WO2022209913A1

WO2022209913A1 - Composite sheet for absorbent articles, and composite sheet for waist parts of absorbent articles

Info

Publication number: WO2022209913A1
Application number: PCT/JP2022/012020
Authority: WO
Inventors: 貴之三好; 聡光野; 謙仁池内
Original assignee: ユニ・チャーム株式会社
Priority date: 2021-03-30
Filing date: 2022-03-16
Publication date: 2022-10-06
Also published as: JP2022154780A

Abstract

The present invention provides a composite sheet for absorbent articles and a composite sheet for waist parts of absorbent articles, each of the composite sheets having excellent texture as a whole. A composite sheet 10A for waist parts of absorbent articles, the composite sheet having a first direction, a second direction and a thickness direction, which are perpendicular to each other. This composite sheet 10A for waist parts of absorbent articles sequentially comprises, in the thickness direction, a first nonwoven fabric, an elastic material that expands and contracts in the first direction, and a second nonwoven fabric, while being additionally provided with a plurality of point-like bonded parts where the first nonwoven fabric, the elastic material and the second nonwoven fabric are bonded with each other; and the bending stiffness of the composite sheet in the second direction as determined by a KES method is from 0.02 (N·m2/m × 10-4) to 0.65 (N·m2/m × 10-4).

Description

Composite sheet for absorbent article and waist area of absorbent article

The present invention relates to a composite sheet for absorbent articles and a waist portion of absorbent articles.

Investigations are being made to improve the feel of composite sheets for absorbent articles. For example, Patent Document 1 discloses a main body portion having a liquid-permeable topsheet, a liquid-impermeable backside sheet, and an absorbent body interposed between the topsheet and the backside sheet, and a back side of the main body portion. The exterior sheet is formed by laminating one or more nonwoven fabrics, and the twist degree of the outermost nonwoven fabric located on the outermost side is 3.8 gf cm / cm or less. An absorbent article is disclosed that is

Further, Patent Document 2 discloses an absorbent article having a longitudinal direction and a lateral direction, an absorbent main body provided with an absorbent core, and a pair of waist portions. The waist portion includes a skin-side sheet portion located closest to the skin side, and in at least one of the pair of waist portions, the bending rigidity of the skin-side sheet portion according to the KES method is 0.0096 N·m ² /. m×10 ⁻⁴ or less, and the inner sheet portion is arranged on the non-skin side of the skin side sheet portion. The bending rigidity of the inner layer sheet portion according to the KES method is higher than the bending rigidity of the skin side sheet portion, and the inner layer sheet portion is arranged on the skin side of the absorbent main body straddling the edge on the waist side of the absorbent main body in the vertical direction. It is

JP 2010-131167 A JP 2019-187744 A

As in the case of the exterior sheet of Patent Document 1, there is a limit to improving the texture of the entire composite sheet composed of a plurality of nonwoven fabrics only by setting the degree of twist of the outermost nonwoven fabric to 3.8 gf·cm/cm or less. rice field. Further, Patent Document 2 discloses that the bending rigidity of the skin-side sheet portion is set to a predetermined value or less, but the composite sheet as a whole still has room for improvement.

An object of the present invention is to provide a composite sheet for absorbent articles and a waist portion of absorbent articles, which is excellent in texture as a composite sheet.

The present invention provides a composite sheet for a waistline portion of an absorbent article having a first direction, a second direction and a thickness direction orthogonal to each other, wherein the first nonwoven fabric, the first nonwoven fabric, the first nonwoven fabric, and the first nonwoven fabric an elastic material that stretches in a direction and a second nonwoven fabric; The composite sheet has a bending rigidity of 0.02 (N·m ² /m×10 ⁻⁴ ) or more and 0.65 (N·m ² /m×10 ⁻⁴ ) or less according to the KES method in two directions.

The composite sheet for the absorbent article and the waist portion of the absorbent article according to the present invention is excellent in texture as a composite sheet.

1 is a plan view of a composite sheet according to an embodiment; FIG. FIG. 4 is a cross-sectional view of the composite sheet according to the embodiment when it is stretched; FIG. 4 is a cross-sectional view of the composite sheet according to the embodiment when it is shrunk. It is a cross-sectional view of the fibers of the first nonwoven fabric and the second nonwoven fabric according to the embodiment. It is a sectional view of the textiles of the 1st nonwoven fabric concerning the modification of an embodiment, and the 2nd nonwoven fabric. 1 is a perspective view showing an absorbent article using a composite sheet according to an embodiment; FIG. FIG. 11 is a plan view of a composite sheet according to a modified example;

The embodiments of the present invention relate to the following aspects.

[Aspect 1]
A composite sheet for a waist portion of an absorbent article having a first direction, a second direction and a thickness direction that are orthogonal to each other,
A first nonwoven fabric, an elastic material that stretches and contracts in the first direction, and a second nonwoven fabric are provided in order in the thickness direction;
further comprising a plurality of point-like joints where the first nonwoven fabric, the elastic material and the second nonwoven fabric are joined together,
The composite sheet has a flexural rigidity of 0.02 (N·m ² /m×10 ⁻⁴ ) or more and 0.65 (N·m ² /m×10 ⁻⁴ ) or less according to the KES method in the second direction. ,
composite sheet.
A composite sheet for a waist portion of an absorbent article having a first direction, a second direction, and a thickness direction orthogonal to each other, comprising, in order in the thickness direction, a first nonwoven fabric and an elastic material that stretches in the first direction. , and a second nonwoven fabric, further comprising a plurality of point-like joints joining the first nonwoven fabric, the elastic material and the second nonwoven fabric, wherein the composite sheet has a flexural rigidity of 0.5 in the second direction according to the KES method. 02 (N·m ² /m×10 ⁻⁴ ) or more and 0.65 (N·m ² /m×10 ⁻⁴ ) or less.
Since the composite sheet stretches in the first direction, it can be applied to the composite sheet for the waist portion of the absorbent article by arranging the first direction parallel to the waist of the wearer.
In addition, the composite sheet has a flexural rigidity of 0.02 (N·m ² /m×10 ⁻⁴ ) or more and 0.65 (N·m ² /m×10 ⁻⁴ ) or less according to the KES method in the second direction. As a result, it is highly flexible and easily deforms according to the movement of the wearer's skin.
Furthermore, the first nonwoven fabric, the elastic material, and the second nonwoven fabric are joined together by a plurality of point-like joints so as to stretch in the first direction. Since the plurality of point-like joints do not have directionality, the composite sheet is easily bendable in the first direction and the second direction, and easily conforms to the wearer's skin.
Therefore, the composite sheet easily deforms according to the movement of the wearer's skin, and is easy to conform to the wearer's skin, so that the composite sheet is excellent in touch.

[Aspect 2]
The composite sheet according to aspect 1, wherein the composite sheet has a thickness of 0.6 mm or more and 2.0 mm or less when a load of 4.9 kPa is applied in the thickness direction.
The composite sheet has a thickness of 0.6 mm or more and 2.0 mm or less when a load of 4.9 kPa is applied in the thickness direction, so that when the wearer wears the absorbent article using the composite sheet, The composite sheet is easily thinned. That is, when the absorbent article using the composite sheet is worn, the composite sheet is sandwiched between the wearer and the lower garment, and a load is applied in the thickness direction. The composite sheet, whose thickness is reduced by this load, becomes more deformable, so that it can be more easily deformed according to the movements of the wearer.

[Aspect 3]
Each of the first nonwoven fabric and the second nonwoven fabric is a spunbond nonwoven fabric made of a core-sheath type composite fiber having a core portion and a sheath portion,
the core contains a propylene/α-olefin random copolymer,
The sheath contains an ethylene-based polymer,
The composite sheet according to

aspect

1 or 2.
Each of the first nonwoven fabric and the second nonwoven fabric is a spunbond nonwoven fabric made of core-sheath type composite fibers having a core and a sheath, the core containing a propylene/α-olefin random copolymer, and the sheath contains an ethylene polymer. Since the core part contains the propylene/α-olefin random copolymer, it is possible to obtain sufficient breaking strength as a composite sheet, so that it can be suitably used for the composite sheet for the waist part of the absorbent article. can be done. By containing the ethylene-based polymer in the sheath, the surface of the composite sheet has flexibility derived from the ethylene-based polymer.

[Aspect 4]
The composite sheet according to any one of aspects 1 to 3, wherein the plurality of point-like joints thermally join the first nonwoven fabric, the elastic material, and the second nonwoven fabric to each other.
Since the plurality of point-like joints thermally join the first nonwoven fabric, the elastic material, and the second nonwoven fabric to each other, the thickness is thinner than in the case of joining with an adhesive. Therefore, the composite sheet is easy to bend in the first direction and the second direction, so it is easy to conform to the wearer's skin.
Furthermore, each of the first nonwoven fabric and the second nonwoven fabric is a spunbond nonwoven fabric made of core-sheath type composite fibers having a core and a sheath, the core containing a propylene/α-olefin random copolymer, and the sheath When the portion contains an ethylene-based polymer, the bonded portion after thermal bonding is less likely to harden compared to conventional core-sheath type conjugate fibers in which the core portion is formed of a propylene-based polymer. As a result, the composite sheet can be easily deformed.

[Aspect 5]
The composite sheet according to any one of aspects 1 to 4, wherein the plurality of dot-like joints adjacent to each other in the first direction are shifted in the second direction.
A plurality of dot-like joints adjacent to each other in the first direction are shifted in the second direction, so that the joints have less directivity. Therefore, the composite sheet is more flexible in the first direction and the second direction, and is more comfortable to the wearer's skin.

[Aspect 6]
The composite sheet according to any one of aspects 1 to 5, wherein the elastic material is a nonwoven fabric.
By using the nonwoven fabric as the elastic material, the gathers are more uniformly formed in the first nonwoven fabric and the second nonwoven fabric compared to the case of using rubber thread. Therefore, the composite sheet can prevent local pressure from being applied by making contact with the wearer's skin in a more dispersed manner, and can more reliably conform to the wearer's skin. Moreover, since the elastic material is a nonwoven fabric, the composite sheet can also maintain air permeability.

[Aspect 7]
The composite sheet according to any one of aspects 1 to 6, wherein the first nonwoven fabric has a cantilever bending resistance in the first direction of 20 mm or more and 40 mm or less.
When the cantilever bending resistance of the first nonwoven fabric in the first direction is 20 mm or more and 40 mm or less, the gathers of the first nonwoven fabric are easily deformed in the first direction. By arranging the first direction parallel to the wearer's girth, the composite sheet tends to deform along the wearer's girth. Therefore, the composite sheet is easily deformed along the waist of the wearer, and thus easily conforms to the wearer's skin.

[Aspect 8]
The composite sheet according to aspect 7, wherein the second nonwoven fabric has a cantilever bending resistance in the first direction of 20 mm or more and 40 mm or less.
When the cantilever bending resistance of the second nonwoven fabric in the first direction is 20 mm or more and 40 mm or less, the gathers of the second nonwoven fabric are easily deformed in the first direction. By arranging the first direction parallel to the wearer's girth, the composite sheet tends to deform along the wearer's girth. Therefore, in the composite sheet, not only the first nonwoven fabric but also the second nonwoven fabric are easily deformed along the waist of the wearer, so that the composite sheet is more comfortable to the skin.

[Aspect 9]
The composite sheet according to any one of aspects 1 to 8, wherein the hydrophilicity of the second nonwoven fabric is higher than the hydrophilicity of the first nonwoven fabric, and the elastic material is fibrous.
Since the elastic material is fibrous, ie, rubber thread or elastic nonwoven fabric, the composite sheet can transfer moisture such as perspiration from the first nonwoven fabric to the second nonwoven fabric. Since the hydrophilicity of the second nonwoven fabric is higher than the hydrophilicity of the first nonwoven fabric, the second nonwoven fabric has the first nonwoven fabric, the elastic material and the second Moisture adhering to the surface of the first nonwoven fabric can be absorbed through the portion where the two nonwoven fabrics are close to each other. Therefore, when the composite sheet is applied to the waist region of an absorbent article, the first nonwoven fabric is arranged on the wearer's skin side to allow moisture such as perspiration of the wearer to migrate to the second nonwoven fabric. Excellent quick-drying properties. Moreover, since the composite sheet is easily deformed in accordance with the movement of the wearer and easily conforms to the wearer's skin, quick-drying properties can be obtained more reliably over a wide area of the wearer's skin.

[Aspect 10]
Each of the first nonwoven fabric and the second nonwoven fabric is a spunbond nonwoven fabric made of a core-sheath type composite fiber having a core portion and a sheath portion,
the core contains a propylene/α-olefin random copolymer,
The sheath contains an ethylene-based polymer,
The core portion of the second nonwoven fabric is
It is eccentric with respect to the sheath part and partially exposed from the sheath part,
Hydrophilic agent is kneaded,
A composite sheet according to aspect 9.
By containing the propylene/α-olefin random copolymer in the core, sufficient breaking strength as a composite sheet can be obtained, and by containing the ethylene-based polymer in the sheath, Flexibility derived from the ethylene-based polymer is obtained on the surface.
When the second nonwoven fabric is coated with a hydrophilic agent, the hydrophilic agent dissolves in water when the second nonwoven fabric comes into contact with moisture such as sweat of the wearer. As a result, when the hydrophilic agent flows out together with the water, the hydrophilicity of the second nonwoven fabric decreases, and when the hydrophilic agent moves into the first nonwoven fabric together with the water, the second nonwoven fabric and the first nonwoven fabric become less hydrophilic. The difference in hydrophilicity becomes small, and it becomes difficult for moisture such as perspiration of the wearer to migrate from the first nonwoven fabric to the second nonwoven fabric.
In the above composite sheet, the core of the second nonwoven fabric is eccentric with respect to the sheath, a part of which is exposed from the sheath, and a hydrophilic agent is kneaded therein. As a result, the second nonwoven fabric can exhibit higher hydrophilicity than the first nonwoven fabric, and can maintain a state in which the second nonwoven fabric has higher hydrophilicity than the first nonwoven fabric. As a result, the composite sheet can maintain quick-drying properties while being worn by the wearer.
The inventors of the present application have found that when a hydrophilic agent is kneaded into the sheath containing the ethylene polymer, the effect of the hydrophilic agent is difficult to manifest.

[Aspect 11]
The composite sheet according to aspect 9 or 10, wherein the second nonwoven fabric has a water absorbency of 10 mm or more and 100 mm or less in the first direction and the second direction according to the Klemm method.
The water absorbency of the second nonwoven fabric according to the Klemm method is 10 mm or more and 100 mm or less in the first direction and the second direction. The second nonwoven fabric absorbs the water adhering to the surface of the first nonwoven fabric, the portion where the first nonwoven fabric and the second nonwoven fabric are close to each other, that is, the portion where the first nonwoven fabric, the elastic material and the second nonwoven fabric are close to each other around the joint. can be more reliably absorbed through Since the second nonwoven fabric has a water absorbency of 10 mm or more and 100 mm or less according to the Klemm method, the water absorbed by the second nonwoven fabric diffuses outside the composite sheet (second nonwoven fabric). Therefore, the composite sheet can improve moisture transpiration.

[Aspect 12]
A composite sheet for an absorbent article having a first direction, a second direction and a thickness direction orthogonal to each other,
A nonwoven fabric and an elastic material that stretches and contracts in the first direction are provided in order in the thickness direction,
further comprising a plurality of point-like joints where the nonwoven fabric and the elastic material are joined together,
The composite sheet has a flexural rigidity of 0.02 (N·m ² /m×10 ⁻⁴ ) or more and 0.65 (N·m ² /m×10 ⁻⁴ ) or less according to the KES method in the second direction. ,
composite sheet.
The composite sheet can be applied to composite sheets for absorbent articles. In addition, the composite sheet has a flexural rigidity of 0.02 (N·m ² /m×10 ⁻⁴ ) or more and 0.65 (N·m ² /m×10 ⁻⁴ ) or less according to the KES method in the second direction. As a result, it is highly flexible and easily deforms according to the movement of the wearer's skin. Further, the nonwoven fabric and the elastic material are joined together by a plurality of point-like joints so as to stretch in the first direction. Since the plurality of point-like joints do not have directionality, the composite sheet is easily bendable in the first direction and the second direction, and easily conforms to the wearer's skin. Therefore, the composite sheet easily deforms according to the movement of the wearer's skin, and is easy to conform to the wearer's skin, so that the composite sheet is excellent in touch.

[Aspect 13]
A composite sheet for an absorbent article having a first direction, a second direction and a thickness direction orthogonal to each other,
A first nonwoven fabric, an elastic material that stretches and contracts in the first direction, and a second nonwoven fabric are provided in order in the thickness direction;
further comprising a plurality of point-like joints where the first nonwoven fabric, the elastic material and the second nonwoven fabric are joined together,
The composite sheet has a flexural rigidity of 0.02 (N·m ² /m×10 ⁻⁴ ) or more and 0.65 (N·m ² /m×10 ⁻⁴ ) or less according to the KES method in the second direction. ,
composite sheet.
The composite sheet can be applied to composite sheets for absorbent articles. In addition, the composite sheet has a flexural rigidity of 0.02 (N·m ² /m×10 ⁻⁴ ) or more and 0.65 (N·m ² /m×10 ⁻⁴ ) or less according to the KES method in the second direction. As a result, it is highly flexible and easily deforms according to the movement of the wearer's skin. Furthermore, the first nonwoven fabric, the elastic material, and the second nonwoven fabric are joined together by a plurality of point-like joints so as to stretch in the first direction. Since the plurality of point-like joints do not have directionality, the composite sheet is easily bendable in the first direction and the second direction, and easily conforms to the wearer's skin. Therefore, the composite sheet easily deforms according to the movement of the wearer's skin, and is easy to conform to the wearer's skin, so that the composite sheet is excellent in touch.

<Overall composition>
Embodiments of the present invention will be described below with reference to the drawings.
The composite sheet 10A shown in FIG. 1 has a first direction W, a second direction L and a thickness direction T (not shown in FIG. 1) which are orthogonal to each other. As shown in FIGS. 2A and 2B, the composite sheet 10A includes a first nonwoven fabric 12, an elastic member 14, and a second nonwoven fabric 16 in order in the thickness direction T. As shown in FIGS. When the composite sheet 10A is applied to the waist composite sheet of an absorbent article, the first nonwoven fabric 12 is arranged on the skin side, the second nonwoven fabric 16 is arranged on the non-skin side, and the first direction W is arranged around the wearer's waist. arranged in parallel.

The thickness, basis weight, and the like of the composite sheet 10A are not particularly limited as long as they do not impair the effects of the present invention, and any thickness, basis weight, and the like can be adopted according to desired flexibility, strength, and the like. The thickness of the composite sheet 10A is, for example, preferably 1.0 (mm) or more and 3.5 (mm) or less, more preferably 1.0 (mm) or more and 3.0 (mm) or less. The basis weight of the composite sheet 10A is, for example, preferably 70 (g/m ² ) or more and 150 (g/m ² ) or less, more preferably 90 (g/m ² ) or more and 140 (g/m ² ) or less.

The composite sheet 10A preferably has a flexural rigidity of 0.02 (N·m ² /m×10 ⁻⁴ ) or more and 0.65 (N·m ² /m×10 ⁻⁴ ) or less according to the KES method in the second direction L. is 0.02 (N·m ² /m×10 ⁻⁴ ) or more and 0.20 (N·m ² /m×10 ⁻⁴ ) or less. By setting the bending rigidity according to the KES method in the second direction L to 0.65 (Nm ² /m×10 ⁻⁴ ) or less, the composite sheet 10A can be easily folded along the first direction W. Can transform.

The thickness of the composite sheet 10A when a load of 4.9 kPa is applied in the thickness direction T (hereinafter referred to as "thickness when compressed") is preferably 0.6 mm or more and 2.0 mm or less, and more It is preferably 0.8 mm or more and 1.8 mm or less. When the composite sheet 10A is applied to the waist composite sheet of an absorbent article, the composite sheet 10A is sandwiched between the wearer and the lower garment worn over the absorbent article, and is subjected to a load in the thickness direction T. is added. Therefore, when the thickness is 0.6 mm or more and 2.0 mm or less when compressed, the composite sheet 10A is sufficiently thin when worn.

The breaking strength of the composite sheet 10A is not particularly limited as long as it can be used as a waist composite sheet for absorbent articles, and can be, for example, 35 (N/50 mm) or more and 75 (N/50 mm) or less. Breaking strength is the value obtained by dividing the maximum tensile load required to break the sample by the width of the sample.

The first nonwoven fabric 12 forms a contact surface that can come into contact with the wearer's skin when wearing the absorbent article using the composite sheet 10A. The second nonwoven fabric 16 forms the non-skin side surface of the wearer when the absorbent article using the composite sheet 10A is worn. Nonwoven fabrics that can be used as the first nonwoven fabric 12 and the second nonwoven fabric 16 include air-through nonwoven fabrics, spunbond nonwoven fabrics, point-bond nonwoven fabrics, spunlace nonwoven fabrics, needle-punched nonwoven fabrics, meltblown nonwoven fabrics, and combinations thereof (e.g., SMS, etc.). nonwoven fabric can be adopted. The first nonwoven fabric 12 and the second nonwoven fabric 16 may be the same nonwoven fabric or different nonwoven fabrics.

The form of the fibers constituting the first nonwoven fabric 12 and the second nonwoven fabric 16 is not particularly limited. Side-type conjugate fibers and split-type conjugate fibers may also be used. The first nonwoven fabric 12 and the second nonwoven fabric 16 may be core-sheath composite fibers having a core portion 20 and a sheath portion 22, as shown in FIG. 3A. The core portion 20 and the sheath portion 22 may be concentric as shown in FIG. 3A or eccentric as shown in FIG. 3B. The core 20 is the A region and the sheath 22 is the B region.

The ratio of area A to area B is 70:30 to 10:90 (area A: area B) on a mass basis. More preferably, this ratio is between 60:40 and 20:80. When the ratio of the region A to the region B of the conjugate fiber is within the above range, the strength and flexibility tend to be well balanced. The average fiber diameter of the conjugate fiber is preferably 10 μm or more and 40 μm or less, more preferably 10 μm or more and 25 μm or less, and still more preferably 12 μm or more and 20 μm or less. When the average fiber diameter of the conjugate fiber is within the above range, there is a tendency that the balance between strength and flexibility is excellent.

The thickness, basis weight, etc. of the first nonwoven fabric 12 and the second nonwoven fabric 16 are not particularly limited as long as they do not impair the effects of the present invention, and any thickness, basis weight, etc. according to the desired flexibility, strength, etc. are adopted. be able to. The thickness of the first nonwoven fabric 12 and the second nonwoven fabric 16 is, for example, preferably 0.05 (mm) or more and 2.00 (mm) or less, more preferably 0.10 (mm) or more and 1.00 (mm) or less. . The basis weight of the first nonwoven fabric 12 and the second nonwoven fabric 16 is, for example, preferably 8 (g/m ² ) or more and 30 (g/m ² ) or less, and 13 (g/m ² ) or more and 25 (g/m ² ). The following are more preferred.

The breaking strength of the first nonwoven fabric 12 and the second nonwoven fabric 16 is not particularly limited as long as it does not impair the effects of the present invention, and any breaking strength can be adopted according to desired flexibility, strength, and the like. The breaking strength in the first direction W of the first nonwoven fabric 12 and the second nonwoven fabric 16 can be, for example, 10 (N/50 mm) or more and 50 (N/50 mm) or less. The breaking strength in the second direction L of the first nonwoven fabric 12 and the second nonwoven fabric 16 can be, for example, 3 (N/50 mm) or more and 30 (N/50 mm) or less.

The cantilever bending resistance in the first direction W of the first nonwoven fabric 12 and the second nonwoven fabric 16 is 20 mm or more and 40 mm or less. Since the cantilever bending resistance is 20 mm or more and 40 mm or less, the first nonwoven fabric 12 and the second nonwoven fabric 16 can be easily deformed with a line along the second direction L as a folding line. Therefore, when the composite sheet 10A is applied to a composite sheet for a waist portion of an absorbent article, it can be easily deformed along the wearer's waist.

In the case of this embodiment, the first nonwoven fabric 12 is preferably hydrophobic. For example, thermoplastic resin fibers can be used as the constituent fibers of the first nonwoven fabric 12 . Examples of thermoplastic resin fibers that can be used as constituent fibers of the first nonwoven fabric 12 include olefin resins such as polyethylene (PE) and polypropylene (PP), polyester resins such as polyethylene terephthalate (PET), and 6-nylon. Fibers made of known thermoplastic resins such as polyamide-based resins can be used. These resins may be used alone, or two or more kinds of resins may be used in combination.

The second nonwoven fabric 16 preferably has higher hydrophilicity than the first nonwoven fabric 12 . The water absorbency of the second nonwoven fabric 16 according to the Klemm method is preferably 10 mm or more and 100 mm or less in the first direction W and the second direction L. As the constituent fibers of the second non-woven fabric 16, for example, cellulose-based fibers or hydrophilic thermoplastic resin fibers can be used. These fibers may be used alone, or two or more types of fibers may be used in combination. Hydrophilization treatment includes, for example, manufacturing non-woven fabrics after treating fibers with a hydrophilic agent, manufacturing non-woven fabrics by forming fibers from resin kneaded with hydrophilic agents, and coating non-woven fabrics with hydrophilic agents and surfactants.・Spraying, etc. can be mentioned.

Cellulosic fibers that can be used as constituent fibers of the second nonwoven fabric 16 include, for example, natural cellulose fibers (eg, vegetable fibers such as cotton), regenerated cellulose fibers, refined cellulose fibers, semi-synthetic cellulose fibers, and the like.

Examples of thermoplastic resin fibers that can be used as constituent fibers of the second nonwoven fabric 16 include olefin resins such as polyethylene (PE) and polypropylene (PP), polyester resins such as polyethylene terephthalate (PET), and 6-nylon. Fibers made of known thermoplastic resins such as polyamide-based resins can be used. These resins may be used alone, or two or more kinds of resins may be used in combination.

As shown in FIG. 3B, the core portion 20 of the core-sheath type composite fiber that constitutes the second nonwoven fabric 16 is eccentric with respect to the sheath portion 22, and a part thereof is exposed from the sheath portion 22, and the hydrophilic agent is added. It may be kneaded. The second nonwoven fabric 16 has hydrophilicity because a portion of the core 20 into which the hydrophilic agent is kneaded is exposed from the sheath 22 .

Region A may contain a propylene/α-olefin random copolymer. The content of structural units derived from propylene in the propylene/α-olefin random copolymer is 50% by mass or more and less than 100% by mass, preferably 70% by mass or more and 99% by mass or less, and 80% by mass or more and 98% by mass or less. is more preferred. The content of α-olefin-derived structural units in the propylene/α-olefin random copolymer is more than 0% by mass and 50% by mass or less, preferably 1% by mass or more and 30% by mass or less, and 2% by mass or more. 20 mass % or less is more preferable. When the content of the propylene-derived structural unit and/or the α-olefin-derived structural unit in the propylene/α-olefin random copolymer is within the above range, the balance between strength and flexibility tends to be excellent.

The α-olefin in the propylene/α-olefin random copolymer is not particularly limited as long as it is an α-olefin other than propylene. Examples of α-olefins include ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene and the like. Among these, ethylene is preferable as the α-olefin from the viewpoint of further improving flexibility.

The content of the propylene/α-olefin random copolymer in region A is preferably 10% by mass or more and 100% by mass or less, more preferably 50% by mass or more and 100% by mass or less, and further 90% by mass or more and 100% by mass or less. Preferably, 99% by mass or more and 100% by mass or less is particularly preferable. When the content of the propylene/α-olefin random copolymer in the region A is within the above range, the balance between strength and flexibility tends to be excellent.

From the viewpoint of further improving strength, region A preferably further contains a propylene homopolymer or multiple types of propylene/α-olefin random copolymers. When region A contains a propylene homopolymer, the strength tends to be excellent.

Region B may comprise an ethylene-based polymer. Region B has a density of 0.900 kg/m ³ or more and 0.945 kg/m ³ or less. The density of region B is preferably 910 kg/m ³ or more and 940 kg/m ³ or less. When the density is within the above range, the balance between strength and flexibility tends to be excellent.

The content of structural units derived from ethylene in the ethylene-based polymer is 50 mass % or more, preferably 70 mass % or more and 99.8 mass % or less, more preferably 90 mass % or more and 99 mass % or less. The content of other structural units in the ethylene polymer is 0% by mass or more and 50% by mass or less, preferably 0.2% by mass or more and 30% by mass or less, and more preferably 1% by mass or more and 10% by mass or less. When the content of structural units derived from ethylene and/or other structural units in the ethylene-based polymer is within the above range, the balance between strength and flexibility tends to be excellent.

Examples of monomers that make up other structural units include α-olefins. α-Olefins are not particularly limited as long as they are other than ethylene. , 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene and the like. Among these, 1-butene and 4-methyl-1-pentene are preferred as the α-olefin from the viewpoint of further improving the balance between strength and flexibility.

The ethylene-based polymer preferably contains an ethylene/α-olefin copolymer. The ethylene/α-olefin copolymer is preferably at least one selected from the group consisting of an ethylene/1-butene copolymer and an ethylene/4-methyl-1-pentene copolymer. When the ethylene-based polymer has the above aspect, it tends to have an excellent balance between strength and flexibility.

The content of the ethylene polymer in region B is preferably 10% by mass or more and 100% by mass or less, more preferably 50% by mass or more and 100% by mass or less, further preferably 90% by mass or more and 100% by mass or less, and 99% by mass. More than 100% by mass or less is particularly preferable. When the content of the ethylene-based polymer in region B is within the above range, there is a tendency for the balance between strength and flexibility to be excellent.

Hydrophilic agents can be further classified into penetrants and wetting agents. The second nonwoven fabric 16 may contain both a penetrant and a wetting agent, or may contain no penetrating agent and a wetting agent. From the viewpoint of excellent hydrophilicity, the hydrophilic agent preferably contains both a penetrating agent and a wetting agent.

The hydrophilic agent preferably contains at least one of a sulfonate and a sulfate as a penetrant. Sulfonates include alkylbenzenesulfonates, alkylnaphthalenesulfonates, α-olefinsulfonates, and alkylsulfosuccinates. These sulfonates are preferably alkali metal salts. Sulfate salts include higher alcohol sulfates, alkyl sulfates, and the like. These sulfate ester salts are preferably alkali metal salts. Among these, the hydrophilic agent preferably contains a sulfonate, more preferably an alkali metal salt of a sulfonic acid, as a penetrating agent.

When the hydrophilic agent contains a wetting agent, the wetting agent is not particularly limited. For example, the hydrophilic agent may contain any of cationic surfactants, anionic surfactants, amphoteric surfactants, and nonionic surfactants as wetting agents.

The content of the hydrophilic agent is preferably 0.01% by mass or more and 2.0% by mass or less, more preferably 0.05% by mass or more and 1.0% by mass or less, and 0.1% by mass or more. It is more preferably 0.5% by mass or less. As a method of kneading the hydrophilic agent into the raw material resin of the core-sheath type composite fiber, for example, the above-described hydrophilic agent is added to the above-described raw material resin of the core portion 20, and then spun to form a fiber. method.

A film-like elastic material and a fibrous elastic material can be used for the elastic material 14 . As the film-like elastic material, for example, an elastic film made of thermoplastic resin such as urethane resin or polyolefin resin, or an elastic film made of polyester resin can be used. A fibrous elastic material is preferable because it provides breathability and liquid permeability.

As the fibrous elastic material, thread rubber or elastic nonwoven fabric can be used. As the thread rubber, a thread-shaped thermoplastic elastomer such as urethane or ethylene-vinyl acetate copolymer (EVA) can be used. The rubber thread is joined to the first nonwoven fabric 12 and the second nonwoven fabric 16 in a stretched state due to the speed difference between the supply speed and the winding speed.

The elastic nonwoven fabric can be exemplified by a nonwoven fabric obtained by subjecting a nonwoven fabric having substantially elastic thermoplastic elastomer fibers and substantially inelastic thermoplastic resin fibers to appropriate stretching treatment such as gear stretching. That is, by performing such a drawing process, the substantially inelastic thermoplastic resin fibers contained in the nonwoven fabric are plastically deformed, or if the joints between the fibers are destroyed, etc., the thermoplastic elastomer fibers become substantially elastic. The nonwoven fabric can be changed into a structure that does not easily inhibit stretching deformation. In this way, the stretchability of the nonwoven fabric is exhibited, and the nonwoven fabric can be used as an elastic nonwoven fabric. Examples of substantially elastic thermoplastic elastomers include polyurethane-based elastomers, polystyrene-based elastomers, polyolefin-based elastomers, and polyamide-based elastomers. Examples of substantially inelastic thermoplastic resin fibers include fibers containing polyolefin-based resins, and polyolefin-based resins include polyethylene (PE), polypropylene (PP), ethylene/α-olefin copolymers, and the like. can be exemplified. The basis weight of the elastic nonwoven fabric is not particularly limited, and may be, for example, 15 (g/m ² ) or more and 80 (g/m ² ) or less. The expansion ratio of the elastic member 14 is not particularly limited, and may be, for example, 1.5 times or more and 3.5 times or less. The stretch ratio is the ratio of the length of the elastic member 14 after stretching to the length of the elastic member 14 when it is not stretched.

As shown in FIG. 1, the composite sheet 10A further includes a plurality of point-like joints 18 where the first nonwoven fabric 12, the elastic member 14 and the second nonwoven fabric 16 are joined together. Adhesive bonding or thermal bonding can be applied to the plurality of point-like joints 18 . A hot-melt adhesive, for example, can be used as the adhesive.

Thermal bonding can be applied when the first nonwoven fabric 12, the elastic material 14 and the second nonwoven fabric 16 contain thermoplastic resin fibers. In thermal bonding, the first nonwoven fabric 12, the elastic material 14 and the second nonwoven fabric 16 are melted by heating the first nonwoven fabric 12, the elastic material 14 and the second nonwoven fabric 16 using heat or ultrasonic waves until the melting point of the thermoplastic resin is exceeded. 14 and the second nonwoven 16 are bonded together. In the case of thermal bonding, since no adhesive is interposed between the first nonwoven fabric 12, the elastic member 14, and the second nonwoven fabric 16, the thickness of the joint 18 can be made thinner than when an adhesive is used.

The shape and size of each of the dot-like joints 18 and the distance between the joints 18 are not particularly limited, and can be appropriately selected according to the size and thickness of the composite sheet 10A. For example, the shape of each point-like joint 18 viewed from the thickness direction T may be circular or polygonal such as triangular and rectangular. The size of the dot-like joint 18 may be, for example, a diameter in the case of a circle and a length of one side of 0.1 mm to 5.0 mm in the case of a rectangle. The distance between the joints 18 may be 1 (mm) or more and 5 (mm) or less. The dot-like joints 18 are arranged uniformly in the surface direction of the composite sheet 10A by setting the distance between the joints 18 within the above range. By uniformly arranging the dot-like joints 18, gathers having a size corresponding to the distance between the joints 18 are uniformly formed in the surface direction of the composite sheet 10A.

A plurality of point-like joints 18 adjacent to each other in the first direction W may be shifted in the second direction L. The distance in the second direction L between the plurality of point-like joints 18 adjacent to each other in the first direction W is preferably 0.1 mm or more, more preferably 0.2 mm or more, and 0.8 (mm). The above is more preferable. Each of the dot-like joints 18 may be arranged in a staggered manner in the first direction W and the second direction L, as shown in FIG. 1 .

<Action and effect>
Since the composite sheet 10A stretches in the first direction W, as shown in FIG. 4, by arranging the first direction W parallel to the wearer's waistline DW, the composite sheet for the waistline portion of the absorbent article can be used. applicable. For example, a disposable diaper as an absorbent article 1 includes a crotch portion 2 covering the crotch of the wearer and a waist portion 3 covering the waist of the wearer. The waist portion 3 is formed of the composite sheet 10A. The composite sheet 10A is arranged such that the first nonwoven fabric 12 is on the skin side and the second nonwoven fabric 16 is on the non-skin side, and the first direction W is parallel to the wearer's waistline DW. When the composite sheet 10A is applied to the composite sheet for the waist portion 3 of the absorbent article 1, the composite sheet 10A is stretched in the waist direction DW and attached to the wearer. The composite sheet 10A contracts according to the length of the wearer's waistline DW while the first nonwoven fabric 12 is in contact with the wearer's skin.

The composite sheet 10A has a bending rigidity of 0.02 (N·m ² /m×10 ⁻⁴ ) or more and 0.65 (N·m ² /m×10 ⁻⁴ ) or less according to the KES method in the second direction L. As a result, it is highly flexible and easily deforms according to the movement of the wearer's skin. That is, since the composite sheet 10A has a sufficiently small bending rigidity in the direction from the waist DW to the crotch, the composite sheet 10A flexibly follows the movements of the wearer even when the wearer squats down. In particular, when the flexural rigidity according to the KES method is 0.20 (N·m ² /m×10 ⁻⁴ ) or less, it is possible to obtain softness equivalent to cloth used for underwear.

The first nonwoven fabric 12, the elastic material 14, and the second nonwoven fabric 16 are joined together by a plurality of point-like joining portions 18 so as to stretch in the first direction W. Since the plurality of point-like joints 18 do not have directivity, the composite sheet 10A is easily bendable in the first direction W and the second direction L, and easily conforms to the wearer's skin.

Therefore, the composite sheet 10A easily deforms according to the movement of the wearer's skin, and is easy to conform to the wearer's skin, so it is excellent in touch.

Incidentally, a composite sheet having a plurality of linear joints extending in the first direction W or the second direction L has high flexural rigidity in the direction in which the joints extend, so it is difficult to bend in the direction in which the joints extend. Therefore, a composite sheet having linear joints is difficult to conform to the wearer's skin and gives the wearer a sense of discomfort.

A wearer who wears the absorbent article 1 to which the composite sheet 10A according to the present embodiment is applied usually wears underwear. When the absorbent article 1 is worn, the composite sheet 10A is sandwiched between the wearer and the lower garment and pressure is applied in the thickness direction T. As shown in FIG. The composite sheet 10A has a thickness of 0.6 mm or more and 2.0 mm or less when a pressure of 4.9 kPa is applied in the thickness direction T, so that the wearer can wear the absorbent article 1. In this state, the composite sheet 10A easily becomes thin. That is, the composite sheet 10A sandwiched between the wearer and the lower garment and reduced in thickness due to the load in the thickness direction T becomes more deformable, so that it can be more easily deformed according to the movement of the wearer. can.

Each of the first nonwoven fabric 12 and the second nonwoven fabric 16 is a spunbond nonwoven fabric made of a core-sheath type composite fiber having a core portion 20 and a sheath portion 22, and the core portion 20 is made of a propylene/α-olefin random copolymer. and the sheath 22 contains an ethylene polymer. Since the core portion 20 contains the propylene/α-olefin random copolymer, the composite sheet 10A can have sufficient breaking strength. It can be suitably used for Since the sheath portion 22 contains the ethylene-based polymer, the surface of the composite sheet 10A is provided with flexibility derived from the ethylene-based polymer, so that the composite sheet 10A easily conforms to the wearer's skin.

The plurality of point-like joints 18 thermally join the first nonwoven fabric 12, the elastic material 14, and the second nonwoven fabric 16 to each other, so the thickness is thinner than in the case of joining with an adhesive. Therefore, the composite sheet 10A is easily bendable in the first direction W and the second direction L, and therefore easily conforms to the wearer's skin.

Furthermore, each of the first nonwoven fabric 12 and the second nonwoven fabric 16 is a spunbond nonwoven fabric made of a core-sheath type composite fiber having a core portion 20 and a sheath portion 22, and the core portion 20 is a propylene/α-olefin random copolymer. When the sheath 22 contains an ethylene polymer, the joint 18 after thermal bonding becomes harder than in a conventional core-sheath type composite fiber in which the core 20 is formed of a propylene polymer. Hateful. As a result, the composite sheet 10A can be easily deformed.

A plurality of dot-like joints 18 adjacent to each other in the first direction W are offset in the second direction L, so that the joints 18 can be made to have less directivity. Therefore, the composite sheet 10A is more likely to bend in the first direction W and the second direction L, and is more comfortable to the wearer's skin.

By using the nonwoven fabric as the elastic material 14, the gathers can be formed in the first nonwoven fabric 12 and the second nonwoven fabric 16 more uniformly than in the case of using rubber threads. Therefore, the composite sheet 10A contacts the wearer's skin in a more distributed manner, thereby preventing local pressure from being applied and more reliably conforming to the wearer's skin. Moreover, since the elastic material 14 is a nonwoven fabric, the composite sheet 10A can also maintain air permeability. The composite sheet 10A according to this embodiment preferably has an air permeability of 50 (CC/cm ² ·sec) or more, preferably 70 (CC/cm ² ·sec) or more.

The first nonwoven fabric 12 has a cantilever bending resistance of 20 mm or more and 40 mm or less in the first direction W, so that the gathers of the first nonwoven fabric 12 are easily deformed in the first direction W. By arranging the first direction W parallel to the wearer's waistline DW, the composite sheet 10A is easily deformed along the wearer's waistline DW. Therefore, the composite sheet 10A is easily deformed along the wearer's waistline DW, and thus easily fits the wearer's skin.

The gathers of the second nonwoven fabric 16 are easily deformed in the first direction W because the cantilever bending resistance in the first direction W of the second nonwoven fabric 16 is 20 mm or more and 40 mm or less. By arranging the first direction W parallel to the wearer's waistline DW, it is easy to deform along the wearer's waistline DW. Therefore, in the composite sheet 10A, not only the first nonwoven fabric 12 but also the second nonwoven fabric 16 are easily deformed along the wearer's waistline DW, so that the composite sheet 10A is more comfortable to the skin.

Moisture such as sweat discharged from the skin comes into contact with the first nonwoven fabric 12 that is in contact with the skin. Even if the first nonwoven fabric 12 is hydrophobic, since the elastic material 14 is fibrous and the hydrophilicity of the second nonwoven fabric 16 is higher than the hydrophilicity of the first nonwoven fabric 12, it is in contact with the first nonwoven fabric 12. The second nonwoven fabric 16 absorbs the moisture contained in the fabric. That is, the second nonwoven fabric 16 passes through the portions of the first nonwoven fabric 12 and the second nonwoven fabric 16 that are close to each other, that is, the portions that the first nonwoven fabric 12, the elastic material 14, and the second nonwoven fabric 16 are close to each other around the joint 18. It can absorb moisture attached to the surface of the first nonwoven fabric 12 .

Therefore, when the composite sheet 10A is applied to the waist portion 3 of the absorbent article 1, the first nonwoven fabric 12 is arranged on the wearer's skin side, thereby absorbing moisture such as sweat of the wearer to the second level. Since it can be transferred to the nonwoven fabric 16, it is excellent in quick drying. Moreover, since the composite sheet 10A is easily deformed in accordance with the movement of the wearer and easily conforms to the wearer's skin, the wearer's skin can be dried more reliably over a wide area.

Since the core portion 20 contains the propylene/α-olefin random copolymer, the composite sheet 10A can have sufficient breaking strength, and the sheath portion 22 contains the ethylene polymer. As a result, flexibility derived from the ethylene-based polymer can be obtained on the surface of the composite sheet 10A.

In the composite sheet 10A, the core portion 20 of the second nonwoven fabric 16 is eccentric with respect to the sheath portion 22, part of which is exposed from the sheath portion 22, and a hydrophilic agent is kneaded therein. As a result, the second nonwoven fabric 16 can exhibit higher hydrophilicity than the first nonwoven fabric 12, and can maintain a state in which the second nonwoven fabric 16 has higher hydrophilicity than the first nonwoven fabric 12. . As a result, the composite sheet 10A can maintain quick-drying properties while the absorbent article 1 is being worn by the wearer.

The water absorbency of the second nonwoven fabric 16 according to the Klemm method is 10 mm or more and 100 mm or less in the first direction W and the second direction L. The second nonwoven fabric 16 absorbs the moisture adhering to the surface of the first nonwoven fabric 12 , the first nonwoven fabric 12 , the elastic material 14 , and the second nonwoven fabric 16 around the joints 18 where the first nonwoven fabric 12 and the second nonwoven fabric 16 are adjacent to each other. Through the portions where the two nonwoven fabrics 16 are close to each other, the absorbent can be more reliably absorbed. Since the water absorbency of the second nonwoven fabric 16 according to the Klemm method is 10 mm or more and 100 mm or less, the water absorbed by the second nonwoven fabric 16 diffuses outside the composite sheet 10A (the second nonwoven fabric 16), so that the moisture transpiration is improved. can be improved. The composite sheet 10A according to this embodiment preferably has a moisture transpiration property of 15(%) or more, preferably 30(%) or more.

<Modification>
The present invention is not limited to the above embodiments, and can be modified as appropriate within the scope of the gist of the present invention. For example, in the case of the above-described embodiment, the case where the dot-like joints are arranged in a grid pattern has been described, but the present invention is not limited to this, and as shown in FIG. good. Joint portions 18 adjacent to each other in the first direction W shown in FIG. 5 are shifted in the second direction L by about 0.2 mm. A composite sheet 10B having dot-like joints 18 shown in FIG. 5 can obtain the same effect as the above embodiment.

In the above embodiment, the composite sheet is provided with the first nonwoven fabric 12, the elastic member 14, and the second nonwoven fabric 16 in order in the thickness direction T, but the present invention is not limited to this. For example, the composite sheet includes a case in which the first nonwoven fabric 12 and the elastic member 14 are provided in order in the thickness direction T, and a case in which the elastic member 14 and the second nonwoven fabric 16 are provided.

<Measurement method>
A method for measuring each numerical value described in the above embodiment will be described below.

(basis weight)
First, one or a plurality of test pieces are cut out from the composite sheet when not stretched so that the total area is 500 (cm ² ) or more, and used as a sample. Next, the total weight of the sample is measured with a direct reading balance (example: electronic balance HF-300 manufactured by Kensei Kogyo Co., Ltd.). The basis weight of the composite sheet is obtained by calculating the weight per unit area (g/m ² ) of the sample from the last measured total weight and the total area of the sample.
The basis weights of the first nonwoven fabric, the second nonwoven fabric, and the elastic material are obtained as follows. First, after separating each from the composite sheet, one or a plurality of sample pieces are cut out from each material so that the total area is 500 (cm ² ) or more in a wrinkled state. The total weight of each material is measured, and the weight per unit area (g/m ² ) of each sample is calculated from each total weight and each total area, and this is defined as the basis weight of each material.

(thickness)
The thickness is measured using a thickness gauge FS-60DS (presser foot diameter: 50.5 mm, measuring pressure: 0.3 KPa) manufactured by Daiei Kagaku Seiki Seisakusho.

(Bending stiffness by KES method)
The flexural rigidity by the KES method measures the flexural rigidity of the composite sheet in the second direction using a large bending tester KES-FB2-L manufactured by Kato Tech Co., Ltd. A sample having a length of 40 mm in the first direction and a length of 60 mm in the second direction is cut from the composite sheet to obtain a sample.

The measurement conditions are as follows.
SENS: 4
SIZE: 4 cm (set to the measurement width of the sample)
Mode: 1 cycle Bending curvature: 0.5 cm ^-1
B: K=0.1 to 0.3 cm

(thickness when compressed)
The thickness when compressed is measured using an automated compression tester KES-FB3-A manufactured by Kato Tech Co., Ltd.
The measurement conditions are as follows.
SENS: 2
Speed: 0.02mm/sec Stroke: 5mm/10V
Pressurized area: ^2cm2
Uptake interval: 0.1 second Maximum load: 50 g/cm ²
Number of repetitions: 1 time

(cantilever bending resistance)
The cantilever bending resistance is measured using an electric cantilever softness tester CAN-1MCA manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd. First, the first nonwoven fabric and the second nonwoven fabric are separated from the composite sheet, and cut into a size having a length of 150 mm in the first direction and a length of 25 mm in the second direction to obtain a sample. The sample is then placed on the test bench. The sample is slid in the direction of the 45-degree slope of the test stand at a speed of 5 mm/sec, and the measured moving distance is defined as the cantilever bending resistance (mm).

(Breaking strength)
The breaking strength is measured using Autograph AG-1 manufactured by Shimadzu Corporation. First, a sample having a length of 50 mm in the first direction and a length of 70 mm in the second direction is cut out from the unstretched composite sheet to obtain a sample. Next, the breaking strength of the composite sheet in the second direction was measured at a distance between chucks of 50 mm and a tensile speed of 250 mm/sec. "N/50mm" means breaking strength (N) per width of 50mm.
First, the first nonwoven fabric and the second nonwoven fabric were separated from the composite sheet, and a sample having a length of 50 mm in the first direction and a length of 70 mm in the second direction and a sample having a length of 70 mm in the first direction and a length of 70 mm in the second direction were prepared. A sample having a size of 50 mm in length was prepared. Next, the breaking strength of the composite sheet in the first direction and the second direction was measured at a distance between chucks of 50 mm and a tensile speed of 50 mm/sec.

(Krem water absorption)
Based on JIS P 8141:2004, it was evaluated as the suction height (mm) for 5 minutes.

(Permeability)
The air permeability is calculated using the following formula by measuring the air resistance value using an air permeability tester KES-F8-AP1 manufactured by Kato Tech Co., Ltd.
Air permeability (CC/cm ² /sec) = 12.5/airflow resistance value

(moisture transpiration)
In the moisture transpiration test, the amount of moisture that can be transferred from the first surface side of the composite sheet to the second surface side for a certain period of time (1 hour in this example) and evaporate. It is a test that evaluates how much
The moisture transpiration test is performed according to the following procedure.
1. A composite sheet to be tested is cut into a size of 70 mm×70 mm and used as a sample.
2. 0.5 ml of physiological saline is dropped onto the watch glass.
3. Place the sample on the clock glass with the skin side (first nonwoven fabric side) facing down, apply a load of 250 g to the entire surface of the sample, and bring the sample into contact with the physiological saline from the skin side. and leave it for 1 minute. After 1 minute, remove the load and start the test.
4. Total weight Wt (test piece + watch glass + residual saline solution) after 1 hour from the start of the test
is measured, and the transpiration rate is calculated from the following formula.
Transpiration rate (%) = ((Wo-Wt) / (Wo-W)) x 100
However, W: Weight of sample + watch glass Wo: Weight of sample + watch glass + 1 ml of physiological saline

(average fiber diameter)
First, the first nonwoven fabric and the second nonwoven fabric were separated from the composite sheet, and a 10 mm×10 mm sample of each nonwoven fabric was cut out and placed on a slide. Next, an appropriate amount of glycerin was dripped onto each sample so that the entire sample was soaked with glycerin, and a cover glass was placed thereon. Next, the sample is observed at a magnification of 1000 using a known optical microscope (for example, VHC-100 Digital Microscope Lens VH-Z450 manufactured by KEYENCE), and the fiber diameter of the fiber exposed on the surface of the sample is measured at 50 points. The average value was taken as the average fiber diameter.

EXAMPLES The present invention will be described below with reference to Examples, but the present invention is not limited to these Examples.
(A) Samples As shown in Table 1, nine types of nonwoven fabrics (1) to (9) were prepared as the first nonwoven fabric and the second nonwoven fabric. The nonwoven fabrics (1) to (4) use core-sheath type composite fibers in which the core and the sheath are eccentric and part of the core is exposed from the sheath, and the core is made of propylene/α-olefin. It is a spunbond (SB) nonwoven fabric made of a random copolymer (CoPP) and having a core-sheath ratio of 60:40 by mass, in which the sheath is made of an ethylene-based polymer. The nonwoven fabric (5) uses a core-sheath type conjugate fiber with a core-sheath ratio of 60:40 in which the core and the sheath are concentric, and the core is a propylene/α-olefin random copolymer (CoPP ) and polyolefin elastomer (POE), and the sheath is made of ethylene polymer (PE). The nonwoven fabric (6) uses splittable conjugate fibers with a mass ratio of 50:50, one of which is made of propylene/α-olefin random copolymer (CoPP) and the other is made of urethane thermoplastic elastomer (TPU). A spunbond (SB) nonwoven is formed. The nonwoven fabric (7) is a spunbond-meltblown-spun fabric in which the spunbond layer is composed of monofilaments made of a propylene/α-olefin random copolymer (CoPP), and the meltblown layer is composed of monofilaments made of a propylene-based polymer. Bonded (SMS) nonwoven fabric. The nonwoven fabric (8) is a spunbond (SB) nonwoven fabric made of monofilaments of propylene/α-olefin random copolymer (CoPP). The nonwoven fabric (9) uses a core-sheath type composite fiber in which the core and the sheath are eccentric and the core-sheath ratio is 30:70 by mass. It is a spunbond nonwoven fabric in which a part is formed of a propylene/α-olefin random copolymer (CoPP). The physical properties of each nonwoven fabric are as shown in Table 1.

As shown in Table 2, three types of elastic materials (1) to (3) were prepared. The elastic material (1) is a non-woven fabric of mixed fiber type having urethane-based thermoplastic elastomer (TPU) fibers and propylene-based polymer (PP) fibers subjected to gear drawing treatment. The elastic material (2) is spandex with a fineness of 780 dtex. The elastic material (3) is an elastic film of a styrene-based thermoplastic elastomer (TPS).

Composite sheets according to Examples (1) to (3) and Reference Examples (1) to (3) were produced by combining the nonwoven fabric and the elastic material. The composition of each composite sheet is as shown in Table 3.

In Example (1), the first nonwoven fabric and the second nonwoven fabric are core-sheath type conjugate fibers in which the core and the sheath are eccentric, and the core is a propylene/α-olefin random copolymer (CoPP). A spunbond (SB) nonwoven fabric having a sheath made of an ethylene polymer (PE) was used, and the basis weight was 15 (g/m ² ). A hydrophilic agent is kneaded into the core of the second nonwoven fabric. The elastic material was stretched 2.5 times and sandwiched between the first nonwoven fabric and the second nonwoven fabric, and produced by the ultrasonic bonding method.

Example (2) is the same as Example (1) except that the first nonwoven fabric and the second nonwoven fabric having a basis weight of 19 (g/m ² ) were used.
Example (3) is a core-sheath type composite fiber in which the core and the sheath are concentric with the first nonwoven fabric, and the core is a propylene/α-olefin random copolymer (CoPP) and a polyolefin elastomer (POE). A spunbond (SB) nonwoven fabric having a sheath made of an ethylene polymer (PE) was used. A spunbond (SB) nonwoven fabric in which the second nonwoven fabric is a split type conjugate fiber, one of which is formed of propylene/α-olefin random copolymer (CoPP) and the other is formed of urethane thermoplastic elastomer (TPU). On the other hand, a nonwoven fabric was used in which the flexibility was further improved by splitting the fibers by water jet processing, and then hydrophilicity was imparted by applying a hydrophilic agent.

Reference Example (1) is a spunbond-meltblown-spunbond (SMS) in which the first nonwoven fabric is formed of single fibers of propylene/α-olefin random copolymer (CoPP) having a basis weight of 15 (g/m ² ). ) nonwoven fabric, and a spunbond (SB) nonwoven fabric formed of single fibers of propylene/α-olefin random copolymer (CoPP) having a basis weight of 15 (g/m ² ) was used as the second nonwoven fabric.
Reference Example (2) is a spunbond-meltblown-spunbond (SMS) in which the first nonwoven fabric is formed of single fibers of a propylene/α-olefin random copolymer (CoPP) having a basis weight of 15 (g/m ² ). ) using a non-woven fabric, the second non-woven fabric is a core-sheath type composite fiber having a basis weight of 20 (g/m ² ) and an eccentric core and sheath, the core is formed of a propylene polymer (PP), A spunbond (SB) nonwoven fabric whose sheath is made of propylene/α-olefin random copolymer (CoPP) is used, and spandex having a fineness of 780 dtex is arranged in multiple rows at intervals of 10 mm as the elastic material, and is multiplied by 2.7. , the adhesive was applied, and the fabric was sandwiched between the first nonwoven fabric and the second nonwoven fabric and joined.
Reference Example (3) is the same as Reference Example (1) except that an elastic film formed of a styrene-based thermoplastic elastomer (TPS) having a basis weight of 38 (g/m ² ) is used as the elastic material.
The properties of each composite sheet were measured according to the above measuring method. Table 3 shows the results.

From the results in Table 3, the composite sheets according to Examples (1) to (3) had a flexural rigidity of 0.61 (N·m ² /m×10 ⁻⁴ ) or less according to the KES method. Moreover, the composite sheets according to Examples (1) to (3) had a transpiration rate of 33(%) or more. On the other hand, the composite sheets according to Reference Examples (1) to (3) had a flexural rigidity of 0.87 (N·m ² /m×10 ⁻⁴ ) or more and a transpiration rate of 11 (%) or less. rice field. From the above, it was confirmed that the composite sheets according to the examples are superior in feel to the skin as a whole and are superior in quick-drying properties as compared with the composite sheets according to the reference examples. Pants-type diapers were prepared using the composite sheets of Example (1) and Reference Example (1) for the waist portion, and a use test was conducted by five subjects. ) was evaluated to be superior to the diaper of Reference Example (1) in comfort and touch.

10A composite sheet 10B composite sheet 12 first nonwoven fabric 14 elastic material 16 second nonwoven fabric 18 joining portion 20 core portion 22 sheath portion

Claims

A composite sheet for a waist portion of an absorbent article having a first direction, a second direction and a thickness direction that are orthogonal to each other,
A first nonwoven fabric, an elastic material that stretches and contracts in the first direction, and a second nonwoven fabric are provided in order in the thickness direction;
further comprising a plurality of point-like joints where the first nonwoven fabric, the elastic material and the second nonwoven fabric are joined together,
The composite sheet has a flexural rigidity of 0.02 (N·m 2 /m×10 −4 ) or more and 0.65 (N·m 2 /m×10 −4 ) or less according to the KES method in the second direction. ,
composite sheet.
The composite sheet according to claim 1, wherein the composite sheet has a thickness of 0.6 mm or more and 2.0 mm or less when a load of 4.9 kPa is applied in the thickness direction.
Each of the first nonwoven fabric and the second nonwoven fabric is a spunbond nonwoven fabric made of a core-sheath type composite fiber having a core portion and a sheath portion,
the core contains a propylene/α-olefin random copolymer,
The sheath contains an ethylene-based polymer,
The composite sheet according to claim 1 or 2.
The composite sheet according to any one of claims 1 to 3, wherein the plurality of point-like joining portions thermally join the first nonwoven fabric, the elastic material, and the second nonwoven fabric.
The composite sheet according to any one of Claims 1 to 4, wherein the plurality of point-like joints adjacent to each other in the first direction are shifted in the second direction.
The composite sheet according to any one of claims 1 to 5, wherein the elastic material is a nonwoven fabric.
The composite sheet according to any one of claims 1 to 6, wherein the first nonwoven fabric has a cantilever bending resistance in the first direction of 20 mm or more and 40 mm or less.
The composite sheet according to claim 7, wherein the second nonwoven fabric has a cantilever bending resistance in the first direction of 20 mm or more and 40 mm or less.
The composite sheet according to any one of claims 1 to 8, wherein the hydrophilicity of the second nonwoven fabric is higher than that of the first nonwoven fabric, and the elastic material is fibrous.
Each of the first nonwoven fabric and the second nonwoven fabric is a spunbond nonwoven fabric made of a core-sheath type composite fiber having a core portion and a sheath portion,
the core contains a propylene/α-olefin random copolymer,
The sheath contains an ethylene-based polymer,
The core portion of the second nonwoven fabric is
It is eccentric with respect to the sheath part and partially exposed from the sheath part,
Hydrophilic agent is kneaded,
The composite sheet according to claim 9.
The composite sheet according to claim 9 or 10, wherein the second nonwoven fabric has a water absorbency of 10 mm or more and 100 mm or less in the first direction and the second direction according to the Klemm method.
A composite sheet for an absorbent article having a first direction, a second direction and a thickness direction orthogonal to each other,
A nonwoven fabric and an elastic material that stretches and contracts in the first direction are provided in order in the thickness direction,
further comprising a plurality of point-like joints where the nonwoven fabric and the elastic material are joined together,
The composite sheet has a flexural rigidity of 0.02 (N·m 2 /m×10 −4 ) or more and 0.65 (N·m 2 /m×10 −4 ) or less according to the KES method in the second direction. ,
composite sheet.
A composite sheet for an absorbent article having a first direction, a second direction and a thickness direction orthogonal to each other,
A first nonwoven fabric, an elastic material that stretches and contracts in the first direction, and a second nonwoven fabric are provided in order in the thickness direction;
further comprising a plurality of point-like joints where the first nonwoven fabric, the elastic material and the second nonwoven fabric are joined together,
The composite sheet has a flexural rigidity of 0.02 (N·m 2 /m×10 −4 ) or more and 0.65 (N·m 2 /m×10 −4 ) or less according to the KES method in the second direction. ,
composite sheet.