CN109998788B

CN109998788B - Disposable diaper having a disposable diaper

Info

Publication number: CN109998788B
Application number: CN201811472341.3A
Authority: CN
Inventors: 芥川晃士; 佐佐木纯
Original assignee: Kao Corp
Current assignee: Kao Corp
Priority date: 2017-12-05
Filing date: 2018-12-04
Publication date: 2022-02-11
Anticipated expiration: 2038-12-04
Also published as: CN109998788A; JP2019097974A; JP7117098B2

Abstract

A plurality of non-gathering sections (5 (5A-5G)) of a core forming material are formed in the absorbent core (40). The length in the longitudinal direction (X) of each non-collecting section (5) is not more than 1/5 times the length in the longitudinal direction (X) of the absorbent body (4). The skin-side wrapping sheet (41) and the non-skin-side wrapping sheet (42) are joined to each other in at least one of the plurality of non-collecting sections (5). According to a predetermined method, when the regions I to V are set in the diaper (1), projected images formed by projecting all the non-collecting sections (5) present in the regions II and III in the lateral direction (Y) are continuous over the entire length of the regions II and III in the longitudinal direction (X).

Description

Disposable diaper having a disposable diaper

Technical Field

The present invention relates to a disposable diaper.

Background

Absorbent articles such as disposable diapers typically have a liquid-permeable front sheet, a liquid-impermeable back sheet, and an absorbent body disposed between the two sheets. As an absorbent body, a structure including a liquid-retentive absorbent core in which a core-forming material containing wood pulp, a water-absorbent polymer, or the like is gathered, and a water-permeable core-covering sheet covering the absorbent core is known. The core-spun sheet has the effects of ensuring the shape retention of the absorbent body, preventing the core-forming material from falling off, and the like.

In the disposable diaper, conventionally, for the purpose of improving fit, liquid absorbency, and the like, a through hole penetrating the absorbent core in the thickness direction or a low grammage portion having a lower grammage than the peripheral portion is provided in the absorbent core. For example, japanese patent application laid-open No. 2014-515981 describes that in order to improve the fit and liquid absorption properties of a disposable diaper, a groove substantially not containing an absorbent material is extended in the longitudinal direction (the direction corresponding to the front-rear direction of the wearer) in an absorbent core. Further, japanese patent application laid-open No. 2012-16435 describes: in order to improve the leakage resistance of urine and feces in a disposable diaper, the center portion in the transverse direction (direction perpendicular to the longitudinal direction) of the crotch portion of an absorbent core is formed as a high grammage portion, and both side portions in the transverse direction are formed as low grammage portions, and a central bending guide portion including slits, grooves, or non-collecting portions extending in the longitudinal direction is provided in the high grammage portion, and a side bending guide portion including non-collecting portions is provided in the low grammage portion.

Disclosure of Invention

A disposable diaper having a liquid-retentive absorbent member and a topsheet arranged on the skin-facing side of the absorbent member, the disposable diaper having a longitudinal direction extending from the abdomen side of a wearer to the back side via a crotch portion and a lateral direction perpendicular thereto, and further having a crotch portion arranged to face the crotch portion when worn, an abdomen-side portion arranged on the abdomen side of the wearer with respect to the crotch portion, and a back-side portion arranged on the back side of the wearer with respect to the crotch portion. The absorbent body includes: an absorbent core in which a core forming material containing an absorbent material is gathered; a skin-side wrapping sheet made of a nonwoven fabric covering the skin-facing surface of the absorbent core; and a non-skin-side wrapping sheet made of a nonwoven fabric covering the non-skin-facing surface of the absorbent core, wherein the absorbent body extends in the longitudinal direction from the stomach-side portion to the back-side portion across a longitudinal center line bisecting the diaper in the longitudinal direction in an unfolded and elongated state. A plurality of non-gathered sections of the core forming material are formed in the absorbent core, and the longitudinal length of each non-gathered section is 1/5 or less of the longitudinal length of the absorbent body. The skin-side wrapping sheet and the non-skin-side wrapping sheet are joined to each other in at least one of the plurality of non-collecting sections. When the regions I to V are set in the diaper, the projected images formed by projecting all the non-collecting sections present in the regions II and III in the lateral direction are continuous over the entire longitudinal length of the regions II and III.

< method for determining regions I to V >

In the diaper in the unfolded and stretched state, five imaginary straight lines parallel to a reference line are drawn at equal intervals at positions on the back side of the reference line with one imaginary straight line passing through the longitudinal end on the stomach side of the absorbent body and extending in the lateral direction as the reference line, and the interval between the imaginary straight lines is a value obtained by dividing the longitudinal length from the longitudinal center line to the longitudinal end on the stomach side of the absorbent body by 5 times. Five regions divided by the six virtual straight lines are set as a region I, a region II, a region III, a region IV, and a region V in order from the near side to the far side from the reference line.

Drawings

Fig. 1 is a partially cut-away plan view of a skin-facing surface side, which is a topsheet side, in an expanded state (expanded and stretched state) in which elastic members of respective portions are expanded in a flat state in an embodiment of a disposable diaper of the present invention.

Fig. 2 is a schematic cross-sectional view at line a-a of fig. 1.

Fig. 3 is a schematic plan view of the skin-facing side of the absorbent body of the diaper shown in fig. 1.

Fig. 4 is a schematic cross-sectional view at line B-B of fig. 3.

Fig. 5 corresponds to fig. 3, and shows another embodiment of the absorbent body of the present invention.

Fig. 6 corresponds to fig. 3, showing still another embodiment of the absorbent body of the present invention.

Fig. 7 is a schematic cross-sectional view of still another embodiment of the absorbent body of the present invention.

Detailed Description

In a disposable diaper, when an absorbent body is wet by absorbing an excreted liquid such as urine, the absorbent body is broken and divided into a plurality of pieces due to a decrease in strength and an increase in its own weight caused by the liquid absorption, and as a result, there is a problem that the liquid absorbability of the diaper is greatly reduced.

Accordingly, the present invention relates to a disposable diaper in which breakage of the absorbent body is less likely to occur.

< method for determining regions I to V >

In the diaper in the unfolded and stretched state, five imaginary straight lines parallel to a reference line are drawn at equal intervals at positions on the back side of the reference line, with one imaginary straight line passing through the longitudinal end on the stomach side of the absorbent body and extending in the lateral direction as the reference line. The distance between the virtual straight lines is 2 times the value obtained by dividing the longitudinal length from the longitudinal centerline to the longitudinal end on the ventral side of the absorbent body by 5. Five regions divided by the six virtual straight lines are set as a region I, a region II, a region III, a region IV, and a region V in order from the near side to the far side from the reference line.

According to the present invention, a disposable diaper in which breakage of the absorber is less likely to occur is provided.

Hereinafter, a disposable diaper according to the present invention will be described based on the preferred embodiment with reference to the drawings. Fig. 1 and 2 show a disposable diaper 1 according to the present embodiment. The diaper 1 has a longitudinal direction X extending from the stomach side of the wearer to the back side via the crotch portion and a transverse direction Y perpendicular thereto, and has a crotch portion M disposed in the crotch portion when worn, a stomach side portion F disposed on the stomach side of the wearer from the crotch portion M, and a back side portion R disposed on the back side of the wearer from the crotch portion M.

As shown in fig. 1, the diaper 1 has a longitudinal shape elongated in the longitudinal direction X, and has a longitudinal direction corresponding to the longitudinal direction X and a width direction corresponding to the lateral direction Y in a planar view in an unfolded and extended state. The diaper 1 has a hourglass shape in which, as shown in fig. 1 in a plan view, both side edges along the longitudinal direction X of the central portion in the longitudinal direction X including the crotch portion M are curved inward in an arc shape, and the central portion in the longitudinal direction X is narrowed inward. The crotch portion M includes a excretory part facing portion (urination point), not shown, disposed opposite to the excretory part such as the penis of the wearer when worn. The excretion portion-facing portion is usually slightly offset toward the abdomen-side portion F from the center portion in the longitudinal direction X of the diaper 1.

As shown in fig. 1 and 2, the diaper 1 has an absorbent body 4 having liquid retention properties, a liquid-permeable topsheet 2 disposed on the skin-facing surface side of the absorbent body 4 and contacting the skin of the wearer when worn, and a liquid-impermeable or water-repellent backsheet 3 disposed on the non-skin-facing surface side of the absorbent body 4. The absorbent body 4 is interposed between the two

sheets

2 and 3. The absorbent body 4 is formed into a vertically long shape that is long in the longitudinal direction X in plan view as shown in fig. 1, and extends in the longitudinal direction X from the stomach-side portion F to the back-side portion R across a longitudinal centerline CLx that bisects the extended and stretched diaper 1 in the longitudinal direction X.

In the present specification, the "skin-facing surface" refers to a surface of the absorbent article or a component thereof (e.g., the absorbent body 4) that faces the skin side of the wearer when the absorbent article is worn, i.e., a surface that is closer to the skin of the wearer, and the "non-skin-facing surface" refers to a surface of the absorbent article or a component thereof that faces the opposite side of the skin side when the absorbent article is worn, i.e., a surface that is farther from the skin of the wearer (the clothing side worn by the wearer). In the present specification, "worn" refers to a state in which a normal proper wearing position, that is, a proper wearing position of the absorbent article is maintained.

The front sheet 2 and the back sheet 3 each have a size larger than the absorbent body 4 and extend outward from the periphery of the absorbent body 4. The back sheet 3 forms the outer shape of the diaper 1 in an unfolded and stretched state as shown in fig. 1. As shown in fig. 2, the front sheet 2 and the back sheet 3 extend outward in the lateral direction Y from both side edges of the absorbent body 4 in the longitudinal direction X, and form side flaps together with side sheets 34 described later. The wing portions are portions of the diaper 1 which are formed by members extending outward in the lateral direction Y from the absorbent body 4. The front sheet 2 and the back sheet 3 are not particularly limited, and various materials currently used for such absorbent articles can be used. For example, various nonwoven fabrics, perforated films, and the like can be used as the front sheet 2, and a resin film, a laminate of a resin film, a nonwoven fabric, and the like can be used as the back sheet 3. The back sheet 3 may be, for example, a film sheet having liquid impermeability, alone, or an exterior sheet, for example, a nonwoven fabric, laminated on the outer surface side, which is the non-skin-facing surface of the film sheet.

Linear elastic members 31 are fixed in an extended state along the transverse direction Y between the front sheet 2 and the back sheet 3 at the end portions in the longitudinal direction X, which are the waist portions of the front and back side portions F and R, respectively, so that waist gathers are formed at the waist portions when the diaper 1 is worn by contraction of the elastic members 31. Further, side sheets (leakproof cuff forming sheets) 34 are disposed on both the left and right sides of the front sheet 2 side of the diaper 1 in the longitudinal direction X. The side sheet 34 has an inner edge portion extending in the longitudinal direction X and an outer edge portion extending in the transverse direction Y from a side edge of the absorbent body 4 extending in the longitudinal direction X outward in the transverse direction Y and joined to the back sheet 3, the inner edge portion overlapping the absorbent body 4 when viewed in plan as shown in fig. 1. A pair of leak-proof cuffs are formed by contraction of the elastic members 32 when the leg portions of the diaper 1 are worn, by fixing the linear elastic members 32 in an extended state along the longitudinal direction X between the side sheets 34 and the back sheet 3 of the left and right leg portions disposed around the legs of the wearer. Further, by fixing the linear elastic member 33 to the inner edge portion of the side sheet 34 in an extended state along the longitudinal direction X, a leakage prevention cuff is formed at least in the crotch portion M by contraction of the elastic member 33 when the diaper 1 is worn. The front sheet 2, the back sheet 3, the absorbent body 4, the

elastic members

31, 32, 33, and the side sheet 34 are joined to each other by a known joining method such as a hot melt adhesive.

The diaper 1 is a so-called open-type disposable diaper, and as shown in fig. 1, a pair of

fastener tapes

35, 35 are provided on both side edge portions (the side flap portions) of the back portion R of the diaper 1 in the longitudinal direction X. A fixing portion, not shown, formed of a male surface member for mechanical surface fastening is attached to the fastener tape 35. In addition, a region to be fixed 36 composed of a female member mechanically fastened is formed on the non-skin-facing surface of the stomach-side portion F of the diaper 1. The fixed region 36 is formed by joining and fixing female members fastened to the surface of the back sheet 3 on the non-skin-facing surface of the abdomen-side portion F by a known joining method such as adhesive or heat sealing, and detachably fixes the fixed portion of the fastener tape 35. When the diaper 1 is worn, the side flap portions of the back side portion R are pulled toward the abdomen side of the wearer, and the

fastening tapes

35, 35 provided on the side flaps are fixed to the fixed regions 36 on the outer surface of the abdomen side portion F.

Fig. 3 shows the skin-facing surface side of the absorbent body 4. The absorbent body 4 includes: an absorbent core 40 having liquid retention properties; a skin-side wrapping sheet 41 covering the skin-facing surface of the absorbent core 40; and a non-skin-side wrapping sheet 42 covering the non-skin-facing surface of the absorbent core 40. The absorbent core 40 and the core-wrapped

sheets

41 and 42 are joined to each other by a known joining method such as a hot-melt adhesive. In the present embodiment, the absorbent core 40 has a single-layer structure and is formed in a vertically long shape that is long in the longitudinal direction X in a plan view, as shown in fig. 3.

The absorbent core 40 is formed by gathering a core-forming material containing an absorbent material. The absorbent material is not particularly limited, and materials generally used as a material for forming such an absorbent core can be used, and examples thereof include a fibrous material (preferably hydrophilic fibers) such as wood pulp, synthetic fibers treated with a hydrophilic agent, and a water-absorbent polymer. The absorbent core 40 is an aggregate of fibrous materials or a structure in which a particulate water-absorbent polymer is supported in the aggregate.

The skin-side wrapping sheet 41 and the non-skin-side wrapping sheet 42 may be 1) one continuous sheet, or 2) separate sheets. As an example of the aspect of 1) above, the following aspects can be cited: one continuous core-covering sheet having a width 2 to 3 times the length (width) in the transverse direction Y of the absorbent core 40 covers the entire skin-facing surface of the absorbent core 40, extends outward in the transverse direction Y from both side edges of the absorbent core 40 in the longitudinal direction X, and is folded down below the absorbent core 40 to cover the entire non-skin-facing surface of the absorbent core 40. In the one core sheet, the portion covering the skin-facing surface of the absorbent core 40 is the skin-side wrapping sheet 41, and the portion covering the non-skin-facing surface of the absorbent core 40 is the non-skin-side wrapping sheet 42.

In the case of 2) above, the skin-side wrapping chip 41 and the non-skin-side wrapping chip 42 may be the same in length, i.e., width, in the lateral direction Y or may be different. In the case where the widths of the two

sheets

41, 42 are different, either one may be longer. For example, the skin-side wrapping sheet 41 has the same width as the maximum width of the skin-facing surface of the absorbent core 40, that is, has a size capable of covering the entire area of the skin-facing surface of the absorbent core 40, and the non-skin-side wrapping sheet 42 can be formed to be wider than the width of the sheet 41. The wide non-skin-side wrapping sheet 42 covers the entire non-skin-facing surface of the absorbent core 40 and extends outward in the width direction Y from both side edges of the absorbent core 40 along the longitudinal direction X, and the extended portions may be wound around the skin-side wrapping sheet 41 disposed to face the skin-facing surface of the absorbent core 40 to cover both side edges of the sheet 41 along the longitudinal direction X.

As the

core sheets

41 and 42, a liquid-permeable sheet can be used, and for example, paper or nonwoven fabric can be exemplified. However, the two

sheets

41 and 42 are preferably nonwoven fabrics from the viewpoint of reliably preventing the

core sheets

41 and 42 from being damaged and reliably joining the two

sheets

41 and 42 to each other in the non-collecting section 5 described later. The nonwoven fabric has a higher strength than paper, is less likely to be broken during processing, and can flexibly cope with deformation of the absorbent core due to swelling of the water-absorbent polymer particles when the water-absorbent polymer particles are used as a core-forming material constituting the absorbent core. The nonwoven fabric is not particularly limited, and nonwoven fabrics produced by various production methods can be used. The nonwoven fabric is preferably a hydrophilic nonwoven fabric comprising synthetic fibers subjected to hydrophilization treatment.

The thickness of the absorbent core 40 (the thickness of the portion other than the non-collecting section 5 described later) is preferably 2mm or more, more preferably 3mm or more, and preferably 10mm or less, and more preferably 8mm or less.

The absorbent core 40 preferably has a grammage (grammage of the portion other than the non-collecting section 5 described later) of 150g/m²The above is more preferably 200g/m²Above, and preferably 700g/m²Hereinafter, more preferably 600g/m²The following.

The grammage of the core sheets 41 and 42 (the grammage of the portion other than the non-collecting section 5 described later) is preferably 3g/m²Above, more preferably 5g/m²Above, and preferably 20g/m²Hereinafter, more preferably 30g/m²The following.

The thickness of the diaper 1 or the constituent members (absorbent core 40, topsheet 2, etc.) of the diaper 1 is measured by the following method.

< method for measuring thickness of disposable diaper or its component part >

The measurement object was left standing at a horizontal position without wrinkles or bends, and the measurement was carried out at 5cN/cm²The thickness of the object to be measured under load. Specifically, for the measurement of the thickness, for example, a thickness gauge ABS electronic indicator ID-U1025 (manufactured by Mitutoyo Corporation) was used. At this time, a load of 5cN/cm is placed between the distal end of the thickness gauge and the cut-out object to be measured²In the above-described embodiment, the thickness of a circular or square plate (a propylene plate having a thickness of about 5 mm) in a plan view is measured. The thickness measurement was performed at 10 points, and the average value was calculated as the thickness of the object to be measured.

The absorbent core 40 is provided with a plurality of non-collecting sections indicated by reference numerals 5(5A to 5G) in the drawing. In the figure, the plurality of non-collecting sections 5 formed in the absorbent core 40 are denoted by reference numerals 5A to 5G in order from the near side to the far side from the longitudinal end (front end) 4F on the side of the stomach-side section F of the absorbent body 4, with the non-collecting section 5A being closest to the front end 4F and the non-collecting section 5G being farthest from the front end 4F. The non-collecting sections 5A to 5G are pairs of two non-collecting sections 5, and 7 pairs of 14 non-collecting sections 5 are formed in the absorbent core 40. The following description of the non-collecting sections 5 applies to all of the non-collecting sections 5A to 5G formed in the absorbent core 40 unless otherwise specified.

The non-collecting section 5 is a section constituting the absorbent core 40 in which a core forming material containing an absorbent material such as a fiber material or a water-absorbent polymer is not collected, and i) the grammage of the core forming material of the non-collecting section 5 is substantially zero or ii) is smaller than the other regions of the absorbent core 40. In the case of i) above, the non-collecting section 5 can be said to be a through hole penetrating the absorbent core 40 in the thickness direction. In both cases i) and ii), the non-collecting section 5 functions as a liquid guiding path for the excreted liquid such as urine, and has a function of diffusing the excreted liquid in the extending direction (in the present embodiment, the vertical direction X). Therefore, regardless of the arrangement of the non-collecting section 5, the liquid discharged can be uniformly absorbed by the entire absorbent core 40.

In the diaper 1, as will be described later, the skin-side wrapping sheet 41 and the non-skin-side wrapping sheet 42 are joined to at least one of the plurality of non-collecting sections 5 formed in the absorbent core 40, and the above-described i) is applied to the non-collecting section 5 where the two

sheets

41 and 42 are joined, and the grammage of the core-forming material is substantially zero. The "grammage" referred to herein is substantially zero, and includes a mode in which the core-forming material is not intentionally mixed in, or the like, and a very small amount of the core-forming material is present in the non-aggregated portion 5, but the amount of the core-forming material is such as not to inhibit the joining of the two

sheets

41 and 42.

On the other hand, in the non-collecting section 5 where the two

sheets

41 and 42 are not joined, the above-described i) and ii) may be applied. The grammage of the non-aggregated portion 5 consisting of a small number of aggregated portions to which the above ii) applies is preferably 300g/m²Hereinafter, it is more preferably 250g/m²The following. When the non-collecting portion 5 is such a small number of collecting portions, the joining of the two

sheets

41 and 42 is not normally performed in the non-collecting portion 5. In consideration of the liquid diffusing effect and the like, the through-hole mode is preferable to the mode of the small amount of the collecting part as the non-collecting part 5 in which the two

sheets

41 and 42 are not joined.

The non-collecting section 5 (non-collecting section including through holes) is a section formed by intentionally inhibiting the collection of the core forming material in the step of collecting the core forming material during the production of the absorbent core 40. The absorbent core 40 having the non-collecting section 5 can be manufactured by a conventionally known method for manufacturing an absorbent core. Specifically, for example, in a method of obtaining the absorbent core 40 by sucking and stacking a core forming material (absorbent material) supplied by an air flow onto a forming die formed on the outer peripheral surface of a rotary drum using a fiber stacking device, the absorbent core is produced by using a forming die having a predetermined pattern, for example, a forming die in which a portion corresponding to the non-collecting section 5 protrudes upward from the peripheral portion, as the forming die. In the absorbent core 40 obtained by this method, the portion where the core forming material is not present is the non-gather portion 5. As another method for producing the absorbent core 40 having the non-collecting section 5, a method may be employed in which an absorbent core having no non-collecting section 5 is produced, and a post-process such as a mold release process or a cutting process is performed on a predetermined portion of the absorbent core to form the non-collecting section 5. The absorbent core having the "non-collecting section 5 composed of a small number of collecting sections" can also be produced by the above-described method.

In the present invention, as shown in fig. 2, the skin-side wrapping sheet 41 and the non-skin-side wrapping sheet 42 need to be joined to at least one of the plurality of non-collecting sections 5 formed in the absorbent core 40. In this regard, in the present embodiment, the two

sheets

41 and 42 are joined not only to the non-collecting section 5C shown in fig. 2 but also to all of the plurality of non-collecting sections 5A to 5G formed in the absorbent core 40.

As described above, since the skin-side wrapping sheet 41 and the non-skin-side wrapping sheet 42 are joined to the non-collecting section 5, the adhesiveness between the absorbent core 40 and the two

sheets

41 and 42 is improved, the shape retention of the absorbent core 40 interposed between the two

sheets

41 and 42 is improved, and even if an absorbent material such as water-absorbent polymer particles included in the core-forming material constituting the absorbent core 40 swells due to absorption of excreted liquid such as urine, the degree of deformation of the absorbent core 40 can be suppressed. Further, according to this configuration, since the movement of the absorbent body 4 can be restrained in cooperation with the skin-side wrapping sheet 41 bonded to the front sheet 2 with an adhesive and the non-skin-side wrapping sheet 42 bonded to the back sheet 3 with an adhesive, the absorbent body 4 is less likely to move relative to the front sheet 2 and the back sheet 3 when the diaper 1 is worn. Therefore, the absorbent body 4 (absorbent core 40) is less likely to break during use of the diaper 1, and can stably exhibit excellent absorption performance. In addition, according to this configuration, the absorption of the excretory fluid into the absorbent core 40 can be improved, and the sinking of the non-collecting section 5 due to swelling of the absorbent material contained in the core-forming material can be effectively prevented.

The method of joining the two

sheets

41 and 42 in the non-collecting section 5 is not particularly limited, and for example, an adhesive such as a hot-melt adhesive or a known joining method such as fusion welding can be used. The joint portion of the two

sheets

41 and 42 in the non-collecting section 5 can be formed, for example, as follows. That is, after an adhesive such as a hot-melt adhesive is applied in advance to a position corresponding to the non-collecting section 5 of at least one of the two

sheets

41 and 42, and the absorbent core 40 is covered with the two

sheets

41 and 42 to obtain the absorbent body 4, the non-collecting section 5 of the absorbent body 4 is pressed from the skin-facing surface and/or the non-skin-facing surface side, and one or both of the two

sheets

41 and 42 are pressed in, whereby the two

sheets

41 and 42 can be joined to each other at the non-collecting section 5. The pressing treatment may be a known embossing process such as embossing with or without heat or ultrasonic embossing. When the pressing treatment is a heat and pressure treatment such as embossing with heat, for example, the two

sheets

41 and 42 are heat-pressed against each other, and therefore the two

sheets

41 and 42 are firmly bonded to each other in accordance with the adhesive force of the adhesive.

In particular, when the core-spun

sheets

41 and 42 are nonwoven fabrics made of fibers containing polypropylene (PP) resin, particularly nonwoven fabrics made of PP alone, the joining of the two

sheets

41 and 42 in the non-aggregated portion 5 can be performed by pressing the

sheets

41 and 42 without using an adhesive or melting treatment of resin such as heat or ultrasonic waves, and sufficient joining strength can be obtained at the joined portion of the two

sheets

41 and 42, which is advantageous in terms of processing suitability, manufacturing cost, and the like.

In the present embodiment, as representatively shown in fig. 2 for the non-collecting section 5C, since the joined portion of the two

sheets

41 and 42 of the non-collecting section 5 is located at the central portion in the thickness direction of the absorbent body 4, each of the two

sheets

41 and 42 is recessed in a concave shape at the formation position of the non-collecting section 5. Such a form of the joined portion of the two

sheets

41 and 42 is obtained by simultaneously pressing the two

sheets

41 and 42 at the formation position of the non-collecting section 5 in the above-described method of forming the joined portion. The position of the joint between the two

sheets

41 and 42 of the non-collecting section 5 may be offset not to the center in the thickness direction of the absorbent body 4, but to the skin-facing surface side, i.e., the topsheet 2 side, or to the non-skin-facing surface side, i.e., the backsheet 3 side. In the former case, the skin-side wrapping sheet 41 is flat, but the non-skin-side wrapping sheet 42 is recessed in a concave shape at the formation position of the non-collecting section 5. In the latter case, the non-skin-side wrapping sheet 42 is flat, but the skin-side wrapping sheet 41 is recessed in a concave shape at the formation position of the non-collecting section 5.

In the non-aggregated portion 5, the two

sheets

41 and 42 may be bonded to each other at least in a part of the non-aggregated portion 5, or may not be bonded to the entire area of the non-aggregated portion 5, but from the viewpoint of stably achieving the effect of the non-aggregated portion 5, the "ratio of the area of the bonded portion of the two

sheets

41 and 42 to the area of the non-aggregated portion 5" (the bonded portion occupancy ratio) is preferably 70% or more, more preferably 80% or more, and preferably 100%. In the present embodiment, the non-collecting section 5 is formed in a shape elongated in one direction (longitudinal direction X), specifically, in a rectangular shape in plan view, as shown in fig. 1 and 3, and the joint portions of the two

pieces

41 and 42 are continuous over the entire length in the longitudinal direction X, which is the longitudinal direction, of the rectangular non-collecting section 5. The term "total length" as used herein means the total length of the non-concentrated portion 5 in the longitudinal direction X and the length based on the total length, and specifically means 90% or more of the total length of the non-concentrated portion 5.

From the viewpoint of the balance between the operational effect achieved by the non-collecting sections 5 and the absorption performance of the absorbent core 40, the length in the longitudinal direction X of the plurality of non-collecting sections 5(5A to 5G) formed in the absorbent core 40 is 1/5 or less, preferably 1/6 or less, and more preferably 1/7 or less of the length in the longitudinal direction X of the absorbent body 4.

The diaper 1 is characterized by the arrangement pattern of the plurality of non-collecting sections 5(5A to 5G) of the absorbent core 40. That is, according to the following < method of determining regions I to V >, when regions I to V are set in diaper 1, projected images formed by projecting all of non-collecting sections 5 existing in regions II and III in the lateral direction Y are continued over the entire length of regions II and III in the longitudinal direction X. In other words, when an imaginary straight line (not shown) is arbitrarily drawn in the regions II and III in parallel with the lateral direction Y, the non-collecting portion 5 is always present on the imaginary straight line. The above-mentioned "existing in the regions II and III" includes not only the case where the entire non-aggregated portion 5 exists in the regions II and III as in the

non-aggregated portions

5D and 5E, but also the case where only a part of the non-aggregated portion 5 exists in the regions II and III as in the

non-aggregated portions

5B, 5C, and 5F. In the present embodiment, as shown in fig. 3, a plurality of non-condensed portions 5, specifically, 5 pairs of 10 non-condensed portions 5B to 5F are present in the regions II and III, and all projected images formed by the 10 non-condensed portions 5B to 5F when projected in the lateral direction Y are connected to each other to form one continuous projected image in the longitudinal X-direction longitudinal-cutting regions II and III.

< method for determining regions I to V >

In the diaper 1 in the developed and extended state (see fig. 1), as shown in fig. 3, five virtual straight lines V2 to V6 parallel to the reference line V1 are drawn at equal intervals Sx at a position on the back side R side of the reference line V1 with one virtual straight line passing through the longitudinal end (front end) 4F on the stomach side F side of the absorbent body 4 and extending in the lateral direction Y as the reference line V1. The interval Sx between the virtual straight lines V1 to V6 is a value 2 times a value obtained by dividing the longitudinal length Lx of the tip 4F of the absorbent body 4 by 5 from the longitudinal centerline CLx bisecting the diaper 1 in the extended and stretched state in the longitudinal direction X. Five regions defined by the six virtual straight lines V1 to V6 are region I, region II, region III, region IV, and region V in order from the near side to the far side from the reference line V1.

The regions I to V identified by the above-described identification method are mainly used for identifying the positions of the non-collecting sections 5 in the absorbent body 4 (absorbent core 40), and therefore the virtual straight lines V1 to V6 that divide these regions are appropriately set based on the size (length in the longitudinal direction X) of the absorbent body 4. However, in the present invention, as described above, the virtual straight lines V1 to V6 are set based on the longitudinal centerline CLx bisecting the diaper 1 in the longitudinal direction X, based on the length in the longitudinal direction X of the diaper 1 in the extended state, not based on the absorbent body 4. The reason for this is that the position of the non-collecting section 5 should be determined based on the absorption site of excretory fluid such as urine in the absorbent body 4 when the diaper 1 is worn, and the absorption site cannot be determined only by the size of the absorbent body 4, and it is necessary to consider the position of the absorbent body 4 in the diaper 1 and the like. If the absorbent body is normally disposed at the longitudinal center of the diaper in an unfolded and stretched state, it is considered that there is almost no problem even if the virtual straight lines V1 to V6 are set based on the longitudinal length of the absorbent body, but the disposition position of the absorbent body in the diaper is various, and for example, in the diaper 1, the absorbent body 4 may be distributed in a biased manner on the side of the abdomen side portion F of the diaper 1. At this time, since the center of the absorbent body 4 in the longitudinal direction X does not coincide with the center of the diaper 1 in the unfolded and stretched state, even if the regions I to V are determined based on the length of the absorbent body 4 in the longitudinal direction X, the regions thus determined cannot be reflected on the portions of the absorbent body 4 that actually absorb the excretory fluid, and as a result, it becomes difficult to form the non-collecting sections 5 at appropriate positions. Therefore, in the present invention, the regions I to V are determined by setting virtual straight lines V1 to V6 based on the longitudinal length of the disposable diaper in an unfolded and extended state.

In the above determination method, "the longitudinal end (front end) 4F of the absorbent body 4" through which the reference line V1 passes is the longitudinal end closest to the waist end 1F on the side of the abdomen side portion F of the diaper 1 among the constituent members of the absorbent body 4. Therefore, for example, when the

core sheets

41, 42 extend from the longitudinal end (front end) of the absorbent core 40 on the stomach side portion F side toward the waist end 1F side, the front end of the extension of the two

sheets

41, 42 from the front end of the absorbent core 40 is the front end 4F of the absorbent body 4. In the present embodiment, since the lengths in the longitudinal direction X of all the constituent members of the absorbent body 4, that is, the absorbent core 40, the skin-side wrapping sheet 41, and the non-skin-side wrapping sheet 42 are the same, the front end 4F of the absorbent body 4 coincides with the longitudinal end (front end) of each of the three constituent members on the side of the abdomen side portion F.

In the present embodiment, as shown in fig. 3, the length of the absorbent body 4 in the longitudinal direction X is the same as the length of the regions I to V in the longitudinal direction X, and the absorbent body 4 is divided into the regions I to V in the longitudinal direction X by five. However, the absorbent body 4 is not limited to this, and the present invention includes embodiments in which the length of the absorbent body 4 in the longitudinal direction X is different from the length of the regions I to V in the longitudinal direction X. Specifically, there are enumerated 1) a mode in which the length in the longitudinal direction X of the absorbent body 4 is shorter than the length in the longitudinal direction X of the regions I to V, that is, a mode in which the longitudinal end (rear end) 4R on the back side portion R side of the absorbent body 4 is positioned closer to the front end 4F of the absorbent body 4 than the virtual straight line V6; 2) the length in the longitudinal direction X of the absorbent body 4 is longer than the length in the longitudinal direction X of the regions I to V, that is, the rear end 4R of the absorbent body 4 is located farther from the front end 4F of the absorbent body 4 than the virtual straight line V6. In a typical example of the absorber 4 (absorbent core 40) of the form 1) described above, the rear end 4R of the absorber 4 is located between the virtual straight lines V5 and V6 or between the virtual straight lines V4 and V5.

In the present embodiment, the non-collecting sections 5(5A to 5G) are each formed in a rectangular shape when the absorbent body 4 is viewed in plan view, as shown in fig. 3, and the longitudinal direction thereof coincides with the longitudinal direction X. The non-collecting sections 5A to 5G are each a pair of 2 and 1 group of non-collecting sections 5, and 7 to 14 non-collecting sections 5 are formed in the absorbent core 40. All of the plurality of non-collecting sections 5A to 5G formed in the absorbent core 40 are formed symmetrically about a transverse center line CLy that bisects the absorbent body 4 (the diaper 1 in an unfolded and stretched state) in the transverse direction Y and extends in the longitudinal direction X. The non-collecting portion 5 is not formed on the transverse center line CLy.

When the diaper 1 is worn, the absorbent body 4 is normally sandwiched between the thighs of the wearer in the regions II and III, and therefore the absorbent core 40 forming the main body of the absorbent body 4 is easily damaged by external forces caused by the movement of the wearer in the regions II and III. In particular, when the absorbent core 40 is wet when absorbing an excreted liquid such as urine and the strength is reduced and the weight is increased as compared with the dry state, the absorbent core 40 is more likely to break and may be divided into a plurality of pieces by an external force. In contrast, in the diaper 1, as described above, the projected images formed when all the non-collecting sections 5B to 5F present in the regions II and III are projected in the lateral direction Y are continuous over the entire length in the longitudinal direction X of the regions II and III, that is, the non-collecting sections 5B to 5F are arranged so that part or all of the projected images in the lateral direction Y of the plurality of non-collecting sections 5B to 5F are continuously connected to each other in the longitudinal direction X, and the regions II and III are longitudinally penetrated in the longitudinal direction X, and the skin-side wrapping sheet 41 and the non-skin-side wrapping sheet 42 are joined to each of the non-collecting sections 5B to 5F, so that the absorbent core 40 is firmly restrained by the two

sheets

41 and 42 at a plurality of the regions II and III (10 positions in the present embodiment), and therefore, the breakage of the absorbent core 40 is not easily caused even in a wet state.

In the present invention, the skin-side wraparound sheet 41 and the non-skin-side wraparound sheet 42 need not be joined to all of the plurality of non-collecting sections 5(5A to 5G) formed in the absorbent core 40, but from the viewpoint of further reliably achieving the effect of preventing the breakage of the absorbent core 40 at the joint portions of the two

sheets

41, 42 of the above-described non-collecting sections 5, it is preferable that the two

sheets

41, 42 are joined to all of the plurality of non-collecting sections 5 present in the regions II and III, and it is more preferable that the two

sheets

41, 42 are joined to all of the plurality of non-collecting sections 5 formed in the absorbent core 40.

In general, the regions II and III of a disposable diaper are regions where the excretion portion-facing portion (excretion point) which is a portion that first receives excretion liquid such as urine excreted by a wearer is present, and the absorption body utilization ratio (the ratio of a portion actually used for liquid absorption to the entire absorption body) is particularly high compared to other regions because of concentration of excretion liquid. On the other hand, the utilization rate of the absorber is low in the regions other than the regions II and III, and the absorption performance of the absorber is not fully utilized. When the absorbent body is difficult to absorb uniformly and the utilization rate of the absorbent body is low, the absorbent body after liquid absorption is accompanied by a significant mixture of swollen portions resulting from liquid absorption and non-swollen portions not absorbing liquid, and as a result, the absorbent body after liquid absorption has a level difference irregularly formed on the skin-facing surface thereof, and the skin-facing surface is uneven, which causes a problem such as deterioration in wearing feeling. On the other hand, in the diaper 1, as described above, the absorbent body 4 in the regions II and III has a plurality of non-collecting sections 5 (specifically, the non-collecting sections 5B to 5F) functioning as liquid guiding paths for the excreted liquid such as urine, and the plurality of non-collecting sections 5 (the non-collecting sections 5B to 5F) are arranged so that projected images formed by projecting all of the sections 5B to 5F in the lateral direction Y are continuous over the entire length in the longitudinal direction X of the regions II and III, and therefore the excreted liquid present in the regions II and III is easily diffused in the extending direction (the longitudinal direction X in the present embodiment) thereof through the non-collecting sections 5. Therefore, uniform absorption by the absorbent body 4 can be achieved in the diaper 1, and improvement in the utilization efficiency of the absorbent body can be expected.

In particular, in the present embodiment, since each of the plurality of non-collecting sections 5A to 5G formed in the absorbent core 40 extends continuously in one direction, specifically, in the longitudinal direction X, the diffusibility of the discharged liquid in the longitudinal direction X is excellent, and the utilization efficiency of the absorbent body is high. The term "continuously extending" as used herein includes not only a mode in which the non-collecting portions are continuously arranged in one direction without interruption, but also a mode in which a plurality of small non-collecting portions having a short length in one direction are intermittently arranged at a small interval (preferably 5mm or less) in the one direction.

From the viewpoint of more reliably preventing the above-described action effects of the non-collecting sections 5 (prevention of breakage of the absorbent body, improvement of uniform absorbency, etc.), it is preferable that the non-collecting section (maximum width non-collecting section) formed in all the non-collecting sections 5(5A to 5G) of the absorbent core 40 and having the longest length (width) in the lateral direction Y be present in the region II or III. In the present embodiment, the maximum width non-collecting portion is the non-collecting portion 5D, and the non-collecting portion 5D exists across the regions II and III as shown in fig. 3, and exists in both the regions II and III.

From the same viewpoint, it is preferable that the non-collecting section having the longest length in the longitudinal direction X (maximum length non-collecting section) among all the non-collecting sections 5(5A to 5G) formed in the absorbent core 40 is present in the region II or III. In the present embodiment, the non-aggregated portions 5B to 5F present in the regions II and III are longer in the longitudinal direction X than the

non-aggregated portions

5A and 5G not present in the regions II and III, and therefore the non-aggregated portions 5B to 5F include the maximum length non-aggregated portion, so that the present embodiment has the preferred configuration.

The shape of the non-concentrated portions 5 in plan view is not limited to the rectangular shape of the non-concentrated portions 5A to 5G shown in fig. 3, and may be, for example, a circular shape, an oval shape, a parallelogram shape, a rhombus shape, a polygonal shape of a pentagon or more, and the like, but from the viewpoint of preventing the absorbent body 4 from being broken, the longitudinal shape shown in fig. 3, that is, the shape in which the length in the longitudinal direction X is longer than the length in the lateral direction Y is preferable. For example, when the shape of the absorbent body 4 in a plan view is an oval or a rhombus, the major axis direction of the oval or rhombus preferably coincides with the longitudinal direction X.

The size of the non-concentrated portion 5, particularly the size in a plan view, can be appropriately adjusted so that the action and effect of the non-concentrated portion 5 (prevention of breakage of the absorbent body 4, improvement of uniform absorbency, and the like) can be sufficiently exhibited, and attention should be paid to the adjustment of the size of the non-concentrated portion 5. That is, since the non-aggregated portion 5 is a portion where the core-forming material is substantially absent, for example, when the absorbent body 4 is viewed from the outside before use of the diaper 1, the absorbent body 4 is broken at the formation position of the non-aggregated portion 5, and some observers may have a question about the performance mainly realized by the absorbent body 4, such as liquid absorbency. Therefore, it is desirable that the non-collecting section 5 is as inconspicuous as possible within the range in which the above-described operation and effect are achieved. Here, in the diaper 1, "the ratio of the area of the joined portion of the two

sheets

41 and 42 to the area of the non-concentrated portion 5" (the ratio of the joined portion) is preferably as high as possible, and is preferably 100%.

From the viewpoint of the expression of the predetermined action and effect of the non-aggregated portion 5 and the balance of making the non-aggregated portion 5 inconspicuous, the length in the longitudinal direction X of the non-aggregated portion 5 is preferably 20mm or more, more preferably 30mm or more, and preferably 70mm or less, more preferably 50mm or less. The length in the longitudinal direction X of the "maximum length non-collecting section" present in the region II or III is preferably within the above-mentioned specific range.

From the viewpoint of avoiding the absorbent body 4 from being divided, the length (width) of the non-collecting section 5 in the lateral direction Y is preferably 5mm or less. From the viewpoint of balance between the expression of the predetermined action and effect of the non-aggregated portions 5 and the inconspicuous presence of the non-aggregated portions 5, the width of the non-aggregated portions 5 is preferably 0.5mm or more, more preferably 1mm or more, and preferably 5mm or less, more preferably 3mm or less. The width of the "maximum width non-collecting part" existing in the region II or III is preferably within the above-mentioned specific range. The "width" (length in the lateral direction Y) of the non-collecting portion 5 referred to herein means the maximum width when the width is not constant in the longitudinal direction X. Similarly, the width of the non-collecting section 5 is the maximum width when the width is different between the skin-facing surface and the non-skin-facing surface of the absorbent body 4.

Further, the regions II and III are regions where breakage of the absorbent core 4 is particularly likely to occur, and therefore, it is preferable that a large number of non-collecting sections 5 for preventing breakage of the absorbent core 40 be present in the regions II and III. From this viewpoint, the total number of the non-aggregated portions 5 present in the regions II and III is preferably larger than the total number of the non-aggregated portions 5 present in the regions I and IV, and this preferred embodiment is shown in fig. 3. From the viewpoint of preventing the absorbent body 4 from breaking and the non-aggregated portions 5 from having an insignificant balance, the total number of the non-aggregated portions 5 present in the regions II and III is preferably 3 pairs or more, more preferably 5 pairs or more, and preferably 100 pairs or less, more preferably 50 pairs or less.

From the same viewpoint, it is preferable that the total area S1 of the non-aggregated portions 5 existing in the regions II and III is larger than the total area S2 of the non-aggregated portions 5 existing in the regions I and IV. The total areas S1 and S2 indicate the total of the areas of the non-collecting sections 5 on the skin-facing surface of the absorbent body 4 (the skin-facing surface of the skin-side wrapping sheet 41). The ratio of the total area S1 to the total area S2 is based on the premise that the total area S1 > the total area S2, and the total area S1/the total area S2 is preferably 1.2 or more, more preferably 1.5 or more, and preferably 10 or less, and more preferably 5 or less.

In addition, although the excretory part-facing portion (urination point) is present in the regions II and III, at least one of the plurality of non-collecting sections 5 formed in the absorbent core 40 is preferably present across the regions II and III from the viewpoint of improving the shape retention of the excretory part-facing portion and the absorbent core 40 in the vicinity thereof and more reliably preventing the breakage of the absorbent body 4. In the present embodiment, as shown in fig. 3, 2 non-collecting sections 5D of 1 pair span the boundary between the region II and the region III (virtual straight line V3), which is a preferable mode.

In order to more reliably prevent the absorbent body 4 from being broken, the non-collecting sections 5 are preferably provided on both sides of the transverse direction Y of the transverse center line CLy that bisects the absorbent body 4 in the transverse direction Y and extends in the longitudinal direction X. In particular, in the regions II and III where the absorbent body 4 is likely to break, the non-aggregated portions 5 are preferably present on both sides of the transverse direction Y of the transverse centerline CLy in this manner. In the present embodiment, as shown in fig. 3, it is preferable that all of the plurality of non-collecting sections 5A to 5G formed in the absorbent core 40 are formed symmetrically about the horizontal center line CLy as the axis of symmetry. The transverse centerline CLy of the present embodiment bisects not only the absorbent member 4 but also the diaper 1 in the transverse direction Y. As in the present embodiment, the non-concentrated portion 5 is formed symmetrically with respect to the lateral centerline CLy, which is advantageous in preventing the absorbent body 4 from being broken and achieving uniform absorption, compared to the case where the non-concentrated portion 5 is formed asymmetrically on both sides of the lateral centerline CLy in the lateral direction Y.

The region V is the region farthest from the regions II and III where the excretion portion-facing portion (urination point) is present, and is a portion where the absorbent body utilization rate is low, and therefore breakage of the absorbent body 4 is unlikely to occur. Therefore, in the present embodiment, as shown in fig. 3, the non-collecting section 5 is not present in the region V.

Fig. 4 shows a non-collected portion 5E which is a part of the plurality of non-collected portions 5 in the absorbent body 4 shown in fig. 3 and a cross section along the lateral direction Y in the vicinity thereof. In the present embodiment, as shown in fig. 4, the absorbent body 4 has gradation regions 4G on both sides of the non-gathered portion 5 (the joint portion of the core sheets 41 and 42) in the lateral direction Y, in which the grammage of the absorbent body 4 (the absorbent core 40) gradually increases as going outward (away from the non-gathered portion 5) in the lateral direction Y from the non-gathered portion 5. The gradation region 4G is adjacent to the non-collecting portion 5 and exists along the entire length of the side edge of the non-collecting portion 5 in the longitudinal direction X. The gradation region 4G does not reach both ends (both side edges along the longitudinal direction X) of the absorbent body 4 in the lateral direction Y, and is sandwiched between the non-collecting section 5 and a region of the absorbent body 4 having a constant grammage. When the absorbent body 4 has such a gradation region 4G, an effect can be expected in which the presence of the non-aggregated portion 5 is not noticeable. The gradation region 4G may be formed in the vicinity of all of the plurality of non-collecting sections 5(5A to 5G) formed in the absorbent core 40, or the gradation region 4G may be formed only in the vicinity of a part of the plurality of non-collecting sections 5.

From the viewpoint of more reliably realizing the operation and effect of gradation region 4G, it is preferable that length (width) 4GW (see fig. 4) in lateral direction Y of gradation region 4G is longer than length (width) 5W (see fig. 4) in lateral direction Y of non-collecting section 5, and it is particularly preferable that width 4GW is larger than a value 2 times width 5W, that is, a magnitude relation of "4 GW > (5W × 2)" is established. The ratio of the width 4GW and the width 5W is based on the premise that the width 4GW > the width 5W, and the width 4 GW/the width 5W is preferably 0.7 or more, more preferably 1 or more, and preferably 20 or less, and more preferably 10 or less.

In addition, the non-collecting part 5 is not obvious as much as possibleFrom the viewpoint of (2), the front sheet 2 located in the region where the non-aggregated portion 5 is present is preferably a high grammage and thick sheet so that the recessed portion formed corresponding to the non-aggregated portion 5 where the core forming material is not aggregated can be filled and the non-aggregated portion 5 can be hidden visually. Specifically, the topsheet 2 positioned in the region where the non-aggregated portion 5 is present preferably has a grammage of 30g/m²Above, it is more preferably 35g/m²The thickness is preferably 1mm or more, and more preferably 1.2mm or more. In the present embodiment, since the non-collecting sections 5 are present in the regions I to IV as shown in fig. 3, the topsheet 2 preferably has such a high grammage and a large thickness at least in the regions I to IV, or may have such a high grammage and a large thickness in the entirety of the topsheet 2 including the region V. The upper limit of the grammage and thickness of the topsheet 2 positioned in the region where the non-collecting section 5 is present is preferably 70g/m in terms of the grammage, for example, from the viewpoint of providing the topsheet 2 with practically sufficient strength²Hereinafter, it is more preferably 50g/m²Hereinafter, the thickness is preferably 5mm or less, and more preferably 3mm or less. The front sheet 2 may be formed of one sheet, or may have a multi-sheet laminated structure in which a plurality of sheets are formed by being superposed. From the viewpoint of making the non-collecting section 5 unnoticeable and from the viewpoint of cost, the front sheet 2 is preferably a nonwoven fabric having a laminate structure of two sheets and having a three-dimensional uneven structure on at least one surface (skin-facing surface).

Hereinafter, another embodiment of the present invention will be described with reference to the drawings. In the other embodiments described later, the description will be mainly given of the different components from the diaper 1 (absorbent body 4), and the same components are given the same reference numerals and the description thereof will be omitted. In particular, the description of the diaper 1 (absorbent body 4) applies appropriately to the structural parts not described.

The absorbent body 4A shown in fig. 5 is different from the absorbent body 4 shown in fig. 3 in that a plurality of non-collecting sections 5(5A to 5G) formed in the absorbent core 40 are not formed symmetrically about the horizontal center line CLy as a symmetry axis. As shown in fig. 5, the absorbent body 4A is formed such that 5 non-concentrated portions 5B to 5F are present in the regions II and III, and projected images formed by projecting the 5 non-concentrated portions 5B to 5F in the lateral direction Y are continuous over the entire length in the longitudinal direction X of the regions II and III, whereby the absorbent body 4A can achieve the same effects as those of the absorbent body 4 having the same configuration.

The absorbent body 4B shown in fig. 6 is different from the absorbent body 4A shown in fig. 5 in the shape of the non-aggregated portion 5 in a plan view. In the absorbent body 4B, the non-collecting sections 5A to 5G have a circular or elliptical shape in plan view. The absorbent body 4B can also achieve the same effects as those of the absorbent bodies 4 and 4A.

In the absorbent body 4C shown in fig. 7, the length (width) of the non-collecting section 5 in the lateral direction Y gradually increases from the skin-facing surface 43 toward the non-skin-facing surface 44 of the absorbent body 4C. In other words, the length (width) of the non-collecting section 5 in the lateral direction Y gradually decreases from the non-skin-facing surface 44 toward the skin-facing surface 43 of the absorbent body 4C. Therefore, in the absorbent body 4C, the width of the skin-facing surface 43 differs from that of the non-skin-facing surface 44 in the non-collecting section 5, and a magnitude relationship "width Wa at the skin-facing surface 43 < width Wb at the non-skin-facing surface 44" holds.

In the absorbent core 4C in which the above-described magnitude relationship holds with respect to the length (width) of the non-collecting section 5 in the lateral direction Y, the absorbent core 40 has a constant width section 40A having a constant width in the thickness direction and a tapered section 40B having a width gradually decreasing from the skin-facing surface 43 toward the non-skin-facing surface 44 as shown in fig. 7, and the tapered section 40B and the non-collecting section 5 are adjacent to each other in the lateral direction Y.

In general, when the skin-facing surface 43 of the absorbent body 4B is a surface that is easy to be externally observed compared to the non-skin-facing surface 44, and the width Wa of the non-collecting section 5 on the skin-facing surface 43 is too large, the impression that the absorbent body 4C is divided at the formation position of the non-collecting section 5 is strong for a person who observes the skin-facing surface of the diaper in an unused state, and therefore, the observer is questioned about the performance of the absorbent body 4C, such as liquid absorbency, which is mainly achieved, and the reliability of the diaper is lowered. On the other hand, if the width Wa of the non-collecting section 5 is made too small in order to avoid this, the joining force between the core-covering

sheets

41 and 42 of the non-collecting section 5 is reduced, and this reduces the shape retention of the absorbent core 40 particularly in a wet state, and the above-described operational effects of the non-collecting section 5 cannot be sufficiently achieved. On the other hand, in the absorbent body 4C, since the magnitude relationship of "the width Wa on the skin-facing surface 43 < the width Wb on the non-skin-facing surface 44" is established in the non-collecting portion 5 as described above, the presence of the non-collecting portion 5 is not obvious when the skin-facing surface (topsheet 2 side) of the diaper 1 is observed, and the two

sheets

41 and 42 are firmly joined to each other in the non-collecting portion 5, thereby stably achieving the predetermined effect of the non-collecting portion 5.

When the relationship of "width Wa at the skin-facing surface 43 < width Wb at the non-skin-facing surface 44" in the non-collecting portion 5 is satisfied, the thickness of the joint portion between the skin-side wrapping sheet 41 and the non-skin-side wrapping sheet 42 of the non-collecting portion 5 gradually increases from the central portion of the non-collecting portion 5 in the lateral direction Y toward the outer side in the lateral direction Y in the cross-sectional view along the lateral direction Y as shown in fig. 7. When the joint portion of the two

sheets

41 and 42 in the non-collecting section 5 has a structure (arch structure) in which the thickness of the central portion in the lateral direction Y is relatively thin and the thickness of both side portions is relatively thick, the resistance of the joint portion itself to external force is improved, thereby improving the shape retention of the absorbent core 40.

From the viewpoint of more reliably achieving the effect of the joint of the arch structure of the two

pieces

41, 42, when the thickness of the joint at the center of the non-integrated portion 5 in the lateral direction Y is T1 and the thickness of the joint at the end of the non-integrated portion 5 in the lateral direction Y is T2, it is preferable that the thickness T1 < the thickness T2.

In the absorbent core 40, when a fibrous material such as wood pulp and a water-absorbent polymer (water-absorbent polymer particles) are contained as a core-forming material (absorbent material), the content mass ratio of the fibrous material to the water-absorbent polymer (mass of the fibrous material/mass of the water-absorbent polymer) in the tapered portion 40B is preferably lower than the content mass ratio in the wide portion 40A. That is, the tapered portion 40B preferably contains a smaller amount of the water-absorbent polymer than the constant width portion 40A. When the tapered portion 40B adjacent to the non-collecting portion 5 in the lateral direction Y contains a large amount of a water-absorbent polymer having a swelling degree larger than that of the fiber material due to liquid absorption, the tapered portion 40B swells largely after absorption of excretion liquid such as urine, and therefore the width and shape of the non-collecting portion 5 change largely, which hinders the expression of the predetermined effect of the non-collecting portion 5, and as described above, the relationship of the size of "tapered portion 40B < constant width portion 40A" holds with respect to the content mass ratio of the fiber material to the water-absorbent polymer, whereby swelling of the tapered portion 40B after liquid absorption can be suppressed, and this fear can be eliminated.

The absorbent core 40 having the constant width portion 40A and the tapered portion 40B can be manufactured based on a conventionally known absorbent core manufacturing method using a fiber stacking device. Specifically, for example, in a method of obtaining the absorbent core 40 by sucking and accumulating the fiber material and the water-absorbent polymer particles supplied in the air flow onto a forming die formed on the outer peripheral surface of the rotary drum using a fiber accumulating device, the forming die can be manufactured by using a forming die formed in a shape in which a portion corresponding to the non-accumulating portion 5 protrudes upward compared to the peripheral portion and the width of the portion gradually decreases as the portion goes upward (a reverse tapered shape opposite to the direction of decreasing the width of the tapered portion 40B). Further, since the water-absorbent polymer particles contained in the tapered portion 40B are more likely to fall off than the constant width portion 40A, even if a special process for establishing the above-described size relationship of "(the content mass ratio of the fiber material to the water-absorbent polymer in the constant width portion 40A) > (the content mass ratio of the fiber material to the water-absorbent polymer in the tapered portion 40B)" is not performed at the time of manufacturing the absorbent core 40, if the absorbent core 40 in which the water-absorbent polymer particles are uniformly distributed as a whole is manufactured as in a usual method, a large amount of the water-absorbent polymer particles fall off from the tapered portion 40B from the time after manufacturing to the time of using the absorbent core 40, that is, at the time of wearing the diaper 1, the size relationship is established.

The gradation region 4G (see fig. 4) of the absorbent body 4 is formed by compressing the absorbent core 40 having the tapered section 40B in the thickness direction of the absorbent core 40. The absorbent core 40 having the gradation region 4G thus formed deforms the tapered portion 40B by this compression, and its tapered shape is deformed, so that the tapered portion 40B does not exist.

The present invention has been described above, but the present invention is not limited to the above-described embodiments and can be modified as appropriate. The disposable diaper of the present invention is not limited to the open-type disposable diaper of the above-described embodiment, and can be applied to various diapers for absorbing body fluids, for example, a pants-type disposable diaper. A pants-type disposable diaper typically includes an absorbent body having liquid retention properties, a topsheet disposed on a skin-facing surface side of the absorbent body, and an outer covering disposed on a non-skin-facing surface side of the absorbent body, and has a pair of side seals, a waist opening, and a pair of leg openings formed by joining together both side edges of the outer covering in the longitudinal direction in each of a front side portion and a back side portion. The embodiments of the present invention described above are further described below.

< 1 > a disposable diaper having a liquid-retentive absorbent member and a topsheet arranged on the skin-facing surface side of the absorbent member, having a longitudinal direction extending from the abdomen side to the back side of a wearer through a crotch part and a lateral direction perpendicular thereto, and having a crotch part arranged to face the crotch part when worn, an abdomen part arranged on the abdomen side of the wearer than the crotch part and a back part arranged on the back side of the wearer than the crotch part,

the absorbent body includes: an absorbent core in which a core forming material containing an absorbent material is gathered; a skin-side wrapping sheet made of a nonwoven fabric covering the skin-facing surface of the absorbent core; and a non-skin-side wrapping sheet made of nonwoven fabric covering the non-skin-facing surface of the absorbent core, wherein the absorbent body extends in the longitudinal direction from the stomach-side portion to the back-side portion across a longitudinal center line bisecting the diaper in the longitudinal direction in an unfolded and elongated state,

a plurality of non-gathered sections of the core forming material are formed in the absorbent core, the longitudinal length of each non-gathered section is 1/5 or less of the longitudinal length of the absorbent body,

the skin-side wrapping sheet and the non-skin-side wrapping sheet are joined to each other in at least one of the plurality of non-collecting sections,

when the regions I to V are set in the diaper, projected images formed by projecting all the non-collecting sections present in the regions II and III in the lateral direction are continued over the entire longitudinal length of the regions II and III,

< method for determining regions I to V >

In the diaper in the unfolded and stretched state, five imaginary straight lines parallel to a reference line are drawn at equal intervals at positions closer to the back side than the reference line, with one imaginary straight line passing through the longitudinal end on the stomach side of the absorbent body and extending in the lateral direction as the reference line, the interval between the imaginary straight lines being a value obtained by dividing the longitudinal length from the longitudinal center line to the longitudinal end on the stomach side of the absorbent body by 5 times, and five regions divided by the six imaginary straight lines are referred to as a region I, a region II, a region III, a region IV, and a region V in order from the near side to the far side from the reference line.

< 2 > the disposable diaper according to the above < 1 >, wherein at least one, preferably all, of the plurality of non-collecting sections are through holes penetrating the absorbent core in a thickness direction.

< 3 > the disposable diaper according to the above < 1 > or < 2 >, wherein the longitudinal length of the plurality of non-aggregated portions is preferably 1/6 or less, more preferably 1/7 or less, with respect to the longitudinal length of the absorbent body.

< 4 > the disposable diaper according to any one of the above < 1 > to < 3 >, wherein in at least one of preferably all of the plurality of non-collecting sections, a ratio of an area of a joint between the skin-side core sheet and the non-skin-side core sheet to an area of the non-collecting section, that is, a joint occupancy rate, is preferably 70% or more, more preferably 80% or more, and still more preferably 100%.

< 5 > the disposable diaper according to any one of the above < 1 > to < 4 >, wherein the non-aggregated portion formed in all the non-aggregated portions of the absorbent core and having the longest lateral length is present in the region II or III.

< 6 > the disposable diaper according to any one of the above < 1 > to < 5 >, wherein the non-aggregated portion formed in all the non-aggregated portions of the absorbent core and having the longest longitudinal length is present in the region II or III.

< 7 > the disposable diaper according to any one of the above < 1 > -6 >, wherein the longitudinal length of the non-collecting section including the non-collecting section having the longest longitudinal length (maximum length non-collecting section) among the plurality of non-collecting sections is preferably 20mm or more, more preferably 30mm or more, and preferably 70mm or less, more preferably 50mm or less.

< 8 > the disposable diaper according to any one of the above < 1 > to < 7 >, wherein the transverse length of the non-collecting section including the non-collecting section having the longest transverse length (maximum width non-collecting section) among the plurality of non-collecting sections is preferably 0.5mm or more, more preferably 1mm or more, and preferably 5mm or less, and more preferably 3mm or less.

< 9 > the disposable diaper according to any one of the above < 1 > -to < 8 >, wherein the total number of the non-aggregated portions existing in the regions II and III is larger than the total number of the non-aggregated portions in the regions I and IV.

< 10 > the disposable diaper according to any one of the above < 1 > -9 >, wherein the total number of the non-collecting sections present in the regions II and III is preferably 3 pairs or more, more preferably 5 pairs or more, and preferably 100 pairs or less, more preferably 50 pairs or less.

< 11 > the disposable diaper according to any one of the above < 1 > -10 >, wherein a total area (S1) of the non-collecting sections existing in the regions II and III is larger than a total area (S2) of the non-collecting sections in the regions I and IV.

< 12 > the disposable diaper according to any one of the above < 1 > -11 >, wherein a ratio of a total area of the non-aggregated portions present in the regions II and III (S1) to a total area of the non-aggregated portions present in the regions I and IV (S2) is from the former (S1) > the latter (S2), and the former (S1)/the latter (S2) is preferably 1.2 or more, more preferably 1.5 or more, and preferably 10 or less, and more preferably 5 or less.

< 13 > the disposable diaper according to any one of the above < 1 > -12 >, wherein at least one of the plurality of non-collecting sections is present so as to straddle the regions II and III.

< 14 > the disposable diaper according to any one of the above < 1 > to < 13 >, wherein the non-aggregated portions are respectively present on both sides in the lateral direction of a lateral centerline that bisects the absorbent body in the lateral direction and extends in the longitudinal direction.

< 15 > the disposable diaper according to the above < 14 >, wherein in the regions II and III, the non-aggregated portions are present on both sides of the transverse center line in the transverse direction, respectively.

< 16 > the disposable diaper according to any one of the above < 1 > to < 15 >, wherein the non-aggregated portion is formed symmetrically with a transverse center line bisecting the absorbent body in the transverse direction and extending in the longitudinal direction as a symmetry axis.

< 17 > the disposable diaper according to any one of the above < 1 > to < 16 >, wherein the non-aggregated portion is absent in the region V.

< 18 > the disposable diaper according to any one of the above < 1 > to < 17 >, wherein the skin-side wrapping sheet and the non-skin-side wrapping sheet are joined in all of the non-collecting sections formed in the absorbent core.

< 19 > the disposable diaper according to any one of the above < 1 > to < 18 >, wherein the absorbent body has, on both sides of the non-aggregated portion in the lateral direction, gradation regions in which the thickness of the absorbent body gradually increases as going from the non-aggregated portion to the lateral outside.

< 20 > the disposable diaper according to the above < 19 >, wherein the lateral length of the gradation region is longer than the lateral length of the non-collecting section.

< 21 > the disposable diaper according to the above < 19 > or < 20 >, wherein the ratio of the lateral length of the gradation region to the lateral length of the non-collecting section is on the premise that the former > the latter, and the former/the latter is preferably 0.7 or more, more preferably 1 or more, and preferably 20 or less, and more preferably 10 or less.

< 22 > the disposable diaper according to any one of the above < 1 > to < 21 >In the cloth, the grammage of the front sheet in the region where the non-collecting portion exists is preferably 30g/m²Above, it is more preferably 35g/m²Above, and preferably 70g/m²Hereinafter, it is more preferably 50g/m²The following.

< 23 > the disposable diaper according to any one of the above < 1 > -to < 22 >, wherein a thickness of the topsheet located in a region where the non-aggregated portion exists is preferably 1mm or more, more preferably 1.2mm or more, and preferably 5mm or less, and more preferably 3mm or less.

< 24 > the disposable diaper according to any one of the above < 1 > to < 23 >, wherein in at least one preferable whole portion of the non-collecting section, a lateral length of the non-collecting section gradually increases as going from the skin-facing surface to the non-skin-facing surface of the absorbent body.

< 25 > the disposable diaper according to any one of the above < 1 > to < 24 >, wherein the absorbent core has: a constant width portion having a constant lateral length in the thickness direction of the absorbent core; and a tapered portion having a lateral length gradually decreasing from the skin-facing surface to the non-skin-facing surface of the absorbent core (the absorbent body), the tapered portion and the non-collecting portion being adjacent in the lateral direction,

in the absorbent core, the absorbent material includes a fiber material and a water-absorbent polymer, and a mass ratio of the fiber material to the water-absorbent polymer in the tapered portion, that is, a mass of the fiber material/a mass of the water-absorbent polymer, is lower than the mass ratio in the constant width portion.

< 26 > the disposable diaper according to any one of the above < 1 > -25 >, wherein the thickness of the portion other than the non-collecting section in the absorbent core is preferably 2mm or more, more preferably 3mm or more, and preferably 10mm or less, more preferably 8mm or less.

< 27 > the disposable diaper according to any one of the above < 1 > to < 26 >, wherein the grammage of the portion of the absorbent core other than the non-collecting section is preferably 150g/m²The above is more preferably 200g/m²Above, and preferably 700g/m²Hereinafter, more preferably 600g/m²The following.

Claims

1. A disposable diaper having a liquid-retentive absorbent member and a topsheet disposed on a skin-facing surface side of the absorbent member, the disposable diaper having a longitudinal direction extending from an abdomen side to a back side of a wearer through a crotch portion and a lateral direction perpendicular thereto, and further having a crotch portion disposed to face the crotch portion when worn, an abdomen side portion disposed on the abdomen side of the wearer with respect to the crotch portion, and a back side portion disposed on the back side of the wearer with respect to the crotch portion, the disposable diaper characterized in that:

the skin-side wrapping chip and the non-skin-side wrapping chip are joined in all the non-collecting sections,

when the regions I to V are set in the diaper, a projected image formed by projecting all the non-collecting sections present in the regions II and III in the lateral direction is continuous over the entire longitudinal length of the regions II and III,

< method for determining regions I to V >

In the diaper in the unfolded and stretched state, five imaginary straight lines parallel to a reference line are drawn at equal intervals at positions closer to the back side than the reference line, with one imaginary straight line passing through the longitudinal end on the stomach side of the absorbent body and extending in the lateral direction as the reference line, the interval between the imaginary straight lines being a value obtained by dividing the longitudinal length from the longitudinal center line to the longitudinal end on the stomach side of the absorbent body by 5 times, and five regions divided by six imaginary straight lines are referred to as a region I, a region II, a region III, a region IV, and a region V in order from the near side to the far side from the reference line.

2. The disposable diaper according to claim 1, characterized in that:

at least one of the non-collecting sections is a through hole penetrating the absorbent core in the thickness direction.

3. The disposable diaper according to claim 1 or 2, characterized in that:

the longitudinal length of the plurality of non-collecting sections is 1/6 or less with respect to the longitudinal length of the absorbent body.

4. The disposable diaper according to claim 1 or 2, characterized in that:

in at least one of the plurality of non-collecting sections, a ratio of an area of a joint between the skin-side wrapping sheet and the non-skin-side wrapping sheet to an area of the non-collecting section, that is, a joint occupancy rate is 70% or more.

5. The disposable diaper according to claim 1 or 2, characterized in that:

the non-gathering section having the longest transverse length is present in the region II or III among all the non-gathering sections formed in the absorbent core.

6. The disposable diaper according to claim 1 or 2, characterized in that:

the non-gathering section having the longest longitudinal length is present in the region II or III among all the non-gathering sections formed in the absorbent core.

7. The disposable diaper according to claim 1 or 2, characterized in that:

the non-collecting section, including the one having the longest longitudinal length, of the plurality of non-collecting sections has a longitudinal length of 20mm to 70 mm.

8. The disposable diaper according to claim 1 or 2, characterized in that:

the non-collecting section, including the one having the longest transverse length, of the plurality of non-collecting sections has a transverse length of 0.5mm to 5 mm.

9. The disposable diaper according to claim 1 or 2, characterized in that:

the total number of the non-aggregated portions existing in the regions II and III is larger than the total number of the non-aggregated portions of the regions I and IV.

10. The disposable diaper according to claim 1 or 2, characterized in that:

the total number of the non-aggregated portions existing in the regions II and III is 3 pairs or more and 100 pairs or less.

11. The disposable diaper according to claim 1 or 2, characterized in that:

the total area of the non-aggregated portions present in the regions II and III is larger than the total area of the non-aggregated portions of the regions I and IV.

12. The disposable diaper according to claim 1 or 2, characterized in that:

the ratio of the total area of the non-aggregated portions present in the regions II and III to the total area of the non-aggregated portions present in the regions I and IV is 1.2 or more and 10 or less on the premise that the former > the latter.

13. The disposable diaper according to claim 1 or 2, characterized in that:

at least one of the plurality of non-aggregated portions is present so as to span the regions II and III.

14. The disposable diaper according to claim 1 or 2, characterized in that:

the non-gather portions are respectively present on both lateral sides of a transverse center line that bisects the absorbent body in the lateral direction and extends in the longitudinal direction.

15. The disposable diaper of claim 14, wherein:

in the regions II and III, the non-nesting portions are present on the lateral sides of the transverse centerline, respectively.

16. The disposable diaper according to claim 1 or 2, characterized in that:

the non-collecting section is formed symmetrically with respect to a transverse center line which bisects the absorbent body in the transverse direction and extends in the longitudinal direction as a symmetry axis.

17. The disposable diaper according to claim 1 or 2, characterized in that:

the non-collecting portion is not present in the region V.

18. The disposable diaper according to claim 1 or 2, characterized in that:

the absorbent body has, on both sides of the non-collecting section in the lateral direction, gradation regions in which the thickness of the absorbent body gradually increases as going from the non-collecting section to the lateral outside.

19. The disposable diaper of claim 18, wherein:

the lateral length of the gradation region is longer than the lateral length of the non-gather portion.

20. The disposable diaper of claim 18, wherein:

the ratio of the lateral length of the gradation region to the lateral length of the non-collecting section is 0.7 to 20, provided that the former is greater than the latter.

21. The disposable diaper according to claim 1 or 2, characterized in that:

the grammage of the front sheet in the region where the non-collecting part is present is 30g/m²Above and 70g/m²The following.

22. The disposable diaper according to claim 1 or 2, characterized in that:

the thickness of the front surface sheet in the region where the non-collecting section is present is 1mm to 5 mm.

23. The disposable diaper according to claim 1 or 2, characterized in that:

in at least one of the non-collecting portions, a lateral length of the non-collecting portion gradually increases as it goes from the skin-facing surface to the non-skin-facing surface of the absorbent body.

24. The disposable diaper according to claim 1 or 2, characterized in that:

the absorbent core has: a constant width portion having a constant lateral length in the thickness direction of the absorbent core; and a tapered portion having a lateral length gradually decreasing from the skin-facing surface to the non-skin-facing surface of the absorbent core, the tapered portion and the non-gathering portion being adjacent in a lateral direction,

in the absorbent core, the absorbent material includes a fiber material and a water-absorbent polymer, and a content mass ratio of the fiber material to the water-absorbent polymer in the tapered portion is lower than that in the constant width portion.

25. The disposable diaper according to claim 1 or 2, characterized in that:

the thickness of the absorbent core other than the non-collecting section is 2mm to 10 mm.

26. The disposable diaper according to claim 1 or 2, characterized in that:

the absorbent core has a grammage of 150g/m at a portion other than the non-gathering portion²Above and 700g/m²The following.