JP6108522B2 - Absorber and absorbent article - Google Patents

Description

  The present invention relates to an absorbent body and an absorbent article using the same.

  As a liquid-retaining absorbent used for absorbent articles such as disposable diapers and absorbent pads, an absorbent core containing an absorbent material such as wood pulp and a water absorbent polymer, and a core wrap sheet covering the absorbent core, What is comprised including is known. The core wrap sheet plays a role of improving the shape retention of the absorbent body and preventing the absorbent material from leaking out of the absorbent body. Conventionally, water-permeable sheets such as thin paper and nonwoven fabric are used as the core wrap sheet.

In recent years, it has been proposed that an absorbent core is provided with a portion where no absorbent material is present or a portion where the abundance is small, and the absorbent core is divided into a plurality of small absorbent portions. For example, the absorbent core described in Patent Document 1 has a relatively low basis weight in which a plurality of relatively high basis weight portions corresponding to the small absorbent portions are located in a gap between two adjacent small absorbent portions. Each block is divided into individual blocks.
Patent Document 2 discloses a first region having a high content ratio of the polymer absorber and a low content ratio of hydrophilic fibers, and a content ratio of the polymer absorber lower than that of the first region and containing hydrophilic fibers. An absorbent article having an absorbent body having a groove-like space penetrating from the second region side to the inside of the first region is described.
Patent Document 3 describes an absorbent body in which a plurality of absorbent portions are separated from each other and joined to a base sheet.

WO2012 / 086265A1 JP 2009-119154 A JP 2011-135922 A

The conventional block-type absorbent core is advantageous in that it is more flexible than the flat-type absorbent core having a uniform basis weight and can fit well to the undulations on the skin surface. However, on the other hand, when external force is applied, the small absorbent parts are divided and the shape is easily broken, so that, for example, a large amount of absorbent material is concentrated in one place of the absorbent body and the wearer of the absorbent article feels uncomfortable. May cause inconveniences such as giving the absorption performance and the absorption performance as designed cannot be obtained. The absorber of patent document 2 is also the same.
Patent Document 3 describes that a plurality of absorbing portions are fixed to a base sheet, but the base sheet is a core wrap sheet that covers the absorbent core or damages the core wrap sheet. There is no description about the device for fixing the absorbing portion while preventing the above.

  The subject of this invention is providing the absorber and absorbent article which can eliminate the fault which the prior art mentioned above has.

  The present invention is an absorbent body comprising an absorbent core and a core wrap sheet sandwiching the absorbent core, wherein the absorbent core includes a pulp fiber layer containing pulp fibers and no water-absorbing polymer, and pulp fibers. And a mixed layer containing a water-absorbing polymer is formed continuously in the thickness direction, and the absorbent core is formed on the surface on the pulp fiber layer side by a linear recess and the linear recess. It has a plurality of small absorbent parts formed by partitioning into a plurality of regions, the small absorbent part has a higher basis weight than the bottom of the linear recess, and the mixed layer is A fitting recess that is continuous in the planar direction through the bottom of the linear recess and is recessed in the small absorbent portion from the surface on the pulp fiber layer side, which is smaller than the small absorbent portion, toward the mixed layer side. And the core wrap sheet is inserted into each of the fitting recesses. Are, there is provided an absorber.

According to the absorbent body of the present invention, the structure of the absorbent core is stable even after liquid absorption while having a block-type absorbent core. Damage is unlikely to occur. Therefore, the absorbent body of the present invention is excellent in flexibility, feel during liquid absorption, absorption performance, and the like.
Moreover, since the absorbent article of this invention comprises the absorber, it is excellent in the fitting property to a wearer's skin, the wearing feeling in a liquid absorption state, absorption performance, etc.

FIG. 1 is a view showing an embodiment of the absorbent article of the present invention, and is a plan view schematically showing a partially broken state in which the elastic member of each part is expanded and expanded in a planar shape. 2 is a cross-sectional view schematically showing a cross section taken along line II of the absorbent body used in the absorbent article of FIG. FIG. 3A is a plan view showing a surface of the absorbent body used in the absorbent article of FIG. 1 on the side having the indented portion that is indented into the fitting concave portion, and FIG. It is a top view which shows the arrangement pattern of the linear recessed part formed in the surface at the side of the pulp fiber layer of an absorptive core. FIG. 4 is an explanatory view of a preferred form of forming the fitting recess. FIG. 5 is an explanatory view of another preferable formation mode of the fitting recess. FIG. 6 is a schematic view showing another preferred embodiment of the present invention. FIG. 7 is a schematic view showing an absorbent body manufacturing apparatus preferably used for manufacturing the absorbent body used in the absorbent article of FIG. FIG. 8 is a schematic view showing a cross section along the drum axis direction of the concave portion for accumulation of the fiber stacking apparatus shown in FIG. FIG. 9 is a schematic view showing a state in which a material for forming an absorbent core is deposited in the recesses for accumulation shown in FIG.

Hereinafter, the absorbent body and absorbent article of the present invention will be described based on a preferred embodiment thereof with reference to the drawings.
A disposable diaper 1 which is an embodiment of the absorbent article of the present invention includes a liquid-permeable surface sheet 2 that forms a skin-facing surface, a liquid-impermeable or water-repellent material that forms a non-skin-facing surface (hereinafter referred to as these). A back sheet 3 (collectively referred to as liquid impervious) and an absorbent body 4 disposed between both sheets 2 and 3 are provided. The diaper 1 has a vertically long shape in one direction X shown in FIG. The absorbent body 4 of the diaper 1 is an embodiment of the absorbent body of the present invention.
Each of the top sheet 2, the back sheet 3, and the absorber 4 has a vertically long shape that is long in one direction X. Each of the top sheet 2 and the back sheet 3 has a size larger than that of the absorber 4, and extends outward from the peripheral edge of the absorber 4. The surface sheet 2 has a width direction Y dimension that is smaller than the width direction Y dimension of the back sheet 3.

  As shown in FIG. 1, the diaper 1 has, in the longitudinal direction X, a back side portion A disposed on the back side of the wearer at the time of wearing, and a ventral side portion B disposed on the abdomen side of the wearer at the time of wearing, And a crotch part C disposed on the inseam of the wearer when worn. The crotch part C includes an excretion part facing part that is disposed so as to face the wearer's excretion part when worn, and is located at the central part in the longitudinal direction X of the diaper 1. As shown in FIG. 1, the diaper 1 has a rectangular shape in which the central portion in the longitudinal direction X is confined in a plan view.

  In the present specification, the longitudinal direction (X direction in the figure) is a direction that coincides with the wearer's front-rear direction when the absorbent article is worn or a constituent member of the absorbent article (surface sheet 2, absorbent core 40, core wrap). Sheet 5A, 5B, etc.) corresponding to this direction, and the width direction (Y direction in the figure) is a direction orthogonal to the longitudinal direction. Further, the skin facing surface is a surface of the absorbent article or a component thereof that is directed to the wearer's skin when the absorbent article is worn, and the non-skin facing surface is an absorption in the absorbent article or a component thereof. It is a surface that is directed to the side opposite to the skin side (clothing side) when wearing the property article.

  The diaper 1 is a so-called unfolded disposable diaper, and a pair of fastening tapes 7 and 7 are provided on both side edges along the longitudinal direction X of the back side A, and the non-skin of the abdominal side B of the diaper 1 On the opposite surface, a to-be-attached region 8 for fastening the fastening portion 71 of the fastening tape 7 is formed. The fastening part 71 and the to-be-attached area | region 8 are comprised using the male member, the female member, etc. of a mechanical surface fastener. Moreover, the side sheet | seat 6 to which the elastic member 61 is being fixed in the expansion | extension state by one side edge part is distribute | arranged to each both sides along the longitudinal direction X of the diaper 1, and a pair of crotch part C at the time of wear is a pair. A three-dimensional gather is formed. In addition, elastic members 62 are arranged along the longitudinal direction X on the left and right leg portions arranged around the wearer's legs, and the pair of legs when worn is contracted by the elastic members 62. Leg gathers are formed. The pair of side sheets 6 and 6, the top sheet 2, the absorber 4, the elastic members 61 and 62, the back sheet 3, and the like are integrated by a known joining means such as a hot melt adhesive.

  As shown in FIGS. 1 and 2, the absorbent body 4 of the diaper 1 includes an absorbent core 40 and core wrap sheets 5A and 5B sandwiching the absorbent core 40. The absorbent core 40 contains an absorbent material such as a fiber material or a water-absorbing polymer, and has a thin plate shape that is long in one direction (longitudinal direction X of the diaper 1) as shown in FIG. Is enclosed.

  As shown in FIG. 2, the absorbent core 40 includes a pulp fiber layer 44 that includes pulp fibers and does not include a water-absorbing polymer, and a mixed layer 45 that includes pulp fibers and a water-absorbing polymer. Has been. In the present embodiment, the pulp fiber layer 44 forms one surface 40 b that becomes the non-skin facing surface of the absorbent core 40, and the mixed layer 45 forms one surface 40 a that becomes the skin facing surface of the absorbent core 40. Yes.

The pulp fiber layer 44 includes pulp fibers and does not include a water absorbent polymer. As will be described later, the absorbent core 40 has one surface 40b composed of a pulp fiber layer 44 that does not contain a water-absorbing polymer. When forming the fitting recess 47 by embossing the laminated body from the core wrap sheet 5B side, the pulp fiber layer 44 can function as a cushioning material, and the core wrap sheet 5B is torn. Or the water-absorbing polymer 46 in the mixed layer 45 is prevented from being destroyed by pressurization.
Having the pulp fiber layer 44 means that the water-absorbing polymer 46 is not exposed from the pulp fiber layer 44 side even when the liquid is absorbed by the absorbent core 40 and the water-absorbing polymer 46 swells.
On the other hand, the mixed layer 45 contains pulp fibers and a water-absorbing polymer, and preferably contains both in a mixed state.
The mass ratio of the pulp fiber and the water-absorbing polymer in the mixed layer 45 (pulp fiber mass / water-absorbing polymer mass) is preferably 0.4 or more, more preferably 0.5 or more, and preferably It is 1.5 or less, more preferably 1.2 or less, preferably 0.4 or more and 1.5 or less, more preferably 0.5 or more and 1.2 or less.

  Examples of the pulp fibers contained in the absorbent core 40 include cellulose fibers of wood pulp such as softwood bleached kraft pulp (NBKP) and hardwood bleached kraft pulp (LBKP), and cellulose fibers of non-wood pulp such as cotton pulp and straw pulp. It is done. Cellulose fibers may be natural fibers or regenerated fibers such as rayon and cupra. These pulp fibers can be used singly or in combination of two or more.

  As the water-absorbing polymer contained in the absorbent core 40, various polymers conventionally used in the technical field can be used. For example, polyacrylic acid soda, (acrylic acid-vinyl alcohol) copolymer, poly Cross-linked sodium acrylate, (starch-acrylic acid) graft polymer, (isobutylene-maleic anhydride) copolymer and saponified product thereof, potassium polyacrylate, cesium polyacrylate, etc., and one of these Can be used alone or in admixture of two or more. As the water absorbing polymer, a particulate polymer is usually used. The particulate water-absorbing polymer includes an amorphous type, a block type, a bowl type, a spherical particle agglomeration type, a spherical type and the like due to the difference in shape, and any type can be used.

The pulp fiber layer 44 and the mixed layer 45 of the absorbent core 40 may contain fiber materials other than pulp fibers. Examples of fiber materials other than pulp fibers include synthetic fibers having a hydrophilic surface. Synthetic fibers having a hydrophilic surface include hydrophilic synthetic fibers such as polyvinyl alcohol fibers and polyacrylonitrile fibers; synthetic fibers such as PET fibers, PE fibers, PP fibers, and polyester fibers that are hydrophilized with a surfactant, etc. Is mentioned.
The pulp fiber layer 44 and the mixed layer 45 of the absorbent core 40 can be used by mixing two or more kinds of pulp fibers and other fiber materials.

The proportion of the pulp fibers in the total fiber material in the pulp fiber layer 44 is preferably 70% by mass or more, more preferably 80% by mass or more, and further preferably 100% by mass.
The total content of the pulp fiber and the water-absorbing polymer in the absorbent core 40 is preferably 70% by mass or more, more preferably 85% by mass or more, and further preferably 100% by mass.

  As described above, the pulp fiber layer 44 and the mixed layer 45 are continuously formed in the thickness direction of the absorbent core 40. Here, “continuously formed” is different from the case where members manufactured separately are bonded with an adhesive or other joining means, and the pulp fiber layer 44 and the mixed layer 45 are sequentially laminated, Shows a state where there is no clear boundary. When the pulp fiber layer 44 and the mixed layer 45 are continuously formed, the water-absorbing polymer 46 is not easily spilled from the interlayer, and the absorbed liquid has continuity that can move smoothly. The absorbent core 40 in which the pulp fiber layer 44 and the mixed layer 45 are continuously formed can be manufactured by a manufacturing method described later.

Moreover, as shown in FIG.2 and FIG.3 (b), as for the absorptive core 40, in the surface 40b at the side of the pulp fiber layer 44 which forms a non-skin opposing surface, linear recessed part 41 (41A-41E), and this The absorbent core 40 has a plurality of small absorbent portions 43 (43A to 43C) formed by dividing the absorbent core 40 into a plurality of regions by the linear concave portions 41 (41A to 41E). Each of the linear concave portions 41 (41A to 41E) extends linearly in the planar direction of the absorbent core 40, and the absorbent core 40 has two or more types of linear concave portions 41 having different extending directions. doing.
The surface 40b on the pulp fiber layer 44 side of the absorbent core 40 is an uneven surface on which the linear recess 41 is formed, whereas the surface 40a on the mixed layer 45 side of the absorbent core 40 is a line. A concave surface is not formed, and the surface is substantially flat.

  The formation aspect of the linear recess 41 (41A to 41E) of the absorbent core shown in FIG. 3 will be described more specifically. One end side in the longitudinal direction X of the absorbent core 40 (the back side portion A is disposed). On the end in the longitudinal direction, linear recesses 41A and 41B extending in the direction intersecting both the longitudinal direction X and the width direction Y are formed so as to intersect with each other. Is formed. Moreover, the linear shape extended in the direction which cross | intersects both the longitudinal direction X and the width direction Y at the other end part side (longitudinal end part side distribute | arranged to the stomach side part B) of the longitudinal direction X of the absorptive core 40. The recesses 41C and 41D are formed so as to intersect with each other, thereby forming recesses in a lattice shape in plan view. In addition, a pair of linear recesses 41E extending in the longitudinal direction X is formed in a longitudinal center portion (region disposed in the crotch portion C) of the absorbent core 40 sandwiched between the one end portion and the other end portion. 41E is formed. These linear recesses 41 </ b> A to 41 </ b> E are connected to each other, and are formed continuously in one surface 40 b as the entire recess 41. And in the one end part and other end part of the longitudinal direction X of the absorptive core 40, square-shaped small absorption part 43A, 43B is formed in the part of the grid | lattice of the recessed part 41 formed in the grid | lattice form, respectively. In addition, in the central portion of the longitudinal direction X, a vertically long small absorbent portion 43C that is long in the longitudinal direction X of the absorbent core 40 is formed.

  The small absorbent portions 43 (43A to 43C) have a higher basis weight than the bottom portion 42 of the concave portion 41, and more absorbent materials such as fiber materials and water absorbent polymers exist than the bottom portion 42 of the concave portion 41. It is a part. In the present embodiment, the small absorbing portion 43 has a higher basis weight than the bottom portion 42 of the recess 41, and further has a higher density than the bottom portion 42 of the recess 41. Further, the small absorption portion 43 has a higher area ratio than the bottom portion 42 of the recess 41. The area ratio is a ratio of the area of the bottom portion 42 of the recess 41 or the area of the small absorbent portion 43 to the unit area of the one surface 40b of the absorbent core 40. As will be described later, the absorbent core 40 is manufactured by obtaining a stacked body of absorbent material using a stacking apparatus and compressing the entire stacked body in the thickness direction. As for the fine body, the part corresponding to the small absorption part 43 has a larger amount of absorbent material than the part corresponding to the bottom part 42 of the recess 41. That is, the concave portion 41 of the absorbent core 40 is formed by previously reducing the amount of absorbent material stacked from other parts, and the absorbent material of a part of the stacked body (recessed portion formation planned portion). It is not formed by scraping or removing the surface or compressing a part of the piled body (recessed portion formation planned portion).

  In addition, the mixed layer 45 of the absorbent core 40 is continuous in the planar direction via the bottom 42 of the linear recess 41 as shown in FIG. Here, “continuous in the plane direction” means that the pulp fiber layer 44 and the mixed layer 45 are sequentially laminated, which is different from the case where the members manufactured separately are bonded with an adhesive or other joining means. The state which does not have an intermittent part also in a plane direction is shown. Therefore, for example, there is no gap between members that occurs when two separately manufactured absorbent cores are arranged side by side at the boundary between the small absorbent portion 43 and the bottom 42 of the recess. When the mixed layer 45 is continuous in the plane direction via the bottom 42 of the linear recess 41, the water-absorbing polymer 46 is less likely to spill from between the members, and the absorbed liquid has continuity that can move smoothly. It becomes like this. The absorbent core 40 in which the mixed layer 45 is continuous in the planar direction via the bottom 42 of the linear recess 41 can be manufactured by a manufacturing method described later.

Further, as shown in FIG. 2, a fitting recess 47 that is recessed from the pulp fiber layer side surface 40b toward the mixed layer 45 side is formed in the small absorbent portion 43 of the absorbent core 40 having the configuration described above. Each of the fitting recesses 47 has an indented portion 51 into which a part of the core wrap sheet 5B is indented.
The fitting recessed portion 47 of the small absorbent portion 43 and the recessed portion 51 of the core wrap sheet 5B that is recessed into the fitting recessed portion 47 are made of absorbent material manufactured using a fiber stacking device as described in the manufacturing method described later. It is formed by stacking the core wrap sheet 5B on the surface on the pulp fiber layer side of the laminated fiber, and embossing the laminated body from the core wrap sheet 5 side.
In FIG. 3 (a), the portion of the core wrap sheet 5B that has been pressed by embossing is shown as a small circle, and those small circles that overlap with the small absorbing portion 43 are small. This is an indented portion 51 that is indented into the fitting recess 47 formed in the absorbing portion 43.

Incidentally, Recessed in join the club 51 is in a state that has entered the core wrap sheet 5B is in a form to enter the fitting recess 47 formed in the absorbent core 40, it is preferably the peel strength measured by the method described below 8 cN / 70 mm or more More preferably 10 cN / 70 mm or more, preferably 50 cN / 70 mm or less, more preferably 30 cN / 70 mm or less, and preferably 8 to 50 cN / 70 mm, more preferably 10 to 30 cN / 70 mm. .

As shown in FIGS. 1 and 2, the core wrap sheet 5 </ b> A covers substantially the entire surface 40 a that forms the skin-facing surface of the absorbent core 40. The core wrap sheet 5 </ b> B covers substantially the entire other surface 40 b of the absorbent core 40, and the extended portions extending outward in the width direction Y from both side edge portions of the absorbent core 40 are the absorbent core 40. wound on one surface 40 a side of, and is overlaid on both sides of the core wrap sheets 5A. Between the core wrap sheet 5A and the absorbent core 40, and between the core wrap sheet 5B and the absorbent core 40, the laminated portions of the core wrap sheet 5A and the core wrap sheet 5B are respectively made of a hot-melt adhesive or the like. It may be joined by a known joining means.

  As the core wrap sheets 5A and 5B, various kinds of materials conventionally used for absorbent bodies of absorbent articles can be used without particular limitation, and may be paper or non-woven fabric, or a composite sheet in which paper and non-woven fabric are bonded together. But it ’s okay.

  The core wrap sheets 5A and 5B, which are paper, can be manufactured by a known wet papermaking method. The wet papermaking method has a stock preparation process for preparing a stock (slurry) made of an aqueous dispersion of fibers, and a paper making process for making a fiber web by drawing fibers from the stock and drying them. It is. The paper making process is usually divided into a wire part, a press part, a dryer part, a size press, a calendar part, etc., and is carried out sequentially. The wet papermaking method can be carried out according to a conventional method using a paper machine such as a long paper machine, a twin wire paper machine, an on-top paper machine, a hybrid paper machine, or a round paper machine.

Further, as the core wrap sheets 5A and 5B which are nonwoven fabrics, for example, heat roll nonwoven fabric, air-through nonwoven fabric, airlaid nonwoven fabric, spunlace nonwoven fabric, needle punched nonwoven fabric, spunbond nonwoven fabric, meltblown nonwoven fabric, spunbond-meltblown nonwoven fabric, spunbond- Melt blown-spunbond nonwoven fabric and the like. These nonwoven fabrics may be subjected to a hydrophilic treatment using a hydrophilic agent such as a surfactant.
The core wrap sheet 5A and the core wrap sheet 5B may be the same type of sheet or different types of sheets.

  The disposable diaper 1 of this embodiment can be used similarly to a normal disposable diaper.

  The absorbent body 4 of the present embodiment is excellent in flexibility because it uses a block-type absorbent core 40 having a plurality of small absorbent portions 43 partitioned by linear concave portions 41 as the absorbent core. . Moreover, since the disposable diaper 1 of this embodiment uses such an absorber, this absorber shows the followable deformability excellent with respect to the body shape, for example.

Further, the absorbent body 4 of the present embodiment is formed with a fitting recess 47 on the side of the pulp fiber layer 44 of the small absorbent portion 43 and an indented portion 51 of the core wrap sheet 5B that is intruded into the fitting recess 47. Therefore, the movement of the small absorbent portion 43 is suppressed by the anchor effect, and the structure of the absorbent core is stable before and after liquid absorption. For this reason, it is possible to prevent deterioration of the feel and absorption performance of the absorbent body 4. In addition, when forming the fitting recess 47 and the indented portion 51 that is recessed therein, the pulp fiber layer functions as a cushioning material, and damage to the core-wrap sheet and the water-absorbing polymer in the mixed layer is also prevented. . Therefore, the absorber 4 of this embodiment is excellent also in the touch at the time of liquid absorption, absorption performance, etc.
Moreover, since the disposable diaper 1 of this embodiment is using such an absorber, it is excellent in the fitting property to a wearer's skin, the wearing feeling in a liquid absorption state, absorption performance, etc.

The core wrap sheet 5B preferably has strength when wet. For example, the wet strength measured by the following method is preferably 20 cN / 25 mm or more, more preferably 30 cN / 25 mm or more.
The core wrap sheet 5B has a basis weight of preferably 6 g / m ² or more, more preferably 8 g / m ² or more, and preferably 30 g / m ² or less, more preferably 20 g / m ² or less. Moreover, Preferably it is 6-30 g / m < ² >, More preferably, it is 8-20 g / m < ² >.

<Measurement method of wet strength>
The measurement object sheet is allowed to stand for 12 hours in an environment of a room temperature of 23 ° C. ± 2 ° C. and a relative humidity of 50% RH ± 2% to adjust the humidity so as to be in a constant state. A rectangular shape having a size of 150 mm in the CD (direction intersecting the machine flow direction) and 25 mm in the MD (machine flow direction) is cut out from the moisture-conditioned sheet, and the cut out rectangular shape is used as a sample. This sample is attached to a chuck of a tensile tester (manufactured by Shimadzu Autograph AG-1kN) without tension so that the CD is in the tensile direction. The distance between chucks is 100 mm. With the brush tip of the brush wetted with water, the sample is wetted by applying water to the entire surface of the sample with a width of about 10 mm over the entire length in the tensile direction, and then the sample is pulled at a speed of 300 mm / min. Measure the maximum strength until the sample breaks. When the amount of water adhering to the sample is 5 to 15 mg, an appropriate wet state is obtained as in the case where the entire sample is immersed. Even if it is partially attached to water, it will naturally become moderately wet due to the diffusion of the liquid due to capillary action, so if the amount of liquid is partially attached across the sample measurement direction, it will be measured There was no effect on the results.
The measurement is performed 5 times, and the average value of these is taken as the wet strength of CD.

And in the disposable diaper 1 of this embodiment, the absorptive core 40 contained in the absorber 4 is distribute | arranged so that the surface 40a by the side of the mixed layer 45 may face the surface sheet side of the diaper 1. FIG.
Since the mixed layer 45 is continuous in the planar direction via the bottom 42 of the linear recess, the liquid supplied to the topsheet 2 side is also from a portion overlapping the bottom 42 of the linear recess in the topsheet 2. Then, it is sucked into the absorbent core 40 and diffuses appropriately in the plane direction in the absorbent core 40, so that the liquid can be easily held in the small absorbent portion. Thereby, the diaper 1 becomes the thing excellent in leak prevention property.
On the other hand, in the case where the space between the small absorbent parts is completely divided by the space, in the portion overlapping the space in the top sheet 2, the liquid is inferior from the top sheet to the absorbent core, The liquid supplied on the top sheet 2 may be excessively diffused in the plane direction on the top sheet or in the top sheet to cause problems such as leakage.

Moreover, in the absorber 4 of this embodiment, the some fitting recessed part 47 is formed with respect to one small absorption part 43 of the absorptive core 40, as shown to FIG.2 and FIG.3 (a). The core wrap sheet 5B has indented portions 51 corresponding to the fitting recesses 47, respectively.
By forming a plurality of fitting recesses 47 into which the core wrap sheet 5B is recessed with respect to one small absorbent part 43, the stability of the structure of the absorbent core 40 is further improved.

  Further, when a plurality of fitting recesses 47 are formed with respect to one small absorption part 43, it is possible to disperse and arrange these fitting recesses 47 over a wide range of the small absorption part 43. 43 and the core wrap sheet 5B are excellent in fixability, and are preferable from the viewpoint that the core wrap sheet 5B is less likely to shake than the deeply formed fitting recess. In addition, when a large amount of liquid is supplied, the liquid is also supplied to the linear recess 41. In this case also, the liquid is drawn into the small absorption section 43 from the linear recess 41 around the small absorption section 43. From the viewpoint of improving the property. By improving the drawability of the liquid into the small absorption part 43, the absorber 4 suppresses excessive diffusion and becomes more excellent in leakage prevention properties.

For example, as shown in FIG. 4, the plurality of fitting recesses 47 formed in one small absorption portion 43 have an area S1 inside the annular line L1 that surrounds them and has a minimum length, and has a small absorption. It is preferable that the portion 43 is arranged to be equal to or more than 1/3 of the area S2, and it is more preferable that the area S1 is arranged to be 1/2 or more of the area S2.
In addition, as shown in FIG. 5, the plurality of fitting recesses 47 formed in one small absorption portion 43 have a shape of an annular line L <b> 1 that surrounds them and has a minimum length. It is preferable that they are arranged so as to be similar to the shape in plan view.

In the above-described absorbent core 40, as shown in FIG. 2, the small absorbent portion 43 has a flat front end surface that forms the surface 40b on the pulp fiber layer 44 side. As for an absorptive core, the front end surface of the small absorption part 43 may have comprised the convex curve shape like the absorptive core 40A shown in FIG. Further, the small absorbent portion 43 in the absorbent core 40A shown in FIG. 6 has a top surface 43t and inclined surfaces 43s formed on both sides sandwiching the top portion 43t on the convex curved end surface. The depth d1 of the fitting recess 47t closest to the fitting recess 47t, ie, the top 43t, is greater than the fitting recess 47s near the linear recess 41, ie, the depth d2 of the fitting recess 47s closest to the linear recess 41. deep. The fitting recesses 47t and 47s are formed by overlapping the core wrap sheet on the surface of the pulp fiber layer 44 and pressurizing from the core wrap sheet side, so that the depth is smaller than the fitting recess 47s having a shallow depth. When the deep fitting recess 47t is formed, the degree of compression becomes larger, and the density around the bottom of the fitting recess 47t is higher than the density around the bottom of the fitting recess 47s.
Therefore, the shallow fitting recess 47s has a fixing property even though the core wrap sheet 5B is not easily torn, and is excellent in that the fixing property can be firmly exhibited by the deep fitting recess 47t. Further, since the fitting recess 47t closer to the top is deeper, the drawability of the liquid in the vicinity of the top of the small absorbent portion 43 is improved, and it is easier to influence the core wrap sheet 5A side, making the absorber more efficient. Can be used well.
In addition, the convex-curved tip surface may have an annular inclined surface 43s around the top, or may have inclined surfaces 43s only on both the front and rear sides or both the left and right sides of the top 43t. .

  Moreover, in the absorptive core 40 of embodiment mentioned above, as shown in FIG. 2, although the depth d of the fitting recessed part 47 is less than the thickness t3 of the pulp fiber layer 44, the depth of the fitting recessed part 47 is sufficient. It is also preferable that d be equal to or greater than the thickness t3 of the pulp fiber layer 44. By setting the depth d of the fitting concave portion 47 to be equal to or greater than the thickness t3 of the pulp fiber layer 44, the indented portion 51 of the core wrap sheet 5B can be easily removed from the fitting concave portion 47 only with the pulp fiber layer 44 having flexibility and cushioning properties. However, when the fitting concave portion 47 reaches the mixed layer 45 that is relatively hard compared to the pulp fiber layer 44, it becomes difficult to come out, and the fixability is further improved.

  The ratio (D / t3) between the depth d of the fitting recess 47 and the thickness t3 of the pulp fiber layer 44 is preferably 2 or more, more preferably 3.5 or more, and preferably 15 or less, more preferably Is 10 or less, preferably 2 to 15, more preferably 3 to 10.

Moreover, as above-mentioned, the absorptive core 40 in the absorber 4 of embodiment mentioned above has a shape long in one direction in planar view, and the one end part of the longitudinal direction distribute | arranged to the back side part A of the diaper 1 The other end portion in the longitudinal direction disposed on the ventral side B of the diaper 1 and the central portion disposed on the crotch portion C of the diaper 1 (see FIG. 3). Moreover, the said center part of the absorptive core 40 is narrower than the said one end part and the said other end part.
The depth of the fitting recess 47 of the small absorbing portion 43C formed at the center is deeper than the depth of the fitting recess 47 of the small absorbing portions 43A and 43B formed at the one end and the other end. It has become.

The center part of the absorptive core 40 includes the excretion part opposing part, and there is much quantity of the liquid supplied compared with one end part or the other end part. By making the small absorption part 43C in the center part deeper than the fitting concave part of other parts, it is possible to more effectively prevent the structure of the absorbent core 40 from being broken during liquid absorption.
From such a viewpoint, the depth of the fitting recess 47 of the small absorption portion 43C in the center is the ratio of the small absorption portions 43A and 43B of the one end portion and the other end portion to the depth of the fitting recess (small absorption portion). The depth at 43C / the depth at the small absorbing portions 43A and 43B) is preferably 1 or more, more preferably 1.2 or more, still more preferably 1.4 or more, and preferably 3 or less, more Preferably it is 2 or less, Preferably it is 1-3, More preferably, it is 1.4-2.

In addition, when the area occupied by the fitting recess 47 is too large, the degree of compression of the absorbent core 40 increases, so that the flexibility of the absorbent core 40 is impaired. On the other hand, when the amount is too small, a sufficient effect on the fixing property is not exhibited. For this reason, it is preferable that the area ratio or individual size (area) satisfy | fills the fitting recessed part formed in a small absorption part, and an area ratio and each magnitude | size (area) satisfy the following conditions. It is more preferable.
(Area ratio of fitting recess)
The area ratio of the fitting recess formed in the small absorbent part is preferably 1% or more, more preferably 3% or more, preferably 30% or less, more preferably 20% or less, and preferably 1 to 30%, more preferably 1 to 20%. The area ratio of the fitting recess is obtained by the following formula. Area ratio (%) of the fitting recess = (total area of the fitting recess formed in one small absorption part / area of the small absorption part) × 100
(Size of fitting recess)
The area of each fitting recess formed in the small absorbent part is preferably 0.1% or more, more preferably 0.2% or more, and preferably 10%, relative to the area of the small absorbent part. Hereinafter, it is more preferably 1% or less, and preferably 0.1 to 10%, more preferably 0.2 to 1%.
The area of the fitting recess is preferably 3 mm ² or more, more preferably 12 mm ² or more, preferably 400 mm ² or less, more preferably 300 mm ² or less, and preferably 3 to 400 mm ² . More preferably, it is 12-300 mm < ² >.
Here, the areas of the small absorption part and the fitting recess mean the area when the absorbent body is viewed in plan, and are measured by the following measuring method.
<Measurement method of the area of the small absorption part and the fitting recess>
Place the absorber on the tres table and shoot with a digital camera in the dark. The obtained image is binarized using an image analysis apparatus (NEW CUBE ver. 4.20 manufactured by NEXUS Co., Ltd.), and the area in the part surrounding the small absorption part is defined as the area of the small absorption part.
The area of the fitting recess is measured in the same manner.

From the viewpoint of more surely achieving one or more of the effects described above, the absorbent body of the present invention preferably has the following configuration.
The density ratio between the small absorbent portion 43 and the bottom portion 42 of the concave portion 41 (the density of the small absorbent portion / the density of the bottom portion of the concave portion) is preferably 1 or more, preferably 10 or less, more preferably 5 or less. Moreover, Preferably it is 1-10, More preferably, it is 1-5.
The density of the small absorbing portion 43 is preferably 0.03 to 0.30 g / cm ³ , more preferably 0.
. The density of the bottom portion 42 of the recess 41 is preferably 0.01 to 0.25 g / cm ^3.
˜0.15 g / cm ³ , more preferably 0.02 to 0.10 g / cm ³ .
The area ratio of the small absorption part 43 is preferably 60 to 95%, more preferably 70 to 80%, and the area ratio of the bottom part 42 of the recess 41 is preferably 5 to 40%, more preferably 5 to 30%. It is.

The basis weight ratio (basis weight of the small absorbent part / basis weight of the bottom part of the recessed part) of the small absorbent part 43 and the bottom part 42 of the recessed part 41 is preferably 1.2 or more, more preferably 1.5 or more. , Preferably 30 or less, more preferably 15 or less, and preferably 1.2 to 30, more preferably 1.5 to 15.
The basis weight of the small absorbent part 43 is preferably 100 to 700 g / m ² , more preferably 300 to 600 g / m ² , and the basis weight of the bottom part 42 of the recess 41 is preferably 10 to 300 g / m ² , and further Preferably it is 30-200 g / m < ² >. The basis weight of the absorbent core 40 is preferably 200 to 800 g / m ² , more preferably 250 to 600 g / m ² .

The density ratio between the small absorbent portion 43 and the bottom portion 42 of the concave portion 41 (the density of the small absorbent portion / the density of the bottom portion of the concave portion) is preferably 1 or more, preferably 10 or less, more preferably 5 or less. Moreover, Preferably it is 1-10, More preferably, it is 1-5.
The density of the small absorption part 43 is preferably 0.03 to 0.30 g / cm ³ , more preferably 0.05 to 0.25 g / cm ³ , and the density of the bottom part 42 of the recess 41 is preferably 0.00. It is 01-0.15 g / cm < ³ >, More preferably, it is 0.02-0.10 g / cm < ³ >.
The area ratio of the small absorption part 43 is preferably 60 to 95%, more preferably 70 to 80%, and the area ratio of the bottom part 42 of the recess 41 is preferably 5 to 40%, more preferably 5 to 30%. It is.

The ratio (t1 / t2) between the thickness t1 (see FIG. 2) of the bottom portion 42 of the recess 41 and the thickness t2 (see FIG. 2) of the small absorbing portion 43 is preferably 0.1 to 0.9, more preferably 0. .2 to 0.8.
The thickness t1 of the bottom portion 42 of the recess 41 is preferably 0.5 to 5.0 mm, more preferably 1.0 to 3.0 mm, and the thickness t2 of the small absorption portion 43 is preferably 2.0 to 10 mm. The thickness is 0 mm, more preferably 2.0 to 7.0 mm.
The thicknesses t1, t2 and t3 of the respective parts referred to here were respectively cut so that the absorbent core 40 was not crushed as much as possible, and the cut surface was observed with a microscope (microscope VHX-manufactured by Keyence Corporation). 1000) and the like, and the thickness of each part is measured without applying a load. The measurement is performed at 10 points, and the average value is taken as the thickness value of each part. Here, the thickness t3 of the pulp fiber layer 44 was measured in a wet state. Specifically, it measured as follows.
Put the absorbent body in a nylon mesh bag, and put it in a container so that the absorbent body can fit without breaking. Pour artificial urine into the container until the surface of the absorber is sufficiently immersed, and leave it to stand. After 1 hour, take out the mesh bag together with the absorbent body and hang it horizontally to remove excess liquid that could not be sucked. After 1 hour, swell, and measure the thickness in this state as described above. did.

The density of each part (the bottom part 42 of the recessed part 41, the small absorption part 43) of the absorptive core 40 is measured according to JIS-P8118: 1998, and is specifically calculated by the following formula.
Density D (g / cm ³ ) = basis weight W (g / m ² ) / thickness T (mm)
The basis weight W in the above formula is measured according to the method described in JIS-P8124, and the bottom portion 42 and the small absorption portion 43 of the concave portion 41 are cut into a certain area according to the processing dimensions, and the weight is measured. Calculate the basis weight. Specifically, the test piece is cut with a cutter or a cutter, the weight of the test piece is measured with a scale, and the basis weight W is calculated by dividing the measured value by the area. The thickness T in the above formula is measured according to JIS-P8118: 1998. However, the thickness T is measured using a peacock precision measuring instrument (model R1-C), which is a micrometer having two parallel pressure surfaces (a fixed pressure surface and a movable pressure surface). The diameter is 5 mm, the pressure is 100 kPa or less, and the size of the measurement test piece is not less than the size of the following plate. A 20 mm × 20 mm plate (weight: 5.4 g) is placed on the test piece, the measuring element movable pressurizing surface is operated at a speed of 2 mm / s, applied to the plate, and the value immediately after stabilization is read. The pressure between the pressing surfaces (pressure applied to the test piece) is 1.3 kPa or less.

  In addition, as the surface sheet 2, the liquid-permeable sheet | seat conventionally used in the said technical field can be used, For example, the nonwoven fabric manufactured by the card | curd method, the spun bond nonwoven fabric, the melt blown nonwoven fabric, the spunlace nonwoven fabric, and the needle Various non-woven fabrics such as punched non-woven fabrics; and films made liquid permeable by opening means. These nonwoven fabrics and films may be subjected to a hydrophilic treatment using a hydrophilic agent such as a surfactant. Examples of the back sheet 3 include various liquids such as a resin film having no moisture permeability, a resin film having fine pores and moisture permeability, a nonwoven fabric such as a water-repellent nonwoven fabric, and a laminate of these and other sheets. An impermeable or water-repellent material can be used. Moreover, as the side sheet | seat 6, the thing similar to the back surface sheet 3 can be used.

Next, the manufacturing method of the absorber 4 is demonstrated. FIG. 7 shows an absorber manufacturing apparatus preferably used for manufacturing the absorber 4.
As shown in FIG. 7, the absorbent body manufacturing apparatus 10 includes a fiber stacking device 11, a pressurizing device 80, and an embossing device 90.
The stacking device 11 is a duct that supplies a stacking drum 13 having a plurality of accumulation recesses 12 formed on the outer peripheral surface thereof at a predetermined interval, and a pulp fiber 49 and a water absorbent polymer 46 to the outer peripheral surface of the stacking drum 13. 14. In FIG. 7, pulp fibers 49 are shown as an air flow with pulp fibers. The duct 14 has one end portion that covers a part of the outer peripheral surface of the stacking drum 13 and the other end portion that is connected to a fiber material introducing device 15 that introduces fibers such as pulp fibers. A water-absorbing polymer 46 introducing device 16 is provided. In the duct 14, a partition member 14 </ b> S is provided that partitions the duct 14 into an upper stage 14 </ b> U through which the water-absorbing polymer 46 flows and a lower stage 14 </ b> D through which the water-absorbing polymer 46 does not flow. The fiber material introducing device 15 includes, for example, a pulverizer that pulverizes sheet-like wood pulp into defibrated pulp, and sends the defibrated pulp as pulp fibers into a duct.

The pile drum 13 has a cylindrical shape and is driven to rotate in the direction of arrow R1 in FIG. On the outer peripheral surface of the stacking drum 13, accumulation concave portions 12, 12... Having a shape corresponding to the shape to be imparted to the absorbent core 40 to be manufactured are formed.
An intake fan (not shown) is connected to the stacking drum 13, and the partitioned spaces D to F in the stacking drum can be maintained at a negative pressure by driving the intake fan. A large number of pores (not shown) are formed on the bottom surfaces of the individual accumulation recesses 12, and the individual accumulation recesses 12 pass through the spaces D to F maintained at negative pressure. The pores at the bottom of the concave portion for accumulation function as suction holes.
Moreover, the air-impermeable member 18 for forming the linear recessed part 41 (41A-41E) is arrange | positioned at the bottom face of the recessed part 12 for accumulation | storage. The non-breathable member 18 is fixed so as to protrude from the bottom surface of the recess 12 for accumulation, and may be a non-breathable member, for example, made of metal or plastic. In FIG. 7, reference numeral 19 denotes an air discharge device for promoting mold release from the accumulation recess 12.

In the same manner as a known fiber stacking apparatus equipped with a fiber stacking drum, absorbent core forming materials 46 and 49 (hereinafter also referred to as core forming materials) are supplied into the duct 14 while sucking from the bottom surface of the accumulation recess 12. As a result, as shown in FIG. 9, the core forming materials 46 and 49 are deposited in a predetermined shape in the accumulation recess 12. Further, by providing the partition member 14S in the duct 14 and providing the lower stage 14D through which the water-absorbing polymer 46 does not flow, only the pulp fibers are first deposited in the accumulation recess 12 as shown in FIG. Thus, after the pulp fiber layer 44 consisting essentially of pulp fibers is formed at the bottom of the accumulation recess, the pulp fibers and the water-absorbing polymer are deposited to form the mixed layer 45.
In the pile 48 of the core-forming material obtained in this manner, a portion (recessed portion) 48a formed by depositing the core-forming material on the air-impermeable member 18 is relatively deposited with the core-forming materials 46 and 49. The amount of the other portion (small absorbing portion corresponding portion) 48b is relatively small, and the amount of the absorbent material 46, 49 is relatively increased, and the piled article 48 as a whole has an uneven structure.

Thereafter, the piled material 48 in the accumulation recess 12 is conveyed to the lower part thereof by the rotation of the piled drum 13, and is transferred onto a known conveying means 17 such as a vacuum conveyor. The core wrap sheet 5A is placed in advance on the transport means 17 before the piled article 48 is transferred, and the piled article 48 moves onto the core wrap sheet 5A. Further, the core wrap sheet 5 </ b> B is placed on the upper surface of the pile 48. And the laminated body 4A which consists of the core wrap sheet | seat 5A and 5B which pinches | interposes the fiber pile 48 and the fiber pile 48 is compressed by the pressurization apparatus 80 in the thickness direction, and reduces the thickness of the fiber pile 48 positively. For example, as shown in FIG. 7, the pressurizing device 80 includes a pair of rolls 81 and 82 having a smooth surface, and can pressurize an object to be pressurized introduced between both rolls from the upper and lower surfaces to compress in the thickness direction. It is configured.
When the entire fiber 48 is compressed by the pressurizing device 80, the small absorbent portion corresponding portion 48b (see FIG. 9) having a relatively large core forming material and a large thickness has a relatively small core forming material and a small thickness. It is compressed more strongly than the recess corresponding part 48a (see FIG. 9). As a result, the small absorbent portion corresponding portion 48b in the piled fiber 48 becomes a small absorbent portion 43 having a relatively high density in the absorbent core 40, and the concave portion corresponding portion 48a in the piled fabric 48 is relatively in the absorbent core 40. Thus, the recesses 41 (41A to 41E) having a low density are obtained.

Then, the pressed laminate 4A is introduced into the embossing device 90. The embossing device 90 includes a pin roll 91 having a number of embossing projections 92 (pins) on the surface and an anvil roll 93 having a smooth surface. When the embossing device 90 is introduced into the laminated body 4A, the pin roll 91 side is disposed on the pulp fiber layer 44 side of the pile 48 that becomes the absorbent core, and the anvil roll is placed on the mixed layer 45 side of the pile 48. 93 is arranged.
In the embossing by the embossing device 90, the core wrap sheet 5B is pushed into the pulp fiber layer 44 of the small absorbent portion 43 of the piled article 48 by the projection 92 of the pin roll 91, whereby the small absorbent of the piled article 48 is absorbed. A fitting recess 47 into which the core wrap sheet 5B is recessed is formed in the portion 43. In this way, the intended absorber 4 is obtained.
The embossing may be performed by heating the pin roll 91 or may be performed without heating the pin roll 91, but when the core wrap sheet and the absorbent core are joined with a hot melt adhesive, In order for the hot melt adhesive to spread to the interface and further improve the strength, the melt viscosity of the hot melt adhesive is preferably 800 mPa · sec or more, more preferably 1000 mPa · sec, more preferably 6000 mPa · sec or less, More preferably, heating is performed so that the pressure is 5000 mPa · sec or less, preferably 800 mPa · sec to 6000 mPa · sec, and more preferably 1000 mPa · sec to 5000 mPa · sec. At this time, it is preferable to heat the pin roll 91, particularly the protrusion 92, to 120 to 160 ° C. Further, the anvil roll 93 may be heated or not heated.

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, the shape of the fitting recess and the indented portion of the core wrap sheet that is indented in the shape of a plane or a symbol of a plus “+” shown in FIG. An arbitrary shape such as a mark shape can be used. Further, the arrangement pattern of the recesses 41 and the planar view shape of the small absorbent portion 43 are not limited to those shown in FIG. 3 and can be appropriately selected. For example, all of the multiple small absorbent portions 43 have the same size in the planar view. The linear recess 41 may be arranged so as to have a rectangular shape. Moreover, the site | part distribute | arranged to the back side part A of the wearer of an absorptive core, the site | part distribute | arranged to the wearer's back side B of an absorptive core, and the crotch part C Of these, it may be formed only in any one part, or may be formed only in any two parts. In addition, instead of forming a fitting recess and an indented part in all of the small absorbing parts formed in the absorbent core, only a part of the small absorbing part has an engaging recess and an indented part thereof. An indented portion may be formed.

In the above embodiment, the absorbent core 40 is coated using the two core wrap sheets 5A and 5B. However, both surfaces of the absorbent core 40 are coated using only one core wrap sheet. May be.
Moreover, in the said embodiment, although the absorptive core 40 was distribute | arranged with the surface 40a by the side of the mixed layer 45 facing the surface sheet 2 side, the surface 40b by the side of the pulp fiber layer 44 was faced by the surface sheet 2 side. It can also be arranged.

Moreover, you may arrange | position transparent sheets (second sheet), such as paper and a nonwoven fabric, between the surface sheet 2 and the core wrap sheet | seat 5A.
Moreover, the absorbent article in the present invention is an incontinence pad, a sanitary napkin, etc., in addition to disposable diapers such as a deployable disposable diaper as shown in FIG. Also good.

  The following absorbers, absorbent articles, and methods for manufacturing the absorbers are disclosed with respect to the above-described embodiments.

<1> An absorbent body comprising an absorbent core and a core wrap sheet sandwiching the absorbent core,
The absorbent core is formed by continuously forming a pulp fiber layer containing pulp fibers and no water-absorbing polymer, and a mixed layer containing pulp fibers and the water-absorbing polymer in the thickness direction,
The absorbent core has, on the surface on the pulp fiber layer side, a linear recess, and a plurality of small absorbent portions formed by dividing the absorbent core into a plurality of regions by the linear recess. And
The small absorbing portion has a higher basis weight than the bottom of the linear recess, and the mixed layer is continuous in the plane direction through the bottom of the linear recess,
A fitting recess recessed from the surface on the pulp fiber layer side that is smaller than the small absorption portion and recessed toward the mixed layer is formed in the small absorption portion, and the core wrap sheet is recessed in each of the fitting recesses. The absorber that is in.

<2> The absorbent body according to <1>, wherein the small absorption part has a higher density than a bottom part of the linear recess.
<3> The absorbent body according to <1> or <2>, wherein a plurality of the fitting recesses are formed with respect to one small absorbent portion of the absorbent core.
<4> The plurality of fitting recesses formed in the one small absorption part have an area inside the annular line having a minimum length that surrounds all of them and is 1/3 or more of the area of the small absorption part The absorber according to <3>, wherein
<5> The plurality of fitting recesses formed in the one small absorption part are similar in shape to the planar view of the small absorption part. The absorbent body according to any one of <1> to <4>, which is arranged as described above.

<6> The absorbent core according to any one of <1> to <5>, wherein the absorbent core has a convex curved end surface.
<7> The small absorption part has an inclined surface formed on both sides sandwiching the top part and the top part, and the depth of the fitting recessed part near the top part is the fitting recessed part near the linear recessed part. The absorber according to any one of <2> to <6>, which is deeper than the depth.
<8> The absorbent body according to <7>, wherein a density around a bottom of the fitting recess near the top is higher than a density around a bottom of the fitting recess near the linear recess.
<9> The absorbent body according to any one of <1> to <8>, wherein a depth of the fitting recess is equal to or greater than a thickness of the pulp fiber layer in a wet state.
<10> The ratio (D / t3) between the depth d of the fitting recess and the thickness t3 of the pulp fiber layer is preferably 2 or more, more preferably 3.5 or more, and preferably 15 or less. The absorbent body according to any one of <1> to <9>, which is preferably 10 or less.

<11> The absorbent core has a shape that is long in one direction in plan view, one end in the longitudinal direction disposed on the back side of the absorbent article, and the length disposed on the ventral side of the absorbent article. The other end portion in the direction, and the central portion disposed in the crotch portion of the absorbent article, the depth of the fitting recess of the small absorbent portion formed in the central portion is the one end portion and the other end portion The absorbent body according to any one of the above items <1> to <10>, which is deeper than a depth of the fitting concave portion of the small absorbent portion formed on the surface.
<12> Ratio of the depth of the fitting recess of the small absorption portion at the center to the depth of the fitting recess of the small absorption portion at each of the one end and the other end (depth at the small absorption portion 43C at the center) / Depth at the small absorption part at one end and the other end) is preferably 1 or more, more preferably 1.2 or more, still more preferably 1.4 or more, and preferably 3 or less. The absorbent according to <11>, preferably 2 or less.
<13> The fitting recess formed in the small absorbent portion has an area ratio of preferably 1% or more, more preferably 3% or more, and preferably 30% or less, more preferably 20% or less, The individual area is preferably 0.1% or more, more preferably 0.2% or more, and preferably 10% or less, more preferably 1% or less of the area of the small absorbent part, <1 The absorber according to any one of> to <12>.
<14> The area of the fitting recess is preferably 3 mm ² or more, more preferably 12 mm ² or more, and preferably 400 mm ² or less, more preferably 300 mm ² or less. <1> to <13> Any one of these.
<15> The basis weight ratio (basis weight of the small absorbent part / basis weight of the bottom part of the recessed part) between the small absorbent part and the bottom part of the linear recessed part is preferably 1.2 or more, more preferably 1.5 or more. Moreover, Preferably it is 30 or less, More preferably, it is 15 or less, The absorber in any one of said <1>-<14>.

<16> The basis weight of the small absorption part is preferably 100 to 700 g / m ² , more preferably 300 to 600 g / m ² , and the basis weight of the bottom of the linear recess is preferably 10 to 300 g / m ^2. m ^2, and still more preferably from 30 to 200 g / m ^2, the <1> to absorbent body according to any one of <15>.
<17> The density ratio of the small absorption part and the bottom of the linear recess (density of the small absorption part / density of the bottom of the linear recess) is preferably 1 or more, and preferably 10 or less. The absorber according to any one of <1> to <16>, which is preferably 5 or less.
<18> A surface sheet that forms a skin facing surface, a back sheet that forms a non-skin facing surface, and an absorbent body disposed between both sheets, wherein the absorbent body is any one of the above items <1> to <17> An absorbent article which is the absorbent article according to claim 1.
<19> The absorbent article according to <18>, wherein the absorbent core included in the absorbent body is disposed with a surface on the mixed layer side facing the top sheet side.
<20> A method for producing the absorber according to any one of <1> to <17>,
Only a pulp fiber is deposited using a pile drum having a stacking recess provided with a partition member for providing a lower stage where a water-absorbing polymer does not flow and a non-breathable member for forming a linear recess is disposed. After the pulp fiber layer consisting essentially of pulp fibers is formed, the pulp fibers and the water-absorbing polymer are deposited to form a mixed layer, and then sandwiched between core wrap sheets and pressed and compressed. The manufacturing method of an absorber which embosses by the pin embossing from the layer side.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to such examples.

[Example 1]
An absorber having the same structure as the absorber 4 shown in FIGS. 2 and 3 was produced. The absorbent core of the obtained absorbent body is a block-type absorbent core having linear concave portions and a plurality of small absorbent portions, and the content of pulp fibers per sheet is 6 g, and the water absorbency per sheet. The polymer content was 9 g. As the core wrap sheet, a core wrap sheet made of paper having a basis weight of 16 g / m ² was used. The thickness of the laminate 4A immediately before embossing was 3.0 mm, and the clearance between the pin roll 91 and the anvil roll 93 used for embossing was 0.80 mm. The clearance here is the distance between the tip of the projection 92 of the pin roll 91 and the surface of the anvil roll 93.
In addition, embossing is performed so that a plurality of fitting recesses are formed in each small absorption part, the area ratio of the fitting recesses formed in the small absorption part is 10%, and the area of each fitting recess is It was 0.3% of the area of the small absorption part. Moreover, in the obtained absorber, the difference had arisen in the depth of the fitting recessed part in a longitudinal direction center part, and the depth of the fitting recessed part in a longitudinal direction both ends.

[Example 2]
In Example 1, an absorbent body was produced in the same manner as in Example 1 except that the clearance during embossing was changed to 0.96 mm.

[Comparative Example 1]
In Examples 1 and 2, the laminate immediately before embossing was used as a sample of Comparative Example 1.

[Evaluation of absorber]
About each sample (absorber) of an example and a comparative example, the depth of a fitting crevice, measurement of peel strength, and a drop test were done, and the stability of the structure of an absorptive core was evaluated. The results are shown in Table 1. Moreover, the basic weight of the small absorption part of each sample (absorber) of an Example and a comparative example and the basic weight of the bottom part of a linear recessed part were measured, and the result was shown in Table 1.

<Fitting recess depth>
Using a microscope VHX-1000 manufactured by Keyence Co., Ltd., observation is performed at a magnification of 20 times, and an average value of 10 points is taken as a measurement value. The measurement part of the sample used a feather shaving blade S (single blade) and pressed to make a cut surface. The central portion in the longitudinal direction was measured by measuring the depth of the fitting recess 47t from the top of the small absorbing portion 43C and the longitudinal end portions of the small absorbing portion 43A and the small absorbing portion 43B, respectively, and averaging them. Further, the depth d1 of the fitting recess 47t from the top of the small absorbing portion and the depth d2 of the fitting recess 47s near the small absorbing portion linear recess are five depths in the small absorbing portion 43A and the small absorbing portion 43B, respectively. Measured and averaged.

<Peel strength>
120 g of artificial urine is collectively injected over a period of 1 minute using a funnel with the absorber front side end 165 mm as an injection point in a developed state where the absorber is bonded to the top sheet and the back sheet. Cut the sample with a width of 70 mm and a length of 170 mm (position of 70 mm from the injection point on the front side and 100 mm on the back side), sandwich the backing and the surface material together with a clip, and use a tensile strength measuring instrument (push-pull gauge manufactured by Aiko Engineering). And measure the peel strength. The value reads the maximum value.

<Drop test>
120 g of artificial urine is collectively injected over a period of 1 minute using a funnel with the absorber front side end 165 mm as an injection point in a developed state where the absorber is bonded to the top sheet and the back sheet. After standing for 3 minutes, the sample is attached to a human body model made of rubber, and the legs are opened and closed 10 times. The sample is removed, and the end is pinched by a clip suspended from a string having a length of 120 mm in a folded state. Pull up the clip to the position of the bar where the string is fixed, and then let go and let it fall naturally. Repeat the fall until the absorber breaks (until it separates). Absorber breakage is confirmed by tactile sensation after dropping the sample, and if there is no breakage, it is dropped again. The number of drops until the absorber breaks is regarded as a drop test evaluation, and the higher the number, the better the shape retention after liquid absorption.

[Evaluation of diapers]
The disposable diaper was manufactured using each sample of an Example and a comparative example, and the liquid return amount under pressure was measured with the following method by the following method. The results are shown in Table 1 below. The disposable diaper used the following as a surface sheet and a back surface sheet, and comprised the absorber of an Example and a comparative example between these.
Top sheet: Air-through nonwoven fabric with basis weight of 25 g / m ² comprising polyethylene terephthalate (PET) fiber, polyethylene (PE) fiber, polypropylene (PP) fiber Back sheet: PE resin film with basis weight of 20 g / m ²

<Measurement method of the amount of returned liquid under pressure>
In a state where the disposable diaper is expanded in a flat shape and the top sheet is fixed on a horizontal surface with the top sheet facing upward, a load of 2 kPa per 30 cm × 10 cm area is applied to the diaper and the top sheet is placed on the top sheet at the center of the absorber. 40 g of artificial urine was injected and absorbed, allowed to stand for 10 minutes, and then 40 g of artificial urine was injected and absorbed. Such artificial urine injection operation was repeated four times, and a total of 160 g of artificial urine was absorbed in the diaper. Next, 16 sheets of ADVANTEC 5C filter paper were stacked on the artificial urine absorption site in the diaper, and further, a load was applied for 2 minutes to absorb the artificial urine absorbed in the diaper on the filter paper. The load on the filter paper was such that 3.5 kg was added to an area of 10 cm × 10 cm. After 2 minutes, the load was removed, and the weight of the filter paper that absorbed artificial urine was measured. The weight of the filter paper before artificial urine absorption was subtracted from this weight, and the value was taken as the liquid return amount. The smaller the liquid return amount, the higher the utilization efficiency of the absorber (absorbent core) and the higher the evaluation. Table 1 below shows the relative value of the liquid return amount based on the liquid return amount of Comparative Example 1 (the liquid return amount of the sample / the liquid return amount of the sample of Comparative Example 1).

  The composition of artificial urine is as follows. 1.940% by weight of urea, 0.795% by weight of sodium chloride, 0.111% by weight of magnesium sulfate (pentahydrate), 0.062% by weight of calcium chloride (dihydrate), 0.198% by weight of potassium sulfate , Polyoxyethylene lauryl ether 0.004 mass% and ion-exchanged water (remaining amount).

As shown in Table 1, the absorbers of Examples 1 and 2 were superior to the absorber of Comparative Example 1 in both peel strength and the number of drop tests.
Moreover, when the surface by the side of the core wrap sheet which coat | covers a pulp fiber layer was observed, almost no damage was recognized by the intrusion part of Examples 1 and 2. FIG.
Moreover, when the absorbers of Examples 1 and 2 and the absorber of Comparative Example 1 were held in hand and compared for flexibility, no clear difference was observed in flexibility, and both had good flexibility. Had.
Moreover, the disposable diaper using the absorber of Example 1 and 2 is also less than the disposable diaper using the absorber of the comparative example 1 also about the liquid return amount under pressure, and it is confirmed that it is excellent also in absorption performance. It was done.

1 disposable diaper (absorbent article)
2 Top sheet 3 Back sheet 4 Absorber 40, 40A Absorbent core 40b One side of the pulp fiber layer 40a One side of the mixed layer side 41, 41A to 41E Linear recess 42 Bottom of the linear recess 43 Small absorber 5A, 5B Core Wrap sheet 51 Indented portion of core wrap sheet 11 Stacking device 12 Concave for accumulation 13 Stacking drum 14 Duct 14U Upper stage 14D Lower stage 14S Partition member 43, 43A to 43C Small absorbent part 44 Pulp fiber layer 45 Mixed layer 46 Water-absorbing polymer 47 , 47t, 47s Fitting recess 49 Pulp fiber 80 Pressure device 90 Embossing device 91 Pin roll 92 Projection (pin)
93 Anvil Roll

Claims (8)

An absorbent body comprising an absorbent core and a core wrap sheet sandwiching the absorbent core,
The absorbent core is formed by continuously forming a pulp fiber layer containing pulp fibers and no water-absorbing polymer, and a mixed layer containing pulp fibers and the water-absorbing polymer in the thickness direction,
The absorbent core has, on the surface on the pulp fiber layer side, a linear recess, and a plurality of small absorbent portions formed by dividing the absorbent core into a plurality of regions by the linear recess. And
The small absorbing portion has a higher basis weight than the bottom of the linear recess, and the mixed layer is continuous in the plane direction through the bottom of the linear recess,
A fitting recess recessed from the surface on the pulp fiber layer side that is smaller than the small absorption portion and recessed toward the mixed layer is formed in the small absorption portion, and the core wrap sheet is recessed in each of the fitting recesses. It has been input,
A plurality of the fitting recesses are formed for one small absorbent portion of the absorbent core,
The small absorbing portion has a top portion and inclined surfaces formed on both sides sandwiching the top portion, and the depth of the fitting recess near the top is larger than the depth of the fitting recess near the linear recess. Deep, absorber. The plurality of fitting recesses formed in the one small absorbent part have an area inside the annular line that surrounds the whole of the small absorbent part and is 1/3 or more of the area of the small absorbent part. The absorber according to claim 1 . The plurality of fitting recesses formed in the one small absorption part are arranged so that the shape of the annular line that surrounds the whole of the small absorption part is the same as the planar view shape of the small absorption part. The absorber according to claim 1 or 2, wherein An absorbent body comprising an absorbent core and a core wrap sheet sandwiching the absorbent core,
The absorbent core is formed by continuously forming a pulp fiber layer containing pulp fibers and no water-absorbing polymer, and a mixed layer containing pulp fibers and the water-absorbing polymer in the thickness direction,
The absorbent core has, on the surface on the pulp fiber layer side, a linear recess, and a plurality of small absorbent portions formed by dividing the absorbent core into a plurality of regions by the linear recess. And
The small absorbing portion has a higher basis weight than the bottom of the linear recess, and the mixed layer is continuous in the plane direction through the bottom of the linear recess,
A fitting recess recessed from the surface on the pulp fiber layer side that is smaller than the small absorption portion and recessed toward the mixed layer is formed in the small absorption portion, and the core wrap sheet is recessed in each of the fitting recesses. And
The depth of the fitting recess is not less than the thickness of the pulp fiber layer in a wet state, the absorber. An absorbent body comprising an absorbent core and a core wrap sheet sandwiching the absorbent core,
The absorbent core is formed by continuously forming a pulp fiber layer containing pulp fibers and no water-absorbing polymer, and a mixed layer containing pulp fibers and the water-absorbing polymer in the thickness direction,
The absorbent core has, on the surface on the pulp fiber layer side, a linear recess, and a plurality of small absorbent portions formed by dividing the absorbent core into a plurality of regions by the linear recess. And
The small absorbing portion has a higher basis weight than the bottom of the linear recess, and the mixed layer is continuous in the plane direction through the bottom of the linear recess,
A fitting recess recessed from the surface on the pulp fiber layer side that is smaller than the small absorption portion and recessed toward the mixed layer is formed in the small absorption portion, and the core wrap sheet is recessed in each of the fitting recesses. And
The absorbent core has a shape that is long in one direction in a plan view, and includes one end in the longitudinal direction disposed on the back side of the absorbent article, and the other in the longitudinal direction disposed on the ventral side of the absorbent article. An end portion and a central portion disposed in the crotch portion of the absorbent article, and a depth of a fitting recess of a small absorbent portion formed in the central portion is formed in the one end portion and the other end portion. deeper than the depth of the fitting recess of the small absorption portions, the absorbent body. Fitting recess formed in the small absorber unit is the area ratio of 1% to 30%, each area is from 0.1 to 10% of the area of the small absorption unit, any one of claims 1 to 5 absorbent body according to item 1. Surface sheet forming the skin-facing surface, the backsheet to form a non-skin-facing side, and provided with the placed absorber between the two sheets, the absorbent body, according to any one of claims 1 to 6 Absorbent article that is an absorber. The absorptive article according to claim 7 in which said absorptive core contained in said absorber is arranged with said field at said mixed layer side facing said surface sheet side.

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