JP4972500B2 - Absorbent articles - Google Patents

Description

  The present invention relates to an absorbent article used for absorbing and holding liquid discharged from the body, such as a sanitary napkin, a panty liner (a falling article sheet), an incontinence pad, and a top sheet for the absorbent article.

As a surface sheet such as a sanitary napkin, a sheet having irregularities on the surface is known.
For example, a sheet made of nonwoven fabric having a three-dimensional opening protruding on one side is known (see Patent Documents 1 and 2). In the sheet described in Patent Document 1, an annular solidified zone in which the fiber material is solidified by heat is formed around the hole. The non-woven web annular customer area surface sheet pierces the nonwoven fabric with a pointed protrusion and forms a three-dimensional opening by heating a portion located around the protrusion.

  In addition, a conduit recess and a skin contact area continuous to the periphery of the conduit recess are formed in the nonwoven fabric fused with the thermoplastic fiber, and a plurality of liquid introduction tears are provided at the bottom and side portions of the conduit recess. The thing is proposed (refer patent document 3).

JP-A-62-125061 JP-A-8-246321 JP-A-4-58951

Among the conventional surface sheets described above, those having a three-dimensional aperture, such as the sheets of Patent Documents 1 and 2, are used for sanitary napkins and the like, such as menstrual blood absorbed by the absorbent body There is a drawback that the color is easily visible from the outside through the aperture. Further, since the lower end is open, the three-dimensional shape tends to be crushed, or the recoverability from the crushed state is inferior, and the cushioning property tends to be insufficient. Furthermore, in the sheet | seat of patent document 1, since the movement of the liquid by the solidification area around a hole osmose | permeating in a sheet | seat is prevented, it is inferior to the liquid transferability from a sheet | seat surface to an absorber.
On the other hand, the surface sheet of Patent Document 3 uses a low degree of freedom of fiber (easy to move) in the nonwoven fabric to form a liquid tear when the conduit recess is formed, so that the three-dimensional shape of the conduit recess is easily crushed. Also, cushioning is inferior.

Accordingly, an object of the present invention is to provide an absorbent article having a recess having a bottom, good liquid transferability to the absorbent body and cushioning properties, and that does not cause wrinkles on the topsheet even when curved when worn. It is to provide.
Another object of the present invention is to have a recess having a bottom, good liquid transfer to the absorber and good cushioning properties, and a high rigidity portion and recesses in the fiber orientation direction of the recesses to provide a surface sheet. An object of the present invention is to provide a surface sheet for absorbent articles that is less prone to wrinkles.

  The present invention comprises a liquid-permeable top sheet, a back sheet, and an absorbent body interposed between the two sheets, and is a substantially vertically long absorbent article. The top sheet is composed of a nonwoven fabric, The surface side has a surface part that comes into contact with the skin, and a plurality of liquid introduction recesses having a peripheral wall part and a bottom part and projecting toward the absorber side. A high-rigidity portion is provided at or near the boundary between the surface portion and the peripheral wall portion, and the high-rigidity portion provides the object by providing an absorbent article having higher rigidity than each of the surface portion and the peripheral wall portion. Achieved.

  Further, the present invention is a surface sheet for absorbent articles used for the skin contact surface of the absorbent article, comprising a nonwoven fabric, the nonwoven fabric comprising a surface portion whose surface side contacts the skin, a peripheral wall portion, A plurality of liquid introduction recesses having a bottom and projecting toward the absorber side, and in a cross-section along the fiber orientation direction of the nonwoven fabric, a high-rigidity portion is provided at or near the boundary portion between the surface portion and the peripheral wall portion. The high-rigidity part achieves the object by providing a surface sheet for absorbent articles that has higher rigidity than the surface part and the peripheral wall part.

The absorbent article of the present invention has a recess having a bottom, has good liquid transfer to the absorbent body and cushioning properties, and is less likely to wrinkle on the topsheet even when it is curved when worn.
The top sheet for an absorbent article of the present invention has a recess having a bottom, has good liquid transferability and cushioning properties to the absorber, and further has a highly rigid portion before and after the recess in the fiber orientation direction, and It is hard to produce wrinkles on the surface sheet due to the recess.

The present invention will be described below based on preferred embodiments with reference to the drawings.
As shown in FIG. 1, a sanitary napkin 10 (hereinafter also simply referred to as a sanitary napkin 10) according to an embodiment of the present invention includes a liquid-permeable top sheet 1, a back sheet 11, and both of these sheets 1, 11. It has an absorber 12 interposed therebetween, and is formed substantially vertically long. The top sheet 1 and the back sheet 1 are joined to each other outside the periphery of the absorber 12.
The sanitary napkin 10 includes a pair of wings 13 and 13 on both the left and right sides of the excretion part facing part A that is disposed to face the wearer's liquid excretion part when worn. As shown in FIG. 1, the sanitary napkin 10 is in a curved state so that the longitudinal cross-sectional shape forms a concave shape when worn. In the topsheet 1, “the bending direction of the absorbent article when worn” is the longitudinal direction X of the napkin 10, and the direction orthogonal to the bending direction is the width direction Y of the napkin 10.

The surface sheet 1 used for the sanitary napkin 10 is an embodiment of the surface sheet for absorbent articles of the present invention, and is made of a nonwoven fabric as shown in FIGS. 31 has a surface portion 3 that comes into contact with the skin, and a plurality of liquid introduction recesses 4, 4,... Having a peripheral wall portion 43 and a bottom portion 44 and projecting toward the absorber 12 side (lower side in FIG. 3). It becomes.
As shown in FIG. 3, the liquid guide recess 4 has a concave shape on the front surface 41 side and a convex shape on the back surface 42 side.
As the nonwoven fabric 2, various nonwoven fabrics conventionally used for the surface sheet of the absorbent article can be used without particular limitation. For example, an air-through nonwoven fabric, an airlaid nonwoven fabric, a spunlace nonwoven fabric, a needle punched nonwoven fabric, or the like can be used. it can. Among these, an air through nonwoven fabric is preferable. The air-through nonwoven fabric is obtained by forming a fiber web formed by the card method or air-laying method into a nonwoven fabric by hot air treatment using the air-through method.
The surface 31 of the surface portion 3 and the surface 41 of the liquid guide recess 4 are one side of the topsheet 1 that is directed to the wearer's skin when incorporated in the absorbent article 1, and the back surface of the surface portion 3. 32 and the back surface 42 of the liquid guide recess 4 are the other surface of the topsheet 1 that is directed to the side opposite to the wearer's skin (absorber side) in a state of being incorporated in the absorbent article 1. .

  The constituent fiber of the nonwoven fabric 2 is preferably a heat-fusible fiber, particularly a fiber made of a thermoplastic polymer material, from the viewpoint of forming a liquid introduction recess having excellent three-dimensional stability. Examples of the thermoplastic polymer material include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, and polyamides. Moreover, a core-sheath type or side-by-side type composite fiber made of a combination of these thermoplastic polymer materials is also preferably used. These fibers can be used alone or in combination of two or more. The nonwoven fabric 2 may contain fibers having no heat-fusibility, such as pulp fibers, in addition to the heat-fusible fibers. The proportion (weight basis) of the heat-fusible fiber in all the constituent fibers of the nonwoven fabric is preferably 50 to 100%, more preferably 80 to 100%, and particularly preferably 100%. Moreover, it is preferable that the heat-fusible fiber in the nonwoven fabric 2 is made hydrophilic.

In the state in which the surface sheet 1 is incorporated in an absorbent article, the surface 31 side of the surface portion 3 contacts the skin of the wearer. The surface portion 3 is a portion where the surface 31 side contacts the wearer's skin in this way.
The surface portion 3 in the surface sheet 1 is a portion that maintains a substantially planar shape even after the nonwoven fabric used as the raw material sheet has been subjected to uneven processing to form the liquid introduction recess 4. Further, the surface portion 3 is continuously formed around each liquid introduction recess 4.
Since the surface sheet 1 is formed so that a large number of liquid introduction recesses 4 protrude from the surface portion 3 toward the absorber, the surface sheet 1 has a large number of independent protrusions protruding toward the skin side. As compared with the above, the liquid flowing along the skin can be taken into the surface sheet 1 more quickly. Therefore, inconvenience due to the liquid flowing along the skin, for example, liquid leakage from the absorbent article can be effectively prevented.

As shown in FIGS. 2 and 3 (a), the topsheet 1 has a surface portion 3 that comes into contact with the skin and a peripheral wall portion 41 of the liquid guide recess 4 in the longitudinal sectional view of the napkin (see FIG. 3 (a)). And a high-rigidity portion 45 at the boundary.
More specifically, the high-rigidity portion 45 is formed at the peripheral edge of the opening of the liquid introduction recess 4. In addition, two high-rigidity portions 45 are formed for one liquid guide recess 4, and they are formed before and after the liquid guide recess 4 in the longitudinal direction X of the sanitary napkin 1.

Each high-rigidity portion 45 has higher rigidity than the surface portion 3 that comes into contact with the skin in the longitudinal section of the napkin (see FIG. 3A). Here, the rigidity of the surface part 3 is the rigidity of the central part 3A of the surface part 3 or the adjacent part on the side of the central part 3A among the two adjacent parts adjacent to the high-rigidity part 45 in the longitudinal direction of the napkin. Of rigidity. As shown in FIG. 3, the central portion 3 </ b> A of the surface portion 3 is a portion located at the approximate center between the adjacent liquid introduction recesses 4.
Further, each high-rigidity portion 45 is higher in rigidity than the peripheral wall portion 43 of the liquid introduction recess 4 in the longitudinal section of the napkin (see FIG. 3A). The rigidity of the peripheral wall part 43 here is the rigidity of the adjacent part on the bottom 44 side of both parts adjacent to the high-rigidity part 45 in the longitudinal direction of the napkin.
The two high-rigidity portions 45, 45 are formed so as to be spaced apart from each other in the circumferential direction of the opening portion of the liquid introduction recessed portion 4, and each high-rigidity portion 45 includes the surface portion 3 that contacts the skin and the liquid introduction recessed portion. Each of the peripheral wall portions 43 has higher rigidity. The individual high rigidity portions 45 are substantially linear in the plan view of the topsheet 1.
The rigidity referred to in the present invention is a rigidity in the sense of density due to the fibers being fixed in a more aggregated state, and the rigidity of the two parts to be compared is taken, for example, by photographing a cross section. This can be judged by the difference in thickness between the two parts measured from the micrograph, that is, the difference in density. In addition, since the shape in which the nonwoven fabric used for a surface sheet does not have a fiber shape can also occur in a highly rigid part, it expresses not a fiber density but a density.
In addition, the highly rigid part 45 in the surface sheet 1 of this embodiment has higher rigidity than each part 46 and 46 (refer FIG. 2) adjacent to this highly rigid part 45 in the circumferential direction of the liquid introduction recessed part 4. FIG.

The top sheet 1 used in this embodiment has the above-described high-rigidity portions 45, 45 formed in the vicinity of the opening of the liquid introduction recess 4, so that the napkin 10 can be used when the sanitary napkin 10 is worn. As shown in FIG. 4, even if the topsheet 1 is similarly bent, wrinkles are unlikely to occur in the topsheet 1.
That is, in the absence of such a high-rigidity portion 45, the deformation of the surface sheet is larger than the amount of deformation of the absorber due to bending, and distortion occurs and irregular wrinkles occur. Although this may cause inconveniences such as liquid flow and deterioration of touch, if the high-rigidity portion 45 having the above-described configuration is provided on the topsheet 1 as in the present embodiment, the high-rigidity portion 45 is Since it becomes a flexible shaft and is deformed to prevent deformation of the central portion 3A of the surface portion 3, it is possible to reduce the deterioration of the liquid flow and the touch caused by irregular wrinkles. If the high-rigidity portion 45 is formed in an annular shape so as to cover the entire circumferential direction of the liquid guide recess 4, the liquid stays in the high-rigidity portion where the touch is reduced and the density is high, and the liquid is transferred to the absorber. It is preferable that the high-rigidity part is not continuous at least partially from the point of preventing the above.

  The high-rigidity portion 45 is a range from the height position of the front surface 31 to the height position of the back surface 32 in the central portion 3A of the front surface portion 3 in the thickness direction Z of the front surface sheet 1 (thickness indicated by L3 in FIG. 3). (Within range).

  Moreover, the nonwoven fabric 2 in the high rigidity part 45 can suppress generation | occurrence | production of a wrinkle that the fiber which comprises the nonwoven fabric as a whole and the nonwoven fabric is deformed, and can maintain favorable touch, This is preferable from the viewpoint that the high-rigidity portion 45 is stably present. This is because if the whole is a film, the thickness of the sheet becomes thin and it is easy to break. If the film-like portion is scattered in the high-rigidity portion 45, the high-rigidity portion 45 can be further stabilized.

Moreover, in the sanitary napkin 10 of this embodiment, as shown in FIG. 4, the liquid introduction recessed parts 4 are arrange | positioned at the surface sheet 1 in zigzag form. A plurality of high-rigidity part rows L ₄₅ formed by intermittently arranging a plurality of high-rigidity parts 45, 45... In the direction of curvature of the sanitary napkin 1 (absorbent article) when worn. It is formed to extend in the napkin width direction Y, which is a direction perpendicular to it. Specifically, the high-rigidity portions 45 of the two liquid introduction recessed portion rows adjacent to each other in the longitudinal direction X of the napkin 1 are arranged in substantially one row in the width direction Y of the napkin 1 so that the high-rigidity portion row L _45. Is forming. A large number of such high-rigidity part rows L ₄₅ are arranged at intervals in the longitudinal direction X of the napkin 1.
By arranging the high-rigidity portions 45 in this way, it is possible to more effectively prevent wrinkles perpendicular to the bending direction that occur because the deformation amount of the topsheet is larger than the deformation amount of the absorber. it can.

The interval between the high-rigidity part rows L ₄₅ in the longitudinal direction X of the napkin 1 is preferably 1.5 mm to 6.0 mm, particularly preferably 2.5 mm to 4.0 mm.
Further, the distance from the center to the center in the width direction Y of the napkin 1 of the high rigidity portion included in the high rigidity portion row is preferably 1.5 mm to 5.5 mm, particularly preferably 1.5 mm to 4.0 mm.
When the high-rigidity portion row is within the above range, the portion that absorbs deformation and the portion that suppresses wrinkles with respect to the deformation of the topsheet are appropriately disposed, and the above-described effects can be more easily exhibited.

In the topsheet 1 in the present embodiment, the fiber orientation direction of the nonwoven fabric 2 matches the longitudinal direction X of the sanitary napkin 1.
The plurality of high-rigidity part rows L ₄₅ described above are each formed to extend in a direction (Y direction) orthogonal to the fiber orientation direction of the nonwoven fabric 2. Accordingly, the distortion of the recesses due to the external force mainly due to the conveyance of the nonwoven fabric is suppressed by the high rigidity portion around the width direction of each recess, and the distortion is not fixed by the high rigidity portion adjacent to each recess. The sheet is less likely to wrinkle (due to stretching and fixing it).

Further, the high-rigidity portions 45 and 45 formed in the vicinity of the opening of the liquid introduction recess 4 are formed before and after each of the liquid introduction recesses 4 in the fiber orientation direction (X direction) of the nonwoven fabric 2.
Since the high-rigidity portion 45 is arranged before and after the liquid introduction recess 4 in relation to the fiber orientation direction, the high-rigidity portion 45 can be stably molded and left and right orthogonal to the fiber orientation direction. Can be kept flexible.

The liquid introduction recessed part 4 of the surface sheet 1 used by this embodiment has the surrounding wall part 43 and the bottom face part (bottom part) 44, as shown in FIG. Further, the bottom surface portion 44 is located closer to the absorber than the back surface 32 of the front surface portion 3. That is, the bottom surface portion 44 is located on the absorber side (lower side in FIG. 3) from the position of the back surface 32 of the top surface portion 3 in the thickness direction Z (see FIG. 3) of the topsheet 1.
The peripheral wall portion 43 is inclined with respect to a vertical line extending in the thickness direction of the topsheet 1, and the cross section of the portion surrounded by the peripheral wall portion 43 of the topsheet 1 (a plane orthogonal to the thickness direction of the topsheet 1). The area of the cross-section) gradually decreases from the surface portion 3 side toward the bottom surface portion 44. More specifically, the inner surface has a substantially inverted truncated cone shape.
The bottom surface portion 44 is substantially circular in plan view, and the peripheral wall portion 43 is continuous around the bottom surface portion 44. Although the bottom surface portion 44 in the present embodiment is formed in a substantially flat shape, the bottom surface portion 44 can be formed in a convex curved surface shape having a convex arcuate shape with a cross section facing downward.

The liquid introduction recessed part 4 in this embodiment is the site | part adjacent to the bottom face part 44 in the surrounding wall part 43 in the cross section (The cross section orthogonal to the fiber orientation direction of a nonwoven fabric) of the width direction Y of the napkin 1 (FIG.3 (b)). The thickness Ta of the portion indicated by symbol A (hereinafter also referred to as the bottom portion adjacent portion A) is smaller than the thickness T1 of the surface portion 3. Therefore, the fiber density of the nonwoven fabric in the bottom portion adjacent portion A is higher than the fiber density of the nonwoven fabric in the surface portion 3. Thus, by the difference (gradient) in the fiber density between the surface portion 3 and the bottom surface adjacent portion A, the liquid taken into the surface sheet 1 in the surface portion 3 and / or the peripheral wall portion 43, It is easy to shift to the bottom portion adjacent portion A. The bottom surface adjacent portion A is a portion where, when the topsheet 1 is disposed on the absorbent body, the liquid can be naturally transferred to the absorbent body in contact with or close to the absorbent body. Thus, the liquid guide recessed part 4 has a function which guide | induces the liquid taken in in the surface part 3 and / or the surrounding wall part 43 to an absorber.
Thus, in at least one of the cross sections in the longitudinal direction X and the width direction Y of the napkin, when the thickness Ta of the bottom surface adjacent portion A is smaller than the thickness T1 of the surface portion 3, the liquid transfer property to the absorber is improved. be able to.

In addition, as described above, the topsheet 1 of the present embodiment has the bottom portion 44 of the liquid introduction recess 4 and the bottom end of the liquid introduction recess 4 is not open, so that the configuration of the liquid introduction recess 4 is stable. Even if a compressive force is applied to the surface sheet 1 in the thickness direction while wearing the absorbent article, the liquid guide recess 4 is not easily crushed, or even if it is crushed, it has excellent restoring force when released from the compressive force. Yes. Therefore, it has a good cushioning property and a good texture.
Furthermore, since the liquid introduction recessed part 4 has the bottom face part 44 and the liquid which moved to the absorber is concealed by the bottom face part 44, for example, when used as a top sheet of a sanitary napkin, the napkin after use It is possible to prevent the menstrual blood from becoming noticeable.

  From the viewpoint of improving the transferability of the liquid to the absorber, the thickness Ta of the bottom portion adjacent portion A is preferably 3 to 80%, particularly 5 to 50% of the thickness T1 of the surface portion 3. The thickness T1 is preferably 0.4 to 2.5 mm, and the thickness Ta is preferably 0.1 to 0.4 mm. In addition, the thickness T1 of the surface part 3 is measured in the center part 3A between the adjacent liquid introduction recessed parts 4, as shown in FIG. Further, the thickness Ta of the bottom portion adjacent portion A is the thickness at the portion A of the nonwoven fabric constituting the liquid introduction recess 4 as shown in FIG.

Moreover, the peripheral wall part 43 of the liquid introduction recessed part 4 in this embodiment is the surface part 3 side in the cross section (it is the same as the cross section orthogonal to the fiber orientation direction of a nonwoven fabric) of the width direction Y of the napkin 1, as shown in FIG. Accordingly, the thickness of the nonwoven fabric constituting the peripheral wall portion 43 gradually increases from the surface portion 3 side toward the bottom surface portion 44 side. When the fiber density is changed in this way in at least one of the cross-sections in the longitudinal direction X and the width direction Y of the napkin, the liquid transferability from the surface portion 3 and / or the peripheral wall portion 43 to the bottom surface adjacent portion A, elongation In this case, the transferability of the liquid to the absorber is further improved.
From the viewpoint of improving the transferability of the liquid to the absorber, the thickness Ta of the bottom portion adjacent portion A of the peripheral wall portion 43 is a portion adjacent to the surface portion 3 in the peripheral wall portion 43 (the portion indicated by symbol B in FIG. 3). In the following description, the thickness Tb is preferably 5 to 80%, more preferably 5 to 50%. In addition, as shown in FIG. 3, the thickness Tb of the surface part adjacent part B is the thickness in this part B of the nonwoven fabric which comprises the liquid introduction recessed part 4. As shown in FIG.

Furthermore, in the liquid introduction recess 4 in this embodiment, the thickness Tb of the surface portion adjacent portion B is smaller than the thickness T1 of the surface portion 3. Thereby, the transferability of the liquid from the surface portion 3 to the peripheral wall portion 43 is further improved, and the transferability of the liquid to the absorber is further improved. From the viewpoint of improving the transferability of the liquid from the surface portion 3 to the peripheral wall portion 43, the thickness Tb of the surface portion adjacent portion B is 20 to 90%, particularly 40 to 90% of the thickness T1 of the surface portion 3. Is preferred.
The thicknesses T1, Ta, and Tb are thicknesses under no load, and are obtained from, for example, a micrograph obtained by photographing a cross section. The same applies to the thickness T of the surface sheet described later.

  It is preferable that the nonwoven fabric 3 in the bottom face portion 44 has a bonding point between fibers and maintains liquid permeability. The presence of the bonding point between the fibers can improve the liquid permeability of the top sheet while improving the stability of the three-dimensional shape of the liquid guide recess 4, and further prevents the deterioration of the touch when it is made into a film. can do. The bonding point between the fibers does not include a filmed portion or one formed by pressing a nonwoven fabric by embossing. The bonding point between the fibers is preferably one in which the fibers are thermally fused at their intersections by hot air treatment using an air-through method.

The liquid introduction recessed part 4 in the surface sheet 1 of this embodiment has the surface part 3 in both directions of the fiber orientation direction (X direction in the figure) of the nonwoven fabric 2 and the direction (Y direction in the figure) perpendicular thereto as shown in FIG. They are arranged so that they do not exist in a continuous straight line.
Since the surface portion 3 does not exist in a continuous straight line in the X direction or the Y direction, a larger number of the liquid introduction recesses 4 can be arranged, and the area of the surface portion 3 that is in contact with the skin can be reduced. Thereby, the stickiness with respect to the skin can be suppressed, and further, the liquid that oozes between the skin and the surface portion 3 can be made harder to bleed than the continuous linear one.
On the other hand, FIG. 5 is a diagram showing an embodiment in which the surface portion 3 is present in a continuous linear shape in the distribution orientation direction (X direction in the drawing) of the nonwoven fabric 2 and the direction orthogonal to the direction (Y direction in the drawing). is there. In FIG. 5, the surface portion 3 extends in a continuous straight line along the straight line LY, and the surface portion 3 extends in a continuous straight line along the straight line LX.

The topsheet 1 preferably has the following configuration from the viewpoint of stability of the form of the liquid introduction recess 4 and improvement of cushioning properties.
The basis weight is preferably 15 to 50 g / m ² , particularly preferably 20 to 40 g / m ² , and the fineness of the constituent fibers is preferably 1.2 to 6.7 dtex.
The diameter W1 of the opening on the surface portion 3 side (see FIG. 3, the diameter of a circle having the same area when the opening shape is non-circular) is preferably 2.0 to 7.0 mm, and the diameter W2 of the bottom surface portion 44. (See FIG. 3, in the case of a non-circular shape, the diameter of a circle having the same area) is preferably 0.5 to 2.5 mm.
The thickness T (see FIG. 3) of the surface sheet 1 is preferably 0.5 to 3.0 mm, and the ratio of the thickness T1 of the surface portion to the thickness T is 20 to 90%, particularly 40 to 90%. It is preferable.
Further, the number of the liquid guide recesses 4 is preferably about 10 to 100, more preferably about 20 to 70, per 9 cm ^{2 of the} topsheet.

The manufacturing method of the surface sheet 1 mentioned above can be manufactured as follows, for example.
In the preferable manufacturing method of the surface sheet 1, as shown in FIG. 6, a large number of liquid guide recesses 4, 4,... Are formed on a raw material sheet 20 made of a nonwoven fabric by using a pair of rolls 5, 6. Get one. The nonwoven fabric used as the raw material sheet 20 is preferably an air-through nonwoven fabric. The air-through nonwoven fabric has an appropriate stretchability (degree of freedom of deformation of the fiber structure), and since the fibers are not easily separated even if they are stretched by having bonding points between the fibers, the liquid introduction recessed portion 4 having a stable form. Suitable for forming. Moreover, a nonwoven fabric makes the fiber orientation direction correspond with the flow direction (MD direction) of the raw material sheet 20.

As shown in FIG. 6, in this manufacturing method, the formation of the liquid introduction recess 4 includes a first roll 5 having a large number of convex portions 51 on the peripheral surface and a large number of concave portions corresponding to the convex portions 51 on the peripheral surface. A stretching and heating device provided with a second roll 6 having 6 is used.
The first roll 5 and the second roll 6 in this apparatus are driven to rotate in the direction indicated by the arrows in FIG. 6 in synchronism with each other. The parts 5 are configured to be inserted into the corresponding recesses 6 (free insertion) sequentially. The convex portion 51 inserted into the concave portion 6 does not come into contact with the inner surface of the concave portion 6.
In the example shown in FIG. 6, the convex portion 51 has a columnar shape, and the concave portion 6 has a bottomed cylindrical shape having an inner diameter larger than the diameter of the convex portion 51. Further, the recess 6 has a recess 6 in any cross section (cross section shown in FIG. 7) orthogonal to the axial length direction of the roll 6 and the cross section along the axial length direction of the roll 6 (cross section shown in FIG. 8). The inner peripheral surface 62 and a portion 63 (smooth roll peripheral surface) other than the concave portion of the roll 6 are coupled to each other at a substantially right angle at the boundary portion (opening peripheral edge portion of the concave portion).

As shown in FIG. 6, when a raw material sheet 20 made of a nonwoven fabric is introduced between the rotating first and second rolls 5, 6, the raw material sheet 20 is recessed by a convex portion 51 as shown in FIG. 7. In the state where the portion other than the concave portion 61 of the second roll 6 is in contact with the back surface, the portion located on the concave portion 61 is pressed by the convex portion 51 and the portion of the second roll 6 is pressed against the rear surface. It is pushed into the recess 61.
At the time of this pushing, there is a portion 23 in the raw material sheet 20 that does not come into contact with either the convex portion 51 or the concave portion 61 around the portion 24 that comes into contact with the tip portion of the convex portion 51 and is directly pressed. The portion 23 extends more than the other portions.
Then, heat is applied to the portion 23 in the extended state from the inner surface of the recess 61, and the extended state is fixed (heat set) by the heat, and the liquid introduction recess 4 having a stable structure is formed.
Moreover, the nonwoven fabric which comprises the raw material sheet 20 is easy to extend in the flow direction (MD) of the raw material sheet 20 at the time of pushing into the recessed part 61 by the convex part 51, and is relative to the direction (CD) orthogonal to this flow direction. It is difficult to stretch. Therefore, in the flow direction (MD) of the raw material sheet 20, the portions located at the front and rear ends of the recess 61 are strongly compressed and compressed by the opening edge of the recess 61 formed substantially at right angles, and the state is thermally fixed. A highly rigid portion 45 is formed.
Thus, the surface sheet 1 in which many high rigidity parts 45 were formed is obtained. In the obtained topsheet 1, the bottom surface portion 44 is mainly composed of a portion 24 that is directly pressed against the tip portion of the convex portion 51, and the peripheral wall portion 43 is mainly composed of the portion 23.

A material for forming the sanitary napkin 10 will be described.
As the absorber 12 and the back sheet 11, materials that are usually used in the technical field can be used without particular limitation. For example, as the absorbent body, a fiber assembly made of a fiber material such as pulp fiber or a fiber assembly in which an absorbent polymer is held can be coated with a covering sheet such as tissue paper or nonwoven fabric. As the back sheet, a liquid-permeable or water-repellent sheet such as a thermoplastic resin film or a laminate of the film and a nonwoven fabric can be used. The back sheet may have water vapor permeability.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to embodiment mentioned above.

  For example, the planar view shape of the liquid introduction recess 4 may be an ellipse instead of a perfect circle as shown in FIG. 4, and may be a polygonal shape such as a rhombus, a square, a rectangle, a heart shape, or a star shape. Etc. For example, when a polygon is used, it is preferable to round the corners. Further, the shape of the high-rigidity portion 45 may be a crescent shape, an elliptical shape, an oval shape, a fan shape, or the like extending along the circumferential direction of the liquid introduction recessed portion 4.

In addition, as shown in FIG. 1, the absorbent article is curved so that the cross-sectional shape in the width direction forms a concave shape, instead of the one in which the cross-sectional shape in the longitudinal direction forms a concave shape when worn. It may be a state that has been made. Moreover, you may have a highly curved part in a different aspect in the part which has a part which curves in a longitudinal direction, and a part which curves in the width direction, and distributes to each. In the above-described surface sheet 1, two high-rigidity portions are provided in one liquid introduction recess 4, but the liquid introduction recess 4 is provided only in one of the front and rear of the liquid introduction recess in the fiber orientation direction. Also good. Moreover, the liquid introduction recessed part 4 which has the highly rigid part 45 may be formed only in a part of surface sheet 1, for example, the part distribute | arranged to the excretion part opposing part A. FIG.
Moreover, a surface sheet may be used by aligning the fiber orientation direction of the nonwoven fabric with the width direction of the absorbent article.

  Moreover, when arrange | positioning the liquid introduction recessed part 4 so that the surface part 3 may not exist in a continuous linear form in the fiber orientation direction of the nonwoven fabric 2, or the direction orthogonal to it, this liquid introduction recessed part 4 is surfaced in any one direction. You may arrange | position so that the part 3 may exist in a continuous linear form. Further, instead of disposing the liquid guiding recess 4 in this way on the entire surface sheet, the liquid guiding recess 4 may be disposed only in the vicinity of the portion disposed near the liquid excretion portion and the vicinity thereof. good.

  In addition, the high-rigidity portion 45 is not limited to the one formed at the boundary portion between the surface portion 3 and the peripheral wall portion 41 of the liquid introduction recess 43 in a strict sense, but may be formed near the boundary portion. good. Moreover, you may have the length ranging from the surface part 3 to the surrounding wall part 41. FIG.

The absorbent article of the present invention is used for absorbing and holding liquid discharged from the body. Examples of such absorbent articles include panty liners, incontinence pads, disposable diapers, and breast milk pads in addition to sanitary napkins. The sanitary napkin or the like may not include a pair of wing portions on the left and right sides of the excretory portion facing portion.
The absorbent article typically includes a top sheet, a back sheet, and a liquid-retaining absorbent body disposed between both sheets. The absorbent article may further include various members according to specific uses of the absorbent article. Such members are known to those skilled in the art. For example, when applying an absorbent article to a disposable diaper or a sanitary napkin, a pair or two or more pairs of three-dimensional guards can be disposed on the left and right sides of the topsheet.

It is a partial fracture perspective view showing sanitary napkin which is one embodiment of an absorptive article of the present invention. It is a perspective view which expands and shows a part of surface sheet in the sanitary napkin of FIG. 3A is an enlarged cross-sectional view showing a part of the cross section taken along line II in FIG. 2, and FIG. 3B is an enlarged view of a part of the cross section taken along line II-II in FIG. FIG. It is the expansion | deployment top view which looked at the surface sheet shown in FIG. 2 from the surface side. It is the top view (equivalent figure of FIG. 4) which looked at the surface sheet of other embodiment of this invention from the surface side. It is a figure which shows the principal part of the extending | stretching and heating apparatus which can be preferably used for manufacture of the surface sheet of FIG. It is sectional drawing which shows the cross section (III-III line cross section of FIG. 6) orthogonal to the axial length direction of the 1st and 2nd roll in the apparatus of FIG. It is sectional drawing which shows the cross section (IV-IV line cross section of FIG. 6) in alignment with the axial length direction of the 1st and 2nd roll in the apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Top sheet 2 Nonwoven fabric 3 Surface part 4 Liquid introduction recessed part 43 Perimeter wall part 44 Bottom face part 45 High rigidity part 5 1st roll 51 Convex part 6 2nd roll 61 Concave part

Claims (5)

A liquid-permeable top sheet, a back sheet and an absorbent body interposed between both sheets, and a substantially vertically long absorbent article,
The surface sheet is made of a nonwoven fabric, and the nonwoven fabric has a surface portion with which the surface side comes into contact with the skin, and a plurality of liquid introduction recesses having a peripheral wall portion and a bottom portion and projecting toward the absorber side,
The top sheet has a high-rigidity part at or near the boundary between the surface part and the peripheral wall part in the longitudinal cross-sectional view of the absorbent article, and the high-rigidity part includes the surface part and the peripheral wall part, respectively. Absorbent article with higher rigidity.   The absorbent article according to claim 1, wherein the fiber density of the high-rigidity part is higher than the fiber density of the surface part and the peripheral wall part.   In the plan view of the absorbent article, the liquid introduction recesses are arranged in a staggered manner, and a plurality of high rigidity portion rows in which the plurality of high rigidity portions are intermittently arranged in approximately one row are respectively absorbent. The absorbent article according to claim 1, wherein the absorbent article is formed extending in a width direction of the article.   The absorbent article according to claim 3, wherein the high-rigidity part row is formed in a direction orthogonal to a fiber orientation direction of the nonwoven fabric. A surface sheet for absorbent articles used on the skin contact surface of the absorbent article,
The nonwoven fabric is made of a nonwoven fabric, and the nonwoven fabric has a surface portion with which the surface side comes into contact with the skin, and a large number of liquid introduction recesses having a peripheral wall portion and a bottom portion and projecting toward the absorber side,
In a cross section along the fiber orientation direction of the nonwoven fabric, the nonwoven fabric has a high rigidity portion at or near the boundary portion between the surface portion and the peripheral wall portion, and the high rigidity portion has higher rigidity than each of the surface portion and the peripheral wall portion. A surface sheet for absorbent articles.

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