3,257,337 United States Patent Office Patented June 21, 1966

1. 2 Suitable for use in the preparation of polyurethane foams. 3,257,337 It is another object of the invention to provide highly fire PHOSPHORUS CONTAINING POLYURETHANE resistant polyurethane compositions that lend themselves Blaine O. Schoepfle,COMPOSTIONS Snyder, and Francis M. Kujawa,... " to use in a wide variety of applications by virtue of the Tonawanda, N.Y., assignors to Hooker Chemical Cor fact it is possible to control the catalytic activity of the poration, Niagara Falls, N.Y., a corporation of New composition, while retaining the excellent fire-retarding York properties. It is a further object of the invention to pro No Drawing. Fied Dec. 31, 1962, Ser. No. 248,275 vide compositions that are suitable for use in the prepara 18 Claims. (CI. 260-2.5) tion of fire-resistant polyurethane foams. Further objects O and advantages of the invention will become apparent This invention relates to fire resistant polyurethane com from the consideration of the following detailed specifica positions, and to the products produced therefrom. More tion. particularly, the invention relates to fire-resistant poly It has now been found that the objects of the invention urethane foams or cellular plastic products having a can be accomplished by incorporating in polyurethane phosphorus compound chemically combined therein. In 5 compositions not only the phosphorus acids of the previ still another aspect of the invention the polyurethane ously described invention but also a neutral phosphorus compositions contain both phosphorus and a halogen compound, of a type to be described hereinafter. It has atom. The invention also relates to polymeric materials been unexpectedly found that the incorporation of a containing phosphorus and optionally a halogen which neutral phosphorus compound reduces the catalytic are useful in the preparation of polyurethane composi 20 activity of the phosphorus acid, and thereby provides tions. greater control over the foaming characteristics of the The compositions of the invention are useful in the polyurethane composition while not adversely affecting preparation of foamed or cellular plastic products. The the fire-resistant characteristics thereof. By virtue of the polyurethane foams are useful as insulating materials in phosphorus content of the neutral compounds, it is also both cold and hot applications, such as in domestic 25 possible to reduce somewhat the proportion of phosphorus refrigerators and refrigerated vehicles, as well as in acids previously employed in polyurethane compositions, insulation for hot water or steam pipes, valves and the but yet retaining all the valuable properties of the earlier like. The polyurethane foams are also useful as core phosphorus-containing compositions and adding the addi materials between skins such as aluminum or steel or tional advantage of better control over the foaming char plastics of various types. The resulting sandwich-type 30 acteristics. The results obtained in accordance with the structures are well suited for use in such diverse fields as present invention are quite surprising in view of the teach the construction and insulation industries. ings of the prior art which suggest that it is advantageous Polyurethane compositions and particularly the foamed to avoid the use of neutral phosphorus compounds, such products that are fire resistant are becoming increasingly as the neutral phosphate esters, since these compounds important in industry. A fire-resistant polyurethane com 35 normally adversely affect many of the valuable properties position that has been particularly successful is described of polyurethane foams. It has also been found that the and claimed in co-pending application S.N. 15,516, filed use of the neutral phosphorus compounds of the inven March 17, 1960. In accordance with that invention, poly tion improves the mixing characteristics of the viscous urethane compositions are rendered fire resistant by incor components frequently used in the production of polyure porating therein a phosphorus acid, including partially 40 thane foams. For example, the compatability of the esterified phosphorus acids that contain at least one re foaming agent is improved. maining unesterified acid group. The use of such phos In accordance with the invention, there are provided phorus compounds not only provides excellent fire polyurethane. compositions having incorporated therein: resistance because of the phosphorus content imparted to (A) a phosphorus acid, and (B) a phosphorus compound the compositions, but also by virtue of the fact that the having the formula: phosphorus compounds are chemically reacted into the compositions and, therefore, cannot be lost from the com position by evaporation, leaching, and the like. The compositions have a permanent fire resistance. In addi wherein n is an integer from zero to one, n is an integer tion to providing this beneficial effect, the phosphorus acid 50 from zero to three, Y is oxygen or sulfur, and R is selected also serves as the catalyst for the reaction of the hydroxyl from the group consisting of alkyl, halogen substituted containing polymeric material and the polyisocyanate in alkyl, aralkyl, alkaryland aryl. The hydrocarbon radicals the preparation of the polyurethane composition. Hence, preferably contain from one to twenty carbon atoms. it is normally unnecessary to use an additional catalytic Compounds wherein the hydrocarbon radicals join to material. It has now been found that when sufficient 55 form a ring are also contemplated, such as phenyl ethylene phosphorus acid is incorporated into the polyurethane phosphite. The alkyl groups can be substituted with a compositions to effect the desired degree of fire resistance, mixture of halogen atoms, such as a mixture of chlorine the foamiable compositions "rise' too rapidly to properly and bromine atoms. serve the requirements of certain applications. Hence, More particularly, the polyurethane compositions of it becomes desirable that for certain applications, it is 60 the invention comprise (A) a hydroxyl-containing poly possible to reduce the catalytic activity in the polyurethane meric material having a hydroxyl number between 25 composition, while yet retaining the desired degree of fire and 900, (B) a phosphorus acid, (C) a neutral phosphorus resistance. Obviously, these conditions cannot be met compound of the type described in the preceding para by merely reducing the extent of incorporation of the graph and (D) an organic polyisocyanate. Generally an phosphorus acid in the polyurethane composition. extraneous foaming agent is incorporated in the composi Accordingly, it is an object of this invention to provide tion to promote foaming to an extent greater than that a fire-resistant polyurethane composition that is especially provided by the phosphorus acid. 3,257,337 3 . 4. The neutral phosphorus compounds that can be em- Methyl diphenyl phosphine oxide ployed in accordance with the invention include the Tris (chloropropyl) phosphine oxide, following compounds wherein R and Y are as defined 2-bromoethyl diphenyl phosphine oxide, Thirdhereinbefore: degree esters of phosphoric acid (tertiary phos- and the corresp ondinging sulfur cocompounds: ds: phates), 5 Trimethyl phosphine sulfide Y 2-bromoethyl diphenyl phosphine oxide; Ro-P-or third degree esters of phosphorous acid (tertiary phos d phites), R 0. RO-P-OR for example: () Trimethyl phosphate R Triethyl phosphate for example: TrilaurylEthyl dimethylphosphate phosphate 5 Estyri E. Triphenylphosphate Trilauryl phosphite Tricresyl phosphate Triphenyl phosphite Tribenzylphosphate Tribenzyl phosphite Phenyl ethylene phosphate 20 Phenyl ethylene phosphite Tris (3-chloroethyl) phosphate Phenyl dimethyl phosphite Tris (2,3-dichloropropyl) phosphate Benzyl dimethyl phosphite Tris (2,3-dibromopropyl) phosphate, Tris (3-chloroethyl)phosphite and the corresponding sulfur compounds such as: 25 Tris(2-bromoethyl)phosphite; Trimethylthionophosphate second degree esters of phosphonous acids (secondary Phenyl ethylene thionophosphate; phosphonites), second degree esters of phosphonic acid (secondary phos- RO-P-OR phonates), k Y 30 for example: Dimethyl methylphosphonite Diethyl pentylphosphonite for example: Diphenyl methylphosphonite Dimethyl methylphosphonate Dibenzyl methylphosphonite Diethyl methylphosphonate Dimethyl cresylphosphonite Diethyl pentylphosphonate Bis(chloropropyl) chloropropylphosphonite Dilauryl methylphosphonate Bis(bromopropyl) bromopropylphosphonite; Diphenyl methylphosphonate 40 first degree esters of secondary phosphine oxides (phos Dibenzyl methylphosphonate phinites), Diphenyl cresylphosphonate R-P-R Dimethyl cresylphosphonate () Bis(chloropropyl) chloropropylphosphonate R Bis(chloropropyl) propenyl-2-phosphonate, - 45 Bis(2,3-dibromopropyl) 2,3-dibromopropyl phosphonate, for example: Methyl dimethylphosphinite and the corresponding Sulfur compounds such as: dimeth Methyl diethylphosphinite yl methylthionophosphonate; first degree esters of phos Phenyl diphenylphosphinite phinic acids (phosphinates), 50 Methyl diphenylphosphinite Y Benzyl diphenylphosphinite R-E-R Chloropropyl bis(chloropropyl) phosphinite b 2,3-dibromopropyl diphenylphosphinite; R 55 tertiary phosphines, for example: Methyl dimethylphosphinate R-P-R,k Methyl diethylphosphinate Phenyl diphenylphosphinate for example: Benzyl diphenylphosphinate 60 Trimethyl phosphine Methyl diphenylphosphinate Triphenyl phosphine Chloropropyl bis(chloropropyl)phosphinate Tribenzyl phosphine Butyl 2-bromoethyl phenyl phosphinate, Methyl diphenyl phosphine and the corresponding sulfur compounds such as: methyl is Tris (chloropropyl)phosphine diethylthionophosphinate; tertiary phosphine ...E." 65 2-bromoethyl diphenyl phosphine. Y The term "phosphorus acids' as used in describing the | acidic phosphorus compounds of the invention include R-P-R not only the mineral acids such as phosphoric acid and R 70 those acids having direct carbon-to-phosphorus bonds such as the phosphonic and phosphinic acids, but also those for example: o partially esterified phosphorus acids which contain at Trimethyl phosphine oxide least one remaining unesterified acid group such as the Triphenyl phosphine oxide first and second degree esters of phosphoric acid and the Tribenzyl phosphine oxide 75 like. 8,257,387 5 6 Typical phosphorus acids that can be employed in the present invention include the following compounds where second degree esters of phosphoric acid (secondary phos in R is as defined hereinbefore: phates), phosphoric acid, O R O : r Ho--OH for example: OH Dibenzyl phosphoric acid phosphorous acid, Dimethyl phosphoric acid 0 Dibutyl phosphoric acid O Di(2-ethylhexyl) phosphoric acid Diphenyl phosphoric acid H--OHOH Methyl phenyl phosphoric acid hypophosphorous acid, 5 Phenyl benzyl phosphoric acid; first degree esters of phosphorous acid (primary phos O phites), O H--OHH. | 20 phosphonic acids, H--orOH o for example: Methyl phosphorous acid R--OH 25 Pentyl phosphorous acid OEI Phenyl phosphorous acid for example: Cresyl phosphorous acid Methylphosphonic acid Benzyl phosphorous acid; Hexylphosphonic acid second degree esters of phosphorous acid (secondary phos Phenylphosphonic acid 30 phites), Tolylphosphonic acid Benzylphosphonic acid O 2-phenylethylphosphonic acid; H--or phosphinic acids (secondary phosphonic acids), &R 35 may be used with a little more difficulty due to the fact O that they are very weak acids, for example: R-1-0 E. Dimethyl phosphorous acid (dimethyl phosphite) R Methylbutyl phosphorous acid 40 Diphenyl phosphorous acid Phenyl benzyl phosphorous acid for example: Dibenzyl phosphorous acid Dimethylphosphinic acid Methyl phenyl phosphorous acid; Methylhexylphosphinic acid Diphenylphosphinic acid first degree esters of phosphonic acid (primary phos Phenylnaphthylphosphinic acid phonates), Dibenzylphosphinic acid O Methylphenylphosphinic acid; R--OR phosphonous acids (H 50 for example: O Ethyl methylphosphonic acid R-p-on Methyl butylphosphonic acid H Phenyl phenylphosphonic acid Tolyl methylphosphonic acid for example: 5 5 Ethyl benzylphosphonic acid; 'Ethylphosphonous acid first degree esters of phosphonous acid (primary phos Phenylphosphonous acid phonites), Tolylphosphonous acid O Benzylphosphonous acid; 60 first degree esters of phosphoric acid (primary phos R- -OR phates), H can be used with a little more difficulty due to the fact that they are very weak acids, for example: o R 65 Methyl ethylphosphonous acid : i Methyl phenylphosphonous acid for example: Phenyl phenylphosphonous acid. In the preparation of the polyurethane compositions of Methyl phosphoric acid 70 the invention, it is preferred to use a hydroxyl-containing Butyl phosphoric acid polymeric material having a hydroxyl number between 2-ethyl hexyl phosphoric acid about 25 and about 900. Such a polymeric material can Phenyl phosphoric acid be a polyester, a polyether or mixtures thereof. Partic Cresyl phosphoric acid ularly suitable are mixtures of a polyester and a poly Benzyl phosphoric acid; 5 ether wherein the polyester portion comprises at least 25 3,257,337 7 8 percent of the mixture. Excellent results are obtainable ylol - 1,4,5,6 - tetrachloro - 7,7-difluorobicyclo - (2.2.1)- when less than 25 percent polyester is employed, but Sup 5-heptene. Similar compounds are disclosed in U.S. plementary additives are frequently required to render Patent 3,007,958. . such a foam self-extinguishing. It is especially preferred Where aromatic or bicyclo carboxylic compounds are in the present invention to use a mixture of polyester and used, aliphatic acids are sometimes incorporated into the polyether in the ratio of 25 to 75 parts polyester to 75 polyester resin. Adipic acid is generally preferred for to 25 parts of polyether. Generally, the hydroxyl-con this purpose, although other suitable acids may be used taining polymers of the invention have a molecular weight Such as Oxalic, malonic, succinic, glutaric, pimelic, suberic, in the range from 200 to about 4,000. aZelaic, etc. Unsaturated acids such as maleic, fumaric, The polyesters are the reaction products of a polyhydric O itaconic, citraconic, aconitic, etc., can also be used. alcohol and a polycarboxylic compound, said polycar The preferred polyesters of the present invention are boxylic compound being either a polycarboxylic acid, a those which contain an adduct of hexahalocyclopenta polycarboxylic acid anhydride, a polycarboxylic acid ester, diene co-reacted in the polyester portion in view of the a polycarboxylic acid halide or mixtures thereof. The fact that they contain a large amount of stable chlorine, carboxylic compounds can be aliphatic, cyclo aliphatic, 15 thereby enhancing the flame-retardant characteristics of aromatic, or heterocyclic and either saturated or unsat the resultant foam. Particularly preferred are those poly urated. Among the polycarboxylic compounds which can esters wherein the adduct is reacted in the polycarboxylic be used to form the polyester are: maleic acid; fumaric portion of the polyester, due to lower cost and commer acid; phthalic acid; isophthalic acid; terephthalic acid; cial availability of the polycarboxylic adducts of hexa tetrachlorophthalic acid; aliphatic acids such as oxalic, 20 halocyclopentadiene. malonic, succinic, glutaric and adipic; 1,4-cyclohexadi The polyethers employed are known in the art, and ene-1,2-dicarboxylic acid and the like. Additional poly are the reaction products of (1) either a polyhydric al carboxylic compounds which can be used to form the cohol, a polycarboxylic acid or a polyphenolic compound, polyester are Diels-Alder adducts of hexahalocyclopenta and (2) a monomeric 1,2-epoxide possessing a single 1,2- diene and a polycarboxylic compound, wherein the halo 25 epoxy group, Such as, for example, propylene oxide. The gen is selected from the group consisting of chlorine, polyhydric alcohols and polycarboxylic acids which may bromine, fluorine and mixtures thereof, for example: be employed are any of the polyhydric alcohols and poly 1,4,5,6,7,7-hexachlorobicyclo-(2.2.1)-5-heptene-2,3- carboxylic acids hereinbefore listed. Polyphenolic com dicarboxylic acid; pounds which can be employed are the reaction products 1,4,5,6-tetrachloro-7,7-difluorobicyclo-(2.2.1)-5- 30 of phenolic compounds with aldehydes, such as phenol heptene-2,3-dicarboxylic acid; formaldehyde resins. Examples of monomeric 1,2-epox 1,4,5,6,7,7-hexabromobicyclo-(2.2.1)-5-heptene-2,3- ides include ethylene oxide, propylene oxide, butylene dicarboxylic acid; oxide, isobutylene oxide, 2,3-epoxyhexane, 3-ethyl-2,3- 1,4,5,6-tetrabromo-7,7-difluorobicyclo-(2.2.1)-5- epoxyoctane, epichlorohydrin, epibromohydrin, styrene 35 Oxide, glycidyl ether, methyl glycidyl ether, phenyl gly heptene-2,3-dicarboxylic acid; cidyl ether, butyl glycidyl sulfide, glycidyl methyl sul and the like. Mixtures of any of the above polycarbox fone, glycidyl methacrylate, glycidyl acrylate, glycidyl ylic compounds can be employed. benzoate, glycidyl acetate, glycidyl octanoate, glycidyl In order to obtain a satisfactory rigid foam, at least a Sorbate, glycidyl allyl phthalate, and the like. The pre portion of the total polyhydric alcohol component should 40 ferred monoepoxides are the monoepoxide substituted consist of a polyhydric alcohol containing at least three hydrocarbons, the monoepoxy-substituted ethers, sulfides, hydroxyl groups. This is desired to provide a means for Sulfones and esters wherein the said compounds contain branching the polyester. Where an even more rigid struc no more than eighteen carbon atoms. A lower alkylene ture is desired, the whole alcohol component may be oxide is preferably employed in rigid foams as the higher made up of a trifunctional alcohol such as glycerol. 45 counterparts yield flexible rather than rigid products. Where a less rigid final product is desired, a difunctional A large number of various organic polyisocyanates can polyhydric alcohol such as ethylene glycol or 1,4-butane be used. Of the hydrocarbon polyisocyanates, the aryl diol may be utilized as that part of the polyhydric alco and alkary polyisocyanates of the benzene and naphtha hol component. Other glycols such as diethylene glycol, lene series are more reactive and less toxic than the triethylene glycol, propylene glycol, dipropylene glycol, aliphatic members. Consequently, the aromatic com other polypropylene glycols, butylene glycols, polybutyl pounds are preferred in the present invention. The pre ene glycols, and the like can also be used. Among the ferred compounds which are at present most readily polyhydric alcohols which can be used are glycerol, hex available commercially are 2,4-tolylene diisocyanate, 2,6- anetriol, butanetriol, trimethylol propane, trimethylol tolylene diisocyanate and mixtures thereof. However, ethane, pentaerythritol, mannitol, sorbitol, cyclohexane 55 others may be used, among them diol-1,4, glycerol monoethyl ether and the like. The ratio of the polyhydric alcohol such as glycerol to the poly Phenyl diisocyanate; basic acid can be expressed as the hydroxyl-carboxyl Alpha-naphthyl diisocyanate; ratio, which can be defined as the number of moles of 4-tolylene. diisocyanate; hydroxyl groups to the number of moles of carboxyl 60 n-Hexyl diisocyanate; groups in a given weight of resin. This ratio may be Methylene-bis-(4-phenyl isocyanate); varied over a wide range. Generally, however, a hydrox 3,3'-bitolylene-4,4'-diisocyanate; , yl-carboxyl ratio of between 1.5:1 to 5:1 is needed. 3,3'-dimethoxy-4,4'-biphenylene diisocyanate; Instead of employing a polycarboxylic compound which 1,5-naphthalene diisocyanate; is Diels-Alder adduct of hexahalocyclopentadiene and a 65 2,4-chlorophenyl diisocyanate; polycarboxylic compound, a polyhydric alcohol which is Hexamethylene diisocyanate; a Diels-Alder adduct of hexahalocyclopentadiene and a Ethylene diisocyanate; polyhydric alcohol can be used. This is done by employ Trimethylene diisocyanate; ing (A) a polyester resin comprised of the reaction prod 1,3-cyclopentylene diisocyanate; uct of (1) an adduct of hexahalocyclopentadiene and a 1,2-cyclohexylene diisocyanate; polyhydric alcohol containing aliphatic carbon-to-carbon 1,4-cyclohexylene diisocyanate; unsaturation, (2) a polycarboxylic compound and (3) a Cyclopentylidene diisocyanate; polyhydric alcohol containing at least three hydroxyl Cyclohexylidene diisocyanate; groups. Typical adducts include: 2,3-dimethylol-1,4,5,6, p-Phenylene diisocyanate; 7,7-hexachlorobicyclo-(2.2.1)-5-heptene; and 2,3-dimeth m-Phenylene diisocyanate; 3,257,337 9 O 4,4'-diphenyl propane diisocyanate; methylol phenols, formic acid and tetrahydroxy methyl 4,4'-diphenyl methane diisocyanate; phosphonium chloride. In addition, mixtures of the 1-methyl-2,4-phenylene diisocyanate; above foaming agents can be employed. 4,4'-diphenylene diisocyanate; In preparing the polyurethane compositions of this in 1,2-propylene diisocyanate; vention, the hydroxyl containing polymer and polyiso 1,2-butylene diisocyanate; cyanate are preferably reacted in a ratio sufficient to pro Ethylidene diisocyanate; vide about eighty-five to one hundred and fifteen percent Propylidene diisocyanate; of isocyanato groups with respect to the total number Butylidene diisocyanate; of hydroxyl and carboxyl groups present in the hydroxyl 1,3,5-benzene triisocyanate; O containing polymeric material (and the foaming agent, if 2,4,6-tolylene triisocyanate; one is provided). The reaction temperature generally 2,4,6-monochloro benzene triisocyanate; ranges from about twenty to about one hundred and 4,4',4'-triphenylmethane triisocyanate; twenty degrees centigrade, although higher and lower Polymethylene polyphenylisocyanate and mixtures there temperatures can be used. of. Higher isocyanates are provided by the liquid reaction The phosphorus acids of the invention are employed products of (1) diisocyanates and (2) polyols or poly in amounts from about 2 to 20 parts by weight per hun amines; etc. In addition, isothiocyanates and mixtures dred parts of hydroxyl-containing polymer. The pre of isocyanates may be employed. Also contemplated ferred amount is from about 4 to about 15 parts by are the many impure or crude polyisocyanates that are Weight per hundred of polymer. The neutral phosphorus commercially available, such as crude mixtures of methyl 20 compound of the invention is employed in amounts of at ene bis(4-phenylisocyanate). least about 0.5 part and preferably from about 1 to 15 Although not generally preferred when using the phos parts by Weight per hundred parts of the hydroxyl-con phorus acids, conventional reaction catalysts can also taining polymer. The preferred amount of the neutral be used in producing the polyurethane compositions. The phosphorus compound is from about 2 to about 10 parts catalyst employed can be any of the known conventional 25 by Weight per hundred parts polymer. It is preferred catalysts for isocyanate reactions, such as tertiary amines, to add the phosphorus compounds directly to the hy. for example, triethylamine, N-methyl morpholine, tri droxyl-containing polymer in order to reduce the vis ethanolamine, etc., or antimony compounds such as anti cosity, and Subsequently add the polyisocyanate and foam mony caprylate, antimony naphthenate, or antimonous ing agent; however, excellent results are obtainable when chloride. In addition, tin compounds can be employed 30 all the components are simultaneously mixed together, or such as dibutyltin dilaurate, tri-n-octyltin oxide, hexa When the phosphorus compound or compounds is pre butylditin, tributyltin phosphate, or stannic chloride. reacted with the isocyanate component. Rigid or flexible polyurethane foams are thereby obtained. Various additives can be incorporated which may serve The rigid polyurethane foams utilize a highly branched to provide different properties. For instance, antimony hydroxyl rich polyester or polyether having a hydroxyl 35 Oxide may be used to improve fire-resistance, fillers, such number of between about two hundred and nine hundred as clay, calcium sulfate or ammonium phosphate may and fifty. The flexible polyurethane foams utilize a linear be added to lower cost, and improve density and fire-re relatively hydroxyl poor polyester or polyether having sistance; ingredients such as dyes may be added for color, a hydroxyl number of between about thirty and one hun and fibrous glass, asbestos, or synthetic fibers may be dred. If a polyester or polyether with a hydroxyl num 40 added for strength. ber between about one hundred and two hundred is The following examples will serve to illustrate the pres employed, a semi-rigid polyurethane foam is usually ent invention, but are not intended to limit it. All parts obtained. are by Weight unless indicated otherwise. Any foaming agent commonly used in the art can be In these examples the foaming characteristics of a employed. Foaming agents in this art are generally those 45 number of compositions were examined to determine the materials that are capable of liberating gaseous products effect of employing the invention. Of principal concern when heated, or when reacted with an isocyanate. Prefer here is a property known as the “rise time” of the foam ably foaming is accomplished by introducing a low boil able composition. The “rise time' is defined as the time ing liquid into the catalyzed resin. The heat of reaction interval between deposition of the foamable mixture in is then sufficient to expand the mixture to a foam stable 50 the mold and the last detectible expansion of the mix enough to retain its shape until the resin gels. Suitable ture. The relative rise times of various foamable mix liquids are the fluorochlorocarbons boiling in the range tures is most readily determined in the laboratory by of twenty to fifty degrees centigrade, and mixtures there measuring the "tack-free time” of the foamable composi of, for example, tricholrofluoromethane, trichlorotrifluo tion. The "tack-free time' is defined as the time interval roethane, dichloromonofluoromethane, monchloroethane, 55 after deposition of the foamable mixture in the mold monochloromonofluoroethane, difluoromonochloroethane, that the foam is tacky to the touch. This measure of and difluorodichloroethane. the foaming characteristics of the foamable compositions Another foaming system that is suitable for carrying has been used in the following examples: out the foaming reaction at an elevated temperature is found in United States Patent 2,865,869, which discloses 60 Example 1 and claims the use of tertiary alcohols in the presence A mixture of hydroxyl-containing polymers was pre of strong, concentrated acid catalysts. Examples of ter pared by mixing the following components: tiary alcohols include: tertiary amyl alcohol; tertiary butyl alcohol; 2-methyl-3-butyn-2-ol; 1-methyl-1-phenyl 65 parts of a polyester containing two moles of trimeth ethanol; and 1,1,2,2-tetraphenylethanol, etc. Examples 65 ylol propane to one mole of 1,4,5,6,7,7-hexachlorobi of catalysts include: sulfuric acid; phosphoric acid; sul cyclo- (2.2.1) - 5-heptene-2,3-dicarboxylic anhydride, fonic acid; and aluminum chloride; etc. In addition, vari and having a hydroxyl number of about 400. ous secondary alcohols and glycols may be used as: 1 25 parts of a polyether comprised of the reaction product phenyl-1,2-ethanediol; 2-butanol; etc. Generally, sec of a phenol-formaldehyde resin and ethylene oxide, and ondary alcohols should be used with strong concentrated 70 having a hydroxyl number of about 350. acid catalysts as above; however, certain secondary al 5 parts of a mixture of about 50 percent mono (2-ethyl cohols may be used without the acid catalyst, e.g., acet hexyl) acid phosphate and about 50 percent di(2-ethyl aldol, chloral hydrate, etc. Other foaming agents that hexyl) acid phosphate. may be used include the following: polycarboxylic acids, 30 parts of trichlorofluoromethane. polycarboxylic acid anhydrides, dimethylol ureas, poly 75 To this composition was added 64 parts of a crude, com 3,257,337 2 mercial mixture of tolylene diisocyanate isomers, and 0.5 position was employed to make a polyurethane foam as part of a silicone-glycol copolymer cell controller (desig in Example 1. The tack-free time was measured and nated L-530 by the manufacturer, Union Carbide Corpo compared with that of a composition that was identical ration). The mixture was agitated vigorously for 40 Sec except for the omission of the tertiary phosphate. Fol onds and poured into a mold. A foam having a fine cell lowing are the tack-free times: structure resulted. The tack-free time was 5.5 minutes. Tack-free The foam was cured at 80 degrees centigrade in 10 min time (min.) utes. Composition with 2.5 parts tris(3-chloroethyl)phos Examples 1-7 phate ------4.25 In these examples, quantities of tris(3-chloroethyl) O Composition with no tris (8-chloroethyl) phos phosphate were incorporated into the mixture of hy phate. ------2.75 droxyl-containing polymer of Example 1 together with Examples 9-23 the same quantity of the acid phosphate mixture of Ex In Example 9, the procedure of Example 1 was re ample 1. The proportions of tris(8-chloroethyl)phos peated and the composition had a tack-free time of 6 phate ranged from 0.75 to 10 parts by weight of phosphate 5 minutes. Then a series of compositions were prepared perhundred parts of hydroxyl containing polymer. Poly in which all the components were the same as in Ex urethane foams were prepared from the compositions by ample 9 except that one of the following phosphorus the same procedure used in Example 1. The tack-free compounds was also incorporated into the composition: time was determined for each foam. In Some cases, the triethyl phosphite, tricresyl phosphate, bis(chloropropyl) compositions were foamed in large scale foaming ma 20 chloropropylphosphonate, phenyl ethylene phosphite, tri chines and the rise time for these foams was measured. phenyl phosphite, trimethyl thionophosphate, bis(2,3)-di The results are shown in Table 1, which also includes bromopropyl)2,3-dibromopropylphosphonate, and tris(2, the results from Example 1. 3-dibromopropyl) phosphate. The tack-free times of all

TABLE I 2-Ethylhexyl Tris(8-chloro Phosphate ethyl) Phos-Tack-free Rise Time IFire Retard Example No. (Parts/100 phate (Parts. ine (Secolds) ance 1 (Inclf parts polymer) 100 parts (Minutes) minute) polymer)

5 None 5.5 120 0.8 5 0.75 6.25 ------5 25 7.5 ------5 2.5 8.25 180 O. 6 5 5.0 7.5 175 0.4 5 7.5 8.25 ------5 10 9.0 ------

1 Determined by ASTM D-757-49.

TABLE 2 Neutral Phosphorus Compound Tack-free Eire Example No. Time Retardacc (PartSiiOO (Minutes) (inches?min.) Name parts polymer)

None------6.0 1.25 7.0 Triethyl phosphite.----...-- 2.5 7.5 5. O 8.0 Trieresyl phosphate------2.525 7.07.75 5.0 9.5 Bis(chloropropyl) chloro- 25 7.5 propyl phosphonate. 2.5 7.5 5.0 8.5 Plhenyl ethylene phosphite- 5. O 8.0 Triphenylphosphite.------5, 0. 9.5 Trimethylthionophosphate- 5. O 0.5 Bis(2,3-dibromopropyl) 2,3- 5. O 9.0 dibromopropyl phospho nate. 28------Tris(2,3-dibromopropyl) 5.0 8.5 0.9 phosphate.

The data in Table 1 show that when the concen the compositions were measured and the results are shown tration of the phosphorus acid in the polyurethane com 65 in Table 2 together with the results from Example 9. position is held constant, the foaming characteristics of The results in Table 2 show that additional compounds the compositions can be controlled by incorporating the of the invention can be used for controlling the foaming neutral phosphorus ester at selected levels. characteristics of polyurethane compositions. The foaming characteristics of polyurethane composi Example 8 70 tions containing the hydroxyl containing polymers set The hydroxyl-containing polymer of Example 1 was forth in the following Examples 24 to 30 are modified mixed with 10 parts by weight (per hundred parts of in a manner similar to that indicated in the foregoing polymer) of a mixture of about 50 percent monobutyl examples, when a phosphorus acid and a neutral phos acid phosphate and 50 percent dibutyl acid phosphate, phorus compound of the invention are incorporated and 2.5 parts of tri(6-chloroethyl) phosphate. The com- 75 therein. 3,257,337 13 14 7. The composition of claim 5 wherein the tertiary Example No. Hydroxyl-containing Polymer phosphate is tricresyl phosphate. 8. The composition of claim 5 wherein the tertiary 6 moles adipic acid. phosphate is trimethyl thionophosphate. 10 moles trimethylolpropane. 24------Acid number: less than 1. 9. The composition of claim 1 wherein the phosphorus Hydroxyl number: 504. compound (C) is a secondary phosphonate. 25------Molecular weight: about 2,000. 10. The composition of claim 9 wherein the secondary EaHydroxyl number: glycol. 56. 4 moles 1,4,5,6,7,7-hexachlorobicyclo-(2.2.1)-5- phosphonate is bis(chloropropyl) chloropropylphospho heptene-2,3-dicarboxylic acid. nate. 7.6 moles glycerol. 26.------2 moles adipic acid. O 11. The composition of claim 1 wherein the phos Acid number: 5. . phorus compound (C) is a tertiary phosphite. Hydroxyl number 265. 12. The composition of claim 11 wherein the tertiary .5 molesmoles glycerol.adipic acid. phosphite is triethylphosphite. Acid number: 1. Hydroxyl number: 640. 13. The composition of claim 1 wherein the phos 1 mole trimethylolpropane. 15 phorus acid is a mixture of monobutyl acid phosphate 28------6 moles propylene oxide. Hydroxyl number: 392. and dibutyl acid phosphate. 8.8 moles trimethylolpropane. 14. The composition of claim 1 wherein the phos 51 molemoles phthalic adipic acid. anhydride. . . phorus acid is a mixture of mono (2-ethylhexyl) acid Acid number: less than 1. phosphate and di(2-ethylhexyl) acid phosphate. 1Hydroxyl mole i,4,5,6,7,7-hexachlorobicyclo-(2.2.1)-5-heptene number: 435. 20 15. A process which comprises reacting (A) hydroxyl 2,3-dicarboxylic acid containing polymer having a hydroxyl member from 80------4 moles propylene oxide. Acid number: 0. about 25 to 900, (B) an organic polyisocyanate, and Hydroxyl number: 202. (C) a phosphorus acid having at least one unesterified acid group in a proportion from about 2 to 20 parts 25 by weight per hundred parts of hydroxyl-containing poly While the invention has been described with refer mer, in the presence of (D) a phosphorus compound hav ence to certain specific embodiments, it will be recog ing the following formula: nized by those skilled in the art that many variations are possible without departing from the spirit and scope of (Y). the invention. 30 (R)n-P-(OR)-in We claim: a wherein n is an integer from 0 to 1, n is an integer 1. A composition of matter comprising (A) a hy from 0 to 3, Y is selected from the group consisting of droxyl-containing polymer having a hydroxyl number oxygen and sulfur, R is selected from the group consist from 25 to 900, (B) a phosphorus acid which contains at ing of alkyl, halogen-substituted alkyl, aralkyl, alkaryl least one unesterified acid group in a proportion from 35 and aryl, in a proportion from about 1 to 15 parts by about 2 to 20 parts by weight per hundred parts of hy Weight per hundred parts of hydroxyl-containing poly droxyl-containing polymer, and (C) a neutral phosphorus mer, and (E) a foaming agent. compound having the following formula: 16. The process of claim 15 wherein the phosphorus compound (C) is tris (B-chloroethyl) phosphate. 40 17. The process of claim 15 wherein the phosphorus acid is a mixture of monobutyl acid phosphate and dibutyl wherein n is an integer from zero to one, m is an integer acid phosphate. from zero to three, Y is selected from the group consist 18. The process of claim 15 wherein the phosphorus ing of oxygen and sulfur, and R is selected from the acid is a mixture of mono (2-ethylhexyl) acid phosphate group consisting of alkyl, halogen-substituted alkyl, 45 and di(2-ethylhexyl) acid phosphate. aralkyl, alkaryl and aryl, in a proportion from about 1 to 15 parts by weight per hundred parts of hydroxyl References Cited by the Examiner containing polymer. UNITED STATES PATENTS 2. The composition of claim 1 wherein the hydroxyl 2,589,326 3/1952 Oberright ------260-461 XR containing polymer comprises a polyester comprised of 50 2,602,783 7/1952 Simon ------260-2.5 the reaction product of a polyhydric alcohol and a poly 2,794,821 6/1957 Loughran et al. ----- 260-461 carboxylic compound. - 3,034,996 5/1962 Kaplan ------260-2.5 3. The composition of claim 1 wherein the hydroxyl 3,061,625 10/1962 Friedman ------260-2.5 containing polymer comprises a mixture of a polyester 3,067,149 12/1962 Dombrow et al. 260-2.5 comprised of the reaction product of a polyhydric alcohol 55 3,075,928 1/1963 Lanham ------. 260-2.5 and a polycarboxylic compound, and a polyether com 3,100,752 8/1963 Dombrow------260-2.5 prised of the reaction product of a monomeric 12-epoxide 3,102,825 9/1963 Rogers et al. ------260-2.5 and a material selected from the group consisting of a 3,131,115 4/1964 Robitschek et al. 260-2.5 XR polyhydric alcohol, a polycarboxylic acid and a poly 3,134,742 5/1964 Wismer et al. ------260-2.5 phenolic compound. 60 4. The composition of claim 2 wherein the polycar FOREIGN PATENTS boxylic portion of said polyester contains an adduct of 598,678 1/1961 Belgium. hexahalocyclopentadiene and a polycarboxylic compound. 1,297,489 5/1962 France. 5. The composition of claim 1 wherein the phosphorus compound (C) is a tertiary phosphate. 65 LEON J. BERCOVITZ, Primary Examiner. 6. The composition of claim 5 wherein the tertiary DONALD E. CZAJA, Examiner. phosphate is tris(g-chloroethyl)phosphate. J. J. KLOCKO, Assistant Examiner.