MXPA96004168A - Member of acquisition and distribution of absorbe nucleus fluids - Google Patents

Abstract

The present invention relates to a disposable absorbent article comprising a liquid permeable upper sheet, a liquid impermeable back sheet and an absorbent core positioned between the upper sheet and the back sheet, characterized the absorbent core because it comprises: (i) a member of acquisition and distribution of fluids having a dry density ranging from 0.03 to 0.20 g / cm3 and consisting essentially of cross-linked cellulosic fibers with C2-C9 polycarboxylic acid. said fibers having lattices which are mainly intrafiber, said fibers having an amount of crosslinking agent of C2-C9 polycarboxylic acid reacted therein in an intrafiber lattice-binding form that provides a water retention value of about 25 to 60, and having distributed thereon from about 0.0005% to 1%, by weight, on a dry fiber basis, of an active surface agent, said fluid acquisition and distribution member having an upper surface adjacent to the upper sheet and a lower surface; and (ii) a fluid storage member having an upper surface in contact with the lower surface of the fluid acquisition and distribution member and comprising discrete particles of absorbent gelling materials.

Description

MEMBER OF ACQUISITION AND DISTRIBUTION OF FLUIDS FOR ABSORBENT NUCLEUS FIELD OF THE INVENTION The present invention relates to disposable absorbent articles using cellulosic fibers crosslinked with C2.C9 polycarboxylic acid. Examples of such absorbent articles are: discarded diapers, training underpants, adult incontinence pads and sanitary napkins.

BACKGROUND OF THE INVENTION Considerations have been given to include elements of acquisition and distribution of fluids in disposable absorbent articles as a goal to minimize the occurrence of prolonged wetting of the skin, denying this as a factor that causes skin irritation, for example of the person's rash. who uses the diaper. Weisman et al., In the patent E.U.A. No. 4,673,402, teaches an absorbent core with a top layer of fluid acquisition / distribution, consisting essentially of hydrophilic fiber materials preferably wood pulp fibers and wood pulp tissue, and a lower fluid storage layer, which consists essentially of a substantially uniform combination of hydrophilic fiber material and particular amounts of discrete particles of fluid-absorbent hydrogel material, substantially insoluble to water, and which is placed towards the front of the absorbent article. In the patent EUA4, 798, 603, Meyer et al., Teach an absorbent article with a transport layer between a topsheet and an absorbent body, wherein the transport layer is less hydrophilic than the absorbent body material and can be a non-woven fibrous web composed of substantially hydrophobic material, such as polypropylene, polyethylene or polyester, which can be treated with selected amounts of transioactive agents to increase its initial wettability. In the patent E.U.A. 4,834,735 Alemany et al. Teach an absorbent member, an acquisition zone and a storage zone laterally surrounding its perimeter, as the acquisition zone having a lower average density and a lower average weight basis per unit area of the storage area . The absorbent member comprises a mixture of hydrophobic fibrous material and discrete particles of absorbent gelling material. Lash et al., In the patent E.U.A. No. 4,935,022, teach a disposable absorbent article with an absorbent core composed of a top acquisition / flux layer of hardened cellulose fibers, and from about 3 to 15% by weight of absorbent gelling material, and a storage layer of lower fluids having an upper surface area smaller in area than the upper surface area of the fluid acquisition / distribution layer and composed of hardened cellulosic fibers and from about 15 to 60% by weight of absorbent gelling material. Reising in the patent teaches a storage layer comprising hydrophilic fiber material and discrete particles of absorbent gelling material, containing an acquisition opening. Young et al., In the patent E.U.A. teach an absorbent core comprising a fluid acquisition / distribution layer, placed in upper number, comprising from about 50 to 100% hardened fibers and a lower fluid storage area, comprising at least 15% by weight of superabsorbent material, by the acquisition layer of good redistribution of fluid having an upper surface of smaller area than the upper surface of said fluid storage area. In the experiments headed for the present invention, the cellulosic fibers crosslinked with C2-C9 polycarboxylic acid, which are the subject of Herron et al. In the patent E.U.A. No. 5,137,537, were used as hardened fibers in the fluid acquisition and distribution member in absorbent cores in disposable diapers. It was found in approximately 10% of babies, on a night use of their diapers, the experience of skin moisture.

BRIEF DESCRIPTION OF THE INVENTION It has been discovered in the present invention that the moisture of the skin is minimized on sustained bases when the acquisition and distribution member comprises cellulose fibers crosslinked with C2-C9 polycarboxylic acid, which contains an active agent, a surface thereof, of Preferably an active surface agent that has been applied to the cellulosic fibers before the crosslinking reactions are carried out. The fluid acquisition and distribution member herein is for use in a disposable absorbent article and has a dry density ranging from 0.03 to 0.20 g / cm.sup.3 and consisting essentially of individualized, crosslinked cellulosic fibers having an amount of a C2-C9 polycarboxylic acid crosslinking agent reacted therein in a crosslinked form of interfiber ester bond to provide a water retention value from about 25 to 60, and having uniformly substantially distributed over it of about 0.005 at 1% by weight, preferably up to about 0.15% by weight, on a dry fiber basis, of the active surface agent, preferably, the active surface agent is a nonionic surfactant, and a non-surface active agent is most preferred. ion formed by the condensation of ethylene oxide with a hydrophobic base formed by the condensation of oxide propylene glycol opylene having an average molecular weight ranging from about 1,000 g / mol to 5,000 g / mol; a hydrophobic poly (oxypropylene) molecular weight, ranging from 900 g / mol to 2.00 g / mol; and from 10 to 80% of poly (oxyethylene), hydrophilic, per unit in the total molecule; most preferably having an average molecular weight of l, 900g / mol; a hydrophobic poly (oxypropylene) molecular weight of 950 g / mol, and 50% by weight hydrophilic poly (oxypropylene) in the total molecule (available under the Trade Name Pluronic L35). The crosslinked, individualized cellulosic fibers with the active surface agent thereon are most preferably prepared by a process comprising heating the uncrosslinked cellulosic fibers with from 1% to 15%, preferably from 3% to 12% by weight, on a citric acid base, applied on a dry fiber base, of C2-C9 polycarboxylic acid crosslinking agent, and from 0.005% to 1%, preferably from 0.01% to 0.2%, by weight, applied on a dry fiber base, active surface agent thereon to remove any contained moisture and cause the polycarboxylic acid crosslinking agent to react with the cellulosic fibers and form crosslinking of ester between cellulose molecules, i.e. to cause curing to form said cellulosic fibers crosslinked with the active surface agent thereon, without washing or without removing the crosslinked or bleached and washed fibers of the crosslinked fibers. The disposable absorbent article, hence, for example, a disposable diaper, training pants, adult incontinence pad or sanitary napkins, comprises a liquid pervious top sheet, a liquid impervious backsheet and an absorbent core placed between the top sheet and the back sheet. The absorbent core comprises (i) the fluid acquisition and distribution member thereon with a top surface positioned adjacent said top sheet and a bottom sheet (ii), a fluid storage member (i.e. fluid), having an upper surface in contact with the lower surface of the fluid acquisition and distribution member and comprising absorbent gelling material. Preferably, the fluid acquisition and distribution member has a top surface with an area that is less than the top surface area of the fluid storage member, very preferably having a top surface with an area that is from about 15% to 95% of the upper surface of the fluid storage member, most preferably a top surface with an area that is from about 20% to 50% the upper surface of the fluid storage member. The term "individualized crosslinked fibers" is used herein to mean that the crosslinks are primarily intrafiber instead of interfiber. The term "intrafiber" means a polycarboxylic acid molecule that is reacted only with a molecule or molecules of a single fiber instead of between separate fiber molecules.% Mol of the polycarboxylic acid crosslinking agent is calculated on a molar base of cellulose glucose anhydride which reacts with the fibers, being determined by the following procedure: first a sample of crosslinked fibers is washed with sufficient hot water to remove any unreacted crosslinking agent and catalyst. Next, the fibers are dried to an equilibrium moisture content. The free carboxyl group content is then determined, essentially according to the T.A. P.P. I. T237 OS-77. The% mol of the reacted polycarboxylic acid crosslinking agent is then calculated based on the considerations that a carboxylic group is left unreacted in each polycarboxylic acid molecule, that the fibers before reacting have a carboxyl content of 30 meq. / kg, and that no new carboxyls are generated on the cellulose molecules during the crosslinking process apart from the free carboxyls on the crosslinking portions, and that the molecular weight of the crosslinked pulp fibers is 162 (i.e. anhydrous glucose unit). The term "ester linkage", as used herein, means that the polycarboxylic acid crosslinking agents react with hydroxyl groups of the fiber component molecules to form the ester linkages. The term "acid bases" is used herein to mean the weight of citric acid which gives the same number of reactive carboxyl groups, * as provided by the currently used polycarboxylic acid, with the carboxyl reactant groups which are the groups Carboxyxil reactants minus one per molecule. The term "reactive carboxyl groups" is defined below. The term "applied on a dry fiber basis, means that the percentage that is established by a relationship, where the denominator is the weight of the cellulosic fibers present if they were dry, (ie, without moisture content).

The "water retention values", set forth herein, are determined by the following procedure: a sample of about 0.3 g to about 0.4 g of fibers (i.e., about 0.3 g to about 0.4 g portion of the fibers) for which the water retention value is being determined is soaked in a container covered with approximately 10 ml of distilled or deionized water at room temperature for approximately 15 and approximately 20 hours.The soaked fibers are collected on a filter and transferred to a wire mesh basket of 80, supported approximately 3.81 cm above a lower part of 60 mesh screen of a centrifugal tube.The tube is covered with a plastic cover and the sample is centrifuged at a relative centrifugal force of 1,500 at 1,700 gravities for 19 to 21 minutes The centrifuged fibers are then removed from the basket and weighed. ~ "~ are dried at a constant weight at 105 ° C and returned to weigh in. The water retention value (WRV) is calculated as follows: WRV = (W-D) X 100 D where, W = the wet weight of the centrifuged fibers; D = the dry weight of the fibers; and W-D = the weight of the water absorbed.

The water retention value remains the same regardless of whether or not the fibers have surface active agent distributed thereon in the amounts applicable to the present invention. The 5K density test is a measure of the stiffness of the fibers and the dry elasticity of a structure made from the fibers (ie, the ability of the structure to expand by releasing the compressive force applied, while the fibers are in a substantially dry condition), and is carried out according to the following procedure: a square pad placed in air of four inches by four inches, having a mass of about 7.5 g of the fibers for which Dry elasticity is determined, and compressed in a dry state by a hydraulic press at a pressure of 5,000 psi, and the pressure is released quickly. The pad is reversed and the pressure is repeated and released. The thickness of the pad is measured after pressing with an unloaded gauge (the thickness was tested in Ames thickness). Five thickness readings are taken, one at the center and 0.001 inches at each of the four corners and the five values are averaged. The pad is cut to four inches by four and then measured. The density after pressing is then calculated as mass / (area x thickness). This density is denoted as the 5K density in the present. The lowest of the values of the 5K density test, ie the density after the pressure occurs, the greater the fiber stiffness and the greater the dry elasticity. The drip capacity test herein is a combined measure of absorbency and absorbent capacity and is carried out here by the following procedure: a square pad placed in air of four inches by four inches having a mass is prepared of approximately 7.5 gr, from the fibers for which the drip capacity is being determined and is placed on a screen mesh. Synthetic urine is applied to the center of the pad at a rate of 8 ml / sec. The flow of synthetic urine is stopped when the first drops of synthetic urine escape from the bottom or side of the pad. The drip capacity of the difference in mass of the pad before and subsequent to the introduction of synthetic urine divided by the mass of the fibers, on dry granulated base. The majority of the drip capacity is, the best of the absorbing properties. The conduction velocity test of the present is a measure of the speed at which the liquid is conducted through a pad of fibers that is tested and is determined here by the following procedure: a square pad placed in air is prepared of four by four inches that has a mass of approximately 3.5 g and a density of 0.2 g / cc, from fibers for which the fluid conduction velocity is determined. The test is carried out in a fluid conduction velocity tester. The conduction velocity tester comprises a container, two lower electrodes with pins for inserting through a sample, two upper electrodes with pins for inserting through a sample, two vertically oriented plates for placement in the container, and a controller of time to start when either of the two adjacent pins on the lower electrodes are in liquid contact and to stop when either of the two adjacent pins on the upper electrodes are in contact with the liquid. The synthetic urine is placed in the container of the fluid conduction velocity tester to provide a one-inch depth of synthetic urine there. The fiber pad that is tested, is placed between the fluid conduction velocity tester plates with the lower electrode pins that are inserted through the total thickness of the pad 7/12 inches from the bottom of the pad and the pins of the upper electrodes being inserted through the full thickness of the pad of 2 1/12 inches, from the bottom of the pad and the assembly is inserted towards the body of synthetic urine in the tester container of such way, the bottom of a third of an inch extends towards the synthetic urine. The fluid conduction velocity in cm / s is 3.81 (the distance between the upper and lower electrodes is in centimeters), divided by the conduction time from the lower electrodes in the upper electrodes as indicated by the setter of time. The most extensive driving speed, the most fluid driving. The wet compressibility test herein is a measure of moisture response and absorbency in a structure made from the fibers for which the property is being determined, and is carried out by the following procedure: a four by four square inch pad placed in air, leaving approximately 7.5 g, from the fibers that are tested. The density to the pad is adjusted to 0.2 g / cc with a press. The pad is loaded with synthetic urine at ten times its dry weight, or up to the point of saturation, whichever is less. A compression load of 0.1 PSI is applied to the pad. After about 60 seconds, during which time the pad is balanced, then the compression load is increased to 1.1 PSI. The pad is allowed to reach equilibrium and then the compression load is reduced to 0.1 PSI. The pad is then allowed to reach equilibrium, and the thickness is measured. The density for the pad is calculated at the second load of 0.1 PSI, based on the thickness measured after the pad is balanced, after the compression load is reduced to 0.1 PSI. The empty volume reported in cc / g, is then determined. The empty volume is the reciprocal of the density of the pad in number minus the volume of fiber (0.95 cc / g). This empty volume is denoted as the number compressibility in the present. Very high values indicate a greater response to humidity. The runoff velocity test is a measure of the percentage of cases in which babies experience run-off in night use and is carried out by the following procedure: Medium-sized Pampers are modified to include an acquisition member and rectangular fluid distribution of 3 inches by 10 inches by approximately one quarter of an inch between the top sheet and the fluid absorbent core, with the front edge of the width of the distribution and fluid acquisition member being positioned two to three inches down the front waist of the diaper. The modified product is given to the breasts of 20 male babies, usually dressed in their disposable diapers of medium size. Breasts use diapers for nighttime use and check babies once they wake up in the morning and report if babies experienced runoff. The results are reported in percentage of babies, completing the test who are known to experience runoff when checked after nighttime use.

The skin moisture test here, is a measure of the percentage of cases of babies found to be or to be wet after nighttime use and is carried out by the following procedure: Pampers are modified to average size to include a distribution member of fluid acquisition 3-inch by 10-inch by about a quarter-inch between the top sheet and the fluid-absorbent core with the front edge of the member's width with acquisition and distribution of fluids that is placed 2 to 3 inches below of the front waist of the diaper. The modified product is given to the breasts of 20 male babies, normally dressed in disposable diapers of medium size. The moms use the diapers for night use, and check the babies when they wake up in the morning and report if the babies are wet. The results are reported in percentages of babies, completing the test who are known to be, r > wet, when checked after nighttime use. The jet capacity test in the present is a measure of how much fluid is immediately released to the base core of a diaper through the acquisition and distribution member when charging and how much fluid remains in the acquisition and distribution member, then that equilibrium has been allowed to be achieved and is carried out by the following procedure: two Pampers diapers of medium size are used in each test. The upper sheets are removed and the diapers are placed with the baby's side facing up. In the proven fluid acquisition and distribution members are rectangular in top view and are 3 inches by 10 inches by about ¼ inch with the front edge of the width of the fluid acquisition and distribution member being placed from 2 to 3 inches down the front diaper waist. Synthetic urine is measured on the center of the upper surface of the fluid distribution and acquisition member through a tube with its outlet opening, placed approximately 3 inches above the upper surface of the fluid acquisition and distribution member at its center. Synthetic urine is measured on the upper surface of the fluid acquisition and distribution member in 50 ml batches at a rate of 10 ml per second. One of the fluid acquisition and distribution members is immediately removed after 50 ml of fluid has been loaded and weighed and then returned to the diaper. The other is allowed to remain untouched for 15 minutes, in such a way that the drained fluid is allowed for this period, and is then removed and weighed to determine the final amount of fluid remaining in it, before loading another 50 ml. of synthetic urine, and is then reguresado to the diaper for the load of another 50 ml of synthetic urine. This procedure is then repeated with 50 ml more of synthetic urine. This is continued until a total of 400 ml of synthetic urine is added, with measurements carried out, as described above with each 50 ml of load. Lower values in the previous measurements indicate faster acquisitions. Values lower than 15-minute measurements indicate faster partitioning (ie, faster transfer of fluid from one layer to another when the two layers are in contact). The acquisition speed test hereof is a measure of the acquisition speed and the acquisition amount over a period of time, and is carried out by the following procedure: Pampers are modified average size to include an acquisition member and distribution of rectangular top view fluids of 3 inches by 10 inches, by approximately one quarter of an inch between the top sheet and the fluid absorbent core, with a front edge of the width of the fluid acquisition and distribution member being positioned 2 to 3 inches below the front waist of the diaper, the modified diaper is placed on a piece of foam and a tester base with the baby's side of the diaper facing up. A cylinder approximately 1 3/4 inches in diameter, open at the top and bottom is placed against the top surface of the top sheet above the center of the fluid acquisition and distribution member. A weight is applied to provide a pressure of 0.4 psi to the upper surface of the top sheet. Four loads of 50 ml of synthetic urine are measured in the cylinder, each at a rate of 5 ml per second, with an equilibrium time of 5 minutes allowed for each of the loads, that is, the four loads are applied each 5 minutes apart in such a way that the total time of the test is approximately 20 minutes. The acquisition time is measured for loading (ie, the time between the start of the measurement and when the fluid disappears from the cylinder), and the speed of - * - acquisition in ml / sec, is calculated at each of the loads dividing the 50 ml by the acquisition time. Then the acquisition potential Ao and the acquisition speed constant K are calculated using the equation In A = (-1 / K) (L) + In Ao where A is the acquisition speed in ml / sec of 50 ml of fluid, Ao is the acquisition potential, L is the accumulated load, K is the acquisition constant (theoretical load at which approximately half of the acquisition potential is reached), A and L are data and Ao and K are calculated. The highest of the values for Ao, will be faster acquisition. The highest value for K is greater than acquisition over time. The term "synthetic urine" is used herein to mean a solution prepared from water and 10 g of sodium chloride per liter of water and 0.52 ml of a 1% aqueous solution of Triton X100 (a surfactant is octylphenoxypolyethoxy ethanol, available from Rohm &Haas Co.) per liter of tap water. Synthetic urine should be at 25 + 1% ° C when used. The term "upper" is used herein in relation to an absorbent core which means the portion of the absorbent core closest to the top sheet of the article, and the term "lower" is used in the present relationship to an absorbent core. which means the portion of the absorbent core closest to the back of the article. The density values of the present are calculated from the basis weight and the carp calibrator measured under a confining pressure of 0.2 psi (1.43 kPa). The air-laid pads referred to herein are made as follows: placement in air is carried out at an air placement of approximately 120 g of fiber in a 14 by 14 inch square on a piece of tissue and a second piece of tissue, is then placed on top of the mass placed in air to form a pad. The pad is pressed and trimmed in 4 by 4 inch squares. The term "defibration" and "defiberation" are used herein to refer to any process that can be used to mechanically separate fibers into substantially individual forms, although they are already in that form, ie the stage or steps of treating mechanically the fibers, either individually or in a more compacted form, where the treatment or treatments of fiber separation in a substantially individual form if they are not already in that form, and / or impart curling and twisting to the fibers in a dry state .

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 represents a perspective view of a disposable diaper of the present invention. Figure 2 is a plot of fluid retention against load for the results of the jet capacity test for the example with the data that are normalized by regression analysis.

DETAILED DESCRIPTION OF THE INVENTION First we will address the acquisition and distribution member of the present. As previously indicated, it has a dry density ranging from 0.03 to 0.20 g / cc and consists essentially of interlaced, individualized cellulosic fibers, which have a quantity of crosslinking agent of C2-C9 polycarboxylic acid, which is reacted therein. in the crosslinker form of the intrafiber ester to provide a water retention value from about 25 to 60, and having substantially evenly distributed therein from about 0.0005% to 1% by weight, on a dry fiber basis, of active surface agent. The patent E.U.A. 5,137,537 indicates that the amount of C2-C9 polycarboxylic acid crosslinking agent, reacted with the fibers that provides a water retention value of about 25 to 60 can be from about 0.5 mol% to about 10 mol%, calculated on a molar base of anhydroglucose cellulose. Preferably, it has a dry density that varies from 0.06 to 0.08 g / cc. Preferably, it is substantially free of any component that interferes with the ability of the member to distribute fluids (eg, urine or menstruate) to an adjacent hydrophilic layer (e.g., a fluid storage area). Preferably the crosslinked cellulose fibers have an amount of crosslinking agent of C2-C9 polycarboxylic acid, reacted therein in the crosslinker form of the intrafiber ester to provide a water retention value ranging from 28 to 50. As previously indicated, the active surface agent is preferably present in the fibers in amounts up to about 0.15. % by weight, on a dry fiber basis, that is, in an amount ranging from 0.0005% to 0.15%, by weight, on a dry fiber basis. Most preferably the active surface agent is present in the fibers in an amount ranging from about 0.001% to 0.20% by weight, on a dry fiber basis. We will now turn to cellulosic fibers that are subject to crosslinking to provide the individualized, crosslinked cellulosic fibers herein. Cellulosic fibers of various natural origins are useful. Digested fibers are preferably used from soft pulp, hard pulp or cotton waste. We will now refer to the crosslinking agents of C2-C9 polycarboxylic acid. These are organic acids that contain two or more carboxyl groups (COOH) and 2 to 9 carbon atoms in the chain or in the ring to which the carboxyl groups are linked; the carboxyl groups are not included when determining the number of carbon atoms in the chain or ring (for example, the acid, 1,2,3, tricarboxylic propan, would be considered to be a polycarboxylic acid of C3, which contains three groups carboxyl and 1,2,3,4 butane tetracarboxylic acid should be considered to be a C4 polycarboxylic acid, containing four carboxyl groups). More specifically, the C2-C9 polycarboxylic acids, suitable for use as crosslinking agents in the present invention, include aliphatic and alicyclic acids, either saturated or olefinically unsaturated with at least three, and preferably more carboxylic groups per molecule or with two carboxyl groups per molecule if the carbon-carbon double bond, beta, is present to one or both carboxyl groups. A further requirement is that to be reactive in the esterification of hydroxyl cellulose groups, a given carboxyl group in an aliphatic or alicyclic polycarboxylic acid, must be separated from a second carboxyl group by not less than two carbon atoms and not more than three. carbon atoms. Without being bound by the theory, from these requirements it appears that a carboxyl group which is reactive, must be capable of forming a cyclic 5- or 6-membered anhydride ring with a neighboring carboxyl group in the polycarboxylic acid molecule. Where two carboxyl groups are separated by a carbon-carbon double bond, or both are connected to the same ring, the two carboxyl groups must be in the cis configuration, in relation to each other if they are to interact in this way. Accordingly a reactive carboxyl group is a carboxyl group separated from a second carboxyl group by not less than 2 carbon atoms and not more than 3 carbon atoms, if where two carboxyl groups are separated by a carbon-carbon double bond, or are both connected to the same ring, a reactive carboxyl group, must be in the cis configuration to another carboxyl group. In aliphatic polycarboxylic acids containing three or more carboxyl groups per molecule, a hydroxyl group is attached to an atom of the alpha carbon to a carboxyl group not interfering with the esterification and crosslinking of the cellulosic fibers by the acid. Therefore, polycarboxylic acids, such as citric acid (also known as 2-hydroxy-1,3, propanedicarboxylic acid), and monosuccinic tartrate acids, are suitable as crosslinking agents in the present invention. The aliphatic or alicyclic C2-C9 polyocarboxylic acid crosslinking agents may also contain an oxygen or sulfur atom or atoms in the chain or ring to which the carboxyl groups are attached. Accordingly, polycarboxylic acids such as oxydisuccinic acid, also known as 2,2'-oxybis (butano-dioic), thiodisuccinic acids, and the like, this means that they are included within the scope of the invention. For purposes of the present invention, oxydisuccinic acid would be considered to be a C4 polycarboxylic acid, containing four carboxyl groups. Examples of specific polycarboxylic acids falling within the scope of the present invention include the following: maleic acid, citraconic acid, also known as methyl maleic acid, citric acid, itaconic acid, also known as methylenesulic acid, tricarboxylic acid also known as acid 1,2,3-propanedicarboxylic acid, transaconitic acid also known as trans-1-phenyl-1,2,3-tricarboxylic acid, 1,2,3,4-butane-tetracarboxylic acid, cis-1, 2, 3, 4 acid -cyclopentantetracarboxylic acid, mellitic acid, also known as benzenecarboxylic acid, and oxydisuccinic acid, also known as 2, 2'-oxybis (butanedioic acid). The above list of "specific polycarboxylic acids" is for exemplary purposes only, and it is not intended that they are all included in. Importantly, the crosslinking agent must be capable of reacting with at least two hydroxyl groups in the vicinity of cellulose chains in a simple cellulose fiber., the C2-C9 polycarboxylic acids, used herein are aliphatic, and saturated, and contain at least three carboxylic groups per molecule. A group of preferred polycarboxylic acid agents for use with the present invention include citric acid also known as 2-hydroxy-l, 2,3-propanedicarboxylic acid, 1,2,3-propanedicarboxylic acid and 1,2,3,4-acid. butane tetracarboxylic Citric acid is especially preferred, because it has provided fibers with high levels of wettability, absorbency and elasticity, and is safe and non-irritating to human skin, and has provided stable crosslinking bonds. In addition, citric acid is available in large quantities at relatively low prices, thereby making it commercially feasible as the crosslinking agent. Another group of preferred crosslinking agents for use in the present invention include C2-C9 polycarboxylic acids, which contain at least one oxygen atom in the chain to which the carboxylic groups are attached. Examples of these compounds include monosuccinic tartrate acid having the structural formula and disuccinic tartrate acid that has the structural formula A more detailed description of monosuccic tartrate acid, disuccinic tartrate acid, and salts thereof, can be found in Bushe et al. In U.S. Pat. No. 4,663,071, issued May 5, 1987, incorporated herein by reference. Those skilled in the area of polycarboxylic acids will recognize that the aliphatic and alicyclic C2-C9 polycarboxylic acid crosslinking agents described above can be reacted in a variety of ways to form the crosslinked fibers used herein, as the free acid form, and salts thereof. Although the free acid form is preferred, all of such forms are so meant to be included within the invention plan. We now point to active surface agents. The active surface agent distributed over the crosslinked titanium fibers may be a surfactant, cationic or anionic, zwitterionic, ampholitic, nonionic, water soluble agent, or combinations thereof. Nonionic surfactants are preferred. Preferred surface active agents "****" of a group (sold under the Trade Name of Pluronic and described hereinafter), provide a surface tension at a level of 0.1% in water at 25 C ranging from 42 to 53 dines / cm. Preferred active surface active agents of another type (sold under the tradename Neoldol and described herein below) provide a surface tension at a level of 0.1% in water at 76 F of 28 to 30 dynes / cm. A class of nonionic surfactants consists of polymeric, polyoxyethylene polyoxypropylene compounds based on ethylene glycol, propylene glycol, glycerol, trimethylolpropane or ethylenediamine as the hydrogen compound of initiator reagent. Preferred surfactants in this class are the compounds formed by the ethylene oxide condensate, a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The average molecular weight of the surfactant usually varies from about 1,000 to 15,000 gr / mol and the molecular weight of the hydrophobic portion generally falls on the scale of about 900 to 4,000 gr / mol. Preferably, the average molecular weight of the surfactant varies from about 1,000 to 5,000 g / mol, the molecular weight of the hydrophobic poly (oxy-propylene) varies from 900 to 2,000 g / mol, and from the hydrophilic poly (oxyethylene) unit , an amount ranging from 10% to 80% by weight of the total molecule is present. Synthetic nonionic surfactants are commercially available by the Trade Name of Pluronic, and are supplied by Wyandotte Chemicals Corporation. Especially preferred nonionic surfactants are Pluronic L31 (the average molecular weight of the surfactants of 1,100 g / mol, the molecular weight of the hydrophobic poly (oxypropylene) of 950 g / mol, and 10% of the poly (oxyethylene) unit). hydrophilic in weight in the total molecule), Pluronic L35 (average molecular weight of 1,900 g / mol, hydrophobic poly (oxypropylene) molecular weight of 950 g / mol, and 50% of the hydrophilic poly (oxyethylene) unit by weight in the total molecule), Pluronic L62 (average molecular weight of surfactant of 2,500 g / mol, hydrophobic poly (oxypropylene) molecular weight of 1,750 g / mol, and 20% of the hydrophilic poly (oxyethylene) unit by weight in the total molecule), and Pluronic F38 (average molecular weight of surfactant of 4,700 g / mol, hydrophobic poly (oxypropylene) molecular weight of 950 g / mol, 80% of the hydrophilic poly (oxyethylene) unit by weight in the molecule total). The surface tensions for aqueous solutions at 0.1% of these 25 ° C surfactants are as follows: Pluronic L31, 46.9 dynes / cm; Pluronic L35, 48.8 dines / cm; Pluronic L62, 42.8 dines / cm; Pluronic F38, 52.2 dines / cm, the most preferred is Pluronic L35. Another class of nonionic surfactants consists of the condensation products of primary or secondary aliphatic alcohols or fatty acids having 8 to 24 carbon atoms, either straight chain or branched chain configurations with from 2 to about 50 moles of ethylene oxide per mole of alcohol. Aliphatic alcohols comprising from 12 to 15 carbon atoms are preferred with from about 5 to 15, most preferably from about 6 to 8 moles of ethylene oxide per mole of aliphatic compound. The preferred surfactants are - >U prepare from primary alcohols that are either linear such as those derived from natural fats or prepared by the Ziegler process, from ethylene, for example myristyl, cetyl, or stearyl alcohols, for example Neodoles, (Neodol, which is a Commercial Name of Shell Chemical Company), or partially branched, such as Lutensols, (Lutensol, which is a Trade Name of BASF) and Dobanols (Dobanol which is a Trade Name of Shell), which have approximately 25% of 2 -metabolic branched, or Synperonics, which are understood to have approximately 50% of 2-methyl r amides (Synperonic, which is nun Commercial Name of ICI), or primary alcohols that have more than 50% of the branched chain structure, sold under the Commercial Name of Lial, by Liquichmica. Specific examples of nonionic surfactants falling within the scope of the invention include Neodol 23-6.5, Neodol 25-7, Dobanol 45-4, Dobanol 45-7, Dobanol 45-9, Dobanol 91-2.5, Dobanol 91- 3, Dobanol 91-4, Dobanol 91-6, Dobanol 91-8, Dobanol 23-6.5, Synperonic 6, Synperonic 14, condensation products of coconut alcohol, with an average of between 5 and 12 moles of ethylene oxide per mole of alcohol, the alkyl portion of the coconut having from 10 to 14 carbon atoms, and the condensation products of the bait alcohol, with an average of between 7 and 12 moles of ethylene oxide per mole of alcohol, the bait containing between 16 and 22 carbon atoms. The secondary alkyl alkyl ethoxylates are also suitable in the present compositions, especially those ethoxylates of the Tergitol series, having from about 9 to 15 carbon atoms in the alkyl group and up to about 11, especially from about 3 to 9 residues. of ethoxy per molecule. Especially preferred nonionic surfactants of this class are Neodol 23-6.5 which is a C12-C13 linear alcohol, ethoxylated with an average of 6.7 moles of ethylene oxide per mole of alcohol and has a molecular weight of 488 g / mol and Neodol 25-7, which is an ethoxylated C12-C15 linear alcohol with an average of 7.3 moles of ethylene oxide and has a molecular weight of 524 g / mol. The surface tension for 0.1% solutions of Neodol 23-6.5 and Neodol 25-7 at 76'F, in distilled water are respectively 28 dynes / cm and 30 dines / cm. Another class of nonionic surfactants consists of the polyethylene oxide condensates of alkylphenols, for example condensation products of alkylphenols having an alkyl group containing from 6 to 20 carbon atoms, either in a straight chain or in a of branched chain, with ethylene oxide, said ethylene oxide, being present in equal amounts of 4 to 50 moles of ethylene oxide per mole of alkyl phenol. Preferably the alkyl phenol contains from about 8 to 18 carbon atoms in the alkyl group, and from about 6 to 15 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in said compounds can be derived, for example, from polymerized propylene, diisobutylene, octene and nonene. Other examples include condensates of dodecylphenol with 9 moles of ethylene oxide per mole of phenol, condensates of dinonylphenol with 11 moles of ethylene oxide per mole of phenol; condensates of nonylphenol with 11 moles of ethylene oxide per mole of phenol; condensates of nonylphenol and di- "" isoctylphenol with 13 moles of ethylene oxide. Another class of nonionic surfactants are ethoxylated alcohols or acids or condensates of polyoxypropylene, polyoxyethylene which are capped with propylene oxide, butylene oxide, and / or short chain alcohols and / or short chain fatty acids, for example those containing from 1 to about 5 carbon atoms, and mixtures thereof; another class of nonionic surfactants are non-ionic semi-polar surfactants including water-soluble amine oxides containing an alkyl apportion of about 10 to 18 carbon atoms, and two selected portions of group consisting of alkyl portions and hydroxyalkyl from about 1 to 3 carbon atoms; water-soluble phosphine oxides containing an alkyl portion of about 10 to 18 carbon atoms and two portions selected from the group consisting of alkyl groups and hydroxyalkyl groups, containing from about 1 to 3 carbon atoms; and its ague soluble oxides containing an alkyl portion of about 10 to 18 carbon atoms and one selected from the group consisting of alkyl and hydroxyalkyl portions of about 1 to 3 carbon atoms. Ampholytic surfactants include aliphatic derivatives, or aliphatic derivatives of heterocycle, secondary and tertiary amines in the aliphatic portion can be straight or branched chain and where one of the aliphatic substituents contains from about 8 to 18 carbon atoms and by at least one aliphatic substituent contains an anionic water solubilizing group. Zwitterionic surfactants include derivatives of aliphatic, phosphonium and sulfonium quaternary ammonium compounds, in which one of the aliphatic substituents contains from about 8 to 18 carbon atoms. Useful anionic surfactants include water soluble salts of higher fatty acids, i.e., soaps. These include alkali metal soaps, such as sodium, potassium, ammonium, and alkylolammonium salts of higher fatty acids containing from about 8 to 24 carbon atoms and preferably from about 12 to 18 carbon atoms. The soaps can be made by direct saponification of oil grease or by "neutralization of free fatty acids. Particularly useful are the sodium and potassium salts of the fatty acid mixtures, derived from coconut oil and bait, that is, coconut soap and sodium or potassium bait. Useful anionic surfactants also include water-soluble salts, preferably the alkali metal, ammonium and alkylammonium salts of organic sulfuric reaction products, which have in their structure Molecular "" "an alkyl group consisting of about 20 carbon atoms and a sulfonic acid or a sulfuric acid ester group. (Included in the term "alkyl" is the alkyl portion of acyl groups), examples of this group of synthetic surfactants, are sodium alkyl potassium sulfate, especially those obtained by sulfation of higher alcohols (carbon atoms C8- C18, such as those produced by the reduction of the glycerides of the bait or coconut oil, and the alkylbenzene potassium sulfonates, in which the alkyl group contains from about 9 to 15 carbon atoms, straight chain or chain configuration branched, for example, those of the type described in US Pat. Nos. 2,220,099 and 2,477,383. Particularly valuable are linear straight-chain alkylbenzene sulfonates in which the average number of carbon atoms in the alkyl group is from about 11 to 13. , abbreviated as C11-C13 LAS.

Other anionic surfactants herein, are the glyceryl alkyl sodium sulphonates, especially those ethers of higher alcohols derived from coconut oil and bait; the fatty acid monoglyceride sulfates and sulphonates of sodium coconut oil; potassium or sodium salts of ether sulfates, of ethylene oxide alkylphenol containing about 1 to 10 units of ethylene oxide per molecule and where the alkyl groups contain from about 8 to 12 carbon atoms; sodium or potassium salts of alkyl ethylene oxide ether sulfate containing from about 1 to 10 ethylene oxide units per molecule, and wherein the alkyl group contains from about 10 to about 20 carbon atoms. Other anionic surfactants useful herein, include water soluble salts of alphasulfonated fatty acid esters containing from about 6 to 20 carbon atoms in the fatty acid group and from about 1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxyalkane-sulfonic acids containing from about 2 to 9 carbon atoms in the acyl group and from about 9 to 23 carbon atoms in the alkane portion; water-soluble salts of olefin and paraffin sulfonates containing from about 12 to 20 carbon atoms; and alean beta-alkyloxy sulfonates containing from about 1 to about 30 carbon atoms in the alkyl group and from about 8 to 20 carbon atoms in the alkane portion. The cationic surfactants herein, comprise a variety of compounds characterized by one or more hydrophobic organic groups in the cation and generally by a quaternary nitrogen associated with the acid moiety. Pentavalent nitrogen ring compounds are also considered quaternary nitrogen compounds. Suitable anions are allogenides, methyl sulfate and hydroxyl. Tertiary salines may have characteristics similar to cationic surfactants in solutions of PH values of less than about 8.5. A more complete description of these and other cationic surfactants useful herein can be found in the US patent. No. 4,228,044, Cambre, issued October 14, 1980, incorporated herein by reference. As previously indicated, the active surface agent is preferably applied to the cellulosic fibers before the crosslinking reactions occur with the C2-C9 polycarboxylic acid crosslinking agent. Most preferably, the individualized crosslinked cellulosic fibers with active surface agent therein are prepared in a process comprising curing the uncrosslinked cellulosic fibers with from 1% to 15%, preferably 3% to 12%, of crosslinking agent. of polycarboxylic acids, C2-C9, by weight on the basis of citric acid applied on a dry fiber basis, and from about 0.005% to 1%, preferably from 0.01% to 0.2% of active surface active agent by weight, applied on a dry fiber base, over it, to cause the polycarboxylic acid crosslinking agent to react with the fibers cellulosic and forms ester crosslinking between the celluloses molecules, to form said cellulosic fibers crosslinked with active surface agent therein, without the washing of the crosslinked fibers or the bleaching and washing of the crosslinked fibers.

We will now refer in greater detail to the aforementioned highly preferred process where the uncrosslinked cellulosic fibers are heated with from 1% to 15%, preferably from 3% to 12%, of C2-C9 polycarboxylic acid crosslinking agent, in weight, on a citric acid base applied on a dry fiber basis, and from 0.005% to 1%, preferably from 0.01% to 0.2% active surface active agent, by weight, applied on a dry fiber basis, therein , to remove any moisture content and to cause the polycarboxylic acid crosslinking agent to react with the cellulosic fibers and form ester lattices between the cellulose molecules, i.e., produce the cure, to form cross-linked fibers with active surface agent in them that are the essential component of the fluid acquisition and distribution member of the present. This step is easily carried out on uncrosslinked cellulosic fibers having a moisture content ranging from 0% to about 70%, preferably varying from 30% to 40%, in an unlimited form or in sheet form. In the case of fibers treated in an unlimited form, for example, defibrated fibers (fluff), a part of removal of the water content from the heating step can be carried out in a first apparatus to dry to a consistency varying from 60% to 100%, for example, by a method known in the art as instant drying. This is carried out by transporting the fibers in a hot air stream, for example, at an inlet air temperature ranging from 93 ° C to 399 ° C, preferably at an air inlet temperature of 149 ° C at 288 ° C, until the object consistency is reached. This imparts an additional twist and twist to the fibers while the water is removed from them. Although, the amount of water removed by this drying step can be varied, it is believed that instant drying at high consistencies on the scale of 60% to 100% provides a higher level of twisted and curled fiber that makes instant drying a a consistency at the bottom of the scale 60% -100%. In the preferred embodiments, the fibers are dried at about 85% -95% consistency. The instant drying of the fibers to a consistency, such as 85% -95%, in a larger part of the 60% -100% scale, reduces the amount of drying that must be carried out following the instant drying. The subsequent part of the heating step, or all of the heating step if instantaneous drying is omitted, may involve heating for a period ranging from 5 seconds to 2 hours at a temperature that varies from 120 ° C to 280 ° C (temperature of the air in the heater), preferably at a temperature ranging from 145 ° C to 190 ° C (air temperature in the heater) for a period ranging from 2 to 60 minutes in a continuous air-through apparatus drying / curing (hot air passes perpendicularly through a traveling fiber bed) or in a static oven (the fibers and the air remains immobile is a container with a static heating medium), or other heating apparatus, to remove any remaining moisture content and cause the crosslinking reaction that occurs to the fibers becoming stiff as a result of intrafiber crosslinking. The heating should be such that the temperature of the fibers does not exceed approximately 227 ° C since the fibers can explode in flames at this temperature. The aggregate is heated for an effective period of time to remove any remaining moisture content and cause the crosslinking agent to react with the cellulosic fibers. The extent of the reaction depends on the drying of the fiber, the time in the heating apparatus, the temperature of the air in the heating apparatus, the pH, the amount of the crosslinking agent and the method used to heat. Crosslinking at a particular temperature will occur at a higher value for fibers of a certain initial moisture content with drying / curing of air through, continuous, that with drying / curing in a static oven. Those skilled in the art will recognize that there are countless temperature-time relationships. The temperature from about 140 ° C to about 165 ° C (air temperature in the heating apparatus) for periods of between about 30 minutes and 60 minutes, under static atmospheric conditions will generally provide acceptable drying / curing efficiencies for fibers having contents humidity less than 10%. It will also be appreciated by those skilled in the art that at elevated temperatures and forced air convection (air heating through) the time required decreases. Accordingly, temperatures that range from about 170 ° C to about 190 ° C (air temperature in the heating apparatus) for periods of between about 2 minutes and 20 minutes, in an air-through furnace will also generally provide acceptable efficiencies drying / curing for fibers that have moisture contents of less than 10%. In an alternative to complete the heating after an initial step of instantaneous drying, the instant and curing drying is carried out or the curing is only carried out if the previous instant drying provides 100% effluent consistency, by tracing the effluent from the instant dryer (at 90 to 100% consistency) to a cyclone separator that separates the air from the air / fiber mixture from the instant dryer, discharging the fibers from the cyclone separator into a stream of hot air (eg at 204 ° C) ) in a duct that contains at least one U-shaped portion, which leads to the fibers through the duct thereby providing a travel path that provides sufficient residence time to cause the removal of any moisture content and to cause the esterification reaction occurring between the fibers and C2-C9 polycarboxylic acid, and discharging from the duct in a cyclone separator to stopping the esterified fibers, and it is needed or desired, to cause additional crosslinking which occurs, for example, in a subsequent air oven through a static oven. The apparatus for the initial instantaneous drying step can also be of the same type of apparatus as described here (a cyclone separator, hot air treatment duct and cyclonic separator) in such a way that two or more assemblies for said apparatuses are used in series as required by the need to provide fresh dry air during the course of drying and curing. The resultant crosslinked fibers (i.e., produced by any of the alternatives described above for the application of the heating step to the fibers in an unlimited form) are optionally moistened, for example, by spraying with water to provide a moisture content of 5 to 10%. fifteen%. This makes the fibers more resistant to damage that are at risk of occurring due to subsequent handling or due to processing in the manufacture of absorbent products from the fibers. Referring now to the case where the heating step is carried out on the fibers in the sheet form to dry the fibers and cause the crosslinking reactions to occur. The same times and temperatures are applied as described above for the fibers in unlimited form. Preferably, heating is carried out at 145 ° C to 190 ° C (air temperature in the heating apparatus) for 2 to 60 minutes. After curing, the crosslinked fibers are optionally wetted at a moisture content of 5 to 15% to provide resistance to handling damage and optionally converted to substantially individualized form. The conversion to the individualized form can be carried out using a commercially available disc refiner or by treatment with a fiber spreading apparatus, such as that described in the U.S. Patent. No. 3, 987,968, incorporated herein by reference. One effect of curing in the sheet form is that the fiber to fiber bond restricts the twist and curl fibers compared to where the individualized crosslinked fibers are made with curing under substantially unrestricted conditions. Fibers made in this manner would be expected to provide structures exhibiting lower absorbency and wettability than in the case of fibers cured in an unrestricted manner. Now we will refer to a method to form input material for the heating step. This at a minimum comprises contacting the non-crosslinked fibers with aqueous crosslinking compositions consisting essentially of C2-C9 polycarboxylic acid crosslinking agent and active surface active agent. The contacting is carried out on non-crosslinked fibers with an aqueous crosslinking composition containing C2-C9 polycarboxylic acid crosslinking agent and active surface agent in an amount to provide from 1% to 15%, preferably 3% by weight. 12%, thereof, by weight, in a citric acid base applied on a dry fiber basis, in the fibers subjected to the heating step and the active surface agent in an amount to provide from 0.005% to 1%, preferably from 0.01% to 0.2, thereof, by weight, on a dry fiber basis, in the fibers subjected to the heating step. The lower limit in the surfactant is presumed that no more than 90% of the surfactant will be removed during the heating step or in other steps subsequent to the heating step and before using the cross-linked, active surface coated fibers in the member of acquisition and distribution of fluids of this. The pH for the aqueous crosslinking composition can be, for example, from 1 to 5.0. PH below 1 is corrosive to the processing equipment. PHs above 5 provide an impractically slow reaction rate. The esterification reaction will not occur at alkaline pH. The increase in pH reduces the reaction rate. Most preferably, the pH varies from 2 to 3.5. The pH is easily adjusted upwards if necessary by the addition of a base, for example, sodium hydroxide. The catalyst is preferably included in said aqueous crosslinking composition to increase the speed of the crosslinking reaction and to protect the gloss. The catalyst can be any that catalyzes the crosslinking reactions. Applicable catalysts include, for example, alkali metal hypophosphites, alkali metal phosphites, alkali metal polyphosphates, alkali metal phosphates, and alkali metal sulfates. Especially preferred catalysts are alkali metal hypophosphites, alkali metal polyphosphates, and alkali metal sulfates. The mechanism of the catalysis is known, although the catalysts may be functioning as regulating agents, keeping the pH levels within the desired scales. A more complete list of catalysts useful herein can be found in Welch et al., U.S. Pat. No. 4,820,307, issued April 1989, incorporated herein by reference. The selected catalyst can be used as the catalyst agent alone, or in combination with one or more other catalysts. The amount of catalyst preferably used is, of course, dependent on the particular type and amount of crosslinking agent and the reaction conditions of the cure, especially temperature and pH. In general, based on technical and economic considerations, catalyst levels of between about 5% by weight and about 80% by weight are preferred based on the weight of the crosslinking agent added to the cellulosic fibers. For example purposes, in the case where the catalyst used is sodium hypophosphite and the crosslinking agent is citric acid, a catalyst level of about 25% by weight, based on the amount of citric acid added, is preferred. In a highly preferred method, said contacting is carried out by transporting a sheet of high-lignin, uncrosslinked cellulosic fibers having a moisture content ranging from 0% to 10% through a body of said aqueous composition of crosslinking contained in a press roll holder (for example, cylinders of 30.35 cm in diameter and 182.10 cm in width) and through said fastener to impregnate said fiber sheet with said aqueous crosslinking composition and to produce on the side of the fastener outlet a sheet impregnated with fibers containing said aqueous crosslinking composition in an amount that provides 30% to 80% or more (eg, equal to 85% or 90% or equal to 95%), preferably 40% % to 70% consistency. The time of the fiber sheet in the body of the aqueous crosslinking composition as determined by the rotation speed of the press rolls, and the pressure of the rolls on the fiber sheet passing through it, are regulated such that the proper consistency and the amount of aqueous crosslinking composition is obtained as specified above. A typical pressure in the holder of the press cylinders is 45 psi and 803.60 Kg / m. The speed of the press cylinder is normally regulated to provide a time interval of the uncrosslinked fiber sheet within the body of the aqueous crosslinking composition ranging from 0.005 to 60 seconds, preferably from 0.05 to 5 seconds. In a less preferred alternate embodiment, the sheet of non-crosslinked fibers is impregnated with the aqueous crosslinking composition to provide the foregoing consistencies, by spraying. In any case, the liquid content of the impregnated sheet is optionally adjusted by pressure mechanically and / or by air drying. The sheet impregnated with fibers is preferably subjected to defibration before treatment in the heating step. Preferably, the defibration is done by a method where knot formation and distress are minimized, and fiber damage. Typically, a commercially available disk refiner is used. Another type of device that has been found to be useful for defibrating cellulosic fibers is the three-stage sponge device, described in US Pat. No. 3,987,968, issued to D.R. Moore and 0. A. Shields, October 26, 1976, said patent being incorporated herein by reference in this disclosure. The sponge device described in described in the patent E.U.A. No. 3,987,968 subjected the wet cellulosic pulp fibers to a combination of mechanical impact, mechanical agitation, agitation with air and a limited amount of air drying to create a substantially knot-free fluff. Other applicable methods of defibration include, but are not limited to, treatment in a Waring softener, which makes tangential contact with the fibers with a rotating wire brush and a hammer mill. Preferably, a stream of air is directed to the fibers during said defibration to assist in the separation of the fibers in substantially individualized form. In spite of the particular mechanical device used to form the fluff, the fibers are preferably mechanically treated as initially containing between about 40% and 70% moisture. The individualized fibers have imparted to this an improved degree of twisting and curling in relation to the amount of twist and curl naturally present in such fibers. It is believed that this additional twisted and curled improves the elastic character of the structures made from the crosslinked fibers. The result of the defibration is referred to herein as the defibrated mixture. The defibrated mixture is easy for the heating step. The impregnated sheet can be treated, for example, in a pre-trigger (for example, a screw conveyor) to disintegrate it, before the defibration. In a less preferred alternate embodiment, the fiber impregnated sheet is treated in the heating step without prior disintegration as described above, to produce a sheet of crosslinked cellulosic fibers, which optionally are subjected to defibration after the heating step. The contact of the non-crosslinked cellulose fibers with the aqueous crosslinking composition can also be carried out by forming a suspension of the non-crosslinked fibers in an unlimited form in the aqueous crosslinking composition, of consistency ranging from 0.1% to 20%, very preferably from 2% to 15%, and maintaining the suspension for about 1 to 240 minutes, preferably for 5 to 60 minutes. The suspension can be formed, for example, by causing a dry overlap sheet to disintegrate by agitating it in the aqueous crosslinking composition. The step of removing the liquid is normally close to being carried out to increase the consistency of a suitable stage for the heating step. This is preferably carried out by dehydrating (removing the liquid) to provide a consistency ranging from about 30% to 80%, most preferably ranging from about 40% to 50%, and optionally after further drying. By way of example, dehydration can be carried out by such methods as pressure or centrifugation mechanically. The product of dehydration is typically denoted as cake. Now changing to the stage where the cake can also be dried. This is typically carried out to provide a consistency within a consistency scale of about 35% to 80%, preferably to provide a consistency ranging from 50% to 70%, and is preferably performed under conditions such that it is not required the use of high temperatures for an extended period of time, for example, by a method known in the art as air drying. Excessively high temperatures and time in this step can result in fiber drying beyond 80% consistency, thus possibly producing an undesirable amount of fiber damage during a subsequent defibration. The term "reduced liquid mixture" as used herein refers to the product of the liquid removal step. The reduced liquid mixture is typically subjected to defibration performed as described above with respect to an impregnated sheet, except that the reduced liquid mixture is subjected to defibration in place of the impregnated sheet. The result of the defibration is referred to herein as the defibrated mixture. The defibrated mixture or the reduced mixture of liquid in the case where defibration is omitted, is ready for the heating step. The cured product should not be subjected to steps that would result in significant removal of the surfactant remaining on the crosslinked fibers, for example, washing or blanching and washing steps. Referring now to the embodiment of a disposable absorbent article comprising a liquid pervious top sheet, a liquid impervious backsheet and an absorbent core positioned between said top sheet and said backsheet, said absorbent core comprising (i) the member of acquisition and distribution of fluids of the present with the upper surface adjacent said upper sheet and a lower surface and (ii) a fluid storage member having an upper surface in contact with the lower surface of the fluid acquisition and distribution member and comprising discrete particles of absorbent gelling material. A preferred embodiment in the form of a disposable, medium-sized diaper for a male baby is described in conjunction with Figure 1. With reference to Figure 1, a disposable diaper 10 has a fluid-permeable upper sheet 12 (which is partially cut-away to show the interior elements), and a liquid-impermeable backsheet 14 with an absorbent core positioned therebetween consisting of an acquisition member and fluid distribution 16 and a fluid storage member 18. The fluid acquisition and distribution member 16 is rectangular in top view. The fluid storage member 18 is in the hourglass form in top view. The fluid acquisition and distribution member 16 is placed on the upper part of the fluid storage member 18 with its longitudinal centerline positioned along the longitudinal centerline of the fluid-storing member and closer to the front waist than to the back waist. The fluid acquisition and distribution member 16 is 7.62 cm by 25.40 cm by approximately 0.635 cm and has its edge closest to the front waist positioned approximately 5.08 to 7.62 cm behind the front waist. The fluid storage member 18 is symmetrically positioned between the upper sheet 12 and the rear sheet 14 and is 12.7 cm wide in the crotch region and 26.67 cm wide at its lateral edges and has its lateral edges spaced downward approximately to 2.54 cm from the front and back waist (the lateral edges of the top sheet and back sheet). In this embodiment, the upper surface area of the fluid acquisition and distribution member 16 is approximately one third that of the upper surface area of the fluid storage member 18. This is only one example of an embodiment of the disposable absorbent article. for which the present invention finds application. In general, the fluid acquisition and distribution member must encompass the vicinity of the discharge area of the body fluids. For disposable diapers, these areas would include the crotch area and preferably for men, also the region where the urine discharges occur at the front of the diaper (ie, the part of the diaper that is intended to be placed on the front of the wearer). . As indicated above, the fluid acquisition and distribution member preferably has a top surface with an area that is smaller than the top surface area of the fluid storage member, most preferably having a top surface with an area that is from about 15% to 95% of the upper surface of the fluid-storage member, most preferably having a superior surface with an area that is from about 20% to 50% of the upper surface of the fluid-storage member. The fluid acquisition and distribution member may be in any desired manner consistent with the functional adjustment and goals discussed above. These shapes include, for example, circular, rectangular, trapezoidal or oblong, for example in the form of watch glass, in the form of dog bone, in the form of half bone, oval or irregularly shaped. The fluid storage member can be in any desired form consistent with the functional adjustment, including those forms described above for the fluid acquisition and distribution member. Although Figure 1 describes a diaper where the fluid acquisition and distribution member and the fluid storage member have different shapes, these may also have the same or similar shapes. The backsheet of the articles herein can be constructed, for example, of a thin, plastic film of polyethylene, polypropylene or other moisture-impermeable material, flexible, that is s, usually impermeable. Polyethylene, which has an enhanced caliper of approximately 1.5 mils, is especially preferred. The top sheet of the articles of this, may be made partly or completely of synthetic fibers or films comprising said materials such as polyester, polyolefin, rayon, or the like, or natural fibers such as cotton. In upper non-woven sheets, the fibers are typically joined together by a thermal bonding process or by a polymeric linker such as polyacrylate. This sheet is substantially porous and allows the fluid to pass easily therethrough to the underlying absorbent core of the article. Another suitable type of top sheet comprises the top sheets formed of liquid impervious polymeric material such as polyolefins. Said upper sheets may have tapered capillaries of a certain diameter and tapered in the upper sheet to allow the flow of the discharged fluids through the upper sheet towards the underlying absorbent core of the article. The construction of the topsheet in Davidson, U.S. Patent is generally described. No. 2,905,117, issued September 22, 1959; Del Guercio, Patent of E.U.A. No. 3,063,452, issued November 13, 1962; Holliday, Patent E.U.A. No. 3,113,570, issued December 10, 1963, and Thompson, Patent E.U.A. No. 3,929,135, issued December 30, 1975, the patents of which are incorporated herein by reference. The top sheets are constructed from polyester, rayon, rayon / polyester blends, polyethylene or polypropylene. The top sheet can be treated with surfactants to make it more wettable and therefore less hydrophobic, thereby increasing the flow of fluids through this at least to the initial wetting. However, the top sheet must be even more hydrophobic than the absorbent article element that receives the fluids after passing through the top sheet. The fluid acquisition and distribution member is described in detail above. Preferably, it is completely composed of individualized, crosslinked, cellulosic fibers having a crosslinking agent of C2-C9 polycarboxylic acid reacted therein in an interfiber ester crosslinking form that provides a water retention value of about 25 to 60 and having uniformly distributed over this from about 0.0005% to 1%, most preferably from 0.001% to 0.2% by weight, on a dry fiber basis, of active surface active agent. It may contain amounts of other materials that substantially do not remove their ability to acquire fluids and release such an adjacent storage member. Therefore, de - c? i. -preference, is free of absorbent gelling material, ie contains no more than about 2.0% absorbent gelling material, most preferably less than about 1.0% absorbent gelling material, most preferably, zero or essentially zero (less than 0.5 %) of absorbent gelling material. The fluid acquisition and distribution member is easily prepared as follows. A bundle of fibers as described above runs through a disk refiner to fluff the material to produce individual fibers that are placed in air in a mobile foraminous web that passes into a suction drum to produce the members in the proper manner. If adjustment of the resulting body density is necessary, it is easily carried out using a hydraulic press. The fluid-storage member comprises from 15% to 100%, by weight, preferably at least 25% of absorbent gelling material, and from 0% to 85% of carrier material. The absorbent gelling material can be in the form of discrete particles or in the form of fibrous material or in any other form that can be incorporated into a flexible web or sheet to form the storage member. The superabsorbent materials for use in the storage layer are those that are capable of absorbing at least 10 grams of an aqueous solution of 1% NaCl, prepared using distilled water per gram of absorbent gelling material, determined in accordance with Test Method of Absorbent Capacity described in the US Patent 5,217,445, incorporated herein by reference. The absorbent gelling material that is employed in the storage layer of the absorbent core will very often comprise a partially neutralized, slightly crosslinked absorbent gelling material, substantially insoluble in water. This material forms a hydrogel when making contact with water. Said polymeric materials can be prepared from acid-free, unsaturated, polymerizable monomers. Suitable unsaturated acid monomers for use in the preparation of the absorbent gelling material include those listed in Brandt / Goldman / Inglin, in the E.U.A. No. 4,654,039, issued March 31, 1987, and reissued as Patent E.U.A. No. RE 32, 649 on April 19, 1988, both incorporated herein by reference. Preferred monomers include acrylic acid, methacrylic acid, and 2-acrylamido-2-methylpropanesulfonic acid. Acrylic acid by itself is especially preferred for the preparation of the polymeric gelling agent material. The polymeric component formed from unsaturated acid-containing monomers can be prepared from conventional types of monomers including hydrolyzed acrylonitrile grafted starch, polyacrylate grafted starch, polyacrylates, maleic anhydride-based copolymers and combinations of same. Especially preferred are polyacrylate grafted starch and polyacrylates. The polymeric absorbent gelling materials in general will be slightly crosslinked. The crosslinking serves to make the water-insoluble hydrogel forming gelling agents substantially water-insoluble, and the cross-linking therefore partly determines the characteristics of the gel volume and the extractable polymer of the hydrogels formed from the polymeric gelling agents employed. Suitable cross-linking agents are well known in the art and include, for example, those described in greater detail in Masuda et al., In the US Pat. No. 4,076,663, issued February 28, 1978, incorporated herein by reference. Preferred crosslinking agents are di or polyesters of monounsaturated or polycarboxylic acids with polyols, bisacrylamides and di or triarylamines. Other preferred crosslinking agents are N, N'-methylenebisacrylamide, trimethylolpropane triacrylate and rialylamine. The crosslinking agent can generally be from about 0.001 mol% to 3 mol% of the particles of the hydrogel forming hydrogel polymer material. The absorbent, polymeric gelling materials are generally used in partially neutralized form. For use herein, said partially neutralized materials are considered when at least 25 mol%, and preferably at least 50 mol% of the monomers used to form the polymer are monomers containing acid groups that have been neutralized with a cation salt former Suitable salt-forming cations include alkali metal, ammonium, substituted ammonium and amines. This percentage of the total monomers used which are monomors containing neutralized acid groups is referred to as the "degree of neutralization." When the absorbent gelling material is used in the form of discrete particles of absorbent gelling material, it is used in conjunction with the non-superabsorbent carrier material, for example, fibrous carrier material, including cellulose fibers, in the form of a sponge, such as it is conventionally used in absorbent cores. Modified cellulose fibers can also be used, but are not preferably used. Synthetic fibers can be used and include those made of cellulose acetate, polyvinyl fluoride, non-soluble polyvinyl alcohol, polyethylene, polypropylene, polyamides (such as nylon), polyesters, two-component fibers, three-component fibers, mixtures thereof and similar. Preferred synthetic fibers have a denier of about 3 denier per filament to about 25 denier per filament, more preferably from about one denier of 5 per filament to about one denier of 16 per filament. Also preferably, the surfaces of the fiber are hydrophilic or are treated to be hydrophilic. The average dry density of the fluid-storage member comprising discrete particles of absorbent gelling material and a carrier material that will generally be in the range of about 0.06 to about 0.5 g / cm3, and more preferably within the range of about 0.10 to approximately 0.4 gr / cm3, but more preferably from about 0.15 to about 0.3 gr / cm3, most preferably from about 0.15 to about 0.25 gr / cm3. Typically the basis weight of the fluid-storage member can vary from about 0.02 to 0.12 g / cm2, more preferably from about 0.04 to 0.08 g / cm2, most preferably from about 0.05 to 0.07 g / cm2. This type of fluid-storage member can be substantially homogeneous (i.e., having the same density and basis weight throughout, and having the absorbent gelling material uniformly distributed therethrough) or containing regions of density and relatively higher and relatively lower basis weights or may have a gradient of absorbent gelling material with more absorbent gelling material in regions of high fluid handling requirements and less absorbent gelling material in regions of lower demands. The embodiments of the fluid-storage member comprising fibrous carrier means can be formed by a process comprising placing in air a substantially dry mixture of fibers and particles of absorbent gelling material and, if desired or needed, densifying the resulting screen. Said process is, in general, more fully described in the aforementioned US Patent E.U.A. 4,610,678, Weisman and Goldman, issued September 9, 1986, incorporated herein by reference. These embodiments of fluid storage members can also be formed by measuring the absorbent gelling material from a lint hopper (e.g., obtained by refining a dry batan cloth disc) on a conveyor belt and moving the belt. adjacent to a suction drum containing bags to suck the mixture into the bags to form the mixture in the shape of the bags. Referring now to the case where the absorbent gelling material is used instead of the discrete particles of absorbent gelling material. These types of fibers are described in Textile Science and Technology, Volume 7, Prnoy K. Chatterjee, editor, Elsevier Science Publishers B.V. (Bajoe Countries), 1985, in Chapters VII and VIII (pages collectively 217-280), incorporated herein by reference. One type of absorbent gelling material fiber comprises cellulosic fibrous pulps of polycarboxylate-modified polymer such as soft, medium hydrolyzed, grafted methyl-acrylate wood kraft pulps. These superabsorbent fibers are described in the patent application E.U.A. serial number 07 / 378,154, filed July 11, 1989, entitled "Absorbent Paper Comprising Polymer-modified Fibrous Pulps and Wet-Laying Process for the Production Thereof", by Larry N. Mackey and S. Ebrahim Seyed-Rezai, Incorporated here for reference. Another type of fibers of absorbent gelling material may include crosslinked carboxymethyl cellulose and polymer grafted cellulose fibers. The polymer grafted cellulose fibers include hydrolyzed polyacrylonitrile, polyacrylic esters, and polyacrylic and polymethacrylic acids. Discussion of these fibers and references to processes for elaboration, can be found in The Chatterjee's Vol. 7 of Textile Science and Technology as previously incorporated here by reference. They are also discussed in A. H. Zahran et al., "Radiation Grafting of Acrylic and Methacrylic Acid to Cellulose Fibers to Impart High Water Sorbency", J. of Appl. Polymer Science, Vol. 25, 535-542 (1980), which discusses the radiation of enkertation of methacrylic acid and acrylic acid to cellulose fibers, as the title suggests; Patent E.U.A. No. 4,036,588, J.L. Williams et al., Issued July 19, 1977, which describes the graft copolymerization of a vinyl monomer containing a hydrophilic group in the cellulose-containing material, for example rayon threads; and the U.S. Patent. No. 3,838,077, H.W. Hoftiezer et al., Issued September 24, 1974, which describes grafted polyacrylonitrile cellulose fibers. Each of the foregoing disclosures is incorporated herein by reference. The fibers of absorbent gelling material can be incorporated into conventional or other non-superabsorbent fiber webs, such as in webs placed in humerus or in webs laid in air. These can also be formed into non-woven sheets; said sheets may consist essentially of fibers of absorbent gelling material with or without carrier material. Nonwoven sheets made from fibers of absorbent gelling material such as non-acrylated superabsorbent microfibers and fibers useful for making such sheets are available from Arco Chemical Co., (Newtown Square, Pa, USA), under the trade name FIBERSORB ® and from Japan Exlan Co., Ltd. (Osaka, Japan), which sells absorbent gelling material fibers comprising a polyacrylonitrile core with a polyacrylic acid / polyammonium acrylate coating under the trade name LANSEAL®. The fluid acquisition and distribution member is positioned in the fluid storage member by means known to those skilled in the art, for example, suction bands and suction drums. The invention is illustrated by the following examples.

REFERENCE EXAMPLE 1 Three hundred grams (on a dry bone base, that is, a moisture-free base) are dispersed from Southern softwood kraft fibers in the form of fullers' sheets, in an aqueous solution containing 551.57 grams of citric acid , 6.89 grams of Pluronic® L35, 137.89 grams of sodium hypophosphite, and 63 grams of sodium hydroxide, by immersion and mixing, to form a 2.5% consistency suspension. The fibers are soaked in the suspension for 30 minutes. The mixture is centrifuged to provide a dehydrated cake of about 44% consistency. The dehydrated cake, which contains approximately 6% by weight of citric acid (on a dry fiber basis) and 0.075% of Pluronic® L35, on a dry fiber basis, is air dried at approximately 50% consistency. The air-dried cake is sponged in a disc refiner at a speed all the way to 180 g / min, dried instantaneously to a consistency of 90% and heated for 6 minutes at an air temperature of 176.67 ° C in an air oven through and then cooled with air with a fan to less than 65.66 ° C. There is no washing or bleaching after curing.

REFERENCE EXAMPLE 2 Reference example 1 is duplicated except that Pluronic® L35 is omitted.

EXAMPLE I Reference examples 1 and 2 are duplicated on a much larger scale and packs of fibers crosslinked with citric acid are produced with surfactant on top of them and fibers crosslinked with citric acid without surfactant on them. The test results in fibers of the bales indicated for fibers crosslinked with citric acid with surfactant, a density 5K of 0.11 g / cm3, a drip capacity of 11.0 g / g, a fluid conduction velocity of 0.62 cm / s a wet compressibility of 6.9 cm3 / g, and for fibers crosslinked with citric acid without surfactant, a 5K density of 0.12 g / cm3, a drip capacity of 12.4 g / g, a fluid conduction velocity of 0.89 cm / s and a wet compressibility of 6.9 cm3 / g. In each of the cases, the water retention value is approximately 35. The fibers of each type are sponged in a disk refiner and then placed in air on a moving band, passing to a suction drum for forming the rectangular members of acquisition and distribution of fluids of 3 inches by 10 inches by approximately a quarter of an inch, in each of the cases, the density is adjusted to 0.07 g / cm3 using a hydraulic press if it is no longer at this "Level In the skin moisture test, the use of fibers with surfactant was found to result in a moisture in 4.1% of cases, considering the use of fibers without surfactant was found to result in moisture in 11.7 of the cases, it was found that the difference is statistically significant at the level of 90% reliability, the results of the test showed a sustained effect, that is, a benefit during nighttime use. the use of fibers with surfactant was found to result in runoff in 2.82% of the cases, considering the use of fibers without surfactant was found to result in runoff in 6.99% of the cases.The difference was not found to be statistically significant when at least 90% confidence level due to base size, a runoff speed of 2.82% is considered an excellent result.

".. In the acquisition speed test, the use of fibers with surfactant was found to provide an Ao acquisition potential of 10.3 and a K acquisition speed constant of 127, considering the use of fibers without surfactant. found that it provides an acquisition potential Ao of 10.2 and a constant of acquisition speed K of 117. The results are the averages of 3 to 5 repetitions in different diapers. In test of jet capacity, the fluid retained by the members in the loads is established in Table 1 below.

TABLE 1 Load Fluids retained by (ml) members in the load (a) With surfactant No surfactant 50 12.1 20.5 100 19.2 23.1 150 21.3 26.6 200 20.6 24.2 250 20.4 30.1 300 22.9 32.3 350 25.2 24.7 400 25.4 32.7 In test of jet capacity, the fluid retained by the members after 15 minutes is established in Table 2 below.

TABLE 2 Load Fluids remaining in the (ml) limb after 15 minutes With surfactant Without surfactant 50 1.0 9.4 100 4.5 17.6 150 9.5 18.9 200 11.1 20.1 250 12.4 22.3 300 14.2 30.4 350 20.4 24.2 400 19.4 32.1 The results of Tables 1 and 2 normalized by regression analysis are described in Figure 2, where the continuous line represents the results in the load, and the dotted lines represent the results after 15 minutes and the lines with Xs denote that there is no surfactant was used and lines with squares denote that surfactant was used. The results of the jet capacity test show that the member without surfactant, also initially as after 15 minutes, retains more fluid than the member with surfactant. This shows that the member with upper fluid surfactant partitions (distributes it to a higher adjacent contact storage layer) than the member without surfactant and that the effect is a sustained effect. This is consistent with the advantage of dryness (low results in the percentage of moisture) found in the skin wetting test as indicated above.

EXAMPLE II A disposable diaper was prepared comprising a thermally bonded polypropylene top sheet, a fluid impermeable polyethylene backsheet, a fluid acquisition and distribution member composed of fibers crosslinked with citric acid with Pluronic L35 thereon, under the upper sheet and hourglass-shaped fluid-storage member (comprising a mixture placed in air of soft southern pulp Kraft fluff and sodium polyacrylate polymeric absorbent material of the type described in US Pat. No. 32,649 and having an Absorbent Capacity in the Absorbent Capacity Test of approximately 30 g / g) placed between the fluid acquisition and distribution member and above the backsheet. The diaper is similar in structure to that described in figure 1. The diaper provides excellent dryness and low incidence of runoff results during nighttime use in male babies. Similar results of excellent dryness and low incidence of runoff are provided in nighttime use in female babies, where the diaper is the same as that described above, except that the fluid acquisition and distribution member is 12 inches long and symmetrically placed with respect to the fluid storage layer. Modifications will be obvious to those skilled in the art. Therefore, the invention is defined by the claims.

Claims (11)

NOVELTY OF THE INVENTION CLAIMS

1. A member for acquisition and distribution of fluids for use in a disposable absorbent article, said member having a dry density ranging from 0.03 to 0.20 g / cm3 and consisting essentially of cellulose fibers crosslinked with C2-C9 polycarboxylic acid, individualized, having an amount of crosslinking agent of C2-C9 polycarboxylic acid reacted therein in an intrafiber ester reticular bonding form which gives a water retention value of about 25 to 60, and which is distributed over it of about 0.0005% to 1%, by weight, on a dry fiber basis, of an active surface agent.

2. The fluid acquisition and distribution member for use in a disposable absorbent article, according to claim 1, further characterized in that the active surface agent is present in the fibers in an amount of up to about 0.15%, by weight, in a dry fiber base.

3. The fluid acquisition and distribution member for use in a disposable absorbent article, according to claim 1, further characterized in that the individualized crosslinked cellulose fibers with the active surface agent thereon are prepared in a process that it comprises heating the non-crosslinked cellulosic fibers with from 1% to 15% of the crosslinking agent of C2-C9 polycarboxylic acid, by weight, in a citric acid base, applied on a dry fiber base, on top of it, and of 0.005% to 1% of the active surface agent, by weight, applied on a dry fiber base, on top of it, to cause the polycarboxylic acid crosslinking agent to react with the cellulosic fibers and form ester crosslinks between the cellulose molecules , to form said cellulosic fibers crosslinked with the active surface agent on top of them, without washing or bleaching and washing the crosslinked fibers.

4. The fluid acquisition and distribution member for use in a disposable absorbent article, according to claim 3, further characterized in that the active surface agent is a nonionic surfactant.

5. The fluid acquisition and distribution member for use in a disposable absorbent article, according to claim 4, further characterized in that the nonionic surfactant is one formed by the condensation of ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol such that the surfactant has a hydrophobic poly (oxypropylene) unit and a hydrophilic poly (oxyethylene) unit.

6. The fluid acquisition and distribution member for use in a disposable absorbent article, according to claim 5, further characterized in that the nonionic surfactant has an average molecular weight ranging from about 1000 to 5000 grams / mol, the The molecular weight of the poly (oxypropylene) hydrophobic unit ranges from 900 to 2000 grams / mol, and contains from 10% to 80% hydrophilic poly (oxyethylene) unit by weight, in the total molecule.

7. The fluid acquisition and distribution member for use in a disposable absorbent article, according to claim 6, further characterized in that the nonionic surfactant has an average molecular weight of 1900 grams / mole, the molecular weight of the unit of hydrophobic poly (oxypropylene) is 950 grams / mol, and contains 50% of the hydrophilic poly (oxyethylene) unit by weight in the total molecule.

8. A disposable absorbent article comprising a liquid pervious topsheet, a liquid impervious backsheet and an absorbent core positioned between said topsheet and said backsheet, said absorbent core characterized in that it comprises: (i) an absorbent member; acquisition and distribution of fluids as defined in claim 1 with a top surface positioned adjacent said top sheet and a bottom surface; and (ii) a fluid storage member having an upper surface in contact with the lower surface of the fluid acquisition and distribution member and comprising discrete particles of absorbent gelling material. The disposable absorbent article according to claim 8, further characterized in that the upper surface area of the fluid acquisition and distribution member is smaller than the area of the upper surface of the fluid storage member. The disposable absorbent article according to claim 9, further characterized in that the top surface area of the fluid acquisition and distribution member is from about 15% to 95% of the area of the upper surface of the storage member of fluids The disposable absorbent article according to claim 10, further characterized in that the upper surface area of the fluid acquisition and distribution member is from about 20% to 50% of the area of the upper surface of the storage member of fluids EXTRACT OF DISCLOSURE Skin moisture is minimized in the overnight use of a disposable absorbent article containing an essentially essential acquisition and distribution member of crosslinked cellulosic fibers with C2-C9 polycarboxylic acid prepared in the presence of a surfactant. .