JP7438889B2 - absorbent articles - Google Patents

Description

The present invention relates to absorbent articles such as disposable diapers.

When wearing absorbent articles such as disposable diapers, sanitary napkins, panty liners (vaginal discharge sheets), and incontinence pads, skin irritation may occur due to stuffiness. Therefore, absorbent articles containing skin care agents have been proposed in order to provide skin care effects and suppress the occurrence of rashes.
For example, Patent Document 1 describes an absorbent article in which a skin care agent is used in the top sheet that comes into contact with the wearer's skin.

Japanese Patent Application Publication No. 2015-171649

Generally, when a hydrophilic skin care agent is used in the top sheet of an absorbent article, liquid of the wearer's excrement absorbed by the top sheet tends to return to the skin side. Furthermore, when a hydrophobic skin care agent is used in the top sheet, liquid excreta tends to be difficult to absorb into the top sheet.
As described above, when a skin care agent is applied to the top sheet, it may affect the liquid permeability and liquid return property of the top sheet, and there is room for improvement.

The present invention relates to an absorbent article containing a skin care agent that maintains good liquid permeability of the topsheet and has little liquid return.

An absorbent article according to one embodiment of the present invention includes a topsheet and an absorbent core.
The top sheet is placed on the wearer's skin side.
The absorbent body is placed on the non-skin side of the topsheet.
The top sheet includes a nonwoven fabric layer having a structure in which a plurality of convex portions protruding toward the wearer's skin are spaced apart from each other.
The nonwoven fabric layer contains a skin care agent.
The convex portion has a top portion and a shoulder portion, and the top portion has a larger contact angle with the physiological saline than the shoulder portion, and the contact angle at the top portion before and after passing the liquid is greater than that before passing the liquid. The contact angle at the shoulder portion before and after passing the liquid is smaller after passing the liquid than before passing the liquid.

According to the absorbent article of the present invention, while maintaining good liquid permeability of the topsheet, there is little liquid return.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an example of a disposable diaper as an embodiment of the absorbent article of the present invention, and is a schematic plan view of the skin side (top sheet side) showing a state in which the elastic members of each part are stretched and spread out into a flat shape. be. 2 is a schematic cross-sectional view taken along line II-II in FIG. 1. FIG. It is a schematic perspective view which expands and shows a part of top sheet in the said disposable diaper. FIG. 2 is a schematic partially enlarged cross-sectional view of the topsheet for explaining the configuration of convex portions of the topsheet. FIG. 2 is a schematic partial enlarged view showing the skin of a wearer wearing an absorbent article and the surface portion of a topsheet. FIG. 2 is a schematic partial enlarged view showing the top sheet, intermediate sheet, and vicinity of the absorbent body of the absorbent article, and is a diagram illustrating the trend of liquid from the wearer. FIG. 3 is a diagram showing the physical properties of the nonwoven fabric layers of Examples 1 and 2. FIG. 3 is a diagram showing the physical properties of the nonwoven fabric layers of Comparative Examples 1 and 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The absorbent article of the present invention will be described below with reference to the drawings, taking a disposable diaper as an example as an embodiment.
<Overall composition of disposable diapers>
As shown in FIG. 1, the disposable diaper 1 of this embodiment is a so-called expandable disposable diaper. The disposable diaper 1 has a vertical direction X corresponding to the front-back direction of the wearer and a lateral direction Y corresponding to the left-right direction of the wearer and orthogonal to the vertical direction X. Furthermore, the disposable diaper 1 has a thickness direction Z that is orthogonal to both the longitudinal direction X and the lateral direction Y. In this specification, when each structure is viewed from the thickness direction Z, it is referred to as a plan view. In addition, in this specification, the skin side in each structure refers to the side located on the wearer's skin side when wearing a disposable diaper. In each configuration, the non-skin side refers to the side opposite to the wearer's skin side when wearing a disposable diaper. Regarding the thickness direction Z, the side closer to the wearer's skin when worn is sometimes referred to as the top, and the side closer to clothing is sometimes referred to as the bottom. The disposable diaper 1 is hereinafter referred to as the diaper 1.

The diaper 1 has a ventral region A located on the ventral side in the longitudinal direction, a dorsal region B located on the dorsal side in the longitudinal direction, and an inseam region C located between the ventral region A and the dorsal region B. It is divided into .
The dorsal region B includes side portions that protrude outward from the crotch region C in the left and right lateral directions Y. A fastening tape 6 is provided at the side edge in the lateral direction Y of the side part. Similarly, the ventral region A includes side portions that protrude outward from the crotch region C in the left and right lateral directions Y. A landing tape (not shown) for adhering the fastening tape 6 is provided on the non-skin side of the ventral region A. When worn, the dorsal region B and the ventral region A are adhered to each other by the fastening tape 6 and are placed together around the waist and waist of the wearer.
The crotch area C is narrower than the ventral area A and the dorsal area B, and has leg loops that are narrowed inward in the lateral direction Y, so that when worn, the crotch area includes the wearer's urinary area, anus, etc. placed in the department.
Note that "when worn" here refers to a state in which the normally assumed appropriate wearing position is maintained.

As shown in FIGS. 1 and 2, the diaper 1 includes a top sheet 2, a back sheet 3, an absorbent body 4, a side sheet 5, a pair of fastening tapes 6, an intermediate sheet 7, and a leak-proof sheet 8. , has. The diaper 1 has a structure in which a back sheet 3, a leak-proof sheet 8, an absorbent body 4, an intermediate sheet 7, and a top sheet 2 are laminated in the thickness direction Z. These structures are joined together by known joining means, such as hot melt adhesive.

The absorbent body 4 extends along the longitudinal direction X and is disposed between the top sheet 2 and the back sheet 3. That is, the absorbent body 4 is arranged on the non-skin side of the topsheet 2. The absorbent body 4 absorbs liquid excrement (hereinafter sometimes simply referred to as "liquid") such as the wearer's urine from the surface on the topsheet 2 side, diffuses it inside, and retains the liquid.
The absorbent core 4 includes an absorbent core 40 and a core wrap sheet 41.
The absorbent core 40 is mainly composed of an absorbent material capable of retaining liquid. Specifically, the absorbent core 40 has a structure such as a stack of hydrophilic fibers, a structure in which the fiber stack carries an absorbent polymer, or a structure consisting only of a water-absorbing polymer.
The core wrap sheet 41 has a function of covering the absorbent core 40 and, for example, maintaining the shape of the absorbent core 40. The core wrap sheet 41 is made of, for example, thin and soft paper such as tissue paper, liquid-permeable nonwoven fabric, or the like.

The top sheet 2 is placed on the wearer's skin side. The top sheet 2 is disposed on the skin side (upper part in the thickness direction Z) of the absorbent body 4, and forms, for example, the center portion of the skin side of the diaper 1 in the lateral direction Y. The top sheet 2 is configured as a liquid-permeable sheet material, and is formed of a nonwoven fabric made of synthetic fibers or natural fibers. Details of the top sheet 2 will be described later.

The intermediate sheet 7 is arranged between the top sheet 2 and the absorbent core 4. For the intermediate sheet 7, nonwoven fabrics obtained by various manufacturing methods can be used. The intermediate sheet 7 is arranged from the viewpoint of improving the permeability of liquid from the topsheet 2 to the absorbent body 4 and preventing liquid absorbed by the absorbent body 4 from returning to the topsheet 2. Details of the intermediate sheet 7 will be described later.

The back sheet 3 is arranged on the non-skin side (downward in the thickness direction Z) of the absorbent body 4, and constitutes, for example, almost the entire non-skin side of the diaper 1, and constitutes the exterior of the diaper 1 when worn. It is preferable that the back sheet 3 has leak-proof properties, and is formed of a sheet material having functions such as low liquid permeability, water vapor permeability, and water repellency, for example.

The pair of side sheets 5 are arranged on the lateral Y sides of the top sheet 2, and constitute, for example, the lateral Y sides of the skin side of the diaper 1. The side sheet 5 is desirably leak-proof, and is formed of a sheet material having functions such as low liquid permeability, water vapor permeability, and water repellency, for example. In the pair of side sheets 5, the center portion in the lateral direction Y is arranged to overlap the top sheet 2, and the side portion in the lateral direction Y extends to the outside of the top sheet 2 and is joined to the back sheet 3.
In the diaper 1, the side sheet 5 constitutes a sheet for forming three-dimensional gathers. The side end portion of the side sheet 5 on the center side in the lateral direction Y, at least in the crotch region C, is a free end portion that is not joined to the topsheet 2 or the like, and an elastic member 51 is disposed thereon. The elastic member 51 may extend in the vertical direction X in the crotch region C, and may extend to part of the ventral region A and the dorsal region B, for example. By providing the elastic member 51, a three-dimensional gather is constructed.
For example, by disposing an elastic member 52 that expands and contracts in the vertical direction X near the side end on the outer side of the side sheet 5 in the lateral direction Y, leg gathers that fit around the wearer's legs when worn are configured. .
The elastic members 51 and 52 are thread-like or band-like elastic members that can be expanded and contracted in the vertical direction X.

The pair of fastening tapes 6 have a fastening part 61 made of a male member of a mechanical hook-and-loop fastener. A landing tape made of a female member of a mechanical hook-and-loop fastener is provided on the non-skin side of the ventral region A of the diaper 1. A fastening portion 61 of the fastening tape 6 can be detachably fastened to the landing tape.

The leak-proof sheet 8 is made of a liquid-impermeable or slightly liquid-permeable resin film, and covers the skin side of the back sheet 3.

<Surface sheet>
[Structure of top sheet]
As shown in FIGS. 2 to 4, the topsheet 2 is constructed by laminating a lower layer 22 and an upper layer 21 formed on the lower layer 22. The upper layer 21 is composed of a three-dimensional nonwoven fabric layer (hereinafter simply referred to as "nonwoven fabric layer") having a structure in which a plurality of convex portions 23 are spaced apart from each other. The convex portion 23 protrudes in a dome shape toward the wearer's skin. The upper layer 21 and the lower layer 22 are partially bonded and fixed at a number of bonding portions 24 by heat fusion. The joint portion 24 forms the base of the top sheet 2 having a plurality of convex portions spaced apart from each other. Note that when the joint portion 24 is formed by embossing, a depression (recess) is formed in a part of the base, and the boundary between the protrusion 23 and the recess becomes the base of the protrusion 23 . A non-bonded portion of the upper layer 21 other than the bonded portion 24 forms a convex portion 23 . The inside of the convex portion 23 is hollow. The upper layer 21 has a skin side 21a located on the wearer's skin side when the diaper 1 is worn, and a non-skin side 21b opposite to the skin side 21a.
The convex portions 23 and the concave joint portions 24 are arranged alternately in rows in one direction (vertical direction X in FIG. 3), and such rows are arranged in a direction perpendicular to the one direction. They are formed in multiple rows in the horizontal direction (Y in FIG. 3).
As shown in FIG. 4, the convex portion 23 has a top portion 26 and a shoulder portion 27. As shown in FIG. In the specification, the top portion 26 of the convex portion 23 refers to a portion above 1/2 of the entire height of the convex portion 23 in the thickness direction Z of the topsheet 2. The shoulder portion 27 of the convex portion 23 refers to a lower portion that is 1/2 or less of the entire height of the convex portion 23 in the thickness direction Z. In the diaper 1, the entire height of the convex portion 23 refers to the height from the upper surface of the joint portion 24 to the top of the convex portion 23 in the thickness direction Z.

The upper layer 21 and the lower layer 22 are each made of a sheet of fibrous material. This sheet material is substantially non-stretchable. As the sheet-like material, various nonwoven fabrics can be used, such as a nonwoven fabric manufactured by a card method, a spunbond nonwoven fabric, a meltblown nonwoven fabric, a spunlace nonwoven fabric, a needle punched nonwoven fabric, a meltblown nonwoven fabric, a spunlace nonwoven fabric, and a needle punched nonwoven fabric. .

The top sheet 2 having a laminated structure in which the upper layer 21 and the lower layer 22 are partially joined by heat fusion at the joining portion 24 and has a plurality of convex portions 23 can be manufactured by, for example, the manufacturing method described in JP-A No. 2004-174234. It can be manufactured using
That is, by inserting a sheet of nonwoven fabric, which will become the upper layer 21, between two mutually meshing gear rolls having an uneven shape on the circumferential surface, the sheet-like material is intermittently stretched and subjected to the uneven shaping process. will be done. In the sheet-like material that has been textured in this way, the stretched portion constitutes the convex portion 23 . On the other hand, the unstretched portion constitutes the joint portion 24 when used as the top sheet 2. The sheet-like material that will become the upper layer 21 on which a plurality of convex portions 23 are formed is superimposed on the sheet-like material that will become the lower layer 22, and the superimposed product is placed between two sheets, at least one of which is heated to a predetermined temperature. It is compressed between rolls and partially joined. As a result, the upper layer 21 and the lower layer 22 are partially joined by heat fusion at the joining portion 24, and the top sheet 2 is manufactured. The surface of the top sheet 2 on the upper layer 21 side has irregularities. On the other hand, the surface of the topsheet 2 on the lower layer 22 side is substantially flat.
The convex portion 23 of the upper layer 21 manufactured in this manner has a structure in which the fiber density is greater in the shoulder portion 27 than in the top portion 26 due to the stretching process. As shown in FIG. 5, when the diaper 1 is worn, the wearer's skin 9 is mainly contacted by the tops 26 of the convex portions 23. In the convex portion 23, since the fiber density of the top portion 26 is relatively low, the surface of the top sheet 2 that comes into contact with the wearer's skin can be made soft. This improves the feel of the diaper and also suppresses the occurrence of skin problems such as redness on the skin 9 covered by the diaper 1 due to friction with the top sheet 2 and the like. In addition, the joint portion 24 has a higher fiber density than the convex portion 23, easily draws in liquid, and has high liquid absorbency.

[Physical properties of top sheet]
The physical properties related to the hydrophilicity and hydrophobicity of the upper layer 21 and the lower layer 22 that constitute the top sheet 2, which will be explained below, can be adjusted by the type of fiber treatment agent, the type and amount of the skin care agent to be included, the method of applying the skin care agent, etc. I can do it.
Skin care agents exhibit skin care effects. "Skin care effect" refers to the overall effect of normalizing the skin condition, such as preventing skin irritation, anti-inflammation, preventing damage, and antibacterial activity. In this embodiment, the skin care agent not only provides skin care effects to the wearer, but also adjusts the physical properties related to the hydrophilicity and hydrophobicity of the lower layer 22 and the nonwoven fabric layer having a plurality of convex portions 23 that constitute the upper layer 21 of the top sheet 2. used for.

The contact angle with physiological saline (0.9% NaCl aqueous solution) on the convex portions 23 of the top sheet 2 is larger at the top portion 26 than at the shoulder portion 27 . In this specification, the "contact angle with physiological saline" is simply referred to as the contact angle, and the contact angle with water (ion-exchanged water) is simply referred to as the "contact angle with water." That is, the convex portion 23 has a shoulder portion 27 that has relatively high hydrophilicity (has a small contact angle) with respect to the top portion 26, and a top portion that has relatively low hydrophilicity (has a large contact angle) with respect to the shoulder portion 27. It has 26. In other words, the top portion 26 exhibits higher hydrophobicity than the shoulder portion 27, and the shoulder portion 27 exhibits higher hydrophilicity than the top portion 26.
As a result, liquid from the wearer preferentially adheres to the shoulder portion 27, which has relatively high hydrophilicity, and easily migrates from the shoulder portion 27 into the convex portion 23, improving the liquid permeability of the top sheet 2. It can be made into something. Moreover, since the top portion 26 has relatively high hydrophobicity, liquid return is suppressed. That is, the liquid absorbed into the top sheet 2 returns to the skin side due to pressure from the wearer in a sitting position, for example, so-called liquid return occurs. However, in the top sheet 2 of this embodiment, the top portion 26 that mainly contacts the wearer's skin has high hydrophobicity, so the top portion 26 suppresses the liquid absorbed by the top sheet 2 from returning to the skin side. The amount of liquid returned can be reduced. By suppressing liquid return, hydration of the skin is suppressed, and the occurrence of skin troubles such as redness of the skin inside the diaper 1 is suppressed.

From the viewpoint of further achieving the above-mentioned effects, the difference in the contact angle between the top part 26 and the shoulder part 27 of the convex part 23 is preferably 2 degrees or more, particularly preferably 5 degrees or more, as the former minus the latter, before liquid passage. The angle is preferably 70° or less, more preferably 30° or less.

Furthermore, in the top sheet 2 of this embodiment, the contact angle of the top portion 26 of the convex portion 23 of the upper layer 21 changes before and after passing the liquid, and is larger after passing the liquid. On the other hand, the contact angle of the shoulder portion 27 of the convex portion 23 changes before and after liquid passage, and is smaller after liquid passage than before liquid passage.
In such a configuration, the top portion 26 of the convex portion 23 becomes more hydrophobic and the shoulder portion 27 changes over time so that it becomes more hydrophilic due to fluid passage such as urination.
By making the shoulder portion 27 more hydrophilic through liquid passage, liquid from the wearer can be stably and efficiently absorbed from the shoulder portion 27 into the topsheet 2 even when the diaper 1 is used for a long time. The liquid permeability of the topsheet 2 can be maintained. Furthermore, by increasing the hydrophobicity of the top portion 26 by passing liquid through it, the effect of suppressing liquid return can be maintained even when the diaper 1 is used for a long time.
Therefore, the diaper 1 equipped with the topsheet 2 having the nonwoven fabric layer (upper layer) having the above-mentioned physical properties can maintain good liquid permeability of the topsheet 2 and prevent liquid return even during long-term use. It can be made smaller. By suppressing liquid return, hydration of the skin is suppressed, and the occurrence of skin troubles such as redness of the skin inside the diaper 1 is suppressed.
Here, "liquid passing" refers to supplying liquid of the wearer's excrement such as urine to the top sheet 2.

From the viewpoint of further achieving the above-mentioned effects, the contact angle of the top portion 26 of the convex portion 23 after passing the liquid is preferably 2° or more larger than the contact angle before the liquid passing, more preferably 8° or more larger, and , 40° or less, more preferably 20° or less.
From the same viewpoint, the contact angle of the shoulder portion 27 of the convex portion 23 after liquid passage is preferably 1° or more smaller, more preferably 5° or more smaller than the contact angle before liquid passage. is smaller by 30° or less, more preferably smaller by 20° or less.

In the top sheet 2 having a laminated structure, the density of the skin care agent in the upper layer 21 is preferably higher than that in the lower layer 22. In this way, by increasing the density of the skin care agent in the upper layer 21 located closer to the wearer's skin, the skin transfer rate of the skin care agent can be increased, and the skin care agent can be used more efficiently.

In the topsheet 2 having a laminated structure, the contact angle of the lower layer 22 is preferably smaller than that of the shoulder portions 27 of the convex portions 23 of the upper layer 21 . In other words, the contact angle of the shoulder portion 27 of the convex portion 23 of the upper layer 21 is larger than that of the lower layer 22 and smaller than that of the top portion 26 . Thereby, liquid from the wearer is more easily absorbed by the lower layer 22 than by the upper layer 21, and the liquid transfers to the absorbent body 4 more quickly. Therefore, the liquid permeation characteristics of the topsheet 2 become better, and the effect of suppressing liquid return is further improved.

From the viewpoint of further achieving the above-mentioned effects, the contact angle of the lower layer 21 is preferably 2° or more smaller than the shoulder portion 27 of the convex portion 23, more preferably 5° or more smaller, and the upper limit is 70°. It is preferably at most 50°, more preferably at most 50°.

The upper layer 21 having a plurality of convex portions 23 has physical properties such that the contact angle of the shoulder portion 27 is smaller than that of the top portion 26 and the contact angle of the top portion 26 and the shoulder portion 27 before and after liquid passage changes as described above. It can be manufactured by adjusting the type of fiber treatment agent used, the type and amount of the skin care agent to be included, the method of applying the skin care agent, etc.
In addition, the lower layer 22 has physical properties such that the contact angle of the shoulder portion 27 of the convex portion 23 of the upper layer 21 is larger than that of the lower layer 22 and smaller than that of the top portion 26. etc. can be adjusted and manufactured.
An example of a method for manufacturing the top sheet 2 will be described later.

[Contact angle, fiber density, density of skin care agent]
Specific numerical values of the contact angle and fiber density will be listed below, but these are just examples and are not limited thereto.
The contact angle θ1 of the top portion 26 before liquid passage is preferably 130° or more, more preferably 135° or more, and preferably 170° or less, more preferably 165° or less, and more specifically, 130° or more. The angle is preferably 170° or less, and more preferably 140° or more and 165° or less.
The contact angle θ2 of the shoulder portion 27 before liquid passage is preferably 90° or more, more preferably more than 90°, even more preferably 95° or more, and preferably 130° or less, more preferably 125° or less, and more. Specifically, the angle is preferably 90° or more and 130° or less, more preferably more than 90° and 130° or less, and even more preferably 95° or more and 125° or less.
The contact angle θ1' at the top 26 after passing the liquid is preferably 140° or more, more preferably 145° or more, and preferably 170° or less, on the premise that it is larger than the contact angle θ1 before the liquid passing. More preferably, the angle is 165° or less, more specifically, it is preferably 140° or more and 170° or less, and even more preferably 145° or more and 165° or less.
The contact angle θ2' at the shoulder portion 27 after liquid passage is 90° or more, more preferably 95° or more, and preferably 140°, on the premise that it is smaller than the contact angle θ2 before liquid passage. Hereinafter, the angle is more preferably 135° or less, more specifically, it is preferably 90° or more and 140° or less, and even more preferably 95° or more and 135° or less.
The contact angle θ3 of the lower layer before liquid passage is preferably 50° or more, more preferably 55° or more, and preferably 85° or less, more preferably 80° or less, and more specifically, 50° or more and 85°. The angle is preferably 55° or more and 80° or less, more preferably 55° or more and 80° or less.
The method for measuring the contact angle will be described later.

The fiber density value of the top portion 26 of the convex portion 23 of the upper layer 21 is 30 fibers/mm ² or more and 130 fibers/mm ² or less, preferably 50 fibers/mm ² or more and 120 fibers/mm ² or less.
The fiber density value of the shoulder portion 27 is 80 fibers/mm ² or more and 250 fibers/mm ² or less, preferably 90 fibers/mm ² or more and 240 fibers/mm ² or less.
The fiber density value of the concave portion, which is the joint portion 24, is 250 fibers/mm ² or more and 500 fibers/mm ² or less, preferably 270 fibers/mm ² or more and 480 fibers/mm ² or less.
The method for measuring fiber density will be described later.

The density of the skin care agent in the upper layer is 3 μg/cm ³ or more and 500 μg/cm ³ or less, preferably 4 μg/cm ³ or more and 300 μg/cm ³ or less.
The density of the skin care agent in the lower layer is 3 μg/cm ³ or more and 500 μg/cm ³ or less, preferably 4 μg/cm ³ or more and 300 μg/cm ³ or less.
A method for measuring the density of skin care agents will be described later.

<Skin care agent>
As the skin care agent, hydrophobic skin care agents, hydrophilic skin care agents, etc. can be used.
A hydrophobic skin care agent is a hydrophobic ingredient that has no water solubility or water dispersibility, or has extremely low solubility, and has a composition that has protective, healing, etc. effects on the wearer's skin. A substance or compound. More specifically, a hydrophobic component refers to a component that dissolves in an amount of less than 1 g when 10 g of the component agent is mixed in 1 L of ion-exchanged water and left to stand for 24 hours, preferably 0.1 g or less. Particularly preferred is one that does not dissolve completely.
Examples of hydrophobic skin care agents include fatty acids with a carbon chain length of 12 to 28 or ester compounds of the fatty acids and glycerin, waxes, petrolatum, etc. In particular, unsaturated fatty acids with a carbon chain length of 12 to 28 or unsaturated fatty acids. It is preferable that the glycerin ester compound contains a glycerin ester compound. The glycerin ester is a monoester, diester or triester of glycerin and the above-mentioned unsaturated fatty acid, and a triester is particularly preferred. As agents containing fatty acids or fatty acid compounds, natural product extracts such as argan oil and shea butter can be preferably used. In particular, argan oil, a hydrophobic vegetable oil containing unsaturated fatty acids, functions as a skin care agent by maintaining the balance of water and oil in the skin and preventing dryness. Furthermore, argan oil contains a large amount of unsaturated fatty acids such as oleic acid and linoleic acid, and has a strong ability to remove active oxygen, so it can reduce skin damage caused by sunburn, for example.

On the other hand, hydrophilic skin care agents are hydrophilic ingredients that are water-soluble or water-dispersible, and suppress the occurrence of rashes and inflammation, and if rashes or inflammation occur, they can prevent the progression of the rash or inflammation. It is preferable that the agent be capable of suppressing the irritation or alleviating the irritation or inflammation. More specifically, the hydrophilic component refers to a component that dissolves or disperses in an amount of 1 g or more when 10 g of the component agent is mixed in 1 L of ion-exchanged water and left to stand for 24 hours, preferably 5 g. The amount of dissolution or dispersion is above, more preferably 1 g or more, still more preferably 5 g or more, and most preferably completely soluble.
As the hydrophilic skin care agent, natural extracts such as peach leaf extract and Hamamelis extract, polyhydric alcohols with 2 to 4 carbon atoms, polyethylene glycol, hydrophilic compounds with skin care functions, etc. can be used. .
Among these, peach leaf extract (hydrophilic extract), which is a plant extract, is preferred because it has antibacterial and anti-inflammatory effects. The peach leaf extract, which is a hydrophilic component, dissolves in the liquid supplied to the top sheet 2 and transfers to the skin, producing a skin care effect.
The polyhydric alcohol having 2 to 4 carbon atoms is a hydrophilic component and is typically 1,3-butylene glycol. By using 1,3-butylene glycol, the moisturizing effect and lubricity are improved. By improving the lubricity, friction between the skin and the nonwoven fabric can be reduced, and damage to the skin can be suppressed. 1,3-Butylene glycol is a liquid, water-soluble base ingredient with moisturizing properties that feels smooth and less sticky, keeping your skin moisturized. 1,3-Butylene glycol is used not only as a humectant but also as a solvent. For example, when peach leaf extract is used as a skin care agent, 1,3-butylene glycol can be used as a solvent for peach leaf extract. Although 1,3-butylene glycol has been taken as an example here, any polyhydric alcohol having 2 to 4 carbon atoms will exhibit the same effect; for example, propylene glycol may also be used. Propylene glycol can also be used as an extraction solvent for peach leaf extract (hydrophilic extract).

The various skin care agents mentioned above may be used alone or in combination. For example, at least two types of skin care agent components having different degrees of hydrophilicity and hydrophobicity may be used. As a result, the timing at which the skin care effect is exerted can be shifted according to the dry state before urination, the change in the degree of wetness due to urination, sweating, etc., and the skin care effect can be sustained for a long time.
When using at least two types of skin care agent components having different degrees of hydrophilicity and hydrophobicity, it is more preferable to include a hydrophilic skin care agent (hydrophilic component) and a hydrophobic skin care agent (hydrophobic component). As a result, in the dry state before urination, the hydrophobic skin care agent easily transfers to the skin, and in the wet state after urination, the hydrophilic skin care agent eluted into the liquid when the liquid returns is likely to transfer to the skin. Therefore, the skin care effect can be sustained for a long time after the diaper 1 starts being worn, and the occurrence of skin troubles can be further suppressed.

It is preferable to use natural product extract components in the skin care agent. For example, since the skin of an infant who wears the diaper 1 is thinner than that of an adult and has a poorer barrier function, the use of natural product extracts suppresses the occurrence of allergic reactions and the like. Furthermore, by using natural product extracts, skin problems such as redness of the skin inside the diaper are less likely to occur.

The preferred content per unit area of the skin care agent disposed in the nonwoven fabric layer is as follows. The hydrophilic skin care agent is preferably 0.1% by mass or more and 150% by mass or less based on the fiber mass from the viewpoint of further enhancing the effect of the present invention, and 0.2% by mass or more and 50% by mass from the viewpoint of balance with the feeling of use. The following are preferred. In addition, the present invention provides that the hydrophobic skin care agent is 1 x 10 ^-4 mass % or more and 0.5 mass % or less, particularly 2 x 10 ^-4 mass % or more and 0.1 mass % or less, based on the fiber mass. It is preferable because it is easy to balance the effect and feeling of use.

The hydrophilic oil agent (fiber treatment agent) described in the manufacturing method described below is a solid lipid-like active agent mass at 36°C. On the other hand, hydrophobic skin care agents such as argan oil and hydrophilic skin care agents such as peach leaf extract and 1,3-butylene glycol are liquid at 36°C. By using a hydrophilic oil agent, a liquid hydrophobic skin care agent or a hydrophilic skin care agent can be stably attached to fibers.

<Intermediate sheet>
As shown in FIG. 6, the intermediate sheet 7 has a first surface 71 located on the wearer's skin side and a second surface 72 opposite to the first surface 71.
The fiber density of the intermediate sheet 7 made of a hydrophilic nonwoven fabric is distributed in the thickness direction Z, and is smaller on the first surface 71 side than on the second surface 72 side. The higher the fiber density (higher fiber density), the greater the liquid drawing force by the capillaries. By configuring it to be lower, liquid from the wearer that has migrated from the top sheet 2 to the intermediate sheet 7 is drawn toward the second surface 72, and the liquid is transferred to the first surface 71 side of the intermediate sheet 7. It becomes difficult to stay. Thereby, the elution of the skin care agent from the top sheet 2 to the intermediate sheet 7 due to liquid residue after urination is suppressed, and the skin care agent can be ensured to transfer to the skin, thereby making it possible to maintain the skin care effect.

Further, the intermediate sheet 7 and the top sheet 2 are bonded and fixed by a first adhesive 11 made of a hot melt adhesive or the like arranged on the first surface 71. The intermediate sheet 7 and the absorbent body 4 are bonded and fixed by a second adhesive 12 made of a hot melt adhesive or the like arranged on the second surface 72.
The first adhesive 11 is applied intermittently so as not to interfere with the smooth transfer of the liquid from the top sheet 2 to the intermediate sheet 7 and to create non-applied areas. The second adhesive 12 is disposed intermittently so as not to impede the smooth transfer of the liquid from the intermediate sheet 7 to the absorbent body 4 and to create non-applied areas of the adhesive. Each of the first adhesive 11 and the second adhesive 12 is disposed intermittently in the horizontal direction Y and in a plurality of strips along the vertical direction X, for example.
The coating area ratio of the first adhesive 11 is lower than the coating area ratio of the second adhesive 12. Specifically, the coating area ratio of the first adhesive 11 is preferably 5% or more and 50% or less, and more preferably 7% or more and 30% or less. The coating area ratio of the second adhesive 12 is preferably 10% or more and 65% or less, and more preferably 13% or more and 50% or less. The method for measuring the coating area ratio will be described later.
Further, the second adhesive 12 overlaps at least a portion of the shoulder portion 27 of the convex portion 23 in a plan view.

Since the coating area ratio of the first adhesive 11 is lower than the coating area ratio of the second adhesive 12, the transfer of liquid from the intermediate sheet 7 to the absorbent body 4 is prevented from occurring on the top sheet 2. The transfer of the liquid from the absorbent body 4 to the intermediate sheet 7 is slower than that of the liquid, and the liquid is stored once in the intermediate sheet 7 before being absorbed into the absorbent body 4. Furthermore, in this embodiment, the shoulder portion 27 of the top sheet 2 and the second adhesive 12, which easily absorb liquid from the wearer, overlap in plan view, so that the shoulder portion 27, which easily absorbs liquid from the wearer, overlaps with the second adhesive 12, as shown by the arrow in FIG. The liquid absorbed from the portion 27 is prevented from transferring to the absorbent body 4 by the second adhesive 12 located immediately below, and spreads laterally in the drawing, and before being absorbed by the absorbent body 4, the liquid is transferred to the intermediate sheet 7. It is in a form that is easy to store. As a result, when the liquid once stored in the intermediate sheet 7 returns, the hydrophilic skin care agent is eluted into the liquid and the skin care agent is transferred to the skin, so the skin care agent can be used efficiently and has skin care effects. can be sustained.

[Method for manufacturing top sheet]
A specific method for manufacturing a topsheet having the above-mentioned physical properties will be explained. The top sheet 2 of this embodiment is produced by overlapping an upper layer 21 manufactured by the manufacturing method of the first to sixth examples described below and a lower layer 22 manufactured by the manufacturing method described later, and partially separating them by the method described above. It can be manufactured by directly bonding. By the manufacturing methods of the first to sixth examples described later, the contact angle of the shoulder portion 27 is smaller than that of the top portion 26, and the contact angle of each of the top portion 26 and the shoulder portion 27 before and after liquid passage changes as described above. A nonwoven fabric layer (upper layer) having a plurality of convex portions 23 can be manufactured. Note that the manufacturing method is not limited to these.
As raw material fibers for the upper layer 21 and the lower layer 22, core-sheath fibers, side-by-side fibers, etc. can be preferably used, and core-sheath fibers are particularly preferred. A typical fiber has a core component of PET (polyethylene terephthalate) and a sheath component of PE (polyethylene), and preferably has a core-sheath ratio of 20/80 to 80/20 by mass. The fineness of the fiber is preferably 1.5 dtex or more and 5.0 dtex or less. Note that the core/sheath ratio indicates the mass ratio (core/sheath) of the resins constituting each of the core and sheath.

(1st example)
A sheet material made of nonwoven fibers coated with a treatment agent consisting of a mixture of a hydrophilic oil agent (fiber treatment agent), a hydrophilic skin care agent (hydrophilic component), and a hydrophobic skin care agent (hydrophobic component), A method of manufacturing a nonwoven fabric layer having a plurality of convex portions by applying the above-described unevenness processing is exemplified. During uneven machining, when the gear roll is engaged, the sheet material is pressed by the convex part of the roll and the corresponding convex part is formed, and the sheet-like material is stretched relatively strongly. is stretched relatively more strongly than the shoulder region. As a result, in the convex portions of the nonwoven fabric layer having a plurality of convex portions to be manufactured, the relative fiber density at the top portion is lower than that at the shoulder portions, and the density of the skin care agent is also lower than that at the shoulder portions.
In the convex portions 23 of the nonwoven fabric layer manufactured in this way, the density of the hydrophilic skin care agent is smaller in the top portions 26 than in the shoulder portions 27, and the contact angle of the top portions 26 is larger than that in the shoulder portions 27.
In addition, by using the nonwoven fabric layer manufactured in this way as the upper layer 21 of the top sheet 2 of the diaper 1, when the diaper 1 is worn, when liquid is supplied to the upper layer 21, the hydrophilic layer present in the top 26 The skin care agent (hydrophilic component) begins to dissolve in the liquid supplied to the top portion 26 and flows to the shoulder portion 27 together with the liquid. As a result, the top portion 26 becomes more hydrophobic, and the contact angle of the top portion 26 becomes larger after liquid passage than before liquid passage. On the other hand, the shoulder portion 27 becomes more hydrophilic, and the contact angle of the shoulder portion 27 becomes smaller after liquid passage than before liquid passage.
Further, in the nonwoven fabric layer manufactured in this manner, the density of the hydrophilic skin care agent is greater in the shoulder portion 27 than in the top portion 26. Thereby, in the topsheet 2, absorption of liquid from the shoulder portion is performed more quickly, and liquid permeability can be improved.
Note that the "hydrophilic oil agent" is a fiber treatment agent that makes the fiber surface hydrophilic, and is a hydrophilic component, and any known one can be used. Furthermore, when peach leaf extract is used as a hydrophilic skin care agent, 1,3-butylene glycol can be used as a solvent for peach leaf extract, and 1,3-butylene glycol can be used as a treatment agent containing skin care ingredients. It will be done.
Here, we have given an example in which fibers coated with a treatment agent containing skin care ingredients are made into a non-woven fabric. The nonwoven fabric layer may be manufactured by coating the entire surface with a treatment agent containing a skin care agent. In this case, after applying the treatment agent, the nonwoven fabric is left to stand for a predetermined period of time (for example, 5 hours at room temperature) to spread the hydrophilic skin care agent and the hydrophobic skin care agent within the nonwoven fabric. Thereby, it is possible to produce a nonwoven fabric made of fibers coated with a treatment agent consisting of a mixture containing a hydrophilic oil, a hydrophilic skin care agent, and a hydrophobic skin care agent. Example 1, Example 2, and Comparative Example 1, which will be described later, were manufactured using this manufacturing method. A nonwoven fabric made from fibers coated with the above-mentioned hydrophilic oil agent is a hydrophilic nonwoven fabric.

(2nd example)
For example, a nonwoven fabric made of fibers uniformly coated with a hydrophilic oil agent may be textured by the method described above, and then a hydrophobic skin care agent may be spray-coated. By spray-coating the hydrophobic skin care agent on the textured nonwoven fabric, the hydrophobic skin care agent is concentrated on the top portion 26 of the convex portions. Note that a hydrophilic skin care agent may be mixed with the hydrophilic oil agent.
In the convex portions 23 of the nonwoven fabric layer manufactured in this manner, the density of the hydrophobic skin care agent is greater in the top portion 26 than in the shoulder portion 27, and the contact angle of the top portion 26 is larger than that in the shoulder portion 27.
In addition, by using the nonwoven fabric layer manufactured in this way as the upper layer 21 of the top sheet 2 of the diaper 1, when the diaper 1 is worn, when liquid is supplied to the upper layer 21, the hydrophilic layer present in the top 26 The skin care agent (hydrophilic component) begins to dissolve in the liquid supplied to the top portion 26 and flows to the shoulder portion 27 together with the liquid. As a result, the top portion 26 becomes more hydrophobic, and the contact angle of the top portion 26 becomes larger after liquid passage than before liquid passage. On the other hand, the shoulder portion 27 becomes more hydrophilic, and the contact angle of the shoulder portion 27 becomes smaller after liquid passage than before liquid passage.

(3rd example)
A method may be mentioned in which a nonwoven fabric made of fibers uniformly coated with a hydrophilic oil agent is textured by the method described above, and then a hydrophobic skin care agent is coated with a coater. By applying the hydrophobic skin care agent to the textured nonwoven fabric using a coater, the hydrophobic skin care agent is concentrated on the top portion 26 of the convex portions. Note that a hydrophilic skin care agent may be mixed with the hydrophilic oil agent.
In the convex portions 23 of the nonwoven fabric layer manufactured in this manner, the density of the hydrophobic skin care agent is greater in the top portion 26 than in the shoulder portion 27, and the contact angle of the top portion 26 is larger than that in the shoulder portion 27.
In addition, by using the nonwoven fabric layer manufactured in this way as the upper layer 21 of the top sheet 2 of the diaper 1, when the diaper 1 is worn, when liquid is supplied to the upper layer 21, the hydrophilic layer present in the top 26 The skin care agent (hydrophilic component) begins to dissolve in the liquid supplied to the top portion 26 and flows to the shoulder portion 27 together with the liquid. As a result, the top portion 26 becomes more hydrophobic, and the contact angle of the top portion 26 becomes larger after liquid passage than before liquid passage. On the other hand, the shoulder portion 27 becomes more hydrophilic, and the contact angle of the shoulder portion 27 becomes smaller after liquid passage than before liquid passage.

(4th example)
An example of this method is to use a gear roll onto which a hydrophilic skin care agent has been transferred to a hydrophobic nonwoven fabric to form concave and convex portions, thereby concentrating the hydrophilic skin care agent on the shoulder area. In the nonwoven fabric manufactured in this manner, the contact angle of the top portion 26 of the convex portion 23 is larger than that of the shoulder portion 27 . Furthermore, a hydrophobic skin care agent is applied to the top portion 26 of this nonwoven fabric to obtain a nonwoven fabric layer. Note that the hydrophobic nonwoven fabric is a nonwoven fabric manufactured from fibers uniformly coated with a hydrophobic oil agent.
By using the nonwoven fabric layer manufactured in this way as the upper layer 21 of the top sheet 2 of the diaper 1, when the diaper 1 is worn, when a liquid is supplied to the upper layer 21, the hydrophilic skin care present in the top part 26 is removed. The agent (hydrophilic component) begins to dissolve in the liquid supplied to the top part 26 and flows to the shoulder part 27 together with the liquid. As a result, the top portion 26 becomes more hydrophobic, and the contact angle of the top portion 26 becomes larger after liquid passage than before liquid passage. On the other hand, the shoulder portion 27 becomes more hydrophilic, and the contact angle of the shoulder portion 27 becomes smaller after liquid passage than before liquid passage.
Further, in the nonwoven fabric layer manufactured in this manner, the density of the hydrophilic skin care agent is greater in the shoulder portion 27 than in the top portion 26. Thereby, in the topsheet 2, absorption of liquid from the shoulder portion is performed more quickly, and liquid permeability can be improved.
Furthermore, by applying the skin care agent to the nonwoven fabric layer manufactured in this manner from the skin side, the density of the hydrophobic skin care agent is greater on the skin side than on the non-skin side. Thereby, when the diaper 1 is worn, the hydrophobic skin care agent is quickly transferred to the skin.

(5th example)
An example of this method is to apply a mixture of a hydrophobic skin care agent and a hydrophilic skin care agent to the tops of the protrusions after a nonwoven fabric made of fibers uniformly coated with a hydrophilic oil agent is processed into irregularities by the method described above. As a coating method, spray coating, coater coating, etc. can be used, and by these coating methods, a mixture of a hydrophobic skin care agent and a hydrophilic skin care agent is concentrated on the top portion 26 of the convex portion 23. It can be coated with
In the convex portions 23 of the nonwoven fabric layer manufactured in this manner, the density of the mixture of the hydrophobic skin care agent and the hydrophilic skin care agent is greater in the top portion 26 than in the shoulder portion 27. Therefore, in the convex portion 23, more hydrophobic skin care agent (hydrophobic component) is present in the top portion 26 than in the shoulder portion 27, and the contact angle of the top portion 26 is larger than that of the shoulder portion 27.
In addition, by using the nonwoven fabric layer manufactured in this way as the upper layer 21 of the top sheet 2 of the diaper 1, when the diaper 1 is worn, when liquid is supplied to the upper layer 21, the hydrophilic layer present in the top 26 The skin care agent (hydrophilic component) begins to dissolve in the liquid supplied to the top portion 26 and flows to the shoulder portion 27 together with the liquid. As a result, the top portion 26 becomes more hydrophobic, and the contact angle of the top portion 26 becomes larger after liquid passage than before liquid passage. On the other hand, the shoulder portion 27 becomes more hydrophilic, and the contact angle of the shoulder portion 27 becomes smaller after liquid passage than before liquid passage.
Further, in the nonwoven fabric layer manufactured in this way, by applying the skin care agent from the skin side, the density of the hydrophobic skin care agent is higher on the skin side than on the non-skin side. Thereby, when the diaper 1 is worn, the hydrophobic skin care agent is quickly transferred to the skin.

(6th example)
By applying the above-mentioned uneven processing to a sheet-like material made of a nonwoven fabric produced by overlapping a hydrophilic web containing a hydrophilic skin care agent and a hydrophilic oil agent and a hydrophobic web containing a hydrophobic skin care agent, multiple A method for manufacturing a nonwoven fabric layer having convex portions is mentioned. During uneven machining, when the gear roll is engaged, the sheet material is pressed by the convex part of the roll and the corresponding convex part is formed, and the sheet-like material is stretched relatively strongly. is stretched relatively more strongly than the shoulder region. As a result, in the convex portions of the nonwoven fabric layer having a plurality of convex portions to be manufactured, the relative fiber density at the top portion is lower than that at the shoulder portions, and the density of the skin care agent is also lower than that at the shoulder portions. The hydrophilic web may be produced by making fibers into a non-woven fabric and then coating them with a hydrophilic skin care agent and a hydrophilic oil agent, or by making the fibers coated with a hydrophilic skin care agent and a hydrophilic oil agent into a non-woven fabric. May be manufactured. The hydrophobic nonwoven fabric may be manufactured by forming fibers into a nonwoven fabric and then applying a hydrophobic skin care agent thereon, or may be manufactured by forming a fiber coated with a hydrophobic skin care agent into a nonwoven fabric. Note that the hydrophobic web may contain a hydrophilic oil agent (fiber treatment agent) in addition to the hydrophobic skin care agent.
When the nonwoven fabric layer manufactured in this way is used as the upper layer 21 of the topsheet 2, in the diaper 1, the hydrophilic web side constitutes the skin side 21a of the upper layer 21, and the hydrophobic web side constitutes the non-skin side 21b of the upper layer 21. The upper layer 21 is placed in the upper layer 21 .
In the convex portions 23 of the non-woven fabric layer which is thus textured and used as the upper layer 21 of the diaper 1, the density of the hydrophilic skin care agent present in the outermost layer is smaller in the top portion 26 than in the shoulder portion 27, The contact angle of the top portion 26 is larger than that of the shoulder portion 27.
In addition, by using the nonwoven fabric layer manufactured in this way as the upper layer 21 of the top sheet 2 of the diaper 1, when the diaper 1 is worn, when liquid is supplied to the upper layer 21, the hydrophilic layer present in the top 26 The skin care agent (hydrophilic component) begins to dissolve in the liquid supplied to the top portion 26 and flows to the shoulder portion 27 together with the liquid. As a result, the top portion 26 becomes more hydrophobic, and the contact angle of the top portion 26 becomes larger after liquid passage than before liquid passage. On the other hand, the shoulder portion 27 becomes more hydrophilic, and the contact angle of the shoulder portion 27 becomes smaller after liquid passage than before liquid passage.
Moreover, since the hydrophilic web side constitutes the skin side 21a of the upper layer 21 and the hydrophobic web side constitutes the non-skin side 21b of the upper layer 21, in the upper layer 21 of the topsheet 2, the skin side 21a exhibits hydrophilicity, and the non-skin side 21b exhibits hydrophobicity. Therefore, the contact angle of the non-skin side surface 21b is smaller than that of the skin side surface 21a. As a result, the hydrophilic skin care agent (hydrophilic component) present in the top portion 26 is easily dissolved by liquid from the wearer and transferred to the skin, which is efficient. Further, the liquid absorbed from the shoulder portion 27 into the top sheet 2 is suppressed from returning to the skin side by the hydrophobic non-skin side surface 21b, and the effect of suppressing liquid return can be efficiently expressed.
Moreover, here, an example was given in which a hydrophilic web and a hydrophobic web are overlapped and subjected to uneven processing to produce a nonwoven fabric layer. In addition, after a sheet-like material made of non-woven fabric is textured, a hydrophilic skin care agent is applied to the skin side of the top of the convex portion, and a hydrophobic skin care agent is applied to the non-skin side of the top. A nonwoven layer having multiple protrusions may be produced.

(Production example of lower layer)
The lower layer was constructed using a sheet-like material made of non-woven fibers coated with a hydrophilic oil agent and a hydrophilic skin care agent.

<Supplementary explanation>
[Method of measuring contact angle]
The contact angle of the top and shoulder portions of the convex portions of the topsheet can be measured as follows.
Measurements were performed using a Keyence Microscope VH-8000 with a medium magnification zoom lens (with illumination ring) tilted at 90° and set to 500x. The measurement sample used was a topsheet cut into a size of 150 mm in the vertical direction x 70 mm in the horizontal direction. The measurement environment was 20°C/50% RH, and the measurement sample was placed with the measurement surface (here, the surface with multiple convex portions) facing upward so that it could be observed from the CD direction of the web (nonwoven fabric). was set on the measurement stage. Next, 2 μl of physiological saline is applied to the top or shoulder of the protrusion of the set measurement sample using a micropipette, and an image is captured within 5 seconds (preferably 2 to 3 seconds) of the application. The reason why it is necessary to capture an image within a short time after adhesion is to prevent the adhering water droplets from being evaporated by the light emitted from the measuring section of the microscope and to prevent the contact angle from changing due to the oil agent. The contact angle was measured at 10 observation points where both ends or one end of the water droplet were clearly focused, and the average value thereof was defined as the "contact angle". The contact angle is measured by drawing a tangent line between a water droplet and a fiber on an image or a printed photograph, and using image analysis or a protractor.
Moreover, although the above measurement was performed using physiological saline, when measuring the "contact angle with water", the same measurement may be performed by changing the physiological saline to ion-exchanged water.
To measure the contact angle between the skin side and non-skin side of the upper layer (nonwoven fabric layer), the top sheet with a laminated structure is separated into the upper layer and the lower layer, and the separated upper layer is used as the measurement target, and the skin side and non-skin side are respectively measured. A measurement similar to the above measurement is performed on the measurement surface.
In measuring the contact angle of the lower layer, the same measurement as above is performed using the skin side of the lower layer separated from the top sheet 2 as the measurement surface.
The contact angle with physiological saline or water serves as an index indicating the degree of hydrophobicity or hydrophilicity of components such as fibers and intermediate sheets. It can be determined that the smaller the value of the contact angle with physiological saline or water, the higher the hydrophilicity of the fibers or constituents. Generally, the contact angle θ with water of fibers and structures that are classified as hydrophilic is less than 90° (in the present invention, 15° or more and less than 85°, particularly preferably 50° or more and 83° or less), and are classified as hydrophobic. The contact angle θ of the fiber or structure with water is more than 90° (in the present invention, 90° or more and 170° or less, particularly preferably 92° or more and 165° or less).
The hydrophilicity of the intermediate sheet can be determined from the contact angle obtained by performing a measurement similar to the above measurement using the skin side of the intermediate sheet as the measurement surface and replacing physiological saline with ion-exchanged water.

The measurement of the contact angle before and after passing the liquid is performed on the measurement target site by the above-mentioned measurement method before and after passing the liquid. The liquid passing conditions are as follows: With the nonwoven fabric to be measured placed on the absorbent body, 90 g of physiological saline is passed through the nonwoven fabric at a rate of 5.0 g/sec under non-pressurized conditions. . Physiological saline is supplied to the nonwoven fabric by using a silicone tube to guide the liquid outlet to 10 mm above the nonwoven fabric placed on the absorbent body, and using a liquid injection pump (MCP-J, manufactured by ISMATEC). As the absorbent body, the surface sheet was removed from a 2020 Kao Corporation Merries (registered trademark) tape type S size, and the resulting absorbent body was used. The supply amount of 90 g is based on the assumption of the average excretion amount of infants. Furthermore, the supply rate of 5.0 g/sec is based on the assumption that the urine excretion speed is the same as when an infant excretes urine.

In measuring the contact angle between the skin side and the non-skin side of the non-woven fabric layer, the contact angle between the skin side and the non-skin side of the non-woven fabric part constituting the convex part of the non-woven fabric layer (the upper layer in this embodiment) where the entire layer has a plurality of convex parts is measured. Each side is used as a measurement target, and the fibers located in the outermost layer of each side are taken out and measured.

[Method for measuring the density of skin care agents]
A method for measuring the density of the skin care agent contained in the top sheet will be explained.
A sample of the upper layer 21 consisting of a nonwoven fabric layer having a plurality of convex portions is cut out from the top sheet 2 to a predetermined size, and the sample is examined using a scanning electron microscope (for example, JCM-5100 (trade name) manufactured by JEOL Ltd.). )) was observed under magnification (for example, 150 to 500 times magnification), and the volumes of the top and shoulder portions were calculated from the area and thickness of the sample.
Collect 2 g of fibers from each of the top and shoulder areas, which are the areas to be measured, and place them in a predetermined container with a small opening at the bottom. Then, hold down the fibers with the lid, push the fibers to the bottom of the container, and remove the lid. 10 cc of ether as an extraction solvent for a hydrophobic skin care agent or 10 cc of a mixed solution of ethanol/methanol (1:1) as an extraction solvent for a hydrophilic skin care agent is added thereto, and the mixture is allowed to stand for 6 hours. Thereafter, the lid is placed on the lid again and the fibers containing the solution are pressed firmly to squeeze out the ether or ethanol/methanol component of the liquid contained in the fibers, and the squeezed liquid is poured into a weighing dish. Then, after removing the solvent by heating the weighing dish, the weight of this weighing dish was measured, and the amount of skin care agent was determined from the difference between the weight of the weighing dish and the weight of the original weighing dish before adding the liquid. The amount of skin care agent in the three samples was measured, and the average was taken as the amount of skin care agent adhered.
The density of the skin care agent was calculated from the volume calculated above and the amount of skin care agent adhered.
Note that hydrophobic skin care agents may be extracted with the ethanol/methanol extraction solvent, so if all the skin care agents contained in each fiber are extracted with the ethanol/methanol extraction solvent, extraction with ether may be necessary. There is no need to do this.

[Method of measuring fiber density]
A method for measuring the density of fibers constituting the topsheet 2 will be explained.
The cut surface of the top sheet 2 is observed under magnification (for example, 150 to 500 times) using a scanning electron microscope (for example, JCM-5100 (trade name) manufactured by JEOL Ltd.), and the Count the number of cross sections of fibers cut by the above cutting surface per fixed area (about 0.5 mm ² ). Next, it is converted to the number of cross sections of fibers per 1 mm ² and this is taken as the fiber density. Measurements are made at three locations, and the average is taken as the fiber density of the sample.
In measuring the fiber density of each of the top portion 26 and shoulder portion 27 of the convex portion 23, the hollow portion in the convex portion 23 where no fibers are present is not included.

[Method of measuring coating area ratio]
A method for measuring the coating area ratio of the first adhesive 11 and the second adhesive 12 will be explained.
After spraying toner on the entire surface of the intermediate sheet (skin side) and back surface (non-skin side) to color the adhesive, the intermediate sheet is cut to a predetermined size and the colored area is measured. The coated area ratio is obtained by dividing the measured area by the cut size. Measurements are made at three or more points, the average value of which is determined, and the coated area ratio is calculated.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.
For example, in the above embodiments, a disposable diaper is shown as an example of the absorbent article, but the absorbent article is not limited thereto. The absorbent article of the present invention may be, for example, a urine absorbing pad, a discharge sheet, a sanitary napkin, or the like. Absorbent articles generally include a liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-retaining absorbent body interposed between the two sheets.
Further, in the above embodiments, an example was given in which the top sheet has a laminated structure in which the upper layer consisting of a nonwoven fabric layer having a plurality of convex portions and the lower layer are overlapped. It may have a single layer structure consisting of one layer.
Moreover, in the above-mentioned topsheet 2, openings may be provided in the joint portion 24 where the upper layer 21 and the lower layer 22 are joined, located between the plurality of convex portions 23. The openings are holes that penetrate the topsheet 2 along the thickness direction Z. The opening is formed inside the outline of the joint portion 24 in plan view. By providing openings, the ability to draw liquid, etc. can be further improved. The openings can be formed, for example, by adjusting the temperature and pressure of hot embossing and ultrasonic embossing when joining the upper layer 21 and the lower layer 22 using an embossing roll.

<1>
An absorbent article comprising a top sheet disposed on the wearer's skin side and an absorbent body disposed on the non-skin side of the top sheet, the top sheet protruding toward the wearer's skin side. The nonwoven fabric layer has a structure in which a plurality of convex portions are spaced apart from each other, the nonwoven fabric layer contains a skin care agent, the convex portion has a top portion and a shoulder portion, and the top portion has a top portion and a shoulder portion. The contact angle with the saline is larger than that of the saline, the contact angle at the top part before and after passing the liquid is larger after passing the liquid than before passing the liquid, and the contact angle at the shoulder part before and after passing the liquid. is an absorbent article that is smaller after passing through the liquid than before passing through the liquid.
<2>
The absorbency according to <1>, wherein the nonwoven fabric layer has a skin side and a non-skin side opposite to the skin side, and the contact angle is smaller on the non-skin side than on the skin side. Goods.
<3>
The absorbent article according to <1> or <2>, wherein the nonwoven fabric layer contains a hydrophilic skin care agent, and the density of the hydrophilic skin care agent is greater in the shoulder portion than in the top portion.
<4>
The non-woven fabric layer has a skin side and a non-skin side opposite to the skin side, the non-woven fabric layer contains a hydrophobic skin care agent, and the hydrophobic skin care agent is present at a higher density than the non-skin side. The absorbent article according to any one of <1> to <3>, wherein the skin side is larger.
<5>
The absorbent article according to any one of <1> to <4>, wherein the topsheet includes an upper layer made of the nonwoven fabric layer and a lower layer made of a nonwoven fabric overlaid on the upper layer.
<6>
The absorbent article according to <5>, wherein the upper layer and the lower layer are partially fixed, and the convex portion is formed by a portion of the upper layer that is not fixed to the lower layer.
<7>
The absorbent article according to <5> or <6>, wherein the upper layer and the lower layer contain a skin care agent, and the density of the skin care agent in the upper layer is higher than that in the lower layer.
<8>
The absorbent article according to any one of <5> to <7>, wherein the contact angle is larger in the shoulder part than in the lower layer and smaller than in the top part.
<9>
The absorbent article according to any one of <1> to <8>, wherein the top portion has a lower fiber density than the shoulder portion.
<10>
The absorbent article according to any one of <1> to <9>, wherein the skin care agent contains at least two types of components having different degrees of hydrophilicity and hydrophobicity.
<11>
The absorbent article according to <10>, wherein at least one component contained in the skin care agent is hydrophilic.
<12>
The absorbent article according to any one of <1> to <11>, wherein the skin care agent is a natural product extract component.
<13>
The absorbent article according to any one of <1> to <12>, wherein the topsheet has openings between the plurality of convex portions.
<14>
The top sheet further includes an intermediate sheet made of a hydrophilic nonwoven fabric arranged on the non-skin side, and the intermediate sheet has a first surface located on the skin side and a second surface opposite to the first surface. The absorbent sheet according to any one of <1> to <13>, wherein the intermediate sheet has a fiber density lower on the first side than on the second side. Sex items.
<15>
The coating area ratio of the first adhesive arranged on the first surface of the intermediate sheet is higher than the coating area ratio of the second adhesive arranged on the second surface of the intermediate sheet. A plurality of the second adhesives are disposed intermittently on the second surface, and the second adhesive overlaps at least a portion of the shoulder portion of the convex portion in a plan view. The absorbent article according to <14>.
<16>
Any one of <1> to <15>, wherein the difference in the contact angle between the top part and the shoulder part of the convex part is 2° or more, preferably 5° or more as the former minus the latter, before liquid passage. The absorbent article according to any one of the above.
<17>
<16> The difference in the contact angle between the top part and the shoulder part of the convex part is 2° or more and 70° or less, preferably 5° or more and 30° or less, as the former minus the latter, before liquid passage. The absorbent article described in .
<18>
Any one of <1> to <17>, wherein the contact angle of the top of the convex portion after passing the liquid is greater than the contact angle before passing the liquid by 2° or more, preferably by 8° or more. The absorbent article described in .
<19>
According to <18>, the contact angle of the top of the convex portion after liquid passage is larger than the contact angle before liquid passage by 2° or more and 40° or less, preferably 8° or more and 20° or less. absorbent articles.
<20>
The contact angle of the shoulder portion of the convex portion after liquid passage is smaller than the contact angle before liquid passage by 1° or more, more preferably by 5° or more, <1> to <19>. The absorbent article according to any one of the above.
<21>
The contact angle of the shoulder portion of the convex portion after liquid passage is smaller than the contact angle before liquid passage by 1° or more and 30° or less, preferably 5° or more and 20° or less, <20> The absorbent article described in .
<22>
The absorbent article according to any one of <5> to <8>, wherein the contact angle of the lower layer is smaller than the shoulder portion of the convex portion by 2° or more, preferably by 5° or more.
<23>
The absorbent article according to <22>, wherein the contact angle of the lower layer is smaller than the shoulder portion of the convex portion by 2° or more and 70° or less, preferably 5° or more and 50° or less.
<24>
The absorbent article according to any one of <1> to <23>, wherein the contact angle at the top portion before liquid passage is 130° or more and 160° or less, preferably 140° or more and 155° or less.
<25>
The contact angle at the top after passing the liquid is 140° or more and 170° or less, preferably 145° or more and 165° or less, on the premise that it is larger than the contact angle at the top before passing the liquid. The absorbent article according to any one of items 1> to <24>.
<26>
The absorbent article according to any one of <1> to <25>, wherein the contact angle at the shoulder portion before liquid passage is 120° or more and 150° or less, preferably 125° or more and 145° or less. .
<27>
The contact angle at the shoulder portion after liquid passage is 90° or more and 140° or less, preferably 95° or more and 135° or less, provided that it is smaller than the contact angle at the shoulder portion before liquid passage. , the absorbent article according to any one of <1> to <26>.
<28>
The contact angle θ of the lower layer is 50° or more and 85° or less, preferably 55° or more and 80° or less, according to any one of <5> to <8>, <22>, and <23>. Absorbent articles.

<Example>
The present invention will be further explained below with reference to Examples. However, the scope of the present invention is not limited to such examples. In the following, peach leaf extract is used as a hydrophilic skin care agent, and argan oil is used as a hydrophobic skin care agent. As the raw material fiber, a core-sheath structural fiber is used in which the core component is PET (polyethylene terephthalate) and the sheath component is PE (polyethylene), the core-sheath ratio is 50% by mass: 50% by mass, and the fineness is 2.3 dtex.

[Example 1]
After the fibers coated with a known hydrophilic oil agent (fiber treatment agent) were made into a nonwoven fabric, a textured fabric was applied to obtain a nonwoven fabric. The nonwoven fabric was coated with 0.35% by mass of a hydrophilic oil agent. 0.25 g of the treatment liquid was sprayed onto the nonwoven fabric cut into a size of 10 cm x 10 cm, the treatment liquid was spread over the nonwoven fabric, and the nonwoven fabric was left to dry for 5 hours to obtain the nonwoven fabric of Example 1.
The treatment liquid used for the nonwoven fabric in Example 1 was a mixture of an argan oil-ethanol solution in which argan oil was dissolved in ethanol at a concentration of 10% by mass, and peach leaf extract at a mass ratio of 1:1.
The nonwoven fabric of Example 1 contains peach leaf extract, which is a hydrophilic skin care agent, and argan oil, which is a hydrophobic skin care agent, as skin care agents.
The contact angles at the top and shoulder portions of the convex portions of the nonwoven fabric of Example 1 before and after liquid passage were measured by the above measurement method. The measurement results are shown in FIG. 7(A). In FIG. 7(A), FIG. 7(B), FIG. 8(A), and FIG. 8(B) described later, the value of the contact angle θ/2 on the vertical axis corresponds to the value of 1/2 of the contact angle θ. do. The contact angle θ is the above-mentioned θ1, θ1', θ2, or θ2'. In the bar graphs in each figure, an open bar graph indicates the contact angle θ/2 before liquid passage, and a bar graph with hatching inside indicates the contact angle θ/2 after liquid passage.

[Example 2]
Spray 1.5 g of peach leaf extract onto a 10 cm x 10 cm piece of nonwoven fabric cut out with unevenness to which 0.35% by mass of the same hydrophilic oil agent as in Example 1 has been adhered, and spread the peach leaf extract over the nonwoven fabric. Thereafter, it was left to dry for 5 hours to obtain the nonwoven fabric of Example 2.
The nonwoven fabric of Example 2 contains peach leaf extract, which is a hydrophilic skin care agent, as a skin care agent.
The contact angles at the top and shoulder portions of the convex portions of the nonwoven fabric of Example 2 before and after liquid passage were measured by the above measurement method. The measurement results are shown in FIG. 7(B).

[Comparative example 1]
0.25 g of a 10% concentration argan oil-ethanol solution was sprayed onto a nonwoven fabric cut out into a 10cm x 10cm piece having irregularities to which 0.35% by mass of the same hydrophilic oil as in Example 1 was attached, and the nonwoven fabric was coated with argan oil. - The ethanol solution was spread, and then left to dry for 5 hours to obtain the nonwoven fabric of Comparative Example 1.
The nonwoven fabric of Comparative Example 1 contains argan oil, which is a hydrophobic skin care agent, as a skin care agent.
The contact angles at the top and shoulder portions of the convex portions of the nonwoven fabric of Comparative Example 1 before and after liquid passage were measured by the above measurement method. The measurement results are shown in FIG. 8(A).

[Comparative example 2]
A nonwoven fabric of Comparative Example 2 was prepared as a nonwoven fabric of Comparative Example 2, which was cut into a size of 10 cm x 10 cm and had irregularities to which 0.35% by mass of the same hydrophilic oil agent as in Example 1 was adhered.
The nonwoven fabric of Comparative Example 2 did not contain any skin care agent.
The contact angles at the top and shoulder portions of the convex portions of the nonwoven fabric of Comparative Example 2 before and after liquid passage were measured by the above measurement method. The measurement results are shown in FIG. 8(B).

[evaluation]
As shown in FIG. 7, in the nonwoven fabrics of Examples 1 and 2, the contact angle at the shoulder part is smaller than that at the top part, the contact angle at the top part is larger after passing liquid than before passing liquid, and the contact angle at the shoulder part is smaller than that at the top part. was smaller after infusion than before infusion.
On the other hand, as shown in FIG. 8, in the nonwoven fabrics of Comparative Examples 1 and 2, the contact angle at the shoulder portion is smaller than that at the top portion, but there is almost no change in the contact angle before and after liquid passage in both the top portion and the shoulder portion.
In this way, the nonwoven fabrics of Examples 1 and 2 become more hydrophobic in the top part and more hydrophilic in the shoulder part by passing liquid, and when the nonwoven fabric is used as a top sheet of an absorbent article, it can be used for a long time. It was confirmed that even in the use of , it was possible to obtain a surface sheet with little liquid return while maintaining good liquid permeability. Furthermore, as shown in FIG. 7, it was confirmed that the nonwoven fabric of Example 1 had a larger overall contact angle and had a higher liquid return suppressing effect than the nonwoven fabric of Example 2.

1...Disposable diaper (absorbent article)
2... Top sheet 3... Back sheet 4... Absorber 21... Upper layer (nonwoven fabric layer)
23...Convex part 26...Top part 27...Shoulder part

Claims (7)

An absorbent article comprising a top sheet placed on the wearer's skin side and an absorbent body placed on the non-skin side of the top sheet,
an intermediate sheet made of a hydrophilic nonwoven fabric arranged on the non-skin side of the top sheet;
The top sheet includes a nonwoven fabric layer having a structure in which a plurality of convex portions protruding toward the wearer's skin are spaced apart from each other, and
The nonwoven fabric layer contains a hydrophilic skin care agent and a hydrophobic skin care agent,
The nonwoven fabric layer has a skin side and a non-skin side opposite to the skin side,
The convex portion has a shoulder portion and a top portion having a lower fiber density than the shoulder portion, and the top portion has a larger contact angle with physiological saline than the shoulder portion, and the contact angle at the top portion before and after passing the liquid. is larger after passing the liquid than before passing the liquid, and the contact angle at the shoulder portion before and after passing the liquid is smaller after passing the liquid than before passing the liquid,
The presence density of the hydrophilic skin care agent is greater in the shoulder portion than in the top portion,
The presence density of the hydrophobic skin care agent is greater on the skin side than on the non-skin side,
The intermediate sheet has a first surface located on the skin side and a second surface opposite to the first surface,
The fiber density of the intermediate sheet is lower on the first surface side than on the second surface side,
The coating area ratio of the first adhesive arranged on the first surface of the intermediate sheet is higher than the coating area ratio of the second adhesive arranged on the second surface of the intermediate sheet. small,
A plurality of the second adhesives are disposed intermittently on the second surface, and the second adhesive overlaps at least a portion of the shoulder portion of the convex portion in a plan view.
Absorbent articles. The absorbent article according to claim 1, wherein the contact angle is smaller on the non-skin side than on the skin side. The absorbent article according to claim 1 or 2, wherein the topsheet includes an upper layer made of the nonwoven fabric layer and a lower layer made of a nonwoven fabric overlaid on the upper layer. The upper layer and the lower layer contain a skin care agent,
The absorbent article according to claim 3, wherein the density of the skin care agent in the upper layer is higher than that in the lower layer. The absorbent article according to claim 3 or 4, wherein the contact angle of the shoulder portion is larger than the contact angle of the lower layer and smaller than the contact angle of the top portion. The absorbent article according to any one of claims 1 to 5, wherein the top sheet has openings between the plurality of convex portions. An absorbent article comprising a top sheet placed on the wearer's skin side and an absorbent body placed on the non-skin side of the top sheet,
an intermediate sheet made of a hydrophilic nonwoven fabric arranged on the non-skin side of the top sheet;
The top sheet includes a nonwoven fabric layer having a structure in which a plurality of convex portions protruding toward the wearer's skin are spaced apart from each other, and
The nonwoven fabric layer contains a hydrophilic skin care agent,
The convex portion has a top portion and a shoulder portion, and the top portion has a larger contact angle with physiological saline than the shoulder portion, and the contact angle at the top portion before and after passing the liquid is greater than that before passing the liquid. The contact angle at the shoulder portion before and after passing the liquid is smaller after passing the liquid than before passing the liquid,
The intermediate sheet has a first surface located on the skin side and a second surface opposite to the first surface,
The coating area ratio of the first adhesive arranged on the first surface of the intermediate sheet is higher than the coating area ratio of the second adhesive arranged on the second surface of the intermediate sheet. small,
A plurality of the second adhesives are disposed intermittently on the second surface, and the second adhesive overlaps at least a portion of the shoulder portion of the convex portion in a plan view. .

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