JP2015112341A - Absorbent article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorbent article that is excellent in absorbency of body fluid and makes it difficult to cause return of liquid.SOLUTION: On the skin-facing side of an absorbent core 40, a body fluid backflow prevention layer 5, which is liquid permeable, is arranged for preventing shift of body fluid from the absorbent core 40 to the skin of a wearer. The body fluid backflow prevention layer 5 comprises dry non-woven cloth or dry web. A water-repellent part 50 and a hydrophilic part 51 are arranged on the skin-facing side 5a and non-skin-facing side 5b of the body fluid backflow prevention layer 5 respectively. The hydrophilic part 51 is located in the area of the skin-facing side 5a of the body fluid backflow prevention layer 5, which area corresponds to the water repellent part 50 of the non-skin-facing side 5b of the body liquid backflow prevention layer 5. Also, the hydrophilic part 51 is located in the area of the non-skin-facing side 5b, which area corresponds to the water repellent part 50 of the skin-facing side 5a.

Description

  The present invention relates to an absorbent article such as a disposable diaper.

  As an absorbent article, an absorptive core that absorbs and retains excreted bodily fluids is provided, and an abdominal side portion disposed on the abdomen side of the wearer, a back side portion disposed on the back side, and a crotch positioned therebetween An absorbent article having a longitudinal direction extending from the abdominal side portion to the back side portion via the crotch portion and a lateral direction perpendicular thereto is known. With respect to the absorbent article having such a configuration, for example, Patent Document 1 discloses that the body surface such as menstrual blood absorbed in the absorbent core is difficult to visually recognize from the outside on the skin facing surface side of the absorbent core. It is described that a color masking layer containing a material is disposed. As a specific example, the color masking layer functions as a surface sheet that can come into contact with the wearer's skin, or on the skin facing surface side of the absorbent core. There is described a form in which a surface sheet is arranged and a color masking layer is interposed between the surface sheet and the absorbent core. The color masking layer includes a liquid-permeable support cloth such as a hydrophilic nonwoven fabric and a color pattern that is arranged on the skin facing surface side of the support cloth and in which a colored hydrophobic material is arranged in a predetermined pattern. Yes.

  Moreover, in patent document 2, the part which contributes to the absorption of the bodily fluid in an absorptive core concentrates on the part located in the vicinity of a wearer's excretion part, and the longitudinal direction front-and-back end part of an absorptive core contributes to absorption almost. In view of the above, on the top sheet, a liquid-permeable liquid-permeable region and a liquid-impervious liquid-impermeable region extending in the longitudinal direction in a plan view are arranged, and the liquid-permeable region and the liquid-impermeable region Are alternately arranged in the horizontal direction. This surface sheet is obtained by subjecting a part of a non-woven fabric having hydrophobicity to a hydrophilic treatment, and the portion subjected to the hydrophilic treatment is the liquid-permeable region, and the portion not subjected to the hydrophilic treatment is the impervious portion. It is a liquid region, and at least the region impervious liquid exists over the entire region in the thickness direction of the topsheet.

JP 2005-525132 A JP 2012-252 A

  In absorbent articles such as disposable diapers, body fluids such as excreted urine permeate through the topsheet and are absorbed and retained by the absorbent core, but are absorbed and retained by the absorbent core due to the effects of body pressure during wearing. In some cases, so-called fluid return occurs where the applied body fluid returns to the skin side of the wearer. Liquid return can cause discomfort to the wearer and can cause skin problems such as swelling and fogging. There is room for improvement in coexistence of the performance of the absorbent article which is excellent in the absorbability of body fluid and hardly causes liquid return.

  Therefore, this invention relates to the absorbent article which is excellent in the absorbability of a bodily fluid, and does not raise | generate a liquid return easily.

  The present invention comprises an absorptive core that absorbs and holds excreted body fluid, and is provided on the abdomen side of the wearer, the dorsal side part arranged on the dorsal side, and the crotch part positioned therebetween. And an absorbent article having a longitudinal direction extending from the abdominal side portion to the back side portion via the crotch portion and a lateral direction perpendicular thereto, and the skin facing surface side of the absorbent core Further, a fluid-permeable body fluid backflow prevention layer for preventing the body fluid from transferring from the absorbent core to the wearer's skin is disposed, and the body fluid backflow prevention layer includes a dry nonwoven fabric or a dry web. A water repellent part and a hydrophilic part are disposed on the skin facing surface and the non-skin facing surface of the body fluid backflow preventing layer, respectively, and the body fluid backflow preventing layer is not on the skin facing surface of the body fluid backflow preventing layer. The hydrophilic part is located in a portion corresponding to the water repellent part on the skin facing surface, and the body fluid backflow prevention layer In the non-skin-facing side, a portion corresponding to the water-repellent part of the skin-facing side of the body fluid backflow prevention layer, there is provided an absorbent article wherein the hydrophilic portion is located.

  ADVANTAGE OF THE INVENTION According to this invention, the absorbent article which is excellent in the absorbability of a bodily fluid and does not raise | generate a liquid return easily is provided.

FIG. 1 is a partially broken plane on the surface sheet side (skin facing surface side) showing a developed state in which a disposable diaper as an embodiment of the absorbent article of the present invention is expanded in a flat shape by stretching the elastic members of each part. FIG. FIG. 2 is a schematic cross-sectional view taken along the line II of FIG. FIG. 3 is a cross-sectional view schematically showing a main part (laminated structure of a surface sheet, a bodily fluid backflow prevention layer and an absorber) in the cross section taken along the line II of FIG. 4 is a cross-sectional view schematically showing a state of the body fluid backflow prevention layer during wearing of the diaper shown in FIG. 1, FIG. 4 (a) is a cross-sectional view when no pressure is applied, and FIG. It is sectional drawing at the time of pressure. FIG. 5 is an explanatory diagram of a method for measuring water passage time (liquid permeability evaluation method). FIG. 6A to FIG. 6E are plan views schematically showing the skin facing surface side of a preferable example of the bodily fluid backflow prevention layer according to the present invention. Fig.7 (a)-FIG.7 (c) are each a top view which shows typically the skin opposing surface side of another example of the bodily fluid backflow prevention layer which concerns on this invention. FIG. 8 is a plan view schematically showing the skin facing surface side of still another example of the bodily fluid backflow prevention layer according to the present invention. FIG. 9 is a plan view schematically showing the skin facing surface side of still another example of the bodily fluid backflow prevention layer according to the present invention.

  The absorbent article of the present invention includes a liquid-permeable body fluid backflow prevention layer, as will be described in detail later. The body fluid backflow prevention layer according to the present invention has liquid permeability, and more specifically, the water passage time measured by the following method is less than 20 seconds. The shorter the water passage time, the higher the liquid permeability (hydrophilicity) of the body fluid backflow prevention layer. The water passage time of the body fluid backflow preventing layer according to the present invention is preferably less than 15 seconds, more preferably less than 10 seconds.

<Measurement method of water passage time>
As shown in FIG. 5, the measurement target sheet 90 (body fluid backflow prevention layer 5) is sandwiched and fixed by a pair of glass cylinders 93 and 94 having a diameter of 35 mm via rubber packings 92 and 92 from above and below. Then, 40 g of ion exchange water is supplied to the upper cylinder 93. The time from the start of the supply of ion exchange water until the weight of the ion exchange water passing through the sheet 90 and accumulating in the lower cylinder 94 reaches 20 g is measured, and this time is taken as the water passage time. The weight of the ion exchange water is measured by an electronic balance 96 equipped with a liquid tray 95.

  Hereinafter, the absorbent article of the present invention will be described based on a disposable diaper which is a preferred embodiment thereof with reference to the drawings. The diaper 1 of the present embodiment includes an absorbent core 40 that absorbs and retains excreted body fluids, and in the worn state, a ventral side A disposed on the wearer's ventral side and a dorsal side C disposed on the dorsal side. , And a crotch lower part B located between them and disposed in the wearer's crotch part, and a longitudinal direction X and a transverse direction Y orthogonal thereto. The longitudinal direction X of the diaper 1 is a direction that extends between the abdominal side A and the back side C via the crotch B.

  More specifically, the diaper 1 is a so-called unfolded disposable diaper, as shown in FIG. 1 and FIG. 2, which forms a skin-facing surface and can be in contact with the wearer's skin when the diaper 1 is worn. The surface sheet 2, the liquid-impermeable or water-repellent (hereinafter collectively referred to as liquid-impermeable) back-surface sheet 3 that forms the non-skin facing surface, and the absorbent core 40. The liquid-retaining absorbent body 4 disposed between the sheets 2 and 3 is provided, has a long shape in one direction (longitudinal direction X) in a plan view as shown in FIG. 1, and is substantially vertically long. .

  In addition, in this specification, a skin opposing surface is a surface which faces a wearer's skin side at the time of wear of an absorbent article in the absorbent article (diaper 1) or its component (for example, bodily fluid backflow prevention layer 5 mentioned later). The non-skin-facing surface is a surface of the absorbent article or its constituent members that is directed to the side opposite to the skin side (clothing side) when the absorbent article is worn.

  Each of the top sheet 2 and the back sheet 3 has a size larger than that of the absorbent body 4 (absorbent core 40), and extends outward from the periphery of the absorbent body 4. The back sheet 3 forms the outer shape of the diaper 1 in the unfolded and stretched state as shown in FIG. As the top sheet 2 and the back sheet 3, various types conventionally used for this type of absorbent article can be used without particular limitation. For example, various nonwoven fabrics or apertured films can be used as the top sheet 2, and a resin film, a laminate of a resin film and a nonwoven fabric, or the like can be used as the back sheet 3. The back sheet 3 includes, for example, a liquid-impermeable film sheet alone and a form in which an exterior sheet (for example, a nonwoven fabric) is laminated on the non-skin facing surface (outer surface) side of the film sheet.

  As shown in FIG. 1, the diaper 1 has an abdominal side A disposed on the stomach side of the wearer, a crotch B disposed on the crotch portion, and a back side C disposed on the back side when worn. X has. The abdominal side A, the crotch B and the back side C are arranged in the longitudinal direction X (the back sheet or the exterior when the exterior sheet is disposed on the non-skin facing surface side of the back sheet). It corresponds to each part when it is divided into three equal parts in the longitudinal direction of the sheet, and the middle part of the three parts is the crotch part B. The diaper 1 has an hourglass shape in which both side edges along the longitudinal direction X of the crotch part B are curved inwardly in an arc shape, and in the plan view shown in FIG. It has the shape of The crotch part B includes an excretion part facing part D that is disposed to face the excretion part of the wearer when worn. The excretory part facing part D is in a position slightly deviated closer to the abdominal side A than the center of the diaper 1 in the vertical direction X (a virtual center line that bisects the diaper 1 in the vertical direction X). It exists in the boundary of the side part A and the crotch part B, and its vicinity.

  As shown in FIG. 1, the absorbent body 4 includes a liquid-retaining absorbent core 40 and a water-permeable core wrap sheet 41 that covers the skin facing surface and the non-skin facing surface of the absorbent core 40. It is configured. The core wrap sheet 41 is a single continuous sheet having a width that is two to three times the length of the absorbent core 40 in the lateral direction Y. The core wrap sheet 41 covers the whole area of the skin facing surface of the absorbent core 40 and extends outward from both side edges along the longitudinal direction X of the absorbent core 40 in the lateral direction Y. It is rolled down below the absorbent core 40 to cover the entire area of the non-skin facing surface of the absorbent core 40. The absorbent core 40 and the core wrap sheet 41 may be joined by a known joining means such as a hot-melt adhesive. Examples of the absorbent core 40 include a fiber aggregate made of hydrophilic fibers such as synthetic fiber treated with wood pulp and a hydrophilizing agent, or a fiber aggregate in which a particulate water-absorbing polymer is held. Can be used. As the core wrap sheet 41, paper, non-woven fabric (hydrophilic non-woven fabric made of fibers subjected to hydrophilization treatment) or the like can be used.

  Between the top sheet 2 and the back sheet 3 in the waist portions (ends in the longitudinal direction X) of the ventral side portion A and the back side portion C, a thread-like elastic member 31 is stretched along the lateral direction Y. The waist gathers are formed by the contraction of the elastic member 31 at the waist when the diaper 1 is worn. Further, between the top sheet 2 and the back sheet 3 in the left and right leg portions arranged around the legs of the wearer, a thread-like elastic member 32 is fixed in an extended state along the longitudinal direction X. Thus, a pair of leg gathers is formed in the leg portion when the diaper 1 is worn by contraction of the elastic member 32. Moreover, the side seat | sheet 34 is distribute | arranged to the left-right both sides along the vertical direction X in the surface sheet 2 side of the diaper 1, respectively. A thread-like elastic member 33 is fixed to the inner edge of the side seat 34 in a stretched state along the longitudinal direction X. Accordingly, when the diaper 1 is worn, the elastic member 33 contracts at least in the crotch B. A gather is formed. The top sheet 2, the back sheet 3, the absorber 4, the elastic members 31, 32, 33 and the side sheet 34 are joined to each other by a known joining means such as a hot-melt adhesive.

  As shown in FIG. 1, a pair of fastening tapes 35, 35 are provided on both side edges along the longitudinal direction X of the back side C of the diaper 1. A fastening portion (not shown) made of a male member of a mechanical surface fastener is attached to the fastening tape 35. In addition, a non-skin facing surface (non-skin facing surface of the back sheet 3) of the ventral side portion A of the diaper 1 is formed with a to-be-attached region 36 made of a female member of a mechanical surface fastener. The to-be-attached region 36 is formed by joining and fixing a female member of a mechanical hook-and-loop fastener to the non-skin facing surface of the back sheet 3 by a known joining means (for example, an adhesive or heat seal). The fastening portion of the tape 35 can be detachably fastened.

  As one of the main features of the diaper 1 of this embodiment, as shown in FIGS. 1 and 2, body fluid is transferred from the absorbent core 40 to the skin side of the wearer on the skin facing surface side of the absorbent core 40. The liquid-permeable body fluid backflow prevention layer 5 for preventing (so-called liquid return) is provided. The body fluid backflow prevention layer 5 is configured to include a base material (sublayer), and the base material is composed of a single layer structure sheet (dry nonwoven fabric), and has a rectangular shape that is long in the longitudinal direction X in plan view, It arrange | positions on the skin opposing surface of the absorber 4, making the longitudinal direction correspond to the vertical direction X. FIG. The lengths of the body fluid backflow prevention layer 5 in the longitudinal direction X and the transverse direction Y are the same as those of the absorbent body 4 (absorbent core 40), and the skin facing surface of the absorbent body 4 (skin facing surface of the absorbent core 40). The whole area of the core wrap sheet 41 on the side facing the skin) is covered with the body fluid backflow prevention layer 5.

  FIG. 3 shows a main part (laminated structure of the topsheet 2, the body fluid backflow prevention layer 5, and the absorber 4) of the cross section taken along the line II in FIG. ) Is schematically shown. In FIG. 3 and FIG. 4 to be described later, illustration of the absorbent core 40 and the core wrap sheet 41 (FIGS. 1 and 2) constituting the absorber 4 is omitted, and the illustration of the absorber 4 is simplified. As shown in FIG. 3, a water repellent part 50 and a hydrophilic part 51 are disposed on the skin facing surface 5a and the non-skin facing surface 5b of the body fluid backflow prevention layer 5, respectively.

  As shown in FIG. 3, a hydrophilic portion 51 is located at a portion corresponding to the water repellent portion 50 of the non-skin facing surface 5 b of the body fluid backflow prevention layer 5 in the skin facing surface 5 a of the body fluid backflow prevention layer 5. Yes. Further, a hydrophilic portion 51 is located at a portion of the non-skin facing surface 5b of the bodily fluid backflow prevention layer 5 that corresponds to the water repellent portion 50 of the skin facing surface 5a of the bodily fluid backflow prevention layer 5. That is, in the planar projection from the skin facing surface 5a or the non-skin facing surface 5b of the bodily fluid backflow prevention layer 5, the water repellent portion 50 of the skin facing surface 5a and the hydrophilic portion 51 of the non-skin facing surface 5b overlap, and The hydrophilic part 51 of the skin facing surface 5a and the water repellent part 50 of the non-skin facing surface 5b overlap.

  Further, the skin facing surface 5a and the vicinity thereof and the non-skin facing surface 5b and the vicinity thereof of the bodily fluid backflow prevention layer 5, that is, the portion (inside) other than the surface layer portion of the bodily fluid backflow prevention layer 5 is composed of only the hydrophilic portion 51. In the body fluid backflow prevention layer 5, the water repellent part 50 is disposed only in the surface layer part. Thus, the bodily fluid backflow prevention layer 5 is mainly composed of the hydrophilic portion 51 and therefore has liquid permeability. The “liquid permeability” here is as described above.

  The state of the bodily fluid backflow prevention layer 5 during wearing of the diaper 1 is shown in FIG. FIG. 4 (a) shows no pressure (when the wearer's body pressure is not applied), and FIG. 4 (b) shows the pressure (when the wearer's body pressure is applied). When body fluid such as urine is excreted from the excretion part of the wearer while the diaper 1 is worn, the body fluid first comes into contact with the top sheet 2 and permeates through the thickness direction to reach the body fluid backflow prevention layer 5. To do. At this time, if the wearer's body pressure is not applied to the bodily fluid backflow prevention layer 5 because the wearer of the diaper 1 is in a standing position, the bodily fluid is in FIG. 4 (a). As shown by the arrows, the body fluid backflow prevention layer 5 is quickly drawn into the skin from the hydrophilic portion 51 of the skin facing surface 5a, and the body fluid backflow prevention layer 5 is shifted in the thickness direction toward the absorber 4 side. 51 reaches the water-repellent part 50 of the non-skin facing surface 5b, which overlaps with 51 in plan view. Since the water repellent part 50 inhibits the permeation of the body fluid, the body fluid does not permeate the water repellent part 50 that has first reached the non-skin facing surface 5b, and moves to the hydrophilic part 51 in the vicinity thereof, from which the absorber Move to 4. As described above, since the body fluid flow path is formed inside the body fluid backflow prevention layer 5 when no pressure is applied, the body fluid backflow prevention layer 5 exhibits excellent liquid permeability and the body fluid absorption rate is impaired. I can't.

  On the other hand, in the case of a conventional disposable diaper (a diaper not provided with the body fluid backflow prevention layer 5), the wearer's body is placed on the absorbent body inside the diaper by changing the posture from standing to sitting. When pressure is applied, body fluids such as urine absorbed and held by the absorbent body may return to the wearer's skin side and adhere to the wearer's skin. On the other hand, in the diaper 1 of the present embodiment, when the absorbent body 4 is pressurized, the bodily fluid backflow prevention layer 5 disposed on the skin facing surface side is in the thickness direction as shown in FIG. Compressed and deformed to be thin, the water repellent part 50 of the skin facing surface 5a and the water repellent part 50 of the non-skin facing surface 5b come close to each other. The flow path in the layer thickness direction of the body fluid is significantly reduced or disappears. Since the body fluid backflow prevention layer 5 thus compressed and deformed inhibits the transfer of body fluid from the absorbent body 4 to the topsheet 2 side, liquid return is effectively suppressed.

  Further, the bodily fluid backflow prevention layer 5 has a configuration in which the water-repellent portions 50 are arranged on both surfaces (skin facing surface and non-skin facing surface) of a sheet having a single layer structure. Alternatively, a two-layer structure formed by laminating two sheets having a single-layer structure may be used as the body fluid backflow prevention layer according to the present invention. In that case, one layer constituting the two-layer structure And the form by which the water repellent part and the hydrophilic part are distribute | arranged to each non-skin opposing surface of the other layer can be considered. However, in such a two-layer structure, an unintentional deviation occurs in the positional relationship between one layer and the other layer due to external force during manufacture or use (when wearing a diaper), thereby causing the water repellent part and There is a possibility that the hydrophilic portion is displaced from the appropriate position, and the above-described effects are not achieved. On the other hand, a body fluid backflow prevention layer in which a water repellent part and a hydrophilic part are arranged on both surfaces of a sheet having a single layer structure like the body fluid backflow prevention layer 5 of this embodiment is concerned with a two-layer structure. Since there is no positional shift and the proper positions of the water repellent part and the hydrophilic part are maintained, the above-described operational effects are stably achieved.

The hydrophilic portion 51 preferably has a droplet residual ratio of 30% or less, more preferably 20% or less, and particularly preferably 0% when 30 seconds have elapsed after droplet transfer, as measured by the following method (droplet method).
On the other hand, the water repellent part 50 preferably has a droplet remaining rate of more than 80% at the point of 30 seconds after the droplet transfer measured by the following method (droplet method). It is more preferable that the residual ratio of the liquid droplets at the time when 1 minute has elapsed after the liquid droplet transfer to be measured is 100%.
The droplet remaining rate is an evaluation index of the hydrophilicity (water repellency) of the measurement target portion. The smaller the numerical value, the higher the hydrophilicity (low water repellency).

<Measurement method of droplet residual ratio (droplet method)>
Using a dropper that can form a drop and weighs 0.3 to 0.35 g, forms a drop at the tip of the dropper, and measures the drop as a measurement sample (body fluid backflow prevention layer) Gently move to the part (water repellent part or hydrophilic part). The liquid used for forming the droplets is water, and the surface tension of the ion-exchanged water to be used is measured in advance to confirm that it is 70 mN / m or more. Droplet transfer is performed for each of 10 or more, preferably 20 or more, measurement target portions in the measurement sample, and the remaining number of droplets after 30 seconds or 1 minute has elapsed after the transfer is 100 minutes. The calculated value is used as the droplet remaining rate of the measurement target portion. The determination as to whether or not the droplet remains in the measurement target portion is performed as follows. That is, the width (at an arbitrary position) at the contact surface between the droplet and the measurement target portion is compared with the width at the apex of the droplet and the approximate middle point of the contact surface, and the width at the contact surface is the intermediate point. If it is within 1.2 times the width at, it is considered that a droplet remains, and when there is no droplet and when the width at the contact surface exceeds 1.2 times the width at the intermediate point (ie , When the liquid droplet spreads), it is considered that no liquid droplet remains.

  In this embodiment, the bodily fluid backflow prevention layer 5 is arranged between the topsheet 2 and the absorbent body 4 (absorbent core 40) as shown in FIGS. That is, the bodily fluid backflow prevention layer 5 is not exposed and is disposed so as not to touch the wearer's skin when the diaper 1 is worn. In the absorbent article of the present invention, the body fluid backflow prevention layer 5 may be disposed on the skin facing surface side of the absorbent core 40 (absorbent body 4). A form that forms one skin facing surface and is arranged so as to be in contact with the skin of the wearer ”is also included. However, when the body fluid backflow prevention layer 5 is disposed between the topsheet 2 and the absorbent body 4 as in the present embodiment, the water repellent portion 50 of the skin facing surface 5a is covered with the topsheet 2. Therefore, it is difficult for body fluid to accumulate on the water repellent portion 50, and even if the body fluid accumulates on the water repellent portion 50, the topsheet 2 is interposed between the body fluid and the skin of the wearer. Since the bodily fluid is effectively prevented from touching the skin, the above-mentioned “form in which the bodily fluid backflow preventing layer 5 forms the skin-facing surface of the diaper 1 and can come into contact with the wearer's skin”. More preferred.

  Further, in the present embodiment, as shown in FIG. 3, the hydrophilic portion 51 is arranged on the vertical center line Cx that bisects the skin facing surface 5 a of the body fluid backflow preventing layer 5 in the lateral direction Y. Has been. The part of the skin facing surface 5a that overlaps the vertical center line Cx (the center in the lateral direction), particularly the part of the crotch B (excretion part facing part D) is a part where the excretion of the excreted body fluid is necessarily performed. Since the hydrophilic portion 51 is disposed in the portion, the body fluid is quickly drawn into the body fluid backflow prevention layer 5 through the hydrophilic portion 51 and is transferred to the absorber 4 side. The absorption speed is improved as compared with the case where the water repellent part 50 is disposed in the part. From the viewpoint of more surely exhibiting such operational effects, the length (width) in the lateral direction Y of the hydrophilic portion 51 of the portion overlapping the vertical center line Cx in the skin facing surface 5a of the bodily fluid backflow prevention layer 5 is: It is preferable that it is the same as that of the water repellent part 50 located in the both sides of the horizontal direction Y of this hydrophilic part 51, or longer than it.

  From the viewpoint of more reliably preventing liquid return, the bodily fluid backflow prevention layer 5 has a water repellent portion 50 on one surface 5a (or surface 5b) in a planar projection from the skin facing surface 5a or the non-skin facing surface 5b. It is preferable that the other surface 5b (or the surface 5a) has a water-repellent reinforced region in which the water-repellent portion 50 is arranged without the hydrophilic portion 51 interposed therebetween. The body fluid backflow prevention layer 5 shown in FIGS. 3 and 4 is the water repellent enhancement region itself. As shown in FIG. 4 (b), the water repellent enhanced region having such a configuration includes a hydrophilic portion 51 of the skin facing surface 5a and a hydrophilic portion 51 of the non-skin facing surface 5b of the bodily fluid backflow prevention layer 5, as shown in FIG. Therefore, the formation of the flow passage in the layer thickness direction of the body fluid at the time of pressurization is remarkably restricted, and therefore, the liquid return preventing effect is excellent.

  In the water-repellent enhanced region, “without the hydrophilic portion 51 interposed” means that the water-repellent portion 50 on one surface and the water-repellent portion 50 on the other surface in the planar projection of the bodily fluid backflow prevention layer 5. In the meantime, not only a form in which the hydrophilic part 51 does not exist at all, but also a form in which only a part of the hydrophilic part 51 exists unintentionally due to a processing error or the like in the manufacturing process of the body fluid backflow prevention layer 5 is included. More specifically, the area of the water repellent portion 50 of the skin facing surface 5a of the body fluid backflow prevention layer 5 corresponds to the water repellent portion 50 (overlapping in the planar projection of the layer 5). The hydrophilic portion 51 of the skin facing surface 5a corresponding to the water repellent portion 50 (overlapping in the planar projection of the layer 5) is 90% or more of the area 51 and the area of the water repellent portion 50 of the non-skin facing surface 5b. When the surface area is 90% or more, the hydrophilic portion 51 is not interposed between the water-repellent portion 50 on one surface and the water-repellent portion 50 on the other surface in the planar projection of the bodily fluid backflow prevention layer 5. It can be said. When the area of the water repellent part 50 on one surface is 100% of the area of the corresponding hydrophilic part, the water repellent part 50 on one surface and the repellent surface on the other surface in the planar projection of the bodily fluid backflow prevention layer 5. This is a form in which the hydrophilic part 51 does not exist at all between the water part 50.

  Further, the body fluid backflow prevention layer 5 shown in FIGS. 3 and 4 has a one-to-one correspondence with the hydrophilic portion 51 on the other surface with respect to the water repellent portion 50 on one surface and the hydrophilic portion 51 on the other surface. The water repellent part 50 on the other surface has a one-to-one correspondence, and the water repellent part 50 (hydrophilic part 51) on one surface in the planar projection of the bodily fluid backflow prevention layer 5 and the other surface corresponding thereto Although the hydrophilic portion 51 (water repellent portion 50) is completely coincident with the water repellent enhanced region, not only the form shown in FIG. 3 and FIG. The entire hydrophilic portion 51 of the surface is included in the water-repellent portion 50 of the other surface corresponding thereto, that is, the water-repellent portion 50 and the hydrophilic portion that are in a corresponding relationship (overlapping in the planar projection of the layer 5) A configuration in which the water repellent part 50 is larger than the part 51 is also included. Such a relatively large water-repellent part 50 can more effectively prevent liquid return since the formation of a flow path in the layer thickness direction of the body fluid is further restricted during pressurization.

It is preferable that the bodily fluid backflow prevention layer 5 has the water-repellent reinforcing region at least in the crotch part B (excretion part facing part D). That is, it is preferable that at least the entire portion located in the crotch part B (excretion part facing part D) in the body fluid backflow prevention layer 5 is the water repellent enhancement region. Of course, the whole body fluid backflow prevention layer 5 may be the water-repellent enhanced region. The area of the water-repellent enhanced region is preferably 20% or more, more preferably 30% or more with respect to the area of the body fluid backflow prevention layer 5. The area of the water-repellent reinforcing area is preferably 7000 mm ² or more, more preferably 12000 mm ² or more.

  The body fluid backflow prevention layer 5 is usually manufactured by forming the water-repellent part 50 on a part (both surfaces of the base material) of a base material (hydrophilic nonwoven fabric or the like) made of a hydrophilic material. That is, the bodily fluid backflow prevention layer 5 is obtained by including a hydrophilic base material and the water repellent part 50. Therefore, in the bodily fluid backflow prevention layer 5 manufactured by such a manufacturing method, the part other than the water repellent part 50 is a hydrophilic part 51 made of a hydrophilic material and has hydrophilicity (has water repellency. It has a fluid absorption capacity.

  The body fluid backflow prevention layer 5 preferably includes a hydrophilic nonwoven fabric obtained by subjecting a nonwoven fabric to a hydrophilic treatment with a surfactant. That is, as a preferable example of the bodily fluid backflow prevention layer 5, a water-repellent part 50 formed on a part of such a hydrophilic nonwoven fabric can be cited. Examples of the hydrophilic nonwoven fabric include an air-through nonwoven fabric, an airlaid nonwoven fabric, a needle punched nonwoven fabric, a spunlace nonwoven fabric, a spunbond nonwoven fabric, and a melt blown nonwoven fabric.

  Particularly preferred as the hydrophilic nonwoven fabric constituting the bodily fluid backflow prevention layer 5 is a hydrophilic dry nonwoven fabric. The dry non-woven fabric here means a non-woven fabric produced by one or two or more bonding methods using a card in a spinning process or laminating fibers dispersed in air in a sheet shape. The hydrophilic dry nonwoven fabric includes a hydrophilic dry nonwoven fabric because it is bulky and thicker than other nonwoven fabrics, such as wet nonwoven fabrics or spunbond, melt blown, flash spinning, and other directly-spun nonwoven fabrics. The body fluid backflow prevention layer 5 is excellent in liquid permeability because it has a sufficient thickness and a wide flow path when there is no pressure as shown in FIG. Other non-woven fabrics such as wet non-woven fabrics have a relatively thin thickness even when there is no pressure applied, and the flow path is narrow. It becomes difficult to suppress liquid return. From the viewpoint of the balance between the liquid permeability when no pressure is applied and the ease of compressive deformation during pressure, the hydrophilic dry nonwoven fabric constituting the body fluid backflow prevention layer 5 is preferably a chemical bond type, thermal type, or the like. A nonwoven fabric obtained by a bonding method such as a bond type, a needle punch type, or a spunlace type, and a hydrophilic air-through nonwoven fabric is particularly preferable.

  As the hydrophilic material constituting the bodily fluid backflow prevention layer 5, hydrophilic fibers are preferably used. Specifically, for example, hydrophilic synthetic fibers such as polyvinyl alcohol fibers and polyacrylonitrile fibers; polyethylene terephthalate (PET) fibers, Examples thereof include hydrophilized synthetic fibers obtained by hydrophilizing a water-repellent synthetic fiber with a surfactant, such as polyethylene (PE) fiber, polypropylene (PP) fiber, and polyester fiber. Two or more kinds can be used in combination. The hydrophilic fiber may be a single fiber, a core-sheath type or side-by-side type composite fiber, a split fiber, a modified cross-section fiber, or the like. These hydrophilic fibers can be used singly or in combination of two or more.

  In addition to these hydrophilic fibers (fibers that do not inherently have hydrophilicity), the bodily fluid backflow prevention layer 5 may be made of fibers having inherent hydrophilicity, for example, natural fibers such as wood pulp and cotton. Cellulose fibers; Regenerated cellulose fibers such as rayon fibers; Mercerized pulp obtained by mercerizing wood pulp; Use of bulky cellulose fibers such as crosslinked cellulose fibers obtained by crosslinking intramolecular and intermolecular molecules of cellulose fibers You can also. In the case of using fibers having these hydrophilic properties, the fibers are not limited to the form of a nonwoven fabric, and can be used by molding into a dry web in which fibers dispersed in the air are laminated into a sheet or paper. Examples of commercially available mercerized pulp include “FILTRANIER” (trade name) manufactured by ITT Rayonier Inc. and “POROSANIER” (trade name) manufactured by the same company. Examples of commercially available crosslinked cellulose fibers include Weyerhaeuser. “High Bulk Additive” (trade name) manufactured by Paper Co. By using the bulky cellulose fiber, the body fluid backflow prevention layer 5 becomes bulky, and thereby the liquid permeability of the body fluid backflow prevention layer 5 can be improved.

  The fiber diameter of the constituent fibers (hydrophilic fibers) of the body fluid backflow prevention layer 5 is preferably 3.3 dtex or more, more preferably 4.4 dtex or more, from the viewpoint of making the body fluid backflow prevention layer 5 relatively bulky and bulky. And preferably it is 10 dtex or less, More specifically, Preferably it is 3.3-10 dtex, More preferably, it is 4.4-10 dtex. The measurement of the fiber diameter is performed according to a conventional method using observation with a scanning electron microscope, and the average value of 20 or more fibers is defined as the fiber diameter of the fiber.

The basis weight of the body fluid backflow prevention layer 5 is preferably 15 g / m ² or more, more preferably 25 g / m ² or more, and preferably 60 g / m ² or less, more preferably 45 g / m ² or less, more specifically. Is preferably 15 to 60 g / m ² , more preferably 25 to 45 g / m ² .
The thickness of the bodily fluid backflow prevention layer 5 under a 0.5 g / m ² load is preferably 0.5 mm or more, more preferably 1 mm or more, and preferably 3 mm or less, more preferably 2 mm or less, more specifically, Preferably it is 0.5-3 mm, More preferably, it is 1-2 mm. The reason for applying a load of 0.5 g / m ^{2 in} the measurement of the thickness of the body fluid backflow prevention layer is to suppress variation in the measured value, and the thickness under the load of 0.5 g / m ² is under no load. The thickness is substantially the same.

  The water repellent part 50 has water repellency, does not have a body fluid absorbing ability, and is made of a water repellent material. Examples of the water-repellent material constituting the water-repellent part 50 include 1) a film material made of synthetic resin having water repellency, 2) a web or non-woven fabric made of the synthetic resin as a fiber raw material and not hydrophilized, 3) A web or non-woven fabric obtained by stacking fibers having hydrophobic surfaces obtained by treating hydrophilic fibers with a surfactant or the like. Examples of the nonwoven fabric that can be used as the water-repellent material constituting the water-repellent portion 50 include, for example, a spunbond nonwoven fabric, a spunbond-meltblown (SM) nonwoven fabric, a spunbond-meltblown-spunbond (SMS) nonwoven fabric, and a spunbond-meltblown. -Melt blown-spun bond (SMMS) nonwoven fabric etc. are mentioned. Among these water repellent materials, the film material 1) is preferably used as the water repellent portion 50 because it exhibits high water repellency and can more effectively prevent liquid return.

  In the production of the body fluid backflow prevention layer 5, as a method of forming the water repellent part 50 on a part (both sides of the base material) of a base material (hydrophilic dry nonwoven fabric etc.) made of a hydrophilic material, for example, a) A method of adhering the water-repellent material (film material or the like) to a predetermined portion on both sides of a base material (hydrophilic air-through nonwoven fabric or the like) with an adhesive such as a hot-melt adhesive; b) the base material (hydrophilic A method of superimposing the water-repellent material (water-repellent web etc.) on a part of a dry web, etc., and forming both together (non-woven fabric), c) a method of applying a water repellent to the substrate Can be mentioned. In the method c), examples of the water repellent include paraffinic, pyridinium salt type, methylolamide type, ethylene urea type, silicone type, chromic chloride type, and fluorine compound type, and are not particularly limited. Also, the application method of the water repellent is not particularly limited, and a known method used when applying this type of water repellent can be used. A method can also be used. In particular, the screen printing method and the gravure coating method are preferable in the present invention as a method for applying a water repellent agent to a base material (a method for producing a body fluid backflow prevention layer) because a low coating amount and a pattern-like pattern can be applied. Used.

  In order to make the above-described effects of the bodily fluid backflow prevention layer 5 more reliable, in the planar projection from the skin facing surface 5a or the non-skin facing surface 5b of the bodily fluid backflow preventing layer 5, one surface 5a ( Alternatively, the water repellent portions 50 on the surface 5b) and the water repellent portions 50 on the other surface 5b (or the surface 5a) are preferably arranged alternately in the vertical direction X or the horizontal direction Y. 3 and 4, the water repellent part 50 on one surface and the water repellent part 50 on the other surface are alternately arranged in the lateral direction Y.

  6-9, the skin opposing surface 5a side of other embodiment of the bodily fluid backflow prevention layer based on this invention is illustrated. Regarding other embodiments to be described later, components different from those of the above-described embodiment (body fluid backflow prevention layer 5) are mainly described, and the same components are denoted by the same reference numerals and description thereof is omitted. The description of the above embodiment is appropriately applied to components that are not particularly described. 6 to 9 show only the skin-facing surface of the body fluid backflow prevention layer, and the non-skin facing surface of the body fluid backflow prevention layer is not shown, but unless otherwise specified, Are provided with a water repellent portion 50 and a hydrophilic portion 51 so as to satisfy the above-described relationship with respect to the skin facing surface 5a shown in FIGS. Further, the X direction and the Y direction in FIGS. 6 to 9 coincide with the vertical direction X and the horizontal direction Y in FIG. 1, respectively.

  In the body fluid backflow prevention layers 5A to 5J (see FIGS. 6 to 9), the total area S1 of the water repellent portion 50 of the skin facing surface 5a is the water repellency of the non-skin facing surface 5b of the body fluid backflow preventing layers 5A to 5J. It is smaller than the total area S2 of the part 50. With such a configuration (area S1 <area S2), the body fluid flows from the hydrophilic portion 51 widely present on the skin facing surface 5a side of the body fluid backflow prevention layers 5A to 5E to the inside of the body fluid backflow prevention layers 5A to 5E. It will move quickly. Moreover, the remaining of the bodily fluid in the position close | similar to a wearer's skin on the water repellent part 50 of the skin opposing surface 5a can be suppressed effectively.

  From the viewpoint of ensuring the above-described effects, the ratio of the total area S1 of the water repellent portion 50 of the skin facing surface 5a to the total area S2 of the water repellent portion 50 of the non-skin facing surface 5b (S1 / S2) is preferably 0.5 or more, more preferably 0.6 or more, and preferably 1 or less, more preferably 0.8 or less, more specifically preferably 0.5 to 1, and more preferably Is 0.6 to 0.8.

  Further, as shown in the body fluid backflow prevention layers 5A to 5E (see FIG. 6), 5I (see FIG. 8), and 5J (see FIG. 9), the hydrophilic portions 51 of the skin facing surface 5a and the non-skin facing surface 5b are vertically The length Lx in the direction X is preferably longer than the length Ly in the horizontal direction Y. With such a configuration (length Lx> length Ly), bodily fluids such as urine are easily diffused in the vertical direction X in each hydrophilic portion 50 of the skin facing surface 5a, thereby spreading the bodily fluids in the lateral direction Y. It is suppressed and side leakage is effectively prevented. Moreover, the bodily fluid transferred from the skin facing surface 5a to the inside of the body fluid backflow prevention layers 5A to 5E, 5I, 5J is caused by the water repellent portion 50 (not shown in FIGS. 6, 8, and 9) of the non-skin facing surface 5b. By being repelled, the transfer speed (flow velocity) of the body fluid to the non-skin facing surface 5b side due to excretion is reduced, so that the body fluid is more easily diffused in the vertical direction X along the hydrophilic portion 51. Absorption of body fluids in a wide range of can be promoted, and as a result, the utilization efficiency of the part located in the longitudinal direction X of the absorbent body 4 (absorbent core 40) can be improved, and the crotch part B (excretion part facing part D) ) Can suppress a phenomenon in which body fluid remains (liquid accumulation). Furthermore, excessive diffusion of body fluid in the lateral direction Y of the absorbent body 4 can be suppressed, and as a result, liquid leakage in the lateral direction Y at the crotch part B can be prevented.

  From the viewpoint of more surely exhibiting the above-described effects, the hydrophilic portion 51 of each of the skin facing surface 5a and the non-skin facing surface 5b has a length Lx in the vertical direction X and a length Ly in the horizontal direction Y. The ratio (Lx / Ly) is preferably 2 or more, more preferably 5 or more, and preferably 700 or less, more preferably 400 or less, more specifically preferably 2 to 700, more preferably 5 to 400. It is.

In the body fluid backflow prevention layer 5I (see FIG. 8), the hydrophilic portion 51 of the skin facing surface 5a is open to the edge of the body fluid backflow prevention layer 5I and is not surrounded by the water repellent portion 50. Is more likely to occur and is superior to the bodily fluid backflow prevention layer 5J (see FIG. 9) in terms of utilization efficiency of the absorbent body 4 (absorbent core 40). Moreover, in the bodily fluid backflow prevention layer 5I, in particular, the area of the hydrophilic portion 51 of the skin facing surface 5a is reduced (the area becomes 500 mm ² or less), and the absorption speed is prevented from being slowed.

  In the body fluid backflow prevention layer 5A (see FIG. 6 (a)), the body fluid backflow prevention layer 5B (see FIG. 6 (b)) and the body fluid backflow prevention layer 5C (see FIG. 6 (c)), the skin facing surface 5a. A plurality of water repellent parts 50 each having a straight line (rectangular shape) in plan view extending in the vertical direction X and a plurality of hydrophilic parts 51 having a straight line shape (rectangular shape) in plan view extending in the same direction are provided. The hydrophilic portions 51 are alternately arranged in the lateral direction Y.

  In the bodily fluid backflow prevention layer 5D (see FIG. 6D), the water repellent portion having a straight line shape (rectangular shape) in plan view extending in the intersecting direction intersecting both the vertical direction X and the horizontal direction Y on the skin facing surface 5a. 50 and a plurality of hydrophilic portions 51 each having a straight line shape (rectangular shape) in a plan view extending in the same direction, and the water repellent portions 50 and the hydrophilic portions 51 are alternately arranged in a direction perpendicular to the intersecting direction. Yes. In the body fluid backflow prevention layer 5D, the angle α formed with the lateral direction Y of the water repellent part 50 or the hydrophilic part 51 is preferably 45 ° or more, more preferably 60 ° or more, and preferably 135 ° or less, more preferably It is 120 ° or less, more specifically, preferably 45 to 135 °, and more preferably 60 to 120 °.

  In the body fluid backflow prevention layer 5E (see FIG. 6E), a plurality of water-repellent portions 50 having a rectangular shape (rectangular shape) in a plan view are arranged in a discrete pattern on the skin facing surface 5a. The part other than the water repellent part 50 in 5 a is a hydrophilic part 51. The plurality of water repellent parts 50 are arranged in a staggered manner. Here, the zigzag pattern has a plurality of water repellent portions 50 arranged at equal intervals in one direction (vertical direction X), and a plurality of rows are arranged in a direction perpendicular to the one direction (horizontal direction Y). In addition, an arrangement in which the water-repellent portions 50 are shifted from each other in two adjacent rows in a direction (lateral direction Y) orthogonal to the one direction. Between the rows of the water-repellent portions 50 that are adjacent to the horizontal direction Y and extend in the vertical direction X, a gap made of the hydrophilic portion 51 is provided, and each water-repellent portion 50 is surrounded by the hydrophilic portion 51. .

  Further, like the body fluid backflow prevention layers 5A to 5E (see FIG. 6), the body fluid backflow prevention layers 5A to 5E are repelled on any one imaginary straight line P that crosses the skin facing surface 5a in the lateral direction Y. It is preferable that the water part 50 is arranged. With such a configuration, the body fluid that has passed through the top sheet 2 and has reached the center of the skin facing surface 5a of the body fluid backflow prevention layers 5A to 5E (the center of the crotch B in the lateral direction Y) passes through the skin facing surface 5a. The body fluid always passes through the water-repellent part 50 until it diffuses in the lateral direction Y and reaches the end in the lateral direction Y of the body fluid backflow prevention layer, so that the body fluid diffuses in the lateral direction Y. Is more effectively suppressed.

  Moreover, in the bodily fluid backflow prevention layers 5A to 5E, as shown in FIG. 6, the hydrophilic portion 51 of the skin facing surface 5a is open to the edge of the bodily fluid backflow prevention layers 5A to 5E. The backflow prevention layers 5A to 5E are in contact with either the longitudinal direction X or the lateral direction Y ends. With such a configuration, the body fluid is easily diffused along the hydrophilic portion 51 on the skin facing surface 5a, whereby the utilization efficiency of the absorbent body 4 (absorbent core 40) can be further improved.

  Although the present invention has been described above, the present invention is not limited to the above-described embodiments and can be modified as appropriate. For example, in the above-described embodiment, body fluid backflow prevention is provided in which the water-repellent part 50 is arranged in a predetermined pattern on the entire skin facing surface and non-skin facing surface of a base material (sublayer) made of a hydrophilic dry nonwoven fabric or the like. The layer 5 covered the whole area of the skin facing surface of the absorbent body 4, but as another form, the body fluid backflow prevention layer 5 covers only a part of the skin facing surface of the absorbent body 4 (hereinafter referred to as the form). (also referred to as α). In form (alpha), the said base material itself which comprises the bodily fluid backflow prevention layer 5 is smaller than the absorber 4, and does not have the magnitude | size which can coat | cover the whole skin opposing surface of the absorber 4. FIG. In the form α, the bodily fluid backflow prevention layer 5 is preferably arranged so as to cover at least the skin facing surface of the absorbent body 4 in the crotch part B (excretion part facing part D). For example, when the body fluid backflow prevention layer 5 is disposed only in the crotch B (excretion portion facing portion D) and not disposed in the abdominal portion A and the dorsal portion C, the crotch portion B (excretion portion facing portion) that easily returns to the liquid. In D), fluid return is effectively suppressed by the body fluid backflow prevention layer 5, and the body fluid backflow prevention layer 5 (the base material) does not exist in the abdominal part A and the back side part. Compared with excellent thinness and softness and no water-repellent part, body fluid is absorbed quickly.

  Moreover, in the said embodiment, the water repellent part 50 was distribute | arranged by the predetermined pattern in the whole region of each skin opposing surface and non-skin opposing surface of the said base material, and this whole base material was a bodily fluid backflow prevention layer. However, in the present invention, only a part of the base material is a bodily fluid backflow prevention layer in which water repellent parts are arranged in a predetermined pattern on both sides thereof, that is, the base material and the bodily fluid backflow prevention layer Are also included that are continuous and integrated in the plane direction (hereinafter also referred to as form β). As an example of the form β, the base material has a size that can cover the entire area of the skin-facing surface of the absorbent body, and only the portion located in the crotch part B (excretion part facing part D) of the base material is, It is a bodily fluid backflow prevention layer in which water repellent parts are arranged in a predetermined pattern over the entire areas of the skin facing surface and the non-skin facing surface, and the other part of the base material (for example, the ventral side A, the back side) Part C) includes a form having no water repellent part. The effect similar to that of the above-described form α is also obtained by the form β.

  Moreover, in the said embodiment, although the core wrap sheet | seat 41 was one sheet, it is two sheets in total, one sheet | seat which coat | covers the skin opposing surface of the absorptive core 40, and another sheet | seat which coat | covers a non-skin opposing surface. There may be. Further, the absorbent article of the present invention is not limited to a deployable disposable diaper, and broadly includes articles used to absorb body fluids (urine, menstrual blood, loose stool, sweat, etc.) discharged from the human body, and is a pants type. Disposable diapers, sanitary napkins, sanitary shorts, and the like are also included. The following additional notes are disclosed with respect to the embodiment of the present invention described above.

<1>
It has an absorptive core that absorbs and holds excreted bodily fluids, and has an abdominal side portion disposed on the abdomen side of the wearer, a back side portion disposed on the back side, and a crotch portion positioned therebetween. An absorbent article having a longitudinal direction extending from the abdominal side part to the back side part via the crotch part and a lateral direction perpendicular thereto,
On the skin facing surface side of the absorbent core, a liquid-permeable body fluid backflow prevention layer that prevents transfer of body fluid from the absorbent core to the wearer's skin side is disposed,
The body fluid backflow prevention layer comprises a dry nonwoven fabric or a dry web,
A water repellent part and a hydrophilic part are arranged on the skin facing surface and the non-skin facing surface of the body fluid backflow prevention layer, respectively.
The hydrophilic portion is located at a site corresponding to the water repellent portion of the non-skin facing surface of the bodily fluid backflow prevention layer in the skin facing surface of the bodily fluid backflow prevention layer,
An absorptive article in which the hydrophilic part is located in a portion corresponding to the water repellent part of the skin facing surface of the bodily fluid backflow preventing layer in the non-skin facing surface of the bodily fluid backflow preventing layer.
<2>
In the planar projection from the skin facing surface or the non-skin facing surface, the body fluid backflow prevention layer has the hydrophilic portion interposed between the water repellent portion on one surface and the water repellent portion on the other surface. The absorbent article according to <1>, wherein the absorbent article has a water-repellent reinforced region.

<3>
The area of the water repellent part of the skin facing surface of the bodily fluid backflow prevention layer corresponds to the water repellent part (which overlaps in the planar projection of the body fluid backflow preventing layer) of the hydrophilic surface of the non-skin facing surface of the body fluid backflow preventing layer 90% or more of the area of the part, and the area of the water repellent part of the non-skin facing surface corresponds to the water repellent part (overlapping in the planar projection of the body fluid backflow prevention layer) the skin of the body fluid backflow prevention layer The absorbent article according to <2>, wherein the absorbent article is 90% or more of the area of the hydrophilic portion on the opposite surface.
<4>
The area of the water repellent part on one surface of the bodily fluid backflow prevention layer is 100% of the area of the hydrophilic part corresponding thereto, and in the plane projection of the body fluid backflow prevention layer, The absorbent article according to <2> or <3>, wherein the hydrophilic portion is not present between the water repellent portion on the other surface.
<5>
In the planar projection of the bodily fluid backflow prevention layer, the water-repellent part (the hydrophilic part) on one surface and the hydrophilic part (the water-repellent part) on the other surface corresponding to this completely coincide with each other. The absorbent article according to any one of <2> to <4>.
<6>
In the planar projection of the bodily fluid backflow prevention layer, the entire hydrophilic portion on one surface is included in the water-repellent portion on the other surface corresponding to this or is in a corresponding relationship with each other (the bodily fluid) The absorbent article according to any one of <2> to <4>, wherein the water repellent portion and the hydrophilic portion (which overlap in a planar projection of the backflow prevention layer) are larger.
<7>
The absorptive article according to any one of <2> to <6>, wherein the body fluid backflow prevention layer has the water-repellent reinforcing region at least in the crotch portion (excretion portion facing portion).
<8>
The absorbent article according to any one of <2> to <7>, wherein the whole body fluid backflow prevention layer is the water repellent enhanced region.

<9>
In the planar projection from the skin facing surface or the non-skin facing surface of the body fluid backflow prevention layer, the water repellent portion on one surface and the water repellent portion on the other surface are alternately arranged in the vertical direction or the horizontal direction. The absorbent article according to any one of <1> to <8>.
<10>
The bodily fluid backflow prevention layer 5 includes a base material on which the water repellent part is provided, and the base material is any one of the above items <1> to <9> made of a hydrophilic dry nonwoven fabric having a single layer structure. Or an absorbent article according to claim 1.
<11>
<1> wherein the dry nonwoven fabric is a nonwoven fabric obtained by one bonding method selected from the group consisting of a chemical bond type, a thermal bond type, a needle punch type, and a spunlace type, or a hydrophilic air-through nonwoven fabric. The absorbent article according to any one of ~ <10>.

<12>
A surface sheet that can come into contact with the skin of the wearer when worn is disposed on the skin facing surface side of the absorbent core, and the body fluid backflow prevention layer is disposed between the surface sheet and the absorbent core. The absorbent article according to any one of <1> to <11>.
<13>
<1> to <12>, in which the total area of the water repellent part of the skin-facing surface of the body fluid backflow prevention layer is smaller than the total area of the water repellent part of the non-skin facing surface of the body fluid backflow prevention layer. The absorbent article according to any one of 1.
<14>
The ratio (S1 / S2) of the total area S1 of the water repellent part of the skin facing surface of the body fluid backflow prevention layer to the total area S2 of the water repellent part of the non-skin facing surface of the body fluid backflow prevention layer is preferably The absorbent article according to the above <12> or <13>, which is 0.5 or more, more preferably 0.6 or more, and preferably 1 or less, more preferably 0.8 or less.

<15>
The absorptivity according to any one of <1> to <14>, wherein the hydrophilic portion is disposed on a longitudinal center line that bisects the skin facing surface of the body fluid backflow prevention layer in the lateral direction. Goods.
<16>
The horizontal length of the hydrophilic portion of the portion of the body fluid backflow prevention layer that overlaps with the vertical center line is the same as that of the water repellent portion located on both sides of the hydrophilic portion. The absorbent article according to <15>, which is longer than the above.
<17>
Absorption according to any one of <1> to <16>, wherein the hydrophilic portion of each of the skin facing surface and the non-skin facing surface of the body fluid backflow prevention layer has a longitudinal length longer than a lateral length. Sex goods.
<18>
In the hydrophilic part of each of the skin facing surface and the non-skin facing surface of the body fluid backflow prevention layer, the ratio (Lx / Ly) of the longitudinal length Lx to the lateral length Ly is preferably 2 or more, The absorbent article according to <17>, preferably 5 or more, and preferably 700 or less, more preferably 400 or less.

<19>
The absorption according to any one of <1> to <18>, wherein the water repellent part is arranged on any one imaginary straight line transversely across the skin-facing surface of the body fluid backflow prevention layer. Sex goods.
<20>
The absorbent article according to any one of <1> to <19>, wherein the hydrophilic portion on the skin-facing surface of the bodily fluid backflow prevention layer is open to an edge of the bodily fluid backflow prevention layer.
<21>
Any one of <1> to <20>, wherein the entire skin-facing surface of the absorbent body (the skin-facing surface of the core wrap sheet on the skin-facing surface side of the absorbent core) is covered with the body fluid backflow prevention layer. Absorbent article as described in 1.
<22>
The absorbent article according to any one of <1> to <21>, wherein the portion (inside) of the body fluid backflow prevention layer other than the surface layer portion is composed of only the hydrophilic portion and is hydrophilic.
<23>
The body fluid backflow prevention layer has liquid permeability, and the water absorptivity is preferably less than 15 seconds, and more preferably less than 10 seconds, according to any one of <1> to <22>. Goods.

<24>
<1> wherein the hydrophilic portion has a droplet residual ratio of 30% or less, more preferably 20% or less, and particularly preferably 0% when 30 seconds have elapsed after the transfer of the droplet measured by the droplet method. The absorbent article according to any one of ~ <23>.
<25>
The water repellent part has a residual ratio of more than 80% after 30 seconds from the drop transfer measured by the drop method, or 1 minute after the drop transfer measured by the drop method The absorbent article according to any one of <1> to <24>, wherein the remaining droplet rate at the time is 100%.
<26>
Any of <1> to <25>, wherein the body fluid backflow prevention layer is obtained by forming the water-repellent part on a part of the base material (both sides of the base material) made of a hydrophilic material. 2. The absorbent article according to 1.

<27>
The basis weight of the body fluid backflow prevention layer is preferably 15 g / m ² or more, more preferably 25 g / m ² or more, and preferably 60 g / m ² or less, more preferably 45 g / m ² or less <1 The absorbent article according to any one of> to <26>.
<28>
The thickness of the body fluid backflow prevention layer under a load of 0.5 g / m ² is preferably 0.5 mm or more, more preferably 1 mm or more, and preferably 3 mm or less, more preferably 2 mm or less. The absorbent article according to any one of <27>.
<29>
The absorbent article according to any one of <1> to <28>, wherein the water repellent material constituting the water repellent part is at least one selected from the group consisting of the following 1) to 3).
1) A synthetic resin film material having water repellency.
2) A web or non-woven fabric using the synthetic resin as a fiber material and not hydrophilized.
3) A web or non-woven fabric obtained by stacking hydrophobic fibers on the surface, obtained by treating hydrophilic fibers with a surfactant.
<30>
The body fluid backflow prevention layer is obtained by forming the water-repellent part on a part of the base material (both sides of the base material) made of a hydrophilic material, and the water-repellent part on a part of the base material. The absorbent article according to any one of the above items <1> to <29>, which is one or more selected from the group consisting of a) to d) below.
a) A method in which the water-repellent material is adhered to a predetermined portion on both surfaces of the base material with an adhesive.
b) A method of superimposing a water-repellent material on a part of the base material and forming both together or forming a nonwoven fabric.
c) A method of applying a water repellent to the substrate.

<31>
On the skin-facing surface of the body fluid backflow prevention layer, a plurality of linear portions (rectangular shape) in the vertical direction extending in the vertical direction and a plurality of hydrophilic portions in the linear shape (rectangular shape) in the planar direction extending in the same direction are arranged. The absorbent article according to any one of <1> to <30>, wherein the water repellent part and the hydrophilic part are alternately arranged in a lateral direction.
<32>
A straight line (rectangular shape) in plan view extending in the same direction as the water repellent part in a straight line shape (rectangular shape) in plan view extending in the intersecting direction intersecting both the longitudinal direction and the lateral direction on the skin facing surface of the body fluid backflow prevention layer Any one of the above <1> to <30>, wherein a plurality of the hydrophilic portions are arranged in the direction orthogonal to the intersecting direction. Absorbent article as described in 1.
<33>
The water repellent portions having a quadrangular shape (rectangular shape) in plan view are arranged in a staggered pattern on the skin-facing surface of the body fluid backflow preventing layer, and each water repellent portion is surrounded by the hydrophilic portion. The absorbent article according to any one of> to <32>.
<34>
The body fluid backflow prevention layer is the absorbent article according to any one of <1> to <33>, in which a body fluid flow path is formed inside when no pressure is applied.

  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]
In accordance with a conventional method, a deployable disposable diaper having the same basic configuration as the diaper 1 shown in FIGS. 1 to 3 was produced.
An air-through nonwoven fabric with a basis weight of 25 g / m ² was used as the top sheet, and a liquid-impermeable and moisture-permeable polyethylene resin film (calcium carbonate blended) with a basis weight of 20 g / m ² was used as the back sheet.
The absorbent core, as those obtained by holding the particulate water-absorbing polymer in the fiber aggregate, fluff pulp 200 g / m ² and the water-absorbing polymer 186 g / m ² total basis consisting homogeneous mixture of a weight 386 g / m ² An absorbent core was used. The full length (longitudinal direction) of the absorbent core was 360 mm, and the full length (maximum length) in the lateral direction (width direction) was 110 mm. A liquid-permeable tissue paper having a basis weight of 13.5 g / m ² was used as the core wrap sheet, and the entire surface of the absorbent core was covered with the core wrap sheet to obtain an absorbent body.
As the body fluid backflow prevention layer, a hydrophilic air-through non-woven fabric (hydrophilic dry non-woven fabric) in which the surface of the constituent fiber is hydrophilized with a surfactant and a water-repellent part formed thereon was used. This air-through nonwoven fabric (body fluid backflow prevention layer) has a rectangular shape in plan view with a total length of 240 mm in the longitudinal direction (longitudinal direction) and a total length of 75 mm in the lateral direction (width direction), and has a basis weight of 40 g / m ² . The thickness under a load of 5 g / m ² was 1.35 mm. The constituent fibers of this air-through nonwoven fabric were core-sheath type composite fibers in which the core component resin was polyester and the sheath component resin was polyethylene, and the fiber diameter was 4.4 dtex. A plurality of strip-shaped polyethylene resin films (water repellent material) having a basis weight of 20 g / m ² and a lateral direction (width direction) length of 15 mm are shown in FIGS. 3 and 6A on both sides of the air-through nonwoven fabric. A body fluid backflow prevention layer was obtained by bonding with a striped pattern using an adhesive and forming a plurality of linear water repellent portions extending over the entire length in the longitudinal direction (longitudinal direction) of each side of the air-through nonwoven fabric. . As a result of measuring the droplet remaining rate of this bodily fluid backflow prevention layer by the above method, the droplet remaining rate of the hydrophilic portion was 30%, and the droplet remaining rate of the water repellent portion was 100%. The body fluid backflow prevention layer was disposed between the top sheet and the absorbent body so as to cover the entire length of the crotch part in the vertical direction.

[Comparative Example 1]
A deployable disposable diaper was produced in the same manner as in Example 1, except that the water-repellent part was not formed on the air-through nonwoven fabric and the air-through nonwoven fabric was used as it was as a body fluid backflow prevention layer.

[Comparative Example 2]
An unfolded disposable diaper was produced in the same manner as in Example 1 except that a water repellent part having a pattern shown in FIG. 6 (a) was formed only on the skin-facing surface of the air-through nonwoven fabric as the body fluid backflow prevention layer. .

[Comparative Example 3]
Example 1 except that the polyethylene resin film was adhered to the entire skin facing surface of the air-through nonwoven fabric, and a water repellent portion was formed on the entire skin facing surface as the body fluid backflow prevention layer. An unfolded disposable diaper was prepared.

[Evaluation]
About the diaper of each Example and the comparative example, the liquid return amount was evaluated by the following method. The results are shown in Table 1 below.

<Measurement method of liquid return amount>
The diaper to be measured was spread in a flat shape and placed horizontally with the skin facing surface side (surface sheet side) facing upward, and 30 g of artificial urine was injected twice at a flow rate of 5 g / sec (total of 60 g injection). . After the first injection, the second injection was performed after 5 minutes. The place where the artificial urine was injected was the central portion in the horizontal direction at a position spaced 130 mm inward in the vertical direction from the end on the ventral side in the vertical direction (longitudinal direction) of the absorber. After the second artificial urine was injected into the diaper, this was left for 10 minutes, and then 10 mm square filter paper (ADVANTEC hard filter paper 4A) was cut into 7 cm square and 10 sheets were stacked in the diaper. The artificial urine that was absorbed and held in the diaper (absorbent core) was absorbed into the diaper (absorbent core) by applying 7 kPa from the top of the filter paper for 1 minute. Thereafter, the weight of the filter paper that absorbed artificial urine was measured. The weight of the filter paper before absorption was subtracted from this weight, and the weight of the artificial urine absorbed by the filter paper was calculated as the liquid return amount. The smaller the liquid return amount, the less liquid remains on the top sheet, and the higher the liquid return prevention property, the higher the evaluation. The composition of artificial urine is as follows. 1.94% by mass of urea, 0.7954% by mass of sodium chloride, 0.11058% by mass of magnesium sulfate (septahydrate), 0.06208% by mass of calcium chloride (dihydrate), 0.19788% by mass of potassium sulfate , Polyoxyethylene lauryl ether 0.0035 mass% and ion-exchanged water (remaining amount).

  As shown in Table 1, Example 1 was a diaper that had less liquid return than each Comparative Example and hardly caused liquid return. On the other hand, in Comparative Example 1, the water repellent part is not disposed on either the skin facing surface or the non-skin facing surface of the body fluid backflow prevention layer, and Comparative Example 2 is the skin facing surface of the body fluid backflow prevention layer. Although the water repellent part was disposed on the surface, the water repellent part was not disposed on the non-skin facing surface. In Comparative Example 3, since the whole area of the skin-facing surface of the body fluid backflow prevention layer is a water-repellent part, the artificial urine injected was hardly absorbed by the absorbent core in the first place, and measurement was impossible.

1 disposable diaper (absorbent article)
2 Top sheet 3 Back sheet 4 Absorber 40 Absorbent core 41 Core wrap sheet 5, 5A-5J Body fluid backflow prevention layer 5a Skin facing surface 5b of body fluid backflow prevention layer Non-skin facing surface 50 of body fluid backflow prevention layer Water repellent part 51 Hydrophilic part A Ventral part B Crotch part C Dosal part D Excretion part opposite part

Claims (9)

It has an absorptive core that absorbs and holds excreted bodily fluids, and has an abdominal side portion disposed on the abdomen side of the wearer, a back side portion disposed on the back side, and a crotch portion positioned therebetween. An absorbent article having a longitudinal direction extending from the abdominal side part to the back side part via the crotch part and a lateral direction perpendicular thereto,
On the skin facing surface side of the absorbent core, a liquid-permeable body fluid backflow prevention layer that prevents transfer of body fluid from the absorbent core to the wearer's skin side is disposed,
The body fluid backflow prevention layer comprises a dry nonwoven fabric or a dry web,
A water repellent part and a hydrophilic part are arranged on the skin facing surface and the non-skin facing surface of the body fluid backflow prevention layer, respectively.
The hydrophilic portion is located at a site corresponding to the water repellent portion of the non-skin facing surface of the bodily fluid backflow prevention layer in the skin facing surface of the bodily fluid backflow prevention layer,
An absorptive article in which the hydrophilic part is located in a portion corresponding to the water repellent part of the skin facing surface of the bodily fluid backflow preventing layer in the non-skin facing surface of the bodily fluid backflow preventing layer.   In the planar projection from the skin facing surface or the non-skin facing surface, the body fluid backflow prevention layer has the hydrophilic portion interposed between the water repellent portion on one surface and the water repellent portion on the other surface. The absorbent article according to claim 1, wherein the absorbent article has a water-repellent reinforced region.   In the planar projection from the skin facing surface or the non-skin facing surface of the body fluid backflow prevention layer, the water repellent portion on one surface and the water repellent portion on the other surface are alternately arranged in the vertical direction or the horizontal direction. The absorbent article according to claim 1 or 2.   A surface sheet that can come into contact with the skin of the wearer when worn is disposed on the skin facing surface side of the absorbent core, and the body fluid backflow prevention layer is disposed between the surface sheet and the absorbent core. The absorptive article according to any one of claims 1 to 3.   The total area of the water repellent part on the skin facing surface of the bodily fluid backflow prevention layer is smaller than the total area of the water repellent part on the non-skin facing surface of the bodily fluid backflow preventing layer. The absorbent article according to one item.   The absorptive article according to any one of claims 1 to 5 in which said hydrophilic part is arranged on a longitudinal center line which bisects the skin opposing surface in the skin opposing surface of said bodily fluid backflow prevention layer.   The absorbent article according to any one of claims 1 to 6, wherein each of the hydrophilic portions of the skin-facing surface and the non-skin-facing surface of the body fluid backflow prevention layer has a longitudinal length longer than a lateral length. .   The absorbent article according to any one of claims 1 to 7, wherein the water-repellent part is arranged on any one imaginary straight line that crosses the skin-facing surface of the body fluid backflow prevention layer in the lateral direction. .   The absorbent article according to any one of claims 1 to 8, wherein the hydrophilic portion of the skin-facing surface of the bodily fluid backflow prevention layer is open to an edge of the bodily fluid backflow prevention layer.

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