JP2007044118A - Disposable body fluid absorbent article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin, light-weight body fluid absorbent article, with excellent liquid absorbency, used with an absorber hardly moved or biased and exhibiting performance without being deformed. <P>SOLUTION: The disposable body fluid absorbent article is composed of a liquid permeable sheet, an impermeable sheet, and an absorbent complex interposed between the sheets. The absorbent complex is composed of a base material and a water-absorbent resin. The ratio of the resin to the total weight of the absorbent complex is 65-99 mass%, and the resin area filling factor is 1-30%. At least 50% of the total water-absorbent resin adheres to the base material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to disposable body fluid absorbing articles such as disposable diapers, sanitary napkins, urine pads, and breast milk pads that absorb and retain body fluids. In particular, the present invention relates to a body fluid-absorbing article that is thin and lightweight, has excellent liquid absorbability, has little liquid reversibility, is hardly displaced or biased, and is not deformed, and can stably exhibit absorption performance even under long-term use conditions. Furthermore, since it is excellent in liquid diffusibility, it is related with the bodily fluid absorption article with the high utilization efficiency of an absorber.

  In body fluid absorbent articles used for sanitary materials such as disposable diapers and sanitary napkins, absorbent bodies that absorb fluids such as body fluids, and flexible liquid-permeable surface sheets (top sheets) disposed on the side in contact with the body And a liquid-impermeable back sheet (back sheet) disposed on the opposite side in contact with the body.

  In recent years, there has been an increasing demand for thinner and lighter sanitary materials due to design problems, distribution problems, and dust problems. In order to cope with this, as a method generally used in the current sanitary material, there is a method in which the water-absorbing resin supporting carrier in the sanitary material such as fiber is reduced and a large amount of the water-absorbing resin is used. Hygienic materials with a reduced ratio of hydrophilic fibers and increased water-absorbing resin are preferable from the standpoint of simply storing liquids, but do not distribute or diffuse liquids in actual diaper usage. If you think about it, you will have problems. That is, a large amount of the water-absorbing resin becomes a soft gel upon absorption, causing a so-called gel blocking phenomenon that greatly hinders liquid diffusion. In order to avoid such problems and maintain the absorption characteristics of the absorbent body, the ratio of hydrophilic fibers to water-absorbent resin is naturally limited, and there is a limit in reducing hydrophilic fibers and making sanitary materials thinner. come.

  In the sanitary material, pulp is generally used as a fiber. However, clean virgin pulp is usually used among the pulps. If a large amount of fiber is used, it imposes a load on forest resources.

  As a means for reducing fibers and preventing gel blocking that occurs when a large amount of water-absorbent resin is used, a method of using two types of water-absorbent resins having different absorption performances (for example, see Patent Document 1), cationic ion exchange. A method using a composition containing a hydrogel-forming polymer and an anionic ion-exchange hydrogel-forming polymer (see, for example, Patent Document 2), and a method using a water-absorbing resin having a high surface crosslink density (see, for example, Patent Document 3). A method of foaming and extruding a mixture of a water-absorbent resin and a thermoplastic resin to form a sheet (for example, see Patent Document 4) has been proposed, but is unsatisfactory as an absorbent having a high water-absorbent resin concentration. There is a problem such as there is a high price. In addition, in these methods, the relative amount of hydrophilic fibers that have been responsible for fixing the water-absorbent resin is reduced, and thus there arises a problem that the particles of the water-absorbent resin are biased before use or move during use. Come. In this way, the water-absorbent resin is displaced from the designed position of the absorbent article, causing the mold to lose shape, and then the discharged urine or other liquid does not come into contact with the water-absorbent resin in the absorbent article, leading to leakage. Will arise. There is also a method (for example, refer to Patent Document 5) in which a mixing method of fibers and the water absorbent resin is devised in order to prevent blocking between the water absorbent resins and suppress bias. In this method, the water-absorbing resin and pulp are mixed together with water, and a mixture obtained by dry-mixing with hydrophilic fibers is air-formed on the web. Therefore, it can be said that the degree of mixing is high. However, the clogging of the water-absorbing resin becomes a problem in the process of air-making on a web. When clogging of the water-absorbent resin occurs, it is necessary to discharge from the drum, which leads to a decrease in productivity. In addition, in order to easily prevent clogging and discharge when clogged, it is necessary to use a water-absorbent resin having high hardness. Usually, a water-absorbing resin with high hardness tends to have a small absorption capacity, and a large amount of water-absorbing resin needs to be used in order to absorb a target amount of liquid. In addition, this method is not sufficient in terms of preventing the movement and bias of the water-absorbent resin in the product.

  In order to improve these problems, in particular, the problem of movement and bias of the water-absorbing resin, a method of fixing the water-absorbing resin to the support carrier has been studied. For example, a method of embossing the absorber, a method of including a thermoplastic binder fiber in an absorber composed of a water-absorbent resin and a hydrophilic fiber, and heat-sealing the absorber, a synthetic resin having a high recovery rate from strain A method of heat-sealing the absorber by containing it in an absorber composed of a water-absorbent resin and hydrophilic fibers (see, for example, Patent Document 6 and Patent Document 7), and the surface of the water-absorbent resin having an anionic group is cationic A method of coating a polymer and adhering and fixing particles through swelling (for example, see Patent Literature 8 and Patent Literature 9), a method of immobilizing a water-absorbent resin and a hydrophilic fiber using an emulsion binder, A method of fixing a water-absorbent resin to a substrate using a hot-melt adhesive (see, for example, Patent Document 10 and Patent Document 11). However, when the water-absorbing resin is fixed to the base material using the binder as described above, there arises a problem of restriction of swelling of the water-absorbing resin due to restriction of the binder force. In particular, when the water-absorbing resin and the hydrophilic fiber are fixed with a thermoplastic binder or emulsion, there is a problem that the absorbing ability of the water-absorbing resin cannot be sufficiently exhibited. As a technique for relaxing the swelling restriction of the water-absorbent resin by such immobilization, the water-absorbent resin partially encapsulated inside the bulky nonwoven fabric and coated with fine cellulose fibers is removed with a net-like hot melt fiber. Absorbent composite coated from the surface (see, for example, Patent Document 12), a water-absorbent resin partially encapsulated inside a bulky nonwoven fabric and partially exposed from the surface is made of double layers with different net meshes. An absorbent composite sheet (see, for example, Patent Document 13) coated from the outer surface with a net-like hot melt fiber is also known. However, these methods relax the swelling regulation, but have a problem that the absorption characteristics change due to immobilization. As the absorption characteristics of the water-absorbent resin, in addition to the well-known absorption ratio, absorption rate, absorption ratio under pressure, diffusion absorption ratio under pressure, liquid permeability of swollen gel, etc., There is an absorption characteristic (for example, see Patent Document 14 and Patent Document 15) based on the capillary force of the particle gap, which is the capillary absorption magnification. It has been found that the absorption characteristics of the water-absorbing resin, such as the capillary absorption rate, are greatly influenced by the conventional immobilization means. That is, even when a high-performance water-absorbent resin is used, the absorption characteristics of the absorbent body obtained by immobilization often cannot reflect the absorption characteristics of the original water-absorbent resin. In addition, there is a description that the performance of a water absorbent resin that can be used as long as a certain minimum performance is satisfied (for example, see Patent Document 16). Differences in properties were less likely to appear and it was difficult to differentiate the absorber.

  There is also an example in which an absorbent gel is bonded to a chemically stiffened cellulose fiber using an adhesive (see, for example, Patent Document 17). In this method, the chemically stiffened cellulose fiber secures the swelling space of the absorbent gel, the water-absorbing resins are substantially separated from each other, and the performance of the original water-absorbing resin is easily exhibited. it is conceivable that. However, the fibers are not fixed to each other, and the movement of the fiber in the absorbent body is inevitable, and as a result, the movement of the absorbent gel is considered to occur. In addition, it is necessary to wrap the absorbent gel with cellulose fibers to ensure a swelling space, to use a large amount of cellulose, and the swelling space is not sufficient. Furthermore, since an adhesive is also necessary, it is considered that the regulation of swelling is inevitable. There is an example (for example, refer to Patent Document 18) in which the base material and the crosslinking agent are used for adhesion. In this method, it seems that an absorptive complex having good liquid permeability is obtained by using a crosslinking agent having no swelling restriction, making particles low in basis weight, preventing gel blocking. However, a cross-linking agent is required for adhesion, and it is considered that the absorption capacity of the particles is reduced by partially cross-linking the particles. Further, there is a description that the performance under load is improved by increasing the surface cross-linking degree, and it is considered that the anti-blocking effect is not sufficient. Furthermore, since the particles are used so as to have a low basis weight, the absorbability as a composite is low.

  There is also an example in which a water-absorbing resin is immobilized on a substrate without using a binder. For example, there is a method (see, for example, Patent Document 19) in which absorbent polymer particles during polymerization are attached to a fibrous base material and polymerization is performed on the fibrous base material. In this method, the fibrous base material enters the polymer particles and is firmly fixed, but it is difficult to complete the reaction in the base material, and it is considered that there are many residual monomers and residual crosslinking agents. There is also an example in which a certain amount or more of an aqueous monomer solution is supported in a fine particle form on a nonwoven fabric that has undergone napping treatment, and then polymerized and thermally compressed (see, for example, Patent Document 20). In this example, since the amount of the water-absorbing resin is large, the absorption performance as a composite is high, and since a nonwoven fabric is used, movement is less likely to occur than with pulp. However, in this example as well, the residual monomer becomes a problem because of polymerization in the nonwoven fabric. There is also an example in which a water-absorbent resin is applied as a slurry to a substrate (for example, see Patent Document 21). By applying as a slurry, the productivity is surely increased, but it is necessary to use expensive microfibrils as a dispersion medium, and it is considered that the adhesive force is not sufficient. In absorbent articles such as thin sanitary materials with an increased ratio of water-absorbing resin, the amount of water-absorbing resin used is increased, and depending on the arrangement position, the resin may swell after liquid absorption, resulting in considerable bulkiness. is there. There is also a problem that the body pressure due to the bulkiness tends to increase as the water-absorbent resin is firmly fixed.

In addition, sanitary materials are required to have less stuffiness in addition to leakage in terms of wearing feeling. Conventionally, an absorbent article has been proposed in which an increase in humidity during wearing is suppressed to reduce stuffiness (see, for example, Patent Document 22 and Patent Document 23). The technologies described in these publications include an absolutely dry pulp, a large amount of superabsorbent polymer, a hygroscopic material such as silica gel and lithium chloride in the absorber, and a combination of a moisture permeable back sheet. is there. There is also an absorbent article using a moisture-permeable back sheet (see, for example, Patent Document 24). By combining two sheets having moisture permeability, it is a technique that prevents the liquid from oozing out through the moisture-permeable back sheet even under pressure. However, even in these techniques, the excreted body fluid remains as a liquid that is not fixed between the fibers of paper and pulp, so that when the amount of fluid excreted is large, water vapor is generated from the liquid that is not fixed. This tends to cause stuffiness. In addition, a sanitary napkin (for example, a liquid that is prevented from returning from the absorbent by using an absorbent having a centrifugal retention capacity and a simulated blood permeation rate after the equilibrium absorption and swelling of the simulated blood, respectively, of a predetermined value or more. Patent Document 25) or a multilayer absorbent paper made by mixing bulky cellulose fibers and having a surface layer in contact with the liquid first and one or more base layers layered thereon (see, for example, Patent Document 26) )), An absorbent sheet containing hydrophilic fine fibers or hydrophilic fine powder in an absorbent sheet containing a superabsorbent polymer and bulky cellulose fibers (see, for example, Patent Document 27) is also proposed. Has been. However, even in these publications, even when the excretion amount (liquid absorption amount) is large, the generation of water vapor can be remarkably suppressed and the structure of the absorbent article that can remarkably suppress the generation of stuffiness is not described at all. . As a method for suppressing the occurrence of stuffiness, there is also a method using a fiber having a small water holding amount in the absorbent layer (see, for example, Patent Document 28). Although this method certainly reduces stuffiness, the fiber hardly acts as an absorber, so that it relies on absorption of a water-absorbent resin having a low absorption rate, and the absorption rate becomes slow. Moreover, since there is little expansion | swelling of a fiber at the time of swelling, it is easy to raise | generate gel blocking and it is hard to exhibit the performance of a water absorbing resin.

  In this way, a disposable body fluid absorbent article that uses a thin absorbent body that can simplify the manufacturing process of sanitary materials and that also has a high ability to retain liquid, is thin and lightweight, and has a high body fluid retaining ability. It was not done.

  In addition, it consists of a flexible liquid-permeable top sheet (top sheet) placed on the side in contact with the body, a liquid-impermeable back sheet (back sheet) placed on the opposite side in contact with the body, and an absorbent body In the body fluid absorbent article to be used, there is a problem of deviation or bias of the absorbent body itself in the article during transportation or wearing. As a means for preventing the absorber from being displaced or biased during transportation or use, the absorber is generally fixed with a hot-melt adhesive. (For example, refer to Patent Documents 29 and 30.) However, in this method, if the amount of the adhesive is small, the core and the tissue paper are easily peeled off. If the amount of the adhesive is increased, the flexibility of the sheet is lowered and the water permeability of the crossing portion of the adhesive is hindered. There is a problem. There is also an example in which the adhesive application method is devised to balance the adhesive strength and flexibility (see, for example, Patent Document 31). However, although the balance between adhesive strength and flexibility is improved, it is difficult to say that the level is satisfactory. Furthermore, since the mixture of fibrous materials, such as a pulp, and a water absorbing resin is used as an absorber, a fiber and a water absorbing resin move easily inside an absorber, and it is difficult to exhibit absorptive performance stably. In addition, there is a problem that fibers and water-absorbent resins are likely to leak onto the surface of the body fluid absorbent article. In order to suppress leakage, the absorbent core is used by being embraced with a tissue or the like, but the tissue is easily broken and cannot be said to be sufficient.

In the body fluid absorbent article, not only the absorbent capacity of the absorbent body but also the reversibility of the absorbent once absorbed is important. A technique for providing a liquid-absorbent core by providing a fiber aggregate layer on the upper surface of the absorbent core for providing an effect such as cushioning and prevention of reverse return of the absorbent is known. For example, the liquid retaining layer is composed of pulp fibers and 10 to 60% by weight superabsorbent polymer particles, and a tissue paper layer and a short fiber fluff layer are sequentially stacked on the upper surface, and if necessary, a tissue paper layer is further formed thereon. There is a technique in which the whole is covered with a surface material such as a nonwoven fabric to form a liquid-absorbent core (see, for example, Patent Document 32). Also, there is a technique in which an aggregate of cotton-like pulp containing a superabsorbent polymer is coated with tissue paper to form a liquid retaining layer, and a fiber aggregate layer having a required compression elastic recovery rate is provided on the upper surface (for example, Patent Document 33). reference.). However, in these techniques, the liquid-retaining layer in which the superabsorbent polymer particles occupy 30% by weight or more and the pulp becomes 70% by weight or less is obtained even if the pulp is molded under pressure. The entanglement is blocked by polymer particles, making it very brittle. When a liquid-absorbent core composed of such a liquid-retaining layer is used, there is a problem that the liquid-retaining layer is finely loosened by the movement of a person and hinders diffusion and rapid absorption of body fluids. In order to prevent the liquid-absorbent core from being deformed, there is an example in which the liquid retaining layer and the fiber assembly layer are simultaneously wrapped and joined with tissue paper (see, for example, Patent Document 34). However, the liquid retaining layer is also a mixture of pulp and water-absorbing resin, and the liquid retaining layer itself is easy to move and it is difficult to stably exhibit the liquid absorbing performance, so it can be said that the reversible performance is satisfactory. Absent. Furthermore, the diffusion relies on a small amount of tissue for the absorber, and it is considered that the utilization efficiency of the absorber is inferior. In particular, considering the strength of the tissue once absorbed, it is considered that there is a problem in the diffusibility after absorbing.
JP 2001-252307 A International Publication No. 98/037149 Pamphlet Japanese Patent Laid-Open No. 06-057010 International Publication No. 01/64153 Pamphlet Japanese Patent Laid-Open No. 5-230747 JP-A-10-118114 JP-A-10-118115 JP-A-5-31362 JP-A-6-370 JP 2000-238161 A Japanese National Patent Publication No. 10-510447 JP 2001-96654 A JP 2001-171027 A Japanese Patent Application No. 2002-72476 Japanese Patent Application No. 2001-375375 JP 2001-96654 A Japanese Patent Laid-Open No. 10-512183 Japanese National Patent Publication No. 10-508528 JP 2003-11118 A JP 2004-124303 A JP-A-11-137600 JP-A-6-218007 JP-A-7-132126 Japanese National Patent Publication No. 10-508521 Japanese Patent Laid-Open No. 7-184958 JP-A-6-28788 Japanese Patent Laid-Open No. 9-156013 JP 2002-165837 A JP-A-8-196559 JP 2001-95837 A JP 2004-201719 A Japanese Utility Model Publication No. 52-99046 Japanese Patent Publication No. 6-38818 Japanese Patent No. 3333979

  An object of the present invention is to provide a bodily fluid absorbent article that is thin, lightweight, and excellent in liquid absorbency. Another object of the present invention is to provide a bodily fluid absorbent article that exhibits almost no movement and bias of the absorbent body during use, does not lose its shape, and can exhibit performance. Furthermore, since it is excellent in liquid diffusibility, the utilization efficiency of an absorber is high, but it is providing the bodily fluid absorbent article which is excellent in the diffusibility to the vertical direction, and does not occur sideways. It is another object of the present invention to provide a comfortable bodily fluid-absorbing article in which particulate matter and fibrous substances do not leak to the surface of the bodily fluid-absorbing article, and the absorbed liquid is less reversible.

As a result of intensive studies to achieve the above-mentioned problems, the substrate and the water-absorbent resin are used as raw materials, and the substrate and the water-absorbent resin have a specific ratio and a specific arrangement so that the water absorbency exceeds a certain level. By using an absorbent composite in which a resin is bonded to a base material between a liquid-permeable sheet and a liquid-impervious sheet, a fluid-absorbing article that does not easily move, bias, or lose shape of the absorbent is provided. I found out that I can do it. In addition, this absorbent article is thin and light, yet has high absorption performance, and also has high liquid diffusibility and high utilization efficiency of the absorber. Invented. That is, the following body fluid absorbent article.
(1) A disposable humor absorbent article composed of a liquid permeable sheet, a liquid impermeable sheet, and an absorbent composite interposed therebetween, wherein the absorbent composite is composed of a base material and a water absorbent resin. The resin ratio is 65% by mass or more and 99% by mass or less with respect to the total absorbent composite weight, the resin area filling rate is 1 to 30%, and 50% or more of the total water-absorbing resin is adhered to the base material. Disposable body fluid absorbent article characterized by the above.
(2) The body fluid-absorbing article according to (1), wherein the base material of the absorbent composite is cloth and / or paper.
(3) The body fluid-absorbing article according to any one of claims 1 to 2, wherein the water-absorbing resin is adhered to the substrate without an adhesive.
(4) The water-absorbent resin has a particle shape, and 50% or more of the particles are an absorptive composite in which a part of the base fiber is taken in the water-absorbent resin particles. The bodily fluid absorbent article according to any one of (1) to (3), wherein
(5) The surface strength of the water-absorbent resin in the absorbent composite is from 0.1 N to 5.5 N, and the non-pressure absorption capacity of the water-absorbent resin is 55 g / g or more (1) -The bodily fluid absorption article in any one of (4).
(6) The water absorbent resin in the absorbent composite is a resin having a carboxylic acid group in the side chain, and 50% or more of the acid groups in the water absorbent resin are neutralized in the form of an ammonium salt. (1)-The bodily fluid absorption article in any one of (5).
(7) The body fluid-absorbing article according to any one of (1) to (6), wherein the water-absorbing resin is a polyacrylate copolymer.
(8) The body fluid-absorbing article according to any one of (1) to (7), wherein the base material of the absorbent composite is cellulose.
(9) The article according to any one of (1) to (8), wherein the absorbent composite, the liquid-permeable sheet and / or the liquid-impermeable sheet are fixed with an adhesive.
(10) A disposable body fluid absorbent article composed of a liquid permeable sheet, a liquid impermeable sheet, and an absorbent composite interposed therebetween, wherein the absorbent composite is composed of a base material and a water absorbent resin. A body fluid-absorbing article having a resin ratio of 65% by mass to 99% by mass and a liquid diffusion length of 200 mm or more with respect to the total weight of the absorbent composite.
(11) The body fluid-absorbing article according to (10), wherein the absorbent composite has an area weight of 0.05 g / cm ² or less and an absorption ratio of 40 g / g or more.

According to the present invention, it is possible to provide a comfortable bodily fluid absorbent article that is thin, lightweight, and has a low liquid reversibility. Moreover, since the diffusibility of a liquid is high and the utilization efficiency of an absorber is high, it is possible to provide an environmentally friendly disposable article that does not require useless materials.

The present invention will be described in detail below.
(About body fluid absorbing articles)
It is a disposable body fluid absorbent article composed of a liquid permeable sheet, a liquid impermeable sheet and an absorbent composite interposed therebetween, wherein the absorbent composite is composed of a base material and a water absorbent resin, and the entire composite The disposable body fluid absorbent article is characterized in that the resin ratio is 65% by mass or more and 99% by mass or less with respect to the weight, and 50% or more of the total water-absorbing resin is adhered to the base material. The resin area filling rate of the absorbent composite is preferably 1 to 30%. The bodily fluid absorbing article in the present invention refers to all articles having the ability to absorb bodily fluids. The body fluid to be absorbed in the present invention is not particularly limited, and examples thereof include urine, menstrual blood, breast milk, and loose stool. The shape of the article is not particularly limited, but a pad shape, a tape type, a pants type, or the like is preferably used. Specific examples include diapers, sanitary napkins, urine pads, and breast milk pads.

  The absorptive composite used in the present invention is sheet-like and stable in shape, and has a high absorbency even though it is thin and lightweight. When this absorptive composite is combined with a liquid-permeable sheet and a liquid-impermeable sheet, a body fluid-absorbing article having a high liquid-absorbing ability although being thin and light can be constituted. In addition, since the absorber does not easily shift or move in the body fluid absorbent article during use, the body fluid can be stably absorbed. Furthermore, compared with the conventional body fluid absorbent article, since the ratio of the absorbent resin is high, the amount of liquid that has been absorbed once when a load is applied, that is, the return amount is small. Therefore, the mounting portion can be kept comfortable.

  In the present invention, the liquid-permeable sheet is a sheet shape, and any sheet may be used as long as it allows water to pass through when the sheet is sprayed with water, but a cloth as defined in JISL0206. It is preferable that Fabrics are classified into woven fabrics, knitted fabrics, braided fabrics, laces, nets, and non-woven fabrics depending on the means for forming the sheet. preferable. In order to eliminate the moist feeling of the part in contact with the skin and make the touch comfortable, a sheet having a low water absorption capacity made of a polyolefin such as polyethylene and polypropylene is preferable. It is preferable that it is a polyolefin system which has been subjected to hydrophilization treatment.

  In the present invention, the liquid-impervious sheet may be any sheet as long as it has a sheet shape and does not transmit water. From the viewpoint of preventing dampness, a material having good air permeability is preferable.

  In the bodily fluid absorbent article of the present invention, there is no problem if there is at least a liquid-permeable sheet, an absorbent composite interposed between the liquid-impervious sheet, but between the liquid-permeable sheet and the absorbent composite, and / or Alternatively, other members may exist between the liquid-impermeable sheet and the absorbent composite. Further, other members may exist outside the liquid-permeable sheet and the liquid-impermeable sheet. Examples of the member used here include fibrous materials such as pulp, particulate materials such as a water-absorbing resin, and sheet materials such as tissue, cloth, and paper. In the body fluid absorbent article, in addition to the liquid permeable sheet, liquid impermeable sheet, and absorbent composite, for example, tape and rubber for fixing to the body, gathers for preventing side leakage, etc. It is preferable that there is.

  In the present invention, the absorbent composite may have any shape as long as the absorbent composite is interposed between the liquid-permeable sheet and the liquid-impervious sheet. For example, the shape may be a combination of a square, a perfect circle, a rectangle, an ellipse, or a trapezoid, or an indefinite shape. In the case of a diaper, a sanitary product, a urine collection pad, etc., it is preferable that the shape has a rectangular shape or an elliptical shape, or a shape having a longitudinal direction and a short direction corresponding thereto. An example of the shape of the absorbent composite having the longitudinal direction is shown in FIG. There may be a part to be used for bonding the absorbent composite to other members. In addition, there may be a marginal portion where the absorbent resin does not exist in the absorbent composite, but the absorbent composite ratio and area filling rate of the absorbent composite are omitted in the state where the absorbent composite is omitted. It is preferable that the preferable range of conditions for the body is satisfied. The number of absorbent composites used may be one, or a plurality of sheets may be used. In order to construct a thin article, it is preferable to use only one sheet. It is preferable to use a plurality of sheets in order to construct an article having a higher absorbency. When using a plurality of sheets, they may be used in a stacked manner, or may be used side by side. Moreover, the thing of the completely same shape may be used, and the thing of a different shape may be used. In order to improve the absorption capacity without waste, it is preferable to use only the part where the body fluid is secreted, and when it is desired to prevent leakage, it is preferable to use the part that is likely to leak.

The state of the absorbent composite in the body fluid absorbent article is not particularly limited, and the absorbent composite sheet may be in a fully stretched state, in a wrinkled state, or in a folded state.
(About the absorbent complex)
In the present invention, a combination of a water-absorbing resin and a substrate is called an absorbent composite. In this case, the method of combination is not particularly limited, and may be bonded, a substrate may be entangled with a water-absorbing resin, or may be just mixed. The water-absorbent resin and the base material may be combined one by one or a plurality of combinations. Moreover, you may combine short fibers, such as a pulp, and another material simultaneously. In the present invention, the relationship between the substrate and the water absorbent resin is very important. If the weight ratio of the water-absorbent resin is too low with respect to the weight of the entire absorbent body, the amount of absorption as the absorbent body is reduced, which is not preferable. If the water-absorbing resin is arranged too densely, blocking occurs and the swelling is inhibited. When blocking occurs, the absorption performance of the water-absorbent resin cannot be exhibited sufficiently, which causes a decrease in absorption performance as an absorber, which is not preferable. In order to prevent blocking, it is preferable to arrange at a density of the water-absorbent resin such that the area filling rate is 1 to 30%, more preferably to avoid contact between particles, and at regular intervals. More preferably, a water-absorbing resin is disposed. Moreover, it is preferable to arrange | position to one layer so that a water absorbing resin may not overlap, and it is preferable to arrange | position a particle | grain on both surfaces of a base material in order to raise a particle ratio. Since the water-absorbing resin arranged in this manner can sufficiently exhibit the absorption performance without being inhibited from swelling, it can exhibit high absorption performance as an absorbent composite. In the present invention, it is essential that 50% or more of the water-absorbing resin is adhered. More preferably, 70% or more, still more preferably 90% or more, and most preferably 95% or more of the water-absorbing resin is adhered. It is preferable that the water absorbent resin is bonded to the base material because the water absorbent resin can be prevented from moving during transportation or liquid absorption. The bonding method is not particularly limited, but a method that does not use an adhesive is preferable, and it is more preferable to bond in a form in which a part of the fibers of the base material is incorporated in the water-absorbent resin. It is preferable that 50% or more of the water-absorbing resin in the bonded water-absorbing resin is bonded in a form in which a part of the fiber is taken into the water-absorbing resin, more preferably 70% or more, and still more preferably. 90% or more, most preferably 95% or more of the water-absorbing resin is bonded in this form. If an adhesive is not used, it is preferable because it is not subjected to swelling regulation during liquid absorption. If a part of the fibers are bonded in a form incorporated in the water-absorbent resin, the fiber becomes a water passage when the water-absorbent resin absorbs the liquid, and the absorption speed is improved. For this reason, a water absorbent resin having a relatively large particle size, which was not preferred for use in an absorber, can be used. When a water absorbent resin having a large particle diameter is used, the ratio of the water absorbent resin can be increased without increasing the area filling rate, so that the absorbent composite can have high absorption performance. In addition, it is preferable to use a water-absorbent resin having a large particle size because the amount of swelling in the vertical direction also increases, so that the amount of absorption per area can be improved. When a part of the fibers are bonded in a form incorporated in the water absorbent resin, the absorbency under pressure, which is regarded as important as the performance of the water absorbent resin, is also improved. In order to increase the absorption capacity of the water-absorbent resin under pressure, a hard resin with a low absorption capacity has been used in the past, but in the present invention, blocking is avoided by the arrangement, and further, there is a water passage in the resin. Even when a soft resin having a high capacity is used, a high absorbency under pressure can be exhibited. As a result, an absorptive complex having a high absorption capacity can be obtained both under no pressure and under pressure. When blocking between water-absorbing resins occurs, liquid diffusion is also hindered, but the composite absorbent body of the present invention has high liquid diffusibility and can exhibit the absorption performance of all water-absorbing resins, so that excess water absorption The absorbent composite can be reduced in weight without using an absorbent resin.

(About the base material)
In the present invention, the base material refers to a material that can maintain a sheet shape. In the present invention, the base material may be any material as long as it is in sheet form, but is preferably paper and / or cloth. Paper refers to paper in a broad sense defined by JISP0001, and cloth is a generic term for sheet-like fiber products defined by JISL0206. The cloth is classified into a woven fabric, a knitted fabric, a braided article, a lace, a net, and a non-woven fabric depending on the means for forming the sheet. Paper and / or cloth is preferable because it has excellent shape stability unlike short fibers such as pulp. Nonwoven fabric is defined by JISL0222. The shape of the substrate is not particularly limited, and the thickness is preferably 0.001 mm to 1 cm, more preferably 0.01 mm to 5 mm, still more preferably 0.05 mm to 3 mm, and most preferably 0.1 mm to 1 mm. Weight preferably ^{0.1g / m 2 ~1kg / m 2} , more preferably from ^{0.5g / m 2 ~500kg / m 2} , more preferably ^{1g / m 2 ~100g / m 2} . Those that are too thin or light are not preferred from the standpoint of strength. In the present invention, the tensile strength at break after physiological saline is preferably 0.6 to 5000 N / 20 mm, more preferably 0.7 to 500 N / 20 mm, and 0.85 to 100 N / 20 mm. Is more preferable, and most preferably 1 to 100 N / 20 mm. In the present invention, the tensile strength at break after absorption of physiological saline represents the tensile strength at break after the substrate has absorbed physiological saline. In sanitary materials, they may be used as they are without being replaced immediately after liquid absorption. Moreover, after liquid absorption, liquid absorption over several times may be calculated | required. If the use is continued after absorbing once, a load is applied in a state where moisture exists in the absorber. If the substrate breaks due to the load, the liquid permeability and liquid diffusibility are lowered, and the performance of the absorber is deteriorated. It can be said that a base material that maintains a high strength even after absorption of physiological saline is preferable in terms of durability of the absorbent body. Further, in the case of a process in which the base material contains water at the time of production, there may be a problem if the strength at the time of water inclusion is low, and it can be said that the higher the strength of the base material, the better. However, even if the strength is too high, there is virtually no difference in performance.
The tensile strength at break after absorption of physiological saline is determined as follows.
Sample: 15 cm × 2 cm rectangular base material (preparing several types by changing direction)
Equipment: Tensile tester (Shimadzu autograph)
Method: 700 g of 0.9% saline is taken in a 1 L beaker and the substrate is immersed for 10 minutes. The substrate is pulled up, left on a Kim towel for 1 minute, and a portion of 2.5 cm is set from both ends so that the distance is 10 cm, and the substrate is pulled until it breaks at a speed of 10 mm / min. The force at this time is recorded, and the maximum value is the strength N / 20 mm. If there is a direction, change the direction and make several points, and use the lowest value as the strength.

  Any raw material may be used for the base material, and a plurality of combinations of base materials may be used. The base fiber includes both natural fiber and synthetic fiber, and a combination of a plurality of fibers may be used. The length of the fiber may be short fiber or long fiber. A treatment may be applied for strengthening or imparting hydrophilicity. Hydrophilic materials are more preferable than hydrophobic materials because they are superior in liquid absorption and water permeability. In addition, continuous long fibers are more preferable than short fibers because they are superior in liquid permeability. Of the hydrophilic substrates, cellulose-based substrates are particularly preferable. The cellulosic substrate in the present invention represents a cloth and / or paper having cellulose as a main raw material. Cellulose may be derivatized by treatment such as esterification or etherification. Moreover, what was mixed with the other fiber may be used. Examples of cellulose include natural fibers such as cotton and hemp, and regenerated fibers such as rayon, polynosic, lyocell, and cupra. As the fiber, a regenerated fiber is preferable, and a fiber obtained by regenerating a cotton seed which is an annual plant is more preferable.

  As an index indicating the hydrophilicity and liquid permeability of the substrate, there are an absorption rate and an absorption rate. This will be described next.

  In the present invention, the absorption rate of the base material is a value measured by measuring how many times the base material absorbs 0.9% physiological saline in 60 minutes, and is specifically as follows. Measure by method. The substrate is cut into a circle having a diameter of 59.5 mm, and the weight is recorded. Then, a wire is passed through the circumferential portion at a distance of 1 cm. 500 g or more of 23 ° C. physiological saline is prepared in a 1 L beaker, and the substrate is dipped in the physiological saline together with the wire. After 60 minutes, the substrate together with the wire is taken out from the physiological saline and suspended for 10 minutes so that the substrate does not come into contact with the other. Ten minutes later, the wire is removed and the total weight of the water-containing base material and the attached water is measured.

Absorption capacity of substrate (g / g) = weight after absorption (g) / weight before absorption (g)
In the present invention, the absorption capacity of the substrate is preferably 2 g / g or more and 200 g / g or less, more preferably 4 g / g or more and 100 g / g or less, still more preferably 8 g / g or more and 50 g / g or less. Most preferably, it is 12 g / g or more and 30 g / g. In the absorbent composite, the fiber absorbs faster than the water-absorbent resin, so that the base material absorbs at the initial stage of absorption and the water-absorbent resin absorbs at the later stage. A higher absorption rate of the substrate is preferable because an initial liquid absorption rate is increased. Usually, the absorption of the substrate is due to capillary action, and when a load is applied, the liquid may return or may cause stuffiness during use. However, in the absorptive composite of the present invention, since the resin is bonded in the form of taking up the fibers of the base material, the water-absorbing resin absorbs the liquid from the base material. For this reason, it is unlikely that the liquid will return due to the load or stuffy during use.

  In the present invention, the absorption rate of the substrate represents a rate at which the substrate having a width of 2 cm absorbs 0.9% physiological saline in the vertical direction. The absorption rate of the substrate is preferably 0.35 mg / second or more and 100 mg / second or less, more preferably 0.45 mg / second or more and 50 mg / second or less, further preferably 0.55 mg / second or more and 30 mg / second or less, Most preferably, it is 0.65 mg / second or more and 10 mg / second or less.

Specifically, the absorption rate of the substrate is measured as follows.
Sample: For a 10 cm x 2 cm rectangular base material with vertical and horizontal directions, change the direction and prepare two or more points: Electronic balance, petri dish with a diameter of 90 mm Method: Place a petri dish on the electronic balance and place the base material on the petri dish Suspend vertically from 10cm above. The petri dish is taken from the electronic balance, and 60 g of 0.9% physiological saline is weighed with another balance. Hold the lower part of the base material by hand and place the petri dish again on the electronic balance so as not to touch the physiological saline, and set the value of the balance to 0 point. The substrate is gently soaked in physiological saline, and the value of the electronic balance is recorded over time. The time (second) and the absolute value (mg) of the value of the electronic balance are plotted on a graph, and the slope (mg / second) between 120 seconds and 240 seconds is taken as the absorption rate. If the substrate has a direction, change the direction, measure several points, and take the fastest value as the absorption rate.

  It can be said that it is preferable that the substrate has directions with different absorption rates. When a direction exists in the substrate, the liquid permeability in a specific direction is excellent and the liquid is easily diffused in the specific direction, so that the balance of absorption in the absorber can be controlled. The shape of the substrate may be anything, but in the body fluid absorbent article, the shape of the absorbent body is not a non-directional shape such as a square or a circle, but a shape having a major axis and a minor axis such as a rectangle. It is preferable that At this time, if the liquid diffuses concentrically, leakage from the minor axis direction is likely to occur, and it is preferable that the diffusion in the major axis direction occurs preferentially.

  When a direction exists in the base material, strength and elongation change in each direction. In the present invention, the direction having the maximum intensity is defined as the longitudinal direction, and the direction perpendicular thereto is defined as the lateral direction. The ratio of the strength in the vertical direction and the horizontal direction is preferably 1.2 times or more, more preferably 1.5 times or more, and most preferably 2 times or more. The ratio of elongation in the longitudinal direction to the transverse direction is preferably 1.2 times or more, more preferably 1.5 times or more, and most preferably 2 times or more. The elongation and strength of the base material can be determined by conducting a tensile test in a dry state without being immersed in physiological saline in the same manner as the strength of the base material after absorption of physiological saline. The tensile test is performed until the base material breaks, and the force at the maximum strength is defined as the strength of the base material, and the distance stretched at that time is defined as the elongation.

The base material in the present invention is preferably a nonwoven fabric having a contact angle of 130 degrees or less. The contact angle in the present invention is defined as an angle formed after 10 seconds after a 44% ammonium polyacrylate aqueous solution having a viscosity of 74 cp is brought into contact with a substrate at 25 ° C. The measurement is performed using a contact angle meter (CA-X150 type) manufactured by FACE (Kyowa Interface Science Co., Ltd.). The liquid is a Wako Pure Chemicals 44% ammonium polyacrylate aqueous solution (70 to 110 cp), which is used after adjusting the viscosity with water. Viscosity is measured using a rotating disk viscometer.

The contact angle is preferably 130 degrees or less, more preferably 120 degrees or less, still more preferably 110 degrees or less, and most preferably 100 degrees or less. The smaller the contact angle, the higher the affinity between the base material and water, and the base material and the water-absorbent resin, which is preferable in terms of absorbability and adhesiveness.
(Description of water absorbent resin)
In the water absorbent resin used in the present invention, the residual monomer concentration relative to the weight of the water absorbent resin is preferably 1% by mass or less, more preferably 0.1% by mass or less, still more preferably 0.05% by mass or less, More preferably, it is 0.01 mass% or less, Most preferably, it is 0.005 mass% or less. When there are many residual monomers, there are many elution components at the time of liquid absorption, and it is not preferable in terms of performance. The residual monomer concentration of the water absorbent resin as a starting material is preferably 10% or less, more preferably 5% or less, still more preferably 1% or less, and most preferably 0.1% or less. preferable. If a water-absorbing resin having a large amount of residual monomer is used, it is difficult to complete the reaction, and depending on the reaction method, the texture of the substrate may be impaired, which is not preferable.

The kind of the water absorbent resin of the present invention is not particularly limited, and any water absorbent resin may be used. A water-absorbing resin having an acid group in the side chain is preferred, and a resin having a carboxylic acid group in the side chain is more preferred. 50% or more of the acid groups are preferably neutralized in the form of a salt, and more preferably 50% of the acid groups are neutralized in the form of an ammonium salt. A water-absorbent resin having an acid group in the side chain is preferable because an electrostatic repulsion between acid groups occurs during liquid absorption and the absorption speed is increased. It is preferable that the acid group is neutralized because the liquid is absorbed into the water-absorbent resin by osmotic pressure. When neutralized in the form of an ammonium salt, the ammonium salt is preferable because of its high affinity for water and an increased amount of absorption. Examples of the water-absorbing resin include a crosslinked polyacrylic acid partially neutralized product (see, for example, JP-A-55-84304) and a hydrolyzate of starch-acrylonitrile graft polymer (see, for example, JP-B-49-43395). ), Neutralized starch-acrylic acid graft polymer (see, for example, JP-A No. 51-125468), saponified vinyl acetate-acrylic acid ester copolymer (see, for example, JP-A-52-14689) There are many known hydrolysates of acrylonitrile copolymer or acrylamide copolymer (see, for example, Japanese Patent Publication No. 53-15959), polyglutamate (see, for example, Japanese Patent Application Laid-Open No. 2003-192794). From the viewpoints of absorption performance, cost, etc., a polyacrylic acid partial neutralized product crosslinked product usually used for hygiene materials is preferred. The shape of the water-absorbing resin may be any shape, may be an irregularly crushed shape, a tuft shape of a cocoon, a spherical shape, or the like, a slurry shape, a liquid shape, a fiber shape, or a sheet shape. The particulate form is preferable in terms of form stability after water absorption and water absorption speed.

Below, the manufacturing method of the polyacrylic acid partial neutralized material crosslinked body is mention | raise | lifted as a preferable example of the water absorbing resin to be used.

  In the polyacrylic acid crosslinked product, preferably 50 mol% or more of the repeating units in the polymer molecular chain are carboxyl group-containing units. More preferably, it is 80 mol% or more, and most preferably 90 mol% or more. If the carboxyl group-containing unit among the repeating units is 50 mol% or less, a decrease in absorption performance is observed, which is not preferable.

  The carboxyl group in the polymer molecular chain is preferably partially neutralized, and examples of the salt include alkali metals such as sodium, potassium and lithium, and nitrogen-containing basic substances such as ammonia. 50% or more of the carboxyl groups are preferably neutralized, and more preferably 70% or more are neutralized. As a kind of salt, it is preferable to be partially neutralized with at least one kind including ammonia, and most preferably partially neutralized with ammonia alone. From the viewpoint of absorption performance, 50 mol% or more of the carboxyl group neutralized salts in the polymer molecular chain are preferably ammonium salts, more preferably 70 mol% or more, still more preferably 90 mol% or more, and most preferably all ammonium salts. Neutralized with A high proportion of the ammonium salt is preferable in terms of absorption capacity and adhesion to the substrate. In addition, the ratio of the ammonium salt in a water absorbing resin can be calculated by calculating | requiring the total amount of nitrogen atoms in a water absorbing resin. The total amount of nitrogen atoms in the water-absorbent resin can be determined by the Kjeldahl method.

  There is no particular problem with the shape of the water-absorbent resin, and examples thereof include spherical particulate powders, irregular particulate powders, short fiber shapes, long fiber shapes, and sheet shapes that are widely used in absorbent compositions. Spherical particulate powder or amorphous particulate powder is preferable, and the particle size is preferably 100 to 3000 μm, more preferably 300 to 2800 μm, still more preferably 500 to 2500 μm, and most preferably 700 to 1500 μm.

  Monomers constituting the water-absorbing resin include (meth) acrylic acid, ethacrylic acid, itaconic acid, maleic acid, crotonic acid, fumaric acid, sorbic acid, cinnamic acid, their anhydrides, and unsaturated carboxylic acids. A neutralized salt of a monomer is exemplified, and a neutralized salt of (meth) acrylic acid is preferably used. The type of the neutralized salt is preferably an alkali metal salt such as lithium, sodium or potassium, or a nitrogen-containing basic substance such as ammonia. Other monomers may be copolymerized, and unsaturated monomers that may be copolymerized include (meth) acrylic acid, ethacrylic acid, itaconic acid, maleic acid, crotonic acid, sorbic acid, cinnamic acid, Their anhydrides, vinyl sulfonic acid, allyl sulfonic acid, styrene sulfonic acid, vinyl toluene sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, 2- (meth) acryloylethane sulfonic acid, 2- ( Anionic unsaturated monomers such as (meth) acryloylpropane sulfonic acid, 2-hydroxylethyl acryloyl phosphate, 2-hydroxylethyl methacryloyl phosphate, phenyl-2-acryloyloxyethyl phosphate, vinyl phosphate, and salts thereof, acrylamide , Methacrylamide, N-eth (Meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate Nonionic hydrophilic group-containing unsaturated monomers such as methoxypolyethylene glycol (meth) acrylate, polyethylene glycol mono (meth) acrylate, N-vinylpyrrolidone, N-acryloylpiperidine, N-acryloylpyrrolidine, and methyl You may use the hydrophilic monomer which forms a water absorbing resin by hydrolysis of the functional group after superposition | polymerization like (meth) acrylate, ethyl (meth) acrylate, vinyl acetate. Examples of the hydrophobic monomer that can be used in combination include styrene, vinyl chloride, butadiene, isobutene, ethylene, propylene, stearyl (meth) acrylate, lauryl (meth) acrylate, and the like. More than one type can be added.

  A crosslinking agent may be allowed to coexist in the monomer. As the crosslinking agent, a method in which a condensation type crosslinking agent is used to react with a functional group in the resin to crosslink, a polymerizable crosslinking agent is used. A method of crosslinking by copolymerizing with an unsaturated monomer, a method of crosslinking by irradiating the resin with an electron beam or radiation, etc. are raised, preferably a method using condensation type crosslinking, most preferably a functional group of the resin This is a method in which a polymerizable crosslinking agent and an unsaturated monomer are copolymerized in the presence of a condensation type crosslinking agent that reacts with.

  As the condensation type crosslinking agent, ethylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, (poly) glycerin polyglycidyl ether, diglycerin polyglycidyl ether, glycidyl ether compounds such as propylene glycol diglycidyl ether; (poly) glycerin, (Poly) ethylene glycol, propylene glycol, 1,3-propanediol, polyoxyethylene glycol, triethylene glycol, tetraethylene glycol, diethanolamine, triethanolamine and other polyhydric alcohols; ethylenediamine, diethylenediamine, polyethyleneimine, hexa Polyvalent amines such as methylenediamine; multivalent ions such as zinc, calcium, magnesium, and aluminum Which may be used those crosslinking agents of two or more.

  Examples of unsaturated monomer polymerizable crosslinking agents include diethylene glycol diacrylate, N, N′-methylenebisacrylamide, polyethylene glycol diacrylate, polypropylene glycol diacrylate, trimethylolpropane diallyl ether, allyl glycidyl ether, and pentaerythritol triallyl. Examples include ether, pentaerythritol diacrylate monostearate, bisphenol diacrylate, isocyanuric acid diacrylate, tetraallyloxyethane, diallyloxyacetate, and the like. Two or more of these crosslinking agents may be used.

  The solvent of the monomer solution is not particularly limited as long as it has excellent solubility. Particularly preferred is water alone, but hydrophilic solvents such as ethanol, methanol, acetone and the like may be used alone or in combination. If necessary, a salt such as sodium chloride, a basic compound such as ammonia for pH control, or a suspending agent may be added during reverse phase suspension polymerization.

  The polymerization method of the unsaturated monomer is not particularly limited, and generally used methods such as (water) solution polymerization, reverse layer suspension polymerization, reverse phase emulsion polymerization, spray polymerization, and belt polymerization can be applied. The polymerization initiation method is not particularly limited, and polymerization with a radical polymerization initiator, polymerization by irradiation with radiation, electron beam, or ultraviolet polymerization with a photosensitizer can be performed. Examples of the initiator used for such radical polymerization include persulfates such as potassium persulfate, ammonium persulfate and sodium persulfate; hydrogen peroxide; organics such as cumene hydroperoxide, t-butyl hydroperoxide and peracetic acid. Examples thereof include known initiators such as oxide oxides. When an oxidizing radical polymerization initiator is used, a reducing agent such as L-ascorbic acid or Rongalite may be used in combination.

  It is preferable to perform a deoxygenation operation in the monomer solution in advance before the start of polymerization. As a specific method, there is a method of removing dissolved oxygen by bubbling with an inert gas for a sufficient time. In addition, it is preferable that the atmosphere in the reactor is replaced with an inert gas such as nitrogen or helium. The inside of the reactor may be any of reduced pressure, normal pressure, and increased pressure. The polymerization initiation temperature is usually preferably in the range of 0 to 70 ° C. More preferably, it is the range of 10-40 degreeC. If the starting temperature is too high, polymerization by heat occurs before the initiator is added, which is not preferable. On the other hand, if the starting temperature is too low, it takes too much time to start the reaction, which is not preferable. The temperature in the reactor during the reaction may depend on the outcome, and the temperature may be controlled by cooling or heating from the outside. The temperature rising rate and the maximum temperature during the polymerization are not particularly problematic, and there is no problem even if the maximum temperature exceeds 100 ° C. The maximum temperature during polymerization is usually 20 to 140 ° C, preferably 40 ° C to 120 ° C. The concentration of the monomer solution is preferably 10 to 70%, and most preferably 30 to 50%. If the concentration is too high, the reaction tends to run away, which is not preferable. If the concentration is too low, it takes too much time for the reaction, and the subsequent drying process is also burdened, which is not preferable. The polymerization time is preferably set in the vicinity of the time when heat generation from the reaction solution stops. Since there are heating processes such as a drying process and a post-crosslinking process as post-processes after the polymerization, the polymerization may be terminated before the heat generation from the reaction solution stops. Further, after completion of heat generation, it may be heated and kept for several hours.

  When the polymer obtained after the polymerization is a hydrogel, drying is performed. Although this drying method is not particularly limited, for example, azeotropic dehydration, fluidized drying, hot air drying, vacuum drying and the like are preferably used, and hot air drying and vacuum drying are particularly preferable. The moisture content is 30% by mass or less, preferably 10% by mass or less. Drying may be performed with any form of hydrogel, but it is preferable to dry after coarsely crushing to increase the surface area. The drying temperature is preferably in the range of 70 ° C to 180 ° C, particularly preferably 100 to 140 ° C.

  The particle size of the polymer after drying is adjusted by operations such as pulverization and classification as required. The shape may be various shapes such as spherical, scaly, irregularly crushed, and granular, but the weight average particle diameter is preferably 300 to 3000 μm, more preferably 500 to 2800 μm, and most preferably. Is 700-2500. If the particle size is too small, it becomes fine powder, and it becomes easy to scatter.

  In the polyacrylic acid crosslinked product, the polymer after drying controlled to a predetermined particle size may be heated. In the heat treatment, it is preferable that a compound having two or more functional groups capable of reacting with the carboxyl group to be used coexists. A compound having two or more functional groups capable of reacting with a carboxyl group may be added before polymerization, or may be added to particles before heat treatment. When put before heat processing, it is preferable to dissolve in hydrophilic solvents, such as water, alcohols, and ethers, and to spread on the surface. Although the temperature of heat processing is not specifically limited, Preferably it is the range of 120-250 degreeC. Preferably it is 150-240 degreeC, More preferably, it is 170-230 degreeC. The heat treatment may be performed continuously in the same apparatus after completion of drying, or may be a step independent of the drying step.

  For the above heat treatment, a normal dryer or a heating furnace can be used. For example, a groove type mixer / dryer, a rotary dryer, a disk dryer, a fluidized bed dryer, an airflow dryer, an infrared dryer, etc. Can be mentioned.

  In the water-absorbing resin thus obtained, if necessary, deodorants, fragrances, various inorganic powders, foaming agents, pigments, dyes, antibacterial agents, hydrophilic short fibers, plasticizers, adhesives, surfactants, Fertilizers, oxidizing agents, reducing agents, chelating agents, antioxidants, heat stabilizers, UV absorbers, light stabilizers, water, salts, etc. may be added.

  Examples of the inorganic powder include fine particles of various inorganic compounds that are inert to water and hydrophilic organic solvents, fine particles of clay mineral, and the like. In particular, the inorganic powder preferably has an appropriate affinity for water and is insoluble or hardly soluble in water, such as metal oxides such as silicon dioxide and titanium oxide, natural zeolite, synthetic zeolite, etc. Silicic acid (salt), kaolin, talc, clay, bentonite and the like.

  The usage-amount of the said inorganic powder is 0.001-10 weight part normally with respect to 100 weight part of water absorbing resin, Preferably it is 0.01-5 weight part. There is no restriction | limiting in particular in the mixing method of water absorbing resin and inorganic powder, It carries out by the dry blend method, the wet mixing method, etc.

  If necessary, the particle diameter of the water-absorbent resin is finally adjusted by operations such as grinding and classification. The shape may be various shapes such as spherical, scaly, irregularly crushed, and granular, but the weight average particle diameter is preferably 300 to 3000 μm, more preferably 500 to 2800 μm, and most preferably. Is 700-2500.

  The water-absorbing resin in the present invention is preferably polymerized until the residual monomer amount is 1% or less. When there are many residual monomers, the elution from an absorber will increase and it is unpreferable in performance. The water-absorbent resin as a starting material is preferably polymerized to a residual monomer content of 10% or less. If the amount of residual monomer is large, it is difficult to complete the polymerization on the nonwoven fabric, and a large amount of residual monomer tends to remain in the end, which is not preferable. The amount of residual monomer can be quantified using the following method. The water-absorbing resin cut to a size of 2 to 3 mm or less is added to 0.9% physiological saline, which is 250 times the weight of the resin, and extracted with stirring for about 6 hours, followed by filtration. The filtrate is quantified using a liquid chromatography method.

The water-absorbent resin before adhering to the substrate in the present invention preferably has a surface salt concentration of 50 mol% or more, more preferably 60 mol% or more, more preferably 70 mol%, most preferably the water-absorbent resin. It is 80 mol% or more. If the surface salt concentration before adhering onto the substrate is too low, the adhesion of the particles will be reduced. There is no particular limitation on the surface salt concentration of the water-absorbent resin portion in the composite after final adhesion to the substrate, but it is preferably 90 mol% or less, more preferably 80 mol% or less, and most preferably 60 mol% or less. is there. A lower surface salt concentration of the water-absorbent resin in the final composite is advantageous because it hardly causes stickiness even when exposed to moist air. The water-absorbent resin is usually composed of an acid group such as a carboxyl group or a sulfonic acid group and a neutralized salt thereof, a basic group such as an amino group and a neutralized salt thereof, and the surface salt concentration of the water-absorbent resin is: The ratio of the neutralized group of the surface part of a water absorbing resin is represented. In the present invention, the surface salt concentration of the resin is determined by measuring by a microscopic ATR method which is one of infrared absorption analysis methods. The neutralization rate of the resin surface can be directly measured by the microscopic ATR method. The internal portion is measured by a micro ATR method after cleaving the resin by using an ultramicrotome (ULTRACUT N manufactured by Reichert) to expose the central portion.
As a measuring device, FTS-575 manufactured by Bio-Rad is used.

Hereinafter, a polyacrylic acid water-absorbing resin will be described as an example. As an indicator for defining the composition ratio of carboxylic acid and carboxylate, 1,695 cm ^-1 (carboxylate νC = 0 Baseline 1774~1616cm ^-1) and 1558cm ^{-1 -} peak of (carboxylate νCOO baseline 1616~1500cm ^-1) An area ratio (1695/1558 cm ⁻¹ ) was calculated, and separately prepared by measuring and preparing 10 mol%, 30 mol%, 50 mol%, 70 mol%, 90 mol%, and 100 mol% partially neutralized polyacrylic acid neutralized with ammonia as a standard sample The composition ratio is obtained from the line.

The water absorbent resin in the present invention preferably has a surface strength of 0.1 to 5.5N, more preferably 0.1 to 5N, still more preferably 0.2 to 4N, and most preferably 0.2 to 3N. It is. The surface strength is a parameter representing the ease of deformation of the particle surface. When a water absorbent resin that has been absorbed and swollen at a specific magnification is put into a container and a load is applied, the gel moves and deforms so as to fill the gap of the water absorbent resin that is filled with a gap in the container. Go. Since the surface strength is an elastic modulus when the absorbed water-absorbing resin reaches an actual volume, it means the magnitude of interaction between gel particles and the ease of surface deformation. A high surface strength indicates that the water-absorbent resin is not easily deformed. The fact that it is difficult to deform means that the water-absorbing resin absorbs and swells, whereas the negative force is strong, and consequently the absorption capacity is lowered. Further, if the surface is not easily deformed, it is not preferable because the adhesion surface becomes small and particles are likely to be detached from the composite. The surface strength of the water absorbent resin of the present invention is determined as follows.
Equipment: Shimadzu Autograph AG-1
Sample: 0.10 g of water-absorbing resin was precisely weighed and placed uniformly in the bottom of a cylindrical container having an inner diameter of 20.5 mm and a height of 50 mm, with a nylon sheet having a pore diameter of 75 μm attached to the bottom surface. A 50φ petri dish was prepared, 0.90 g of physiological saline was added, and the cylindrical container containing the water-absorbent resin was left to stand for absorption and swelling for 1 hour.
Measurement: A 1 kN load cell was used, and a cylindrical shaft having a diameter of 19.7 mm was attached. The measurement range is set to 0.2 kN, and is set so that the load cell is lowered at a constant speed of 0.6 mm / min according to the height at which no load is applied to the load cell. The pressure applied to the load cell was recorded over time. Here, the surface strength represents the load (N) when the actual volume is reached. The actual volume of the water-absorbent resin was calculated using the specific gravity of physiological saline 1.010 g / cm ³ and the specific gravity of the water-absorbent resin.

The particle diameter of the water absorbent resin used in the present invention is preferably 100 to 3000 μm, more preferably 300 to 2800 μm, still more preferably 500 to 2500 μm, and most preferably 700 to 1500 μm. As used herein, the particle size refers to particles that pass through the upper limit interval sieve and remain on the adjustment interval sieve. In the water-absorbent resin of the present invention, the number of particles passing through a sieve having an opening of 300 μm is preferably 50% or less, more preferably 30% or less, still more preferably 20% or less, and most preferably 10% or less. is there. Particles that cannot pass through a sieve having an opening of 3000 μm are preferably 10% or less, more preferably 5% or less.
The average particle diameter in the present invention is preferably 300 to 3000 μm, more preferably 500 to 2500 μm, and most preferably 700 to 1500 μm. The average particle size is determined by sieving. The smaller the average particle size, the higher the absorption rate as particles. Moreover, the larger the average particle size, the larger the swelling in the direction perpendicular to the nonwoven fabric, and the higher the amount of absorption per area. In addition, when particles having the same weight are placed, it can be said that the larger the particle size, the lower the area filling rate of the resin and the less the swelling inhibition. If the particle size alone is too large, the absorption rate will be slow, but the particles in the composite of the present invention will significantly improve the absorption rate even with large particle size due to the composite effect with the fiber, It is also preferable to use relatively large particles.

  In the present invention, the non-pressurized absorption capacity of the water absorbent resin is preferably 55 g / g or more, more preferably 60 g / g or more, and most preferably 70 g / g or more. In the water-absorbent resin of the present invention, the absorption capacity under pressure of the water-absorbent resin at 0.8 psi is preferably 20 g / g or more, more preferably 25 g / g or more, and most preferably 30 g / g or more. . A higher absorption capacity of the water absorbent resin is preferable because the amount of the water absorbent resin to be used can be reduced.

  The non-pressurized absorption capacity of the water-absorbent resin of the present invention is an amount capable of freely swelling and absorbing 0.9% physiological saline in a state where no load is applied to the water-absorbent resin. The non-pressure absorption capacity of the water absorbent resin is measured by the following method.

0.05 g of water-absorbent resin is uniformly placed in a non-woven tea bag bag (60 × 40 mm) and immersed in 0.9% physiological saline at 23 ° C. After 180 minutes, the bag is taken out, the corner of the tea bag is fixed, suspended for 10 minutes in an oblique state, drained, and then weighed. The same operation is performed without using the water absorbent resin, and the weight is measured to obtain a blank. Absorption capacity is calculated according to (Equation 1). The measurement is performed three times, and the average value is defined as the non-pressurized absorption capacity of the water absorbent resin.
(Formula 1)
Absorption capacity of non-pressurized water absorbent resin (g / g) = {(weight of tea bag after absorption) − (weight of blank tea bag after absorption) − (weight of water absorbent resin)} / (absorption) Resin weight)
The absorption capacity under pressure of the water absorbent resin of the present invention is measured by the following method. Put 0.02 g of water-absorbing resin in an acrylic resin cylinder with an inner diameter of 25 mm, a height of 30 mm and a 250 mesh nylon nonwoven fabric at the bottom, and put a smoothly moving cylinder into the cylinder to make a measuring device and measure the weight. . A load of 278.33 g corresponding to 0.8 psi is placed on the upper part of the cylinder of the measuring device to obtain a load, which is placed in a petri dish with an inner diameter of 120 mm containing 60 g of 0.9% physiological saline. After 60 minutes, it is taken out and left on a Kim towel for 3 seconds to drain water, the weight of the device after removing the load is measured, and the absorption capacity under pressure is calculated according to (Equation 2).
(Formula 2)
Absorption capacity under load of water absorbent resin (g / g) = (weight of device after absorption (g) −weight of device before absorption (g)) / (weight of absorption resin)
(About resin ratio)
The resin ratio in the present invention indicates the ratio of the water-absorbing resin in the composite absorbent body, and is specifically determined as shown in (Formula 3).
(Formula 3)
Resin ratio (% by mass) = A / B × 100
However, the weight of the water absorbent resin in the composite is A (g), and the total weight of the composite is B (g).

It is essential that the resin ratio is 65% by mass or more and less than 99%, preferably 70% by mass or more and 99% by mass or less, and more preferably 80% by mass or more and 99% by mass or less. A higher resin ratio is preferable because the total absorption amount as a composite increases. The weight of the water-absorbent resin is measured with all particles removed.
(About resin area filling rate)
The resin area filling rate in the present invention is an index representing the ease of contact between particles when the water absorbent resin absorbs a liquid. In the present invention, the resin area filling rate is measured as follows.

A photograph of the surface of the composite is measured with an optical microscope or an electron microscope. At this time, the measurement condition and the magnification are selected so that the water-absorbent resin and the substrate can be distinguished, and a photograph can be taken with 10 or more water-absorbent resin particles in one photograph. The photograph is enlarged and copied, the water-absorbing resin portion and the base material portion are cut out, the weight is measured, and calculation is performed according to the following (Equation 4). 5 or more arbitrary points in the absorber are photographed, and the average value is defined as the area filling rate. In the case where the water-absorbent resin is adhered to both surfaces of the substrate, the measurement is performed separately on each surface.
(Formula 4)
Resin area filling rate (%) = weight of water-absorbing resin portion / total weight × 100
The resin area filling rate is preferably 1 to 30 (%), more preferably 2 to 25, and still more preferably 3 to 20. If the area filling rate is too high, the water-absorbing resins come into contact with each other when the water-absorbing resins swell, blocking occurs, and the ability of the water-absorbing resin cannot be fully exhibited. Moreover, when the resin area filling rate is too low, the amount of absorption per area in the composite absorbent body is reduced, which is not preferable.
(About adhesion)
In the present invention, the adhesion between the base material and the water absorbent resin means that the water absorbent resin is fixed to the base material and the positional relationship between the base material and the water absorbent resin does not substantially change. In the present invention, the end of the absorber is held and fixed by hand, the surface where the adhesive particles are present is faced down, and the particles that are not detached are bonded by shaking at a speed of 2 reciprocations per second for 2 seconds at a width of 20 cm. Suppose you are. The ratio of the adhered particles can be determined by measuring the weight of the detached particles and the force by peeling off the adhered particles with forceps. If the positional relationship between the base material and the water-absorbent resin does not change, the performance of the absorber does not change due to transportation before use or the like, which is preferable from the viewpoint of repeated liquid absorption. In the present invention, it is essential that 50% or more of the water-absorbing resin is adhered, preferably 70% or more, more preferably 90% or more, and most preferably 99% or more. In the present invention, there is no particular limitation on the form of adhesion to all particles, adhesion by an adhesive, adhesion by a chemical bond between a substrate and a water absorbent resin, adhesion by a physical interaction, and fibers have entered the water absorbent resin. Although adhesion in a form or the like may be sufficient, it is preferable that 50% or more of the water-absorbent resin is bonded in a form in which fibers are taken into the water-absorbent resin. Preferably 60% or more, more preferably 70% or more, and most preferably 90% or more of the water-absorbing resin adheres in this form. Use of an adhesive is not preferable because it may inhibit swelling of the water absorbent resin. Examples of the adhesive include thermoplastic fibers and polymers, emulsion binders, and hot melt adhesives. The form in which the fibers are contained in the water absorbent resin represents a state in which the fibers in the substrate are present in the water absorbent resin matrix. The shape and length of the fibers that enter are not particularly limited. When bonded in this form, water can be taken into the water-absorbent resin through the fiber, so that excellent performance is exhibited in terms of absorption amount and absorption speed. It can be confirmed with an electron microscope whether or not the fibers are bonded in the form of entering the water-absorbent resin. Any 30 adhered particles can be extracted, peeled off, and observed with an electron microscope to determine the ratio.

The arrangement of the bonded water-absorbing resin is not particularly problematic as long as the above-mentioned resin area filling rate is satisfied, but the water-absorbing resin is arranged and bonded so that it does not come into contact when absorbing the assumed liquid amount. And, a water-absorbent resin is preferable because it easily exhibits absorption performance. Further, the water-absorbing resin may be adhered to only one surface of the substrate, or may be adhered to both surfaces of the substrate. Adhering to both sides is preferable because the amount of absorption per area increases.
(About manufacturing method of composite)
The production method of the absorbent composite in the present invention may be any method, but a production method comprising a step of adhering the water-absorbent resin to the substrate using the water-absorbent resin and the substrate as raw materials is preferable. The bonding method is not particularly limited, and a bonding method that satisfies the above-described conditions may be performed. Examples of the bonding method include a method in which a water-absorbing resin is entangled in a substrate and a method in which an adhesive is used. A preferable method is that 10 to 3000 parts by weight of water is added to 100 parts by weight of the water-absorbing resin. In this method, the water-absorbent resin and / or the base material is absorbed and then dehydrated from the state where the water-absorbent resin and the base material are in contact with each other. The amount of water is preferably 20 to 2000 parts by weight and more preferably 50 to 1000 parts by weight with respect to 100 parts by weight of the water absorbent resin. Adhesion by this method is preferable because it is not necessary to use an adhesive as an impurity. Moreover, since adhesion | attachment is carried out by this method, since a part of fiber is taken in into a water absorbing resin, it is preferable at the point of an absorption speed or an absorptive power. The larger the amount of water, the higher the adhesiveness and the better. However, if the amount is too high, drying takes too much time, which is inefficient.

  The water to be hydrated may contain impurities. Examples of the impurities include cations such as sodium ion, ammonium ion and iron ion, anions such as chlorine ion, water-soluble organic compounds such as acetone, alcohols, ethers and amines. In order to adjust the pH of the water-absorbent resin and / or the absorbent composite, an acidic or basic one may be used. Considering the contact between the water-absorbent resin and the nonwoven fabric and the absorption capacity, it is preferable to use distilled water or ion-exchanged water free from these impurities alone.

  Either one or both of the water-absorbing resin and the substrate may be in a water-containing state, or both may be in a dry state. If water-absorbing resin is contained in water, it will be easy to stick to parts other than the base material, so the water-absorbing resin before contact is dry to the extent that there is no adhesion to other substances or adhesion between particles preferable. Examples of the contact method include a method of spraying a water-absorbing resin from the top onto a substrate, a method of discharging and contacting the water-absorbing resin scraped with a drum with pressure, and filling a drum roll with the water-absorbing resin. For example, a method of discharging and contacting with pressure may be used. A method in which the water-absorbing resins can be arranged so that they do not come into contact with each other when the water-absorbing resin swells is preferable because the performance of the water-absorbing resin is easily exhibited without waste.

Any method of dehydration may be used. Examples of the method include drying by heating, a method of spraying dry air or nitrogen, vacuum drying, freeze drying, azeotropic dehydration, fluidized drying, and microwave, and drying by heating is preferable. The heating condition is preferably 70 to 350 ° C. for 1 second to 1000 seconds, more preferably 100 to 340 ° C. for 1 second to 1000 seconds, and still more preferably 120 to 330 ° C. for 1 second to 1000 seconds. Most preferably, it is 150 to 300 ° C. for 1 to 1000 seconds. The higher the temperature, the shorter the drying time is. However, when the heating is performed for a long time at a high temperature, the absorption performance may be lowered depending on the type of the resin. Simultaneously with the drying, a surface treatment such as surface crosslinking may be performed. The dehydration may be performed at any time until the final product is obtained, but it is preferable to perform the dehydration promptly after hydration from the viewpoint of deterioration of the water absorbent resin.

(Composite performance)
-About the non-pressure absorption capacity | capacitance of a composite_body | complex The non-pressure absorption capacity | capacitance of the composite_body | complex of this invention shall be the quantity absorbed after 3 hours, when 0.9% physiological saline was made to absorb freely. Specifically, a circular composite absorbent body having a diameter of 59.5 mm is prepared, and measurement is performed using the same method as the above-described absorption rate of the nonwoven fabric. However, if it contains a non-adhered water-absorbing resin, or if detachment occurs, collect the water-absorbing resin by filtration, leave it on the Kimwipe for 10 seconds or more, drain it, The weight will be added to the calculation. Moreover, in the case of the absorber which is not fixed at all, it measures by putting an absorber in T-Bag according to the measuring method of the absorption capacity of a water absorbent resin. If the T-Bag does not fit, the measurement may be performed in multiple steps. When the entirety has the same absorber structure, a part is extracted and measured, and this can be regarded as the absorption capacity of the absorber. In the present invention, the whole is the same when the value when extracted and measured five times is ± 1 g or less.

The non-pressure absorption capacity of the composite is preferably 40 g / g or more, more preferably 45 g / g or more, still more preferably 50 g / g or more, and most preferably 60 g / g or more.

As an index of the absorption performance of the composite, the amount of absorption per area is important. The amount of absorption per area can be calculated according to (Equation 5) from the above measurement results.
(Formula 5)
Non-pressure absorption per area (g / cm ² ) = ((total weight after absorption (g) −weight of composite (g)) / area of composite (cm ² )
No pressurized intake yield per area is preferably from 0.4 g / cm ^2, more preferably 0.7 g / cm ² or more, and most preferably 1 g / cm ² or more.
-Absorption capacity under pressure of the complex The absorption capacity under pressure of the complex of the present invention is expressed by the amount absorbed after 3 hours when 0.9% physiological saline is absorbed in a loaded state. The Specifically, the measurement is performed as follows using a circular composite having a diameter of 59.5 mm.

First, the measurement apparatus will be briefly described below with reference to FIG. As shown in FIG. 1, the measuring apparatus includes a balance 1, a container 2 having a predetermined capacity placed on the balance 1, an outside air intake pipe 3, a conduit 4, a glass filter 6, and the glass filter 6. It consists of the measurement part 5 mounted on the top. The container 2 has an opening 2a at the top and an opening 2b at the side, and the outside air intake pipe 3 is fitted into the opening 2a, while the conduit 4 is attached to the opening 2b. It has been. The container 2 contains a predetermined amount of physiological saline 12. The lower end of the outside air intake pipe 3 is submerged in the physiological saline 12. The glass filter 6 is formed with a diameter of 70 mm. The container 2 and the glass filter 6 are communicated with each other by a conduit 4. Further, the glass filter 6 is adjusted to be the same height as the lower end of the outside air intake pipe 3. As shown in FIG. 2, the measurement unit 5 includes a filter paper 7 and a support cylinder 9 weight 11. As the filter paper 7, Advantech No. 2 having a diameter of 60 mm is used. The measuring unit 5 includes a filter paper 7 and a support cylinder 9 placed in this order on a glass filter 6, and a weight 11 is placed inside the support cylinder 9. The support cylinder 9 has an inner diameter of 60 mm. The weight of the weight 11 is adjusted so that a load of 0.8 psi can be uniformly applied to the absorber. The absorption capacity under pressure of the composite was measured using the measuring apparatus having the above configuration. The measurement method will be described below. First, predetermined preparatory operations such as putting a predetermined amount of physiological saline 12 into the container 2 and fitting the outside air suction pipe 3 into the container 2 were performed. Next, the filter paper 7 was placed on the glass filter 6. On the other hand, in parallel with these placement operations, an absorber was placed inside the support cylinder 9 and a weight 11 was placed on the absorber. Next, the support cylinder 9 was placed such that the center portion thereof coincided with the center portion of the glass filter 6. Then, the weight W (g) of the physiological saline 12 absorbed by the water absorbent resin every 10 seconds from the time when the support cylinder 9 was placed was measured using the balance 1. The absorption capacity under pressure of the composite is determined according to (Equation 6).
(Formula 6)
Absorption capacity under pressure of composite (g / g) = weight W (g) / weight of composite (g)
The absorption capacity under load under 0.8 psi load of the composite is preferably 15 g / g or more, more preferably 16 g / g or more, and most preferably 18 g / g or more. Even under pressure, the amount of absorption per area can be determined as in the case of no pressure. Absorption amount per area in 0.8psi pressure is preferably from 0.1 g / cm ^2, more preferably 0.15 g / cm ² or more, most preferably 0.2 g / cm ² or more.

(About adhesive)
In the present invention, the absorbent composite and the liquid-permeable sheet and / or liquid-impermeable sheet are preferably fixed with an adhesive. The absorbent composite is excellent in form stability, but by fixing with an adhesive, it is possible to prevent the absorber from being twisted or displaced and to exhibit the absorption performance stably. The absorbent composite and the liquid-permeable sheet and / or liquid-impervious sheet are preferably directly bonded, but another sheet-like substance is interposed between the sheet-like substance and the absorbent composite and the sheet. The liquid substance and the liquid-permeable sheet and / or liquid-impermeable sheet may be adhered. In addition, the sheet-shaped substance is bonded to the liquid-permeable sheet and / or liquid-impermeable sheet in a state in which the absorbent complex is included in the sheet-shaped substance and the movement of the absorbent complex in the sheet-shaped substance is restricted. You may let them. In order to reliably prevent twisting and shifting, it is preferable that the absorbent composite and at least the liquid-permeable sheet or liquid-impermeable sheet are directly bonded.

  The adhesive in the present invention refers to an adhesive capable of adhering the absorbent composite and other substances. The property of the adhesive is not particularly limited, and may be liquid or solid. Only one type of adhesive may be used, or a plurality of adhesives may be used in combination. The type of the adhesive is not particularly limited, and examples thereof include solvent-based, water-dispersed, hot-melt, and reaction systems. Specific examples include urea resin-based adhesives, melamine resin-based adhesives, and phenol resins. Adhesive, resorcin adhesive, α-olefin adhesive, water-soluble polymer-isocyanate adhesive, vinyl acetate resin emulsion adhesive, acrylic emulsion adhesive, vinyl acetate resin adhesive, chloroprene rubber adhesive Agent, nitrile rubber adhesive, SBR adhesive, natural rubber adhesive, epoxy resin adhesive, cyanoacrylate adhesive, polyurethane adhesive, acrylic resin adhesive, anaerobic adhesive, modified silicone type Examples thereof include an adhesive, an inorganic adhesive, and a paste. When a hydrophilic adhesive is used, it is easy to diffuse and it becomes difficult to control the adhesive surface. Therefore, a hydrophobic adhesive is preferable. It is preferable to use a hot melt adhesive because of the ease of the manufacturing process. Hot-melt adhesive refers to all adhesives that are solid at room temperature but are heated and melted, and solidify and adhere when cooled. Specifically, for example, ethylene vinyl acetate copolymer resin, polyamide, polyester, Examples thereof include those containing atactic polypropylene, thermoplastic elastomer and the like as main components and rosin resin, petroleum resin, etc. as tackifiers, and waxes, antioxidants, inorganic fillers, plasticizers and the like.

In the present invention, the amount of the adhesive is not a problem as long as the absorbent composite adheres to the liquid-permeable sheet and / or liquid-impermeable sheet. The amount of adhesive per unit length is preferably 0.000001 to 0.1 g / cm, more preferably 0.00001 to 0.01 g / cm, and 0.00003 to 0.0045 g / cm. Is more preferable. To the area of the absorbent composite, the coating amount of the adhesive is preferably 0.2~1000g / ^{m 2,} and still more preferably from 2.0~100g / ^{m 2.} If the amount of the adhesive is too large, the swelling of the water-absorbent resin is inhibited, the absorption performance is lowered, and the texture is impaired, which is not preferable. Moreover, even if there is too little adhesive agent, it is unpreferable from the point of adhesive strength. The adhesive pattern in the present invention may be a general coating method such as a wavy bent line, dot, or vertical stripe.
(Performance evaluation of body fluid absorbent articles)
・ Evaluation of returnability and liquid diffusion length On a wooden board with a sufficient area, the body fluid absorbent article is fixed with a thumbtack with the four corners of the article being stretched so that the article does not wrinkle. A cylindrical pipe having a diameter of 60 mm and a weight of 53.5 g is installed at the center of the absorber. 80 g of physiological saline warmed to 37 ° C. is weighed and added dropwise to the central portion of the absorber at a rate of 7 to 8 ml / second. After confirming that physiological saline is no longer visible on the upper surface of the top sheet, remove the cylinder. Three minutes after the start of dropping, the length of the diffusion in the vertical direction is measured and this is defined as the liquid diffusion length. Five minutes after the start of dropping the droplet, Advantech No. 2 filter paper with a diameter of 150 mm was cut into a square with a side of 10 cm so as to be approximately 90 g and placed at the bottom of the droplet. Apply a load of 5 kg. Three minutes after applying the load, the load is removed, the filter paper is removed from the article, and the weight is measured. At this time, the weight increased from the weight of the original filter paper is taken as the first return amount.

  Place the cylinder again 9 minutes after the drop. After 10 minutes from the bottom of the droplet, 80 g is dropped again and the same operation as the first time is repeated. The increase in the weight of the filter paper at this time is taken as the second return amount.

  A cylinder is installed 19 minutes after the first droplet, 80 g is dropped again 20 minutes after the first droplet, and the same operation is repeated. The increase in the weight of the filter paper at this time is taken as the third return amount.

  The return amount is an index representing the feeling of use when the body fluid absorbent article is used. If the amount of return is large, the skin gets wet and the attachment is uncomfortable. It can be said that the smaller the return amount, the better because the surface of the article dries and becomes comfortable. Furthermore, the amount of return when the number of times is repeated represents the feeling of use when the body fluid absorbent article is continuously worn and the body fluid is repeatedly absorbed, and the second and third times the amount of return is reduced, the wear is continued. This is also preferable because it shows an excellent wearing feeling. The first return amount is preferably 15 g or less, more preferably 10 g or less, further preferably 5 g or less, and most preferably 1 g or less. The amount of the second return is preferably 30 g or less, more preferably 20 g or less, further preferably 15 g or less, and most preferably 8 g or less. The third return amount is preferably 40 g or less, more preferably 32 g or less, further preferably 25 g or less, and most preferably 20 g or less.

  The liquid diffusion length represents the length used for absorbing the liquid in the absorber, and it can be said that the longer the liquid diffusion length, the higher the utilization efficiency of the absorber. If the utilization efficiency of the absorbent body is high, it is possible to save resources of the absorbent article. Moreover, since the thickness of the absorption layer after liquid absorption will become thin when the liquid diffusion length is long, it is difficult for the absorber to be displaced and the wearer's wearing feeling is reduced, which is preferable. The liquid diffusion length is preferably 200 mm or more, more preferably 215 mm or more, further preferably 230 mm or more, and most preferably 250 mm or more.

  A body fluid absorbent article composed of a liquid permeable sheet, a liquid impermeable sheet, and an absorbent composite interposed therebetween, wherein the absorbent composite is composed of a base material and a water absorbent resin. A bodily fluid absorbent article having a resin ratio of 65% by mass to 99% by mass with respect to the weight of the absorbent composite and a liquid diffusion length of 200 mm or less is an article that has good returnability and is comfortable to use. It can be said. The reason for this is that if the liquid diffusion length is long, the amount of liquid present per area is small, so that it can be absorbed quickly, and the absorber with a high resin ratio has high absorbency and liquid such as fibers. This is because the amount of liquid absorbed by the returning member is small.

  It is comprised from the base material and the water absorbing resin, and the absorptive composite body is a sheet form, the form is stable, and can diffuse a liquid through a base material. If the substrate is hydrophilic, it is preferable that the liquid easily passes through the substrate. It is more preferable that the suction absorption capacity of the substrate is high because the ability to suck through the inside of the substrate is high. Even if the amount of liquid passing through the inside of the substrate is small, it can be diffused between the substrate and the liquid-permeable sheet or liquid-impermeable sheet by capillary action. At this time, if the water-absorbing resin swells without a gap, the passage of the liquid becomes narrow and the diffusibility deteriorates. Therefore, the area filling rate is preferably set to 1 to 30% so that the water-absorbing resins do not contact each other. Thus, the liquid diffusion length can be set to 200 mm or more by setting the relationship between the base material and the water-absorbent resin to a specific condition. Especially, if a base material is an absorptive composite which is cloth and / or paper, diffusibility is favorable, and higher diffusibility can be exhibited by using a cellulosic base material.

The area weight of the absorbent composite is an index representing the thickness and weight of the absorbent. The larger the area weight, the higher the absorption capacity per area. However, a large area weight is not preferable because the thickness of the absorber is increased and the weight is increased. The area weight is preferably as small as possible in a range where there is no problem in the absorption capacity. Preferably the area weight is 0.05 g / cm ² or less, more preferably 0.04 g / cm ² or less, further preferably 0.03 g / cm ² or less, 0.02 g / cm @ 2 or less Most preferably. The non-pressure absorption capacity of the composite is preferably 40 g / g or more, more preferably 45 g / g or more, still more preferably 50 g / g or more, and most preferably 60 g / g or more. A higher absorption ratio is preferable because even if the area weight is small, an absorption amount per high area can be provided. When the area weight is 0.05 g / cm ² or less and the non-pressure absorption capacity is 40 g / g or more, the absorbent body has a high absorption capacity per area while being thin and light. The absorption amount per area is preferably from 0.4 g / cm ^2, more preferably 0.7 g / cm ² or more, and most preferably 1 g / cm ² or more. Use of an absorbent composite having a weight per area of 0.05 g / cm 2 or less, a non-pressurized absorption capacity of 40 g / g or more, and a body fluid-absorbing article having a liquid diffusion length of 200 mm or more is particularly thin and lightweight. Therefore, it is possible to provide a bodily fluid absorbent article excellent in returnability.

An absorbent composite having an area weight of 0.05 g / cm ² or less and a non-pressure absorption capacity of 40 g / g or more can absorb a water-absorbing resin having a high non-pressure absorption capacity and swell the water-absorbing resin. It can be obtained by arranging in an unhindered state.

  If the surface strength of the water-absorbent resin is lowered, the surface of the water-absorbent resin is easily deformed at the time of liquid absorption, so that it is possible to obtain a water-absorbent resin that easily swells and has a high water absorption ratio. The surface strength is preferably 0.1 N or more and 5.5 N or less. The water absorption capacity of the water absorbent resin is also affected by the structure of the water absorbent resin and is a resin having a carboxylic acid group in the side chain, and more than 50% of the acid groups in the water absorbent resin are in the form of ammonium salts. If it is a neutralized polyacrylate copolymer, it is possible to obtain a water-absorbent resin that satisfies both the water absorption rate and the water absorption rate. The non-pressurized absorption capacity of the water absorbent resin is preferably 55 g / g or more, more preferably 63 g / g or more, still more preferably 70 g / g or more, and 80 g / g or more. Is most preferred.

  The water-absorbing resin preferably has a particle shape from the viewpoint of the water absorption speed, but in order to stably exhibit the water-absorbing performance, 50% or more of the total water-absorbing resin particles adhere to the substrate. It can be said that it is preferable. It is preferable that the water-absorbing resin is bonded to the base material without an adhesive because the liquid transfer from the base material to the water-absorbing resin is not hindered. Furthermore, when 50% or more of the particles are bonded in a form in which a part of the fiber of the base material is taken into the water-absorbent resin particles, it becomes a water passage for sending liquid to the water-absorbent resin and quickly exhibits the absorption capacity. In addition, the water-absorbent resin can absorb and take away the liquid absorbed in the fibers that are easily returned, which is preferable because the returnability is improved.

Specific examples and comparative examples of the present invention are shown below, but the present invention is not limited to the following examples.
Production Example 1

Acrylic acid was manufactured by Wako Pure Chemical Industries, Ltd. and was used after being purified by distillation. 100 g of reagent acrylic acid was dissolved in 91.02 g of water. The aqueous solution was cooled in an ice bath, and while maintaining the liquid temperature at 30 ° C. or lower, 117.94 g of a 25% by mass ammonia aqueous solution was gradually added with stirring to obtain a 40% by mass ammonium acrylate aqueous solution (neutralization rate). 100%).
90 g of this 40 mass% ammonium acrylate aqueous solution and 0.0187 g of N, N′-methylenebisacrylamide are added to a 300 ml separable flask. The flask is bathed in a water bath so that the liquid temperature is maintained at 30 ° C. The aqueous solution was deaerated by bubbling with nitrogen gas, and the reaction system was purged with nitrogen. Next, 0.43 g of 42 mass% glycerin aqueous solution was added with a syringe, and after stirring well, 0.0917 g of 30 mass% hydrogen peroxide aqueous solution and 0.0415 g of Rongalite each dissolved in 1 g of water were added to initiate polymerization. The internal temperature starts from 30 ° C and rises to 100 ° C in 5 minutes from the start of the reaction. Then, it heats in a water bath for 3 hours so that internal temperature may be maintained at 70 degreeC. Thereafter, the gel is taken out from the Separa flask and roughly crushed, and then dried at 100 ° C. for 4 hours using an inert oven. After drying, the mixture is pulverized with a homogenizer and sieved to 300 μm or less, 300 to 500 μm, 500 to 600 μm, 600 to 710 μm, 710 to 850 μm, 850 to 1200 μm, 1200 to 1400 μm, 1400 to 1700 μm, 1700 to 2500 μm, 2500 Classification to ˜3000 μm, 3000 μm or more. This is designated as water absorbent resin 1. The surface strength of this resin was 0.5N. The surface salt concentration was 90%.

Particles of 850 μm to 1200 μm were taken out, heated at 180 ° C. using an inert oven for 10 minutes, and the water absorption capacity was measured. As a result, it was 88 g / g under no pressure and 38 g / g under pressure.
Production Example 2

To a 300 ml flask, 81.73 g of reagent acrylic acid (manufactured by Wako Pure Chemical, special grade reagent), 185.71 g of water, and 31.78 g of sodium hydroxide were slowly added while cooling with ice so that the liquid temperature did not exceed 30 ° C. (Salt concentration 70%). 90 g of this monomer solution and 0.0561 g of N, N′-methylenebisacrylamide are added to a 300 ml separable flask. The flask is bathed in a water bath so that the liquid temperature is maintained at 30 ° C. The aqueous solution was deoxygenated by bubbling with nitrogen gas, and the reaction system was purged with nitrogen. Polymerization is started by adding 0.0826 g of 30% by mass dissolved in 1 g of water and 0.0518 g of Rongalite respectively. The internal temperature starts from 30 ° C and increases to 70 ° C in 10 minutes from the start of the reaction. Heat in a water bath for 3 hours so that the internal temperature is maintained at 75 ° C. 5 minutes after recording the maximum temperature. After a predetermined time has elapsed, the gel is taken out from the separable flask and roughly crushed, and then dried at 100 ° C. using an inert oven for 4 hours. After drying, the mixture is pulverized with a homogenizer and sieved to 300 μm or less, 300 to 500 μm, 500 to 600 μm, 600 to 710 μm, 710 to 850 μm, 850 to 1200 μm, 1200 to 1400 μm, 1400 to 1700 μm, 1700 to 2500 μm, 2500 Classification to ˜3000 μm, 3000 μm or more. This is designated as water absorbent resin 3. The surface strength of this resin was 0.9N.

Particles of 850 μm to 1200 μm were taken out, heated at 180 ° C. using an inert oven for 10 minutes, and the water absorption capacity was measured. As a result, it was 61 g / g under no pressure and 26 g / g under pressure.
Production Example 3

A mixed solution of 0.6 g of isopropyl alcohol, 0.02 g of glycerin, and 0.06 g of water was made and sprayed uniformly on 2 g of the water absorbent resin produced in Production Example 2. This was heated at 180 ° C. for 10 minutes using an inert oven. This is designated as water absorbent resin 4. The surface strength of this resin was 5.9N.

Particles of 850 μm to 1200 μm were taken out, heated at 180 ° C. using an inert oven for 10 minutes, and the water absorption capacity was measured. As a result, it was 54 g / g under no pressure and 22 g / g under pressure.
Example 1

“Benlyse” registered trademark manufactured by Asahi Kasei Fibers Co., Ltd. was cut into a rectangle of 33 cm in the longitudinal direction and 17 cm in the lateral direction. Benrise is a continuous long-fiber non-woven fabric made of 100% cellulose. It is a cellulosic unemployed fabric and has excellent water absorption characteristics. Moreover, since it is a continuous long fiber, it has sufficient strength when it contains water, and it has excellent liquid diffusibility. The basis weight of Benlyse used here was 27.5 g / cm 2. The properties of Benize are shown in Table 1.

An apparatus as shown in FIG. 4 is assembled to produce an absorbent composite. 4A is a flat plate made of polyvinyl chloride as shown in FIG. 5, and has holes as shown in FIG. Suction from the bottom B using a pump to make a slight vacuum. Of the water-absorbent resin 1 synthesized in Production Example 1 from the top of the flat plate, a component having a particle size of 850 to 1200 μm is sprinkled. Part C of FIG. 4 can be partially opened as necessary, and the degree of pressure reduction can be adjusted, and is adjusted as needed so that the pressure does not become so low that the plate bends. After filling the particles so that all the holes in the flat plate are filled, air is blown to blow away the particles that have entered the double layer and the extra particles that have not entered the hole. 7 g of distilled water is evenly applied to the Benize using a spray, and the Benize is placed on a flat plate. A polyethylene sheet having the same size as the flat plate is allowed to stand on the Benize and a glass plate is further allowed to stand on it. The flat plate and glass plate are turned over at the same time, air is blown from behind the flat plate, and the particles are discharged from the holes. Then gently remove the flat plate. At this point, the absorbent resin is adhered to Benize. This operation is repeated to transfer the particles to the back surface of the Benize. Finally, 7 g of distilled water is evenly applied by spraying, and only Benlyse is dried at 180 ° C. for 10 minutes using an inert oven. At this time, the four corners are held by weights so that the Benlyse does not shrink. After drying, the water-absorbent resin was firmly adhered to Benize and the adhesion rate was 99.8%. Unicharm's “Mooney Blue Fit M Size” registered trademark was prepared, and only the top sheet and the back sheet were recovered by dissolving the hot melt adhesive by the heat of the dryer. The manufactured absorbent composite is sandwiched between them, and the top sheet and the back sheet that are not in contact with the absorber are bonded to each other with the adhesive, non-corrosion quick-drying adhesive seal material TSE397 made by GE Toshiba Silicone Co., Ltd. Thus, a body fluid absorbent article was produced. This is Example 1.
Example 2

Absorbing body fluid in the same way as in Example, except that TSE397, a non-corrosive quick-drying adhesive sealant made by GE Toshiba Silicone Co., Ltd., is used to bond the composite absorbent body and the water-permeable sheet in the pattern shown in FIG. Articles were made. This is Example 2.
Example 3

A bodily fluid absorbent article was produced in the same manner as in Example 2 except that the composite absorbent body and the water-impermeable sheet were bonded. This is Example 3.
Example 4

A bodily fluid absorbent article was prepared in the same manner as in Example 2 except that the composite absorbent body and the water-permeable sheet, and the composite absorbent body and the water-impermeable sheet were bonded to each other. This is Example 4.
Example 5

A bodily fluid absorbent article was prepared in the same manner as in Example 1 except that Toyo Corporation's Pearson soft single toilet paper was placed above and below the absorbent composite. This is Example 5.
Example 6

Spunbond Eltas (registered trademark) polypropylene P03020 manufactured by Asahi Kasei Fibers Co., Ltd. is cut into a length of 33 cm and a width of 36 cm, and the absorbent composite is wrapped as shown in FIG. The sealant TSE397 was used for adhesion. A bodily fluid absorbent article was produced in the same manner as in Example 4 except that this absorber was used. This is Example 6.
Example 7

A bodily fluid absorbent article was produced in the same manner as in Example 4 except that 6225 for cooperative adhesive Scotch registered trademark plastic manufactured by Sumitomo 3M Limited was used as an adhesive. This is Example 7.
Example 8

A bodily fluid absorbent article was prepared in the same manner as in Example 4 except that water repellent hot melt adhesive manufactured by NSC Japan and ME117 were used as the adhesive. This is Example 8.
Example 9

“Benlyse” registered trademark manufactured by Asahi Kasei Fibers Co., Ltd. was cut into a rectangle of 40 cm in the longitudinal direction and 29 cm in the lateral direction. The basis weight of Benlyse used here was 27.5 g / cm 2.

A Teflon (registered trademark) sheet having a length of 40 cm and a width of 29 cm is placed on a glass plate having a length of 45 cm and a width of 35 cm, and among the water-absorbent resins synthesized in Production Example 1, a component having a particle size of 850 to 1200 μm is placed thereon. 4.2 g was measured and dispersed so as to be as uniform as possible. Two sets of this were prepared. First, Benrise was allowed to stand on the prepared set, and after spraying 10 g of water with a spray, another glass plate was allowed to stand on the Benrise for 1 minute. After that, remove the glass plate, hold the Benlyse with the Teflon (registered trademark) sheet and the particles adhered, and face the surface where the particles are not adhered, and spray the water absorbent resin on the Teflon (registered trademark) sheet. I left it on top. A glass plate was again placed thereon and allowed to stand for 1 minute. Take a glass plate and a Teflon (registered trademark) sheet, spray 10 g of water again by spraying, and then dry at 180 ° C. for 10 minutes using an inert oven. At this time, weights are placed and fixed only at the four corners of Benize. After drying, the Benize was shrunk to a length of 35 cm and a width of 22 cm. A body fluid absorbent article was produced in the same manner as in Example 1 using an absorbent composite cut into a length of 33 cm and a width of 11 cm. This is Example 9.
Example 10

A bodily fluid absorbent article was produced in the same manner as in Example 9, except that two absorbent composites were used. This is Example 10.
Example 11

A body fluid absorbent article was prepared in the same manner as in Example 1 except that the water absorbent resin 2 of Production Example 2 was used. This is Example 11.
Example 12

A body fluid absorbent article was prepared in the same manner as in Example 1 except that the water absorbent resin 3 of Production Example 3 was used. This is Example 12.
Example 13

Spunbond Ertas (registered trademark) polypropylene P03020 manufactured by Asahi Kasei Fibers Co., Ltd. was cut in a vertical direction of 33 cm and a horizontal direction of 17 cm. The weight was 1.1 g. A component having a particle size of 850 to 1200 μm was taken out of the water-absorbent resin 1 of Production Example 1 and heated at 180 ° C. for 10 minutes in an inert oven. A power split stick made by KOKUYO Co., Ltd. was thinly coated on one side of the non-woven fabric, and 5 g of water absorbent resin was uniformly dispersed. The inside was turned upside down, and 5 g of the water-absorbing resin was uniformly sprayed on the back side. Using this absorbent body, a body fluid absorbent article was produced in the same manner as in Example 1. This is Example 14.
Comparative Example 1

A bodily fluid absorbent article was produced in the same manner as in Example 9 except that 2.3 g of the water-absorbing resin to be dispersed was used. This is referred to as Comparative Example 1.
Comparative Example 2

A bodily fluid absorbent article was produced in the same manner as in Example 9 except that water was not sprayed. Even after heating in the oven, the Benlyse and the particles were hardly adhered, so that when the article was made vertical, the particles were biased, and a portion where no water-absorbing resin was present was formed. This is referred to as Comparative Example 2.
Comparative Example 3

An article was produced in the same manner as in Example 9 except that the absorbent composite was wound three times while being folded back by 17 cm in the lateral direction with a Benise of 33 cm in length and 102 cm in width. This is referred to as Comparative Example 3.
Comparative Example 4

A bodily fluid absorbent article was produced in the same manner as in Example 9 except that 7 g of particles having a size of 300 μm or less of the water-absorbent resin of Production Example 1 were adhered to only one side of Benlyse. This is referred to as Comparative Example 4.
Comparative Example 5

The M size of Mooney's Blue Fit (registered trademark) manufactured by Unicharm Corporation is referred to as Comparative Example 5.
Comparative Example 6

The M size of Pampers Cotton Care (registered trademark) manufactured by P & G Corporation is referred to as Comparative Example 6.

吸収体のずれ、よれ偏りは体液吸収物品を手で振ったときの状態変化を目視で確認した。
◎全く変化なし。○吸収体構造は変化しない。荷重条件によっては一部ずれが生じる
△吸収体内部構造が変化。×完全に動く

Absorption and twisting of the absorbent body were visually confirmed for changes in state when the body fluid absorbent article was shaken by hand.
◎ No change at all. ○ Absorber structure does not change. △ Absorber internal structure changes depending on the load condition. × Completely moving

Explanatory drawing of the measuring apparatus used for this invention. Explanatory drawing of a measurement part same as the above. Explanatory drawing of the shape of the absorptive complex in this invention. Explanatory drawing of the apparatus used for preparation of the absorptive composite_body | complex in this invention. Detailed explanatory drawing of the A section of FIG. Explanatory drawing of the adhesive agent coating method in Example 2. FIG. Explanatory drawing of Example 6. FIG.

Claims (11)

It is a disposable body fluid absorbent article composed of a liquid-permeable sheet, a liquid-impermeable sheet, and an absorbent composite interposed therebetween, and the absorbent composite is composed of a base material and a water-absorbent resin, so that the total absorption The resin ratio is 65% by mass or more and 99% by mass or less with respect to the weight of the conductive composite, the resin area filling rate is 1 to 30%, and 50% or more of the total water-absorbing resin is bonded to the base material. Disposable body fluid absorbent article. 2. The body fluid absorbent article according to claim 1, wherein the base material of the absorbent composite is cloth and / or paper. The body fluid-absorbing article according to any one of claims 1 to 2, wherein the water-absorbent resin is adhered to the base material without an adhesive. The water-absorbent resin has a particle shape, and 50% or more of the particles are an absorptive composite in which a part of the base fiber is incorporated in the water-absorbent resin particles. The body fluid absorbent article according to any one of claims 1 to 3. The surface strength of the water absorbent resin in the absorbent composite is 0.1 N or more and 5.5 N or less, and the non-pressure absorption capacity of the water absorbent resin is 55 g / g or more. The body fluid absorbent article according to any one of the above. The water-absorbing resin in the absorbent composite is a resin having a carboxylic acid group in the side chain, and 50% or more of the acid groups in the water-absorbing resin are neutralized in the form of an ammonium salt. The bodily fluid absorption article in any one of -5. The body fluid-absorbing article according to any one of claims 1 to 6, wherein the water-absorbent resin is a polyacrylate copolymer. The body fluid absorbent article according to any one of claims 1 to 7, wherein the base material of the absorbent composite is a cellulosic material. The article according to any one of claims 1 to 8, wherein the absorbent composite, the liquid-permeable sheet and / or the liquid-impermeable sheet are fixed with an adhesive. It is a disposable body fluid absorbent article composed of a liquid-permeable sheet, a liquid-impermeable sheet, and an absorbent composite interposed therebetween, and the absorbent composite is composed of a base material and a water-absorbent resin, so that the total absorption A bodily fluid-absorbing article having a resin ratio of 65% by mass to 99% by mass and a liquid diffusion length of 200 mm or more with respect to the weight of the functional composite. The body fluid absorbent article according to claim 10, wherein the absorbent composite has an area weight of 0.05 g / cm ² or less and an absorption ratio of 40 g / g or more.

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