JP6887878B2 - Absorbent article - Google Patents

Description

The present invention relates to an absorbable article for menstrual blood absorption.

There are known techniques for applying a fluid treatment agent that acts on blood to an absorbent article to improve various performances of the absorbent article (for example, Patent Documents 1 to 3). Patent Document 1 discloses a menstrual zone including an absorbent pad containing a salt of a polyvalent ion. Patent Document 2 discloses a napkin containing a partially hydrated dicarboxylic acid anhydride copolymer or a polycation as a blood gelling agent. Patent Document 3 proposes a personal care absorbent article containing a triblock polymer containing polypropylene oxide and polyethylene oxide or a polycation as a fluid treatment material.

In addition, the applicant has previously proposed an absorbent article containing a blood coagulant containing a water-soluble metal compound in an absorbent core (see Patent Document 4).

Special Publication No. 38-17449 Japanese Unexamined Patent Publication No. 57-153648 Special Table 2002-528232 Japanese Unexamined Patent Publication No. 2005-287997

Patent Documents 1 and 4 do not disclose the state of application of the fluid treatment agent in the absorbent article except that the water-soluble metal compound is used as the blood coagulant, and the blood absorption rate is improved or the absorption amount is improved. There is no description about the configuration to be made. On the other hand, in the absorbable articles described in Patent Document 2 and Patent Document 3, the erythrocyte component can be aggregated, but the menstrual blood continuously discharged is absorbed by the agglomerates formed in the early stage. Although it is stated that a fluid treatment agent containing a polycation can be used, only data on a nonionic treatment material is actually disclosed. Further, in Patent Document 3, erythrocyte clots are trapped between fibers of non-woven web, but in these techniques, blood absorption is hindered due to a decrease in fluid permeability due to blood agglutination in the excretory portion, and blood is spilled. Ri time to absorb Kaka continuously it is difficult to guarantee the absorption of blood by the mechanism, the blood at the time of use is returned to the skin side, it was achieved also disadvantageous in terms of so-called liquid return. However, when considering further thinning of the absorbent article from the viewpoint of improving the wearing feeling, it is desired that the effect of improving the absorption performance by the blood cell flocculant is more effectively exhibited.
Therefore, an object of the present invention is to provide an absorbable article in which the effect of improving the absorption performance of the blood cell flocculant is more effectively exhibited.

The present invention includes a liquid-permeable front sheet arranged on the skin-facing surface side, a liquid-impermeable back sheet arranged on the non-skin-facing surface side, and an absorber arranged between both sheets. An absorbent article for blood absorption, wherein the absorber has an absorbent core containing pulp fibers and a core wrap sheet having pores and covering the absorbent core, and the absorbent core. A water-soluble blood cell flocculant is held in a state in which the pores of the core wrap sheet are filled in the core wrap sheet that covers the skin-facing surface side of the core wrap sheet, and water permeates the core wrap sheet. At the time, the absorbent article is provided in which the blood cell flocculant is dissolved to increase the voids in the pores.

The present invention also includes a liquid-permeable front sheet arranged on the skin-facing surface side, a liquid-impermeable back sheet arranged on the non-skin-facing surface side, and an absorber arranged between both sheets. An absorbent article for absorbing menstrual blood, wherein the absorber has an absorbent core containing pulp fibers and a core wrap sheet having pores and covering the absorbent core, and the absorbent core. A water-soluble cationic polymer is held in a state in which the pores of the core wrap sheet are filled in the core wrap sheet that covers the skin-facing surface side of the sex core, and the core wrap sheet is moistened with water. It provides an absorbent article in which the cationic polymer is dissolved upon permeation to increase the voids in the pores.

According to the absorbable article of the present invention, the effect of improving the absorption performance by the hemagglutination action of the blood cell flocculant or the cationic polymer is effectively exhibited, and excellent absorption performance is exhibited.

FIG. 1 is a plan view of a sanitary napkin according to an embodiment of the absorbent article of the present invention. FIG. 2 is a cross section taken along line II-II of FIG. FIG. 3 (a) is an electron microscope (SEM) photograph of a core wrap sheet in which a hemagglutin agent is held in a state of filling the pores, and FIG. 3 (b) shows blood cells on the core wrap sheet. It is an electron microscope (SEM) photograph which shows the state before holding a flocculant. FIG. 4 is an enlarged cross-sectional view of the absorber showing a preferable configuration of the absorber of the absorbent article of the present invention. FIG. 5 is an enlarged cross-sectional view of an absorber showing another preferred configuration of the absorber of the absorbent article of the present invention. FIG. 6 is an enlarged cross-sectional view of an absorber showing still another preferred configuration of the absorber of the absorbent article of the present invention. FIG. 7A is an electron microscope (SEM) photograph of the core wrap sheet used in Examples 1 and 2 before the hemagglutination agent was applied, and FIG. 7B is an electron microscope (SEM) photograph of the core wrap sheet used in Examples 1 and 2. FIG. It is an electron microscope (SEM) photograph of the core wrap sheet used in Examples 1 and 2 after the work, and FIG. 7 (c) shows that the hemagglutination agent is held in a state of filling the pores. It is an electron microscope (SEM) photograph after water permeating through the core wrap sheet used in Examples 1 and 2 (after the first water permeation).

Hereinafter, the absorbent article for menstrual blood absorption of the present invention will be described with reference to the drawings based on the sanitary napkin 1 (hereinafter, also referred to as “napkin 1”) which is a preferred embodiment thereof. Absorbent articles for menstrual blood absorption are included in sanitary napkins.
As shown in FIGS. 1 and 2, the napkin 1 includes a liquid-permeable front sheet 2 arranged on the skin-facing surface side, a liquid-impermeable back sheet 3 arranged on the non-skin-facing surface side, and both of them. It includes a liquid-retaining absorber 4 arranged between the sheets 2 and 3. The front surface sheet 2, the absorber 4, and the back surface sheet 3 are integrated to form the absorbent main body 5. Side leakage-proof sheets 6 are arranged on the surface sheet 2 sides of both sides of the absorbent body 5 in the longitudinal direction. The side leakage-proof sheet 6 has a free end 61 not joined to the surface sheet 2 and a fixed end 62 joined to the surface sheet 2, and is between the fixed end 62 and the free end 61 at the time of use. Is separated from the surface sheet 2 to form a leak-proof pocket (not shown) that prevents lateral leakage. A main body adhesive portion (not shown) used for fixing the shorts to the crotch portion is provided on the non-skin facing surface of the absorbent main body 5. Further, the napkin 1 has a pair of wing portions 7 on both side portions in the vertical direction X corresponding to the front-rear direction of the wearer. On the surface of the pair of wing portions 7 on the back surface sheet 3 side, a wing portion adhesive portion (not shown) used for fixing the crotch portion of the shorts to the non-skin facing surface is provided. Further, although not shown, heat-sealing portions may be provided on the entire peripheral edge of an absorbent article such as a napkin 1.

As shown in FIG. 1, the napkin 1 has an excretion portion facing portion B that is arranged to face the wearer's excretion portion (vaginal opening or the like) at the time of wearing, and a ventral side (anterior side) of the wearer with respect to the excretion portion facing portion B. ) It has a front portion A arranged closer to the wearer and a rear portion C arranged closer to the back side (rear side) of the wearer than the excretion portion facing portion B. The napkin 1 has a vertical direction X corresponding to the front-back direction of the wearer and a horizontal direction Y orthogonal to the vertical direction X. That is, the napkin 1 is divided into the front portion A, the excretion portion facing portion B, and the rear portion C in this order in the vertical direction X.

Further, in the present specification, the skin-facing surface is a surface of the napkin 1 or its constituent members (for example, the surface sheet 2 and the absorbent core 41) that is directed toward the wearer's skin side when the napkin 1 is worn, and is non-skin. The facing surface is a surface of the napkin 1 or its constituent members that faces the side opposite to the skin side (usually the clothing side) when the napkin 1 is worn.

In the absorbent article (sanitary product) of the present invention, when the excretory portion facing portion B has a so-called wing portion as in the napkin 1 of the present embodiment, the absorbent article has a so-called wing portion in the vertical direction X of the absorbent article. It is a region having a pair of wing portions on both the left and right sides, and more specifically, means a region sandwiched between the root of one wing portion along the vertical direction X and the root of the other wing portion along the vertical direction X. .. Further, when the absorbent article does not have a wing portion, two folding curves that cross the absorbent article in the lateral direction Y, which are generated when the absorbent article is folded into a tri-fold individual packaging form. With respect to (not shown), it means a region surrounded by the first folding curve and the second folding curve counting from the front end of the absorbent article in the vertical direction X.

In the napkin 1, the front surface sheet 2 covers the entire skin-facing surface of the absorber 4, and the back surface sheet 3 covers the entire non-skin-facing surface of the absorber 4. In the front surface sheet 2 and the back surface sheet 3, the extending portions of the absorber 4 from both end edges in the vertical direction X are joined to each other. Further, in the back surface sheet 3 and the side leakage-proof sheet 6, portions extending outward in the horizontal direction Y from both side edges of the absorber 4 along the vertical direction X are joined to each other. In this way, the absorber 4 is sandwiched between the front surface sheet 2 and the back surface sheet 3. Any joining means such as an adhesive, a heat seal, and an ultrasonic seal is used for joining the sheets constituting the napkin 1.

As shown in FIGS. 1 and 2, the napkin 1 includes a linear leak-proof groove 8 in which the front surface sheet 2 and the absorber 4 are integrally recessed toward the back surface sheet 3 side. Therefore, in the leak-proof groove 8, the density of each fiber that is a constituent member of the surface sheet 2 and the absorber 4 is higher than the density of the peripheral portion of the leak-proof groove 8. The term "linear" in the linear leak-proof groove 8 means that the shape of the leak-proof groove 8 which is a recessed portion is not limited to a straight line in a plan view but includes a curved line. Each line may be a continuous line or a discontinuous line such as a broken line. For example, the leak-proof groove 8 may be composed of a row formed by a large number of discontinuous point embosses.

The absorber 4 of the napkin 1 has an absorbent core 41 containing pulp fibers and a core wrap sheet 42 covering the absorbent core 41.
The core wrap sheet 42 in the present embodiment is formed on the skin side portion 42a (hereinafter, also referred to as the skin side core wrap sheet) that covers the skin facing surface side of the absorbent core 41 and the non-skin facing surface side of the absorbent core 41. It has a non-skin side portion 42b (also referred to as a non-skin side core wrap sheet) that is rolled down and covers the non-skin facing surface side of the absorbent core 41. Further, the core wrap sheet 42 has an overlapping portion 42c between the sheets on the non-skin side portion 42b.
In the core wrap sheet of the present invention, one sheet may wrap the entire absorbent core, or two or more sheets may wrap the entire absorbent core. For example, the skin-facing surface side and the non-skin-facing surface side of the absorbent core 41 may be covered with separate sheets.

The core wrap sheet 42 of the present embodiment contains a water-soluble blood cell flocculant. More specifically, in the core wrap sheet 42 of the present embodiment, the skin side core wrap sheet 42a is a blood cell flocculant arranging portion containing a blood cell flocculant. Further, in the core wrap sheet 42 of the present embodiment, in addition to using the skin-side core wrap sheet 42a as a hemagglutin-containing agent-arranging portion, the non-skin-side core wrap sheet 42b is used as a hemagglutin agent. The hemagglutin-arranging portion may be contained, and further, the hemagglutin-arranging portion may be formed so as to extend over the skin-side core wrap sheet 42a, the absorbent core 41, and the non-skin-side core wrap sheet 42b. In the absorbent article of the present invention, the skin-side core wrap sheet 42a may have a blood cell-aggregating agent-arranging portion containing a blood cell-aggregating agent, and the non-skin-side core wrap sheet 42b may have a blood cell-aggregating agent. The placement portion does not have to exist.
Conventionally, the core wrap sheet has been used for the purpose of improving the shape retention of the absorbent core, which is insufficient in shape retention by itself, and preventing the leakage of the constituent materials of the absorbent core. Fiber sheets such as non-woven fabrics are used.
The core wrap sheet 42 of the present embodiment has pores between the fibers in the skin facing surface, the non-skin facing surface, and the region in the thickness direction located between them in a state where the blood cell flocculant is not arranged. It has a structure in which the pores are communicated in the thickness direction. In other words, the open pores that communicate with each other form a network structure of interfiber voids in which the voids between the fibers are three-dimensionally and intricately connected.
The absorbent article in the present invention comprises a core wrap sheet 42 in which such pores are held in a state of being filled with a water-soluble blood cell flocculant.

In the napkin 1 of the present embodiment, the blood cell flocculant fills the pores on the skin-facing surface side of the skin-side core wrap sheet 42a. Further, as the core wrap sheet 42, the blood cell flocculant is kept in a state where the pores on the non-skin facing surface side 422 (the side in contact with the absorbent core 41) of the skin side core wrap sheet 42a are filled. May be used, or the skin-side core wrap sheet 42a may be used in which the pores of the skin-facing surface side 421 and the non-skin-facing surface side 422 in contact with the absorbent core 41 are kept filled. Further, it is more preferable to use a water-soluble blood cell flocculant in which the pores of the core wrap sheet 42 are held in a three-dimensionally filled state. The skin-facing surface side of the core wrap sheet 42 (skin-side core wrap sheet 42a) is divided into three parts in the thickness direction of the core wrap sheet 42 (skin-side core wrap sheet 42a). The layer closest to the skin is preferred. Further, when the core wrap sheet 42 (skin side core wrap sheet 42a) is divided into three parts in the thickness direction on the non-skin facing surface side, the core wrap sheet 42 (skin side core wrap sheet 42a) is divided into three parts when worn. It is preferably the layer farthest from the wearer's skin. Further, as another material having pores, a sheet such as an air-through non-woven fabric, a spunbonded non-woven fabric, or a urethane foam sheet can also be used as the core wrap sheet 42.

FIG. 3 (a) is an electron microscope (SEM) photograph of the core wrap sheet in which the blood cell flocculant is held in a state of filling the pores of the core wrap sheet 42, and FIG. 3 (b) is the core thereof. It is an electron microscope (SEM) photograph which shows the state before holding a hemagglutination agent on a wrap sheet 42.
As can be seen from the comparison between FIGS. 3A and 3B, when the core wrap sheet 42 is a fiber sheet, the blood cell flocculant is held in a state of filling the pores of the core wrap sheet 42. Is a state in which the interfiber voids are narrowed by attaching the blood cell flocculant by the method described later, and all the pores of the core wrap sheet 42 are filled with the blood cell flocculant. I don't need it. In the plane direction, the ratio (occlusion rate) of the area filled with the blood cell flocculant at least when the total area of the pores is 100% in the pores on the blood cell flocculant placement surface is that of menstrual blood or the like. Considering the balance between the rate at which water passes through the core wrap sheet and the solubility of the blood cell flocculant, it is preferable to appropriately determine the optimum occlusion rate according to the type of the core wrap sheet and the blood cell flocculant. That is, the blockage rate of the core wrap sheet 42 due to the blood cell flocculant is 10% or more from the viewpoint of sufficiently dissolving the blood cell flocculant when water such as menstrual blood passes through the core wrap sheet. Preferably, 15% or more is more preferable. Further, from the viewpoint of efficiently dissolving the blood cell flocculant, the obstruction rate is preferably 100% or less, more preferably 95% or less.

In addition, the ratio of the volume filled with the hemagglutination agent (volume blockage rate) in the pores forming the three-dimensionally connected network structure in the thickness direction is such that water such as menstrual blood is the core wrap sheet. In consideration of the balance between the permeation rate and the solubility of the hemagglutination agent, it is preferable to appropriately determine the optimum volume occlusion rate according to the type of core wrap sheet or hemagglutination agent. That is, the occlusion rate of the core wrap sheet 42 by the blood cell flocculant is from the viewpoint of sufficiently dissolving the blood cell flocculant when menstrual blood passes through the core wrap sheet when the volume of the entire pore portion is 100%. The volume blockage rate is preferably 10% or more, more preferably 15% or more. Further, from the viewpoint of efficiently dissolving the blood cell flocculant, the obstruction rate is preferably 90% or less, more preferably 70% or less. In this case, when the core wrap sheet 42 is cut to observe the cross section and the cut surface is observed by SEM, both the area occupied by the pores and the area of the buried hemagglutin are analyzed by means such as image analysis. The volume occlusion rate of the pores can be measured by quantifying with.

From the viewpoint of more reliably and effectively dissolving a large amount of blood cell flocculant to develop aggregation and separation, the blood cell flocculant is a fiber and a fiber in the pores of the skin facing surface side 421 of the skin side core wrap sheet 42a. It is preferable to fill the pores so as to stretch a film between them. The fact that the core wrap sheet 42 is filled with a film means that the blood cell flocculant is present across the plurality of fibers facing the pores. To do.
Furthermore, from the viewpoint of efficiently causing the dissolution of the blood cell flocculant by contact with water such as menstrual blood, the pores of the core wrap sheet 42 are three-dimensionally communicated in the thickness direction by the blood cell flocculant. It is more preferable that there are pores that are filled in the absence. When menstrual blood permeates the core wrap sheet 42 from the skin-facing surface side to the non-skin-facing surface side in the thickness direction of the fiber sheet in a state where the hemagglutination agent does not communicate three-dimensionally in the thickness direction. , It is preferable in that it always involves dissolution of the hemagglutination agent.

As described above, the core wrap sheet 42 in the present invention has pores between the fibers, and the pores have a structure in which the pores are communicated with each other in the thickness direction. A fiber sheet is used which forms a network structure of interfiber voids in which the voids between the fibers are three-dimensionally and complicatedly connected depending on the portion. It is also possible to use a resin film having communication pores that communicate in the thickness direction. In addition, in this specification, a "core wrap sheet" refers to a sheet in a state before containing a blood cell flocculant. The core wrap sheet 42 is preferably a sheet made of cellulosic fibers, because the blood cell flocculant efficiently fills the pores.
The core wrap sheet 42 of the present embodiment is preferably a sheet composed of cellulosic fibers, and has a basis weight of preferably 10 g / m from the viewpoint of liquid permeability, hardness, and pore size. ^{It is 2} or more, more preferably 13 g / m ² or more, preferably 30 g / m ² or less, still more preferably 20 g / m ² or less. The core wrap sheet 42 of the present embodiment is mainly manufactured by a wet papermaking method, but may be manufactured by a dry method such as airlaid.

Examples of the cellulosic fibers constituting the core wrap sheet 42 of the present embodiment include wood pulp fibers, rayon fibers, cotton fibers, and cellulose acetate fibers. Examples of the raw material pulp of the cellulose-based fiber include wood pulp such as coniferous kraft pulp or broadleaf kraft pulp, and non-wood pulp such as cotton pulp or straw pulp. These cellulosic fibers may be used alone or in combination of two or more. Further, from the viewpoint of improving the strength, a small amount of non-cellulosic fiber can be mixed. Examples of non-cellulosic fibers include polyolefin fibers such as polyethylene and polypropylene, and condensed fibers such as polyester and polyamide. The proportion of the cellulosic fibers in the constituent fibers of the thin paper is preferably 70% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and further preferably 100% by mass.

Further, a non-woven fabric can be used as the core wrap sheet 42. As a type of non-woven fabric, there are pores between the fibers, and the pores have a structure in which they are communicated in the thickness direction, and the gaps between the fibers are three-dimensional due to the communicated pores. Non-woven fabrics produced by various manufacturing methods can be used as long as they form a network structure of interfiber gaps that are intricately connected to each other. For example, spunbonded non-woven fabrics, melt-blown non-woven fabrics, and high-speed water flow treatments are used to entangle the constituent fibers of the fiber web. A spunlace non-woven fabric, which is a non-woven fabric obtained by heat-sealing, an air-through non-woven fabric, which is a non-woven fabric obtained by heat-sealing the constituent fibers of a fiber web by hot air treatment, and a non-woven fabric obtained by adhering the constituent fibers of a fiber web with an adhesive. A certain resin-bonded non-woven fabric and the like can be mentioned. The fiber web of spunlace non-woven fabric, air-through non-woven fabric, and resin-bonded non-woven fabric can be produced by a card machine, an air-laid method in which fibers are stacked in the air, or the like.

Raw material fibers for non-woven fabrics are made from cellulose-based hydrophilic fibers such as wood pulp fibers, rayon fibers, cotton fibers, and cellulose acetate, and synthetic resins such as polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, and polyamides such as nylon. Synthetic fibers can be mentioned. As the synthetic fiber, a core-sheath type or side-by-side type composite fiber can also be used. Among these, for the same reason as using thin paper, it is preferable that the raw material fiber is a cellulosic fiber also in the case of the non-woven fabric of various manufacturing methods. The proportion of cellulosic fibers in the constituent fibers of the non-woven fabric is preferably 70% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and further preferably 100% by mass. As the raw material fiber of the non-woven fabric, one kind may be used alone or two or more kinds may be used in combination.

As the "resin film having communication pores communicating in the thickness direction" used as the core wrap sheet 42 of the present embodiment, for example, a resin film having through holes can be used. The diameter of the through hole is preferably 0.2 mm or more and 4.0 mm or less, and more preferably 0.5 mm or more and 2.5 mm or less. Further, the number of through holes is preferably about 10 to 50 per 1 cm square.

The method for retaining the blood cell flocculant in the core wrap sheet 42 of the present embodiment is not particularly limited as long as it can be retained so as to fill the pores, but it is dissolved in an appropriate solvent and various physical properties such as viscosity are appropriately adjusted. It is preferable to attach or immerse the core wrap sheet 42 as a prepared solution and then dry to remove the solvent from the viewpoint that the pores of the core wrap sheet 42 are easily maintained in a state where the blood cell flocculant is embedded.
The type of solvent is not particularly limited as long as it can dissolve the blood cell flocculant, and for example, water can be conveniently used. When the solution is applied to a sheet to produce a hemagglutination sheet, the solvent is highly volatile from the viewpoint of shortening the drying time of the solution and thereby unevenly distributing the hemagglutination on the coating surface side. It is preferable to use a solvent. From this point of view, the solvent is preferably an organic solvent capable of dissolving the blood cell flocculant. Examples of such organic solvents include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, acetone, tetrahydrofuran, acetonitrile, N, N-dimethylformamide, dimethyl sulfoxide, acetic acid and formic acid. These organic solvents may be used singly, or two or more of them combine seen. Alternatively, one or more of these organic solvents can be used in combination with water. It is preferable to use ethanol from the viewpoint of safety, high volatility, and economy.

A method of adhering a solution containing the blood cell aggregating agent in the core wrap sheet 42, immersion solution, spray coating method, a dipping method, a transfer method, a die coating, gravure coating, inkjet method, screen printing method, according to the printing Examples thereof include coating a predetermined portion of the absorber 4 with a liquid coating device using a known liquid coating apparatus such as screen printing, and these can be freely used. Of these, the spray coating method efficiently fills the vacancies by appropriately adjusting the shape of the spray nozzle, the amount of application, etc. of the solution containing the blood cell flocculant whose various physical properties such as viscosity have been appropriately adjusted. It is preferable because it can be kept in a state.
Further, the drying may be any of drying by heating, drying by reduced pressure, and drying by combining heating and reduced pressure, but natural drying may be used instead of forced drying. From the viewpoint of drying by heating and fixing the core wrap sheet 42 in a filled state, it is dried by heating it to a higher temperature and rapidly removing the solvent as long as the blood cell flocculant and the core wrap sheet are not damaged. It is more preferable to do so.

Further, from the viewpoint of fixing the core wrap sheet 42 in the napkin 1 of the present embodiment in a state where the pores are filled, the pH of the water extract measured by the JIS method (JIS P8331-1: 2013) is preferable. Is 3.5 or more, more preferably 6.0 or more, still preferably 9.0 or less, still more preferably 8.0 or less, and preferably 3.5 or more and 9.0 or less, still more preferably 6. It is 0.0 or more and 8.0 or less.

Further, in the core wrap sheet 42 of the napkin 1 of the present embodiment, when water permeates the core wrap sheet 42, the blood cell flocculant dissolves and the voids in the pores of the core wrap sheet 42 increase. There is. This is caused by the blood cell flocculant being held in a state of filling the pores, and when water passes through the pores, the blood cell flocculant dissolves and disappears from the pores. That is, when the blood cell flocculant completely fills the pores and closes the pores, the blood cell flocculant dissolves to generate voids from the state where there are no voids. Further, when some voids are present in a part of the pores that are filled with the blood cell flocculant, the volume of the voids is expanded by the dissolution of the blood cell flocculant.

In the napkin 1 of the present embodiment, the core wrap sheet 42 that covers the absorbent core 41 holds the blood cell flocculant when it is water-soluble, so that menstrual blood passes through the core wrap sheet 42 during use. Occasionally, the blood cell flocculant dissolves in the menstrual blood held in the pores, and the red blood cells aggregate by the action of the blood cell flocculant at the boundary between the core wrap sheet 42 and the absorbable core 41 and in the absorbable core 41. To do. As a result, menstrual blood is separated into erythrocyte aggregates and parts other than erythrocytes, and the movement of erythrocyte aggregates is suppressed as compared with the parts other than erythrocytes, whereas the parts other than erythrocytes are. , Diffuses well in the absorbent core. As a result, in the menstrual blood, the portion other than the red blood cells is preferentially absorbed by the absorber 4. In particular, when a highly absorbent polymer is used, absorption inhibition due to accumulation of red blood cells on the surface is prevented. As a result, menstrual blood is absorbed by the highly absorbent polymer in a state in which the parts other than the red blood cells are more reliably separated from the aggregates of the red blood cells, and thus the red blood cells are deposited on the surface of the highly absorbent polymer. Absorption inhibition is less likely to occur.
In the napkin of the present embodiment, due to such an action, the potential absorption performance of the absorbent core is sufficiently expressed, and the napkin has excellent absorption performance.

From the viewpoint of ensuring that the above-mentioned effects are more reliably achieved, the core wrap sheet 42 has a larger amount of the blood cell flocculant on the side facing the skin than in a state where the blood cell flocculant is uniformly present in the entire layer. This state is preferable from the viewpoint of more effectively filling the pores. "A large amount is present on the skin facing surface side" means that the blood cell flocculant is present more on the skin facing surface side than on the non-skin facing surface side, and the blood cell flocculant is present on the skin facing surface side. Includes aspects that do not exist on the non-skin facing surface side.

When the blood cell flocculant fills the pores on the skin facing surface side of the pores of the skin side core wrap sheet 42a, the blood cell flocculant dissolves by contact with the water of menstrual blood and is not. It flows out to the side facing the skin. Moreover, since menstrual blood is less likely to enter the inside of the core wrap from the pores, the menstrual blood spreads on the surface facing the skin, and the contact efficiency between the water in the menstrual blood and the blood cell flocculant is increased. From this state, the blood cell aggregating agent is dissolved in water and a strong force is exerted to move the skin-side core wrap sheet 42a from the skin-facing surface to the non-skin-facing surface side. Some are captured in the core wrap sheet and some are captured in the absorbent core. Therefore, the network of interfiber voids is partially blocked, but the interfiber voids are expanded in other portions, so that the inhibition of liquid permeability in the repeated absorption of menstrual blood is unlikely to occur. Further, since the core wrap sheet has a three-dimensional network structure of interfiber voids, the water content of menstrual blood in which the hemagglutination agent is dissolved diffuses not only in the thickness direction but also in the plane direction. In the core wrap, the portion where the void portion is closed by the agglutinin and the void portion where the blood cell flocculant is retained coexist. Therefore, the menstrual blood that reaches the core wrap after a certain period of time has passed from the initial absorption of menstrual blood enters the core wrap through the increased pores on the side facing the skin, and enters the core wrap through the voids of the three-dimensional network structure. You can move inside. Then, the blood cell flocculant held in the void portion comes into contact with the menstrual blood, and while the menstrual blood and the blood cell flocculant move in the thickness direction and the surface direction, the aggregate and the blood cell flocculant are mainly composed of water. The liquid component to be produced is produced. By repeating such a phenomenon, it is possible to realize a napkin capable of absorbing menstrual blood for a long period of time. When the leak-proof groove 8 is provided as in the napkin 1 of the present embodiment, if the leak-proof groove 8 and the blood cell flocculant placement portion are arranged so as to overlap each other in a plan view, the water content in menstrual blood. Is more likely to concentrate in the leak-proof groove 8, and the above-mentioned effect is further enhanced.

On the other hand, the present invention also includes a case where the blood cell flocculant fills the pores on the non-skin facing surface side among the pores of the core wrap sheet 42. In this case as well, a sanitary absorbable article capable of effectively absorbing menstrual blood can be obtained by a mechanism similar to the above-mentioned form in which the blood cell flocculant fills the pores on the skin-facing surface side of the core wrap. .. However, in order to obtain the advantageous effect of stably absorbing menstrual blood for a long period of time from the initial stage of excretion, it is preferable that the blood cell flocculant fills the pores on the skin-facing surface side of the core wrap. Further, it is preferable that at least 10% or more of the area of the pores in the entire surface area on the side facing the skin is filled with the blood cell flocculant in order to further ensure this effect. In addition, this mechanism does not necessarily have to have a blood cell flocculant-arranging portion containing a blood cell flocculant in the excretion portion facing portion B, and is physiologically absorbable so that menstrual blood can be effectively absorbed by the above-mentioned mechanism. Goods can be obtained.

In order for the blood cell flocculant to preferentially fill the pores on one side of the core wrap sheet, it is preferable that the blood cell flocculant is contained and the viscosity when added to the core wrap sheet at the time of application or the like is preferable. It is convenient to adopt a method of adding a solution of 1 mPa · s or more to at least one surface of the core wrap sheet. In this case, the solution can be added only to one side of the core wrap sheet. However, according to this method, it is also possible to apply the solution on both sides so that the amount of the solution added is smaller on the other side than on one side, which is preferable. In particular, by adding a highly viscous solution having a viscosity equal to or higher than the above value only to one side of the core wrap sheet, that is, the surface facing the skin, the solution uniformly permeates the entire thickness direction of the core wrap sheet. This is suppressed, and a relatively large amount of the solution remains on the added surface side. In that state, the drying of the solution proceeds, and as a result, a relatively large amount of the blood cell flocculant is present on the added surface side. From this point of view, the viscosity of the solution is more preferably 1 mPa · s or more at the time of application, and further preferably 3 mPa · s or more. From the viewpoint of coatability of the solution, the upper limit of the viscosity is preferably 1000 mPa · s or less, and more preferably 100 mPa · s or less.

The viscosity of the solution containing the blood cell flocculant is measured by the following method. Using the B-type viscometer TVB-10 manufactured by Toki Sangyo Co., Ltd., the rotor No. The measurement can be performed under the measurement conditions of 19, 30 rpm, 25 ° C., and 60 seconds.

Further, from the viewpoint of obtaining the effect that menstrual blood can be stably absorbed for a long time from the initial stage of excretion by repeating contact and dissolution of the blood cell flocculant held in the void portion and menstrual blood, the core wrap sheet 42 is used. , It is preferable that the second water permeation speed is faster than the first water permeation speed.
The first water permeation rate and the second water permeation rate are measured as follows.
[Measurement method of first water permeability and second water permeation rate]
The first water permeation rate and the second water permeation rate were measured as shown in the figure. First, a sample piece was prepared by cutting the liquid passage layer into a length of 50 mm and a width of 50 mm, and then this sample piece was sandwiched and fixed from both upper and lower sides with a glass tube having an inner diameter of 35 mm. At this time, fix it from both sides with a clip via a silicone rubber so that the liquid does not seep out from the side during the measurement. Take 3 g of physiological saline as a measurement solution in a 10 ml beaker and gently inject it into the glass tube. After injecting physiological saline, the time required for the amount of water permeation (the amount of liquid that permeated the sample piece) to reach 2.3 g was measured, and this was taken as the initial liquid passage time (unit: seconds), and the amount of water permeation 2. The initial water permeation rate (unit: g / sec) was obtained by dividing 3 g by the initial liquid passage time. After allowing it to stand for 3 minutes as it is, gently inject the above-mentioned 3 g of the measurement solution, obtain the second liquid passage time (unit: seconds) in the same manner, and divide 2.3 g by the second liquid passage time. The second water permeation rate (unit: g / sec) was used. The above was measured on an electronic balance.

From the viewpoint of ensuring that the effect of the present invention is more reliably achieved, the first water permeation rate and the second water permeation rate measured by the above method are the ratio of the second water permeation rate to the first water permeation rate (second water permeation rate / The first water permeation rate) is preferably 1.05 times or more, more preferably 1.5 times or more, preferably 150 times or less, further preferably 30 times or less, and preferably 1.05 times or more. It is 150 times or less, more preferably 1.5 times or more and 30 times or less.
The initial water permeation rate is preferably 0.01 g / sec or more, more preferably 0.05 g / sec or more, preferably 1.50 g / sec or less, still more preferably 0.70 g / sec or less. Further, it is preferably 0.01 g / sec or more and 1.50 g / sec or less, and more preferably 0.05 g / sec or more and 0.70 g / sec or less. The second water permeation rate is preferably 0.25 g / sec or more, more preferably 0.75 g / sec or more, and preferably 2.0 g / sec or less, still more preferably 1.5 g / sec or less. Further, it is preferably 0.25 g / sec or more and 2.0 g / sec or less, and more preferably 0.5 g / sec or more and 1.5 g / sec or less.

In order for the core wrap sheet 42 to have a second water permeation rate higher than the first water permeation rate, it must have the physical properties to start dissolution within at least 3 minutes from the time when the blood cell flocculant comes into contact with the liquid to be measured. However, it is preferable that the dissolution rate is high. In addition, the skin-side core wrap sheet 42a preferably has more blood cell flocculants on the skin-facing surface side 421 than on the non-skin-facing surface side 422. In particular, it is preferable that the blood cell flocculant is present only on the skin-facing surface side 421 of the skin-side core wrap sheet 42a. By doing so, the above-mentioned mechanism functions more effectively, the agglutinated portion is transferred to the non-skin facing surface side of the skin side core wrap sheet 42a, and the skin side core wrap sheet 42a faces the skin. The increased interfiber voids formed on the surface side promote the uptake of menstrual blood, and the plasma component separated by the hemagglutin inside the skin side core wrap sheet 42a becomes easier to reach the absorbable core 41. There is.

The absorbent core 41 of the napkin 1 of the present embodiment is made of a mixed product of pulp fibers and a highly absorbent polymer. The mixed fiber stack is manufactured by a known drum-type triple product device equipped with a triple product drum having a recess for accumulation on the peripheral surface, and is sucked from the bottom surface of the recess for accumulation while being sucked from the circumference of the triple product drum. Pulp fibers and highly absorbent polymers as materials for forming the absorbent core are supplied to the surface in a scattered state, and the material for forming the absorbent core is deposited in the recesses for accumulation and then separated from the recesses for accumulation. Can be obtained. The absorbent core 41 of the napkin 1 of the present embodiment may be a single fiber stack of pulp fibers that does not contain a highly absorbent polymer.

Examples of the pulp fiber constituting the absorbent core 41 include cellulosic hydrophilic fibers such as wood pulp fiber, rayon fiber, cotton fiber and cellulose acetate. These fibers may be used alone or in combination of two or more. Examples of the raw material pulp of the pulp fiber include wood pulp such as coniferous kraft pulp or broadleaf kraft pulp, and non-wood pulp such as cotton pulp or walla pulp. From the viewpoint of improving strength, the absorbent core 41 includes not only pulp fibers made of cellulose-based hydrophilic fibers, but also polyolefin-based fibers such as polyethylene and polypropylene, and synthetic fibers such as condensed fibers such as polyester and polyamide. You may mix a small amount. In the absorbent core in the present invention, the proportion of pulp fibers (cellulosic fibers), particularly wood pulp fibers, is preferably 70% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and further. It is preferably 100% by mass.

Further, the absorbent core 41 may contain a water-absorbing polymer. As the highly absorbent polymer, a particulate polymer is generally used, but a fibrous polymer may also be used. When a highly absorbent polymer in the form of particles is used, the shape may be spherical, lumpy, bale-shaped or amorphous. As the highly absorbent polymer, a polymer or copolymer of acrylic acid or an alkali metal salt of acrylic acid can generally be used. Examples thereof include polyacrylic acid and salts thereof, and polymethacrylic acid and salts thereof. As the polyacrylate or polymethacrylate, a sodium salt can be preferably used. In addition, acrylic acid or methacrylic acid, maleic acid, itaconic acid, acrylamide, 2-acrylamide-2-methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2-hydroxyethyl (meth) acrylate, styrenesulfonic acid, etc. A copolymer obtained by copolymerizing the comonomer of the above in a range that does not deteriorate the performance of the highly absorbent polymer can also be used. By containing the water-absorbent polymer, it is possible to more stably quickly absorb and retain a large amount of excrement such as blood.
In addition, a deodorant, an antibacterial agent, or the like may be added to the absorbent core 41 as needed.

The blood cell flocculant provided in the napkin 1 acts to aggregate red blood cells in the blood to form agglomerates and separate them from plasma components. As a preferable hemagglutinant, when 1000 ppm is added to simulated blood, at least two or more erythrocytes aggregate to form an agglutinin while maintaining the fluidity of the blood. Here, in the "state in which the fluidity of blood is maintained", 10 g of blood to which 1000 ppm of the measurement sample is added is added to a screw tube bottle (Maruem product number "Screw tube No. 4", mouth inner diameter 14.5 mm, body diameter). It means a state in which 80% or more of the menstrual blood pseudo-blood flows down within 5 seconds when the screw tube bottle containing the pseudo-blood is placed in 27 mm and 55 mm in total length and inverted 180 degrees. The pseudo blood has a viscosity of 8 mPa · s measured using a B-type viscometer (model number TVB-10M manufactured by Toki Sangyo Co., Ltd., measurement conditions: rotor No. 19, 30 rpm, 25 ° C., 60 seconds). The blood cell / plasma ratio of defibered horse blood (manufactured by Japan Biotest Research Institute Co., Ltd.) was prepared. Further, whether or not "two or more erythrocytes aggregate to form an agglutinin" is determined as follows. That is, the measurement sample is a 1000ppm the added the pseudo blood was diluted 4000-fold with physiological saline, a laser diffraction / scattering particle size distribution analyzer (HORIBA Ltd. model number: LA-950V2, Measurement conditions: flow type The average median diameter of the volume particle size measured at a temperature of 25 ° C. by the laser diffraction / scattering method using cell measurement (cell measurement, circulation speed 1, no ultrasonic waves) corresponds to the size of an agglutinating agglutination of two or more red blood cells. When it is 10 μm or more, it is determined that “two or more erythrocytes aggregate to form an agglutinating mass”.

The blood cell flocculant to be retained on the core wrap sheet 42 preferably contains a cationic polymer. Examples of the cationic polymer include cationized cellulose and cationized starch such as hydroxypropyltrimonium chloride starch. The blood cell flocculant may also contain, as a cationic polymer, a quaternary ammonium salt homopolymer, a quaternary ammonium salt copolymer, or a quaternary ammonium salt polycondensate. The blood cell flocculant may also contain a low molecular weight natural homopolymer such as polylysine as the cationic polymer. In the present invention, the "quaternary ammonium salt" includes a compound having a positive monovalent charge at the position of the nitrogen atom or a compound having a positive monovalent charge at the position of the nitrogen atom by neutralization. Specific examples thereof include a salt of a quaternary ammonium cation, a neutralized salt of a tertiary amine, and a tertiary amine having a cation in an aqueous solution. The "quaternary ammonium moiety" described below is also used with the same meaning, and is a site that is positively charged in water. Further, in the present invention, the "copolymer" is a polymer obtained by copolymerizing two or more kinds of polymerizable monomers, and is a binary copolymer and a ternary or more copolymer. Includes both things. In the present invention, the "polycondensate" is a polycondensate obtained by polymerizing a condensate composed of two or more kinds of monomers. When the blood cell flocculant contains, as the cationic polymer, a quaternary ammonium salt homopolymer and / or a quaternary ammonium salt copolymer and / or a quaternary ammonium salt polycondensate, the blood cell flocculant is the first. It may contain any one of a quaternary ammonium salt homopolymer, a quaternary ammonium salt copolymer and a quaternary ammonium salt polycondensate, or any combination of two or more. May be good. Further, the quaternary ammonium salt homopolymer may be used alone or in combination of two or more. Similarly, the quaternary ammonium salt copolymer may be used alone or in combination of two or more. Similarly, as the quaternary ammonium salt polycondensate, one type may be used alone or two or more types may be used in combination. As described above, the term "hemagglutinant" as used herein refers to a single compound capable of agglutinating blood erythrocytes or a combination of a single compound thereof, or a combination of a plurality of compounds to cause erythrocyte aggregation. It is an agent that expresses. That is, the blood cell agglutinating agent is an agent limited to those having a hemagglutination effect. Therefore, when the blood cell flocculant contains a third component, it is expressed as a blood cell flocculant composition to distinguish it from the blood cell flocculant. The term "single compound" as used herein is a concept that includes compounds having the same composition formula but different molecular weights due to different numbers of repeating units.

Among the various cationic polymers described above, the use of a quaternary ammonium salt homopolymer, a quaternary ammonium salt copolymer, or a quaternary ammonium salt polycondensate is particularly effective in terms of adsorptivity to erythrocytes. preferable. In the following description, for convenience, the quaternary ammonium salt homopolymer, the quaternary ammonium salt copolymer, and the quaternary ammonium salt polycondensate are collectively referred to as "quaternary ammonium salt polymer".

The quaternary ammonium salt homopolymer is obtained by using one kind of polymerizable monomer having a quaternary ammonium moiety and polymerizing the monomer. On the other hand, the quaternary ammonium salt copolymer uses at least one polymerizable monomer having a quaternary ammonium moiety and, if necessary, at least one polymerizable monomer having no quaternary ammonium moiety. It was obtained by using seeds and copolymerizing them. That is, the quaternary ammonium salt copolymer is obtained by using two or more kinds of polymerizable monomers having a quaternary ammonium moiety and copolymerizing them, or a quaternary ammonium moiety is used. It is obtained by copolymerizing one or more polymerizable monomers having one or more and one or more polymerizable monomers having no quaternary ammonium moiety. The quaternary ammonium salt copolymer may be a random copolymer, an alternating copolymer, a block copolymer, or a graft copolymer. The quaternary ammonium salt polycondensate is obtained by polymerizing the condensate using one or more monomers having a quaternary ammonium moiety. That is, the quaternary ammonium salt polycondensate is obtained by using a condensate of two or more types of monomers having a quaternary ammonium moiety and polymerizing them, or the quaternary ammonium moiety. It is obtained by polycondensation of one or more monomers having a quaternary ammonium moiety and one or more monomers having no quaternary ammonium moiety.

The quaternary ammonium salt polymer is a cationic polymer having a quaternary ammonium moiety. The quaternary ammonium moiety can be generated by quaternary ammonium conversion of a tertiary amine with an alkylating agent. Alternatively, the tertiary amine can be dissolved in an acid or water and neutralized to produce it. Alternatively, it can be produced by quaternary ammonium conversion by a nucleophilic reaction including a condensation reaction. Examples of the alkylating agent include alkyl halides and dialkyl sulfates such as dimethyl sulfate and dimethyl sulfate. Of these alkylating agents, dialkyl sulfate is preferable because it does not cause the problem of corrosion that may occur when alkyl halide is used. Examples of the acid include hydrochloric acid, sulfuric acid, nitrate, acetic acid, citric acid, phosphoric acid, fluorosulfonic acid, boric acid, chromic acid, lactic acid, oxalic acid, tartaric acid, gluconic acid, formic acid, ascorbic acid, hyaluronic acid and the like. .. In particular, it is preferable to use a quaternary ammonium salt polymer in which the tertiary amine moiety is quaternary ammoniumized with an alkylating agent because the electric double layer of erythrocytes can be reliably neutralized. Quaternary ammonium conversion by a nucleophilic reaction including a condensation reaction can occur like a ring-opening polycondensation reaction of dimethylamine and epichlorohydrin, and a cyclization reaction of dicyandiamide and diethylenetriamine.

As a result of the study by the present inventor, it has been found that the use of a cationic polymer is particularly effective for producing agglomerates of erythrocytes during menstrual blood. The reason for this is as follows. Red blood cells have an erythrocyte membrane on their surface. The erythrocyte membrane has a two-layer structure. This two-layer structure consists of a lower erythrocyte membrane skeleton and an upper lipid membrane. The lipid film exposed on the surface of red blood cells contains a protein called glycophorin. Glycophorin has a sugar chain at the end of which an anion-charged sugar called sialic acid is bound. As a result, erythrocytes can be treated as anionic-charged colloidal particles. A flocculant is generally used for agglutination of colloidal particles. Considering that erythrocytes are anionic colloidal particles, it is advantageous to use a cationic substance as the flocculant from the viewpoint of neutralizing the electric double layer of erythrocytes. Further, when the flocculant has a polymer chain, the polymer chains of the flocculant adsorbed on the surface of the erythrocytes are likely to be entangled with each other, which promotes the aggregation of erythrocytes. Further, when the flocculant has a functional group, the interaction between the functional groups also promotes the aggregation of erythrocytes, which is preferable.

From the viewpoint of effectively producing agglomerates of erythrocytes, the cationic polymer preferably has a molecular weight of 2000 or more, and more preferably 10,000 or more. When the molecular weight of the cationic polymer is equal to or higher than these values, entanglement of the cationic polymers between erythrocytes and cross-linking of the cationic polymers between erythrocytes sufficiently occur. The upper limit of the molecular weight is preferably 30 million or less, and more preferably 22 million or less. When the molecular weight of the cationic polymer is less than or equal to these values, the cationic polymer dissolves well in menstrual blood. The molecular weight of the cationic polymer is preferably 20 or more and 30 million or less, and further preferably 10,000 or more and 22 million or less from the viewpoint of enhancing the effect of suppressing the movement of blood beyond the coagulant arrangement portion. preferable. Furthermore, when the molecular weight of the cationic polymer is 10,000 or more and 150,000 or less, particularly 10,000 or more and 120,000 or less, the agglomerates of menstrual blood do not become excessively enlarged and are generated to an appropriate size. It is suppressed that the agglomerates block the pulp fiber voids and the voids in the pores of the core wrap sheet contained in the core, and even after the cationic polymer is well dissolved in the menstrual blood, the warp in the absorbent core and the core wrap sheet. It is preferable because the blood permeability is maintained high. The molecular weight referred to in the present invention is a weight average molecular weight. Further, two or more kinds of cationic polymers having different molecular weights may be combined within the above-mentioned molecular weight range. The molecular weight of the cationic polymer can be controlled by appropriately selecting the polymerization conditions thereof. The molecular weight of the cationic polymer can be measured using HLC-8320GPC manufactured by Tosoh Corporation. The specific measurement conditions are as follows. As the column, a guard column α manufactured by Tosoh Corporation and an analysis column α-M connected in series are used at a column temperature of 40 ° C. The detector uses RI (refractive index). As a measurement sample, 1 mg of the treatment agent (quaternary ammonium salt polymer) to be measured is dissolved in 1 mL of the eluent. As the copolymer containing a water-soluble polymerizable monomer such as hydroxyethyl methacrylate, an eluent in which 150 mmol / L sodium sulfate and 1% by mass of acetic acid are dissolved in water is used. A copolymer containing a water-soluble polymerizable monomer such as hydroxyethyl methacrylate has a molecular weight of 5900 pullulan, a molecular weight of 47300 pullulan, a molecular weight of 212,000 pullulan, and a molecular weight of 788,000 per 10 mL of the eluent. Pullulan, a mixture of pullulan in which 2.5 mg each is dissolved, is used as a molecular weight standard. The copolymer containing a water-soluble polymerizable monomer such as hydroxyethyl methacrylate is measured at a flow rate of 1.0 mL / min and an injection amount of 100 μL. Except for copolymers containing water-soluble polymerizable monomers such as hydroxyethyl methacrylate, elution of 50 mmol / L lithium bromide and 1% by mass of acetic acid in ethanol: water = 3: 7 (volume ratio). Use liquid. Except for copolymers containing water-soluble polymerizable monomers such as hydroxyethyl methacrylate, polyethylene glycol (PEG) having a molecular weight of 106, PEG having a molecular weight of 400, PEG having a molecular weight of 1470, and PEG having a molecular weight of 6450 per 20 mL of eluent. , Polyethylene oxide (PEO) having a molecular weight of 50,000, PEO having a molecular weight of 235,000, PEO having a molecular weight of 875,000, and a mixture of PEG-PEO in which 10 mg each is dissolved are used as the molecular weight standard. Except for the copolymer containing a water-soluble polymerizable monomer such as hydroxyethyl methacrylate, the measurement is carried out at a flow rate of 0.6 mL / min and an injection amount of 100 μL.

When a quaternary ammonium salt polymer is used as the cationic polymer from the viewpoint of more effectively producing agglomerates of erythrocytes, the flow potential of the quaternary ammonium salt polymer is preferably 1500 μeq / L or more. , 2000 μeq / L or more, more preferably 3000 μeq / L or more, and even more preferably 4000 μeq / L or more. When the flow potential of the quaternary ammonium salt polymer is equal to or higher than these values, the electric double layer of erythrocytes can be sufficiently neutralized. The upper limit of the flow potential is preferably 13000 μeq / L or less, more preferably 8000 μeq / L or less, and even more preferably 6000 μeq / L or less. When the flow potential of the quaternary ammonium salt polymer is equal to or less than these values, it is possible to effectively prevent the electrical repulsion between the quaternary ammonium salt polymers adsorbed on the erythrocytes. The flow potential of the quaternary ammonium salt polymer is preferably 1500 μeq / L or more and 13000 μeq / L or less, more preferably 2000 μeq / L or more and 13000 μeq / L or less, and 3000 μeq / L or more and 8000 μeq / L or less. More preferably, it is more preferably 4000 μeq / L or more and 6000 μeq / L or less. The flow potential of the quaternary ammonium salt polymer adjusts, for example, the molecular weight of the constituent cationic monomer itself and the copolymer molar ratio of the cationic monomer constituting the copolymer and the anionic monomer or the nonionic monomer. It can be controlled by. The flow potential of the quaternary ammonium salt polymer can be measured using a flow potential measuring device (PCD04) manufactured by Spectris Co., Ltd. The specific measurement conditions are as follows. First, the hot melt that adheres each member to a commercially available napkin is invalidated by using a dryer or the like, and the napkin is decomposed into members such as a front sheet, an absorber, and a back sheet. A multi-step solvent extraction method from a non-polar solvent to a polar solvent is performed on each of the decomposed members, and the treatment agent used for each member is separated to obtain a solution containing a single composition. The obtained solution is dried and solidified, and 1H-NMR (nuclear magnetic resonance method), IR (infrared spectroscopy), LC (liquid chromatography), GC (gas chromatography), MS (mass spectrometry), GPC (gel). Permeation chromatography), fluorescent X-rays, etc. are combined to identify the structure of the treatment agent. 0.001N aqueous sodium polyethylene sulfonate solution (if the measurement sample has a negative charge) with respect to the measurement sample in which 0.001 g of the treatment agent (quaternary ammonium salt polymer) to be measured is dissolved in 10 g of physiological saline. , 0.001N aqueous solution of polydiallyl dimethylammonium chloride) is titrated, and the amount of droplets XmL required until the potential difference between the electrodes disappears is measured. Then, the flow potential of the quaternary ammonium salt polymer is calculated by the formula 1.
Flow potential = (X + 0.190 *) × 1000 ・ ・ ・ Equation 1
(* Titration required for physiological saline as a solvent)

In order for the cationic polymer to be successfully adsorbed on the surface of erythrocytes, it is advantageous that the cationic polymer easily interacts with the sialic acid present on the surface of erythrocytes. From this point of view, the present inventor has proceeded with the study and found that the value of the inorganic value / organic value, which is the ratio of the inorganic value of the substance to the organic value (hereinafter referred to as "IOB (Inorganic Organic Balance) value"). It was found that the degree of interaction between the sialic acid bond and the cationic polymer can be evaluated using the above as a scale. In detail, it has been found that it is advantageous to use a cationic polymer having an IOB value equal to or close to the IOB value of the sialic acid bond. The sialic acid conjugate is a compound in which sialic acid can exist in a living body, and examples thereof include compounds in which sialic acid is bound to the end of a glycolipid such as galactolipid.

In general, the properties of a substance are largely controlled by various intermolecular forces between molecules, and this intermolecular force mainly consists of Van der Waals force due to molecular mass and electrical affinity due to molecular polarity. If the Van der Waals force, which has a great influence on changes in the properties of substances, and the electrical affinity can be grasped individually, the properties of unknown substances or mixtures thereof can be predicted from the combination. be able to. This idea is a well-known theory as "organic conceptual diagram". For example, "Organic Analysis" by Akira Fujita (Kaniya Shoten, 1945), "Organic Qualitative Analysis: Systematic. Pure Material Edition" by Akira Fujita (Kyoritsu Publishing, 1953), Akira Fujita "Reorganized Chemical Experiments-Organic Chemistry" (Kawade Shobo, 1971), "Systematic Organic Qualitative Analysis (Mixed)" by Akira Fujita and Masami Akatsuka (Kazama Shobo, 1974), and Yoshio Koda. It is described in detail in "New Edition Organic Conceptual Diagram Basics and Applications" (Sankyo Publishing, 2008) by Shiro Sato and Yoshio Homma. In the organic conceptual diagram, regarding the physicochemical physical properties of a substance, the degree of physical properties mainly due to Van Der Wals force is called "organic", and the degree of physical properties mainly due to electrical affinity is called "inorganic". The physical characteristics of a substance are captured by a combination of "organic" and "inorganic". Then, one carbon (C) is defined as organic 20, and the inorganic and organic values of various polar groups are defined as shown in Table 1 below, and the sum of the inorganic values and the organic value are defined. The sum of the values is calculated, and the ratio of the two is defined as the IOB value. In the present invention, the IOB value of the above-mentioned sialic acid bond is determined based on these organic and inorganic values, and the IOB value of the cationic polymer is determined based on the value.

Specifically, when the cationic polymer is a homopolymer, the inorganic value and the organic value are determined based on the repeating unit of the homopolymer, and the IOB value is calculated. For example, in the case of polydiallyldimethylammonium chloride, which is a cationic polymer used in Example 1 described later, an organic value of −C− × 8 = 160, an inorganic value of Ammo and NH4 salt × 1 = 400, and Since it has an inorganic value of Ring (non-aromatic single ring) × 1 = 10, an organic value of −Cl × 1 = 40, and an inorganic value of 10, the total of the inorganic values is 400 + 10 + 10 = 420. , The total organic value is 160 + 40 = 200. Therefore, the IOB value is 420/200 = 2.10.

On the other hand, when the cationic polymer is a copolymer, the IOB value is calculated by the following procedure according to the molar ratio of the monomers used for the copolymerization. That is, the copolymer is obtained from the monomer A and the monomer B, the organic value of the monomer A is ORA, the inorganic value is INA, the organic value of the monomer B is ORB, and the inorganic value is INB. If there is, and the molar ratio of monomer A / monomer B is MA / MB, the IOB value of the copolymer is calculated from the following formula.

The IOB value of the cationic polymer thus determined is preferably 0.6 or more, more preferably 1.8 or more, further preferably 2.1 or more, and 2.2. The above is more preferable. The IOB value of the cationic polymer is preferably 4.6 or less, more preferably 3.6 or less, and even more preferably 3.0 or less. Specifically, the IOB value of the cationic polymer is preferably 0.6 or more and 4.6 or less, more preferably 1.8 or more and 3.6 or less, and 2.1 or more and 3.6 or less. It is more preferable that it is 2.2 or more and 3.0 or less. The IOB value of sialic acid is 4.25 for sialic acid alone and 3.89 for sialic acid conjugate. The sialic acid conjugate is a bond of a sugar chain and sialic acid in a glycolipid, and the sialic acid conjugate has a higher proportion of organic value and a lower IOB value than sialic acid alone.

As described above, the IOB value of the cationic polymer is preferably 40 or more, more preferably 100 or more, and further preferably 130 or more. Further, it is preferably 310 or less, more preferably 250 or less, further preferably 240 or less, and even more preferably 190 or less. For example, the organic value is preferably 40 or more and 310 or less, more preferably 40 or more and 250 or less, further preferably 100 or more and 240 or less, and further preferably 130 or more and 190 or less. Setting the organic value of the cationic polymer in this range allows the cationic polymer to be more successfully adsorbed on erythrocytes.

On the other hand, regarding the inorganic value of the cationic polymer, it is preferably 70 or more, more preferably 90 or more, further preferably 100 or more, further preferably 120 or more, and 250 or more. Is particularly preferable. Further, it is preferably 790 or less, further preferably 750 or less, further preferably 700 or less, further preferably 680 or less, and particularly preferably 490 or less. For example, the inorganic value is preferably 70 or more and 790 or less, more preferably 90 or more and 750 or less, further preferably 90 or more and 680 or less, and further preferably 120 or more and 680 or less. It is particularly preferable that it is 250 or more and 490 or less. Setting the inorganic value of the cationic polymer in this range allows the cationic polymer to be more successfully adsorbed on erythrocytes.

From the viewpoint of even more successfully adsorbing the cationic polymer to erythrocytes, it is preferable that x and y satisfy the following formula A, where x is the organic value of the cationic polymer and y is the inorganic value.
y = ax (A)
In the formula, a is preferably 0.66 or more, more preferably 0.93 or more, and even more preferably 1.96 or more. Further, a is preferably 4.56 or less, more preferably 4.19 or less, and further preferably 3.5 or less. For example, a is preferably a number of 0.66 or more and 4.56 or less, more preferably 0.93 or more and 4.19 or less, and 1.96 or more and 3.5 or less. Is more preferable. In particular, if the organic and inorganic values of the cationic polymer satisfy the above formula A, provided that the organic and inorganic values of the cationic polymer are within the above ranges, the cationic The sex polymer is more likely to interact with the sialic acid conjugate, and the cationic polymer is even more likely to be adsorbed on the erythrocytes.

From the viewpoint of effectively producing erythrocyte aggregates, the cationic polymer is preferably water-soluble. In the present invention, "water-soluble" means that 0.05 g of a powdered cationic polymer having a thickness of 1 mm or less or a film-like cationic polymer having a thickness of 0.5 mm or less is added to and mixed with 50 mL ion-exchanged water at 25 ° C. in a 100 mL glass beaker (5 mmΦ). When this is done, a stirrer chip having a length of 20 mm and a width of 7 mm is inserted, and the entire amount is dissolved in water within 24 hours under stirring at 600 rpm using a magnetic stirrer HPS-100 manufactured by AS ONE Co., Ltd. In the present invention, as the more preferable solubility, the total amount is preferably dissolved in water within 3 hours, and the total amount is more preferably dissolved in water within 30 minutes.

The cationic polymer preferably has a structure having a main chain and a plurality of side chains bonded thereto. In particular, the quaternary ammonium salt polymer preferably has a structure having a main chain and a plurality of side chains bonded thereto. The quaternary ammonium moiety is preferably present in the side chain. In this case, if the main chain and the side chain are bound at one point, the flexibility of the side chain is less likely to be inhibited, and the quaternary ammonium site present in the side chain is smoothly applied to the surface of the erythrocyte. It will be adsorbed. However, in the present invention, it is not prevented that the main chain and the side chain of the cationic polymer are bonded at two points or more. In the present invention, "bonded at one point" means that one of the carbon atoms constituting the main chain is single-bonded with one carbon atom located at the end of the side chain. .. "Bonded at two or more points" means that two or more of the carbon atoms constituting the main chain are single-bonded with two or more carbon atoms located at the ends of the side chains. Say.

When the cationic polymer has a structure having a main chain and a plurality of side chains bonded to the main chain, for example, a quaternary ammonium salt polymer has a structure having a main chain and a plurality of side chains bonded to the main chain. In the case of, the number of carbon atoms in each side chain is preferably 4 or more, more preferably 5 or more, and even more preferably 6 or more. The upper limit of the number of carbon atoms is preferably 10 or less, more preferably 9 or less, and even more preferably 8 or less. For example, the number of carbon atoms in the side chain is preferably 4 or more and 10 or less, more preferably 5 or more and 9 or less, and further preferably 6 or more and 8 or less. The carbon number of the side chain is the carbon number of the quaternary ammonium moiety (cation moiety) in the side chain, and even if carbon is contained in the anion which is a counterion, the carbon is counted. Not included. In particular, among the carbon atoms in the side chain, the number of carbon atoms from the carbon atom bonded to the main chain to the carbon atom bonded to the quaternary nitrogen is within the above range, that is, the quaternary ammonium salt. It preferred because sterically hindered becomes lower when the polymer is adsorbed on the front surface of red blood cells.

When the quaternary ammonium salt polymer is a quaternary ammonium salt homopolymer, examples of the homopolymer include polymers of vinyl-based monomers having a quaternary ammonium moiety or a tertiary amine moiety. .. When polymerizing a vinyl-based monomer having a tertiary amine moiety, a quaternary ammonium salt homozygous in which the tertiary amine moiety is quaternary ammonium-modified with an alkylating agent before and / or after polymerization. It becomes a polymer, a tertiary amine neutralizing salt in which the tertiary amine moiety is neutralized with an acid before and / or after polymerization, or a tertiary amine that has a cation in an aqueous solution after polymerization. .. Examples of alkylating agents and acids are as described above.

In particular, the quaternary ammonium salt homopolymer preferably has a repeating unit represented by the following formula 1.

Specific examples of the quaternary ammonium salt homopolymer include polyethyleneimine and the like. In addition, poly (2-methacryloxyethyl dimethylamine quaternary salt) and poly (2-methacryloxyethyl trimethylammonium salt) in which the side chain having a quaternary ammonium moiety is bonded to the main chain at one point. ), Poly (2-methacryloxyethyl dimethyl ethyl ammonium methyl sulfate), poly (2-acrylic oxyethyl dimethylamine quaternary salt), poly (2-acrylic oxyethyl trimethylamine quaternary salt), poly (2-acrylic oxy) Ethyldimethylethylammonylethyl sulfate), poly (3-dimethylaminopropylacrylamide quaternary salt), dimethylaminoethyl polymethacruate, polyallylamine hydrochloride, cationized cellulose, polyethyleneimine, polydimethylaminopropylacrylamide, polyamidine, etc. Be done. On the other hand, examples of homopolymers in which the side chain having a quaternary ammonium moiety is bonded to the main chain at two or more points include polydialyldimethylammonium chloride and polydialylamine hydrochloride.

When the quaternary ammonium salt polymer is a quaternary ammonium salt copolymer, two kinds of polymerizable monomers used for the polymerization of the above-mentioned quaternary ammonium salt homopolymer are used as the copolymer. The copolymer obtained by the above-mentioned copolymerization can be used. Alternatively, as the quaternary ammonium salt copolymer, one or more polymerizable monomers used for the polymerization of the above-mentioned quaternary ammonium salt homopolymer and a polymerizable single amount having no quaternary ammonium moiety. A copolymer obtained by copolymerizing using one or more kinds of bodies can be used. Furthermore, in addition to the polymerizable vinyl monomer, or alternatively, other polymerizable monomers, e.g., -SO 2 _- or the like can be used. As described above, the quaternary ammonium salt copolymer can be a binary copolymer or a ternary or higher copolymer.

In particular, the quaternary ammonium salt copolymer having the repeating unit represented by the above formula 1 and the repeating unit represented by the following formula 2 effectively produces agglomerates of erythrocytes. Preferred from the point of view.

Further, as the polymerizable monomer having no quaternary ammonium moiety, a cationically polymerizable monomer, an anionic polymerizable monomer, or a nonionic polymerizable monomer can be used. By using a cationically polymerizable monomer or a nonionic polymerizable monomer among these polymerizable monomers, charge cancellation with the quaternary ammonium moiety in the quaternary ammonium salt copolymer is performed. Can be effectively caused by the aggregation of erythrocytes. Examples of cationically polymerizable monomers include vinylpyridine as a cyclic compound having a cationic nitrogen atom under specific conditions, and a linear compound having a cationic nitrogen atom in the main chain under specific conditions. Examples thereof include a condensed compound of dicyandiamide and diethylenetriamine. Examples of the anionic polymerizable monomer include 2-acrylamide-2-methylpropanesulfonic acid, methacrylic acid, acrylic acid, styrenesulfonic acid, and salts of these compounds. On the other hand, examples of nonionic polymerizable monomers include vinyl alcohol, acrylamide, dimethylacrylamide, ethylene glycol monomethacrylate, ethylene glycol monoacrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, methyl methacrylate, methyl acrylate, ethyl methacrylate, and ethyl. Examples thereof include acrylate, propyl methacrylate, propyl acrylate, butyl methacrylate and butyl acrylate. As these cationically polymerizable monomers, anionic polymerizable monomers, or nonionic polymerizable monomers, one of them can be used, or any two or more of them can be used in combination. Can be done. Further, two or more kinds of cationically polymerizable monomers can be used in combination, two or more kinds of anionic polymerizable monomers can be used in combination, or two or more kinds of nonionic polymerizable monomers can be used in combination. Can also be used. A quaternary ammonium salt copolymer copolymerized using a cationically polymerizable monomer, an anionic polymerizable monomer and / or a nonionic polymerizable monomer as a polymerizable monomer has a molecular weight thereof. However, as described above, it is preferably 10 million or less, particularly preferably 5 million or less, particularly preferably 3 million or less (the same applies to the quaternary ammonium salt copolymer exemplified below).

As the polymerizable monomer having no quaternary ammonium moiety, a polymerizable monomer having a functional group capable of hydrogen bonding can also be used. When such a polymerizable monomer is used for copolymerization, and when erythrocytes are aggregated using a quaternary ammonium salt copolymer obtained from the copolymer, hard agglutinations are likely to occur, and the highly absorbent polymer has a high absorbency. Absorption performance is less likely to be impaired. Examples of functional groups capable of hydrogen bonding include -OH, -NH ₂ , -CHO, -COOH, -HF, and -SH. Examples of polymerizable monomers having a functional group capable of hydrogen bonding include hydroxyethyl methacrylate, vinyl alcohol, acrylamide, dimethylacrylamide, ethylene glycol monomethacrylate, ethylene glycol monoacrylate, hydroxyethyl methacrylate, and hydroxyethyl. Examples include acrylate. In particular, hydroxyethyl methacrylate, 2-hydroxyethyl methacrylate, hydroxyethyl acrylate, dimethylacrylamide and the like, in which hydrogen bonds work strongly, are preferable because the adsorption state of the quaternary ammonium salt polymer to erythrocytes is stabilized. These polymerizable monomers may be used alone or in combination of two or more.

As the polymerizable monomer having no quaternary ammonium moiety, a polymerizable monomer having a functional group capable of having a hydrophobic interaction can also be used. By using such a polymerizable monomer for copolymerization, the same advantageous effect as the case of using the above-mentioned polymerizable monomer having a functional group capable of hydrogen bonding, that is, the hardness of erythrocytes is obtained. The effect is that agglomerates are likely to occur. Examples of the functional group capable of having a hydrophobic interaction include an alkyl group such as a methyl group, an ethyl group and a butyl group, a phenyl group, an alkylnaphthalene group and an alkylfluoride group. Examples of polymerizable monomers having functional groups capable of hydrophobic interaction include methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, propyl methacrylate, propyl acrylate, butyl methacrylate, butyl acrylate, styrene and the like. Can be mentioned. In particular, methyl methacrylate, methyl acrylate, butyl methacrylate, butyl acrylate, etc., which have a strong hydrophobic interaction and do not significantly reduce the solubility of the quaternary ammonium salt polymer, are in the state of adsorption of the quaternary ammonium salt polymer to erythrocytes. Is preferable because it stabilizes. These polymerizable monomers may be used alone or in combination of two or more.

The molar ratio of the polymerizable monomer having a quaternary ammonium moiety to the polymerizable monomer having no quaternary ammonium moiety in the quaternary ammonium salt copolymer is the quaternary. It is preferable that the ammonium salt copolymer is appropriately adjusted so that the erythrocytes are sufficiently aggregated. Alternatively, it is preferable that the flow potential of the quaternary ammonium salt copolymer is adjusted to the above-mentioned value. Alternatively, it is preferable that the IOB of the quaternary ammonium salt copolymer is adjusted so as to have the above-mentioned value. In particular, the molar ratio of the polymerizable monomer having a quaternary ammonium moiety in the quaternary ammonium salt copolymer is preferably 10 mol% or more, more preferably 22 mol% or more, and 32 mol. It is more preferably% or more, and even more preferably 38 mol% or more. Further, it is preferably 100 mol% or less, more preferably 80 mol% or less, further preferably 65 mol% or less, and further preferably 56 mol% or less. Specifically, the molar ratio of the polymerizable monomer having a quaternary ammonium moiety is preferably 10 mol% or more and 100 mol% or less, and more preferably 22 mol% or more and 80 mol% or less. It is more preferably 32 mol% or more and 65 mol% or less, and further preferably 38 mol% or more and 56 mol% or less.

When the quaternary ammonium salt polymer is a quaternary ammonium salt polycondensate, a condensate composed of one or more monomers having the above-mentioned quaternary ammonium moiety is used as the polycondensate. The polycondensate obtained by polymerizing these condensates can be used. Specific examples include dicyandiamide / diethylenetriamine polycondensate, dimethylamine / epichlorohydrin polycondensate, and the like.

The above-mentioned quaternary ammonium salt homopolymer and quaternary ammonium salt copolymer can be obtained by a homopolymerization method or a copolymerization method of a vinyl-based polymerizable monomer. As the polymerization method, for example, radical polymerization, living radical polymerization, living cationic polymerization, living anionic polymerization, coordination polymerization, ring-opening polymerization, polycondensation and the like can be used. The polymerization conditions are not particularly limited, and the conditions for obtaining a quaternary ammonium salt polymer having a target molecular weight, flow potential, and / or IOB value may be appropriately selected.

The cationic polymer described in detail above is an example of the above-mentioned "favorable blood cell flocculant", and its effects are exhibited in Japanese Patent Application No. 2015-239286, Japanese Patent Application Laid-Open No. 2016-107100, and Japanese Patent Application Laid-Open No. 2016-107100. It can be referred to by Examples 1 to 45 described in Pamphlet International Publication No. 2016/093233 of an international application on which the application is the priority.

Further, as the blood cell flocculant to be retained in the core wrap sheet 42, a composition containing, for example, a solvent, a plasticizer, a fragrance, an antibacterial / deodorant, a skin care agent, etc., in addition to the cationic polymer (blood cell flocculant composition). ) May be given. In addition, one or more components other than the cationic polymer that can be contained in this blood cell flocculant can be mixed. As the solvent, water, a water-soluble organic solvent such as a saturated aliphatic monohydric alcohol having 1 to 4 carbon atoms, or a mixed solvent of the water-soluble organic solvent and water can be used. As the plasticizer, glycerin, polyethylene glycol, propylene glycol, ethylene glycol, 1,3-butanediol and the like can be used. As the fragrance, a fragrance having a green herbal-like fragrance described in Japanese Patent No. 4776407, a plant extract, a citrus extract and the like can be used. The antibacterial / deodorant is polymerized from a canclinite-like mineral containing an antibacterial metal described in Japanese Patent No. 4526271 and a polymerizable monomer having a phenyl group described in Japanese Patent No. 45879928. Porous polymers, quaternary ammonium salts described in Japanese Patent No. 4651392, activated carbon, clay minerals and the like can be used. As the skin care agent, a plant extract, collagen, a natural moisturizing ingredient, a moisturizer, a keratin softening agent, an anti-inflammatory agent and the like described in Japanese Patent No. 4084278 can be used.

The proportion of the blood cell flocculant contained in the blood cell cohesive sheet is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and further preferably 1% by mass or more. Further, it is preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less. The proportion of the hemagglutination agent contained in the hemagglutination sheet is preferably 0.1% by mass or more and 50% by mass or less, more preferably 0.5% by mass or more and 40% by mass or less, and 1% by mass. It is more preferably 30% by mass or less.

The proportion of the blood cell cohesive agent contained in the blood cell cohesive sheet is measured by the following method. The hemagglutination sheet is immersed in water for 60 minutes to elute the hemagglutination agent. Then, the water in which the obtained blood cell flocculant is eluted is dried and solidified. The proportion of the blood cell flocculant is determined from the mass of the dried and solidified sample. The chemical structure of the hemagglutination agent is ^{identified by 1} H-NMR or mass spectrometry (MS) alone or in combination.

The proportion of the cationic polymer in the blood cell flocculant is preferably 1% by mass or more, more preferably 3% by mass or more, and further preferably 5% by mass or more. Further, it is preferably 50% by mass or less, more preferably 30% by mass or less, and further preferably 10% by mass or less. For example, the proportion of the cationic polymer is preferably 1% by mass or more and 50% by mass or less, more preferably 3% by mass or more and 30% by mass or less, and further preferably 5% by mass or more and 10% by mass or less. preferable. By setting the ratio of the cationic polymer to the blood cell flocculant within this range, an effective amount of the cationic polymer can be imparted to the absorbent article.

The amount of the cationic polymer to be retained in the core wrap sheet 42 ^{is preferably 1 g / m 2} or more, more preferably 3 g / m ² or more, and even more preferably ^{5 g / m 2 or more.} Further, it is preferably 20 g / m ² or less, more preferably 15 g / m ² or less, and even more preferably ^{10 g / m 2 or less.} For example, the amount of cationic polymer is preferably at 1 g / m ² or more 20 g / m ² or less, further preferably 3 g / m ² or more 15 g / m ² or less, 5 g / m ² or more 10 g / m ² The following is more preferable. By applying the cationic polymer in an amount in this range, the excreted menstrual red blood cells can be effectively aggregated.

As shown in FIGS. 4 to 6, the absorbent core 41 in the present invention contains the highly absorbent polymer 43, and the blending amount of the highly absorbent polymer 43 changes in the thickness direction of the absorbent core 41. It is also preferable. In the absorbent cores 41 shown in FIGS. 4 to 6, among the core wrap sheets 42 covering the absorbent cores 41, only the skin-side portion 42a covering the skin-facing surface side of the absorbent cores 41 has holes. The blood cell flocculant is retained in the state of filling the core wrap sheet 42, but the non-skin side portion 42b covering the non-skin facing surface side of the absorbent core 41 is also filled with the pores of the core wrap sheet 42. , The hemagglutination agent may be retained.

In the absorbent core 41 shown in FIG. 4, the pulp layer 41A containing pulp fibers and not containing the highly absorbent polymer is present on the skin-facing surface 41u side of the absorbent core 41, and is non-skin-facing from the pulp layer 41A. A mixed layer 41B having pulp fibers and a highly absorbent polymer 43 is provided on the surface 41d side.
As shown in FIG. 4, when the pulp layer 41A containing no highly absorbent polymer 43 is present on the skin-facing surface 41u side of the absorbent core 41, the core wrap sheet 42 holding the hemagglutin and the highly absorbent polymer 43 are present. By increasing the distance between the erythrocytes and the above-mentioned time lag, the parts other than the erythrocytes are more reliably separated from the erythrocyte aggregates, and are absorbed by the highly absorbent polymer, resulting in an absorbent article. Absorption performance is further improved. In addition, this configuration helps the core wrap sheet to have a second water permeation rate higher than the first water permeation rate.

On the other hand, in the absorbent core 41 shown in FIG. 5, the pulp layer 41C containing pulp fibers and not containing the highly absorbent polymer is present on the non-skin facing surface 41d side of the absorbent core 41, and is more than the pulp layer 41C. A mixed layer 41B having pulp fibers and a highly absorbent polymer 43 is provided on the skin-facing surface 41u side.
Further, also in the absorbent core 41 shown in FIG. 6, the pulp layer 41C containing pulp fibers and not containing the highly absorbent polymer is present on the non-skin facing surface 41d side of the absorbent core 41, and is more than the pulp layer 41C. A mixed layer 41B having pulp fibers and a highly absorbent polymer 43 is provided on the skin-facing surface 41u side. In the absorbent core 41 shown in FIG. 6, a pulp layer 41A containing pulp fibers and not containing a highly absorbent polymer is also formed on the skin-facing surface 41u side of the absorbent core 41.

As shown in FIGS. 5 and 6, when the pulp layer 41C containing no highly absorbent polymer is present on the non-skin facing surface 41d side of the absorbent core 41, the height of the mixed layer 41B is immediately increased as soon as blood is absorbed. Since the structure allows blood to easily reach the absorbable polymer 43, it can be said that most of the highly absorbable polymer 43 easily contributes to the improvement of the absorbency of the absorbable core. In addition, when the blood that has passed through the mixed layer 41B is diffused in the pulp layer 41C containing pulp fibers and not containing the highly absorbent polymer, the mixed layer 41B releases the liquid when the product is pressurized by the movement of the user. Since it has a blocking effect, it can be said that it has an excellent wet back property.
However, in the case of such a configuration, since the highly absorbent polymer 43 is present at a position close to the liquid excretion part, high absorption before the onset of action, which was a problem when the above-mentioned hemagglutination agent was simply blended. The phenomenon of reaching the sex polymer and hindering the effective absorption of blood has become more prominent.
On the other hand, in this configuration, the blood cell flocculant on the skin side portion 42a of the core wrap sheet 42 absorbs most of the highly absorbent polymer 43 without causing the above-mentioned problem of weakening the blood cell flocculant effect. It can be said that the structure is excellent in wet-back property by contributing, and an absorbent article having excellent absorption performance can be obtained.
As described above, in both the configuration of FIG. 4 and the configuration of FIG. 5, the blood cell flocculant is held in a state of filling the pores of the core wrap sheet 42, so that the effect of improving absorption performance such as wet back property can be obtained. It is expressed more effectively.
According to the absorber 4 shown in FIG. 6, both the effect when the absorber shown in FIG. 4 is used and the effect when the absorber shown in FIG. 5 is used are exhibited.

In the absorbable article of the present invention, in addition to the core wrap sheet 42, it is preferable that the absorbable core 41 also contains a blood cell flocculant similar to the blood cell flocculant held on the core wrap sheet. By arranging the blood cell flocculant in the absorptive core, the coagulation speed can be further increased and the coagulation can be generated more firmly.
When the blood cell flocculant is arranged on the absorbable core 41, the arrangement mode of the blood cell flocculant does not have to be in a state of filling the pores of the core wrap sheet 42. Further, when arranging the absorbent core 41, it may be arranged over the entire area of the absorbent core 41 in the thickness direction, or may be arranged so as to be unevenly distributed in a specific portion in the thickness direction. For example, it may be blended in the pulp layer 41A or the mixed layer 41B of the absorber shown in FIG. 4 or the absorber shown in FIG.

Further, it is preferable that the average pore size of the absorbent core 41 is larger than the average pore size of the core wrap sheet 42 from the viewpoint that the blood cell flocculant is easily held in a state where the void portion of the core wrap sheet 42 is filled. This relationship may be satisfied with respect to the skin side core wrap sheet 42a, but may be satisfied with the non-skin side core wrap sheet 42b. Further, when a part of the agglomerates generated by the contact of menstrual blood with the blood cell aggregating agent of the skin side core wrap sheet 42a passes through the non-skin side surface of the skin side core wrap sheet 42a, it is absorbable with the core wrap sheet 42a. Since it is difficult to remain at the interface with the core 41, it is also preferable from the viewpoint of facilitating the transfer of menstrual blood to the absorber. The average pore size of the core wrap sheet 42 is an average pore size measured in a state where the blood cell flocculant is not retained or contained, or in a state where the blood cell flocculant is completely dissolved.

The method for measuring the average pore diameter of the absorbent core and the average pore diameter of the core wrap sheet 42 is as follows.
[Method of measuring the average pore diameter of the absorbent core and the average pore diameter of the core wrap sheet 42]
The pore diameter at the measurement target site is observed with a scanning electron microscope (for example, a scanning electron microscope JCM-6000 manufactured by JEOL Ltd.) at a magnification of 100 to 300 times, and has the largest diameter in contact with the pulp fiber or sheet material in the entire observation region. The diameter of the inscribed circle when the inscribed circle is geometrically drawn in the void. Ten different regions are randomly observed, and the average value of the diameters of the ten inscribed circles obtained from them is defined as the average pore diameter at the measurement target site.

The average pore diameter of the core wrap sheet 42 is preferably 10 μm or more, more preferably 30 μm or more, and preferably 150 μm or less, still more preferably 100 μm or less.
Further, from the viewpoint of keeping the pores filled, the porosity of the core wrap sheet 42 is preferably 20% or more, more preferably 30% or more, preferably 90% or less, still more preferably 70%. It is as follows. The porosity is preferably 20% or more and 90% or less, and more preferably 30% or more and 70% or less.
The ratio of the average pore size of the core wrap sheet 42 to the average pore size of the absorbent core is preferably 0.05 or more, more preferably 0.1 or more, and preferably 0.9 or less, still more preferably 0. It is less than 5.5.

Explaining the material for forming the napkin 1 described above, as the front surface sheet 2, the back surface sheet 3, and the side leakage-proof sheet 6, those usually used for absorbent articles such as sanitary napkins can be used without particular limitation. it can. For example, as the back sheet 3, a liquid-impermeable or water-repellent resin film, a laminate of the resin film and the non-woven fabric, or the like can be used. As the side leakage-proof sheet 6, a laminated non-woven fabric having high water pressure resistance, a laminated body of a resin film and a non-woven fabric, or the like can be used.

Further, as the surface sheet 2, a non-woven fabric having a single-layer or multi-layer structure, a perforated film, or the like can be used. The surface sheet 2 can be coated with various oil agents for improving liquid permeability, for example, various surfactants. When the surface sheet 2 has a multi-layer structure, the surface sheet 2 includes a first fiber layer located on the side closer to the wearer's skin and a second fiber layer located on the side farther from the wearer's skin. Both fiber layers are integrated in the thickness direction by a large number of partially formed joints, and a portion of the first fiber layer located between the plurality of joints is convex. A concavo-convex sheet that is raised to form the concavo-convex convex portion can be used. The convex portion in the concave-convex sheet may have a solid structure in which the entire surface is filled with fibers, or may have a hollow structure having a space inside. As the concavo-convex sheet having a solid structure in the convex portion, for example, those described in JP-A-2007-182662 and JP-A-2002-187228 can be used.

Further, the absorbent core 41 of the napkin 1 is entirely formed by integral molding, but it does not have to be integrally molded. For example, in the napkin of each embodiment, a pulp layer containing pulp fibers and not containing a highly absorbent polymer and a mixed layer having pulp fibers and a highly absorbent polymer 43 are laminated separately. Examples include those that are absorbent cores.

The present invention can be appropriately modified without being limited to the above embodiment. For example, the absorbent article may not have a side leak-proof sheet and a leak-proof mechanism by the side leak-proof sheet, or may not have a wing portion. Further, in the napkin shown in FIG. 1, a leak-proof groove 8 formed by embossing is formed on the surface facing the skin, but the shape of the leak-proof groove can be appropriately changed, and the leak-proof groove itself may be eliminated.
In addition, a deodorant, an antibacterial agent, or the like may be added to the absorbent core as needed. The amount of the deodorant and the antibacterial agent to be blended in the absorbent core is not particularly limited, and may be the amount normally blended in the technical field.
Further, three-dimensional guards that can stand up toward the wearer may be provided on both the left and right sides of the napkin 1 along the front-rear direction.
Further, the napkin 1 may have a rear flap portion at the lateral rear portion of the rear portion C.
The adhesive may be partially applied to the portion of the napkin 1 in contact with the underwear of the back sheet 3.
For example, the absorbent article of the present invention may be a panty liner (pantyliner) or the like in addition to a sanitary napkin.

The following absorbent articles are further disclosed with respect to the above-described embodiments of the present invention.
<1>
A liquid-permeable front sheet arranged on the skin-facing surface side, a liquid-impermeable back sheet arranged on the non-skin-facing surface side, and an absorber arranged between these sheets for menstrual blood absorption. An absorbent article, the absorber having an absorbent core containing pulp fibers and a core wrap sheet having pores and covering the absorbent core, and a skin-facing surface of the absorbent core. A water-soluble blood cell flocculant is held in the core wrap sheet covering the side in a state of filling the pores of the core wrap sheet, and when water permeates the core wrap sheet, the said An absorbent article in which the blood cell flocculant is dissolved to increase the voids in the pores.

<2>
The absorbable article according to <1>, wherein the blood cell flocculant is present in a larger amount on the skin-facing surface side of the core wrap sheet than on the non-skin-facing surface side.
<3>
The absorbent article according to <1> or <2>, wherein the core wrap sheet has a second water permeation rate higher than the first water permeation rate.
<4>
The absorbent core contains a highly absorbent polymer, and the blending amount of the highly absorbent polymer varies in the thickness direction of the absorbent core, and the pulp contains the pulp fiber and does not contain the highly absorbent polymer. The absorbent article according to any one of <1> to <3>, wherein the layer is present on the skin-facing surface side of the absorbent core.
<5>
The absorbent core contains a highly absorbent polymer, the blending amount of the highly absorbent polymer varies in the thickness direction of the absorbent core, and the pulp layer containing the pulp fibers and not containing the highly absorbent polymer is formed. The absorbent article according to any one of <1> to <4>, which is present on the non-skin facing surface side of the absorbent core.

<6>
The absorbable article according to any one of <1> to <5>, wherein the blood cell flocculant is also contained in the absorbable core.
<7>
The absorbent article according to any one of <1> to <6>, wherein the average pore diameter of the absorbent core is larger than the average pore diameter of the core wrap sheet.
<8>
The absorbent article according to any one of <1> to <7>, wherein the average fiber density of the absorbent core is smaller than the average fiber density of the core wrap sheet.
<9>
In any one of <1> to <8>, in which 10% or more of the area of the pores in the entire surface area of the core wrap sheet on the side facing the skin is filled with the blood cell flocculant. The absorbent article described.
<10>
The absorbable article according to any one of <1> to <9>, wherein the blood cell flocculant is in a state in which 10% or more of the total volume of the voids of the core wrap sheet is filled with the blood cell flocculant.

<11>
The absorbent article according to any one of <1> to <10>, wherein the core wrap sheet is a sheet made of cellulosic fibers.
<12>
The pores of the core wrap sheet have a structure in which the pores of the core wrap sheet are communicated with each other in the thickness direction of the core wrap sheet, and the network structure of interfiber voids in which the gaps between fibers are three-dimensionally connected by the communicated pores. The absorbent article according to any one of <1> to <11>.
<13>
The absorbent article according to any one of <1> to <12>, wherein the core wrap sheet has an average pore diameter of 10 μm or more and 150 μm or less.
<14>
The absorbability according to any one of <1> to <13>, wherein 10% or more and 100% or less of the area of the pores in the entire surface area of the core wrap sheet is filled with the blood cell flocculant. Goods.
<15>
The absorbent article according to any one of <1> to <14>, wherein the ratio of the volume of the core wrap sheet filled with the blood cell flocculant is 10% or more and 90% or less.

<16>
The absorption according to any one of <1> to <15>, wherein the core wrap sheet has a pH of a water extract measured by JIS P833-1: 2013 of 3.5 or more and 9.0 or less. Sex goods.
<17>
The absorbent article according to any one of <1> to <16>, wherein the surface sheet is partially bonded to the core wrap sheet.
<18>
Any of the above <1> to <17>, wherein the core wrap sheet has a leak-proof groove formed in a groove shape together with the surface sheet on the laterally outer side of the excretion facing portion facing the excretion portion of the wearer. The absorbent article according to 1.
<19>
The core wrap sheet according to <18>, wherein the core wrap sheet has a leak-proof groove integrated with the surface sheet and the absorbent core at a side portion along the vertical direction and an end portion along the horizontal direction. Absorbent article.

<20>
The absorbent article according to <19>, wherein the leak-proof groove is in a state in which its constituent fibers are heat-sealed.
<21>
The absorbent article according to any one of <1> to <20>, wherein the surface sheet is made of a non-woven fabric having irregularities on the side facing the skin.
<22>
The absorbent article according to any one of <1> to <21>, wherein the absorbent core is integrally molded.
<23>
The absorbent article according to any one of <1> to <22>, wherein the absorbent core contains a highly absorbent polymer.
<24>
The absorbent article according to any one of <1> to <23>, wherein the absorbent core contains a deodorant or an antibacterial agent.

<25>
The absorbent article according to any one of <1> to <24>, which has a pair of wing portions on both sides in the vertical direction corresponding to the front-back direction of the wearer.
<26>
The absorbent article according to any one of <1> to <25>, which has a rear flap portion at the rear portion in the lateral direction of the rear portion.
<27>
The absorbent article according to any one of <1> to <26>, which is provided with a three-dimensional guard that can stand up toward the wearer on both the left and right sides along the front-rear direction.
<28>
The absorbent article according to any one of <1> to <27>, wherein the adhesive is partially applied to the portion of the absorbent article in contact with the underwear of the back sheet.
<29>
The absorbable article according to any one of <1> to <28>, wherein the blood cell flocculant has a property of starting dissolution within 3 minutes from the time of contact with physiological saline.
<30>
A liquid-permeable front sheet arranged on the skin-facing surface side, a liquid-impermeable back sheet arranged on the non-skin-facing surface side, and an absorber arranged between these sheets for menstrual blood absorption. An absorbent article, the absorber having an absorbent core containing pulp fibers and a core wrap sheet having pores and covering the absorbent core, and a skin-facing surface of the absorbent core. A water-soluble cationic polymer is held in the core wrap sheet covering the side in a state of filling the pores of the core wrap sheet, and when water permeates the core wrap sheet, the said An absorbent article in which the cationic polymer is dissolved to increase the voids in the pores.
<31>
The absorbent article according to <30> above, wherein the cationic polymer is a quaternary ammonium salt homopolymer, a quaternary ammonium salt copolymer, or a quaternary ammonium salt polycondensate.
<32>
The cationic polymer has a molecular weight of 10,000 or more and 22 million or less, a flow potential of 1500 μeq / L or more and 13000 μeq or less, and an inorganic / organic value of 0.6 or more and 4.6 or less. 31>.
<33>
A liquid-permeable front sheet arranged on the skin-facing surface side, a liquid-impermeable back sheet arranged on the non-skin-facing surface side, and an absorber arranged between these sheets for menstrual blood absorption. An absorbent article, the absorber having an absorbent core containing pulp fibers and a core wrap sheet having pores and covering the absorbent core, and a skin-facing surface of the absorbent core. An absorbent article in which a water-soluble blood cell flocculant is present on the skin-facing surface side of the core wrap sheet in a larger amount than on the non-skin-facing surface side.

Hereinafter, the absorbent article of the present invention will be described in more detail with reference to Examples. However, the scope of the present invention is not limited by such examples.

<Example 1>
Sanitary napkins of the forms shown in FIGS. 1 and 2 were prepared and used as samples of Example 1. The thickness of the sanitary napkin was 1.9 mm. As shown in FIG. 5, the absorber 4 has a configuration in which the absorbent core 41 is wrapped with one core wrap sheet 42 from the skin facing surface side to the non-skin facing surface side. As the surface sheet 2, the non-woven fabric used in Kao Corporation's Lorier Skin Clean Guard (usually with wings for daily use) was used. As the back sheet 3, a non-breathable resin film was used. The absorbent core 41 is a laminated absorbent core in which a mixed laminated fiber containing wood pulp fibers and a highly absorbent polymer is arranged on a skin-facing surface, and an absorbent core composed of only wood pulp fibers is arranged on a non-skin facing surface. Was used. In the mixed fiber structure, the basis weight of the wood pulp fiber was 100 g / m ² , and the basis weight of the highly absorbent polymer was 56 g / m ² . As the highly absorbent polymer, a general-purpose grade high-absorbent polymer for hygiene products manufactured by Nippon Shokubai Co., Ltd. was used.
As the core wrap sheet 42, a thin paper having a basis weight of 16 g / m ² and a thickness of 0.3 mm was used. 5.00 g of the hemagglutination agent of the following formulation is dissolved in 100 g of ion-exchanged water, and a solution containing the hemagglutination agent is ^{immersed in a core wrap sheet so as to have a basis weight of 120 g / m 2} , and then the core wrap is used. The sheet 42 was dried by leaving it in a dryer for 24 hours in an environment of 60 ° C., and the dried core wrap sheet contained a hemagglutination agent of 6 g / m ² . The viscosity of the solution containing the blood cell flocculant at the time of impregnation was 4.0 mPa · s. The cationic polymer contained in the blood cell flocculant is polydialyldimethylammonium chloride, which is a water-soluble quaternary ammonium salt homopolymer (trade name: Marcoat 106 (weight average molecular weight: 15,000) manufactured by Lubrizol Japan, Inc.). ) Was used.
[Prescription of blood cell flocculant]
Polydialyldimethylammonium chloride obtained by drying Marquardt 106 (weight average molecular weight: 15,000, flow potential: 6700 μeq / L)

The core wrap sheet 42 has a first water permeability of 0.28 g / sec, a second water permeation rate of 1.15 g / sec, and a ratio of the second water permeation rate to the first water permeation rate (second water permeation rate / first water permeation rate). The speed) was 4.1. In the core wrap sheet 42, more blood cell flocculants were present on the side facing the skin. Further, in the sanitary napkin of Example 1, the average pore diameter of the absorbent core was larger than the average pore diameter of the core wrap sheet.
<Example 2>
As the configuration shown in FIG. 4, in Example 1, a mixed product fiber containing wood pulp fibers and a highly absorbent polymer is used for the absorbent core 41, and a fiber single layer containing no highly absorbent polymer is used. The formulation was the same as in Example 1 except that the fiber was changed to the one on the side facing the skin. In the sanitary napkin of Example 2, the average pore size of the absorbent core was larger than the average pore size of the core wrap sheet.

<Examples 3 to 5>
A sanitary napkin was prepared in the same manner as in Example 1 except that the formulation of the hemagglutination agent was replaced as follows.
Example 3: Polydialyldimethylammonium chloride obtained by drying the trade name PAS-H-5L manufactured by Nittobo Medical Co., Ltd. (weight average molecular weight: 30,000, flow potential 7447 μeq / L, IOB2.1)
Example 4: Polydialyldimethylammonium chloride obtained by drying the trade name Marcoat 100 manufactured by Lubrizol Japan, Inc. (weight average molecular weight 150,000, flow potential 7488 μeq / L, IOB2.1).
Example 5: Polydiallyldimethylammonium chloride (weight average molecular weight: 400,000 to 500,000, flow potential 6827 μeq / L, IOB2.1) obtained by drying a poly (diallyldimethylammonium chloride) solution manufactured by Aldrich. )

<Comparative example 1>
A sanitary napkin was prepared in the same manner as in Example 1 except that a core wrap sheet that did not retain a blood cell flocculant was used, and this was used as a sample of Comparative Example 1. The thickness of the sanitary napkin is 1.9 mm.
<Comparative example 2>
A mixed product fiber having a core wrap sheet that does not retain a blood cell flocculant and an absorbent core having a basis weight of wood pulp fiber of 300 g / m ² and a basis weight of a highly absorbent polymer of 15 g / m ^2. A sanitary napkin having a thickness of 4.2 mm was prepared in the same manner as in Example 1 except that the above was used, and this was used as a sample of Comparative Example 2.

FIG. 7A shows an electron microscope (SEM) photograph of the core wrap sheet used in Examples 1 and 2 before the hemagglutination agent was applied, and FIG. 7B shows the hemagglutination agent applied. The electron microscope (SEM) photographs of the core wrap sheets used in Examples 1 and 2 after the above are shown in FIG. 7 (c), in which the blood cell flocculant is held in a state of filling the pores. The electron microscope (SEM) photograph after water permeation through the core wrap sheet used in 1 and 2 (after the first water permeation) is shown.

[Evaluation]
For the samples of Examples 1 to 5 (sanitary napkins) and the samples of Comparative Examples 1 and 2 (sanitary napkins), the dynamic maximum absorption amount, the wetback amount (liquid return amount), and the product flexibility (feel sensory evaluation). Was evaluated by the following method. The results are shown in Table 2 below.

<Dynamic maximum absorption amount>
A sample of sanitary napkin was fixed to the sanitary shorts and attached to a dynamic model of the human body. The walking motion of the dynamic model was started, and 1 minute after the start of the walking motion, 2 g of pseudo blood was injected from the part facing the excretory part (first time). Further, 3 g of pseudo blood was injected 3 minutes after the completion of the first liquid injection (second time). Furthermore, 2 g of pseudo blood was injected 3 minutes after the completion of the second liquid injection (third time). The third and subsequent injections of the liquid were repeated 3 minutes after the injection of the liquid, and 2 g of pseudo blood was repeatedly injected, and the injection was completed when the liquid exuded from the wing portion of the sanitary napkin to obtain the maximum dynamic absorption amount.
As described in the present specification, the simulated blood is measured using a B-type viscometer (model number TVB-10M manufactured by Toki Sangyo Co., Ltd., measurement conditions: rotor No. 19, 30 rpm, 25 ° C., 60 seconds). The blood cell / plasma ratio of defibrated horse blood (manufactured by Nippon Biotest Research Institute Co., Ltd.) was prepared so that the resulting viscosity would be 8 mPa · s.

<Amount of wet back>
Place the sanitary napkin sample horizontally so that the surface sheet is on the front side, stack a cylindrical acrylic plate with an injection port with a diameter of 1 cm on the bottom, inject 6 g of pseudo blood from the injection port, and after injection. The state was held for 1 minute. Next, the acrylic plate with a cylinder was removed, and 16 sheets of absorbent paper (commercially available tissue paper) measuring 6 cm in length × 9.5 cm in width and having a basis weight of 13 g / m ^{2 were placed on the surface of the surface sheet.} Further, a weight was placed on the weight so that the pressure was 20 × 98 Pa (20 gf / cm ² ), and the pressure was applied for 5 seconds. After pressurization, the absorbent paper was taken out, and the weight of the absorbent paper after pressurization was measured. By subtracting the weight of the absorbent paper before pressurization from the weight of the absorbent paper after pressurization, the mass of simulated blood absorbed by the paper was calculated and used as the surface liquid return amount.

<Product flexibility sensory evaluation>
With the napkins obtained in Examples and Comparative Examples invisible (put in a box), let 10 monitors touch the product to evaluate its flexibility. Using the product of Comparative Example 2 as the standard of flexibility, compared to Comparative Example 1, the case of being extremely flexible is 5, the case of being flexible is 4, the case of being the same is 3, the case of being hard is 2, and the case of being extremely hard. A comparative evaluation is performed as 1. The average value for 10 people is "A" when it is 4.0 or more, "B" when it is in the range of 3.5 or more and less than 4.0, and the range of more than 2.5 and less than 3.5. The case where becomes "C" is defined.
The product of Comparative Example 2 was also subjected to sensory evaluation in comparison with Comparative Example 2 which is the same sample.

As is clear from FIGS. 7 (a) to 7 (c), the core wrap sheet used in Examples 1 and 2 is held in a state where the blood cell flocculant fills the pores, and the core wrap sheet is moistened. Upon permeation, the blood cell flocculant held in the vacancies filled was dissolved and the voids in the vacancies increased. As a result, according to Table 2, the sanitary napkins of Example 1 and Example 2 have an increased dynamic maximum absorption amount and a reduced wetback amount as compared with the sanitary napkin of Comparative Example 1. The absorption performance is improved. On the other hand, comparing the sanitary napkins of Examples 1 and 2 with the sanitary napkins of Comparative Example 2, the sanitary napkin of Example 1 is compared with the sanitary napkin of Comparative Example 2 as a product. It is a so-called "ultra-slim type" whose thickness has been significantly reduced from 4.2 mm to 1.9 mm, and it is considered that there is a difference in product flexibility and sensory evaluation. Despite the reduction in materials in this way, the difference in dynamic maximum absorption is small.

Further, when comparing Example 1 and Example 2, the amount of wet back is smaller in Example 2. It is considered that this is because the effect of the blood cell flocculant on the absorption performance due to the arrangement of the fiber single layer containing no highly absorbent polymer on the side facing the skin is more highly exhibited.
From this, it can be seen that according to the absorbable article of the present invention, the effect of improving the absorption performance by the blood cell flocculant is effectively exhibited, and excellent absorption performance is exhibited. In addition, it can be seen that the absorption performance can be dramatically improved without changing the thinness, and the absorption performance can be maintained at a certain level or higher while the thickness can be significantly reduced.

<Examples 6 to 10>
Example 1 except that the mixed fiber of the absorbent core used in Examples 1 to 5 was changed to a ^{basis weight of wood pulp fiber of 280 g / m 2} and a basis weight of a highly absorbent polymer of 29 g / m ^2. A sanitary napkin having a thickness of 4.2 mm was prepared in the same manner as in the above. The dynamic maximum absorption amount and the wetback amount were measured by the above-mentioned methods and are shown in Table 3.

<Comparative example 3>
The mixed fiber structure of the absorbent core used in Comparative Example 1 was the same as in Comparative Example 1 except that the basis weight of the wood pulp fiber was changed to ^{280 g / m 2} and the basis weight of the highly absorbent polymer ^{was changed to 29 g / m 2.} A sanitary napkin having a thickness of 4.2 mm was prepared. The dynamic maximum absorption amount and the wetback amount were measured by the above-mentioned methods and are shown in Table 3.

As shown in Table 3, even a "normal slim type" sanitary napkin having a thickness of 4.2 mm does not contain a hemagglutinant for suppressing the dynamic maximum absorption amount and the liquid return amount (comparative example). It can be seen that it is improved compared to 3). As in Examples 1 to 5 described above, the present invention is very effective in reducing the thickness of the absorbent article to improve the wearing feeling and improving the liquid absorption performance, but as in Examples 6 to 10. It is also effective in improving the liquid absorption performance in thick absorbent articles.

[Test Example 1]
Pulp paper with a basis weight of 25 g / m ² (pulp: Caribbean type, thickness: 0.326 mm (0.5 g / cm under ² loads), 0.5 g / cm ^{bulk density under 2} loads: 0.08 g / cm ³ ) A blood cell flocculant was applied to one surface. As a blood cell flocculant, polydiallyldimethylammonium chloride (Japan Lubrizol Co., Ltd., trade name "Marcoat 100", weight average molecular weight 150,000), which is a water-soluble quaternary ammonium salt homopolymer, was used. A solution having a viscosity of 15500 mPa · s was prepared by dissolving 10 g of the blood cell flocculant in 25 g of water. This solution was applied with a brush over the entire non-skin facing surface of the paper so as to have the basis weight shown in Table 4 below. In this way, a hemagglutination sheet was obtained.

[Test Examples 2-9]
The blood cell flocculant was applied as shown in Table 4 below. A hemagglutination sheet was obtained in the same manner as in Test Example 1 except for this.

[Test Examples 10 to 12]
As the blood cell flocculant, polydiallyldimethylammonium chloride (Senka Co., Ltd., trade name "Unisense FPA1002L", weight average molecular weight 600,000), which is a water-soluble quaternary ammonium salt homopolymer, was used. A solution having a viscosity of 749 mPa · s was prepared by dissolving 10 g of the blood cell flocculant in 55.6 g of water. This solution was applied to the same paper as the paper used in Test Example 1 with a brush so as to have the basis weight shown in Table 5 below. In this way, a hemagglutination sheet was obtained.

[Test Examples 13 and 14]
As a blood cell flocculant, a water-soluble quaternary ammonium salt homopolymer, polydimethylaminoethyl diethyl sulfate (Kao Corporation, trade name "Kaosera MD-P", weight average molecular weight 56,000) is used. There was. A solution having a viscosity of 189 mPa · s was prepared by dissolving 10 g of the blood cell flocculant in 27.8 g of water. This solution was applied to the same paper as the paper used in Test Example 1 with a brush so as to have the basis weight shown in Table 5 below. In this way, a hemagglutination sheet was obtained.

[Evaluation 1]
A model experiment on blood permeation was performed using the hemagglutination sheet obtained in the test example. Two cylinders with an inner diameter of 35 mm were used, and these two cylinders were arranged in series along the vertical direction, and a hemagglutination sheet was sandwiched between them. At this time, the skin-facing surface side of the hemagglutination sheet was oriented vertically upward. 3 g of pseudo blood was poured into the cylinder located on the upper side, and after 20 seconds, the amount of simulated blood accumulated in the cylinder located on the lower side was measured. This operation was repeated two more times, and the amount of simulated blood accumulated in the cylinder located on the lower side was measured each time. The liquid permeability of the hemagglutination sheet was evaluated using this amount as a scale. As described in the present specification, the simulated blood is prepared using a B-type viscometer (manufactured by Toki Sangyo Co., Ltd., model number TVB-10M, measurement conditions: rotor No. 19, 30 rpm, 25 ° C., 60 seconds). The blood cell / plasma ratio of defibrated horse blood (manufactured by Nippon Biotest Co., Ltd.) was adjusted so that the measured viscosity was 8 mPa · s. Hereinafter, the term "pseudo-blood" is used in this sense.

[Evaluation 2]
The highly absorbent polymer was swelled by the following procedure using the simulated blood permeated through the hemagglutination sheet obtained in the above [Evaluation 1], and the volume swelling ratio was measured by the following method. One grain of a highly absorbent polymer having a diameter of about 400 μm is placed on a slide glass, and 3 drops of each collected blood are dropped onto the highly absorbent polymer by a pasteur pipette, and blood is added to the highly absorbent polymer. Was absorbed and swollen. Crosslinked sodium polyacrylate was used as the highly absorbent polymer. After dropping the blood, a small screw lid was used to seal the highly absorbent polymer to prevent evaporation of water. After 10 minutes, the lid was removed, and an excess amount of pseudo blood was absorbed and removed using an absorbent paper. Subsequently, the diameter of the highly absorbent polymer was measured by light microscopy. When the diameter of the highly absorbent polymer before swelling is R ₁ (μm) and the diameter after swelling is R ₂ (μm), the volume swelling ratio is defined by _{(R 2} / R ₁ ) ^3. The larger the value of the volume swelling ratio, the more the highly absorbent polymer absorbed a large amount of liquid.

As is clear from the results shown in Tables 4 and 5, the hemagglutination sheet obtained in each test example had a high volume swelling ratio of the highly absorbent polymer to the same extent. The volume swelling magnification of superabsorbent polymer when evaluated in the same manner as in Test Example 1 without adding the hemagglutination agent is 12.2 times. Furthermore, the blood cell aggregating sheet in which the blood cell aggregating agent is unevenly distributed on the non-skin facing surface side is more frequent than the sheet in which the blood cell aggregating agent is unevenly distributed on the skin facing surface side after the second permeation of pseudo blood. It can be seen that even if the amount is increased, the permeation amount of pseudo blood for 20 seconds does not decrease, and the volume swelling ratio of the highly absorbent polymer can be compatible. Further, it can be seen that the degree of decrease in the permeation amount of the liquid is small while maintaining the absorption amount of the pseudo blood.

Further, as is clear from each test example, in the blood cell aggregating sheet in which the blood cell aggregating agent is unevenly distributed on the side facing the skin, the permeation amount of pseudo blood decreases as the number of times increases, but the volume swelling of the highly absorbent polymer The magnification is as good as the hemagglutination sheet in which the blood cell flocculant is unevenly distributed on the non-opposing surface side. That is, it is suggested that even when such a hemagglutination sheet is used for a napkin, the plasma component can pass through the hemagglutination sheet and be sufficiently absorbed by the highly absorbent polymer of the absorbable core.

1 Sanitary napkin (absorbent article)
2 Front sheet 3 Back sheet 4 Absorbent 5 Absorbent body 6 Side leak-proof sheet 7 Wing part 41 Absorbent core 41A, 41C Pulp layer 41B Mixed layer 42 Core wrap sheet 42a Skin side part 42b Non-skin side part 43 High absorbency Polymer 8 leak-proof groove

Claims (9)

A liquid-permeable front sheet arranged on the skin-facing surface side, a liquid-impermeable back sheet arranged on the non-skin-facing surface side, and an absorber arranged between these sheets for menstrual blood absorption. It is an absorbent article
The absorber has an absorbent core containing pulp fibers and a core wrap sheet having pores and covering the absorbent core.
A water-soluble blood cell flocculant is held in a state in which the pores of the core wrap sheet are filled in the core wrap sheet that covers the skin-facing surface side of the absorbent core.
When water permeates the core wrap sheet, the blood cell flocculant dissolves and the voids in the pores increase .
The absorbent core contains a highly absorbent polymer, and the blending amount of the highly absorbent polymer varies in the thickness direction of the absorbent core, and the pulp contains the pulp fiber and does not contain the highly absorbent polymer. An absorbent article in which the layer is present on the skin-facing side of the absorbent core. The absorbable article according to claim 1, wherein the blood cell flocculant is present in a larger amount on the skin-facing surface side of the core wrap sheet than on the non-skin-facing surface side. The absorbent article according to claim 1 or 2, wherein the core wrap sheet has a second water permeation rate higher than the first water permeation rate. Said absorbent core, before Symbol pulp layer that does not contain the superabsorbent polymer comprises a pulp fiber is present in the non-skin facing side of the absorbent core, or any claim 1-3 1 Absorbent articles described in the section. The absorbable article according to any one of claims 1 to 4 , wherein the blood cell flocculant is also contained in the absorbable core. The absorbent article according to any one of claims 1 to 5 , wherein the average pore diameter of the absorbent core is larger than the average pore diameter of the core wrap sheet. A liquid-permeable front sheet arranged on the skin-facing surface side, a liquid-impermeable back sheet arranged on the non-skin-facing surface side, and an absorber arranged between these sheets for menstrual blood absorption. It is an absorbent article
The absorber has an absorbent core containing pulp fibers and a core wrap sheet having pores and covering the absorbent core.
A water-soluble cationic polymer is held in a state in which the pores of the core wrap sheet are filled in the core wrap sheet that covers the skin-facing surface side of the absorbent core.
When water permeates the core wrap sheet, the cationic polymer dissolves and the voids in the pores increase .
The absorbent core contains a highly absorbent polymer, and the blending amount of the highly absorbent polymer varies in the thickness direction of the absorbent core, and the pulp contains the pulp fiber and does not contain the highly absorbent polymer. An absorbent article in which the layer is present on the skin-facing side of the absorbent core. The absorbent article according to claim 7 , wherein the cationic polymer is a quaternary ammonium salt homopolymer, a quaternary ammonium salt copolymer, or a quaternary ammonium salt polycondensate. The cationic polymer has a molecular weight of 10,000 or more 22 million or less, streaming potential is 1500Myueq / L or more 13000μeq less, and the inorganic value / organic value is 0.6 to 4.6, according to claim 8 Absorbent article.

Images