Absorbent article

Abstract

To provide an absorbent article that has excellent absorptivity and is thus less apt to cause re-wetting.SOLUTION: The absorbent article of the present invention includes an absorbent body that contains a highly absorbent polymer and is for absorbing blood. The absorbent article contains an osmotic pressure regulator for regulating the osmotic pressure of the hemocyte component in the blood.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to absorbent articles.

Background Art

[0002] In absorbent articles such as sanitary napkins and panty liners, those containing a component for modifying excreted liquid are known for the purpose of preventing leakage of excreted liquid such as menstrual blood and improving absorption performance. For example, Patent Document 1 discloses an absorbent article including an absorbent core and a liquid-permeable sheet containing a blood aggregating agent.

[0003] Generally, when the absorbent of an absorbent article contains a superabsorbent polymer (SAP), although the SAP absorbs the liquid component in blood when absorbing blood, it cannot absorb blood cell components such as red blood cells. Therefore, such blood cell components adhere to cover the surface of the SAP, which may inhibit the permeation and absorption of blood, and as a result, the absorption rate of the absorbent article may decrease. However, in the absorbent article disclosed in Patent Document 1, it is said that the blood aggregating agent aggregates the blood cell components in blood, suppressing the surface of the SAP from being covered with blood cell components and maintaining a predetermined absorption performance.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the absorbent article of Patent Document 1, since the blood aggregating agent is composed of a cationic polymer having a weight average molecular weight of 150,000 or more and has low solubility, it takes time to react with the blood cell components in blood, and it cannot sufficiently suppress the adhesion of blood cell components to cover the surface of the SAP. As a result, there is a fear that the absorption performance of the absorbent article cannot be sufficiently improved. Furthermore, if the surface of the SAP becomes covered with blood cell components in this way, there is a risk that menstrual blood and other excretory fluids that reach the absorbent material may not be absorbed by the SAP but instead flow back to the skin-facing side of the surface sheet (i.e., rewetting).

[0006] This invention has been made in view of these problems, and aims to provide an absorbent article with excellent absorption performance, and consequently an absorbent article that is less prone to rewetting. [Means for solving the problem]

[0007] One aspect of the present invention (Aspect 1) is an absorbent article comprising an absorbent material for absorbing blood, which includes a superabsorbent polymer, and is characterized by containing an osmotic pressure adjusting agent for adjusting the osmotic pressure of blood cell components in the blood.

[0008] In the absorbent article of this embodiment 1, the osmotic pressure adjusting agent adjusts the osmotic pressure of blood cell components (blood cells such as red blood cells, white blood cells, and platelets) in the blood, causing the blood cell components to dehydrate, shrink, and deform, making it difficult for blood cell components attached to the SAP surface to stick together. This ensures that a passage for liquid is secured between the blood cell components, and promotes liquid migration to the SAP (hereinafter, this effect will be referred to as the "inhibitory effect of inhibiting the binding of blood cell components"). As a result, the absorbent article of this embodiment 1 does not easily inhibit the permeation or absorption of excreted blood, and can therefore exhibit excellent absorbency performance as an absorbent article, and can also be less prone to rewetting.

[0009] Furthermore, in another aspect of the present invention (Aspect 2), the absorbent article of Aspect 1 is characterized in that the osmotic pressure adjusting agent has a solubility of 8 g / 100 g or more in 100 g of ion-exchanged water at 25°C.

[0010] The absorbent article of this embodiment 2 has an osmotic pressure adjusting agent with a certain level of solubility, and can more reliably adjust the osmotic pressure of blood cell components in the blood, thereby more reliably exerting the aforementioned inhibitory effect on the binding of blood cell components. As a result, the absorbent article of this embodiment 2 can more reliably exhibit the excellent absorption performance described above, and rewetting can also be made less likely to occur.

[0011] In yet another aspect of the present invention (Aspect 3), the absorbent article of Aspect 2 is characterized in that its solubility in 100 g of ion-exchanged water at 25°C is in the range of 10 g / 100 g or more and 72 g / 100 g or less.

[0012] In this embodiment 3, the absorbent article contains an osmotic pressure adjusting agent with solubility within a specific range, thereby enabling it to more reliably exert the aforementioned inhibitory effect on the binding of blood cell components. Furthermore, because osmotic regulators with such specific solubility tend to remain in the system after absorbing the first menstrual blood (blood), the remaining osmotic regulator can exert the aforementioned inhibitory effect on the binding of blood cell components even during repeated absorption of menstrual blood from the second time onward. As a result, the absorbent article of this embodiment 3 can more reliably exhibit the excellent absorption performance described above over a long period of time.

[0013] In yet another aspect of the present invention (Aspect 4), the absorbent article according to any of the above aspects 1 to 3 is characterized in that the osmotic pressure adjusting agent includes an uncharged component.

[0014] The absorbent article of this embodiment 4 contains an osmotic pressure adjusting agent that is uncharged, and therefore can exert the above-mentioned inhibitory effect on the binding of blood cell components more effectively. As a result, the absorbent article of this embodiment 4 can exhibit even better absorption performance.

[0015] In yet another aspect of the present invention (Aspect 5), the absorbent article according to any of the above aspects 1 to 4 is characterized in that the osmotic pressure adjusting agent contains at least one component selected from the group consisting of neutral zwitterions, sugars, and polyhydric alcohols.

[0016] Since the absorbent article of Embodiment 5 contains the above specific components in the osmotic pressure regulator, the above-described inhibitory action on the joining of blood cell components can be more effectively exerted. As a result, the absorbent article of Embodiment 5 can exhibit further excellent absorption performance.

[0017] In yet another aspect (Aspect 6) of the present invention, in the absorbent article of any one of the above Aspects 1 to 5, the osmotic pressure regulator contains glycine.

[0018] Since the absorbent article of Embodiment 6 contains glycine in the osmotic pressure regulator, the above-described inhibitory action on the joining of blood cell components can be more effectively and repeatedly exerted. As a result, the absorbent article of Embodiment 6 can exhibit more excellent absorption performance over a long period of time.

[0019] In yet another aspect (Aspect 7) of the present invention, in the absorbent article of any one of the above Aspects 1 to 6, the osmotic pressure regulator is contained at 0.50 Osm / L or more.

[0020] Since the absorbent article of Embodiment 7 contains the osmotic pressure regulator at the above specific concentration, the above-described inhibitory action on the joining of blood cell components can be more accurately exerted. As a result, the absorbent article of Embodiment 7 can exhibit even more excellent absorption performance.

[0021] In yet another aspect (Aspect 8) of the present invention, in the absorbent article of any one of the above Aspects 1 to 7, the osmotic pressure regulator is disposed at a position on the side facing the skin with respect to the absorber or the absorber.

[0022] In the absorbent article of Embodiment 8, since the osmotic pressure regulator is disposed at a position on the side facing the skin with respect to the absorber or the absorber, menstrual blood (blood) is more likely to come into contact with the osmotic pressure regulator before reaching the SAP. Therefore, the above-described inhibitory action on the joining of blood cell components can be exerted more reliably and effectively.

[0023] In yet another aspect of the present invention (Aspect 9), the absorbent article of Aspect 8 is characterized in that the osmotic pressure adjusting agent is arranged in the absorbent body.

[0024] In this embodiment 9, since the osmotic pressure adjusting agent is arranged in the absorbent material, the above-mentioned inhibitory effect on the binding of blood cell components can be exerted more reliably and effectively.

[0025] Furthermore, in yet another aspect of the present invention (Aspect 10), in the absorbent article of the above aspect 9, the absorbent body includes an absorbent core containing the superabsorbent polymer and a core wrap sheet located on the skin-facing side of the absorbent core, The osmotic pressure adjusting agent is characterized by being arranged on the core wrap sheet.

[0026] In this embodiment 10, the absorbent article has the osmotic pressure adjusting agent positioned on a core wrap sheet located on the skin-facing side of the absorbent core in the absorbent body. This allows menstrual blood (blood) to come into contact with the osmotic pressure adjusting agent more reliably than SAP, thus enabling the aforementioned inhibitory effect on the binding of blood cell components to be exerted more reliably and effectively. [Effects of the Invention]

[0027] According to the present invention, it is possible to provide an absorbent article with excellent absorption performance, and consequently, an absorbent article that is less prone to rewetting. [Brief explanation of the drawing]

[0028] [Figure 1] Figure 1 is a schematic plan view of a sanitary napkin 1 in an unfolded state according to one embodiment of the present invention. [Figure 2] Figure 2 shows magnified images (magnification 2000x) of blood cell components in horse blood. (a) is a magnified image of blood cell components without the addition of an osmotic regulator, and (b) is a magnified image of blood cell components with betaine added as an osmotic regulator. [Modes for carrying out the invention]

[0029] Hereinafter, a sanitary napkin 1, which is a preferred embodiment of the absorbent article of the present invention, will be described in detail with reference to the drawings.

[0030] In this specification, unless otherwise specified, "viewing an object (e.g., a sanitary napkin, absorbent material, etc.) placed on a horizontal surface in an unfolded state, from the vertically upward side (or the surface sheet side if the object is an absorbent material) in the direction of the object's thickness" is simply referred to as "planar view." Furthermore, in this specification, unless otherwise specified, in the thickness direction of the sanitary napkin 1, the side that is relatively proximal to the wearer's skin when the sanitary napkin 1 is worn is referred to as the "skin-facing side," and the side that is relatively distal to the wearer's skin when the sanitary napkin 1 is worn is referred to as the "non-skin-facing side."

[0031] [Sanitary napkins] Figure 1 is a schematic plan view of a sanitary napkin 1 in an unfolded state according to one embodiment of the present invention. As shown in Figure 1, the sanitary napkin 1 has a vertically elongated shape in a plan view, with a longitudinal direction L and a width direction W, and two longitudinal edges that project outward in an arc shape in the longitudinal direction. However, the external shape of the sanitary napkin 1 is not limited to this configuration, and any shape (for example, oval, rectangular, hourglass shape, etc.) can be adopted depending on the various uses and modes of use.

[0032] The sanitary napkin 1 has as its basic structure a liquid-permeable surface sheet 2 that forms the skin-facing side of the sanitary napkin 1 in the thickness direction, a back sheet 3 that forms the non-skin-facing side of the sanitary napkin 1, and an absorbent core 4 located between these sheets. Furthermore, the sanitary napkin 1 includes a pair of side sheets 5, 5 positioned on the skin-facing side of the surface sheet 2, located at both ends in the width direction W of the sanitary napkin 1 and extending in the longitudinal direction L, with the inner ends in the width direction W standing up when the sanitary napkin 1 is worn to form a leak-proof wall, and an adhesive portion (not shown) positioned on the non-skin-facing surface of the back sheet 3, which adheres and fixes the sanitary napkin 1 to the inner surface of the wearer's underwear or other clothing.

[0033] However, the sanitary napkin 1 is not limited to this configuration; for example, it does not have to include the pair of side sheets 5, 5 described above.

[0034] In the aforementioned sanitary napkin 1, the absorbent material 4 is located between the surface sheet 2 and the back sheet 3 and is formed of an absorbent material capable of absorbing bodily fluids containing blood, such as menstrual blood, that are discharged from the wearer and permeate through the surface sheet 2. This absorbent material 4 contains a superabsorbent polymer (SAP) and an osmotic pressure adjusting agent that adjusts the osmotic pressure of blood cell components in the blood.

[0035] Such osmotic regulators adjust the osmotic pressure of blood cell components (red blood cells, white blood cells, platelets, etc.) in the blood, causing them to dehydrate, shrink, and deform (i.e., shrink and deform the blood cell components). This makes it difficult for blood cell components attached to the SAP surface to stick together, and a pathway for blood to pass between them is secured, thereby promoting liquid migration to the SAP (i.e., exerting an inhibitory effect on the binding of blood cell components). Sanitary napkin 1, by having the osmotic pressure adjusting agent placed in the absorbent material 4, can exert the aforementioned inhibitory effect on the binding of blood cell components more reliably and effectively.

[0036] In addition, in the absorbent article of the present invention, the placement of the osmotic pressure adjusting agent is not limited to the absorbent body. The osmotic pressure adjusting agent may be placed in a position on the skin-facing side of the absorbent body (e.g., on the surface sheet) or in a position on the non-skin-facing side of the absorbent body (e.g., on the back sheet). However, it is preferable that the osmotic pressure regulator is positioned on the skin-facing side of the absorbent or on the absorbent side. When the osmotic pressure regulator is positioned in this way, menstrual blood (blood) is more likely to come into contact with the osmotic pressure regulator before the SAP, thereby allowing the aforementioned inhibitory effect on the binding of blood cell components to be exerted more reliably and effectively.

[0037] The basic components of the absorbent article of the present invention will be described in more detail below, using the sanitary napkin 1 described above.

[0038] (Surface sheet) In the sanitary napkin 1 described above, the surface sheet 2, as shown in Figure 1, has a vertically elongated shape that extends from one edge to the other edge in the longitudinal direction L of the sanitary napkin 1 in a plan view, and also extends from near one edge to near the other edge in the width direction W of the sanitary napkin 1. This surface sheet 2 is positioned on the skin-facing side in the thickness direction of the sanitary napkin 1 and is composed of a liquid-permeable sheet-like member that forms a contact surface that can come into contact with the wearer's skin, i.e., the skin-facing surface of the sanitary napkin 1.

[0039] Furthermore, as shown in Figure 1, the surface sheet 2 is slightly larger in the longitudinal direction L and width direction W compared to the absorbent 4 which is located on the non-skin-facing side of the surface sheet 2, and is joined to the back sheet 3 located on the non-skin-facing side at its peripheral edge.

[0040] In this invention, the external shape, various dimensions, basis weight, etc. of the surface sheet are not particularly limited as long as they can be used as a surface sheet for an absorbent article, and any external shape, various dimensions, basis weight, etc. can be adopted according to the desired liquid permeability, texture, flexibility, strength, etc.

[0041] (Backside sheet) In the sanitary napkin 1 described above, the backing sheet 3 has a vertically elongated shape, extending from one edge to the other in the longitudinal direction L of the sanitary napkin 1 when viewed from above, and also extending from one edge to the other in the width direction W of the sanitary napkin 1. This backing sheet 3 is positioned on the non-skin-facing side in the thickness direction of the sanitary napkin 1, forming the non-skin-facing surface of the sanitary napkin 1, and is composed of a liquid-impermeable sheet-like member that prevents bodily fluids containing blood, such as menstrual blood, that have permeated the absorbent material 4 from leaking out of the sanitary napkin 1.

[0042] In this invention, the external shape, various dimensions, basis weight, etc. of the backing sheet are not particularly limited as long as they can be used as a backing sheet for an absorbent article, and any external shape, various dimensions, basis weight, etc. can be adopted according to the desired leak-proof performance, breathability, strength, etc.

[0043] (Absorbent) As shown in Figure 1, in the sanitary napkin 1 described above, the absorbent material 4, in a plan view, extends over a wide area in the longitudinal direction L, from near one edge to near the other edge, centered on the central part of the longitudinal direction L and width direction W of the sanitary napkin 1, and also extends over a wide area in the width direction W, from near one edge to near the other edge, and furthermore, has an elongated outer shape with two longitudinal edges that protrude outward in an arc shape in the longitudinal direction.

[0044] More specifically, the absorber 4 has a constricted portion in the longitudinal center when viewed from above, which is relatively smaller in width compared to other parts. Furthermore, this constricted portion has a minimum width portion, which is the minimum width of the absorber 4, and a maximum width portion, which is the maximum width of the absorber 4, located on the longitudinal outer side of the constricted portion.

[0045] The absorbent material 4 is positioned between the surface sheet 2 and the back sheet 3 in the thickness direction of the sanitary napkin 1 and is formed of a predetermined absorbent material that can absorb and retain bodily fluids, including menstrual blood, that have permeated through the surface sheet 2.

[0046] In the sanitary napkin 1 described above, the absorbent material 4 is joined to the surface sheet 2 and the back sheet 3, respectively, by any adhesive such as a hot-melt adhesive.

[0047] The absorbent material 4, as described above, contains a superabsorbent polymer and an osmotic pressure regulator that adjusts the osmotic pressure of blood cell components in the blood. The osmotic pressure regulator will be described later, but the superabsorbent polymer is a powder or granular material made of a superabsorbent polymer such as sodium acrylate copolymer, which is known in this field, and is called SAP (Super Absorbent Polymer).

[0048] Specific examples of superabsorbent polymers include polymers or copolymers of (meth)acrylic acid or alkali metal salts of (meth)acrylic acid, preferably polymers or copolymers of sodium (meth)acrylate. In this specification, (meth)acrylic acid means acrylic acid or methacrylic acid.

[0049] Furthermore, the absorbent material 4 may contain only the osmotic pressure adjusting agent and superabsorbent polymer mentioned above, or it may also contain other water-absorbing materials known in the art. Examples of such water-absorbing materials include hydrophilic fibers, and more specifically, pulp fibers (e.g., crushed pulp), cotton, rayon, acetate, and other cellulose fibers. As stated above, in the absorbent article of the present invention, the osmotic pressure adjusting agent does not need to be included in the absorbent body. In such cases, the absorbent body may contain only the superabsorbent polymer, or it may contain the superabsorbent polymer and the water-absorbing material mentioned above.

[0050] Furthermore, in the sanitary napkin 1 described above, the absorbent body 4 may have a structure in which an absorbent core composed of such an osmotic pressure adjusting agent, a superabsorbent polymer, and an arbitrary water-absorbing material is covered with a core wrap sheet such as hydrophilic tissue, and the osmotic pressure adjusting agent may also be contained within such a core wrap sheet. For example, if the absorbent 4 includes an absorbent core containing a superabsorbent polymer and a core wrap sheet located on the skin-facing side of the absorbent core, and the osmotic pressure regulator is placed on the core wrap sheet (for example, on the non-skin-facing side of the core wrap sheet located on the skin-facing side of the absorbent core), then by placing the osmotic pressure regulator on the core wrap sheet located on the skin-facing side of the absorbent core in the absorbent, menstrual blood (blood) can be more reliably brought into contact with the osmotic pressure regulator before the SAP, thereby allowing the aforementioned inhibitory effect on the binding of blood cell components to be exerted more reliably and effectively.

[0051] In this invention, the external shape, various dimensions, basis weight, etc. of the absorbent are not particularly limited as long as they do not hinder the effects of the present invention, and any external shape, various dimensions, basis weight, etc. can be adopted according to the desired water absorption, flexibility, strength, etc.

[0052] The osmotic pressure adjusting agent used in the absorbent article of the present invention will be described in more detail below.

[0053] [Osmotic pressure regulator] Osmotic regulators are not particularly limited as long as they have an osmotic regulator effect, which is to adjust the osmotic pressure of blood cell components (blood cells such as red blood cells, white blood cells, and platelets) in the blood. For example, chemical substances called osmolytes can be mentioned, and more specifically, neutral zwitterions, sugars, polyhydric alcohols, methylammonium compounds, sulfonium compounds, and cyclic carboxylic acid esters (e.g., glucuronolactone) can be mentioned.

[0054] Such osmotic regulators can dehydrate and shrink blood cell components in the blood through their osmotic action. As a result, the blood cell components in the blood shrink and deform unevenly, making it difficult for blood cell components attached to the surface of the superabsorbent polymer (SAP) to adhere to each other. It is known that red blood cells, one of the blood cell components, change their morphology due to changes in osmotic pressure and pH, mechanical stress, etc., making it difficult for them to adhere to each other and form aggregates.

[0055] Here, Figure 2 shows a photograph of blood cell components in horse blood (blood) and watery egg white mixed in a 50:50 mass ratio, observed under a microscope at 2000x magnification. In Figure 2, (a) is a magnified photograph of blood cell components (red blood cells) without the addition of an osmotic regulator, and (b) is a magnified photograph of blood cell components with 5% by mass of betaine added as an osmotic regulator (osmolarity (osmotic pressure) equivalent: 0.84 Osm / L). As shown in the magnified photograph in Figure 2, it can be seen that in blood to which betaine has been added as an osmotic pressure regulator, the blood cell components in the blood have contracted due to dehydration, resulting in uneven reduction and deformation.

[0056] In the present invention, the osmotic pressure regulator is not particularly limited as long as it has an osmotic pressure regulating effect as described above, but it is preferable that it contains at least one component selected from the group consisting of neutral zwitterions, sugars, and polyhydric alcohols. When the osmotic pressure regulator contains such specific components, the above-mentioned inhibitory effect on the binding of blood cell components can be exerted more effectively.

[0057] Here, the neutral zwitterions that can be used as osmotic regulators are not particularly limited as long as they have the osmotic regulator effect described above, but examples include amino acids such as taurine, betaine, serine, glycine, glycylglycine, tricine, L-phenylalanine, creatine, and arginine, as well as sulfobetaine. These zwitterions may be used individually or in combination of two or more. Among these zwitterions, it is preferable to use amino acids with relatively small molecular weights, such as glycine (molecular weight 75), serine (molecular weight 105), and betaine (molecular weight 117), because they can increase osmotic pressure even with small additions.

[0058] Furthermore, the sugars that can be used as osmotic regulators are not particularly limited as long as they have the osmotic regulating effect described above, but examples include monosaccharides such as glucose, fructose, galactose, mannose, xylose, and erythrose, and disaccharides such as sucrose. These sugars may be used individually or in combination of two or more. Among these sugars, it is preferable to use sugars with four or more carbon atoms, such as glucose, fructose, galactose, mannose, xylose, erythrose, and sucrose, due to the ease with which the above-mentioned osmotic pressure regulating effect can be obtained.

[0059] Furthermore, the polyhydric alcohols that can be used as osmotic pressure regulators are not particularly limited as long as they have the osmotic pressure regulating effect described above, but examples include sugar alcohols such as sorbitol, mannitol, xylitol, and erythritol, cyclitols such as inositol, and lower alcohols such as propylene glycol. These polyhydric alcohols may be used individually or in combination of two or more. Among these polyhydric alcohols, it is preferable to use polyhydric alcohols with four or more carbon atoms, such as sorbitol, mannitol, xylitol, erythritol, and inositol, due to their ease of obtaining the osmotic pressure regulating effect described above.

[0060] Furthermore, in the present invention, it is preferable that the osmotic pressure adjusting agent has a solubility of 8 g / 100 g or more in 100 g of ion-exchanged water at 25°C. Examples of osmotic pressure adjusting agents having such solubility include taurine, betaine, serine, glycine, glycylglycine, tricine, glucose, fructose, galactose, mannose, xylose, erythritol, sorbitol, mannitol, xylitol, and erythritol. When an osmotic pressure adjusting agent has such a certain level of solubility, it dissolves easily in the blood, allowing for more reliable adjustment of the osmotic pressure of blood cell components, and thus more reliably exerting the aforementioned inhibitory effect on the binding of blood cell components. Furthermore, the solubility of the osmotic pressure regulator in 100g of ion-exchanged water at 25°C is more preferably 10g / 100g or more, and even more preferably 25g / 100g or more. In addition, the solubility of the osmotic pressure regulator in 100g of ion-exchanged water at 25°C is more preferably 72g / 100g or less, and even more preferably 36g / 100g or less. In particular, if the solubility of the osmotic regulator in 100g of ion-exchanged water at 25°C is within the range of 10g / 100g to 72g / 100g, the aforementioned inhibitory effect on the aggregation of blood cell components can be exerted even more reliably. Furthermore, since an osmotic regulator with such specific solubility tends to remain in a certain amount after absorbing the first menstrual blood (blood), the remaining osmotic regulator can exert the aforementioned inhibitory effect on the aggregation of blood cell components even during repeated absorption of menstrual blood from the second time onward. Therefore, absorbent articles containing an osmotic regulator with such specific solubility can more reliably exhibit the excellent absorption performance described above over a long period of time.

[0061] Furthermore, in the present invention, it is preferable that the osmotic pressure regulator contains an uncharged component. An uncharged component means a component that does not have an imbalance of positive or negative charges. Examples of such components include taurine, betaine, serine, glycine, glycylglycine, tricine, glucose, fructose, galactose, mannose, xylose, erythritol, sorbitol, mannitol, xylitol, and erythritol. When the osmotic pressure regulator contains such an uncharged component, the aforementioned inhibitory effect on the binding of blood cell components can be exerted more effectively. Among the above components, those containing glycine are particularly preferred. When the osmotic pressure regulator contains glycine, the aforementioned inhibitory effect on the binding of blood cell components can be exerted more effectively and repeatedly. Therefore, absorbent articles containing such osmotic pressure regulators can exhibit superior absorption performance over a longer period of time.

[0062] Furthermore, in the present invention, it is preferable that the osmotic pressure regulator is included at a concentration (osmolality; osmotic pressure) of 0.50 Osm / L or higher. When the osmotic pressure regulator is included at such a specific concentration, the aforementioned inhibitory effect on the binding of blood cell components can be exerted more effectively. Furthermore, it is more preferable that the osmotic pressure adjusting agent is included at a concentration of 0.70 Osm / L or higher. There is no particular upper limit to the concentration of the osmotic pressure adjusting agent; for example, a concentration of 1.30 Osm / L or lower is acceptable.

[0063] The concentration of the osmotic regulator (Osm / L) can be determined by dividing the amount of the osmotic regulator added (mol) by the plasma volume (L). Here, the plasma volume (L) can be determined by multiplying the blood volume (L) by 0.55.

[0064] The absorbent article of the present invention is not particularly limited as long as it can absorb blood such as menstrual blood, and can be applied to absorbent articles such as panty liners and absorbent pads, in addition to the sanitary napkins of the above-described embodiment.

[0065] Furthermore, the present invention is not limited to the embodiments described above or the following examples, and can be appropriately combined, substituted, or modified without departing from the purpose and spirit of the present invention. [Examples]

[0066] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0067] As additives included in absorbent articles along with superabsorbent polymers (SAP), several types of osmotic pressure regulators shown in Tables 1 and 2 below were used. The blood retention ratio of SAP to horse blood, as described later, was measured to evaluate the inhibitory effect of each additive (osmotic pressure regulator) on the binding of blood cell components. Furthermore, the absorption rate and rewetting amount were measured when each additive (osmotic pressure regulator) was applied to the absorbent material of an absorbent article (sanitary napkin) (Examples 1-21). Furthermore, each additive in Comparative Examples 1 to 5 was evaluated in the same manner as in the above-described examples, except that several types of chemical substances shown in Table 2 below were used as additives instead of osmotic pressure regulators. Comparative Example 6 is an example without any additives. The evaluation results for each additive are shown in Tables 1 and 2 below.

[0068] The method for measuring the blood retention ratio of SAP to horse blood is as follows:

[0069] <Method for measuring the blood retention ratio of SAP to horse blood> (1) Using a water bath set to 37°C, the defibroused horse blood (Japan Bioceam Co., Ltd.; hereinafter referred to as "defibroused horse blood") to which additives (e.g., osmotic pressure regulators, etc.) have been added is heated to 37°C. The amount of additives added shall be 10% by mass relative to the mass of the defibroused horse blood. (2) Cut a 500μm mesh nylon mesh (AS ONE Corporation, 2-9566-03 Nylon Mesh 500μm) into 10cm x 10cm pieces. (3) Measure the initial mass (g) of the filter paper (ADVANTEC No.2 100mm x 100mm). (4) Weigh out 0.05g of SAP and place it in an aluminum foil cup (aluminum foil cup No. 6, bottom diameter: 35mm). (5) Slowly invert and mix the warmed defibroused horse blood, then draw up approximately 2 mL using a 5 mL micropipette and place it in the aluminum foil cup mentioned above. At this time, measure the mass (g) of the defibroused horse blood placed in the aluminum foil cup. (6) Place the defibroused horse blood into the aluminum foil cup and immediately start the stopwatch. Using a spatula, thoroughly mix the defibroused horse blood and SAP for 1 minute. (7) Ten minutes after starting the stopwatch, spread out the sides of the aluminum foil cup to flatten it, and then layer the nylon mesh, filter paper, and 3.5 kg weight (100 mm x 100 mm) on top of it in that order. (8) After 3 minutes have elapsed since placing the 3.5 kg weight on the filter paper, remove the 3.5 kg weight and the filter paper, and measure the mass (g) of the filter paper after horse blood absorption. (9) The mass (g) of the filter paper after horse blood absorption measured in (7) above is subtracted from the initial mass (g) of the filter paper measured in (3) above to obtain the mass (g) of defibroused horse blood that was not absorbed by the SAP. Furthermore, the mass (g) of defibroused horse blood that was not absorbed by the SAP is subtracted from the mass (g) of defibroused horse blood placed in the aluminum foil cup measured in (5) above to obtain the mass of defibroused horse blood absorbed by the SAP, i.e., the amount of horse blood absorbed by the SAP (g). Then, by dividing the amount of horse blood absorbed by the SAP (g) by the mass of the SAP weighed in (4) above, i.e., 0.05 g, the blood retention ratio of the SAP to horse blood (g / g) is obtained.

[0070] Furthermore, the absorption rate and rewetting amount when each additive (osmotic pressure regulator) is applied to the absorbent material of an absorbent article (sanitary napkin) can be measured according to the following <Method for manufacturing product samples of sanitary napkins> and <Method for measuring the absorption rate and rewetting amount of absorbent articles>.

[0071] <Manufacturing method for product samples of sanitary napkins> Hydrophilic tissue, 14g / m² 2 One surface of the core wrap sheet, which consists of [material], is coated with 5g / m² of hot melt adhesive (HMA). 2 Place 0.34g of the additive (osmotic pressure regulator) through the filter (place it in a 50mm x 30mm area centered on the dropping area). Next, SAP 50g / m 2 and pulp 200g / m 2 An absorbent body is obtained by wrapping the entire absorbent core, which is made by mixing the substances, with the core wrap sheet, covering the surface of one side that faces the skin. At this time, the absorbent core is covered so that each of the additives (osmotic pressure regulators) placed on the core wrap sheet faces inward (i.e., facing the absorbent core), so that each of the additives (osmotic pressure regulators) is positioned on the non-skin-facing side of the core wrap sheet, which is located on the skin-facing side of the absorbent core. And, air-through nonwoven fabric 30g / m 2 The surface sheet consists of a 30g / m² air-through nonwoven fabric. 2 The second sheet consists of the above absorbent material and a resin film of 23.5 g / m². 2 The backing sheet, consisting of the above, is layered in this order, joined together with HMA, and then cut into a predetermined sanitary napkin shape to obtain a product sample of a sanitary napkin.

[0072] <Method for measuring absorption rate and rewetting amount> (1) Using a water bath, heat the bottle containing defibroused horse blood (Japan Bioceam Co., Ltd.) until it reaches 37°C. (2) Place the perforated acrylic jig on top of the product sample of the sanitary napkin. (3) Measure the initial mass A (g) of the filter paper (50mm x 35mm) (approximately 2g). (4) After gently shaking the bottle containing the defibroused horse blood up and down to mix it, measure out 3 mL of the defibroused horse blood with a micropipette and inject it over approximately 2 seconds from a position 5 mm above the perforated acrylic jig mentioned above. (5) Measure the time (in seconds) from when you start injecting defibroused horse blood until the liquid (defibroused horse blood) on the surface sheet disappears, and define this measured time as the first absorption rate (in seconds). (6) After injecting the liquid, let it stand for 30 seconds. (7) Dispense 3 mL of defibroused horse blood using a micropipette, inject it in the same manner as in (4), measure the time (seconds) until the liquid on the surface sheet disappears, and define this measured time as the second absorption rate (seconds). (8) After the liquid has been absorbed, remove the perforated acrylic jig. (9) Six minutes after injecting the second liquid, place a piece of filter paper around the area where the liquid was dropped, then place a weight (50mm x 35mm, 525g) on ​​top of the filter paper and leave it to stand. (10) After 1 minute, place the filter paper and weight on top of the paper, remove the filter paper and weight, and measure the mass B (g) of the filter paper after it has absorbed the liquid. (11) The amount of liquid (defibrozed horse blood) absorbed by the filter paper is calculated by subtracting the initial mass A (g) from the mass B (g) of the filter paper after liquid absorption, and this amount is taken as the rewetting amount (g).

[0073] [Table 1]

[0074] [Table 2]

[0075] As shown in Tables 1 and 2, the absorbents of Examples 1 to 21, which contained osmotic pressure regulators, were found to have a high blood retention ratio for horse blood, excellent absorption performance, and very low rewetting. In particular, the absorbents of Examples 1 to 6, 10 to 14, 16, and 19 had a very high blood retention ratio of 20 g / g or more, and were found to have particularly excellent absorption performance. [Explanation of symbols]

[0076] 1. Sanitary napkin 2. Surface sheet 3. Back sheet 4 Absorbent

Claims

1. An absorbent article comprising an absorbent material for absorbing blood, which includes a superabsorbent polymer, It contains an osmotic regulator that adjusts the osmotic pressure of blood cell components in the blood, The absorbent article is characterized in that the osmotic pressure adjusting agent contains at least one component selected from the group consisting of a neutral zwitterion with a molecular weight of 179 or less, sugars having 4 or more carbon atoms, and polyhydric alcohols having 4 or more carbon atoms.

2. The absorbent article according to Claim 1, characterized in that the osmotic pressure adjusting agent has a solubility of 8 g / 100 g or more in 100 g of ion-exchanged water at 25°C.

3. The absorbent article according to Claim 2, characterized in that the osmotic pressure adjusting agent has a solubility in 100 g of ion-exchanged water at 25°C that is in the range of 10 g / 100 g or more and 72 g / 100 g or less.

4. The absorbent article according to any one of claims 1 to 3, characterized in that the osmotic pressure adjusting agent contains an uncharged component.

5. The absorbent article according to any one of claims 1 to 4, characterized in that the osmotic pressure adjusting agent contains glycine.

6. The absorbent article according to any one of claims 1 to 5, characterized in that it contains 0.30 Osm / L or more of the osmotic pressure adjusting agent.

7. The absorbent article according to any one of claims 1 to 6, characterized in that the blood retention rate of the superabsorbent polymer is 12 g / g or more.

8. The absorbent article according to any one of claims 1 to 7, characterized in that the osmotic pressure adjusting agent is located on or on the skin-facing side of the absorbent.

9. The absorbent article according to claim 8, characterized in that the osmotic pressure adjusting agent is disposed in the absorbent body.

10. The absorbent body comprises an absorbent core containing the superabsorbent polymer and a core wrap sheet located on the skin-facing side of the absorbent core, The absorbent article according to claim 9, characterized in that the osmotic pressure adjusting agent is arranged in the core wrap sheet.

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