ^ / \ CI N N=P(C«HS)3 (XII) (XI)

CI N=P(OCjHS)3

^ \ (CeHiiObPClj CI N N CI \l 11/ Polymer P P A / ^ / \ CI N N=P(OCiH()J (XIV) (XIII) It will be convenient in the balance of this specification avoid premature polymerization of the phosphazene to refer to these compounds by the assigned identifying molecule. The monomers are prepared by reacting a Roman numerals. The type of compound shown herein stoichiometric amount or a slight excess of phosphorus is often described as a phosphonitrilic halide derivative. chloride with the desired phosphazene molecule, prefer- However, this term is less descriptive than the term 30 ably in a halogenated solvent. The reaction is continued phosphazene, since nitrile implies a under reflux conditions until the cessation of hydrogen chloride evolution. Thereafter, the reaction product is -CsN- filtered and is freed of solvent by distillation. It is preferable that the solvent be distilled under vacuum condi- bond, whereas the compounds of this invention have no 35 tions. Pressures of 5 to 10 millimeters >of mercury and such bonds. Using the phosphazene nomenclature, these lower -are satisfactory. compounds are named as follows: To make the intermediate product, compound II, an I. 2,2,4,6-tetrachloro-4,6-diaminocyclotriphosphazatri- excess of phenol as an alkali salt thereof is employed ene; to insure complete pbenolation of the product. While II. 2,2,4,6-tetraphenoxy-4,6-diaminocyclotriphosphaza- 40 it is preferable to use potassium hydroxide to form the triene; phenate, other alkali metal hydroxides, such as sodium III. 2,2,4,6-tetraphenoxy-4,6-di(trichlorophosphazo) hydroxide, are also suitable. The reaction is compelted cyclotriphosphazatriene; when the distillation of water ceases. The reaction mix- V. 2,2,4,6-tetraphenoxy-4,6-di(triphenylphosphazo)cy- ture is then cooled and neutralized with alkali, such as clotriphosphazatriene ; 45 potassium hydroxide, and dried with anhydrous sodium VII. 2,2,4,6-tetraphenoxy-4,6-di(triphenoxyphosphazo)- sulfate. Thereafter, the solvent is removed by distillation. cyclotriphosphazatriene; The monomers of this invention, compounds III, V, IX. 2,2,4>6-tetrachLoro-4,6-di(trichlorophosphazo)cyclo- VII, IX, XI and XIII are heated in the absence of oxy- triphosphazatriene; gen until polymerized. Preferably the monomers are heat- XI. 2,2,4,6-tetrachloro-4,6-di(triphenylphosphazo)cyclo- 50 ed at a temperaure from 200 to about 400 degrees centi- triphosphazatriene; grade, for a period of about one-half hour to thirty XIII. 2,2,4,6-tetrachIoro-4,6-di(triphenoxyphosphazo) - hours. The resulting polymers are characterized by their cyclotriphosphazatriene. excellent hydrolytic stability and heat resisting properties. The diaminohalophosphazene starting material, com- The invention is illustrated by the following non-lim- 55 pound I, is conveniently prepared by aminolysis of cyclic- iting examples. Temperatures are expressed in degrees phosphazene chloride according to the method of De centigrade and parts are by weight unless otherwise indi- Ficquelmont, A. M., Ann. chim., 12, 169 (1939). cated. It is desirable to prepaare the monomeric products of Example 1 this invention, compounds III, V, VII, IX, XI and XIII GO To a reaction vessel containing 344 parts p-xylene and intermediate II in an organic reaction medium. It and equipped with a water-cooled condenser were is preferable in the case of preparation of the aforemen- charged 48 parts of the prior art compound (compound tioned monomers to use a chlorinated solvent, such as I), 61 parts of phenol and 53 parts of potassium hydrox- monochlorobenzene, trichlorobenzene, orthodichloro- ide (85 percent). The mixture was refluxed at about 155 benzene, symmetrical-tetrachloroethane, tetrachloroeth- 65 degrees centigrade for about 10 hours, the HC1 being ylene, benzyl chloride, chloroform and carbon tetra- then removed, after which water was distilled off. After chloride. In addition to the foregoing list of chlorinated the distillation of water had ceased, the reaction mix- solvents, compound II may also be satisfactorily pre- ture was cooled and was successively treated with 5 per- pared from non-halogenated aromatic solvents, such as cent aqueous potassium hydroxide and 5 percent aque- paraxylene. While the solvent used may be at least par- 70 ous sodium sulfate solution. This treatment produced two tially dependent upon such factors as cost, toxicity and layers of liquid. The water layer was removed and the compatibility with the reaction equipment employed, it xylene solution was dried over sodium sulfate and was is preferable that the lower boiling point solvents be distilled at reduced pressure. Forty-two parts of an oily used, i.e., those boiling up to about 150 degrees centi- residue were isolated, which residue slowly crystallized. grade, so as to keep the reaction temperature low and Recrystaillization from 95 percent ethanol yielded white 3,392,214 5 6 needle-like crystals having a melting point of 105.5-106 to be stable on exposure to moist atmosphere, retaining degrees centigrade. appreciable elasticity after one month's exposure.

•For P3N3(OC6H6)4(NH2)2 (II).—Calculated, percent: These and the products of Examples 5-7 are useful Phosphorus, 17.2; carbon, 53.4; hydrogen, 4.5; nitrogen, construction, gasketing and covering materials in ma- 13.0. Found, percent: Phosphorus, 17.6; carbon, 53.6; hy- 5 chines and articles subjected to high temperatures and drogen, 4.4; nitrogen, 12.7. humidities. p , _ Various changes and modifications may be made in the mp method of this invention and in the products thereof. To a reaction vessel containing 135 parts of mono- Certain preferred forms have been described but equiva- benzene and equipped with water-cooled condenser were lents may be substituted without departing from the spirit charged 46 parts of compound I and 62 parts of phos- and scope of this invention, ph.orus pentachloride. The mixture was refluxed at about What is claimed is: 135 degrees centigrade for about 4 hours, with the evo- 1. Cyclotriphosphazatriene of the formula, lution of hydrogen chloride. The reaction mixture was A Y filtered and the clear liquid was distilled at a reduced 15 \ / pressure to yield 86 parts of yellow viscous oil consid- ^ \ ered to have the formula of compound IX. A N N A P p Example 3 / ^ / \ A N A To a reaction vessel containing 136 parts of mono- 20 . . ... chlorobenzene and equipped with a water cooled con- wherein A is selected from the group consisting of denser were charged 27 parts of the product of Exam- chlorine and phenoxy; and Y is se ected from the group pie 1 (II) and 22 parts of phosphorus pentachloride. consisting of—NH2, —N=PC13, —N—P(C6H50)3 The mixture was refluxed at about 135 degrees centi- 311 '' P V Y 1S grade until the evolution of hydrogen chloride ceased. 25 -NHp- , . ,, , , N Thereafter, the monochlorobenzene was removed by dis- 2; 2>2£6 " tetrachloro - 4,6 - di(tnchlorophosphazo) tillation at a pressure of about 50 millimeters of mer- cyclotriphosphazatriene. . cury and 135 degrees centigrade to yield 39 parts of a yel- 3" 2'2'4>6 ~ tetraphenoxy - 4,6 - diammocyclotnphos- low viscous oil considered to have the structure of com- pnazatriene. _ pound III 30 4- 2,2,4,6-tetraphenoxy - 4,6 - di(trichlorophosphazo) Analogous products are obtained when compounds I cyclotriphosphazatriene. and II, respectively, are reacted under the same condi- f 2'2'4'.6/ tetraPhe?°xy - 4=5 " di(tnphenylphospha- tions with equivalent molar proportions of triphenoxy 20(cyciotnphosphazatriene. _ . 6 A r e for phosphorus dichloride, (C6H50)3PC12, to form com- " P °? f preparing cyclotnphosp'hazatriene pounds XIII and VII, respectively. Likewise, under the 35 Products which comprises reacting at a temperature he- same conditions, the reaction of triphenylphosphorusdi- . ^ about degrees centigrade 4,6-diaminocyclophos- hazene w tb a chloride, (C6H6)3PC12 with compounds I and II, respec- P ! Phosphorua chloride selected from the tively, yields compounds XI and V, respectively, as ex- group consisting of phosphorus pentaehtoride, triphenoxy- emplified bv Example 4 phosphorusdiehlonde and tnphenylphosphorusdichloride 40 'and thereafter recovering the resulting product. Example 4 7. The process of claim 6 wherein the diaminocyclo- _ .. , . . . . , phosphazene is 4,6-diatninoperchlorocyclophosphazene. To a reaction vessel. containing 90 parts of mono- * / ,' f erein the phos- chlorobenzene and equipped with a water-cooled con- phoru 8 Ths echlorid ese s is accordinphosphorug 0 scIai pentachloridem 7 wh . denser were charged 13.4 parts of the product of Exam- 9 The ess a.ccordi t0 claim 6 where;n the 4;6_ Pm v, ( ^ ^ ?-lltS triphenylphosphorusdi- 45 diaminocyclophosphazene is reacted with an alkali metal chloride (C6H6)3PC12. The mixture was refluxed until phenate tQ form diamin0perphenylcyclophosphazene and the evolution of hydrogen chloride ceased Thereafter thereafter reacting the diaminoperphenylcyclophos- the monochlorobenzene was removed by distillation at phazene with a phosphorus chloride selected from the 135 degrees .centigrade and at a reduced pressure of about grou.p consisting of phosphorus pentachloride, triphen- 50 millimeters of mercury to yield 31 parts of a yellow 50 oxyphosphorusdichloride and triphenyJphosphorusdi- viscous oil considered to have the structure of com- chloride. pound V. 10. The process according to claim 9 wherein the Example 5 phosphorus chloride is phosphorus pentachloride. 1 Ten grams of the oily monomer of Example 3 was 5,5 J The process according to claim 9 wherein the phos- polymerized to a rubber polymer by heating it in a Phorus chloride is tnphenoxyphosphoms dichloride. sealed tube placed in a molten bath held at 300 de- _ . „ , grees centigrade for 4 hours. The rubber was very elas- Keterences Cited tic and remained stable on exposure to a moist at- UNITED STATES PATENTS mosphere, retaining appreciable elasticity after one 60 2,876,248 3/1959 Ratz et al. 260—461.303 month of such exposure. Differential thermal analysis 3,083,222 3/1963 Binder et al. 260—461.303 on the rubber showed no major change up to a tempera- 2,948,689 8/1960 Burg et al. 260 2 ture of about 415 degrees centigrade. 3^071^552 1/1963 Burg -I-II-III" 260—2 Example 6 FOREIGN PATENTS 00 Five grams of the oily monomer of Example 4 was 894,152 4/1962 Great Britain, polymerized to a useful resinous polymer by heating about OTHER REFERENCES 10 parts of it in a sealed tube placed in a molten bath-held at 400 degrees centigrade for 24 hours. <>77 et aL' Chem" Revlews> voL 62> l962> PP- 247~ „ 277. Example 7 Ten grams of the oily monomer of Example 2 was CHARLES B. PARKER, Primary Examiner. polymerized to a robber polymer by heating it in a BERNARD HELFIN, Examiner. sealed tube placed in a molten bath held at 300 degrees centigrade for 1 hour. The rubber resulting was found 73 B. M. EISEN, A. H. SUTTO, Assistant Examiners.