CN112004509B - Absorbent article - Google Patents

Abstract

An absorbent article according to one aspect of the present invention includes a liquid-permeable front sheet, a back sheet, and an absorbent body having an absorbent core and disposed between the front sheet and the back sheet, and has a longitudinal direction corresponding to a front-back direction of a wearer and a lateral direction perpendicular to the longitudinal direction. The absorbent core comprises: a front core portion and a rear core portion located on both end portions in the longitudinal direction; and an intermediate core portion located between the front core portion and the rear core portion and having a width smaller than that of the front core portion and the rear core portion. The above-mentioned middle core includes: a high-grammage portion located at the lateral center and protruding toward the back sheet; and a low grammage portion having a lower grammage than the high grammage portion and formed at the lateral side portion of the high grammage portion.

Description

Absorbent article

Technical Field

The present invention relates to an absorbent article such as a sanitary napkin.

Background

An absorbent article of a type to be used while being disposed inside an undergarment, such as a sanitary napkin, has an absorber for absorbing a liquid material such as menstrual blood. The absorbent body has not only an absorbent core for absorbing and diffusing the liquid substance but also a core-wrapping sheet for wrapping the absorbent core. For example, patent document 1 discloses an absorbent article in which a protrusion for improving the fit to a excretory region is provided in a central region of an absorbent core that faces the excretory region of a wearer.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2014-104093

Disclosure of Invention

An absorbent article according to one aspect of the present invention includes a liquid-permeable front sheet, a back sheet, and an absorbent body having an absorbent core and disposed between the front sheet and the back sheet, and has a longitudinal direction corresponding to a front-back direction of a wearer and a lateral direction perpendicular to the longitudinal direction.

The absorbent core comprises: a front core portion and a rear core portion located on both end portions in the longitudinal direction; and an intermediate core portion located between the front core portion and the rear core portion and having a width smaller than that of the front core portion and the rear core portion.

The above-mentioned middle core includes: a high-grammage portion located at the lateral center and protruding toward the back sheet; and a low grammage portion having a lower grammage than the high grammage portion and formed at the lateral side portion of the high grammage portion.

Drawings

Fig. 1 is a perspective view showing an absorbent article according to an embodiment of the present invention.

Fig. 2 is a plan view showing the absorbent article.

Fig. 3 is a sectional view taken along line III-III of fig. 2.

Fig. 4 is a view showing the absorbent core of the absorbent article, and is a rear view seen from the lower surface side.

Fig. 5 is a sectional view schematically showing the structure of the intermediate core portion of the absorbent core, and fig. 5A shows a non-worn state and fig. 5B shows a worn state.

Fig. 6 is a back view of the absorbent body of the absorbent article.

Fig. 7 is a schematic view illustrating a relationship between hip seams of the buttocks of the wearer and a deformed state of the rear core portion of the absorbent core when the absorbent article is worn.

Fig. 8 is a plan view of the absorbent article showing a positional relationship between the lateral groove portion of the rear core portion and the three-dimensional cuff.

Detailed Description

Various external forces are applied to the absorbent article from the wearer as the absorbent article is worn. For example, a lateral external force is applied to the middle portion of the absorbent article from the left and right legs of the wearer. Further, a thickness direction pressure from the wearer is applied to the topsheet side of the absorbent article. Therefore, an absorbent article capable of maintaining high fit even when subjected to these external forces is required.

The present invention relates to an absorbent article having high fit.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[ integral Structure of sanitary napkin ]

The absorbent article 1 shown in fig. 1 and 2 includes a main body M, a pair of wing portions W, a pair of three-dimensional cuffs G, a pair of rear flap portions F, and compression groove portions E. The absorbent article 1 is configured as a sanitary napkin, hereinafter referred to as a sanitary napkin 1.

The sanitary napkin 1 has a longitudinal direction X corresponding to the front-rear direction of the wearer, and a lateral direction Y corresponding to the left-right direction of the wearer and orthogonal to the longitudinal direction X. Further, the sanitary napkin 1 has a thickness direction Z orthogonal to both the longitudinal direction X and the transverse direction Y. In the present specification, the side closer to the skin of the wearer when worn is sometimes referred to as the upper side and the side closer to the clothing worn is sometimes referred to as the lower side with respect to the thickness direction Z.

The sanitary napkin 1 may be used at bedtime, and may have a length of 30cm or more in the longitudinal direction X, for example.

The main body M extends in the longitudinal direction X and is fixed to the inner surface of the wearer's undergarment when worn. The main body M has an absorbent body 11 described later and has a function of absorbing liquid material (hereinafter also referred to as "liquid") such as menstrual blood of a wearer.

The three-dimensional enclosure G is provided at the lateral Y periphery of the main body M and is arranged to extend in the longitudinal direction X. The three-dimensional apron G stands up in the thickness direction Z when worn, and can prevent leakage of liquid in the lateral direction Y. The term "standing in the thickness direction" means standing toward the wearer.

The compressed groove portion E is formed by being compressed downward in the thickness direction Z from the front sheet 12 described later, and is configured to surround the peripheral edge portion of the main body M, for example.

The wing W is configured to greatly protrude outward in the lateral direction Y from the main body M.

The rear flap F is configured to bulge outward in the lateral direction Y at the rear portion of the main body M.

The sanitary napkin 1 may not have at least one of the wing portions W, the three-dimensional cuffs G, the compressed groove portions E, and the rear flap portions F.

As shown in fig. 3, the sanitary napkin 1 includes an absorbent body 11, a front sheet 12, a back sheet 13 and a pair of side sheets 14. In the main body M, the sanitary napkin 1 has a structure in which a back sheet 13, an absorbent body 11, and a front sheet 12 are laminated in the thickness direction Z. These structures are appropriately joined and integrated by, for example, bonding with an adhesive or heat sealing, or embossing by the compressed groove portions E.

The absorber 11 extends in the longitudinal direction X and is disposed between the front sheet 12 and the back sheet 13. The absorbent body 11 absorbs liquid from the topsheet 12 and diffuses it therein to hold the liquid.

The absorbent body 11 has an absorbent core 16 and a core-spun sheet 17.

The absorbent core 16 may be formed of a fiber aggregate made of hydrophilic fibers such as wood pulp fibers, or may have a structure in which a water-absorbent polymer is held in the fiber aggregate.

The core sheet 17 covers the absorbent core 16, and has a function of, for example, maintaining the shape of the absorbent core 16. The core sheet 17 is formed of, for example, tissue-like thin and flexible paper, liquid-permeable nonwoven fabric, or the like.

The absorbent body 11 will be described in detail later.

The top sheet 12 is configured as a liquid-permeable sheet and is disposed above the absorbent body 11 in the thickness direction Z. The outer surface (upper surface) of the front surface sheet 12 is defined as a liquid receiving surface 12 a. In addition, a second sheet (sub-sheet) may be disposed between the topsheet 12 and the absorbent body 11, in order to improve the permeability of liquid from the topsheet 12 to the absorbent body 11, and to prevent the liquid absorbed by the absorbent body 11 from returning to the topsheet 12.

The back sheet 13 is disposed below the absorbent body 11 in the thickness direction Z. The back sheet 13 is joined to the front sheet 12 and the side sheet 14 at the peripheral edge portion thereof by, for example, an adhesive, heat sealing, or the like. The back sheet 13 may be bonded to the absorbent body 11 with an adhesive or the like.

In the back sheet 13, a body adhesion portion 18 is provided on the outer surface of the body M, and a wing adhesion portion 19 is provided on the outer surface of the wing portion W. These main body adhesion portions 18 and flap adhesion portions 19 function as a deviation preventing member for fixing the sanitary napkin 1 to a garment. These adhesive portions 18 and 19 are formed by applying an adhesive such as a hot melt adhesive to the back sheet 13. Further, although not shown, the sanitary napkin 1 may further include a rear flap adhesion portion provided in the rear flap portion F.

The pair of side sheets 14 are opposed to each other in the transverse direction Y with the topsheet 12 interposed therebetween, and are disposed on the periphery of the sanitary napkin 1 in the transverse direction Y. The side sheet 14 may be a film made of nonwoven fabric, resin, or the like. The side sheet 14 preferably has functions such as liquid impermeability, water repellency, and moisture permeability, and may have a laminated structure or a single-layer structure.

In the present embodiment, the lateral Y peripheral edge portion of the side sheet 14 is folded back outward to form the three-dimensional apron G. The side sheet 14 is joined to the front sheet 12 at the base of the three-dimensional enclosure G with an adhesive 15. The detailed structure of the space guard G will be described later.

[ Structure of absorbent core ]

As shown in fig. 3, the absorbent core 16 has an upper surface 16a located above (the front sheet 12 side) in the thickness direction Z and a lower surface 16b located below (the back sheet 13 side) in the thickness direction Z. The absorbent core 16 has an uneven structure formed on the lower surface 16b, and the grammage of each portion described below can be adjusted. The upper surface 16a is flat, for example, but can be deformed by applying pressure in the thickness direction Z from the wearer when worn. Details of this modification will be described later.

As shown in fig. 4, the absorbent core 16 has a front core portion 20, an intermediate core portion 21, and a rear core portion 22. The front core portion 20, the intermediate core portion 21, and the rear core portion 22 are aligned in the longitudinal direction X. That is, the front core portion 20 and the rear core portion 22 are located on both end portions sides in the longitudinal direction X, and the intermediate core portion 21 is located between the front core portion 20 and the rear core portion 22. The center core portion 21 is a region opposed to the excretory region of the wearer, and the front core portion 20 and the rear core portion 22 are portions opposed to the front and the rear of the excretory region of the wearer, respectively. The absorbent core 16 has a planar shape that is bilaterally symmetric in the transverse direction Y.

As shown in fig. 4, the intermediate core portion 21 has a width dimension D2 narrower than the width dimension D1 of the front core portion 20 and the width dimension D3 of the rear core portion 22. In other words, the absorbent core 16 has a planar shape that narrows in the transverse direction Y at the intermediate core portion 21.

The width dimension D2 of the intermediate core 21 refers to the smallest width dimension in the transverse direction Y. The width dimension D1 of the front core portion 20 and the width dimension D3 of the rear core portion 22 refer to the maximum width dimension in the lateral direction Y.

The absorbent core 16 has the intermediate core portion 21 having a narrow width, and thus, when the legs of the wearer are closed and the crotch width is narrowed, the external force from the lateral direction Y applied to the intermediate core portion 21 can be reduced.

The width D1 of the front core 20 and the width D3 of the rear core 22 may be the same or different, and are substantially the same in the example shown in fig. 4.

In the example shown in fig. 4, the width dimension D2 of the intermediate core portion 21 is formed to be constant in the longitudinal direction X. The width D1 of the front core portion 20 and the width D3 of the rear core portion 22 are constant in the longitudinal direction X in a region other than the front tapered region 20t and the rear tapered region 22t described later, but the present invention is not limited thereto.

In addition, the phrase "the width dimension is a constant value" in a certain region means that when the minimum width in the lateral direction Y of the region is taken as 100%, the difference in the width dimension in the region is controlled to be 20% or less. In addition, in the front core portion 20 and the rear core portion 22, when the minimum width in the lateral direction Y is taken as 100%, the difference in width dimension in each region is preferably 10% or less.

The front core portion 20 and the rear core portion 22 may have the same or different length dimensions in the longitudinal direction X, and the rear core portion 22 may be formed to be longer, for example.

[ Structure of intermediate core portion ]

The intermediate core portion 21 has a high grammage portion 23 and a low grammage portion 24, the low grammage portion 24 having a lower grammage than the high grammage portion 23. In fig. 4, the high grammage part 23 is represented by a high-density dot pattern, and the low grammage part 24 is represented by a low-density dot pattern.

The high grammage portion 23 is located at the center in the transverse direction Y and protrudes toward the back sheet 13.

The low grammage portion 24 is formed at a lateral side portion of the high grammage portion 23. In the example shown in fig. 4, the low grammage portion 24 is divided into left and right portions with the high grammage portion 23 interposed therebetween.

In the region other than the high-density compressed groove portion, the grammage of the absorbent core 16 has a positive correlation with the thickness. Therefore, the high grammage portion 23 protrudes downward in the thickness direction Z from the low grammage portion 24, and is formed thicker than the low grammage portion 24.

Further, the grammage of the absorbent core 16 has a positive correlation with the stiffness. In other words, the high grammage portion 23 is higher in rigidity than the low grammage portion 24, and is less likely to be deformed by an external force. On the other hand, the low grammage portion 24 has a structure in which the grammage is relatively low and thus easily deformed by an external force.

The shapes of the intermediate core portion 21 when it is not worn (fig. 5A) and when it is worn (fig. 5B) will be described with reference to the schematic cross-sectional view of fig. 5.

As shown in fig. 5A, the intermediate core portion 21 has a step formed between the high grammage portion 23 and the low grammage portion 24 at the lower surface 16 b.

That is, the high grammage portion 23 includes a top surface region 23b and a side surface region 23e continuously formed from the top surface region 23b on the lower surface 16 b.

The top surface region 23b is a surface facing downward in the thickness direction Z, and is formed flat as a whole.

The side surface region 23e constitutes a side surface of the high grammage portion 23 protruding downward in the thickness direction Z, and is, for example, a surface facing in the lateral direction Y.

In the example shown in fig. 5A, the side surface region 23e is formed to be perpendicular to the XY plane, and the area of the high grammage portion 23 in plan view is formed to be the same as the area of the top surface region 23 b. However, the side surface region 23e is not limited to this, and may be inclined with respect to the XY plane, for example.

On the other hand, the upper surface 16a includes a central region 23a that is flatter than the lower surface 16 b.

The phrase "the upper surface 16a or the lower surface 16b is flat" means that the regions other than the groove portions of low grammage and the compressed groove portions E described later are substantially flat, and fine irregularities caused by the protrusion of the fibers or the like of the core material are not considered. In fig. 5, the groove portions and the compressed groove portions E are not shown.

The low grammage portion 24 includes a 1 st peripheral edge region 24a on the upper surface 16a and a 2 nd peripheral edge region 24b on the lower surface 16 b.

The 1 st peripheral region 24a is formed continuously and flatly from the central region 23a, and is located on the same plane as the central region 23a when not worn as shown in fig. 5A.

The 2 nd peripheral edge region 24b is a region extending outward in the lateral direction Y from an end of the side surface region 23 e.

In the wearing state shown in fig. 5B, the intermediate core portion 21 is under pressure from the wearer in the thickness direction Z, i.e., toward the dressing side. Since a step is formed between the top surface region 23b as the high grammage portion 23 and the 2 nd peripheral edge region 24b as the low grammage portion 24 in the lower surface 16b, the 2 nd peripheral edge region 24b is pushed toward the side surface region 23 e. Thereby, the upper surface 16a is bent between the central region 23a and the 1 st peripheral region 24a, and the 1 st peripheral region 24a is pressed toward the end from the base connected to the central region 23 a. Thus, the 1 st peripheral edge portion 24a is deformed into a slant surface shape.

In other words, the low grammage portion 24 formed on the lateral Y-side portion of the high grammage portion 23 is pressed toward the dressing side by the pressure applied from the wearer when worn. Thereby, the high grammage portion 23 protruding toward the back sheet 13 is relatively pushed up toward the skin side, and is deformed so that the intermediate core portion 21 bulges toward the wearer side at the widthwise Y center portion. Thereby, the high grammage portion 23 is brought into close contact with the excretory region of the wearer.

The absorbent core 16 has no step on the upper surface 16a side, and the 1 st peripheral edge region 24a is deformed into an inclined surface shape continuing from the central region 23 a. This makes it difficult to form a gap between the upper surface 16a and the excretory region, and the sanitary napkin 1 has high conformability to the excretory region and high wearing comfort.

Further, in the above structure, the intermediate core portion 21 is formed to be narrow in width. Thus, in the sanitary napkin 1, the external force from the lateral direction Y applied by the legs of the wearer is alleviated.

In addition, the low grammage portion 24 functions as an easily deformable region in the intermediate core portion 21. In other words, when a large external force is applied in the lateral direction Y, the low grammage portion 24 having low rigidity is compressively deformed, and the energy of the external force is consumed. This suppresses deformation of the high grammage portion 23, and can maintain adhesion to the excretory region.

Further, the intermediate core portion 21 is formed to be narrow in width, whereby the compressive deformation of the low grammage portion 24 is less likely to be transmitted to the rear core portion 22 and the front core portion 20. Therefore, not only the excretion area of the wearer but also the rear and front sides thereof can be prevented from being separated from the wearer, and the fit can be improved.

[ planar shape of high grammage part ]

As shown in fig. 4, the high grammage portion 23 extends in the longitudinal direction X, but the transmission of the compression deformation of the low grammage portion 24 in the longitudinal direction X can be mitigated by the shape of the front and rear end portions thereof. The planar shape of the high grammage portion 23 is an XY plane shape, and is used as the planar shape of the top surface region 23 b.

The high grammage portion 23 includes a rear end portion 23d having a width dimension that gradually decreases toward the front end in the longitudinal direction X. In other words, the high grammage portion 23 is configured to gradually narrow and the low grammage portion 24 is configured to gradually widen in the rear portion of the intermediate core portion 21 as going toward the rear core portion 22.

In the absorbent core 16 having the above-described structure, the region in which deformation is easily caused gradually widens from the intermediate core portion 21 toward the rear core portion 22. Accordingly, when the low grammage portion 24 is compressively deformed by an external force from the lateral direction Y, the degree of compression is gradually reduced as it goes to the rear core portion 22, and the influence of the deformation can be effectively suppressed from being transmitted to the rear core portion 22. Thus, the fit in the rear of the excretion area is further improved.

In the high grammage portion 23, the front end portion 23c located forward in the longitudinal direction X may have a structure in which the width gradually decreases toward the front end in the longitudinal direction X.

Thus, as described above, the easily deformable region gradually widens from the intermediate core portion 21 toward the front core portion 20, and the influence of the compression deformation of the low grammage portion 24 is less likely to be transmitted to the front core portion 20. Therefore, the fit is further improved in front of the excretion area.

In fig. 4, the front end portion 23c and the rear end portion 23d have a circular arc shape or an elliptical arc shape. Accordingly, the width at the front ends of the front end portion 23c and the rear end portion 23d becomes 0, and therefore, the width of the low grammage portion 24 in the region adjacent to the rear core portion 22 can be made wider. Therefore, the compression deformation of the low grammage portion 24 is sufficiently relaxed, and the transmission of the compression deformation to the rear core portion 22 can be effectively suppressed.

The shapes of the front end 23c and the rear end 23d of the high grammage portion 23 are not limited to the above shapes.

For example, the front end 23c and the rear end 23d may have a triangular shape with an acute front end. Thus, the front end portion 23c and the rear end portion 23d have a shape in which the width gradually decreases toward the front end, and the width of the front end portion 23c and the width of the rear end portion 23d become 0. Therefore, the same operational effects as those of the front end portion 23c and the rear end portion 23d in fig. 4 can be obtained.

Alternatively, the front end portion 23c and the rear end portion 23d may have a trapezoidal shape including a side in the lateral direction Y at the front end, or may have a rectangular shape with rounded corners. Accordingly, the front end portion 23c and the rear end portion 23d also have a shape in which the width gradually decreases as going to the front end, and the external force damping action of the low grammage portion 24 can be improved.

The front end portion 23c and the rear end portion 23d may have a rectangular shape having substantially the same width as the whole, instead of having a shape in which the width gradually decreases toward the front end.

The length dimension of the high grammage portion 23 in the longitudinal direction X is not particularly limited, and may be formed over the entire length of the intermediate core portion 21 or may be formed in a part of the intermediate core portion 21.

In particular, by forming the high grammage portion 23 over the entire length of the intermediate core portion 21, the fit to the wearer and the liquid absorbency can be improved over the entire excretory region.

In addition, when the rear end portion 23d of the high grammage portion 23 is configured to be adjacent to the rear core portion 22 as described above, the transmission of the compression deformation to the rear core portion 22 can be further suppressed by providing the following tapered region (rear tapered region 22t) in the rear core portion 22.

[ Structure of tapered region ]

As shown in fig. 4, the rear core portion 22 includes a rear tapered region 22t formed adjacent to the intermediate core portion 21 and having a width dimension that gradually increases as one goes rearward in the longitudinal direction X.

The rear core portion 22 has a smaller grammage than the high grammage portion 23, and therefore is relatively easily deformed as compared with the high grammage portion 23.

In other words, in the absorbent core 16 having the above-described structure, the easily deformable region gradually widens as it goes further rearward in the longitudinal direction X from the boundary portion P2 contacting the rear end portion 23d of the high grammage portion 23. Accordingly, when the low grammage portion 24 is compressively deformed by an external force from the lateral direction Y, the compressive deformation is gradually relaxed in the rear core portion 22. Therefore, the transmission of the compressive deformation to the rear core portion 22 is further suppressed, and the fit in the rear of the excretion region is further improved.

In addition, the front core portion 20 may have the same tapered region. That is, the front core portion 20 may include a front tapered region 20t formed adjacent to the intermediate core portion 21 and having a width that gradually increases as it goes forward in the longitudinal direction X. This also suppresses the transmission of the compressive deformation in the lateral direction Y to the front core portion 20, and improves the fit in the front of the excretion area.

The outer edges of the rear tapered region 22t and the front tapered region 20t are not limited to a straight line, and may be curved. The rear tapered section 22t and the front tapered section 20t may be symmetrical in shape or asymmetrical in shape.

[ Structure of cored sheet ]

As shown in fig. 3, the absorbent body 11 has a core sheet 17 in addition to the absorbent core 16. The core-wrapped sheet 17 is wound in the transverse direction Y of the absorbent core 16 so as to wrap the front and back surfaces of the absorbent core 16. By providing the core sheet 17, the structure of the absorbent core 16 can be protected during circulation or wearing, and the above-described cushioning effect against external force can be enhanced. The details thereof will be described below.

As described above, the core-spun sheet 17 is formed of paper, nonwoven fabric, or the like. That is, the core sheet 17 is made of a sheet material having sufficiently low rigidity as compared with the absorbent core 16. The core-spun sheet 17 may be formed of 1 sheet or a plurality of sheets. The core sheet 17 may be bonded to the front sheet 12 and the back sheet 13 with an adhesive or the like applied in a predetermined pattern, for example.

The width dimension of the core-spun piece 17 in the transverse direction Y is, for example, a constant value in the longitudinal direction X, but is not limited thereto, and may be a smaller or larger width dimension in the middle in the longitudinal direction X.

The longitudinal dimension of the core-wrapped sheet 17 in the longitudinal direction X is formed to be equal to the longitudinal dimension (total length) of the absorbent core 16 in the longitudinal direction X, but is not limited thereto, and may be longer or shorter than the total length of the absorbent core 16.

As shown in fig. 6, the core-wrapped sheet 17 has a core-wrapped portion 17c that wraps each portion of the absorbent core 16 and an extended portion 17s that extends outward in the lateral direction Y of the low grammage portion 24. The general shapes of the absorbent core 16 and the high and low grammage portions 23, 24 are shown by broken lines in fig. 6.

The core sheet 17 is made of a sheet having sufficiently low rigidity compared to the absorbent core 16, and therefore, covers the absorbent core 16 in a shape corresponding to the shape of the absorbent core 16.

As shown in fig. 5, the extending portion 17S is configured to define a space region S in a tapered shape forming the intermediate core portion 21. That is, no core material constituting the absorbent core 16 exists inside the extension portion 17 s. However, although the main body of the core material is not present in the space region S, fibers protruding outward from the periphery of the absorbent core 16 and a part of the core material separated from the absorbent core 16 may be present locally.

In the absorbent body 11, the extended portions 17s are configured to have a lower grammage than the low grammage portions 24, and are configured to be more easily deformable.

As shown in fig. 5, when worn, the extended portion 17s of the core-spun piece 17 receives pressure from the wearer downward in the thickness direction Z (the dressing side). The core sheet 17 has sufficiently low rigidity compared to the absorbent core 16, and therefore the extended portion 17s maintains a state of being pressed along the wearing garment by the pressure. That is, the extension portion 17s of the core piece 17 is pressed downward in the thickness direction Z, and thereby the low grammage portion 24 located inside the core piece 17 is also maintained in a state pressed downward in the thickness direction Z.

As described above, the extending portion 17s of the core piece 17 is present further outside in the lateral direction Y of the low grammage portion 24, and thus the low grammage portion 24 can be prevented from returning to the shape before wearing by its own elastic force. This can maintain the state in which the high grammage portion 23 is relatively raised upward in the thickness direction Z. Therefore, even when the wearer moves, the close contact between the high grammage portion 23 and the excretory region can be maintained, and high contact performance can be maintained in the sanitary napkin 1.

[ Structure of groove ]

As shown in fig. 4, the absorbent core 16 is divided into blocks by the low grammage vertical groove portions 26, the boundary groove portions 27c, 27d, the annular groove portions 28, and the horizontal groove portions 29. These grooves have grooves that are open to the lower surface 16b of the absorbent core 16 and are formed upward in the thickness direction Z, and have a lower grammage than the surroundings.

The deformation of the absorbent core 16 during wearing can be more effectively controlled by these groove portions. The structure and operation of each groove will be described below.

(vertical groove part)

As shown in fig. 4, the absorbent core 16 has a low grammage longitudinal groove portion 26c formed in the widthwise Y central portion 22c of the rear core portion 22 and extending in the longitudinal direction X. Since the grammage and the rigidity have a correlation, the vertical groove portion 26c becomes a portion that is more easily deformed than the region other than the groove portion.

The lateral central portion 22c of the rear core portion 22 refers to a central portion of the rear core portion 22 when the rear core portion 22 is trisected in the lateral direction Y. On the other hand, the lateral portions 22d are portions on both sides of the rear core portion 22 in the lateral direction Y.

In the example shown in fig. 4, the longitudinal groove portion 26c is formed over the entire length of the rear core portion 22 in the longitudinal direction X, but may be formed in a part of the rear core portion 22.

The operation of the vertical groove 26c when worn will be described with reference to fig. 7.

As shown in the figure, the rear core 22 can face the buttocks H of the wearer when worn. The hip portion H has a hip slit H1 and has a shape that is divided in the right and left direction.

In the rear core portion 22, the vertical groove portion 26c having low rigidity is likely to become a starting point of deformation. Therefore, as schematically shown in fig. 7, the center portion 22c in the lateral direction Y where the vertical groove portion 26c is located in the rear core portion 22 protrudes upward in the thickness direction Z during wearing, and deforms along the hip slit H1. Therefore, the gap between the hip slit H1 of the wearer and the sanitary napkin 1 is reduced, and the fit of the sanitary napkin 1 at the rear of the excretion area can be improved. In addition, this can suppress the transmission leakage of the liquid due to the rear gap in the sanitary napkin 1.

In addition, the absorbent core 16 may have other vertical groove portions formed in the rear core portion 22 in addition to the vertical groove portion 26 c. The longitudinal grooves formed in the absorbent core 16 are collectively referred to as "longitudinal grooves 26". These vertical grooves 26 can impart flexibility to the absorbent core 16 and can improve the fit to the body of the wearer. The structure of the vertical groove portions 26 other than the vertical groove portion 26c will be described later.

(boundary groove part)

The absorbent core 16 further has boundary groove portions 27d of low grammage formed at the boundary between the intermediate core portion 21 and the rear core portion 22 and extending in the lateral direction Y. In the example shown in fig. 4, the boundary groove portion 27d is formed adjacent to the rear end portion 23d of the high grammage portion 23.

In the following description, the boundary portion P2 refers to a portion that does not belong to either the rear core portion 22 or the intermediate core portion 21. Similarly, the boundary portion P1 refers to a portion that does not belong to either the front core portion 20 or the intermediate core portion 21.

As described with reference to fig. 5, the high grammage portion 23 is deformed so as to rise upward in the thickness direction Z with respect to the rear core portion 22 having a low grammage even when worn. By forming the boundary groove portion 27d, it is possible to suppress the internal stress (tension) generated by the above-described deformation of the intermediate core portion 21 from being transmitted to the rear core portion 22 across the boundary portion P2. This can suppress deformation of the rear core portion 22 following deformation of the high grammage portion 23, and can easily induce desired deformation along the hip portion of the rear core portion 22 (see fig. 7). Therefore, the fitting property is also improved at the rear of the sanitary napkin 1.

Further, the absorbent core 16 may further include a boundary groove portion 27c of low grammage formed in the boundary portion P1 between the intermediate core portion 21 and the front core portion 20 and extending in the lateral direction Y. The boundary groove portion 27c is formed adjacent to the front end portion 23c of the high grammage portion 23, for example. With such boundary groove portions 27c, as with the boundary groove portions 27d, it is possible to suppress transmission of internal stress due to deformation of the intermediate core portion 21 to the front core portion 20, and it is possible to prevent deformation of the front core portion 20 following deformation of the high grammage portion 23.

(Ring groove portion)

The absorbent core 16 may further include an annular groove 28 formed along the outer edge of the high grammage portion 23 so as to annularly surround the periphery of the high grammage portion 23. By providing the annular groove portion 28, when a pressure is applied from the wearer to the lower side in the thickness direction Z, the annular groove portion 28 can serve as a starting point of bending, and deformation of the low grammage portion 24 in the lower side in the thickness direction Z is more likely to occur.

(horizontal groove part)

The absorbent core 16 further includes a plurality of low-grammage lateral groove portions 29 formed in the rear core portion 22 so as to intersect the longitudinal groove portions 26c and extend in the lateral direction. In the rear core portion 22 shown in fig. 4, 5 lateral groove portions 29 are arranged at equal intervals, but the number and arrangement of the lateral groove portions are not limited to this.

In addition, the absorbent core 16 may have lateral groove portions 29 formed in the front core portion 20 and the intermediate core portion 21 in addition to the lateral groove portions 29. These transverse groove portions 29 can impart flexibility to the absorbent core 16 and improve the fit to the body of the wearer. The structure and the like of these horizontal grooves 29 will be described later.

As described above, since the grammage and the rigidity have a correlation, the horizontal groove portions 29 can impart deformability to the absorbent core 16. On the other hand, a three-dimensional apron G is formed in the lateral Y-direction peripheral edge portion of the sanitary napkin 1. In the sanitary napkin 1, the elastic force of the elastic member 143 disposed in the three-dimensional apron G and the deformability of each of the transverse grooves 29 can be used to induce a curved shape that further improves the fit.

Hereinafter, the structure of the stereoscopic apron G and the like will be described.

[ Structure of three-dimensional fencing ]

As shown in fig. 2 and 3, the three-dimensional apron G has a folded-back region 141, a fixed end 142, and an elastic member 143. The three-dimensional apron G is constituted by the side sheet 14 in the present embodiment, but may be formed by a sheet other than the side sheet 14.

The folded-back region 141 is a portion folded back to the lateral Y outer side in the side sheet 14.

The fixed end portion 142 is an end portion on the inner side in the lateral direction Y of the three-dimensional apron G, and is a base portion of the three-dimensional apron G joined to the liquid receiving surface 12a of the front sheet 12. In the present embodiment, the fixing end portion 142 is joined to the front sheet 12 using the adhesive 15.

The elastic member 143 includes a plurality of linear elastic members arranged in the folded region 141 and capable of extending and contracting in the longitudinal direction X. The elastic member 143 is attached to the side sheet 14 stretched in the XY plane in a state of being elongated in the longitudinal direction X. Thus, when worn, the main body M can be bent so that the elastic member 143 contracts in the longitudinal direction X and is gently depressed by the liquid surface 12a, and the folded region 141 can rise in the thickness direction Z. The skin-side surface of the raised folded region 141 can be brought into contact with the skin of the wearer, and liquid leakage in the lateral direction Y can be prevented.

As shown in fig. 2, in the present embodiment, the three-dimensional enclosure G is disposed over the entire length in the longitudinal direction X of the main body M, and is configured to be at least partially erected.

The three-dimensional enclosure G has an erected region G1 and a non-erected region G2.

The rising region G1 is configured to be able to rise in the thickness direction Z. The rising region G1 is disposed across the intermediate core portion 21 to a part of the front core portion 20 and the rear core portion 22.

The non-standing region G2 is formed behind and in front of the standing region G1, respectively. The non-standing region G2 is joined to the outer surface of the side sheet 14 in the thickness direction Z in a state where the side sheet 14 is folded back, for example. Thus, the folded back region 141 is not erected in the non-erected region G2.

The elastic member 143 is disposed substantially in the entire three-dimensional enclosure G including the non-standing region G2, but may be disposed at least in the standing region G1. In fig. 2, the elastic member 143 in the non-standing region G2 is not shown.

[ positional relationship between horizontal groove and three-dimensional guard ]

As described above, the rear core portion 22 has 5 lateral groove portions 29. In fig. 8, the other grooves are omitted.

Referring to fig. 8, among the lateral groove portions 29, the front lateral groove portion 29 (hereinafter, referred to as a 1 st lateral groove portion 29c) extends in an area facing the rising area G1 of each of the pair of three-dimensional fences G, and the rear lateral groove portion 29 (hereinafter, referred to as a 2 nd lateral groove portion 29d) extends in an area facing the non-rising area G2 of each of the pair of three-dimensional fences G. Here, "the lateral groove portions extend in the standing region or the region opposed to the standing region" means that each lateral groove portion 29 extends in the lateral direction Y in a part or the whole of the region between the pair of standing regions G1 or the standing region G2 of the sanitary napkin 1, and also includes a form extending under the three-dimensional apron G or outside the three-dimensional apron G in the lateral direction Y.

More specifically, in the sanitary napkin 1 shown in fig. 8, of the lateral groove portions 29 formed in the rear core portion 22, the lateral groove portion 29 located closest to the front end side of the sanitary napkin 1 is the 1 st lateral groove portion 29c, and all the lateral groove portions 29 located closer to the rear end side of the sanitary napkin 1 than this are the 2 nd lateral groove portions 29 d. In the sanitary napkin 1, 3 of the 5 transverse groove portions 29 are located forward and 2 are located rearward in the rear core portion 22. Therefore, when the rear core portion 22 is divided into two parts in the longitudinal direction X, 1 of the lateral groove portions 29 located in the front half of the rear core portion 22 becomes the 1 st lateral groove portion 29c, and the remaining entire portions become the 2 nd lateral groove portions 29 d. Of course, the present invention is not limited to this, and all of the horizontal groove portions 29 located in the front half of the rear core 22 may be the 1 st horizontal groove portion 29 c. Further, only the transverse groove portion 29 located on the rearmost end side of the sanitary napkin in the rear half portion of the rear core 22 may be the 2 nd transverse groove portion 29 d.

In the sanitary napkin 1 shown in fig. 8, when worn, the elastic member 143 of the standing region G1 contracts in the longitudinal direction X and stands up in the thickness direction Z. The 1 st horizontal groove portion 29c has lower rigidity than the region of the absorbent core 16 other than the groove portion, and therefore bends from the bottom of the groove as a starting point with contraction of the elastic member 143. This allows the absorbent core 16 to bend upward behind the excretory region in which the 1 st horizontal groove portion 29c is present. Therefore, the sanitary napkin 1 is curved so as to wrap the excretory region, and can secure close contact with the excretory region of the wearer.

On the other hand, no elastic force appears in the non-standing region G2. Therefore, the flexibility of the rear core portion 22 can be improved by making the most of the deformability of each of the 2 nd horizontal groove portions 29d, and the rear core portion 22 can be gently curved so as to fit the buttocks.

Further, as described in fig. 7, the rear core portion 22 can be deformed so as to protrude along the hip joint by the longitudinal groove portion 26 c. By providing the 2 nd horizontal groove portion 29d in the region opposed to the non-standing region G2, the 2 nd horizontal groove portion 29d is less likely to be deformed by being bent in the longitudinal direction X, and the rear core portion 22 is not deformed so as to fit the hip joint. Therefore, the adhesiveness of the sanitary napkin 1 to the buttocks can be improved.

That is, the transverse groove portion 29 and the three-dimensional cuffs configured as described above can achieve both the attachment to the excretory region of the absorbent core 16 and the attachment to the buttocks at the rear of the excretory region.

From the viewpoint of the above-described close contact with the excretory region and the buttocks of the wearer, it is preferable that all of the lateral groove portions 29 in the region located in the latter half of the rear core portion 22 be the 2 nd lateral groove portions 29 d. From the same viewpoint, it is preferable that, of the horizontal groove portions 29 located in the front half region of the rear core portion 22, the horizontal groove portion 29 located in a region closer to the front end side 1/2 out of the front half region is the 1 st horizontal groove portion 29c, and the horizontal groove portion 29 located in the rear end side 1/2 is the 2 nd horizontal groove portion 29d, as viewed in the vertical direction X.

[ additional description of the present embodiment ]

The following complements the description of the present embodiment.

(widths of portions of absorbent core)

The width dimensions D1, D3 of the front core portion 20 and the rear core portion 22 are preferably 60mm or more and 100mm or less, and more preferably 70mm or more and 90mm or less.

The width dimension D2 of the narrowest portion of the intermediate core portion 21 is preferably 40mm or more and 75mm or less, and more preferably 50mm or more and 70mm or less.

(grammage of absorbent core)

The absorbent core 16 excluding the vertical groove portions 26, the boundary groove portions 27c, 27d, the annular groove portions 28, and the lateral groove portions 29 preferably has a grammage of 100g/m²Above and 1000g/m²Hereinafter, it is more preferably 150g/m²Above and 900g/m²The following.

Further, the grammage of the high grammage part 23 is preferably 400g/m²Above and 1000g/m²Hereinafter, it is more preferably 500g/m²Above and 900g/m²The following.

(method of measuring grammage of absorbent core)

The region to be measured of the absorbent core 16 was cut with a single-blade razor manufactured by featurer, and a small piece was obtained so as to have a predetermined area. The weight of these chips was measured using an electronic balance (electronic balance GR-300 manufactured by A & D, accuracy: 4 digits after decimal point). The grammage of the chips was calculated by dividing the obtained weight by the area of each chip. The average of the grammage of 5 chips was taken as the grammage of each part.

(thickness dimension of intermediate core)

The thickness dimensions of the high grammage part 23 and the low grammage part 24 can be set in consideration of the grammage.

The dimension in the thickness direction Z of the high grammage portion 23 is, for example, 3mm or more and 15mm or less, and preferably 5mm or more and 13mm or less.

The dimension in the thickness direction Z of the low grammage portion 24 is, for example, 2mm or more and 12mm or less, and preferably 3mm or more and 10mm or less.

(construction of vertical groove part, horizontal groove part, and annular groove part)

The absorbent core 16 may be provided with longitudinal grooves 26 extending in the longitudinal direction X, in addition to the longitudinal grooves 26c located in the widthwise Y center portion 22c of the rear core portion 22. In the following description, the vertical groove portion 26 in the center portion in the lateral direction Y is referred to as a 1 st vertical groove portion 26c, and the vertical groove portions 26 formed on both sides in the lateral direction Y are referred to as a 2 nd vertical groove portion 26d and a 3 rd vertical groove portion 26 e.

In the rear core portion 22 shown in fig. 4, the 2 nd longitudinal groove portion 26d is formed at the boundary between the central portion 22c and the side portion 22d, and the 3 rd longitudinal groove portion 26e is formed in each of the side portions 22 d. For example, the 2 nd vertical groove 26d may be formed in the central portion 22c or the side portions 22 d. The 1 st, 2 nd, and 3 rd vertical groove portions 26c, 26d, and 26e are arranged at equal intervals in the lateral direction Y, but may not be arranged at equal intervals.

Further, the groove widths of the 1 st, 2 nd and 3 rd vertical groove portions 26c, 26d, 26e may be different or the same. For example, the groove width of the 1 st vertical groove portion 26c is larger than the groove width of the vertical groove portion positioned in the side portion 22d, that is, the 3 rd vertical groove portion 26e in the present embodiment, whereby the deformation of the central portion 22c along the buttocks is further facilitated. In particular, by configuring the 1 st and 2 nd vertical groove portions 26c and 26d to have a larger groove width than the 3 rd vertical groove portion 26e, the deformation of the center portion 22c along the hip joint described with reference to fig. 7 can be further promoted.

The vertical groove 26 may be formed not only in the rear core portion 22 but also in the intermediate core portion 21 and the front core portion 20. In the example shown in fig. 4, the 1 st longitudinal groove portion 26c extends over the entire length in the longitudinal direction X of the absorbent core 16. The 2 nd and 3 rd longitudinal groove portions 26d and 26e extend over the entire length in the longitudinal direction X of the rear core portion 22 and the front core portion 20. The configuration of the vertical groove 26 is not limited, and may be formed in a part of each part in the vertical direction X, and the groove width may not be a constant value.

As described above, the lateral groove 29 extending in the lateral direction Y may be formed in the intermediate core portion 21 and the front core portion 20, for example, in addition to the rear core portion 22. The arrangement intervals of the horizontal grooves 29 are not limited to equal intervals, and may be different. The horizontal groove portions 29 are formed over the entire length of the absorbent core 16 in the lateral direction Y, but may be formed only in a part of the lateral direction Y. The width of each lateral groove 29 may be the same or different.

The groove widths of the vertical groove portion 26, the horizontal groove portion 29, and the annular groove portion 28 are preferably 0.5mm or more and 10mm or less, and more preferably 1mm or more and 5mm or less. The depth of the annular groove 28 is, for example, 0.5mm to 10mm, and the depth of the vertical groove 26 and the horizontal groove 29 is, for example, 0.5mm to 10 mm.

In addition to the above, the configuration such as the shape and arrangement of the vertical groove portions 26, the boundary groove portions 27c, 27d, the annular groove portions 28, and the horizontal groove portions 29 is not limited to the configuration shown in fig. 4, and may be appropriately set in accordance with the shape of the absorbent core 16, the required function, and the like. In the sanitary napkin 1, the absorbent core 16 may not have at least one of the vertical grooves 26, the boundary grooves 27c, 27d, the annular grooves 28, and the horizontal grooves 29.

The "low basis weight" of each of the grooves 26 to 29 is a concept including a mode in which the material of the absorbent core 16 is not present, in addition to a mode in which the material of the absorbent core 16 is present. In the embodiment in which the material of the absorbent core 16 is present in the grooves 26 to 29, the block-shaped portions of the absorbent core 16 located on both sides thereof are connected via the grooves 26 to 29, and therefore, the absorbent core 16 is less likely to wrinkle, break, or crack due to movement, and can be provided with flexibility, which is more preferable.

While the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and it is needless to say that various modifications can be made within the scope not departing from the gist of the present invention.

In the above embodiments, the sanitary napkin is shown as an example of the absorbent article, but is not limited thereto. The absorbent article of the present invention may be, for example, a urine absorption pad, a vaginal discharge pad, a disposable diaper, or the like. The present invention is particularly useful for pad-like absorbent articles such as sanitary napkins, urine pads, and vaginal secretion pads.

(1) An absorbent article including a liquid-permeable front surface sheet, a back surface sheet, and an absorber having an absorbent core and disposed between the front surface sheet and the back surface sheet, the absorbent article having a longitudinal direction corresponding to a front-back direction of a wearer and a lateral direction orthogonal to the longitudinal direction, the absorbent core having: a front core portion and a rear core portion located on both end portions sides in the longitudinal direction; and an intermediate core portion located between the front core portion and the rear core portion and having a narrower width than the front core portion and the rear core portion, the intermediate core portion including: a high grammage portion located at the lateral center and protruding toward the back sheet; and a low grammage portion having a lower grammage than the high grammage portion, formed at the lateral side portion of the high grammage portion.

(2) The absorbent article according to (1) above, wherein the high grammage portion includes a rear end portion, and a width of the rear end portion gradually decreases toward the longitudinal front end.

(3) The absorbent article according to (1) or (2), wherein the high grammage portion is formed over the entire length of the intermediate core portion, and the rear core portion includes a tapered region formed adjacent to the intermediate core portion, the tapered region having a width dimension that gradually increases as going rearward in the longitudinal direction.

(4) The absorbent article according to any one of (1) to (3), wherein the absorbent body further has a core-wrapped sheet, the core-wrapped sheet comprising: a core wrap section wrapping the absorbent core; and an extension portion extending to the laterally outer side of the low grammage portion.

(5) The absorbent article according to any one of (1) to (4), wherein the absorbent core further has a low grammage longitudinal groove portion formed in the widthwise central portion of the rear core portion and extending in the longitudinal direction.

(6) The absorbent article according to any one of (1) to (5), wherein the absorbent core further has a boundary groove portion of low grammage formed at a boundary portion between the intermediate core portion and the rear core portion and extending in the lateral direction.

(7) The absorbent article according to (5) or (6), wherein the absorbent article further comprises a pair of three-dimensional barriers provided at the lateral peripheral edge portions and extending in the longitudinal direction, the pair of three-dimensional barriers having: a standing region configured to be capable of standing in a thickness direction of the absorbent article; and a non-standing region formed rearward of the standing region, the absorbent core further including a plurality of horizontal groove portions formed in the rear core portion and extending in the lateral direction so as to intersect with the vertical groove portions, the plurality of horizontal groove portions being divided into: a front lateral groove portion extending in an area opposite to the rising area of each of the pair of three-dimensional skirts; and a rear lateral groove portion extending in a region opposite to the non-standing region of each of the pair of three-dimensional aprons.

(8) The absorbent article according to (7) above, wherein, when the rear core portion is divided into two in the longitudinal direction, the front transverse groove portion is provided on the foremost side of the transverse groove portion in the region of the front half portion of the rear core portion, and the remaining transverse groove portions are the rear transverse groove portions.

(9) The absorbent article according to (8) above, wherein all of the lateral groove portions in the region located in the rear half of the rear core portion are the rear lateral groove portions.

(10) The absorbent article according to (8) or (9), wherein the lateral groove portions in the region closer to the front end side 1/2 out of the region of the front half portion in the longitudinal direction among the lateral groove portions in the region of the front half portion of the rear core portion are the front lateral groove portions, and the lateral groove portions in the region located on the rear end side 1/2 are the rear lateral groove portions.

(11) The absorbent article according to any one of (1) to (10), wherein, of the respective width dimensions of the front core portion, the intermediate core portion, and the rear core portion, the difference in width dimensions in each region is controlled to be 20% or less, assuming that the minimum width in the lateral direction of each region is 100%.

(12) The absorbent article according to (11) above, wherein the difference in width dimension in each region is 10% or less, assuming that the minimum width in the lateral direction in the front core portion and the rear core portion is 100%.

(13) The absorbent article according to any one of (1) to (12) above, wherein the absorbent core has an annular groove portion formed along an outer edge of the high grammage portion so as to annularly surround a periphery of the high grammage portion.

(14) The absorbent article according to any one of (1) to (13) above, further comprising a pair of side sheets disposed around the lateral direction with the front sheet interposed therebetween, wherein the three-dimensional cuffs are provided with elastic members at folded-back portions of the side sheets in the lateral direction and are stretchable and contractible in the longitudinal direction.

(15) The absorbent article according to any one of (1) to (14) above, wherein the width dimensions of the front core portion and the rear core portion are 60mm or more and 100mm or less, preferably 70mm or more and 90mm or less.

(16) The absorbent article according to any one of (1) to (15) above, wherein the width dimension of the narrowest portion of the intermediate core portion is 40mm or more and 75mm or less, preferably 50mm or more and 70mm or less.

(17) The absorbent article according to any one of (1) to (16) above, wherein the grammage of the high grammage portion of the absorbent core is 400g/m²Above and 1000g/m²Hereinafter, it is more preferably 500g/m²Above and 900g/m²The following.

(18) The absorbent article according to any one of (1) to (17) above, wherein the dimension of the high grammage portion in the thickness direction is 3mm or more and 15mm or less, preferably 5mm or more and 13mm or less.

(19) The absorbent article according to any one of (1) to (18) above, wherein the dimension of the low grammage portion in the thickness direction is 2mm or more and 12mm or less, preferably 3mm or more and 10mm or less.

(20) The absorbent article according to any one of (7) to (10) above, wherein the groove width of the lateral groove portion is 0.5mm or more and 10mm or less, preferably 1mm or more and 5mm or less.

(21) The absorbent article according to (13) above, wherein the groove width of the annular groove portion is 0.5mm or more and 10mm or less, preferably 1mm or more and 5mm or less.

(22) The absorbent article according to (13) above, wherein the depth of the annular groove is 0.5mm to 10 mm.

(23) The absorbent article according to (5) above, wherein the depth of the longitudinal groove portion is 0.5mm or more and 10mm or less.

(24) The absorbent article according to any one of (7) to (10) and (20) above, wherein the depth of the transverse groove portion is 0.5mm or more and 10mm or less.

(25) The absorbent article according to any one of (1) to (24) above, wherein the absorbent core includes a plurality of longitudinal groove portions located in the rear core portion, and a groove width of the longitudinal groove portion located in the widthwise central portion is larger than a groove width of the longitudinal groove portion located in the widthwise side portion.

(26) The absorbent article according to (25) above, wherein, when the vertical groove portion in the widthwise central portion is a 1 st vertical groove portion and the vertical groove portions formed on both sides of the 1 st vertical groove portion in the widthwise direction are a 2 nd vertical groove portion and a 3 rd vertical groove portion in this order from the 1 st vertical groove portion, the width of the 1 st vertical groove portion and the 2 nd vertical groove portion is larger than the width of the 3 rd vertical groove portion.

(27) The absorbent article according to any one of (1) to (26) above, wherein the absorbent article is a sanitary napkin.

Examples

The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[ production of sanitary napkin for evaluation ]

(example 1)

A sanitary napkin (sanitary napkin) shown in FIG. 2 including the absorbent body shown in FIGS. 4 to 6 was produced.

Using a grammage of 16g/m²The paper-made core-wrapped sheet of (2) covers the entire outer surface of the absorbent core made of the wood pulp fiber as the hydrophilic fiber and the water-absorbent polymer to produce the absorbent body. Needle-leaved sun-cured kraft pulp (NBKP) was used as the wood pulp fiber. The water-absorbent polymer used was an acrylic acid polymer partial sodium salt (AQUALIC CAW, manufactured by JAN CATALYST CO., LTD.) having a gram weight of 24g/m²。

Regarding the length of the absorbent core, the total length was 324mm, the front core portion was 50mm, the middle core portion was 130mm, and the rear core portion was 144 mm.

Regarding the width of the absorbent core, 65mm was found in the middle core portion and 80mm was found in the front and rear core portions. Regarding the grammage of the wood pulp fibers, the high grammage part of the middle core portion was 700g/m²The low grammage is 200g/m²200g/m at the front core part and the rear core part²。

Regarding the width of the longitudinal groove portion of the absorbent core, the intermediate core portion was 1.5 mm. In the front core portion and the rear core portion, the 1 st longitudinal groove portion located in the widthwise central portion and the 2 nd longitudinal groove portions located on both sides thereof are 4mm, and the 3 rd longitudinal groove portion located further on both sides in the widthwise side portion is 1.5 mm. The width of the horizontal groove portion was 2mm as a whole, and the width of the annular groove portion was 1.5 mm.

(example 2)

A sanitary napkin of example 2 was produced in the same manner as in example 1, except that the width of the longitudinal grooves in the rear core portion was set to 1.5mm in all.

Comparative example

A sanitary napkin of comparative example was produced in the same manner as in example 2, except that the width of the absorbent core was set to 80mm uniformly over the entire length.

[ evaluation test ]

The sanitary napkins of examples 1 and 2 and comparative examples were evaluated for their fit to the crotch and buttocks of the wearer in a sleeping position by each method.

(measurement method of wrinkling Rate and liquid flow distance of sanitary napkin)

The sanitary napkins of the examples and comparative examples were worn on a lower body model that reproduces a walkable motion for wearing a sanitary napkin at the waist of an adult female. Before wearing, the width A of the sanitary napkin at a position corresponding to the central core portion is measured in advance. The walking motion is controlled by a motor linked with the leg.

The lower body model has a hollow structure and has a hole through which liquid can be discharged from the crotch portion corresponding to the vagina of a woman. The hole is connected with a tube through which liquid can pass, and is designed to allow a desired liquid to flow from the outside of the lower body model and to be discharged through the hole.

The sanitary napkin is worn on the lower body model by fixing the sanitary napkin to the side of the sanitary napkin facing the lower body model (the "underwear active guard" manufactured by kao corporation, L-size).

In a state where the sanitary napkin was worn, an operation of injecting 3g of equine defibrinated blood into the sanitary napkin for 4 seconds was performed 4 times at 3-minute intervals (0 minute after the start of measurement, 3 minutes after the start of measurement, 6 minutes after the start of measurement, and 9 minutes after the start of measurement), and a total of 12g of equine defibrinated blood was injected into each sanitary napkin. After the start of measurement, the legs of the lower body model were moved at a speed of 100 steps of walking for 1 minute for the first 5 minutes, and the legs of the lower body model were fixed in a split state with a crotch width of 42mm for the next 4 minutes.

The horse defibrinated blood was obtained by adjusting the ratio of blood cells to blood plasma of defibrinated horse blood (manufactured by Nippon Bio-test Co., Ltd.) so that the viscosity measured with a B-type viscometer (model TVB-10M, manufactured by Toyobo industries, Ltd., measurement conditions: spindle No.19, 30rpm, 25 ℃ C., 60 seconds) was 8 mPaS.

After the running, the worn sanitary napkin was removed from the model while maintaining its deformed state, and the width B of the sanitary napkin at the position corresponding to the central core portion was measured, and the wrinkling rate of the sanitary napkin was calculated by the following equation.

Wrinkling rate { (width a-width B)/width a } × 100

In addition, the liquid spreading distance in the longitudinal direction on the topsheet of the sanitary napkin was measured as the liquid flowing distance of the sanitary napkin using a metal ruler.

The measurement results are shown in table 1.

[ Table 1]

(method of measuring compressive force of sanitary napkin)

The sanitary napkins of the examples and comparative examples were fixed to the inside of a sanitary napkin (L-size, "manufactured by kao corporation) and worn on the lower body model.

Before measurement, a pressure sensor (a "small 3-axis force sensor USL 06-H5-50N" manufactured by TEC-GIHAN Co., Ltd.) was disposed between the hole of the crotch part of the lower body model to which the tube was connected and the leg base.

The leg-separating angle was set to 20 ° for each of the left and right sides, and after wearing the sanitary napkin, the leg-separating angle was changed to 5 °, and the value of the pressure sensor at the leg-separating angle of 5 ° was read. Each sample was subjected to 3 measurements, and the average value thereof was taken as the compression force of the sanitary napkin.

The measurement results are shown in table 1.

(method of measuring rigidity of rear portion of sanitary napkin)

The sanitary napkins of the examples and comparative examples were cut at the boundary between the central core portion (width 80 mm. times. length 100mm) and the rear core portion (width 80 mm. times. length 90mm), and the side containing the rear core portion was used as a measurement sample.

After each of the test specimens was stored in a laboratory at a temperature of 23 ℃ and a humidity of 50% for 24 hours, the rigidity value of the test specimen was measured according to the hand-feeling measuring apparatus (handle-o-meter) method (JIS L-1096). The fabric hand feeling measuring instrument uses a great-honor scientific fine machine to manufacture HOM-200 type.

The measurement sample was placed on the textile-touch measuring instrument so that the back sheet side of the measurement sample faced upward and the longitudinal direction of the sanitary napkin was parallel to the slit having a width of 40 mm. Then, the blade of the ejector was lowered at a constant speed of 200mm/min to a position corresponding to the 1 st longitudinal groove portion of the absorbent core, and the maximum value indicated by an indicator (load meter) was read. Each measurement sample was subjected to 3 measurements, and the average value of these measurements was taken as the flexural rigidity of the rear portion of the sanitary napkin.

The measurement results are shown in table 1.

(method of measuring gap between rear part of sanitary napkin and wearer)

The sanitary napkins of the examples and comparative examples were fixed to the inside of a pair of sanitary napkins (L-size, "Laurier active guard manufactured by kao corporation) and worn on a transparent model for wearing sanitary napkins that reproduces the waist of an adult female at bedtime.

After the sanitary napkin was worn, the gap between the model skin surface and the sanitary napkin surface was measured as the gap with the wearer using a metal ruler. The measurement position was the position where the hip skin surface of the transparent model and the surface of the sanitary napkin were farthest away from each other when viewed from the side in a state where the hip of the model was in contact with the bed surface (a state where the top was facing upward).

The measurement results are shown in table 1.

(measurement results of compression force and wrinkling Rate of sanitary napkin)

As shown in table 1, the compression force was 1.30N in the comparative example, but was 0.71N and 0.72N in examples 1 and 2, respectively, which are smaller values than the comparative example. From this, it was confirmed that, in the sanitary napkins of examples 1 and 2 in which the intermediate core portion had a narrowed shape, the compression force (resistance) against the external force in the direction of lateral compression was smaller than that of the sanitary napkin of the comparative example in which no narrowing was provided. It can thus be presumed that in the sanitary napkins of examples 1 and 2, the width in the crotch becomes narrow and the wrinkles are small when an external force is applied from both legs.

Actually, from the results obtained by calculating the crepe ratio of the sanitary napkin, the crepe ratio (crepe ratio) was 5.6% in examples 1 and 2, but 15.0% in comparative example, which is a larger value.

From these results, it was confirmed that in the sanitary napkins of examples 1 and 2, wrinkling of the intermediate core portion can be prevented and fit at the crotch of the wearer can be improved.

(measurement results of rigidity and gap in rear part of sanitary napkin)

As shown in table 1, the rigidity of the transverse center portion of the rear portion of the sanitary napkin in both example 2 and comparative example was 70gf, but the gap between the rear portion of the sanitary napkin and the wearer was 10mm in comparative example, and 5.7mm in example 2, unlike this. In example 1, the gap between the rear portion of the sanitary napkin and the wearer was 3.3 mm. This makes it possible to confirm that the sanitary napkins of examples 1 and 2 can suppress the occurrence of a gap between the wearer and the rear portion of the sanitary napkin in the sleeping position. In addition, it was confirmed that in the sanitary napkin of example 2, although the structure of the rear core portion was substantially the same as that of the comparative example, the gap could be significantly reduced. From this result, it was confirmed that by providing the narrowed portion in the intermediate core portion, a preferable deformation can be induced to the rear core portion.

Further, in example 1 in which the 1 st vertical groove portion in the widthwise central portion and the 2 nd vertical groove portions on both sides thereof are wider than the 3 rd vertical groove portion in the side portion, the gap can be further reduced as compared with example 2 in which all the vertical groove portions have the same width. This confirmed that the fitting property at the buttocks of the sanitary napkin was further improved by forming the 1 st and 2 nd vertical grooves in the transverse center portion and both sides thereof wider than the 3 rd vertical groove in the transverse side portion in the rear core portion.

(measurement of liquid flow distance)

As shown in Table 1, the liquid flow distance was 111mm in the comparative example, 67mm in the example 1 and 76mm in the example 2, in contrast to this. From the results, it was confirmed that in the sanitary napkins of examples 1 and 2, the liquid flow in the sleeping posture was suppressed, and the liquid leakage was effectively prevented. From the above results, it was confirmed that the sanitary napkins of examples 1 and 2 were improved in the adhesiveness of the whole sanitary napkin.

Description of the reference numerals

1 … … sanitary napkin (absorbent article)

11 … … absorbent body

12 … … front panel

13 … … back sheet

16 … … absorbent core

20 … … front core

21 … … intermediate core

22 … … rear core

23 … … high grammage part

24 … … low grammage part

Industrial applicability of the invention

According to the absorbent article of the present invention, the fit can be improved.

Claims (26)

1. An absorbent article including a liquid-permeable front surface sheet, a back surface sheet, and an absorber having an absorbent core and disposed between the front surface sheet and the back surface sheet, the absorbent article having a longitudinal direction corresponding to a front-back direction of a wearer and a lateral direction orthogonal to the longitudinal direction, the absorbent article characterized in that:

the absorbent core has:

a front core portion and a rear core portion located on both end portions sides in the longitudinal direction; and

a middle core portion located between the front core portion and the rear core portion and having a narrower width than the front core portion and the rear core portion,

the intermediate core includes:

a high grammage portion located at the lateral center and protruding toward the back sheet; and

a low grammage portion having a lower grammage than the high grammage portion, formed at the lateral side portion of the high grammage portion,

the absorbent body also has a core-spun sheet, the core-spun sheet comprising: a core wrap section wrapping the absorbent core; and an extension portion extending to the laterally outer side of the low grammage portion.

2. The absorbent article of claim 1, wherein:

the high grammage portion includes a rear end portion having a width gradually decreasing toward the longitudinal front end.

3. The absorbent article of claim 1 or 2, wherein:

the high grammage portion is formed over the entire length of the intermediate core portion,

the rear core includes a tapered region formed adjacent to the intermediate core, the tapered region having a width dimension that gradually increases toward the longitudinal rear.

4. The absorbent article of claim 1 or 2, wherein:

the absorbent core further has a low grammage longitudinal groove portion formed in the widthwise central portion of the rear core portion, extending in the longitudinal direction.

5. The absorbent article of claim 1 or 2, wherein:

the absorbent core further has a boundary groove portion of low grammage formed at a boundary portion of the intermediate core portion and the rear core portion, extending in the lateral direction.

6. The absorbent article of claim 4, wherein:

the absorbent article further includes a pair of three-dimensional containment flaps provided at the lateral peripheral edge portions and extending in the longitudinal direction,

the pair of stereoscopic enclosures have:

a standing region configured to be capable of standing in a thickness direction of the absorbent article; and

a non-standing region formed rearward of the standing region,

the absorbent core further has a plurality of lateral groove portions of low grammage formed in the rear core portion and extending in the lateral direction respectively so as to intersect the longitudinal groove portions,

the plurality of horizontal groove portions are divided into:

a front lateral groove portion extending in an area opposite to the rising area of each of the pair of three-dimensional skirts; and

and a rear lateral groove portion extending in a region opposite to the non-standing region of each of the pair of three-dimensional aprons.

7. The absorbent article of claim 6, wherein:

when the rear core portion is divided into two parts in the longitudinal direction, the front lateral groove portion is provided on the foremost side of the lateral groove portion in the region of the front half portion of the rear core portion, and the remaining lateral groove portion is the rear lateral groove portion.

8. The absorbent article of claim 7, wherein:

the lateral groove portions in the region of the rear half of the rear core portion are all the rear lateral groove portions.

9. The absorbent article of claim 7, wherein:

among the lateral groove portions in the region of the front half portion of the rear core portion, the lateral groove portion in a region closer to the front end side 1/2 out of the region of the front half portion in the longitudinal direction is the front lateral groove portion, and the lateral groove portion in a region located on the rear end side 1/2 is the rear lateral groove portion.

10. The absorbent article of claim 1 or 2, wherein:

the difference in width dimensions in each region among the respective width dimensions of the front core portion, the intermediate core portion, and the rear core portion is controlled to be 20% or less, assuming that the minimum width in the lateral direction of each region is 100%.

11. The absorbent article of claim 10, wherein:

the difference in width dimension in each region is 10% or less, when the minimum width in the lateral direction is defined as 100% in the front core portion and the rear core portion.

12. The absorbent article of claim 1 or 2, wherein:

the absorbent core has an annular groove portion formed along an outer edge of the high grammage portion so as to annularly surround a periphery of the high grammage portion.

13. The absorbent article of claim 1 or 2, wherein:

the absorbent article further includes:

a pair of side sheets disposed around the lateral direction with the front sheet interposed therebetween; and

a pair of three-dimensional skirts provided to the lateral peripheral edge portions and extending in the longitudinal direction,

the three-dimensional enclosure is provided with an elastic member at the transverse folded-back portion of the side sheet, and is stretchable in the longitudinal direction.

14. The absorbent article of claim 1 or 2, wherein:

the width dimensions of the front core part and the rear core part are 60mm to 100 mm.

15. The absorbent article of claim 1 or 2, wherein:

the width dimension of the narrowest portion of the intermediate core is 40mm to 75 mm.

16. The absorbent article of claim 1 or 2, wherein:

the grammage of the high grammage part of the absorbent core is 400g/m²Above and 1000g/m²The following.

17. The absorbent article of claim 1 or 2, wherein:

the dimension of the high grammage part in the thickness direction is more than 3mm and less than 15 mm.

18. The absorbent article of claim 1 or 2, wherein:

the dimension of the low grammage part in the thickness direction is more than 2mm and less than 12 mm.

19. The absorbent article of claim 6, wherein:

the width of the transverse groove part is more than 0.5mm and less than 10 mm.

20. The absorbent article of claim 12, wherein:

the groove width of the annular groove part is more than 0.5mm and less than 10 mm.

21. The absorbent article of claim 12, wherein:

the depth of the annular groove is 0.5mm to 10 mm.

22. The absorbent article of claim 4, wherein:

the depth of the longitudinal groove is 0.5mm to 10 mm.

23. The absorbent article of claim 6, wherein:

the depth of the horizontal groove part is more than 0.5mm and less than 10 mm.

24. The absorbent article of claim 1 or 2, wherein:

the absorbent core includes a plurality of longitudinal groove portions in the rear core portion,

the width of the longitudinal groove portion at the widthwise central portion is larger than the width of the longitudinal groove portion at the widthwise side portion.

25. The absorbent article of claim 24, wherein:

when the vertical groove portion at the widthwise central portion is a 1 st vertical groove portion and the vertical groove portions formed on both sides of the 1 st vertical groove portion in the widthwise direction are a 2 nd vertical groove portion and a 3 rd vertical groove portion in this order from the 1 st vertical groove portion, the widths of the 1 st vertical groove portion and the 2 nd vertical groove portion are larger than the width of the 3 rd vertical groove portion.

26. The absorbent article of claim 1 or 2, wherein:

the absorbent article is a sanitary napkin.

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