JP2018164633A5 - - Google Patents

Description

Absorbent articles

  The present invention relates to an absorbent article.

  In the case of absorbent articles such as disposable diapers and sanitary napkins, it is generally better that the amount of absorbable articles is large. As is well known, the absorbable amount of an absorbent article is determined by the material of the absorbent element and its content. Thus, for example, in order to increase the absorbable amount in an absorbent element comprising a general absorbent with pulp fibers and superabsorbent polymer particles integrated, increase the amount of pulp in the absorbent or It is common to increase the content. Moreover, it is also widely performed that the absorber has a two-layer structure.

  However, if the amount of pulp in the absorber is increased or simply a two-layer structure (see, for example, Patent Documents 1 and 2), the thickness of the absorber increases, leading to deterioration in wearing feeling and the like. Further, when the content of the superabsorbent polymer particles is increased, the entanglement between the pulp fibers is weakened, so that the strength of the absorbent body is weakened and the shape is liable to collapse.

  Furthermore, the amount of absorbable is maximized when all of the absorber is effectively used for absorption, but in reality, even if it is absorbed repeatedly for multiple excretion, the entire absorber is absorbed. Since the excretory fluid does not diffuse evenly, it is not possible to use up all of the absorber for absorption. That is, in order to increase the absorbable amount, it is necessary to improve not only the absorber material and its content but also the diffusibility. As measures for improving diffusibility, it is known to add a sheet for improving diffusibility on the absorber or to provide a slit in the absorber, but the former increases the number of members and increases the thickness. In terms of causing an increase, the latter is not a preferable measure in terms of reducing the absorbable amount.

JP 2006-167196 A JP 2012-034715 A

  Then, the main subject of this invention exists in improving the amount which can be absorbed, etc., preventing the strength reduction of an absorber and the increase in the thickness of an absorber.

The typical embodiments of the present invention that have solved the above problems are as follows.
<First aspect>
A lower absorbent element;
An upper absorbent element disposed above the lower absorbent element,
The upper absorbent element is disposed in the middle in the front-rear direction of the lower absorbent element and in the middle of the width direction of the lower absorbent element,
The upper absorbent element is a laminate having a first nonwoven layer, a second nonwoven layer, and superabsorbent polymer particles held between the first nonwoven layer and the second nonwoven layer,
The upper absorbent element has a joint where the upper absorbent element and the lower absorbent element are joined at both ends in the width direction of the upper absorbent element, and is located between the joined parts, and the entire longitudinal direction of the upper absorbent element The upper absorbent element and the lower absorbent element have a non-joined portion that is not joined,
An absorbent article characterized by the above.

(Function and effect)
In this aspect, during excretion, the excretion fluid supplied to the upper absorbent element penetrates and diffuses into the upper absorbent element, and a part is absorbed by the superabsorbent polymer particles in the upper absorbent element, and the rest is the superabsorbent polymer. It penetrates and diffuses without being absorbed by the particles and goes to the lower absorbent element. Here, since there are many gaps between the upper absorbent element and the lower absorbent element in the non-joined part, and the excretion liquid does not easily migrate from the upper absorbent element to the lower absorbent element, the excretory liquid in the upper absorbent element diffuses to the surroundings. This facilitates the supply of excretory fluid to the lower absorbent element. That is, in addition to the increase in the absorbable amount by the superabsorbent polymer particles of the upper absorbent element, the absorbable amount can be increased by improving the diffusibility. Moreover, since the upper absorbent element is mainly composed of non-woven fabric, it has high strength. Furthermore, since the upper absorbent element increases the absorbable amount by the superabsorbent polymer particles, the increase in thickness is very small even if the absorbable amount is remarkably increased.

<Second aspect>
The superabsorbent polymer particles contained in the upper absorbent element are fixed to at least one of the first nonwoven fabric layer and the second nonwoven fabric layer,
The absorbent article of a 1st aspect.

(Function and effect)
The upper absorbent element having the structure as in this aspect has improved rigidity when the superabsorbent polymer particles absorb excretory fluid and expands, and the gap between the upper absorbent element and the lower absorbent element is easily maintained after absorption. , Excellent in diffusibility upon repeated absorption.

<Third Aspect>
The upper absorbent element is a folded portion whose both side portions are folded downward, the folded portion and the non-folded portion of the upper absorbent element are not joined, and the joined portion is the folded portion. The lower absorbent element is joined,
The absorbent article of the 1st or 2nd aspect.

(Function and effect)
When the upper absorbent element has a folded portion as in this embodiment and the folded portion serves as a leg and the other portions float from the lower absorbent element, excretion from the upper absorbent element to the lower absorbent element Liquid transfer is less likely to occur, and diffusibility is further improved. In particular, in the form in which the superabsorbent polymer particles contained in the upper absorbent element are adhered to at least one of the first nonwoven fabric layer and the second nonwoven fabric layer, the superabsorbent polymer particles absorb the excretory fluid and expand when absorbed. Not only is the rigidity of the element improved, but the expansion force of the superabsorbent polymer particles acts to restore the folded portion, so that the gap between the upper absorbent element and the lower absorbent element is larger after absorption, and More are formed, and the diffusibility at the time of repeated absorption is further improved.

<Fourth aspect>
The lower absorbent element is an aggregate of pulp fibers and superabsorbent polymer particles, or the aggregate is wrapped with a packaging sheet.
The absorbent article according to any one of the first to third aspects.

(Function and effect)
Aggregates of pulp fibers and superabsorbent polymer particles are widely used because the absorption rate can be secured by the superabsorbent polymer particles while ensuring the absorption rate by the pulp fibers, but this alone reduces the strength of the absorber. It is difficult to improve the absorbable amount while preventing an increase in the thickness of the absorber. On the other hand, by combining the above-mentioned upper absorbent elements, while effectively preventing the decrease in the strength of the absorber and the increase in the thickness of the absorber, the absorbable amount is improved and the absorption rate is secured. Can do.

<Fifth aspect>
The lower absorbent element has a recessed portion with a recessed upper surface or a penetrating portion extending vertically in the longitudinal direction, at least in the middle of the non-joining portion in the front-rear direction and the width direction.
The absorbent article according to any one of the first to fourth aspects.

(Function and effect)
Having such a recess or penetrating part ensures a gap between the upper absorbent element and the lower absorbent element, and only improves the diffusibility due to the delay in excretion fluid transfer from the upper absorbent element to the lower absorbent element. In addition, the excretory fluid that has migrated to the lower absorbent element is likely to diffuse in the front-rear direction along the recess or the penetration portion.

<Sixth aspect>
A portion that overlaps the non-bonded portion in the surface layer of the lower absorbent element contains a hydrophobic agent or a water repellent,
The absorbent article according to any one of the first to fifth aspects.

(Function and effect)
By having a process containing a hydrophobic agent or a water repellent as in this embodiment, the excretion fluid is less likely to migrate from the upper absorbent element to the lower absorbent element, and the diffusibility is further improved, which is preferable. In addition, it is also one preferable form that the hydrophobic effect or the water repellent effect in the portion containing the hydrophobic agent or the water repellent is lowered by contact with the excretory liquid.

<Seventh aspect>
The distance in the front-rear direction between the front edge of the upper absorbent element and the front edge of the lower absorbent element is 5 to 45% of the total length of the lower absorbent element,
The distance in the front-rear direction between the rear edge of the upper absorbent element and the rear edge of the lower absorbent element is 5 to 50% of the total length of the lower absorbent element,
The distance in the width direction between the side edge of the upper absorbent element and the side edge of the lower absorbent element is 5 to 50% of the total width of the lower absorbent element,
The width of the non-joining portion is 10 to 80% of the total width of the upper absorbent element.
The absorbent article according to any one of the first to sixth aspects.

(Function and effect)
The dimensions of the upper absorbent element, the lower absorbent element, and the non-joined portion may be determined as appropriate, but in the normal case, it is preferably within the scope of this embodiment.

  As described above, according to the present invention, there are advantages that the absorbable amount can be improved while preventing the strength of the absorber from decreasing and the thickness of the absorber from increasing.

It is a top view of the unfolding state which shows the inner surface of a tape type disposable diaper. It is a top view of the unfolded state which shows the outer surface of a tape type disposable diaper. FIG. 5 is a sectional view taken along line 5-5 of FIG. FIG. 6 is a sectional view taken along line 6-6 of FIG. (A) 7-7 sectional drawing of FIG. 1, (b) 8-8 sectional drawing of FIG. (A) The top view of a waist elastic sheet, (b) It is sectional drawing of a waist elastic sheet. FIG. 9 is a sectional view taken along line 9-9 in FIG. 1. It is sectional drawing of an upper absorption element. FIG. 5 is a sectional view taken along line 5-5 of FIG. It is sectional drawing which shows only the principal part.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In addition, although the dot pattern part in sectional drawing has shown the hot-melt-adhesive which joins each structural member, it replaces with a hot-melt adhesive, uses other adhesives, or welds, such as a heat seal and an ultrasonic seal. Needless to say, the bonding may be performed by using. In the following description, “front-rear direction LD (vertical direction)” means a direction connecting the ventral side (front side) and the back side (rear side), and “width direction WD” is a direction orthogonal to the front-rear direction. (Left-right direction).

  1-7 has shown an example of the tape type disposable diaper. This tape-type disposable diaper has a ventral part F extending forward from the front-rear direction center C and a dorsal part B extending rearward from the front-rear direction center C. A target sheet 20 provided on the outer surface of the surrounding part, and a connecting part 13A provided on both the left and right sides of the waist part of the back part B and connected to the target sheet 20 in a detachable manner. In the example shown in FIGS. 1 and 2, the waist portions of the ventral portion F and the dorsal portion B have wing portions WP that extend to the left and right sides (located to the side of the crotch side edge). The ventral part F and the dorsal part B have an intermediate part CP positioned between the left and right wing parts WP (in other words, the middle of the front-rear direction LD is narrowed so that the side edges are around the legs). Although it is a form, it is set as the form which does not have the wing part WP in both the ventral part F and the dorsal part B, or the dorsal part B has the wing part WP, but the ventral part F has the wing part WP. It can also be made into a form which does not have.

(Main unit)
In the example shown in FIGS. 1 and 2, the intermediate portion CP, the portion of the wing portion WP of the back portion B excluding a portion on the tip side, and the wing portion WP of the ventral portion F include the absorber 56 and the absorber 56. A sheet of the main body 10 having a liquid-permeable top sheet 30 covering the front side of the liquid and a liquid-impermeable sheet 11 covering the back side of the absorber 56 (in the illustrated example, the gather sheet 62, the liquid-impermeable sheet 11, And the exterior sheet 12). Although not shown, the intermediate portion CP is formed by the main body 10, and the wing portion WP of the back portion B and the wing portion WP of the ventral portion F are formed by parts different from the main body 10 attached to both sides of the main body 10. It may be formed.

  Further, the main body 10 has an end flap portion EF that does not have the absorber 56 and extends to the front side and the rear side from the absorber 56, and a side flap portion SF that does not have the absorber 56 and extends to the side than the absorber 56. And have. In addition, the code | symbol 10X shows the full width of the main body 10, and the code | symbol 10L has shown the full length of the main body 10 (it is equal to the full length of a diaper in the illustration form).

  More specifically, in the illustrated example, the entire outer surface of the main body 10 is formed by the exterior sheet 12, and the liquid-impermeable sheet 11 is fixed to the inner surface side by an adhesive such as a hot-melt adhesive, and this liquid Absorbing elements 40 and 50 including the absorber 56 and the top sheet 30 are laminated in this order on the inner surface side of the impermeable sheet 11. The top sheet 30 and the liquid-impermeable sheet 11 are rectangular in the illustrated example, and have slightly larger dimensions in the front-rear direction LD and the width direction WD than the absorbent elements 40, 50. The peripheral edge protruding from the side edge 50 and the peripheral edge protruding from the side edge of the absorbent elements 40 and 50 in the liquid-impermeable sheet 11 are fixed by a hot melt adhesive or the like. This portion becomes a part of the end flap portion EF and the side flap portion SF.

  Furthermore, rising gathers 60 and 60 that rise on the skin side of the wearer are provided on both sides of the surface of the main body 10 in the width direction WD, and the gather sheets 62 and 62 that form the rising gathers 60 and 60 are the tops. The sheet 30 extends from both side portions to the side flap portions SF.

Hereinafter, the material and the characteristic part of each part are demonstrated in order.
(Exterior sheet)
The exterior sheet 12 is provided so that the back surface of the disposable diaper has a touch and appearance like cloth. The exterior sheet 12 is preferably a non-woven fabric, but is not limited thereto. The type of the nonwoven fabric is not particularly limited, and for example, synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, and polyamides, recycled fibers such as rayon and cupra, and natural fibers such as cotton are used as material fibers. As a processing method, a spunlace method, a spunbond method, a thermal bond method, an air-through method, a needle punch method, or the like can be used. However, a long-fiber nonwoven fabric such as a spunbond nonwoven fabric, an SMS nonwoven fabric, or an SMMS nonwoven fabric is preferable in that both the touch and strength can be achieved. In addition to using a single nonwoven fabric, a plurality of nonwoven fabrics can be used. In the latter case, the nonwoven fabrics 12 are preferably bonded to each other with a hot melt adhesive or the like. When using a nonwoven fabric, the fabric weight is preferably 10 to 50 g / m ² , particularly 15 to 30 g / m ² . The exterior sheet | seat 12 can also be abbreviate | omitted and it can be set as the form which the liquid-impermeable sheet | seat 11 exposes to the back surface of a disposable diaper.

(Liquid impervious sheet)
The material of the liquid-impermeable sheet 11 is not particularly limited. For example, the liquid-impermeable sheet 11 is substantially made of an olefin resin such as polyethylene or polypropylene, a laminated nonwoven fabric obtained by laminating a nonwoven fabric on a polyethylene sheet, or a waterproof film. Non-woven fabrics that ensure liquid impermeability (in this case, liquid impervious sheets are composed of waterproof films and non-woven fabrics). Of course, in addition to this, materials having liquid impermeability and moisture permeability which have been used and used in recent years from the viewpoint of preventing stuffiness can also be exemplified. As the sheet of the material having liquid impermeability and moisture permeability, for example, an inorganic filler is kneaded in an olefin resin such as polyethylene or polypropylene, and the sheet is formed, and then stretched in a uniaxial or biaxial direction. Examples of the microporous sheet obtained in this way can be given. In addition, non-woven fabric using micro-denier fiber, strengthening leak-proofing by reducing the voids of the fiber by applying heat or pressure, and applying water-repellent resin or hydrophobic resin or water repellent. A sheet that is liquid-impermeable without using a film can also be used as the liquid-impermeable sheet 11.

  The liquid-impermeable sheet 11 in the illustrated example is slightly wider than the top sheet 30 and narrower than the exterior sheet 12, but the liquid-impermeable sheet 11 is not limited to this. The width can be changed as appropriate, for example.

  At least one of the front and back sides of the liquid-impermeable sheet 11 may be provided with decorative prints 11a and 11b that are visible from the outer surface. The types, shapes, and dimensions of the decorative prints 11a and 11b are not particularly limited. As the decorative prints 11a and 11b, continuous decorative prints 11a composed of a large number of structural units such as characters (size, brand name, manufacturer name, design name, etc.) regularly repeated in the front-rear direction LD and the width direction WD, and the design. In addition, there is an intermittent decorative print 11b that is arranged only on one or both of the front and rear of the product, such as a product logo, a character picture, a photograph, etc., and either one or both can be adopted.

(Top sheet)
As the top sheet 30, a liquid permeable material such as a porous or non-porous nonwoven fabric or a porous plastic sheet can be used. The nonwoven fabric is not particularly limited as to what the raw fiber is. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of them. Etc. can be illustrated. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method. For example, the spun lace method is a preferable processing method for obtaining flexibility and drapeability, and the thermal bond method is for obtaining bulkiness and softness.

  The top sheet 30 may be composed of one sheet or may be composed of a laminated sheet obtained by bonding two or more sheets. Similarly, the top sheet 30 may be composed of one sheet or two or more sheets in the planar direction.

  Although the top sheet 30 in the illustrated example extends to the side of the side edge of the absorbent body 56, the top sheet 30 is not limited to this, and may extend to the side edge of the exterior sheet 12, and in a form having a rising gather. As long as it extends to the root portion of the gathering up, it may be changed as appropriate, such as extending only to the inner side in the width direction from the side edge of the absorber.

(Intermediate sheet)
In order to move excrement that has permeated through the top sheet 30 to the absorbent elements 40 and 50 and prevent reversal, an intermediate sheet (also referred to as a second sheet) (not shown) may be provided between the top sheet 30 and the absorbent elements 40 and 50. it can. This intermediate sheet not only improves the absorption performance by the absorber by quickly transferring the excrement to the absorber, but also prevents the excretion of the absorbed excrement from returning from the absorber and improves the surface feel of the top sheet 30. To do. The intermediate sheet can be omitted.

  The material of the intermediate sheet is not particularly limited, and for example, the same material as that of the top sheet 30 can be used. The intermediate sheet 40 is preferably bonded to the top sheet 30. When heat embossing or ultrasonic welding is used for the bonding, the intermediate sheet preferably has a melting point similar to that of the top sheet 30. Further, considering the permeation of the solid content in the stool, the fineness of the fiber used for the intermediate sheet 40 is preferably 5.0 to 7.0 dtex, but the liquid residue in the top sheet 30 increases. On the other hand, when the fineness of the fiber used for the intermediate sheet is 1.0 to 2.0 dtex, the liquid residue of the top sheet 30 is hardly generated, but the solid content of the stool is hardly transmitted. Therefore, it is preferable that the fiber of the nonwoven fabric used for the intermediate sheet has a fineness of about 2.0 to 5.0 dtex. The intermediate sheet may be a mesh film in which a large number of pores are provided in a film material such as polyethylene.

  The intermediate sheet may be disposed in the center shorter than the width of the absorbent elements 40 and 50, or may be provided over the entire width. The length of the intermediate sheet in the longitudinal direction may be the same as the entire length of the diaper, may be the same as the length of the absorbent elements 40 and 50, or may be within a short length range centered on the region that receives the liquid.

(Absorption element)
The absorption elements 40 and 50 are parts that absorb and retain excretory fluid such as urine and loose stool liquid, and have a lower absorption element 50 and an upper absorption element 40 disposed on the upper side.

(Lower absorption element)
In the illustrated example, the lower absorbent element has an absorbent body 56 and a packaging sheet 58 that wraps the entire absorbent body 56. The packaging sheet 58 can be omitted as necessary, for example, when the absorbent body 56 is excellent in shape maintenance, and in this case, the lower absorbent element 50 is composed only of the absorbent body 56. The lower absorbent element 50 can be adhered to the inner surface of the liquid-impermeable sheet 11 via an adhesive such as a hot melt adhesive on the back surface.

(Absorber)
The absorber 56 can be formed of an aggregate of fibers. As this fiber assembly, a filament assembly obtained by opening, as necessary, synthetic fiber tows (fiber bundles) such as cellulose acetate as well as short fibers such as cotton-like pulp and synthetic fibers Can also be used. The fiber basis weight can be set to, for example, about 100 to 300 g / m ² when cotton-like pulp or short fibers are stacked, and in the case of a filament aggregate, for example, about 30 to 120 g / m ^2. Can do. The fineness in the case of a synthetic fiber is 1-16 dtex, for example, Preferably it is 1-10 dtex, More preferably, it is 1-5 dtex. In the case of a filament aggregate, the filament may be a non-crimped fiber, but is preferably a crimped fiber. The degree of crimp of the crimped fibers can be, for example, about 5 to 75, preferably 10 to 50, and more preferably about 15 to 50 per 2.54 cm . Further, a crimped fiber that is uniformly crimped is often used. It is preferable to disperse and hold superabsorbent polymer particles in the absorber 56.

  It is preferable that the absorbent body 56 has a rectangular shape as in the illustrated example, and an hourglass shape having a narrow portion narrower than both the front and rear sides in the middle in the front-rear direction, because the fit around the legs is improved.

  In addition, the size of the absorbent body 56 can be appropriately determined as long as it extends to the front, rear, left and right of the urination port position, but preferably extends to the vicinity of the periphery of the main body 10 in the front-rear direction LD and the width direction WD.

(Superabsorbent polymer particles)
The absorber 56 can contain superabsorbent polymer particles in a part or all thereof. Superabsorbent polymer particles include “powder” in addition to “particles”. As the superabsorbent polymer particles 54, those used in this type of absorbent article can be used as they are. The particle diameter of the superabsorbent polymer particles is not particularly limited, but for example, screening using a standard sieve of 500 μm (JIS Z8801-1: 2006) (shaking for 5 minutes), and particles falling under the screen by this screening When sieving (shaking 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 180 μm standard sieve It is desirable that the proportion of particles remaining on the surface is 60% by weight or more.

  The material of the superabsorbent polymer particles can be used without any particular limitation, but those having a water absorption of 40 g / g or more are suitable. High-absorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, and sodium carboxymethylcellulose crosslinks. Or an acrylic acid (salt) polymer can be used. As the shape of the superabsorbent polymer particles, a commonly used granular material is suitable, but other shapes can also be used.

  Further, as the superabsorbent polymer particles, those having a gel strength of 1000 Pa or more are preferably used. Thereby, even if it is a case where it is set as the bulky absorber 56, the sticky feeling after liquid absorption can be suppressed effectively.

The basis weight of the superabsorbent polymer particles can be appropriately determined according to the amount of absorption required for the use of the absorber 56. Therefore, although it cannot be said unconditionally, it can be 50 to 350 g / m ² . If the amount of polymer is less than 50 g / m ^2, it is difficult to secure the absorption amount. When it exceeds 350 g / m ² , the effect is saturated.

  The ratio of the fibers and the superabsorbent polymer particles in the absorbent body 56 is not particularly limited, but when the weight ratio of the fibre: superabsorbent polymer particles is 50:50 to 20:80, the comparison is made with the same area and the same amount of absorption. A thinner absorber 56 can be obtained. In this case, the thickness 56t of the absorber 56 is not particularly limited, but can be 3 to 15 mm.

  The content of the superabsorbent polymer particles can be changed in the thickness direction of the absorbent body 56 or the direction along the plane.

(Packaging sheet)
When the packaging sheet 58 is used, as the material, tissue paper, particularly crepe paper, non-woven fabric, polylaminated non-woven fabric, a sheet with small holes, or the like can be used. However, it is desirable that the superabsorbent polymer particles be a sheet that does not escape. When a nonwoven fabric is used in place of the crepe paper, a hydrophilic SMS nonwoven fabric (SMS, SSMMS, etc.) is particularly suitable, and the material can be polypropylene, polyethylene / polypropylene composite material, or the like. The basis weight is preferably 5 to 40 g / m ² , particularly 10 to 30 g / m ² .

  The packaging form of the packaging sheet 58 can be determined as appropriate, but from the viewpoint of ease of manufacture and prevention of leakage of the superabsorbent polymer particles from the front and rear end edges, the cylinder is formed so as to surround the front and back surfaces and both side surfaces of the absorbent body 56. It is preferable that the front and rear edge portions protrude from the front and rear of the absorbent body 56, and the overlapping portion and the overlapping portion of the front and rear protruding portions are joined by a joining means such as hot melt adhesive or material welding.

(Upper absorption element)
As shown in the example shown in FIG. 8, the upper absorbent element 40 has a first non-woven fabric layer 41, a second non-woven fabric layer 42, and a high absorption held between the first non-woven fabric layer 41 and the second non-woven fabric layer 42. It is a laminated body having conductive polymer particles 43. Adjacent layers in this laminate are preferably joined together by a hot melt adhesive or the like. The first nonwoven fabric layer 41 and the second nonwoven fabric layer 42 are not particularly limited, but are bulky air-through in that the feel of the superabsorbent polymer particles is not easily transmitted to the skin and a space where the superabsorbent polymer particles swell can be secured. Nonwoven fabric is preferred. The fineness and basis weight of the fibers in the first nonwoven fabric layer 41 and the second nonwoven fabric layer 42 are not particularly limited, but the fineness is about 2.0 to 5.0 dtex, and the basis weight is about 15 to 35 g / m ^2. It is preferable to do. The same nonwoven fabric may be used as the first nonwoven fabric layer 41 and the second nonwoven fabric layer 42, or different nonwoven fabrics may be used.

As the superabsorbent polymer particles 43 contained in the upper absorbent element 40, the same particles as those of the lower absorbent element 50 can be used. Among them, those having excellent liquid permeability, specifically, a water absorption rate of 20 to 35 seconds. And the thing whose absorption amount is 50-70 g / g is preferable. On the other hand, the superabsorbent polymer particles 43 included in the lower absorbent element 50 are preferably those having a large absorption amount, specifically, those having a water absorption rate of 60 to 80 seconds and an absorption amount of 50 to 70 g / g. The basis weight of the superabsorbent polymer particles 43 in the upper absorbent element 40 can be determined as appropriate, but is preferably about 50 to 200 g / m ² .

  As long as the superabsorbent polymer particles 43 are held between the first nonwoven fabric layer 41 and the second nonwoven fabric layer 42, the upper absorbent element 40 is disposed inside at least one of the first nonwoven fabric layer 41 and the second nonwoven fabric layer 42. The superabsorbent polymer particles 43 may be contained. For example, in the example shown in FIG. 8, all of the superabsorbent polymer particles 43 of the upper absorbent element 40 are held between the first nonwoven fabric layer 41 and the second nonwoven fabric layer 42, but some of the superabsorbent polymer particles 43 are retained. The polymer particles 43 may be mixed in the first nonwoven fabric layer 41 and the second nonwoven fabric layer 42. Although not shown, a nonwoven fabric layer that holds the superabsorbent polymer particles 43 may be interposed between the first nonwoven fabric layer 41 and the second nonwoven fabric layer 42.

  Since the upper absorbent element 40 also functions to improve diffusibility, the upper absorbent element 40 is disposed in the middle of the front and rear direction LD of the lower absorbent element 50 and in the middle of the width direction WD of the lower absorbent element 50. Specifically, the distance D1 in the front-rear direction LD between the front edge of the upper absorbent element 40 and the front edge of the lower absorbent element 50 is 5 to 45% of the total length 50L of the lower absorbent element 50, and the upper absorbent element 40 The distance D2 in the front-rear direction LD between the rear edge of the lower absorbent element 50 and the rear edge of the lower absorbent element 50 is 5 to 50% of the total length 50L of the lower absorbent element 50, and the side edge of the upper absorbent element 40 and the lower absorbent element 50 The distance D3 in the width direction WD from the side edge is preferably 5 to 50% of the entire width 50W of the lower absorbent element 50.

  Characteristically, the upper absorbent element 40 has joints 80 where the upper absorbent element 40 and the lower absorbent element 50 are joined at both ends in the width direction WD, and is located between the joints 80. The upper absorbent element 40 and the lower absorbent element 50 have a non-joined portion 81 where the upper absorbent element 40 and the lower absorbent element 50 are not joined over the entire front and rear direction LD of the upper absorbent element 40. The width of the non-joint portion 81 is not particularly limited, but is preferably 10 to 80% of the total width 40W of the upper absorbent element 40. The joint 80 can be provided intermittently in the front-rear direction LD as well as continuously provided in the front-rear direction LD as in the illustrated example.

  At the time of excretion, the excreted liquid supplied to the upper absorbent element 40 permeates and diffuses into the upper absorbent element 40, and a part is absorbed by the superabsorbent polymer particles 43 in the upper absorbent element 40, and the rest is the superabsorbent polymer. The particles 43 penetrate and diffuse without being absorbed by the particles 43, and travel toward the lower absorbent element 50. Here, as shown by the arrow in FIG. 10, the flow of the excretion liquid Li, the non-joint portion 81 has a large gap between the upper absorbent element 40 and the lower absorbent element 50, and excretion from the upper absorbent element 40 to the lower absorbent element 50. Since the transfer of the liquid Li does not easily occur, the excretion liquid Li in the upper absorption element 40 is easily diffused to the surroundings, and the supply of the excretion liquid to the lower absorption element 50 becomes wider. That is, in addition to the increase in the absorbable amount by the superabsorbent polymer particles 43 of the upper absorbent element 40, an increase in the absorbable amount can be achieved by improving the diffusibility. Moreover, since the upper absorbent element 40 is mainly composed of a nonwoven fabric, the strength is high. Further, since the upper absorbent element 40 increases the absorbable amount by the superabsorbent polymer particles 43, the increase in thickness is very small even if the absorbable amount is remarkably increased.

  As shown in FIG. 8, the superabsorbent polymer particles 43 included in the upper absorbent element 40 are preferably fixed to at least one of the first nonwoven fabric layer 41 and the second nonwoven fabric layer 42. The upper absorbent element 40 having such a structure is improved in rigidity when the superabsorbent polymer particles 43 absorb the excretory fluid and expands, and the gap between the upper absorbent element 40 and the lower absorbent element 50 is easily maintained after the absorption. Therefore, it becomes excellent in diffusibility during repeated absorption. In addition, the upper absorbent element 40 having such a structure, for example, applies the hot melt adhesive 44 continuously or intermittently over the entire surface of one of the first nonwoven fabric layer 41 and the second nonwoven fabric layer 42, and the application thereof. After the superabsorbent polymer particles 43 are dispersed on the surface, the first nonwoven fabric layer 41 and the second nonwoven fabric layer 42 can be bonded together.

  Further, as in the example shown in FIG. 3 and FIG. 10, both side portions of the upper absorbent element 40 are folded portions 45 that are folded downward, and the folded portion 45 and the non-folded portion 46 of the upper absorbent element 40. Is not joined, and the joining portion 80 between the upper absorbent element 40 and the lower absorbent element 50 is preferably a joined part of the folded portion 45 and the lower absorbent element 50. The width of the folded portion 45 can be about 1.0 to 2.5 times the width of the joint 80. As described above, when the upper absorbent element 40 has the folded portion 45 and the folded portion 45 serves as a leg and the other portions float from the lower absorbent element 50, the upper absorbent element 40 to the lower absorbent element Migration of excretory fluid to 50 becomes more difficult to occur, and the diffusibility is further improved. In particular, in the form in which the superabsorbent polymer particles 43 included in the upper absorbent element 40 are adhered to at least one of the first nonwoven fabric layer 41 and the second nonwoven fabric layer 42, the superabsorbent polymer particles 43 absorb the excretory fluid. When expanded, not only the rigidity of the upper absorbent element 40 is improved, but also the expansion force of the superabsorbent polymer particles 43 acts to restore the folded portion 45, so that the upper absorbent element 40 and the lower absorbent are absorbed after absorption. The gap with the element 50 is larger and more formed, and the diffusibility upon repeated absorption is further improved.

  Considering the role of the upper absorbent element 40 described above, the lower absorbent element 50 is an aggregate of pulp fibers and superabsorbent polymer particles 43, or an aggregate of these aggregates wrapped in a wrapping sheet 58 as shown in the illustrated example. It is preferable. By combining such a lower absorbent element 50 and the upper absorbent element 40 described above, effectively reducing the strength of the absorbent body 56 and increasing the thickness of the absorbent body 56, while improving the absorbable amount, Absorption rate can also be secured.

  Further, in consideration of the role of the upper absorbent element 40 described above, the lower absorbent element 50 is a concave portion having an indented upper surface extending in the front-rear direction LD at least between the front-rear direction LD and the width direction WD in the non-joint portion 81. 51 (or a penetrating portion penetrating in the vertical direction. The same shall apply hereinafter). This ensures a gap between the upper absorbent element 40 and the lower absorbent element 50, and not only improves the diffusibility due to the delay of excretory fluid transfer from the upper absorbent element 40 to the lower absorbent element 50, but also lower absorbent. The excretory fluid transferred to the element 50 is likely to diffuse in the front-rear direction LD along the recess 51. As long as at least a part of the recess 51 is located at least in the middle of the front-rear direction LD and the width direction WD in the non-joint part 81, the recess 51 may extend to at least one front-rear side than the upper absorbent element. As an example, when the front end of the lower absorbent element 50 is 0% and the rear end of the lower absorbent element 50 is 100%, the front end of the recess 51 is located in the range of 10 to 30%, and the rear end of the recess 51 The end is preferably located in the range of 40-80%. In addition to providing one recess 51 at the center in the width direction WD, a plurality of recesses 51 can be provided at intervals in the width direction WD, such as one on each of the left and right sides. When a plurality of the recesses 51 are provided at intervals in the width direction WD, the position in the width direction of the recesses 51 is preferably symmetrical. Further, the interval in the width direction WD of the recesses 51 can be about 10 to 60% of the width of the lower absorbent element 50. The width of the recess 51 can be about 3 to 15% of the width of the lower absorbent element 50. Further, the depth of the recess 51 can be about 50 to 100% of the thickness of the lower absorbent element 50. In the case where a plurality of the recesses 51 are provided at intervals in the width direction WD, it is only necessary that at least one of them is located at a position where it overlaps with the non-joining part 81. In the example shown in FIG. 3, a slit is provided in the absorbent body 56 of the lower absorbent element 50, and the recess 51 is formed by dropping the packaging sheet 58 into the slit, but as in the example shown in FIG. 9. The recess 51 may be formed by embossing so as to be recessed from the upper side of the packaging sheet 58 into the absorbent body 56.

Further, it is also preferable that a hydrophobic agent or a water repellent agent is contained in a portion overlapping the non-joining portion 81 in the surface layer of the lower absorbent element 50 (in the illustrated example, the portion located on the upper side of the absorbent body 56 in the packaging sheet 58). It is a form. Thus, it is preferable to have a process containing a hydrophobic agent or a water repellent agent because the excretion of the excretion fluid from the upper absorbent element 40 to the lower absorbent element 50 is less likely to occur and the diffusibility is further improved. In addition, it is also one preferable form that the hydrophobic effect or the water repellent effect in the portion containing the hydrophobic agent or the water repellent is lowered by contact with the excretory liquid. As such a hydrophobic agent or water repellent, C ₁₂ -C ₂₂ fatty alcohols, vaseline, liquid paraffin, silicone oil, animal and vegetable oils (olive oil, Hooba oil, safflower oil, etc. squalane and squalene), diglyceride, triglyceride, paraffin Wax, C ₁₂ -C ₂₂ fatty acid, silicone, silicone resin and the like can be used.

(Side gather)
As shown in FIGS. 2 and 3, in order to improve the fit of the portion around the leg located in the middle of the front-and-rear direction LD of the side portion of the main body 10, the sheet layer (example shown in the figure) in the middle of the front-and-rear direction LD of the side flap portion SF. Then, a side elastic member 70 extending in the front-rear direction LD is provided between the gather sheet 62 and the liquid-impermeable sheet 11, and the portion having the side elastic member 70 is moved back and forth by expansion and contraction of the side elastic member 70. It expands and contracts in the direction LD.

(Get up gather)
In order to block urine and soft stool that move laterally on the top sheet 30 and prevent side leakage, the surface of the disposable diaper rises from the side of the top sheet 30 to the skin side on both sides in the width direction WD (protrusion) The rising gather 60 is provided over the entire front-rear direction.

  The rising gather 60 in the illustrated example has a root portion 65 fixed to a region including the side flap portion SF, a protruding portion 66 extending from the root portion 65, and both ends in the front-rear direction of the protruding portion are fixed in a lying state. Gathered portion 67, unfixed rising portion 68 located between the front and rear lodging portions of the projecting portion 66, and gather elasticity elastically fixed to at least the tip portion of the rising portion 68 in the front-rear direction. Member 63. The rising gather 60 is formed by a gather sheet 62 folded at the tip, and the gather sheet 62 can be made of a water-repellent nonwoven fabric, and the gather elastic member 63 is made of an elongated elastic member such as thread rubber. be able to. As shown in FIG. 1 and FIG. 2, the gather elastic members 63 can be provided in plural numbers, spaced apart from each other, or one each. Although the elongation rate of the part which has the gather elastic member 63 is not specifically limited, 150-350% is preferable in normal cases, and 200-300% is more preferable.

  The root portion 65 of the rising gather 60 in the illustrated example is provided only in the side flap portion SF, and is joined to the side portion of the liquid-impermeable sheet 11 and the side portion of the exterior sheet 12, but the side flap portion SF. May extend to the side of the region overlapping the absorber 56.

  The projecting portion 66 of the rising gather 60 has a lying portion at both ends in the front-rear direction LD, but the portion between them is an unfixed rising portion 68, and this rising portion 68 contracts the gather elastic member 63. It comes to stand by force. When the diaper is mounted, the diaper is mounted on the body in the shape of a boat, and the contracting force of the gather elastic member 63 acts. . As a result, so-called side leakage from around the legs is prevented.

(Waist elastic sheet)
It is preferable that a belt-like waist stretchable sheet 90 is provided around the trunk portion of the main body 10 in the back side portion B, and the back side portion B is elastically stretched in the width direction WD. The waist stretchable sheet 90 has non-stretchable regions 96 at both ends in the width direction WD, and a portion between the non-stretchable regions 96 is an intermediate stretchable region 95 that stretches in the width direction WD. is there. The waist stretchable sheet 90 may be located only in the end flap portion EF, but when the waist stretchable sheet 90 is disposed so as to extend from the end flap portion EF to the rear end portion of the absorber 56 as illustrated, the absorber 56. This is preferable because the rear end is firmly pressed against the body.

  The waist elastic sheet 90 may use a sheet-like elastic member such as a rubber sheet, but it is preferable to use a nonwoven fabric from the viewpoint of air permeability. In this case, a sheet-like elastic member having air permeability such as a stretchable nonwoven fabric can be used. However, as shown in FIG. 6, a sheet layer 91 such as two nonwoven fabrics is pasted with an adhesive such as a hot melt adhesive. In addition, a material in which an elastic member 92 such as a perforated sheet, net, or elongated (thread or string) is fixed between the sheet layers 91 in a state of extending along the width direction WD is preferably used. . In this case, as the material of the sheet layer 91, the same material as the exterior sheet 12 can be used. The elongation rate of the elastic member 92 is preferably about 150 to 250%. In addition, when an elongated member (thread-like or string-like) is used as the elastic member 92, it is preferable to provide about 5 to 15 pieces having a thickness of 420 to 1120 dtex with a spacing of 3 to 10 mm in the front-rear direction.

  Although the width of the waist elastic sheet 90 can be determined as appropriate, it is preferably a width extending between the left and right side flap portions SF as shown in the illustrated example, and particularly a width extending between the left and right wing portions WP. It is preferable. As specific dimensions, the width of the waist elastic sheet 90 is preferably about 80 to 95% of the total width 10X of the main body 10.

  Although the dimensions of the intermediate stretchable region 95 and the non-stretchable region 96 in the waist stretchable sheet 90 can be appropriately determined, the width of the intermediate stretchable region 95 is 45 to 100% of the width between the connecting portions 13A of the left and right fastener assemblies 13 described later. The width of the non-stretchable region 96 is preferably about 5 to 20 mm in order to prevent shrinkage or turning-up when attached to the main body 10. The non-stretchable region 96 may be a region that does not have the elastic member 92. However, as described in Patent Document 3, the elastic member 92 is attached over the intermediate stretchable region 95 and the non-stretchable region 96, and in the non-stretchable region 96, the elastic member 92 is attached. The elastic member 92 may remain in the non-stretchable region 96, for example, or may be structured so as not to stretch or contract at all.

  Further, the elastic member 92 may be arranged so that a part of the elastic member 92 crosses the absorber 56. However, as shown in FIG. Therefore, if the structure is such that the elastic member 92 remains but hardly or does not expand or contract at all, the rear end portion of the absorbent body 56 does not contract in the width direction, so that the fit is further improved.

  The waist stretchable sheet 90 is arranged between the liquid-impermeable sheet 11 and the absorbent elements 40 and 50 in the illustrated form, but is not particularly limited to this arrangement. For example, the waist stretchable sheet 90 may be disposed between the liquid-impermeable sheet 11 and the exterior sheet 12 or may be provided outside the exterior sheet 12. When the exterior sheet 12 is formed by stacking a plurality of sheet layers, the entire waist elastic sheet 90 may be provided between the sheet layers of the exterior sheet 12.

(Fastener assembly)
13 A of connection parts are provided in the fastener assembly 13 each attached to the right-and-left both sides of the main body 10 in the trunk periphery part of the back side part B, respectively. More specifically, the fastener assembly 13 includes a fastener fixing portion 13B fixed to the back surface of the main body 10, and an unfixed fastener free portion 13F extending laterally from the fastener fixing portion 13B. A connecting portion 13A is provided at the tip of the fastener free portion 13F. Unlike the example of illustration, 13 A of connection parts may be provided in the right-and-left both sides of the main body 10 in a trunk periphery part.

  As connection part 13A, you may provide an adhesive layer other than providing the hook material (male material) of a mechanical fastener (surface fastener). The hook material has a large number of engaging protrusions on its connecting surface, and the engaging protrusions are (A) letter-shaped, (B) J-shaped, (C) mushroom-shaped, (D) There are T-shape, (E) double J-shape (shape in which J-shape is joined back to back), etc., but any shape may be used. When the diaper is worn, the wing portion WP is turned from both sides of the waist to the outer surface of the abdominal portion F, and the connecting portion 13A of the wing portion WP is connected to a proper position on the outer surface of the abdominal portion F.

  As shown in FIG. 1, the fastener assembly 13 is not only a non-stretchable type (tab type) having no side stretchable region, but also at least a portion between the fastener fixing portion 13B and the connecting portion 13A. An expansion / contraction type (side panel type) having a side expansion / contraction region extending / contracting in the direction WD can also be adopted.

The structure of the non-expandable fastener assembly 13 is not particularly limited, and a known structure can be adopted. The non-stretchable fastener assembly 13 in the illustrated example includes a support piece 13C protruding from the side edge of the main body 10 and a connecting portion provided in the width direction WD intermediate portion of the support piece 13C protruding from the side edge of the main body 10. 13A. As a material of the support piece 13C, a known material such as a nonwoven fabric, a plastic film, a polylaminated nonwoven fabric, paper, or a composite material thereof can be used without particular limitation, but the fineness is 1.0 to 3.5 dtex, and the basis weight is 20 to 100 g / m. ^2. Spunbond nonwoven fabric, air-through nonwoven fabric, or spunlace nonwoven fabric having a thickness of 1 mm or less is preferred.

(Target sheet)
A target sheet 20 for facilitating connection is provided at a connection portion of the connection portion 13A in the ventral portion F. When the connecting portion 13A is a hook material, the target sheet 20 includes a base layer made of a plastic film or a non-woven fabric, and an engagement layer provided on the entire outer surface of the connecting portion 13A so that the hook of the connecting portion 13A is detachably engaged. A thing can be used suitably. As an engagement layer in this case, in addition to a form in which a loop is formed on the base layer by a thread sewn into the base layer, a nonwoven fabric layer of a thermoplastic resin is attached on the base layer by intermittent ultrasonic sealing, Although the form in which the fibers of the nonwoven fabric form a loop is known, any of them can be suitably used. Moreover, the target sheet 20 of the type which gave the embossing to the nonwoven fabric of the thermoplastic resin, and does not have a base layer can also be used. In these target sheets 20, the connecting portion 13 </ b> A is connected to the target sheet 20 by the hook of the connecting portion 13 </ b> A being entangled or caught in the loop. Moreover, when 13 A of connection parts are adhesive material layers, what performed the peeling process to the surface of the plastic film which has a smooth and rich surface as the target sheet 20 can be used suitably.

<Explanation of terms in the specification>
The following terms in the specification have the following meanings unless otherwise specified in the specification.
-“Deployed state” means a state in which a natural length is extended and completely flattened without contraction or sagging.
・ "MD direction" and "CD direction" mean the flow direction (MD direction) in production equipment and the transverse direction (CD direction) orthogonal to this, and in tape-type disposable diapers, the MD direction is the longitudinal direction of the product. The CD direction is the product width direction.
“Elongation rate” means a value when the natural length is 100%.
-"Gel strength" is measured as follows. Add 1.0 g of superabsorbent polymer to 49.0 g of artificial urine and stir with a stirrer. The produced gel is left in a constant temperature and humidity chamber of 40 ° C. × 60% RH for 3 hours and then returned to room temperature, and the gel strength is measured with a card meter (Curdmeter-MAX ME-500, manufactured by I.techno Engineering).
"Artificial urine" is urea: 2 wt%, sodium chloride: 0.8 wt%, calcium chloride dihydrate: 0.03 wt%, magnesium sulfate heptahydrate: 0.08 wt%, and ion-exchanged water: 97 0.09 wt% mixed, and used at a temperature of 37 degrees unless otherwise specified.
・ "Weight" is measured as follows. After the sample or test piece has been pre-dried, it is left in a test room or apparatus in a standard state (test location is temperature 23 ± 1 ° C., relative humidity 50 ± 2%) to obtain a constant weight. Pre-drying refers to making a sample or test piece constant in an environment at a temperature of 100 ° C. In addition, it is not necessary to perform preliminary drying about the fiber whose official moisture content is 0.0%. From the test piece in a constant weight state, a sample plate (100 mm × 100 mm) is used to cut a sample having a size of 100 mm × 100 mm. The weight of the sample was measured, 10 0 times to calculate the weight per square meter, a basis weight.
-"Water absorption" is measured by JIS K7223-1996 "Test method for water absorption of superabsorbent resin".
・ "Water absorption rate" is "Time to end point" when JIS K7224-1996 "Water absorption rate test method for superabsorbent resin" is performed using 2 g of superabsorbent polymer and 50 g of physiological saline. And
・ If there is no description about the environmental conditions in the test and measurement, the test and measurement shall be performed in a standard laboratory (test location: temperature 23 ± 1 ° C, relative humidity 50 ± 2%) in a test room or equipment. To do.
-Unless otherwise specified, the dimensions of each part mean dimensions in a deployed state, not a natural length state.

  The present invention can be applied to absorbent articles in general such as sanitary napkins as well as pants-type or pad-type disposable diapers as well as tape-type disposable diapers as in the above examples.

  B: Dorsal side part, C: Center in the front-rear direction, CP: Intermediate part, EF: End flap part, F ... Abdomen side part, LD ... Front-back direction, SF ... Side flap part, WD ... Width direction, WP ... Wing part, DESCRIPTION OF SYMBOLS 10 ... Main body, 11 ... Liquid impervious sheet, 12 ... Exterior sheet, 13 ... Fastener assembly, 13A ... Connection part, 13B ... Fastener fixing part, 13C ... Support piece, 13F ... Fastener free part, 20 ... Target sheet, 30 ... top sheet, 40 ... upper absorbent element, 50 ... lower absorbent element, 40, 50 ... absorbent element, 56 ... absorbent body, 58 ... packaging sheet, 60 ... rising gather, 62 ... gather sheet, 63 ... gather elastic member, 70 ... side elastic member, 90 ... waist elastic sheet, 95 ... intermediate elastic region, 96 ... non-elastic region, 41 ... first nonwoven fabric layer, 42 ... second nonwoven fabric layer, 43 ... high absorbency Rimmer particles, 80 ... junction, 81 ... non-joined section, 44 ... hot-melt adhesive, 45 ... folded portion, 46 ... non-folded-back portion.