JP6271657B1 - Top sheet for absorbent articles - Google Patents

Abstract

Provided is a top sheet for an absorbent article that further reduces the contact area with the skin of the wearer, prevents liquid from remaining on the surface, prevents liquid once absorbed from returning to the surface, and improves the feeling of use. thing. A top sheet 1 for absorbent articles of the present invention has a first fiber layer 11 and a second fiber layer 12. The topsheet 1 is used so that the first fiber layer 11 is located on the skin contact surface side of the wearer. The 1st fiber layer 11 has the high convex part 1b and the low convex part 1s which protruded toward the 1st fiber layer 11 side from the 2nd fiber layer 12 side, and the high convex part 1b and the low convex part 1s are internal. Is filled with fibers constituting the first fiber layer 11. When the high convex portion 1b is viewed in a cross section in the thickness direction Z, the hydrophilicity of the high convex portion top portion 1bu on the top portion 1bt side in the first fiber layer 11 is equal to the high convex portion on the second fiber layer 12 side in the first fiber layer 11. The hydrophilicity of the 2nd fiber layer 12 is higher than the hydrophilicity of the high convex part top part 1bu higher than the hydrophilicity of the bottom part 1bd. [Selection] Figure 6

Description

  The present invention relates to a surface sheet for absorbent articles.

  The present applicant previously has a first fiber layer and a second fiber layer laminated thereon, and is used for an absorbent article having a plurality of protrusions protruding toward the first fiber layer. When the convex portion is virtually cross-sectional view in the thickness direction, the hydrophilicity of the second fiber layer is different between the upper side of the first fiber layer and the lower side of the first fiber layer. A surface sheet having a degree higher than the hydrophilicity of the first fiber layer was proposed (Patent Document 1).

  Apart from this, the present applicant first has a large polygonal region and a small polygonal region surrounded by a plurality of embossed portions, and the embossed portion defines the tops of the large polygonal region and the small polygonal region. Proposed surface sheets for absorbent articles that have high convex portions in each large polygonal region and low convex portions in each small polygonal region ( Patent Document 2).

Japanese Patent No. 5809341 JP-A-2015-186543

  According to the surface sheet described in Patent Document 1, it is difficult for the liquid to remain on the surface, and the liquid once absorbed is unlikely to return to the surface, so that the feeling of use is improved. However, there has been a need for a surface sheet that further reduces the contact area with the wearer's skin and that the liquid hardly remains on the surface, and that the liquid once absorbed is unlikely to return to the surface. Further, Patent Document 1 does not describe anything about providing two types of convex portions. In addition, there is no description or suggestion regarding the hydrophilicity gradient when paying attention to the high convex portion that easily comes into contact with the wearer's skin among the two types of convex portions.

  Moreover, according to the surface sheet of patent document 2, while further reducing a contact area with a wearer's skin, a feeling of stickiness and stuffiness can further be reduced and a usability | use_condition improves. However, Patent Document 2 does not describe anything about the liquid residue on the surface. In addition, Patent Document 2 does not describe or suggest any hydrophilicity gradient when paying attention to a high convex portion that easily comes into contact with the wearer's skin among the two types of convex portions.

  Therefore, this invention is providing the surface sheet for absorbent articles which can eliminate the fault which the prior art mentioned above has.

  This invention is a surface sheet for absorbent articles which has a 1st fiber layer and the 2nd fiber layer laminated | stacked on this, and this 1st fiber layer is located in a wearer's skin contact surface side, The first fiber layer includes a plurality of high convex portions protruding from the second fiber layer side toward the first fiber layer side, and a plurality of low convex portions having a height lower than the high convex portion. The high convex portion and the low convex portion are filled with fibers constituting the first fiber layer, and when the high convex portion is viewed in a cross section in the thickness direction so as to pass through the top portion, The hydrophilicity of the top part of the high convex part on the top side in the first fiber layer is higher than the hydrophilicity of the bottom part of the high convex part on the side of the second fiber layer in the first fiber layer, and the hydrophilicity of the second fiber layer. However, the present invention provides a top sheet for absorbent articles that is higher in hydrophilicity than the top of the high convex portion.

  According to the present invention, while further reducing the contact area with the wearer's skin, the liquid is unlikely to remain on the surface, and the liquid once absorbed is unlikely to return to the surface, improving the feeling of use.

FIG. 1: is the top view which looked at the sanitary napkin which is an absorbent article using the surface sheet of this invention from the surface sheet side. 2 is a cross-sectional view schematically showing a cross section taken along line II-II in FIG. FIG. 3 is a perspective view showing a top sheet for absorbent articles according to an embodiment of the present invention. FIG. 4 is a plan view showing the shape and arrangement pattern of the fusion bonded portion in the top sheet shown in FIG. FIG. 5 is an enlarged plan view showing a part of the top sheet shown in FIG. 4 in an enlarged manner. FIG. 6 is a cross-sectional view schematically showing a cross section taken along line VI-VI in FIG. FIG. 7 is an enlarged plan view showing the shape and arrangement pattern of the fusion bonded portion in the high convex portion shown in FIG. FIG. 8 is an enlarged plan view showing the shape and arrangement pattern of the fusion bonded portion in the low convex portion shown in FIG. 9 is a cross-sectional view schematically showing a cross section taken along line IX-IX shown in FIG. 10 is a cross-sectional view schematically showing a cross section taken along line XX shown in FIG. 11 is a cross-sectional view schematically showing a cross section taken along line XI-XI shown in FIG. FIG. 12 is a schematic diagram showing a manufacturing apparatus suitably used in the method for manufacturing the top sheet shown in FIG. FIG. 13: is a top view which shows the shape and arrangement | positioning pattern of the fusion splicing part in another example of the surface sheet for absorbent articles of this invention. FIG. 14 is a plan view showing the shape and arrangement pattern of the fusion bonded part in still another example of the top sheet for absorbent articles of the present invention.

Below, the surface sheet for absorbent articles of this invention is demonstrated, referring drawings based on the surface sheet 1 (henceforth the surface sheet 1) of the preferable embodiment.
The topsheet 1 of this embodiment is a multilayer nonwoven fabric having a first fiber layer 11 and a second fiber layer 12 laminated thereon, as shown in FIGS. The topsheet 1 is used so that the first fiber layer 11 is located on the skin contact surface side of the wearer. The X direction in the figure is the second direction, which is the same direction as the machine direction (MD direction) and the vertical direction of the napkin 10. Further, the Y direction in the figure is a first direction orthogonal to the second direction, and is the same direction as the direction orthogonal to the machine direction (MD direction) (CD direction) and the lateral direction of the napkin 10. The Z direction in the figure is the thickness direction. In addition, the napkin 10 longitudinal direction is a direction corresponding to the wearer's front-rear direction when worn.

  1 and 2 show a sanitary napkin 10 using a top sheet 1. A sanitary napkin 10 (hereinafter also referred to as a napkin 10) is provided between a front sheet 1 disposed on the skin contact surface side, a back sheet 2 disposed on the non-skin contact surface side, and between the two sheets 1 and 2. The absorbent body 3 long in the longitudinal direction X is provided. The napkin 10 has a pair of side sheets 4 and 4 arranged on both side portions 10s and 10s along the vertical direction X, and a pair of wing portions 5 and 5 extending outward in the lateral direction Y are formed. ing. As shown in FIG. 1, the napkin 10 is formed symmetrically with respect to a center line CL extending in the vertical direction X.

  In addition, in this specification, a "skin contact surface" is a surface distribute | arranged to a wearer's skin side at the time of wear among front and back both surfaces of each member, such as the surface sheet 1 which comprises the napkin 10, The “non-skin contact surface” is a surface of the front and back surfaces of each member such as the topsheet 1 that is directed to the side opposite to the wearer's skin when worn.

  The napkin 10 will be described in detail. As shown in FIG. 1, the napkin 10 has a central part A which is an area where the wing parts 5 and 5 are located, and the abdomen side of the wearer from the central part A when the sanitary napkin 10 is worn. And the rear part C which is arranged on the wearer's back side rather than the central part A when the napkin 10 is worn. When the napkin 10 is worn, the central portion A usually includes a portion that is disposed so as to face the excretion portion (such as the vaginal opening) of the wearer. In other words, the wing portion 5 is formed in a vertical region including the excretion facing region of the napkin 10 (region facing the excretion portion of the wearer).

  As shown in FIG. 2, each of the top sheet 1 and the back sheet 2 covers the entire surface of the absorbent body 3 on the skin contact surface side and the entire surface of the non-skin contact surface side, and extends from the periphery of the absorbent body 3. It has an extending part. As shown in FIG. 2, the length of the top sheet 1 in the horizontal direction Y is shorter than the length of the back sheet 2 in the horizontal direction Y. As shown in FIGS. 1 and 2, each of the pair of side sheets 4 and 4 is disposed on the skin contact surface side of the top sheet 1 and over the entire side portion along the longitudinal direction X of the top sheet 1. It has fixed and has the extension part extended to the outward of the horizontal direction Y from the side part of the surface sheet 1. FIG. In the napkin 10, the extending portion of the back sheet 2 in the lateral direction Y and the extending portion of the side sheet 4 in the lateral direction Y are fixed by adhesion, fusion, or the like. The wing portion 5 is formed extending outward in the lateral direction Y in the central portion A rather than the rear portion C. Adhesives are respectively applied to the non-skin contact surfaces of the lateral direction Y center of the back sheet 2 of the napkin 10 and the extended part of the back sheet 2 of the wing part 5, so that the napkin 10 is put on underwear such as shorts. A fixing portion 5a for fixing is formed. In addition, each side seat | sheet 4 arrange | positions and fixes the elastic member extended in the vertical direction X in the vicinity of the edge part of the horizontal direction Y inner side (centerline CL side), and when wearing, the elastic member You may make it form the leak-proof cuff from which the part of predetermined width separates from the surface sheet 1 by the contraction force.

  Further, the napkin 10 has a round compression groove (not shown) formed by embossing the topsheet 1 and the absorber 3 and integrally compressing them, extending in the longitudinal direction X and extending from the front part B to the rear part. It may extend to C. For example, the compressed groove (not shown) is preferably formed in a single round shape connected to the front part B, the both side parts 10s, 10s and the rear part C of the napkin 10. The compression groove (not shown) is formed by compressing the top sheet 1 and the absorber 3 from the skin contact surface side with or without heat.

  As the back surface sheet 2, the absorber 3, and the side sheet 4 constituting the napkin 10 described above, the same materials as those conventionally used in the technical field can be used without particular limitation. For example, as the back sheet 2, a water-repellent nonwoven fabric having a high water pressure resistance such as a liquid-impermeable film made of a synthetic resin or a spunbond-meltblown-spunbond laminated nonwoven fabric can be used. As the absorbent body 3, an absorbent core made of absorbent polymer particles and a fiber material and covered with tissue paper can be used. As the side sheet 4, a water-repellent nonwoven fabric having a high water pressure resistance, such as a spunbond-meltblown-spunbond laminated nonwoven fabric, or the like can be used.

  For fixing the top sheet 1, the back sheet 2, the absorber 3 and the side sheet 4, it is usually an adhesive used for absorbent articles such as sanitary napkins, or fusion means such as heat embossing, ultrasonic embossing, high frequency embossing, etc. Is used.

  Although the surface sheet 1 of one embodiment constituting the napkin 10 described above can be a non-woven fabric other than the air-through nonwoven fabric, a heat shrinking step described later and a step of heat-sealing the web to form the nonwoven fabric are performed simultaneously. Therefore, an air-through nonwoven fabric is preferable.

  “Air-through non-woven fabric” refers to a non-woven fabric manufactured through a process of spraying a fluid of 50 ° C. or higher, for example, gas or water vapor, onto a web or a non-woven fabric. It also means a nonwoven fabric produced by adding this process to the produced nonwoven fabric or a nonwoven fabric produced by performing some process after this process. The laminated nonwoven fabric of the present invention includes not only an air-through nonwoven fabric but also a composite of an air-through nonwoven fabric and a fiber sheet or film material such as another nonwoven fabric.

  In the surface sheet 1 which is a laminated nonwoven fabric, as shown in FIG. 3, the first fiber layer 11 and the second fiber layer 12 are adjacent and in direct contact with each other, and other layers are interposed between the layers 11 and 12. Not done. The first fiber layer 11 and the second fiber layer 12 are distinguished from each other by factors such as the material type of the fibers constituting the layers, the thickness of the fibers, the presence / absence of hydrophilic treatment, and the layer formation method. When the cross section in the thickness direction of the surface sheet 1 is enlarged with an optical microscope (manufactured by Keyence Co., Ltd., VHX-1000 digital microscope), the boundary portion between both layers 11 and 12 can be observed due to these factors. In the napkin 10, the top sheet 1 is used with the first fiber layer 11 disposed on the skin contact surface side and the second fiber layer 12 disposed on the non-skin contact surface side. That is, the napkin 10 includes the absorbent body 3 on the second fiber layer 12 side of the topsheet 1.

  In the topsheet 1, as shown in FIG. 3, the first fiber layer 11 includes a plurality of high convex portions 1b protruding from the second fiber layer 12 side toward the first fiber layer 11 side, and the high convex portions 1b. And a plurality of low convex portions 1s having a low height. Preferably, as shown in FIG. 4, the topsheet 1 has a plurality of high protrusions 1 b, a plurality of low protrusions 1 s, and connecting protrusions extending continuously over the high protrusions 1 b and the low protrusions 1 s. Part 1c. The connection convex part 1c is formed so that the first fiber layer 11 protrudes lower than the low convex part 1s from the second fiber layer 12 side toward the first fiber layer 11 side. The high convex portion 1 b and the low convex portion 1 s are filled with fibers constituting the first fiber layer 11. And the connection convex part 1c is also filled with the fiber which comprises the 1st fiber layer 11 inside.

  In the surface sheet 1, each of the first fiber layer 11 and the second fiber layer 12 is a fiber layer composed of randomly deposited fibers, and is composed of a laminate of a plurality of layers further subdivided. Not a thing.

  In the topsheet 1, the second fiber layer 12 is a heat-shrinkable fiber layer including heat-shrinkable fibers that have been heat-shrinked. On the other hand, in the topsheet 1, the first fiber layer 11 is a non-heat-shrinkable fiber layer that is laminated on the second fiber layer 12 and includes non-heat-shrinkable fibers. The topsheet 1 includes a plurality of fusion bonding portions 6 in which the first fiber layer 11 and the second fiber layer 12 are fusion bonded. Preferably, as shown in FIGS. 3 and 4, the topsheet 1 is partially formed by a plurality of fusion bonding portions 6 in which the first fiber layer 11 and the second fiber layer 12 are regularly arranged. The heat-shrinkable fibers of the second fiber layer 12 on the non-skin contact surface side are heat-shrinked and bonded together. The top sheet 1 has a plurality of concave portions recessed by a fusion bonding portion 6 embossed from the skin contact surface side of the first fiber layer 11, and a plurality of convex portions on a non-embossed portion not embossed. The part is formed. The fiber density of the portion that becomes a concave portion by the fusion-bonding portion 6 is higher than that of the convex portion that is not fusion-bonded, and is the highest in the topsheet 1.

  The fusion bonding part 6 is formed by various fusion means such as heat embossing and ultrasonic embossing.

  The topsheet 1 has a plurality of large polygonal regions BT surrounded by a plurality of fusion bonding portions 6, and the fusion bonding portions 6 constitute apexes of the large polygonal regions BT. Moreover, the surface sheet 1 has a plurality of small polygonal areas ST smaller in area than the large polygonal area BT and surrounded by the fusion bonding parts 6 forming the apexes of the plurality of large polygonal areas BT. The part 6 also forms the apex part of the small polygonal area ST. Thus, the surface sheet 1 is formed with a polygonal region (large polygonal region BT, small polygonal region ST) surrounded by a plurality of fusion bonding portions 6, and the polygonal region (large polygonal region BT). , Small polygon region ST) is a non-embossed portion. Preferably, as shown in FIGS. 4 and 5, the polygonal region has a plurality of fusion bonding portions 6 as apexes, and a plurality of large polygonal regions BT having a relatively large area surrounded by these, It has a plurality of small polygonal areas ST having an area smaller than that of the large polygonal area BT, which is surrounded as a common apex by the fusion bonding part 6 forming the apex of the plurality of adjacent large polygonal areas BT. . Thus, the large polygonal region BT and the small polygonal region ST adjacent to the large polygonal region BT have the fusion joint portion 6 as a common vertex. In the present specification, “the fusion bonded portion 6 is the apex” or “the fusion bonded portion 6 is the apex” means that the entire fusion bonded portion 6 is the apex. This is not meant to be a typical meaning, but includes a case where a part of the fusion-bonding portion 6 is a vertex. In the surface sheet 1 of the present embodiment, a part of the fusion bonded portion 6 is a vertex of each polygonal region, and the remaining part excluding the vertex of the fusion bonded portion 6 is an edge that forms the outer shape of each polygonal region. It has become a part. In addition, the expression “surrounded by the fusion bonded portion 6” does not mean a region formed inside the fusion bonded portion 6, but means a region formed including the fusion bonded portion 6. To do.

  In detail, in the surface sheet 1, as shown in FIGS. 4 and 5, the large polygonal region BT is surrounded by six fusion bonding portions 6 forming apexes, and the outer shape is a hexagonal shape. Yes. On the other hand, the small polygonal region ST is surrounded by four fusion-bonding portions 6 forming apexes, and the outer shape is a square shape. Then, with respect to the first direction, two adjacent large polygon regions BT, BT are adjacent to two fusion bonding portions 6 (2 of the six fusion bonding portions 6 constituting each large polygon region BT. The two other joint portions 62 (to be described later) are shared, and are separated from each other by sides connecting the two fusion joint portions 6 (two other joint portions 62 to be described later). Further, with respect to the second direction, two adjacent large polygonal regions BT, BT are adjacent to one fusion bonded portion 6 (intermediate to be described later) among the six fusion bonded portions 6 constituting each large polygonal region BT. The joint portion 61) is shared, and is separated from each other by the one fusion joint portion 6 (intermediate joint portion 61 described later). One rectangular small polygon region ST is surrounded by four hexagonal large polygon regions BT. The adjacent small polygonal region ST and each large polygonal region BT share two of the six fusion bonding parts 6 (an intermediate bonding part 61 to be described later and another bonding part 62 to be described later). The two fusion bonded portions 6 (intermediate bonded portion 61 described later and other bonded portion 62 described later) are separated from each other. Therefore, in the surface sheet 1, the four fusion bonding portions 6 constituting the small polygon region ST are all fusion bonding portions constituting the four large polygon regions BT adjacent to the small polygon region ST. 6 and share.

    As shown in FIGS. 4 and 5, the topsheet 1 is formed with a large polygon region row BTL configured by arranging a plurality of large polygon regions BT adjacent to each other along the first direction. Moreover, in the surface sheet 1, the small polygon area | region row | line STL comprised by the several small polygon area | region ST being adjacently arranged along the 1st direction is formed. The large polygon region row BTL and the small polygon region row STL are alternately arranged in the second direction orthogonal to the first direction. That is, the large polygon region row BTL, the small polygon region row STL, the large polygon region row BTL,... Are alternately arranged along the second direction. Further, in the napkin 10, the large polygon row BTL and the small polygon row STL each extend in the lateral direction of the napkin 10 and are alternately arranged in the vertical direction of the napkin 10.

  In the top sheet 1, as shown in FIGS. 5 and 6, a high convex portion 1b having a relatively high height is formed in each large polygonal region BT. Moreover, in the surface sheet 1, the multiple high convex part 1b is distribute | arranged along the 1st direction, and the high convex part row | line | column 1bL is comprised. On the other hand, in each small polygon area | region ST, the low convex part 1s whose height is lower than the high convex part 1b is formed. Moreover, in the surface sheet 1, the low convex part 1s is arranged in multiple numbers along the 1st direction, and comprises the low convex part row | line 1sL. And the high convex part row | line 1bL and the low convex part row | line | column 1sL are alternately arrange | positioned by the 2nd direction orthogonal to a 1st direction. That is, along the second direction, the high convex portion row 1bL, the low convex portion row 1sL, the high convex portion row 1bL,... Are alternately arranged. And the high convex part 1b of the high convex part row | line 1bL and the low convex part 1s of the low convex part row | line 1sL are arrange | positioned on the surface sheet 1 in zigzag form. In other words, the high protrusions 1b and the low protrusions 1s are alternately arranged in the oblique directions with respect to the first direction and the second direction, respectively. If the topsheet 1 having such a configuration is used for a napkin 10 that is an example of an absorbent article, the top 1st of the low convex portion 1s that is lower than the high convex portion 1b is unlikely to contact the wearer's skin during use. The contact area with the wearer's skin can be reduced. And the liquid excreted during use easily moves to the top 1bt of the high convex part 1b in contact with the wearer's skin, and the liquid hardly remains on the surface, so that the feeling of use is improved.

  In the napkin 10, the distance between adjacent small polygon regions ST and ST in one small polygon row STL is shorter than the distance between the small polygon regions ST and ST that are closest to each other in the vertical direction X. For this reason, the body fluid is more easily diffused along the longitudinal direction X than the lateral direction Y, and the body fluid is easily suppressed from leaking from both side portions 10 s and 10 s in the lateral direction Y of the napkin 10. In the napkin 10, the distance between the large polygon regions BT and BT adjacent to each other in one large polygon row BTL is shorter than the distance between the large polygon regions BT and BT that are closest in the vertical direction X. For this reason, the high convex part 1b does not fall easily toward the horizontal direction Y, and the body fluid leakage from the both side parts 10s, 10s of the napkin 10 in the horizontal direction Y is more easily suppressed. In addition, the distance between each polygon area | region means here the distance between the center points of each polygon area | region.

  In the surface sheet 1, as shown in FIGS. 4 and 5, the fusion-bonding portion 6 is between the two high convex portions 1b and 1b that are closest to each other in the second direction, and in the first direction. An intermediate joint 61 is provided between the two low convex portions 1s and 1s located at the closest position. Specifically, with respect to the second direction, between the two closest high convex portions 1b, 1b among the high convex portions constituting the closest high convex portion row 1bL, 1bL, and with respect to the second direction. There is one intermediate joint 61 between the two low convex portions 1s, 1s closest to each other in the first direction constituting the low convex portion row 1sL located between the closest high convex portion rows 1bL, 1bL. doing. In the surface sheet 1, the plurality of fusion bonded portions 6 are formed of two types of bonded portions, the first being the intermediate bonded portion 61, and the second being the remaining other bonded portions excluding the intermediate bonded portion 61. Part 62. In the present specification, “one joined portion” refers to the shape of an embossed portion that can be regarded as one in appearance, and the shape of the embossed portion is composed of a plurality of dots or broken lines. Even so, it is called “one joint”.

  In the surface sheet 1, as shown in FIGS. 4 and 5, each intermediate joint portion 61 constitutes each small polygon region ST by square small polygon regions ST and ST adjacent in the first direction. Six fusion joints which are shared as one fusion joint 6 of the two fusion joints 6 and constitute each polygonal region BT by hexagonal large polygonal regions BT and BT adjacent in the second direction. One of the joints 6 is shared as a fusion joint 6. Accordingly, each intermediate joint 61 is arranged at an intermediate position between the two low convex portions 1s, 1s closest to the first direction, and is intermediate between the two high convex portions 1b, 1b closest to the second direction. Arranged in position.

  In the surface sheet 1, as shown in FIG. 7, each intermediate joint 61 has each large polygonal area from the center point of the apex part forming the apex of the two large polygonal areas BT located closest to the second direction. A bi-directionally extending shape portion 61a extending along the side forming the outer shape of the BT is provided. As described above, in the topsheet 1, the large polygonal regions BT and BT adjacent in the second direction share one vertex. And in the surface sheet 1, all the vertex parts of each rectangular small polygon area | region ST are sharing with the vertex part of the hexagonal large polygon area | region BT adjacent to this small polygon area | region ST. Therefore, the two-direction extending shape portions 61a and 61a adjacent in the second direction are in contact with each other, and the intermediate joint portion 61 forms the outer shape of one hexagonal large polygonal region BT adjacent in the second direction from the apex. And extending in the four directions extending along the side forming the outer shape of the other hexagonal large polygonal region BT adjacent in the second direction from the apex. It is formed in a letter shape. The X-shaped intermediate joint portion 61 has a shape in which four projecting portions 61e extend from the apex in plan view. The four protrusions 61e have the same length, and the X-shaped intermediate joint 61 has a line parallel to the first direction passing through the center point and a line parallel to the second direction passing through the center point. Each has a line-symmetric shape.

  In the surface sheet 1, as shown in FIG. 7, the X-shaped intermediate joint portion 61 is excellent in that the intersection angle θ1 between the protruding portions 61e in the second direction reduces the contact area with the skin in the surface sheet 1. From the viewpoint of maintaining a good touch and improving the visual impression, it is preferably 50 ° or more, particularly preferably 70 ° or more, and preferably 170 ° or less, particularly preferably 130 ° or less, more specifically, The angle is preferably from 50 ° to 170 °, and more preferably from 70 ° to 130 °. In the surface sheet 1, the crossing angle θ1 is 90 °.

  In the surface sheet 1, as shown in FIG. 7, each other joint portion 62 includes the joint portion in the small polygon region ST sharing one vertex and the two large polygon regions BT and BT adjacent in the first direction. Extending along a side forming a part of the outer shape of the rectangular small polygonal region ST and forming a part of the outer shape of one hexagonal large polygonal region BT from the vertex that is the center point of Further, a part of the outer shape of the rectangular small polygonal region ST is formed from the vertex that is the center point of the vertex, and a part of the outer shape of the other hexagonal large polygonal region BT is formed. 3 extending along a side and forming a part of the outer shape of one hexagonal large polygonal region BT and extending along a side forming a part of the outer shape of the other hexagonal large polygonal region BT. It is formed in a direction extending shape, that is, in a Y shape. The other joint portion 62 in the Y shape has a shape in which three projecting portions 62e extend from the vertex that is the center point in plan view. The three projecting portions 62e have the same length, and the Y-shaped other joint portion 62 has a line-symmetric shape with respect to a line parallel to the second direction passing through the center point.

  In the surface sheet 1, as shown in FIG. 7, the Y-shaped other joint portion 62 has an intersection angle θ <b> 2 between the protrusions 62 e that reduces the contact area with the skin in the surface sheet 1 and maintains a good touch. Further, from the viewpoint of improving the visual impression, it is preferably 50 ° or more, particularly preferably 70 ° or more, and preferably 170 ° or less, particularly preferably 130 ° or less, more specifically 50 ° or more and 170 °. Or less, more preferably 70 ° or more and 130 ° or less. In the top sheet 1, the intersection angle θ2 is 130 °.

  In the surface sheet 1, as shown in FIG. 7, the four protrusions 61e of the X-shaped intermediate joint 61 and the three protrusions 62e of the Y-shaped other joint 62 each have a length. From the viewpoint of improving the drawability and diffusibility of the liquid in the surface sheet 1 and emotional properties, it is preferably 0.5 mm or more, more preferably 0.7 mm or more, and preferably 5.0 mm or less, more preferably 4 0.0 mm or less, more specifically 0.5 mm or more and 5.0 mm or less, and more preferably 0.7 mm or more and 4.0 mm or less. In the topsheet 1, the four protrusions 61 e of the intermediate joint 61 have the same length from the vertex that is the center point of the vertex. On the other hand, the three projecting portions 62e of the other joint portion 62 have the same length from the apex (the center point of the apex portion) in the topsheet 1. However, it is not limited to the said form and length may differ. For example, two of the three protrusions 62e of the other joint 62 may be the same length and one may be shorter than the other two. In addition, one protrusion 62e among the three protrusions 62e of the other joint part 62 is arranged in parallel with the second direction (X direction) in the topsheet 1.

In the surface sheet 1, as shown in FIG. 7, each fusion bonding part 6 (intermediate bonding part 61 and other bonding part 62) maintains the good touch and draws liquid and diffuses in the surface sheet 1. From the viewpoint of increasing the area, the area of one fusion bonded portion 6 (average of the intermediate bonded portion 61 and the other bonded portion 62) is preferably 1 mm ² or more, more preferably 1.5 mm ² or more, and preferably 15 mm. ² or less, more preferably 12 mm ² or less, more specifically 1 mm ² or more and 15 mm ² or less, more preferably 1.5 mm ² or more and 12 mm ² or less.

In the surface sheet 1, as shown in FIG. 5, the fusion bonded portions 6 (intermediate bonded portions 61 and other bonded portions 62) are regularly separated in the first direction and the second direction at regular intervals. It is provided independently. Each fusion bonded part 6 (intermediate bonded part 61 and other bonded part 62) preferably has a density of 1 / m from the viewpoint of improving the drawability and diffusibility of the liquid in the surface sheet 1 and maintaining good touch. cm ² or more, more preferably 2 pieces / cm ² or more, and preferably 32 pieces / cm ² or less, more preferably 16 pieces / cm ² or less, more specifically 1 piece / cm ² or more and 32 pieces / cm ^2. It is preferably cm ² or less, and more preferably 2 pieces / cm ² or more and 16 pieces / cm ² or less.

  In the surface sheet 1, as shown in FIG. 5, the distance between the fusion bonded portions 6 (intermediate bonded portion 61 and other bonded portions 62) that are closest to each other in the first direction is the drawing of liquid in the surface sheet 1. From the viewpoint of improving the property and diffusibility, and maintaining a good visual impression and touch, it is preferably 0.5 mm or more, more preferably 1.0 mm or more, and preferably 5.0 mm or less, more preferably 4.0 mm. More specifically, it is preferably 0.5 mm or more and 5.0 mm or less, and more preferably 1.0 mm or more and 4.0 mm or less.

  In the surface sheet 1, as shown in FIG. 7, one hexagonal large polygonal region BT is formed by two intermediate joint portions 61 and four other joint portions 62. The two intermediate joints 61 are arranged on a virtual bisector Ly1 extending in parallel with the second direction passing through the center of gravity of the large polygonal region BT in plan view, and pass through the center of gravity of the large polygonal region BT. They are arranged so as to be symmetric with respect to a virtual bisector Lx1 extending parallel to the first direction. The four other joint portions 62 are arranged at the apex portion of the large polygonal region BT other than the apex portion where the two intermediate joint portions 61 are arranged. The two other joints 62 and 62 closest to each other in the first direction are arranged so as to be symmetric with respect to a virtual bisector Ly1 extending parallel to the second direction in plan view. The two other joints 62 and 62 closest to each other in the second direction are arranged so as to be symmetric with respect to a virtual bisector Lx1 extending in parallel with the first direction in plan view. In this way, the two other joints 62 and 62 that are closest to the X direction constituting one hexagonal large polygon region BT are arranged so as to be opposite to each other with respect to the virtual bisector Lx1. Has been.

  In the topsheet 1, as shown in FIG. 8, one rectangular small polygon region ST is formed by two intermediate joint portions 61 and two other joint portions 62. The two intermediate joints 61 are arranged on a virtual bisector Lx2 extending in parallel with the first direction passing through the center of gravity of the small polygon region ST in plan view, and the center of gravity of the small polygon region ST Are arranged so as to be symmetric with respect to an imaginary bisector Ly2 extending in parallel with the second direction passing through. The two other joint portions 62 are arranged on a virtual bisector Ly2 extending in parallel with the second direction in a plan view, and with respect to a virtual bisector Lx2 extending in parallel with the first direction. They are arranged symmetrically. In this way, the two other joints 62 and 62 that are closest to the X direction constituting one rectangular small polygon region ST are opposite to each other with respect to the virtual bisector Lx2. It is arranged in a Y shape and an inverted Y shape.

  As described above, in the topsheet 1, as shown in FIGS. 4 and 5, all the apexes of each rectangular small polygon region ST are hexagonal large polygons adjacent to the small polygon region ST. This is shared with the vertex of the region BT. Therefore, with respect to the second direction, the Y-shaped other joints 62 are arranged in the first direction at equal intervals, and the row of the Y-shaped other joints 62 and the reverse Y-shaped other joints 62 are the first. A row of intermediate joints 61 in which X-shaped intermediate joints 61 are arranged at equal intervals in the first direction between rows of other Y-shaped other joints 62 arranged at equal intervals in the direction. It is arranged. Such an array of three joint rows is arranged at equal intervals in the second direction. And regarding the 1st direction, the X-shaped intermediate junction part 61 is distribute | arranged to the position corresponding to the middle of two Y-shaped other junction parts 62 and 62 nearest to the 1st direction. Regarding the second direction, the Y-shaped other joint 62 and the inverted Y-shaped other joint 62 adjacent to each other in the second direction are arranged on an imaginary line extending in parallel with the second direction.

  In the surface sheet 1, as shown in FIG. 3, the fusion bonded portion 6 (the intermediate bonded portion 61 and the other bonded portion 62) is formed in a portion where the constituent fibers of the surface sheet 1 are consolidated and not embossed. In comparison, the height (thickness) of the top sheet 1 is the lowest (thin). That is, the fiber density of the concave portion formed by the fusion bonded portion 6 (the intermediate bonded portion 61 and the other bonded portion 62) is higher than that of the unembossed portion, and is the highest in the topsheet 1. Depending on the embossing conditions, the constituent fibers may be melted and solidified to form a film. For this reason, the fusion bonded portion 6 (the intermediate bonded portion 61 and the other bonded portion 62) affects the hardness of the topsheet 1 and the excretion of the excretory fluid. From this viewpoint, the ratio of the area of the fusion bonded portion 6 to the total area of the surface sheet, that is, the embossing rate is preferably 5% or more and 30% or less, and particularly preferably 7% or more and 20% or less. . According to the embossing pattern in the topsheet 1, even with such a low embossing rate, the contact area with the wearer's skin can be reduced.

  In the topsheet 1 formed as described above, as shown in FIG. 5, the high convex portion 1b formed in the hexagonal large polygonal region BT is a convex portion having an elliptical planar shape, The low convex portion 1s formed in the small polygonal region ST is a convex portion having a circular planar shape. Further, a connecting convex portion 1c between the high convex portion 1b formed in the large polygon region BT and the low convex portions 1s formed in the four small polygon regions ST adjacent to the large polygon region BT. Is formed.

  In the topsheet 1, as described above, as shown in FIG. 4, one rectangular small polygon region ST is surrounded by four hexagonal large polygon regions BT. When attention is paid to the low convex portion 1s in one rectangular small polygon region ST, the high convex portions 1b in the four hexagonal large polygon regions BT are adjacent to each other. And as shown in FIG. 5, the low convex part 1s in 1 small polygonal area | region ST mutually adjacent and the high convex part 1b in four large polygonal area | regions BT are the fusion | melting which makes the vertex part of a polygonal area | region. More specifically, the connecting projections 1 c arranged between the bonded junctions 6 and 6, specifically, the intermediate projection 61 and the other junction 62 are connected. And the inside of the connection convex part 1c becomes the liquid flow path R in which a liquid moves toward the low convex part 1s from the high convex part 1b. If the topsheet 1 having such a configuration is used for a napkin 10 which is an example of an absorbent article, even if a large amount of liquid is drawn into the high convex portion 1b, the connecting convex portion which is the liquid flow path R. The action of drawing into the low convex portion 1s through 1c is easy to work, and the liquid once absorbed is difficult to return to the surface, so that the feeling of use is improved.

In the surface sheet 1, the height hb (see FIG. 9) at the apex in the thickness direction (Z direction) of the high convex portion 1 b is good for the surface sheet 1 and enhances the density gradient of the fiber by increasing the density gradient of the fiber. From the viewpoint of enhancing the retractability, it is preferably 1.0 mm or more, more preferably 1.5 mm or more, and preferably 7.0 mm or less, more preferably 5.0 mm or less, and more specifically 1.0 mm or more and 7 mm. It is preferably 0.0 mm or less, and more preferably 1.5 mm or more and 5.0 mm or less. The height hb of the high convex portion 1b is the maximum height of the high convex portion, but is also generally the height at a position corresponding to the center of gravity of the large polygonal region BT. The height hb is measured in the same manner as the fiber density ratio (1) of the surface sheet 1 described later.
Further, the rising angle θ3 (see FIG. 10) from the bottom surface of the high convex portion 1b is preferably 70 ° or more, and more preferably from the viewpoint of making it difficult to leave menstrual blood in a portion that touches the skin even during a large amount of menstrual blood. Is 75 ° or more, and preferably 90 ° or less, more preferably 85 ° or less, more specifically 70 ° or more and 90 ° or less, and more preferably 75 ° or more and 85 ° or less. . The ridge angle θ3 is measured simultaneously with the measurement of the height hb.

In the surface sheet 1, the height hs (see FIG. 11) at the apex in the thickness direction (Z direction) of the low convex portion 1 s enhances the good feel of the surface sheet 1 and strengthens the density gradient of the fiber. From the standpoint of improving the retractability, the thickness is preferably 0.4 mm or more, more preferably 0.8 mm or more, and preferably 4.5 mm or less, more preferably 2.5 mm or less, more specifically 0.4 mm or more. It is preferably 4.5 mm or less, and more preferably 0.8 mm or more and 2.5 mm or less. The height hs of the low convex portion 1s is the maximum height of the low convex portion 1s, but is also the height at a position corresponding to the center of gravity in the small polygon region ST. The height hs is measured in the same manner as the fiber density ratio (1) of the topsheet 1 described later.
In addition, the raised angle θ4 (see FIG. 11) from the bottom surface of the low convex portion 1s is preferably 25 ° or more, more preferably from the viewpoint of making it difficult to leave menstrual blood in a portion that touches the skin even during a large amount of menstrual blood. Is 30 ° or more and preferably 70 ° or less, more preferably 65 ° or less, more specifically 25 ° or more and 70 ° or less, and more preferably 30 ° or more and 65 ° or less. . The ridge angle θ4 is measured simultaneously with the measurement of the height hs.

  In the topsheet 1, as shown in FIG. 6, the high convex portion 1 b is filled with the first fiber layer 11 when the high convex portion 1 b is viewed in the thickness direction Z so as to pass through the top portion 1 bt. , A high convex portion top portion 1bu on the top portion 1bt side, a high convex portion bottom portion 1bd on the second fiber layer 12 side opposite to the top portion 1bt, and further a second fiber layer 12. Here, the distinction between the high convex portion top 1bu and the high convex portion bottom 1bd is that when the high convex portion 1b is virtually bisected in the thickness direction Z so as to pass through the top portion 1bt, the first fiber layer 11 is divided into two. Of the two equally divided parts, the part on the top 1bt side is defined as a high convex part top 1bu, and the part on the second fiber layer 12 side is defined as a high convex part bottom 1bd. Further, the low convex portion 1s has a low convex portion top portion 1su on the top portion 1st side that is filled with the first fiber layer 11 when the low convex portion 1s is viewed in a cross section in the thickness direction Z so as to pass through the top portion 1st. And a low convex portion bottom 1sd on the second fiber layer 12 side opposite to the top 1st, and further includes a second fiber layer 12. Here, the distinction between the low convex portion top portion 1su and the low convex portion bottom portion 1sd is that when the low convex portion 1s is virtually bisected in the thickness direction Z so as to pass through the top portion 1st, the first fiber layer 11 is divided into two. Of the two equally divided parts, the part on the top 1st side is defined as a low convex part top 1su, and the part on the second fiber layer 12 side is defined as a low convex part bottom 1sd.

In addition, the thickness at the time of virtually bisecting the high convex part 1b in the thickness direction Z means the thickness in a substantially no-load state. The term “substantially no load” means that the load is 0.049 kPa in order to suppress variation in value due to the properties of the nonwoven fabric, which is an aggregate of fibers.
Further, the thickness when virtually dividing the low convex portion 1s into the thickness direction Z is substantially the same as the thickness when virtually dividing the high convex portion 1b into the thickness direction Z. This means the thickness under no load. The term “substantially no load” means that the load is 0.049 kPa in order to suppress variation in value due to the properties of the nonwoven fabric, which is an aggregate of fibers.

  In the surface sheet 1, as shown in FIG. 6, the fiber density of the low convex part top part 1su is higher than the fiber density of the high convex part top part 1bu, and is lower than the fiber density of the 2nd fiber layer 12. FIG. Preferably, the low convex portion 1s of the three-dimensional dome structure has the highest fiber density among the low convex portions 1s at the apex (reference point of the height hs) of the top portion 1st in the thickness direction (Z direction). It has become. Similarly, the high convex portion 1b of the three-dimensional dome structure has the highest fiber density among the high convex portions 1b at the apex (reference point of the height hs) of the top portion 1bt in the thickness direction (Z direction). ing. And the fiber density of the low convex part top part 1su of the low convex part 1s is higher than the fiber density of the high convex part top part 1bu of the high convex part 1b. The fiber density of the 2nd fiber layer 12 is higher than the fiber density of the low convex part 1s and the high convex part 1b. That is, the fiber density of the second fiber layer 12 is the fiber density at the apex of the top portion 1st of the low convex portion 1s (reference point of the height hs) and the apex of the top portion 1bt of the high convex portion 1b (reference of the height hs). The fiber density at point) is higher. If the topsheet 1 having such a configuration is used for a napkin 10 which is an example of an absorbent article, the liquid excreted during use is transferred to the top 1bt of the high convex portion 1b which is in contact with the wearer's skin. And easily drawn into the interior of the high convex portion 1b, and the liquid hardly remains on the surface. And the liquid drawn in the inside of the high convex part 1b is easy to transfer to the 2nd fiber layer 12, and the liquid once absorbed is hard to return to the surface. In addition, even if a large amount of liquid is drawn into the high convex portion 1b, the action of drawing into the low convex portion 1s with high fiber density is easy to work, and the liquid once absorbed is difficult to return to the surface. A feeling improves. The effect that “the liquid is difficult to return to the surface” is that, when used as the top sheet 1 of the napkin 10, the liquid once absorbed by the absorbent body 3 is difficult to return even if it receives the pressure resistance of the wearer. Is advantageous.

  Fiber at the apex (reference point of height hs) of the thickness direction (Z direction) of the low protrusion 1s with respect to the fiber density db at the apex (reference point of height hb) of the thickness direction (Z direction) of the high protrusion 1b The ratio of the density ds (ds / db) is preferably 1.2 times or more, more preferably 1.5 times or more, and preferably 3.0 times or less from the viewpoint of enhancing the drawability of the excreted body fluid. Further, it is preferably 2.5 times or less, more specifically 1.2 times or more and 3.0 times or less, and more preferably 1.5 times or more and 2.5 times or less.

The ratio of the fiber density of the topsheet 1 can be measured using either one of the two methods (1) and (2) described below.
(1) When the basis weight of the surface sheet 1 is substantially uniform (uniform) (or when it can be determined that it is substantially uniform), the height (thickness) of the cut surface of the surface sheet 1 is measured.
(2) When the basis weight of the top sheet 1 is non-uniform (or when it can be determined that it is non-uniform), the average distance between fibers on the cut surface of the top sheet 1 is measured.

Here, the determination as to whether the basis weight of the topsheet 1 is substantially uniform is performed as follows.
When 10 or more cut samples having a size of 10 cm in the X direction and 10 cm in the Y direction are taken out from the surface sheet 1 and each basis weight is measured, the triple value (3σ) of the standard deviation σ is within 10% of the average μ. If there is no fiber unevenness on the appearance, it is judged to be substantially uniform. However, it is preferable to make a comprehensive judgment in consideration of various factors such as the composition being different in a minute region.

First, the method (1) will be described.
Measurement from the top sheet 1 in plan view by a straight line passing through the center of gravity (vertex in the Z direction) of the high convex portion 1b and the two fusion-bonding portions 6 (intermediate joint portions 61) at both ends, and measuring the high convex portion 1b Create samples for Similarly, cut along a straight line passing through the center of gravity (vertex in the Z direction) of the low convex portion 1s and the two fusion-bonding portions 6 (two intermediate joint portions 61 or two other joint portions 62) at both ends. Then, a sample for measuring the low protrusion 1s is prepared. At this time, care should be taken not to cause a decrease in the height of each measurement sample due to cutting.

The cross section of each measurement sample obtained was measured using an electron microscope JCM-5100 manufactured by JEOL Ltd. under the conditions of a sputtering time of 30 seconds (Pt) and an acceleration voltage of 10 KV. At least one of the fusion bonded portions 6 is photographed, or a situation in which the fusion bonded portion 6 can be understood by combining a plurality of images, and the height (thickness) of each measurement sample is measured from the photographed images. . Note that image measurement may be performed using either a printed matter or a PC screen.
In the method (1), the height hs (thickness) of the central portion of the sample for measuring the low convex portion 1s is divided by the height hb (thickness) of the central portion of the sample for measuring the high convex portion 1b. The ratio (ds / db).

Next, the method (2) will be described.
The cross section is measured in the same manner as in the method (1). In addition to the measurement performed by the method (1), the cross section of each measurement sample is photographed at an enlargement magnification of 500 to 1000 times. In the region where the number of fibers is 3 to 7 in the width direction (plane direction) at the target measurement site (center portion of each measurement sample) of each of the magnified images, an image analyzer (NEWQBE ver. 4.20 made by NEXT) Is used to find the distance between the nearest centers of gravity of the fibers.
In the above measurement, measurement is performed almost entirely in the height (thickness) direction, and the closest distance between the centers of gravity is not caused to overlap. Moreover, about a cross section, it measures at least 3 places, Preferably 5 places, More preferably, 10 places, The average value is used.
In the method of (2), the distance ratio between the nearest centroids at the center of the sample for measuring the low convex portion 1s is divided by the distance between the nearest centroids at the center of the sample for measuring the high convex portion 1b. ds / db).

  In the surface sheet 1, as shown in FIG. 6, each high convex part 1b, each low convex part 1s, and each connection convex part 1c become a solid structure with which the fiber which comprises the 1st fiber layer 11 was satisfy | filled. In addition, the interface between the first fiber layer 11 and the second fiber layer 12 between the fusion bonded portions 6 (the intermediate bonded portion 61 and the other bonded portion 62) is not bonded but is in close contact over the entire area. It has become a state. As described above, no gap is generated between the first fiber layer 11 and the second fiber layer 12.

  In the topsheet 1, the fibers constituting the first fiber layer 11 are fused by an air-through method at the intersections of the fibers. The fibers constituting the high convex portion top portion 1bu and the low convex portion top portion 1su and the fibers constituting the high convex portion bottom portion 1bd and the low convex portion bottom portion 1sd are the same.

  In the surface sheet 1, as a fiber constituting the first fiber layer 11, a heat-fusible fiber, particularly a fiber made of a thermoplastic polymer material is preferably used from the viewpoint of heat-fusibility with the second fiber layer 12. Examples of heat-fusible fibers include heat-fusible core-sheath composite fibers, heat-stretchable fibers, non-heat-stretchable fibers, heat-shrinkable fibers, non-heat-shrinkable fibers, three-dimensional crimped fibers, latent crimpable properties A fiber, a hollow fiber, etc. can be mentioned, In the surface sheet 1, a non-heat-shrinkable fiber is used preferably.

  Examples of the thermoplastic polymer material include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, and polyamides. As the fibers constituting the first fiber layer 11, a core-sheath type composite fiber made of a combination of these thermoplastic polymer materials (for example, polyethylene terephthalate or polypropylene as a core component and polyethylene as a sheath component) Can be preferably used. The core-sheath type composite fiber may be a concentric core-sheath type, an eccentric core-sheath type, a side-by-side type, or an irregular shape, and is preferably a concentric core-sheath type.

  Among the core-sheath type composite fibers, at least the surface of the heat-fusible fiber is preferably formed of a polyolefin resin. When the surface of the heat-fusible fiber that is a constituent fiber of the surface sheet 1 is formed of a polyolefin-based resin, the fiber surface is melted by heat treatment, and the penetration of the fiber treatment agent into the fiber is likely to occur. The effect that the hydrophilicity of a desired part can be reduced efficiently is exhibited. Examples of the polyolefin-based resin that forms the surface of the heat-fusible fiber include polyethylene and polypropylene, and one of these can be used alone or two or more of them can be used in combination.

  The first fiber layer 11 contains, as the heat-fusible fiber, 60% by mass or more, particularly 80% by mass, of a fiber that does not shrink at the shrinkage start temperature of the latent crimpable fiber to be contained in the second fiber layer 12 described later. The content is preferably 100% by mass or less. The first fiber layer 11 may also contain latent crimpable fibers contained in the second fiber layer 12, but the first fiber layer 11 is between the first fiber layer 11 and the second fiber layer 12. From the viewpoint of producing a coarse / dense gradient in which the second fiber layer 12 is dense, the content of the latent crimpable fibers in the first fiber layer 11 is preferably 80% by mass or less.

  The degree of crystallinity when the heat-fusible fiber constituting the first fiber layer 11 is a non-complex fiber (single fiber) is preferably 30% or more, more preferably 35% or more, from the viewpoint of hot air recovery. More preferably, it is 40% or more, and from the viewpoint of texture, it is preferably 60% or less, more preferably 50% or less, and still more preferably 45% or less.

  When the heat-fusible fiber constituting the first fiber layer 11 is a composite fiber having a plurality of types of resins, the high melting point resin having a relatively high melting point and the low melting point resin having a relatively low melting point are as follows: It is preferable to have a crystallinity of When the high melting point resin (the core component when the heat-fusible fiber is a core-sheath type composite fiber) is a polypropylene resin (PP), the crystallinity is preferably 60% or less, more preferably from the viewpoint of texture. Is 50% or less, more preferably 45% or less, and from the viewpoint of hot air recovery, it is preferably 30% or more, more preferably 35% or more, and still more preferably 40% or more. When the high melting point resin (the core component when the heat-fusible fiber is a core-sheath type composite fiber) is polyethylene terephthalate (PET), the crystallinity is preferably 50% or less, more preferably from the viewpoint of texture. It is 40% or less, more preferably 30% or less, and from the viewpoint of hot air recovery, it is preferably 15% or more, more preferably 20% or more, and further preferably 25% or more. The crystallinity of the resin is determined by the following method.

<Measurement method of crystallinity of resin>
The crystallinity χ of the resin is obtained by the following formula (1).
χ = (1− (ρc−ρ) / (ρc−ρa)) × 100 (1)
The "ρc" in formula (1) is the density of the resin of the crystal, if the resin is ^{PP 0.936 [g / cm 3]} , in the case of ^{PET 1.457 [g / cm 3]} ( below Reference Reference 3).
Further, "ρa" in the formula (1) is the density of the amorphous resin, if the resin is ^{PP 0.850 [g / cm 3]} , in the case of PET 1.335 [g / cm ³ (See Reference 3 below).
Further, “ρ” in the equation (1) is obtained by the following equation (2).
[rho] = [rho] c-([rho] c- [rho] a) * (Lorentz density B-Lorentz density A) / (Lorentz density B-Lorentz density C) (2)

“Lorentz density A” in the formula (2) is obtained by the following formula (3). In addition, “n” in the following formula (3) is an average refractive index, and using the refractive index “np” in the parallel direction and the refractive index “nv” in the vertical direction of the measured value, the following formula (4 ).
Lorentz density A = (n ² −1) / (n ² +1) (3)
n ² = (np ² + 2nv ² ) / 3 (4)

The “Lorentz density B” in the formula (2) is obtained by substituting the refractive index of the crystal of each resin type into the formula (3), and in the case of PP, n = 1.52. In the case of PET, n = 1.64 (see the following Reference 2 and Reference 1 respectively) was used.
The “Lorentz density C” in the formula (2) is obtained by substituting the amorphous refractive index of each resin type into the formula (3), and in the case of PP, n = 1.47. In the case of PET, n = 1.58 (see the following Reference 2 and Reference 1 respectively) was used.

Reference 1: "Saturated polyester resin handbook" (Publisher: Nikkan Kogyo Shimbun, first edition, 1989)
・ Reference 2: “POLYMER HANDBOOK” (A WILEY-INTERSCIENCE PUBLICATION, 1999)
Reference 3: “Introduction to higher-order structural analysis of plastic molded products” (Editor, Plastic Molding Processing Society, First Edition, 2006)

  Note that the degree of crystallinity generally depends on the measurement method and conditions, and the structure regarded as a crystal is different. Therefore, it is general that the absolute value cannot be discussed between different measurement methods and conditions.

  The melting point of each resin component constituting the heat-fusible fiber was 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. The melting peak temperature of each resin is measured and defined by the melting peak temperature. Further, the temperature at which the resin component is fused to such an extent that the fiber fusion point strength can be measured is defined as the temperature at which the resin component molecules begin to flow. When the melting point of the resin component cannot be clearly measured by this method, the resin is defined as “resin having no melting point”. In this case, the softening point is used instead of the melting point.

  The form of the fiber assembly constituting the first fiber layer 11 is, for example, a web formed by a card method, a nonwoven fabric formed by a thermal fusion method, a nonwoven fabric formed by a hydroentanglement method, or a needle punch method. Nonwoven fabric formed by a solvent bonding method, nonwoven fabric formed by a spunbond method, nonwoven fabric formed by a melt blown method, or knitted fabric. The web formed by the card method is a fiber assembly in a state before being made into a nonwoven fabric. That is, a fiber assembly in which fibers are in an extremely loose entanglement state after being subjected to a post-treatment applied to a card web used for manufacturing a nonwoven fabric, for example, a heat-sealing treatment by an air-through method or a calendar method. It is the body. When the web formed by the card method is used for the first fiber layer 11, the first fiber layer 11 and the second fiber layer 12 are bonded together, or after being bonded, The fibers are bonded together by heat sealing or solvent, or mechanically entangled.

  The second fiber layer 12 is also composed of a fiber assembly. The 2nd fiber layer 12 contains the heat-shrinkable fiber which is a latent crimpable fiber crimped helically as a crimped fiber crimped helically. The latent crimpable fiber is a fiber that can be handled in the same manner as a conventional nonwoven fabric fiber before being heated, and has a property that a helical crimp is developed and contracted by heating at a shrinkage temperature. It is.

  The topsheet 1 of the present embodiment is formed by laminating the second fiber layer 12 made of 100% latent crimpable fiber and the first fiber layer 11 made of 100% heat-fusible fiber described above, and partially laying both together. After the bonding, the latent crimpable fibers in the second fiber layer 12 are thermally contracted to cause the second fiber layer 12 to be thermally contracted, so that a portion other than the fusion bonded portion 6 in the first fiber layer 11 is convex. It was obtained by raising it. By using latent crimpable fibers as the constituent fibers of the second fiber layer 12, both the heat shrinkability of the second fiber layer 12 and the second fiber layer 12 after heat shrinkage, and thus the elastomeric behavior of the topsheet 1 are both obtained. Can be expressed simultaneously.

  The latent crimpable fiber includes, for example, an eccentric core-sheath type composite fiber or a side-by-side type composite fiber containing two types of thermoplastic polymer materials having different shrinkage rates as components. Examples thereof include those described in JP-A-9-296325 and Japanese Patent No. 2759331. Examples of two types of thermoplastic polymer materials having different shrinkage rates include a combination of an ethylene-propylene random copolymer and polypropylene.

  The shrinkage temperature is the temperature between both softening points of a component having a relatively low softening point and a component having a relatively high softening point among a plurality of types of thermoplastic polymers possessed by latent crimpable fibers or crimped fibers. means. The shrinkage start temperature means a softening point of a component having a relatively low softening point. When the latent crimpable fiber is heated to a temperature between both softening points, only the component with the lower softening point starts to shrink. As a result, the entire fiber contracts in a helical manner to develop crimps, forming crimped fibers. The temperature of the heat treatment in the heat shrinking step described later can be appropriately adjusted according to the softening point of the resin constituting the latent crimpable fiber, that is, according to the shrinkage temperature.

  As a form of the fiber assembly constituting the second fiber layer 12, a web containing latent crimpable fibers and formed by a card method, a non-woven fabric formed by a thermal fusion method, a non-woven fabric formed by a hydroentanglement method Non-woven fabric formed by needle punch method, non-woven fabric formed by solvent bonding method, non-woven fabric formed by spunbond method, non-woven fabric formed by melt blown method, but web formed by card method Is preferred.

  The fiber assembly constituting the second fiber layer 12 is such that the constituent fibers in the portion not joined at the first fiber layer 11 and the fusion-bonding portion 6 are not thermally fused to each other. Is preferable from the viewpoint of improving the permeability of the viscous material.

  The first fiber layer 11 and the second fiber layer 12 may be mixed with fibers other than those described above, for example, water-absorbing fibers such as rayon, cotton, and hydrophilic acrylic fibers.

  For example, the second fiber layer 12 may be mixed with fibers other than latent crimpable fibers, such as heat-fusible fibers blended in the first fiber layer 11. The heat-fusible fiber is blended, for example, for the purpose of stabilizing the shape and improving the wrinkle / wrinkle resistance.

  In the topsheet 1, the second fiber layer 12 preferably contains 60% by mass or more, particularly 80% by mass or more, and 100% by mass or less of latent crimpable fibers. The content rate of the heat-shrinkable fiber referred to here is a content rate including both of those that exhibit spiral crimps and those that do not exhibit spiral crimps. By setting the content of the latent crimpable fiber to 80% by mass or more, a portion other than the fusion bonded portion 6 of the first fiber layer 11 can be sufficiently deformed into a convex shape to obtain a bulky surface sheet 1. it can.

  In the surface sheet 1, the first fiber layer 11 has a particularly sufficient portion that can be compressed and deformed when pressure from the skin is applied. From the viewpoint of improving the soft feeling, the first fiber layer 11 of the high convex portion 1 b. The thickness is preferably 0.6 mm or more, particularly 1 mm or more, and 7 mm or less, particularly 3 mm or less. Further, the thickness of the first fiber layer 11 of the low convex portion 1s is preferably 0.3 mm or more, particularly 0.5 mm or more, and 4.4 mm or less, particularly 1.5 mm or less. The second fiber layer 12 has a density higher than that of the first fiber layer 11 from the viewpoint of stably expressing excellent liquid drawability due to the density gradient between the first fiber layer 11 and the second fiber layer 12. It is preferably high and thin. Further, from the viewpoint of the texture and texture of the topsheet 1, the thickness of the second fiber layer 12 of the high convex portion 1b is 0.1 mm or more, particularly 0.2 mm or more, and 3.4 mm or less, particularly 1.5 mm or less. Preferably there is. Further, the thickness of the second fiber layer 12 of the low convex portion 1s is preferably 0.1 mm or more, particularly 0.2 mm or more, and 2.2 mm or less, particularly 1.0 mm or less.

The surface sheet 1 has a basis weight of 20 g / m ² or more, particularly 50 g / m ² or more, and 200 g / m ² or less, particularly 100 g / m ² from the viewpoint of bulkiness and softness when used in an absorbent article. It is preferably m ² or less. In the surface sheet 1, since the latent crimpable fiber is used for the second fiber layer 12, the basis weight in the nonwoven fabric state becomes larger than that in the web state by passing through a heat shrinking step described later. Therefore, unlike the case where no latent crimpable fiber is used, the topsheet 1 having a large basis weight can be easily obtained without taking a means such as laminating a plurality of webs. By having such a large basis weight, the comfort of the texture by improving the cushion feeling, the reduction of the amount of liquid attached to the skin by absorbing excretion without spreading on the top sheet, especially after absorbing menstrual blood The whiteness of the appearance can improve the sense of security and cleanliness. The basis weight is obtained by cutting the surface sheet 1 into a size of 50 mm × 50 mm or more, collecting a measurement piece, measuring the weight of the measurement piece using an electronic balance with a minimum display of 1 mg, and converting it to the basis weight. .

  In the topsheet 1, as shown in FIG. 6, when the high convex portion 1 b is cross-sectionally viewed in the thickness direction Z so as to pass through the top portion 1 bt, the hydrophilicity of the high convex portion top portion 1 bu on the top portion 1 bt side in the first fiber layer 11. The degree of hydrophilicity of the first fiber layer 11 is higher than the hydrophilicity of the high convex part bottom 1bd on the second fiber layer 12 side, and the hydrophilicity of the second fiber layer 12 is higher than the hydrophilicity of the high convex part top 1bu. Has been. Preferably, the size relationship of the hydrophilicity between the high convex portion top portion 1bu, the high convex portion bottom portion 1bd, and the second fiber layer 12 of the high convex portion 1b is such that the hydrophilicity of the second fiber layer 12> the high convex portion top portion. 1bu hydrophilicity> high convexity bottom 1bd hydrophilicity. If the topsheet 1 having such a configuration is used for a napkin 10 which is an example of an absorbent article, the liquid excreted during use is transferred to the top 1bt of the high convex portion 1b which is in contact with the wearer's skin. The liquid is difficult to remain on the surface. And the liquid drawn into the inside of the high convex part 1b is easy to transfer to the 2nd fiber layer 12, and the liquid once absorbed becomes difficult to return to the surface, and a usability | use_condition improves.

  Further, in the topsheet 1, as shown in FIG. 6, when the low convex portion 1s is viewed in the thickness direction Z so as to pass through the top portion 1st, the low convex portion top portion 1su on the top portion 1st side in the first fiber layer 11 is obtained. Of the first fiber layer 11 is higher than the hydrophilicity of the low convex portion bottom 1sd on the second fiber layer 12 side, and the hydrophilicity of the low convex portion top 1su is higher than the hydrophilicity of the high convex portion bottom 1bd. The hydrophilicity of the second fiber layer 12 is higher than the hydrophilicity of the low convex top 1su. Preferably, the magnitude relationship of the hydrophilicity between the low convex portion top portion 1su, the low convex portion bottom portion 1sd, the high convex portion top portion 1bu of the high convex portion 1b, and the second fiber layer 12 of the low convex portion 1s is The hydrophilicity of the two fiber layers 12> the hydrophilicity of the low convex top 1 su> the hydrophilicity of the low convex bottom 1 sd and the hydrophilicity of the high convex bottom 1 bd of the high convex 1 b. If the topsheet 1 having such a configuration is used for a napkin 10 which is an example of an absorbent article, the liquid excreted during use is transferred to the top 1bt of the high convex portion 1b which is in contact with the wearer's skin. The liquid is difficult to remain on the surface. And the liquid drawn into the inside of the high convex part 1b is easy to transfer to the 2nd fiber layer 12, and the liquid once absorbed is hard to return to the surface. In addition, even if a large amount of liquid is drawn into the high convex portion 1b, the action of drawing into the low convex portion 1s with high fiber density is easy to work, and the liquid once absorbed is difficult to return to the surface. A feeling improves.

  Regarding the high convex portion 1b and the low convex portion 1s described above, the hydrophilicity of the high convex portion top portion 1bu is the hydrophilicity at the top portion 1bt of the high convex portion 1b in the first fiber layer 11, and the low convex portion top portion. The hydrophilicity of 1 su is the hydrophilicity at the top portion 1st of the low convex portion 1s in the first fiber layer 11. The hydrophilicity of the high convex portion bottom 1bd is the hydrophilicity of the lowermost portion of the first fiber layer 11 (the portion opposite to the top 1bt of the high convex portion 1b) of the high convex portion 1b. The hydrophilicity of the convex bottom 1sd is the hydrophilicity of the lowermost part of the low convex part 1s in the first fiber layer 11 (part opposite to the top part 1st of the low convex part 1s). Further, the hydrophilicity of the second fiber layer 12 is the hydrophilicity at a portion showing the highest hydrophilicity when the hydrophilicity of the second fiber layer 12 is measured along the thickness direction Z. The hydrophilicity of the 2nd fiber layer 12 of the convex part 1b and the hydrophilicity of the 2nd fiber layer 12 of the low convex part 1s are the same. The “hydrophilicity” referred to in the present invention is determined based on the contact angle of the fiber measured by the method described below. Specifically, a low hydrophilicity is synonymous with a large contact angle, and a high hydrophilicity is synonymous with a small contact angle.

<Measurement method of contact angle>
Of the surface sheet 1 to be measured, a portion that crosses the top portion 1bt of the high convex portion 1b and the top portion 1st of the low convex portion 1s is cut vertically with a razor blade. The cut surface is observed with an optical microscope, the fiber is taken out from a predetermined portion in the thickness direction Z, and the contact angle of water with the fiber is measured. As a measuring device, an automatic contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. is used. Distilled water is used to measure the contact angle. The amount of liquid discharged from an ink jet type water droplet discharge part (manufactured by Cluster Technology, Inc., pulse injector CTC-25 having a discharge part pore diameter of 25 μm) is set to 20 picoliters, and a water drop is dropped directly above the fiber. And the state of dripping is recorded on the high-speed video recording apparatus connected to the camera installed horizontally. The recording device is preferably a personal computer incorporating a high-speed capture device from the viewpoint of image analysis later. In this measurement, an image is recorded every 17 msec. In the recorded video, the first image of water droplets on the fibers taken out from the top sheet 1 is attached to the attached software FAMAS (software version is 2.6.2, analysis method is droplet method, analysis method is θ / 2), image processing algorithm is non-reflective, image processing image mode is frame, threshold level is 200, and curvature correction is not performed.) Is calculated as the contact angle. The fiber taken out from the surface sheet 1 to be measured is cut into a fiber length of 1 mm, and the fiber is placed on a sample table of a contact angle meter and kept horizontal. Two different contact angles are measured for each fiber. N = 5 contact angles are measured to one decimal place, and a value obtained by averaging a total of 10 measured values (rounded to the second decimal place) is defined as the contact angle. Hereinafter, the “water contact angle” refers to the contact angle measured by this measurement method.

  In the topsheet 1, as described above, in the first fiber layer 11, the hydrophilicity of the high convex portion top portion 1bu is higher than the hydrophilicity of the high convex portion bottom portion 1bd, and the hydrophilicity of the low convex portion top portion 1su is low. It is higher than the hydrophilicity of the bottom 1sd. In order to provide such a gradient of hydrophilicity in the first fiber layer 11, it is preferable that the first fiber layer 11 includes a heat-fusible fiber to which a fiber treatment agent described later is attached. In this case, in the first fiber layer 11, the hydrophilicity gradually decreases from the high convex top 1bu to the high convex bottom 1bd or from the low convex top 1su to the low convex bottom 1sd. The hydrophilicity may be lowered stepwise. In particular, it is preferable that the hydrophilicity gradually decreases from the high convex top 1bu to the high convex bottom 1bd, and the hydrophilicity gradually decreases from the low convex top 1su to the low convex bottom 1sd. It is preferable. “Hydrophilicity gradually changes” means a boundary surface between which the hydrophilicity changes greatly between the high convex portion top portion 1bu and the high convex portion bottom portion 1bd, or between the low convex portion top portion 1su and the low convex portion bottom portion 1sd. Means that does not exist. By adopting this configuration, it becomes easier for body fluid to smoothly transition from the skin contact surface side to the non-skin contact surface side, thereby improving the feeling of use. Here, when the hydrophilicity is “gradually lower”, the hydrophilicity has gradation, and the hydrophilicity is from the high convex portion top 1bu toward the high convex portion bottom 1bd or from the low convex portion top 1su. It means a state where it is gradually lowered toward the low convex bottom 1sd.

  In the first fiber layer 11, the hydrophilicity gradually changes from the high convex portion top portion 1bu to the high convex portion bottom portion 1bd or from the low convex portion top portion 1su to the low convex portion bottom portion 1sd. It can be measured by the means. Of the first fiber layer 11, for example, the high convex portion 1 b is virtually divided into three equal parts in the thickness direction Z. Then, a total of four points of hydrophilicity are measured: one point on each of two imaginary lines that divide the high convex portion 1b into three equal parts, and the top portion 1bt of the high convex portion 1b and the lowermost portion of the high convex portion 1b. At this time, the case where the contact angles increase in order from the top 1bt of the first fiber layer 11 toward the bottom is referred to as “the hydrophilicity is gradually decreasing”. The same applies to the case of the low protrusion 1s.

  Regardless of whether the hydrophilicity gradually decreases or gradually decreases, in the first fiber layer 11, the water contact angle of the high convex portion top 1 bu is more than necessary for the first fiber layer 11. From the viewpoint of not retaining the liquid, it is preferably 65 ° or more, more preferably 70 ° or more, and further preferably 73 ° or more, and the viewpoint that the liquid is absorbed without flowing on the surface of the first fiber layer 11. Therefore, it is preferably 90 ° or less, more preferably 85 ° or less, and further preferably 75 ° or less. On the other hand, in the 1st fiber layer 11, from the viewpoint of suppressing the liquid return from the 2nd fiber layer 12, the contact angle of water of the high convex part bottom 1bd is preferably 75 ° or more, more preferably 80 °. Above, more preferably 85 ° or more, and preferably 90 ° or less, more preferably 88 ° or less, and still more preferably 86 ° or less, from the viewpoint of promptly transferring the liquid to the second fiber layer 12 during liquid absorption. It is.

  Moreover, regardless of whether the hydrophilicity is gradually lowered or gradually lowered, in the first fiber layer 11, the water contact angle of the low convex portion top portion 1su is within the high convex portion bottom portion 1bd. From the viewpoint that the liquid easily moves to the low convex portion 1 s, the angle is preferably 65 ° or more, more preferably 70 ° or more, still more preferably 73 ° or more, and the liquid flows on the surface of the first fiber layer 11. From the viewpoint of being absorbed, the angle is preferably 90 ° or less, more preferably 85 ° or less, and still more preferably 75 ° or less. On the other hand, in the first fiber layer 11, the water contact angle of the bottom portion 1sd of the low convex portion is preferably 75 ° or more, more preferably 80 °, from the viewpoint of suppressing liquid return from the second fiber layer 12. Above, more preferably 85 ° or more, and preferably 90 ° or less, more preferably 88 ° or less, and still more preferably 86 ° or less, from the viewpoint of promptly transferring the liquid to the second fiber layer 12 during liquid absorption. It is.

  The difference between the water contact angle at the high convex portion bottom 1bd and the water contact angle at the high convex top portion 1bu is preferably 1 ° or more, more preferably 5 ° or more, and still more preferably from the viewpoint of preventing liquid return. Is 7 ° or more, and preferably 20 ° or less, more preferably 18 ° or less, and still more preferably 15 ° or less, from the viewpoint of promptly transferring the liquid to the second fiber layer 12 during liquid absorption.

  From the same point of view, the ratio of the contact angle of water at the high convex top 1bu to the contact angle of water at the high convex bottom 1bd, that is, the value of the contact angle at the high convex bottom 1bd is used as the denominator. The ratio when the value of the contact angle at 1 bu is a molecule is preferably 0.7 or more, more preferably 0.75 or more, still more preferably 0.8 or more, and preferably 0.95 or less. More preferably, it is 0.9 or less, and still more preferably 0.85 or less.

  The difference between the contact angle of water at the bottom 1sd of the low protrusion and the contact angle of water at the top 1su of the low protrusion is preferably 1 ° or more, more preferably 5 ° or more, and still more preferably from the viewpoint of preventing liquid return. Is 7 ° or more, and preferably 20 ° or less, more preferably 18 ° or less, and still more preferably 15 ° or less, from the viewpoint of promptly transferring the liquid to the second fiber layer 12 during liquid absorption.

  From the same point of view, the ratio of the contact angle of water at the top of the low convex portion 1su to the contact angle of water at the bottom of the low convex portion 1sd, that is, the value of the contact angle of water at the bottom of the low convex portion 1sd is used as the denominator. The ratio when the contact angle value at the top part 1su is defined as a molecule is preferably 0.7 or more, more preferably 0.75 or more, still more preferably 0.8 or more, and preferably 0.8. It is 95 or less, More preferably, it is 0.9 or less, More preferably, it is 0.85 or less.

  The difference between the contact angle of water at the high convex bottom 1bd and the contact angle of water at the low convex top 1su is preferably 1 ° from the viewpoint that the liquid in the high convex bottom 1bd easily moves to the low convex 1s. From the viewpoint of quickly transferring the liquid to the second fiber layer 12 during liquid absorption, it is preferably 20 ° or less, more preferably 18 °. It is not more than °, more preferably not more than 15 °.

  From the same viewpoint, the ratio of the water contact angle at the low convex top 1 su to the water contact angle at the high convex bottom 1 bd, that is, the value of the water contact angle at the high convex bottom 1 bd is used as the denominator. The ratio of the contact angle of water at the top 1su as a molecule is preferably 0.7 or more, more preferably 0.75 or more, still more preferably 0.8 or more, and preferably 0.9 or less, more preferably 0.88 or less, still more preferably 0.85 or less.

  In contrast to the first fiber layer 11 having a gradient in hydrophilicity, in the topsheet 1, the second fiber layer 12 has substantially the same hydrophilicity in any part of the second fiber layer 12. Yes. From the viewpoint that the water contact angle of the second fiber layer 12 does not continue to be retained in the second fiber layer 12 on condition that the water contact angle of the high convex portion top portion 1bu and the low convex portion top portion 1su is smaller. , Preferably 50 ° or more, more preferably 55 ° or more, still more preferably 57 ° or more, and preferably 70 ° or less, more preferably 65 °, from the viewpoint of extracting the liquid from the first fiber layer 11. Hereinafter, it is more preferably 60 ° or less.

  The ratio of the contact angle of water in the second fiber layer 12 with respect to the contact angle of water in the portion having the smaller contact angle of water among the high protrusion top 1bu and the low protrusion top 1su, that is, the high protrusion top 1bu and The ratio when the contact angle of water at the portion having the smaller contact angle of water in the low convex portion top 1su is used as the denominator and the value of the contact angle of water in the second fiber layer 12 as the numerator is preferably 0. 65 or more, more preferably 0.7 or more, still more preferably 0.75 or more, and preferably 0.95 or less, more preferably 0.9 or less, still more preferably 0.85 or less.

  Further, the ratio of the contact angle of water in the second fiber layer 12 to the contact angle of water in the portion having the larger contact angle of water among the high protrusion top 1bu and the low protrusion top 1su, that is, the high protrusion top The ratio when the contact angle of water in the portion with the larger water contact angle of 1bu and the low convex top 1su is used as the denominator and the value of the contact angle of water in the second fiber layer 12 as the numerator is preferably 0.55 or more, more preferably 0.6 or more, further preferably 0.65 or more, and preferably 0.85 or less, more preferably 0.8 or less, still more preferably 0.75 or less. is there.

  In order to manufacture the surface sheet 1 composed of each layer and each part having the contact angle (relationship of hydrophilicity) as described above, a fiber treatment agent described later is used, and hot air blowing conditions in an air-through method described later, that is, What is necessary is just to control the temperature and air volume of hot air appropriately.

  Next, the fiber treatment agent used when manufacturing the surface sheet 1 will be described. The fiber treatment agent is attached to the surface of the constituent fiber of the surface sheet 1, and the hydrophilicity of the surface of the constituent fiber can be increased as compared with that before the fiber treatment agent is attached. In the surface sheet 1, as described above, the first fiber layer 11 and the second fiber layer 12 have different hydrophilicities, and this is mainly contained in the first fiber layer 11 and the second fiber layer 12. This is because the types of fiber treatment agents to be used are different. Hereinafter, the fiber treatment agent will be described for each fiber layer.

[Fiber treatment agent contained in the first fiber layer]
The fiber treatment agent attached to the heat-fusible fiber of the first fiber layer 11 is polyorganosiloxane (component (A)), alkyl phosphate ester (component (B)), and the following general formula (1). The anionic surfactant represented or the polyoxyalkylene modified polyhydric alcohol fatty acid ester (component (C)) is contained. As the component (C), one or more selected from the group consisting of an anionic surfactant represented by the following general formula (1) and a polyoxyalkylene-modified polyhydric alcohol fatty acid ester can be used. In addition, (C) component points out the component which does not contain the alkyl phosphate ester which is (B) component.

（式中、Ｚはエステル基、アミド基、アミン基、ポリオキシアルキレン基、エーテル基若しくは２重結合を含んでいてもよい、炭素数１〜１２の直鎖又は分岐鎖のアルキル鎖を表わし、Ｒ₁及びＲ₂はそれぞれ独立に、エステル基、アミド基、ポリオキシアルキレン基、エーテル基若しくは２重結合を含んでいてもよい、炭素数２〜１６の直鎖又は分岐鎖のアルキル基を表わし、Ｘは―ＳＯ₃Ｍ、―ＯＳＯ₃Ｍ又は―ＣＯＯＭを表わし、ＭはＨ、Ｎａ、Ｋ、Ｍｇ、Ｃａ又はアンモニウムを表わす。）

(In the formula, Z represents an ester group, an amide group, an amine group, a polyoxyalkylene group, an ether group or a linear or branched alkyl chain having 1 to 12 carbon atoms, which may contain a double bond; R ₁ and R ₂ each independently represents an ester group, an amide group, a polyoxyalkylene group, an ether group or a linear or branched alkyl group having 2 to 16 carbon atoms, which may contain a double bond. , X represents —SO ₃ M, —OSO ₃ M or —COOM, and M represents H, Na, K, Mg, Ca or ammonium.)

  The fiber to which the fiber treatment agent containing the three components (A) to (C) is attached is subjected to a heat treatment at a temperature equal to or higher than the softening point of the resin constituting the fiber surface, thereby producing a polyorganosiloxane (component (A). ) Promotes the penetration of an anionic surfactant having an alkyl chain (component (C)) into the fiber. Therefore, the hydrophilicity of the fiber surface changes to a low value by heat treatment. This is because the polyorganosiloxane promotes the penetration of an anionic surfactant having two or more alkyl chains into the fiber, and the hydrophilicity of the fiber surface is likely to be lowered by heat treatment. This is because the polysiloxane chain of the polyorganosiloxane and the alkyl chain of the anionic surfactant are incompatible with each other, so that when the fiber is melted by heating, the anionic surfactant penetrates into the more easily adaptable fiber. Presumed to happen.

  Among the components (C), the anionic surfactant represented by the general formula (1) has two or more alkyl chains, the alkyl groups are bulky, and enclose the hydrophilic groups so that the inside of the fiber When this is used, the penetration into the fiber tends to be facilitated by the presence of the polyorganosiloxane.

  In addition, among the components (C), the polyoxyalkylene-modified polyhydric alcohol fatty acid ester has a structure in which hydrophobic chains are easily arranged radially and easily surround a hydrophilic group. In comparison with the case where a surfactant having a normal linear hydrocarbon chain is used, the presence of polyorganosiloxane facilitates the penetration into the fiber.

  Thereby, for example, in the hydrophilicity lowering step of blowing hot air to the web, which is one step of the manufacturing process of the surface sheet 1 described later, the amount of heat received by the fibers in the web is the hot air blowing surface and the opposite surface (net surface). Therefore, the amount of heat received is different between the fiber on the hot air blowing surface and the fiber on the opposite side, and the fiber contact between the fiber on the hot air blowing surface and the fiber on the opposite side is different. The value of the corner will also change. By utilizing this fact, it is possible to manufacture a nonwoven fabric having a gradient in hydrophilicity from one surface side of the nonwoven fabric to the other surface side opposite thereto. Hereinafter, the three components (A) to (C) will be described.

[Polyorganosiloxane (component (A))]
As the polyorganosiloxane that is one of the essential components of the fiber treatment agent contained in the first fiber layer, any of a linear one and a cross-linked two-dimensional or three-dimensional network structure can be used. It is a straight chain.

  Specific examples of polyorganosiloxanes suitable for the present invention are alkylalkoxysilanes, arylalkoxysilanes, alkylhalosiloxane polymers or cyclic siloxanes, and the alkoxy groups are typically methoxy groups. As the alkyl group, an alkyl group which may have a side chain having 1 to 18 carbon atoms, preferably 1 to 8 carbon atoms, particularly 1 to 4 carbon atoms is suitable. Examples of the aryl group include a phenyl group, an alkylphenyl group, and an alkoxyphenyl group. Instead of an alkyl group or an aryl group, a cyclic hydrocarbon group such as a cyclohexyl group or a cyclopentyl group, or an aralkyl group such as a benzyl group may be used. The polyorganosiloxane referred to in the present invention is a concept that does not include a polyorganosiloxane modified with a highly hydrophilic polyoxyethylene (POE) chain from the viewpoint of increasing the contact angle of the fiber surface by heating. .

  Preferred most typical polyorganosiloxanes include polydimethylsiloxane, polydiethylsiloxane, polydipropylsiloxane and the like, with polydimethylsiloxane being particularly preferred.

  The molecular weight of the polyorganosiloxane is preferably a high molecular weight. Specifically, the weight average molecular weight is preferably 100,000 or more, more preferably 150,000 or more, further preferably 200,000 or more, preferably Is 1 million or less, more preferably 800,000 or less, and still more preferably 600,000 or less. Further, as the polyorganosiloxane, two or more kinds of polyorganosiloxanes having different molecular weights may be used. When two or more kinds of polyorganosiloxanes having different molecular weights are used, one of them has a weight average molecular weight of preferably 100,000 or more, more preferably 150,000 or more, further preferably 200,000 or more, and preferably Is not more than 1 million, more preferably not more than 800,000, still more preferably not more than 600,000, and the other one has a weight average molecular weight of preferably less than 100,000, more preferably not more than 50,000, more preferably 30,000. It is 5,000 or less, more preferably 20,000 or less, preferably 2000 or more, more preferably 3000 or more, and still more preferably 5000 or more. Further, a preferable blending ratio (the former: latter) of the polyorganosiloxane having a weight average molecular weight of 100,000 or more and the polyorganosiloxane having a weight average molecular weight of less than 100,000 is a mass ratio, preferably 1:10 to 4: 1. More preferably, it is 1: 5 to 2: 1.

The weight average molecular weight of the polyorganosiloxane is measured using GPC. The measurement conditions are as follows. The calculated molecular weight is calculated with polystyrene.
Separation column: GMHHR-H + GMHHR-H (cation)
Eluent: L Farmin DM20 / CHCl ₃
Solvent flow rate: 1.0 ml / min
Separation column temperature: 40 ° C

  The content of the polyorganosiloxane in the fiber treatment agent is preferably 1% by mass or more, preferably 5% by mass or more, based on the total mass of the fiber treatment agent, from the viewpoint of increasing the change in hydrophilicity due to heat treatment. More preferably it is. Further, the content of the polyorganosiloxane in the fiber treatment agent is preferably 30% by mass or less, more preferably 20% by mass or less, based on the total mass of the fiber treatment agent, from the viewpoint of easily absorbing the liquid on the nonwoven fabric surface. . For example, the content of the polyorganosiloxane in the fiber treatment agent is preferably 1% by mass to 30% by mass, and preferably 5% by mass to 20% by mass with respect to the total mass of the fiber treatment agent. Further preferred.

  A commercially available product can also be used as the polyorganosiloxane. For example, “KF-96H-1 million Cs” manufactured by Shin-Etsu Silicone Co., “SH200 Fluid 1000000 Cs” manufactured by Toray Dow Corning Co., Ltd. and those containing two types of polyorganosiloxane include “ KM-903 "or" BY22-060 "manufactured by Toray Dow Corning Co. can be used.

[Alkyl phosphate ester (component (B))]
The alkyl phosphate ester, which is one of the essential components of the fiber treatment agent contained in the first fiber layer 11, improves the properties of the raw cotton through the card machine and the uniformity of the web, thereby improving the productivity of the nonwoven fabric. It is a kind of anionic surfactant that is added to the fiber treatment agent for the purpose of improvement and prevention of quality deterioration. Specific examples of the alkyl phosphate ester include those having a saturated carbon chain such as stearyl phosphate ester, myristyl phosphate ester, lauryl phosphate ester, palmityl phosphate ester, oleyl phosphate ester, palmitoleyl phosphate ester, etc. Examples include unsaturated carbon chains and those having side chains in these carbon chains. More preferably, it is a completely neutralized or partially neutralized salt of a mono- or dialkyl phosphate ester having 16 to 18 carbon chains. Examples of the alkyl phosphate ester salt include alkali metals such as sodium and potassium, ammonia, and various amines. Alkyl phosphate ester can be used individually by 1 type or in mixture of 2 or more types.

  The content of the alkyl phosphate ester in the fiber treatment agent is preferably 5% by mass or more, more preferably 10% by mass with respect to the total mass of the fiber treatment agent from the viewpoint of card machine passability and web uniformity. %, And from the viewpoint of not hindering the hydrophobization of the fiber by the polyorganosiloxane resulting from the heat treatment, it is preferably 30% by mass or less, more preferably 25% by mass with respect to the total mass of the fiber treatment agent. % Or less.

[Anionic surfactant represented by the general formula (1) (component (C))]
Examples of the anionic surfactant in which X in the general formula (1) is —SO ₃ M, that is, the hydrophilic group is a sulfonic acid or a salt thereof, include a dialkylsulfonic acid or a salt thereof. Specific examples of the dialkyl sulfonic acid include dioctadecyl sulfosuccinic acid, didecyl sulfosuccinic acid, ditridecyl sulfosuccinic acid, di-2-ethylhexyl sulfosuccinic acid, etc. Saturated fatty acids and unsaturated fatty acids such as 2-sulfotetradecanoic acid 1-ethyl ester (or amide) sodium salt and 2-sulfohexadecanoic acid 1-ethyl ester (or amide) sodium salt Alpha sulfo fatty acid alkyl esters (or amides) sulfonated at the α-position of esters (or amides), dialkyl alkenes obtained by sulfonating internal olefins of hydrocarbon chains and unsaturated fatty acids And the like can be mentioned acid. The number of carbon atoms in each of the two-chain alkyl groups of the dialkyl sulfonic acid is preferably 4 or more and 14 or less, particularly 6 or more and 10 or less.

  Specific examples of the anionic surfactant in which the hydrophilic group is sulfonic acid or a salt thereof include the following anionic surfactants.

Examples of the anionic surfactant in which X in the general formula (1) is —OSO ₃ M, that is, the hydrophilic group is sulfuric acid or a salt thereof, include dialkyl sulfates. Compounds having a branched chain alcohol such as ethyl hexyl sulfate sodium salt and 2-hexyl decyl sulfate sodium salt, and branched chains such as polyoxyethylene 2-hexyldecyl sulfate and polyoxyethylene 2-hexyldecyl sulfate Compounds such as those in which a POE chain is introduced between an alcohol and a sulfate group, and hydroxy fatty acid esters such as 12-sulfate stearic acid 1-methyl ester (or amide) 3-sulfate hexanoic acid 1-methyl ester (or amide) ( Or a compound obtained by sulfating amide).

  More specific examples of the anionic surfactant in which the hydrophilic group is sulfuric acid or a salt thereof include the following anionic surfactants.

  Examples of the anionic surfactant in which X in the general formula (1) is —COOM, that is, the hydrophilic group is a carboxylic acid or a salt thereof, include dialkyl carboxylic acids. Specific examples thereof include 11-ethoxy. Hydroxy fatty acids such as heptadecane carboxylic acid sodium salt and 2-ethoxypentacarboxylic acid sodium salt that are alkoxylated with a hydroxy moiety, and the fatty acid moiety is sodiumated, and hydroxy amino acids such as sarcosine and glycine Examples thereof include a compound obtained by reacting chloride to sodiumize the carboxylic acid in the amino acid portion, and a compound obtained by reacting fatty acid chloride with the amino group of arginic acid.

  Specific examples of the anionic surfactant in which the hydrophilic group is a carboxylic acid or a salt thereof include the following anionic surfactants.

  The content of the anionic surfactant (component (C)) represented by the general formula (1) in the fiber treatment agent is based on the total mass of the fiber treatment agent from the viewpoint of increasing the change in hydrophilicity due to heat treatment. Preferably, it is 1% by mass or more, more preferably 5% by mass or more, and if the hydrophilicity is too high, the liquid treatment agent tends to be held, and the dryness is impaired. , Preferably 20% by mass or less, more preferably 13% by mass or less. The content of the anionic surfactant (component (C)) represented by the general formula (1) is preferably 1% by mass or more and 20% by mass or less, more preferably 5% by mass or more and 13% by mass. % Or less.

[Polyoxyalkylene-modified polyhydric alcohol fatty acid ester (component (C))]
The polyoxyalkylene-modified polyhydric alcohol fatty acid ester that is one of the essential components of the fiber treatment agent contained in the first fiber layer 11 makes the decrease in hydrophilicity due to heat treatment during the production of the nonwoven fabric more remarkable, For the purpose of significantly reducing the hydrophilicity of a desired portion in the nonwoven fabric, it is blended into the fiber treatment agent and is a kind of nonionic surfactant. The polyoxyalkylene-modified polyhydric alcohol fatty acid ester is a kind of polyhydric alcohol fatty acid ester obtained by esterifying a hydroxyl group of a polyhydric alcohol with a fatty acid, and is a modified product obtained by adding an alkylene oxide to the polyhydric alcohol fatty acid ester. The polyoxyalkylene-modified polyhydric alcohol fatty acid ester can be produced according to a conventional method, and can be produced, for example, according to Japanese Patent Application Laid-Open No. 2007-91852.

  Examples of the polyhydric alcohol that is one of the raw materials of the polyoxyalkylene-modified polyhydric alcohol fatty acid ester (or polyhydric alcohol fatty acid ester) include, for example, ethylene glycol, diethylene glycol, polyethylene glycol (molecular weight 200 to 11000), propylene glycol, di Propylene glycol, polypropylene glycol (molecular weight 250-4000), 1,3-butylene glycol, glycerin, polyglycerin (degree of polymerization 2-30), erythritol, xylitol, sorbitol, mannitol, inositol, sorbitan, sorbide, sucrose, trehalose, Examples include erulose, lactosucrose, cyclodextrin, maltitol, lactitol, palatinit, panitol, and reduced starch syrup. Preferred are polyethylene glycol, glycerin, erythritol, sorbitol, sorbitan, sorbide, and sucrose, and particularly preferred are sorbitol, sorbitan, and sorbide.

  Examples of the fatty acid that is another raw material of the polyoxyalkylene-modified polyhydric alcohol fatty acid ester (or polyhydric alcohol fatty acid ester) include, for example, saturated or unsaturated fatty acids having 6 to 22 carbon atoms, and these as the main components. Mixed fatty acids or branched chain fatty acids having 8 to 36 carbon atoms. The fatty acid may partially contain a hydroxyl group. Specifically, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, cis-9-octadecenoic acid, eicosanoic acid, docosanoic acid, tetracosanoic acid, hexacosanoic acid, octacosanoic acid , 2-ethylhexylic acid, isostearic acid, and the like, and coconut oil fatty acid and beef tallow fatty acid which are naturally derived mixed fatty acids may be used, preferably fatty acids having 8 to 18 carbon atoms, particularly preferably dodecanoic acid, octadecane. Acid, cis-9-octadecenoic acid.

  The main component of the polyhydric alcohol fatty acid ester constituting the polyoxyalkylene-modified polyhydric alcohol fatty acid ester is not to increase the shape of the molecule linearly when the hydrophobic chain is enlarged and the hydrophobicity is increased. From the viewpoint of increasing the dimension dimensionally, it is preferable to use a trivalent or higher alcohol esterified product with an alcohol component esterification rate of 90% or higher from the viewpoint of obtaining a shape that can be easily taken into the fiber. Here, the main component is the most abundant component in the polyhydric alcohol fatty acid ester, and is preferably contained in an amount of 50% by mass or more based on the total mass of the polyhydric alcohol fatty acid ester. For example, examples of the trivalent alcohol include glycerin, examples of the tetravalent alcohol include erythritol, and examples of the pentavalent alcohol include xylitol.

  Particularly preferred as the polyhydric alcohol fatty acid ester constituting the polyoxyalkylene-modified polyhydric alcohol fatty acid ester is castor oil (hardened castor oil). Castor oil is a glycerin fatty acid ester derived from the seeds of castor, which is a plant belonging to the family Dromeliaceae, and about 90% of the constituent fatty acid is ricinoleic acid. That is, the polyoxyalkylene-modified polyhydric alcohol fatty acid ester is preferably an ester oil of glycerin and a fatty acid mainly composed of ricinoleic acid.

  In the polyoxyalkylene-modified polyhydric alcohol fatty acid ester, examples of the alkylene oxide added to the polyhydric alcohol fatty acid ester include ethylene oxide, propylene oxide, butylene oxide, and the like. Particularly preferred as the polyoxyalkylene-modified polyhydric alcohol fatty acid ester is a polyoxyethylene (POE) -modified polyhydric alcohol fatty acid ester in which the alkylene oxide added to the polyhydric alcohol fatty acid ester is ethylene oxide, and particularly preferred are Polyhydric alcohol fatty acid ester is POE-modified castor oil (POE-modified hardened castor oil), which is castor oil (hardened castor oil).

  In polyoxyalkylene-modified polyhydric alcohol fatty acid esters, the number of moles of alkylene oxide added to polyhydric alcohol fatty acid esters improves the liquid absorption performance of the laminated nonwoven fabric (first fiber layer) (reduced liquid amount and liquid flow amount). Etc.) is preferably more than 20 moles, particularly preferably 40 moles or more. However, if the number of added moles of alkylene oxide is too large, the hydrophilicity of the laminated nonwoven fabric will increase too much, and, for example, when the laminated nonwoven fabric is used as a surface sheet in an absorbent article, there is a risk of increasing the amount of liquid remaining. Therefore, the added mole number is preferably 80 moles or less, more preferably 60 moles or less.

  The content of the polyoxyalkylene-modified polyhydric alcohol fatty acid ester (component (C)) in the fiber treatment agent increases the hydrophilicity of the topsheet 1 (first fiber layer 11), and the hydrophilicity due to heat treatment during the production of the nonwoven fabric. From the viewpoint of remarkably exhibiting the effect of lowering the property, it is preferably 5% by mass or more, more preferably 10% by mass or more, and more preferably 10% by mass or more of the remaining amount of liquid due to strong hydrophilization. From the viewpoint of suppressing the increase, the amount is preferably 20% by mass or less, more preferably 15% by mass or less, with respect to the total mass of the fiber treatment agent.

  In addition, unless otherwise indicated, the “fiber treatment agent” used as a reference for the content of the fiber treatment agent-containing component, such as the components (A) to (C), is a “fiber treatment agent attached to the nonwoven fabric”. It is not a fiber treatment agent before being attached to the nonwoven fabric. When the fiber treatment agent is attached to the nonwoven fabric, the fiber treatment agent is usually diluted with an appropriate solvent such as water, so the content of the fiber treatment agent-containing component, for example, the component (A) in the fiber treatment agent The content can be based on the total mass of the diluted fiber treatment agent.

  Moreover, when analyzing the adhering fiber treatment agent in the nonwoven fabric adhering to the fiber treatment agent such as the surface sheet 1, it is preferable to analyze according to the following procedure. First, the nonwoven fabric to be analyzed is washed with a suitable solvent. Examples of the cleaning solvent include a mixed solvent of ethanol and methanol and a mixed solvent of ethanol and water. When the nonwoven fabric to be analyzed is a sanitary product or a surface sheet of an absorbent article such as a disposable diaper for children or adults, an adhesive used for joining the surface sheet to another member in the absorbent article After being melt-softened by heating with a heating means such as a dryer, the top sheet is peeled off, and the peeled top sheet is washed with a cleaning solvent. Next, the solvent used for washing the non-woven fabric to be analyzed (cleaning solvent containing the fiber treatment agent) is dried, and the residue is quantified so that the total amount of the fiber treatment agent adhering to the nonwoven fabric is obtained. It can be measured. In addition, after selecting an appropriate column and solvent according to the composition of the residue, each component is fractionated by high performance liquid chromatography, and each fraction is further subjected to MS measurement, NMR measurement, elemental analysis, etc. By performing the above, the structure of each fraction can be identified. When the fiber treatment agent contains a polymer compound, it becomes easier to identify the constituent components by using a technique such as gel permeation chromatography (GPC) together.

  In the fiber treatment agent contained in the first fiber layer 11, the content ratio of the polyorganosiloxane as the component (A) and the anionic surfactant represented by the general formula (1) as the component (C) (the former: the latter) ) Is, by mass ratio, preferably 1: 3 to 4: 1, more preferably 1: 2 to 3: 1.

  Further, in the fiber treatment agent contained in the first fiber layer 11, the content ratio (the former: the latter) of the polyorganosiloxane of the component (A) and the polyoxyalkylene-modified polyhydric alcohol fatty acid ester of the component (C) is: The mass ratio is preferably 1: 2 to 3: 1, more preferably 1: 1 to 2: 1.

  In the fiber treatment agent contained in the first fiber layer 11, the content ratio (the former: latter) of the polyorganosiloxane (A) and the alkyl phosphate ester (B) is preferably a mass ratio. Is 1: 5 to 10: 1, more preferably 1: 2 to 3: 1.

[Other ingredients]
The fiber treatment agent contained in the first fiber layer 11 may contain other components in addition to the components (A) to (C) described above. Examples of other components to be blended in addition to the components (A) to (C) include treatment agents such as anti-sticking agents such as modified silicone. As other components, anionic, cationic, amphoteric and nonionic surfactants (surfactants other than the components (B) and (C)) can be used.

  The heat-fusible fiber contained in the first fiber layer 11 has a higher degree of hydrophilicity on the surface of the fiber than before the fiber treatment agent is adhered, as compared to before the adhesion. From the viewpoint of increasing the hydrophilicity of the fiber, the adhesion amount of the fiber treatment agent is preferably 0.1% by mass or more, more preferably 0.2% by mass with respect to the total mass of the heat-fusible fiber excluding the fiber treatment agent. % Or more and 1.5% by mass or less, more preferably 1.0% by mass or less.

The amount of the fiber treatment agent attached to the fibers (fiber treatment agent adhesion rate) can be measured by the following method. First, 1 kg of fiber is accurately weighed to the third decimal place with an electronic balance (W1). The fiber is then washed with room temperature water for 20 minutes, followed by 2 minutes with 50 ° C. water. These washings with water are repeated three times, then immersed in ethanol and washed with 40 KHz ultrasonic waves. The ultrasonic cleaning is performed for 30 minutes, and this is repeated three times. After washing, the fiber is left to dry for one day and the weight is measured (W2). The fiber treatment agent adhesion rate is calculated by the following formula.
Fiber treatment agent adhesion rate (mass%) = {(W1-W2) / W1} × 100

  As a method for attaching the fiber treatment agent to the surface of the heat-fusible fiber, 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 treatment before the hydrophilicity lowering step described later. The fiber having the fiber treatment agent attached to the surface thereof is dried at a temperature sufficiently lower than the melting point of the polyethylene resin (for example, 110 ° C. or less) by, for example, a hot air blowing dryer.

[Fiber treatment agent contained in the second fiber layer 12]
As described above, the second fiber layer 12 has a higher hydrophilicity than any part of the first fiber layer 11, and the hydrophilicity of the second fiber layer 12 is the same in any part. ing. Examples of the fiber treatment agent contained in the second fiber layer 12 include fiber treatment agents called oil agents that have been conventionally used to impart hydrophilicity to the fibers, such as anionic, cationic, amphoteric, and nonions. Various surfactants having various molecular weights can be used alone or in combination of two or more. In addition, it is preferable that the constituent fiber of the 2nd fiber layer 12 is not processed by the specific fiber processing agent containing the above-mentioned (A) component thru | or (C) component.

  Examples of anionic surfactants include alkyl phosphate sodium salt, alkyl ether phosphate sodium salt, dialkyl phosphate sodium salt, dialkyl sulfosuccinate sodium salt, alkylbenzene sulfonate sodium salt, alkyl sulfonate sodium salt, alkyl sulfate sodium salt, secondary alkyl sulfate Examples thereof include sodium salts (all alkyls preferably have 6 to 22 carbon atoms, particularly preferably 8 to 22 carbon atoms). These may use other alkali metal salts such as potassium salts in place of sodium salts.

  Examples of the cationic surfactant include alkyl (or alkenyl) trimethyl ammonium halide, dialkyl (or alkenyl) dimethyl ammonium halide, alkyl (or alkenyl) pyridinium halide, and these compounds have 6 to 18 carbon atoms. Those having an alkyl group or an alkenyl group are preferred. Examples of the halogen in the halide compound include chlorine and bromine.

  Examples of amphoteric surfactants include alkyl (C1-30) dimethylbetaine, alkyl (C1-30) amidoalkyl (C1-4) dimethylbetaine, alkyl (C1-30) dihydroxyalkyl. (C1-C30) Betaine-type amphoteric surfactants such as betaine and sulfobetaine-type amphoteric surfactants, alanine-type [alkyl (C1-C30) aminopropionic acid type, alkyl (C1-C30 ) Iminodipropionic acid type etc.] Amphoteric surfactant, glycine type such as alkyl betaine [alkyl (carbon number 1-30) aminoacetic acid type etc.] Amino acid type amphoteric surfactant such as amphoteric surfactant, alkyl (carbon number) 1-30) Aminosulfonic acid type amphoteric surfactants such as taurine type.

  Examples of nonionic surfactants include polyhydric alcohol fatty acid esters such as glycerin fatty acid esters, poly (preferably n = 2 to 10) glycerin fatty acid esters, sorbitan fatty acid esters (all preferably 8 to 60 carbon atoms of fatty acids). , Alkylene oxide adducts of polyhydric alcohol fatty acid esters (preferably 2 to 60 moles added), polyoxyalkylene (2 to 60 moles added) alkyl (8 to 22 carbon atoms) amide, polyoxyalkylene (addition) Mole number 2-60) alkyl (C8-C22) ether, polyoxyalkylene modified silicone, amino modified silicone, etc. are mentioned.

  Particularly preferred as the fiber treatment agent contained in the second fiber layer 12 is a nonionic surfactant. When a large amount of nonionic surfactant is blended in the second fiber layer 12, effects such as improved adhesion stability to the fiber surface and suppression of functional deterioration due to pseudo-bonding between the surfactant molecules can be obtained. In particular, a nonionic surfactant having a high molecular weight is more preferable from the viewpoint of obtaining hydrophilic durability. Further, as a means for facilitating the fixation of the fiber treating agent on the fiber surface, it is also preferable from the viewpoint of enhancing the hydrophilic durability in addition to the surfactant, such as a fixing agent or kneading. A treatment agent such as an anti-sticking agent such as modified silicone may be added to the fiber treatment agent contained in the second fiber layer 12. In the second fiber layer 12, the amount of the fiber treatment agent attached to the fibers and the means for the attachment can be the same as the treatment with the fiber treatment agent for the heat-fusible fibers contained in the first fiber layer 11.

[Production method of surface sheet 1]
The surface sheet 1 for absorbent articles is a laminated nonwoven fabric, and more specifically, heat-fusibility to which the fiber treatment agent containing the component (A), the component (B) and the component (C) is attached. It is a laminated nonwoven fabric having a first fiber layer 11 having fibers and a second fiber layer 12 laminated on one side of the first fiber layer 11. The manufacturing method of the surface sheet 1 includes a step of partially bonding the first fiber layer 11 and the second fiber layer 12 to form a laminate, and a melting point of the heat-fusible fiber of the first fiber layer 11 or higher. A hydrophilicity lowering step of reducing the hydrophilicity of the first fiber layer 11 by heat treatment at a temperature.

  FIG. 12 shows a manufacturing apparatus suitably used for manufacturing the topsheet 1. The manufacturing apparatus 100 shown in the figure includes a first web manufacturing unit 110, a second web manufacturing unit 120, a first heating unit 130, an embossing unit 140, and a second heating unit 150.

  Both the first web manufacturing unit 110 and the second web manufacturing unit 120 are constituted by a card machine, and perform a card process. The 1st web manufacture part 110 is a site | part which manufactures the web corresponding to the 1st fiber layer 11 in the target laminated nonwoven fabric (air through nonwoven fabric). On the other hand, the second web production unit 120 is a part for producing a web corresponding to the second fiber layer 12 in the target topsheet 1. The first web production unit 110 and the second web production unit 120 are supplied with appropriate raw material fibers according to the specific application of the target surface sheet, and the first web 111 and the second web 121 are produced. . An appropriate amount of fiber treatment agent is attached to the raw fiber depending on the specific use of the target laminated nonwoven fabric.

  The first web 111 fed out from the first web production unit 110 in the direction indicated by MD in the drawing is conveyed to the first heating unit 130 and subjected to a hydrophilicity reduction step. In the hydrophilicity lowering step, the first web 111 is subjected to a hot air blowing process in the first heating unit 130, thereby causing heat fusion between the fibers constituting the first web 111 to become the first nonwoven fabric 112. .

  The first heating unit 130 has a sealed chamber 131. A circulating endless belt (not shown) is disposed in the chamber 131. The endless belt in the chamber 131 is made of a breathable material such as a mesh belt made of metal wire or resin. The first web 111 is placed and conveyed on an endless belt in the chamber 131. Here, in the first web 111, a surface facing the endless belt in the chamber 131 is referred to as a first surface 1S, and a surface located on the opposite side to the first surface 111a is referred to as a second surface 2S. Inside the chamber 131, there is provided a blow-out port (not shown) for air heated to a temperature higher than the melting point of the heat-fusible fiber constituting the first web 111 (hereinafter also referred to as “hot air”). . Furthermore, a suction port (not shown) for blowing hot air is also provided in the chamber 131. While the first web 111 conveyed into the chamber 131 passes through the chamber 131, hot air HW is blown against the first web 111 in an air-through manner. The hot air HW is blown from the second surface 2S side of the first web 111. The hot air HW blown is discharged from the first surface 1S side of the first web 111. For this purpose, the outlet (not shown) is arranged to face the second surface 2S of the first web 111, and the suction port (not shown) is the first surface. It is arranged to face 1S.

  As described above, in the heat-fusible fiber to which the fiber treatment agent containing the components (A) to (C) is attached, the fiber of the fiber treatment agent according to the amount of heat received by the heat-fusible fiber. The degree of penetration into the interior differs, and the greater the amount of heat, the greater the extent of penetration of the fiber treatment agent into the fiber. And as the degree of penetration of the fiber treatment agent increases, the hydrophilicity of the fiber decreases compared to the initial state where the fiber treatment agent is adhered. In the manufacturing method of the present embodiment, by utilizing this phenomenon, a hydrophilicity gradient is generated in the target laminated nonwoven fabric (first nonwoven fabric corresponding to the first fiber layer), and the first surface from the second surface side. A surface sheet having a gradient so as to increase the hydrophilicity toward the side is obtained.

  Specifically, according to the air-through method, the fiber present on the second surface 2S, which is the hot air blowing surface of the first web 111, receives the largest amount of heat and is opposite to the hot air blowing surface, that is, the endless in the chamber 131. The fibers present on the first surface 1S, which is the surface facing the belt, receive the smallest amount of heat. Therefore, in the 1st heating part 130 of this manufacturing method, the fiber which exists in the surface of the 2nd surface 2S of the 1st web 111 receives the largest calorie | heat amount, and the fiber which exists in the surface of the 1st surface 1S has the least calorie | heat amount. receive. As a result, in the first nonwoven fabric 112 obtained by performing the hot air blowing process on the first web 111, the second surface 2S side receiving the largest amount of heat has the largest degree of penetration of the fiber treatment agent, and the smallest amount of heat. The degree of penetration of the fiber treatment agent is the smallest on the first surface 1S side that has received the light, and the degree of penetration of the fiber treatment agent into the fibers increases from the first surface 1S side to the second surface 2S side. Accordingly, in the first nonwoven fabric 112, the first surface 1S side is a highly hydrophilic portion HP having a relatively high hydrophilicity, and the second surface 2S side is a low hydrophilic portion LP having a relatively low hydrophilicity.

  The first nonwoven fabric 112 is further laminated with the second web 121 as will be described later, and after being subjected to an embossing process at the embossing part 140, it is subjected to a heat shrinking process at the second heating part 150. In the 2nd heating part 150, it is set so that the fiber which exists in the surface of the 1st surface of the 2nd web 121 may receive the largest calorie | heat amount, and the fiber which exists in the low hydrophilic part LP also in the 1st nonwoven fabric 112 This receives a larger amount of heat than the fiber present in the highly hydrophilic part HP. Therefore, the 1st nonwoven fabric 112 after passing through a heat shrink process has a larger hydrophilicity gradient than the 1st nonwoven fabric 112 immediately after passing through a hydrophilicity fall process.

In the hydrophilicity lowering step, the temperature of the heat treatment is such that the hydrophilicity gradient is generated in the first web 111 or the first nonwoven fabric 112, and the heat-fusible fibers constituting the first web 111 are fused. From the viewpoint of raising and securing the strength of the first nonwoven fabric 112, it is preferably 127 ° C or higher, more preferably 133 ° C or higher, still more preferably 136 ° C or higher, and from the viewpoint of the texture of the first nonwoven fabric 112, preferably 145 ° C. Below, it is 140 degrees C or less more preferably, More preferably, it is 138 degrees C or less.
In addition, the heat treatment time is preferably 3 seconds or more, more preferably 5 seconds or more, still more preferably 7 seconds or more, and preferably 14 seconds or less, more preferably 12 seconds from the same viewpoint at the above-mentioned temperature. Second or less, more preferably 10 seconds or less.

  The second web 121 drawn out from the second web manufacturing unit 120 in the direction indicated by MD in the drawing is overlapped with the first nonwoven fabric 112 and is subjected to an embossing process in the embossing unit 140. In the embossing process, the first nonwoven fabric 112 and the second web 121 are partially joined to form the laminated body 101A. Similarly to the first web 111 and the first nonwoven fabric 112, the second web 121 also has a first surface 1S facing the belt that conveys them, and a second surface 2S located on the opposite side of the first surface 1S. . The first nonwoven fabric 112 is arranged and overlapped on the second web 121 so that the second surface 2S of the second web 121 and the low hydrophilic portion LP of the first nonwoven fabric 112 face each other. The embossed portion 140 can be constituted by, for example, an uneven roll 141 and an anvil roll 142. The convex portion of the concave-convex roll 141 corresponds to the shape of the fusion bonded portion 6 having the intermediate bonded portion 61 and the other bonded portion 62 described above. The embossing condition in the embossed part 140 is that the constituent fibers of the first nonwoven fabric 112 and the second web 121 are pressed together while being heated, and the fusion bonded part 6 (see FIG. 3) is formed by embossed fusion. Any condition is acceptable. The second web 121 can also be formed as a non-woven fabric before being superimposed on the first non-woven fabric 112. That is, it can replace with the above-mentioned 2nd web 121, and can superpose | stack the 2nd nonwoven fabric 122 on the 1st nonwoven fabric 112, and can use for an embossing process.

  The laminated body 101A formed by partially joining and integrating the first nonwoven fabric 112 and the second web 121 in the embossed part 140 is conveyed to the second heating part 150 and subjected to a heat shrinking process. Similar to the first heating unit 130, the second heating unit 150 includes a sealed chamber 151, an endless belt (not shown), and a hot-air HW outlet (see FIG. 10) disposed on the first surface 1 S side of the laminate 101 </ b> A. And a suction port (not shown) for hot air HW arranged on the second surface 2S side. The hot air HW in the heat shrinking process is heated to the shrinkage temperature of the latent crimpable fibers constituting the second web 121.

  As described above, the heat treatment in the second heating unit 150 causes the helical crimps of the latent crimpable fibers constituting the second web 121 to appear and contract. In the laminated body 101A, the first nonwoven fabric 112 and the second web 121 are partially joined by the fusion-bonding portion 6. Therefore, the latent crimpable fiber in the second web 121 is thermally shrunk so that the second web 121 is formed. By heat shrinking, a portion other than the fusion bonded portion 6 in the first nonwoven fabric 112 is raised in a convex shape toward the second surface 2S. Thereby, the 1st nonwoven fabric 112 comes to have the several high convex part 1b and the low convex part 1s which protruded toward the 1st nonwoven fabric 112 side from the 2nd web 121 side. As shown in FIG. 4, the high convex portion 1 b is formed in the large polygonal region BT surrounded by the intermediate joint portion 61 and the other joint portion 62, and the low convex portion 1 s is formed in the intermediate joint portion 61 and the other joint portion 62. Is formed in the small polygonal region ST surrounded by. Here, the fibers constituting the low hydrophilic portion LP of the first nonwoven fabric 112 are replaced with the high hydrophilic portion HP by hot air HW from a blowout port (not shown) arranged on the first surface side of the laminate 101A. Compared with the fibers to be configured, the heat treatment is further increased, the degree of penetration of the fiber treatment agent into the fibers is further increased, and the hydrophilicity of the fibers is further decreased. Accordingly, when the high convex portion 1b is cross-sectionally viewed in the thickness direction Z so as to pass through the top portion 1bt, the hydrophilicity of the high convex portion top portion 1bu is higher than the hydrophilicity of the high convex portion bottom portion 1bd, and the low convex portion 1s is When viewed in a cross section in the thickness direction Z so as to pass through the top 1st, the hydrophilicity of the low convex top 1su is higher than the hydrophilicity of the low convex bottom 1sd.

  Further, since the high convex portion 1b is formed in the large polygonal region BT and the low convex portion 1s is formed in the small polygonal region ST, the top portion 1bt of the high convex portion 1b is the top portion 1st of the low convex portion 1s. The fiber density of the top part 1st of the low convex part 1s is higher than the fiber density of the lowermost part of the high convex part 1b, and more than the fiber density of the top part 1bt of the high convex part 1b. It is high. Therefore, the fiber constituting the low hydrophilic portion LP on the lowermost side of the high convex portion 1b by hot air HW from the blowout port (not shown) arranged on the first surface side of the laminate 101A, Compared with the fiber constituting the highly hydrophilic part HP on the top 1st side of the low convex part 1s, the fiber is subjected to a large amount of heat, the degree of penetration of the fiber treatment agent into the fiber is increased, and the hydrophilicity of the fiber is lowered. Therefore, the hydrophilicity of the low convex portion top portion 1su is higher than the hydrophilicity of the high convex portion bottom portion 1bd.

  In the second heating unit 150, it is preferable to change the conveyance speed of the laminated body 101A so that the latent crimpable fibers can contract in the flow direction of the manufacturing apparatus, that is, the MD (Machine Direction) direction. Specifically, it is preferable that the transport speed of the web, the laminated body, and the like in the upstream side of the heat shrinking process, that is, from the card process to the embossing process, is faster than the transport speed of the laminated body 101A in the heat shrinking process. By appropriately adjusting the difference between these conveyance speeds, the degree to which the stacked body 101A contracts can be controlled. At the same time, some of the heat-fusible fibers constituting the second web 121 are heat-bonded to each other, whereby the second web 121 becomes the second nonwoven fabric 122 and the top sheet 1 is manufactured.

  The second web 121 is laminated not on the first web 111 but on the first nonwoven fabric 112 and then subjected to a heat shrinking process. Thereby, compared with the case where the whole laminated body 101A is comprised with the web, the fiber mutually melt | fused of the 1st nonwoven fabric 112 becomes moderate resistance, and a latent crimpable fiber can shrink | contract uniformly within a laminated body. become.

  In the heat shrinking step, the heat treatment time is preferably 6 seconds or more, more preferably 8 seconds or more, still more preferably 10 seconds or more, from the viewpoint of sufficiently expressing the crimps of the latent crimpable fibers to shrink. And from a viewpoint of the texture of the 1st nonwoven fabric 112 and the 2nd nonwoven fabric 122, Preferably it is 20 seconds or less, More preferably, it is 17 seconds or less, More preferably, it is 15 seconds or less.

  In the heat shrinking step, the temperature of the heat treatment when the latent crimpable fiber is composed of polyethylene and polypropylene is preferably 98 ° C. or higher, more preferably 102 ° C. or higher, from the viewpoint of the shrinkage start temperature. The temperature is preferably 105 ° C. or higher, and preferably 145 ° C. or lower, more preferably 140 ° C. or lower, and further preferably 138 ° C. or lower, from the viewpoint of the texture of the first nonwoven fabric 112 and the second nonwoven fabric 122.

  The degree of hydrophilicity of the fibers constituting the second nonwoven fabric 122 does not change depending on the hot air in the second heating unit 150. Since the fiber which comprises the 2nd web 121 has made the fiber treatment agent adhere so that the hydrophilicity may become higher than the fiber which comprises the 1st web 111, the 2nd nonwoven fabric 122 has the highest hydrophilicity. While maintaining the state, the laminated nonwoven fabric 102A in which the hydrophilicity of the first nonwoven fabric 112 has a gradient can be obtained.

  Thus, the manufacturing method of the surface sheet 1 can reduce the hydrophilicity of the heat-fusible fiber to which the fiber treatment agent has been applied by partially reducing the hydrophilicity in the thickness direction of the nonwoven fabric. A gradient is developed. Therefore, according to the above method, it is not necessary to overlap a plurality of nonwoven fabrics to provide a gradient in hydrophilicity, and it is possible to provide a gradient in hydrophilicity along the thickness direction of one single nonwoven fabric.

  The laminated nonwoven fabric 102A manufactured as described above is configured basically in the same manner as the above-described topsheet 1 (see FIGS. 3 and 4), and the first nonwoven fabric 112 (first web 111) is the first. The fiber layer 11 and the second nonwoven fabric 122 (second web 121) correspond to the second fiber layer 12. In the surface sheet 1 manufactured in this manner, the hydrophilicity of the high convex portion top portion 1bu is higher than the hydrophilicity of the high convex portion bottom portion 1bd, and the hydrophilicity of the second fiber layer 12 is the hydrophilicity of the high convex portion top portion 1bu. It is formed higher than. Moreover, the hydrophilicity of the low convex part top part 1su is higher than the hydrophilicity of the low convex part bottom part 1sd, and the hydrophilicity of the 2nd fiber layer 12 is formed higher than the hydrophilicity of the low convex part top part 1su. If such a surface sheet 1 is used for the napkin 10, the hydrophilicity of the second fiber layer 12 is formed higher than the hydrophilicity of the high convex portion top portion 1bu and the low convex portion top portion 1su. The liquid smoothly moves from the first fiber layer 11 to the second fiber layer 12 in spite of the decrease in hydrophilicity toward the side. Furthermore, as described above, since the second fiber layer 12 becomes dense due to heat shrinkage, the liquid held by the first fiber layer 11 is coupled to the second fiber layer 12 in combination with the higher hydrophilicity than the first fiber layer 11. Excellent pulling performance. Therefore, it is difficult for the liquid to remain on the surface, and the liquid once absorbed is unlikely to return to the surface, improving the feeling of use.

As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment.
As shown in FIGS. 3 and 4, the topsheet 1 is replaced with the X direction in the figure corresponding to the vertical direction of the napkin 10, and the Y direction in the figure is made to match the horizontal direction of the napkin 10. The X direction in the middle may coincide with the lateral direction of the napkin 10, and the Y direction in the figure may coincide with the vertical direction of the napkin 10.

  The surface sheet is a surface sheet 1 in which the fusion bonding portion 6 is formed in the form shown in FIG. 13 or FIG. 14 instead of the surface sheet 1 in which the fusion bonding portion 6 having the form shown in FIG. 4 is formed. There may be. Each intermediate joint portion 61 of the topsheet shown in FIG. 13 is arranged independently at a V-shaped two-way extending shape portion 61a, an inverted V-shaped two-way extending shape portion 61a, and an intermediate position thereof. The rectangular independent fusion-bonded portion 61b. Each of the intermediate joint portions 61 of the topsheet 1 shown in FIG. 14 is parallel to the V-shaped two-way extending shape portion 61a, the reverse V-shaped two-way extending shape portion 61a, and the Y direction connecting them. It consists of a rectangular connection fusion splicing part 61c. Regarding the surface sheet 1 shown in FIG. 13 or FIG. 14, the same components as those in the surface sheet 1 shown in FIG.

  The absorbent article using the surface sheet of the present invention may be a sanitary napkin, or other absorbent article such as a panty liner (an incline sheet), an incontinence pad, or a disposable diaper. Examples of the body fluid to be absorbed by the absorbent article include menstrual blood, spillage, loose stool, urine, saliva, blood and the like.

  The following surface sheet for absorbent articles is disclosed further regarding embodiment mentioned above.

<1>
It is a top sheet for an absorbent article having a first fiber layer and a second fiber layer laminated on the first fiber layer, the first fiber layer being located on the skin contact surface side of the wearer. The fiber layer has a plurality of high convex portions protruding from the second fiber layer side toward the first fiber layer side, and a plurality of low convex portions having a height lower than the high convex portion, The inside of the high convex portion and the low convex portion is filled with fibers constituting the first fiber layer, and when the high convex portion passes through the top portion of the high convex portion, the first fiber layer In the first fiber layer, the hydrophilicity of the top portion of the high convex portion on the top side is higher than the hydrophilicity of the bottom portion of the high convex portion on the second fiber layer side of the first fiber layer, and the hydrophilicity of the second fiber layer is A top sheet for absorbent articles that is higher in hydrophilicity than the top of the convex part.

<2>
When the low convex portion is viewed in a cross section in the thickness direction so as to pass through the top portion, the hydrophilicity of the top portion of the low convex portion on the top side of the first fiber layer is the second fiber layer side of the first fiber layer. The hydrophilicity of the bottom of the low convex part is higher than the hydrophilicity of the top part of the low convex part, and the hydrophilicity of the bottom part of the high convex part is higher than the hydrophilicity of the bottom part of the high convex part. The surface sheet for absorbent articles as described in <1> above.
<3>
The hydrophilicity gradually decreases from the top of the high convex portion toward the bottom of the high convex portion, and the hydrophilicity gradually decreases from the top of the low convex portion toward the bottom of the low convex portion, <2> The surface sheet for absorbent articles as described in 2>.
<4>
The fiber density of the top part of the low convex part is higher than the fiber density of the top part of the high convex part, and lower than the fiber density of the second fiber layer, for the absorbent article according to <2> or <3>. Surface sheet.
<5>
The second fiber layer is a heat-shrinkable fiber layer containing heat-shrinkable heat-shrinkable fibers, and the topsheet is a fusion-bonded portion in which the first fiber layer and the second fiber layer are fusion-bonded. The topsheet has a plurality of large polygonal regions surrounded by the plurality of fusion bonded portions, and the fusion bonded portions form apexes of the large polygonal regions, and a plurality of the large majority A plurality of small polygonal areas having a smaller area than the large polygonal area surrounded by the fusion bonded part forming the apex of the rectangular area, and the fusion bonded part is also the apex of the small polygonal area The high convex portion is disposed in each of the large polygon regions, the low convex portion is disposed in each of the small polygon regions, and the plurality of large polygon regions are in the first direction. A large polygonal region row arranged adjacent to each other along the plurality of small polygonal regions Any of <1> to <4>, wherein the small polygonal region rows arranged adjacent to each other along the direction are alternately arranged in a second direction orthogonal to the first direction. The surface sheet for absorbent articles of Claim 1.

（式中、Ｚはエステル基、アミド基、アミン基、ポリオキシアルキレン基、エーテル基若しくは２重結合を含んでいてもよい、炭素数１〜１２の直鎖又は分岐鎖のアルキル鎖を表わし、Ｒ₁及びＲ₂はそれぞれ独立に、エステル基、アミド基、ポリオキシアルキレン基、エーテル基若しくは２重結合を含んでいてもよい、炭素数２〜１６の直鎖又は分岐鎖のアルキル基を表わし、Ｘは―ＳＯ₃Ｍ、―ＯＳＯ₃Ｍ又は―ＣＯＯＭを表わし、ＭはＨ、Ｎａ、Ｋ、Ｍｇ、Ｃａ又はアンモニウムを表わす。）
＜９＞
前記第１繊維層と前記第２繊維層との間には他の層が存在しない、前記＜１＞〜＜８＞の何れか１に記載の吸収性物品用の表面シート。 <6>
The high convex portion in the large polygonal region adjacent to each other and the low convex portion in the small polygonal region are arranged between the fusion-bonding portions forming the apex portion. And the connecting protrusions extending continuously over the low protrusions, and the connecting protrusions have the first fiber layer from the second fiber layer side toward the first fiber layer side. The top sheet for absorbent articles according to <5>, wherein the top sheet protrudes lower than the low convex portion.
<7>
The large polygonal region is formed in a hexagonal shape surrounded by the six fusion-bonded portions, and the small polygonal region is formed in a rectangular shape surrounded by the four fusion-bonded portions. When attention is paid to the low convex portions in the four small polygonal regions, the high convex portions in the four hexagonal large polygonal regions are adjacent to each other. The top sheet for absorbent articles according to <6>, wherein the high convex portion is connected to the connecting convex portion.
<8>
The first fiber layer has heat-fusible fibers to which a fiber treatment agent is attached, and the fiber treatment agent contains the following component (A), component (B), and component (C) < The surface sheet for absorbent articles according to any one of 1> to <7>.
(A) polyorganosiloxane (B) alkyl phosphate ester (C) anionic surfactant represented by the following general formula (1) or polyoxyalkylene-modified polyhydric alcohol fatty acid ester

(In the formula, Z represents an ester group, an amide group, an amine group, a polyoxyalkylene group, an ether group or a linear or branched alkyl chain having 1 to 12 carbon atoms, which may contain a double bond; R ₁ and R ₂ each independently represents an ester group, an amide group, a polyoxyalkylene group, an ether group or a linear or branched alkyl group having 2 to 16 carbon atoms, which may contain a double bond. , X represents —SO ₃ M, —OSO ₃ M or —COOM, and M represents H, Na, K, Mg, Ca or ammonium.)
<9>
The top sheet for absorbent articles according to any one of <1> to <8>, wherein no other layer is present between the first fiber layer and the second fiber layer.

<10>
The absorption according to any one of <5> to <9>, wherein the ratio of the area of the fusion bonded portion to the total area of the topsheet is 5% to 30%, preferably 7% to 20%. Surface sheet for functional articles.
<11>
The top sheet for an absorbent article according to <7>, wherein the high convex part is a convex part having an elliptical planar shape, and the low convex part is a convex part having a circular planar shape.
<12>
The absorption according to any one of <1> to <11>, wherein the height at the apex in the thickness direction of the high convex portion is 1.0 mm or more and 7.0 mm or less, preferably 1.5 mm or more and 5.0 mm or less. Surface sheet for functional articles.
<13>
The top sheet for absorbent articles according to any one of the above items <1> to <12>, wherein a protruding angle from the bottom surface of the high convex portion is 70 ° to 90 °, preferably 75 ° to 85 °. .
<14>
The absorption according to any one of <1> to <13>, wherein the height at the apex in the thickness direction of the low convex portion is 0.4 mm to 4.5 mm, preferably 0.8 mm to 2.5 mm. Surface sheet for functional articles.
<15>
The surface sheet for absorbent articles according to any one of the above items <1> to <14>, wherein the raised angle from the bottom surface of the bottom convex portion is 25 ° or more and 70 ° or less, preferably 30 ° or more and 65 ° or less. .

<16>
The ratio of the fiber density at the apex in the thickness direction of the low convex portion to the fiber density at the apex in the thickness direction of the high convex portion is 1.2 times or more and 3.0 times or less, preferably 1.5 times or more. The top sheet for absorbent articles according to any one of the above items <1> to <15>, which is 5 times or less.
<17>
The top sheet for absorbent articles according to any one of <1> to <16>, wherein the first fiber layer has a thickness of 0.5 mm to 3.0 mm.
<18>
The top sheet for absorbent articles according to any one of <1> to <17>, wherein the thickness of the second fiber layer is 0.5 mm or more and 2.0 mm or less.
<19>
Absorbent article according to any one of <1> to <18>, wherein the basis weight of the surface sheet is 20 g / m ² or more and 200 g / m ² or less, preferably 50 g / m ² or more and 100 g / m ² or less. Surface sheet.
<20>
In the first fiber layer, the contact angle of water at the top of the high convex portion is 65 ° or more and 89 ° or less, preferably 65 ° or more and 85 ° or less, and particularly preferably 73 ° or more and 75 ° or less. <19> The surface sheet for absorbent articles according to any one of the above.
<21>
In the first fiber layer, the water contact angle of the bottom of the high convex portion is 75 ° or more and 90 ° or less, preferably 80 ° or more and 88 ° or less, and particularly preferably 85 ° or more and 86 ° or less. The top sheet for absorbent articles according to any one of <20>.

<22>
The difference between the contact angle of water at the bottom of the high protrusion and the contact angle of water at the top of the high protrusion is 1 ° to 20 °, preferably 5 ° to 18 °, particularly preferably 7 ° to 15 °. The top sheet for absorbent articles according to any one of the above items <1> to <21>.
<23>
The ratio of the contact angle of water at the top of the high protrusion to the contact angle of water at the bottom of the high protrusion is from 0.7 to 0.95, preferably from 0.75 to 0.85, particularly preferably 0.8. The top sheet for absorbent articles according to any one of <1> to <22>, which is at least 0.85.
<24>
In the first fiber layer, the contact angle of water at the top of the low convex portion is 65 ° or more and 89 ° or less, preferably 70 ° or more and 85 ° or less, and particularly preferably 73 ° or more and 75 ° or less <1>. The surface sheet for absorbent articles according to any one of to <23>.
<25>
In the first fiber layer, the contact angle of water at the bottom of the low convex portion is 75 ° or more and 90 ° or less, preferably 80 ° or more and 88 ° or less, and particularly preferably 85 ° or more and 86 ° or less. <24> The surface sheet for absorbent articles according to any one of the above.

<26>
The difference between the contact angle of water at the bottom of the low protrusion and the contact angle of water at the top of the low protrusion is 1 ° or more and 20 ° or less, 5 ° or more and 18 ° or less, and 7 ° or more and 15 ° or less. The surface sheet for absorbent articles according to any one of> to <25>.
<27>
The ratio of the contact angle of water at the top of the low convex part to the contact angle of water at the bottom of the low convex part is 0.7 or more and 0.95 or less, preferably 0.75 or more and 0.9 or less, particularly preferably 0.8. The surface sheet for absorbent articles according to any one of <1> to <26>, which is 80 or more and 0.85 or less.
<28>
The difference between the contact angle of water at the bottom of the high protrusion and the contact angle of water at the top of the low protrusion is 1 ° or more and 20 ° or less, 5 ° or more and 18 ° or less, and 7 ° or more and 15 ° or less. The surface sheet for absorbent articles according to any one of> to <>.
<29>
The ratio of the contact angle at the top of the low protrusion to the contact angle of water at the bottom of the high protrusion is from 0.7 to 0.9, preferably from 0.75 to 0.88, particularly preferably 0.8. The top sheet for absorbent articles according to any one of <1> to <28>, which is at least 0.85.
<30>
Any one of the above items <1> to <29>, wherein the contact angle of water of the second fiber layer is 50 ° to 70 °, preferably 55 ° to 65 °, particularly preferably 57 ° to 60 °. The surface sheet for absorbent articles described in 1.
<31>
The ratio of the contact angle of water in the second fiber layer with respect to the contact angle in the portion having the smaller contact angle of water among the top portions of the high and low convex portions is 0.65 or more and 0.95 or less, preferably Is a surface sheet for absorbent articles according to any one of the above items <1> to <30>, which is 0.7 or more and 0.9 or less, particularly preferably 0.75 or more and 0.85 or less.
<32>
The ratio of the contact angle of water in the second fiber layer with respect to the contact angle in the portion having the larger contact angle of water among the top portion of the high convex portion and the top portion of the low convex portion is 0.55 or more and 0.85 or less, preferably The top sheet for absorbent articles according to any one of <1> to <31>, which is 0.6 to 0.8, particularly preferably 0.65 to 0.75.

<33>
The absorbent article which used the surface sheet in any one of said <1>-<32>, and was equipped with the absorber at the 2nd fiber layer side of the said surface sheet.

<34>
The absorbent article has a longitudinal direction corresponding to the longitudinal direction of the wearer and a lateral direction perpendicular to the longitudinal direction, and the large polygon row and the small polygon row each extend in the lateral direction. And the absorbent article as described in said <33> currently arranged alternately by the vertical direction.
<35>
The absorbent article according to <34>, wherein a distance between adjacent small polygon regions in the small polygon row is shorter than a distance between small polygon regions located closest to each other in the vertical direction.
<36>
The absorbent article includes a central portion in the longitudinal direction, a front portion positioned on the front side of the wearer from the central portion, and a rear portion positioned on the rear side of the wearer from the central portion, and the topsheet and <34> or <35> according to <34> or <35>, wherein a compression groove on a round formed by integrally compressing the absorbent body extends in the longitudinal direction and extends from the front part to the rear part. Absorbent article.
<37>
The absorbent article according to any one of <33> to <36>, which is a sanitary napkin.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples. Unless otherwise specified, “%” means “mass%”.

[Example 1]
(1) The heat-fusible fiber constituting the first fiber layer 11 (first web) is a concentric core-sheath type composite fiber in which the core is polyethylene terephthalate and the sheath is polyethylene, and the mass ratio between the core and the sheath is Core: sheath = 50: 50, the fineness was 2.4 dtex, and the fiber length was 51 mm.
The heat-fusible fiber (1) was immersed in a fiber treatment agent (oil agent) I having the following composition. After the immersion, drying was performed to obtain a heat-fusible core-sheath composite fiber to which a fiber treatment agent was adhered. The amount of the oil agent attached to the fiber was 0.39% by mass.

Composition of fiber treatment agent (oil agent) I: polyorganosiloxane (component (A), silicone “KM-903” manufactured by Shin-Etsu Silicone): 8.3% by mass
The composition of silicone “KM-903” is as follows. 18% by weight of polydimethylsiloxane having a weight average molecular weight of about 500,000, 42% by weight of polydimethylsiloxane having a weight average molecular weight of about 20,000, 5% by weight of a dispersant, 35% by weight of water
Alkyl phosphate potassium salt [the component (B), manufactured by Kao Corporation, neutralized potassium hydroxide of gripper 4131]: 22.9% by mass
Dialkylsulfosuccinate sodium salt [component (C), manufactured by Kao Corporation, Perex OT-P]: 9.2% by mass
Alkyl (stearyl) betaine [components other than the above (A) to (C), manufactured by Kao Corporation, Amphitol 86B]: 13.8% by mass
Polyoxyethylene (number of moles added: 2) stearylamide [components other than the above (A) to (C), manufactured by Kawaken Fine Chemicals, Amizole SDE]: 27.5% by mass
Polyoxyethylene (POE), polyoxypropylene (POP) modified silicone [components other than the above (A) to (C), manufactured by Shin-Etsu Chemical Co., Ltd., X-22-4515]: 18.3 mass%

The blending amount of the component (A) adhering to the fiber is a blending amount of silicone alone in the composition of “KM-903”, and is not a blending amount of “KM-903” as a whole. In Example 1, the blending amount of the component (A) attached to the heat-fusible fiber of the first fiber layer was 5.0%.
Similarly, regarding the component (B) and the component (C), the blending amount of only the component excluding water contained in the fiber treatment agent is 23.8% for the component (B) and the component (C). Was 9.5%.

(2) Latent crimpable fibers (heat-shrinkable fibers) constituting the second fiber layer 12 (second web)
A side-by-side type composite fiber in which one side is polypropylene and the other side is polyethylene, the volume ratio of each resin is 50:50, the fineness is 2.3 dtex, and the fiber length is 51 mm. The thermal contraction rate of the core resin at the melting point + 10 ° C. was 9.5%.
The latent crimpable fiber (2) was immersed in a known fiber treatment agent (oil agent).

Production of Nonwoven Fabric Using the fibers obtained in (1) and (2), a top sheet 1 shown in FIGS. 3 and 4 was produced using a production apparatus 100 shown in FIG. Specifically, first, hot air was blown from the second surface side to the first web formed using the first web manufacturing unit in the hydrophilicity lowering step to obtain a first nonwoven fabric (first fiber layer 11). Next, a first nonwoven fabric is arranged on the second web formed using the second web manufacturing unit to obtain a laminate, and the laminate is embossed to partially separate the first nonwoven fabric and the second web. Joined. Next, in the heat shrinking step, hot air was blown from the first surface side (second web side) of the laminate to make the second web a second nonwoven fabric (second fiber layer), and an uneven laminated nonwoven fabric was obtained.

The shape of the convex portion of the concavo-convex roll 141 used for the embossing corresponded to the shape of the fusion bonded portion 6 having the intermediate bonded portion 61 and the other bonded portion 62 of the topsheet 1. As shown in FIG. 4, the obtained nonwoven fabric has a large polygon region row BTL in which a plurality of large polygon regions BT are arranged adjacent to each other along the Y direction, and a plurality of small polygon regions STL in the Y direction. The small polygonal region rows STL arranged adjacent to each other along the line are alternately arranged in the X direction. The fusion bonded portion 6 includes an intermediate bonded portion 61 and another bonded portion 62. The intermediate joint 61 has an X shape with four protrusions, and the other joint 62 has a Y shape with three protrusions. The shape of the fusion bonded portion 6 is a combination of an X-shaped intermediate bonded portion 61 and a Y-shaped other bonded portion 62. As described above, embossing is performed to bond the first nonwoven fabric and the second web. A hot air of 110 ° C. ± 10 ° C. is passed through the partially bonded laminate for 5 to 10 seconds to crimp the heat-shrinkable fibers of the second web, shrink the second fiber layer 12 and the first fibers The surface sheet which protruded the layer 11 in convex shape and has many high convex part 1b and low convex part 1s of a three-dimensional dome structure was manufactured. The fusion-bonding portions 6 are arranged at 6 pieces / cm ² , and the closest distance between two adjacent fusion-bonding portions 6 in the Y direction of the surface sheet after heat shrinkage is 1.1 mm. The average area of the part 61 was 2.3 mm ² , and the average area of the other joint part 62 was 1.6 mm ² . The four protrusions of the X-shaped intermediate joint 61 and the three protrusions of the Y-shaped other joint 62 were the same 0.85 mm. Moreover, the height hb of the high convex part 31 was 2.3 mm, and the height hs of the low convex part 32 was 1.5 mm. Moreover, the crossing angle θ1 between the protrusions constituting the intermediate joint 61 was 90 °, and the crossing angle θ2 between the protrusions constituting the other joint 62 was 130 °.

[Comparative Example 1]
Except for changing the shape of the convex portion of the uneven roll 141 used for the embossing and the fiber treatment agent (oil agent) attached to the heat-fusible fiber constituting the first fiber layer 11 (first web). The surface sheet of Comparative Example 1 was obtained in the same manner as the surface sheet of Example 1. First, the fusion-bonded portion was composed of only a circular bonded portion, and in the obtained surface sheet, the circular fusion-bonded portion was evenly arranged in the X direction and the Y direction. The circular fusion-bonded portions are arranged at 7.1 pieces / cm ² , and the closest distance between two adjacent fusion-bonded portions in the Y direction of the surface sheet after heat shrinkage is 1.6 mm. The average area of the circular fusion bonded part was 3.2 mm ² . In the top sheet of Comparative Example 1, the convex portions of the solid dome structure having one type of height were evenly arranged in the X direction and the Y direction. The height of the convex portion was 2.3 mm.
Further, for the first fiber layer 11 (first web), a heat-fusible fiber immersed in a fiber treatment agent (oil agent) III was used. After the immersion, drying was performed to obtain a heat-fusible core-sheath composite fiber to which a fiber treatment agent was adhered. The adhesion amount of the oil agent to the fiber was 0.39% by mass. Fiber treatment agent III was obtained by removing component (A) from fiber treatment agent I.

[Comparative Example 2]
A surface sheet of Comparative Example 1 was obtained in the same manner as the surface sheet of Example 1, except that the shape of the convex portion of the uneven roll 141 used for the embossing was changed. The fusion-bonded portion consisted of only a circular bonded portion, and in the obtained surface sheet, the circular fusion-bonded portion was evenly arranged in the X direction and the Y direction. The circular fusion-bonded portions are arranged at 7.1 pieces / cm ² , and the closest distance between two adjacent fusion-bonded portions in the Y direction of the surface sheet after heat shrinkage is 1.6 mm. The average area of the circular fusion bonded part was 3.2 mm ² . In the top sheet of Comparative Example 1, the convex portions of the solid dome structure having one type of height were evenly arranged in the X direction and the Y direction. The height of the convex portion was 2.3 mm.

[Performance evaluation]
About each surface sheet of Example 1 and Comparative Examples 1-2, the contact angle in each site | part in a 1st fiber layer and the contact angle in a 2nd fiber layer were measured with the measuring method of the contact angle mentioned above. Specifically, for the surface sheet of Example 1, the contact angle of the high convex portion top portion 1bu, the contact angle of the high convex portion bottom portion 1bd, the contact angle of the low convex portion top portion 1su, the contact angle of the low convex portion bottom portion 1sd, The contact angle of the second fiber layer 12 was measured. About each surface sheet of Comparative Examples 1-2, the contact angle of the convex part top part, the contact angle of a convex part bottom part, and the contact angle of the 2nd fiber layer 12 were measured. Moreover, about each surface sheet of Example 1 and Comparative Examples 1-2, the surface liquid return amount and the surface liquid remaining amount were evaluated according to the following method. The evaluation environment was a room temperature of 20 ° C. and a humidity of 60% RH. The results are shown in Table 1 below.

[Measurement of remaining liquid suction]
Each surface sheet obtained in Example 1 and Comparative Examples 1 and 2 was cut into a size of 60 mm (CD direction) × 80 mm (MD direction), and each of them was an absorbent sheet of the same shape and the same size (pulp 200 g / m ² and A sample for evaluation was obtained by adhering to an absorbent polymer (50 g / m ² ) via a hot melt adhesive. In addition, each surface sheet arrange | positioned the 1st fiber layer side toward the wearer's skin contact surface side.
Next, 1.0 g of defibrinated horse blood whose viscosity was previously adjusted to 8 ± 0.1 cP was dropped on the horizontal and smooth surface of the acrylic plate, and then the sample was placed on the non-woven fabric side ( The surface sheet side) was piled up so as to come into contact with the defibrinated horse blood, and further, a weight (acrylic plate) was piled on the sample, and a load of 0.36 g / m ² was applied to the sample. Sixty seconds after stacking the weight stones, the weight stones and the sample were removed, and the amount of defibrinated horse blood remaining on the surface of the acrylic plate was measured. The amount of defibrinated horse blood remaining on the surface of the acrylic plate was measured using a commercially available tissue paper as follows. That is, defibrinated horse blood remaining on the surface of the acrylic plate was absorbed with tissue paper whose weight was measured in advance, and the weight of the tissue paper after absorption was measured. The amount of defibrinated horse blood remaining on the surface of the acrylic plate (mg) by subtracting the pre-measured weight of tissue paper before defibrated horse blood absorption from the weight of tissue paper after defibrinated horse blood absorption. Asked. The above operation was performed three times, and the average value of the three times was defined as the remaining amount of liquid sucked up. The remaining amount of liquid sucked up serves as an index of the liquid drawing-in property, and it can be evaluated that the smaller the remaining amount of liquid sucking up, the higher the liquid drawing-in property and the better the liquid absorbing property. The results are shown in Table 1 below. The viscosity of defibrinated horse blood is adjusted by adjusting the blood cell / plasma ratio of defibrated horse blood manufactured by Nippon Biotest Co., Ltd. 10M, measurement conditions: rotor No. 19, 30 rpm, 25 ° C., 60 seconds).

[Evaluation of surface liquid return amount]
Each surface sheet obtained in Example 1 and Comparative Examples 1 and 2 was cut into a size of 60 mm (CD direction) × 80 mm (MD direction), and each of them was an absorbent sheet of the same shape and the same size (pulp 200 g / m ² and A sample for evaluation was obtained by adhering to an absorbent polymer (50 g / m ² ) via a hot melt adhesive. In addition, each surface sheet arrange | positioned the 1st fiber layer side toward the wearer's skin contact surface side.
Next, a sample for evaluation was placed horizontally, and an acrylic plate with a cylinder with a 1 cm diameter injection port on the bottom was placed on the sample, and the viscosity was adjusted to 40 ± 0.1 cP in advance from the injection port (physiology). A total of 6.0 g of defibrinated equine blood (assuming high-viscosity menstrual blood seen in the first half, etc.) was injected in an amount of 3.0 g, and the state was maintained for 1 minute after the injection. The viscosity of defibrinated horse blood was adjusted in the same manner as in [Measurement of remaining liquid uptake].
Next, the acrylic plate with a cylinder is removed, and 16 sheets of absorbent paper (commercially available tissue paper) with a basis weight of 13 g / m ² and a basis weight of 13 g / m ² are stacked on the skin contact surface side surface of the top sheet. I put it. Further, a weight was placed thereon so that the pressure was 4.0 × 10 ² Pa, and pressure was applied for 5 seconds. After pressing, remove the absorbent paper, measure the weight of the paper before and after pressing, and subtract the weight of the paper measured before pressing from the weight of the pressed paper. The weight of defibrinated horse blood absorbed in the solution was measured and used as the surface liquid return amount. The above operation is performed three times, and the average value of the three times is defined as the liquid return amount (mg). The smaller the liquid return amount, the less likely the liquid return occurs and the higher the evaluation. The results are shown in Table 1 below.
Similarly, the amount of liquid return (mg) was measured under the condition where 3.0 g of defibrinated horse blood was poured every 3 minutes, and the results are shown in Table 1 below.

  As is clear from the results shown in Table 1, the sample using the top sheet of Example 1 has the lowest liquid return amount compared to the sample using the top sheet of Comparative Examples 1 and 2, and the liquid on the sample surface. Indicates that it is difficult to remain. In addition, the sample using the top sheet of Example 1 has a lower liquid suction remaining amount and a higher liquid draw-in property than the sample using the top sheet of Comparative Example 2. Therefore, the sanitary napkin using the surface sheet of Example 1 is unlikely to have a liquid remaining on the surface of the sanitary napkin, and the liquid once absorbed is unlikely to return to the surface, and an improvement in usability can be expected.

10 Absorbent articles (Sanitary napkins)
DESCRIPTION OF SYMBOLS 1 Top sheet 1b High convex part 1bL High convex part row 1bu High convex part top part 1bd High convex part bottom part 1s Low convex part 1sL Low convex part row 1su Low convex part top part 1sd Low convex part bottom part 1c Connection convex part 2 Back surface sheet 3 Absorption Body 4 Side sheet 5 Wing part 6 Fusion joint part 61 Intermediate joint part 62 Other joint part 100 Manufacturing apparatus 110 First web production part 120 Second web production part 130 First heating part 140 Emboss part 150 Second heating part

Claims (8)

It has a first fiber layer and a second fiber layer laminated on the first fiber layer, and the first fiber layer is a top sheet for absorbent articles located on the skin contact surface side of the wearer,
The first fiber layer has a plurality of high convex portions protruding from the second fiber layer side toward the first fiber layer side, and a plurality of low convex portions having a height lower than the high convex portion. And the high convex portion and the low convex portion are filled with fibers constituting the first fiber layer,
When the high convex portion is viewed in cross section in the thickness direction so as to pass through the top portion, the hydrophilicity of the top portion of the high convex portion on the first fiber layer is the second fiber layer side of the first fiber layer. Higher than the hydrophilicity of the bottom of the high convex part, the hydrophilicity of the second fiber layer is higher than the hydrophilicity of the top part of the high convex part,
When the low convex portion is viewed in a cross section in the thickness direction so as to pass through the top portion, the hydrophilicity of the top portion of the low convex portion on the top side of the first fiber layer is the second fiber layer side of the first fiber layer. The hydrophilicity of the bottom of the low convex part is higher than the hydrophilicity of the top part of the low convex part, and the hydrophilicity of the bottom part of the high convex part is higher than the hydrophilicity of the bottom part of the high convex part. Higher surface sheet for absorbent articles. The hydrophilicity gradually changes from the top of the high convex portion toward the bottom of the high convex portion, and the hydrophilicity changes from the top of the low convex portion to the bottom of the low convex portion. The top sheet for absorbent articles according to 1 . The top sheet for absorbent articles according to claim 1 or 2 , wherein the fiber density of the top part of the low convex part is higher than the fiber density of the top part of the high convex part and lower than the fiber density of the second fiber layer. The second fiber layer is a heat-shrinkable fiber layer containing heat-shrinkable fibers that have been heat-shrinked,
The surface sheet includes a plurality of fusion bonding portions in which the first fiber layer and the second fiber layer are fusion bonded,
The surface sheet has a plurality of large polygonal regions surrounded by the plurality of fusion bonded portions, and the fusion bonded portions form apexes of the large polygonal regions, and the apexes of the plurality of large polygonal regions A plurality of small polygonal areas having a smaller area than the large polygonal area, surrounded by the fusion-bonding part forming part, and the fusion-bonding part also forms the apex of the small polygonal area,
The high convex portion is disposed in each of the large polygon regions, and the low convex portion is disposed in each of the small polygon regions,
A plurality of large polygon regions are arranged adjacent to each other along the first direction, and a plurality of small polygon regions are arranged adjacent to each other along the first direction. The top sheet for absorbent articles according to any one of claims 1 to 3 , wherein the small polygonal region rows configured as described above are alternately arranged in a second direction orthogonal to the first direction. . The high convex portion in the large polygonal region adjacent to each other and the low convex portion in the small polygonal region are arranged between the fusion-bonding portions forming the apex portion. And the connecting protrusions extending continuously over the low protrusions,
5. The absorbent article according to claim 4 , wherein the connection convex portion has the first fiber layer bulges lower than the low convex portion from the second fiber layer side toward the first fiber layer side. Surface sheet. The large polygonal region is formed in a hexagonal shape surrounded by the six fusion bonded portions, and the small polygonal region is formed in a quadrangular shape surrounded by the four fusion bonded portions,
When attention is paid to the low convex portion in the small polygonal region of one quadrangular shape, the high convex portions in the four large hexagonal regions of the hexagonal shape are adjacent to each other. The top sheet for absorbent articles according to claim 5 , wherein the two high convex portions are connected by the connecting convex portion. The said 1st fiber layer has the heat-fusible fiber to which the fiber processing agent adhered, The said fiber processing agent contains the following (A) component, (B) component, and (C) component. Item 7. The top sheet for absorbent articles according to any one of items 1 to 6 .
(A) polyorganosiloxane (B) alkyl phosphate ester (C) anionic surfactant represented by the following general formula (1) or polyoxyalkylene-modified polyhydric alcohol fatty acid ester

(In the formula, Z represents an ester group, an amide group, an amine group, a polyoxyalkylene group, an ether group or a linear or branched alkyl chain having 1 to 12 carbon atoms, which may contain a double bond; R ₁ and R ₂ each independently represents an ester group, an amide group, a polyoxyalkylene group, an ether group or a linear or branched alkyl group having 2 to 16 carbon atoms, which may contain a double bond. , X represents —SO ₃ M, —OSO ₃ M or —COOM, and M represents H, Na, K, Mg, Ca or ammonium.) Either using a surface sheet according to item 1, an absorbent article having an absorber on the second fiber layer side of the topsheet of claims 1-7.

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