JP2009034271A - Disposable diaper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the permeability of watery feces, etc. to prevent their dispersion over the top sheet and reduce the soil on the skin with them. <P>SOLUTION: The disposable diaper is provided with an intermediate sheet 40 between a top sheet 30 and an absorbent element 50 in contact with the back of the top sheet 30. The top sheet 30 has permeable pores H perforated at a fixed interval. The intermediate sheet 40 keeps an elastic member 42 stretched and fixed over the base sheet 41 in an extended state with the base sheet 41 shrunk by the shrinkage of the elastic member 42 to form wavelike wrinkles. These wavelike wrinkles are located at least in part behind the permeable pores H of the top sheet 30. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a disposable diaper.

In general, the stool of an infant changes from watery stool to soft stool in about three months after birth, and solidifies at the beginning of the baby food. For this reason, in disposable diapers for babies, various techniques have been proposed in consideration of absorption of watery stool and soft stool (hereinafter also referred to as watery stool) (see, for example, Patent Documents 1 and 2). Among these, it has been found that the technique of perforating permeation holes in the liquid-permeable top sheet forming the body-side surface is effective for absorbing watery stool and the like.
Japanese Patent Laying-Open No. 2005-246811 Japanese Patent No. 2812340

However, in conventional disposable diapers, there is no gap on the back side of the top sheet, so watery stools etc. are difficult to permeate, and the watery stool etc. spreads on the top sheet surface, causing the skin to become dirty over a wide area. Had. In particular, in a conventional disposable diaper having a transmission hole in the top sheet, since there is no gap on the back surface side of the transmission hole, the function of the transmission hole has not been fully utilized.
Therefore, the main problem of the present invention is to improve the permeability of watery stool, etc., thereby preventing the diffusion of watery stool and the like on the surface of the top sheet, and reducing the dirt on the skin.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
An absorbent element is interposed between the liquid-permeable top sheet forming the body-side surface and the liquid-impermeable sheet located on the outer surface side, and the crotch is formed from the upper edge of the ventral side along the center in the width direction. In a disposable diaper having an absorbent main body extending to the upper edge of the street back side,
An intermediate sheet in contact with the back surface of the top sheet is provided between the top sheet and the absorbent element,
This intermediate sheet is obtained by fixing the elastic member to the base sheet in a stretched state, and then shrinking the base sheet by contraction of the elastic member to form a wavy ridge on the surface.
A disposable diaper characterized by that.

(Function and effect)
In the disposable diaper, an intermediate sheet (also referred to as a second sheet) is provided between the top sheet and the absorbent element in order to move excrement that has passed through the top sheet to the absorbent body and prevent reversal. Conventionally, a bulky nonwoven fabric using thick fibers has been used as the intermediate sheet, and watery stool or the like that has permeated the top sheet has been absorbed through the wide fiber gap. However, even if the fiber gap is wide, it is close to the closed state compared to the state where there is nothing.
On the other hand, in the present invention, a wavy ridge is formed on the surface of the intermediate sheet, and a linearly continuous space is formed between the recess of the ridge and the top sheet. Therefore, the watery stool or the like that has passed through the top sheet is accepted and spreads in this space, so that the permeation allowance of the watery stool or the like is increased as compared with the conventional case. As a result, watery stool or the like hardly spreads on the surface of the top sheet, and skin dirt is also reduced. In addition, since the wrinkles of the intermediate sheet are formed by the contraction force of the elastic member, even if the wrinkles are temporarily extended by external pressure, when the external pressure is released, it is forcibly restored to the original state, The above-mentioned space is ensured between them. Therefore, the above-mentioned permeability improvement effect is exhibited continuously and reliably.

<Invention of Claim 2>
An absorbent element is interposed between the liquid-permeable top sheet forming the body-side surface and the liquid-impermeable sheet located on the outer surface side, and the crotch is formed from the upper edge of the ventral side along the center in the width direction. In a disposable diaper having an absorbent main body extending to the upper edge of the street back side,
The top sheet has transmission holes drilled at a predetermined interval,
An intermediate sheet in contact with the back surface of the top sheet is provided between the top sheet and the absorbent element,
The intermediate sheet is obtained by fixing the elastic member to the base sheet in a stretched state, and then contracting the base sheet by contraction of the elastic member to form a wavy ridge on the surface, and at least a part of the ridge Is located on the back side of the transmission hole of the top sheet,
A disposable diaper characterized by that.

(Function and effect)
The invention described in this section adopts the intermediate sheet of the present invention on the premise that the top sheet has a transmission hole. Water-like stool that has permeated through the perforation hole of the top sheet is accepted and spreads in a linearly continuous space between the concave portion of the heel and the top sheet, so that the permeation function of the permeation hole is fully exhibited. Become. Needless to say, the transmission hole of the present invention is a hole penetrating the front and back of the top sheet, and is not a hollow hole.

<Invention of Claim 3>
The intermediate sheet is a laminate of two nonwoven fabrics having a fineness of 2.0 to 5.0 dtex, a fiber basis weight of 10 to 30 g / m ² and a thickness of 0.1 to 4.0 mm, and a thickness of 150 to 1240 dtex between these nonwoven fabrics. In a stretched state of 100 to 300%, a plurality of elongated elastic members of the above are fixed in parallel with an interval of 3 to 15 mm, and then the nonwoven fabric is contracted by contraction of the elastic members so that the surface crosses the elastic members. The disposable diaper of Claim 1 or 2 which formed the corrugated bag which follows.

(Function and effect)
By using the intermediate sheet having such a structure, the effect of the present invention is further enhanced. Further, by using such a nonwoven fabric as a base material, solid content such as watery stool is filtered by the fiber gap of the nonwoven fabric itself, and only the liquid component reaches and is absorbed by the absorbent element. Absorption performance is not impaired.

<Invention of Claim 4>
The disposable diaper according to claim 3, wherein the bag is formed along a diaper width direction.

(Function and effect)
When the direction of the heel is the diaper width direction, watery stool or the like is difficult to diffuse in the front-rear direction, and contamination by stool such as a urinary organ can be effectively prevented.

  As described above, according to the present invention, the permeability of watery stool or the like is improved, so that the diffusion of watery stool or the like on the surface of the top sheet is prevented, and the skin dirt is reduced.

As disposable diapers for infants of watery stools and soft stools, so-called tape diapers are widely used, so in the following, examples of tape diapers will be drawn and explained. Needless to say, the present invention is applicable to other forms of disposable diapers such as pants-type disposable diapers. The present invention is naturally applicable to adult disposable diapers.
1 and 2 show an example of a tape-type disposable diaper according to the present invention. FIG. 2 is a view taken along line B-B in FIG. This tape-type disposable diaper extends from the upper edge F1 of the ventral side F through the crotch part C to the upper edge B1 of the dorsal side B along the center in the width direction. , On both sides of the upper edge F1 side portion of the ventral side F, a pair of abdominal side flap portions FF, FF extending to the outside in the width direction from the crotch portion C, and both sides of the upper edge B1 side portion of the back side B Are provided with a pair of dorsal side flap portions BF, BF extending to the outside in the width direction from the crotch portion C. Moreover, the fastening piece 130 as a locking member is provided in the back side flap part BF and BF, respectively.
More specifically, the entire outer surface of the absorbent main body 10 and the side flap portions BF and FF on the back side and the abdomen side is formed by the exterior sheet 12. In particular, in the absorbent main body 10, a liquid-impermeable sheet 11 is fixed to the inner surface side of the exterior sheet 12 with an adhesive such as a hot-melt adhesive, and an absorbent element is further disposed on the inner surface side of the liquid-impermeable sheet 11. 50, the intermediate sheet 40, and the top sheet 30 are laminated in this order. In the illustrated example, the top sheet 30 and the liquid-impermeable sheet 11 are rectangles extending from the ventral upper edge F1 to the back upper edge B1, and have slightly larger dimensions in the front-rear direction and the width direction than the absorbent element 50. The liquid-impermeable sheet 11 is formed to be slightly wider than the top sheet 30. The peripheral edge that protrudes from the side edge of the absorbent element 50 in the top sheet 30 and the peripheral edge that protrudes from the side edge of the absorbent element 50 in the liquid-impermeable sheet 11 are fixed by a hot melt adhesive or the like. The top sheet 30 is fixed to the intermediate sheet 40 and / or the absorbent element 50.
Further, barrier cuffs 60, 60 projecting (standing) toward the wearer's skin are provided on both sides of the absorbent main body 10, and barrier sheets 64, 64 forming the barrier cuffs 60, 60 are provided. In addition, the inner side of each of the side flap portions BF and FF on the back side and the ventral side is extended over the entire widthwise outer side of the absorbent main body portion 10.

Hereinafter, the material and characteristic parts of each part will be described in order (exterior sheet).
The exterior sheet 12 is a part that supports the absorbent element 50 and is attached to the wearer. The exterior sheet 12 has an hourglass shape in which the center part in the front-rear direction on both sides is constricted, and this is a part into which the wearer's leg is placed.
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 as the material fiber, for example, synthetic fibers such as polyethylene or polypropylene, synthetic fibers such as polyester or polyamide, recycled fibers such as rayon or cupra, and natural fibers such as cotton are used. 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, laminated nonwoven fabrics such as SMS nonwoven fabrics and SMMS nonwoven fabrics are preferred 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.

(Top sheet)
The top sheet 30 is sufficient as long as it has liquid permeability, but a nonwoven fabric is preferably used from the viewpoint of touch and the like. The nonwoven fabric used for the top sheet 30 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. In particular, an air-through nonwoven fabric, a spunbonded nonwoven fabric, a pointbonded nonwoven fabric, or an SMS nonwoven fabric having a fineness of raw material fibers of 1.0 to 3.0 dtex and a fiber basis weight of 10 to 30 g / m ² are suitable.
The top sheet 30 may be composed of a single sheet or 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.

(Top sheet transmission hole)
A transmission hole H is formed in the top sheet 30. The arrangement, shape, and structure of the through holes H are not particularly limited, and known forms can be adopted, but the following forms are particularly suitable. That is, when the top sheet 30 is based on the crack on the back side and the correspondence with the top of the buttocks, the width direction central region 31 that extends from the front end F1 to the rear end B1 through the portion corresponding to the crack, A left intermediate region 32 and a right intermediate region 32 that are located on the left side and the right side of the central region 31 in the width direction and extend from the front end F1 to the rear end B1 through the portions corresponding to the top of the left ridge and the top of the right ridge, respectively. 32 and left and right regions 33 and 33 extending from the front end F1 to the rear end B1 along the left side of the left intermediate region 32 and the right side of the right intermediate region 32, respectively. Further, in the illustrated embodiment, side edge regions 34 and 34 including portions for joining and fixing the top sheet 30 to the liquid-impermeable sheet 11 are provided on the left side of the left side region and on the right side of the right side region. The right region 33 is a region located on the absorbent element 50.
Specifically, in the baby diaper, the width of the central region 31 in the width direction is about 20 to 40 mm, the width of the left intermediate region and the right intermediate region 32 is about 15 to 25 mm, and the width of the left region and the right region 33 is 10 to 10 mm. It is appropriate to set it to about 20 mm.
And characteristically, as shown also in FIG. 3, the solid content such as watery stool is permeated to the back side in each of the width direction central region 31, the left side and the right side region 33 in the top sheet 30. A large number of permeation holes H are perforated at a predetermined interval, and the permeation holes H are not perforated in the left and right intermediate regions 32 and 32 as a whole. Accordingly, the width direction central region 31, the left side and the right side are arranged so that the width direction arrangement of the perforated range and the non-perforated range of the transmission holes H is applied to at least the crack, the top portion of the heel portion, and the portion corresponding to the outer side in the width direction. The range of the area 33 is determined. In addition, if the crack, the top of the buttock, and the portion corresponding to the outer side in the width direction are included, only a part of each region 31 to 33 in the front-rear direction has such a width direction arrangement of the piercing range and the non-piercing range. For example, it is also possible to adopt such a pattern only on the back side B.
Further, when the width of the left and right regions 33, 33 is narrower than the width of the central region 31 in the width direction, when the wearer lies down sideways, the buttock is returned from the transmission hole H of the left or right region 33 that contacts the buttock. This is preferable because the amount of excrement adhering to the water is small.
The opening shape of the transmission hole H can be an appropriate shape such as a circle, an ellipse, an oval, a leaflet shape, a polygon, etc., but the length HL in the front-rear direction is 4 to 15 mm, particularly 6 to 8 mm. It is preferable that the width direction length HW is an elongated shape (elliptical shape, oval shape, leaf shape) shorter than the length HL in the front-rear direction.
Although the opening area of the transmission hole H may be appropriately determined, it is preferable to be 0.8～180Mm ^2, particularly preferably in a 5～80Mm ^2, and most preferable to be 10 to 30 mm ^2. If the opening area is too small, the solid content taking-in performance is lowered, and if it is too large, it is easy to return through the permeation hole H.
The number of transmission holes H can be determined as appropriate. As shown in the figure, the arrangement of the transmission holes H is such that the transmission hole arrays in which the transmission holes H are arranged at predetermined intervals in the front-rear direction are provided at predetermined intervals in the width direction. In the case of the above-described arrangement and the opening area of the transmission holes H described above, the width-direction interval DW between the columns of the transmission holes H is 1 to 5 mm, and the interval DL between the transmission holes H in the column is 1 to 1 It is preferable to determine the number and arrangement in each of the regions 31 to 33 so as to be 10 mm. If the interval between the permeation holes H is too wide, the solid content is easily captured without being captured, and if it is too narrow, the number of the permeation holes becomes too large and reversal is likely to occur through the permeation holes H. The arrangement of the through holes H can be a staggered arrangement (illustrated example) or a lattice (matrix) arrangement, and other regular or irregular arrangements can be adopted.
The transmission hole H may be the same shape, the same size, and the same arrangement interval as those formed in the width direction central region 31 and those formed in the left and right regions 33 and 33, but different from each other. You can also. As one preferred form, as shown in FIG. 4, the width direction length HW1 of the opening of the transmission hole H formed in the width direction central region 31 is 4 to 10 mm, and is formed in the left and right regions 33 and 33. It is proposed that the width direction length HW2 of the opening of the transmission hole H is shorter than that of the central region 31 in the width direction and is 2 to 7 mm. Thus, if the width direction length HW1 of the opening of the transmission hole H formed in the left and right regions 33, 33 is shorter than that in the center region in the width direction, the transmission that contacts the buttocks when the wearer lies down sideways. Since the total area of the holes is small, there is an advantage that the amount of excrement returning from the permeation holes H and adhering to the buttocks is small.
Moreover, as another preferable form, as shown in FIG. 5, the opening area of the transmission hole H formed in the width direction center region 31 is 5 to 40 mm ² and formed in the left and right regions 33 and 33. One having an opening area of the transmission hole H larger than that of the central region 31 in the width direction and 10 to 50 mm ² is proposed. Thereby, the stool having a high solid content ratio that has reached the left and right regions 33 and 33 can be captured effectively.

(Fixing the top sheet)
The top sheet 30 is desirably fixed to the member on the back surface in the non-perforated range. In particular, in order to form a wide space for capturing stool, it is preferable that the top sheet 30 is not fixed to the member on the back surface at least in the center in the width direction of the perforated region. The top sheet 30 can be fixed by ultrasonic welding, heat sealing, heat embossing, or the like, or by bonding with an adhesive such as a hot melt adhesive, but it is preferable that the adhesive is exposed from the through holes H. Therefore, it is preferable to weld the top sheet 30 to the member on the back surface side within a range of ± 10 mm in the width direction, particularly within ± 5 mm with reference to both side edges in the width direction of each transmission hole group.

(Top sheet punching method)
The top sheet 30 having the permeation holes H is formed by punching the perforation hole forming portion into a predetermined shape, perforating while being melted by a heat roller provided with a plurality of protrusions (special table 2002-512909), negative pressure A method of perforating while forming a three-dimensional taper by suction stretching heat treatment with an open conveyor (Patent No. 2812340), or forming a slit along a predetermined direction (front-rear direction, width direction, etc.) at a transmission hole forming position Later, the sheet is stretched in a direction perpendicular to the slit, and manufactured by a method (Japanese Patent Laid-Open No. 11-253490) for fixing to the member on the back side (intermediate sheet 40 and / or absorbent element 50) in a state where the slit is expanded. Can do. Each of these methods has advantages, but has the following disadvantages. That is, the punching method generates waste material, the melt drilling method hardens the periphery of the opening, and the method of forming a three-dimensional taper is a method in which the opening is easily crushed when pressure in the thickness direction is applied, and the film is stretched after the slit. Then, when the diaper is bent, the extension of the opening is relaxed and it becomes easy to close. In the present invention, after forming a slit along the front-rear direction at the transmission hole forming position, the sheet is stretched in the width direction, and the method of adhering to the member on the back surface side in the expanded state is combined as follows. It is most preferable, and this makes it possible to exhibit excellent performance while eliminating the above disadvantages.
After forming a slit along the front-rear direction at the transmission hole formation position, the sheet is stretched in the width direction, and the slit is expanded to form an opening. And the fiber spacing is widened, so that it is soft and excellent in liquid permeability. However, as described above, in order to secure a wide space for holding stool on the back side of the top sheet 30, if the top sheet 30 and the back side member are not fixed at almost the entire width, the opening of the diaper is bent and the opening is stretched. It relaxes and becomes easier to close. On the contrary, if it adheres to almost the entire surface of the sheet, a space for holding feces cannot be formed on the back side of the top sheet 30. Therefore, it is preferable to take a form of fixing at a constant interval in the width direction. In the present invention, since the left and right intermediate areas are provided as non-perforated areas instead of providing the perforated areas almost at the full width of the sheet, it is possible not only to prevent adherence of excrement to the buttocks due to reversing, By fixing the top sheet 30 and the member on the back side using the intermediate region (and both sides of the top sheet 30), the top sheet 30 can be firmly fixed while maintaining the opening state of the transmission holes H. It becomes possible. In this case, it is preferable to fix the area in the vicinity of both side edges in the width direction of each transmission hole group of the top sheet 30 because the open state of the transmission holes H can be stably maintained. It is preferable to use welding for fixing the substrate.

(Barrier cuffs)
In order to prevent urine and soft stool that move laterally on the top sheet 30 and prevent side leakage, barrier cuffs 60, 60 that protrude (stand up) on the use surface side are provided on both sides of the product. preferable.
The barrier cuff 60 includes a barrier sheet 64 that is substantially continuous in the width direction, and an elongated elastic elastic member 62 that is fixed to the barrier sheet 64 in a stretched state along the front-rear direction. As the barrier sheet 64, a water-repellent nonwoven fabric can be used, and as the elastic elastic member 62, thread rubber or the like can be used. As shown in FIGS. 1 and 2, a plurality of elastic elastic members 62 can be provided in addition to the plurality.
The inner surface of the barrier sheet 64 has a fixing start end in the width direction on the side portion of the top sheet 30, and a portion on the outer side in the width direction from the fixing start end is on the side portion of the liquid-impermeable sheet 11 and on the outer side in the width direction. It fixes to the side part of the exterior sheet | seat 12 located with the hot-melt-adhesive agent etc. An elastic elastic member 66 such as a rubber thread is provided along the front-rear direction between the sheets of the portion where the barrier sheet 64 and the exterior sheet 12 face each other in the vicinity of the fixing start end of the fixing portion.
Around the legs, the inner side in the width direction from the sticking start end of the barrier cuff 60 is fixed on the top sheet 30 at both ends in the product front-rear direction, but the portion between them is an unfixed free portion, and this free portion is It comes to stand by the contraction force of the rubber thread 62. When the diaper is worn, the diaper is worn on the body in the shape of a boat, and the contraction force of the rubber thread 62 acts on the diaper, so that the barrier cuff 60 stands up and comes into close contact with the legs around the contraction force of the rubber thread 62. As a result, so-called side leakage from around the legs is prevented.

(Absorption element)
The absorption element 50 is a part that absorbs and holds liquid such as urine and loose stool. The absorbent element 50 includes an absorbent body 56 and a covering sheet 58 that wraps at least the back and side surfaces of the absorbent body 56. The covering sheet 58 can be omitted. Further, in the illustrated embodiment, the holding sheet 80 is provided between the absorber 56 and the back surface side portion (lower part) of the covering sheet 58, but the holding sheet 80 may be omitted. The 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 by an aggregate of the fibers 52 and 52. 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 crimped degree of the crimped fiber can be, for example, 5 to 75, preferably 10 to 50, and more preferably about 15 to 50 per inch. Further, a crimped fiber that is uniformly crimped is often used.

(Superabsorbent polymer particles)
As shown in FIG. 2, the absorbent body 56 preferably includes superabsorbent polymer particles 54, 54..., In particular, at least in the liquid receiving region, the superabsorbent polymer particles with respect to the aggregate of fibers 52, 52. It is desirable that (SAP particles) be dispersed substantially throughout the thickness direction.
If there is no SAP particle in the upper part, the lower part, and the middle part of the absorber 56, or if there is very little, it cannot be said that the "absorbed throughout the thickness direction". Therefore, “distributed in the entire thickness direction” means “distributed unevenly in the upper part, the lower part, and / or the middle part of the aggregate of fibers in addition to the form“ uniformly ”distributed in the entire thickness direction. However, it is still included in the form of being dispersed in the upper, lower and middle portions. In addition, a form in which some SAP particles do not penetrate into the aggregates of the fibers 52, 52... Remain on the surface, and some SAP particles pass through the aggregates of the fibers 52, 52. The form on the sheet 58 and the form on the holding sheet 80 are not excluded.
The superabsorbent polymer particles 54 include “powder” in addition to “particles”. As the particle diameter of the superabsorbent polymer particles 54, those used for this type of absorbent article can be used as they are, and those having a particle size of 1000 μm or less, particularly 150 to 400 μm are desirable. The material of the superabsorbent polymer particles 54 can be used without any particular limitation, but those having a water absorption of 40 g / g or more are suitable. Examples of the superabsorbent polymer particles 54 include starch-based, cellulose-based and synthetic polymer-based polymers, such as starch-acrylic acid (salt) graft copolymer, saponified starch-acrylonitrile copolymer, and sodium carboxymethylcellulose. A cross-linked product or an acrylic acid (salt) polymer can be used. The shape of the superabsorbent polymer particles 54 is preferably a granular material that is usually used, but other shapes can also be used.
As the superabsorbent polymer particles 54, those having a water absorption speed of 40 seconds or less are preferably used. When the water absorption speed exceeds 40 seconds, so-called reversion in which the liquid supplied into the absorber 56 returns to the outside of the absorber 56 is likely to occur.
The basis weight of the superabsorbent polymer particles 54 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 set to 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. If it exceeds 350 g / m ² , not only will the effect be saturated, but an excessively high superabsorbent polymer particle 54 will give a sense of incongruity.

(Enveloping sheet)
When the covering 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 SMMS (spunbond / meltblown / meltblown / spunbond) nonwoven fabric is particularly suitable, and polypropylene, polyethylene / polypropylene, etc. can be used as the material. The basis weight is preferably 5 to 40 g / m ² , particularly 10 to 30 g / m ² .
As shown in FIG. 2, the covering sheet 58 wraps only the back and side surfaces of the continuous fiber 52, 52... And the superabsorbent polymer particles 54, 54. It may be covered. Although not shown, only the upper and side surfaces of the absorbent body 56 are covered with crepe paper or a nonwoven fabric, and the lower surface is covered with a liquid-impermeable sheet such as polyethylene, and the upper surface of the absorbent body 56 is covered with crepe paper or a nonwoven fabric. For example, the lower surface may be covered with a liquid-impermeable sheet such as polyethylene (each of these materials becomes a component of the covering sheet). If necessary, the aggregate of continuous fibers 52, 52... And the layer of superabsorbent polymer particles 54, 54... May be sandwiched between two upper and lower sheets or disposed only on the lower surface. This is not a desirable form because it is difficult to prevent the movement of particles.

(Holding sheet)
When a filament aggregate is used for the fiber 52, it is preferable to provide a holding sheet 80. In the case where the holding sheet 80 is provided, the superabsorbent polymer particles 54 can be interposed between the holding sheet 80 and the absorbent body 56 by spraying or the like. The superabsorbent polymer particles 54 may pass through the filament aggregate at the time of supply to the filament aggregate or in the subsequent process or until the consumer uses it. The unevenness of the superabsorbent polymer particles that have passed through the filament aggregate gives a crisp and uncomfortable feeling when touched by a hand when used by a consumer.
The holding sheet 80 reinforces the stiffness that is not sufficient only by the covering sheet 58 such as tissue paper (crepe paper), and also reduces or prevents a sense of incongruity when touched by the hand when the consumer uses it. Fulfill.
The material of the holding sheet 80 is not particularly limited as long as it has a holding performance of the superabsorbent polymer 54. Specifically, for example, non-woven fabric, crimped pulp, low-absorbency cotton fiber (for example, non-degreased cotton fiber, degreased cotton fiber, rayon fiber treated with a water repellent or a hydrophobizing agent, etc.). ), Polyethylene fiber, polyester fiber, acrylic fiber, polypropylene fiber, silk, cotton, hemp, nylon, polyurethane, acetate fiber and the like.
The holding sheet 80 preferably has a thickness larger than the particle diameter of the superabsorbent polymer particles. The basis weight of the holding sheet 80 is 10 to 60 g / m ^2, it is preferred in particular 20 to 40 g / m ^2.
In particular, the holding sheet 80, the compression energy 0.01~10.00gfcm / cm ² based on KES test, preferably at 0.01~1.00gfcm / cm ^2, and the compression resilience from 10 to 100%, preferably Is preferably 70 to 100% non-woven fabric.
Further, since the superabsorbent polymer 54 that has slipped out is held by the holding sheet 60 and does not move on the covering sheet 58, uneven distribution of the absorption capacity is less likely to occur. In particular, in order to prevent the superabsorbent polymer particles 54 from moving on the holding sheet 80, an adhesive hot melt adhesive or the like can be applied on the holding sheet 80 in advance. Alternatively, the upper surface of the holding sheet 80 (surface toward the use surface side) may be a rough surface to prevent the superabsorbent polymer particles 54 from moving on the holding sheet 80. Examples of the roughening or fluffing means for this purpose include a non-net surface that is not a net surface during the production of the nonwoven fabric, a marble process, a needle punch process, and a brushing process.
As shown in FIG. 2, the holding sheet 80 may be provided only below the absorber 56, or may be wound up and extended to the upper surface of the absorber 56 through the side surface of the absorber 56, although not shown. It is also possible to use a plurality of holding sheets 80 in a stacked manner.
The above example is an example in which the holding sheet 58 is provided between the absorber 56 and the back side portion of the covering sheet 58, but the holding sheet may be on the back side from the covering sheet 58 (its form is In short, if a holding sheet is provided on the back surface side with respect to the absorber 56, the point is that the sensation of discomfort when touched from the back surface of the product is reduced or not caused.

(Fastening piece)
The fastening piece 130 has a base portion of a fastening base material 130C made of plastic, polylaminated nonwoven fabric, paper, or the like joined to a diaper, and a hook element 130A of a mechanical fastener is provided as a locking portion for the ventral side at the tip side portion. ing. The hook element 130A is bonded to the fastening substrate 130C by an adhesive so as not to be peeled off. The hook element 130A has a large number of engaging protrusions on the outer surface side thereof. The shape of the engaging protrusion is (A) Le-shaped, (B) J-shaped, (C) Mushroom-shaped, (D) T-shaped, (E) Double J-shaped (J-shaped And the like may be any shape. Instead of the hook element 130 </ b> A, an adhesive layer can be provided as a locking portion of the fastening piece 130.
When the diaper is worn, the fastening piece is locked at a proper position on the outer surface of the abdominal side F with the back side flap portion BF overlapped on the outside of the abdominal side flap portion FF. The position and size of the fastening portion of the fastening piece 130 can be arbitrarily determined. In a normal case, the locking portion is a rectangular range having a height of 20 to 80 mm and a width of 150 to 300 mm, and a distance in the height direction between the upper end edge and the ventral upper edge F1 is 0 to 60 mm, particularly 20 to 50 mm. And it is preferable to set it as the center of the width direction of a product.
It is preferable to provide a target tape 74 at the locking position of the fastening piece 130 on the ventral side F in order to facilitate locking. As the target tape 74, when the hook portion is the hook element 130A, a tape having a large number of loop yarns on which the engaging projections of the hook element are entangled can be used. A film having a smooth surface that is rich in properties can be used.
Further, when the fastening portion of the fastening piece 130 on the ventral side F is made of a nonwoven fabric, for example, when the exterior sheet 12 of the illustrated form is made of a nonwoven fabric, and the fastening portion of the fastening piece 130 is the hook element 130A, The target tape 74 can be omitted, and the hook element 130A can be entangled with the nonwoven fabric of the exterior sheet 12 and locked.

(Intermediate sheet)
The intermediate sheet 40 is interposed between the top sheet 30 and the absorbent element 50 so as to be in contact with the back surface of the top sheet 30, and is attached to the base sheet 41, 41 as shown in FIGS. 6 and 7. After the elastic member 42 is fixed in a stretched state with a hot melt adhesive or the like, the elastic member 42 is contracted to form a wavy ridge on the surface.
In the illustrated embodiment, the two base sheets 41 and 41 are bonded together with a hot melt adhesive or the like, and the elastic member 42 is sandwiched between them. The elastic member 42 can also be fixed to the surface.
As the base material sheet 41, various non-woven fabrics similar to the top sheet 30 can be used, but an air-through non-woven fabric that is particularly bulky and excellent in liquid permeability is preferable. In addition, it is preferable to use the nonwoven fabric with high smoothness for the base material sheet 41 so that adhesiveness with the elastic member 42 may become favorable. In the case of an air-through nonwoven fabric, it has a fluffed surface (air surface) and a smooth surface. However, if the smooth surface is used as an adhesive surface with the elastic member 42, reliable bonding is possible. Moreover, even if it compacts with a press roll etc. and smoothes a fluff surface, reliable adhesion is possible similarly. In the present invention, the base sheet 41 and the elastic member 42 are combined to form a wavy ridge, so that a substantially bulky intermediate sheet 40 can be obtained or the bulk of the intermediate sheet 40 can be freely adjusted. . Even if the liquid permeability of the base sheet 41 itself is not necessarily excellent, a wide space can be formed between the base sheet 41 and the top sheet 30, so that permeation allowance for watery stool and the like increases. Accordingly, an SMS nonwoven fabric or a melt blown nonwoven fabric having a low liquid permeability, such as a spunbond nonwoven fabric or a point bond nonwoven fabric that is not bulky in nature, can be suitably used for the base material sheet 41. Since these non-woven fabrics are produced by compaction with a hot embossing roll, both the front and back surfaces are smooth and excellent in adhesiveness, and either surface may be used as an adhesive surface with the elastic member 42, or wavy corrugations Is preferable in that it can be formed satisfactorily. Furthermore, when the intermediate sheet 40 and the top sheet 30 are bonded using heat embossing or ultrasonic welding, the material of the intermediate sheet 40 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 40 is 1.0 to 2.0 dtex, the liquid residue of the top sheet 30 hardly occurs, but the solid content of the stool is difficult to permeate. Therefore, it is preferable that the fiber of the nonwoven fabric used for the intermediate sheet 40 has a fineness of about 2.0 to 5.0 dtex.
As the elastic member 42, a net-like or sheet-like one can also be used, but an elongated one such as a thread, string or belt is preferred because the liquid permeability is less lowered.
When the base sheet 41, 41 made of a nonwoven fabric is bonded together and the intermediate sheet 40 is formed by sandwiching an elongated elastic member between the sheets 41, 41, each nonwoven fabric has a fineness of 2.0 to 5.0 dtex. (Especially 3.0 to 4.0 dtex), fiber basis weight 10 to 30 g / m ² , (especially 15 to 20 g / m ² ), thickness 0.1 to 4.0 mm (especially 0.5 to 2.0 mm) Synthetic rubber with a thickness of 150 to 1240 dtex (especially 450 to 600 dtex) is used as the elastic member 42, and the elastic member 42 is stretched by 100 to 300% (especially 150 to 200%) and 3 to 15 mm (especially After fixing a plurality of parallel gaps with a spacing Z of 5 to 10 mm), it is preferable that the elastic member 42 is contracted to form a wavy ridge along the direction intersecting the elastic member 42 on the surface. In such an intermediate sheet 40, long and regular wrinkles are formed, and the space formed between the top sheet 30 continues for a longer distance.
The depth Y of the ridge is preferably about 1 to 5 mm, and the distance X between the vertices of the ridge is preferably about 1 to 10 mm. Such wrinkles can be formed by appropriately adjusting the material and thickness of the base sheet 41 and the stretch rate of the elastic member 42.
The direction of the heel (direction perpendicular to the extending direction of the elastic member) can be determined as appropriate, and the heel may be formed along the diaper front-rear direction, but the heel is formed along the diaper width direction. Water-like stools and the like are difficult to diffuse in the front-rear direction, and contamination by stool such as urinary organs can be effectively prevented.
The intermediate sheet 40 does not have to have all of the surface wrinkles located on the back side of the transmission hole H of the top sheet 30, and at least a part thereof is located on the back side of the transmission hole H of the top sheet 30. good. Although the arrangement | positioning of the part which has the ridge of the intermediate | middle sheet | seat 40 can be determined suitably, it is preferable that it is provided so that the part facing an anus may be included. Specifically, in the case of diapers for infants, the front-rear direction range from the position of 50 mm forward to the position of 160 mm rearward with respect to the center of the diaper front-rear direction, and the right side from the position of 50 mm to the left with respect to the center of the diaper width direction It is preferable that a portion having a ridge of the intermediate sheet 40 is provided so as to include a range in the width direction up to a position of 50 mm.
The part having the ridges may be a part or the whole of the intermediate sheet 40. The wrinkle formation range in the intermediate sheet 40 is appropriately changed by changing the range in which the elastic member 42 is fixed in the stretched state, or after being fixed over the entire length of the base sheet 41 in the stretched state by any method. It can be changed by preventing the non-wrinkle forming portion of the portion having the member 42 from elastically expanding and contracting. In particular, when a portion having no wrinkles is provided in a part of the intermediate sheet 40 and portions having wrinkles are disposed before and after the intermediate sheet 40, the cutting method described in JP-A-2002-035029 or JP-A-2002-178428 is used for elasticity. The member 42 may be cut finely so that a part of the intermediate sheet 40 does not have wrinkles. In order to facilitate the manufacture of the intermediate sheet 40 itself and the fixing of the manufactured intermediate sheet 40, no wrinkles are formed at both ends (front and rear ends in the illustrated embodiment) of the elastic member 42 in the extension direction of the intermediate sheet 40. Is preferred.
In the form shown in FIG. 1, the intermediate sheet 40 is arranged in the center shorter than the width of the absorbent element 50, and the intermediate sheet 40 does not extend to the back surface of the transmission hole group in the left and right regions 33. For example, you may provide over the full width so that the back surface of these permeation hole groups may be covered. Further, the length of the intermediate sheet 40 in the front-rear direction of the diaper is preferably the same as the overall length of the diaper as shown in FIG. 1 because it is easy to manufacture, but may be the same as the length of the absorbent element 50. As shown, it may be a short length range centered on a region for receiving stool, for example, a range from the center part in the front-rear direction of the diaper to the rear end part of the absorber.
When such an intermediate sheet 40 is interposed, as described above, a linearly continuous space 43 is formed between the recesses on the surface of the intermediate sheet 40 and the top sheet 30. Accordingly, the watery stool or the like that has passed through the perforation hole H of the top sheet 30 is accepted and spreads in the space 43, and the watery stool or the like is difficult to spread on the surface of the top sheet 30 and the dirt on the skin is also reduced. . Moreover, since the wrinkles of the intermediate sheet 40 are formed by the contraction force of the elastic member 42, even if the wrinkles are temporarily extended by the external pressure, when the external pressure is released, it is forcibly restored to the original state, and the top sheet The above-described space 43 is ensured between 30 and 30.

<Others>
Although the said embodiment has the through-hole H in the top sheet 30, the intermediate sheet 40 of this invention is applicable also to the form which does not have a through-hole in the top sheet 30 (illustration omitted).

  The present invention is applied to a disposable diaper.

It is an expanded state top view of a tape type disposable diaper. It is the BB sectional view taken on the line of FIG. It is a principal part enlarged plan view of FIG. It is a principal part enlarged plan view which shows another example of a permeation hole. It is a principal part enlarged plan view which shows another example of a perforation hole. It is a top view of an intermediate sheet. It is an expanded sectional view of a top sheet and an intermediate sheet part. It is an expanded state top view of another tape type disposable diaper.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Absorbent main-body part, 11 ... Liquid impervious sheet, 12 ... Exterior sheet, 30 ... Top sheet, 31 ... Width direction center area, 32 ... Left middle area, Right middle area, 33 ... Left area, Right area, 34 ... side edge region, 40 ... intermediate sheet, 41 ... substrate sheet, 42 ... elastic member, 43 ... space, 50 ... absorbent element, 52 ... fiber, 54 ... superabsorbent polymer particles, 56 ... absorber, 58 ... an enveloping sheet, 60 ... a barrier cuff, 64 ... a barrier sheet, 80 ... a holding sheet, H ... a permeation hole.

Claims (4)

An absorbent element is interposed between the liquid-permeable top sheet forming the body-side surface and the liquid-impermeable sheet located on the outer surface side, and the crotch is formed from the upper edge of the ventral side along the center in the width direction. In a disposable diaper having an absorbent main body extending to the upper edge of the street back side,
An intermediate sheet in contact with the back surface of the top sheet is provided between the top sheet and the absorbent element,
This intermediate sheet is obtained by fixing the elastic member to the base sheet in a stretched state, and then shrinking the base sheet by contraction of the elastic member to form a wavy ridge on the surface.
A disposable diaper characterized by that. An absorbent element is interposed between the liquid-permeable top sheet forming the body-side surface and the liquid-impermeable sheet located on the outer surface side, and the crotch is formed from the upper edge of the ventral side along the center in the width direction. In a disposable diaper having an absorbent main body extending to the upper edge of the street back side,
The top sheet has transmission holes drilled at a predetermined interval,
An intermediate sheet in contact with the back surface of the top sheet is provided between the top sheet and the absorbent element,
The intermediate sheet is obtained by fixing the elastic member to the base sheet in a stretched state, and then contracting the base sheet by contraction of the elastic member to form a wavy ridge on the surface, and at least a part of the ridge Is located on the back side of the transmission hole of the top sheet,
A disposable diaper characterized by that. The intermediate sheet is a laminate of two nonwoven fabrics having a fineness of 2.0 to 5.0 dtex, a fiber basis weight of 10 to 30 g / m ² and a thickness of 0.1 to 4.0 mm, and a thickness of 150 to 1240 dtex between these nonwoven fabrics. After a plurality of elongated elastic members were fixed in parallel at an interval of 3 to 15 mm in a stretched state of 100 to 300%, the base material sheet was contracted by contraction of the elastic members and intersected with the elastic members on the surface. The disposable diaper of Claim 1 or 2 which formed the wavy bag along a direction.   The disposable diaper according to claim 3, wherein the bag is formed along a diaper width direction.

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