MXPA97007497A - Foamed polymer and process for your producc - Google Patents

Abstract

A foamed isocyanate-based polymer having a cellular structure and containing a superabsorbent material, the polymer being capable of: (i) absorbing at least about 20 times its weight of an aqueous fluid maintained at a temperature of about 20øC to about 25øC, and (ii) retaining at least about 20 times its weight of the absorbed aqueous fluid that is bonded to the superabsorbent material. A process for producing a foamed isocyanate-based polymer, which comprises the steps of: providing a substantially uniform mixture comprising an isocyanate, an active hydrogen-containing compound, and a superabsorbent material, the superabsorbent material being capable of absorbing at least about 20 times its weight of an aqueous fluid maintained at a temperature in the range of about 20øC to about 25øC, add an aqueous blowing agent and a catalyst to the substantially uniform mixture to form a reaction mixture, and expand the reaction mixture to producing the foamed isocyanate-based polymer, wherein the active hydrogen-containing compound comprises from about 10 percent to 100 percent by weight of a compound containing hydrophilic active hydrogen, and from 0 to about 90 percent by weight of a compound containing nonhydrophilic active hydrogen. The foamed isocyanate-based polymer is ideally suited for use in an absorption layer of a personal hygiene device.

Description

FOAM POLYMER AND PROCESS FOR ITS PRODUCTION TECHNICAL FIELD The present invention relates to a foamed polymer and to a process for its production. More particularly, the present invention relates to a foamed isocyanate-based polymer (e.g., polyurethane foam, polyurea foam, polyisocyanurate foam, etc.), and to a process for its production.

BACKGROUND TECHNIQUE Isocyanate-based polymers are known in the art. In general, those skilled in the art understand that isocyanate-based polymers are polyurethanes, polyureas, polyisocyanurates, and mixtures thereof. The production of foamed isocyanate-based polymers is also known in the art. Actually, one of the advantages of isocyanate-based polymers, compared to other polymer systems, is that chemistry can be used to achieve the desired properties of the product on the site. One of the conventional ways to produce a polyurethane foam is known as the "one shot" technique. In this technique, the isocyanate, a suitable polyol, a catalyst, water (which acts as a primary blowing agent and optionally can be supplemented with one or more secondary organic blowing agents), and other additives, are mixed together using, for example, a mechanical or impact mixer. In general, if a polyurea were to be produced, the polyol would be replaced with a suitable polyamine. A polyisocyanurate can result from the cyclotrimerization of the isocyanate component. Polyureas or urethane-modified polyisocyanurates are known in the art. In any area, the reagents would mix intimately quickly using a suitable mixer. Another technique for producing foamed isocyanate-based polymers is known as the "prepolymer" technique. In this technique, a polyol and isocyanate prepolymer (in the case of a polyurethane) is reacted under an inert atmosphere to form a liquid polymer terminated with isocyanate groups. To produce the foamed polymer, the prepolymer is mixed thoroughly with water and a polyol (in the case of producing a polyurethane) or a polyamine (in the case of producing a polyurea) in the presence of a catalyst or a crosslinker. In certain cases, the foamed polymer can be produced by reaction of the prepolymer with water and catalyst. As is known to those skilled in the art, many conventional isocyanate-based foams are non-hydrophilic (ie, relatively hydrophobic). These foams generally have an aversion to aqueous fluids. Practically, this results in these foams being unable to absorb or collect significant quantities of aqueous fluids (eg, the foams will float on the water) other than by mechanical introduction. In accordance with the above, these foams are virtually never used in an application where a desired characteristic is a significant aqueous fluid absorption. Heretofore, the prior art has been dedicated to producing hydrophilic isocyanate-based foams (ie, foams that are capable of absorbing or collecting significant quantities of aqueous fluids) employing two general approaches. The first approach has been to impart hydrophilicity to an otherwise hydrophobic foam, by using a compound containing specific active hydrogen (eg, polyol in the case of polyurethane) and / or other additive to the reaction system. For example, it is known that the use of a polyol commercially available from Olin Corporation under the trademark POLY-G-X-609® in a otherwise conventional formulation will result in the production of a hydrophilic polyurethane foam. See also, for other examples of this approach, U.S. Patent Nos. 3,781,231 (Jansen et al.) And 3,799,898 (Lamplugh et al.) And British Patent Number 1,354,576 (Fritz Nauer &; Co.), incorporating the contents of each one as a reference. The resulting foam is hydrophilic in the sense that it will absorb or collect an aqueous fluid (for example, when the foam is immersed in a body of water, it will submerge at least partially or completely). However, the resulting foam is unable to retain substantial amounts of any aqueous fluid absorbed or collected (for example, in the previous example, when the foam is removed at least partially or totally submerged from the body of water, the absorbed water will immediately begin to drain from the foam matrix). The result of this is that, the previously known hydrophilic foams produced in accordance with the first approach, are unsuitable for use in applications where absorption and retention of an aqueous fluid is required (e.g., disposable diapers, disposable training pants, towels sanitary, incontinence devices, and other personal hygiene products, sponges for general purposes, surgical sponges, absorbent devices for agricultural / horticultural applications, pest control, blocking of chemical spills, and the like). The second approach has been to combine a non-hydrophilic (ie, relatively hydrophobic) isocyanate-based foam with a superabsorbent material. In general, a material is considered superabsorbent if it absorbs a multiple of its weight of a fluid. Accordingly, most known superabsorbent materials are capable of absorbing at least about 10 times, preferably at least about 20 times their weight of an aqueous fluid. For examples of this approach, see U.S. Patent Nos. 3,900,030; 4,394,930 (Korpman), 4,731,391 (Garvey), and 4,985,467 (Kelly et al.), And published Japanese patent applications numbers 55 / 168,104 and 57 / 92,032, the contents of each being incorporated herein by reference. A general drawback of this approach is that the absorption of the aqueous fluid occurs initially through the surface of the foam, the superabsorbent material thereof expands, thereby retarding the migration of the fluid into the foam, with the result that the amount of absorption or collection of aqueous fluid is limited in a significant way. The main reason for this phenomenon is that the foam matrix has a cellular structure that has cells that are closed (this inhibits the absorption of fluid) or open (this allows the absorption of fluid). As is known in the art, an open cell structure is one in which an open cellular structure is maintained by virtue of providing fissures or cracks in the windows between the struts of the cells. Fissures or cracks result in cells that are effectively interconnected with respect to absorption or collection of fluid. Kelly and colleagues are notable, as they are dedicated to overcoming the general drawback of this approach discussed above. Specifically, the novelty sought in Kelly et al. Is to produce a cellular structure that contains the superabsorbent material, and subject it to a process of thermal crosslinking, with the result that the windows are completely destroyed between the props of a conventional cellular structure (closed or open), allowing better access of the fluid to the interior of the foam. As is known in the art, crosslinking is a further processing step that will add potential variability to the overall process. A disadvantage of Kelly et al. Is that, in exchange for an extra complicated and costly process step, the gain in absorption or in fluid collection is relatively modest at best, and only in certain loads of superabsorbent material. In light of these difficulties in the prior art, it would be convenient to have a foamed isocyanate-based polymer that is hydrophilic and capable of retaining a substantial amount of aqueous fluid that is absorbed or collected. It would also be convenient if this foam could be produced in a relatively uncomplicated manner, and that it possesses generally reproducible physical properties.

DESCRIPTION OF THE INVENTION It is an object of the present invention to provide a novel foamed isocyanate-based polymer that obviates or mitigates one or more of the previously identified deficiencies of the prior art. It is an object of the present invention to provide a novel process for producing this foamed isocyanate-based polymer. It is another object of the present invention to provide a novel personal hygiene device incorporating this foamed isocyanate-based polymer. According to the above, in one of its aspects, the present invention provides a foamed isocyanate-based polymer having a cellular structure and comprising a superabsorbent material, the polymer being capable of: (i) absorbing at least about 20 times its weight of an aqueous fluid maintained at a temperature of about 20 ° C to about 25 ° C; and (ii) retaining at least about 20 times its weight of absorbed aqueous fluid which is bound to the superabsorbent material. In another of its aspects, the present invention provides a foamed polyurethane polymer comprising poly (alkali metal salt of acrylic acid) in an amount on the scale of about 55 to about 65 parts by weight of polyol used to produce the polymer of polyurethane foam, the polymer being able to: (i) absorb from about 35 to about 65 times its weight of an aqueous fluid maintained at a temperature from about 20 ° C to about 25 ° C, and (ii) retain from about 30 to about about 55 times its weight of absorbed aqueous fluid that binds to the poly (alkali metal salt of acrylic acid). In yet another of its aspects, the present invention provides a process for producing a foamed isocyanate-based polymer, which comprises the steps of: providing a substantially uniform mixture comprising an isocyanate, an active hydrogen-containing compound, and a superabsorbent material , the superabsorbent material being able to absorb at least about times its weight of an aqueous fluid maintained at a temperature in the range of about 20 ° C to about 25 ° C; adding an aqueous blowing agent and a catalyst to the substantially uniform mixture to form a reaction mixture; and expanding the reaction mixture to produce the foamed isocyanate-based polymer; wherein the active hydrogen-containing compound comprises from about 10 percent to 100 percent by weight of a compound containing hydrophilic active hydrogen, and from 0 to about 90 percent by weight of a compound containing non-hydrophilic active hydrogen . In an alternative embodiment of the present process, a process for producing a foamed isocyanate-based polymer is provided, which comprises the steps of: providing a substantially uniform mixture comprising an aqueous blowing agent, a catalyst, an active hydrogen-containing compound , and a superabsorbent material, the superabsorbent material being capable of absorbing at least about 20 times its weight of an aqueous fluid maintained at a temperature in the range of about 20 ° C to about 25 ° C; adding an isocyanate to the substantially uniform mixture to form a reaction mixture; and expanding the reaction mixture to produce the foamed isocyanate-based polymer; wherein the active hydrogen-containing compound comprises from about 10 percent to 100 percent by weight of a compound containing hydrophilic active hydrogen, and from 0 to about 90 percent by weight of a compound containing non-hydrophilic active hydrogen . When any method of the process for preparing a foamed polyurethane or a foamed urea-modified polyurethane is employed, it is possible, and indeed preferred, to use a single polyol or a mixture of polyols having a total ethylene oxide content in the scale of about 15 to about 80, preferably from about 20 to about 70, more preferably from about 35 to about 70, and most preferably from about 50 to about 65 weight percent, the remainder comprised of other polyoxyalkylene groups such as propylene oxide, butylene oxide, or mixtures thereof. In yet another of its aspects, the present invention provides a personal care device having an absorbent layer of body fluids, consisting essentially of a foamed isocyanate-based polymer having a cellular structure and containing a superabsorbent material, the polymer being capable of: (i) absorbing at least about 20 times its weight of an aqueous fluid maintained at a temperature of about 20 ° C to about 25 ° C, and (ii) retaining at least about 20 times its weight of the absorbed aqueous fluid that It is bonded with the superabsorbent material.

In yet another of its aspects, the present invention provides a personal care device having an absorbent layer of body fluids, consisting essentially of a foamed polyurethane polymer comprising poly (alkali metal salt of acrylic acid) in an amount the scale from about 55 to about 65 parts by weight of polyol used to produce the foamed polyurethane polymer, the polymer being capable of: (i) absorbing from about 35 to about 65 times its weight of an aqueous fluid maintained at a temperature of about 20 ° C to about 25 ° C, and (ii) retaining from about 30 to about 55 times its weight of the absorbed aqueous fluid that binds to the poly (alkali metal salt of acrylic acid). As used throughout this specification, the term "isocyanate-based polymer" is intended to mean, among other things, polyurethane, polyurea, and polyisocyanurate. It has been found that, by combining the reagents necessary to produce a hydrophilic isocyanate-based foam with a superabsorbent material, a superabsorbent foam can be made that has surprising, unexpected, and significantly improved properties of absorption / collection of aqueous fluid ( absorption and recollection terms are used interchangeably throughout the present specification), and withholding. More specifically, many of the present foamed isocyanate-based polymers exhibit synergistic improvements in the absorption and retention properties of the aqueous fluid, compared to hydrophilic foams of the prior art that do not contain superabsorbent material (i.e., the first approach of the prior art discussed above), and with the hydrophobic foams containing superabsorbent materials (ie, the second approach of the prior art discussed above). For the Applicant's knowledge, prior to the present invention, there were no known foamed isocyanate-based polymers having these better water-fluid retention and retention properties. Although applications for this foamed isocyanate-based polymer will be immediately apparent to those skilled in the art, it is believed that the present foamed isocyanate-based polymer is particularly useful in personal hygiene devices, such as disposable diapers, disposable training pants, sanitary napkins, incontinence pads, bandage gauze, and the like. More particularly, it is contemplated that the present foamed isocyanate-based polymer presents a significantly more cost effective alternative to the conventional blends of superabsorbent / pulp material used in current disposable diapers. Significant cost savings are made both in component costs and in reduced equipment costs.

BRIEF DESCRIPTION OF THE DRAWINGS The embodiments of the present invention will be described with reference to the accompanying drawings, in which: Figures 1 and 2 illustrate a graph of fluid absorption versus time for different samples. Figure 3 illustrates the results of a test through the layers for the fluid absorption rate for different samples.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to, among other things, a foamed isocyanate-based polymer comprising a superabsorbent material, and a process for its production. In general, the present foamed isocyanate-based polymer is selected from the group comprising polyurethane foam, polyurea foam, polyisocyanurate foam, urea-modified polyurethane foam, urethane-modified polyurea foam, urethane-modified polyisocyanurate foam , and urea-modified polyisocyanurate foam. The present foamed isocyanate-based polymer is selected from the group consisting of polyurethane foam and urea-modified polyurethane foam. The most preferred isocyanate-based polymer is polyurethane foam. As is known in the art, the term "modified", when used in conjunction with a polyurethane, with a polyurea, or with a polyisocyanate, means that up to 50 percent of the forming bonds of the polymer backbone have been replaced. The first step in the present process comprises providing a substantially uniform mixture comprising an isocyanate, an active hydrogen-containing compound, and a superabsorbent material, the superabsorbent material being capable of absorbing at least about 20 times its weight of an aqueous fluid maintained at a temperature on the scale from about 20 ° C to about 25 ° C. The isocyanate suitable for use in the substantially uniform mixture is not particularly restricted, and its selection is within the scope of a person skilled in the art. In general, the isocyanate compound suitable for use can be represented by the general formula: QINCOJi where i is an integer of 2 or more, and Q is an organic radical having the valence of i. Q can be a substituted or unsubstituted hydrocarbon group (for example, an alkylene or arylene group). Moreover, Q can be represented by the general formula: Q1-Z-Q1 wherein Q1 is an alkylene or arylene group, and Z is selected from the group comprising -O-, -0-Q1-, -CO-, -S-, -S-Q1-S-, and -S02- . Examples of isocyanate compounds that fall within the scope of this definition include hexamethylene diisocyanate, 1,8-diisocyanate-p-methane, xylyl diisocyanate, (OCNCH 2 CH 2 CH 2? CH 2?) 2, 1-methyl-2,4- diisocyanatocyclohexane, phenylene diisocyanates, toluene diisocyanates, chlorophenylene diisocyanates, 4,4 '- diphenylmethane diisocyanate, naphthalene 1,5-diisocyanate, 4,4', 4"-triphenylmethane triisocyanate, and alpha-4-diisocyanate isopropylbenzene In another embodiment, Q may also represent a polyurethane radical having a valence of I. In this case, Q (NC0) i is a compound that is commonly referred to in the art as a prepolymer. can be prepared by reacting a stoichiometric excess of an isocyanate compound (as defined hereinbefore) with a compound containing active hydrogen (as defined hereinbefore), preferably the materials which they contain polyhydroxyl or polyols described below. In this embodiment, the polyisocyanate can be used, for example, in proportions of about 30 percent to about 200 percent stoichiometric excess with respect to the proportion of hydroxyl in the polyol. The prepolymer can then be reacted with a polyol, an aqueous blowing agent (water), a catalyst, and optionally, other additives, to produce a polyurethane foam, or an amine to produce a polyurea modified with polyurea. In another embodiment, the isocyanate compound suitable for use in the process of the present invention may be selected from dimers and trimers of isocyanates and diisocyanates, and from polymeric diisocyanates having the general formula: [Q "(NC0) i] j wherein both i and j are integers having a value of 2 or more, and Q "is a polyfunctional organic radical and / or as additional components in the reaction mixture, the compounds having the general formula: L (NCO) i where i is an integer that has a value of 1 or more, and L is a monofunctional or polyfunctional atom or radical. Examples of the isocyanate compounds that fall within the scope of this definition include ethylphosphonic diisocyanate, phenylphosphonic diisocyanate, compounds containing a group = Si-NCO, diisocyanate compounds derived from sulfonamide (QS02NCO), cyanic acid, and thiocyanic acid . See also, for example, British Patent Number 1,453,258, the contents of which are incorporated herein by reference. Non-limiting examples of suitable isocyanates include 1,6-hexamethylene diisocyanate, 1,4-butylene diisocyanate, furfurylidene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, diisocyanate 2, 4'-diphenylmethane, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyl propane diisocyanate, 4,4-diphenyl-3,3'-dimethylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1-methyl -2,4-diisocyanato-5-chlorobenzene, 2,4-diisocyanato-s-triazine, l-methyl-2,4-diisocyanato-cyclohexane, p-phenylene diisocyanate, m-phenylene diisocyanate, diisocyanate of 1, 4 -naphthalene, dianisidine diisocyanate, bitoluene diisocyanate, 1,4-xylylene diisocyanate, 1-xylylene diisocyanate, bis (4-isocyanatophenyl) methane, bis- (3-methyl-4-isocyanatophenyl) ethane, polymethylene polyphenyl polyisocyanates and mixtures thereof. A more preferred isocyanate is selected from the group comprising 2,4-toluene diisocyanate, 2,46-toluene diisocyanate, and mixtures thereof, for example, a mixture comprising from about 75 to about 85 percent by weight. weight percent 2,4-toluene diisocyanate, and from about 15 to about 25 weight percent diisocyanate 2, 6-toluene. Another more preferred isocyanate is selected from the group comprising 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, and mixtures thereof. The most preferred isocyanate is a mixture comprising from about 15 to about 25 weight percent of 2,4'-diphenylmethane diisocyanate, and from about 75 to about 85 weight percent of 1,4-diisocyanate. '-diphenylmethane. An example of this isocyanate is commercially available from Imperial Chemical Industries, under the trade name Rubinate M, and from The Dow Chemical Company, under the tradename PAPI 4027. The active hydrogen-containing compound used in the uniform mixture comprises about 10%. percent to 100 percent by weight of a compound containing hydrophilic active hydrogen, and from 0 to about 90 percent by weight of a compound containing nonhydrophilic active hydrogen. Preferably, the active hydrogen-containing compound comprises from about 20 percent to about 90 percent, more preferably from about 40 percent to about 90 percent, and most preferably from about 60 percent to about 80 weight percent of a compound containing hydrophilic active hydrogen, and from about 10 percent to about 80 percent, more preferably from about 10 percent to about 60 percent, and most preferably from about 20 percent to about 30 weight percent of a compound containing nonhydrophilic active hydrogen. Preferably, the hydrophilic active hydrogen-containing compound is a hydrophilic polyol. As is known, the term "hydrophilic polyol" is intended to mean a polyol that imparts hydrophilicity to the foam product. Ideally, the hydrophilic polyol has a molecular weight in the range of about 1,500 to about 6,000. Preferably, the hydrophilic polyol is selected from the group consisting of diols, triols, tetroles, and mixtures thereof, each of which contains polyoxyalkylene groups, the polyoxyalkylene groups comprising at least about 25, more preferably about 40 to about 85, and most preferably from about 55 to about 85 weight percent ethylene oxide. As is known in the art, the remaining polyoxyalkylene groups are conventionally formed from one or both of propylene oxide and butylene oxide, preferably only propylene oxide. A particularly preferred hydrophilic polyol is commercially available from The Dow Chemical Company under the tradename CP1421. Another preferred hydrophilic polyol is commercially available from Arco under the trade name Arcol 2580. Still another preferred hydrophilic polyol is commercially available from BASF Corporation under the tradename Pluracol 593. Alternatively, if it is desired to produce a polyurea, the compound containing Active hydrogen can be derived from a hydrophilic polyol as described above, which has been reacted or capped with an amine. This amination within the scope of a person skilled in this field. The nonhydrophilic active hydrogen-containing compound, if present, is selected from the group consisting of non-hydrophilic polyols, polyamines, polyamides, polyimines, polyolamines, and mixtures thereof. If the process is used to produce a polyurethane foam, the non-hydrophilic active hydrogen-containing compound is typically a non-hydrophilic polyol. In general, if this non-hydrophilic polyol contains or is based on ethylene oxide, the ethylene oxide will be present in amounts of less than about 20 weight percent. The selection of this polyol is not particularly restricted, and is within the reach of a person skilled in this field. For example, the polyol can be a hydroxyl terminated compound selected from the group comprising polyether, polyester, polycarbonate, polydiene, and polycaprolactone. The polyol can be selected from the group comprising hydroxyl-terminated polyhydrocarbons, hydroxyl-terminated polyformals, fatty acid triglycerides, hydroxyl-terminated polyesters, hydroxymethyl-terminated polyesters, hydroxymethyl-terminated perfluoromethylenes, polyalkylene ether glycols, ether glycols. of polyalkylenenalene, and polyalkylene ether triols. The polyol can also be selected from the group comprising polyester of adipic acid-ethylene glycol, poly (butylene glycol), poly (propylene glycol), and hydroxy-terminated polybutadiene - see, for example, British Patent Number 1,482,213, the content of which is incorporated herein by reference. Preferably, this polyol has a molecular weight in the range from about 200 to about 10,000, more preferably from about 1,500 to about 4,300, and most preferably from about 3,000 to about 4,100. Ideally, this polyol would predominantly contain secondary hydroxyl groups. As described above, it is possible to use a prepolymer technique to produce a polyurethane foam within the scope of the present invention. In one embodiment, it is contemplated that the prepolymer is prepared by the reaction of an excess of isocyanate with a hydrophilic polyol (as described above). Then the prepolymer could be reacted with a non-hydrophilic polyol (as described above) to produce a polyurethane foam, or an amine to produce a polyurea modified with polyurea. In another embodiment, it is contemplated that the prepolymer is prepared by reacting an excess of isocyanate with a non-hydrophilic polyol (as described above). Then the prepolymer could be reacted with a hydrophilic polyol (as described above) to produce a polyurethane foam. In yet another embodiment, if a single polyol provides a desirable total ethylene oxide content (as described above), the prepolymer can be prepared and reacted to produce polyurethane using the same polyol. If the process is used to produce a polyurethane-modified polyurea foam, the non-hydrophilic active hydrogen-containing compound comprises, at least in part, compounds wherein the hydrogen is bonded to the nitrogen. Preferably, these compounds are selected from the group comprising polyamines, polyamides, polyimines, and polyolamines, more preferably polyamines. Non-limiting examples of these compounds include polyethers terminated in primary and secondary amine. Preferably these polyethers have a molecular weight of greater than about 1,500, a functionality of 2 to 6, and an amine equivalent weight of from about 200 to about 6,000. These amine terminated polyethers are typically made from an appropriate initiator to which a lower alkylene oxide is added (eg, ethylene, propylene, butylene, and mixtures thereof), the resulting hydroxyl-terminated polyol subsequently being aired. If two or more alkylene oxides are used, they may be present either as random mixtures or as blocks of one or the other polyether. For greater ease of aminating, it is especially preferred that the hydroxyl groups of the polyol are essentially all secondary hydroxyl groups. Typically, the amination step replaces most, but not all, hydroxyl groups of the polyol. If the process is used to produce a polyurethane foam or a urea-modified polyurethane, it is possible, and it is really preferred, using a single polyol or a mixture of polyols having a total ethylene oxide content in the range from about 15 to about 80, preferably from about 20 to about 70, more preferably from about 35 to about 70, and most preferably from about 50 to about 65 weight percent, the remainder comprised of other polyoxyalkylene groups, such as propylene oxide, butylene oxide, or mixtures thereof. Although a preferred and practical method for achieving this total ethylene oxide content is by mixing a hydrophilic polyol and a non-hydrophilic polyol as described hereinabove, it will be appreciated that it is possible and even preferred to use a single polyol which possesses substantially the same ethylene oxide content as a mixture of a hydrophilic polyol and a non-hydrophilic polyol. This polyol is disclosed in pending U.S. Patent Application Serial Number 08 / 576,695, filed December 21, 1995, the contents of which are incorporated herein by reference. The superabsorbent material used in the uniform mixture is capable of absorbing at least about 20 times its weight of an aqueous fluid maintained at a temperature in the range of about 20 ° C to about 25 ° C. Preferably, the superabsorbent material is a synthetic polymer such as a cellulosic polymer or a polymer of at least one of an acrylic monomer and a vinyl monomer, although it is possible to use other materials such as copolymers of maleic acid and isobutylene (typically in the form of fiber), and polyethers. A non-limiting example of a suitable cellulosic polymer is a carboxymethyl cellulose and alkali metal salts thereof. A non-limiting example of a suitable polymer of at least one of an acrylic monomer and a vinyl monomer can be selected from the group consisting of polyvinylpyrrolidone, sulfonated polystyrene, polysulfethyl acrylate, poly (2-hydroxyethyl acrylate), polyacrylamide, poly (acrylic acid) and alkali metal salts thereof, poly (alkali metal salt of acrylic acid), polyacrylic acid modified with starch and alkali metal salts thereof, poly (alkali metal salt of acrylic acid modified with starch), hydrolyzed polyacrylonitrile and alkali metal salts thereof, poly (hydrolyzed polyacrylonitrile alkali metal salt), poly (vinyl alcohol acrylic acid alkali metal salt), salts thereof and mixtures thereof. More preferably, the superabsorbent material is a poly (alkali metal salt of acrylic acid), such as poly (sodium acrylate). Although the amount of superabsorbent material used in the initial step of the present process is not particularly restricted, it is preferred that the superabsorbent material be present in an amount of up to about 150 parts by weight per 100 parts by weight of the active hydrogen-containing compound used for produce the foamed isocyanate-based polymer. More preferably, the superabsorbent material is present in an amount in the range from about 20 to about 80 parts, still more preferably from about 35 to about 75 parts, and most preferably from about 55 to about 65 parts by weight per 100 parts by weight of the active hydrogen-containing compound used to produce the foamed isocyanate-based polymer. Of course, as improvements are made to the superabsorbent materials, it is contemplated that the level of filler required in the present foamed isocyanate-based polymer can be reduced while retaining a given absorption and retention. The way in which the uniform mixture of isocyanate, a hydrogen-containing compound, is prepared, and superabsorbent material, is not restricted in a particular way. Accordingly, it is possible to premix the components in a separate tank, which is then connected to a suitable mixing device to be mixed with the aqueous blowing agent and the catalyst. Alternatively, it is possible to premix the superabsorbent material with the active hydrogen-containing compound. This premixing could then be fed to a suitable mixing head, which would also receive streams independent of the isocyanate, the aqueous blowing agent, and the catalyst (streams of aqueous blowing agent and catalyst could be combined before the mixing head, if it is desired). In this embodiment, care should be taken to design the mixing head to ensure that the premix and isocyanate streams are properly mixed at the time the streams of aqueous blowing agent and catalyst are added. As is known in the art, aqueous blowing agents such as water can be used as a reactive blowing agent in the production of foamed isocyanate-based polymers. Specifically, the water reacts with the isocyanate to form carbon dioxide, which acts as the effective blowing agent in the final foamed polymer product. Optionally, organic blowing agents can be used in conjunction with the aqueous blowing agent, although the use of these blowing agents is generally limited by environmental considerations. It is known in the art that the amount of water used as a blowing agent in the preparation of a foamed isocyanate-based polymer is conventionally in the range of about 0.5 to as much as about 20 or more parts by weight, preferably about 1.0. to about 5.0 parts by weight, based on 100 parts by weight of the total content of the active hydrogen-containing compound in the reaction mixture. Since the amount of water used in the production of a foamed isocyanate-based polymer is limited by the expected fixed properties in the foamed polymer, it may be necessary, under certain circumstances, to use substantially inert liquid extenders when high material loads of the foamed material are contemplated. filling. Non-limiting examples of suitable liquid extenders include halogenated hydrocarbons and high molecular weight hydrocarbons. The catalyst added to the uniform mixture of isocyanate, compound containing active hydrogen, and superabsorbent material, is a compound capable of catalyzing the polymerization reaction. These catalysts are known, and their selection and concentration is within the reach of a person skilled in the art. See, for example, Patents of the United States of North America Nos. 4,296,213 and 4,518,778, the contents of which are incorporated herein by reference. Non-limiting examples of suitable catalysts include tertiary amines and / or organometallic compounds. Additionally, as is known in the art, when the objective is to produce an isocyanurate, a Lewis acid should be used as the catalyst, either alone or in conjunction with other catalysts. Of course, it will be understood by experts in this field, that a combination of two or more catalysts can be suitably used. Although the above description refers to one of the process embodiments of the present invention (ie, addition of catalyst / water to a uniform mixture of isocyanate, active hydrogen-containing compound, and superabsorbent material), it is equally applicable to the second process modality of the present invention (ie, addition of isocyanate to a uniform catalyst / water mixture, active hydrogen-containing compound, and superabsorbent material), with respect to the selection and concentration of the different ingredients. In other words, the above description with respect to the selection and concentration of the different ingredients, can be easily applied to the "one shot" process, wherein the resin stream comprises catalyst, water, active hydrogen-containing compound, and superabsorbent material, a which is added the isocyanate. As will be clearly understood by an expert in this field, it is contemplated that conventional additives in the isocyanate-based polymer technique may be used in the process. Non-limiting examples of these additives include: surfactants (e.g., organosilicon compounds available under the trade name L-540 from OSI), cell openers (e.g., silicone oils), extenders (e.g., commercially available halogenated paraffins) as Cereblor S45), crosslinkers (eg, compositions containing low molecular weight reactive hydrogen), pigments / dyes, fire retardants (eg, halogenated organophosphorus acid compounds), inhibitors (eg, weak acids), nucleation (for example, diazo compounds), antioxidants, plasticizers / stabilizers (for example, sulfonated aromatic compounds), and biocides. The amount of these conventionally used additives would be within the reach of a person skilled in the art. A particularly preferred class of additives that can be used herein is that of fillers. The particular advantage is that different fillers, such as pulp and after-consumer items milled (e.g., rims, reaction injection molded parts, reinforced reaction injection molded parts, out-of-specification personal hygiene devices, etc.), they can be effectively recycled in the present foamed isocyanate-based polymer with little or no compromise in the absorption and retention of the aqueous fluid. Once the aqueous blowing agent and the catalyst have been added to the uniform mixture of isocyanate, active hydrogen-containing compound, and superabsorbent material, a reaction mixture is formed. This reaction mixture is then expanded to produce the present foamed isocyanate-based polymer. As will be seen by those skilled in the art, the process of the present invention is useful in the production of ingot foam, molded articles, under carpets, and the like. Therefore, as can be seen by a person skilled in the art, the manner in which the expansion of the reaction mixture is effected will be dictated by the type of foam that is being produced. The product of the present process is a foamed isocyanate-based polymer having a cellular structure and containing a superabsorbent material, the polymer being capable of: (i) absorbing at least about 20 times its weight of an aqueous fluid maintained at a temperature of about 20 ° C to about 25 ° C, and (ii) retaining at least about 20 times its weight of the absorbed aqueous fluid that is bonded to the superabsorbent material. Preferably, the polymer is capable of: (i) absorbing from about 20 to about 100, more preferably from about 20 to about 80, and most preferably from about 35 to about 65 times its weight of an aqueous fluid maintained at a temperature of about 20 ° C to about 25 ° C, and (ii) retaining from about 20 to about 90, more preferably from about 20 to about 70, and most preferably from about 30 to about 55 times its weight of absorbed aqueous fluid which is bonded with the superabsorbent material. The ability of the foamed isocyanate-based polymer to absorb aqueous liquid (eg, water) can be evaluated by the following protocol: (i) weighing the foamed isocyanate-based polymer test sample (W), (ii) submerging the test sample in an aqueous fluid maintained at a temperature of about 20 ° C to about 25 ° C for a period of at least 30 minutes(iii) remove the test sample from the aqueous fluid and keep it on a trickle screen or similar device for 3 minutes, (iv) weigh the test sample (Wf), and (iv) calculate (V¡fV¡L) / VIL, and report as the amount of aqueous fluid absorbed as a multiple of the weight of the original test sample of foamed isocyanate-based polymer (W) (another way in which the results are reported, is as units of liquid mass water absorbed per unit mass of foam). The ability of the foamed isocyanate-based polymer to retain the aqueous liquid can be assessed by conducting the absorption protocol and subsequent subsequent steps: (v) compressing the test sample containing the absorbed aqueous fluid until it can no longer be expelled forcing more aqueous fluid (eg, at a compression force of at least about 0.07 kg / cm2, more preferably at least about 0.0791 kg / cm2) of the test sample, (vi) weighing the test sample (Wr), and (iv) calculate (Wr-Wi) / Wi and report as the amount of aqueous fluid retained as a multiple of the weight of the original test sample of foamed isocyanate-based polymer (?) (another way in which the results, is like units of mass of aqueous liquid retained per unit mass of foam). Accordingly, the two protocols distinguish between the aqueous fluid that physically and chemically bonds to the foam (i.e., is absorbed), and the aqueous fluid that only chemically bonds to the foam (i.e., is retained). Accordingly, the retention properties of the present foamed isocyanate-based polymer mimic the retention properties that are desirable in a main practical application of the present invention. Specifically, if the present foam product is used in the core of a diaper, the retention properties of the aqueous fluid referred to above are convenient, since they predict a diaper core that will absorb, inter alia, urine, while mitigating against the Significant amounts of absorbed urine that are squeezed from the core against the child's skin or leaking from the diaper. The type of superabsorbent material and the amount thereof present in the foamed isocyanate-based polymer is as described hereinabove with respect to the present process. Accordingly, as will be appreciated by those skilled in the art, the foam product of the present invention, which has suitable properties of absorption and retention of aqueous fluids (e.g., water), is the direct product of polymerization and expansion. In other words, the convenient properties of the foam product of the present invention do not depend on any specific complicated and costly crosslinking step (or other post-treatment), as taught by Kelly et al., As described above. Those skilled in the art will recognize that the foam product of the present invention is not a thermally crosslinked product - that is, the foam product of the present invention is non-crosslinked. Rather, the foam product of the present invention is a cellular material having an open cell structure (i.e., cells with cracked or broken membranes between the cell struts as described above), as opposed to a skeletal or structure as described by Kelly et al. The present foamed isocyanate-based polymer preferably has a density of about 1.0 pcf to about 15.0 pcf, more preferably from about 1.0 pcf to about 12.0 pcf, still more preferably from about 1.0 pcf to about 8.0 pcf, most preferably of about 1.5 pcf at approximately 5.0 pcf. The embodiments of the present invention will now be described with reference to the following examples, which should not be construed to limit the scope of the invention. The term "pbw" used in the examples refers to parts by weight. In the examples, the following compounds were used: 1. DABC0-T16, a polymerization catalyst commercially available from Air Products and Chemicals, Inc.; 1. Z65, a tertiary amine catalyst commercially available under the tradename JEFFCAT from Huntsman Corporation; 2. TECOSTAB B8202, a surfactant commercially available from Goldschmidt Chemical Corporation; 3. VORANOL CP1421, a hydrophilic polyether polyol having a molecular weight of about ,000, and an ethylene oxide content of about 80 weight percent, available from The Dow Chemical Company; 4. Pluracol 593, a hydrophilic polyether polyol having a molecular weight of about 5,000, and an ethylene oxide content of about 75 weight percent, available from BASF Corporation; 5. Arcol 2580, a hydrophilic polyether polyol having a molecular weight of about 5,000, and an ethylene oxide content of about 75 weight percent, available from Arco Corporation; 6. VORANOL 3010, a non-hydrophilic polyether polyol having a molecular weight of about 3,000, and an ethylene oxide content of less than about 20 weight percent, commercially available from The Dow Chemical Company; 7. Arcol HS100, a non-hydrophilic polyether polyol which is a mixture of 3010 and polymer solids, commercially available from Arco Chemical Company; 8. TDI 80, a mixture of 80 weight percent 2,4-toluene diisocyanate, and 20 weight percent 2,6-toluene diisocyanate, commercially available from Bayer Corporation under the trade name Mondur TD- 80 Grade A; 9. IM4000 and IM4500, sodium polyacrylate grafted with starch available from Hoechst Celanese Corporation; . ASAP 1100, a slightly crosslinked sodium polyacrylate available from Chemdal Corporation; 11. SXM-75, a poly (sodium acrylate) compound available from Stockhausen Inc .; and 12. RRIM, a reinforced reaction injection molded elastomer milled to have a mesh size of -18 to +74 (which corresponds to a particle size of about 210 microns to about 1000 microns).

EXAMPLES 1-10 In these examples, a series of hydrophilic polyurethane foams containing different amounts of superabsorbent material were prepared. The general formulation used is provided in Table 1. The amount of superabsorbent material used in each example is given in Table 2.

TABLE The foams were prepared by mixing the two polyols with the superabsorbent material, to which the isocyanate was added to form a uniform mixture. The remaining ingredients, including the catalyst and the water blowing agent, were mixed separately, and then added to the uniform mixture of polyols, superabsorbent material, and isocyanate, with a suitable mixture to provide a uniform reaction mixture. The reaction mixture was poured into an open container, and allowed to expand to result in a polyurethane foam. Each foam was cut to provide triplicate samples having the following dimensions: 7.62 cm x 12.7 cm x 1.27 cm. The water absorption and retention properties of each of the triplicate samples were evaluated using the absorption and retention protocols described above. The aqueous liquid was water and the immersion time was 60 minutes. The results, reported for each example as the absorption and average retention, respectively, for the triplicate samples, are given in Table 2.

A B L A As will be seen by experts in this field, Example 1 does not contain superabsorbent material, and is provided for comparison purposes only. The results clearly demonstrate that the foams produced in Examples 2-10 exhibit significantly improved absorption and retention properties, compared to a hydrophilic foam that does not contain a superabsorbent material (Example 1).

Examples 11-14 In these examples, the methodology of Examples 1-10 was repeated, except that a mixture of non-hydrophilic polyols was used instead of the mixture of hydrophilic polyol / non-hydrophilic polyol used in Examples 1-10. In accordance with the foregoing, it will be understood by experts in this field that Examples 11-14 are for comparative purposes only. The general formulation used in Examples 11-14 is provided in Table 3. The amount of superabsorbent material used in each example is given in Table 4.

TABLE The foams produced in these Examples 11-14 were tested for water absorption and retention properties, employing the protocol described in Examples 1-10. The results are given in Table 4, and demonstrate the importance of using a hydrophilic polyol in the formulation. Specifically, the absorption and retention properties of the foams produced in Examples 2-10 are almost double those of the foams produced in Examples 11-14. In addition, comparison of the absorption and retention properties of (i) the foam produced in Example 1 and any of the foams produced in Examples 11-14, with (ii) the foams produced in Examples 2-10 (ie, exemplary foams according to the present invention), demonstrates that improvements in water absorption and retention are synergistic.

TABLE EXAMPLES 15-38 In these examples, a series of hydrophilic polyurethane foams containing different amounts of superabsorbent materials were prepared. The general formulation used is given in Table 5. The amount of superabsorbent material used in each example is given in Table 6.

For each example, the foam was prepared by mixing the two polyols with the catalyst and the water blowing agent, to which the superabsorbent material was added with suitable agitation to provide a uniform mixture. Subsequently, the isocyanate was added to the uniform mixture. The reaction mixture was poured into an open container, and allowed to expand to result in a polyurethane foam impeller having the following dimensions: 22.86 cm x 24.13 cm x 10.16 cm. For a given composition, the procedure was repeated twice, such that a total of three foam impellers were produced for each example (except Examples 33-38, where only one impeller was produced). Each foam impeller was cut to provide 10 samples having the following dimensions: 7.62 cm x 12.7 cm x 1.27 cm. Accordingly, for a given composition, 30 samples were made for the test (ie, 3 runners x 10 samples / runner = 30 samples). The water absorption and retention properties of each of the 30 samples were evaluated using the absorption and retention protocols described above. The aqueous liquid was water and the immersion time was 60 minutes. The results, reported for each example as the average absorption and retention, respectively, for the 30 samples of the example, are given in Table 6 (that is, the average absorption and average retention for each batch of 10 samples of a runner. of given foam).

T A B L 5 As will be seen by experts in this field, Example 15 does not contain superabsorbent material, and is provided for comparison purposes only. The results, among other things, clearly demonstrate that: (i) the foams produced in Examples 16-38 exhibit significantly improved absorption and retention properties, compared to a hydrophilic foam that does not contain a superabsorbent material (Example 15); and (ii) that the foams produced in Examples 32-38 contained large amounts of superabsorbent material, and exhibited very high absorption and retention properties. TABLE EXAMPLES 39-57 The methodology employed in Examples 15-38 was repeated, including the formulation provided in Table 5 above, in these examples, with the exception that the superabsorbent material used in these examples was ASAP 1100. The amount of ASAP 1100 used in each of these Examples 39-57 is reported in Table 7, together with the results of the absorption and retention test using the protocol described hereinabove, in Examples 15-38. As will be seen by those skilled in the art, Example 39 does not contain superabsorbent material, and is provided for comparison purposes only. The results, among other things, clearly demonstrate that: (i) the foams produced in Examples 40-57 exhibit significantly improved absorption and retention properties, compared to a hydrophilic foam that does not contain a superabsorbent material (Example 39).

EXAMPLES 58-63 In these examples, a series of hydrophilic polyurethane foams containing different amounts of hydrophilic polyol / non-hydrophilic polyol were prepared. The hydrophilic polyol used was CP1421, and the non-hydrophilic polyol used was VORANOL 3010 (referred to as 3010).

The general formulation used is given in Table 8. The relative amounts of hydrophilic polyol and non-hydrophilic polyol used in each example are given in Table 9. For each example, the foam was prepared by mixing the two polyols (except in Example 58, where a single polyol was used), with the catalyst and the water blowing agent, to which the superabsorbent material was added with adequate agitation to provide a uniform mixture. Subsequently, the isocyanate was added to the uniform mixture. The reaction mixture was poured into an open container, and allowed to expand to result in a polyurethane foam impeller having the following dimensions: 22.86 cm x 24.13 cm x 10.16 cm. For a given composition, the procedure was repeated twice, so that a total of three foam impellers were produced for each example (except in Examples 59 and 63, where two impellers were produced).

T A B L A 7 Each foam impeller was cut to provide ten samples having the following dimensions: 7.62 cm x 12.7 cm x 1.27 cm. Accordingly, for a given composition, thirty samples were made for the test (ie, 3 runners x 10 samples / runner = 30 samples), except in Examples 59 and 63, where twenty samples were made for the test (ie say, 2 runners x 10 samples / runner = 20 samples). The water absorption and retention properties of each of the thirty samples were evaluated using the absorption and retention protocols described above. The aqueous liquid was water, and the immersion time was 60 minutes. The results, reported for each example as the average absorption and retention, respectively, for all samples of the example, are given in Table 9 (ie, the mean absorption and average retention for each batch of ten samples of a runner). of given foam).

T A B L A 8 T A B L A 9 As will be seen by those skilled in the art, Example 58 does not contain hydrophilic polyol, and is provided for comparison purposes only. The results, among other things, clearly demonstrate that the foams produced in Examples 59-63 exhibit significantly improved absorption and retention properties compared to a foam that does not contain a hydrophilic polyol (Example 58).

EXAMPLES 64-69 The methodology employed in Examples 58-63 was repeated for these examples, using the formulation of Table 8, with the exception that the hydrophilic polio used was Pluracol 593. The relative amounts of hydrophilic polyol (593) and non-hydrophilic polyol (3010) are reported in Table 10, along with the results of the absorption and retention test (note: two foam impellers were produced in Example 64, and three foam impellers were produced in each of the Examples 65-69).

T A B L A 10 As will be seen by those skilled in the art, Example 64 does not contain hydrophilic polyol, and is provided for comparison purposes only. The results, among other things, clearly demonstrate that the foams produced in Examples 65-69 exhibit significantly improved absorption and retention properties, compared to a foam that does not contain a hydrophilic polyol (Example 64).

EXAMPLES 70-76 The methodology used in Examples 58-63 was repeated for these examples, using the formulation of Table 8, with the exception that the hydrophilic polio used was Arcol 2580. The relative amounts of hydrophilic polyol (Arcol 2580) and non-hydrophilic polyol (3010) are reported in Table 11, along with the results of the absorption and retention test (note: two foam impellers were produced in Example 71, and three foam impellers were produced in each of Examples 70 and 72-76).

T A B L A 11 As will be seen by those skilled in the art, Example 70 does not contain hydrophilic polyol, and is provided for comparison purposes only. The results, among other things, clearly demonstrate that the foams produced in Examples 71-76 exhibit significantly improved absorption and retention properties, compared to a foam that does not contain a hydrophilic polyol (Example 70).

EXAMPLES 77-90 A number of commercially available personal hygiene products (ie, disposable diapers, feminine tampons / pads, incontinence pads, and incontinence devices) were tested to determine their ability to absorb and retain water. The following general test procedure was used. The dry weight of the product was determined, after which it was subjected to immersion in water and to the absorption and retention test as described hereinabove for the different polyurethane foam products. The results of the absorption and retention test are given in Table 12.

TAB LA 12 These results demonstrate that several of the present polyurethane foams exemplified above, exhibit water absorption and retention properties that are similar to, or in excess of, different commercially available personal hygiene devices. It is contemplated that the present polyurethane foam can be used to replace the absorbent core of these devices for personal hygiene, to provide lighter devices that have better absorbency and water retention properties.

EXAMPLE 91 In this example, a polyurethane foam was prepared in accordance with the present invention, using a filler material (RRIM). The formulation used is given in Table 13.

T A B L A 13 The foam was prepared by mixing the two polyols with the catalyst and the water blowing agent, to which was added the RRIM and the superabsorbent material with appropriate agitation to provide a uniform mixture. Subsequently, the isocyanate was added to the uniform mixture. The reaction mixture was poured into an open container, and allowed to expand to result in a polyurethane foam impeller having the following dimensions: 22.86 cm x 24.13 cm x 10.16 cm. For a given composition, the procedure was performed three times, in such a way that a total of three foam impellers were produced for each example. Each foam impeller was cut to provide ten samples having the following dimensions: 7.62 cm x 12.7 cm x 1.27 cm. Accordingly, thirty samples were made for the test. The water absorption and retention properties of each of the thirty samples were evaluated using the absorption and retention protocols described above. The aqueous liquid was water, and the immersion time was 60 minutes. The average absorption of the ten batch samples of each runner was determined in: 42.9, 44.3, and 33.6, respectively (average: 40.3). The average retention of the ten batch samples of each runner was determined in: 32.3, 33.1, and 24.7, respectively (average: 30.0). The results, among other things, clearly demonstrate that it is possible to produce a filled foam within the scope of the invention, without a significant compromise of the ability of the foam to maintain its water absorption and retention properties. EXAMPLE 92 A number of commercially available personal hygiene products were tested by the absorption of water in direct comparison with two polyurethane foams in accordance with the present invention. The polyurethane foams were prepared according to the formulation provided in Table 14, using the procedure described above in Examples 15-38. In this example, the following products were tested: Designation Product A Foam produced using the formulation of Table 14, including 25 parts by weight of IM4500.

B Foam produced using the formulation of Table 14, including 50 parts by weight of IM4500.

H Huggies111 * Ultra Trim For Girls (for girls) (diaper product).

Kotex1 ^ Occasions (product for feminine hygiene).

T A B L A 14 These products were tested by water absorption during the following periods: 1 minute, 5 minutes, 10 minutes, 20 minutes, and 30 minutes. The test protocol for commercially available personal hygiene products was that described above in Examples 77-90, modified to reduce the period of immersion in water. The test protocol for the polyurethane foam was that described above in Examples 15-38, modified to reduce the period of immersion in water. The results are illustrated graphically in Figure 1. The designations of A, B, H, and K shown in Figure 1 correspond to those referred to above.

EXAMPLE 93 Example 92 was repeated, with the exception that the fluid used in the test protocol was 0.9 percent serum. The results are illustrated in Figure 2. These results are striking in that the absorption properties of the polyurethane foam B in relation to Huggies * 1 Ultratrim For Girls (For Girls) were significantly different from those reported in Example 92. Specifically , a surprising and unexpected significant increase in absorption properties for polyurethane foam B can be seen. This suggests that, when moving from water uptake to serum absorption, there is a relative increase in fluid uptake by the polyurethane foam B, comparing with Huggies * 1 Ultratrim For Girls (For Girls). This unexpected result makes a foam such as polyurethane foam B, a suitable candidate for use in a device intended to absorb urine and other salt-based fluids (eg, diapers).

EXAMPLE 94 The commercially available personal hygiene products and the polyurethane foams referred to in Examples 93 and 94, were tested through the layers to determine the absorption rate. Additionally, a sample of Huggies1® Ultratrim For Girls diapers was modified to remove the top sheet - this sample is designated as HwoTS in this example. The designations of A, B, and H, used in this example, are the same as those referred to above in Example 93. The polyurethane foams A and B were placed in a conventional diaper construction. Accordingly, all samples tested in this example were in the form of diaper constructions. The following test protocol was employed. The test diaper was extended flat and an impact device was aligned towards the objective area of the diaper. The impact device consisted of a plexiglass cylinder with an internal diameter of 5.08 cm installed on a base support. A 100 milliliter sample of 0.9% serum solution was poured into the impact device. The time required for the serum to disperse from the impact device (i.e., become absorbed by the diaper surface) was recorded - this is referred to as AGGRESSION 1.

For each test diaper, two additional aggressions, AGGRESSION 2 and AGGRESSION 3, were conducted in a similar manner. As is known to the experts in this field, the shorter the period to complete the absorption of an assault, the better the absorption rate of the test diaper will be. The results of these tests through the layers are illustrated graphically in Figure 3. These results are surprising and unexpected. Specifically, with reference to polyurethane foams A and B, the period for ending multiple aggressions decreased or remained substantially the same, and was recorded at or below approximately 6 seconds. In contrast, the period for finishing multiple aggressions on the HwoTS samples, increased with successive aggressions, and was recorded in approximately 11 seconds to approximately 28 seconds for the HwoTS sample, and from approximately 13 seconds to approximately 27 seconds for the H sample. These results show that polyurethane foams A and B are superior to Huggies ^ Ultratrim For Girls in the speed of absorption through the layers.

Claims (33)

1. A foamed isocyanate-based polymer having a cellular structure, and containing a superabsorbent material, the polymer being capable of: (i) absorbing at least about 20 times its weight of an aqueous fluid maintained at a temperature of about 20 ° C at about 25 ° C, and (ii) retaining at least about 20 times its weight of the absorbed aqueous fluid that binds to the superabsorbent material.

2. A foamed isocyanate-based polymer defined in claim 1, wherein the polymer is capable of: (i) absorbing from about 20 to about 100 times its weight of an aqueous fluid maintained at a temperature of about 20 ° C to about 25 ° C, and (ii) retaining from about 20 to about 90 times its weight of the absorbed aqueous fluid that binds to the superabsorbent material.

3. A foamed isocyanate-based polymer defined in claim 1, wherein the polymer is capable of: (i) absorbing from about 20 to about 80 times its weight of an aqueous fluid maintained at a temperature of about 20 ° C to about 25 ° C, and (ii) retaining from about 20 to about 70 times its weight of the absorbed aqueous fluid that binds to the superabsorbent material.

4. A foamed isocyanate-based polymer defined in claim 1, wherein the polymer is capable of: (i) absorbing from about 35 to about 65 times its weight of an aqueous fluid maintained at a temperature of about 20 ° C to about 25 ° C, and (ii) retain from about 30 to about 55 times its weight of the absorbed aqueous fluid that binds to the superabsorbent material.

5. A foamed isocyanate-based polymer defined in claim 1, wherein the superabsorbent material is a synthetic polymer.

6. A foamed isocyanate-based polymer defined in claim 1, wherein the superabsorbent material is a cellulosic polymer.

7. A foamed isocyanate-based polymer defined in claim 6, wherein the cellulosic polymer is a carboxy-ethyl cellulose.

8. A foamed isocyanate-based polymer defined in claim 1, wherein the superabsorbent material is a polymer of at least one of an acrylic monomer and vinyl monomer.

9. A foamed isocyanate-based polymer defined in claim 1, wherein the superabsorbent material is selected from the group consisting of: polyvinylpyrrolidone, sulfonated polystyrene, polysulfethyl acrylate, poly (2-hydroxyethyl acrylate), polyacrylamide, acid polyacrylic, poly (alkali metal salt of acrylic acid), polyacrylic acid modified with starch, poly (alkali metal salt of acrylic acid modified with starch), hydrolyzed polyacrylonitrile, poly (hydrolyzed polyacrylonitrile alkali metal salt), and mixtures of the same. A foamed isocyanate-based polymer defined in claim 1, wherein the superabsorbent material is present in an amount of up to about 150 parts by weight per 100 parts by weight of the active hydrogen-containing compound used to produce the isocyanate-based polymer. foamed 11. A foamed isocyanate-based polymer defined in claim 1, wherein the superabsorbent material is present in the range of about 20 to about 110 parts by weight per 100 parts by weight of the active hydrogen-containing compound used to produce the polymer based in foamed isocyanate. A foamed isocyanate-based polymer defined in claim 1, wherein the superabsorbent material is present in the range of about 35 to about 75 parts by weight per 100 parts by weight of the active hydrogen-containing compound used to produce the polymer based in foamed isocyanate. 13. A foamed isocyanate-based polymer defined in claim 1, wherein the superabsorbent material is present in the range of about 55 to about 65 parts by weight per 100 parts by weight of the active hydrogen-containing compound used to produce the foamed isocyanate-based polymer. A foamed polyurethane polymer comprising poly (alkali metal salt of acrylic acid) in an amount in the range of about 55 to about 65 parts by weight per 100 parts by weight of the polyol used to produce the foamed polyurethane polymer, the polymer being capable of: (i) absorbing from about 35 to about 65 times its weight of an aqueous fluid maintained at a temperature from about 20 ° C to about 25 ° C, and (ii) retaining from about 30 to about 55 times its weight of the absorbed aqueous fluid that bonds with the poly (alkali metal salt of acrylic acid). 15. A process for producing a foamed isocyanate-based polymer, which comprises the steps of: providing a substantially uniform mixture comprising an isocyanate, an active hydrogen-containing compound, and a superabsorbent material, the superabsorbent material being capable of absorbing when less about 20 times its weight of an aqueous fluid maintained at a temperature in the range of about 20 ° C to about 25 ° C; adding an aqueous blowing agent and a catalyst to the substantially uniform mixture to form a reaction mixture; and expanding the reaction mixture to produce the foamed isocyanate-based polymer; wherein the active hydrogen-containing compound comprises from about 10 percent to 100 percent by weight of a compound containing hydrophilic active hydrogen, and from 0 to about 90 percent by weight of a compound containing non-hydrophilic active hydrogen . The process defined in claim 15, wherein the active hydrogen-containing compound comprises from about 20 percent to about 90 percent by weight of a compound containing hydrophilic active hydrogen, and about 10 percent by weight. about 80 weight percent of a compound containing non-hydrophilic active hydrogen. The process defined in claim 15, wherein the active hydrogen-containing compound comprises from about 40 percent to about 90 percent by weight of a compound containing hydrophilic active hydrogen, and about 10 percent by weight about 60 weight percent of a compound containing non-hydrophilic active hydrogen. The process defined in claim 15, wherein the active hydrogen-containing compound comprises from about 70 percent to about 80 percent by weight of a compound containing hydrophilic active hydrogen, and about 20 percent by weight about 30 weight percent of a compound containing non-hydrophilic active hydrogen. 19. The process defined in claim 15, wherein the hydrophilic active hydrogen-containing compound is a hydrophilic polyol. The process defined in claim 19, wherein the hydrophilic polyol is selected from the group consisting of diols, triols, and tetroles containing polyoxyalkylene groups, the polyoxyalkylene groups comprising at least 25 weight percent oxide ethylene. The process defined in claim 15, wherein the non-hydrophilic active hydrogen-containing compound is selected from the group consisting of polyols, polyamines, polyamides, polyimines, non-hydrophilic polyolamines, and mixtures thereof. 22. The process defined in claim 15, wherein the non-hydrophilic polyol is a hydroxyl-terminated compound selected from the group consisting of polyether, polyesters, polycarbonate, polydiene, polycaprolactone, and mixtures thereof. 23. The process defined in claim 15, wherein the non-hydrophilic polyol is selected from the group consisting of polyester of adipic acid-ethylene glycol, poly (butylene glycol), poly (propylene glycol), polybutadiene terminated in hydroxyl, and mixtures thereof. 24. The process defined in claim 22, wherein the non-hydrophilic polyol is a polyether polyol. 25. The process defined in claim 24, wherein the polyether polyol has a molecular weight in the range of about 200 to about 10,000. 26. The process defined in claim 15, wherein the hydrogen-containing compound is a polyamine or a polyalkanolamine. 27. The process defined in claim 26, wherein the polyamine is selected from the group comprising polyethers terminated in primary and secondary amine. 28. The process defined in claim 15, wherein the isocyanate is represented by the general formula: QINK ^ where i is an integer of 2 or more, and Q is an organic radical that has the valence of i. 29. The process defined in claim 15, wherein the isocyanate is selected from the group comprising 1,6-hexamethylene diisocyanate, 1,4-butylene diisocyanate, furfurylidene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,4 '-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyl propane diisocyanate, 4,4'-diphenyl-3, 3 * -dimethylmethane diisocyanate , 1,5-naphthalene diisocyanate, 1-methyl-2,4-diisocyanato-5-chlorobenzene, 2,4-diisocyanato-s-triazine, l-methyl-2,4-diisocyanatocyclohexane, p-phenylene diisocyanate, diisocyanate of m-phenylene, 1,4-naphthalene diisocyanate, dianisidine diisocyanate, bitolylene diisocyanate, 1,4-xylylene diisocyanate, 1,3-xylylene diisocyanate, bis (4-isocyanatophenyl) methane, bis (3-methyl) -4-is o ianat of in 1) methano, polymethylene polyphenyl polyisocyanates, and mixtures thereof. 30. The process defined in claim 15, wherein the isocyanate is selected from the group comprising 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, and mixtures thereof. The process defined in claim 15, wherein the isocyanate is selected from the group consisting essentially of (i) 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, and mixtures thereof; and (ii) mixtures of (i) with an isocyanate selected from the group comprising 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, and mixtures thereof. 32. A personal hygiene device having an absorbent layer of body fluids consisting essentially of the foamed isocyanate-based polymer defined in claim 1. 33. A personal hygiene device having a body fluid absorbing layer consisting of essentially in the foamed polyurethane polymer defined in claim 14. SUMMARY A foamed isocyanate-based polymer having a cellular structure and containing a superabsorbent material, the polymer being capable of: (i) absorbing at least about 20 times its weight of an aqueous fluid maintained at a temperature of about 20 ° C to about 25 ° C, and (ii) retaining at least about 20 times its weight of the absorbed aqueous fluid that binds to the superabsorbent material. A process for producing a foamed isocyanate-based polymer, which comprises the steps of: providing a substantially uniform mixture comprising an isocyanate, an active hydrogen-containing compound, and a superabsorbent material, the superabsorbent material being capable of absorbing at least about 20 times its weight of an aqueous fluid maintained at a temperature in the range of about 20 ° C to about 25 ° C; adding an aqueous blowing agent and a catalyst to the substantially uniform mixture to form a reaction mixture; and expanding the reaction mixture to produce the foamed isocyanate-based polymer; wherein the active hydrogen-containing compound comprises from about 10 percent to 100 percent by weight of a compound containing hydrophilic active hydrogen, and from 0 to about 90 percent by weight of a compound containing non-hydrophilic active hydrogen . The foamed isocyanate-based polymer is ideally suited for use in an absorption layer of a personal hygiene device. * * * * *