WO2012117764A1

WO2012117764A1 - Absorbent article

Info

Publication number: WO2012117764A1
Application number: PCT/JP2012/051156
Authority: WO
Inventors: 祐介川上; 翔士高阪; 信弘多川
Original assignee: ユニ・チャーム株式会社
Priority date: 2011-02-28
Filing date: 2012-01-20
Publication date: 2012-09-07
Also published as: JP2012179182A; JP5695445B2

Abstract

Provided is an absorbent article that efficiently increases the volume of excreta that can be absorbed and held. The liquid-absorbing pad (1) has a skin-facing surface and a non-skin-facing surface and is equipped with a surface sheet (2) disposed on the skin-facing surface, a back sheet (3) disposed on the non-skin-facing surface, and a liquid-absorbing structure (10) that lies between the surface sheet (2) and the back sheet (3). The liquid-absorbing structure (10) comprises two superposed layers, a first and a second absorption layer (21, 41). The first absorption layer (21) is disposed on the skin-facing surface side, and has a particle-comprising region (24) where absorbent polymer particles are present and a particle-less region (25) where the absorbent polymer particles are substantially absent. The second absorption layer (41) is disposed on the non-skin-facing surface side, comprises hydrophilic fibers (19) and absorbent polymer particles, and is formed so as to have a high density region (44) where the density of hydrophilic fibers (19) is high and a low density region (45) where the density of hydrophilic fibers (19) is low. The first absorption layer (21) is layered on the second absorption layer (41) so that the particle-less region (25) and the low density region (45) overlap. The low density region (45) and the high density region (44) are connected via the hydrophilic fibers (19).

Description

Absorbent articles

The present invention relates to an absorbent article, and more particularly, to an absorbent article such as a light incontinence pad, a panty liner, a sanitary napkin, a urine absorption pad, and a liquid absorption pad.

Conventionally, an absorptive article provided with a liquid absorptive structure formed with two absorption layers is publicly known.
For example, Patent Document 1 discloses a liquid-absorbing structure formed by a first absorbent layer located on the skin facing surface side and a second absorbent layer located on the non-skin facing surface side. The first absorbent layer includes absorbent polymer particles, and the second absorbent layer is formed to include absorbent fibers and absorbent polymer particles.
Furthermore, the first absorbent layer is provided with a row of existing regions where the absorbent polymer particles are present, and the non-absorbent fibers and the absorbent polymer particles are not substantially present between the adjacent existing regions. An existence area is provided.

According to this absorbent article, since the non-existing region where the absorbent polymer particles do not exist is provided, when the excrement is absorbed and retained in the first absorbent layer, the gel block of the absorbent polymer particles is present in the non-existing region. It does not occur. Therefore, excrement that has passed through the non-existing region of the first absorption layer can be absorbed and held by the second absorption layer. Accordingly, since the excrement can be absorbed and held in the second absorption layer in addition to the first absorption layer, the capacity of excretion that can be absorbed and held can be increased.

JP 2004-275225 A

In the absorbent article disclosed in Patent Document 1, excreta that has passed through the non-existing region of the first absorbent layer is changed from a site that overlaps the non-existing region to a site that overlaps the existing region in the second absorbent layer. Will spread towards.

However, the second absorbent layer of the absorbent article disclosed in Patent Document 1 has a substantially uniform density of absorbent fibers and a substantially constant thickness. There is no technical consideration for spreading excrement vertically and horizontally. Therefore, in the second absorption layer, the excrement cannot be efficiently diffused vertically and horizontally, and the excrement can be absorbed and retained in the portion that overlaps the non-existing area, but the excrement cannot be absorbed in the part that overlaps the existing area. It cannot be absorbed and retained. Therefore, there is a problem that excreta cannot be absorbed and held by the entire second absorption layer.

Therefore, in the present invention, it is an object to provide an absorbent article capable of absorbing and holding excrement throughout the second absorption layer.

In order to solve the above problems, an absorbent article according to the present invention has a skin facing surface and a non-skin facing surface, and is positioned on the skin facing surface side and on the non-skin facing surface side. A back sheet, and a liquid absorbing structure interposed between the top sheet and the back sheet.

In this absorbent article, the feature of the present invention is that the liquid-absorbent structure has at least two first and second absorbent layers that overlap each other, and the first absorbent layer has the skin facing surface. The second absorbent layer is disposed on the side of the non-skin-facing surface, and has a presence region where the absorbent polymer particles are present and a non-existence region where the absorbent polymer particles are substantially absent. The hydrophilic fibers and the absorbent polymer particles are disposed and formed so as to have a high density region where the density of the hydrophilic fibers is high and a low density region where the density of the hydrophilic fibers is low, and the absence The first absorbent layer is laminated on the second absorbent layer so that the region and a part of the low density region overlap, and the low density region and the high density region are connected via the hydrophilic fiber. It is what.

In one preferred embodiment of the present invention, the liquid-absorbent structure has a horizontal direction, a vertical direction, and a thickness direction, and the high-density region has a dimension in the thickness direction of the low-density region. It is formed by compressing in the thickness direction so as to be smaller than the dimension in the thickness direction.

In another preferred embodiment of the present invention, the existence area is formed in an elongated shape that is longer in the vertical direction than the horizontal direction, while the non-existence area is in the horizontal direction of the existence area. The first absorption so that a part of the high-density region and a part of the low-density region overlap the non-existing region in the central portion in the longitudinal direction, respectively. A layer is laminated to the second absorption layer.

In another preferred embodiment of the present invention, the existence region has at least a central existence region disposed in the central portion in the lateral direction, and the low-density region at both end edges in the vertical direction. The horizontal dimension of the central existence area is smaller than the horizontal dimension of the low density area, and the vertical dimension of the low density area is smaller than the vertical dimension of the central existence area, the vertical direction The center existing region extends beyond the low density region at both end edges, and in the thickness direction, the skin facing surfaces of both end edges in the longitudinal direction of the low density region are covered with the center existing region. Yes.

In another preferred embodiment of the present invention, the low density region extends in the lateral direction from the center existing region at the central portion in the longitudinal direction.

In another preferred embodiment of the present invention, the length of the portion where the low-density region extends from the central existence region in the lateral direction is the largest in the central portion in the longitudinal direction, and from the central portion. It becomes gradually smaller as the distance increases.

In another preferred embodiment of the present invention, in addition to the central existence area, the existence area is provided with at least two side existence areas arranged in the lateral direction on both sides of the central existence area. The side-existing region overlaps the high-density region.

In another preferred embodiment of the present invention, the center existing region has a narrowest width portion in which the dimension in the horizontal direction is the smallest in the central portion in the vertical direction, while both edge portions in the vertical direction are provided. The side-existing region has the widest part having the largest horizontal dimension at the central part in the vertical direction, and the both ends in the vertical direction. And the narrowest width portion having the smallest horizontal dimension.

In another preferred embodiment of the present invention, the low density region has a widest portion in which a dimension in the lateral direction is large at a central portion in the longitudinal direction, while the both end edges in the longitudinal direction are It has the narrowest width part where the dimension of a horizontal direction becomes small.

In another preferred embodiment of the present invention, the central existence area and the side existence area each have a substantially rectangular shape extending in the vertical direction so that the width in the horizontal direction is substantially constant.

According to the absorbent article according to one or more embodiments of the present invention, the first absorbent layer is laminated on the second absorbent layer so that the non-existing region and a part of the low-density region overlap each other. Therefore, even if a gel block is generated in the existing region due to excrement, the excrement can be absorbed and held in the low density region through the non-existing region. Moreover, since the low density region and the high density region are connected via the hydrophilic fiber, the excrement in the low density region can be diffused in the high density region. Therefore, in the 2nd absorption layer, the area which can absorb and hold excrement can be enlarged, and excrement can be absorbed and held in the 2nd absorption layer whole.

The partially broken top view of the liquid absorption pad as an example of the absorbent article in 1st Embodiment of this invention. II-II sectional view taken on the line of FIG. The partially broken top view of a 1st absorption layer. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. The top view of the 2nd absorption layer. FIG. 6 is a sectional view taken along line VI-VI in FIG. 5. The enlarged view of the part shown by VII of FIG. VIII-VIII sectional view taken on the line of FIG. The perspective view of an emboss press process. The partially broken top view of the liquid absorption pad in 2nd Embodiment. The top view of the liquid absorption pad in 3rd Embodiment. FIG. 12 is a sectional view taken along line XII-XII in FIG. 11.

Referring to the accompanying drawings, an embodiment of a liquid absorbent pad which is an example of an absorbent article according to the present invention will be described as follows.

<First Embodiment>
FIG. 1 is a partially broken plan view of a liquid absorption pad according to the first embodiment, and FIG. 2 is a cross-sectional view taken along the line II-II in FIG. In the figure, X indicates a horizontal direction, Y indicates a vertical direction orthogonal to the horizontal direction X, Z indicates a thickness direction orthogonal to the horizontal direction X and the vertical direction Y, and P indicates a horizontal direction of the liquid absorption pad. A virtual vertical center line that bisects the length dimension of X is shown, and Q shows a virtual horizontal center line that bisects the length dimension of the liquid absorption pad in the vertical direction Y.

1 and 2, the liquid absorption pad 1 is formed symmetrically with respect to the virtual vertical center line P and the virtual horizontal center line Q, and faces the wearer's skin (hereinafter simply referred to as “skin facing surface”). ) And the opposite surface (hereinafter, simply referred to as “non-skin facing surface”), and the top sheet 2 positioned on the skin facing surface side and the back sheet 3 positioned on the non-skin facing surface side And a liquid-absorbing structure 10 interposed between the top sheet 2 and the back sheet 3.
The top sheet 2 and the back sheet 3 have a peripheral edge 6 formed larger than the dimension of the liquid-absorbent structure 10 in the horizontal direction X and the vertical direction Y. The peripheral edge 6 has both end edges 4 in the vertical direction Y and both side edges 5 in the horizontal direction X. The top sheet 2 and the back sheet 3 are joined to each other at the peripheral edge portion 6 by a known joining means, for example, a hot melt adhesive (not shown) applied between them.

The top sheet 2 is a liquid non-woven fabric formed from a thermoplastic synthetic resin, and an air-through non-woven fabric, a point bond non-woven fabric, a spun bond non-woven fabric or the like can be used. As the thermoplastic synthetic resin, polyethylene, polypropylene, a composite thereof, polyethylene terephthalate, or the like can be used. The mass per unit area of the surface sheet 2 is, for example, about 15 to 60 g / m ² , preferably about 18 to 45 g / m ² , and the thickness is about 0.15 to 0.60 mm.

The back sheet 3 is a non-liquid-permeable or liquid-impervious fiber nonwoven fabric formed from a thermoplastic synthetic resin, and is a spunbond / meltblown / spunbond (SMS) fiber nonwoven fabric, an air-through fiber nonwoven fabric, or a point bond fiber. A nonwoven fabric, a spunbond fiber nonwoven fabric, etc. can be used. As the thermoplastic synthetic resin, for example, the above-described synthetic resin such as polyethylene can be used, but it is preferable to use the same resin as that used for the topsheet 2. The mass per unit area of the back sheet 3 is, for example, about 15 to 60 g / m ² , preferably about 18 to 45 g / m ² , and the thickness is 0.15 to 0.60 mm. In addition, the back sheet 3 can also use what laminated | stacked the liquid-impervious and moisture-permeable plastic film on the skin opposing surface side of a fiber nonwoven fabric, or the non-skin opposing surface side. Moreover, when using this liquid absorption pad 1 on another absorbent article, a liquid-permeable fiber nonwoven fabric can be used for the back surface sheet 3.

The liquid-absorbing structure 10 includes a first absorbent layer 21 located on the skin facing surface side and a second absorbent layer 41 located on the non-skin facing surface side. For example, the first absorbent layer 21 and the top sheet 2, the second absorbent layer 41 and the back sheet 3, and the first absorbent layer 21 and the second absorbent layer 41 are intermittent on at least one of the opposing surfaces. Each of them is joined by a hot-melt adhesive applied.

FIG. 3 is a partially broken plan view of the first absorption layer 21, and FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG.

Referring to FIGS. 3 and 4, the first absorbent layer 21 includes, for example, a first absorbent core 22 formed only from absorbent polymer particles, and a liquid-permeable wrapping sheet 23 covering the first absorbent core 22. Including.

The absorbent polymer particles are, for example, starch-based, acrylic acid-based, amino acid-based particles or fibers, and are water-insoluble and water-swellable polymers having a water absorption capacity of at least several tens of times the self-mass. Can be used. For the wrapping sheet 23, a liquid-permeable fiber nonwoven fabric can be used. The first absorbent layer 21 is juxtaposed in the longitudinal direction Y, and has an existing region 24 containing absorbent polymer particles and a non-existing region 25 not containing absorbent polymer particles.

The presence region 24 is preferably formed of absorbent polymer particles having a mass of about 100 to 400 g / m ² . The existence area 24 has a central existence area 24a arranged at the center in the horizontal direction X, and a first side existence area 24b and a second side existence area 24c arranged on both sides of the central existence area 24a in the horizontal direction X, respectively. Yes.

The center existence region 24a is formed in an elongated shape with respect to the absorbent structure 10 in which the dimension in the lateral direction X is relatively small and the dimension in the longitudinal direction Y is relatively large. In addition, in the longitudinal direction Y, the central existence region 24a is arranged such that the core side edges 35 in the horizontal direction X are closest to each other on the virtual horizontal center line Q, while the both side edges 35 are separated from the virtual horizontal center line Q. So as to be gradually separated from each other, the narrowest portion 28 is provided at the central portion 26 located at the center in the longitudinal direction Y, and the widest portion 29 is provided at both end edges 27 located at the end portions in the longitudinal direction Y. Is formed. In other words, the center existing region 24a has the narrowest width portion 28 where the dimension in the horizontal direction X becomes smaller at the central portion 26, while the widest width portion 29 where the dimension in the horizontal direction X becomes larger at both end edges 27. is doing.

The first and second

side existence regions

24b and 24c are formed in an elongated shape in which the dimension in the horizontal direction X is relatively small with respect to the central part 26 and the dimension in the vertical direction Y is larger than that of the central part 26. is there. In addition, in the first and second

side existence regions

24b and 24c, the outer edge 30a that is separated from the virtual vertical center line P extends substantially parallel to the virtual vertical center line P, while close to the virtual vertical center line P. The inner edges 30b that are in the longitudinal direction Y are closest to each other on the virtual lateral center line Q and are separated from each other as the distance from the virtual lateral center line Q increases. And the widest portion 26b, and both end edges 27a located at both end edges in the longitudinal direction Y are formed to have the narrowest portion 29a.

The non-existing region 25 is, in the lateral direction X, between the first non-existing region 25a located between the central existing region 24a and the first-side existing region 24b, and between the central existing region 24a and the second-side existing region 24c. And a second non-existing region 25b. The first and second

non-existing regions

25a and 25b are closest to each other on the virtual horizontal center line Q in the vertical direction Y, and are separated from each other as the distance from the virtual horizontal center line Q increases. It is formed so as to extend in the longitudinal direction Y so that the dimensions are substantially constant.

The wrapping sheet 23 sandwiches the first absorbent core 22 between the first sheet 31 located on the skin facing surface side and the first sheet 31 and is located on the non-skin facing surface side. 32. The areas of the first sheet 31 and the second sheet 32 are larger than the total area of the existence area 24 and the non-existence area 25, and both longitudinal edges of the

sheets

31, 32 are arranged at both

edge parts

27 and 27. End flaps 33 are formed to extend outward in the longitudinal direction Y from both end edges 27a, and both side edges of the

sheets

31, 32 extend to the outside in the lateral direction X from the outer edges 30a to form side flaps 34. . The end flap 33 is left in the state of extending in the longitudinal direction Y, while the side flap 34 is bent to the lower side of the first and second

side existence regions

24b and 24c in FIG. In addition, the area of the first sheet 31 is larger than the area of the second sheet 32, and the first wrapping both side edges 31 a of the first sheet 31 in the side flap 34 are the second of the second sheet 32. It protrudes further than the wrapping side edges 32a. The first sheet 31 and the second sheet 32 are bonded to each other at a side flap 34 and an end flap 33 with a hot melt adhesive (not shown) applied to at least one of the

sheets

31 and 32, for example. . Although not shown, the

sheets

31 and 32 may be joined in the

non-existing regions

25a and 25b with a hot melt adhesive applied to at least one of the

sheets

31 and 32. By joining in this way, it is possible to prevent the shape and position of the first absorbent core 22 from being deformed. Further, in the case of joining in this way, the

sheets

2 and 31 are joined to the lower sheet 32 in the

non-existing regions

25a and 25b, and grooves are formed on the upper surface and / or the lower surface in the

non-existing regions

25a and 25b. It is preferable.

5 is a plan view of the second absorption layer 41, and FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG.

Referring to FIGS. 5 and 6, the second absorbent layer 41 has a dimension in the longitudinal direction Y larger than the dimension in the same direction of the first absorbent layer 21, and both end edges 41 a thereof are the first absorbent layer 21. It arrange | positions so that it may extend outside the both-ends edge part 21a (refer FIG. 1). Further, the second absorption layer 41 has the horizontal dimension X substantially the same as the first absorption layer 21 in the same direction, both side edges 41b and both side edges of the first absorption layer 21. 21b substantially coincides with the virtual horizontal center line Q (see FIG. 1).
The second absorbent layer 41 includes a second absorbent core 42 formed by mixing the hydrophilic fibers 19 and the absorbent polymer particles 18, and a second wrapping sheet 43 covering the second absorbent core 42. .
As the hydrophilic fiber 19, natural pulp fiber such as wood fluff pulp, regenerated fiber such as rayon staple, and a mixture thereof can be used. For example, as the hydrophilic fiber 19, a wood fluff pulp fiber having an average length of about 0.5 to 3.0 mm can be preferably used. As the absorbent polymer particles 18, the same particles as the first absorbent core 22 can be used. For the wrapping sheet 23, a liquid-permeable fiber nonwoven fabric can be used.

In the second absorbent core 42, the density of the hydrophilic fibers 19 and the absorbent polymer particles 18 is relatively high, and the density of the hydrophilic fibers 19 and the absorbent polymer particles 18 is relatively low. A low density region 45 and an intermediate region 46 disposed between them are formed.

The high density region 44 is disposed on the periphery of the second absorption layer 41 including both side edge portions 41b and both end edge portions 41a. The high-density region 44 is disposed on the outermost side with respect to the intersection point O where the virtual vertical center line P and the virtual horizontal center line Q intersect. The dimension in the thickness direction Z of the high-density region 44 is preferably about 1.3 to 1.7 mm. The density of the high density region 44 is higher than the density of the low density region 45. More specifically, the high-density region 44, the mass is absorbent polymer particles 18 of about 100 ~ 400g / ^{m 2,} mass is formed by mixing the hydrophilic fibers 19 of about 150 ~ 400g / ^{m 2} it is preferred, the absorbent polymer particles 18 of the mass about 116 ~ 196g / ^{m 2,} and more preferably the mass is formed by mixing the hydrophilic fibers 19 of about 160 ~ 210g / ^{m 2,} a density of about It is preferably 0.10 to 0.80 g / cm ³ . The density of the hydrophilic fibers 19 in the high density region 44 is preferably about 0.05 to 0.40 g / cm ³ , and is higher than the density of the hydrophilic fibers 19 in the low density region 45. A large number of pressing recesses 54 are formed on the skin-facing surface of the high-density region 44.

7 is a partially enlarged view of the skin facing surface of the high-density region 44 indicated by VII in FIG. 5, and FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG.
7 and 8, each pressing recess 54 is recessed from the skin facing surface toward the non-skin facing surface, and has a substantially rectangular shape in the vertical and horizontal directions. The pressing recess 54 is defined by the protruding

walls

51 and 52. The protruding

walls

51 and 52 protrude on the skin facing surface, extend in a line shape so as to be inclined with respect to the vertical direction Y and the horizontal direction X in the vertical and horizontal directions, and the protruding wall 51 and the protruding wall 52 intersect each other. A lattice pattern is formed. More specifically, the first protruding wall 51 intersects the virtual line 53 parallel to the virtual lateral center line Q at the first angle α, while the second protruding wall 52 is relative to the virtual line 53. Intersect at the second angle β. The first angle α is 45 degrees, for example, and the second angle β is 135 degrees, for example, and the first protruding wall 51 and the second protruding wall 52 are orthogonal to each other. The widths t1 and t2 of the protruding

walls

51 and 52 are, for example, about 0.5 to 1.5 mm, preferably about 1 mm, and the depth dimension of the pressing recess 54 in the thickness direction Z is, for example, about 0.00 mm. It is 5 to 1.5 mm, preferably 1 mm, and the vertical and horizontal intervals t3 and t4 of each pressing recess 54 are, for example, about 2.0 to 5.0 mm, preferably about 4 mm.
The density of the pressing recesses 54 is higher than the density of the protruding

walls

51 and 52. Specifically, the density of the pressing recesses 54 is preferably, for example, 0.25 to 0.80 g / cm ³ , and the density of the protruding

walls

51 and 52 is, for example, preferably 0.10 to 0.55 g / cm ^3. .

Referring to FIGS. 5 and 6 again, the low density region 45 is formed in an elongated rectangular shape whose dimension in the vertical direction Y is larger than the dimension in the horizontal direction X, and includes the intersection point O. It is arranged at the center of the second absorption layer 41 in the vertical and horizontal directions in an enclosed manner. The low density region 45 has a substantially constant dimension in the thickness direction Z. For example, in the thickness direction Z, the low density region 45 has a compressive force smaller than the compressive force applied to the hydrophilic fibers 19 and the absorbent polymer particles 18 when forming the high density region 44, as will be described later. It is formed by adding. The dimension in the thickness direction Z of the low density region 45 is preferably greater than about 1.7 and not greater than 3.7 mm.
In the low density region 45, the horizontal direction X dimension X1 is smaller than the horizontal direction X dimension X2 of the center existing region 24a at the low region both end edges 45a in the vertical direction Y (see FIG. 1). Moreover, the dimension Y1 in the longitudinal direction Y of the low density region 45 is smaller than the dimension Y2 in the longitudinal direction Y of the central existence region 24a. As a result, in the longitudinal direction Y, both end edges 27 of the center existing region 24a extend from the low region end edges 45a of the low density region 45, and in the thickness direction Z, the low region end edges 45a face each other. The surface is covered with both edge portions 27.

Low-density regions 45 are, specifically, mass and absorbent polymer particles 18 of about 100 ~ 700g / ^{m 2,} that the mass is formed by mixing the hydrophilic fibers 19 of about 150 ~ 700g / ^{m 2} preferably, the absorbent polymer particles 18 of the mass about 116 ~ 364g / ^{m 2,} and more preferably the mass is formed by mixing the hydrophilic fibers 19 of about 160 ~ 390g / ^{m 2,} a density of about 0 It is preferably formed in the range of 0.05 to 0.50 g / cm ³ . The density of the hydrophilic fibers 19 in the low density region 45 is preferably about 0.03 to 0.25 g / cm ³ and is lower than the density of the hydrophilic fibers 19 in the high density region 44.

The intermediate region 46 is arranged between the high-density region 4 and the low-density region 45 in the vertical and horizontal directions. The dimension of the intermediate area 46 in the thickness direction Z is larger than the dimension T1 of the high density area 44 in the thickness direction Z and smaller than the dimension T2 of the low density area 45 in the thickness direction Z. In addition, the intermediate region 46 has the largest dimension in the thickness direction Z at the portion adjacent to the low density region 45, and the dimension in the thickness direction Z gradually decreases as the distance from the portion adjacent to the low density region 45 increases. Is formed. The density of the intermediate region 46 is smaller than the density of the high-density region 44 and larger than the density of the low-density region 45, and is formed so that the density gradually increases from the inside toward the outside with respect to the intersection O in the vertical and horizontal directions. It is.

A part of the process of manufacturing the second absorption layer 41 is as follows. FIG. 9 is a partial perspective view showing a deboss press process 60 that is a part of the manufacturing process of the second absorbent layer 41. In the drawing, MD indicates a machine direction, CD indicates a cross direction orthogonal to the machine direction MD, and VD indicates a vertical direction orthogonal to the machine direction MD and the cross direction CD, respectively. The machine direction MD corresponds to the vertical direction Y, the cross direction CD corresponds to the horizontal direction X, and the vertical direction VD corresponds to the thickness direction Z.

The debossing press step 60 includes a conveying means 62 including a conveyor belt 61 that conveys the second absorbent layer 41 in the machine direction MD, and a compressing means that compresses the high-density region 44 in the vertical direction (thickness direction) VD. 63. The second absorbent layer 41 placed on the conveyor belt 61 is formed by covering the second absorbent core 42 formed by mixing the hydrophilic fibers 19 and the absorbent polymer particles 18 with the wrapping sheet 23, and is substantially uniform. It is formed to the required thickness. In the second absorbent layer 41 in this state, the density of the hydrophilic fibers 19 and the absorbent polymer particles 18 is substantially uniform in the vertical and horizontal directions. The compression means 63 has rotating

shafts

64a and 65a parallel to each other, and is arranged at the upper side in FIG. 9 and arranged at the lower side with a cylindrical first drum 64 that can rotate around the first rotating shaft 64a. The cylindrical second drum 65 is rotatable about the second rotation shaft 65a. Between the first drum 64 and the second drum 65, there is formed a clearance 66 formed by arranging the

drums

64 and 65 so that their peripheral surfaces are larger than 0 and separated by 1.2 mm or less. is there.

The peripheral surface 64z of the first drum 64 is connected to the concave portion 64b that is recessed from the peripheral surface 64z toward the rotation shaft 64a and the peripheral surface of the concave portion 64b so that the peripheral surface 64z and the surface of the concave portion 64b are inclined. The part 64c and the compression part 64d formed in the site | part except the recessed part 64b and the connection part 64c in the surrounding surface 64z are provided. The concave portion 64 b is formed on the peripheral surface 64 z of the first drum 64 so as to correspond to the low density region 45, and the linkage portion 64 c is formed on the peripheral surface 64 z of the first drum 64 so as to correspond to the intermediate region 46. It is.
The compression part 64d is formed by an emboss 64e corresponding to the compressed recess 54 and a deboss 64f corresponding to the protruding

walls

51 and 52.

When the second absorbent layer 41 having an apparent dimension of about 10 to 30 mm in the vertical direction VD is passed through the clearance 66 between the first drum 64 and the second drum 65, the second absorbent layer 41 is The low-density region 45 is formed by the concave portion 64b of the first drum 64 and the peripheral surface of the second drum 65, and is compressed in the vertical direction VD. The link portion 64c of the first drum 64 and the periphery of the second drum 65 The intermediate region 46 is formed by the surface, and the high-density region 44 is formed by the compression portion 64 d of the first drum 64 and the peripheral surface of the second drum 65.

During this compression, the largest compressive force is applied to form the high-density region 44 having the smallest dimension in the thickness direction Z, while the smallest compressive force is applied to the dimension in the thickness direction Z. The low density region 45 having the largest is formed. While the density of the hydrophilic fibers 19 and the absorbent polymer particles 18 in the high density region 44 is relatively high based on the magnitude of the compressive force applied in this way, the hydrophilic fibers 19 and the absorbent polymer in the low density region 45 are high. The density of the particles 18 is low. When the density of the hydrophilic fiber 19 is high, the diffusion rate of excreta is improved. On the other hand, when the density of the absorbent polymer particles 18 and the hydrophilic fibers 19 is low, although depending on the degree, the diffusion rate of the excrement decreases, but the capacity of the excrement that can be absorbed and retained increases.

As shown in FIGS. 1 and 2, the second absorption layer 41 formed in this manner includes the first absorption layer 21 so that the

non-existing regions

25 a and 25 b overlap the low-density region 45. It is laminated on the absorption layer 41.

According to the liquid absorption pad 1 according to the present invention, a large amount of excrement can be absorbed and retained by the absorbent polymer particles in the existence region 21 of the first absorption layer 21. Moreover, the first absorption is performed so that the non-existing region 25 and the low-density region 45 overlap even if the excrement causes gel block to occur in the existing region 21 and the excrement cannot be absorbed and held in the existing region 21. Since the layer 21 is laminated on the second absorption layer 41, excrement that has passed through the non-existing region 25 can be absorbed and held in the low-density region 45. Moreover, since the low density region 45 and the high density region 44 are connected via the hydrophilic fiber 19, excrement in the low density region can be diffused in the high density region. Therefore, in the 2b absorption layer, the area in which excrement can be absorbed and held can be widened, and excrement can be absorbed and held in the entire second absorption layer.

In addition, the second absorbent layer 41 in which the dimension in the thickness direction Z is substantially uniform and the density of the hydrophilic fibers 19 and the absorbent polymer particles 18 in the longitudinal and transverse directions is substantially uniform is formed in the thickness direction Z of the high-density region 44. Is formed by compressing in the thickness direction Z such that the size of the hydrophilic fiber 19 is smaller than the size of the low density region 45 in the thickness direction. The absorption layer 41 can be easily formed.

As shown in FIGS. 1 and 2, the non-existing region 25 and a part of the high-density region 44 overlap in the central portion in the vertical direction Y, and the non-existing region 25 and a part of the low-density region 45 overlap. Since the 1st absorption layer 21 is laminated on the 2nd absorption layer 41 so that it may overlap, when excrement is discharged to the central part of the lengthwise direction Y, excrement which permeate | transmitted the non-existence area | region 25, It is possible to diffuse in the high density region 44 while absorbing and holding in the low density region 45.

In addition, at both edge portions in the longitudinal direction Y, the dimension X1 in the lateral direction X of the low density region 45 is smaller than the dimension X2 in the lateral direction X of the center existence region 24a, and the longitudinal direction Y of the low density region 45 Is smaller than the dimension Y2 in the longitudinal direction Y of the central existence area 24a. In the longitudinal direction Y, both end edges 27 of the central existence area 24a protrude from the low area end edges 45a of the low density area 45. In the thickness direction Z, the skin facing surface of the low region both-ends edge 45a is covered with both-ends edge 27 (see FIG. 1). Therefore, even if a force in the thickness direction Z is applied to the low-region both-ends edge 45a in a state where a large amount of excrement is absorbed and held at the low-region both-ends 45a, the absorbent polymer particles 18 at the both-ends 27 are applied. By this, it is possible to absorb and hold excrement flowing toward the skin-facing surface from the low-region both-ends edge 45a, and therefore it is possible to prevent the excrement from returning to the wearer's skin. Therefore, since it can suppress that the skin opposing surface side gets wet with excrement, it can suppress that a wearer's skin gets steamed or rashed.

Since the high-density region 44 is arranged so as to extend in the vertical direction Y in the central portion in the vertical direction Y, excrement can be diffused in the vertical direction Y, and is absorbed and held in the central portion in the vertical direction Y. Saturation of excreta that can be suppressed can be suppressed. Therefore, even if excrement is discharged several times, it is possible to absorb and retain these excrement. Further, since the capacity capable of substantially absorbing and holding excrement can be made closer to the capacity capable of absorbing and holding excrement, the capacity of excrement capable of absorbing and holding can be further increased. Can be increased.

Furthermore, in the high density region 44, a compressed concave portion 54 formed by compressing in the thickness direction Z is formed on the skin facing surface, and the portion where the compressed concave portion 54 is formed is particularly hydrophilic in the high density region 44. Since it is a site | part with the high density of the property fiber 19, the diffusion rate of the excrement in the 2nd absorption layer 41 can be improved, and excrement can be diffused further. In addition, the pressing recessed part 54 does not necessarily need to be provided. For example, the pressing recess 54 may not be provided, and the entire area of the skin facing surface of the second absorbent layer 41 may be brought into contact with the non-skin facing surface of the first absorbent layer 21 to increase the area in contact with each other.

In addition, since the first absorbent layer 21 is preferably formed of absorbent polymer particles and the wrapping sheet 23 without containing hydrophilic fibers, once the first absorbent layer 21 has excreted matter. Even if a force is applied in the direction of compression in the thickness direction Z while absorbing and holding, it is possible to suppress excrement from returning to the skin facing surface.

Second Embodiment
FIG. 10 is a plan view of the liquid absorption pad 100 according to the second embodiment of the present invention. Since the basic configuration of this embodiment is the same as that of the first embodiment, only differences will be described below. Moreover, in FIG. 10, the surface sheet 2 is shown with the virtual line.

Referring to FIG. 10, the shape of the central existence region 124a and the first and second

side existence regions

124b and 124c of the first absorption layer 21 is elongated with a small size in the horizontal direction X and a large size in the vertical direction Y. It is formed in a rectangular shape.

In the low density region 145 of the second absorption layer 41, the intersection of the short axis and the long axis corresponds to the center O, the short axis corresponds to the virtual horizontal center line Q, and the long axis corresponds to the virtual vertical center line P. It is formed in the shape of a corresponding elongated ellipse. The intermediate region 146 is formed at the periphery of the low density region 145 so that the width is constant. The high density region 145 is formed at the periphery of the intermediate region 146.

The low-density region 145 has a widest portion 148 in which the dimension in the horizontal direction X increases at the central portion in the vertical direction Y, while the narrow width in which the size in the horizontal direction X decreases at the low region end edges 145a in the vertical direction Y. Part 149.

Also in this liquid absorption pad 100, the first absorption layer 21 is laminated on the second absorption layer 41 so that the non-existing region 25 and a part of the low density region 145 overlap at the center in the vertical direction Y. . Therefore, in the 2nd absorption layer 41, the area which can absorb and hold excretion can be enlarged, and excrement can be absorbed and held in the 2nd absorption layer whole.

<Third Embodiment>
FIG. 11 is a plan view showing a liquid absorption pad according to a third embodiment of the present invention, and FIG. 12 is a cross-sectional view taken along line XII-XII in FIG.
Since the basic configuration of the present embodiment is also the same as that of the first embodiment, only differences will be described below.
Referring to FIGS. 11 and 12, the liquid absorbing pad 200 is formed by pressing grooves 201 provided on the skin facing surface instead of joining the first absorbent layer 21 and the second absorbent layer 41 with a hot melt adhesive. 1 absorption layer 21 and 2nd absorption layer 41 are joined.
The compressed groove 201 is recessed from the top sheet 2 toward the back sheet 3 in the thickness direction Z, and compresses a part of the first absorbent layer 21 and a part of the second absorbent layer 41 in the thickness direction Z. It is formed by that. More specifically, the dimension of the compressed groove 201 in the thickness direction Z is larger than the dimension of the first absorbent layer 21 in the thickness direction Z, reaches the inside of the second absorbent layer 41, and is a low density region. The intermediate region 246 between 45 and the high density region 44 is compressed. The compressed groove 201 is located in the non-existing region 25 in the first absorbent layer 21, and is located in the intermediate region 246 in the second absorbent layer 41. By compressing in the thickness direction Z, the density of the hydrophilic fibers 19 in the intermediate region 246 becomes higher than the density of the hydrophilic fibers 19 in the high-density region 44. A pair of the compressed grooves 201 extends in the vertical direction Y and is symmetrical with respect to the virtual vertical center line P. More specifically, the pair of squeezing grooves 201 are formed so as to be closest to each other on the virtual lateral center line Q in the lateral direction X and gradually away from each other as the distance from the virtual lateral center line Q increases. is there.

According to the liquid absorbent pad 200, the compressed groove 201 for compressing the intermediate region 246 in the thickness direction Z is provided, and the first absorbent layer 21 and the second absorbent layer 41 are joined by the compressed groove 201. Therefore, it is not necessary to provide a hot melt adhesive between these

absorption layers

21 and 41. In addition, since the compressed region 201 compresses the intermediate region 246 in the thickness direction Z to reduce the size, the speed of excrement diffusion in the longitudinal direction Y can be improved.

In addition, the liquid absorption pad 1,100,200 can be changed suitably in the range of this invention, and is not limited to embodiment mentioned above. For example, the present invention is not limited to the liquid-absorbing

pad

1, 100, 200, and can also be applied to absorbent articles such as panty liners, sanitary napkins, light incontinence pads, and disposable diapers.
In the above-described embodiment, the liquid-absorbing structure 10 having the two

absorption layers

21 and 41 has been described. However, in the present invention, the liquid absorbing structure 10 having two or more absorption layers may be used.
Furthermore, 40 mass% or less hydrophilic fiber may be added to the absorbent polymer particles in the

existence regions

24 and 124 of the first absorbent layer 21. Moreover, the non-existence area | region 25 of the 1st absorption layer 21 may also contain the small amount of absorbent polymer particle which may be mixed in the process of manufacturing an absorbent article. That is, the absorbent polymer particles may be included to such an extent that no gel block is generated when excrement is permeated in the non-existing region 25. In other words, the non-existing regions 25 and 125 may be formed so as not to substantially contain the absorbent polymer particles. Furthermore, in order to maintain the shape and improve the liquid absorbency, the first absorbent core 22 and the second absorbent core 42 may optionally include, for example, 5 to 25% by mass of a thermoplastic synthetic fiber (such as staple fiber). May be added. There is no need to provide a plurality of

existence areas

24 and 124, and only the

central existence areas

24a and 124a may be provided. In the above-described embodiment, the low density region 45 is compressed in the thickness direction Z. However, the low density region 45 is not necessarily formed by being compressed. In addition, the example in which the

regions

44 and 45 having different densities of the hydrophilic fibers 19 are formed by changing the compressive force applied to the low density region 45 and the high density region 44 has been described. The method of forming is not limited to the method described above. Further, the intermediate region 46 is not necessarily provided. For the members constituting the absorbent article, unless otherwise specified, in addition to the materials described in the present specification, known materials that are commonly used in this type of field may be used without limitation. it can. As used herein, the terms “first” and “second” are used merely to distinguish similar elements, positions, etc.

1 Liquid absorption pad (absorbent article)
2 Top sheet 3 Back sheet 10 Absorbent structure 21 1st absorption layer 24 Existence area 25 Non-existence area 26 Central part 41 2nd absorption layer 44 High density area 45 Low density area X Horizontal direction Y Vertical direction Z Thickness Direction P Virtual vertical center line Q Virtual horizontal center line

Claims

The skin sheet has a skin facing surface and a non-skin facing surface, and is interposed between the top sheet positioned on the skin facing surface side, the back sheet positioned on the non-skin facing surface side, and the top sheet and the back sheet. In an absorbent article comprising a liquid absorbing structure,
The liquid-absorbent structure includes at least two first and second absorbent layers that overlap each other;
The first absorbent layer is disposed on the skin-facing surface side and has an existing region where the absorbent polymer particles are present and a non-existing region where the absorbent polymer particles are not substantially present;
The second absorbent layer is disposed on the non-skin facing surface side, has a hydrophilic fiber and an absorbent polymer particle, and has a high density region in which the density of the hydrophilic fiber is high, and the density of the hydrophilic fiber. Having a low low density region,
The first absorbent layer is laminated on the second absorbent layer so that the non-existing region and a part of the low-density region overlap, and the low-density region and the high-density region form the hydrophilic fiber. The said absorbent article characterized by being connected through.
The liquid absorbing structure has a lateral direction, a longitudinal direction, and a thickness direction,
The high density region is formed by compressing in the thickness direction so that a dimension in the thickness direction is smaller than a dimension in the thickness direction of the low density region. Absorbent article.
The existence area is formed in an elongated shape longer in the vertical direction than the horizontal direction, while the non-existence area is formed so as to be adjacent to both sides in the horizontal direction of the existence area,
In the central portion in the vertical direction, the first absorption layer is laminated on the second absorption layer so that a part of the high density region and a part of the low density region overlap with the non-existing region, respectively. The absorbent article according to claim 1 or 2.
The existence area has at least a central existence area arranged in the central portion in the lateral direction,
At both edge portions in the longitudinal direction, the lateral dimension of the low density region is smaller than the lateral dimension of the central existence region, and the longitudinal dimension of the low density region is the central existence region. Smaller than the vertical dimension, and the center existing region extends beyond the low-density region at both end edges in the vertical direction, and both end edges in the vertical direction of the low-density region in the thickness direction. The absorbent article according to any one of claims 1 to 3, wherein the skin-facing surface is coated with the central region.
The absorbent article according to claim 4, wherein the low-density region extends in the lateral direction from the central existence region at a central portion in the longitudinal direction.
The length of the portion where the low-density region extends from the central existence region in the horizontal direction is the largest in the central portion in the vertical direction and gradually decreases as the distance from the central portion increases. Absorbent article.
In the presence area, in addition to the central existence area, at least two side existence areas are provided so as to be arranged in the lateral direction on both sides of the central existence area, and the side existence area overlaps the high density area. Item 7. The absorbent article according to any one of Items 4 to 6.
The center existing region has the narrowest width portion where the horizontal dimension becomes the smallest at the central portion in the vertical direction, while the widest portion where the horizontal dimension becomes the largest at both end edges in the vertical direction. Have
The side-existing region has a widest portion having the largest horizontal dimension at the central portion in the vertical direction, and has a narrowest portion having the smallest horizontal dimension at both end portions in the vertical direction. Item 8. An absorbent article according to Item 7.
The low-density region has the widest portion where the horizontal dimension becomes large at the central portion in the vertical direction, and has the narrowest width portion where the horizontal dimension becomes small at both edge portions in the vertical direction. The absorbent article according to any one of claims 1 to 8.
10. The absorbent article according to claim 9, wherein the center existence area and the side existence area each have a substantially rectangular shape extending in the longitudinal direction so that the width in the lateral direction is substantially constant.