absorbent articles

Abstract

To provide an absorbent article which is thin, hardly causes twisting and wrinkles, and is excellent in wearing feeling.SOLUTION: An absorbent article 1 comprises an absorbent core 4 between a skin side sheet 2 and a non-skin side sheet 3, and has a vertical direction X and a lateral direction Y. The absorbent core 4 has a front region 41, an intermediate region 42 and a rear region 46 in the vertical direction X. The intermediate region 42 has a center region 43 located in a center part in the lateral direction Y, and side regions 45 located on both sides of the center region 43 and having a basis weight lower than that of the center region 43. The center region 43 has the basis weight of 500 g / m2 or less and a thickness of 3 mm or less, and one or both of the front region 41 and the rear region 46 is an easily deformed end region whose basis weight and density are lower than those of the side regions 45.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to absorbent articles such as sanitary napkins, panty liners, incontinence pads and the like. [Background technology]

[0002] Conventionally, in absorbent articles such as sanitary napkins, a technique has been known in which a raised portion that protrudes toward the wearer's skin is provided in the area positioned opposite the wearer's excretory area, thereby preventing leakage of excreted liquid from the excretory area by flowing down the skin or the surface of the absorbent article. The applicant also proposed an absorbent article in which the material forming the absorbent core located at the center-high portion is partially reduced to form low-basis-weight grooves. According to this absorbent article, the low-basis-weight grooves improve the fit to the concave portions of the body and also suppress the occurrence of discomfort caused by hardening of the absorbent core (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-104094 [Patent Document 2] Japanese Patent Application Publication No. 2019-103709 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for thin absorbent articles that are comfortable to wear, with the aim of allowing people to be active while wearing them. However, the inventors have found that when conventional absorbent articles having low basis weight grooves in the absorbent core are made thinner to improve wearing comfort, wrinkles or creases may occur in the areas in front of or behind the crowning part, or in the areas on both sides of the crowning part, causing discomfort. Patent Document 2 also does not mention any of these problems specific to thinning.

[0005] Therefore, an object of the present invention is to provide an absorbent article that is thin, does not easily become twisted, and is comfortable to wear. [Means for solving the problem]

[0006] The present invention relates to an absorbent article having a longitudinal direction X and a transverse direction Y, and including an absorbent core between a skin side sheet and a non-skin side sheet. The absorbent core preferably has a front region, a middle region, and a rear region in the longitudinal direction X, and the middle region preferably has a central region located at the center in the transverse direction Y, and side regions located on both sides of the central region and having a basis weight lower than that of the central region. 2 Preferably, the thickness is 3 mm or less. Preferably, one or both of the front region and the rear region are easily deformable end regions having a basis weight and density lower than those of the side regions. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an absorbent article that is thin, resistant to twisting and wrinkling, and provides excellent wearing comfort. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view showing a sanitary napkin according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a plan view showing the absorbent core of the sanitary napkin of FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 5 is a cross-sectional view showing an example of deformation of the rear region of the absorbent core when the sanitary napkin of FIG. 1 is being worn. [Figure 6] FIG. 6 is a plan view showing a preferred example of an integrated groove provided in the sanitary napkin shown in FIG. [Figure 7]FIG. 7 is a schematic cross-sectional view of an integrated groove. [Figure 8] 8(a) and 8(b) are schematic cross-sectional views showing the intermediate region of an absorbent core in a modified example of the sanitary napkin shown in FIG. 1, and correspond to FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will now be described based on preferred embodiments thereof with reference to the drawings. As shown in Fig. 1, a sanitary napkin 1 (hereinafter simply referred to as napkin 1) according to a first embodiment of the present invention has a longitudinal direction X and a transverse direction Y perpendicular to the longitudinal direction. The longitudinal direction X coincides with the front-to-back direction of a wearer when worn. The front side of the front-to-back direction corresponds to the wearer's abdomen, and the rear side of the front-to-back direction corresponds to the wearer's back. The napkin 1 has, in the longitudinal direction X, a front portion A, a portion B facing the excretory area, and a rear portion C. The portion B facing the excretory area is a portion that has a portion facing the wearer's excretory area (such as the vaginal opening) at the center in the transverse direction Y. The front portion A is located in front of the wearer's portion facing the excretory area B, and the rear portion C is located behind the portion B facing the excretory area. The napkin 1 of this embodiment has a longitudinally long absorbent main body 6 and a pair of wing portions 7 extending in the lateral direction Y from the absorbent main body 6.

[0010] The napkin 1 comprises a skin-side sheet 2 which forms a skin-contacting surface that faces the skin of the wearer when worn, a non-skin-side sheet 3 which forms a non-skin-contacting surface that faces the clothing such as shorts when worn, and an absorbent core 4 arranged between these two sheets. The skin-side sheet 2 comprises a liquid-permeable top sheet 2a and a pair of side sheets 2b, 2b joined to both sides thereof. The liquid-permeable top sheet 2a is arranged in the center of the diaper 1 in the lateral direction Y, over the entire length of the absorbent body 6. The side sheets 2b may have an elastic member (not shown) for forming a three-dimensional guard near the inner edge 21. When the side sheets 2b have an elastic member for forming a three-dimensional guard, when worn, a portion of the excretory part-facing portion B, a predetermined width from the inner edge 21, rises up and is separated from the top sheet 2a to form a three-dimensional guard. The non-skin side sheet 3 is formed from a water-repellent or liquid-impermeable sheet, and the non-skin-contacting surface of the non-skin side sheet 3 and one surface of the wing portions 7 are provided with adhesive portions (not shown) for fastening the napkin 1 to clothing such as shorts. The absorbent article of the present invention may not have wing portions 7, and the skin side sheet 2 may consist solely of a wide, liquid-permeable top sheet 2a.

[0011] In this embodiment, the absorbent core 4 is made of a fiber aggregate made of a fiber material such as pulp fiber, or a fiber aggregate to which a superabsorbent polymer is attached. The absorbent core 4 is covered on both the top and bottom surfaces with a core wrap sheet (not shown) made of tissue paper or a water-permeable nonwoven fabric. The core wrap sheet is used to prevent leakage of the material forming the absorbent core 4 and to improve the shape retention of the absorbent core 4. The skin-side sheet 2 and the core wrap sheet covering the skin-contacting side of the absorbent core 4, and the non-skin-side sheet 3 and the core wrap sheet covering the non-skin-contacting side of the absorbent core 4, are preferably bonded to each other with an adhesive applied in a pattern such as dots, spirals, or stripes.

[0012] As shown in FIG. 1, the absorbent core 4 in the napkin 1 has a shape that is elongated in the same direction as the longitudinal direction X of the napkin 1, and the longitudinal direction X of the absorbent core 4 and the longitudinal direction X of the napkin are synonymous. As shown in FIG. 2, the absorbent core 4 has a front region 41, a middle region 42, and a rear region 46 in the longitudinal direction X. The intermediate region 42 has a central region 43 located in the center of the absorbent core 4 in the lateral direction Y, and side regions 45, 45 located on both sides of the central region 43 and having a lower basis weight than the central region 43. As shown in Figure 2, the intermediate region 42 is a region in which the central region 43 and a pair of side regions 45, 45 having a lower basis weight than the central region 43 are arranged side by side in the lateral direction Y. The front region 41 is a region extending forward of the intermediate region 42, and the rear region 46 is a region extending rearward of the intermediate region 42. The basis weight of each portion of the absorbent core 4 refers to the basis weight of the material forming the absorbent core. The absorbent core 4 is formed as a single continuous piece by integral molding, and at least a portion of the thickness direction is continuous between the front region 41 and the intermediate region 42, between the intermediate region 42 and the rear region 46, and between the central region 43 and each of the pair of side regions 45, 45. The absorbent core 4 is continuous as a whole in a plan view and is not divided, and therefore has excellent shape retention, etc.

[0013] In this embodiment, the central region 43 of the absorbent core 4 has a thickness equal to or greater than that of the side regions 45, 45. More specifically, as shown in Figures 3 and 4, the central region 43 is thicker than the side regions 45, 45, and has protruding portions 43u that protrude above the upper surfaces 45s of the side regions 45. The presence of the protruding portions 43u below the skin-contacting sheet 2 of the napkin 1 forms protruding portions 17 that protrude toward the wearer's skin at the center of the skin-contacting surface in the transverse direction Y. At least a portion of the central region 43 in the longitudinal direction X, preferably more than half of its length in the longitudinal direction X, which has a basis weight higher than that of the side regions 45, is located in the excretion-area-facing portion B, and excreted liquid from the excretion area is quickly absorbed by the absorbent core 4, preventing leakage due to excreted liquid flowing along the skin surface or the surface of the napkin. From the viewpoint of further preventing such liquid leakage, the central region 43 preferably has a thickness equal to or greater than that of the side regions 45 , and is preferably thicker than the side regions 45 .

[0014] The central region 43 has a basis weight of 500 g / m 2 By designing the basis weight and thickness of the central region 43, which has a basis weight higher than that of the side regions 45, in this way, it becomes easier to obtain a napkin 1 that is thin and comfortable to wear. On the other hand, if the overall basis weight and thickness of the absorbent core 4 including the central region 43 is reduced in order to provide a thin absorbent article that is comfortable to wear, the area surrounding the central region 43 will be prone to twisting and wrinkling. In contrast to this, in the napkin 1 of this embodiment, the front region 41 and the rear region 46 of the absorbent core 4 are each formed as easily deformable end regions having a basis weight and density lower than the side regions 45 .

[0015] The basis weight of the central region 43 is set to 500 g / m from the viewpoint of reducing the thickness of the napkin. 2 and preferably 450 g / m 2 or less, more preferably 350 g / m 2 From the viewpoint of ensuring absorption performance, it is preferably 100 g / m 2 More preferably, 150 g / m 2 More preferably, it is 175 g / m or more. 2 That's all. The thickness of the central region 43 is 3 mm or less, preferably 2.5 mm or less, from the viewpoint of reducing the thickness of the napkin, and is preferably 0.5 mm or more, more preferably 1.0 mm or more, from the viewpoint of preventing twisting.

[0016] The effect of at least one of the rear region 46 and the front region 41 being an easily deformable end region having a basis weight and density lower than those of the side regions 45 will be described. When the rear region 46 or the front region 41 is the easily deformable end region, the rigidity of the side regions 45 is higher than that of the rear region 46 or the front region 41, at least in the lateral direction Y. Therefore, even if pressure is applied to the absorbent core 4 from both sides in the lateral direction Y while wearing the napkin 1, the side regions 45 are less likely to undulate in the lateral direction Y. Furthermore, the side regions 45 maintain a relatively flat shape, which makes it easier to transmit pressure applied to the absorbent core 4 from both sides in the lateral direction Y to the central region 43. Therefore, the cross section of the absorbent core 4 along the lateral direction Y is more likely to deform so that the central region 43 located in the center of the lateral direction Y protrudes toward the wearer, thereby improving the fit to the wearer's recesses, such as the liquid excretion area. When both the rear region 46 and the front region 41 are the easily deformable end region, this effect is further improved.

[0017] Furthermore, when the rear region 46 is the easily deformable end region, the rigidity of the rear region 46 is lower than that of the side regions 45, and the rear region 46 therefore easily deforms to conform to the uneven shape of the wearer's skin. For example, as shown in Fig. 5, the cross-sectional shape of the rear region 46 in the transverse direction Y easily deforms to conform to the shape of the wearer's intergluteal cleft 9 and its surroundings. Since the rear region 46 easily deforms to conform to the uneven shape of the wearer's skin, undesirable twisting or buckling is prevented in the rear region 46.

[0018] Furthermore, when the front region 41 is the easily deformable end region, the rigidity of the front region 41 is lower than that of the side regions 45, and the front region 41 is therefore more likely to deform to a shape that conforms to the unevenness of the wearer's skin. Because the front region 41 is more likely to deform to a shape that conforms to the unevenness of the wearer's skin, undesirable twisting or buckling is prevented from occurring in the front region 41.

[0019] According to the napkin 1 of this embodiment, due to these mutually different actions, both the side region existing portion 15 containing the side region 45 and the end region existing portion 11 or 16 containing the easily deformable end region, i.e., the rear region 46 or the front region 41, are less likely to crease or wrinkle due to the mutually different effects. As a result, the napkin 1 of this embodiment is thin yet less likely to crease or wrinkle, and provides an excellent wearing comfort.

[0020] According to the napkin 1 of this embodiment, as described above, both the front region 41 and the rear region 46 are easily deformable end regions having a lower basis weight and density than the side regions 45, and therefore, creases and wrinkles are less likely to occur in either the end region existing portion 11 in which the front region 41 resides or the end region existing portion 16 in which the rear region 46 resides, making it even easier to achieve a thinner napkin without compromising the wearing comfort.

[0021] When one or both of the rear region 46 and the front region 41 are easily deformable end regions, in order to prevent deformation of the easily deformable end region from inducing deformation of the intermediate region 42, the ratio of the basis weight of the easily deformable end region, that is, the rear region 46 or the front region 41, to the basis weight of the side region 45 is preferably 30% or more, more preferably 50% or more, and also preferably 75% or less, more preferably 70% or less, and also preferably 30% or more and 75% or less, more preferably 50% or more and 70% or less. When one or both of the rear region 46 and the front region 41 are easily deformable end regions, in order to prevent deformation of the easily deformable end region from inducing deformation of the intermediate region 42, the ratio of the density of the easily deformable end region, that is, the rear region 46 or the front region 41, to the density of the side region 45 is preferably 30% or more, more preferably 50% or more, and also preferably 75% or less, more preferably 70% or less, and also preferably 30% or more and 75% or less, more preferably 50% or more and 70% or less.

[0022] Furthermore, when the rear region 46 is an easily deformable end region, setting the ratio of the basis weight or density within the above range, particularly 30% to 75%, makes it easier for the rear region 46 to deform so as to gently wrap around the buttocks, and when in a sitting position, the deformation force applied to the rear region 46 is less likely to be transmitted to the middle region 42, and even if it is transmitted, it is less likely to induce deformation in the middle region 42, making it possible to more reliably prevent discomfort while wearing the garment.

[0023] As described above, the side regions 45 have a lower basis weight than the central region 43. From the viewpoint of providing a certain degree of rigidity to the side regions 45 to prevent twisting while suppressing the basis weight and thickness of the central region 43, the ratio of the basis weight of the side regions 45 to the basis weight of the central region 43 is preferably 20% or more, more preferably 30% or more, and preferably 90% or less, more preferably 80% or less, and also preferably 20% or more and 90% or less, more preferably 30% or more and 80% or less.

[0024] The density of the central region 43 is preferably equal to or greater than the density of the side regions 45. By making the rear region 46 or the front region 41 an easily deformable end region and making the density of the central region 43 equal to or greater than that of the side regions 45, it is possible to prevent twisting of the rear region 46 or the front region 41, and also to prevent twisting of the intermediate region 42. The phrase "the density of the central region 43 is equal to that of the side regions 45" means that the density of the central region 43 is within ±30% of the density of the side regions 45, i.e., the density of the central region 43 is 70% or more and 130% or less of the density of the side regions 45. The phrase "the density of the central region 43 is equal to or greater than that of the side regions 45" means that the density of the central region 43 is more than 100% of the density of the side regions 45. Therefore, the phrase "the density of the central region 43 is equal to or greater than the density of the side regions 45" means that the density of the central region 43 is 70% or more of the density of the side regions 45. From the viewpoint of preventing the above-mentioned twisting, the ratio of the density of the central region 43 to the density of the side regions 45 is preferably 70% or more, more preferably 90% or more, and is preferably 200% or less, more preferably 150% or less, and is preferably 70% or more and 200% or less, more preferably 90% or more and 150% or less.

[0025] The thickness of the central region 43 is preferably equal to or greater than the thickness of the side regions 45. By making the rear region 46 or the front region 41 an easily deformable end region and making the central region 43 equal to or greater than the thickness of the side regions 45, it is possible to prevent twisting of the rear region 46 or the front region 41, and also to prevent twisting of the intermediate region 42. From this viewpoint, the ratio of the thickness of the central region 43 to the thickness of the side regions 45 is preferably 100% or more, more preferably 130% or more, and is preferably 400% or less, more preferably 300% or less, and is preferably 100% or more and 400% or less, more preferably 130% or more and 300% or less.

[0026] In this embodiment, as shown in Figure 2, low basis weight lateral grooves 52 extending in the lateral direction Y are formed in the central region 43 and the side regions 45 of the absorbent core 4. A plurality of low basis weight lateral grooves 52 are formed at intervals in the longitudinal direction X. Each low basis weight lateral groove 52 has a portion 53 located in the central region 43 and a portion 55 located in the side regions 45, and these portions 53, 55 are aligned in the lateral direction Y to form a linear low basis weight lateral groove 52 extending in the lateral direction Y. The length of the low basis weight lateral groove 52 in the lateral direction Y is preferably 90% or more, more preferably 100%, of the length of the absorbent core 4 in the lateral direction Y. The portions 53, 55 do not have to be aligned. For example, the central region 43 and the side regions 45 may each have low-basis-weight lateral grooves extending in the transverse direction Y, offset in the longitudinal direction X. Alternatively, one or both of the portions 53, 55 may be inclined at an angle of less than 45 degrees, preferably less than 30 degrees, to the transverse direction Y, or may be curved. The low-basis-weight lateral grooves 52a formed at the boundary between the front region 41 and the central region 43 and the low-basis-weight lateral grooves 52c formed at the boundary between the rear region 46 and the central region 43 may be inclined or curved relative to the transverse direction Y, as with the portions 53, 55, but preferably extend along the width direction Y, and more preferably parallel to the width direction Y. On the other hand, in the rear region 46 or the front region 41, which are the easily deformable end regions, such low basis weight lateral grooves extending in the lateral direction Y are not formed.

[0027] In this embodiment, as shown in Fig. 2, low basis weight longitudinal grooves 51 extending in the longitudinal direction X are formed in the central region 43 of the absorbent core 4 along a center line CL that bisects the central region 43 in the transverse direction Y. More specifically, the low basis weight longitudinal grooves 51 are formed so as to overlap with the center line CL that bisects the central region 43 in the transverse direction Y. The length of the low basis weight longitudinal grooves 51 in the longitudinal direction X is preferably 90% or more, more preferably 100% or more, of the length of the central region 43 in the longitudinal direction X. 2, it is most preferable that the low basis weight longitudinal grooves 51 overlap with the center line CL that divides the central region 43 into two equal parts in the transverse direction Y, but the embodiment in which the low basis weight longitudinal grooves 51 are formed along the center line CL also includes a case in which at least one or both of the side edges of the low basis weight longitudinal grooves 51 extending in the longitudinal direction X are spaced apart from the center line CL by 8 mm or less. However, it is preferable that the low basis weight longitudinal grooves 51 overlap with the center line CL, and it is even more preferable that the center line of the low basis weight longitudinal grooves 51 overlap with the center line CL.

[0028] The low basis weight lateral grooves 52 are formed by reducing the basis weight of the material forming the absorbent core compared to the adjacent portions on both sides of the low basis weight lateral grooves 52 . More specifically, the portion 53 of the low-basis-weight lateral groove portion 52 located in the central region 43 has a bottom 52b with a lower basis weight than the high-basis-weight portions located on either or both of the front and rear sides of the portion 53, and a groove-like recess is formed on the skin-contacting surface side of the bottom 52b. Similarly, the portion 55 of the low-basis-weight lateral groove portion 52 located in the side region 45 has a bottom 52b with a lower basis weight than the high-basis-weight portions located on either or both of the front and rear sides of the portion 55, and a groove-like recess is formed on the skin-contacting surface side of the bottom 52b. The low basis weight vertical groove section 51 is formed by reducing the basis weight of the material forming the absorbent core compared to the adjacent sections on both sides of the low basis weight vertical groove section 51. That is, the low basis weight vertical groove section 51 has a bottom section 51b with a lower basis weight than the high basis weight sections located on both sides of the low basis weight vertical groove section 51, and a groove-shaped recess is formed on the skin-contacting surface side of the bottom section 51b.

[0029] By arranging the low basis weight horizontal grooves 52 in the central region 43 and the side regions 45, combined with the rear region 46 or the front region 41 being an easily deformable end region, excreted liquid is retained in the intermediate region 42, while the rear region 46 or the front region 41, which is an easily deformable end region, rises up in front of and behind the intermediate region 42 to follow the curved shape of the body and deforms to encase the intermediate region 42, thereby improving leakage prevention performance.

[0030] Furthermore, by providing the low basis weight longitudinal grooves 51 in the central region 43, the intermediate region 42 bends near its center, and the cross-sectional shape along the lateral direction Y is easily deformed into a convex shape facing the liquid discharge area. Furthermore, the low basis weight lateral grooves 52 cooperate with the low basis weight longitudinal grooves 51 to easily deform the central region 43, the side regions 45, and their adjacent regions in front and behind them into a shape that conforms to the complex unevenness of the skin, while the rear region 46 and the front region 41, which are easily deformable end regions, are less susceptible to deformation near the intermediate region 42. Therefore, for example, the region on the rear region 46 side deforms to wrap a wide area of ​​the buttocks in a large, rounded shape, providing a sense of security to the wearer.

[0031] In this embodiment, the side regions 45 have low basis weight lateral grooves 52 but do not have low basis weight grooves extending in the longitudinal direction X. Therefore, the side regions 45 maintain resistance to loads from the outside in the lateral direction Y, and are therefore less likely to undulate in the lateral direction Y. Furthermore, since the front region 41 and the rear region 46 do not have low basis weight grooves such as the low basis weight horizontal grooves 52 and the low basis weight vertical grooves 51, deformation of the side regions 45 is more easily suppressed.

[0032] 2 and 3, the low basis weight lateral grooves 52 in this embodiment include a low basis weight lateral groove 52a formed at the boundary between the front region 41 and the central region 43, and a low basis weight lateral groove 52c formed at the boundary between the rear region 46 and the central region 43. The low basis weight lateral grooves 52a and 52c are formed so that the basis weight of the bottom of each groove is lower than the basis weight of one or both of the adjacent portions on either side of each groove. The low basis weight lateral grooves 52a and 52c, one of which is the central region 43, are low basis weight lateral grooves 52 formed in the central region 43 and the side regions 45. Therefore, in this embodiment, the front region 41 and the rear region 46 of the absorbent core 4 do not have low basis weight lateral grooves 52 extending in the lateral direction Y.

[0033] 2 and 4, the absorbent core 4 in this embodiment has an annular low basis weight groove 56 around the central region 43. The annular low basis weight groove 56 has a bottom with a basis weight lower than that of the adjacent portions on both sides of the groove. The annular low basis weight groove 56, one of which is the central region 43, is formed in the central region 43.

[0034] 6 and 7, the napkin 1 of this embodiment has an integration groove 8 in which the topsheet 2a serving as the skin side sheet 2 is recessed together with the absorbent core 4. The integration groove 8 is not shown in FIG. The integrated groove 8 is formed by embossing and compressing the topsheet 2a side while the topsheet 2a and absorbent core 4 are overlapping, and is more compact than both sides of the integrated groove 8. By providing the integrated groove 8 and controlling the diffusion or diffusion direction of excrement, the leakage prevention effect can be improved.

[0035] 6 includes a pair of side grooves 81, 81 extending in the longitudinal direction X on both sides of the napkin 1 along the longitudinal direction X, a front groove 82 located in the end region existing portion 11 containing the front region 41 of the absorbent core 4 and having a shape convex toward the front of the napkin 1, and a rear groove 83 located in the end region existing portion 16 containing the rear region 46 of the absorbent core 4 and having a shape convex toward the rear of the napkin 1. The front groove 82, the pair of side grooves 81, 81 and the rear groove 83 are continuous in a ring shape in a plan view and form an annular groove surrounding the periphery of the central region existing portion 13 containing the central region 43 of the absorbent core 4. 6 includes a front laterally extending groove 84 extending from the junction between the front groove 82 and the side groove 81 toward the center in the lateral direction Y of the absorbent core 4, and a rear laterally extending groove 85 extending from the junction between the rear groove 83 and the side groove 81 toward the center in the lateral direction Y of the absorbent core 4. The rear laterally extending groove 85 has a shape that is convex toward the front of the napkin 1.

[0036] The napkin 1 of this embodiment has an absorbent core 4 configured as described above and an integration groove 8 shown in Fig. 6, where the depth of the integration groove in the side region existing portion 15 where the side regions 45 of the absorbent core 4 reside is deeper than the depth of the integration groove in the end region existing portion 16 where the rear region 46, which is an easily deformable end region, resides, and the depth of the integration groove in the side region existing portion 15 is deeper than the depth of the integration groove in the end region existing portion 11 where the front region 41, which is an easily deformable end region, resides. The depth T of the integration groove 8 is shown in Fig. 7. Fig. 7 shows a cross section perpendicular to the direction in which the integration groove extends in a plan view of the napkin. The depth T of the integrated groove 8 is measured in a portion that does not have a low basis weight groove portion such as a low basis weight horizontal groove portion, and in order to eliminate the influence of fluffing of the topsheet 2a, an acrylic plate is placed on the skin contact side and a tension of 0.5 cN / m on a flat surface. 2 With the load applied, the cross section perpendicular to the integrated groove is observed and measured using an enlarged photograph.

[0037] By forming the integrated grooves in the side region existing portions 15 deeper than the integrated grooves in the end region existing portions 11, 16, the side region existing portions 15 have a higher basis weight and density than the easily deformable end regions, which synergizes with the increased rigidity, thereby more reliably suppressing undesirable deformation of the side region existing portions 15 and more reliably preventing creases and wrinkles in the side region existing portions 15. On the other hand, the end region existing portions 11, 16 have a lower basis weight and density than the side regions 45, which synergizes with the flexibility, thereby improving the fit to the uneven contours of the wearer's body and suppressing undesirable deformation. This also more reliably prevents creases and wrinkles in the end region existing portions 11, 16. Grooves deeper than the integrated grooves in the side region existing portions 15 and the integrated grooves themselves may be present in only one of the end region existing portions 11 and 16.

[0038] The absorbent core 4 preferably has a thickness in the side regions 45 that is equivalent to the thickness of the easily deformable end regions. "Equivalent" means that the thickness of the side regions 45 is within ±10% of the thickness of the easily deformable end regions. Regardless of whether the front region 41 or the rear region 46 is an easily deformable end region, if the thickness of the side region 45 is equal to the thickness of the easily deformable end region, the above-mentioned effect can be more easily achieved when an integrated groove deeper than the integrated groove in the end region existing portions 11, 16 is formed in the side region existing portion 15.

[0039] Furthermore, when the thickness of the side regions 45 is the same as that of the easily deformable end regions, effects that can be achieved regardless of the integrated grooves include the ability to guide and draw excreted liquid into the side regions 45 rather than the easily deformable end regions, thereby preventing excreted liquid from reaching the front region 41 and / or rear region 46 in an excessive amount soon after wearing, and reducing the feeling of wetness and anxiety about leakage in the easily deformable end regions that have deformed to fit closely against the skin.

[0040] The portion having the integrated groove 8 in the side region existing portion 15 has a KES compression amount (load 25 gf / cm) measured by the following method, which is larger than the portion having the integrated groove 8 in the end region existing portion. 2 It is preferable that the change in thickness (mm) when compressed to 1 / 4, hereinafter referred to as "KES compression amount") is small. This improves the effect of preventing twisting and wrinkling by suppressing deformation of the side region existing portions 15, and also improves the ability of the end region existing portions 11, 16 to conform to the uneven shape of the wearer's body, thereby more effectively suppressing twisting and wrinkling of the end region existing portions 11, 16. To satisfy this condition, the basis weight and density of the side regions 45 and the easily deformable end regions 41, 46, the depth of the integrated groove 8 formed in the portion where the side regions 45 and the easily deformable end regions 41, 46 are present, etc. are appropriately adjusted. The KES compression amount (mm) of the part having the integrated groove 8 in the side region existing part 15 is preferably low from the viewpoint of preventing twisting by suppressing deformation, and is preferably 0.5 mm or more and 1.7 mm or less. On the other hand, the KES compression amount of the part having the integrated groove 8 in the end region existing part 11 or the end region existing part 16 is preferably 1.0 mm or more and 3.0 mm or less from the viewpoint of improving conformability to the body shape and wearing comfort. The difference in compression rate, which is the KES compression amount of the portion having the integrated groove 8 in the side region existing portion 15 minus the KES compression amount of the portion having the integrated groove 8 in the end region existing portion 11 or the end region existing portion 16, is preferably 0.10 mm or more and 0.25 mm or less.

[0041] [Method for measuring KES compression amount] The entire thickness of the area to be measured (side area 15, end area 11, or end area 16) is cut out from the napkin as a test piece, and the test piece is fixed to the test table of the measuring device with the skin contact surface facing up. A KES compression tester (KES-G5 compression tester, manufactured by Kato Tech Co., Ltd.) is used as the measuring device, and the area of ​​the test piece having the integrated groove 8 is compressed under the following conditions, and from the stress-strain at that time, a load of 25 gf / cm is calculated. 2 The compression element is positioned so that its center overlaps with the integrated groove 8. The compression amount (mm) is measured under a load of 25 gf / cm. 2 Thickness at load 0.5gf / cm 2 The thickness is calculated by subtracting the thickness at time. For each measurement site, similar measurements were made for three or more sites spaced apart from one another, and the average of the measured values ​​was taken as the compression amount of the site having the integrated groove 8 in that measurement site. Compression speed: 0.2 mm / sec (0.02 cm / sec) Compressor: 2cm 2 circular plate

[0042] When the end region existing portion 11 or the end region existing portion 16 has an integrated groove 8, it is preferable that the KES compression amount of the portion having the integrated groove 8 in the end region existing portions 11, 16 is within ±20% of the KES compression amount of the portion other than the portion having the integrated groove 8. With such a configuration, by not making the amount of compression when pressurized significantly different between the area having the integrated groove 8 and other areas, it becomes easy to achieve both prevention of leakage by controlling the diffusion of liquid with the integrated groove 8 and prevention of discomfort by improving conformability to the uneven shape of the wearer's body, such as the buttocks. From the same viewpoint, it is more preferable that the KES compression amount at the portion having the integrated groove 8 is within the range of ±15% of the KES compression amount at the portion other than the portion having the integrated groove 8 . The compression amount of the portion other than the portion having the integrated groove 8 is measured in the same manner as in the method for measuring the KES compression amount, except that pressure is applied to a portion of each measurement target portion (end region existing portion 11 or end region existing portion 16) cut out as a measurement piece, away from the integrated groove 8. For the portion other than the portion having the integrated groove 8, the average value of three or more portions spaced apart from each other is taken as the compression amount of the portion other than the portion having the integrated groove 8.

[0043] The KES compression amount of the end region existing portion 11 or the end region existing portion 16 at a portion other than the portion having the integrated groove 8 is preferably 3.0 mm or less, and more preferably 0.8 mm or more and 2.5 mm or less. In the end region existing portion 11 or the end region existing portion 16, the difference between the KES compression amount of the portion having the integrated groove 8 and the KES compression amount of the portion other than the portion having the integrated groove 8 is preferably as small as possible, and is preferably 0.5 mm or less, more preferably 0.2 mm or less.

[0044] In the napkin 1, of the front region 41 and the rear region 46 in the absorbent core 4, at least the rear region 46 is an easily deformable end region, and when the napkin 1 is twisted around a vertical axis along the longitudinal direction X and the torsional torque values ​​measured are compared, it is preferable that the torsional torque value of the intermediate region existing portion 12 in which the intermediate region 42 exists is greater than the torsional torque value of the end region existing portion 16 in which the rear region 46 exists. The intermediate region existing portion 12 is a portion in which the intermediate region 42 or the side regions 45 exist inside the absorbent article in the thickness direction. When the torsional torque values ​​have the above magnitude relationship, deformation of the article near the excretory part facing part B having the intermediate region 12 is suppressed, while the ability of the rear part C to conform to the body is improved, resulting in a thin article that is comfortable to wear. The torsional torque value of the end region existing portion 16 in which the rear region 46 exists is preferably as low as possible, from the viewpoint of increasing the flexibility of the end region existing portion 16, and is preferably 13 Nm or less, more preferably 12 Nm or less.

[0045] [Method for measuring torsional torque value] The measuring device used is a torsion torque device similar to that shown in Figure 2 of JIS K 7244-2. However, with regard to the measurement conditions, particularly the shape and dimensions of the sample, this method is performed assuming the actual usage of the absorbent article, so the sample shape and dimensions recommended in JIS K 7244-2 are not used, but rather sample shape and dimensions appropriate for such usage are used. Specifically, an absorbent article such as a napkin is used as the sample. The sample was clamped at two points separated from each other in the vertical direction by upper and lower clamps equipped with a measuring device to fix the sample, and the sample was rotated 60 degrees in opposite directions around the vertical direction as the rotation axis, and the maximum value of the torsional moment applied to the sample was taken as the measured value. During measurement, a 62g weight was placed on the balancing weight described in Figure 2 of JIS K 7244-2, and the measurement was performed under a tension of 62gf load in the vertical direction of the sample. The length between the clamps was 110mm when no tension was applied.

[0046] When measuring the torsional torque value of the intermediate region existing portion 12, the intermediate region existing portion 12 is located in the center between the clamps. In this measurement example, the intermediate region existing portion is present over almost the entire area between the clamps. When measuring the torsional torque value of the end region existing portion 16, the end region existing portion 16 is located approximately halfway between the clamps. In this measurement example, the intermediate region existing portion 12 is located approximately halfway between the clamps, and the end region existing portion 16 is located in the remaining half.

[0047] When at least one of the front region 41 and the rear region 46 in the absorbent core 4 of the napkin 1 is an easily deformable end region, the rigidity value of the end region existence portions 11, 16 in which the easily deformable end region exists, as measured by the handle-ometer method, is preferably 45 cN or less, more preferably 40 cN or less, from the viewpoint of making the end region existence portions 11, 16 flexible, and is preferably 5 cN or more, more preferably 10 cN or more, from the viewpoint of preventing damage to the front region 41 and the rear region 46. The method for measuring the stiffness value using the handle-ometer method will be described later in the examples.

[0048] When at least the front region 41 of the absorbent core 4 in the napkin 1 is an easily deformable end region, it is preferable that the difference in basis weight of the front region 41 in the lateral direction Y is small. Since the area around the wearer's sacrum has a relatively flat shape, if the difference in basis weight of the front region 41 in the lateral direction Y is small, the absorbent article will easily fit tightly around the wearer's sacrum. Specifically, as shown in FIG. 2, when the front region 41 is divided into three regions by dividing the length L1 of the front region 41 in the lateral direction Y into three equal parts, namely, a front central region 1b and a pair of front side regions 1a, 1c located on both sides thereof, the basis weight of each of the three regions is preferably within ±8% of the average basis weight of the three regions, and more preferably within ±4% of the average basis weight of the three regions. If the length L1 of the front region 41 in the horizontal direction Y varies along the vertical direction X, the length L1 of the front region 41 in the horizontal direction Y is defined as the length L1 at the point where the length L1 is greatest, and two boundary lines parallel to the vertical direction X are drawn to divide the length L1 into three equal parts, thereby dividing the front region 41 into the three regions.

[0049] When the absorbent core 4 of the napkin 1 has at least the rear region 46 as an easily deformable end region, and the length L6 of the rear region 46 in the transverse direction Y is divided into thirds to form a rear central region 6b and a pair of rear side regions 6a, 6c located on both sides of the rear central region 6b, the basis weight of the rear central region 6b is preferably higher than the basis weight of each of the pair of rear side regions 6a, 6c and higher than the average basis weight of the pair of rear side regions 6a, 6c by 5% or more. When the bulky absorbent core 4 comes into contact with the wearer's gluteal cleft 9 and the surrounding gluteal bulge, the portion of the absorbent core in contact with the surrounding area of ​​the gluteal cleft 9 undergoes significant deformation in the recessed direction, and the vicinity of the rear central region 6b facing the gluteal cleft becomes a shape that protrudes toward the gluteal cleft 9. This allows the entire buttocks to be in close contact with the end region existing portion 16 inside which the rear region is present, making it possible to more reliably prevent leakage of excretory fluid such as menstrual blood from the rear end. If the length L6 of the rear region 46 in the horizontal direction Y varies along the vertical direction X, the length L6 of the rear region 46 in the horizontal direction Y is defined as the length L6 at the point where the length L6 is greatest, and two boundary lines parallel to the vertical direction X are drawn to divide the length L6 into three equal parts, thereby dividing the front region 41 into the three regions.

[0050] [Method for measuring basis weight of each part of absorbent core] The basis weight of each portion of the absorbent core (e.g., central region 43, side regions 45, front region 41, rear region 46) is calculated by cutting out each portion including the low basis weight groove portions, such as low basis weight longitudinal groove portions 51 and low basis weight transverse groove portions 52, and measuring the mass of each portion using an electronic balance (A&D Electronic Balance GR-300, accuracy: four decimal places). The basis weight is calculated by dividing the calculated mass by the area of ​​each portion. [Method for measuring the thickness of each part of the absorbent core] When each part of the absorbent core (central region 43, side regions 45, front region 41, rear region 46, etc.) has low basis weight groove portions such as low basis weight longitudinal groove portions 51 and low basis weight transverse groove portions 52 or integrated grooves 8, the thickness is measured excluding the low basis weight groove portions and integrated grooves 8. For each part, the thickness is measured at five or more locations, and the arithmetic mean value of the thicknesses at five or more locations is taken as the thickness of each part. [Method for measuring density of each part of absorbent core] The density of each part of the absorbent core (central region 43, side regions 45, front region 41, rear region 46, etc.) is calculated by multiplying the thickness of each part determined by the thickness measurement method described above by the area of ​​each part to determine the volume of each part, and then dividing the mass of each part determined by the basis weight measurement method described above by the determined volume to determine the density of each part.

[0051] The basis weight of the front central region 1b and the pair of front side regions 1a, 1c located on either side of it was calculated by cutting out each region, measuring the mass of each region using an electronic balance (A&D Electronic Balance GR-300, accuracy: four decimal places), and dividing the calculated mass by the area of ​​each region. The average basis weight of these three regions 1a to 1c was the arithmetic mean of the basis weights calculated for each region. The basis weight of the rear central region 6b and the pair of rear side regions 6a, 6c located on either side of it was calculated by cutting out each region, measuring the mass of each region using an electronic balance (A&D Electronic Balance GR-300, accuracy: four decimal places), and dividing the calculated mass by the area of ​​each region. The average basis weight of these three regions 6a to 6c was the arithmetic mean of the basis weights calculated for each region.

[0052] The absorbent core 4 of the napkin 1 described above can be manufactured by fixing an air-impermeable member for forming a low basis weight groove portion to the bottom of the accumulation recess of the fiber stacking drum of the fiber stacking device, suctioning and depositing the absorbent core forming material supplied in a scattered state into the accumulation recess, and then releasing it from the mold.

[0053] The top sheet 2a, side sheet 2b, and non-skin side sheet 3 can be made of materials similar to those conventionally used in the relevant technical field, without any particular restrictions. For example, the top sheet 2a can be made of a liquid-permeable nonwoven fabric or a perforated film. The non-skin side sheet 3 can be made of a liquid-impermeable film made of synthetic resin or a water-repellent nonwoven fabric with high water pressure resistance, such as a spunbond-meltblown-spunbond laminated nonwoven fabric. The side sheet 2b can be made of a water-repellent nonwoven fabric with high water pressure resistance, such as a spunbond-meltblown-spunbond laminated nonwoven fabric. The absorbent core may be made solely of a fibrous material such as pulp fibers, or may contain both a fibrous material and a superabsorbent polymer. As the fibrous material and superabsorbent polymer, various materials conventionally used in absorbents for absorbent articles such as sanitary napkins, panty liners, and disposable diapers can be used without any particular limitation. For example, fibrous materials include staple fibers of cellulosic fibers such as pulp fibers, rayon fibers, and cotton fibers, and staple fibers of synthetic fibers such as polyethylene. These fibers can be used alone or in combination of two or more. The fibrous material is preferably entirely or partially made of pulp fibers, and the proportion of pulp fibers in the fibrous material is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, and even more preferably 100% by mass. In addition to the superabsorbent polymer, the absorbent core may also contain deodorants, antibacterial agents, and the like, as needed.

[0054] Although the present invention has been described above based on the preferred embodiments, the present invention is not limited to the above embodiments. For example, the absorbent core in the absorbent article of the present invention may not have any one or more of the low basis weight longitudinal grooves 51 and the low basis weight transverse grooves 52. In addition, the absorbent core in the absorbent article of the present invention may not have an annular low basis weight groove portion 56, as shown in Figure 8(a), or may have the same thickness in the central region 43 and the side regions 45, as shown in Figure 8(b). The absorbent article of the present invention may also have no integrated groove 8, or may have an integrated groove of a shape different from that shown in Fig. 6, such as an oval or oval shape in plan view, or may have multiple front or rear grooves. An oval shape is a shape surrounded by two parallel straight lines and front and rear arc-shaped lines that connect the two lines and curve convexly outward.

[0055] In addition, the absorbent core may have low basis weight groove portions such as low basis weight vertical groove portion 51 and low basis weight horizontal groove portion 52, in which the recesses open on the non-skin contacting side (non-skin side sheet side) instead of on the skin contacting side (skin side sheet side). The absorbent article of the present invention may be a sanitary napkin, or may be other absorbent articles such as panty liners (discharge sheets), incontinence pads, disposable diapers, etc.

[0056] The following supplementary notes are further disclosed regarding the above-described embodiment of the present invention. <1> an absorbent core between the skin-side sheet and the non-skin-side sheet; An absorbent article having a longitudinal direction and a transverse direction perpendicular to the longitudinal direction, The absorbent core has a front region, a middle region, and a rear region in the longitudinal direction, the intermediate region has a central region located at a center portion in the lateral direction, and side regions located on both sides of the central region and having a basis weight lower than that of the central region, The central region has a basis weight of 500 g / m 2 The thickness is 3mm or less, The absorbent article wherein one or both of the front region and the rear region are easily deformable end regions having a basis weight and density lower than those of the side regions. <2> the density of the central region is equal to or greater than the density of the side regions; <1> The absorbent article described above. <3> low basis weight lateral grooves extending in the laterally direction are formed in the central region and the side regions, and no low basis weight lateral grooves extending in the laterally direction are formed in the easily deformable end regions; <1> or <2> The absorbent article according to claim 1. <4> In the central region, low basis weight longitudinal grooves are formed along a center line that divides the central region into two equal parts in the horizontal direction, and the longitudinal grooves extend in the vertical direction. <3> The absorbent article according to claim 1. <5> The side region existing portion in which the side region exists and the end region existing portion in which the easily deformable end region exists have integrated grooves in which the skin side sheet is recessed together with the absorbent core, The depth of the integrated groove in the side region existing portion is deeper than the depth of the integrated groove in the end region existing portion. <1> ~ <4> 10. An absorbent article according to any one of the preceding items.

[0057] <6> The thickness of the side region is equal to the thickness of the easily deformable end region. <5> The absorbent article according to claim 1. <7> The side region existing portion in which the side region exists and the end region existing portion in which the easily deformable end region exists have integrated grooves in which the skin side sheet is recessed together with the absorbent core, The portion having the integrated groove in the side region existing portion has a larger KES compression amount (load 25 gf / cm ) than the portion having the integrated groove in the end region existing portion. 2 The change in thickness when compressed to <1> ~ <6> 10. An absorbent article according to any one of the preceding items. <8> The end region existing portion in which the easily deformable end region exists has an integrated groove in which the skin side sheet is recessed together with the absorbent core, In the end region, the KES compression amount of the portion having the integrated groove is within a range of ±20% of the KES compression amount of the portion other than the portion having the integrated groove. <1> ~ <7> 10. An absorbent article according to any one of the preceding items. <9> At least the rear region of the front region and the rear region is the easily deformable end region, When the torsional torque values ​​measured by twisting the absorbent article around a vertical axis along the vertical direction are compared, the torsional torque value of a middle region existing portion in which the longitudinal middle region exists is greater than the torsional torque value of an end region existing portion in which the rear region exists. <1> ~ <8> 10. An absorbent article according to any one of the preceding items. <10> At least the front region of the front region and the rear region is the easily deformable end region, When the length of the front region in the lateral direction is divided into three equal parts, i.e., a front central region and a pair of front side regions located on both sides thereof, the basis weight of each of the three regions is within ±8% of the average basis weight of the three regions. <1> ~ <9> 10. An absorbent article according to any one of the preceding items.

[0058] <11> At least the rear region of the front region and the rear region is the easily deformable end region, When the rear region is divided into three equal parts in the lateral direction into a rear central region and a pair of rear side regions located on both sides thereof, The basis weight of the rear central region is higher than the basis weight of each of the pair of rear side regions and is higher than the average basis weight of the pair of rear side regions by 5% or more. <1> ~ <10> 10. An absorbent article according to any one of the preceding items. <12> The ratio of the basis weight of the easily deformable end region to the basis weight of the side region is 30% or more and 75% or less. <1> ~ <11> 10. An absorbent article according to any one of the preceding items. <13> The ratio of the density of the easily deformable end region to the density of the side region is 30% or more and 75% or less. <1> ~ <12> 10. An absorbent article according to any one of the preceding items. <14> the side regions are free of low basis weight grooves extending in the machine direction; <1> ~ <13> 10. An absorbent article according to any one of the preceding items. <15> a circular low basis weight groove portion around the central region; <1> ~ <14> 10. An absorbent article according to any one of the preceding items. <16> There are no low basis weight groove portions in at least one of the front region and the rear region. <1> ~ <14> 10. An absorbent article according to any one of the preceding items. [Example]

[0059] The present invention will be further explained below with reference to examples, but the present invention is not limited to these examples in any way. Example 1 A napkin of the configuration shown in Fig. 1 was manufactured, including an absorbent core 4 of the configuration shown in Figs. 2 to 4. The absorbent core 4 was manufactured by the method described above, with a step provided within the collection recess. The absorbent core was a mixed stack containing 80% by mass of wood pulp and 20% by mass of absorbent polymer. The absorbent core 4 was wrapped in a core wrap sheet and placed between the skin side sheet 2 and the non-skin side sheet 3, to obtain the napkin of Example 1. The absorbent core 4 wrapped in the core wrap sheet and the skin side sheet 2 were overlapped, and an integration groove 8 was formed by embossing. The materials used for each component were those used in a commercially available sanitary napkin manufactured by Kao Corporation (product name: Laurier F Shiawase Suhada (total length 25 cm)), with only the basis weight of the wood pulp in the absorbent core changed as shown in Example 1 of Table 1.

[0060] (Examples 2 and 3 and Comparative Example 1) The napkins of Examples 2 and 3 and the comparative example were produced in the same manner as in Example 1, except that an absorbent core was produced in which the basis weight, thickness, and density values ​​of each part (central region, side region, front region, and rear region) were the values ​​shown in Table 1.

[0061] Table 1 shows the basis weight, thickness and density of each portion (central region, side region, front region and rear region) of the absorbent core used in the napkins of the Examples and Comparative Examples.

[0062] Evaluation 1: Measurement of torsional torque value Each of the napkins in Examples 1 to 3 and Comparative Example 1 was stored for 24 hours in a test room at a temperature of 23°C and a humidity of 50%, and then used as a measurement sample. The torsional torque value was measured under the same temperature and humidity conditions according to the method for measuring torsional torque value described above. The results are shown in Table 1. The results of Evaluation 1 shown in Table 1 reveal that, in the napkins of the Examples, the rear region has a lower basis weight and thickness (easily deformable end region) than the side regions, and therefore the torsional torque value of the rear region portion located on the buttocks side can be made smaller than the torsional torque value of the intermediate region portion 12 located in the excretory region-facing portion B, and the difference therebetween can be made larger. This makes the intermediate region portion 12 less likely to crease or wrinkle, while the rear region portion 16 has excellent conformability to the body's contours and is less likely to crease or wrinkle. The fact that the deformability of the side regions can be determined from the torsional torque value of the intermediate region portion 12 can be easily understood by comparing Comparative Example 1 with Examples 2 and 3 shown in Table 1. Comparative Example 1, Examples 2 and 3 have the same basis weight and density in the central region, but different basis weights in the side regions. Meanwhile, the density of the side regions is higher in Example 2 than in Comparative Example 1, and the same in Example 3. Looking at these results and the torsional torque values ​​for each, for the intermediate region, Example 2 had a larger value than Comparative Example 1, and Example 3 had approximately the same value. This result indicates that the density difference, rather than the difference in basis weight between the central region and the side regions, is more dominant in torsional torque. Therefore, these measurement results show that the torque value in the central region is dominated by the density factor of the side regions. Therefore, by comparing the torsional torque values ​​of the intermediate region and the front region, it can be seen that the rear region is a region that is more easily deformed than the side regions. In addition, since the stiffness values ​​measured by the handle-ometer method for the front region and the rear region are the same, it can be seen that the front region also has the same ease of deformation as the rear region.

[0063] (Examples 4 and 5) The napkins of Examples 4 and 5 were produced in the same manner as in Example 1, except that an absorbent core was produced in which the basis weight, thickness, and density values ​​of each part (central region, side region, front region, and rear region) were the values ​​shown in Table 2.

[0064] Evaluation 2: Measurement of KES compression amount The compression amount was measured for each of the napkins in Examples 3 to 5 and Comparative Example 1 according to the KES compression amount measurement method described above. The results are shown in Table 2. Each napkin was stored in a testing room at a temperature of 23°C and a humidity of 50% for 24 hours, and then used as a measurement sample.

[0065] The results of Evaluation 2 shown in Table 2 show that the KES compression amount of the portion having the integrated groove 8 in the side region existing portion 15 is smaller than the KES compression amount of the portion having the integrated groove 8 in the end region existing portion, and further, the difference between the KES compression amount of the portion having the integrated groove 8 in the end region existing portion and the KES compression amount of the portion other than the portion having the integrated groove 8 is small.

[0066] Evaluation 3: Stiffness value by handle-o-meter method In the napkins of Examples 1 to 3 and Comparative Example 1, the rigidity values ​​of the end region existing portion (front region existing portion) 11 in which the front region 41 exists and the end region existing portion (rear region existing portion) 16 in which the rear region 46 exists were measured using the handle-ometer method, and the results are shown in Table 1.

[0067] [Method for measuring stiffness using the handle-o-meter method] Each napkin in the Examples and Comparative Examples was stored for 24 hours in a test room at 23°C and 50% humidity, after which measurement samples were used and their stiffness was measured under the same temperature and humidity conditions according to the Handle-O-Meter method (JIS L-1096). A Handle-O-Meter, Model HOM-200, manufactured by Daiei Kagaku Seiki Seisakusho, was used. The measurement sample was placed on the test table with the non-skin-side sheet 3 facing downward and the longitudinal direction X of the napkin perpendicular to the longitudinal direction of a 40 mm-wide slit groove provided on the test table. The blade was lowered at a constant speed of 200 mm / min, and the maximum value indicated by the indicator (load meter) was read.

[0068] The results of evaluation 3 shown in Table 1 reveal that the anterior region portion and the posterior region portion of the napkin of the example have equally low deformability. This shows that the anterior region portion 11 has excellent fit to the sacrum, etc., and the posterior region portion 16 has excellent deformability to follow the contours of the body, and both regions are less likely to crease or wrinkle.

[0069] [Table 1]

[0070] [Table 2] [Explanation of symbols]

[0071] 1. Sanitary napkins (absorbent articles) 2 Skin side sheet 2a Surface sheet 2b Three-dimensional guard forming sheet 3 Non-skin side sheet 4 absorbent core 41 Anterior area (low density end area) 42 Mid-range 43 Central area 45 Side Area 46 Rear area (low density end area) 51 Low basis weight longitudinal grooves 52 Low basis weight horizontal groove section 56 Annular low basis weight groove 6. Absorbent body 7 Wing section 8 Integral groove 11 Front area existing part (end area existing part) 12 Intermediate area existence part 15 Side area presence part 16 Rear part existing part (end area existing part)

Claims

1. an absorbent core between the skin-side sheet and the non-skin-side sheet; An absorbent article having a longitudinal direction and a transverse direction perpendicular to the longitudinal direction, The absorbent core has a front region, a middle region, and a rear region in the longitudinal direction, the intermediate region has a central region located at a center portion in the lateral direction, and side regions located on both sides of the central region and having a basis weight lower than that of the central region, The central region has a basis weight of 500 g / m ２ The thickness is 3 mm or less, one or both of the front region and the rear region are easily deformable end regions having a basis weight and a density lower than those of the side regions, An absorbent article, wherein low basis weight lateral grooves extending in the lateral direction are formed in the central region and the side regions, and low basis weight lateral grooves extending in the lateral direction are not formed in the easily deformable end regions.

2. 2. The absorbent article of claim 1, wherein the density of the central region is equal to or greater than the density of the side regions.

3. The absorbent article according to claim 1 or 2, wherein low basis weight longitudinal grooves extending in the longitudinal direction are formed in the central region along a center line that divides the central region into two equal parts in the transverse direction.

4. The side region existing portion in which the side region exists and the end region existing portion in which the easily deformable end region exists have integrated grooves in which the skin side sheet is recessed together with the absorbent core, The absorbent article according to any one of claims 1 to 3, wherein the depth of the integrated groove in the side region existing portions is greater than the depth of the integrated groove in the end region existing portions.

5. The absorbent article according to claim 4, wherein the thickness of the side regions is equal to the thickness of the easily deformable end regions.

6. the side region existing portion in which the side region exists and the end region existing portion in which the easily deformable end region exists have integrated grooves in which the skin side sheet is recessed together with the absorbent core, The portion having the integrated groove in the side region existing portion has a higher KES compression amount (load 25 gf / cm) than the portion having the integrated groove in the end region existing portion. ２ The absorbent article according to any one of claims 1 to 5, wherein the thickness change when compressed to 100% is small.

7. The end region existing portion in which the easily deformable end region exists has an integrated groove in which the skin side sheet is recessed together with the absorbent core, The absorbent article according to any one of claims 1 to 6, wherein the KES compression amount of the portion having the integrated groove in the end region existing portion is within a range of ±20% of the KES compression amount of the portion other than the portion having the integrated groove.

8. At least the rear region of the front region and the rear region is the easily deformable end region, The absorbent article according to any one of claims 1 to 7, wherein, when the torsional torque values ​​measured by twisting the absorbent article around a vertical axis along the vertical direction are compared, the torsional torque value of a middle region existing portion in which the longitudinal middle region is present is greater than the torsional torque value of an end region existing portion in which the rear region is present.

9. At least the front region of the front region and the rear region is the easily deformable end region, 9. The absorbent article according to claim 1, wherein when the front region is divided into three regions, namely a front central region and a pair of front side regions located on either side of the front central region, by dividing the length of the front region in the lateral direction into thirds, the basis weight of each of the three regions is within ±8% of the average basis weight of the three regions.

10. At least the rear region of the front region and the rear region is the easily deformable end region, When the rear region is divided into three equal parts in the lateral direction into a rear central region and a pair of rear side regions located on both sides thereof, The absorbent article according to any one of claims 1 to 9, wherein the basis weight of the rear central region is higher than the basis weight of each of the pair of rear side regions and is at least 5% higher than the average basis weight of the pair of rear side regions.

11. The absorbent article according to any one of claims 1 to 10, wherein the ratio of the basis weight of the easily deformable end regions to the basis weight of the side regions is 30% or more and 75% or less.

12. The absorbent article according to any one of claims 1 to 11, wherein the ratio of the density of the easily deformable end regions to the density of the side regions is 30% or more and 75% or less.

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