JP2024113168A - Absorbent articles - Google Patents

Abstract

To provide an absorbent article capable of improving a standing angle of a standing gathering which is directed to inside.SOLUTION: A standing gathering 60 comprises: a root part 65 which is at an outside of a width direction WD relative to a block position; and a main body part 66 which extends inward of the width direction WD without being folded from the root part 65. The main body part 66 comprises: a front end 67 and a rear end 69 which have a fixing part BP with a top sheet 30; and an intermediate part 68 which is not fixed to the top sheet 30. A gathering elastic member 63 is fitted to a tip of the intermediate part 68, and on inside ends on the front end 67 and rear end 69 in the width direction WD, free parts FP which are not fixed to the top sheet 30, are provided continuously from the intermediate part 68. Other parts of the front end 67 and rear end 69 other than the free parts FP are fixing parts BP, and a width x1 of the free part FP is 1/6 to 1/3 of a width x2 of the intermediate part 68, and a dimension y1 of the free part FP in a cross direction LD, is 1 to 9.5 times of the width x1 of the free part FP.SELECTED DRAWING: Figure 1

Description

The present invention relates to an absorbent article with improved conformability of rising gathers.

Currently, most absorbent articles such as disposable diapers and sanitary napkins have rising gathers (also called three-dimensional gathers) that rise from both sides of the width direction of the top sheet surface. By providing rising gathers, the lateral movement of excrement is blocked by the rising gathers, preventing so-called side leakage.

Many rise-up gathers have a root portion attached to the outside in the width direction of an imaginary line that continues in the front-to-rear direction through the cut-off positions on both sides of the width direction of the top sheet surface, a main body portion extending from the inside edge in the width direction of the root portion, a fixing portion in which the front and rear ends of the main body portion are fixed to the top sheet surface in a collapsed state, and an intermediate portion that is located between the front and rear fixing portions of the main body portion and is not fixed to the top sheet surface. These portions are formed from a gather sheet such as a nonwoven fabric. At least the tip portion of the rise-up gather has a two-layer structure in which the gather sheet is folded back at the tip (point), and an elongated gather elastic member is attached between the layers of at least the tip portion of the intermediate portion in a state of being stretched along the front-to-rear direction. (See, for example, Patent Documents 1 and 2.)

The middle part contracts together with the gathered elastic member due to the contraction force of the gathered elastic member, and is also capable of stretching together with the gathered elastic member. When worn, the contraction force of the gathered elastic member shortens the front-to-rear dimension of the tip of the middle part, and because the middle part is not fixed to the top sheet, the middle part rises up so that it is higher as it approaches the tip (the part farthest from the base part) and lower as it approaches the fixed parts at the front end and rear end.

In addition, in some absorbent articles such as tape-type disposable diapers, the main body of the rising gathers often extends inward in the width direction without being folded back from the base, and the tip of the main body often faces inward in the width direction.

However, this type of inward-facing gather has problems in that there is a limit to the angle at which it can rise in the crotch area (and therefore the height at which it can rise), and while the middle part that rises from the surface of the top sheet is less likely to fall outward and is excellent at preventing the leakage of soft stools, etc., it has problems in that it is difficult for it to move outward in response to leg movements when in a lateral position, etc., and the tip is prone to coming into contact with the skin.

JP 2019-130278 A JP 2018-140068 A

Therefore, the main objective of this invention is to improve the rising angle of the inward rising gathers.

The absorbent article that solves the above problems is as follows.
<First aspect>
An absorber;
A liquid-permeable top sheet disposed on the front side of the absorbent body;
and rising gathers provided on both sides of the surface of the top sheet in the width direction,
The rising gathers have a root portion attached to the outside in the width direction of an imaginary line that passes through a blocking position on both sides in the width direction of the surface of the top sheet and continues in the front-rear direction, and a main body portion that extends inward in the width direction from an inner edge in the width direction of the root portion without being folded back,
The main body portion has a front end portion and a rear end portion having a fixing portion fixed to the top sheet, and an intermediate portion located between the front end portion and the rear end portion and not fixed to the top sheet,
A gather elastic member having an elongated shape along the front-rear direction is attached to at least the tip of the intermediate portion,
the intermediate portion is contracted together with the gathered elastic member by a contractile force of the gathered elastic member and is stretchable together with the gathered elastic member;
A free portion that is not fixed to the top sheet is provided at an inner end in the width direction of at least one of the front end portion and the rear end portion so as to continue from the intermediate portion, and the front end portion and the rear end portion other than the free portion are fixed portions,
The width of the free portion is 1/6 to 1/3 of the width of the intermediate portion, and the dimension of the free portion in the front-to-rear direction is 1 to 9.5 times the width of the free portion.
An absorbent article characterized by:

(Action and Effect)
In conventional inward rising gathers, the front and rear fixing parts of the main body part are provided over almost the entire width of the main body part. In this case, when worn, the front and rear fixing parts suppress the rising of the middle part over the entire width, so the rising angle of the middle part is reliably limited and the tip of the middle part is also suppressed from falling outward. In addition, the middle part is less likely to move outward in response to leg movements, and the tip of the middle part is more likely to come into tight contact with the skin.
In contrast, in the present absorbent article, a free portion (a portion not fixed to the top sheet) having a certain width is provided at the inner end in the width direction of at least one of the front end and rear end of the main body portion so as to continue from the middle portion. Therefore, although the front and rear fixed portions suppress the rise of the middle portion when worn, the degree of suppression is mitigated by the rise of the free portion (which rises to continue from the middle portion, but does not rise as much as the middle portion because the width of the free portion is short), so the rise angle of the middle portion is definitely larger than when there is no free portion. In addition, the presence of the free portion makes it easier for the tip of the middle portion to fall outward, and the middle portion is more likely to move outward following the movement of the legs. As a result, the tip of the middle portion is less likely to come into tight contact with the skin.

<Second aspect>
The width of the free portion is 3.5 mm or more,
the intermediate portion has the gathered elastic member in a tip side region having a width equal to the width of the free portion, and does not have the gathered elastic member in any other region than the tip side region;
The absorbent article of the first aspect.

(Action and Effect)
The width of the free portion can be determined as appropriate, but is preferably 3.5 mm or more. In addition, the intermediate portion preferably has the gathered elastic member only in the tip side region having a width equal to the width of the free portion, so that the portion having the gathered elastic member is less likely to come into tight contact with the skin.
The gathered elastic member may extend to the free portion, in which case it may be fixed, or may be unfixed and not exert a contractile force.

<Third aspect>
Among the regions overlapping the back side of the intermediate portion in an expanded state, a base portion side region having a width equal to the width of the fixing portion has an elongated inside elastic member extending along the front-rear direction on the back side of the top sheet,
The base portion side region is contracted together with the inside elastic member due to a contractile force of the inside elastic member, and is also stretchable together with the inside elastic member.
The absorbent article according to the first or second aspect.

(Action and Effect)
By providing the inside elastic member at the position of this embodiment, the portion having the inside elastic member is raised, and the portion that becomes the base of the rising gathers is inclined so that the rising angle of the middle portion becomes large, which is preferable.

<Fourth aspect>
The absorbent body has a narrowed portion in the middle in the front-rear direction, the narrowed portion being narrower than both front and rear ends of the absorbent body,
The inside elastic member is disposed so as to pass through the constricted portion.
The absorbent article of the third aspect.

(Action and Effect)
Since the constricted portion does not have an absorbent body, it has a lower rigidity than the portion having an absorbent body and is easily deformed. Therefore, it is preferable to provide an inside elastic member so that it passes through this position, because this makes it easier for the portion that becomes the base of the rising gathers to incline.

<Fifth aspect>
Both the front end and the rear end have the free portion;
The width of the free portion of the front end portion is wider than the width of the free portion of the rear end portion.
The absorbent article according to any one of the first to fourth aspects.

(Action and Effect)
Since the range of motion of the legs is greater at the front than at the rear, making the width of the free portion at the front end of the main body wider than the width of the free portion at the rear end, as in this embodiment, is one preferred embodiment.

<Sixth aspect>
Disposable diapers for low birth weight babies
The absorbent article according to any one of the first to fifth aspects.

(Action and Effect)
In disposable diapers for low birth weight infants, a weaker but softer fit is more preferable than a firm fit, and therefore the above-mentioned rising gathers having a free portion are suitable for disposable diapers for low birth weight infants.

The present invention offers the advantage of being able to suppress seepage of excretory fluids at the base of the rising gathers.

FIG. 2 is a plan view showing the inner surface of the connected disposable diaper in an unfolded state. FIG. 2 is a plan view showing the outer surface of the connected disposable diaper in an unfolded state. This is a cross-sectional view taken along line 6-6 in Figure 1. This is a cross-sectional view taken along line 7-7 in Figure 1. This is a cross-sectional view taken along line 8-8 in Figure 1. This is a cross-sectional view taken along line 5-5 in Figure 1. FIG. 2 is an enlarged cross-sectional view showing a main part of the rising gathers. FIG. 2 is an enlarged cross-sectional view showing a main part of the rising gathers. FIG. 2 is a perspective view showing an outline of the inner surface in an attached state. FIG. 2 is a plan view showing the inner surface of the connected disposable diaper in an unfolded state. FIG. 2 is a plan view showing the inner surface of the connected disposable diaper in an unfolded state.

1 to 6 show a connected disposable diaper (also generally called a tape-type disposable diaper), which is an example of an absorbent article. In the figures, the symbol X indicates the overall width of the diaper excluding the connecting tape 13, and the symbol L indicates the overall length of the diaper. In addition, the dotted pattern and the * mark in the cross-sectional view indicate hot melt adhesive as a joining means for joining each component member located on the front side and back side, unless otherwise specified. The hot melt adhesive can be applied by known methods such as slot application, continuous line or dotted line bead application, spiral, Z-shaped, wavy, etc. spray application, or pattern coating (transfer of hot melt adhesive using a letterpress method). Alternatively or in addition to this, in the fixing portion of the elastic member, the hot melt adhesive can be applied to the outer peripheral surface of the elastic member to fix the elastic member to the adjacent member. As the hot melt adhesive, for example, EVA-based, adhesive rubber-based (elastomer-based), olefin-based, polyester/polyamide-based, and other types are available, but there are no particular limitations on the types that can be used. As a fixing or joining means for joining each component, material welding means such as heat sealing or ultrasonic sealing can be used. In a portion where liquid permeability in the thickness direction is required, adjacent components in the thickness direction are fixed or joined in an intermittent pattern. For example, when such intermittent fixing or joining is performed with a hot melt adhesive, intermittent pattern application such as a spiral, Z-shape, or wave shape can be suitably used, and when applying to an area greater than the application width of one nozzle, intermittent pattern application such as a spiral, Z-shape, or wave shape can be performed with or without gaps in the width direction.

This connected disposable diaper has a crotch area M including the center in the front-to-rear direction LD, a ventral area F extending forward from the center in the front-to-rear direction LD, and a dorsal area B extending rearward from the center in the front-to-rear direction LD. This connected disposable diaper also has an absorbent body 56 built into an area including the crotch area M, a liquid-permeable top sheet 30 covering the front side of the absorbent body 56, a liquid-impermeable sheet 11 covering the back side of the absorbent body 56, and an exterior nonwoven fabric 12 covering the back side of the liquid-impermeable sheet 11 and constituting the outer surface of the product. When the absorbent body 56 has a constricted area 56n described below, the crotch area M refers to the area in the front-to-rear direction LD that has the constricted area 56n. When the absorbent body 56 does not have a constricted area 56n, the crotch area M refers to the area located in the center in the front-to-rear direction LD and whose dimension in the front-to-rear direction LD is 30 to 60% of the overall length of the product.

The material and characteristic parts of each part will be described in order below. In the following description, the nonwoven fabric may be any known nonwoven fabric depending on the part and purpose. The fibers constituting the nonwoven fabric may be selected without particular limitation from synthetic fibers such as olefins, polyesters, polyamides, etc. (including single-component fibers and composite fibers such as core-sheath fibers), such as polyethylene or polypropylene, regenerated fibers such as rayon or cupra, natural fibers such as cotton, etc., and may be used in combination. In order to increase the flexibility of the nonwoven fabric, it is preferable to use crimped fibers as the constituent fibers. The fibers constituting the nonwoven fabric may be hydrophilic fibers (including fibers that have been rendered hydrophilic by a hydrophilizing agent), hydrophobic fibers, or water-repellent fibers (including fibers that have been rendered water-repellent by a water-repellent agent). Furthermore, nonwoven fabrics are generally classified into staple fiber nonwoven fabrics, long fiber nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlace nonwoven fabrics, thermal bond (air-through) nonwoven fabrics, needle punched nonwoven fabrics, point bond nonwoven fabrics, laminated nonwoven fabrics (including SMS nonwoven fabrics and SMMS nonwoven fabrics in which a meltblown layer is sandwiched between spunbond layers), etc., depending on the fiber length, sheet formation method, fiber bonding method, and laminated structure, and any of these nonwoven fabrics can be used.
(Absorbent)
The absorbent 56 is a part that absorbs and retains excreted liquid, and can be formed by a fiber assembly. As the fiber assembly, in addition to stacked staple fibers such as cotton-like pulp and synthetic fibers, a filament assembly obtained by opening a tow (fiber bundle) of synthetic fibers such as cellulose acetate as necessary can be used. The fiber basis weight can be, for example, about 100 to 300 g/m ² when stacking cotton-like pulp or staple fibers, and can be, for example, about 30 to 120 g/m ² when the filament assembly is used. The fineness of the synthetic fibers is, for example, 1 to 16 dtex, preferably 1 to 10 dtex, and more preferably 1 to 5 dtex. In the case of a filament assembly, the filaments may be non-crimped fibers, but are preferably crimped fibers. The degree of crimp of the crimped fiber can be, for example, about 5 to 75 pieces per 2.54 cm, preferably about 10 to 50 pieces, and more preferably about 15 to 50 pieces. Furthermore, uniformly crimped fibers can be used.

The shape of the absorbent body 56 can be determined as appropriate. For example, the absorbent body 56 can be formed in a roughly hourglass shape with a narrower constricted portion 56n at the portion located in the crotch area M than the front and rear sides as shown in the example, or it can be formed in any other appropriate shape, such as a rectangular shape. In general, it is preferable to provide the absorbent body 56 from the front to the rear of the crotch area, but this is not a limitation.

(Superabsorbent polymer particles)
The absorbent body 56 may contain superabsorbent polymer particles in part or in whole. The superabsorbent polymer particles include not only "particles" but also "powder". The superabsorbent polymer particles may be those used in this type of absorbent article as they are. The particle size of the superabsorbent polymer particles is not particularly limited, but it is preferable that, for example, when the particles are sieved (shaken for 5 minutes) using a 500 μm standard sieve (JIS Z8801-1:2006) and the particles that fall below the sieve are sieved (shaken for 5 minutes) using a 180 μm standard sieve (JIS Z8801-1:2006), the proportion of particles remaining on the 500 μm standard sieve is 30% by weight or less and the proportion of particles remaining on the 180 μm standard sieve is 60% by weight or more.

There are no particular limitations on the material that can be used for the superabsorbent polymer particles, but those with a water absorption capacity of 40 g/g or more are preferred. Superabsorbent polymer particles include starch-based, cellulose-based and synthetic polymer-based materials, and examples of materials that can be used include starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, crosslinked products of sodium carboxymethylcellulose and acrylic acid (salt) polymers. The shape of the superabsorbent polymer particles is preferably the commonly used powder-like form, but other shapes can also be used.

The highly absorbent polymer particles preferably have a water absorption speed of 70 seconds or less, and particularly 40 seconds or less. If the water absorption speed is too slow, the liquid supplied to the absorbent body 56 tends to flow back out of the absorbent body 56, which is known as backflow.

The highly absorbent polymer particles preferably have a gel strength of 1000 Pa or more. This effectively prevents the sticky feeling after absorbing liquid, even when the absorbent body 56 is bulky.

The basis weight of the highly absorbent polymer particles can be appropriately determined depending on the absorption amount required for the application of the absorbent body 56. Therefore, although it cannot be generally stated, it can usually be set to 50 to 350 g/ ^m2 .

(packaging sheet)
In order to prevent the superabsorbent polymer particles from escaping or to improve the shape retention of the absorbent body 56, the absorbent body 56 can be incorporated as an absorbent element 50 wrapped in a wrapping sheet 58. As the wrapping sheet 58, tissue paper, particularly crepe paper, nonwoven fabric, polylaminated nonwoven fabric, a sheet with small holes, etc. can be used. However, it is preferable that the sheet is one from which the superabsorbent polymer particles do not escape. When using nonwoven fabric instead of crepe paper, hydrophilic SMMS (spunbond/meltblown/meltblown/spunbond) nonwoven fabric is particularly suitable, and polypropylene, polyethylene/polypropylene, etc. can be used as the material. The fiber basis weight is preferably 5 to 40 g/m ² , particularly 10 to 30 g/m ² .

As shown in FIG. 3, the packaging sheet 58 may be structured so that one sheet wraps the entire absorbent body 56, or multiple sheets, such as two sheets on top and two sheets on the top and bottom, may wrap the entire absorbent body 56. The packaging sheet 58 may also be omitted.

(Top sheet)
The top sheet 30 is liquid permeable, and may be, for example, a perforated or non-perforated nonwoven fabric, a perforated plastic sheet, or the like.

The top sheet 30 extends from the front end to the rear end of the product in the front-to-rear direction, but can be modified as needed. The top sheet 30 in the illustrated example extends beyond the boundary between the main body portion 66 and the root portion 65 of the rising gathers 60 described below in the width direction WD, but is not limited to this. The top sheet 30 in the illustrated example extends laterally beyond the side edges of the absorbent body 56, but can be modified as needed, such as by positioning the side edges of the top sheet 30 inward beyond the side edges of the absorbent body 56.

(middle seat)
Although not shown, an intermediate sheet (also called a "second sheet") can be provided adjacent to the back side of the top sheet 30 in order to prevent liquid that has permeated the top sheet 30 from flowing back.

As the intermediate sheet, various nonwoven fabrics can be suitably used, and particularly, bulky air-through nonwoven fabrics can be suitably used. For the air-through nonwoven fabric, composite fibers with a core-sheath structure are preferably used, and in this case, the resin used for the core may be polypropylene (PP), but polyester (PET) with high rigidity is preferred. The basis weight is preferably 17 to 80 g/ ^m2 , more preferably 25 to 60 g/ ^m2 . The thickness of the raw fiber of the nonwoven fabric is preferably 2.0 to 10 dtex. In order to make the nonwoven fabric bulky, it is also preferable to use eccentric fibers with no core in the center, hollow fibers, or eccentric and hollow fibers as the mixed fibers of all or part of the raw fiber.

The intermediate sheet may be shorter than the width of the absorbent body 56 and disposed in the center, or may be disposed so as to cover the entire width of the absorbent body 56. The intermediate sheet may be disposed over the entire length of the diaper, or may be disposed only in the middle portion including the excretion position.

(Liquid-impermeable sheet)
The liquid-impermeable sheet 11 is not particularly limited, but is preferably moisture-permeable. For example, a microporous sheet obtained by kneading an inorganic filler into an olefin resin such as polyethylene or polypropylene to form a sheet and then stretching the sheet in a uniaxial or biaxial direction can be suitably used as the liquid-impermeable sheet 11. In addition, a sheet having improved waterproofness using a nonwoven fabric as a base material can also be used as the liquid-impermeable sheet 11.

It is preferable that the liquid-impermeable sheet 11 has an extension portion that extends outward in the width direction WD beyond the top sheet 30. It is desirable that the liquid-impermeable sheet 11 extends over the same or a wider range than the absorbent body 56 in the front-rear direction LD and the width direction WD.

(Outer nonwoven fabric)
The exterior nonwoven fabric 12 covers the entire back side of the liquid-impermeable sheet 11, giving the outer surface of the product a cloth-like appearance. The nonwoven fabric may be used in a single layer or in a stack of multiple layers. In the latter case, it is preferable to bond the nonwoven fabrics together with a hot melt adhesive or the like. When using a nonwoven fabric, it is preferable that the fineness of the constituent fibers is 1.0 to 6.0 dtex, the basis weight is 15 to 45 g/m ² , and the thickness is 0.5 to 3.0 mm.

A sheet other than nonwoven fabric can be used instead of the exterior nonwoven fabric 12, and the exterior nonwoven fabric 12 can be omitted.

(End flap section, side flap section)
The connected disposable diaper in the illustrated example has a pair of end flap portions EF that do not have the absorbent body 56 and extend to the front and rear sides of the absorbent body 56, respectively, and a pair of side flap portions SF that do not have the absorbent body 56 and extend laterally beyond both side edges of the absorbent body 56. The side flap portions SF may be made of a material (such as the exterior nonwoven fabric 12) that is continuous with the portion having the absorbent body 56, as in the illustrated example, or may be formed by attaching another material.

(Wing part)
In this connected disposable diaper, the back portion B has wing portions WP extending outward in the width direction WD beyond the crotch portion M. Similarly, the ventral portion F also has wing portions WP extending outward in the width direction WD beyond the crotch portion M. These wing portions WP may be formed from a separate member from the other portions. However, in the structure having side flap portions SF as shown in the figure, it is preferable to form narrowed side edges 70 from the side edges of the crotch portion M to the lower edges 71 of the wing portions WP by cutting out the middle of the sides of the side flap portions SF in the front-to-rear direction LD, as this facilitates manufacturing.

(Connecting tape)
1, 2 and 6, the wing portions WP of the back portion B are provided with connecting tapes 13 which are detachably connected to the outer surface of the abdominal portion F. When putting on the diaper 10, the connecting tapes 13 are wrapped around the outer surface of the abdominal portion F from both sides of the waist, and the connecting portions 13A of the connecting tapes 13 are connected to appropriate locations on the outer surface of the abdominal portion F.

As shown in FIG. 6, the connecting tape 13 has a base end 13C fixed to the wing portion WP, a sheet base material forming a main portion 13B extending from the base end 13C, and a connecting portion 13A for the abdominal portion F provided in the middle of the main portion 13B in the width direction WD of the sheet base material. The base end 13C side of the main portion 13B from the connecting portion 13A is a non-connecting portion that is not connected to the abdominal portion F. The side edge of the base end 13C may coincide with the side edge of the wing portion WP, or may be slightly spaced inward in the width direction WD from the side edge of the wing portion WP as shown in the example. The inner edge of the connecting portion 13A in the width direction may coincide with the side edge of the wing portion WP, but it is preferable that it is sufficiently spaced outward in the width direction WD from the side edge of the wing portion WP as shown in FIG. 6.

The connecting portion 13A may be provided with a hook material (male material) of a mechanical fastener (hook-and-loop fastener) or with an adhesive layer. The hook material has a number of engaging protrusions on its connecting surface, and the shapes of the engaging protrusions include (A) a L-shape, (B) a J-shape, (C) a mushroom shape, (D) a T-shape, and (E) a double J-shape (a shape in which two J-shapes are joined back-to-back), but any shape is acceptable.

As the sheet base material forming the base end portion 13C to the main body portion 13B, a nonwoven fabric, a plastic film, a polylaminated nonwoven fabric, paper, or a composite material thereof can be used, but a spunbond nonwoven fabric, an air-through nonwoven fabric, or a spunlace nonwoven fabric having a fineness of 1.0 to 3.5 dtex, a basis weight of 60 to 100 g/ ^m2 , and a thickness of 1 mm or less is preferred.

The connecting tape 13 may be one in which at least a portion of the non-connecting portion stretches in the width direction WD, or one in which the entire tape does not stretch.

(Target section)
A target portion 12T is provided at a connection point of the connecting tape 13 in the abdominal portion F. As shown in the illustrated example, the target portion 12T can be provided by attaching a sheet material for facilitating connection to the outer surface of the abdominal portion F.

The sheet material for forming the target portion 12T is not particularly limited, but if the connecting portion 13A is a hook material, for example, a long-fiber nonwoven fabric in which the fibers are partially welded together by ultrasonic welding in an intermittent pattern can be used.

In addition, when the connecting portion 13A is a hook material, a composite sheet material in which a large number of loop threads are sewn onto the surface of a base material made of a plastic film or nonwoven fabric, into which the engaging protrusions of the hook material can be entangled, can be used as the sheet material for forming the target portion 12T.

Furthermore, when the connecting portion 13A is a hook material and the connecting portion of the connecting tape 13 in the abdominal portion F is made of nonwoven fabric (for example, when an exterior nonwoven fabric 12 is provided as in the illustrated example), it is also possible to use an appropriate location of the exterior nonwoven fabric 12 as the target portion 12T and connect the hook material by entangling it with the fibers of the exterior nonwoven fabric 12 without adding a sheet material to form the target portion 12T.

On the other hand, if the connecting portion 13A is an adhesive layer, the sheet material for forming the target portion 12T can be a sheet material made of a smooth, adhesive plastic film with a release treatment applied to the surface.

(Rise and gather)
In order to block excrement moving laterally along the top sheet 30 and prevent so-called lateral leakage, rising gathers 60 are provided on both sides of the surface of the top sheet 30 in the width direction WD.

The rising gathers 60 have a root portion 65 attached to the outside of the width direction WD of a virtual line 60B that passes through the cutoff positions on both sides of the width direction WD of the surface of the top sheet 30 and continues in the front-to-back direction LD, and a main body portion 66 that extends from the inner edge of the root portion 65 in the width direction WD to the inside of the width direction WD without being folded back. The main body portion 66 also has a front end portion 67 and a rear end portion 69 that have a fixed portion BP fixed to the top sheet 30 (in other words, the range of the main body portion 66 in the front-to-back direction LD that has the fixed portion BP is the front end portion 67 and the rear end portion 69), and an intermediate portion 68 that is located between the front end portion 67 and the rear end portion 69 and is not fixed to the top sheet 30, and an elongated gather elastic member 63 that is aligned along the front-to-back direction LD is attached to at least the tip of the intermediate portion 68.

The main body 66 and the root 65 can be formed by a gathered sheet 62 that is folded in half at the tip of the main body 66 (the end opposite to the root 65) to form a two-layer structure of an inner layer 62n and an outer layer 62f. In this case, a gathered elastic member 63 can be provided between the inner layer 62n and the outer layer 62f. The inner layer 62n may extend to the root 65 as shown in FIG. 3, or may extend only to the middle position in the width direction WD of the main body 66 (not shown). In other words, the main body 66 may have a single layer on the root 65 side. The gathered sheet 62 may have a layer structure of three or more layers, and may have a liquid-impermeable film as an intermediate layer. When the gathered sheet 62 has a multi-layer structure, the number of layers may be increased by attaching another nonwoven fabric without folding one nonwoven fabric, or by folding one nonwoven fabric and increasing the number of layers.

The root portion 65 has a joining start point in the width direction WD on the side of the top sheet 30, and this joining start point passes through the blocking position and continues in the front-to-rear direction LD. In addition, the root portion 65 in the illustrated example has an extension portion that extends outward in the width direction WD beyond the top sheet 30, and this extension portion is joined by a hot melt adhesive or the like to the inner surface of each side flap portion SF, that is, in the illustrated example, to the side of the liquid-impermeable sheet 11 and the side of the exterior nonwoven fabric 12 located outside of the liquid-impermeable sheet 11 in the width direction WD.

Although the main body portion 66 has fixed parts BP fixed to the surface of the top sheet 30 at both ends in the front-rear direction LD, the intermediate portion 68 located between the front and rear fixed parts BP is not fixed to the surface of the top sheet 30. The intermediate portion 68 contracts together with the gathered elastic member 63 due to the contractile force of the gathered elastic member 63, and is also capable of stretching together with the gathered elastic member 63. As a result, when worn, the dimension of the tip of the intermediate portion 68 in the front-rear direction LD is shortened by the contractile force of the gathered elastic member 63, and since the intermediate portion 68 is not fixed to the top sheet 30, as shown in Figures 7 and 9, the intermediate portion 68 rises up so that it is higher as it approaches the tip (the part farthest from the root portion 65) and lower as it approaches the fixed parts BP of the front end portion 67 and the rear end portion 69.

The type of gathered sheet 62 is not particularly limited, but in most cases, a water-repellent nonwoven fabric is used from the viewpoints of touch and liquid blocking properties. In particular, nonwoven fabrics having a meltblown layer between spunbond layers (SMS nonwoven fabric, SMMS nonwoven fabric, SSMS nonwoven fabric, SSMMS nonwoven fabric) are suitable because they can achieve both touch and liquid blocking properties. The nonwoven fabric can be used in a single layer or multiple layers stacked together. In the latter case, it is preferable to bond the nonwoven fabrics together with a hot melt adhesive or the like.

As the gathered elastic member 63, an elastic member such as rubber in the shape of a thread, string, strip, or other elongated shape can be used. As in the illustrated example, only one gathered elastic member 63 can be provided on each side, or multiple gathered elastic members can be provided on each side. The elongation rate of the gathered elastic member 63 in the deployed state can be determined as appropriate, but is preferably about 150 to 250%, and more preferably 180 to 230%. When synthetic rubber thread such as spandex is used as the gathered elastic member 63, its thickness is preferably 300 to 700 dtex, and more preferably 400 to 500 dtex.

Characteristically, a free portion FP that is not fixed to the top sheet 30 is provided at the inner end in the width direction WD of the front end 67 and the rear end 69 of the main body portion 66 so as to continue from the intermediate portion 68, and the main body portion 66 other than the free portion FP is a fixed portion BP. The width x1 of the free portion FP is 1/6 to 1/3 of the width x2 of the intermediate portion 68, and the dimension of the free portion FP in the front-to-back direction LD is 1 to 9.5 times the width x1 of the free portion FP. Note that the width x1 of the free portion FP is constant in the illustrated example, but may vary depending on the position in the front-to-back direction LD, in which case it means the minimum value. The width x2 of the intermediate portion 68 is constant in the illustrated example, but may vary depending on the position in the front-to-back direction LD, in which case it means the maximum value.

In this type of inward rising gather 60, as shown in Figures 7 and 9, the front and rear fixed parts BP suppress the rising of the middle part 68 when worn, but the degree of suppression is mitigated by the rising of the free part FP (which rises to follow the middle part 68, but does not rise as much as the middle part 68 because the width x1 of the free part FP is short), so the rising angle of the middle part 68 is definitely greater than if there was no free part FP. Also, due to the presence of the free part FP, as shown in Figure 8, the tip of the middle part 68 is more likely to fall outward, and the middle part 68 is more likely to move outward in response to the movement of the legs. As a result, the tip of the middle part 68 is less likely to come into tight contact with the skin.

The dimensions of the free portion FP can be appropriately determined within the above range. It is particularly preferable that the width x1 of the free portion FP is 2/11 to 1/4 of the width x2 of the intermediate portion 68. More specifically, it is preferable that the lower limit of the width x1 of the free portion FP is 3.5 mm. In addition, when both the front end 67 and the rear end 69 have free portions FP, the width x1 of the free portion FP of the front end 67 and the width x1 of the free portion FP of the rear end 69 may be equal, but since the range of motion of the leg is greater on the front side than on the rear side, one preferred embodiment is to make the width x1 of the free portion FP of the front end 67 of the main body 66 wider than the width x1 of the free portion FP of the rear end 69 (for example, 1.2 to 1.5 times) as shown in FIG. 10.

It is more preferable that the dimension y1 of the free portion FP in the front-rear direction LD is 2 to 8.5 times the width x1 of the free portion FP. When the free portion FP is provided at the front end 67 of the main body portion 66, as in the example shown in FIG. 1, it is preferable that the free portion FP is provided over the entire length of the front end 67, and when the free portion FP is provided at the rear end 69 of the main body portion 66, it is preferable that the free portion FP is provided over the entire length of the rear end 69. However, when the free portion FP is provided at the front end 67, as shown in FIG. 11, the free portion FP can be provided only on the rear side of the front end 67, and the entire front side of the front end 67 can be the fixed portion BP over the entire width direction WD. Similarly, when the free portion FP is provided at the rear end 69, as shown in FIG. 11, the free portion FP can be provided only on the front side of the rear end 69, and the entire rear side of the rear end 69 can be the fixed portion BP over the entire width direction WD. As can be seen from this, when the free portion FP is provided at both the front end 67 and the rear end 69 of the main body portion 66, the dimension in the front-to-rear direction LD of the free portion FP at the front end 67 and the dimension in the front-to-rear direction LD of the free portion FP at the rear end 69 may be equal to or different from each other. As shown in the illustrated example, it is preferable to provide the free portion FP at both the front end 67 and the rear end 69 of the main body portion 66, but it is also possible to provide it only at the front end 67 or only at the rear end 69.

Unlike the illustrated example, the gathered elastic member 63 may be provided in a portion other than the tip of the intermediate portion 68, but it is preferable to provide it only in a tip-side region of a width equal to the width x1 of the free portion FP as in the illustrated example, and not to have the gathered elastic member 63 in any portion other than the tip-side region, since this prevents the portion having the gathered elastic member 63 from coming into tight contact with the skin.

The gathered elastic member 63 may extend to the free part FP, or may not extend to the free part FP. In the former case, the part of the gathered elastic member 63 located at the free part FP may be fixed to the free part FP, and the contraction force of the gathered elastic member 63 may act on the free part FP, or the part of the gathered elastic member 63 located at the free part FP may not be fixed to the free part FP, and the contraction force of the gathered elastic member 63 may not act on the free part FP.

(Inside flat gathers)
As shown in the illustrated example, it is preferable that, among the regions overlapping the back side of the intermediate portion 68 in the unfolded state, an elongated inside elastic member 61 is provided along the front-to-rear direction LD on the back side of the top sheet 30 in the root portion side region equal to the width x3 of the fixed portion BP, and the root portion side region is contracted together with the inside elastic member 61 by the contractile force of the inside elastic member 61 and is also stretchable together with the inside elastic member 61 (so-called planar gathers). By providing such an inside elastic member 61, the portion having the inside elastic member 61 is raised in the direction shown by the white arrow in Figures 7 and 8, and the portion serving as the base of the rising gathers 60 can be inclined so that the rising angle of the intermediate portion 68 becomes larger (this state is not shown in Figures 7 and 8). The inside elastic member 61 can also be omitted.

The position of the inside elastic member 61 can be appropriately determined within the above-mentioned range. As an example, the position of the inside elastic member 61 in the width direction WD is preferably within 10 mm, particularly 7.5 mm, in the width direction WD from the cutoff position (the boundary between the root portion 65 and the middle portion 68). In addition, when the position of the front end of the product in the front-rear direction LD is 0% and the position of the rear end of the product is 100%, it is preferable that the front end of the part stretched by the inside elastic member 61 is located in a range of 20 to 30%, and the rear end of the part stretched by the inside elastic member 61 is located in a range of 20 to 30%. As shown in the illustrated example, when a narrowed portion 56n is formed in the middle of the absorbent 56 in the front-rear direction LD (particularly in the range of the front-rear direction LD including the crotch portion M) that is narrower than both the front and rear sides, it is preferable that the inside elastic member 61 is arranged to pass through the narrowed portion 56n. Since the narrowed portion 56n is a portion that does not have the absorbent 56, it has lower rigidity and is more easily deformed than the portion that has the absorbent 56. Therefore, if the inside elastic member 61 is provided so that it passes through this position, the part that forms the base of the rising gathers 60 will be more likely to be inclined.

The inside elastic member 61 can be provided between the packaging sheet 58 and the liquid-impermeable sheet 11, or between the liquid-impermeable sheet 11 and the exterior nonwoven fabric 12. The inside elastic member 61 can be provided with only one on each side as in the illustrated example, or multiple on each side spaced apart in the width direction.

The inside elastic member 61 can be an elastic member such as rubber in the form of a long and thin thread, string, strip, etc. The inside elastic member 61 can be provided with only one on each side as in the illustrated example, or multiple on each side. The elongation rate of the inside elastic member 61 in the deployed state can be determined as appropriate, but is preferably about 160 to 240%, and more preferably 180 to 220%. When using synthetic rubber thread such as spandex as the inside elastic member 61, its thickness is preferably 400 to 700 dtex, and more preferably 500 to 650 dtex.

The contraction force acting portion of the inside elastic member 61 (the portion in which the inside elastic member 61 is shown in the figure) may be the same as or shorter than the portion where the inside elastic member 61 exists. In other words, the inside elastic member 61 exists in front of, behind, or on both sides of the contraction force acting portion of the inside elastic member 61, but the contraction force does not act on the inside elastic member 61 except in the contraction force acting portion because the inside elastic member 61 is not fixed to the sheet sandwiching the inside elastic member 61, the inside elastic member 61 is cut into small pieces at one or multiple locations, or both (effectively equivalent to no elastic member being provided), and the contraction force acting portion may be shorter than the portion where the inside elastic member exists.

(Outside flat gathers)
An outside elastic member 64 is provided on the outside of the blocking position in the width direction WD of each side flap portion SF, and the leg surrounding portion of each side flap portion SF is contracted together with the outside elastic member 64 by the contractile force of the outside elastic member 64 and is also stretchable together with the outside elastic member 64 (so-called flat gathers may be formed). The outside elastic member 64 may be omitted.

The outside elastic member 64 can be provided between the gathered sheet 62 and the liquid-impermeable sheet 11 as in the illustrated example, or between the liquid-impermeable sheet 11 and the exterior nonwoven fabric 12 in the side flap portion SF. The outside elastic member 64 can be provided with only one on each side as in the illustrated example, or multiple on each side spaced apart in the width direction.

The outside elastic member 64 may be an elastic member such as rubber in the form of a long and thin thread, string, strip, etc. The outside elastic member 64 may be provided one on each side as in the illustrated example, or multiple on each side. The stretch rate of the outside elastic member 64 in the deployed state may be determined as appropriate, but is preferably about 170-250%, and more preferably 190-230%. When using synthetic rubber thread such as spandex as the outside elastic member 64, its thickness is preferably 400-700 dtex, and more preferably 500-650 dtex.

The contraction force acting portion of the outside elastic member 64 (the portion in the figure where the outside elastic member 64 is shown) may be the same as or shorter than the portion where the outside elastic member 64 exists. In other words, the outside elastic member 64 exists in front of, behind, or on both sides of the contraction force acting portion of the outside elastic member 64, but the contraction force does not act on the outside elastic member 64 except in the contraction force acting portion because it is not fixed to the sheet sandwiching the outside elastic member 64, the outside elastic member 64 is cut into small pieces at one or multiple locations, or both (effectively equivalent to no elastic member being provided), and the contraction force acting portion may be shorter than the portion where the outside elastic member 64 exists.

<Explanation of terms used in the specification>
When used in this specification, the following terms have the following meanings, unless otherwise stated in the specification.

"MD direction" and "CD direction" refer to the flow direction (MD direction) in the manufacturing equipment and the horizontal direction (CD direction) perpendicular to it, one of which is the front-to-back direction of the product, and the other is the width direction of the product. The MD direction of a nonwoven fabric is the direction of fiber orientation of the nonwoven fabric. Fiber orientation is the direction in which the fibers of the nonwoven fabric are aligned, and can be determined, for example, by a measurement method based on the fiber orientation test method using zero-distance tensile strength in TAPPI standard method T481, or a simplified measurement method that determines the fiber orientation direction from the tensile strength ratio in the front-to-back direction and the width direction.

The "front-rear direction" refers to the direction indicated by the symbol LD in the figure (longitudinal direction), and the "width direction" refers to the direction indicated by the symbol WD in the figure (left-right direction), with the front-rear direction and the width direction being perpendicular to each other.

- "Front side" means the side closest to the wearer's skin when worn, and "back side" means the side farthest from the wearer's skin when worn.

- "Front side" means the side of the component that is closest to the wearer's skin when worn, and "back side" means the side that is away from the wearer's skin when worn.

"Expanded state" means a flat, unfolded state without contraction (including any contraction, such as contraction due to elastic members) or sagging.

"Elongation rate" refers to the value when the natural length is 100%. For example, an elongation rate of 200% is equivalent to an elongation ratio of 2 times.

"Artificial urine" is a mixture of 2 wt% urea, 0.8 wt% sodium chloride, 0.03 wt% calcium chloride dihydrate, 0.08 wt% magnesium sulfate heptahydrate, and 97.09 wt% ion-exchanged water, and is used at a temperature of 37 degrees unless otherwise specified.

"Gel strength" is measured as follows. 1.0 g of superabsorbent polymer is added to 49.0 g of artificial urine and stirred with a stirrer. The resulting gel is left in a thermo-hygrostat at 40°C x 60% RH for 3 hours, then returned to room temperature and the gel strength is measured with a curd meter (I.techno Engineering: Curdmeter-MAX ME-500).

"Basis weight" is measured as follows. After pre-drying the sample or test piece, leave it in a test room or device under standard conditions (test location: temperature 23±1°C, relative humidity 50±2%) until it reaches a constant weight. Pre-drying refers to bringing the sample or test piece to a constant weight in an environment at a temperature of 100°C. Note that pre-drying is not necessary for fibers with an official moisture regain of 0.0%. Using a sample collection template (100mm x 100mm), cut out a sample measuring 100mm x 100mm from the test piece that has reached a constant weight. Measure the weight of the sample and multiply it by 100 to calculate the weight per square meter, which is the basis weight.

The "thickness" is automatically measured using an automatic thickness measuring device (KES-G5 handy compression tester) under the conditions of a load of 0.098 N/cm ² and a pressurized area of 2 cm ² .

"Water absorption" is measured according to JIS K7223-1996 "Test method for water absorption of superabsorbent resins."

"Water absorption rate" refers to the "time to the end point" when 2 g of superabsorbent polymer and 50 g of saline are used to perform the "Water absorption rate test method for superabsorbent polymers" according to JIS K7224-1996.

Unless otherwise specified, the dimensions of each part refer to the dimensions in the unfolded state, not the natural length state.

If no specification is given regarding the environmental conditions for a test or measurement, the test or measurement shall be performed in a test room or equipment under standard conditions (the test location shall be a temperature of 23±1°C and a relative humidity of 50±2%).

The present invention is not limited to tape-type disposable diapers as in the above example, but can be used for all disposable diapers such as pad-type and pants-type diapers, as long as they have rise-up gathers, and can also be used for other absorbent articles such as sanitary napkins. In particular, for disposable diapers for low birth weight infants, a soft fit, even if weak, is preferable rather than a firm fit. Therefore, the rise-up gathers with the above-mentioned free portion are suitable for disposable diapers for low birth weight infants.

11...liquid-impermeable sheet, 12...exterior nonwoven fabric, 12T...target portion, 13...connecting tape, 13A...connecting portion, 30...top sheet, 50...absorbent element, 56...absorbent body, 56n...constricted portion, 58...packaging sheet, 60...rise gathers, 61...inside elastic member, 62...gathered sheet, 62f...outside layer, 62n...inside layer, 63...gathered elastic member, 64...outside elastic member, 65...root portion, 66...main body portion, 67...front end portion, 68...middle portion, 69...rear end portion, BP...fixed portion, FP...free portion, LD...front-rear direction, M...crotch portion, WD...width direction.

Claims (6)

An absorber;
A liquid-permeable top sheet disposed on the front side of the absorbent body;
and rising gathers provided on both sides of the surface of the top sheet in the width direction,
The rising gathers have a root portion attached to the outside in the width direction of an imaginary line that passes through a blocking position on both sides in the width direction of the surface of the top sheet and continues in the front-rear direction, and a main body portion that extends inward in the width direction from an inner edge in the width direction of the root portion without being folded back,
The main body portion has a front end portion and a rear end portion having a fixing portion fixed to the top sheet, and an intermediate portion located between the front end portion and the rear end portion and not fixed to the top sheet,
A gather elastic member having an elongated shape along the front-rear direction is attached to at least the tip of the intermediate portion,
the intermediate portion is contracted together with the gathered elastic member by a contractile force of the gathered elastic member and is stretchable together with the gathered elastic member;
A free portion that is not fixed to the top sheet is provided at an inner end in the width direction of at least one of the front end portion and the rear end portion so as to continue from the intermediate portion, and the front end portion and the rear end portion other than the free portion are fixed portions,
The width of the free portion is 1/6 to 1/3 of the width of the intermediate portion, and the dimension of the free portion in the front-to-rear direction is 1 to 9.5 times the width of the free portion.
An absorbent article characterized by: The width of the free portion is 3.5 mm or more,
the intermediate portion has the gathered elastic member in a tip side region having a width equal to the width of the free portion, and does not have the gathered elastic member in any other region than the tip side region;
The absorbent article of claim 1. Among the regions overlapping the back side of the intermediate portion in an expanded state, a base portion side region having a width equal to the width of the fixing portion has an elongated inside elastic member extending along the front-rear direction on the back side of the top sheet,
The base portion side region is contracted together with the inside elastic member due to a contractile force of the inside elastic member, and is also stretchable together with the inside elastic member.
3. The absorbent article according to claim 1 or 2. The absorbent body has a narrowed portion in the middle in the front-rear direction, the narrowed portion being narrower than both front and rear ends of the absorbent body,
The inside elastic member is disposed so as to pass through the constricted portion.
The absorbent article according to claim 3. Both the front end and the rear end have the free portion;
The width of the free portion of the front end portion is wider than the width of the free portion of the rear end portion.
The absorbent article according to any one of claims 1 to 4. Disposable diapers for low birth weight babies
The absorbent article according to any one of claims 1 to 5.

Images