JP5161499B2 - Absorbent articles - Google Patents

Description

  The present invention relates to an absorbent article, and more particularly to an absorbent article characterized by the rigidity of front and rear flaps.

  Conventionally, sanitary napkins, panty liners, urine collecting pads, and the like have been used as absorbent articles for absorbing excrement such as body fluids. These absorbent articles include an absorbent body that absorbs and retains body fluids, a liquid-permeable surface sheet that covers the surface of the absorbent body on the skin contact surface side, and a non-skin contact that corresponds to the clothing side of the absorbent body. A liquid-impermeable back sheet covering the back surface on the contact surface side. And the part of the surface sheet and back sheet which go outside from the absorber edge part of the longitudinal direction in this absorbent article is called front-back flap part. In the front and rear flaps, there may be formed a joining region for joining the top sheet and the back sheet with an emboss seal or the like at the outer periphery of the absorbent article.

As an example of the front and rear flap portions, for example, in Patent Document 1 below, a body fluid permeation made of a bulky nonwoven fabric is interposed between the top sheet and the absorbent body and extends at least from the front end portion to the rear end portion of the product. A body fluid-absorbing article in which the front and rear end parts of the second sheet are sandwiched between the top sheet and the back sheet and are thermocompression bonded and the flap part is integrated. A body fluid-absorbing article in which a second sheet is previously consolidated is disclosed.
JP 2004-195709 A

  In general, in an absorbent article that is attached to an undergarment and worn, if the above-mentioned front and rear flaps are too flexible, it is bent in the longitudinal direction starting from the end of the absorber during the process of being worn or affixed to the undergarment and pulled up. May occur. In particular, the front and rear flaps are mainly bent to the skin surface side, but in this case, the absorption surface is covered, so that leakage is induced, and the edge of the front and rear flaps hits the skin, giving a foreign body feeling. May end up. Further, even when bent to the opposite underwear side, the thickness is partially increased, giving a foreign object feeling.

  Moreover, in an absorbent article provided with said joining area | region and the bodily fluid absorbent article of patent document 1, when a joining area | region and thermocompression bonding are formed with an embossing pattern, or the boundary of an embossed part and a non-embossed part, or Since the bending rigidity further decreases in the longitudinal direction starting from the non-embossed point, the front and rear flaps are easily bent.

  It is also conceivable that the emboss pattern is a linear emboss pattern or a planar flat pattern extending in the longitudinal direction. In this case, since there is a portion where the density continuously increases in the longitudinal direction, the bending rigidity in the longitudinal direction is higher than before embossing, but at the same time the thickness is reduced, so that sufficient bending rigidity cannot be obtained. .

  In order to achieve the above-mentioned object, the present inventors have found that leakage and foreign matter sensation can be effectively prevented by differentiating the bending rigidity in the longitudinal direction and the width direction at the front and rear flaps, and to complete the present invention. It came. That is, the present invention provides the following.

(1) A vertically long shape comprising at least a part of a liquid-permeable top sheet, a back sheet having a liquid-impermeable sheet, and an absorber disposed between the top sheet and the back sheet. An absorbent article,
Joining regions for joining the top sheet and the back sheet are formed on the outer peripheral edges at both ends in the longitudinal direction of the absorbent article,
In at least one of the flap rigid regions that reach the inner peripheral edge of the joining region that faces the both end portions from the both end portions of the absorbent body in the longitudinal direction of the absorbent article,
The absorbent article whose bending rigidity value in the longitudinal direction is larger than the bending rigidity value in the width direction of the absorbent article.

(2) The top sheet in at least one of the flap rigidity regions is
It is formed of a nonwoven fabric having a plurality of grooves and convex portions alternately formed so as to extend in the longitudinal direction,
The side edge regions of each of the plurality of convex portions are fiber orientations along the longitudinal direction,
The fiber density of the said side edge area | region is an absorbent article as described in (1) higher than the average fiber density of the said convex-shaped part.

(3) The bending stiffness value in the longitudinal direction is 0.15 gf · cm ² / cm or more and 1.0 gf · cm ² / cm or less as a bending stiffness value B according to the KES method, as described in (1) or (2) Absorbent article.

  ADVANTAGE OF THE INVENTION According to this invention, it can prevent bending in a longitudinal direction from an absorber edge part in the process of affixing and pulling up on underwear. At the same time, it can be easily bent in the width direction, and can easily follow the curvature of the body or shorts in the width direction, so that the foreign object feeling can be reduced and the fit can be improved.

Hereinafter, as an absorbent article according to the present invention, a sanitary napkin will be described as an example. FIG. 1 is a plan view of an absorbent article according to an embodiment of the present invention. FIG. 2 is a cross-sectional perspective view taken along line Z ₁ -Z ₁ in FIG.

<Overall configuration>
As shown in FIG. 1, the absorbent article 1 according to the present invention is formed in a vertically long shape as a whole. The absorbent article 1 includes a top sheet portion 2 that is at least partially liquid permeable, a back sheet portion 3 that serves as a leak-proof layer, and an absorbent body 4 that absorbs and holds liquid such as excrement.

  The top sheet portion 2 and a back sheet 30 to be described later constituting the back sheet portion 3 are joined by a hot embossing process along the outer peripheral edge of the absorbent article 1, and a seal portion 50 corresponding to the joining region of the present invention. Is formed. In this embodiment, the seal part 50 includes a plurality of pressure-bonding parts 51 and a non-pressure-bonding part 52 formed by a heat embossing process.

  As shown in FIGS. 1 and 2, the surface sheet portion 2 is disposed along the longitudinal direction LD on both sides of the surface sheet 20 in the width direction WD and the surface sheet 20 disposed in the center of the absorbent article 1 in the width direction WD. Side sheets 21 and 21 and the second sheet 22 disposed between the top sheet 20 and the absorber 4.

  The top sheet 20 is a liquid-permeable sheet, is disposed so as to cover the absorbent body 4 and the second sheet 22, and is a sheet that comes into contact with the body in the absorbent article 1. Permeate to the side. And the surface sheet 20 is the nonwoven fabric which has the some groove part 26 and the convex-shaped part 27 which are formed so that it may extend in a longitudinal direction (LD direction). The top sheet 20 will be described later in detail.

  The top sheet 20 is provided with a circumferential leak-proof region 25 in a region where the absorber 4 is disposed. The leak-proof area 25 is an emboss pattern by, for example, embossing, and a large pressing force is applied in the thickness direction TD of the absorbent article 1 so that the thickness of the absorbent body 4 is reduced.

  Side sheets 21 and 21 are disposed on both sides of the top sheet 20 in the width direction WD along the longitudinal direction LD of the absorbent article 1. The side sheets 21 and 21 are in a state in which a part of the absorbent article 1 in the longitudinal direction LD protrudes outward in the width direction WD, and form wings 5L and 5R together with the back sheet 30 described later.

  The side sheets 21 and 21 are joined to the top sheet 20 by embossed portions and hot melt adhesives formed at substantially equal intervals along the longitudinal direction LD on both sides of the top sheet 20 in the width direction WD. In this embodiment, design embosses 21a and 21b simulating floral patterns and leaves are provided on the side sheets 21 and 21, and the side sheets 21 and 21 and the top sheet 20 are formed by the design embosses 21a and 21b. It is joined.

  The second sheet 22 is disposed between the topsheet 20 and the absorbent body 4 in the region where the absorbent body 4 of the absorbent article 1 is disposed, and as shown in FIG. 2 near the outer periphery of the absorbent article 1. The sheet is disposed between the top sheet 20 and the back sheet 30. The second sheet 22 is arranged in a state where the liquid-permeable sheet is folded in half. The second sheet 22 can be formed of the same material as the top sheet 20, but is preferably formed so as to have a higher density than the top sheet 20. Since the second sheet 22 has a higher density than the top sheet 20, the liquid transfer from the top sheet 20 can be enhanced.

  The thickness of the second sheet 22 is preferably 0.3 mm or more, more preferably in the range of 0.3 to 3.0 mm, and particularly preferably in the range of 0.6 to 2.5 mm. If it is smaller than 0.3 mm, the front and rear flaps are bent, and if it exceeds 3.0 mm, a foreign object sensation is given. The basis weight of the second sheet 22 is preferably 15 gsm or more, more preferably 15 to 60 gsm, and particularly preferably 20 to 50 gsm. If it is smaller than 15 gsm, the front and rear flaps are bent, and if it exceeds 60 gsm, not only a foreign body sensation is given, but also the fluid permeability is impaired.

  The length in the longitudinal direction LD of the top sheet 20 and the side sheet 21 is formed to be larger than the length in the longitudinal direction LD of the absorber 4. Further, the length of the top sheet 20 in the width direction WD is formed to be equal to or greater than the length of the absorber 4 in the width direction WD.

  The back sheet portion 3 constitutes a leak-proof layer in the absorbent article 1. The back sheet portion 3 includes a liquid-impermeable back sheet 30, a slip stopper (not shown) that fixes the absorbent article 1, and wing slip stoppers 32 </ b> L and 32 </ b> R.

  The absorbent body 4 is disposed in the center of the absorbent article 1 in the width direction WD, and absorbs and holds liquid such as excreta excreted from the body. The size of the absorber 4 is formed so that the length in the longitudinal direction LD and the width direction WD is smaller than the surface sheet portion 2 described later. As a result, the absorbent body 4 is not disposed in the vicinity of the front edge 8 and the rear edge 9 of the absorbent article 1, and the outer side of the longitudinal direction LD is in a state where the top sheet 20, the second sheet 22, and the back sheet 30 are sequentially laminated. It will be in the state extended to. And the seal | sticker part 50 is formed so that the outer periphery of the absorbent article 1 may be followed in this laminated state. As a result, the front flap part 55 is formed from the front edge 8 side end part of the both ends of the absorbent body 4 in the longitudinal direction to the front edge 8, and rearward from the rear edge 9 side end part of the both ends of the absorbent body 4 in the longitudinal direction. A rear flap portion 56 is formed over the edge 9. The bending rigidity of the front and rear flap portions 55 and 56 will be described in detail later.

  In addition, the conventionally well-known thing can each be used suitably for the material of each member which comprises said absorbent article 1, a shape, a magnitude | size, etc., respectively.

<Surface sheet>
As the surface sheet 20, it is possible to use a sheet in which a plurality of groove portions 26 are formed in parallel at substantially equal intervals on one side of the nonwoven fabric, and a plurality of convex portions 27 are formed between the plurality of groove portions 26. Each of the plurality of groove portions 26 is preferably formed with a plurality of openings 28 at predetermined intervals by a connecting portion 29.

  Such a nonwoven fabric having a plurality of groove portions 26 and a plurality of convex portions 27 and having a plurality of openings 28 formed in each of the groove portions 26 is formed by using, for example, a support member 100 as shown in FIG. can do. The support member 100 includes a net-like first support member 110 and plate-like second support members 120 that are regularly arranged at predetermined intervals in a direction orthogonal to the groove 26.

  A fiber web which is a fiber assembly is supported from the lower surface side by a support member 100 having air permeability, and a gas (for example, an air flow) is sprayed along the positions of the plurality of groove portions 26 from the upper surface side to The groove part 26 and the convex part 27 are formed by moving the fiber which comprises. At the same time, the second support member 120 alternately forms the connecting portions 29 and the opening portions 28 in the groove portions 26. This fiber assembly is in the form of a sheet and has a degree of freedom in which the fibers can move in the fiber assembly. The fiber orientation, fiber density or basis weight of the fiber is appropriately adjusted. Since the groove part 26 is formed in the surface sheet 20 and the opening part 28 is provided in the groove part, the absorbent article 1 having good liquid permeability can be obtained.

  In the present invention, the support member 100 may be only the first support member 110. In this case, the opening portion 28 is not formed in the groove portion 26 of the topsheet 20, and only the connecting portion 29 is provided.

  In this way, by arranging and rearranging the fibers by spraying air flow, each of the plurality of convex portions 27 is between the side edge region and the central region having a larger thickness than the side edge region. And have. The side edge region has a fiber density that is substantially uniform in the thickness direction TD of the nonwoven fabric and has a fiber density that is higher than the average fiber density in the entire convex portion 27 that combines the side edge region and the central region. The center region has a fiber density that is substantially uniform in the thickness direction TD of the nonwoven fabric and has a fiber density that is lower than the average fiber density in the entire convex portion 27 that combines the side edge region and the center region.

  According to the said structure, the fiber which comprises the side edge area | region of the convex-shaped part 27 rearranges and orientates in a longitudinal direction, and its density is also high. Therefore, the bending rigidity in the longitudinal direction is increased by the bulkiness of the side edge region and the convex portion 27. For this reason, even when an external pressure is applied to the convex portion 27, the central region is supported by the highly rigid side edge regions located on both sides of the central region. Thereby, the plurality of convex portions 27 are not easily crushed by external pressure or the like. Therefore, this side edge region increases the bending rigidity in the longitudinal direction. Further, not only the bending rigidity is increased due to the bulkiness of the convex portion, but even if the convex portion is bent, it is easy to return to the original shape due to the bulk recoverability of the convex portion. Accordingly, when the front and rear flaps are bent, the wearer can easily repair the flap and can naturally return to the original shape during wearing.

  On the other hand, the groove portion 26 has a lower basis weight than the convex portion 27 by spraying air flow to arrange and rearrange the fibers. For this reason, it can bend easily in the width direction starting from the groove 26. Thereby, since it becomes easy to follow the curvature to the width direction of a body or shorts, a foreign material feeling can be reduced and fit property can be improved.

  In addition, since the fibers are arranged and rearranged by blowing an air flow, a fiber web formed by a card method using relatively long fibers is suitable. In order to form a non-woven fabric while maintaining its shape after forming a groove (unevenness) or the like by a plurality of air flows, a through air method in which thermoplastic fibers are thermally fused by oven treatment (heat treatment) is preferable. As a fiber suitable for this production method, it is preferable to use a fiber having a core-sheath structure or a side-by-side structure in order to heat-bond the intersections of the fibers. It is preferable that it is comprised with the fiber of this. In particular, it is preferable to use a core-sheath composite fiber made of polyethylene terephthalate and polyethylene or a core-sheath composite fiber made of polypropylene and polyethylene. These fibers can be used alone or in combination of two or more. The fiber length is preferably 20 to 100 mm, particularly 35 to 65 mm.

  As thickness of the surface sheet 20, 0.6 mm or more is preferable, the range of 0.6-3.0 mm is more preferable, the range of 0.7-2.5 mm is especially preferable, The range of 1.0-3.0 mm Is most preferred. If it is smaller than 0.6 mm, the front and rear flaps are bent, and if it exceeds 3.0 mm, a foreign object sensation is given. The basis weight of the top sheet is preferably 15 gsm or more, more preferably 15 to 60 gsm, and particularly preferably 20 to 50 gsm. If it is smaller than 15 gsm, the front and rear flaps are bent, and if it exceeds 60 gsm, not only a foreign body sensation is given, but also the fluid permeability is impaired.

<Bending stiffness in the flap stiffness region>
As shown in FIG. 1, when the above nonwoven fabric is used as the top sheet 20, the extending direction of the groove 26 is used so as to coincide with the longitudinal direction LD of the absorbent article 1. Thereby, as will be described later, the bending rigidity in the longitudinal direction LD of the front and rear flaps is increased, and the flexibility in the width direction WD can be maintained.

The front flap portion 55 includes a seal portion 50 on the front edge 8 side (Y ₁ in FIG. 1 in terms of the width of the region) and a flap rigidity region 60 (region region) from the inner peripheral edge to the opposite edge portion of the absorber 4. Speaking of the width, this is a region obtained by combining X ₁ ) in FIG. The rear flap portion 56 includes a seal portion 50 (Y ₂ in FIG. 1 in terms of the width of the region) on the rear edge 9 side, and a flap rigidity region 60 (region of the region) from the inner peripheral edge to the edge of the opposite absorbent body 4. Speaking of the width, this is a region obtained by combining X ₂ ) in FIG. The front flap portion 55 and the rear flap portion 56 are collectively referred to as a front / rear flap portion.

In the present invention, the bending rigidity value in the longitudinal direction LD is larger than the bending rigidity value in the width direction WD in the bending rigidity of the flap rigidity region 60 constituting the front and rear flap portions. Since the bending rigidity value in the longitudinal direction LD is high, it can be prevented from being bent in the longitudinal direction starting from the end of the absorber during the process of being worn or affixed to the undergarment and pulled up. Can be resolved. At the same time, since the bending rigidity value in the width direction WD is low, it can be easily bent in the width direction, and it is easy to follow the bending in the width direction of the body and shorts, thus reducing the feeling of foreign matter, Fit can be improved. Speaking of specific numerical values, the difference between the bending stiffness value in the longitudinal direction and the bending stiffness value in the width direction is preferably 0.05 gf · cm ² / cm or more in terms of the bending stiffness value B by the KES method. Here, the bending stiffness value B according to the KES method is a problem that when the fold is actually bent to the skin surface side, the absorption surface is covered or the corner of the flap hits the skin. It is preferable that the rigidity value be obtained by bending it to the right.

  Note that the flap rigidity region in the present invention includes a second sheet when a second sheet is provided as shown in FIG. 2, and also includes an adhesive when an adhesive such as hot melt is used. It is a configuration. Such a configuration is preferable because the absolute value of the bending rigidity can be increased.

  In the present invention, the reference region for measuring the bending stiffness is the flap stiffness region 60 excluding the seal portion 50 of the front and rear flap portions. This is because when the seal portion 50 is included, the numerical value greatly changes depending on the emboss pattern. In addition, the bending rigidity of the seal portion 50 is not a problem with respect to the problem of bending at the absorber edge, and the bending rigidity in the flap rigidity region 60 is necessary.

The absolute value of the longitudinal bending stiffness is preferably at 0.15gf · ^cm 2 / ^cm or more in rigidity B bent by KES method, 0.15gf · ^cm 2 / ^cm or more 1.0gf ^· cm 2 / cm More preferably, it is 0.30 gf * cm < ² > / cm or more and 0.70 gf * cm < ² > / cm or less. It is preferable that the bending rigidity value B is less than 0.15 gf · cm ² / cm because it is not possible to prevent bending in the longitudinal direction starting from the end of the absorbent body in the process of being worn or affixed to the undergarment and pulled up. Absent. On the other hand, if it exceeds 1.0 gf · cm ² / cm, it is difficult to follow the curved shape of the body.

As an example, a surface sheet (surface sheet 20 shown in FIG. 3, basis weight 35 gms, thickness 1.6 mm), second sheet (core-sheath fiber made of PE and PET, 100% fiber having a fineness of 2.2 dtex, basis weight 20 gsm, When a 0.3 mm thick air-through nonwoven fabric is folded in two) and a back sheet (PE 100%, basis weight 23.5 gsm) are joined by hot melt (5 gsm), the longitudinal bending stiffness value B (skin surface) 0.59gf · ^cm 2 / ^cm was obtained as the bending time) to the side, 0.41gf · ^cm 2 / ^cm was obtained as the width direction of the flexural rigidity B (when bending to the skin surface).

Further, when another second sheet (basis weight 38 gsm, thickness 0.7 mm) is used in the configuration of the above example, 0.95 gf · cm ² / cm is obtained as the bending stiffness value B in the longitudinal direction, and the width A 0.75 gf · cm ² / cm was obtained as the bending stiffness value B in the direction (when bending toward the skin surface). Further, in the case of the configuration in which the second sheet is not used in the configuration of the above example, the bending stiffness value B in the longitudinal direction is obtained as 0.32 gf · cm ² / cm, and the bending stiffness value B in the width direction (to the skin surface side) Of 0.02 gf · cm ² / cm was obtained. When the surface sheet has a basis weight of 30 gms and a thickness of 1.3 mm in a configuration not using the second sheet, a bending stiffness value B in the longitudinal direction is 0.19 gf · cm ² / cm, and the width direction A bending stiffness value B (when bending toward the skin surface) was 0.01 gf · cm ² / cm.

Here, KES-FB2-AUTO-A manufactured by Kato Tech Co., Ltd. is used as a measuring device for the bending rigidity value B, and the test piece is 100 mm wide and 100 mm long (the length in the direction to be inserted into the chuck of the device). It was. The KES setting conditions were SENS: 2 × 1, mode: 1 cycle, bending curvature: 2.5 cm ⁻¹ , width 10 cm. The bending stiffness value B was set so that the bending curvature K can be measured in the range of 0.5 to 1.5 cm ⁻¹ . Since the setting condition is one cycle, it is a process of “bending −90 ° → returning to the original state → bending 90 ° to the opposite side → returning to the original state”, but the bending stiffness value B in this case is This is the value when bent by -90 ° for the first time.

In addition, as a method of measuring the thickness, using a model UF-60A of PEACOK, each member cut to a suitable size is placed on a table, and the member is sandwiched by dropping the disk from top to bottom. The thickness was measured. At this time, the load applied to each member from the disk was set to 3 g / cm ² . In addition, the thickness of the soft member or the like may gradually decrease after being sandwiched between the disks, but in this case, the value when the thickness reduction is stopped is used.

  The configuration for obtaining the bending rigidity of the present invention is not limited to the case where the top sheet 20 is used, and the thickness and basis weight of each member and the coating pattern of the adhesive can be controlled. For example, the top sheet, the second sheet, the absorber, and the back sheet used in the present invention are preferably joined to prevent the respective interlayer separation. These joints can be used with embossing, ultrasonic waves, hot-melt adhesives, etc. alone or in combination, but when joining with an adhesive by coater coating that faces continuously in the longitudinal direction It is preferable because the bending rigidity in the longitudinal direction can be increased.

It is a top view which shows one Embodiment of the absorbent article of this invention. It is a sectional perspective view of _Z 1 -Z ₁ line in FIG. It is a figure which shows an example of the manufacturing method of the surface sheet used for this invention.

Explanation of symbols

LD Longitudinal direction WD Width direction 1 Absorbent article 2 Top sheet part 3 Back sheet part 4 Absorber 5L, 5R Wing 8 Front edge 9 Back edge 20 Surface sheet 21 Side sheet 22 Second sheet 26 Groove part 27 Convex part 28 Opening part 29 Connection part 30 Back surface sheet 50 Seal part 51 Crimp part 52 Non-crimp part 55 Front flap part 56 Rear flap part 60 Flap rigidity area 100 Support member 110 1st support member 120 2nd support member

Claims (2)

A vertically long absorbent article comprising at least a part of a liquid-permeable top sheet, a back sheet having a liquid-impermeable sheet, and an absorbent body disposed between the top sheet and the back sheet. Because
Joining regions for joining the top sheet and the back sheet are formed on the outer peripheral edges at both ends in the longitudinal direction of the absorbent article,
In at least one of the flap rigid regions that reach the inner peripheral edge of the joining region that faces the both end portions from the both end portions of the absorbent body in the longitudinal direction of the absorbent article,
The surface sheet is formed of a nonwoven fabric having a plurality of groove portions and convex portions alternately formed to extend in the longitudinal direction,
The side edge region of each of the plurality of convex portions has a fiber orientation along the longitudinal direction, and the fiber density of the side edge region is higher than the average fiber density of the convex portions,
The absorbent article whose bending rigidity value in the longitudinal direction is larger than the bending rigidity value in the width direction of the absorbent article. The absorbent article according to claim 1, wherein the bending stiffness value in the longitudinal direction is 0.15 gf · cm ² / cm or more and 1.0 gf · cm ² / cm or less in terms of a bending stiffness value B by the KES method.

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