MXPA01005270A

MXPA01005270A - Superabsorbent composite sheet and method for preparing the same

Info

Publication number: MXPA01005270A
Application number: MXPA/A/2001/005270A
Authority: MX
Inventors: Suzuki Migaku; Matsumoto Ryoichi
Original assignee: Nippon Kyushutai Gijutsu Kenkyusho:Kk
Priority date: 1999-09-29
Filing date: 2001-05-25
Publication date: 2002-05-09

Abstract

Method and apparatus for transmitting data from a central communication station (104) to a mobile communication device (106) using a pre-selected data protocol if the central communication station (104) cannot initiate data communication with the mobile communication device. The central communication station (104) contacts the mobile communication device (106) in a manner other than the pre-selected data protocol, such as by placing a wireless telephone call to the mobile communication device (106). The mobile communication device (106) contains means for determining the origin of the wireless telephone call (202, 200). If the mobile communication device (106) determines that the wireless telephone call originated from the central communication station (104), data communications are initiated by the mobile communication device (106) to the central communication station (104). Data is then transmitted from the central communication station (104) to the mobile communication device (106).

Description

HIGHLY ABSORBENT WATER SHEET AND METHOD TO MANUFACTURE THE SAME Field of the Invention The present invention relates to a water-highly composite composite sheet and in particular, to a highly water-absorbent composite sheet with a highly water-absorbing solid resin held in a non-woven substrate sheet and a method for manufacturing the same. The present invention also relates to absorbent products using said highly water absorptive composite sheets. In the present invention, any form of solid substances including particles, buttons, films, or shapes similar to non-woven materials can be used as in the highly water-absorbent resin. In this description, the terms "solid water highly absorbent resin" or "solid SAP" means highly water absorbing resins of each of said forms.

BACKGROUND OF THE INVENTION Composite sheets highly absorbent of water comprising a nonwoven substrate sheet1 and a solid SAP held on the surface of the nonwoven substrate have been used as the absorbent component in such absorbent products such as baby diapers, adult diapers , sanitary napkins, blood absorbers and pads for breast milk. Said highly water absorbent composite sheets are described in several patents such as US Pat. No. 5,147,343. Heretofore, in this type of highly water absorbing composite sheets, the fixation of solid SAPs to a nonwoven substrate sheet has been done by means of the adhesiveness of a hot melt adhesive. Or a method of coating the non-woven substrate sheet with a solid SAP suspension or a suspension of a solid SAP and pulp mixture has been applied. In the case of the solid SAP and pulp mixing system, the fixation of the solid SAP to the non-woven substrate sheet depends on the self-adhesiveness of the pulp. In the case where a suspension containing solid SAP is used, a suspension can sometimes be used where easy linker fibers are added to thermally melt (eg, bicomponent fibers). This suspension is applied to the non-woven substrate sheet and heated and then cooled by means of which the solid SAP, and the pulp, if any, are fixed within the non-woven substrate sheet by means of the easy linker fibers. melt thermally Another method for fixing the solid SAP to the non-woven substrate sheet is that the easy-to-melt fibers, or the fiber coil containing said easy-to-melt fibers are made to contain solid SAP and by heat treatment The fibers constituting said fiber coil are melted together with the result that the solid SAP is fixed within the substrate. However, in conventional technology, in the case of the solid SAP and pulp mixing system in particular, it is difficult to increase the proportion of solid SAP / pulp ("SAP ratio") to a larger point and therefore the proportion maximum has been around 50% by weight. In the system where the solid SAP is fixed by means of the linkage, the swelling capacity of the solid SAP and the binding capacity of the solid SAP by means of the linker operate in an antagonistic action with each other. That is, if the bonding capacity of the solid SAP is higher, the greater swelling of the solid SAP is prevented, and conversely the swelling is prevented less, if the solid SAP bond becomes more difficult. Therefore, a main object of the present invention is to provide a structure wherein the solid SAP swells to the substrate at the same time as it swells; that is, a structure that while the solid SAP and the substrate are loosely linked with one another so that the SAP maintains its degree of freedom, the swollen solid SAP is thus contained by the substrate so that the solid SAP it does not leave the substrate.

SUMMARY OF THE INVENTION In accordance with the present invention, there is provided a highly absorbent composite sheet which comprises a substrate of nonwoven material, solid SAP and a thermally fusible component, characterized in that: said nonwoven substrate has a bulky structure; part of said solid SAP is contained within said bulky structure and the remainder is exposed on the surface of said non-woven substrate; said thermally fusible component is a hot melt adhesive; said hot melt adhesive forms a fibrous network; and said fibrous network covers said solid SAP in contact with said solid SAP by means of which said solid SAP is stopped in its position. The preferred range of the coated amount of said hot melt adhesive is 0.2 to 10 g / m2. The heat fusion adhesive is preferably of the non-tacky type; for example, an adhesive comprising as main component an ethylene copolymer and vinyl acetate is more preferable. The content of vinyl acetate in the ethylene / vinyl acetate copolymer is preferably 20 to 40% by weight and its thermal fluid coefficient is preferably 50 to 150 g / 10 min. In accordance with the present invention, there is provided a method of manufacturing a highly absorbent composite sheet which comprises the steps of: forming a bulky structure by raising a non-woven substrate; the application of a paste containing solid SAP to said elevated surface of said non-woven substrate, and subsequently removing the remaining liquid and drying it by means of which part of the solid SAP is contained in said bulky structure and the rest of said solid SAP is exposed on the surface of said non-woven substrate; and making a fibrous heat fusion adhesive by means of a curtain spray apparatus, then blowing the adhesive in the form of a curtain and forming a fibrous web on said nonwoven substrate and said solid SAP. The elevation can be done in different ways. A preferable means for raising is to make a surface of a non-woven substrate in contact with a hot roll and then to bring it into contact with a cooled roll after it has been removed from the hot roll. All solid SAP is preferably contained in the bulky structure of said non-woven substrate, for example, in the gaps between the fibers constituting the non-woven substrate. Although depending on the amount of solid SAP added and the bulkiness of the carded coil used, part of the solid SAP may be exposed on the non-woven substrate, and not find a way to achieve the object of the present invention.

However, said exposed solid SAP can be converted to dust and particles as they are worn and bent when the non-woven substrate • which contains the solid SAP is divided or is incorporated within a product even if said solid SAP appears to be stable as it remained stationary even if it is in a dry condition. And said exposed solid SAP can be easily separated from the compound when it is swollen in the wet condition. With the object of stabilizing the solid SAP in said condition • dry and wet, only by virtue of the containment capacity of the non-woven substrate, preferably, the nonwoven substrate needs to be made more bulky, and the solid SAP that is to be contained by the substrate needs to be smaller. In other words, generally speaking, the nonwoven substrate alone can hardly contain 70% more of the solid SAP • used and the aggregate amount of solid SAP can hardly be greater than 300 g / m2. Using a fibrous web based on the use of a hot melt adhesive according to the present invention, said non-woven substrate has not been used further to be debarked very frequently, for example a rubber foam (generally called "SB") or a composite of a foam / melt blown / foam rubber (generally called "SMS") can be made useful as the absorbent substrate. According to another aspect according to the • present invention, there is provided a highly absorbent composite 5 comprising an absorbent compound (M) which comprises a nonwoven substrate, an SAP layer and a layer of heat melt adhesive forming a fibrous network covering said layer of SAP, and the material of the sheet (N) placed on said adhesive layer, being bound Said composite absorbent (M) and said sheet material (N) together by said layer of hot melt adhesive with an adhesive property thereof to form a composite structure (M / N). 15 Instead of the sheet material (N), it is possible to use other composite absorbers (M ') having the same construction as the previous composite absorbers. The composite absorbers (M) are arranged in layers on the other composite absorbent (M ') in such a way that the hot melt adhesive layers are brought into contact with each other and are being bonded together by the adhesive property thereof to form a composite structure (M / M').

Alternatively, a sheet of additiomaterial (N) may be interposed between said composite absorbers (M) and (M ') and bonded thereto by any adhesive property of the heat-melt layers of the composite absorbers (M) and ( M ') to form a composite structure (M / N / M'). In another embodiment of the present invention, there is provided a highly absorbent sheet in which the solid SAP is generally distributed in almost all layers on one surface of a non-woven substrate with portions thereof in the voids of the non-woven material and another part of the same exposed outside the surface, wherein the surface of said exposed solid SAP layer is covered by a fibrous dual network structure consisting of a first fine mesh fibrous network, comprising a hot melt adhesive and a second fibrous mesh placed on said first net and of a thicker mesh compared to the first net comprising a layer of hot melt adhesive so that the highly absorbent sheet is much less capable of peeling than the conventioproduct. In the highly absorbent sheet thus covered by the dual fibrous web, the solid SAP does not necessarily need to be bonded to one another by means of fine cellulose fibers. In the aforementioned configurations, the first fibrous network is fine mesh and the second fibrous network placed on the first fibrous network is thicker mesh, but the relationship between the two can be inverted, that is, the first fibrous network can be of coarse mesh and the second fibrous network placed on the first fibrous network can be fine mesh. Preferably, the fibers of the thin-mesh heat-casting layer are thinner than those of the thicker-mesh heat-casting layer. In accordance with the present invention, there is provided a method for manufacturing a highly absorbent composite sheet by treating the surface of the highly absorbent composite sheet in which the solid SAP is distributed in layers on a non-substrate surface. fabric comprising a combination of: a first stage of the heat fusion processing step in which the heat-melt processing is performed by means of a heat-melt feed apparatus (A) which forms a first network fibrous fine mesh consisting of hot melt adhesive on the surface wherein said solid SAP is distributed; and a second step of heat melt processing in which a heat melt process is performed by means of a heat melt feed apparatus (B) which forms a second fibrous network consisting of melt adhesive mesh heat thicker than said first fibrous network. • In a preferred aspect of the present invention, said first step of the heat-melt processing step is carried out with a heat-melt adhesive coated in an amount of 0.3 g / m2 to 2 g / m2 so that a first fine-mesh fibrous network is formed and said second step of the heat-melt processing is performed with • the coating of hot melt adhesive in an amount of 1 g / m2 to 10 g / m2 so that it is formed a second fibrous web of thicker mesh than < in the case of said first step of heat melting processing. More preferably, said first step of the heat-melt processing step is brought to with a hot melt adhesive coated in an amount of 1 g / m2 to 10 g / m2 and said second stage of the heat-melt processing step is conducted with the heat-melt adhesive coated in an amount of 0.3. g / m2 at 2 g / m 2 so that a second fibrous network of finer mesh is formed than in the case of said first step of the heat-melt processing step. A preferred form of said heat melt feed apparatus according to present invention, are two apparatus units of • heat casting feed of the type of spray curtain which has the ability to form a network of a relatively fine mesh combined in series with respect to the direction of movement of said nonwoven substrate. Using the heat casting apparatus of the curtain spray type as indicated in • first stage of the heat-melting feed apparatus, can form a first fibrous network of fine mesh and using a spiral cast type heat-casting feeding apparatus as in said second stage of the heat-casting feeding apparatus a second fibrous web of thicker mesh can be formed than said first layer of heat casting.

Alternatively, using the hot melt feed apparatus of the spiral coating type, such as said first stage of the • heat-casting feeding apparatus, a first fibrous network of a coarser mesh is formed and using said heat-casting apparatus of the curtain-spray type as the second stage of said heat-feeding apparatus, it is formed a second casting layer for mesh heat finer than said first fibrous network. In addition, using the heat casting apparatus of the curtain spray type as said first stage of the heat melting feed apparatus can form a first network Fibrous fine mesh and using a line casting type heat-cast feeding apparatus as said second stage of the • Heat-casting feeding apparatus can form a second fibrous network of one more mesh thick that said first fibrous network. Alternatively, it is sometimes preferable that using a hot melt feed apparatus of the line coating type as the first stage of the cast iron feed apparatus In the case of heat, a first fibrous web of thicker mesh is formed than by using a heat casting apparatus of the curtain spray type as the second stage of the power supply apparatus. • heat casting, a second fibrous network of finer mesh is formed than said first fibrous network. A highly absorbent composite sheet according to the present invention is effectively used in absorbent products provided with an upper sheet having liquid permeability, a absorbent having liquid absorbency and liquid retention and a backsheet having liquid impermeability as an absorbent having said liquid absorbency and liquid retention.

Brief Description of the Drawings Figure 1 is a schematic plan view illustrating a highly absorbent composite sheet • incorporated to the present invention; Figure 2 is a sectional view taken along line A-A 'of Figure 1; Figure 3 is a schematic side view of an apparatus, which can be used to elevate the fiber coil according to the present invention; Figure 4 is a photomicrograph of SAP particles and part of an MFC coating film in contact with SAP particles (x240); Figure 5 is a flow chart showing an example of an apparatus for manufacturing a highly absorbent composite sheet according to a method of the present invention; Figure 6 is a sectional view schematically illustrating a curtain spray apparatus which can be applied to the apparatus of Figure 5, - Figure 7a is a photomicrograph of the surface of an untreated sheet by surface treatment by means of the hot melt adhesive (x30); Figure 7b is a photomicrograph of the surface of a sheet treated by the surface treatment by means of the hot melt adhesive (x30); Figure 8A-1 is a photomicrograph showing the condition of a fibrous web formed on the surface of a film in the case of a coated amount of heat melting adhesive of 1 g / m2 (x30); Figure 8A-2 is a photomicrograph showing the condition of a fibrous network formed under the same conditions as in Figure 8A-1 on the surface of a sample made by providing a solid SAP layer on a non-woven substrate (x30); Figure 8B-1, is a photomicrograph showing the condition of a fibrous network formed on the surface of a film in the case of a coated amount of heat melting adhesive of 2 g / m2 (x30); Figure 8B-2 is a photomicrograph showing the condition of a fibrous network formed under the same conditions as Figure 8B-1 on the surface of a sample made by providing a solid SAP layer on a non-woven substrate (x30); Figure 8C-1 is a photomicrograph showing the condition of a fibrous network formed on the film surface in the case of a coated amount of heat melting adhesive of 5 g / m2 (x30); Figure 8C-2 is a photomicrograph showing the condition of a fibrous network formed under the same conditions as Figure 8C-1 on the surface of a sample made by providing a solid SAP layer on a non-woven substrate (x30); Figure 9a is a sectional view showing a model of the manner in which SAP particles are supported on a non-woven substrate as applied in the present invention; Figure 9B is a sectional view showing • another model of the manner in which SAP 5 particles are supported on a non-woven substrate as applied in the present invention; Figure 10 is a graph obtained by plotting the measurements of the relationship between the frequency (%) and the thickness (μm) of the flb fibers 10 heat melting; Figure 11 is a schematic plan view showing various combinations of the layers of the first stage and the second stage of heat melting and the condition in which a sheet is covered highly absorbent by said combinations; Figure 12a is an elevation view showing a test machine for evaluating the • stability of SAP particles; Figure 12b is a side view showing the test machine illustrated in Figure 12a; Figure 12c is a plan view illustrating samples that were tested by the test machine shown in Figure 12a; Figure 12d is an oblique perspective view of the samples shown in Figure 12c; Figure 13 is a graph that illustrates the relationship between the operation time of a sample and the number of samples as they exit; Figure 14a is a plan view of a unit for the evaluation of a compliant absorbent is assembled; Figure 14b is a sectional view of the unit for evaluation of an absorbent as illustrated in Figure la; Figure 15 is a sample graph obtained by plotting the change of SAP particles as they go against time; Figure 16 illustrates the manufacturing steps of a modification of the highly absorbent composite sheet incorporating the present invention; Figure 17 shows the manufacturing steps of a further modification of the highly absorbent composite sheet incorporating the present invention; and Figure 18 shows the manufacturing steps of a further modification of the highly absorbent composite sheet incorporating the present invention.

Detailed Description of the Invention A highly absorbent composite sheet according to the present invention is described, with reference to the accompanying drawings. Figure 1 is a plan view illustrating a highly absorbent composite sheet incorporated in the present invention, and Figure 2 provides a section taken along line AA 'of Figure 1. In each of the figures, the number of reference 1 indicates the non-woven substrate, 2 indicates • the solid SAP and 3 indicates the fibrous network constituted by the thermally meltable component (hot melt adhesive). As can be clearly seen in figure 2, in the illustrated highly absorbent composite sheet, the surface of the non-woven substrate 1 is covered with the solid SAP layer in the main parts, • but the remaining parts of the surface are in contact with the fibrous network 3 and are linked to the same. In other words, the highly absorbent composite sheet comprises the first zones where the solid SAP 2 makes contact with the fibrous network 3, and the second zones where the non-woven substrate 1 contacts the fibrous network 3 directly. The first zones constitute a distribution area and the second zones constitute an acquisition area. The nonwoven substrate 1 as used in a highly absorbent composite sheet according to the present invention is preferably a nonwoven material comprising natural fiber, chemical or synthetic fiber; wood pulp, foam material or the like and bulky and high in terms of hollow so that it is outstanding in the dispersion of liquids. As said non-woven material is a coil • made bulky by means of a publicly known method such as a carded coil, needle punched, lace punched and coil bent, can be applied. Among these coils the most Preferred is a non-woven material as obtained by means of the elevated fiber coil, and said coil has a large bulky structure.

• Specifically, said nonwoven material as it is relatively light and bulky by addition (by For example, the weight is from 10 g / m2 to 100 g / m2 and the apparent specific gravity is less than 0.2 g / m2) is preferred. Figure 3 illustrates an example of an apparatus for the manufacture of a nonwoven material having a The bulky structure is raised uniformly by the lifting treatment of a fiber coil. In figure 3, a fiber coil 4 which is going to be • used as a starting material, it is previously heated in a preheater 5 as necessary (preheating zone). Then, the fiber coil 4 is heated to a temperature at which the fibers constituting it are softened, so that they are pressurized on the surface of a hot roller 6 while rotating as they are driven in a direction shown by the arrow in Figure 3 and while they are in motion as seen together with the surface, they are heated (heating and pressurization zone). The The heated and pressurized fiber coil 4 makes it come into contact with the surface of an extinguishing roller 7 which rotates in the reverse direction to the direction of the hot roll 6 so that the coil 4 is peeled off and the surface of the coil heating 6 (peeling zone). The fiber coil 4 is then extinguished as it moves along with the surface of the quenching roller 7. The fiber coil 4 while being pressurized in a medium melt condition on the surface of The heating of the heating roller 6 is extinguished and debarked as it is being brought into contact with the roller 7 by means of which the surface of the fiber coil 4 adjacent to the • surface of extinguishing roller 7 is raised. The fiber coil 4 which has passed over the quenching roller 7 is guided out of the system by means of the grid rollers 8., 8 '. Then, the solid SAP is described below. As SAP, carboxymethyl cellulose, polyacrylic acid and its salts, crosslinked acrylate polymers, starch-acrylic acid and grafted components, hydrolytes, starch-acrylonitrile graft copolymer, cross-linked polyoxyethylene, crosslinked carboxymethyl cellulose can be obtained. , composed of type of polysulfonic acid, polyethylene oxides, polymers made by the partial cross-linking of polymers that swell in water such as amide • polyacrylic and polymeric resins that have a capacity to form a hydrated gel such as copolymers of isobutylene and maleic acid. By drying any of these resins, a polymer resin can be obtained as the base material. Then, a subsequent treatment is applied in order to increase the density of cross-linking of the surface of one of these particulate resins, and at the same time an anti-blocking agent is added in order to inhibit the propensity to block the powder because it is absorbing moisture. In addition, a highly absorbent polymeric resin derived from microorganisms of an incubation product originating from Allo genes or the crosslinked amino acid, or crosslinked amino acid polymer of biodegradable asparagine acid can be achieved as SAP for the present invention. The preferred SAP forms are particles, granules, films, fibers, or non-woven material. In particular, particles, granules, flakes, buttons, fibers (whose lengths are 10 mm or shorter) and short fibers, which can be uniformly dispersed in a dispersion medium, are more preferred. In this description the term "SAP particle" is used for the purpose of convenience with the meaning and includes an SAP in a variety of ways. In addition, the size of the SAP particles is indicated by the diameter in the case of a sphere and by the length of the longest portion in the case of any other shape. In the present invention, the preferred size range of the SAP is 100 to 1000 μm.

Preferably, the SAP particles are in all cases contained in the bulky structure of said non-woven substrate, for example in the lacings formed between the fibers constituting it. Depending on the amount of resin added and the bulk of the fiber coil, however, some of the SAP can be exposed without problem outside the surface of the nonwoven substrate; this is because any of said exposed resin remains bonded through hydrogen bonds of the fine cellulose fibers when it is in its dry condition. Said exposed resin, however, can be converted to powder when the non-woven substrate is worn or folded as it is processed and, when wet part of the resin could leave the substrate, the amount of resin that is contained in the nonwoven substrate needs to be maintained at 50% by weight or more and preferably at 70% by weight or more. From this point of view, it could be said that at a higher concentration of resin contained in the desired substrate, a more bulky nonwoven substrate should therefore be used. In addition, in recent years, such polymer resins have been given importance because they are high in terms of gel stability. For example, so-called dry polymer resins are preferred. Therefore, the evaluation of the SAP has been discussed a lot in terms of such measurements as the absorption under load (AUL), and performance under load (PUL) and permeability to the liquid of the gel • Inflated (SFC). (US Patent Number 5 5,599,335 granted to Goldman and associates). However, as SAP, as applied in the present invention, the resins are generally used polymer resins which can be obtained from a relatively low degree of crosslinking without problems, if are stable for exudates and human blood and • animals. Accordingly, said resins having 15 g / or more in terms of AUL can be used without problem. Subsequently, the fibers of fine cellulose below. They can be used as fine fibers of cellulose, first finely ground pulp of all the cellulose fibers of • different size, but preferably microfibrillated cellulose (hereinafter referred to as "MFC") that has a water retention index of at least 250% by weight which is particularly good. The fine fibers of cellulose play the functions of a dispersion stabilizer to prevent the settlement of SAP particles and coagulation of SAP particles with one another during the manufacture of a highly absorbent composite sheet according to the present invention, and at the same time, after the highly absorbent composite sheet has been fabricated from a linker 5 for the binding particles. SAP with each other and SAP particles with a non-woven substrate. The fine cellulose fibers preferably for the present invention have an average fiber length of 0.01 to 0.1 mm and an average fiber diameter of O.lμm. the MFC of microfine fibers that have an apparent denier of 0.01 d or less obtained by opening the wood pulp by means of high shear forces, and the advanced version of said MFC, for example, super microfibrillated cellulose ("S-MFC"), obtained by the additional opening of said MFC, the bacterial cellulose obtained as ^ fc microorganisms in the form of raw material ("BC"), and said fine cellulose fibers that are obtained by segregating the opening of any of these fibers as they are diluted. Any of these fine fibers are fibers of a very small size and possess a water retention advantage at a high level since they contain water. A preferred example of said type of fine fibers for the present invention, has a water retention range of at least 250% by weight measured by the Tappi test method. Said type of fiber is described in detail in the Japanese Patent Layer Applications "Hei 08" (Laid! Open Hei 08) 284090 and Hei 11-17014. An example of the binding of MFC to the SAP particles in the present invention is described below: Water and ethanol are added to 2.15% by weight water dispersion of S-MFC (manufactured by Tokushu Paper Mfg. Co., Ltd under the trademark "Super Microfibrill Cellulose ") so that the dispersion of • water / ethanol (water / ethanol = 60 40 / parts) with the MFC concentration of 0.8% by weight. Note that the water retention rate of the MFC used was 320% by weight. 15 This dispersion of SAP (manufactured by Mitsubishi Chemical Co., Ltd under the trademark of Aqua Pearl US-40) was added to prepare a paste of • two components of 30% by weight of SAP and 0.6% by weight of MFC. Subsequently said paste was applied on the surface of a nonwoven substrate, which has a relatively voluminous structure by means of a coater so that the amount of said coated paste was 150 g / m2, and then immediately After the suction and removal of the remaining liquid, the substrate with the applied paste was pressed with heat for several minutes by means of a heating roller heated to a temperature of 180 ° C, and also dried with hot air so that the compound in which the SAP particles were contained within the bulky structure of the non-woven substrate was obtained. Figure 4 is a photomicrograph of a typical example that evidently shows the condition of the MFC being in contact with the surface of said particles covering the particles well. As illustrated in Figure 4, in the compound that was obtained in the manner described above, the MFC was made by covering in contact with the surface of SAP particles as it is in the partially film-like form. The thermally fusible component used for the present invention will then be described: In the present invention, a fibrous network of a thermally fusible component is formed. The coverage effect of the fibrous network is shown below: Firstly, by covering the SAP particles with the fibrous network, the SAP particles are stably maintained additionally on the non-woven substrate of the compound and therefore it is prevented from Peel and come out of the compound. For example, the SAP particles are prevented from peeling off of the compound when the particles are dry during the compound manufacturing process, are divided, assimilated or assembled within the absorbent product. In addition, when the SAP particles are wet and swollen, the fibrous web serves to maintain the holding capacity of the nonwoven substrate even in the event that the swollen SAP particles and the nonwoven substrate swell and as a result the SAP particles are prevented. that they peel and get out of the compound. In addition, when the composite is wound on a roll or stored as it is on the roll the fibrous web serves to prevent any blockage on the surface of the absorbent layer (SAP layer) of the composite and the back side of the nonwoven substrate which is adjacent to the absorbent layer in contact with one another. A thermally fusible component according to the invention is a hot melt adhesive. As described above, the thermally fusible component is a thin, thin film, fiber, and preferably a finely fibrillated form and covers the surface of SAP particles. These preferred forms of the thermally fusible component are called "fibrous". In the present invention, in order to improve the property of (formation of sticky threads, referred to hereinafter as "string-forming property") and the extensibility of the hot-melt adhesive, an elastomeric component such as an ethylene-vinyl acetate copolymer (EVA), styrene-isobutylene-styrene (SIS) copolymer and styrene-ethylene-butadiene-styrene copolymer (SEBS) can be added. As a result of the addition, the coverage effect of the SAP particles is further improved. That is, the heat-melted fibrous adhesive is spread as it is threaded into the SAP when it is being inflated. As a result the SAP particles do not prevent swelling and said swollen SAP particles prevent them from peeling or leaving the compound. In this case, said adhesive is used as a heat-melt adhesive since it is not sticky and easy to become fibers and also fibrillates. Particularly preferable heat-melt adhesive is an ethylene-vinyl acetate copolymer as the main component. The content of vinyl acetate in an ethylene-vinyl acetate copolymer is very important for the formation of the threads that form the property and convert it into fibers, and the molecular weight of vinyl acetate • affects its discharge capacity and its conversion into 5 fibers in large part. At a higher content of vinyl acetate in an ethylene-vinyl acetate copolymer, a better result in these terms. For example, the content of vinyl acetate should be 15% by weight or greater, and preferably 20% by weight. 40% by weight. The molecular weight which is an indicator • of the discharge capacity of a liquid if it is expressed in terms of a thermal fluidity index in MFR (g / 10 min) of 200 to 400 g / 10 min for a hot melt adhesive of the copolymer type of ethylene-vinyl acetate and in the present invention the MFR is 200 g / 10 min or less and preferably 50 to 150 g / 10 min. • Specific examples of a method for manufacturing a composite sheet are described below highly absorbent according to the present invention, referring to Figure 5. The nonwoven substrate, for example the fiber coil, is taken out of a winder 9. As needed, hot air is fed by means of an air line hot 11 by means of a preheater 10 which is blown to the fiber coil as it is pulled out of the baffle to preheat the fiber coil. The fiber coil which was compressed now becomes inflamed and becomes bulky by means of this preheating (preheating zone). The preheated fiber coil is heated as it is being brought into contact with a heating roller 12 and then cooled as it comes into contact with a cooling roller 13. In the case of Figure 3 described above, the surface of the The fiber coil which is brought into contact with the heating roller 12 is raised (heating and cooling zone). The high fiber coil is sent to a coater 14 where an SAP paste is fed through the PAS 15 pulp line which is applied to the raised surface of the fiber coil. Successively, the coil liquid is sucked together with an atmosphere gas by a suction line 16 and a highly absorbent composite sheet is formed which has not yet dried (coating zone). Note that SAP paste is prepared in the manner described above.

The highly absorbent composite sheet without drying is then heated as it passes through a series of drying rolls 17-1 to 17-5 in succession and • the water and solvent vapors as they are being evaporated from the sheet are discharged from the system by means of discharge line 18 (hot air drying zone). The hot melt adhesive is fed from the hot melt line 19, is applied as it is blown on the surface of • the highly absorbent composite sheet dried in this way by the hot air which contains SAP particles by means of a curtain spray apparatus 20 by means of which a fibrous network of material is formed hot melt adhesive. The composite sheet of highly absorbent material in accordance with the cover is removed from a winder 21. In the present invention, a coating apparatus is used for the hot melt adhesive, said apparatus being preferable since it has the ability to form fine fibers with a small amount of hot melt adhesive, blowing these fibers onto the surface of the absorbent composite sheet, which contains the SAP particles of so that the surface is well covered with the resulting fibrous network. More specifically, it is preferable to use an apparatus of the non-contact type (for example of the dew type, of the spiral dew type, and of the type of melt blow.) The most preferable apparatus is that of the type of melt blow capacity, to spread the hot melt adhesive by means of hot air so that the hot melt adhesive is formed into fine streams and fibers by means of a nozzle.This type of melt blown type is also called type of A curtain spray or a type of slot spray The following is an example of the type of curtain spray 20 for the hot melt adhesive as illustrated in Figure 6. An apparatus is provided. of this type with a main entrance 22, and a main tube 22 'for the hot melt adhesive, a valve 23 for introducing the hot melt adhesive, a hot melt adhesive dispensing nozzle (not shown), a plurality of air inlets 24- 1, 24-2, conductive tubes 24-1 ', 24-2', and outlet 25 for a fiber / air mixture flow. The valve 23 for introducing the hot melt adhesive is placed on the tip of the main tube 22 'and controls the flow of the hot melt adhesive fed from the conduit tube 22'. The hot melt adhesive dispensing nozzles are positioned adjacent to the valve 23 to introduce the hot melt adhesive and form a film of the hot melt adhesive distributing and feeding the hot melt adhesive in the width direction of the conforming cover is fed from said valve 23 to introduce the hot melt adhesive. The plurality of air inlets 24-1 ', 24-2' positioned has the hot melt distribution nozzle between the function for blowing hot air, to the oriented surfaces of the hot melt adhesive film through the plurality of air inlets 24-1 ', 24-2' to be the film in a manner similar to a mist and fibers. The heat-melt adhesive thus converted into fibers is made in a curtain-like manner and is deposited in a fiber coil 4. Figure 7a is a photomicrograph showing the absorbent compound on whose surface it is not treated with the hot melt adhesive and figure 7b is a photomicrograph showing the condition of the hot melt adhesive • deposited on the absorbent composite sheet whose surface is treated with the hot melt adhesive. Several experiments were conducted to investigate the relationship between the coated amount of the hot melt adhesive and the condition of the network resulting fibrous. Figure 8A-1 shows the case of a coated amount of 1 g / m2, the case of 2 g / m2 is found in Figure 8B-1, the case of 5 g / m2 is found in Figure 8C- 1. In the case of the SAP of the surface covered with the fibrous network, the results of this condition are illustrated in Figure 8A-2 in the case of 1 g / m2, the results of the condition illustrated in Figure 8B-2 in the case of a coated surface of 2 g / m2, and the results of the condition shown in Figure 8C-2 in the case of a coated surface of 5 g / m2. As the coated amount of the hot melt adhesive is increased, the density of the resulting fibrous web becomes higher and the diameter of the fibers that make it thicker. A The quantity coated with hot-melt adhesive is usually from 0.2 to 10 g / m2, and preferably from 0.2 to 5 g / m2. in the case that the amount is less than 0.2 g / m2, the constituent fibers that exist in the network are separated and conversely, if the amount is greater than 10 g / m2, the fibers become parts as in a film . Returning to Figure 1, in a highly absorbent composite sheet according to the present invention, not only the SAP particles cover the surface of a nonwoven substrate very well, but also a plurality of covered portions and a plurality of non-woven portions. Covers are mixed. The fibrous network prepared with the heat melt adhesive converted into fibrous covers of both exposed portions of the surface and SAP composite particle forming portions and on the nonwoven substrate. In general, the bond strength of a heat-melt adhesive substrate is higher than that of the SAP particles to the heat-melt adhesive. As a result, as the SAP particles swell when wetted, the heat melt fibers also extend, but an anchor portion is formed by bonding a substrate to the heat melt adhesive which serves to hold the SAP particles stably. , that is, when the SAP particles become swollen, the heat-melt fibers sustain the SAP particles of • way that SAP particles can move up to a certain point. However, in this case, the affinity of the hot melt adhesive to the nonwoven substrate becomes an important element. That is, as the affinity of the hot melt adhesive to the nonwoven substrate becomes higher, The retention of the SAP particles varies. If • that the heat-melt adhesive is an ethylene-vinyl acetate copolymer, the substrates are preferably polyethylene terephthalate (PET), polyethylene (PE) / terephthalate polyethylene (PET) and viscose rayon. Next, another embodiment of the present invention is described: In this embodiment, a highly absorbent composite sheet according to the present invention is forms in a composite by combining a surface of a nonwoven substrate with a solid SAP layer as described above, and there are two models of such a structure.

Figure 9 shows examples of said support models of the SAP particles in a non-woven substrate as applied to the present invention. < Model No. 1 > Model No. 1 illustrated in Figure 9 is a condition where most of the SAP particles exist as if they were contained in the voids formed by the fibers of a non-fibrous material with a part of the fibers constituting the fibrous layer of the substrate. non-fibrous surface and a part of the SAP particles also exposed. In the case of said bulky nonwoven substrate, 50% or more of the SAP particles are generally contained between the fibers. <; Model No. 2 > On the other hand, in Model No. 2 illustrated in Figure 9b most of the SAP particles are exposed on the surface of the non-woven material, and the layers of SAP particles and parts of the non-woven material without contained SAP particles coexist. A nonwoven substrate of this type is relatively flat, and the amount of SAP particles contained between the fibers of the nonwoven material is generally less than 50% by weight.

Models Nos. 1 and 2 are different from one another in terms of the condition of the heat melting material as it has been converted into existing fibers. That is, in Model No. 1, the heat-melted material converted into fibers is stably bonded with those existing on the surface of the fibers that make up the fiber layer of the non-woven substrate as the heat-melt material covers the SAP particles. On the other hand, in Model No. 2, the heat-melt material converted into fibers covers the exposed SAP particles and at the same time stably bound to the portion of the non-woven substrate which has no SAP particles and therefore, The stability of the cover condition is affected by the bonding of the heat casting layer and the nonwoven substrate. The present invention can be applied to the structures shown of both models. In any structure, the surface of the non-woven substrate containing the SAP particles is covered by a dual fibrous network of heat-casting layer consisting of a first heat-casting layer of a fine mesh fibrous network and a second layer of cast iron by heat of fibrous mesh network thicker than the first hot melt layer more effectively than in the case of a single layer of heat melting. Next, various conditions of the heat-melting layers applied to the present invention are explained: F About the fineness of the mesh size of the heat-casting layer of the fibrous network. In the present invention, the term "fibrous network" is used to denote a network in which the heat-melt layers are constituted by many fibers woven together with one another in a different way to the conventional heat-melt treatment, wherein The heat casting layer works to cover a film-like shape. Said fibrous network means a uniform coverage, which does not prevent the permeation of liquids and the swelling of the SAP particles. The preferred degree of fineness of the fibrous network depends on the size of the SAP particles used and the condition of said particles in existence. That is, the preferred degree of fineness is determined by the types of SAP particles used and the condition of the SAP particles. For example, if they are dry or wet. The diameter of the SAP particles when they are dry is small in the case of spherical SAP particles manufactured by the reverse phase suspension polymerization and the SAP particulate • obtained by the ground gel and specifically from about 50 μm to 300 μm in general. The particle diameter of the SAP particles in flakes1 or in the form of buttons is 300 μm to lOOOμm. SAP particles in this range of diameters expand approximately three times in diameter if they are swollen by absorbing urine. Accordingly, the diameter of the spherical SAP particles is from l ??μm to lOOOμm and that of the flake-like or button-shaped particles is from lOOOμm to 3000μm. In order to achieve the stability of the surface of the SAP particles, for example to prevent small diameter SAP particles on the surface from becoming peeled or coming off due to wear or bending of a highly absorbent composite sheet, it is more effective to have a thin-fiber fibrous web structure of fine fibers instead of having a high strength of the fibers of the heat-casting layer. On the other hand, in order to prevent swollen SAP particles from peeling or leaving when wet, It is more important to have thick fibers, for example a high fiber strength even if the fibrous network is coarse mesh. It is not easy to achieve mutually contradictory requirements through a one-time heat smelting treatment. In the present invention, combining an apparatus for feeding the heat casting to make fine fine mesh fibers, (A) and an apparatus for feeding heat melting to make thick coarse fibers (B), the contradictory requirements mentioned above are met by means of which the surface can be treated with SAP particles that are peeled or Leave less if they are dry or wet. Whether the fibers constituting a fibrous heat-melting network are thick or not or whether the mesh structure of the fibrous heat-melting network is coarse or not determined by the diameter of a nozzle to feed the melting material by heat, the frequency of feeding and the amount of material fed. If the diameter of the nozzle and the feeding interval are the same, this is determined by the amount of material fed and the amount of air charged. In an apparatus for forming (hereinafter referred to as "A") a fibrous web of fine mesh and fine fibers, the amount covered is 0.3 / m2 to 2 g / m2, and preferably from about 0. 5 g / m2 to 1 g / m2. If the amount is less than 0.3 g / m2, the coating can not be uniform and if it exceeds 2 g / m2, a thick grid is likely to result. On the other hand, in an apparatus for the formation of a fibrous network of coarse mesh and coarse fibers (hereinafter referred to as "B"), the coated amount is 1 / m2 to 10 g / m2, and preferably 1 g / m2 to 5 g / m2. if the amount exceeds 10 g / m2, and preferably from 1 g / m2 to 5 g / m2. If the amount exceeds 10 g / m2, the heat-melting material absorbs too much so that the swelling of the SAP particles can be prevented. Figure 10 is a graph obtained by plotting the measurements of the ratio between the coated amount of the hot melt material and the average denier of the resulting hot melt fibers when the same casting material was added in the same condition by heat. In Fig. 10, the frequency in% of the abscissa means the frequency of fibers that exist in a unit of length which is approximately proportional to the coated amount of the hot melt material. At the coordinate, the average diameter of the hot melt fibers, for each coated quantity is illustrated in μm. It is known from the measurements that as the coated amount of the heat melt material absorbs more, the thickness of the resulting heat melt fibers becomes larger.

The term "fine fibrous network" used in the present invention means a fibrous network consisting of fibers whose diameter is from about 3 μm to 10 μm amplified by a microscope and measured, and the term "thick fibrous network" used herein invention, means a fibrous network consisting of fibers whose diameter from about 10 μm to 50 μm. However, the fibers in a fibrous web are not like the foam of synthetic fibers, and as such they do not have a uniform diameter and a distribution across the diameter. Therefore, the aforementioned values are only averages. © Roles of the first stage and the second stage of surface treatments by heat melting. The effects have already been described when we refer to treatment of the surface of cast iron or heat by combining the feeding apparatus of cast iron by heat (A) and (B). Surface treatment by heat melting of this type can be done in three or more multiple stages so that • can achieve even better results. From point 5 of view of economic efficiency, however, the two-stage treatment is sufficient in many cases. In the combination of heat-melting feeding apparatus (A) and (B), if it is intended to in the treatment of the first stage a fibrous network of fine maya, or a fibrous network of coarse maya, with the object of a combined fineness or thickness, depends on the conditions of the non-woven substrate and the aspects of heat melting . The order for Making the fine and coarse fibers in a fibrous network should be selected in an appropriate manner taking into consideration several conditions. (D Used heat melting materials.) The requirements of a casting material for The heat used is firstly that the material can be converted into a fibrous network as easily as possible, and secondly that it is free from sticking problems and thirdly that the material can be bonded to the non-woven substrate and its components that constitute it in the easiest way possible. Because the ease of making a network • fibrous depends on such factors as the degree of polymerization and the rate of melting of the polymer used, it is very important the selection of appropriate polymers. The problem of bonding is an inherent problem in the treatment of this type, and imply a problem of bonding, when a The plurality of highly absorbent composite sheets are bent, said sheets because they are adjacent to one another are bonded to the back of the constituent nonwoven substrate, for example, the effect called blocking takes place. By Therefore, it is preferable that heat-melting materials having less bonding properties are selected. In the combination of the first and second stage treatments, a heat-melting material is desired for the treatment of the second stage which has less gluing properties, but which is a heat-melting material for the treatment of the first stage may be less strict, in terms of bonding properties because the surface of the material is covered by the heat-casting layer of the first stage. The materials of heat casting • Representatives that have less gluing problems 5 are of the E.V.A. type, for example with ethylene-vinyl acetate polymers. The content of vinyl acetate is very important in terms of the ratio of string formation and conversion into fibers. In addition, the molecular weight of acetate vinyl affects the amount of discharge and the formation of the fibers in a fairly important way. If the amount of vinyl acetate is higher in an ethylene-vinyl acetate copolymer, better performance will result as a result. For example, The amount of vinyl acetate is 15% by weight and preferably 20% to 40% by weight. The molecular weight expressed in terms of the coefficient of thermal fluidity (MFR in g / 10 min.), Indicates the liquid discharge capacity which is 200 to 400 g / 10 min., In a heat-melt material of a conventional ethylene-vinyl acetate copolymer. In the present invention, the molecular weight is 200 g / 10 min, or less and preferably 50 to 150 g / 10 min.

Such heat-melting materials are acceptable even if they have a tendency to stick, for example olefins in the forge of amorphous polyethylene and propylene and rubber components such as S.E. B.S. (copolymer of styrene, ethylene, and block copolymer of butadiene-styrene), Sil.S., (styrene block copolymer, isobutylene, styrene which can also be added) Affinity of the non-woven substrate with the heat-casting layer In the present invention, the objects of the treatment of the surface of a highly absorbent composite sheet , or of a non-woven substrate with a dual layer of heat casting, it is first to uniformly cover the surface of a highly absorbent composite sheet, with a fibrous heat-melting layer and secondly, to bond the casting layer well by color coated to the surface of a nonwoven substrate or to the fibers constituting the non-woven material In order to achieve the first object, as mentioned above, a dual network structure consisting of fine maya and coarse maya To achieve the second object, it is important to realize a good affinity of the heat melting layer to the non-woven substrate, or to the fibers constituting the substrate. To obtain an ideal bond, it is better to have identical components of the heat-melting material and a non-woven substrate. For example, a polypropylene heat melt material is used in a nonwoven polypropylene substrate with good results. However, as it is generally the case that the component of a heat melting material is different from the fiber component, it is desirable to select a compatible combination. For example, if the heat-melting material of type E.V.A. it is used, it will be able to adhere well to polyester fibers and nylon filaments. If such heat-melt material is used to bond the polypropylene fibers, a relatively strong bond can be achieved. But, when linking polyethylene and cellulose fibers, the result tends to be rather weak unless compressed sufficiently. In such a case, it is desirable to take a step to stabilize the bond by mixing the polyester fiber with the polyethylene fiber or cellulose. Following are examples of the patterns to combine the heat casting layers: In Examples 1, 2 and 3 respectively of Figure 11, several cases of combination of the first and second heat-melting stage layers and the resulting condition are shown. Case 1 is an example where a curtain spray was applied for the first and second stages, and in the heat-melting fines of the first stage they were densely combined and in the second stage, the coarse fibers of Heat castings were combined loose for surface treatment. Case 2 is an example where the fine and dense curtain spray in the first stage is combined with the coarse and loose spiral coating in the second stage. Case 3 is an example where a first stage of reinforcing line of heat melting fibers is formed by a line coating and a fine and dense curtain spray is combined in the second stage. In order to objectively ensure the degree of SAP particles, which are being stably supported without peeling or leaving under various conditions in a composite sheet of highly absorbent material whose surface has been treated in accordance with the present invention, the inventors current have prepared a stability tester as illustrated in figures 12 to 12d. Using this tester, the stability of the SAP particles contained in a non-woven substrate was measured. The values indicated as "Stability of the SAP" in the examples that will be described below in this description, are those measured by the tester. In figures 12 to 12c, reference number 26 is a motor, 27 is a mixture of a highly absorbent composite sheet to be evaluated, 28 is an operation roll, 30 is a ribbon, 31 is the surface of the sample which has been coated, 32 is its back, and 33 is a tension roller. The SAP, the non-woven material, and the surface treatment by heat melting of the absorbent composite sheet have been previously described. By applying a hot melt adhesive used for the treatment of the surface of the composite absorbent for the integral bond still with another material, an embodiment of the present invention is also important. A first modification of the modality can be used as linking means in the step of converting a composite absorbent material according to the present invention into an absorbent product1 for integrally bonding on the surface in the part where the SAP exists, another material such as toilet paper, a diffusion sheet, an acquisition layer, a top sheet or a back sheet. In such a case, any of the aforementioned materials is placed folded on the surface where the SAP exists which has been treated with a non-bondable heat-melting material, heated and compressed so as to be! achieves the integral link. Said integral link is sometimes achieved at the time when the treatment of the hot melt surface is carried out in the step of manufacturing a composite absorbent according to the present invention, in which case it is not necessary that the melting material by heat used is of the type that does not stick but can be of a type of rubber that has stuck at room temperature. Figure 16 is prepared to illustrate this first modification by integrally linking for example toilet paper (N), to an absorbent compound (M) so that the existing hot melt on the surface of (M) is used, and You can obtain a structure of (M / N). As a second modification of the present invention, the composite absorbers from which the surface has been treated with heat-melt adhesive, are integrally bonded to one another on their surfaces, where SAP and heat melting exist, so that a composite absorbent with a higher SAP content and improved performance can be obtained. That is, as illustrated in Figure 17, integrating a composite absorber such as a first layer (M) and a composite absorber as a second layer (M ') and using the existing heat melt on its surfaces through heating, adhesion and compression, a highly absorbent composite having a (M / M ') structure can be obtained. The SAP and non-woven fiber constituents of (M) and (M ') may be the same or different in terms of properties. Additionally, as illustrated in Figure 18, the structure of a resulting absorbent composite (M / N / M ') can be made having an absorbent sheet or paper (N) absorbing and integrating a first layer! of the absorbent compound (M) and a second layer of a composite absorbent (M '). 1. Preparation of sample. 1) Sizes of the samples. As a basic size, a sample was cut into dimensions of 10 cm by 80 cm. The width was made as a unit of repeating a pattern depending on the sample types. The width was approximately 10 to 30 cm. 2) Pre-drying. In order to maintain a constant water content during the evaluation, a previous drying was carried out until the water content became % by weight or less. In order to avoid deterioration of the samples, however, the drying temperature was maintained at 60 ° C or lower. 3) Preparation. The samples were allowed to remain at that temperature and humidity for at least 12 hours to make the water content 10% by weight. The coated surface of the sample was left exposed to the constant temperature and humidity of the environment or chamber. 2. Evaluation of the fixation of the particles ^ SAP by the tester. 1) The measurement of the weights of the samples (an electronic sensitivity scale of 1 mg was used. The amount of SAP coated in a sample was calculated by subtracting the weight of the substrate from the p s of a sample (W0). A sample was placed in the aforementioned tester. With the coated surface outside, the substrate surfaces of both ends of the sample were bonded by means of an adhesive tape 30 (Figure 12 d). 3) Load was applied to the sample using a tension roller. The applied load was 1 kg / 10 cm wide. 4) Start In order to collect SAP particles in the form of peeling or which they left, a sheet of black paper was placed previously below the place where the sample was operated and then the tester was started with the engine running. The speed of operation of the sample was adjusted by 30 m / min. 5) Investigation of the amount of SAP particles that leave during one minute after the operation. The number of SAP particles that leave as the number of SAP particles insufficient in the fixation (zone A) was checked during one minute of operation after the start. Figure 13 is a graph showing the relationship between the operation time and the quantity of SAP particle output. As the amount of SAP particles with insufficient fixation, the amount of SAP particles that left during one minute of operation after the start (i) was checked. ^ 10 6) Investigation of the amount of particles that leave during 4 minutes after starting again. As the amount of SAP particles that go out against time, caused by the bending wear (zone B) the amount of particles was checked SAP that left during 4 min. after restarting the operation (2). 7) Calculation of the amount of SAP particles that come out. The amount of particles that leave during a 20 minute after the start (quantity of SAP particles with insufficient fixation). The amount of SAP particles that leave during 5 minutes after the start (total amount of SAP particles that leave during 5 minutes after the start). = [(W? + W2) / W0] xlOO Next, the examples of the present invention will be described. Example 1 Preparation of the composite sheet In the procedure to be described below, a composite sheet with SAP is provided with an SAP layer to conduct a treatment • Surface with a hot melt adhesive. Preparation of bulky non-woven substrate A bovine fiber was prepared by doubling 2 g / m2 of carded fiber (layer P) of viscose rayon (1.5 x 15 42 mm), 30 g / m2 of carded bovine (Q layer) of fiber PET (6 d x 51 mm), and a sheet of paper (layer R) of 20 g / m2 pulp N in the order of layer P; layer Q and layer R • and then pecking from the side of the layer R. In this fiber bovine, the fibers are woven between the R layer and the Q layer, and the fibers of the R layer are mixed in the Q layer. The specific gravity Apparent it can be 0.07, and it remained in the form of a voluminous non-woven material. Compound manufacturing by adding SAP SAP was used in the form of chips (manufactured by Sanyo Chemical Co., Ltd., under the trademark Sun and IM-500). The SAP was uniformly added while the substrate was vibrated on a vibration plate such that the weight of the SAP on the R layer of said 200 g / m2 fiber bovine. After making the SAP particles contained by the bovine and spraying them with water so that the SAP content was 30 to 40% by weight, the bovine was compressed and stabilized to a blank sample 1. Surface treatment with cast iron heat converted into fibers. <Heat casting applicator > A curtain type coating applicator was used as illustrated in Figure 6, (manufactured by Sun Tool Co., Ltd.). The heat-melt adhesive of ethylene-vinyl acetate copolymer (hereinafter referred to as "EVA") was applied in an amount of 1 g / m 2 on the surface of said composite sheet to be treated. A composite sheet sample 2 having a structure as illustrated in Figure 7a before the heat melt treatment and a structure as illustrated in Figure 7b after the heat melt treatment. < Hot melt adhesive used > The heat-melt adhesive used was Moresco Melt S-1396 D manufactured by Matsumura Oil Co. , Ltd., whose main component was EVA.1 The properties of the hot melt adhesive were as illustrated in Figure 1 below. There was little or no problem of sticking with the hot melt adhesive. • Table 1 Component MFR Content Principal Acetate Viscosity Molded Vinyl Damping (mPa.S) 29.5-34.5 E V A% by weight 60 ± 11 85 ° C 180 ° C 11,000 15 160 ° C 22,000 140 ° C 48,000 Property evaluation • The compound obtained by the processing described above was evaluated with! he procedure described above. Table 2 below shows the stability measurements in dry condition and clamping in wet condition. From the results, it was proved that the effects of covering the material with a casting adhesive heat were very outstanding.

Table 2 SAP Stability in SAP Stability in Dry Condition Humid Condition% to% Proportion% of the output comes out of the proportion of treatment treatment absorption of part after the liquid after • 1 min. 5 min (g / g) Sample No. Example 1 Sample gain No. 1 3.1 5.7 42.0 0.0 Sample No. 2 in operation 0.19 0.25 40.5 45.0 Example 2 Sample gain No. 3 0.11 0.16 43.0 17.5 Sample gain No. 4 0.03 0.04 45.0 55.0 Sample No. 5 in operation 0.01 0.02 41.0 79.0 Sample No. 6 in operation 0 0.01 38.5 80.6 Example 2 • Preparation of a composite sheet The composite sheet with SAP provided with a layer of SAP in which the surface treatment was applied with a hot melt adhesive, was prepared with the following procedure. Preparation of the bulky non-woven substrate A non-woven dry foam lace material was • obtained by blowing a stream of high pressure water into the framework of a carded bovine of 35 g / m2 20 consisting of 50% by weight of viscose rayon fiber (1.5 dx 42 mm) and 50% by weight of PE bicomponent fiber / PET / core liner (3 dx 51 mm). I Said nonwoven lace foam material was treated by means of an apparatus provided with a heating roller and a cooling roller as illustrated in Figure 3. The non-woven material whose thickness was 2.5 mm and the apparent specific gravity of 0.03 g / cm3 was obtained in case the load was 0.1 g / m2. Compound manufacturing by adding SAP Prepared a liquid dispersion of MFC in which the concentration of MFC was 0.8% by weight! and the ethanol / water ratio was 70/30 (weight ratio), diluting 4% by weight of MFC water dispersion gel (S-MFC) (manufactured by Tokushu Paper Mfg.

Co., Ltd.) with ethanol with particulate SAP (manufactured by Mitsubishi Chemnical Co., Ltd., under the trademark "Aquapearl 211 D"). Note that the water retention of the S-CFM used was 300%. An SAP co-dispersion paste was prepared! and MFC in which the SAP content was 25% by weight, dispersing said SAP in this liquid dispersion. Said co-dispersion paste was stirred and applied on the surface of said non-woven material by means of a coater for chromatography of; Thin layer. The resulting coated sheet was dried with air, and dried with ironing after the remaining solvent was removed to obtain a blank sample of the composite sheet. The content of SAP in said compound was 200 g / m2.

Surface treatment with heat melt adhesive converted into fibers With a curtain coating applicator (manufactured by Sun Tool Co., Ltd.) as used in example 1 and a hot melt adhesive (Matsumura Oil Co., Ltd.) as also used in the applied example 1, the surface of the compound which was to be treated with SAP was covered by the hot melt adhesive at levels of 1 g / m2, 2 g / m2 , and 5 g / m2. The conditions of the heat melt adhesive converted into fibers and the resulting network are as illustrated in Figures 8 A-1, 8 B-1 and 8 C-1, respectively. Also the conditions of the SAP surface that was being covered is illustrated in Figures 8 A-2 (sample 4), 8 B-2 (sample 5) and 8 C-2 (sample 6). Evaluation of the properties This compound was evaluated as obtained by said procedure. Table 2 shows the stability of the SAP in dry condition, and the fastening of the SAP in wet condition. Samples 4, 5 and 6 were greatly improved in their dry surface stability compared to the white sample 3 and in addition, the fixation that indicated the fixation of the SAP in the wet condition was greatly improved. Example 3 Preparation of the non-woven substrate A non-woven substrate of dual structure was like that obtained by treatment with a high-pressure water jet, a 2-layer bovine of a carded bovine polyester fiber (6 dx 51 mm), as upper layer, and of a bovine carded fiber of viscose rayon (15 dx 38 mm) as the bottom layer. The upper layer was voluminous, and the lower layer was of a relatively high density and an apparent average specific gravity of 0.06 g / cm 3. Preparation of the highly absorbent sheet A liquid dispersion of water / ethanol was prepared. (the water / ethanol weight ratio was 60/40), in which the concentration of MFC was 0.67% by adding water and ethanol to an aqueous solution of 2.5% MFC (Super S-MFC microfibril cellulose) (manufactured by Tokushu Paper Mfg. Co., Ltd.).

Adding to this suspension liquid SAP SAP whose average particle size was 200 μm (manufactured by Mitsubishi Chemical Co., Ltd., under the trademark "Aquaearl AP-211D"), a paste in which the SAP content was 25% by weight. The paste was applied by means of a coater on the surface of the voluminous top layer composed of polyester fibers of said nonwoven substrate of a dual structure so that the covers of strip lines with coated portions of 7 mm in width and portions uncoated 3 mm wide were obtained and a highly absorbent sheet with an average SAP amount of 200 g / m2 was also obtained. Treatment of the surface with a layer of heat-melt adhesive The SAP-coated surface of said highly absorbent sheet was treated on the surface by adding heat-melting material of the type E.V.A. (manufactured by Matsumura Oil Co., Ltd., under the trademark "Morescomelt S-1396D") by means of a curtain spray method both in the first stage and in the second stage with a quantity of heat melting aggregate material variable. The amount of added heat melting material was 0.5 g / m2 in the first stage and 1.0 g / m2 in the second stage, combined so that three samples 1, 2 and 3 were prepared. Also, a sample was prepared comparative which was treated only in one stage with an aggregate amount of 3 g / m, in order to compare it with the other samples treated in two stages. Note that the main composition of the • heat melting material used in this example was as follows: E.V.A. 45% Wax 5% Adhesive Sponge 50% Evaluation of stability results 10 The stability in the dry condition and the stability in the absorbed condition of the 'highly absorbent sheets whose surface was treated in the first and second stages as mentioned above , were evaluated. For stability in the dry condition, the amount of SAP that was output in percent (%) was measured against time, using an apparatus shown in figures 12 to 12 d and measurements were plotted in figure 15 to indicate the change of the amount of SAP left in percentage against time. Also, the values were indicated for one minute and five minutes after the start. Stability was provided in the wet (absorbed) condition in terms of the holding range (%). The results are shown in table 3 next: Table 3 Condition of Surface Heat Smelting Treatment Evaluation of Stability Ira stage of the 2nd stage of the% percentage that goes out in treatment of condi treatment (?!? N to 1% of Retention is efstability after the Sample No. (spray curtain) (spray curtain) After 1 min After 5 min. Aphor 1 Sample No. 1 0.5 g / m2 0.5 g / m2 0 0 Sample No. 2 0.5 g / m2 1.0 g / m2 0 0.01 Sample No. 3 1.0 g / m2 1.0 g / m2 0 0.02 Comparative Sample 3.0 g / m2 - 0.05 0.10 50 In terms of stability in the dry condition, the samples that were treated in two stages obtained better results compared with the • samples that were only treated in one stage. It is shown that the sample treated with a combination of 0.5 g / m2 in the first stage and 0.5 g / m2 in the second stage was the one that obtained the best results. The sample treated only in one stage with an amount of 3 g / m2 applied, was the worst of all. This indicates that a network of said fine and dense Maya • to stop even the fine particles of SAP is much more important for the stability of the condition In this case, the dry particles of 3 g / m2 will be dried out in the case where a loose and coarse network of 3 g / m2 is provided, since in this case the SAP particles can escape. In terms of stability in the wet condition, some of the samples treated in two stages were also better in the index of subjection than those treated in a single stage even when the aggregate amount1 of the heat-melting material was lower in the previous samples and specifically, the more • treated with a g / m2 in the first stage and a g / m2 in the 5 second stage was the one that obtained the best results. This indicates that because the size of the SAP particles becomes larger as it gets wetter and swells, the thickness of the fibers that make up the fibrous network has a lot to do with the stability after the water is absorbed in the sense of • that the thick fibers are more difficult to break than the fibers that constitute a network of fine and dense structure when it is swollen. Example 4 Preparation of a non-woven substrate. A viscose cellulose nonwoven material of 40 g / m.sup.2, and an apparent specific gravity of 0.14 g / cm.sup.3, manufactured by Futamura Chemical Co. , Ltd., under the trademark "TCF 404") was used; for prepare a substrate. Preparation of a highly absorbent sheet On the surface of said substrate, an SAP paste (manufactured by Mitsubishi Chemical Co., Ltd., under the trademark "Aguapearl 211 D") was applied, a dispersion liquid was applied in which the SAP was 20% and the S-MFC was 0.6% with a weight ratio of ethanol / water of 70/30 by means of a coater in such a way that a striped line was covered with 10 mm wide coated portions, and 5 uncoated portions 5 mm wide. Therefore, a highly absorbent sheet with an SAP coated amount of 150 g / m2 was prepared. Treatment of the surface with layers of heat-melting material 10 In this example, a substrate of • viscose cellulose. As the viscose cellulose substrate bond with E.V.A. can not be said to be good, the heat-melting material (Morescomelt ME-125), in which the polypropylene (P.P.) which is relatively easy to bind with cellulose although sticky was incorporated in the first stage. In the second stage, the Morescomelt S • which contains E.V.A. as the main component was used as in example 3 above.] The main components of the Morescomelt ME-125 are the following: E.V.A. 48 parts Adhesive Sponge 40 parts P.P. 12 parts The first stage that had the objective of 'making anchor effects to improve the affinity of the stratum and to make a hot and loose heat melting treatment so that the heat-melting material was aggregated into lines of 7 mm intervals. So care was taken that the uncoated portions were added with heat-melting material. The second stage had the objective of covering the fine and dense network and the sample 4 was obtained by means of the curtain spray treatment. Evaluation of stability In order to compare the effects of the combination of the first and second stages in I the comparative samples, for example a comparative sample that had a linear treatment only in the first stage and a comparative sample that had a Drain treatment by curtains only the second stage were added. The results of the evaluation are given in Table 4 below: Table 4 Condition of Heat Smelting Treatment of the Surface Evaluation of Stability Ira stage of the 2 nd stage of the% of proportion that comes out in 1 treatment of conriipi treatment? Reoa% of retention is stability after the Sample No. (spray curtain) (dew curtain) From: after 1 min. After 5 min. absorption Sample No. 4 1 1.0 g / m2 1.0 g / m 0.01 0.02 I 90 Comparative Sample No. 1 2.0 g / m2 - 0.50 2.0 5 or less Comparative Sample 1 No 2 - 2.0 g / m 0.20 1.0 I0 or less In the case where only a linear treatment is applied, it is not surprising that due to the fact that most of the SAP particles are not covered by the layer of heat casting, the tendency of the SAP particles to leave the dry condition and the clamping of the SAP particles in wet and swollen condition, both were extremely bad. ^) 10 In the case where only the curtain spray treatment was applied, also, the tendency to get out of the SAP particles and the fastening of the SAP particles was worse than anticipated. This may be due, even in the case of a network of fine and dense maya, to which the affinity of the layer for heat melting and cellulose fiber is bad and as such the link between the two is also bad, so that an area of a part of a heat melting layer where it makes contact with the substrate as moisture is absorbed and therefore becomes swollen. On the other hand, if the heat-melting caps are combined in the first and second stages as in this example, the linear casting layer The heat in the first stage serves as an anchor and therefore the heat-casting layer is stably bonded with the heat-casting layer of the second stage so that the tendency is excellent • of the SAP particles to exit in the dry condition 5 and the clamping of the SAP particles in the wet condition and therefore the condition of swelling. Example 5 Preparation of a nonwoven substrate 10 A high nonwoven material was prepared by • the bending, as it was linked by the needle punching method and a bovine of 4 g / m2 was obtained by uniformly mixing polyester fibers! (5 dx 65 mm), and bicomponent fiber with coated core 15 (3 dx 41 mm), polyethylene and polyester fibers in a 50/50 ratio on a viscose rayon muslin material of 50 g / m2 (material similar to a network). The weight of the non-woven material was 80 g / m2, and the apparent specific gravity was 0.1 g / cm3. Therefore it was very bulky. Preparation of the highly absorbent sheet Two types of SAP particles were prepared that were contained and held in a substrate. As SAP-1, a particulate SAP cp 'n was used with an average particle diameter of 200 μm (manufactured by Mitsubishi Chemical Co., Ltd., under the trademark "Aquapearl 211D") and as SAP-2, SAP in 'shape of leaflets with an average particle diameter of 400 μm (manufactured by Sanyo Chemical Co., Ltd., low the trademark "Sunwet IM-5000"). The SAP-1 was added in an amount of 150 g / m2 as uniformly as possible to said substratum and vibrated on a vibration plate, and then the SAP-2 was added in an amount 200 g / ml as it was placed on the SAP-1 so that a highly absorbent sheet was prepared which contained and held 350 g / m2 of SAP. Most of the SAP particles were embedded in the enhanced bovine, but when the surface of the bovine that held the SAP particles turned downward, almost all SAP particles left the bovine. When the bovine was immersed in physiological salt water to assess stability in the wet and swollen condition, almost all of the SAP particles left the bovine shortly after the bovine began to swell so that the sample could not be used for measurements. Therefore, the sample was used as a comparative sample. Surface treatment with hot melt material To the SAP coated surface of said highly absorbent sheet, material E.V.A. ("Morescomelt S13960"), similar to the one used in the • Example 3 above by means of a heat-casting addition apparatus of the two-stage curtain spray type to make the sample 5. For comparison purposes, a comparative sample 4 was prepared for which the treatment of the first stage (curtain spray method) was applied only and tested in the same way as sample 5.

• Stability tests were performed identical to those performed in example 3 for sample 5 and for comparative samples 3 and 4 the results are shown in table 5 below: Table 4 • Example 6 Preparation of a nonwoven substrate A nonwoven substrate obtained by applying a high pressure water jet to a carded bovine consisting of 60% polyester fiber (3 dx 51 mm) and 40% fib was prepared. Mixed rayon rayon (1.5 dx 35 mm), used as a substrate. The apparent specific gravity of the non-woven material was 0.08 g / cm3. Preparation of the highly absorbent sheet Solution A was prepared by adding 57.3 parts by weight of 48.5% by weight of aqueous solution of sodium hydroxide, 6.4 parts by weight of water, 0.15 parts by weight of a crosslinking agent (N, N '-methylene-bis-acrylamide), and 5.0 parts by weight of 30% by weight of aqueous hydrogen peroxide solution as an oxidant to 125 parts by weight of an aqueous solution of 80% by weight acrylic acid. The monomer concentration in solution A was 60% by weight and its neutralization grav was 50% mol. Separately, solution B was prepared by adding 57.3 parts by weight of an aqueous solution of sodium hydroxide of 48.5% by weight, 9.9 parts by weight of water, 0.15 parts by weight of crosslinking agent (N, N'-methylene bis acrylamide) and 1.5 parts by weight of L-ascorbic acid as a reducing agent to 125 parts by weight of an aqueous solution of 80% by weight acrylic acid. The concentration of monomers and the degree of neutralization of solution B were the same as those of solution A.

• Two nozzles with an inner diameter of 0.13 mm each (manufactured by Ikeuchi Co., Ltd.) were used. Being the angle made by the nozzles of 30 ° and the distance between the nozzles of 4mm, said solution A and solution B were charged at a temperature of 40 ° C from one and from the other nozzle to the same speed of 5 m / sec. • Solution A and solution B were fused just after leaving the nozzles to form a liquid column of approximately 10 mm and then the liquid was caused to fall into a liquid. upward air stream in the form of droplets at a temperature of 60 ° C. These droplets were received by said non-woven substrate placed 100 cm below the tips of the nozzles, saturated with steam of 120 ° C which was blown for 10 seconds to vaporized the substrate, and was subsequently dried to a level of 10% moisture content so that a highly absorbent sheet was obtained with 220 g / m2 of sustained and contained SAP particles. Surface treatment with casting material by heat On the side of the highly absorbent sheet which held and contained the SAP particles, a hot melt material of the type E.V.A. (Morescomelt S) at 0.5 g / m2 by means of a heat-casting addition apparatus of the curtain spray type (manufactured by Sun Tool Co., Ltd.), in the first stage and then in the second stage was applied the same heat-melt material at 2 g / m2 by means of a heat-casting apparatus of the spiral coating type (manufactured by Sun Tool Co., Ltd.). The resulting highly absorbent composite sheet with resulting heat casting had a surface structure as illustrated in Figure 11, as observed by an electron microscope. The hdja did not have any dust that splashed under the dry test conditions, and showed the retention of SAP particles at 85% or higher after absorption and swelling. Example 7 Preparation of a composite absorber (M) whose surface has been treated with hot melt adhesive A viscose rayon nonwoven (1.5 d, 30 g / m2), (manufactured by Dai abo Co. , Ltd.).

• SAP was added (trademark "AP50X" manufactured by Mitsubishi Chemical Co. , Ltd.) in lines approximately 8 mm wide at approximately 3 mm intervals on the substrate by a multi-tube type SAP feeder provided with a vibrator. Cast iron adhesive was added ^ fc 10 heat (trademark "Moresco TN-288) having glued to room temperature which was fed from said curtain spray apparatus in an amount to produce a cover of 5 g / m2 of SAP in the lines, and the material resulting then it was compressed into a silicone cooling roller so that the composite absorber has a structure corresponding to M in Figure 18. The weight of the SAP • it was 150 g / m2. Preparation of composite absorber (M ') whose surface has been treated with hot melt adhesive. A material in bulky nonwoven made by needle punching at a low density of 50 g / m2 (manufactured by Toyobo Co., Ltd.) was prepared as substrate, made of hollow bicomponent polyester fiber (8 d x 51 mm) whose surface became hydrophilic. SAP was added ("AP211D" manufactured by Mitsubishi Chemical Co. , Ltd.) in lines of approximately 10 mm in width at approximately 5 mm intervals on the substrate from said multi-tube type SAP feeder. A hot-melt adhesive (Moresco TN-288) was added, which is stuck at room temperature ^ 10 is fed from said spiral type heat casting applicator in an amount to produce a cover of 10 g / m2 above the SAP which is in the lines and the resulting material was then compressed so that the absorbent The composite has a structure corresponding to 'in Figure 18. The weight of the SAP was 200 g / m2. Preparation of wood pulp toilet paper '(N) • Toilet paper available on the market of 30 g / m2 was prepared to be used to wrap a absorbent. Preparation of the highly absorbent compound (M / N / M ') A highly absorbent compound having a structure of (M / N / M') was obtained by means of laminate 25 of the aforementioned M, M 'and N so that the N is between the M and M 'as illustrated in Figure 18 and then compressed by means of a hot plate. The total weight of the compound • highly absorbent was 475 g / m2, and the SAP content 5 was 350 g / m2. It was confirmed that the highly absorbent compound is an absorbent compound having both acquisition and diffusion properties. • •

Claims

NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and therefore, it is claimed as • property contained in the following: CLAIMS 1. A highly absorbent composite sheet comprising a substrate of non-woven material, solid SAP, and a thermally fusible component, characterized in that: said non-woven substrate has a structure • bulky; part of said solid SAP is contained within said bulky structure and the remainder is exposed on the surface of said non-woven substrate; Said thermally fusible component is a hot melt adhesive; said hot melt adhesive forms a fibrous network; and said fibrous network covers said SAP solidly in contact with said solid SAP by means of which said solid SAP is held in its position.
2. The highly absorbent composite sheet according to claim 1, wherein said solid SAP particles are covered with fine cellulose.
3. The highly absorbent composite sheet according to claim 1, wherein the coated amount of said casting adhesive by • heat is from 0.2 to 10 g / m2.
4. The highly absorbent composite sheet according to claim 1, wherein said hot melt adhesive is composed primarily of ethylene-vinyl acetate copolymer and is non-tacky.
5. The highly absorbent composite sheet according to claim 4, wherein the content of vinyl acetate in the ethylene-vinyl acetate polymer which is the main composition of said hot melt adhesive is 15 of 20 to 40% by weight, and the thermal fluidity index of said hot melt adhesive is 50 to 150 g / 10 minutes.
6. The highly absorbent composite sheet according to claim 1, wherein said The nonwoven substrate has a bulky structure formed by means of a lifting treatment.
7. A highly absorbent composite comprising a composite absorber (M) which comprises a non-woven substrate, an SAP layer and a 25 hot melt adhesive forming a fibrous web covering said SAP layer, and a sheet material (N) placed on said adhesive layer; said composite absorbent (M) and said sheet material (N) being bonded together by said layer of hot melt adhesive by the adhesive property thereof to form a composite structure (M / N).
8. A highly absorbent composite comprising two absorbent compounds (M) and (M ') each comprising a non-woven substrate, an SAP layer and a layer of heat-melt adhesive forming a fibrous network that covers said SAP layer, said absorbent compound (M) being placed in the other absorbent compound (M ') in such a way that said layers of hot melt adhesive make contact with each other and being bonded together by the adhesive property of it to form a composite structure (M / M ').
9. A highly absorbent composite according to claim 8, wherein the additional sheet material (N) interposed between said composite absorbers (M) and (M '), and bonded thereto by the adhesive property of said casting layers. by heat of said composite absorbers (M) and (M ') to form a composite structure (M / N / M').
10. A method of manufacturing a highly absorbent composite sheet which comprises the steps of: forming a bulky structure by raising a non-woven substrate; application of a paste containing solid SAP to the raised surface of said nonwoven substrate, and subsequently removing the remaining liquid and drying it by means of which part of the solid SAP is contained in said bulky structure and the rest of the solid SAP is exposed in the surface of said non-woven substrate; and making a fibrous web of heat melt adhesive by means of a curtain spray apparatus, and then blowing said adhesive in the form of a curtain and forming a fibrous web on said nonwoven sub-surface and said solid SAP.
The method according to claim 10, wherein said elevated is made by making the surface of said non-woven substrate with a heating roller and subsequently after removing the surface of said heating roller, by contacting the surface of said nonwoven substrate with a cooling roller.
12. An absorbent article provided with a liquid pervious topsheet, a liquid absorbent, and an absorbent liquid retaining member and a liquid impermeable backsheet, wherein said liquid absorbing and liquid retaining member It comprises said highly absorbent composite sheet obtained by the method according to claim 10.
13. A highly absorbent composite sheet in which a part of the SAP is a solid contained in the voids of the non-woven material on a surface of a non-woven substrate and the rest of the solid SAP is distributed almost all in layers, exposed on the surface of the non-woven material, wherein the surface of said exposed solid SAP layer is covered by a dual fibrous network of a first dense maya fibrous web comprising heat melt adhesive and a second looser fibrous network of overlaid maya. said first fibrous network.
14. A highly absorbent composite sheet with little solid SAP output in which a part of the solid SAP is contained in the voids of the non-fibrous material on a surface of a non-fibrous substrate and the rest of the solid SAP is distributed almost all over layers exposed on the surface of the non-woven material, wherein the surface of said exposed solid SAP layer is covered by a dual fibrous network of a first dense maya1 fibrous network comprising heat melt adhesive and a • second fibrous network of loose maya placed | on said first fibrous network.
15. A highly absorbent composite sheet according to claim 13, wherein the fibers of said dense maya hot melt layer are finer than the fibers of said loose melt Maya melt layer.
16. A method for treating the surface of a highly absorbent composite sheet in which the solid SAP is distributed in layers on a surface of a non-woven substrate comprising a 15 combination of: a first step of heat melting treatment in which the hot melt adhesive is applied by means of a heat melting feed apparatus (A) to form a first iron net Fibrous maya dense comprising a hot melt adhesive on the surface where said solid SAP is distributed; and a second stage of heat melt treatment in which the hot melt adhesive is 25 applied by means of a heat melt feed apparatus (B) to form a second fibrous network of loose maya comprising a hot melt adhesive on said first fibrous web.
17. The method according to claim 16, wherein a first layer of dense maya hot melt adhesive is formed, leading said first step of the heat melt treatment in a range of applied amount of = 0.3 g / m2 to 2 g / m 2 and a second, more loose heat melting layer formed from said first stage of hot melt treatment leading said second stage of hot melt treatment in a range of applied amount of 1 g / m2 at 10 g / m2.
18. The method according to claim 17, wherein said first stage of the hot melt treatment is conducted in the range of an applied amount of g / m2 to 10 g / m2 and said second stage of the melt treatment by heat is performed in the range of an applied amount of 0.3 g / m2 to 2 g / m2 so that a second fibrous network of maya is formed denser than that made with the first heat-melt treatment.
The method according to claim 16, wherein said heat-melt feed apparatuses are used two units of a heat-melt feed apparatus of the curtain spray type to form a relatively short maya in series with respect to to the direction of movement of said non-woven substrate.
20. The method according to claim 16, wherein a first fibrous network of dense maya is formed using a heat casting apparatus of the curtain spray type as said first apparatus of the first stage of affc. 10 heat-melt feed and a second fibrous network of maya more loose than the first layer of heat-melt material using a heat-casting apparatus of the special coating type as said heat-melt feed apparatus. the second stage.
The method according to claim 16, wherein a first fibrous network of loose maya is formed using a special cast type heat-casting feeding apparatus such as said first stage heat-melting feeding apparatus. , and a second fiber web of denser maya than said first fiber network is formed using a feed apparatus of 25 heat casting of the curtain spray type as the heat casting feeding apparatus of said second stage.
22. The method of compliance with the claim • 16, where a first fibrous mesh of maya is formed 5 dense using a heat cast feeding apparatus of the curtain spray type as the first stage heat melt feed apparatus, and a second fibrous network of maya more loose than said first fibrous network is formed tk 10 using a heat-melt feed apparatus of the linear coating type as the heat-melt feed apparatus of the second stage.
23. The method according to claim 16, Wherein the first loose maya fibrous web is formed using a linear cast type heat cast feeding apparatus as the first stage cast iron feed apparatus, and a second network is formed The fibrous maya is denser than said first fibrous web using a heat cast feed apparatus of the curtain spray type as the heat-melt feed apparatus of said second stage. R-E-S-UM ^ E-N A highly absorbent composite sheet is provided, wherein a non-woven substrate has a bulky structure and a solid SAP with a part contained within said bulky structure! and the remainder exposed on the surface of said non-woven substrate, the thermally meltable component being a heat-melt adhesive, the heat-melt adhesive forming a fibrous web and covering said solid SAP and the fine cellulose fibers that are in contact with it. the solid SAP, so that a single or double fibrous network is supplied with the solid SAP maintained in its position. A method for manufacturing the same and an absorbent article using said highly absorbent composite sheet is also provided.