Composite absorber and hygienic product using same

Abstract

Provided is a composite absorbent which can stably exhibit sufficient absorption performance when absorbing blood and which can suppress blood leakage. And the composite absorber (4) is a hygienic product for absorbing blood. The composite absorbent contains a polymer absorbent and at least one of a superabsorbent polymer and pulp fibers, and the polymer absorbent is provided with a hydrophilic continuous skeleton and continuous pores. In the polymer absorbent, in a pore distribution representing the relationship between the pore volume and the pore diameter in the range of 0.003-100 [mu] m, the maximum volume pore diameter at which the proportion of the pore volume is the maximum is in the range of 1-95 [mu] m, and the proportion of the pore volume of pores having a pore diameter of 7 [mu] m or less is less than 46% of the pore volume of all pores.

Description

Technical Field

[0001] The present invention relates to a composite absorbent and a sanitary product using the same. Background Art

[0002] As an absorbent for sanitary products such as sanitary napkins, an absorbent containing pulp fibers and super absorbent polymers is known. By containing super absorbent polymers, the amount of body fluid absorbed by the absorbent can be increased. However, for super absorbent polymers, during the absorption of blood (menstrual blood), red blood cells in the blood adhere to the surface, so the absorption of blood takes time, and the absorption rate of blood may be lower than the absorption rate of urine. In this case, the absorbent may not be able to stably exert its absorption performance.

[0003] As a means to cope with this situation, a polymer foam material is disclosed in Patent Document 1. The polymer foam material is characterized by being able to absorb blood and blood-based fluids, having an interconnected open-cell, hydrophilic, soft nonionic polymer foam structure, and having a specified capillary specific surface area, resistance to compressive strain, free absorption capacity, and salt.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 3432828 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] According to Patent Document 1, the polymer foam material is a porous absorbent having a three-dimensional network skeleton structure, and absorbs blood in its pores. Therefore, during the absorption of blood, it is possible to inhibit red blood cells in the blood from adhering to the surface and making it difficult to absorb blood. Thus, the absorption rate of blood can be improved. Therefore, for example, it is possible to consider replacing part or all of the highly absorbent polymer with a polymer foam material.

[0009] However, the polymer foam material is a structure whose volume does not change before and after the absorption of blood, so it is impossible to absorb blood to a volume greater than the pore volume. Therefore, it is possible that it is difficult to obtain a sufficient absorption amount and sufficient absorption performance. In addition, when the amount of blood discharged is a large amount, it is possible that the polymer foam material cannot completely absorb the blood. In this case, blood may leak from the absorbent containing the polymer foam material.

[0010] An object of the present invention is to provide a composite absorbent body which can stably exhibit sufficient absorption performance when absorbing blood and can suppress blood leakage, and a sanitary product using the composite absorbent body.

[0011] Solutions for solving problems

[0012] One embodiment of the present invention is a composite absorbent for use in sanitary products for absorbing blood, comprising at least one of a highly absorbent polymer and pulp fibers and a polymer absorbent having a hydrophilic continuous skeleton and continuous pores, wherein in the aforementioned polymer absorbent, in a pore distribution representing the relationship between pore diameters in the range of 0.003 to 100 μm and pore volume, the proportion of the pore volume becomes the largest in the range of the maximum volume pore diameter of 1 to 95 μm, and the proportion of the pore volume of pores with a pore diameter of 7 μm or less is less than 46% of the pore volume of all pores.

[0013] Another aspect of the present invention is a sanitary product including a top sheet, a back sheet, and the composite absorbent body located between the top sheet and the back sheet.

[0014] Effects of the Invention

[0015] According to the present invention, it is possible to provide a composite absorbent body that can stably exhibit sufficient absorption performance when absorbing blood and can suppress blood leakage, and a sanitary product using the composite absorbent body. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic plan view of the sanitary napkin 1 according to the embodiment, in a developed state, as viewed in the thickness direction from the skin-opposing side.

[0017] Figure 2 This is a diagram for explaining a production process of absorbent A which is an example of the polymer absorbent according to the embodiment.

[0018] Figure 3 This is a SEM photograph of absorbent A at a magnification of 50 times.

[0019] Figure 4 This is a SEM photograph of absorbent A at a magnification of 100 times.

[0020] Figure 5 This is a SEM photograph of absorbent A at a magnification of 500 times.

[0021] Figure 6 This is a SEM photograph of absorbent A at a magnification of 1500 times.

[0022] Figure 7 This is a graph showing the relationship between the blood preservation rate and the blood sucking time. DETAILED DESCRIPTION

[0023] This embodiment relates to the following aspects.

[0024] [Method 1]

[0025] A composite absorbent for use in sanitary products for absorbing blood, comprising at least one of a highly water-absorbent polymer and pulp fibers and a polymer absorbent having a hydrophilic continuous skeleton and continuous pores, wherein in the polymer absorbent, in a pore distribution representing the relationship between pore diameters in the range of 0.003 to 100 μm and pore volume, the ratio of the pore volume becomes the largest in the range of the maximum volume pore diameter of 1 to 95 μm, and the ratio of the pore volume of pores with a pore diameter of 7 μm or less is less than 46% of the pore volume of all pores.

[0026] The present composite absorbent contains at least one of a highly absorbent polymer and pulp fibers and a high molecular absorbent. That is, at least a portion of the highly absorbent polymer or at least a portion of the pulp fibers in a conventional absorbent is replaced by a high molecular absorbent. Here, in the high molecular absorbent, there are fewer pores (less than 46%) with a pore diameter smaller than the size of red blood cells in blood (menstrual blood), i.e., 7 to 8 μm, so the adhesion of red blood cells to the surface is suppressed, and blood can enter the pores of the high molecular absorbent. In addition, since the pores are continuous, blood can enter the deep pores of the high molecular absorbent. As a result, the high molecular absorbent can quickly absorb blood without being hindered by red blood cells, and can stably exert the blood retention ability of the high molecular absorbent to absorb a large amount of blood. That is, in addition to being able to quickly absorb blood and replace pulp fibers, it can also absorb a large amount of blood and replace highly absorbent polymers. Therefore, since the composite absorbent contains such a polymer absorbent, it is not blocked by red blood cells when absorbing blood, and can stably exert sufficient absorption performance, and can suppress blood leakage. It should be noted that in the case of a polymer absorbent having a pore distribution in which the maximum volume pore diameter exceeds 95 μm and the pore volume ratio is the largest, as a whole, the number of pores with excessively large pore diameters increases, and blood that once entered the pores is likely to pass through the pores and be released outside the pores again.

[0027] [Method 2]

[0028] The composite absorbent according to aspect 1, wherein the one-minute value of the blood retention rate of the polymer absorbent is 6.5 g / g or more.

[0029] In the present composite absorbent, the 1-minute value of the blood retention rate of the polymer absorbent is very high (6.5 g / g or more), so the polymer absorbent can absorb blood (menstrual blood) quickly and in large quantities. That is, the polymer absorbent can absorb blood quickly and can stably exert the blood retention ability of the polymer absorbent to absorb a large amount of blood. Therefore, when absorbing blood, the present composite absorbent can stably exert sufficient absorption performance and can suppress blood leakage.

[0030] [Method 3]

[0031] The composite absorbent according to aspect 1 or 2, wherein in the polymer absorbent, the ratio of the pore volume of pores having a pore diameter of 53 μm or more in the pore distribution is less than 29% of the pore volume of all pores.

[0032] In the present composite absorbent, there are few (less than 29%) pores with large pore diameters (53 μm or more) in the polymer absorbent. Therefore, it is less likely that the pore diameter is too large relative to the red blood cells in the blood (menstrual blood), and the red blood cells that once entered the pores pass through the pores and are released out of the pores again. Therefore, the polymer absorbent can more stably exert its blood-retaining ability and absorb a large amount of blood. As a result, when absorbing blood, the present composite absorbent can stably exert sufficient absorption performance and can suppress blood leakage.

[0033] [Method 4]

[0034] The composite absorbent according to any one of aspects 1 to 3, wherein in the polymer absorbent, the ratio of the pore volume of pores having a pore diameter of 4 μm or less in the pore distribution is less than 40% of the pore volume of all pores.

[0035] In the present composite absorbent, there are few (less than 40%) pores in the polymer absorbent that are smaller than the size of 4 μm, which is a pore diameter that allows red blood cells in the blood (menstrual blood) to enter the capillaries and deform. Therefore, the adhesion of red blood cells to the surface is further suppressed, and blood can enter the interior of the polymer absorbent. As a result, the polymer absorbent can quickly absorb blood, and can stably exert the blood retention ability of the polymer absorbent to absorb a large amount of blood. As a result, when absorbing blood, the present composite absorbent can stably exert sufficient absorption performance and can suppress blood leakage.

[0036] [Method 5]

[0037] The composite absorbent according to any one of aspects 1 to 4, wherein in the polymer absorbent, the ratio of the pore volume of pores having a pore diameter of 1 μm or more accounts for 90% or more of the pore volume of all pores.

[0038] In the present composite absorbent, there are few (less than 10%) pores in the polymer absorbent that are smaller than the pore diameter of 1 μm, which is a size that is difficult for the plasma component (water) in the blood (menstrual blood) to enter. Therefore, the adhesion of the plasma component to the surface is suppressed, and the blood can enter the inside of the polymer absorbent. As a result, the polymer absorbent can absorb blood quickly, and can stably exert the blood retention ability of the polymer absorbent to absorb a large amount of blood. As a result, when absorbing blood, the present composite absorbent can stably exert sufficient absorption performance and can suppress blood leakage.

[0039] [Method 6]

[0040] The composite absorbent according to any one of aspects 1 to 5, wherein the continuous skeleton of the polymer absorbent has a hydrophilic group.

[0041] In the composite absorbent, when the polymer absorbent absorbs blood, the hydrophilic groups are ionized and repel each other, thereby expanding the framework and the pores between the frameworks, and the pore volume becomes larger than before the blood absorption. Therefore, the polymer absorbent can absorb blood (menstrual blood) more quickly and can absorb a larger amount of blood. Therefore, when the composite absorbent absorbs blood, it can stably exert sufficient absorption performance and can inhibit blood leakage.

[0042] [Method 7]

[0043] The composite absorbent according to any one of aspects 1 to 6, wherein the hydrophilic group has a property of absorbing blood and becoming negatively charged.

[0044] In the present composite absorbent, when the polymer absorbent absorbs blood, if the red blood cells with negative charge and the polymer absorbent that absorbs blood and becomes negatively charged come close to each other, the negative charges repel each other. Therefore, the red blood cells are less likely to aggregate in the pores and can easily penetrate into the polymer absorbent. As a result, the polymer absorbent can absorb blood (menstrual blood) more quickly and in larger quantities. As a result, the present composite absorbent can stably exert sufficient absorption performance when absorbing blood and can suppress blood leakage.

[0045] [Method 8]

[0046] The composite absorbent core according to any one of aspects 1 to 7, comprising the pulp fibers.

[0047] In this composite absorbent, blood (menstrual blood) is absorbed by pulp fibers very quickly, and the blood absorbed by the pulp fibers is quickly transported to the polymer absorbent. Therefore, the pulp fibers can absorb blood again, and thus the reduction in their absorption rate can be suppressed. In addition, by mixing the pulp fibers, the softness of the composite absorbent can be maintained and its absorption capacity can be increased. Thus, the absorption capacity of sanitary products using the composite absorbent can be increased without impairing the wearing feel of the sanitary products using the composite absorbent. Therefore, when absorbing blood, the composite absorbent can stably exert sufficient absorption performance and can suppress blood leakage.

[0048] [Method 9]

[0049] A composite absorbent according to any one of methods 1 to 8, wherein the composite absorbent has a length direction and a width direction that are orthogonal to each other, the composite absorbent has a pair of linear high-density portions, the pair of high-density portions extend along the length direction or the width direction, and are arranged at intervals in the width direction or the length direction, and the polymer absorbent is located between one and the other of the pair of high-density portions in the width direction or the length direction.

[0050] Since the polymer absorbent is located between a pair of high-density parts where blood (menstrual blood) is easily discharged, the composite absorbent can ensure sufficient absorption capacity in this part. Therefore, even if a large amount of blood is discharged, the composite absorbent can absorb the large amount of blood and suppress blood leakage.

[0051] [Method 10]

[0052] A composite absorbent according to any one of methods 1 to 8, wherein the composite absorbent has a length direction and a width direction that are orthogonal to each other, the composite absorbent has a pair of linear high-density portions, the pair of high-density portions extend along the length direction or the width direction, are arranged at intervals in the width direction or the length direction, and the polymer absorbent is located on the outer side of each of the pair of high-density portions in the width direction or the length direction.

[0053] In the composite absorbent, when blood (menstrual blood) is discharged between the pair of high-density parts, the blood is diffused and dispersed in the direction in which the pair of high-density parts extend, so that the blood can be quickly absorbed by the polymer absorbent outside the pair of high-density parts. Thus, the composite absorbent can suppress blood leakage.

[0054] [Method 11]

[0055] The composite absorbent according to any one of aspects 1 to 10, wherein the polymer absorbent is a monolithic absorbent.

[0056] Since the polymer absorbent of the composite absorbent is a monolithic absorbent, the discharged blood can be more reliably absorbed by the polymer absorbent, thereby suppressing blood leakage.

[0057] [Method 12]

[0058] A sanitary product comprising a top sheet, a back sheet, and the composite absorbent body according to any one of aspects 1 to 11 located between the top sheet and the back sheet.

[0059] Since the sanitary product includes the above-mentioned composite absorbent body, it can stably exhibit sufficient absorption performance when absorbing blood and can also suppress blood leakage.

[0060] Hereinafter, a preferred embodiment of the composite absorbent core of the present invention will be described using a sanitary napkin 1 as an example of a sanitary product to which the composite absorbent core is applied.

[0061] It should be noted that, in this specification, unless otherwise specified, "the object (such as a sanitary napkin, a composite absorbent, etc.) placed on a horizontal plane in an unfolded state as viewed from the upper side in the vertical direction (the surface sheet side when the object is a sanitary product) in the thickness direction of the object" is referred to as "looking down". In addition, "length direction" refers to "the direction in which the length of a longitudinally long object (such as a sanitary napkin, a composite absorbent, etc. in an unfolded state) is longer when viewed from above". "Width direction" refers to "the direction in which the length of a longitudinally long object is shorter when viewed from above". "Thickness direction" refers to "the direction perpendicular to the object placed on a horizontal plane in an unfolded state". These length directions, width directions and thickness directions are respectively in a mutually orthogonal relationship. In addition, in the thickness direction of the sanitary napkin 1, "the side that is relatively close to the skin surface of the wearer when the sanitary napkin 1 is worn" is referred to as the "skin-opposing side", and "the side that is relatively far from the skin surface of the wearer when the sanitary napkin 1 is worn" is referred to as the "non-skin-opposing side".

[0062] [Sanitary napkins]

[0063] Figure 1 1 is a schematic top view of a sanitary napkin 1 in an unfolded state to which a composite absorbent body 4 according to an embodiment is applied. The sanitary napkin 1 has a length direction L and a width direction W when viewed from above, and has a longitudinal shape with both end edges in the length direction L protruding outward in an arc shape, and a pair of wings 5 ​​extending from both end edges in the width direction W to both outsides at a position slightly forward of the center in the length direction L. However, the shape of the sanitary napkin 1 is not limited to such a form, and any shape corresponding to various uses, usage methods, etc. (e.g., an oblong shape, a rectangular shape, an hourglass shape, a wingless shape, etc.) can be adopted.

[0064] The sanitary napkin 1 is basically composed of a liquid-permeable surface sheet 2 forming the surface of the skin-opposing side of the sanitary napkin 1 in the thickness direction, a back sheet 3 forming the surface of the non-skin-opposing side of the sanitary napkin 1, and a composite absorbent body 4 located between these sheets. In addition, the sanitary napkin 1 is also provided with an adhesive portion (not shown) disposed on the surface of the non-skin-opposing side of the back sheet 3 (including a pair of wing portions 5) for bonding and fixing the sanitary napkin 1 to the inner surface of the wearer's underwear or other clothing.

[0065] The sanitary napkin 1 (composite absorbent body 4) also includes a pair of linear high-density parts 6 extending along the length direction L and arranged at intervals in the width direction W, and also includes a pair of linear high-density parts 7 extending along the width direction W and arranged at intervals in the length direction L. Among them, "along a prescribed direction" includes not only a case parallel to the direction, but also a case of deviation from the direction by ±30°. The high-density parts 6 and 7 are formed, for example, by embossing the surface sheet 2 and the composite absorbent body 4 in the thickness direction. It should be noted that either of the high-density parts 6 and 7 may be absent.

[0066] It should be noted that the sanitary napkin 1 is not limited to such a configuration. For example, the sanitary napkin 1 may also include a pair of side panels for forming a leak-proof wall, the pair of side panels being located at both ends of the sanitary napkin 1 in the width direction W at a position closer to the skin-opposing side than the surface sheet 2, and being arranged in a manner extending in the length direction L. In this case, the pair of side panels may also each include a plurality of elastic members arranged in a manner along the length direction L.

[0067] In the sanitary napkin 1, the composite absorbent 4 is located between the top sheet 2 and the back sheet 3 and is formed by a water-absorbing member capable of absorbing body fluids such as menstrual blood (blood) discharged from the wearer and passing through the top sheet 2. The composite absorbent 4 contains a polymer absorbent having a hydrophilic continuous skeleton and continuous pores as the water-absorbing member.

[0068] When absorbing water, the polymer absorbent exhibits a unique water absorption behavior of introducing water into the continuous skeleton and then into the continuous pores. Therefore, when the polymer absorbent absorbs body fluids such as menstrual blood (blood), the hydrophilic continuous skeleton instantly introduces body fluids due to osmotic pressure and expands, thereby expanding the volume of the continuous pores, and then introducing body fluids into the expanded continuous pores. Therefore, the polymer absorbent can instantly absorb a large amount of body fluids. In this embodiment, the absorbed body fluid can also be transported to the super absorbent polymer with a higher water retention capacity and reliably retained in the super absorbent polymer.

[0069] In the sanitary napkin 1, the composite absorbent 4 includes, as an absorbent member, at least one of a highly absorbent polymer and pulp fibers in addition to a polymer absorbent having a hydrophilic continuous skeleton and continuous pores. In the polymer absorbent, in a pore distribution showing the relationship between the pore diameter and the pore volume in the range of pore diameters of 0.003 to 100 μm, the pore volume ratio is the largest in the range of the maximum volume pore diameter of 1 to 95 μm, and the pore volume ratio of pores with a pore diameter of 7 μm or less is less than 46% of the pore volume of all pores (in the range of pore diameters of 0.003 to 100 μm). In this specification, the pore diameter refers to the diameter of the pore.

[0070] Thus, the composite absorbent 4 contains at least one of a highly absorbent polymer and pulp fibers and a high molecular absorbent. That is, at least a portion of the highly absorbent polymer and pulp fibers contained in the absorbent of a conventional sanitary product is replaced by a high molecular absorbent. Here, in the high molecular absorbent, there are fewer pores (less than 46%) with a pore diameter smaller than the size of red blood cells in blood (menstrual blood), i.e., 7 to 8 μm, so the adhesion of red blood cells to the surface is suppressed, and blood can enter the pores of the high molecular absorbent. In addition, since the pores are continuous, blood can enter the deep pores of the high molecular absorbent. As a result, the high molecular absorbent can quickly absorb blood without being hindered by red blood cells, and can stably exert the blood retention ability of the high molecular absorbent and absorb a large amount of blood. That is, in addition to being able to quickly absorb blood and replace pulp fibers, it can also absorb a large amount of blood and replace highly absorbent polymers. Therefore, since the composite absorbent 4 contains such a polymer absorbent, it is not blocked by red blood cells when absorbing blood, and can stably exert sufficient absorption performance, and can suppress blood leakage. It should be noted that in the case of a polymer absorbent having a pore distribution in which the maximum volume pore diameter exceeds 95 μm and the pore volume ratio is the largest, as a whole, the number of pores with excessively large pore diameters increases, and blood that once enters the pores is easily released again through the pores.

[0071] Therefore, the sanitary napkin 1 including such a composite absorbent body 4 can also stably exhibit sufficient absorption performance when absorbing blood, and can suppress blood leakage.

[0072] Hereinafter, various components of sanitary products to which the composite absorbent body of the present invention is applied will be further described using the sanitary napkin 1 described above.

[0073] (Surface Sheet)

[0074] like Figure 1As shown, the top sheet 2 has an outer shape extending from one side edge to the other side edge in the length direction L of the sanitary napkin 1 and extending from the vicinity of one side edge to the vicinity of the other side edge in the width direction W of the sanitary napkin 1 when viewed from above. The top sheet 2 is arranged at a position on the skin-opposing side in the thickness direction of the sanitary napkin 1, and constitutes a contact surface that can abut against the skin of the wearer, that is, a surface on the skin-opposing side of the sanitary napkin 1. The top sheet 2 is formed by a liquid-permeable sheet member.

[0075] In addition, if Figure 1 As shown, the top sheet 2 has slightly larger dimensions in the length direction L and the width direction W than the composite absorbent body 4 disposed on the non-skin opposite side of the top sheet 2. In the present embodiment, the top sheet 2 further extends on a pair of wing portions 5 in the width direction W. Furthermore, the top sheet 2 is joined to the back sheet 3 located on the non-skin opposite side at the peripheral portion.

[0076] In the present invention, there is no particular limitation on the outer shape, various sizes, basis weight, etc. of the surface sheet as long as it can be used as the surface sheet of sanitary products, and any outer shape, various sizes, basis weight, etc. corresponding to the desired liquid permeability, skin feel, softness, strength, etc. can be adopted.

[0077] (Back sheet)

[0078] The back sheet 3 has an outer shape extending from one end edge in the length direction L of the sanitary napkin 1 to the other end edge, and from one end edge in the width direction W of the sanitary napkin 1 to the other end edge when viewed from above. The back sheet 3 is arranged at a position on the non-skin-opposite side in the thickness direction of the sanitary napkin 1, constituting the non-skin-opposite side of the sanitary napkin 1. The back sheet 3 is formed by a liquid-impermeable sheet member to prevent body fluids such as menstrual blood (blood) from leaking to the outside of the sanitary napkin 1 through the composite absorbent body 4.

[0079] In the present invention, the shape, size, basis weight, etc. of the back sheet are not particularly limited as long as they can be used as the back sheet of sanitary products, and any shape, size, basis weight, etc. corresponding to the desired leakage prevention performance, air permeability, strength, etc. can be adopted.

[0080] (Composite absorber)

[0081] like Figure 1 As shown, the composite absorbent body 4 has a longitudinal shape with the center of the length direction L and the width direction W of the sanitary napkin 1 as the center, and extends in a wide range from the vicinity of the end edge of one side to the vicinity of the end edge of the other side in the length direction L and the width direction W. In addition, the two end edges of the composite absorbent body 4 in the length direction L protrude in an arc shape toward the outside of the length direction L.

[0082] The composite absorbent 4 is arranged between the surface sheet 2 and the back sheet 3 in the thickness direction of the sanitary napkin 1, and is formed by a predetermined water-absorbent member capable of absorbing and retaining body fluids such as menstrual blood (blood) that pass through the surface sheet 2. The water-absorbent member includes at least one of pulp fibers and superabsorbent polymers described later, as well as water-absorbent materials such as polymer absorbents and sheets such as thin paper that retain these water-absorbent materials. That is, the composite absorbent 4 refers to a water-absorbent member composed of a water-absorbent material capable of absorbing and retaining body fluids and a sheet that retains the water-absorbent material. Among them, the form of the pulp fibers and superabsorbent polymers is not particularly limited.

[0083] In the sanitary napkin 1, the composite absorbent body 4 is bonded to the topsheet 2 and the backsheet 3 respectively by any adhesive such as a hot-melt adhesive.

[0084] The composite absorbent 4 contains a polymer absorbent having a hydrophilic continuous skeleton and continuous pores and showing a unique water absorption behavior as described above, and also contains at least one of pulp fibers and super absorbent polymers. When the polymer absorbent is a particle, as its size (when dry), the average value of the particle size can be listed as, for example, hundreds of μm (200 to 500 μm). The polymer absorbent can be in sheet form. Details about the polymer absorbent are described later. Super absorbent polymers are called SAP (Super Absorbent Polymer), and there is no particular restriction on their type, and materials known in the technical field can be used. For example, as super absorbent polymers, polyacrylic acid salt-based, polysulfonic acid salt-based, and maleic anhydride salt-based absorbent polymers can be listed. When the super absorbent polymer is a particle, as its size (when dry), the average value of the particle size can be listed as, for example, hundreds of μm (200 to 500 μm). Super absorbent polymers can also be in sheet form. As the type of pulp fiber, there is no particular restriction, and materials known in the technical field can be used. For example, pulp fibers include cellulose fibers. Cellulosic fibers include wood pulp, cross-linked pulp, non-wood pulp, regenerated cellulose, semi-synthetic cellulose, etc. As the size of pulp fibers, the average value of the major diameter of the fibers may be, for example, tens of μm (20 to 40 μm), and the average value of the fiber length may be, for example, several mm (2 to 5 mm). The composite absorbent may also be enclosed in a core material cover formed by a liquid-permeable sheet.

[0085] The absorbent material, which is at least one of pulp fibers and superabsorbent polymers, and the high molecular absorbent are arranged approximately uniformly throughout the composite absorbent body 4 when viewed from above, except for manufacturing errors. However, the present invention is not limited to this example, and may have other arrangements in which at least one of the absorbent materials is not approximately uniform but intentionally has a prescribed distribution. For example, the high molecular absorbent may be arranged between one and the other of a pair of high density portions 6 in the width direction W with a basis weight higher than other regions, or between one and the other of a pair of high density portions 7 in the length direction L with a basis weight higher than other regions. Alternatively, the high molecular absorbent may be arranged on the outer side of each of the pair of high density portions 6 in the width direction W with a basis weight higher than other regions, or on the outer side of each of the pair of high density portions 7 in the length direction L with a basis weight higher than other regions. In order to reliably transport the body fluid absorbed by the pulp fibers to the superabsorbent polymer, the high molecular absorbent body is preferably in contact with the superabsorbent polymer.

[0086] (Basic weight of pulp fiber) / (Basic weight of polymer absorbent)) is more preferably greater than 1 and less than 10, and more preferably greater than 1 and less than 5. In addition, from the above viewpoint, (Basic weight of superabsorbent polymer) / (Basic weight of polymer absorbent) is more preferably greater than 1 and less than 10, and more preferably greater than 1 and less than 5.

[0087] The basis weight of the polymer absorbent, the basis weight of the pulp fiber, and the basis weight of the super absorbent polymer can be appropriately selected according to the absorption performance required of the composite absorbent 4. For example, the basis weight of the polymer absorbent can be 1 to 100 g / m 32 The basis weight of the pulp fiber may be 50 to 500 g / m 32 The basis weight of the super absorbent polymer may be 50 to 500 g / m 32 .

[0088] In the present invention, the shape, dimensions, basis weight, etc. of the composite absorbent are not particularly limited as long as they do not hinder the effects of the present invention, and any shape, dimensions, basis weight, etc. corresponding to the desired absorbency, softness, strength, etc. can be adopted.

[0089] Hereinafter, the polymer absorbent used in the composite absorbent of the present invention will be described in more detail.

[0090] [Polymer absorbent]

[0091] If the polymer absorbent has a hydrophilic continuous skeleton and continuous pores, when absorbing water, it shows a water absorption behavior of introducing water into the continuous skeleton and then into the continuous pores. In the pore distribution showing the relationship between the pore diameter and the pore volume in the range of 0.003 to 100 μm, the ratio of the pore volume becomes the largest in the range of 1 to 95 μm of the maximum volume pore diameter, and the ratio of the pore volume of pores with a pore diameter of 7 μm or less is less than 46% of the pore volume of all pores (in the range of 0.003 to 100 μm of pore diameter), and there is no particular limitation. Such a polymer absorbent includes, for example, a hydrolyzate of a cross-linked polymer of two or more monomers containing at least (meth) acrylic acid ester, and a polymer compound having at least one hydrophilic group in the functional group can be listed. More specifically, it is a hydrolyzate of a cross-linked polymer of a (meth) acrylic acid ester and a compound containing two or more vinyl groups in one molecule, and a polymer compound having at least a -COONa group as a hydrophilic group can be listed. Such a polymer absorbent is an organic porous body having at least one -COONa group in one molecule, and may further have a -COOH group as a hydrophilic group. The -COONa groups are substantially uniformly distributed in the skeleton of the porous body.

[0092] If the polymer absorbent has the structure as described above, as described later, the hydrophilic continuous skeleton is easy to stretch (i.e., easy to expand) when absorbing body fluids such as menstrual blood (blood), and the continuous pores are also easy to expand. Therefore, more body fluids can be introduced into the continuous pores more quickly, and excellent absorption performance can be exerted as an absorbent material. In addition, there are few pores (less than 46%) that are smaller than the size of red blood cells in blood (menstrual blood), that is, the pore diameter of 7 to 8 μm, so the adhesion of red blood cells to the surface of the blood is suppressed, and the blood retention ability of the polymer absorbent can be stably exerted to absorb a large amount of blood. In addition, the polymer absorbent has a pore distribution in which the maximum volume pore diameter is in the range of 1 to 95 μm, where the ratio of pore volume is the largest, so the pore diameter as a whole is of appropriate size, and it is easy to appropriately retain the blood that has once entered the pores.

[0093] In addition, in this specification, (meth)acrylate means acrylate or methacrylate.

[0094] The polymer absorbent is formed, for example, by the hydrolysis product of a cross-linked polymer of (meth)acrylate and divinylbenzene. In such a polymer absorbent, a hydrophilic continuous skeleton is formed by an organic polymer having at least a -COONa group (hydrophilic group), and between the skeletons are formed interconnected pores (continuous pores) that serve as the absorption site for the absorption target fluid (e.g., body fluids such as menstrual blood (blood)). It should be noted that the hydrolysis treatment converts the -COOR group (i.e., carboxylate group) of the cross-linked polymer into a -COONa group or a -COOH group (see Figure 2 ), so the polymer absorbent can have a -COOR group.

[0095] The presence of the hydrophilic groups, ie, -COOH groups and -COONa groups, in the organic polymer forming the hydrophilic continuous skeleton can be confirmed by analysis using infrared spectrophotometry and a quantitative method for weakly acidic ion exchange groups.

[0096] Here, Figure 2 This is a diagram for explaining the production process of absorbent A, which is an example of a polymer absorbent. Figure 2 In the figure, the upper figure shows the polymerized constituent raw materials, the middle figure shows the monolith A which is a cross-linked polymer of (meth)acrylate and divinylbenzene, and the lower figure shows the absorbent A obtained by hydrolyzing and drying the monolith A in the middle figure.

[0097] Hereinafter, the polymer absorbent will be described using absorbent A formed of a hydrolyzate of a cross-linked polymer of (meth)acrylic acid ester and divinylbenzene as an example of the polymer absorbent.

[0098] It should be noted that the polymer absorbent is not limited to such absorbent A. The polymer absorbent may be, for example, a hydrolyzate of a cross-linked polymer of a (meth)acrylate and a compound having two or more vinyl groups in one molecule. Alternatively, the polymer absorbent may be, for example, a hydrolyzate of a cross-linked polymer of two or more monomers containing at least (meth)acrylate. However, if the polymer absorbent is a monolithic absorbent, it has the following advantages: it can absorb body fluids quickly, and the body fluids temporarily retained in the polymer absorbent can be more reliably transported to the highly absorbent polymer.

[0099] It should be noted that in the following description, "monolith A" refers to an organic porous body formed of a cross-linked polymer of (meth)acrylate and divinylbenzene before hydrolysis treatment, and is sometimes referred to as a "monolithic organic porous body". In addition, "absorbent A" is a hydrolyzate of a cross-linked polymer of (meth)acrylate and divinylbenzene (monolith A) after hydrolysis treatment and drying treatment. It should be noted that in the following description, absorbent A refers to an absorbent in a dry state.

[0100] First, the structure of the absorbent A will be described.

[0101] As mentioned above, the absorbent has a hydrophilic continuous skeleton and continuous pores. Figure 2 As shown, the absorbent A, which is an organic polymer having a hydrophilic continuous skeleton, is obtained by cross-linking and polymerizing (meth)acrylate as a polymerization monomer and divinylbenzene as a cross-linking monomer, and then hydrolyzing the obtained cross-linked polymer (monolith A).

[0102] The organic polymer forming the hydrophilic continuous skeleton has a polymerized residue of ethylene (hereinafter referred to as "structural unit X") and a cross-linked polymerized residue of divinylbenzene (hereinafter referred to as "structural unit Y") as structural units. Furthermore, the polymerized residue of ethylene in the organic polymer forming the hydrophilic continuous skeleton (structural unit X) has a hydrophilic group generated by hydrolysis of a carboxylic acid ester group, i.e., a -COONa group, or a group of both a -COOH group and a -COONa group. It should be noted that when the polymerized monomer is a (meth)acrylate, the polymerized residue of ethylene (structural unit X) has a -COONa group, a -COOH group and an ester group.

[0103] In the absorbent A, the ratio of the cross-linked polymerized residues of divinylbenzene (structural unit Y) in the organic polymer forming the hydrophilic continuous skeleton is, for example, 0.1 to 30 mol%, preferably 0.1 to 20 mol%, relative to the total structural units. For example, in the absorbent A containing butyl methacrylate as a polymerization monomer and divinylbenzene as a cross-linking monomer, the ratio of the cross-linked polymerized residues of divinylbenzene (structural unit Y) in the organic polymer forming the hydrophilic continuous skeleton is, for example, about 3%, preferably 0.1 to 10 mol%, and more preferably 0.3 to 8 mol%, relative to the total structural units. It should be noted that when the ratio of the cross-linked polymerized residues of divinylbenzene in the organic polymer forming the hydrophilic continuous skeleton is 0.1 mol% or more, the strength of the absorbent A is unlikely to decrease, and when the ratio of the cross-linked polymerized residues of divinylbenzene is 30 mol% or less, the absorption amount of the absorption target liquid is unlikely to decrease.

[0104] In the absorbent A, the organic polymer forming the hydrophilic continuous skeleton may be composed only of the structural unit X and the structural unit Y, or, in addition to the structural unit X and the structural unit Y, may also have structural units other than the structural unit X and the structural unit Y, that is, polymerization residues of monomers other than (meth)acrylate and divinylbenzene.

[0105] Examples of structural units other than structural unit X and structural unit Y include polymerization residues of monomers such as styrene, α-methylstyrene, vinyltoluene, vinylbenzyl chloride, glycidyl (meth)acrylate, isobutylene, butadiene, isoprene, chloroprene, vinyl chloride, vinyl bromide, vinylidene chloride, tetrafluoroethylene, (meth)acrylonitrile, vinyl acetate, ethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and trimethylolpropane tri(meth)acrylate.

[0106] The ratio of the structural units other than the structural unit X and the structural unit Y in the organic polymer forming the hydrophilic continuous skeleton is, for example, 0 to 50 mol %, or preferably 0 to 30 mol % based on the total structural units.

[0107] In addition, the thickness of the hydrophilic continuous skeleton of the absorbent A is preferably 0.1 to 100 μm. If the thickness of the hydrophilic continuous skeleton of the absorbent A is 0.1 μm or more, the space (pores) in the porous body for introducing the absorption target liquid (body fluid) is not easily crushed during absorption, and the absorption amount is not easily reduced. On the other hand, when the thickness of the hydrophilic continuous skeleton is 100 μm or less, it is easy to obtain an excellent absorption speed.

[0108] It should be noted that the pore structure of the hydrophilic continuous skeleton of absorbent A is a continuous bubble structure, so the thickness of the continuous skeleton is measured using the skeleton cross section appearing in the test piece for electron microscope measurement as the evaluation site of the thickness. The continuous skeleton is formed by the intervals between the water (water droplets) removed by the dehydration / drying treatment after hydrolysis, so most of them are polygonal in shape. Therefore, the thickness of the continuous skeleton is set to the average value of the diameter (μm) of the circle circumscribed with the polygonal cross section. In addition, there are also occasional cases where small holes are opened in the polygon. In this case, the circumscribed circle of the polygonal cross section surrounding the small hole is measured.

[0109] Furthermore, the average diameter of the continuous pores of the absorbent A is preferably 1 to 1000 μm. If the average diameter of the continuous pores of the absorbent A is 1 μm or more, the spaces (pores) of the porous body for introducing the absorption target liquid (body fluid) are not easily crushed during absorption, and the absorption rate is not easily reduced. On the other hand, when the average diameter of the continuous pores is 1000 μm or less, it is easy to obtain an excellent absorption rate.

[0110] It should be noted that the average diameter (μm) of the continuous pores of the absorbent A can be measured by mercury intrusion porosimetry, and the maximum value of the pore distribution curve obtained by the mercury intrusion porosimetry is used. For the measurement of the average diameter of the continuous pores, a sample dried in a reduced pressure dryer set at a temperature of 50° C. for more than 18 hours is used as the sample, regardless of the ionic type of the absorbent A. It should be noted that the final pressure is set to 0 Torr.

[0111] Figure 3 This is a SEM photo of absorbent A at a magnification of 50 times. Figure 4 This is a SEM photo of absorbent A at a magnification of 100 times. Figure 5 This is a SEM photo of absorbent A at a magnification of 500 times. Figure 6 This is a SEM photo of absorbent A at a magnification of 1500 times. Figure 3 to Figure 6 The absorbent A shown is an example of an absorbent using butyl methacrylate as a polymerizable monomer and divinylbenzene as a crosslinking monomer, and each of them has a cubic structure of 2 mm square.

[0112] Figure 3 to Figure 6The absorbent A shown has many bubble-like macropores and has overlapping portions of these bubble-like macropores. The absorbent A has a continuous bubble structure in which the overlapping portions of the macropores become common openings (mesopores), that is, a continuous bubble structure (continuous macropore structure).

[0113] The overlapping parts of the macropores form common openings (mesopores) with an average diameter of 1 to 1000 μm, preferably 10 to 200 μm, and particularly preferably 20 to 100 μm in a dry state, most of which form an open-pore structure. When the average diameter of the mesopores in a dry state is 1 μm or more, the absorption rate of the absorption target liquid becomes better. On the other hand, when the average diameter of the mesopores in a dry state is 1000 μm or less, the absorbent A is not easily brittle.

[0114] It should be noted that the number of overlaps between such macropores is about 1 to 12 per macropore, and in most cases, about 3 to 10.

[0115] In addition, since the absorbent A has such a continuous bubble structure, it has the following advantages: macropore groups and mesopore groups can be uniformly formed, and the pore volume and specific surface area can be significantly increased compared with the particle aggregation type porous body described in Japanese Patent Application Laid-Open No. 8-252579.

[0116] The total pore volume of the pores (empty holes) of the absorbent A is preferably 0.5 to 50 mL / g, more preferably 2 to 30 mL / g. When the total pore volume of the absorbent A is 0.5 mL / g or more, sufficient pore volume can be ensured in the absorbent A, and therefore, sufficient water absorption can be ensured. In addition, the space (empty holes) of the porous body for introducing the absorption target liquid (body fluid) can be made less likely to be flattened during absorption, and the water absorption amount and water absorption rate can be made less likely to decrease. On the other hand, when the total pore volume of the absorbent A is less than 50 mL / g, the strength of the absorbent A can be made less likely to decrease.

[0117] It should be noted that the total pore volume can be measured using the mercury intrusion method. The sample for measuring the total pore volume does not depend on the ionic form of the absorbent A, and a sample dried for more than 18 hours in a reduced pressure dryer set at a temperature of 50°C is used. The final pressure reached is set to 0 Torr. By this mercury intrusion method, the cumulative (cumulative) pore volume distribution (the relationship between the pore diameter (or pore radius) and the cumulative pore volume), the log differential pore volume distribution (the relationship between the pore diameter (or pore radius) and the log differential pore volume), etc. are obtained. Based on this, the pore distribution with a pore diameter (or pore radius) within a specified range, the proportion of the pore volume of pores with a pore diameter (or pore radius) below / above a specified value in the pore distribution (the proportion of the pore volume relative to all pores) (%), etc. can be calculated. In addition, the total pore volume (mL / g), average pore radius (μm), maximum pore radius (μm), pore volume (mL / g) and proportion (%) of pores above ( / below) a specified pore diameter (or pore radius), etc. can be calculated.

[0118] The following will describe the state of the absorbent A when it comes into contact with a liquid such as body fluid (hereinafter referred to as "body fluid"), and the same applies to the case where the composite absorbent 4 including the absorbent A comes into contact with the body fluid. In addition, the mass of the body fluid absorbed is roughly proportional to the amount of the body fluid, so in the following description, the mass of the body fluid is sometimes simply referred to as the "amount of body fluid".

[0119] first, Figure 3 to Figure 6 The continuous pores of the absorbent A shown are pores in which a plurality of pores (pores) are interconnected, and the presence of many pores can be visually recognized by the naked eye from the appearance. If body fluids such as menstrual blood (blood) come into contact with such an absorbent A having many pores, the hydrophilic continuous skeleton first elongates (i.e., expands) by instantly introducing a portion of the body fluid due to osmotic pressure. The elongation of the continuous skeleton occurs in approximately all directions. In this way, the absorbent A, which becomes larger by absorbing a certain amount of body fluid, can further absorb a specified amount of body fluid into the enlarged continuous pores through capillary action. In this way, when the absorbent A absorbs water (body fluid), it exhibits a unique water absorption behavior of introducing water into the hydrophilic continuous skeleton and then introducing and absorbing it into the continuous pores.

[0120] Here, the body fluid absorbed into the hydrophilic continuous skeleton of absorbent A is not easily released from the continuous skeleton (i.e., it is not easy to release water). On the other hand, the body fluid absorbed into the continuous pores is easy to release water. Therefore, in the composite absorbent, the body fluid absorbed into the continuous pores releases water and is transported to the highly absorbent polymer with high water retention capacity, and is reliably retained in the highly absorbent polymer. It should be noted that, with respect to the amount of body fluid absorbed into the continuous skeleton of absorbent A and the amount of body fluid absorbed into the continuous pores, of the total amount of fluid absorbed by absorbent A, the amount of body fluid that releases water from absorbent A by centrifugal treatment (150G / 90 seconds) (water release amount) becomes the amount of body fluid absorbed into the continuous pores, and the other amount of body fluid (the amount of body fluid that does not release water from absorbent A by centrifugal treatment) becomes the amount of body fluid absorbed into the continuous skeleton.

[0121] In addition, for the body fluid absorbed by the absorbent A, more body fluid is retained in the pores than in the hydrophilic continuous matrix. Since most of the body fluid absorption by the absorbent A is carried out by retaining the body fluid in the pores by utilizing the capillary phenomenon, the larger the porosity (the volume of the pores of the pores relative to the volume of the absorbent A), which is the ratio of the volume of the pores of the pores (total pore volume), the more body fluid can be absorbed. It should be noted that the porosity is preferably 85% or more.

[0122] For example, if we find the above Figure 3 to Figure 6 The porosity of the absorbent A shown is as follows. First, the specific surface area of ​​the absorbent A obtained by mercury intrusion porosimetry is 400 m 2 / g, the pore volume is 15.5mL / g. The pore volume of 15.5mL / g means that the volume of the pores in 1g of absorbent A is 15.5mL. Assuming that the specific gravity of absorbent A is 1g / mL, the volume occupied by the pores in 1g of absorbent A, that is, the pore volume, is 15.5mL, and the volume of 1g of absorbent A is 1mL. Therefore, the total volume (volume) of 1g of absorbent A is 15.5+1(mL), and the ratio of the pore volume is the porosity, so the porosity of absorbent A is 15.5 / (15.5+1)×100≒94%.

[0123] Such an absorbent A having a hydrophilic continuous skeleton and continuous pores, i.e., a polymer absorbent, is applied in the form of particles, sheets, etc., to a composite absorbent for absorbing body fluids such as menstrual blood (blood), such as the composite absorbent 4 of the sanitary napkin 1 described above. Moreover, as described above, when the polymer absorbent absorbs water (directly or with the aid of pulp fibers), it exhibits a unique water absorption behavior of introducing water into the hydrophilic continuous skeleton and then into the continuous pores. Therefore, the polymer absorbent can instantly absorb a large amount of body fluids (in the pulp fibers) around it, and can then transport the absorbed body fluids (mainly the body fluids absorbed by the continuous pores) to the highly absorbent polymer with a higher water retention capacity, and reliably retain them in the highly absorbent polymer. Therefore, the composite absorbent using such a polymer absorbent can exhibit high absorption performance as an absorbent. Moreover, in the absorbent material A, i.e., the polymer absorbent, there are few pores (less than 46%) with a pore diameter smaller than the size of red blood cells in blood (menstrual blood), i.e., pore diameters of 7 to 8 μm. Therefore, the adhesion of red blood cells to the surface is suppressed, and the blood-retaining ability of the polymer absorbent can be stably exerted to absorb a large amount of blood.

[0124] In the present embodiment, the blood retention rate of the polymer absorbent is preferably 6.5 g / g or more in 1 minute (60 seconds). Thus, in the composite absorbent 4, the 1-minute value of the blood retention rate of the polymer absorbent is very high (6.5 g / g or more), so the polymer absorbent can absorb blood (menstrual blood) quickly and in large quantities. That is, the polymer absorbent can absorb blood quickly, and can stably exert the blood retention ability of the polymer absorbent to absorb a large amount of blood. Thus, when absorbing blood, the composite absorbent can stably exert sufficient absorption performance and can suppress blood leakage.

[0125] The 1 minute (60 seconds) value of the blood retention rate of the polymer absorbent including absorbent A is more preferably 7.0 g / g or more, and even more preferably 8.0 g / g or more. Thus, the polymer absorbent can absorb blood (menstrual blood) more quickly and in large quantities.

[0126] The blood preservation ratio was measured by the following method.

[0127] <Method for determining blood preservation ratio>

[0128] (1) Place a plastic cylinder with an inner diameter of 26 mm and a height of 40 mm in an aluminum foil cup with a diameter of 45 mm and put 0.1 g of a sample in it.

[0129] (2) Use a pipette to place 2 ml of defibrinated horse blood into a plastic cylinder and allow the sample to absorb blood for a specified period of time.

[0130] (3) A 500 μm nylon mesh manufactured by NBC Industries was placed on the sample, and 20 g of 10×10 cm No. 2 filter paper manufactured by ADVANTEC was placed on the nylon mesh, and a load of 930 g was placed on the filter paper.

[0131] (4) After 3 minutes, the load is removed and the mass M (g) of the filter paper is measured. Then, the blood absorption rate (g) per unit mass (g) of the sample within a predetermined time (for example, 1 minute) is calculated using the following formula.

[0132] Blood preservation ratio = 2-(M-20) / 0.1(g / g)

[0133] It should be noted that this measurement method was carried out under the conditions of a temperature of 25° C. and a humidity of 60%.

[0134] In the present embodiment, in the polymer absorbent, the proportion of the pore volume of pores with a pore diameter of 53 μm or more in the aforementioned pore distribution is preferably less than 29% of the pore volume of all pores. Thus, in the present composite absorbent 4, there are fewer (less than 29%) pores with large pore diameters (53 μm or more) in the polymer absorbent. Therefore, it is less likely that the pore diameter is too large relative to the red blood cells in the blood (menstrual blood), and the red blood cells that once entered the pores are released again outside the pores through the pores. Therefore, the polymer absorbent can more stably exert its blood-retaining ability and absorb a large amount of blood. As a result, the present composite absorbent can stably exert sufficient absorption performance when absorbing blood, and can suppress blood leakage.

[0135] In the present embodiment, in the polymer absorbent, the proportion of the pore volume of pores with a pore diameter of 4 μm or less in the pore distribution is preferably less than 40% of the pore volume of all pores. Thus, in the composite absorbent 4, in the polymer absorbent, there are few pores (less than 40%) with a pore diameter smaller than 4 μm, which is a size that allows red blood cells in blood (menstrual blood) to enter the capillaries and deform. Therefore, the adhesion of red blood cells to the surface is further suppressed, and blood can enter the interior of the polymer absorbent. As a result, the polymer absorbent can absorb blood quickly, and can stably exert the blood retention ability of the polymer absorbent and absorb a large amount of blood. As a result, when absorbing blood, the composite absorbent can stably exert sufficient absorption performance and can suppress blood leakage.

[0136] In the present embodiment, in the polymer absorbent, the ratio of the pore volume of pores having a pore diameter of 1 μm or more is preferably 90% or more of the pore volume of all pores, and more preferably 95% or more. Thus, in the composite absorbent 4, in the polymer absorbent, there are few pores (less than 10%) having a diameter smaller than 1 μm, which is a size that is difficult for the plasma component (water) in the blood (menstrual blood) to enter. Therefore, the adhesion of the plasma component to the surface is suppressed, and the blood can enter the interior of the polymer absorbent. Thus, the polymer absorbent can absorb blood quickly, and can stably exert the blood retention ability of the polymer absorbent and absorb a large amount of blood. Thus, when absorbing blood, the composite absorbent can stably exert sufficient absorption performance and can suppress blood leakage.

[0137] In the present embodiment, the continuous skeleton of the polymer absorbent preferably has a hydrophilic group. Examples of the hydrophilic group include -COONa groups and -COOH groups. Thus, in the present composite absorbent 4, if the polymer absorbent absorbs blood, the hydrophilic groups are ionized and repel each other, thereby causing the skeleton and the pores between the skeletons to expand, and the pore volume becomes larger than before the blood is absorbed. Therefore, the polymer absorbent can absorb blood (menstrual blood) more quickly and can absorb a larger amount of blood. Thus, when absorbing blood, the present composite absorbent can stably exert sufficient absorption performance and can inhibit blood leakage.

[0138] In the present embodiment, the hydrophilic group preferably has the property of absorbing blood and becoming negatively charged. Thus, in the composite absorbent 4, when the polymer absorbent absorbs blood, if the red blood cells having a negative charge and the polymer absorbent having absorbed blood and becoming negatively charged approach each other, the negative charges repel each other. Therefore, the red blood cells are less likely to aggregate in the pores and can easily penetrate into the polymer absorbent. Thus, the polymer absorbent can absorb blood (menstrual blood) more quickly and can absorb a larger amount of blood. Thus, when absorbing blood, the composite absorbent can stably exert sufficient absorption performance and can suppress blood leakage.

[0139] In the present embodiment, pulp fibers are preferably included. Thus, in the present composite absorbent 4, blood (menstrual blood) is absorbed extremely quickly by the pulp fibers, and the blood absorbed by the pulp fibers is quickly transported to the polymer absorbent. Therefore, the pulp fibers can absorb the blood again, and thus the decrease in their absorption rate can be suppressed. In addition, by mixing the pulp fibers, the softness of the composite absorbent can be maintained and its absorption capacity can be increased. Thus, the absorption capacity of the sanitary product using the composite absorbent can be increased without impairing the wearing feel. Thus, when absorbing blood, the present composite absorbent can stably exert sufficient absorption performance and can suppress blood leakage.

[0140] In the present embodiment, the composite absorbent 4 preferably has a pair of linear high-density portions 6 extending along the length direction L and arranged at intervals in the width direction W, and the polymer absorbent is located between one and the other of the pair of high-density portions 6 in the width direction W. And / or, the composite absorbent 4 preferably has a pair of linear high-density portions 7 extending along the width direction W and arranged at intervals in the length direction L, and the polymer absorbent is located between one and the other of the pair of high-density portions 7 in the length direction L. In this way, since the polymer absorbent is located between the pair of high-density portions 6 and / or 7 from which blood (menstrual blood) is easily discharged, the composite absorbent 4 can ensure sufficient absorption capacity in this portion. Therefore, even in the case of a large amount of blood excretion, the composite absorbent 4 can absorb the large amount of blood and can suppress blood leakage.

[0141] In the present embodiment, the composite absorbent 4 preferably includes a pair of linear high-density portions 6 extending in the longitudinal direction L and arranged at intervals in the width direction W, and the polymer absorbent is located outside each of the pair of high-density portions 6 in the width direction W. And / or, the composite absorbent 4 preferably includes a pair of linear high-density portions 7 extending in the width direction W and arranged at intervals in the longitudinal direction L, and the polymer absorbent is located outside each of the pair of high-density portions 7 in the longitudinal direction L. In this way, in the present composite absorbent 4, when blood (menstrual blood) is discharged between the pair of high-density portions 6 and / or 7, the blood is diffused and dispersed in the direction in which the pair of high-density portions 6 and / or 7 extend, so that the blood can be quickly absorbed by the polymer absorbent outside the pair of high-density portions 6 and / or 7. As a result, the present composite absorbent can suppress blood leakage.

[0142] In the present embodiment, the polymer absorbent is preferably a monolithic absorbent. Thus, the composite absorbent 4 can more reliably absorb the discharged blood into the polymer absorbent, thereby suppressing blood leakage.

[0143] In the present embodiment, as described above, the sanitary napkin 1 (sanitary product) comprises a surface sheet 2, a back sheet 3, and the composite absorbent body 4 located between the surface sheet 2 and the back sheet 3. Thus, the sanitary napkin 1 (sanitary product) comprises the composite absorbent body 4, and therefore, when absorbing blood, it is possible to stably exert sufficient absorption performance and to suppress blood leakage.

[0144] Hereinafter, a method for producing such a polymer absorbent will be described in detail by taking the absorbent A described above as an example.

[0145] [Method for producing polymer absorbent]

[0146] like Figure 2As shown, the absorbent A can be obtained through a cross-linking polymerization step and a hydrolysis step. These steps will be described below.

[0147] (Cross-linking polymerization process)

[0148] First, an oil-soluble monomer for crosslinking polymerization, a crosslinking monomer, a surfactant, water, and a polymerization initiator as required are mixed to obtain a water-in-oil emulsion in which the oil phase forms a continuous phase and water droplets are dispersed therein.

[0149] Moreover, for the above absorbent A, if Figure 2 As shown in the above figure, butyl methacrylate as (meth)acrylate is used as an oil-soluble monomer, divinylbenzene is used as a cross-linking monomer, sorbitan monooleate is used as a surfactant, and isobutyronitrile is used as a polymerization initiator to cross-link and polymerize to obtain a whole material A.

[0150] Specifically, for absorbent A, if Figure 2 As shown in the above figure, first, 9.2 g of tert-butyl methacrylate as an oil-soluble monomer, 0.28 g of divinylbenzene as a cross-linking monomer, 1.0 g of sorbitan monooleate (hereinafter referred to as "SMO") as a surfactant, and 0.4 g of 2,2'-azobis(isobutyronitrile) as a polymerization initiator are mixed and dissolved uniformly.

[0151] Next, a mixture of tert-butyl methacrylate / divinylbenzene / SMO / 2,2'-azobis(isobutyronitrile) was added to 180 g of pure water, and stirred under reduced pressure using a vacuum stirring degassing mixer (EME, Inc.) as a planetary stirring device to obtain a water-in-oil emulsion.

[0152] The emulsion was then quickly transferred to a reaction vessel and sealed, and the polymerization was carried out at 60°C for 24 hours while standing. After the polymerization, the contents were taken out, extracted with methanol, and dried under reduced pressure to obtain a monolith A with a continuous macroporous structure. It should be noted that the internal structure of monolith A was observed using SEM, and the results showed that monolith A had a continuous bubble structure and a continuous skeleton thickness of 5.4 μm. In addition, the average diameter of the continuous pores measured by mercury intrusion was 36.2 μm, and the total pore volume was 15.5 mL / g.

[0153] It should be noted that the content of divinylbenzene relative to all monomers is preferably 0.3 to 10 mol%, more preferably 0.3 to 5 mol%. In addition, the ratio of divinylbenzene relative to the total of butyl methacrylate and divinylbenzene is preferably 0.1 to 10 mol%, more preferably 0.3 to 8 mol%. It should be noted that in the absorbent A, the ratio of butyl methacrylate relative to the total of butyl methacrylate and divinylbenzene is 97.0 mol%, and the ratio of divinylbenzene is 3.0 mol%.

[0154] The amount of surfactant added can be set according to the type of oil-soluble monomer and the desired size of emulsion particles (macropores), and is preferably in the range of about 2 to 70% relative to the total amount of the oil-soluble monomer and the surfactant.

[0155] It should be noted that in order to control the bubble shape and size of the monolith A, alcohols such as methanol and stearyl alcohol; carboxylic acids such as stearic acid; hydrocarbons such as octane, dodecane, toluene; cyclic ethers such as tetrahydrofuran and dioxane, etc. can coexist in the polymerization system.

[0156] In addition, there is no particular limitation on the mixing method for forming an oil-in-water droplet type emulsion. For example, any mixing method may be used, such as a method of mixing all the components at once; a method of mixing the components after uniformly dissolving the oil-soluble components such as the oil-soluble monomer, surfactant and oil-soluble polymerization initiator, and the water-soluble components such as water and water-soluble polymerization initiator.

[0157] Furthermore, there is no particular limitation on the mixing device used to form the emulsion. Depending on the desired emulsion particle size, any device such as a conventional mixer, a homogenizer, a high-pressure homogenizer, etc. can be used. Furthermore, a so-called planetary stirring device can be used, in which the material to be processed is added to a mixing container and the mixing container is caused to rotate while revolving around an orbital axis in a tilted state, thereby stirring and mixing the material to be processed.

[0158] In addition, there is no particular restriction on the mixing conditions, and the stirring speed, stirring time, etc. can be arbitrarily set according to the desired emulsion particle size. It should be noted that when the planetary stirring device is used, the water droplets in the W / O emulsion can be uniformly generated, and the average diameter thereof can be arbitrarily set within a wide range.

[0159] The polymerization conditions of the water-in-oil emulsion can be various conditions depending on the types of monomers and initiators. For example, when azobisisobutyronitrile, benzoyl peroxide, potassium persulfate, etc. are used as polymerization initiators, heating polymerization can be carried out at a temperature of 30 to 100° C. in a sealed container under an inert atmosphere for 1 to 48 hours. When hydrogen peroxide-ferrous chloride, sodium persulfate-sodium bisulfite, etc. are used as polymerization initiators, polymerization can be carried out at a temperature of 0 to 30° C. in a sealed container under an inert atmosphere for 1 to 48 hours.

[0160] It should be noted that after the polymerization is completed, the contents are taken out and Soxhlet extraction is performed with a solvent such as isopropanol to remove unreacted monomers and residual surfactants, thereby obtaining Figure 2 The whole material A shown in the middle figure.

[0161] (Hydrolysis process)

[0162] Next, the step (hydrolysis step) of hydrolyzing the monolith A (crosslinked polymer) to obtain the absorbent A will be described.

[0163] First, the monolith A is immersed in dichloroethane to which zinc bromide is added, stirred at 40° C. for 24 hours, sequentially contacted with methanol, 4% hydrochloric acid, 4% sodium hydroxide aqueous solution and water for hydrolysis, and then dried to obtain a block-shaped absorbent A. Furthermore, the block-shaped absorbent A is crushed into a predetermined size to obtain a granular absorbent A. It should be noted that the form of the absorbent A is not limited to a granular form, and for example, it may be formed into a sheet form during or after drying.

[0164] In addition, the method for hydrolyzing the monolith A is not particularly limited, and various methods can be used. For example, an aromatic solvent such as toluene and xylene, a halogen solvent such as chloroform and dichloroethane, an ether solvent such as tetrahydrofuran and isopropyl ether, an amide solvent such as dimethylformamide and dimethylacetamide, an alcohol solvent such as methanol and ethanol, a carboxylic acid solvent such as acetic acid and propionic acid, or water as a solvent is brought into contact with a strong base such as sodium hydroxide; or a method of bringing it into contact with a hydrohalic acid such as hydrochloric acid, a Bronsted acid such as sulfuric acid, nitric acid, trifluoroacetic acid, methanesulfonic acid, and p-toluenesulfonic acid, or a Lewis acid such as zinc bromide, aluminum chloride, aluminum bromide, titanium (IV) chloride, cerium chloride / sodium iodide, and magnesium iodide, etc.

[0165] In addition, among the polymerization raw materials of the organic polymer forming the hydrophilic continuous skeleton of the absorbent A, the (meth)acrylate is not particularly limited, but is preferably a C1-C10 (i.e., carbon number 1-10) alkyl ester of (meth)acrylate, and particularly preferably a C4 (i.e., carbon number 4) alkyl ester of (meth)acrylate.

[0166] Examples of the C4 alkyl ester of (meth)acrylic acid include tert-butyl (meth)acrylate, n-butyl (meth)acrylate, and isobutyl (meth)acrylate.

[0167] The monomers used in the crosslinking polymerization may be only (meth)acrylate and divinylbenzene, or may contain other monomers other than (meth)acrylate and divinylbenzene.

[0168] In the latter case, other monomers are not particularly limited, and examples thereof include styrene, α-methylstyrene, vinyltoluene, vinylbenzyl chloride, glycidyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isobutylene, butadiene, isoprene, chloroprene, vinyl chloride, vinyl bromide, vinylidene chloride, tetrafluoroethylene, (meth)acrylonitrile, vinyl acetate, ethylene glycol di(meth)acrylate, and trimethylolpropane tri(meth)acrylate.

[0169] The ratio of the monomers other than the (meth)acrylic acid ester and divinylbenzene in all the monomers used for the crosslinking polymerization is preferably 0 to 80 mol %, more preferably 0 to 50 mol %.

[0170] In addition, the surfactant is not limited to the above-mentioned sorbitan monooleate, as long as it is a surfactant that can form a water-in-oil (W / O) emulsion when the cross-linking polymerization monomer is mixed with water. As such a surfactant, for example, nonionic surfactants such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan trioleate, polyoxyethylene nonylphenyl ether, polyoxyethylene stearyl ether, polyoxyethylene sorbitan monooleate, anionic surfactants such as potassium oleate, sodium dodecylbenzenesulfonate, sodium dioctyl sulfosuccinate, cationic surfactants such as distearyl dimethyl ammonium chloride, and amphoteric surfactants such as lauryl dimethyl betaine can be listed. These surfactants can be used alone or in combination of two or more.

[0171] In addition, the polymerization initiator preferably uses a compound that generates free radicals by heat and light irradiation. Furthermore, the polymerization initiator can be water-soluble or oil-soluble, and examples thereof include azobis(4-methoxy-2,4-dimethylvaleronitrile), azobisisobutyronitrile, azobisdimethylvaleronitrile, azobiscyclohexanenitrile, azobiscyclohexanecarbonitrile, azobis(2-methylpropionamidine) dihydrochloride, benzoyl peroxide, potassium persulfate, ammonium persulfate, hydrogen peroxide-ferrous chloride, sodium persulfate-sodium bisulfite, tetramethylthiuram disulfide, etc. However, depending on the situation, there is also a system in which polymerization is performed only by heating and light irradiation even without adding a polymerization initiator, so it is not necessary to add a polymerization initiator in such a system.

[0172] For polymer absorbents, when one wants to obtain (change) the desired absorption performance and pore distribution, the pore diameter, pore distribution, and thus the absorption performance can be adjusted mainly by adjusting the amount of surfactant added in the cross-linking polymerization process (for example: surfactant / monomer ratio) and the mixing conditions (for example: stirring speed, stirring time).

[0173] [Method for producing a composite absorbent containing a polymer absorbent]

[0174] The composite absorbent body is not particularly limited and can be manufactured using a known method, for example, using a fiber accumulation device equipped with a material feeder and a drum. The drum has a suction device on the inner side, including a fiber accumulation support body arranged on the outer peripheral surface of the drum and arranged in a manner that can rotate together with the drum. The fiber accumulation support body has a stacking depression for stacking pulp fibers, high molecular absorbents and super absorbent polymers. The material feeder supplies pulp fibers, high molecular absorbents and super absorbent polymers with adjusted basis weights (blending ratios) to the fiber accumulation support body in a mixed state. In the manufacturing method, the pulp fibers, high molecular absorbents and super absorbent polymers supplied in a mixed state by the material feeder are stacked in the stacking depressions of the fiber accumulation support body by a suction device to form a fiber accumulation body. Then, the fiber accumulation body is transported from the fiber accumulation support body to a sheet member coated with an adhesive on the surface, and the fiber accumulation body is wrapped with the sheet member, thereby manufacturing a composite absorbent body. Alternatively, a fiber-packed body of pulp fibers and high absorbent polymer may be prepared by the above method, and a high molecular absorbent may be separately spread on the fiber-packed body before being wrapped in the sheet member.

[0175] Example

[0176] Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

[0177] (A) Sample

[0178] The polymer absorbent produced by the above-mentioned production method is used as Examples 1 to 3, the Infinity granules are used as Comparative Example 1, and the super absorbent polymer is used as Comparative Example 2. Among them, the samples of Examples 1 to 3 are samples in which the surfactant / monomer ratio (wt%) and the stirring time (minutes) when forming the oil-in-water droplet type emulsion in the production method are changed. The Infinity granules of Comparative Example 1 are the granules described in Patent Document 1, which are absorbents manufactured by P&G. Although they have a structure (foaming structure) similar to that of the polymer absorbent, they do not have the function of swelling by absorbing water, unlike the polymer absorbent. The super absorbent polymer of Comparative Example 2 is UG840 manufactured by Sumitomo Seika Co., Ltd. Moreover, the samples of Examples 1 to 3 and Comparative Example 1 all use samples in the range of 1 to 95 μm, where the ratio of the pore volume is the largest in the pore distribution representing the relationship between the pore diameter and the pore volume in the range of 0.003 to 100 μm.

[0179] (B) Evaluation

[0180] The following items were evaluated for all or part of the above samples. The items were the ratio (to the ratio of the pore volume of all pores) (%) and the blood retention rate (g / g) of pores with a pore diameter (or pore radius) below / above a specified value in the pore distribution with a pore diameter (or pore radius) within a specified range.

[0181] (C) Results

[0182] (1) Ratio of pore volume of pores with a pore diameter of 7 μm or less

[0183] In the pore distribution in the range of pore diameters of 0.003 to 100 μm, the ratio of the pore volume of pores with a pore diameter of 7 μm or less to the pore volume of all pores was calculated based on the pore volume distribution measured by mercury intrusion. The results were 11%, 36%, and 45% in Examples 1, 2, and 3, respectively. The ratio was 47% in Comparative Example 1. Therefore, it was confirmed that in the polymer absorbent, the ratio of the pore volume of pores with a pore diameter of 7 μm or less in the pore distribution in the range of pore diameters of 0.003 to 100 μm was less than 46% of the pore volume of all pores.

[0184] (2) Ratio of pore volume of pores with a pore diameter of 53 μm or more

[0185] In the pore distribution in the range of pore diameters of 0.003 to 100 μm, the ratio of the pore volume of pores with a pore diameter of 53 μm or more to the pore volume of all pores was calculated based on the pore volume distribution measured by mercury intrusion. The results were 14%, 6%, and 3% in Examples 1, 2, and 3, respectively. The ratio was 3% in Comparative Example 1. Therefore, it was confirmed that in the polymer absorbent, the ratio of the pore volume of pores with a pore diameter of 53 μm or more in the pore distribution in the range of pore diameters of 0.003 to 100 μm was less than 29% of the pore volume of all pores.

[0186] (3) Ratio of pore volume of pores with a pore diameter of 4 μm or less

[0187] In the pore distribution in the range of pore diameters of 0.003 to 100 μm, the ratio of the pore volume of pores with a pore diameter of 4 μm or less to the pore volume of all pores was calculated based on the pore volume distribution measured by mercury intrusion. The results were 4%, 10%, and 31% in Examples 1, 2, and 3, respectively. The ratio was 40% in Comparative Example 1. Therefore, it was confirmed that in the polymer absorbent, the ratio of the pore volume of pores with a pore diameter of 4 μm or less in the pore distribution in the range of pore diameters of 0.003 to 100 μm was less than 40% of the pore volume of all pores.

[0188] (4) Ratio of pore volume of pores with a pore diameter of 1 μm or more

[0189] In the pore distribution in the range of pore diameters of 0.003 to 100 μm, the ratio of the pore volume of pores with a pore diameter of 1 μm or more to the pore volume of all pores was calculated based on the pore volume distribution measured by mercury intrusion. The results were 99.7%, 99.9%, and 99.6% in Examples 1, 2, and 3, respectively. The ratio was 65% in Comparative Example 1. Therefore, it was confirmed that in the polymer absorbent, the ratio of the pore volume of pores with a pore diameter of 1 μm or more in the pore distribution in the range of pore diameters of 0.003 to 100 μm was 90% or more of the pore volume of all pores.

[0190] (5) Blood preservation rate

[0191] The blood retention rate (1 minute) (g / g) was measured by the above-mentioned blood retention rate measurement method. The results are shown in Table 1, and a representative graph is shown in Figure 7 .in, Figure 7It is a graph showing the relationship between the blood retention rate (g / g) and the blood absorption time (minutes). The vertical axis represents the blood retention rate (g / g) of each absorbent, and the horizontal axis represents the blood absorption time (minutes) in each absorbent. The thick solid line and circle are Example 1, the thin solid line and triangle are Comparative Example 1, and the dotted line and diamond are Comparative Example 2. It was confirmed that: compared with the Infinity granules (Comparative Example 1) and the super absorbent polymer (Comparative Example 2), the polymer absorbent (Example 1) absorbs a large amount of blood quickly and sharply in the initial stage. It should be noted that, although not shown in the figure, the pulp fiber also has roughly the same tendency as Comparative Example 2. Moreover, in Examples 1, 2, and 3, the blood retention rate (1 minute) is 7.4 g / g, 8.1 g / g, and 10.4 g / g, respectively. In Comparative Examples 1 and 2, it is 5.5 g / g, respectively. Therefore, it is confirmed that the 1-minute value of the blood retention rate of the polymer absorbent is 6.5 g / g or more. The above results are shown in Table 1.

[0192] [Table 1]

[0193] Example 1 Example 2 Example 3 Comparative Example 1 7μm or less (%) 11 36 45 47 53μm or more (%) 14 6 3 3 4μm or less (%) 4 10 31 40 1μm or more (%) 99.7 99.9 99.6 65 Blood preservation rate (1 minute) (g / g) 7.4 8.1 10.4 5.5

[0194] It should be noted that the composite absorbent of the present invention can be applied to various sanitary products such as belt-type disposable diapers, sanitary napkins, absorbent pads, absorbent pads (such as incontinence pads, bedsore pads, postpartum pads, etc.), absorbent sheets, breast milk pads, disposable diapers for pets, absorbent pads for pets, excrement disposal sheets for pets, wet sheets, wet wipes, cosmetic wipes, masks, etc., in addition to the pants-type disposable diapers of the above-mentioned embodiments. Therefore, the body fluid as the absorption target liquid of the composite absorbent is the liquid discharged from the wearer of the sanitary product, and examples thereof include urine, sweat, feces, menstrual blood, leucorrhea, breast milk, blood, exudate, etc.

[0195] The present invention is not limited to the above-described embodiments and the like, and appropriate combinations, substitutions, changes and the like may be made without departing from the purpose and spirit of the present invention.

[0196] Description of Reference Numerals

[0197] 1. Sanitary napkins

[0198] 2 Surface sheet

[0199] 3 Back sheet

[0200] 4 Composite absorber

Claims

1. A composite absorbent body, which is a composite absorbent body for sanitary products for absorbing blood, The invention comprises at least one of a highly water-absorbent polymer and pulp fibers and a high molecular absorbent having a hydrophilic continuous skeleton and continuous pores. In the above-mentioned polymer absorbent, in the pore distribution representing the relationship between the pore diameter and the pore volume in the range of pore diameter of 0.003 to 100 μm, the proportion of the pore volume becomes the largest in the range of the maximum volume pore diameter of 1 to 95 μm, and the proportion of the pore volume of pores with a pore diameter of less than 7 μm is less than 46% of the pore volume of all pores.

2. The composite absorbent body according to claim 1, wherein: The one-minute value of the blood retention rate of the polymer absorbent is 6.5 g / g or more.

3. The composite absorbent according to claim 1 or 2, wherein: In the polymer absorbent, the ratio of the pore volume of pores having a pore diameter of 53 μm or more in the pore distribution is less than 29% of the pore volume of all pores.

4. The composite absorbent according to any one of claims 1 to 3, wherein In the polymer absorbent, the ratio of the pore volume of pores having a pore diameter of 4 μm or less in the pore distribution is less than 40% of the pore volume of all pores.

5. The composite absorbent according to any one of claims 1 to 4, wherein In the polymer absorbent, the ratio of the pore volume of pores having a pore diameter of 1 μm or more accounts for 90% or more of the pore volume of all pores.

6. The composite absorbent according to any one of claims 1 to 5, wherein The continuous skeleton of the polymer absorbent has a hydrophilic group.

7. The composite absorbent according to any one of claims 1 to 6, wherein The hydrophilic group has a property of absorbing blood and becoming negatively charged.

8. The composite absorbent body according to any one of claims 1 to 7, comprising the pulp fibers.

9. The composite absorbent according to any one of claims 1 to 8, wherein The composite absorbent body has a length direction and a width direction that are orthogonal to each other. The composite absorbent body includes a pair of linear high-density portions, the pair of high-density portions extending along the longitudinal direction or the width direction and arranged at intervals in the width direction or the longitudinal direction. The polymer absorbent is located between one and the other of the pair of high-density portions in the width direction or the length direction.

10. The composite absorbent according to any one of claims 1 to 8, wherein The composite absorbent body has a length direction and a width direction that are orthogonal to each other. The composite absorbent body includes a pair of linear high-density portions, the pair of high-density portions extending along the longitudinal direction or the width direction and arranged at intervals in the width direction or the longitudinal direction. The polymer absorbent is located outside each of the pair of high-density portions in the width direction or the length direction.

11. The composite absorbent according to any one of claims 1 to 10, wherein The polymer absorbent is a monolithic absorbent. 12 . A sanitary product comprising a top sheet, a back sheet, and the composite absorbent body according to claim 1 , located between the top sheet and the back sheet.

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