Polymer polyol composition and their use in the preparation of polyurethane foams

Abstract: Polymer polyol compositions are provided which are useful for the production of flexible polyurethane foams. The polymer polyol compositions are composed of (1) a high functionality polyol, (2) a subsidiary polyalkylene oxide high in polyoxyethylene content and (3) a stably dispersed polymer. The latter component is formed by in situ polymerization of low molecular weight compounds within components (1) and/or (2) used in making the polymer polyol composition. The polymer polyol compositions provide stable and non-shrinking, free-­ rise foam at high water levels and over a wider crosslinker and index range permitting increased density and load latitude relative to commercial high resilience polymer polyols. A process for their use and foams and articles prepared therefrom are also provided.

Description: FIELD OF THE INVENTION This invention relates in general to certain polymer polyol compositions and their use in the production of flexible polyurethane foams. In one aspect, this invention relates to multi-component compositions for making flexible polyurethane foams wherein the compositions are comprised of a high functionality polyol, a subsidiary polyol high in poly(oxyethylene) content and a stably dispersed polymer. In a further aspect, the invention is directed to the use of the polymer polyol compositions in the preparation of foams which affords enhanced latitude for varying formulation components. The invention also relates to foams and foamed articles prepared from formulations containing such compositions. BACKGROUND OF THE INVENTION Polyurethane foams are widely employed in the manufacture of a variety of products and, depending on the end use, can be tailor made to fit the particular application and desired physical properties. For example, high resilience (HR) foam is widely used in furniture, mattresses, automotive and numerous other applications. It is differentiated from conventional foam by its higher comfort or support factor and higher resilience. Specific guidelines have been set forth in ASTM Method D3770 for defining HR foams; however, in practice a such wider class of foams are described by this terminolgy and the present invention is intended to encompass this broader classification. High resilience slabstock foam formulations employed commercially typically contain (1) a polymer polyol consisting of a polymer stably dispersed in a reactive ethylene oxide end-capped polyol having more than 50% primary hydroxyl groups; (2) water; (3) a low molecular weight crosslinker/extender, usually diethanolamine (4) a polyether-silicone copolymer stabilizer; (5) amine and tin catalysts; (6) toluene diisocyanate and miscellaneous other additives such as fillers, flame retardants, blowing agents and the like. Molded high resilience foam can usually be made from high resilience slabstock systems by altering the catalyst compositions; the slabstock foam usually being made with significantly more tin catalyst than is desirable for processing molded foam. Slabstock foam is made almost exclusively with toluene diisocyanate isomer blends while blends of polymeric methylene diisocyanate and toluene diisocyanate are sometimes used for molded foam. Typical unfilled and water-blown high resilience slabstock foams made commercially range from 29 - 56 kg/m³ (1.8 to 3.5 pcf) while those containing physical blowing agents are generally less than about 29 kg/m³ (1.8 pcf). Loads 25 % IFDs) range from 280 to 1120 kg/m² (20 to 80 lbs/50 sq.in) for water blown foams down to 98 to 280 kg/m² (7 to 20 lbs/50 sq.in) for foams containing physical blowing agents such as chlorofluorocarbons. Prior to the present invention, production of low density (less than 29 kg/m³ (1.8 pcf) and/or low load (less than 280 kg /m² (20 lbs/50 sq.in) HR slabstock grades without physical blowing agents had been limited due to little or no processing latitude for the formulations necessary to make these grades. The processing latitude of commercial HR slabstock foam is usually characterized by the diethanolamine (DEOA) and index ranges that give acceptable processing. A broad range is desirable for not only processing but also grade flexibility since load decreases as the DEOA level increases and index is decreased. The lower DEOA limit is characterized by excessive settle or collapse while, at the upper limit, the foam will show shrinkage (excessive tightness). For a typical commercial polymer polyol, the DEOA latitude will depend on factors such as isocyanate index, water level, catalyst types/levels, surfactant and machine parameters. In general, it becomes difficult to find a DEOA level that will yield stable and non-shrinking foam at water levels higher than 3.2 and/or indices above 115 and below 100. This results in more off-grade production and increased manufacturing costs. Although a wide variety of methods and polyurethane formulations have been reported in the patent literature, to date none has disclosed nor taught the polymer polyol compositions and formulations of the present invention. Polymer polyols in which the polyols contain 3 to 10 percent ethylene oxide, have an equivalent weight greater than 1250 and have average functionality greater than 3.2 have been reported in U.S. - A - 4,111,865 and are indicated to yield flexible foams with improved static fatigue and humid sensitivity. However, free-rise foams made with these compositions were tight and exhibited shrinkage. U.S. - A - 3,857,800 and G.B. - A - 1,339,442 disclose the use of a subsidary polyol high in poly(oxyethylene) in conjunction with a polyoxyethylene capped oxypropylene polyol, wherein the subsidary polyol assists in opening the foam cells to avoid shrinkage. Examples are provided in which a crosslinking agent was used but no disclosure related to the use of polymer polyols was indicated. All commercially useful systems for producing high resilience foam rely on polymer polyols; whereas the stably dispersed polymer component provides shrinkage resistance. Ommission of polymer polyol from HR foam formulations employing catalyst combinations that yield commercially acceptable cure rates and silicone surfactants yielding acceptable cell structure results in severe shrinkage even if a subsidiary polyol high in poly(oxyethylene) is employed. The catalysts and stabilizer combinations utilized in the examples of this patent would not yield commercially viable systems for making flexible polyurethane foam. Processing latitude and formulating flexibility would be very limited. Numerous other patents, both domestic and foreign, disclose and claim various polyol blends but for the most part, none employs polymer polyols and/or else differ in the composition of the formulation such that desirable HR flexible foams having improved processing advantages are not provided. See for example, Japanese patents SHO 57-133112; SHO 57-195113; SHO 57-195725; and SHO 59-100125; U.S - A - 4,544,678; G.B. - A - 1,480,972; U.S. - A - 4,690,955, and the like. Hence, prior to the present invention high resilience foam formulations were not readily available having the desirable latitude for varying formulation components without adversely affecting processing and desired physical properties. Current. HR slabstock systems become deficient in processing as the water level in the formulation is increased to make lower density foams; and/or as the crosslinker level is increased or decreased beyond current limits; and/or as the index is increased or decreased beyond current limits. These limitations restrict the range of foam grades (i.e., density and load) that can be produced and limit the markets/applications in which they have been used. Prior to the present invention the production of flexible HR foam densities below 29 kg/m³ (1.8 pcf) and/or loads below 280 kg/m² (20 lbs/50 sq.in), typically required the use of blowing agents such as the halocarbons. However, due to environmental considerations, the current trend is to avoid or minimize the use of such blowing agents in the preparation of foams. Also, production of higher load HR grades has required the use of expensive load building additives that can now be eliminated or greatly reduced under the teachings of this invention. OBJECTS OF THE INVENTION Accordingly, one or more of the following objects will be achieved by the practice of this invention. It is an object of this invention to provide polymer polyol compositions for use in the production of high resilience, flexible, polyurethane foam. Another object is to provide polymer polyol compositions the use of which affords enhanced latitude for varying formulation components without adversely affecting processing conditions or foam properties. A further object of the present invention is to provide polymer polyol compositions useful for the production of HR flexible polyurethane foam which are comprised of multi-component polymer polyol systems. A still further object of this invention is to provide an improved process for the preparation of HR, flexible, polyurethane foam having enhanced formulating latitude and flexibility in the preparation of such foam. Another object of this invention is to provide formulations which are useful in the preparation of HR polyurethane foam which avoid or minimize the use of environmentally unacceptable blowing agents such as the halocarbons. A further object is to provide foams and foamed articles prepared from formulations containing the polymer polyol compositions of this invention. These and other objects will become apparent to those skilled in the art in the light of the teachings herein set forth. SUMMARY OF THE INVENTION In its broadest aspect, this invention provides a polymer polyol useful in the preparation of flexible polyurethane foams and which affords enhanced latitude for varying formulation components to make foams with broad load and density ranges, said polymer polyol comprising: (a) a high functionality polyalkylene oxide polyol, or a blend of such polyols, with an equivalent weight between 1000 and 3000 an ethylene oxide content between 8 and 25% and an average nominal functionality of at least 3, said polyol or polyol blend being present in an amount from 30 to 90 weight percent of the polymer polyol; (b) a subsidiary polyalkylene oxide polyol with a molecular weight between 450 and 30000 and having a poly (oxyethylene) content greater than 30%, said polyalkylene oxide polyol being present in an amount of from 1 to 20 weight percent based on the polymer polyol; the average nominal functionality of the mixture of (a) and (b) being at least 3.0; and (c) a stably dispersed polymer formed in situ by polymerization of low molecular weight compounds within the mixture of (a) and (b) or within one or more of the components of (a) and/or (b); wherein the polymer is present in an amount of from 2 to 50 weight percent of the polymer polyol. By "functionality" is meant the number of active or Zerewitinoff hydrogen atoms per molecule. Where a mixture of polyols is employed, the average nominal functionality is the average functionality of the mixture. By utilizing the polymer polyol compositions of this invention unusually broad processing and formulation flexibility is provided for the production of HR polyurethane foams. DETAILED DESCRIPTION OF THE INVENTION As indicated above, this invention is directed, in part, to polymer polyol compositions useful in the production of flexible polyurethane foam and wherein the polymer polyol is composed of a high functionality polyol or a polyol blend, a subsidiary poly(alkylene oxide) and a stably dispersed polymer. By the term "polymer polyol" or "polymer polyol composition" as employed throughout the specification and appended claims, is meant a stable dispersion of a solid polymer phase within the liquid polyol, polyol blend or polyol containing blend, wherein the solid polymer is formed by in situ polymerization of low molecular weight compounds within the liquid phase. The first component is present in the polymer polyol composition in an amount of from 30 to 90 percent by weight based on the weight of the total composition and is a polyalkylene oxide polyol or blend of such polyols having an average nominal functionality such that the combination of the first and second components will have an average nominal functionality of 3.0 or greater, and preferably within the range of from 3.2 to 6.0. In a preferred embodiment, the first component is a blend of a high primary hydroxyl poly(oxyethylene) end-capped poly(oxypropylene) polyol and a predominantly secondary hydroxyl polyalkylene oxide polyol. The second component is present at between 1 and 20 weight percent and is a polyalkylene oxide containing greater than 30% by weight of poly(oxyethylene). The third component is present at between 2 and 50% by weight and is a stably dispersed polymer formed by the in situ polymerization of low molecular weight compounds within the blend of components 1 and 2 or within one or more of the polyalkylene oxides used to constitute components 1 and 2. Such a polymer polyol composition yields stable and non-shrinking, flexible, polyurethane foam at higher water levels and over a wider crosslinker/extender and index range; thus allowing increased density and load latitude relative to current HR polymer polyols (See tables I, II, III, and X). Accordingly, the present invention allows the production of lower density flexible foams and foams with increased load latitude. Current slabstock polymer polyols have limited processing latitude (narrow DEOA and index range) at water levels above 3.2 parts per hundred (php) of the polymer polyol blend. In accordance with the present invention, good latitude has been maintained to greater than 4.5 php. The ability to make these low density grades coupled with the ability to make foams with a broader load range without blowing agent or load builder will make these blends commercially attractive for the production of polyurethane foam. As indicated previously, present environmental considerations are expected to lead to the avoidance of hydrocarbons such as the freons, as blowing agents in the production of urethane foams. High density HR foams>37 kg/m³ (>2.3 pcf) with wide load range also can be made with these polymer polyol combinations; thus offering the full range of high density HR foams currently produced plus the ability to make higher load grades (25% IFD of 560 kg/m² (40 lbs/50 sq.in) or higher)without the need for added load builders. Various blends of polymer polyols within the scope of the present invention have shown good foam processing characteristics as will be evident from the data presented in Tables IV-VIII. In practice the high functionality polyol can be polyalkylene oxide polyols or blends of such polyols of average nominal functionality between 3 and 6; having an ethylene oxide content between 8% and 25% by weight; and an equivalent weight between 1000 and 3000, preferably from 1600 to 2200. In one preferred embodiment, the high functionality polyol is a poly(oxyethylene -oxypropylene) copolymer. The high functionality polyol is employed at levels ranging from 30% to 90%, and preferably from 40% to 90%, based on the weight of the total blend. The subsidiary polyalkylene oxide, the second component of the polymer polyol composition, can have a molecular weight between 450 and 30,000; nominal functionality up to about 8 and preferably between 2 and 8; and ethylene oxide content between 30 and about 100% and preferably at least 50% by weight. The lower molecular weight (450 to 2000) liquids with ethylene oxide content greater than 70%, are preferred for ease in handling and optimum processing. In one preferred embodiment, the subsidiary polyalkylene oxide is a poly(oxyethylene-oxypropylene) copolymer which preferably is comprised of at least 50% by weight of poly(oxyethylene). The level of this second component can be varied from 1% to 20% by weight of the polymer polyol composition with 1% to 10% as the preferred range. The third component of the composition can be a standard vinyl polymer or copolymer; a polyurea-type polymer; or a condensation product of a polyfunctional low molecular weight glycol or glycol amine with a diisocyanate. This component is formed as a stable dispersion in one or more of the polyols by in situ polymerization of the monomers. The level of the stably dispersed polymer can vary between 2% and 50% by weight, with 4%, to 30% or 40% being the preferred range for HR-flexible foams. The polyol compositions which can be utilized in the present invention can include a variety of compounds and encompass, but are not limited to, the following: (a) alkylene oxide adducts of polyhydroxyalkanes; (b) alkylene oxide adducts of nonreducing sugars and sugar derivatives; and (c) alkylene oxide adducts of polyphenols. Illustrative alkylene oxide adducts of polyhydroxyalkanes include, among others, the alkylene oxide adducts of glycerine, 1,2,4-trihydroxybutane, 1,2,6-trihydroxyhexane, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, pentaerythritol, polycaprolactone, xylitol, arabitol, sorbitol, and mannitol. A further class of polyols which can be employed are the above-mentioned alkylene oxide adducts of the nonreducing sugars, wherein the alkylene oxides have from 2 to 4 carbon atoms. Among the nonreducing sugars and sugar derivatives contemplated are sucrose, alkyl glycosides such as methyl glucoside, and ethyl glucoside; glycol glycosides such as ethylene glycol glycoside, propylene glycol glycoside, glycerol glucoside, and 1,2,6-hexanetriol glycoside, as well as the alkylene oxide adducts of the alkyl glycosides as set forth in U.S.-A-3,073,788. A still further useful class of polyols as indicated in (c) above, is the polyphenols, and preferably the alkylene oxide adducts thereof wherein the alkylene oxides have from 2 to 4 carbon atoms. Among the polyphenols which are contemplated are, for example, condensation products of phenol and formaldehyde, and novolac resins; condensation products of various phenolic compounds and acrolein, the simplest member of this class being 1,2,3-tris(hydroxyphenyl) propanes; condensation products of various phenolic compounds and glyoxal, gluteraldehyde, and other dialdehydes, the simplest members of this class being the 1,1,2,2-tretrakis(hydroxyphenol)ethanes . The alkylene oxide adducts of phosphorus and polyphosphorus acids are another useful class of polyols. Ethylene oxide, 1,2-epoxypropane, the epoxybutanes, and 3-chloro-1,2-epoxypropane are preferred alkylene oxides. Phosphoric acid, phosphorus acid, the polymetaphosphoric acids such as tripolyphosphoric acid, and the polymetaphosphoric acids, are desirable for use in this connection. Indeed, any material having an active hydrogen as determined by the Zerewitinoff test may be utilized as a component of the polyol. For example, amine-terminated polyether polyols are known and may be utilized, if desired. Table VIII contains an example in which an amine terminated polyether polyol is employed. The most preferred polyols employed in this invention include the poly(oxypropylene-oxyethylene) glycols. Ethylene oxide, when used, can be incorporated in any fashion along the polymer chain. Stated another way, the ethylene oxide can be incorporated either in internal blocks, as terminal blocks, or may be randomly distributed along the polyol chain. In addition to the aforementioned poly(alkylene oxide) components, the polyol composition may contain hydroxyl terminated polybutadiene. Also, addition of minor amounts of an alkenoic acid grafted polyalkylene oxide polyether may be employed to aid in reactivity control and cell opening. Examples of the use of these compounds can also be found in Table VIII. The grafted acid is preferably present in an amount of from 0.01 to 2 percent based on the total weight of polymer polyol. The production of stably dispersed polymers within polyols to make polymer polyols is known in the art. The basic patents in the field are Stamberger Re. 28,715 (reissue of U.S. 3,383,351) and Re. 29,118 (reissue of U.S. 3,304,273). Such compositions can be produced by polymerizing one or more ethylenically unsaturated monomers dissolved or dispersed in a polyol in the presence of a free radical catalyst to form a stable dispersion of polymer particles in the polyol. These polymer polyol compositions have the valuable property of imparting to polyurethane foams produced therefrom higher load-bearing properties than are provided by the corresponding unmodified polyols. Also included are the polyols like those taught in U.S. Patent Nos. 3,325,421 and 4,374,209. A wide variety of monomers may be utilized in the preparation of the polymer polyol compositions in accordance with the invention. Numerous ethylenically unsaturated monomers are disclosed in the prior patents. Any of these monomers are suitable. More recently, polyurea and polyurethane suspension polymers have also been utilized. The selection of the monomer or monomers used will depend on considerations such as the relative costs of the monomers and the polyurethane product characteristics required for the intended application. To impart the desired load-bearing to the foams, the monomer or monomers used in preparing the polymer polyol should, of course, desirably be selected to provide a polymer which has a glass transition of at least slightly higher than room temperature. Exemplary monomers include styrene and its derivatives such as para-methylstyrene, acrylates, methacrylates such as methyl methacrylate, acrylonitrile and other nitrile derivatives such as methacrylonitrile. Vinylidene chloride may also be employed. The preferred monomer mixtures used to make the polymer polyol compositions are mixtures of acrylonitile and styrene or acrylonitrile, styrene and vinylidene chloride. The monomer content will be typically selected to provide the desired solids content required for the anticipated end-use application. For typical HR foam fomulations, solids content of up to 50 weight percent are feasible and may be utilized. Crosslinker/Extender A low molecular weight polyfunctional glycolamine crosslinker/extender is preferred to make stable, free-rise foams under the conditions of this invention. Diethanolamine is the most commonly used commercial crosslinker and is the preferred compound of choice. Its use at levels of from 0 to 5 php, which is much broader than what is commercially used, i.e., 0.6 to 1.5 php, is facilitated by the polymer polyol compositions described herein, and this provides for substantially broader load control. Blends of other crosslinkers with diethanolamine can also provide similar advantages. Though diethanolamine is preferred, other crosslinkers, such as, glycerine, triethanolamine, sorbitol and many other low molecular weight polyfunctional hydroxy and/or amine compounds can be sustituted for diethanolamine if desired. Catalysts Any of a large number of polyurethane catalysts may be utilized for producing the polyurethane foam. Typical levels are from 0.001 to 2 php. Representative catalysts include: (a) tertiary amines such as bis(2,2′-dimethylamino)ethyl ether, trimethylamine, triethylamine, N-methylmorpholine, N,N-ethylmorpholine, N,N-dimethylbenzylamine, N,N-dimethylethanolamine, N,N,N′,N′-tetramethyl-1,3-butanediamine, pentamethyldipropylenetriamine, triethanolamine, triethylenediamine, pyridine oxide; (b) strong bases such as alkali and alkaline earth metal hydroxides, alkoxides, and phenoxides; (c) acidic metal salts of strong acids such as ferric chloride, stannous chloride antimony trichloride, bismuth nitrate and chloride; (d) chelates of various metals such as those which can be obtained from acetylacetone, benzoylacetone, trifluoroacetylacetone, ethyl acetoacetate, salicylaldehyde, cyclopentanone-2-carboxylate, acetylacetoneimine, bis-acetylaceonealkylenediimines, salicylaldehydeimine, with the various metals such as Be, Mg, Zn, Cd, Pb, Ti, Zr, Sn, As, Bi, Cr, Mo, Mn, Fe, Co, Ni, or such ions as Mo0₂²⁺, U0₂²⁺; (f) alcoholates and phenolates of various metals such as Ti(OR)₄, Sn(OR)₄, Sn(OR)₂, Al(OR)₃, wherein R is alkyl or aryl, an the reaction products of alcoholates with carboxylic acids, beta-diketones, and 2-(N,N-dialkylamino)alkanols, such as the well known chelates of titanium obtained by this or equivalent procedures; (g) salts of organic acids with a variety of metals such as alkali metals, alkaline earth metals, Al, Sn, Pb, Mn, Co, Bi, and Cu, including, for example, sodium acetate, potassium laurate, calcium hexanoate, stannous acetate, stannous octoate, stannous oleate, lead octoate, metallic driers such as manganese and cobalt naphthenate; (h) organometallic derivatives of tetravalent tin, trivalent and pentavalent As, Sb, and Bi, and metal carbonyls of iron and cobalt. Among the organotin compounds that deserve particular mention are dialkyltin salts of carboxylic acids, e.g., dibutyltin diacetate, dibutyltin dilaureate, dibutyltin maleate, dilauryltin diacetate, dioctyltin diacetate, dibutyltin-bis(4-methylaminobenzoate), dibuytyltindilaurylmercaptide, dibutyltin-bis(6-methylaminocaproate). Similarly, there may be used a trialkyltin hydroxide, dialkyltin oxide, dialkyltin dialkoxide, or dialkyltin dichloride. Examples of these compounds include trimethyltin hydroxide, tributyltin hydroxide, trioctyltin hydroxide, dibutyltin oxide, dioctyltin oxide, dilauryltin oxide, dibutyltinbis(isopropoxide) dibutyltin-bis(2-dimethylaminopentylate), dibutyltin dichloride, dioctyltin dichloride. Stabilizers It is also within the scope of the invention to employ, when applicable, small amounts, e.g., 0.001 percent to 5 percent by weight, based on the total reaction mixture, of a foam stabilizer. Suitable foam stabilizers or surfactants are known and may vary depending upon the particular polyurethane application. Suitable stabilizers for slabstock applications include "hydrolyzable" polysiloxane-polyoxyalkylene block copolymers such as the block copolymers described in U.S. - A - 2,834,748 and 2,917,480. Another useful class of foam stabilizers are the "non-hydrolyzable" polysiloxane-polyoxyalkylene block copolymers such as the block copolymers described in U.S. - A - 3,505,377 and 3,686,254 and G.B. - A - 1,220,471. The latter class of copolymers differs from the above-mentioned polysiloxane-polyoxyalklylene block copolymers in that the polysiloxane moiety is bonded to the polyoxy-alkylene moiety through direct carbon-to-silicon bonds, rather than through carbon-to-oxygen-to-silicon bonds. These various polysiloxane-polyoxyalkylene block copolymers preferably contain from 5 to 50 weight percent of polysiloxane polymer, with the remainder being polyoxyalkylene polymer. Yet another useful class of foam stabilizer is composed of the cyanoalkyl-polysiloxanes described in U.S. - A - 3,905,924. Although it is not required, a polyethersilicone copolymer with mixed hydroxy and methoxy capping of the polyether as described in U.S. - A - 4,690,955 is preferred over less stabilizing HR surfactants to counteract destabilization from the subsidiary polyol in the polymer polyol compositions of the present invention. Polyisocyanates Another advantage of this invention is the wide latitude for varying the isocyanate index and still make stable foams with low shrinkage. Examples are provided (Table III) in which the 80/20 TDI index is varied between 90 and 120 for free rise foams. Commercial production with current polymer polyols ranges from 100 to 115 index. The expanded load latitude offered by the expanded index range is clearly evident from the examples provided. The organic polyisocyanates that are useful in producing polyurethane foam in accordance with this invention are organic compounds that contain at least two isocyanate groups. Such compounds are well known in the art. Suitable organic polyisocyanates include the hydrocarbon diisocyanates (e.g., the alkylene diisocyanates and the aryl diisocyanates, as well as known triisocyanates and polymethylene poly(phenylene isocyanates). Examples of suitable polyisocyanates are 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, methylene bis(4-cyclohexylisocyanate), 1,8-diisocyanatooctane, 1,5-diisocyanato-2,2,4-trimethylpentane, 1,9-diisocyanatononane, 1,10-diisocyanatopropylether of 1,4-butylene glycol, 1,11-diisocyanatoundecane, 1,12-diisocyanatododecane bis(isocyanatohexyl) sulfide, 1,4-diisocyanatobenzene, 3,5-diisocyanato-o-xylene, 4,6-diisocyanato-m-xylene, 2,6-diisocyanato-p-xylene, 2,4-diisocyanato-1-chlorobenzene, 2,4-diisocyanato-1-nitrobenzene, 2,5-diisocyanate-1-nitrobenzene, 4,4-'diphenylmethylene diisocyanate, 2,4'-diphenylmethylene diisocyanate, and polymethylene poly(phenyleneisocyanates), and mixtures thereof. The preferred polyisocyanate is 80/20 TDI (a mixture of 80% 2,4-toluene diisocyanate and 20% 2,6-toluene diisocyanate). Blowing Agents Water can be used in an amount from about 1.0 to about 5.0 php, and preferably between 1.5 and 4.0 php, to produce carbon dioxide by reaction with isocyanate and thus act as the blowing agent for the foam. Additionally, a combination of water and other blowing agents may be employed. Illustrative polyurethane blowing agents include halogenated hydrocarbons such as trichloromonofluoromethane, dichlorodifluoromethane, dichloromonofluoromethane, dichloromethane, trichloromethane, 1,1-dichloro-1-fluoroethane, 1,1,2-trichloro-1,2,2-trifluoroethane, hexafluorocyclobutane, octafluorocyclobutane, and the like. However, as indicated previously, one of the advantages of the present invention is that the use of fluorocarbon blowing agents can be avoided or at least minimized in the foam formulation. Another class of blowing agents include thermally unstable compounds which liberate gases upon heating such as N,N′-dimethyl-N,N′-dinitrosoterephthalamide, amine formates, and formic acid. The preferred method of foaming for producing flexible foams is the use of water, or a combination of water plus a fluorocarbon blowing agent such as trichloromonofluorocarbon. The quantity of blowing agent employed will vary with factors such as the density desired in the foamed product. Other Additives A variety of additional additives known to those skilled in the art may be incorporated in the foam formulations. These may include flame retardants, colorants, fillers and other materials. So called combustion modified HR foams can be produced with the polymer polyols described in the present invention through the use of dispersed melamine powder and/or flame retardants. In practice, the formulations employed in preparing the foams of this invention are prepared by mixing the aforementioned components in standard foam processing equipment in accordance with techniques known to those skilled in the art. Due to the particular components employed in accordance with the teachings of this invention, a wider latitude is afforded to the operater in controlling the density, load and other physical properties of the resulting foam. For example, in accordance with the invention foams can be prepared utilizing a wider range of water, DEOA and isocyanate formulation variables. The advantages of this flexiblity in foam processing is that expanded density and load grades can be produced. Moreover, softer foams can be made without resorting to the use of fluorocarbons. Also higher load grades can be made without costly low building additives. In one embodiment of this invention, a typical formulation can utilize a polyalkylene oxide polyol or polyol blend containing at least 10% ethylene oxide and having a nominal functionalilty of at least 3.0, and an equivalent weight between 1500 and 3000. The particularly preferred composition is a blend of a high primary hydroxyl ethylene oxide end-caped polyol and a predominantly secondary hydroxyl polyol. Hence, a typical formulation using the blends of the present invention in the preparation of a free-rise slabstock foam is comprised of a combination of the following components which yield a high quality polyurethane foam with stable processing to 5 php water and with wide diethanolamine and index latitude. These components are: (a) 63% of a nominal six functional poly(oxypropylene-oxyethylene) polyol with equivalent weight of about 2000, a primary hydroxyl level greater than 80%, and an ethylene oxide content greater than 15%. 19% of a predominantly secondary hydroxyl poly(oxyethylene-oxypropylene) polyol with nominal functionality of 3, equivalent weight of about 1100, and an internal ethylene oxide content of about 10%. (b) 2% of a predominantly poly(oxyethylene) polyol with nominal functionality of 3 and an equivalent weight of 330. (c) 16% of a styrene/acrylonitrile copolymer stably dispersed within the polyols. (d) Water levels between about 1.5 and about 5 parts per hundred of polymer polyol (php). (e) Diethanolamine levels between about 0.4 and 5 php. (f) Toluene diisocyanate (80/20) at 75 to 125 index(stoichiometry). (g) A blend of bis(2-dimethylaminomethyl)ether and triethylenediamine as the tertiary amine catalyst. (h) Stannous octoate or dibutyltin dilaurate as tin catalyst. (i) A polyether-silicone copolymer type surfactant. (j) The remainder of standard additives, including blowing agents, flame retardants, fillers, colorants, and the like, as appropriate. In one preferred embodiment, the subsidiary polyol is added to the foam formulation as a component separate from the remainder of the polymer polyol. In the examples which follow, various abbreviations have been used to define the components employed in the preparation of the foams. These components are identified as follows: Polyols Polyol A - is a polyalkylene oxide triol (nominal) produced by reaction of propylene oxide with glycerine followed by reaction with ethylene oxide and then capping with propylene oxide to reach an equivalent weight of about 1180. It contains about 10% internal ethylene oxide and has predominantly secondary hydroxyl groups. Polyol B - is a polyalkylene oxide hexol (nominal) produced by reaction of propylene oxide with sorbitol and then end-capping with ethylene oxide. The product contains 16.0% ethylene oxide and has a primary hydroxyl level of about 83%. It has an equivalent weight of about 2000. Polyol C - is similar to Polyol B except it contains about 11% ethylene oxide. Polyol D - is similar to Polyol B except it contains about 23% ethylene oxide. Polyol E - is similar to Polyol B except it contains about 20% ethylene oxide. Polyol F - is a polyalkylene oxide triol produced by reaction of ethylene oxide with glycerine to an equivalent weight of about 330. It is about 90% ethylene oxide. Polyol G - is similar to Polyol F except it has an equivalent weight of about 670. Polyol H - is similar to Polyol F except it has an equivalent weight of about 170. Polyol I - is similar to Polyol F except it has an equivalent weight of about 6700. Polyol J - is a polyalkylene oxide triol produced by reaction of ethylene oxide with a propoxylated glycerine starter to an equivalent weight of about 700. It is about 65% ethylene oxide. Polyol K - is a polyalkylene oxide diol produced by reaction of ethylene oxide to an equivalent weight of about 1700. It is 100% ethylene oxide. Polyol L - is a polyalkylene oxide hexol produced by reaction of ethylene oxide with a propoxylated sorbitol starter to an equivalent weight of about 400. It is about 50% ethylene oxide. Polyol M - is similar to Polyol L except it is ethoxylated to an equivalent weight of about 800. Polyol N - is a 10% graft of acrylic acid on a polyalkylene oxide polymer produced by reacting ethylene/propylene oxide with butanol. Polyol O - is a polyalkylene oxide diol produced by reaction of propylene oxide to an equivalent weight of about 1000. Polyol P - is a polyalkylene oxide diol (nominal) produced by reaction of propylene oxide to an equivalent weight of about 2000. Polyol Q - is a polyalkylene oxide triol (nominal) produced by reacting propylene oxide onto glycerine followed by ethylene oxide (17%) and finally capped with propylene oxide to yield an equivalent weight of about 2000. POLYMER POLYOLS (PP) PP-A - A commercial HR polymer polyol containing about 11% of a styrene acrylonitrile suspension copolymer in a blend of oxyethylene capped poly(oxypropylene) polyols. PP-B - A commercial HR polymer polyol similar to PP-A. PP-C - A polymer polyol consisting of three main components: (1) 15 weight percent of a styrene-acrylonitrile suspension copolymer; (2) 65% of Polyol B; and (3) 20% of Polyol A. PP-D - Similar to PP-C except also containing a trace (about 0.1%) of Polyol N. PP-E - Similar to PP-C except component (3) is replaced with Polyol D. PP-F - A polymer polyol consisting of three main components: (1) 16 weight percent of a styrene-acrylonitrile suspension copolymer; (2) 44 % of Polyol-B; and (3) 40% of a 1600 equivalent weight and nominally three functional polyol prepared by reacting propylene oxide onto glycerine and capping with 16.5% ethylene oxide. PP-G - A polymer polyol consisting of four main components: (1) 16 weight percent of a styrene-acrylonitrile suspension copolymer; (2) 32% of Polyol E; (3) 20% of Polyol A; and (4) 32% of a 2000 equivalent weight and nominally three functional polyol prepared by reacting propylene oxide onto glycerine and capping with 16% ethylene oxide. PP-H -A polymer polyol consisting of four main components: (1) 17 weight percent of a styrene-acrylonitrile suspension coplolymer; (2) 32% of Polyol C; (3) 20% of Polyol A; and (4) 31% of a 1600 equivalent weight and nominally three functional polyol prepared by reacting propylene oxide onto glycerine and capping with 16.5% ethylene oxide. PP-I -A polymer polyol consisting of four main components: (1) 17 weight percent of a styrene-acrylonitrile suspension copolymer; (2) 40% of a 1600 equivalent weight and nominally four functional polyol prepared by reacting propylene oxide onto pentaerythritol and capping with 15% ethylene oxide;(3) 20% of Polyol A; and (4) 23% of a 1600 equivalent weight and nominally three functional polyol prepared by reacting propylene oxide onto glycerine and capping with 16.5% ethylene oxide. PP-J - A polymer polyol consisting of three main components: (1) 18.5 weight percent of a styrene-acrylonitrile suspension copolymer; (2) 59% of Polyol B; and (3) 22.5% of Polyol A. PP-K - A polymer polyol consisting of four main components: (1) 16 weight percent of a styrene-acrylonitrile suspension copolymer; (2) 55% of Polyol E; (3) 19% of Polyol A; and 10% of Polyol O. PP-L -A polymer polyol consisting of three main components: (1) 15 weight percent of a styrene-acrylonitrile-vinylidene chloride suspension terpolymer; (2) 65% of Polyol B; and (3) 20% of Polyol Q. PP-M -A polymer polyol consisting of four main components: (1) 17 weight percent of a styrene-acrylonitrile-vinylidene chloride suspension terpolymer; (2) 31% of Polyol B; (3) 20% of Polyol Q; and (4) 32% of a 1600 equivalent weight and nominally three functional polyol prepared by reacting propylene oxide onto glycerine and capping with 19% ethylene oxide. PP-N -A polymer polyol consisting of four main components: (1) 17 weight percent of a styrene-acrylonitrile-vinylidene chloride suspension terpolymer; (2) 40% of Polyol B; (3) 20% of Polyol Q; and (4) 23% of a 1400 equivalent weight and nominally two functional polyol prepared by reacting propylene oxide onto glycerine and capping with 17% ethylene oxide. PP-O -A polymer polyol consisting of four main components: (1) 17 weight percent of a styrene-acrylonitrile-vinylidene chloride suspension terpolymer; (2) 30% of Polyol B; (3) 20% of Polyol Q; and (4) 33% of a 1600 equivalent weight and nominally three functional polyol prepared by reacting propylene oxide onto glycerine and capping with 19% ethylene oxide. PP-P -A polymer polyol consisting of three main components: (1) 8 weight percent of a styrene-acryolnitrile suspension copolymer; (2) 80% of Polyol B; and (3) 12% of Polyol A. PP-Q -A polymer polyol consisting of three main components: (1) 24 weight percent of a styrene-acrylonitrile suspension copolymer; (2) 40% of Polyol B; and (3) 36% of Polyol A. PP-R -A polymer polyol consisting of four main components: (1) 12 weight percent of a polyurea suspension copolymer; (2) 45% of Polyol B; (3) 20% of Polyol A and (4) 23% of a 1700 equivalent weight and nominally three functional polyol prepared by reacting propylene oxide onto glycerine and capping with 16% ethylene oxide. PP-S - A polymer polyol consisting of four main components: (1) 4 weight percent of a polyurethane suspension copolymer (condensation product of TDI and triethanolamine); (2) 45% of Polyol B; (3) 20% of Polyol A and (4) 31% of a 1600 equivalent weight and nominally three functional polyol prepared by reacting propylene oxide onto glycerine and capping with 15% ethylene oxide. PP-T -A polymer polyol consisting of four main components: (1) 16 weight percent of a styrene-acrylonitrile suspension copolymer; (2) 44% of Polyol B; (3) 20% of Polyol A and (4) 20% of a 2000 equivalent weight and nominally three functional amine terminated polyol prepared by reacting propylene oxide onto glycerine and terminated with an amine. PP-U - A polymer polyol consisting of four main components: (1) 18 weight percent of a styrene-acrylonitrile suspension copolymer; (2) 56% of Polyol B; (3) 23% of Polyol A; and (4) 3% of a 1250 equivalent weight polybutadiene polyol. PP-V -A polymer polyol consisting of three main components: (1) 18 weight percent of a styrene-acrylonitrile suspension copolymer; (2) 49% of Polyol B; and (3) 33% of a 1600 equivalent weight and nominally three functional polyol prepared by reacting propylene oxide onto glycerine and then capping with 19% ethylene oxide. PP-W - A polymer polyol consisting of four main components: (1) 16 weight percent of a styrene-acrylonitrile suspension copolymer; (2) 61% of Polyol B; (3) 20% of Polyol A; and (4) 3% of Polyol P. PP-X -A polymer polyol consisting of four main components: (1) 18 weight percent of a styrene-acrylonitrile suspension copolymer; (2) 56% pf Polyol B; (3) 23% of Polyol A; and (4) 3% of Polyol P. Crosslinkers/Extenders DEOA is diethanolamine. MEOA is methyl(ethanolamine) EOA is mono-ethanolamine Catalysts A-1 is a commercial tertiary amine catalyst sold by Union Carbide Corporation. C-183 is a commercial tertiary amine catalyst sold by Union Carbide Corporation. T-9 and D-19 are predominantly stannous octoate. T-12 and D-22 are predominantly dibutyltin dilaurate. Surfactants SURF-A is an alkoxy capped polyether - silicone copolymer. It is a standard commercial HR surfactant. SURF-B is a polyether - silicone copolymer with mixed hydroxy and methoxy capping. It is slightly more stabilizing than SURF A. SURF-C is a polyether - silicone copolymer with mixed hydroxy and methoxy capping. It is more stabilizing than SURF A. SURF-D is an alkoxy capped polyether - silicone copolymer similar to SURF A. Flame Retardants T-101 (Thermolin 101) is a commercial organo(chlorophosphate) flame retardant sold by the Olin Corporation. DE-60F Special is a commercial flame retardant composed of a brominated aromatic compound and an organo(chlorophosphate) sold by Great Lakes Chemical Co. CEF is a commercial organo(chorophosphate) flame retardant sold by Stauffer Corporation. Blowing Agents F-11C is essentially trichlorofluoromethane (fluorocarbon 11). Diisocyanate INDEX is the percentage of the calculated stoichiometric amount of TDI needed to react with active hydrogen components in the formulation and represents the stoichiometric amount of TDI used. For example, Index of 110 indicates 110% of the stoichiometric amound of TDI was used. If not specified in the Tables, Index refers to the amount of 80/20 TDI that was used. 80/20 TDI is a mixture of 80% of 2,4-toluenediisocyanate and 20% 2,6-toluenediioscyanate. 65/35 TDI is a mixture of 65% of 2,4-toluenediisocyanate and 35% 2,6-toluenediioscyanate. Processing and Physical Property Terms Cream Time is the time from mixing TDI with the other components until a noticeable expansion of the foam mixture occurs. Rise Time is the time from mixing TDI with the other components until a visible blow-off of gas occurs at near full rise of the foam. Percent Settle is the percentage of height loss (from the maximum foam height) at the five minute point after TDI addition to the other components. Shrinkage is an indication of the amount of foam shrinkage that occurs during cooling of the foam. Moderate shrinkage is considered unacceptable for processing. Porosity is a measure of the air flow rate in m³.min⁻¹.m⁻² (cubic feet per minute per square foot) through a slice of the foam after crushing to open cell windows. Measurements per Standard Methods Density - kg/m³ (pounds per cubic foot). Resiliency - per cent ball rebound IFD 25% (25% IFD) - load (indentation force deflection) at 25% compression in MPa (pounds per 50 square inches). IFD 65% (65% IFD) - load (indentation force deflection) at 65% compression in MPa (pounds per 50 square inches). Examples 1 - 59 In the examples which follow, bench scale foams (Examples 1-51) were prepared by weighing together all of the formulation ingredients except TDI and stannous octoate catalyst (if used) into a 1.891 or 3.7851 (one half or one gallon) paper can, then mixing at 2400 rpm for 15 seconds using a drill press equipped with a bladed agitator. A baffle is inserted into the paper can and mixing is resumed for 60 seconds. Then the mixture is allowed to stand for 15 seconds during which time stannous octoate is added (if used). Mixing is resumed for 15 seconds with the isocyanate being added with seven seconds left in this period. This complete mixture is quickly poured into a 356 x 356 x 152mm (14 x 14 x 6") "cake" box and allowed to foam. The profile and settle are recorded for five minutes and then the foam is placed in a forced air oven at 125°C for five minutes. After removing from the oven, the foam is allowed to cure at ambient conditions, for at least 16 hours. Indications of foam shrinkage are noted after this period and then the foam is cut to 305 x 305 x 102 (12 x 12 x 4") for physical property measurements. Machine foams (Examples 52-59) were prepared using a pilot scale low pressure conventional slabstock foam machine. A premix was made of all the components except TDI and stannous octoate (when used), these being injected along with the premix through separate streams to the mixhead. Slabstock buns were made having cross sections of about 914mm (36 inches) wide by 457 to 610mm (18 to 24 inches) high. Test specimens 381 x 381 x 102mm (15 x 15 x 4") were cut from the center of each bun. All of the samples were evaluated in accordance with tests normally employed in the industry. The results are set forth in Tables I-X below. It is readily evident from the data set forth in the preceding tables that the use of the polymer polyol compositions of the present invention provide wider formulating and processing latitude in the preparation of polyurethane foams. Examples 1-8; Table I . These examples compare the DEOA latitude offered by a polymer polyol of this invention with two commercial HR polymer polyols in the bench scale production of 25.6 kg/m³ (1.6 pcf) water blown free-rise foams. The commercial polyols collapse at DEOA levels below about 0.8 php and exhibit unacceptable shrinkage at high levels (1.25 php in the case of PP-B). The preferred polymer polyol exhibits stable foam with low shrinkage from 0.6 php to 3 php DEOA. Examples 9-14; Table II . These examples demonstrate the improved stability at high water levels (4.5-5 php) for polymer polyols of the present invention relative to commercial polymer polyols. Examples 15-20; Table III. Loads (25% IFD) between 12 and 55 lbs/50 sq. in. and densities between 20.5 and 44.8 kg/m³ (1.28 and 2.8 pcf) are produced with the polymer polyols of this invention without load builders or physical blowing agents. Current production with HR slabstock polymer polyols ranges from about 6.9 to 12.1 MPa (20 to 35 lbs/50 sq. in.) and density above about 28.8 kg/m³ (1.8). Examples 21-44; Tables IV-VII. These examples show modifications to the components of the polymer polyols of this invention and further demonstrate the breadth of the useful compositions. Examples 45-51; Tables VIII and IX. These examples also provide modification of the technology and further demonstrate the breadth of useful foam compositions. Examples 52-59; Table X. These examples demonstrate that the advantages obtained on the bench scale processing of the preceding examples, can be scaled up to maching foam processing.

Claims: Claims for the following Contracting States : AT, BE, CH, DE, FR, GB, GR, IT, LI, LU, NL, SE A polymer polyol useful in the preparation of flexible polyurethane foams and which affords enhanced latitude for varying formulation components to make foams with broad load and density ranges, said polymer polyol comprising: (a) a high functionality polyalkylene oxide polyol, or a blend of such polyols, with an equivalent weight between 1000 and 3000, an ethylene oxide content between 8 and 25% and an average nominal functionality of at least 3, said polyol or polyol blend being present in an amount of from 30 to 90 weight percent of the polymer polyol; (b) a subsidiary polyalkylene oxide polyol with a molecular weight between 450 and 30000 and having a poly (oxyethylene) content greater than 30%, said polyalkylene oxide polyol being present in an amount of from 1 to 20 weight percent based on the polymer polyol; the average nominal functionality of the mixture of (a) and (b) being at least 3.0; and (c) a stably dispersed polymer formed in situ by polymerization of low molecular weight compounds within the mixture of (a) and (b) or within one or more of the components of (a) and/or (b); wherein the polymer is present in an amount of from 2 to 50 weight percent of the polymer polyol. The polymer polyol of claim 1 wherein the high functionality polyol or polyol blend (a) is present in an amount of from 40 to 90 weight percent of the polymer polyol; and the average nominal functionality of (a) + (b) is from 3.2 to 6; The polymer polyol of claim 1 or claim 2 wherein the high functionality polyol is a poly (oxyethylene-oxypropylene) copolymer. The polymer polyol of claim 3 wherein said copolymer has an equivalent weight of from 1600 to 2200. The polymer polyol of any one of claims 1 to 4 wherein the subsidiary polyol is a poly(oxyethylene-oxypropylene) copolymer. The polymer polyol of claim 5 wherein the subsidiary polyalkylene oxide is comprised of at least 50 percent by weight of poly(oxyethylene). The polymer polyol of any one of claims 1 to 6 wherein the subsidiary polyalkylene oxide has a molecular weight between 450 and 2000. The polymer polyol of any one of claims 1 to 7 wherein the subsidiary polyalkylene oxide is present in the polymer polyol in an amount of from 1 to 10 weight percent of the polymer polyol. The polymer polyol of claim 1 wherein said subsidiary polyalkylene oxide has a functionality between 2 and 8. The polymer polyol or any one of claims 1 to 9 wherein the stably dispersed polymer is present in an amount of from 4 to 40 weight percent of the polymer polyol. The polymer polyol of any one of claims 1 to 10 wherein at least one of the high functionality polyol and the subsidiary polyol includes a compound, other than a polyol, containing active (Zerewitinoff) hydrogen. A polymer as claimed in claim 11 wherein said compound is an amino compound obtained by terminating a polyether polyol with amine. The polymer polyol of any one of claims 1 to 12 which contains a minor amount of an alkenoic acid grafted polyalkylene oxide. The polymer polyol of claim 13 wherein the alkenoic acid is acrylic acid. The polymer polyol of claim 13 or 14 wherein the grafted alkenoic acid is present in an amount of from 0.01 to 2 percent based on the total weight of the polymer polyol. The use of the polymer polyol of any one claims 1 to 15 for the production of a flexible polyurethane foam which affords enhanced latitude for varying formulation components to make foams with a broad load and density range. The use of the polymer polyol of claim 16 together with water in an amount between 1.0 and 5.0, preferably between 1.5 and 4.0, parts per hundred parts of polyol. The use of the polymer polyol of claim 16 or claim 17 wherein the subsidiary polyol is added to the foam formulation as a component separate from the remainder of the polymer polyol. A flexible polyurethane foam prepared according to any one of claims 16 to 18. Claims for the following Contracting State : ES A polymer polyol useful in the preparation of flexible polyurethane foams and which affords enhanced latitude for varying formulation components to make foams with broad load and density ranges, said polymer polyol comprising: (a) a high functionality polyalkylene oxide polyol, or a blend of such polyols, with an equivalent weight between 1000 and 3000, an ethylene oxide content between 8 and 25% and an average nominal functionality of at least 3, said polyol or polyol blend being present in an amount of from 30 to 90 weight percent of the polymer polyol; (b) a subsidiary polyalkylene oxide polyol with a molecular weight between 450 and 30000 and having a poly (oxyethylene) content greater than 30%, said polyalkylene oxide polyol being present in an amount of from 1 to 20 weight percent based on the polymer polyol; the average nominal functionality of the mixture of (a) and (b) being at least 3.0; and (c) a stably dispersed polymer formed in situ by polymerization of low molecular weight compounds within the mixture of (a) and (b) or within one or more of the components of (a) and/or (b); wherein the polymer is present in an amount of from 2 to 50 weight percent of the polymer polyol. The polymer polyol of claim 1 wherein the high functionality polyol or polyol blend (a) is present in an amount of from 40 to 90 weight percent of the polymer polyol; and the average nominal functionality of (a) + (b) is from 3.2 to 6; The polymer polyol of claim 1 or claim 2 wherein the high functionality polyol is a poly (oxyethylene-oxypropylene) copolymer. The polymer polyol of claim 3 wherein said copolymer has an equivalent weight of from 1600 to 2200. The polymer polyol of any one of claims 1 to 4 wherein the subsidiary polyol is a poly(oxyethylene-oxypropylene) copolymer. The polymer polyol of claim 5 wherein the subsidiary polyalkylene oxide is comprised of at least 50 percent by weight of poly(oxyethylene). The polymer polyol of any one of claims 1 to 6 wherein the subsidiary polyalkylene oxide has a molecular weight between 450 and 2000. The polymer polyol of any one of claims 1 to 7 wherein the subsidiary polyalkylene oxide is present in the polymer polyol in an amount of from 1 to 10 weight percent of the polymer polyol. The polymer polyol of claim 1 wherein said subsidiary polyalkylene oxide has a functionality between 2 and 8. The polymer polyol or any one of claims 1 to 9 wherein the stably dispersed polymer is present in an amount of from 4 to 40 weight percent of the polymer polyol. The polymer polyol of any one of claims 1 to 10 wherein at least one of the high functionality polyol and the subsidiary polyol includes a compound, other than a polyol, containing active (Zerewitinoff) hydrogen. A polymer as claimed in claim 11 wherein said compound is an amino compound obtained by terminating a polyether polyol with amine. The polymer polyol of any one of claims 1 to 12 which contains a minor amount of an alkenoic acid grafted polyalkylene oxide. The polymer polyol of claim 13 wherein the alkenoic acid is acrylic acid. The polymer polyol of claim 13 or 14 wherein the grafted alkenoic acid is present in an amount of from 0.01 to 2 percent based on the total weight of the polymer polyol. The use of the polymer polyol of any one claims 1 to 15 for the production of a flexible polyurethane foam which affords enhanced latitude for varying formulation components to make foams with a broad load and density range. The use of the polymer polyol of claim 16 together with water in an amount between 1.0 and 5.0, preferably between 1.5 and 4.0, parts per hundred parts of polyol. The use of the polymer polyol of claim 16 or claim 17 wherein the subsidiary polyol is added to the foam formulation as a component separate from the remainder of the polymer polyol. A flexible polyurethane foam prepared according to any one of claims 16 to 18. A method of forming a polymer polyol as claimed in any one of claims 1 to 15 said method comprising forming a stable dispersion of a polymer in a mixture of polyols comprising (a) said high functionality polyalkylene oxide polyol or blend of such polyols, having an equivalent weight between 1000 and 3000, an ethylene oxide content between 8 and 25% and an average nominal functionality of at least 3, and (b) said subsidiary polyalkylene oxide polyol having a molecular weight between 450 and 30000 and a poly (oxyethylene) content greater than 30%, by polymerization of low molecular weight compounds in situ within the mixture of (a) and (b) or within one or more of the components of (a) and/or (b); said polymer forming from 2 to 50 weight percent of the polymer polyol, said polyol or polyol blend forming from 30 to 90 weight percent of the polymer polyol, said subsidiary polyol forming 1 to 20 weight percent of the polymer polyol and the average functionality of (a) and (b) being at least 3.0. A method of forming a flexible polyurethane foam by reaction of a polyisocyanate with a polyol in the presence of a blowing agent wherein the polyol comprises polymer polyol as claimed in any one of claims 1 to 15 or obtained by the method of claim 20. A method as claimed in claim 21 in which the blowing agent includes water in an amount of between 1.0 and 5.0, preferably between 1.5 and 4.0, parts per hundred parts of the polymer polyol. A method as claimed in claim 21 or claim 22 wherein the subsidiary polyol is added to the foam formulation as a component separate from the remainder of the polymer polyol.

Inventors: HAGER STANLEY LEE, HAGER, STANLEY LEE
Applicants: ARCO CHEM TECH, ARCO CHEMICAL TECHNOLOGY, L.P.
Application year: 1989
Main classification: C08G18
IPC codes: C08G18, C08L71