JP6762142B2 - Absorbent article - Google Patents

Description

The present invention relates to an absorbent article useful as a female absorbent article used for absorption of menstrual blood.

Women's absorbable articles such as sanitary napkins and panty liners have high menstrual blood absorption performance, and it is desired that menstrual blood excreted on the surface sheet be rapidly absorbed by the absorber inside the article. However, menstrual blood during menstruation is difficult to be absorbed because it has a higher viscosity than urine, which is the main absorption target of disposable diapers. Especially, menstrual blood with high viscosity remains on the surface sheet without being absorbed. May induce blood leakage.

Regarding the technique relating to the absorption performance of menstrual blood, there is known a technique of applying a fluid treatment agent that reacts with blood to an absorbent article to improve the absorption performance of menstrual blood of the absorbent article. For example, Patent Document 1 describes personal care absorbent articles such as napkins and tampons, including a porous non-woven web material that has been treated with a treatment agent that clumps or dissolves red blood cells in the blood. .. In the same document, a polycation material, which is a strongly positively charged polymer, is used as this treatment agent. This treatment agent aggregates or lyses red blood cells in the blood as it enters or passes through the absorbent article. Further, Patent Document 2 uses a napkin to which a blood gelling agent containing a copolymer having a maleic anhydride group is applied, and Patent Document 3 uses a metal salt compound such as copper or iron or an inorganic compound such as silica as a blood coagulant. The absorbent articles used as are listed respectively. As described in Patent Documents 1 to 3, these blood treatment agents are usually applied to a surface sheet or a member farther from the wearer's skin, such as an absorber, in an absorbent article.

In addition, by forming a high-density part on the absorbent article by compression processing such as embossing, the leakage-proof property of the absorbed excrement liquid is improved, the wearing feeling is improved by reducing the thickness, and the absorbent article is being worn. Deformation can be controlled. Patent Documents 4 and 5 describe absorbent articles in which a high-density portion is formed on the surface sheet side for this purpose.

Further, there are various patterns for forming a high-density portion by compression processing. For example, in Patent Document 4, in a plan view, a circular or elliptical embossed recess has a zigzag pattern and a rectangular or rhombic eye. A grid pattern, a honeycomb pattern having hexagonal eyes, and the like are described, and Patent Document 5 describes a combination pattern of a curved squeezed groove and a punctate squeezed portion. In general, the high-density part by compression processing is harder and less comfortable to the touch than the part not subjected to compression processing. Therefore, the excretion part arranged in the excretion part of the wearer, for example, the part where the touch is particularly important. It is usually not formed on the facing portion, and this is also done in the absorbent articles described in Patent Documents 4 and 5.

Special Table 2002-528232 Japanese Unexamined Patent Publication No. 57-153648 Japanese Unexamined Patent Publication No. 2005-287997 Japanese Unexamined Patent Publication No. 2003-33397 JP-A-2010-148708

The present inventors have found that some blood treatment agents useful for improving the absorption performance of menstrual blood in an absorbable article may form a hard film when applied. Then, the present inventors control deformation of the absorbent article during wearing due to the fact that when the blood treatment agent having such properties is applied to the constituent members of the absorbent article, the applied portion is hardened. It was also found that there was a problem that it became difficult and the skin contact became worse. For example, when a blood treatment agent is applied to an absorber in a sanitary napkin and its surrounding components and hardened, an external force is applied to the napkin due to the movement of the wearer's body while wearing the napkin. Occasionally, the napkin may break at an unintended part to cause unexpected deformation, which may cause a decrease in wearing feeling or leakage. The control of deformation of the absorbent article due to the blood modifying agent during wearing is not described in any of Patent Documents 1 to 5.

An object of the present invention is to provide an absorbable article having excellent menstrual blood absorption performance, good skin contact and excellent wearing feeling.

The present invention has a vertical direction corresponding to the anterior-posterior direction extending from the ventral side of the wearer to the dorsal side via the crotch portion and a lateral direction orthogonal to the vertical direction, and is arranged in the crotch portion at the time of wearing. The crotch having the excretion portion facing portion arranged opposite to the excretion portion in the above, the front portion arranged on the ventral side of the wearer from the crotch portion, and the back side of the wearer from the crotch portion. A component having a rear portion in the vertical direction and capable of absorbing menstrual blood and a surface sheet arranged on the skin-facing surface side of the absorber and capable of contacting the wearer's skin when worn are provided as constituent members. Blood cells aggregate on at least one of the constituent members of the absorbent article, which is an absorbent article and is arranged on the non-skin facing surface side surface layer portion of the surface sheet and a position farther from the wearer's skin. Absorption in which the agent is contained and a high-density portion having a higher density than the portion of the absorber located in the portion facing the excretion portion of the absorber is formed in a portion of the absorber not located in the portion facing the excretion portion. It provides sex goods.

According to the present invention, there is provided an absorbable article having excellent menstrual blood absorption performance, good skin contact and excellent wearing feeling.

FIG. 1 is a plan view showing a skin-facing surface side (surface sheet side) of a sanitary napkin according to an embodiment of the absorbent article of the present invention. FIG. 2 is a cross-sectional view schematically showing the cross section taken along the line II of FIG. 3 (a) to 3 (e) are plan views schematically showing the pattern of the high-density portion according to the present invention, respectively. FIG. 4 is a schematic view showing the absorption mechanism of menstrual blood in the absorbable article of the present invention. 5 (a) and 5 (b) are schematic views showing the absorption mechanism of menstrual blood in a conventional absorbent article.

Hereinafter, the absorbent article of the present invention will be described with reference to the drawings based on its preferred embodiment. 1 and 2 show a sanitary napkin 1, which is an embodiment of the absorbent article of the present invention. As shown in FIG. 1, the napkin 1 has a longitudinal direction X corresponding to the front-rear direction extending from the ventral side of the wearer to the dorsal side via the crotch portion and a lateral direction Y orthogonal to the longitudinal direction X, and when worn, the napkin 1 has the same. The crotch part B having the excretion part facing portion B1 arranged in the crotch part and facing the excretion part such as the vaginal opening in the crotch part, and the crotch part B arranged on the ventral side, that is, the front side of the wearer from the crotch part B An absorber 4 having an anterior portion A and a posterior portion C arranged on the back side, that is, the posterior side of the wearer from the crotch portion B in the longitudinal direction X and capable of absorbing menstrual blood, and the absorber 4 A surface sheet 2 which is arranged on the side facing the skin of the body and which can come into contact with the wearer's skin when worn is provided as a constituent member.

In the present specification, the "skin facing surface" refers to a surface of the absorbent article or a component such as the absorber 4 that is directed toward the wearer's skin when the absorbent article is worn, that is, relatively to the wearer's skin. The near side, the "non-skin facing surface", is the surface of the absorbent article or its constituents that faces the side opposite to the skin side when the absorbent article is worn, that is, the side that is relatively far from the wearer's skin. Is. The term "when worn" as used herein means a state in which the normal proper wearing position, that is, the correct wearing position of the absorbent article is maintained, and the absorbent article is in a state deviated from the wearing position. Does not include.

As shown in FIGS. 1 and 2, the napkin 1 includes a front surface sheet 2 forming a skin facing surface, a back surface sheet 3 forming a non-skin facing surface, and an absorber 4 interposed between both sheets 2 and 3. It includes an absorbent body 5 to be provided. The absorbent body 5 is divided into three regions, anterior portion A, a crotch lower portion B, and a posterior portion C, in order from the ventral side of the wearer in the vertical direction X. The vertical direction X corresponds to the longitudinal direction of the napkin 1 and the absorbent body 5, and the lateral direction Y corresponds to the width direction orthogonal to the longitudinal direction of the napkin 1 and the absorbent body 5.

As shown in FIG. 2, the surface sheet 2 covers the entire surface of the absorber 4 facing the skin, and further extends outward in the lateral direction Y from both side edges of the absorber 4 along the vertical direction X. On the other hand, the back surface sheet 3 covers the entire non-skin facing surface of the absorber 4, and further extends outward from both side edges along the vertical direction X of the absorber 4 in the horizontal direction Y, so that the absorber of the front sheet 2 A side flap portion 5S is formed together with a side sheet 6 described later at a position further outward in the lateral direction Y than the extending portions from both side edges of the 4. The back surface sheet 3 and the side sheet 6 are bonded to each other by known bonding means such as an adhesive, a heat seal, and an ultrasonic seal at the extending portions from both side edges of the absorber 4 along the vertical direction X. Further, the front surface sheet 2 and the back surface sheet 3 are joined to each other by known joining means at the extending portions from both ends of the absorber 4 in the vertical direction X. Each of the front surface sheet 2 and the back surface sheet 3 and the absorber 4 may be bonded by an adhesive. As the front surface sheet 2 and the back surface sheet 3, various materials conventionally used for absorbent articles such as sanitary napkins can be used without particular limitation. For example, 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. As the back sheet 3, a moisture-permeable resin film or the like can be used.

The surface sheet 2 may have irregularities having solid or hollow convex portions on the skin contact surface side, or may have an oil agent attached to the surface of the constituent fibers. The surface sheet 2 is preferably hydrophilic as a whole, and at least the overlapping portion where the hemagglutination agent arrangement portion described later and the formation portion of the grooves 7 and 8 described later on the surface sheet 2 overlap in a plan view. Is preferably hydrophilic. When at least such an overlapping portion of the surface sheet 2 is hydrophilic, the groove 7 that overlaps a part or the whole of the arrangement portion of the hemagglutination agent when the hydrophilic menstrual blood diffuses in the absorber 4. Menstrual blood can be efficiently diffused even in 1 and 8. As will be described later, the hemagglutinin is contained in the surface sheet 2 and in the constituent members (for example, the core wrap sheet 41 described later) arranged at a position farther from the wearer's skin than the surface sheet 2. The "placement portion of the hemagglutinin" includes both of these cases. Examples of the method of making the whole or a part of the surface sheet 2 hydrophilic include a method of using a hydrophilic non-woven fabric for the hydrophilic portion. Examples of this hydrophilic non-woven fabric include non-woven fabrics mainly composed of cellulose-based fibers such as wood pulp fibers, rayon fibers, cotton fibers, and cellulose acetate fibers; polyolefin-based fibers such as polyethylene and polypropylene, and condensation systems such as polyester and polyamide. Examples thereof include non-woven fabrics whose main constituent fibers are fibers obtained by hydrophilizing synthetic fibers such as fibers with a hydrophilic oil agent.

As shown in FIG. 2, the absorber 4 includes a liquid-retaining absorbent core 40 and a core wrap sheet 41 that covers the skin-facing surface of the absorbent core 40. The absorbent core 40 has a substantially rectangular shape that is long in the vertical direction X in a plan view as shown in FIG. The core wrap sheet 41 is one continuous liquid-permeable sheet having a width of 2 times or more and 3 times or less the length of the lateral Y of the absorbent core 40, and as shown in FIG. 2, the absorbent core is It covers the entire skin-facing surface of the 40 and extends outward from both side edges along the vertical direction X of the absorbent core 40 in the lateral direction Y, and the extending portion is wound down below the absorbent core 40. The entire non-skin facing surface of the absorbent core 40 is covered. The core wrap sheet does not have to be such a single sheet. For example, one skin-side core wrap sheet that covers the skin-facing surface of the absorbent core 40 and the skin-side core wrap sheet are Separately, it may be configured to include one non-skin side core wrap sheet that covers the non-skin facing surface of the absorbent core 40.

The absorbent core 40 is a fiber aggregate obtained by stacking absorbent materials such as hydrophilic fibers and highly absorbent polymers, and can be produced according to a conventional method using a known fiber stacking device. Examples of the hydrophilic fibers that form the main component of the absorbent core 40 include those obtained by hydrophilizing hydrophobic fibers and those that are hydrophilic in themselves, and one of these fibers may be used alone or in combination of two or more. Can be used in combination. In particular, those that are hydrophilic and have water retention are preferable. As the latter hydrophilic fiber, natural fiber, cellulosic regenerated fiber or semi-synthetic fiber can be mentioned as a preferable example. As the hydrophilic fiber, pulp and rayon are particularly preferable, and pulp is more preferable. Examples of the pulp include wood pulp such as coniferous kraft pulp and broadleaf kraft pulp, as well as non-wood pulp such as cotton pulp and straw pulp, but the pulp is not particularly limited. Further, a crosslinked cellulose fiber obtained by cross-linking the inside and / or between the molecules of the cellulose fiber, or a bulky cellulose fiber obtained by mercerizing wood pulp may be used.

The absorbent core 40 may further contain a highly absorbent polymer in addition to the hydrophilic fibers. As the highly absorbent polymer contained in the absorbent core 40, a particulate polymer is generally used, but a fibrous polymer may also be used. When a particulate high-absorbent polymer is used, its 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 polyacrylic acid salt and the polymethacrylic acid salt, 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 above comonomers within a range that does not deteriorate the performance of the highly absorbent polymer can also be used. By containing the water-absorbent polymer in the absorbent core 40, 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 40 as needed.

A pair of sides of the absorbent body 5 on the skin-facing surface, that is, the skin-facing surface of the surface sheet 2 so as to overlap the left and right sides of the absorber 4 along the vertical direction X in a plan view. The sheets 6 and 6 are arranged over substantially the entire length of the absorbent body 5 in the vertical direction X. The pair of side sheets 6 and 6 are joined to the surface sheet 2 by known joining means at a joining line (not shown) extending in the vertical direction X, respectively.

In addition to the absorbent main body 5, the napkin 1 is a pair of wing portions 5W, 5W extending outward in the horizontal direction Y from both side portions along the vertical direction X of the excretory portion facing portion B1 in the absorbent main body 5. have.

In the absorbent article of the present invention, when the crotch portion B has a wing portion 5W as in the napkin 1 shown in FIG. 1, the vertical direction X corresponding to the longitudinal direction of the absorbent article (X in the figure). direction)
It means a region sandwiched between the root of one wing portion 5W along the vertical direction X and the root of the other wing portion 5W along the vertical direction X. The crotch portion B of the absorbent article having no wing portion is a lateral direction Y (corresponding to the width direction of the absorbent article) generated when the absorbent article is folded into a tri-fold individual packaging form. For the two bending lines (not shown) that cross in the Y direction in the figure, the area surrounded by the first bending line and the second bending line counting from the front end in the vertical direction X of the absorbent article is means.

The excretion portion facing portion B1 is a part of the crotch portion B of the absorbent body 5, and is a portion facing the excretion portion such as the vaginal opening in the wearer when the napkin 1 is worn. In FIG. 1, the rectangular region in the plan view surrounded by the dotted line in the lower crotch B is the excretion portion facing portion B1. The position and size of the excretion portion facing portion B1 vary depending on the type of the absorbent article, the body shape of the wearer, and the like, but the excretion portion facing portion B1 is usually located at the central portion of the crotch portion B in the lateral direction Y. For example, the discharge portion facing portion B1 of the absorbent article having the wing portion is at the boundary between the front portion A and the crotch portion B, that is, in the vertical direction X of the wing portion 5W, taking the napkin 1 having the wing portion 5W as an example. A pair of long sides with a length of 4 cm extending in the vertical direction X from the base on the front portion A side toward the rear portion C, and a length extending in the lateral direction Y and symmetrically formed with reference to the center of the lateral direction Y. It can be defined as a rectangular region in a plan view, which is defined by a pair of short sides of 2 cm in length.

Further, in addition to the absorbent main body 5, the napkin 1 further extends a pair of rear flap portions 5F, 5F extending outward in the horizontal direction Y from both side portions of the absorbent main body 5 along the vertical direction X of the rear portion C. And have. Such a sanitary napkin having a rear flap portion is suitable for long-term use at bedtime or the like, and is particularly useful as a sanitary napkin for night use. As the night napkin, a napkin having a total length of 30 cm or more in the vertical direction X is preferable, and a napkin having a total length of 35 cm or more is particularly preferable. However, the absorbent articles of the present invention include those having no rear flap portion.

As shown in FIG. 2, the side flap portion 5S projects greatly outward in the lateral direction Y at the crotch portion B, whereby a pair of wings are formed on both the left and right sides of the absorbent body 5 along the vertical direction X. Parts 5W and 5W are extended. The wing portion 5W has a substantially trapezoidal shape in which the lower base (the side longer than the upper base) is located on the side portion side of the absorbent main body 5 in a plan view as shown in FIG. 1, and the non-skin facing surface thereof. A wing portion adhesive portion (not shown) for fixing the wing portion 5W to clothing such as shorts is formed in the wing portion. The wing portion 5W is used by being folded back toward the non-skin facing surface (outer surface) side of the crotch portion of clothing such as shorts. Further, the side flap portions 5S also project greatly outward in the lateral direction Y in the rear portion C, whereby the pair of rear flap portions 5F, on both the left and right sides along the vertical direction X of the absorbent main body 5, The 5th floor is extended. The rear flap portion 5F was not folded back when it was fixed to the clothes, and was formed on the non-skin facing surface in a state where the non-skin facing surface was extended to the side of the widened absorbent body 5. It is fixed to the skin-facing surface (inner surface) of the clothes via the rear adhesive portion (not shown). Before its use, the wing adhesive portion and the rear adhesive portion are covered with a release sheet (not shown) made of a film, a non-woven fabric, paper or the like.

Grooves 7 and 8 are formed on the skin-facing surface of the absorbent body 5, that is, the skin-facing surface of the front surface sheet 2, in which the front surface sheet 2 and the absorber 4 are integrally recessed toward the back surface sheet 3. .. The groove 7 forms a closed ring that surrounds substantially the entire area of the excretion portion facing portion B1 and extends in the vertical direction X from the portion of the front portion A near the crotch portion B to the portion of the rear portion C near the crotch portion B. .. The groove 8 forms a closed annular shape surrounding the groove 7, and extends in the vertical direction X from the front portion A to the rear portion C. The grooves 7 and 8 are formed symmetrically with respect to the virtual center line VL that divides the napkin 1 in the horizontal direction Y and extends in the vertical direction X, respectively. The grooves 7 and 8 can be formed according to a conventional method by squeezing with or without heat, or by embossing such as ultrasonic embossing. In the grooves 7 and 8, the surface sheet 2 and the absorber 4 are integrated by heat fusion or the like. The main roles of the grooves 7 and 8 are to suppress the diffusion of the liquid in the plane direction of the absorber 4 and to prevent the absorber 4 from twisting. In the napkin 1, both the grooves 7 and 8 have a higher density than the portion of the absorber 4 excluding the high-density portion 10 described later.

As one of the main features of the napkin 1 of the present embodiment, 1) among the constituent members of the napkin 1 arranged at a position farther from the non-skin facing surface side surface layer portion of the surface sheet 2 and the wearer's skin. At least one of them contains a blood cell flocculant, and 2) a portion of the absorber 4 that is not located on the excretion portion facing portion B1 as compared with a portion of the absorber 4 that is located on the excretion portion facing portion B1. The point is that a high-density portion 10 having a high density is formed. The above 1) is mainly a characteristic part related to the improvement of the menstrual blood absorption performance of the napkin 1, and the above 2) is mainly to eliminate the inconvenience caused by the adoption of the above 1) and improve the wearing feeling of the napkin 1. This is the characteristic part involved. In the present invention, the "hemagglutinant" means an agent capable of agglutinating red blood cells in blood, and more specifically, it is a compound that meets the definition described later.

The above 1) is adopted to cover the skin-facing surface of the absorbent core 40 in the core wrap sheet 41, for example, a component that includes the non-skin-facing surface side surface layer portion of the surface sheet 2 and is farther from the wearer's skin. When a hemagglutinant is contained in the entire area of the portion (hereinafter, also referred to as a skin-side core wrap sheet), agglomerates of red blood cells are formed in the menstrual blood that has passed through the skin-side core wrap sheet due to the action of the hemagglutin. Therefore, when the highly absorbent polymer is contained in the absorbent core 40, the liquid absorption performance of the highly absorbent polymer is enhanced due to the suppression of absorption inhibition of the highly absorbent polymer by red blood cells. The menstrual blood absorption performance of the napkin 1 can be further improved. However, on the other hand, the skin-side core wrap sheet coated with the hemagglutination agent may lose its original flexibility due to film formation or the like caused by the hemagglutination agent, and may become hard as a whole. Here, when the skin-side core wrap sheet has the original flexibility, when an external force is applied to the napkin 1 due to the movement of the wearer's body during walking of the napkin 1 wearer or the like. In addition, since the napkin 1 is deformed into an appropriate form in response to the external force, a decrease in wearing feeling is suppressed. However, when the skin-side core wrap sheet is hard, the napkin 1 is subjected to such external force. The napkin 1 may be bent and deformed at an unintended part, which causes inconvenience. In particular, if the excretion portion facing portion, which is the most delicate portion of the wearer and is arranged to face the excretion portion, is broken or twisted while wearing the napkin, the skin feels poor.

Therefore, the present inventor has adopted the above 2). The aim of adopting 2) above is to positively control deformation at unintended sites when the skin-side core wrap sheet is hardened by the use of a hemagglutin while wearing the napkin 1. It is to be corrected by making a flexible shaft / deformation starting point. That is, as shown in FIG. 1, a high-density portion 10 having a higher density than a portion located in the excretion portion facing portion B1 of the absorber 4 is formed in a portion of the absorber 4 that is not located in the excretion portion facing portion B1. If the napkin 1 is subjected to an external force while being worn, the high-density portion 10 or its vicinity is likely to be the starting point of breakage. Therefore, the deformation of the napkin 1 during wearing is performed at a portion other than the excretion portion facing portion B1. It becomes an appropriate one starting from the breakage, and an unintended breakage at the excretion portion facing portion B1 is effectively prevented, leading to an improvement in wearing comfort.

As shown in FIGS. 1 and 2, the high-density portion 10 in the present embodiment is a recessed portion having a shape open to the surface sheet 2 side, and is a mortar-shaped or cylindrical portion squeezed from the surface sheet 2 side. It has a shape and is circular in a plan view. The high-density portion 10 is a portion that has been intentionally compressed, and can be formed according to a conventional method by squeezing with or without heat, or embossing such as ultrasonic embossing. In the high-density portion 10, the front surface sheet 2 and the absorber 4 are integrally recessed toward the back surface sheet 3 side. When the high-density portion 10 is formed by embossing with heat, the surface sheet 2 and the absorber 4 can be integrated in the high-density portion 10 by heat fusion or the like.

In the napkin 1 of the present embodiment, as shown in FIG. 1, a large number of high-density portions 10 are formed in a scattered pattern in the arrangement region of the absorber 4 (absorbable core 40) in a portion other than the excretion portion facing portion B1. Has been done. The excretion portion facing portion B1, that is, the uncompressed region is surrounded by the compressed region in which the high-density portion 10 is formed.

Further, in the napkin 1 of the present embodiment, as shown in FIG. 1, in the portion of the absorber 4 not located at the excretion portion facing portion B1, the density is lower than that of the high density portion 10 and the high density portion 10. The low-density portions are formed in a pattern that is alternately arranged in one direction. The "low density part" here is an uncompressed part that has not been intentionally compressed such as embossing, and can also be called a non-arranged part of the high density part, and has been intentionally compressed. The density is lower than that of the high density portion 10.

A typical pattern is a staggered pattern. In the napkin 1 of the present embodiment, the high-density portion 10 is formed in a staggered pattern. That is, in a portion of the absorber 4 that is not located on the excretion portion facing portion B1, a plurality of high-density portions 10 are arranged in a linear row at predetermined intervals in the vertical direction X. However, a plurality of rows are arranged in the horizontal direction Y, and in the vertical direction X, the high-density portions 10 are displaced from each other by the columns of the adjacent high-density portions 10.

Further, in the napkin 1 of the present embodiment, as shown in FIG. 1, the high-density portion 10 is formed symmetrically with respect to the virtual center line VL. With such a configuration, the flexibility of the napkin 1 as a whole is uniformly increased, deformation at an unintended part can be suppressed, and deformation of the napkin 1 while being worn can be controlled more appropriately to follow the body. The property is improved and leakage can be prevented.

Further, in the napkin 1 of the present embodiment, as shown in FIG. 1, a high-density portion in which the number of high-density portions 10 per unit area is relatively small in a portion not located at the excretion portion facing portion B1 of the absorber 4. There is a low distribution region 10L and a high density portion high distribution region 10H in which the number of high density portions 10 per unit area is relatively large. The high-density portion low distribution region 10L is arranged adjacent to the excretion portion facing portion B1 and is located at the crotch portion B, the portion of the front portion A near the crotch portion B, and the portion of the rear portion C near the crotch portion B. However, it surrounds the excretory portion facing portion B1. On the other hand, the high-density portion high distribution region 10H is arranged at a position farther from the excretion portion facing portion B1 than the high-density portion low distribution region 10L, and more specifically, the front portion A and the rear portion C are higher. It is arranged adjacent to the low density area 10L. As described above, the region relatively close to the excretion portion facing portion B1 has a small number per unit area of the high density portion 10, and the region relatively far from the excretion portion facing portion B1 is per unit area of the high density portion 10. When the number is large, the napkin 1 is preferentially broken at a portion other than the excretion portion facing portion B1, and the deformation of the napkin 1 while being worn can be controlled more appropriately.

Further, in the napkin 1 of the present embodiment, as shown in FIG. 1, the high-density portion 10 is formed before and after the vertical direction X with the excretion portion facing portion B1 interposed therebetween. With such a configuration, the breakage of the napkin 1 occurs preferentially at a portion other than the excretion portion facing portion B1, and it becomes possible to more appropriately control the deformation of the napkin 1 while wearing it.

From the viewpoint of ensuring that the action and effect of the high-density portion 10 is exhibited more reliably, it is preferable to set the dimensions and the like of the high-density portion 10 as follows.
The size of the area of the high-density portion 10 in a plan view is preferably 0.19 mm ² or more, more preferably 0.50 mm ² or more, and preferably 200 mm ² or less, still more preferably 150 mm ² or less. Specifically, the size of the high density portion 10 is preferably 0.19 mm ² or more 200 mm ² or less, more preferably 0.50 mm ² or more 150 mm ² or less.
When the high-density portion 10 has a circular shape in a plan view as shown in FIG. 3A, which will be described later, the diameter thereof is preferably 0.5 mm or more, more preferably 1.0 mm or more, and preferably 15. It is 0.0 mm or less, more preferably 12.0 mm or less. The diameter of the high-density portion 10 referred to here means the maximum length in a plan view when the high-density portion 10 is not circular in a plan view. For example, when the high-density portion 10 has an elliptical shape in a plan view, it is preferable that the length of the long axis of the ellipse is within the above range.
The shortest distance between the center points of the adjacent high-density portions 10 and 10 is preferably 0.5 mm or more, more preferably 1.0 mm or more, and preferably 15.0 mm or less, further preferably 12.0 mm or less. is there.
As shown in FIG. 3B, which will be described later, when a plurality of planar line-of-sight high-density portions 10A are arranged in a pattern that does not intersect with each other, the adjacent linear high-density portions 10A and 10A, respectively. It is preferable that the shortest distance between the center points of is within the above range. Further, as shown in FIGS. 3 (c) to 3 (e) described later, when a plurality of high-density portions 10B, 10C, and 10D having a plane line of sight are arranged in a pattern of intersecting or connecting with each other, Focusing on the intersections or connecting points of those high-density portions, it is preferable that the shortest distance between adjacent intersections or connecting points is within the above range.

The density of the distribution region of the high-density portion 10 not located in the excretion portion facing portion B1 is preferably 0.100 g / cm ³ or more, more preferably 0.150 g / cm ³ or more, and preferably 0.800 g / m ³ or more. Below, it is more preferably /0.750 g / m ³ or less.
The density of the non-arranged region of the low density portion, that is, the high density portion 10, is preferably 0.01 g / m ³ or more, more preferably 0.02 g / m ³ or more, and preferably 0.09 g / cm ³ or less, further. It is preferably 0.08 g / cm ³ or less.

The number of high-density portions 10 per unit area is preferably 1 or more, more preferably 2 or more, and preferably 30 when the unit area is the area of a square-shaped region having a side of 1 cm. The number is less than 25, more preferably 25 or less.
The ratio of the number of high-density portions 10 per unit area in the high-density portion low distribution region 10L to the number of high-density portions 10 per unit area in the high-density portion high distribution region 10H is preferably the former / latter. It is 0.03 or more, more preferably 0.05 or more, and preferably 0.70 or less, still more preferably 0.67 or less.

FIG. 3 illustrates a pattern of high-density portions applicable to the present invention. Each of the patterns shown in FIG. 3 is a pattern in which high-density portions (compressed portions and recessed portions) and low-density portions (non-compressed portions) are alternately arranged in one direction.
FIG. 3A is a pattern applied to the napkin 1 shown in FIGS. 1 and 2, and the high-density portion 10 having a circular shape in a plan view is formed in a staggered pattern. The entire shape of each high-density portion 10 in a plan view is compressed from the surface sheet 2 side to have a higher density than the periphery.
FIG. 3B is a pattern in which high-density portions 10A having a plan line-of-sight shape are formed in a staggered pattern, and each high-density portion 10A has a linear shape extending in the lateral direction Y.
FIG. 3C shows a pattern in which linear high-density portions 10B intersecting each other are formed in a grid pattern having rhombic eyes in a plan view, and the high-density portions 10B are in the vertical direction X and the horizontal direction Y. It is composed of two types of straight lines extending in directions intersecting both directions. In this case, a preferable range of the size or diameter of the high-density portion described above is applied to the sides of each lattice.
FIG. 3D shows a pattern in which linear high-density portions 10C intersecting each other are formed in a grid pattern having square or rectangular eyes in a plan view, and the high-density portion 10C extends in the vertical direction X. It is configured to include a straight line portion and a straight line portion extending in the lateral direction Y. In this case, a preferable range of the size or diameter of the high-density portion described above is applied to the sides of each quadrangle.
FIG. 3E is a so-called honeycomb pattern formed by connecting a plurality of linear or bent linear high-density portions 10D in a grid pattern having hexagonal eyes. In this case, a preferable range of the size or diameter of the high-density portion described above is applied to the sides of each hexagon.
In the patterns shown in FIGS. 3 (c) to 3 (e), all the portions corresponding to the grid are low-density portions (uncompressed portions).

As described above, in the absorbent article of the present invention, at least one of the non-skin facing surface side surface layer portion of the surface sheet and the constituent members of the absorbent article arranged at a position farther from the wearer's skin. Contains a hemagglutination agent. The "non-skin facing surface side surface layer portion of the surface sheet" as used herein means the surface sheet in the thickness direction from the non-skin facing surface of the surface sheet (the surface facing the core wrap sheet 41 in the napkin 1 shown in FIG. 2). It means a region within 20% of the maximum thickness of. Further, the "component of the absorbent article arranged at a position farther from the wearer's skin than the surface layer portion on the non-skin facing surface side of the surface sheet" is referred to as, for example, the napkin 1 shown in FIGS. 1 and 2. If there is, it is an absorber 4, that is, a core wrap sheet 41, an absorbent core 40, and a back surface sheet 3, and it is sufficient that at least one of these three constituent members 40, 41, 3 contains a hemagglutination agent. In the present invention, the reason why the hemagglutination agent is not contained in the portion of the surface sheet other than the surface layer portion on the non-skin facing surface side is to prevent the hemagglutination agent from adhering to the skin.

In the napkin 1 shown in FIGS. 1 and 2, a particularly suitable component as a component containing a hemagglutination agent is a core wrap sheet 41. The entire core wrap sheet 41 may contain a blood cell flocculant, but in the napkin 1, the position where the blood cell flocculant is particularly effectively utilized is the wearer's skin rather than the component containing the highly absorbent polymer. Considering this point, it is preferable to include a hemagglutination agent in the portion of the core wrap sheet 41 that covers the skin-facing surface of the absorbent core 40 (skin-side core wrap sheet).

Further, the position of the blood cell flocculant in the constituent members of the absorbent article such as the core wrap sheet is not particularly limited, and the blood cell flocculant may be uniformly contained in the entire constituent member, and may be selectively contained in a part of the constituent member. However, from the viewpoint of significantly improving the absorption performance of menstrual blood by utilizing the action and effect of the hemagglutination agent, at least hemagglutination in and around the excretory portion facing portion B1 where excretory fluid such as menstrual blood is concentrated. It is preferable to contain the agent, and it is particularly preferable to contain the agent in the entire area of the component member facing the skin, particularly in the entire component member. For example, in the case of the napkin 1, it is preferable that the entire portion of the core wrap sheet 41 that covers the skin-facing surface of the absorbent core 40 contains a hemagglutination agent.

As described above, from the viewpoint of improving the absorption performance of menstrual blood, it can be said that "a form in which the hemagglutination agent exists from the excretion part facing portion B1 to the portion other than the excretion part facing portion B1" is preferable. When the form is adopted, there is a concern that an unintended breakage may occur in the excretion portion facing portion B1 due to the fact that the constituent member to which the blood cell flocculant is applied, for example, the core wrap sheet 41 itself becomes hard. However, as described above, in the napkin 1 of the present embodiment, since the high-density portion 10 is formed in a portion other than the excretion portion facing portion B1 in a predetermined pattern, such a concern is dispelled.

The content of the hemagglutin in the constituent member (for example, core wrap sheet 41) containing the hemagglutin is preferably 0.1 g / m ² or more, more preferably 0.5 g / m ² or more, and more preferably 1. .5g / ^{m 2} or more, and preferably 25 g / ^{m 2} or less, more preferably 15 g / ^{m 2} or less, and more preferably not more than 10 g / ^{m 2.}

The method of containing the blood cell flocculant in at least one of the constituent members of the absorbent article is not particularly limited. For example, when the blood cell flocculant contains a cationic polymer described later, the blood cell flocculant may be used. The arrangement of the hemagglutination agent is to dissolve it in an appropriate solvent such as water, ethanol, or a mixed solution thereof, attach it to a desired portion of the constituent member as a hemagglutination agent solution, and then dry it to remove the solvent. It is preferable from the viewpoint of uniformly arranging the hemagglutination agent in the portion. Examples of the method for adhering the hemagglutination solution to the constituent members include dropping the hemagglutination agent solution onto a predetermined portion of the constituent member, spraying by spraying, dipping method, transfer method, die coating, gravure coating, and inkjet. Examples thereof include coating using a known liquid coating apparatus such as a method and a screen printing method. Further, the drying after the adhesion of the hemagglutination solution may be any of forced drying such as drying by heating, drying by reduced pressure, and drying by combining heating and reduced pressure, and natural drying may be used instead of these forced drying.

Hereinafter, the hemagglutination agent used in the present invention will be described. The hemagglutinant used in the present invention acts to aggregate red blood cells in blood so that the aggregates in which blood cells have aggregated and the plasma component are separated. Desirable hemagglutination agents include, for example, those having the following properties.
That is, when 1000 ppm of the measurement sample agent is added to the simulated blood, at least two or more erythrocytes aggregate to form agglomerates while the fluidity of the blood is maintained.
The simulated 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). In addition, the blood cell / plasma ratio of defibered horse blood (manufactured by Japan Biotest Research Institute Co., Ltd.) was prepared.

Here, the “state in which the fluidity of blood is maintained” means that 10 g of the pseudo blood to which 1000 ppm of the measurement sample agent is added is added to a screw tube bottle (Maruem product number “Screw tube No. 4”, inner diameter 14. It means a state in which 60% or more of the pseudo menstrual blood flows down within 20 seconds when the screw tube bottle containing the pseudo blood is placed in 5 mm, body diameter 27 mm, and total length 55 mm) and inverted 180 degrees.
Further, it is determined as follows whether or not "two or more erythrocytes aggregate to form an agglutinating mass". That is, the simulated blood to which 1000 ppm of the measurement sample agent was added was diluted 4000 times with physiological saline, and a laser diffraction / scattering type particle size distribution measuring device (HORIBA model number: LA-950V2, measurement condition: flow type cell). The average median diameter of the volume particle size measured at a temperature of 25 ° C. by the laser diffraction / scattering method using measurement, circulation speed 1, and no ultrasonic waves corresponds to the size of agglomerates in which two or more red blood cells have aggregated. When it is 10 μm or more, it is determined that “two or more erythrocytes aggregate to form an agglomerate”.

The hemagglutination agent used in the present invention is an agent that satisfies the above definition (can express erythrocyte aggregation) by a single compound or a combination thereof that meets the above definition, or by a combination of a plurality of compounds. That is, the hemagglutination agent is an agent limited to those having a hemagglutination action as defined above. Therefore, when the hemagglutination agent contains a third component that does not meet the above definition, it is expressed as a hemagglutination agent composition to distinguish it from the hemagglutination agent. 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.

In general, the absorption rate and absorption amount of water by a highly absorbent polymer differ depending on the type of water, and when comparing physiological saline and blood, blood has a slower absorption rate than physiological saline, and the amount of absorption is also high. Few. When the present inventor examined various reasons for this, the facts described below were found. Blood is roughly classified into a liquid component such as plasma and a non-liquid component such as red blood cells, and the component absorbed by a highly absorbent polymer is a liquid component such as plasma. As shown in FIG. 5A, when the menstrual blood 11 comes into contact with the highly absorbable polymer 14, only the liquid component 12 in the menstrual blood 11 is absorbed by the highly absorbable polymer 14, and the red blood cells which are the non-liquid component 13 are high. Not absorbed by the absorbent polymer 14. As the absorption of the liquid component 12 into the highly absorbent polymer 14 progresses, as shown in FIG. 5B, the non-liquid component 13 which is not absorbed by the highly absorbent polymer 14 accumulates on the surface of the highly absorbent polymer 14. A coating 15 is formed. Due to the formation of the coating film 15, liquid absorption inhibition of the highly absorbent polymer 14 occurs, and the absorption rate decreases. Further, due to the formation of the coating film 15, the swelling inhibition of the highly absorbent polymer 14 also occurs, and the absorption amount decreases.

As a result of various studies by the present inventor on means for preventing the occurrence of the phenomenon as shown in FIG. 5 (b) and preventing the deterioration of absorption performance, the components occupying most of the non-liquid components in menstrual blood. As shown in FIG. 4, it was found that it is effective to aggregate the erythrocytes to form agglomerates 16. By generating agglomerates 16 of erythrocytes, it becomes difficult to form a film of agglomerates 16, or even if agglomerates 16 form a film 15 as shown in FIG. 5 (b), a liquid is contained in the film 15. Since the space through which the component 12 can permeate remains, it becomes difficult for the absorption inhibition of the liquid component 12 to occur. As a result, the highly absorbent polymer 14 can sufficiently exhibit its original absorption performance. In order to further enhance the absorption performance, the larger the aggregate particle size of the erythrocytes is preferable, and the harder the aggregate hardness is, the more preferable. Here, the absorption performance is expressed on the basis of the absorption amount and the absorption rate. The amount of absorption can be expressed as the ratio of the volume of the highly absorbent polymer 14 before absorption to the volume of the highly absorbent polymer 14 after absorption, that is, the volume swelling ratio described later. Further, the absorption rate can be expressed as the slope of the volume swelling ratio of the highly absorbent polymer 14 with time.

Then, in the absorbable article of the present invention, the hemagglutination agent plays a role of generating erythrocyte aggregates in menstrual blood. According to the findings of the present inventor, a cationic polymer is useful as a hemagglutinant, for the following reasons. 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 layer, the erythrocyte membrane skeleton, and an upper layer, the lipid film. 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 agglomeration 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. According to the hemagglutination agent (cationic polymer), the above mechanism of action makes it possible to generate erythrocyte aggregates in menstrual blood.

As the hemagglutinant used in the present invention, a cationic polymer is suitable. Examples of the cationic polymer include cationized cellulose and cationized starch such as hydroxypropyltrimonium chloride starch. The hemagglutination agent used in the present invention may also include a quaternary ammonium salt homopolymer, a quaternary ammonium salt copolymer or a quaternary ammonium salt polycondensate as a 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 that generates 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 aggregating agent used in the present invention contains a quaternary ammonium salt homopolymer and / or a quaternary ammonium salt copolymer and / or a quaternary ammonium salt polycondensate as a cationic polymer, the blood cell aggregating agent. The agent 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 include. 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.

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 the sake of simplicity, 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".

From the viewpoint of effectively producing erythrocyte aggregates, the cationic polymer used as a hemagglutin agent preferably has a molecular weight of 2000 or more, more preferably 10,000 or more, and 150,000 or more. Is more preferable. 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 are sufficiently caused. In particular, when the molecular weight is 150,000 or more, the liquid absorption performance of the highly absorbent polymer is enhanced, which is more preferable. The upper limit of the molecular weight is preferably 30 million or less, more preferably 22 million or less, and even more preferably 10 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 10 million or less, more preferably 20 or more and 30 million or less, and further preferably 10,000 or more and 30 million or less. In addition, the cationic polymer dissolves well in menstrual blood, agglomerates of red blood cells are generated, the liquid absorption performance of the highly absorbable polymer contained in the absorbable core 40 is enhanced, and the menstrual blood absorption performance of the napkin 1 is enhanced. From the viewpoint of more reliably expressing the mechanism of increasing the blood content, the molecular weight of the cationic polymer is preferably 10,000 or more and 22 million or less, more preferably 10,000 or more and 22 million or less, and 30,000 or more and 10 million. The following is particularly preferable. 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. RI (refractive index) is used as the detector. 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. For 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 volume 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 performed 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 erythrocyte aggregates, 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-ray, 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 quantification 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 following formula 1.
Flow potential = (X + 0.190 ^* ) x 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 sialic acid present on the surface of erythrocytes. From this point of view, the present inventor 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 bond is a compound in which sialic acid can exist in a living body, and examples thereof include a compound in which sialic acid is bound to the end of a glycolipid such as a 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, Showa 5), "Organic Qualitative Analysis: Systematic. Pure Material Edition" by Akira Fujita (Kyoritsu Publishing, 1953), Akira Fujita Written by "Reorganized Chemical Experiments-Organic Chemistry" (Kawade Shobo, 1971),
"Systematic Organic Qualitative Analysis (Mixture)" by Akira Fujita and Masami Akatsuka (Kazama Shobo, 1974) and "New Edition Organic Conceptual Diagram Basics and Applications" by Yoshio Koda, Shiro Sato and Yoshio Homma (Sankyo Publishing, It is described in detail in 2008) and the like. In the physicochemical properties of substances, the degree of physical properties mainly due to Van Der Waals force is called "organic", and the degree of physical properties mainly due to electrical affinity is called "inorganic". It captures the physical properties of substances as 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 (trade name "Marcoat 106" manufactured by Japan Lubrizol Co., Ltd.), which is a cationic polymer used in Example 1 described later, an organic value of -C-x8 = 160 and an organic value of -C-x8 = 160. Ammo and NH4 salt × 1 = 400 inorganic value, Ring (non-aromatic single ring) × 1 = 10 inorganic value, -Cl × 1 = 40 organic value and 10 inorganic value Therefore, the total of the inorganic values is 400 + 10 + 10 = 420, and the total of the organic values 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, still more 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 values 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. By setting the organic value of the cationic polymer in this range, the cationic polymer is more successfully adsorbed on the red blood cells.

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. By setting the inorganic value of the cationic polymer in this range, the cationic polymer is more successfully adsorbed on the red blood cells.

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, 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 a number of 1.96 or more and 3.5 or less. Is more preferable. In particular, if the organic value and the inorganic value of the cationic polymer satisfy the above formula A, provided that the organic value and the inorganic value of the cationic polymer are within the above ranges, the cationic polymer is said to be cationic. The polymer is more likely to interact with the sialic acid conjugate and the cationic polymer is even more likely to be adsorbed on 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 powder or 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 bonded 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 (cationic 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 in the above range, that is, the quaternary ammonium salt. It is preferable because the steric hindrance when the polymer is adsorbed on the surface of the erythrocyte is reduced.

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 quaternized 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 takes 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. 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-methacryloxyethyldimethylethylammonium methylsulfate), poly (2-acrylicoxyethyldimethylamine quaternary salt), poly (2-acrylicoxyethyltrimethylamine quaternary salt), poly (2-acrylicoxy Ethyldimethylethylammonium ethylsulfate), poly (3-dimethylaminopropylacrylamide quaternary salt), dimethylaminoethyl polymethacrylate, 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 polydiallyldimethylammonium 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 are used. A copolymer obtained by copolymerizing with one or more bodies can be used. Further, in addition to or in place of the vinyl-based polymerizable monomer, another polymerizable monomer such as −SO ₂₋ can be used. As described above, the quaternary ammonium salt copolymer may be a binary copolymer or a ternary or higher copolymer.

In particular, the quaternary ammonium salt copolymer having a repeating unit represented by the above formula 1 and a 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. Among these polymerizable monomers, by using a cationically polymerizable monomer or a nonionic polymerizable monomer, charge cancellation with the quaternary ammonium moiety in the quaternary ammonium salt copolymer is performed. Can be effectively caused by the aggregation of red blood cells. Examples of cationically polymerizable monomers include vinylpyridine as a cyclic compound having a cation-bearing nitrogen atom under specific conditions, and a linear compound having a cation-bearing nitrogen atom in the main chain under specific conditions. Examples thereof include a condensed compound of dicyandiamide and diethylenetriamine. Examples of anionic polymerizable monomers 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, propylene glycol, ethylene glycol monomethacrylate, ethylene glycol monoacrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, methyl methacrylate and methyl. Examples thereof include acrylate, ethyl methacrylate, ethyl acrylate, propyl methacrylate, propyl acrylate, butyl methacrylate and butyl acrylate. As these cationically polymerizable monomer, anionic polymerizable monomer, or nonionic polymerizable monomer, one of them can be used, or any two or more kinds 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. The quaternary ammonium salt copolymer copolymerized by 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 agglutinated using a quaternary ammonium salt copolymer obtained from the copolymer, hard agglutination is likely to occur, and the highly absorbent polymer Absorption performance is less likely to be impaired. Examples of functional groups capable of hydrogen bonding include -OH, -NH ₂ , and -C.
HO, -COOH, -HF, -SH and the like can be mentioned. Examples of polymerizable monomers having a functional group capable of hydrogen bonding include hydroxyethyl methacrylate, vinyl alcohol, acrylamide, dimethyl acrylamide, ethylene glycol, propylene glycol, ethylene glycol monomethacrylate, and ethylene glycol monoacrylate. Examples thereof include hydroxyethyl methacrylate and hydroxyethyl 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 that 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 a functional group capable of having a hydrophobic interaction include methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, propyl methacrylate, propyl acrylate, butyl methacrylate, butyl acrylate, and styrene. Can be mentioned. In particular, methyl methacrylate, methyl acrylate, butyl methacrylate, butyl acrylate, etc., which have strong hydrophobic interactions 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 red blood cells. 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. 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 quaternary ammonium salt homopolymer and the quaternary ammonium salt copolymer described above 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.

In addition to the cationic polymer, the hemagglutination agent used in the present invention has a composition containing one or more other components such as a solvent, a plasticizer, a fragrance, an antibacterial / deodorant, and a skin care agent. It may be in the form of a substance (hemagglutination agent composition). 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, a plant extract, a citrus extract, etc. described in Japanese Patent No. 4776407 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, plant extracts, collagen, natural moisturizing ingredients, moisturizing agents, keratin softening agents, anti-inflammatory agents and the like described in Japanese Patent No. 4084278 can be used.

The proportion of the cationic polymer in the hemagglutination composition 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. By setting the proportion of the cationic polymer in the hemagglutination composition within this range, an effective amount of the cationic polymer can be imparted to the absorbent article.

Although the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be appropriately modified without departing from the spirit of the present invention. For example, the high-density portion according to the present invention is formed in a pattern in which high-density portions (compressed portions and recessed portions) and low-density portions (non-compressed portions) are alternately arranged in one direction as shown in FIG. The entire area of a predetermined region other than the portion facing the excretion portion may be a high-density portion. That is, for example, the entire area where the absorber (absorbent core) is arranged in a portion other than the portion facing the excretion portion may be a high-density portion. However, considering the wearing feeling of the absorbent article, it is preferable that the high-density portion is formed in a pattern in which a plurality of low-density portions are scattered, as shown in FIG.

Further, in the above-described embodiment, the absorber is composed of a fiber stack made of absorbent materials such as hydrophilic fibers and a highly absorbent polymer, but it may be composed of only an absorbent sheet. It may be configured to include both. The term "absorbent sheet" as used herein means a sheet-like absorbent structure containing an absorbent material, and is distinguished from a fiber stack made by stacking absorbent materials. Further, the excretion portion facing portion B1 is a so-called middle-high portion which is thicker than the peripheral portion, and the middle-high portion may protrude toward the wearer's skin side.

The present invention can be applied to all articles used for absorption of menstrual blood. Examples of such articles include, but are not limited to, panty liners, tampons and the like, in addition to sanitary napkins as in the embodiment.

〔Example〕
Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to such Examples. In addition, Example 1 is a reference example.

[Example 1]
A sanitary napkin having the same basic configuration as the sanitary napkin 1 shown in FIGS. 1 and 2 was prepared according to a conventional method. An air-through non-woven fabric having a basis weight of 30 g / m ² was used as the front sheet, and a non-moisture permeable polyethylene film having a basis weight of 25 g / m ² was used as the back sheet. As an absorbent core, a commercially available sanitary napkin (Kao Corporation 2015 "Lorier Skin Clean Guard 20.5 cm") is used to invalidate and decompose the hot melt adhesive that adheres each member using a dryer. The one taken out was used. The absorbent core had a basis weight of 295 g / m ² , the content of the highly absorbent polymer was 5.1% by mass, and Aquaric CA manufactured by Nippon Shokubai Co., Ltd. was used as the highly absorbent polymer. As a core wrap sheet for covering the absorbent core, a tissue paper having a basis weight of 16 g / m ² was used.
A 5% aqueous solution of a commercially available hemagglutin was applied to the entire area of the core wrap sheet covering the skin-facing surface of the absorbent core (skin-side core wrap sheet) and dried. The amount of the hemagglutin applied was 6.0 g / m ² in terms of solid content. As the hemagglutinant, trade name "Markault 100" (cationic polymer, weight average molecular weight: 150,000, IOB value 2.10, flow potential 7345 μeq / L) manufactured by Japan Lubrizol K.K. was used.
Pin embossing is applied from the front sheet side to the entire area of the absorber (absorbent core) placement area in the sanitary napkin other than the part facing the excretory part, and the absorber is recessed toward the back sheet side. A high-density portion having a circular shape in a plan view was formed in a predetermined pattern. Details such as the pattern of the high-density portion of Example 1 are as follows.
-Plane view shape of the high-density portion 10: Circular with a diameter of 2.0 mm-Pattern of the high-density portion 10: Symmetrical to a portion other than the excretion portion facing portion B1 in the arrangement region of the absorber 4 with respect to the virtual center line VL. Formed in a staggered pattern. The shortest distance between the center points of the high-density portion 10 is 5.0 mm.
-Density of the distribution region of the high-density portion 10 (the region where the absorber 4 is arranged and the region other than the excretion portion facing portion B1): 0.61 g / cm ³
-Density of low density part (non-arranged area of high density part 10, excretion part facing part B1): density 0.058 g / cm ³
-Number of high-density parts 10 per unit area (square-shaped area 1 cm square in plan view):
3.0 pieces / cm ²

[Example 2]
A sanitary napkin was prepared in the same manner as in Example 1 except that the high-density portion was formed in the same pattern as in FIG. 1, and this was used as a sample of Example 2. That is, in the second embodiment, a high-density portion low distribution region 10L in which high-density portions are distributed in a staggered pattern is formed in the crotch portion B, and regions located in front of and behind the vertical direction X with the excretion portion facing portion B1 in between. High-density portion high distribution region 10H in which high-density portions are distributed in a staggered pattern is formed in the front portion A and the rear portion C. Details such as the pattern of the high-density portion of Example 2 are as follows.
-Plane view shape of the high-density portion 10: Circular with a diameter of 2.0 mm-Pattern of the high-density portion 10: Symmetrical to a portion other than the excretion portion facing portion B1 in the arrangement region of the absorber 4 with respect to the virtual center line VL. Formed in a staggered pattern.
In the high-density portion high distribution region 10H, the shortest distance between the center points of the high-density portion 10 is 5.0 mm, the density of the region 10H is 0.61 g / cm ³ , and the number of the high-density portion 10 per unit area is 3.0.
Pieces / cm ² .
In the high-density portion low distribution region 10L, the shortest distance between the center points of the high-density portion 10 is 10 mm, the density of the region 10L is 0.058 g / cm ³ , and the number of high-density portions 10 per unit area is 1.0 /. cm ² .
The ratio of the number of high-density portions 10 to the high-density portion low distribution region 10L and the high-density portion high distribution region 10H per unit area is 0.33 as the former / the latter.

[Comparative Example 1]
A sanitary napkin was prepared in the same manner as in Example 1 except that the high-density portion was not formed, and this was used as a sample of Comparative Example 1.

[Comparative Example 2]
A sanitary napkin was prepared in the same manner as in Example 1 except that the hemagglutination agent was not applied to the core wrap sheet and no high-density portion was formed, and this was used as a sample of Comparative Example 2.

〔Evaluation test〕
For the sanitary napkins of each example and comparative example, the rigidity and the maximum dynamic absorption amount were evaluated by the following methods, respectively. The results are shown in Table 2 below. Rigidity is an index of the flexibility of sanitary napkins, and maximum dynamic absorption is an index of menstrual blood absorption of sanitary napkins.

<Rigidity evaluation method>
The rigidity of the sanitary napkin to be evaluated is determined according to the handle ometer method described in "JIS L 1096 Fabric Test Method for Woven Fabrics and Knits" (8.20. Compressibility and Compressibility E Method). Measured using. The test piece had a rectangular shape in a plan view of 65 mm × 80 mm, and the slit width was measured at 20 mm. The smaller the value of the pressure to be measured, the more flexible the test piece is, and if the test piece contains a hemagglutination agent, the hemagglutination agent is the test piece. It is shown that it is difficult to reduce the flexibility of.

<Dynamic maximum absorption amount>
The sanitary napkin to be evaluated 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 the pseudo blood was injected from the liquid excretion point (first time). Further, 3 g of the pseudo blood was injected 3 minutes after the completion of the first liquid injection (second time). Further, 3 minutes after the completion of the second liquid injection, 2 g of the pseudo blood was injected (third time). From the third time onward, the operation of injecting 2 g of the pseudo blood is repeated 3 minutes after the liquid injection, and the liquid injection operation is completed when the pseudo blood exudes from the wing portion of the sanitary napkin until that point. The total weight of the simulated blood injected into the blood was taken as the dynamic maximum absorption amount. The larger the dynamic maximum absorption amount, the better the menstrual blood absorption of the sanitary napkin.

According to the results shown in Table 2, the sanitary napkins of Examples 1 and 2 have a higher dynamic maximum absorption amount and excellent menstrual blood absorption as compared with the sanitary napkin of Comparative Example 2 containing no hemagglutination agent. It turns out. Further, it can be seen that the sanitary napkins of Examples 1 and 2 have lower rigidity, that is, are excellent in flexibility, as compared with the sanitary napkins of Comparative Example 1 in which the high-density portion is not formed. From these facts, by including the blood cell flocculant in the core wrap sheet, the menstrual blood absorbency of the absorbable article is improved, and the absorber is excreted in a portion not located opposite the excretion portion of the absorber. It can be seen that the flexibility of the absorbent article is improved by forming a high-density portion having a higher density than the portion located at the portion facing the portion.

1 Sanitary napkin (absorbent article)
2 Front sheet 3 Back sheet 4 Absorbent 40 Absorbent core 41 Core wrap sheet 5 Absorbent body 5F Rear flap 5S Side flap 5W Wing 6 Side sheet 7, 8 Grooves 10, 10A, 10B, 10C, 10D High density Part (compression part)
10H High-density part High distribution area 10L High-density part Low distribution area 11 Menstrual blood 12 Liquid component 13 Non-liquid component 14 Highly absorbent polymer 15 Coating 16 Aggregate A Front part B Crotch part B1 Excretion part Opposing part C Rear part

Claims (7)

It has a longitudinal direction corresponding to the anterior-posterior direction extending from the ventral side of the wearer to the dorsal side via the crotch portion and a lateral direction orthogonal to the longitudinal direction, and is arranged in the crotch portion at the time of wearing, and is arranged in the crotch portion in the excretion portion in the crotch portion. A crotch portion having an excretion portion facing portion arranged to face each other, a front portion arranged on the ventral side of the wearer from the crotch portion, and a rear portion arranged on the back side of the wearer from the crotch portion. An absorbent article that includes an absorber that is longitudinally capable of absorbing menstrual blood and a surface sheet that is arranged on the skin-facing surface side of the absorber and can come into contact with the wearer's skin when worn. There,
The hemagglutination agent is contained in at least one of the non-skin facing surface side surface layer portion of the surface sheet and the constituent members of the absorbent article arranged at a position farther from the wearer's skin.
The excretion portion facing portion is an uncompressed region, and is
A high-density portion that is intentionally compressed at a portion of the absorber that is not located opposite the excretion portion and has a higher density than a portion of the absorber that is located opposite the excretion portion. High-density part low distribution region where the number of high-density parts per unit area is relatively small, and high-density part high distribution where the number of high-density parts per unit area is relatively large. There is an area and
The high-density portion low distribution region is an absorbent article located in the crotch portion, the front portion near the crotch portion, and the rear portion near the crotch portion . In the portion of the absorber that is not located opposite the excretion portion, the high-density portion and the low-density portion having a lower density than the high-density portion are formed in a pattern in which the high-density portion is alternately arranged in one direction. The absorbent article according to claim 1. The absorbent article according to claim 2, wherein the pattern is a staggered pattern. The absorbent article according to claim 2 or 3, wherein the high-density portion is formed symmetrically with respect to a virtual center line extending in the vertical direction by dividing the absorbent article into two in the horizontal direction. The absorbent article according to any one of claims 1 to 4 , wherein the high-density portion is formed in the front-rear direction in the vertical direction with the excretion portion facing portion interposed therebetween. The absorbable article according to any one of claims 1 to 5 , wherein the blood cell flocculant has a weight average molecular weight of 20 or more and 30 million or less. The absorbable article according to any one of claims 1 to 6 , wherein the hemagglutination agent exists from the excretion portion facing portion to a portion other than the excretion portion facing portion.