JP2017093867A - Non-woven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonwoven fabric excellent in touch to the skin and cushion feeling, and an absorbent article using the same.SOLUTION: A plurality of hollow projections 24 are scattered in one surface 2a of a nonwoven fabric 2, and apertures 240 for communicating the inside and outside of the projections 24 are formed in a crown 24a at least in a part of the plurality of projections 24. In the projection 24 formed with the aperture 240, a distance between fibers of the constituent fiber existing in the crown 24a is equal to or more than a distance between fibers of the constituent fiber existing in a portion excluding the crown 24a. The nonwoven fabric 2 is preferably usable as a surface sheet in an absorbent article which includes an absorber and the surface sheet arranged on a skin facing side of the absorber.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a nonwoven fabric having irregularities on one side.

  Nonwoven fabric is widely used as a sheet (surface sheet) that forms the skin facing surface of absorbent articles such as disposable diapers and sanitary napkins, and the nonwoven fabric for the surface sheet has good touch and cushion feeling. It is requested. As means for improving the touch and cushion feeling of a nonwoven fabric, methods for imparting irregularities to the nonwoven fabric are conventionally known, and various such irregular nonwoven fabrics have been proposed.

  For example, in Patent Document 1, a first protrusion that protrudes toward the first surface on the side of the sheet-like nonwoven fabric in plan view, and a second protrusion that protrudes toward the second surface opposite to the first surface. A non-woven fabric having a single-layer structure in which both protrusions are alternately and continuously arranged in different directions intersecting in plan view of the nonwoven fabric. In the nonwoven fabric described in Patent Document 1, the first protruding portion is a convex portion, the second protruding portion is a concave portion, and the top of the second protruding portion, that is, the bottom of the concave portion is formed with a through hole, thereby absorbing the liquid. In addition, it is said that the liquid becomes easy to flow along the alignment direction. According to Patent Document 1, since the fibers around the through hole are oriented toward the center of the through hole, the nonwoven fabric described in Patent Document 1 is less likely to be crushed and maintains good cushioning properties. It is supposed to be possible.

  Further, in Patent Document 2, the first sheet and the second sheet are partially joined to form a large number of joined portions, and a convex portion is formed on a portion other than the joined portions in the first sheet. In the composite sheet in which is formed, an opening is formed in a non-joined portion of the second sheet that is opposed to the convex portion of the second sheet. According to Patent Document 2, such a composite sheet is excellent in flexibility and breathability in addition to high liquid permeability, and is said to be useful as a surface sheet of an absorbent article.

JP 2013-133574 A JP 2007-130817 A

  The uneven nonwoven fabrics described in Patent Documents 1 and 2 have good touch and cushion feeling, but the versatility of the uneven nonwoven fabric has increased in recent years, and the level of touch and cushion feeling required for the uneven nonwoven fabric is It is higher. Non-woven fabrics having a high level of touch and cushion feeling that have been requested in recent years have not yet been provided.

  Therefore, the subject of this invention is related with providing the nonwoven fabric excellent in the touch and cushion feeling.

  In the present invention, a plurality of hollow convex portions are scattered on one side, and an opening communicating with the inside and outside of the convex portion is formed at the top of at least a part of the plurality of convex portions, and the opening is formed. In addition, in the convex part, a non-woven fabric is provided in which the inter-fiber distance of the constituent fibers existing at the top is equal to or greater than the inter-fiber distance of the constituent fibers existing at a part other than the top.

  Moreover, this invention is an absorbent article which comprises an absorber and the surface sheet distribute | arranged to the skin opposing surface side of this absorber, Comprising: The said surface sheet is an absorbent article which is the nonwoven fabric of the said this invention. It is to provide.

  ADVANTAGE OF THE INVENTION According to this invention, the nonwoven fabric excellent in the touch and the feeling of cushion, and an absorbent article using the same are provided.

FIG. 1 is a plan view schematically showing a skin facing surface, that is, a surface sheet side of a disposable diaper that is an embodiment of the absorbent article of the present invention, in which an elastic member of each part is expanded and expanded in a planar shape. It is a top view in a state. FIG. 2 is a cross-sectional view schematically showing a cross section taken along line II of FIG. FIG. 3 is a perspective view schematically showing a part on the skin facing surface side of the surface sheet (one embodiment of the nonwoven fabric of the present invention) arranged in the diaper shown in FIG. 1. FIG. 4 is a cross-sectional view schematically showing a cross section along the thickness direction (height direction of the convex portion) of the topsheet shown in FIG. FIG. 5 is a cross-sectional view (corresponding to FIG. 4) schematically showing a cross section along the thickness direction (height direction of the convex portion) of another embodiment of the nonwoven fabric of the present invention.

  Hereinafter, the nonwoven fabric of this invention is demonstrated with reference to drawings based on those preferable embodiment with the absorbent article of this invention which comprises this. The disposable diaper 1 which is one Embodiment of the absorbent article of this invention is shown by FIG.1 and FIG.2. The diaper 1 has an abdominal side 1F arranged on the abdomen side of the wearer when worn, a back side 1R arranged on the dorsal side, and a crotch 1M positioned therebetween, and from the abdominal side 1F. It extends to the back side 1R via the crotch 1M, and has a longitudinal direction X corresponding to the wearer's front-rear direction and a lateral direction Y orthogonal thereto. The crotch part 1M has an excretion part facing part that is disposed to face an excretion part such as a wearer's penis when the diaper 1 is worn, and the excretion part facing part is usually a central part in the longitudinal direction X of the diaper 1 Or it is located in the vicinity.

  As shown in FIGS. 1 and 2, the diaper 1 is an absorbent body 4, a liquid-permeable surface sheet 2 that is disposed on the skin-facing surface side of the absorbent body 4 and can come into contact with the wearer's skin when worn. And a liquid-impermeable or water-repellent back sheet 3 disposed on the non-skin facing surface side of the absorbent body 4, and in the longitudinal direction X located in the crotch 1M in a plan view as shown in FIG. The central part is inward and has a long hourglass shape that is long in one direction, that is, in the vertical direction X. Each of the top sheet 2 and the back sheet 3 has a size larger than that of the absorber 4 interposed between the sheets 2 and 3. The back sheet 3 has a size larger than that of the top sheet 2 and extends outward from the peripheral edge of the absorbent body 4 to form the outer shape of the diaper 1 in a developed and extended state as shown in FIG. As the back sheet 3, various materials conventionally used for this type of absorbent article can be used without particular limitation, and a resin film, a laminate of a resin film and a nonwoven fabric, or the like can be used.

  In the present specification, the “skin-opposing surface” is a surface of the absorbent article or a component thereof (for example, the surface sheet 2) that is directed toward the wearer's skin when the absorbent article is worn, that is, the wearer's skin. The side close to the skin, and the “non-skin facing surface” is directed toward the side opposite to the skin side when the absorbent article is worn, that is, the side relatively distant from the wearer's skin. It is the surface to be. In addition, "at the time of wearing" here means a state where a normal proper wearing position, that is, a correct wearing position of the absorbent article is maintained, and the absorbent article is in a state of being deviated from the wearing position. Is not included.

  The absorber 4 has a shape that is long in the longitudinal direction X in a plan view as shown in FIG. 1, and extends from the ventral side 1F to the dorsal side 1R. The absorbent body 4 includes a liquid-retaining absorbent core 40 containing an absorbent material, and a core wrap sheet 41 that covers the skin facing surface and the non-skin facing surface of the absorbent core 40. The absorbent core 40 and the core wrap sheet 41 are joined by a known joining means such as a hot-melt adhesive. The absorptive core 40 has a single-layer structure and has an hourglass shape in which a central portion in the longitudinal direction, that is, the longitudinal direction X is inwardly bounded in a plan view as shown in FIG.

  The absorbent core 40 is formed by stacking a core forming material including an absorbent material. As the absorbent material, those normally used as a material for forming this type of absorbent core can be used without any particular limitation. For example, hydrophilic fibers such as wood pulp, synthetic fibers treated with a hydrophilizing agent, and water absorption Include polymer particles. That is, the absorbent core 40 may be a hydrophilic fiber stack or a structure in which water-absorbing polymer particles are supported on the stack. Moreover, as the core wrap sheet | seat 41, a water-permeable sheet | seat material can be used, for example, paper, a nonwoven fabric, etc. can be used. The core wrap sheet 41 in the present embodiment is a single continuous sheet having a width that is not less than 2 times and not more than 3 times the length of the absorbent core 40 in the lateral direction Y. However, the present invention is not limited to this. For example, it includes a skin-side core wrap sheet that covers the skin-facing surface of the absorbent core 40 and a non-skin-side core wrap sheet that covers the non-skin-facing surface of the absorbent core 40. It may be a body sheet.

  Side sheets 5 are arranged on the left and right sides along the longitudinal direction X on the surface sheet 2 side of the diaper 1. The side seat 5 has an inner edge along the vertical direction X, and an outer edge along the vertical direction X that is located outside the inner edge in the lateral direction Y, and has a flat surface as shown in FIG. In view, the inner edge overlaps with the absorber 4, and the outer edge extends outward in the lateral direction Y from the side edge along the longitudinal direction X of the absorber 4, as shown in FIG. 3 is joined. Between the side sheet 5 and the back sheet 3 in the left and right leg portions arranged around the legs of the wearer, a thread-like elastic member 50 is fixed in an elongated state along the vertical direction X. A pair of leg gathers is formed in the leg portion when the diaper 1 is worn by contraction of the elastic member 50. Further, a thread-like elastic member 51 is fixed to the inner edge portion of the side seat 5 in an elongated state along the longitudinal direction X. Accordingly, when the diaper 1 is worn, at least the crotch 1M due to the contraction of the elastic member 51. In the side sheet 5, the inner edge side stands up toward the wearer's skin side starting from the joint with the back sheet 3 to form a leak-proof cuff. This leak-proof cuff can prevent outflow of excretion fluid such as urine outward in the lateral direction Y, so-called lateral leakage. The top sheet 2, the back sheet 3, the absorbent body 4, the side sheet 5, and the elastic members 50 and 51 are joined to each other by a known joining means such as a hot-melt adhesive.

  The diaper 1 is a so-called unfolded disposable diaper. As shown in FIG. 1, a pair of fastening tapes 6 and 6 are provided on both side edges along the longitudinal direction X of the back side 1R of the diaper 1. . A fastening portion (not shown) made of a male member of a mechanical surface fastener is attached to the fastening tape 6. Moreover, the to-be-attached area | region 7 which consists of a female member of a mechanical hook-and-loop fastener is formed in the non-skin opposing surface of the belly side part 1F of the diaper 1. FIG. The to-be-attached region 7 is formed by attaching a female member of a mechanical hook-and-loop fastener to the non-skin facing surface of the back sheet 3 that forms the non-skin facing surface of the abdominal side portion 1F by a known joining means such as adhesive or heat seal. It is formed by joining and fixing, and the fastening portion of the fastening tape 6 can be detachably fastened.

  Hereinafter, the top sheet 2 will be described. In FIG.3 and FIG.4, a part of surface sheet 2 is expanded and shown. The surface sheet 2 is an embodiment of the nonwoven fabric of the present invention, and a plurality of convex portions 24 are scattered on one side, specifically, the skin facing surface 2a. Each of the plurality of convex portions 24 is hollow, and as shown in FIG. 4, the convex portion 24 is not filled with the material for forming the topsheet 2, and a space portion is formed.

  In the present embodiment, the top sheet 2 is configured to include a laminate 20 of the first nonwoven fabric 21 and the second nonwoven fabric 22. The convex portion 24 is formed on the first nonwoven fabric 21 and is not formed on the second nonwoven fabric 22. The second nonwoven fabric 22 is joined to the first nonwoven fabric 21 at a portion other than the convex portion 24, and a joint portion 23 of both nonwoven fabrics 21 and 22 is formed around the convex portion 24. The joint portion 23 is a so-called concave portion. The joining form of both the nonwoven fabrics 21 and 22 in the joining part 23 is not specifically limited, A well-known joining form, such as melt | fusion and joining by an adhesive agent, can be taken. For example, the form in which the nonwoven fabrics 21 and 22 are fused at the joint portion 23 can be formed by known embossing such as embossing or ultrasonic embossing with or without heat.

  That is, in the laminate 20, the first nonwoven fabric 21 and the second nonwoven fabric 22 are joined to form a joined portion 23, and the first nonwoven fabric 21 is away from the second nonwoven fabric 22 at a portion other than the joined portion 23. A plurality of hollow convex portions 24 projecting toward the skin side of the wearer are formed. And the surface sheet 2 comprised including the laminated body 20 has the 1st nonwoven fabric 21 located in the side near a wearer's skin, and the 2nd nonwoven fabric 22 located in the side far from a wearer's skin. Both the nonwoven fabrics 21 and 22 are integrated in the thickness direction by the joint portion 23, and a plurality of portions other than the joint portion 23 in the first nonwoven fabric 21 protrude in a convex shape on the opposite side to the second nonwoven fabric 22. And the some convex part 24 of the skin opposing surface 2a (surface on the opposite side to the opposing surface with the 2nd nonwoven fabric 22 in the 1st nonwoven fabric 21) is formed. The surface sheet 2 has a substantially flat non-skin facing surface 2b (a surface opposite to the surface facing the first nonwoven fabric 21 in the second nonwoven fabric 22), and the convex portion 24 and the joint 23 (on the skin facing surface 2a). Concavities and convexities are formed.

  In the present embodiment, each of the plurality of convex portions 24 has a circular shape in plan view, and has a substantially arc shape in a cross-sectional view along the thickness direction of the surface sheet 2 as shown in FIG. The width gradually decreases toward the skin side. The top 24a of the convex part 24 is rounded and not sharp. The plurality of convex portions 24 are regularly distributed in a scattered manner over the entire area of the skin facing surface 2a of the topsheet 2. More specifically, the plurality of convex portions 24 are arranged in the vertical direction X and the horizontal direction Y. It is arranged intermittently in both directions. Moreover, in this embodiment, the junction part 23 is distribute | arranged over the perimeter of each convex part 24, and the junction part 23 is continuing over the whole region of the skin opposing surface 2a of the surface sheet 2. As shown in FIG.

  In addition, the formation pattern of the convex part 24, ie, arrangement | positioning and form of the convex part 24, are not limited to the thing of illustration, Arbitrary things can be selected in the range which does not deviate from the meaning of this invention. For example, the plan view shape of the convex portion 24 can be an ellipse, a square, a rectangle, or the like other than the circular shape shown in the figure. The arrangement of the convex portions 24 can be a so-called staggered arrangement. In the staggered convex portions 24, a plurality of convex portions 24 are linearly arranged in a row at a predetermined interval in one direction (for example, the vertical direction X) to form a convex portion row, and the convex portion row is The protrusions 24 are intermittently arranged in a direction orthogonal to one direction (horizontal direction Y), and the protrusions 24 are shifted from each other in the adjacent protrusion array in the direction orthogonal to the one direction (transverse direction Y). .

  Further, the arrangement and form of the joint portion 23 are not limited to the formation pattern that is continuous over the entire area of the skin facing surface 2a of the topsheet 2 as shown in FIG. 3, and any one is selected without departing from the spirit of the present invention. can do. For example, the plurality of joint portions 23 are regularly dispersed and arranged in a scattered manner (for example, staggered arrangement) over the entire skin facing surface 2a of the top sheet 2, whereby the plurality of convex portions 24 are respectively joined to the plurality of joints. A plurality of joint portions 23 surrounded by the portion 23 and surrounding each convex portion 24 may be intermittently disposed around the convex portion 24. Since the forming material of the topsheet 2 is consolidated, the joint portion 23 formed by embossing is a high-density, rigid and hard portion compared to the peripheral portion (convex portion 24). The form in which a plurality of relatively hard joints 23 are formed in the shape of a dotted line is a form in which the joints 23 are continuous over the entire area of the skin facing surface 2a of the topsheet 2 as shown in FIG. In comparison, the flexibility of the topsheet 2 can be improved. The planar view shape of the plurality of joint portions 23 is not particularly limited, and may be appropriately selected from a circle, an ellipse, a square, a rectangle, and the like.

  As one of the characteristic configurations of the topsheet 2, as shown in FIGS. 3 and 4, the top portion 24 a of at least a part of the plurality of convex portions 24 has one opening 240 that communicates the inside and outside of the convex portion 24. The point which is formed individually is mentioned. The top part 24a of the convex part 24 is a part that directly contacts the skin of the wearer of the diaper 1 and is an important element that determines the touch and the cushion feeling, and the opening 240 is formed in the top part 24a. When the top portion 24a receives an external force, specifically, for example, when the wearer's skin touches the top portion 24a while the diaper 1 is worn, the top sheet 24a can move easily, and thereby the touch of the topsheet 2 and the cushioning feeling Can lead to improvement

As shown in FIG. 4, the apex 24a of the convex portion 24, that is, the opening 240 and its peripheral portion are portions located at the top when the convex portion 24 is divided into three equal parts in the height direction. In the divided convex portion 24, the lowermost portion is the base end portion 24c, and the space between the top portion 24a and the base end portion 24c is the middle abdominal portion 24b. In addition, to divide the convex portion of the surface sheet into three in the height direction in this way, a load of 1 gf / cm ² is applied to the convex portion from the top side in the height direction, and the low pressure state is reduced. The convex portion is observed using a microscope (VHX-1000 manufactured by Keyence Corporation).

  In the present embodiment, the opening 240 has a circular shape in plan view, but the shape in plan view of the opening 240 is not limited to a circle, and an arbitrary shape can be selected. For example, an elliptical shape may be used. The maximum length of the opening 240 in plan view is preferably 0.2 mm or more, more preferably 0.5 mm or more, from the viewpoint of the balance between the improvement effect of the touch and the feeling of cushion and the shape retention of the convex portion 24, and the like. And preferably it is 5.0 mm or less, More preferably, it is 2.0 mm or less. The maximum length of the opening 240 in plan view is the diameter when the shape of the opening 240 is circular, and is the length of the long axis when the shape is elliptic.

  The opening 240 may be formed only on a part of the plurality of convex portions 24 formed on the skin-facing surface 2a of the topsheet 2. However, the effect of improving the touch and the feeling of cushion is more reliably exhibited. From the viewpoint of making it, it is preferable that the plurality of convex portions 24 are formed on all. For example, when two kinds of convex portions 24 having different heights are formed on the skin facing surface 2a of the topsheet 2, the opening 240 is formed in at least the relatively high convex portion 24. It is preferable. In the present embodiment, the plurality of convex portions 24 have the same height, and an opening 240 is formed in all of them.

  In the present embodiment, an opening 240 that is a through hole penetrating through the first nonwoven fabric 21 in the thickness direction is formed only in the first nonwoven fabric 21, and a through hole penetrating through the second nonwoven fabric 22 in the thickness direction is formed. Not. The term “through hole” as used herein means a purposely formed through hole and does not include a micropore structure that is inherently contained in a nonwoven fabric, such as an interfiber gap. In other words, in the present embodiment, in the laminate 20 constituting the top sheet 2, through-holes are formed in the sheet (first nonwoven fabric 21) that is relatively close to the wearer's skin, but the wearer's skin No through hole is formed in the sheet (second nonwoven fabric 22) relatively far from the sheet. On the other hand, in the composite sheet described in Patent Document 2, through-holes are formed in a sheet relatively distant from the wearer's skin among the non-woven fabric laminate constituting the composite sheet. Contrast with this embodiment with respect to the formation site. Such a difference regarding the through hole between the top sheet 2 of the present embodiment and the composite sheet described in Patent Document 2 is mainly caused by a difference in function of the through hole. That is, the through-hole in the composite sheet described in Patent Document 2 is mainly for improving the liquid flow and facilitating the transfer of the liquid to the absorber disposed on the side farther from the wearer's skin than the composite sheet. Therefore, a through hole is formed in a sheet relatively far from the wearer's skin. On the other hand, the opening 240 in the topsheet 2 of the present embodiment is for making the convex portion 24 easy to move by an external force from the viewpoint of improving the touch and the cushion feeling, as described above. It is necessary to form the convex portion 24 itself (a sheet relatively close to the wearer's skin). Moreover, in the diaper 1 of this embodiment, when the through-hole which penetrates this 2nd nonwoven fabric in the thickness direction in the position corresponding to the opening 240 in the 2nd nonwoven fabric 22 is formed in the thickness direction of the surface sheet 2 When the entire through-hole consisting of the through-hole and the opening 240 is formed, the core wrap sheet 41 having a poor touch is exposed from the entire through-hole to the skin-facing surface, and the touch of the top sheet 2 may be impaired. Therefore, in the present embodiment, it is more preferable not to form a through hole in the second nonwoven fabric 22.

  As described above, by forming the opening 240 in the top 24a of the convex portion 24 existing on the skin facing surface 2a of the topsheet 2, it can lead to improvement of the touch and cushion feeling of the topsheet 2, but only with such a configuration. A sufficient effect cannot be obtained. In order to improve the feel and cushion feeling of the topsheet 2, in the convex portion 24 in which the opening 240 is formed, the opening 240 is excluded from the constituent fibers existing in the top 24 a (that is, the opening 240 and its peripheral portion). It is necessary that the distance between the fibers in the periphery of the opening is equal to or greater than the distance between the fibers of the constituent fibers existing in the portion other than the top 24a (that is, the middle abdomen 24b and the base end 24c).

  That is, in order to give the top sheet 2 a high level of touch and a feeling of cushion, in addition to forming the opening 240 in the top 24a of the protrusion 24, the protrusion 24 having the opening 240 is further formed. It is necessary to make the distance between the fibers of the existing constituent fibers equal in the entire convex portion 24 or to have the longest top portion 24a.

  A particularly preferred form is a form in which the inter-fiber distance of the constituent fibers in the convex part 24 in which the opening 240 is formed is the longest at the top part 24a and gradually decreases from the opening 240 in the height direction of the convex part 24. . That is, in the convex part 24 in which the opening 240 is formed, it is particularly preferable that the magnitude relationship of the top part 24a> the middle part 24b> the base end part 24c is established with respect to the inter-fiber distance of the constituent fibers.

  In addition, in this way, in order to maximize the distance between the fibers of the constituent fibers existing in the top 24a of the convex portion 24 where the opening 240 is formed, that is, the opening 240 and its peripheral portion, in the convex portion 24, It is important that the distance between the fibers at the top 24a is not too short, that is, the constituent fibers are not highly dense at the top 24a. From this point of view, it is preferable not to employ a method involving softening and melting of the constituent fibers, for example, a method involving heating of the top 24a, as a method for forming the opening 240. For example, when the opening 240 is formed in the top 24a of the convex portion 24 by embossing with known heat, the opening edge portion of the opening 240 thus formed is softened and melted by the embossing. Since the fiber fusion part is formed, the inter-fiber distance of the constituent fibers existing in the top part 24a is extremely short, or substantially the whole of the top part 24a becomes the fusion part, and the inter-fiber gap is substantially May not exist. In short, it is preferable that the convex part 24 does not have a fusion part of the constituent fibers at least at the top part 24a, preferably the whole convex part 24.

  A preferable method for forming the opening 240 is a non-heating method that does not involve heating of the top 24a. Specifically, for example, i) physically pressing a portion where the opening 240 is to be formed, A method of forming the opening 240 by further separating existing constituent fibers, and ii) a method of cutting a site where the opening 240 is to be formed. Examples of the pressing means of i) include a pressing tool such as a pin or punching. , Water flow, air blowing. For example, when the manufacturing method of the 1st nonwoven fabric 21 has the process of forming a fiber web by the well-known card | curd method and performing heat processing, such as spraying a hot air on this fiber web, and making this into a nonwoven fabric, before this heat processing The opening 240 may be formed by performing the above i) on the fiber web, or by performing the above ii) on the fiber web after the heat treatment, that is, the first nonwoven fabric 21. 240 may be formed.

  The interfiber distance of each part of the surface sheet 2 is measured by the following method. In addition, when measuring the interfiber distance of a part of the convex part 24 (the top part 24a, the middle abdomen part 24b, the base end part 24c), the interfiber distance is measured by the following method for the part, and the average value thereof is calculated. The distance between some of the fibers is used. In addition, when cutting the nonwoven fabric to be measured for the measurement of the interfiber distance, in order to minimize the change in the interfiber distance due to the cutting, the nonwoven fabric to be measured is frozen in advance with liquid nitrogen, Cut the frozen nonwoven fabric with a razor blade.

<Measurement method of distance between fibers>
The distance between fibers was measured according to the procedure described below according to “Measurement of fiber space diameter” described in JP-A-5-285172. Constituent fibers existing in the measurement target portion of the surface sheet, that is, constituent fibers existing in the periphery of the opening excluding the opening 240 among the top 24a (that is, the opening 240 and its peripheral portion), and the middle abdomen 24b and the base end Each of the constituent fibers present in the part 24c is used as a sample, and a 100 × magnified image of this sample is obtained by a microscope (VHX-1000 manufactured by Keyence Corporation). Based on the magnified image, image analysis measurement software (manufactured by Media Cybernetics) Image-Pro Plus “The Proven Solution” Ver. 4.5.12), the outside of the fiber in focus is extracted, and the surface formed there is used as the fiber space. The enlarged image was read with a scanner or the like, and the area occupied by the fiber space was determined. Five locations of the sample are selected, and the fiber space diameter (r) according to the following formulas (1) and (2) from the area per fiber space [fiber space area (average value)] in the selected range. ) And the fiber space diameter (r) was defined as the inter-fiber distance. In the following formula, A is the fiber space area (average value), Ai is the measured fiber space area, and N is the measured number.

  The nonwoven fabric satisfying the magnitude relationship of the inter-fiber distances of the constituent fibers in each part of the convex part 24 (the top part 24a, the middle abdominal part 24b, and the base end part 24c) It is obtained by forming apertures by the non-heating method. When the uneven nonwoven fabric before the opening is formed is a laminated structure such as the surface sheet 2 of the present embodiment, for example, a three-dimensional shaping method using embossing compression processing, specifically, for example, In the case where the composite sheet can be produced by the method for producing a composite sheet described in 2015-112343 and the uneven nonwoven fabric has a single-layer structure (see FIG. 5) described later, for example, described in JP 2012-144835 A It can be manufactured by the method for manufacturing a nonwoven fabric.

In the convex part 24 in which the opening 240 is formed, the ratio of the interfiber distance La of the apex 24a and the interfiber distance Lb of the middle abdomen 24b is preferably 1.0 or more, more preferably 1. 1 or more, preferably 5.0 or less, more preferably 1.5 or less.
In the convex part 24 in which the opening 240 is formed, the ratio of the inter-fiber distance La of the top part 24a and the inter-fiber distance Lc of the base end part 24c is preferably 1.0 or more, more preferably 1 as La / Lc. .2 or more, and preferably 10 or less, more preferably 1.8 or less.
In the convex portion 24 in which the opening 240 is formed, the ratio between the interfiber distance Lb of the middle abdominal portion 24b and the interfiber distance Lc of the base end portion 24c is preferably 1.0 or more, more preferably, as Lb / Lc. 1.1 or more, and preferably 8.0 or less, more preferably 1.5 or less.

In the convex part 24 in which the opening 240 is formed, the inter-fiber distance La of the top part 24a is 50 μm or more, more preferably 60 μm or more, and preferably 150 μm or less, more preferably 120 μm or less.
In the convex part 24 in which the opening 240 is formed, the interfiber distance Lb of the middle abdominal part 24b is preferably 30 μm or more, more preferably 50 μm or more, and preferably 120 μm or less, more preferably 100 μm or less.
In the convex part 24 in which the opening 240 is formed, the inter-fiber distance Lc of the base end part 24c is preferably 15 μm or more, more preferably 30 μm or more, and preferably 90 μm or less, more preferably 70 μm or less.

In addition, from the viewpoint of more surely exhibiting the operational effects due to the characteristic configuration of the convex portion 24 described above, it is preferable to set the dimensions and the like of each portion of the topsheet 2 as follows.
The height 24T (see FIG. 4) of the convex portion 24 is preferably 0.8 mm or more, more preferably 1.4 mm or more, and preferably 10 mm or less, more preferably 5.0 mm or less.
The maximum length 24L (see FIG. 4) of the convex portion 24 in plan view is preferably 1.5 mm or more, more preferably 2.0 mm or more, and preferably 10 mm or less, more preferably 7.0 mm or less.
When an area having a square shape of 50 mm length and 50 mm width in plan view is arbitrarily selected from the skin facing surface 2a of the topsheet 2, the total number of convex portions 24 existing in the arbitrary area is preferably 9 or more, more preferably 25. The number is at least 1, and preferably at most 900, more preferably at most 400.

The forming material of the surface sheet 2 will be described. As the first nonwoven fabric 21 and the second nonwoven fabric 22 constituting the surface sheet 2, for example, an air-through nonwoven fabric, a spunbond nonwoven fabric, a spunlace nonwoven fabric, a melt blown nonwoven fabric, a resin bond nonwoven fabric, and a needle, respectively. A punch nonwoven fabric or the like can be used. Among these, the air-through nonwoven fabric is preferably used in the present invention because the touch and the cushion feeling are better than those of other nonwoven fabrics produced by other methods. The basis weights of both nonwoven fabrics 21 and 22 are not particularly limited, but each is preferably 8 g / m ² or more, more preferably 15 g / m ² or more, and preferably 100 g / m ² or less, more preferably 70 g / m ^2. m ² or less.

  As the constituent fibers of both nonwoven fabrics 21 and 22, fibers (heat-bonded fibers) made of various thermoplastic resins can be used. Examples of the thermoplastic resin include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate; polyamides such as nylon 6 and nylon 66; polyacrylic acid, polymethacrylic acid alkyl ester, polyvinyl chloride, and polyvinylidene chloride. These resins can be used alone or in combination of two or more. The heat-fusible fiber may be a short fiber or a long fiber, and may be hydrophilic or water repellent. Further, core-sheath type or side-by-side type composite fibers, split fibers, irregular cross-section fibers, heat-shrinkable fibers, and the like can also be used. These fibers can be used alone or in combination of two or more. Moreover, both nonwoven fabrics 21 and 22 may be mutually the same compositionally, and may differ. Here, compositionally the same means that both forming materials and the content thereof are the same, and the appearance elements such as the dimensions of each part and the shape in plan view are not different.

  The surface sheet 2 including the laminate 20 of the first nonwoven fabric 21 and the second nonwoven fabric 22 can be manufactured, for example, according to the composite sheet manufacturing method described in JP-A-2015-112343. . Specifically, for example, the belt-shaped first nonwoven fabric 21 is supplied between a first roll and a second roll whose peripheral surfaces are meshed with each other, and the first nonwoven fabric 21 is deformed into an uneven shape. After that, the first nonwoven fabric 21 is moved from the meshing portion along the peripheral surface portion of the first roll, and then the second nonwoven fabric 22 is supplied to be superimposed on the first nonwoven fabric 21 to supply both nonwoven fabrics 21 and 22. Between the convex part and heat roll in the first roll, the joint part 23 is formed by pressing under heating, and both nonwoven fabrics 21 and 22 are joined and integrated. When the first nonwoven fabric 21 is deformed into an uneven shape by being engaged with the meshing portion of the first roll and the second roll, the first nonwoven fabric 21 is sucked toward the inside of the roll, and the first nonwoven fabric 21 It is preferable to promote the deformation to the uneven shape. Both nonwoven fabrics 21 and 22 can be manufactured according to a known method for manufacturing nonwoven fabrics.

  FIG. 5 shows a surface sheet 25 which is another embodiment of the nonwoven fabric of the present invention. About the surface sheet 25 shown in FIG. 5, the component different from the surface sheet 2 mentioned above is mainly demonstrated, the same component is attached | subjected the same code | symbol and description is abbreviate | omitted. The description of the surface sheet 2 is applied as appropriate to components that are not specifically described for the surface sheet 25.

  The surface sheet 25 shown in FIG. 5 has a single-layer structure, is composed of a single nonwoven fabric, and can be manufactured according to the nonwoven fabric manufacturing method described in JP2012-144835A. Specifically, the fiber web (card web) before being fused is supplied from the card machine to the web shaping device so as to have a predetermined thickness. In the web shaping apparatus, first, warm air is supplied to fix the fiber web on a large number of protrusions on the pedestal of the web shaping apparatus. Next, hot air is blown against the fiber web on the pedestal at a temperature at which each constituent fiber of the fiber web can be appropriately fused, and the fiber web is shaped along the protrusions on the pedestal. The surface sheet 25 is produced by fusing the constituent fibers. The topsheet 25 produced by such a method does not have a joint between a plurality of nonwoven fabrics, like the joint 23 in the topsheet 2 (see FIG. 2). The formation pattern of the convex part 24 in the surface sheet 25 is the same as that in the surface sheet 2, and the skin facing surface 2 a of the surface sheet 25 has a concave part (non-convex part) 26 over the entire circumference of each of the plurality of convex parts 24. The recess 26 is continuous over the entire skin facing surface 2a. Further, the convex portion 24 is not formed on the non-skin facing surface 2b of the topsheet 25, and a portion corresponding to the convex portion 24 protrudes toward the skin facing surface 2a side to form a hollow portion of the convex portion 24. ing. In addition, in the surface sheet 25, the formation pattern of the convex part 24 and the recessed part 26 is not limited to the thing of illustration, In the range which does not deviate from the meaning of this invention, arbitrary things can be selected.

Although the present invention has been described above, the present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention. For example, in the nonwoven fabric of this invention, the convex part may be formed in both surfaces. In addition, when a convex part is formed on the non-skin facing surface of the nonwoven fabric, the opening according to the present invention is formed at the top of the convex part, that is, the convex part is easily moved by an external force, thereby improving the touch and cushion feeling of the nonwoven fabric. There is no need to form apertures that can be made.
Moreover, in the diaper 1, it is between the surface sheet 2 and the absorber 4 (core wrap sheet | seat 41) in order to prevent the transfer of the excretion liquid from the absorptive core 40 to a wearer's skin side (so-called liquid return). In addition, a fluid-permeable body fluid backflow prevention layer called a sublayer may be interposed.
In addition, the absorbent article of the present invention is not limited to the deployable disposable diaper as in the above-described embodiment, and a wide range of articles used for absorbing bodily fluids (urine, menstrual blood, loose stool, sweat, etc.) discharged from the human body Also included are pants-type disposable diapers, sanitary napkins, sanitary shorts, and the like.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to such examples.

[Example 1]
A non-woven fabric made of a laminate of a first non-woven fabric and a second non-woven fabric similar to the topsheet 2 shown in FIGS. The formation pattern of the convex part and the junction part (concave part) in the nonwoven fabric of Example 1 is similar to the composite sheet described in Patent Document 2, and specifically, the convex part has a flat ridgeline as a whole. A rectangular parallelepiped or a truncated quadrangular pyramid is formed, both the convex portion and the joint portion (concave portion) are rectangular in plan view, and both the convex portion and the joint portion (concave portion) are staggered.
As the first nonwoven fabric, a card web having a basis weight of 18 g / m ² was manufactured by a card method using a heat-fusible conjugate fiber as a raw material. The card web is pressed with a support having a plurality of protrusions described in Patent Document 1 to form regularly arranged holes and subjected to air-through hot air treatment to heat the intersection of the composite fibers. The 1st nonwoven fabric which was made to fuse | melt and formed the regular opening was manufactured. The raw composite fiber was a core-sheath type composite fiber having polyethylene terephthalate (PET) as a core component and polyethylene (PE) as a sheath component, and a fiber having a fineness of 2.3 dtex was used.
As the second nonwoven fabric, an uneven nonwoven fabric having the same configuration as the first nonwoven fabric was used except that the convex portions did not have openings.
Using the first nonwoven fabric and the second nonwoven fabric, both the nonwoven fabrics were joined and integrated by embossing according to the method for producing a composite sheet described in Patent Document 2, and the surface sheet of Example 1 was produced. In addition, the embossing pitch was adjusted so that the opening of the first nonwoven fabric was positioned at the apex of the convex portion.

[Example 2]
A non-woven fabric having a single layer structure similar to that of the surface sheet 25 shown in FIG. Specifically, it manufactured according to the manufacturing method of the nonwoven fabric described in Unexamined-Japanese-Patent No. 2012-144835 using the heat-fusible conjugate fiber.

[Comparative Example 1]
A non-woven fabric having a two-layer structure was produced in the same manner as in Example 1 except that no openings were formed in the convex portions of the first nonwoven fabric, and Comparative Example 1 was obtained.

[Comparative Example 2]
As a method for forming openings in the convex portions of the first nonwoven fabric, a nonwoven fabric having a two-layer structure was produced in the same manner as in Example 1 except that melt opening by hot embossing was adopted, and Comparative Example 2 was obtained.

[Comparative Example 3]
A non-woven fabric having a single-layer structure was produced in the same manner as in Example 2 except that no openings were formed in the convex portions of the first nonwoven fabric, and Comparative Example 3 was obtained.

〔Evaluation test〕
About the nonwoven fabric of each Example and a comparative example, while measuring the interfiber distance of the constituent fiber in each part of a convex part with the said method, three panelists (adult man and woman) evaluated the touch of the convex part formation surface in this nonwoven fabric. I got it. The evaluation of such a touch is a 6-point perfect score (the highest evaluation is 6 points, the lowest evaluation is 1 point), and Comparative Example 1 is used for the non-woven fabric of the two-layer structure, and Comparative Example 3 is used for the non-woven fabric of the single-layer structure. Each was performed as a standard (3 points for the standard nonwoven fabric). The results (average score of three panelists for the touch) are shown in Table 1 below.

1 disposable diaper (absorbent article)
1F Abdominal side 1M Crotch 1R Back side 2,25 Surface sheet (nonwoven fabric)
DESCRIPTION OF SYMBOLS 20 Laminated body 21 1st nonwoven fabric 22 2nd nonwoven fabric 23 Joint part 24 Convex part 24a Top part of convex part 24b Middle part of convex part 24c Base end part of convex part 240 Opening 3 Back surface sheet 4 Absorber 40 Absorbent core 41 Core Wrap sheet 5 Side sheet 6 Fastening tape 7 Fastening area X Vertical direction Y Horizontal direction

Claims (5)

A plurality of hollow convex portions are scattered on one side, and at the top of at least a part of the plurality of convex portions, an opening that communicates the inside and outside of the convex portions is formed,
In the said convex part in which the said hole was formed, the nonwoven fabric whose interfiber distance of the constituent fiber which exists in the said top part is more than the interfiber distance of the constituent fiber which exists in parts other than this top part.   2. The nonwoven fabric according to claim 1, wherein the inter-fiber distance of the constituent fibers in the convex portion in which the opening is formed is longest at the top portion and gradually decreases from the opening in the height direction of the convex portion. It is comprised including the laminated body of a 1st nonwoven fabric and a 2nd nonwoven fabric,
The said convex part is formed in the said 1st nonwoven fabric, is not formed in the said 2nd nonwoven fabric, This 2nd nonwoven fabric is joined to this 1st nonwoven fabric in parts other than this convex part. The nonwoven fabric according to 1 or 2.   The nonwoven fabric according to claim 3, wherein the second nonwoven fabric has no through-hole penetrating the second nonwoven fabric in the thickness direction.   It is an absorptive article which comprises an absorber and a surface sheet distribute | arranged to the skin opposing surface side of this absorber, Comprising: The said surface sheet is the nonwoven fabric as described in any one of Claims 1-4. Goods.

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