阅读说明：本技术 吸收性物品 (Absorbent article ) 是由 石桥京子 福田优子 于 2019-10-30 设计创作，主要内容包括：一种吸收性物品,包括吸收体(12)和保持吸收体(12)的外装体(13),其中,外装体(13)包括：配置在穿着者的肌肤侧上的内层片(131)；配置在非肌肤侧上的外层片(132)；以及配置在内层片(131)与外层片(132)之间的吸湿片(133)。内层片(131)和外层片(132)是热塑性纤维片或热塑性纤维复合片。吸湿片(133)包含纤维素纤维。吸湿片(133)的纤维取向配置在与正交于内层片(131)的纤维取向的方向不同的方向上。吸湿片(133)的一部分具有结合至内层片(131)与外层片(132)中的至少一者的结合部。(An absorbent article comprising an absorbent body (12) and an exterior body (13) that holds the absorbent body (12), wherein the exterior body (13) comprises: an inner layer sheet (131) disposed on the skin side of the wearer; an outer layer sheet (132) disposed on the non-skin side; and a moisture-absorbing sheet (133) disposed between the inner sheet (131) and the outer sheet (132). The inner layer sheet (131) and the outer layer sheet (132) are thermoplastic fiber sheets or thermoplastic fiber composite sheets. The absorbent sheet (133) contains cellulose fibers. The fiber orientation of the absorbent sheet (133) is arranged in a direction different from the direction orthogonal to the fiber orientation of the inner sheet (131). A part of the absorbent sheet (133) has a bonded part bonded to at least one of the inner sheet (131) and the outer sheet (132).)

1. An absorbent article comprising:

an absorbent body; and

an outer package holding the absorbent body, wherein,

the exterior body includes: an inner layer sheet disposed on the skin side of a wearer; an outer sheet disposed on the non-skin side; and a moisture-absorbing sheet disposed between the inner sheet and the outer sheet,

the inner layer sheet and the outer layer sheet are thermoplastic fiber sheets or thermoplastic fiber composite sheets,

the absorbent sheet contains cellulosic fibers,

the fiber orientation of the absorbent sheet is arranged in a direction different from a direction orthogonal to the fiber orientation of the inner sheet, and

a portion of the absorbent sheet has a bond to at least one of the inner sheet and the outer sheet.

2. The absorbent article of claim 1,

the absorbent sheet has a fiber orientation that differs by 30 ° or more from a direction orthogonal to the fiber orientation of the inner sheet.

3. The absorbent article according to claim 1 or 2, wherein,

the inner sheet has a hydrophilicity higher than that of the outer sheet and lower than that of the absorbent sheet.

4. The absorbent article of any one of claims 1-3, further comprising an elastomer between the inner ply and the outer ply.

5. The absorbent article according to any one of claims 1 to 4, wherein,

the absorbent sheet is a sheet subjected to a creping treatment or a stretching treatment.

6. The absorbent article according to any one of claims 1 to 5, wherein,

the absorbent sheet is bonded to the inner sheet or the outer sheet by a hot melt adhesive.

7. The absorbent article according to any one of claims 1 to 6, wherein,

a part of the absorbent sheet is bonded to the inner sheet, the number of the bonded portions is two or more, and the absorbent sheet bonded to the inner sheet is configured to be separated from the inner sheet upon absorption of moisture.

8. The absorbent article according to any one of claims 1 to 7, wherein,

the absorbent sheet is a sheet subjected to a creping process or a stretching process, and is provided with a bonding portion in the direction of the creping process or the stretching process.

9. The absorbent article according to any one of claims 1 to 8, wherein,

at least one of the inner ply and the outer ply is an elastic ply.

10. The absorbent article of claim 9,

the absorbent sheet is a creped sheet, and the crepe ratio of the absorbent sheet is 2% or more.

11. An absorbent article comprising:

an absorbent body; and

an outer package holding the absorbent body, wherein,

the exterior body includes: an inner layer sheet located on the skin side of the wearer; an outer sheet located on the non-skin side; and a moisture-absorbing sheet disposed between the inner sheet and the outer sheet,

the inner layer sheet and the outer layer sheet are thermoplastic fiber sheets or thermoplastic fiber composite sheets,

the absorbent sheet contains cellulosic fibers,

the fiber orientation of the absorbent sheet is arranged in a direction different from a direction orthogonal to the fiber orientation of the inner sheet, and

at least a part of the absorbent sheet is bonded to the outer cover so as to be separated from the inner sheet by swelling in the fiber orientation direction due to moisture absorption.

12. The absorbent article of claim 11,

the absorbent sheet is configured to have the same fiber orientation direction as the fiber orientation direction of the inner sheet and the outer sheet.

13. The absorbent article of claim 11,

the absorbent sheet is configured to have a fiber orientation different from the fiber orientation direction of the inner sheet and the outer sheet.

14. The absorbent article according to any one of claims 11 to 13, wherein,

the absorbent sheet is bonded to each of the inner sheet and the outer sheet by bonds.

15. The absorbent article of claim 14,

the bonded portion between the absorbent sheet and the inner sheet faces the bonded portion between the absorbent sheet and the outer sheet with the absorbent sheet interposed therebetween.

16. The absorbent article according to claim 14 or 15, wherein,

the bonding portion has a discontinuous shape.

17. The absorbent article of claim 16,

the bonded portion has a dot shape and is arranged along the fiber orientation direction of the absorbent sheet.

18. The absorbent article of claim 16,

the bonded portion has a linear shape and is provided in a direction orthogonal to the fiber orientation direction of the absorbent sheet.

19. The absorbent article of claim 18,

the pitch of the bonding portions is 2mm to 20 mm.

20. The absorbent article of claim 18 or 19,

the width of the joint is 0.1mm to 5 mm.

21. The absorbent article according to any one of claims 18 to 20, wherein,

the distance between two adjacent joint portions is 0.5mm to 18 mm.

22. The absorbent article according to any one of claims 11 to 21, wherein,

the thermoplastic fiber composite sheet is a composite sheet of one or more thermoplastic fiber sheets and other materials.

23. The absorbent article according to any one of claims 11 to 21, wherein,

the moisture-absorbing sheet has a tear strength of 200cN/25mm or less as measured by JISP-8113.

24. The absorbent article according to any one of claims 11 to 23,

the absorbent sheet has a crepe ratio of 2% to 40%.

25. The absorbent article according to any one of claims 11 to 24,

the contact angle of the inner layer sheet is 50 degrees or more and 130 degrees or less.

26. The absorbent article according to any one of claims 11 to 25, wherein,

the contact angle of the outer layer sheet is 90 degrees or more and 180 degrees or less.

27. The absorbent article according to any one of claims 11 to 26, wherein,

the contact angle of the moisture-absorbing sheet is 5 degrees or more and 70 degrees or less.

28. The absorbent article according to any one of claims 11 to 27, wherein,

the difference between the contact angle of the moisture-absorbing sheet and the contact angle of the inner layer sheet is 30 degrees or more and 90 degrees or less.

29. The absorbent article according to any one of claims 11 to 28,

the difference between the contact angle of the inner layer sheet and the contact angle of the outer layer sheet is 5 degrees or more and 90 degrees or less.

30. The absorbent article of any one of claims 11-29, further comprising an elastomer between the inner ply and the outer ply.

31. The absorbent article of claim 30, wherein,

the elastomer is a rubber thread.

32. The absorbent article according to any one of claims 11 to 31, wherein,

the elastic body is disposed between the inner sheet and the absorbent sheet.

33. The absorbent article according to any one of claims 29 to 32, wherein,

the absorbent sheet is bonded to a rubber thread by a hot melt adhesive and bonded to the inner ply by the rubber thread.

34. The absorbent article according to any one of claims 11 to 33, wherein,

the absorbent sheet is bonded to the outer sheet at least one point.

35. The absorbent article of claim 34,

the bonded portions between the absorbent sheet and the outer sheet are arranged according to a predetermined pattern.

36. The absorbent article of claim 34 or 35, wherein,

the bonded portion between the absorbent sheet and the outer sheet is formed of a hot melt adhesive.

37. The absorbent article according to any one of claims 11 to 36,

the outer sheet is hydrophobic.

38. The absorbent article according to any one of claims 11 to 37,

the inner layer sheet and the outer layer sheet are spun-bonded nonwoven fabrics.

39. The absorbent article according to any one of claims 11 to 38, wherein,

the inner layer sheet and the outer layer sheet are breathable non-woven fabrics.

Technical Field

The present invention relates to an absorbent article.

Background

An absorbent article such as a disposable diaper includes an absorber that absorbs excrement and an exterior body that holds the absorber at a predetermined position of a wearer. In order to prevent leakage of excrement and at the same time reduce stickiness and heat rash caused by sweat, an exterior body has a configuration in many cases in which a moisture-absorbing sheet is provided on the skin side of a wearer or sandwiched between an inner sheet provided on the skin side of the wearer and an outer sheet provided on the non-skin side (patent document 1).

Documents of the prior art

Patent document

Patent document 1: international publication WO2016/093371

Disclosure of Invention

Technical problem to be solved by the invention

In the conventional exterior body, an inner layer sheet is interposed between the skin of the wearer and the absorbent sheet to prevent the absorbent sheet from directly contacting the skin. However, since there is no gap between the absorbent sheet and the inner sheet or the skin after actual absorption of moisture, the inner sheet, the absorbent sheet, and the outer sheet adhere to the skin of the wearer. Therefore, hygroscopicity cannot be sufficiently exhibited, and problems such as adhesion still remain.

In view of the above, an object of the present invention is to provide an absorbent article which reduces stuffiness in a diaper due to perspiration or the like and does not give a feeling of stickiness to the skin of a wearer.

Technical scheme for solving technical problem

That is, the present invention is an absorbent article including an absorbent body and an outer covering that holds the absorbent body, wherein the outer covering includes an inner layer sheet provided on a skin side of a wearer, an outer layer sheet provided on a non-skin side, and an absorbent sheet provided between the inner layer sheet and the outer layer sheet, the inner layer sheet and the outer layer sheet are thermoplastic fiber sheets or thermoplastic fiber composite sheets, the absorbent sheet includes cellulose fibers, a fiber orientation of the absorbent sheet is provided in a direction different from a direction orthogonal to the fiber orientation of the inner layer sheet, and a part of the absorbent sheet has a bonding portion that is bonded to at least one of the inner layer sheet and the outer layer sheet.

Effects of the invention

The absorbent article of the present invention can form a space at least between the inner sheet and the absorbent sheet when absorbing moisture. Therefore, it is possible to provide an absorbent article which can reduce stuffiness in a diaper due to perspiration or the like and can reduce a sticky feeling on the skin of a wearer.

Drawings

Fig. 1 is a perspective view of a tape-type disposable diaper 1 as an example of an absorbent article.

Fig. 2 is a schematic cross-sectional view of the exterior body 13 taken along AA' of fig. 1, in which (a) shows a state before moisture absorption, and (b) shows a state after moisture absorption.

Fig. 3 is a developed view of the exterior body 13.

Fig. 4 is a view showing a pants-type disposable diaper 2, in which (a) is a perspective view and (b) is an unfolded plan view seen from the skin side.

Fig. 5 is a schematic cross-sectional view of another example of the exterior body, in which (a) shows a state before moisture absorption and (b) shows a state after moisture absorption.

Fig. 6 is a schematic cross-sectional view of another example of the exterior body, in which (a) shows a state before moisture absorption and (b) shows a state after moisture absorption.

Detailed Description

As a result of various studies, the present inventors have found that, by bonding a part of the absorbent sheet to the inner layer sheet or the outer layer sheet at least one position and swelling the absorbent sheet in a direction different from the extensible direction of the inner layer sheet and the outer layer sheet upon absorbing moisture, a space is formed at least between the inner layer sheet and the absorbent sheet, and a sticky feeling on the skin of a wearer can be reduced by the formed space.

Hereinafter, a tape-type disposable diaper as an embodiment of an absorbent article according to the present invention will be described with reference to the accompanying drawings. As shown in fig. 1, the tape-type disposable diaper 1 according to the present embodiment includes an absorbent body 12 that absorbs excrement of a wearer and an exterior body 13 that holds the absorbent body 12 at a predetermined position of the wearer. Other examples of absorbent articles include pants-type disposable diapers, split-type disposable diapers, and disposable sanitary pants as shown in fig. 4.

As shown in fig. 2(a), the exterior body 13 includes an inner layer sheet 131 on the skin side, an outer layer sheet 132 on the non-skin side or the outer side, and a moisture-absorbing sheet 133 provided between the inner layer sheet 131 and the outer layer sheet 132. In the present embodiment, the absorbent sheet 133 is bonded to the inner layer sheet 131 through the bonding portions 134a to 134c, and is bonded to the outer layer sheet 132 through the bonding portions 134d to 134 e. The absorbent sheet 133 only needs to be provided on at least a part of the exterior body 13, and may be any part (for example, the back side portion 13a, the stomach side portion 13b, the back surrounding portion 13c, and the stomach surrounding portion 13 d). From the viewpoint of effectively removing sweat, it is preferable to provide the moisture-absorbing sheet 133 at least on the back-surrounding portion 13 c.

In the present embodiment, the absorbent sheet 133 is provided such that the fiber orientation of the absorbent sheet 133 is the same as the fiber orientation direction of the inner layer sheet 131 and the outer layer sheet 132. As described later, the absorbent sheet 133 is made of cellulose fibers and has a characteristic of easily wrinkling in a direction orthogonal to the fiber direction when absorbing moisture, so that the absorbent sheet 133 tends to swell in the fiber direction. On the other hand, the inner layer sheet 131 and the outer layer sheet 132 are made of a thermoplastic resin nonwoven fabric described later, and are difficult to extend in the fiber direction. For this reason, when the absorbent sheet 133 absorbs sweat, as shown in fig. 2(b), the absorbent sheet 133 in the non-bonded portion between the two bonded portions 134 swells and is separated from the inner layer sheet 131 and the outer layer sheet 132 to have an overhanging shape, and a space is formed. In this way, since the moisture-absorbing sheet 133 having sweat absorbed therein is separated from the inner sheet 131 and the outer sheet 132, a sticky feeling on the skin of the wearer is avoided.

As described above, in the present embodiment, the fiber orientation of the inner layer sheet 131 and the outer layer sheet 132 is set in the same direction as the fiber orientation of the absorbent sheet 133. However, as long as the above-described effect is achieved, it is only necessary to set the fiber orientation of the absorbent sheet 133 in a direction different from the fiber orientation orthogonal to the inner sheet 131. That is, as shown in fig. 3(a), the fiber orientation X of the absorbent sheet 133 is most preferably set to intersect the direction Y orthogonal to the fiber orientation of the inner layer sheet 131 at 90 ° (the fiber orientations of the inner layer sheet 131 and the outer layer sheet 132 are set in the same manner as the fiber orientation of the absorbent sheet 133). However, as shown in fig. 3(b), the fiber orientation X of the absorbent sheet 133 may be set to intersect the direction Y orthogonal to the fiber orientation of the inner sheet 131 at 30 ° or more, more preferably at 45 ° or more.

The absorbent sheet 133 may be bonded to the outer sheet 132 at least one point. The bonded portions 134d and 134e of the outer sheet 132 and the absorbent sheet 133 are preferably, but not necessarily, disposed at positions opposing the bonded portions 134a and 134c of the inner sheet 131 across the absorbent sheet 133. The term "disposed at the opposite position" includes a case where the joining portions are completely opposed to each other and a case where 80% or more of the joining portions 134a and 134c are opposed to the joining portions 134d and 134 e. In the case where the inner sheet 131 and the absorbent sheet 133 are partially bonded, the sheets are more easily separated from each other to form a space, which is preferable. The bonding portions 134a to 134e only need to have a discontinuous shape. From the viewpoint of easy formation of space, the shape of the bonded portions is preferably in the form of dots or lines extending for a predetermined distance in a direction orthogonal to the fiber orientation of the absorbent sheet 133, and arranged in a pattern at regular intervals. In addition, in the case where the bonding portions 134a to 134e have a dot shape, they are preferably arranged along the fiber orientation direction of the absorbent sheet 133.

The bonding portions 134a to 134e preferably have a linear shape provided in a direction orthogonal to the fiber orientation of the absorbent sheet 133. The pitch of the linear bonding portions is preferably 2mm or more and 20mm or less, more preferably 3mm or more and 15mm or less, and most preferably 5mm or more and 12mm or less. That is, the lower limit of the pitch of the linear bonding portions is preferably 2mm, more preferably 3mm, and most preferably 5 mm. The upper limit of the pitch of the bonded portions is preferably 20mm, more preferably 15mm, and most preferably 12 mm.

The width of the linear bonding portions 134a to 134e is preferably 0.1mm or more and 5mm or less, more preferably 0.3mm or more and 4mm or less, and most preferably 0.5mm or more and 3mm or less. That is, the lower limit is preferably 0.1mm, more preferably 0.3mm, and most preferably 0.5 mm. The upper limit of the width of the bonding portion is preferably 5mm, more preferably 4mm, and most preferably 3 mm.

The pitch between two adjacent bonding portions is preferably 0.5mm or more and 18mm or less, more preferably 1mm or more and 16mm or less, and most preferably 2mm or more and 14mm or less. That is, the lower limit of the distance between two adjacent bonding portions is preferably 0.5mm, more preferably 1mm, and most preferably 2 mm. The upper limit of the distance between the adjacent two bonded portions is preferably 18mm, more preferably 16mm, and most preferably 14 mm.

The distance and size of the bonded portions 134a to 134e are preferably determined as appropriate depending on the thickness of the inner sheet 131 and the absorbent sheet 133, or the elongation due to moisture absorption, or the like. The bonding may be any of thermal bonding such as heat sealing, mechanical bonding such as sewing, chemical bonding using an adhesive, ultrasonic bonding, or a combination thereof, and is preferably bonding using an adhesive. Examples of the adhesive include water-soluble adhesives, solvent-based adhesives, hot-melt adhesives, epoxy adhesives, silicone adhesives, polyurethane adhesives, and the like, and among them, hot-melt adhesives are preferable. The hot melt adhesive is not limited to a specific adhesive, and a publicly known adhesive such as an adhesive of ethylene vinyl acetate copolymer (EVA), Polyolefin (PO), Polyamide (PA), Synthetic Rubber (SR), Acryl (ACR), polyurethane (PUR, moisture-curable type), or a mixture of two or more thereof may be used. It is preferable to use a styrene-butadiene type hot melt adhesive.

The inner layer sheet 131 and the outer layer sheet 132 are made of a thermoplastic fiber sheet or an elastic sheet. Examples of thermoplastic fibers include polyethylene fibers, polypropylene fibers, polyethylene/polypropylene composite fibers, polyethylene terephthalate fibers, polybutylene terephthalate fibers, polyamide fibers, and the like, with polyethylene fibers or polypropylene fibers or a combination thereof with polyethylene terephthalate fibers, polybutylene terephthalate fibers, and the like being preferred.

Examples of the thermoplastic fiber sheet include: a spunbonded nonwoven fabric, a thermobonded nonwoven fabric, a breathable nonwoven fabric, a spunlaced nonwoven fabric, and the like of the above fibers, and among them, a spunbonded nonwoven fabric and a breathable nonwoven fabric are preferable. In addition, the thermoplastic fiber sheet is stretchable, waterproof, and the like.

The elastic sheet is for example a composite sheet of one or more sheets of thermoplastic fibres and other materials. Another example of a preferable material is an elastic material such as a sheet excellent in elasticity described in japanese patent laid-open No. JP2008-179128, which is formed by bonding a plurality of unidirectionally arranged elastic threads between two stretchable nonwoven fabrics in a substantially unstretched state over the entire length. The nonwoven fabric may be a nonwoven fabric of the above thermoplastic fibers. The elastic wire is made of a thread-like thermoplastic elastomer or rubber, and examples of the elastic wire include styrene-ethylene-butadiene-styrene (SEBS), styrene-ethylene-propylene-styrene (SEPS), natural rubber, synthetic rubber, and the like.

The inner layer sheet 131 is preferably more hydrophilic than the outer layer sheet 132 and less hydrophilic than the absorbent sheet 133 so that sweat of the wearer easily passes through and excreta do not easily leak to the outside. In this case, the outer sheet 132 is hydrophobic. The hydrophilicity of the inner layer sheet 131 and the outer layer sheet 132 may be adjusted by applying a hydrophilic agent to the nonwoven fabric formed of the thermoplastic fibers described above. The hydrophilic agent is not particularly limited as long as the hydrophilic agent is a general hydrophilic agent for sanitary goods. Hydrophilicity was measured by the method for measuring the contact angle of the fiber described below, and the smaller the contact angle, the higher the hydrophilicity. Specifically, if the contact angle is 90 degrees or more, the sheet is determined to be hydrophobic with low hydrophilicity, and if the contact angle is less than 90 degrees, the sheet is determined to be hydrophilic with high hydrophilicity.

The contact angle of the inner layer sheet 131 is preferably 50 degrees or more and 130 degrees or less, more preferably 70 degrees or more and 120 degrees or less, and most preferably 80 degrees or more and 110 degrees or less. That is, the lower limit of the contact angle of the inner layer sheet 131 is preferably 50 degrees, more preferably 70 degrees, and most preferably 80 degrees. The upper limit of the contact angle of the inner layer sheet 131 is preferably 130 degrees, more preferably 120 degrees, and most preferably 110 degrees.

The outer sheet 132 preferably has a high contact angle from the viewpoint of dew prevention. For this reason, the ideal contact angle is 180 degrees. For this reason, only the lower limit is specified as a preferred value. The lower limit of the contact angle is preferably 90 degrees or more, more preferably 110 degrees or more, and most preferably 130 degrees or more. The upper limit of the contact angle of the outer sheet 132 is 180 degrees.

The contact angle of the absorbent sheet 133 is preferably 5 degrees or more and 70 degrees or less, more preferably 10 degrees or more and 60 degrees or less, and most preferably 15 degrees or more and 50 degrees or less. That is, the lower limit of the contact angle of the absorbent sheet 133 is preferably 5 degrees, more preferably 10 degrees, and most preferably 15 degrees. The upper limit of the contact angle of the absorbent sheet 133 is preferably 70 degrees, more preferably 60 degrees, and most preferably 50 degrees.

The difference between the contact angle of the moisture-absorbing sheet 133 and the contact angle of the inner layer sheet 131 is preferably 30 degrees or more and 90 degrees or less, more preferably 40 degrees or more and 85 degrees or less, and most preferably 50 degrees or more and 80 degrees or less. That is, the lower limit of the difference between the contact angle of the absorbent sheet 133 and the contact angle of the inner layer sheet 131 is preferably 30 degrees, more preferably 40 degrees, and most preferably 50 degrees. The upper limit of the difference in contact angle is preferably 90 degrees, more preferably 85 degrees, and most preferably 80 degrees.

The difference between the contact angle of the inner layer sheet 131 and the contact angle of the outer layer sheet 132 is preferably 5 degrees or more and 90 degrees or less, more preferably 10 degrees or more and 80 degrees or less, and most preferably 15 degrees or more and 70 degrees or less. That is, the lower limit of the difference between the contact angle of the inner layer sheet 131 and the contact angle of the outer layer sheet 132 is preferably 5 degrees, more preferably 10 degrees, and most preferably 15 degrees. The upper limit of the difference in contact angle is preferably 90 degrees, more preferably 80 degrees, and most preferably 70 degrees.

[ method for measuring contact Angle of fiber ]

The contact angle is measured in a measuring environment at 20 ℃ using, for example, a contact angle measuring instrument MCA-J manufactured by Kyowa Interface Science co., Ltd. Immediately after dropping ion-exchanged water (about 20 picoliters) onto the surface of the inner layer or the outer layer, the contact angle was measured using a contact angle measuring instrument. Measurements were made at five or more positions of the fibers constituting the hydrophilic region, and the average value was taken as the contact angle. Note that in the case where an area (for example, a hydrophilic area) is taken out from a diaper as an example of an absorbent article and evaluated and measured, and the area is fixed to another member by an adhesive, fusion, or the like, the fixed portion is measured or removed in the non-fixed portion, and then the area is taken out and measured. At this time, from the viewpoint of minimizing the influence of the hydrophilic agent applied to the region, it is preferable not to employ a method (for example, applying a solvent or blowing hot air with a dryer) that may cause deterioration or loss of the oil agent as a method of removing the fixed portion.

The grammage of the thermoplastic fiber sheet or the thermoplastic fiber composite sheet is preferably 5g/m from the viewpoint of sufficient strength and air permeability²Above and 50g/m²Hereinafter, more preferably 7g/m²Above and 45g/m²Hereinafter, the most preferable is 10g/m²Above and 40g/m²The following. That is, the lower limit is preferably 5g/m²More preferably 7g/m²And most preferably 10g/m². The upper limit of the grammage is preferably 50g/m²More preferably 45g/m²And most preferably 40g/m². Note that the relationship between the grammage of the inner layer sheet 131 and the outer layer sheet 132 is not particularly limited. However, in view of the fact that liquid is transferred from the inner layer sheet 131 to the absorbent sheet 133 and the outer layer sheet 132 needs to be protected from dew, the outer layer sheet 132 preferably has a higher grammage than the inner layer sheet 131.

In the present embodiment, the absorbent sheet 133 is made of cellulose fibers, and the absorbent sheet only needs to contain at least 20 mass%, preferably 50 mass%, and more preferably 70 mass% of cellulose fibers. Examples of cellulosic fibers include wood pulp, recycled pulp, chemical pulp, cotton, rayon, and the like, as well as mixtures thereof. Wood pulp, recycled pulp and chemical pulp are preferable in view of high water absorbability and easy processability. As the absorbent sheet 133, paper made by papermaking of cellulose fibers, a woven fabric made by spinning and then weaving cellulose fibers, or a spunlace fabric formed of thermoplastic fibers (for example, polyethylene fibers, polypropylene fibers, or polyethylene terephthalate fibers) and cellulose fibers, or a combination thereof can be used, and paper is preferably used. Various types of treatments can be applied to the paper or fabric. Examples of the treatment include water resistance treatment and creping treatment. In addition, a plurality of sheets of paper, cloth, or a combination thereof may be used. Note that the hydrophilic property of the absorbent sheet 133 is higher than that of the inner sheet 131.

The absorbent sheet 133 preferably has a thickness of 5g/m²Above and 60g/m²More preferably having a grammage of 7g/m²Above and 55g/m²The following grammage, and most preferably 9g/m²Above and 50g/m²The following gram weights. That is, the lower limit of the grammage is 5g/m²More preferably 7g/m²And most preferably 9g/m². The upper limit of the grammage is preferably 60g/m²More preferably 55g/m²And most preferably 50g/m². In the case where the absorbent sheet 133 is paper, the lower limit of the grammage is 5g/m²More preferably 7g/m²Most preferably 9g/m²And the upper limit is preferably 25g/m²More preferably 22g/m²Most preferably 20g/m². When the absorbent sheet 133 is hydroentangled or the like other than paper, the lower limit of the grammage is 15g/m²More preferably 20g/m²Most preferably 25g/m²And the upper limit is preferably 60g/m²More preferably 55g/m²Most preferably 50g/m². In addition, the elongation due to humidity (preferably measured by elongation measurement) is 2% or more, more preferably 5% or more, and most preferably 7% or more.

In the present embodiment, the bonded portion of the absorbent sheet 133 bonded to the inner sheet 131 may be configured to be separated from the inner sheet 131 upon absorption of moisture. Since the absorbent sheet 133 is separated from the inner sheet 131 upon absorption of moisture, the degree of freedom of the absorbent sheet 133 is increased, so that the absorbent sheet 133 can be further swollen in the fiber orientation direction, and a larger space can be formed between the sheets.

Examples of modes of separation from the inner layer sheet 131 include: the mode in which the absorbent sheet 133 collapses to be separated due to moisture absorption, or the mode in which the strength of the absorbent sheet 133 is reduced due to moisture absorption and the absorbent sheet 133 is broken and separated upon stretching. As such a moisture-absorbing sheet 133, the tear strength as measured by JIS P-8113 is preferably 200cN/25mm or less, more preferably 150cN/25mm or less. In addition, as another mode of separation from the inner layer sheet 131, there are the following modes: the absorbent sheet 133 is bonded to the inner layer sheet 131 by a hot melt adhesive (e.g., a water-soluble adhesive such as a water-soluble polymer hot melt adhesive) whose adhesive strength decreases upon absorbing moisture. Examples of such water-soluble binders include water-soluble polymer-based binders (e.g., polyvinyl alcohol, starch, carboxymethyl cellulose, water-soluble acrylic resins, etc.).

In the present embodiment, the absorbent sheet 133 may be creped. The creping process is performed to form a large number of wrinkles extending, for example, in a direction orthogonal to the orientation direction of the fibers of the absorbent sheet 133. The creping process is performed by using a common doctor blade and further changing the conveying speed. The lower limit of the crepe ratio of the absorbent sheet 133 is 2%, and more preferably 5%. The upper limit of the creping rate is preferably 40%, more preferably 30%. The wrinkling rate can be evaluated by the following measurement method. The measurement was performed at 23. + -. 2 ℃ and 50. + -. 5% relative humidity, and the sample was stored in the same environment for 24 hours or more before the measurement.

< measurement method of wrinkling Rate >

The measurement was performed by underwater elongation. The outer ply 132 or the inner ply 131 was cut into 100mm × 100mm to prepare a measurement sample, the measurement sample was immersed in water and then pulled up, and the wrinkle ratio was calculated from the amount of dimensional change by the following formula:

percent wrinkling (%) ((dimension after soaking)/(dimension before soaking) -1) × 100

The absorbent sheet 133 can be stretched by pressing with an emboss roller or the like. By the stretching process, the absorbent sheet 133 becomes more easily stretched by absorbing moisture, and the flexibility is also increased. In the case where the absorbent sheet 133 is a sheet subjected to a creping process or a stretching process, the bonding portions 134a to 134c are preferably provided in the direction of such a process.

As shown in fig. 4(a), the pants-type disposable diaper of the present invention may further include elastic members (fig. 6, 235a to 235c) on the outer cover 23. The elastic bodies 235a to 235c are provided between the inner sheet 231 and the outer sheet 232 so that the stretching direction thereof is along the girth direction. The elastic bodies 235a to 235c are bonded to the absorbent sheet 233 at least at both side portions S, and in this case, bonding is preferably performed using the above-described hot melt adhesive.

Examples of the elastic bodies 235a to 235c include rubber threads (e.g., natural rubber, butadiene rubber, styrene-butadiene rubber, and urethane rubber), flat rubber, and elastic sheets containing filaments, and the like. Among them, a rubber thread is preferable. The lower limit of the fineness of the rubber thread is preferably 300dtex, more preferably 400dtex, and the upper limit is preferably 1300dtex, more preferably 1200 dtex. In addition, the lower limit of the pitch between the rubber wires is preferably 2mm, more preferably 3mm, and the upper limit is preferably 20mm, more preferably 15 mm.

As shown in fig. 6(a), the absorbent sheet 233 may be disposed between the elastic bodies 235a to 235c and the outer layer 232. In this case, as shown in fig. 6(b), there is an advantage that the space between two adjacent elastic bodies of the elastic bodies 235a to 235c can be used for swelling of the absorbent sheet 133 in the fiber orientation direction. As shown in fig. 6(a) and 6(b), the absorbent sheet 233 may be bonded to the inner layer sheet 231 through elastic bodies 235a to 235 c. In this case, it is preferable that the joint portions 235a to 235c are provided with a hot melt adhesive to enhance water absorption.

With regard to the above embodiment, the present invention also discloses an absorbent article as follows:

<1> an absorbent article comprising:

an absorbent body; and

an outer package for holding an absorbent body, wherein,

the outer package includes: an inner layer sheet disposed on the skin side of a wearer, an outer layer sheet disposed on the non-skin side, and an absorbent sheet disposed between the inner layer sheet and the outer layer sheet,

the inner layer sheet and the outer layer sheet are thermoplastic fiber sheets or thermoplastic fiber composite sheets,

the absorbent sheet contains cellulosic fibers,

the fiber orientation of the absorbent sheet is arranged in a direction different from the direction orthogonal to the fiber orientation of the inner sheet, and

at least a part of the absorbent sheet is bonded to the outer cover so as to be separated from the inner sheet by swelling in the fiber orientation direction due to moisture absorption.

<2> the absorbent article according to <1>, wherein the absorbent sheet is configured to have the same fiber orientation as the fiber orientation direction of the inner sheet and the outer sheet.

<3> the absorbent article according to <1>, wherein the absorbent sheet is configured to have a fiber orientation different from the fiber orientation direction of the inner sheet and the outer sheet.

<4> the absorbent article according to any one of <1> to <3>, wherein the absorbent sheet is joined to the inner layer sheet and the outer layer sheet by a joining portion, respectively.

<5> the absorbent article according to <4>, wherein the bonded portion between the absorbent sheet and the inner sheet faces the bonded portion between the absorbent sheet and the outer sheet with the absorbent sheet therebetween.

<6> the absorbent article according to <4> or <5>, wherein the bonded portion has a discontinuous shape.

<7> the absorbent article according to <6>, wherein the bonded portions have a dot shape and are arranged along the fiber orientation direction of the absorbent sheet.

<8> the absorbent article according to <6>, wherein the bonded portion has a linear shape and is provided in a direction orthogonal to the fiber orientation direction of the absorbent sheet.

<9> the absorbent article according to <8>, wherein the pitch of the bonded portions is 2mm to 20 mm.

<10> the absorbent article according to <8> or <9>, wherein the width of the bonded portion is 0.1mm or more and 5mm or less.

<11> the absorbent article according to any one of <8> to <10>, wherein a distance between two adjacent bonded portions is 0.5mm or more and 18mm or less.

<12> the absorbent article according to any one of <1> to <11>, wherein the composite sheet of thermoplastic fibers is a composite sheet of one or more of the sheets of thermoplastic fibers and another material.

<13> the absorbent article according to any one of <1> to <11>, wherein the absorbent sheet has a tear strength of 200cN/25mm or less as measured according to JISP-8113.

<14> the absorbent article according to any one of <1> to <13>, wherein the absorbent sheet has a crepe ratio of 2% or more and 40% or less.

<15> the absorbent article according to any one of <1> to <14>, wherein the inner sheet has a contact angle of 50 degrees or more and 130 degrees or less.

<16> the absorbent article according to any one of <1> to <15>, wherein the outer sheet has a contact angle of 90 degrees or more and 180 degrees or less.

<17> the absorbent article according to any one of <1> to <16>, wherein the absorbent sheet has a contact angle of 5 degrees or more and 70 degrees or less.

<18> the absorbent article according to any one of <1> to <17>, wherein a difference between a contact angle of the absorbent sheet and a contact angle of the inner layer sheet is 30 degrees or more and 90 degrees or less.

<19> the absorbent article according to any one of <1> to <18>, wherein a difference between a contact angle of the inner layer sheet and a contact angle of the outer layer sheet is 5 degrees or more and 90 degrees or less.

<20> the absorbent article according to any one of <1> to <19>, further comprising an elastic body between the inner sheet and the outer sheet.

<21> the absorbent article according to <20>, wherein the elastic body is a rubber thread.

<22> the absorbent article according to any one of <1> to <21>, wherein the elastic body is disposed between the inner sheet and the absorbent sheet.

<23> the absorbent article according to any one of <19> to <22>, wherein the absorbent sheet is bonded to the rubber thread by a hot melt adhesive and bonded to the inner sheet by the rubber thread.

<24> the absorbent article according to any one of <1> to <23>, wherein the absorbent sheet is bonded to the outer sheet at least one point.

<25> the absorbent article according to <24>, wherein the bonded portions between the absorbent sheet and the outer sheet are arranged according to a predetermined pattern.

<26> the absorbent article according to <24> or <25>, wherein the bonded portion between the absorbent sheet and the outer sheet is formed of a hot melt adhesive.

<27> the absorbent article according to any one of <1> to <26>, wherein the outer sheet is hydrophobic.

<28> the absorbent article according to any one of <1> to <27>, wherein the inner sheet and the outer sheet are spunbonded nonwoven fabrics.

<29> the absorbent article according to any one of <1> to <28>, wherein the inner sheet and the outer sheet are air-permeable nonwoven fabrics.

INDUSTRIAL APPLICABILITY

The absorbent article of the present invention reduces stuffiness in the diaper due to perspiration or the like, and does not give a sticky feeling to the skin of the wearer.

Description of the reference numerals

Disposable diaper of tape type 1

2-pants type disposable diaper

12. 22 absorbent body

13. 23 outer package

131. 231 inner layer sheet

132. 232 outer layer sheet

133. 233 moisture-absorbing sheet

134 a-e, 234 a-e junction

235 a-c elastomer