JP6189143B2 - Absorbent articles - Google Patents

Description

  The present invention relates to absorbent articles such as disposable diapers and sanitary napkins.

  Various techniques are known in which an absorbent body of an absorbent article is composed of pulp fibers and superabsorbent polymer particles, and the superabsorbent polymer particles are unevenly distributed in the thickness direction of the absorbent body. For example, in Patent Document 1, the density of the high absorption material in the first half portion including the first main plane side of the absorber is higher than the density of the high absorption material in the second half portion including the opposing second main surface. It is described that the height is also increased. The first main plane faces the skin contact surface side of the absorbent article.

  Patent Document 2 describes an absorbent article in which a superabsorbent polymer is mixed inside an absorber and a part or all of the superabsorbent polymer is unevenly distributed on the surface layer side. . In addition, this document describes that the absorbent body in which the superabsorbent polymer is unevenly distributed is used in combination with a topsheet provided with uneven embossing.

  By the way, in order to efficiently absorb the liquid in the entire area of the absorber, various devices for diffusing the liquid in the surface direction of the absorber and effectively using the absorption area have been proposed. For example, a technique is known in which a sublayer sheet that easily diffuses liquid in the surface direction is disposed on the skin contact surface side of the absorbent body. Also known is a technique of diffusing the liquid throughout the absorber by forming grooves in the absorber or compressing the absorber. However, on the other hand, if the liquid diffuses widely over the entire area of the absorber, there are concerns about an increase in the area where the skin comes into contact with the liquid, and concerns about an increase in the humidity of the space between the absorbent article and the skin when worn. There is. In each of the above-mentioned patent documents, no examination has been made on means for eliminating the disadvantages caused by enhancing the diffusion while enhancing the diffusion of the liquid in the surface direction of the absorber.

JP-A-6-205806 JP 2007-117727 A

  Therefore, the subject of this invention is providing the absorbent article which can eliminate the fault which the prior art mentioned above has.

The present invention comprises a top sheet positioned on the side close to the wearer's skin, a back sheet positioned on the side far from the wearer's skin, and an absorber positioned between the top sheet and the back sheet. A vertically long absorbent article having a direction and a width direction perpendicular thereto,
The absorbent body has an absorbent core and a core wrap sheet that covers the absorbent core,
The absorbent core is a first surface in which pulp fibers and a superabsorbent polymer are mixed, the absorption rate of the superabsorbent polymer is not less than 30 seconds and not more than 150 seconds, and the ratio of the superabsorbent polymer is high. And a second surface located on the opposite side of the first surface and having a high ratio of the pulp fibers,
The absorbent core is arranged such that the first surface is located on the skin contact surface side and the second surface is located on the non-skin contact surface side,
The surface sheet has a concavo-convex structure at least on the side facing the absorber, and a space resulting from the concavo-convex structure is formed between the surface sheet and the absorber.
In the absorbent body, an absorbent article is provided in which the first surface of the absorbent core and the core wrap sheet are intermittently joined in the width direction in a plurality of adhesive regions extending along the longitudinal direction. It is.

  According to the absorbent article of the present invention, the diffusion of the liquid on the skin contact surface side can be suppressed, and the liquid can be largely diffused on the non-skin contact surface side. Therefore, according to the absorbent article of the present invention, liquid transfer to the skin and liquid return are reduced, and an increase in humidity in the space between the absorbent article and the skin is reduced. Furthermore, heat and water vapor can be efficiently dissipated to the outside on the non-skin contact surface side.

FIG. 1 is a perspective view showing a disposable diaper as an embodiment of the present invention. FIG. 2 is an enlarged view of a main part of the surface sheet in the diaper shown in FIG. FIG. 3 is a cross-sectional view in the width direction showing the main part of the crotch part in the diaper shown in FIG. FIG. 4 is a plan view showing an adhesive state between the absorbent core and the core wrap sheet in the diaper shown in FIG. FIGS. 5A to 5D are schematic views showing the state of liquid diffusion and absorption in the diaper shown in FIG.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The disposable diaper as one Embodiment of the absorbent article of this invention is shown by FIG. 2 is a longitudinal sectional view of the crotch part in FIG. The disposable diaper 10 shown in the figure is a tape-type unfolded type. The diaper 10 has a longitudinal direction Y and a width direction X orthogonal to the longitudinal direction Y, and has a long shape in the longitudinal direction Y. The diaper 10 has a crotch portion C in the central region in the longitudinal direction Y. The front and back of the crotch C are an abdominal side A and a back side B.

  The diaper 10 includes a surface sheet 11 located on the side close to the wearer's skin, that is, on the skin contact surface side, and a back sheet 12 positioned on the side far from the wearer's skin, that is, on the non-skin contact surface side. Yes. An absorber 13 is located between the top sheet 11 and the back sheet 12.

  The diaper 10 has a pair of leak-proof cuffs 14 and 14 extending in the longitudinal direction Y on both left and right sides in the width direction X. The leak-proof cuff 14 extends over the entire length of the diaper 10. The leak-proof cuff 14 is composed of a sheet 14 a that is long in the longitudinal direction Y and folded in two along the longitudinal direction Y. The leak-proof cuff 14 has a free end and a fixed end along the longitudinal direction Y. The free end is a portion along the folding line of the folded sheet 14a. At the free end, an elastic member 14b such as rubber thread is arranged and fixed in an extended state. The elastic member 14b is disposed at least in the crotch part C. As the elastic member 14b contracts, the leak-proof cuff 14 has a tendency to stand up toward the wearer's skin. The fixed end of the leak-proof cuff 14 is joined to the back sheet 12 extending laterally from the left and right side edges of the absorber 13. By this joining, leg cuffs 15 are formed on the left and right sides of the diaper 10. In the leg cuff 15, an elastic member 14 c such as a rubber thread is disposed and fixed between the fixed end of the leak-proof cuff 14 and the back sheet 12 in an extended state. The elastic member 14c is disposed at least in the crotch part C. When the elastic member 14c contracts, the leg cuff 15 is in close contact with the circumference of the wearer's leg when the diaper 10 is worn.

  In the diaper 10, a pair of fastening tapes F, F are provided on both left and right edges of the back side B. A landing tape L for fastening fastening tapes F, F is provided on the outer surface of the abdominal side A, that is, the non-skin contact surface of the back sheet 12. The fastening state of the diaper 10 is completed by fastening the fastening tape F to the landing tape L.

  As the top sheet 11, a sheet material having liquid permeability is used. Details of the sheet material will be described below. As the back sheet 12, a liquid-impermeable or liquid-impermeable film or non-woven fabric (for example, spunbond-meltblown-spunbond non-woven fabric) can be used. As the sheet 14 a constituting the leak-proof cuff 14, various non-woven fabrics including a water-repellent sheet material such as a spunbonded non-woven fabric can be used.

  FIG. 3 shows an enlarged view of the main part of the top sheet 11. The top sheet 11 has a concavo-convex structure on each surface. The top sheet 11 has a continuous structure in the surface direction. This “continuous” means that there are no intermittent portions or small holes. However, micropores such as interfiber pores are not included in the small holes.

  The top sheet 11 has a first surface 111 and a second surface 112. The 1st surface 111 is a surface contact | abutted to a wearer's skin. The second surface 112 is a surface facing the absorber 13. On the first surface 111 side of the topsheet 11, a large number of first protrusions 11 a are arranged so as to be obliquely intersected in two vertical and horizontal planes (hereinafter, this arrangement is an oblique grid arrangement). There are times.) This lattice arrangement may be orthogonal (90 °), and in that case, the lattice arrangement may be distinguished as an orthogonal lattice arrangement. In the present embodiment, it is preferable that an arbitrary first direction in the plane and a second direction perpendicular thereto intersect at an angle of 30 ° to 90 °. Furthermore, in this embodiment, many 2nd protrusion parts 11b which protrude in the 2nd surface 112 side of the surface sheet 11 are formed. The second protrusions 11b are also arranged in an oblique grid pattern, but may be an orthogonal grid pattern. Since the preferable range of the crossing angle is determined along with the first protrusion 11a, it is the same as described above. The first projecting portion 11a and the second projecting portion 11b project in opposite directions with respect to the sheet surface. In addition, they are arranged alternately in a non-overlapping relationship that is not in the same position in both a plan view and a side view.

  As described above, the first protruding portion 11a and the second protruding portion 11b arranged to extend in the first direction and the second direction in the plane respectively constitute the surface sheet 11 continuously without contradiction in the surface shape. Yes. Here, “continuous without contradiction” means that when a specific shape portion is continuous and becomes planar, it is not refracted or discontinuous, and the whole is continuous with a gentle curved surface. In addition, the arrangement | sequence form of the 1st protrusion part 11a and the 2nd protrusion part 11b is not limited to the form shown in FIG. 2, What is necessary is just a form which can arrange | position with the arrangement | sequence which can be continued without contradiction. For example, the arrangement may be such that six second protrusions 11b are arranged at the apexes of the hexagon around the first protrusion 11a, and the pattern extends in the plane. In this case, since the number of the second protrusions 11b exceeds the number of the first protrusions 11a, the second protrusions 11b are adjacent to each other. However, as long as a continuous sheet state is formed as a whole. Such an arrangement is also included in the meaning that the first protrusions 11a and the second protrusions 11b are arranged alternately.

  The 1st protrusion part 11a and the 2nd protrusion part 11b are made into the truncated cone shape or hemisphere which rounded the top part. More specifically, the protruding shape of the first protruding portion 11a is not sharp but rather hemispherical, while the protruding shape of the second protruding portion 11b is more sharp and has a cone or truncated cone shape with a round top. It has become. However, the shape of each protrusion part 11a, 11b is not limited to this, What kind of protrusion form may be sufficient. For example, it is practical to have various cone shapes (in this specification, the cone shape means a wide range including a cone, a truncated cone, a pyramid, a truncated pyramid, an oblique cone, and the like).

  The 1st protrusion part 11a and the 2nd protrusion part 11b hold | maintain the frustoconical shape or hemispherical space 11c, 11d with the roundness in the top part similar to the external shape. Each space 11c, 11d is separated through the surface sheet 11, and is formed as a substantially non-continuous space.

  In the present embodiment, when the topsheet 11 is viewed in plan, the first projecting portions 11a and the second projecting portions 11b are formed so as to have a staggered arrangement in a dotted pattern. That is, the first protrusions 11a and the second protrusions 11b appear alternately along the first direction in the plane in the plan view of the topsheet 11, and also along the second direction orthogonal to the first direction. These protrusions 11a and 11b are arranged so that the first protrusions 11a and the second protrusions 11b appear alternately. The surface sheet 11 having such a structure can be suitably manufactured by a method described in JP 2012-136792 A, for example, using various fiber materials as raw materials.

  Due to the fact that at least the surface facing the absorber 13 in the topsheet 11 has a concavo-convex structure, as shown in FIG. A plurality of spaces 11d resulting from the uneven structure are formed. By this space 11d, the topsheet 11 and the absorber 13 are discontinuously separated in the surface direction. This space 11d functions as a temporary stock space for the liquid excreted in the top sheet 11 and permeates the top sheet 11, and suppresses the diffusion of the liquid in the surface direction. The liquid temporarily stocked in the space 11d is absorbed into the absorption layer 13 while suppressing diffusion in the surface direction.

  From the viewpoint of forming a temporary stock space having a sufficient volume, the top sheet 11 has an apparent thickness, that is, a length from the position of the apex of the first protrusion 11a to the position of the apex of the second protrusion 11b is 1 mm or more. In particular, it is preferably 1.5 mm or more, more preferably 4.5 mm or less, and particularly preferably 4.2 mm or less. For example, the apparent thickness of the top sheet 11 is preferably 1 mm or more and 4.5 mm or less, and more preferably 1.5 mm or more and 4.2 mm or less. The apparent thickness of the top sheet 11 is measured in a state where a pressure of 0.05 kPa is applied to the top sheet 11. On the other hand, the thickness of the surface sheet 11 itself is preferably 0.1 mm or more, particularly 0.2 mm or more, more preferably 2 mm or less, and particularly preferably 1.5 mm or less. For example, the thickness of the top sheet 11 itself is preferably from 0.1 mm to 2 mm, and more preferably from 0.2 mm to 1.5 mm.

  The absorber 13 includes an absorbent core 16 and a core wrap sheet 17 that covers the absorbent core 16. The core wrap sheet 17 covers the entire area of at least the upper surface of the absorbent core 16, that is, the entire area of the skin contact surface that is the surface sheet facing surface. Furthermore, it is preferable that the core wrap sheet 17 covers the entire area of the lower surface of the absorbent core 16, that is, the entire area of the non-skin contact surface which is the back sheet facing surface.

  The absorbent core 16 includes pulp fibers and a super absorbent polymer. In the absorbent core 16, the pulp fiber and the superabsorbent polymer are stacked in a mixed state. The pulp fibers and the superabsorbent polymer are not uniformly distributed in the thickness direction Z of the absorbent core 16, but their distribution states are unevenly distributed. Specifically, in the thickness direction Z of the absorbent core 16, the absorbent core 16 is a first surface having a high ratio of the superabsorbent polymer and a first surface having a high ratio of the pulp fibers located on the opposite side of the first surface. Two sides. And the absorption core 16 is distribute | arranged so that the 1st surface may be located in the skin contact surface side, and the 2nd surface may be located in the non-skin contact surface side.

  The superabsorbent polymer in the absorbent core 16 has the highest abundance ratio in the skin contact surface of the absorbent core 16 in the thickness direction Z. The superabsorbent polymer has the lowest abundance ratio on the non-skin contact surface of the absorbent core 16. Between the skin contact surface and the non-skin contact surface, the existence ratio of the superabsorbent polymer decreases from the skin contact surface toward the non-skin contact surface. The reduction method may be, for example, continuously decreasing gradually, or discontinuously decreasing stepwise.

  On the other hand, regarding the pulp fiber, in the thickness direction Z, the existence ratio is the highest on the non-skin contact surface of the absorbent core 16. Further, the existence ratio is the lowest on the skin contact surface of the absorbent core 16. Between the skin contact surface and the non-skin contact surface, the existence ratio of pulp fibers decreases from the non-skin contact surface toward the skin contact surface. The reduction method may be, for example, continuously decreasing gradually, or discontinuously decreasing stepwise.

  As described above, in the absorbent core 16, the superabsorbent polymer is unevenly distributed on the skin contact surface side, while the pulp fibers are unevenly distributed on the non-skin contact surface. By using the absorbent body 13 in which the absorbent core 16 having such a structure is bonded to the core wrap sheet 17 in a specific adhesion pattern in combination with the surface sheet 11 having the concavo-convex structure described above, The diffusion of the liquid can be suppressed, and the liquid can be largely diffused on the non-skin contact surface side. Details of this mechanism will be described later.

  The degree of uneven distribution of the superabsorbent polymer and the pulp fiber in the thickness direction Z of the absorbent core 16 is such that the ratio of the superabsorbent polymer is 60 mass% or more, particularly 65 mass% or more at the skin contact surface and the vicinity thereof. It is preferably 95% by mass or less, particularly preferably 90% by mass or less. On the other hand, the proportion of pulp fibers is preferably 5% by mass or more, particularly preferably 10% by mass or more, and preferably 40% by mass or less, particularly preferably 35% by mass or less. For example, the ratio of the superabsorbent polymer in the skin contact surface and the vicinity thereof is preferably 60% by mass or more and 95% by mass or less, and more preferably 65% by mass or more and 90% by mass or less.

The said skin contact surface and the site | part of the vicinity mean the site | part located in the skin contact surface side among the site | parts which divided the thickness of the absorber into two. On the other hand, the non-skin contact surface and the site in the vicinity thereof refer to a site located on the non-skin contact surface side among sites obtained by dividing the thickness of the absorber into two parts. The ratios of the superabsorbent polymer and the pulp fiber in the skin contact surface and the vicinity thereof and the non-skin contact surface and the vicinity thereof are measured by the following method.
The absorber is cut to a length of 3 cm along the longitudinal direction. The cut part is sandwiched between two acrylic plates. At this time, a gap gauge having the same thickness as the absorber is interposed between the acrylic plates so as not to overlap the absorber, and is sandwiched while maintaining the thickness. Then, the absorber is bisected in the thickness direction using the cutter blade. Each of the skin contact surface divided by the dividing surface and its vicinity, and the non-skin contact surface and the vicinity thereof are put in a mesh bag made of a material having no water retention property, so that the superabsorbent polymer does not fall off. Thus, the following operations are performed for each mesh bag. First, each part is weighed (this value is (A)). Next, each part is immersed in physiological saline for 30 minutes. Then, each part is pulled out from the physiological saline, suspended for 10 minutes, and drained by natural fall. Next, draining with a centrifugal dehydrator is performed for 10 minutes at a speed of 800 rpm for each part. Obtain the amount of water in each part retained after draining with a centrifugal dehydrator (this value is referred to as (B)) (hereinafter, the amount of water retained after draining with a centrifugal dehydrator is referred to as “centrifugal retained amount”) )
On the other hand, the same type of polymer as the superabsorbent polymer contained in each part is weighed, put in a mesh bag, and the same operation as described above is performed to determine the amount of centrifugal retention of the superabsorbent polymer alone. Then, the centrifugal retention amount (C) per 1 g of the superabsorbent polymer is calculated.
Using the values of A, B, and C obtained by the operation as described above, the amount (D) of the superabsorbent polymer in each part is obtained from the calculation of {(B)-(A)} / (C). Further, the ratio of the superabsorbent polymer is obtained from (D) ÷ (A). In addition to this, the ratio of pulp fibers is determined from {(A)-(D)} / (A).

  In the non-skin contact surface of the absorbent core 16 and the vicinity thereof, the ratio of the superabsorbent polymer is preferably 30% by mass or more, particularly preferably 35% by mass or more, and 55% by mass or less, particularly preferably 50% by mass or less. It is preferable that On the other hand, the proportion of the pulp fiber is preferably 45% by mass or more, particularly preferably 50% by mass or more, and is preferably 75% by mass or less, particularly preferably 70% by mass or less. For example, the ratio of the superabsorbent polymer in the non-skin contact surface and the vicinity thereof is preferably 30% by mass to 55% by mass, and more preferably 35% by mass to 50% by mass. On the other hand, the ratio of pulp fibers in the non-skin contact surface and the vicinity thereof is preferably 45% by mass or more and 75% by mass or less, and more preferably 50% by mass or more and 70% by mass or less.

The amount of the superabsorbent polymer in the absorbent core 16 is preferably 30 g / m ² or more, particularly 50 g / m ² or more. The upper limit is preferably 350 g / m ² or less, particularly preferably 300 g / m ² or less. For example, the amount of the superabsorbent polymer is preferably 30 g / m ² or more and 350 g / m ² or less, more preferably 50 g / m ² or more and 300 g / m ² or less. On the other hand, the amount of pulp fibers in the absorbent core 16 is preferably 30 g / m ² or more, particularly 50 g / m ² or more. The upper limit is preferably 300 g / m ² or less, particularly preferably 250 g / m ² or less. For example, the amount of pulp fibers is preferably 30 g / m ² or more and 300 g / m ² or less, more preferably 50 g / m ² or more and 250 g / m ² or less.

  The ratio of the superabsorbent polymer to the pulp fiber in the absorbent core 16 is preferably 1 or more, particularly 1.2 or more, preferably 2 or less, particularly 1 in terms of the mass ratio of [superabsorbent polymer / pulp fiber]. .8 or less is preferable. By setting the amount of each of the superabsorbent polymer and pulp fiber in the absorbent core 16 and the ratio thereof in the above range, a sufficient liquid holding capacity can be ensured without excessively thickening the absorbent core 16. .

The basis weight of the absorbent core 16 itself is preferably 60 g / m ² or more, particularly preferably 70 g / m ² or more. The upper limit is preferably 650 g / m ² or less, particularly 600 g / m ² or less. For example, the basis weight of the absorbent core 16 is preferably 60 g / m ² or more and 650 g / m ² or less, more preferably 70 g / m ² or more and 600 g / m ² or less.

  As the superabsorbent polymer contained in the absorbent core 16, a polymer that can absorb and retain a liquid 20 times or more its own weight and can be gelled is preferable. The shape is not particularly limited, and may be, for example, spherical, massive, grape-like, powdery, or fibrous. The particle size is preferably 1 μm or more and 1000 μm or less, more preferably 10 μm or more and 500 μm or less. Examples of such superabsorbent polymers include polyacrylic acid and salts thereof, and polyacrylate graft polymers such as starch, crosslinked carboxylmethylated cellulose, polymers or copolymers of acrylic acid or alkali metal acrylates. Coalescence can be mentioned. As the polyacrylic acid salt, a sodium salt can be preferably used. In addition, a comonomer such as maleic acid, itaconic acid, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2-hydroxyethyl (meth) acrylate or styrenesulfonic acid is added to acrylic acid. A copolymer copolymerized within a range not deteriorating the performance of the superabsorbent polymer can also be preferably used.

  As the pulp fibers contained in the absorbent core 16, the same fibers as those conventionally used in this type of absorbent article can be used. For example, fluff pulp can be used. The pulp fiber may be crosslinked with cellulose constituting the pulp fiber, if necessary. Alternatively, the pulp fiber may be curled.

  The core wrap sheet 17 that covers the absorbent core 16 is used to improve the shape retention of the absorbent core 16. As the core wrap sheet 17, a liquid-permeable fiber sheet can be used. For example, tissue paper or non-woven fabric can be used. As the nonwoven fabric, for example, a spunbond nonwoven fabric, a spunbond-meltblown-spunbond (SMS) nonwoven fabric, an air-through nonwoven fabric, a spunlace nonwoven fabric, or the like can be used. The core wrap sheet 17 that covers the skin contact surface side of the absorbent core 16 and the core wrap sheet 17 that covers the non-skin contact surface side may be the same or different. Good.

  As shown in FIG. 3, the upper surface of the absorbent core 16 and the core wrap sheet 17 covering the upper surface are intermittently bonded by an adhesive 20. By this adhesion, the shape retention of the absorbent core 16 is further enhanced. The adhesion between the two also contributes to the control of the permeation of the liquid in the thickness direction Z and the diffusion in the surface direction on the upper surface of the absorbent core 16.

  FIG. 4 shows an adhesion pattern between the skin contact surface and non-skin contact surface of the absorbent core 16 and the core wrap sheet 17. As shown in the figure, the upper surface of the absorbent core 16 and the core wrap sheet 17 are joined by an adhesive 20 in a plurality of bonding regions 18 extending along the longitudinal direction Y. Between the adhering regions 18 adjacent in the width direction X is a non-adhering region 19. That is, the adjacent adhesion regions 18 in the width direction X are separated by the non-adhesion region 19. As described above, the upper surface of the absorbent core 16 and the core wrap sheet 17 are joined in the adhesive region 18 continuous in the longitudinal direction Y, and intermittently joined in the width direction X across the non-adhesive region 19. .

  In the embodiment shown in FIG. 4, a plurality of adhesive regions 18 made of the adhesive 20 forming a single line in two rows applied in a spiral shape are formed. However, the application pattern of the adhesive 20 is not limited to a spiral shape, and the adhesive 20 may be applied in a stripe shape with a predetermined width, for example. Alternatively, the adhesive 20 may be applied in an Ω-shaped application pattern. In the embodiment shown in FIG. 4, the adhesive region 18 is formed over the entire length in the longitudinal direction Y of the absorbent core 16. Instead, the adhesive region 18 is part of the longitudinal direction Y of the absorbent core 16. Alternatively, it may be formed so as to extend only. For example, you may form so that the adhesion | attachment area | region 18 may extend only in the approximate center area of the longitudinal direction Y of the absorption core 16. FIG.

  When the upper surface of the absorbent core 16 and the core wrap sheet 17 are joined in a predetermined pattern, when the liquid that has permeated through the top sheet 11 reaches the core wrap sheet 17, the liquid mainly does not adhere to the core wrap sheet 17. It penetrates into the absorbent core 16 through the adhesive region 19 and diffuses in the surface direction within the absorbent core 16. This is because the adhesion region 18 is relatively less likely to transmit liquid than the non-adhesion region 19, and as a result, diffusion of the liquid in the surface direction on the upper surface of the absorbent core 16 is suppressed. Because it is done. In short, when the liquid reaches the absorption core 16, diffusion of the liquid in the surface direction on the upper surface thereof is suppressed, and the liquid diffuses in the surface direction in the absorption core 16. This leads to an advantageous effect that the liquid once absorbed by the absorbent core 16 contributes to the reduction of liquid transfer to the skin and liquid return.

  From the viewpoint of making the above effect even more prominent, the ratio of the area of the adhesion region 18 between the upper surface of the absorbent core 16 and the core wrap sheet 17 and the area of the non-adhesion region 19 is expressed as [area of adhesion region 18 / In terms of the area of the non-adhesion region 19, it is preferably 0.5 or more, particularly preferably 0.6 or more. Further, this ratio is preferably 1.2 or less, particularly 1 or less. For example, this ratio is preferably 0.5 or more and 1.2 or less, and more preferably 0.6 or more and 1 or less.

  From the viewpoint of making the above effects more remarkable, it is preferable that the width of the non-adhesion region 19 is 8 mm or more, particularly 10 mm or more. By applying a plurality of the above-mentioned adhesion regions 18 and forming non-adhesion regions 19 at regular intervals between the adhesion regions 18, the liquid transfer from the topsheet 11 to the absorber 13 is not hindered in the longitudinal direction. This facilitates the diffusion of liquid. The width of the non-adhesion region 19 is preferably 30 mm or less, particularly 25 mm or less. For example, the width of the non-adhesion region 19 is preferably 8 mm or more and 30 mm or less, and more preferably 10 mm or more and 25 mm or less. The area of the adhesive region 18 is the area of the region where the adhesive 20 is actually applied when the adhesive 20 is formed in a stripe shape having a predetermined width. I mean. On the other hand, when the adhesive 20 is applied in a spiral shape as shown in FIG. 4 or is applied in an Ω-shape (not shown), the gap between the end portions of the adhesive 20 in the width direction X is not shown. The product of the length W (see FIG. 4) and the length of the adhesion region 18 is defined as the adhesion area.

  The fact that the upper surface of the absorbent core 16 and the core wrap sheet 17 are intermittently bonded by the bonding region has the advantage that even when the liquid is repeatedly absorbed, diffusion of the liquid in the surface direction is suppressed. is there. Specifically, once the absorbent core 16 absorbs the liquid, the superabsorbent polymer contained therein swells. Due to this swelling, a space is created between the absorbent core 16 and the core wrap sheet 17 disposed on the upper surface thereof. In this case, the extent to which the space is generated is larger in the non-bonded region 19 than in the bonded region 18. Since the liquid can be smoothly transmitted through the space even during the second and subsequent liquid absorption, the diffusion of the liquid in the surface direction is suppressed.

  The above description is the relationship between the upper surface of the absorbent core 16 and the core wrap sheet 17, and the lower surface of the absorbent core 16 and the core wrap sheet 17 extend in the longitudinal direction of the absorbent core 16 as shown in FIG. In this way, the adhesive 20 is applied in a stripe shape. Note that the adhesive pattern of the adhesive 20 is not limited to the pattern shown in FIG. 4, and other patterns may be adopted. In some cases, the lower surface of the absorbent core 16 and the core wrap sheet 17 may not be bonded.

  The liquid permeation absorption mechanism in the diaper of the present embodiment having the above configuration will be described with reference to FIGS. FIG. 5A shows a state immediately after the liquid N is excreted in the diaper 10. In this state, the liquid N is stored in the entire apparent thickness including the concave portion and the space 11d on the skin facing surface side of the topsheet 11 having a concavo-convex structure.

  FIG.5 (b) is the state which the liquid N permeate | transmitted the surface sheet 11, and has transferred to the absorber opposing surface side from the skin contact surface side of this surface sheet. In this state, the liquid N is temporarily stocked in a space 11 d defined between the top sheet 11 and the core wrap sheet 17 in the absorber 13. Since the space 11 is formed discontinuously in the surface direction, the diffusion of the liquid N in the surface direction is suppressed.

  The liquid temporarily stocked in the space 11d then passes through the core wrap sheet 17 as shown in FIG. As described above, the core wrap sheet 17 is bonded to the upper surface 16 a of the absorbent core 16 by the adhesive 20. In this adhesion region, the permeation of the liquid N is suppressed. In particular, as shown in FIG. 4 described above, a plurality of bonding regions are provided along the longitudinal direction of the diaper 10, so that the diffusion of the liquid N in the surface direction is suppressed by each bonding region. As a result, the liquid N is transmitted without excessive diffusion in the surface direction mainly through the non-bonded regions between the bonded regions.

  The liquid N that has passed through the core wrap sheet 17 and reached the absorbent core 16 is unevenly distributed on the upper surface 16a side of the absorbent core 16, that is, on the skin contact surface side, as shown in FIG. Permeates between polymers. Since the superabsorbent polymer has a slower liquid absorption rate than the pulp fiber, the superabsorbent polymer does not absorb the liquid N immediately after the liquid N comes into contact with the superabsorbent polymer. Permeates downward. In addition, since the superabsorbent polymer is unevenly distributed on the skin contact surface side of the absorbent core 16, diffusion of the liquid N in the surface direction is suppressed by the presence of the superabsorbent polymer before liquid absorption and swelling. As a result, the liquid N permeates through the absorbent core 16 toward the back sheet 12 side without excessive diffusion in the surface direction. Then, the liquid N diffuses in the surface direction on the back sheet facing surface side of the absorbent core 16. As a result of such permeation and absorption of the liquid, in the diaper 10 of the present embodiment, liquid transfer to the skin and liquid return are effectively reduced. Moreover, the humidity rise of the space between the diaper 10 and skin is reduced. Furthermore, heat and water vapor can be efficiently dissipated to the outside on the non-skin contact surface side. The diffusion of water vapor occurs when the back sheet 12 has moisture permeability, and the heat dissipation becomes more conspicuous accordingly.

  From the viewpoint of making the above advantageous effects more prominent, the superabsorbent polymer preferably has an absorption rate of 30 seconds or more, particularly 40 seconds or more, and 150 seconds or less, particularly 120 seconds or less. Is preferred. For example, the absorption rate is preferably 30 seconds or longer and 150 seconds or shorter, and more preferably 40 seconds or longer and 120 seconds or shorter. When the superabsorbent polymer has an absorption rate in this range, the time until the superabsorbent polymer starts to absorb the liquid on the skin contact surface side of the absorbent core 16 can be delayed, and the liquid in the absorbent core 16 can be delayed. Is easily transmitted, and the liquid is easily diffused in the surface direction on the opposite surface side of the back sheet 12. In order to obtain a superabsorbent polymer having an absorption rate in this range, for example, the particle size of the absorbent polymer, the primary crosslinking density, the adjustment of the degree of surface crosslinking (postcrosslinking treatment), shape control, various surfactants and polyvalents What is necessary is just to adjust by surface treatment of the absorptive polymer with alcohol, hydrophilic powder, etc.

  Further, the superabsorbent polymer has a centrifugal retention amount in accordance with JIS K 7223 of 25 g / g or more, particularly preferably 30 g / g or more, and preferably 65 g / g or less, particularly preferably 55 g / g or less. For example, the centrifugal holding amount is preferably 25 g / g or more and 65 g / g or less, and more preferably 30 g / g or more and 55 g / g or less. When the superabsorbent polymer has a centrifugal retention amount in this range, the degree of swelling of the superabsorbent polymer after absorbing the liquid increases, and as a result, the permeation path of the liquid in the absorbent core 16 Can be secured. In order to obtain a superabsorbent polymer having a centrifugal retention amount in this range, for example, the degree of surface crosslinking of the absorbent polymer may be adjusted. Generally, when the surface cross-linking degree of the absorbent polymer increases (the surface cross-linking treatment proceeds), the centrifugal retention amount (water absorption capacity) tends to decrease. Specifically, for example, the amount of centrifugal retention can be adjusted by adjusting the amount of the surface cross-linking agent, lowering the surface cross-linking treatment temperature, or shortening the reaction time.

  Further, the superabsorbent polymer has a liquid passage rate under pressure of 20 ml / min or more, particularly 40 ml / min or more, preferably 1000 ml / min or less, particularly preferably 800 ml / min or less. For example, the flow rate under pressure is preferably 20 ml / min or more and 1000 ml / min or less, more preferably 40 ml / min or more and 800 ml / min or less. Since the superabsorbent polymer has a liquid passing rate under pressure in this range, it is possible to ensure a liquid permeation path between the superabsorbent polymers even when the wearer's body pressure is applied to the absorbent core 16. it can. In order to obtain a superabsorbent polymer having a liquid passing rate under pressure in this range, it may be adjusted by, for example, the strength of crosslinking (internal crosslinking and surface crosslinking as required), shape, surface treatment, and the like.

  The absorption rate of the superabsorbent polymer described above can be measured according to the vortex method described in JP-A 2010-017536 [0050]. The amount of centrifugal retention can be measured by the method described in JP-A 2010-017536 [0047]. The liquid passing rate under pressure can be measured by the method described in JP-A-2003-235889, [0008]-[0016].

  As described above, in the diaper 10 of this embodiment, the liquid diffusion area is significantly different between the skin contact surface side and the non-skin contact surface side of the absorbent body 13. For example, in the absorbent body 13, the ratio of the liquid diffusion area on the skin contact surface side and the liquid diffusion area on the non-skin contact surface side is [the liquid diffusion area on the skin contact surface side / non-skin contact]. The diffusion area of the liquid on the surface side] is preferably 0.5 or more, particularly 0.55 or more, and preferably 0.8 or less, particularly preferably 0.75 or less. For example, the ratio is preferably 0.5 or more and 0.8 or less, and more preferably 0.55 or more and 0.75 or less.

The diffusion area is measured as follows. Using a predetermined position of the sample developed on the plane as a liquid injection point, a predetermined amount (40 g) of a colored liquid is injected at a rate of 5 g / sec using a pump, and left for 10 minutes. Thereafter, the top sheet is peeled off, and the colored region on the core wrap sheet on the first surface of the absorbent core is copied onto the OHP sheet. The sample is turned over, the back sheet is peeled off, the core wrap sheet is gently peeled off, and the colored region on the core wrap sheet on the second surface of the absorbent core is copied onto the OHP sheet. The image of the OHP sheet is taken into the scanner, and the diffusion area is calculated using image analysis software Image-Pro Plus (manufactured by Nippon Roper).
For example, artificial urine is used as the liquid used for the measurement of the diffusion area. The composition of artificial urine is 1.94% by weight of urea, 0.795% by weight of sodium chloride, 0.11% by weight of magnesium sulfate, 0.062% by weight of calcium chloride, 0.197% by weight of potassium sulfate, red No. 2 (dye ) 0.010% by mass, water 96.88% by mass and polyoxyethylene lauryl ether (about 0.07% by mass), and the surface tension is adjusted to 53 ± 1 dyne / cm (23 ° C.).

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, in the said embodiment, although each surface in the surface sheet 11 had an uneven structure, it replaces with this and only the opposing surface of the absorber in the surface sheet 11 may have an uneven structure.

  Moreover, although the said embodiment is an example which applied the absorbent article of this invention to the tape-clamp-type deployment type disposable diaper, this invention is an absorbent article of other forms, for example, a pants-type disposable diaper, an incontinence pad, The same applies to sanitary napkins and the like.

This invention discloses the following absorbent articles further regarding embodiment mentioned above.
<1> A longitudinal sheet including a top sheet positioned on the side close to the wearer's skin, a back sheet positioned on the side far from the wearer's skin, and an absorber positioned between the top sheet and the back sheet. And a vertically long absorbent article having a width direction perpendicular thereto,
The absorbent body has an absorbent core and a core wrap sheet that covers the absorbent core,
The absorbent core is a first surface in which pulp fibers and a superabsorbent polymer are mixed, the absorption rate of the superabsorbent polymer is not less than 30 seconds and not more than 150 seconds, and the ratio of the superabsorbent polymer is high. And a second surface located on the opposite side of the first surface and having a high ratio of the pulp fibers,
The absorbent core is arranged such that the first surface is located on the skin contact surface side and the second surface is located on the non-skin contact surface side,
The surface sheet has a concavo-convex structure at least on the side facing the absorber, and a space resulting from the concavo-convex structure is formed between the surface sheet and the absorber.
In the absorbent body, an absorbent article in which the first surface of the absorbent core and the core wrap sheet are intermittently joined in the width direction in a plurality of bonding regions extending along the longitudinal direction.

<2> The absorbent article according to <1>, wherein a mass ratio of [the superabsorbent polymer / the pulp fiber] in the absorbent core is 1 or more and 2 or less.
<3> The basis weight of the superabsorbent polymer in the absorbent core is 30 g / m ² or more and 350 g / m ² or less, and the basis weight of the pulp fiber is 30 g / m ² or more and 300 g / m ² or less. Absorbent article as described in 1> or <2>.
<4> The superabsorbent polymer has a centrifugal retention amount of 25 g / g or more and 65 g / g or less in accordance with JIS K 7223, and a liquid flow rate under pressure of 20 ml / min or more and 1000 ml / min or less. The absorbent article according to any one of <1> to <3>.
<5> The ratio of the area of the adhesion region between the first surface of the absorbent core and the core wrap sheet to the area of the non-adhesion region is expressed as [area of adhesion region / area of non-adhesion region]. The absorbent article according to any one of <1> to <4>, which is 1.2 or less and the width of the non-adhesion region is 8 mm or more.

<6> The absorbent article according to <5>, wherein the width of the non-adhesion region is 30 mm or less.
<7> The ratio of the liquid diffusion area on the skin contact surface side of the absorber and the liquid diffusion area on the non-skin contact surface side is [the liquid diffusion area on the skin contact surface side / non-skin contact The absorbent article according to any one of the above items <1> to <5>, which is expressed in the range of 0.5 to 0.8 in terms of the diffusion area of the liquid on the contact surface side.
<8> The absorbent article according to any one of <1> to <7>, wherein the top sheet and the absorber are discontinuously separated in the surface direction by the space.
<9> The top sheet has a first surface that contacts the skin of the wearer and a second surface that faces the absorber.
On the first surface side, a large number of first projecting portions are arranged so as to obliquely intersect in two vertical and horizontal directions within the plane, and an arbitrary first direction in the plane and a second direction perpendicular thereto However, the absorbent article according to any one of the above items <1> to <8>, which intersect at an angle of 30 ° to 90 °.

<10> The top sheet has a first surface that contacts the skin of the wearer and a second surface that faces the absorber,
A number of first protrusions are arranged on the first surface side,
A large number of second protrusions are arranged on the second surface side,
The first protrusion and the second protrusion protrude in opposite directions with respect to the sheet surface of the topsheet,
The absorbent article according to any one of the above items <1> to <9>, wherein the two protruding portions are not located at the same position in a plan view or a side view, and are alternately arranged in a non-overlapping relationship. .
<11> The arrangement form of the first protrusions and the second protrusions is an arrangement in which six second protrusions are arranged at the hexagonal apexes around the first protrusions, and the pattern spreads in the plane. The absorbent article as described in said <10>.
<12> The protruding shape of the first protruding portion is hemispherical, and the protruding shape of the second protruding portion is sharp and has a rounded cone or truncated cone shape. Absorbent article.

<13> The absorption according to any one of <10> to <12>, wherein the length from the position of the apex of the first protrusion to the position of the apex of the second protrusion is 1 mm to 4.5 mm. Sex goods. <14> The core wrap sheet described in any one of <1> to <13>, wherein the core wrap sheet covers the entire surface of the absorbent core facing the surface sheet and covers the entire surface of the absorbent core facing the back sheet. Absorbent article.
<15> The ratio of the superabsorbent polymer in the absorbent core is from the skin contact surface to the non-skin contact surface between the skin contact surface and the non-skin contact surface in the thickness direction of the absorption core. The absorbent article according to any one of <1> to <14>, wherein the absorbent article is continuously decreasing gradually or discontinuously decreasing stepwise.
<16> The ratio of pulp fibers in the absorbent core is continuous from the non-skin contact surface to the skin contact surface between the skin contact surface and the non-skin contact surface in the thickness direction of the absorption core. The absorbent article according to any one of <1> to <15>, wherein the absorbent article is gradually decreasing or discontinuously decreasing stepwise.

<17> In the skin contact surface of the absorbent core and in the vicinity thereof, the proportion of the superabsorbent polymer is 60% by mass or more and 95% by mass or less, and the proportion of the pulp fiber is 5% by mass or more and 40% by mass or less. The absorbent article according to any one of <1> to <16>.
<18> The <1> to the above, wherein the amount of the superabsorbent polymer in the absorbent core is 30 g / m ² or more and 350 g / m ² or less, and the amount of the pulp fiber is 30 g / m ² or more and 300 g / m ² or less. The absorbent article according to any one of <17>.
<19> The core wrap sheet is made of a liquid-permeable fiber sheet, the liquid-permeable fiber sheet is made of tissue paper or a nonwoven fabric, and the nonwoven fabric is a spunbond nonwoven fabric, a spunbond-meltblown-spunbond (SMS) nonwoven fabric, The absorbent article according to any one of <1> to <18>, comprising an air-through nonwoven fabric or a spunlace nonwoven fabric.
<20> The absorbent article according to any one of <1> to <19>, wherein the adhesive region is formed by applying an adhesive in a spiral, striped, or Ω-shaped application pattern.
<21> It has a longitudinal direction Y and a width direction X orthogonal to the longitudinal direction, has a long shape in the longitudinal direction Y, the central region of the longitudinal direction Y is a crotch portion, and the front and back of the crotch portion are on the ventral side The absorbent article according to any one of <1> to <20>, which is a part and a back side part.

<22> A pair of leak-proof cuffs extending in the longitudinal direction Y are provided on the left and right sides in the width direction X.
The leak-proof cuff extends over the entire length of the absorbent article,
The leak-proof cuff is composed of a sheet that is long in the longitudinal direction Y and folded in two along the longitudinal direction Y.
The leak-proof cuff has a free end and a fixed end along the longitudinal direction Y. The free end is a portion along the folding line of the sheet folded in half, and an elastic member is provided at the free end. The absorbent article according to <21>, wherein the absorbent article is arranged and fixed in an extended state.
<23> Leg cuffs are formed on both left and right sides,
In the leg cuff, the absorbent article according to <22>, wherein the elastic member is disposed and fixed in an extended state between the fixed end of the leak-proof cuff and the back sheet. <24> The absorbent article according to any one of <1> to <23>, which is a disposable diaper.
<25> The absorbent article according to <24>, wherein the absorbent article is a tape-fastened type disposable disposable diaper.
<26> In the above <25>, a pair of fastening tapes are provided on the left and right side edges of the back side, and a landing tape is provided on the outer surface of the abdominal side to fasten the fastening tape. The absorbent article as described.
<27> The absorbent article according to <24>, which is a pants-type disposable diaper.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples. Unless otherwise specified, “%” means “mass%”.

[Example 1]
A baby M-size disposable diaper having the form shown in FIG. 1 was produced. The surface sheet in a diaper consists of the nonwoven fabric of the form shown in FIG. 2, and this nonwoven fabric was manufactured by the method similar to the method of Example 1 of Unexamined-Japanese-Patent No. 2012-136792. The basis weight of this nonwoven fabric is 30 g / m ² , and the protrusions on one surface are arranged in a staggered pattern. The pitch of the protrusions was 5 mm. The same applies to the other surface. The thickness of the nonwoven fabric was 2.1 mm under a load of 0.05 kPa. As the back sheet in the diaper, a liquid-impermeable polyethylene film was used. As the leakproof cuff, a water-repellent spunbond-meltblown-spunbond nonwoven fabric was used. The absorbent core in the absorbent body was composed of fluff pulp and superabsorbent polymer. The basis weight of the fluff pulp contained in the entire absorbent core was 172 g / m ² , and the basis weight of the superabsorbent polymer was 257 g / m ² . As a method of making the existence ratio of fluff pulp and superabsorbent polymer different between the skin contact surface side and the non-skin contact surface side in the absorbent core, the method described in JP-A-2007-37668 was adopted. As a result, in the absorbent core, the ratio of the superabsorbent polymer gradually decreases from the skin contact surface side to the non-skin contact surface side, and from the non-skin contact surface side to the skin contact surface side. As a result, the proportion of fluff pulp gradually decreased. The existence ratio of the superabsorbent polymer in the skin contact surface and the vicinity thereof was 69.3%. On the other hand, the existence ratio of fluff pulp in the non-skin contact surface and the vicinity thereof was 63.8%. The superabsorbent polymer used is polymer A shown in Table 1. Polymer A had an absorption rate of 65 seconds, a centrifugal retention amount based on JIS K 7223 of 31.5 g / g, and a liquid flow rate under pressure of 70 ml / min. As the core wrap sheet for wrapping the absorbent core, natural pulp NBKP having a basis weight of 18 g / m ² was used. The skin contact surface of the absorbent core and the core wrap sheet were joined with a hot melt adhesive. The hot melt pressure-sensitive adhesive was applied by using a summit spray and adopting a spiral pattern in one row in two rows as shown in FIG. The thickness of the spiral was 0.05 to 0.2 mm, and the width W of the coating region formed of spirals forming one line in two rows shown in FIG. 4 was 5.5 mm. Five width summit coating areas were formed. The distance between adjacent summit coating areas was 12 mm. The total coating amount of the hot melt adhesive was 3 g / m ² .

[Example 2]
In Example 1, the basis weight of the pulp and the basis weight of the superabsorbent polymer in the absorbent core were as shown in Table 1. Moreover, the polymer B shown in Table 1 was used as a superabsorbent polymer. Polymer B had an absorption rate of 44 seconds, a centrifugal retention amount based on JIS K 7223 of 32.8 g / g, and a liquid flow rate under pressure of 21 ml / min. Except this, a disposable diaper was produced in the same manner as in Example 1.

Example 3
In Example 1, the basis weight of the pulp and the basis weight of the superabsorbent polymer in the absorbent core were as shown in Table 1. Except this, a disposable diaper was produced in the same manner as in Example 1.

[Comparative Example 1]
This comparative example is obtained by changing the application pattern of the hot melt adhesive applied between the skin contact surface of the absorbent core and the core wrap sheet in Example 1. Moreover, the front and back of the absorption core used in Example 1 are reversed. The coating pattern of the hot melt adhesive in this comparative example was a coater stripe. The thickness of the coater was 2.5 mm, and the distance between adjacent coaters was 2.5 mm. Moreover, the total coating amount of the hot melt pressure-sensitive adhesive was 3 g / m ² . Except these, it carried out similarly to Example 1, and obtained the disposable diaper.

[Comparative Example 2]
This comparative example is an example in which a flat nonwoven fabric was used as the surface sheet instead of the surface sheet having the uneven shape used in Example 1. This flat nonwoven fabric has a basis weight of 25 g of a two-layer structure composed of a composite fiber of 2.0 dtex of polyethylene terephthalate (PET) and polyethylene (PE) and a composite fiber of 5.6 dtex of polypropylene (PP) and polyethylene (PE). / M ² air-through nonwoven fabric. Except these, it carried out similarly to Example 1, and obtained the disposable diaper.

[Comparative Example 3]
In this comparative example, instead of the polymer B which is a superabsorbent polymer used in Example 2, a polymer C which is a superabsorbent polymer having a high absorption rate and a relatively small amount of centrifugal retention is used. Polymer C had an absorption rate of 3 seconds, a centrifugal retention amount based on JIS K 7223 of 23.4 g / g, and a liquid flow rate under pressure of 0 ml / min. Except these, it carried out similarly to Example 2, and obtained the disposable diaper.

[Comparative Example 4]
In this comparative example, instead of the polymer A which is a superabsorbent polymer used in Example 1, a polymer D which is a superabsorbent polymer having a high absorption rate and a relatively small centrifugal retention amount is used. Polymer D had an absorption rate of 29 seconds, a centrifugal retention amount according to JIS K 7223 of 25.3 g / g, and a liquid flow rate under pressure of 130 ml / min. Moreover, the basic weight of the fluff pulp contained in the whole absorption core was 191 g / m < ² >, and the basic weight of the superabsorbent polymer was 300 g / m < ² >. Except these, it carried out similarly to Example 1, and obtained the disposable diaper.

[Comparative Example 5]
This comparative example is an example in which another absorbent core is used instead of the absorbent core used in Example 1. The basis weight of the fluff pulp contained in the absorbent core used in this comparative example was 200 g / m ² , and the basis weight of the superabsorbent polymer was 186 g / m ² . The presence state of fluff pulp and superabsorbent polymer in the absorbent core was almost uniform, and the proportion of superabsorbent polymer present in the skin contact surface and the vicinity thereof was 48.5%. On the other hand, the existence ratio of fluff pulp in the non-skin contact surface and the vicinity thereof was 52.1%. Except these, it carried out similarly to Example 1, and obtained the disposable diaper.

[Evaluation]
About the diaper obtained by the Example and the comparative example, the grade of the spreading | diffusion of the liquid to the surface direction in the skin contact surface side and non-skin contact surface side of an absorber was measured by the method mentioned above. The results are shown in Table 1 below.

  As is clear from the results shown in Table 1, it can be seen that the diaper of each example (product of the present invention) has a smaller liquid spreading area on the skin contact surface side than the diaper of each comparative example. It can also be seen that the diaper of each example has a smaller ratio of the liquid spreading area on the skin contact surface side to the liquid spreading area on the non-skin contact surface side than the diaper of each comparative example.

DESCRIPTION OF SYMBOLS 10 Disposable diaper 11 Top sheet 11a 1st protrusion part 11b 2nd protrusion part 11d Space 111 1st surface of surface sheet 112 2nd surface 12 of surface sheet Back sheet 13 Absorber 14 Leak cuff 15 Leg cuff 16 Absorption core 17 Core wrap Sheet 18 Adhesive area 19 Non-adhesive area 20 Adhesive

Claims (4)

A top sheet located on the side close to the wearer's skin, a back sheet located on the side far from the wearer's skin, and an absorber positioned between the top sheet and the back sheet, and in the longitudinal direction and perpendicular thereto A vertically long absorbent article having a width direction to
The absorbent body has an absorbent core and a core wrap sheet that covers the absorbent core,
The absorbent core is a first surface in which pulp fibers and a superabsorbent polymer are mixed, the absorption rate of the superabsorbent polymer is not less than 30 seconds and not more than 150 seconds, and the ratio of the superabsorbent polymer is high. And a second surface located on the opposite side of the first surface and having a high ratio of the pulp fibers,
The absorbent core is arranged such that the first surface is located on the skin contact surface side and the second surface is located on the non-skin contact surface side,
The top sheet has a first surface that contacts the skin of the wearer and a second surface that faces the absorber,
A number of first protrusions are arranged on the first surface side,
A large number of second protrusions are arranged on the second surface side,
The projecting shape of the first projecting part is hemispherical, the projecting shape of the second projecting part is a sharp cone and a truncated cone shape with a round top.
The first protrusion and the second protrusion protrude in opposite directions with respect to the sheet surface of the surface sheet,
Both projecting portions are not located at the same position in a plan view or a side view, and are alternately arranged in a non-overlapping relationship.
Wherein between the surface sheet and the absorbent body, wherein which the space due to the uneven structure of the both projecting portions are formed,
In the absorbent body, the first surface of the absorbent core and the core wrap sheet are intermittently joined in the width direction in a plurality of bonding regions extending along the longitudinal direction ,
The ratio of the area of the adhesion region and the area of the non-adhesion region between the first surface of the absorbent core and the core wrap sheet is 0.5 or more and 1 expressed as [area of adhesion region / area of non-adhesion region]. .2 or less, and the width of the non-adhesive region is 8 mm or more,
The ratio of the liquid diffusion area on the skin contact surface side of the absorber and the liquid diffusion area on the non-skin contact surface side is [the liquid diffusion area on the skin contact surface side / non-skin contact surface side] the absorbent article Ru der 0.5 and 0.8 expressed in spread area] of the liquid in.   The absorbent article according to claim 1, wherein a mass ratio of [the superabsorbent polymer / the pulp fiber] in the absorbent core is 1 or more and 2 or less. The absorbent basis weight of the high absorbent polymer in the core is at 30 g / m ² or more 350 g / m ² or less, according to claim 1 or 2 basis weight of the pulp fibers is 30 g / m ² or more 300 g / m ² or less Absorbent article as described in 1.   The superabsorbent polymer has a centrifugal retention amount of 25 g / g or more and 65 g / g or less according to JIS K 7223, and a liquid passing rate under pressure of 20 ml / min or more and 1000 ml / min or less. The absorbent article as described in any one of 3.

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