Graft copolymers
Patton, Jr. et al.  
 1 GRAFT COPOLYMERS [75] Inventors: John T. Patton, Jr., Wyandotte;  
 Louis C. Pizzini, Trenton; William W. Levis, Jr., Wyandotte; Bernard A. Merkl, Detroit, all of Mich.  
 [731 Assignee: BASF Wyandotte Corporation,  
 Wyandotte, Mich.  
 [221 Filed: Oct. 15, 1973 [21] Appl. No.: 406,534  
 152} U.S. Cl 260/869, 260/859 R, 260/870, 260/874, 260/899, 260/961 [51] Int. Cl. C08f&#39;21/00 [58] Field of Search 260/869. 870, 874, 899, 260/961, 80 PS, 859 R, 80.71, 87.5 R, 87.7, 836, 837 R, 857 G [56] References Cited UNITED STATES PATENTS 9/1958 Bcamzm 260/45.4  
 1 Apr. 1, 1975 3.163.627 12/1964 Craver 260/861 3,175,998 3/1965 Rabinowitz 260/85.5 3,210,442 10/1965 Lundberg et a1. 260/869 3,577,480 5/1971 Thorpe 260/869 3.641.202 2/1972 Biranowski et a1. 260/869 3,726,839 4/1973 Jin 260/78.5 CL  
 Primary E.\&#39;atninet-Morris Liebman Assistant E.\&#39;aminerE. A. Nielsen Attorney, Agent, or Firm-Joseph D. Michaels; Bernhard R. Swick; Robert E. Dunn [57] ABSTRACT Graft copolymers are prepared by the in situ polymerization of phosphorus or phosphorus and halogen containing monomers in the presence of a free radical catalyst in a polyol containing from about 1.0 to about 2.5 moles of unsaturated per mole of polyol.  
 8 Claims, No Drawings BACKGROUND OF THE lNVEN &#39;llON I l. l-&#39;ield ofthe Invention The present ittvention relates to graft copolytner dis persions which ntay be used to prepare urethane&#39;compositions having fire-retardant properties. More particularly. the ittvention relates to graft copolynter dispersions prepared by the in situ polymerization of mononters or tttixtures of monomers containing phosphorus or phosphorus and halogen with art uttsaturated polyol itt tlte presettce of a free radical catalyst.  
 1. Prior Art (iraft copolymer dispersions prepared front vinyl monomers attd polyether polyols are well knownin the art as evidenced by US. Pat. No. 3,383.35] to Stambergcr and US. Pat. No. 3,652,639 to Pizzini et al.  
 SUMMARY Ol&#34; &#39;l&#39;HF. lNVliN&#39;l&#39;lON ln accordattce with the present ittventiott. graft copolymer dispersions are prepared by the in situ polymerilation of vinyl monomers containing either phospltorus or phosphorus attd ltalogen. or botlt. in a polyol having front about l.t) to about 2.5 moles of unsaturation p&#39;cr ntole of polyol. hereinafter referred to as unsaturated polyol.&#34;  
  l&#39;he graft copolymer dispersions are obtained by the simultaneous grafting of a monomer or mixture of monomers. contaitting either phosphorus or phosphorus and halogen in the presence of a free radical catalyst on to an unsaturated polyol at a temperature above which the free radical catalyst decomposes.  
  &#39;l&#39;his catalyst tentperature range is front about 70 C. to about 170 (1. preferably betweett I05 C. and I3. The products prepared by this procedure exhibit a relatively low viscosity attd can be used to prepare ure thane compositions having fire-retardant properties.  
 DHSCRIP&#39;IION ()l &#39;l&#39;Hli PREFERRED l-IMBODIMHNIS &#39;lhe unsaturated polyols etttployed in the present itivetttion may be prepared by the reaction of any convetttiottal polyol with an orgattic compound having botlt etltylcnic uttsatttratiott and a ltydroxyl. carboxyl. or epoxy group or they may be prepared by employing an organic compound having both ethylenic unsaturatiott attd a hydroxyl. carboxyl. or epoxy group as a reactant in the preparation of the polyol. Representative of suclt orgattic compounds include unsaturated polycarboxylic acids and anhydrides such as malcic acid and anltydride. futttaric acid attd anltydride. crotonie acid attd anltydride. propenyl succittic anhydt&#39;ide. and halogenated tttaleic acids and attltydrides. unsaturated polyhydt&#39;ic alcohols such as Z-butene-l.4-diol. glycerol allyl&#39;ether. tritnetltylolallylether. pentaerytltritol allylether. pentaerythritol vinylether. pentaerythritol diallyletlter. attd l-butene-3.4-diol. unsatttrated epoxidcs such as l-vinylcyclohexane-3.4-epoxidc. butadicite monoxide. vinyl glycidylethert l-vinyloxy-2.3- epoxy propane). glycidyl methacrylate attd 3-allyloxypropylene oxide (allyl glycidylether). If a polyearboxylic acid or attltydride is etnployed to incorporate un saturation ittto the polyols. it is then necessary to react the unsaturated polyol with an alkylene oxide. prefera hl clltylclte or propylene oxide. to replace the earlyoxyl groups with hydroxyl groups prior to employ ntcitt in the present invention. The amount of alkylene oxide employed is such to reduce the acid nutnber of the unsaturated polyol to about one or less. Representative polyols which may be employed in the present invention are well known iii the art. &#39;l&#39;hey are often prcpared by the catalytic condensation of an alkylene oxide or mixture of alkylene oxides either simultaneously or sequentially with an organic compottnd hav ing at least two active hydrogen atoms such as evidenced by US. Pat. Nos. l.)22.45l. 3.l9().927 and 3.346.557.  
  Representative polyols include polyhydroxylcontaining polyesters. polyalkylene polyether polyols. polyhydroxyterminated polyurethane polymers, polyhydroxyl-containing phosphorus compounds. and alkylene oxide adducts of polyhydric polythioethers. polyacetals. aliphatic polyols and tltiols. ammonia. attd antines including aromatic. aliphatic. attd heterocyelic amines. as well as mixtures thereof. Alkylene oxide adducts of compounds which contain two or ntore differ ettt groups within the above-defined clas. s may also he ttsed such as atttino alcohols which contain an atttitto group and a hydroxyl group Also alkylene oxide adducts of contpounds which contain one -SH group and one -()H group as well as those which contain an atnino group attd a SH group may be used.  
  Atty suitable hydroxylcontaining polyester may be used such as are obtained front polycarboxylic acids attd polyhydric alcohols. Atty suitable polycarlmxylic acid maybe used such as oxalic acid. tnalonie acid. suecinic acid. glutaric acid. adipic acid. pimelic acid. suberic acid. azelaic acid. sebacic acid. brassylic acid. tltapsic acid. ntaleic acid. t&#39;umaric acid. glutaconic acid. u-hydromuconic acid. fi-hydromuconic acid. a-butyl-u-ethyl-glutarie acid. a-fidiethylsuccittic acid. isophthalic acid. terephthalic acid. ltetnimellitic acid. and l.4cyclohexane-dicarboxylic acid. Any suitable polyltydrie alcohol including botlt aliphatic and aromatic may be used such as ethylene glycol. 1.3- propylene glycol. l.Z-propylene glycol. l.4-butylene glycol. l.3-butylenc glycol. l.Z-butylene glycol. l.5- pentane diol. l.4-pentane diol. l.3-pentane diol. l.6- hexane diol. l.7-heptane diol. glycerol. l.l.ltrimetltylolpropane. l.l.l-tritnetltyloletltanc. hexanel.Z.6-triol. (v-methyl glueoside. pentaerytln&#39;itol. and sorbitol. Also included with the ternt polyhydric alcohol are compounds derived front phenol such as 2.2- t4.4hydroxyphenol)propane. eottnnonly known as liisphenol A.  
  Any suitable polyalkylene polyether polyol may be used such as the polymerization product of an alkylene oxide or of art alkylene oxide with a polyltydric alcohol having frottt Z to 6 hydroxyl groups. Atty suitable holyhydric alcohol may be used such as those disclosed above for use iii the preparation of the hydroxylcontaining polyesters. Any suitable alkylene oxide may be used such as ethylene oxide. propylene oxide. butylene oxide. atttylene oxide. attd hetcric or block copolytiters of these oxides. The polyalkylene polyether polyols may be prepared frotti other starting materials such as tctrahydrofuran and allxylenc oxidetetrahydrofuran copolymers&#39;. epihalohydrins such as epichlorohydrin; as well as arallvylene oxides suclt as styrene oxide. The polyallvylene polyetlter polyols may have either pritttary or secondary ltydroxyl groups and. preferably. are polyetlters prepared from alkylene oxides having front two to six carbon atoms sttelt as polyethylene ether glyeols. polypropylene ether glyeols. and polybtttylene ether glycols. The polyalkylene polyether polyols may be prepared by any known process such as, for example, the process disclosed by Wurtz in 1859 and Encyclopedia of Chemical Technology, Vol. 7, pp. 25 7262, published by lnterscience Publishers, Inc. (1951 or in U.S. Pat. No. 1,922,459. Polyethers which are preferred include the alkylene oxide addition products of trimethylolpropane, glycerine, pentaerythritol, sucrose, sorbitol, propylene glycol, and 2,2-(4,4-hydroxyphenyl)propane and blends thereof having equivalent weights of from 250 to 5,000.  
  Suitable polyhydric polythioethers which may be condensed with alkylene oxides include the condensation product of thiodiglycol or the reaction product of a dihydric alcohol such as is disclosed above for the preparation of the hydroxyl-containing polyesters with any other suitable thioether glycol.  
  The hydroxyl-containing polyester may also be a polyester amide such as is obtained by including some amine or amino alcohol in the reactants for the preparation of the polyesters. Thus, polyester amides may be obtained by condensing an amino alcohol such as ethanolamine with the polycarboxylic acids set forth above or they may be made using the same components that make up the hydroxyl-containing polyester with only a portion of the components being a diamine such as ethylene diamine.  
  Polyhydroxyl-containing phosphorus compounds which may be used include those compounds disclosed in U.S. Pat. No. 3,639,542. Preferred polyhydroxylcontaining phosphorus compounds are prepared from alkylene oxides and acids of phosphorus having a P equivalency of from about 72 percent to about 95 percent.  
 Suitable polyacetals which may be condensed with alkylene oxides include the reaction product of formaldehyde or other suitable aldehyde with a dihydric alcohol or an alkylene oxide such as those disclosed above.  
  Suitable aliphatic thiols which may be condensed with alkylene oxides include alkane thiols containing at least two SH groups such as l,2-ethane dithiol, 1,2- propane dithiol, 1,3-propane dithiol, and 1,6-hexane dithiol; alkene thiols such as 2-butene-l,4-dithiol; and alkyne thiols such as 3-hexyne-l,6-dithiol.  
  Suitable amines which may be condensed with alkylene oxides include aromatic amines such as aniline, ochloroaniline, p-amine aniline, 1,5-diamino naphthalene, methylene dianiline, the condensation products of aniline and formaldehyde, and 2,4-diamine toluene; ali  
 phatic amines such as methyl amine, triisopropanol amine, ethylene diamine, 1,3-propylene diamine, 1,4- butylene diamine, and l,3-butylene diamine.  
  As mentioned above, in order to introduce the necessary unsaturated groups into the polyols useful as starting materials in the present invention, the organic compound having both ethylenic unsaturation and a hydroxyl, carhoxyl, or epoxy group may be included in the polyol-forming reaction mixture or the unsaturation is introduced by reacting a conventional polyol with said organic compound. To prepare the unsaturated polyols of use in the present invention, from about l.O mole to about 2.5 moles, preferably from 1.5 moles to 2.5 moles, of said organic compound per mole of polyol is employed. The preparation of the unsaturated polyols employed in the present invention follows conventional prior art procedures such as disclosed in U.S. Pat. No. 3,275,606 and U.S. Pat. No. 3,280,077.  
 Generally, this requires a reaction at a temperature between 0 C. and l30 C. Both acidic catalysts, such as Lewis acid catalysts and basic catalysts such as alkali metal hydroxides, may be used. In addition, a noncatalyzed reaction may be used employing temperatures between 50 C. and 200 C.  
  As mentioned above, the graft copolymers of the invention are prepared by the in situ polymerization of the above-described unsaturated polyols with an ethylenically unsaturated monomers, at least one containing phosphorus or halogen. Whenever acrylonitrile is employed however, the mixture of monomers does not exceed 50 percent acrylonitrile based on the total mixture of monomers employed. Representative ethylenically unsaturated monomers which may be employed in the present invention include butadiene, isoprene, 1,4- pentadiene, l,6-hexadiene, l,7-octadiene, styrene, a-methylstyrene, 2,4-dimethylstyrene, ethylstyrene,  
 isopropylstyrene, butylstyrene, phenylstyrene, methyl-- styrene, cyclohexylstyrene, benzylstyrene, and the like; substituted styrenes such as chlorostyrene, 2,5- dichlorostyrene, bromostyrene, fluorostyrene, trifluoromethylstyrene, iodostyrene, cyanostyrene, methyl 4-vinylbenzoate, phenoxystyrene, p-vinyl diphenyl sulfide, p-vinylphenyl phenyl oxide, and the like; the acrylic and substituted acrylic monomers such as acrylonitrile, acrylic acid, methacrylic acid, methylacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, methyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, isopropyl methacrylate, octyl methacrylate, methacrylonitrile, methyl a-chloroacrylate, ethyl a-ethoxyacrylate, methyl a-acetaminoacrylate, butyl acrylate, Z-ethylhexylacrylate, phenyl acrylate, phenyl methacrylate, a-chloroacrylonitrile, N,N-dimethylacrylamide, N,N- dibenzylacrylamide, N-butylacrylamide, methacrylyl formamide, and the like; the vinyl esters, vinyl ethers, vinyl ketones, etc., such as vinyl acetate, vinyl chloroacetate, vinyl alcohol, vinyl butyrate, isopropenyl acetate, vinyl formate, vinyl acrylate, vinyl methacrylate, vinyl methoxy acetate, vinyl benzoate, vinyl iodide, vinyl toluene, vinyl naphthalene, vinyl bromide, vinyl fluoride, vinylidene bromide, l-chloro-l-fluoroethylene, vinylidcne fluoride, vinyl methyl ether, vinyl ethyl ether, vinyl propyl ethers, vinyl butyl ethers, vinyl 2-ethylhexyl ether, vinyl phenyl ether, vinyl 2- methoxyethyl ether, methoxybutadiene, vinyl 2- butoxyethyl ether, 3,4-dihydro-l ,2-pyran, 2-butoxy2&#39;- vinyloxy diethyl ether, vinyl 2-ethylmercaptoethyl ether, vinyl methyl ketone, vinyl ethyl ketone, vinyl phosphonates such as bis(B-chloroethyl)vinyl phosphonate, vinyl phenyl ketone, vinyl ethyl sulfide, vinyl ethyl sulfone, N-methyl-N-vinyl acetamide, N-vinylpyrrolidone, vinyl imidazole, divinyl sulfide, divinyl sulfoxide, divinyl sulfone, sodium vinyl sulfonate, methyl vinyl sulfonate, N-vinyl pyrrole, and the like; dimethyl fumarate, dimethyl maleate, maleic acid, crotonie acid, fumaric acid, itaconic acid, monomethyl itaconate, tbutylaminoethyl methacrylate, dimethylaminoethyl methacrylate, glycidyl acrylate, allyl alcohol, glycol monoesters of itaconic acid, dichlorobutadiene, vinyl pyridine, and the like. Any of the known polymerizable monomers can be used and the compounds listed above are illustrative and not restrictive of the monomers suitable for use in this invention.  
  The amount of ethylenically unsaturated monomer employed in the polymerization reaction is generally from 1 to 50 percent, preferably from 2 to 40 percent, based on the weight of the unsaturated polyol. The polymerization occurs by simultaneously adding at a steady or constant rate the monomer and a free radical catalyst to the unsaturated polyol at a temperature between about 80 C. and 175 C. to 135 C. Optionally, the catalyst may be dispersed in a portion of the polyol and thereafter added along with the monomer to the remaining portion of the unsaturated polyol.  
  The concentration of the catalyst is also a critical aspect of the present invention and can vary from about 0.5 percent to about percent, preferably from about 1 percent to about 5 percent by weight based on the weight of the monomer.  
  Illustrative catalysts are the well-known free radical type of vinyl polymerization catalysts, for example, the peroxides, persulfates, perborates, percarbonates, azo compounds, etc., including hydrogen peroxide, dibenzoyl peroxide, acetyl peroxide, benzoyl hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, butyryl peroxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide, paramenthane hydroperoxide, diacetyl peroxide, di-a-cumyl peroxide, dipropyl peroxide, diisopropyl peroxide, isopropyl-tbutyl peroxide, butyl-t-butyl peroxide, dilauroyl peroxide, difuroyl peroxide, ditriphenylmethyl peroxide, bis- (p-methoxybenzoyl )peroxide, p-monomethoxybenzoyl peroxide, rubrene peroxide, ascaridol, t-butyl peroxybenzoate, dicthyl peroxyterephthalate, propyl hydroperoxide, isopropyl hydroperoxide, n-butyl hydroperoxide, t-butyl hydroperoxide, cyclohexyl hydroperoxide, trans-Decalin hydroperoxide, a-methylbenzyl hydroperoxide, a-methyl-a-ethyl benzyl hydroperoxide, Tctralin hydroperoxide, triphenylmethyl hydroperoxide, diphenylmethyl hydroperoxide, a-a-azo-Z methyl butyronitrile, a,01&#39;-2-methyl heptonitrile, 1,1 -azo-lcyclohcxane carbonitrile, dimethyl a,a-azoisobutyratc, 4,4&#39;-azo-4-cyanopentanoie acid, azobis- (isobutyronitrile persuccinic acid, diisopropyl peroxy dicarbonate, and the like; a mixture of catalysts may also be used. Azobis (isobutyronitrile) is the preferred catalyst.  
  In a preferred embodiment of the present invention, from 2 to 40 percent by weight of bis(B-ch1oroethyl) vinyl phosphonate, and from 2 to 40 percent by weight vinylidene chloride based on the weight of the unsaturated polyol is polymerized in an unsaturated polyol in the presence of from 1 to 5 percent by weight of azobis-isobutyronitrile based on the weight of the polyol at a temperature between 105 C. to 135 C. The resulting product had a hydroxyl number of 43.0 and contained 2.3 percent phosphorus and 6.6 percent chlorine and a Brookficld viscosity at C. of 2275 centipoises.  
  In still another preferred embodiment of the present invention, the foregoing graft copolymer dispersions are employed in the preparation of polyurethane compositions, particularly polyurethane foams. The resulting polyurethane products exhibit marked improvements in fire-retardant properties without substantial impairment of the other physical properties of the products. The polyurethane products are generally prepared by the reaction of the graft copolymer disper sions with an organic polyisocyanate, optionally in the presence of additional polyhydroxyl-containing components, chain-extending agents, catalysts, surfaceactive agents, stabilizers, blowing agents, fillers and pigments. Suitable processes for the preparation of cellular polyurethane plastics are disclosed in US. Reissue Pat. No. 24,514 together with suitable machinery to be used in conjunction therewith. When water is added as the blowing agent, corresponding quantities of excess isocyanate to react with the water and produce carbon dioxide may be used. It is also possible to proceed with the preparation of the polyurethane plastics by a prepolymer technique wherein an excess of organic polyisocyanate is reacted in a first step with the polyol of the present invention to prepare a prepolymer having free isocyanate groups which is then reacted in a second step with water to prepare a foam. Alternately, the components may be reacted in a single working step commonly known as the one-shot&#34; technique of preparing polyurethanes. Furthermore, instead of water, low boiling hydrocarbons such as pentane, hexane, heptane, pentene, and heptene; azo compounds such as azohexahydrobenzodinitrile; halogenated hydrocarbons such as dichlorodifuoromethane, trichlorofluoromethane, dichlorodifluoroethane, vinylidene chloride, and methylene chloride may be used as blowing agents.  
  Organic polyisocyanates which may be employed include aromatic, aliphatic, and cycloaliphatic polyisocyanates and combinations thereof. Representative of these types are the diisocyanates such as m-phenylene diisocyanate, tolylene-Z,4-diisocyanate, tolylene-2,6- diisocyanate, tetramethylene-l ,4-diisocyanate, cyclohexane-l,4-diisocyanate, hexahydrotolylene diisocyanate (and isomers), naphthylene-l ,5- diisocyanate, 1-methoxyphenyl-2,4-diisocyanate, dipheny1methane-4,4-diisocyanate, 4,4-biphenylene diisocyanate, 3,3&#39;-dimethoxy-4,4&#39;-bipheny1 diisocyanate, 3,3-dimethyl-4,4-biphenyl diisocyanate, and 3,3- dimethyldiphenylmethane-4,4-diisocyanate; the triisocyanates such as 4,4,4-triphenylmethane triisocyanate, polymethylene polyphenylisocyanate and tolylene 2,4,6-triisocyanate; and the tetraisocyanates such as 4,4&#39;dimethyldiphenylmethane-2,2,5,5- tetraisocyanate. Especially useful due to their availability and properties are tolylene diisocyanate, diphenylmethane-4,4&#39;-diisocyanate and polymethylene polyphenylisocyanate.  
  Crude polyisoeyanate may also be used in the compositions of the present invention, such as crude toluene diisocyanate obtained by the phosgenation of a mixture of toluene diamines or crude diphenylmethane isocyanate obtained by the phosgenation of crude diphenylmethyl diamine. The preferred unreacted or crude isocyanates are disclosed in US. Pat. No. 3,215,652.  
  As mentioned above, the graft copolymer dispersions are preferably employed along with another polyhydroxyl-containing component commonly employed in the art. Any of the polyhydroxyl-containing components which are described above for use in the preparation of the graft copolymer dispersions of the present invention may be employed along with the unsaturated polyols in the preparation of the polyurethane compositions of the present invention.  
  Chain-extending agents which may be employed in the preparation of the polyurethane compositions of the present invention include those compounds having at least two functional groups bearing active hydrogen atoms such as water, hydrazine, primary and secondary diamines, amino alcohols, amino acids, hydroxy acids, glycols, ormixtures thereof. A preferred group of clniin-extending agents includes water and primary and secondary diamines which react more readily with the prepolymer than does water such as phenylene diamine l.4-cyclohexane-bis-t methylamine ethylene diaminc. N.N&#39;-di(2-hydroxypropyl)ethylene diamine. pipcrazine. 2-methylpiperazine. morpholine. and dodecahydro-1.-1.7.9b-tetraazaphenalene.  
  Any suitable catalyst may be used including tertiary amines. such as for example. triethylene diamine. N- methyl morpholine. N-ethyl morpholinc. diethyl ethanolaminc. N-coco morpholine. 1 -methyl--1- dimethylamino ethyl piperazine. BaneIhoxy-N ditnethyl propyl amine. N-dimethyl-N&#39;-methyl isopropyl propylene diaminc. N.N-diethyl-3-diethyl amino propyl amine. dimethyl benzyl amine. and the like. Other suitable catalysts are. for example. tin compounds such as stannous chloride. tin salts of carboxylic acids. such as dibutyltin di-2-ethy1 hexoate. tin alcoholates such as stannous octoate. as well as other organometallic compounds such as are disclosed in US. Pat. No. 2.846.408.  
  A wetting agent or surface-active agent is generally necess ry for production of high grade polyurethane foam according to the present invention. since in the absence of satne the foams collapse or contain very large &#39;uneven cells. Numerous wetting agents have been found satisfactory. Nonionic surfactants and wetting agents are preferred. Of these. the nonionic surfaceactive agents prepared by the sequential addition of propylene oxide and then ethylene oxide to propylene glycol and the solid or liquid organosilicones have been found particularly desirable. Other surface-active agents which are operative. although not preferred. ineludepolyethylene glycol ethers of long chain alcohols. tertiary amine or alkylolamine salts of long chain alkyl acid sulfate esters. alkyl sulfonic esters. and alkyl arylsulfonic acids.  
  The following examples illustrate the nature of the invention. All parts are by weight unless otherwise stated.  
 EXAMPLE l A. Preparation of an Unsaturated Polyether-lister Poly-o1 A clean. dry. nitrogen-tilled stainless steel reactor equipped with a thermometer. stirrer. nitrogen source inlet means and heat exchange means was charged with 484 pounds of a 3.000 molecular weight polyol prepared by the condensation of propylene oxide with glycerol in the presence of potassium hydroxide (7 percent by weight based on glyceroll. The reactor was heated to 103 C.. stripped for .2 hour at 10 mm. Hg pressure, the reactor was cooled to approximately C. and 24 pounds of maleic anhydride was charged. The reactor was sealed. evacuated to 10 tnln. Hg pressure or less. the agitator was turned on and the \acuum was checked. The vacuum was then relieved with nitrogen and pressured to nun. Hg. The reactor was again evacuated to 10 nnn. Hg or less. The reactor was then heated to 175 C. Propylene oxide. -12 pounds. was added as fast as possible during the heating period. l&#39;he reaction mixture was stirred for 11 hours at 175 C. After completing the reaction. the reactor was cooled to C.. and the product was stripped for 1 hour at 10 mm. Hg pressure or less. The product. a clear colored liquid. had a Brookfield viscosity at 25C. of 1200 eentipoises. a hydroxyl number of 54 and contained about 1.4 to 1.5 moles of maleic anhydride per 3.200 parts of polyol.  
 B. Preparation of a Transparent (iraft Copolymer reaction flask equipped with a stirrer. thermometer. reflux condenser. nitrogen inlet and two calibrated addition funnels was charged with 200 g. of the unsaturated polyol prepared above. The reaction flask was flushed with nitrogen and heated to 125C. with stirring under a slight nitrogen flow. While stirring under a slight nitrogen 1low.4(w.(\ g. of histB-chloroethyl) vinyl phosphonate was added at a steady rate over 65 minutes. Simultaneously. a slurry of4.7 g. oft YAZO) azohist isobutyronitrile) in 135 g. of the unsaturated polyol were then added to the reactor in a steady rate over 92 minutes. The reaction mixture was stirred at C. for -10 minutes and then stripped for V; hour at 120C. The product was a clear. yellow liquid having a Brookfield viscosity of 12.000 centipoises at 25C.. hydroxyl num- Iver-17.8. phosphorus content of 1.7 percent and a chlorine content of 3.6 percent.  
 EXAMPLE 11 A one-liter reaction flask equipped with a stirrer. thermometer. water-cooled retlux condenser. nitrogen inlet. and two laboratory pumps used for metering the monomer and the (YAKO) alo-bistisoluityronitrilcl streams was charged with .130 g. of unsaturated polyol. prepared as described in lixample l. L&#39;pon tlushing the reactor well with nitrogen. at steady and continuous addition of a mixture of5t\.2 g. of bistfi-chloroethyl1 vinyl phosphonate and 26.0 g. of styrene in one stream and a suspension of 4.0 g. of t\&#39;.-\7.()l a7.ohistisolnityronitrilel in 16-1 g. of the abovedeseribed unsaturated polyol in a second stream was made to the reactor at a temperature of &#34;C. to C. The monomer stream was added over a period of 45 to 60 minutes to the reactor while the \&#39;.-\7.() stream was added over a period of S to 15 minutes longer than the monomer stream. L&#39;pon the completion of the addition of the YAZO stream. the reaction mixture was maintained for one hour at 125C. to 130C. The reaction mixture was then stripped for one hour at 120C. to 130 C. at 10 mm. Hg to remove all volatiles. &#39;lhe product had the following properties: a hydroxyl number of about 4 a Brookfield viscosity at 25C. of about 3.000 cps. a phosphorus content of 1.4 percent and a chlorine content of 2.9-1 percent.  
 EXAMPLE 111 A one liter reaction flask equipped with a stirrer, thermometer. w ater-cooled reflux condenser. nitrogen inlet. and two laboratory pumps used for metering the monomer and the (YAZO) ayo-histisobutyronitrilel streams was charged with 19-1 g. of unsaturated polyol. prepared as described in Example 1. Upon flushing the reactor with nitrogen. at steady and continuous addition w as made to the reactor of a mixture of5t\.2 g. ofbis(/3- chloroethyll vinyl phosphonate and 2.8 g. of vinylidene chloride concurrently with a suspension of 7.7 g. of t\&#39;.-\7.()l a&#39;zo-bistisobutyronitrile) in 300 g. of the unsaturated polyol described in Example 1. The temperature throughout the addition was maintained at 1 25C. to 130C. The monomer stream was added over a period of -15 to at) minutes while the YAZO stream took about 8 to 15 minutes longer. L&#39;pon the completion of the addition of the \&#39;.-\7.0 stream. the reaction move all volatilesfil&#39;he&#39;iresulting product had a hydroxyl.  
 llLllllbCTUk&#39;l-bj a Brookl iel&#39;d viscosity at 25Cz-ofl2-100&#39; eentipoises: and-contained about .1 .3 percent phosphorus-and 6.1 percent chlorine.  
 EXAMPLE IV A one-liter reaction flask equipped with a stirrer, thermometer, water-cooled reflux condenser, nitrogen inletand two laboratory pumps used for metering the monomer and the (VAZO) aZo-bis(isobutyronitrile) streams was charged with 100 g. of unsaturated polyol, prepared as described in Example 1. After flushing the reactor with nitrogen and heating the flask to 125C., at steady and continuous addition was made to the reactor of a stream of a mixture 01 58.2 g. bis(B- chloroethyl) vinyl phosphonate, 74.6 g. vinylidene chloride and-52 g. styrene. A suspension ot&#34;10.8 g. (VAZO) azo-bis(isobutyronitrilc) in 400 g. of the unsaturated polyol described in Example 1 was added in a second stream. The temperature throughout the addition wasmaintained at 125C. to 130C. The monomer stream was added over a period of 45 to 60 minutes while the VAZO stream took about 8 to minutes longer. Upon the completion of the addition of the \&#34;AZ() stream. the reaction mixture was maintained for one hour at 125C. to 130C. The reaction mixture was then stripped for 1 hour at 120C. to 130C. at 10 mm. Hg pressure or less to remove all volatiles. The resulting product had a hydroxyl number of 42, a Brooktield viscosity at C. of 5,800 centipoises, and contained 1.25 percent phosphorus and 5.6 percent chlorine.  
 EXAMPLE V A one-liter reaction flask equipped with a stirrer, thermometer, water-cooled condenser, nitrogen inlet and two laboratory pumps used for metering the monomer and the (VAZO) azo-bis(isobutyronitrile) streams was charged with 332 g. of unsaturated polyol, prepared as described in Example 1. After flushing the reactor with nitrogen and heating the flask to 125C., at steady and continuous addition was made to the reactor of a stream of a mixture of 56 g. bis(B-chloroethyl) vinyl phosphonate and 19 g. of vinylidene chloride and simultaneously with a stream of a mixture of 4.4 g. of (VAZO) azo-bislisobutyronitrilc) in 172 g. of the unsaturated polyol, described in Example 1. The tempera ture throughout the addition was maintained at 125C. to 130C. The monomer stream was added over a pc- -rio&#39;d ol &#39;5-3 min&#39;utes while the VAZO stream addition took about 55 minutes. After the addition otthe VAZO stream. the reaction was maintained for one hour at 125C. to 130C. The reaction mixture was then stripped for one hour at 5 mm. Hg pressure at about 130C. to remove all volatiles. The product had a hydroxyl number of 43, a Brookficld viscosity at 25C. of 2.275 ccntipoises and contained 1.3 percent phosphorus and 3.8 percent chlorine.  
 EXAMPLE V1 A one-liter reaction flask equipped with a stirrer, thermometer. water-cooled condenser, nitrogen inlet and two laboratory pumps used for metering the monomer and the (VAZO) azo-bis( isobutyronitrile) streams was charged with 332 g. of unsaturated polyol, prepared as described in Example 1. After flushing the reactor with nitrogen and heating the flask to 125C., a steady and continuous addition was made to the reactor o1 a stream of a solution of .15 g. of styryl bis(hydroxypropyl) phosphonate in 60 g. ot toluene simultaneously with 4.4 g. of (VAZO) azobislisobutyronitrilc) in 168 g. of the unsaturated polyol, described in Example 1. The temperature was maintained at 121C. to 127C. The monomer stream was added over a period ol40 minutes while the VAZO stream addition took 54 minutes. After the addition of the VAZO stream, the reaction was maintained for one hour at 125C. to 130C. The reaction mixture was then stripped for 1 hour at 5 mm. Hg pressure at about 130C. to remove all volatiles. The product had a hydroxyl number of 63.8. a Brooktield viscosity at 25C. of 1850 centipoises and had a phosphorus content of 0.25 percent by weight.  
 EXAMPLE V11 A. Preparation of an Unsaturated Polyether Polyol A clean, dry, nitrogen-filled stainless steel autoclave equipped with a thermometer, stirrer, nitrogen source, inlet means and heat exchange means was charged with 375 g. of a 335 molecular weight polyol prepared by the condensation of propylene oxide with glycerol in the presence of potassium hydroxide (7 percent by weight based on glycerol). The reactor was evacuated to 10 mm. Hg pressure at room temperature and then heated to C. With constant stirring, a mixture of 127 g. 01 allyl glycidyl ether and 4438 g. of propylene oxide was added over ten hours. The reaction temperature was then maintained at 105C. for 4.5 hours. The reactor was then vented to 0 psig. and then pressurized to 34 psig. with nitrogen. Next, 870 g. ot&#39;ethylene oxide were added over a period of 1.5 hours maintaining the temperature at 105C. Upon completion of the oxide addition, the reaction mixture was maintained at 105C. for 1 hour. The reactor was then cooled to 40C. and the product was discharged. It was treated with an adsorbent, filtered, and then stripped for 1 hour at 10 mm. Hg pressure or less. The product had a hydroxyl number of 37, a Brookticld viscosity at 25C. of 1,000 centipoises and contained about 1.0 mole of allyl glycidyl ether per mole of polyol.  
 B. Preparation of a Transparent Graft Copolymer A reaction flask equipped with a stirrer, thermometer, reflux condenser, nitrogen inlet and two laboratory pumps used for metering the monomer and the (VAZO) a2o-bis( isobutyronitrilc) streams was charged with 332 g. of the unsaturated polyol prepared in section (A) of this example. Upon flushing the reactor with nitrogen, a steady and continuous additionto the reactor was made of a mixture of 62.6 g. of bis(B- chloroethyl) vinyl phosphonate, 137.5 g. aerylonitrile, and 133.3 g. of styrene in one stream concurrently with a suspension of 19.7 g. of (VAZO) azobis(isobutyronitrile) in 168 g. otthe unsaturated polyol as prepared in section (A) of this example in a second stream. The temperature throughout the reaction was maintained at C. to 130C The monomer stream was added over a period of 130 minutes while the VAZO stream took about 10 minutes longer. Upon the completion of the addition of the VAZO stream, the reaction mixture was maintained for one hour at 125C. to 130C. The reaction mixture was then stripped for one hour at 120C. to 130C. at 10 mm. Hg pressure or less to remove all volatiles. The resulting product had a hydroxyl number of 21.9, a Brookfield viscosity at 25C. of 96,000 centipoises and contained added at a temperature of 125C. over a period of 180 minutes. The reaction mixture was then maintained at this temperature for one hour with continuous stirring. The reaction mixture was then stripped for one hour at 0.65 percent phosphorus and 2.6 percent chlorine. 9 than 1 mm- Hg pressure at 125C. The resulting EXAMPLE Vm product had a hydroxyl number of 37.6, a Brookfield viscosity at 25C. of 6,600 centipoises and contained A l-gallon stainless steel autoclave equipped with a 1.51 percent phosphorus and 8.72 percent chlorine. stirrer thermocou le,monomer inlet coolin coils ro- .P EXAMPLE x tameter, and addition bomb was charged with 1,500 g. 10 of the unsaturated polyol, prepared a de ribed in E Polyurethane foam compositions were prepared emample I Upon flu hing the re ti vessel ith mm ploying the graft copolymers of the present invention. gen and ev ti t f ll vacuum th dditi f a 1n add1t1on to the graft polyol, the other ingredients mixture of 93.8 g. of bis(B-ehloroethy1) vinyl phosphomp y and 11 1 118 16F001 include: nate, and 281.2 g. of vinyl chloride in one stream concurrently with a solution of g. of (VAZO) 2120- I bis&#39;(isobutyronitrile) in 375 g. of chloroform in a sec- 0nd stream was made to the reactor at a temperature Graft Copolymcr 33.3 of 105C. The monomer mixture was added over a pemm: A 2- riod of 210 minutes while the addition of the chloro- 20 silicone D0190 1:11-15 form solution of VAZO took an additional five min- .rrclhylulwdlflmm j i Stannous Octoate 0.1-0.25 utes. Upon completion of the VAZO addition, the reac- Tolucnc Diisncymmw tion mixture was maintained at 105C. for three addi- 1 4 l gi i w tional hours with constant stirring. The reaction mixn 7 Table 1 FOAM PROPERTIES Foam prepared from Graft Copolymer of Example 11 Ill 1V Vlll X Rise Time. sec. 183 160 171 142 123 Den y. pcf. 1.93 1.144 2.01 2.01 1.00 Tensile. psi. 12.0 15.9 14.5 &#34;/1 Elongation 148 16 175 &#39;l&#39;ear. pi. 1 9 2.5 2.3 (11).. psi  
  25% Dell. 0.44 0.48 0.53 65% Dell. 0.714 0.77 0.113 Compression Sets.  
  a 111.50% 2.7 5.0 z .11 90% 27.4 7.8 7 Humid Aged.  
  &#34;/7 at 50% 10.2 114.5 7.0 &#39;7; at 00% 42 145.1 (1.7 Air Flow. efm.  
  0.5&#34; H 0 2.7 1.11 7. 0.14 0% Burning &#39;1&#39; ts:  
 &#39;lime self exL, sec. 45.5 23.4 31.2 29.0 31.4 Dist. consumed. in. 3.0 1.9 2.2 2.0 2.1 Burning t \&#39;pe SX 5X SX SX SX SX means self-extinguishing ture was then stripped for /2 hour at less than 1 mm. Hg EXAMPLE X1 pressure at 90C. to remove all the volatiles. The resulting product had a hydroxyl number of 47.8, a Brookfield viscosity at 25C. of 1 1.460 centipoises and con Additional polyurethane foam compositions were prepared employing the graft copolymers of the present invention. The other ingredients employed and tained 0.72 percent phosphorus and 5.8 percent chlo- 5 amounts thereof include;  
 EXAMPLE IX Parts lngrcdient Formulation Graft Copolymer 33.3 20 Polyol B 1 66.7 Water 2.7 2.7 Silicone Y-(1454 0.5 0.5 &#39;lriethylamine 0.24 0.24 Organic Acid Complex 09 0.9 of &#39;lricthylenediumine Bis(dimethylaminoethyl) 0.17 0.17 ether (Crude &#39;l&#39;oluene Diisocyanate/ 34.9 34.9  
 toluene Diisocyanate 50/ 50 mixture. 1.05 Index) TABLE II FOAM PROPERTIES Foam Prepared l&#39;rom *SX means self-extinguishing The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
  l. A fire retardant graft copolymer prepared by the in situ polymerization in the presence of a free radical catalyst at a temperature of from 70C. to about 170C. of  
 a. an ethylenically unsaturated monomer or mixture of monomers, at least one of which contains phosphorus or phosphorus and halogen, and b. an unsaturated polyol having an acid number of about one or less and containing from about 1.0  
 mole to about 2.5 moles of ethylenic unsaturation per mole of polyol, said polymerization carried out by simultaneously adding at a steady rate the monomer and the catalyst to the polyol.  
  2. The copolymer of claim 1 wherein the monomer is bis(B-chloroethyl) vinyl phosphonate.  
  3. The copolymer of claim 1 wherein the monomer is a mixture of bis(B-chloroethyl) vinyl phosphonate and styrene.  
  4. The copolymer of claim 1 wherein the monomer is a mixture of bis(B-chloroethyl) vinyl phosphonate and vinylidene chloride.  
  5. The copolymer of claim 1 wherein the monomer is a mixture of bis(B-chloroethyl) vinyl phosphonate and vinyl chloride.  
  6. The copolymer of claim 1 wherein the unsaturated polyol is prepared by the reaction of an alkylene oxide with the reaction product of maleic anhydride with a polyethcr polyol having an equivalent weight of from 250 to 5,000.  
  7. The copolymer of claim 1 wherein the unsaturated polyol is prepared by the reaction of a polyhydric alcohol having from two to&#39;six hydroxyl groups with a mixture of propylene oxide and allyl glycidyl ether.  
  8. The copolymer of claim 1 wherein the catalyst is azo-bis( isobutyronitrile