JP2016150128A - Absorbent article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorbent article which is less likely to cause a body fluid to flow on a skin facing surface of a side sheet and to cause lateral leakage of the body fluid and hardly gives rubbing feeling and discomfort in wearing.SOLUTION: An absorbent article 10 includes a first body sheet 1B of an irregular structure in which projecting parts 13B and a recessed parts 14B are alternately arranged, and a first side sheet 1S of an irregular structure in which projecting parts 13S and recessed parts 14S are alternately arranged. A surface sheet 2 has a hollow structure formed by joining the surface sheet 2 with a second body sheet 21 at the recessed parts 14B of the first body sheet 1B through joining parts 15. A side sheet 5 has a hollow structure formed by joining the side sheet 5 with a second side sheet 51 at the recessed parts 14S of the first side sheet 1S through the joining parts 15. The projecting parts 13B of the first body sheet 1B engage with the recessed parts 14S of the first side sheet 1S, and the projecting parts 13S of the first side sheet 1S engage with the recessed strip parts 14B of the first body sheet 1B.SELECTED DRAWING: Figure 2

Description

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

  The applicant of the present invention first forms a water-repellent or non-liquid-permeable side leak-proof portion-forming sheet in which convex portions protruding to the skin facing surface side are dispersed in the vertical direction and the horizontal direction of the absorbent main body having the absorbent body. For example, Patent Literature 1 and Patent Literature 2 have been proposed as absorbent articles provided on both sides along the longitudinal direction. The side leak-proof part forming sheet with which the absorbent article of patent document 1 and patent document 2 is provided is the uneven | corrugated shaped sheet | seat which protruded to the skin opposing surface side and the inside of the convex part of a cavity was disperse | distributed to the vertical direction and the horizontal direction. . According to the absorbent articles described in Patent Document 1 and Patent Document 2, the air permeability of the side leak-proof portion is good, stuffiness and the like can be prevented, and the wearing feeling is excellent.

  As a technique different from this, Patent Document 3 describes an absorbent article including a surface sheet subjected to wave processing in which convex portions and concave portions extending along the vertical direction are alternately arranged in the horizontal direction. ing.

JP 2008-161303 A JP 2008-055108 A JP 2002-306533 A

  When the inventor uses a water-repellent or non-liquid-permeable flat side sheet on both sides along the longitudinal direction of the absorbent main body, if body fluid such as menstrual blood adheres to the skin facing surface of the side sheet, It was found that the body fluid tends to flow on the skin-facing surface of the side sheet and easily leads to leakage. In addition, in the configuration using a water-repellent or non-liquid-permeable flat side sheet on both sides along the longitudinal direction of the absorbent main body, the wearer feels rubbing or uncomfortable due to the movement of the thigh during wearing. End up. Furthermore, in the configuration using a water-repellent or non-liquid permeable flat side sheet on both sides along the longitudinal direction of the absorbent main body, when the body fluid absorbed in the absorbent body spreads laterally inside the absorbent body, It has been found that this may lead to side leakage of body fluids.

  However, since the side leak-proof portion forming sheet having the convex portion provided in the absorbent article described in Patent Literature 1 and Patent Literature 2 is water-repellent or non-liquid permeable, when body fluid adheres to the skin facing surface, Although it has a convex part, it is assumed that it flows on the skin facing surface and leads to leakage. In addition, these patent documents do not describe anything about using a sheet having a convex portion as the top sheet. In addition, these patent documents relate to a device that eliminates a feeling of rubbing or discomfort due to movement of the thigh while wearing, and a device that prevents lateral leakage of bodily fluid due to spreading of the bodily fluid absorbed in the absorbent body in the lateral direction. The absorbent article described in Patent Document 1 and Patent Document 2 has room for further improvement.

  Patent Document 3 does not describe anything about using a sheet having a convex portion as a side sheet. In addition, Patent Document 3 relates to a device that eliminates a feeling of rubbing or discomfort caused by movement of the thigh while wearing, and a device that prevents lateral leakage of bodily fluid due to spreading of the bodily fluid absorbed in the absorbent body in the lateral direction. Nothing is described.

  Therefore, the subject of this invention is providing the absorbent article which can eliminate the fault which the prior art mentioned above has.

  The present invention includes a liquid-permeable surface sheet that forms a skin facing surface, a back sheet that forms a non-skin facing surface, and an absorbent body interposed between the two sheets, and corresponds to the front-rear direction of the wearer. An absorbent body having a longitudinal direction and a transverse direction perpendicular to the longitudinal direction; and a side sheet disposed over the entire length of the absorbent body on the skin facing surface side of both side portions along the longitudinal direction of the absorbent body; The surface sheet is hydrophilic, and is disposed adjacent to the first sheet for the main body on the skin facing surface side and the non-skin facing surface side of the first sheet for the main body. Each of the side sheets is hydrophilic, and is arranged adjacent to the first sheet for the side on the non-skin facing side and the skin facing side of the first sheet for the side. A second sheet for the side, and the first sheet for the main body and the first sheet for the side. G is a non-woven fabric having a concavo-convex structure in which streaky ridges and ridges extending in the vertical direction are alternately arranged in the horizontal direction, and the top sheet is the first sheet for the main body and the second sheet for the main body. A sheet is joined to the first sheet for main body by the concave section, and a hollow structure is formed between the convex section of the first sheet for main body and the second sheet for main body. Each of the side sheets has a joint portion formed by joining the first side sheet and the second side sheet at the concave portion of the first side sheet. It has a hollow structure between the ridge part of the first sheet for use and the second sheet for the side, and when the absorbent article is worn, each side part of the absorbent body is used for the body. The ridges of the first sheet mesh with the ridges of the first side sheet, The convex portion of the first sheet for serial side, is to provide an absorbent article which is arranged to mate with the concave portion of the first sheet for the body.

  According to the present invention, even if a body fluid such as menstrual blood adheres to the skin facing surface of the side sheet, the body fluid is unlikely to flow on the skin facing surface of the side sheet, and is difficult to leak. Moreover, according to this invention, it is hard to give a rubbing feeling or discomfort during wearing. Further, according to the present invention, the body fluid absorbed by the absorbent body is difficult to spread in the lateral direction, and it is difficult for the body fluid to leak sideways.

FIG. 1 is a plan view showing the skin facing surface side (surface sheet side) of a sanitary napkin which is a preferred embodiment of the absorbent article of the present invention. 2A is a cross-sectional view schematically showing a cross section taken along line II in FIG. 1, and FIG. 2B is a cross-sectional view schematically showing a cross section taken along line II-II in FIG. FIG. 3 is an enlarged perspective view of a main part of the topsheet provided in the sanitary napkin shown in FIG. FIG. 4 is a plan view of the top sheet provided in the sanitary napkin shown in FIG. 1 as viewed from the skin facing surface side of the sanitary napkin. FIG. 5 is an enlarged perspective view of a main part of a side seat provided in the sanitary napkin shown in FIG. 1. FIG. 6 is a plan view of the side sheet provided in the sanitary napkin shown in FIG. 1 as viewed from the non-skin facing surface side of the sanitary napkin. FIG. 7 is an enlarged schematic cross-sectional view of the main part of the first main body sheet constituting the top sheet shown in FIG. FIG. 8 is an enlarged schematic cross-sectional view of the main part of the first side sheet constituting the side sheet shown in FIG. FIG. 9 is a diagram for explaining a state in which the constituent fibers constituting the first main body sheet shown in FIG. 7 or the first side sheet shown in FIG. 8 are fixed at the heat-sealing portion. FIG. 10 is a schematic view showing a manufacturing apparatus suitably used for manufacturing the first main body sheet shown in FIG. 7 or the first side sheet shown in FIG. 11 is a cross-sectional view taken along line IX-IX shown in FIG. FIG. 12A to FIG. 12C are explanatory views for explaining a state in which a plurality of small diameter portions and large diameter portions are formed in one constituent fiber between adjacent fused portions. FIG. 13 is an enlarged cross-sectional view of a main part of the sanitary napkin shown in FIG. 1 in a state where the top sheet and the side sheet overlap each other.

  Hereinafter, the absorbent article of the present invention will be described with reference to the drawings based on a sanitary napkin (hereinafter also referred to as a napkin) which is a preferred embodiment thereof. As shown in FIGS. 1 and 2, the napkin 10 of the present embodiment includes a liquid-permeable surface sheet 2 that forms a skin facing surface, a back sheet 3 that forms a non-skin facing surface, and both of these sheets 2 and 3. An absorbent main body 10B having an absorbent body 4 interposed therebetween and having a longitudinal direction X corresponding to the longitudinal direction of the wearer and a lateral direction Y orthogonal to the longitudinal direction X, and the longitudinal direction X of the absorbent main body 10B The side sheet | seat 5 distribute | arranged over the full length of the absorptive main body 10B is provided in the skin opposing surface (skin opposing surface of the surface sheet 2) side of the both sides which follow.

  In the present specification, the skin facing surface is a surface facing the wearer's skin when the absorbent article is worn in the absorbent article or its constituent member (for example, the absorbent main body 10B), and is a non-skin facing surface. Is the surface of the absorbent article or its component that is directed to the side opposite to the skin side (clothing side) when the absorbent article is worn. The longitudinal direction X coincides with the longitudinal direction of the absorbent article (absorbent body 10B), and the lateral direction Y coincides with the width direction (direction orthogonal to the longitudinal direction) of the absorbent article (absorbent body 10B). To do.

  The absorbent main body 10B of the napkin 10 has an excretory part facing part B disposed opposite to a wearer's excretory part (such as the vaginal opening) at the time of wearing, and closer to the wearer's abdomen (front side) than the excretory part facing part B And a rear part C arranged closer to the wearer's back side (rear side) than the excretory part facing part B. The absorptive main body 10B is divided in the order of the front part A, the excretory part opposing part B, and the rear part C in the vertical direction X.

  In this embodiment, as shown in FIG.1 and FIG.2 (a), in addition to the absorptive main body 10B, the napkin 10 is each each the both sides along the vertical direction X of the excretion part opposing part B in the absorptive main body 10B. A pair of wing portions 10W, 10W extending outward in the lateral direction Y from the right side.

  In the absorbent article of the present invention, when the excretory part facing part B has the wing part 10W like the napkin 10 of the present embodiment, the longitudinal direction of the absorbent article (the longitudinal direction of the absorbent article, FIG. (The X direction in the middle) is a region having a wing portion 10W (a region sandwiched between a root along the vertical direction X of one wing portion 10W and a root along the vertical direction X of the other wing portion 10W). The excretion part opposing part in the absorbent article which does not have a wing part is the transverse direction (width direction of an absorbent article, in the figure) generated when the absorbent article is folded into a tri-fold individual form. The two folding curves (not shown) crossing in the Y direction) are areas surrounded by the first folding curve and the second folding curve counted from the front end in the longitudinal direction X of the absorbent article.

  Moreover, in this embodiment, as shown in FIG.1 and FIG.2, in addition to a pair of wing parts 10W and 10W, the napkin 10 is further each of the both sides along the vertical direction X of the back part C in the absorptive main body 10B. A pair of rear flap portions 10F, 10F extending outward in the lateral direction Y from the rear side. Such a napkin 10 having the rear flap portion 10F is suitable for long-time use such as at bedtime and is particularly useful as a sanitary napkin for nighttime use.

  In the napkin 10, the topsheet 2 covers the entire skin facing surface of the absorbent body 4 as shown in FIGS. 2 (a) and 2 (b), and both side edges along the longitudinal direction X of the absorbent body 4. To the outside in the lateral direction Y. On the other hand, the back sheet 3 covers the entire area of the non-skin facing surface of the absorbent body 4 and further extends outward in the lateral direction Y from both side edges along the longitudinal direction X of the absorbent body 4 to form the absorbent main body 10B. A side flap portion 10 </ b> S is formed together with the side seat 5 disposed on the side portion along the vertical direction X. The back sheet 3 and the side sheet 5 are joined to each other by known joining means such as an adhesive, a heat seal, and an ultrasonic seal at the extended portions from both side edges along the longitudinal direction X of the absorber 4. The top sheet 2 and the back sheet 3 may be bonded to the absorber 4 with an adhesive.

  In the napkin 10, the absorbent body 4 is formed on the excretory part-facing part B, thicker than the peripheral part and on the topsheet 2 side (napkin 10), as shown in FIGS. 1, 2 (a) and 2 (b). The middle-high portion 42 is raised on the skin facing surface side. Preferably, the absorbent body 4 includes a lower layer absorber 40 extending from the front part A through the excretory part facing part B to the rear part C, and is narrower than the lower layer absorbent body 40 and in the excretion part facing part B. An upper layer absorber 41 disposed on the skin facing surface side of the central portion of the absorbent body 40 in the lateral direction Y, and a laminate of the upper layer absorber 41 and the lower layer absorber 40 forms a middle-high portion 42. ing. The upper layer absorber 41 is arranged on the lower layer absorber 40 with its longitudinal direction X coinciding with the longitudinal direction X of the lower layer absorber 40. The lower layer absorber 40 and the upper layer absorber 41 may be joined by an adhesive.

  In the napkin 10, the side seat 5 is arranged over the entire length in the longitudinal direction X of the absorbent main body 10B so as to overlap the left and right side portions along the longitudinal direction X of the absorbent body 4, as shown in FIGS. Has been. In the napkin 10, the pair of side sheets 5 and 5, as shown in FIG. 1, each have a linear first joining line 61 positioned in the excretory part facing part B, and a longitudinal direction X of the first joining line 61. Are joined to the topsheet 2 by linear second joining lines 62 located in the front and rear (front part A and rear part C). The first joining line 61 has a curved shape that protrudes outward in the lateral direction Y in plan view, and the second joining line 62 has a linear shape (zigzag line shape) that extends in the longitudinal direction in plan view. ). As described above, when the side sheet 5 is bonded to the surface sheet 2 by the first bonding line 61 and the second bonding line 62 and is fixed to the skin facing surface of the absorbent main body 10B, FIG. As shown in FIG. 2B, a space P defined by the side sheet 5 and the top sheet 2 is formed inward in the lateral direction Y from the first joint line 61 and the second joint line 62. The Since the space P is opened toward the center in the lateral direction Y of the absorbent main body 10B, body fluid such as menstrual blood flowing outward from the center in the lateral direction Y is accommodated in the space P. As a result, leakage of body fluid can be effectively prevented.

  In the napkin 10, as shown in FIG. 1, the side flap portion 10S greatly protrudes outward in the lateral direction Y at the excretory portion facing portion B, and thereby the left and right sides along the longitudinal direction X of the absorbent main body 10B. A pair of wing portions 10W and 10W are extended on both sides. Further, in the napkin 10, as shown in FIG. 1, the side flap portion 10S projects greatly outward in the lateral direction Y at the rear portion C, whereby the left and right sides along the longitudinal direction X of the absorbent main body 10B. A pair of rear flap portions 10F, 10F are extended on both sides. Further, as shown in FIG. 1, the top sheet 2 and the back sheet 3 extend outward in the longitudinal direction X from the front end and the rear end in the longitudinal direction X of the absorbent body 4. The end seal portion is formed by bonding to each other by a known bonding means such as an agent, heat sealing, ultrasonic sealing or the like.

  The wing portion 10W is used by being folded back to the non-skin facing surface side of the crotch portion of clothes such as shorts. In the napkin 10, as shown in FIG. 1, the wing portion 10W has a substantially trapezoidal shape in which the lower base (side longer than the upper base) is located on the side portion side along the longitudinal direction X of the absorbent main body 10B. It has a shape. As shown in FIG. 2A, a wing portion adhesive portion 71 for fixing the wing portion 10W (napkin 10) to clothing (not shown) such as shorts is formed on the non-skin facing surface of the wing portion 10W. ing. The wing portion adhesive portion 71 allows the wing portion 10W folded back to the non-skin facing surface (outer surface) side of the crotch portion of the clothing to be adhesively fixed to the crotch portion during use. Moreover, as shown in FIG. 2A and FIG. 2B, the main body adhesive portion 72 (for fixing the absorbent main body 10B to clothes such as shorts also on the non-skin facing surface of the absorbent main body 10B. A misalignment stopper) is formed.

  The rear flap portion 10F is used by being spread over the heel portion on the skin facing surface side of clothes such as shorts. In the napkin 10, the rear flap portion 10F is arranged over the entire length in the longitudinal direction X of the rear region C in a plan view as shown in FIG. 1, and the width in the lateral direction Y gradually increases toward the rear. It has a shape. As shown in FIG. 2 (b), on the non-skin facing surface of the rear flap portion 10F, the rear flap portion adhesive portion 73 that fixes the rear flap portion 10F (napkin 10) to clothing (not shown) such as shorts. Is formed. By this rear flap portion adhesive portion 73, the rear flap portion 10F can be adhesively fixed to the buttock portion on the skin facing surface side of the clothes at the time of use.

  In the napkin 10, as shown in FIG. 1, FIG. 2 (a) and FIG. 2 (b), the surface sheet 2 and the absorbent body 4 are provided on the skin facing surface of the absorbent main body 10B (skin facing surface of the surface sheet 2). A linear squeezing groove 8 that is integrally recessed toward the back sheet 3 side is formed. The “linear shape” in the linear compressed groove 8 is not limited to a straight line in the plan view, but includes a curved line, and each line may be a continuous line or a broken line. For example, the linear squeezing groove 8 may be composed of a row formed by a number of discontinuous point embosses. The linear pressing groove 8 includes a first horizontal pressing groove 81 extending in the horizontal direction Y and a vertical pressing groove 82 extending in the vertical direction X on both sides of the excretory part-facing portion B in the front part A and the rear part C, respectively. Have. In the napkin 10, the first lateral pressing grooves 81 of the front part A and the rear part C have a curved shape that protrudes outward in the vertical direction X, and each vertical pressing groove 82 is a straight line that extends parallel to the vertical direction X. Is. In the napkin 10, the first lateral pressing groove 81 in the front part A, one vertical pressing groove 82, the first horizontal pressing groove 81 in the rear part C, and the other vertical pressing groove 82 are connected to form a ring-shaped circumferential groove. Forming.

  Moreover, in the napkin 10, as shown in FIG. 1, the linear pressing groove 8 is the 2nd horizontal pressing groove extended in the horizontal direction Y in the longitudinal direction X inner side rather than the 1st horizontal pressing groove 81 in the front part A. 83. In the napkin 10, the second lateral pressing groove 83 has a curved shape that is convex outward in the vertical direction X. In addition, although the 2nd horizontal pressing groove 83 of the napkin 10 is connected with a pair of vertical pressing grooves 82 and 82 as shown in FIG. 1, it does not need to be connected. Moreover, in the napkin 10, as shown in FIG. 1, the linear pressing groove 8 is the 3rd horizontal pressing groove extended in the horizontal direction Y in the longitudinal direction X inner side rather than the 1st horizontal pressing groove 81 in the back part C. 84. In the napkin 10, the third lateral pressing groove 84 is formed in a tapered shape toward the rear end in the vertical direction X. In addition, although the 3rd horizontal pressing groove 84 of the napkin 10 is connected with a pair of vertical pressing grooves 82 and 82 as shown in FIG. 1, it does not need to be connected. The linear pressing groove 8 formed in this way is formed by the second horizontal pressing groove 83 in the front portion A, one vertical pressing groove 82, the third horizontal pressing groove 84 in the rear portion C, and the other vertical pressing groove 82. The absorber 4 surrounds the middle and high portions 42, and further outwards of the first horizontal pressing groove 81 in the front portion A, one vertical pressing groove 82, the first horizontal pressing groove 81 in the rear portion C, and the other vertical pressing groove 82. Since it surrounds with the pressing groove 82, the spreading | diffusion of the bodily fluid to the plane direction of the absorber 4 can be suppressed, and a liquid leak from the circumference | surroundings of the napkin 10 can be prevented effectively.

  The surface sheet 2 of the napkin 10 will be described in detail. The surface sheet 2 is hydrophilic. As shown in FIGS. 2 to 4, the first sheet 1B for the main body on the skin-facing surface side and the first sheet for the main body It has the 2nd sheet | seat 21 for main bodies arrange | positioned adjacent to the non-skin opposing surface side of 1B. As shown in FIG. 2A, FIG. 2B, and FIG. 3, the first sheet for main body 1B has a ridge shape that continuously extends in the vertical direction X. The part 13B and the concave line part 14B are comprised from the nonwoven fabric of the uneven structure by which the horizontal direction Y was alternately arrange | positioned. In the napkin 10, the second main body sheet 21 is formed of a non-woven fabric having a flat structure. As shown in FIGS. 3 to 4, the surface sheet 2 is formed by joining the first main body sheet 1 </ b> B and the second main body sheet 21 at the concave strip portion 14 </ b> B of the first main body sheet 1 </ b> B. 15, and has a hollow structure between the ridge 13 </ b> B of the first main body sheet 1 </ b> B and the second main body sheet 21.

  The joint portion 15 between the main body first sheet 1B and the main body second sheet 21 may be formed so as to continuously extend in the longitudinal direction X along the concave strip portion 14B of the main body first sheet 1B. 1 and 4, the napkin 10 is intermittently formed in the longitudinal direction X along the concave strip portion 14 </ b> B of the first main body sheet 1 </ b> B, and the joining portion 15 adjacent in the lateral direction Y. , 15 are arranged on a virtual straight line (not shown) extending in parallel to the horizontal direction Y. Preferably, the plurality of joints 15 are arranged on a vertical imaginary straight line (not shown) extending in parallel to the vertical direction X at equal intervals in the vertical direction X, and are also equally spaced in the horizontal direction Y. Are arranged on a horizontal imaginary straight line (not shown) extending in parallel to the horizontal direction Y. Thus, in the napkin 10, the first main body sheet 1 </ b> B and the second main body sheet 21 are partially bonded by the plurality of bonding portions 15 dispersed in both the vertical direction X and the horizontal direction Y. . The joining portion 15 can be formed by applying an adhesive, heat sealing or ultrasonic sealing, and the napkin 10 is formed by heat sealing or ultrasonic sealing.

When the bonding portion 15 is formed by applying an adhesive, the adhesive is applied using a known means, for example, a slot coat gun, a spiral spray gun, a spray gun, or a dot gun. As the adhesive to be applied, for example, a hot melt adhesive is preferably used. The application amount of the hot melt adhesive is preferably 3 g / m ² or more and 10 g / m ² or less.

  FIG. 3 is a perspective view of the first main body sheet 1B constituting the top sheet 2 in the napkin 10 of the present embodiment. As shown in FIG. 3, the first sheet for main body 1B includes a plurality of protruding ridges 13B in which the cross-sectional shapes of both the front and back surfaces are convex upward in the thickness direction, and adjacent protruding ridges 13B and 13B. And a concave strip portion 14B positioned between the two. The concave strip portion 14B has a concave shape in which the cross-sectional shape of both the front and back surfaces is upward in the thickness direction of the first main body sheet 1B. In other words, the concave stripe portion 14B has a convex shape toward the lower side in the thickness direction of the main body first sheet 1B. Each of the plurality of ridge portions 13B has a hook shape extending continuously in the longitudinal direction X of the first main body sheet 1B, and the plurality of concave ridge portions 14B are also formed in the vertical direction of the first main body sheet 1B. A groove shape extending continuously in the direction X is formed. The ridges 13B and the ridges 14B are parallel to each other and are alternately arranged in the horizontal direction Y orthogonal to the vertical direction X.

  As will be described later, the first sheet for main body 1B is manufactured by performing uneven processing on the fiber sheet 1a using a pair of uneven rollers 401 and 402 that mesh with each other. The longitudinal direction X of the main body first sheet 1B described above is the same as the machine direction (MD, flow direction) when the fiber sheet 1a (see FIG. 10) is processed to produce the main body first sheet 1B. The transverse direction Y orthogonal to the longitudinal direction X of the first main body sheet 1B described above is the same direction as the orthogonal direction (CD, roll axis direction) orthogonal to the machine direction (MD, flow direction). .

  In the napkin 10, as shown in FIGS. 2 (a) and 2 (b), the first sheet 1B for a main body having a concavo-convex structure including the ridges 13B and the ridges 14B is the center in the lateral direction Y of the napkin 10. Not only the area but also at least the area overlapping each side seat 5 is arranged. On the other hand, as shown in FIG. 2, the second main body sheet 21 having a flat structure covers the entire skin-facing surface of the absorbent body 4 as shown in FIG. 2, and further, both side edges along the longitudinal direction X of the absorbent body 4. To the outside in the lateral direction Y. As described above, the first main body sheet 1 </ b> B only needs to be arranged up to the region overlapping each side sheet 5 in the lateral direction Y, and may not be arranged in the same width as the second main body sheet 21. . In the napkin 10, the first main body sheet 1 </ b> B is arranged in the longitudinal direction X with the same length as the second main body sheet 21, and extends outward from both edges of the absorbent body 4 in the longitudinal direction X. It is extended.

  When describing each side sheet 5 of the napkin 10 in detail, the side sheet 5 is hydrophilic, and as shown in FIGS. 2, 5, and 6, the side first sheet 1 </ b> S on the non-skin facing surface side, It has the 2nd sheet | seat 51 for sides arrange | positioned adjacent to the skin opposing surface side of the 1st sheet | seat 1S for sides. As shown in FIGS. 2 (a), 2 (b), and 5, the first sheet 1S for side has a ridge portion 13S and a ridge portion 14S each having a hook shape extending in the longitudinal direction X in the horizontal direction. It is comprised from the nonwoven fabric of the uneven structure arranged alternately by Y. In the napkin 10, the second side sheet 51 is composed of a non-woven fabric having a flat structure. As shown in FIGS. 5 to 6, the side sheet 5 is formed by joining the first side sheet 1 </ b> S and the second side sheet 51 at the concave portion 14 </ b> S of the first side sheet 1 </ b> S. 15 and has a hollow structure between the convex strip portion 13S of the first side sheet 1S and the second side sheet 51.

  The joint portion 15 between the first side sheet 1S and the second side sheet 51 may be formed so as to continuously extend in the longitudinal direction X along the concave portion 14S of the first side sheet 1S. 1 and 6, the napkin 10 is intermittently formed in the vertical direction X along the concave strip portion 14 </ b> S of the first side sheet 1 </ b> S. 15 and 15 are arranged on a virtual straight line (not shown) extending parallel to the horizontal direction Y. Preferably, the plurality of joints 15 are arranged on a vertical imaginary straight line (not shown) extending in parallel to the vertical direction X at equal intervals in the vertical direction X, and are also equally spaced in the horizontal direction Y. Are arranged on a horizontal imaginary straight line (not shown) extending in parallel to the horizontal direction Y. As described above, in the napkin 10, the first side sheet 1 </ b> S and the second side sheet 51 are partially joined by the plurality of joint portions 15 dispersed in both the vertical direction X and the horizontal direction Y. . The joining portion 15 can be formed by applying an adhesive, heat sealing or ultrasonic sealing, and the napkin 10 is formed by heat sealing or ultrasonic sealing. In addition, when the joining part 15 is formed by applying an adhesive, it can be formed by the same method as the joining part 15 between the first main body sheet 1B and the second main body sheet 21 described above.

  FIG. 5 shows a perspective view of the first side sheet 1 </ b> S constituting the side seat 5 in the napkin 10 of the present embodiment. As shown in FIG. 5, the first sheet for side 1 </ b> S has a plurality of ridge portions 13 </ b> S in which the cross-sectional shapes of both the front and back surfaces are convex downward in the thickness direction (on the surface sheet 2 side), and adjacent protrusions. It has the concave line part 14S located between the line parts 13S and 13S. The concave stripe portion 14S has a concave shape in which the cross-sectional shapes of both the front and back surfaces are both downward in the thickness direction of the first side sheet 1S (on the surface sheet 2 side). In other words, the concave strip portion 14S has a convex shape toward the upper side in the thickness direction of the first side sheet 1S (on the second side sheet 51 side). Each of the plurality of ridges 13S extends continuously in the longitudinal direction X of the first side sheet 1S, and each of the plurality of ridges 14S also continues in the longitudinal direction X of the first side sheet 1S. It has a groove shape that extends. The ridges 13 </ b> S and the ridges 14 </ b> S are parallel to each other and are alternately arranged in the lateral direction Y orthogonal to the longitudinal direction X.

  The first side sheet 1S is subjected to a concavo-convex process using a pair of concavo-convex rolls 401 and 402 meshing with each other, as will be described later, in the same manner as the first main body sheet 1B constituting the top sheet 2. Is manufactured. The longitudinal direction X of the first side sheet 1S described above is the same as the machine direction (MD, flow direction) when the side sheet 1a (see FIG. 10) is processed to produce the side first sheet 1S. The lateral direction Y orthogonal to the longitudinal direction X of the first side sheet 1S described above is the same direction as the orthogonal direction (CD, roll axis direction) orthogonal to the machine direction (MD, flow direction). .

  In the napkin 10, as shown in FIGS. 2 (a) and 2 (b), the first side sheet 1S having a concavo-convex structure composed of the ridges 13S and the ridges 14S is at least the longitudinal direction X of the surface sheet 2. Is disposed in a region overlapping with the first main body sheet 1 </ b> B constituting the top sheet 2. On the other hand, as shown in FIG. 2, the side second sheet 51 having a flat structure covers a side portion along the longitudinal direction X of the absorbent body 4 and further along the longitudinal direction X of the absorbent body 4 as shown in FIG. 2. It extends outward in the lateral direction Y from the side edge. As described above, in the lateral direction Y, the first side sheet 1S only needs to be arranged in a region overlapping the first main body sheet 1B constituting the top sheet 2, and has the same width as the second side sheet 51. It does not have to be arranged. In the napkin 10, the first side sheet 1 </ b> S is arranged in the longitudinal direction X with the same length as the second side sheet 51, and extends outward from both end edges of the absorbent body 4 in the longitudinal direction X. It is extended.

  As described above, the surface sheet 2 of the napkin 10 has the ridge-shaped convex strip portion 13B and the concave strip portion 14B extending in the longitudinal direction X, as shown in FIGS. 2 (a), 2 (b), and FIG. It has the 1st sheet | seat 1B for main bodies of the uneven structure arranged alternately by the horizontal direction Y. As shown in FIG. Further, as shown in FIGS. 2A, 2B and 5, the side sheet 5 of the napkin 10 has a ridge-shaped convex strip portion 13 </ b> S and a concave strip portion 14 </ b> S extending in the vertical direction X. The first sheet for main body 1B having a concavo-convex structure arranged alternately is provided. Therefore, in the napkin 10, as shown in FIG. 2 (a) and FIG. 2 (b), the ridges of the main body first sheet 1B are respectively provided on both side portions along the longitudinal direction X of the absorbent main body 10B when worn. The portion 13B meshes with the concave strip portion 14S of the first side sheet 1S, and the convex strip portion 13S of the first side sheet 1S is arranged to mesh with the concave strip portion 14S of the first main body sheet 1B. become. Thereby, since the 1st sheet 1B for main bodies and the 1st sheet 1S for sides become difficult to move, the feeling of rubbing and the sense of incongruity which are felt by the movement of the thigh during wearing can be eliminated. Further, by engaging the top sheet 2 with the hollow structure and the side sheet 5 with the hollow structure, the return of the body fluid absorbed by the absorbent body 4 to the skin facing surface side is suppressed, and there is an effect of preventing leakage.

  FIG. 7 schematically shows a cross section in the thickness direction of the first main body sheet 1B constituting the top sheet 2 shown in FIG. FIG. 8 schematically shows a cross section in the thickness direction of the first side sheet 1S constituting the side sheet 5 shown in FIG. FIG. 9 is an enlarged schematic view of the constituent fibers 11 of the first main body sheet 1B shown in FIG. 7 and the constituent fibers 11 of the first side sheet 1S shown in FIG. As shown in FIG. 9, the first main body sheet 1 </ b> B and the first side sheet 1 </ b> S are non-woven fabrics provided with a plurality of fusion portions 12 formed by thermally fusing the intersections of the constituent fibers 11.

  In the napkin 10, the first main body sheet 1B has a top region 13a, a bottom region 13b, and these parts when the first main body sheet 1B is viewed in a cross-section along the thickness direction Z as shown in FIGS. It is comprised from the side part area 13c located in between. The top of the ridge 13B is formed from the top region 13a, and the bottom of the ridge 14B is formed from the bottom region 13b. The top region 13a, the bottom region 13b, and the side region 13c extend continuously in the longitudinal direction X of the first main body sheet 1B. When the top region 13a, the bottom region 13b, and the side region 13c are cross-sectional views of the first main body sheet 1B along the thickness direction Z, the thickness in the Z direction of the first main body sheet 1B is divided into three equal parts, A region above the thickness direction Z is distinguished as a top region 13a, a central region as a side region 13c, and a region below as a bottom region 13b.

  In the napkin 10, the first side sheet 1 </ b> S is a first main body sheet that constitutes the top sheet 2 when the side first sheet 1 </ b> S is viewed in cross-section along the thickness direction Z as shown in FIGS. 5 and 8. Like 1B, it is comprised from the top part area | region 13a, the bottom part area | region 13b, and the side part area | region 13c located among these. The top of the ridge 13S is formed from the top region 13a, and the bottom of the ridge 14S is formed from the bottom region 13b. The top region 13a, the bottom region 13b, and the side region 13c extend continuously in the longitudinal direction X of the first side sheet 1S. When the top region 13a, the bottom region 13b, and the side region 13c are cross-sectional views of the first side sheet 1S along the thickness direction Z, the thickness in the Z direction of the first side sheet 1S is divided into three equal parts, The part below the thickness direction Z (on the top sheet 2 side) is distinguished as the top area 13a, the central part is identified as the side area 13c, and the area above (on the side second sheet 51) is distinguished as the bottom area 13b.

  In the napkin 10, the first main body sheet 1 </ b> B and the first side sheet 1 </ b> S are cross-sectionally viewed as shown in FIGS. 7 and 8 in the side area 13 c between the top area 13 a and the bottom area 13 b. The fiber density is formed lower than the fiber density of the top region 13a and the fiber density of the bottom region 13b. Here, the fiber density is the number of fibers per unit area in the cross section of the first main body sheet 1B or the first side sheet 1S. Therefore, the side region 13c is a sparse region because the number of fibers is small and the inter-fiber distance is large compared to the top region 13a and the bottom region 13b. Due to the fact that the top area 13a has a higher fiber density than the side area 13c, the top area 13a having a high fiber density is supported when the first sheet for main body 1B and the first sheet for side 1S are engaged with each other. Therefore, the shape is difficult to deform. Therefore, since the hollow structure of the surface sheet 2 or the hollow structure of the side sheet 5 can be maintained, it is difficult to inhibit the feeling of wearing and the anti-moisture performance. Moreover, since the fiber density of the side region 13c is low, the body fluid absorbed by the absorbent body 4 is less likely to move from the bottom region 13b of the main body first sheet 1B toward the top region 13a. Hard to return.

The ratio (D _13c / D _13a , D _13c / D _13a ) of the fiber density (D _13c ) of the side region 13c to the fiber density (D _13a ) in the top region 13a or the fiber density (D _13b ) in the bottom region 13b ) Is preferably 0.15 or more and 0.9 or less, more preferably 0.2 or more and 0.8 or less. Specifically, the specific value of the fiber density of the first sheet for main body 1B or the first sheet for side 1S is such that the fiber density (D _13a ) in the top region 13a is preferably 90 / mm ² or more and 200. / Mm ² or less, more preferably 100 / mm ² or more and 180 / mm ² or less. Also, the fiber density _{(D 13b)} at the bottom area 13b is preferably 80 present / mm ² or more 200 present / mm ² or less, more preferably 90 present / mm ² or more 180 lines / mm ² or less. Also, the fiber density _{(D 13c)} of the side region 13c, preferably 30 present / mm ² or more eighty / mm ² or less, more preferably 40 present / mm ² or more 70 yarns / mm ² or less. The method for measuring the fiber density is as follows.

[Measuring method of fiber density in top region 13a, bottom region 13b and side region 13c]
The top sheet 2 including the main body first sheet 1 </ b> B and the main body second sheet 21 is cut along the thickness direction Z using a feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). Regarding the fiber density in the top region 13a, the top region 13a, which is the upper part when the thickness of the cut surface of the first main body sheet 1B constituting the top sheet 2 is equally divided in the Z direction, The number of cross-sections of fibers cut by the cut surface per fixed area (about 0.5 mm ² ) by magnifying observation (adjusted to a magnification capable of measuring about 30 to 60 fiber cross-sections; 150 to 500 times) Count. Next, it converts into the number of cross sections of the fiber per 1 mm < ² >, and makes this the fiber density in the top region 13a. The measurement is performed at three locations, and the average is the fiber density of the sample. Similarly, the fiber density in the bottom region 13b is obtained by measuring the lower part when the thickness of the cut surface of the first main body sheet 1B constituting the top sheet 2 is equally divided in the Z direction. Similarly, the fiber density of the side region 13c is obtained by measuring a central portion when the thickness of the cut surface of the first main body sheet 1B constituting the top sheet 2 is equally divided in the Z direction. Note that JCM-5100 (trade name) manufactured by JEOL Ltd. is used as the scanning electron microscope. Similarly, for the first side sheet 1S, the side sheet 5 including the first side sheet 1S and the second side sheet 51 is cut along the thickness direction Z, and the fiber density is measured.

  In the napkin 10, the constituent fibers 11 of the first main body sheet 1B or the first side sheet 1S include high elongation fibers. Here, the high elongation fiber included in the constituent fiber 11 is not only a fiber having a high elongation at the raw material fiber stage, but also at the stage of the manufactured first sheet for main body 1B or side first sheet 1S. It means a fiber with high elongation. As the “high elongation fiber”, excluding stretchable fibers that have elasticity (elastomer) and expand and contract, for example, as described in paragraph [0033] of JP 2010-168715, melt spinning is performed at a low speed to form a composite After obtaining the fiber, heat-extensible fiber obtained by performing heat treatment and / or crimping treatment without performing a stretching treatment, the crystal state of the resin being changed by heating, and extending the length, or polypropylene, Fibers manufactured under relatively low spinning speed using a resin such as polyethylene, or fibers manufactured by dry blending and spinning polyethylene with a polyethylene-polypropylene copolymer or polypropylene with low crystallinity. Etc. Among these fibers, the high elongation fiber is preferably a core-sheath type composite fiber having heat-fusibility. The core-sheath type composite fiber may be a concentric core-sheath type, an eccentric core-sheath type, a side-by-side type, or a deformed type, but is preferably a concentric core-sheath type. From the viewpoint of producing the first sheet 1B for the main body or the first sheet 1S for the side that is flexible and has a good touch regardless of the form of the fibers, the fineness of the high elongation fibers is the raw material. In this stage, 1.0 dtex or more and 10.0 dtex or less is preferable, and 2.0 dtex or more and 8.0 dtex or less is more preferable.

  The constituent fibers 11 of the first main body sheet 1B or the first side sheet 1S may include other fibers in addition to the high elongation fibers, but may include only the high elongation fibers. Preferably it is. Other fibers include, for example, a non-heat-extensible core-sheath type heat-fusible composite fiber containing two components having different melting points, or a fiber that does not inherently have heat-fusibility ( Examples thereof include natural fibers such as cotton and pulp, rayon and acetate fibers). When the first sheet for main body 1B or the first sheet for side 1S includes other fibers in addition to the high elongation fiber, the first sheet for main body 1B or the first sheet for side 1S is highly stretched. The ratio of the fiber is preferably 50% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less.

  The heat-stretchable composite fiber that is a high-stretch fiber is a composite fiber that has been subjected to an unstretched or weakly stretched treatment at the raw material stage. For example, the first resin component constituting the core portion and the sheath portion And a second resin component including a polyethylene resin, and the first resin component has a higher melting point than the second resin component. A 1st resin component is a component which expresses the heat | fever extensibility of this fiber, and a 2nd resin component is a component which expresses heat-fusibility. The melting points of the first resin component and the second resin component were determined by thermal analysis of a finely cut fiber sample (sample weight 2 mg) using a differential scanning calorimeter (DSC6200 manufactured by Seiko Instruments Inc.) at a heating rate of 10 ° C./min. The melting peak temperature of each resin is measured and defined by the melting peak temperature. When the melting point of the second resin component cannot be clearly measured by this method, the resin is defined as “resin having no melting point”. In this case, the temperature at which the second resin component is fused to such an extent that the strength of the fusion point of the fiber can be measured is used as the temperature at which the molecular flow of the second resin component begins, and this is used instead of the melting point.

As above-mentioned as a 2nd resin component which comprises a sheath part, the polyethylene resin is included. Examples of the polyethylene resin include low density polyethylene (LDPE), high density polyethylene (HDPE), and linear low density polyethylene (LLDPE). In particular, a high density polyethylene having a density of 0.935 g / cm ³ or more and 0.965 g / cm ³ or less is preferable. The second resin component constituting the sheath is preferably a polyethylene resin alone, but other resins can also be blended. Other resins to be blended include polypropylene resin, ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl alcohol copolymer (EVOH), and the like. However, as for the 2nd resin component which comprises a sheath part, it is preferable that 50 mass% or more in the resin component of a sheath part is 70 to 100 mass% especially polyethylene resin. The polyethylene resin preferably has a crystallite size of 10 nm or more and 20 nm or less, and more preferably 11.5 nm or more and 18 nm or less.

  As a 1st resin component which comprises a core part, the resin component whose melting | fusing point is higher than the polyethylene resin which is a constituent resin of a sheath part can be especially used without a restriction | limiting. Examples of the resin component constituting the core include polyolefin resins such as polypropylene (PP) (excluding polyethylene resin), polyester resins such as polyethylene terephthalate (PET), and polybutylene terephthalate (PBT). Furthermore, polyamide-based polymers, copolymers having two or more resin components, and the like can also be used. A plurality of types of resins can be blended and used. In this case, the melting point of the core is the melting point of the resin having the highest melting point. Since the manufacture of the first sheet for main body 1B or the first sheet for side 1S is facilitated, the difference between the melting point of the first resin component constituting the core portion and the melting point of the second resin component constituting the sheath portion ( The former-the latter) is preferably 20 ° C. or higher, and preferably 150 ° C. or lower.

  The preferred orientation index of the first resin component in the heat-stretchable composite fiber, which is a high elongation fiber, is naturally different depending on the resin used. For example, when the first resin component is a polypropylene resin, the orientation index is 60% or less. Is preferable, more preferably 40% or less, and still more preferably 25% or less. When the first resin component is polyester, the orientation index is preferably 25% or less, more preferably 20% or less, and still more preferably 10% or less. On the other hand, the second resin component preferably has an orientation index of 5% or more, more preferably 15% or more, and further preferably 30% or more. The orientation index is an index of the degree of orientation of the polymer chain of the resin constituting the fiber. And when the orientation index of a 1st resin component and a 2nd resin component is each said value, a heat | fever extensible composite fiber comes to expand | extend by heating.

  The orientation index of the first resin component and the second resin component is determined by the method described in paragraphs [0027] to [0029] of JP2010-168715A. Moreover, the method in which each resin component in the thermally stretchable conjugate fiber achieves the orientation index as described above is described in paragraphs [0033] to [0036] of JP-A No. 2010-168715.

  Further, the elongation of the high elongation fiber is preferably 100% or more and 800% or less, more preferably 200% or more and 500% or less, and further preferably 250% or more and 400% or less at the raw material stage. By using the high elongation fiber having the elongation in this range, the fiber is successfully stretched in the stretching apparatus, and the changing point from the small diameter portion to the large diameter portion described above is adjacent to the fusion portion. , The touch becomes good.

  The elongation of the high elongation fiber conforms to JIS L-1015, and is measured under the conditions of measurement environment temperature and humidity 20 ± 2 ° C., 65 ± 2% RH, tensile tester gripping distance 20 mm, and tensile speed 20 mm / min. The standard. In addition, when the fiber is taken from the already manufactured first sheet 1B for the main body or the first sheet 1S for the side and the elongation is measured, the length of the fiber to be measured cannot be set to 20 mm, that is, the length of the fiber to be measured. Is less than 20 mm, the measurement is performed with the gripping interval set to 10 mm or 5 mm.

  The ratio (mass ratio, former: latter) of the first resin component and the second resin component in the heat-extensible composite fiber that is a high elongation fiber is 10:90 to 90:10, particularly 20: at the raw material stage. It is preferable that it is 80-80: 20, especially 50: 50-70: 30. As the fiber length of the heat-extensible composite fiber, one having an appropriate length is used according to the manufacturing method of the first sheet for main body 1B or the first sheet for side 1S. When manufacturing the 1st sheet | seat 1B for main bodies, or the 1st sheet | seat 1S for sides, for example by the card | curd method so that it may mention later, it is preferable that fiber length shall be about 30-70 mm.

  The fiber diameter of the heat-extensible composite fiber, which is a high elongation fiber, is appropriately selected according to the specific application of the first main body sheet 1B or the first side sheet 1S at the raw material stage. When the first sheet for main body 1B or the first sheet for side 1S is used as a constituent member of an absorbent article such as a top sheet of the absorbent article, a sheet having a size of 10 μm to 35 μm, particularly 15 μm to 30 μm is used. preferable. The fiber diameter is measured by the following method.

[Measurement of fiber diameter]
As the fiber diameter of the fiber, the fiber diameter (μm) is measured by magnifying the cross section of the fiber 200 to 800 times using a microscope VH-8000 (manufactured by Keyence Corporation). The cross section of the fiber is obtained by cutting the fiber using a feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). For each extracted fiber, the fiber diameter when approximated to a circle is measured at five locations, and the average value of the five measured values is taken as the fiber diameter.

  In the raw material stage, as the heat-extensible conjugate fiber that is a high elongation fiber, in addition to the above-described heat-extensible conjugate fiber, Japanese Patent No. 4131852, Japanese Patent Laid-Open No. 2005-350836, Japanese Patent Laid-Open No. 2007-303035 The fibers described in JP-A No. 2007-204899, JP-A 2007-204901, JP-A 2007-204902, and the like can also be used.

  In the napkin 10, the first sheet 1B for main body or the first sheet 1S for side is preferably a fiber 11 having a large diameter portion 17 and small diameter portions 16, 16 having different fiber diameters as shown in FIG. Is included. As shown in FIG. 9, the first sheet for main body 1B or the first sheet for side 1S focuses on one of the constituent fibers 11 of the first sheet for main body 1B or the first sheet for side 1S. The constituent fiber 11 has a large-diameter portion 17 having a large fiber diameter sandwiched between two small-diameter portions 16 and 16 having a small fiber diameter between adjacent fused portions 12 and 12. Yes. Preferably, as shown in FIG. 9, paying attention to one constituent fiber 11 of the constituent fibers 11 of the main body first sheet 1B or the first side sheet 1S, the intersection with the other constituent fibers 11 A small-diameter portion 16 having a small fiber diameter is formed to extend with substantially the same fiber diameter from a fusion-bonded portion 12 formed by heat-sealing. Then, paying attention to the single constituent fiber 11, the large-diameter portion 17 having a fiber diameter larger than that of the small-diameter portion 16 between the small-diameter portions 16 and 16 extending from the adjacent fusion portions 12 and 12. Are extended with substantially the same fiber diameter. More preferably, the first sheet 1B for the main body or the first sheet 1S for the side pays attention to one constituent fiber 11, and from one fused part 12 of the adjacent fused parts 12, 12, to the other. The constituent fibers 11 arranged in the order of the small-diameter portion 16 on the side of the one fused portion 12, the one large-diameter portion 17, and the small-diameter portion 16 on the other fused portion 12 side toward the fused portion 12. Have. As described above, the low-rigidity small-diameter portion 16 is adjacent to the fusion-bonding portion 12 which is a portion where the rigidity of the first main body sheet 1B or the first side sheet 1S is increased. The flexibility of the sheet 1B or the first side sheet 1S is improved, and the touch is improved. In addition, the flexibility of the first main body sheet 1 </ b> B or the first side sheet 1 </ b> S is further improved as the number of the small-diameter parts 16 having a plurality of large-diameter parts 17, in other words, the constituent fibers 11 is low. Becomes even better.

  Further, in the napkin 10, the first main body sheet 1B or the first side sheet 1S is one of the constituent fibers 11 of the first main body sheet 1B or the first side sheet 1S as shown in FIG. Focusing on the constituent fiber 11, the constituent fiber 11 having a plurality of large diameter portions 17 (two in the napkin 10) is provided between the adjacent fusion portions 12 and 12. Preferably, the first sheet for main body 1B or the first sheet for side 1S pays attention to one constituent fiber 11, and from one fused portion 12 of the adjacent fused portions 12, 12, to the other. A small diameter portion 16 on the side of one fusion portion 12, a first large diameter portion 17, a small diameter portion 16, a second large diameter portion 17, and the other fusion portion 12 side toward the fusion portion 12. The constituent fibers 11 are arranged in the order of the small diameter portion 16. The first sheet 1B for the main body or the first sheet 1S for the side pays attention to one constituent fiber 11, and between the adjacent fused portions 12, 12, the large diameter portion 17 is improved in the touch and the nonwoven fabric strength. From the viewpoint of reduction, it is preferably provided with 1 or more and 5 or less, more preferably 1 or more and 3 or less.

The ratio (L ₁₆ / L ₁₇ ) of the fiber diameter (diameter L ₁₆ ) of the small diameter portion 16 to the fiber diameter (diameter L ₁₇ ) of the large diameter portion 17 is preferably 0.5 or more and 0.8 or less, more preferably 0. .55 or more and 0.7 or less. Specifically, the fiber diameter (diameter L ₁₆ ) of the small-diameter portion 16 is preferably 5 μm or more and 28 μm or less, more preferably 6.5 μm or more and 20 μm or less, and particularly preferably 7.5 μm or more and 16 μm or less from the viewpoint of improving the touch. is there. The fiber diameter (diameter L ₁₇ ) of the large diameter portion 17 is preferably 10 μm or more and 35 μm or less, more preferably 13 μm or more and 25 μm or less, and particularly preferably 15 μm or more and 20 μm or less from the viewpoint of improving the touch.
The fiber diameters (the diameters L ₁₆ and L ₁₇ ) of the small diameter part 16 and the large diameter part 17 are measured in the same manner as the fiber diameter measurement described above.

  Further, in the napkin 10, the first main body sheet 1B or the first side sheet 1S is one of the constituent fibers 11 of the first main body sheet 1B or the first side sheet 1S as shown in FIG. Focusing on the constituent fiber 11, the change point 18 from the small diameter portion 16 adjacent to the fusion portion 12 to the large diameter portion 17 is the interval T between the fusion portions 12 and 12 adjacent to the fusion portion 12. It is preferable to be arranged within a range of 1/3. Here, the changing point 18 of the first main body sheet 1B or the first side sheet 1S extends from the small diameter portion 16 extending with a small fiber diameter with a fiber diameter larger than the small diameter portion 16. The large-diameter portion 17 does not include a portion that continuously changes gradually or a portion that continuously changes over a plurality of stages, and means a portion where the fiber diameter changes extremely in one step. When the one constituent fiber 11 is a heat-extensible composite fiber, the change point 18 of the first sheet for main body 1B or the first sheet for side 1S is the first resin component constituting the core portion. It does not include a state in which the fiber diameter is changed by peeling between the second resin component constituting the sheath part, and means a portion where the fiber diameter is changed by stretching.

  The change point 18 is arranged within a range of １ ／ of the interval T between the adjacent fused portions 12, 12 from the fused portion 12, that is, the first sheet for main body 1 </ b> B or the first for the side. The constituent fibers 11 of the sheet 1S are extracted at random, and the constituent fibers 11 are formed using a JCM-5100 (trade name) manufactured by JEOL Ltd. as a scanning electron microscope as shown in FIG. Are magnified so that the space between the adjacent fused portions 12 and 12 can be observed (100 to 300 times). Next, the interval T between the centers of the adjacent fused portions 12 and 12 is divided into three equal parts, and the region AT on the side of one fused portion 12, the region BT on the side of the other fused portion 12, and the center region CT Break down. This means that the change point 18 is arranged in the area AT or the area BT. Further, the change point 18 is arranged within a range of １ ／ of the interval T between the fusion parts 12, 12 adjacent to the fusion part 12, or the first sheet 1 </ b> B for the main body or the first sheet 1 </ b> S for the side. Means that when 20 constituent fibers 11 of the first main body sheet 1B or the first side sheet 1S are extracted at random, the constituent fibers 11 in which the change points 18 are arranged in the region AT or the region BT are as follows. The nonwoven fabric which has at least 1 or more in 20 constituent fibers 11 is meant. Specifically, the number of the constituent fibers 11 is preferably 1 or more, more preferably 5 or more, and particularly preferably 10 or more, from the viewpoint of improving the touch.

Moreover, in the napkin 10, the first sheet 1B for the main body or the first sheet 1S for the side is a constituent fiber in which the number of fibers having the change point 18 in the constituent fibers constituting the side region 13c constitutes the top region 13a. Are formed more than the number of fibers having the change point 18 and the number of fibers having the change point 18 in the constituent fibers constituting the bottom region 13b. Such a configuration makes it difficult for the shape of the first main body sheet 1B and the first side sheet 1S to be deformed. Therefore, since the hollow structure of the surface sheet 2 or the hollow structure of the side sheet 5 can be maintained, it is preferable from the viewpoint of wearing feeling and anti-moisture performance. Further, since the number of fibers having the change point 18 of the side region 13c is relatively small, the body fluid absorbed by the absorbent body 4 moves from the bottom region 13b of the main body first sheet 1B toward the top region 13a. This makes it difficult to return the liquid to the skin facing surface. The side region 13c with respect to the number of fibers having the change point 18 in the constituent fibers constituting the top region 13a (N _13a ) or the number of fibers having the change point 18 in the component fibers constituting the bottom region 13b (N _13b ) The ratio (N _13c / N _13a , N _13c / N _13b ) of the number (N _13c ) of fibers having changing points in the constituent fibers to be formed is preferably 2 or more and 20 or less, more preferably 5 or more and 20 or less. Specifically, regarding the specific value of the number of fibers having the change point 18 of the first main body sheet 1B or the first side sheet 1S, the number of fibers having the change point 18 in the constituent fibers constituting the top region 13a. (N _13a ) is preferably 1 or more and 15 or less, more preferably 5 or more and 15 or less. Further, the number (N _13b ) of fibers having the change point 18 in the constituent fibers constituting the bottom region 13b is preferably 1 or more and 15 or less, more preferably 5 or more and 15 or less. Further, the number (N _13c) of fibers having the change point 18 in the constituent fibers constituting the side region 13c is preferably 5 or more and 20 or less, and more preferably 10 or more and 20 or less. The method for measuring the number of fibers having the change point 18 is as follows.

[Measurement method of the number of fibers having the change point 18 in the constituent fibers constituting the top region 13a, the bottom region 13b, or the side region 13c]
Regarding the number of fibers having the change point 18 in the constituent fibers 11 constituting the top region 13a, at the upper part when the thickness of the first sheet for main body 1B or the first sheet for side 1S is equally divided into three in the Z direction. The vicinity of the apex of a certain top region 13a is magnified and observed using a scanning electron microscope (adjusted to a magnification capable of measuring about 30 to 60 fiber cross sections; 50 to 500 times), and the constituent fibers 11 constituting the top region 13a are 20 This is extracted at random, and the number of fibers having the change point 18 in the 20 constituent fibers 11 is counted. This is the number of fibers having a change point 18 in the constituent fibers constituting the top region 13a. The measurement is performed at three places, and the average is the number of fibers having the change point 18 in the constituent fibers constituting the top region 13a of the sample. Similarly, regarding the number of fibers having the change point 18 in the constituent fibers 11 constituting the bottom region 13b, the lower part when the thickness of the first main body sheet 1B or the first side sheet 1S is equally divided into three in the Z direction. It is obtained by measuring the vicinity of the bottom point of the bottom region 13b, which is a part of Similarly, regarding the number of fibers having the change point 18 in the constituent fibers 11 constituting the side region 13c, the thickness of the first main body sheet 1B or the first side sheet 1S is divided into three equal parts in the Z direction. Determine by measuring the central part. Note that JCM-5100 (trade name) manufactured by JEOL Ltd. is used as the scanning electron microscope. Similarly, the number of fibers having the change point 18 is also measured for the first side sheet 1S.

Local layer thickness T _L of the first sheet 1S for the first sheet 1B or for side curved body irregularities may be different at each site of the first sheet in the 1S for the first sheet 1B or for side body It may be adjusted as appropriate depending on the application. The layer thickness T _L1 of the top region 13a is preferably 0.1 mm or greater and 3.0 mm or less, and more preferably 0.2 mm or greater and 2.0 mm or less. The layer thickness T _L2 of the bottom region 13b is preferably 0.1 mm or greater and 3.0 mm or less, and more preferably 0.2 mm or greater and 2.0 mm or less. The layer thickness T _L3 of the side region 13c is preferably 0.1 mm or greater and 3.0 mm or less, and more preferably 0.2 mm or greater and 2.0 mm or less. By setting the relationship between the layer thicknesses T _L1 , T _L2 , and T _L3 within this range, it is possible to realize appropriate cushioning properties during use.

The layer thickness _TL is measured by the following method.
The layer thickness _TL is measured by cutting the topsheet 2 or the sidesheet 5 along the thickness direction Z using a feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). The thickness of each layer is measured by enlarging the section of the cut sheet about 20 times with a Keyence digital microscope VHX-900.

  A small amount of fiber colorant, antistatic property agent, lubricant, hydrophilic agent, or other fiber treatment agent adheres to the surface of the constituent fibers 11 of the first main body sheet 1B or the first side sheet 1S. May be.

  As a method for attaching the fiber treatment agent to the surface of the constituent fiber 11, various known methods can be employed without any particular limitation. For example, application by spraying, application by a slot coater, application by roll transfer, immersion in a fiber treatment agent, and the like can be mentioned. These treatments may be performed on the fibers before being made into a web, or after the fibers are made into a web by various methods. However, it is necessary to perform the process before the hot air blowing process described later. The fiber having the fiber treatment agent attached to the surface is dried at a temperature sufficiently lower than the melting point of the polyethylene resin (for example, 120 ° C. or less) by, for example, a hot air blowing type dryer.

The formation material of each structural member of the napkin 10 of this embodiment mentioned above is demonstrated.
The first sheet 1B for the main body constituting the top sheet 2 and the first sheet 1S for the side constituting the side sheet 5 are heat-sealed at the fusion part at the intersection of the constituent fibers of the fiber web containing the high elongation fibers. Then, it is suitably manufactured by a method for manufacturing a non-woven fabric comprising a fusing process for forming a fiber sheet and a stretching process for stretching the fiber sheet in one direction. Since the manufacturing method of the 1st sheet | seat 1B for main bodies and the 1st sheet | seat 1S for sides is the same, the manufacturing method of the 1st sheet | seat 1B for main bodies is mentioned as an example, and is demonstrated.
One embodiment of the method for manufacturing the first sheet for main body 1B will be described with reference to FIG. 10, taking the above-described preferable method for manufacturing the first sheet for main body 1B as an example. FIG. 10 schematically shows a preferable manufacturing apparatus 100 used in the method for manufacturing the first main body sheet 1B. The manufacturing apparatus 100 is suitably used for manufacturing an air-through nonwoven fabric. The manufacturing apparatus 100 includes a web forming unit 200, a hot air processing unit 300, a stretching unit 400, and a lower layer sheet bonding unit 500 in this order from the upstream side to the downstream side of the manufacturing process.

  As shown in FIG. 10, the web forming unit 200 includes a web forming apparatus 201. A card machine is used as the web forming apparatus 201. As a card machine, the thing normally used in the technical field of an absorbent article can be used without a restriction | limiting in particular. Instead of the card machine, other web manufacturing apparatuses such as airlaid apparatuses can be used.

  As shown in FIG. 10, the hot air processing unit 300 includes a hood 301. Inside the hood 301, hot air can be blown by an air-through method. The hot air processing unit 300 includes an endless conveyor belt 302 made of a breathable net. The conveyor belt 302 circulates in the hood 301. The conveyor belt 302 is made of a resin such as polyethylene terephthalate or a metal.

  The temperature of the hot air blown in the hood 301 and the heat treatment time are preferably adjusted so that the intersections of the high elongation fibers included in the constituent fibers 11 of the fiber web 1b are heat-sealed. More specifically, the temperature of the hot air is preferably adjusted to a temperature higher by 0 ° C. to 30 ° C. than the melting point of the resin having the lowest melting point among the constituent fibers 11 of the fiber web 1b. The heat treatment time is preferably adjusted to 1 to 5 seconds according to the temperature of the hot air. Further, from the viewpoint of promoting further entanglement between the constituent fibers 11, the wind speed of the hot air is preferably about 0.3 m / second to 1.5 m / second. Moreover, it is preferable that a conveyance speed is about 5 m / min-100 m / min.

  The extending | stretching part 400 is provided with a pair of uneven | corrugated roll 401,402 which can mutually mesh | engage as shown in FIG.10 and FIG.11. The pair of concave and convex rolls 401 and 402 are formed so as to be heatable, and are formed by alternately arranging large-diameter convex portions 403 and 404 and small-diameter concave portions (not shown) in the roll axis direction. The uneven rolls 401 and 402 may or may not be heated, but the heating temperature when heating the uneven rolls 401 and 402 makes it easy to stretch the high elongation fibers included in the constituent fibers 11 of the fiber sheet 1a described later. From the viewpoint, it is preferable to be not less than the glass transition point of the resin having the highest glass transition point in the high elongation fiber and not more than the melting point of the resin having the lowest melting point in the high elongation fiber. More preferably, the temperature is 10 ° C. higher than the glass transition point of the fiber and 10 ° C. lower than the melting point, more preferably 20 ° C. higher than the glass transition point of the fiber, and 20 ° C. lower than the melting point. is there. For example, when the core / sheath fiber is used as the fiber, PET (core) having a glass transition point of 67 ° C. and a melting point of 258 ° C./PE (sheath) having a glass transition point of −20 ° C. and a melting point of 135 ° C. is used. The temperature is preferably 67 ° C. or higher and 135 ° C. or lower, more preferably 77 ° C. or higher and 125 ° C. or lower, still more preferably 87 ° C. or higher and 115 ° C. or lower.

  In addition, in the manufacturing apparatus 100, as shown in FIG. 11, the interval (pitch) between the large-diameter convex portions 403, 403 adjacent to each other in the roll axis direction of the concave / convex roll 401 and the roll axis direction of the concave / convex roll 402 are adjacent. The spacing (pitch) between the large-diameter convex portions 404 and 404 is the same spacing (pitch) w, and the spacing (pitch) w is such that the high elongation fibers included in the constituent fibers 11 of the fiber sheet 1a are successfully used in the stretching apparatus. From the viewpoint of stretching and extending the previously described small-diameter portion to the large-diameter portion adjacent to the fusion-bonded portion to improve the touch, it is preferably 1 mm or more and 10 mm or less, particularly preferably 1.5 mm or more. 8 mm or less. From the same viewpoint, as shown in FIG. 11, the pressing amount t of the pair of concave and convex rolls 401 and 402 (the interval between the vertex of the large-diameter convex portion 403 and the vertex of the large-diameter convex portion 404 adjacent to each other in the roll axis direction) is The thickness is preferably 1 mm or more and 3 mm or less, and particularly preferably 1.2 mm or more and 2.5 mm or less. From the same viewpoint, the mechanical stretch ratio is preferably 1.5 times or more and 3.0 times or less, and particularly preferably 1.7 times or more and 2.8 times or less.

  The lower layer sheet joining portion 500 includes a concavo-convex roll 402 and a flat roll 501 having a smooth surface, and a main body having a concavo-convex shape between the large-diameter convex portion 403 of the concavo-convex roll 402 and the peripheral surface of the flat roll 501. The first sheet 1B for use and the second sheet 21 for main body are joined by heating and pressurizing.

A method for manufacturing the first main body sheet 1B using the manufacturing apparatus 100 having the above configuration will be described.
First, as shown in FIG. 10, in the web forming unit 200, a short fiber-shaped constituent fiber 11 having a heat-extensible composite fiber that is a high elongation fiber is used as a raw material, and a web forming apparatus 201 that is a card machine is used. A fiber web 1b is formed (web forming step). The fiber web 1b manufactured by the web forming apparatus 201 is in a state where its constituent fibers 11 are loosely entangled with each other, and has not yet achieved shape retention as a sheet.

  Next, as shown in FIG. 10, the fiber sheet 1 a is formed by heat-sealing the intersections of the constituent fibers 11 of the fiber web 1 b including high elongation fibers at the fusion part 12 (fusing step). Specifically, the fiber web 1b is conveyed onto the conveyor belt 302, and hot air is blown in an air-through manner while passing through the hood 301 by the hot air processing unit 300. When hot air is thus blown by the air-through method, the constituent fibers 11 of the fiber web 10 are further entangled, and at the same time, the intersections of the entangled fibers are thermally fused (see FIG. A fiber sheet 1a having shape retention is produced. It is preferable that the high elongation fiber (heat-extensible composite fiber), which is the constituent fiber 11 of the fiber sheet 1a manufactured as described above, is hardly stretched by hot air.

  Next, as shown in FIG. 10, the fused fiber web 1a is stretched in one direction (stretching step). Specifically, the fused fiber web 1a having a shape-retaining property as a sheet is conveyed between a pair of concave and convex rolls 401 and 402, as shown in FIGS. 12 (a) to 12 (c). In addition, the fiber web 1a is stretched, and a large fiber diameter is sandwiched between two small-diameter portions 16 and 16 having a small fiber diameter in one constituent fiber 11 between adjacent fusion portions 12 and 12. The large diameter portion 17 is formed, and the change point 18 from the small diameter portion 16 to the large diameter portion 17 is set to be 1/3 of the interval T between the fusion portions 12 and 12 adjacent to the fusion portion 12. Form within the range. Specifically, as shown in FIG. 12A, the fiber sheet 1a in which the intersections of the constituent fibers 11 are thermally fused at the fusion part 12 is conveyed between a pair of concave and convex rolls 401 and 402. Then, the fiber web 1a is stretched in the orthogonal direction (CD, roll axis direction) orthogonal to the machine direction (MD, flow direction). When the fiber sheet 1a is stretched in the orthogonal direction (CD, roll axis direction), the adjacent fused portions 12, 12 fixing the constituent fibers 11 shown in FIG. Is actively stretched in the orthogonal direction (CD, roll axis direction). In particular, as shown in FIG. 12B, local contraction is likely to occur first in the vicinity of each fusion part 12 that fixes the constituent fibers 11, and 1 between the adjacent fusion parts 12, 12. With respect to the constituent fiber 11, two small-diameter portions 16, 16 are formed at both ends, and a portion sandwiched between the two small-diameter portions 16, 16 becomes a large-diameter portion 17. A large-diameter portion 17 sandwiched between 16 is formed. In this way, local contraction is likely to occur first in the vicinity of each fusion part 12, so that the change point 18 from the small diameter part 16 to the large diameter part 17 is adjacent to the fusion part 12 adjacent to the fusion part 12. It is formed within a range of 1/3 of the interval T between the twelve.

  Then, with respect to one constituent fiber 11 between some adjacent fused portions 12 and 12, as shown in FIG. 12 (c), in a state where there is room for expansion (extension margin), It is stretched in the orthogonal direction (CD, roll axis direction), the large diameter portion 17 between the adjacent fused portions 12, 12 is stretched, and a plurality of small diameter portions 16 are formed in the large diameter portion 17. become.

  In the stretching step, the small diameter portion 16 and the large diameter portion 17 are formed from the high elongation fiber, and at the same time, the large diameter convex portion 403 of the concave / convex roll 401 and the large diameter convex portion of the concave / convex roll 402 in the fiber sheet 1a. A portion located between the portions 404 is extended more than other portions. In this case, since the constituent fiber of the fiber sheet 1a is a high elongation fiber, even if it is stretched, it is not cut and is successfully stretched. The part located between the large diameter convex part 403 of the uneven | corrugated roll 401 and the large diameter convex part 404 of the uneven | corrugated roll 402 among the fiber sheets 1a of the convex strip part 13B in the 1st sheet | seat 1B for main bodies intended. Since it is the side part area | region 13c, the distance between fibers increases in the side part area | region 13c compared with before extending | stretching, without cut | disconnecting a fiber in the side part area | region 13c. As a result, the fiber density of the side region 13c is lower than other parts, and air permeability is improved. And since the cut | disconnection has not arisen in the fiber which comprises the side part area | region 13c, the intensity | strength of the protruding item | line part 13B is maintained at a high level. As a result, even if a load is applied to the ridge portion 13B, the ridge portion 13B is not easily crushed.

  The main body first sheet 1 </ b> B manufactured as described above is conveyed to the sheet joining portion of the lower layer sheet joining portion 500 while being deformed into the uneven shape by the uneven roll 402. The belt-like main body second sheet 21 unwound from the roll-shaped roll 21 'is supplied to the sheet joining portion, and the uneven main body first sheet 1B is a belt-like main body second sheet. 21 is introduced between the concavo-convex roll 402 and the flat roll 501. Between the concavo-convex roll 402 and the flat roll 501, the concave portion 14 </ b> B portion of the concavo-convex first body sheet 1 </ b> B and the belt-shaped second body sheet 21 have a large-diameter convex portion 404 of the concavo-convex roll 402. And the peripheral surface of the flat roll 501 are joined via a joint 15 formed by being heated and pressurized. In this way, the band-shaped topsheet 2 is obtained in which the first main body sheet 1B is joined to the second main body sheet 21 in the concave strip portion 14B. The belt-like topsheet 2 is introduced into the napkin 10 production line after being wound up, or is introduced into the napkin 10 production line without being wound up.

  In addition, in the case of the side sheet 5, after manufacturing the uneven | corrugated 1st sheet | seat 1S for 1st side like the main body 1st sheet | seat 1B of the surface sheet 2, it overlapped with the strip | belt-shaped side 2nd sheet | seat 51 for side. The state is introduced and introduced between the uneven roll 402 and the flat roll 501. Between the concavo-convex roll 402 and the flat roll 501, the concave portion 14 </ b> S portion of the concavo-convex side first sheet 1 </ b> S and the strip-shaped side second sheet 51 have a large-diameter convex portion 404 of the concavo-convex roll 402. And the peripheral surface of the flat roll 501 are joined via a joint 15 formed by being heated and pressurized. In this way, the belt-like side sheet 5 is obtained in which the first side sheet 1S is joined to the second side sheet 51 in the concave portion 14S.

  As the second sheet 21 for the main body constituting the top sheet 2 and the second sheet 51 for the side constituting the side sheet 5, it is possible to use non-woven fabrics obtained by various manufacturing methods, which are aggregates of fibers of thermoplastic resin. it can. For example, an air-through nonwoven fabric in which heat-bonding points between fibers are formed on a fiber web obtained by the card method or airlaid method, and a heat-bonding point between fibers is formed on a fiber web obtained by the card method by a heat roll method. Various nonwoven fabrics such as heat roll nonwoven fabric, heat embossed nonwoven fabric, spun lace nonwoven fabric, needle punched nonwoven fabric, and resin bonded nonwoven fabric can be used.

  In particular, as the nonwoven fabric constituting the second sheet 21 for the main body, a hydrophilic nonwoven fabric having a higher degree of hydrophilicity and density than the first sheet 1B for the main body absorbs the liquid that has passed through the first sheet 1B for the main body. It is preferable from the viewpoint of smoothly shifting to the body 4. The hydrophilicity of the second main body sheet 21 and the first main body sheet 1B, and the hydrophilicity of the second side sheet 51 and the first side sheet 1S depend on the amount of hydrophilic agent applied and the type of hydrophilic agent. Can be adjusted. The density of the second sheet 21 for the main body and the second sheet 51 for the side can be adjusted to the fiber web obtained by the card method by heat fusion of fibers by the heat roll method or adhesion by heat roll embossing. Moreover, adjustment by using a nonwoven fabric of a spunbond method or a melt blow method is possible.

Especially as the second sheet 21 or second sheet 51 for side body for an apparent density of 0.005 g / cm ³ or more 0.5 g / cm ³ or less, in particular 0.01 g / cm ³ or more 0.2 g / cm ³ or less It is preferable to use a non-woven fabric. By using a nonwoven fabric having such a density as the second sheet 21 for the main body or the second sheet 51 for the side, a density gradient is formed on the top sheet 2, so that the excretion liquid from the top sheet 2 is more easily drawn. Become. Thereby, absorption speed and dry feeling at the time of wearing can be increased, and uncomfortable feeling can be reduced. As the 2nd sheet | seat 21 for main bodies, or the 2nd sheet | seat 51 for sides, an air through nonwoven fabric, a heat roll embossed nonwoven fabric, an airlaid nonwoven fabric, a resin bond nonwoven fabric, etc. can be used suitably, for example.

  As the back sheet 3, various kinds of materials conventionally used for back sheets of absorbent articles can be used without particular limitation. For example, a liquid-impermeable or water-repellent resin film, a resin film and a nonwoven fabric can be used. A laminate sheet or the like can be used.

  As the absorbent body 4 (the lower layer absorbent body 40 and the upper layer absorbent body 41), various types conventionally used for absorbent bodies of absorbent articles can be used without particular limitation, and examples thereof include wood pulp, synthetic fiber and the like. A fiber aggregate made of hydrophilic fibers, or a fiber aggregate in which a particulate water-absorbing polymer is held can be used. Examples of water-absorbing polymers include sodium polyacrylate, (acrylic acid-vinyl alcohol) copolymer, cross-linked sodium polyacrylate, (starch-acrylic acid) graft copolymer, and (isobutylene-maleic anhydride) copolymer. Examples thereof include a polymer and a saponified product thereof, and polyaspartic acid. The absorbent body 4 may be configured to include a liquid-retaining absorbent core made of the fiber assembly and the like, and a liquid-permeable core wrap sheet that covers the absorbent core. The absorbent core and the core wrap sheet may be joined to each other at a predetermined site by a joining means such as a hot melt adhesive. As a core wrap sheet which coat | covers an absorptive core, water-permeable sheets, such as paper, such as tissue paper, various nonwoven fabrics, and an apertured film, can be used, for example.

The 1st joining line 61 and the 2nd joining line 62 which join the surface sheet 2 and the side sheet | seat 5 can be formed by apply | coating an adhesive agent or giving a heat seal or an ultrasonic seal. In the case where the first bonding line 61 and the second bonding line 62 are formed by applying an adhesive, an adhesive is used as a known means, for example, a slot coat gun, a spiral spray gun, a spray gun, or a dot gun. Use to apply. As the adhesive to be applied, for example, a hot melt adhesive is preferably used. The application amount of the hot melt adhesive is preferably 3 g / m ² or more and 10 g / m ² or less.

  As a method of forming the wing portion adhesive portion 71, the main body adhesive portion 72 (displacement preventing portion) or the rear flap portion adhesive portion 73, a method conventionally used for absorbent articles used by being fixed to clothing such as underwear is used without any particular limitation. be able to. For example, the pressure-sensitive adhesive can be formed by directly applying to the back sheet 3, or the other side of the pressure-sensitive adhesive tape coated with the pressure-sensitive adhesive can be bonded to the back sheet. Examples of the pressure-sensitive adhesive used for forming the pressure-sensitive adhesive portion include emulsion-based, water-based, and solvent-based pressure-sensitive adhesives. Moreover, it is preferable that the misalignment preventing portion is formed by applying a pressure sensitive adhesive such as a hot melt pressure sensitive adhesive from the viewpoint of obtaining excellent displacement prevention performance and stable productivity. As such an adhesive, those usually used for this type of article can be adopted without limitation, but it is preferable to use a synthetic rubber-based block copolymer having a basic structure similar to natural rubber. . Examples of such a block copolymer include styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-propylene-styrene copolymer (SEPS), and styrene-butadiene-styrene block copolymer (SBS). And styrene-ethylene-butylene-styrene copolymer (SEBS). The pressure-sensitive adhesive preferably contains 10 to 65% by weight, particularly 30 to 50% by weight, of one or more base polymers selected from these block copolymers. In addition, as long as the gap prevention part can prevent the gap between an absorptive main body and the clothing which fixes it, it may not be adhesive.

  The linear pressing groove 8 (the first horizontal pressing groove 81, the vertical pressing groove 82, the second horizontal pressing groove 83, and the third horizontal pressing groove 84) is a pressing process (so-called embossing) with or without heat, or It can be formed according to a conventional method by embossing such as ultrasonic embossing. In the linear compressed groove 8, the topsheet 2 and the absorber 4 are not shown in the figure, but are bonded (bonded) by pressure bonding with an adhesive or by heat fusion. In the expression that the surface sheet 2 and the absorbent body 4 are bonded, another sheet such as a second sheet is interposed between the surface sheet 2 and the absorbent body 4, and the surface sheet and the other sheet. And the other sheet and the absorbent body 4 are joined (bonded). What is necessary is just to set the width | variety of the linear pressing groove 8 similarly to the linear pressing groove in this kind of absorbent article.

The effect of the napkin 10 mentioned above is demonstrated.
Since the napkin 10 includes the hydrophilic side sheet 5, even if a body fluid such as menstrual blood adheres to the skin facing surface of the side sheet 5, the body fluid hardly flows on the skin facing surface of the side sheet 5. It is difficult to lead to leakage. Moreover, in the napkin 10, the skin facing surface side of the topsheet 2 has a hook-like protruding strip portion 13B and a recessed strip portion extending in the longitudinal direction X as shown in FIGS. 2 (a), 2 (b) and FIG. Since 14B has the 1st sheet | seat 1B for main bodies of the uneven structure alternately arranged by the horizontal direction Y, since the area which the skin and the surface sheet 2 which wear are contacting becomes small, a rubbing feeling or discomfort is felt during wearing. Hard to give. Further, in the napkin 10, the side sheet 5 has laterally extending ridge-like convex portions 13S and concave portions 14S extending in the longitudinal direction X as shown in FIGS. 2 (a), 2 (b), and 5. It has the 1st sheet | seat 1B for main bodies of the uneven structure alternately arranged by Y. As shown in FIG. And in the napkin 10, as shown to Fig.2 (a) and FIG.2 (b), at the time of wear, in each side part along the vertical direction X of the absorptive main body 10B, the protruding item | line part of the 1st sheet | seat 1B for main bodies 13B meshes with the concave strip portion 14S of the first side sheet 1S, and the convex strip portion 13S of the first side sheet 1S meshes with the concave strip portion 14S of the first main body sheet 1B. Therefore, the side sheet 5 is difficult to be displaced from the side portion along the longitudinal direction X of the top sheet 2 during wearing, and the side sheet 5 is difficult to twist, and it is difficult to give a sense of incongruity during wearing. Further, during wearing, the convex strip portion 13S of the hollow structure side sheet 5 and the concave strip portion 14B of the hollow structure top sheet 2 or the concave strip portion 14S of the hollow structure side sheet 5 and the top sheet 2 of the hollow structure. Cushion feeling is obtained by engaging with the protruding strips 13B, and it is difficult to give a sense of incongruity during wearing. Moreover, even if the bodily fluid absorbed by the absorbent body 4 is difficult to return to the skin facing surface side by the top sheet 2 having a hollow structure and the bodily fluid absorbed by the absorbent body 4 spreads in the lateral direction Y, the hollow structure The side sheet 5 and the top sheet 2 having a hollow structure mesh with each other, so that it is difficult for the liquid to return to the skin-facing surface of the side sheet 5 and side leakage of body fluid is difficult to occur. Furthermore, although the side sheet 5 is hydrophilic, the body fluid absorbed by the absorbent body 4 is laterally absorbed by the structure in which the hydrophilic side sheet 5 having a hollow structure and the hydrophilic surface sheet 2 having a hollow structure are engaged with each other. Difficult to spread in the direction Y and hardly cause side leakage of body fluids.

  Further, in the napkin 10, the first sheet 1B for the main body having a concavo-convex structure has a fiber density in the side region 13c between the top region 13a and the bottom region 13b, as shown in FIGS. It is formed lower than the fiber density of 13a and the fiber density of the bottom region 13b. Thus, when the fiber density of the top region 13a and the bottom region 13b is higher than the fiber density of the side region 13c, the ridges 13S of the side sheet 5 having a hollow structure and the ridges 14B of the top sheet 2 having a hollow structure. Or the top region 13a becomes a support when the concave portion 14S of the side sheet 5 having the hollow structure and the convex portion 13B of the top sheet 2 having the hollow structure are engaged with each other. The shape portion 13B is not easily crushed and a hollow structure can be maintained. In particular, in the napkin 10, the first side sheet 1S having a concavo-convex structure is also formed such that the fiber density of the top region 13a and the bottom region 13b is higher than the fiber density of the side region 13c, as shown in FIGS. ing. For this reason, the structure in which the hydrophilic side sheet 5 having a hollow structure and the hydrophilic surface sheet 2 having a hollow structure mesh with each other is hardly crushed, and the hollow structure can be maintained. Therefore, the bodily fluid absorbed by the absorbent body 4 is less likely to spread in the lateral direction Y, and the lateral leakage of the bodily fluid is less likely to occur. Further, as shown in FIGS. 3 and 7, the first sheet for main body 1B has a density gradient in which the fiber density in the side region 13c is lower than the fiber density in the bottom region 13b. Since the body fluid absorbed in the skin does not easily move to the skin-facing surface side, it is difficult for the fluid to return, and the side leakage of body fluid is further unlikely to occur.

  It is preferable to have the following configuration from the viewpoint of more surely expressing the above-described effects.

The width (W _14B ) (see FIG. 13) of the concave strip portion 14B of the first main body sheet 1B constituting the top sheet 2 is the width of the convex strip portion 13S of the first side sheet 1S constituting the side seat 5 (see FIG. 13). W _13S ) (see FIG. 13) is preferably the same or wider. The ratio (W _14B / W _13S ) of the width (W _14B ) of the recess 14B to the width (W _13S ) of the protrusion 13S is preferably 1 or more, and more preferably 1.2 or more. Also, it is preferably 5 or less, more preferably 2 or less, and preferably 1 or more and 5 or less, more preferably 1.2 or more and 2 or less. Specifically, the width (W _14B ) of the recess 14B of the first main body sheet 1B is preferably 0.3 mm or more and 10 mm or less, and more preferably 0.5 mm or more and 3 mm or less. The width (W _13S ) of the ridges 13S of the first side sheet 1S is preferably 0.06 mm or more and 12.5 mm or less, and more preferably 0.25 mm or more and 3 mm or less.
The width of the concave strip portion 14B (W _14B ) and the width of the convex strip portion 13S (W _13S ) (see FIG. 13) are the surface sheet 2 using a feather razor (part number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). Alternatively, the side sheet 5 is cut along the thickness direction Z. The cross section of the cut sheet is measured by enlarging it about 20 times with a Keyence digital microscope VHX-900.

The height (H _13B ) (see FIG. 13) of the ridge 13B of the first main body sheet 1B constituting the top sheet 2 is the height of the ridge 13S of the first side sheet 1S constituting the side sheet 5. It is preferable that the _height is equal to or higher than (H _13S ) (see FIG. 13). The ratio of the height of the convex portion 13S _{(H 13S)} convex portions 13B of the height to the _{(H 13B) (H 13B /} H 13S) is preferably 1.0 or more, it is 1.2 or more More preferably, it is preferably 3.0 or less, more preferably 2.0 or less, and preferably 1.0 or more and 3.0 or less, and 1.2 or more and 2. More preferably, it is 0 or less. Specifically, the height (H _13B ) of the ridge 13B of the first main body sheet 1B is preferably 0.45 mm or more and 2.0 mm or less, and more preferably 0.6 mm or more and 1.8 mm or less. The height (H _13S ) of the ridges 13S of the first side sheet 1S is preferably 0.15 mm to 2.0 mm, and more preferably 0.30 mm to 1.5 mm.
The height (H _13S ) of the ridge _13S and the height (H _13B ) of the _{ridge 13B} (see FIG. 13) are measured using a feather razor (part number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). The sheet 2 or the side sheet 5 is cut along the thickness direction Z. The cross section of the cut sheet is measured by enlarging it about 20 times with a Keyence digital microscope VHX-900.

The width (W _13B ) (see FIG. 13) of the ridges 13B of the first main body sheet 1B constituting the top sheet 2 (see FIG. 13) is the width of the ridges 13S of the first side sheet 1S constituting the side sheets 5 (see FIG. W _13S ) (see FIG. 13) is preferably the same or wider. The ratio of the width of the convex portion 13S _{(W 13S)} convex portions 13B of the width to _{(W 13B) (W 13B /} W 13S) is preferably 0.8 or more, further preferably 1 or more Also, it is preferably 5 or less, more preferably 2 or less, and preferably 0.8 or more and 5 or less, more preferably 1 or more and 2 or less. Specifically, the width (W _13B ) of the ridge 13B of the first main body sheet 1B is preferably 0.3 mm or more and 10 mm or less, and more preferably 0.5 mm or more and 3 mm or less.
The width (W _13B ) (see FIG. 13) of the ridge portion 13B is obtained by using the feather razor (part number FAS-10, manufactured by Feather Safety Razor Co., Ltd.) and the surface sheet 2 or the side sheet 5 along the thickness direction Z. Disconnect. The cross section of the cut sheet is measured by enlarging it about 20 times with a Keyence digital microscope VHX-900.

The width (W _13B ) (see FIG. 13) of the convex portion 13B of the first main body sheet 1B constituting the top sheet 2 is the width (W _14B ) of the concave portion 14B of the first main body sheet 1B (see FIG. 13). 13) is preferably the same as or wider than the first sheet 1B for main body and the first sheet 1S for side mesh with each other.
The ratio of the width of the concave portion 14B _{(W 14B)} convex portions 13B of the width to _{(W 13B) (W 13B /} W 14B) is more preferably it is 1 or more preferably, 1.2 or higher Also, it is preferably 5 or less, more preferably 2 or less, and preferably 1 or more and 5 or less, more preferably 1.2 or more and 2 or less. Within this range, the shape in which the first main body sheet 1B and the first side sheet 1S are engaged is easily stabilized.

When the surface sheet 2 is viewed in plan as shown in FIG. 4, the interval L _13B between the tops of the protruding strips 13B adjacent in the lateral direction Y is preferably 1 mm or more, more preferably 1.5 mm or more, 15 mm or less is preferable, 10 mm or less is more preferable, 1 mm or more and 15 mm or less are preferable, and 1.5 mm or more and 10 mm or less are still more preferable.
When the side sheet 5 is viewed in plan as shown in FIG. 6, the distance L _13S between the tops of the protruding strips 13S adjacent in the lateral direction Y is preferably 1 mm or more, more preferably 1.5 mm or more, 15 mm or less is preferable, 10 mm or less is more preferable, 1 mm or more and 15 mm or less are preferable, and 1.5 mm or more and 10 mm or less are still more preferable.

The basis weight of the first sheet 1B for body constituting the surface sheet 2 is preferably 15 g / ^{m 2} or more 50 g / ^{m 2} or less the average value of the entire sheet, 20 g / ^{m 2} or more 40 g / ^{m 2} or less is more preferable.
The basis weight of the first sheet 1S for side constituting the side sheet 5 is preferably 15 g / ^{m 2} or more 50 g / ^{m 2} or less the average value of the entire sheet, 20 g / ^{m 2} or more 40 g / ^{m 2} or less is more preferable.

As mentioned above, although this invention was demonstrated based on the preferable embodiment, the absorbent article of this invention is not restrict | limited to the napkin 10 of the said embodiment at all, and can be changed suitably.
For example, as shown in FIG. 1, the absorbent body 4 of the napkin 10 has the middle-high portion 42, but may not have the middle-high portion 42.
Moreover, in the napkin 10, as shown in FIG. 1, although the side sheet 5 and the surface sheet 2 are joined by the linear 1st joining line 61 and the linear 2nd joining line 62, it is another shape. May be joined by a joining line, or may be joined by joining sites arranged intermittently in the longitudinal direction X.

  Moreover, the sanitary napkin which does not have the back flap part 10F other than the sanitary napkin which has a pair of back flap parts 10F and 10F may be sufficient as the absorbent article of this invention. In addition to the sanitary napkin, the absorbent article of the present invention may be a panty liner (cage sheet), an incontinence pad, or the like.

10 Sanitary napkins (absorbent articles)
10B Absorbent body 10W Wing part 10F Back flap part 10S Side flap part 2 Surface sheet 1B First sheet for main body 11 Constituent fiber 12 Fusion part 13B Convex part 14B Concave part 15 Joint part 16 Small diameter part 17 Large diameter part 18 Change Point 21 2nd sheet 3 for main body Back sheet 4 Absorber 40 Lower layer absorbent body 41 Upper layer absorbent body 42 Middle and high part 5 Side sheet 1S First sheet for side 13S Convex part 14S Concave part 51 Second sheet 61 for side First joint Line 62 2nd joining line 71 Wing part adhesion part 72 Main body adhesion part 73 Back flap part adhesion part 8 Linear compression groove 81 1st lateral compression groove 82 Vertical compression groove 83 2nd lateral compression groove 84 3rd lateral compression groove 100 Manufacture Device 200 Web Forming Unit 201 Web Forming Device 300 Hot Air Processing Unit 301 Hood 302 Conveyor Belt 400 Stretching 401, 402 irregularities roll 403, 404 large 径凸 part

Claims (6)

A liquid-permeable surface sheet that forms a skin facing surface, a back sheet that forms a non-skin facing surface, and an absorbent body interposed between the two sheets, the longitudinal direction corresponding to the wearer's front-rear direction, and the Absorbency comprising an absorbent main body having a transverse direction perpendicular to the vertical direction, and a side sheet disposed over the entire length of the absorbent main body on the skin facing surface side of both side portions along the vertical direction of the absorbent main body Goods,
The top sheet is hydrophilic and has a first sheet for main body on the skin facing surface side and a second sheet for main body disposed adjacent to the non-skin facing surface side of the first sheet for main body. ,
Each of the side sheets is hydrophilic and has a first sheet for side on the non-skin facing surface side and a second sheet for side disposed adjacent to the skin facing surface side of the first sheet for side. And
The first sheet for the main body and the first sheet for the side are nonwoven fabrics having a concavo-convex structure in which streaky ridges and ridges extending in the vertical direction are alternately arranged in the horizontal direction,
The surface sheet has a joint portion formed by joining the first sheet for main body and the second sheet for main body at the concave portion of the first sheet for main body, and the first sheet for main body It has a hollow structure between the ridge and the second sheet for the main body,
Each of the side sheets has a joining portion formed by joining the first side sheet and the second side sheet at the concave portion of the first side sheet. It has a hollow structure between the ridge and the second sheet for side,
At the time of wearing the absorbent article, the ridges of the first main body sheet engage with the concave ridges of the first side sheet, respectively, on both side parts of the absorbent main body, The absorptive article arranged so that the above-mentioned convex line part of one sheet may mesh with the above-mentioned concave line part of the above-mentioned first sheet for main parts.   2. The absorbent article according to claim 1, wherein a width of the concave stripe portion of the first main body sheet is the same as or wider than a width of the convex stripe portion of the first side sheet.   The absorbent article according to claim 1 or 2, wherein a height of the ridge portion of the first main body sheet is the same as or higher than a height of the ridge portion of the first side sheet.   The width | variety of the said protruding item | line part of the said 1st sheet | seat for main bodies is the absorbent article of any one of Claims 1-3 wider than the width | variety of the said protruding item | line part of the said 1st sheet | seat for sides.   The absorbent article according to any one of claims 1 to 4, wherein a width of the convex portion of the first sheet for main body is the same as or wider than a width of the concave portion of the first sheet for main body. The side area between the top area and the bottom area in a cross-sectional view of the first sheet for main body has a fiber density lower than the fiber density in the top area and the fiber density in the bottom area. The absorbent article of any one of -5.

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