JP7023907B2 - Manufacturing method of absorbent articles - Google Patents

Description

The present invention relates to a method for producing an absorbent article such as a disposable diaper or a urine pad.

Conventionally, absorbent articles such as disposable diapers, urine pads and sanitary napkins have been known. The absorbent article is provided with a top sheet that is liquid permeable and comes into contact with the skin surface, and an absorber having a fiber material such as pulp or rayon and a highly absorbent polymer. Liquid water, such as urine and menstrual blood, excreted by the wearer penetrates the topsheet and is absorbed and retained by the absorber.

Various techniques have been proposed to improve the fit of absorbent articles when worn, as well as the absorption and retention performance of excrement. For example, Patent Document 1 discloses an absorbent article in which a squeezed portion (recess) formed by compressing an absorber in the thickness direction is formed. The absorbent article of Patent Document 1 is provided with two linear recesses in the longitudinal direction.

Japanese Unexamined Patent Publication No. 2014-136126

One of the purposes of this case is to manufacture an absorbent article having improved performance for maintaining the shape of the recess. Not limited to this purpose, it is also possible to exert actions and effects derived from each configuration shown in the "mode for carrying out the invention" described later, which cannot be obtained by the conventional technique. It can be positioned as another purpose.

The inventor of this case diligently examined the above-mentioned problems. As a result, in the step of obtaining the absorber, the content of each of the highly absorbent polymer and the fiber material at the position corresponding to the recess of the absorbent core is set to a value within a predetermined range, and in the step of providing the recess, the clearance between the rolls is set. It has been found that by setting the pressure applied to the laminate from the roll and the pressure within a predetermined range, the shape-maintaining performance of the recesses can be enhanced and the leakage of the highly absorbent polymer can be suppressed. Then, the method for producing the absorbent article illustrated below has been completed.
The method for producing an absorbent article disclosed herein includes a first step of coating an absorbent core containing a highly absorbent polymer and a fiber material with a wrap sheet to obtain an absorber, and the absorbent body obtained in the first step. In the second step of arranging a liquid-permeable top sheet on the surface facing the skin of the above to obtain a laminate, and passing the laminate obtained in the second step between a pair of rolls, the absorber and the said The top sheet is squeezed in the thickness direction to provide a recess on the skin-facing surface side of the laminate. In the first step, the absorbent core is provided at a position corresponding to the recess. The content of the highly absorbent polymer is 75 g / m ² or more and 300 g / m ² or less, and the content of the fiber material is 75 g / m ² or more and 250 g / m ² or less. The clearance between the rolls is 0.1 mm or more and 0.5 mm or less, and the pressure applied from the rolls to the laminate is 1.2 MPa or more and 2.0 MPa or less.

According to the present invention, it is possible to manufacture an absorbent article having improved performance for maintaining the shape of the recess.

It is a plan view development view of the paper diaper which concerns on embodiment and an Example. It is an exploded perspective view of the paper diaper of FIG. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 3 is a cross-sectional view of a recess provided in the disposable diaper of FIG. It is a plan view of a laminated body, and the measurement target defined by the retention rate measurement is shown by a thick line. It is a schematic diagram of the instrument used in the polymer leakage test. It is a flowchart which shows the manufacturing procedure (manufacturing method) of the disposable diaper which concerns on embodiment and an Example. It is a schematic diagram of a roll which forms a recess in a laminated body.

Hereinafter, a mode for carrying out this case will be described. The following embodiments are merely examples, and there is no intention of excluding the application of various modifications and techniques not specified in this embodiment. Each configuration of the present embodiment can be variously modified and implemented without departing from the gist thereof. In addition, it can be selected as needed and can be combined as appropriate.

The absorbent article described in the embodiment is a hygienic product that is attached to the wearer and absorbs and retains the water of excrement such as urine and feces excreted from the wearer (hereinafter referred to as “excreted water”). These absorbent articles include those that are worn directly to the wearer, such as tape-type and pants-type disposable diapers (so-called "disposable diapers"), as well as urine pads, menstrual napkins, and panty liners. It also includes those worn on the wearer's underwear.

In the following embodiment, in a disposable diaper as an absorbent article, the front body arranged facing the abdomen of the wearer and the rear body arranged facing the back of the wearer are placed on the extending surface of the disposable diaper. The direction of connecting with is the longitudinal direction. On the extending surface of the disposable diaper, between the front body (one side in the longitudinal direction) and the back body (the other side in the longitudinal direction) (center in the longitudinal direction), it is placed in the inseam of the wearer (opposing the crotch). The inseam is located. In addition, when the disposable diaper is worn on the wearer (hereinafter abbreviated as "wearing state"), the side facing the skin of the wearer (inside in the worn state) is defined as the skin facing surface side, and the skin facing surface side. The opposite side (outside) of the skin is the non-skin facing side. Further, the direction connecting the skin facing surface side and the skin non-facing surface side is the thickness direction, and the direction orthogonal to both the longitudinal direction and the thickness direction is the width direction. In addition, viewing from the side facing the skin in the thickness direction is defined as a plan view. The width direction in a plan view is also referred to as a left-right direction.

Regarding the orientation of each configuration in a disposable diaper, for example, when expressed along the longitudinal direction, it shall include not only parallel to the longitudinal direction but also substantially parallel to the longitudinal direction. Specifically, it is assumed that the inclination angle with respect to the longitudinal direction extends below 45 ° along the longitudinal direction. Similarly, when it is expressed along each direction such as the width direction and the thickness direction, it means that the inclination angle with respect to each direction extends at less than 45 °. In this specification, for example, the notation of the numerical range of "1 to 100" includes both the lower limit value "1" and the upper limit value "100". The same applies to the notation of other numerical ranges.

In this embodiment, a tape-type disposable diaper is exemplified as an absorbent article. The tape-type disposable diaper has a front body and a rear body separated before and after the waist circumference, unlike the pants-type disposable diaper in which the wearer's waist circumference is continuously formed in a circumferential shape. This tape-type disposable diaper is worn by various wearers such as infants and adults requiring long-term care. Hereinafter, "tape-type disposable diapers" are simply abbreviated as "diapers".

[1. Absorbent article]
[1-1. Basic configuration]
The basic configuration of the disposable diaper 100 as an absorbent article will be described with reference to FIGS. 1 to 3. In the cross-sectional view of FIG. 3, the thickness of each sheet is exaggerated in order to make it easier to understand each configuration.

As shown in FIG. 1, the disposable diaper 100 according to the present embodiment is formed symmetrically with respect to the center line A in the width direction (symmetrical with respect to the center line A). The disposable diaper 100 is roughly classified into three areas along the longitudinal direction: a front body 2, an inseam 3, and a back body 4. The front body 2 is an area located on the lower abdomen side of the wearer in the worn state. The back body 4 is an area located on the buttocks side of the wearer in the worn state. The inseam 3 is an area located between the front body 2 and the back body 4 and located in the inseam of the wearer in the wearing state.

The disposable diaper 100 has a pair of left and right front side flaps 5 extending outward in the width direction from the inseam 3 in the front body 2, and left and right extending outward in the width direction from the inseam 3 in the rear body 4. It has a pair of rear side flaps 6. Further, the disposable diaper 100 has a fastening mechanism for holding the disposable diaper 100 in a mounted state. In the present embodiment, a pair of left and right fastening tapes (hereinafter abbreviated as "tape") 60 provided so as to project outward in the width direction from each rear side flap 6 and a tape 60 provided on the front body 2 are provided. An example is a fastening mechanism composed of a patch 38 to be fastened. Instead of this, the tape 60 may be provided so as to project outward from the front side flap 5 in the width direction, and the patch 38 may be provided on the rear body 4. Further, the tape 60 may be provided in two or more pairs on the left and right.
Hereinafter, each component of the disposable diaper 100 will be described.

[Laminate]
The disposable diaper 100 includes a laminated body 10 at least in the inseam 3. The laminated body 10 of the present embodiment is provided over the front body 2, the inseam 3, and the back body 4. The laminated body 10 has a substantially rectangular shape in a plan view, and is provided in a direction in which the longitudinal direction and the width direction thereof coincide with the longitudinal direction and the width direction of the disposable diaper 100, respectively. As shown in FIGS. 2 and 3, the laminated body 10 of the present embodiment includes the absorber 20, the top sheet 31 laminated on the skin facing surface side of the absorber 20, and the skin non-facing surface side of the absorber 20. The back sheet 32 to be laminated is provided. That is, the laminated body 10 is a laminated structure in which the top sheet 31 and the back sheet 32 are arranged on both main surface sides of the absorber 20.

The laminated body 10 allows the excreted water from the skin facing surface side to permeate through the top sheet 31, absorbs and retains the permeated excreted water by the absorber 20, and leaks to the outside from the skin non-facing surface side by the back sheet 32. To prevent. The top sheet 31, the back sheet 32, and the absorber 20 can be fixed with a known adhesive such as a hot melt adhesive.

<Absorber>
The absorber 20 is a mat-shaped (or pad-shaped) member having a liquid-absorbing property that absorbs and retains excreted water. As shown in FIG. 1, in the present embodiment, an hourglass-shaped absorber 20 provided between the front body 2 and the rear body 4 is illustrated. That is, the absorber 20 has a shape in which the intermediate portion in the longitudinal direction arranged in the inseam 3 is narrowed down in the width direction with respect to both ends in the longitudinal direction arranged in the front body 2 and the rear body 4. Has been done. Further, the absorber 20 has an asymmetrical shape in which the longitudinal dimension of the portion having a large width direction on the rear body 4 side is larger than the longitudinal dimension of the portion having a large width direction dimension on the front body 2 side. It has become. However, the plan view shape of the absorber 20 is not limited to the shape as described above, and may be rectangular (that is, the dimension in the width direction is constant), or a dumbbell shape in which both ends in the longitudinal direction are circular. May be.

As shown in FIG. 3, the absorber 20 has an absorbent core 21 and a core wrap sheet (hereinafter, abbreviated as “wrap sheet”) 24. The absorber 20 is formed by wrapping the absorbent core 21 with the wrap sheet 24. That is, the absorber 20 has the absorbent core 21 built in the wrap sheet 24.

(Absorbable core)
The absorbent core 21 is a mat-shaped member that absorbs and holds a liquid. The absorbent core 21 contains a superabsorbent polymer (SAP; also referred to as a superabsorbent polymer or a superabsorbent resin) 22 and a fiber material 23. The absorbent core 21 is formed by mixing the highly absorbent polymer 22 with the fiber material 23. The fiber material 23 is formed by entwining ultrafine fibers having hydrophilicity. The highly absorbent polymer 22 is usually buried and held in the fiber material 23 by being mixed with the fiber material 23. The highly absorbent polymer 22 can absorb and retain the liquid diffused by the fiber material 23.

As the highly absorbent polymer 22, various known materials used as a material for an absorbent body in an absorbent article such as a disposable diaper or a urine pad can be used. For example, starch-based products such as starch-acrylic acid (salt) graft copolymers, kendies of starch-acrylonitrile copolymers, and kendies of starch-ethylacrylic acid graft copolymers; cellulose such as crosslinked products of sodium carboxymethyl cellulose. System: A synthetic polymer system such as polyacrylic acid (salt), crosslinked polyethylene oxide with acrylic acid, and a crosslinked product of a polyvinyl alcohol-maleic anhydride reaction product can be used as the highly absorbent polymer 22. Among these, polyacrylic acid (salt) is preferable, and sodium polyacrylate is more preferable, from the viewpoint of absorbability. These may be used individually by 1 type and may be used in combination of 2 or more type. The shape of the highly absorbent polymer 22 is not particularly limited, and for example, granules, powders, pellets, sol, films, fibers and the like can be used.

For the production of the highly absorbent polymer 22, for example, an aqueous polymerization method in which a monomer, a cross-linking agent, and a polymerization initiator are dissolved in water to carry out polymerization, and an aqueous solution of the monomer, a cross-linking agent, and a polymerization initiator are placed in an organic solvent. It can be carried out by utilizing a polymerization technique with a reverse phase suspension polymerization method in which the polymer is dispersed and polymerized. The crosslinked polymer obtained by the aqueous solution polymerization method is usually obtained in the form of a lump, and is obtained as amorphous crushed particles by pulverization after the polymerization. On the other hand, the crosslinked polymer obtained by the reverse phase suspension polymerization method is usually obtained in the form of particles, so that pulverization is not required. In contrast to the crushed high-absorbent polymer particles obtained by using the aqueous solution polymerization method, the spherical high-absorbent polymer particles obtained by using the reverse-phase suspension polymerization method are the wrap sheet 24 when the recess 70 is formed. And the top sheet 31 is less likely to be torn. Therefore, the shape of the highly absorbent polymer 22 is more preferably granular, and even more preferably spherical, which is obtained by using the reverse phase suspension polymerization method.

Examples of the fiber material 23 include cellulosic fibers such as pulp fibers, rayon fibers and cotton fibers; and synthetic fibers such as polyethylene, polypropylene and polyethylene terephthalate which have been hydrophilized. Above all, from the viewpoint of absorbability, it is preferable to use fluff pulp obtained by crushing or defibrating fibers or synthetic fibers. These may be used individually by 1 type and may be used in combination of 2 or more type.

(Wrap sheet)
The wrap sheet 24 is a sheet-like member that covers the absorbent core 21. The wrap sheet 24 covers the entire absorbent core 21 including the skin facing surface side and the skin non-facing surface side of the absorbent core 21. By covering the absorbent core 21 with the wrap sheet 24, the morphology of the absorbent core 21 is ensured.
The wrap sheet 24 can be made of a known material used for absorbent articles. As the material constituting the wrap sheet 24, for example, paper such as tissue paper; spunbond non-woven fabric, needle punch non-woven fabric, spunlace non-woven fabric, air-through non-woven fabric, SMS (Spunbond Meltblown Spunbond) non-woven fabric and the like can be used.

<Top sheet>
The top sheet 31 is a sheet-like member arranged on the side facing the skin most in the laminated body 10. The top sheet 31 has a larger width direction than the absorber 20 and covers the entire surface of the absorber 20 from the skin facing surface side. Further, the top sheet 31 comes into contact with the wearer's skin in the worn state, permeates the excreted water, and is absorbed by the absorber 20. Therefore, the top sheet 31 is made of a material having at least a part of liquid permeability. Further, the top sheet 31 is preferably made of a material having high flexibility in order to ensure the fit to the wearer. Further, in order to suppress stuffiness in the mounted state, it is preferable that the material is made of a material having breathability.

As the material constituting the top sheet 31, for example, a woven fabric, a non-woven fabric, a porous film, or the like can be used. Alternatively, as the top sheet 31, a fiber of a thermoplastic resin such as polypropylene, polyethylene, polyester, nylon or the like may be hydrophilized to form a non-woven fabric. As the non-woven fabric constituting the top sheet 31, for example, spunbonded non-woven fabric, needle punched non-woven fabric, spunlace non-woven fabric, air-through non-woven fabric, melt blown non-woven fabric, SMS non-woven fabric and the like can be used.

<Back sheet>
The back sheet 32 is a sheet-like member arranged on the non-skin facing surface side of the laminated body 10. The back sheet 32 has a larger width direction than the absorber 20 and the top sheet 31, and covers the entire surface of the absorber 20 and the top sheet 31 from the skin non-opposing surface side. In addition, the back sheet 32 prevents excrement from leaking from the absorber 20 to the side not facing the skin. Therefore, the back sheet 32 is made of a material having liquid impermeable properties. Further, the back sheet 32 is preferably made of a material having moisture permeability in order to suppress stuffiness in the mounted state.

As the material constituting the back sheet 32, for example, a thermoplastic resin sheet such as polyethylene or polypropylene can be used. Above all, as the back sheet 32, it is preferable to use a microporous thermoplastic resin sheet in which a plurality of fine pores of 0.1 to 0.4 μm are formed. As such a sheet, for example, a sheet obtained by kneading an inorganic filler in a thermoplastic tree resin to form a sheet and then stretching the sheet can be used.

[Other sheets]
The disposable diaper 100 further includes a side sheet 33 and a cover sheet 35 that are laminated with respect to the laminated body 10. The side sheet 33, the cover sheet 35, and the laminate 10 can be fixed with a known adhesive such as a hot melt adhesive.

<Side seat>
The side sheets 33 are a pair of left and right members provided on both sides of the laminated body 10 in the width direction in order to form three-dimensional gathers 42 described later on both sides of the laminated body 10. The side sheet 33 is arranged from the outside in the width direction of the laminated body 10 to the skin facing surface side. As shown in FIG. 2, the side seat 33 extends outward in the width direction from the inseam 3 in the front body 2 and the front flap portion 34A extending outward in the width direction from the inseam 3. It has a flap portion 34B after it is taken out.

As shown in FIG. 3, the side seat 33 is provided so as to project outward in the width direction from the top seat 31 and the back seat 32. More specifically, the side sheet 33 is laminated on the skin facing surface side from the outer side in the width direction of the top sheet 31 and the back sheet 32 to the side portion. The side seat 33 stands up in the direction of contacting the wearer's skin (skin facing surface side) due to the contraction of the three-dimensional gather 42.

The side sheet 33 is preferably made of a non-liquid permeable material in order to prevent liquid leakage to the outside in the width direction. As the side sheet 33, a spunbonded non-woven fabric can be used. Further, a part of the side sheet 33 is arranged on the side facing the skin most in the disposable diaper 100 (for this reason, the side sheet 33 is also referred to as a "top sheet" like the top sheet 31). As the side sheet 33 that can come into contact with the wearer in this way, a spunbonded non-woven fabric having increased flexibility by including a melt blown layer such as SMS non-woven fabric or SMMS (Spunbond Meltblown Meltblown Spunbond) non-woven fabric is used. Is preferable. Alternatively, it is preferable to use a spunbonded nonwoven fabric having improved flexibility by suppressing the fineness and basis weight of the fibers forming the spunbonded nonwoven fabric.

The "fineness" is a parameter corresponding to the fiber diameter (thickness) and the cross-sectional area of the fiber, and is represented by the weight per predetermined length. For example, the number of grams per 10,000 m (decitex) for one fiber is used as the "fineness". The "weight of basis weight" is a parameter corresponding to the thickness or the degree of stacking of the sheets, and is expressed by the weight per unit area. For example, the number of grams per square meter is used as the "weight".

<Cover sheet>
The cover sheet 35 is a sheet-like member that covers the laminated body 10 from the skin non-opposing surface side. The cover sheet 35 is used to reinforce the back sheet 32 and improve the feel (tactile feeling) of the back sheet 32 by arranging the cover sheet 35 on the non-skin facing surface side of the disposable diaper 100 except for the patch 38. Be done. The cover sheet 35 has a larger width direction than the absorber 20, the top sheet 31, and the back sheet 32, and is arranged around the wearer's inseam, buttocks, waist, abdomen, and the like in the worn state. As shown in FIG. 2, the cover sheet 35 has a pair of left and right front flap portions 36A extending outward in the width direction from the inseam 3 in the front body 2, and a width direction from the inseam 3 in the rear body 4. It has a pair of left and right rear flap portions 36B extending outward.

Examples of the material constituting the cover sheet 35 include woven fabrics and non-woven fabrics. Above all, it is preferable to use a non-woven fabric made of a thermoplastic resin such as polyethylene, polypropylene or polyester, or a wet non-woven fabric. In particular, in order to secure the tactile sensation (touch), a spunbonded nonwoven fabric can be preferably used as the cover sheet 35 from the viewpoint of flexibility.

In the disposable diaper 100 configured as described above, the side sheet 33, the top sheet 31, the absorber 20, the back sheet 32, and the cover sheet 35 are laminated in this order from the skin facing surface side to the skin non-facing surface side. Has been done. The side sheet 33 and the cover sheet 35 are bonded to each other by a known adhesive such as a hot melt adhesive. Then, the front side flaps 5 are formed by the front flap portions 34A and 36A of the side seat 33 and the cover sheet 35. Further, the rear side flaps 6 are formed by the rear flap portions 34B and 36B of the side sheet 33 and the cover sheet 35, respectively.

[Fastening mechanism]
The fastening mechanism realizes a fastening function between the front body 2 and the back body 4. As the fastening mechanism, for example, a planar fastener (mechanical fastener) that is mechanically connected by a hook member (male member) and a loop member (female member) can be used. The hook member referred to here is a sheet-like member in which a large number of protrusions such as hook-shaped, mushroom-shaped, and anchor-shaped are formed on the surface. Further, the loop member referred to here is a sheet-like member having loop-shaped fibers arranged on the surface or made of a non-woven fabric composed of short fibers. Further, as the fastening mechanism, an adhesive or an adhesive tape can be used. Among them, a planar fastener is preferable because the hook member and the loop member can be firmly fixed and the hook member and the loop member can be peeled off and used repeatedly. In this embodiment, the case where the tape 60 functions as a hook member and the patch 38 functions as a loop member is illustrated.

<Patch>
The patch 38 of the present embodiment is attached to the outer surface of the front body 2 of the cover sheet 35 (the most non-skin facing surface side of the disposable diaper 100). As the patch 38, for example, a non-woven fabric made of fibers of a thermoplastic resin such as polypropylene, polyethylene, polyester, or nylon is used.

<Tape>
The tape 60 can be attached to the patch 38, and when the disposable diaper 100 is bent toward the skin facing surface side so that the front body 2 and the back body 4 face each other with the inseam 3 as the center, the tape 60 is in the width direction. It is pulled outwards and fastened to patch 38. The disposable diaper 100 is attached to the wearer by the tape 60 being fastened to the patch 38 in this way.

As shown in FIGS. 1 and 2, the tape 60 has a sheet-shaped fastening portion 61 which is fixed to the rear side flap 6 and is provided so as to project outward from the rear side flap 6. Further, a locking member 64, which is a hook member for fixing the front body 2 and the rear body 4, is provided on the skin-facing surface side of the fastening portion 61. The fastening portion 61 fastens the front body 2 and the rear body 4 via the locking member 64 and the patch 38.

The fastening portion 61 has a base portion 62 inside in the width direction and a protruding portion 63 protruding outward in the width direction from the base portion 62. The base portion 62 is fixed to the rear side flap 6 by being narrowed between the rear flap portions 34B and 36B of the side seat 33 and the cover sheet 35. The projecting portion 63 is provided in a state of being exposed to the outside by projecting outward from the side sheet 33 and the cover sheet 35 in the width direction. A locking member 64 is provided on the skin-facing surface side of the protrusion 63.

As the material constituting the fastening portion 61 of the tape 60, for example, a woven fabric, a non-woven fabric, a resin film, paper or the like can be used. As the material constituting the woven fabric, the non-woven fabric, or the resin film, for example, a thermoplastic resin such as polyethylene, polypropylene, polyamide, polyester, polyvinyl chloride, and polystyrene can be used.

〔gather〕
The disposable diaper 100 is provided with gathers 41 to 43 in order to improve the followability to the wearer in the worn state. Gathers 41 to 43 are made by sandwiching elastic members (elastic members) such as rubber, polyurethane, and elastic film between sheets such as non-woven fabric in a stretched state, and fixing them by hot melt, heat sealing, ultrasonic welding, etc. It is composed of a sheet composite with elasticity. In this sheet composite, fine wrinkles are formed on the sheet due to the force (restoring force, elastic force) that the elastic member tries to return from the stretched state to the original state (natural length state). Here, thread-shaped rubber members (hereinafter, abbreviated as “thread rubber”) 51 to 53 are exemplified as the elastic members.

In the present embodiment, as the gathers 41 to 43, three types to which elasticity is imparted by the three types of thread rubbers 51 to 53 are exemplified. One is a leg gather 41 in which each end portion in the width direction of the back sheet 32 and the cover sheet 35 and the outer end portion in the width direction of the side sheet 33 are wrinkled by the first thread rubber 51. The other is a three-dimensional gather 42 in which the inner end portion of the side sheet 33 in the width direction is wrinkled by the second thread rubber 52. The remaining one is a waist gather 43 in which each end of the top sheet 31, the back sheet 32, the side sheet 33, and the cover sheet 35 on the back side in the longitudinal direction is wrinkled by the third thread rubber 53.

The leg gather 41 is provided to enhance the followability to the wearer's leg (suppress the gap between the wearer's leg and the disposable diaper 100). As shown in FIG. 1, the leg gather 41 is provided at a position surrounding the wearer's leg in the worn state. As shown in FIGS. 2 and 3, the first thread rubber 51 is provided on the skin facing surface side at the end portion in the width direction of the back sheet 32, and is interposed between the back sheet 32 and the side sheet 33. Will be done.

The three-dimensional gather 42 is provided on the side of the excretion point in order to improve the followability to the wearer. The three-dimensional gather 42 has a function of preventing the excrement from leaking outward in the width direction. As shown in FIG. 1, the three-dimensional gather 42 is arranged inside the side seat 33 in the width direction. As shown in FIGS. 2 and 3, the second thread rubber 52 is provided at the inner end portion in the width direction of the side sheet 33, and the inner end portion is bent toward the non-skin facing surface portion to be doubled. It is interposed between the superposed portions 33A and 33B.

The waist gather 43 is provided to enhance the followability to the wearer's buttocks and lower abdomen. As shown in FIG. 1, the waist gather 43 is deployed between the left and right rear side flaps 6. As shown in FIG. 2, the waist gather 43 of the present embodiment is formed by narrowing a plurality of stretched third thread rubbers 53 extending in the width direction to a set of non-stretchable base material sheets. It is composed of an elastic sheet 54. The telescopic sheet 54 is interposed between the top sheet 31 and the back sheet 32 and the cover sheet 35.

[1-2. Detailed configuration]
Next, the detailed configuration of the disposable diaper 100 will be described.

As shown in FIG. 1, a recess 70 is provided on the skin-facing surface side of the laminated body 10. The recess 70 is a portion of the laminated body 10 in which a part of the recess 70 is lower than the periphery in the thickness direction. Specifically, the recess 70 is a squeezed portion in which the absorber 20 and the top sheet 31 are squeezed in the thickness direction. The recess 70 is provided in the region of the laminated body 10 where the absorber 20 is present. In this embodiment, a case where the groove-shaped recesses 70 are provided in a grid pattern is illustrated. That is, the recesses 70 of the present embodiment are extended in a plurality of lines that intersect each other in a plan view of the laminated body 10. Therefore, the recess 70 includes an intersection 73 (only a part thereof is designated) in which the linearly extending portions intersect with each other.

The recess 70 has a first inclined portion 71 (partially marked) and a second inclined portion 72 (partially designated) that intersect each other. That is, the first inclined portion 71 and the second inclined portion 72 form a grid shape (grid pattern) in a plan view. The first inclined portion 71 is a linear portion inclined in one of the width directions (for example, to the right) with respect to the longitudinal direction. On the other hand, the second inclined portion 72 is a linear portion inclined to the other side (for example, to the left) in the width direction with respect to the longitudinal direction. As described above, both the first inclined portion 71 and the second inclined portion 72 are extended in a straight line intersecting both the longitudinal direction and the width direction in the plan view of the laminated body 10. In the laminated body 10 of the present embodiment, a plurality of first inclined portions 71 are provided in parallel with each other, and a plurality of second inclined portions 72 are also provided in parallel with each other.

According to the recess 70 described above, the absorber 20 and, in addition to the absorber 20, the top sheet 31 and the back sheet 32, and the disposable diaper 100 are easily bent at the extending portion of the recess 70, and the fit of the disposable diaper 100 to the wearer is improved. It will be secured. Further, air permeability is ensured by the air flowing through the recess 70. Further, by diffusing the excreted water along the recess 70, the absorption points of the absorber 20 and the absorbent core 21 are dispersed throughout, thereby enhancing the absorbent power and the holding power of the absorbent body 20 and the absorbent core 21. be able to.

In order to maintain the shape of the recess 70, an adhesive portion may be formed at the position of the recess 70 in the top sheet 31, the wrap sheet 24, and the absorbent core 21. At the bonding portion, at least two or more sheets selected from the wrap sheet 24 included in the laminated body 10, the top sheet 31 on the skin facing surface side and the skin non-facing surface side, and the back sheet 32 are bonded. The bonded portion can be formed by a known method such as hot melt adhesive, heat sealing, or ultrasonic welding. Above all, it is preferable that the absorbent core 21 and the wrap sheet 24 are bonded to each other in the recess 70 via a hot melt adhesive.

Further, it is preferable that the absorbent core 21 and the wrap sheet 24 are not substantially heat-sealed in the recess 70. The term "substantially not heat-sealed" as used herein means that the intended heat-sealing is not performed. In the above description, the case where the recess 70 is provided on the skin facing surface side of the laminated body 10 has been described as an example, but the configuration of the recess 70 is not limited to this, and the skin facing surface side and the skin are not limited to this. It may be provided on both sides on the non-opposing surface side.

At the position corresponding to the recess 70 of the absorbent core 21, the content of the highly absorbent polymer 22 is 75 g / m ² or more, preferably 90 g / m ² or more, more preferably 110 g / m ² or more, still more preferably 120 g. / M ² or more, 300 g / m ² or less, preferably 250 g / m ² or less, more preferably 200 g / m ² or less, still more preferably 170 g / m ² or less, particularly preferably 150 g / m ² or less, most preferably. Is 130 g / m ² or less. When the content of the highly absorbent polymer 22 is at least the above lower limit value, the shape of the recess 70 is likely to be maintained by the highly absorbent polymer 22. That is, in this case, the performance of maintaining the shape of the recess 70 (hereinafter referred to as "shape maintaining performance of the recess 70") is likely to be exhibited. Further, when the content of the highly absorbent polymer 22 is not more than the above upper limit value, the flexibility of the absorbent core 21 is easily ensured, so that the wrap sheet 24 and the top sheet 31 are less likely to be damaged. That is, in this case, it is easy to prevent the highly absorbent polymer 22 from leaking from the wrap sheet 24 or the top sheet 31 (hereinafter referred to as “polymer leakage”). In addition, "g / m ² " is a unit representing the weight (basis weight) per unit area in a plan view. Further, the above-mentioned "position corresponding to the recess 70 of the absorbent core 21" is a position of the absorbent core 21 that overlaps with the recess 70 in a plan view.

Further, at the position corresponding to the recess 70 of the absorbent core 21, the content of the fiber material 23 is 75 g / m ² or more, preferably 90 g / m ² or more, more preferably 100 g / m ² or more, still more preferably 105 g. / M ² or more, 250 g / m ² or less, preferably 200 g / m ² or less, more preferably 150 g / m ² or less, still more preferably 110 g / m ² or less. When the content of the fiber material 23 is at least the above lower limit value, the absorbability of excreted water is ensured and the flexibility of the absorbent core 21 is ensured, so that polymer leakage is easily prevented. Further, when the content of the fiber material 23 is not more than the above upper limit value, the elastic force acting on the wrap sheet 24 from the fiber material 23 is suppressed, so that the highly absorbent polymer 22 is difficult to get into the wrap sheet 24 and the top sheet 31. Therefore, the shape maintenance performance of the recess 70 is likely to be exhibited.

As shown in FIG. 4, in the absorbent core 21, the thickness T1 of the portion where the concave portion 70 is not provided (hereinafter referred to as “convex thickness”) is 1.7 mm or more, 3.0 mm or less, and the concave portion 70. It is preferable that the thickness (hereinafter referred to as “concave thickness”) T2 of the portion provided with the above is 1.5 mm or more and 2.8 mm or less. That is, in the process of forming the recess 70, the position corresponding to the recess 70 of the absorbent core 21 is squeezed from a thickness of 1.7 mm or more and 3.0 mm or less to a thickness of 1.5 mm or more and 2.8 mm or less. It is preferable to be done. When the convex thickness T1 and the concave thickness T2 of the absorbent core 21 are values within the above ranges, the actions and effects obtained by the above-mentioned provisions of the contents of the highly absorbent polymer 22 and the fiber material 23 are appropriate. Easy to demonstrate.

For example, when the convex thickness T1 is lower than the above range or the concave thickness T2 is higher than the above range even if the contents of the highly absorbent polymer 22 and the fiber material 23 are within the above ranges. Since the highly absorbent polymer 22 is difficult to get into the wrap sheet 24 or the top sheet 31, the shape of the recess 70 may not be maintained. Further, even if the contents of the highly absorbent polymer 22 and the fiber material 23 are within the above ranges, if the convex thickness T1 exceeds the above range or the concave thickness T2 falls below the above range, If the highly absorbent polymer 22 is too tightly packed in the wrap sheet 24 or the top sheet 31, polymer leakage may occur. On the other hand, if the contents of the highly absorbent polymer 22 and the fiber material 23 and the convex thickness T1 and the concave thickness T2 are within the above ranges, the shape maintenance performance of the concave portion 70 is enhanced and the polymer leaks. Is more likely to be prevented.

The absorbent core 21 may also contain the highly absorbent polymer 22 and the fiber material 23 in the above-mentioned contents at positions other than the positions corresponding to the recesses 70. That is, the highly absorbent polymer 22 contained in the absorbent core 21 may be uniformly contained in the entire absorbent core 21 at the above-mentioned content.

Alternatively, the contents of the highly absorbent polymer 22 and the fibrous material 23 may be higher in the positions corresponding to the recesses 70 of the absorbent core 21 than those in the other positions. Such a content setting is such that, for example, when an absorbent material including the highly absorbent polymer 22 and the fiber material 23 is deposited to form the absorbent core 21, the high absorbent polymer 22 is absorbed in a high content. This can be achieved by properly using a sex material and a low absorbency material for each region. Specifically, first, an absorbent material having a high content of the highly absorbent polymer 22 is deposited in the region where the recess 70 is formed. Subsequently, the absorbent material having a low content of the highly absorbent polymer 22 may be deposited in the region other than the region where the recess 70 is formed or the entire region where the absorbent core 21 is formed. Even in this case, the shape maintenance performance of the recess 70 is enhanced as described above.

In terms of industrial production, it is preferable that the contents of the highly absorbent polymer 22 and the fiber material 23 contained in the entire absorbent core 21 are the above-mentioned contents. In this embodiment, the case where the highly absorbent polymer 22 and the fiber material 23 are contained in a uniform content throughout the absorbent core 21 is illustrated.

[2. Production method]
The process (manufacturing method) for manufacturing the above-mentioned disposable diaper 100 will be described.

As shown in FIG. 7, first, an absorbent material containing a highly absorbent polymer 22 and a fiber material 23 is deposited to prepare a mat-shaped absorbent core 21, and the above-mentioned wrap sheet 24 is attached to the absorbent core 21. It is coated to obtain the absorber 20 (first step, step S1). At this time, at the position corresponding to the recess 70 of the absorbent core 21 (the position where the recess 70 is planned to be formed), the content of the highly absorbent polymer 22 and the content of the fiber material 23 are within the above ranges, respectively. The value in. Specifically, the content of the highly absorbent polymer 22 is 75 g / m ² or more and 300 g / m ² or less, and the content of the fiber material 23 is 75 g / m ² or more and 250 g / m ² or less.

Next, the above-mentioned top sheet 31 is arranged on the surface of the absorber 20 on the skin-facing surface side to obtain the laminated body 10 (second step, step S2). The laminated body 10 referred to here is a laminated structure composed of the absorber 20 and the top sheet 31, and corresponds to the laminated body 10 in the above-mentioned disposable diaper 100 excluding the cover sheet 35.

Subsequently, the laminate 10 composed of the absorber 20 and the top sheet 31 is passed between the pair of rolls 81 and 82 (see FIG. 8), and the absorber 20 and the top sheet 31 are squeezed in the thickness direction (lamination direction). , A recess 70 is provided on the skin-facing surface side of the laminated body 10 (third step, step S3).

In the present embodiment, as described above, the groove-shaped recesses 70 are provided in a grid pattern (a plurality of linear shapes intersecting each other) with respect to the laminated body 10. That is, of the pair of rolls 81 and 82, one of the press rolls 81 (upper side in FIG. 8) is provided with a convex shape 81a for forming a groove-shaped concave portion 70 in a grid pattern. The shape (pattern) of the concave portion 70 can be formed so as to meet the conditions of a desired position, shape, and depth according to the shape of the convex shape 81a.

In the present embodiment, the convex type 81a of the press roll 81 and the outer peripheral surface 82a of the anvil roll 82 facing the convex type 81a rotate the rolls 81 and 82 while sandwiching the laminated body 10 to be conveyed, and press rolls. The laminated body 10 is pressed (compressed) from the skin facing surface side with the convex shape 81a of 81. At this time, the air contained in the pressed portion of the laminated body 10 is squeezed. As a result, the absorbent core 21, the wrap sheet 24, and the top sheet 31 mesh with each other and are fixed. As a result, the above-mentioned recess 70 is press-formed in the laminated body 10.
By using the pair of rolls 81 and 82 in this way, the recess 70 can be continuously formed. Further, by forming the squeezed portion formed by squeezing the laminated body 10 in the thickness direction into the recess 70, the recess 70 can be formed relatively easily, and the dimensions of the recess 70 as described above can be formed. The setting can be realized accurately.

When the laminate 10 is passed between the rolls 81 and 82, the clearance CL between the rolls 81 and 82 is 0.1 mm or more, more preferably 0.15 mm or more, still more preferably 0.2 mm or more, and 0.5 mm or less. , More preferably 0.45 mm or less, still more preferably 0.4 mm or less. The clearance CL referred to here corresponds to the shortest distance between the tip of the convex 81a of the press roll 81 and the outer peripheral surface 82a of the anvil roll 82.

When the clearance CL is less than 0.1 mm, the concave thickness T2 of the laminated body 10 tends to fall below the above range. Therefore, if the highly absorbent polymer 22 is too tightly packed in the wrap sheet 24 or the top sheet 31, the laminated body 10 may be torn in the recess 70 (polymer leakage occurs), and the flexibility of the laminated body 10 is lowered. Cheap. On the other hand, when the clearance CL is larger than 0.5 mm, the concave thickness T2 of the laminated body 10 tends to exceed the above range. Therefore, the highly absorbent polymer 22 is difficult to get into the wrap sheet 24 or the top sheet 31, and the recess 70 may not be properly formed (the shape of the recess 70 cannot be maintained). On the other hand, if the clearance CL is within the above range, the concave thickness T2 tends to be within the above range. Therefore, the shape maintaining performance of the recess 70 is enhanced, polymer leakage is easily prevented, and the flexibility of the laminated body 10 is ensured.

When the laminated body 10 is passed between the rolls 81 and 82, the pressure (press pressure) P applied to the laminated body 10 from the rolls 81 and 82 is 1.2 MPa or more, more preferably 1.3 MPa or more, still more preferable. Is 1.4 MPa or more, 2.0 MPa or less, more preferably 1.9 MPa or less, still more preferably 1.8 MPa or less. This press pressure P is for maintaining the above-mentioned clearance CL against the reaction force acting on the rolls 81 and 82 from the laminated body 10 passing between the rolls 81 and 82.

When the press pressure P is equal to or higher than the above lower limit value, the clearance CL between the rolls 81 and 82 is likely to be maintained below the above upper limit value even if a reaction force acts on the rolls 81 and 82 from the laminated body 10. Therefore, the shape maintenance performance of the recess 70 is enhanced. Further, when the press pressure P is not more than the above upper limit value, excessive pressurization of the laminate 10 by the rolls 81 and 82 is likely to be prevented. Therefore, it becomes easy to prevent polymer leakage, and it becomes easy to secure the flexibility of the laminated body 10.

Since the shaft temperature of each of the rolls 81 and 82 may fluctuate due to the influence of the ambient temperature (room temperature), it is preferable to set (steady) the temperature to be higher than the ambient temperature.
Further, in the step of manufacturing the disposable diaper 100, it is preferable that the absorbent core 21 and the wrap sheet 24 are not substantially heat-sealed in the recess 70 as described above.
Further, as described above, a step of forming an adhesive portion at the position of the recess 70 in the laminated body 10 may be provided. For example, the absorbent core 21 and the wrap sheet 24 may be bonded to each other via a hot melt adhesive at a position corresponding to the recess 70 of the laminated body 10 (fourth step).

[3. Action and effect]
Since the disposable diaper 100 of the present embodiment is manufactured by the above-mentioned manufacturing method, the following actions and effects can be obtained.

Conventionally, it has been proposed to form a recess in the thickness direction with respect to the absorber. When the absorber is provided with a recess, the elasticity of the fibrous material contained in the absorbent core may cause the recess to be deformed so as to be restored to a flat surface. For this reason, it may not be possible to maintain the shape of the absorber having the recessed portion in the process of transporting or storing the disposable diaper. When the disposable diaper is deformed in this way, the function of the concave portion of the absorber may be impaired.

(1) In the disposable diaper 100, the recess 70 is provided in the laminated body 10, and the contents of the highly absorbent polymer 22 and the fiber material 23 at the positions corresponding to the recess 70 of the absorbent core 21 are each within a predetermined range. It has become. Further, when manufacturing the disposable diaper 100, the clearance CL between the rolls 81 and 82 for pressing the laminated body 10 and the press pressure P for the rolls 81 and 82 are values within predetermined ranges, respectively. Therefore, when the absorber 20 and the top sheet 31 are squeezed in the thickness direction by the rolls 81 and 82, the highly absorbent polymer 22 is placed on the wrap sheet 24 or the top sheet at the position corresponding to the recess 70 of the absorbent core 21. By inserting the 31 into the bag, the adhesion between the absorbent core 21 and the wrap sheet 24 or the top sheet 31 is strengthened. Therefore, the shape maintenance performance of the recess 70 is enhanced.

As described above, in the disposable diaper 100, a part of the highly absorbent polymer 22 functions as a binder by penetrating into the wrap sheet 24 as the recess 70 is formed, so that the adhesiveness (bondability) is improved. It is presumed that the action can be obtained. Further, it is presumed that the effect of improving the adhesiveness can be similarly obtained for the top sheet 31 and the back sheet 32 laminated on the wrap sheet 24. Further, the highly absorbent polymer 22 enters the voids of the fiber material 23 to generate an anchor effect that mechanically enhances the adhesive force, and the adhesive force enhanced by this anchor effect resists the elastic force of the fiber material 23. Therefore, it is considered that the shape of the recess 70 in the absorbent core 21 can be easily maintained.

Therefore, according to the disposable diaper 100, the shape maintaining performance of the recess 70 can be improved. Then, by maintaining the shape of the recess 70, the function of the recess 70 can be more reliably exhibited. Further, according to the disposable diaper 100, as described above, the contents of the highly absorbent polymer 22 and the fiber material 23 are each within a predetermined range, so that the flexibility of the absorbent core 21 is ensured. It is possible to easily prevent polymer leakage. Further, since the clearance CL and the press pressure P between the rolls 81 and 82 described above are each within the predetermined ranges, the highly absorbent polymer 22 is prevented from being too tightly packed in the wrap sheet 24 and the top sheet 31, and is laminated. The concave thickness T2 of the body 10 is secured. This also makes it easy to prevent polymer leakage and secures the flexibility of the absorbent core 21.

Since the recess 70 is provided on the surface facing the skin, the disposable diaper 100 is easily bent on the surface facing the skin, so that the fit of the disposable diaper 100 to the wearer can be ensured. Further, since the recess 70 forms a space between the wearer's skin and the absorber 20, air can be circulated through this space. Therefore, breathability can be ensured. Further, by diffusing the excreted water through this space, the absorption portion of the absorber 20 can be dispersed. Thereby, the absorption power and the holding power on the skin facing surface side of the absorber 20 can be enhanced.

(2) Since the recess 70 is not substantially heat-sealed, it is possible to prevent the stack 10 from becoming stiff due to heat fusion and improve the wearing feeling of the disposable diaper 100. Further, in the disposable diaper 100, it is possible to maintain the shape of the recess 70 without heat fusion. Further, the work process for performing heat fusion is not required, which is industrially advantageous.

(3) Since the absorbent core 21 and the wrap sheet 24 are bonded to each other at a position corresponding to the recess 70 via a hot melt adhesive, the adhesive force in the recess 70 can be enhanced. Further, the hot melt adhesive contributes to the formation of the recess 70 and the maintenance of the shape.

(4) Since the recess 70 is provided in a groove shape, air or liquid can move through the continuously formed recess 70. Therefore, it is possible to improve the wearing feeling by the concave portion 70 and the effect of increasing the absorbing power and the holding power by diffusing the liquid.

(5) Since the recesses 70 are provided in a plurality of linear shapes that intersect with each other, the recesses 70 include an intersection 73 in which the linear portions intersect with each other. Conventionally, this intersection 73 tends to be subjected to a large pressure when squeezed by the rolls 81 and 82 as compared with other parts of the recess 70, so that the concave thickness T2 tends to be small and polymer leakage is likely to occur. .. On the other hand, according to the disposable diaper 100, as described above, the concave portion 70 includes the intersection 73 because the flexibility of the absorbent core 21 is secured in the concave portion 70 and the concave thickness T2 is secured. Also, it is possible to easily prevent polymer leakage.

(6) Since the recesses 70 are provided in a grid pattern, the tactile sensation on the surface of the laminate 10 surrounded by the grid-shaped recesses 70 is improved. When the recesses 70 are formed in a grid pattern and provided in a continuous annular shape, the recesses 70 may easily rise in the thickness direction, but according to the disposable diaper 100, the shape of the recesses 70 is as described above. Since the maintenance performance is enhanced, it is possible to easily maintain the shape of the recess 70 even if it has a grid pattern.

Hereinafter, the present invention will be specifically described with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the present invention is not limited to the following examples.

[Example 1]
An absorbent material, which is a mixture of a highly absorbent polymer and a fiber material, was deposited to obtain a mat-like absorbent core. Here, spherical particles made from sodium polyacrylate as a raw material were used as a highly absorbent polymer, and pulp fibers were used as a fiber material. In this absorbent core, the highly absorbent polymer and fibrous material were uniformly distributed regardless of the position of the recesses. That is, the contents of the highly absorbent polymer and the fibrous material were uniform in all regions of the absorbent core. As shown in Table 1 below, in this absorbent core, the content of the highly absorbent polymer (SAP amount) and the content of the fiber material (pulp amount) are 75 g, which are the lower limit values of the above-mentioned ranges, respectively. It was / m ² .

Next, a hydrophilic spunbonded nonwoven fabric having a basis weight of 16 gsm (g / m ² ) was used as a wrap sheet, and the above-mentioned absorbent core was coated with this wrap sheet to obtain an absorber. The area of this absorber on the skin-facing surface side was 0.0284 m ² . Subsequently, a non-woven fabric having a basis weight of 22 gsm (manufactured by Fukusuke Kogyo Co., Ltd., model number: FZ2) was used as a top sheet, and this top sheet was laminated on the above-mentioned absorber to obtain a laminated body. Further, the laminate is passed between a pair of rolls to squeeze the absorber and the top sheet in the thickness direction, and a grid-like recess shown in FIG. 1 is formed on the skin facing surface side of the laminate to form Example 1. The laminated body of was produced. That is, the formation of the concave portion was performed by passing a laminated body between the press roll having a grid-like convex shape and the anvil roll facing the press roll.

As shown in Table 1, in the laminated body of Example 1, the convex thickness T1 and the concave thickness T2 were values within the above ranges, respectively. The convex thickness T1 and the concave thickness T2 were adjusted by adjusting the clearance CL between the rolls passing through the laminated body and the press pressure P applied to the laminated body from these rolls. As shown in Table 1, when the laminate of Example 1 was produced, the clearance CL and the press pressure P were values within the above ranges, respectively. The shaft temperature of the press roll and the anvil roll was set to 60 ° C., which is higher than the ambient temperature (room temperature).

[Examples 2 to 4]
As shown in Table 1, with respect to the laminate of Example 1, only the pulp amount was increased to 150 g / m ^{2, 200 g / m 2, and 250 g / m 2 , which} are within the above range, respectively. It was set to 2-4. The laminates of Examples 2 to 4 are the same as those of Example 1 except for the amount of pulp, and when the laminates of Examples 2 to 4 are produced, the convex thickness T1 and the concave thickness T2 are examples. The clearance CL and the press pressure P were adjusted so as to be the same as those in 1. Also in Examples 2 to 4, the clearance CL and the press pressure P were values within the above ranges, respectively.

[Examples 5 to 7]
As shown in Table 1, the laminates of Examples 2 to 4 in which only the SAP amount was increased to 200 g / m ² within the above range were designated as Examples 5 to 7, respectively. The laminates of Examples 5 to 7 are the same as those of Examples 2 to 4 except for the amount of SAP, and the convex thickness T1 and the concave thickness T2 are also used when the laminates of Examples 5 to 7 are manufactured. The clearance CL and the press pressure P were adjusted so that Also in Examples 5 to 7, the clearance CL and the press pressure P were values within the above ranges, respectively.

[Examples 8 to 10]
As shown in Table 1, the laminates of Examples 2 to 4 in which the SAP amount was increased to 300 g / m ² , which is the upper limit of the above range, were designated as Examples 8 to 10, respectively. The laminates of Examples 8 to 10 are the same as those of Examples 2 to 4 except for the amount of SAP, and the convex thickness T1 and the concave thickness T2 are also used when the laminates of Examples 8 to 10 are manufactured. The clearance CL and the press pressure P were adjusted so that Also in Examples 8 to 10, the clearance CL and the press pressure P were values within the above ranges, respectively.

[Examples 11 to 19]
As shown in Table 1, with respect to the laminate of Example 6, the clearance CL and the press pressure P at the time of production were increased or decreased within the above range while maintaining the SAP amount and the pulp amount, in Examples 11 to 11. It was set to 19. That is, the laminated bodies of Examples 11 to 19 have different convex thickness T1 and concave thickness T2, respectively, because the clearance CL and the press pressure P at the time of manufacture are different from those of Example 6. .. In Examples 11 to 19, the convex thickness T1 and the concave thickness T2 were values within the above ranges, respectively.

[Comparative Examples 1 to 13]
As shown in Table 1, Comparative Examples 1 to 13 were obtained by setting at least one of the SAP amount and the pulp amount to a value outside the above range. Specifically, those in which only the SAP amount is smaller or larger than the above range are designated as Comparative Examples 1 to 4, 11 to 13, and those in which only the pulp amount is smaller or larger than the above range are compared with Comparative Examples 5 to 5. It was set to 10. The laminates of Comparative Examples 1 to 13 are the same as those of Example 1 except for the amount of SAP and the amount of pulp, and when the laminates of Comparative Examples 1 to 13 are produced, the convex thickness T1 and the concave thickness T2 are used. The clearance CL and the press pressure P were adjusted so that

[Comparative Examples 14 and 15]
As shown in Table 1, Comparative Examples 14 and 15 were obtained by setting both the SAP amount and the pulp amount to values outside the above range. The laminates of Comparative Examples 14 and 15 are the same as those of Example 1 except for the amount of SAP and the amount of pulp. When the laminates of Comparative Examples 14 and 15 are produced, the convex thickness T1 and the concave thickness T2 are used. The clearance CL and the press pressure P were adjusted so that

[Comparative Examples 16 to 23]
As shown in Table 1, comparison of the laminate of Example 6 in which at least one of the clearance CL and the press pressure P at the time of production was set to a value outside the above range while maintaining the SAP amount and the pulp amount. Examples 16 to 13 were used. Specifically, those in which at least the clearance CL is smaller than the above range are referred to as Comparative Examples 16 to 18, those in which only the press pressure P is out of the above range are referred to as Comparative Examples 19 and 20, and at least the clearance CL is described above. The ones larger than the range of were designated as Comparative Examples 21 to 23. Since the laminates of Comparative Examples 16 to 23 have different clearance CL and press pressure P at the time of manufacture from those of Example 6, the convex thickness T1 and the concave thickness T2 are also different from each other.

[Evaluation method]
The following fixing rate measurement and polymer leakage test were performed on the laminates of Examples 1 to 19 and Comparative Examples 1 to 23 to evaluate the shape maintenance performance and the polymer leakage.

<Measurement of retention rate>
The paper diapers provided with the laminated bodies of each example and the comparative example were gently attached to a flat drawing board so that the skin-facing surface side of the laminated body was exposed, and used as an evaluation sample. Here, five evaluation samples of each example and comparative example were prepared. Subsequently, as shown by a thick line in FIG. 5, among the grids formed by the recesses, three straight and continuous grids were set as one set, and five sets at intervals were set as measurement targets. That is, assuming that each of the four linear portions forming one lattice in the recess is a "side", 50 sides are the measurement targets in each evaluation sample. The side to be measured is not limited to this, and may be appropriately changed according to the configuration of the concave portion.

Next, the tip of the pen was moved by touching it near the side of each evaluation sample, and it was confirmed whether the top sheet had a float. More specifically, it was determined that the top sheet was lifted when the recess disappeared or the wrap sheet or back sheet moved with the movement of the pen. When it was difficult to make a judgment, the part to be measured was pulled, and when the side disappeared completely (it could not be seen), it was judged that the top sheet had a float. In addition, for each side, if the part where the float is seen on the top sheet is larger than half, it is judged as "NG", and when the part where the float is seen on the top sheet is less than half, it is "OK". It was judged. Then, in each evaluation sample, the number of sides determined to be "NG" (hereinafter referred to as "NG number") Nn was counted.

Subsequently, for each Example and Comparative Example, the average value Nm of the five NG numbers Nn obtained from the five evaluation samples was calculated. Then, this average value Nm and the number of sides Nt (here, 50) as the measurement target were applied to the following formula (1) to calculate the fixing rate.
Retention rate [%] = (1-Nm / Nt) x 100 ... (1)

As shown by the formula (1), the fixing rate is the ratio of the sides determined to be "OK" among the sides to be measured. That is, the fixing rate represents the shape-maintaining performance of the recess 70, and the larger the value is, the stronger the recess 70 is formed, and the higher the shape-maintaining performance of the recess 70 is. The retention rate is usually 89% or more, preferably 90% or more, more preferably 95% or more, still more preferably 98% or more.

<Polymer leak test>
As shown in FIG. 6, a 200-mesh wire mesh 12 was fixed to the open side of the U-shaped acrylic plate 11 to prepare a mesh acrylic plate 13. Next, the mesh acrylic plate 13 was installed in a container 14 larger than the mesh acrylic plate 13 with the wire mesh 12 facing up. Further, the saline solution 15 was injected into the container 14 to wet the entire wire mesh 12 while preventing the wire mesh 12 from being immersed in the saline solution 15. Then, a small amount of physiological saline 15 was scooped out with a disposable cup to remove the air that had entered under the wire mesh 12.

Subsequently, holding the dorsal side and the ventral side of the paper diapers of each example and the comparative example, while keeping the paper diapers parallel to the wire mesh 12, the skin-facing surface side (top sheet side) is brought into contact with the wire mesh 12 from above and fluttering. And expanded and contracted 10 times. Then, the number of highly absorbent polymers (hereinafter referred to as "the number of polymers") that fell on the wire mesh 12 was counted. More specifically, the number of highly absorbent polymers having a particle size of 0.5 to 1 mm (hereinafter referred to as "the number of small polymers") in each of the three regions corresponding to the front body, crotch part and back body of the paper diaper. N1 and the number of highly absorbent polymers having a particle size of 1 mm or more (hereinafter referred to as “large number of polymers”) N2 were counted separately. In order to make it easier to see the highly absorbent polymer that has fallen on the wire mesh 12, the wire mesh 12 may be illuminated from below.

The number of polymers indicates the susceptibility to polymer leakage, and the smaller the value, the less likely the highly absorbent polymer will damage the wrap sheet or top sheet, and the less likely it is that polymer leakage will occur (highly absorbent polymer is a laminate). It is hard to leak from). The number of small polymers N1 is usually 7 or less, preferably 5 or less, more preferably 4 or less, still more preferably 3 or less in each of the above three regions. The number of large polymers is usually 5 or less, preferably 3 or less, more preferably 2 or less, still more preferably 1 or less in each of the above three regions.

〔Evaluation results〕
The evaluation results by the above-mentioned evaluation method are shown in Table 2 below. In the small polymer number N1 and the large polymer number N2 shown in Table 2, the three values separated by slashes (/) correspond to the above-mentioned three regions. That is, of the three values described as the number of small polymers N1 and the number of large polymers N2, the value on the left side indicates the number of polymers in the region corresponding to the front body, and the value in the center indicates the number of polymers in the region corresponding to the lower crotch. The value on the right side indicates the number of polymers in the region corresponding to the back body.

As is clear from Table 2, the paper diapers of Examples 1 to 19 have a relatively high fixing rate as compared with the paper diapers of Comparative Examples 1 to 23, and the number of small polymers N1 and the number of large polymers N2 are both relatively high. There were few. More specifically, in all of Examples 1 to 19, the fixing rate is 89% or more, the number of small polymers N1 is 7 or less in all of the above-mentioned three regions, and the number of large polymers N2 is described above. The number was 5 or less in all three areas.

On the other hand, in Comparative Examples 1 to 15 in which the convex thickness T1 and the concave thickness T2 are both values within the above range, but at least one of the SAP amount and the pulp amount is a value outside the above range, the fixing rate is 89. Even if the retention rate was 89% or more, the number of small polymers N1 and the number of large polymers N2 were both 8 or more in at least one of the above-mentioned three regions. More specifically, in Comparative Examples 1 to 15 having a fixing rate of 89% or more, at least one of the small polymer number N1 and the large polymer number N2 is 14 or more in at least one of the above-mentioned three regions. Moreover, the number of small polymers N1 and the number of large polymers N2 were both 6 or more in all of the above-mentioned three regions. Further, among Comparative Examples 1 to 15, those in which the number of small polymers N1 and the number of large polymers N2 were both suppressed to 5 or less in all of the above-mentioned three regions did not reach 89%. Therefore, none of Comparative Examples 1 to 15 can achieve both the maintenance of the shape of the recess and the suppression of polymer leakage.

Further, even in Comparative Examples 16 to 23 in which at least one of the clearance CL and the press pressure P is a value outside the above range, although the SAP amount and the pulp amount are both values within the above range, the fixing rate is 89%. Even if there were some that did not meet the requirements and the fixing rate was 89% or more, the number of large polymers N2 was 6 or more in at least one of the above-mentioned three regions. In most of Comparative Examples 16 to 23 having a fixing rate of 89% or more (Comparative Examples 16 to 18), at least one of the small polymer number N1 and the large polymer number N2 is at least one of the above-mentioned three regions. The number was 12 or more, and the number of small polymers N1 and the number of large polymers N2 were both 8 or more in all of the above-mentioned three regions. Further, among Comparative Examples 16 to 23, those in which the large number of polymers N2 was suppressed to 5 or less in all of the above-mentioned three regions did not reach the retention rate of 89%. Therefore, none of Comparative Examples 16 to 23 can achieve both the maintenance of the shape of the recess and the suppression of polymer leakage.
From this result, it can be said that the disposable diapers of Examples 1 to 19 are superior in the shape-maintaining performance of the recesses and can suppress polymer leakage as compared with the disposable diapers of Comparative Examples 1 to 23.

2 Front body 3 Lower crotch 4 Back body 5 Front side flap 6 Rear side flap 10 Laminated 11 Acrylic board 12 Wire mesh 13 Mesh acrylic board 14 Container 15 Saline 20 Absorber 21 Absorbent core 22 Highly absorbent polymer 23 Fiber material 24 Wrap sheet 31 Top sheet 32 Back sheet 33 Side sheet 35 Cover sheet 38 Patch (front patch)
41-43 Gather 51-53 Thread rubber (stretchable member)
60 tape (fastening tape)
70 Recessed part 71 First inclined part 72 Second inclined part 73 Intersection part 81 Press roll (roll)
81a Convex part 82 Anvil roll (roll)
82a Outer peripheral surface 100 Paper diaper CL Clearance N1 Number of small polymers N2 Number of large polymers Nm Mean Nn NG Number Nt Number of sides to be measured P Press pressure (pressure)
T1 convex thickness T2 concave thickness

Claims (3)

The first step of coating an absorbent core containing a highly absorbent polymer and an elastic fiber material with a wrap sheet to obtain an absorber,
The second step of arranging a liquid-permeable top sheet on the surface of the absorber on the skin-facing surface side obtained in the first step to obtain a laminated body, and the second step.
The laminate obtained in the second step is passed between a pair of rolls to squeeze the absorber and the top sheet in the thickness direction, and the laminate is placed in one of the width directions of the laminate with respect to the longitudinal direction of the laminate. The recess of the laminated body has a concave portion having a linear first inclined portion that is inclined and a linear second inclined portion that is inclined to the other side in the width direction with respect to the longitudinal direction and intersects the first inclined portion. A third step of providing a groove-like and lattice-like shape on the skin-facing surface side is provided.
In the first step, the content of the highly absorbent polymer is set to 75 g / m ² or more and 300 g / m ² or less at the position corresponding to the recess of the absorbent core, and the content of the fiber material is set. Is 75 g / m ² or more and 250 g / m ² or less.
In the third step, the clearance between the rolls is 0.1 mm or more and 0.5 mm or less, and the pressure applied from the rolls to the laminate is 1.2 MPa or more and 2.0 MPa or less.
A method for manufacturing an absorbent article. In the third step, the clearance is set to 0.15 mm or more.
The method for producing an absorbent article according to claim 1. A fourth step of joining the absorbent core and the wrap sheet via a hot melt adhesive at a position corresponding to the recess is provided.
The method for producing an absorbent article according to claim 1 or 2.

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