MXPA98004643A - Polymer of reinforcement grafting made in fluidosde perfluorocarb - Google Patents

Abstract

Substantially solid reinforcing graft polymers are prepared by polymerizing an ethylenically unsaturated monomer (or mixture of ethylenically unsaturated monomers) with a composition comprising a polyol including a positive amount up to about 1.6 equivalent weight of unsaturation induced per mole of polyol an initiator of free radical, and optionally, an effective amount of a reaction wetner in a perfluorocarbon fluid. The resulting reinforcing graft polymers are particularly useful for polyol dispersions used in the production of polyurethanes having improved physical properties such as load bearing or hardness, tensile strength and tear resistance, for example.

Description

POLYMERS OF REINFORCEMENT GRAFTING MADE OF PERFLUOROCARBON FLUIDS FIELD OF THE INVENTION The present invention relates to reinforcing graft polymers generally, and more particularly, to graft and reinforcement polymers prepared in a perfluorocarbon fluid.

BACKGROUND OF THE INVENTION Reinforcement graft polymers (RGPs) are readily dispersible in conventional polyols to provide stable suspensions of the solid in the liquid phase. Generally the RGPs are terpolymers consisting of monomers such as styrene and acrylonitrile with a third functionalized monomer also referred to as a macromer. The functionalized monomer is generally in the form of a polyol that includes a covalently bonded unsaturated moiety such as a fumarate ester, for example. The three monomers are randomly polymerized through their unsaturated or "vinyl" groups by a free radical mechanism to form higher molecular weight polymers including polystyrene-acrylonitrile phase that is formed into a particle with a polyether phase covalently linked. The reinforcing graft polymers themselves have been known for years. For example, U.S. Patent No. 4,093,573 to Ramlo et al. discloses a polymer dispersion prepared by mixing a finely divided hydroxyl-containing solid polymer with a polyol. The solid hydroxy-containing polymer is prepared by polymerizing, in the presence of a free-radical catalyst and an organic solvent, such as aliphatic alcohols, a larger amount of ethylmonically unsaturated monomer or mixture of mortars and a lower amount of an organic compound finished in hydroxy having one to eight hydroxyl groups, an equivalent weight of 500 to 10,000 and containing a carbon-to-carbon polymerizable double bond. The Patents of E.U.A. Nos. 3,823,201 and its reissued version RE 29,014 to Pizzini et al. describe a highly stable graft copolymer dispersion prepared by in situ polymerization in the presence of a free radical catalyst of a vinyl monomer in a polyol containing from about 0.10 to 0.70 moles of unsaturation per mole of polyol. The resulting dispersions are low viscous liquids which can be used in the preparation of flexible urethane foams.

Still another graft polymer dispersion is described in the U.S. Patent. No. 4,454,255 now reissued as RE 33,291 also to Ramlow et al. Under this reference, low viscosity "white" graft polymer dispersions are prepared by free radical polymerization of an ethyonically unsaturated monomer or mixture of monomers in a polyol mixture containing less than 0.1 mole of unsaturation induced per mole of mixture. of polyol. The process described above is said to provide stable dispersions that do not settle with graft polymer contents of 30 weight percent and higher using mixtures of monomers containing more than about 55 weight percent styrene as the comonomer. Of the known RGPs, the majority use a relatively high amount of 2-propanol > that is, 75-100% of the monomer charge, as a reaction medium, even when some emulsion polymerization work employing water as a solvent has been effected. To form a polyol dispersion, a dispersion of RGP in 2-propanol is mixed with a polyol and separated at elevated temperatures and reduced pressures under agitation. Next, any remaining traces of 2-propanol should be removed. Nevertheless. the removal of 2-propanol without causing damage to the polyol dispersion has proved difficult. Worse still, the traces of alcohol that remain in the foam mixture can present serious problems. For example, low molecular weight monohydroxyl compounds can react with isocyanate, which is often undesirable. With respect to polymerized RGP in emulsion, water is even more difficult to remove than alcohol, and foaming becomes a problem as the last vestiges are removed. In addition to the above, a perceived disadvantage with respect to many of the known graft polyols is the regularly limited numbers of types of monomers that can be employed. For example, certain monomers such as vinylidene chloride require reaction temperatures in excess of about 100 degrees C in order to obtain good conversion to polymer. However, this relatively high processing temperature tends to cause the vinylidene chloride to lose hydrogen chloride and become dark which is highly undesirable. To form dry powders of RGP, as opposed to the polyol dispersions described above, dispersions of polymer of alcohol content have been used elevated where during the removal of alcohol, a relatively rigid paste is produced. The pulp is then spray dried, which results in a powder exhibiting relatively lower polymer damage, but resulting in high processing costs. Recently perfluorocarbon fluids have been proposed for use as a suspension polymerization medium in accordance with an article appearing in "Macromolecules" 1996, 29, 2813-1817 by Zhu. According to the article, certain cross-linked polymer beads can be obtained by suspending mono- and difunctional onos and initiators in perfluorocarbon fluids. The use and function of additives that serve as a dispersant for the monomers in the perfluorocarbon fluid are discussed. While the use of polyfluorocarbon fluids as a means of suspension polymerization to obtain polymer beads crosslinked in this way is known in the art, to date the inventor is unaware of any suggestions in the field related to substantial reinforcement graft polymers and totally non-crosslinked, formed in perfluorocarbon fluids. In particular, it does not seem have any suggestion in the art relating to graft polymers formed in perfluorocarbon fluids having a covalently bonded hydroxyl-terminated polyether on the surface of the polymer bead that allows the polymer particles to form stable dispersions in a continuous polyol phase of polyether In polyurethane foam formulations, it is the hydroxyl termination of the covalently bonded polyether layer that allows the polymer particles to become part of the polyurethane matrix and impart reinforcing characteristics. In the absence of this hydroxyl functionality, the resulting polymer particles would be inert and would simply serve as a filler with little or no reinforcing capacity. Thus, there appears to be a need in the art for cost effective production of reinforcing graft polymers, particularly in powder form, which can be stored for extended periods of time and added to a polyol composition as needed to achieve the desired objective, such as reinforcement of the resulting foam or cell opening, for example.

COMPENDIUM OF THE INVENTION The present invention, therefore, relates both to the product and to the process for forming reinforcing graft polymers comprising the step of polymerizing an ethylenically unsaturated monomer (or mixture of ethylenically unsaturated monomers) in the presence of a composition comprising a polyol including a positive amount of up to about 1.6 weight equivalent of unsaturation induced per mole of polyol, a free radical initiator and, optionally, an effective amount of a reaction moderator in a perfluorocarbon fluid. The resulting RPG, which is generally in the form of an agglomerated powder, is recovered by filtration, at which time the agglomerated powder can be easily broken into a fine powder. Additionally, as an added benefit, unreacted monomers can be decanted together with the perfluorocarbon fluid and then separated for reintroduction into the process stream, if desired. The present invention also relates to reinforcing graft polymer particles that include a covalently bound hydroxyl-terminated polyether on the surface of the polymer, which allows the polymer particles to form Stable dispersions in a continuous phase of polyether polyol, it is considered that the dispersions are particularly useful for the formation of polytretane foams. In addition to obtaining a stable storage sprayed RPG, it is contemplated that a wider range of monomers may be employed in accordance with the present invention compared to those used in known graft polyol processes. Still other objects and advantages of the present invention will become apparent after a review of the following detailed description and appended claims.

DETAILED DESCRIPTION OF THE PREFERRED MODALITY In accordance with the teachings of the present invention, a process for the preparation of solid reinforcing graft polymers comprises the step of polymerizing at least one ethylenically unsaturated monomer or mixture of monomers in the presence of a composition comprising a polyol including a positive amount of up to about 1.6 equivalent weight of unsaturation induced per mole of polyol, a free radical initiator and optionally an effective amount of a reaction moderator in a perfluorocarbon fluid. During the formation of Reinforcing graft polymer in the perfluorocarbon fluid, the polymer can be recovered by simple filtration. By the phrase "a positive amount", it is implied that the polyol will include a certain number of unsaturation equivalents greater than 0.0%, such as at least, for example, 0.001%. By definition, perfluorocarbon fluids are perfluorinated and saturated aliphatic compounds including perfluoroalkanes, perfluoroalkyl ethers and perfluoroalkylamines. Each of the compounds is stable and highly inert, and most organic compounds are not soluble therein. In accordance with the present invention, perfluorocarbon fluids offer a unique way to maintain fluidity in the reaction mixture and facilitate heat transfer, without being involved in the reaction. The reactants are mutually soluble, one with the other, but insoluble in the perfluorocarbon fluid. In this way, the reaction mixture is dispersed in the perfluorocarbon fluid and the polymerization reactions occur in these dispersed droplets. With respect to the reagents, the polyol component will preferably include a polyether ester polyol prepared by the reaction of a polyether polyol of poly-xalkylene with maleic anhydride and an alkylene oxide. This polyether ester polyol is isomerized by methods well known to those skilled in the art. These include heat, or isomerization catalysts such as morpholine, dibutylamine, diethylamine, diethanolamine, thiols and the like. The polyether ester polyol can additionally be prepared by the reaction of a polyoxyalkylene ether polyol, a polycarboxylic acid anhydride to form an acid medium ester and an alkylene oxide to obtain a product having an acid number of less than 5 mg KOH / gram comprising conducting the reaction between the polyoxyalkylene polyether polyol and the anhydride and the following reaction with the alkylene oxide in the presence of an effective amount of a catalyst selected from the group consisting of divalent metal salts and oxides. Polyols having induced unsaturation are referred to below as "macromers". The chain transfer agents can be used as reaction moderators, particularly at temperatures below 105 degrees Celsius. The polymerization reaction can be carried out at temperatures between about 25 degrees and 180 degrees Centigrade. The polyol component contains up to about 1.6 equivalents of unsaturation per mole of polyol. Preferably, the polyol component ranges from 0.45 to 1.5 equivalents of unsaturation and still more preferably 0.9 to 1.1 equivalents of unsaturation per mole of polyol. The alkylene oxides which can be used for the preparation of the polyether ester polyols include ethylene oxide, propylene oxide, butylene oxide, amylene oxide and mixtures of these oxides. The reinforcing graft polymers of this invention vary in physical appearance from finely divided dry powders to thick pasty agglomerates. Among the chain transfer agents, otherwise referred to herein as reaction moderators, which may be employed are: acetic acid, bromoacetic acid, chloroacetic acid, ethyldibromoacetate, iodoacotic acid, tribromoacetic acid, ethyltribromoacetate, trichloroacetic acid, ethylen trichloroacetate, acetone, p-bromophenylacetonitrile, p-nitrophenylacetylene, allyl alcohol, 2,4,6-trinitroaniline, p-ethynylanisol, 2, 4 , 6-trinitroanisole, azobenzene, benzaldehyde, p-cyanocrisine, ethyl trinitrobenzoate, benzoin, benzonitrile, benzopyrene, tributylborane, 1,4-butanediol, 3-epoxy-2-methyl-1-butene, t-butyl ether, isocyanide of t-butyl, 1-phenylbutyne, p-cresol, p-bromoeumeno, dibenzonaphthacene, p-dioxane, pentaphenyl ethane, ethanol, 1,1-diphenylethylene, ethylene glycol, ethyl ether, fluorene, N, N-dimethylformamide, -heptene, 2-hexene, isobutyraldehyde, diethyl bromomalonate, bromotrichloromethane, dibromomethane, diiodomethane, naphthalene, 1-naphthol, 2-naphthol, methyl oleate, 2,4,4-triphenyl-1-pentene, 4-methyl- 2-pentene, 2,6-diisopropylphonol, phenyl ether, phenylphosphine, diethylphosphine, dibutylphosphine, phosphorous trichloride, 1,1-tribromopropanol, dialkyl phthalate, 1,2-propanediol, 3-phosphinopropionitrile, 1-propanol, pyrocatechol, pyrogallol, stearate methyl, tetraethylsilane, triethylsilane, dibromostilbene, alpha-bromostyrene, alpha-methylstyrene, tetraphenyl succinonitrile, 2,4,6-trinitrotoluene, p-toluidino, N, N-dimethyl-ptoluidino, alpha-cyano-p-tolunitrile, alpha, alpha '-dibromo-p-xylene, 2,6-xylenol, diethyl zinc, dithiodiacetic acid, ethyl dithiodiacetic acid, 4, -V-dithio-bisanthranilic acid, benzthiol, o-ethoxybenzthiol, 2,2'-dithiobisbenzothiazole, sulfur of benzyl, 1-dodecantiol, ethantiol, 1-hexanthiol, 1-naphthalethiol, 2-naphthalenylol, 1-octantiol, 1-heptantiol, 1-hexantiol-1-naphthalethiol, 2-naphin-diol, 1-octantiol, 1-heptantiol, 2-octantiol, 1-tetradecantiol, alpha-toluentiol, isopropanol, 2-butanol, carbon tetrabromide and tertiary dodecyl mercaptan. The chain transfer agents employed will depend on the particular monomers or mixtures of monomers employed and the molar ratios of said mixtures. The concentration of the chain transfer agent that is employed can vary from about 2.0 to 10.0 weight percent, based on the weight of the monomer. Representative polyols essentially free of ethylenic unsaturation which can be used in combination with the macromers of the invention are well known to those skilled in the art. They are often prepared by the catalytic condensation of an alkylene oxide or mixture of alkylene oxides either simultaneously or sequentially with an organic compound having at least two active hydrogen atoms, such as is described in US Patents. Nos. 1,922,459; 3,190,927; and 3,346,557. Representative polyols include polyesters containing polyhydroxyl, polyols of polyoxyalkylene polyols, polyurethane polymers terminated in polyhydroxy, phosphorous compounds containing polyhydroxyl and alkylene oxide adducts of polyhydric polythioethers, polyacetals, aliphatic polyols and thiols, ammonia and amines including aromatic, aliphatic and heterocyclic amines, as well as mixtures thereof. The alkylene oxide adducts of the compounds containing 2 or more different groups within the classes defined above can also be used, for example, amino alcohols containing an amino group and a hydroxyl group. Also, alkylene oxide adducts of compounds containing an SH group and an OH group as well as those containing an amino group and an SH group can be used. Generally, the equivalent weight of the polyols will vary from 100 to 10,000, preferably from 1000 to 3000. Any suitable hydroxy-terminated polyester can be used, as prepared, for example, from polycarboxylic acids and polyhydric alcohols. Any suitable polycarboxylic acid can be used, such as oxalic acid, malonic acid, succinic acid, glutamic acid, adipic acid, pi-aic acid, suberic acid, azelaic acid, sebacic acid, brasilic acid, tapsic acid, maleic acid, fumaric acid, acid glutaconic, alpha-hydromuconic acid, beta-hydromuconic acid, alpha-bu-l-alpha-ethyl-glutaric acid, alpha, beta-diethyl-succinic acid, isophthalic acid, acid terephthalic acid, hemimelitic acid and 1-cyclohexanedicarboxylic acid. Any suitable polyhydric alcohol, including both aliphatic and aromatic, can be used, such as ethylene glycol, propylene glycol, trimethylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 1,6-hexanediol , 1,7-heptanediol, glycerol, 1,1-trimethylolpropane, 1,1-trimethylolethane, 1,2,6-hexantiol, alpha-methyl glycoside, pentaerythritol and sorbitol. Also included within the term "polyhydric alcohol" are compounds derived from phenol, such as 2,2-bis (4-hydroxy phenyl) -panole, commonly known as Bisphenol A. The hydroxyl-containing polyster can also be an amide of polyester as obtained by including some amino or amino alcohol in the reagents for the preparation of the polyesters. In this way, the polyester amides can be obtained by condensing an amino alcohol such as ethanolamine with the polycarboxylic acids discussed above or they can be made using the same components that form the hydroxyl-containing polyester with only a portion of the components being a diamine such as ethylenediamine.

Any suitable polyoxyalkylene polyether polyol can be used such as the polymerization product of an alkylene oxide or a mixture of alkylene oxides with a polyhydric alcohol. Any suitable polyhydric alcohol can be used, such as those described above for use in the preparation of the hydroxy-terminated polyesters. Any suitable alkylene oxide can be used such as ethylene oxide, propylene oxide, butylene oxide, amylene oxide and mixtures of these oxides. The polyoxyalkylene polyether polyols can be prepared from other starting materials such as tetrahydrofuran and mixtures of alkylene oxide-tetrahydrofuran; epihalohydrins such as epichlorohydrin; as well as aralkylene oxides such as styrene oxide. The polyoxyalkylene polyether polyols may have hydroxyl groups either primary or secondary. Included among the polyether polyols are polyoxyethylene glycol, polypropylene glycol, polybutylene glycol, polytetramethylene glycol, block copolymers, for example, combinations of polyoxypropylene and polyoxyethylene glycols, poly-1, -oxibutylene and polyoxyethylene glycols, poly-1,4-oxybutylene glycols and polyoxyethylene and random copolymer glycols prepared from mixtures of two or more alkylene oxides or by the sequential addition of two or more alkylene oxides. The polyoxyalkylene polyether polyols can be prepared by any known process such as, for example, the process described by Wurtz in 1859 and Encyclopedia of Chemical Technology, Vol. 7, p. 257-262, published by Interscience Publishers, Inc. (1951) or in the U.S. Patent. No. 1,922,459. Preferred polyethers include the alkylene oxide addition products of trimethylolpropane, glycerin, pentaerythritol, sucrose, sorbitol, propylene glycol, and 2, 2 '~ 4,4 * -hydroxyphenyl) propan and mixtures thereof having equivalent weights of 100 to 5000. Suitable polyhydric polythioethers which can be condensed with alkylene oxides include the condensation product of thiodiglycol or the reaction product of a dicarboxylic acid as described above for the preparation of the polyesters containing hydroxyl with any other suitable thiopter polyol. Polyhydroxyl-containing phosphorus compounds that can be used include those compounds described in the U.S. Patent. No. 3,639,542. Phosphorus compounds that contain Preferred polyhydroxyl are prepared from alkylene oxides and phosphorus acids having an equivalent of P205 from about 72 percent to about 95 percent. Suitable polyacetals which can 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 described above. Suitable aliphatic thiols which can be condensed with alkylene oxides include alkanols containing at least two -SH groups such as 1,2-ethanedithiol, 1,2-propanedithiol, 1,3-propandithiol and 1,6-hexanedithiol; alkene thiols such as 2-buten-1, 4-dithiol,; and alkyne thiols such as 3-hexin-2,6-dithiol. Suitable amines which can be condensed with alkylene oxides include aromatic amines such as aniline, o-chloroaniline, p-aminoaniline, 1,5-diaminonaphthalene, methylene dianiline, the condensation products of aniline and formaldehyde, and 2,3-, 2,6-, 3,4-, 2,5- and 2,4-diaminotoluene; aliphatic amines such as methylamine, triisopropanolamine, ethylenediamine, 1,3-diaminopropane, 1,3-diaminobutanol and 1, -diaminobutane.

Also, polyols containing ester groups can be employed in the present invention. These polyols are prepared by the reaction of an alkylene oxide with an organic dicarboxylic acid anhydride and a compound containing reactive hydrogen atoms. A more understandable discussion of these polyols and their method of preparation can be found in US Patents. A. Nos. 3,585,185; 3,639,541 and 3,639,542. The unsaturated polyols or macromers which are employed in the present invention can be prepared by the reaction of any conventional polyol such as those described above with an organic compound having both ethylonic unsaturation and a hydroxyl, carboxyl, anhydride, isocyanate or epoxy group or they can be prepared by employing an organic compound having both ethylenic unsaturation and a hydroxyl, carboxyl, anhydride or epoxy group as a reagent in the preparation of the conventional polyol. Representative of these organic compounds include unsaturated mono- and polycarboxylic acids and anhydrides such as maleic acid and anhydride, fumaric acid, erotonic acid and anhydride, propylene, succinic anhydride, acrylic acid, acryloyl chloride, hydroxyethyl acrylate or methacrylate and maleic acids. halogenated and anhydrides, ethyl-fumaryl chloride, unsaturated polyhydric alcohols such as 1-buten-1,4-diol, allyl glycerol ether, allyl trimethylolpropane ether, allyl pentaerythritol ether, pentaerythylene vinyl ether, pentaerythritol diallyl ether and -buten-3, 4-diol, unsaturated epoxides such as l-vinylcyclohexen-3, 4-epoxide, butadiene monoxide, vinylglycidyl ether (l-vinyloxy-2,3-epoxy propane), glycidyl methacrylate and -aliloxypropylene (allyl glycidyl ether). If an acid or polycarboxylic anhydride is used to incorporate the unsaturation into the polyols, it is preferable to react the unsaturated polyol with an alkylene oxide, preferably ethylene or propylene oxide, to replace the carboxyl groups with hydroxyl groups before use in the process. present invention. The amount of alkylene oxide employed is such as to reduce the acid number of the unsaturated polyol to about 5 or less. The malevored macromers are isomerized at temperatures ranging from 80 degrees to 120 degrees C for half an hour to three hours in the presence of an effective amount of an isomerization catalyst. The catalyst is employed at concentrations greater than 0.01 weight percent based on the weight of the macromer.

When preparing the polyether ester polyol employing the catalyst selected from the group consisting of divalent metal salts and oxides, the concentration of catalyst that can be used ranges from 0.005 to 0.5 weight percent based on the weight of the mixture. polyol. the temperatures used range from 75 degrees to 175 degrees Celsius. The equivalent weight of the macromer can vary from 1000 to 10,000, preferably from 2000 to 6000. Among the divalent metals that can be used are: zinc acetate, zinc chloride, zinc oxide, zinc neodecanoate, tin chloride, naphthenate calcium calcium chloride, calcium oxide, calcium acetate, copper naphthenate, cadmium acetate, cadmium chloride, nickel chloride, manganese chloride and manganese acetate. Some of the above-mentioned catalysts such as calcium naphthenate promote isomerization of the maleate to the structure during the preparation of the macromer, while others, such as zinc chloride, which is an effective catalyst for polymerization, inhibit this isomerization. As mentioned above, the reinforcing graft polymers of the invention are prepared by polymerizing an ethylenically monomer unsaturated or a mixture of ethylenically unsaturated monomers in a perfluorocarbon fluid. Representative ethylonically unsaturated monomers that can be employed in the present invention include butadiene, isoprene, 1,4-pentadiene, 1,6-hexadiene, 1,7-octadiene styrene, alpha-methylstyrene, 2-methylstyrene, 3-methylstyrene and 4- methylstyrene, 2,4-dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, phenylstyrene, cyclopentylstyrene, benzylstyrene and the like; substitute styrene such as cyanostyrene, nitrostyrene, N, N-dimethylaminostyrene, iodoxyethoxy, Methyl 4-vinylbenzoate, phenoxystyrene, p-vinylphenyl oxide, and the like; substituted and acrylic acrylic monomers such as acrylonitrile, acrylic acid, methacrylic acid, methyl acrylate, 2-hedroxyethyl acrylate, methyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, isopropyl methacrylate, octyl methacrylate, methacrylonitrile, ethyl alpha-ethoxyacrylate, methyl alpha-acetamino acrylate, butyl, 2-ethylhexylacrylate, phenylacrylate, phenyl ethacrylate, N, N-dimethylacrylamide, N, N-dibenzylacrylamide, N-butylacrylamide, methylacrylyl formamide and the like; vinyl esters, vinyl ethers, vinyl ketones, etc., such as acetate of vinyl, vinyl butyrate, isopropenyl acetate, vinyl format, vinyl acrylate, methacrylate and vinyl, vinyl methoxyacetate, vinyl benzoate, vinyl toluene vinylnaphthalene, vinylmethyl ether, vinylethyl ether, vinylpropyl ethers, vinyl butyl ethers, vinyl-2-ethylhexyl ether, vinylphenyl ether, vinyl-2-methoxyethyl ether, methoxybutadiene, vinyl 2-butoxyethyl ether, 3,4-dihydro-1,2-pyran, 2-baptice-2 diethyl ether -vinyloxy, vinylmethyl ketone, vinyl ethyl ketone, vinyl phosphoants such as vinylphenyl ketone, vinylethylsulphone, N-methyl-N-vinylacet amide, N-vinylpyrrolidone, vinylimidazole, divinyl sulfoxide, divinyl sulfone, sodium vinyl sulphous, methyl vinyl sulphonate N-vinylpyrrole, and the like; dimethyl fumarate, dimethyl maleate, maleic acid, crotonic acid, fumaric acid, itaconic acid, monomethyl itaconate, t-butylaminoethyl methacrylate, methylaminoethyl methacrylate, glycidyl acrylate, allyl alcohol, glycol monoesters of itaconic acid, 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 monomers suitable for use in this invention. Preferably, at least 55.0 percent Weight percent of and up to 100.0 weight percent of the monomer employed is selected from the group consisting of styrene, 4-methylstyrene, acrylonitrile, vinylidene chloride and mixtures thereof. The amount of ethylenically unsaturated monomer employed in the polymerization reaction is generally from 50.0 percent to 80.0 percent, and more preferably, from about 65.0 to about 75.0 percent based on the total weight of the polymer. The polymerization occurs at a temperature between about 25 degrees C and 180 degrees C, preferably 80 degrees C to 135 degrees C. Illustrative polymerization initiators that may be employed are the well known free radical types of vinyl polymerization initiators such such as peroxides, persulfates, perborates, percarbonates, azo compounds, etc. These include hydrogen peroxide, dibenzoyl peroxide, acetyl peroxide, benzoyl hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, butyryl peroxide, diisopropylbenzene hydroperoxide, eumeno hydroperoxide, hydroperoxide paramentane, diacetyl peroxide, di-alpha-cumyl peroxide, dipropyl peroxide, diisopropyl peroxide, isopropyl-t-butyl peroxide, butyl-t-butyl peroxide, difuroyl peroxide, bis (triphenyl) peroxide, bis (p-methoxybenzoyl) peroxide, p-monomethoxybenzoyl peroxide, rubenoperoxide, ascaridol, t-butyl peroxybenzoate, diethyl peroxyterephthalate, propyl hydroperoxide, isopropyl hydroperoxide, n-butyl hydroperoxide, t-butyl hydroperoxide, cyclohexyl hydroperoxide, trans-decalin hydroperoxide, alpha-methylbenzyl hydroperoxide, alpha-methyl-alpha-ethylbenzyl hydroperoxide, tetralin hydroperoxide, triphenylmethyl hydroperoxide, diphenylmethyl hydroperoxide, alpha, alpha '-azobis (w-methylheptonitrile), 1,1''-azo-bis-cyclohexane carbonitrile), 4,4'-azobisf 4-cyanopentanoic acid, 2,2'-azobis. { isobutyronitrile), 1-t-butylaza-l-cyanocyclohexane, persuccinic acid. diisopropyl peroxy 2,2'-azobis (2, -dimethylvaleronitrile) dicarbonate, 2-t-butylazo-2-cyanomethyloxymethylpentane, 2,2'-azobis-2-methylbutanonitrile, 2-t-butylaza-2-cyanobutane, 1- t-amylazole-l-cyanocyclohexane, 2, '-azobis-2, -dimethylmethoxy-lactitrile, 2,2'-azobis-2-methylbutyronitrile, 2-t-butylaza-2-cyano-4-methylpentane, 2-t-butylazo-2-isobutyronitrile, butylperoxyisopropyl carbonate and the like; a mixture of initiators can also be used. Preferred initiators are 2, 2'-azobis (2-methylbutyronitrile), 2,2'-azobi (isobutyronitrile, 2,2'-azobis, 2,4-dimethylvaleronitrile), 2-t-butylaza-2-cyano 4-methoxy-4-methylpentane, 2-t-butylazao-2-cyano-methylpentane, 2-t-butylazo-2-cyano-butane and aluroyl peroxide. Generally, from about 0.01 percent to about 10 percent, preferably from about 1.0 percent to about .0 percent, by weight of initiator based on the weight of the monomer will be employed in the process of the invention. Perfluorocarbon fluids which are considered to be particularly useful include perfluoroalkanes, perfluoroalkyl ethers and perfluoroalkylamines, but perfluoroalkanes are preferred because they are more readily available and possess the requisite properties of inertia and chemical stability. They are available in a wide variety of boiling scales and are selected so as to match their reflux temperature with the desired reaction temperature. A source of appropriate perfluorocarbon fluids are liquids Fluorinert (K) of 3M Industrial Products Division. While it is considered that these mixtures of perfluoroalkanes instead of a pure compound, it is believed that the scale of boiling point and not necessarily purity is important. Polyurethane foams can be formed using polymers d? reinforcement graft of the present invention. Polyurethane foams are formed by reacting the reinforcing graft polymers with an organic polyisocyanate in the presence of a blowing agent and optionally in the presence of additional polyhydroxyl-containing components, chain extenders, catalysts, tension agents, stabilizers, colorants, dyes and pigments. Appropriate processes for the preparation of cellular polyurethane plastics are described in the U.S. Patent. No. Re 24,514 together with the appropriate machine to be used in conjunction with them. When water is added with the blowing agent, excess amounts of isocyanate can be used to react with the water and produce carbon dioxide. It is possible to proceed with the preparation of the polyurethane plastics by a prepolymer technique in which an excess of organic polyisocyanate is reacted in a first step with the polymer of reinforcement graft of the present invention for preparing a prepolymer having free isocyanate groups which is then reacted in a second step with water and / or a polyol to prepare a foam, alternatively, the reinforcing graft polymer can be added to a composition of polyol to form a dispersion in a continuous phase polyol. Next, the polyol dispersion can be added to an isocyanate composition to form a polyurethane foam. Still another option is to add the reinforcing graft polymer to the polyol components in a single stage of work commonly known as the "one shot" technique for preparing polyurethanes. Additionally, instead of water, low boiling hydrocarbon blowing agents such as pentane, hexane, heptane, pentane and heptane can be used with blowing agents; azo compounds such as azohexahydrobenzodinitrile, halogenated hydrocarbons such as dichlorodifluoromethane, halogenated hydrocarbons such as dichlorodifluoromethane, trichlorofluoromethane, dichlorodifluoroethane, vinylidene chloride and methylene chloride. The organic polyisocyanates that may be employed include aromatic, aliphatic and cycloaliphatic polyisocyanates and combinations thereof. They are representative of these types are diisocyanates such as m-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, mixtures of 2, k4- and 2,6-toluene diisocyanate, hexamethylene diisocyanate, diisocyanate of tetramethylene, cyclohexane-1,4-diisocyanate, hexahydrotolscene diisocyanate (and isomers), nephthalene-1,5-diisocyanate, 1-methoxy-pheny1-2,4-diisocyanate, 4,4'-diphenylmethane diisocyanate, 4-diisocyanate, , 4-biphenylene, 3,3'-dimethoxy-, 4-biphenyl diisocyanate, 3,3 '-dimethyl-4,4'-biphenyl-3,3'-dimethyldiphenylmethane-4-dimethyl-2-diisocyanate, 2'-5, 5'-tetraisocyanate and polymeric polyisocyanates such as polymethylene polyphenylene polyisocyanate. Especially useful due to their availability and properties are toluene diisocyanate, 4'-diphenylmethane diisocyanate and polymethylene polyphenylene polyisocyanate. The crude polyisocyanates can also be used in the compositions of the present invention, such as crude toluene diisocyanate obtained by the phosgenation of a mixture of diamines of toluene or crude diphenylmethane isocyanate obtained by the phosgenation of crude diphenylmethanediamine. The Preferred or crude isocyanates are described in the patent of E.U.A. No. 3,215,652. As mentioned above, the reinforcing graft polymers can be used together with another polyhydroxyl-containing component commonly employed in the art. Any of the polyhydroxyl-containing components that are described above for use in the preparation of the graft polymers can be employed in the preparation of the polyurethane foams useful in the present invention. Chain extender agents that can be employed in the preparation of polyurethane foams include those compounds having at least two functional groups containing active hydrogen atoms such as water, hydrazine, primary and secondary diamines, amino alcohols, amino acids, hydroxy acid, glycols or mixtures thereof. A preferred group of chain extender agents includes water, ethylene glycol, 1,4-butanediol and primary and secondary diamines that react more readily with the prepolymer than water such as phenylenediamine, 1,4-cyclohexane-bis- (methylamine), ethylenediamine , diethylenetriamine, n- £ 2-hydroxypropyl) ethylenediamine, N, N'-di (2-hydroxypropyl) ethylenediamine, piperazine and 2-methylpiperazine, Any suitable catalyst can be used, including tertiary amines such as, for example, triethylene diamine, N-methylmorpholine, N-ethylmorpholine, diethylene tannoline, N-co-morpholine, l-methyl-4-dimethylamino-ethylpiperazine, 3-methoxypropyl tilamine, N , N, N '-trimethylisopropylpropylenediamine, 3-diethylaminopropyldiethylamine, dimethylbenzylamine, and the like. Other suitable catalysts are, for example, stannous chloride, dibutyltin di-2-ethylhexanoate, stannous oxide, as well as other organometallic compounds such as are described in US Pat. No. 2,846,408. A surfactant is generally necessary for the production of high-grade polyurethane foams in accordance with the present invention, since in the absence thereof, the foams are squashed or contain very large uneven cells. Numerous surfactants have been found satisfactory for the production of polyurethane foams. Nonionic surfactants are preferred. Of these, nonionic surfactants such as well-known silicones have been found particularly desirable. Other surfactants that are operative, even if not preferred, include polyethylene glycol ethers of long-chain alcohols, tertiary amine or alkanolamine salts of long chain alkyl acid sulfate esters, alkyl sulfonic esters and alkyl aryl sulfonic acids. It has been found in the preparation of the flame retardant polyurethane foam products that they have incorporated therein a reinforcing graft polymer of the invention, that less flame retardant compound is necessary to impart the flame retardancy. Among the flame retardants that can be used are: pentabromodiphenyl oxide, dibromopropanol, bis (beta-chloropropyl) phosphate, 2,2-bis (bromoethyl) l, 3-propanediol, tetrakis (2-chloroethyl) ethylen diphosphate, thirs (2, 3dibromopropyl) phosphate, tris (beta-chloroethyl) phosphate, tris (1,2-dichloropropylphosphate, bis (2-chloroethyl) 2-chloroethylphosphonate, molybdenum trioxide, ammonium molybdate, ammonium phosphate, pentabromodiphenyloxide, tricresyl phosphate , β-bromobicyclododecane and dibromoethyl-dibromocyclohexane The concentrations of flame retardant compounds that can be used vary from 5 to 25 parts per 100 parts of polyol mixture.

The following examples illustrate the nature of the invention. Unless stated otherwise, all parts are expressed in parts by weight. Polyol A is an adduct of glycerin, propylene oxide, ethylene oxide containing 18.5% ethylene oxide, which has a hydroxyl number of 35.

Polyol B is an adduct of glycerin, propylene oxide, ethylene oxide containing 12.5% ethylene oxide and a hydroxyl number of 51. Polyol C is a reaction product of one mole of Polyol E with 0.81 moles of anhydride maleic in the presence of calcium naphthenate and excess propylene oxide. The product has a typical unsaturation content of 0.5 meq / kg and a hydroxyl number of 22. Polyol D is a reaction product of one mole of Polyol F with 0.96 moles of maleic anhydride in the presence of calcium naphthenate and excess oxide. propylene. The product has a typical unsaturation content of 0.45 meq / kg and a hydroxyl number of 24. Polyol E is an adduct of trimethylolpropane, propylene oxide, ethylene oxide containing 5% ethylene oxide and a hydroxyl number of 25.

Polyol F is an adduct of glycerin, propylene oxide, ethanol oxide containing 55% ethylene oxide and a hydroxyl number of 25. VAZO 52 2, 2'-azobis (, 4-dimethylpentonitrile). a polymerization initiate made by the ssPon Cn V? ZQ 67 2, 2 '- -axobisC 2 -me tilbutanoni ilo), a polymerization initiator made by BuPonl C. As shown in Table 1 below, several samples were prepared in an experiment to determine which compositions gave rise to a powder and, preferably, a soft powder that can be dispersed to the PTSP. impal, various properties such as refue zo, increased cliifesa, better cell opening and improved flame retardancy to urethane foams made using the resulting powders, for example.

TABLE 1 1 2 3 4 5 6 Acrylonitrile 56 40 24 25 25 26 Styrene 28 40 48 50 50 50 Vinylidene Chloride Polyol A Polyol B 9 15 25.7 25 5 5 Polyol C 5 3.6 2.25 2.25 2.25 Polyol D 20 2-Propanol VAZO 52 VAZO 67 2 1 0.7 0.75 0.7 0.7 Octane Perfluorinated 265.8 23 189 225 193 174 2 6 3 2 5 Remarks ** sp hpa glass glass sp sp TABLE 1 (continued) 7 8 9 10 11 12 Acrylonitrile 20 20 30 15 20 80 Styrene 40 40 Vinylidene Chloride 30 45 40 160 TABLE 1 (continued) 9 10 11 12 Polyol A 21 12.6 11 86.9 Polyol B 20 .8 Polyol C 2, .4 2.4 Polyol D 3 3 5 20 2-Propanol 3.12 3.2 1.9 2 2 VAZO 52 0.62 0.6 0.31 0.5 1.6 VAZO 67 0. .7 Octane Perfluorinated 156. .3 160 16 160 160 500 0 Observations ** po sp hpa hpo sp sp TABLE 1 (Continued) 13 14 15 16 17 18 19 Acrylonitrile 80 20 20 20 20 20 20 Styrene 40 40 40 40 Vinylidene Chloride 160 40 42.9 Polyol A 20.8 42.4 Polyol B 62.4 20. 8 20. 8 20., 8 Polyol C 2.4 2. 4 2. 4 2. 4 TABLE 1 (continued) 13 14 15 16 17 18 19 Polyol D 20 2.4 3.6 2-Propanol 2 3.1 3.2 25 25 25 VAZO 52 1.1 0.6 0.5 0.5 0.5 0.5 0.5 VÁZO 67 Octano Perfluorado 450 161 160 160 160 160 160 Observations ** s pa ap wl po vsp hpo = hard powder sp = soft powder hpa = hard particles pa = paste psp = pasty powder wl = very viscous liquid po = powder vsp - very soft powder Each of the samples was prepared by loading all the ingredients listed in Table 1 into a 3-neck, 500 ml, round bottom flask equipped with a reflux condenser, stirrer, nitrogen inlet, thermometer and heating mantle. The compositions were stirred and heated to reflux and allowed to react for 4-6 hours. Examples where solid polymers were formed were then allowed to cool and then any remaining clear liquid was decanted. The residue was then removed under reduced pressure without stirring to remove any perfluorinated octane and remaining unreacted monomers. The dried powder was then separated by filtration for subsequent use as a dispersion in a polyol composition. The material that was decanted, that is, perfluoroctane, was substantially clear. In this way, it is contemplated that the liquid can be used without requiring purification before the next test. The liquid isolated during the purification step included some unreacted monomers and / or 2-propanol however, the composition can be easily separated using a common separation funnel, for example. In this way, with careful process controls it is contemplated that the fluorinated solvent can be recovered and recycled indefinitely and the monomers can be completely converted into subsequent batches. As it should be easily recognized from In a review of the discussion and previous examples, the present invention provides a process for obtaining reinforcing graft polymers that eliminate costly processing steps such as air drying and grinding that are commonly required in order to obtain the sprayed product.

Claims (28)

1. A solid reinforcing graft polymer, comprising: the reaction product of a) a monomer or mixture of ethylenically unsaturated monomers; b) in the presence of a composition comprising a polyol including a positive amount of up to 1.6 equivalent weight of unsaturation induced per mole of polyol; c) a free radical initiator; and d) optionally, an effective amount of a reaction moderator; wherein the reaction is carried out in an inert perfluorocarbon fluid.

2. The reinforcing graft polymer of claim 1, wherein the ethylenically unsaturated monomer is selected from the group consisting of styrene, 4-methylstyrene, acrylonitrile, vinylidene chloride and mixtures thereof.

3. The reinforcing graft polymer of claim 1, wherein the polyol is prepared by the reaction mixture of an alkylene oxide with maleic anhydride in the presence of calcium naphthanate and excess propylene oxide.

4. The reinforcing graft polymer of claim 1, wherein the polyol contains about 0145 to about 1.5 moles of unsaturation per mole of polyol.

5. The reinforcing graft polymer of claim 1, wherein the polyol component contains from about 0.9 to about 1.1 moles of unsaturation per mole of polio.

6. The reinforcing graft polymer of claim 1, wherein the amount of ethylenically unsaturated monomer or monomer mixture is between about 50.0 to about 80.0 weight percent based on the total weight of the polymer.

7. The reinforcing graft polymer of claim 1, wherein the amount of the ethyonically unsaturated monomer or monomer mixture is between about 65.0 to about 75.0 weight percent based on the total weight of the polymer.

8. The reinforcing graft polymer of claim 1, wherein the polymer is in the form of a particle having a hydroxyl-terminated polyether covalently linked on the surface thereof.

9. The reinforcing graft polymer of claim 1, wherein the polymer is dispersed in the polyol.

10.- A reinforcing graft polymer substantially solid, prepared by polymerizing in the presence of a free radical initiator, at a temperature from about 25 ° C to about 180 ° C: (a) an ethyonically unsaturated monomer or monomer mixture; and (b) a polyol containing from 0.45 to about 1.5 moles of unsaturation per mole of polyol, the unsaturation being incorporated by the reaction of an alkylene oxide with maleic anhydride, the polymerization being carried out by introducing a mixture of components a) and b) in a perfluorocarbon fluid.

11. The reinforcing graft polymer of claim 10, wherein the ethylenically unsaturated monomer is selected from the group consisting of styrene, 4-methylstyrene, acrylonitrile, vinylidene chloride and mixtures thereof.

12. The reinforcing graft polymer of claim 10, wherein the polyol contains from about 0.9 to about 1.1 mole of unsaturation per mole of polyol.

13. The reinforcing graft polymer of claim 10, wherein the amount of the ethylenically unsaturated monomer or monomer mixture is from about 50.0 to about 80.0 percent. by weight based on the total weight of the polymer.

14. The reinforcing graft polymer of claim 10, wherein the amount of ethylenically unsaturated monomer or monomer mixture is between about 65.0 to about 75.0 weight percent based on the total weight of the polymer.

15. A polyol dispersion comprising: a) a polyether polyol composition; and b) the reaction product of a) an ethylenically unsaturated monomer or monomer mixture; b) in the presence of a composition comprising a polyol including a positive amount of up to 1.6 equivalent weight of unsaturation induced per mole of polyol; c) a free radical initiator; and d) optionally, an effective amount of a reaction moderator carried out in the presence of an inert perfluorocarbon fluid, wherein the reaction product is dispersed in a continuous phase of a).

16. The reinforcing graft polymer of claim 15, wherein the ethylenically unsaturated monomer is selected from the group consisting of styrene, 4-methylstyrene, acrylonitrile, vinylidene chloride and mixtures thereof.

17. The reinforcing graft polymer of claim 15, wherein the polyol is prepared by the reaction mixture of an alkylene oxide with maleic anhydride in the presence of calcium naphthanate and excess propylene oxide.

18. The reinforcing graft polymer of claim 15, wherein the polyol contains from about 0.45 to about 1.5 moles of unsaturation per mole of polyol.

19. The reinforcing graft polymer of claim 15, wherein the polyol contains from about 0.9 to about 1.1 moles of unsaturation per mole of polyol.

20. The reinforcing graft polymer of claim 15, wherein the amount of ethylenically unsaturated monomer or monomer mixture is from about 50.0 to about 80.0 weight percent based on the total weight of the polymer.

21. The reinforcing graft polymer of claim 15, wherein the amount of ethylenically unsaturated monomer or monomer mixture is between about 65.0 to about 75.0 weight percent, based on the total weight of the polymer.

22. The reinforcing graft polymer of claim 15, wherein the polymer is in the form of a particle having a hydroxyl-terminated polyether covalently linked to the surface of the polymer. same.

23. A polyurethane foam prepared by the reaction of an organic polyisocyanate with a substantially solid reinforcing graft polymer, prepared by: introducing the reaction product of (a) an ethylenically unsaturated monomer or mixture of monomers b) in the presence of a polyol containing from 0.45 to about 1.5 moles of unsaturation per mole of polyol, the unsaturation being incorporated by the reaction of an alkylene oxide with maleic anhydride, the reaction product being formed in a perfluorocarbon fluid.

24. The polyurethane foam of claim 23, prepared in the presence of a blowing agent.

25. The reinforcing graft polymer of claim 23, wherein the ethylenically unsaturated monomer is selected from the group consisting of styrene, 4-methylstyrene, acrylonitrile, vinylidene chloride and mixtures thereof.

26. The reinforcing graft polymer of claim 23, wherein the polyol contains from about 0.9 to about 1.1 moles of unsaturation per mole of polyol.

27. - The reinforcing graft polymer of claim 23, wherein the amount of ethylenically unsaturated monomer or monomer mixture is between about 50.0 to about 80.0 weight percent based on the total weight of the polymer.

28. The reinforcing graft polymer of claim 23, wherein the amount of ethylenically unsaturated monomer or monomer mixture is between about 65.0 to about 75.0 weight percent, based on the total weight of the polymer.