Patent Publication Number: US-2021161729-A1

Title: Absorbent article

Description:
TECHNICAL FIELD 
     The present invention primarily relates to absorbent articles used in sanitary napkins, discharge sheets, incontinence pads, toiletries, and the like. 
     BACKGROUND ART 
     Conventionally, the absorbent article is known to include an absorbent article including a cotton pulp or the like between an impermeable backside sheet, such as a polyethylene sheet or a polyethylene sheet laminate nonwoven fabric, and a permeable surface sheet, such as a nonwoven fabric or a permeable plastic sheet. 
     In order to ensure the prevention of leakage of body fluid, it is effective to use a body fluid absorber having an excellent function to absorb and retain the body fluid. However, in order to maximize the absorption capacity of the body fluid provided by the absorber, it is particularly important to expand the diffusion region of the body fluid over a wide area of the absorbent article without any unevenness of the diffusion region of the body fluid in a specific part of the absorber. 
     Body fluid absorbed into the absorber enters the voids between the fibers, and diffuses between the fibers by capillary action. In this case, the body fluid that diffuses between fibers has the property of easily diffusing between fibers from large areas to small areas. That is, it is known that by forming the compressed portion of the absorber, the body fluid easily diffuses toward the compressed portion. 
     As an absorbent article forming such a compressed portion, for example, Patent Document  1  discloses an absorbent article with a pair of rear compressed portions separated from each other by at least compressing an absorbent core and a centerline passing through a center in a width direction, wherein the pair of rear compressed portions are formed along a front-back direction in the rear side region, wherein the pair of rear compressed portions are positioned behind the position where the hip flap becomes maximum in the width direction, and where the pair of rear compressed portions have a wide portion that increases the length in the width direction toward the rear side. 
     In addition, in the paragraph 0031 of Patent Document 2, an absorbent article with a front groove formed from a central portion having a forward convex shape and a pair of sides running in the central portion extending toward the rear is disclosed. 
     RELATED ART DOCUMENTS 
     Patent Document 
     Patent Document 1: Japanese Unexamined Patent Application Publication No. 2017-328 
     Patent Document 2: Japanese Unexamined Patent Publication No. 2007-275491 
     SUMMARY OF THE INVENTION 
     Problem to be Solved by the Invention 
     In the absorbent article described in Patent Document 1, a rear compressed portion inclined outward in the width direction with increasing distance from the front is provided. Because the rear compressed portion is provided separately from each other by a centerline passing through the center in the width direction of the absorbent article, the body fluid easily diffuses backward from the rear compressed portion through the gap between the pair of rear compressed portions, which may cause leakage from the end of the absorbent article. 
     On the other hand, in the absorbent article described in Patent Document 2, because the center in the width direction of the front groove projects forward and formed in a continuous linear shape substantially positioned on the longitudinal centerline of the absorbent article, the body fluid diffusing along the front groove is concentrated in the middle portion in the width direction of the front groove. As a result, the body fluid overflows at the pointed tip portion of the front groove and easily diffuses to the front side of the front groove, which may cause leakage from the end of the absorbent article. 
     Therefore, the main object of the present invention is to provide an absorbent article that prevents leakage from the end of the absorber by forming a compressed portion in a pattern that makes it easier to change the direction of diffusion of the body fluid that diffuses from the region corresponding to the body fluid discharging portion. 
     Means to Solve the Problem 
     To solve the above-mentioned problem, according to an embodiment of the present invention, there is provided an absorbent article including at least an absorbent body, including: 
     a leakproof compressed portion constituted of a depressed portion formed by depressing at least the absorbent body, configured to prevent a body fluid from leaking an end of the absorbent body by changing a diffusion direction of the body fluid diffusing from a region corresponding to a body fluid discharging portion of a wearer, and formed in a predetermined pattern outside the body fluid discharging portion corresponding region, 
     wherein the leakproof compressed portion includes a liquid induction portion that is arranged on both sides of a centerline directed from a proximal side to a distal side, that includes a portions whose separation distance on both sides of the centerline decreases toward the distal side from the proximal side, and that is configured to introduce the body fluid diffusing outward from the body fluid discharging portion corresponding region, a body fluid collection portion located on the centerline and more distant from the body fluid discharging portion corresponding region than the liquid induction portion and configured to collect the body fluid introduced by the liquid induction portion, and a liquid diffusion portion configured to diffuse the collected liquid onto both sides of the centerline. 
     Advantage of the Invention 
     As described in detail above, according to the present invention, by forming the compressed portion in a pattern that makes it easy to change the direction of diffusion of the body fluid diffusing from the region corresponding to the body fluid discharging portion, leakage from the end of the absorbent article can be prevented. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partially broken development view of a sanitary napkin  1  according to the present invention; 
         FIG. 2  is a cross-sectional view taken along a line II-II of  FIG. 1 ; 
         FIG. 3  is a cross-sectional view taken along a line of  FIG. 1 ; 
         FIG. 4  is a plan view of a leakproof compressed portion  11 ; 
         FIG. 5  is a plan view of a liquid induction portion according to a modification example; 
         FIG. 6  is a plan view illustrating a high compressed part  13   a  of a liquid collection portion; 
         FIG. 7  is a plan view of a leakproof compressed portion  11  according to a modification example; 
         FIG. 8  is a plan view of a leakproof compressed portion  11  according to a modification example; 
         FIG. 9  is a plan view of a sanitary napkin  1  according to a modification example; 
         FIG. 10  is a plan view (No.  1 ) of a sanitary napkin  1  according to another embodiment; 
         FIG. 11  is a plan view (No.  2 ) of a sanitary napkin  1  according to another embodiment; and 
         FIG. 12  is a plan view (No.  3 ) of a sanitary napkin  1  according to another embodiment. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     In the following, embodiments of the present invention are described below with reference to the accompanying drawings. 
     [Basic Structure of Sanitary Napkin  1 ] 
     As shown in  FIGS. 1 to 3 , the sanitary napkin  1  according to the present invention includes a liquid impermeable back sheet  2  made of a polyethylene sheet and the like, a liquid permeable top sheet  3  that quickly passes menstrual blood and a vaginal discharge (that are collectively referred to as a body fluid hereinafter), an absorbent body  4  made of cotton pulp or synthetic pulp or the like interposed between the both sheets  2  and  3 , and side non-woven fabrics  7  and  7  formed at both edge portions of the skin contact surface side throughout the approximately entire length in a lengthwise direction. Then, around the upper and lower edges of the absorbent body  4 , the back sheet  2  and the top sheet  3  are bonded to each other by bonding means such as an adhesive such as a hot melt, a heat seal, an ultrasonic seal, or the like, and the back sheet  2  and the side non-woven fabric  7  extending laterally from the absorbent body  4  are bonded to each other by bonding means such as an adhesive such as a hot melt, a heat seal, an ultrasonic seal, or the like, so that a pair of right and left wing flaps W and W are formed in the area corresponding to the body fluid discharging portion of the wearer (hereinafter, referred to as the “the body fluid discharging portion corresponding region H”). In the illustrated example, the absorbent body  4  is surrounded by an encapsulant sheet  5  made of crepe paper or non-woven fabric for maintaining the shape and improving the diffusivity of the absorbent body  4 , but the encapsulant sheet  5  is not required. In the illustrated example, a second sheet  6 , which is made of a non-woven, hydrophilic material having a substantially similar shape to the surface sheet  3 , is disposed adjacent to the non-skin side of the top sheet  3 . However, the second sheet  6  is not required. 
     The body fluid discharging portion corresponding region H is a region disposed facing the body fluid discharging portion (including a vaginal opening) of the wearer when the sanitary napkin  1  is worn. The range in the napkin lengthwise direction of the region H corresponding to the body fluid discharge portion may be made the range of the napkin lengthwise direction at the proximal ends of a wing-shaped flap W when the wing-shaped flap W is formed on both sides, as in the case of the present sanitary napkin  1 . When the wing-shaped flap W is not formed, the range of the napkin lengthwise direction may be made the range of the length of 70 to 90 mm in the napkin lengthwise direction from the position 60 to 80 mm behind the front edge of the sanitary napkin  1 . The width of the napkin may be within the spaced width of the compressed portions  10  and  10  for the body fluid discharging portion when the compressed portions  10  and  10  for the body fluid discharging portion are formed on both sides of the area corresponding to the body fluid discharging portion H, as in the case of the present sanitary napkin  1 . When the compressed portions  10  for the body fluid discharging portion are not formed, the width may be within the range of 30 to 50 mm centering the longitudinal centerline of the sanitary napkin  1 . 
     The structure of the sanitary napkin  1  will be further described below. As the back sheet  2 , a sheet material having at least water blocking properties, such as polyethylene, is used, and it is preferable that the sheet has moisture permeability from the viewpoint of preventing evaporation. As the water blocking and moisture permeable sheet material, a macroporous sheet is preferably used, which is obtained by melting and kneading an inorganic filler into an olefinic resin such as polyethylene or polypropylene to form a sheet, and then stretching the sheet in the uniaxial or biaxial direction. One or more adhesive layers (not shown) are formed along the lengthwise direction of the napkin on the non-skin side (outer surface) of the back sheet  2 , and the sanitary napkin  1  may be fixed to the underwear when it is attached to the body. The back sheet  2  may be a polylaminated non-woven fabric made of a plastic film and a non-woven fabric. 
     Next, as the top sheet  3 , a perforated or non-porous non-woven fabric or a porous plastic sheet is preferably used. As the material fibers constituting the non-woven fabric, in addition to synthetic fibers including olefinic type such as polyethylene or polypropylene, polyester type, and polyamide type and the like, regenerated fibers such as rayon and cupro, natural fibers such as cotton and the like, may be used. The non-woven fabric obtained by an appropriate processing method such as a thermal bond method, a span lace method, a spunbond method, a meltblown method, a needle punch method or the like may be used. Of these processing methods, an air-through-type thermal bond non-woven fabric having a large void between fibers (a non-woven fabric formed from heat-bonded fibers by a hot-air processor) is particularly preferred in the present sanitary napkin  1 . When a large number of holes is formed in the top sheet  3 , the body fluid is rapidly absorbed, and the top sheet  3  has excellent dry touch properties. The fibers of the non-woven fabric may be either long fibers or short fibers, preferably using short fibers to create a texture like a towel. Also, in order to facilitate an embossing process, it is preferable to use olefin fibers such as polyethylene or polypropylene having a relatively low melting point. Alternatively, core fibers having a high melting point and a sheath made of fibers having a low melting point may be preferably used as a core, a core-sheath type fiber, a side-by-side type fiber, or a split-type fiber composite fiber. 
     The absorbent body  4  interposed between the back sheet  2  and the top sheet  3  may be composed of, for example, pulp and superabsorbent polymer. The superabsorbent polymer can be incorporated into the pulp constituting the absorbent article, for example, as particulate powder. The pulp may be made of cellulosic fibers such as chemical pulp, dissolved pulp or the like obtained from wood, or artificial cellulosic fibers such as rayon, acetate or the like, and a coniferous pulp having longer fibers than a hardwood pulp is preferably used in terms of function and price. 
     Preferably, the present sanitary napkin  1  is a thin-type slim napkin having a low visibility of the absorbent body  4 . When the surface of the absorbent body  4  is lowered, the absorption capacity per unit area of the absorber  4  is reduced, and the body fluid easily diffuses in the plane direction. Therefore, in the slim napkin, the effect of the present invention of preventing leakage from the end of the absorbent body  4  can be fully exerted by changing the direction of diffusion of the body fluid. The basis weight of the pulp may be 50 to 300 g/m 2 , preferably 80 to 220 g/m 2 , and the basis weight of the superabsorbent polymer may be 30 to 180 g/m 2 , preferably 50 to 160 g/m 2 . The texture of these pulps and superabsorbent polymers need not be constant and may vary with the location of the absorbent article. For example, a high absorbency portion can be formed from pulp and superabsorbent polymer whose unit weight is made high in the area corresponding to the wearer&#39;s body fluid drain H. 
     A synthetic fiber may be mixed with the absorbent body  4 . The synthetic fiber may be a polyolefin such as polyethylene or polypropylene, a polyester such as polyethylene terephthalate or polybutylene terephthalate, a polyamide such as nylon, and a copolymer thereof, or may be a mixture of these two types. Alternatively, core fibers with high melting point and low melting point fiber sheaths may be used as core sheath fibers, side-by-side fibers, split fibers, and other composite fibers. In the case of hydrophobic fibers, it is preferable to use the synthetic fibers whose surface is treated with a hydrophilic agent so as to have an affinity for body fluids. 
     If necessary, the hydrophilic second sheet  6  disposed adjacent to the non-skin side of the top sheet  3  may have hydrophilic properties with respect to a body fluid. Specifically, a material having hydrophilicity itself may be used including regenerated fibers such as rayon or cupra, or natural fibers such as cotton. Otherwise, a fiber obtained by treating a surface of a synthetic fiber such as olefinic, polyester, or polyamide, such as polyethylene or polypropylene with a hydrophilic agent to provide hydrophilicity, may be used. In addition, a complex fiber such as a core-sheath type fiber including a core fiber having a high melting point and a sheath of fibers having a low melting point, a side-by-side type fiber, a split-type fiber or the like may be used. The second sheet  6  and the absorbent body  4  (the encapsulant sheet  5 ) are preferably bonded by hot melt adhesive or the like. By joining the second sheet  6  and the absorber  4 , the body fluid can be quickly transferred from the second sheet  6  to the absorbent body  4 . 
     The width dimension of the top sheet  3  is, in the illustrated example, slightly longer than the width of the absorbent body  4  as shown in the cross-sectional views in  FIGS. 2 and 3 , only covering the absorbent body  4 . A side non-woven fabric  7  that is different from the top sheet  3  is provided outside the top sheet  3 , and the side non-woven fabric  7  is configured by using a non-woven fabric material that is appropriately treated with water-repellent treatment or hydrophilic treatment depending on the purpose of preventing the menstrual blood or the virginal discharge from permeating the top sheet  3  or increasing the feel for the skin. 
     The side non-woven fabric  7  may be made of natural fibers, synthetic fibers, or regenerated fibers by any suitable processing method. As the side non-woven fabric, it is preferable to use a non-woven fabric having an increased basis weight in order to increase the concealment of the body fluid. Specifically, it is desirable to use a non-woven fabric made of a weight of 13 to 23 g/m 2 . In addition, a water-repellent non-woven fabric coated with silicon-based, paraffin-based, alkyl-chromic-based water repellent, or the like is preferably used to ensure prevention of permeation of body fluid. 
     As shown in  FIGS. 2 and 3 , the side non-woven fabric  7  is bonded with an adhesive such as hot melt over a range from a predetermined internal position to an outer edge of the back sheet  2 , and a flap portion in which the absorbent body  4  is not interposed is formed on both sides of the absorbent body  4  by the laminated sheet portion of the side non-woven fabric  7  and the back sheet  2 . The flap portion allows a pair of right and left wing flaps W and W to be formed longitudinally at a position on the side of the absorber corresponding to the body fluid discharging portion corresponding region H. An adhesive layer (not shown) is provided on the outer surfaces of the wing-shaped flaps W and W, respectively, so that the wing-shaped flaps W and W are folded back to the opposite side at the folding line RL position at the proximal end when mounted to the shorts, and are wound around the crotch portion of the shorts and secured thereto. Meanwhile, the inner side portion of the side non-woven fabric  7  is bonded to the absorbent body  4  side (the skin side of the top sheet  3 ) while being laminated to the skin side of the top sheet  3 . 
     &lt;Compressed Portion&gt; 
     In the present sanitary napkin  1 , at least a compressed portion formed by depressing the absorbent body  4  is formed in a predetermined pattern in a predetermined area. The compressed portion may be formed by depressing only the absorbent body  4  by compressing the absorbent body  4  from the skin side surface (the surface of the top sheet  3  side), or may integrally depress the encapsulant sheet  5  and the absorbent body  4  by compressing the encapsulant sheet  5  from the skin side surface of the encapsulant sheet  5  covering the skin side surface of the absorbent body  4 , or may depress the top sheet  3  integrally from the surface sheet  3  to the absorbent body  4  by compressing the top sheet  3  from the skin side surface while laminating the surface sheet  3  and the second sheet  6  as necessary on the skin side of the absorbent body  4 . Among them, in addition to the diffusion of the body fluid absorbed by the absorber  4 , in order to reduce the diffusion of the body fluid absorbed by the top sheet  3  and to prevent leakage of the body fluid flowing through the surface of the top sheet  3 , the aforementioned compression portion is preferably formed by the depression portion integrally depressed from the top sheet  3  to the absorbent body  4 . 
     In the sanitary napkin  1  shown in  FIG. 1 , as the aforementioned pressure portion, the compressed portion  10  for the body fluid discharging portion disposed along a lengthwise direction of the napkin on at least both sides of the body fluid discharging portion corresponding to the body fluid discharging portion H and blocking the discharged body fluid, and a pressure portion  11  for a leakproof purpose disposed outside the body fluid discharging portion corresponding to the body fluid discharging portion and preventing leakage from the end portion of the absorbent body  4  by changing the diffusion direction of the body fluid diffused from the body fluid discharging portion corresponding region H corresponding to the body fluid discharging portion. 
     The compressed portion for body fluid discharging portion  10  is provided to express resistant force against leg pressure or the like caused by the inner portion of the base of the leg acting in the width direction inward from both sides when being worn, to fit the area surrounded by the compressed portions for the body fluid discharging portion  10  and  10  to the body fluid discharging portion of the wearer, to block the body fluid absorbed by the absorbent body  4  or the body fluid flowing through the surface of the top sheet  3 , and to prevent the body fluid from diffusing outward from the compressed portion for the body fluid discharging portion  10 . 
     As the compressed portion for body fluid discharging portion  10 , a known form disposed at least on both sides of the body fluid discharging portion corresponding region H can be widely used. For example, in the illustrated example, it is formed by an elliptical shape surrounding the body fluid discharging portion corresponding region H. 
     Alternatively, it may be formed by a pair of arcuate lines separately disposed on both sides of the body fluid discharging corresponding region H, or it may be formed by a pattern with an approximately U-shape (approximately C-shape) in which the rear end or the front end is opened, that is, a symmetrical pattern with a convex or concave curve-shaped in the width direction outward. The compressed portion for body fluid discharging portion  10  is made of a continuous line pressed over the entire length in the illustrative example, but may be formed of an intermittent line in which the non-compressed portion is intermittently provided. 
     The compressed portion for body fluid discharging portion  10  may be configured by a compressed groove having a substantially uniform depth, but as shown in the drawings, it is preferable that the compressed portion  10  be composed of a low compressed portion and a high compressed portion having a greater depth than the low compressed portion. In the drawing, the black filled portion is the high compressed portion and the other portion is the low compressed portion. A plurality of the aforementioned high compressed portions is arranged at predetermined intervals. As the shape of the high compressed portion in a plan view, a well-known shape can be used, for example, a circular, semi-circular, elliptical, heart-shaped, star-shaped, or a combination of two or more of these. 
     Next, the above-mentioned leakproof compressed portion  11  will be described. The sanitary napkin  1  is characterized in that this leakproof compressed portion  11  is provided. The leakproof compressed portion  11  is used to prevent leakage from the end of the absorbent body  4  by changing the direction of diffusion of the body fluid that diffuses inside the absorbent body  4  from the body fluid discharging portion corresponding region H. 
     The leakproof compressed portion  11  is provided outside the body fluid discharging portion corresponding region H, and preferably outside the body fluid discharging portion corresponding region H spaced apart from the body fluid discharging portion  10 . Accordingly, the body fluid that diffuses outward beyond the compressed portion for body fluid discharging portion  10  can be prevented from diffusing toward the end of the absorbent body  4 , and the leakage prevention effect from the end of the absorbent body  4  can be improved. The distance (minimum separation length in a line) from the compressed portion for body fluid discharging portion  10  is not particularly limited, but it may be 5 to 30 mm, preferably 7 to 15 mm, because it is likely to flow continuously from the compressed portion for body fluid discharging portion  10  when the distance is too short and it is difficult to aggregate when the distance is too long due to the expansion of the diffusion area of the body fluid. On the other hand, the separation distance (the minimum distance in a straight line) between the leakproof compressed portion  11  and the edge of the absorbent body  4  is not particularly limited. However, it is preferable that the separation distance be not less than 10 mm in order to prevent leakage from the edge of the absorbent body  4 . Similar to the above-described compressed portion for body fluid discharging portion  10 , the foregoing leakproof compressed portion  11  may be configured by a compressed groove having a substantially uniform groove depth. However, as illustrated in the drawings, the foregoing leakproof compressed portion  11  preferably comprises a low compressed portion and a high compressed portion having a greater groove depth than the low compressed portion. 
     As a pattern in a plan view of the leakproof compressed portion  11 , as shown in  FIG. 4  in detail, includes a liquid induction portion  12  disposed on both sides of a centerline L from a proximal side to a distal side of a fluid discharging portion corresponding region H, and has portions arranged on both sides of the centerline L and whose distance decreases with increasing distance from the proximal side, a collection portion  13  located on the centerline L and on the distal side of the liquid induction portion  12 , and a liquid diffusion portion  14  extending from the collection portion  13  to both sides of the centerline L, thereby forming a generally ribbon shape (bowknot shape). 
     The liquid induction portion  12  has an action of directing a body fluid diffusing outward from the body fluid discharging portion corresponding region H to the L side of the central line. The body fluid diffusing from the body fluid discharging portion corresponding region H first reaches the liquid induction portion  12  among the leakproof compressed portion  11  and is guided along the liquid induction portion  12  toward the centerline L. 
     As shown in  FIG. 4 , the liquid induction portions  12  and  12  are arranged on both side of the centerline L, and preferably they are separated from each other by the centerline L between the liquid inductions  12  and  12 . As shown in  FIG. 4 , when the proximal side of the fluid discharging portion corresponding region H is positioned downward and the distal side is positioned upward, the liquid induction portions  12  and  12  on both sides are arranged in a substantially mountain shape without its apex (generally inverted V-shaped without the apex bonded). By positioning both sides of the centerline L apart from each other, the body fluid diffusing outward from the body fluid discharging portion corresponding region H is likely to flow through the separation portion provided in the central portion. The separation width A may be from 2 mm to 10 mm, preferably from 2 mm to 7 mm. When it is less than 2 mm, the body fluid is unlikely to pass through the space between the liquid induction portions  12  and  12  on both sides, and when it is larger than 10 mm, unless the collection portion  13  is formed in a large shape, the body fluid cannot be received by the collection portion  13 , and the body fluid easily flows outside the leakproof compressed portion  11 . 
     It is preferable that the liquid induction portion  12  be formed by a curve that expands to the side of the body fluid discharging portion corresponding region H in terms of facilitating the diffusion of the body fluid toward the centerline L, but this is not limited thereto. The liquid induction portion  12  may be formed by a curve or a straight line that expands to the distal side of the body fluid discharging portion corresponding region H. 
     The liquid induction portion  12  may have portions that decreases the distance from each other crossing the centerline L with increasing distance from the proximal side of the body fluid discharging portion corresponding region H at least on the side of the centerline L. The portion outside the above-mentioned portion may be formed so that the tip of the distal side (the tip on the distal side in the width direction) of the body fluid discharging portion corresponding region H is curved as shown in the drawings. The separation distance of the portions (the length in the direction perpendicular to the centerline L) that decreases the distance with increasing distance from the proximal side, may be set to any distance. However, in order to obtain the effect of sufficiently guiding the diffusing body fluid toward the centerline L along the liquid induction portion  12 , it is preferable that the length is not less than ½, preferably not less than ⅔, relative to the entire length of the liquid induction portion  12  (the length in the direction perpendicular to the centerline L). In addition, it is preferable that the length B from the centerline L to the tip of the liquid induction portion  12  be longer than the length C from the centerline L to the tip of the liquid diffusion portion  14  so that the body fluid diffusing from the proximal side to the distal side of the body fluid discharging portion corresponding end H does not directly reach the liquid diffusion portion  14  (B&gt;C). 
     Preferably, the liquid induction portion  12  is formed so as to gradually increase the average density of the fibers toward the centerline L. Accordingly, in the liquid induction portion  12 , the body fluid easily diffuses toward the centerline L due to the capillary action of the fiber, and the body fluid is easily concentrated in the collection portion  13 . The average density of fibers is an average value of density of fibers per unit area. In order to gradually increase the average density of fibers, because the average density of fibers can be increased by narrowing the space of the high compressed portion  12   a  having a relatively high fiber density, the liquid induction portion  12  may be formed of a low compressed portion and a high compressed portion  12   a  as shown in  FIG. 5 , and the space of the high compressed portion  12   a  may be gradually narrowed toward the centerline L. 
     The collection portion  13  has an action of receiving and collecting body fluid guided to the centerline L side by the liquid induction portions  12  and  12  on both sides. The collection portion  13  serves as a starting point for diffusing the liquid to the subsequent liquid diffusion portion  14 . 
     The collection portion  13  is positioned on the centerline L and on the distal side, more distant from the body fluid discharging portion corresponding region H than the centerline L-side tips of the liquid induction portion  12 . That is, the collection portion  13  is positioned adjacent to the tips of the liquid induction portions  12  and  12  so as to block the gap between the liquid induction portions  12  and  12  disposed on both sides of the centerline L. Therefore, a body fluid diffusing outward through a spaced gap between the liquid induction portions  12  and  12  is prevented from diffusing outward by the collection portion  13 . 
     The collection portion  13  may be positioned consecutively at the end of the liquid induction portion  12  on the centerline L side, or may be positioned spaced apart from the end of the liquid induction portion  12  as shown in  FIG. 4 . When the liquid is disposed continuously, the body fluid is easily transferred from the end of the liquid induction portion  12  to the collection portion  13 , and the subsequent diffusion to the liquid diffusion portion  14  is smoothly performed. On the other hand, when the fluid induction portion  12  and the collection portion  13  are disposed apart, because there is a relatively large air gap between the fibers of the non-compressed portion, the transfer of the body fluid from the liquid induction portion  12  to the collection portion  13  is slowed, and the body fluid is prevented from rapidly concentrating in the collection portion  13 , overflowing in the collection portion  13  and diffusing outward, thereby preventing leakage. The separation distance (minimum separation length in a straight line) between the collection portion  13  and the liquid induction portion  12  is not particularly limited, but preferably is about 0 to 5 mm. 
     The shape in a plan view of the collection portion  13  is preferably, but not particularly limited, substantially circular in order to receive body fluid and to disperse the collected body fluid. In the example shown in  FIG. 4 , a single high compressed portion  13   a  is disposed in the center of a generally circular low compressed portion. Thus, the direction of the diffusion of the body fluid is not limited, and the body fluid is dispersed almost evenly in any direction, thereby facilitating the diffusion of the bodily fluid. 
     The shape in a plan view of the high compressed portion  13   a  disposed in the collection portion  13  is not particularly limited, but it is preferable that the high compressed portion  13   a  be formed in a shape that is likely to cause liquid diffusion along the liquid diffusion portion  14 . Specifically, in addition to the circular shape shown in  FIG. 4 , the diamond shape may be formed as an X-shape or a diamond shape (in the example shown, a square shape) as shown in  FIG. 6 . If it is circular, it is likely to diffuse approximately evenly in all directions. When the X-shape is used, the diffusion of the body fluid in the direction along the centerline L is reduced, and the diffusion is easily made in the oblique direction. In the case of a square, such as a diamond, it is easier to direct the diffusion of body fluid in the oblique direction (toward the apex) in the shape of the high compressed portion  13   a  . It is preferable that the diamond shape is a square shape arranged so that one side thereof is inclined at an angle of 45 degrees so as to prevent the diffusion of the body fluid along the centerline L (from the proximal side to the distal side of the region corresponding to the body fluid discharging portion H) and to facilitate the diffusion of the body fluid toward both sides of the centerline L, that is, so that any diagonal of the diagonal shape is arranged along the centerline L. 
     The high compressed portion  13   a  disposed in the collection portion  13  may be formed in an area substantially equivalent to the high compressed portion disposed in other portions, but is preferably formed in an area larger than the high compressed portion disposed in other portions. Thus, the function as a barrier of the collection portion  13  can be strengthened, and it is possible to prevent the transfer of body fluid through the collection portion  13  from the proximal side to the distal side of the body fluid discharging portion corresponding region H. 
     The liquid diffusion portion  14  has an action of allowing body fluid collected in the collection portion  13  to diffuse toward both sides of the centerline L. Thus, the direction of the body fluid diffusing outward from the body fluid discharging portion corresponding region H (the direction of the body fluid diffusing outward along the aforementioned centerline L) can be dispersed in both sides of the centerline L, thereby preventing the diffusion of the body fluid toward the end of the absorbent body  4  and preventing leakage of the body fluid. 
     The liquid diffusion portion  14  preferably extends continuously from the liquid collection portion  13  for rapidly diffusing the body fluid collected in the liquid collection portion  13 . When the liquid diffusion portion  14  is connected to the liquid collection portion  13 , the low compressed portions are connected to each other. In addition, when the liquid diffusion portion  14  is disposed on both sides of the centerline L as described below, if at least two liquid diffusion portions  14  and  14  are disposed discontinuously, the liquid diffusion portions  14  may be disposed separated from each other in a discontinuous manner. 
     The direction in which the liquid diffusion portion  14  extends may not be parallel to the direction in which the centerline L extends. In order to prevent the body fluid from diffusing directly from the liquid induction portion  12  to the liquid diffusion portion  14  proximate to the liquid induction portion  12  while preventing the body fluid from diffusing toward the end of the absorbent body  4 , it is preferable that the direction in which the liquid diffusion portion  14  extends has a predetermined angle with respect to the centerline L. Specifically, the centerline L may be 30 degrees to 150 degrees, preferably 60 degrees to 120 degrees. 
     The liquid diffusion portion  14  may be arranged so as to extend as only a single portion from the liquid collection portion  13  to both sides of the centerline L, but it is preferable that the liquid diffusion portion  14  extends a plurality of times in a different direction. Thus, the body fluid collected in the collection portion  13  can quickly diffuse to both sides along the liquid diffusion portion  14 , and it is possible to prevent the body fluid from overflowing the collection portion  13  and diffusing toward the end of the absorbent body  4 . The number of the liquid diffusion portions  14  may be two as shown in  FIG. 4 , three as shown in  FIG. 7 , or four or more although it is not shown. 
     The shape in a plan view of the liquid diffusion portion  14  may be any shape, such as a straight line, a curve, a folded line, a wavy line, or the like. However, as shown in  FIGS. 4 and 7 , the curved shape is preferable so that the body fluid easily diffuses along the liquid diffusion portion  14 , and at the same time, when the liquid diffusion portions  14  and  14  are disposed on both sides of the centerline L, the area surrounded by the liquid diffusion portion  14  increases, so that more body fluid can be retained in this area. In particular, as shown in  FIGS. 4 and 7 , when a plurality of liquid diffusing portions  14 , . . . are disposed on both sides of a centerline L, it is preferable to form at least the liquid diffusion portion  14  disposed on the proximal side of the body fluid discharging portion corresponding region H by a curve that expands to the distal side of the body fluid discharging portion corresponding region H, and at least the liquid diffusion portion  14  disposed on the distal side of the body fluid discharging portion corresponding region H by a curve that expands to the distal side of the body fluid discharging portion corresponding region H. This increases an area of the region surrounded by the liquid diffusion portions  14 ,  14  and allows more body fluid to be retained in this area. 
     When a plurality of liquid diffusion portions  14 , . . . are disposed on both sides of the aforementioned centerline L, as shown in  FIGS. 4 and 7 , the tips (the outer portions in the width direction) of the liquid diffusion portions  14  and  14  disposed at the most proximal side and the distal side, respectively, of the body fluid discharging portion corresponding region H are preferably formed so as to gradually narrow the separation distances of each other with increasing distance from the liquid collection portion  13 . Accordingly, the body fluid diffused to the tip of the liquid diffusion portion  14  tends to be retained in a region surrounded by the liquid diffusion portion  14 , . . . and thus it is possible to prevent the liquid from diffusing outward. As a result, the leak prevention effect from the end of the absorbent body  4  can be increased. 
     As shown in  FIGS. 7 and 8 , at least two of the plurality of liquid diffusion portions  14 , . . . extending to both sides of the centerline L may be connected (coupled) at the tips. By connecting the tips with each other, the two liquid diffusion portions  14 ,  14  are formed in a closed loop shape, making it easier to retain body fluid in the loop. 
     In order to facilitate the retention of the body fluid in the region surrounded by the plurality of liquid diffusing portions  14 , , the whole or a part of the region surrounded by the of liquid diffusing portions  14 , all of the region (the diagonal region in the figure) in the illustrated example, may include compressed regions  15 , as shown in  FIG. 8 . The compressed region  15  is a depressed region formed with a depth approximately equal to or shallower than that of the low compressed portion of the liquid diffusion portion  14 , wherein at least the absorbent body  4 , preferably the top sheet  3  and the absorbent body  4 , are integrally depressed from the surface of the top sheet  3 . Thus, the inter-fiber space of the compressed region  15  becomes smaller than the inter-fiber space of the region outside the liquid diffusion portion  14 , and the body fluid easily accumulates in the compressed region  15  due to the capillary action. 
     In the example shown in  FIG. 1 , a pattern in a plan view is formed substantially symmetrically with respect to the centerline L, and the centerline L is provided at a position substantially coincident with a longitudinal centerline passing through the width-direction-center portion of the sanitary napkin  1  on the front side and the rear side of the body fluid discharging corresponding region H, respectively. Thus, it is possible to prevent so-called front leakage and rear leakage, in which the body fluid diffusing forward and backward from the the body fluid discharging portion corresponding region H leaks from the front and rear ends of the absorbent body  4 . When the pattern in a plan view of the foregoing leakproof compressed portion  11  is formed symmetrically with respect to the centerline L, the effect is noticeable in a position where the body position of the wearer is almost symmetrical, such as standing, sitting, or supine position. 
     The leakproof compressed portion  11  is provided only on one side of the front side and the rear side of the body fluid discharging portion corresponding region H, but not on the other side. The leakproof compressed portion  11  may be arranged in series or in parallel in each region. In addition, it may be disposed on both sides or in the diagonal direction of the body fluid discharging corresponding region H. 
     Meanwhile, the leakproof compressed portion  11  may be formed so that the pattern in a plan view is asymmetric to the centerline L as shown in  FIG. 9 . In this case, it is preferable that the arrangement of the leakproof compressed portion  11  be disposed at the diagonal position of the body fluid discharging portion corresponding region H (a position where the centerline L of the leakproof compressed portion  11  does not overlap the longitudinal center line extending longitudinally in the width direction of the central portion of the sanitary napkin  1 , and is inclined at a predetermined angle to the longitudinal center line), as shown in the drawing example. Thus, the portion disposed on the side of the sanitary napkin  1  from the centerline L can have different functions on both sides of the centerline L, such that the portion disposed on the lateral side of the sanitary napkin  1  from the centerline L is formed in a pattern suitable for capturing body fluid diffusing in the width direction of the sanitary napkin  1  from the body fluid discharging portion corresponding region H, and the portion disposed on the central side of the sanitary napkin  1  from the centerline L is formed in a pattern suitable for capturing body fluid diffusing in the longitudinal direction of the sanitary napkin  1  from the body fluid discharging portion corresponding region corresponding region H. For example, in the example shown in  FIG. 9 , the separation distance between the liquid induction portion  12  and the liquid diffusion portion  14  is increased in the liquid diffusion portion  14  from the centerline L in the lateral portion of the sanitary napkin  1  to the central portion thereof so as to prevent the body fluid passing through the liquid induction portion  12  from moving to the liquid diffusion portion  14 . Thus, because the body fluid flowing laterally to the body fluid discharging portion corresponding region H is reliably collected in the collection portion  13  by the liquid induction portion  12 , and then dispersed in the plurality of liquid diffusion portions  14 , . . . , the amount of the body fluid flowing laterally to the absorbent body  4  can be reliably reduced. When formed in a laterally asymmetric pattern, the ability to inhibit fluid diffusion can be enhanced when the wearer is more likely to diffuse laterally in a particular position, such as in a lateral decubitus position. Although not shown, the amount of the body fluid diffusing to the edge of the absorbent body  4  may be further reduced by increasing the relative number of the diffusion portions  14  disposed at the central side of the sanitary napkin  1  from the centerline L. 
     In the sanitary napkin  1  having the above-described configuration, in the leakproof compressed portion  11 , the body fluid that diffuses outward from the body fluid discharging portion corresponding region H is collected in the fluid collection portion  13  by the liquid induction portion  12 , and then caused to diffuse toward both sides of the centerline L along the liquid diffusion portion  14 , Accordingly, by providing the leakproof compressed portion  11 , because the direction of the diffusion of the body fluid diffused from the body fluid discharging portion corresponding region H can be controlled in a direction different from the direction (the direction in which the centerline L extends) toward the end of the absorbent body  4 , the leakage from the end of the absorbent body  4  can be prevented. 
     Further, as shown in  FIG. 4 , even when the liquid induction portion  12  cannot introduce the body fluid to the collection portion  13 , and when the body fluid diffuses across the liquid induction portion  12 , a plurality of liquid diffusion portions  14 , are disposed at the distal side of the body fluid discharging portion corresponding region H. Therefore, the liquid diffusion portions  14 , act as a levee to block the diffusion of the body fluid, and it is possible to prevent the body fluid from diffusing from the leakproof compressed portion  11  to the distal side of the body fluid discharging portion corresponding region H. 
     Examples of Other Embodiments 
     In the above-described embodiment, a so-called daytime sanitary napkin  1 , in which a body fluid discharging portion corresponding region H is provided in a substantially central portion of a sanitary napkin  1 , is illustrated. As shown in  FIGS. 10 to 12 , a so-called nighttime sanitary napkin  1  is possible. The nighttime sanitary napkin  1  is constituted of a crotch region below the hip including a body fluid discharge portion corresponding portion where the wing-like flaps W and W are provided on both edges, a front side region below the hip up to a front end of a sanitary napkin  1  in which a lower abdomen of a wearer is covered at the time of wearing, and a rear side region below the hip up to a rear end of a sanitary napkin  1  in which a region covers the buttock of a wearer at the time of wearing, wherein the rear side region is formed longer than the front side region and, a pair of left and right hip-hold flaps W B  and W B  that project outward in the width direction, are formed on the both edges of the rear side region. 
       FIG. 10 , a single leakproof compressed portion  11  is provided only on the front side of the body fluid discharging portion corresponding region H, that is, in the front side region, but not in the rear side region. By providing the leakproof compressed portion  11  on the front side of the body fluid discharging portion corresponding region H, it is possible to prevent the body fluid from diffusing in the lengthwise direction of the napkin in the front side region that is relatively narrow compared to the rear side region, and leakage from the front end can be prevented. 
     In  FIGS. 11 and 12 , a single leakproof compressed portion  11  is provided on each of a front side and a rear side of the fluid discharging portion corresponding region H, that is, on the crotch region from below the hips to the front side, and on the rear side. In particular, it is preferable that the leakproof compressed portion  11  provided in the rear side region be disposed so as to overlap the maximum width position of the hip-hold flap W B  (the position where the hip-hold flap W B  protrudes outwardly in the width direction and the position indicated by the single dotted line in the drawing). Thus, even when part of the body fluid diffusing in the longitudinal direction diffuses in the width direction by the leakproof compressed portion  11 , because the hip-hold flap W B  extends in the width direction, the leakage from the edge in the width direction can be prevented. When the leakproof compressed portion  11  provided in the rear side region overlaps the maximum width position of the hip-hold flap W B , the leakproof compressed portion  11  may be disposed so that the collection portion  13  of the leakproof compressed portion  11  overlaps the maximum width position as shown in  FIG. 11 , or the leakproof compressed portion  11  may be disposed so that the liquid induction portion  12  of the leakproof compressed portion  11  overlaps the maximum width position as shown in  FIG. 12 . In the former case ( 1 ), even if the body fluid collected in the collection portion  13  diffuses in the width direction through the liquid diffusion portion  14 , the maximum width position of the hip-hold flap W B  allows for more reliable prevention of leakage from the edge in the width direction. In the latter case ( 2 ), even when the body fluid diffuses outward through the liquid induction portion  12 , the maximum width position of the hip-hold flap WB allows for more reliable prevention of leakage from the edge in the width direction. 
     The leakproof compression portion  11  may be provided only on the rear side of the body fluid discharging portion corresponding portion H, that is, on the rear side of the body fluid discharging portion, and may not be provided in the crotch region below the hips and the front side region. In  FIGS. 10 to 12 , the high compressed portion of the compressed portion composed of the low compressed portion and the high compressed portion is illustrated by a black collapsed portion, and the outer edge of the low compressed portion is not illustrated. 
     Hereinafter, preferred embodiments of the present invention will be described. 
     (Appendix 1) 
     In the embodiment described in Appendix 1, an absorbent article including at least an absorbent body includes a leakproof compressed portion constituted of a depressed portion formed by depressing at least the absorbent body, configured to prevent a body fluid from leaking an end of the absorbent body by changing a diffusion direction of the body fluid diffusing from a region corresponding to a body fluid discharging portion of a wearer, and formed in a predetermined pattern outside the body fluid discharging portion corresponding region, wherein the leakproof compressed portion includes a liquid induction portion that is arranged on both sides of a centerline directed from a proximal side to a distal side, that includes a portions whose separation distance on both sides of the centerline decreases toward the distal side from the proximal side, and that is configured to introduce the body fluid diffusing outward from the body fluid discharging portion corresponding region, a body fluid collection portion located on the centerline and more distant from the body fluid discharging portion corresponding region than the liquid induction portion and configured to collect the body fluid introduced by the liquid induction portion, and a liquid diffusion portion configured to diffuse the collected liquid onto both sides of the centerline. 
     In the embodiment described in Appendix 1, a leakproof compressed portion is formed outside a region corresponding to a body fluid discharging portion (the body fluid discharging portion corresponding region) of a wearer in a predetermined pattern in order to prevent leakage from the end of the absorbent article by changing the direction of diffusion of body fluid diffusing outward from the body fluid discharging portion corresponding region of the wearer. The pattern of the leakproof compressed portion includes a liquid induction portion disposed on both sides of the centerline from the proximal side to the distal side of the body fluid discharging portion corresponding region and having a portion in which the central line is interposed therebetween in a distance from the proximal side to the distal side of the body fluid discharging portion corresponding region, a collection portion located on the centerline and the distal side of the body fluid discharging portion corresponding region, and a liquid diffusion portion extending from the collection portion to both sides of the centerline. In the leakproof compressed portion formed in such a pattern, a body fluid that diffuses outward from the region corresponding to the fluid drain portion is guided toward the centerline of the leakproof compressed portion by the fluid induction portion, and after the body fluid induced by the fluid induction portion is concentrated in the fluid collection portion, the collected body fluid is diffused toward both sides of the centerline by the fluid diffusion portion. Accordingly, by providing the leakproof compressed portion in such a pattern, the direction of the diffusion of the body fluid diffused from the body fluid discharging portion corresponding region is changed in a direction different from the direction toward the end of the absorbent body, that is, the direction in which the centerline extends, so that the leakage from the end of the absorbent body can be prevented. In addition, even in the case where there is a body fluid that diffuses distally from the body fluid discharging portion corresponding region through which the liquid induction portion cannot be guided to the collection portion, because the liquid diffusion portion is disposed at the distal portion, the liquid diffusion portion acts as a levee and securely blocks the body fluid, thereby preventing the body fluid from diffusing toward the end portion of the absorbent body. 
     (Appendix 2) 
     In the embodiment described in Appendix 2, the absorbent article according to appendix 1 is provided, wherein the leakproof compressed portion is disposed at least on one of the front side and the rear sides or on both sides of the body fluid discharging portion corresponding region. 
     In the embodiment described in Appendix 2, leakage from the front and rear sides of the absorbent body can be prevented by placing the leakproof compressed portion at least on one or both of the front and rear sides of the body fluid discharging portion corresponding region. 
     (Appendix 3) 
     In the embodiment according to Appendix 3, an absorbent article according to Appendix 1 or 2, wherein the liquid induction portions are spaced apart from each other on both sides of the centerline. 
     In the embodiment described in Appendix 3, the fluid induction portion is disposed on both sides of the centerline, which causes the body fluid diffusing from the body fluid discharging portion corresponding region to the outside to easily diffuse directly into the fluid collection portion through the space between the liquid induction portions on both sides. 
     (Appendix 4) 
     According to the embodiment described in Appendix 4, an absorbent article according to any one of Appendices 1 to 3, wherein the liquid induction portion and the liquid collection portion are arranged consecutively or spaced apart from each other. 
     In the embodiment described in Appendix 4, when the liquid induction portion and the liquid collection portion are arranged continuously, the body fluid is easily transferred from the liquid induction portion to the liquid collection portion. On the other hand, when these compressed portions are arranged spaced apart from each other, there is a non-compressed portion having a large air gap between the liquid induction portion and the liquid collection portion. Therefore, the transfer of body fluid from the liquid induction portion to the fluid collection portion is slowed, and it is possible to prevent the rapid concentration of body fluid in the fluid collection portion. 
     (Appendix 5) 
     In the embodiment according to Appendix 5, an absorbent article according to any one of Appendices 1 to 4, wherein the liquid induction portion is formed so as to gradually increase an average density of fibers toward the centerline. In the embodiment described in Appendix 5, the liquid induction portion is formed so as to gradually increase the average density of the fibers toward the centerline, so that the fluid flow toward the centerline is likely to occur due to the capillary action of the fibers. In order to gradually increase the average density of the fibers toward the centerline, the liquid induction portion may comprise a low compressed portion and a high compressed portion, and the space between the high compressed portion may be gradually narrowed toward the centerline. 
     (Appendix 6) 
     In the embodiment according to Appendix 6, an absorbent article according to any one of Appendices 1 to 5, wherein the liquid collection portion has a low compressed portion and a high compressed portion, and wherein the high compressed portion is formed into a circular shape, an X shape, or a diamond shape in a plan view. 
     In the embodiment according to Appendix 6, the high compressed portion is formed in a predetermined shape in a plan view in order to disperse the body fluid concentrated in the collection portion and disperse the body fluid in the liquid diffusion portion for easy diffusion. 
     (Appendix 7) 
     In the embodiment according to Appendix  7 , an absorbent article according to any one of Appendices 1 to 6, wherein the liquid diffusion portion extends from the liquid collection portion on both sides of the centerline in a different direction. 
     In the embodiment described in Appendix 7, when the liquid diffusion portion is formed so as to extend in a different direction from the liquid collection portion to both sides of the centerline, the body fluid collected in the fluid collection portion easily diffuses in a plurality of directions to both sides of the centerline, and the body fluid easily diffuses along the liquid diffusion portion. 
     (Appendix 8) 
     In the embodiment according to Appendix 8, the absorbent article according to Appendix 7, wherein at least two of the plurality of liquid diffusion portions extending across the centerline are connected at a tip thereof. 
     In the embodiment described in Appendix 8, when at least two of the plurality of liquid diffusion portions extending to both sides of the centerline are connected to each other at the front end, the body fluid easily diffuses into the two or more liquid diffusing portions formed in a loop shape, and thus the diffusion of the body fluid to the outside is reduced. 
     (Appendix 9) 
     In the embodiment described in Appendix 9, an absorbent article according to any one of Appendices 1 to 8, wherein the leakproof compressed portion is formed in a right-left symmetrical or right-left asymmetric relation to the centerline. 
     In the embodiment described in Appendix 9, when the leakproof compression portion is formed symmetrically with respect to the centerline, the inhibition effect of the body fluid diffusion can be enhanced in a position such as a standing position, a sitting position, or a supine position, and when the leakproof compression portion is formed asymmetrically with respect to both sides, the inhibition effect of the body fluid diffusion can be enhanced in a specific position such as a lateral decubitus position. 
     The present application is based upon and claims priority of Japanese Patent Application No. 2018-048764 filed on Mar. 16, 2018, with Japanese Patent Office, the entire contents of which are hereby incorporated herein by reference. 
     DESCRIPTION OF REFERENCE SYMBOLS 
       1  sanitary napkin 
       2  back sheet 
       3  top sheet 
       4  absorbent body 
       5  encapsulating sheet 
       6  second sheet 
       7  side non-woven fabric 
       10  body fluid discharging compressed portion 
       11  leakproof compressed portion 
       12  liquid induction portion 
       13  liquid collection portion 
       14  liquid diffusion portion 
       15  compressed region 
     H body fluid discharging portion corresponding region 
     L centerline